A novel mutation Thr162Arg of the melanocortin 4 receptor gene in a Spanish children and adolescent population.

PubMed

Ochoa, M C; Azcona, C; Biebermann, H; Brumm, H; Razquin, C; Wermter, A-K; Martínez, J A; Hebebrand, J; Hinney, A; Moreno-Aliaga, M J; Marti, A; Patiño, A; Chueca, M; Oyarzabal, M; Pelach, R

2007-05-01

The melanocortin 4 receptor gene (MC4R) is involved in body weight regulation. While many studies associated MC4R mutations with childhood obesity, information on MC4R mutations in Spanish children and adolescents is lacking. Our objective was to screen a population of children and adolescents from the north of Spain (Navarra) for MC4R mutations and to study the phenotypes of carriers and their families. In addition, functional assays were performed for a novel MC4R mutation. The study was composed of 451 Spanish children and adolescents (49% boys), aged 5-18 year. According to the International Obesity Task Force (IOTF) criteria, the groups included 160 obese, 132 overweight and 159 normal-weight control subjects. One novel (Thr162Arg) and three known nonsynonymous mutations in the MC4R gene (Ser30Phe, Thr150Ile, Ala244Glu) were detected heterozygously. The MC4R mutations were found in three male (one obese and two overweight) and two female subjects (one obese and one overweight). The novel mutation did not appear to lead to an impaired receptor function. An unequivocal relationship of MC4R mutations with obesity in pedigrees together with an impaired function of the encoded receptor could not be established for any of the mutations. The presence of heterozygous MC4R mutations in obese and overweight subjects indicates that these mutations may be a susceptibility factor for obesity development, but lifestyle factors, such as exercise or sedentary activities, may modify their effect.

Functions of Fibroblast Growth Factor Receptors in cancer defined by novel translocations and mutations.

PubMed

Gallo, Leandro H; Nelson, Katelyn N; Meyer, April N; Donoghue, Daniel J

2015-08-01

The four receptor tyrosine kinases (RTKs) within the family of Fibroblast Growth Factor Receptors (FGFRs) are critical for normal development but also play an enormous role in oncogenesis. Mutations and/or abnormal expression often lead to constitutive dimerization and kinase activation of FGFRs, and represent the primary mechanism for aberrant signaling. Sequencing of human tumors has revealed a plethora of somatic mutations in FGFRs that are frequently identical to germline mutations in developmental syndromes, and has also identified novel FGFR fusion proteins arising from chromosomal rearrangements that contribute to malignancy. This review details approximately 200 specific point mutations in FGFRs and 40 different fusion proteins created by translocations involving FGFRs that have been identified in human cancer. This review discusses the effects of these genetic alterations on downstream signaling cascades, and the challenge of drug resistance in cancer treatment with antagonists of FGFRs. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

The cytoplasmic end of transmembrane domain 3 regulates the activity of the Saccharomyces cerevisiae G-protein-coupled alpha-factor receptor.

PubMed Central

Parrish, William; Eilers, Markus; Ying, Weiwen; Konopka, James B

2002-01-01

The binding of alpha-factor to its receptor (Ste2p) activates a G-protein-signaling pathway leading to conjugation of MATa cells of the budding yeast S. cerevisiae. We conducted a genetic screen to identify constitutively activating mutations in the N-terminal region of the alpha-factor receptor that includes transmembrane domains 1-5. This approach identified 12 unique constitutively activating mutations, the strongest of which affected polar residues at the cytoplasmic ends of transmembrane domains 2 and 3 (Asn84 and Gln149, respectively) that are conserved in the alpha-factor receptors of divergent yeast species. Targeted mutagenesis, in combination with molecular modeling studies, suggested that Gln149 is oriented toward the core of the transmembrane helix bundle where it may be involved in mediating an interaction with Asn84. These residues appear to play specific roles in maintaining the inactive conformation of the protein since a variety of mutations at either position cause constitutive receptor signaling. Interestingly, the activity of many mammalian G-protein-coupled receptors is also regulated by conserved polar residues (the E/DRY motif) at the cytoplasmic end of transmembrane domain 3. Altogether, the results of this study suggest a conserved role for the cytoplasmic end of transmembrane domain 3 in regulating the activity of divergent G-protein-coupled receptors. PMID:11861550

Absence of mutations in PAX8, NKX2.5, and TSH receptor genes in patients with thyroid dysgenesis.

PubMed

Brust, Ester S; Beltrao, Cristine B; Chammas, Maria C; Watanabe, Tomoco; Sapienza, Marcelo T; Marui, Suemi

2012-04-01

To precisely classify the various forms of TD, and then to screen for mutations in transcription factor genes active in thyroid development. Patients underwent ultrasound, thyroid scan, and serum thyroglobulin measurement to accurately diagnose the form of TD. DNA was extracted from peripheral leukocytes. The PAX8, and NKX2.5 genes were evaluated in all patients, and TSH receptor (TSHR) gene in those with hypoplasia. In 27 nonconsanguineous patients with TD, 13 were diagnosed with ectopia, 11 with hypoplasia, and 3 with athyreosis. No mutations were detected in any of the genes studied. Sporadic cases of TD are likely to be caused by epigenetic factors, rather than mutations in thyroid transcription factors or genes involved in thyroid development.

Frequency of Epidermal Growth Factor Receptor Mutation in Smokers with Lung Cancer Without Pulmonary Emphysema.

PubMed

Takeda, Kenichi; Yamasaki, Akira; Igishi, Tadashi; Kawasaki, Yuji; Ito-Nishii, Shizuka; Izumi, Hiroki; Sakamoto, Tomohiro; Touge, Hirokazu; Kodani, Masahiro; Makino, Haruhiko; Yanai, Masaaki; Tanaka, Natsumi; Matsumoto, Shingo; Araki, Kunio; Nakamura, Hiroshige; Shimizu, Eiji

2017-02-01

Chronic obstructive pulmonary disease is a smoking-related disease, and is categorized into the emphysema and airway dominant phenotypes. We examined the relationship between emphysematous changes and epidermal growth factor receptor (EGFR) mutation status in patients with lung adenocarcinoma. The medical records for 250 patients with lung adenocarcinoma were retrospectively reviewed. All patients were categorized into the emphysema or non-emphysema group. Wild-type EGFR was detected in 136 (54%) and mutant EGFR in 48 (19%). Emphysematous changes were observed in 87 (36%) patients. EGFR mutation was highly frequent in the non-emphysema group (p=0.0014). Multivariate logistic regression analysis showed that emphysema was an independent risk factor for reduced frequency of EGFR mutation (Odds Ratio=3.47, p=0.005). Our data showed a relationship between emphysematous changes and EGFR mutation status. There might be mutually exclusive genetic risk factors for carcinogenesis and development of emphysematous changes. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

The nonreceptor protein tyrosine phosphatase corkscrew functions in multiple receptor tyrosine kinase pathways in Drosophila.

PubMed

Perkins, L A; Johnson, M R; Melnick, M B; Perrimon, N

1996-11-25

Corkscrew (csw) encodes a nonreceptor protein tyrosine phosphatase (PTPase) that has been implicated in signaling from the Torso receptor tyrosine kinase (RTK). csw mutations, unlike tor mutations, are associated with zygotic lethality, indicating that Csw plays additional roles during development. We have conducted a detailed phenotypic analysis of csw mutations to identify these additional functions of Csw. Our results indicate that Csw operates positively downstream of other Drosophila RTKs such as the Drosophila epidermal growth factor receptor (DER), the fibroblast growth factor receptor (Breathless), and likely other RTKs. This model is substantiated by specific dosage interactions between csw and DER. It is proposed that Csw is part of the evolutionarily conserved "signaling cassette" that operates downstream of all RTKs. In support of this hypothesis, we demonstrate that SHP-2, a vertebrate PTPase similar to Csw and previously implicated in RTK signaling, encodes the functional vertebrate homologue of Csw.

Glioma Specific Extracellular Missense Mutations in the First Cysteine Rich Region of Epidermal Growth Factor Receptor (EGFR) Initiate Ligand Independent Activation

PubMed Central

Ymer, Susie I.; Greenall, Sameer A.; Cvrljevic, Anna; Cao, Diana X.; Donoghue, Jacqui F.; Epa, V. Chandana; Scott, Andrew M.; Adams, Timothy E.; Johns, Terrance G.

2011-01-01

The epidermal growth factor receptor (EGFR) is overexpressed or mutated in glioma. Recently, a series of missense mutations in the extracellular domain (ECD) of EGFR were reported in glioma patients. Some of these mutations clustered within a cysteine-rich region of the EGFR targeted by the therapeutic antibody mAb806. This region is only exposed when EGFR activates and appears to locally misfold during activation. We expressed two of these mutations (R324L and E330K) in NR6 mouse fibroblasts, as they do not express any EGFR-related receptors. Both mutants were autophosphorylated in the absence of ligand and enhanced cell survival and anchorage-independent and xenograft growth. The ECD truncation that produces the de2-7EGFR (or EGFRvIII), the most common EGFR mutation in glioma, generates a free cysteine in this same region. Using a technique optimized for detecting disulfide-bonded dimers, we definitively demonstrated that the de2-7EGFR is robustly dimerized and that ablation of the free cysteine prevents dimerization and activation. Modeling of the R324L mutation suggests it may cause transient breaking of disulfide bonds, leading to similar disulfide-bonded dimers as seen for the de2-7EGFR. These ECD mutations confirm that the cysteine-rich region of EGFR around the mAb806 epitope has a significant role in receptor activation. PMID:24212795

Mutations in fibroblast growth-factor receptor 3 in sporadic cases of achondroplasia occur exclusively on the paternally derived chromosome.

PubMed Central

Wilkin, D J; Szabo, J K; Cameron, R; Henderson, S; Bellus, G A; Mack, M L; Kaitila, I; Loughlin, J; Munnich, A; Sykes, B; Bonaventure, J; Francomano, C A

1998-01-01

More than 97% of achondroplasia cases are caused by one of two mutations (G1138A and G1138C) in the fibroblast growth factor receptor 3 (FGFR3) gene, which results in a specific amino acid substitution, G380R. Sporadic cases of achondroplasia have been associated with advanced paternal age, suggesting that these mutations occur preferentially during spermatogenesis. We have determined the parental origin of the achondroplasia mutation in 40 sporadic cases. Three distinct 1-bp polymorphisms were identified in the FGFR3 gene, within close proximity to the achondroplasia mutation site. Ninety-nine families, each with a sporadic case of achondroplasia in a child, were analyzed in this study. In this population, the achondroplasia mutation occurred on the paternal chromosome in all 40 cases in which parental origin was unambiguous. This observation is consistent with the clinical observation of advanced paternal age resulting in new cases of achondroplasia and suggests that factors influencing DNA replication or repair during spermatogenesis, but not during oogenesis, may predispose to the occurrence of the G1138 FGFR3 mutations. PMID:9718331

Epidermal Growth Factor Receptor targeting in non-small cell lung cancer: revisiting different strategies against the same target.

PubMed

Castañón, Eduardo; Martín, Patricia; Rolfo, Christian; Fusco, Juan P; Ceniceros, Lucía; Legaspi, Jairo; Santisteban, Marta; Gil-Bazo, Ignacio

2014-01-01

Epidermal Growth Factor Receptor (EGFR) tyrosine kinase inhibitors (TKIs) have changed the paradigm of treatment in non-small cell lung cancer (NSCLC). The molecular biology study of EGFR has led to clinical trials that select patients more accurately, regarding the presence of EGFR activating mutations. Nonetheless, a lack of response or a temporary condition of the response has been detected in patients on EGFR TKIs. This has urged to study potential resistance mechanisms underneath. The most important ones are the presence of secondary mutations in EGFR, such as T790M, or the overexpression of mesenchymal-epithelial transition factor (MET) that may explain why patients who initially respond to EGFR TKIs, may ultimately become refractory. Several approaches have been taken and new drugs both targeting EGFR resistance-mutation or MET are currently being developed. Here we review and update the EGFR biological pathway as well as the clinical data leading to approval of the EGFR TKIs currently in the market. New compounds under investigation targeting resistance mutations or dually targeting EGFR and other relevant receptors are also reviewed and discussed.

Diseases associated with growth hormone-releasing hormone receptor (GHRHR) mutations.

PubMed

Martari, Marco; Salvatori, Roberto

2009-01-01

The growth hormone (GH)-releasing hormone (GHRH) receptor (GHRHR) belongs to the G protein-coupled receptors family. It is expressed almost exclusively in the anterior pituitary, where it is necessary for somatotroph cells proliferation and for GH synthesis and secretion. Mutations in the human GHRHR gene (GHRHR) can impair ligand binding and signal transduction, and have been estimated to cause about 10% of autosomal recessive familial isolated growth hormone deficiency (IGHD). Mutations reported to date include five splice donor site mutations, two microdeletions, two nonsense mutations, seven missense mutations, and one mutation in the promoter. These mutations have an autosomal recessive mode of inheritance, and heterozygous individuals do not show signs of IGHD, although the presence of an intermediate phenotype has been hypothesized. Conversely, patients with biallelic mutations have low serum insulin-like growth factor-1 and GH levels (with absent or reduced GH response to exogenous stimuli), resulting--if not treated--in proportionate dwarfism. This chapter reviews the biology of the GHRHR, the mutations that affect its gene and their effects in homozygous and heterozygous individuals. Copyright © 2009 Elsevier Inc. All rights reserved.

Inhibiting the Epidermal Growth Factor Receptor | Center for Cancer Research

Cancer.gov

The Epidermal Growth Factor Receptor (EGFR) is a widely distributed cell surface receptor that responds to several extracellular signaling molecules through an intracellular tyrosine kinase, which phosphorylates target enzymes to trigger a downstream molecular cascade. Since the discovery that EGFR mutations and amplifications are critical in a number of cancers, efforts have

Insight on Mutation-Induced Resistance from Molecular Dynamics Simulations of the Native and Mutated CSF-1R and KIT

PubMed Central

Da Silva Figueiredo Celestino Gomes, Priscila; Chauvot De Beauchêne, Isaure; Panel, Nicolas; Lopez, Sophie; De Sepulveda, Paulo; Geraldo Pascutti, Pedro; Solary, Eric; Tchertanov, Luba

2016-01-01

The receptors tyrosine kinases (RTKs) for the colony stimulating factor-1, CSF-1R, and for the stem cell factor, SCFR or KIT, are important mediators of signal transduction. The abnormal function of these receptors, promoted by gain-of-function mutations, leads to their constitutive activation, associated with cancer or other proliferative diseases. A secondary effect of the mutations is the alteration of receptors’ sensitivity to tyrosine kinase inhibitors, compromising effectiveness of these molecules in clinical treatment. In particular, the mutation V560G in KIT increases its sensitivity to Imatinib, while the D816V in KIT, and D802V in CSF-1R, triggers resistance to the drug. We analyzed the Imatinib binding affinity to the native and mutated KIT (mutations V560G, S628N and D816V) and CSF-1R (mutation D802V) by using molecular dynamics simulations and energy calculations of Imatinib•target complexes. Further, we evaluated the sensitivity of the studied KIT receptors to Imatinib by measuring the inhibition of KIT phosphorylation. Our study showed that (i) the binding free energy of Imatinib to the targets is highly correlated with their experimentally measured sensitivity; (ii) the electrostatic interactions are a decisive factor affecting the binding energy; (iii) the most deleterious impact to the Imatinib sensitivity is promoted by D802V (CSF-1R) and D816V (KIT) mutations; (iv) the role of the juxtamembrane region, JMR, in the imatinib binding is accessory. These findings contribute to a better description of the mutation-induced effects alternating the targets sensitivity to Imatinib. PMID:27467080

The relationship between BIM deletion polymorphism and clinical significance of epidermal growth factor receptor-mutated non-small cell lung cancer patients with epidermal growth factor receptor-tyrosine kinase inhibitor therapy: a meta-analysis.

PubMed

Zou, Qian; Zhan, Ping; Lv, Tangfeng; Song, Yong

2015-12-01

BIM deletion polymorphism is a germline that might lead to little or no BH3 expression, which affects epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) related apoptosis. Recent studies show that BIM deletion polymorphism might be a critical factor leading to the resistance of EGFR-TKIs in EGFR mutation-positive non-small cell lung cancer (NSCLC) patients. Thus, a meta-analysis was conducted by combing seven original eligible studies including 778 NSCLC patients to investigate a steady and reliable conclusion. Our study indicated that BIM deletion polymorphism was significantly associated with the poor objective response rate (ORR) of EGFR-TKIs in EGFR-mutated NSCLC patients [odds ratios (OR) =0.55, 95% confidence interval (CI), 0.33-0.92]. And disease control rate (DCR) in EGFR-mutate NSCLC patients treated with EGFR-TKIs was significantly decreased in patients with BIM deletion polymorphism (OR=0.55, 95% CI, 0.27-1.12). Moreover, the progression-free survival (PFS) of patients with BIM deletion polymorphism is shorter. These findings suggested that BIM deletion polymorphism might be a genetic cause of intrinsic resistance to TKI therapy and it could be emerged as an independent predictor to identify patients who would benefit from TKI targeted therapy in EGFR-mutated NSCLC.

Fibroblast Growth Factor Receptor-4 and Prostate Cancer Progression

DTIC Science & Technology

2007-10-01

difference between the two FGFR-4 variants? Achondroplasia (dwarfism) is caused by a similar mutation in FGFR-3 (Gly380 to Arg380). Increased FGFR-3...what is the molecular basis for the difference between the two FGFR-4 variants? Achondroplasia is caused by a similar mutation in FGFR-3 (Gly380 to...lysosomal targeting of activated fibroblast growth factor receptor 3 in achondroplasia . Proc Natl Acad Sci U S A 2004;101(2):609-14. 27. Hyun TS, Rao DS

Chimeras of the native form or achondroplasia mutant (G375C) of human fibroblast growth factor receptor 3 induce ligand-dependent differentiation of PC12 cells.

PubMed Central

Thompson, L M; Raffioni, S; Wasmuth, J J; Bradshaw, R A

1997-01-01

Mutations in the gene for human fibroblast growth factor receptor 3 (hFGFR3) cause a variety of skeletal dysplasias, including the most common genetic form of dwarfism, achondroplasia (ACH). Evidence indicates that these phenotypes are not due to simple haploinsufficiency of FGFR3 but are more likely related to a role in negatively regulating skeletal growth. The effects of one of these mutations on FGFR3 signaling were examined by constructing chimeric receptors composed of the extracellular domain of human platelet-derived growth factor receptor beta (hPDGFR beta) and the transmembrane and intracellular domains of hFGFR3 or of an ACH (G375C) mutant. Following stable transfection in PC12 cells, which lack platelet-derived growth factor (PDGF) receptors, all clonal cell lines, with either type of chimera, showed strong neurite outgrowth in the presence of PDGF but not in its absence. Antiphosphotyrosine immunoblots showed ligand-dependent autophosphorylation, and both receptor types stimulated strong phosphorylation of mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase, an event associated with the differentiative response of these cells. In addition, ligand-dependent phosphorylation of phospholipase Cgamma and Shc was also observed. All of these responses were comparable to those observed from ligand activation, such as by nerve growth factor, of the native PC12 cells used to prepare the stable transfectants. The cells with the chimera bearing the ACH mutation were more rapidly responsive to ligand with less sustained MAPK activation, indicative of a preactivated or primed condition and consistent with the view that these mutations weaken ligand control of FGFR3 function. However, the full effect of the mutation likely depends in part on structural features of the extracellular domain. Although FGFR3 has been suggested to act as a negative regulator of long-bone growth in chrondrocytes, it produces differentiative signals similar to those of FGFR1, to which only positive effects have been ascribed, in PC12 cells. Therefore, its regulatory effects on bone growth likely result from cellular contexts and not the induction of a unique FGFR3 signaling pathway. PMID:9199352

Epidermal growth factor receptor mutation in gastric cancer.

PubMed

Liu, Zhimin; Liu, Lina; Li, Mei; Wang, Zhaohui; Feng, Lu; Zhang, Qiuping; Cheng, Shihua; Lu, Shen

2011-04-01

Epidermal growth factor receptor (EGFR) and Kirsten-RAS (KRAS) mutations have been identified as predictors of response to EGFR tyrosine kinase inhibitors (TKIs) in non-small cell lung cancer. We aimed to screen the mutations of both genes in gastric carcinoma to detect the suitability of EGFR TKIs for patients with gastric carcinoma. We screened EGFR mutation in exons 19-21 and KRAS mutation in exon 2 in 58 gastric adenocarcinomas from China using high resolution melting analysis (HRMA). Positive samples were confirmed by DNA sequencing. Three EGFR missense mutations (5.2%) and 22 single nucleotide polymorphisms (SNP, Q787Q, 37.9%) were identified. To our knowledge, we report for the first time three mutation patterns of EGFR, Y801C, L858R and G863D, in gastric carcinoma. Two samples with EGFR mutation were mucinous adenocarcinoma. These three samples were collected from male patients aged over 75 years old. The frequency of KRAS mutation was 10.3% (6/58). The exclusiveness of EGFR and KRAS mutations was proven for the first time in gastric cancer. Gastric carcinoma of the mucinous adenocarcinoma type collected from older male patients may harbour EGFR mutations. The small subset of gastric adenocarcinoma patients may respond to EGFR TKIs.

Targeting mutant fibroblast growth factor receptors in cancer.

PubMed

Greulich, Heidi; Pollock, Pamela M

2011-05-01

Fibroblast growth factor receptors (FGFRs) play diverse roles in the control of cell proliferation, cell differentiation, angiogenesis and development. Activating the mutations of FGFRs in the germline has long been known to cause a variety of skeletal developmental disorders, but it is only recently that a similar spectrum of somatic FGFR mutations has been associated with human cancers. Many of these somatic mutations are gain-of-function and oncogenic and create dependencies in tumor cell lines harboring such mutations. A combination of knockdown studies and pharmaceutical inhibition in preclinical models has further substantiated genomically altered FGFR as a therapeutic target in cancer, and the oncology community is responding with clinical trials evaluating multikinase inhibitors with anti-FGFR activity and a new generation of specific pan-FGFR inhibitors. Copyright © 2011. Published by Elsevier Ltd.

[Genetic aspects in congenital hypothyrodism].

PubMed

Perone, Denise; Teixeira, Silvânia S; Clara, Sueli A; Santos, Daniela C dos; Nogueira, Célia R

2004-02-01

Congenital hypothyroidism (CH) affects between 1:3,000 and 1:4,000 newborns. Many genes are essential for normal development of the hypothalamus-pituitary-thyroid axis and hormone production, and are associated with CH. About 85% of primary hypothyroidism is called thyroid digenesis and evidence suggests that mutations in transcription factors (TTF2, TTF1, and PAX-8) and TSH receptor gene could be responsible for the disease. Genetic defects of hormone synthesis could be caused by mutations in the following genes: NIS (natrium-iodide symporter), pendrine, thyreoglobulin (TG), peroxidase (TPO). Recently, mutations in the THOX-2 gene have also been related to organification defects. Central hypothyroidism affects about 1:20,000 newborns and has been associated with mutations in pituitary transcriptional factors (POUIF1, PROP1, LHX3, and HESX1). The syndrome of resistance to thyroid hormone is rare, implies a hypothyroidism state for some tissues and is frequently associated with dominant autosomal mutations in the beta-receptor (TRss).

Epidermal growth factor receptor gene mutation as risk factor for recurrence in patients with surgically resected lung adenocarcinoma: a matched-pair analysis.

PubMed

Matsumura, Yuki; Owada, Yuki; Yamaura, Takumi; Muto, Satoshi; Osugi, Jun; Hoshino, Mika; Higuchi, Mitsunori; Ohira, Tetsuya; Suzuki, Hiroyuki; Gotoh, Mitsukazu

2016-08-01

Epidermal growth factor receptor (EGFR) mutation is a robust prognostic factor in patients with lung adenocarcinoma (ADC). However, the role of EGFR mutation status as a recurrence-risk factor remains unknown because the presence of such mutations is associated with other background characteristics. We therefore conducted a matched-pair analysis to compare recurrence-free survival (RFS) in matched cohorts of patients with lung ADC. We enrolled 379 patients who underwent surgical resection for lung ADC between 2005 and 2012. We determined the EGFR mutation status of each tumour. Matching their age, gender, smoking history and pathological stage (pStage), we compared RFS between matched cohorts with and without EGFR mutation (n = 86 each). The median age was 67 years, there were 39 (45%) men, 39 (45%) ex- or current smokers and pStage I: 71 (83%), II: 5 (6%), III: 8 (9%), IV: 2 (2%) in each group. The 3- and 5-year RFS rates in patients with mutant and wild-type EGFR were 85 and 78%, and 74 and 60%, respectively, with significant differences between the groups (P = 0.040). Multivariate analysis identified vascular invasion and lymphatic permeation, but not EGFR mutation status, as independent risk factors for recurrence. EGFR-gene mutation might be a favourable recurrence-risk factor in patients with surgically resected lung ADC, but further studies in larger cohorts are needed to verify this hypothesis. © The Author 2016. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Two signaling molecules share a phosphotyrosine-containing binding site in the platelet-derived growth factor receptor.

PubMed

Nishimura, R; Li, W; Kashishian, A; Mondino, A; Zhou, M; Cooper, J; Schlessinger, J

1993-11-01

Autophosphorylation sites of growth factor receptors with tyrosine kinase activity function as specific binding sites for Src homology 2 (SH2) domains of signaling molecules. This interaction appears to be a crucial step in a mechanism by which receptor tyrosine kinases relay signals to downstream signaling pathways. Nck is a widely expressed protein consisting exclusively of SH2 and SH3 domains, the overexpression of which causes cell transformation. It has been shown that various growth factors stimulate the phosphorylation of Nck and its association with autophosphorylated growth factor receptors. A panel of platelet-derived growth factor (PDGF) receptor mutations at tyrosine residues has been used to identify the Nck binding site. Here we show that mutation at Tyr-751 of the PDGF beta-receptor eliminates Nck binding both in vitro and in living cells. Moreover, the Y751F PDGF receptor mutant failed to mediate PDGF-stimulated phosphorylation of Nck in intact cells. A phosphorylated Tyr-751 is also required for binding of phosphatidylinositol-3 kinase to the PDGF receptor. Hence, the SH2 domains of p85 and Nck share a binding site in the PDGF receptor. Competition experiments with different phosphopeptides derived from the PDGF receptor suggest that binding of Nck and p85 is influenced by different residues around Tyr-751. Thus, a single tyrosine autophosphorylation site is able to link the PDGF receptor to two distinct SH2 domain-containing signaling molecules.

Structural Determinants for Naturally Evolving H5N1 Hemagglutinin to Switch its Receptor Specificity

PubMed Central

Tharakaraman, Kannan; Raman, Rahul; Viswanathan, Karthik; Stebbins, Nathan W.; Jayaraman, Akila; Krishnan, Arvind; Sasisekharan, V.; Sasisekharan, Ram

2013-01-01

SUMMARY Of the factors governing human-to-human transmission of the highly pathogenic avian-adapted H5N1 virus, the most critical is the acquisition of mutations on the viral hemagglutinin (HA) to “quantitatively switch” its binding from avian to human glycan receptors. Herein, we describe a structural framework that outlines a necessary set of H5 HA receptor binding site (RBS) features required for the H5 HA to quantitatively switch its preference to human receptors. We show here that the same RBS HA mutations that lead to aerosol transmission of A/Vietnam/1203/04 and A/Indonesia/5/05 viruses, when introduced in currently circulating H5N1, do not lead to quantitative switch in receptor preference. We demonstrate that HAs from circulating clades require as few as a single base-pair mutation to quantitatively switch their binding to human receptors. The mutations identified by this study can be used to monitor the emergence of strains having human-to-human transmission potential. PMID:23746829

Comparison of the efficacy of icotinib in patients with non-small-cell lung cancer according to the type of epidermal growth factor receptor mutation.

PubMed

Xue, Zhang Xiao; Wen, Wang Xiu; Zhuang, Yu; Hua, Zang Jian; Xia, Yang Ni

2016-09-01

Icotinib hydrochloride is a novel epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) with preclinical and clinical activity in non-small-cell lung cancer (NSCLC). Exon 19 deletion and L858R point mutation are the most commonly encountered EGFR mutations in NSCLC, and they predict improved clinical outcomes following treatment with icotinib. The objective of this study was to evaluate the differential clinical efficacy of icotinib in patients with exon 19 deletion or L858R point mutation of the EGFR gene. A total of 104 patients with advanced NSCLC, who harbored exon 19 deletion or L858R point mutation of EGFR and were treated with icotinib, were enrolled in this study. The tumor response and progression-free survival were evaluated. There were no significant differences between patients with EGFR exon 19 deletion and those with L858R point mutation who received treatment with icotinib.

CSF1R mutations in hereditary diffuse leukoencephalopathy with spheroids are loss of function

NASA Astrophysics Data System (ADS)

Pridans, Clare; Sauter, Kristin A.; Baer, Kristin; Kissel, Holger; Hume, David A.

2013-10-01

Hereditary diffuse leukoencephalopathy with spheroids (HDLS) in humans is a rare autosomal dominant disease characterized by giant neuroaxonal swellings (spheroids) within the CNS white matter. Symptoms are variable and can include personality and behavioural changes. Patients with this disease have mutations in the protein kinase domain of the colony-stimulating factor 1 receptor (CSF1R) which is a tyrosine kinase receptor essential for microglia development. We investigated the effects of these mutations on Csf1r signalling using a factor dependent cell line. Corresponding mutant forms of murine Csf1r were expressed on the cell surface at normal levels, and bound CSF1, but were not able to sustain cell proliferation. Since Csf1r signaling requires receptor dimerization initiated by CSF1 binding, the data suggest a mechanism for phenotypic dominance of the mutant allele in HDLS.

Epidermal growth factor receptor mutation status is strongly associated with smoking status in patients undergoing surgical resection for lung adenocarcinoma.

PubMed

Matsumura, Yuki; Owada, Yuki; Inoue, Takuya; Watanabe, Yuzuru; Yamaura, Takumi; Fukuhara, Mitsuro; Muto, Satoshi; Okabe, Naoyuki; Hasegawa, Takeo; Hoshino, Mika; Osugi, Jun; Higuchi, Mitsunori; Suzuki, Hiroyuki

2017-11-01

The purpose of this analysis was to examine the relationship between epidermal growth factor receptor (EGFR) mutation status and clinicopathological factors in a cohort of patients who underwent surgical resections for lung adenocarcinoma. From the patients who underwent surgical resections for primary lung cancers between 2005 and 2012, 371 consecutive adenocarcinoma patients were enrolled in this study, and their tumours were analysed for EGFR mutations. We examined the clinicopathological factors of all enrolled patients, including age, sex, pathological stage and smoking status and tested for associations with EGFR mutation status. Among the 371 enrolled patients, 195 (52%) patients had EGFR mutations. There were significantly more women, never smokers and tumours of lower grade histology in the EGFR mutation group than in the wild-type group (P < 0.001 each). However, other factors, such as pathological stage and World Health Organization classification, were not significantly associated with mutation status. Multivariable analysis showed that age, smoking history and histological grade were independently associated with EGFR mutations (P = 0.026, P < 0.001 and P < 0.001, respectively), but sex was not. Regarding smoking status, especially, frequency of EGFR mutation decreased, as smoking index increased. On the other hand, sex and smoking cessation (whether the patients were former or current smokers) were not significantly associated with EGFR mutation status. In our cohort of patients who underwent surgical resection for lung adenocarcinoma, EGFR mutation status was strongly associated with smoking status, especially smoking index. © The Author 2017. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Molecular and clinical aspects of GHRH receptor mutations.

PubMed

Corazzini, Valentina; Salvatori, Roberto

2013-01-01

The growth hormone (GH)-releasing hormone (GHRH) receptor (GHRHR) belongs to the G protein-coupled receptor family. It binds GHRH resulting in somatotroph cell proliferation and stimulation of GH secretion. Mutations in the gene encoding for GHRHR (GHRHR, OMIM No. 139191) are being reported with increasing frequency in familial isolated GH deficiency. To date, the reported GHRHR mutations include eight missense, seven splice, three microdeletions, and two non-sense mutations. One promoter mutation has also been reported. Most of these mutations show a recessive mode of inheritance. The phenotype includes reduced but not absent serum GH, with abnormal response to a variety of stimuli, and low serum insulin-like growth factor-1 levels, resulting in proportionate growth failure which becomes evident in the first year of life. These patients respond well to GH replacement therapy. Phenotypical observations coming from some unusually large kindreds with untreated GH deficiency due to homozygous GHRHR mutations have allowed the study of the consequences of lifetime lack of GH. This chapter reviews the structure and the role of the GHRHR together with the clinical aspects associated with its mutations. Copyright © 2013 S. Karger AG, Basel.

Novel growth hormone receptor gene mutation in a patient with Laron syndrome.

PubMed

Arman, Ahmet; Yüksel, Bilgin; Coker, Ajda; Sarioz, Ozlem; Temiz, Fatih; Topaloglu, Ali Kemal

2010-04-01

Growth Hormone (GH) is a 22 kDa protein that has effects on growth and glucose and fat metabolisms. These effects are initiated by binding of growth hormone (GH) to growth hormone receptors (GHR) expressed in target cells. Mutations or deletions in the growth hormone receptor cause an autosomal disorder called Laron-type dwarfism (LS) characterized by high circulating levels of serum GH and low levels of insulin like growth factor-1 (IGF-1). We analyzed the GHR gene for genetic defect in seven patients identified as Laron type dwarfism. We identified two missense mutations (S40L and W104R), and four polymorphisms (S473S, L526I, G168G and exon 3 deletion). We are reporting a mutation (W104R) at exon 5 of GHR gene that is not previously reported, and it is a novel mutation.

ESR1 Mutations Affect Anti-proliferative Responses to Tamoxifen through Enhanced Cross-Talk with IGF Signaling

PubMed Central

Gelsomino, Luca; Gu, Guowei; Rechoum, Yassine; Beyer, Amanda R; Pejerrey, Sasha M; Tsimelzon, Anna; Wang, Tao; Huffman, Kenneth; Ludlow, Andrew; Ando’, Sebastiano; Fuqua, Suzanne AW

2017-01-01

It is now generally accepted that estrogen receptor (ESR1) mutations occur frequently in metastatic breast cancers, however we do not yet know how to best treat these patients. We have modeled the three most frequent hormone binding ESR1 (HBD-ESR1) mutations (Y537N, Y537S, and D538G) using stable lentiviral transduction in human breast cancer cell lines. Effects on growth were examined in response to hormonal and targeted agents, and mutation-specific changes were studied using microarray and western blot analysis. We determined that the HBD-ESR1 mutations alter anti-proliferative effects to tamoxifen (Tam), due to cell-intrinsic changes in activation of the insulin-like growth factor receptor (IGF1R) signaling pathway and levels of PIK3R1/PIK3R3. The selective estrogen receptor degrader, fulvestrant, significantly reduced the anchorage-independent growth of ESR1 mutant-expressing cells, while combination treatments with the mTOR inhibitor everolimus, or an inhibitor blocking IGF1R and the insulin receptor significantly enhanced anti-proliferative responses. Using digital drop (dd) PCR we identified mutations at high frequencies ranging from 12% for Y537N, 5% for Y537S, and 2% for D538G in archived primary breast tumors from women treated with adjuvant mono-tamoxifen therapy. The HBD-ESR1 mutations were not associated with recurrence-free or overall survival in response in this patient cohort, and suggest that knowledge of other cell-intrinsic factors in combination with ESR1 mutation status will be needed determine anti-proliferative responses to Tam. PMID:27178332

Neutrophil elastase and granulocyte colony-stimulating factor receptor mutation analyses and leukemia evolution in severe congenital neutropenia patients belonging to the original Kostmann family in northern Sweden.

PubMed

Carlsson, Göran; Aprikyan, Andrew A G; Ericson, Kim Göransdotter; Stein, Steve; Makaryan, Vahagn; Dale, David C; Nordenskjöld, Magnus; Fadeel, Bengt; Palmblad, Jan; Hentera, Jan-Inge

2006-05-01

Severe congenital neutropenia (SCN) or Kostmann syndrome was originally reported to be an autosomal recessive disease of neutrophil production causing recurrent, life-threatening infections. Mutations in the neutrophil elastase gene (ELA-2) have previously been identified in patients with sporadic or autosomal dominant SCN. We studied 14 individuals (four patients with SCN and ten close relatives) belonging to the original Kostmann family in northern Sweden for mutations in the ELA-2 and the granulocyte colony-stimulating factor (G-CSF) receptor genes. One patient belonging to the original Kostmann family harbored a novel heterozygous ELA-2 mutation (g.2310T-->A;Leu92His) that was not inherited from her parents. The mutation was identified in DNA isolated from both whole blood and skin fibroblasts, suggesting a sporadic de novo mutation. As a young adult this patient sequentially acquired two mutations in the gene for the G-CSF receptor (G-CSFR) and therefore recently received a hematopoietic stem cell transplant, due to the risk of evolution to leukemia. Moreover, another patient developed acute leukemia and was treated with transplantation. No pathogenic ELA-2 or G-CSFR gene mutations were found in this patient or the other two patients, nor in any healthy relative. Our data are the first to document leukemia evolution and G-CSFR gene mutations in the original Kostmann kindred. In addition, our findings indicate that ELA-2 mutations are not the primary cause of SCN in the Swedish Kostmann family.

Visualizing the origins of selfish de novo mutations in individual seminiferous tubules of human testes

PubMed Central

Maher, Geoffrey J.; McGowan, Simon J.; Giannoulatou, Eleni; Verrill, Clare; Goriely, Anne; Wilkie, Andrew O. M.

2016-01-01

De novo point mutations arise predominantly in the male germline and increase in frequency with age, but it has not previously been possible to locate specific, identifiable mutations directly within the seminiferous tubules of human testes. Using microdissection of tubules exhibiting altered expression of the spermatogonial markers MAGEA4, FGFR3, and phospho-AKT, whole genome amplification, and DNA sequencing, we establish an in situ strategy for discovery and analysis of pathogenic de novo mutations. In 14 testes from men aged 39–90 y, we identified 11 distinct gain-of-function mutations in five genes (fibroblast growth factor receptors FGFR2 and FGFR3, tyrosine phosphatase PTPN11, and RAS oncogene homologs HRAS and KRAS) from 16 of 22 tubules analyzed; all mutations have known associations with severe diseases, ranging from congenital or perinatal lethal disorders to somatically acquired cancers. These results support proposed selfish selection of spermatogonial mutations affecting growth factor receptor-RAS signaling, highlight its prevalence in older men, and enable direct visualization of the microscopic anatomy of elongated mutant clones. PMID:26858415

Visualizing the origins of selfish de novo mutations in individual seminiferous tubules of human testes.

PubMed

Maher, Geoffrey J; McGowan, Simon J; Giannoulatou, Eleni; Verrill, Clare; Goriely, Anne; Wilkie, Andrew O M

2016-03-01

De novo point mutations arise predominantly in the male germline and increase in frequency with age, but it has not previously been possible to locate specific, identifiable mutations directly within the seminiferous tubules of human testes. Using microdissection of tubules exhibiting altered expression of the spermatogonial markers MAGEA4, FGFR3, and phospho-AKT, whole genome amplification, and DNA sequencing, we establish an in situ strategy for discovery and analysis of pathogenic de novo mutations. In 14 testes from men aged 39-90 y, we identified 11 distinct gain-of-function mutations in five genes (fibroblast growth factor receptors FGFR2 and FGFR3, tyrosine phosphatase PTPN11, and RAS oncogene homologs HRAS and KRAS) from 16 of 22 tubules analyzed; all mutations have known associations with severe diseases, ranging from congenital or perinatal lethal disorders to somatically acquired cancers. These results support proposed selfish selection of spermatogonial mutations affecting growth factor receptor-RAS signaling, highlight its prevalence in older men, and enable direct visualization of the microscopic anatomy of elongated mutant clones.

PPARγ2Pro12Ala Polymorphism and Human Health

PubMed Central

He, Weimin

2009-01-01

The nuclear hormone receptor peroxisome proliferator activated receptor gamma (PPARγ) is an important transcription factor regulating adipocyte differentiation, lipid and glucose homeostasis, and insulin sensitivity. Numerous genetic mutations of PPARγ have been identified and these mutations positively or negatively regulate insulin sensitivity. Among these, a relatively common polymorphism of PPARγ, Pro12Ala of PPARγ2, the isoform expressed only in adipose tissue has been shown to be associated with lower body mass index, enhanced insulin sensitivity, and resistance to the risk of type 2 diabetes in human subjects carrying this mutation. Subsequent studies in different ethnic populations, however, have revealed conflicting results, suggesting a complex interaction between the PPARγ2 Pro12Ala polymorphism and environmental factors such as the ratio of dietary unsaturated fatty acids to saturated fatty acids and/or between the PPARγ2 Pro12Ala polymorphism and genetic factors such as polymorphic mutations in other genes. In addition, this polymorphic mutation in PPARγ2 is associated with other aspects of human diseases, including cancers, polycystic ovary syndrome, Alzheimer disease and aging. This review will highlight findings from recent studies. PMID:19390629

Phenotypic variation among familial hypercholesterolemics heterozygous for either one of two Afrikaner founder LDL receptor mutations.

PubMed

Kotze, M J; De Villiers, W J; Steyn, K; Kriek, J A; Marais, A D; Langenhoven, E; Herbert, J S; Graadt Van Roggen, J F; Van der Westhuyzen, D R; Coetzee, G A

1993-10-01

Two common founder-related gene mutations that affect the low-density lipoprotein receptor (LDLR) are responsible for approximately 80% of familial hypercholesterolemia (FH) in South African Afrikaners. The FH Afrikaner-1 (FH1) mutation (Asp206-->Glu) in exon 4 results in defective receptors with approximately 20% of normal activity, whereas the FH Afrikaner-2 (FH2) mutation (Val408-->Met) in exon 9 completely abolishes LDLR activity (< 2% normal activity). We analyzed the contribution of these mutations and other factors on the variation of hypercholesterolemia and clinical features in Afrikaner FH heterozygotes. The type of FH mutation, plasma triglyceride levels, and age of patients each contributed significantly to the variation in hypercholesterolemia, whereas smoking status, high-density lipoprotein cholesterol levels, and gender had no influence. Although all FH heterozygotes had frank hypercholesterolemia, patients with the FH1 mutation had significantly lower cholesterol levels than those with the FH2 mutation. FH1 heterozygotes also tended to have milder clinical features. The differences between the two FH groups could not be explained by a difference in the common apolipoprotein E variants. This study demonstrates that mutational heterogeneity in the LDLR gene influences the phenotypic expression of heterozygous FH.

Epidermal growth factor receptor mutations in 510 Finnish non--small-cell lung cancer patients.

PubMed

Mäki-Nevala, Satu; Rönty, Mikko; Morel, Mike; Gomez, Maria; Dawson, Zoe; Sarhadi, Virinder Kaur; Telaranta-Keerie, Aino; Knuuttila, Aija; Knuutila, Sakari

2014-06-01

Among the driver gene mutations in non-small-cell lung cancer, mutations in epidermal growth factor receptor (EGFR) are the most important because of their predictive role in selecting patients eligible for targeted therapy. Our aim was to study EGFR mutations in a Finnish non-small-cell lung cancer cohort of 528 patients. Mutation testing was conducted on DNA extracted from paraffin-embedded, formalin-fixed tumor material using the following real-time polymerase chain reaction-based kits: Therascreen EGFR PCR Kit and cobas EGFR Mutation Test. EGFR mutation frequency was 11.4% and all positive cases were adenocarcinomas, of which a majority had an acinar predominant pattern. Mutations were seen significantly more often in females and never-smokers than in males and smokers. The most frequent mutations were L858R in exon 21 and deletions in exon 19. Overall survival of the patients, not treated with EGFR inhibitor, did not differ between EGFR mutation-positive and EGFR mutation-negative patients. EGFR mutation profile in this Finnish non-small-cell lung cancer cohort resembles in many respect with that of other Western European cohorts, even though the overall frequency of mutations is slightly higher. We show the occurrence of EGFR mutations in patients with occupational asbestos exposure and also in those diagnosed with chronic obstructive pulmonary disease who have not been often investigated before.

Genomic profiling in a homogeneous molecular subtype of non-small cell lung cancer: An effort to explore new drug targets.

PubMed

Veldore, Vidya H; Patil, S; Satheesh, C T; Shashidhara, H P; Tejaswi, R; Prabhudesai, Shilpa A; Krishnamoorthy, N; Hazarika, D; Naik, R; Rao, Raghavendra M; Ajai Kumar, B S

2015-01-01

Patients' who are positive for kinase domain activating mutations in epidermal growth factor receptor (EGFR) gene, constitute 30-40% of non-small cell lung cancer (NSCLC), and are suitable candidates for Tyrosine Kinase Inhibitor based targeted/personalized therapy. In EGFR non-mutated subset, 8-10% that show molecular abnormalities such as EML4-ALK, ROS1-ALK, KIP4-ALK, may also derive the benefit of targeted therapy. However, 40% of NSCLC belong to a grey zone of tumours that are negative for the clinically approved biomarkers for personalized therapy. This pilot study aims to identify and classify molecular subtypes of this group to address the un-met need for new drug targets in this category. Here we screened for known/novel oncogenic driver mutations using a 46 gene Ampliseq Panel V1.0 that includes Ser/Thr/Tyr kinases, transcription factors and tumor suppressors. NSCLC with tumor burden of at least 40% on histopathology were screened for 29 somatic mutations in the EGFR kinase domain by real-time polymerase chain reaction methods. 20 cases which were EGFR non-mutated for TK domain mutations were included in this study. DNA Quality was verified from each of the 20 cases by fluorimeter, pooled and subjected to targeted re-sequencing in the Ion Torrent platform. Torrent Suite software was used for next generation sequencing raw data processing and variant calling. The clinical relevance and pathological role of all the mutations/variants that include SNPs and Indels was assessed using polyphen-2/SIFT/PROVEAN/mutation assessor structure function prediction programs. There were 10 pathogenic mutations in six different oncogenes for which annotation was available in the COSMIC database; C420R mutation in PIK3CA, Q472H mutation in vascular endothelial growth factor receptor 2 (VEGFR2) (KDR), C630W and C634R in RET, K367M mutation in fibroblast growth factor receptor 2 (FGFR2), G12C in KRAS and 4 pathogenic mutations in TP53 in the DNA binding domain (E285K, R213L, R175H, V173G). Results suggest, a potential role for PIK3CA, VEGFR2, RET and FGFR2 as therapeutic targets in EGFR non-mutated NSCLC that requires further clinical validation.

Soy consumption reduces the risk of non-small-cell lung cancers with epidermal growth factor receptor mutations among Japanese.

PubMed

Matsuo, Keitaro; Hiraki, Akio; Ito, Hidemi; Kosaka, Takayuki; Suzuki, Takeshi; Hirose, Kaoru; Wakai, Kenji; Yatabe, Yasushi; Mitsudomi, Tetsuya; Tajima, Kazuo

2008-06-01

Epidermal growth factor receptor (EGFR) mutations play substantial roles in genesis and proliferation of non-small-cell lung cancers (NSCLCs). We recently found that reproductive factors have a substantial impact on risk of development of NSCLCs featuring such EGFR mutations. Therefore, we explored the influence of dietary habits on NSCLC risk with reference to the EGFR mutational status. We conducted a case-control study using 353 patients with NSCLCs (122 EGFR mutated and 231 EGFR wild-type) and 1765 age-sex matched non-cancer control subjects. Dietary exposure was based on a semiquantitative food frequency questionnaire and impact of major food items, like meats, seafoods, vegetables and soybean products was assessed by multivariate logistic regression. Soybean products demonstrated a protective association with EGFR mutated, but not EGFR wild-type NSCLCs, with multivariate-adjusted odds ratios and 95% confidence intervals for the 2nd and 3rd tertile of soybean product consumption of 0.79 (0.50-1.27) and 0.56 (0.34-0.93) relative to those in the lowest tertile (trend P = 0.023). In conclusion, soy consumption may exert a protective association against the development of NSCLCs with EGFR mutations, providing possible insights into mechanisms of their genesis.

Matched-pair analysis of a multi-institutional cohort reveals that epidermal growth factor receptor mutation is not a risk factor for postoperative recurrence of lung adenocarcinoma.

PubMed

Matsumura, Yuki; Suzuki, Hiroyuki; Ohira, Tetsuya; Shiono, Satoshi; Abe, Jiro; Sagawa, Motoyasu; Sakurada, Akira; Katahira, Masato; Machida, Yuichiro; Takahashi, Satomi; Okada, Yoshinori

2017-12-01

It is unclear whether epidermal growth factor receptor (EGFR) mutation status is a risk factor for postoperative recurrence of surgically resected lung adenocarcinoma (ADC). Therefore, we conducted a multi-institutional study employing matched-pair analysis to compare recurrence-free survival (RFS) and overall survival (OS) of patients with lung ADC according to EGFR mutation status. We collected the records of 909 patients who underwent surgical resection for lung ADC between 2005 and 2012 at five participating institutions and were also examined their EGFR mutation status. For each patient with an EGFR mutation, we selected one with the wild-type EGFR sequence and matched them according to institution, age, gender, smoking history, pathological stage (pStage), and adjuvant treatment. We compared RFS and OS of the matched cohort. The patients were allocated into groups (n=181 each) with mutated or wild-type EGFR sequences. Both cohorts had identical characteristics as follows: institution, median age (68 years), men (85, 47%), ever smokers (77, 43%), and pStage (IA, 108, 60%; IB, 48, 27%; II, 14, 8%; III, 11, 6%). The 3- and 5-year RFS rates of patients with mutated or wild-type EGFR sequence were 79%, 68% and 77%, 68%, respectively (p=0.557). The respective OS rates were 92%, 81%, and 89%, 79% (p=0.574). Matched-pair and multi-institutional analysis reveals that an EGFR mutation was not a significant risk factor for recurrence of patients with surgically resected lung adenocarcinoma. Copyright © 2017 Elsevier B.V. All rights reserved.

Activation of tyrosine kinases by mutation of the gatekeeper threonine

PubMed Central

Azam, Mohammad; Seeliger, Markus A; Gray, Nathanael S; Kuriyan, John; Daley, George Q

2008-01-01

Protein kinases targeted by small-molecule inhibitors develop resistance through mutation of the ‘gatekeeper’ threonine residue of the active site. Here we show that the gatekeeper mutation in the cellular forms of c-ABL, c-SRC, platelet-derived growth factor receptor-α and -β, and epidermal growth factor receptor activates the kinase and promotes malignant transformation of BaF3 cells. Structural analysis reveals that a network of hydrophobic interactions—the hydrophobic spine—characteristic of the active kinase conformation is stabilized by the gatekeeper substitution. Substitution of glycine for the residues constituting the spine disrupts the hydrophobic connectivity and inactivates the kinase. Furthermore, a small-molecule inhibitor that maximizes complementarity with the dismantled spine (compound 14) inhibits the gatekeeper mutation of BCR-ABL-T315I. These results demonstrate that mutation of the gatekeeper threonine is a common mechanism of activation for tyrosine kinases and provide structural insights to guide the development of next-generation inhibitors. PMID:18794843

Fibroblast growth factor receptor signaling in hereditary and neoplastic disease: biologic and clinical implications.

PubMed

Helsten, Teresa; Schwaederle, Maria; Kurzrock, Razelle

2015-09-01

Fibroblast growth factors (FGFs) and their receptors (FGFRs) are transmembrane growth factor receptors with wide tissue distribution. FGF/FGFR signaling is involved in neoplastic behavior and also development, differentiation, growth, and survival. FGFR germline mutations (activating) can cause skeletal disorders, primarily dwarfism (generally mutations in FGFR3), and craniofacial malformation syndromes (usually mutations in FGFR1 and FGFR2); intriguingly, some of these activating FGFR mutations are also seen in human cancers. FGF/FGFR aberrations reported in cancers are mainly thought to be gain-of-function changes, and several cancers have high frequencies of FGFR alterations, including breast, bladder, or squamous cell carcinomas (lung and head and neck). FGF ligand aberrations (predominantly gene amplifications) are also frequently seen in cancers, in contrast to hereditary syndromes. There are several pharmacologic agents that have been or are being developed for inhibition of FGFR/FGF signaling. These include both highly selective inhibitors as well as multi-kinase inhibitors. Of note, only four agents (ponatinib, pazopanib, regorafenib, and recently lenvatinib) are FDA-approved for use in cancer, although the approval was not based on their activity against FGFR. Perturbations in the FGFR/FGF signaling are present in both inherited and malignant diseases. The development of potent inhibitors targeting FGF/FGFR may provide new tools against disorders caused by FGF/FGFR alterations.

ESR1 mutations affect anti-proliferative responses to tamoxifen through enhanced cross-talk with IGF signaling.

PubMed

Gelsomino, Luca; Gu, Guowei; Rechoum, Yassine; Beyer, Amanda R; Pejerrey, Sasha M; Tsimelzon, Anna; Wang, Tao; Huffman, Kenneth; Ludlow, Andrew; Andò, Sebastiano; Fuqua, Suzanne A W

2016-06-01

The purpose of this study was to address the role of ESR1 hormone-binding mutations in breast cancer. Soft agar anchorage-independent growth assay, Western blot, ERE reporter transactivation assay, proximity ligation assay (PLA), coimmunoprecipitation assay, silencing assay, digital droplet PCR (ddPCR), Kaplan-Meier analysis, and statistical analysis. It is now generally accepted that estrogen receptor (ESR1) mutations occur frequently in metastatic breast cancers; however, we do not yet know how to best treat these patients. We have modeled the three most frequent hormone-binding ESR1 (HBD-ESR1) mutations (Y537N, Y537S, and D538G) using stable lentiviral transduction in human breast cancer cell lines. Effects on growth were examined in response to hormonal and targeted agents, and mutation-specific changes were studied using microarray and Western blot analysis. We determined that the HBD-ESR1 mutations alter anti-proliferative effects to tamoxifen (Tam), due to cell-intrinsic changes in activation of the insulin-like growth factor receptor (IGF1R) signaling pathway and levels of PIK3R1/PIK3R3. The selective estrogen receptor degrader, fulvestrant, significantly reduced the anchorage-independent growth of ESR1 mutant-expressing cells, while combination treatments with the mTOR inhibitor everolimus, or an inhibitor blocking IGF1R, and the insulin receptor significantly enhanced anti-proliferative responses. Using digital drop (dd) PCR, we identified mutations at high frequencies ranging from 12 % for Y537N, 5 % for Y537S, and 2 % for D538G in archived primary breast tumors from women treated with adjuvant mono-tamoxifen therapy. The HBD-ESR1 mutations were not associated with recurrence-free or overall survival in response in this patient cohort and suggest that knowledge of other cell-intrinsic factors in combination with ESR1 mutation status will be needed determine anti-proliferative responses to Tam.

Ala67Thr mutation in the poliovirus receptor CD155 is a potential risk factor for vaccine and wild-type paralytic poliomyelitis.

PubMed

Kindberg, Elin; Ax, Cecilia; Fiore, Lucia; Svensson, Lennart

2009-05-01

Poliovirus infections can be asymptomatic or cause severe paralysis. Why some individuals develop paralytic poliomyelitis is unknown, but a role for host genetic factors has been suggested. To investigate if a polymorphism, Ala67Thr, in the poliovirus receptor, which has been found to facilitate increased resistance against poliovirus-induced cell lysis and apoptosis, is associated with increased risk of paralytic poliomyelitis, poliovirus receptor genotyping was undertaken among Italian subjects with vaccine-associated (n = 9), or with wild-type paralytic poliomyelitis (n = 6), and control subjects (n = 71), using RFLP-PCR and pyrosequencing. Heterozygous poliovirus receptor Ala67Thr genotype was found in 13.3% of the patients with paresis and in 8.5% of the controls (Odds Ratio = 1.667). The frequency of Ala67Thr among the controls is in agreement with earlier published data. It is concluded that the Ala67Thr mutation in the poliovirus receptor is a possible risk factor for the development of vaccine-associated or paralytic poliomyelitis associated with wild-type virus. Copyright 2009 Wiley-Liss, Inc.

Skin problems and EGFR-tyrosine kinase inhibitor

PubMed Central

Kozuki, Toshiyuki

2016-01-01

Epidermal growth factor receptor inhibition is a good target for the treatment of lung, colon, pancreatic and head and neck cancers. Epidermal growth factor receptor-tyrosine kinase inhibitor was first approved for the treatment of advanced lung cancer in 2002. Epidermal growth factor receptor-tyrosine kinase inhibitor plays an essential role in the treatment of cancer, especially for patients harbouring epidermal growth factor receptor activating mutation. Hence, skin toxicity is the most concerning issue for the epidermal growth factor receptor-tyrosine kinase inhibitor treatment. Skin toxicity is bothersome and sometimes affects the quality of life and treatment compliance. Thus, it is important for physicians to understand the background and how to manage epidermal growth factor receptor-tyrosine kinase inhibitor-associated skin toxicity. Here, the author reviewed the mechanism and upfront preventive and reactive treatments for epidermal growth factor receptor inhibitor-associated skin toxicities. PMID:26826719

Epidermal growth factor receptor mutations in Japanese men with lung adenocarcinomas.

PubMed

Tomita, Masaki; Ayabe, Takanori; Chosa, Eiichi; Kawagoe, Katsuya; Nakamura, Kunihide

2014-01-01

Epidermal growth factor receptor (EGFR) mutations play a vital role in the prognosis of patients with lung adenocarcinoma. Such somatic mutations are more common in women who are non-smokers with adenocarcinoma and are of Asian origin. However, to our knowledge, there are few studies that have focused on men. One hundred and eighty-four consecutive patients (90 men and 94 women) of resected lung adenocarcinoma were studied retrospectively. EGFR mutations were positive in 48.9% and negative (wild type) in 51.1%. Overall mutation was significant in women (66.0% vs. 32.2%) compared with men (p<0.001). For overall patients, EGFR mutation status was associated with gender, pStage, pT status, lepidic dominant histologic subtype, pure or mixed ground-glass nodule type on computed tomography and smoking status. However, in men, EGFR mutation status was only associated with lepidic dominant histologic subtype and not the other variables. Interestingly, the Brinkman index of men with mutant EGFR also did not differ from that for the wild type (680.0±619.3 vs. 813.1±552.1 p=0.1077). The clinical characteristics of men with lung adenocarcinoma related to EGFR mutation are not always similar to that of overall patients. Especially we failed to find the relationship between EGFR mutations and smoking status in men.

Impact of family history of cancer on the incidence of mutation in epidermal growth factor receptor gene in non-small cell lung cancer patients.

PubMed

He, Yayi; Li, Shuai; Ren, Shengxiang; Cai, Weijing; Li, Xuefei; Zhao, Chao; Li, Jiayu; Chen, Xiaoxia; Gao, Guanghui; Li, Wei; Zhou, Fei; Zhou, Caicun

2013-08-01

Epidermal growth factor receptor (EGFR) activating mutation is an important predictive biomarker of EGFR tyrosine kinase inhibitors (TKIs) in non-small cell lung cancer (NSCLC), while family history of cancer also plays an important role in the neoplasia of lung cancer. This study aimed to investigate the association between family history of cancer and EGFR mutation status in NSCLC population. From February 2008 to May 2012, 538 consecutive NSCLC patients with known EGFR mutation status were included into this study. Amplification refractory mutation system (ARMS) method was used to detect EGFR mutation. The associations between EGFR mutation and family history of cancer were evaluated using logistic regression models. EGFR activating mutation was found in 220 patients and 117 patients had family cancer histories among first-degree relatives. EGFR mutation was more frequently detected in adenocarcinoma patients (p < 0.001), never-smoker (p < 0.001) and with family history of cancer (p = 0.031), especially who had family history of lung cancer (p = 0.008). In multivariate analysis, the association of EGFR mutation with family history of cancer also existed (p = 0.027). NSCLC patients with family history of cancer, especially family history of lung cancer, might have a significantly higher incidence of EGFR activating mutation. Crown Copyright © 2013. Published by Elsevier Ireland Ltd. All rights reserved.

The Colony-Stimulating Factor 3 Receptor T640N Mutation Is Oncogenic, Sensitive to JAK Inhibition, and Mimics T618I.

PubMed

Maxson, Julia E; Luty, Samuel B; MacManiman, Jason D; Paik, Jason C; Gotlib, Jason; Greenberg, Peter; Bahamadi, Swaleh; Savage, Samantha L; Abel, Melissa L; Eide, Christopher A; Loriaux, Marc M; Stevens, Emily A; Tyner, Jeffrey W

2016-02-01

Colony-stimulating factor 3 receptor (CSF3R) mutations have been identified in the majority of chronic neutrophilic leukemia (CNL) and a smaller percentage of atypical chronic myeloid leukemia (aCML) cases. Although CSF3R point mutations (e.g., T618I) are emerging as key players in CNL/aCML, the significance of rarer CSF3R mutations is unknown. In this study, we assess the importance of the CSF3R T640N mutation as a marker of CNL/aCML and potential therapeutic target. Sanger sequencing of leukemia samples was performed to identify CSF3R mutations in CNL and aCML. The oncogenicity of the CSF3R T640N mutation relative to the T618I mutation was assessed by cytokine independent growth assays and by mouse bone marrow transplant. Receptor dimerization and O-glycosylation of the mutants was assessed by Western blot, and JAK inhibitor sensitivity was assessed by colony assay. Here, we identify a CSF3R T640N mutation in two patients with CNL/aCML, one of whom was originally diagnosed with MDS and acquired the T640N mutation upon evolution of disease to aCML. The T640N mutation is oncogenic in cellular transformation assays and an in vivo mouse bone marrow transplantation model. It exhibits many similar phenotypic features to T618I, including ligand independence and altered patterns of O-glycosylation--despite the transmembrane location of T640 preventing access by GalNAc transferase enzymes. Cells transformed by the T640N mutation are sensitive to JAK kinase inhibition to a similar degree as cells transformed by CSF3R T618I. Because of its similarities to CSF3R T618I, the T640N mutation likely has diagnostic and therapeutic relevance in CNL/aCML. ©2015 American Association for Cancer Research.

Impact of epidermal growth factor receptor gene expression level on clinical outcomes in epidermal growth factor receptor mutant lung adenocarcinoma patients taking first-line epidermal growth factor receptor-tyrosine kinase inhibitors.

PubMed

Chang, Huang-Chih; Chen, Yu-Mu; Tseng, Chia-Cheng; Huang, Kuo-Tung; Wang, Chin-Chou; Chen, Yung-Che; Lai, Chien-Hao; Fang, Wen-Feng; Kao, Hsu-Ching; Lin, Meng-Chih

2017-03-01

Epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) are first-choice treatments for advanced non-small-cell lung cancer patients harboring EGFR mutations. Although EGFR mutations are strongly predictive of patients' outcomes and their response to treatment with EGFR-TKIs, early failure of first-line therapy with EGFR-TKIs in patients with EGFR mutations is not rare. Besides several clinical factors influencing EGFR-TKI efficacies studied earlier such as the Eastern Cooperative Oncology Group performance status or uncommon mutation, we would like to see whether semi-quantify EGFR mutation gene expression calculated by 2 -ΔΔct was a prognostic factor in EGFR-mutant non-small cell lung cancer patients receiving first-line EGFR-TKIs. This retrospective study reviews 926 lung cancer patients diagnosed from January 2011 to October 2013 at the Kaohsiung Chang Gung Memorial Hospital in Taiwan. Of 224 EGFR-mutant adenocarcinoma patients, 148 patients who had 2 -ΔΔct data were included. The best cutoff values of 2 -ΔΔct for in-frame deletions in exon 19 (19 deletion) and a position 858 substituted from leucine (L) to an arginine (R) in exon 21 (L858R) were determined using receiver operating characteristic curves. Patients were divided into high and low 2 -ΔΔct expression based on the above cutoff level. The best cutoff point of 2 -ΔΔct value of 19 deletion and L858R was 31.1 and 104.7, respectively. In all, 92 (62.1%) patients showed high 2 -ΔΔct expression and 56 patients (37.9%) low 2 -ΔΔct expression. The mean age was 65.6 years. Progression-free survival of 19 deletion mutant patients with low versus high expression level was 17.07 versus 12.04 months (P = 0.004), respectively. Progression-free survival of L858 mutant patients was 13.75 and 7.96 months (P = 0.008), respectively. EGFR-mutant lung adenocarcinoma patients with lower EGFR gene expression had longer progression-free survival duration without interfering overall survival.

Molecular basis for the Kallmann syndrome-linked fibroblast growth factor receptor mutation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thurman, Ryan D.; Kathir, Karuppanan Muthusamy; Rajalingam, Dakshinamurthy

Highlights: Black-Right-Pointing-Pointer The structural basis of the Kallmann syndrome is elucidated. Black-Right-Pointing-Pointer Kallmann syndrome mutation (A168S) induces a subtle conformational change(s). Black-Right-Pointing-Pointer Structural interactions mediated by beta-sheet G are most perturbed. Black-Right-Pointing-Pointer Ligand (FGF)-receptor interaction(s) is completely abolished by Kallmann mutation. Black-Right-Pointing-Pointer Kallmann mutation directly affects the FGF signaling process. -- Abstract: Kallmann syndrome (KS) is a developmental disease that expresses in patients as hypogonadotropic hypogonadism and anosmia. KS is commonly associated with mutations in the extracellular D2 domain of the fibroblast growth factor receptor (FGFR). In this study, for the first time, the molecular basis for the FGFR associatedmore » KS mutation (A168S) is elucidated using a variety of biophysical experiments, including multidimensional NMR spectroscopy. Secondary and tertiary structural analysis using far UV circular dichroism, fluorescence and limited trypsin digestion assays suggest that the KS mutation induces subtle tertiary structure change in the D2 domain of FGFR. Results of isothermal titration calorimetry experiments show the KS mutation causes a 10-fold decrease in heparin binding affinity and also a complete loss in ligand (FGF-1) binding. {sup 1}H-{sup 15}N chemical perturbation data suggest that complete loss in the ligand (FGF) binding affinity is triggered by a subtle conformational change that disrupts crucial structural interactions in both the heparin and the FGF binding sites in the D2 domain of FGFR. The novel findings reported in this study are expected to provide valuable clues toward a complete understanding of the other genetic diseases linked to mutations in the FGFR.« less

Abnormal XPD-induced nuclear receptor transactivation in DNA repair disorders: trichothiodystrophy and xeroderma pigmentosum.

PubMed

Zhou, Xiaolong; Khan, Sikandar G; Tamura, Deborah; Ueda, Takahiro; Boyle, Jennifer; Compe, Emmanuel; Egly, Jean-Marc; DiGiovanna, John J; Kraemer, Kenneth H

2013-08-01

XPD (ERCC2) is a DNA helicase involved in nucleotide excision repair and in transcription as a structural bridge tying the transcription factor IIH (TFIIH) core with the cdk-activating kinase complex, which phosphorylates nuclear receptors. Mutations in XPD are associated with several different phenotypes, including trichothiodystrophy (TTD), with sulfur-deficient brittle hair, bone defects, and developmental abnormalities without skin cancer, xeroderma pigmentosum (XP), with pigmentary abnormalities and increased skin cancer, or XP/TTD with combined features, including skin cancer. We describe the varied clinical features and mutations in nine patients examined at the National Institutes of Health who were compound heterozygotes for XPD mutations but had different clinical phenotypes: four TTD, three XP, and two combined XP/TTD. We studied TFIIH-dependent transactivation by nuclear receptor for vitamin D (VDR) and thyroid in cells from these patients. The vitamin D stimulation ratio of CYP24 and osteopontin was associated with specific pairs of mutations (reduced in 5, elevated in 1) but not correlated with distinct clinical phenotypes. Thyroid receptor stimulation ratio for KLF9 was not significantly different from normal. XPD mutations frequently were associated with abnormal VDR stimulation in compound heterozygote patients with TTD, XP, or XP/TTD.

Clinical and functional characterization of a patient carrying a compound heterozygous pericentrin mutation and a heterozygous IGF1 receptor mutation.

PubMed

Müller, Eva; Dunstheimer, Desiree; Klammt, Jürgen; Friebe, Daniela; Kiess, Wieland; Kratzsch, Jürgen; Kruis, Tassilo; Laue, Sandy; Pfäffle, Roland; Wallborn, Tillmann; Heidemann, Peter H

2012-01-01

Intrauterine and postnatal longitudinal growth is controlled by a strong genetic component that regulates a complex network of endocrine factors integrating them with cellular proliferation, differentiation and apoptotic processes in target tissues, particularly the growth centers of the long bones. Here we report on a patient born small for gestational age (SGA) with severe, proportionate postnatal growth retardation, discreet signs of skeletal dysplasia, microcephaly and moyamoya disease. Initial genetic evaluation revealed a novel heterozygous IGF1R p.Leu1361Arg mutation affecting a highly conserved residue with the insulin-like growth factor type 1 receptor suggestive for a disturbance within the somatotropic axis. However, because the mutation did not co-segregate with the phenotype and functional characterization did not reveal an obvious impairment of the ligand depending major IGF1R signaling capabilities a second-site mutation was assumed. Mutational screening of components of the somatotropic axis, constituents of the IGF signaling system and factors involved in cellular proliferation, which are described or suggested to provoke syndromic dwarfism phenotypes, was performed. Two compound heterozygous PCNT mutations (p.[Arg585X];[Glu1774X]) were identified leading to the specification of the diagnosis to MOPD II. These investigations underline the need for careful assessment of all available information to derive a firm diagnosis from a sequence aberration.

Clinical and Functional Characterization of a Patient Carrying a Compound Heterozygous Pericentrin Mutation and a Heterozygous IGF1 Receptor Mutation

PubMed Central

Klammt, Jürgen; Friebe, Daniela; Kiess, Wieland; Kratzsch, Jürgen; Kruis, Tassilo; Laue, Sandy; Pfäffle, Roland; Wallborn, Tillmann; Heidemann, Peter H.

2012-01-01

Intrauterine and postnatal longitudinal growth is controlled by a strong genetic component that regulates a complex network of endocrine factors integrating them with cellular proliferation, differentiation and apoptotic processes in target tissues, particularly the growth centers of the long bones. Here we report on a patient born small for gestational age (SGA) with severe, proportionate postnatal growth retardation, discreet signs of skeletal dysplasia, microcephaly and moyamoya disease. Initial genetic evaluation revealed a novel heterozygous IGF1R p.Leu1361Arg mutation affecting a highly conserved residue with the insulin-like growth factor type 1 receptor suggestive for a disturbance within the somatotropic axis. However, because the mutation did not co-segregate with the phenotype and functional characterization did not reveal an obvious impairment of the ligand depending major IGF1R signaling capabilities a second-site mutation was assumed. Mutational screening of components of the somatotropic axis, constituents of the IGF signaling system and factors involved in cellular proliferation, which are described or suggested to provoke syndromic dwarfism phenotypes, was performed. Two compound heterozygous PCNT mutations (p.[Arg585X];[Glu1774X]) were identified leading to the specification of the diagnosis to MOPD II. These investigations underline the need for careful assessment of all available information to derive a firm diagnosis from a sequence aberration. PMID:22693602

Structural Basis for Activation of the Receptor Tyrosine Kinase KIT by Stem Cell Factor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yuzawa,S.; Opatowsky, Y.; Zhang, Z.

2007-01-01

Stem Cell Factor (SCF) initiates its multiple cellular responses by binding to the ectodomain of KIT, resulting in tyrosine kinase activation. We describe the crystal structure of the entire ectodomain of KIT before and after SCF stimulation. The structures show that KIT dimerization is driven by SCF binding whose sole role is to bring two KIT molecules together. Receptor dimerization is followed by conformational changes that enable lateral interactions between membrane proximal Ig-like domains D4 and D5 of two KIT molecules. Experiments with cultured cells show that KIT activation is compromised by point mutations in amino acids critical for D4-D4more » interaction. Moreover, a variety of oncogenic mutations are mapped to the D5-D5 interface. Since key hallmarks of KIT structures, ligand-induced receptor dimerization, and the critical residues in the D4-D4 interface, are conserved in other receptors, the mechanism of KIT stimulation unveiled in this report may apply for other receptor activation.« less

Role of tumour necrosis factor (TNF)-α and TNFRSF1A R92Q mutation in the pathogenesis of TNF receptor-associated periodic syndrome and multiple sclerosis

PubMed Central

Caminero, A; Comabella, M; Montalban, X

2011-01-01

It has long been known that tumour necrosis factor (TNF)/TNFRSF1A signalling is involved in the pathophysiology of multiple sclerosis (MS). Different genetic and clinical findings over the last few years have generated renewed interest in this relationship. This paper provides an update on these recent findings. Genome-wide association studies have identified the R92Q mutation in the TNFRSF1A gene as a genetic risk factor for MS (odds ratio 1·6). This allele, which is also common in the general population and in other inflammatory conditions, therefore only implies a modest risk for MS and provides yet another piece of the puzzle that defines the multiple genetic risk factors for this disease. TNFRSF1A mutations have been associated with an autoinflammatory disease known as TNF receptor-associated periodic syndrome (TRAPS). Clinical observations have identified a group of MS patients carrying the R92Q mutation who have additional TRAPS symptoms. Hypothetically, the co-existence of MS and TRAPS or a co-morbidity relationship between the two could be mediated by this mutation. The TNFRSF1A R92Q mutation behaves as a genetic risk factor for MS and other inflammatory diseases, including TRAPS. Nevertheless, this mutation does not appear to be a severity marker of the disease, neither modifying the clinical progression of MS nor its therapeutic response. An alteration in TNF/TNFRS1A signalling may increase proinflammatory signals; the final clinical phenotype may possibly be determined by other genetic or environmental modifying factors that have not yet been identified. PMID:22059991

Multiplex Ultrasensitive Genotyping of Patients with Non-Small Cell Lung Cancer for Epidermal Growth Factor Receptor (EGFR) Mutations by Means of Picodroplet Digital PCR.

PubMed

Watanabe, Masaru; Kawaguchi, Tomoya; Isa, Shun-Ichi; Ando, Masahiko; Tamiya, Akihiro; Kubo, Akihito; Saka, Hideo; Takeo, Sadanori; Adachi, Hirofumi; Tagawa, Tsutomu; Kawashima, Osamu; Yamashita, Motohiro; Kataoka, Kazuhiko; Ichinose, Yukito; Takeuchi, Yukiyasu; Watanabe, Katsuya; Matsumura, Akihide; Koh, Yasuhiro

2017-07-01

Epidermal growth factor receptor (EGFR) mutations have been used as the strongest predictor of effectiveness of treatment with EGFR tyrosine kinase inhibitors (TKIs). Three most common EGFR mutations (L858R, exon 19 deletion, and T790M) are known to be major selection markers for EGFR-TKIs therapy. Here, we developed a multiplex picodroplet digital PCR (ddPCR) assay to detect 3 common EGFR mutations in 1 reaction. Serial-dilution experiments with genomic DNA harboring EGFR mutations revealed linear performance, with analytical sensitivity ~0.01% for each mutation. All 33 EGFR-activating mutations detected in formalin-fixed paraffin-embedded (FFPE) tissue samples by the conventional method were also detected by this multiplex assay. Owing to the higher sensitivity, an additional mutation (T790M; including an ultra-low-level mutation, <0.1%) was detected in the same reaction. Regression analysis of the duplex assay and multiplex assay showed a correlation coefficient (R 2 ) of 0.9986 for L858R, 0.9844 for an exon 19 deletion, and 0.9959 for T790M. Using ddPCR, we designed a multiplex ultrasensitive genotyping platform for 3 common EGFR mutations. Results of this proof-of-principle study on clinical samples indicate clinical utility of multiplex ddPCR for screening for multiple EGFR mutations concurrently with an ultra-rare pretreatment mutation (T790M). Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Epidermal growth factor receptor mutations in lung adenocarcinoma in Malaysian patients.

PubMed

Liam, Chong-Kin; Wahid, Mohamed Ibrahim A; Rajadurai, Pathmanathan; Cheah, Yoke-Kqueen; Ng, Tiffany Shi-Yeen

2013-06-01

Despite available data from other Asian countries, the prevalence of epidermal growth factor receptor (EGFR) mutations among lung adenocarcinoma patients has not been reported in Malaysia. This study sought to determine the frequency of EGFR mutations among multiethnic Malaysian patients diagnosed with lung adenocarcinoma. Demographic and clinical information of patients whose lung adenocarcinoma biopsy specimens were submitted for EGFR mutation testing at Sime Darby Medical Center from 2009 to 2011 were analyzed. EGFR mutations at exons 18, 19, 20, and 21 were detected either through bidirectional sequencing or real-time polymerase chain reaction. Among 812 patients in the study, 49% were female, 63.7% were ethnic Chinese, 29.4% Malay, 4.8% Indian, and 2.1% other ethnic groups. Mutations were present in the tumors of 321 patients (39.5%), with mutations at exons 19 (23.5%) and 21 (14.9%) being the most common. Mutations were significantly more frequent among women than in men (52.5% versus 27.8%, p < 0.001). Although mutations were more common among Chinese (40.8%) compared with Malay (37.2%) or Indian (33.3%) patients, the difference was not statistically significant (p = 0.591). Of 211 patients with smoking history records, never-smokers had a higher mutation rate compared with ever-smokers (54.8% versus 20.7%, p < 0.001). EGFR mutations were present in 39.5% of patients. Mutations were more common in women and never-smokers with no differences in mutation frequency between different ethnicities. Because of the high mutation rates, reflex testing for EGFR mutation should be a routine practice for advanced lung adenocarcinoma patients in Malaysia.

Usefulness of circulating free DNA for monitoring epidermal growth factor receptor mutations in advanced non-small cell lung cancer patients: a case report

PubMed Central

Gonzalez-Cao, Maria; Ramirez, Santiago Viteri; Ariza, Nuria Jordana; Balada, Ariadna; Garzón, Mónica; Teixidó, Cristina; Karachaliou, Niki; Morales-Espinosa, Daniela; Molina-Vila, Miguel Ángel; Rosell, Rafael

2016-01-01

Genomic analysis of circulating tumor DNA (ctDNA) released from cancer cells into the bloodstream has been proposed as a useful method to capture dynamic changes during the course of the disease. In particular, the ability to monitor epidermal growth factor receptor (EGFR) mutation status in cell-free circulating DNA (cfDNA) isolated from advanced non-small cell lung cancer (NSCLC) patients EGFR can help to the correct management of the disease and overcome the challenges associated with tumor heterogeneity and insufficient biopsied material to perform key molecular diagnosis. Here, we report a case of long term monitorization of EGFR mutation status in cfDNA from peripheral blood in an NSCLC patient in, with excellent correlation with clinical evolution. PMID:27826535

Rapamycin prevents the development and progression of mutant epidermal growth factor receptor lung tumors with the acquired resistance mutation T790M.

PubMed

Kawabata, Shigeru; Mercado-Matos, José R; Hollander, M Christine; Donahue, Danielle; Wilson, Willie; Regales, Lucia; Butaney, Mohit; Pao, William; Wong, Kwok-Kin; Jänne, Pasi A; Dennis, Phillip A

2014-06-26

Lung cancer in never-smokers is an important disease often characterized by mutations in epidermal growth factor receptor (EGFR), yet risk reduction measures and effective chemopreventive strategies have not been established. We identify mammalian target of rapamycin (mTOR) as potentially valuable target for EGFR mutant lung cancer. mTOR is activated in human lung cancers with EGFR mutations, and this increases with acquisition of T790M mutation. In a mouse model of EGFR mutant lung cancer, mTOR activation is an early event. As a single agent, the mTOR inhibitor rapamycin prevents tumor development, prolongs overall survival, and improves outcomes after treatment with an irreversible EGFR tyrosine kinase inhibitor (TKI). These studies support clinical testing of mTOR inhibitors in order to prevent the development and progression of EGFR mutant lung cancers. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Skin problems and EGFR-tyrosine kinase inhibitor.

PubMed

Kozuki, Toshiyuki

2016-04-01

Epidermal growth factor receptor inhibition is a good target for the treatment of lung, colon, pancreatic and head and neck cancers. Epidermal growth factor receptor-tyrosine kinase inhibitor was first approved for the treatment of advanced lung cancer in 2002. Epidermal growth factor receptor-tyrosine kinase inhibitor plays an essential role in the treatment of cancer, especially for patients harbouring epidermal growth factor receptor activating mutation. Hence, skin toxicity is the most concerning issue for the epidermal growth factor receptor-tyrosine kinase inhibitor treatment. Skin toxicity is bothersome and sometimes affects the quality of life and treatment compliance. Thus, it is important for physicians to understand the background and how to manage epidermal growth factor receptor-tyrosine kinase inhibitor-associated skin toxicity. Here, the author reviewed the mechanism and upfront preventive and reactive treatments for epidermal growth factor receptor inhibitor-associated skin toxicities. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Syncytial Mutations Do Not Impair the Specificity of Entry and Spread of a Glycoprotein D Receptor-Retargeted Herpes Simplex Virus

PubMed Central

Okubo, Yu; Wakata, Aika; Suzuki, Takuma; Shibata, Tomoko; Ikeda, Hitomi; Yamaguchi, Miki; Cohen, Justus B.; Glorioso, Joseph C.; Tagaya, Mitsuo; Hamada, Hirofumi; Tahara, Hideaki

2016-01-01

ABSTRACT Membrane fusion, which is the key process for both initial cell entry and subsequent lateral spread of herpes simplex virus (HSV), requires the four envelope glycoproteins gB, gD, gH, and gL. Syncytial mutations, predominantly mapped to the gB and gK genes, confer hyperfusogenicity on HSV and cause multinucleated giant cells, termed syncytia. Here we asked whether interaction of gD with a cognate entry receptor remains indispensable for initiating membrane fusion of syncytial strains. To address this question, we took advantage of mutant viruses whose viral entry into cells relies on the uniquely specific interaction of an engineered gD with epidermal growth factor receptor (EGFR). We introduced selected syncytial mutations into gB and/or gK of the EGFR-retargeted HSV and found that these mutations, especially when combined, enabled formation of extensive syncytia by human cancer cell lines that express the target receptor; these syncytia were substantially larger than the plaques formed by the parental retargeted HSV strain. We assessed the EGFR dependence of entry and spread separately by using direct entry and infectious center assays, respectively, and we found that the syncytial mutations did not override the receptor specificity of the retargeted viruses at either stage. We discuss the implications of these results for the development of more effective targeted oncolytic HSV vectors. IMPORTANCE Herpes simplex virus (HSV) is investigated not only as a human pathogen but also as a promising agent for oncolytic virotherapy. We previously showed that both the initial entry and subsequent lateral spread of HSV can be retargeted to cells expressing tumor-associated antigens by single-chain antibodies fused to a receptor-binding-deficient envelope glycoprotein D (gD). Here we introduced syncytial mutations into the gB and/or gK gene of gD-retargeted HSVs to determine whether viral tropism remained dependent on the interaction of gD with the target receptor. Entry and spread profiles of the recombinant viruses indicated that gD retargeting does not abolish the hyperfusogenic activity of syncytial mutations and that these mutations do not eliminate the dependence of HSV entry and spread on a specific gD-receptor interaction. These observations suggest that syncytial mutations may be valuable for increasing the tumor-specific spreading of retargeted oncolytic HSV vectors. PMID:27707922

High resolution melting analysis for epidermal growth factor receptor mutations in formalin-fixed paraffin-embedded tissue and plasma free DNA from non-small cell lung cancer patients.

PubMed

Jing, Chang-Wen; Wang, Zhuo; Cao, Hai-Xia; Ma, Rong; Wu, Jian-Zhong

2014-01-01

The aim of the research was to explore a cost effective, fast, easy to perform, and sensitive method for epidermal growth factor receptor (EGFR) mutation testing. High resolution melting analysis (HRM) was introduced to evaluate the efficacy of the analysis for dectecting EGFR mutations in exons 18 to 21 using formalin-fixed paraffin-embedded (FFPE) tissues and plasma free DNA from 120 patients. The total EGFR mutation rate was 37.5% (45/120) detected by direct sequencing. There were 48 mutations in 120 FFPE tissues assessed by HRM. For plasma free DNA, the EGFR mutation rate was 25.8% (31/120). The sensitivity of HRM assays in FFPE samples was 100% by HRM. There was a low false-positive mutation rate but a high false-negative rate in plasma free DNA detected by HRM. Our results show that HRM analysis has the advantage of small tumor sample need. HRM applied with plasma free DNA showed a high false-negative rate but a low false-positive rate. Further research into appropriate methods and analysis needs to be performed before HRM for plasma free DNA could be accepted as an option in diagnostic or screening settings.

Rare Complex Mutational Profile in an ALK Inhibitor-resistant Non-small Cell Lung Cancer.

PubMed

Azzato, Elizabeth M; Deshpande, Charuhas; Aikawa, Vania; Aggarwal, Charu; Alley, Evan; Jacobs, Benjamin; Morrissette, Jennifer; Daber, Robert

2015-05-01

Testing for somatic alterations, including anaplastic lymphoma receptor tyrosine kinase gene (ALK) rearrangements and epidermal growth factor receptor gene (EGFR) mutations, is standard practice in the diagnostic evaluation and therapeutic management of non-small cell lung cancer (NSCLC), where the results of such tests can predict response to targeted-therapy. ALK rearrangements, EGFR mutations and mutations in the Kirsten rat sarcoma viral oncogene homolog (KRAS) are considered mutually exclusive in NSCLC. Herein we identified a KRAS Q22K mutation and frameshift mutations in the genes encoding serine/threonine kinase 11 (STK11) and ataxia telangiectasia mutated serine/threonine kinase (ATM) by next-generation sequencing in a patient with ALK rearrangement-positive oligo-metastatic NSCLC, whose disease progressed while on two ALK-targeted therapies. Such a complex diagnostic genetic profile has not been reported in ALK fusion-positive NSCLC. This case highlights the utility of comprehensive molecular testing in the diagnosis of NSCLC. Copyright© 2015 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

Epidermal growth factor receptor and anaplastic lymphoma kinase testing and mutation prevalence in patients with advanced non-small cell lung cancer in Switzerland: A comprehensive evaluation of real world practices.

PubMed

Ess, S M; Herrmann, C; Frick, H; Krapf, M; Cerny, T; Jochum, W; Früh, M

2017-11-01

In order to improve outcomes, identification of the epidermal growth factor receptor (EGFR) and anaplastic lymphoma kinase (ALK) genes has become crucial in advanced non-small-cell lung cancer (NSCLC). The aim of the present study is to analyse time trends and frequency of testing, factors affecting testing as well as prevalence of mutations in the Swiss population. We analysed EGFR and ALK testing in a cohort of patients with newly diagnosed metastasised non-squamous NSCLC in the catchment area of the cancer registry Eastern Switzerland in the years 2008-2014. We analysed prevalence of mutations and studied clinicopathological characteristics and survival of tested and non-tested patients and of patients with and without mutations. Among 718 patients identified, 11% (51/447) harboured an EGFR mutation in the exons 18, 19 or 21 and further 12% (31/265) showed a positive test result for ALK rearrangements. In non-smokers the proportions of mutations were 31% and 23% respectively. Testing rates increased over time and reached 79% in 2014. We observed significantly lower testing rates and poorer survival in elderly, patients with limited life expectancy and patients treated at hospitals not involved in clinical research. Outcomes can be further improved in a considerable proportion of patients with advanced non-squamous NSCLC. © 2017 John Wiley & Sons Ltd.

IRS2 mutations linked to invasion in pleomorphic invasive lobular carcinoma

PubMed Central

Zhu, Sha; Ward, B. Marie; Yu, Jun; Matthew-Onabanjo, Asia N.; Janusis, Jenny; Hsieh, Chung-Cheng; Tomaszewicz, Keith; Hutchinson, Lloyd; Zhu, Lihua Julie; Kandil, Dina; Shaw, Leslie M.

2018-01-01

Pleomorphic invasive lobular carcinoma (PILC) is an aggressive variant of invasive lobular breast cancer that is associated with poor clinical outcomes. Limited molecular data are available to explain the mechanistic basis for PILC behavior. To address this issue, targeted sequencing was performed to identify molecular alterations that define PILC. This sequencing analysis identified genes that distinguish PILC from classic ILC and invasive ductal carcinoma by the incidence of their genomic changes. In particular, insulin receptor substrate 2 (IRS2) is recurrently mutated in PILC, and pathway analysis reveals a role for the insulin receptor (IR)/insulin-like growth factor-1 receptor (IGF1R)/IRS2 signaling pathway in PILC. IRS2 mutations identified in PILC enhance invasion, revealing a role for this signaling adaptor in the aggressive nature of PILC. PMID:29669935

Novel NTRK1 mutations cause hereditary sensory and autonomic neuropathy type IV: demonstration of a founder mutation in the Turkish population.

PubMed

Tüysüz, Beyhan; Bayrakli, Fatih; DiLuna, Michael L; Bilguvar, Kaya; Bayri, Yasar; Yalcinkaya, Cengiz; Bursali, Aysegul; Ozdamar, Elif; Korkmaz, Baris; Mason, Christopher E; Ozturk, Ali K; Lifton, Richard P; State, Matthew W; Gunel, Murat

2008-05-01

Hereditary sensory and autonomic neuropathy type IV (HSAN IV), or congenital insensitivity to pain with anhidrosis, is an autosomal recessive disorder characterized by insensitivity to noxious stimuli, anhidrosis from deinnervated sweat glands, and delayed mental and motor development. Mutations in the neurotrophic tyrosine kinase receptor type 1 (NTRK1), a receptor in the neurotrophin signaling pathway phosphorylated in response to nerve growth factor, are associated with this disorder. We identified six families from Northern Central Turkey with HSAN IV. We screened the NTRK1 gene for mutations in these families. Microsatellite and single nucleotide polymorphism (SNP) markers on the Affymetrix 250K chip platform were used to determine the haplotypes for three families harboring the same mutation. Screening for mutations in the NTRK1 gene demonstrated one novel frameshift mutation, two novel nonsense mutations, and three unrelated kindreds with the same splice-site mutation. Genotyping of the three families with the identical splice-site mutation revealed that they share the same haplotype. This report broadens the spectrum of mutations in NTRK1 that cause HSAN IV and demonstrates a founder mutation in the Turkish population.

Epidermal Growth Factor Receptor Mutation Enhances Expression of Cadherin-5 in Lung Cancer Cells.

PubMed

Hung, Ming-Szu; Chen, I-Chuan; Lung, Jr-Hau; Lin, Paul-Yann; Li, Ya-Chin; Tsai, Ying-Huang

2016-01-01

Epidermal growth factor receptor (EGFR) activation has been shown to play a critical role in tumor angiogenesis. In this study, we investigate the correlation between EGFR mutations and cadherin-5 (CDH5), which is an angiogenic factor, in lung cancer cells. Increased expression CDH5 is observed in lung cancer cells with EGFR mutations. Stable lung cancer cell lines expressing mutant (exon 19 deletion E746-A750, and exon 21 missense mutation L858R) and wild type EGFR genes are established. A significantly higher expression of CDH5 is observed in exon 19 deletion stable lung cancer cells and mouse xenografts. Further studies show that expression of CDH5 is decreased after the inhibition of EGFR and downstream Akt pathways in lung cancer cells with EGFR mutation. In addition, mutant EGFR genes potentiates angiogenesis in lung cancer cells, which is inhibited by CDH5 siRNA, and potentiates migration and invasion in lung cancer cells. Our study shows that mutant EGFR genes are associated with overexpression of CDH5 through increased phosphorylation of EGFR and downstream Akt pathways. Our result may provide an insight into the association of mutant EGFR and CDH5 expression in lung cancer and aid further development of target therapy for NSCLC in the future.

Epidermal Growth Factor Receptor Mutation Enhances Expression of Cadherin-5 in Lung Cancer Cells

PubMed Central

Hung, Ming-Szu; Chen, I-Chuan; Lung, Jr-Hau; Lin, Paul-Yann; Li, Ya-Chin; Tsai, Ying-Huang

2016-01-01

Epidermal growth factor receptor (EGFR) activation has been shown to play a critical role in tumor angiogenesis. In this study, we investigate the correlation between EGFR mutations and cadherin-5 (CDH5), which is an angiogenic factor, in lung cancer cells. Increased expression CDH5 is observed in lung cancer cells with EGFR mutations. Stable lung cancer cell lines expressing mutant (exon 19 deletion E746-A750, and exon 21 missense mutation L858R) and wild type EGFR genes are established. A significantly higher expression of CDH5 is observed in exon 19 deletion stable lung cancer cells and mouse xenografts. Further studies show that expression of CDH5 is decreased after the inhibition of EGFR and downstream Akt pathways in lung cancer cells with EGFR mutation. In addition, mutant EGFR genes potentiates angiogenesis in lung cancer cells, which is inhibited by CDH5 siRNA, and potentiates migration and invasion in lung cancer cells. Our study shows that mutant EGFR genes are associated with overexpression of CDH5 through increased phosphorylation of EGFR and downstream Akt pathways. Our result may provide an insight into the association of mutant EGFR and CDH5 expression in lung cancer and aid further development of target therapy for NSCLC in the future. PMID:27362942

A half-century of studies of growth hormone insensitivity/Laron syndrome: A historical perspective.

PubMed

Rosenbloom, Arlan L

2016-06-01

A growth hormone (GH) dependent substance responsible for sulfate uptake by costal cartilage of hypophysectomized rats, labeled sulfation factor, was reported in 1957. In 1962 the radioimmunoassay for GH was described. The clinical picture of severe GH deficiency but with high serum concentrations of GH was reported in 3 siblings in 1966 and followed by a 1968 report of 22 patients belonging to 14 consanguineous oriental Jewish families in Israel. Defective sulfation factor generation was demonstrated in 15 of these individuals and in a 1971 report; FFA response to IV GH and growth response to GH injections suggested competitive saturation of peripheral tissue receptors by an abnormal GH. However, studies published in 1973 demonstrated normal fractionation of their circulating GH, and normal binding of GH from 22 patients to various antisera used for radioimmunoassay. In 1976, the Israeli investigators reported that circulating GH from 7 patients reacted normally in the recently developed radioreceptor assay for GH. In 1984, using hepatic microsome pellets, they demonstrated that the defect was a failure of GH binding to receptors. Characterization of the human GH receptor (GHR) gene, reported in 1989, included the initial description of a genetic defect of the GHR in 2 of 9 Israeli patients. At about the same time began the identification in Ecuador of what was to become the largest population of GH insensitivity in the world, ~100 individuals, and the only substantial population with a common mutation of the GH receptor. Treatment studies with recombinant IGF-I began in 1990. Growth response was modest compared to that of GH treated GH deficient subjects. The spectrum of GH insensitivity has expanded beyond GH receptor deficiency to include postreceptor abnormalities: IGF-I gene mutation (1996); IGF-I receptor mutation (2003); signal transducer and activator of transcription 5b mutation (2003); and mutation of the GH-dependent acid labile subunit (2004). Rare conditions of GH insensitivity caused by GH receptor and postreceptor abnormalities have provided insights into the processes of growth, body composition, and metabolism. Copyright © 2015 Elsevier Ltd. All rights reserved.

