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Sample records for her2 signaling inhibition

  1. Trastuzumab as a preoperative monotherapy does not inhibit HER2 downstream signaling in HER2-positive breast cancer

    PubMed Central

    Lion, Maëva; Harlé, Alexandre; Salleron, Julia; Ramacci, Carole; Campone, Mario; Merlin, Jean-Louis

    2016-01-01

    Human epidermal growth factor 2 (HER2) is overexpressed in 15–20% of breast carcinomas. The overexpression of HER2 was previously associated with a poor prognosis until the development of the first anti-HER2 therapy, trastuzumab, which drastically improves the prognosis of HER2-overexpressing breast cancers. However, its mechanism of action remains not fully understood. Several studies have proposed that the behavior and mechanism of action of trastuzumab may be drastically altered in vitro and in vivo. The present study assesses the ability of trastuzumab to inhibit the phosphorylation of the key-proteins of phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mechanistic target of rapamycin and Ras/Raf/mitogen-activated protein kinase (MAPK) signaling pathways in vitro, in breast cancer cell lines and in tumor biopsies obtained from patients treated with trastuzumab preoperative monotherapy as part of the Unicancer GEP04 RADHER phase II clinical trial. HER2-positive SKBR3 and HER2-negative MCF-7 cell lines were exposed to trastuzumab for 72 h. In total, 41 patients received trastuzumab alone for 6 weeks of preoperative treatment. Biopsies were collected at the baseline and at surgery. A total of 19 pairs of associated baseline and surgery tumor specimens were eligible for protein extraction and comparative phosphoprotein expression analysis, prior to and subsequent to treatment. The expression of phosphoproteins was quantitatively assessed using a multiplex immunoassay. In the SKBR3 cell line, a statistically significant decrease of the expression level of phosphorylated (p-)AKT, p-ribosomal protein S6 kinase B1, p-extracellular signal regulated kinase 1/2 and p-mitogen-activated protein kinase kinase 1 was observed after exposure to trastuzumab. In contrast, no statistically significant variations for levels expression of these phosphoproteins were observed in patients following treatment. The lack of downregulation of PI3K and MAPK pathways could probably

  2. Ganoderma tsugae Extract Inhibits Growth of HER2-Overexpressing Cancer Cells via Modulation of HER2/PI3K/Akt Signaling Pathway

    PubMed Central

    Kuo, Han-Peng; Hsu, Shih-Chung; Li, Jhy-Wei; Tseng, Hsiu-Hsueh; Chuang, Tzu-Chao; Liu, Jah-Yao; Chen, Shih-Jung; Su, Muh-Hwan; Cheng, Yung-Chi; Chou, Wei-Yuan; Kao, Ming-Ching

    2013-01-01

    Ganoderma, also known as Lingzhi or Reishi, has been used for medicinal purposes in Asian countries for centuries. It is a medicinal fungus with a variety of biological properties including immunomodulatory and antitumor activities. In this study, we investigated the molecular mechanisms by which Ganoderma tsugae (GT), one of the most common species of Ganoderma, inhibits the proliferation of HER2-overexpressing cancer cells. Here, we show that a quality assured extract of GT (GTE) inhibited the growth of HER2-overexpressing cancer cells in vitro and in vivo and enhanced the growth-inhibitory effect of antitumor drugs (e.g., taxol and cisplatin) in these cells. We also demonstrate that GTE induced cell cycle arrest by interfering with the HER2/PI3K/Akt signaling pathway. Furthermore, GTE curtailed the expression of the HER2 protein by modulating the transcriptional activity of the HER2 gene and the stability/degradation of the HER2 protein. In conclusion, this study suggests that GTE may be a useful adjuvant therapeutic agent in the treatment of cancer cells that highly express HER2. PMID:23662119

  3. EGFR and HER2 signals play a salvage role in MEK1-mutated gastric cancer after MEK inhibition.

    PubMed

    Mizukami, Takuro; Togashi, Yosuke; Sogabe, Shunsuke; Banno, Eri; Terashima, Masato; De Velasco, Marco A; Sakai, Kazuko; Fujita, Yoshihiko; Tomida, Shuta; Nakajima, Takako Eguchi; Boku, Narikazu; Nishio, Kazuto

    2015-08-01

    Since the prognosis of unresectable advanced gastric cancer remains poor, novel therapeutic strategies are needed. Somatic MEK1 gene mutations have been reported as oncogenic activating mutations in gastric cancer, and MEK inhibitors can be effective against such gastric cancers. In the present study, however, activated EGFR and HER2 signals after treatment with a MEK inhibitor (trametinib) were found in a MEK1-mutated gastric cancer cell line (OCUM-1 cell line) using a phospho-receptor tyrosine kinase array. The phosphorylation of EGFR and HER2 reactivated ERK1/2, which had been inhibited by trametinib, and EGF stimulation led to resistance to trametinib in this cell line. Lapatinib, an EGFR and an HER2 inhibitor, reversed the activation of ERK1/2 by inhibiting the phosphorylation of EGFR and HER2 and cancelled the resistance. The combination of trametinib and lapatinib synergistically inhibited the cell growth of the OCUM-1 cell line and strongly induced apoptosis by inhibiting the activated EGFR and HER2 signals. These results suggest that the EGFR and HER2 signals play a salvage role and are related to resistance to MEK inhibitors in MEK1‑mutated gastric cancer. Moreover, combination therapy with trametinib and lapatinib can exhibit a synergistic effect and may contribute to overcoming the resistance to MEK inhibitors. PMID:26081723

  4. PI3K inhibition results in enhanced HER signaling and acquired ERK dependency in HER2-overexpressing breast cancer

    PubMed Central

    Serra, V; Scaltriti, M; Prudkin, L; Eichhorn, P J A; Ibrahim, Y H; Chandarlapaty, S; Markman, B; Rodriguez, O; Guzman, M; Rodriguez, S; Gili, M; Russillo, M; Parra, J L; Singh, S; Arribas, J; Rosen, N; Baselga, J

    2011-01-01

    There is a strong rationale to therapeutically target the phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) pathway in breast cancer since it is highly deregulated in this disease and it also mediates resistance to anti-HER2 therapies. However, initial studies with rapalogs, allosteric inhibitors of mTORC1, have resulted in limited clinical efficacy probably due to the release of a negative regulatory feedback loop that triggers AKT and ERK signaling. Since activation of AKT occurs via PI3K, we decided to explore whether PI3K inhibitors prevent the activation of these compensatory pathways. Using HER2-overexpressing breast cancer cells as a model, we observed that PI3K inhibitors abolished AKT activation. However, PI3K inhibition resulted in a compensatory activation of the ERK signaling pathway. This enhanced ERK signaling occurred as a result of activation of HER family receptors as evidenced by induction of HER receptors dimerization and phosphorylation, increased expression of HER3 and binding of adaptor molecules to HER2 and HER3. The activation of ERK was prevented with either MEK inhibitors or anti-HER2 monoclonal antibodies and tyrosine kinase inhibitors. Combined administration of PI3K inhibitors with either HER2 or MEK inhibitors resulted in decreased proliferation, enhanced cell death and superior anti-tumor activity compared with single agent PI3K inhibitors. Our findings indicate that PI3K inhibition in HER2-overexpressing breast cancer activates a new compensatory pathway that results in ERK dependency. Combined anti-MEK or anti-HER2 therapy with PI3K inhibitors may be required in order to achieve optimal efficacy in HER2-overexpressing breast cancer. This approach warrants clinical evaluation. PMID:21278786

  5. Inhibition of HER2-integrin signaling by Cucurbitacin B leads to in vitro and in vivo breast tumor growth suppression

    PubMed Central

    Gupta, Parul; Srivastava, Sanjay K.

    2014-01-01

    HER2, an oncogenic receptor is overexpressed in about 25-30% of breast cancer patients. HER2 has been shown to play role in tumor promotion by having cross-talk with multiple oncogenic pathways in cancer cells. Our results show that Cucurbitacin B (CuB), a triterpenoid steroidal compound inhibited the growth of various breast cancer cells with an IC50 ranging from 18-50nM after 48 and 72 h of treatment. Our study also revealed the significant inhibitory effects of CuB on HER2 and integrin signaling in breast cancer. Notably, CuB inhibited ITGA6 and ITGB4 (integrin α6 & integrin β4), which are overexpressed in breast cancer. Furthermore, CuB also induced the expression of major ITGB1and ITGB3, which are known to cause integrin-mediated cell death. In addition, we observed that TGFβ treatment resulted in the increased association of HER2 with ITGA6 and this association was inhibited by CuB treatment. Efficacy of CuB was tested in vivo using two different orthotopic models of breast cancer. MDA-MB-231 and 4T-1 cells were injected orthotopically in the mammary fat pad of female athymic nude mice or BALB/c mice respectively. Our results showed that CuB administration inhibited MDA-MB-231 orthotopic tumors by 55%, and 4T-1 tumors by 40%. The 4T-1 cells represent stage IV breast cancer and form very aggressive tumors. CuB mediated breast tumor growth suppression was associated with the inhibition of HER2/integrin signaling. Our results suggest novel targets of CuB in breast cancer in vitro and in vivo. PMID:24729020

  6. Trastuzumab, but Not Pertuzumab, Dysregulates HER2 Signaling to Mediate Inhibition of Autophagy and Increase in Reactive Oxygen Species Production in Human Cardiomyocytes.

    PubMed

    Mohan, Nishant; Shen, Yi; Endo, Yukinori; ElZarrad, M Khair; Wu, Wen Jin

    2016-06-01

    Dysregulation of autophagy has been implicated in various cardiovascular diseases. Trastuzumab, a humanized monoclonal antibody, binds to HER2 domain IV and is approved for the treatment of HER2-positive breast cancer. Trastuzumab therapy is associated with considerable cardiotoxicity, the mechanism of which remains unclear. HER2 signaling plays a pivotal role in cardiomyocyte development and survival and is essential for the prevention of cardiomyopathy. However, a direct link has not been confirmed between trastuzumab-induced cardiomyopathy and impaired HER2 signaling. Our data reveal a novel mechanism by which trastuzumab dysregulates HER2 signaling and impairs basal autophagic process in human primary cardiomyocytes. Specifically, trastuzumab treatment leads to the phosphorylation of HER1-Y845 and HER2-Y1248 and the activation of Erk. This in turn results in upregulation of mTOR signaling pathway and subsequently inhibition of autophagy in primary cardiomyocytes and C57BL/6 mice. Trastuzumab-induced downregulation of autophagy is further supported by the fact that trastuzumab treatment reduces protein levels of autophagosome-associated signaling molecules such as Atg 5-12, Atg 7, Atg 14, and Beclin 1. We further demonstrated that trastuzumab-mediated inhibition of autophagy resulted in the increased production of reactive oxygen species (ROS) in cardiomyocytes. Pertuzumab, another anti-HER2 therapeutic mAb binding to HER2 domain II, fails to modulate HER2 signaling and is unable to inhibit autophagy and to increase ROS production in cardiomyocytes. This study provides novel mechanistic insights into trastuzumab-induced cardiotoxicity, which may assist in formulating novel approaches for clinical management of trastuzumab-induced cardiomyopathy. Mol Cancer Ther; 15(6); 1321-31. ©2016 AACR. PMID:27197303

  7. PMCA2 regulates HER2 protein kinase localization and signaling and promotes HER2-mediated breast cancer.

    PubMed

    Jeong, Jaekwang; VanHouten, Joshua N; Dann, Pamela; Kim, Wonnam; Sullivan, Catherine; Yu, Herbert; Liotta, Lance; Espina, Virginia; Stern, David F; Friedman, Peter A; Wysolmerski, John J

    2016-01-19

    In the lactating mammary gland, the plasma membrane calcium ATPase2 (PMCA2) transports milk calcium. Its expression is activated in breast cancers, where high tumor levels predict increased mortality. We find that PMCA2 expression correlates with HER2 levels in breast cancers and that PMCA2 interacts with HER2 in specific actin-rich membrane domains. Knocking down PMCA2 increases intracellular calcium, disrupts interactions between HER2 and HSP-90, inhibits HER2 signaling, and results in internalization and degradation of HER2. Manipulating PMCA2 levels regulates the growth of breast cancer cells, and knocking out PMCA2 inhibits the formation of tumors in mouse mammary tumor virus (MMTV)-Neu mice. These data reveal previously unappreciated molecular interactions regulating HER2 localization, membrane retention, and signaling, as well as the ability of HER2 to generate breast tumors, suggesting that interactions between PMCA2 and HER2 may represent therapeutic targets for breast cancer. PMID:26729871

  8. Quercetin induces caspase-dependent extrinsic apoptosis through inhibition of signal transducer and activator of transcription 3 signaling in HER2-overexpressing BT-474 breast cancer cells

    PubMed Central

    SEO, HYE-SOOK; KU, JIN MO; CHOI, HAN-SEOK; CHOI, YOUN KYUNG; WOO, JONG-KYU; KIM, MINSOO; KIM, ILHWAN; NA, CHANG HYEOK; HUR, HANSOL; JANG, BO-HYOUNG; SHIN, YONG CHEOL; KO, SEONG-GYU

    2016-01-01

    Flavonoids are assumed to exert beneficial effects in different types of cancers at high concentrations. Yet, their molecular mechanisms of action remain unknown. The present study aimed to examine the effect of quercetin on proliferation and apoptosis in HER2-expressing breast cancer cells. The anti-proliferative effects of quercetin were examined by proliferation, MTT and clonogenic survival assays. The effect of quercetin on expression of apoptotic molecules was determined by western blotting. Luciferase reporter assay was performed to measure signal transducer and activator of transcription 3 (STAT3) transcriptional activity. ELISA assay was performed to measure intracellular MMP-9 levels. Immunocytochemistry was performed to evaluate the nuclear STAT3 level. The results revealed that quercetin inhibited the proliferation of BT-474 cells in a dose- and time-dependent manner. Quercetin also inhibited clonogenic survival (anchorage-dependent and -independent) of BT-474 cells in a dose-dependent manner. These growth inhibitions were accompanied with an increase in sub-G0/G1 apoptotic populations. Quercetin induced caspase-dependent extrinsic apoptosis upregulating the levels of cleaved caspase-8 and cleaved caspase-3, and inducing the cleavage of poly(ADP-ribose) polymerase (PARP). In contrast, quercetin did not induce apoptosis via intrinsic mitochondrial apoptosis pathway since this compound did not decrease the mitochondrial membrane potential and did not affect the levels of B-cell lymphoma 2 (Bcl-2) and Bcl-2-associated X protein (BAX). Quercetin reduced the expression of phospho-JAK1 and phospho-STAT3 and decreased STAT3-dependent luciferase reporter gene activity in the BT-474 cells. Quercetin inhibited MMP-9 secretion and decreased the nuclear translocation of STAT3. Our study indicates that quercetin induces apoptosis at concentrations >20 µM through inhibition of STAT3 signaling and could serve as a useful compound to prevent or treat HER2

  9. Quercetin induces caspase-dependent extrinsic apoptosis through inhibition of signal transducer and activator of transcription 3 signaling in HER2-overexpressing BT-474 breast cancer cells.

    PubMed

    Seo, Hye-Sook; Ku, Jin Mo; Choi, Han-Seok; Choi, Youn Kyung; Woo, Jong-Kyu; Kim, Minsoo; Kim, Ilhwan; Na, Chang Hyeok; Hur, Hansol; Jang, Bo-Hyoung; Shin, Yong Cheol; Ko, Seong-Gyu

    2016-07-01

    Flavonoids are assumed to exert beneficial effects in different types of cancers at high concentrations. Yet, their molecular mechanisms of action remain unknown. The present study aimed to examine the effect of quercetin on proliferation and apoptosis in HER2-expressing breast cancer cells. The anti-proliferative effects of quercetin were examined by proliferation, MTT and clonogenic survival assays. The effect of quercetin on expression of apoptotic molecules was determined by western blotting. Luciferase reporter assay was performed to measure signal transducer and activator of transcription 3 (STAT3) transcriptional activity. ELISA assay was performed to measure intracellular MMP-9 levels. Immunocytochemistry was performed to evaluate the nuclear STAT3 level. The results revealed that quercetin inhibited the proliferation of BT-474 cells in a dose- and time-dependent manner. Quercetin also inhibited clonogenic survival (anchorage-dependent and -independent) of BT-474 cells in a dose-dependent manner. These growth inhibitions were accompanied with an increase in sub-G0/G1 apoptotic populations. Quercetin induced caspase-dependent extrinsic apoptosis upregulating the levels of cleaved caspase-8 and cleaved caspase-3, and inducing the cleavage of poly(ADP‑ribose) polymerase (PARP). In contrast, quercetin did not induce apoptosis via intrinsic mitochondrial apoptosis pathway since this compound did not decrease the mitochondrial membrane potential and did not affect the levels of B-cell lymphoma 2 (Bcl-2) and Bcl-2-associated X protein (BAX). Quercetin reduced the expression of phospho-JAK1 and phospho-STAT3 and decreased STAT3-dependent luciferase reporter gene activity in the BT-474 cells. Quercetin inhibited MMP-9 secretion and decreased the nuclear translocation of STAT3. Our study indicates that quercetin induces apoptosis at concentrations >20 µM through inhibition of STAT3 signaling and could serve as a useful compound to prevent or treat HER2

  10. Inhibition of fatty acid synthase suppresses U-2 OS cell invasion and migration via downregulating the activity of HER2/PI3K/AKT signaling pathway in vitro

    SciTech Connect

    Wang, Tao Fang; Wang, Heng; Peng, Ai Fen; Luo, Qing Feng; Liu, Zhi Li; Zhou, Rong Ping; Gao, Song; Zhou, Yang; Chen, Wen Zhao

    2013-10-18

    Highlights: •We investigate the relationship between FASN and HER2 or p-HER2 by IHC in OS tissues. •We construct FASN-specific RNAi plasmid. •Inhibiting FASN down-regulates HER2/PI3K/AKT cell signaling in U-2 OS. •Inhibiting FASN blocks U-2 OS cell invasion and migration. -- Abstract: FASN plays an important role in the malignant phenotype of various tumors. Our previous studies show that inhibition FASN could induce apoptosis and inhibit proliferation in human osteosarcoma (OS) cell in vivo and vitro. The aim in this study was to investigate the effect of inhibition FASN on the activity of HER2/PI3K/AKT axis and invasion and migration of OS cell. The expression of FASN, HER2 and p-HER2(Y1248) proteins was detected by immunohistochemistry in OS tissues from 24 patients with pulmonary metastatic disease, and the relationship between FASN and p-HER2 as well as HER2 was investigated. The results showed that there was a positive correlation between FASN and HER2 as well as p-HER2 protein expression. The U-2 OS cells were transfected with either the FASN specific RNAi plasmid or the negative control RNAi plasmid. FASN mRNA was measured by RT-PCR. Western blot assays was performed to examine the protein expression of FASN, HER2, p-HER2(Y1248), PI3K, Akt and p-Akt (Ser473). Migration and invasion of cells were investigated by wound healing and transwell invasion assays. The results showed that the activity of HER2/PI3K/AKT signaling pathway was suppressed by inhibiting FASN. Meanwhile, the U-2OS cells migration and invasion were also impaired by inhibiting the activity of FASN/HER2/PI3K/AKT. Our results indicated that inhibition of FASN suppresses OS cell invasion and migration via down-regulation of the “HER2/PI3K/AKT” axis in vitro. FASN blocker may be a new therapeutic strategy in OS management.

  11. STAT3-survivin signaling mediates a poor response to radiotherapy in HER2-positive breast cancers

    PubMed Central

    Seong, Min-Ki; Seol, Hyesil; Oh, Jeong Su; Kim, Eun-Kyu; Chang, Jong Wook; Hwang, Sang-Gu; Noh, Woo Chul

    2016-01-01

    Although radiotherapy resistance is associated with locoregional recurrence and distant metastasis in breast cancers, clinically relevant molecular markers and critical signaling pathways of radioresistant breast cancer are yet to be defined. Herein, we show that HER2-STAT3-survivin regulation is associated with radiotherapy resistance in HER2-positive breast cancers. Depletion of HER2 by siRNA sensitized HER2-positive breast cancer cells to irradiation by decreasing STAT3 activity and survivin, a STAT3 target gene, expression in HER2-positive breast cancer cells. Furthermore, inhibition of STAT3 activation or depletion of survivin also sensitized HER2-positive breast cancer cells to irradiation, suggesting that the HER2-STAT3-survivin axis is a key pathway in radiotherapy resistance of HER2-positive breast cancer cells. In addition, our clinical analysis demonstrated the association between HER2-positive breast cancers and radiotherapy resistance. Notably, we found that increased expression of phosphorylated STAT3, STAT3, and survivin correlated with a poor response to radiotherapy in HER2-positive breast cancer tissues. These findings suggest that the HER2-STAT3-survivin axis might serve as a predictive marker and therapeutic target to overcome radiotherapy resistance in HER2-positive breast cancers. PMID:26755645

  12. The role of MAPK signaling pathway in the Her-2-positive meningiomas.

    PubMed

    Wang, Zhaoyin; Wang, Weijia; Xu, Shan; Wang, Shanshan; Tu, Yi; Xiong, Yifeng; Mei, Jinhong; Wang, Chunliang

    2016-08-01

    Meningiomas are common types of adult nerve system tumors. Although most cases are considered benign, due to its high rate of recurrence and easy malignant progression to anaplastic meningioma they present a puzzle for the current treatment. The HER-2 oncogene has important value for meningioma cells development and progression. So far, little is known about the effect on the exact underlying signal pathway and molecular mechanisms of HER-2-positive meningioma cells. The goal of the present study was to determine the effects of HER-2 gene and possible involvement of MAPK signal pathway in human malignant meningioma. We applied q-PCR analysis, immunofluorescence (IF) staining, western blot analysis, animal model, MAPK inhibition, MTT assay and cell invasion analysis for the investigation. The results demonstrated that the downregulation of the expression of HER-2 significantly inhibited cell motility and proliferation of human meningioma cells in vivo. Accordingly, in the HER-2-overexpression meningioma cells with the inhibition of ERK1/2, ERK5, JNK, in the cells with the ERK1/2, ERK5 inhibition, protein expression was markedly suppressed as well as the cell proliferation resistance. No difference was observed in the HER-2-overexpression meningioma cells with the inhibition of JNK. These findings suggest that HER-2 gene can affect the proliferation ability of human meningioma cells in vivo and MAPK signal pathway may contribute to the carcinogenesis and development of human meningiomas combinating with HER-2. PMID:27279438

  13. The role of MAPK signaling pathway in the Her-2-positive meningiomas

    PubMed Central

    Wang, Zhaoyin; Wang, Weijia; Xu, Shan; Wang, Shanshan; Tu, Yi; Xiong, Yifeng; Mei, Jinhong; Wang, Chunliang

    2016-01-01

    Meningiomas are common types of adult nerve system tumors. Although most cases are considered benign, due to its high rate of recurrence and easy malignant progression to anaplastic meningioma they present a puzzle for the current treatment. The HER-2 oncogene has important value for meningioma cells development and progression. So far, little is known about the effect on the exact underlying signal pathway and molecular mechanisms of HER-2-positive meningioma cells. The goal of the present study was to determine the effects of HER-2 gene and possible involvement of MAPK signal pathway in human malignant meningioma. We applied q-PCR analysis, immunofluorescence (IF) staining, western blot analysis, animal model, MAPK inhibition, MTT assay and cell invasion analysis for the investigation. The results demonstrated that the downregulation of the expression of HER-2 significantly inhibited cell motility and proliferation of human meningioma cells in vivo. Accordingly, in the HER-2-overexpression meningioma cells with the inhibition of ERK1/2, ERK5, JNK, in the cells with the ERK1/2, ERK5 inhibition, protein expression was markedly suppressed as well as the cell proliferation resistance. No difference was observed in the HER-2-overexpression meningioma cells with the inhibition of JNK. These findings suggest that HER-2 gene can affect the proliferation ability of human meningioma cells in vivo and MAPK signal pathway may contribute to the carcinogenesis and development of human meningiomas combinating with HER-2. PMID:27279438

  14. Induction of caspase-dependent extrinsic apoptosis by apigenin through inhibition of signal transducer and activator of transcription 3 (STAT3) signalling in HER2-overexpressing BT-474 breast cancer cells

    PubMed Central

    Seo, Hye-Sook; Jo, Jae Kyung; Ku, Jin Mo; Choi, Han-Seok; Choi, Youn Kyung; Woo, Jong-Kyu; in Kim, Hyo; Kang, Soo-yeon; Lee, Kang min; Nam, Koong Won; Park, Namkyu; Jang, Bo-Hyoung; Shin, Yong Cheol; Ko, Seong-Gyu