Abnormal XPD-induced nuclear receptor transactivation in DNA repair disorders: trichothiodystrophy and xeroderma pigmentosum

PubMed Central

Zhou, Xiaolong; Khan, Sikandar G; Tamura, Deborah; Ueda, Takahiro; Boyle, Jennifer; Compe, Emmanuel; Egly, Jean-Marc; DiGiovanna, John J; Kraemer, Kenneth H

2013-01-01

XPD (ERCC2) is a DNA helicase involved in nucleotide excision repair and in transcription as a structural bridge tying the transcription factor IIH (TFIIH) core with the cdk-activating kinase complex, which phosphorylates nuclear receptors. Mutations in XPD are associated with several different phenotypes, including trichothiodystrophy (TTD), with sulfur-deficient brittle hair, bone defects, and developmental abnormalities without skin cancer, xeroderma pigmentosum (XP), with pigmentary abnormalities and increased skin cancer, or XP/TTD with combined features, including skin cancer. We describe the varied clinical features and mutations in nine patients examined at the National Institutes of Health who were compound heterozygotes for XPD mutations but had different clinical phenotypes: four TTD, three XP, and two combined XP/TTD. We studied TFIIH-dependent transactivation by nuclear receptor for vitamin D (VDR) and thyroid in cells from these patients. The vitamin D stimulation ratio of CYP24 and osteopontin was associated with specific pairs of mutations (reduced in 5, elevated in 1) but not correlated with distinct clinical phenotypes. Thyroid receptor stimulation ratio for KLF9 was not significantly different from normal. XPD mutations frequently were associated with abnormal VDR stimulation in compound heterozygote patients with TTD, XP, or XP/TTD. PMID:23232694

Prevalence of thyrotropin receptor germline mutations and clinical courses in 89 hyperthyroid patients with diffuse goiter and negative anti-thyrotropin receptor antibodies.

PubMed

Nishihara, Eijun; Fukata, Shuji; Hishinuma, Akira; Amino, Nobuyuki; Miyauchi, Akira

2014-05-01

We studied the frequency of thyrotropin (TSH) receptor mutations in hyperthyroid patients with diffuse goiter and negative TSH receptor antibodies (TRAb), and the clinical pictures of the hyperthyroid patients in the presence and absence of mutations. From 2003 through 2012, 89 hyperthyroid patients with diffuse goiter and negative TRAb based on a second- or third-generation assay underwent sequence analysis of the TSH receptor gene from peripheral leukocytes. The outcome of hyperthyroidism in patients with a TSH receptor mutation and their affected family members was compared with that in patients without any mutation after a 1-10-year follow-up. Germline mutations of the TSH receptor occurred in 4 of the 89 patients (4.5%), including 3 definitive constitutively activating mutations (L512Q, E575K, and D617Y). The main difference in the clinical outcome of hyperthyroidism was that no patients with a TSH receptor mutation achieved euthyroidism throughout the follow-up, while 23.5% of patients without any mutation entered remission. The progression from subclinical to overt hyperthyroidism was not significantly different between patients with or without a mutation. Meanwhile, 10.3% of TRAb-negative patients without any TSH receptor mutation developed TRAb-positive Graves' hyperthyroidism during the follow-up. The prevalence of nonautoimmune hyperthyroidism with TSH receptor mutations is lower than that of latent Graves' disease in TRAb-negative patients with hyperthyroidism. However, all affected patients with a TSH receptor mutation showed persistent hyperthyroidism regardless of subclinical or overt hyperthyroidism throughout the follow-up.

Epidermal growth factor receptor mutations in adenocarcinoma in situ and minimally invasive adenocarcinoma detected using mutation-specific monoclonal antibodies.

PubMed

Nakamura, Haruhiko; Koizumi, Hirotaka; Kimura, Hiroyuki; Marushima, Hideki; Saji, Hisashi; Takagi, Masayuki

2016-09-01

Epidermal growth factor receptor (EGFR) mutation rates in adenocarcinoma in situ (AIS) and minimally invasive adenocarcinoma (MIA) were studied using both DNA analysis and mutation-specific immunohistochemistry. The peptide nucleic acid-locked nucleic acid polymerase chain reaction clamp method was used to detect mutations in exons 18, 19, 20, and 21 of the EGFR gene in DNA samples extracted from paraffin-embedded tissue sections. Simultaneously, immunohistochemical analysis with two EGFR mutation-specific monoclonal antibodies was used to identify proteins resulting from an in-frame deletion in exon 19 (E746_A750del) and a point mutation replacing leucine with arginine at codon 858 of exon 21 (L858R). Forty-three tumors (22 AIS and 21 MIA) were examined. The EGFR mutation rate in AIS detected by DNA analysis was 27.3% (L858R, 5/22; exon 19 deletion,1/22), whereas that detected in MIA was 42.9% (L858R,4/21; exon 19 deletion,5/21). Mutations detected by immunohistochemical analysis included 22.7% (L858R, 4/22; exon 19 deletion, 1/22) in AIS and 42.9% (L858R, 4/21; exon 19 deletion, 5/21) in MIA. Although some results were contradictory, concordant results were obtained using both assays in 38 of 43 cases (88.4%). DNA and immunohistochemical analyses revealed similar EGFR mutation rates in both MIA and AIS, suggesting that mutation-specific monoclonal antibodies are useful to confirm DNA assay results. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Osimertinib in the treatment of patients with epidermal growth factor receptor T790M mutation-positive metastatic non-small cell lung cancer: clinical trial evidence and experience.

PubMed

Sullivan, Ivana; Planchard, David

2016-12-01

Patients with advanced epidermal growth factor receptor (EGFR) mutant non-small cell lung cancer (NSCLC) are particularly sensitive to treatment with first- or second-generation EGFR tyrosine kinase inhibitors such as gefitinib, erlotinib and afatinib, which block the cell-signaling pathways that drive the growth of tumor cells. Unfortunately, the majority of patients develop resistance to them after a median duration of response of around 10 months, and in over half of these patients the emergence of the EGFR T790M resistance mutation is detected. Osimertinib is an oral, highly selective, irreversible inhibitor of both EGFR-activating mutations and the T790M-resistance mutation, while sparing the activity of wild-type EGFR This article reviews clinical trial development of osimertinib in patients with NSCLC, presenting efficacy and safety evidence for its value in the EGFR T790M mutation-positive population and in different settings, including patients with metastatic disease. The preclinical background of clinically acquired resistance to osimertinib is presented and the combination tactics being investigated in an attempt to circumvent this are addressed. © The Author(s), 2016.

Osimertinib in the treatment of patients with epidermal growth factor receptor T790M mutation-positive metastatic non-small cell lung cancer: clinical trial evidence and experience

PubMed Central

Sullivan, Ivana; Planchard, David

2016-01-01

Patients with advanced epidermal growth factor receptor (EGFR) mutant non-small cell lung cancer (NSCLC) are particularly sensitive to treatment with first- or second-generation EGFR tyrosine kinase inhibitors such as gefitinib, erlotinib and afatinib, which block the cell-signaling pathways that drive the growth of tumor cells. Unfortunately, the majority of patients develop resistance to them after a median duration of response of around 10 months, and in over half of these patients the emergence of the EGFR T790M resistance mutation is detected. Osimertinib is an oral, highly selective, irreversible inhibitor of both EGFR-activating mutations and the T790M-resistance mutation, while sparing the activity of wild-type EGFR. This article reviews clinical trial development of osimertinib in patients with NSCLC, presenting efficacy and safety evidence for its value in the EGFR T790M mutation-positive population and in different settings, including patients with metastatic disease. The preclinical background of clinically acquired resistance to osimertinib is presented and the combination tactics being investigated in an attempt to circumvent this are addressed. PMID:27784815

Oestrogen receptor status, treatment and breast cancer prognosis in Icelandic BRCA2 mutation carriers.

PubMed

Jonasson, Jon G; Stefansson, Olafur A; Johannsson, Oskar T; Sigurdsson, Helgi; Agnarsson, Bjarni A; Olafsdottir, Gudridur H; Alexiusdottir, Kristin K; Stefansdottir, Hrefna; Munoz Mitev, Rodrigo; Olafsdottir, Katrin; Olafsdottir, Kristrun; Arason, Adalgeir; Stefansdottir, Vigdis; Olafsdottir, Elinborg J; Barkardottir, Rosa B; Eyfjord, Jorunn E; Narod, Steven A; Tryggvadóttir, Laufey

2016-09-27

The impact of an inherited BRCA2 mutation on the prognosis of women with breast cancer has not been well documented. We studied the effects of oestrogen receptor (ER) status, other prognostic factors and treatments on survival in a large cohort of BRCA2 mutation carriers. We identified 285 breast cancer patients with a 999del5 BRCA2 mutation and matched them with 570 non-carrier patients. Clinical information was abstracted from patient charts and pathology records and supplemented by evaluation of tumour grade and ER status using archived tissue specimens. Univariate and multivariate hazard ratios (HR) were estimated for breast cancer-specific survival using Cox regression. The effects of various therapies were studied in patients treated from 1980 to 2012. Among mutation carriers, positive ER status was associated with higher risk of death than negative ER status (HR=1.94; 95% CI=1.22-3.07, P=0.005). The reverse association was seen for non-carriers (HR=0.71; 95% CI: 0.51-0.97; P=0.03). Among BRCA2 carriers, ER-positive status is an adverse prognostic factor. BRCA2 carrier status should be known at the time when treatment decisions are made.

Epidermal Growth Factor Receptor Activation in Glioblastoma through Novel Missense Mutations in the Extracellular Domain

PubMed Central

Lee, Jeffrey C; Vivanco, Igor; Beroukhim, Rameen; Huang, Julie H. Y; Feng, Whei L; DeBiasi, Ralph M; Yoshimoto, Koji; King, Jennifer C; Nghiemphu, Phioanh; Yuza, Yuki; Xu, Qing; Greulich, Heidi; Thomas, Roman K; Paez, J. Guillermo; Peck, Timothy C; Linhart, David J; Glatt, Karen A; Getz, Gad; Onofrio, Robert; Ziaugra, Liuda; Levine, Ross L; Gabriel, Stacey; Kawaguchi, Tomohiro; O'Neill, Keith; Khan, Haumith; Liau, Linda M; Nelson, Stanley F; Rao, P. Nagesh; Mischel, Paul; Pieper, Russell O; Cloughesy, Tim; Leahy, Daniel J; Sellers, William R; Sawyers, Charles L; Meyerson, Matthew; Mellinghoff, Ingo K

2006-01-01

Background Protein tyrosine kinases are important regulators of cellular homeostasis with tightly controlled catalytic activity. Mutations in kinase-encoding genes can relieve the autoinhibitory constraints on kinase activity, can promote malignant transformation, and appear to be a major determinant of response to kinase inhibitor therapy. Missense mutations in the EGFR kinase domain, for example, have recently been identified in patients who showed clinical responses to EGFR kinase inhibitor therapy. Methods and Findings Encouraged by the promising clinical activity of epidermal growth factor receptor (EGFR) kinase inhibitors in treating glioblastoma in humans, we have sequenced the complete EGFR coding sequence in glioma tumor samples and cell lines. We identified novel missense mutations in the extracellular domain of EGFR in 13.6% (18/132) of glioblastomas and 12.5% (1/8) of glioblastoma cell lines. These EGFR mutations were associated with increased EGFR gene dosage and conferred anchorage-independent growth and tumorigenicity to NIH-3T3 cells. Cells transformed by expression of these EGFR mutants were sensitive to small-molecule EGFR kinase inhibitors. Conclusions Our results suggest extracellular missense mutations as a novel mechanism for oncogenic EGFR activation and may help identify patients who can benefit from EGFR kinase inhibitors for treatment of glioblastoma. PMID:17177598

Mutations Preventing Regulated Exon Skipping in MET Cause Osteofibrous Dysplasia

PubMed Central

Gray, Mary J.; Kannu, Peter; Sharma, Swarkar; Neyt, Christine; Zhang, Dongping; Paria, Nandina; Daniel, Philip B.; Whetstone, Heather; Sprenger, Hans-Georg; Hammerschmidt, Philipp; Weng, Angela; Dupuis, Lucie; Jobling, Rebekah; Mendoza-Londono, Roberto; Dray, Michael; Su, Peiqiang; Wilson, Megan J.; Kapur, Raj P.; McCarthy, Edward F.; Alman, Benjamin A.; Howard, Andrew; Somers, Gino R.; Marshall, Christian R.; Manners, Simon; Flanagan, Adrienne M.; Rathjen, Karl E.; Karol, Lori A.; Crawford, Haemish; Markie, David M.; Rios, Jonathan J.; Wise, Carol A.; Robertson, Stephen P.

2015-01-01

The periosteum contributes to bone repair and maintenance of cortical bone mass. In contrast to the understanding of bone development within the epiphyseal growth plate, factors that regulate periosteal osteogenesis have not been studied as intensively. Osteofibrous dysplasia (OFD) is a congenital disorder of osteogenesis and is typically sporadic and characterized by radiolucent lesions affecting the cortical bone immediately under the periosteum of the tibia and fibula. We identified germline mutations in MET, encoding a receptor tyrosine kinase, that segregate with an autosomal-dominant form of OFD in three families and a mutation in a fourth affected subject from a simplex family and with bilateral disease. Mutations identified in all families with dominant inheritance and in the one simplex subject with bilateral disease abolished the splice inclusion of exon 14 in MET transcripts, which resulted in a MET receptor (METΔ14) lacking a cytoplasmic juxtamembrane domain. Splice exclusion of this domain occurs during normal embryonic development, and forced induction of this exon-exclusion event retarded osteoblastic differentiation in vitro and inhibited bone-matrix mineralization. In an additional subject with unilateral OFD, we identified a somatic MET mutation, also affecting exon 14, that substituted a tyrosine residue critical for MET receptor turnover and, as in the case of the METΔ14 mutations, had a stabilizing effect on the mature protein. Taken together, these data show that aberrant MET regulation via the juxtamembrane domain subverts core MET receptor functions that regulate osteogenesis within cortical diaphyseal bone. PMID:26637977

Imaging of Skeletal Disorders Caused by Fibroblast Growth Factor Receptor Gene Mutations.

PubMed

Sargar, Kiran M; Singh, Achint K; Kao, Simon C

2017-10-01

Fibroblast growth factors and fibroblast growth factor receptors (FGFRs) play important roles in human axial and craniofacial skeletal development. FGFR1, FGFR2, and FGFR3 are crucial for both chondrogenesis and osteogenesis. Mutations in the genes encoding FGFRs, types 1-3, are responsible for various skeletal dysplasias and craniosynostosis syndromes. Many of these disorders are relatively common in the pediatric population, and diagnosis is often challenging. These skeletal disorders can be classified based on which FGFR is affected. Skeletal disorders caused by type 1 mutations include Pfeiffer syndrome (PS) and osteoglophonic dysplasia, and disorders caused by type 2 mutations include Crouzon syndrome (CS), Apert syndrome (AS), and PS. Disorders caused by type 3 mutations include achondroplasia, hypochondroplasia, thanatophoric dysplasia (TD), severe achondroplasia with developmental delay and acanthosis nigricans, Crouzonodermoskeletal syndrome, and Muenke syndrome. Most of these mutations are inherited in an autosomal dominant fashion and are gain-of-function-type mutations. Imaging plays a key role in the evaluation of these skeletal disorders. Knowledge of the characteristic imaging and clinical findings can help confirm the correct diagnosis and guide the appropriate molecular genetic tests. Some characteristics and clinical findings include premature fusion of cranial sutures and deviated broad thumbs and toes in PS; premature fusion of cranial sutures and syndactyly of the hands and feet in AS; craniosynostosis, ocular proptosis, and absence of hand and foot abnormalities in CS; rhizomelic limb shortening, caudal narrowing of the lumbar interpediculate distance, small and square iliac wings, and trident hands in achondroplasia; and micromelia, bowing of the femora, and platyspondyly in TD. © RSNA, 2017.

Luminal expression of cubilin is impaired in Imerslund-Gräsbeck syndrome with compound AMN mutations in intron 3 and exon 7

PubMed Central

Namour, Fares; Dobrovoljski, Gabriele; Chery, Celine; Audonnet, Sandra; Feillet, François; Sperl, Wolfgang; Gueant, Jean-Louis

2011-01-01

Juvenile megaloblastic anaemia 1 (OMIM # 261100) is a rare autosomic disorder characterized by selective cobalamin mal-absorption and inconstant proteinuria produced by mutations in either CUBN or AMN genes. Amnionless, the gene product of AMN, is a transmembrane protein that binds tightly to the N-terminal end of cubilin, the gene product of CUBN. Cubilin binds to intrinsic factor-cobalamin complex and is expressed in the distal intestine and the proximal renal tubule. We report a compound AMN heterozygosity with c.742C>T, p.Gln248X and c.208-2A>G mutations in 2 siblings that led to premature termination codon in exon 7 and exon 6, respectively. It produced a dramatic decrease in receptor activity in urine, despite absence of CUBN mutation and normal affinity of the receptor for intrinsic factor binding. Heterozygous carriers for c.742T and c.208-2G had no pathological signs. These results indicate that amnionless is essential for the correct luminal expression of cubilin in humans. PMID:21750092

Do deficiencies in growth hormone and insulin-like growth factor-1 (IGF-1) shorten or prolong longevity?

PubMed

Laron, Zvi

2005-02-01

Present knowledge on the effects of growth hormone (GH) and insulin-like growth factor-I (IGF-I) deficiency on aging and lifespan are controversial. Studying untreated patients with either isolated GH deficiency due to GH gene deletion, patients with multiple pituitary hormone deficiency due to PROP-1 gene mutation and patients with isolated IGF-I deficiency due to deletions or mutations of the GH receptor gene (Laron syndrome); it was found, that these patients despite signs of early aging (wrinkled skin, obesity, insulin resistance and osteopenia) have a long life span reaching ages of 80-90 years. Animal models of genetic GH deficiencies such as Snell mice (Pit-1 gene mutations) the Ames mice (PROP-1 gene mutation) and the Laron mice (GH receptor gene knock-out) have a statistically significant higher longevity compared to normal controls. On the contrary, mice transgenic for GH and acromegalic patients secreting high amounts of GH have premature death. Those data raise the question whether pharmacological GH administration to adults is deleterious, in contrast to policies advocating such therapies.

Utility of bronchial lavage fluids for epithelial growth factor receptor mutation assay in lung cancer patients: Comparison between cell pellets, cell blocks and matching tissue specimens

PubMed Central

Asaka, Shiho; Yoshizawa, Akihiko; Nakata, Rie; Negishi, Tatsuya; Yamamoto, Hiroshi; Shiina, Takayuki; Shigeto, Shohei; Matsuda, Kazuyuki; Kobayashi, Yukihiro; Honda, Takayuki

2018-01-01

The detection of epidermal growth factor receptor (EGFR) mutations is necessary for the selection of suitable patients with non-small cell lung cancer (NSCLC) for treatment with EGFR tyrosine kinase inhibitors. Cytology specimens are known to be suitable for EGFR mutation detection, although tissue specimens should be prioritized; however, there are limited studies that examine the utility of bronchial lavage fluid (BLF) in mutation detection. The purpose of the present study was to investigate the utility of BLF specimens for the detection of EGFR mutations using a conventional quantitative EGFR polymerase chain reaction (PCR) assay. Initially, quantification cycle (Cq) values of cell pellets, cell-free supernatants and cell blocks obtained from three series of 1% EGFR mutation-positive lung cancer cell line samples were compared for mutation detection. In addition, PCR analysis of BLF specimens obtained from 77 consecutive NSCLC patients, detecting EGFR mutations was validated, and these results were compared with those for the corresponding formalin-fixed paraffin-embedded (FFPE) tissue specimens obtained by surgical resection or biopsy of 49 of these patients. The Cq values for mutation detection were significantly lower in the cell pellet group (average, 29.58) compared with the other groups, followed by those in cell-free supernatants (average, 34.15) and in cell blocks (average, 37.12) for all three series (P<0.05). Mutational status was successfully analyzed in 77 BLF specimens, and the results obtained were concordant with those of the 49 matching FFPE tissue specimens. Notably, EGFR mutations were even detected in 10 cytological specimens that contained insufficient tumor cells. EGFR mutation testing with BLF specimens is therefore a useful and reliable method, particularly when sufficient cancer cells are not obtained. PMID:29399190

Divergent epidermal growth factor receptor mutation patterns between smokers and non-smokers with lung adenocarcinoma.

PubMed

Tseng, Jeng-Sen; Wang, Chih-Liang; Yang, Tsung-Ying; Chen, Chih-Yi; Yang, Cheng-Ta; Chen, Kun-Chieh; Hsu, Kuo-Hsuan; Tsai, Chi-Ren; Chang, Gee-Chen

2015-12-01

Smoking status is an important determinant of the prevalence of epidermal growth factor receptor (EGFR) mutations in lung cancer patients. However, it is unclear whether smoking status could also influence the spectrum of EGFR mutations. We enrolled patients with lung adenocarcinoma from three medical centers in Taiwan. EGFR mutations were assessed by Sanger direct sequencing. The objective of this study was to evaluate the influence of smoking status on both the frequency and patterns of EGFR mutations. From 2001 to 2013, a total of 1175 patients with lung adenocarcinoma were enrolled for EGFR mutation analysis. The overall EGFR mutation rate was 59.6%, which was significantly higher in females than males (69.1% vs. 49.8%) and in non-smokers than current/former smokers (73.8% vs. 29.8%) (both P<0.001). Among patients harboring EGFR mutations, smokers expressed L858R mutation less frequently (35.2% vs. 50.2%, P=0.005) and exon 19 deletions more frequently (52.8% vs 38.8%, P=0.008) than non-smokers. Smokers and non-smokers also had divergent exon 19 deletions subtypes (Del E746-A750 82.5% vs. 57.6%, respectively, P<0.001). Among subgroup patients harboring the L858R mutation, smokers were associated with a higher rate of complex mutations than non-smokers (34.2% vs. 8.4%, P<0.001). Our results suggested that smoking status could influence not only the frequency but also the spectrum of EGFR mutations. These findings provide a clue for further investigation of EGFR mutagenesis. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Selective gene amplification to detect the T790M mutation in plasma from patients with advanced non-small cell lung cancer (NSCLC) who have developed epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) resistance.

PubMed

Nishikawa, Shingo; Kimura, Hideharu; Koba, Hayato; Yoneda, Taro; Watanabe, Satoshi; Sakai, Tamami; Hara, Johsuke; Sone, Takashi; Kasahara, Kazuo; Nakao, Shinji

2018-03-01

The epidermal growth factor receptor (EGFR) T790M mutation is associated with resistance to EGFR tyrosine kinase inhibitors (EGFR-TKIs) in non-small cell lung cancer (NSCLC). However, tissues for the genotyping of the EGFR T790M mutation can be difficult to obtain in a clinical setting. The aims of this study were to evaluate a blood-based, non-invasive approach to detecting the EGFR T790M mutation in advanced NSCLC patients using the PointMan™ EGFR DNA enrichment kit, which is a novel method for the selective amplification of specific genotype sequences. Blood samples were collected from NSCLC patients who had activating EGFR mutations and who were resistant to EGFR-TKI treatment. Using cell-free DNA (cfDNA) from plasma, EGFR T790M mutations were amplified using the PointMan™ enrichment kit, and all the reaction products were confirmed using direct sequencing. The concentrations of plasma DNA were then determined using quantitative real-time PCR. Nineteen patients were enrolled, and 12 patients (63.2%) were found to contain EGFR T790M mutations in their cfDNA, as detected by the kit. T790M mutations were detected in tumor tissues in 12 cases, and 11 of these cases (91.7%) also exhibited the T790M mutation in cfDNA samples. The concentrations of cfDNA were similar between patients with the T790M mutation and those without the mutation. The PointMan™ kit provides a useful method for determining the EGFR T790M mutation status in cfDNA.

Spatial intensity distribution analysis quantifies the extent and regulation of homodimerization of the secretin receptor

PubMed Central

Ward, Richard J.; Pediani, John D.; Harikumar, Kaleeckal G.; Miller, Laurence J.

2017-01-01

Previous studies have indicated that the G-protein-coupled secretin receptor is present as a homodimer, organized through symmetrical contacts in transmembrane domain IV, and that receptor dimerization is critical for high-potency signalling by secretin. However, whether all of the receptor exists in the dimeric form or if this is regulated is unclear. We used measures of quantal brightness of the secretin receptor tagged with monomeric enhanced green fluorescent protein (mEGFP) and spatial intensity distribution analysis to assess this. Calibration using cells expressing plasma membrane-anchored forms of mEGFP initially allowed us to demonstrate that the epidermal growth factor receptor is predominantly monomeric in the absence of ligand and while wild-type receptor was rapidly converted into a dimeric form by ligand, a mutated form of this receptor remained monomeric. Equivalent studies showed that, at moderate expression levels, the secretin receptor exists as a mixture of monomeric and dimeric forms, with little evidence of higher-order complexity. However, sodium butyrate-induced up-regulation of the receptor resulted in a shift from monomeric towards oligomeric organization. In contrast, a form of the secretin receptor containing a pair of mutations on the lipid-facing side of transmembrane domain IV was almost entirely monomeric. Down-regulation of the secretin receptor-interacting G-protein Gαs did not alter receptor organization, indicating that dimerization is defined specifically by direct protein–protein interactions between copies of the receptor polypeptide, while short-term treatment with secretin had no effect on organization of the wild-type receptor but increased the dimeric proportion of the mutated receptor variant. PMID:28424368

Oncogenic role of fibroblast growth factor receptor 3 in tumorigenesis of urinary bladder cancer.

PubMed

Pandith, Arshad A; Shah, Zafar A; Siddiqi, Mushtaq A

2013-05-01

Bladder cancer is the second most common genitourinary tumor and constitutes a very heterogeneous disease. Molecular and pathologic studies suggest that low-grade noninvasive and high-grade invasive urothelial cell carcinoma (UCC) arise via distinct pathways. Low-grade noninvasive UCC represent the majority of tumors at presentation. A high proportion of patients with low-grade UCC develop recurrences but usually with no progression to invasive disease. At presentation, a majority of the bladder tumors (70%-80%) are low-grade noninvasive (pTa). Several genetic changes may occur in bladder cancer, but activating mutations in the fibroblast growth factor receptor 3 (FGFR3) genes are the most common and most specific genetic abnormality in bladder cancer. Interestingly, these mutations are associated with bladder tumors of low stage and grade, which makes the FGFR3 mutation the first marker that can be used for diagnosis of noninvasive bladder tumors. Since the first report of FGFR3 involvement in bladder tumors, numerous studies have been conducted to understand its function and thereby confirm the oncogenic role of this receptor particularly in noninvasive groups. Efforts are on to exploit this receptor as a therapeutic target, which holds much promise in the treatment of bladder cancer, particularly low-grade noninvasive tumors. Further studies need to explore the potential use of FGFR3 mutations in bladder cancer diagnosis, prognosis, and in surveillance of patients with bladder cancer. This review focuses on the role of FGFR3 in bladder tumors in the backdrop of various studies published. Copyright © 2013 Elsevier Inc. All rights reserved.

Aberrant Receptor Internalization and Enhanced FRS2-dependent Signaling Contribute to the Transforming Activity of the Fibroblast Growth Factor Receptor 2 IIIb C3 Isoform*

PubMed Central

Cha, Jiyoung Y.; Maddileti, Savitri; Mitin, Natalia; Harden, T. Kendall; Der, Channing J.

2009-01-01

Alternative splice variants of fibroblast growth factor receptor 2 (FGFR2) IIIb, designated C1, C2, and C3, possess progressive reduction in their cytoplasmic carboxyl termini (822, 788, and 769 residues, respectively), with preferential expression of the C2 and C3 isoforms in human cancers. We determined that the progressive deletion of carboxyl-terminal sequences correlated with increasing transforming potency. The highly transforming C3 variant lacks five tyrosine residues present in C1, and we determined that the loss of Tyr-770 alone enhanced FGFR2 IIIb C1 transforming activity. Because Tyr-770 may compose a putative YXXL sorting motif, we hypothesized that loss of Tyr-770 in the 770YXXL motif may cause disruption of FGFR2 IIIb C1 internalization and enhance transforming activity. Surprisingly, we found that mutation of Leu-773 but not Tyr-770 impaired receptor internalization and increased receptor stability and activation. Interestingly, concurrent mutations of Tyr-770 and Leu-773 caused 2-fold higher transforming activity than caused by the Y770F or L773A single mutations, suggesting loss of Tyr and Leu residues of the 770YXXL773 motif enhances FGFR2 IIIb transforming activity by distinct mechanisms. We also determined that loss of Tyr-770 caused persistent activation of FRS2 by enhancing FRS2 binding to FGFR2 IIIb. Furthermore, we found that FRS2 binding to FGFR2 IIIb is required for increased FRS2 tyrosine phosphorylation and enhanced transforming activity by Y770F mutation. Our data support a dual mechanism where deletion of the 770YXXL773 motif promotes FGFR2 IIIb C3 transforming activity by causing aberrant receptor recycling and stability and persistent FRS2-dependent signaling. PMID:19103595

Hereditary diffuse leukoencephalopathy with axonal spheroids (HDLS): update on molecular genetics.

PubMed

Stabile, Carmen; Taglia, Ilaria; Battisti, Carla; Bianchi, Silvia; Federico, Antonio

2016-09-01

Hereditary diffuse leukoencephalopathy with spheroids (HDLS) is a rare autosomal dominant disease characterized by giant neuroaxonal swellings (spheroids) within the cerebral white matter (WM). Symptoms are variable and can include cognitive, mental and motor dysfunctions. Patients carry mutations in the protein kinase domain of the colony-stimulating factor 1 receptor (CSF1R) which is a tyrosine kinase receptor essential for microglia development. To date, more than 50 pathogenic variants have been reported in patients with HDLS, including missense, frameshift and non-sense mutations, but also deletions and splice-site mutations, all located in the intracellular tyrosine kinase domain, encoded by exons 12-22. The aim of this paper is to review the literature data about the molecular genetic pattern of HDLS.

Tumor heterogeneity of fibroblast growth factor receptor 3 (FGFR3) mutations in invasive bladder cancer: implications for perioperative anti-FGFR3 treatment.

PubMed

Pouessel, D; Neuzillet, Y; Mertens, L S; van der Heijden, M S; de Jong, J; Sanders, J; Peters, D; Leroy, K; Manceau, A; Maille, P; Soyeux, P; Moktefi, A; Semprez, F; Vordos, D; de la Taille, A; Hurst, C D; Tomlinson, D C; Harnden, P; Bostrom, P J; Mirtti, T; Horenblas, S; Loriot, Y; Houédé, N; Chevreau, C; Beuzeboc, P; Shariat, S F; Sagalowsky, A I; Ashfaq, R; Burger, M; Jewett, M A S; Zlotta, A R; Broeks, A; Bapat, B; Knowles, M A; Lotan, Y; van der Kwast, T H; Culine, S; Allory, Y; van Rhijn, B W G

2016-07-01

Fibroblast growth factor receptor 3 (FGFR3) is an actionable target in bladder cancer. Preclinical studies show that anti-FGFR3 treatment slows down tumor growth, suggesting that this tyrosine kinase receptor is a candidate for personalized bladder cancer treatment, particularly in patients with mutated FGFR3. We addressed tumor heterogeneity in a large multicenter, multi-laboratory study, as this may have significant impact on therapeutic response. We evaluated possible FGFR3 heterogeneity by the PCR-SNaPshot method in the superficial and deep compartments of tumors obtained by transurethral resection (TUR, n = 61) and in radical cystectomy (RC, n = 614) specimens and corresponding cancer-positive lymph nodes (LN+, n = 201). We found FGFR3 mutations in 13/34 (38%) T1 and 8/27 (30%) ≥T2-TUR samples, with 100% concordance between superficial and deeper parts in T1-TUR samples. Of eight FGFR3 mutant ≥T2-TUR samples, only 4 (50%) displayed the mutation in the deeper part. We found 67/614 (11%) FGFR3 mutations in RC specimens. FGFR3 mutation was associated with pN0 (P < 0.001) at RC. In 10/201 (5%) LN+, an FGFR3 mutation was found, all concordant with the corresponding RC specimen. In the remaining 191 cases, RC and LN+ were both wild type. FGFR3 mutation status seems promising to guide decision-making on adjuvant anti-FGFR3 therapy as it appeared homogeneous in RC and LN+. Based on the results of TUR, the deep part of the tumor needs to be assessed if neoadjuvant anti-FGFR3 treatment is considered. We conclude that studies on the heterogeneity of actionable molecular targets should precede clinical trials with these drugs in the perioperative setting. © The Author 2016. Published by Oxford University Press on behalf of the European Society for Medical Oncology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Targeting the fibroblast growth factor receptors for the treatment of cancer.

PubMed

Lemieux, Steven M; Hadden, M Kyle

2013-06-01

Receptor tyrosine kinases (RTKs) are transmembrane proteins that play a critical role in stimulating signal transduction cascades to influence cell proliferation, growth, and differentiation and they have also been shown to promote angiogenesis when they are up-regulated or mutated. For this reason, their dysfunction has been implicated in the development of human cancer. Over the past decade, much attention has been devoted to developing inhibitors and antibodies against several classes of RTKs, including vascular endothelial growth factor receptors (VEGFRs), epidermal growth factor receptors (EGFRs), and platelet-derived growth factor receptors (PDGFRs). More recently, interest in the fibroblast growth factor receptor (FGFR) class of RTKs as a drug target for the treatment of cancer has emerged. Signaling through FGFRs is critical for normal cellular function and their dysregulation has been linked to various malignancies such as breast and prostate cancer. This review will focus on the current state of both small molecules and antibodies as FGFR inhibitors to provide insight into their development and future potential as anti-cancer agents.

Comparison of Thoracic Radiotherapy Efficacy Between Patients With and Without EGFR-mutated Lung Adenocarcinoma.

PubMed

Li, Ming-Hsien; Tsai, Jo-Ting; Ting, Lai-Lei; Lin, Jang-Chun; Liu, Yu-Chang

2018-01-01

To investigate the association between tumor response to thoracic radiotherapy and epidermal growth factor receptor (EGFR) mutation status in patients with lung adenocarcinoma, we collected 48 patients treated between January 2010 and December 2013. Of the 18 patients with EGFR mutation, 15 (83.3%) had a single mutation, and three (16.7%) had double mutation. Different EGFR mutation subtypes exhibited different responses to radiotherapy. The identified double EGFR mutations were associated with reduction of residual tumor burden (RTB) after radiotherapy. In univariate analysis, EGFR mutations in exon 18, 20, and 21 and double EGFR mutation were significant factors predicting RTB. In multivariate analysis, exon 20 mutation was the only significant factor. Patients with EGFR mutation seemed to have longer mean overall survival (OS) compared to the group with wild-type EGFR (31.1 vs. 26.6 months, p=0.49). The median and mean OS in patients with double EGFR mutation vs. wild-type EGFR were 20.1 vs. 16.9 months and 28.9 vs. 26.6 months, respectively. Further studies with larger sample size are warranted to clarify the association of EGFR mutation status with the lung tumor response after radiotherapy. Copyright© 2018, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Molecular methods for somatic mutation testing in lung adenocarcinoma: EGFR and beyond

PubMed Central

Rogers, Toni-Maree; Fellowes, Andrew; Bell, Anthony; Fox, Stephen

2015-01-01

Somatic mutational profiling in cancer has revolutionized the practice of clinical oncology. The discovery of driver mutations in non-small cell lung cancer (NSCLC) is an example of this. Molecular testing of lung adenocarcinoma is now considered standard of care and part of the diagnostic algorithm. This article provides an overview of the workflow of molecular testing in a clinical diagnostic laboratory discussing in particular novel assays that are currently in use for somatic mutation detection in NSCLC focussing on epidermal growth factor receptor (EGFR) mutations and anaplastic lymphoma kinase (ALK), ROS1 and RET rearrangements. PMID:25870795

Epidermal growth factor receptor mutations in non- small cell lung cancers in a multiethnic malaysian patient population.

PubMed

Liam, Chong-Kin; Leow, Hwong-Ruey; How, Soon-Hin; Pang, Yong-Kek; Chua, Keong-Tiong; Lim, Boon-Khaw; Lai, Nai-Lang; Kuan, Yeh-Chunn; Pailoor, Jayalakshmi; Rajadurai, Pathmanathan

2014-01-01

Mutations in the tyrosine kinase domain of the epidermal growth factor receptor (EGFR) in non- small cell lung cancer (NSCLC) are predictive of response to EGFR-targeted therapy in advanced stages of disease. This study aimed to determine the frequency of EGFR mutations in NSCLCs and to correlate their presence with clinical characteristics in multiethnic Malaysian patients. In this prospective study, EGFR mutations in exons 18, 19, 20 and 21 in formalin-fixed paraffin-embedded biopsy specimens of consecutive NSCLC patients were asessed by real-time polymerase chain reaction. EGFR mutations were detected in NSCLCs from 55 (36.4%) of a total of 151 patients, being significantly more common in females (62.5%) than in males (17.2%) [odds ratio (OR), 8.00; 95% confidence interval (CI), 3.77-16.98; p<0.001] and in never smokers (62.5%) than in ever smokers (12.7%) (OR, 11.50; 95%CI, 5.08-26.03; p<0.001). Mutations were more common in adenocarcinoma (39.4%) compared to non-adenocarcinoma NSCLCs (15.8%) (p=0.072). The mutation rates in patients of different ethnicities were not significantly different (p=0.08). Never smoking status was the only clinical feature that independently predicted the presence of EGFR mutations (adjusted OR, 5.94; 95%CI, 1.94- 18.17; p=0.002). In Malaysian patients with NSCLC, the EGFR mutation rate was similar to that in other Asian populations. EGFR mutations were significantly more common in female patients and in never smokers. Never smoking status was the only independent predictor for the presence of EGFR mutations.

Transforming Growth Factor-B Receptors in Human Breast Cancer.

DTIC Science & Technology

1998-05-01

I., Polyak, K., Iavarone, A., and Massagud, J. Kip/ Cip and Ink4 cdk inhibitors cooperate to induce cell cycle arrest in response to TGF-ß. Genes Dev...specimens. Thirdly, we have developped transient transfection assays to determine how specific TßR mutations affect affect receptor function. Using...Growth Factor-ß (TGFß) is the most potent known inhibitor of cell cycle progression of normal mammary epithelial cells; in addition, it causes cells

The N-terminal region of the dopamine D2 receptor, a rhodopsin-like GPCR, regulates correct integration into the plasma membrane and endocytic routes

PubMed Central

Cho, DI; Min, C; Jung, KS; Cheong, SY; Zheng, M; Cheong, SJ; Oak, MH; Cheong, JH; Lee, BK; Kim, KM

2012-01-01

BACKGROUND AND PURPOSE Functional roles of the N-terminal region of rhodopsin-like GPCR family remain unclear. Using dopamine D2 and D3 receptors as a model system, we probed the roles of the N-terminal region in the signalling, intracellular trafficking of receptor proteins, and explored the critical factors that determine the functionality of the N-terminal region. EXPERIMENTAL APPROACH The N-terminal region of the D2 receptor was gradually shortened or switched with that of the D3 receptor or a non-specific sequence (FLAG), or potential N-terminal glycosylation sites were mutated. Effects of these manipulations on surface expression, internalization, post-endocytic behaviours and signalling were determined. KEY RESULTS Shortening the N-terminal region of the D2 receptor enhanced receptor internalization and impaired surface expression and signalling; ligand binding, desensitization and down-regulation were not affected but their association with a particular microdomain, caveolae, was disrupted. Replacement of critical residues within the N-terminal region with the FLAG epitope failed to restore surface expression but partially restored the altered internalization and signalling. When the N-terminal regions were switched between D2 and D3 receptors, cell surface expression pattern of each receptor was switched. Mutations of potential N-terminal glycosylation sites inhibited surface expression but enhanced internalization of D2 receptors. CONCLUSIONS AND IMPLICATIONS Shortening of N-terminus or mutation of glycosylation sites located within the N-terminus enhanced receptor internalization but impaired the surface expression of D2 receptors. The N-terminal region of the D2 receptor, in a sequence-specific manner, controls the receptor's conformation and integration into the plasma membrane, which determine its subcellular localization, intracellular trafficking and signalling properties. PMID:22117524

Understanding Mechanisms of Resistance in the Epithelial Growth Factor Receptor in Non‐Small Cell Lung Cancer and the Role of Biopsy at Progression

PubMed Central

Villaruz, Liza C.; Ross, Jeffrey

2016-01-01

Abstract Molecular profiling and the discovery of drugs that target specific activating mutations have allowed the personalization of treatment for non‐small cell lung cancer (NSCLC). The epithelial growth factor receptor (EGFR) is frequently over‐expressed and/or aberrantly activated in different cancers, including NSCLC. The most common activating mutations of EGFR in NSCLC fall within the tyrosine kinase‐binding domain. Three oral EGFR tyrosine kinase inhibitors (TKIs) have been approved by the U.S. Food and Drug Administration (FDA) for first‐line use in patients with EGFR mutation‐positive NSCLC (exon 19 deletions or exon 21 [L858R] substitution mutations), as detected by an FDA‐approved test. However, disease progression is common and is often the result of secondary mutations, of which the EGFR T790M mutation is the most prevalent. Few options were available upon progression until the introduction of osimertinib, a kinase inhibitor that targets the T790M mutation, which was recently approved for use in patients with metastatic EGFR T790M mutation‐positive NSCLC, as detected by an FDA‐approved test, who progressed on or after EGFR TKI therapy. With the introduction of osimertinib, outcomes can now be improved in select patients. Therefore, performing a biopsy at progression to determine the underlying molecular cause of the acquired resistance is important for the enabling of individualized options that may provide the greatest opportunity for improved outcomes. This review discusses the latest updates in molecular testing at progression and outlines treatment options for this difficult‐to‐treat population. Implications for Practice. Although the epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs)—gefitinib, erlotinib, and afatinib—have changed the treatment paradigm for non‐small cell lung cancer among those with EGFR mutation positive disease, most patients experience progression after approximately 12 months of treatment. Until recently, options were limited for patients who progressed, but improvements in molecular profiling and the approval of osimertinib, which targets the resistance mutation T790M, afford the opportunity for improved outcomes in many patients with this mutation. This article explains the options available after progression on initial EGFR TKI therapy and the importance of molecular testing at progression in making treatment decisions. PMID:27821794

Insulin-like growth factor II messenger RNA-binding protein-3 is an independent prognostic factor in uterine leiomyosarcoma.

PubMed

Yasutake, Nobuko; Ohishi, Yoshihiro; Taguchi, Kenichi; Hiraki, Yuka; Oya, Masafumi; Oshiro, Yumi; Mine, Mari; Iwasaki, Takeshi; Yamamoto, Hidetaka; Kohashi, Kenichi; Sonoda, Kenzo; Kato, Kiyoko; Oda, Yoshinao

2018-04-01

The aim of this study was to identify the prognostic factors of uterine leiomyosarcoma (ULMS). We reviewed 60 cases of surgically resected ULMSs and investigated conventional clinicopathological factors, together with the expression of insulin-like growth factor II messenger RNA-binding protein-3 (IMP3), hormone receptors and cell cycle regulatory markers by immunohistochemistry. Mediator complex subunit 12 (MED12) mutation analysis was also performed. Univariate analyses revealed that advanced stage (P < 0.0001), older age (P = 0.0244) and IMP3 expression (P = 0.0011) were significant predictors of a poor outcome. Multivariate analysis revealed advanced stage (P < 0.0001) and IMP3 (P = 0.0373) as independent predictors of a poor prognosis. Expressions of cell cycle markers and hormone receptors, and MED12 mutations (12% in ULMSs) were not identified as prognostic markers in this study. IMP3 expression in ULMS could be a marker of a poor prognosis. © 2017 John Wiley & Sons Ltd.

Hypothesis of the cause and development of neoplasms.

PubMed

Hoang, Ba X; Levine, Stephen A; Pham, Phuong; Shaw, David Graeme

2007-02-01

Cancer, in general, is considered a disease of genetic mutation. Many questions are, however, unanswered. How exactly do mutations occur in the cells? How do gene mutations interface with the cell microenvironment and macroenvironment to create cancer phenotypes? Is mutation the cause of cancer or the consequence of special adaptive responses to aging; hormonal imbalance; physical, chemical and biologic stresses and damage? What makes cancer spread in the body and invade other organs causing death to the patient? In this paper, we hypothesize that the cellular hyperexcitability via stimulation of mineral channels (e.g. sodium voltage-gated channels) and ligand excitatory receptors (e.g. glutamate and other neuron and non-neuronal excitatory receptors) could be a significant causative and pathogenic factor of cancer. Managing hyperexcitatory states of the cells through lifestyle, nutritional changes, phytochemical and pharmaceutical medications theoretically could be a prospective direction in cancer prevention and therapy.

Thyroid hyperfunctioning adenomas with and without Gsp/TSH receptor mutations show similar clinical features.

PubMed

Arturi, F; Capula, C; Chiefari, E; Filetti, S; Russo, D

1998-01-01

Activating mutations of Gs alpha protein (gsp) and TSH receptor (TSH-R) identified in autonomously hyperfunctioning thyroid adenomas have been proposed as the primary event responsible for this disease. Since mutations have not been detected in 100% (ranging from less than 10% to 90%) of the patients, we evaluated whether the presence of gsp and TSH-R mutations cause differences in the clinical and biochemical parameters of the affected patients. Fifteen consecutive patients (11 women and 4 men) with autonomously hyperfunctioning thyroid adenomas who underwent thyroidectomy, previously examined for the presence of gsp or TSH-R mutations, were investigated. In all of the patients we examined plasma free T3, free T4, TSH levels and ultrasound volume of the nodules. The patients with mutations in gsp or TSH-R were similar to the patients without mutations for clinical presentation, sex distribution and mean age. Furthermore, basal serum FT3, TSH and tumor volume in the patients with mutations were not significantly different from the group without mutations. Our preliminary data demonstrate that no significant differences are present in the two groups of patients examined, suggesting that factors other than gsp or TSH-R mutations play a role in the clinical presentation of the disease.

PTPRS Regulates Colorectal Cancer RAS Pathway Activity by Inactivating Erk and Preventing Its Nuclear Translocation.

PubMed

Davis, Thomas B; Yang, Mingli; Schell, Michael J; Wang, Heiman; Ma, Le; Pledger, W Jack; Yeatman, Timothy J

2018-06-18

Colorectal cancer (CRC) growth and progression is frequently driven by RAS pathway activation through upstream growth factor receptor activation or through mutational activation of KRAS or BRAF. Here we describe an additional mechanism by which the RAS pathway may be modulated in CRC. PTPRS, a receptor-type protein tyrosine phosphatase, appears to regulate RAS pathway activation through ERK. PTPRS modulates ERK phosphorylation and subsequent translocation to the nucleus. Native mutations in PTPRS, present in ~10% of CRC, may reduce its phosphatase activity while increasing ERK activation and downstream transcriptional signaling.

Inflammatory fibroid polyp of the gallbladder bearing a platelet-derived growth factor receptor alpha mutation.

PubMed

Martini, Maurizio; Santoro, Luisa; Familiari, Pietro; Costamagna, Guido; Ricci, Riccardo

2013-05-01

The inflammatory fibroid polyp (IFP) is a benign lesion occurring in the digestive tract, mostly in the stomach and small bowel, composed of fibrovascular tissue infiltrated by inflammatory cells including eosinophils and mastocytes. Its pathogenesis has been controversial (reactive versus neoplastic). The recent finding of mutations in platelet-derived growth factor receptor α (PDGFRA) in most gastric and small intestinal IFPs supported their neoplastic etiology, moreover helping in their differential diagnosis. In the only gallbladder IFP reported so far, the diagnosis was based on morphologic and immunohistochemical grounds, which in current standards would probably be considered not fully conclusive. Conversely, the gallbladder IFP we report shows typical pathologic features supported by a PDGFRA mutation, similar to its usual gastric and small intestinal counterparts, constituting the first report of an unequivocal IFP at gallbladder level. Thus, IFPs must be considered in the differential diagnosis of gallbladder mesenchymal masses, and genetic analysis of PDGFRA is a helpful tool for this purpose.

EGFR-TKIs resistance via EGFR-independent signaling pathways.

PubMed

Liu, Qian; Yu, Shengnan; Zhao, Weiheng; Qin, Shuang; Chu, Qian; Wu, Kongming

2018-02-19

Tyrosine kinase inhibitors (TKIs)-treatments bring significant benefit for patients harboring epidermal growth factor receptor (EGFR) mutations, especially for those with lung cancer. Unfortunately, the majority of these patients ultimately develop to the acquired resistance after a period of treatment. Two central mechanisms are involved in the resistant process: EGFR secondary mutations and bypass signaling activations. In an EGFR-dependent manner, acquired mutations, such as T790 M, interferes the interaction between TKIs and the kinase domain of EGFR. While in an EGFR-independent manner, dysregulation of other receptor tyrosine kinases (RTKs) or abnormal activation of downstream compounds both have compensatory functions against the inhibition of EGFR through triggering phosphatidylinositol 3-kinase (PI3K)/Akt and mitogen-activated protein kinase (MAPK) signaling axes. Nowadays, many clinical trials aiming to overcome and prevent TKIs resistance in various cancers are ongoing or completed. EGFR-TKIs in accompany with the targeted agents for resistance-related factors afford a promising first-line strategy to further clinical application.

Molecular dynamics simulation analysis of the effect of T790M mutation on epidermal growth factor receptor protein architecture in non-small cell lung carcinoma.

PubMed

Peng, Xiao-Nu; Wang, Jing; Zhang, Wei

2017-08-01

Non-small cell lung cancer etiology and its treatment failure are due to epidermal growth factor receptor (EGFR) kinase domain mutations at amino acid position 790. The mutational change from threonine to methionine at position 790 (T790M) is responsible for tyrosine kinase inhibition failure. Using molecular dynamic simulation, the present study investigated the architectural changes occurring at the atomic scale. The 50-nsec runs using a GROMOS force field for wild-type and mutant EGFR's kinase domains were investigated for contrasting variations using Gromacs inbuilt tools. The adenosine triphosphate binding domain and the active site of EGFR were studied extensively in order to understand the structural changes. All the parameters investigated in the present study revealed considerable changes in the studied structures, and the knowledge gained from this may be used to develop novel kinase inhibitors that will be effective irrespective of the structural alterations in kinase domain.

Screening anti-tumor compounds from Ligusticum wallichii using cell membrane chromatography combined with high-performance liquid chromatography and mass spectrometry.

PubMed

Zhang, Tao; Ding, Yuanyuan; An, Hongli; Feng, Liuxin; Wang, Sicen

2015-07-14

Tyrosine 367 Cysteine-fibroblast growth factor receptor 4 cell membrane chromatography combined with high-performance liquid chromatography and mass spectrometry was developed. Tyrosine 367 Cysteine-HEK293 cells were used as cell membrane stationary phase. Specificity and reproducibility of the cell membrane chromatography was evaluated using 1-tert-butyl-3-{2-[4-(diethylamino)butylamino]-6-(3,5-dimethoxyphenyl)pyrido[2,3-d]pyrimidin-7-yl}urea, Nimodipine and dexamethasone acetate. Then, anti-tumor components acting on Tyrosine 367 Cysteine-fibroblast growth factor receptor 4 were screened and identified from extracts of Ligusticum wallichii. Components from the extract were retained on the cell membrane chromatographic column. The retained fraction was directly eluted into high-performance liquid chromatography with mass spectrometry system for separation and identification. Finally, Levistolide A was identified as an active component from Ligusticum wallichii extracts. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide-formazan colorimetric assay revealed that Levistolide A inhibits proliferation of overexpressing the mutated receptor cells with dose-dependent manner. Phosphorylation of fibroblast growth factor receptor 4 was also decrease under Levistolide A treatment. Flex dock simulation verified that Levistolide A could bind with the tyrosine kinase domain of fibroblast growth factor receptor 4. Therefore, Levistolide A screened by the cell membrane chromatography combined with high-performance liquid chromatography and mass spectrometry can arrest cell growth. In conclusion, the two-dimensional high-performance liquid chromatography method can screen and identify potential anti-tumor ingredients which specifically act on the tyrosine kinase domain of the mutated fibroblast growth factor receptor 4. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Detection of epidermal growth factor receptor gene T790M mutation in cytology samples using the cobas® EGFR mutation test.

PubMed

Satouchi, Miyako; Tanaka, Hiroshi; Yoshioka, Hiroshige; Shimokawaji, Tadasuke; Mizuno, Keiko; Takeda, Koji; Yoshino, Ichiro; Seto, Takashi; Kurata, Takayasu; Tashiro, Naoki; Hagiwara, Koichi

2017-09-01

Detection of epidermal growth factor receptor (EGFR) gene mutations is essential in deciding therapeutic strategy in non-small cell lung cancer (NSCLC) patients at initial diagnosis. Moreover, in EGFR mutation-positive (EGFRm) NSCLC patients, re-biopsy at disease progression to clarify resistance mechanisms is also important. However, collecting histology samples is often difficult because of inaccessibility and invasiveness. In some cases, only cytology samples can be collected, and studies have reported that cytology samples are appropriate for EGFR gene mutation testing. The cobas ® EGFR Mutation Test (Roche Molecular Systems Inc., Branchburg, New Jersey, USA) is approved as a companion diagnostic for osimertinib, a third-generation EGFR-tyrosine kinase inhibitor approved in Japan. However, it is not clear whether the EGFR T790M mutation can be detected in cytology samples using this test. The primary objective of this study was to assess concordance of EGFR T790M gene mutation detection between histology and matched cytology samples using the cobas ® EGFR Mutation Test. We conducted a multicenter, observational study in Japan. Overall, 41 EGFRm NSCLC patients who had both histology and cytology samples collected at the same time at re-biopsy and with the results of EGFR mutation test using histology samples were enrolled. The EGFR mutation status of both sample types was tested using the cobas ® EGFR Mutation Test and the concordance rates were calculated. The EGFR T790M mutation detection rate in histology and cytology samples was 42.5% and 37.5%, respectively. The overall percent agreement between the histology and cytology samples was 91.7%. These data demonstrate that the cobas ® EGFR Mutation Test can detect the EGFR T790M mutation in both cytology and histology samples. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Is MPP a good prognostic factor in stage III lung adenocarcinoma with EGFR exon 19 mutation?

PubMed

Zhang, Tian; Wang, Jing; Su, Yanjun; Chen, Xi; Yan, Qingna; Li, Qi; Sun, Leina; Wang, Yuwen; Er, Puchun; Pang, Qingsong; Wang, Ping

2017-06-20

Epidermal growth factor receptor (EGFR) is a transmembrane glycoprotein encoded by a gene located in the short arm of chromosome 7. This study aimed to investigate the clinicopathologic characteristics of classic EGFR exon mutation in Chinese patients with TMN stage III lung adenocarcinoma who received radical surgery. A total of 1,801 lung adenocarcinomas were analyzed for mutations in EGFR; 35% exhibited mutation of classic EGFR exons. Clinical and pathologic characteristics of patients with EGFR exon 19 mutation were compared with those who harbored EGFR exon 21 mutation. Patients with EGFR exon 19 mutation had a higher overall survival (OS, p=0.023) than those harboring EGFR exon 21 mutation. Our results demonstrated that patients with a micropapillary pattern (MPP) pathologic type in EGFR exon 19 mutation had a higher OS (p=0.022), and patients with exon 19 mutation were more sensitive to EGFR-tyrosine kinase inhibitors (p=0.032). The results of the current study can be used in decision-making regarding the treatment of patients with classic EGFR exon mutations.

Epidermal growth factor receptor variant III mutations in lung tumorigenesis and sensitivity to tyrosine kinase inhibitors

PubMed Central

Ji, Hongbin; Zhao, Xiaojun; Yuza, Yuki; Shimamura, Takeshi; Li, Danan; Protopopov, Alexei; Jung, Boonim L.; McNamara, Kate; Xia, Huili; Glatt, Karen A.; Thomas, Roman K.; Sasaki, Hidefumi; Horner, James W.; Eck, Michael; Mitchell, Albert; Sun, Yangping; Al-Hashem, Ruqayyah; Bronson, Roderick T.; Rabindran, Sridhar K.; Discafani, Carolyn M.; Maher, Elizabeth; Shapiro, Geoffrey I.; Meyerson, Matthew; Wong, Kwok-Kin

2006-01-01

The tyrosine kinase inhibitors gefitinib (Iressa) and erlotinib (Tarceva) have shown anti-tumor activity in the treatment of non-small cell lung cancer (NSCLC). Dramatic and durable responses have occurred in NSCLC tumors with mutations in the tyrosine kinase domain of the epidermal growth factor receptor (EGFR). In contrast, these inhibitors have shown limited efficacy in glioblastoma, where a distinct EGFR mutation, the variant III (vIII) in-frame deletion of exons 2–7, is commonly found. In this study, we determined that EGFRvIII mutation was present in 5% (3/56) of analyzed human lung squamous cell carcinoma (SCC) but was not present in human lung adenocarcinoma (0/123). We analyzed the role of the EGFRvIII mutation in lung tumorigenesis and its response to tyrosine kinase inhibition. Tissue-specific expression of EGFRvIII in the murine lung led to the development of NSCLC. Most importantly, these lung tumors depend on EGFRvIII expression for maintenance. Treatment with an irreversible EGFR inhibitor, HKI-272, dramatically reduced the size of these EGFRvIII-driven murine tumors in 1 week. Similarly, Ba/F3 cells transformed with the EGFRvIII mutant were relatively resistant to gefitinib and erlotinib in vitro but proved sensitive to HKI-272. These findings suggest a therapeutic strategy for cancers harboring the EGFRvIII mutation. PMID:16672372

Epidermal growth factor receptor T790M testing in progressed lung cancer: A review of sensitive methods for analysis of tissue and liquid biopsy samples.

PubMed

Chougule, A; Basak, S

2017-12-01

Lung cancer is one of the major causes of mortality worldwide and is on the rise in India. The identification of epidermal growth factor receptor (EGFR) mutations in nonsmall cell lung cancer (NSCLC) has paved the way for personalized therapy in lung cancer with EGFR-tyrosine kinase inhibitors (TKIs). Despite the proven efficacy of EGFR-TKIs in patients harboring EGFR mutations, their clinical utility is limited by the development of acquired resistance mechanisms by the tumor cells. T790M mutation accounts for 60% of all resistance mechanisms to EGFR TKIs and is responsible for treatment failure with first- and second-generation TKIs. With the development of novel therapeutic agents such as osimertinib to overcome this resistance mechanism, it is essential to detect patients harboring T790M mutation. There are several limitations with the use of tissue biopsy specimens for molecular testing such as poor quality and quantity of sample, tumor heterogeneity, occurrence of complications, and issues with repeat biopsy. Liquid biopsy offers a noninvasive approach that can be used for diagnostic purposes as well as for monitoring treatment response and evaluation of resistance mechanisms. This review focuses on the methods for molecular testing of tissue and liquid biopsy specimens for EGFR mutations, particularly EGFR T790M mutation.

Osimertinib: A third-generation tyrosine kinase inhibitor for treatment of epidermal growth factor receptor-mutated non-small cell lung cancer with the acquired Thr790Met mutation.

PubMed

Bollinger, Meredith K; Agnew, Amanda S; Mascara, Gerard P

2017-01-01

Osimertinib is a third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) approved for the treatment of metastatic EGFR T790M mutation-positive non-small cell lung cancer (NSCLC) in patients failing previous TKI therapy. The T790M mutation is an acquired resistance mechanism found in over half of patients with NSCLC progressing on first-generation TKIs. First- and second-generation TKIs do not inhibit the T790M mutation at clinically relevant concentrations. Osimertinib is selective for mutated forms of EGFR, including the TKI-sensitizing mutations L858R and exon 19 deletions, as well as the acquired T790M resistance mutation. In a trial comparing osimertinib to platinum doublet therapy among patients with the T790M mutation progressing on first-line TKI therapy, median progression-free survival was significantly longer in patients receiving osimertinib. Osimertinib has a favorable safety profile compared to platinum-doublet chemotherapy. Common adverse events include diarrhea, skin rash, dry skin, and paronychia; however, because it spares wild-type EGFR, these toxicities appear to occur with less frequency and severity compared to other TKIs. Serious, but rare, adverse events include pneumonitis, interstitial lung disease-like events, QT interval prolongation, and reduced ejection fraction. Osimertinib has the unique ability to distribute readily into brain tissue compared with other TKIs, giving it a potential role in the treatment and/or prevention of CNS metastases; future studies are warranted in this area. An ongoing study evaluating osimertinib versus first-generation TKIs as first-line treatment for patients with EGFR mutation-positive NSCLC may help to define the role of osimertinib as front-line therapy.

Activating mutations in the tyrosine kinase domain of the epidermal growth factor receptor are associated with improved survival in gefitinib-treated chemorefractory lung adenocarcinomas.

PubMed

Taron, Miguel; Ichinose, Yukito; Rosell, Rafael; Mok, Tony; Massuti, Bartomeu; Zamora, Lurdes; Mate, Jose Luis; Manegold, Christian; Ono, Mayumi; Queralt, Cristina; Jahan, Thierry; Sanchez, Jose Javier; Sanchez-Ronco, Maria; Hsue, Victor; Jablons, David; Sanchez, Jose Miguel; Moran, Teresa

2005-08-15

Activating mutations in the tyrosine kinase domain of the epidermal growth factor receptor (EGFR) confer a strong sensitivity to gefitinib, a selective tyrosine kinase inhibitor of EGFR. We examined EGFR mutations at exons 18, 19, and 21 in tumor tissue from 68 gefitinib-treated, chemorefractory, advanced non-small cell lung cancer patients from the United States, Europe, and Asia and in a highly gefitinib-sensitive non-small cell lung cancer cell line and correlated their presence with response and survival. In addition, in a subgroup of 28 patients for whom the remaining tumor tissue was available, we examined the relationship among EGFR mutations, CA repeats in intron 1 of EGFR, EGFR and caveolin-1 mRNA levels, and increased EGFR gene copy numbers. Seventeen patients had EGFR mutations, all of which were in lung adenocarcinomas. Radiographic response was observed in 16 of 17 (94.1%) patients harboring EGFR mutations, in contrast with 6 of 51 (12.6%) with wild-type EGFR (P < 0.0001). Probability of response increased significantly in never smokers, patients receiving a greater number of prior chemotherapy regimens, Asians, and younger patients. Median survival was not reached for patients with EGFR mutations and was 9.9 months for those with wild-type EGFR (P = 0.001). EGFR mutations tended to be associated with increased numbers of CA repeats and increased EGFR gene copy numbers but not with EGFR and caveolin-1 mRNA overexpression (P = not significant). The presence of EGFR mutations is a major determinant of gefitinib response, and targeting EGFR should be considered in preference to chemotherapy as first-line treatment in lung adenocarcinomas that have demonstrable EGFR mutations.

Interstitial Lung Disease Induced by Osimertinib for Epidermal Growth Factor Receptor (EGFR) T790M-positive Non-small Cell Lung Cancer.

PubMed

Matsumoto, Yoshiya; Kawaguchi, Tomoya; Yamamoto, Norio; Sawa, Kenji; Yoshimoto, Naoki; Suzumura, Tomohiro; Watanabe, Tetsuya; Mitsuoka, Shigeki; Asai, Kazuhisa; Kimura, Tatsuo; Yoshimura, Naruo; Kuwae, Yuko; Hirata, Kazuto

2017-09-01

A 75-year-old man with stage IV lung adenocarcinoma was treated with osimertinib due to disease progression despite having been administered erlotinib. Both an epidermal growth factor receptor (EGFR) L858R mutation on exon 21 and a T790M mutation on exon 20 were detected in a specimen from a recurrent primary tumor. Five weeks after osimertinib initiation, he developed general fatigue and dyspnea. Chest computed tomography scan revealed diffuse ground glass opacities and consolidation on both lungs. An analysis of the bronchoalveolar lavage fluid revealed marked lymphocytosis, and a transbronchial lung biopsy specimen showed a thickened interstitium with fibrosis and prominent lymphocytic infiltration. We diagnosed the patient to have interstitial lung disease induced by osimertinib.

Interstitial Lung Disease Induced by Osimertinib for Epidermal Growth Factor Receptor (EGFR) T790M-positive Non-small Cell Lung Cancer

PubMed Central

Matsumoto, Yoshiya; Kawaguchi, Tomoya; Yamamoto, Norio; Sawa, Kenji; Yoshimoto, Naoki; Suzumura, Tomohiro; Watanabe, Tetsuya; Mitsuoka, Shigeki; Asai, Kazuhisa; Kimura, Tatsuo; Yoshimura, Naruo; Kuwae, Yuko; Hirata, Kazuto

2017-01-01

A 75-year-old man with stage IV lung adenocarcinoma was treated with osimertinib due to disease progression despite having been administered erlotinib. Both an epidermal growth factor receptor (EGFR) L858R mutation on exon 21 and a T790M mutation on exon 20 were detected in a specimen from a recurrent primary tumor. Five weeks after osimertinib initiation, he developed general fatigue and dyspnea. Chest computed tomography scan revealed diffuse ground glass opacities and consolidation on both lungs. An analysis of the bronchoalveolar lavage fluid revealed marked lymphocytosis, and a transbronchial lung biopsy specimen showed a thickened interstitium with fibrosis and prominent lymphocytic infiltration. We diagnosed the patient to have interstitial lung disease induced by osimertinib. PMID:28794368

Analysis of the relationship between lung cancer drug response level and atom connectivity dynamics based on trimmed Delaunay triangulation

NASA Astrophysics Data System (ADS)

Zou, Bin; Wang, Debby D.; Ma, Lichun; Chen, Lijiang; Yan, Hong

2016-05-01

Epidermal growth factor receptor (EGFR) mutation is a pathogenic factor of non-small cell lung cancer (NSCLC). Tyrosine kinase inhibitors (TKIs), such as gefitinib, are widely used in NSCLC treatment. In this work, we investigated the relationship between the number of EGFR residues connected with gefitinib and the response level for each EGFR mutation type. Three-dimensional trimmed Delaunay triangulation was applied to construct connections between EGFR residues and gefitinib atoms. Through molecular dynamics (MD) simulations, we discovered that when the number of EGFR residues connected with gefitinib increases, the response level of the corresponding EGFR mutation tends to descend.

Comprehensive molecular screening by next generation sequencing reveals a distinctive mutational profile of KIT/PDGFRA genes and novel genomic alterations: results from a 20-year cohort of patients with GIST from north-western Greece.

PubMed

Mavroeidis, Leonidas; Metaxa-Mariatou, Vassiliki; Papoudou-Bai, Alexandra; Lampraki, Angeliki Maria; Kostadima, Lida; Tsinokou, Ilias; Zarkavelis, George; Papadaki, Alexandra; Petrakis, Dimitrios; Gκoura, Stefania; Kampletsas, Eleftherios; Nasioulas, George; Batistatou, Anna; Pentheroudakis, George

2018-01-01

Gastrointestinal stromal tumours (GIST) are mesenchymal neoplasms that usually carry an activating mutation in KIT or platelet-derived growth factor receptor alpha ( PDGFRA ) genes with predictive and prognostic significance. We investigated the extended mutational status of GIST in a patient population of north-western Greece in order to look at geopraphic/genotypic distinctive traits. Clinicopathological and molecular data of 38 patients diagnosed from 1996 to 2016 with GIST in the region of Epirus in Greece were retrospectively assessed. Formalin-fixed paraffin-embedded tumours were successfully analysed for mutations in 54 genes with oncogenic potential. Next generation sequencing was conducted by using the Ion AmpliSeqCancer Hotspot Panel V.2 for DNA analysis (Thermofisher Scientific). Among 38 tumours, 24 (63.16%) and seven (18.42%) of the tumours harboured mutations in the KIT and PDGFRA genes, respectively, while seven (18.42%) tumours were negative for either KIT or PDGFRA mutation. No mutations were detected in five (13.16%) cases. Concomitant mutations of BRAF and fibroblast growth factor receptor 3 ( FGFR3 ) genes were observed in two patients with KIT gene mutation. Two patients with KIT / PDGFRA wild-type GIST had mutations in either KRAS or phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha ( PIK3CA ) genes. There was no significant survival difference regarding the exonic site of mutation in either KIT or PDGFRA gene. The presence of a mutation in pathway effectors downstream of KIT or PDGFRA , such as BRAF , KRAS or PIK3CA , was associated with poor prognosis. Adverse prognosticators were also high mitotic index and the advanced disease status at diagnosis. We report comparable incidence of KIT and PDGFRA mutation in patients with GIST from north-western Greece as compared with cohorts from other regions. Interestingly, we identified rare mutations on RAS , BRAF and PIK3CA genes in patients with poor prognosis.

Improved growth response of antibody/receptor chimera attained by the engineering of transmembrane domain.

PubMed

Kawahara, Masahiro; Ogo, Yuko; Ueda, Hiroshi; Nagamune, Teruyuki

2004-10-01

Structure-based design of antibody/cytokine receptor chimeras has permitted a growth signal transduction in response to non-natural ligands such as fluorescein-conjugated BSA as mimicry of cytokine-cytokine receptor systems. However, while tight on/off regulation is observed in the natural cytokine receptor systems, many chimeras constructed to date showed residual growth-promoting activity in the absence of ligands. Here we tried to reduce the basal growth signal intensity from a chimera by engineering the transmembrane domain (TM) that is thought to be involved in the interchain interaction of natural cytokine receptors. When the retroviral vectors encoding the chimeras with either the wild-type erythropoietin receptor (EpoR) TM or the one bearing two mutations in the leucine zipper motif were transduced to non-strictly interleukin-6-dependent 7TD1 cells, a tight antigen-dependent on/off regulation was attained, also demonstrating the first antigen-mediated genetically modified cell amplification of non-strictly factor-dependent cells. The results clearly indicate that the TM mutation is an effective means to improve the growth response of the antibody/receptor chimera.

Retrospective study of adjuvant icotinib in postoperative lung cancer patients harboring epidermal growth factor receptor mutations

PubMed Central

Yao, Shuyang; Zhi, Xiuyi; Wang, Ruotian; Qian, Kun; Hu, Mu

2016-01-01

Background Epidermal growth factor receptor (EGFR) mutations occur in about 50% of Asian patients with non‐small cell lung cancer (NSCLC). Patients with advanced NSCLC and EGFR mutations derive clinical benefit from treatment with EGFR‐tyrosine kinase inhibitors (TKIs). This study assessed the efficacy and safety of adjuvant icotinib without chemotherapy in EGFR‐mutated NSCLC patients undergoing resection of stage IB–IIIA. Methods Our retrospective study enrolled 20 patients treated with icotinib as adjuvant therapy. Survival factors were evaluated by univariate and Cox regression analysis. Results The median follow‐up time was 30 months (range 24–41). At the data cut‐off, five patients (25%) had recurrence or metastasis and one patient had died of the disease. The two‐year disease‐free survival (DFS) rate was 85%. No recurrence occurred in the high‐risk stage IB subgroup during the follow‐up period. In univariate analysis, the micropapillary pattern had a statistically significant effect on DFS (P = 0.040). Multivariate logistic regression analysis showed that there was no independent predictor. Drug related adverse events (AEs) occurred in nine patients (45.0%). The most common AEs were skin‐related events and diarrhea, but were relatively mild. No grade 3 AEs or occurrences of intolerable toxicity were observed. Conclusions Icotinib as adjuvant therapy is effective in patients harboring EGFR mutations after complete resection, with an acceptable AE profile. Further trials with larger sample sizes might confirm the efficiency of adjuvant TKI in selected patients. PMID:27766784

Atypical radiological findings in achondroplasia with uncommon mutation of the fibroblast growth factor receptor-3 (FGFR-3) gene (Gly to Cys transition at codon 375)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nishimuri, Gen; Fukushima, Yoshimitsu; Ohashi, Hirofumi

1995-11-20

The recent discovery of mutations in the FGFR-3 (fibroblast growth factor receptor-3) gene (FGFR3) as the cause of achondroplasia has provided new insight into understanding genetic diseases. It was surprising from the viewpoint of molecular genetics that most patients with achondroplasia showed the same mutation at nucleotide 1138, leading to a single amino acid substitution from glycine to arginine at codon 380 (Gly380Arg). All 39 patients examined by two groups had the Gly380Arg; 38 patients and the other demonstrated a G to A and a G to C transition at nucleotide 1138, respectively. Subsequently another group disclosed a G tomore » A transition at the same nucleotide 1138 in 21/23 patients of diverse ethnic origin, although mutations were not identified in two patients. To date, a total of 193 patients with the mutation of the G380Arg have been reported; a single patient with another mutation resulting in a substitution from glycine to cysteine at codon 375 (Gly375Cys) has been described. The presence of this common mutation is consistent with the clinical fact that achondroplastic individuals show less phenotypic variability than is unusual for autosomal dominant diseases. We encountered a Japanese boy with the Gly375Cys. His mother with achondroplasia has the same mutation. The molecular investigation of these patients was reported elsewhere. Here we report the clinical and radiological findings in this boy who demonstrated some atypical manifestations from those of typical achondroplasia. 8 refs., 1 fig.« less

Epidermal growth factor receptor gene mutation defines distinct subsets among small adenocarcinomas of the lung.

PubMed

Haneda, Hiroshi; Sasaki, Hidefumi; Shimizu, Shigeki; Endo, Katsuhiko; Suzuki, Eriko; Yukiue, Haruhiro; Kobayashi, Yoshihiro; Yano, Motoki; Fujii, Yoshitaka

2006-04-01

Epidermal growth factor receptor (EGFR) gene mutations are frequently detected in lung cancer, especially in adenocarcinoma, in females, and non-smoking patients. EGFR mutations are closely associated with clinical response to EGFR tyrosine kinase inhibitor. Bronchioloalveolar carcinoma (BAC) appearance is a good predictor of response to this agent. Noguchi et al. subdivided small peripheral adenocarcinoma of the lung into two groups. One group was characterized with tumor cell growth replacing the normal alveolar cells with varying degree of fibrosis (types A-C), and the other shows non-replacing and destructive growth (types D-F). Using probes for the 13 mutations which have been previously described, we have genotyped the EGFR gene status in surgically resected atypical adenomatous hyperplasias (AAH) and small peripheral adenocarcinomas up to 2 cm in diameter using TaqMan PCR assay. In 95 small-sized adenocarcinomas, the EGFR mutations were detected in 37 patients (38.9%), and no mutations were found in five AAHs. In small peripheral adenocarcinomas, EGFR mutations were found 47.1% of types A, B, or C adenocarcinomas; it was less frequent (16%) in Noguchi's types D, E or F adenocarcinomas. These results suggest that type D, F adenocarcinomas are not derived from the less malignant types A-C adenocarcinomas; rather, they have arisen de novo by distinct mechanisms. Although types A and B adenocarcinomas are almost 100% cured by surgery, some type C adenocarcinoma show lymph node metastasis and relapse. EGFR mutation analysis may help identify patients who will respond to treatment with tyrosine kinase inhibitors, e.g., gefitinib.

Association of SMAD4 mutation with patient demographics, tumor characteristics, and clinical outcomes in colorectal cancer.

PubMed

Mehrvarz Sarshekeh, Amir; Advani, Shailesh; Overman, Michael J; Manyam, Ganiraju; Kee, Bryan K; Fogelman, David R; Dasari, Arvind; Raghav, Kanwal; Vilar, Eduardo; Manuel, Shanequa; Shureiqi, Imad; Wolff, Robert A; Patel, Keyur P; Luthra, Raja; Shaw, Kenna; Eng, Cathy; Maru, Dipen M; Routbort, Mark J; Meric-Bernstam, Funda; Kopetz, Scott

2017-01-01

SMAD4 is an essential mediator in the transforming growth factor-β pathway. Sporadic mutations of SMAD4 are present in 2.1-20.0% of colorectal cancers (CRCs) but data are limited. In this study, we aimed to evaluate clinicopathologic characteristics, prognosis, and clinical outcome associated with this mutation in CRC cases. Data for patients with metastatic or unresectable CRC who underwent genotyping for SMAD4 mutation and received treatment at The University of Texas MD Anderson Cancer Center from 2000 to 2014 were reviewed. Their tumors were sequenced using a hotspot panel predicted to cover 80% of the reported SMAD4 mutations, and further targeted resequencing that included full-length SMAD4 was performed on mutated tumors using a HiSeq sequencing system. Using The Cancer Genome Atlas data on CRC, the characteristics of SMAD4 and transforming growth factor-β pathway mutations were evaluated according to different consensus molecular subtypes of CRC. Among 734 patients with CRC, 90 (12%) had SMAD4 mutations according to hotspot testing. SMAD4 mutation was associated with colon cancer more so than with rectal cancer (odds ratio 2.85; p<0.001), female sex (odds ratio 1.71; p = 0.02), and shorter overall survival than in wild-type SMAD4 cases (median, 29 months versus 56 months; hazard ratio 2.08; p<0.001 [log-rank test]). SMAD4 mutation was not associated with age, stage at presentation, colonic location, distant metastasis, or tumor grade. A subset of patients with metastatic CRC (n = 44) wild-type for KRAS, NRAS, and BRAF who received anti-epidermal growth factor receptor therapy with mutated SMAD4 (n = 13) had shorter progression-free survival duration than did patients wild-type for SMAD4 (n = 31) (median, 111 days versus 180 days; p = 0.003 [log-rank test]). Full-length sequencing confirmed that missense mutations at R361 and P356 in the MH2 domain were the most common SMAD4 alterations. In The Cancer Genome Atlas data, SMAD4 mutation frequently occurred with KRAS, NRAS, and BRAF mutations and was more common in patients with the consensus molecular subtype 3 of CRC than in those with the other 3 subtypes. This is one of the largest retrospective studies to date characterizing SMAD4 mutations in CRC patients and demonstrates the prognostic role and lack of response of CRC to anti-epidermal growth factor receptor therapy. Further studies are required to validate these findings and the role of SMAD4 mutation in CRC.

Association of SMAD4 mutation with patient demographics, tumor characteristics, and clinical outcomes in colorectal cancer

PubMed Central

Sarshekeh, Amir Mehrvarz; Advani, Shailesh; Overman, Michael J.; Manyam, Ganiraju; Kee, Bryan K.; Fogelman, David R.; Dasari, Arvind; Raghav, Kanwal; Vilar, Eduardo; Manuel, Shanequa; Shureiqi, Imad; Wolff, Robert A.; Patel, Keyur P.; Luthra, Raja; Shaw, Kenna; Eng, Cathy; Maru, Dipen M.; Routbort, Mark J.; Meric-Bernstam, Funda

2017-01-01

SMAD4 is an essential mediator in the transforming growth factor-β pathway. Sporadic mutations of SMAD4 are present in 2.1–20.0% of colorectal cancers (CRCs) but data are limited. In this study, we aimed to evaluate clinicopathologic characteristics, prognosis, and clinical outcome associated with this mutation in CRC cases. Data for patients with metastatic or unresectable CRC who underwent genotyping for SMAD4 mutation and received treatment at The University of Texas MD Anderson Cancer Center from 2000 to 2014 were reviewed. Their tumors were sequenced using a hotspot panel predicted to cover 80% of the reported SMAD4 mutations, and further targeted resequencing that included full-length SMAD4 was performed on mutated tumors using a HiSeq sequencing system. Using The Cancer Genome Atlas data on CRC, the characteristics of SMAD4 and transforming growth factor-β pathway mutations were evaluated according to different consensus molecular subtypes of CRC. Among 734 patients with CRC, 90 (12%) had SMAD4 mutations according to hotspot testing. SMAD4 mutation was associated with colon cancer more so than with rectal cancer (odds ratio 2.85; p<0.001), female sex (odds ratio 1.71; p = 0.02), and shorter overall survival than in wild-type SMAD4 cases (median, 29 months versus 56 months; hazard ratio 2.08; p<0.001 [log-rank test]). SMAD4 mutation was not associated with age, stage at presentation, colonic location, distant metastasis, or tumor grade. A subset of patients with metastatic CRC (n = 44) wild-type for KRAS, NRAS, and BRAF who received anti-epidermal growth factor receptor therapy with mutated SMAD4 (n = 13) had shorter progression-free survival duration than did patients wild-type for SMAD4 (n = 31) (median, 111 days versus 180 days; p = 0.003 [log-rank test]). Full-length sequencing confirmed that missense mutations at R361 and P356 in the MH2 domain were the most common SMAD4 alterations. In The Cancer Genome Atlas data, SMAD4 mutation frequently occurred with KRAS, NRAS, and BRAF mutations and was more common in patients with the consensus molecular subtype 3 of CRC than in those with the other 3 subtypes. This is one of the largest retrospective studies to date characterizing SMAD4 mutations in CRC patients and demonstrates the prognostic role and lack of response of CRC to anti-epidermal growth factor receptor therapy. Further studies are required to validate these findings and the role of SMAD4 mutation in CRC. PMID:28267766

Somatic mutations affect key pathways in lung adenocarcinoma

PubMed Central

Ding, Li; Getz, Gad; Wheeler, David A.; Mardis, Elaine R.; McLellan, Michael D.; Cibulskis, Kristian; Sougnez, Carrie; Greulich, Heidi; Muzny, Donna M.; Morgan, Margaret B.; Fulton, Lucinda; Fulton, Robert S.; Zhang, Qunyuan; Wendl, Michael C.; Lawrence, Michael S.; Larson, David E.; Chen, Ken; Dooling, David J.; Sabo, Aniko; Hawes, Alicia C.; Shen, Hua; Jhangiani, Shalini N.; Lewis, Lora R.; Hall, Otis; Zhu, Yiming; Mathew, Tittu; Ren, Yanru; Yao, Jiqiang; Scherer, Steven E.; Clerc, Kerstin; Metcalf, Ginger A.; Ng, Brian; Milosavljevic, Aleksandar; Gonzalez-Garay, Manuel L.; Osborne, John R.; Meyer, Rick; Shi, Xiaoqi; Tang, Yuzhu; Koboldt, Daniel C.; Lin, Ling; Abbott, Rachel; Miner, Tracie L.; Pohl, Craig; Fewell, Ginger; Haipek, Carrie; Schmidt, Heather; Dunford-Shore, Brian H.; Kraja, Aldi; Crosby, Seth D.; Sawyer, Christopher S.; Vickery, Tammi; Sander, Sacha; Robinson, Jody; Winckler, Wendy; Baldwin, Jennifer; Chirieac, Lucian R.; Dutt, Amit; Fennell, Tim; Hanna, Megan; Johnson, Bruce E.; Onofrio, Robert C.; Thomas, Roman K.; Tonon, Giovanni; Weir, Barbara A.; Zhao, Xiaojun; Ziaugra, Liuda; Zody, Michael C.; Giordano, Thomas; Orringer, Mark B.; Roth, Jack A.; Spitz, Margaret R.; Wistuba, Ignacio I.; Ozenberger, Bradley; Good, Peter J.; Chang, Andrew C.; Beer, David G.; Watson, Mark A.; Ladanyi, Marc; Broderick, Stephen; Yoshizawa, Akihiko; Travis, William D.; Pao, William; Province, Michael A.; Weinstock, George M.; Varmus, Harold E.; Gabriel, Stacey B.; Lander, Eric S.; Gibbs, Richard A.; Meyerson, Matthew; Wilson, Richard K.

2009-01-01

Determining the genetic basis of cancer requires comprehensive analyses of large collections of histopathologically well-classified primary tumours. Here we report the results of a collaborative study to discover somatic mutations in 188 human lung adenocarcinomas. DNA sequencing of 623 genes with known or potential relationships to cancer revealed more than 1,000 somatic mutations across the samples. Our analysis identified 26 genes that are mutated at significantly high frequencies and thus are probably involved in carcinogenesis. The frequently mutated genes include tyrosine kinases, among them the EGFR homologue ERBB4; multiple ephrin receptor genes, notably EPHA3; vascular endothelial growth factor receptor KDR; and NTRK genes. These data provide evidence of somatic mutations in primary lung adenocarcinoma for several tumour suppressor genes involved in other cancers—including NF1, APC, RB1 and ATM—and for sequence changes in PTPRD as well as the frequently deleted gene LRP1B. The observed mutational profiles correlate with clinical features, smoking status and DNA repair defects. These results are reinforced by data integration including single nucleotide polymorphism array and gene expression array. Our findings shed further light on several important signalling pathways involved in lung adenocarcinoma, and suggest new molecular targets for treatment. PMID:18948947

A mutation in the insulin receptor gene that impairs transport of the receptor to the plasma membrane and causes insulin-resistant diabetes.

PubMed Central

Accili, D; Frapier, C; Mosthaf, L; McKeon, C; Elbein, S C; Permutt, M A; Ramos, E; Lander, E; Ullrich, A; Taylor, S I

1989-01-01

Insulin binds to a receptor on the cell surface, thereby triggering a biological response within the target cell. Mutations in the insulin receptor gene can render the cell resistant to the biological action of insulin. We have studied a family in which two sisters have a genetic form of insulin-resistant diabetes mellitus. The technique of homozygosity mapping has been used to demonstrate that the mutation causing diabetes in this consanguineous family is genetically linked to the insulin receptor gene. The two insulin-resistant sisters are homozygous for a mutation encoding substitution of valine for phenylalanine at position 382 in the alpha-subunit of the insulin receptor. Transfection of mutant insulin receptor cDNA into NIH3T3 cells demonstrated that the Val382 mutation impaired post-translational processing and retarded transport of the insulin receptor to the plasma membrane. Thus, the mutation causes insulin resistance by decreasing the number of insulin receptors on the surface of the patients' cells. Images PMID:2573522

Effectiveness and cost-effectiveness of erlotinib versus gefitinib in first-line treatment of epidermal growth factor receptor-activating mutation-positive non-small-cell lung cancer patients in Hong Kong.

PubMed

Lee, Vivian W Y; Schwander, Bjoern; Lee, Victor H F

2014-06-01

To compare the effectiveness and cost-effectiveness of erlotinib versus gefitinib as first-line treatment of epidermal growth factor receptor-activating mutation-positive non-small-cell lung cancer patients. DESIGN. Indirect treatment comparison and a cost-effectiveness assessment. Hong Kong. Those having epidermal growth factor receptor-activating mutation-positive non-small-cell lung cancer. Erlotinib versus gefitinib use was compared on the basis of four relevant Asian phase-III randomised controlled trials: one for erlotinib (OPTIMAL) and three for gefitinib (IPASS; NEJGSG; WJTOG). The cost-effectiveness assessment model simulates the transition between the health states: progression-free survival, progression, and death over a lifetime horizon. The World Health Organization criterion (incremental cost-effectiveness ratio <3 times of gross domestic product/capita:

Epidermal Growth Factor Receptor (EGFR) mutation analysis, gene expression profiling and EGFR protein expression in primary prostate cancer

PubMed Central

2011-01-01

Background Activating mutations of the epidermal growth factor receptor (EGFR) confer sensitivity to the tyrosine kinase inhibitors (TKi), gefitinib and erlotinib. We analysed EGFR expression, EGFR mutation status and gene expression profiles of prostate cancer (PC) to supply a rationale for EGFR targeted therapies in this disease. Methods Mutational analysis of EGFR TK domain (exons from 18 to 21) and immunohistochemistry for EGFR were performed on tumour tissues derived from radical prostatectomy from 100 PC patients. Gene expression profiling using oligo-microarrays was also carried out in 51 of the PC samples. Results EGFR protein overexpression (EGFRhigh) was found in 36% of the tumour samples, and mutations were found in 13% of samples. Patients with EGFRhigh tumours experienced a significantly increased risk of biochemical relapse (hazard ratio-HR 2.52, p=0.02) compared with patients with tumours expressing low levels of EGFR (EGFRlow). Microarray analysis did not reveal any differences in gene expression between EGFRhigh and EGFRlow tumours. Conversely, in EGFRhigh tumours, we were able to identify a 79 gene signature distinguishing mutated from non-mutated tumours. Additionally, 29 genes were found to be differentially expressed between mutated/EGFRhigh (n=3) and mutated/EGFRlow tumours (n=5). Four of the down-regulated genes, U19/EAF2, ABCC4, KLK3 and ANXA3 and one of the up-regulated genes, FOXC1, are involved in PC progression. Conclusions Based on our findings, we hypothesize that accurate definition of the EGFR status could improve prognostic stratification and we suggest a possible role for EGFR-directed therapies in PC patients. Having been generated in a relatively small sample of patients, our results warrant confirmation in larger series. PMID:21266046

Epidermal Growth Factor Receptor (EGFR) mutation analysis, gene expression profiling and EGFR protein expression in primary prostate cancer.

PubMed

Peraldo-Neia, Caterina; Migliardi, Giorgia; Mello-Grand, Maurizia; Montemurro, Filippo; Segir, Raffaella; Pignochino, Ymera; Cavalloni, Giuliana; Torchio, Bruno; Mosso, Luciano; Chiorino, Giovanna; Aglietta, Massimo

2011-01-25

Activating mutations of the epidermal growth factor receptor (EGFR) confer sensitivity to the tyrosine kinase inhibitors (TKi), gefitinib and erlotinib. We analysed EGFR expression, EGFR mutation status and gene expression profiles of prostate cancer (PC) to supply a rationale for EGFR targeted therapies in this disease. Mutational analysis of EGFR TK domain (exons from 18 to 21) and immunohistochemistry for EGFR were performed on tumour tissues derived from radical prostatectomy from 100 PC patients. Gene expression profiling using oligo-microarrays was also carried out in 51 of the PC samples. EGFR protein overexpression (EGFRhigh) was found in 36% of the tumour samples, and mutations were found in 13% of samples. Patients with EGFRhigh tumours experienced a significantly increased risk of biochemical relapse (hazard ratio-HR 2.52, p=0.02) compared with patients with tumours expressing low levels of EGFR (EGFRlow). Microarray analysis did not reveal any differences in gene expression between EGFRhigh and EGFRlow tumours. Conversely, in EGFRhigh tumours, we were able to identify a 79 gene signature distinguishing mutated from non-mutated tumours. Additionally, 29 genes were found to be differentially expressed between mutated/EGFRhigh (n=3) and mutated/EGFRlow tumours (n=5). Four of the down-regulated genes, U19/EAF2, ABCC4, KLK3 and ANXA3 and one of the up-regulated genes, FOXC1, are involved in PC progression. Based on our findings, we hypothesize that accurate definition of the EGFR status could improve prognostic stratification and we suggest a possible role for EGFR-directed therapies in PC patients. Having been generated in a relatively small sample of patients, our results warrant confirmation in larger series.

Single-molecule detection of epidermal growth factor receptor mutations in plasma by microfluidics digital PCR in non-small cell lung cancer patients.

PubMed

Yung, Tony K F; Chan, K C Allen; Mok, Tony S K; Tong, Joanna; To, Ka-Fai; Lo, Y M Dennis

2009-03-15

We aim to develop a digital PCR-based method for the quantitative detection of the two common epidermal growth factor receptor (EGFR) mutations (in-frame deletion at exon 19 and L858R at exon 21) in the plasma and tumor tissues of patients suffering from non-small cell lung cancers. These two mutations account for >85% of clinically important EGFR mutations associated with responsiveness to tyrosine kinase inhibitors. DNA samples were analyzed using a microfluidics system that simultaneously performed 9,180 PCRs at nanoliter scale. A single-mutant DNA molecule in a clinical specimen could be detected and the quantities of mutant and wild-type sequences were precisely determined. Exon 19 deletion and L858R mutation were detectable in 6 (17%) and 9 (26%) of 35 pretreatment plasma samples, respectively. When compared with the sequencing results of the tumor samples, the sensitivity and specificity of plasma EGFR mutation analysis were 92% and 100%, respectively. The plasma concentration of the mutant sequences correlated well with the clinical response. Decreased concentration was observed in all patients with partial or complete clinical remission, whereas persistence of mutation was observed in a patient with cancer progression. In one patient, tyrosine kinase inhibitor was stopped after an initial response and the tumor-associated EGFR mutation reemerged 4 weeks after stopping treatment. The sensitive detection and accurate quantification of low abundance EGFR mutations in tumor tissues and plasma by microfluidics digital PCR would be useful for predicting treatment response, monitoring disease progression and early detection of treatment failure associated with acquired drug resistance.

Congenital hypogonadotropic hypogonadism with split hand/foot malformation: a clinical entity with a high frequency of FGFR1 mutations.

PubMed

Villanueva, Carine; Jacobson-Dickman, Elka; Xu, Cheng; Manouvrier, Sylvie; Dwyer, Andrew A; Sykiotis, Gerasimos P; Beenken, Andrew; Liu, Yang; Tommiska, Johanna; Hu, Youli; Tiosano, Dov; Gerard, Marion; Leger, Juliane; Drouin-Garraud, Valérie; Lefebvre, Hervé; Polak, Michel; Carel, Jean-Claude; Phan-Hug, Franziska; Hauschild, Michael; Plummer, Lacey; Rey, Jean-Pierre; Raivio, Taneli; Bouloux, Pierre; Sidis, Yisrael; Mohammadi, Moosa; de Roux, Nicolas; Pitteloud, Nelly

2015-08-01

Congenital hypogonadotropic hypogonadism (CHH) and split hand/foot malformation (SHFM) are two rare genetic conditions. Here we report a clinical entity comprising the two. We identified patients with CHH and SHFM through international collaboration. Probands and available family members underwent phenotyping and screening for FGFR1 mutations. The impact of identified mutations was assessed by sequence- and structure-based predictions and/or functional assays. We identified eight probands with CHH with (n = 3; Kallmann syndrome) or without anosmia (n = 5) and SHFM, seven of whom (88%) harbor FGFR1 mutations. Of these seven, one individual is homozygous for p.V429E and six individuals are heterozygous for p.G348R, p.G485R, p.Q594*, p.E670A, p.V688L, or p.L712P. All mutations were predicted by in silico analysis to cause loss of function. Probands with FGFR1 mutations have severe gonadotropin-releasing hormone deficiency (absent puberty and/or cryptorchidism and/or micropenis). SHFM in both hands and feet was observed only in the patient with the homozygous p.V429E mutation; V429 maps to the fibroblast growth factor receptor substrate 2α binding domain of FGFR1, and functional studies of the p.V429E mutation demonstrated that it decreased recruitment and phosphorylation of fibroblast growth factor receptor substrate 2α to FGFR1, thereby resulting in reduced mitogen-activated protein kinase signaling. FGFR1 should be prioritized for genetic testing in patients with CHH and SHFM because the likelihood of a mutation increases from 10% in the general CHH population to 88% in these patients.