    2015-01-01

    Phytoestrogen intake is known to be beneficial to decrease breast cancer incidence and progression. But its molecular mechanisms of action are still unknown. The present study aimed to examine the effect of apigenin on proliferation and apoptosis in HER2-expressing breast cancer cells. In our experiments, apigenin inhibited the proliferation of BT-474 cells in a dose- and time-dependent manner. Apigenin also inhibited clonogenic survival (anchorage-dependent and -independent) of BT-474 cells in a dose-dependent manner. These growth inhibitions were accompanied with an increase in sub-G0/G1 apoptotic populations. Apigenin-induced extrinsic a caspase-dependent apoptosis up-regulating the levels of cleaved caspase-8 and cleaved caspase-3, and inducing the cleavage of poly (ADP-ribose) polymerase (PARP). Whereas, apigenin did not induce apoptosis via intrinsic mitochondrial apoptosis pathway since this compound did not decrease mitochondrial membrane potential without affecting the levels of B-cell lymphoma 2 (Bcl-2) and Bcl-2-associated X protein (BAX). Apigenin reduced the expression of phospho-JAK1, phospho-JAK2 and phospho-STAT3 and decreased signal transducer and activator of transcription 3 (STAT3) dependent luciferase reporter gene activity in BT-474 cells. Apigenin inhibited CoCl2-induced VEGF secretion and decreased the nuclear translocation of STAT3. Our study indicates that apigenin induces apoptosis through inhibition of STAT3 signalling and could serve as a useful compound to prevent or treat HER2-overexpressing breast cancer. PMID:26500281

  15. EGFR and HER2 signaling in breast cancer brain metastasis

    PubMed Central

    Sirkisoon, Sherona R.; Carpenter, Richard L.; Rimkus, Tadas; Miller, Lance; Metheny-Barlow, Linda; Lo, Hui-Wen

    2016-01-01

    Breast cancer occurs in approximately 1 in 8 women and 1 in 37 women with breast cancer succumbed to the disease. Over the past decades, new diagnostic tools and treatments have substantially improved the prognosis of women with local diseases. However, women with metastatic disease still have a dismal prognosis without effective treatments. Among different molecular subtypes of breast cancer, the HER2-enriched and basal-like subtypes typically have higher rates of metastasis to the brain. Basal-like metastatic breast tumors frequently express EGFR. Consequently, HER2- and EGFR-targeted therapies are being used in the clinic and/or evaluated in clinical trials for treating breast cancer patients with brain metastases. In this review, we will first provide an overview of the HER2 and EGFR signaling pathways. The roles that EGFR and HER2 play in breast cancer metastasis to the brain will then be discussed. Finally, we will summarize the preclinical and clinical effects of EGFR- and HER2-targeted therapies on breast cancer metastasis. PMID:26709660

  16. Structure-activity Relationships of Peptidomimetics that Inhibit PPI of HER2-HER3

    PubMed Central

    Kanthala, Shanthi; Gauthier, Ted; Satyanarayanajois, Seetharama

    2014-01-01

    Human epidermal growth factor receptor-2 (HER2) is a tyrosine kinase family protein receptor that is known to undergo heterodimerization with other members of the family of epidermal growth factor receptors (EGFR) for cell signaling. Overexpression of HER2 and deregulation of signaling has implications in breast, ovarian, and lung cancers. We have designed several peptidomimetics to block the HER2-mediated dimerization, resulting in antiproliferative activity for cancer cells. In the present work we have investigated the structure-activity relationships of peptidomimetic analogs of compound 5. Compound 5 was conformationally constrained by N- and C-terminal modification and cyclization as well as by substitution with D-amino acids at the N-and C-termini. Among the compounds studied in this work, a peptidomimetic compound 21 with D-amino acid substitution and its N- and C-termini capped with acetyl and amide functional groups and a reversed sequence compared to that of compound 5 exhibited better antiproliferative activity in HER2-overexpressed breast, ovarian, and lung cancer cell lines. Compound 21 was further evaluated for its protein-protein interaction (PPI) inhibition ability using enzyme fragment complementation (EFC) assay, proximity ligation assay (PLA), and Western blot analysis. Results suggested that compound 21 is able to block HER2:HER3 interaction and inhibit phosphorylation of the kinase domain of HER2. The mode of binding of compound 21 to HER2 protein was modeled using a docking method. Compound 21 seems to bind to domain IV of HER2 near the PPI site of EGFR:HER2 and HER:HER3 and inhibit PPI. PMID:24222531

  17. Targeting CXCR1/2 Significantly Reduces Breast Cancer Stem Cell Activity and Increases the Efficacy of Inhibiting HER2 via HER2-dependent and -independent Mechanisms

    PubMed Central

    Singh, Jagdeep K.; Farnie, Gillian; Bundred, Nigel J.; Simões, Bruno M; Shergill, Amrita; Landberg, Göran; Howell, Sacha; Clarke, Robert B.

    2012-01-01

    Purpose Breast cancer stem-like cells (CSCs) are an important therapeutic target as they are predicted to be responsible for tumour initiation, maintenance and metastases. Interleukin-8 (IL-8) is upregulated in breast cancer and associated with poor prognosis. Breast cancer cell line studies indicate that IL-8 via its cognate receptors, CXCR1 and CXCR2, is important in regulating breast CSC activity. We investigated the role of IL-8 in the regulation of CSC activity using patient-derived breast cancers and determined the potential benefit of combining CXCR1/2 inhibition with HER2-targeted therapy. Experimental design CSC activity of metastatic and invasive human breast cancers (n=19) was assessed ex vivo using the mammosphere colony forming assay. Results Metastatic fluid IL-8 level correlated directly with mammosphere formation (r=0.652; P<0.05; n=10). Recombinant IL-8 directly increased mammosphere formation/self-renewal in metastatic and invasive breast cancers (n=17). IL-8 induced activation of EGFR/HER2 and downstream signalling pathways and effects were abrogated by inhibition of SRC, EGFR/HER2, PI3K or MEK. Furthermore, lapatinib inhibited the mammosphere-promoting effect of IL-8 in both HER2-positive and negative patient-derived cancers. CXCR1/2 inhibition also blocked the effect of IL-8 on mammosphere formation and added to the efficacy of lapatinib in HER2-positive cancers. Conclusions These studies establish a role for IL-8 in the regulation of patient-derived breast CSC activity and demonstrate that IL-8/CXCR1/2 signalling is partly mediated via a novel SRC and EGFR/HER2-dependent pathway. Combining CXCR1/2 inhibitors with current HER2-targeted therapies has potential as an effective therapeutic strategy to reduce CSC activity in breast cancer and improve the survival of HER2-positive patients. PMID:23149820

  18. Disulfiram targets cancer stem-like properties and the HER2/Akt signaling pathway in HER2-positive breast cancer.

    PubMed

    Kim, Ji Young; Cho, Youngkwan; Oh, Eunhye; Lee, Nahyun; An, Hyunsook; Sung, Daeil; Cho, Tae-Min; Seo, Jae Hong

    2016-08-28

    HER2-positive breast tumors are known to harbor cancer stem-like cell populations and are associated with an aggressive tumor phenotype and poor clinical outcomes. Disulfiram (DSF), an anti-alcoholism drug, is known to elicit cytotoxicity in many cancer cell types in the presence of copper (Cu). The objective of the present study was to investigate the mechanism of action responsible for the induction of apoptosis by DSF/Cu and its effect on cancer stem cell properties in HER2-positive breast cancers in vitro and in vivo. DSF/Cu treatment induced apoptosis, associated with a marked decrease in HER2, truncated p95HER2, phospho-HER2, HER3, phospho-HER3 and phospho-Akt levels, and p27 nuclear accumulation. This was accompanied by the eradication of cancer stem-like populations, concomitant with the suppression of aldehyde dehydrogenase 1 (ALDH1) activity and mammosphere formation. DSF administration resulted in a significant reduction in tumor growth and an enhancement of apoptosis, as well as HER2 intracellular domain (ICD) and ALDH1A1 downregulation. Our results demonstrate that DSF/Cu induces apoptosis and eliminates cancer stem-like cells via the suppression of HER2/Akt signaling, suggesting that DSF may be potentially effective for the treatment of HER2-positive cancers. PMID:27238567

  19. HER2 signaling pathway activation and response of breast cancer cells to HER2-targeting agents is dependent strongly on the 3D microenvironment

    SciTech Connect

    Weigelt, Britta; Lo, Alvin T; Park, Catherine C; Gray, Joe W; Bissell, Mina J

    2009-07-27

    Development of effective and durable breast cancer treatment strategies requires a mechanistic understanding of the influence of the microenvironment on response. Previous work has shown that cellular signaling pathways and cell morphology are dramatically influenced by three-dimensional (3D) cultures as opposed to traditional two-dimensional (2D) monolayers. Here, we compared 2D and 3D culture models to determine the impact of 3D architecture and extracellular matrix (ECM) on HER2 signaling and on the response of HER2-amplified breast cancer cell lines to the HER2-targeting agents Trastuzumab, Pertuzumab and Lapatinib. We show that the response of the HER2-amplified AU565, SKBR3 and HCC1569 cells to these anti-HER2 agents was highly dependent on whether the cells were cultured in 2D monolayer or 3D laminin-rich ECM gels. Inhibition of {beta}1 integrin, a major cell-ECM receptor subunit, significantly increased the sensitivity of the HER2-amplified breast cancer cell lines to the humanized monoclonal antibodies Trastuzumab and Pertuzumab when grown in a 3D environment. Finally, in the absence of inhibitors, 3D cultures had substantial impact on HER2 downstream signaling and induced a switch between PI3K-AKT- and RAS-MAPKpathway activation in all cell lines studied, including cells lacking HER2 amplification and overexpression. Our data provide direct evidence that breast cancer cells are able to rapidly adapt to different environments and signaling cues by activating alternative pathways that regulate proliferation and cell survival, events that may play a significant role in the acquisition of resistance to targeted therapies.

  20. PP2A inhibition overcomes acquired resistance to HER2 targeted therapy

    PubMed Central

    2014-01-01

    Background HER2 targeted therapies including trastuzumab and more recently lapatinib have significantly improved the prognosis for HER2 positive breast cancer patients. However, resistance to these agents is a significant clinical problem. Although several mechanisms have been proposed for resistance to trastuzumab, the mechanisms of lapatinib resistance remain largely unknown. In this study we generated new models of acquired resistance to HER2 targeted therapy and investigated mechanisms of resistance using phospho-proteomic profiling. Results Long-term continuous exposure of SKBR3 cells to low dose lapatinib established a cell line, SKBR3-L, which is resistant to both lapatinib and trastuzumab. Phospho-proteomic profiling and immunoblotting revealed significant alterations in phospho-proteins involved in key signaling pathways and molecular events. In particular, phosphorylation of eukaryotic elongation factor 2 (eEF2), which inactivates eEF2, was significantly decreased in SKBR3-L cells compared to the parental SKBR3 cells. SKBR3-L cells exhibited significantly increased activity of protein phosphatase 2A (PP2A), a phosphatase that dephosphorylates eEF2. SKBR3-L cells showed increased sensitivity to PP2A inhibition, with okadaic acid, compared to SKBR3 cells. PP2A inhibition significantly enhanced response to lapatinib in both the SKBR3 and SKBR3-L cells. Furthermore, treatment of SKBR3 parental cells with the PP2A activator, FTY720, decreased sensitivity to lapatinib. The alteration in eEF2 phosphorylation, PP2A activity and sensitivity to okadaic acid were also observed in a second HER2 positive cell line model of acquired lapatinib resistance, HCC1954-L. Conclusions Our data suggests that decreased eEF2 phosphorylation, mediated by increased PP2A activity, contributes to resistance to HER2 inhibition and may provide novel targets for therapeutic intervention in HER2 positive breast cancer which is resistant to HER2 targeted therapies. PMID:24958351

  1. Dual Fatty Acid Synthase and HER2 Signaling Blockade Shows Marked Antitumor Activity against Breast Cancer Models Resistant to Anti-HER2 Drugs

    PubMed Central

    Blancafort, Adriana; Giró-Perafita, Ariadna; Oliveras, Glòria; Palomeras, Sònia; Turrado, Carlos; Campuzano, Òscar; Carrión-Salip, Dolors; Massaguer, Anna; Brugada, Ramon; Palafox, Marta; Gómez-Miragaya, Jorge; González-Suárez, Eva; Puig, Teresa

    2015-01-01

    Blocking the enzyme Fatty Acid Synthase (FASN) leads to apoptosis of HER2-positive breast carcinoma cells. The hypothesis is that blocking FASN, in combination with anti-HER2 signaling agents, would be an effective antitumor strategy in preclinical HER2+ breast cancer models of trastuzumab and lapatinib resistance. We developed and molecularly characterized in vitro HER2+ models of resistance to trastuzumab (SKTR), lapatinib (SKLR) and both (SKLTR). The cellular interactions of combining anti-FASN polyphenolic compounds (EGCG and the synthetic G28UCM) with anti-HER2 signaling drugs (trastuzumab plus pertuzumab and temsirolimus) were analyzed. Tumor growth inhibition after treatment with EGCG, pertuzumab, temsirolimus or the combination was evaluated in two in vivo orthoxenopatients: one derived from a HER2+ patient and another from a patient who relapsed on trastuzumab and lapatinib-based therapy. SKTR, SKLR and SKLTR showed hyperactivation of EGFR and p-ERK1/2 and PI3KCA mutations. Dual-resistant cells (SKLTR) also showed hyperactivation of HER4 and recovered levels of p-AKT compared with mono-resistant cells. mTOR, p-mTOR and FASN expression remained stable in SKTR, SKLR and SKLTR. In vitro, anti-FASN compounds plus pertuzumab showed synergistic interactions in lapatinib- and dual- resistant cells and improved the results of pertuzumab plus trastuzumab co-treatment. FASN inhibitors combined with temsirolimus displayed the strongest synergistic interactions in resistant cells. In vivo, both orthoxenopatients showed strong response to the antitumor activity of the combination of EGCG with pertuzumab or temsirolimus, without signs of toxicity. We showed that the simultaneous blockade of FASN and HER2 pathways is effective in cells and in breast cancer models refractory to anti-HER2 therapies. PMID:26107737

  2. Anti-epidermal growth factor receptor monoclonal antibody cetuximab inhibits EGFR/HER-2 heterodimerization and activation.

    PubMed

    Patel, Dipa; Bassi, Rajiv; Hooper, Andrea; Prewett, Marie; Hicklin, Daniel J; Kang, Xiaoqiang

    2009-01-01

    Human carcinomas frequently express one or more members of the epidermal growth factor receptor family. Two family members, epidermal growth factor receptor (EGFR) and c-erbB2/neu (HER2), homodimerize or heterodimerize upon activation with ligand and trigger potent mechanisms of cellular proliferation, differentiation and migration. In this study, we examined the effect of the anti-EGFR monoclonal antibody Erbitux (cetuximab) on human tumor cells expressing both EGFR and HER2. Investigation of the effect of cetuximab on the activation of EGFR-EGFR, EGFR-HER2 and HER2-HER2 homodimers and heterodimers was conducted using the NCI-N87 human gastric carcinoma cell line. Treatment of NCI-N87 cells with cetuximab completely inhibited formation of EGFR-EGFR homodimers and EGFR-HER2 heterodimers. Activation of HER2-HER2 homodimers was not appreciably stimulated by exogenous ligand and was not inhibited by cetuximab treatment. Furthermore, cetuximab inhibited EGF-induced EGFR and HER2 phosphorylation in CAL27, NCI-H226 and NCI-N87 cells. The activation of downstream signaling molecules such as AKT, MAPK and STAT-3 were also inhibited by cetuximab in these cells. To examine the effect of cetuximab on the growth of tumors in vivo, athymic mice bearing established NCI-N87 or CAL27 xenografts were treated with cetuximab (1 mg, i.p., q3d). The growth of NCI-N87 and CAL27 tumors was significantly inhibited with cetuximab therapy compared to the control groups (p<0.0001 in both cases). In the CAL27 xenograft model, tumor growth inhibition by cetuximab treatment was similar to that by cetuximab and trastuzumab combination treatment. Immunohistological analysis of cetuximab-treated tumors showed a decrease in EGFR-HER2 signaling and reduced tumor cell proliferation. These results suggest that cetuximab may be useful in the treatment of carcinomas co-expressing EGFR and HER2. PMID:19082474

  3. A combination of trastuzumab and BAG-1 inhibition synergistically targets HER2 positive breast cancer cells

    PubMed Central

    Papadakis, Emmanouil; Robson, Natalia; Yeomans, Alison; Bailey, Sarah; Laversin, Stephanie; Beers, Stephen; Sayan, A. Emre; Ashton-Key, Margaret; Schwaiger, Stefan; Stuppner, Hermann; Troppmair, Jakob; Packham, Graham; Cutress, Ramsey

    2016-01-01

    Treatment of HER2+ breast cancer with trastuzumab is effective and combination anti-HER2 therapies have demonstrated benefit over monotherapy in the neoadjuvant and metastatic settings. This study investigated the therapeutic potential of targeting the BAG-1 protein co-chaperone in trastuzumab-responsive or -resistant cells. In the METABRIC dataset, BAG-1 mRNA was significantly elevated in HER2+ breast tumors and predicted overall survival in a multivariate analysis (HR = 0.81; p = 0.022). In a breast cell line panel, BAG-1 protein was increased in HER2+ cells and was required for optimal growth as shown by siRNA knockdown. Overexpression of BAG-1S in HER2+ SKBR3 cells blocked growth inhibition by trastuzumab, whereas overexpression of a mutant BAG-1S protein (BAG-1S H3AB), defective in binding HSC70, potentiated the effect of trastuzumab. Injection of a Tet-On SKBR3 clone, induced to overexpress myc-BAG-1S into the mammary fat pads of immunocompromised mice, resulted in 2-fold larger tumors compared to uninduced controls. Induction of myc-BAG-1S expression in two Tet-On SKBR3 clones attenuated growth inhibition by trastuzumab in vitro. Targeting endogenous BAG-1 by siRNA enhanced growth inhibition of SKBR3 and BT474 cells by trastuzumab, while BAG-1 protein-protein interaction inhibitor (Thio-S or Thio-2) plus trastuzumab combination treatment synergistically attenuated growth. In BT474 cells this reduced protein synthesis, caused G1/S cell cycle arrest and targeted the ERK and AKT signaling pathways. In a SKBR3 subpopulation with acquired resistance to trastuzumab BAG-1 targeting remained effective and either Thio-2 or BAG-1 siRNA reduced growth more compared to trastuzumab-responsive parental cells. In summary, targeting BAG-1 function in combination with anti-HER2 therapy might prove beneficial. PMID:26958811

  4. Structural Analysis of the Mechanism of Inhibition and Allosteric Activation of the Kinase Domain of HER2 Protein

    PubMed Central

    Aertgeerts, Kathleen; Skene, Robert; Yano, Jason; Sang, Bi-Ching; Zou, Hua; Snell, Gyorgy; Jennings, Andy; Iwamoto, Keiji; Habuka, Noriyuki; Hirokawa, Aki; Ishikawa, Tomoyasu; Tanaka, Toshimasa; Miki, Hiroshi; Ohta, Yoshikazu; Sogabe, Satoshi

    2011-01-01

    Aberrant signaling of ErbB family members human epidermal growth factor 2 (HER2) and epidermal growth factor receptor (EGFR) is implicated in many human cancers, and HER2 expression is predictive of human disease recurrence and prognosis. Small molecule kinase inhibitors of EGFR and of both HER2 and EGFR have received approval for the treatment of cancer. We present the first high resolution crystal structure of the kinase domain of HER2 in complex with a selective inhibitor to understand protein activation, inhibition, and function at the molecular level. HER2 kinase domain crystallizes as a dimer and suggests evidence for an allosteric mechanism of activation comparable with previously reported activation mechanisms for EGFR and HER4. A unique Gly-rich region in HER2 following the α-helix C is responsible for increased conformational flexibility within the active site and could explain the low intrinsic catalytic activity previously reported for HER2. In addition, we solved the crystal structure of the kinase domain of EGFR in complex with a HER2/EGFR dual inhibitor (TAK-285). Comparison with previously reported inactive and active EGFR kinase domain structures gave insight into the mechanism of HER2 and EGFR inhibition and may help guide the design and development of new cancer drugs with improved potency and selectivity. PMID:21454582

  5. Discovery of AZD8931, an Equipotent, Reversible Inhibitor of Signaling by EGFR, HER2, and HER3 Receptors.

    PubMed

    Barlaam, Bernard; Anderton, Judith; Ballard, Peter; Bradbury, Robert H; Hennequin, Laurent F A; Hickinson, D Mark; Kettle, Jason G; Kirk, George; Klinowska, Teresa; Lambert-van der Brempt, Christine; Trigwell, Cath; Vincent, John; Ogilvie, Donald

    2013-08-01

    Deregulation of HER family signaling promotes proliferation and tumor cell survival and has been described in many human cancers. Simultaneous, equipotent inhibition of EGFR-, HER2-, and HER3-mediated signaling may be of clinical utility in cancer settings where the selective EGFR or HER2 therapeutic agents are ineffective or only modestly active. We describe the discovery of AZD8931 (2), an equipotent, reversible inhibitor of EGFR-, HER2-, and HER3-mediated signaling and the structure-activity relationships within this series. Docking studies based on a model of the HER2 kinase domain helped rationalize the increased HER2 activity seen with the methyl acetamide side chain present in AZD8931. AZD8931 exhibited good pharmacokinetics in preclinical species and showed superior activity in the LoVo tumor growth efficacy model compared to close analogues. AZD8931 is currently being evaluated in human clinical trials for the treatment of cancer. PMID:24900741

  6. The Cooperation between hMena Overexpression and HER2 Signalling in Breast Cancer

    PubMed Central

    Di Modugno, Francesca; Mottolese, Marcella; DeMonte, Lucia; Trono, Paola; Balsamo, Michele; Conidi, Andrea; Melucci, Elisa; Terrenato, Irene; Belleudi, Francesca; Torrisi, Maria Rosaria; Alessio, Massimo; Santoni, Angela; Nisticò, Paola

    2010-01-01

    hMena and the epithelial specific isoform hMena11a are actin cytoskeleton regulatory proteins belonging to the Ena/VASP family. EGF treatment of breast cancer cell lines upregulates hMena/hMena11a expression and phosphorylates hMena11a, suggesting cross-talk between the ErbB receptor family and hMena/hMena11a in breast cancer. The aim of this study was to determine whether the hMena/hMena11a overexpression cooperates with HER-2 signalling, thereby affecting the HER2 mitogenic activity in breast cancer. In a cohort of breast cancer tissue samples a significant correlation among hMena, HER2 overexpression, the proliferation index (high Ki67), and phosphorylated MAPK and AKT was found and among the molecular subtypes the highest frequency of hMena overexpressing tumors was found in the HER2 subtype. From a clinical viewpoint, concomitant overexpression of HER2 and hMena identifies a subgroup of breast cancer patients showing the worst prognosis, indicating that hMena overexpression adds prognostic information to HER2 overexpressing tumors. To identify a functional link between HER2 and hMena, we show here that HER2 transfection in MCF7 cells increased hMena/hMena11a expression and hMena11a phosphorylation. On the other hand, hMena/hMena11a knock-down reduced HER3, AKT and p44/42 MAPK phosphorylation and inhibited the EGF and NRG1-dependent HER2 phosphorylation and cell proliferation. Of functional significance, hMena/hMena11a knock-down reduced the mitogenic activity of EGF and NRG1. Collectively these data provide new insights into the relevance of hMena and hMena11a as downstream effectors of the ErbB receptor family which may represent a novel prognostic indicator in breast cancer progression, helping to stratify patients. PMID:21209853

  7. Negative regulation of HER2 signaling by the PEST-type protein-tyrosine phosphatase BDP1.

    PubMed

    Gensler, Miriam; Buschbeck, Marcus; Ullrich, Axel

    2004-03-26

    Signaling by receptor tyrosine kinases (RTK) mediates a variety of complex cellular functions and in case of deregulation can contribute to pathophysiological processes. A tight and finely tuned control of RTK activity is therefore critical for the cell. We investigated the role of the PEST-type protein-tyrosine phosphatase BDP1 in the regulation of HER2, a member of the epidermal growth factor receptor (EGFR) family of RTKs. Here we demonstrate that HER2 signaling is highly sensitive to BDP1 activity. Overexpression of BDP1 inhibited ligand-induced activation of HER2 but not that of the closely related EGFR. On the other hand, suppression of endogenous BDP1 expression increased the phosphorylation state of HER2. In addition, BDP1 was able to interfere with downstream signaling events by inhibiting the phosphorylation of the adaptor protein Gab1 and reducing mitogen-activated protein kinase activation. Supported by the finding that BDP1 is coexpressed with HER2 in breast cancer cells, we suggest that BDP1 is an important regulator of HER2 activity and thus the first protein-tyrosine phosphatase shown to be involved in HER2 signal attenuation. PMID:14660651

  8. Dimeric HER2-specific affibody molecules inhibit proliferation of the SKBR-3 breast cancer cell line

    SciTech Connect

    Ekerljung, Lina Lindborg, Malin; Gedda, Lars; Frejd, Fredrik Y; Carlsson, Joergen; Lennartsson, Johan

    2008-12-12

    HER2-specific affibody molecules in different formats have previously been shown to be useful tumor targeting agents for radionuclide-based imaging and therapy applications, but their biological effect on tumor cells is not well known. In this study, two dimeric ((Z{sub HER2:4}){sub 2} and (Z{sub HER2:342}){sub 2}) and one monomeric (Z{sub HER2:342}) HER2-specific affibody molecules are investigated with respect to biological activity. Both (Z{sub HER2:4}){sub 2} and (Z{sub HER2:342}){sub 2} were found to decrease the growth rate of SKBR-3 cells to the same extent as the antibody trastuzumab. When the substances were removed, the cells treated with the dimeric affibody molecules continued to be growth suppressed while the cells treated with trastuzumab immediately resumed normal proliferation. The effects of Z{sub HER2:342} were minor on both proliferation and cell signaling. The dimeric (Z{sub HER2:4}){sub 2} and (Z{sub HER2:342}){sub 2} both reduced growth of SKBR-3 cells and may prove therapeutically useful either by themselves or as carriers of radionuclides or other cytotoxic agents.