Exclusive mutation in epidermal growth factor receptor gene, HER-2, and KRAS, and synchronous methylation of nonsmall cell lung cancer.

PubMed

Suzuki, Makoto; Shigematsu, Hisayuki; Iizasa, Toshihiko; Hiroshima, Kenzo; Nakatani, Yukio; Minna, John D; Gazdar, Adi F; Fujisawa, Takehiko

2006-05-15

Both genetic and epigenetic changes in nonsmall cell lung cancer (NSCLC) are known to be a common event. Mutations in the epidermal growth factor receptor gene (EGFR), HER-2, and KRAS and the methylation profile of 9 genes for NSCLC were analyzed and correlated with clinical and histologic data. Thirty-nine EGFR, 4 HER-2, and 6 KRAS mutations were found in 150 NSCLC cases, with the methylation percentages of the genes ranging from 13% to 54%. Most mutations were present in adenocarcinomas, but mutations of the 3 genes were never found to be present in individual tumors. The frequency of methylation for all the genes was correlated with the Methylation Index, a reflection of the overall methylation pattern (all genes, P< or = .01), supporting the presence of the CpG island methylator phenotype (CIMP) in NSCLC. On the basis of the methylation profile, CRBP1 and CDH13 methylation were good indicators of CIMP in NSCLC, and were correlated with a poorer prognosis in adenocarcinomas. Mutations in EGFR, HER-2, and KRAS were found to be present exclusively, whereas methylation tended to be present synchronously. A comparison of mutation and methylation demonstrated that the EGFR mutation had an inverse correlation with methylation of SPARC (secreted protein acidic and rich in cysteine), an extracellular Ca2+-binding matricellular glycoprotein associated with the regulation of cell adhesion and growth, and the p16INK4A gene. The findings of the current study suggest that adenocarcinoma cases with CIMP have a poorer prognosis than adenocarcinoma cases without CIMP, and the EGFR mutation was shown to have an inverse correlation with methylation of SPARC and the p16INK4A gene in NSCLC. Copyright 2006 American Cancer Society

Plasma epidermal growth factor receptor mutation testing with a chip-based digital PCR system in patients with advanced non-small cell lung cancer.

PubMed

Kasahara, Norimitsu; Kenmotsu, Hirotsugu; Serizawa, Masakuni; Umehara, Rina; Ono, Akira; Hisamatsu, Yasushi; Wakuda, Kazushige; Omori, Shota; Nakashima, Kazuhisa; Taira, Tetsuhiko; Naito, Tateaki; Murakami, Haruyasu; Koh, Yasuhiro; Mori, Keita; Endo, Masahiro; Nakajima, Takashi; Yamada, Masanobu; Kusuhara, Masatoshi; Takahashi, Toshiaki

2017-04-01

Epidermal growth factor receptor (EGFR) mutation testing is a companion diagnostic to determine eligibility for treatment with EGFR tyrosine kinase inhibitors (EGFR-TKIs) in non-small cell lung cancer (NSCLC). Recently, plasma-based EGFR testing by digital polymerase chain reaction (dPCR), which enables accurate quantification of target DNA, has shown promise as a minimally invasive diagnostic. Here, we aimed to evaluate the accuracy of a plasma-based EGFR mutation test developed using chip-based dPCR-based detection of 3 EGFR mutations (exon 19 deletions, L858R in exon 21, and T790M in exon 20). Forty-nine patients with NSCLC harboring EGFR-activating mutations were enrolled, and circulating free DNAs (cfDNAs) were extracted from the plasma of 21 and 28 patients before treatment and after progression following EGFR-TKI treatment, respectively. Using reference genomic DNA containing each mutation, the detection limit of each assay was determined to be 0.1%. The sensitivity and specificity of detecting exon 19 deletions and L858R mutations, calculated by comparing the mutation status in the corresponding tumors, were 70.6% and 93.3%, and 66.7% and 100%, respectively, showing similar results compared with previous studies. T790M was detected in 43% of 28 cfDNAs after progression with EGFR-TKI treatment, but in no cfDNAs before the start of the treatment. This chip-based dPCR assay can facilitate detection of EGFR mutations in cfDNA as a minimally invasive method in clinical settings. Copyright © 2017 Elsevier B.V. All rights reserved.

Primary and secondary dimer interfaces of the fibroblast growth factor receptor 3 transmembrane domain: characterization via multiscale molecular dynamics simulations.

PubMed

Reddy, Tyler; Manrique, Santiago; Buyan, Amanda; Hall, Benjamin A; Chetwynd, Alan; Sansom, Mark S P

2014-01-21

Receptor tyrosine kinases are single-pass membrane proteins that form dimers within the membrane. The interactions of their transmembrane domains (TMDs) play a key role in dimerization and signaling. Fibroblast growth factor receptor 3 (FGFR3) is of interest as a G380R mutation in its TMD is the underlying cause of ~99% of the cases of achondroplasia, the most common form of human dwarfism. The structural consequences of this mutation remain uncertain: the mutation shifts the position of the TMD relative to the lipid bilayer but does not alter the association free energy. We have combined coarse-grained and all-atom molecular dynamics simulations to study the dimerization of wild-type, heterodimer, and mutant FGFR3 TMDs. The simulations reveal that the helices pack together in the dimer to form a flexible interface. The primary packing mode is mediated by a Gx3G motif. There is also a secondary dimer interface that is more highly populated in heterodimer and mutant configurations that may feature in the molecular mechanism of pathology. Both coarse-grained and atomistic simulations reveal a significant shift of the G380R mutant dimer TMD relative to the bilayer to allow interactions of the arginine side chain with lipid headgroup phosphates.

Estrogen receptor (ESR1) mutation in bone metastases from breast cancer.

PubMed

Bartels, Stephan; Christgen, Matthias; Luft, Angelina; Persing, Sascha; Jödecke, Kai; Lehmann, Ulrich; Kreipe, Hans

2018-01-01

Activating mutations of estrogen receptor α gene (ESR1) in breast cancer can cause endocrine resistance of metastatic tumor cells. The skeleton belongs to the metastatic sides frequently affected by breast cancer. The prevalence of ESR1 mutation in bone metastasis and the corresponding phenotype are not known. In this study bone metastases from breast cancer (n=231) were analyzed for ESR1 mutation. In 27 patients (12%) (median age 73 years, range: 55-82 years) activating mutations of ESR1 were detected. The most frequent mutation was p.D538G (53%), no mutations in exon 4 (K303) or 7 (S463) were found. Lobular breast cancer was present in 52% of mutated cases (n=14) and in 49% of all samples (n=231), respectively. Mutated cancers constantly displayed strong estrogen receptor expression. Progesterone receptor was positive in 78% of the mutated cases (n=21). From 194 estrogen receptor-positive samples, 14% had ESR1 mutated. Except for one mutated case, no concurrent HER2 overexpression was noted. Metastatic breast cancer with activating mutations of ESR1 had a higher Ki67 labeling index than primary luminal cancers (median 30%, ranging from 5 to 60% with 85% of cases revealing ≥20% Ki67-positive cells). From those patients from whom information on endocrine therapy was available (n=7), two had received tamoxifen only, 4 tamoxifen followed by aromatase inhibitors and one patient had been treated with aromatase inhibitors only. We conclude that ESR1 mutation is associated with estrogen receptor expression and high proliferative activity and affects about 14% of estrogen receptor-positive bone metastases from breast cancer.

Effectors of epidermal growth factor receptor pathway: the genetic profiling ofKRAS, BRAF, PIK3CA, NRAS mutations in colorectal cancer characteristics and personalized medicine.

PubMed

Shen, Yinchen; Wang, Jianfei; Han, Xiaohong; Yang, Hongying; Wang, Shuai; Lin, Dongmei; Shi, Yuankai

2013-01-01

Mutations in KRAS oncogene are recognized biomarkers that predict lack of response to anti- epidermal growth factor receptor (EGFR) antibody therapies. However, some patients with KRAS wild-type tumors still do not respond, so other downstream mutations in BRAF, PIK3CA and NRAS should be investigated. Herein we used direct sequencing to analyze mutation status for 676 patients in KRAS (codons 12, 13 and 61), BRAF (exon 11 and exon 15), PIK3CA (exon 9 and exon 20) and NRAS (codons12, 13 and 61). Clinicopathological characteristics associations were analyzed together with overall survival (OS) of metastatic colorectal cancer patients (mCRC). We found 35.9% (242/674) tumors harbored a KRAS mutation, 6.96% (47/675) harbored a BRAF mutation, 9.9% (62/625) harbored a PIK3CA mutation and 4.19% (26/621) harbored a NRAS mutation. KRAS mutation coexisted with BRAF, PIK3CA and NRAS mutation, PIK3CA exon9 mutation appeared more frequently in KRAS mutant tumors (P = 0.027) while NRAS mutation almost existed in KRAS wild-types (P<0.001). Female patients and older group harbored a higher KRAS mutation (P = 0.018 and P = 0.031, respectively); BRAF (V600E) mutation showed a higher frequency in colon cancer and poor differentiation tumors (P = 0.020 and P = 0.030, respectively); proximal tumors appeared a higher PIK3CA mutation (P<0.001) and distant metastatic tumors shared a higher NRAS mutation (P = 0.010). However, in this study no significant result was found between OS and gene mutation in mCRC group. To our knowledge, the first large-scale retrospective study on comprehensive genetic profile which associated with anti-EGFR MoAbs treatment selection in East Asian CRC population, appeared a specific genotype distribution picture, and the results provided a better understanding between clinicopathological characteristics and gene mutations in CRC patients.

Two common low density lipoprotein receptor gene mutations cause familial hypercholesterolemia in Afrikaners.

PubMed

Leitersdorf, E; Van der Westhuyzen, D R; Coetzee, G A; Hobbs, H H

1989-09-01

Familial hypercholesterolemia (FH), an autosomal dominant disease caused by mutations in the LDL receptor gene, is five times more frequent in the Afrikaner population of South Africa than it is in the population of the United States and Europe. It has been proposed that the high frequency is due to a founder effect. In this paper, we characterized 24 mutant LDL receptor alleles from 12 Afrikaner individuals homozygous for FH. We identified two mutations that together makeup greater than 95% of the mutant LDL receptor genes represented in our sample. Both mutations were basepair substitutions that result in single-amino acid changes. Each mutation can be detected readily with the polymerase chain reaction and restriction analysis. The finding of two common LDL receptor mutations in the Afrikaner FH homozygotes predicts that these mutations will predominate in the Afrikaner population and that the high frequency of FH is due to a founder effect. The increased incidence of ischemic heart disease in the Afrikaner population may in part be due to the high frequency of these two mutations in the LDL receptor gene.

Two common low density lipoprotein receptor gene mutations cause familial hypercholesterolemia in Afrikaners.

PubMed Central

Leitersdorf, E; Van der Westhuyzen, D R; Coetzee, G A; Hobbs, H H

1989-01-01

Familial hypercholesterolemia (FH), an autosomal dominant disease caused by mutations in the LDL receptor gene, is five times more frequent in the Afrikaner population of South Africa than it is in the population of the United States and Europe. It has been proposed that the high frequency is due to a founder effect. In this paper, we characterized 24 mutant LDL receptor alleles from 12 Afrikaner individuals homozygous for FH. We identified two mutations that together makeup greater than 95% of the mutant LDL receptor genes represented in our sample. Both mutations were basepair substitutions that result in single-amino acid changes. Each mutation can be detected readily with the polymerase chain reaction and restriction analysis. The finding of two common LDL receptor mutations in the Afrikaner FH homozygotes predicts that these mutations will predominate in the Afrikaner population and that the high frequency of FH is due to a founder effect. The increased incidence of ischemic heart disease in the Afrikaner population may in part be due to the high frequency of these two mutations in the LDL receptor gene. Images PMID:2569482

Correlation between familial cancer history and epidermal growth factor receptor mutations in Taiwanese never smokers with non-small cell lung cancer: a case-control study.

PubMed

Cheng, Po-Chung; Cheng, Yun-Chung

2015-03-01

Lung cancer is a leading cause of cancer deaths in the world. Cigarette smoking remains a prominent risk factor, but lung cancer incidence has been increasing in never smokers. Genetic abnormalities including epidermal growth factor receptor (EGFR) mutations predominate in never smoking lung cancer patients. Furthermore, familial aggregations of patients with these mutations reflect heritable susceptibility to lung cancer. The correlation between familial cancer history and EGFR mutations in never smokers with lung cancer requires investigation. This was a retrospective case-control study that evaluated the prevalence of EGFR mutations in lung cancer patients with familial cancer history. Never smokers with lung cancer treated at a hospital in Taiwan between April 2012 and May 2014 were evaluated. Inclusion criteria were never smokers with non-small cell lung cancer (NSCLC). Exclusion criteria involved patients without records of familial cancer history or tumor genotype. This study included 246 never smokers with lung cancer. The study population mainly involved never smoking women with a mean age of 60 years, and the predominant tumor histology was adenocarcinoma. Lung cancer patients with familial cancer history had an increased prevalence of EGFR mutations compared to patients without family history [odds ratio (OR): 5.9; 95% confidence interval (CI): 3.3-10.6; P<0.001]. Specifically, 57 out of 85 cancer patients (67%) with familial cancer history had these mutations, while 41 out of 161 patients (25%) without family history harbored mutations. Subgroup analysis also revealed that patients with familial lung cancer history had stronger association with EGFR mutations (OR: 7.5; 95% CI: 3.4-16.3; P<0.001) compared to patients with family history of non-pulmonary cancers (OR: 5.0; 95% CI: 2.5-10.0; P<0.001). The study demonstrated an increased prevalence of EGFR mutations in Taiwanese never smoking lung cancer patients with familial cancer history. Moreover, a sizable proportion of never smoking cancer patients harbored these mutations. These observations have implications for the treatment of lung cancer in never smokers.

Clinical and pathological characterization of HER2 mutations in human breast cancer: a systematic review of the literature.

PubMed

Petrelli, Fausto; Tomasello, Gianluca; Barni, Sandro; Lonati, Veronica; Passalacqua, Rodolfo; Ghidini, Michele

2017-11-01

HER2 gene is a member of the epidermal growth factor receptor (EGFR) family. Across different malignancies, aberrations of HER2 gene commonly correspond to gain-of-function alterations leading to increased receptor signaling. We have reviewed the literature currently available on HER2 mutations in human breast cancer (BC) evaluating type and frequency of such mutations. The primary objective was to determine the frequency and the number of patients with HER2-mut in the series analyzed. The secondary objectives were to assess characteristics of mutated cases (ER and HER2 status and stage of disease, type of mutations, and finally the clinical outcome if reported). We retrieved 31 published papers, and the pooled rate of HER2 mutations across 12,905 BC patients was calculated. Overall, the frequency of HER2 mutations was 2.7% with most involving the intracellular domain. About 4% of patients were finally mutated. The predictive role was not described. Only 30% of these patients were simultaneously HER2 positive and 63% were ER positive. We have found that the prevalence of HER2 mutations is about 3%. These genic alterations are independently associated with HER2 amplification status, occurring in both ER-positive/HER2-negative diseases or HER2-enriched cancers. Ongoing trials are investigating small molecules tyrosine kinase inhibitors in patients harboring these mutations.

Functional Analyses of a Novel CITED2 Nonsynonymous Mutation in Chinese Tibetan Patients with Congenital Heart Disease.

PubMed

Liu, Shiming; Su, Zhaobing; Tan, Sainan; Ni, Bin; Pan, Hong; Liu, Beihong; Wang, Jing; Xiao, Jianmin; Chen, Qiuhong

2017-08-01

CITED2 gene is an important cardiac transcription factor that plays a fundamental role in the formation and development of embryonic cardiovascular. Previous studies have showed that knock-out of CITED2 in mice might result in various cardiac malformations. However, the mechanisms of CITED2 mutation on congenital heart disease (CHD) in Chinese Tibetan population are still poorly understood. In the present study, 187 unrelated Tibetan patients with CHD and 200 unrelated Tibetan healthy controls were screened for variants in the CITED2 gene; we subsequently identified one potential disease-causing mutation p.G143A in a 6-year-old girl with PDA and functional analyses of the mutation were carried out. Our study showed that the novel mutation of CITED2 significantly enhanced the expression activity of vascular endothelial growth factor (VEGF) under the role of co-receptor hypoxia inducible factor 1-aipha (HIF-1A), which is closely related with embryonic cardiac development. As a result, CITED2 gene mutation may play a significant role in the development of pediatric congenital heart disease.

FH Afrikaner-3 LDL receptor mutation results in defective LDL receptors and causes a mild form of familial hypercholesterolemia.

PubMed

Graadt van Roggen, J F; van der Westhuyzen, D R; Coetzee, G A; Marais, A D; Steyn, K; Langenhoven, E; Kotze, M J

1995-06-01

Three founder-related gene mutations (FH Afrikaner-1, -2, and -3) that affect the LDL receptor are responsible for 90% of the familial hypercholesterolemia (FH) in South African Afrikaners. Patients heterozygous for the FH Afrikaner-1 (FH1) mutation, which results in receptors having approximately 20% of normal receptor activity, have significantly lower plasma cholesterol levels and milder clinical symptoms than heterozygotes with the FH Afrikaner-2 mutation, which completely abolishes LDL receptor activity. In this study we re-created the FH3 mutation (Asp154-->Asn) in exon 4 by site-directed mutagenesis and analyzed the expression of the mutant receptors in Chinese hamster ovary cells. The mutation resulted in the formation of LDL receptors that are markedly defective in their ability to bind LDL, whereas binding of apoE-containing beta-VLDL is less affected. The mutant receptors are poorly expressed on the cell surface as a result of significant degradation of receptor precursors. The plasma cholesterol levels of 31 FH3 heterozygotes were similar to FH1 heterozygotes but significantly lower than FH2 heterozygotes. The FH1 and FH3 heterozygotes also tended to be less severely affected clinically (by coronary heart disease and xanthomata) than FH2 patients. This study demonstrates that mutational heterogeneity in the LDL receptor gene influences the phenotypic expression of heterozygous FH and that severity of expression correlates with the activity of the LDL receptor measured in vitro. The results further indicate that knowledge of the specific mutation underlying FH in heterozygotes is valuable in determining the potential risk of premature atherosclerosis and should influence the clinical management of FH patients.

Hyperfunctioning thyroid nodules in toxic multinodular goiter share activating thyrotropin receptor mutations with solitary toxic adenoma.

PubMed

Tonacchera, M; Chiovato, L; Pinchera, A; Agretti, P; Fiore, E; Cetani, F; Rocchi, R; Viacava, P; Miccoli, P; Vitti, P

1998-02-01

Toxic multinodular goiter is a cause of nonautoimmune hyperthyroidism and is believed to differ in its nature and pathogenesis from toxic adenoma. Gain-of-function mutations of the TSH receptor gene have been identified as a cause of toxic adenoma. The pathogenesis at the molecular level of hyperfunctioning nodules in toxic multinodular goiter has yet not been reported. Six patients with a single hot nodule within a multinodular goiter and 11 patients with toxic thyroid adenoma were enrolled in our study. At histology five hyperfunctioning nodules in multinodular goiters showed the features of adenomas, and one was identified as a hyperplastic nodule. The entire exon 10 of the TSH receptor gene was directly sequenced after PCR amplification from genomic DNA obtained from surgical specimens. Functional studies of mutated receptors were performed in COS-7 cells. Five out of 6 (83%) hyperfunctioning nodules within toxic multinodular goiters harbored a TSH receptor mutation. A TSH receptor mutation was also evident in the hyperfunctioning nodule that at histology had the features of noncapsulated hyperplastic nodule. Among toxic adenomas, 8 out of 11 (72%) nodules harbored a TSH receptor mutation. All the mutations were heterozygotic and somatic. Nonfunctioning nodules, whether adenomas or hyperplastic nodules present in association with hyperfunctioning nodules in the same multinodular goiters, had no TSH receptor mutation. All the mutations identified had constitutive activity as assessed by cAMP production after expression in COS-7 cells. Hyperfunctioning thyroid nodules in multinodular goiters recognize the same pathogenetic event (TSH receptor mutation) as toxic adenoma. Other mechanisms are implicated in the growth of nonfunctioning thyroid nodules coexistent in the same gland.

In Vitro Killing of Colorectal Carcinoma Cells by Autologous Activated NK Cells is Boosted by Anti-Epidermal Growth Factor Receptor-induced ADCC Regardless of RAS Mutation Status.

PubMed

Turin, Ilaria; Delfanti, Sara; Ferulli, Federica; Brugnatelli, Silvia; Tanzi, Matteo; Maestri, Marcello; Cobianchi, Lorenzo; Lisini, Daniela; Luinetti, Ombretta; Paulli, Marco; Perotti, Cesare; Todisco, Elisabetta; Pedrazzoli, Paolo; Montagna, Daniela

2018-05-01

Treatment of advanced metastatic colorectal cancer (mCRC) patients is associated with a poor prognosis and significant morbidity. Moreover, targeted therapies such as anti-epidermal growth factor receptor (EGFR) have no effect in metastatic patients with tumors harboring a mutation in the RAS gene. The failure of conventional treatment to improve outcomes in mCRC patients has prompted the development of adoptive immunotherapy approaches including natural killer (NK)-based therapies. In this study, after confirmation that patients' NK cells were not impaired in their cytotoxic activity, evaluated against long-term tumor cell lines, we evaluated their interactions with autologous mCRC cells. Molecular and phenotypical evaluation of mCRC cells, expanded in vitro from liver metastasis, showed that they expressed high levels of polio virus receptor and Nectin-2, whereas UL16-binding proteins were less expressed in all tumor samples evaluated. Two different patterns of MICA/B and HLA class I expression on the membrane of mCRC were documented; approximately half of mCRC patients expressed high levels of these molecules on the membrane surface, whereas, in the remaining, very low levels were documented. Resting NK cells were unable to display sizeable levels of cytotoxic activity against mCRC cells, whereas their cytotoxic activity was enhanced after overnight or 5-day incubation with IL-2 or IL-15. The susceptibility of NK-mediated mCRC lysis was further significantly enhanced after coating with cetuximab, irrespective of their RAS mutation and HLA class I expression. These data open perspectives for combined NK-based immunotherapy with anti-epidermal growth factor receptor antibodies in a cohort of mCRC patients with a poor prognosis refractory to conventional therapies.

The androgen receptor gene mutations database.

PubMed

Patterson, M N; Hughes, I A; Gottlieb, B; Pinsky, L

1994-09-01

The androgen receptor gene mutations database is a comprehensive listing of mutations published in journals and meetings proceedings. The majority of mutations are point mutations identified in patients with androgen insensitivity syndrome. Information is included regarding the phenotype, the nature and location of the mutations, as well as the effects of the mutations on the androgen binding activity of the receptor. The current version of the database contains 149 entries, of which 114 are unique mutations. The database is available from EMBL (NetServ@EMBL-Heidelberg.DE) or as a Macintosh Filemaker file (mc33001@musica.mcgill.ca).

Increased expression of pro-angiogenic factors and vascularization in thyroid hyperfunctioning adenomas with and without TSH receptor activating mutations.

PubMed

Celano, Marilena; Sponziello, Marialuisa; Tallini, Giovanni; Maggisano, Valentina; Bruno, Rocco; Dima, Mariavittoria; Di Oto, Enrico; Redler, Adriano; Durante, Cosimo; Sacco, Rosario; Filetti, Sebastiano; Russo, Diego

2013-02-01

Autonomously functioning thyroid nodules (AFTN) are known to receive an increased blood influx necessary to sustain their high rate of growth and hormone production. Here, we investigated the expression of hematic and lymphatic vases in a series of 20 AFTN compared with the contralateral non-tumor tissues of the same patients, and the transcript levels of proteins involved in the control of vascular proliferation, including the vascular endothelial growth factor (VEGF) and platelet-derived growth factors (PDGF) and their receptors and the endothelial nitric oxide synthase (eNOS). In parallel, the expression of the differentiation markers sodium/iodide symporter (NIS), thyroperoxidase (TPO), thyroglobulin (Tg), and TSH receptor (TSHR) was also investigated. The data were further analyzed comparing subgroups of tumors with or without mutations in the TSHR gene. Analysis by means of CD31 and D2-40 immunostaining showed in AFTN an increased number of hematic, but not lymphatic, vessels in parallel with an enhanced proliferation rate shown by increased Ki67 staining. Quantitative RT-PCR analysis revealed an increase of VEGF, VEGFR1 and 2, PDGF-A, PDGF-B, and eNOS expression in tumor versus normal tissues. Also, higher transcript levels of NIS, TPO, and Tg were detected. Comparison of the two subgroups of samples revealed only few differences in the expression of the genes examined. In conclusion, these data demonstrate an increased expression of angiogenesis-related factors associated with an enhanced proliferation of hematic, but not lymphatic, vessels in AFTNs. In this context, the presence of TSHR mutations may only slightly influence the expression of pro-angiogenic growth factors.

Orbital metastasis secondary to pulmonary adenocarcinoma treated with gefitinib: a case report.

PubMed

Koma, Yasuko; Goto, Keiko; Yoshida, Chihiro; Kimura, Kengo; Matsumoto, Yusuke; Koyama, Midori; Nakashima, Nariyasu; Masuya, Daiki; Matsuoka, Hirofumi; Yoshimatsu, Harukazu; Azumi, Atsushi; Suzuki, Yujiro

2012-10-18

Orbital metastases of lung cancer are rare. However, because the number of patients diagnosed with lung cancer is increasing, the probability that a physician will see a patient with an orbital metastasis is also increasing. Unfortunately, the clinical course and response of these patients to cytotoxic chemotherapy are generally poor and keeping a patient's quality of vision is difficult. In recent years, gefitinib, an epidermal growth factor receptor tyrosine kinase inhibitor, has brightened the outlook for patients with advanced non-small cell lung cancer, especially for those who carry epidermal growth factor receptor-activating mutations. A 62-year-old Japanese man presented with swelling of the eyelid margin and ptosis of his right eye. A physical examination revealed double vision in his right eye and an alteration in elevator muscle mobility. A magnetic resonance image demonstrated a right intra-orbital mass (18 × 16mm). Screening examinations were carried out because this mass was suspected to be a metastasis from another organ. Chest computed tomography revealed a 42 × 37mm mass shadow on the left side of the hilum with mediastinal lymph node metastases. Adenocarcinoma with an epidermal growth factor receptor gene mutation (exon 19 deletion L747-E749; A750P) was detected in a transbronchial biopsy specimen; the patient was diagnosed with stage IV (T2N2M1) non-small cell lung cancer.Gefitinib (250mg/day) was chosen as first-line chemotherapy because there was no pre-existing interstitial shadow. After two months of treatment, the patient's right eye opened completely and follow-up magnetic resonance imaging revealed a marked reduction of the intra-orbital mass to 14 × 13mm. Three months after treatment initiation, a follow-up computed tomography showed a marked reduction in the size of the primary lesion to 23 × 20mm. The patient is continuing gefitinib treatment without any adverse effects noted on computed tomography, physical, or laboratory examination. We report the case of a patient with an orbital non-small cell lung cancer metastasis with epidermal growth factor receptor-activating mutations. This metastasis, as well as the primary lesion, showed a marked response to the molecular targeting drug gefitinib, and the patient's vision was kept without an invasive procedure. Gefitinib may be a good first choice for patients with orbital non-small cell lung cancer metastasis harboring epidermal growth factor receptor-activating mutations.

Compound deficiencies in multiple fibroblast growth factor signalling components differentially impact the murine gonadotrophin-releasing hormone system.

PubMed

Chung, W C J; Matthews, T A; Tata, B K; Tsai, P-S

2010-08-01

Gonadotrophin-releasing hormone (GnRH) neurones control the onset and maintenance of fertility. Aberrant development of the GnRH system underlies infertility in Kallmann syndrome [KS; idiopathic hypogonadotropic hypogonadism (IHH) and anosmia]. Some KS patients harbour mutations in the fibroblast growth factor receptor 1 (Fgfr1) and Fgf8 genes. The biological significance of these two genes in GnRH neuronal development was corroborated by the observation that GnRH neurones were severely reduced in newborn transgenic mice deficient in either gene. In the present study, we hypothesised that the compound deficiency of Fgf8 and its cognate receptors, Fgfr1 and Fgfr3, may lead to more deleterious effects on the GnRH system, thereby resulting in a more severe reproductive phenotype in patients harbouring these mutations. This hypothesis was tested by counting the number of GnRH neurones in adult transgenic mice with digenic heterozygous mutations in Fgfr1/Fgf8, Fgfr3/Fgf8 or Fgfr1/Fgfr3. Monogenic heterozygous mutations in Fgfr1, Fgf8 or Fgfr3 caused a 30-50% decrease in the total number of GnRH neurones. Interestingly, mice with digenic mutations in Fgfr1/Fgf8 showed a greater decrease in GnRH neurones compared to mice with a heterozygous defect in the Fgfr1 or Fgf8 alone. This compounding effect was not detected in mice with digenic heterozygous mutations in Fgfr3/Fgf8 or Fgfr1/Fgfr3. These results support the hypothesis that IHH/KS patients with digenic mutations in Fgfr1/Fgf8 may have a further reduction in the GnRH neuronal population compared to patients harbouring monogenic haploid mutations in Fgfr1 or Fgf8. Because only Fgfr1/Fgf8 compound deficiency leads to greater GnRH system defect, this also suggests that these fibroblast growth factor signalling components interact in a highly specific fashion to support GnRH neuronal development.

Clinical features and treatment outcome of non-small cell lung cancer (NSCLC) patients with uncommon or complex epidermal growth factor receptor (EGFR) mutations

PubMed Central

Fassan, Matteo; Indraccolo, Stefano; Calabrese, Fiorella; Favaretto, Adolfo; Bonanno, Laura; Polo, Valentina; Zago, Giulia; Lunardi, Francesca; Attili, Ilaria; Pavan, Alberto; Rugge, Massimo; Guarneri, Valentina; Conte, PierFranco; Pasello, Giulia

2017-01-01

Introduction Tyrosine-kinase inhibitors (TKIs) represent the best treatment for advanced non-small cell lung cancer (NSCLC) with common exon 19 deletion or exon 21 epidermal growth factor receptor mutation (EGFRm). This is an observational study investigating epidemiology, clinical features and treatment outcome of NSCLC cases harbouring rare/complex EGFRm. Results Among 764 non-squamous NSCLC cases with known EGFRm status, 26(3.4%) harboured rare/complex EGFRm. Patients receiving first-line TKIs (N = 17) achieved median Progression Free Survival (PFS) and Overall Survival (OS) of 53 (IC 95%, 2–105) and 84 (CI 95%, 27–141) weeks respectively, without significant covariate impact. Response Rate and Disease Control Rate (DCR) were 47% and 65%, respectively. Uncommon exon 19 mutations achieved longer OS and PFS and higher DCR compared with exon 18 and 20 mutations. No additional gene mutation was discovered by MassARRAY analysis. TKIs were globally well tolerated. Materials and methods A retrospective review of advanced non-squamous NSCLC harbouring rare/complex EGFRm referred to our Center between 2010 and 2015 was performed. Additional molecular pathways disregulation was explored in selected cases, through MassARRAY analysis. Conclusions Peculiar clinical features and lower TKIs sensitivity of uncommon/complex compared with common EGFRm were shown. Exon 19 EGFRm achieved the best TKIs treatment outcome, while the optimal treatment of exon 18 and 20 mutations should be further clarified. PMID:28427238

Infrequent detectable somatic mutations of the RET and glial cell line-derived neurotrophic factor (GDNF) genes in human pituitary adenomas.

PubMed

Yoshimoto, K; Tanaka, C; Moritani, M; Shimizu, E; Yamaoka, T; Yamada, S; Sano, T; Itakura, M

1999-02-01

RET is a receptor tyrosine kinase expressed in neuroendocrine cells and tumors. RET is activated by a ligand complex comprising glial cell line-derived neurotrophic factor (GDNF) and GDNF receptor-alpha (GDNFR-alpha). Activating mutations of the RET proto-oncogene were found in multiple endocrine neoplasia (MEN) 2 and in sporadic medullary thyroid carcinoma and pheochromocytoma of neuroendocrine origin. Mutations of the RET proto-oncogene and the glial cell line-derived neurotrophic factor (GDNF) gene were examined in human pituitary tumors. No mutations of the RET proto-oncogene including the cysteine-rich region or codon 768 and 918 in the tyrosine kinase domain were detected in 172 human pituitary adenomas either by polymerase chain reaction (PCR)-single strand conformation polymorphism (SSCP) or by PCR-restriction fragment length polymorphism (RFLP). Further, somatic mutations of the GDNF gene in 33 human pituitary adenomas were not detected by PCR-SSCP. One polymorphism of the GDNF gene at codon 145 of TGC or TGT was observed in a prolactinoma. The RET proto-oncogene message was detected in a normal human pituitary gland or 4 of 4 human pituitary adenomas with reverse transcription (RT)-PCR, and in rodent pituitary tumor cell lines with Western blotting. The expression of GDNF gene was detected in 1 of 4 human somatotroph adenomas, 1 of 2 corticotroph adenomas, and 2 of 6 rodent pituitary tumor cell lines with RT-PCR. Based on these, it is concluded that somatic mutations of the RET proto-oncogene or the GDNF gene do not appear to play a major role in the pituitary tumorigenesis in examined tumors.

Impact of active smoking on survival of patients with metastatic lung adenocarcinoma harboring an epidermal growth factor receptor (EGFR) mutation.

PubMed

Erdogan, Bulent; Kodaz, Hilmi; Karabulut, Senem; Cinkaya, Ahmet; Tozkir, Hilmi; Tanriverdi, Ozgur; Cabuk, Devrim; Hacioglu, Muhammed Bekir; Turkmen, Esma; Hacibekiroglu, Ilhan; Uzunoglu, Sernaz; Cicin, Irfan

2016-11-10

Lung cancer in smokers and non-smokers demonstrates distinct genetic profiles, and cigarette smoking affects epidermal growth factor receptor (EGFR) function and causes secondary EGFR tyrosine kinase resistance. We evaluated the effect of active smoking in patients with metastatic lung adenocarcinoma. A total of 132 metastatic lung adenocarcinoma patients, diagnosed between 2008 and 2013, with known EGFR mutation status, were evaluated retrospectively. Among these patients, 40 had an activating EGFR mutation. Patients who continued smoking during the treatment were defined as active smokers. Former smokers and never smokers were together defined as non-smokers. The outcomes of the treatment in relation to the EGFR mutation and smoking status were evaluated. The median follow-up time was 10.5 months. The overall response rate for the first-line therapy was significantly higher among the EGFR-mutant patients (p = 0.01), however, smoking status had no impact on the response rate (p = 0.1). The EGFR-mutant active smokers progressed earlier than the non-smokers (p < 0.01). The overall survival (OS) of the non-smokers and patients treated with erlotinib was significantly longer (p = 0.02 and p = 0.01, respectively). Smoking status did not affect the OS in EGFR wild type tumors (p = 0.49) but EGFR-mutant non-smokers had a longer OS than the active smokers (p = 0.01).The active smokers treated with erlotinib had poorer survival than the non-smokers (p = 0.03). Multivariate analysis of EGFR-mutant patients showed that erlotinib treatment at any line and non-smoking were independent prognostic factors for the OS (p = 0.04 and p = 0.01, respectively). Smoking during treatment is a negative prognostic factor in metastatic lung adenocarcinoma with an EGFR mutation.

Epidermal growth factor receptor signaling pathway is frequently altered in ampullary carcinoma at protein and genetic levels.

PubMed

Mikhitarian, Kaidi; Pollen, Maressa; Zhao, Zhiguo; Shyr, Yu; Merchant, Nipun B; Parikh, Alexander; Revetta, Frank; Washington, M Kay; Vnencak-Jones, Cindy; Shi, Chanjuan

2014-05-01

Our objective was to explore alteration of the epidermal growth factor receptor (EGFR) signaling pathway in ampullary carcinoma. Immunohistochemical studies were employed to evaluate expression of amphiregulin as well as expression and activation of EGFR. A lab-developed assay was used to identify mutations in the EGFR pathway genes, including KRAS, BRAF, PIK3CA, PTEN, and AKT1. A total of 52 ampullary carcinomas were identified, including 25 intestinal-type and 24 pancreatobiliary-type tumors, with the intestinal type being associated with a younger age at diagnosis (P=0.03) and a better prognosis (P<0.01). Expression of amphiregulin correlated with better differentiation (P<0.01), but no difference was observed between two major histologic types. Expression and activation of EGFR was more commonly seen in the pancreatobiliary type (P<0.01). Mutations were detected in 50% of the pancreatobiliary type and 60% of the intestinal type. KRAS was the most common gene mutated in the pancreatobiliary type (42%) as well as the intestinal type (52%). Other mutations detected included PIK3CA, SMAD4 and BRAF. KRAS mutations at codons 12 and 13 did not adversely affect overall survival. In conclusion, EGFR expression and activation were different between intestinal- and pancreatobiliary-type ampullary carcinoma. KRAS mutation was common in both histologic types; however, the incidence appeared to be lower in the pancreatobiliary type compared with its pancreatic counterpart, pancreatic ductal adenocarcinoma. Mutational analysis of the EGFR pathway genes may provide important insights into personalized treatment for patients with ampullary carcinoma.

Mutations in the Kinase Domain of the HER2/ERBB2 Gene Identified in a Wide Variety of Human Cancers.

PubMed

Wen, Wenhsiang; Chen, Wangjuh Sting; Xiao, Nick; Bender, Ryan; Ghazalpour, Anatole; Tan, Zheng; Swensen, Jeffrey; Millis, Sherri Z; Basu, Gargi; Gatalica, Zoran; Press, Michael F

2015-09-01

The HER2 (official name ERBB2) gene encodes a membrane receptor in the epidermal growth factor receptor family amplified and overexpressed in adenocarcinoma. Activating mutations also occur in several cancers. We report mutation analyses of the HER2 kinase domain in 7497 histologically diverse cancers. Forty-five genes, including the kinase domain of HER2 with HER2 IHC and dual in situ hybridization, were analyzed in tumors from 7497 patients with cancer, including 850 breast, 770 colorectal, 910 non-small cell lung, 823 uterine or cervical, 1372 ovarian, and 297 pancreatic cancers, as well as 323 melanomas and 2152 other solid tumors. Sixty-nine HER2 kinase domain mutations were identified in tumors from 68 patients (approximately 1% of all cases, ranging from absent in sarcomas to 4% in urothelial cancers), which included previously published activating mutations and 13 novel mutations. Fourteen cases with coexisting HER2 mutation and amplification and/or overexpression were identified. Fifty-two of 68 patients had additional mutations in other analyzed genes, whereas 16 patients (23%) had HER2 mutations identified as the sole driver mutation. HER2 mutations coexisted with HER2 gene amplification and overexpression and with mutations in other functionally important genes. HER2 mutations were identified as the only driver mutation in a significant proportion of solid cancers. Evaluation of anti-HER2 therapies in nonamplified, HER2-mutated cancers is warranted. Copyright © 2015 American Society for Investigative Pathology and the Association for Molecular Pathology. Published by Elsevier Inc. All rights reserved.

Fibroblast growth factor receptor signaling crosstalk in skeletogenesis.

PubMed

Miraoui, Hichem; Marie, Pierre J

2010-11-02

Fibroblast growth factors (FGFs) play important roles in the control of embryonic and postnatal skeletal development by activating signaling through FGF receptors (FGFRs). Germline gain-of-function mutations in FGFR constitutively activate FGFR signaling, causing chondrocyte and osteoblast dysfunctions that result in skeletal dysplasias. Crosstalk between the FGFR pathway and other signaling cascades controls skeletal precursor cell differentiation. Genetic analyses revealed that the interplay of WNT and FGFR1 determines the fate and differentiation of mesenchymal stem cells during mouse craniofacial skeletogenesis. Additionally, interactions between FGFR signaling and other receptor tyrosine kinase networks, such as those mediated by the epidermal growth factor receptor and platelet-derived growth factor receptor α, were associated with excessive osteoblast differentiation and bone formation in the human skeletal dysplasia called craniosynostosis, which is a disorder of skull development. We review the roles of FGFR signaling and its crosstalk with other pathways in controlling skeletal cell fate and discuss how this crosstalk could be pharmacologically targeted to correct the abnormal cell phenotype in skeletal dysplasias caused by aberrant FGFR signaling.

Hyperekplexia mutation R271L of alpha1 glycine receptors potentiates allosteric interactions of nortropeines, propofol and glycine with [3H]strychnine binding.

PubMed

Maksay, Gábor; Bíró, Tímea; Laube, Bodo; Nemes, Péter

2008-01-01

Human alpha1 and hyperekplexia mutant alpha1(R271L) glycine receptors (GlyRs) were transiently expressed in human embryonic kidney 293 cells for [3H]strychnine binding. Binding parameters were determined using a ternary allosteric model. The hyperekplexia mutation increased the positive cooperativity of 0.3 mM propofol and glycine binding by about six times: the cooperativity factor beta was 0.26 for alpha1 GlyRs and 0.04 for alpha1(R271L) GlyRs. Thus, propofol restored the potency of glycine impaired by the mutation. Five nortropeines, i.e. substituted benzoates of nortropine and a new compound, nortropisetron were prepared and also examined on [3H]strychnine binding. They showed nanomolar displacing potencies amplified by the hyperekplexia mutation. The affinity of nor-O-zatosetron (2.6 nM) is one of the highest reported for GlyRs. This binding test offers an in vitro method to evaluate agents against neurological disorders associated with inherited mutations of GlyRs.

Mastocytosis in mice expressing human Kit receptor with the activating Asp816Val mutation

PubMed Central

Zappulla, Jacques P.; Dubreuil, Patrice; Desbois, Sabine; Létard, Sébastien; Hamouda, Nadine Ben; Daëron, Marc; Delsol, Georges; Arock, Michel; Liblau, Roland S.

2005-01-01

Mastocytosis is a rare neoplastic disease characterized by a pathologic accumulation of tissue mast cells (MCs). Mastocytosis is often associated with a somatic point mutation in the Kit protooncogene leading to an Asp/Val substitution at position 816 in the kinase domain of this receptor. The contribution of this mutation to mastocytosis development remains unclear. In addition, the clinical heterogeneity presented by mastocytosis patients carrying the same mutation is unexplained. We report that a disease with striking similarities to human mastocytosis develops spontaneously in transgenic mice expressing the human Asp816Val mutant Kit protooncogene specifically in MCs. This disease is characterized by clinical signs ranging from a localized and indolent MC hyperplasia to an invasive MC tumor. In addition, bone marrow–derived MCs from transgenic animals can be maintained in culture for >24 mo and acquire growth factor independency for proliferation. These results demonstrate a causal link in vivo between the Asp816Val Kit mutation and MC neoplasia and suggest a basis for the clinical heterogeneity of human mastocytosis. PMID:16352739

Flipped script for gefitinib: A reapproved tyrosine kinase inhibitor for first-line treatment of epidermal growth factor receptor mutation positive metastatic nonsmall cell lung cancer.

PubMed

Bogdanowicz, Brian S; Hoch, Matthew A; Hartranft, Megan E

2017-04-01

Purpose The approval history, pharmacology, pharmacokinetics, clinical trials, efficacy, dosing recommendations, drug interactions, safety, place in therapy, and economic considerations of gefitinib are reviewed. Summary Lung cancer is one of the most commonly diagnosed cancers and is the leading cause of cancer death. Platinum-based chemotherapy and tyrosine kinase inhibitors, such as erlotinib and afatinib, are recommended therapies for nonsmall cell lung cancer. The European Medicines Association based their approval of gefitinib on the randomized, multicenter Iressa Pan-Asia Study (IPASS, NCT00322452) and a single-arm study showing effectiveness in Caucasians (IFUM, NCT01203917). Both studies were recently referenced by the United States Food & Drug Administration to reapprove gefitinib for the first-line treatment of advanced nonsmall cell lung cancer with epidermal growth factor receptor exon 19 deletions or exon 21 substitution. Diarrhea, acneiform rash, and interstitial lung disease are known side effects of gefitinib. Conclusion Use of gefitinib for the first-line therapy of metastatic nonsmall cell lung cancer with epidermal growth factor receptor exon 19 deletions (residues 747-750) or exon 21 substitution mutation (L858R) is well-documented and supported.

Recurrent abdominal pain as the presentation of tumor necrosis factor receptor-associated periodic syndrome (TRAPS) in an Asian girl: a case report and review of the literature.

PubMed

Chen, Yun-Ju; Yu, Hsin-Hui; Yang, Yao-Hsu; Lau, Yu-Lung; Lee, Wen-I; Chiang, Bor-Luen

2014-12-01

Tumor necrosis factor receptor-associated periodic syndrome (TRAPS) is characterized by periodic fever, cutaneous rash, conjunctivitis, lymphadenopathy, abdominal pain, myalgia, and arthralgia. It is a rare autosomal dominant disease and strongly associated with heterozygous mutations in the tumor necrosis factor (TNF) receptor super family 1A (TNFRSF1A) gene. It is believed to be more common in Western countries than in Asian countries. Here, we present the case of a 14-year-old girl with periodic fever and abdominal pain with elevation of inflammatory markers for 2 years. After extensive work-up of infectious etiology with negative results, the diagnosis of TRAPS was made although no gene mutations were identified in the TNFRSF1A gene, MVK gene, and NALP3/CIAS1 gene. She had partial clinical response to corticosteroids and immunomodulatory agents. However, the treatment response to TNF-α inhibitor etanercept was dramatic. She has remained symptom free under regular weekly to biweekly etanercept treatment for 2 years. We also reviewed the related literature and summarized the data of 10 Asian cases of TRAPS. Copyright © 2012. Published by Elsevier B.V.

Genetic screening of Wnt signaling factors in advanced retinopathy of prematurity

PubMed Central

Takahashi, Hiroshi; Orimo, Hideo; Hiraoka, Miina; Ogata, Tsutomu; Azuma, Noriyuki

2010-01-01

Purpose To evaluate the possibility of genetic involvement in retinopathy of prematurity (ROP). Although ROP is most often associated with low birthweight and low gestational age, these factors do not necessarily predict the severity of ROP. The possible involvement of other factors, including genetic variants, has been considered. Familial exudative vitreoretinopathy (FEVR) is a hereditary vitreoretinal disorder with clinical manifestations similar to those of ROP. Three genes involving the wingless/int1 (Wnt) receptor signaling pathway—FZD4 for frizzled 4, LRP5 for low-density lipoprotein receptor-related protein 5, and ND for Norrie disease protein—are associated with the development of FEVR. Methods In the present study, 17 Japanese patients with advanced ROP were screened for these three candidate genes of FEVR. Genomic DNA from each patient was subjected to PCR and direct sequencing of the ND, FZD4, and LRP5 genes. Results One patient had a heterozygous mutation in the 5′ untranslated region of the ND gene. Another had a leucine insertion in the signal peptide of LRP5. None showed any mutation in FZD4. Conclusions These findings suggest that genetic changes in the Wnt receptor signaling pathway associate to the development of advanced ROP. PMID:21151595

Binge eating as a major phenotype of melanocortin 4 receptor gene mutations.

PubMed

Branson, Ruth; Potoczna, Natascha; Kral, John G; Lentes, Klaus-Ulrich; Hoehe, Margret R; Horber, Fritz F

2003-03-20

Obesity, a multifactorial disease caused by the interaction of genetic factors with the environment, is largely polygenic. A few mutations in these genes, such as in the leptin receptor (LEPR) gene and melanocortin 4 receptor (MC4R) gene, have been identified as causes of monogenic obesity. We sequenced the complete MC4R coding region, the region of the proopiomelanocortin gene (POMC) encoding the alpha melanocyte-stimulating hormone, and the leptin-binding domain of LEPR in 469 severely obese white subjects (370 women and 99 men; mean [+/-SE] age, 41.0+/-0.5 years; body-mass index [the weight in kilograms divided by the square of the height in meters], 44.1+/-2.0). Fifteen women and 10 men without a history of dieting or a family history of obesity served as normal-weight controls (age, 47.7+/-2.0 years; body-mass index, 21.6+/-0.4). Detailed phenotypic data, including information on body fat, resting energy expenditure, diet-induced thermogenesis, serum concentrations of leptin, and eating behavior, were collected. Twenty-four obese subjects (5.1 percent) and one control subject (4 percent) had MC4R mutations, including five novel variants. Twenty of the 24 obese subjects with an MC4R mutation were matched for age, sex, and body-mass index with 120 of the 445 obese subjects without an MC4R mutation. All mutation carriers reported binge eating, as compared with 14.2 percent of obese subjects without mutations (P<0.001) and 0 percent of the normal-weight subjects without mutations. The prevalence of binge eating was similar among carriers of mutations in the leptin-binding domain of LEPR and noncarriers. No mutations were found in the region of POMC encoding alpha melanocyte-stimulating hormone. Binge eating is a major phenotypic characteristic of subjects with a mutation in MC4R, a candidate gene for the control of eating behavior. Copyright 2003 Massachusetts Medical Society

Osimertinib in patients with advanced epidermal growth factor receptor T790M mutation-positive non-small cell lung cancer: rationale, evidence and place in therapy

PubMed Central

Ricciuti, Biagio; Baglivo, Sara; Paglialunga, Luca; De Giglio, Andrea; Bellezza, Guido; Chiari, Rita; Crinò, Lucio; Metro, Giulio

2017-01-01

The identification of epidermal growth factor receptor (EGFR) mutations represented a fundamental step forward in the treatment of advanced non-small cell lung cancer (NSCLC) as they define a subset of patients who benefit from the administration of specifically designed targeted therapies. The inhibition of mutant EGFR through EGFR-tyrosine kinase inhibitors (TKIs), either reversible, first-generation gefitinib and erlotinib, or irreversible, second-generation afatinib, has dramatically improved the prognosis of patients harboring this specific genetic alteration, leading to unexpected clinical benefit. Unfortunately, virtually all patients who initially respond to treatment develop acquired resistance to EGFR-TKIs within 9–14 months. The EGFR T790M secondary mutation has emerged as a cause of treatment failure in approximately 60% of resistant cases. To date, several compounds designed with the aim to overcome T790M-mediated resistance are under clinical investigation. The aim of this review is to discuss emerging data regarding the third-generation EGFR-TKI, osimertinib, for the treatment of EGFR T790M mutant advanced NSCLC. PMID:28607578

FGFR3 gene mutation plus GRB10 gene duplication in a patient with achondroplasia plus growth delay with prenatal onset.

PubMed

Yuan, Haiming; Huang, Linhuan; Hu, Xizi; Li, Qian; Sun, Xiaofang; Xie, Yingjun; Kong, Shu; Wang, Xiaoman

2016-07-02

Achondroplasia is a well-defined and common bone dysplasia. Genotype- and phenotype-level correlations have been found between the clinical symptoms of achondroplasia and achondroplasia-specific FGFR3 mutations. A 2-year-old boy with clinical features consistent with achondroplasia and Silver-Russell syndrome-like symptoms was found to carry a mutation in the fibroblast growth factor receptor-3 (FGFR3) gene at c.1138G > A (p.Gly380Arg) and a de novo 574 kb duplication at chromosome 7p12.1 that involved the entire growth-factor receptor bound protein 10 (GRB10) gene. Using quantitative real-time PCR analysis, GRB10 was over-expressed, and, using enzyme-linked immunosorbent assays for IGF1 and IGF-binding protein-3 (IGFBP3), we found that IGF1 and IGFBP3 were low-expressed in this patient. We demonstrate that a combination of uncommon, rare and exceptional molecular defects related to the molecular bases of particular birth defects can be analyzed and diagnosed to potentially explain the observed variability in the combination of molecular defects.

Discovery of Selective and Noncovalent Diaminopyrimidine-Based Inhibitors of Epidermal Growth Factor Receptor Containing the T790M Resistance Mutation

PubMed Central

2015-01-01

Activating mutations within the epidermal growth factor receptor (EGFR) kinase domain, commonly L858R or deletions within exon 19, increase EGFR-driven cell proliferation and survival and are correlated with impressive responses to the EGFR inhibitors erlotinib and gefitinib in nonsmall cell lung cancer patients. Approximately 60% of acquired resistance to these agents is driven by a single secondary mutation within the EGFR kinase domain, specifically substitution of the gatekeeper residue threonine-790 with methionine (T790M). Due to dose-limiting toxicities associated with inhibition of wild-type EGFR (wtEGFR), we sought inhibitors of T790M-containing EGFR mutants with selectivity over wtEGFR. We describe the evolution of HTS hits derived from Jak2/Tyk2 inhibitors into selective EGFR inhibitors. X-ray crystal structures revealed two distinct binding modes and enabled the design of a selective series of novel diaminopyrimidine-based inhibitors with good potency against T790M-containing mutants of EGFR, high selectivity over wtEGFR, broad kinase selectivity, and desirable physicochemical properties. PMID:25383627

Uterine metastasis of lung adenocarcinoma under molecular target therapy with epidermal growth factor receptor tyrosine kinase inhibitors: A case report and review of the literature.

PubMed

Shibata, Mayu; Shizu, Masato; Watanabe, Kazuko; Takeda, Akihiro

2018-02-01

A 63-year-old woman presented with abnormal vaginal bleeding. Her disease history was significant, and included advanced lung adenocarcinoma with a deletion mutation in exon 19 of the epidermal growth factor receptor (EGFR) gene, which was managed by concurrent chemoradiotherapy, followed by molecular targeted therapy with tyrosine kinase inhibitors (TKIs) for a two-year period. Contrast-enhanced computed tomography showed the enlargement of a previously suspicious myoma node, with peripheral enhancement. Hemorrhagic necrosis was also observed on magnetic resonance imaging. Transabdominal hysterectomy and bilateral salpingo-oophorectomy showed solitary intramyometrial metastatic lung adenocarcinoma with a second-site T790M gatekeeper mutation in exon 20 of the EGFR gene. In conclusion, uterine metastasis from lung adenocarcinoma can present a diagnostic challenge. The possibility of lung cancer metastasis should be considered when a uterine mass increases in size during treatment. Molecular analysis of the EGFR gene to detect mutations could provide useful information for planning the treatment strategy. © 2017 Japan Society of Obstetrics and Gynecology.

Management of Patients With Adenocarcinoma or Squamous Cancer of the Esophagus.

PubMed

Ilson, David H; van Hillegersberg, Richard

2018-01-01

Esophageal cancer is characterized by early and frequent metastasis. Surgery is the primary treatment for early-stage disease, whereas patients with patients with locally advanced disease receive perioperative chemotherapy or chemoradiotherapy. Squamous cancers can be treated with primary chemoradiotherapy without surgery, depending on their response to therapy and patient tolerance for subsequent surgery. Chemotherapy with a fluorinated pyrimidine and a platinum agent, followed by later treatment with taxanes and irinotecan, provides some benefit. Agents that inhibit the erb-b2 receptor tyrosine kinase 2 (ERBB2 or HER2), or vascular endothelial growth factor, including trastuzumab, ramucirumab, and apatinib, increase response and survival times. Esophageal adenocarcinomas have mutations in tumor protein p53 and mutations that activate receptor-associated tyrosine kinase, vascular endothelial growth factor, and cell cycle pathways, whereas esophageal squamous tumors have a distinct set of mutations. Esophageal cancers develop systems to evade anti-tumor immune responses, but studies are needed to determine how immune checkpoint modification contributes to esophageal tumor development. Copyright © 2018 AGA Institute. Published by Elsevier Inc. All rights reserved.

Clinical and economic aspects of KRAS mutational status as predictor for epidermal growth factor receptor inhibitor therapy in metastatic colorectal cancer patients.

PubMed

Königsberg, Robert; Hulla, Wolfgang; Klimpfinger, Martin; Reiner-Concin, Angelika; Steininger, Tanja; Büchler, Wilfried; Terkola, Robert; Dittrich, Christian

2011-01-01

Treatment of metastasized colorectal cancer (mCRC) patients with anti-epidermal growth factor receptor (EGFR)-directed monoclonal antibodies is driven by the results of the KRAS mutational status (wild type [WT]/mutated [MUT]). To find out as to what extent the treatment selection based on the KRAS status had impact on overall costs, a retrospective analysis was performed. Of 73 mCRC patients 31.5% were MUT carriers. Costs of EGFR inhibitor treatment for WT patients were significantly higher compared to those for patients with MUT (p = 0.005). Higher treatment costs in WT carriers reflect a significantly higher number of treatment cycles (p = 0.012) in this cohort of patients. Savings of drug costs minus the costs for the determination of KRAS status accounted for EUR 779.42 (SD ±336.28) per patient per cycle. The routine use of KRAS screening is a cost-effective strategy. Costs of unnecessary monoclonal EGFR inhibitor treatment can be saved in MUT patients. Copyright © 2012 S. Karger AG, Basel.

Germline Mutations in BMPR1A/ALK3 Cause a Subset of Cases of Juvenile Polyposis Syndrome and of Cowden and Bannayan-Riley-Ruvalcaba Syndromes*

PubMed Central

Zhou, Xiao-Ping; Woodford-Richens, Kelly; Lehtonen, Rainer; Kurose, Keisuke; Aldred, Micheala; Hampel, Heather; Launonen, Virpi; Virta, Sanno; Pilarski, Robert; Salovaara, Reijo; Bodmer, Walter F.; Conrad, Beth A.; Dunlop, Malcolm; Hodgson, Shirley V.; Iwama, Takeo; Järvinen, Heikki; Kellokumpu, Ilmo; Kim, J. C.; Leggett, Barbara; Markie, David; Mecklin, Jukka-Pekka; Neale, Kay; Phillips, Robin; Piris, Juan; Rozen, Paul; Houlston, Richard S.; Aaltonen, Lauri A.; Tomlinson, Ian P. M.; Eng, Charis

2001-01-01

Juvenile polyposis syndrome (JPS) is an inherited hamartomatous-polyposis syndrome with a risk for colon cancer. JPS is a clinical diagnosis by exclusion, and, before susceptibility genes were identified, JPS could easily be confused with other inherited hamartoma syndromes, such as Bannayan-Riley-Ruvalcaba syndrome (BRRS) and Cowden syndrome (CS). Germline mutations of MADH4 (SMAD4) have been described in a variable number of probands with JPS. A series of familial and isolated European probands without MADH4 mutations were analyzed for germline mutations in BMPR1A, a member of the transforming growth-factor β–receptor superfamily, upstream from the SMAD pathway. Overall, 10 (38%) probands were found to have germline BMPR1A mutations, 8 of which resulted in truncated receptors and 2 of which resulted in missense alterations (C124R and C376Y). Almost all available component tumors from mutation-positive cases showed loss of heterozygosity (LOH) in the BMPR1A region, whereas those from mutation-negative cases did not. One proband with CS/CS-like phenotype was also found to have a germline BMPR1A missense mutation (A338D). Thus, germline BMPR1A mutations cause a significant proportion of cases of JPS and might define a small subset of cases of CS/BRRS with specific colonic phenotype. PMID:11536076

Retrospective study of adjuvant icotinib in postoperative lung cancer patients harboring epidermal growth factor receptor mutations.

PubMed

Yao, Shuyang; Zhi, Xiuyi; Wang, Ruotian; Qian, Kun; Hu, Mu; Zhang, Yi

2016-09-01

Epidermal growth factor receptor (EGFR) mutations occur in about 50% of Asian patients with non-small cell lung cancer (NSCLC). Patients with advanced NSCLC and EGFR mutations derive clinical benefit from treatment with EGFR-tyrosine kinase inhibitors (TKIs). This study assessed the efficacy and safety of adjuvant icotinib without chemotherapy in EGFR-mutated NSCLC patients undergoing resection of stage IB-IIIA. Our retrospective study enrolled 20 patients treated with icotinib as adjuvant therapy. Survival factors were evaluated by univariate and Cox regression analysis. The median follow-up time was 30 months (range 24-41). At the data cut-off, five patients (25%) had recurrence or metastasis and one patient had died of the disease. The two-year disease-free survival (DFS) rate was 85%. No recurrence occurred in the high-risk stage IB subgroup during the follow-up period. In univariate analysis, the micropapillary pattern had a statistically significant effect on DFS ( P = 0.040). Multivariate logistic regression analysis showed that there was no independent predictor. Drug related adverse events (AEs) occurred in nine patients (45.0%). The most common AEs were skin-related events and diarrhea, but were relatively mild. No grade 3 AEs or occurrences of intolerable toxicity were observed. Icotinib as adjuvant therapy is effective in patients harboring EGFR mutations after complete resection, with an acceptable AE profile. Further trials with larger sample sizes might confirm the efficiency of adjuvant TKI in selected patients. © 2016 The Authors. Thoracic Cancer published by China Lung Oncology Group and John Wiley & Sons Australia, Ltd.

Impact of tissue type and content of neoplastic cells of samples on the quality of epidermal growth factor receptor mutation analysis among patients with lung adenocarcinoma

PubMed Central

PALIOGIANNIS, PANAGIOTIS; ATTENE, FEDERICO; COSSU, ANTONIO; DEFRAIA, EFISIO; PORCU, GIUSEPPE; CARTA, ANNAMARIA; SOTGIU, MARIA IGNAZIA; PAZZOLA, ANTONIO; CORDERO, LORENZO; CAPELLI, FRANCESCA; FADDA, GIOVANNI MARIA; ORTU, SALVATORE; SOTGIU, GIOVANNI; PALOMBA, GRAZIA; SINI, MARIA CRISTINA; PALMIERI, GIUSEPPE; COLOMBINO, MARIA

2015-01-01

Assessment of the epidermal growth factor receptor (EGFR) mutational status has become crucial in recent years in the molecular classification of patients with lung cancer. The impact of the type and quantity of malignant cells of the neoplastic specimen on the quality of mutation analysis remains to be elucidated, and only empirical and sporadic data are available. The aim of the present study was to investigate the impact of tissue type and content of neoplastic cells in the specimen on the quality of EGFR mutation analysis among patients with lung adenocarcinoma. A total of 515 patients with histologically-confirmed disease were included in the present study. Formalin-fixed paraffin embedded tissue samples were used for the mutation analysis and the content of the neoplastic cells was evaluated using light microscopy. Genomic DNA was isolated using a standard protocol. The coding sequences and splice junctions of exons 18, 19 and 21 in the EGFR gene were then screened for mutations by direct automated sequencing. The mean age of the patients examined was 64.9 years and 357 (69.3%) were male. A total of 429 tissue samples (83.3%) were obtained by biopsy and the remaining samples were obtained by surgery. A total of 456 samples (88.5%) were observed from primary lung adenocarcinomas, while 59 (11.5%) were from metastatic lesions. EGFR mutations occurred in 59 cases (11.5%); exon 18 mutations were detected in one case (1.7%), whereas exon 19 and 21 mutations were detected in 30 (51%) and 28 (47.3%) cases, respectively. EGFR mutations were more frequent in females and patients that had never smoked. The distribution of the mutations among primary and metastatic tissues exhibited no significant differences in the proportions of EGFR mutations detected. However, a statistically significant difference in the number of mutations detected was found between samples with at least 50% of neoplastic cells (450 cases-57 mutations; 12.7%) and those with <50% of neoplastic cells (65 cases-2 mutations; 3.1%). PMID:25683726

Why is intelligence correlated with semen quality?: Biochemical pathways common to sperm and neuron function and their vulnerability to pleiotropic mutations.

PubMed

Pierce, Arand; Miller, Geoffrey; Arden, Rosalind; Gottfredson, Linda S

2009-09-01

We recently found positive correlations between human general intelligence and three key indices of semen quality, and hypothesized that these correlations arise through a phenotype-wide 'general fitness factor' reflecting overall mutation load. In this addendum we consider some of the biochemical pathways that may act as targets for pleiotropic mutations that disrupt both neuron function and sperm function in parallel. We focus especially on the inter-related roles of polyunsaturated fatty acids, exocytosis and receptor signaling.

A case of thanatophoric dysplasia type 2: a novel mutation.

PubMed

Gülaşı, Selvi; Atıcı, Aytuğ; Çelik, Yalçın

2015-03-01

Thanatophoric dysplasia (TD) is a lethal form of skeletal dysplasia with short-limb dwarfism. Two types distinguished with their radiological characteristics have been defined clinically. The femur is curved in type 1, while it is straight in type 2. TD is known to be due to a mutation in the fibroblast growth factor receptor 3 (FGFR3) gene. We report a male patient who showed clinical findings congruent with TD type 2 and a new mutation in the FGFR3 gene, a finding which has not been reported previously.

Growth Hormone Receptor Mutations Related to Individual Dwarfism

PubMed Central

Li, Charles; Zhang, Xiquan

2018-01-01

Growth hormone (GH) promotes body growth by binding with two GH receptors (GHRs) at the cell surface. GHRs interact with Janus kinase, signal transducers, and transcription activators to stimulate metabolic effects and insulin-like growth factor (IGF) synthesis. However, process dysfunctions in the GH–GHR–IGF-1 axis cause animal dwarfism. If, during the GH process, GHR is not successfully recognized and/or bound, or GHR fails to transmit the GH signal to IGF-1, the GH dysfunction occurs. The goal of this review was to focus on the GHR mutations that lead to failures in the GH–GHR–IGF-1 signal transaction process in the dwarf phenotype. Until now, more than 90 GHR mutations relevant to human short stature (Laron syndrome and idiopathic short stature), including deletions, missense, nonsense, frameshift, and splice site mutations, and four GHR defects associated with chicken dwarfism, have been described. Among the 93 identified mutations of human GHR, 68 occur extracellularly, 13 occur in GHR introns, 10 occur intracellularly, and two occur in the transmembrane. These mutations interfere with the interaction between GH and GHRs, GHR dimerization, downstream signaling, and the expression of GHR. These mutations cause aberrant functioning in the GH-GHR-IGF-1 axis, resulting in defects in the number and diameter of muscle fibers as well as bone development. PMID:29748515

Identifying three-dimensional structures of autophosphorylation complexes in crystals of protein kinases

PubMed Central

Xu, Qifang; Malecka, Kimberly L.; Fink, Lauren; Jordan, E. Joseph; Duffy, Erin; Kolander, Samuel; Peterson, Jeffrey; Dunbrack, Roland L.

2016-01-01

Protein kinase autophosphorylation is a common regulatory mechanism in cell signaling pathways. Crystal structures of several homomeric protein kinase complexes have a serine, threonine, or tyrosine autophosphorylation site of one kinase monomer located in the active site of another monomer, a structural complex that we call an “autophosphorylation complex.” We developed and applied a structural bioinformatics method to identify all such autophosphorylation kinase complexes in X-ray crystallographic structures in the Protein Data Bank (PDB). We identified 15 autophosphorylation complexes in the PDB, of which 5 complexes had not previously been described in the publications describing the crystal structures. These 5 consist of tyrosine residues in the N-terminal juxtamembrane regions of colony stimulating factor 1 receptor (CSF1R, Tyr561) and EPH receptor A2 (EPHA2, Tyr594), tyrosine residues in the activation loops of the SRC kinase family member LCK (Tyr394) and insulin-like growth factor 1 receptor (IGF1R, Tyr1166), and a serine in a nuclear localization signal region of CDC-like kinase 2 (CLK2, Ser142). Mutations in the complex interface may alter autophosphorylation activity and contribute to disease; therefore we mutated residues in the autophosphorylation complex interface of LCK and found that two mutations impaired autophosphorylation (T445V and N446A) and mutation of Pro447 to Ala, Gly, or Leu increased autophosphorylation. The identified autophosphorylation sites are conserved in many kinases, suggesting that, by homology, these complexes may provide insight into autophosphorylation complex interfaces of kinases that are relevant drug targets. PMID:26628682

Efficacy of icotinib versus traditional chemotherapy as first-line treatment for preventing brain metastasis from advanced lung adenocarcinoma in patients with epidermal growth factor receptor-sensitive mutation.

PubMed

Zhao, Xiao; Zhu, Guangqin; Chen, Huoming; Yang, Ping; Li, Fang; Du, Nan

2016-01-01

This study aimed to investigate the potential use of icotinib as first-line treatment to prevent brain metastasis from advanced lung adenocarcinoma. This investigation was designed as a retrospective nonrandomized controlled study. Enrolled patients received either icotinib or traditional chemotherapy as their first-line treatment. The therapeutic efficacy was compared among patients with advanced. (stages IIIB and IV) lung adenocarcinoma with epidermal growth factor receptor (EGFR)-sensitive mutation. The primary endpoint was the cumulative incidence of brain metastasis, whereas, the secondary endpoint was overall survival(OS). Death without brain metastasis was considered a competitive risk to calculate the cumulative risk of brain metastasis. Survival analysis was conducted using the Kaplan-Meier method and statistical significance was determined using the log-rank test. The present study included 396 patients with 131 in the icotinib group and 265 in the chemotherapy group. Among those with EGFR-sensitive mutation, the cumulative risk of brain metastasis was lower in the icotinib group than in the chemotherapy group. However, no significant difference in OS was observed between the two groups. Icotinib can effectively reduce the incidence of brain metastasis and therefore improve prognosis in advanced lung adenocarcinoma patients with EGFR.sensitive mutation.

Efficacy of icotinib versus traditional chemotherapy as first-line treatment for preventing brain metastasis from advanced lung adenocarcinoma in patients with epidermal growth factor receptor-sensitive mutation.

PubMed

Zhao, Xiao; Zhu, Guangqin; Chen, Huoming; Yang, Ping; Li, Fang; Du, Nan

2014-11-01

This study aimed to investigate the potential use of icotinib as first-line treatment to prevent brain metastasis from advanced lung adenocarcinoma. This investigation was designed as a retrospective nonrandomized controlled study. Enrolled patients received either icotinib or traditional chemotherapy as their first-line treatment. The therapeutic efficacy was compared among patients with advanced (stages IIIB and IV) lung adenocarcinoma with epidermal growth factor receptor (EGFR)-sensitive mutation. The primary endpoint was the cumulative incidence of brain metastasis, whereas the secondary endpoint was overall survival (OS). Death without brain metastasis was considered a competitive risk to calculate the cumulative risk of brain metastasis. Survival analysis was conducted using the Kaplan-Meier method and statistical significance were determined using the log-rank test. The present study included 396 patients with 131 in the icotinib group and 265 in the chemotherapy group. Among those with EGFR-sensitive mutation, the cumulative risk of brain metastasis was lower in the icotinib group than in the chemotherapy group. However, no significant difference in OS was observed between the two groups. Icotinib can effectively reduce the incidence of brain metastasis and therefore improve prognosis in advanced lung adenocarcinoma patients with EGFR-sensitive mutation.

Molecular concept in human oral cancer.

PubMed

Krishna, Akhilesh; Singh, Shraddha; Kumar, Vijay; Pal, U S

2015-01-01

The incidence of oral cancer remains high in both Asian and Western countries. Several risk factors associated with development of oral cancer are now well-known, including tobacco chewing, smoking, and alcohol consumption. Cancerous risk factors may cause many genetic events through chromosomal alteration or mutations in genetic material and lead to progression and development of oral cancer through histological progress, carcinogenesis. Oral squamous carcinogenesis is a multistep process in which multiple genetic events occur that alter the normal functions of proto-oncogenes/oncogenes and tumor suppressor genes. Furthermore, these gene alterations can deregulate the normal activity such as increase in the production of growth factors (transforming growth factor-α [TGF-α], TGF-β, platelet-derived growth factor, etc.) or numbers of cell surface receptors (epidermal growth factor receptor, G-protein-coupled receptor, etc.), enhanced intracellular messenger signaling and mutated production of transcription factors (ras gene family, c-myc gene) which results disturb to tightly regulated signaling pathways of normal cell. Several oncogenes and tumor suppressor genes have been implicated in oral cancer especially cyclin family, ras, PRAD-1, cyclin-dependent kinase inhibitors, p53 and RB1. Viral infections, particularly with oncogenic human papilloma virus subtype (16 and 18) and Epstein-Barr virus have tumorigenic effect on oral epithelia. Worldwide, this is an urgent need to initiate oral cancer research programs at molecular and genetic level which investigates the causes of genetic and molecular defect, responsible for malignancy. This approach may lead to development of target dependent tumor-specific drugs and appropriate gene therapy.

Molecular concept in human oral cancer

PubMed Central

Krishna, Akhilesh; Singh, Shraddha; Kumar, Vijay; Pal, U. S.

2015-01-01

The incidence of oral cancer remains high in both Asian and Western countries. Several risk factors associated with development of oral cancer are now well-known, including tobacco chewing, smoking, and alcohol consumption. Cancerous risk factors may cause many genetic events through chromosomal alteration or mutations in genetic material and lead to progression and development of oral cancer through histological progress, carcinogenesis. Oral squamous carcinogenesis is a multistep process in which multiple genetic events occur that alter the normal functions of proto-oncogenes/oncogenes and tumor suppressor genes. Furthermore, these gene alterations can deregulate the normal activity such as increase in the production of growth factors (transforming growth factor-α [TGF-α], TGF-β, platelet-derived growth factor, etc.) or numbers of cell surface receptors (epidermal growth factor receptor, G-protein-coupled receptor, etc.), enhanced intracellular messenger signaling and mutated production of transcription factors (ras gene family, c-myc gene) which results disturb to tightly regulated signaling pathways of normal cell. Several oncogenes and tumor suppressor genes have been implicated in oral cancer especially cyclin family, ras, PRAD-1, cyclin-dependent kinase inhibitors, p53 and RB1. Viral infections, particularly with oncogenic human papilloma virus subtype (16 and 18) and Epstein-Barr virus have tumorigenic effect on oral epithelia. Worldwide, this is an urgent need to initiate oral cancer research programs at molecular and genetic level which investigates the causes of genetic and molecular defect, responsible for malignancy. This approach may lead to development of target dependent tumor-specific drugs and appropriate gene therapy. PMID:26668446

Comparison of plasma and tissue samples in epidermal growth factor receptor mutation by ARMS in advanced non-small cell lung cancer.

PubMed

Ma, MeiLi; Shi, ChunLei; Qian, JiaLin; Teng, JiaJun; Zhong, Hua; Han, BaoHui

2016-10-10

The aim of this study was to assess the effectiveness and accuracy of blood-based circulating-free tumor DNA on testing epidermal growth factor receptor (EGFR) gene mutations. In total, 219 non-small cell lung cancer patients in stages III-IV were enrolled into this study. All patients had tissue samples and matched plasma DNA samples. EGFR gene mutations were detected by the Amplification Refractory Mutation System (ARMS). We compared the mutations in tumor tissue samples with matched plasma samples and determined the correlation between EGFR mutation status and clinical pathologic characteristics. The overall concordance rate of EGFR mutation status between the 219 matched plasma and tissue samples was 82% (179/219). The sensitivity and specificity for the ARMS EGFR mutation test in the plasma compared with tumor tissue were 60% (54/90) and 97% (125/129), respectively. The positive predictive value was 93% (54/58) and the negative predictive value was 78% (125/161). The median overall survival was longer for those with EGFR mutations than for those without EGFR mutations both in tissue samples (23.98 vs. 12.16months; P<0.001) and in plasma (19.96 vs. 13.63months; P=0.009). For the 68 patients treated with EGFR- tyrosine kinase inhibitors (TKIs), the median progression-free survival (PFS) was significantly prolonged in the EGFR mutant group compared to the non-mutation group in tumor tissue samples (12.26months vs. 2.40months, P<0.001). In plasma samples, the PFS of the mutant group was longer than that of the non-mutant group. However, there was no significant difference between the two groups (10.88months vs. 9.89months, P=0.411). The detection of EGFR mutations in plasma using ARMS is relatively sensitive and highly specific. However, EGFR mutation status tested by ARMS in plasma cannot replace a tumor tissue biopsy. Positive EGFR mutation results detected in plasma are fairly reliable, but negative results are hampered by a high rate of false negatives. Copyright © 2016. Published by Elsevier B.V.

Acquired resistance L747S mutation in an epidermal growth factor receptor-tyrosine kinase inhibitor-naïve patient: A report of three cases.

PubMed

Yamaguchi, Fumihiro; Fukuchi, Kunihiko; Yamazaki, Yohei; Takayasu, Hiromi; Tazawa, Sakiko; Tateno, Hidetsugu; Kato, Eisuke; Wakabayashi, Aya; Fujimori, Mami; Iwasaki, Takuya; Hayashi, Makoto; Tsuchiya, Yutaka; Yamashita, Jun; Takeda, Norikazu; Kokubu, Fumio

2014-02-01

The purpose of the present study was to report cases of epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI)-naïve patients carrying a mutation associated with acquired resistance to the drug. Gene alterations in 77 lung carcinoma patients were analyzed by collecting and studying curette lavage fluid at the time of diagnosis. PCRs were performed to amplify mutation hotspot regions in EGFR genes. The PCR products were direct-sequenced and the mutations confirmed by resequencing using different primers. Case 1 was a 78-year-old Japanese male diagnosed with stage IB lung adenocarcinoma who was found to have two EGFR mutations, G719S and L747S. Case 2 was a 73-year-old Japanese male diagnosed with stage IV squamous cell lung carcinoma and bone metastasis who had the EGFR mutation, L747S. Case 3 was an 82-year-old Japanese male diagnosed with hyponatremia due to inappropriate secretion of antidiuretic hormone and stage IIIB small cell lung carcinoma (SCLC) who had the EGFR mutation, L747S. Thus, the EGFR mutation L747S associated with acquired EGFR-TKI resistance was detected in two non-small cell lung carcinoma (NSCLC) patients and one SCLC patient, none of whom had ever received EGFR-TKI. The patients were current smokers with stages at diagnosis ranging from IB to IV, and their initial tumors contained resistant clones carrying L747S. L747S may be associated with primary resistance. To the best of our knowledge, this study is the first report of an EGFR mutation associated with resistance to EGFR-TKI in SCLC patients. The early detection of EGFR-TKI resistance mutations may be beneficial in making treatment decisions for lung carcinoma patients, including those with SCLC.

Suppression of severe achondroplasia with developmental delay and acanthosis nigricans by the p.Thr651Pro mutation.

PubMed

Manickam, Kandamurugu; Donoghue, Daniel J; Meyer, April N; Snyder, Pamela J; Prior, Thomas W

2014-01-01

Severe achondroplasia with developmental delay and acanthosis nigricans (SADDAN) is an extremely rare severe skeletal dysplasia characterized by significant developmental delay, brain structural abnormalities, hearing loss, and acanthosis nigricans. The disorder is the result of a single missense mutation at codon 650 (p.Lys650Met) in the fibroblast growth factor receptor 3 gene (FGFR3). We describe a child who initially presented with a mild achondroplasia or hypochondroplasia like phenotype. Molecular analysis of the FGFR3 gene showed the common SADDAN mutation and a second novel mutation at codon 651 (p.Thr651Pro). Both mutations were shown to occur on the same allele (cis) and de novo. Transient transfection studies with FGFR3 double mutant constructs show that the p.Thr651Pro mutation causes a dramatic decrease in constitutive receptor kinase activity than that observed by the p.Lys650Met mutation. Our data suggest that the molecular effect by the p.Thr651Pro is to elicit a conformational change that decreases the FGFR3 tyrosine kinase activity, which is constitutively activated by the SADDAN mutation. Due to the inheritance of both a gain-of-function and a loss-of-function mutation, we conclude that a reduction of constitutive activation caused the milder skeletal phenotype. Although the occurrence of double mutations are expected to be rare, the presence of other FGFR3 modifiers may be responsible for some of the clinically discrepant skeletal dysplasia cases. © 2013 Wiley Periodicals, Inc.

Determination of the exact molecular requirements for type 1 angiotensin receptor epidermal growth factor receptor transactivation and cardiomyocyte hypertrophy.

PubMed

Smith, Nicola J; Chan, Hsiu-Wen; Qian, Hongwei; Bourne, Allison M; Hannan, Katherine M; Warner, Fiona J; Ritchie, Rebecca H; Pearson, Richard B; Hannan, Ross D; Thomas, Walter G

2011-05-01

Major interest surrounds how angiotensin II triggers cardiac hypertrophy via epidermal growth factor receptor transactivation. G protein-mediated transduction, angiotensin type 1 receptor phosphorylation at tyrosine 319, and β-arrestin-dependent scaffolding have been suggested, yet the mechanism remains controversial. We examined these pathways in the most reductionist model of cardiomyocyte growth, neonatal ventricular cardiomyocytes. Analysis with [(32)P]-labeled cardiomyocytes, wild-type and [Y319A] angiotensin type 1 receptor immunoprecipitation and phosphorimaging, phosphopeptide analysis, and antiphosphotyrosine blotting provided no evidence for tyrosine phosphorylation at Y319 or indeed of the receptor, and mutation of Y319 (to A/F) did not prevent either epidermal growth factor receptor transactivation in COS-7 cells or cardiomyocyte hypertrophy. Instead, we demonstrate that transactivation and cardiomyocyte hypertrophy are completely abrogated by loss of G-protein coupling, whereas a constitutively active angiotensin type 1 receptor mutant was sufficient to trigger transactivation and growth in the absence of ligand. These results were supported by the failure of the β-arrestin-biased ligand SII angiotensin II to transactivate epidermal growth factor receptor or promote hypertrophy, whereas a β-arrestin-uncoupled receptor retained these properties. We also found angiotensin II-mediated cardiomyocyte hypertrophy to be attenuated by a disintegrin and metalloprotease inhibition. Thus, G-protein coupling, and not Y319 phosphorylation or β-arrestin scaffolding, is required for epidermal growth factor receptor transactivation and cardiomyocyte hypertrophy via the angiotensin type 1 receptor.

An exon 53 frameshift mutation in CUBN abrogates cubam function and causes Imerslund-Gräsbeck syndrome in dogs

PubMed Central

Fyfe, John C.; Hemker, Shelby L.; Venta, Patrick J.; Fitzgerald, Caitlin A.; Outerbridge, Catherine A.; Myers, Sherry L.; Giger, Urs

2013-01-01

Cobalamin malabsorption accompanied by selective proteinuria is an autosomal recessive disorder known as Imerslund-Gräsbeck syndrome in humans and was previously described in dogs due to amnionless (AMN) mutations. The resultant vitamin B12 deficiency causes dyshematopoiesis, lethargy, failure to thrive, and life-threatening metabolic disruption in the juvenile period. We studied 3 kindreds of border collies with cobalamin malabsorption and mapped the disease locus in affected dogs to a 2.9 Mb region of homozygosity on canine chromosome 2. The region included CUBN, the locus encoding cubilin, a peripheral membrane protein that in concert with AMN forms the functional intrinsic factor-cobalamin receptor expressed in ileum and a multi-ligand receptor in renal proximal tubules. Cobalamin malabsorption and proteinuria comprising CUBN ligands were demonstrated by radiolabeled cobalamin uptake studies and SDS-PAGE, respectively. CUBN mRNA and protein expression were reduced ~10 fold and ~20 fold, respectively, in both ileum and kidney of affected dogs. DNA sequencing demonstrated a single base deletion in exon 53 predicting a translational frameshift and early termination codon likely triggering nonsense mediated mRNA decay. The mutant allele segregated with disease in the border collie kindred. The border collie disorder indicates that a CUBN mutation far C-terminal from the intrinsic factor-cobalamin binding site can abrogate receptor expression and cause Imerslund-Gräsbeck syndrome. PMID:23746554

Recent Management of Patients with Advanced Epidermal Growth Factor Receptor Mutation Non-small Cell Lung Cancer: Role of Afatinib and Lesson Learned for Developing Countries.

PubMed

Amin, Zulkifli; Jayalie, Vito Filbert; Rajabto, Wulyo

2017-01-01

Lung cancer is a devastating disease with a high incidence, mortality and morbidity rate, especially in developing countries. Conventional treatment with cytotoxic chemotherapy has some limitations attributed to chemoresistance and toxicity. Recent advances have shown that first generation Tyrosine Kinase Inhibitor (TKI), Gefitinib and Erlotinib, and the newest available second generation Tyrosine Kinase Inhibitor (TKI), Afatinib, have the potential to be an option in the management of patients with epidermal growth factor receptor/ EGFR mutation positive advanced/ metastatic non-small cell lung cancer. Afatinib works by binding to EGFR irreversibly, thus inactivating the tyrosine kinase receptor. Some studies demostrated that Afatinib first-line may result in longer progression free survival (PFS) and better disease control, and as an alternative for patients who intolerance to Gefitinib or Erlotinib. In Indonesia, the era of National Health Insurance has been implemented and National Health Insurance has covered treatment for cancer, including first generation TKIs, Gefitinib dan erlotinib, for patients with EGFR mutation positive advanced/ metastatic non-small cell lung cancer at Cipto Mangunkusumo National Hospital. Afatinib, as one of the newest available second generation TKI, may be given free of charge too as an alternative if the National Health Insurance will be covered in the future. Further research is needed to know the efficacy and adverse effects that may occur in patients from developing countries.

Targeting the Golgi apparatus to overcome acquired resistance of non-small cell lung cancer cells to EGFR tyrosine kinase inhibitors

PubMed Central

Katayama, Ryohei; Fang, Siyang; Tsutsui, Saki; Akatsuka, Akinobu; Shan, Mingde; Choi, Hyeong-Wook; Fujita, Naoya; Yoshimatsu, Kentaro; Shiina, Isamu; Yamori, Takao; Dan, Shingo

2018-01-01

Epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (EGFR-TKIs) were demonstrated to provide survival benefit in patients with non-small cell lung cancer (NSCLC) harboring activating mutations of EGFR; however, emergence of acquired resistance to EGFR-TKIs has been shown to cause poor outcome. To overcome the TKI resistance, drugs with different mode of action are required. We previously reported that M-COPA (2-methylcoprophilinamide), a Golgi disruptor, suppressed the growth of gastric cancers overexpressing receptor tyrosine kinases (RTKs) such as hepatocyte growth factor receptor (MET) via downregulating their cell surface expression. In this study, we examined the antitumor effect of M-COPA on NSCLC cells with TKI resistance. As a result, M-COPA effectively downregulated cell surface EGFR and its downstream signals, and finally exerted in vivo antitumor effect in NSCLC cells harboring secondary (T790M/del19) and tertiary (C797S/T790M/del19) mutated EGFR, which exhibit acquired resistance to first- and third generation EGFR-TKIs, respectively. M-COPA also downregulated MET expression potentially involved in the acquired resistance to EGFR-TKIs via bypassing the EGFR pathway blockade. These results provide the first evidence that targeting the Golgi apparatus might be a promising therapeutic strategy to overcome the vicious cycle of TKI resistance in EGFR-mutated NSCLC cells via downregulating cell surface RTK expression. PMID:29416720

Functional interplay between secreted ligands and receptors in melanoma.

PubMed

Herraiz, Cecilia; Jiménez-Cervantes, Celia; Sánchez-Laorden, Berta; García-Borrón, José C

2018-06-01

Melanoma, the most aggressive form of skin cancer, results from the malignant transformation of melanocytes located in the basement membrane separating the epidermal and dermal skin compartments. Cutaneous melanoma is often initiated by solar ultraviolet radiation (UVR)-induced mutations. Melanocytes intimately interact with keratinocytes, which provide growth factors and melanocortin peptides acting as paracrine regulators of proliferation and differentiation. Keratinocyte-derived melanocortins activate melanocortin-1 receptor (MC1R) to protect melanocytes from the carcinogenic effect of UVR. Accordingly, MC1R is a major determinant of susceptibility to melanoma. Despite extensive phenotypic heterogeneity and high mutation loads, the molecular basis of melanomagenesis and the molecules mediating the crosstalk between melanoma and stromal cells are relatively well understood. Mutations of intracellular effectors of receptor tyrosine kinase (RTK) signalling, notably NRAS and BRAF, are major driver events more frequent than mutations in RTKs. Nevertheless, melanomas often display aberrant signalling from RTKs such as KIT, ERRB1-4, FGFR, MET and PDGFR, which contribute to disease progression and resistance to targeted therapies. Progress has also been made to unravel the role of the tumour secretome in preparing the metastatic niche. However, key aspects of the melanoma-stroma interplay, such as the molecular determinants of dormancy, remain poorly understood. Copyright © 2017 Elsevier Ltd. All rights reserved.

KRAS mutation testing in metastatic colorectal cancer

PubMed Central

Tan, Cong; Du, Xiang

2012-01-01

The KRAS oncogene is mutated in approximately 35%-45% of colorectal cancers, and KRAS mutational status testing has been highlighted in recent years. The most frequent mutations in this gene, point substitutions in codons 12 and 13, were validated as negative predictors of response to anti-epidermal growth factor receptor antibodies. Therefore, determining the KRAS mutational status of tumor samples has become an essential tool for managing patients with colorectal cancers. Currently, a variety of detection methods have been established to analyze the mutation status in the key regions of the KRAS gene; however, several challenges remain related to standardized and uniform testing, including the selection of tumor samples, tumor sample processing and optimal testing methods. Moreover, new testing strategies, in combination with the mutation analysis of BRAF, PIK3CA and loss of PTEN proposed by many researchers and pathologists, should be promoted. In addition, we recommend that microsatellite instability, a prognostic factor, be added to the abovementioned concomitant analysis. This review provides an overview of KRAS biology and the recent advances in KRAS mutation testing. This review also addresses other aspects of status testing for determining the appropriate treatment and offers insight into the potential drawbacks of mutational testing. PMID:23066310

Using the MCF10A/MCF10CA1a Breast Cancer Progression Cell Line Model to Investigate the Effect of Active, Mutant Forms of EGFR in Breast Cancer Development and Treatment Using Gefitinib

PubMed Central

Bessette, Darrell C.; Tilch, Erik; Seidens, Tatjana; Quinn, Michael C. J.; Wiegmans, Adrian P.; Shi, Wei; Cocciardi, Sibylle; McCart-Reed, Amy; Saunus, Jodi M.; Simpson, Peter T.; Grimmond, Sean M.; Lakhani, Sunil R.; Khanna, Kum Kum; Waddell, Nic; Al-Ejeh, Fares; Chenevix-Trench, Georgia

2015-01-01

Background Basal-like and triple negative breast cancer (TNBC) share common molecular features, poor prognosis and a propensity for metastasis to the brain. Amplification of epidermal growth factor receptor (EGFR) occurs in ~50% of basal-like breast cancer, and mutations in the epidermal growth factor receptor (EGFR) have been reported in up to ~ 10% of Asian TNBC patients. In non-small cell lung cancer several different mutations in the EGFR tyrosine kinase domain confer sensitivity to receptor tyrosine kinase inhibitors, but the tumourigenic potential of EGFR mutations in breast cells and their potential for targeted therapy is unknown. Materials and Methods Constructs containing wild type, G719S or E746-A750 deletion mutant forms of EGFR were transfected into the MCF10A breast cells and their tumorigenic derivative, MCF10CA1a. The effects of EGFR over-expression and mutation on proliferation, migration, invasion, response to gefitinib, and tumour formation in vivo was investigated. Copy number analysis and whole exome sequencing of the MCF10A and MCF10CA1a cell lines were also performed. Results Mutant EGFR increased MCF10A and MCF10CA1a proliferation and MCF10A gefitinib sensitivity. The EGFR-E746-A750 deletion increased MCF10CA1a cell migration and invasion, and greatly increased MCF10CA1a xenograft tumour formation and growth. Compared to MCF10A cells, MCF10CA1a cells exhibited large regions of gain on chromosomes 3 and 9, deletion on chromosome 7, and mutations in many genes implicated in cancer. Conclusions Mutant EGFR enhances the oncogenic properties of MCF10A cell line, and increases sensitivity to gefitinib. Although the addition of EGFR E746-A750 renders the MCF10CA1a cells more tumourigenic in vivo it is not accompanied by increased gefitinib sensitivity, perhaps due to additional mutations, including the PIK3CA H1047R mutation, that the MCF10CA1a cell line has acquired. Screening TNBC/basal-like breast cancer for EGFR mutations may prove useful for directing therapy but, as in non-small cell lung cancer, accompanying mutations in PIK3CA may confer gefitinib resistance. PMID:25969993

Regulation of Embryonic and Postnatal Development by the CSF-1 Receptor

PubMed Central

Chitu, Violeta; Stanley, E. Richard

2017-01-01

Macrophages are found in all tissues and regulate tissue morphogenesis during development through trophic and scavenger functions. The colony stimulating factor-1 (CSF-1) receptor (CSF-1R) is the major regulator of tissue macrophage development and maintenance. In combination with receptor activator of nuclear factor κB (RANK), the CSF-1R also regulates the differentiation of the bone-resorbing osteoclast and controls bone remodeling during embryonic and early postnatal development. CSF-1R-regulated macrophages play trophic and remodeling roles in development. Outside the mononuclear phagocytic system, the CSF-1R directly regulates neuronal survival and differentiation, the development of intestinal Paneth cells and of preimplantation embryos, as well as trophoblast innate immune function. Consistent with the pleiotropic roles of the receptor during development, CSF-1R deficiency in most mouse strains causes embryonic or perinatal death and the surviving mice exhibit multiple developmental and functional deficits. The CSF-1R is activated by two dimeric glycoprotein ligands, CSF-1, and interleukin-34 (IL-34). Homozygous Csf1-null mutations phenocopy most of the deficits of Csf1r-null mice. In contrast, Il34-null mice have no gross phenotype, except for decreased numbers of Langerhans cells and microglia, indicating that CSF-1 plays the major developmental role. Homozygous inactivating mutations of the Csf1r or its ligands have not been reported in man. However, heterozygous inactivating mutations in the Csf1r lead to a dominantly inherited adult-onset progressive dementia, highlighting the importance of CSF-1R signaling in the brain. PMID:28236968

Regulation of Embryonic and Postnatal Development by the CSF-1 Receptor.

PubMed

Chitu, Violeta; Stanley, E Richard

2017-01-01

Macrophages are found in all tissues and regulate tissue morphogenesis during development through trophic and scavenger functions. The colony stimulating factor-1 (CSF-1) receptor (CSF-1R) is the major regulator of tissue macrophage development and maintenance. In combination with receptor activator of nuclear factor κB (RANK), the CSF-1R also regulates the differentiation of the bone-resorbing osteoclast and controls bone remodeling during embryonic and early postnatal development. CSF-1R-regulated macrophages play trophic and remodeling roles in development. Outside the mononuclear phagocytic system, the CSF-1R directly regulates neuronal survival and differentiation, the development of intestinal Paneth cells and of preimplantation embryos, as well as trophoblast innate immune function. Consistent with the pleiotropic roles of the receptor during development, CSF-1R deficiency in most mouse strains causes embryonic or perinatal death and the surviving mice exhibit multiple developmental and functional deficits. The CSF-1R is activated by two dimeric glycoprotein ligands, CSF-1, and interleukin-34 (IL-34). Homozygous Csf1-null mutations phenocopy most of the deficits of Csf1r-null mice. In contrast, Il34-null mice have no gross phenotype, except for decreased numbers of Langerhans cells and microglia, indicating that CSF-1 plays the major developmental role. Homozygous inactivating mutations of the Csf1r or its ligands have not been reported in man. However, heterozygous inactivating mutations in the Csf1r lead to a dominantly inherited adult-onset progressive dementia, highlighting the importance of CSF-1R signaling in the brain. © 2017 Elsevier Inc. All rights reserved.