  9. Methylsulfonylmethane inhibits HER2 expression through STAT5b in breast cancer cells.

    PubMed

    Kang, Dong Young; Darvin, Pramod; Yoo, Young Beom; Joung, Youn Hee; Sp, Nipin; Byun, Hyo Joo; Yang, Young Mok

    2016-02-01

    Breast cancer is the most common cancer in women globally. The factors that increase risk include: late age at first birth, alcohol, radiation exposure, family history of breast cancer, and postmenopausal hormone therapy. Numerous drugs are being developed to treat breast cancer. Among them, Herceptin is used for the treatment of human epidermal growth factor receptor 2 (HER2)-positive cases and targets HER2 effectively and efficiently, but it is very expensive. Methylsulfonylmethane (MSM) is an organic sulfur-containing natural compound having no reported toxicity. We examined MSM in breast cancer cell lines and found it inhibited the proliferation of estrogen receptor-positive and HER2-positive breast cancer cells in a dose-dependent manner. It also suppressed the activation of STAT5b and expression of HER2 in breast cancer cells. We determined the STAT5b binding site (GAS element) in the HER2 gene. Detailed analysis showed that MSM decreased the ability of STAT5b to bind the promoter of the HER2 gene and a luciferase assay demonstrated reduced activity. We confirmed that MSM can effectively regulate STAT5b, and thereby decrease HER2 expression. Therefore, we recommend the use of MSM as an inhibitor for the management of HER2-positive breast cancers. PMID:26648017

  10. EGFR and HER2 receptor kinase signaling mediate epithelial cell invasion by Candida albicans during oropharyngeal infection

    PubMed Central

    Zhu, Weidong; Phan, Quynh T.; Boontheung, Pinmanee; Solis, Norma V.; Loo, Joseph A.; Filler, Scott G.

    2012-01-01

    The fungus Candida albicans is the major cause of oropharyngeal candidiasis (OPC). A key feature of this disease is fungal invasion of oral epithelial cells, a process that can occur by active penetration and fungal-induced endocytosis. Two invasins, Als3 and Ssa1, induce epithelial cell endocytosis of C. albicans, in part by binding to E-cadherin. However, inhibition of E-cadherin function only partially reduces C. albicans endocytosis, suggesting that there are additional epithelial cell receptors for this organism. Here, we show that the EGF receptor (EGFR) and HER2 function cooperatively to induce the endocytosis of C. albicans hyphae. EGFR and HER2 interact with C. albicans in an Als3- and Ssa1-dependent manner, and this interaction induces receptor autophosphorylation. Signaling through both EGFR and HER2 is required for maximal epithelial cell endocytosis of C. albicans in vitro. Importantly, oral infection with C. albicans stimulates the phosphorylation of EGFR and HER2 in the oral mucosa of mice, and treatment with a dual EGFR and HER2 kinase inhibitor significantly decreases this phosphorylation and reduces the severity of OPC. These results show the importance of EGFR and HER2 signaling in the pathogenesis of OPC and indicate the feasibility of treating candidal infections by targeting the host cell receptors with which the fungus interacts. PMID:22891338

  11. Combining AZD8931, a novel EGFR/HER2/HER3 signalling inhibitor, with AZD5363 limits AKT inhibitor induced feedback and enhances antitumour efficacy in HER2-amplified breast cancer models.

    PubMed

    Crafter, Claire; Vincent, John P; Tang, Eric; Dudley, Phillippa; James, Neil H; Klinowska, Teresa; Davies, Barry R

    2015-08-01

    The phosphatidylinositol 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) signalling network is frequently de-regulated in breast cancer and has been shown to mediate resistance to anti-HER2 agents. Whilst constitutive activation of this pathway is emerging as a marker of sensitivity to various PI3K pathway inhibitors, activity of these agents in the clinic may be limited by the presence of feedback loops, leading to reactivation of receptor tyrosine kinases, such as HER2/HER3. To determine whether inhibition of HER2 could increase the efficacy of AZD5363, a novel AKT inhibitor, a panel of breast cancer cells was dosed with AZD5363 in combination with AZD8931, an inhibitor of EGFR/HER2/HER3 signalling. We show that the combined treatment resulted in synergistic growth inhibition and enhanced cell death, specifically in the HER2-amplified cell lines. Investigation of the mechanism by western blot analysis revealed that the addition of AZD8931 prevented the induction of HER2/HER3 phosphorylation induced by AZD5363 and resulted in concomitant inhibition of both the PI3K/AKT/mTOR and ERK signalling pathways and induction of apoptosis. Using the HCC1954 xenograft model, which is resistant to trastuzumab, we show that the combination of AZD5363 and AZD8931 is more efficacious than either agent alone, resulting in profound tumour regressions. We conclude that the activity of AZD5363 in HER2-amplified breast cancer cells is enhanced by the addition of AZD8931 and that dual targeting of AKT and EGFR/HER2/HER3 signalling is an attractive treatment option to be explored in the clinic. PMID:26095475

  12. Critical roles of DMP1 in HER2/neu-Arf-p53 signaling and breast cancer development

    PubMed Central

    Taneja, Pankaj; Maglic, Dejan; Kai, Fumitake; Sugiyama, Takayuki; Kendig, Robert D.; Frazier, Donna P.; Willingham, Mark C.; Inoue, Kazushi

    2010-01-01

    HER2 overexpression stimulates cell growth in p53-mutated cells while it inhibits cell proliferation in those with wild-type p53, but the molecular mechanism is unknown. The Dmp1 promoter was activated by HER2/neu through the PI3K-Akt-NF-κB pathway, which in turn stimulated Arf transcription. Binding of p65 and p52 subunits of NF-κB was demonstrated to the Dmp1 promoter and that of Dmp1 to the Arf promoter upon HER2/neu overexpression. Both Dmp1 and p53 were induced in pre-malignant lesions from MMTV-neu mice and mammary tumorigenesis was significantly accelerated in both Dmp1+/− and Dmp1−/− mice. Selective deletion of Dmp1 and/or overexpression of Tbx2/Pokemon was found in >50 % of wild-type HER2/neu carcinomas while the involvement of Arf, Mdm2, or p53 was rare. Tumors from Dmp1+/−, Dmp1−/−, and wild-type neu mice with hemizygous Dmp1 deletion showed significant downregulation of Arf and p21Cip1/WAF1, showing p53 inactivity and more aggressive phenotypes than tumors without Dmp1 deletion. Notably, endogenous hDMP1 mRNA decreased when HER2 was depleted in human breast cancer cells. Our study demonstrates the pivotal roles of Dmp1 in HER2/neu-p53 signaling and breast carcinogenesis. PMID:21062982

  13. Temporal Profiling of Lapatinib-suppressed Phosphorylation Signals in EGFR/HER2 Pathways*

    PubMed Central

    Imami, Koshi; Sugiyama, Naoyuki; Imamura, Haruna; Wakabayashi, Masaki; Tomita, Masaru; Taniguchi, Masatoshi; Ueno, Takayuki; Toi, Masakazu; Ishihama, Yasushi

    2012-01-01

    Lapatinib is a clinically potent kinase inhibitor for breast cancer patients because of its outstanding selectivity for epidermal growth factor receptor (EGFR) and EGFR2 (also known as HER2). However, there is only limited information about the in vivo effects of lapatinib on EGFR/HER2 and downstream signaling targets. Here, we profiled the lapatinib-induced time- and dose-dependent phosphorylation dynamics in SKBR3 breast cancer cells by means of quantitative phosphoproteomics. Among 4953 identified phosphopeptides from 1548 proteins, a small proportion (5–7%) was regulated at least twofold by 1–10 μm lapatinib. We obtained a comprehensive phosphorylation map of 21 sites on EGFR/HER2, including nine novel sites on HER2. Among them, serine/threonine phosphosites located in a small region of HER2 (amino acid residues 1049–1083) were up-regulated by the drug, whereas all other sites were down-regulated. We show that cAMP-dependent protein kinase is involved in phosphorylation of this particular region of HER2 and regulates HER2 tyrosine kinase activity. Computational analyses of quantitative phosphoproteome data indicated for the first time that protein-protein networks related to cytoskeletal organization and transcriptional/translational regulation, such as RNP complexes (i.e. hnRNP, snRNP, telomerase, ribosome), are linked to EGFR/HER2 signaling networks. To our knowledge, this is the first report to profile the temporal response of phosphorylation dynamics to a kinase inhibitor. The results provide new insights into EGFR/HER2 regulation through region-specific phosphorylation, as well as a global view of the cellular signaling networks associated with the anti-breast cancer action of lapatinib. PMID:22964224

  14. Human breast cancer cells harboring a gatekeeper T798M mutation in HER2 overexpress EGFR ligands and are sensitive to dual inhibition of EGFR and HER2

    PubMed Central

    Rexer, Brent N.; Ghosh, Ritwik; Narasanna, Archana; Estrada, Mónica Valeria; Chakrabarty, Anindita; Song, Youngchul; Engelman, Jeffrey A.; Arteaga, Carlos L.

    2013-01-01

    Purpose Mutations in receptor tyrosine kinase (RTK) genes can confer resistance to receptor-targeted therapies. A T798M mutation in the HER2 oncogene has been shown to confer resistance to the tyrosine kinase inhibitor (TKI) lapatinib. We studied the mechanisms of HER2-T798M-induced resistance to identify potential strategies to overcome that resistance. Experimental Design HER2-T798M was stably expressed in BT474 and MCF10A cells. Mutant cells and xenografts were evaluated for effects of the mutation on proliferation, signaling, and tumor growth after treatment with combinations of inhibitors targeting the EGFR-HER2-HER3-PI3K axis. Results A low 3% allelic frequency of the T798M mutant shifted10-fold the IC50 of lapatinib. In mutant-expressing cells, lapatinib did not block basal phosphorylation of HER2, HER3, AKT and ERK1/2. In vitro kinase assays showed increased autocatalytic activity of HER2-T798M. HER3 association with PI3K p85 was increased in mutant-expressing cells. BT474-T798M cells were also resistant to the HER2 antibody trastuzumab. These cells were sensitive to the pan-PI3K inhibitors BKM120 and XL147 and the irreversible HER2/EGFR TKI afatinib but not the MEK1/2 inhibitor CI-1040, suggesting continued dependence of the mutant cells on ErbB receptors and downstream PI3K signaling. BT474-T798M cells showed increased expression of the EGFR ligands EGF, TGFα, amphiregulin and HB-EGF. Addition of the EGFR neutralizing antibody cetuximab or lapatinib restored trastuzumab sensitivity of BT474-T798M cells and xenografts, suggesting increased EGFR ligand production was causally associated with drug resistance. Conclusions Simultaneous blockade of HER2 and EGFR should be an effective treatment strategy against HER2 gene-amplified breast cancer cells harboring T798M mutant alleles. PMID:23948973

  15. Anti-cancer effect of metformin by suppressing signaling pathway of HER2 and HER3 in tamoxifen-resistant breast cancer cells.

    PubMed

    Kim, Jinkyoung; Lee, Jiyun; Kim, Chungyeul; Choi, Jinhyuk; Kim, Aeree

    2016-05-01

    Development of new therapeutic strategies is becoming increasingly important to overcome tamoxifen resistance. Recently, much interest has been focused on anti-tumor effects of metformin commonly used to treat type II diabetes. Increased protein expression and signaling of epidermal growth factor receptor (EGFR) family is a possible mechanism involved in tamoxifen resistance. Since HER2/HER3 heterodimers are able to induce strong downstream signaling and activate various biological responses such as cellular proliferation and growth, we investigated the anti-cancer effect of metformin by inhibition of signaling pathway via downregulation of HER2 and HER3 using tamoxifen-resistant MCF-7 (TR MCF-7) cells. Compared to MCF-7 cells, TR MCF-7 cells showed increased expression of EGFR, HER2, and HER3, and metformin inhibited the expression of these proteins in a dose- and time-dependent manner. Metformin inhibited activation of HER2 (Tyr1248)/HER3 (Tyr1289)/Akt (Ser473) as well as cell proliferation and colony formation by estrogenic promotion in MCF-7 and TR MCF-7 cells. Known as a HER3 ligand, heregulin (HRG)-β1-induced phosphorylation of HER2, HER3 and Akt, and protein interaction of HER2/HER3 and colony formation were inhibited by metformin in both cells. Consistent with the results in the two cell lines, we identified that metformin inhibited HER2/HER3/Akt signaling axis activated by HRG-β1 using the HER2 and HER3-overexpressing breast cancer cell line SK-BR-3. Lastly, lapatinib-induced HER3 upregulation was significantly inhibited by treatment of metformin in HER3 siRNA-transfected TR MCF-7 cells. These data suggest that metformin might overcome tamoxifen resistance through the inhibition of expression and signaling of receptor tyrosine kinase HER2 and HER3. PMID:26581908

  16. AZD8931, an equipotent, reversible inhibitor of signaling by epidermal growth factor receptor (EGFR), HER2, and HER3: preclinical activity in HER2 non-amplified inflammatory breast cancer models

    PubMed Central

    2014-01-01

    Introduction Epidermal growth factor receptor (EGFR) overexpression has been associated with prognostic and predictive value in inflammatory breast cancer (IBC). Epidermal growth factor receptor 2 (HER2) overexpression is observed at a higher rate in IBC compared with noninflammatory breast cancer. Current clinically available anti-HER2 therapies are effective only in patients with HER2 amplified breast cancer, including IBC. AZD8931 is a novel small-molecule equipotent inhibitor of EGFR, HER2, and HER3 signaling. In this study, we investigated the antitumor activity of AZD8931 alone or in combination with paclitaxel using preclinical models of EGFR-overexpressed and HER2 non-amplified IBC cells. Methods Two IBC cell lines SUM149 and FC-IBC-02 derived from pleural effusion of an IBC patient were used in this study. Cell growth and apoptotic cell death were examined in vitro. For the in vivo tumor growth studies, IBC cells were orthotopically transplanted into the mammary fat pads of immunodeficient mice. AZD8931 was given by daily oral gavage at doses of 25 mg/kg, 5 days/week for 4 weeks. Paclitaxel was subcutaneously injected twice weekly. Results AZD8931 significantly suppressed cell growth of IBC cells and induced apoptosis of human IBC cells in vitro. Significantly, we showed that AZD8931 monotherapy inhibited xenograft growth and the combination of paclitaxel + AZD8931 was demonstrably more effective than paclitaxel or AZD8931 alone treatment at delaying tumor growth in vivo in orthotopic IBC models. Conclusion AZD8931 single agent and in combination with paclitaxel demonstrated signal inhibition and antitumor activity in EGFR-overexpressed and HER2 non-amplified IBC models. These results suggest that AZD8931 may provide a novel therapeutic strategy for the treatment of IBC patients with HER2 non-amplified tumors. PMID:24886365

  17. PIK3CA(H1047R)- and Her2-initiated mammary tumors escape PI3K dependency by compensatory activation of MEK-ERK signaling.

    PubMed

    Cheng, H; Liu, P; Ohlson, C; Xu, E; Symonds, L; Isabella, A; Muller, W J; Lin, N U; Krop, I E; Roberts, T M; Winer, E P; Arteaga, C L; Zhao, J J

    2016-06-01

    Human breast cancers that have HER2 amplification/overexpression frequently carry PIK3CA mutations, and are often associated with a worse prognosis. However, the role of PIK3CA mutations in the initiation and maintenance of these breast cancers remains elusive. In the present study, we generated a compound mouse model that genetically mimics HER2-positive breast cancer with coexisting PIK3CA(H1047R). Induction of PIK3CA(H1047R) expression in mouse mammary glands with constitutive expression of activated Her2/Neu resulted in accelerated mammary tumorigenesis with enhanced metastatic potential. Interestingly, inducible expression of mutant PIK3CA resulted in a robust activation of phosphatidylinositol-3-kinase (PI3K)/AKT signaling but attenuation of Her2/Her3 signaling, and this can be reversed by deinduction of PIK3CA(H1047R) expression. Strikingly, although these Her2(+) PIK3CA(H1047R)-initiated primary mammary tumors are refractory to HER2-targeted therapy, all tumors responded to inactivation of the oncogenic PIK3CA(H1047R), a situation closely mimicking the use of a highly effective inhibitor specifically targeting the mutant PIK3CA/p110a. Notably, these tumors eventually resumed growth, and a fraction of them escaped PI3K dependence by compensatory ERK activation, which can be blocked by combined inhibition of Her2 and MEK. Together, these results suggest that PIK3CA-specific inhibition as a monotherapy followed by combination therapy targeting MAPK and HER2 in a timely manner may be an effective treatment approach against HER2-positive cancers with coexisting PIK3CA-activating mutations. PMID:26640141

  18. The Ephrin-A1/EPHA2 Signaling Axis Regulates Glutamine Metabolism in HER2-Positive Breast Cancer.

    PubMed

    Youngblood, Victoria M; Kim, Laura C; Edwards, Deanna N; Hwang, Yoonha; Santapuram, Pranav R; Stirdivant, Steven M; Lu, Pengcheng; Ye, Fei; Brantley-Sieders, Dana M; Chen, Jin

    2016-04-01

    Dysregulation of receptor tyrosine kinases (RTK) contributes to cellular transformation and cancer progression by disrupting key metabolic signaling pathways. The EPHA2 RTK is overexpressed in aggressive forms of breast cancer, including the HER2(+) subtype, and correlates with poor prognosis. However, the role of EPHA2 in tumor metabolism remains unexplored. In this study, we used in vivo and in vitro models of HER2-overexpressing breast cancer to investigate the mechanisms by which EPHA2 ligand-independent signaling promotes tumorigenesis in the absence of its prototypic ligand, ephrin-A1. We demonstrate that ephrin-A1 loss leads to upregulated glutamine metabolism and lipid accumulation that enhanced tumor growth. Global metabolic profiling of ephrin-A1-null, HER2-overexpressing mammary tumors revealed a significant increase in glutaminolysis, a critical metabolic pathway that generates intermediates for lipogenesis. Pharmacologic inhibition of glutaminase activity reduced tumor growth in both ephrin-A1-depleted and EPHA2-overexpressing tumor allografts in vivo Mechanistically, we show that the enhanced proliferation and glutaminolysis in the absence of ephrin-A1 were attributed to increased RhoA-dependent glutaminase activity. EPHA2 depletion or pharmacologic inhibition of Rho, glutaminase, or fatty acid synthase abrogated the increased lipid content and proliferative effects of ephrin-A1 knockdown. Together, these findings highlight a novel, unsuspected connection between the EPHA2/ephrin-A1 signaling axis and tumor metabolism, and suggest potential new therapeutic targets in cancer subtypes exhibiting glutamine dependency. Cancer Res; 76(7); 1825-36. ©2016 AACR. PMID:26833123

  19. Type II cGMP-dependent protein kinase directly inhibits HER2 activation of gastric cancer cells.

    PubMed

    Zhu, Miaolin; Yao, Xiaoyuan; Wu, Min; Qian, Hai; Wu, Yan; Chen, Yongchang

    2016-02-01

    Our previous study demonstrated that type II cyclic guanosine monophosphate (cGMP)-dependent protein kinase (PKG II) inhibited epidermal growth factor (EGF)-induced phosphorylation/activation of epidermal growth factor receptor (EGFR). Since human epidermal growth factor receptor 2 (HER2) has a similar molecular structure to EGFR, the present study was designed to investigate whether PKG II also inhibits HER2 activation. The human gastric cancer cell line HGC‑27 was infected with an adenoviral construct encoding cDNA of PKG II (Ad‑PKG II) to increase the expression of PKG II and treated with 8‑(4‑chlorophenylthio)guanosine‑3',5'‑cyclic monophosphate (8‑pCPT‑cGMP) to activate the kinase. Western blotting was performed to detect the tyrosine and serine/threonine phosphorylation of HER2. Co‑immunoprecipitation was performed in order to determine the binding between PKG II and HER2. In addition, a QuikChange Lightning Site‑Directed Mutagenesis kit was used to mutate threonine 686 of HER2 to glutamic acid or alanine. The results demonstrated that EGF treatment increased the tyrosine phosphorylation (activation) of HER2. Increasing the PKG II activity of HGC‑27 cells through infection with Ad‑PKG II and stimulation with 8‑pCPT‑cGMP inhibited the EGF‑induced tyrosine phosphorylation/activation of HER2. PKG II bound directly with HER2 and caused phosphorylation of threonine 686. When threonine 686 of HER2 was mutated to alanine, which could not be phosphorylated by PKG II, the inhibitory effect of PKG II on the activation of HER2 was eradicated. When threonine 686 of HER2 was mutated to glutamic acid, which mimicked the phosphorylation of this site, treatment with EGF had no stimulating effect on tyrosine phosphorylation/activation of the mutant HER2. The results suggested that PKG II inhibits EGF‑induced activation of HER2 through binding with and causing threonine 686 phosphorylation of this oncogenic protein. PMID:26676300

  20. Dmp1α Inhibits HER2/neu-Induced Mammary Tumorigenesis

    PubMed Central

    Fry, Elizabeth A.; Taneja, Pankaj; Maglic, Dejan; Zhu, Sinan; Sui, Guangchao; Inoue, Kazushi

    2013-01-01

    Our recent study shows a pivotal role of Dmp1 in quenching hyperproliferative signals from HER2 to the Arf-p53 pathway as a safety mechanism to prevent breast carcinogenesis. To directly demonstrate the role of Dmp1 in preventing HER2/neu-driven oncogenic transformation, we established Flag-Dmp1α transgenic mice (MDTG) under the control of the mouse mammary tumor virus (MMTV) promoter. The mice were viable but exhibited poorly developed mammary glands with markedly reduced milk production; thus more than half of parous females were unable to support the lives of new born pups. The mammary glands of the MDTG mice had very low Ki-67 expression but high levels of Arf, Ink4a, p53, and p21Cip1, markers of senescence and accelerated aging. In all strains of generated MDTG;neu mice, tumor development was significantly delayed with decreased tumor weight. Tumors from MDTG;neu mice expressed Flag-Dmp1α and Ki-67 in a mutually exclusive fashion indicating that transgenic Dmp1α prevented tumor growth in vivo. Genomic DNA analyses showed that the Dmp1α transgene was partially lost in half of the MDTG;neu tumors, and Western blot analyses showed Dmp1α protein downregulation in 80% of the cases. Our data demonstrate critical roles of Dmp1 in preventing mammary tumorigenesis and raise the possibility of treating breast cancer by restoring Dmp1α expression. PMID:24205004