An activation switch in the rhodopsin family of G protein-coupled receptors: the thyrotropin receptor.

PubMed

Urizar, Eneko; Claeysen, Sylvie; Deupí, Xavier; Govaerts, Cedric; Costagliola, Sabine; Vassart, Gilbert; Pardo, Leonardo

2005-04-29

We aimed at understanding molecular events involved in the activation of a member of the G protein-coupled receptor family, the thyrotropin receptor. We have focused on the transmembrane region and in particular on a network of polar interactions between highly conserved residues. Using molecular dynamics simulations and site-directed mutagenesis techniques we have identified residue Asn-7.49, of the NPxxY motif of TM 7, as a molecular switch in the mechanism of thyrotropin receptor (TSHr) activation. Asn-7.49 appears to adopt two different conformations in the inactive and active states. These two states are characterized by specific interactions between this Asn and polar residues in the transmembrane domain. The inactive gauche+ conformation is maintained by interactions with residues Thr-6.43 and Asp-6.44. Mutation of these residues into Ala increases the constitutive activity of the receptor by factors of approximately 14 and approximately 10 relative to wild type TSHr, respectively. Upon receptor activation Asn-7.49 adopts the trans conformation to interact with Asp-2.50 and a putatively charged residue that remains to be identified. In addition, the conserved Leu-2.46 of the (N/S)LxxxD motif also plays a significant role in restraining the receptor in the inactive state because the L2.46A mutation increases constitutive activity by a factor of approximately 13 relative to wild type TSHr. As residues Leu-2.46, Asp-2.50, and Asn-7.49 are strongly conserved, this molecular mechanism of TSHr activation can be extended to other members of the rhodopsin-like family of G protein-coupled receptors.

Epidermal growth factor receptor T790M mutation-positive metastatic non-small-cell lung cancer: focus on osimertinib (AZD9291)

PubMed Central

Saad, Nibal; Poudel, Aarati; Basnet, Alina; Gajra, Ajeet

2017-01-01

Adenocarcinoma is the most common type of non-small-cell lung cancer (NSCLC). Adenocarcinoma with epidermal growth factor receptor (EGFR) mutations accounts for 8%–30% of all cases of NSCLC depending on the geography and ethnicity. EGFR-mutated NSCLC usually responds to first-line therapy with EGFR tyrosine kinase inhibitors (TKIs). However, there is eventual loss of efficacy to TKIs due to development of resistance. The most frequent cause for resistance is a second EGFR mutation in exon 20 (T790M), which is encountered in up to 62% of patients. Osimertinib is one of the third-generation EGFR TKIs with a high selective potency against T790M mutants. In Phase I trial of osimertinib in advanced lung cancer after progression on EGFR TKIs, the response rate and disease control rate were 61% and 95%, respectively. A subsequent Phase II (AURA2) trial demonstrated a disease control rate of 92%, a response rate of 71%, a median duration of response of 7.8 months, and a median progression-free survival of 8.6 months. Osimertinib was approved by the US Food & Drug Administration in November 2015 for patients whose tumors exhibited T790M mutation and for those with progressive disease on other EGFR TKIs. In this review, we address the role of EGFR TKIs in the management of EGFR mutation lung cancer and the mechanisms of resistance to TKIs with a focus on the role of osimertinib. Data from completed trials of osimertinib, ongoing trials, as well as novel diagnostic methods to detect EGFR T790M mutation are reviewed. PMID:28367058

Epidermal growth factor receptor T790M mutation-positive metastatic non-small-cell lung cancer: focus on osimertinib (AZD9291).

PubMed

Saad, Nibal; Poudel, Aarati; Basnet, Alina; Gajra, Ajeet

2017-01-01

Adenocarcinoma is the most common type of non-small-cell lung cancer (NSCLC). Adenocarcinoma with epidermal growth factor receptor (EGFR) mutations accounts for 8%-30% of all cases of NSCLC depending on the geography and ethnicity. EGFR-mutated NSCLC usually responds to first-line therapy with EGFR tyrosine kinase inhibitors (TKIs). However, there is eventual loss of efficacy to TKIs due to development of resistance. The most frequent cause for resistance is a second EGFR mutation in exon 20 (T790M), which is encountered in up to 62% of patients. Osimertinib is one of the third-generation EGFR TKIs with a high selective potency against T790M mutants. In Phase I trial of osimertinib in advanced lung cancer after progression on EGFR TKIs, the response rate and disease control rate were 61% and 95%, respectively. A subsequent Phase II (AURA2) trial demonstrated a disease control rate of 92%, a response rate of 71%, a median duration of response of 7.8 months, and a median progression-free survival of 8.6 months. Osimertinib was approved by the US Food & Drug Administration in November 2015 for patients whose tumors exhibited T790M mutation and for those with progressive disease on other EGFR TKIs. In this review, we address the role of EGFR TKIs in the management of EGFR mutation lung cancer and the mechanisms of resistance to TKIs with a focus on the role of osimertinib. Data from completed trials of osimertinib, ongoing trials, as well as novel diagnostic methods to detect EGFR T790M mutation are reviewed.

Two novel mutations of fibrillin-1 gene correlate with different phenotypes of Marfan syndrome in Chinese families.

PubMed

Zhao, Feng; Pan, Xinyuan; Zhao, Kanxing; Zhao, Chen

2013-01-01

To identify the causative mutations in two Chinese families with autosomal dominant Marfan syndrome and to describe the associated phenotypes. Complete physical, ophthalmic, and cardiovascular examinations were given to the patients and unaffected individuals in the two families. Exclusive linkage mapping was performed for transforming growth factor beta receptor II (TGFBR2) and fibrillin-1 (FBN1) loci in both families. The entire coding region and flanking splice sites of the FBN1 gene were screened for mutations in the two families with Sanger sequencing. The potential mutations of FBN1 were tested in 100 normal controls. Lens dislocation was observed in two out of ten patients in the MF1 family and all patients in the MF2 family. However, the MF1 family displayed more severe cardiovascular and skeletal system involvement compared with the MF2 family. The transforming growth factor beta receptor II locus was excluded in both families by linkage analysis. A maximum multipoint lod score score of 2.83 was obtained for marker D15S992 (located in the FBN1 gene) in the MF1 family and 1.51 for the same marker in the MF2 family. Two novel mutations of FBN1, p.C271* and p.C637Y, were identified in the MF1 and MF2 families, respectively. Genotype-phenotype correlations in this study indicate that nonsense mutations of FBN1 may correlate with relatively severe systemic phenotypes when compared with cysteine substitutions, the most common type of FBN1 mutations. Genetic diagnosis for patients with Marfan syndrome would help with genetic counseling, clinical intervention, and prognosis.

Two novel mutations of fibrillin-1 gene correlate with different phenotypes of Marfan syndrome in Chinese families

PubMed Central

Zhao, Feng; Pan, Xinyuan; Zhao, Kanxing

2013-01-01

Purpose To identify the causative mutations in two Chinese families with autosomal dominant Marfan syndrome and to describe the associated phenotypes. Methods Complete physical, ophthalmic, and cardiovascular examinations were given to the patients and unaffected individuals in the two families. Exclusive linkage mapping was performed for transforming growth factor beta receptor II (TGFBR2) and fibrillin-1 (FBN1) loci in both families. The entire coding region and flanking splice sites of the FBN1 gene were screened for mutations in the two families with Sanger sequencing. The potential mutations of FBN1 were tested in 100 normal controls. Results Lens dislocation was observed in two out of ten patients in the MF1 family and all patients in the MF2 family. However, the MF1 family displayed more severe cardiovascular and skeletal system involvement compared with the MF2 family. The transforming growth factor beta receptor II locus was excluded in both families by linkage analysis. A maximum multipoint lod score score of 2.83 was obtained for marker D15S992 (located in the FBN1 gene) in the MF1 family and 1.51 for the same marker in the MF2 family. Two novel mutations of FBN1, p.C271* and p.C637Y, were identified in the MF1 and MF2 families, respectively. Conclusions Genotype-phenotype correlations in this study indicate that nonsense mutations of FBN1 may correlate with relatively severe systemic phenotypes when compared with cysteine substitutions, the most common type of FBN1 mutations. Genetic diagnosis for patients with Marfan syndrome would help with genetic counseling, clinical intervention, and prognosis. PMID:23592911

Somatic profiling of the epidermal growth factor receptor pathway in tumours from patients with advanced colorectal cancer, treated with chemotherapy ± cetuximab

PubMed Central

Smith, Christopher G.; Fisher, David; Claes, Bart; Maughan, Timothy S.; Idziaszczyk, Shelley; Peuteman, Gilian; Harris, Rebecca; James, Michelle D.; Meade, Angela; Jasani, Bharat; Adams, Richard A.; Kenny, Sarah; Kaplan, Richard; Lambrechts, Diether; Cheadle, Jeremy P.

2013-01-01

Purpose To study the somatic molecular profile of the epidermal growth factor receptor (EGFR) pathway in advanced CRC (aCRC), its relationship to prognosis, the site of the primary and metastases, and response to cetuximab. Experimental Design We used Sequenom and Pyrosequencing for high-throughput somatic profiling the EGFR pathway in 1,976 tumours from patients with aCRC from the COIN trial (oxaliplatin and fluoropyrimidine chemotherapy ±cetuximab). Correlations between mutations, clinico-pathological, response and survival data were carried out. Results Sequenom and Pyrosequencing had 99.0% (9961/10063) genotype concordance. We identified thirteen different KRAS mutations in 42.3% of aCRCs, two BRAF mutations in 9.0%, four NRAS mutations in 3.6% and five PIK3CA mutations in 12.7%. 4.2% of aCRCs had microsatellite instability (MSI). KRAS and PIK3CA exon 9, but not exon 20, mutations co-occurred (P=8.9×10−4) as did MSI and BRAF mutations (P=5.3×10−10). KRAS mutations were associated with right colon cancers (P=5.2×10−5) and BRAF mutations with right (P=7.2×10−5) and transverse colon (P=9.8×10−6) cancers. KRAS mutations were associated with lung-only metastases (P=2.3×10−4), BRAF mutations with peritoneal (P=9.2×10−4) and nodal-only (P=3.7×10−5) metastases, and MSI (BRAFWT) with nodal-only metastases (P=2.9×10−4). MSI (BRAFWT) was associated with worse survival (HR=1.89, 95% CI 1.30-2.76, P=8.5×10−4). No mutations, subsets of mutations, or MSI-status were associated with response to cetuximab. Conclusions Our data support a functional co-operation between KRAS and PIK3CA in colorectal tumourigenesis and link somatic profiles to the sites of metastases. MSI was associated with poor prognosis in advanced disease, and no individual somatic profile was associated with response to cetuximab in COIN. PMID:23741067

Guide to detecting epidermal growth factor receptor (EGFR) mutations in ctDNA of patients with advanced non-small-cell lung cancer

PubMed Central

Normanno, Nicola; Denis, Marc G.; Thress, Kenneth S.; Ratcliffe, Marianne; Reck, Martin

2017-01-01

Cancer treatment is evolving towards therapies targeted at specific molecular abnormalities that drive tumor growth. Consequently, to determine which patients are eligible, accurate assessment of molecular aberrations within tumors is required. Obtaining sufficient tumor tissue for molecular testing can present challenges; therefore, circulating free tumor-derived DNA (ctDNA) found in blood plasma has been proposed as an alternative source of tumor DNA. The diagnostic utility of ctDNA for the detection of epidermal growth factor receptor (EGFR) mutations harbored in tumors of patients with advanced non-small-cell lung cancer (NSCLC) is supported by the results of several large studies/meta-analyses. However, recent real-world studies suggest that the performance of ctDNA testing varies between geographic regions/laboratories, demonstrating the need for standardized guidance. In this review, we outline recommendations for obtaining an accurate result using ctDNA, relating to pre-analytical plasma processing, ctDNA extraction, and appropriate EGFR mutation detection methods, based on clinical trial results. We conclude that there are several advantages associated with ctDNA, including the potential for repeated sampling particularly following progression after first-line tyrosine kinase inhibitor (TKI) therapy, as TKIs targeting resistance mutations (eg T790M) are now approved for use in the USA/EU/Japan (at time of writing). However, evidence suggests that ctDNA does not allow detection of EGFR mutations in all patients with known mutation-positive NSCLC. Therefore, although tumor tissue should be the first sample choice for EGFR testing at diagnosis, ctDNA is a promising alternative diagnostic approach. PMID:27980215

Differential manipulation of arrestin-3 binding to basal and agonist-activated G protein-coupled receptors.

PubMed

Prokop, Susanne; Perry, Nicole A; Vishnivetskiy, Sergey A; Toth, Andras D; Inoue, Asuka; Milligan, Graeme; Iverson, Tina M; Hunyady, Laszlo; Gurevich, Vsevolod V

2017-08-01

Non-visual arrestins interact with hundreds of different G protein-coupled receptors (GPCRs). Here we show that by introducing mutations into elements that directly bind receptors, the specificity of arrestin-3 can be altered. Several mutations in the two parts of the central "crest" of the arrestin molecule, middle-loop and C-loop, enhanced or reduced arrestin-3 interactions with several GPCRs in receptor subtype and functional state-specific manner. For example, the Lys139Ile substitution in the middle-loop dramatically enhanced the binding to inactive M 2 muscarinic receptor, so that agonist activation of the M 2 did not further increase arrestin-3 binding. Thus, the Lys139Ile mutation made arrestin-3 essentially an activation-independent binding partner of M 2 , whereas its interactions with other receptors, including the β 2 -adrenergic receptor and the D 1 and D 2 dopamine receptors, retained normal activation dependence. In contrast, the Ala248Val mutation enhanced agonist-induced arrestin-3 binding to the β 2 -adrenergic and D 2 dopamine receptors, while reducing its interaction with the D 1 dopamine receptor. These mutations represent the first example of altering arrestin specificity via enhancement of the arrestin-receptor interactions rather than selective reduction of the binding to certain subtypes. Copyright © 2017. Published by Elsevier Inc.

Ionotropic GABA and Glutamate Receptor Mutations and Human Neurologic Diseases.

PubMed

Yuan, Hongjie; Low, Chian-Ming; Moody, Olivia A; Jenkins, Andrew; Traynelis, Stephen F

2015-07-01

The advent of whole exome/genome sequencing and the technology-driven reduction in the cost of next-generation sequencing as well as the introduction of diagnostic-targeted sequencing chips have resulted in an unprecedented volume of data directly linking patient genomic variability to disorders of the brain. This information has the potential to transform our understanding of neurologic disorders by improving diagnoses, illuminating the molecular heterogeneity underlying diseases, and identifying new targets for therapeutic treatment. There is a strong history of mutations in GABA receptor genes being involved in neurologic diseases, particularly the epilepsies. In addition, a substantial number of variants and mutations have been found in GABA receptor genes in patients with autism, schizophrenia, and addiction, suggesting potential links between the GABA receptors and these conditions. A new and unexpected outcome from sequencing efforts has been the surprising number of mutations found in glutamate receptor subunits, with the GRIN2A gene encoding the GluN2A N-methyl-d-aspartate receptor subunit being most often affected. These mutations are associated with multiple neurologic conditions, for which seizure disorders comprise the largest group. The GluN2A subunit appears to be a locus for epilepsy, which holds important therapeutic implications. Virtually all α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor mutations, most of which occur within GRIA3, are from patients with intellectual disabilities, suggesting a link to this condition. Similarly, the most common phenotype for kainate receptor variants is intellectual disability. Herein, we summarize the current understanding of disease-associated mutations in ionotropic GABA and glutamate receptor families, and discuss implications regarding the identification of human mutations and treatment of neurologic diseases. Copyright © 2015 by The American Society for Pharmacology and Experimental Therapeutics.

Ionotropic GABA and Glutamate Receptor Mutations and Human Neurologic Diseases

PubMed Central

Yuan, Hongjie; Low, Chian-Ming; Moody, Olivia A.; Jenkins, Andrew

2015-01-01

The advent of whole exome/genome sequencing and the technology-driven reduction in the cost of next-generation sequencing as well as the introduction of diagnostic-targeted sequencing chips have resulted in an unprecedented volume of data directly linking patient genomic variability to disorders of the brain. This information has the potential to transform our understanding of neurologic disorders by improving diagnoses, illuminating the molecular heterogeneity underlying diseases, and identifying new targets for therapeutic treatment. There is a strong history of mutations in GABA receptor genes being involved in neurologic diseases, particularly the epilepsies. In addition, a substantial number of variants and mutations have been found in GABA receptor genes in patients with autism, schizophrenia, and addiction, suggesting potential links between the GABA receptors and these conditions. A new and unexpected outcome from sequencing efforts has been the surprising number of mutations found in glutamate receptor subunits, with the GRIN2A gene encoding the GluN2A N-methyl-d-aspartate receptor subunit being most often affected. These mutations are associated with multiple neurologic conditions, for which seizure disorders comprise the largest group. The GluN2A subunit appears to be a locus for epilepsy, which holds important therapeutic implications. Virtually all α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor mutations, most of which occur within GRIA3, are from patients with intellectual disabilities, suggesting a link to this condition. Similarly, the most common phenotype for kainate receptor variants is intellectual disability. Herein, we summarize the current understanding of disease-associated mutations in ionotropic GABA and glutamate receptor families, and discuss implications regarding the identification of human mutations and treatment of neurologic diseases. PMID:25904555

Gene editing rescue of a novel MPL mutant associated with congenital amegakaryocytic thrombocytopenia.

PubMed

Cleyrat, Cédric; Girard, Romain; Choi, Eun H; Jeziorski, Éric; Lavabre-Bertrand, Thierry; Hermouet, Sylvie; Carillo, Serge; Wilson, Bridget S

2017-09-26

Thrombopoietin (Tpo) and its receptor (Mpl) are the principal regulators of early and late thrombopoiesis and hematopoietic stem cell maintenance. Mutations in MPL can drastically impair its function and be a contributing factor in multiple hematologic malignancies, including congenital amegakaryocytic thrombocytopenia (CAMT). CAMT is characterized by severe thrombocytopenia at birth, which progresses to bone marrow failure and pancytopenia. Here we report unique familial cases of CAMT that presented with a previously unreported MPL mutation: T814C (W272R) in the background of the activating MPL G117T (K39N or Baltimore) mutation. Confocal microscopy, proliferation and surface biotinylation assays, co-immunoprecipitation, and western blotting analysis were used to elucidate the function and trafficking of Mpl mutants. Results showed that Mpl protein bearing the W272R mutation, alone or together with the K39N mutation, lacks detectable surface expression while being strongly colocalized with the endoplasmic reticulum (ER) marker calreticulin. Both WT and K39N-mutated Mpl were found to be signaling competent, but single or double mutants bearing W272R were unresponsive to Tpo. Function of the deficient Mpl receptor could be rescued by using 2 separate approaches: (1) GRASP55 overexpression, which partially restored Tpo-induced signaling of mutant Mpl by activating an autophagy-dependent secretory pathway and thus forcing ER-trapped immature receptors to traffic to the cell surface; and (2) CRISPR-Cas9 gene editing used to repair MPL T814C mutation in transfected cell lines and primary umbilical cord blood-derived CD34 + cells. We demonstrate proof of principle for rescue of mutant Mpl function by using gene editing of primary hematopoietic stem cells, which indicates direct therapeutic applications for CAMT patients.

Gene editing rescue of a novel MPL mutant associated with congenital amegakaryocytic thrombocytopenia

PubMed Central

Girard, Romain; Choi, Eun H.; Jeziorski, Éric; Lavabre-Bertrand, Thierry; Hermouet, Sylvie; Carillo, Serge; Wilson, Bridget S.

2017-01-01

Thrombopoietin (Tpo) and its receptor (Mpl) are the principal regulators of early and late thrombopoiesis and hematopoietic stem cell maintenance. Mutations in MPL can drastically impair its function and be a contributing factor in multiple hematologic malignancies, including congenital amegakaryocytic thrombocytopenia (CAMT). CAMT is characterized by severe thrombocytopenia at birth, which progresses to bone marrow failure and pancytopenia. Here we report unique familial cases of CAMT that presented with a previously unreported MPL mutation: T814C (W272R) in the background of the activating MPL G117T (K39N or Baltimore) mutation. Confocal microscopy, proliferation and surface biotinylation assays, co-immunoprecipitation, and western blotting analysis were used to elucidate the function and trafficking of Mpl mutants. Results showed that Mpl protein bearing the W272R mutation, alone or together with the K39N mutation, lacks detectable surface expression while being strongly colocalized with the endoplasmic reticulum (ER) marker calreticulin. Both WT and K39N-mutated Mpl were found to be signaling competent, but single or double mutants bearing W272R were unresponsive to Tpo. Function of the deficient Mpl receptor could be rescued by using 2 separate approaches: (1) GRASP55 overexpression, which partially restored Tpo-induced signaling of mutant Mpl by activating an autophagy-dependent secretory pathway and thus forcing ER-trapped immature receptors to traffic to the cell surface; and (2) CRISPR-Cas9 gene editing used to repair MPL T814C mutation in transfected cell lines and primary umbilical cord blood–derived CD34+ cells. We demonstrate proof of principle for rescue of mutant Mpl function by using gene editing of primary hematopoietic stem cells, which indicates direct therapeutic applications for CAMT patients. PMID:29296828

[Evaluation of Consistency in detection of epidermal growth factor receptor gene T790M mutation in plasma and tumor specimens of patients with lung adenocarcinoma].

PubMed

Du, J; Wang, Z; Yang, L; Di, J; Zhang, J G; Wang, T Y; Liu, D G

2018-01-23

Objective: To evaluate the consistency in detection of T790M mutation of epidermal growth factor receptor gene (EGFR) in plasma and tumor samples of patients with lung adenocarcinoma. Methods: The tumor tissues or cytological specimens of 12 patients with operable lung adenocarcinoma(stage Ⅰ-ⅢA) and 100 patients with advanced stage ⅢB-Ⅳ lung adenocarcinoma were collected, among which 11 patients showed acquired resistance for gefitinib (11/100). In the same period, peripheral blood samples were collected from all patients and 50 healthy volunteers. Amplification refractory mutation system (ARMS) was used to detect EGFR mutations in tumor specimens. Next Generation Sequencing(NGS) based circulating single-molecule amplification and resequencing technology (cSMART)was performed to quantitatively detect the EGFR mutations in circulating tumor DNA (ctDNA) from plasma specimens. Results: The sensitivity, specificity and concordance rate of EGFR T790M mutation between plasma and tissue specimens from 100 advanced stage patients were 50.0%, 72.9% and 72.0%, respectively. For L858R mutation and exon 19 deletion mutations, the above mentioned sensitivity, specificity and concordance rate were 91.7%, 100.0%, and 98.0%, as well as 79.2%, 100.0% and 95.0%, respectively. The L858R mutation and exon 19 deletion mutations were not detected in plasma of 50 healthy volunteers, whereasT790M mutation(1.0±0.0 copies) was found in 7 individuals(7/50, 14.0%). Similarly, in 12 resectable patients, 4 (4/12, 33.3%) T790M mutations were found in plasma (1.2±0.2 copies), but no L858R mutation and 19 exon deletion mutations. In comparison, 28.0% of patients with advanced lung adenocarcinoma (28/100)had detectable T790M mutation in plasma with copy numbers (34.0±22.7 copies). Furthermore, the copy numbers of T790M were 268.2±119.9 in plasma of 5 cases with acquired gefitinib-resistance. Conclusions: In patients with advanced stages of lung adenocarcinoma, the detection of T790M mutation in plasma and tumor specimens is low. The T790M mutation also exists in the plasma of some healthy controls, suggesting that T790M mutation participates in EGFR signaling pathway and it might function in healthy population.

Role of ERRF, a Novel ER-Related Nuclear Factor, in the Growth Control of ER-Positive Human Breast Cancer Cells

PubMed Central

Su, Dan; Fu, Xiaoying; Fan, Songqing; Wu, Xiao; Wang, Xin-Xin; Fu, Liya; Dong, Xue-Yuan; Ni, Jianping Jenny; Fu, Li; Zhu, Zhengmao; Dong, Jin-Tang

2012-01-01

Whereas estrogen–estrogen receptor α (ER) signaling plays an important role in breast cancer growth, it is also necessary for the differentiation of normal breast epithelial cells. How this functional conversion occurs, however, remains unknown. Based on a genome-wide sequencing study that identified mutations in several breast cancer genes, we examined some of the genes for mutations, expression levels, and functional effects on cell proliferation and tumorigenesis. We present the data for C1orf64 or ER-related factor (ERRF) from 31 cell lines and 367 primary breast cancer tumors. Whereas mutation of ERRF was infrequent (1 of 79 or 1.3%), its expression was up-regulated in breast cancer, and the up-regulation was more common in lower-stage tumors. In addition, increased ERRF expression was significantly associated with ER and/or progesterone receptor (PR) positivity, which was still valid in human epidermal growth factor receptor 2 (HER2)–negative tumors. In ER-positive tumors, ERRF expression was inversely correlated with HER2 status. Furthermore, higher ERRF protein expression was significantly associated with better disease-free survival and overall survival, particularly in ER- and/or PR-positive and HER2-negative tumors (luminal A subtype). Functionally, knockdown of ERRF in two ER-positive breast cancer cell lines, T-47D and MDA-MB-361, suppressed cell growth in vitro and tumorigenesis in xenograft models. These results suggest that ERRF plays a role in estrogen-ER–mediated growth of breast cancer cells and could, thus, be a potential therapeutic target. PMID:22341523

Value of combining serum carcinoembryonic antigen and PET/CT in predicting EGFR mutation in non-small cell lung cancer.

PubMed

Gu, Jincui; Xu, Siqi; Huang, Lixia; Li, Shaoli; Wu, Jian; Xu, Junwen; Feng, Jinlun; Liu, Baomo; Zhou, Yanbin

2018-02-01

We sought to investigate the associations between pretreatment serum Carcinoembryonic antigen (CEA) level, 18 F-Fluoro-2-deoxyglucose ( 18 F-FDG) uptake value of primary tumor and epidermal growth factor receptor ( EGFR ) mutation status in non-small cell lung cancer (NSCLC). We retrospectively reviewed medical records of 210 NSCLC patients who underwent EGFR mutation test and 18 F-FDG positron emission tomography/computed tomography (PET/CT) scan before anti-tumor therapy. The associations between EGFR mutations and patients' characteristics, serum CEA, PET/CT imaging characteristics maximal standard uptake value (SUVmax) of the primary tumor were analyzed. Receiver-operating characteristic (ROC) curve was used to assess the predictive value of these factors. EGFR mutations were found in 70 patients (33.3%). EGFR mutations were more common in high CEA group (CEA ≥7.0 ng/mL) than in low CEA group (CEA <7.0 ng/mL) (40.4% vs . 27.6%; P=0.05). Females (P<0.001), non-smokers (P<0.001), patients with adenocarcinoma (P<0.001) and SUVmax <9.0 (P=0.001) were more likely to be EGFR mutation-positive. Multivariate analysis revealed that gender, tumor histology, pretreatment serum CEA level, and SUVmax were the most significant predictors for EGFR mutations. The ROC curve revealed that combining these four factors yielded a higher calculated AUC (0.80). Gender, histology, pretreatment serum CEA level and SUVmax are significant predictors for EGFR mutations in NSCLC. Combining these factors in predicting EGFR mutations has a moderate diagnostic accuracy, and is helpful in guiding anti-tumor treatment.

Generation of herpesvirus entry mediator (HVEM)-restricted herpes simplex virus type 1 mutant viruses: resistance of HVEM-expressing cells and identification of mutations that rescue nectin-1 recognition.

PubMed

Uchida, Hiroaki; Shah, Waris A; Ozuer, Ali; Frampton, Arthur R; Goins, William F; Grandi, Paola; Cohen, Justus B; Glorioso, Joseph C

2009-04-01

Both initial infection and cell-to-cell spread by herpes simplex virus type 1 (HSV-1) require the interaction of the viral glycoprotein D (gD) with an entry receptor on the cell surface. The two major HSV entry receptors, herpesvirus entry mediator (HVEM) and nectin-1, mediate infection independently but are coexpressed on a variety of cells. To determine if both receptors are active in these instances, we have established mutant viruses that are selectively impaired for recognition of one or the other receptor. In plaque assays, these viruses showed approximately 1,000-fold selectivity for the matched receptor over the mismatched receptor. Separate assays showed that each virus is impaired for both infection and spread through the mismatched receptor. We tested several human tumor cell lines for susceptibility to these viruses and observed that HT29 colon carcinoma cells are susceptible to infection by nectin-1-restricted virus but are highly resistant to HVEM-restricted virus infection, despite readily detectable HVEM expression on the cell surface. HVEM cDNA isolated from HT29 cells rendered HSV-resistant cells permissive for infection by the HVEM-restricted virus, suggesting that HT29 cells lack a cofactor for HVEM-mediated infection or express an HVEM-specific inhibitory factor. Passaging of HVEM-restricted virus on nectin-1-expressing cells yielded a set of gD missense mutations that each restored functional recognition of nectin-1. These mutations identify residues that likely play a role in shaping the nectin-1 binding site of gD. Our findings illustrate the utility of these receptor-restricted viruses in studying the early events in HSV infection.

A novel point mutation of the human glucocorticoid receptor gene causes primary generalized glucocorticoid resistance through impaired interaction with the LXXLL motif of the p160 coactivators: dissociation of the transactivating and transreppressive activities.

PubMed

Nicolaides, Nicolas C; Roberts, Michael L; Kino, Tomoshige; Braatvedt, Geoffrey; Hurt, Darrell E; Katsantoni, Eleni; Sertedaki, Amalia; Chrousos, George P; Charmandari, Evangelia

2014-05-01

Primary generalized glucocorticoid resistance is a rare genetic disorder characterized by generalized, partial, target-tissue insensitivity to glucocorticoids. The molecular basis of the condition has been ascribed to inactivating mutations in the human glucocorticoid receptor (hGR) gene. The objective of the study was to present three new cases caused by a novel mutation in the hGR gene and to delineate the molecular mechanisms through which the mutant receptor impairs glucocorticoid signal transduction. The index case (father) and his two daughters presented with increased urinary free cortisol excretion and resistance of the hypothalamic-pituitary-adrenal axis to dexamethasone suppression in the absence of clinical manifestations suggestive of Cushing syndrome. All subjects harbored a novel, heterozygous, point mutation (T→G) at nucleotide position 1724 of the hGR gene, which resulted in substitution of valine by glycine at amino acid 575 of the receptor. Compared with the wild-type receptor, the hGRαV575G demonstrated a significant (33%) reduction in its ability to transactivate the mouse mammary tumor virus promoter in response to dexamethasone, a 50% decrease in its affinity for the ligand, and a 2.5-fold delay in nuclear translocation. Although it did not exert a dominant negative effect on the wild-type receptor and preserved its ability to bind to DNA, hGRαV575G displayed significantly enhanced (∼80%) ability to transrepress the nuclear factor-κΒ signaling pathway. Finally, the mutant receptor hGRαV575G demonstrated impaired interaction with the LXXLL motif of the glucocorticoid receptor-interacting protein 1 coactivator in vitro and in computer-based structural simulation via its defective activation function-2 (AF-2) domain. The natural mutant receptor hGRαV575G causes primary generalized glucocorticoid resistance by affecting multiple steps in the glucocorticoid signaling cascade, including the affinity for the ligand, the time required for nuclear translocation, and the interaction with the glucocorticoid-interacting protein-1 coactivator.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) associated with a novel C82R mutation in the NOTCH3 gene.

PubMed

Zea-Sevilla, M Ascensión; Bermejo-Velasco, Pedro; Serrano-Heranz, Regino; Calero, Miguel

2015-01-01

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a rare inherited cerebrovascular disease associated with mutations in the NOTCH3 gene on chromosome 19, and represents the most common hereditary stroke disorder. We describe a pedigree, which suffered the classical clinical CADASIL pattern of migraine headaches, recurrent subcortical infarcts, and subcortical dementia, associated with a previously undescribed missense mutation (c.[244T>C], p.[C82R]) in NOTCH3. This new mutation extends the list of known pathogenic mutations responsible for CADASIL, which are associated with an odd number of cysteine residues within any of the epidermal growth factor-like repeats of Notch3 receptor protein.

Inhibiting the Epidermal Growth Factor Receptor | Center for Cancer Research

Cancer.gov

The Epidermal Growth Factor Receptor (EGFR) is a widely distributed cell surface receptor that responds to several extracellular signaling molecules through an intracellular tyrosine kinase, which phosphorylates target enzymes to trigger a downstream molecular cascade. Since the discovery that EGFR mutations and amplifications are critical in a number of cancers, efforts have been under way to develop and use targeted EGFR inhibitors. These efforts have met with some spectacular successes, but many patients have not responded as expected, have subsequently developed drug-resistant tumors, or have suffered serious side effects from the therapies to date. CCR Investigators are studying EGFR from multiple vantage points with the goal of developing even better strategies to defeat EGFR-related cancers.

Conformational Changes in the Capsid of a Calicivirus upon Interaction with Its Functional Receptor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ossiboff, Robert J.; Zhou, Yi; Lightfoot, Patrick J.

2010-07-19

Nonenveloped viral capsids are metastable structures that undergo conformational changes during virus entry that lead to interactions of the capsid or capsid fragments with the cell membrane. For members of the Caliciviridae, neither the nature of these structural changes in the capsid nor the factor(s) responsible for inducing these changes is known. Feline functional adhesion molecule A (fJAM-A) mediates the attachment and infectious viral entry of feline calicivirus (FCV). Here, we show that the infectivity of some FCV isolates is neutralized following incubation with the soluble receptor at 37 C. We used this property to select mutants resistant to preincubationmore » with the soluble receptor. We isolated and sequenced 24 soluble receptor-resistant (srr) mutants and characterized the growth properties and receptor-binding activities of eight mutants. The location of the mutations within the capsid structure of FCV was mapped using a new 3.6-{angstrom} structure of native FCV. The srr mutations mapped to the surface of the P2 domain were buried at the protruding domain dimer interface or were present in inaccessible regions of the capsid protein. Coupled with data showing that both the parental FCV and the srr mutants underwent increases in hydrophobicity upon incubation with the soluble receptor at 37 C, these findings indicate that FCV likely undergoes conformational change upon interaction with its receptor. Changes in FCV capsid conformation following its interaction with fJAM-A may be important for subsequent interactions of the capsid with cellular membranes, membrane penetration, and genome delivery.« less

The kinase activity of fibroblast growth factor receptor 3 with activation loop mutations affects receptor trafficking and signaling.

PubMed

Lievens, Patricia M-J; Mutinelli, Chiara; Baynes, Darcie; Liboi, Elio

2004-10-08

Amino acid substitutions at the Lys-650 codon within the activation loop kinase domain of fibroblast growth factor receptor 3 (FGFR3) result in graded constitutive phosphorylation of the receptor. Accordingly, the Lys-650 mutants are associated with dwarfisms with graded clinical severity. To assess the importance of the phosphorylation level on FGFR3 maturation along the secretory pathway, hemagglutinin A-tagged derivatives were studied. The highly activated SADDAN (severe achondroplasia with developmental delay and acanthosis nigricans) mutant accumulates in its immature and phosphorylated form in the endoplasmic reticulum (ER), which fails to be degraded. Furthermore, the Janus kinase (Jak)/STAT pathway is activated from the ER by direct recruitment of Jak1. Abolishing the autocatalytic property of the mutated FGFR3 by replacing the critical Tyr-718 reestablishes the receptor full maturation and inhibits signaling. Differently, the low activated hypochondroplasia mutant is present as a mature phosphorylated form on the plasma membrane, although with a delayed transition in the ER, and is completely processed. Signaling does not occur in the presence of brefeldin A; instead, STAT1 is activated when protein secretion is blocked with monensin, suggesting that the hypochondroplasia receptor signals at the exit from the ER. Our results suggest that kinase activity affects FGFR3 trafficking and determines the spatial segregation of signaling pathways. Consequently, the defect in down-regulation of the highly activated receptors results in the increased signaling capacity from the intracellular compartments, and this may determine the severity of the diseases.

Acquired resistance mechanisms to tyrosine kinase inhibitors in lung cancer with activating epidermal growth factor receptor mutation--diversity, ductility, and destiny.

PubMed

Suda, Kenichi; Mizuuchi, Hiroshi; Maehara, Yoshihiko; Mitsudomi, Tetsuya

2012-12-01

Lung cancers that harbor somatic activating mutations in the gene for the epidermal growth factor receptor (EGFR) depend on mutant EGFR for their proliferation and survival; therefore, lung cancer patients with EGFR mutations often dramatically respond to orally available EGFR tyrosine kinase inhibitors (TKIs). However, emergence of acquired resistance is virtually inevitable, thus limiting improvement in patient outcomes. To elucidate and overcome this acquired resistance, multidisciplinary basic and clinical investigational approaches have been applied, using in vitro cell line models or samples obtained from lung cancer patients treated with EGFR-TKIs. These efforts have revealed several acquired resistance mechanisms and candidates, including EGFR secondary mutations (T790M and other rare mutations), MET amplification, PTEN downregulation, CRKL amplification, high-level HGF expression, FAS-NFκB pathway activation, epithelial-mesenchymal transition, and conversion to small cell lung cancer. Interestingly, cancer cells harbor potential destiny and ductility together in acquiring resistance to EGFR-TKIs, as shown in in vitro acquired resistance models. Molecular mechanisms of "reversible EGFR-TKI tolerance" that occur in early phase EGFR-TKI exposure have been identified in cell line models. Furthermore, others have reported molecular markers that can predict response to EGFR-TKIs in clinical settings. Deeper understanding of acquired resistance mechanisms to EGFR-TKIs, followed by the development of molecular target drugs that can overcome the resistance, might turn this fatal disease into a chronic disorder.

Novel splice site mutation in the growth hormone receptor gene in Turkish patients with Laron-type dwarfism.

PubMed

Arman, Ahmet; Ozon, Alev; Isguven, Pinar S; Coker, Ajda; Peker, Ismail; Yordam, Nursen

2008-01-01

Growth hormone (GH) is involved in growth, and fat and carbohydrate metabolism. Interaction of GH with the GH receptor (GHR) is necessary for systemic and local production of insulin-like growth factor-I (IGF-I) which mediates GH actions. Mutations in the GHR cause severe postnatal growth failure; the disorder is an autosomal recessive genetic disease resulting in GH insensitivity, called Laron syndrome. It is characterized by dwarfism with elevated serum GH and low levels of IGF-I. We analyzed the GHR gene for mutations and polymorphisms in eight patients with Laron-type dwarfism from six families. We found three missense mutations (S40L, V125A, I526L), one nonsense mutation (W157X), and one splice site mutation in the extracellular domain of GHR. Furthermore, G168G and exon 3 deletion polymorphisms were detected in patients with Laron syndrome. The splice site mutation, which is a novel mutation, was located at the donor splice site of exon 2/ intron 2 within GHR. Although this mutation changed the highly conserved donor splice site consensus sequence GT to GGT by insertion of a G residue, the intron splicing between exon 2 and exon 3 was detected in the patient. These results imply that the splicing occurs arthe GT site in intron 2, leaving the extra inserted G residue at the end of exon 2, thus changing the open reading frame of GHR resulting in a premature termination codon in exon 3.

Residues W320 and Y328 within the binding site of the μ-opioid receptor influence opiate ligand bias.

PubMed

Hothersall, J Daniel; Torella, Rubben; Humphreys, Sian; Hooley, Monique; Brown, Alastair; McMurray, Gordon; Nickolls, Sarah A

2017-05-15

The development of G protein-biased agonists for the μ-opioid receptor (MOR) offers a clear drug discovery rationale for improved analgesia and reduced side-effects of opiate pharmacotherapy. However, our understanding of the molecular mechanisms governing ligand bias is limited, which hinders our ability to rationally design biased compounds. We have investigated the role of MOR binding site residues W320 and Y328 in controlling bias, by receptor mutagenesis. The pharmacology of a panel of ligands in a cAMP and a β-arrestin2 assay were compared between the wildtype and mutated receptors, with bias factors calculated by operational analysis using ΔΔlog(τ/K A ) values. [ 3 H]diprenorphine competition binding was used to estimate affinity changes. Introducing the mutations W320A and Y328F caused changes in pathway bias, with different patterns of change between ligands. For example, DAMGO increased relative β-arrestin2 activity at the W320A mutant, whilst its β-arrestin2 response was completely lost at Y328F. In contrast, endomorphin-1 gained activity with Y328F but lost activity at W320A, in both pathways. For endomorphin-2 there was a directional shift from cAMP bias at the wildtype towards more β-arrestin2 bias at W320A. We also observe clear uncoupling between mutation-driven changes in function and binding affinity. These findings suggest that the mutations influenced the balance of pathway activation in a ligand-specific manner, thus identifying residues in the MOR binding pocket that govern ligand bias. This increases our understanding of how ligand/receptor binding interactions can be translated into agonist-specific pathway activation. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Characterization of the efficacies of osimertinib and nazartinib against cells expressing clinically relevant epidermal growth factor receptor mutations.

PubMed

Masuzawa, Keita; Yasuda, Hiroyuki; Hamamoto, Junko; Nukaga, Shigenari; Hirano, Toshiyuki; Kawada, Ichiro; Naoki, Katsuhiko; Soejima, Kenzo; Betsuyaku, Tomoko

2017-12-01

Third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (EGFR-TKIs) were developed to overcome EGFR T790M-mediated resistance to first- and second-generation EGFR-TKIs. Third-generation EGFR-TKIs, such as osimertinib and nazartinib, are effective for patients with the EGFR T790M mutation. However, there are no direct comparison data to guide the selection of a third-generation EGFR-TKI for patients with different EGFR mutations. We previously established an in vitro model to estimate the therapeutic windows of EGFR-TKIs by comparing their relative efficacies against cells expressing mutant or wild type EGFRs. The present study used this approach to characterize the efficacy of third-generation EGFR-TKIs and compare them with that of other EGFR-TKIs. Treatment efficacy was examined using human lung cancer-derived cell lines and Ba/F3 cells, which were transduced with clinically relevant mutant EGFRs. Interestingly, mutation-related differences in EGFR-TKI sensitivity were observed. For classic EGFR mutations (exon 19 deletion and L858R, with or without T790M), osimertinib showed lower IC50 values and wider therapeutic windows than nazartinib. For less common EGFR mutations (G719S or L861Q), afatinib showed the lowest IC50 values. For G719S+T790M or L861Q+T790M, the IC50 values of osimertinib and nazartinib were around 100 nM, which was 10- to 100-fold higher than those for classic+T790M mutations. On the contrary, osimertinib and nazartinib showed similar efficacies in cells expressing EGFR exon 20 insertions. The findings highlight the diverse mutation-related sensitivity pattern of EGFR-TKIs. These data may help in the selection of EGFR-TKIs for non-small cell lung cancer patients harboring EGFR mutations.

Characterization of the efficacies of osimertinib and nazartinib against cells expressing clinically relevant epidermal growth factor receptor mutations

PubMed Central

Masuzawa, Keita; Yasuda, Hiroyuki; Hamamoto, Junko; Nukaga, Shigenari; Hirano, Toshiyuki; Kawada, Ichiro; Naoki, Katsuhiko; Soejima, Kenzo; Betsuyaku, Tomoko

2017-01-01

Third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (EGFR-TKIs) were developed to overcome EGFR T790M-mediated resistance to first- and second-generation EGFR-TKIs. Third-generation EGFR-TKIs, such as osimertinib and nazartinib, are effective for patients with the EGFR T790M mutation. However, there are no direct comparison data to guide the selection of a third-generation EGFR-TKI for patients with different EGFR mutations. We previously established an in vitro model to estimate the therapeutic windows of EGFR-TKIs by comparing their relative efficacies against cells expressing mutant or wild type EGFRs. The present study used this approach to characterize the efficacy of third-generation EGFR-TKIs and compare them with that of other EGFR-TKIs. Treatment efficacy was examined using human lung cancer-derived cell lines and Ba/F3 cells, which were transduced with clinically relevant mutant EGFRs. Interestingly, mutation-related differences in EGFR-TKI sensitivity were observed. For classic EGFR mutations (exon 19 deletion and L858R, with or without T790M), osimertinib showed lower IC50 values and wider therapeutic windows than nazartinib. For less common EGFR mutations (G719S or L861Q), afatinib showed the lowest IC50 values. For G719S+T790M or L861Q+T790M, the IC50 values of osimertinib and nazartinib were around 100 nM, which was 10- to 100-fold higher than those for classic+T790M mutations. On the contrary, osimertinib and nazartinib showed similar efficacies in cells expressing EGFR exon 20 insertions. The findings highlight the diverse mutation-related sensitivity pattern of EGFR-TKIs. These data may help in the selection of EGFR-TKIs for non-small cell lung cancer patients harboring EGFR mutations. PMID:29285266

Irreversible inhibitors of the EGF receptor may circumvent acquired resistance to gefitinib

PubMed Central

Kwak, Eunice L.; Sordella, Raffaella; Bell, Daphne W.; Godin-Heymann, Nadia; Okimoto, Ross A.; Brannigan, Brian W.; Harris, Patricia L.; Driscoll, David R.; Fidias, Panos; Lynch, Thomas J.; Rabindran, Sridhar K.; McGinnis, John P.; Wissner, Allan; Sharma, Sreenath V.; Isselbacher, Kurt J.; Settleman, Jeffrey; Haber, Daniel A.

2005-01-01

Non-small cell lung cancers (NSCLCs) with activating mutations in the kinase domain of the epidermal growth factor receptor (EGFR) demonstrate dramatic, but transient, responses to the reversible tyrosine kinase inhibitors gefitinib (Iressa) and erlotinib (Tarceva). Some recurrent tumors have a common secondary mutation in the EGFR kinase domain, T790M, conferring drug resistance, but in other cases the mechanism underlying acquired resistance is unknown. In studying multiple sites of recurrent NSCLCs, we detected T790M in only a small percentage of tumor cells. To identify additional mechanisms of acquired resistance to gefitinib, we used NSCLC cells harboring an activating EGFR mutation to generate multiple resistant clones in vitro. These drug-resistant cells demonstrate continued dependence on EGFR and ERBB2 signaling for their viability and have not acquired secondary EGFR mutations. However, they display increased internalization of ligand-activated EGFR, consistent with altered receptor trafficking. Although gefitinib-resistant clones are cross-resistant to related anilinoquinazolines, they demonstrate sensitivity to a class of irreversible inhibitors of EGFR. These inhibitors also show effective inhibition of signaling by T790M-mutant EGFR and killing of NSCLC cells with the T790M mutation. Both mechanisms of gefitinib resistance are therefore circumvented by irreversible tyrosine kinase inhibitors. Our findings suggest that one of these, HKI-272, may prove highly effective in the treatment of EGFR-mutant NSCLCs, including tumors that have become resistant to gefitinib or erlotinib. PMID:15897464

Structure-Activity Relationship in TLR4 Mutations: Atomistic Molecular Dynamics Simulations and Residue Interaction Network Analysis

NASA Astrophysics Data System (ADS)

Anwar, Muhammad Ayaz; Choi, Sangdun

2017-03-01

Toll-like receptor 4 (TLR4), a vital innate immune receptor present on cell surfaces, initiates a signaling cascade during danger and bacterial intrusion. TLR4 needs to form a stable hexamer complex, which is necessary to dimerize the cytoplasmic domain. However, D299G and T399I polymorphism may abrogate the stability of the complex, leading to compromised TLR4 signaling. Crystallography provides valuable insights into the structural aspects of the TLR4 ectodomain; however, the dynamic behavior of polymorphic TLR4 is still unclear. Here, we employed molecular dynamics simulations (MDS), as well as principal component and residue network analyses, to decipher the structural aspects and signaling propagation associated with mutations in TLR4. The mutated complexes were less cohesive, displayed local and global variation in the secondary structure, and anomalous decay in rotational correlation function. Principal component analysis indicated that the mutated complexes also exhibited distinct low-frequency motions, which may be correlated to the differential behaviors of these TLR4 variants. Moreover, residue interaction networks (RIN) revealed that the mutated TLR4/myeloid differentiation factor (MD) 2 complex may perpetuate abnormal signaling pathways. Cumulatively, the MDS and RIN analyses elucidated the mutant-specific conformational alterations, which may help in deciphering the mechanism of loss-of-function mutations.

Comparison of Epidermal Growth Factor Receptor Mutations between Metastatic Lymph Node Diagnosed by EBUS-TBNA and Primary Tumor in Non-Small Cell Lung Cancer

PubMed Central

Kang, Hyo Jae; Hwangbo, Bin; Lee, Jin Soo; Kim, Moon Soo; Lee, Jong Mog; Lee, Geon-Kook

2016-01-01

Introduction Although the use of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is increasing for epidermal growth factor receptor (EGFR) testing in lung cancer, the discordance rate in EGFR mutations between lymph node (LN) samples obtained by EBUS-TBNA and primary tumor (PT) is not well known. Thus, we compared the EGFR mutation status of LN samples obtained by EBUS-TBNA and PTs to estimate the efficacy of using EBUS-TBNA specimens for EGFR testing in advanced, non-squamous, non-small cell lung cancer (NSCLC). Materials and Methods Using data of patients from the EBUS-TBNA database (N = 1914) obtained between January 2009 and January 2013, we identified 100 treatment-naïve, advanced, non-squamous NSCLC patients (stage 3 and 4) with matched LN specimens obtained by EBUS-TBNA and PT specimens. Of these, 74 patients with paired specimens were feasible for EGFR mutation analysis, which we performed using a direct sequencing method. Results Of the 74 cases, at least one major [exon 19 deleted (19del) and L858R] or minor (T790M, exon 20 insertion, and other point mutations) EGFR mutation was detected in 31 cases (41.9%), which included PT (n = 31, 41.9%) and LN (n = 28, 37.8%) specimens. Major mutations were detected in 25 PT (33.8%, 19del = 13, L858R = 12) and 22 LN (29.8%, 19del = 11, L858R = 11) specimens. The discordance rate in major mutations between matched PT and LN specimens was 4.1% (3/74). Among minor mutations, T790M was detected in LN specimen only in 2 cases with L858R in PT and LN. The discordance rate major and minor EGFR mutations combined between matched PT and LN specimens was 12% (9/74). Conclusions We observed a high concordance rate of major EGFR mutations between matched LN specimens sampled by EBUS-TBNA and PTs, suggesting that LN samples obtained by EBUS-TBNA from advanced non-squamous NSCLC patients are effective for use in EGFR mutation testing. PMID:27685950

Recurrent fever and arthralgia as the presentation of tumor necrosis factor receptor-associated periodic syndrome (TRAPS) in a Chinese girl: a case report and review of the literature.

PubMed

Chen, Yanxia; Huang, Xingqi; Zheng, Sujie; Zhu, Zhongliang; Yang, Wei; Liu, Jinlin

2018-05-01

Tumor necrosis factor receptor-associated periodic syndrome (TRAPS) is characterized by recurrent episodes of inflammation with fever, abdominal pain, chest pain, rash, myalgia, arthralgia, conjunctivitis, and periorbital edema. This condition is a rare autosomal dominant disease that is strongly associated with heterozygous mutations in the tumor necrosis factor (TNF) receptor super family 1A (TNFRSF1A) gene. This condition is believed to be more common in Western countries than in Asian countries, and the AA amyloidosis rate for European countries is estimated to be 10%. Herein, we report the case of a 14-year-old girl with recurrent fever and arthralgia with inflammatory marker elevation for 10 years. After extensive investigation of the infectious etiology with negative results and similar phenomenon observed within her family, the diagnosis of TRAPS was made based on next-generation sequencing, which revealed a T50M mutation; she was also sensitive to corticosteroids. Although none of our TRAPS patients developed AA amyloidosis, we suggest the continual monitoring of urinalysis results and serum amyloid A concentrations during long-term follow-up. Moreover, we also reviewed the related literature and found no Asian patients who had developed AA amyloidosis.

Unliganded fibroblast growth factor receptor 1 forms density-independent dimers.

PubMed

Comps-Agrar, Laëtitia; Dunshee, Diana Ronai; Eaton, Dan L; Sonoda, Junichiro

2015-10-02

Fibroblast growth factors receptors (FGFRs) are thought to initiate intracellular signaling cascades upon ligand-induced dimerization of the extracellular domain. Although the existence of unliganded FGFR1 dimers on the surface of living cells has been proposed, this notion remains rather controversial. Here, we employed time-resolved Förster resonance energy transfer combined with SNAP- and ACP-tag labeling in COS7 cells to monitor dimerization of full-length FGFR1 at the cell-surface with or without the coreceptor βKlotho. Using this approach we observed homodimerization of unliganded FGFR1 that is independent of its surface density. The homo-interaction signal observed for FGFR1 was indeed as robust as that obtained for epidermal growth factor receptor (EGFR) and was further increased by the addition of activating ligands or pathogenic mutations. Mutational analysis indicated that the kinase and the transmembrane domains, rather than the extracellular domain, mediate the ligand-independent FGFR1 dimerization. In addition, we observed a formation of a higher order ligand-independent complex by the c-spliced isoform of FGFR1 and βKlotho. Collectively, our approach provides novel insights into the assembly and dynamics of the full-length FGFRs on the cell surface. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Hypogonadotropic hypogonadism due to a novel missense mutation in the first extracellular loop of the neurokinin B receptor.

PubMed

Guran, Tulay; Tolhurst, Gwen; Bereket, Abdullah; Rocha, Nuno; Porter, Keith; Turan, Serap; Gribble, Fiona M; Kotan, L Damla; Akcay, Teoman; Atay, Zeynep; Canan, Husniye; Serin, Ayse; O'Rahilly, Stephen; Reimann, Frank; Semple, Robert K; Topaloglu, A Kemal

2009-10-01

The neurokinin B (NKB) receptor, encoded by TACR3, is widely expressed within the central nervous system, including hypothalamic nuclei involved in regulating GnRH release. We have recently reported two mutations in transmembrane segments of the receptor and a missense mutation in NKB in patients with normosmic isolated hypogonadotropic hypogonadism (nIHH). We sequenced the TACR3 gene in a family in which three siblings had nIHH. The novel mutant receptor thus identified was studied in a heterologous expression system using calcium flux as the functional readout. All affected siblings were homozygous for the His148Leu mutation, in the first extracellular loop of the NKB receptor. The His148Leu mutant receptor exhibited profoundly impaired signaling in response to NKB (EC(50) = 3 +/- 0.1 nm and >5 microm for wild-type and His148Leu, respectively). The location of the mutation in an extracellular part of the receptor led us also to test whether senktide, a synthetic NKB analog, may retain ability to stimulate the mutant receptor. However, the signaling activity of the His148Leu receptor in response to senktide was also severely impaired (EC(50) = 1 +/- 1 nm for wild-type and no significant response of His148Leu to 10 microm). Homozygosity for the TACR3 His148Leu mutation leads to failure of sexual maturation in humans, whereas signaling by the mutant receptor in vitro in response to either NKB or senktide is severely impaired. These observations further strengthen the link between NKB, the NKB receptor, and regulation of human reproductive function.

Mastocytosis: a mutated KIT receptor induced myeloproliferative disorder

PubMed Central

Chatterjee, Anindya; Ghosh, Joydeep; Kapur, Reuben

2015-01-01

Although more than 90% systemic mastocytosis (SM) patients express gain of function mutations in the KIT receptor, recent next generation sequencing has revealed the presence of several additional genetic and epigenetic mutations in a subset of these patients, which confer poor prognosis and inferior overall survival. A clear understanding of how genetic and epigenetic mutations cooperate in regulating the tremendous heterogeneity observed in these patients will be essential for designing effective treatment strategies for this complex disease. In this review, we describe the clinical heterogeneity observed in patients with mastocytosis, the nature of relatively novel mutations identified in these patients, therapeutic strategies to target molecules downstream from activating KIT receptor and finally we speculate on potential novel strategies to interfere with the function of not only the oncogenic KIT receptor but also epigenetic mutations seen in these patients. PMID:26158763

A nonsense mutation in the LDL receptor gene leads to familial hypercholesterolemia in the Druze sect

DOE Office of Scientific and Technical Information (OSTI.GOV)

Landsberger, D.; Meiner, V.; Reshef, A.

1992-02-01

Familial hypercholesterolemia (FH) is an autosomal dominant disease caused by mutations in the LDL receptor gene. Here the authors characterize and LDL receptor mutation that is associated with a distinct haplotype and causes FH in the Druze, a small Middle Eastern Islamic sect with a high degree of inbreeding. The mutation was found in FH families from two distinct Druze villages from the Golan Heights (northern Israel). It was not found either in another Druze FH family residing in a different geographical area nor in eight Arab and four Jewish FH heterozygote index cases whose hypercholesterolemia cosegregates with an identicalmore » LDL receptor gene haplotype. The mutation, a single-base substitution, results in a termination codon in exon 4 of the LDL receptor gene that encodes for the fourth repeat of the binding domain of the mature receptor. It can be diagnosed by allele-specific oligonucleotide hybridization of PCR-amplified DNA from FH patients.« less

The safety and efficacy of osimertinib for the treatment of EGFR T790M mutation positive non-small-cell lung cancer

PubMed Central

Gao, Xin; Le, Xiuning; Costa, Daniel B.

2016-01-01

First- and second-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) are the evidence-based first-line treatment for metastatic non-small-cell lung cancers (NSCLCs) that harbor sensitizing EGFR mutations (i.e., exon 19 deletions or L858R). However, acquired resistance to EGFR TKI monotherapy occurs invariably within a median time frame of one year. The most common form of biological resistance is through the selection of tumor clones harboring the EGFR T790M mutation, present in >50% of repeat biopsies. The presence of the EGFR T790M mutation negates the inhibitory activity of gefitinib, erlotinib, and afatinib. A novel class of third-generation EGFR TKIs has been identified by probing a series of covalent pyrimidine EGFR inhibitors that bind to amino-acid residue C797 of EGFR and preferentially inhibit mutant forms of EGFR versus the wild-type receptor. We review the rapid clinical development and approval of the third-generation EGFR TKI osimertinib for treatment of NSCLCs with EGFR-T790M. PMID:26943236

Effect of receptor binding specificity on the immunogenicity and protective efficacy of influenza virus A H1 vaccines

PubMed Central

Sun, Xiangjie; Cao, Weiping; Pappas, Claudia; Liu, Feng; Katz, Jacqueline M.; Tumpey, Terrence M.

2018-01-01

The biological basis for the poor immunogenicity of unadjuvanted avian influenza A virus vaccines in mammals is not well understood. Here, we mutated the hemagglutinin (HA) of two H1N1 virus vaccines to determine whether virus receptor binding specificity contributes to the low immunogenicity of avian influenza virus vaccines. Mutations were introduced into the HA of an avian influenza virus, A/Duck/New York/15024–21/96 (Dk/96) which switched the binding preference from α2,3- to α2,6-linked sialic acid (SA). A switch in receptor specificity of the human A/South Carolina/1/18 (SC/18) virus generated a mutant virus with α2,3 SA (avian) binding preference. Inactivated vaccines were generated and administered to mice and ferrets intramuscularly. We found that the vaccines with human receptor binding preference induced slightly higher antibody titers and cell-mediated immune responses compared to their isogenic viruses with avian receptor binding specificity. Upon challenge with DK/96 or SC18 virus, differences in lung virus titers between the vaccine groups with different receptor-binding specificities were minimal. Overall, our data suggest that receptor binding specificity contributes only marginally to the immunogenicity of avian influenza vaccines and that other factors may also be involved. PMID:25078114

Significant clinical impact of recurrent BRCA1 and BRCA2 mutations in Mexico.

PubMed

Villarreal-Garza, Cynthia; Alvarez-Gómez, Rosa María; Pérez-Plasencia, Carlos; Herrera, Luis A; Herzog, Josef; Castillo, Danielle; Mohar, Alejandro; Castro, Clementina; Gallardo, Lenny N; Gallardo, Dolores; Santibáñez, Miguel; Blazer, Kathleen R; Weitzel, Jeffrey N

2015-02-01

Frequent recurrent mutations in the breast and ovarian cancer susceptibility (BRCA) genes BRCA1 and BRCA2 among Hispanics, including a large rearrangement Mexican founder mutation (BRCA1 exon 9-12 deletion [ex9-12del]), suggest that an ancestry-informed BRCA-testing strategy could reduce disparities and promote cancer prevention by enabling economic screening for hereditary breast and ovarian cancer in Mexico. In a multistage approach, 188 patients with cancer who were unselected for family cancer history (92 with ovarian cancer and 96 with breast cancer) were screened for BRCA mutations using a Hispanic mutation panel (HISPANEL) of 115 recurrent mutations in a multiplex assay (114 were screened on a mass spectroscopy platform, and a polymerase chain reaction assay was used to screen for the BRCA1 ex9-12del mutation). This was followed by sequencing of all BRCA exons and adjacent intronic regions and a BRCA1 multiplex ligation-dependent probe amplification assay (MLPA) for HISPANEL-negative patients. BRCA mutation prevalence was calculated and correlated with histology and tumor receptor status, and HISPANEL sensitivity was estimated. BRCA mutations were detected in 26 of 92 patients (28%) with ovarian cancer, in 14 of 96 patients (15%) with breast cancer overall, and in 9 of 33 patients (27%) who had tumors that were negative for estrogen receptor, progesterone receptor, and human epithelial growth factor 2 (triple-negative breast cancer). Most patients with breast cancer were diagnosed with locally advanced disease. The Mexican founder mutation (BRCA1 ex9-12del) accounted for 35% of BRCA-associated ovarian cancers and 29% of BRCA-associated breast cancers. At 2% of the sequencing and MLPA cost, HISPANEL detected 68% of all BRCA mutations. In this study, a remarkably high prevalence of BRCA mutations was observed among patients with ovarian cancer and breast cancer who were not selected for family history, and the BRCA1 ex9-12del mutation explained 33% of the total. The remarkable frequency of BRCA1 ex9-12del in Mexico City supports a nearby origin of this Mexican founder mutation and may constitute a regional public health problem. The HISPANEL mutation panel presents a translational opportunity for cost-effective genetic testing to enable breast and ovarian cancer prevention. © 2014 American Cancer Society.

Mutation of Three Residues in the Third Intracellular Loop of the Dopamine D2 Receptor Creates an Internalization-defective Receptor*

PubMed Central

Clayton, Cecilea C.; Donthamsetti, Prashant; Lambert, Nevin A.; Javitch, Jonathan A.; Neve, Kim A.

2014-01-01

Arrestins mediate desensitization and internalization of G protein-coupled receptors and also direct receptor signaling toward heterotrimeric G protein-independent signaling pathways. We previously identified a four-residue segment (residues 212–215) of the dopamine D2 receptor that is necessary for arrestin binding in an in vitro heterologous expression system but that also impairs receptor expression. We now describe the characterization of additional mutations at that arrestin binding site in the third intracellular loop. Mutating two (residues 214 and 215) or three (residues 213–215) of the four residues to alanine partially decreased agonist-induced recruitment of arrestin3 without altering activation of a G protein. Arrestin-dependent receptor internalization, which requires arrestin binding to β2-adaptin (the β2 subunit of the clathrin-associated adaptor protein AP2) and clathrin, was disproportionately affected by the three-residue mutation, with no agonist-induced internalization observed even in the presence of overexpressed arrestin or G protein-coupled receptor kinase 2. The disjunction between arrestin recruitment and internalization could not be explained by alterations in the time course of the receptor-arrestin interaction, the recruitment of G protein-coupled receptor kinase 2, or the receptor-induced interaction between arrestin and β2-adaptin, suggesting that the mutation impairs a property of the internalization complex that has not yet been identified. PMID:25336643

Dramatic intracranial response to osimertinib in a poor performance status patient with lung adenocarcinoma harboring the epidermal growth factor receptor T790M mutation: A case report.

PubMed

Uemura, Takehiro; Oguri, Tetsuya; Okayama, Minami; Furuta, Hiromi; Kanemitsu, Yoshihiro; Takakuwa, Osamu; Ohkubo, Hirotsugu; Takemura, Masaya; Maeno, Ken; Ito, Yutaka; Niimi, Akio

2017-04-01

We herein report a case of dramatic intracranial response to osimertinib in a poor performance status patient with lung adenocarcinoma harboring the epidermal growth factor receptor ( EGFR ) T790M mutation encoded in exon 20. The patient was a 59-year-old woman with EGFR exon 19 deletion-positive lung adenocarcinoma, who relapsed with multiple brain metastases. Computed tomography-guided biopsy of the left pleural tumor revealed adenocarcinoma harboring an EGFR exon 19 deletion and an EGFR T790M mutation encoded in exon 20. The patient was treated with osimertinib, a third-generation EGFR tyrosine kinase inhibitor. Two days after treatment initiation, the patient displayed profound disturbance of consciousness, possibly due to carcinomatous meningitis, and treatment had to be discontinued due to difficulty in taking osimertinib. However, the patient gradually started to recover consciousness and, after 3 days, she was again able to take osimertinib. One month after the initiation of osimertinib treatment, magnetic resonance imaging revealed an apparent reduction in brain metastases. The patient is currently under continued treatment with osimertinib. At the last follow-up (February, 2017) she exhibited partial response to the treatment.

Discovery of Selective and Noncovalent Diaminopyrimidine-Based Inhibitors of Epidermal Growth Factor Receptor Containing the T790M Resistance Mutation

DOE PAGES

Hanan, Emily J.; Eigenbrot, Charles; Bryan, Marian C.; ...

2014-11-10

Activating mutations within the epidermal growth factor receptor (EGFR) kinase domain, commonly L858R or deletions within exon 19, increase EGFR-driven cell proliferation and survival and are correlated with impressive responses to the EGFR inhibitors erlotinib and gefitinib in nonsmall cell lung cancer patients. Approximately 60% of acquired resistance to these agents is driven by a single secondary mutation within the EGFR kinase domain, specifically substitution of the gatekeeper residue threonine-790 with methionine (T790M). Due to dose-limiting toxicities associated with inhibition of wild-type EGFR (wtEGFR), we sought inhibitors of T790M-containing EGFR mutants with selectivity over wtEGFR. Here in this paper, wemore » describe the evolution of HTS hits derived from Jak2/Tyk2 inhibitors into selective EGFR inhibitors. X-ray crystal structures revealed two distinct binding modes and enabled the design of a selective series of novel diaminopyrimidine-based inhibitors with good potency against T790M-containing mutants of EGFR, high selectivity over wtEGFR, broad kinase selectivity, and desirable physicochemical properties.« less

Novel mutation identified in severe early-onset tumor necrosis factor receptor-associated periodic syndrome: a case report.

PubMed

Radhakrishna, Suhas M; Grimm, Amy; Broderick, Lori

2017-04-20

Tumor Necrosis Factor Receptor-Associated Periodic Syndrome (TRAPS) is the second most common heritable autoinflammatory disease, typically presenting in pre-school aged children with fever episodes lasting 1-3 weeks. Systemic symptoms can include rash, myalgia, ocular inflammation, and serositis. Here we report an unusual presentation of TRAPS in a 7 month old girl who presented with only persistent fever. She was initially diagnosed with incomplete Kawasaki Disease and received IVIG and infliximab; however, her fevers quickly recurred. Subsequent testing revealed a urinary tract infection, but she did not improve despite appropriate therapy. As fever continued, she developed significant abdominal distension with imaging concerning for appendicitis, followed by hyperthermia and hemodynamic instability. Given her protracted clinical course and maternal history of a poorly defined inflammatory condition, an autoinflammatory disease was considered. Therapy with anakinra was initiated, resulting in rapid resolution of fever and normalization of inflammatory markers. She was found to have a previously unreported mutation, Thr90Pro, in the TNFRSF1A gene associated with TRAPS. This novel mutation was also confirmed in the patient's mother and maternal uncle. This report reviews a severe case of TRAPS in infancy associated with a novel mutation, Thr90Pro, in the TNFRSF1A gene, and emphasizes that autoinflammatory disease should be considered in the differential of infants with fever of unknown origin.

Smoking History as a Predictor of Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitors in Patients with Non-Small Cell Lung Cancer Harboring EGFR Mutations.

PubMed

Nishinarita, Noriko; Igawa, Satoshi; Kasajima, Masashi; Kusuhara, Seiichiro; Harada, Shinya; Okuma, Yuriko; Sugita, Keisuke; Ozawa, Takahiro; Fukui, Tomoya; Mitsufuji, Hisashi; Yokoba, Masanori; Katagiri, Masato; Kubota, Masaru; Sasaki, Jiichiro; Naoki, Katsuhiko

2018-04-26

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKIs) therapy has been recognized as the standard treatment for patients with non-small cell lung cancer (NSCLC) harboring EGFR mutations. However, resistance to EGFR-TKIs has been observed in certain subpopulations of these patients. We aimed to evaluate the impact of smoking history on the efficacy of EGFR-TKIs. The records of patients (n = 248) with NSCLC harboring activating EGFR mutations who were treated with gefitinib or erlotinib at our institution between March 2010 and June 2016 were retrospectively reviewed, and the treatment outcomes were evaluated. The overall response rate and median progression-free survival (PFS) were 59.7% and 10.7 months, respectively. The overall response rate was significantly higher in the ex- and nonsmokers than in the current smokers (64.6 vs. 51.1%, p = 0.038). PFS also differed significantly between the current smokers and the ex- and nonsmokers (12.4 vs. 7.4 months, p = 0.016). Multivariate analysis identified smoking history as an independent predictor of PFS and overall survival. The clinical data obtained in this study provide a valuable rationale for considering smoking history as a predictor of the efficacy of EGFR-TKI in NSCLC patients harboring activating EGFR mutations. © 2018 S. Karger AG, Basel.

Crenolanib is a type I tyrosine kinase inhibitor that inhibits mutant KIT D816 isoforms prevalent in systemic mastocytosis and core binding factor leukemia.

PubMed

Kampa-Schittenhelm, Kerstin Maria; Frey, Julia; Haeusser, Lara A; Illing, Barbara; Pavlovsky, Ashly A; Blumenstock, Gunnar; Schittenhelm, Marcus Matthias

2017-10-10

Activating D816 mutations of the class III receptor tyrosine kinase KIT are associated with the majority of patients with systemic mastocytosis (SM), but also core binding factor (CBF) AML, making KIT mutations attractive therapeutic targets for the treatment of these cancers. Crenolanib is a potent and selective inhibitor of wild-type as well as mutant isoforms of the class III receptor tyrosine kinases FLT3 and PDGFRα/β. Notably, crenolanib inhibits constitutively active mutant-FLT3 isoforms resulting from amino acid substitutions of aspartic acid at codon 835, which is homologous to codon 816 in the KIT gene - suggesting sensitivity against mutant-KIT D816 isoforms as well. Here we demonstrate that crenolanib targets KIT D816 in SM and CBF AML models: crenolanib inhibits cellular proliferation and initiates apoptosis of mastocytosis cell lines expressing these mutations. Target-specificity was confirmed using an isogenic cell model. In addition, we demonstrate that KIT D816 mutations are targetable with clinically achievable doses of crenolanib. Further, a rationale to combine cladribine (2-CDA), the therapeutic standard in SM, with crenolanib is provided. In conclusion, we demonstrate that crenolanib is an inhibitor of mutant-KIT D816 isoforms at clinically achievable concentrations, and thus may be a potential treatment for SM and CBF AML as a monotherapy or in combination approaches.

Putative lung adenocarcinoma with epidermal growth factor receptor mutation presenting as carcinoma of unknown primary site

PubMed Central

Yamasaki, Masahiro; Funaishi, Kunihiko; Saito, Naomi; Sakano, Ayaka; Fujihara, Megumu; Daido, Wakako; Ishiyama, Sayaka; Deguchi, Naoko; Taniwaki, Masaya; Ohashi, Nobuyuki; Hattori, Noboru

2018-01-01

Abstract Rationale: Only a few cases of putative lung adenocarcinoma presenting as carcinoma of unknown primary site (CUP) with epidermal growth factor receptor (EGFR) mutation have been reported, and the efficacy of EGFR-tyrosine kinase inhibitors (TKIs) for these cases is unclear. Patient concerns and diagnoses: A 67-year-old man complained of paresis of the right lower extremity, dysarthria, and memory disturbance. Computed tomography and magnetic resonance imaging showed multiple brain tumors with brain edema and swelling of the left supraclavicular, mediastinal, and upper abdominal lymph nodes. Moreover, a metastatic duodenal tumor was detected via upper gastrointestinal endoscopy examination. The biopsy specimen of the lesion was examined and was diagnosed as adenocarcinoma with CK7 and TTF-1 positivity. Finally, the case was diagnosed as EGFR mutation-positive putative lung adenocarcinoma presenting as CUP. Interventions and outcomes: Oral erlotinib, an EGFR-TKI, was administered at 150 mg daily. Five weeks later, the brain lesions and several swollen lymph nodes showed marked improvement, and the symptoms of the patient also improved. Three months later, the duodenal lesion was undetected on upper gastrointestinal endoscopy. After an 8-month follow-up, the patient was well with no disease progression. Lessons: Putative lung adenocarcinoma presenting as CUP may have EGFR mutation, and EGFR-TKI therapy may be effective for such malignancy. PMID:29443782

Mutations Affecting G-Protein Subunit α11 in Hypercalcemia and Hypocalcemia

PubMed Central

Babinsky, Valerie N.; Head, Rosie A.; Cranston, Treena; Rust, Nigel; Hobbs, Maurine R.; Heath, Hunter; Thakker, Rajesh V.

2013-01-01

BACKGROUND Familial hypocalciuric hypercalcemia is a genetically heterogeneous disorder with three variants: types 1, 2, and 3. Type 1 is due to loss-of-function mutations of the calcium-sensing receptor, a guanine nucleotide–binding protein (G-protein)–coupled receptor that signals through the G-protein subunit α11 (Gα11). Type 3 is associated with adaptor-related protein complex 2, sigma 1 subunit (AP2S1) mutations, which result in altered calcium-sensing receptor endocytosis. We hypothesized that type 2 is due to mutations effecting Gα11 loss of function, since Gα11 is involved in calcium-sensing receptor signaling, and its gene (GNA11) and the type 2 locus are colocalized on chromosome 19p13.3. We also postulated that mutations effecting Gα11 gain of function, like the mutations effecting calcium-sensing receptor gain of function that cause autosomal dominant hypocalcemia type 1, may lead to hypocalcemia. METHODS We performed GNA11 mutational analysis in a kindred with familial hypocalciuric hypercalcemia type 2 and in nine unrelated patients with familial hypocalciuric hypercalcemia who did not have mutations in the gene encoding the calcium-sensing receptor (CASR) or AP2S1. We also performed this analysis in eight unrelated patients with hypocalcemia who did not have CASR mutations. In addition, we studied the effects of GNA11 mutations on Gα11 protein structure and calcium-sensing receptor signaling in human embryonic kidney 293 (HEK293) cells. RESULTS The kindred with familial hypocalciuric hypercalcemia type 2 had an in-frame deletion of a conserved Gα11 isoleucine (Ile200del), and one of the nine unrelated patients with familial hypocalciuric hypercalcemia had a missense GNA11 mutation (Leu135Gln). Missense GNA11 mutations (Arg181Gln and Phe341Leu) were detected in two unrelated patients with hypocalcemia; they were therefore identified as having autosomal dominant hypocalcemia type 2. All four GNA11 mutations predicted disrupted protein structures, and assessment on the basis of in vitro expression showed that familial hypocalciuric hypercalcemia type 2–associated mutations decreased the sensitivity of cells expressing calcium-sensing receptors to changes in extracellular calcium concentrations, whereas autosomal dominant hypocalcemia type 2–associated mutations increased cell sensitivity. CONCLUSIONS Gα11 mutants with loss of function cause familial hypocalciuric hypercalcemia type 2, and Gα11 mutants with gain of function cause a clinical disorder designated as autosomal dominant hypocalcemia type 2. (Funded by the United Kingdom Medical Research Council and others.) PMID:23802516

Genetic dissection of TrkB activated signalling pathways required for specific aspects of the taste system

PubMed Central

2014-01-01

Background Neurotrophin-4 (NT-4) and brain derived neurotrophic factor (BDNF) bind to the same receptor, Ntrk2/TrkB, but play distinct roles in the development of the rodent gustatory system. However, the mechanisms underlying these processes are lacking. Results Here, we demonstrate, in vivo, that single or combined point mutations in major adaptor protein docking sites on TrkB receptor affect specific aspects of the mouse gustatory development, known to be dependent on BDNF or NT-4. In particular, mice with a mutation in the TrkB-SHC docking site had reduced gustatory neuron survival at both early and later stages of development, when survival is dependent on NT-4 and BDNF, respectively. In addition, lingual innervation and taste bud morphology, both BDNF-dependent functions, were altered in these mutants. In contrast, mutation of the TrkB-PLCγ docking site alone did not affect gustatory neuron survival. Moreover, innervation to the tongue was delayed in these mutants and taste receptor expression was altered. Conclusions We have genetically dissected pathways activated downstream of the TrkB receptor that are required for specific aspects of the taste system controlled by the two neurotrophins NT-4 and BDNF. In addition, our results indicate that TrkB also regulate the expression of specific taste receptors by distinct signalling pathways. These results advance our knowledge of the biology of the taste system, one of the fundamental sensory systems crucial for an organism to relate to the environment. PMID:25256039

Genetics and phenomics of inherited and sporadic non-autoimmune hyperthyroidism.

PubMed

Gozu, Hulya Iliksu; Lublinghoff, Julia; Bircan, Rifat; Paschke, Ralf

2010-06-30

TSH receptor (TSHR) germline mutations occur as activating mutations in familial non-autoimmune hyperthyroidism (FNAH) or sporadic non-autoimmune hyperthyroidism (SNAH). Up to date 17 constitutively activating TSHR mutations have been reported in 24 families with FNAH. The diagnosis of FNAH should be considered in cases with a positive family history, early onset of hyperthyroidism, goiter, absence of clinical stigmata of autoimmunity and recurrent hyperthyroidism. Moreover, 14 subjects with sporadic non-autoimmune hyperthyroidism and 10 different TSH receptor germline mutations have been reported. The main characteristic of SNAH is a negative family history. Additional consequences of prolonged neonatal hyperthyroidism (mental retardation, speech disturbances and craniosynostosis) have often been reported in SNAH. No genotype-phenotype relationship has been reported in patients with germline TSHR mutations. There is no association of in vitro activities determined by linear regression analysis (LRA) and several clinical indicators of hyperthyroidism activity for SNAH. However, the comparison of the LRA values of sporadic TSHR mutations with LRA values of familial TSHR mutations does show a significantly higher median LRA value for sporadic as compared to familial autosomal dominant hyperthyroidism. This finding is in line with the clinical impression of a more active clinical course in patients with SNAH. However, additional genetic, constitutional or environmental factors are most likely responsible for the phenotypic variations of the disease and the lack of correlation between in vitro activities of the TSHR mutations and the severity of hyperthyroidism. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

Glutamate receptor mutations in psychiatric and neurodevelopmental disorders

PubMed Central

Soto, David; Altafaj, Xavier; Sindreu, Carlos; Bayés, Àlex

2014-01-01

Alterations in glutamatergic neurotransmission have long been associated with psychiatric and neurodevelopmental disorders (PNDD), but only recent advances in high-throughput DNA sequencing have allowed interrogation of the prevalence of mutations in glutamate receptors (GluR) among afflicted individuals. In this review we discuss recent work describing GluR mutations in the context of PNDDs. Although there are no strict relationships between receptor subunit or type and disease, some interesting preliminary conclusions have arisen. Mutations in genes coding for ionotropic glutamate receptor subunits, which are central to synaptic transmission and plasticity, are mostly associated with intellectual disability and autism spectrum disorders. In contrast, mutations of metabotropic GluRs, having a role on modulating neural transmission, are preferentially associated with psychiatric disorders. Also, the prevalence of mutations among GluRs is highly heterogeneous, suggesting a critical role of certain subunits in PNDD pathophysiology. The emerging bias between GluR subtypes and specific PNDDs may have clinical implications. PMID:24605182

Glutamate receptor mutations in psychiatric and neurodevelopmental disorders.

PubMed

Soto, David; Altafaj, Xavier; Sindreu, Carlos; Bayés, Alex

2014-01-01

Alterations in glutamatergic neurotransmission have long been associated with psychiatric and neurodevelopmental disorders (PNDD), but only recent advances in high-throughput DNA sequencing have allowed interrogation of the prevalence of mutations in glutamate receptors (GluR) among afflicted individuals. In this review we discuss recent work describing GluR mutations in the context of PNDDs. Although there are no strict relationships between receptor subunit or type and disease, some interesting preliminary conclusions have arisen. Mutations in genes coding for ionotropic glutamate receptor subunits, which are central to synaptic transmission and plasticity, are mostly associated with intellectual disability and autism spectrum disorders. In contrast, mutations of metabotropic GluRs, having a role on modulating neural transmission, are preferentially associated with psychiatric disorders. Also, the prevalence of mutations among GluRs is highly heterogeneous, suggesting a critical role of certain subunits in PNDD pathophysiology. The emerging bias between GluR subtypes and specific PNDDs may have clinical implications.

A natural allele of Nxf1/TAP supresses retrovirus insertional mutations

PubMed Central

Floyd, Jennifer A.; Gold, David A.; Concepcion, Dorothy; Poon, Tiffany H.; Wang, Xiaobo; Keithley, Elizabeth; Chen, Dan; Ward, Erica J.; Chinn, Steven B.; Friedman, Rick A.; Yu, Hon-Tsen; Moriwaki, Kazuo; Shiroishi, Toshihiko; Hamilton, Bruce A.

2009-01-01

Endogenous retroviruses have shaped the evolution of mammalian genomes. Host genes that control the effects of retrovirus insertions are therefore of great interest. The Modifier-of-vibrator-1 locus controls level of correctly processed mRNA from genes mutated by endogenous retrovirus insertions into introns, including the pitpnvb tremor mutation and the Eya1BOR model of human branchiootorenal syndrome. Positional complementation cloning identifies Mvb1 as the nuclear export factor Nxf1, providing an unexpected link between mRNA export receptor and pre-mRNA processing. Population structure of the suppressing allele in wild M. m. castaneus suggests selective advantage. A congenic Mvb1CAST allele is a useful tool for modifying gene expression from existing mutations and could be used to manipulate engineered mutations containing retroviral elements. PMID:14517553

An exon 53 frameshift mutation in CUBN abrogates cubam function and causes Imerslund-Gräsbeck syndrome in dogs.

PubMed

Fyfe, John C; Hemker, Shelby L; Venta, Patrick J; Fitzgerald, Caitlin A; Outerbridge, Catherine A; Myers, Sherry L; Giger, Urs

2013-08-01

Cobalamin malabsorption accompanied by selective proteinuria is an autosomal recessive disorder known as Imerslund-Gräsbeck syndrome in humans and was previously described in dogs due to amnionless (AMN) mutations. The resultant vitamin B12 deficiency causes dyshematopoiesis, lethargy, failure to thrive, and life-threatening metabolic disruption in the juvenile period. We studied 3 kindreds of border collies with cobalamin malabsorption and mapped the disease locus in affected dogs to a 2.9Mb region of homozygosity on canine chromosome 2. The region included CUBN, the locus encoding cubilin, a peripheral membrane protein that in concert with AMN forms the functional intrinsic factor-cobalamin receptor expressed in ileum and a multi-ligand receptor in renal proximal tubules. Cobalamin malabsorption and proteinuria comprising CUBN ligands were demonstrated by radiolabeled cobalamin uptake studies and SDS-PAGE, respectively. CUBN mRNA and protein expression were reduced ~10 fold and ~20 fold, respectively, in both ileum and kidney of affected dogs. DNA sequencing demonstrated a single base deletion in exon 53 predicting a translational frameshift and early termination codon likely triggering nonsense mediated mRNA decay. The mutant allele segregated with the disease in the border collie kindred. The border collie disorder indicates that a CUBN mutation far C-terminal from the intrinsic factor-cobalamin binding site can abrogate receptor expression and cause Imerslund-Gräsbeck syndrome. Copyright © 2013 Elsevier Inc. All rights reserved.

A disease-associated mutation in the adhesion GPCR BAI2 (ADGRB2) increases receptor signaling activity.

PubMed

Purcell, Ryan H; Toro, Camilo; Gahl, William A; Hall, Randy A

2017-12-01

Mutations in G protein-coupled receptors (GPCRs) that increase constitutive signaling activity can cause human disease. A de novo C-terminal mutation (R1465W) in the adhesion GPCR BAI2 (also known as ADGRB2) was identified in a patient suffering from progressive spastic paraparesis and other neurological symptoms. In vitro studies revealed that this mutation strongly increases the constitutive signaling activity of an N-terminally cleaved form of BAI2, which represents the activated form of the receptor. Further studies dissecting the mechanism(s) underling this effect revealed that wild-type BAI2 primarily couples to Gα z , with the R1465W mutation conferring increased coupling to Gα i . The R1465W mutation also increases the total and surface expression of BAI2. The mutation has no effect on receptor binding to β-arrestins, but does perturb binding to the endocytic protein endophilin A1, identified here as a novel interacting partner for BAI2. These studies provide new insights into the signaling capabilities of the adhesion GPCR BAI2/ADGRB2 and shed light on how an apparent gain-of-function mutation to the receptor's C-terminus may lead to human disease. © 2017 Wiley Periodicals, Inc.

Somatic GNAQ Mutation is Enriched in Brain Endothelial Cells in Sturge-Weber Syndrome.

PubMed

Huang, Lan; Couto, Javier A; Pinto, Anna; Alexandrescu, Sanda; Madsen, Joseph R; Greene, Arin K; Sahin, Mustafa; Bischoff, Joyce

2017-02-01

Sturge-Weber syndrome (SWS) is a rare congenital neurocutaneous disorder characterized by facial and extracraniofacial capillary malformations and capillary-venule malformations in the leptomeninges. A somatic mosaic mutation in GNAQ (c.548G>A; p.R183Q) was found in SWS brain and skin capillary malformations. Our laboratory showed endothelial cells in skin capillary malformations are enriched for the GNAQ mutation. The purpose of this study is to determine whether the GNAQ mutation is also enriched in endothelial cells in affected SWS brain. Two human SWS brain specimens were fractionated by fluorescence-activated cell sorting into hematopoietic (CD45), endothelial (CD31, VE-Cadherin, and vascular endothelial growth factor receptor 2), and perivascular (platelet-derived growth factor receptor beta) cells and cells negative for all markers. The sorted cell populations were analyzed for GNAQ p.R183Q mutation by droplet digital polymerase chain reaction. SWS patient-derived brain endothelial cells were selected by anti-CD31-coated magnetic beads and cultured in endothelial growth medium in vitro. The GNAQ p.R183Q mutation was present in brain endothelial cells in two SWS specimens, with mutant allelic frequencies of 34.7% and 24.0%. Cells negative for all markers also harbored the GNAQ mutation. The mutant allelic frequencies in these unidentified cells were 9.2% and 8.4%. SWS patient-derived brain endothelial cells with mutant allelic frequencies of 14.7% and 21% survived and proliferated in vitro. Our study provides evidence that GNAQ p.R183Q mutation is enriched in endothelial cells in SWS brain lesions and thereby reveals endothelial cells as a source of aberrant Gαq signaling. This will help to understand the pathophysiology of SWS, to discover biomarkers for predicting cerebral involvement, and to develop therapeutic targets to prevent neurological impairments in SWS. Copyright © 2016 Elsevier Inc. All rights reserved.

Fixation effect of SurePath preservative fluids using epidermal growth factor receptor mutation-specific antibodies for immunocytochemistry.

PubMed

Kawahara, Akihiko; Taira, Tomoki; Abe, Hideyuki; Watari, Kosuke; Murakami, Yuichi; Fukumitsu, Chihiro; Takase, Yorihiko; Yamaguchi, Tomohiko; Azuma, Koichi; Akiba, Jun; Ono, Mayumi; Kage, Masayoshi

2014-02-01

Cytological diagnosis of respiratory disease has become important, not only for histological typing using immunocytochemistry (ICC) but also for molecular DNA analysis of cytological material. The aim of this study was to investigate the fixation effect of SurePath preservative fluids. Human lung cancer PC9 and 11-18 cell lines, and lung adenocarcinoma cells in pleural effusion, were fixed in CytoRich Blue, CytoRich Red, 15% neutral-buffered formalin, and 95% ethanol, respectively. PC9 and 11-18 cell lines were examined by ICC with epidermal growth factor receptor (EGFR) mutation-specific antibodies, the EGFR mutation DNA assay, and fluorescence in situ hybridization. The effect of antigenic storage time was investigated in lung adenocarcinoma cells in pleural effusion by ICC using the lung cancer detection markers. PC9 and 11-18 cell lines in formalin-based fixatives showed strong staining of EGFR mutation-specific antibodies and lung cancer detection markers by ICC as compared with ethanol-based fixatives. DNA preservation with CytoRich Blue and CytoRich Red was superior to that achieved with 95% ethanol and 15% neutral-buffered formalin fixatives, whereas EGFR mutations by DNA assay and EGFR gene amplification by fluorescence in situ hybridization were successfully identified in all fixative samples. Although cytoplasmic antigens maintained high expression levels, expression levels in nuclear antigens fell as storage time increased. These results indicate that CytoRich Red is not only suitable for ICC with EGFR mutation-specific antibodies, but also for DNA analysis of cytological material, and is useful in molecular testing of lung cancer, for which various types of analyses will be needed in future. © 2013 American Cancer Society.

Environmental tobacco smoke exposure and EGFR and ALK alterations in never smokers' lung cancer. Results from the LCRINS study.

PubMed

Torres-Durán, María; Ruano-Ravina, Alberto; Kelsey, Karl T; Parente-Lamelas, Isaura; Leiro-Fernández, Virginia; Abdulkader, Ihab; Provencio, Mariano; Abal-Arca, José; Castro-Añón, Olalla; Montero-Martínez, Carmen; Vidal-García, Iria; Amenedo, Margarita; Golpe-Gómez, Antonio; Martínez, Cristina; Guzmán-Taveras, Rosirys; Mejuto-Martí, María José; Fernández-Villar, Alberto; Barros-Dios, Juan Miguel

2017-12-28

Environmental tobacco smoke (ETS) exposure is a main risk factor of lung cancer in never smokers. Epidermal Growth Factor Receptor (EGFR) mutations and ALK translocations are more frequent in never smokers' lung cancer than in ever-smokers. We performed a multicenter case-control study to assess if ETS exposure is associated with the presence of EGFR mutations and its types and if ALK translocations were related with ETS exposure. All patients were never smokers and had confirmed lung cancer diagnosis. ETS exposure during childhood showed a negative association on the probability of EGRF mutation though not significant. Exposure during adulthood, at home or at workplace, did not show any association with EGFR mutation. The mutation type L858R seemed the most associated with a lower probability of EGFR alterations for ETS exposure at home in adult life. There is no apparent association between ETS exposure and ALK translocation. These results might suggest that ETS exposure during childhood or at home in adult life could influence the EGFR mutations profile in lung cancer in never smokers, reducing the probability of presenting EFGR mutation. Copyright © 2017 Elsevier B.V. All rights reserved.

Expression of leukemia inhibitory factor and leukemia inhibitory factor receptor in the canine pituitary gland and corticotrope adenomas.

PubMed

Hanson, J M; Mol, J A; Meij, B P

2010-05-01

Leukemia inhibitory factor (LIF) is a pleiotropic cytokine of the IL-6 family that activates the hypothalamic-pituitary-adrenal axis and promotes corticotrope cell differentiation during development. The aim of this study was to investigate the expression of LIF and its receptor (LIFR) in the canine pituitary gland and in corticotrope adenomas, and to perform a mutation analysis of LIFR. Using immunohistochemistry, immunofluorescence, and quantitative expression analysis, LIF and LIFR expression were studied in pituitary glands of control dogs and in specimens of corticotrope adenoma tissue collected through hypophysectomy in dogs with pituitary-dependent hypercortisolism (PDH, Cushing's disease). Using sequence analysis, cDNA was screened for mutations in the LIFR. In the control pituitary tissues and corticotrope adenomas, there was a low magnitude of LIF expression. The LIFR, however, was highly expressed and co-localized with ACTH(1-24) expression. Cytoplasmatic immunoreactivity of LIFR was preserved in corticotrope adenomas and adjacent nontumorous cells of pars intermedia. No mutation was found on mutation analysis of the complete LIFR cDNA. Surprisingly, nuclear to perinuclear immunoreactivity for LIFR was present in nontumorous pituitary cells of the pars distalis in 10 of 12 tissue specimens from PDH dogs. These data show that LIFR is highly co-expressed with adrenocorticotropic hormone (ACTH) and alpha-melanocyte-stimulating hormone (alpha-MSH) in the canine pituitary gland and in corticotrope adenomas. Nuclear immunoreactivity for LIFR in nontumorous cells of the pars distalis may indicate the presence of a corticotrope adenoma. Copyright (c) 2009 Elsevier Inc. All rights reserved.

Surrogate endpoints for overall survival in advanced non-small-cell lung cancer patients with mutations of the epidermal growth factor receptor gene.

PubMed

Yoshino, Reiko; Imai, Hisao; Mori, Keita; Takei, Kousuke; Tomizawa, Mai; Kaira, Kyoichi; Yoshii, Akihiro; Tomizawa, Yoshio; Saito, Ryusei; Yamada, Masanobu

2014-09-01

Subsequent therapies confound the ability to discern the effect of first-line chemotherapy on overall survival (OS). We investigated whether progression-free survival (PFS), post-progression survival (PPS) and tumor response were valid surrogate endpoints for OS following first-line chemotherapy in individual patients with advanced non-small-cell lung cancer (NSCLC) harboring sensitive epidermal growth factor receptor gene mutations. We retrospectively analyzed 35 patients with advanced NSCLC treated with first-line gefitinib. The associations of PFS, PPS and tumor response with OS were analyzed. PPS was found to be strongly correlated with OS, unlike PFS and tumor shrinkage. The factors significantly associated with PPS were performance status (PS) after first-line treatment, best response to second-line treatment and number of regimens used after disease progression. PPS may be a surrogate for OS in this patient population and further therapy after disease progression following first-line chemotherapy may significantly affect OS. However, a larger study is required to validate these results.

Homodimeric cross-over structure of the human granulocyte colony-stimulating factor (GCSF) receptor signaling complex

PubMed Central

Tamada, Taro; Honjo, Eijiro; Maeda, Yoshitake; Okamoto, Tomoyuki; Ishibashi, Matsujiro; Tokunaga, Masao; Kuroki, Ryota

2006-01-01

A crystal structure of the signaling complex between human granulocyte colony-stimulating factor (GCSF) and a ligand binding region of GCSF receptor (GCSF-R), has been determined to 2.8 Å resolution. The GCSF:GCSF-R complex formed a 2:2 stoichiometry by means of a cross-over interaction between the Ig-like domains of GCSF-R and GCSF. The conformation of the complex is quite different from that between human GCSF and the cytokine receptor homologous domain of mouse GCSF-R, but similar to that of the IL-6/gp130 signaling complex. The Ig-like domain cross-over structure necessary for GCSF-R activation is consistent with previously reported thermodynamic and mutational analyses. PMID:16492764

Epidermal Growth Factor Receptor Mutation as a Risk Factor for Recurrence in Lung Adenocarcinoma.

PubMed

Hayasaka, Kazuki; Shiono, Satoshi; Matsumura, Yuki; Yanagawa, Naoki; Suzuki, Hiroyuki; Abe, Jiro; Sagawa, Motoyasu; Sakurada, Akira; Katahira, Masato; Takahashi, Satomi; Endoh, Makoto; Okada, Yoshinori

2018-06-01

The presence of epidermal growth factor receptor (EGFR) mutations is an established prognostic factor for patients with advanced lung adenocarcinoma. Here, we examined whether EGFR mutation status is a prognostic factor for patients who had undergone surgery. Clinicopathologic data from 1,463 patients who underwent complete surgical resection for lung adenocarcinoma between 2005 and 2012 were collected. Differences in postoperative recurrence-free survival and overall survival according to EGFR mutation status were evaluated. Of 835 eligible patients, the numbers of patients with wild-type EGFR (WT), exon 19 deletion (Ex19), and exon 21 L858R (Ex21) were 426, 175, and 234, respectively. Patients with Ex19 had a significantly higher incidence of extrathoracic recurrence than patients with Ex21 (p = 0.004). The 5-year recurrence-free survival rates for patients with WT, Ex19, and Ex21 were 63.0%, 67.5%, and 78.2%, respectively. The Ex21 group had a significantly longer recurrence-free survival than the WT group (p < 0.001) and the Ex19 group (p = 0.016). The 5-year overall survival for patients with WT, Ex19, and Ex21 were 76.9%, 86.5%, and 87.5%, respectively. Patients with Ex19 and Ex21 had a significantly longer overall survival than patients with WT (Ex19, p = 0.009; Ex21, p < 0.001). Multivariate analysis for recurrence-free survival showed that Ex19 was significantly associated with a worse prognosis than Ex21 (p = 0.019). Patients with Ex19 had significantly shorter recurrence-free survival and had extrathoracic recurrence more frequently than patients with Ex21 among patients with resected lung adenocarcinoma, implying that Ex19 could be a worse prognostic factor. Copyright © 2018 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Genetic predictors of MEK dependence in non-small cell lung cancer.

PubMed

Pratilas, Christine A; Hanrahan, Aphrothiti J; Halilovic, Ensar; Persaud, Yogindra; Soh, Junichi; Chitale, Dhananjay; Shigematsu, Hisayuki; Yamamoto, Hiromasa; Sawai, Ayana; Janakiraman, Manickam; Taylor, Barry S; Pao, William; Toyooka, Shinichi; Ladanyi, Marc; Gazdar, Adi; Rosen, Neal; Solit, David B

2008-11-15

Hyperactivated extracellular signal-regulated kinase (ERK) signaling is common in human cancer and is often the result of activating mutations in BRAF, RAS, and upstream receptor tyrosine kinases. To characterize the mitogen-activated protein kinase/ERK kinase (MEK)/ERK dependence of lung cancers harboring BRAF kinase domain mutations, we screened a large panel of human lung cancer cell lines (n = 87) and tumors (n = 916) for BRAF mutations. We found that non-small cell lung cancers (NSCLC) cells with both V600E and non-V600E BRAF mutations were selectively sensitive to MEK inhibition compared with those harboring mutations in epidermal growth factor receptor (EGFR), KRAS, or ALK and ROS kinase fusions. Supporting its classification as a "driver" mutation in the cells in which it is expressed, MEK inhibition in (V600E)BRAF NSCLC cells led to substantial induction of apoptosis, comparable with that seen with EGFR kinase inhibition in EGFR mutant NSCLC models. Despite high basal ERK phosphorylation, EGFR mutant cells were uniformly resistant to MEK inhibition. Conversely, BRAF mutant cell lines were resistant to EGFR inhibition. These data, together with the nonoverlapping pattern of EGFR and BRAF mutations in human lung cancer, suggest that these lesions define distinct clinical entities whose treatment should be guided by prospective real-time genotyping. To facilitate such an effort, we developed a mass spectrometry-based genotyping method for the detection of hotspot mutations in BRAF, KRAS, and EGFR. Using this assay, we confirmed that BRAF mutations can be identified in a minority of NSCLC tumors and that patients whose tumors harbor BRAF mutations have a distinct clinical profile compared with those whose tumors harbor kinase domain mutations in EGFR.

Clinical Factors Predicting Detection of T790M Mutation in Rebiopsy for EGFR-Mutant Non-small-cell Lung Cancer.

PubMed

Kawamura, Takahisa; Kenmotsu, Hirotsugu; Omori, Shota; Nakashima, Kazuhisa; Wakuda, Kazushige; Ono, Akira; Naito, Tateaki; Murakami, Haruyasu; Omae, Katsuhiro; Mori, Keita; Tanigawara, Yusuke; Nakajima, Takashi; Ohde, Yasuhisa; Endo, Masahiro; Takahashi, Toshiaki

2018-03-01

T790M, a secondary epidermal growth factor receptor (EGFR) mutation, accounts for approximately 50% of acquired resistance to EGFR-tyrosine kinase inhibitors (TKIs). To facilitate the use of third-generation EGFR-TKIs to potentially overcome T790M-mediated resistance, we evaluated the clinical factors influencing the incidence of T790M mutation. We retrospectively screened patients with non-small-cell lung cancer harboring EGFR mutations with progressive disease who were rebiopsied between January 2013 and December 2016. Factors influencing T790M status were evaluated by univariate and multivariate analysis. Among 131 rebiopsied patients for whom EGFR mutation status was available, 58 (44%) had T790M mutations. Patient characteristics at rebiopsy were not significantly different between T790M-positive and -negative groups, except for surgical history (postsurgery recurrence). Total duration of EGFR-TKI treatment before rebiopsy, TKI-free interval, EGFR-TKI treatment history immediately before rebiopsy, continuation of initial EGFR-TKI beyond progressive disease, progression-free survival after initial TKI treatment, and rebiopsy site (other than fluid samples) significantly influenced T790M status. The incidence of T790M mutation was shown by multivariate analysis to be significantly higher in patients with postsurgery recurrence and total duration of EGFR-TKI treatment ≥ 1 year before rebiopsy (odds ratio, 4.2; 95% confidence interval, 1.3-15.7 and odds ratio, 4.4; 95% confidence interval, 1.1-19.8, respectively). Postsurgery recurrence and longer total duration of EGFR-TKI treatment before rebiopsy may represent useful predictive markers for T790M detection. In patients with these clinical factors, rebiopsies are more recommended to detect T790M mutation. Copyright © 2017 Elsevier Inc. All rights reserved.

Identification of Critical Residues Involved in Ligand Binding and G Protein Signaling in Human Somatostatin Receptor Subtype 2

PubMed Central

Parry, Jesse J.; Chen, Ronald; Andrews, Rebecca; Lears, Kimberly A.

2012-01-01

G protein signaling through human somatostatin receptor subtype 2 (SSTR2) is well known, but the amino acids involved in stimulation of intracellular responses upon ligand binding have not been characterized. We constructed a series of point mutants in SSTR2 at amino acid positions 89, 139, and 140 in attempts to disrupt G protein signaling upon ligand binding. The aspartic acid changes at position 89 to either Ala, Leu, or Arg generated mutant receptors with varying expression profiles and a complete inability to bind somatostatin-14 (SST). Mutations to Asp 139 and Arg 140 also led to varying expression profiles with some mutants maintaining their affinity for SST. Mutation of Arg 140 to Ala resulted in a mutated receptor that had a Bmax and dissociation constant (Kd) similar to wild-type receptor but was still coupled to the G protein as determined in both a cAMP assay and a calcium-release assay. In contrast, mutation of Asp 139 to Asn resulted in a mutated receptor with Bmax and Kd values that were similar to wild type but was uncoupled from G protein-mediated cAMP signaling, but not calcium release. Thus, we identified mutations in SSTR2 that result in either receptor expression levels that are similar to wild type but is completely ablated for ligand binding or a receptor that maintains affinity for SST and is uncoupled from G protein-mediated cAMP signaling. PMID:22495673

Common Co-activation of AXL and CDCP1 in EGFR-mutation-positive Non-smallcell Lung Cancer Associated With Poor Prognosis.

PubMed

Karachaliou, Niki; Chaib, Imane; Cardona, Andres Felipe; Berenguer, Jordi; Bracht, Jillian Wilhelmina Paulina; Yang, Jie; Cai, Xueting; Wang, Zhigang; Hu, Chunping; Drozdowskyj, Ana; Servat, Carles Codony; Servat, Jordi Codony; Ito, Masaoki; Attili, Ilaria; Aldeguer, Erika; Capitan, Ana Gimenez; Rodriguez, July; Rojas, Leonardo; Viteri, Santiago; Molina-Vila, Miguel Angel; Ou, Sai-Hong Ignatius; Okada, Morihito; Mok, Tony S; Bivona, Trever G; Ono, Mayumi; Cui, Jean; Cajal, Santiago Ramón Y; Frias, Alex; Cao, Peng; Rosell, Rafael

2018-03-01

Epidermal growth factor receptor (EGFR)-mutation-positive non-smallcell lung cancer (NSCLC) is incurable, despite high rates of response to EGFR tyrosine kinase inhibitors (TKIs). We investigated receptor tyrosine kinases (RTKs), Src family kinases and focal adhesion kinase (FAK) as genetic modifiers of innate resistance in EGFR-mutation-positive NSCLC. We performed gene expression analysis in two cohorts (Cohort 1 and Cohort 2) of EGFR-mutation-positive NSCLC patients treated with EGFR TKI. We evaluated the efficacy of gefitinib or osimertinib with the Src/FAK/Janus kinase 2 (JAK2) inhibitor, TPX0005 in vitro and in vivo. In Cohort 1, CUB domain-containing protein-1 (CDCP1) was an independent negative prognostic factor for progression-free survival (hazard ratio of 1.79, p=0.0407) and overall survival (hazard ratio of 2.23, p=0.0192). A two-gene model based on AXL and CDCP1 expression was strongly associated with the clinical outcome to EGFR TKIs, in both cohorts of patients. Our preclinical experiments revealed that several RTKs and non-RTKs, were up-regulated at baseline or after treatment with gefitinib or osimertinib. TPX-0005 plus EGFR TKI suppressed expression and activation of RTKs and downstream signaling intermediates. Co-expression of CDCP1 and AXL is often observed in EGFR-mutation-positive tumors, limiting the efficacy of EGFR TKIs. Co-treatment with EGFR TKI and TPX-0005 warrants testing. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Microarray pathway analysis indicated that mitogen-activated protein kinase/extracellular signal-regulated kinase and insulin growth factor 1 signaling pathways were inhibited by small interfering RNA against AT-rich interactive domain 1A in endometrial cancer

PubMed Central

Yang, Ye; Bao, Wei; Sang, Zhengyu; Yang, Yongbing; Lu, Meng; Xi, Xiaowei

2018-01-01

Mutations in the gene encoding AT-rich interactive domain 1A (ARID1A) are frequently observed in endometrial cancer (EC) but the molecular mechanisms linking the genetic changes remain to be fully understood. The present study aimed to elucidate the influence of ARID1A mutations on signaling pathways. Missense, synonymous and nonsense heterozygous ARID1A mutations in the EC HEC-1-A cell line were verified by Sanger sequencing. Mutated ARID1A small interfering RNA was transfected into HEC-1-A cells. Biochemical microarray analysis revealed 13 upregulated pathways, 17 downregulated pathways, 14 significantly affected disease states and functions, 662 upstream and 512 downstream genes in mutated ARID1A-depleted HEC-1-A cells, among which the mitogen-activated protein kinase/extracellular signal-regulated kinase and insulin-like growth factor-1 (IGF1) signaling pathways were the 2 most downregulated pathways. Furthermore, the forkhead box protein O1 pathway was upregulated, while the IGF1 receptor, insulin receptor substrate 1 and phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit b pathways were downregulated. Carcinoma tumorigenesis, tumor cell mitosis and tumor cell death were significantly upregulated disease states and functions, while cell proliferation and tumor growth were significantly downregulated. The results of the present study suggested that ARID1A may be a potential prognostic and therapeutic molecular drug target for the prevention of EC progression. PMID:29399196

Cloning the promoter for transforming growth factor-beta type III receptor. Basal and conditional expression in fetal rat osteoblasts

NASA Technical Reports Server (NTRS)

Ji, C.; Chen, Y.; McCarthy, T. L.; Centrella, M.

1999-01-01

Transforming growth factor-beta binds to three high affinity cell surface molecules that directly or indirectly regulate its biological effects. The type III receptor (TRIII) is a proteoglycan that lacks significant intracellular signaling or enzymatic motifs but may facilitate transforming growth factor-beta binding to other receptors, stabilize multimeric receptor complexes, or segregate growth factor from activating receptors. Because various agents or events that regulate osteoblast function rapidly modulate TRIII expression, we cloned the 5' region of the rat TRIII gene to assess possible control elements. DNA fragments from this region directed high reporter gene expression in osteoblasts. Sequencing showed no consensus TATA or CCAAT boxes, whereas several nuclear factors binding sequences within the 3' region of the promoter co-mapped with multiple transcription initiation sites, DNase I footprints, gel mobility shift analysis, or loss of activity by deletion or mutation. An upstream enhancer was evident 5' proximal to nucleotide -979, and a silencer region occurred between nucleotides -2014 and -2194. Glucocorticoid sensitivity mapped between nucleotides -687 and -253, whereas bone morphogenetic protein 2 sensitivity co-mapped within the silencer region. Thus, the TRIII promoter contains cooperative basal elements and dispersed growth factor- and hormone-sensitive regulatory regions that can control TRIII expression by osteoblasts.

The GHR mutations related to individual’s dwarf

USDA-ARS?s Scientific Manuscript database

Growth hormone (GH) promotes body’s growth through binding with two receptors (GHRs) at the cell surface to interact with Janus kinase and signal transducers and activators of transcription, and then to stimulate metabolic effects and insulin-like growth factor (IGF) synthesis. However, the disorder...

A novel lymphocyte signaling defect: trk A mutation in the syndrome of congenital insensitivity to pain and anhidrosis (CIPA).

PubMed

Melamed, I; Levy, J; Parvari, R; Gelfand, E W

2004-07-01

Congenital insensitivity to pain with anhidrosis is a syndrome characterized by loss of pain and sensation. The condition frequently evolves into deep wounds and prolonged healing times. Anhidrosis is another prominent component of the disorder. Often associated with recurrent episodes of unexplained fever, it can result in patient mortality. Recent investigations point to Trk A, the high affinity receptor for nerve growth factor (NGF), as a candidate for the site of the mutation that causes the disorder. Functional NGF receptors, such as Trk A and the Trk family of tyrosine kinases, are essential for NGF signaling of human lymphocytes. In this study, we demonstrated that the presence of a trk A mutation in patient B cells results in a novel lymphocyte signaling defect. In these B cells, NGF failed to induce Trk A phosphorylation, cytoskeleton assembly, or MAP kinase activation. These abnormalities may explain some of the clinical features of the disease.

Peptide processing and biology in human disease.

PubMed

Kovac, Suzana; Shulkes, Arthur; Baldwin, Graham S

2009-02-01

To describe recent advances in the processing of gastrointestinal hormones, and the consequences for human disease of mutations in the enzymes involved. Although gastrointestinal prohormones were long regarded as devoid of biological activity, recent data indicate that the prohormones for both gastrin and gastrin-releasing peptide are bioactive, through different receptors from the mature hormones. Mutations in the family of prohormone convertases responsible for the initial steps in the processing of gastrointestinal hormones are associated with several different pathophysiological conditions in humans. Human mutational studies, when taken together with the phenotypes observed in mice deficient in the prohormone convertases, emphasize the crucial importance of the processing enzymes in mammalian biology. Although the phenotypes may often be ascribed to defective production of a mature hormone or growth factor, the recognition that the precursors are independently bioactive suggests that the increased precursor concentrations may also contribute to the symptoms. The observation that the precursors often act through different receptors from the mature hormones may permit the development of precursor-selective antagonists for therapeutic use.

Laron syndrome. First report from Greece.

PubMed

Galli-Tsinopoulou, Assimina; Nousia-Arvanitakis, Sanda; Tsinopoulos, Ioannis; Bechlivanides, Christos; Shevah, Orit; Laron, Zvi

2003-01-01

Laron-type dwarfism is an autosomal recessive disorder caused by deletions or mutations of the growth hormone receptor gene. It is characterized by high circulating levels of growth hormone (GH) and low levels of insulin-like growth factor I (IGF-I). Patients are refractory to both endogenous and exogenous GH, and present severe growth retardation and obesity. Therapy with recombinant human insulin-like growth factor-I (rhIGF-I) accelerates linear growth. We describe a 2-year old girl with Laron syndrome, who presented with postnatal growth failure and hypoglycaemic seizures. Her evaluation disclosed high GH values during a glucagon test (peak GH value 170 ng/ml) and very low IGF I value (0.1 ng/ml) with no rise following GH administration. The growth velocity improved considerably with the administration of IGF I. Molecular analysis showed a heterozygous mutation on exon 4 of the GH receptor gene, inherited from the mother, a rather puzzling finding considering the clinical findings in mother and infant. This case constitutes the first report of Laron syndrome from Greece.

Molecular basis for multimerization in the activation of the epidermal growth factor receptor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Yongjian; Bharill, Shashank; Karandur, Deepti

The epidermal growth factor receptor (EGFR) is activated by dimerization, but activation also generates higher-order multimers, whose nature and function are poorly understood. We have characterized ligand-induced dimerization and multimerization of EGFR using single-molecule analysis, and show that multimerization can be blocked by mutations in a specific region of Domain IV of the extracellular module. These mutations reduce autophosphorylation of the C-terminal tail of EGFR and attenuate phosphorylation of phosphatidyl inositol 3-kinase, which is recruited by EGFR. The catalytic activity of EGFR is switched on through allosteric activation of one kinase domain by another, and we show that if thismore » is restricted to dimers, then sites in the tail that are proximal to the kinase domain are phosphorylated in only one subunit. We propose a structural model for EGFR multimerization through self-association of ligand-bound dimers, in which the majority of kinase domains are activated cooperatively, thereby boosting tail phosphorylation.« less

Molecular basis for multimerization in the activation of the epidermal growth factor receptor

DOE PAGES

Huang, Yongjian; Bharill, Shashank; Karandur, Deepti; ...

2016-03-28

The epidermal growth factor receptor (EGFR) is activated by dimerization, but activation also generates higher-order multimers, whose nature and function are poorly understood. We have characterized ligand-induced dimerization and multimerization of EGFR using single-molecule analysis, and show that multimerization can be blocked by mutations in a specific region of Domain IV of the extracellular module. These mutations reduce autophosphorylation of the C-terminal tail of EGFR and attenuate phosphorylation of phosphatidyl inositol 3-kinase, which is recruited by EGFR. The catalytic activity of EGFR is switched on through allosteric activation of one kinase domain by another, and we show that if thismore » is restricted to dimers, then sites in the tail that are proximal to the kinase domain are phosphorylated in only one subunit. We propose a structural model for EGFR multimerization through self-association of ligand-bound dimers, in which the majority of kinase domains are activated cooperatively, thereby boosting tail phosphorylation.« less

Sample features associated with success rates in population-based EGFR mutation testing.

PubMed

Shiau, Carolyn J; Babwah, Jesse P; da Cunha Santos, Gilda; Sykes, Jenna R; Boerner, Scott L; Geddie, William R; Leighl, Natasha B; Wei, Cuihong; Kamel-Reid, Suzanne; Hwang, David M; Tsao, Ming-Sound

2014-07-01

Epidermal growth factor receptor (EGFR) mutation testing has become critical in the treatment of patients with advanced non-small-cell lung cancer. This study involves a large cohort and epidemiologically unselected series of EGFR mutation testing for patients with nonsquamous non-small-cell lung cancer in a North American population to determine sample-related factors that influence success in clinical EGFR testing. Data from consecutive cases of Canadian province-wide testing at a centralized diagnostic laboratory for a 24-month period were reviewed. Samples were tested for exon-19 deletion and exon-21 L858R mutations using a validated polymerase chain reaction method with 1% to 5% detection sensitivity. From 2651 samples submitted, 2404 samples were tested with 2293 samples eligible for analysis (1780 histology and 513 cytology specimens). The overall test-failure rate was 5.4% with overall mutation rate of 20.6%. No significant differences in the failure rate, mutation rate, or mutation type were found between histology and cytology samples. Although tumor cellularity was significantly associated with test-success or mutation rates in histology and cytology specimens, respectively, mutations could be detected in all specimen types. Significant rates of EGFR mutation were detected in cases with thyroid transcription factor (TTF)-1-negative immunohistochemistry (6.7%) and mucinous component (9.0%). EGFR mutation testing should be attempted in any specimen, whether histologic or cytologic. Samples should not be excluded from testing based on TTF-1 status or histologic features. Pathologists should report the amount of available tumor for testing. However, suboptimal samples with a negative EGFR mutation result should be considered for repeat testing with an alternate sample.

G protein-coupled receptor mutations and human genetic disease.

PubMed

Thompson, Miles D; Hendy, Geoffrey N; Percy, Maire E; Bichet, Daniel G; Cole, David E C

2014-01-01

Genetic variations in G protein-coupled receptor genes (GPCRs) disrupt GPCR function in a wide variety of human genetic diseases. In vitro strategies and animal models have been used to identify the molecular pathologies underlying naturally occurring GPCR mutations. Inactive, overactive, or constitutively active receptors have been identified that result in pathology. These receptor variants may alter ligand binding, G protein coupling, receptor desensitization and receptor recycling. Receptor systems discussed include rhodopsin, thyrotropin, parathyroid hormone, melanocortin, follicle-stimulating hormone (FSH), luteinizing hormone, gonadotropin-releasing hormone (GNRHR), adrenocorticotropic hormone, vasopressin, endothelin-β, purinergic, and the G protein associated with asthma (GPRA or neuropeptide S receptor 1 (NPSR1)). The role of activating and inactivating calcium-sensing receptor (CaSR) mutations is discussed in detail with respect to familial hypocalciuric hypercalcemia (FHH) and autosomal dominant hypocalemia (ADH). The CASR mutations have been associated with epilepsy. Diseases caused by the genetic disruption of GPCR functions are discussed in the context of their potential to be selectively targeted by drugs that rescue altered receptors. Examples of drugs developed as a result of targeting GPCRs mutated in disease include: calcimimetics and calcilytics, therapeutics targeting melanocortin receptors in obesity, interventions that alter GNRHR loss from the cell surface in idiopathic hypogonadotropic hypogonadism and novel drugs that might rescue the P2RY12 receptor congenital bleeding phenotype. De-orphanization projects have identified novel disease-associated receptors, such as NPSR1 and GPR35. The identification of variants in these receptors provides genetic reagents useful in drug screens. Discussion of the variety of GPCRs that are disrupted in monogenic Mendelian disorders provides the basis for examining the significance of common pharmacogenetic variants.

The Dwarfs of Sindh: severe growth hormone (GH) deficiency caused by a mutation in the GH-releasing hormone receptor gene.

PubMed

Baumann, G; Maheshwari, H

1997-11-01

We report the discovery of a cluster of severe familial dwarfism in two villages in the Province of Sindh in Pakistan. Dwarfism is proportionate and occurs in members of a kindred with a high degree of consanguinity. Only the last generation is affected, with the oldest dwarf being 28 years old. The mode of inheritance is autosomal recessive. Phenotype analysis and endocrine testing revealed isolated growth hormone deficiency (GHD) as the reason for growth failure. Linkage analysis for the loci of several candidate genes yielded a high lod score for the growth hormone-releasing hormone receptor (GHRH-R) locus on chromosome 7. Amplification and sequencing of the GHRH-R gene in affected subjects demonstrated an amber nonsense mutation (GAG-->TAG; Glu50-->Stop) in exon 3. The mutation, in its homozygous form, segregated 100% with the dwarf phenotype. It predicts a truncation of the GHRH-R in its extracellular domain, which is likely to result in a severely disabled or non-existent receptor protein. Subjects who are heterozygous for the mutation show mild biochemical abnormalities in the growth hormone-releasing hormone (GHRH)--growth hormone--insulin-like growth factor axis, but have only minimal or no growth retardation. The occurrence of an offspring of two dwarfed parents indicates that the GHRH-R is not necessary for fertility in either sex. We conclude that Sindh dwarfism is caused by an inactivating mutation in the GHRH-R gene, resulting in the inability to transmit a GHRH signal and consequent severe isolated GHD.

The influence of allosteric modulators and transmembrane mutations on desensitisation and activation of α7 nicotinic acetylcholine receptors

PubMed Central

Chatzidaki, Anna; D'Oyley, Jarryl M.; Gill-Thind, JasKiran K.; Sheppard, Tom D.; Millar, Neil S.

2015-01-01

Acetylcholine activates nicotinic acetylcholine receptors (nAChRs) by binding at an extracellular orthosteric site. Previous studies have described several positive allosteric modulators (PAMs) that are selective for homomeric α7 nAChRs. These include type I PAMs, which exert little or no effect on the rate of receptor desensitisation, and type II PAMs, which cause a dramatic loss of agonist-induced desensitisation. Here we report evidence that transmembrane mutations in α7 nAChRs have diverse effects on receptor activation and desensitisation by allosteric ligands. It has been reported previously that the L247T mutation, located toward the middle of the second transmembrane domain (at the 9′ position), confers reduced levels of desensitisation. In contrast, the M260L mutation, located higher up in the TM2 domain (at the 22′ position), does not show any difference in desensitisation compared to wild-type receptors. We have found that in receptors containing the L247T mutation, both type I PAMs and type II PAMs are converted into non-desensitising agonists. In contrast, in receptors containing the M260L mutation, this effect is seen only with type II PAMs. These findings, indicating that the M260L mutation has a selective effect on type II PAMs, have been confirmed both with previously described PAMs and also with a series of novel α7-selective PAMs. The novel PAMs examined in this study have close chemical similarity but diverse pharmacological properties. For example, they include compounds displaying effects on receptor desensitisation that are typical of classical type I and type II PAMs but, in addition, they include compounds with intermediate properties. PMID:25998276

The influence of allosteric modulators and transmembrane mutations on desensitisation and activation of α7 nicotinic acetylcholine receptors.

PubMed

Chatzidaki, Anna; D'Oyley, Jarryl M; Gill-Thind, JasKiran K; Sheppard, Tom D; Millar, Neil S

2015-10-01

Acetylcholine activates nicotinic acetylcholine receptors (nAChRs) by binding at an extracellular orthosteric site. Previous studies have described several positive allosteric modulators (PAMs) that are selective for homomeric α7 nAChRs. These include type I PAMs, which exert little or no effect on the rate of receptor desensitisation, and type II PAMs, which cause a dramatic loss of agonist-induced desensitisation. Here we report evidence that transmembrane mutations in α7 nAChRs have diverse effects on receptor activation and desensitisation by allosteric ligands. It has been reported previously that the L247T mutation, located toward the middle of the second transmembrane domain (at the 9' position), confers reduced levels of desensitisation. In contrast, the M260L mutation, located higher up in the TM2 domain (at the 22' position), does not show any difference in desensitisation compared to wild-type receptors. We have found that in receptors containing the L247T mutation, both type I PAMs and type II PAMs are converted into non-desensitising agonists. In contrast, in receptors containing the M260L mutation, this effect is seen only with type II PAMs. These findings, indicating that the M260L mutation has a selective effect on type II PAMs, have been confirmed both with previously described PAMs and also with a series of novel α7-selective PAMs. The novel PAMs examined in this study have close chemical similarity but diverse pharmacological properties. For example, they include compounds displaying effects on receptor desensitisation that are typical of classical type I and type II PAMs but, in addition, they include compounds with intermediate properties. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Analysis of corkscrew signaling in the Drosophila epidermal growth factor receptor pathway during myogenesis.

PubMed

Johnson Hamlet, M R; Perkins, L A

2001-11-01

The Drosophila nonreceptor protein tyrosine phosphatase, Corkscrew (Csw), functions positively in multiple receptor tyrosine kinase (RTK) pathways, including signaling by the epidermal growth factor receptor (EGFR). Detailed phenotypic analyses of csw mutations have revealed that Csw activity is required in many of the same developmental processes that require EGFR function. However, it is still unclear where in the signaling hierarchy Csw functions relative to other proteins whose activities are also required downstream of the receptor. To address this issue, genetic interaction experiments were performed to place csw gene activity relative to the EGFR, spitz (spi), rhomboid (rho), daughter of sevenless (DOS), kinase-suppressor of ras (ksr), ras1, D-raf, pointed (pnt), and moleskin. We followed the EGFR-dependent formation of VA2 muscle precursor cells as a sensitive assay for these genetic interaction studies. First, we established that Csw has a positive function during mesoderm development. Second, we found that tissue-specific expression of a gain-of-function csw construct rescues loss-of-function mutations in other positive signaling genes upstream of rolled (rl)/MAPK in the EGFR pathway. Third, we were able to infer levels of EGFR signaling in various mutant backgrounds during myogenesis. This work extends previous studies of Csw during Torso and Sevenless RTK signaling to include an in-depth analysis of the role of Csw in the EGFR signaling pathway.

Analysis of corkscrew signaling in the Drosophila epidermal growth factor receptor pathway during myogenesis.

PubMed Central

Johnson Hamlet, M R; Perkins, L A

2001-01-01

The Drosophila nonreceptor protein tyrosine phosphatase, Corkscrew (Csw), functions positively in multiple receptor tyrosine kinase (RTK) pathways, including signaling by the epidermal growth factor receptor (EGFR). Detailed phenotypic analyses of csw mutations have revealed that Csw activity is required in many of the same developmental processes that require EGFR function. However, it is still unclear where in the signaling hierarchy Csw functions relative to other proteins whose activities are also required downstream of the receptor. To address this issue, genetic interaction experiments were performed to place csw gene activity relative to the EGFR, spitz (spi), rhomboid (rho), daughter of sevenless (DOS), kinase-suppressor of ras (ksr), ras1, D-raf, pointed (pnt), and moleskin. We followed the EGFR-dependent formation of VA2 muscle precursor cells as a sensitive assay for these genetic interaction studies. First, we established that Csw has a positive function during mesoderm development. Second, we found that tissue-specific expression of a gain-of-function csw construct rescues loss-of-function mutations in other positive signaling genes upstream of rolled (rl)/MAPK in the EGFR pathway. Third, we were able to infer levels of EGFR signaling in various mutant backgrounds during myogenesis. This work extends previous studies of Csw during Torso and Sevenless RTK signaling to include an in-depth analysis of the role of Csw in the EGFR signaling pathway. PMID:11729154

Differential regulation of insulin-like growth factor-I receptor gene expression by wild type and mutant androgen receptor in prostate cancer cells.

PubMed

Schayek, Hagit; Seti, Hila; Greenberg, Norman M; Sun, Shihua; Werner, Haim; Plymate, Stephen R

2010-07-29

The progression of prostate cancer from an organ-confined, androgen-sensitive disease to a metastatic one is associated with dysregulation of androgen receptor (AR)-regulated target genes and with a decrease in insulin-like growth factor-I receptor (IGF-IR) expression. To investigate the differential effects of wild type (wt) and mutant AR on IGF-IR levels we employed a series of isogenic prostate-derived cell lines and human xenografts. We show that basal and phosphorylated IGF-IR levels progressively decreased as prostate cancer cells became more tumorigenic and metastatic. In addition, we show that wt, but not mutant, AR along with dihydrotestosterone treatment increased IGF-IR promoter activity and endogenous IGF-IR levels. ChIP analysis show enhanced AR binding to the IGF-IR promoter in AR-overexpressing cells. Finally, wt AR-overexpressing cells display an enhanced proliferation rate. In summary, we provide evidence that activated wt AR enhances IGF-IR transcription in prostate cancer cells via a mechanism that involves AR binding to the IGF-IR promoter. AR mutations alter the ability of the mutated protein to regulate IGF-IR expression. Our results suggest that prostate cancer progression is associated with a decrease in IGF-IR expression that could be the result of impaired ability of AR to stimulate IGF-IR gene expression. 2010 Elsevier Ireland Ltd. All rights reserved.

Differential regulation of insulin-like growth factor-I receptor gene expression by wild type and mutant androgen receptor in prostate cancer cells

PubMed Central

Schayek, Hagit; Seti, Hila; Greenberg, Norman M.; Sun, Shihua; Werner, Haim; Plymate, Stephen R.

2010-01-01

The progression of prostate cancer from an organ-confined, androgen-sensitive disease to a metastatic one is associated with dysregulation of androgen receptor (AR)-regulated target genes and with a decrease in insulin-like growth factor-I receptor (IGF-IR) expression. To investigate the differential effects of wild type (wt) and mutant AR on IGF-IR levels we employed a series of isogenic prostate-derived cell lines and human xenografts. We show that basal and phosphorylated IGF-IR levels progressively decreased as prostate cancer cells became more tumorigenic and metastatic. In addition, we show that wt, but not mutant, AR along with dihydrotestosterone treatment increased IGF-IR promoter activity and endogenous IGF-IR levels. ChIP analysis show enhanced AR binding to the IGF-IR promoter in AR-overexpressing cells. Finally, wt AR-overexpressing cells display an enhanced proliferation rate. In summary, we provide evidence that activated wt AR enhances IGF-IR transcription in prostate cancer cells via a mechanism that involves AR binding to the IGF-IR promoter. AR mutations alter the ability of the mutated protein to regulate IGF-IR expression. Our results suggest that prostate cancer progression is associated with a decrease in IGF-IR expression that could be the result of impaired ability of AR to stimulate IGF-IR gene expression. PMID:20417685

Broad Detection of Alterations Predicted to Confer Lack of Benefit From EGFR Antibodies or Sensitivity to Targeted Therapy in Advanced Colorectal Cancer.

PubMed

Rankin, Andrew; Klempner, Samuel J; Erlich, Rachel; Sun, James X; Grothey, Axel; Fakih, Marwan; George, Thomas J; Lee, Jeeyun; Ross, Jeffrey S; Stephens, Philip J; Miller, Vincent A; Ali, Siraj M; Schrock, Alexa B

2016-09-28

A KRAS mutation represented the first genomic biomarker to predict lack of benefit from anti-epidermal growth factor receptor (EGFR) antibody therapy in advanced colorectal cancer (CRC). Expanded RAS testing has further refined the treatment approach, but understanding of genomic alterations underlying primary and acquired resistance is limited and further study is needed. We prospectively analyzed 4,422 clinical samples from patients with advanced CRC, using hybrid-capture based comprehensive genomic profiling (CGP) at the request of the individual treating physicians. Comparison with prior molecular testing results, when available, was performed to assess concordance. We identified a RAS/RAF pathway mutation or amplification in 62% of cases, including samples harboring KRAS mutations outside of the codon 12/13 hotspot region in 6.4% of cases. Among cases with KRAS non-codon 12/13 alterations for which prior test results were available, 79 of 90 (88%) were not identified by focused testing. Of 1,644 RAS/RAF wild-type cases analyzed by CGP, 31% harbored a genomic alteration (GA) associated with resistance to anti-EGFR therapy in advanced CRC including mutations in PIK3CA, PTEN, EGFR, and ERBB2. We also identified other targetable GA, including novel kinase fusions, receptor tyrosine kinase amplification, activating point mutations, as well as microsatellite instability. Extended genomic profiling reliably detects alterations associated with lack of benefit to anti-EGFR therapy in advanced CRC, while simultaneously identifying alterations potentially important in guiding treatment. The use of CGP during the course of clinical care allows for the refined selection of appropriate targeted therapies and clinical trials, increasing the chance of clinical benefit and avoiding therapeutic futility. Comprehensive genomic profiling (CGP) detects diverse genomic alterations associated with lack of benefit to anti-epidermal growth factor receptor therapy in advanced colorectal cancer (CRC), as well as targetable alterations in many other genes. This includes detection of a broad spectrum of activating KRAS alterations frequently missed by focused molecular hotspot testing, as well as other RAS/RAF pathway alterations, mutations shown to disrupt antibody binding, RTK activating point mutations, amplifications, and rearrangements, and activating alterations in downstream effectors including PI3K and MEK1. The use of CGP in clinical practice is critical to guide appropriate selection of targeted therapies for patients with advanced CRC. ©AlphaMed Press.

Receptor Signaling Directs Global Recruitment of Pre-existing Transcription Factors to Inducible Elements.

PubMed

Cockerill, Peter N

2016-12-01

Gene expression programs are largely regulated by the tissue-specific expression of lineage-defining transcription factors or by the inducible expression of transcription factors in response to specific stimuli. Here I will review our own work over the last 20 years to show how specific activation signals also lead to the wide-spread re-distribution of pre-existing constitutive transcription factors to sites undergoing chromatin reorganization. I will summarize studies showing that activation of kinase signaling pathways creates open chromatin regions that recruit pre-existing factors which were previously unable to bind to closed chromatin. As models I will draw upon genes activated or primed by receptor signaling in memory T cells, and genes activated by cytokine receptor mutations in acute myeloid leukemia. I also summarize a hit-and-run model of stable epigenetic reprograming in memory T cells, mediated by transient Activator Protein 1 (AP-1) binding, which enables the accelerated activation of inducible enhancers.

A novel MPL point mutation resulting in thrombopoietin-independent activation.

PubMed

Abe, M; Suzuki, K; Inagaki, O; Sassa, S; Shikama, H

2002-08-01

Thrombopoietin (TPO) and its receptor (MPL) are important regulators of megakaryopoiesis. MPL belongs to a cytokine receptor superfamily. To date, all constitutively active MPL mutants have been artificially constructed with amino acid substitutions in the transmembrane domain or extracellular domain of the protein, and they activate signal transduction pathways in Ba/F3 cells that can also be activated by the normal MPL. In this paper, we report a novel spontaneously occurring mutation of MPL, with an amino acid substitution of Trp(508) to Ser(508) in the intracellular domain of MPL, that induces the factor-independent growth of Ba/F3 cells. Examination of intracellular signaling pathways demonstrated that the mutant MPL protein constitutively activates three distinct signaling pathways, SHC-Ras-Raf-MAPK/JNK, JAK-STAT, and PI3K-Akt-Bad.

AIP mutations impair AhR signaling in pituitary adenoma patients fibroblasts and in GH3 cells.

PubMed

Lecoq, Anne-Lise; Viengchareun, Say; Hage, Mirella; Bouligand, Jérôme; Young, Jacques; Boutron, Audrey; Zizzari, Philippe; Lombès, Marc; Chanson, Philippe; Kamenický, Peter

2016-05-01

Germline mutations in the aryl hydrocarbon receptor-interacting protein (AIP) gene predispose humans to pituitary adenomas through unknown molecular mechanisms. The best-known interacting partner of AIP is the aryl hydrocarbon receptor (AhR), a transcription factor that mediates the effects of xenobiotics implicated in carcinogenesis. As 75% of AIP mutations disrupt the physical and/or functional interaction with AhR, we postulated that the tumorigenic potential of AIP mutations might result from altered AhR signaling. We evaluated the impact of AIP mutations on the AhR signaling pathway, first in fibroblasts from AIP-mutated patients with pituitary adenomas, by comparison with fibroblasts from healthy subjects, then in transfected pituitary GH3 cells. The AIP protein level in mutated fibroblasts was about half of that in cells from healthy subjects, but AhR expression was unaffected. Gene expression analyses showed significant modifications in the expression of the AhR target genes CYP1B1 and AHRR in AIP-mutated fibroblasts, both before and after stimulation with the endogenous AhR ligand kynurenine. Kynurenine increased Cyp1b1 expression to a greater extent in GH3 cells overexpressing wild type compared with cells expressing mutant AIP Knockdown of endogenous Aip in these cells attenuated Cyp1b1 induction by the AhR ligand. Both mutant AIP expression and knockdown of endogenous Aip affected the kynurenine-dependent GH secretion of GH3 cells. This study of human fibroblasts bearing endogenous heterozygous AIP mutations and transfected pituitary GH3 cells shows that AIP mutations affect the AIP protein level and alter AhR transcriptional activity in a gene- and tissue-dependent manner. © 2016 Society for Endocrinology.

Novel FGFR1 mutations in Kallmann syndrome and normosmic idiopathic hypogonadotropic hypogonadism: evidence for the involvement of an alternatively spliced isoform.

PubMed

Gonçalves, Catarina; Bastos, Margarida; Pignatelli, Duarte; Borges, Teresa; Aragüés, José M; Fonseca, Fernando; Pereira, Bernardo D; Socorro, Sílvia; Lemos, Manuel C

2015-11-01

To determine the prevalence of fibroblast growth factor receptor 1 (FGFR1) mutations and their predicted functional consequences in patients with idiopathic hypogonadotropic hypogonadism (IHH). Cross-sectional study. Multicentric. Fifty unrelated patients with IHH (21 with Kallmann syndrome and 29 with normosmic IHH). None. Patients were screened for mutations in FGFR1. The functional consequences of mutations were predicted by in silico structural and conservation analysis. Heterozygous FGFR1 mutations were identified in six (12%) kindreds. These consisted of frameshift mutations (p.Pro33-Alafs*17 and p.Tyr654*) and missense mutations in the signal peptide (p.Trp4Cys), in the D1 extracellular domain (p.Ser96Cys) and in the cytoplasmic tyrosine kinase domain (p.Met719Val). A missense mutation was identified in the alternatively spliced exon 8A (p.Ala353Thr) that exclusively affects the D3 extracellular domain of FGFR1 isoform IIIb. Structure-based and sequence-based prediction methods and the absence of these variants in 200 normal controls were all consistent with a critical role for the mutations in the activity of the receptor. Oligogenic inheritance (FGFR1/CHD7/PROKR2) was found in one patient. Two FGFR1 isoforms, IIIb and IIIc, result from alternative splicing of exons 8A and 8B, respectively. Loss-of-function of isoform IIIc is a cause of IHH, whereas isoform IIIb is thought to be redundant. Ours is the first report of normosmic IHH associated with a mutation in the alternatively spliced exon 8A and suggests that this disorder can be caused by defects in either of the two alternatively spliced FGFR1 isoforms. Copyright © 2015 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Context-Dependent Sensitivity to Mutations Disrupting the Structural Integrity of Individual EGF Repeats in the Mouse Notch Ligand DLL1

PubMed Central

Schuster-Gossler, Karin; Cordes, Ralf; Müller, Julia; Geffers, Insa; Delany-Heiken, Patricia; Taft, Manuel; Preller, Matthias; Gossler, Achim

2016-01-01

The highly conserved Notch-signaling pathway mediates cell-to-cell communication and is pivotal for multiple developmental processes and tissue homeostasis in adult organisms. Notch receptors and their ligands are transmembrane proteins with multiple epidermal-growth-factor-like (EGF) repeats in their extracellular domains. In vitro the EGF repeats of mammalian ligands that are essential for Notch activation have been defined. However, in vivo the significance of the structural integrity of each EGF repeat in the ligand ectodomain for ligand function is still unclear. Here, we analyzed the mouse Notch ligand DLL1. We expressed DLL1 proteins with mutations disrupting disulfide bridges in each individual EGF repeat from single-copy transgenes in the HPRT locus of embryonic stem cells. In Notch transactivation assays all mutations impinged on DLL1 function and affected both NOTCH1 and NOTCH2 receptors similarly. An allelic series in mice that carried the same point mutations in endogenous Dll1, generated using a mini-gene strategy, showed that early developmental processes depending on DLL1-mediated NOTCH activation were differently sensitive to mutation of individual EGF repeats in DLL1. Notably, some mutations affected only somite patterning and resulted in vertebral column defects resembling spondylocostal dysostosis. In conclusion, the structural integrity of each individual EGF repeat in the extracellular domain of DLL1 is necessary for full DLL1 activity, and certain mutations in Dll1 might contribute to spondylocostal dysostosis in humans. PMID:26801181

Deletion of thyrotropin receptor residue Asp403 in a hyperfunctioning thyroid nodule provides insight into the role of the ectodomain in ligand-induced receptor activation.

PubMed

Nishihara, E; Chen, C-R; Mizutori-Sasai, Y; Ito, M; Kubota, S; Amino, N; Miyauchi, A; Rapoport, B

2012-01-01

Somatic mutations of the TSH receptor (TSHR) gene are the main cause of autonomously functioning thyroid nodules. Except for mutations in ectodomain residue S281, all of the numerous reported activating mutations are in the TSHR membrane-spanning region. Here, we describe a patient with a toxic adenoma with a novel heterozygous somatic mutation caused by deletion of ectodomain residue Asp403 (Del-D403). Subsequent in vitro functional studies of the Del-D403 TSHR mutation demonstrated greatly increased ligand-independent constitutive activity, 8-fold above that of the wild-type TSHR. TSH stimulation had little further effect, indicating that the mutation produced near maximal activation of the receptor. In summary, we report only the second TSHR ectodomain activating mutation (and the first ectodomain deletion mutation) responsible for development of a thyroid toxic adenoma. Because Del-D403 causes near maximal activation, our finding provides novel insight into TSHR structure and function; residue D403 is more likely to be involved in the ligand-mediated activating pathway than in the ectodomain inverse agonist property.

Apatinib in the treatment of advanced lung adenocarcinoma with KRAS mutation.

PubMed

Zeng, Da-Xiong; Wang, Chang-Guo; Huang, Jian-An; Jiang, Jun-Hong

2017-01-01

Activating KRAS mutations in lung adenocarcinoma are characterized with treatment resistance and poor prognosis. As a small molecule inhibitor of vascular endothelial growth factor receptor-2 (VEGFR-2) tyrosine kinase, apatinib has been proven successful in advanced gastric cancer and breast cancer. In this study, we show the result of apatinib as salvage treatment in lung adenocarcinoma patients with KRAS mutation. Four advanced lung adenocarcinoma patients with KRAS mutation were orally administered apatinib (250 mg/d) after second-line treatment. One patient showed progressive disease, while 3 patients showed stable disease response to apatinib, with a median progression-free survival (PFS) of 3.8 months (1.5-5.5 months). The main toxicities were hoarseness and hemoptysis, which were manageable. Therefore, apatinib might be an optional choice for advanced lung adenocarcinoma patients with KRAS mutation in post second-line treatment.

AMPA receptor desensitization mutation results in severe developmental phenotypes and early postnatal lethality

PubMed Central

Christie, Louisa A.; Russell, Theron A.; Xu, Jian; Wood, Lydia; Shepherd, Gordon M. G.; Contractor, Anis

2010-01-01

AMPA (α-amino-3-hydroxy-5-methyl-4-isoxazole-propionate) recep-tors desensitize rapidly and completely in the continued presence of their endogenous ligand glutamate; however, it is not clear what role AMPA receptor desensitization plays in the brain. We generated a knock-in mouse in which a single amino acid residue, which controls desensitization, was mutated in the GluA2 (GluR2) receptor subunit (GluA2L483Y). This mutation was homozygous lethal. However, mice carrying a single mutated allele, GluA2L483Y/wt, survived past birth, but displayed severe and progressive neurological deficits including seizures and, ultimately, increased mortality. The expression of the AMPA receptor subunits GluA1 and GluA2 was decreased, whereas NMDA receptor protein expression was increased in GluA2L483Y/wt mice. Despite this, basal synaptic transmission and plasticity in the hippocampus were largely unaffected, suggesting that neurons preferentially target receptors to synapses to normalize synaptic weight. We found no gross neuroanatomical alterations in GluA2L483Y/wt mice. Moreover, there was no accumulation of AMPA receptor subunits in intracellular compartments, suggesting that folding and assembly of AMPA receptors are not affected by this mutation. Interestingly, EPSC paired pulse ratios in the CA1 were enhanced without a change in synaptic release probability, demonstrating that postsynaptic receptor properties can contribute to facilitation. The dramatic phenotype observed in this study by the introduction of a single amino acid change demonstrates an essential role in vivo for AMPA receptor desensitization. PMID:20439731

Comparison of cross-platform technologies for EGFR T790M testing in patients with non-small cell lung cancer

PubMed Central

Li, Xuefei; Zhou, Caicun

2017-01-01

Somatic mutations in the gene encoding epidermal growth factor receptor (EGFR) play an important role in determining targeted treatment modalities in non-small cell lung cancer (NSCLC). The EGFR T790M mutation emerges in approximately 50% of cases who acquire resistance to tyrosine kinase inhibitors. Detecting EGFR T790M mutation in tumor tissue is challenging due to heterogeneity of the tumor, low abundance of the mutation and difficulty for re-biopsy in patients with advanced disease. Alternatively, circulating tumor DNA (ctDNA) has been proposed as a non-invasive method for mutational analysis. The presence of EGFR mutations in ctDNA predicts response to the EGFR TKIs in the first-line setting. Molecular testing is now considered a standard care for NSCLC. The advent of standard commercially available kits and targeted mutational analysis has revolutionized the accuracy of mutation detection platforms for detection of EGFR mutations. Our review provides an overview of various commonly used platforms for detecting EGFR T790M mutation in tumor tissue and plasma. PMID:29246024

Tumour necrosis factor receptor trafficking dysfunction opens the TRAPS door to pro-inflammatory cytokine secretion

PubMed Central

Turner, Mark D.; Chaudhry, Anupama; Nedjai, Belinda

2011-01-01

Cytokines are secreted from macrophages and other cells of the immune system in response to pathogens. Additionally, in autoinflammatory diseases cytokine secretion occurs in the absence of pathogenic stimuli. In the case of TRAPS [TNFR (tumour necrosis factor receptor)-associated periodic syndrome], inflammatory episodes result from mutations in the TNFRSF1A gene that encodes TNFR1. This work remains controversial, however, with at least three distinct separate mechanisms of receptor dysfunction having been proposed. Central to these hypotheses are the NF-κB (nuclear factor κB) and MAPK (mitogen-activated protein kinase) families of transcriptional activators that are able to up-regulate expression of a number of genes, including pro-inflammatory cytokines. The present review examines each proposed mechanism of TNFR1 dysfunction, and addresses how these processes might ultimately impact upon cytokine secretion and disease pathophysiology. PMID:22115362

Rapid point-of-care testing for epidermal growth factor receptor gene mutations in patients with lung cancer using cell-free DNA from cytology specimen supernatants.

PubMed

Asaka, Shiho; Yoshizawa, Akihiko; Saito, Kazusa; Kobayashi, Yukihiro; Yamamoto, Hiroshi; Negishi, Tatsuya; Nakata, Rie; Matsuda, Kazuyuki; Yamaguchi, Akemi; Honda, Takayuki

2018-06-01

Epidermal growth factor receptor (EGFR) mutations are associated with responses to EGFR tyrosine kinase inhibitors (EGFR-TKIs) in non-small-cell lung cancer (NSCLC). Our previous study revealed a rapid point-of-care system for detecting EGFR mutations. This system analyzes cell pellets from cytology specimens using droplet-polymerase chain reaction (d-PCR), and has a reaction time of 10 min. The present study aimed to validate the performance of the EGFR d-PCR assay using cell-free DNA (cfDNA) from supernatants obtained from cytology specimens. Assay results from cfDNA supernatant analyses were compared with those from cell pellets for 90 patients who were clinically diagnosed with, or suspected of having, lung cancer (80 bronchial lavage fluid samples, nine pleural effusion samples and one spinal fluid sample). EGFR mutations were identified in 12 and 15 cases using cfDNA supernatants and cell pellets, respectively. The concordance rates between cfDNA-supernatant and cell‑pellet assay results were 96.7% [kappa coefficient (K)=0.87], 98.9% (K=0.94), 98.9% (K=0.79) and 98.9% (K=0.79) for total EGFR mutations, L858R, E746_A750del and T790M, respectively. All 15 patients with EGFR mutation-positive results, as determined by EGFR d-PCR assay using cfDNA supernatants or cell pellets, also displayed positive results by conventional EGFR assays using tumor tissue or cytology specimens. Notably, EGFR mutations were even detected in five cfDNA supernatants for which the cytological diagnoses of the corresponding cell pellets were 'suspicious for malignancy', 'atypical' or 'negative for malignancy.' In conclusion, this rapid point-of-care system may be considered a promising novel screening method that may enable patients with NSCLC to receive EGFR-TKI therapy more rapidly, whilst also reserving cell pellets for additional morphological and molecular analyses.

Comparison of targeted next-generation sequencing with conventional sequencing for predicting the responsiveness to epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) therapy in never-smokers with lung adenocarcinoma.

PubMed

Han, Ji-Youn; Kim, Sun Hye; Lee, Yeon-Su; Lee, Seung-Youn; Hwang, Jung-Ah; Kim, Jin Young; Yoon, Sung Jin; Lee, Geon Kook

2014-08-01

To investigate the clinical utility of targeted next-generation sequencing (NGS) for predicting the responsiveness to epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI) therapy, we compared the efficacy with conventional sequencing in never-smokers with lung adenocarcinoma (NSLAs). We obtained DNA from 48 NSLAs who received gefitinib or erlotinib for their recurrent disease after surgery. Sanger sequencing and peptide nucleic acid clamp polymerase chain reaction (PCR) were used to analyze EGFR, KRAS, BRAF, and PIK3CA mutations. We analyzed ALK, RET, and ROS1 rearrangements by fluorescent in situ hybridization or reverse transcriptase-PCR and quantitative real-time PCR. After molecular screening, Ion Torrent NGS was performed in 31 cases harboring only EGFR exon 19 deletions (19DEL), an L858R mutation, or none of the above mutations. The 31 samples were divided into four groups: (1) responders to EGFR-TKIs with only 19DEL or L858R (n=15); (2) primary resistance to EGFR-TKI with only 19DEL or L858R (n=4); (3) primary resistance to EGFR-TKI without any mutations (n=8); (4) responders to EGFR-TKI without any mutations (n=4). With NGS, all conventionally detected mutations were confirmed except for one L858R in group 2. Additional uncovered predictive mutations with NGS included one PIK3CA E542K in group 2, two KRAS (G12V and G12D), one PIK3CA E542K, one concomitant PIK3CA and EGFR L858R in group 3, and one EGFR 19DEL in group 4. Targeted NGS provided a more accurate and clinically useful molecular classification of NSLAs. It may improve the efficacy of EGFR-TKI therapy in lung cancer. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Congenital insensitivity to pain with anhidrosis (CIPA) in Israeli-Bedouins: genetic heterogeneity, novel mutations in the TRKA/NGF receptor gene, clinical findings, and results of nerve conduction studies.

PubMed

Shatzky, S; Moses, S; Levy, J; Pinsk, V; Hershkovitz, E; Herzog, L; Shorer, Z; Luder, A; Parvari, R

2000-06-19

Congenital insensitivity to pain with anhidrosis (CIPA), a rare and severe disorder, comprises absence of sensation to noxious stimuli, inability to sweat, and recurrent episodes of hyperthermia. It has a relatively high prevalence in the consanguineous Israeli-Bedouins. Clinical studies of 28 patients are reported here. Using the linkage analysis approach, we linked the disease in 9 of 10 unrelated Israeli-Bedouin families with CIPA to the TrkA gene, which encodes the receptor for nerve growth factor. In one family, linkage was excluded, implying that another gene, yet unidentified, is involved. Two new mutations in the tyrosine kinase domain of the TrkA gene were identified in our CIPA patients: a 1926-ins-T in most of the southern Israeli-Negev CIPA patients, and a Pro- 689-Leu mutation in a different isolate of Bedouins in northern Israel. Eight prenatal diagnoses were made in the southern Israeli-Negev Bedouins, two by linkage analysis and six by checking directly for the 1926-ins-T mutation. Three polymorphisms in the TrkA protein kinase encoding domain were also observed. Copyright 2000 Wiley-Liss, Inc.

Sequence analysis of the Ras-MAPK pathway genes SOS1, EGFR & GRB2 in silver foxes (Vulpes vulpes): candidate genes for hereditary hyperplastic gingivitis.

PubMed

Clark, Jo-Anna B J; Tully, Sara J; Dawn Marshall, H

2014-12-01

Hereditary hyperplastic gingivitis (HHG) is an autosomal recessive disease that presents with progressive gingival proliferation in farmed silver foxes. Hereditary gingival fibromatosis (HGF) is an analogous condition in humans that is genetically heterogeneous with several known autosomal dominant loci. For one locus the causative mutation is in the Son of sevenless homologue 1 (SOS1) gene. For the remaining loci, the molecular mechanisms are unknown but Ras pathway involvement is suspected. Here we compare sequences for the SOS1 gene, and two adjacent genes in the Ras pathway, growth receptor bound protein 2 (GRB2) and epidermal growth factor receptor (EGFR), between HHG-affected and unaffected foxes. We conclude that the known HGF causative mutation does not cause HHG in foxes, nor do the coding regions or intron-exon boundaries of these three genes contain any candidate mutations for fox gum disease. Patterns of molecular evolution among foxes and other mammals reflect high conservation and strong functional constraints for SOS1 and GRB2 but reveal a lineage-specific pattern of variability in EGFR consistent with mutational rate differences, relaxed functional constraints, and possibly positive selection.

Alu-mediated recombination defect in IGF1R: haploinsufficiency in a patient with short stature.

PubMed

Harmel, Eva-Maria; Binder, Gerhard; Barnikol-Oettler, Anja; Caliebe, Janina; Kiess, Wieland; Losekoot, Monique; Ranke, Michael B; Rappold, Gudrun A; Schlicke, Marina; Stobbe, Heike; Wit, Jan M; Pfäffle, Roland; Klammt, Jürgen

2013-01-01

The insulin-like growth factor (IGF) receptor (IGF1R) is essential for normal development and growth. IGF1R mutations cause IGF-1 resistance resulting in intrauterine and postnatal growth failure. The phenotypic spectrum related to IGF1R mutations remains to be fully understood. Auxological and endocrinological data of a patient identified previously were assessed. The patient's fibroblasts were studied to characterize the IGF1R deletion, mRNA fate, protein expression and signalling capabilities. The boy, who carries a heterozygous IGF1R exon 6 deletion caused by Alu element-mediated recombination and a heterozygous SHOX variant (p.Met240Ile), was born appropriate for gestational age but developed proportionate short stature postnatally. IGF-1 levels were low-normal. None of the stigmata associated with SHOX deficiency or sporadically observed in IGF1R mutation carriers were present. Nonsense-mediated mRNA decay led to a substantial decline of IGF1R dosage and IGF-1-dependent receptor autophosphorylation but not impaired downstream signalling. We present the first detailed report of an intragenic IGF1R deletion identified in a patient who, apart from short stature, deviates from all established markers that qualify a growth-retarded child for IGF1R analysis. Although such children will usually escape routine clinical mutation screenings, they can contribute to the understanding of factors and mechanisms that cooperate with the IGF1R. © 2013 S. Karger AG, Basel.

Evidence for a link between TNFRSF11A and risk of breast cancer.

PubMed

Bonifaci, Núria; Palafox, Marta; Pellegrini, Pasquale; Osorio, Ana; Benítez, Javier; Peterlongo, Paolo; Manoukian, Siranoush; Peissel, Bernard; Zaffaroni, Daniela; Roversi, Gaia; Barile, Monica; Viel, Alessandra; Mariette, Frederique; Bernard, Loris; Radice, Paolo; Kaufman, Bella; Laitman, Yael; Milgrom, Roni; Friedman, Eitan; Sáez, María E; Climent, Fina; Soler, María Teresa; Diez, Orland; Balmaña, Judith; Lasa, Adriana; Ramón y Cajal, Teresa; Miramar, María-Dolores; de la Hoya, Miguel; Pérez-Segura, Pedro; Caldés, Trinidad; Moreno, Víctor; Urruticoechea, Ander; Brunet, Joan; Lázaro, Conxi; Blanco, Ignacio; Pujana, Miguel Angel; González-Suárez, Eva

2011-10-01

Intracellular signaling mediated by the receptor activator of nuclear factor-κB [Rank, encoded by the tumor necrosis factor receptor superfamily, member 11a (Tnfrsf11a) gene] is fundamental for mammary gland development in mice, regulating the expansion of stem and progenitor cell compartments. Conversely, Rank overexpression in mice promotes abnormal proliferation and impairs differentiation, leading to an increased incidence of tumorigenesis. Here, we show that a common genetic variant near the 5'-end of TNFRSF11A, rs7226991, is associated with breast cancer risk in the general population and among carriers of mutations in the breast cancer 2, early onset (BRCA2) gene. Akin to the results of the Cancer and Genetics Markers of Susceptibility initiative, combined analysis of rs7226991 in two Spanish case-control studies (1,365 controls and 1,323 cases in total) revealed a significant association with risk: odds ratio (OR) = 0.88, 95% confidence interval (CI) 0.78-0.98, P (trend) = 0.025. Subsequent examination of BRCA1 (n = 1,017) and BRCA2 (n = 885) mutation carriers revealed a consistent association in the latter group: weighted hazard ratio ((w)HR) = 0.70; 95% CI 0.55-0.88; and P (trend) = 0.003; compared to BRCA1 mutation carriers, (w)HR = 0.91; 95% CI 0.76-1.10; and P (trend) = 0.33. The results of this study need to be replicated in other populations and with larger numbers of BRCA1/2 mutation carriers.

Dramatic intracranial response to osimertinib in a poor performance status patient with lung adenocarcinoma harboring the epidermal growth factor receptor T790M mutation: A case report

PubMed Central

Uemura, Takehiro; Oguri, Tetsuya; Okayama, Minami; Furuta, Hiromi; Kanemitsu, Yoshihiro; Takakuwa, Osamu; Ohkubo, Hirotsugu; Takemura, Masaya; Maeno, Ken; Ito, Yutaka; Niimi, Akio

2017-01-01

We herein report a case of dramatic intracranial response to osimertinib in a poor performance status patient with lung adenocarcinoma harboring the epidermal growth factor receptor (EGFR) T790M mutation encoded in exon 20. The patient was a 59-year-old woman with EGFR exon 19 deletion-positive lung adenocarcinoma, who relapsed with multiple brain metastases. Computed tomography-guided biopsy of the left pleural tumor revealed adenocarcinoma harboring an EGFR exon 19 deletion and an EGFR T790M mutation encoded in exon 20. The patient was treated with osimertinib, a third-generation EGFR tyrosine kinase inhibitor. Two days after treatment initiation, the patient displayed profound disturbance of consciousness, possibly due to carcinomatous meningitis, and treatment had to be discontinued due to difficulty in taking osimertinib. However, the patient gradually started to recover consciousness and, after 3 days, she was again able to take osimertinib. One month after the initiation of osimertinib treatment, magnetic resonance imaging revealed an apparent reduction in brain metastases. The patient is currently under continued treatment with osimertinib. At the last follow-up (February, 2017) she exhibited partial response to the treatment. PMID:28413660

Epidermal Growth Factor Receptor (EGFR) Kinase Inhibitors and Non-Small Cell Lung Cancer (NSCLC) - Advances in Molecular Diagnostic Techniques to Facilitate Targeted Therapy.

PubMed

Ghafoor, Qamar; Baijal, Shobhit; Taniere, Phillipe; O'Sullivan, Brendan; Evans, Matthew; Middleton, Gary

2017-12-21

A subset of patients with non-small cell lung cancer (NSCLC) respond well to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR TKIs), due to the presence of sensitising mutations in the gene encoding EGFR. Mutations associated with resistance to first generation EGFR TKIs have also been identified, which lead to therapeutic failure and the requirement for new drugs. Three generations of EGFR TKIs have been developed and either have been, or are being, evaluated as first and/or second line therapeutic agents. In this review, we consider the advances in molecular diagnostic techniques that are used, or are in development, to facilitate the targeted EGFR TKI therapy of patients with NSCLC. A literature search was conducted in May 2017 using PubMed, and spanning the period September 2005 (EU approval date of erlotinib) to May 2017. Search terms used were: EGFR TKI, NSCLC, clinical trial, erlotinib, gefitinib, afatinib, EGFR mutations, Exon 19 deletion, and Leu858Arg. The use of molecular data, in conjunction with other clinical and diagnostic information, will assist physicians to make the best therapeutic choice for each patient with advanced NSCLC. Personalized medicine and a rapidly developing therapy landscape will enable these patients to achieve optimal responses to EGFR TKIs.

Detection of epidermal growth factor receptor mutation in lung cancer by droplet digital polymerase chain reaction

PubMed Central

Xu, Qing; Zhu, Yazhen; Bai, Yali; Wei, Xiumin; Zheng, Xirun; Mao, Mao; Zheng, Guangjuan

2015-01-01

Background Two types of epidermal growth factor receptor (EGFR) mutations in exon 19 and exon 21 (ex19del and L858R) are prevalent in lung cancer patients and sensitive to targeted EGFR inhibition. A resistance mutation in exon 20 (T790M) has been found to accompany drug treatment when patients relapse. These three mutations are valuable companion diagnostic biomarkers for guiding personalized treatment. Quantitative polymerase chain reaction (qPCR)-based methods have been widely used in the clinic by physicians to guide treatment decisions. The aim of this study was to evaluate the technical and clinical sensitivity and specificity of the droplet digital polymerase chain reaction (ddPCR) method in detecting the three EGFR mutations in patients with lung cancer. Methods Genomic DNA from H1975 and PC-9 cells, as well as 92 normal human blood specimens, was used to determine the technical sensitivity and specificity of the ddPCR assays. Genomic DNA of formalin-fixed, paraffin-embedded specimens from 78 Chinese patients with lung adenocarcinoma were assayed using both qPCR and ddPCR. Results The three ddPCR assays had a limit of detection of 0.02% and a wide dynamic range from 1 to 20,000 copies measurement. The L858R and ex19del assays had a 0% background level in the technical and clinical settings. The T790M assay appeared to have a 0.03% technical background. The ddPCR assays were robust for correct determination of EGFR mutation status in patients, and the dynamic range appeared to be better than qPCR methods. The ddPCR assay for T790M could detect patient samples that the qPCR method failed to detect. About 49% of this patient cohort had EGFR mutations (L858R, 15.4%; ex19del, 29.5%; T790M, 6.4%). Two patients with the ex19del mutation also had a naïve T790M mutation. Conclusion These data suggest that the ddPCR method could be useful in the personalized treatment of patients with lung cancer. PMID:26124670

A Japanese family with nonautoimmune hyperthyroidism caused by a novel heterozygous thyrotropin receptor gene mutation.

PubMed

Nakamura, Akie; Morikawa, Shuntaro; Aoyagi, Hayato; Ishizu, Katsura; Tajima, Toshihiro

2014-06-01

Hyperthyroidism caused by activating mutations of the thyrotropin receptor gene (TSHR) is rare in the pediatric population. We found a Japanese family with hyperthyroidism without autoantibody. DNA sequence analysis of TSHR was undertaken in this family. The functional consequences for the Gs-adenylyl cyclase and Gq/11-phospholipase C signaling pathways and cell surface expression of receptors were determined in vitro using transiently transfected human embryonic kidney 293 cells. We identified a heterozygous mutation (M453R) in exon 10 of TSHR. In this family, this mutation was found in all individuals who exhibited hyperthyroidism. The results showed that this mutation resulted in constitutive activation of the Gs-adenylyl cyclase system. However, this mutation also caused a reduction in the activation capacity of the Gq/11-phospholipase C pathway, compared with the wild type. We demonstrate that the M453R mutation is the cause of nonautoimmune hyperthyroidism.

Nonsquamous, Non-Small-Cell Lung Cancer Patients Who Carry a Double Mutation of EGFR, EML4-ALK or KRAS: Frequency, Clinical-Pathological Characteristics, and Response to Therapy.

PubMed

Ulivi, Paola; Chiadini, Elisa; Dazzi, Claudio; Dubini, Alessandra; Costantini, Matteo; Medri, Laura; Puccetti, Maurizio; Capelli, Laura; Calistri, Daniele; Verlicchi, Alberto; Gamboni, Alessandro; Papi, Maximilian; Mariotti, Marita; De Luigi, Nicoletta; Scarpi, Emanuela; Bravaccini, Sara; Turolla, Gian Michele; Amadori, Dino; Crinò, Lucio; Delmonte, Angelo

2016-09-01

Epidermal growth factor receptor (EGFR) and v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) mutations, and echinoderm microtubule-associated protein-like 4 (EML4) anaplastic lymphoma kinase (ALK) translocation are generally considered to be mutually exclusive. However, concomitant mutations are found in a small number of patients and the effect of these on response to targeted therapy is still unknown. We considered 380 non-small-cell lung cancer (NSCLC) patients who underwent nonsequential testing for EGFR and EML4-ALK translocation. KRAS mutation analysis was also performed on 282 patients. We found 1.6%, 1.1%, and 2.5% of patients who showed a double mutation comprising EGFR and EML4-ALK, EGFR and KRAS, and EML4-ALK and KRAS, respectively. Twenty-eight patients with EGFR mutation underwent first-line therapy with a tyrosine kinase receptor; a clinical benefit was observed in 81.8% of patients with EGFR mutations only and in 67% of those who also showed an EML4-ALK translocation. Twelve patients with an EML4-ALK translocation received crizotinib and 7 of these had disease progression within 3 months (2 had a concomitant KRAS mutation and 1 had a concomitant EGFR mutation). Two patients showed stable disease, 1 of whom also had a KRAS mutation. Two patients obtained a partial response and 1 had a complete response; all harbored an EML4-ALK translocation only. The median overall survival of patients who carried an EML4-ALK translocation alone or concomitant with a KRAS mutation was 57.1 (range, 10.7-not reached) and 10.7 (range, 4.6-not reached) months, respectively. Concomitant EGFR, EML4-ALK, or KRAS mutations can occur in NSCLC. Concomitant KRAS mutation and EML4-ALK translocation represents the most common double alteration and confers a poor prognosis. Copyright © 2015 Elsevier Inc. All rights reserved.

Clinical and Molecular Genetic Spectrum of Congenital Deficiency of the Leptin Receptor

PubMed Central

Farooqi, I. Sadaf; Wangensteen, Teresia; Collins, Stephan; Kimber, Wendy; Matarese, Giuseppe; Keogh, Julia M.; Lank, Emma; Bottomley, Bill; Lopez-Fernandez, Judith; Ferraz-Amaro, Ivan; Dattani, Mehul T.; Ercan, Oya; Myhre, Anne Grethe; Retterstol, Lars; Stanhope, Richard; Edge, Julie A.; McKenzie, Sheila; Lessan, Nader; Ghodsi, Maryam; De Rosa, Veronica; Perna, Francesco; Fontana, Silvia; Barroso, Inês; Undlien, Dag E.; O'Rahilly, Stephen

2009-01-01

BACKGROUND A single family has been described in which obesity results from a mutation in the leptin-receptor gene (LEPR), but the prevalence of such mutations in severe, early-onset obesity has not been systematically examined. METHODS We sequenced LEPR in 300 subjects with hyperphagia and severe early-onset obesity, including 90 probands from consanguineous families, and investigated the extent to which mutations cosegregated with obesity and affected receptor function. We evaluated metabolic, endocrine, and immune function in probands and affected relatives. RESULTS Of the 300 subjects, 8 (3%) had nonsense or missense LEPR mutations — 7 were homozygotes, and 1 was a compound heterozygote. All missense mutations resulted in impaired receptor signaling. Affected subjects were characterized by hyperphagia, severe obesity, alterations in immune function, and delayed puberty due to hypogonadotropic hypogonadism. Serum leptin levels were within the range predicted by the elevated fat mass in these subjects. Their clinical features were less severe than those of subjects with congenital leptin deficiency. CONCLUSIONS The prevalence of pathogenic LEPR mutations in a cohort of subjects with severe, early-onset obesity was 3%. Circulating levels of leptin were not disproportionately elevated, suggesting that serum leptin cannot be used as a marker for leptin-receptor deficiency. Congenital leptin-receptor deficiency should be considered in the differential diagnosis in any child with hyperphagia and severe obesity in the absence of developmental delay or dysmorphism. PMID:17229951

Clinical and molecular genetic spectrum of congenital deficiency of the leptin receptor.

PubMed

Farooqi, I Sadaf; Wangensteen, Teresia; Collins, Stephan; Kimber, Wendy; Matarese, Giuseppe; Keogh, Julia M; Lank, Emma; Bottomley, Bill; Lopez-Fernandez, Judith; Ferraz-Amaro, Ivan; Dattani, Mehul T; Ercan, Oya; Myhre, Anne Grethe; Retterstol, Lars; Stanhope, Richard; Edge, Julie A; McKenzie, Sheila; Lessan, Nader; Ghodsi, Maryam; De Rosa, Veronica; Perna, Francesco; Fontana, Silvia; Barroso, Inês; Undlien, Dag E; O'Rahilly, Stephen

2007-01-18

A single family has been described in which obesity results from a mutation in the leptin-receptor gene (LEPR), but the prevalence of such mutations in severe, early-onset obesity has not been systematically examined. We sequenced LEPR in 300 subjects with hyperphagia and severe early-onset obesity, including 90 probands from consanguineous families, and investigated the extent to which mutations cosegregated with obesity and affected receptor function. We evaluated metabolic, endocrine, and immune function in probands and affected relatives. Of the 300 subjects, 8 (3%) had nonsense or missense LEPR mutations--7 were homozygotes, and 1 was a compound heterozygote. All missense mutations resulted in impaired receptor signaling. Affected subjects were characterized by hyperphagia, severe obesity, alterations in immune function, and delayed puberty due to hypogonadotropic hypogonadism. Serum leptin levels were within the range predicted by the elevated fat mass in these subjects. Their clinical features were less severe than those of subjects with congenital leptin deficiency. The prevalence of pathogenic LEPR mutations in a cohort of subjects with severe, early-onset obesity was 3%. Circulating levels of leptin were not disproportionately elevated, suggesting that serum leptin cannot be used as a marker for leptin-receptor deficiency. Congenital leptin-receptor deficiency should be considered in the differential diagnosis in any child with hyperphagia and severe obesity in the absence of developmental delay or dysmorphism. Copyright 2007 Massachusetts Medical Society.

The intellectual capacity of patients with Laron syndrome (LS) differs with various molecular defects of the growth hormone receptor gene. Correlation with CNS abnormalities.

PubMed

Shevah, O; Kornreich, L; Galatzer, A; Laron, Z

2005-12-01

The correlation between the molecular defects of the GH receptor (R), psychosocial development and brain abnormalities were evaluated in 10 patients with Laron syndrome (LS), in whom all data were available. The findings revealed that the intelligence quotient (IQ) and abnormalities in the brain of the patients with LS differ with various molecular defects of the GH-receptor. The most severe mental deficits and brain pathology occurred in patients with 3, 5, 6 exon deletion. Patients with point mutations in exons 2, 4 and 7 presented various degrees of medium to mild CNS abnormalities that correlated with the IQ. Notably, the patient with the E180 splice mutation in exon 6 had a normal IQ, which fits the report on normal IQ in a large Ecuadorian cohort with the same mutation. This is the first report to support a correlation between IQ, brain abnormalities and localization of the molecular defects in the GH-R gene. As all patients with LS are IGF-I-deficient, it must be assumed that other as yet unknown factors related to the molecular defects in the GH-R are the major cause of the differences in intellect and brain abnormalities.

Veliparib and Carboplatin in Treating Patients With HER2-Negative Metastatic Breast Cancer

ClinicalTrials.gov

2018-04-20

BRCA1 Gene Mutation; BRCA2 Gene Mutation; Estrogen Receptor Negative; Estrogen Receptor Positive; HER2/Neu Negative; Progesterone Receptor Negative; Progesterone Receptor Positive; Recurrent Breast Carcinoma; Stage IIIB Breast Cancer AJCC v7; Stage IIIC Breast Cancer AJCC v7; Stage IV Breast Cancer AJCC v6 and v7; Triple-Negative Breast Carcinoma

An Arg for Gly substitution at position 31 in the insulin receptor, linked to insulin resistance, inhibits receptor processing and transport.

PubMed

van der Vorm, E R; van der Zon, G C; Möller, W; Krans, H M; Lindhout, D; Maassen, J A

1992-01-05

In a patient with Leprechaunism, we have characterized a new mutation in the insulin receptor substituting Arg for Gly at position 31. The proband, the mother, and the maternal grandfather were heterozygous for the mutation. Fibroblasts of the proband show a strongly reduced number of high affinity insulin receptors on the cell surface, whereas fibroblasts of the healthy mother and grandfather show moderately reduced insulin receptor numbers. In the other family members neither the binding defect nor the Arg31 mutation was found. The Arg31-mutant receptor was overexpressed in Chinese hamster ovary cells. In these cells the mutant alpha beta-proreceptor was not proteolytically cleaved and no transport to the cell surface took place. The proreceptor was unable to bind insulin and to undergo autophosphorylation. In addition, the proreceptor was not recognized by monoclonal antibodies directed against conformation-dependent epitopes. These findings suggest that the Gly31 to Arg31 mutant is involved in the insulin receptor dysfunction seen in the Leprechaun patient. The mutation seems to alter the conformation of the receptor in such way that the transport of the proreceptor to the Golgi compartment, where proteolytical processing occurs, is inhibited.

Signaling by Fibroblast Growth Factors (Fgf) and Fibroblast Growth Factor Receptor 2 (Fgfr2)–Activating Mutations Blocks Mineralization and Induces Apoptosis in Osteoblasts

PubMed Central

Mansukhani, Alka; Bellosta, Paola; Sahni, Malika; Basilico, Claudio

2000-01-01

Fibroblast growth factors (FGF) play a critical role in bone growth and development affecting both chondrogenesis and osteogenesis. During the process of intramembranous ossification, which leads to the formation of the flat bones of the skull, unregulated FGF signaling can produce premature suture closure or craniosynostosis and other craniofacial deformities. Indeed, many human craniosynostosis disorders have been linked to activating mutations in FGF receptors (FGFR) 1 and 2, but the precise effects of FGF on the proliferation, maturation and differentiation of the target osteoblastic cells are still unclear. In this report, we studied the effects of FGF treatment on primary murine calvarial osteoblast, and on OB1, a newly established osteoblastic cell line. We show that FGF signaling has a dual effect on osteoblast proliferation and differentiation. FGFs activate the endogenous FGFRs leading to the formation of a Grb2/FRS2/Shp2 complex and activation of MAP kinase. However, immature osteoblasts respond to FGF treatment with increased proliferation, whereas in differentiating cells FGF does not induce DNA synthesis but causes apoptosis. When either primary or OB1 osteoblasts are induced to differentiate, FGF signaling inhibits expression of alkaline phosphatase, and blocks mineralization. To study the effect of craniosynostosis-linked mutations in osteoblasts, we introduced FGFR2 carrying either the C342Y (Crouzon syndrome) or the S252W (Apert syndrome) mutation in OB1 cells. Both mutations inhibited differentiation, while dramatically inducing apoptosis. Furthermore, we could also show that overexpression of FGF2 in transgenic mice leads to increased apoptosis in their calvaria. These data provide the first biochemical analysis of FGF signaling in osteoblasts, and show that FGF can act as a cell death inducer with distinct effects in proliferating and differentiating osteoblasts. PMID:10851026

Three mutations switch H7N9 influenza to human-type receptor specificity.

PubMed

de Vries, Robert P; Peng, Wenjie; Grant, Oliver C; Thompson, Andrew J; Zhu, Xueyong; Bouwman, Kim M; de la Pena, Alba T Torrents; van Breemen, Marielle J; Ambepitiya Wickramasinghe, Iresha N; de Haan, Cornelis A M; Yu, Wenli; McBride, Ryan; Sanders, Rogier W; Woods, Robert J; Verheije, Monique H; Wilson, Ian A; Paulson, James C

2017-06-01

The avian H7N9 influenza outbreak in 2013 resulted from an unprecedented incidence of influenza transmission to humans from infected poultry. The majority of human H7N9 isolates contained a hemagglutinin (HA) mutation (Q226L) that has previously been associated with a switch in receptor specificity from avian-type (NeuAcα2-3Gal) to human-type (NeuAcα2-6Gal), as documented for the avian progenitors of the 1957 (H2N2) and 1968 (H3N2) human influenza pandemic viruses. While this raised concern that the H7N9 virus was adapting to humans, the mutation was not sufficient to switch the receptor specificity of H7N9, and has not resulted in sustained transmission in humans. To determine if the H7 HA was capable of acquiring human-type receptor specificity, we conducted mutation analyses. Remarkably, three amino acid mutations conferred a switch in specificity for human-type receptors that resembled the specificity of the 2009 human H1 pandemic virus, and promoted binding to human trachea epithelial cells.

Acquired EGFR T790M Mutation After Relapse Following EGFR-TKI Therapy: A Population-based Multi-institutional Study.

PubMed

Kaburagi, Takayuki; Kiyoshima, Moriyuki; Nawa, Takeshi; Ichimura, Hideo; Saito, Takefumi; Hayashihara, Kenji; Yamada, Hideyasu; Satoh, Hiroaki; Endo, Takeo; Inage, Yoshihisa; Saito, Kazuhito; Inagaki, Masaharu; Hizawa, Nobuyuki; Sato, Yukio; Ishikawa, Hiroichi; Sakai, Mitsuaki; Kamiyama, Koichi; Kikuchi, Norihiro; Nakamura, Hiroyuki; Furukawa, Kinya; Kodama, Takahide; Yamashita, Takaaki; Nomura, Akihiro; Yoshida, Susumu

2018-05-01

To describe the prevalence and determinants of acquired epidermal growth factor receptor (EGFR) T790M gene mutation in a clinical practice setting. We performed a retrospective chart review study between January 2013 and November 2017 across multiple institutes, covering a population of 3 million people. We reviewed the charts of 233 patients non-small cell lung cancer with EGFR mutations. Of them, 99 (42.5%) patients had acquired T790M mutations in EGFR. Patients ≥75 years old and patients with an exon 19 deletion had higher rates of acquired T790M mutation than did younger patients and those with an exon 21 L858R mutation. In 75 patients treated with afatinib, 34 (45.3%) patients had acquired T790M mutation. The sensitivity of T790M mutation detection was lower in plasma specimens than in biopsy specimens. This population-based study confirms previous studies and highlights potential determinants of acquired T790M mutation to be considered in clinical practice. Copyright© 2018, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Lack of hormone binding in COS-7 cells expressing a mutated growth hormone receptor found in Laron dwarfism.

PubMed Central

Edery, M; Rozakis-Adcock, M; Goujon, L; Finidori, J; Lévi-Meyrueis, C; Paly, J; Djiane, J; Postel-Vinay, M C; Kelly, P A

1993-01-01

A single point mutation in the growth hormone (GH) receptor gene generating a Phe-->Ser substitution in the extracellular binding domain of the receptor has been identified in one family with Laron type dwarfism. The mutation was introduced by site-directed mutagenesis into cDNAs encoding the full-length rabbit GH receptor and the extracellular domain or binding protein (BP) of the human and rabbit GH receptor, and also in cDNAs encoding the full length and the extracellular domain of the related rabbit prolactin (PRL) receptor. All constructs were transiently expressed in COS-7 cells. Both wild type and mutant full-length rabbit GH and PRL receptors, as well as GH and prolactin BPs (wild type and mutant), were detected by Western blot in cell membranes and concentrated culture media, respectively. Immunofluorescence studies showed that wild type and mutant full-length GH receptors had the same cell surface and intracellular distribution and were expressed with comparable intensities. In contrast, all mutant forms (full-length receptors or BPs), completely lost their modify the synthesis ligand. These results clearly demonstrate that this point mutation (patients with Laron syndrome) does not modify the synthesis or the intracellular pathway of receptor proteins, but rather abolishes ability of the receptor or BP to bind GH and is thus responsible for the extreme GH resistance in these patients. Images PMID:8450064

Detection of EGFR Gene Mutation by Mutation-oriented LAMP Method.

PubMed

Matsumoto, Naoyuki; Kumasaka, Akira; Ando, Tomohiro; Komiyama, Kazuo

2018-04-01

Epidermal growth factor receptor (EGFR) is a target of molecular therapeutics for non-small cell lung cancer. EGFR gene mutations at codons 746-753 promote constitutive EGFR activation and result in worst prognosis. However, these mutations augment the therapeutic effect of EGFR-tyrosine kinase inhibitor. Therefore, the detection of EGFR gene mutations is important for determining treatment planning. The aim of the study was to establish a method to detect EGFR gene mutations at codons 746-753. EGFR gene mutation at codons 746-753 in six cancer cell lines were investigated. A loop-mediated isothermal amplification (LAMP)-based procedure was developed, that employed peptide nucleic acid to suppress amplification of the wild-type allele. This mutation-oriented LAMP can amplify the DNA fragment of the EGFR gene with codons 746-753 mutations within 30 min. Moreover, boiled cells can work as template resources. Mutation oriented-LAMP assay for EGFR gene mutation is sensitive on extracted DNA. This procedure would be capable of detecting EGFR gene mutation in sputum, pleural effusion, broncho-alveolar lavage fluid or trans-bronchial lung biopsy by chair side. Copyright© 2018, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

A substitutional mutation in the DNA binding domain of the androgen receptor causes complete androgen insensitivity syndrome.

PubMed

Komori, S; Sakata, K; Kasumi, H; Tsuji, Y; Hamada, K; Koyama, K

1999-10-01

DNA analysis of the androgen receptor gene in a patient with complete androgen insensitivity syndrome identified a substitutional mutation (tyrosine converted to cysteine at position 571) in the DNA binding domain. In vitro transfection experiments with the patients' androgen receptor gene, indicated normal expression of the androgen receptor in transfected COS-7 cells compared to the wild type gene. There was also no evidence of impaired thermal stability of the 5 alpha-dihydrotestosterone-androgen receptor complex. However, the capacity of the androgen receptor to activate target gene transcription was found to be completely disrupted in a luciferase assay. These results confirmed that only one substitutional mutation in the DNA binding domain was related to the pathogenesis of the complete androgen insensitivity syndrome.

An exon 4 mutation identified in the majority of South African familial hypercholesterolaemics.

PubMed Central

Kotze, M J; Warnich, L; Langenhoven, E; du Plessis, L; Retief, A E

1990-01-01

The prevalence of familial hypercholesterolaemia (FH) is significantly higher in the Afrikaans speaking population (Afrikaners) of South Africa than reported in most other populations. A founder gene effect has been proposed to explain the high FH frequency, implying that the same low density lipoprotein (LDL) receptor gene defect is present in the majority of affected Afrikaners. By using DNA amplification and sequence determination, we have detected a point mutation in DNA from two Afrikaner FH homozygotes. A cytosine to guanine base substitution at nucleotide position 681 of the LDL receptor cDNA results in an amino acid change from aspartic acid to glutamic acid at residue 206 in the cysteine rich ligand binding domain of the LDL receptor. Since three previously mapped transport deficient alleles of the LDL receptor were also traced to cysteine rich repeats of the protein, these results suggest that the mutation is responsible for the receptor defective mutation predominantly found in Afrikaner FH homozygotes. The mutation gives rise to an additional DdeI restriction site in DNA of affected subjects and segregation of the mutation with the disease was confirmed in five large Afrikaner FH families. We predict that 65% of affected South African Afrikaners carry this particular base substitution. Amplification of genomic DNA, using the polymerase chain reaction method, and restriction enzyme analysis now permit accurate diagnosis of the mutation in subjects with FH. Images PMID:2352257

Mutations in DSTYK and dominant urinary tract malformations.

PubMed

Sanna-Cherchi, Simone; Sampogna, Rosemary V; Papeta, Natalia; Burgess, Katelyn E; Nees, Shannon N; Perry, Brittany J; Choi, Murim; Bodria, Monica; Liu, Yan; Weng, Patricia L; Lozanovski, Vladimir J; Verbitsky, Miguel; Lugani, Francesca; Sterken, Roel; Paragas, Neal; Caridi, Gianluca; Carrea, Alba; Dagnino, Monica; Materna-Kiryluk, Anna; Santamaria, Giuseppe; Murtas, Corrado; Ristoska-Bojkovska, Nadica; Izzi, Claudia; Kacak, Nilgun; Bianco, Beatrice; Giberti, Stefania; Gigante, Maddalena; Piaggio, Giorgio; Gesualdo, Loreto; Vukic, Durdica Kosuljandic; Vukojevic, Katarina; Saraga-Babic, Mirna; Saraga, Marijan; Gucev, Zoran; Allegri, Landino; Latos-Bielenska, Anna; Casu, Domenica; State, Matthew; Scolari, Francesco; Ravazzolo, Roberto; Kiryluk, Krzysztof; Al-Awqati, Qais; D'Agati, Vivette D; Drummond, Iain A; Tasic, Velibor; Lifton, Richard P; Ghiggeri, Gian Marco; Gharavi, Ali G

2013-08-15

Congenital abnormalities of the kidney and the urinary tract are the most common cause of pediatric kidney failure. These disorders are highly heterogeneous, and the etiologic factors are poorly understood. We performed genomewide linkage analysis and whole-exome sequencing in a family with an autosomal dominant form of congenital abnormalities of the kidney or urinary tract (seven affected family members). We also performed a sequence analysis in 311 unrelated patients, as well as histologic and functional studies. Linkage analysis identified five regions of the genome that were shared among all affected family members. Exome sequencing identified a single, rare, deleterious variant within these linkage intervals, a heterozygous splice-site mutation in the dual serine-threonine and tyrosine protein kinase gene (DSTYK). This variant, which resulted in aberrant splicing of messenger RNA, was present in all affected family members. Additional, independent DSTYK mutations, including nonsense and splice-site mutations, were detected in 7 of 311 unrelated patients. DSTYK is highly expressed in the maturing epithelia of all major organs, localizing to cell membranes. Knockdown in zebrafish resulted in developmental defects in multiple organs, which suggested loss of fibroblast growth factor (FGF) signaling. Consistent with this finding is the observation that DSTYK colocalizes with FGF receptors in the ureteric bud and metanephric mesenchyme. DSTYK knockdown in human embryonic kidney cells inhibited FGF-stimulated phosphorylation of extracellular-signal-regulated kinase (ERK), the principal signal downstream of receptor tyrosine kinases. We detected independent DSTYK mutations in 2.3% of patients with congenital abnormalities of the kidney or urinary tract, a finding that suggests that DSTYK is a major determinant of human urinary tract development, downstream of FGF signaling. (Funded by the National Institutes of Health and others.).

Mutations in DSTYK and Dominant Urinary Tract Malformations

PubMed Central

Sanna-Cherchi, Simone; Nees, Shannon N.; Perry, Brittany J.; Choi, Murim; Bodria, Monica; Liu, Yan; Weng, Patricia L.; Lozanovski, Vladimir J.; Verbitsky, Miguel; Lugani, Francesca; Sterken, Roel; Paragas, Neal; Caridi, Gianluca; Carrea, Alba; Dagnino, Monica; Materna-Kiryluk, Anna; Santamaria, Giuseppe; Murtas, Corrado; Ristoska-Bojkovska, Nadica; Izzi, Claudia; Kacak, Nilgun; Bianco, Beatrice; Giberti, Stefania; Gigante, Maddalena; Piaggio, Giorgio; Gesualdo, Loreto; Vukic, Durdica Kosuljandic; Vukojevic, Katarina; Saraga-Babic, Mirna; Saraga, Marijan; Gucev, Zoran; Allegri, Landino; Latos-Bielenska, Anna; Casu, Domenica; State, Matthew; Scolari, Francesco; Ravazzolo, Roberto; Kiryluk, Krzysztof; Al-Awqati, Qais; D'Agati, Vivette D.; Drummond, Iain A.; Tasic, Velibor; Lifton, Richard P.; Ghiggeri, Gian Marco; Gharavi, Ali G.

2013-01-01

BACKGROUND Congenital abnormalities of the kidney and the urinary tract are the most common cause of pediatric kidney failure. These disorders are highly heterogeneous, and the etiologic factors are poorly understood. METHODS We performed genomewide linkage analysis and whole-exome sequencing in a family with an autosomal dominant form of congenital abnormalities of the kidney or urinary tract (seven affected family members). We also performed a sequence analysis in 311 unrelated patients, as well as histologic and functional studies. RESULTS Linkage analysis identified five regions of the genome that were shared among all affected family members. Exome sequencing identified a single, rare, deleterious variant within these linkage intervals, a heterozygous splice-site mutation in the dual serine–threonine and tyrosine protein kinase gene (DSTYK). This variant, which resulted in aberrant splicing of messenger RNA, was present in all affected family members. Additional, independent DSTYK mutations, including nonsense and splice-site mutations, were detected in 7 of 311 unrelated patients. DSTYK is highly expressed in the maturing epithelia of all major organs, localizing to cell membranes. Knockdown in zebrafish resulted in developmental defects in multiple organs, which suggested loss of fibroblast growth factor (FGF) signaling. Consistent with this finding is the observation that DSTYK colocalizes with FGF receptors in the ureteric bud and metanephric mesenchyme. DSTYK knockdown in human embryonic kidney cells inhibited FGF-stimulated phosphorylation of extracellular-signal-regulated kinase (ERK), the principal signal downstream of receptor tyrosine kinases. CONCLUSIONS We detected independent DSTYK mutations in 2.3% of patients with congenital abnormalities of the kidney or urinary tract, a finding that suggests that DSTYK is a major determinant of human urinary tract development, downstream of FGF signaling. (Funded by the National Institutes of Health and others.) PMID:23862974

BRCA1 Mutations Associated With Increased Risk of Brain Metastases in Breast Cancer: A 1: 2 Matched-pair Analysis.

PubMed

Zavitsanos, Peter J; Wazer, David E; Hepel, Jaroslaw T; Wang, Yihong; Singh, Kamaljeet; Leonard, Kara L

2018-05-18

Brain metastases (BM) occur in ∼5% of breast cancer patients. BRCA1-associated cancers are often basal-like and basal-like cancers are known to have a predilection for central nervous system metastases. We performed a matched-pair analysis of breast cancer patients with and without BRCA mutations and compared the frequency of BM in both groups. From a database of 1935 patients treated for localized breast cancer at our institution from 2009 to 2014 we identified 20 patients with BRCA1 or BRCA2 mutations and manually matched 40 patients without BRCA mutations accounting for age, stage, estrogen receptor expression, and human epidermal growth factor receptor 2 (HER2) expression. Comparisons of freedom from brain metastasis, brain metastasis-free survival, and overall survival were made using the log rank test. Testing for a basal-type phenotype using the immunohistochemistry definition (ER/PR/HER2 and either CK 5/6 or EGFR) was performed for BRCA patients who developed BM and their matched controls. We analyzed 60 patients: 20 BRCA and 40 were matched controls. Median follow-up was 37 and 49 months, respectively. Three years freedom from brain metastasis was 84% for BRCA patients and 97% for BRCA controls (P=0.049). Three years brain metastasis-free survival was 84% and 97% for the BRCA+ and controls, respectively (P=0.176). Mean time to brain failure was 11 months from diagnosis for the BRCA patients. All 3 BRCA1 patients who developed BM were of a basal-type triple negative phenotype. Breast cancer patients with germline BRCA1 mutations appear to have a shorter interval to brain progression while accounting for confounding factors.