  1. Dmp1α inhibits HER2/neu-induced mammary tumorigenesis.

    PubMed

    Fry, Elizabeth A; Taneja, Pankaj; Maglic, Dejan; Zhu, Sinan; Sui, Guangchao; Inoue, Kazushi

    2013-01-01

    Our recent study shows a pivotal role of Dmp1 in quenching hyperproliferative signals from HER2 to the Arf-p53 pathway as a safety mechanism to prevent breast carcinogenesis. To directly demonstrate the role of Dmp1 in preventing HER2/neu-driven oncogenic transformation, we established Flag-Dmp1α transgenic mice (MDTG) under the control of the mouse mammary tumor virus (MMTV) promoter. The mice were viable but exhibited poorly developed mammary glands with markedly reduced milk production; thus more than half of parous females were unable to support the lives of new born pups. The mammary glands of the MDTG mice had very low Ki-67 expression but high levels of Arf, Ink4a, p53, and p21(Cip1), markers of senescence and accelerated aging. In all strains of generated MDTG;neu mice, tumor development was significantly delayed with decreased tumor weight. Tumors from MDTG;neu mice expressed Flag-Dmp1α and Ki-67 in a mutually exclusive fashion indicating that transgenic Dmp1α prevented tumor growth in vivo. Genomic DNA analyses showed that the Dmp1α transgene was partially lost in half of the MDTG;neu tumors, and Western blot analyses showed Dmp1α protein downregulation in 80% of the cases. Our data demonstrate critical roles of Dmp1 in preventing mammary tumorigenesis and raise the possibility of treating breast cancer by restoring Dmp1α expression. PMID:24205004

  2. 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

  3. HER2 induced EMT and tumorigenicity in breast epithelial progenitor cells is inhibited by coexpression of EGFR

    PubMed Central

    Ingthorsson, S; Andersen, K; Hilmarsdottir, B; Maelandsmo, G M; Magnusson, M K; Gudjonsson, T

    2016-01-01

    The members of the epidermal growth factor receptor (EGFR) kinase family are important players in breast morphogenesis and cancer. EGFR2/HER2 and EGFR expression have a prognostic value in certain subtypes of breast cancer such as HER2-amplified, basal-like and luminal type B. Many clinically approved small molecular inhibitors and monoclonal antibodies have been designed to target HER2, EGFR or both. There is, however, still limited knowledge on how the two receptors are expressed in normal breast epithelium, what effects they have on cellular differentiation and how they participate in neoplastic transformation. D492 is a breast epithelial cell line with stem cell properties that can undergo epithelial to mesenchyme transition (EMT), generate luminal- and myoepithelial cells and form complex branching structures in three-dimensional (3D) culture. Here, we show that overexpression of HER2 in D492 (D492HER2) resulted in EMT, loss of contact growth inhibition and increased oncogenic potential in vivo. HER2 overexpression, furthermore, inhibited endogenous EGFR expression. Re-introducing EGFR in D492HER2 (D492HER2/EGFR) partially reversed the mesenchymal state of the cells, as an epithelial phenotype reappeared both in 3D cultures and in vivo. The D492HER2/EGFR xenografts grow slower than the D492HER2 tumors, while overexpression of EGFR alone (D492EGFR) was not oncogenic in vivo. Consistent with the EGFR-mediated epithelial phenotype, overexpression of EGFR drove the cells toward a myoepithelial phenotype in 3D culture. The effect of two clinically approved anti-HER2 and EGFR therapies, trastuzumab and cetuximab, was tested alone and in combination on D492HER2 xenografts. While trastuzumab had a growth inhibitory effect compared with untreated control, the effect of cetuximab was limited. When administered in combination, the growth inhibitory effect of trastuzumab was less pronounced. Collectively, our data indicate that in HER2-overexpressing D492 cells, EGFR can

  4. HER2 induced EMT and tumorigenicity in breast epithelial progenitor cells is inhibited by coexpression of EGFR.

    PubMed

    Ingthorsson, S; Andersen, K; Hilmarsdottir, B; Maelandsmo, G M; Magnusson, M K; Gudjonsson, T

    2016-08-11

    The members of the epidermal growth factor receptor (EGFR) kinase family are important players in breast morphogenesis and cancer. EGFR2/HER2 and EGFR expression have a prognostic value in certain subtypes of breast cancer such as HER2-amplified, basal-like and luminal type B. Many clinically approved small molecular inhibitors and monoclonal antibodies have been designed to target HER2, EGFR or both. There is, however, still limited knowledge on how the two receptors are expressed in normal breast epithelium, what effects they have on cellular differentiation and how they participate in neoplastic transformation. D492 is a breast epithelial cell line with stem cell properties that can undergo epithelial to mesenchyme transition (EMT), generate luminal- and myoepithelial cells and form complex branching structures in three-dimensional (3D) culture. Here, we show that overexpression of HER2 in D492 (D492(HER2)) resulted in EMT, loss of contact growth inhibition and increased oncogenic potential in vivo. HER2 overexpression, furthermore, inhibited endogenous EGFR expression. Re-introducing EGFR in D492(HER2) (D492(HER2/EGFR)) partially reversed the mesenchymal state of the cells, as an epithelial phenotype reappeared both in 3D cultures and in vivo. The D492(HER2/EGFR) xenografts grow slower than the D492(HER2) tumors, while overexpression of EGFR alone (D492(EGFR)) was not oncogenic in vivo. Consistent with the EGFR-mediated epithelial phenotype, overexpression of EGFR drove the cells toward a myoepithelial phenotype in 3D culture. The effect of two clinically approved anti-HER2 and EGFR therapies, trastuzumab and cetuximab, was tested alone and in combination on D492(HER2) xenografts. While trastuzumab had a growth inhibitory effect compared with untreated control, the effect of cetuximab was limited. When administered in combination, the growth inhibitory effect of trastuzumab was less pronounced. Collectively, our data indicate that in HER2-overexpressing D492

  5. Inhibition of the autocrine IL-6–JAK2–STAT3–calprotectin axis as targeted therapy for HR−/HER2+ breast cancers

    PubMed Central

    Rodriguez-Barrueco, Ruth; Yu, Jiyang; Saucedo-Cuevas, Laura P.; Olivan, Mireia; Llobet-Navas, David; Putcha, Preeti; Castro, Veronica; Murga-Penas, Eva M.; Collazo-Lorduy, Ana; Castillo-Martin, Mireia; Alvarez, Mariano; Cordon-Cardo, Carlos; Kalinsky, Kevin; Maurer, Matthew; Califano, Andrea; Silva, Jose M.

    2015-01-01

    HER2-positive (HER2+) breast adenocarcinomas are a heterogeneous group in which hormone receptor (HR) status influences therapeutic decisions and patient outcome. By combining genome-wide RNAi screens with regulatory network analysis, we identified STAT3 as a critically activated master regulator of HR−/HER2+ tumors, eliciting tumor dependency in these cells. Mechanistically, HR−/HER2+ cells secrete high levels of the interleukin-6 (IL-6) cytokine, inducing the activation of STAT3, which in turn promotes a second autocrine stimulus to increase S100A8/9 complex (calprotectin) production and secretion. Increased calprotectin levels activate signaling pathways involved in proliferation and resistance. Importantly, we demonstrated that inhibition of the IL-6–Janus kinase 2 (JAK2)–STAT3–calprotectin axis with FDA-approved drugs, alone and in combination with HER2 inhibitors, reduced the tumorigenicity of HR−/HER2+ breast cancers, opening novel targeted therapeutic opportunities. PMID:26227964

  6. Pomolic acid inhibits metastasis of HER2 overexpressing breast cancer cells through inactivation of the ERK pathway.

    PubMed

    Kim, Buyun; Kim, Yu Chul; Park, Byoungduck

    2016-08-01

    Expression of the CXC chemokine receptor-4 (CXCR4), a G protein-coupled receptor, and HER2, a receptor tyrosine kinase, strongly correlates with tumor progression and metastatic potential of breast cancer cells. We report the identification of pomolic acid (PA) as a novel regulator of HER2 and CXCR4 expression. We found that PA downregulated the expression of HER2 and CXCR4 in SKBR3 cells in a dose- and time-dependent manner. When investigated for the molecular mechanism(s), it was found that the downregulation of HER2 and CXCR4 was not due to proteolytic degradation but rather to transcriptional regulation as indicated by downregulation of mRNA expression. Moreover, we show that PA inhibits phosphorylation of ERK and reduces NF-κB activation. Suppression of CXCR4 expression by PA correlated with the inhibition of CXCL12-induced invasion of HER2-overexpressing breast cancer cells. Overall, our results demonstrate for the first time that PA is a novel inhibitor of HER2 and CXCR4 expression via kinase pathways and may play a critical role in determining the metastatic potential of breast cancer cells. PMID:27277173

  7. Signaling Pathway of GP88 (Progranulin) in Breast Cancer Cells: Upregulation and Phosphorylation of c-myc by GP88/Progranulin in Her2-Overexpressing Breast Cancer Cells

    PubMed Central

    Kim, Wes E.; Yue, Binbin; Serrero, Ginette

    2015-01-01

    Her2 is a receptor tyrosine kinase overexpressed in 25% of breast tumors. We have shown that the 88 kDa autocrine growth and survival factor GP88 (progranulin) stimulated Her2 phosphorylation and proliferation and conferred Herceptin resistance in Her2-overexpressing cells. Herein, we report that GP88 stimulates c-myc phosphorylation and upregulates c-myc levels in Her2-overexpressing cells. c-myc phosphorylation and upregulation by GP88 were not observed in non-Her2-overexpressing breast cancer cells. c-myc activation was inhibited upon treatment with ERK, PI3 kinase, and c-src pathway inhibitors, U0126, LY294002, and PP2. GP88 also stimulated c-src phosphorylation, a known upstream regulator of c-myc. Thus, we describe here a signaling pathway for GP88 in Her2-overexpressing cells, with GP88 stimulating Src phosphorylation, followed by phosphorylation and upregulation of c-myc. These data would suggest that targeting GP88 could provide a novel treatment approach in breast cancer. PMID:27168723

  8. PTPN12 controls PTEN and the AKT signalling to FAK and HER2 in migrating ovarian cancer cells.

    PubMed

    Villa-Moruzzi, Emma

    2013-03-01

    Several tyrosine phosphatases control cell motility; understanding their signaling helps to decipher cancer mechanisms. Previously, we found that the negative regulation of migration exerted by PTPN12 in ovarian cancer SKOV-3 cells involves direct FAK Y397 targeting, in HER2-dependent way. In this study, we describe that PTPN12 silencing depresses also PTEN RNA and protein. This, in turn, contributes to regulate FAK, through the activation of the PI3K/AKT pathway, resulting in GSK3 inactivation and decreased FAK phosphorylation at the inhibitory and GSK3 target S722. Altogether, in SKOV-3 cells, both PTPN12 and PTEN signaling merge on FAK which is negatively regulated through Y397 dephosphorylation (directly by PTPN12) and S722 phosphorylation (through PTEN/AKT/GSK3). Although HER2 activity sustains SKOV-3 cell motility, the HER2 inhibitor Ag825 impairs migration only in PTPN12 silenced cells, suggesting the ability of PTPN12 to affect HER2. This hypothesis is supported by the finding that, in migrating cells, Ag825 decreases HER2 phosphorylation at Y1248, Y1221/2, and Y877 (i.e., inactivates HER2) only after PTPN12 silencing. Conversely, cell exposure to the PI3K inhibitor LY294002 increases HER2 phosphorylation, suggesting the involvement of PI3K/AKT in HER2 regulation. Altogether, the results reveal a new PTEN mechanism in the control cell migration and suggest a complex cross-talk between PTPN12 and HER2. PMID:23212450

  9. p62: a hub of multiple signaling pathways in HER2-induced mammary tumorigenesis

    PubMed Central

    Cai-McRae, Xiaofeng; Karantza, Vassiliki

    2015-01-01

    We recently reported that depletion of p62 in the background of human epidermal growth factor receptor 2 (HER2) overexpression sensitizes mammary tumor cells to amino acid deprivation, abolishes cellular transformation in vitro, and suppresses mammary tumorigenesis in vivo. Extensive investigation on the underlying molecular mechanisms has revealed a multifaceted role for p62 in HER2-associated mammary tumorigenesis. PMID:27308451

  10. Polymalic acid nanobioconjugate for simultaneous inhibition of tumor growth and immunostimulation in HER2/neu-positive breast cancer✩

    PubMed Central

    Ding, Hui; Helguera, Gustavo; Rodríguez, José A.; Markman, Janet; Luria-Pérez, Rosendo; Gangalum, Pallavi; Portilla-Arias, Jose; Inoue, Satoshi; Daniels-Wells, Tracy R.; Black, Keith; Holler, Eggehard; Penichet, Manuel L.; Ljubimova, Julia Y.

    2013-01-01

    Breast cancer remains the second leading cause of cancer death among women in the United States. The breast cancer prognosis is particularly poor in case of tumors overexpressing the oncoprotein HER2/neu. A new nanobioconjugate of the Polycefin family of anti-cancer drugs based on biodegradable and non-toxic polymalic acid (PMLA) was engineered for a multi-pronged attack on HER2/neu-positive breast cancer cells. An antibody cytokine fusion protein consisting of the immunostimulatory cytokine interleukin-2 (IL-2) genetically fused to an antibody specific for human HER2/neu [anti-HER2/neu IgG3-(IL-2)] was covalently attached to the PMLA backbone to target HER2/neu expressing tumors and ensuring the delivery of IL-2 to the tumor microenvironment. Antisense oligonucleotides (AON) were conjugated to the nanodrug to inhibit the expression of vascular tumor protein laminin-411 in order to block tumor angiogenesis. It is shown that the nanobioconjugate was capable of specifically binding human HER2/neu and retaining the biological activity of IL-2. We also showed the uptake of the nanobioconjugate by HER2/neu-positive breast cancer cells and enhanced tumor targeting in vivo. In addition, the nanobioconjugate was capable of eliciting anti-tumor activity in immunocompetent mice bearing D2F2/E2 murine mammary tumors that express human HER2/neu. Both IgG1 and IgG2a levels were significantly increased in animals treated with the PMLA-fusion nanobioconjugate compared to animals treated with the antibody–cytokine fusion protein alone or control animals, indicative of the induction of a humoral (TH2) and cell-mediated (TH1) immune responses. Animal survival in vivo was significantly longer after treatment with leading nanobioconjugate with fusion [anti-HER2/neu IgG3-(IL-2)] antibody, p < 0.05. The combination of these molecules on a single polymeric platform is expected to act through direct elimination of cancer cells, inhibition of tumor angiogenesis, and orchestration of a

  11. NRF2 Regulates HER2 and HER3 Signaling Pathway to Modulate Sensitivity to Targeted Immunotherapies

    PubMed Central

    Khalil, Hilal S.; Langdon, Simon P.; Kankia, Ibrahim H.; Bown, James; Deeni, Yusuf Y.

    2016-01-01

    NF-E2 related factor-2 (NRF2) is an essential transcription factor for multiple genes encoding antioxidants and detoxification enzymes. NRF2 is implicated in promoting cancer therapeutic resistance by its detoxification function and crosstalk with proproliferative pathways. However, the exact mechanism of this intricate connectivity between NRF2 and growth factor induced proliferative pathway remains elusive. Here, we have demonstrated that pharmacological activation of NRF2 by tert-butylhydroquinone (tBHQ) upregulates the HER family receptors, HER2 and HER3 expression, elevates pAKT levels, and enhances the proliferation of ovarian cancer cells. Preactivation of NRF2 also attenuates the combined growth inhibitory effects of HER2 targeting monoclonal antibodies, Pertuzumab and Trastuzumab. Further, tBHQ caused transcriptional induction of HER2 and HER3, while SiRNA-mediated knockdown of NRF2 prevented this and further caused transcriptional repression and enhanced cytotoxicity of the HER2 inhibitors. Hence, NRF2 regulates both HER2 and HER3 receptors to influence cellular responses to HER2 targeting monoclonal antibodies. This deciphered crosstalk mechanism reinforces the role of NRF2 in drug resistance and as a relevant anticancer target. PMID:26770651

  12. HER2-signaling pathway, JNK and ERKs kinases, and cancer stem-like cells are targets of Bozepinib small compound.

    PubMed

    Ramírez, Alberto; Boulaiz, Houria; Morata-Tarifa, Cynthia; Perán, Macarena; Jiménez, Gema; Picon-Ruiz, Manuel; Agil, Ahmad; Cruz-López, Olga; Conejo-García, Ana; Campos, Joaquín M; Sánchez, Ana; García, María A; Marchal, Juan A

    2014-06-15

    Identification of novel anticancer drugs presenting more than one molecular target and efficacy against cancer stem-like cells (CSCs) subpopulations represents a therapeutic need to combat the resistance and the high risk of relapse in patients. In the present work we show how Bozepinib [(RS)-2,6-dichloro-9-[1-(p-nitrobenzenesulfonyl)-1,2,3,5-tetrahydro-4,1-benzoxazepin-3-yl]-9H-purine], a small anti-tumor compound, demonstrated selectivity on cancer cells and showed an inhibitory effect over kinases involved in carcinogenesis, proliferation and angiogenesis. The cytotoxic effects of Bozepinib were observed in both breast and colon cancer cells expressing different receptor patterns. Bozepinib inhibited HER-2 signaling pathway and JNK and ERKs kinases. In addition, Bozepinib has an inhibitory effect on AKT and VEGF together with anti-angiogenic and anti-migratory activities. Moreover, the modulation of pathways involved in tumorigenesis by Bozepinib was also evident in microarrays analysis. Interestingly, Bozepinib inhibited both mamo- and colono-spheres formation and eliminated ALDH+ CSCs subpopulations at a low micromolar range similar to Salinomycin. Bozepinib induced the down-regulation of c-MYC, β-CATENIN and SOX2 proteins and the up-regulation of the GLI-3 hedgehog-signaling repressor. Finally, Bozepinib shows in vivo anti-tumor and anti-metastatic efficacy in xenotransplanted nude mice without presenting sub-acute toxicity. These findings support further studies on the therapeutic potential of Bozepinib in cancer patients. PMID:24946763

  13. HER2-signaling pathway, JNK and ERKs kinases, and cancer stem-like cells are targets of Bozepinib

    PubMed Central

    Ramírez, Alberto; Boulaiz, Houria; Morata-Tarifa, Cynthia; Perán, Macarena; Jiménez, Gema; Picon-Ruiz, Manuel; Agil, Ahmad; Cruz-López, Olga; Conejo-García, Ana; Campos, Joaquín M.; Sánchez, Ana; García, María A.; Marchal, Juan A.

    2014-01-01

    Identification of novel anticancer drugs presenting more than one molecular target and efficacy against cancer stem-like cells (CSCs) subpopulations represents a therapeutic need to combat the resistance and the high risk of relapse in patients. In the present work we show how Bozepinib [(RS)-2,6-dichloro-9-[1-(p-nitrobenzenesulfonyl)-1,2,3,5-tetrahydro-4,1-benzoxazepin-3-yl]-9H-purine], a small anti-tumor compound, demonstrated selectivity on cancer cells and showed an inhibitory effect over kinases involved in carcinogenesis, proliferation and angiogenesis. The cytotoxic effects of Bozepinib were observed in both breast and colon cancer cells expressing different receptor patterns. Bozepinib inhibited HER-2 signaling pathway and JNK and ERKs kinases. In addition, Bozepinib has an inhibitory effect on AKT and VEGF together with anti-angiogenic and anti-migratory activities. Moreover, the modulation of pathways involved in tumorigenesis by Bozepinib was also evident in microarrays analysis. Interestingly, Bozepinib inhibited both mamo- and colono-spheres formation and eliminated ALDH+ CSCs subpopulations at a low micromolar range similar to Salinomycin. Bozepinib induced the down-regulation of c-MYC, β-CATENIN and SOX2 proteins and the up-regulation of the GLI-3 hedgehog-signaling repressor. Finally, Bozepinib shows in vivo anti-tumor and anti-metastatic efficacy in xenotransplanted nude mice without presenting sub-acute toxicity. These findings support further studies on the therapeutic potential of Bozepinib in cancer patients. PMID:24946763

  14. Inhibition of the HER2 pathway by n-3 polyunsaturated fatty acids prevents breast cancer in fat-1 transgenic mice

    PubMed Central

    Zou, Zuquan; Bellenger, Sandrine; Massey, Karen A.; Nicolaou, Anna; Geissler, Audrey; Bidu, Célia; Bonnotte, Bernard; Pierre, Anne-Sophie; Minville-Walz, Mélaine; Rialland, Michaël; Seubert, John; Kang, Jing X.; Lagrost, Laurent; Narce, Michel; Bellenger, Jérôme

    2013-01-01

    Overexpression of the tyrosine kinase receptor, ErbB2/HER2/Neu, occurs in 25–30% of invasive breast cancer (BC) with poor patient prognosis. Due to confounding factors, inconsistencies still remain regarding the protective effects of n-3 polyunsaturated fatty acids (PUFAs) on BC. We therefore evaluated whether fat-1 transgenic mice, endogenously synthesizing n-3 PUFAs from n-6 PUFAs, were protected against BC development, and we then aimed to study in vivo a mechanism potentially involved in such protection. E0771 BC cells were implanted into fat-1 and wild-type (WT) mice. After tumorigenesis examination, we analyzed the expression of proteins involved in the HER2 signaling pathway and lipidomic analyses were performed in tumor tissues and plasma. Our results showed that tumors totally disappeared by day 15 in fat-1 mice but continued to grow in WT mice. This prevention can be related in part to significant repression of the HER2/β-catenin signaling pathway and formation of significant levels of n-3 PUFA-derived bioactive mediators (particularly 15-hydroxyeicosapentaenoic acid, 17-hydroxydocosahexaenoic acid, and prostaglandin E3) in the tumors of fat-1 mice compared with WT mice. All together these data demonstrate an anti-BC effect of n-3 PUFAs through, at least in part, HER2 signaling pathway downregulation, and highlight the importance of gene-diet interactions in BC. PMID:24052576

  15. Cdk4 and Nek2 Signal Binucleation and Centrosome Amplification in a Her2+ Breast Cancer Model

    PubMed Central

    Harrison Pitner, Mary Kathryn; Saavedra, Harold I.

    2013-01-01

    Centrosome amplification (CA) is a contributor to carcinogenesis, generating aneuploidy, and chromosome instability. Previous work shows that breast adenocarcinomas have a higher frequency of centrosome defects compared to normal breast tissues. Abnormal centrosome phenotypes are found in pre-malignant lesions, suggesting an early role in breast carcinogenesis. However, the role of CA in breast cancers remains elusive. Identification of pathways and regulatory molecules involved in the generation of CA is essential to understanding its role in breast tumorigenesis. We established a breast cancer model of CA using Her2-positive cells. Our goal was to identify centrosome cycle molecules that are deregulated by aberrant Her2 signaling and the mechanisms driving CA. Our results show some Her2+ breast cancer cell lines harbor both CA and binucleation. Abolishing the expression of Cdk4 abrogated both CA and binucleation in these cells. We also found the source of binucleation in these cells to be defective cytokinesis that is normalized by downregulation of Cdk4. Protein levels of Nek2 diminish upon Cdk4 knockdown and vice versa, suggesting a molecular connection between Cdk4 and Nek2. Knockdown of Nek2 reduces CA and binucleation in this model while its overexpression further enhances centrosome amplification. We conclude that CA is modulated through Cdk4 and Nek2 signaling and that binucleation is a likely source of CA in Her2+ breast cancer cells. PMID:23776583

  16. The inhibition of early stages of HER-2/neu-mediated mammary carcinogenesis by dietary n-3 polyunsaturated fatty acids

    PubMed Central

    Yee, Lisa D.; Agarwal, Deepak; Rosol, Thomas J.; Lehman, Amy; Tian, Min; Hatton, Jennifer; Cook, Jessica; Belury, Martha A.; Clinton, Steven K.