Consensus on management of metastatic colorectal cancer in Central America and the Caribbean: San José, Costa Rica, August 2016

PubMed Central

López, Roberto Ivan; Castro, Jenny Lissette; Cedeño, Heidy; Cisneros, Dagoberto; Corrales, Luis; González-Herrera, Ileana; Lima-Pérez, Mayté; Prestol, Rogelio; Salinas, Roberto; Soriano-García, Jorge Luis; T Zavala, Alejandra; Zetina, Luis Miguel; Zúñiga-Orlich, Carlos Eduardo

2018-01-01

Colorectal cancer (CRC) is the third most common cancer in men and the second most common in women worldwide. In Latin America and the Caribbean, it has a mortality of 56%. The median overall survival for patients with metastatic colorectal cancer (mCRC) is currently estimated as ~30 months, which has substantially improved through strategic changes in treatment and in the management of patients. As opposed to other metastatic cancers where first-line regimens are often determined, mCRC requires special attention because there is controversy in the possible combinations of the available drugs and the different periods of duration for each patient. Each combination must seek to be effective and to generate the minimum adverse effects as possible. Instead of giving the first-line regimen until the tumour progresses, treatment is often individualised. Furthermore, up to 60% of colorectal tumours are considered non-mutated or wild-type CRC. Not harbouring mutations in the RAS family of genes or mutations in the signalling pathways of the epidermal growth factor receptor causes a null response to anti-epidermal growth factor receptor antibody therapy, which implies even more complex considerations regarding its management. The primary objective of this consensus is to address the main scenarios of mCRC in order to warrant the most appropriate therapeutic intervention for these patients in the Central American and the Caribbean (CAC) region. This can lead to better clinical outcomes as well as quality of life for palliative patients. This document includes the formal expert consensus recommendations for scenarios of mutated and non-mutated mCRC, including synchronous or metachronous disease, management of mCRC with liver and lung metastasis, resectable, potentially resectable or non-resectable tumours and local in the CAC context. PMID:29636987

Racial Disparities in the Molecular Landscape of Cancer.

PubMed

Heath, Elisabeth I; Lynce, Filipa; Xiu, Joanne; Ellerbrock, Angela; Reddy, Sandeep K; Obeid, Elias; Liu, Stephen V; Bollig-Fischer, Aliccia; Separovic, Duska; Vanderwalde, Ari

2018-04-01

African Americans (AA) have the highest incidence and mortality of any racial/ethnic group in the US for most cancer types. Heterogeneity in the molecular biology of cancer, as a contributing factor to this disparity, is poorly understood. To address this gap in knowledge, we explored the molecular landscape of colorectal cancer (CRC), non-small cell lung cancer (NSCLC) and high-grade glioma (HGG) from 271 AA and 636 Caucasian (CC) cases. DNA from formalin-fixed paraffin-embedded tumors was sequenced using next-generation sequencing. Additionally, we evaluated protein expression using immunohistochemistry. The Exome Aggregation Consortium Database was evaluated for known ethnicity associations. Considering only pathogenic or presumed pathogenic mutations, as determined by the American College of Medical Genetics and Genomics guidelines, and using Bonferroni and Benjamini-Hochberg corrections for multiple comparisons, we found that CRC tumors from AA patients harbored significantly more mutations of phosphatidylinositol-4,5-bisphosphate 3-kinase, catalytic subunit alpha (PIK3CA) than those from CC patients. CRC tumors in AA patients also appeared to harbor more mutations of mitogen-activated protein kinase kinase 1 (MAP2K1/MEK1), MPL proto-oncogene (MPL), thrombo-poietin receptor, and neurofibromin 1 (NF1) than those from CC patients. In contrast, CRCs from AA patients were likely to carry fewer mutations of ataxia-telangiectasia mutated (ATM), as well as of proto-oncogene B-Raf (BRAF), including the V600E variant, than those from CC patients. Rates of immunohistochemical positivity for epidermal growth factor receptor (EGFR) and DNA topoisomerase 2-alpha (TOP2A) tended to be higher in CRCs from AA patients than in CC patients. In NSCLC adenocarcinoma, BRAF variants appeared to be more frequent in the AA than in the CC cohort, whereas in squamous cell lung carcinoma, programmed death-ligand 1 (PD-L1) expression tended to be lower in the AA than in CC group. Moreover, HGG tumors from AA patients showed a trend toward harboring more mutations of protein tyrosine phosphatase non-receptor 11 (PTPN11), than HGG tumors from the CC cohort. In contrast, mutations of phosphatase and tensin homolog (PTEN) and tumor protein 53 (TP53) appeared to be higher in HGG tumors in CC patients than in their AA counterparts. Our data revealed significant differences and trends in molecular signatures of the three cancer types in AA and CC cohorts. These findings imply that there may be differences in carcinogenesis between AA and CC patients and that race may be a factor that should be considered regarding cancer incidence and outcome. Copyright© 2018, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Synergistic effect of pacritinib with erlotinib on JAK2-mediated resistance in epidermal gowth factor receptor mutation-positive non-small cell lung Cancer.

PubMed

Ochi, Nobuaki; Isozaki, Hideko; Takeyama, Masami; Singer, Jack W; Yamane, Hiromichi; Honda, Yoshihiro; Kiura, Katsuyuki; Takigawa, Nagio

2016-06-10

The combination effect of pacritinib, a novel JAK2/FLT3 inhibitor, with erlotinib, the epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI), on non-small cell lung cancer cells with EGFR activating mutations was investigated. The combination showed synergistic effects on JAK2-mediated EGFR TKI-resistant PC-9/ER3 cells in some cases. The combination markedly suppressed pAKT and pERK although pSTAT3 expression was similar regardless of treatment with the pacritinib, pacritinib + erlotinib, or control in PC-9/ER3 cells. Receptor tyrosine kinase array profiling demonstrated that pacritinib suppressed MET in the PC-9/ER3 cells. The combined treatment of pacritinib and erlotinib in PC-9/ER3 xenografts showed more tumor shrinkage compared with each drug as monotherapy. Western blotting revealed that pMET in tumor samples was inhibited. These results suggest MET suppression by pacritinib may play a role in overcoming the EGFR-TKI resistance mediated by JAK2 in the PC-9/ER3 cells. In conclusion, pacritinib combined with EGFR-TKI might be a potent strategy against JAK2-mediated EGFR-TKI resistance. Copyright © 2016 Elsevier Inc. All rights reserved.

Heterodimerization of wild-type and mutant fibroblast growth factor receptors in cell-derived vesicles

NASA Astrophysics Data System (ADS)

Hristova, Kalina; Del Piccolo, Nuala; Sarabipour, Sarvenaz

The activity of receptor tyrosine kinases (RTKs) is controlled through their lateral dimerization in the plasma membrane. RTKs are believed to form both homodimers and heterodimers, and the different dimers are believed to play unique roles in cell signaling. However, RTK heterodimers remain poorly characterized, as compared to homodimers, due to limitations in current experimental methods. Here, we develop a Förster Resonance Energy Transfer (FRET)-based methodology to assess the thermodynamics of hetero-interactions in the plasma membrane. To demonstrate the utility of the methodology, we use it to study the hetero-interactions between three Fibroblast Growth Factor Receptors - FGFR1, FGFR2, and FGFR3 - in the absence of ligand. Our results show that all possible FGFR heterodimers form, suggesting that the biological roles of FGFR heterodimers may be as significant as the homodimer roles. We further investigate the effect of two pathogenic point mutations in FGFR3 (A391E and G380R) on heterodimerization. We show that each of these mutations stabilize most of the heterodimers, with the largest effects observed for FGFR3 wild-type/mutant heterodimers. We thus demonstrate that the methodology presented here can yield new knowledge about RTK interactions and can further our understanding of signal transduction across the plasma membrane..

Vitellogenin Receptor Mutation Leads to the Oogenesis Mutant Phenotype “scanty vitellin” of the Silkworm, Bombyx mori*

PubMed Central

Lin, Ying; Meng, Yan; Wang, Yan-Xia; Luo, Juan; Katsuma, Susumu; Yang, Cong-Wen; Banno, Yutaka; Kusakabe, Takahiro; Shimada, Toru; Xia, Qing-You

2013-01-01

In insects, the vitellogenin receptor (VgR) mediates the uptake of vitellogenin (Vg) from the hemolymph by developing oocytes. The oogenesis mutant scanty vitellin (vit) of Bombyx mori (Bm) lacks vitellin and 30-kDa proteins, but B. mori egg-specific protein and BmVg are normal. The vit eggs are white and smaller compared with the pale yellow eggs of the wild type and are embryonic lethal. This study found that a mutation in the B. mori VgR gene (BmVgR) is responsible for the vit phenotype. We cloned the cDNA sequences encoding WT and vit BmVgR. The functional domains of BmVgR are similar to those of other low-density lipoprotein receptors. When compared with the wild type, a 235-bp genomic sequence in vit BmVgR is substituted for a 7-bp sequence. This mutation has resulted in a 50-amino acid deletion in the third Class B region of the first epidermal growth factor (EGF1) domain. BmVgR is expressed specifically in oocytes, and the transcriptional level is changed dramatically and consistently with maturation of oocytes during the previtellogenic periods. Linkage analysis confirmed that BmVgR is mutated in the vit mutant. The coimmunoprecipitation assay confirmed that mutated BmVgR is able to bind BmVg but that BmVg cannot be dissociated under acidic conditions. The WT phenotype determined by RNA interference was similar to that of the vit phenotype for nutritional deficiency, such as BmVg and 30-kDa proteins. These results showed that BmVgR has an important role in transporting proteins for egg formation and embryonic development in B. mori. PMID:23515308

Effects of asparagine mutagenesis of conserved aspartic acids in helix two (D2.50) and three (D3.32) of M1 – M4 muscarinic receptors on the irreversible binding of nitrogen mustard analogs of acetylcholine and McN-A-343

PubMed Central

Suga, Hinako; Ehlert, Frederick J.

2013-01-01

We investigated how asparagine mutagenesis of conserved aspartic acids in helix two (D2.50) and three (D3.32) of M1 – M4 muscarinic receptors alters the irreversible binding of acetylcholine mustard and BR384 (4-[(2-bromoethyl)methyl-amino]-2-butynyl N-(3-chlorophenyl)carbamate), a nitrogen mustard derivative of McN-A-343 ([4-[[N-(3-chlorophenyl)carbamoyl]oxy]-2-butynyl] trimethylammonium chloride). The D2.50N mutation moderately increased the affinity of the aziridinium ions of acetylcholine mustard and BR384 for M2 – M4 receptors and had little effect on the rate constant for receptor alkylation. The D3.32N mutation greatly reduced the rate constant for receptor alkylation by acetylcholine mustard, but not by BR384, although the affinity of BR384 was reduced. The combination of both mutations (D2.50N/D3.32N) substantially reduced the rate constant for receptor alkylation by BR384 relative to wild type and mutant D2.50N and D3.32N receptors. The change in binding affinity caused by the mutations suggests that the D2.50N mutation alters the interaction of acetylcholine mustard with D3.32 of M1 and M3 receptors, but not that of the M4 receptor. BR384 exhibited the converse relationship. The simplest explanation is that acetylcholine mustard and BR384 alkylate at least two residues on M1 – M4 receptors and that the D2.50N mutation alters the rate of alkylation of D3.32 relative to another residue, perhaps D2.50 itself. PMID:23826889

Development of the Third Generation EGFR Tyrosine Kinase Inhibitors for Anticancer Therapy.

PubMed

Cheng, Weiyan; Zhou, Jianhua; Tian, Xin; Zhang, Xiaojian

2016-01-01

Epidermal growth factor receptor (EGFR) is one of the most important targets in anticancer therapy. Till date, a large number of first and second generation EGFR tyrosine kinase inhibitors (TKIs) have been marketed or advanced into clinical studies. However, the occurrence of TKI-resistant mutations has led to the loss of efficacy of these inhibitors. In the purpose of overcoming resistant mutations and reducing side effects, lots of third generation EGFR inhibitors are explored with promising potencies against EGFR mutations while sparing wild-type EGFR. This review outlines the current landscape of the development of third generation EGFR inhibitors, mainly focusing on the biological properties, clinical status and structure-activity relationships.

Functional studies of RYR1 mutations in the skeletal muscle ryanodine receptor using human RYR1 complementary DNA.

PubMed

Sato, Keisaku; Pollock, Neil; Stowell, Kathryn M

2010-06-01

Malignant hyperthermia is associated with mutations within the gene encoding the skeletal muscle ryanodine receptor, the calcium channel that releases Ca from sarcoplasmic reticulum stores triggering muscle contraction, and other metabolic activities. More than 200 variants have been identified in the ryanodine receptor, but only some of these have been shown to functionally affect the calcium channel. To implement genetic testing for malignant hyperthermia, variants must be shown to alter the function of the channel. A number of different ex vivo methods can be used to demonstrate functionality, as long as cells from human patients can be obtained and cultured from at least two unrelated families. Because malignant hyperthermia is an uncommon disorder and many variants seem to be private, including the newly identified H4833Y mutation, these approaches are limited. The authors cloned the human skeletal muscle ryanodine receptor complementary DNA and expressed both normal and mutated forms in HEK-293 cells and carried out functional analysis using ryanodine binding assays in the presence of a specific agonist, 4-chloro-m-cresol, and the antagonist Mg. Transiently expressed human ryanodine receptor proteins colocalized with an endoplasmic reticulum marker in HEK-293 cells. Ryanodine binding assays confirmed that mutations causing malignant hyperthermia resulted in a hypersensitive channel, while those causing central core disease resulted in a hyposensitive channel. The functional assays validate recombinant human skeletal muscle ryanodine receptor for analysis of variants and add an additional mutation (H4833Y) to the repertoire of mutations that can be used for the genetic diagnosis of malignant hyperthermia.

Ligand regulation of a constitutively dimeric EGF receptor

NASA Astrophysics Data System (ADS)

Freed, Daniel M.; Alvarado, Diego; Lemmon, Mark A.

2015-06-01

Ligand-induced receptor dimerization has traditionally been viewed as the key event in transmembrane signalling by epidermal growth factor receptors (EGFRs). Here we show that the Caenorhabditis elegans EGFR orthologue LET-23 is constitutively dimeric, yet responds to its ligand LIN-3 without changing oligomerization state. SAXS and mutational analyses further reveal that the preformed dimer of the LET-23 extracellular region is mediated by its domain II dimerization arm and resembles other EGFR extracellular dimers seen in structural studies. Binding of LIN-3 induces only minor structural rearrangements in the LET-23 dimer to promote signalling. Our results therefore argue that EGFR can be regulated by allosteric changes within an existing receptor dimer--resembling signalling by insulin receptor family members, which share similar extracellular domain compositions but form covalent dimers.

EGFR G796D mutation mediates resistance to osimertinib.

PubMed

Zheng, Di; Hu, Min; Bai, Yu; Zhu, Xuehua; Lu, Xuesong; Wu, Chunyan; Wang, Jiying; Liu, Li; Wang, Zheng; Ni, Jian; Yang, Zhenfan; Xu, Jianfang

2017-07-25

Osimertinib is an effective third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) approved in multiple countries and regions for patients with EGFR T790M mutation-positive non-small cell lung cancer (NSCLC). Despite impressive initial tumor responses, development of drug resistance ultimately limits the benefit of this compound. Mechanisms of resistance to osimertinib are just beginning to emerge, such as EGFR C797S and L718Q mutations, BRAF V600E and PIK3CA E545K mutations, as well as ERBB2 and MET amplification. However, a comprehensive view is still missing. In this study, we presented the first case of Chinese NSCLC patient who developed resistance to osimertinib, and discovered de novo EGFR G796D mutation as a potential mechanism. Our findings provided insights into mechanisms of resistance to osimertinib and highlighted tumor heterogeneity and clonal evolution during the development of drug resistance.

EGFR G796D mutation mediates resistance to osimertinib

PubMed Central

Bai, Yu; Zhu, Xuehua; Lu, Xuesong; Wu, Chunyan; Wang, Jiying; Liu, Li; Wang, Zheng; Ni, Jian; Yang, Zhenfan; Xu, Jianfang

2017-01-01

Osimertinib is an effective third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) approved in multiple countries and regions for patients with EGFR T790M mutation-positive non-small cell lung cancer (NSCLC). Despite impressive initial tumor responses, development of drug resistance ultimately limits the benefit of this compound. Mechanisms of resistance to osimertinib are just beginning to emerge, such as EGFR C797S and L718Q mutations, BRAF V600E and PIK3CA E545K mutations, as well as ERBB2 and MET amplification. However, a comprehensive view is still missing. In this study, we presented the first case of Chinese NSCLC patient who developed resistance to osimertinib, and discovered de novo EGFR G796D mutation as a potential mechanism. Our findings provided insights into mechanisms of resistance to osimertinib and highlighted tumor heterogeneity and clonal evolution during the development of drug resistance. PMID:28572531

Computational design of thermostabilizing point mutations for G protein-coupled receptors

PubMed Central

Popov, Petr; Peng, Yao; Shen, Ling; Stevens, Raymond C; Cherezov, Vadim; Liu, Zhi-Jie

2018-01-01

Engineering of GPCR constructs with improved thermostability is a key for successful structural and biochemical studies of this transmembrane protein family, targeted by 40% of all therapeutic drugs. Here we introduce a comprehensive computational approach to effective prediction of stabilizing mutations in GPCRs, named CompoMug, which employs sequence-based analysis, structural information, and a derived machine learning predictor. Tested experimentally on the serotonin 5-HT2C receptor target, CompoMug predictions resulted in 10 new stabilizing mutations, with an apparent thermostability gain ~8.8°C for the best single mutation and ~13°C for a triple mutant. Binding of antagonists confers further stabilization for the triple mutant receptor, with total gains of ~21°C as compared to wild type apo 5-HT2C. The predicted mutations enabled crystallization and structure determination for the 5-HT2C receptor complexes in inactive and active-like states. While CompoMug already shows high 25% hit rate and utility in GPCR structural studies, further improvements are expected with accumulation of structural and mutation data. PMID:29927385

Functional mutation analysis of EGFR family genes and corresponding lymph node metastases in head and neck squamous cell carcinoma.

PubMed

Hama, Takanori; Yuza, Yuki; Suda, Toshihito; Saito, Yoshimichi; Norizoe, Chihiro; Kato, Takakuni; Moriyama, Hiroshi; Urashima, Mitsuyoshi

2012-01-01

Tumors with certain mutations in the epidermal growth factor receptor (EGFR) family genes dramatically respond to EGFR inhibitors. Therefore, these mutations are important factors that influence disease progression and patient survival. We previously studied the mutation status of EGFR in patients with head and neck squamous cell carcinoma (HNSCC). However, the mutation status of lymph node metastases and the frequency of mutations in EGFR family genes have not been extensively studied. In this study, we sequenced the catalytic domains of the three other members of the EGFR family, HER2, HER3, and HER4 in 92 clinical samples of HNSCC. We identified a HER2 mutation (K716E) in one sample but no mutations were found in HER3 or HER4. Next to investigate the relationship between EGFR mutations and tumor metastasis, we compared the DNA sequences of the EGFR gene between the primary tumor and the lymph node metastasis in 31 clinical samples. Only one of the patients with an EGFR mutation in the primary HNSCC carried the same mutation (L858R) in the lymph node metastasis. Finally, we explored the tumorigenic potential of the EGFR mutations that we had previously identified and their sensitivity to two different EGFR tyrosine kinase inhibitors (CL-387785, OSI-420). Ba/F3 cells transformed with mutant EGFR genes were sensitive to treatment with lower concentrations of CL-387785 than of OSI-420. These results contribute to our understanding of the genetic basis of drug sensitivity and will help design drugs that specifically target different subtypes of HNSCC.

Autosomal recessive mutations in nuclear transport factor KPNA7 are associated with infantile spasms and cerebellar malformation.

PubMed

Paciorkowski, Alex R; Weisenberg, Judy; Kelley, Joshua B; Spencer, Adam; Tuttle, Emily; Ghoneim, Dalia; Thio, Liu Lin; Christian, Susan L; Dobyns, William B; Paschal, Bryce M

2014-05-01

Nuclear import receptors of the KPNA family recognize the nuclear localization signal in proteins and together with importin-β mediate translocation into the nucleus. Accordingly, KPNA family members have a highly conserved architecture with domains that contact the nuclear localization signal and bind to importin-β. Here, we describe autosomal recessive mutations in KPNA7 found by whole exome sequencing in a sibling pair with severe developmental disability, infantile spasms, subsequent intractable epilepsy consistent with Lennox-Gastaut syndrome, partial agenesis of the corpus callosum, and cerebellar vermis hypoplasia. The mutations mapped to exon 7 in KPNA7 result in two amino-acid substitutions, Pro339Ala and Glu344Gln. On the basis of the crystal structure of the paralog KPNA2 bound to a bipartite nuclear localization signal from the retinoblastoma protein, the amino-acid substitutions in the affected subjects were predicted to occur within the seventh armadillo repeat that forms one of the two nuclear localization signal-binding sites in KPNA family members. Glu344 is conserved in all seven KPNA proteins, and we found that the Glu354Gln mutation in KPNA2 is sufficient to reduce binding to the retinoblastoma nuclear localization signal to approximately one-half that of wild-type protein. Our data show that compound heterozygous mutations in KPNA7 are associated with a human neurodevelopmental disease, and provide the first example of a human disease associated with mutation of a nuclear transport receptor.

Autosomal recessive mutations in nuclear transport factor KPNA7 are associated with infantile spasms and cerebellar malformation

PubMed Central

Paciorkowski, Alex R; Weisenberg, Judy; Kelley, Joshua B; Spencer, Adam; Tuttle, Emily; Ghoneim, Dalia; Thio, Liu Lin; Christian, Susan L; Dobyns, William B; Paschal, Bryce M

2014-01-01

Nuclear import receptors of the KPNA family recognize the nuclear localization signal in proteins and together with importin-β mediate translocation into the nucleus. Accordingly, KPNA family members have a highly conserved architecture with domains that contact the nuclear localization signal and bind to importin-β. Here, we describe autosomal recessive mutations in KPNA7 found by whole exome sequencing in a sibling pair with severe developmental disability, infantile spasms, subsequent intractable epilepsy consistent with Lennox–Gastaut syndrome, partial agenesis of the corpus callosum, and cerebellar vermis hypoplasia. The mutations mapped to exon 7 in KPNA7 result in two amino-acid substitutions, Pro339Ala and Glu344Gln. On the basis of the crystal structure of the paralog KPNA2 bound to a bipartite nuclear localization signal from the retinoblastoma protein, the amino-acid substitutions in the affected subjects were predicted to occur within the seventh armadillo repeat that forms one of the two nuclear localization signal-binding sites in KPNA family members. Glu344 is conserved in all seven KPNA proteins, and we found that the Glu354Gln mutation in KPNA2 is sufficient to reduce binding to the retinoblastoma nuclear localization signal to approximately one-half that of wild-type protein. Our data show that compound heterozygous mutations in KPNA7 are associated with a human neurodevelopmental disease, and provide the first example of a human disease associated with mutation of a nuclear transport receptor. PMID:24045845

NR2E3 mutations in enhanced S-cone sensitivity syndrome (ESCS), Goldmann-Favre syndrome (GFS), clumped pigmentary retinal degeneration (CPRD), and retinitis pigmentosa (RP).

PubMed

Schorderet, Daniel F; Escher, Pascal

2009-11-01

NR2E3, also called photoreceptor-specific nuclear receptor (PNR), is a transcription factor of the nuclear hormone receptor superfamily whose expression is uniquely restricted to photoreceptors. There, its physiological activity is essential for proper rod and cone photoreceptor development and maintenance. Thirty-two different mutations in NR2E3 have been identified in either homozygous or compound heterozygous state in the recessively inherited enhanced S-cone sensitivity syndrome (ESCS), Goldmann-Favre syndrome (GFS), and clumped pigmentary retinal degeneration (CPRD). The clinical phenotype common to all these patients is night blindness, rudimental or absent rod function, and hyperfunction of the "blue" S-cones. A single p.G56R mutation is inherited in a dominant manner and causes retinitis pigmentosa (RP). We have established a new locus-specific database for NR2E3 (www.LOVD.nl/eye), containing all reported mutations, polymorphisms, and unclassified sequence variants, including novel ones. A high proportion of mutations are located in the evolutionarily-conserved DNA-binding domains (DBDs) and ligand-binding domains (LBDs) of NR2E3. Based on homology modeling of these NR2E3 domains, we propose a structural localization of mutated residues. The high variability of clinical phenotypes observed in patients affected by NR2E3-linked retinal degenerations may be caused by different disease mechanisms, including absence of DNA-binding, altered interactions with transcriptional coregulators, and differential activity of modifier genes.

Genetics of pulmonary hypertension in the clinic.

PubMed

Girerd, Barbara; Lau, Edmund; Montani, David; Humbert, Marc

2017-09-01

Heritable pulmonary arterial hypertension (PAH) is an autosomal dominant disease with incomplete penetrance because of mutations in bone morphogenetic protein receptor-II (BMPR2), activin A receptor type II-like kinase 1, endoglin, caveolin-1, potassium channel subfamily K, member 3, and T-box gene 4 genes. Heritable pulmonary veno-occlusive disease and/or pulmonary capillary hemangiomatosis (PVOD/PCH) is an autosomal recessive disease because of biallelic mutations in the eukaryotic translation initiation factor 2 alpha kinase 4 gene. The 2015 european society of cardiology (ESC) and european respiratory society (ERS) pulmonary hypertension guidelines recommend genetic counselling and testing to adults and children with PAH or PVOD/PCH as well as in adult relatives at risk of carrying a predisposing mutation. In France, genetic counseling and testing are offered to all patients displaying sporadic or familial form of PAH or PVOD/PCH and to their relatives at high risk of carrying a predisposing mutation. Patients with a heritable form of PAH are younger at diagnosis with a worse hemodynamic and a dismal prognosis. Patients with a heritable form of PVOD/PCH are younger at diagnosis with a worse response to specific PAH therapies. A program to detect PAH in an early phase was offered to all asymptomatic BMPR2 mutation carriers, according to the 2015 ESC/ERS guidelines. Finally, preimplantation genetic diagnosis has been performed in families with a history of BMPR2 mutations. Genetic counseling and testing has to be implemented in pulmonary hypertension centers.

Epidermal growth factor receptor in non-small cell lung cancer

PubMed Central

2015-01-01

Following the identification of a group of patients in the initial tyrosine kinase inhibitor (TKI) trials for lung cancer, there has been detailed focus on which patients may benefit from inhibitor therapy. This article reviews the background, genetics and prevalence of epidermal growth factor mutations in non-small cell lung cancer (NSCLC). Additionally, the prevalence in unselected patients is compared against various other reviews. PMID:25870793

Schizophrenia and the androgen receptor gene: Report of a sibship showing co-segregation with Reifenstein Syndrome but no evidence for linkage in 23 multiply affected families

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arranz, M.; Sharma, T.; Sham, P.

Crow et al. have reported excess sharing of alleles by male sibling pairs with schizophrenia, at a triplet repeat marker within the androgen receptor gene, indicating that mutations at or near this gene may be a risk factor for males. In this report, we describe a pair of male siblings concordant for both schizophrenia and Reifenstein syndrome, which is caused by a mutation in this gene. This provides support for the hypothesis that the androgen receptor may contribute to liability to develop schizophrenia. Because of this, we have examined a collection of 23 pedigrees multiply affected by schizophrenia for linkagemore » to the androgen receptor. We have found no evidence for linkage by both the LOD score and affected sibling-pair methods, under a range of genetic models with a broad and narrow definition of phenotype, and when families with male-to-male transmission are excluded. However, because of the small number of informative male-male pairs in our sample, we cannot confirm or refute the excess allele sharing for males reported by Crow. 35 refs., 1 fig., 2 tabs.« less

EGFR molecular profiling in advanced NSCLC: a prospective phase II study in molecularly/clinically selected patients pretreated with chemotherapy.

PubMed

Milella, Michele; Nuzzo, Carmen; Bria, Emilio; Sperduti, Isabella; Visca, Paolo; Buttitta, Fiamma; Antoniani, Barbara; Merola, Roberta; Gelibter, Alain; Cuppone, Federica; D'Alicandro, Valerio; Ceribelli, Anna; Rinaldi, Massimo; Cianciulli, Anna; Felicioni, Lara; Malatesta, Sara; Marchetti, Antonio; Mottolese, Marcella; Cognetti, Francesco

2012-04-01

The optimal use of epidermal growth factor receptor (EGFR)-related molecular markers to prospectively identify tyrosine kinase inhibitor (TKI)-sensitive patients, particularly after a previous chemotherapy treatment, is currently under debate. We designed a prospective phase II study to evaluate the activity of EGFR-TKI in four different patient groups, according to the combination of molecular (EGFR gene mutations, EGFR gene copy number and protein expression, and phosphorylated AKT expression, pAKT) and clinicopathological (histology and smoking habits) factors. Correlations between molecular alterations and clinical outcome were also explored retrospectively for first-line chemotherapy and EGFR-TKI treatment. Patients who had progressed during or after first-line chemotherapy were prospectively assigned to EGFR-TKI treatment as follows: (G1) EGFR mutation (n = 12); (G2) highly polysomic/amplified EGFR (n = 18); (G3) EGFR and/or pAKT positive (n = 41); (G4) adenocarcinoma/bronchoalveolar carcinoma and no smoking history (n = 15). G1 and G4 had the best and second-best overall response rate (25% and 20%, respectively), whereas the worst outcome was observed in G2 (ORR, 6%; p = 0.05). Disease control was highest in G1 and G4 (>50%) and lowest in G3 (<20%) (p = 0.02). Patients selected by EGFR mutation or clinical parameters (G1 and G4) also had significantly better progression-free survival and overall survival (p = 0.02 and p = 0.01, respectively). Multivariate analysis confirmed the impact of sex, smoking history, EGFR/KRAS mutation, and pAKT on outcomes and allowed us to derive an efficient predictive model. Histology, EGFR mutations, and pAKT were independent predictors of response to first-line chemotherapy at retrospective analysis, whereas pAKT and human epidermal growth factor receptor 2 expression were the only independent predictors of progression-free survival and overall survival. Selection of patients based on either EGFR mutation or clinical characteristics seems an effective approach to optimize EGFR-TKI treatment in chemotherapy-pretreated non-small-cell lung cancer patients.

Insilico modeling and molecular dynamic simulation of claudin-1 point mutations in HCV infection.

PubMed

Vipperla, Bhavaniprasad; Dass, J Febin Prabhu; Jayanthi, S

2014-01-01

Claudin-1 (CLDN1) in association with envelope glycoprotein (CD81) mediates the fusion of HCV into the cytosol. Recent studies have indicated that point mutations in CLDN1 are important for the entry of hepatitis C virus (HCV). To validate these findings, we employed a computational platform to investigate the structural effect of two point mutations (I32M and E48K). Initially, three-dimensional co-ordinates for CLDN1 receptor sequence were generated. Then, three mutant models were built using the point mutation including a double mutant (I32M/E48K) model from the native model structure. Finally, all the four model structures including the native and three mutant models were subjected to molecular dynamics (MD) simulation for a period of 25 ns to appreciate their dynamic behavior. The MD trajectory files were analyzed using cluster and principal component method. The analysis suggested that either of the single mutation has negligible effect on the overall structure of CLDN1 compared to the double mutant form. However, the double mutant model of CLDN1 shows significant negative impact through the impairment of H-bonds and the simultaneous increase in solvent accessible surface area. Our simulation results are visibly consistent with the experimental report suggesting that the CLDN1 receptor distortion is prominent due to the double mutation with large surface accessibility. This increase in accessible surface area due to the coexistence of double mutation may be presumed as one of the key factor that results in permissive action of HCV attachment and infection.

Update on the molecular biology of dyslipidemias.

PubMed

Ramasamy, I

2016-02-15

Dyslipidemia is a commonly encountered clinical condition and is an important determinant of cardiovascular disease. Although secondary factors play a role in clinical expression, dyslipidemias have a strong genetic component. Familial hypercholesterolemia is usually due to loss-of-function mutations in LDLR, the gene coding for low density lipoprotein receptor and genes encoding for proteins that interact with the receptor: APOB, PCSK9 and LDLRAP1. Monogenic hypertriglyceridemia is the result of mutations in genes that regulate the metabolism of triglyceride rich lipoproteins (eg LPL, APOC2, APOA5, LMF1, GPIHBP1). Conversely familial hypobetalipoproteinemia is caused by inactivation of the PCSK9 gene which increases the number of LDL receptors and decreases plasma cholesterol. Mutations in the genes APOB, and ANGPTL3 and ANGPTL4 (that encode angiopoietin-like proteins which inhibit lipoprotein lipase activity) can further cause low levels of apoB containing lipoproteins. Abetalipoproteinemia and chylomicron retention disease are due to mutations in the microsomal transfer protein and Sar1b-GTPase genes, which affect the secretion of apoB containing lipoproteins. Dysbetalipoproteinemia stems from dysfunctional apoE and is characterized by the accumulation of remnants of chylomicrons and very low density lipoproteins. ApoE deficiency can cause a similar phenotype or rarely mutations in apoE can be associated with lipoprotein glomerulopathy. Low HDL can result from mutations in a number of genes regulating HDL production or catabolism; apoAI, lecithin: cholesterol acyltransferase and the ATP-binding cassette transporter ABCA1. Patients with cholesteryl ester transfer protein deficiency have markedly increased HDL cholesterol. Both common and rare genetic variants contribute to susceptibility to dyslipidemias. In contrast to rare familial syndromes, in most patients, dyslipidemias have a complex genetic etiology consisting of multiple genetic variants as established by genome wide association studies. Secondary factors, obesity, metabolic syndrome, diabetes, renal disease, estrogen and antipsychotics can increase the likelihood of clinical presentation of an individual with predisposed genetic susceptibility to hyperlipoproteinemia. The genetic profiles studied are far from complete and there is room for further characterization of genes influencing lipid levels. Genetic assessment can help identify patients at risk for developing dyslipidemias and for treatment decisions based on 'risk allele' profiles. This review will present the current information on the genetics and pathophysiology of disorders that cause dyslipidemias. Copyright © 2015 Elsevier B.V. All rights reserved.

Alterations in epidermal growth factor receptors 1 and 2 in esophageal squamous cell carcinomas

PubMed Central

2012-01-01

Background Esophageal squamous cell carcinoma (ESCC) shows a 5-year survival rate below 10%, demonstrating the urgency in improving its treatment. Alterations in epidermal growth factor receptors are closely related to malignancy transformation in a number of tumors and recent successful targeted therapies have been directed to these molecules. Therefore, in this study, we analyzed the expression of EGFR and HER2 and evaluated EGFR mutation profile as well as the presence of mutations in hotspots of KRAS and BRAF in ESCC patients. Methods We performed RT-qPCR, immunohistochemistry and Fluorescent in situ hybridization to determine EGFR and HER2 expression in ESCC patients, and direct sequencing and PCR-RFLP for mutations and polymorphism analysis. Results Our results showed an increased EGFR mRNA expression in tumors compared to surrounding tissue (p <0.05), with 11% of the cases presenting at least a four-fold difference between tumor and paired adjacent mucosa. EGFR protein overexpression was present only in 4% of the cases. The median expression of HER2 mRNA was not different between tumors and adjacent mucosa. Still, 7% of the tumors presented at least a 25-fold higher expression of this gene when compared to its paired counterpart. Immunohistochemical analysis revealed that 21% of the tumors were positive for HER2 (scores 2+ and 3+), although only 3+ tumors presented amplification of this gene. Mutation analysis for EGFR (exons 18-21), KRAS (codons 12 and 13) and BRAF (V600E) showed no mutations in any of the hotspots of these genes in almost 100 patients analyzed. EGFR presented synonymous polymorphisms at codon 836 (C>T) in 2.1% of the patients, and at codon 787 (G>A) in 79.2% of the cases. This last polymorphism was also evaluated in 304 healthy controls, which presented a similar frequency (73.7%) in comparison with ESCC patients. The absence of mutations of EGFR, KRAS and BRAF as well as the overexpression of EGFR and HER2 in less than 10% of the patients suggest that this signaling pathway is altered in only a small proportion of patients with ESCC. Conclusion HER receptors target therapies may have the potential to be effective in only a minor fraction of patients with ESCC. PMID:23207070

Functional characterization of c-Mpl ectodomain mutations that underlie congenital amegakaryocytic thrombocytopenia.

PubMed

Varghese, Leila N; Zhang, Jian-Guo; Young, Samuel N; Willson, Tracy A; Alexander, Warren S; Nicola, Nicos A; Babon, Jeffrey J; Murphy, James M

2014-02-01

Activation of the cell surface receptor, c-Mpl, by the cytokine, thrombopoietin (TPO), underpins megakaryocyte and platelet production in mammals. In humans, mutations in c-Mpl have been identified as the molecular basis of Congenital Amegakaryocytic Thrombocytopenia (CAMT). Here, we show that CAMT-associated mutations in c-Mpl principally lead to defective receptor presentation on the cell surface. In contrast, one CAMT mutant c-Mpl, F104S, was expressed on the cell surface, but showed defective TPO binding and receptor activation. Using mutational analyses, we examined which residues adjacent to F104 within the membrane-distal cytokine receptor homology module (CRM) of c-Mpl comprise the TPO-binding epitope, revealing residues within the predicted Domain 1 E-F and A-B loops and Domain 2 F'-G' loop as key TPO-binding determinants. These studies underscore the importance of the c-Mpl membrane-distal CRM to TPO-binding and suggest that mutations within this CRM that perturb TPO binding could give rise to CAMT.

Presence of pleural effusion is associated with a poor prognosis in patients with epidermal growth factor receptor-mutated lung cancer receiving tyrosine kinase inhibitors as first-line treatment.

PubMed

Wang, Tso-Fu; Chu, Sung-Chao; Lee, Jen-Jyh; Yang, Gee-Gwo; Huang, Wei-Han; Chang, En-Ting; Low, Tissot; Wu, Yi-Feng; Kao, Ruey-Ho; Lin, Chih-Bin

2017-08-01

This study was conducted to evaluate the effect of clinical factors on the treatment outcomes of lung cancer patients with active epidermal growth factor receptor (EGFR) mutations treated by first-line tyrosine kinase inhibitors (TKIs). Patients of stage IIIb or IV lung adenocarcinoma harboring mutated EGFR were enrolled between March 2010 and June 2014 and followed up until December 2015. The effects of various clinical features, such as age, sex, smoking history, EGFR mutation types, TKIs used, presence of pleural effusion, metastatic sites on progression-free survival (PFS) and overall survival (OS), were analyzed retrospectively. A total of 104 patients were included in this study. Patients with pleural effusion at initial diagnosis had significantly shorter PFS and OS than those without pleural effusion (median PFS: 8.2 months vs 15.3 months, P = 0.0004; median OS: 16.3 months vs 28.2 months, P = 0.0003). Univariate analysis revealed that being male or a smoker was associated with short PFS, whereas smoking history, bony metastasis and malignant pleural effusion were associated with poor OS. Stepwise multivariate Cox regression analysis showed that the presence of pleural effusion and different TKI use were independent prognostic factors for PFS [hazard ratio [HR] = 2.50 (95% confidence interval [CI], 1.53-4.10), P = 0.0003 and HR = 0.55 (95% CI, 0.31-0.97), P = 0.0396, respectively], whereas the presence of pleural effusion and liver metastasis were associated with poor OS [HR = 2.79 (95% CI: 1.46-5.30), P = 0.0018 and HR = 2.12 (95% CI, 1.02-4.40), P = 0.0440, respectively]. The presence of pleural effusion predicts poor PFS and OS in lung adenocarcinoma patients receiving TKIs as the first-line treatment. Additional studies are warranted to elucidate the underlying mechanisms and determine novel strategies for improving the outcome of these patients. © 2017 John Wiley & Sons Australia, Ltd.

The majority of ACTH receptor (MC2R) mutations found in Familial Glucocorticoid Deficiency type 1 lead to defective trafficking of the receptor to the cell surface

PubMed Central

TT, Chung; TR, Webb; LF, Chan; SN, Cooray; LA, Metherell; PJ, King; JP, Chapple; AJL, Clark

2008-01-01

Context: There are at least twenty-four missense, non-conservative mutations found in the ACTH receptor (Melanocortin 2 receptor, MC2R) which have been associated with the autosomal recessive disease Familial Glucocorticoid Deficiency (FGD) type 1. The characterization of these mutations has been hindered by difficulties in establishing a functional heterologous cell transfection system for MC2R. Recently the melanocortin 2 receptor accessory protein (MRAP) was identified as essential for trafficking of MC2R to the cell surface; therefore a functional characterization of MC2R mutations is now possible. Objective: To elucidate the molecular mechanisms responsible for defective MC2R function in FGD. Methods: Stable cell lines expressing human MRAPα were established and transiently transfected with wild-type or mutant MC2R. Functional characterization of mutant MC2R was performed using a cell surface expression assay, a cAMP reporter assay, confocal microscopy and co-immunoprecipitation of MRAPα. Results: Two thirds of all MC2R mutations had a significant reduction in cell surface trafficking even though MRAPα interacted with all mutants. Analysis of those mutant receptors that reached the cell surface indicated that 4/6 failed to signal, following stimulation with ACTH. Conclusion: The majority of MC2R mutations found in FGD fail to function because they fail to traffic to the cell surface. PMID:18840636

Classical and atypical agonists activate M1 muscarinic acetylcholine receptors through common mechanisms.

PubMed

Randáková, Alena; Dolejší, Eva; Rudajev, Vladimír; Zimčík, Pavel; Doležal, Vladimír; El-Fakahany, Esam E; Jakubík, Jan

2015-07-01

We mutated key amino acids of the human variant of the M1 muscarinic receptor that target ligand binding, receptor activation, and receptor-G protein interaction. We compared the effects of these mutations on the action of two atypical M1 functionally preferring agonists (N-desmethylclozapine and xanomeline) and two classical non-selective orthosteric agonists (carbachol and oxotremorine). Mutations of D105 in the orthosteric binding site and mutation of D99 located out of the orthosteric binding site decreased affinity of all tested agonists that was translated as a decrease in potency in accumulation of inositol phosphates and intracellular calcium mobilization. Mutation of D105 decreased the potency of the atypical agonist xanomeline more than that of the classical agonists carbachol and oxotremorine. Mutation of the residues involved in receptor activation (D71) and coupling to G-proteins (R123) completely abolished the functional responses to both classical and atypical agonists. Our data show that both classical and atypical agonists activate hM1 receptors by the same molecular switch that involves D71 in the second transmembrane helix. The principal difference among the studied agonists is rather in the way they interact with D105 in the orthosteric binding site. Furthermore, our data demonstrate a key role of D105 in xanomeline wash-resistant binding and persistent activation of hM1 by wash-resistant xanomeline. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Single strand conformation polymorphism analysis of androgen receptor gene mutations in patients with androgen insensitivity syndromes: Application for diagnosis, genetic counseling, and therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hiort, O.; Huang, Q.; Sinnecker, G.H.G.

Recent studies indicate that mutations in the androgen receptor gene are associated with androgen insensitivity syndromes, a heterogeneous group of related disorders involving defective sexual differentiation in karyotypic males. In this report, the authors address the possibility of rapid mutational analysis of the androgen receptor gene for initial diagnosis, genetic counseling, and molecular subclassification of affected patients and their families. DNA from peripheral blood leukocytes of six patients from five families with various degrees of androgen insensitivity was studied. Exons 2 to 8 of the androgen receptor gene were analyzed using a combination of single strand conformation polymorphism analysis andmore » direct DNA sequencing. Female family members were also studied to identify heterozygote carriers. Point mutations in the AR gene were identified in all six patients, and all mutations caused amino acid substitutions. One patient with incomplete androgen insensitivity was a mosaic for the mutation. Four of the five mothers, as well as a young sister of one patient, were carriers of the mutation present in the affected child. The data show that new mutations may occur in the androgen receptor gene leading to sporadic androgen insensitivity syndrome. Molecular genetic characterization of the variant allele can serve as a primary tool for diagnosis and subsequent therapy, and can provide a basis for distinguishing heterozygous carriers in familial androgen resistance. The identification of carriers is of substantial clinical importance for genetic counseling. 29 refs., 2 figs., 1 tab.« less

Peptide processing and biology in human disease

PubMed Central

Kovac, Suzana; Shulkes, Arthur; Baldwin, Graham S.

2008-01-01

Purpose of review To describe recent advances in the processing of gastrointestinal hormones, and the consequences for human disease of mutations in the enzymes involved. Recent findings Although gastrointestinal prohormones were long regarded as devoid of biological activity, recent data indicates that the prohormones for both gastrin and gastrin-releasing peptide are bioactive, through different receptors from the mature hormones. Mutations in the family of prohormone convertases responsible for the initial steps in the processing of gastrointestinal hormones are associated with several different pathophysiological conditions in humans. Summary Human mutational studies, when taken together with the phenotypes observed in mice deficient in the prohormone convertases, emphasize the crucial importance of the processing enzymes in mammalian biology. Although the phenotypes may often be ascribed to defective production of a mature hormone or growth factor, the recognition that the precursors are independently bioactive suggests that the increased precursor concentrations may also contribute to the symptoms. The observation that the precursors often act through different receptors from the mature hormones may permit the development of precursor-selective antagonists for therapeutic use. PMID:19104240

Challenges and Perspectives on the Development of Small-Molecule EGFR Inhibitors against T790M-Mediated Resistance in Non-Small-Cell Lung Cancer.

PubMed

Song, Zhendong; Ge, Yang; Wang, Changyuan; Huang, Shanshan; Shu, Xiaohong; Liu, Kexin; Zhou, Youwen; Ma, Xiaodong

2016-07-28

Because of the development of drug-resistance mutations, particularly the "gatekeeper" threonine(790)-to-methionine(790) (T790M) mutation in the ATP-binding pocket of the epidermal growth factor receptor (EGFR), the current generation of EGFR tyrosine kinase inhibitors lost their clinical efficacy. Recently, a large number of small-molecule inhibitors with striking inhibitory potency against EGFR mutants with the T790M change have been identified. In particular, the inhibitors rociletinib and osimertinib, which can selectively target both sensitizing mutations and the T790M resistance while sparing the wild-type (WT) form of the receptor, have been designated as breakthrough therapies in the treatment of mutant non-small-cell lung cancer (NSCLC) by the U.S. FDA in 2014. We hope that this review on the small-molecule EGFR T790M inhibitors, along with their discovery strategies, will assist in the design of future T790M-containing EGFR inhibitors with high levels of selectivity over WT EGFR, broad kinase selectivity, and desirable physicochemical properties.

Genetic factors in fetal growth restriction and miscarriage.

PubMed

Yamada, Hideto; Sata, Fumihiro; Saijo, Yasuaki; Kishi, Reiko; Minakami, Hisanori

2005-06-01

Recently, several investigations concerning disadvantageous genetic factors in human reproduction have progressed. Inherited thrombophilia, such as factor V Leiden, prothrombin, and methylenetetrahydrofolate reductase mutations; gene polymorphisms of detoxification enzyme (CYP1A1); growth factors (insulin-like growth factor-I); and hormones such as angiotensinogen and CYP17 are involved in the pathogenesis of fetal growth restriction. The inherited thrombophilia, gene polymorphisms of coagulation and anticoagulation factor such as thrombomodulin, endothelial protein C receptor, plasminogen activator inhibitor 1, and factor XIII; human lymphocyte antigen (HLA-G); detoxification enzymes (glutathione- S-transferase M1); cytokines such as interleukin (IL) -1 and IL-6; hormones (CYP17); vasodilators (nitric oxide synthase 3); and vitamins (transcobalamin) are involved in the pathogenesis of sporadic and recurrent miscarriage. It is likely that a gene polymorphism or mutation susceptible to reproductive failure has a beneficial effect on the process of human reproduction with or without the environmental interaction. The factor V Leiden mutation has genetic advantages that are believed to be an improved implantation rate in in vitro fertilization and a reduction of maternal intrapartum blood loss. It has also been demonstrated that the CYP17 A2 allele has bidirectional effects on human reproduction, including increases in susceptibility to recurrent miscarriage and fetal growth enhancement.

Phosphorylation of the Activation Loop Tyrosine 823 in c-Kit Is Crucial for Cell Survival and Proliferation*

PubMed Central

Agarwal, Shruti; Kazi, Julhash U.; Rönnstrand, Lars

2013-01-01

The receptor tyrosine kinase c-Kit, also known as the stem cell factor receptor, plays a key role in several developmental processes. Activating mutations in c-Kit lead to alteration of these cellular processes and have been implicated in many human cancers such as gastrointestinal stromal tumors, acute myeloid leukemia, testicular seminomas and mastocytosis. Regulation of the catalytic activity of several kinases is known to be governed by phosphorylation of tyrosine residues in the activation loop of the kinase domain. However, in the case of c-Kit phosphorylation of Tyr-823 has been demonstrated to be a late event that is not required for kinase activation. However, because phosphorylation of Tyr-823 is a ligand-activated event, we sought to investigate the functional consequences of Tyr-823 phosphorylation. By using a tyrosine-to-phenylalanine mutant of tyrosine 823, we investigated the impact of Tyr-823 on c-Kit signaling. We demonstrate here that Tyr-823 is crucial for cell survival and proliferation and that mutation of Tyr-823 to phenylalanine leads to decreased sustained phosphorylation and ubiquitination of c-Kit as compared with the wild-type receptor. Furthermore, the mutated receptor was, upon ligand-stimulation, quickly internalized and degraded. Phosphorylation of the E3 ubiquitin ligase Cbl was transient, followed by a substantial reduction in phosphorylation of downstream signaling molecules such as Akt, Erk, p38, Shc, and Gab2. Thus, we propose that activation loop tyrosine 823 is crucial for activation of both the MAPK and PI3K pathways and that its disruption leads to a destabilization of the c-Kit receptor and decreased survival of cells. PMID:23803604

A Genetic Basis for Functional Hypothalamic Amenorrhea

PubMed Central

Caronia, Lisa M.; Martin, Cecilia; Welt, Corrine K.; Sykiotis, Gerasimos P.; Quinton, Richard; Thambundit, Apisadaporn; Avbelj, Magdalena; Dhruvakumar, Sadhana; Plummer, Lacey; Hughes, Virginia A.; Seminara, Stephanie B.; Boepple, Paul A.; Sidis, Yisrael; Crowley, William F.; Martin, Kathryn A.; Hall, Janet E.; Pitteloud, Nelly

2011-01-01

BACKGROUND Functional hypothalamic amenorrhea is a reversible form of gonadotropin-releasing hormone (GnRH) deficiency commonly triggered by stressors such as excessive exercise, nutritional deficits, or psychological distress. Women vary in their susceptibility to inhibition of the reproductive axis by such stressors, but it is unknown whether this variability reflects a genetic predisposition to hypothalamic amenorrhea. We hypothesized that mutations in genes involved in idiopathic hypogonadotropic hypogonadism, a congenital form of GnRH deficiency, are associated with hypothalamic amenorrhea. METHODS We analyzed the coding sequence of genes associated with idiopathic hypogonadotropic hypogonadism in 55 women with hypothalamic amenorrhea and performed in vitro studies of the identified mutations. RESULTS Six heterozygous mutations were identified in 7 of the 55 patients with hypothalamic amenorrhea: two variants in the fibroblast growth factor receptor 1 gene FGFR1 (G260E and R756H), two in the prokineticin receptor 2 gene PROKR2 (R85H and L173R), one in the GnRH receptor gene GNRHR (R262Q), and one in the Kall-mann syndrome 1 sequence gene KAL1 (V371I). No mutations were found in a cohort of 422 controls with normal menstrual cycles. In vitro studies showed that FGFR1 G260E, FGFR1 R756H, and PROKR2 R85H are loss-of-function mutations, as has been previously shown for PROKR2 L173R and GNRHR R262Q. CONCLUSIONS Rare variants in genes associated with idiopathic hypogonadotropic hypogonadism are found in women with hypothalamic amenorrhea, suggesting that these mutations may contribute to the variable susceptibility of women to the functional changes in GnRH secretion that characterize hypothalamic amenorrhea. Our observations provide evidence for the role of rare variants in common multifactorial disease. (Funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development and others; ClinicalTrials.gov number, NCT00494169.) PMID:21247312

A genetic basis for functional hypothalamic amenorrhea.

PubMed

Caronia, Lisa M; Martin, Cecilia; Welt, Corrine K; Sykiotis, Gerasimos P; Quinton, Richard; Thambundit, Apisadaporn; Avbelj, Magdalena; Dhruvakumar, Sadhana; Plummer, Lacey; Hughes, Virginia A; Seminara, Stephanie B; Boepple, Paul A; Sidis, Yisrael; Crowley, William F; Martin, Kathryn A; Hall, Janet E; Pitteloud, Nelly

2011-01-20

Functional hypothalamic amenorrhea is a reversible form of gonadotropin-releasing hormone (GnRH) deficiency commonly triggered by stressors such as excessive exercise, nutritional deficits, or psychological distress. Women vary in their susceptibility to inhibition of the reproductive axis by such stressors, but it is unknown whether this variability reflects a genetic predisposition to hypothalamic amenorrhea. We hypothesized that mutations in genes involved in idiopathic hypogonadotropic hypogonadism, a congenital form of GnRH deficiency, are associated with hypothalamic amenorrhea. We analyzed the coding sequence of genes associated with idiopathic hypogonadotropic hypogonadism in 55 women with hypothalamic amenorrhea and performed in vitro studies of the identified mutations. Six heterozygous mutations were identified in 7 of the 55 patients with hypothalamic amenorrhea: two variants in the fibroblast growth factor receptor 1 gene FGFR1 (G260E and R756H), two in the prokineticin receptor 2 gene PROKR2 (R85H and L173R), one in the GnRH receptor gene GNRHR (R262Q), and one in the Kallmann syndrome 1 sequence gene KAL1 (V371I). No mutations were found in a cohort of 422 controls with normal menstrual cycles. In vitro studies showed that FGFR1 G260E, FGFR1 R756H, and PROKR2 R85H are loss-of-function mutations, as has been previously shown for PROKR2 L173R and GNRHR R262Q. Rare variants in genes associated with idiopathic hypogonadotropic hypogonadism are found in women with hypothalamic amenorrhea, suggesting that these mutations may contribute to the variable susceptibility of women to the functional changes in GnRH secretion that characterize hypothalamic amenorrhea. Our observations provide evidence for the role of rare variants in common multifactorial disease. (Funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development and others; ClinicalTrials.gov number, NCT00494169.).

Mechanisms of resistance to irreversible epidermal growth factor receptor tyrosine kinase inhibitors and therapeutic strategies in non-small cell lung cancer

PubMed Central

Xu, Jing; Wang, Jinghui; Zhang, Shucai

2017-01-01

Epidermal growth factor receptor (EGFR) T790M mutation is the most frequent mechanism which accounts for about 60% of acquired resistance to first-generation EGFR tyrosine kinase inhibitors (TKIs) in non-small cell lung cancer (NSCLC) patients harboring EGFR activating mutations. Irreversible EGFR-TKIs which include the second-generation and third-generation EGFR-TKIs are developed to overcome T790M mediated resistance. The second-generation EGFR-TKIs inhibit the wide type (WT) EGFR combined with dose-limiting toxicity which limits its application in clinics, while the development of third-generation EGFR-TKIs brings inspiring efficacy either in vitro or in vivo. The acquired resistance, however, will also occur and limit their response. Understanding the mechanisms of resistance to irreversible EGFR-TKIs plays an important role in the choice of subsequent treatment. In this review, we show the currently known mechanisms of resistance which can be summarized as EGFR dependent and independent mechanisms and potential therapeutic strategies to irreversible EGFR-TKIs. PMID:29163853

Inactivation of the first nucleotide-binding fold of the sulfonylurea receptor, and familial persistent hyperinsulinemic hypoglycemia of infancy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thomas, P.M.; Wohllk, N.; Huang, E.

1996-09-01

Familial persistent hyperinsulinemic hypoglycemia of infancy is a disorder of glucose homeostasis and is characterized by unregulated insulin secretion and profound hypoglycemia. Loss-of-function mutations in the second nucleotide-binding fold of the sulfonylurea receptor, a subunit of the pancreatic-islet {beta}-cell ATP-dependent potassium channel, has been demonstrated to be causative for persistent hyperinsulinemic hypoglycemia of infancy. We now describe three additional mutations in the first nucleotide-binding fold of the sulfonylurea-receptor gene. One point mutation disrupts the highly conserved Walker A motif of the first nucleotide-binding-fold region. The other two mutations occur in noncoding sequences required for RNA processing and are predicted tomore » disrupt the normal splicing pathway of the sulfonylurea-receptor mRNA precursor. These data suggest that both nucleotide-binding-fold regions of the sulfortylurea receptor are required for normal regulation of {beta}-cell ATP-dependent potassium channel activity and insulin secretion. 32 refs., 4 figs., 1 tab.« less

Clinical features and growth hormone receptor gene mutations of patients with Laron syndrome from a Chinese family.

PubMed

Ying, Yan-Qin; Wei, Hong; Cao, Li-Zhi; Lu, Juan-Juan; Luo, Xiao-Ping

2007-08-01

Laron syndrome is an autosomal recessive disorder caused by defects of growth hormone receptor (GHR) gene. It is characterized by severe postnatal growth retardation and characteristic facial features as well as high circulating levels of growth hormone (GH) and low levels of insulin-like growth factor I (IGF-I) and insulin-like growth factor binding protein-3 (IGFBP-3). This report described the clinical features and GHR gene mutations in 2 siblings with Laron syndrome in a Chinese family. Their heights and weights were in the normal range at birth, but the growth was retarded after birth. When they presented to the clinic, the heights of the boy (8 years old) and his sister (11 years old) were 80.0 cm (-8.2 SDS) and 96.6 cm (-6.8 SDS) respectively. They had typical appearance features of Laron syndrome such as short stature and obesity, with protruding forehead, saddle nose, large eyes, sparse and thin silky hair and high-pitched voice. They had higher basal serum GH levels and lower serum levels of IGF-I, IGFBP-3 and growth hormone binding protein (GHBP) than normal controls. The peak serum GH level after colonidine and insulin stimulations in the boy was over 350 ng/mL. After one-year rhGH treatment, the boy's height increased from 80.0 cm to 83.3 cm. The gene mutation analysis revealed that two patients had same homozygous mutation of S65H (TCA -->CCA) in exon 4, which is a novel gene mutation. It was concluded that a definite diagnosis of Laron syndrome can be made based on characteristic appearance features and serum levels of GH, IGF-I, IGFBP-3 and GHBP. The S65H mutation might be the cause of Laron syndrome in the two patients.

Complete response in gallbladder cancer to erlotinib plus gemcitabine does not require mutation of the epidermal growth factor receptor gene: a case report.

PubMed

Mody, Kabir; Strauss, Edward; Lincer, Robert; Frank, Richard C

2010-10-20

Gallbladder cancer typically follows an aggressive course, with chemotherapy the standard of care for advanced disease; complete remissions are rarely encountered. The epidermal growth factor receptor (EGFR) is a promising therapeutic target but the activity of single agent oral EGFR tyrosine kinase inhibitors is low. There have been no previous reports of chemotherapy plus an EGFR-tyrosine kinase inhibitor (TKI) to treat gallbladder cancer or correlations of response with the mutation status of the tyrosine kinase domain of the EGFR gene. A 67 year old man with metastatic gallbladder cancer involving the liver and abdominal lymph nodes was treated with gemcitabine (1000 mg/m2) on day 1 and 8 every 21 days as well as daily erlotinib (100 mg). After four cycles of therapy, the CA 19-9 normalized and a PET/CT showed a complete remission; this response was maintained by the end of 12 cycles of therapy. Gemcitabine was then discontinued and single agent erlotinib was continued as maintenance therapy. The disease remains in good control 18 months after initiation of therapy, including 6 months on maintenance erlotinib. The only grade 3 toxicity was a typical EGFR-related skin rash. Because of the remarkable response to erlotinib plus gemcitabine, we performed tumor genotyping of the EGFR gene for response predicting mutations in exons 18, 19 and 21. This disclosed the wild-type genotype with no mutations found. This case report demonstrates a patient with stage IV gallbladder cancer who experienced a rarely encountered complete, prolonged response after treatment with an oral EGFR-TKI plus chemotherapy. This response occurred in the absence of an EGFR gene mutation. These observations should inform the design of clinical trials using EGFR-TKIs to treat gallbladder and other biliary tract cancers; such trials should not select patients based on EGFR mutation status.

Non-conventional Frizzled ligands and Wnt receptors.

PubMed

Hendrickx, Marijke; Leyns, Luc

2008-05-01

The Wnt family of secreted signaling factors plays numerous roles in embryonic development and in stem cell biology. In the adult, Wnt signaling is involved in tissue homeostasis and mutations that lead to the overexpression of Wnt can be linked to cancer. Wnt signaling is transduced intracellularly by the Frizzled (Fzd) family of receptors. In the canonical pathway, accumulation of beta-catenin and the subsequent formation of a complex with T cell factors (TCF) or lymphoid enhancing factors (Lef) lead to target gene activation. The identification of Ryk as an alternative Wnt receptor and the discovery of the novel Fzd ligands Norrie disease protein (NDP) and R-Spondin, changed the traditional view of Wnts binding to Fzd receptors. Mouse R-Spondin cooperates with Wnt signaling and Low density lipoprotein (LDL) receptor related protein (LRP) to activate beta-catenin dependent gene expression and is involved in processes such as limb and placental development in the mouse. NDP is the product of the Norrie disease gene and controls vascular development in the retina, inner ear and in the female reproductive system during pregnancy. In this review a functional overview of the interactions of the different Wnt and non-Wnt ligands with the Fzd receptors is given as well as a survey of Wnts binding to Ryk and we discuss the biological significance of these interactions.

Peptide hormones and lung cancer.

PubMed

Moody, T W

2006-03-01

Several peptide hormones have been identified which alter the proliferation of lung cancer. Small cell lung cancer (SCLC), which is a neuroendocrine cancer, produces and secretes gastrin releasing peptide (GRP), neurotensin (NT) and adrenomedullin (AM) as autocrine growth factors. GRP, NT and AM bind to G-protein coupled receptors causing phosphatidylinositol turnover or elevated cAMP in SCLC cells. Addition of GRP, NT or AM to SCLC cells causes altered expression of nuclear oncogenes, such as c-fos, and stimulation of growth. Antagonists have been developed for GRP, NT and AM receptors which function as cytostatic agents and inhibit SCLC growth. Growth factor antagonists, such as the NT1 receptor antagonist SR48692, facilitate the ability of chemotherapeutic drugs to kill lung cancer cells. It remains to be determined if GRP, NT and AM receptors will served as molecular targets, for development of new therapies for the treatment of SCLC patients. Non-small cell lung cancer (NSCLC) cells also have a high density of GRP, NT, AM and epidermal growth factor (EGF) receptors. Several NSCLC patients with EGF receptor mutations respond to gefitinib, a tyrosine kinase inhibitor. Gefitinib relieves NSCLC symptoms, maintaining stable disease in patients who are not eligible for systemic chemotherapy. It is important to develop new therapeutic approaches using translational research techniques for the treatment of lung cancer patients.

Germ-line PHD1 and PHD2 mutations detected in patients with pheochromocytoma/paraganglioma-polycythemia.

PubMed

Yang, Chunzhang; Zhuang, Zhengping; Fliedner, Stephanie M J; Shankavaram, Uma; Sun, Michael G; Bullova, Petra; Zhu, Roland; Elkahloun, Abdel G; Kourlas, Peter J; Merino, Maria; Kebebew, Electron; Pacak, Karel

2015-01-01

We have investigated genetic/pathogenetic factors associated with a new clinical entity in patients presenting with pheochromocytoma/paraganglioma (PHEO/PGL) and polycythemia. Two patients without hypoxia-inducible factor 2α (HIF2A) mutations, who presented with similar clinical manifestations, were analyzed for other gene mutations, including prolyl hydroxylase (PHD) mutations. We have found for the first time a germ-line mutation in PHD1 in one patient and a novel germ-line PHD2 mutation in a second patient. Both mutants exhibited reduced protein stability with substantial quantitative protein loss and thus compromised catalytic activities. Due to the unique association of patients' polycythemia with borderline or mildly elevated erythropoietin (EPO) levels, we also performed an in vitro sensitivity assay of erythroid progenitors to EPO and for EPO receptor (EPOR) expression. The results show inappropriate hypersensitivity of erythroid progenitors to EPO in these patients, indicating increased EPOR expression/activity. In addition, the present study indicates that HIF dysregulation due to PHD mutations plays an important role in the pathogenesis of these tumors and associated polycythemia. The PHD1 mutation appears to be a new member contributing to the genetic landscape of this novel clinical entity. Our results support the existence of a specific PHD1- and PHD2-associated PHEO/PGL-polycythemia disorder. • A novel germ-l i n e PHD1 mutation causing heochromocytoma/paraganglioma and polycythemia. • Increased EPOR activity and inappropriate hypersensitivity of erythroid progenitors to EPO.

DIRECT MODULATION OF THE PROTEIN KINASE A CATALYTIC SUBUNIT α BY GROWTH FACTOR RECEPTOR TYROSINE KINASES

PubMed Central

Caldwell, George B.; Howe, Alan K.; Nickl, Christian K.; Dostmann, Wolfgang R.; Ballif, Bryan A.; Deming, Paula B.

2011-01-01

The cyclic-AMP-dependent protein kinase A (PKA) regulates processes such as cell proliferation and migration following activation of growth factor receptor tyrosine kinases (RTKs), yet the signaling mechanisms that link PKA with growth factor receptors remain largely undefined. Here we report that RTKs can directly modulate the function of the catalytic subunit of PKA (PKA-C) through post-translational modification. In vitro kinase assays revealed that both the epidermal growth factor and platelet derived growth factor receptors (EGFR and PDGFR, respectively) tyrosine phosphorylate PKA-C. Mass spectrometry identified tyrosine 330 (Y330) as a receptor-mediated phosphorylation site and mutation of Y330 to phenylalanine (Y330F) all but abolished the RTK-mediated phosphorylation of PKA-C in vitro. Y330 resides within a conserved region at the C-terminal tail of PKA-C that allosterically regulates enzymatic activity. Therefore, the effect of phosphorylation at Y330 on the activity of PKA-C was investigated. The Km for a peptide substrate was markedly decreased when PKA-C subunits were tyrosine phosphorylated by the receptors as compared to un-phosphorylated controls. Importantly, tyrosine-phosphorylated PKA-C subunits were detected in cells stimulated with EGF, PDGF and FGF2 and in fibroblasts undergoing PDGF-mediated chemotaxis. These results demonstrate a direct, functional interaction between RTKs and PKA-C and identify tyrosine phosphorylation as a novel mechansim for regulating PKA activity. PMID:21866565

Mechanisms of resistance to anti-human epidermal growth factor receptor 2 agents in breast cancer.

PubMed

Mukohara, Toru

2011-01-01

Approximately 20% of breast cancers are characterized by overexpression of human epidermal growth factor receptor 2 (HER2) protein and associated gene amplification, and the receptor tyrosine kinase is believed to play a critical role in the pathogenesis of these tumors. The development and implementation of trastuzumab, a humanized monoclonal antibody against the extracellular domain of HER2 protein, has significantly improved treatment outcomes in patients with HER2-overexpressing breast cancer. However, despite this clinical usefulness, unmet needs for better prediction of trastuzumab's response and overcoming primary and acquired resistance remain. In this review, we discuss several potential mechanisms of resistance to trastuzumab that have been closely studied over the last decade. Briefly, these mechanisms include: impaired access of trastuzumab to HER2 by expression of extracellular domain-truncated HER2 (p95 HER2) or overexpression of MUC4; alternative signaling from insulin-like growth factor-1 receptor, other epidermal growth factor receptor family members, or MET; aberrant downstream signaling caused by loss of phosphatase and tensin homologs deleted from chromosome 10 (PTEN), PIK3CA mutation, or downregulation of p27; or FCGR3A polymorphisms. In addition, we discuss potential strategies for overcoming resistance to trastuzumab. Specifically, the epidermal growth factor receptor/HER2 tyrosine kinase inhibitor lapatinib partially overcame trastuzumab resistance in a clinical setting, so its efficacy results and limited data regarding potential mechanisms of resistance to the drug are also discussed. © 2010 Japanese Cancer Association.

Three mutations switch H7N9 influenza to human-type receptor specificity

DOE Office of Scientific and Technical Information (OSTI.GOV)

de Vries, Robert P.; Peng, Wenjie; Grant, Oliver C.

The avian H7N9 influenza outbreak in 2013 resulted from an unprecedented incidence of influenza transmission to humans from infected poultry. The majority of human H7N9 isolates contained a hemagglutinin (HA) mutation (Q226L) that has previously been associated with a switch in receptor specificity from avian-type (NeuAcα2-3Gal) to human-type (NeuAcα2-6Gal), as documented for the avian progenitors of the 1957 (H2N2) and 1968 (H3N2) human influenza pandemic viruses. While this raised concern that the H7N9 virus was adapting to humans, the mutation was not sufficient to switch the receptor specificity of H7N9, and has not resulted in sustained transmission in humans. Tomore » determine if the H7 HA was capable of acquiring human-type receptor specificity, we conducted mutation analyses. Remarkably, three amino acid mutations conferred a switch in specificity for human-type receptors that resembled the specificity of the 2009 human H1 pandemic virus, and promoted binding to human trachea epithelial cells.« less

WHIM syndrome caused by a single amino acid substitution in the carboxy-tail of chemokine receptor CXCR4

PubMed Central

Liu, Qian; Chen, Haoqian; Ojode, Teresa; Gao, Xiangxi; Anaya-O'Brien, Sandra; Turner, Nicholas A.; Ulrick, Jean; DeCastro, Rosamma; Kelly, Corin; Cardones, Adela R.; Gold, Stuart H.; Hwang, Eugene I.; Wechsler, Daniel S.; Malech, Harry L.; Murphy, Philip M.

2012-01-01

WHIM syndrome is a rare, autosomal dominant, immunodeficiency disorder so-named because it is characterized by warts, hypogammaglobulinemia, infections, and myelokathexis (defective neutrophil egress from the BM). Gain-of-function mutations that truncate the C-terminus of the chemokine receptor CXCR4 by 10-19 amino acids cause WHIM syndrome. We have identified a family with autosomal dominant inheritance of WHIM syndrome that is caused by a missense mutation in CXCR4, E343K (1027G → A). This mutation is also located in the C-terminal domain, a region responsible for negative regulation of the receptor. Accordingly, like CXCR4R334X, the most common truncation mutation in WHIM syndrome, CXCR4E343K mediated approximately 2-fold increased signaling in calcium flux and chemotaxis assays relative to wild-type CXCR4; however, CXCR4E343K had a reduced effect on blocking normal receptor down-regulation from the cell surface. Therefore, in addition to truncating mutations in the C-terminal domain of CXCR4, WHIM syndrome may be caused by a single charge-changing amino acid substitution in this domain, E343K, that results in increased receptor signaling. PMID:22596258

Quantification of mutation-derived bias for alternate mating functionalities of the Saccharomyces cerevisiae Ste2p pheromone receptor.

PubMed

Choudhary, Pooja; Loewen, Michele C

2016-01-01

Although well documented for mammalian G-protein-coupled receptors, alternate functionalities and associated alternate signalling remain to be unequivocally established for the Saccharomyces cerevisiae pheromone Ste2p receptor. Here, evidence supporting alternate functionalities for Ste2p is re-evaluated, extended and quantified. In particular, strong mating and constitutive signalling mutations, focusing on residues S254, P258 and S259 in TM6 of Ste2p, are stacked and investigated in terms of their effects on classical G-protein-mediated signal transduction associated with cell cycle arrest, and alternatively, their impact on downstream mating projection and zygote formation events. In relative dose response experiments, accounting for systemic and observational bias, mutational-derived functional differences were observed, validating the S254L-derived bias for downstream mating responses and highlighting complex relationships between TM6-mutation derived constitutive signalling and ligand-induced functionalities. Mechanistically, localization studies suggest that alterations to receptor trafficking may contribute to mutational bias, in addition to expected receptor conformational stabilization effects. Overall, these results extend previous observations and quantify the contributions of Ste2p variants to mediating cell cycle arrest versus downstream mating functionalities. © Crown copyright 2015.

Epidermal growth factor receptor gene amplification in surgical resected Japanese lung cancer.

PubMed

Sasaki, Hidefumi; Shimizu, Shigeki; Okuda, Katsuhiro; Kawano, Osamu; Yukiue, Haruhiro; Yano, Motoki; Fujii, Yoshitaka

2009-06-01

To evaluate the epidermal growth factor receptor (EGFR) protein expression and increased copy number as predictors of clinical outcome in patients with non-small-cell lung cancer (NSCLC), we have performed fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC). We investigated the EGFR increased copy number and EGFR protein expression statuses in 109 surgically treated NSCLC cases. The presence or absence of EGFR mutations of kinase domains was analyzed by genotyping analysis and sequences, and already reported. EGFR increased copy number was defined as Cappuzzo et al. criteria. FISH positive was found from 36/109 (33.0%) lung cancer patients, including 30 high polysomy cases and 6 gene amplification cases. FISH-positive cases were significantly correlated with worse prognosis (log-rank test p=0.0097). Within EGFR-mutant patients (n=55), FISH-positive cases were also correlated with poor prognosis (p=0.0255). FISH-negative tumors were found to be more frequently well-differentiated histology. Smoking status (never smoker vs. smoker, p=0.1510), and gender (p=0.5248) did not correlated with FISH positive. EGFR IHC results were correlated with FISH results (p=0.004), but not correlated with prognosis (p=0.2815). Although EGFR FISH-positive rate did not correlated with EGFR mutation (p=0.1973), EGFR polysomy or amplification cases were correlated with EGFR mutations (p=0.0023). In conclusion, the EGFR FISH-positive rate in Japanese patients with NSCLC was similar to rates in Western populations, unlike the higher frequencies of EGFR mutation in East Asians. A high EGFR gene copy number might have shorter survival in NSCLC.

Homozygosity for a novel missense mutation in the leptin receptor gene (P316T) in two Egyptian cousins with severe early onset obesity.

PubMed

Mazen, I; El-Gammal, M; Abdel-Hamid, M; Farooqi, I S; Amr, K

2011-04-01

Congenital deficiency of the leptin receptor is a very rare cause of severe early-onset obesity. To date, only 9 families have been reported in the literature to have mutations in the leptin receptor gene. The clinical features include severe early onset obesity, severe hyperphagia, hypogonadotropic hypogonadism, and T cell and neuroendocrine/metabolic dysfunction. Here we report two cousins with severe early onset obesity and recurrent respiratory tract infections. Their serum leptin levels were elevated but they were within the range predicted by the elevated fat mass in both cousins. Direct sequencing of the entire coding sequence of the leptin receptor gene revealed a novel homozygous missense mutation in exon 6, P316T. The mutation was found in the homozygous form in both cousins and in the heterozygote state in their parents. This mutation was not found in 200 chromosomes from 100 unrelated normal weight control subjects of Egyptian origin using PCR-RFLP analysis. In conclusion, finding this new mutation in the LEPR beside our previous mutation in the LEP gene implies that monogenic obesity syndromes may be common in the Egyptian population owing to the high rates of consanguineous marriages. Further screening of more families for mutations in LEP, LEPR, and MC4 might confirm this assumption. Copyright © 2010 Elsevier Inc. All rights reserved.

Predicting response to EGFR inhibitors in metastatic colorectal cancer: current practice and future directions.

PubMed

Shankaran, Veena; Obel, Jennifer; Benson, Al B

2010-01-01

The identification of KRAS mutational status as a predictive marker of response to antibodies against the epidermal growth factor receptor (EGFR) has been one of the most significant and practice-changing recent advances in colorectal cancer research. Recently, data suggesting a potential role for other markers (including BRAF mutations, loss of phosphatase and tension homologue deleted on chromosome ten expression, and phosphatidylinositol-3-kinase-AKT pathway mutations) in predicting response to anti-EGFR therapy have emerged. Ongoing clinical trials and correlative analyses are essential to definitively identify predictive markers and develop therapeutic strategies for patients who may not derive benefit from anti-EGFR therapy. This article reviews recent clinical trials supporting the predictive role of KRAS, recent changes to clinical guidelines and pharmaceutical labeling, investigational predictive molecular markers, and newer clinical trials targeting patients with mutated KRAS.

Enhancement of B-cell receptor signaling by a point mutation of adaptor protein 3BP2 identified in human inherited disease cherubism.

PubMed

Ogi, Kazuhiro; Nakashima, Kenji; Chihara, Kazuyasu; Takeuchi, Kenji; Horiguchi, Tomoko; Fujieda, Shigeharu; Sada, Kiyonao

2011-09-01

Tyrosine phosphorylation of adaptor protein c-Abl-Src homology 3 (SH3) domain-binding protein-2 (3BP2, also referred to SH3BP2) positively regulates the B-cell antigen receptor (BCR)-mediated signal transduction, leading to the activation of nuclear factor of activated T cells (NFAT). Here we showed the effect of the proline to arginine substitution of 3BP2 in which is the most common mutation in patients with cherubism (P418R) on B-cell receptor signaling. Comparing to the wild type, overexpression of the mutant form of 3BP2 (3BP2-P416R, corresponding to P418R in human protein) enhanced BCR-mediated activation of NFAT. 3BP2-P416R increased the signaling complex formation with Syk, phospholipase C-γ2 (PLC-γ2), and Vav1. In contrast, 3BP2-P416R could not change the association with the negative regulator 14-3-3. Loss of the association mutant that was incapable to associate with 14-3-3 could not mimic BCR-mediated NFAT activation in Syk-deficient cells. Moreover, BCR-mediated phosphorylation of extracellular signal regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) was not affected by P416R mutation. These results showed that P416R mutation of 3BP2 causes the gain of function in B cells by increasing the interaction with specific signaling molecules. © 2011 The Authors. Journal compilation © 2011 by the Molecular Biology Society of Japan/Blackwell Publishing Ltd.

Exploratory cohort study and meta-analysis of BIM deletion polymorphism in patients with epidermal growth factor receptor-mutant non-small-cell lung cancer treated with epidermal growth factor receptor tyrosine kinase inhibitors

PubMed Central

Sun, Si; Yu, Hui; Wang, Huijie; Zhao, Xinmin; Zhao, Xintai; Wu, Xianghua; Qiao, Jie; Chang, Jianhua; Wang, Jialei

2017-01-01

Background Non-small-cell lung cancer (NSCLC) patients with epidermal growth factor receptor (EGFR) mutations might develop primary and secondary resistance to tyrosine kinase inhibitors (TKIs). The proapoptotic protein Bcl-2-like 11 (BIM) is a key modulator of apoptosis triggered by EGFR-TKIs. The recent studies have indicated that some patients with positive EGFR mutations were refractory to EGFR-TKIs if they harbored a BIM deletion polymorphism. The purpose of this study was to investigate whether BIM polymorphism predicts treatment efficacy of EGFR-TKIs in Chinese NSCLC patients. Patients and methods A cohort of advanced NSCLC patients with EGFR mutations and treated with EGFR-TKIs (gefitinib or erlotinib) were recruited. We drew peripheral blood to determinate BIM deletion status and then compared patients’ clinical outcomes according to the BIM deletion status. Additionally, we electronically searched eligible cohort studies and conducted a meta-analysis to pool event risk. Results The exploratory cohort study included 140 patients. Patients with and without the BIM deletion polymorphism had similar objective response rates (ORRs, 48.5 vs 63.0%, P=0.16), disease control rate (DCR, 93.9 vs 97.0%, P=0.60) and adverse reactions. Similar progression-free survival (PFS) and overall survival (OS) were noted in overall population (P=0.27 for PFS and P=0.61 for OS) and prespecified patient subgroups. The meta-analysis included 10 eligible cohort studies involving 1,317 NSCLC patients. It showed the positive BIM deletion was associated with shorter PFS (hazard ratio =1.45; P=0.02). Nonsignificant differences existed for ORR, DCR and OS. Conclusion The expanded meta-analysis results demonstrated the positive BIM deletion predicts shorter PFS in NSCLC patients after treatment with EGFR-TKIs while other clinical measures do not. A large multicenter well-designed cohort study involving other concurrent genetic alterations is warranted. PMID:28435285

Exploratory cohort study and meta-analysis of BIM deletion polymorphism in patients with epidermal growth factor receptor-mutant non-small-cell lung cancer treated with epidermal growth factor receptor tyrosine kinase inhibitors.

PubMed

Sun, Si; Yu, Hui; Wang, Huijie; Zhao, Xinmin; Zhao, Xintai; Wu, Xianghua; Qiao, Jie; Chang, Jianhua; Wang, Jialei

2017-01-01

Non-small-cell lung cancer (NSCLC) patients with epidermal growth factor receptor ( EGFR ) mutations might develop primary and secondary resistance to tyrosine kinase inhibitors (TKIs). The proapoptotic protein Bcl-2-like 11 (BIM) is a key modulator of apoptosis triggered by EGFR-TKIs. The recent studies have indicated that some patients with positive EGFR mutations were refractory to EGFR-TKIs if they harbored a BIM deletion polymorphism. The purpose of this study was to investigate whether BIM polymorphism predicts treatment efficacy of EGFR-TKIs in Chinese NSCLC patients. A cohort of advanced NSCLC patients with EGFR mutations and treated with EGFR-TKIs (gefitinib or erlotinib) were recruited. We drew peripheral blood to determinate BIM deletion status and then compared patients' clinical outcomes according to the BIM deletion status. Additionally, we electronically searched eligible cohort studies and conducted a meta-analysis to pool event risk. The exploratory cohort study included 140 patients. Patients with and without the BIM deletion polymorphism had similar objective response rates (ORRs, 48.5 vs 63.0%, P =0.16), disease control rate (DCR, 93.9 vs 97.0%, P =0.60) and adverse reactions. Similar progression-free survival (PFS) and overall survival (OS) were noted in overall population ( P =0.27 for PFS and P =0.61 for OS) and prespecified patient subgroups. The meta-analysis included 10 eligible cohort studies involving 1,317 NSCLC patients. It showed the positive BIM deletion was associated with shorter PFS (hazard ratio =1.45; P =0.02). Nonsignificant differences existed for ORR, DCR and OS. The expanded meta-analysis results demonstrated the positive BIM deletion predicts shorter PFS in NSCLC patients after treatment with EGFR-TKIs while other clinical measures do not. A large multicenter well-designed cohort study involving other concurrent genetic alterations is warranted.

A role for the epidermal growth factor receptor signaling in development of intestinal serrated polyps in mice and humans.

PubMed

Bongers, Gerold; Muniz, Luciana R; Pacer, Michelle E; Iuga, Alina C; Thirunarayanan, Nanthakumar; Slinger, Erik; Smit, Martine J; Reddy, E Premkumar; Mayer, Lloyd; Furtado, Glaucia C; Harpaz, Noam; Lira, Sergio A

2012-09-01

Epithelial cancers can be initiated by activating mutations in components of the mitogen-activated protein kinase signaling pathway such as v-raf murine sarcoma viral oncogene homolog B1 (BRAF), v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS), or epidermal growth factor receptor (EGFR). Human intestinal serrated polyps are a heterogeneous group of benign lesions, but some progress to colorectal cancer. Tumors that arise from these polyps frequently contain activating mutations in BRAF or KRAS, but little is known about the role of EGFR activation in their development. Polyp samples were obtained from adults during screening colonoscopies at Mount Sinai Hospital in New York. We measured levels of EGFR protein and phosphorylation in human serrated polyps by immunohistochemical and immunoblot analyses. We generated transgenic mice that express the ligand for EGFR, Heparin-binding EGF-like growth factor (HB-EGF), in the intestine. EGFR and the extracellular-regulated kinases (ERK)1/2 were phosphorylated in serrated areas of human hyperplastic polyps (HPPs), sessile serrated adenomas, and traditional serrated adenomas. EGFR and ERK1/2 were phosphorylated in the absence of KRAS or BRAF activating mutations in a subset of HPP. Transgenic expression of the EGFR ligand HB-EGF in the intestines of mice promoted development of small cecal serrated polyps. Mice that expressed a combination of HB-EGF and US28 (a constitutively active, G-protein-coupled receptor that increases processing of HB-EGF from the membrane) rapidly developed large cecal serrated polyps. These polyps were similar to HPPs and had increased phosphorylation of EGFR and ERK1/2 within the serrated epithelium. Administration of pharmacologic inhibitors of EGFR or MAPK to these transgenic mice significantly reduced polyp development. Activation of EGFR signaling in the intestine of mice promotes development of serrated polyps. EGFR signaling also is activated in human HPPs, sessile serrated adenomas, and traditional serrated adenomas. Copyright © 2012 AGA Institute. Published by Elsevier Inc. All rights reserved.

An Alzheimer Disease-linked Rare Mutation Potentiates Netrin Receptor Uncoordinated-5C-induced Signaling That Merges with Amyloid β Precursor Protein Signaling.

PubMed

Hashimoto, Yuichi; Toyama, Yuka; Kusakari, Shinya; Nawa, Mikiro; Matsuoka, Masaaki

2016-06-03

A missense mutation (T835M) in the uncoordinated-5C (UNC5C) netrin receptor gene increases the risk of late-onset Alzheimer disease (AD) and also the vulnerability of neurons harboring the mutation to various insults. The molecular mechanisms underlying T835M-UNC5C-induced death remain to be elucidated. In this study, we show that overexpression of wild-type UNC5C causes low-grade death, which is intensified by an AD-linked mutation T835M. An AD-linked survival factor, calmodulin-like skin protein (CLSP), and a natural ligand of UNC5C, netrin1, inhibit this death. T835M-UNC5C-induced neuronal cell death is mediated by an intracellular death-signaling cascade, consisting of death-associated protein kinase 1/protein kinase D/apoptosis signal-regulating kinase 1 (ASK1)/JNK/NADPH oxidase/caspases, which merges at ASK1 with a death-signaling cascade, mediated by amyloid β precursor protein (APP). Notably, netrin1 also binds to APP and partially inhibits the death-signaling cascade, induced by APP. These results may provide new insight into the amyloid β-independent pathomechanism of AD. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Mutation and deletion analysis of GFRα-1, encoding the co-receptor for the GDNF/RET complex, in human brain tumours

PubMed Central

Gimm, O; Gössling, A; Marsh, D J; Dahia, P L M; Mulligan, L M; Deimling, A von; Eng, C

1999-01-01

Glial cell line-derived neurotrophic factor (GDNF) plays a key role in the control of vertebrate neuron survival and differentiation in both the central and peripheral nervous systems. GDNF preferentially binds to GFRα-1 which then interacts with the receptor tyrosine kinase RET. We investigated a panel of 36 independent cases of mainly advanced sporadic brain tumours for the presence of mutations in GDNF and GFRα-1. No mutations were found in the coding region of GDNF. We identified six previously described GFRα-1 polymorphisms, two of which lead to an amino acid change. In 15 of 36 brain tumours, all polymorphic variants appeared to be homozygous. Of these 15 tumours, one also had a rare, apparently homozygous, sequence variant at codon 361. Because of the rarity of the combination of homozygous sequence variants, analysis for hemizygous deletion was pursued in the 15 samples and loss of heterozygosity was found in 11 tumours. Our data suggest that intragenic point mutations of GDNF or GFRα-1 are not a common aetiologic event in brain tumours. However, either deletion of GFRα-1 and/or nearby genes may contribute to the pathogenesis of these tumours. © 1999 Cancer Research Campaign PMID:10408842

An Immunohistochemical Study of Anaplastic Lymphoma Kinase and Epidermal Growth Factor Receptor Mutation in Non-Small Cell Lung Carcinoma.

PubMed

Verma, Sonal; Kumar, Madhu; Kumari, Malti; Mehrotra, Raj; Kushwaha, R A S; Goel, Madhumati; Kumar, Ashutosh; Kant, Surya

2017-07-01

Lung cancer is one of the leading causes of cancer related death. Targeted treatment for specific markers may help in reducing the cancer related morbidity and mortality. To study expression of Anaplastic Lymphoma Kinase (ALK)and Epidermal Growth Factor Receptor (EGFR) mutations in patients of Non-Small Cell Lung Cancer NSCLC, that are the targets for specific ALK inhibitors and EGFR tyrosine kinase inhibitors. Total 69 cases of histologically diagnosed NSCLC were examined retrospectively for immunohistochemical expression of EGFR and ALK, along with positive control of normal placental tissue and anaplastic large cell lymphoma respectively. Of the NSCLC, Squamous Cell Carcinoma (SCC) accounted for 71.0% and adenocarcinoma was 26.1%. ALK expression was seen in single case of 60-year-old female, non-smoker with adenocarcinoma histology. EGFR expression was seen in both SCC (59.18%) and adenocarcinoma in (77.78%) accounting for 63.77% of all cases. Both ALK and EGFR mutation were mutually exclusive. EGFR expression was seen in 63.77% of cases, highlighting the importance of its use in routine analysis, for targeted therapy and better treatment results. Although, ALK expression was seen in 1.45% of all cases, it is an important biomarker in targeted cancer therapy. Also, the mutually exclusive expression of these two markers need further studies to develop a diagnostic algorithm for NSCLC patients.

Successful erlotinib rechallenge for leptomeningeal metastases of lung adenocarcinoma after erlotinib-induced interstitial lung disease: a case report and review of the literature.

PubMed

Togashi, Yosuke; Masago, Katsuhiro; Hamatani, Yasuhiro; Sakamori, Yuichi; Nagai, Hiroki; Kim, Young Hak; Mishima, Michiaki

2012-08-01

The most serious adverse reaction associated with treatment with epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) is drug-induced interstitial lung disease (ILD). Because EGFR-TKIs are key drugs for patients with non-small cell lung cancer who have somatic activating mutations of the epidermal growth factor receptor gene (EGFR mutations), several cases of retreatment with EGFR-TKIs after ILD induced by these drugs have been reported. Here, we present a 68-year-old man with lung adenocarcinoma and leptomeningeal metastases having an EGFR mutation who was retreated with erlotinib after erlotinib-induced ILD. He suffered no ILD recurrence and his leptomeningeal metastases dramatically improved. In addition to the present case, reports of nine patients who were retreated with EGFR-TKIs after ILD were found in the literature. Only one patient had recurrence of ILD (although seven were retreated at a reduced dose of EGFR-TKIs, including the patient with recurrence). In contrast, three patients had no recurrence of ILD even without dose-reduction. These reports suggest that dose-reduction plays a limited role in preventing recurrence. Many patients received corticosteroids during retreatment, but not the one with recurrence of ILD. This may suggest that corticosteroids can prevent recurrence due to their antiinflammatory properties. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Fibroblast growth factor receptors: multifactorial-contributors to tumor initiation and progression.

PubMed

Feng, Shachuan; Zhou, Li; Nice, Edouard Collins; Huang, Canhua

2015-01-01

Fibroblast growth factor receptors (FGFRs), encoded by four genes (FGFR1, FGFR2, FGFR3, and FGFR4) are tightly associated with many biological processes such as organ development, cell proliferation and migration. Studies over the past decades have validated the pivotal roles FGFRs play in tumorigenesis due to the regulation of diverse tumorigenesis-related processes, including cell survival, proliferation, inflammation, metastasis and angiogenesis. Interestingly, FGFR mutations in somatic cells leading to tumorigenesis and those in germ cells leading to developmental disorders are identical, suggesting that FGFR mutations result in different diseases due to their spatio-temporal expression. Thus, discoveries in developmental biology may also be applicable to cancer. FGFRs regulate the expression and/or the activity of a myriad of molecules (e.g. matrix metalloproteinases (MMPs) and Snail) that are tightly linked to tumorigenesis by four main signaling pathways (RAS-MAPK, PI3K-AKT, PLCγ-PIP2, and STAT), as well as other minor branches. Epigenetic and genetic alteration of FGFR genes, including DNA methylation, histone remodeling, microRNA regulation, single nucleotide polymorphisms (SNPs), gene missense mutations, amplification, and fusion of FGFRs with other genes, which result in gain or loss of FGFR function, have been identified in many types of cancer. In this review, we focus in particular on recent advances in the relationship between FGFR disorders and tumorigenesis.

Evaluation of a Cys23Ser mutation within the human 5-HT2C receptor gene: no evidence for an association of the mutant allele with obesity or underweight in children, adolescents and young adults.

PubMed

Lentes, K U; Hinney, A; Ziegler, A; Rosenkranz, K; Wurmser, H; Barth, N; Jacob, K; Coners, H; Mayer, H; Grzeschik, K H; Schäfer, H; Remschmidt, H; Pirke, K M; Hebebrand, J

1997-01-01

Serotonin is a neurotransmitter involved in a large number of psychophysiological processes including the regulation of mood, arousal, aggression, sleep, learning, nociceptions, nerve growth and importantly, appetitive functions. Alterations of 5-HT receptor activity have been shown to occur in many psychiatric diseases including depression, anxiety, eating disorders, schizophrenia etc. Hence, genetic variation in genes coding for serotonin receptor proteins might well be involved in the genetic predisposition to these diseases and therefore are of great pharmacogenetic relevance. Knockout mice deficient of a functional 5-HT2C receptor have implicated a potential role of this receptor subtype in the serotonergic control of appetite. A Cys23Ser mutation in the human 5-HT2C receptor gene discovered recently prompted us to investigate this mutation with regard to the development of human obesity. We have evaluated this mutation in 241 obese children and adolescents (mean BMI > or = 97th percentile), 80 normal weight children (BMI 5th-85th percentile) and 92 underweight probands (BMI < or = 15th percentile) for a possible association with obesity. The frequencies of the mutant allele in all three weight groups (obese subjects: 0.1597; normal weight: 0.168; underweight: 0.1575) were very similar. Association as well as linkage studies were negative. Therefore it is unlikely that this receptor mutation plays a direct role in the development of human obesity.

Complete remission of liver metastasis in a lung cancer patient with epidermal growth factor mutation achieved with Icotinib

PubMed Central

Zhu, Zhouyu

2016-01-01

A 65‐year‐old Chinese male was referred to our hospital for epidermal growth factor receptor (EGFR)‐mutated advanced non‐small cell lung cancer (NSCLC). Aggressive combined therapy with surgical resection of the right upper lung lesion and chemotherapy was performed. One month later, continued Icotinib treatment was used as magnetic resonance imaging revealed liver metastasis (LM). Interestingly, complete remission of the patient's LM lesions was achieved in six months. To our knowledge, this is the first report documenting a successful case of an NSCLC patient with LM treated with Icotinib after receiving a radical resection for pulmonary carcinoma. Our experience could provide a treatment strategy for patients with similar disease. PMID:27807951

Multiple Functions of Let-23, a Caenorhabditis Elegans Receptor Tyrosine Kinase Gene Required for Vulval Induction

PubMed Central

Aroian, R. V.; Sternberg, P. W.

1991-01-01

The let-23 gene, which encodes a putative tyrosine kinase of the epidermal growth factor (EGF) receptor subfamily, has multiple functions during Caenorhabditis elegans development. We show that let-23 function is required for vulval precursor cells (VPCs) to respond to the signal that induces vulval differentiation: a complete loss of let-23 function results in no induction. However, some let-23 mutations that genetically reduce but do not eliminate let-23 function result in VPCs apparently hypersensitive to inductive signal: as many as five of six VPCs can adopt vulval fates, in contrast to the three that normally do. These results suggest that the let-23 receptor tyrosine kinase controls two opposing pathways, one that stimulates vulval differentiation and another that negatively regulates vulval differentiation. Furthermore, analysis of 16 new let-23 mutations indicates that the let-23 kinase functions in at least five tissues. Since various let-23 mutant phenotypes can be obtained independently, the let-23 gene is likely to have tissue-specific functions. PMID:2071015

Cisplatin With or Without Veliparib in Treating Patients With Recurrent or Metastatic Triple-Negative and/or BRCA Mutation-Associated Breast Cancer With or Without Brain Metastases

ClinicalTrials.gov

2018-06-26

Breast Carcinoma Metastatic in the Brain; Deleterious BRCA1 Gene Mutation; Deleterious BRCA2 Gene Mutation; Estrogen Receptor Negative; HER2/Neu Negative; Progesterone Receptor Negative; Recurrent Breast Carcinoma; Stage IV Breast Cancer AJCC v6 and v7; Triple-Negative Breast Carcinoma

Deep Sequencing-guided Design of a High Affinity Dual Specificity Antibody to Target Two Angiogenic Factors in Neovascular Age-related Macular Degeneration* ♦

PubMed Central

Koenig, Patrick; Lee, Chingwei V.; Sanowar, Sarah; Wu, Ping; Stinson, Jeremy; Harris, Seth F.; Fuh, Germaine

2015-01-01

The development of dual targeting antibodies promises therapies with improved efficacy over mono-specific antibodies. Here, we engineered a Two-in-One VEGF/angiopoietin 2 antibody with dual action Fab (DAF) as a potential therapeutic for neovascular age-related macular degeneration. Crystal structures of the VEGF/angiopoietin 2 DAF in complex with its two antigens showed highly overlapping binding sites. To achieve sufficient affinity of the DAF to block both angiogenic factors, we turned to deep mutational scanning in the complementarity determining regions (CDRs). By mutating all three CDRs of each antibody chain simultaneously, we were able not only to identify affinity improving single mutations but also mutation pairs from different CDRs that synergistically improve both binding functions. Furthermore, insights into the cooperativity between mutations allowed us to identify fold-stabilizing mutations in the CDRs. The data obtained from deep mutational scanning reveal that the majority of the 52 CDR residues are utilized differently for the two antigen binding function and permit, for the first time, the engineering of several DAF variants with sub-nanomolar affinity against two structurally unrelated antigens. The improved variants show similar blocking activity of receptor binding as the high affinity mono-specific antibodies against these two proteins, demonstrating the feasibility of generating a dual specificity binding surface with comparable properties to individual high affinity mono-specific antibodies. PMID:26088137

Receptor tyrosine kinase mutations in developmental syndromes and cancer: two sides of the same coin

PubMed Central

McDonell, Laura M.; Kernohan, Kristin D.; Boycott, Kym M.; Sawyer, Sarah L.

2015-01-01

Receptor tyrosine kinases (RTKs) are a family of ligand-binding cell surface receptors that regulate a wide range of essential cellular activities, including proliferation, differentiation, cell-cycle progression, survival and apoptosis. As such, these proteins play an important role during development and throughout life; germline mutations in genes encoding RTKs cause several developmental syndromes, while somatic alterations contribute to the pathogenesis of many aggressive cancers. This creates an interesting paradigm in which mutation timing, type and location in a gene leads to different cell signaling and biological responses, and ultimately phenotypic outcomes. In this review, we highlight the roles of RTKs in developmental disorders and cancer. The multifaceted roles of these receptors, their genetic signatures and their signaling during developmental morphogenesis and oncogenesis are discussed. Additionally, we propose that comparative analysis of RTK mutations responsible for developmental syndromes may shed light on those driving tumorigenesis. PMID:26152202

Achondroplasia: Development, Pathogenesis, and Therapy

PubMed Central

Ornitz, David M.; Legeai-Mallet, Laurence

2016-01-01

Autosomal dominant mutations in Fibroblast Growth Factor Receptor 3 (FGFR3) cause Achondroplasia (Ach), the most common form of dwarfism in humans, and related chondrodysplasia syndromes that include Hypochondroplasia (Hch), Severe Achondroplasia with Developmental Delay and Acanthosis Nigricans (SADDAN), and Thanatophoric dysplasia (TD). FGFR3 is expressed in chondrocytes and mature osteoblasts where it functions to regulate bone growth. Analysis of the mutations in FGFR3 revealed increased signaling through a combination of mechanisms that include stabilization of the receptor, enhanced dimerization, and enhanced tyrosine kinase activity. Paradoxically, increased FGFR3 signaling profoundly suppresses proliferation and maturation of growth plate chondrocytes resulting in decreased growth plate size, reduced trabecular bone volume, and resulting decreased bone elongation. In this review we discuss the molecular mechanisms that regulate growth plate chondrocytes, the pathogenesis of Ach, and therapeutic approaches that are being evaluated to improve endochondral bone growth in people with Ach and related conditions. PMID:27987249

Troyer Syndrome Protein Spartin Is Mono-Ubiquitinated and Functions in EGF Receptor Trafficking

PubMed Central

Jupille, Henri; Fatheddin, Parvin; Puertollano, Rosa

2007-01-01

Troyer syndrome is an autosomal recessive hereditary spastic paraplegia caused by mutation in the spartin (SPG20) gene, which encodes a widely expressed protein of unknown function. This mutation results in premature protein truncation and thus might signify a loss-of-function disease mechanism. In this study, we have found that spartin is mono-ubiquitinated and functions in degradation of the epidermal growth factor receptor (EGFR). Upon EGF stimulation, spartin translocates from the cytoplasm to the plasma membrane and colocalizes with internalized EGF-Alexa. Knockdown of spartin by small interfering RNA decreases the rate of EGFR degradation and also affects EGFR internalization, recycling, or both. Furthermore, overexpression of spartin results in a prominent decrease in EGFR degradation. Taken together, our data suggest that spartin is involved in the intracellular trafficking of EGFR and that impaired endocytosis may underlie the pathogenesis of Troyer syndrome. PMID:17332501

Molecular Mechanisms of Fibroblast Growth Factor Signaling in Physiology and Pathology

PubMed Central

Belov, Artur A.; Mohammadi, Moosa

2013-01-01

Fibroblast growth factors (FGFs) signal in a paracrine or endocrine fashion to mediate a myriad of biological activities, ranging from issuing developmental cues, maintaining tissue homeostasis, and regulating metabolic processes. FGFs carry out their diverse functions by binding and dimerizing FGF receptors (FGFRs) in a heparan sulfate (HS) cofactor- or Klotho coreceptor-assisted manner. The accumulated wealth of structural and biophysical data in the past decade has transformed our understanding of the mechanism of FGF signaling in human health and development, and has provided novel concepts in receptor tyrosine kinase (RTK) signaling. Among these contributions are the elucidation of HS-assisted receptor dimerization, delineation of the molecular determinants of ligand–receptor specificity, tyrosine kinase regulation, receptor cis-autoinhibition, and tyrosine trans-autophosphorylation. These structural studies have also revealed how disease-associated mutations highjack the physiological mechanisms of FGFR regulation to contribute to human diseases. In this paper, we will discuss the structurally and biophysically derived mechanisms of FGF signaling, and how the insights gained may guide the development of therapies for treatment of a diverse array of human diseases. PMID:23732477

Molecular mechanisms of fibroblast growth factor signaling in physiology and pathology.

PubMed

Belov, Artur A; Mohammadi, Moosa

2013-06-01

Fibroblast growth factors (FGFs) signal in a paracrine or endocrine fashion to mediate a myriad of biological activities, ranging from issuing developmental cues, maintaining tissue homeostasis, and regulating metabolic processes. FGFs carry out their diverse functions by binding and dimerizing FGF receptors (FGFRs) in a heparan sulfate (HS) cofactor- or Klotho coreceptor-assisted manner. The accumulated wealth of structural and biophysical data in the past decade has transformed our understanding of the mechanism of FGF signaling in human health and development, and has provided novel concepts in receptor tyrosine kinase (RTK) signaling. Among these contributions are the elucidation of HS-assisted receptor dimerization, delineation of the molecular determinants of ligand-receptor specificity, tyrosine kinase regulation, receptor cis-autoinhibition, and tyrosine trans-autophosphorylation. These structural studies have also revealed how disease-associated mutations highjack the physiological mechanisms of FGFR regulation to contribute to human diseases. In this paper, we will discuss the structurally and biophysically derived mechanisms of FGF signaling, and how the insights gained may guide the development of therapies for treatment of a diverse array of human diseases.

Donohue syndrome and use of continuous subcutaneous insulin pump therapy.

PubMed

Huggard, Dean; Stack, Tom; Satas, Saulius; Gorman, Clodagh O

2015-10-27

Donohue syndrome is a rare autosomal recessive condition caused by severe loss-of-function mutations in the insulin receptor (INSR) gene. The diagnosis is made on clinical, biochemical and genetic grounds. Mutations are found on chromosome 19p13.2, and code for mutations in the INSR gene. Treatment is challenging and often unsuccessful, and relies on maintaining normoglycaemia and avoiding fasting; in some patients, recombinant human insulin-like growth factor (rhIGF-1) has been trialled. The prognosis is poor, with most babies dying in infancy. Ethically, it is important to consider the benefit versus burden of treatment, the quality of life of the surviving patient and the parents' wishes, when making decisions regarding withholding or withdrawing care. 2015 BMJ Publishing Group Ltd.

Personalized medicine in non-small-cell lung cancer: is KRAS a useful marker in selecting patients for epidermal growth factor receptor-targeted therapy?

PubMed

Roberts, Patrick J; Stinchcombe, Thomas E; Der, Channing J; Socinski, Mark A

2010-11-01

In patients with metastatic colorectal cancer, the predictive value of KRAS mutational status in the selection of patients for treatment with anti-epidermal growth factor (EGFR) monoclonal antibodies is established. In patients with non-small-cell lung cancer (NSCLC), the utility of determining KRAS mutational status to predict clinical benefit to anti-EGFR therapies remains unclear. This review will provide a brief description of Ras biology, provide an overview of aberrant Ras signaling in NSCLC, and summarize the clinical data for using KRAS mutational status as a negative predictive biomarker to anti-EGFR therapies. Retrospective investigations of KRAS mutational status as a negative predictor of clinical benefit from anti-EGFR therapies in NSCLC have been performed; however, small samples sizes as a result of low prevalence of KRAS mutations and the low rate of tumor sample collection have limited the strength of these analyses. Although an association between the presence of KRAS mutation and lack of response to EGFR tyrosine kinase inhibitors (TKIs) has been observed, it remains unclear whether there is an association between KRAS mutation and EGFR TKI progression-free and overall survival. Unlike colorectal cancer, KRAS mutations do not seem to identify patients who do not benefit from anti-EGFR monoclonal antibodies in NSCLC. The future value of testing for KRAS mutational status may be to exclude the possibility of an EGFR mutation or anaplastic lymphoma kinase translocation or to identify a molecular subset of patients with NSCLC in whom to pursue a drug development strategy that targets the KRAS pathway.

Enhanced Human-Type Receptor Binding by Ferret-Transmissible H5N1 with a K193T Mutation.

PubMed

Peng, Wenjie; Bouwman, Kim M; McBride, Ryan; Grant, Oliver C; Woods, Robert J; Verheije, Monique H; Paulson, James C; de Vries, Robert P

2018-05-15

All human influenza pandemics have originated from avian influenza viruses. Although multiple changes are needed for an avian virus to be able to transmit between humans, binding to human-type receptors is essential. Several research groups have reported mutations in H5N1 viruses that exhibit specificity for human-type receptors and promote respiratory droplet transmission between ferrets. Upon detailed analysis, we have found that these mutants exhibit significant differences in fine receptor specificity compared to human H1N1 and H3N2 and retain avian-type receptor binding. We have recently shown that human influenza viruses preferentially bind to α2-6-sialylated branched N-linked glycans, where the sialic acids on each branch can bind to receptor sites on two protomers of the same hemagglutinin (HA) trimer. In this binding mode, the glycan projects over the 190 helix at the top of the receptor-binding pocket, which in H5N1 would create a stearic clash with lysine at position 193. Thus, we hypothesized that a K193T mutation would improve binding to branched N-linked receptors. Indeed, the addition of the K193T mutation to the H5 HA of a respiratory-droplet-transmissible virus dramatically improves both binding to human trachea epithelial cells and specificity for extended α2-6-sialylated N-linked glycans recognized by human influenza viruses. IMPORTANCE Infections by avian H5N1 viruses are associated with a high mortality rate in several species, including humans. Fortunately, H5N1 viruses do not transmit between humans because they do not bind to human-type receptors. In 2012, three seminal papers have shown how these viruses can be engineered to transmit between ferrets, the human model for influenza virus infection. Receptor binding, among others, was changed, and the viruses now bind to human-type receptors. Receptor specificity was still markedly different compared to that of human influenza viruses. Here we report an additional mutation in ferret-transmissible H5N1 that increases human-type receptor binding. K193T seems to be a common receptor specificity determinant, as it increases human-type receptor binding in multiple subtypes. The K193T mutation can now be used as a marker during surveillance of emerging viruses to assess potential pandemic risk. Copyright © 2018 American Society for Microbiology.

Two novel mutations in the sixth transmembrane segment of the thyrotropin receptor gene causing hyperfunctioning thyroid nodules.

PubMed

Gozu, Hulya; Avsar, Melike; Bircan, Rifat; Claus, Maren; Sahin, Serap; Sezgin, Ozlem; Deyneli, Oguzhan; Paschke, Ralf; Cirakoglu, Beyazit; Akalin, Sema

2005-04-01

Autonomously functioning thyroid nodules (AFTNs) can present as hyperfunctioning adenomas or toxic multinodular goiters. In the last decade, a large number of activating mutations have been identified in the thyrotropin receptor (TSHR) gene in autonomously functioning thyroid nodules. Most have been situated close to, or within the sixth transmembrane segment and third intracellular loop of the TSHR where the receptor interacts with the Gs protein. In this study we describe two novel mutations in the sixth transmembrane segment of the TSHR causing hyperfunctioning thyroid nodules. Genomic DNAs were isolated from four hyperfunctioning thyroid nodules, normal tissues and peripheral leukocytes of two patients with toxic multinodular goiter. After amplifying the related regions, TSHR and G(s)alpha genes were analyzed by single-strand conformation polymorphism (SSCP) analysis. The precise localization of the mutations was identified by automatic DNA sequence analysis. Functional studies were done by site-directed mutagenesis and transfection of a mutant construct into COS-7 cells. We identified two novel TSHR mutations in two hyperfunctioning thyroid nodules: Phe631Val in the first patient and Iso630Met in the second patient. Both mutant receptors display an increase in constitutive stimulation of basal cyclic adenosine monophosphate (cAMP) levels compared to the wild-type receptor. This confirms that these mutant receptors cause hyperfunctioning thyroid nodules.

Radiological Features of Brain Metastases from Non-small Cell Lung Cancer Harboring EGFR Mutation.

PubMed

Takamori, Shinkichi; Toyokawa, Gouji; Shimokawa, Mototsugu; Kinoshita, Fumihiko; Kozuma, Yuka; Matsubara, Taichi; Haratake, Naoki; Akamine, Takaki; Mukae, Nobutaka; Hirai, Fumihiko; Tagawa, Tetsuzo; Oda, Yoshinao; Iwaki, Toru; Iihara, Koji; Honda, Hiroshi; Maehara, Yoshihiko

2018-06-01

To investigate the radiological features on computed tomography (CT) of brain metastasis (BM) from epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancer (NSCLC). Thirty-four patients with NSCLC with BMs who underwent surgical resection of the BMs at the Department of Neurosurgery, Kyushu University from 2005 to 2016 were enrolled in the study. The EGFR statuses of the 34 BMs were investigated. Radiological features, including the number, size, and location of the tumor, were delineated by CT. Patients with EGFR-mutated BMs had significantly higher frequencies of multiple metastases than those with the non-EGFR-mutated type (p=0.042). BMs harboring mutations in EGFR were more frequently observed in the central area of the brain compared to those without mutations in EGFR (p=0.037). Careful follow-up of patients with EGFR-mutated NSCLC may be necessary given the high frequencies of multiple BMs and their location in the central area of the brain. Copyright© 2018, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

The Frequency and Type of K-RAS Mutations in Mexican Patients With Colorectal Cancer: A National Study.

PubMed

Cárdenas-Ramos, Susana G; Alcázar-González, Gregorio; Reyes-Cortés, Luisa M; Torres-Grimaldo, Abdiel A; Calderón-Garcidueñas, Ana L; Morales-Casas, José; Flores-Sánchez, Patricia; De León-Escobedo, Raúl; Gómez-Díaz, Antonio; Moreno-Bringas, Carmen; Sánchez-Guillén, Jorge; Ramos-Salazar, Pedro; González-de León, César; Barrera-Saldaña, Hugo A

2017-06-01

Current metastatic colorectal cancer (mCRC) therapy uses monoclonal antibodies against the epidermal growth factor receptor. This treatment is only useful in the absence of K-RAS gene mutations; therefore the study of such mutations is part of a personalized treatment. The aim of this work is to determine the frequency and type of the most common K-RAS mutations in Mexican patients with metastatic disease by nucleotide sequencing. We studied 888 patients with mCRC from different regions of Mexico. The presence of mutations in exon 2, codons 12 and 13, of the K-RAS gene was determined by nucleotide sequencing. Patients exhibited K-RAS gene mutations in 35% (310/888) of cases. Mutation frequency of codons 12 and 13 was 71% (221/310) and 29% (89/310), respectively. The most common mutation (45.7%) in codon 12 was c.35G>A (p.G12D), whereas the one in codon 13 was c.38G>A (p.G13D) (78.7%). Given the frequency of K-RAS mutations in Mexicans, making a genetic study before deciding to treat mCRC patients with monoclonal antibodies is indispensable.

High throughput mutagenesis for identification of residues regulating human prostacyclin (hIP) receptor expression and function.

PubMed

Bill, Anke; Rosethorne, Elizabeth M; Kent, Toby C; Fawcett, Lindsay; Burchell, Lynn; van Diepen, Michiel T; Marelli, Anthony; Batalov, Sergey; Miraglia, Loren; Orth, Anthony P; Renaud, Nicole A; Charlton, Steven J; Gosling, Martin; Gaither, L Alex; Groot-Kormelink, Paul J

2014-01-01

The human prostacyclin receptor (hIP receptor) is a seven-transmembrane G protein-coupled receptor (GPCR) that plays a critical role in vascular smooth muscle relaxation and platelet aggregation. hIP receptor dysfunction has been implicated in numerous cardiovascular abnormalities, including myocardial infarction, hypertension, thrombosis and atherosclerosis. Genomic sequencing has discovered several genetic variations in the PTGIR gene coding for hIP receptor, however, its structure-function relationship has not been sufficiently explored. Here we set out to investigate the applicability of high throughput random mutagenesis to study the structure-function relationship of hIP receptor. While chemical mutagenesis was not suitable to generate a mutagenesis library with sufficient coverage, our data demonstrate error-prone PCR (epPCR) mediated mutagenesis as a valuable method for the unbiased screening of residues regulating hIP receptor function and expression. Here we describe the generation and functional characterization of an epPCR derived mutagenesis library compromising >4000 mutants of the hIP receptor. We introduce next generation sequencing as a useful tool to validate the quality of mutagenesis libraries by providing information about the coverage, mutation rate and mutational bias. We identified 18 mutants of the hIP receptor that were expressed at the cell surface, but demonstrated impaired receptor function. A total of 38 non-synonymous mutations were identified within the coding region of the hIP receptor, mapping to 36 distinct residues, including several mutations previously reported to affect the signaling of the hIP receptor. Thus, our data demonstrates epPCR mediated random mutagenesis as a valuable and practical method to study the structure-function relationship of GPCRs.

High Throughput Mutagenesis for Identification of Residues Regulating Human Prostacyclin (hIP) Receptor Expression and Function

PubMed Central

Kent, Toby C.; Fawcett, Lindsay; Burchell, Lynn; van Diepen, Michiel T.; Marelli, Anthony; Batalov, Sergey; Miraglia, Loren; Orth, Anthony P.; Renaud, Nicole A.; Charlton, Steven J.; Gosling, Martin; Gaither, L. Alex; Groot-Kormelink, Paul J.

2014-01-01

The human prostacyclin receptor (hIP receptor) is a seven-transmembrane G protein-coupled receptor (GPCR) that plays a critical role in vascular smooth muscle relaxation and platelet aggregation. hIP receptor dysfunction has been implicated in numerous cardiovascular abnormalities, including myocardial infarction, hypertension, thrombosis and atherosclerosis. Genomic sequencing has discovered several genetic variations in the PTGIR gene coding for hIP receptor, however, its structure-function relationship has not been sufficiently explored. Here we set out to investigate the applicability of high throughput random mutagenesis to study the structure-function relationship of hIP receptor. While chemical mutagenesis was not suitable to generate a mutagenesis library with sufficient coverage, our data demonstrate error-prone PCR (epPCR) mediated mutagenesis as a valuable method for the unbiased screening of residues regulating hIP receptor function and expression. Here we describe the generation and functional characterization of an epPCR derived mutagenesis library compromising >4000 mutants of the hIP receptor. We introduce next generation sequencing as a useful tool to validate the quality of mutagenesis libraries by providing information about the coverage, mutation rate and mutational bias. We identified 18 mutants of the hIP receptor that were expressed at the cell surface, but demonstrated impaired receptor function. A total of 38 non-synonymous mutations were identified within the coding region of the hIP receptor, mapping to 36 distinct residues, including several mutations previously reported to affect the signaling of the hIP receptor. Thus, our data demonstrates epPCR mediated random mutagenesis as a valuable and practical method to study the structure-function relationship of GPCRs. PMID:24886841

Aberrant status and clinicopathologic characteristic associations of 11 target genes in 1,321 Chinese patients with lung adenocarcinoma.

PubMed

Zhao, Mengnan; Zhan, Cheng; Li, Ming; Yang, Xiaodong; Yang, Xinyu; Zhang, Yong; Lin, Miao; Xia, Yifeng; Feng, Mingxiang; Wang, Qun

2018-01-01

The aberrant status of target genes and their associations with clinicopathologic characteristics are still unclear in primary lung adenocarcinoma. The common mutations and translocations of nine target genes were evaluated in 1,247 specimens of surgically-resected primary lung adenocarcinoma. Immunohistochemistry was used to analyze the expressions of programmed death-1 (PD-1)/programmed death-ligand 1 (PD-L1) in 731 specimens. The frequency of the aberrations and their associations with clinicopathologic characteristics were analyzed. Overall, 952 (76.3%) of 1,247 patients harbored at least one target mutation or translocation: epidermal growth factor receptor ( EGFR ) (729, 58.5%), v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog ( KRAS ) (83, 6.7%), human epidermal growth factor receptor 2 ( HER2 ) (82, 6.6%), anaplastic lymphoma kinase ( ALK) (23, 1.8%), phosphoinositide-3-kinase catalytic alpha polypeptide ( PIK3CA ) (20, 1.6%), Ret proto-oncogene RET (15, 1.2%), ROS proto-oncogene 1 receptor tyrosine kinase ( ROS1 ) (12, 1.0%), B-raf proto-oncogene ( BRAF ) (9, 0.7%), neuroblastoma RAS viral (v-ras) oncogene homolog ( NRAS ) (3, 0.2%). Fourteen (1.9%) of 731 patients were PD-1 positive and 95 (13.0%) were PD-L1 positive in tumor cells. In men and smokers, there were more frequent KRAS mutations (both P<0.001) and PD-L1 positive tumors (P<0.001, P=0.005, respectively), and less frequent EGFR mutations (P=0.049, <0.001, respectively). In ground-glass opacity (GGO) or ground-glass nodules (GGN), there were more HER2 (P=0.033) but less EGFR (P=0.025) and PIK3CA mutations (P=0.012), and ALK translocations (P=0.014). EGFR (P<0.001), KRAS mutations (P=0.004) and PD-L1 positive tumors (P=0.046) were more frequent in older patients, while HER2 (P<0.001), ALK (P=0.005) and ROS1 aberrations (P=0.044) were less frequent. Invasive mucinous adenocarcinoma was significantly associated with KRAS and ALK aberrations (both P<0.001), while solid predominant adenocarcinoma was associated with ROS1 translocations (P=0.036) and PD-L1 expression (P<0.001). KRAS, HER2, and ALK aberrations were scarce in patients with EGFR mutations (all P<0.001), while PD-L1 positive tumors positively correlated with ALK translocations (P=0.031) and negatively correlated with HER2 mutations (P=0.019). Most patients with primary lung adenocarcinoma harbored target gene aberrations. The frequency of each alteration differed in patients depending on clinicopathologic characteristics.

Loops D, E and G in the Drosophila Dα1 subunit contribute to high neonicotinoid sensitivity of Dα1-chicken β2 nicotinic acetylcholine receptor.

PubMed

Ihara, Makoto; Hikida, Mai; Matsushita, Hiroyuki; Yamanaka, Kyosuke; Kishimoto, Yuya; Kubo, Kazuki; Watanabe, Shun; Sakamoto, Mifumi; Matsui, Koutaro; Yamaguchi, Akihiro; Okuhara, Daiki; Furutani, Shogo; Sattelle, David B; Matsuda, Kazuhiko

2018-06-01

Neonicotinoid insecticides interact with the orthosteric site formed at subunit interfaces of insect nicotinic ACh (nACh) receptors. However, their interactions with the orthosteric sites at α-non α and α-α subunit interfaces remain poorly understood. The aim of this study was to elucidate the mechanism of neonicotinoid actions using the Drosophila Dα1-chicken β2 hybrid nACh receptor. Computer models of the (Dα1) 3 (β2) 2 nACh receptor in complex with imidacloprid and thiacloprid were generated. Amino acids in the Dα1 subunit were mutated to corresponding amino acids in the human α4 subunit to examine their effects on the agonist actions of neonicotinoids on (Dα1) 3 (β2) 2 and (Dα1) 2 (β2) 3 nACh receptors expressed in Xenopus laevis oocytes using voltage-clamp electrophysiology. The (Dα1) 3 (β2) 2 nACh receptor models indicated that amino acids in loops D, E and G probably determine the effects of neonicotinoids. The amino acid mutations tested had minimal effects on the EC 50 for ACh. However, the R57S mutation in loop G, although having minimal effect on imidacloprid's actions, reduced the affinity of thiacloprid for the (Dα1) 3 (β2) 2 nACh receptor, while scarcely affecting thiacloprid's action on the (Dα1) 2 (β2) 3 nACh receptor. Both the K140T and the combined R57S;K140T mutations reduced neonicotinoid efficacy but only for the (Dα1) 3 (β2) 2 nACh receptor. Combining the E78K mutation with the R57S;K140T mutations resulted in a selective reduction of thiacloprid's affinity for the (Dα1) 3 (β2) 2 nACh receptor. These findings suggest that a triangle of residues from loops D, E and G contribute to the selective actions of neonicotinoids on insect-vertebrate hybrid nACh receptors. This article is part of a themed section on Nicotinic Acetylcholine Receptors. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.11/issuetoc. © 2017 The British Pharmacological Society.

Functional characterization of AVPR2 mutants found in Turkish patients with nephrogenic diabetes insipidus.

PubMed

Erdem, Beril; Schulz, Angela; Saglar, Emel; Deniz, Ferhat; Schöneberg, Torsten; Mergen, Hatice

2018-01-01

Diabetes insipidus is a rare disorder characterized by an impairment in water balance because of the inability to concentrate urine. While central diabetes insipidus is caused by mutations in the AVP , the reason for genetically determined nephrogenic diabetes insipidus can be mutations in AQP2 or AVPR2 After release of AVP from posterior pituitary into blood stream, it binds to AVPR2, which is one of the receptors for AVP and is mainly expressed in principal cells of collecting ducts of kidney. Receptor activation increases cAMP levels in principal cells, resulting in the incorporation of AQP2 into the membrane, finally increasing water reabsorption. This pathway can be altered by mutations in AVPR2 causing nephrogenic diabetes insipidus. In this study, we functionally characterize four mutations (R68W, ΔR67-G69/G107W, V162A and T273M) in AVPR2, which were found in Turkish patients. Upon AVP stimulation, R68W, ΔR67-G69/G107W and T273M showed a significantly reduced maximum in cAMP response compared to wild-type receptor. All mutant receptor proteins were expressed at the protein level; however, R68W, ΔR67-G69/G107W and T273M were partially retained in the cellular interior. Immunofluorescence studies showed that these mutant receptors were trapped in ER and Golgi apparatus. The function of V162A was indistinguishable from the indicating other defects causing disease. The results are important for understanding the influence of mutations on receptor function and cellular trafficking. Therefore, characterization of these mutations provides useful information for further studies addressing treatment of intracellularly trapped receptors with cell-permeable antagonists to restore receptor function in patients with nephrogenic diabetes insipidus. © 2018 The authors.

Functional characterization of AVPR2 mutants found in Turkish patients with nephrogenic diabetes insipidus

PubMed Central

Schulz, Angela; Saglar, Emel; Deniz, Ferhat; Schöneberg, Torsten; Mergen, Hatice

2018-01-01

Diabetes insipidus is a rare disorder characterized by an impairment in water balance because of the inability to concentrate urine. While central diabetes insipidus is caused by mutations in the AVP, the reason for genetically determined nephrogenic diabetes insipidus can be mutations in AQP2 or AVPR2. After release of AVP from posterior pituitary into blood stream, it binds to AVPR2, which is one of the receptors for AVP and is mainly expressed in principal cells of collecting ducts of kidney. Receptor activation increases cAMP levels in principal cells, resulting in the incorporation of AQP2 into the membrane, finally increasing water reabsorption. This pathway can be altered by mutations in AVPR2 causing nephrogenic diabetes insipidus. In this study, we functionally characterize four mutations (R68W, ΔR67-G69/G107W, V162A and T273M) in AVPR2, which were found in Turkish patients. Upon AVP stimulation, R68W, ΔR67-G69/G107W and T273M showed a significantly reduced maximum in cAMP response compared to wild-type receptor. All mutant receptor proteins were expressed at the protein level; however, R68W, ΔR67-G69/G107W and T273M were partially retained in the cellular interior. Immunofluorescence studies showed that these mutant receptors were trapped in ER and Golgi apparatus. The function of V162A was indistinguishable from the indicating other defects causing disease. The results are important for understanding the influence of mutations on receptor function and cellular trafficking. Therefore, characterization of these mutations provides useful information for further studies addressing treatment of intracellularly trapped receptors with cell-permeable antagonists to restore receptor function in patients with nephrogenic diabetes insipidus. PMID:29117938

Identification of novel subgroup A variants with enhanced receptor binding and replicative capacity in primary isolates of anaemogenic strains of feline leukaemia virus.

PubMed

Stewart, Hazel; Adema, Karen W; McMonagle, Elizabeth L; Hosie, Margaret J; Willett, Brian J

2012-05-31

The development of anaemia in feline leukaemia virus (FeLV)-infected cats is associated with the emergence of a novel viral subgroup, FeLV-C. FeLV-C arises from the subgroup that is transmitted, FeLV-A, through alterations in the amino acid sequence of the receptor binding domain (RBD) of the envelope glycoprotein that result in a shift in the receptor usage and the cell tropism of the virus. The factors that influence the transition from subgroup A to subgroup C remain unclear, one possibility is that a selective pressure in the host drives the acquisition of mutations in the RBD, creating A/C intermediates with enhanced abilities to interact with the FeLV-C receptor, FLVCR. In order to understand further the emergence of FeLV-C in the infected cat, we examined primary isolates of FeLV-C for evidence of FeLV-A variants that bore mutations consistent with a gradual evolution from FeLV-A to FeLV-C. Within each isolate of FeLV-C, we identified variants that were ostensibly subgroup A by nucleic acid sequence comparisons, but which bore mutations in the RBD. One such mutation, N91D, was present in multiple isolates and when engineered into a molecular clone of the prototypic FeLV-A (Glasgow-1), enhanced replication was noted in feline cells. Expression of the N91D Env on murine leukaemia virus (MLV) pseudotypes enhanced viral entry mediated by the FeLV-A receptor THTR1 while soluble FeLV-A Env bearing the N91D mutation bound more efficiently to mouse or guinea pig cells bearing the FeLV-A and -C receptors. Long-term in vitro culture of variants bearing the N91D substitution in the presence of anti-FeLV gp70 antibodies did not result in the emergence of FeLV-C variants, suggesting that additional selective pressures in the infected cat may drive the subsequent evolution from subgroup A to subgroup C. Our data support a model in which variants of FeLV-A, bearing subtle differences in the RBD of Env, may be predisposed towards enhanced replication in vivo and subsequent conversion to FeLV-C. The selection pressures in vivo that drive the emergence of FeLV-C in a proportion of infected cats remain to be established.

A regional analysis of epidermal growth factor receptor (EGFR) mutated lung cancer for HSE South.

PubMed

Kelly, D; Mc Sorley, L; O'Shea, E; Mc Carthy, E; Bowe, S; Brady, C; Sui, J; Dawod, M A; O'Brien, O; Graham, D; McCarthy, J; Burke, L; Power, D; O'Reilly, S; Bambury, R M; Mahony, D O

2017-11-01

EGFR mutated lung cancer represents a subgroup with distinct clinical presentations, prognosis, and management requirements. We investigated the survival, prognostic factors, and real-world treatment of NSCLC patients with EGFR mutation in clinical practice. A retrospective review of all specimens sent for EGFR analysis from December 2009 to September 2015 was performed. Patient demographics, specimen type, EGFR mutation status/type, stage at diagnosis, treatment, response rate, and survival data were recorded. 27/334 (8%) patient specimens sent for EGFR testing tested positive for a sensitising EGFR mutation. The median age was 65 years (40-85 years). Exon 19 deletion represented the most commonly detected alteration, accounting for 39% (n = 11). First-line treatment for those with Exon 18, 19, or 21 alterations (n = 24) was with an EGFR tyrosine kinase inhibitor (TKI) in 79% (n = 19). Objective response rate among these patients was 74% and median duration of response was 13 months (range 7-35 months). The incidence of EGFR mutation in our cohort of NSCLC is 9% which is consistent with mutation incidence reported in other countries. The rate of EGFR mutation in our population is slightly below that reported internationally, but treatment outcomes are consistent with published data. Real-world patient data have important contributions to make with regard to quality measurement, incorporating patient experience into guidelines and identifying safety signals.

Gonadotropin-Releasing Hormone (GnRH) Receptor Structure and GnRH Binding

PubMed Central

Flanagan, Colleen A.; Manilall, Ashmeetha

2017-01-01

Gonadotropin-releasing hormone (GnRH) regulates reproduction. The human GnRH receptor lacks a cytoplasmic carboxy-terminal tail but has amino acid sequence motifs characteristic of rhodopsin-like, class A, G protein-coupled receptors (GPCRs). This review will consider how recent descriptions of X-ray crystallographic structures of GPCRs in inactive and active conformations may contribute to understanding GnRH receptor structure, mechanism of activation and ligand binding. The structures confirmed that ligands bind to variable extracellular surfaces, whereas the seven membrane-spanning α-helices convey the activation signal to the cytoplasmic receptor surface, which binds and activates heterotrimeric G proteins. Forty non-covalent interactions that bridge topologically equivalent residues in different transmembrane (TM) helices are conserved in class A GPCR structures, regardless of activation state. Conformation-independent interhelical contacts account for a conserved receptor protein structure and their importance in the GnRH receptor structure is supported by decreased expression of receptors with mutations of residues in the network. Many of the GnRH receptor mutations associated with congenital hypogonadotropic hypogonadism, including the Glu2.53(90) Lys mutation, involve amino acids that constitute the conserved network. Half of the ~250 intramolecular interactions in GPCRs differ between inactive and active structures. Conformation-specific interhelical contacts depend on amino acids changing partners during activation. Conserved inactive conformation-specific contacts prevent receptor activation by stabilizing proximity of TM helices 3 and 6 and a closed G protein-binding site. Mutations of GnRH receptor residues involved in these interactions, such as Arg3.50(139) of the DRY/S motif or Tyr7.53(323) of the N/DPxxY motif, increase or decrease receptor expression and efficiency of receptor coupling to G protein signaling, consistent with the native residues stabilizing the inactive GnRH receptor structure. Active conformation-specific interhelical contacts stabilize an open G protein-binding site. Progress in defining the GnRH-binding site has recently slowed, with evidence that Tyr6.58(290) contacts Tyr5 of GnRH, whereas other residues affect recognition of Trp3 and Gly10NH2. The surprisingly consistent observations that GnRH receptor mutations that disrupt GnRH binding have less effect on “conformationally constrained” GnRH peptides may now be explained by crystal structures of agonist-bound peptide receptors. Analysis of GPCR structures provides insight into GnRH receptor function. PMID:29123501

Androgen receptor signaling and mutations in prostate cancer

PubMed Central

Koochekpour, Shahriar

2010-01-01

Normal and neoplastic growth of the prostate gland are dependent on androgen receptor (AR) expression and function. Androgenic activation of the AR, in association with its coregulatory factors, is the classical pathway that leads to transcriptional activity of AR target genes. Alternatively, cytoplasmic signaling crosstalk of AR by growth factors, neurotrophic peptides, cytokines or nonandrogenic hormones may have important roles in prostate carcinogenesis and in metastatic or androgen-independent (AI) progression of the disease. In addition, cross-modulation by various nuclear transcription factors acting through basal transcriptional machinery could positively or negatively affect the AR or AR target genes expression and activity. Androgen ablation leads to an initial favorable response in a significant number of patients; however, almost invariably patients relapse with an aggressive form of the disease known as castration-resistant or hormone-refractory prostate cancer (PCa). Understanding critical molecular events that lead PCa cells to resist androgen-deprivation therapy is essential in developing successful treatments for hormone-refractory disease. In a significant number of hormone-refractory patients, the AR is overexpressed, mutated or genomically amplified. These genetic alterations maintain an active presence for a highly sensitive AR, which is responsive to androgens, antiandrogens or nonandrogenic hormones and collectively confer a selective growth advantage to PCa cells. This review provides a brief synopsis of the AR structure, AR coregulators, posttranslational modifications of AR, duality of AR function in prostate epithelial and stromal cells, AR-dependent signaling, genetic changes in the form of somatic and germline mutations and their known functional significance in PCa cells and tissues. PMID:20711217

Mutational studies reveal a complex set of positive and negative control elements within the chicken vitellogenin II promoter.

PubMed

Seal, S N; Davis, D L; Burch, J B

1991-05-01

The endogenous chicken vitellogenin II (VTGII) gene is transcribed exclusively in hepatocytes in response to estrogen. We previously identified two estrogen response elements (EREs) upstream of this gene. We now present an analysis of the VTGII promoter activated by these EREs in response to estrogen. Chimeric VTGII-CAT genes were cotransfected into LMH chicken hepatoma cells along with an estrogen receptor expression vector, and transient CAT expression was assayed after culturing the cells in the absence or presence of estrogen. An analysis of constructs bearing deletions downstream of the more proximal ERE indicated that promoter elements relevant to transcription in LMH cells extend to between -113 and -96. The relative importance of sequences within the VTGII promoter was examined by using 10 contiguous linker scanner mutations spanning the region from -117 to -24. Although most of these mutations compromised VTGII promoter function, one dramatically increased expression in LMH cells and also rendered the VTGII promoter capable of being activated by cis-linked EREs in fibroblasts cotransfected with an estrogen receptor expression vector. Gel retardation and DNase I footprinting assays revealed four factor-binding sites within this promoter. We demonstrate that three of these sites bind C/EBP, SP1, and USF (or related factors), respectively; the fourth site binds a factor that we denote TF-V beta. The biological relevance of these findings is suggested by the fact that three of these binding sites map to sites previously shown to be occupied in vivo in response to estrogen.

Effects of icotinib on early-stage non-small-cell lung cancer as neoadjuvant treatment with different epidermal growth factor receptor phenotypes.

PubMed

Wang, Tao; Liu, Yang; Zhou, Bin; Wang, Zhi; Liang, Naichao; Zhang, Yundong; Dong, Zhouhuan; Li, Jie

2016-01-01

Epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) have demonstrated efficacy in treating advanced non-small-cell lung cancer (NSCLC). Preliminary findings suggested that EGFR-TKIs might also be beneficial in neoadjuvant therapy in treating NSCLC. Therefore, this study aimed to evaluate the efficacy and safety of neoadjuvant therapy with icotinib in patients with early-stage NSCLC. We retrospectively reviewed the medical history of patients who were initially diagnosed with stage IA-IIIA NSCLC and were under icotinib administration before surgery between December 2011 and December 2014. Tumor assessment was conducted between the second and fourth week from initial icotinib treatment. The association between personal characteristics, smoking status, disease stage, EGFR mutation status, and clinical outcomes were investigated using multivariate logistic regression analysis. A total of 67 patients with NSCLC were reviewed, and approximately half (38/67) of them were identified as having EGFR-mutant tumors. The overall response rate of all patients was 26.7% at 2-4 weeks' assessment. Multivariate analysis showed that female sex (38.5% versus 10.7% in males, P=0.028) and EGFR mutation status (42.1% versus 6.9% in EGFR wild type, P=0.011) were independent predictive factors. The analysis also showed that the most common adverse effects were rash (43.3%) and dry skin (34.4%), which were tolerable. Icotinib induced clinical response with minimal toxicity as neoadjuvant treatment in early NSCLC, especially in patients with common EGFR mutations. Further studies are warranted to confirm our findings.

Identification of a novel mutation in the human growth hormone receptor gene (GHR) in a patient with Laron syndrome.

PubMed

Gennero, Isabelle; Edouard, Thomas; Rashad, Mona; Bieth, Eric; Conte-Aurio, Françoise; Marin, Françoise; Tauber, Maithé; Salles, Jean Pierre; El Kholy, Mohamed

2007-07-01

Deletions and mutations in the growth hormone receptor (GHR) gene are the underlying etiology of Laron syndrome (LS) or growth hormone (GH) insensitivity syndrome (GHIS), an autosomal recessive disease. Most patients are distributed in or originate from Mediterranean and Middle-Eastern countries. Sixty mutations have been described so far. We report a novel mutation in the GHR gene in a patient with LS. Genomic DNA sequencing of exon 5 revealed a TT insertion at nucleotide 422 after codon 122. The insertion resulted in a frameshift introducing a premature termination codon that led to a truncated receptor. We present clinical, biochemical and molecular evidence of LS as the result of this homozygous insertion.

ROS1 fusions rarely overlap with other oncogenic drivers in non-small cell lung cancer

PubMed Central

Lin, Jessica J.; Ritterhouse, Lauren L.; Ali, Siraj M.; Bailey, Mark; Schrock, Alexa B.; Gainor, Justin F.; Ferris, Lorin A.; Mino-Kenudson, Mari; Miller, Vincent A.; Iafrate, Anthony J.; Lennerz, Jochen K.; Shaw, Alice T.

2017-01-01

Introduction Chromosomal rearrangements involving the ROS proto-oncogene 1 receptor tyrosine kinase gene (ROS1) define a distinct molecular subset of non-small cell lung cancer (NSCLC) with sensitivity to ROS1 inhibitors. Recent reports have suggested a significant overlap between ROS1 fusions and other oncogenic driver alterations, including mutations in epidermal growth factor receptor (EGFR) and KRAS proto-oncogene (KRAS). Methods We identified patients at our institution with ROS1-rearranged NSCLC who had undergone testing for genetic alterations in additional oncogenes, including EGFR, KRAS, and anaplastic lymphoma kinase (ALK). Clinicopathologic features and genetic testing results were reviewed. We also examined a separate database of ROS1-rearranged NSCLCs identified through a commercial FoundationOne assay. Results Among 62 patients with ROS1-rearranged NSCLC evaluated at our institution, none harbored concurrent ALK fusions (0%) or EGFR activating mutations (0%). KRAS mutations were detected in two cases (3.2%), one of which harbored a concurrent non-canonical KRAS I24N mutation of unknown biological significance. In a separate ROS1 FISH-positive case, targeted sequencing failed to confirm a ROS1 fusion, but instead identified a KRAS G13D mutation. No concurrent mutations in BRAF, ERBB2, PIK3CA, AKT1, or MAP2K1 were detected. Analysis of an independent dataset of 166 ROS1-rearranged NSCLCs identified by FoundationOne demonstrated rare cases with co-occurring driver mutations in EGFR (1/166) and KRAS (3/166), and no cases with co-occurring ROS1 and ALK rearrangements. Conclusions ROS1 rearrangements rarely overlap with alterations in EGFR, KRAS, ALK, or other targetable oncogenes in NSCLC. PMID:28088512

The effects of ryanodine receptor (RYR1) mutation on natural killer cell cytotoxicity, plasma cytokines and stress hormones during acute intermittent exercise in pigs.

PubMed

Ciepielewski, Z M; Stojek, W; Borman, A; Myślińska, D; Pałczyńska, P; Kamyczek, M

2016-04-01

Stress susceptibility has been mapped to a single recessive gene, the ryanodine receptor 1 (RYR1) gene or halothane (Hal) gene. Homozygous (Hal(nn)), mutated pigs are sensitive to halothane and susceptible to Porcine Stress Syndrome (PSS). Previous studies have shown that stress-susceptible RYR1 gene mutated homozygotes in response to restraint stress showed an increase in natural killer cell cytotoxicity (NKCC) accompanied by more pronounced stress-related hormone and anti-inflammatory cytokine changes. In order to determine the relationship of a RYR1 gene mutation with NKCC, plasma cytokines and stress-related hormones following a different stress model - exercise - 36 male pigs (representing different genotypes according to RYR1 gene mutation: NN, homozygous dominant; Nn, heterozygous; nn, homozygous recessive) were submitted to an intermittent treadmill walking. During the entire experiment the greatest level of NKCC and the greatest concentrations of interleukin (IL-) 6, IL-10, IL-12, interferon (IFN-)γ and tumor necrosis factor-α and stress-related hormones (adrenaline, prolactin, beta-endorphin) were observed in nn pigs, and the greatest concentration of IL-1 and growth hormone in NN pigs. Immunostimulatory effects of intermittent exercise on NKCC in nn pigs were concomitant with increases in IL-2, IL-12 and IFN-γ, the potent NKCC activators. Our findings suggest that stress-susceptible pigs RYR1 gene mutated pigs develop a greater level of NKCC and cytokine production in response to exercise stress. These results suggest that the heterogeneity of immunological and neuroendocrine response to exercise stress in pigs could be influenced by RYR1 gene mutation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Targeted Therapies in NSCLC: Emerging oncogene targets following the success of EGFR

PubMed Central

Berge, Eamon M; Doebele, Robert C

2014-01-01

The diagnostic testing, treatment and prognosis of non-small cell lung cancer (NSCLC) has undergone a paradigm shift since the discovery of sensitizing mutations in the epidermal growth factor receptor (EGFR) gene in a subset of NSCLC patients. Several additional oncogenic mutations, including gene fusions and amplifications have since been discovered, with a number of drugs that target each specific oncogene. This review focuses on oncogenes in NSCLC other than EGFR and their companion ‘targeted therapies’. Particular emphasis is placed on the role of ALK, ROS1, RET, MET, BRAF, and HER2 in NSCLC. PMID:24565585

An autoinflammatory disease with deficiency of the interleukin-1-receptor antagonist.

PubMed

Aksentijevich, Ivona; Masters, Seth L; Ferguson, Polly J; Dancey, Paul; Frenkel, Joost; van Royen-Kerkhoff, Annet; Laxer, Ron; Tedgård, Ulf; Cowen, Edward W; Pham, Tuyet-Hang; Booty, Matthew; Estes, Jacob D; Sandler, Netanya G; Plass, Nicole; Stone, Deborah L; Turner, Maria L; Hill, Suvimol; Butman, John A; Schneider, Rayfel; Babyn, Paul; El-Shanti, Hatem I; Pope, Elena; Barron, Karyl; Bing, Xinyu; Laurence, Arian; Lee, Chyi-Chia R; Chapelle, Dawn; Clarke, Gillian I; Ohson, Kamal; Nicholson, Marc; Gadina, Massimo; Yang, Barbara; Korman, Benjamin D; Gregersen, Peter K; van Hagen, P Martin; Hak, A Elisabeth; Huizing, Marjan; Rahman, Proton; Douek, Daniel C; Remmers, Elaine F; Kastner, Daniel L; Goldbach-Mansky, Raphaela

2009-06-04

Autoinflammatory diseases manifest inflammation without evidence of infection, high-titer autoantibodies, or autoreactive T cells. We report a disorder caused by mutations of IL1RN, which encodes the interleukin-1-receptor antagonist, with prominent involvement of skin and bone. We studied nine children from six families who had neonatal onset of sterile multifocal osteomyelitis, periostitis, and pustulosis. Response to empirical treatment with the recombinant interleukin-1-receptor antagonist anakinra in the first patient prompted us to test for the presence of mutations and changes in proteins and their function in interleukin-1-pathway genes including IL1RN. We identified homozygous mutations of IL1RN in nine affected children, from one family from Newfoundland, Canada, three families from The Netherlands, and one consanguineous family from Lebanon. A nonconsanguineous patient from Puerto Rico was homozygous for a genomic deletion that includes IL1RN and five other interleukin-1-family members. At least three of the mutations are founder mutations; heterozygous carriers were asymptomatic, with no cytokine abnormalities in vitro. The IL1RN mutations resulted in a truncated protein that is not secreted, thereby rendering cells hyperresponsive to interleukin-1beta stimulation. Patients treated with anakinra responded rapidly. We propose the term deficiency of the interleukin-1-receptor antagonist, or DIRA, to denote this autosomal recessive autoinflammatory disease caused by mutations affecting IL1RN. The absence of interleukin-1-receptor antagonist allows unopposed action of interleukin-1, resulting in life-threatening systemic inflammation with skin and bone involvement. (ClinicalTrials.gov number, NCT00059748.) 2009 Massachusetts Medical Society

Allosteric Pathways in the PPARγ-RXRα nuclear receptor complex

NASA Astrophysics Data System (ADS)

Ricci, Clarisse G.; Silveira, Rodrigo L.; Rivalta, Ivan; Batista, Victor S.; Skaf, Munir S.

2016-01-01

Understanding the nature of allostery in DNA-nuclear receptor (NR) complexes is of fundamental importance for drug development since NRs regulate the transcription of a myriad of genes in humans and other metazoans. Here, we investigate allostery in the peroxisome proliferator-activated/retinoid X receptor heterodimer. This important NR complex is a target for antidiabetic drugs since it binds to DNA and functions as a transcription factor essential for insulin sensitization and lipid metabolism. We find evidence of interdependent motions of Ω-loops and PPARγ-DNA binding domain with contacts susceptible to conformational changes and mutations, critical for regulating transcriptional functions in response to sequence-dependent DNA dynamics. Statistical network analysis of the correlated motions, observed in molecular dynamics simulations, shows preferential allosteric pathways with convergence centers comprised of polar amino acid residues. These findings are particularly relevant for the design of allosteric modulators of ligand-dependent transcription factors.

Fibroblast growth factor receptors in breast cancer: expression, downstream effects, and possible drug targets.

PubMed

Tenhagen, M; van Diest, P J; Ivanova, I A; van der Wall, E; van der Groep, P

2012-08-01

Cancer treatments are increasingly focusing on the molecular mechanisms underlying the oncogenic processes present in tumors of individual patients. Fibroblast growth factor receptors (FGFRs) are among the many molecules that are involved in oncogenesis and are currently under investigation for their potential as drug targets in breast cancer patients. These receptor tyrosine kinases play a role in several processes including proliferation, angiogenesis, and migration. Alterations in these basal processes can contribute to the development and progression of tumors. Among breast cancer patients, several subgroups have been shown to harbor genetic aberrations in FGFRs, including amplifications of FGFR1, FGFR2, and FGFR4 and mutations in FGFR2 and FGFR4. Here, we review in vitro and in vivo models that have partly elucidated the molecular implications of these different genetic aberrations, the resulting tumor characteristics, and the potential of FGFRs as therapeutic targets for breast cancer treatment.

Lipoprotein(a) levels in familial hipercholesterolaemia: an important predictor for cardiovascular disease independent of the type of LDL-receptor mutation

USDA-ARS?s Scientific Manuscript database

To determine the relationship between lipoprotein(a) [Lp(a)] and cardiovascular disease (CVD) in a large cohort of heterozygous familial hypercholesterolemia (FH) patients. Lipoprotein(a) is considered a cardiovascular risk factor. Nevertheless, the role of Lp(a) as a predictor of CVD in FH has been...

Phenotype-genotype correlations in congenital isolated growth hormone deficiency (IGHD).

PubMed

Alatzoglou, Kyriaki S; Dattani, Mehul T

2012-01-01

Isolated growth hormone deficiency (IGHD) may be congenital, often due to genetic mutations, or acquired as a result of other factors such as cranial irradiation. The commonest genes implicated in its genetic etiology are those encoding growth hormone (GH1) and the receptor for GH-releasing hormone (GHRHR). Rarely, IGHD may be caused by mutations in transcription factors (HESX1, SOX3, OTX2) or be the first presentation before the development of other pituitary hormone deficiencies. IGHD has been classified in four genetic forms (type IA, IB, II and III). Despite the increasing number of genes implicated in the etiology of IGHD, mutations in known genes account only for a small percentage of cases; therefore, other as yet unidentified factors may be implicated in its etiology. Although there is no strict genotype/phenotype correlation in patients with IGHD, there are some emerging patterns that may guide us towards a genetic diagnosis of the condition. There is increasing understanding that the phenotype of patients with IGHD is highly variable and sometimes even evolving, dictating the need for long term follow-up in these cases.

egl-17 encodes an invertebrate fibroblast growth factor family member required specifically for sex myoblast migration in Caenorhabditis elegans

PubMed Central

Burdine, Rebecca D.; Chen, Estella B.; Kwok, Shing F.; Stern, Michael J.

1997-01-01

The proper guidance of the Caenorhabditis elegans hermaphrodite sex myoblasts (SMs) requires the genes egl-15 and egl-17. egl-15 has been shown to encode the C. elegans orthologue of the fibroblast growth factor receptor (FGFR). Here we clone egl-17 and show it to be a member of the fibroblast growth factor (FGF) family, one of the first functional invertebrate FGFs known. egl-17 shares homology with other FGF members, conserving the key residues required to form the distinctive tertiary structure common to FGFs. Genetic and molecular evidence demonstrates that the SM migration defect seen in egl-17 mutant animals represents complete loss of egl-17 function. While mutations in egl-17 affect only SM migration, mutations in egl-15 can result in larval arrest, scrawny body morphology, and the ability to suppress mutations in clr-1. We propose that EGL-17 (FGF) acts as a ligand for EGL-15 (FGFR) specifically during SM migration and that another ligand(s) activates EGL-15 for its other functions. PMID:9122212

HER2 missense mutations have distinct effects on oncogenic signaling and migration

PubMed Central

Zabransky, Daniel J.; Yankaskas, Christopher L.; Cochran, Rory L.; Wong, Hong Yuen; Croessmann, Sarah; Chu, David; Kavuri, Shyam M.; Red Brewer, Monica; Rosen, D. Marc; Dalton, W. Brian; Cimino-Mathews, Ashley; Cravero, Karen; Button, Berry; Kyker-Snowman, Kelly; Cidado, Justin; Erlanger, Bracha; Parsons, Heather A.; Manto, Kristen M.; Bose, Ron; Lauring, Josh; Arteaga, Carlos L.; Konstantopoulos, Konstantinos; Park, Ben Ho

2015-01-01

Recurrent human epidermal growth factor receptor 2 (HER2) missense mutations have been reported in human cancers. These mutations occur primarily in the absence of HER2 gene amplification such that most HER2-mutant tumors are classified as “negative” by FISH or immunohistochemistry assays. It remains unclear whether nonamplified HER2 missense mutations are oncogenic and whether they are targets for HER2-directed therapies that are currently approved for the treatment of HER2 gene-amplified breast cancers. Here we functionally characterize HER2 kinase and extracellular domain mutations through gene editing of the endogenous loci in HER2 nonamplified human breast epithelial cells. In in vitro and in vivo assays, the majority of HER2 missense mutations do not impart detectable oncogenic changes. However, the HER2 V777L mutation increased biochemical pathway activation and, in the context of a PIK3CA mutation, enhanced migratory features in vitro. However, the V777L mutation did not alter in vivo tumorigenicity or sensitivity to HER2-directed therapies in proliferation assays. Our results suggest the oncogenicity and potential targeting of HER2 missense mutations should be considered in the context of cooperating genetic alterations and provide previously unidentified insights into functional analysis of HER2 mutations and strategies to target them. PMID:26508629

Prognostic value of plasma EGFR ctDNA in NSCLC patients treated with EGFR-TKIs.

PubMed

Zhang, Chengjuan; Wei, Bing; Li, Peng; Yang, Ke; Wang, Zhizhong; Ma, Jie; Guo, Yongjun

2017-01-01

Epidermal growth factor receptor (EGFR) specific mutations have been known to improve survival of patients with non-small-cell lung carcinoma (NSCLC). However, whether there are any changes of EGFR mutations after targeted therapy and its clinical significance is unclear. This study was to identify the status of EGFR mutations after targeted therapy and predict the prognostic significance for NSCLC patients. A total of forty-five (45) NSCLC patients who received EGFR-TKI therapy were enrolled. We identified the changes of EGFR mutations in plasma ctDNA by Amplification Refractory Mutation System (ARMS) PCR technology. In the 45 cases of NSCLC with EGFR mutations, the EGFR mutation status changed in 26 cases, in which, 12 cases (26.7%) from positive to negative, and 14 cases (31.1%) from T790M mutation negative to positive after TKI targeted therapy. The T790M occurance group had a shorter Progression -Free-Survival (PFS) than the groups of EGFR mutation undetected and EGFR mutation turned out to have no change after EGFR-TKI therapy (p < 0.05). According to this study, it's necessary to closely monitor EGFR mutations during follow-up to predict the prognosis of NSCLC patients who are to receive the TKI targeted therapy.

The Effect of Coexistence of a Pair of Mutated Oncogenes on the Survival Rate of Invasive Breast Carcinoma Patients

NASA Astrophysics Data System (ADS)

Nair, D. R.

2017-12-01

The purpose of this project was to determine the effect of two mutated oncogenes on the survival rate from invasive breast carcinoma when in comparison to the mutation of a single oncogene on the survival rate. An oncogene is defined as a gene, that when mutated, can lead to cancer. The two oncogenes used in this project were human epidermal growth factor receptor 2 (HER2) and c-myc (MYC). HER2 and MYC are both oncogenes that contribute to the formation of cancer. HER2 proteins are receptors on breast cells, and when the HER2 gene is mutated, there is an overexpression of HER2 protein on the breast cell. This makes the breast cells proliferate uncontrollably. MYC is a gene that codes for a transcription factor that plays a role in cell cycle progression. The overexpression of MYC also leads to the proliferation of cells. I hypothesized that if there is a mutation in both the MYC and HER2 genes, then the survival rate of invasive breast carcinoma patients will be lower compared to patients with the mutations of only MYC or HER2. To test this hypothesis, we conducted individual gene searches in CBioPortal for HER2 in the datasets from the studies titled TCGA Nature 2012, TCGA Cell 2015, and TCGA Provisional. We conducted individual gene searches in CBioPortal for MYC in the same datasets. The survival rate data was then exported and analyzed for patients with mutations of either HER2 or MYC and with mutations of both genes. To determine the cases that had both HER2 and MYC mutations, we found the overlapping cases in both HER2 and MYC groups for all three datasets. We calculated the median of the survival data for cases where either HER2 or MYC was mutated and cases where both MYC and HER2 were mutated. From the first dataset, the median of MYC data was 95.53, HER2 data was 95.83, and both HER2 and MYC data was 91.24. In the second dataset, the median of MYC data was 92.17 , HER2 data was 93.5, and both HER2 and MYC data was 87.95 . In the third dataset, the median of MYC data was 92.18, HER2 data was 94.22, and both HER2 and MYC data was 89.45. The median survival rates all showed that cases with mutations in both genes had a lower survival rate than those with single mutations. My hypothesis was supported. Some sources of error are the fewer number of cases in the TCGA Nature 2012 dataset, making this data statistically insignificant.

Presence of atypical thrombopoietin receptor (MPL) mutations in triple-negative essential thrombocythemia patients.

PubMed

Cabagnols, Xénia; Favale, Fabrizia; Pasquier, Florence; Messaoudi, Kahia; Defour, Jean Philippe; Ianotto, Jean Christophe; Marzac, Christophe; Le Couédic, Jean Pierre; Droin, Nathalie; Chachoua, Ilyas; Favier, Remi; Diop, M'boyba Khadija; Ugo, Valérie; Casadevall, Nicole; Debili, Najet; Raslova, Hana; Bellanné-Chantelot, Christine; Constantinescu, Stefan N; Bluteau, Olivier; Plo, Isabelle; Vainchenker, William

2016-01-21

Mutations in signaling molecules of the cytokine receptor axis play a central role in myeloproliferative neoplasm (MPN) pathogenesis. Polycythemia vera is mainly related to JAK2 mutations, whereas a wider mutational spectrum is detected in essential thrombocythemia (ET) with mutations in JAK2, the thrombopoietin (TPO) receptor (MPL), and the calreticulin (CALR) genes. Here, we studied the mutational profile of 17 ET patients negative for JAK2V617F, MPLW515K/L, and CALR mutations, using whole-exome sequencing and next-generation sequencing (NGS) targeted on JAK2 and MPL. We found several signaling mutations including JAK2V617F at very low allele frequency, 1 homozygous SH2B3 mutation, 1 MPLS505N, 1 MPLW515R, and 2 MPLS204P mutations. In the remaining patients, 4 presented a clonal and 7 a polyclonal hematopoiesis, suggesting that certain triple-negative ETs are not MPNs. NGS on 26 additional triple-negative ETs detected only 1 MPLY591N mutation. Functional studies on MPLS204P and MPLY591N revealed that they are weak gain-of-function mutants increasing MPL signaling and conferring either TPO hypersensitivity or independence to expressing cells, but with a low efficiency. Further studies should be performed to precisely determine the frequency of MPLS204 and MPLY591 mutants in a bigger cohort of MPN. © 2016 by The American Society of Hematology.

Mutations in the Polybasic Juxtamembrane Sequence of Both Plasma Membrane- and Endoplasmic Reticulum-localized Epidermal Growth Factor Receptors Confer Ligand-independent Cell Transformation*

PubMed Central

Bryant, Kirsten L.; Antonyak, Marc A.; Cerione, Richard A.; Baird, Barbara; Holowka, David

2013-01-01

Deregulation of ErbB receptor-tyrosine kinases is a hallmark of many human cancers. Conserved in the ErbB family is a cluster of basic amino acid residues in the cytoplasmic juxtamembrane region. We found that charge-silencing mutagenesis within this juxtamembrane region of the epidermal growth factor receptor (EGFR) results in the generation of a mutant receptor (EGFR Mut R1-6) that spontaneously transforms NIH 3T3 cells in a ligand-independent manner. A similar mutant with one additional basic residue, EGFR Mut R1-5, fails to exhibit ligand-independent transformation. The capacity of EGFR Mut R1-6 to mediate this transformation is maintained when this mutant is retained in the endoplasmic reticulum via a single point mutation, L393H, which we describe. We show that EGFR Mut R1-6 with or without L393H exhibits enhanced basal tyrosine phosphorylation when ectopically expressed, and the ligand-independent transforming activity of EGFR Mut R1-6 is sensitive to inhibition of EGFR kinase activity and is particularly dependent on PI3K and mTOR activity. Similar to EGFR Mut R1-6/L393H in NIH 3T3 cells, EGFR variant type III, a highly oncogenic mutant form of EGFR linked to human brain cancers, confers transforming activity while it is wholly endoplasmic reticulum-retained in U87 cells. Our findings highlight the importance of the polybasic juxtamembrane sequence in regulating the oncogenic potential of EGFR signaling. PMID:24142702

Non-Small Cell Lung Cancer Cells Acquire Resistance to the ALK Inhibitor Alectinib by Activating Alternative Receptor Tyrosine Kinases.

PubMed

Isozaki, Hideko; Ichihara, Eiki; Takigawa, Nagio; Ohashi, Kadoaki; Ochi, Nobuaki; Yasugi, Masayuki; Ninomiya, Takashi; Yamane, Hiromichi; Hotta, Katsuyuki; Sakai, Katsuya; Matsumoto, Kunio; Hosokawa, Shinobu; Bessho, Akihiro; Sendo, Toshiaki; Tanimoto, Mitsune; Kiura, Katsuyuki

2016-03-15

Crizotinib is the standard of care for advanced non-small cell lung cancer (NSCLC) patients harboring the anaplastic lymphoma kinase (ALK) fusion gene, but resistance invariably develops. Unlike crizotinib, alectinib is a selective ALK tyrosine kinase inhibitor (TKI) with more potent antitumor effects and a favorable toxicity profile, even in crizotinib-resistant cases. However, acquired resistance to alectinib, as for other TKIs, remains a limitation of its efficacy. Therefore, we investigated the mechanisms by which human NSCLC cells acquire resistance to alectinib. We established two alectinib-resistant cell lines that did not harbor the secondary ALK mutations frequently occurring in crizotinib-resistant cells. One cell line lost the EML4-ALK fusion gene, but exhibited increased activation of insulin-like growth factor-1 receptor (IGF1R) and human epidermal growth factor receptor 3 (HER3), and overexpressed the HER3 ligand neuregulin 1. Accordingly, pharmacologic inhibition of IGF1R and HER3 signaling overcame resistance to alectinib in this cell line. The second alectinib-resistant cell line displayed stimulated HGF autocrine signaling that promoted MET activation and remained sensitive to crizotinib treatment. Taken together, our findings reveal two novel mechanisms underlying alectinib resistance that are caused by the activation of alternative tyrosine kinase receptors rather than by secondary ALK mutations. These studies may guide the development of comprehensive treatment strategies that take into consideration the various approaches ALK-positive lung tumors use to withstand therapeutic insult. ©2015 American Association for Cancer Research.

Preselection of EGFR mutations in non-small-cell lung cancer patients by immunohistochemistry: comparison with DNA-sequencing, EGFR wild-type expression, gene copy number gain and clinicopathological data.

PubMed

Gaber, Rania; Watermann, Iris; Kugler, Christian; Vollmer, Ekkehard; Perner, Sven; Reck, Martin; Goldmann, Torsten

2017-01-01

Targeting epidermal growth factor receptor (EGFR) in patients with non-small-cell lung cancer (NSCLC) having EGFR mutations is associated with an improved overall survival. The aim of this study is to verify, if EGFR mutations detected by immunohistochemistry (IHC) is a convincing way to preselect patients for DNA-sequencing and to figure out, the statistical association between EGFR mutation, wild-type EGFR overexpression, gene copy number gain, which are the main factors inducing EGFR tumorigenic activity and the clinicopathological data. Two hundred sixteen tumor tissue samples of primarily chemotherapeutic naïve NSCLC patients were analyzed for EGFR mutations E746-A750del and L858R and correlated with DNA-sequencing. Two hundred six of which were assessed by IHC, using 6B6 and 43B2 specific antibodies followed by DNA-sequencing of positive cases and 10 already genotyped tumor tissues were also included to investigate debugging accuracy of IHC. In addition, EGFR wild-type overexpression was IHC evaluated and EGFR gene copy number determination was performed by fluorescence in situ hybridization (FISH). Forty-one÷206 (19.9%) cases were positive for mutated EGFR by IHC. Eight of them had EGFR mutations of exons 18-21 by DNA-sequencing. Hit rate of 10 already genotyped NSCLC mutated cases was 90% by IHC. Positive association was found between EGFR mutations determined by IHC and both EGFR overexpression and increased gene copy number (p=0.002 and p<0.001, respectively). Additionally, positive association was detected between EGFR mutations, high tumor grade and clinical stage (p<0.001). IHC staining with mutation specific antibodies was demonstrated as a possible useful screening test to preselect patients for DNA-sequencing.

Presenilin 1 mutations influence processing and trafficking of the ApoE receptor apoER2.

PubMed

Wang, Wei; Moerman-Herzog, Andrea M; Slaton, Arthur; Barger, Steven W

2017-01-01

Presenilin (PS)-1 is an intramembrane protease serving as the catalytic component of γ-secretase. Mutations in the PS1 gene are the most common cause of familial Alzheimer's disease (FAD). The low-density lipoprotein (LDL)-receptor family member apoER2 is a γ-secretase substrate that has been associated with AD in several ways, including acting as a receptor for apolipoprotein E (ApoE). ApoER2 is processed by γ-secretase into a C-terminal fragment (γ-CTF) that appears to regulate gene expression. FAD PS1 mutations were tested for effects on apoER2. PS1 mutation R278I showed impaired γ-secretase activity for apoER2 in the basal state or after exposure to Reelin. PS1 M146V mutation permitted accumulation of apoER2 CTFs after Reelin treatment, whereas no difference was seen between wild-type (WT) and M146V in the basal state. PS1 L282V mutation, combined with the γ-secretase inhibitor N-(N-[3,5-Difluorophenacetyl]-L-alanyl)-S-phenylglycine t-butyl ester, greatly reduced the cell-surface levels of apoER2 without affecting total apoER2 levels, suggesting a defect in receptor trafficking. These findings indicate that impaired processing or localization of apoER2 may contribute to the pathogenic effects of FAD mutations in PS1. Published by Elsevier Inc.

Muenke Syndrome Mutation, FgfR3P244R, Causes TMJ Defects

PubMed Central

Yasuda, T.; Nah, H.D.; Laurita, J.; Kinumatsu, T.; Shibukawa, Y.; Shibutani, T.; Minugh-Purvis, N.; Pacifici, M.; Koyama, E.

2012-01-01

Muenke syndrome is characterized by various craniofacial deformities and is caused by an autosomal-dominant activating mutation in fibroblast growth factor receptor 3 (FGFR3P250R). Here, using mice carrying a corresponding mutation (FgfR3P244R), we determined whether the mutation affects temporomandibular joint (TMJ) development and growth. In situ hybridization showed that FgfR3 was expressed in condylar chondroprogenitors and maturing chondrocytes that also expressed the Indian hedgehog (Ihh) receptor and transcriptional target Patched 1(Ptch1). In FgfR3P244R mutants, the condyles displayed reduced levels of Ihh expression, H4C-positive proliferating chondroprogenitors, and collagen type II- and type X-expressing chondrocytes. Primary bone spongiosa formation was also disturbed and was accompanied by increased osteoclastic activity and reduced trabecular bone formation. Treatment of wild-type condylar explants with recombinant FGF2/FGF9 decreased Ptch1 and PTHrP expression in superficial/polymorphic layers and proliferation in chondroprogenitors. We also observed early degenerative changes of condylar articular cartilage, abnormal development of the articular eminence/glenoid fossa in the TMJ, and fusion of the articular disc. Analysis of our data indicates that the activating FgfR3P244R mutation disturbs TMJ developmental processes, likely by reducing hedgehog signaling and endochondral ossification. We suggest that a balance between FGF and hedgehog signaling pathways is critical for the integrity of TMJ development and for the maintenance of cellular organization. PMID:22622662

EGFR T790M mutation testing within the osimertinib AURA Phase I study.

PubMed

Dearden, Simon; Brown, Helen; Jenkins, Suzanne; Thress, Kenneth S; Cantarini, Mireille; Cole, Rebecca; Ranson, Malcolm; Jänne, Pasi A

2017-07-01

Reliable epidermal growth factor receptor (EGFR) mutation testing techniques are required to identify eligible patients with EGFR mutation/T790M positive advanced non-small cell lung cancer (NSCLC), for treatment with osimertinib (AZD9291), an oral, potent, irreversible EGFR tyrosine kinase inhibitor (TKI) selective for EGFR-TKI-sensitizing and T790M resistance mutations over wild-type EGFR. There is no current consensus regarding the best method to detect EGFR T790M mutations. The aim of this study was to describe the concordance between local testing, which used a variety of methods, and central testing, using the cobas ® EGFR Mutation Test, for EGFR-sensitizing mutations and the T790M resistance mutation. Tumor samples were obtained from all patients screened for inclusion onto the osimertinib Phase I expansion component of the AURA Phase I/II study (NCT01802632). Samples underwent central laboratory testing for EGFR-sensitizing mutations and T790M resistance mutation using the cobas ® EGFR Mutation Test. Results were compared with local laboratory test results, based on other testing methodologies including Sanger sequencing, therascreen ® , PNAClamp™, and Sequenom MassARRAY ® . Central laboratory testing was successful in 99% of samples passing histopathology review and testing success rates were comparable across the three central laboratories. Concordance between central and local testing for common sensitizing mutations was high (>98%) and concordance for the T790M mutation was also high (>90%). Tumor heterogeneity, along with other technical factors may have influenced this result. Within the osimertinib AURA Phase I study, EGFR mutation testing across three centralized laboratories using the cobas ® EGFR Mutation Test was feasible and successful, with strong concordance between local and central laboratory results, including for T790M. The cobas ® EGFR Mutation Test has subsequently been approved as the companion diagnostic test for osimertinib in the USA and Japan. Copyright © 2017 Elsevier B.V. All rights reserved.

Mutation analysis of the muscarinic cholinergic receptor genes in isolated growth hormone deficiency type IB.

PubMed

Mohamadi, Ali; Martari, Marco; Holladay, Cindy D; Phillips, John A; Mullis, Primus E; Salvatori, Roberto

2009-07-01

Isolated GH deficiency (IGHD) is familial in 5-30% of patients. The most frequent form (IGHD-IB) has autosomal recessive inheritance, and it is known that it can be caused by mutations in the GHRH receptor (GHRHR) gene or in the GH gene. However, most forms of IGHD-IB have an unknown genetic cause. In normal subjects, muscarinic cholinergic stimulation causes an increase in pituitary GH release, whereas its blockade has the opposite effect, suggesting that a muscarinic acetylcholine receptor (mAchR) is involved in stimulating GH secretion. Five types of mAchR (M(1)-M(5)) exist. A transgenic mouse in which the function of the M(3) receptor was selectively ablated in the central nervous system has isolated GH deficiency similar to animals with defective GHRH or GHRHR gene. We hypothesized that mAchR mutations may cause a subset of familial IGHD. After confirming the expression of M(1)-M(5) receptor mRNA in human hypothalamus, we analyzed the index cases of 39 families with IGHD-IB for mutations in the genes encoding for the five receptors. Coding sequences for each of the five mAchRs were subjected to direct sequencing. In one family, an affected member was homozygous for a M(3) change in codon 65 that replaces valine with isoleucine (V65I). The V65I receptor was expressed in CHO cells where it had normal ability to transmit methacholine signaling. mAchR mutations are absent or rare (less than 2.6%) in familial IGHD type IB.

Cardiotrophin-like cytokine factor 1 (CLCF1) and neuropoietin (NP) signalling and their roles in development, adulthood, cancer and degenerative disorders.

PubMed

Sims, Natalie A

2015-10-01

Mutations in cardiotrophin-like cytokine factor (CLCF1) and the related cytokine to which it binds, cytokine receptor-like factor 1 (CRLF1), are associated with Crisponi/cold induced sweating syndromes, and lead to early neonatal death in mice due to a suckling defect. These cytokines are members of the IL-6 superfamily, and form a range of composite cytokines that signal through gp130 bound either to the ciliary neurotrophic factor receptor (CNTFR) or a complex that involves the IL-27 p28 subunit. This review describes current knowledge of the signalling complexes formed by these cytokines, and explores their described and suggested roles in the neural, haematopoietic, skeletal, renal, immune and respiratory systems during development and adulthood, and in degenerative diseases and cancer. Copyright © 2015 Elsevier Ltd. All rights reserved.

Mutation spectrum of the FZD-4, TSPAN12 AND ZNF408 genes in Indian FEVR patients.

PubMed

Musada, Ganeswara Rao; Syed, Hameed; Jalali, Subhadra; Chakrabarti, Subhabrata; Kaur, Inderjeet

2016-06-17

Mutations in candidate genes that encode for a ligand (NDP) and receptor complex (FZD4, LRP5 and TSPAN12) in the Norrin β-catenin signaling pathway are involved in the pathogenesis of familial exudative vitreoretinopathy (FEVR, MIM # 133780). Recently, a transcription factor (ZNF408) has also been implicated in FEVR. We had earlier characterized the variations in NDP among FEVR patients from India. The present study aimed at understanding the involvement of the remaining genes (FZD4, TSPAN12 and ZNF408) in the same cohort. The DNA of 110 unrelated FEVR patients and 115 unaffected controls were screened for variations in the entire coding and untranslated regions of these 3 genes by resequencing. Segregation of the disease-associated variants was assessed in the family members of the probands. The effect of the observed missense changes were further analyzed by SIFT and PolyPhen-2 scores. The screening of FZD4, TSPAN12 and ZNF408 genes identified 11 different mutations in 15/110 FEVR probands. Of the 11 identified mutations, 6 mutations were novel. The detected missense mutations were mainly located in the domains which are functionally crucial for the formation of ligand-receptor complex and as they replaced evolutionarily highly conserved amino acids with a SIFT score < 0.005, they are predicted to be pathogenic. Additionally 2 novel and 16 reported single nucleotide polymorphisms (SNP) were also detected. Our genetic screening revealed varying mutation frequencies in the FZD4 (8.0 %), TSPAN12 (5.4 %) and ZNF408 (2.7 %) genes among the FEVR patients, indicating their potential role in the disease pathogenesis. The observed mutations segregated with the disease phenotype and exhibited variable expressivity. The mutations in FZD4 and TSPAN12 were involved in autosomal dominant and autosomal recessive families and further validates the involvement of these gene in FEVR development.

Prognostic factors of afatinib as a first-line therapy for advanced EGFR mutation-positive lung adenocarcinoma: a real-world, large cohort study.

PubMed

Liang, Sheng-Kai; Lee, Meng-Rui; Liao, Wei-Yu; Ho, Chao-Chi; Ko, Jen-Chung; Shih, Jin-Yuan

2018-05-04

Lung cancer remains the primary cause of cancer-related mortality worldwide. Several treatment modalities are available for lung cancer, including surgery, radiation, and chemotherapy. Among the chemotherapeutics available, afatinib has been shown to be effective for those with epidermal growth factor receptor ( EGFR ) mutation-positive lung adenocarcinoma. Herein, we analyzed the factors affecting the prognosis of patients who received afatinib as a first-line therapy for advanced EGFR mutation-positive lung adenocarcinoma in the real-world setting. Patients who received afatinib as a first-line therapy and were reimbursed by the National Health Insurance were recruited in this study. Data on patient characteristics and treatment courses were collected. In total, 259 patients were enrolled (median follow-up, 22.0 months). Of them, 82 (31.7%) were identified to have brain metastases at baseline, which were associated with poor Eastern Cooperative Oncology Group performance status, high incidence of central nervous system progression, and short overall survival. However, the results of our analysis showed that overall survival was not affected by reductions in the afatinib dosage or any upfront local treatments for brain tumors. Multivariate analyses showed that brain metastases at diagnosis and treatment response to afatinib are two important prognostic factors for the overall survival of patients with EGFR mutation-positive lung adenocarcinoma.

Heterogeneity-based, multiple mechanisms in the resistance to osimertinib (AZD9291): A case report.

PubMed

Liu, Yutao; Hao, Xuezhi; Hu, Xingsheng; Li, Junling; Wang, Yan; Wang, Hongyu; Xing, Puyuan; Li, Weihua; Ying, Jianming; Han, Xiaohong; Shi, Yuankai

2018-04-01

Osimertinib is a novel, irreversible, mutant-selective epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor targeting EGFR mutations and the EGFR T790 mutation. Here, we report a woman with EGFR-mutated lung adenocarcinoma who, after 23-month treatment with gefitinib, developed the EGFR T790M mutation, which converted the T790M status from positive to negative before osimertinib treatment and developed MET amplification, leading to rapid progression on osimertinib in two months. Subsequent treatment with crizotinib and c-Met inhibitor plus gefitinib also failed to improve the clinical outcome, suggesting the potential existence of another resistance mechanism. Our findings revealed the underlying multiple and heterogeneous mechanisms in resistance to osimertinib, suggesting combination strategies should be considered post-osimertinib progression. © 2018 The Authors. Thoracic Cancer published by China Lung Oncology Group and John Wiley & Sons Australia, Ltd.

Germline MC1R status influences somatic mutation burden in melanoma.

PubMed

Robles-Espinoza, Carla Daniela; Roberts, Nicola D; Chen, Shuyang; Leacy, Finbarr P; Alexandrov, Ludmil B; Pornputtapong, Natapol; Halaban, Ruth; Krauthammer, Michael; Cui, Rutao; Timothy Bishop, D; Adams, David J

2016-07-12

The major genetic determinants of cutaneous melanoma risk in the general population are disruptive variants (R alleles) in the melanocortin 1 receptor (MC1R) gene. These alleles are also linked to red hair, freckling, and sun sensitivity, all of which are known melanoma phenotypic risk factors. Here we report that in melanomas and for somatic C>T mutations, a signature linked to sun exposure, the expected single-nucleotide variant count associated with the presence of an R allele is estimated to be 42% (95% CI, 15-76%) higher than that among persons without an R allele. This figure is comparable to the expected mutational burden associated with an additional 21 years of age. We also find significant and similar enrichment of non-C>T mutation classes supporting a role for additional mutagenic processes in melanoma development in individuals carrying R alleles.

Unravelling signal escape through maintained EGFR activation in advanced non-small cell lung cancer (NSCLC): new treatment options

PubMed Central

Remon, Jordi; Besse, Benjamin

2016-01-01

The discovery of activating epidermal growth factor receptor (EGFR) mutations has opened up a new era in the development of more effective treatments for patients with non-small cell lung cancer (NSCLC). However, patients with EGFR-activating mutated NSCLC treated with EGFR tyrosine kinase inhibitors (TKIs) ultimately develop acquired resistance (AR). Among known cases of patients with AR, 70% of the mechanisms involved in the development of AR to EGFR TKI have been identified and may be categorised as either secondary EGFR mutations such as the T790M mutation, activation of bypass track signalling pathways such as MET amplification, or histologic transformation. EGFR-mutant NSCLC tumours maintain oncogenic addiction to the EGFR pathway beyond progression with EGFR TKI. Clinical strategies that can be implemented in daily clinical practice to potentially overcome this resistance and prolong the outcome in this subgroup of patients are presented. PMID:27843631

Prevalence and influence of cys407* Grm2 mutation in Hannover-derived Wistar rats: mGlu2 receptor loss links to alcohol intake, risk taking and emotional behaviour.

PubMed

Wood, Christian M; Nicolas, Celine S; Choi, Sun-Lim; Roman, Erika; Nylander, Ingrid; Fernandez-Teruel, Alberto; Kiianmaa, Kalervo; Bienkowski, Przemyslaw; de Jong, Trynke R; Colombo, Giancarlo; Chastagnier, Denis; Wafford, Keith A; Collingridge, Graham L; Wildt, Sheryl J; Conway-Campbell, Becky L; Robinson, Emma S J; Lodge, David

2017-03-15

Modulation of metabotropic glutamate 2 (mGlu2) receptor function has huge potential for treating psychiatric and neurological diseases. Development of drugs acting on mGlu2 receptors depends on the development and use of translatable animal models of disease. We report here a stop codon mutation at cysteine 407 in Grm2 (cys407*) that is common in some Wistar rats. Therefore, researchers in this field need to be aware of strains with this mutation. Our genotypic survey found widespread prevalence of the mutation in commercial Wistar strains, particularly those known as Han Wistar. Such Han Wistar rats are ideal for research into the separate roles of mGlu2 and mGlu3 receptors in CNS function. Previous investigations, unknowingly using such mGlu2 receptor-lacking rats, provide insights into the role of mGlu2 receptors in behaviour. The Grm2 mutant rats, which dominate some selectively bred lines, display characteristics of altered emotionality, impulsivity and risk-related behaviours and increased voluntary alcohol intake compared with their mGlu2 receptor-competent counterparts. In addition, the data further emphasize the potential therapeutic role of mGlu2 receptors in psychiatric and neurological disease, and indicate novel methods of studying the role of mGlu2 and mGlu3 receptors. This article is part of the Special Issue entitled 'Metabotropic Glutamate Receptors, 5 years on'. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

A Structural Perspective on the Regulation of the EGF Receptor

PubMed Central

Kovacs, Erika; Zorn, Julie Anne; Huang, Yongjian; Barros, Tiago; Kuriyan, John

2015-01-01

The epidermal growth factor receptor (EGFR) is a receptor tyrosine kinase that plays a critical role in the pathogenesis of many cancers. EGFR is unique in that its ligand-induced dimerization is established solely by contacts between regions of the receptor that are occluded within the monomeric, unliganded state. Activation of EGFR depends on the formation of an asymmetric dimer of the intracellular module of two receptor molecules, a configuration observed in crystal structures of the EGFR kinase domain in the active state. Coupling between the extracellular and intracellular modules is achieved by a switch between alternative geometries of the transmembrane and juxtamembrane segments within the receptor dimer. As the structure of the full-length receptor is yet to be determined, here we review recent structural studies on isolated modules of EGFR and molecular dynamics simulations that have provided much of our current understanding of its signaling mechanism, including how its regulation is compromised by oncogenic mutations. PMID:25621509

Recurrent mutation of IGF signalling genes and distinct patterns of genomic rearrangement in osteosarcoma

DOE PAGES

Behjati, Sam; Tarpey, Patrick S.; Haase, Kerstin; ...

2017-06-23

Osteosarcoma is a primary malignancy of bone that affects children and adults. Here, we present the largest sequencing study of osteosarcoma to date, comprising 112 childhood and adult tumours encompassing all major histological subtypes. A key finding of our study is the identification of mutations in insulin-like growth factor (IGF) signalling genes in 8/112 (7%) of cases. We validate this observation using fluorescence in situ hybridization (FISH) in an additional 87 osteosarcomas, with IGF1 receptor (IGF1R) amplification observed in 14% of tumours. These findings may inform patient selection in future trials of IGF1R inhibitors in osteosarcoma. Analysing patterns of mutation,more » we identify distinct rearrangement profiles including a process characterized by chromothripsis and amplification. This process operates recurrently at discrete genomic regions and generates driver mutations. Lastly, it may represent an age-independent mutational mechanism that contributes to the development of osteosarcoma in children and adults alike.« less

A common FGFR3 gene mutation is present in achondroplasia but not in hypochondroplasia.

PubMed

Stoilov, I; Kilpatrick, M W; Tsipouras, P

1995-01-02

Achondroplasia is the most common type of genetic dwarfism. It is characterized by disproportionate short stature and other skeletal anomalies resulting from a defect in the maturation of the chondrocytes in the growth plate of the cartilage. Recent studies mapped the achondroplasia gene on chromosome region 4p16.3 and identified a common mutation in the gene encoding the fibroblast growth factor receptor 3 (FGFR3). In an analysis of 19 achondroplasia families from a variety of ethnic backgrounds we confirmed the presence of the G380R mutation in 21 of 23 achondroplasia chromosomes studied. In contrast, the G380R mutation was not found in any of the 8 hypochondroplasia chromosomes studied. Furthermore, linkage studies in a 3-generation family with hypochondroplasia show discordant segregation with markers in the 4p16.3 region suggesting that at least some cases of hypochondroplasia are caused by mutations in a gene other than FGFR3.

Recurrent mutation of IGF signalling genes and distinct patterns of genomic rearrangement in osteosarcoma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Behjati, Sam; Tarpey, Patrick S.; Haase, Kerstin

Osteosarcoma is a primary malignancy of bone that affects children and adults. Here, we present the largest sequencing study of osteosarcoma to date, comprising 112 childhood and adult tumours encompassing all major histological subtypes. A key finding of our study is the identification of mutations in insulin-like growth factor (IGF) signalling genes in 8/112 (7%) of cases. We validate this observation using fluorescence in situ hybridization (FISH) in an additional 87 osteosarcomas, with IGF1 receptor (IGF1R) amplification observed in 14% of tumours. These findings may inform patient selection in future trials of IGF1R inhibitors in osteosarcoma. Analysing patterns of mutation,more » we identify distinct rearrangement profiles including a process characterized by chromothripsis and amplification. This process operates recurrently at discrete genomic regions and generates driver mutations. Lastly, it may represent an age-independent mutational mechanism that contributes to the development of osteosarcoma in children and adults alike.« less

Prevalence of EGFR Mutations in Lung Cancer in Uruguayan Population

PubMed Central

Touya, Diego; Bertoni, Bernardo; Osinaga, Eduardo; Varangot, Mario

2017-01-01

Background Incorporation of molecular analysis of the epidermal growth factor receptor (EGFR) gene into routine clinical practice represents a milestone for personalized therapy of the non-small-cell lung cancer (NSCLC). However, the genetic testing of EGFR mutations has not yet become a routine clinical practice in developing countries. In view of different prevalence of such mutations among different ethnicities and geographic regions, as well as the limited existing data from Latin America, our aim was to study the frequency of major types of activating mutations of the EGFR gene in NSCLC patients from Uruguay. Methods We examined EGFR mutations in exons 18 through 21 in 289 NSCLC Uruguayan patients by PCR-direct sequencing. Results EGFR mutations were detected in 53 of the 289 (18.3%) patients, more frequently in women (23.4%) than in men (14.5%). The distribution by exon was similar to that generally reported in the literature. Conclusions This first epidemiological study of EGFR mutations in Uruguay reveals a wide spectrum of mutations and an overall prevalence of 18.3%. The background ethnic structure of the Uruguayan population could play an important role in explaining our findings. PMID:28744312

CVID-associated TACI mutations affect autoreactive B cell selection and activation

PubMed Central

Romberg, Neil; Chamberlain, Nicolas; Saadoun, David; Gentile, Maurizio; Kinnunen, Tuure; Ng, Yen Shing; Virdee, Manmeet; Menard, Laurence; Cantaert, Tineke; Morbach, Henner; Rachid, Rima; Martinez-Pomar, Natalia; Matamoros, Nuria; Geha, Raif; Grimbacher, Bodo; Cerutti, Andrea; Cunningham-Rundles, Charlotte; Meffre, Eric

2013-01-01

Common variable immune deficiency (CVID) is an assorted group of primary diseases that clinically manifest with antibody deficiency, infection susceptibility, and autoimmunity. Heterozygous mutations in the gene encoding the tumor necrosis factor receptor superfamily member TACI are associated with CVID and autoimmune manifestations, whereas two mutated alleles prevent autoimmunity. To assess how the number of TACI mutations affects B cell activation and tolerance checkpoints, we analyzed healthy individuals and CVID patients carrying one or two TACI mutations. We found that TACI interacts with the cleaved, mature forms of TLR7 and TLR9 and plays an important role during B cell activation and the central removal of autoreactive B cells in healthy donors and CVID patients. However, only subjects with a single TACI mutation displayed a breached immune tolerance and secreted antinuclear antibodies (ANAs). These antibodies were associated with the presence of circulating B cell lymphoma 6–expressing T follicular helper (Tfh) cells, likely stimulating autoreactive B cells. Thus, TACI mutations may favor CVID by altering B cell activation with coincident impairment of central B cell tolerance, whereas residual B cell responsiveness in patients with one, but not two, TACI mutations enables autoimmune complications. PMID:24051380

Response to Growth Hormone Treatment in a Patient with Insulin-Like Growth Factor 1 Receptor Deletion

PubMed Central

Mahmoud, Ranim; Naidu, Ajanta; Risheg, Hiba; Kimonis, Virginia

2017-01-01

We report a six-year-old boy who presented with short stature, microcephaly, dysmorphic features, and developmental delay and who was identified with a terminal deletion of 15q26.2q26.3 containing the insulin-like growth factor receptor (IGF1R) gene in addition to a terminal duplication of the 4q35.1q35.2 region. We compare our case with other reports of deletions and mutations affecting the IGF1R gene associated with pre-and postnatal growth restriction. We report the dramatic response to growth hormone therapy in this patient which highlights the importance of identifying patients with IGF1R deletion and treating them early. PMID:28720553

Response to Growth Hormone Treatment in a Patient with Insulin-Like Growth Factor 1 Receptor Deletion.

PubMed

Mahmoud, Ranim; Naidu, Ajanta; Risheg, Hiba; Kimonis, Virginia

2017-12-15

We report a six-year-old boy who presented with short stature, microcephaly, dysmorphic features, and developmental delay and who was identified with a terminal deletion of 15q26.2q26.3 containing the insulin-like growth factor receptor (IGF1R) gene in addition to a terminal duplication of the 4q35.1q35.2 region. We compare our case with other reports of deletions and mutations affecting the IGF1R gene associated with pre-and postnatal growth restriction. We report the dramatic response to growth hormone therapy in this patient which highlights the importance of identifying patients with IGF1R deletion and treating them early.

Structural signatures of DRD4 mutants revealed using molecular dynamics simulations: Implications for drug targeting.