    2013-01-01

    Scope We previously demonstrated that lifelong feeding of diets enriched in n-3 fatty acids such as docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) significantly inhibits HER-2/neu-mediated mammary tumorigenesis in mice. Of interest is whether dietary n-3 fatty acids exert effects at early stages of mammary carcinogenesis. Methods and results Female 7 week old MMTV-HER-2/neu transgenic mice were randomized to AIN-based semipurified diets containing either fish or corn oil at 25% energy. Mice were evaluated at 25, 30 and 35 weeks with analysis of mammary glands for atypical ductal hyperplasia (hematoxylin and eosin), cell proliferation (Ki67 immunostaining), and fatty acid synthase and cyclooxygenase-2 gene expression (qRT-PCR). Tissue fatty acid profiles were quantitated by gas chromatography. Atypia grade decreased significantly in mice fed fish oil (P=0.002). Mammary epithelial cells in mammary glands from mice fed fish oil also had an 8 fold lower percentage of Ki67 expression. COX-2 expression in mammary fat pads significantly decreased in mice fed fish versus corn oil enriched diets. Conclusions Dietary fish oil inhibits atypical ductal hyperplasia at early stages of HER-2/neu-mediated mammary carcinogenesis relative to corn oil diets. This histologic change is associated with suppression of mammary epithelial cell proliferation and decreased COX-2 expression in mammary tissue. PMID:23213007

  17. HER2 induces cell proliferation and invasion of non-small-cell lung cancer by upregulating COX-2 expression via MEK/ERK signaling pathway

    PubMed Central

    Chi, Feng; Wu, Rong; Jin, Xueying; Jiang, Min; Zhu, Xike

    2016-01-01

    HER2 positivity has been well studied in various cancers, but its importance in non-small-cell lung cancer (NSCLC) is still being explored. In this study, quantitative reverse transcription polymerase chain reaction (qRT-PCR) was performed to detect HER2 and COX-2 expression in NSCLC tissues. Then, pcDNA3.1-HER2 was used to overexpress HER2, while HER2 siRNA and COX-2 siRNA were used to silence HER2 and COX-2 expression. MTT assay and invasion assay were used to detect the effects of HER2 on cell proliferation and invasion. Our study revealed that HER2 and COX-2 expression were upregulated in NSCLC tissues and HER2 exhibited a significant positive correlation with the levels of COX-2 expression. Overexpression of HER2 evidently elevated COX-2 expression, while silencing of HER2 evidently decreased COX-2 expression. Furthermore, overexpressed HER2 induced the ERK phosphorylation, and this was abolished by the treatment with U0126, a pharmacological inhibitor of MEK, an upstream kinase of ERK. HER2-induced expression and promoter activity of COX-2 were also suppressed by U0126, suggesting that the MEK/ERK signaling pathway regulates COX-2 expression. In addition, HER2 induced activation of AKT signaling pathway, which was reversed by pretreatment with U0126 and COX-2 siRNA. MTT and invasion assays revealed that HER2 induced cell proliferation and invasion that were reversed by pretreatment with U0126 and COX-2 siRNA. In this study, our results demonstrated for the first time that HER2 elevated COX-2 expression through the activation of MEK/ERK pathway, which subsequently induced cell proliferation and invasion via AKT pathway in NSCLC tissues. PMID:27217781

  18. A novel double-negative feedback loop between miR-489 and the HER2-SHP2-MAPK signaling axis regulates breast cancer cell proliferation and tumor growth

    PubMed Central

    Lee, Ji Shin; Markoutsa, Eleni; Jie, Chunfa; Liu, Shou; Botbyl, Rachel; Reisman, David; Xu, Peisheng; Chen, Hexin

    2016-01-01

    Human epidermal growth factor receptor 2 (HER2 or ErBb2) is a receptor tyrosine kinase overexpressed in 20-30% of breast cancers and associated with poor prognosis and outcome. Dysregulation of several microRNAs (miRNAs) plays a key role in breast cancer progression and metastasis. In this study, we screened and identified miRNAs dysregualted in HER2-positive breast cancer cells. Our molecular study demonstrated that miR-489 was specifically downregulated by the HER2-downstream signaling, especially through the MAPK pathway. Restoration or overexpression of miR-489 in HER2-positive breast cancer cells significantly inhibited cell growth in vitro and decreased the tumorigenecity and tumor growth in xenograft mice. Mechanistically, we found that overexpression of miR-489 led to the decreased levels of HER2 and SHP2 and thus attenuated HER2-downstream signaling. Furthermore, we for the first time demonstrated that HER2 is a direct target of miR-489 and therefore HER2-SHP2-MAPK and miR-489 signaling pathways form a mutually inhibitory loop. Using quantitative real-time PCR analysis and Fluorescent in situ hybridization technique (FISH), we found that miR-489 was expressed at significantly lower level in tumor tissues compared to the adjacent normal tissues. Downregulation of miR-489 in breast cancers was associated with aggressive tumor phenotypes. Overall, our results define a double-negative feedback loop involving miR-489 and the HER2-SHP2-MAPK signaling axis that can regulate breast cancer cell proliferation and tumor progression and might have therapeutic relevance for HER2-positive breast cancer. PMID:26918448

  19. MicroRNA-7 Inhibits Multiple Oncogenic Pathways to Suppress HER2Δ16 Mediated Breast Tumorigenesis and Reverse Trastuzumab Resistance

    PubMed Central

    Huynh, Felicia C.; Jones, Frank E.

    2014-01-01

    The oncogenic isoform of HER2, HER2Δ16, is expressed with HER2 in nearly 50% of HER2 positive breast tumors where HER2Δ16 drives metastasis and resistance to multiple therapeutic interventions including tamoxifen and trastuzumab. In recent years microRNAs have been shown to influence multiple aspects of tumorigenesis and tumor cell response to therapy. Accordingly, the HER2Δ16 oncogene alters microRNA expression to promote endocrine resistance. With the goal of identifying microRNA suppressors of HER2Δ16 oncogenic activity we investigated the contribution of altered microRNA expression to HER2Δ16 mediated tumorigenesis and trastuzumab resistance. Using a gene array strategy comparing microRNA expression profiles of MCF-7 to MCF-7/HER2Δ16 cells, we found that expression of HER2Δ16 significantly altered expression of 16 microRNAs by 2-fold or more including a 4.8 fold suppression of the miR-7 tumor suppressor. Reestablished expression of miR-7 in the MCF-7/HER2Δ16 cell line caused a G1 cell cycle arrest and reduced both colony formation and cell migration activity to levels of parental MCF-7 cells. Suppression of miR-7 in the MCF-7 cell line resulted in enhanced colony formation activity but not cell migration, indicating that miR-7 suppression is sufficient to drive tumor cell proliferation but not migration. MiR-7 inhibited MCF-7/HER2Δ16 cell migration through a mechanism involving suppression of the miR-7 target gene EGFR. In contrast, miR-7 inhibition of MCF-7/HER2Δ16 cell proliferation involved a pathway where miR-7 expression resulted in the inactivation of Src kinase independent of suppressed EGFR expression. Also independent of EGFR suppression, reestablished miR-7 expression sensitized refractory MCF-7/HER2Δ16 cells to trastuzumab. Our results demonstrate that reestablished miR-7 expression abolishes HER2Δ16 induced cell proliferation and migration while sensitizing HER2Δ16 expressing cells to trastuzumab therapy. We propose that miR-7 regulated

  20. Improved Treatment of Breast Cancer with Anti-HER2 Therapy Requires Interleukin-21 Signaling in CD8+ T Cells.

    PubMed

    Mittal, Deepak; Caramia, Franco; Michiels, Stefan; Joensuu, Heikki; Kellokumpu-Lehtinen, Pirkko-Liisa; Sotiriou, Christos; Loi, Sherene; Smyth, Mark J

    2016-01-15

    The HER2/ErbB2 monoclonal antibody (mAb) trastuzumab is combined with chemotherapy as a standard-of-care for newly diagnosed HER2(+) breast cancer patients, but some patients treated with this combination therapy experience early relapse. Our analysis of data from a clinical trial evaluating the efficacy of chemotherapy plus/minus trastuzumab suggested that the magnitude of trastuzumab benefit on distant disease-free survival was higher for increasing expression of the IL21 receptor (IL21R). Therefore, we investigated a possible role for IL21 signaling in promoting HER2 mAb therapeutic efficacy. We found that IL21R-deficient mice and wild-type mice treated with a neutralizing anti-IL21 mAb were less susceptible to trastuzumab-like anti-ErbB2 therapy. Furthermore, IL21R expression on CD8(+) T cells, but not on natural killer cells, was required for optimal anti-ErbB2 mAb efficacy, and IL21 expression was enhanced in tumor-infiltrating CD4(+) T lymphocytes after anti-ErbB2 therapy. Finally, we found that administering recombinant IL21 in combination with anti-ErbB2 therapy was therapeutic against primary tumors and experimental metastases in mice. Collectively, our findings suggest that elevating IL21 signaling may enhance trastuzumab efficacy, thus constituting a novel candidate strategy to overcome trastuzumab resistance and improve patient survival. Cancer PMID:26744522

  1. Anti-tumor efficacy of BEZ235 is complemented by its anti-angiogenic effects via downregulation of PI3K-mTOR-HIF1alpha signaling in HER2-defined breast cancers

    PubMed Central

    Dey, Nandini; Sun, Yuliang; Carlson, Jennifer H; Wu, Hui; Lin, Xiaoqian; Leyland-Jones, Brian; De, Pradip

    2016-01-01

    with VEGFA pair as well as HIF1alpha with PIK3CA pair in Her2-positive breast tumors (TCGA, cell 2015) were found statistically significant. In xenograft models, BEZ235 blocked tumor growth and decreased Ki67, CD31, p-AKT, p-S6RP, p-4EBP1 IHC-expressions. These decreases were more pronounced when BEZ235 was combined with trastuzumab in HER2+/trastuzumab-sensitive, trastuzumab-resistant and HER2+/PIK3CA mutated models. We demonstrated that combined targeting of HER2 and the PI3K-AKT-mTOR pathway is superior to HER2-directed therapy alone. Mechanistically the inhibition of tumor-induced angiogenesis by BEZ235 caused by the down-regulation of PI3K-mTOR-HIF1alpha signaling irrespective of the trastuzumab-sensitivity status of HER2+ breast cancers proving evidence for the first time that the inhibition of angiogenesis is an important component of the anti-tumor efficacy of BEZ235 in HER2 defined breast cancers. PMID:27186427

  2. Anti-tumor efficacy of BEZ235 is complemented by its anti-angiogenic effects via downregulation of PI3K-mTOR-HIF1alpha signaling in HER2-defined breast cancers.

    PubMed

    Dey, Nandini; Sun, Yuliang; Carlson, Jennifer H; Wu, Hui; Lin, Xiaoqian; Leyland-Jones, Brian; De, Pradip

    2016-01-01

    with VEGFA pair as well as HIF1alpha with PIK3CA pair in Her2-positive breast tumors (TCGA, cell 2015) were found statistically significant. In xenograft models, BEZ235 blocked tumor growth and decreased Ki67, CD31, p-AKT, p-S6RP, p-4EBP1 IHC-expressions. These decreases were more pronounced when BEZ235 was combined with trastuzumab in HER2+/trastuzumab-sensitive, trastuzumab-resistant and HER2+/PIK3CA mutated models. We demonstrated that combined targeting of HER2 and the PI3K-AKT-mTOR pathway is superior to HER2-directed therapy alone. Mechanistically the inhibition of tumor-induced angiogenesis by BEZ235 caused by the down-regulation of PI3K-mTOR-HIF1alpha signaling irrespective of the trastuzumab-sensitivity status of HER2+ breast cancers proving evidence for the first time that the inhibition of angiogenesis is an important component of the anti-tumor efficacy of BEZ235 in HER2 defined breast cancers. PMID:27186427

  3. Araguspongine C induces autophagic death in breast cancer cells through suppression of c-Met and HER2 receptor tyrosine kinase signaling.

    PubMed

    Akl, Mohamed R; Ayoub, Nehad M; Ebrahim, Hassan Y; Mohyeldin, Mohamed M; Orabi, Khaled Y; Foudah, Ahmed I; El Sayed, Khalid A

    2015-01-01

    Receptor tyrosine kinases are key regulators of cellular growth and proliferation. Dysregulations of receptor tyrosine kinases in cancer cells may promote tumorigenesis by multiple mechanisms including enhanced cell survival and inhibition of cell death. Araguspongines represent a group of macrocyclic oxaquinolizidine alkaloids isolated from the marine sponge Xestospongia species. This study evaluated the anticancer activity of the known oxaquinolizidine alkaloids araguspongines A, C, K and L, and xestospongin B against breast cancer cells. Araguspongine C inhibited the proliferation of multiple breast cancer cell lines in vitro in a dose-dependent manner. Interestingly, araguspongine C-induced autophagic cell death in HER2-overexpressing BT-474 breast cancer cells was characterized by vacuole formation and upregulation of autophagy markers including LC3A/B, Atg3, Atg7, and Atg16L. Araguspongine C-induced autophagy was associated with suppression of c-Met and HER2 receptor tyrosine kinase activation. Further in-silico docking studies and cell-free Z-LYTE assays indicated the potential of direct interaction between araguspongine C and the receptor tyrosine kinases c-Met and HER2 at their kinase domains. Remarkably, araguspongine C treatment resulted in the suppression of PI3K/Akt/mTOR signaling cascade in breast cancer cells undergoing autophagy. Induction of autophagic death in BT-474 cells was also associated with decreased levels of inositol 1,4,5-trisphosphate receptor upon treatment with effective concentration of araguspongine C. In conclusion, results of this study are the first to reveal the potential of araguspongine C as an inhibitor to receptor tyrosine kinases resulting in the induction of autophagic cell death in breast cancer cells. PMID:25580621

  4. Rapamycin Inhibits Multiple Stages of c-Neu/ErbB2-induced Tumor Progression in a Transgenic Mouse Model of HER2 Positive Breast Cancer

    PubMed Central

    Mosley, Jonathan D.; Poirier, John T.; Seachrist, Darcie D.; Landis, Melissa D.; Keri, Ruth A.

    2008-01-01

    Amplification of the HER2 (ErbB2, c-Neu) proto-oncogene in breast cancer is associated with poor prognosis and high relapse rates. HER2/ErbB2, in conjunction with ErbB3, signals through the Akt/PI3-K pathway and leads to the activation of mTOR, a critical mRNA translation regulator that controls cell growth. Gene expression analysis of mammary tumors collected from MMTV-c-Neu transgenic mice revealed that mRNA levels of several mTOR pathway members were either up-regulated (p85/PI3-K and p70S6K) or down-regulated (eIF4E-BP1) in a manner expected to enhance signaling through this pathway. Treatment of MMTV-c-Neu transgenic mice with the mTOR inhibitor rapamycin caused growth arrest and regression of primary tumors with no evidence of weight loss or generalized toxicity. The treatment effects were due to decreased proliferation, associated with reduced cyclin D1 expression, and increased cell death in primary tumors. While many of the dead epithelial cells had the histopathologic characteristics of ischemic necrosis, rapamycin treatment was not associated with changes in microvascular density or apoptosis. Rapamycin also inhibited cellular proliferation in lung metastases. In summary, data from this preclinical model of ErbB2/Neu-induced breast cancer demonstrate that inhibition of the mTOR pathway with rapamycin blocks multiple stages of ErbB2/Neu-induced tumorigenic progression. PMID:17699716

  5. An Epigenetic Pathway Regulates Sensitivity of Breast Cancer Cells to HER2 Inhibition via FOXO/c-Myc Axis

    PubMed Central

    Matkar, Smita; Sharma, Paras; Gao, Shubin; Gurung, Buddha; Katona, Bryson W; Liao, Jennifer; Muhammad, Abdul Bari; Kong, Xiang-Cheng; Wang, Lei; Jin, Guanghui; Dang, Chi; Hua, Xianxin

    2016-01-01

    SUMMARY Human epidermal growth factor receptor 2 (HER2) is upregulated in a subset of human breast cancers. However, the cancer cells often quickly develop an adaptive response to HER2 kinase inhibitors. We found that an epigenetic pathway involving MLL2 is crucial for growth of HER2+ cells and MLL2 reduces sensitivity of the cancer cells to a HER2 inhibitor, Lapatinib. Lapatinib-induced FOXO transcription factors, normally tumor-suppressing, paradoxically upregulate c-Myc epigenetically, in concert with a cascade of MLL2-associating epigenetic regulators, to dampen sensitivity of the cancer cells to Lapatinib. An epigenetic inhibitor suppressing c-Myc synergizes with Lapatinib to suppress cancer growth in vivo, partly by repressing the FOXO/c-Myc axis, unraveling an epigenetically regulated FOXO/c-Myc axis as a potential target to improve therapy. PMID:26461093

  6. Trastuzumab has preferential activity against breast cancers driven by HER2 homodimers

    PubMed Central

    Ghosh, Ritwik; Narasanna, Archana; Wang, Shizhen Emily; Liu, Shuying; Chakrabarty, Anindita; Balko, Justin M.; González-Angulo, Ana María; Mills, Gordon B.; Penuel, Elicia; Winslow, John; Sperinde, Jeff; Dua, Rajiv; Pidaparthi, Sailaja; Mukherjee, Ali; Leitzel, Kim; Kostler, Wolfgang J.; Lipton, Allan; Bates, Michael; Arteaga, Carlos L.

    2011-01-01

    In breast cancer cells with HER2 gene amplification, HER2 receptors exist on the cell surface as monomers, homodimers and heterodimers with EGFR/HER3. The therapeutic antibody trastuzumab, an approved therapy for HER2+ breast cancer, cannot block ligand-induced HER2 heterodimers, suggesting it cannot effectively inhibit HER2 signaling. Hence, HER2 oligomeric states may predict the odds of a clinical response to trastuzumab in HER2-driven tumors. To test this hypothesis, we generated non-transformed human MCF10A mammary epithelial cells stably expressing a chimeric HER2-FKBP molecule that could be conditionally induced to homodimerize by adding the FKBP ligand AP1510, or instead induced to heterodimerize with EGFR or HER3 by adding the heterodimer ligands EGF/TGFα or heregulin. AP1510, EGF, and heregulin each induced growth of MCF10A cells expressing HER2-FKBP. As expected, trastuzumab inhibited homodimer-mediated but not heterodimer-mediated cell growth. In contrast, the HER2 antibody pertuzumab, which blocks HER2 heterodimerization, inhibited growth induced by heregulin but not AP1510. Lastly, HER2/EGFR tyrosine kinase inhibitor lapatinib blocked both homodimer- and heterodimer-induced growth. AP1510 triggered phosphorylation of Erk1/2 but not AKT, whereas trastuzumab inhibited AP1510-induced Erk1/2 phosphorylation and Shc-HER2 homodimer binding, but not TGFα-induced AKT phosphorylation. Consistent with these observations, high levels of HER2 homodimers correlated with longer time to progression following trastuzumab therapy in a cohort of HER2-overexpressing patients. Together, our findings corroborate the hypothesis that HER2 oligomeric states regulate HER2 signaling, also arguing that trastuzumab sensitivity of homodimers reflects an inability to activate the PI3K/AKT pathway. One of the most important clinical implications of our results is that high levels of HER2 homodimers may predict a positive response to trastuzumab. PMID:21324925

  7. Trastuzumab has preferential activity against breast cancers driven by HER2 homodimers.

    PubMed

    Ghosh, Ritwik; Narasanna, Archana; Wang, Shizhen Emily; Liu, Shuying; Chakrabarty, Anindita; Balko, Justin M; González-Angulo, Ana María; Mills, Gordon B; Penuel, Elicia; Winslow, John; Sperinde, Jeff; Dua, Rajiv; Pidaparthi, Sailaja; Mukherjee, Ali; Leitzel, Kim; Kostler, Wolfgang J; Lipton, Allan; Bates, Michael; Arteaga, Carlos L

    2011-03-01

    In breast cancer cells with HER2 gene amplification, HER2 receptors exist on the cell surface as monomers, homodimers, and heterodimers with EGFR/HER3. The therapeutic antibody trastuzumab, an approved therapy for HER2(+) breast cancer, cannot block ligand-induced HER2 heterodimers, suggesting it cannot effectively inhibit HER2 signaling. Hence, HER2 oligomeric states may predict the odds of a clinical response to trastuzumab in HER2-driven tumors. To test this hypothesis, we generated nontransformed human MCF10A mammary epithelial cells stably expressing a chimeric HER2-FKBP molecule that could be conditionally induced to homodimerize by adding the FKBP ligand AP1510, or instead induced to heterodimerize with EGFR or HER3 by adding the heterodimer ligands EGF/TGFα or heregulin. AP1510, EGF, and heregulin each induced growth of MCF10A cells expressing HER2-FKBP. Trastuzumab inhibited homodimer-mediated but not heterodimer-mediated cell growth. In contrast, the HER2 antibody pertuzumab, which blocks HER2 heterodimerization, inhibited growth induced by heregulin but not AP1510. Lastly, the HER2/EGFR tyrosine kinase inhibitor lapatinib blocked both homodimer- and heterodimer-induced growth. AP1510 triggered phosphorylation of Erk1/2 but not AKT, whereas trastuzumab inhibited AP1510-induced Erk1/2 phosphorylation and Shc-HER2 homodimer binding, but not TGFα-induced AKT phosphorylation. Consistent with these observations, high levels of HER2 homodimers correlated with longer time to progression following trastuzumab therapy in a cohort of patients with HER2-overexpressing breast cancer. Together, our findings confirm the notion that HER2 oligomeric states regulate HER2 signaling, also arguing that trastuzumab sensitivity of homodimers may reflect their inability to activate the PI3K (phosphoinositide 3-kinase)/AKT pathway. A clinical implication of our results is that high levels of HER2 homodimers may predict a positive response to trastuzumab. PMID:21324925

  8. Recombinant λ bacteriophage displaying nanobody towards third domain of HER-2 epitope inhibits proliferation of breast carcinoma SKBR-3 cell line.

    PubMed

    Shoae-Hassani, Alireza; Mortazavi-Tabatabaei, Seyed Abdolreza; Sharif, Shiva; Madadi, Shabnam; Rezaei-Khaligh, Hamidreza; Verdi, Javad

    2013-02-01

    Phage display of many nanobodies via filamentous phage in combination with helper phage has been reported by many scientists. The aim of this study was to produce lambda (λ) bacteriophage displaying high-affinity nanobody against HER-2 expressing breast carcinoma cells. Bacteriophage λ is a temperate phage with inherent biological safety in mammalian cells. Here we report the construction of a recombinant λ phage that efficiently expresses specific nanobody towards third domain of HER-2 target on SKBR-3 and MCF-7 cell lines in vitro. We constructed recombinant λ phage particles containing a mammalian expression cassette, C-Myc tagged, encoding VHH gene of camelid anti HER-2 third domain epitope using λ ZAP-cytomegalic virus (CMV) vector. The SKBR-3, MCF-7 and human endometrial stem cells were treated by the nanobody displayed recombinant λ phage. The cell growth inhibition assay was performed by MTT Cell Viability Assay Kit. After the fourth round of biopanning there was a significant enrichment in the phage specifically binding to the antigen. The ratio of targeted phage increased approximately 1,000-fold in the fifth round. The nanobody expressed by λ ZAP-CMV-VHH phagemid cloned in λ bioparticles significantly inhibited the proliferation of HER-2 positive SKBR-3 and MCF-7 cells. Recombinant bacteriophage λ ZAP-CMV-VHH-cDNA could be used efficiently for construction of nanobodies to mortify HER-2 positive breast carcinoma cells as a nanomedical therapeutic. PMID:23224340

  9. HER2 activating mutations are targets for colorectal cancer treatment

    PubMed Central

    Kavuri, Shyam M.; Jain, Naveen; Galimi, Francesco; Cottino, Francesca; Leto, Simonetta M.; Migliardi, Giorgia; Searleman, Adam C.; Shen, Wei; Monsey, John; Trusolino, Livio; Jacobs, Samuel A.; Bertotti, Andrea; Bose, Ron

    2015-01-01

    The Cancer Genome Atlas project identified HER2 somatic mutations and gene amplification in 7% of colorectal cancer patients. Introduction of the HER2 mutations, S310F, L755S, V777L, V842I, and L866M, into colon epithelial cells increased signaling pathways and anchorage-independent cell growth, indicating that they are activating mutations. Introduction of these HER2 activating mutations into colorectal cancer cell lines produced resistance to cetuximab and panitumumab by sustaining MAPK phosphorylation. HER2 mutations are potently inhibited by low nanomolar doses of the irreversible tyrosine kinase inhibitors, neratinib and afatinib. HER2 gene sequencing of 48 cetuximab resistant, quadruple (KRAS, NRAS, BRAF, and PIK3CA) WT colorectal cancer patient-derived xenografts (PDX’s) identified 4 PDX’s with HER2 mutations. HER2 targeted therapies were tested on two PDX’s. Treatment with a single HER2 targeted drug (trastuzumab, neratinib, or lapatinib) delayed tumor growth, but dual HER2 targeted therapy with trastuzumab plus tyrosine kinase inhibitors produced regression of these HER2 mutated PDX’s. PMID:26243863

  10. Synergistic inhibition with a dual epidermal growth factor receptor/HER-2/neu tyrosine kinase inhibitor and a disintegrin and metalloprotease inhibitor.