PubMed

Jatana, Nidhi; Thukral, Lipi; Latha, N

2016-01-01

Human Dopamine Receptor D4 (DRD4) orchestrates several neurological functions and represents a target for many psychological disorders. Here, we examined two rare variants in DRD4; V194G and R237L, which elicit functional alterations leading to disruption of ligand binding and G protein coupling, respectively. Using atomistic molecular dynamics (MD) simulations, we provide in-depth analysis to reveal structural signatures of wild and mutant complexes with their bound agonist and antagonist ligands. We constructed intra-protein network graphs to discriminate the global conformational changes induced by mutations. The simulations also allowed us to elucidate the local side-chain dynamical variations in ligand-bound mutant receptors. The data suggest that the mutation in transmembrane V (V194G) drastically disrupts the organization of ligand binding site and causes disorder in the native helical arrangement. Interestingly, the R237L mutation leads to significant rewiring of side-chain contacts in the intracellular loop 3 (site of mutation) and also affects the distant transmembrane topology. Additionally, these mutations lead to compact ICL3 region compared to the wild type, indicating that the receptor would be inaccessible for G protein coupling. Our findings thus reveal unreported structural determinants of the mutated DRD4 receptor and provide a robust framework for design of effective novel drugs.

Nuclear receptors and pathogenesis of pancreatic cancer

PubMed Central

Polvani, Simone; Tarocchi, Mirko; Tempesti, Sara; Galli, Andrea

2014-01-01

Pancreatic ductal adenocarcinoma (PDAC) is a devastating disease with a median overall survival time of 5 mo and the five years survival less than 5%, a rate essentially unchanged over the course of the years. A well defined progression model of accumulation of genetic alterations ranging from single point mutations to gross chromosomal abnormalities has been introduced to describe the origin of this disease. However, due to the its subtle nature and concurring events PDAC cure remains elusive. Nuclear receptors (NR) are members of a large superfamily of evolutionarily conserved ligand-regulated DNA-binding transcription factors functionally involved in important cellular functions ranging from regulation of metabolism, to growth and development. Given the nature of their ligands, NR are very tempting drug targets and their pharmacological modulation has been widely exploited for the treatment of metabolic and inflammatory diseases. There are now clear evidences that both classical ligand-activated and orphan NR are involved in the pathogenesis of PDAC from its very early stages; nonetheless many aspects of their role are not fully understood. The purpose of this review is to highlight the striking connections that link peroxisome proliferator activated receptors, retinoic acid receptors, retinoid X receptor, androgen receptor, estrogen receptors and the orphan NR Nur, chicken ovalbumin upstream promoter transcription factor II and the liver receptor homologue-1 receptor to PDAC development, connections that could lead to the identification of novel therapies for this disease. PMID:25232244

Mast cells and mastocytosis

PubMed Central

2008-01-01

Mast cells have been recognized for well over 100 years. With time, human mast cells have been documented to originate from CD34+ cells, and have been implicated in host responses in both innate and acquired immunity. In clinical immunology, they are recognized for their central role in IgE-mediated degranulation and allergic inflammation by virtue of their expression of the high-affinity receptor for IgE and release of potent proinflammatory mediators. In hematology, the clinical disease of mastocytosis is characterized by a pathologic increase of mast cells in tissues, often associated with mutations in KIT, the receptor for stem cell factor. More recently, and with increased understanding of how human mast cells are activated through receptors including the high-affinity receptor for IgE and KIT, specific tyrosine kinase inhibitors have been identified with the potential to interrupt signaling pathways and thus limit the proliferation of mast cells as well as their activation through immunoglobulin receptors. PMID:18684881

Targeted mutation analysis of endometrial clear cell carcinoma.

PubMed

Hoang, Lien N; McConechy, Melissa K; Meng, Bo; McIntyre, John B; Ewanowich, Carol; Gilks, Cyril Blake; Huntsman, David G; Köbel, Martin; Lee, Cheng-Han

2015-04-01

Endometrial clear cell carcinomas (CCC) constitute fewer than 5% of all carcinomas of the endometrium. Currently, little is known regarding the genetic basis of endometrial CCC. We performed genomic and immunohistochemical analyses on 14 rigorously reviewed pure endometrial CCC. The genomic analysis consisted of sequencing the coding regions of 26 genes implicated previously in endometrial carcinoma. Twelve of 14 tumours displayed a prototypical CCC immunophenotype [napsin A+, hepatocyte nuclear factor-1β (HNF1β(+) ) and oestrogen receptor(-) ] and all showed intact mismatch repair protein expression. We detected mutations in 11 of 14 tumours, and there was a predominance of mutations involving genes that are mutated more frequently in endometrial serous carcinomas than in endometrioid carcinomas. Two tumours displayed a prototypical serous carcinoma mutation profile (concurrent TP53 and PPP2R1A mutations, without PTEN, CTNNB1 or ARID1A mutation). No mutations in PTEN, CTNNB1 or POLE were identified. The overall mutation profile of this cohort of endometrial CCC appears to be more serous-like than endometrioid-like, with a minor subset in the TP53-mutated CCC showing serous carcinoma profile. These findings provide new insights into the molecular features of morphologically prototypical endometrial CCC, and underscore the need for further investigations into the oncogenesis of endometrial CCC. © 2014 John Wiley & Sons Ltd.

Potential ligand-binding residues in rat olfactory receptors identified by correlated mutation analysis

NASA Technical Reports Server (NTRS)

Singer, M. S.; Oliveira, L.; Vriend, G.; Shepherd, G. M.

1995-01-01

A family of G-protein-coupled receptors is believed to mediate the recognition of odor molecules. In order to identify potential ligand-binding residues, we have applied correlated mutation analysis to receptor sequences from the rat. This method identifies pairs of sequence positions where residues remain conserved or mutate in tandem, thereby suggesting structural or functional importance. The analysis supported molecular modeling studies in suggesting several residues in positions that were consistent with ligand-binding function. Two of these positions, dominated by histidine residues, may play important roles in ligand binding and could confer broad specificity to mammalian odor receptors. The presence of positive (overdominant) selection at some of the identified positions provides additional evidence for roles in ligand binding. Higher-order groups of correlated residues were also observed. Each group may interact with an individual ligand determinant, and combinations of these groups may provide a multi-dimensional mechanism for receptor diversity.

Role of the Transcription Factor Sox4 in Insulin Secretion and Impaired Glucose Tolerance

PubMed Central

Goldsworthy, Michelle; Hugill, Alison; Freeman, Helen; Horner, Emma; Shimomura, Kenju; Bogani, Debora; Pieles, Guido; Mijat, Vesna; Arkell, Ruth; Bhattacharya, Shoumo; Ashcroft, Frances M.; Cox, Roger D.

2008-01-01

OBJECTIVES— To identify, map, clone, and functionally validate a novel mouse model for impaired glucose tolerance and insulin secretion. RESEARCH DESIGN AND METHODS— Haploinsufficiency of the insulin receptor and associated mild insulin resistance has been used to sensitize an N-ethyl-N-nitrosourea (ENU) screen to identify novel mutations resulting in impaired glucose tolerance and diabetes. The new impaired glucose tolerance 4 (IGT4) model was selected using an intraperitoneal glucose tolerance test and inheritance of the phenotype confirmed by generation of backcross progeny. Segregation of the phenotype was correlated with genotype information to map the location of the gene and candidates sequenced for mutations. The function of the SRY-related high mobility group (HMG)-box 4 (Sox4) gene in insulin secretion was tested using another ENU allele and by small interfering RNA silencing in insulinoma cells. RESULTS— We describe two allelic autosomal dominant mutations in the highly conserved HMG box of the transcription factor Sox4. Previously associated with pancreas development, Sox4 mutations in the adult mouse result in an insulin secretory defect, which exhibits impaired glucose tolerance in association with insulin receptor+/−–induced insulin resistance. Elimination of the Sox4 transcript in INS1 and Min6 cells resulted in the abolition of glucose-stimulated insulin release similar to that observed for silencing of the key metabolic enzyme glucokinase. Intracellular calcium measurements in treated cells indicate that this defect lies downstream of the ATP-sensitive K+ channel (KATP channel) and calcium influx. CONCLUSIONS— IGT4 represents a novel digenic model of insulin resistance coupled with an insulin secretory defect. The Sox4 gene has a role in insulin secretion in the adult β-cell downstream of the KATP channel. PMID:18477811

Autosomal dominant anhidrotic ectodermal dysplasia with immunodeficiency caused by a novel NFKBIA mutation, p.Ser36Tyr, presents with mild ectodermal dysplasia and non-infectious systemic inflammation.

PubMed

Yoshioka, Takakazu; Nishikomori, Ryuta; Hara, Junichi; Okada, Keiko; Hashii, Yoshiko; Okafuji, Ikuo; Nodomi, Seishiro; Kawai, Tomoki; Izawa, Kazushi; Ohnishi, Hidenori; Yasumi, Takahiro; Nakahata, Tatsutoshi; Heike, Toshio

2013-10-01

Anhidrotic ectodermal dysplasia with immunodeficiency (EDA-ID) is characterized by hypohidrosis, dental abnormalities, sparse hair, and immunodeficiency. Autosomal dominant (AD)-EDA-ID, caused by a heterozygous mutation within NFKBIA, is very rare and its clinical features remain largely unknown. This study describes a patient with AD-EDA-ID harboring a novel NFKBIA mutation who presented with mild EDA and non-infectious systemic inflammation. The clinical presentation of an AD-EDA-ID patient was described and immunological, genetic, and biochemical analyses were performed, with a focus on nuclear factor kappa B (NF-κB) activation. The patient presented with symptoms of mild EDA-ID, namely sparse hair and hypohidrosis, although a skin biopsy confirmed the presence of sweat glands. There were no dental abnormalities. The patient also suffered from non-infectious inflammation, which responded to systemic corticosteroid therapy; however, the patient remained ill. Immunological analyses revealed reduced Toll-like receptor/IL-1 (TLR/IL-1) and tumor necrosis factor (TNF) receptor family responses to various stimuli. Genetic analysis identified a de novo heterozygous missense mutation, p.Ser36Tyr, in NFKBIA, resulting in defective NFKBIA degradation and impaired NF-κB activation. The patient was diagnosed with AD-EDA-ID and underwent hematopoietic stem cell transplantation. Engraftment was successful, with few signs of acute graft versus host disease. However, the patient suffered hemolytic anemia and thrombocytopenia, and died from a brain hemorrhage due to intractable thrombocytopenia. AD-EDA-ID patients can present with mild ectodermal dysplasia and non-infectious inflammation, rather than with recurrent infections. Also, hematopoietic stem cell transplantation for AD-EDA-ID is still a clinical challenge.

Pemetrexed Singlet Versus Nonpemetrexed-Based Platinum Doublet as Second-Line Chemotherapy after First-Line Epidermal Growth Factor Receptor (EGFR) Tyrosine Kinase Inhibitor Failure in Non-small Cell Lung Cancer Patients with EGFR Mutations.

PubMed

Park, Sehhoon; Keam, Bhumsuk; Kim, Se Hyun; Kim, Ki Hwan; Kim, Yu Jung; Kim, Jin-Soo; Kim, Tae Min; Lee, Se-Hoon; Kim, Dong-Wan; Lee, Jong Seok; Heo, Dae Seog

2015-10-01

Platinum-based doublet chemotherapy is the treatment of choice for patients with non-small cell lung cancer (NSCLC); however, the role of a platinum-based doublet as second-line therapy after failure of an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) for NSCLC patients has not yet been elucidated. The purpose of this study was to compare the clinical efficacy of pemetrexed versus a platinum-based doublet as second-line therapy after failure of EGFR TKI used as first-line therapy for NSCLC patients with EGFR mutations. We designed a multicenter retrospective cohort study of 314 NSCLC patients with EGFR mutations who received an EGFR TKI as first-line palliative chemotherapy. Our analysis included 83 patients who failed EGFR TKI therapy and received second-line cytotoxic chemotherapy. Forty-six patients were treated using a platinum-based doublet and 37 patients were treated using singlet pemetrexed. The overall response rates of patients receiving a platinum-based doublet and patients receiving pemetrexed were17.4% and 32.4%, respectively (p=0.111). The median progression-free survival (PFS) of patients receiving pemetrexed was significantly longer than that of patients receiving a platinum-based doublet (4.2 months vs. 2.7 months, respectively; p=0.008). The hazard ratio was 0.54 (95% confidence interval, 0.34 to 0.86; p=0.009). Our retrospective analysis found that second-line pemetrexed singlet therapy provided significantly prolonged PFS compared to second-line platinum-based doublet chemotherapy for NSCLC patients with EGFR mutations who failed first-line EGFR TKI. Conduct of prospective studies for confirmation of our results is warranted.

Review and update of mutations causing Waardenburg syndrome.

PubMed

Pingault, Véronique; Ente, Dorothée; Dastot-Le Moal, Florence; Goossens, Michel; Marlin, Sandrine; Bondurand, Nadège

2010-04-01

Waardenburg syndrome (WS) is characterized by the association of pigmentation abnormalities, including depigmented patches of the skin and hair, vivid blue eyes or heterochromia irides, and sensorineural hearing loss. However, other features such as dystopia canthorum, musculoskeletal abnormalities of the limbs, Hirschsprung disease, or neurological defects are found in subsets of patients and used for the clinical classification of WS. Six genes are involved in this syndrome: PAX3 (encoding the paired box 3 transcription factor), MITF (microphthalmia-associated transcription factor), EDN3 (endothelin 3), EDNRB (endothelin receptor type B), SOX10 (encoding the Sry bOX10 transcription factor), and SNAI2 (snail homolog 2), with different frequencies. In this review we provide an update on all WS genes and set up mutation databases, summarize molecular and functional data available for each of them, and discuss the applications in diagnostics and genetic counseling. (c) 2010 Wiley-Liss, Inc.

Marfan syndrome: current perspectives

PubMed Central

Pepe, Guglielmina; Giusti, Betti; Sticchi, Elena; Abbate, Rosanna; Gensini, Gian Franco; Nistri, Stefano

2016-01-01

Marfan syndrome (MFS) is a pleiotropic connective tissue disease inherited as an autosomal dominant trait, due to mutations in the FBN1 gene encoding fibrillin 1. It is an important protein of the extracellular matrix that contributes to the final structure of a microfibril. Few cases displaying an autosomal recessive transmission are reported in the world. The FBN1 gene, which is made of 66 exons, is located on chromosome 15q21.1. This review, after an introduction on the clinical manifestations that leads to the diagnosis of MFS, focuses on cardiovascular manifestations, pharmacological and surgical therapies of thoracic aortic aneurysm and/or dissection (TAAD), mechanisms underlying the progression of aneurysm or of acute dissection, and biomarkers associated with progression of TAADs. A Dutch group compared treatment with losartan, an angiotensin II receptor-1 blocker, vs no other additional treatment (COMPARE clinical trial). They observed that losartan reduces the aortic dilatation rate in patients with Marfan syndrome. Later on, they also reported that losartan exerts a beneficial effect on patients with Marfan syndrome carrying an FBN1 mutation that causes haploinsufficiency (quantitative mutation), while it has no significant effect on patients displaying dominant negative (qualitative) mutations. Moreover, a French group in a 3-year trial compared the administration of losartan vs placebo in patients with Marfan syndrome under treatment with beta-receptor blockers. They observed that losartan decreases blood pressure but has no effect on aortic diameter progression. Thus, beta-receptor blockers remain the gold standard therapy in patients with Marfan syndrome. Three potential biochemical markers are mentioned in this review: total homocysteine, serum transforming growth factor beta, and lysyl oxidase. Moreover, markers of oxidative stress measured in plasma, previously correlated with clinical features of Marfan syndrome, may be explored as potential biomarkers of clinical severity. PMID:27274304

Marfan syndrome: current perspectives.

PubMed

Pepe, Guglielmina; Giusti, Betti; Sticchi, Elena; Abbate, Rosanna; Gensini, Gian Franco; Nistri, Stefano

2016-01-01

Marfan syndrome (MFS) is a pleiotropic connective tissue disease inherited as an autosomal dominant trait, due to mutations in the FBN1 gene encoding fibrillin 1. It is an important protein of the extracellular matrix that contributes to the final structure of a microfibril. Few cases displaying an autosomal recessive transmission are reported in the world. The FBN1 gene, which is made of 66 exons, is located on chromosome 15q21.1. This review, after an introduction on the clinical manifestations that leads to the diagnosis of MFS, focuses on cardiovascular manifestations, pharmacological and surgical therapies of thoracic aortic aneurysm and/or dissection (TAAD), mechanisms underlying the progression of aneurysm or of acute dissection, and biomarkers associated with progression of TAADs. A Dutch group compared treatment with losartan, an angiotensin II receptor-1 blocker, vs no other additional treatment (COMPARE clinical trial). They observed that losartan reduces the aortic dilatation rate in patients with Marfan syndrome. Later on, they also reported that losartan exerts a beneficial effect on patients with Marfan syndrome carrying an FBN1 mutation that causes haploinsufficiency (quantitative mutation), while it has no significant effect on patients displaying dominant negative (qualitative) mutations. Moreover, a French group in a 3-year trial compared the administration of losartan vs placebo in patients with Marfan syndrome under treatment with beta-receptor blockers. They observed that losartan decreases blood pressure but has no effect on aortic diameter progression. Thus, beta-receptor blockers remain the gold standard therapy in patients with Marfan syndrome. Three potential biochemical markers are mentioned in this review: total homocysteine, serum transforming growth factor beta, and lysyl oxidase. Moreover, markers of oxidative stress measured in plasma, previously correlated with clinical features of Marfan syndrome, may be explored as potential biomarkers of clinical severity.

[Association of beta 3-adrenergic receptor gene with obesity in patients with type 2 diabetes mellitus].

PubMed

Chen, Y; Xu, Y; Zhou, L

2001-09-01

To investigate the association between the mutation of beta 3-adrenergoc receptor gene and obesity in patients with type 2 diabetes. Body mass, waist-hip ratio, blood pressure and blood lipids were measured in 154 type 2 diabetic patients. Polymerase chain reaction and the restriction fragment length polymorphism analysis were used to determine the wild, heterozygous and homozygous forms of beta 3-adrenergoc receptor gene. The frequency of the Trp64Arg mutation was 42.5% and the frequency of Arg64 allele was 22.6%. The mutation frequency of the genetic types was significantly different between the obese and non-obese type 2 diabetes mellitus patients. The body mass, systolic blood pressure, diastolic blood pressure, HDL-cholesterol were significantly different, when those with Trp64Arg heterozygous were compared with those with Trp64 homozygous. The genetic mutation of beta 3-adrenegoc receptor in patients with type 2 diabetes is probably related to obesity.

An Autoinflammatory Disease with Deficiency of the Interleukin-1–Receptor Antagonist

PubMed Central

Aksentijevich, Ivona; Masters, Seth L.; Ferguson, Polly J.; Dancey, Paul; Frenkel, Joost; van Royen-Kerkhoff, Annet; Laxer, Ron; Tedgård, Ulf; Cowen, Edward W.; Pham, Tuyet-Hang; Booty, Matthew; Estes, Jacob D.; Sandler, Netanya G.; Plass, Nicole; Stone, Deborah L.; Turner, Maria L.; Hill, Suvimol; Butman, John A.; Schneider, Rayfel; Babyn, Paul; El-Shanti, Hatem I.; Pope, Elena; Barron, Karyl; Bing, Xinyu; Laurence, Arian; Lee, Chyi-Chia R.; Chapelle, Dawn; Clarke, Gillian I.; Ohson, Kamal; Nicholson, Marc; Gadina, Massimo; Yang, Barbara; Korman, Benjamin D.; Gregersen, Peter K.; van Hagen, P. Martin; Hak, A. Elisabeth; Huizing, Marjan; Rahman, Proton; Douek, Daniel C.; Remmers, Elaine F.; Kastner, Daniel L.; Goldbach-Mansky, Raphaela

2010-01-01

Background Autoinflammatory diseases manifest inflammation without evidence of infection, high-titer autoantibodies, or autoreactive T cells. We report a disorder caused by mutations of IL1RN, which encodes the interleukin-1–receptor antagonist, with prominent involvement of skin and bone. Methods We studied nine children from six families who had neonatal onset of sterile multifocal osteomyelitis, periostitis, and pustulosis. Response to empirical treatment with the recombinant interleukin-1–receptor antagonist anakinra in the first patient prompted us to test for the presence of mutations and changes in proteins and their function in interleukin-1–pathway genes including IL1RN. Results We identified homozygous mutations of IL1RN in nine affected children, from one family from Newfoundland, Canada, three families from the Netherlands, and one consanguineous family from Lebanon. A nonconsanguineous patient from Puerto Rico was homozygous for a genomic deletion that includes IL1RN and five other interleukin-1–family members. At least three of the mutations are founder mutations; heterozygous carriers were asymptomatic, with no cytokine abnormalities in vitro. The IL1RN mutations resulted in a truncated protein that is not secreted, thereby rendering cells hyperresponsive to interleukin-1β stimulation. Patients treated with anakinra responded rapidly. Conclusions We propose the term deficiency of the interleukin-1–receptor antagonist, or DIRA, to denote this autosomal recessive autoinflammatory disease caused by mutations affecting IL1RN. The absence of interleukin-1–receptor antagonist allows unopposed action of interleukin-1, resulting in life-threatening systemic inflammation with skin and bone involvement. (ClinicalTrials.gov number, NCT00059748.) PMID:19494218

Mapping Interaction Sites on Human Chemokine Receptors by Deep Mutational Scanning.

PubMed

Heredia, Jeremiah D; Park, Jihye; Brubaker, Riley J; Szymanski, Steven K; Gill, Kevin S; Procko, Erik

2018-06-01

Chemokine receptors CXCR4 and CCR5 regulate WBC trafficking and are engaged by the HIV-1 envelope glycoprotein gp120 during infection. We combine a selection of human CXCR4 and CCR5 libraries comprising nearly all of ∼7000 single amino acid substitutions with deep sequencing to define sequence-activity landscapes for surface expression and ligand interactions. After consideration of sequence constraints for surface expression, known interaction sites with HIV-1-blocking Abs were appropriately identified as conserved residues following library sorting for Ab binding, validating the use of deep mutational scanning to map functional interaction sites in G protein-coupled receptors. Chemokine CXCL12 was found to interact with residues extending asymmetrically into the CXCR4 ligand-binding cavity, similar to the binding surface of CXCR4 recognized by an antagonistic viral chemokine previously observed crystallographically. CXCR4 mutations distal from the chemokine binding site were identified that enhance chemokine recognition. This included disruptive mutations in the G protein-coupling site that diminished calcium mobilization, as well as conservative mutations to a membrane-exposed site (CXCR4 residues H79 2.45 and W161 4.50 ) that increased ligand binding without loss of signaling. Compared with CXCR4-CXCL12 interactions, CCR5 residues conserved for gp120 (HIV-1 BaL strain) interactions map to a more expansive surface, mimicking how the cognate chemokine CCL5 makes contacts across the entire CCR5 binding cavity. Acidic substitutions in the CCR5 N terminus and extracellular loops enhanced gp120 binding. This study demonstrates how comprehensive mutational scanning can define functional interaction sites on receptors, and novel mutations that enhance receptor activities can be found simultaneously. Copyright © 2018 by The American Association of Immunologists, Inc.

Non-neural androgen receptors affect sexual differentiation of brain and behaviour.

PubMed

Monks, D A; Swift-Gallant, A

2018-02-01

Although gonadal testosterone is the principal endocrine factor that promotes masculine traits in mammals, the development of a male phenotype requires local production of both androgenic and oestrogenic signals within target tissues. Much of our knowledge concerning androgenic components of testosterone signalling in sexual differentiation comes from studies of androgen receptor (Ar) loss of function mutants. Here, we review these studies of loss of Ar function and of AR overexpression either globally or selectively in the nervous system of mice. Global and neural mutations affect socio-sexual behaviour and the neuroanatomy of these mice in a sexually differentiated manner. Some masculine traits are affected by both global and neural mutation, indicative of neural mediation, whereas other masculine traits are affected only by global mutation, indicative of an obligatory non-neural androgen target. These results support a model in which multiple sites of androgen action coordinate to produce masculine phenotypes. Furthermore, AR overexpression does not always have a phenotype opposite to that of loss of Ar function mutants, indicative of a nonlinear relationship between androgen dose and masculine phenotype in some cases. Potential mechanisms of Ar gene function in non-neural targets in producing masculine phenotypes are discussed. © 2017 British Society for Neuroendocrinology.

Inherited biallelic CSF3R mutations in severe congenital neutropenia.

PubMed

Triot, Alexa; Järvinen, Päivi M; Arostegui, Juan I; Murugan, Dhaarini; Kohistani, Naschla; Dapena Díaz, José Luis; Racek, Tomas; Puchałka, Jacek; Gertz, E Michael; Schäffer, Alejandro A; Kotlarz, Daniel; Pfeifer, Dietmar; Díaz de Heredia Rubio, Cristina; Ozdemir, Mehmet Akif; Patiroglu, Turkan; Karakukcu, Musa; Sánchez de Toledo Codina, José; Yagüe, Jordi; Touw, Ivo P; Unal, Ekrem; Klein, Christoph

2014-06-12

Severe congenital neutropenia (SCN) is characterized by low numbers of peripheral neutrophil granulocytes and a predisposition to life-threatening bacterial infections. We describe a novel genetic SCN type in 2 unrelated families associated with recessively inherited loss-of-function mutations in CSF3R, encoding the granulocyte colony-stimulating factor (G-CSF) receptor. Family A, with 3 affected children, carried a homozygous missense mutation (NM_000760.3:c.922C>T, NP_000751.1:p.Arg308Cys), which resulted in perturbed N-glycosylation and aberrant localization to the cell surface. Family B, with 1 affected infant, carried compound heterozygous deletions provoking frameshifts and premature stop codons (NM_000760.3:c.948_963del, NP_000751.1:p.Gly316fsTer322 and NM_000760.3:c.1245del, NP_000751.1:p.Gly415fsTer432). Despite peripheral SCN, all patients had morphologic evidence of full myeloid cell maturation in bone marrow. None of the patients responded to treatment with recombinant human G-CSF. Our study highlights the genetic and morphologic SCN variability and provides evidence both for functional importance and redundancy of G-CSF receptor-mediated signaling in human granulopoiesis. © 2014 by The American Society of Hematology.

Inherited biallelic CSF3R mutations in severe congenital neutropenia

PubMed Central

Triot, Alexa; Järvinen, Päivi M.; Arostegui, Juan I.; Murugan, Dhaarini; Kohistani, Naschla; Dapena Díaz, José Luis; Racek, Tomas; Puchałka, Jacek; Gertz, E. Michael; Schäffer, Alejandro A.; Kotlarz, Daniel; Pfeifer, Dietmar; Díaz de Heredia Rubio, Cristina; Ozdemir, Mehmet Akif; Patiroglu, Turkan; Karakukcu, Musa; Sánchez de Toledo Codina, José; Yagüe, Jordi; Touw, Ivo P.; Unal, Ekrem

2014-01-01

Severe congenital neutropenia (SCN) is characterized by low numbers of peripheral neutrophil granulocytes and a predisposition to life-threatening bacterial infections. We describe a novel genetic SCN type in 2 unrelated families associated with recessively inherited loss-of-function mutations in CSF3R, encoding the granulocyte colony-stimulating factor (G-CSF) receptor. Family A, with 3 affected children, carried a homozygous missense mutation (NM_000760.3:c.922C>T, NP_000751.1:p.Arg308Cys), which resulted in perturbed N-glycosylation and aberrant localization to the cell surface. Family B, with 1 affected infant, carried compound heterozygous deletions provoking frameshifts and premature stop codons (NM_000760.3:c.948_963del, NP_000751.1:p.Gly316fsTer322 and NM_000760.3:c.1245del, NP_000751.1:p.Gly415fsTer432). Despite peripheral SCN, all patients had morphologic evidence of full myeloid cell maturation in bone marrow. None of the patients responded to treatment with recombinant human G-CSF. Our study highlights the genetic and morphologic SCN variability and provides evidence both for functional importance and redundancy of G-CSF receptor-mediated signaling in human granulopoiesis. PMID:24753537

EGFR blockade enriches for lung cancer stem-like cells through Notch3-dependent signaling

PubMed Central

Arasada, Rajeswara Rao; Amann, Joseph M.; Rahman, Mohammad A; Huppert, Stacey S.; Carbone, David P.

2014-01-01

Mutations in the epidermal growth factor receptor (EGFR) are the most common actionable genetic abnormalities yet discovered in lung cancer. However, targeting these mutations with kinase inhibitors is not curative in advanced disease and has yet to demonstrate an impact on potentially curable, early-stage disease, with some data suggesting adverse outcomes. Here, we report that treatment of EGFR-mutated lung cancer cell lines with erlotinib, while showing robust cell death, enriches the ALDH+ stem-like cells through EGFR-dependent activation of Notch3. Additionally, we demonstrate that erlotinib treatment increases the clonogenicity of lung cancer cells in a sphere-forming assay, suggesting increased stem-like cell potential. We demonstrate that inhibition of EGFR kinase activity leads to activation of Notch transcriptional targets in a gamma secretase inhibitor sensitive manner and causes Notch activation. leading to an increase in ALDH high+ cells. We also find a kinase-dependent physical association between the Notch3 and EGFR receptors and tyrosine phosphorylation of Notch3. This could explain the worsened survival observed in some studies of erlotinib treatment at early-stage disease, and suggests that specific dual targeting might overcome this adverse effect. PMID:25125655

Osimertinib, a third-generation tyrosine kinase inhibitor targeting non-small cell lung cancer with EGFR T790M mutations.

PubMed

McCoach, C E; Jimeno, A

2016-10-01

Oncogenic driver mutations in the epidermal growth factor receptor (EGFR) gene have provided a focus for effective targeted therapy. Unfortunately, all patients eventually develop resistance to frontline therapy with EGFR tyrosine kinase inhibitors (TKIs). The majority of patients develop a large subclonal population of tumor cells with a T790M mutation that renders these cells resistant to first-generation TKIs. Osimertinib is a third-generation EGFR TKI that was designed to overcome resistance from T790M mutations. This agent has demonstrated strong preclinical activity, and in the clinic it has demonstrated a high objective response rate and progression-free survival in patients with EGFR double mutations (L858R/T790M and exon 19 deletion/T790M). It is now approved by the FDA for patients who have a documented T790M mutation and who have progressed on a prior TKI. Osimertinib is also approved in the E.U. and Japan. Copyright 2016 Prous Science, S.A.U. or its licensors. All rights reserved.

Heterogeneity of Clonal Expansion and Maturation-Linked Mutation Acquisition in Hematopoietic Progenitors in Human Acute Myeloid Leukemia

PubMed Central

Walter, Roland B.; Laszlo, George S.; Lionberger, Jack M.; Pollard, Jessica A.; Harrington, Kimberly H.; Gudgeon, Chelsea J.; Othus, Megan; Rafii, Shahin; Meshinchi, Soheil; Appelbaum, Frederick R.; Bernstein, Irwin D.

2014-01-01

Recent technological advances led to an appreciation of the genetic complexity of human acute myeloid leukemia (AML) but underlying progenitor cells remain poorly understood because their rarity precludes direct study. We developed a co-culture method integrating hypoxia, aryl hydrocarbon receptor inhibition, and micro-environmental support via human endothelial cells to isolate these cells. X-chromosome inactivation studies of the least mature precursors derived following prolonged culture of CD34+/CD33− cells revealed polyclonal growth in highly curable AMLs, suggesting mutations necessary for clonal expansion were acquired in more mature progenitors. Consistently, in core-binding factor (CBF) leukemias with known complementing mutations, immature precursors derived following prolonged culture of CD34+/CD33− cells harbored neither mutation or the CBF mutation alone, whereas more mature precursors often carried both mutations. These results were in contrast to those with leukemias with poor prognosis that showed clonal dominance in the least mature precursors. These data indicate heterogeneity among progenitors in human AML that may have prognostic and therapeutic implications. PMID:24721792

β-catenin contributes to lung tumor development induced by EGFR mutations

PubMed Central

Nakayama, Sohei; Sng, Natasha; Carretero, Julian; Welner, Robert; Hayashi, Yuichiro; Yamamoto, Mihoko; Tan, Alistair J.; Yamaguchi, Norihiro; Yasuda, Hiroyuki; Li, Danan; Soejima, Kenzo; Soo, Ross A.; Costa, Daniel B.; Wong, Kwok-Kin; Kobayashi, Susumu S.

2014-01-01

The discovery of somatic mutations in epidermal growth factor receptor (EGFR) and development of EGFR tyrosine kinase inhibitors (TKIs) have revolutionized treatment for lung cancer. However, resistance to TKIs emerges in almost all patients and currently no effective treatment is available. Here we show that β-catenin is essential for development of EGFR mutated lung cancers. β-catenin was upregulated and activated in EGFR mutated cells. Mutant EGFR preferentially bound to and tyrosine-phosphorylated β-catenin, leading to increase in β-catenin-mediated transactivation, particularly in cells harboring the gefitinib/erlotinib-resistant gatekeeper EGFR-T790M mutation. Pharmacological inhibition of β-catenin suppressed EGFR-L858R-T790M mutated lung tumor growth and genetic deletion of the β-catenin gene dramatically reduced lung tumor formation in EGFR-L858R-T790M transgenic mice. These data suggest that β-catenin plays an essential role in lung tumorigenesis and that targeting the β-catenin pathway may provide novel strategies to prevent lung cancer development or overcome resistance to EGFR TKIs. PMID:25164010

A novel mutation of the MITF gene in a family with Waardenburg syndrome type 2: A case report

PubMed Central

SHI, YUNFANG; LI, XIAOZHOU; JU, DUAN; LI, YAN; ZHANG, XIULING; ZHANG, YING

2016-01-01

Waardenburg syndrome (WS) is an autosomal dominant disorder with varying degrees of sensorineural hearing loss, and accumulation of pigmentation in hair, skin and iris. There are four types of WS (WS1–4) with differing characteristics. Mutations in six genes [paired box gene 3 (PAX3), microphthalmia-associated transcription factor (MITF), endothelin 3 (END3), endothelin receptor type B (EDNRB), SRY (sex determining region Y)-box 10 (SOX10) and snail homolog 2 (SNAI2)] have been identified to be associated with the various types. This case report describes the investigation of genetic mutations in three patients with WS2 from a single family. Genomic DNA was extracted, and the six WS-related genes were sequenced using next-generation sequencing technology. In addition to mutations in PAX3, EDNRB and SOX10, a novel heterozygous MITF mutation, p.Δ315Arg (c.944_946delGAA) on exon 8 was identified. This is predicted to be a candidate disease-causing mutation that may affect the structure and function of the enzyme. PMID:27073475

A novel mutation of the MITF gene in a family with Waardenburg syndrome type 2: A case report.

PubMed

Shi, Yunfang; Li, Xiaozhou; Ju, Duan; Li, Yan; Zhang, Xiuling; Zhang, Ying

2016-04-01

Waardenburg syndrome (WS) is an autosomal dominant disorder with varying degrees of sensorineural hearing loss, and accumulation of pigmentation in hair, skin and iris. There are four types of WS (WS1-4) with differing characteristics. Mutations in six genes [paired box gene 3 ( PAX3 ), microphthalmia-associated transcription factor ( MITF ), endothelin 3 ( END3 ), endothelin receptor type B ( EDNRB ), SRY (sex determining region Y)-box 10 ( SOX10 ) and snail homolog 2 ( SNAI2 )] have been identified to be associated with the various types. This case report describes the investigation of genetic mutations in three patients with WS2 from a single family. Genomic DNA was extracted, and the six WS-related genes were sequenced using next-generation sequencing technology. In addition to mutations in PAX3, EDNRB and SOX10, a novel heterozygous MITF mutation, p.Δ315Arg (c.944_946delGAA) on exon 8 was identified. This is predicted to be a candidate disease-causing mutation that may affect the structure and function of the enzyme.

The Thrombopoietin Receptor: Structural Basis of Traffic and Activation by Ligand, Mutations, Agonists, and Mutated Calreticulin.

PubMed

Varghese, Leila N; Defour, Jean-Philippe; Pecquet, Christian; Constantinescu, Stefan N

2017-01-01

A well-functioning hematopoietic system requires a certain robustness and flexibility to maintain appropriate quantities of functional mature blood cells, such as red blood cells and platelets. This review focuses on the cytokine receptor that plays a significant role in thrombopoiesis: the receptor for thrombopoietin (TPO-R; also known as MPL). Here, we survey the work to date to understand how this receptor functions at a molecular level throughout its lifecycle, from traffic to the cell surface, dimerization and binding cognate cytokine via its extracellular domain, through to its subsequent activation of associated Janus kinases and initiation of downstream signaling pathways, as well as the regulation of these processes. Atomic level resolution structures of TPO-R have remained elusive. The identification of disease-causing mutations in the receptor has, however, offered some insight into structure and function relationships, as has artificial means of receptor activation, through TPO mimetics, transmembrane-targeting receptor agonists, and engineering in dimerization domains. More recently, a novel activation mechanism was identified whereby mutated forms of calreticulin form complexes with TPO-R via its extracellular N-glycosylated domain. Such complexes traffic pathologically in the cell and persistently activate JAK2, downstream signal transducers and activators of transcription (STATs), and other pathways. This pathologic TPO-R activation is associated with a large fraction of human myeloproliferative neoplasms.

Osimertinib making a breakthrough in lung cancer targeted therapy

PubMed Central

Zhang, Haijun

2016-01-01

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) are the evidence-based first-line treatment for advanced non-small-cell lung cancer that harbors sensitizing EGFR mutations (EGFRm+) such as exon 19 deletions and L858R substitutions in exon 21. However, acquired resistance to EGFR TKIs is mostly driven by a second-site EGFR T790M mutation, which negates their inhibitory activity. Osimertinib (AZD9291, Tagrisso™), an oral, third-generation EGFR TKI, has been designed to target the EGFR T790M mutation, while sparing wild-type EGFR. In this up-to-date review, focus is not only on the structure, mechanisms, and pharmacokinetics of osimertinib but also on summarizing clinical trials and making recommendations of osimertinib for patients with non-small-cell lung cancer. PMID:27660466

Durable response to osimertinib in EGFR mutated T790M wildtype non-small cell lung cancer with leptomeningeal metastases: A case report.

PubMed

Chalmers, Anna; Jensen, Leif; Akerley, Wallace

2017-12-01

In patients with non-small cell lung cancer (NSCLC) progression with leptomeningeal (LM) metastases is a catastrophic event with limited treatment options. We report a patient who developed leptomeningeal disease while on front-line erlotinib. High-dose tyrosine kinase inhibitor was started but ineffective. She was transitioned to third-generation TKI osimertinib, despite lacking a T790M mutation, and responded with complete resolution of symptoms and malignant cytology in the cerebrospinal fluid (CSF). Recent phase one data and our case indicate osimertinib should be viewed as a best practice for treatment of LM disease in epidermal growth factor receptor (EGFR) mutated NSCLC regardless of T790M status. Copyright © 2017 Elsevier B.V. All rights reserved.

Novel CRLF1 gene mutation in a newborn infant diagnosed with Crisponi syndrome.

PubMed

Hakan, Nilay; Eminoglu, Fatma Tuba; Aydin, Mustafa; Zenciroglu, Aysegul; Karadag, Nazmiye Nilgun; Dursun, Arzu; Okumus, Nurullah; Ceylaner, Serdar

2012-12-01

Crisponi syndrome is an infrequently described disorder with autosomal recessive trait. It is characterized by extensive muscular contractions in the face after even minimal stimuli or crying, hypertonia, opisthotonus, camptodactyly, and typical facial features. Muscle contractions attenuate during rest or when the infant calms down. As a recently described new disease, Crisponi syndrome may be confused with epileptic manifestations. Most of the patients die in the first months of life due to hyperthermia and feeding problems. Recently, it has been demonstrated that mutations of the CRLF1 gene 'cytokine receptor-like factor 1' are associated with Crisponi syndrome. Here, we present a newborn diagnosed with Crisponi syndrome and report a novel homozygous CFRL1 gene mutation. © 2012 The Authors. Congenital Anomalies © 2012 Japanese Teratology Society.

The expression of SALL4 is significantly associated with EGFR, but not KRAS or EML4-ALK mutations in lung cancer.

PubMed

Jia, Xiangbo; Qian, Rulin; Zhang, Binbin; Zhao, Song

2016-10-01

Lung cancer is the leading cause of cancer-related deaths worldwide; unfortunately, its prognosis is still very poor. Therefore, developing the target molecular is very important for lung cancer diagnosis and treatment, especially in the early stage. With this in view, spalt-like transcription factor 4 ( SALL4 ) is considered a potential biomarker for diagnosis and prognosis in cancers, including lung cancer. In order to better investigate the association between the expression of SALL4 and driver genes mutation, 450 histopathologically diagnosed patients with lung cancer and 11 non-cancer patients were enrolled to test the expression of SALL4 and the status of driver genes mutation. This investigation included epidermal growth factor receptor ( EGFR ), kirsten rat sarcoma viral oncogene homolog ( KRAS ), and a fusion gene of the echinoderm microtubule-associated protein-like 4 ( EML4 ) and the anaplastic lymphoma kinase ( ALK ). The results of the study showed that females harbored more EGFR mutation in adenocarcinoma (ADC). The mutation rate of KRAS and EML4-ALK was about 5%, and the double mutations of EGFR/EML4-ALK were higher than EGFR/KRAS . In the expression analysis, the expression of SALL4 was much higher in cancer tissues than normally expected, especially in tissues that carried EGFR mutation (P<0.05), however, there were no significant differences between different mutation types. Likewise, there were no significant differences between expression of SALL4 and KRAS and EML4-ALK mutations. SALL4 is up regulated in lung cancer specimens and harbors EGFR mutation; this finding indicates that SALL4 expression may be relevant with EGFR , which could provide a new insight to lung cancer therapy. The mechanism needs further investigation and analysis.

Loss-of-function thrombospondin-1 mutations in familial pulmonary hypertension

PubMed Central

Stearman, Robert S.; Bull, Todd M.; Calabrese, David W.; Tripp-Addison, Megan L.; Wick, Marilee J.; Broeckel, Ulrich; Robbins, Ivan M.; Wheeler, Lisa A.; Cogan, Joy D.; Loyd, James E.

2012-01-01

Most patients with familial pulmonary arterial hypertension (FPAH) carry mutations in the bone morphogenic protein receptor 2 gene (BMPR2). Yet carriers have only a 20% risk of disease, suggesting that other factors influence penetrance. Thrombospondin-1 (TSP1) regulates activation of TGF-β and inhibits endothelial and smooth muscle cell proliferation, pathways coincidentally altered in pulmonary arterial hypertension (PAH). To determine whether a subset of FPAH patients also have mutations in the TSP1 gene (THBS1) we resequenced the type I repeats of THBS1 encoding the TGF-β regulation and cell growth inhibition domains in 60 FPAH probands, 70 nonfamilial PAH subjects, and in large control groups. We identified THBS1 mutations in three families: a novel missense mutation in two (Asp362Asn), and an intronic mutation in a third (IVS8+255 G/A). Neither mutation was detected in population controls. Mutant 362Asn TSP1 had less than half of the ability of wild-type TSP1 to activate TGF-β. Mutant 362Asn TSP1 also lost the ability to inhibit growth of pulmonary arterial smooth muscle cells and was over threefold less effective at inhibiting endothelial cell growth. The IVS8+255 G/A mutation decreased and/or eliminated local binding of the transcription factors SP1 and MAZ but did not affect RNA splicing. These novel mutations implicate THBS1 as a modifier gene in FPAH. These THBS1 mutations have implications in the genetic evaluation of FPAH patients. However, since FPAH is rare, these data are most relevant as evidence for the importance of TSP1 in pulmonary vascular homeostasis. Further examination of THBS1 in the pathogenesis of PAH is warranted. PMID:22198906

The association of TP53 mutations with the resistance of colorectal carcinoma to the insulin-like growth factor-1 receptor inhibitor picropodophyllin

PubMed Central

2013-01-01

Background There is growing evidence indicating the insulin-like growth factor 1 receptor (IGF-1R) plays a critical role in the progression of human colorectal carcinomas. IGF-1R is an attractive drug target for the treatment of colon cancer. Picropodophyllin (PPP), of the cyclolignan family, has recently been identified as an IGF-1R inhibitor. The aim of this study is to determine the therapeutic response and mechanism after colorectal carcinoma treatment with PPP. Methods Seven colorectal carcinoma cell lines were treated with PPP. Following treatment, cells were analyzed for growth by a cell viability assay, sub-G1 apoptosis by flow cytometry, caspase cleavage and activation of AKT and extracellular signal-regulated kinase (ERK) by western blot analysis. To examine the in vivo therapeutic efficacy of PPP, mice implanted with human colorectal carcinoma xenografts underwent PPP treatment. Results PPP treatment blocked the phosphorylation of IGF-1R, AKT and ERK and inhibited the growth of TP53 wild-type but not mutated colorectal carcinoma cell lines. The treatment of PPP also induced apoptosis in TP53 wild-type cells as evident by the presence of sub-G1 cells and the cleavage of caspase-9, caspase-3, DNA fragmentation factor-45 (DFF45), poly (ADP-ribose) polymerase (PARP), and X-linked inhibitor of apoptosis protein (XIAP). The loss of BAD phosphorylation in the PPP-treated TP53 wild type cells further suggested that the treatment induced apoptosis through the BAD-mediated mitochondrial pathway. In contrast, PPP treatment failed to induce the phosphorylation of AKT and ERK and caspase cleavage in TP53 mutated colorectal carcinoma cell lines. Finally, PPP treatment suppressed the growth of xenografts derived from TP53 wild type but not mutated colorectal carcinoma cells. Conclusions We report the association of TP53 mutations with the resistance of treatment of colorectal carcinoma cells in culture and in a xenograft mouse model with the IGF-1R inhibitor PPP. TP53 mutations often occur in colorectal carcinomas and could be used as a biomarker to predict the resistance of colorectal carcinomas to the treatment by this IGF-1R inhibitor. PMID:24182354

Mechanisms for the Evolution of a Derived Function in the Ancestral Glucocorticoid Receptor

PubMed Central

Carroll, Sean Michael; Ortlund, Eric A.; Thornton, Joseph W.

2011-01-01

Understanding the genetic, structural, and biophysical mechanisms that caused protein functions to evolve is a central goal of molecular evolutionary studies. Ancestral sequence reconstruction (ASR) offers an experimental approach to these questions. Here we use ASR to shed light on the earliest functions and evolution of the glucocorticoid receptor (GR), a steroid-activated transcription factor that plays a key role in the regulation of vertebrate physiology. Prior work showed that GR and its paralog, the mineralocorticoid receptor (MR), duplicated from a common ancestor roughly 450 million years ago; the ancestral functions were largely conserved in the MR lineage, but the functions of GRs—reduced sensitivity to all hormones and increased selectivity for glucocorticoids—are derived. Although the mechanisms for the evolution of glucocorticoid specificity have been identified, how reduced sensitivity evolved has not yet been studied. Here we report on the reconstruction of the deepest ancestor in the GR lineage (AncGR1) and demonstrate that GR's reduced sensitivity evolved before the acquisition of restricted hormone specificity, shortly after the GR–MR split. Using site-directed mutagenesis, X-ray crystallography, and computational analyses of protein stability to recapitulate and determine the effects of historical mutations, we show that AncGR1's reduced ligand sensitivity evolved primarily due to three key substitutions. Two large-effect mutations weakened hydrogen bonds and van der Waals interactions within the ancestral protein, reducing its stability. The degenerative effect of these two mutations is extremely strong, but a third permissive substitution, which has no apparent effect on function in the ancestral background and is likely to have occurred first, buffered the effects of the destabilizing mutations. Taken together, our results highlight the potentially creative role of substitutions that partially degrade protein structure and function and reinforce the importance of permissive mutations in protein evolution. PMID:21698144

Mechanisms for the Evolution of a Derived Function in the Ancestral Glucocorticoid Receptor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carroll, Sean Michael; Ortlund, Eric A; Thornton, Joseph W.

2012-03-16

Understanding the genetic, structural, and biophysical mechanisms that caused protein functions to evolve is a central goal of molecular evolutionary studies. Ancestral sequence reconstruction (ASR) offers an experimental approach to these questions. Here we use ASR to shed light on the earliest functions and evolution of the glucocorticoid receptor (GR), a steroid-activated transcription factor that plays a key role in the regulation of vertebrate physiology. Prior work showed that GR and its paralog, the mineralocorticoid receptor (MR), duplicated from a common ancestor roughly 450 million years ago; the ancestral functions were largely conserved in the MR lineage, but the functionsmore » of GRs - reduced sensitivity to all hormones and increased selectivity for glucocorticoids - are derived. Although the mechanisms for the evolution of glucocorticoid specificity have been identified, how reduced sensitivity evolved has not yet been studied. Here we report on the reconstruction of the deepest ancestor in the GR lineage (AncGR1) and demonstrate that GR's reduced sensitivity evolved before the acquisition of restricted hormone specificity, shortly after the GR-MR split. Using site-directed mutagenesis, X-ray crystallography, and computational analyses of protein stability to recapitulate and determine the effects of historical mutations, we show that AncGR1's reduced ligand sensitivity evolved primarily due to three key substitutions. Two large-effect mutations weakened hydrogen bonds and van der Waals interactions within the ancestral protein, reducing its stability. The degenerative effect of these two mutations is extremely strong, but a third permissive substitution, which has no apparent effect on function in the ancestral background and is likely to have occurred first, buffered the effects of the destabilizing mutations. Taken together, our results highlight the potentially creative role of substitutions that partially degrade protein structure and function and reinforce the importance of permissive mutations in protein evolution.« less

GTG mutation in the start codon of the androgen receptor gene in a family of horses with 64,XY disorder of sex development.

PubMed

Révay, T; Villagómez, D A F; Brewer, D; Chenier, T; King, W A

2012-01-01

Genetic sex in mammals is determined by the sex chromosomal composition of the zygote. The X and Y chromosomes are responsible for numerous factors that must work in close concert for the proper development of a healthy sexual phenotype. The role of androgens in case of XY chromosomal constitution is crucial for normal male sex differentiation. The intracellular androgenic action is mediated by the androgen receptor (AR), and its impaired function leads to a myriad of syndromes with severe clinical consequences, most notably androgen insensitivity syndrome and prostate cancer. In this paper, we investigated the possibility that an alteration of the equine AR gene explains a recently described familial XY, SRY + disorder of sex development. We uncovered a transition in the first nucleotide of the AR start codon (c.1A>G). To our knowledge, this represents the first causative AR mutation described in domestic animals. It is also a rarely observed mutation in eukaryotes and is unique among the >750 entries of the human androgen receptor mutation database. In addition, we found another quiet missense mutation in exon 1 (c.322C>T). Transcription of AR was confirmed by RT-PCR amplification of several exons. Translation of the full-length AR protein from the initiating GTG start codon was confirmed by Western blot using N- and C-terminal-specific antibodies. Two smaller peptides (25 and 14 amino acids long) were identified from the middle of exon 1 and across exons 5 and 6 by mass spectrometry. Based upon our experimental data and the supporting literature, it appears that the AR is expressed as a full-length protein and in a functional form, and the observed phenotype is the result of reduced AR protein expression levels. Copyright © 2011 S. Karger AG, Basel.

Effects of icotinib on advanced non-small cell lung cancer with different EGFR phenotypes.

PubMed

Pan, Huiyun; Liu, Rong; Li, Shengjie; Fang, Hui; Wang, Ziwei; Huang, Sheng; Zhou, Jianying

2014-09-01

Icotinib is the first oral epidermal growth factor receptor (EGFR) tyrosine kinase receptor inhibitor, which has been proven to exert significant inhibitory effects on non-small cell lung cancer in vitro. Clinical evidence has showed that the efficacy of Icotinib on retreating advanced non-small cell lung cancer is comparable to Gefitinib. However, different phenotypes of EGFR can affect the therapeutic outcomes of EGFR tyrosine kinase receptor inhibitor. Therefore, our study focused on efficacy and safety of Icotinib in patients with advanced non-small cell lung cancer of different EGPR phenotypes. Clinical data of patients with advanced non-small cell lung cancer who received Icotinib treatment from August, 2011 to May, 2013 were retrospectively analyzed. Kaplan-Meier analysis was used for survival analysis and comparison. 18 wild-type EGFR and 51 mutant type were found in a total of 69 patients. Objective response rate of patients with mutant type EGFR was 54.9 % and disease control rate was 86.3 %. Objective response rate of wild-type patients was 11.1 % (P = 0.0013 vs mutant type), disease control rate was 50.0 % (P = 0.0017). Median progression-free survival (PFS) of mutant type and wild-type patients were 9.7 and 2.6 months, respectively (P < 0.001). Median PFS of exon 19 mutated mutant patients was 11.3 months, mean PFS of exon 21 L858R mutated mutant patients was 8.7 months (P = 0.3145). Median overall survival (OS) of EGFR mutated patients had not reached. OS time of 13 wild-type patients was 12.9 months (P < 0.001). The common adverse reactions of Icotinib included rash, diarrhea, itching skin with occurrence rates of 24.6 % (17/69), 13.0 % (9/69), and 11.6 % (8/69), respectively. Most adverse reactions were grade I-II. Icotinib has great efficacy in EGFR mutated patients, making it an optimal regimen to treat EGFR mutated patients. Furthermore, most of adverse reactions associated with Icotinib treatment were tolerable.

The androgen receptor gene mutations database.

PubMed

Gottlieb, B; Trifiro, M; Lumbroso, R; Vasiliou, D M; Pinsky, L

1996-01-01

The current version of the androgen receptor (AR) gene mutations database is described. We have added (if available) data on the androgen binding phenotype of the mutant AR, the clinical phenotype of the affected persons, the family history and whether the pathogenicity of a mutation has been proven. Exonic mutations are now listed in 5'-->3' sequence regardless of type and single base pair changes are presented in codon context. Splice site and intronic mutations are listed separately. The database has allowed us to substantiate and amplify the observation of mutational hot spots within exons encoding the AR androgen binding domain. The database is available from EML (ftp://www.ebi.ac.uk/pub/databases/androgen) or as a Macintosh Filemaker file (MC33@musica.mcgill.ca).

Differential effects of FGFR2 mutations on syndactyly and cleft palate in Apert syndrome

DOE Office of Scientific and Technical Information (OSTI.GOV)

Slaney, S.F.; Oldridge, M.; Wilkie, A.O.M.

1996-05-01

Apert syndrome is a distinctive human malformation characterized by craniosynostosis and severe syndactyly of the hands and feet. It is caused by specific missense substitutions involving adjacent amino acids (Ser252Trp or Pro253Arg) in the linker between the second and third extracellular immunoglobulin domains of fibroblast growth factor receptor 2 (FGFR2). We have developed a simple PCR assay for these mutations in genomic DNA, based on the creation of novel SfiI and BstUI restriction sites. Analysis of DNA from 70 unrelated patients with Apert syndrome showed that 45 had the Ser252Trp mutation and 25 had the Pro253Arg mutation. Phenotypic differences betweenmore » these two groups of patients were investigated. Significant differences were found for severity of syndactyly and presence of cleft palate. The syndactyly was more severe with the Pro253Arg mutation, for both the hands and the feet. In contrast, cleft palate was significantly more common in the Ser252Trp patients. No convincing differences were found in the prevalence of other malformations associated with Apert syndrome. We conclude that, although the phenotype attributable to the two mutations is very similar, there are subtle differences. The opposite trends for severity of syndactyly and cleft palate in relation to the two mutations may relate to the varying patterns of temporal and tissue-specific expression of different fibroblast growth factors, the ligands for FGFR2. 54 refs., 5 figs., 3 tabs.« less

Deep Sequencing-guided Design of a High Affinity Dual Specificity Antibody to Target Two Angiogenic Factors in Neovascular Age-related Macular Degeneration.

PubMed

Koenig, Patrick; Lee, Chingwei V; Sanowar, Sarah; Wu, Ping; Stinson, Jeremy; Harris, Seth F; Fuh, Germaine

2015-09-04

The development of dual targeting antibodies promises therapies with improved efficacy over mono-specific antibodies. Here, we engineered a Two-in-One VEGF/angiopoietin 2 antibody with dual action Fab (DAF) as a potential therapeutic for neovascular age-related macular degeneration. Crystal structures of the VEGF/angiopoietin 2 DAF in complex with its two antigens showed highly overlapping binding sites. To achieve sufficient affinity of the DAF to block both angiogenic factors, we turned to deep mutational scanning in the complementarity determining regions (CDRs). By mutating all three CDRs of each antibody chain simultaneously, we were able not only to identify affinity improving single mutations but also mutation pairs from different CDRs that synergistically improve both binding functions. Furthermore, insights into the cooperativity between mutations allowed us to identify fold-stabilizing mutations in the CDRs. The data obtained from deep mutational scanning reveal that the majority of the 52 CDR residues are utilized differently for the two antigen binding function and permit, for the first time, the engineering of several DAF variants with sub-nanomolar affinity against two structurally unrelated antigens. The improved variants show similar blocking activity of receptor binding as the high affinity mono-specific antibodies against these two proteins, demonstrating the feasibility of generating a dual specificity binding surface with comparable properties to individual high affinity mono-specific antibodies. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Osimertinib in patients with epidermal growth factor receptor T790M advanced non-small cell lung cancer selected using cytology samples.

PubMed

Kiura, Katsuyuki; Yoh, Kiyotaka; Katakami, Nobuyuki; Nogami, Naoyuki; Kasahara, Kazuo; Takahashi, Toshiaki; Okamoto, Isamu; Cantarini, Mireille; Hodge, Rachel; Uchida, Hirohiko

2018-04-01

Osimertinib is a potent, irreversible epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) selective for EGFR-TKI sensitizing (EGFRm) and T790M resistance mutations. The primary objective of the cytology cohort in the AURA study was to investigate safety and efficacy of osimertinib in pretreated Japanese patients with EGFR T790M mutation-positive non-small cell lung cancer (NSCLC), with screening EGFR T790M mutation status determined from cytology samples. The cytology cohort was included in the Phase I dose expansion component of the AURA study. Patients were enrolled based on a positive result of T790M by using cytology samples, and received osimertinib 80 mg in tablet form once daily until disease progression or until clinical benefit was no longer observed at the discretion of the investigator. Primary endpoint for efficacy was objective response rate (ORR) by investigator assessment. Twenty-eight Japanese patients were enrolled into the cytology cohort. At data cut-off (February 1, 2016), 12 (43%) were on treatment. Investigator-assessed ORR was 75% (95% confidence interval [CI] 55, 89) and median duration of response was 9.7 months (95% CI 3.8, not calculable [NC]). Median progression-free survival was 8.3 months (95% CI 4.2, NC) and disease control rate was 96% (95% CI 82, 100). The most common all-causality adverse events were paronychia (46%), dry skin (46%), diarrhea (36%) and rash (36%). Osimertinib provided clinical benefit with a manageable safety profile in patients with pretreated EGFR T790M mutation-positive NSCLC whose screening EGFR T790M mutation-positive status was determined from cytology samples. (ClinicalTrials.gov number NCT01802632). © 2018 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.

Acquired resistance to an epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) in an uncommon G719S EGFR mutation.

PubMed

Osoegawa, Atsushi; Hashimoto, Takafumi; Takumi, Yohei; Abe, Miyuki; Yamada, Tomonori; Kobayashi, Ryoji; Miyawaki, Michiyo; Takeuchi, Hideya; Okamoto, Tatsuro; Sugio, Kenji

2018-03-28

Background Acquired resistance (AR) to an epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) is a common event, and several underlying mechanisms, including T790 M, MET amplification and PTEN downregulation, have been reported for the common EGFR mutations. EGFR G719X is an uncommon mutation that has been reported to show sensitivity to EGFR-TKIs. However, no established cell lines harboring the EGFR G719X have been reported in the literature. Materials and Methods G719S-GR cells were established from malignant pleural effusion of a patient whose tumor developed AR from gefitinib treatment. G719S-GR cells were then genotyped and tested for drug sensitivities. Multiplex ligation-dependent probe amplification (MLPA) was used to compare the clinical tumor samples with G719S-GR. Results G719S-GR cells were resistant to EGFR-TKIs with an LC50 of around 10 μM. A genomic analysis showed that G719S-GR cells harbor the EGFR G719S mutation as well as the amplification of EGFR locus. The homozygous deletion of CDKN2A and the loss of PTEN and TSC1 were also detected. On comparing the copy number of tumor suppressor genes using MLPA, G719S-GR cells were found to lack one copy of PTEN, which was not observed in a tumor obtained before gefitinib treatment. Loss of PTEN may result in AKT activation. The mTORC1/2 inhibitor Torin-1 was able to inhibit the downstream signaling when combined with osimertinib. Discussion The newly established G719S-GR cell line may be useful for investigating the mechanism underlying the development of AR in the G719X mutation; the loss of PTEN may be one such mechanism.

Role of race in oncogenic driver prevalence and outcomes in lung adenocarcinoma: Results from the Lung Cancer Mutation Consortium.

PubMed

Steuer, Conor E; Behera, Madhusmita; Berry, Lynne; Kim, Sungjin; Rossi, Michael; Sica, Gabriel; Owonikoko, Taofeek K; Johnson, Bruce E; Kris, Mark G; Bunn, Paul A; Khuri, Fadlo R; Garon, Edward B; Ramalingam, Suresh S

2016-03-01

The discovery of oncogenic drivers has ushered in a new era for lung cancer, but the role of these mutations in different racial/ethnic minorities has been understudied. The Lung Cancer Mutation Consortium 1 (LCMC1) database was investigated to evaluate the frequency and impact of oncogenic drivers in lung adenocarcinomas in the racial/ethnic minority patient population. Patients with metastatic lung adenocarcinomas from 14 US sites were enrolled in the LCMC1. Tumor samples were collected from 2009 through 2012 with multiplex genotyping performed on 10 oncogenic drivers (KRAS, epidermal growth factor receptor [EGFR], anaplastic lymphoma kinase (ALK) rearrangements, ERBB2 [formerly human epidermal growth factor receptor 2], BRAF, PIK3CA, MET amplification, NRAS, MEK1, and AKT1). Patients were classified as white, Asian, African American (AA), or Latino. The driver mutation frequency, the treatments, and the survival from diagnosis were determined. One thousand seven patients were included. Whites represented the majority (n = 838); there were 60 AAs, 48 Asians, and 28 Latinos. Asian patients had the highest rate of oncogenic drivers with 81% (n = 39), and they were followed by Latinos with 68% (n = 19), whites with 61% (n = 511), and AAs with 53% (n = 32). For AAs, the EGFR mutation frequency was 22%, the KRAS frequency was 17%, and the ALK frequency was 4%. Asian patients were most likely to receive targeted therapies (51% vs 27% for AAs). There were no significant differences in overall survival. Differences were observed in the prevalence of oncogenic drivers in lung adenocarcinomas and in subsequent treatments among racial groups. The lowest frequency of drivers was seen for AA patients; however, more than half of AA patients had a driver, and those treated with targeted therapy had outcomes similar to those of other races. Cancer 2016;122:766-772. © 2015 American Cancer Society. © 2015 American Cancer Society.

Novel targeted approaches to treating biliary tract cancer: the dual epidermal growth factor receptor and ErbB-2 tyrosine kinase inhibitor NVP-AEE788 is more efficient than the epidermal growth factor receptor inhibitors gefitinib and erlotinib.

PubMed

Wiedmann, Marcus; Feisthammel, Jürgen; Blüthner, Thilo; Tannapfel, Andrea; Kamenz, Thomas; Kluge, Annett; Mössner, Joachim; Caca, Karel

2006-08-01

Aberrant activation of the epidermal growth factor receptor is frequently observed in neoplasia, notably in tumors of epithelial origin. Attempts to treat such tumors with epidermal growth factor receptor antagonists resulted in remarkable success in recent studies. Little is known, however, about the efficacy of this therapy in biliary tract cancer. Protein expression of epidermal growth factor receptor, ErbB-2, and vascular endothelial growth factor receptor-2 was assessed in seven human biliary tract cancer cell lines by immunoblotting. In addition, histological sections from 19 patients with extrahepatic cholangiocarcinoma were analyzed for epidermal growth factor receptor, ErbB-2 and vascular endothelial growth factor receptor-2 expression by immunohistochemistry. Moreover, we sequenced the cDNA products representing the entire epidermal growth factor receptor coding region of the seven cell lines, and searched for genomic epidermal growth factor receptor amplifications and polysomy by fluorescence in-situ hybridization. Cell growth inhibition by gefitinib erlotinib and NVP-AEE788 was studied in vitro by automated cell counting. In addition, the anti-tumoral effect of erlotinib and NVP-AEE788 was studied in a chimeric mouse model. The anti-tumoral drug mechanism in this model was assessed by MIB-1 antibody staining, terminal deoxynucleotidyl transfer-mediated dUTP nick end-labelling assay, von Willebrand factor staining, and immunoblotting for p-p42/44 (p-Erk1/2, p-MAPK) and p-AKT. Immunoblotting revealed expression of epidermal growth factor receptor, ErbB-2, and vascular endothelial growth factor receptor-2 in all biliary tract cancer cell lines. EGFR was detectable in six of 19 (32%) extrahepatic human cholangiocarcinoma tissue samples, ErbB-2 in 16 of 19 (84%), and vascular endothelial growth factor receptor-2 in nine of 19 (47%). Neither epidermal growth factor receptor mutations nor amplifications or polysomy were found in the seven biliary tract cancer cell lines. Gefitinib, erlotinib and NVP-AEE788 caused a significant growth inhibition in vitro; however, there was a significant difference in efficacy (NVP-AEE788>erlotinib>gefitinib). After 14 days of in-vivo treatment, using the chimeric mouse model, tumors had a significantly reduced volume and mass after NVP-AEE788, but not after erlotinib treatment, as compared with placebo. Reduction of proliferation (signalling via the mitogen-activated protein kinase pathway), induction of apoptosis and inhibition of angiogenesis were the main mechanisms of drug action. No significant reduction of anti-apoptotic AKT phosphorylation, however, occurred, which may be a possible counter mechanism of the tumor. Epidermal growth factor receptor, ErbB-2, and vascular endothelial growth factor receptor-2 expression was detectable in biliary tract cancer, and receptor inhibition exerts marked effects on tumor growth in vitro and in vivo, which was strongest for the dual EGFR/ErbB-2 inhibitor NVP-AEE788. Therefore, further clinical evaluation of this new drug for the treatment of biliary tract cancer is recommended.

Mig6 Puts the Brakes on Mutant EGFR-Driven Lung Cancer | Center for Cancer Research

Cancer.gov

Lung cancer is the most common cause of cancer-related death worldwide. These cancers are often induced by mutations in the epidermal growth factor receptor (EGFR), resulting in constitutive activation of the protein’s tyrosine kinase domain. Lung cancers expressing these EGFR mutants are initially sensitive to tyrosine kinase inhibitors (TKIs), such as erlotinib, but often

Uncovering the Origin of Skin Side Effects from EGFR-Targeted Therapies | Center for Cancer Research

Cancer.gov

The epidermal growth factor receptor (EGFR), a key regulator of cell proliferation, is often mutated or overexpressed in a variety of cancer types. EGFR-targeted therapies, including monoclonal antibodies and small molecule inhibitors, can effectively treat patients whose tumors depend on aberrant EGFR signaling. Within a few weeks of initiating therapy, however, patients

Investigating the effect of key mutations on the conformational dynamics of toll-like receptor dimers through molecular dynamics simulations and protein structure networks.

PubMed

Mahita, Jarjapu; Sowdhamini, Ramanathan

2018-04-01

The Toll-like receptors (TLRs) are critical components of the innate immune system due to their ability to detect conserved pathogen-associated molecular patterns, present in bacteria, viruses, and other microorganisms. Ligand detection by TLRs leads to a signaling cascade, mediated by interactions among TIR domains present in the receptors, the bridging adaptors and sorting adaptors. The BB loop is a highly conserved region present in the TIR domain and is crucial for mediating interactions among TIR domain-containing proteins. Mutations in the BB loop of the Toll-like receptors, such as the A795P mutation in TLR3 and the P712H mutation (Lps d mutation) in TLR4, have been reported to disrupt or alter downstream signaling. While the phenotypic effect of these mutations is known, the underlying effect of these mutations on the structure, dynamics and interactions with other TIR domain-containing proteins is not well understood. Here, we have attempted to investigate the effect of the BB loop mutations on the dimer form of TLRs, using TLR2 and TLR3 as case studies. Our results based on molecular dynamics simulations, protein-protein interaction analyses and protein structure network analyses highlight significant differences between the dimer interfaces of the wild-type and mutant forms and provide a logical reasoning for the effect of these mutations on adaptor binding to TLRs. Furthermore, it also leads us to propose a hypothesis for the differential requirement of signaling and bridging adaptors by TLRs. This could aid in further understanding of the mechanisms governing such signaling pathways. © 2018 Wiley Periodicals, Inc.

Epidermal growth factor receptor and K-Ras in non-small cell lung cancer-molecular pathways involved and targeted therapies

PubMed Central

de Mello, Ramon Andrade; Marques, Dânia Sofia; Medeiros, Rui; Araújo, António MF

2011-01-01

Lung cancer is currently the leading cause of cancer death in Western nations. Non-small cell lung cancer (NSCLC) represents 80% of all lung cancers, and adenocarcinoma is the predominant histological type. Despite the intensive research carried out on this field and therapeutic advances, the overall prognosis of these patients remains unsatisfactory, with a 5-year overall survival rate of less than 15%. Nowadays, pharmacogenetics and pharmacogenomics represent the key to successful treatment. Recent studies suggest the existence of two distinct molecular pathways in the carcinogenesis of lung adenocarcinoma: one associated with smoking and activation of the K-Ras oncogene and the other not associated with smoking and activation of the epidermal growth factor receptor (EGFR). The K-ras mutation is mainly responsible for primary resistance to new molecules which inhibit tyrosine kinase EGFR (erlotinib and gefitinib) and most of the EGFR mutations are responsible for increased tumor sensitivity to these drugs. This article aims to conduct a systematic review of the literature regarding the molecular pathways involving the EGFR, K-Ras and EGFR targeted therapies in NSCLC tumor behavior. PMID:22087435

Patient-derived models of acquired resistance can identify effective drug combinations for cancer.

PubMed

Crystal, Adam S; Shaw, Alice T; Sequist, Lecia V; Friboulet, Luc; Niederst, Matthew J; Lockerman, Elizabeth L; Frias, Rosa L; Gainor, Justin F; Amzallag, Arnaud; Greninger, Patricia; Lee, Dana; Kalsy, Anuj; Gomez-Caraballo, Maria; Elamine, Leila; Howe, Emily; Hur, Wooyoung; Lifshits, Eugene; Robinson, Hayley E; Katayama, Ryohei; Faber, Anthony C; Awad, Mark M; Ramaswamy, Sridhar; Mino-Kenudson, Mari; Iafrate, A John; Benes, Cyril H; Engelman, Jeffrey A

2014-12-19

Targeted cancer therapies have produced substantial clinical responses, but most tumors develop resistance to these drugs. Here, we describe a pharmacogenomic platform that facilitates rapid discovery of drug combinations that can overcome resistance. We established cell culture models derived from biopsy samples of lung cancer patients whose disease had progressed while on treatment with epidermal growth factor receptor (EGFR) or anaplastic lymphoma kinase (ALK) tyrosine kinase inhibitors and then subjected these cells to genetic analyses and a pharmacological screen. Multiple effective drug combinations were identified. For example, the combination of ALK and MAPK kinase (MEK) inhibitors was active in an ALK-positive resistant tumor that had developed a MAP2K1 activating mutation, and the combination of EGFR and fibroblast growth factor receptor (FGFR) inhibitors was active in an EGFR mutant resistant cancer with a mutation in FGFR3. Combined ALK and SRC (pp60c-src) inhibition was effective in several ALK-driven patient-derived models, a result not predicted by genetic analysis alone. With further refinements, this strategy could help direct therapeutic choices for individual patients. Copyright © 2014, American Association for the Advancement of Science.

Incorporating BEAMing technology as a liquid biopsy into clinical practice for the management of colorectal cancer patients: an expert taskforce review.

PubMed

García-Foncillas, J; Alba, E; Aranda, E; Díaz-Rubio, E; López-López, R; Tabernero, J; Vivancos, A

2017-12-01

The importance of mutation identification for advanced colorectal cancer treatment with anti-epidermal growth factor receptor agents is well established. However, due to delays in turnaround time, low-quality tissue samples, and/or lack of standardization of testing methods a significant proportion of patients are being treated without the information that Kirsten rat sarcoma and neuroblastoma rat sarcoma (RAS) testing can provide. The detection of mutated circulating tumor DNA by BEAMing technology addresses this gap in care and allows these patients to receive international guideline-recommended expanded RAS testing with rapid turnaround times. Furthermore, the overall concordance between OncoBEAM RAS colorectal cancer testing and standard of care tissue testing is very high (93.3%). This article presents an overview of the clinical utility and potential applications of this minimally invasive method, such as early detection of emergent resistance to anti-epidermal growth factor receptor therapy. If appropriately implemented, BEAMing technology holds considerable promise to enhance the quality of patient care and improve clinical outcomes. © The Author 2017. Published by Oxford University Press on behalf of the European Society for Medical Oncology.

CLL Cells Respond to B-Cell Receptor Stimulation with a MicroRNA/mRNA Signature Associated with MYC Activation and Cell Cycle Progression

PubMed Central

Pede, Valerie; Rombout, Ans; Vermeire, Jolien; Naessens, Evelien; Mestdagh, Pieter; Robberecht, Nore; Vanderstraeten, Hanne; Van Roy, Nadine; Vandesompele, Jo; Speleman, Frank; Philippé, Jan; Verhasselt, Bruno

2013-01-01

Chronic lymphocytic leukemia (CLL) is a disease with variable clinical outcome. Several prognostic factors such as the immunoglobulin heavy chain variable genes (IGHV) mutation status are linked to the B-cell receptor (BCR) complex, supporting a role for triggering the BCR in vivo in the pathogenesis. The miRNA profile upon stimulation and correlation with IGHV mutation status is however unknown. To evaluate the transcriptional response of peripheral blood CLL cells upon BCR stimulation in vitro, miRNA and mRNA expression was measured using hybridization arrays and qPCR. We found both IGHV mutated and unmutated CLL cells to respond with increased expression of MYC and other genes associated with BCR activation, and a phenotype of cell cycle progression. Genome-wide expression studies showed hsa-miR-132-3p/hsa-miR-212 miRNA cluster induction associated with a set of downregulated genes, enriched for genes modulated by BCR activation and amplified by Myc. We conclude that BCR triggering of CLL cells induces a transcriptional response of genes associated with BCR activation, enhanced cell cycle entry and progression and suggest that part of the transcriptional profiles linked to IGHV mutation status observed in isolated peripheral blood are not cell intrinsic but rather secondary to in vivo BCR stimulation. PMID:23560086

Idiopathic hypogonadotropic hypogonadism in a mother and her monozygotic twins born after a single embryo transfer.

PubMed

Laitinen, Eeva-Maria; Tommiska, Johanna; Dunkel, Leo; Sankilampi, Ulla; Vaaralahti, Kirsi; Raivio, Taneli

2010-04-01

To describe a mother with idiopathic hypogonadotropic hypogonadism (IHH) and her monozygotic (MZ) twin boys who all have the same heterozygous fibroblast growth factor receptor-1 (FGFR1) gene mutation. Case report. University hospital. A 28-year-old mother with normosmic IHH gave birth to MZ twin boys after a transfer of a single frozen-thawed embryo. Clinical and biochemical evaluation of IHH. Sequence analysis of the 17 coding exons (exons 2-18) and exon-intron boundaries of FGFR1 from polymerase chain reaction-amplified genomic DNA from peripheral blood leukocytes of the subjects. Phenotypic features of the subjects. All subjects harbored a previously undescribed heterozygous FGFR1 mutation (c.2049-1 G-->C), leading to the skipping of exon 16 and thus a loss of amino acids 684-726 in the tyrosine kinase domain of the receptor. The absence of exon 16 was verified at the cDNA level. The twins manifested with microphallus, cryptorchidism, and deficient postnatal activation of the hypothalamic-pituitary-gonadal axis, findings consistent with IHH. Our report underlines that assisted reproductive techniques enable the inheritance of gene mutations causing infertility. This is the first report on the phenotypic features of MZ twins with an FGFR1 mutation. Copyright 2010 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Association of Exon 10A and 10B inactivating mutation of follicle stimulating hormone receptor gene (FSHR) and Polycystic Ovarian Syndrome in Vellore cohort

NASA Astrophysics Data System (ADS)

Sekar, Nishu; Kulkarni, Rucha; Ozalkar, Sharvari; Prabhu, Yogamaya D.; Renu, Kaviyarasi; Ramgir, Shalaka S.; Abilash, V. G.

2017-11-01

Polycystic ovarian syndrome is the most common heterogenous endocrine disorder in women. Follicle stimulating hormone receptor is associated with normal development as well as maturation of follicles and triggers estrogen production in granulosa cells of the ovary. Inactivating mutation in FSHR gene correlated with reduction of ovarian function in women is due to damage to receptor function. This study aims to investigate whether inactivating mutations, in follicle stimulating hormone receptor gene is related to polycystic ovarian morphology in women with PCOS. Genomic DNA isolated from 15 subjects from Sandhya Hospital, Vellore (10 patients with PCOS and 5 healthy controls) was taken for this study. Patient data included a clinical report, hormonal levels, and ovarian morphological details. DNA isolation was followed by DNA amplification by polymerase chain reaction using Exon 10 A and Exon 10 B primers. The PCR-RFLP analysis was performed using Dde1 restriction enzyme. Here we discuss inactivating mutation found in Exon 10 of FSHR gene in patients with PCOS.The absence of inactivating mutation was observed through PCR-RFLP study on Exon 10A and Exon 10B.

An Immunohistochemical Study of Anaplastic Lymphoma Kinase and Epidermal Growth Factor Receptor Mutation in Non-Small Cell Lung Carcinoma

PubMed Central

Verma, Sonal; Kumari, Malti; Mehrotra, Raj; Kushwaha, R A S; Goel, Madhumati; Kumar, Ashutosh; Kant, Surya

2017-01-01

Introduction Lung cancer is one of the leading causes of cancer related death. Targeted treatment for specific markers may help in reducing the cancer related morbidity and mortality. Aim To study expression of Anaplastic Lymphoma Kinase (ALK)and Epidermal Growth Factor Receptor (EGFR) mutations in patients of Non-Small Cell Lung Cancer NSCLC, that are the targets for specific ALK inhibitors and EGFR tyrosine kinase inhibitors. Materials and Methods Total 69 cases of histologically diagnosed NSCLC were examined retrospectively for immunohistochemical expression of EGFR and ALK, along with positive control of normal placental tissue and anaplastic large cell lymphoma respectively. Results Of the NSCLC, Squamous Cell Carcinoma (SCC) accounted for 71.0% and adenocarcinoma was 26.1%. ALK expression was seen in single case of 60-year-old female, non-smoker with adenocarcinoma histology. EGFR expression was seen in both SCC (59.18%) and adenocarcinoma in (77.78%) accounting for 63.77% of all cases. Both ALK and EGFR mutation were mutually exclusive. Conclusion EGFR expression was seen in 63.77% of cases, highlighting the importance of its use in routine analysis, for targeted therapy and better treatment results. Although, ALK expression was seen in 1.45% of all cases, it is an important biomarker in targeted cancer therapy. Also, the mutually exclusive expression of these two markers need further studies to develop a diagnostic algorithm for NSCLC patients. PMID:28892905

Hotspot Mutations in KIT Receptor Differentially Modulate Its Allosterically Coupled Conformational Dynamics: Impact on Activation and Drug Sensitivity

PubMed Central

Chauvot de Beauchêne, Isaure; Allain, Ariane; Panel, Nicolas; Laine, Elodie; Trouvé, Alain; Dubreuil, Patrice; Tchertanov, Luba

2014-01-01

Receptor tyrosine kinase KIT controls many signal transduction pathways and represents a typical allosterically regulated protein. The mutation-induced deregulation of KIT activity impairs cellular physiological functions and causes serious human diseases. The impact of hotspots mutations (D816H/Y/N/V and V560G/D) localized in crucial regulatory segments, the juxtamembrane region (JMR) and the activation (A-) loop, on KIT internal dynamics was systematically studied by molecular dynamics simulations. The mutational outcomes predicted in silico were correlated with in vitro and in vivo activation rates and drug sensitivities of KIT mutants. The allosteric regulation of KIT in the native and mutated forms is described in terms of communication between the two remote segments, JMR and A-loop. A strong correlation between the communication profile and the structural and dynamical features of KIT in the native and mutated forms was established. Our results provide new insight on the determinants of receptor KIT constitutive activation by mutations and resistance of KIT mutants to inhibitors. Depiction of an intra-molecular component of the communication network constitutes a first step towards an integrated description of vast communication pathways established by KIT in physiopathological contexts. PMID:25079768

Structure of the OsSERK2 leucine-rich repeat extracellular domain.

PubMed

McAndrew, Ryan; Pruitt, Rory N; Kamita, Shizuo G; Pereira, Jose Henrique; Majumdar, Dipali; Hammock, Bruce D; Adams, Paul D; Ronald, Pamela C

2014-11-01

Somatic embryogenesis receptor kinases (SERKs) are leucine-rich repeat (LRR)-containing integral membrane receptors that are involved in the regulation of development and immune responses in plants. It has recently been shown that rice SERK2 (OsSERK2) is essential for XA21-mediated resistance to the pathogen Xanthomonas oryzae pv. oryzae. OsSERK2 is also required for the BRI1-mediated, FLS2-mediated and EFR-mediated responses to brassinosteroids, flagellin and elongation factor Tu (EF-Tu), respectively. Here, crystal structures of the LRR domains of OsSERK2 and a D128N OsSERK2 mutant, expressed as hagfish variable lymphocyte receptor (VLR) fusions, are reported. These structures suggest that the aspartate mutation does not generate any significant conformational change in the protein, but instead leads to an altered interaction with partner receptors.

Germline Mutation of the CCK Receptor: A Novel Biomarker for Pancreas Cancer.

PubMed

Alsubai, Jelal; Matters, Gail L; McGovern, Christopher O; Liao, Jiangang; Gilius, Evan L; Smith, Jill P

2016-01-07

Today, genetic biomarkers have been demonstrated to play an important role in identifying at-risk subjects for familial or inherited cancers. We have identified a single-nucleotide polymorphism (SNP) that results in missplicing of the cholecystokinin (CCK) receptor gene and expressing a larger mutated receptor in pancreatic cancer. The purpose of this study was to evaluate the significance and specificity of this SNP as a potential biomarker in patients with pancreatic cancer compared with other gastrointestinal (GI) cancers that also have CCK receptors. DNA was isolated and genotyped for the CCK receptor SNP from frozen tumor tissue from banked specimens of patients with pancreas, gastric, or colon cancer and from human cancer cell lines. Genotype and allelic frequencies were compared between the cancer cohort and two normal control databases using Fisher's exact test and odds ratio (OR). The Kaplan-Meier method was used to estimate the survival for patients with the CCK-B receptor SNP compared with those with the wild-type genotype. Immunohistochemical staining of cancer cells was done to detect the mutated receptor. Colon and gastric cancer patients had similar genotype frequencies for the CCK receptor SNP as that reported in the normal population. In contrast, the prevalence of the SNP in subjects with pancreatic cancer was twice that of controls and other GI cancers. Survival was adversely affected by the presence of the SNP only in those with pancreatic cancer. Immunoreactivity for the mutated receptor was positive in pancreatic cancer tissues with the SNP but absent in other GI cancers. A SNP of the CCK receptor is significantly increased in patients with pancreatic cancer but not in those with other GI malignancies. Therefore, this SNP may be a potential biomarker for pancreatic cancer.

Kinase Regulation by Hydrophobic Spine Assembly in Cancer

PubMed Central

Ahuja, Lalima G.; Meharena, Hiruy S.; Kannan, Natarajan; Kornev, Alexandr P.

2014-01-01

A new model of kinase regulation based on the assembly of hydrophobic spines has been proposed. Changes in their positions can explain the mechanism of kinase activation. Here, we examined mutations in human cancer for clues about the regulation of the hydrophobic spines by focusing initially on mutations to Phe. We identified a selected number of Phe mutations in a small group of kinases that included BRAF, ABL1, and the epidermal growth factor receptor. Testing some of these mutations in BRAF, we found that one of the mutations impaired ATP binding and catalytic activity but promoted noncatalytic allosteric functions. Other Phe mutations functioned to promote constitutive catalytic activity. One of these mutations revealed a previously underappreciated hydrophobic surface that functions to position the dynamic regulatory αC-helix. This supports the key role of the C-helix as a signal integration motif for coordinating multiple elements of the kinase to create an active conformation. The importance of the hydrophobic space around the αC-helix was further tested by studying a V600F mutant, which was constitutively active in the absence of the negative charge that is associated with the common V600E mutation. Many hydrophobic mutations strategically localized along the C-helix can thus drive kinase activation. PMID:25348715

Mutation frequency in 15 common cancer genes in high-risk head and neck squamous cell carcinoma.

PubMed

McBride, Sean M; Rothenberg, S Michael; Faquin, William C; Chan, Annie W; Clark, John R; Ellisen, Leif W; Wirth, Lori J

2014-08-01

With prior studies having looked at unselected cohorts, we sought to explore the mutational landscape in a high-risk group of head and neck squamous cell carcinoma (HNSCC) tumors. A multiplexed polymerase chain reaction (PCR) assay evaluating 68 loci in 15 genes was performed on 64 patients with high-risk HNSCC. Because of the frequent PIK3CA and AKT1 mutations in patients with oropharyngeal carcinoma, we evaluated the relationship between mutation status and both clinical/pathologic variables and tumor control in this subgroup. Seventeen of 64 patients harbored mutations in the assayed loci: 16% in PIK3CA, 9% in TP53, 2% in AKT1, and 2% in epidermal growth factor receptor (EGFR). The frequency of PIK3CA/AKT1 mutations in oropharyngeal and sinonasal primaries was increased compared to other primary sites (35% vs 6%; p = .005). There was no relationship between mutation status and overall survival (OS), disease-specific death, or progression in the oropharyngeal cohort. We identified frequent PIK3CA mutations in patients with high-risk HNSCC confined predominantly to the oropharyngeal and sinonasal subsites; for the first time, mutation in AKT1 has been identified in HNSCC. Copyright © 2014 Wiley Periodicals, Inc.

Profile of the Roche cobas® EGFR mutation test v2 for non-small cell lung cancer.

PubMed

Malapelle, Umberto; Sirera, Rafael; Jantus-Lewintre, Eloísa; Reclusa, Pablo; Calabuig-Fariñas, Silvia; Blasco, Ana; Pisapia, Pasquale; Rolfo, Christian; Camps, Carlos

2017-03-01

The discovery of driver mutations in non-small cell lung cancer (NSCLC) has led to the development of genome-based personalized medicine. Fifteen to 20% of adenocarcinomas harbor an epidermal growth factor receptor (EGFR) activating mutation associated with responses to EGFR tyrosine kinase inhibitors (TKIs). Individual laboratories' expertise and the availability of appropriate equipment are valuable assets in predictive molecular pathology, although the choice of methods should be determined by the nature of the samples to be tested and whether the detection of only well-characterized EGFR mutations or rather, of all detectable mutations, is required. Areas covered: The EGFR mutation testing landscape is manifold and includes both screening and targeted methods, each with their own pros and cons. Here we review one of these companion tests, the Roche cobas® EGFR mutation test v2, from a methodological point of view, also exploring its liquid-biopsy applications. Expert commentary: The Roche cobas® EGFR mutation test v2, based on real time RT-PCR, is a reliable option for testing EGFR mutations in clinical practice, either using tissue-derived DNA or plasma-derived cfDNA. This application will be valuable for laboratories with whose purpose is purely diagnostic and lacking high-throughput technologies.

SDN-1/syndecan regulates growth factor signaling in distal tip cell migrations in C. elegans.

PubMed

Schwabiuk, Megan; Coudiere, Ludivine; Merz, David C

2009-10-01

Mutations in the sdn-1/syndecan gene act as genetic enhancers of the ventral-to-dorsal distal tip cell (DTC) migration defects caused by a weak allele of the netrin receptor gene unc-5. The sdn-1(ev697) allele was identified in a genetic screen for enhancers of unc-5 DTC migration defects, and carried a nonsense mutation predicted to truncate the SDN-1 protein prior to the transmembrane domain. The enhancement of unc-5 caused by an sdn-1 mutation was rescued by expression of wild-type sdn-1 in the hypodermis or nervous system rather than the DTCs, indicating a cell non-autonomous function of sdn-1. The enhancement was also partially reversed by mutations in the egl-17/FGF or egl-20/Wnt genes, suggesting that sdn-1 affects UNC-5 function through a mis-regulation of signaling in growth factor pathways. egl-20 reporter constructs exhibited increased and mis-localized EGL-20 distribution in sdn-1 mutants compared to wild-type animals. Finally, using loss of function mutations, we show that egl-17/Fgf and egl-20/Wnt are partially redundant in regulating the migration pattern of the posterior DTC, as double mutants exhibit significant frequencies of defects in migration phases along both the anteroposterior and dorsoventral axes. Together these results suggest that SDN-1 affects UNC-5 function by regulating the proper extracellular distribution of growth factors.

A novel mutation of the adrenocorticotropin receptor (ACTH-R) gene in a family with the syndrome of isolated glucocorticoid deficiency, but no ACTH-R abnormalities in two families with the triple A syndrome

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsigos, C.; Arai, K.; Latronico, A.C.

1995-07-01

Isolated glucocorticoid deficiency (IGD) is an autosomal recessive disorder characterized by primary adrenocortical insufficiency, usually without mineralocorticoid deficiency. Occasionally, the disorder is associated with alacrima and achalasia of the esophagus (triple A syndrome), suggesting potential heterogeneity in its etiology. Mutations in the ACTH receptor gene have been reported in several families with IGD. We have amplified and directly sequenced the entire intronless ACTH receptor gene in 1 other family with IGD and 2 famlies with triple A syndrome. The proband with IGD was a homozygote for an A {r_arrow}G substitution, changing tyrosine 254 to cysteine in the third extracellular loopmore » of the receptor protein, probably interfering with ligand binding. Both of her parents were heterozygotes for this mutation, which was not detected in 100 normal alleles. No mutations were identified in the entire coding area of the ACTH receptor in the 2 families with triple A syndrome, supporting the idea of a developmental or postreceptor defect in this syndrome. 19 refs., 1 fig.« less

Intratumoral heterogeneity in EGFR mutant NSCLC results in divergent resistance mechanisms in response to EGFR tyrosine kinase inhibition

PubMed Central

Soucheray, Margaret; Capelletti, Marzia; Pulido, Inés; Kuang, Yanan; Paweletz, Cloud P.; Becker, Jeffrey H.; Kikuchi, Eiki; Xu, Chunxiao; Patel, Tarun B.; Al-shahrour, Fatima; Carretero, Julián; Wong, Kwok-Kin; Jänne, Pasi A.; Shapiro, Geoffrey I.; Shimamura, Takeshi

2015-01-01

Non-small cell lung cancers (NSCLC) that have developed resistance to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs), including gefitinib and erlotinib, are clinically linked to an epithelial-to-mesenchymal transition (EMT) phenotype. Here we examined whether modulating EMT maintains the responsiveness of EGFR-mutated NSCLCs to EGFR TKI therapy. Using human NSCLC cell lines harboring mutated-EGFR and a transgenic mouse model of lung cancer driven by mutant EGFR (EGFR-Del19-T790M), we demonstrate that EGFR inhibition induces TGFβ secretion followed by SMAD pathway activation, an event that promotes EMT. Chronic exposure of EGFR-mutated NSCLC cells to TGFβ was sufficient to induce EMT and resistance to EGFR TKI treatment. Furthermore, NSCLC HCC4006 cells with acquired resistance to gefitinib were characterized by a mesenchymal phenotype and displayed a higher prevalence of the EGFR T790M mutated allele. Notably, combined inhibition of EGFR and the TGFβ receptor in HCC4006 cells prevented EMT, but was not sufficient to prevent acquired gefitinib resistance because of an increased emergence of the EGFR T790M allele compared to cells treated with gefitinib alone. Conversely, another independent NSCLC cell line, PC9, reproducibly develops EGFR T790M mutations as the primary mechanism underlying EGFR TKI resistance, even though the prevalence of the mutant allele is lower than that in HCC4006 cells. Thus, our findings underscore heterogeneity within NSCLC cells lines harboring EGFR kinase domain mutations that give rise to divergent resistance mechanisms in response to treatment and anticipate the complexity of EMT suppression as a therapeutic strategy. PMID:26282169

Cabozantinib Is Active against Human Gastrointestinal Stromal Tumor Xenografts Carrying Different KIT Mutations.

PubMed

Gebreyohannes, Yemarshet K; Schöffski, Patrick; Van Looy, Thomas; Wellens, Jasmien; Vreys, Lise; Cornillie, Jasmien; Vanleeuw, Ulla; Aftab, Dana T; Debiec-Rychter, Maria; Sciot, Raf; Wozniak, Agnieszka

2016-12-01

In the majority of gastrointestinal stromal tumors (GIST), oncogenic signaling is driven by KIT mutations. Advanced GIST is treated with tyrosine kinase inhibitors (TKI) such as imatinib. Acquired resistance to TKI is mainly caused by secondary KIT mutations, but can also be attributed to a switch of KIT dependency to another receptor tyrosine kinase (RTK). We tested the efficacy of cabozantinib, a novel TKI targeting KIT, MET, AXL, and vascular endothelial growth factor receptors (VEGFR), in patient-derived xenograft (PDX) models of GIST, carrying different KIT mutations. NMRI nu/nu mice (n = 52) were bilaterally transplanted with human GIST: UZLX-GIST4 (KIT exon 11 mutation, imatinib sensitive), UZLX-GIST2 (KIT exon 9, imatinib dose-dependent resistance), or UZLX-GIST9 (KIT exon 11 and 17 mutations, imatinib resistant). Mice were grouped as control (untreated), imatinib (50 mg/kg/bid), and cabozantinib (30 mg/kg/qd) and treated orally for 15 days. Cabozantinib resulted in significant tumor regression in UZLX-GIST4 and -GIST2 and delayed tumor growth in -GIST9. In all three models, cabozantinib inhibited the proliferative activity, which was completely absent in UZLX-GIST4 and significantly reduced in -GIST2 and -GIST9. Increased apoptotic activity was observed only in UZLX-GIST4. Cabozantinib inhibited the KIT signaling pathway in UZLX-GIST4 and -GIST2. In addition, compared with both control and imatinib, cabozantinib significantly reduced microvessel density in all models. In conclusion, cabozantinib showed antitumor activity in GIST PDX models through inhibition of tumor growth, proliferation, and angiogenesis, in both imatinib-sensitive and imatinib-resistant models. Mol Cancer Ther; 15(12); 2845-52. ©2016 AACR. ©2016 American Association for Cancer Research.