    PubMed

    Witters, Lois; Scherle, Peggy; Friedman, Steven; Fridman, Jordan; Caulder, Eian; Newton, Robert; Lipton, Allan

    2008-09-01

    The ErbB family of receptors is overexpressed in numerous human tumors. Overexpression correlates with poor prognosis and resistance to therapy. Use of ErbB-specific antibodies to the receptors (Herceptin or Erbitux) or ErbB-specific small-molecule inhibitors of the receptor tyrosine kinase activity (Iressa or Tarceva) has shown clinical efficacy in several solid tumors. An alternative method of affecting ErbB-initiated tumor growth and survival is to block sheddase activity. Sheddase activity is responsible for cleavage of multiple ErbB ligands and receptors, a necessary step in availability of the soluble, active form of the ligand and a constitutively activated ligand-independent receptor. This sheddase activity is attributed to the ADAM (a disintegrin and metalloprotease) family of proteins. ADAM 10 is the main sheddase of epidermal growth factor (EGF) and HER-2/neu cleavage, whereas ADAM17 is required for cleavage of additional EGF receptor (EGFR) ligands (transforming growth factor-alpha, amphiregulin, heregulin, heparin binding EGF-like ligand). This study has shown that addition of INCB3619, a potent inhibitor of ADAM10 and ADAM17, reduces in vitro HER-2/neu and amphiregulin shedding, confirming that it interferes with both HER-2/neu and EGFR ligand cleavage. Combining INCB3619 with a lapatinib-like dual inhibitor of EGFR and HER-2/neu kinases resulted in synergistic growth inhibition in MCF-7 and HER-2/neu-transfected MCF-7 human breast cancer cells. Combining the INCB7839 second-generation sheddase inhibitor with lapatinib prevented the growth of HER-2/neu-positive BT474-SC1 human breast cancer xenografts in vivo. These results suggest that there may be an additional clinical benefit of combining agents that target the ErbB pathways at multiple points. PMID:18757423

  11. Valproic acid inhibits proliferation of HER2-expressing breast cancer cells by inducing cell cycle arrest and apoptosis through Hsp70 acetylation

    PubMed Central

    MAWATARI, TOSHIKI; NINOMIYA, ITASU; INOKUCHI, MASAFUMI; HARADA, SHINICHI; HAYASHI, HIRONORI; OYAMA, KATSUNOBU; MAKINO, ISAMU; NAKAGAWARA, HISATOSHI; MIYASHITA, TOMOHARU; TAJIMA, HIDEHIRO; TAKAMURA, HIROYUKI; FUSHIDA, SACHIO; OHTA, TETSUO

    2015-01-01

    Breast cancer encompasses a heterogeneous group of diseases at the molecular level. It is known that chemo-sensitivity of breast cancer depends on its molecular subtype. We investigated the growth inhibitory effect of valproic acid (VPA), a histone deacetylase (HDAC) inhibitor, and the mechanism of this inhibition on four breast cancer cell lines with different molecular subtypes. The growth inhibitory effect of VPA in the four different breast cancer cell lines was investigated. The alteration of levels of p21 WAF1, cleaved caspase-3, acetylated Heat shock protein (Hsp) 90, acetylated Hsp70, and acetylated α-tubulin by VPA was examined in VPA-sensitive, human epidermal receptor 2 (HER2)-overexpressing SKBR3 cells. The cell growth inhibition of breast cancer cell lines was dependent on the dose and exposure time of VPA. The cell growth of HER2-overexpressing SKBR3 cell line was inhibited by VPA to a much greater degree than other cell lines studied. In SKBR3 cell line, VPA upregulated expression of p21 WAF1 and cleaved caspase-3 in the early phase. VPA markedly increased Hsp70 acetylation in a time-dependent manner but did not increase Hsp90 acetylation. Our data demonstrated that VPA inhibited cell proliferation and induced cell cycle arrest and apoptosis of HER2-overexpressing breast cancer cells. This anti-proliferation effect might be the direct function of VPA as an HDAC inhibitor. We propose an alternative mechanism whereby acetylation of Hsp70 disrupts the function of Hsp90 and leads to downregulation of its client proteins, including HER2 that might be the indirect function of VPA, in the sense that non-histone proteins are acetylated. PMID:26497673

  12. Essential role of Her3 in two signaling transduction patterns: Her2/Her3 and MET/Her3 in proliferation of human gastric cancer.

    PubMed

    Yun, Chen; Gang, Li; Rongmin, Gu; Xu, Wen; Xuezhi, Ming; Huanqiu, Chen

    2015-12-01

    Various receptor tyrosine kinase (RTK) pathways were verified in many cancers including gastric cancer (GC), We sought to investigate the expression of RTKs including Her2, Her3, and Met and their transduction patterns in human GC. Over-expression of Her2, Her3, and c-Met in human GC was verified by immunohistochemistry leading to constitutive activation of RTK signaling pathways. Combined RTKs expression was valuable indicators for poor prognosis of GC patients. Using ErbB2 specific inhibitor Lapatinib and c-Met specific inhibitor PHA-665752, we further demonstrated that this constitutive activation of RTK signaling is necessary for the survival of GC cells. However, various RTK pattern: Her3/Her2 and Met/Her3 were verified in the transduction growth stimulus from outside via both AKT and MAPK signaling. Moreover, the essential roles of Her3 in both two heterodimers were obtained which showed significantly attenuated growth effect due to Her3 knockdown both in vitro and in vivo. In conclusion, various molecular transduction patterns: Her2/Her3 and Met/Her3 were verified in human GC, and Her3 could serve as a potential target in GC treatment. PMID:25400108

  13. The role of HER2 in cancer therapy and targeted drug delivery

    PubMed Central

    Tai, Wanyi; Mahato, Rubi; Cheng, Kun

    2010-01-01

    HER2 is highly expressed in a significant proportion of breast cancer, ovarian cancer, and gastric cancer. Since the discovery of its role in tumorigenesis, HER2 has received great attention in cancer research during the past two decades. Successful development of the humanized monoclonal anti-HER2 antibody (Trastuzumab) for the treatment of breast cancer further spurred scientists to develop various HER2 specific antibodies, dimerization inhibitors and kinase inhibitors for cancer therapy. On the other hand, the high expression of HER2 and the accessibility of its extracellular domain make HER2 an ideal target for the targeted delivery of anti-tumor drugs as well as imaging agents. Although there is no natural ligand for HER2, various artificial ligands targeting HER2 have been developed and applied in various targeted drug delivery systems. The emphasis of this review is to elucidate the roles of HER2 in cancer therapy and targeted drug delivery. The structure and signal pathway of HER2 will be briefly described. The role of HER2 in tumorigenesis and its relationship with other tumor markers will be discussed. For the HER2 targeted cancer therapy, numerous strategies including the blockage of receptor dimerization, inhibition of the tyrosine kinase activity, and interruption of the downstream signal pathway will be summarized. For the targeted drug delivery to HER2 positive tumor cells, various targeting ligands and their delivery systems will be described in details. PMID:20385184

  14. Overcoming resistance and restoring sensitivity to HER2-targeted therapies in breast cancer

    PubMed Central

    Mohd Sharial, M. S. N.; Crown, J.; Hennessy, B. T.

    2012-01-01

    Background Approximately 15%–23% of breast cancers overexpress human epidermal growth factor receptor 2 (HER2), which leads to the activation of signaling pathways that stimulate cell proliferation and survival. HER2-targeted therapy has substantially improved outcomes in patients with HER2-positive breast cancer. However, both de novo and acquired resistance are observed. Design A literature search was performed to identify proposed mechanisms of resistance to HER2-targeted therapy and identified novel targets in clinical development for treating HER2-resistant disease. Results Proposed HER2-resistance mechanisms include impediments to HER2-inhibitor binding, signaling through alternative pathways, upregulation of signaling pathways downstream of HER2, and failure to elicit an appropriate immune response. Although continuing HER2 inhibition beyond progression may provide an additional clinical benefit, the availability of novel therapies targeting different mechanisms of action could improve outcomes. The developmental strategy with the most available data is targeting the phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin (mTOR) pathway. The oral mTOR inhibitor everolimus has shown promising activity in combination with chemotherapy and trastuzumab in trastuzumab-refractory, advanced breast cancer. Conclusions Non-HER2-targeted therapy is a promising means of overcoming resistance to HER2-targeted treatment. Ongoing clinical studies will provide additional information on the efficacy and safety of novel targeted therapies in HER2-resistant advanced breast cancer. PMID:22865781

  15. HER2 Dimerization Inhibitor Pertuzumab – Mode of Action and Clinical Data in Breast Cancer

    PubMed Central

    Harbeck, Nadia; Beckmann, Matthias W.; Rody, Achim; Schneeweiss, Andreas; Müller, Volkmar; Fehm, Tanja; Marschner, Norbert; Gluz, Oleg; Schrader, Iris; Heinrich, Georg; Untch, Michael; Jackisch, Christian

    2013-01-01

    Summary The humanized monoclonal antibody pertuzumab prevents the dimerization of HER2 with other HER receptors, in particular the pairing of the most potent signaling heterodimer HER2/HER3, thus providing a potent strategy for dual HER2 inhibition. It binds to the extracellular domain of HER2 at a different epitope than trastuzumab. Pertuzumab and trastuzumab act in a complementary fashion and provide a more complete blockade of HER2-mediated signal transduction than either agent alone. Phase II studies demonstrated that pertuzumab was generally well tolerated as a single agent or in combination with trastuzumab and/or cytotoxic agents, and implied an improved clinical efficacy of the combination of pertuzumab and trastuzumab in early and advanced HER2-positive breast cancer. Results of the pivotal phase III study CLEOPATRA in patients with HER2-positive metastatic breast cancer demonstrated that the addition of pertuzumab to first-line combination therapy with docetaxel and trastuzumab significantly prolonged progression-free and overall survival without increasing cardiac toxicity. Currently, the combination of both antibodies is being explored in the palliative setting as well as in the treatment of early HER2-positive breast cancer. Dual HER2 inhibition with the HER2 dimerization inhibitor pertuzumab and trastuzumab may change clinical practice in HER2-positive first-line metastatic breast cancer treatment. PMID:24715843

  16. HER2 Dimerization Inhibitor Pertuzumab - Mode of Action and Clinical Data in Breast Cancer.

    PubMed

    Harbeck, Nadia; Beckmann, Matthias W; Rody, Achim; Schneeweiss, Andreas; Müller, Volkmar; Fehm, Tanja; Marschner, Norbert; Gluz, Oleg; Schrader, Iris; Heinrich, Georg; Untch, Michael; Jackisch, Christian

    2013-03-01

    The humanized monoclonal antibody pertuzumab prevents the dimerization of HER2 with other HER receptors, in particular the pairing of the most potent signaling heterodimer HER2/HER3, thus providing a potent strategy for dual HER2 inhibition. It binds to the extracellular domain of HER2 at a different epitope than trastuzumab. Pertuzumab and trastuzumab act in a complementary fashion and provide a more complete blockade of HER2-mediated signal transduction than either agent alone. Phase II studies demonstrated that pertuzumab was generally well tolerated as a single agent or in combination with trastuzumab and/or cytotoxic agents, and implied an improved clinical efficacy of the combination of pertuzumab and trastuzumab in early and advanced HER2-positive breast cancer. Results of the pivotal phase III study CLEOPATRA in patients with HER2-positive metastatic breast cancer demonstrated that the addition of pertuzumab to first-line combination therapy with docetaxel and trastuzumab significantly prolonged progression-free and overall survival without increasing cardiac toxicity. Currently, the combination of both antibodies is being explored in the palliative setting as well as in the treatment of early HER2-positive breast cancer. Dual HER2 inhibition with the HER2 dimerization inhibitor pertuzumab and trastuzumab may change clinical practice in HER2-positive first-line metastatic breast cancer treatment. PMID:24715843

  17. The Huntington disease protein accelerates breast tumour development and metastasis through ErbB2/HER2 signalling

    PubMed Central

    Moreira Sousa, Cristovão; McGuire, John Russel; Thion, Morgane Sonia; Gentien, David; de la Grange, Pierre; Tezenas du Montcel, Sophie; Vincent-Salomon, Anne; Durr, Alexandra; Humbert, Sandrine

    2013-01-01

    In Huntington disease (HD), polyglutamine expansion in the huntingtin protein causes specific neuronal death. The consequences of the presence of mutant huntingtin in other tissues are less well understood. Here we propose that mutant huntingtin influences breast cancer progression. Indeed, we show that mammary tumours appear earlier in mouse breast cancer models expressing mutant huntingtin as compared to control mice expressing wild-type huntingtin. Tumours bearing mutant huntingtin have a modified gene expression pattern that reflects enhanced aggressiveness with the overexpression of genes favouring invasion and metastasis. In agreement, mutant huntingtin accelerates epithelial to mesenchymal transition and enhances cell motility and invasion. Also, lung metastasis is higher in HD conditions than in control mice. Finally, we report that in HD, the dynamin dependent endocytosis of the ErbB2/HER2 receptor tyrosine kinase is reduced. This leads to its accumulation and to subsequent increases in cell motility and proliferation. Our study may thus have important implications for both cancer and HD. PMID:23300147

  18. HER2+ Cancer Cell Dependence on PI3K vs. MAPK Signaling Axes Is Determined by Expression of EGFR, ERBB3 and CDKN1B

    PubMed Central

    Lahdenranta, Johanna; Onsum, Matthew D.; Nielsen, Ulrik B.; Schoeberl, Birgit; McDonagh, Charlotte F.

    2016-01-01

    Understanding the molecular pathways by which oncogenes drive cancerous cell growth, and how dependence on such pathways varies between tumors could be highly valuable for the design of anti-cancer treatment strategies. In this work we study how dependence upon the canonical PI3K and MAPK cascades varies across HER2+ cancers, and define biomarkers predictive of pathway dependencies. A panel of 18 HER2+ (ERBB2-amplified) cell lines representing a variety of indications was used to characterize the functional and molecular diversity within this oncogene-defined cancer. PI3K and MAPK-pathway dependencies were quantified by measuring in vitro cell growth responses to combinations of AKT (MK2206) and MEK (GSK1120212; trametinib) inhibitors, in the presence and absence of the ERBB3 ligand heregulin (NRG1). A combination of three protein measurements comprising the receptors EGFR, ERBB3 (HER3), and the cyclin-dependent kinase inhibitor p27 (CDKN1B) was found to accurately predict dependence on PI3K/AKT vs. MAPK/ERK signaling axes. Notably, this multivariate classifier outperformed the more intuitive and clinically employed metrics, such as expression of phospho-AKT and phospho-ERK, and PI3K pathway mutations (PIK3CA, PTEN, and PIK3R1). In both cell lines and primary patient samples, we observed consistent expression patterns of these biomarkers varies by cancer indication, such that ERBB3 and CDKN1B expression are relatively high in breast tumors while EGFR expression is relatively high in other indications. The predictability of the three protein biomarkers for differentiating PI3K/AKT vs. MAPK dependence in HER2+ cancers was confirmed using external datasets (Project Achilles and GDSC), again out-performing clinically used genetic markers. Measurement of this minimal set of three protein biomarkers could thus inform treatment, and predict mechanisms of drug resistance in HER2+ cancers. More generally, our results show a single oncogenic transformation can have differing

  19. The positive is inside the negative: HER2-negative tumors can express the HER2 intracellular domain and present a HER2-positive phenotype.

    PubMed

    Panis, Carolina; Pizzatti, Luciana; Corrêa, Stephany; Binato, Renata; Lemos, Gabriela Ferreira; Herrera, Ana Cristina da Silva do Amaral; Seixas, Teresa Fernandes; Cecchini, Rubens; Abdelhay, Eliana

    2015-02-01

    Overexpression of human epithelial growth factor receptor 2 (HER2) is a poor prognostic factor in breast cancer. HER2 is a transmembrane receptor comprising an extracellular domain (ECD), a single transmembrane domain, and an intracellular domain (ICD) with tyrosine-kinase activity. Receptor dimerization triggers pivotal effector pathways in cancer, such as phosphatidylinositol 3-kinase (PI3K) signaling. Currently, screening of HER2 in breast tumors for prognostic and therapeutic purposes involves immunohistochemical (IHC) phenotyping for the ECD, in which tumors with IHC scores below 2+ are reported as HER2-negative. We used a label-free liquid chromatography-mass spectrometry (LC-MS) proteomic approach to compare plasma samples from patients with HER2-positive breast tumors and patients with HER2-negative tumors. Patients with HER2-negative tumors expressed higher circulating levels of calpain-10 than patients with HER2-positive tumors. Calpains cleave HER2, releasing its ECD and transforming phenotypically positive tumors into phenotypically negative tumors. Therefore, we investigated the expression of the ICD in HER2-negative samples that overexpressed calpain-10. We found that 16% of HER2-negative tumors were positive for HER2-ICD, which was associated with circulating HER2-ECD. HER2 gene amplification was also observed in some HER2-negative tumors. Positive staining for the PI3K pathway was observed in the HER2-negative, ICD-positive tumors, similar to the HER2-positive cohort. Microarray analysis revealed that HER2-negative, ICD-positive samples clustered between HER2-positive tumors and triple-negative tumors. Survival analysis revealed that outcome in women with HER2-negative, ICD-positive tumors was better than in women bearing HER2-negative, ICD-negative (triple negative) tumors but was quite similar to HER2-positive tumors and worse than women with luminal A tumors. Moreover, in vitro analyses revealed that MDA-MB 231, a triple negative cell line

  20. Cell surface interaction of annexin A2 and galectin-3 modulates epidermal growth factor receptor signaling in Her-2 negative breast cancer cells.

    PubMed

    Shetty, Praveenkumar; Bargale, Anil; Patil, Basavraj R; Mohan, Rajashekar; Dinesh, U S; Vishwanatha, Jamboor K; Gai, Pramod B; Patil, Vidya S; Amsavardani, T S

    2016-01-01

    Overexpression and activation of tyrosine kinase receptors like EGFR and Src regulate the progression and metastasis of Her-2 negative breast cancer. Recently we have reported the role of cell membrane interaction of phospholipid-binding protein annexin A2 (AnxA2) and EGFR in regulating cellular signaling in the activation of angiogenesis, matrix degradation, invasion, and cancer metastasis. Beta-galactoside-specific animal lectin galectin-3 is an apoptosis inhibitor, and cell surface-associated extracellular galectin-3 also has a role in cell migration, cancer progression, and metastasis. Similar expression pattern and membrane co-localization of these two proteins made us to hypothesize in the current study that galectin-3 and AnxA2 interaction is critical for Her-2 negative breast cancer progression. By various experimental analyses, we confirm that glycosylated AnxA2 at the membrane surface interacts with galectin-3. N-linked glycosylation inhibitor tunicamycin treatment convincingly blocked AnxA2 membrane translocation and its association with galectin-3. To analyze whether this interaction has any functional relevance, we tried to dissociate this interaction with purified plant lectin from chickpea (Cicer arietinum agglutinin). This highly specific 30 kDa plant lectin could dissociate AnxA2 from endogenous lectin galectin-3 interaction at the cell surface. This dissociation could down-regulate Bcl-2 family proteins, cell proliferation, and migration simultaneously triggering cell apoptosis. Targeting this interaction of membrane surface glycoprotein and its animal lectin in Her-2 negative breast cancer may be of therapeutic value. PMID:26438086

  1. The catalytic region and PEST domain of PTPN18 distinctly regulate the HER2 phosphorylation and ubiquitination barcodes.

    PubMed

    Wang, Hong-Mei; Xu, Yun-Fei; Ning, Shang-Lei; Yang, Du-Xiao; Li, Yi; Du, Yu-Jie; Yang, Fan; Zhang, Ya; Liang, Nan; Yao, Wei; Zhang, Ling-Li; Gu, Li-Chuan; Gao, Cheng-Jiang; Pang, Qi; Chen, Yu-Xin; Xiao, Kun-Hong; Ma, Rong; Yu, Xiao; Sun, Jin-Peng

    2014-09-01

    The tyrosine phosphorylation barcode encoded in C-terminus of HER2 and its ubiquitination regulate diverse HER2 functions. PTPN18 was reported as a HER2 phosphatase; however, the exact mechanism by which it defines HER2 signaling is not fully understood. Here, we demonstrate that PTPN18 regulates HER2-mediated cellular functions through defining both its phosphorylation and ubiquitination barcodes. Enzymologic characterization and three crystal structures of PTPN18 in complex with HER2 phospho-peptides revealed the molecular basis for the recognition between PTPN18 and specific HER2 phosphorylation sites, which assumes two distinct conformations. Unique structural properties of PTPN18 contribute to the regulation of sub-cellular phosphorylation networks downstream of HER2, which are required for inhibition of HER2-mediated cell growth and migration. Whereas the catalytic domain of PTPN18 blocks lysosomal routing and delays the degradation of HER2 by dephosphorylation of HER2 on pY(1112), the PEST domain of PTPN18 promotes K48-linked HER2 ubiquitination and its rapid destruction via the proteasome pathway and an HER2 negative feedback loop. In agreement with the negative regulatory role of PTPN18 in HER2 signaling, the HER2/PTPN18 ratio was correlated with breast cancer stage. Taken together, our study presents a structural basis for selective HER2 dephosphorylation, a previously uncharacterized mechanism for HER2 degradation and a novel function for the PTPN18 PEST domain. The new regulatory role of the PEST domain in the ubiquitination pathway will broaden our understanding of the functions of other important PEST domain-containing phosphatases, such as LYP and PTPN12. PMID:25081058

  2. The catalytic region and PEST domain of PTPN18 distinctly regulate the HER2 phosphorylation and ubiquitination barcodes

    PubMed Central

    Wang, Hong-Mei; Xu, Yun-Fei; Ning, Shang-Lei; Yang, Du-Xiao; Li, Yi; Du, Yu-Jie; Yang, Fan; Zhang, Ya; Liang, Nan; Yao, Wei; Zhang, Ling-Li; Gu, Li-Chuan; Gao, Cheng-Jiang; Pang, Qi; Chen, Yu-Xin; Xiao, Kun-Hong; Ma, Rong; Yu, Xiao; Sun, Jin-Peng

    2014-01-01

    The tyrosine phosphorylation barcode encoded in C-terminus of HER2 and its ubiquitination regulate diverse HER2 functions. PTPN18 was reported as a HER2 phosphatase; however, the exact mechanism by which it defines HER2 signaling is not fully understood. Here, we demonstrate that PTPN18 regulates HER2-mediated cellular functions through defining both its phosphorylation and ubiquitination barcodes. Enzymologic characterization and three crystal structures of PTPN18 in complex with HER2 phospho-peptides revealed the molecular basis for the recognition between PTPN18 and specific HER2 phosphorylation sites, which assumes two distinct conformations. Unique structural properties of PTPN18 contribute to the regulation of sub-cellular phosphorylation networks downstream of HER2, which are required for inhibition of HER2-mediated cell growth and migration. Whereas the catalytic domain of PTPN18 blocks lysosomal routing and delays the degradation of HER2 by dephosphorylation of HER2 on pY1112, the PEST domain of PTPN18 promotes K48-linked HER2 ubiquitination and its rapid destruction via the proteasome pathway and an HER2 negative feedback loop. In agreement with the negative regulatory role of PTPN18 in HER2 signaling, the HER2/PTPN18 ratio was correlated with breast cancer stage. Taken together, our study presents a structural basis for selective HER2 dephosphorylation, a previously uncharacterized mechanism for HER2 degradation and a novel function for the PTPN18 PEST domain. The new regulatory role of the PEST domain in the ubiquitination pathway will broaden our understanding of the functions of other important PEST domain-containing phosphatases, such as LYP and PTPN12. PMID:25081058

  3. Protein tyrosine phosphatase SHP-1 sensitizes EGFR/HER-2 positive breast cancer cells to trastuzumab through modulating phosphorylation of EGFR and HER-2

    PubMed Central

    Wu, Yifen; Li, Rong; Zhang, Junyi; Wang, Gang; Liu, Bin; Huang, Xiaofang; Zhang, Tao; Luo, Rongcheng

    2015-01-01

    Background Trastuzumab resistance in HER-2 positive breast cancer cells is closely related to overexpression of both epidermal growth factor receptor (EGFR) and human epidermal receptor (HER-2). SHP-1 has been demonstrated to downregulate tyrosine kinase activity including EGFR via its phosphatase function, but its effect on HER-2 activity is still unknown. Here, we examined the hypothesis that SHP-1 enhances the anticancer efficacy of trastuzumab in EGFR/HER-2 positive breast cancer cells through combining dual inhibition of EGFR and HER-2. Methods Trastuzumab-resistant breast cancer SKBr-3 cells were generated by long-term in vitro culture of SKBr-3cells in the presence of trastuzumab. The SHP-1 was ectopically expressed by stable transfection. The activity and expression of EGFR, HER-2, and downstream signaling pathways were tested by Western blot. Cell viability was examined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and apoptosis was examined by flow cytometry. The binding between SHP-1 and EGFR/HER-2 was evaluated by immunoprecipitation assay and bimolecular fluorescence complementation. The effects of SHP-1 on tumorigenicity and trastuzumab sensitivity were confirmed via in vivo xenograft model. Results Trastuzumab-resistant SKBr-3 cells showed aberrant co-expression of EGFR and HER-2. Introduction of wild-type SHP-1 inhibited cell proliferation, clone formation, and promoted the apoptosis induced by trastuzumab. Meanwhile, SHP-1 overexpression reduced phosphorylation levels of EGFR and HER-2 both in parental and trastuzumab-resistant SKBr-3 cells. In vivo study showed an increased antitumor effect of trastuzumab in SHP-1 overexpressed xenografts. At last, we discovered that SHP-1 can make complexes with both EGFR and HER-2, and both phospho-EGFR and phosphor-HER-2 levels in wild-type SHP-1 immunoprecipitates were less than those in phosphatase-inactive SHP-1 (C453S) immunoprecipitates, indicating that EGFR and HER-2 are

  4. Selective inhibition of tumor growth by clonal NK cells expressing an ErbB2/HER2-specific chimeric antigen receptor.

    PubMed

    Schönfeld, Kurt; Sahm, Christiane; Zhang, Congcong; Naundorf, Sonja; Brendel, Christian; Odendahl, Marcus; Nowakowska, Paulina; Bönig, Halvard; Köhl, Ulrike; Kloess, Stephan; Köhler, Sylvia; Holtgreve-Grez, Heidi; Jauch, Anna; Schmidt, Manfred; Schubert, Ralf; Kühlcke, Klaus; Seifried, Erhard; Klingemann, Hans G; Rieger, Michael A; Tonn, Torsten; Grez, Manuel; Wels, Winfried S

    2015-02-01

    Natural killer (NK) cells are an important effector cell type for adoptive cancer immunotherapy. Similar to T cells, NK cells can be modified to express chimeric antigen receptors (CARs) to enhance antitumor activity, but experience with CAR-engineered NK cells and their clinical development is still limited. Here, we redirected continuously expanding and clinically usable established human NK-92 cells to the tumor-associated ErbB2 (HER2) antigen. Following GMP-compliant procedures, we generated a stable clonal cell line expressing a humanized CAR based on ErbB2-specific antibody FRP5 harboring CD28 and CD3ζ signaling domains (CAR 5.28.z). These NK-92/5.28.z cells efficiently lysed ErbB2-expressing tumor cells in vitro and exhibited serial target cell killing. Specific recognition of tumor cells and antitumor activity were retained in vivo, resulting in selective enrichment of NK-92/5.28.z cells in orthotopic breast carcinoma xenografts, and reduction of pulmonary metastasis in a renal cell carcinoma model, respectively. γ-irradiation as a potential safety measure for clinical application prevented NK cell replication, while antitumor activity was preserved. Our data demonstrate that it is feasible to engineer CAR-expressing NK cells as a clonal, molecularly and functionally well-defined and continuously expandable cell therapeutic agent, and suggest NK-92/5.28.z cells as a promising candidate for use in adoptive cancer immunotherapy. PMID:25373520

  5. Selective Inhibition of Tumor Growth by Clonal NK Cells Expressing an ErbB2/HER2-Specific Chimeric Antigen Receptor

    PubMed Central

    Schönfeld, Kurt; Sahm, Christiane; Zhang, Congcong; Naundorf, Sonja; Brendel, Christian; Odendahl, Marcus; Nowakowska, Paulina; Bönig, Halvard; Köhl, Ulrike; Kloess, Stephan; Köhler, Sylvia; Holtgreve-Grez, Heidi; Jauch, Anna; Schmidt, Manfred; Schubert, Ralf; Kühlcke, Klaus; Seifried, Erhard; Klingemann, Hans G; Rieger, Michael A; Tonn, Torsten; Grez, Manuel; Wels, Winfried S

    2015-01-01

    Natural killer (NK) cells are an important effector cell type for adoptive cancer immunotherapy. Similar to T cells, NK cells can be modified to express chimeric antigen receptors (CARs) to enhance antitumor activity, but experience with CAR-engineered NK cells and their clinical development is still limited. Here, we redirected continuously expanding and clinically usable established human NK-92 cells to the tumor-associated ErbB2 (HER2) antigen. Following GMP-compliant procedures, we generated a stable clonal cell line expressing a humanized CAR based on ErbB2-specific antibody FRP5 harboring CD28 and CD3ζ signaling domains (CAR 5.28.z). These NK-92/5.28.z cells efficiently lysed ErbB2-expressing tumor cells in vitro and exhibited serial target cell killing. Specific recognition of tumor cells and antitumor activity were retained in vivo, resulting in selective enrichment of NK-92/5.28.z cells in orthotopic breast carcinoma xenografts, and reduction of pulmonary metastasis in a renal cell carcinoma model, respectively. γ-irradiation as a potential safety measure for clinical application prevented NK cell replication, while antitumor activity was preserved. Our data demonstrate that it is feasible to engineer CAR-expressing NK cells as a clonal, molecularly and functionally well-defined and continuously expandable cell therapeutic agent, and suggest NK-92/5.28.z cells as a promising candidate for use in adoptive cancer immunotherapy. PMID:25373520

  6. Targeting HER2

    PubMed Central

    Wong, Karen J; Baidoo, Kwamena E; Nayak, Tapan K; Regino, Celeste AS; Garmestani, Kayhan; Brechbiel, Martin W

    2010-01-01

    The potential of the HER2-targeting antibody trastuzumab as a radioimmunoconjugate useful for both imaging and therapy was investigated. Conjugation of trastuzumab with the acyclic bifunctional chelator CHX-A″-DTPA yielded a chelate:protein ratio of 3.4 ± 0.3; the immunoreactivity of the antibody unaffected. Radiolabeling was efficient, routinely yielding a product with high specific activity. Tumor targeting was evaluated in mice bearing subcutaneous (s.c.) xenografts of colorectal, pancreatic, ovarian and prostate carcinomas. High uptake of the radioimmunoconjugate, injected intravenously (i.v.), was observed in each of the models and the highest tumor %ID/g (51.18 ± 13.58) was obtained with the ovarian (SKOV-3) tumor xenograft. Specificity was demonstrated by the absence of uptake of 111In-trastuzumab by melanoma (A375) s.c. xenografts and 111In-HuIgG by s.c. LS-174T xenografts. Minimal uptake of i.v. injected 111In-trastuzumab in normal organs was confirmed in non-tumor-bearing mice. The in vivo behavior of 111In-trastuzumab in mice bearing intraperitoneal (i.p.) LS-174T tumors resulted in a tumor %ID/g of 130.85 ± 273.34 at 24 h. Visualization of tumor, s.c. and i.p. xenografts was achieved by γ-scintigraphy and PET imaging. Blood pool was evident as expected but cleared over time. The blood pharmacokinetics of i.v. and i.p. injected 111In-trastuzumab was determined in mice with and without tumors. The data from these in vitro and in vivo studies supported advancement of radiolabeled trastuzumab into two clinical studies, a Phase 0 imaging study in the Molecular Imaging Program of the National Cancer Institute and a Phase 1 radioimmunotherapy study at the University of Alabama. PMID:20716957

  7. Targeting, bio distributive and tumor growth inhibiting characterization of anti-HER2 affibody coupling to liposomal doxorubicin using BALB/c mice bearing TUBO tumors.

    PubMed

    Akhtari, Javad; Rezayat, Seyed Mahdi; Teymouri, Manouchehr; Alavizadeh, Seyedeh Hoda; Gheybi, Fatemeh; Badiee, Ali; Jaafari, Mahmoud Reza

    2016-05-30

    Human epidermal growth factor receptor 2 (HER2) is overexpressed in 20-30% of breast cancer tumors. In the current investigation, we exploited such a feature and utilized an anti-HER2 affibody (ZHER2:477) in combination with a pegylated liposomal doxorubicin (PLD) for concurrent passive and active targeting of HER2 overexpressing TUBO tumor, using BALB/c mice. It was determined that the affibody coupled liposomes (affisomes) was capable of increasing doxorubicin (Dox) delivery to HER2+ cells (SK-BR-3 and TUBO cells), while transferring drug similarly as low as naïve PLD to HER2- MDA-MB-231 cells. This also resulted in selectively enhance cytotoxicity. The veracity of targeting was further assessed utilizing DiD lipophilic tracer model liposomes via competition assay. An approximated 10 ligand/liposome integration caused Dox delivery at 50% of maximal delivery capacity (Kd). Such integration did not alter Dox release in vitro, while it affected the serum clearance profile. Affibody integration to PLD increased drug concentration in tumor and led to significantly further augmentation of drug in liver and spleen compared to those of PLD. Overall, such differences led to prolonging the mice life spans as compared to PLD. PMID:27039149

  8. Co-Targeting of JNK and HUNK in Resistant HER2-Positive Breast Cancer

    PubMed Central

    Phelps-Polirer, Kendall; Abt, Melissa A.; Smith, Danzell; Yeh, Elizabeth S.

    2016-01-01

    Strategies for successful primary treatment of HER2-positive breast cancer include use of the HER2 inhibitors trastuzumab or lapatinib in combination with standard chemotherapy. While successful, many patients develop resistance to these HER2 inhibitors indicating an unmet need. Consequently, current research efforts are geared toward understanding mechanisms of resistance and the signaling modalities that regulate these mechanisms. We have undertaken a study to examine whether signaling molecules downstream of epidermal growth factor receptor, which often act as compensatory signaling outlets to circumvent HER2 inhibition, can be co-targeted to overcome resistance. We identified JNK signaling as a potential area of intervention and now show that inhibiting JNK using the pan-JNK inhibitor, SP600125, is effective in the HER2-positive, resistant JIMT-1 xenograft mammary tumor model. We also investigate potential combination strategies to bolster the effects of JNK inhibition and find that co-targeting of JNK and the protein kinase HUNK can prohibit tumor growth of resistant HER2-positive mammary tumors in vivo. PMID:27045589

  9. Decoupling of the PI3K pathway via mutation necessitates combinatorial treatment in HER2+ breast cancer

    DOE PAGESBeta

    Korkola, James E.; Collisson, Eric A.; Heiser, Laura; Oates, Chris; Bayani, Nora; Itani, Sleiman; Esch, Amanda; Thompson, Wallace; Griffith, Obi L.; Wang, Nicholas J.; et al

    2015-07-16

    We report here on experimental and theoretical efforts to determine how best to combine drugs that inhibit HER2 and AKT in HER2+ breast cancers. We accomplished this by measuring cellular and molecular responses to lapatinib and the AKT inhibitors (AKTi) GSK690693 and GSK2141795 in a panel of 22 HER2+ breast cancer cell lines carrying wild type or mutant PIK3CA. We observed that combinations of lapatinib plus AKTi were synergistic in HER2/PIK3CAmut cell lines but not in HER2+/PIK3CAwt cell lines. We measured changes in phospho-protein levels in 15 cell lines after treatment with lapatinib, AKTi or lapatinib + AKTi to shedmore » light on the underlying signaling dynamics. This revealed that p-S6RP levels were less well attenuated by lapatinib in HER2+/PIK3CAmut cells compared to HER2+/PIK3CAwt cells and that lapatinib + AKTi reduced p-S6RP levels to those achieved in HER2+/PIK3CAwt cells with lapatinib alone. We also found that that compensatory up-regulation of p-HER3 and p-HER2 is blunted in PIK3CAmut cells following lapatinib + AKTi treatment. Responses of HER2+ SKBR3 cells transfected with lentiviruses carrying control or PIK3CAmut sequences were similar to those observed in HER2+/PIK3CAmut cell lines but not in HER2+/PIK3CAwt cell lines. We used a nonlinear ordinary differential equation model to support the idea that PIK3CA mutations act as downstream activators of AKT that blunt lapatinib inhibition of downstream AKT signaling and that the effects of PIK3CA mutations can be countered by combining lapatinib with an AKTi. This combination does not confer substantial benefit beyond lapatinib in HER2+/PIK3CAwt cells.« less

  10. Pertuzumab: a review of its use for first-line combination treatment of HER2-positive metastatic breast cancer.

    PubMed

    McCormack, Paul L

    2013-09-01

    Pertuzumab (Perjeta®) is a humanized anti-HER2 monoclonal antibody that binds to the extracellular dimerization subdomain of the HER2 receptor and reduces HER2 intracellular signalling by preventing HER2 from forming heterodimers with other HER receptors. Inhibition of HER2 signalling results in a reduction of tumour cell proliferation, invasiveness and survival. Pertuzumab and trastuzumab bind to different sites on the HER2 receptor and have complementary antitumour activities; they act synergistically in inhibiting the growth of HER2-overexpressing breast cancer cell lines in vitro. The efficacy of intravenous pertuzumab (840 mg loading dose, then 420 mg every 3 weeks) in combination with trastuzumab plus docetaxel in the first-line treatment of HER2-positive metastatic breast cancer was demonstrated in the randomized, double-blind, placebo-controlled, multinational, phase III CLEOPATRA trial. Pertuzumab in combination with trastuzumab and docetaxel significantly increased independently assessed median progression-free survival (primary endpoint), objective response rate and overall survival compared with placebo in combination with trastuzumab and docetaxel. Pertuzumab had an acceptable tolerability profile when added to trastuzumab and docetaxel in the pivotal CLEOPATRA trial. Thus, pertuzumab is a valuable addition to the growing list of anti-HER2 targeted therapies for breast cancer. PMID:23982598

  11. Expression and purification of HER2 extracellular domain proteins in Schneider2 insect cells.

    PubMed

    Kanthala, Shanthi; Mill, Christopher P; Riese, David J; Jaiswal, Mihir; Jois, Seetharama

    2016-09-01

    Overexpression of human epidermal growth factor receptor 2 (HER2/ErbB2/Neu) results in ligand independent activation of kinase signaling and is found in about 30% of human breast cancers, and is correlated with a more aggressive tumor phenotype. The HER2 extracellular domain (ECD) consists of four domains - I, II, III and IV. Although the role of each domain in the dimerization and activation of the receptor has been extensively studied, the role of domain IV (DIV) is not clearly understood yet. In our previous studies, we reported peptidomimetic molecules inhibit HER2:HER3 heterodimerization. In order to study the binding interactions of peptidomimetics with HER2 DIV in detail, properly folded recombinant HER2 protein in pure form is important. We have expressed and purified HER2 ECD and DIV proteins in the Drosophila melanogaster Schneider2 (S2) cell line. Using the commercial Drosophila expression system (DES), we transfected S2 cells with plasmids designed to direct the expression of secreted recombinant HER2 ECD and DIV proteins. The secreted proteins were purified from the conditioned medium by filtration, ultrafiltration, dialysis and nickel affinity chromatography techniques. The purified HER2 proteins were then analyzed using Western blot, mass spectrometry and circular dichroism (CD) spectroscopy. PMID:26363121

  12. Lapatinib in Combination With Radiation Diminishes Tumor Regrowth in HER2+ and Basal-Like/EGFR+ Breast Tumor Xenografts

    SciTech Connect

    Sambade, Maria J.; Kimple, Randall J.; Camp, J. Terese; Peters, Eldon; Livasy, Chad A.; Sartor, Carolyn I.; Shields, Janiel M.

    2010-06-01

    Purpose: To determine whether lapatinib, a dual epidermal growth factor receptor (EGFR)/HER2 kinase inhibitor, can radiosensitize EGFR+ or HER2+ breast cancer xenografts. Methods and Materials: Mice bearing xenografts of basal-like/EGFR+ SUM149 and HER2+ SUM225 breast cancer cells were treated with lapatinib and fractionated radiotherapy and tumor growth inhibition correlated with alterations in ERK1 and AKT activation by immunohistochemistry. Results: Basal-like/EGFR+ SUM149 breast cancer tumors were completely resistant to treatment with lapatinib alone but highly growth impaired with lapatinib plus radiotherapy, exhibiting an enhancement ratio average of 2.75 and a fractional tumor product ratio average of 2.20 during the study period. In contrast, HER2+ SUM225 breast cancer tumors were highly responsive to treatment with lapatinib alone and yielded a relatively lower enhancement ratio average of 1.25 during the study period with lapatinib plus radiotherapy. Durable tumor control in the HER2+ SUM225 model was more effective with the combination treatment than either lapatinib or radiotherapy alone. Immunohistochemical analyses demonstrated that radiosensitization by lapatinib correlated with ERK1/2 inhibition in the EGFR+ SUM149 model and with AKT inhibition in the HER2+ SUM225 model. Conclusion: Our data suggest that lapatinib combined with fractionated radiotherapy may be useful against EGFR+ and HER2+ breast cancers and that inhibition of downstream signaling to ERK1/2 and AKT correlates with sensitization in EGFR+ and HER2+ cells, respectively.

  13. Lapatinib in Combination with Radiation Diminishes Tumor Regrowth in HER2+ and Basal-Like/EGFR+ Breast Tumor Xenografts

    PubMed Central

    Sambade, Maria J.; Kimple, Randall J.; Camp, J. Terese; Peters, Eldon; Livasy, Chad A.; Sartor, Carolyn I.; Shields, Janiel M.

    2010-01-01

    Purpose To determine whether lapatinib, a dual epidermal growth factor receptor (EGFR)/HER2 kinase inhibitor, can radiosensitize EGFR+ or HER2+ breast cancer xenografts. Methods and Materials Mice bearing xenografts of basal-like/EGFR+ SUM149 and HER2+ SUM225 breast cancer cells were treated with lapatinib and fractionated radiotherapy and tumor growth inhibition correlated with alterations in ERK1 and AKT activation by immunohistochemistry. Results Basal-like/EGFR+ SUM149 breast cancer tumors were completely resistant to treatment with lapatinib alone but highly growth impaired with lapatinib plus radiotherapy, exhibiting an enhancement ratio average of 2.75 and a fractional tumor product ratio average of 2.20 during the study period. In contrast, HER2+ SUM225 breast cancer tumors were highly responsive to treatment with lapatinib alone and yielded a relatively lower enhancement ratio average of 1.25 during the study period with lapatinib plus radiotherapy. Durable tumor control in the HER2+ SUM225 model was more effective with the combination treatment than either lapatinib or radiotherapy alone. Immunohistochemical analyses demonstrated that radiosensitization by lapatinib correlated with ERK1/2 inhibition in the EGFR+ SUM149 model and with AKT inhibition in the HER2+ SUM225 model. Conclusion Our data suggest that lapatinib combined with fractionated radiotherapy may be useful against EGFR+ and HER2+ breast cancers and that inhibition of downstream signaling to ERK1/2 and AKT correlates with sensitization in EGFR+ and HER2+ cells, respectively. PMID:20457354

  14. Design, synthesis and characterization of peptidomimetic conjugate of BODIPY targeting HER2 protein extracellular domain

    PubMed Central

    Banappagari, Sashikanth; McCall, Alecia; Fontenot, Krystal; Vicente, M. Graca H.; Gujar, Amit; Satyanarayanajois, Seetharama

    2013-01-01

    Among the EGFRs, HER2 is a major heterodimer partner and also has important implications in the formation of particular tumors. Interaction of HER2 protein with other EGFR proteins can be modulated by small molecule ligands and, hence, these protein-protein interactions play a key role in biochemical reactions related to control of cell growth. A peptidomimetic (compound 5-1) that binds to HER2 protein extracellular domain and inhibits protein-protein interactions of EGFRs was conjugated with BODIPY (4,4-difluoro-5,7-dimethyl-4-bora-3a,4a-diaza-s-indacene). Conjugation of BODIPY to the peptidomimetic was investigated by different approaches. The conjugate was characterized for its ability to bind to HER2 overexpressing SKBR-3 and BT-474 cells. Furthermore, cellular uptake of conjugate of BODIPY was studied in the presence of membrane tracker and Lyso tracker using confocal microscopy. Our results suggested that fluorescently labeled compound 5-7 binds to the extracellular domain and stays in the membrane for nearly 24 h. After 24 h there is an indication of internalization of the conjugate. Inhibition of protein-protein interaction and downstream signaling effect of compound 5-1 was also studied by proximity ligation assay and western blot analysis. Results suggested that compound 5-1 inhibits protein-protein interactions of HER2-HER3 and phosphorylation of HER2 in a time-dependent manner. PMID:23688700

  15. Afatinib demonstrates remarkable activity against HER2-amplified uterine serous endometrial cancer in vitro and in vivo

    PubMed Central

    Schwab, C L; Bellone, S; English, D P; Roque, D M; Lopez, S; Cocco, E; Nicoletti, R; Bortolomai, I; Bonazzoli, E; Ratner, E; Silasi, D-A; Azodi, M; Schwartz, P E; Rutherford, T J; Santin, A D

    2014-01-01

    Background: Uterine serous carcinomas (USCs) are an aggressive form of uterine cancer that may rely on HER2/neu amplification as a driver of proliferation. The objective of this paper is to assess the sensitivity of USC cell lines with and without HER2/neu gene amplification to afatinib, an irreversible ErbB tyrosine kinase inhibitor, and to test the efficacy of afatinib in the treatment of HER2-amplified USC xenografts. Methods: Eight of fifteen primary USC cell lines (four with HER2 amplification and four without) demonstrating similar in vitro growth rates were treated with scalar concentrations of afatinib. Effects on cell growth, signalling and cell cycle distribution were determined by flow cytometry assays. Mice harbouring xenografts of HER2/neu-amplified USC were treated with afatinib by gavage to determine the effect on tumour growth and overall survival. Results: Primary chemotherapy-resistant USC cell lines harbouring HER2/neu gene amplification were exquisitely sensitive to afatinib exposure (mean±s.e.m. IC50=0.0056±0.0006 μM) and significantly more sensitive than HER2/neu-non-amplified USC cell lines (mean±s.e.m. IC50=0.563±0.092 μM, P<0.0001). Afatinib exposure resulted in abrogation of cell survival, inhibition of HER2/neu autophosphorylation and S6 transcription factor phosphorylation in HER2/neu overexpressing USC and inhibited the growth of HER2-amplified tumour xenografts improving overall survival (P=0.0017). Conclusions: Afatinib may be highly effective against HER2/neu-amplified chemotherapy-resistant USC. The investigation of afatinib in patients harbouring HER2/neu-amplified USC is warranted. PMID:25268372

  16. Discovery of a Potential HER2 Inhibitor from Natural Products for the Treatment of HER2-Positive Breast Cancer

    PubMed Central

    Li, Jianzong; Wang, Haiyang; Li, Junjie; Bao, Jinku; Wu, Chuanfang

    2016-01-01

    Breast cancer is one of the most lethal types of cancer in women worldwide due to the late stage detection and resistance to traditional chemotherapy. The human epidermal growth factor receptor 2 (HER2) is considered as a validated target in breast cancer therapy. Even though a substantial effort has been made to develop HER2 inhibitors, only lapatinib has been approved by the U.S. Food and Drug Administration (FDA). Side effects were observed in a majority of the patients within one year of treatment initiation. Here, we took advantage of bioinformatics tools to identify novel effective HER2 inhibitors. The structure-based virtual screening combined with ADMET (absorption, distribution, metabolism, excretion and toxicity) prediction was explored. In total, 11,247 natural compounds were screened. The top hits were evaluated by an in vitro HER2 kinase inhibition assay. The cell proliferation inhibition effect of identified inhibitors was evaluated in HER2-overexpressing SKBR3 and BT474 cell lines. We found that ZINC15122021 showed favorable ADMET properties and attained high binding affinity against HER2. Moreover, ZINC15122021 showed high kinase inhibition activity against HER2 and presented outstanding cell proliferation inhibition activity against both SKBR3 and BT474 cell lines. Results reveal that ZINC15122021 can be a potential HER2 inhibitor. PMID:27376283

  17. Discovery of a Potential HER2 Inhibitor from Natural Products for the Treatment of HER2-Positive Breast Cancer.

    PubMed

    Li, Jianzong; Wang, Haiyang; Li, Junjie; Bao, Jinku; Wu, Chuanfang

    2016-01-01

    Breast cancer is one of the most lethal types of cancer in women worldwide due to the late stage detection and resistance to traditional chemotherapy. The human epidermal growth factor receptor 2 (HER2) is considered as a validated target in breast cancer therapy. Even though a substantial effort has been made to develop HER2 inhibitors, only lapatinib has been approved by the U.S. Food and Drug Administration (FDA). Side effects were observed in a majority of the patients within one year of treatment initiation. Here, we took advantage of bioinformatics tools to identify novel effective HER2 inhibitors. The structure-based virtual screening combined with ADMET (absorption, distribution, metabolism, excretion and toxicity) prediction was explored. In total, 11,247 natural compounds were screened. The top hits were evaluated by an in vitro HER2 kinase inhibition assay. The cell proliferation inhibition effect of identified inhibitors was evaluated in HER2-overexpressing SKBR3 and BT474 cell lines. We found that ZINC15122021 showed favorable ADMET properties and attained high binding affinity against HER2. Moreover, ZINC15122021 showed high kinase inhibition activity against HER2 and presented outstanding cell proliferation inhibition activity against both SKBR3 and BT474 cell lines. Results reveal that ZINC15122021 can be a potential HER2 inhibitor. PMID:27376283

  18. MicroRNA and HER2-overexpressing Cancer

    PubMed Central

    Wang, Shizhen Emily; Lin, Ren-Jang

    2013-01-01

    The discovery of microRNAs (miRNAs) has opened up new avenues for studying cancer at the molecular level, featuring a post-genomic era of biomedical research. These non-coding regulatory RNA molecules of ~22 nucleotides have emerged as important cancer biomarkers, effectors, and targets. In this review, we focus on the dysregulated biogenesis and function of miRNAs in cancers with an overexpression of the proto-oncogene HER2. Many of the studies reviewed here were carried out in breast cancer, where HER2 overexpression has been extensively studied and HER2-targeted therapy practiced for more than a decade. MiRNA signatures that can be used to classify tumors with different HER2 status have been reported but little consensus can be established among various studies, emphasizing the needs for additional well-controlled profiling approaches and meta-analyses in large and well-balanced patient cohorts. We further discuss three aspects of microRNA dysregulation in or contribution to HER2-associated malignancies or therapies: (a) miRNAs that are up- or down-regulated by HER2 and mediate the downstream signaling of HER2; (b) miRNAs that suppress the expression of HER2 or a factor in HER2 receptor complexes, such as HER3; and (c) miRNAs that affect responses to anti-HER2 therapies. The regulatory mechanisms are elaborated using mainly examples of miR-205, miR-125, and miR-21. Understanding the regulation and function of miRNAs in HER2-overexpressing tumors shall shed new light on the pathogenic mechanisms of microRNAs and the HER2 proto-oncogene in cancer, as well as on individualized or combinatorial anti-HER2 therapies. PMID:25070783

  19. Downregulation of GLUT4 contributes to effective intervention of estrogen receptor-negative/HER2-overexpressing early stage breast disease progression by lapatinib.

    PubMed

    Acharya, Sunil; Xu, Jia; Wang, Xiao; Jain, Shalini; Wang, Hai; Zhang, Qingling; Chang, Chia-Chi; Bower, Joseph; Arun, Banu; Seewaldt, Victoria; Yu, Dihua

    2016-01-01

    Tamoxifen and aromatase inhibitors (AIs) have shown efficacy in prevention of estrogen receptor-positive (ER+) breast cancer; however, there exists no proven prevention strategy for estrogen receptor-negative (ER-) breast cancer. Up to 40% of ER- breast cancers have human epidermal growth factor receptor 2 overexpression (HER2+), suggesting HER2 signaling might be a good target for chemoprevention for certain ER- breast cancers. Here, we tested the feasibility of the HER2-targeting agent lapatinib in prevention and/or early intervention of an ER-/HER2+ early-stage breast disease model. We found that lapatinib treatment forestalled the progression of atypical ductal hyperplasia (ADH)-like acini to ductal carcinoma in situ (DCIS)-like acini in ER-/HER2+ human mammary epithelial cells (HMECs) in 3D culture. Mechanistically, we found that inhibition of HER2/Akt signaling by lapatinib led to downregulation of GLUT4 and a reduced glucose uptake in HER2-overexpressing cells, resulting in decreased proliferation and increased apoptosis of these cells in 3D culture. Additionally, our data suggest that HER2-driven glycolytic metabolic dysregulation in ER-/HER2+ HMECs might promote early-stage breast disease progression, which can be reversed by lapatinib treatment. Furthermore, low-dose lapatinib treatment, starting at the early stages of mammary grand transformation in the MMTV-neu* mouse model, significantly delayed mammary tumor initiation and progression, extended tumor-free survival, which corresponded to effective inhibition of HER2/Akt signaling and downregulation of GLUT4 in vivo. Taken together, our results indicate that lapatinib, through its inhibition of key signaling pathways and tumor-promoting metabolic events, is a promising agent for the prevention/early intervention of ER-/HER2+ breast cancer progression. PMID:27293993

  20. Downregulation of GLUT4 contributes to effective intervention of estrogen receptor-negative/HER2-overexpressing early stage breast disease progression by lapatinib

    PubMed Central

    Acharya, Sunil; Xu, Jia; Wang, Xiao; Jain, Shalini; Wang, Hai; Zhang, Qingling; Chang, Chia-Chi; Bower, Joseph; Arun, Banu; Seewaldt, Victoria; Yu, Dihua

    2016-01-01

    Tamoxifen and aromatase inhibitors (AIs) have shown efficacy in prevention of estrogen receptor-positive (ER+) breast cancer; however, there exists no proven prevention strategy for estrogen receptor-negative (ER-) breast cancer. Up to 40% of ER- breast cancers have human epidermal growth factor receptor 2 overexpression (HER2+), suggesting HER2 signaling might be a good target for chemoprevention for certain ER- breast cancers. Here, we tested the feasibility of the HER2-targeting agent lapatinib in prevention and/or early intervention of an ER-/HER2+ early-stage breast disease model. We found that lapatinib treatment forestalled the progression of atypical ductal hyperplasia (ADH)-like acini to ductal carcinoma in situ (DCIS)-like acini in ER-/HER2+ human mammary epithelial cells (HMECs) in 3D culture. Mechanistically, we found that inhibition of HER2/Akt signaling by lapatinib led to downregulation of GLUT4 and a reduced glucose uptake in HER2-overexpressing cells, resulting in decreased proliferation and increased apoptosis of these cells in 3D culture. Additionally, our data suggest that HER2-driven glycolytic metabolic dysregulation in ER-/HER2+ HMECs might promote early-stage breast disease progression, which can be reversed by lapatinib treatment. Furthermore, low-dose lapatinib treatment, starting at the early stages of mammary grand transformation in the MMTV-neu* mouse model, significantly delayed mammary tumor initiation and progression, extended tumor-free survival, which corresponded to effective inhibition of HER2/Akt signaling and downregulation of GLUT4 in vivo. Taken together, our results indicate that lapatinib, through its inhibition of key signaling pathways and tumor-promoting metabolic events, is a promising agent for the prevention/early intervention of ER-/HER2+ breast cancer progression. PMID:27293993

  1. HER2-targeted liposomal doxorubicin displays enhanced anti-tumorigenic effects without associated cardiotoxicity

    SciTech Connect

    Reynolds, Joseph G.; Geretti, Elena; Hendriks, Bart S.; Lee, Helen; Leonard, Shannon C.; Klinz, Stephan G.; Noble, Charles O.; Lücker, Petra B.; Zandstra, Peter W.; Drummond, Daryl C.; Olivier, Kenneth J.; Nielsen, Ulrik B.; Niyikiza, Clet; Agresta, Samuel V.; Wickham, Thomas J.

    2012-07-01

    Anthracycline-based regimens are a mainstay of early breast cancer therapy, however their use is limited by cardiac toxicity. The potential for cardiotoxicity is a major consideration in the design and development of combinatorial therapies incorporating anthracyclines and agents that target the HER2-mediated signaling pathway, such as trastuzumab. In this regard, HER2-targeted liposomal doxorubicin was developed to provide clinical benefit by both reducing the cardiotoxicity observed with anthracyclines and enhancing the therapeutic potential of HER2-based therapies that are currently available for HER2-overexpressing cancers. While documenting the enhanced therapeutic potential of HER2-targeted liposomal doxorubicin can be done with existing models, there has been no validated human cardiac cell-based assay system to rigorously assess the cardiotoxicity of anthracyclines. To understand if HER2-targeting of liposomal doxorubicin is possible with a favorable cardiac safety profile, we applied a human stem cell-derived cardiomyocyte platform to evaluate the doxorubicin exposure of human cardiac cells to HER2-targeted liposomal doxorubicin. To the best of our knowledge, this is the first known application of a stem cell-derived system for evaluating preclinical cardiotoxicity of an investigational agent. We demonstrate that HER2-targeted liposomal doxorubicin has little or no uptake into human cardiomyocytes, does not inhibit HER2-mediated signaling, results in little or no evidence of cardiomyocyte cell death or dysfunction, and retains the low penetration into heart tissue of liposomal doxorubicin. Taken together, this data ultimately led to the clinical decision to advance this drug to Phase I clinical testing, which is now ongoing as a single agent in HER2-expressing cancers. -- Highlights: ► Novel approach using stem cell-derived cardiomyocytes to assess preclinical safety. ► HER2-targeted liposomal doxorubicin has improved safety profile vs free doxorubicin

  2. A bispecific HER2-targeting FynomAb with superior antitumor activity and novel mode of action.

    PubMed

    Brack, Simon; Attinger-Toller, Isabella; Schade, Babette; Mourlane, Frédéric; Klupsch, Kristina; Woods, Richard; Hachemi, Helen; von der Bey, Ulrike; Koenig-Friedrich, Susann; Bertschinger, Julian; Grabulovski, Dragan

    2014-08-01

    Upregulation of HER2 is a hallmark of 20% to 30% of invasive breast cancers, rendering this receptor an attractive target for cancer therapy. Although HER2-targeting agents have provided substantial clinical benefit as cancer therapeutics, there is a need for the development of new agents aiming at circumventing anti-HER2 resistance. On the basis of the approved antibody pertuzumab, we have created a panel of bispecific FynomAbs, which target two epitopes on HER2. FynomAbs are fusion proteins of an antibody and a Fyn SH3-derived binding protein. One bispecific FynomAb, COVA208, was characterized in detail and showed a remarkable ability to induce rapid HER2 internalization and apoptosis in vitro. Moreover, it elicited a strong inhibition of downstream HER2 signaling by reducing HER2, HER3, and EGFR levels in vitro and in vivo. Importantly, COVA208 demonstrated superior activity in four different xenograft models as compared with the approved antibodies trastuzumab and pertuzumab. The bispecific FynomAb COVA208 has the potential to enhance the clinical efficacy and expand the scope of HER2-directed therapies, and delineates a paradigm for designing a new class of antibody-based therapeutics for other receptor targets. PMID:24994770

  3. Quantitative assays for the measurement of HER1-HER2 heterodimerization and phosphorylation in cell lines and breast tumors: applications for diagnostics and targeted drug mechanism of action

    PubMed Central

    2011-01-01

    Introduction Ligand-bound and phosphorylated ErbB/HER heterodimers are potent signaling forms of this receptor family, and quantitative measurements of these active receptors may be predictive of patient response to targeted therapies. Using VeraTag™ technology, we developed and characterized quantitative assays measuring epidermal growth factor (EGF)-dependent increases in activated HER receptors in tumor cell line lysates and formalin-fixed, paraffin-embedded (FFPE) tumor sections. We demonstrated the ability of the assays to quantitatively measure changes in activated HER1 and HER2 receptor levels in cell lines following treatment with 2C4, erlotinib, and lapatinib. We utilized these assays to determine the prevalence and distribution of activated HER1, HER2, and HER1-HER2 heterodimers in 43 HER2-positive breast tumors. Methods Assays for activated HER1 and HER2 receptors in FFPE and cell lysate formats were developed using VeraTag™ technology, which requires the proximity of an antibody pair for light-dependent release of a fluorescently labeled tag, followed by capillary electrophoresis-based quantitation. Results Ligand-dependent and independent HER1-HER2 heterodimer levels measured by lysate and FFPE VeraTag™ assays trended with HER1 and HER2 expression levels in tumor cell lines, which was confirmed by co-immunoprecipitation. The formation of EGF-dependent HER1-HER2 heterodimers were inhibited by the HER2-targeted monoclonal antibody 2C4 and stabilized by the HER1 tyrosine kinase inhibitor (TKI) erlotinib. EGF-dependent HER1 and HER2 phosphorylation was inhibited by lapatinib and erlotinib. Further, we observed that dominant receptor signaling patterns may switch between HER1-HER1 and HER1-HER2, depending on drug mechanism of action and relative levels of HER receptors. In FFPE breast tumors that expressed both HER1 and HER2, HER1-HER2 heterodimers were detected in 25 to 50% of tumors, depending on detection method. The levels of activated phospho

  4. Quantitative Analysis of HER2-mediated Effects on HER2 and Epidermal Growth Factor Receptor Endocytosis: DISTRIBUTION OF HOMO- AND HETERODIMERS DEPENDS ON RELATIVE HER2 LEVELS

    SciTech Connect

    Hendriks, Bart S.; Opresko, Lee ); Wiley, H Steven ); Lauffenburger, Douglas A.

    2003-05-15

    Endocytic trafficking plays an important role in the regulation of the epidermal growth factor receptor (EGFR) family. Many cell types express multiple EGFR family members (including EGFR, HER2, HER3 and/or HER4) that interact to form an array of homo- and hetero-dimers. Differential trafficking of these receptors should strongly affect signaling through this system by changing substrate access and heterodimerization efficiency. Because of the complexity of these dynamic processes we used a quantitative, computational model to understand this system. As a test case, parameters characterizing EGFR and HER2 interactions were derived using experimental data obtained from mammary epithelial cells constructed to express different levels of HER2. With this data we were able to estimate receptor-specific internalization rate constants and dimer uncoupling rate constants. These parameters were not otherwise experimentally accessible due to the complex system interplay. Our models indicated that HER2:EGFR heterodimers traffic as single entities. Direct experiments using EGF and anti-HER2 and anti-EGFR antibodies using independently derived cell lines confirmed many of the predictions of the model. Furthermore, our model could predict the relationship between HER2 expression levels and the transient distribution of EGFR homodimers and heterodimers. Our results suggest that the levels of HER2 found on normal cells are barely at the threshold necessary to drive efficient heterodimerization. Thus, altering local HER2 concentrations in membrane microdomains could serve as an effective mechanism for regulating HER2 heterodimerization and could explain why HER2 overexpression found in some cancers have such a profound effect on cell physiology.

  5. Neratinib overcomes trastuzumab resistance in HER2 amplified breast cancer.

    PubMed

    Canonici, Alexandra; Gijsen, Merel; Mullooly, Maeve; Bennett, Ruth; Bouguern, Noujoude; Pedersen, Kasper; O'Brien, Neil A; Roxanis, Ioannis; Li, Ji-Liang; Bridge, Esther; Finn, Richard; Siamon, Dennis; McGowan, Patricia; Duffy, Michael J; O'Donovan, Norma; Crown, John; Kong, Anthony

    2013-10-01

    Trastuzumab has been shown to improve the survival outcomes of HER2 positive breast cancer patients. However, a significant proportion of HER2-positive patients are either inherently resistant or develop resistance to trastuzumab. We assessed the effects of neratinib, an irreversible panHER inhibitor, in a panel of 36 breast cancer cell lines. We further assessed its effects with or without trastuzumab in several sensitive and resistant breast cancer cells as well as a BT474 xenograft model. We confirmed that neratinib was significantly more active in HER2-amplified than HER2 non-amplified cell lines. Neratinib decreased the activation of the 4 HER receptors and inhibited downstream pathways. However, HER3 and Akt were reactivated at 24 hours, which was prevented by the combination of trastuzumab and neratinib. Neratinib also decreased pHER2 and pHER3 in acquired trastuzumab resistant cells. Neratinib in combination with trastuzumab had a greater growth inhibitory effect than either drug alone in 4 HER2 positive cell lines. Furthermore, trastuzumab in combination with neratinib was growth inhibitory in SKBR3 and BT474 cells which had acquired resistance to trastuzumab as well as in a BT474 xenograft model. Innately trastuzumab resistant cell lines showed sensitivity to neratinib, but the combination did not enhance response compared to neratinib alone. Levels of HER2 and phospho-HER2 showed a direct correlation with sensitivity to neratinib. Our data indicate that neratinib is an effective anti-HER2 therapy and counteracted both innate and acquired trastuzumab resistance in HER2 positive breast cancer. Our results suggest that combined treatment with trastuzumab and neratinib is likely to be more effective than either treatment alone for both trastuzumab-sensitive breast cancer as well as HER2-positive tumors with acquired resistance to trastuzumab. PMID:24009064

  6. Neratinib overcomes trastuzumab resistance in HER2 amplified breast cancer

    PubMed Central

    Mullooly, Maeve; Bennett, Ruth; Bouguern, Noujoude; Pedersen, Kasper; O'Brien, Neil A; Roxanis, Ioannis; Li, Ji-Liang; Bridge, Esther; Finn, Richard; Slamon, Dennis; McGowan, Patricia; Duffy, Michael J.

    2013-01-01

    Trastuzumab has been shown to improve the survival outcomes of HER2 positive breast cancer patients. However, a significant proportion of HER2-positive patients are either inherently resistant or develop resistance to trastuzumab. We assessed the effects of neratinib, an irreversible panHER inhibitor, in a panel of 36 breast cancer cell lines. We further assessed its effects with or without trastuzumab in several sensitive and resistant breast cancer cells as well as a BT474 xenograft model. We confirmed that neratinib was significantly more active in HER2-amplified than HER2 non-amplified cell lines. Neratinib decreased the activation of the 4 HER receptors and inhibited downstream pathways. However, HER3 and Akt were reactivated at 24 hours, which was prevented by the combination of trastuzumab and neratinib. Neratinib also decreased pHER2 and pHER3 in acquired trastuzumab resistant cells. Neratinib in combination with trastuzumab had a greater growth inhibitory effect than either drug alone in 4 HER2 positive cell lines. Furthermore, trastuzumab in combination with neratinib was growth inhibitory in SKBR3 and BT474 cells which had acquired resistance to trastuzumab as well as in a BT474 xenograft model. Innately trastuzumab resistant cell lines showed sensitivity to neratinib, but the combination did not enhance response compared to neratinib alone. Levels of HER2 and phospho-HER2 showed a direct correlation with sensitivity to neratinib. Our data indicate that neratinib is an effective anti-HER2 therapy and counteracted both innate and acquired trastuzumab resistance in HER2 positive breast cancer. Our results suggest that combined treatment with trastuzumab and neratinib is likely to be more effective than either treatment alone for both trastuzumab-sensitive breast cancer as well as HER2-positive tumors with acquired resistance to trastuzumab. PMID:24009064

  7. First MNKs degrading agents block phosphorylation of eIF4E, induce apoptosis, inhibit cell growth, migration and invasion in triple negative and Her2-overexpressing breast cancer cell lines.

    PubMed

    Ramalingam, Senthilmurugan; Gediya, Lalji; Kwegyir-Afful, Andrew K; Ramamurthy, Vidya P; Purushottamachar, Puranik; Mbatia, Hannah; Njar, Vincent C O

    2014-01-30

    Some retinoic acid metabolism blocking agents (RAMBAs) are known to exhibit a wide range of anticancer activities by mechanisms that are still not completely resolved. This study investigated the anticancer efficacy and mechanism(s) of novel RAMBA retinamides (RRs) in triple negative and Her-2 overexpressing breast cancer cells. Specifically, we examined the possibility that RRs affect the translational machinery in these breast cancer (BC) cells. Recent findings suggest that overexpression of eukaryotic translation initiation factor 4E (eIF4E) in breast cancers critically augments CAP-dependent mRNA translation and synthesis of proteins involved in cell growth, cell proliferation, invasion and apoptosis evasion. The oncogenic potential of eIF4E is strictly dependent on serine209 phosphorylation by upstream MAPK-interacting kinases (Mnks). Targeting Mnk/eIF4E pathway for blocking Mnk function and eIF4E phosphorylation is therefore a novel approach for treating BCs, particularly for Her2-positive and triple negative breast cancers that have no indications for endocrine therapy or effective treatment regimes. We report for the first time that the degradation of Mnk1 by RRs in BC cells blocks eIF4E phosphorylation and subsequently inhibits cell growth, colonization, invasion, and migration and induce apoptosis. Most importantly, the anticancer efficacy of RRs was mediated via degrading Mnk rather than inhibiting its kinase activity like Mnk inhibitors (cercosporamide and CGP57380). Furthermore, RRs potencies on peIF4E down-regulation and growth inhibition were superior to those of two clinically relevant retinoids and the Mnk inhibitors. Together our findings provide the first preclinical proof-of-concept of novel Mnk degrading agents for Mnk/eIF4E based therapeutic treatment of breast cancers. PMID:24504069

  8. First Mnks degrading agents block phosphorylation of eIF4E, induce apoptosis, inhibit cell growth, migration and invasion in triple negative and Her2-overexpressing breast cancer cell lines

    PubMed Central

    Ramalingam, Senthilmurugan; Gediya, Lalji; Kwegyir-Afful, Andrew K.; Ramamurthy, Vidya P.; Purushottamachar, Puranik; Mbatia, Hannah; Njar, Vincent C. O.

    2014-01-01

    Some retinoic acid metabolism blocking agents (RAMBAs) are known to exhibit a wide range of anticancer activities by mechanisms that are still not completely resolved. This study investigated the anticancer efficacy and mechanism(s) of novel RAMBA retinamides (RRs) in triple negative and Her-2 overexpressing breast cancer cells. Specifically, we examined the possibility that RRs affect the translational machinery in these breast cancer (BC) cells. Recent findings suggest that overexpression of eukaryotic translation initiation factor 4E (eIF4E) in breast cancers critically augments CAP-dependent mRNA translation and synthesis of proteins involved in cell growth, cell proliferation, invasion and apoptosis evasion. The oncogenic potential of eIF4E is strictly dependent on serine209 phosphorylation by upstream MAPK-interacting kinases (Mnks). Targeting Mnk/eIF4E pathway for blocking Mnk function and eIF4E phosphorylation is therefore a novel approach for treating BCs, particularly for Her2-positive and triple negative breast cancers that have no indications for endocrine therapy or effective treatment regimes. We report for the first time that the degradation of Mnk1 by RRs in BC cells blocks eIF4E phosphorylation and subsequently inhibits cell growth, colonization, invasion, and migration and induce apoptosis. Most importantly, the anticancer efficacy of RRs was mediated via degrading Mnk rather than inhibiting its kinase activity like Mnk inhibitors (cercosporamide and CGP57380). Furthermore, RRs potencies on peIF4E down-regulation and growth inhibition were superior to those of two clinically relevant retinoids and the Mnk inhibitors. Together our findings provide the first preclinical proof-of-concept of novel Mnk degrading agents for Mnk/eIF4E based therapeutic treatment of breast cancers. PMID:24504069

  9. Clinical significance of glycoprotein nonmetastatic B and its association with HER2 in breast cancer

    PubMed Central

    Kanematsu, Masako; Futamura, Manabu; Takata, Masafumi; Gaowa, Siqin; Yamada, Atsuko; Morimitsu, Kasumi; Morikawa, Akemi; Mori, Ryutaro; Hara, Hideaki; Yoshida, Kazuhiro

    2015-01-01

    Glycoprotein nonmetastatic B (GPNMB) is a potential oncogene that is particularly expressed in melanoma and breast cancer (BC). To clarify its clinical significance in BC, we measured serum GPNMB in vivo and investigated its cross talk with human epidermal growth factor 2 (HER2). GPNMB was expressed in four of six breast cell lines (SK-BR-3, BT-474, MDA-MD-231, and MDA-MD-157), two of six colorectal cell lines, and two of four gastric cancer (GC) cell lines. We established a GPNMB quantification system using enzyme-linked immunosorbent assay (ELISA) for these cell lines. We measured serum GPNMB in vivo in 162 consecutive BC patients and in 88 controls (50 colorectal cancer [CC] and 38 GC patients). The GPNMB concentration in BC, CC and GC was 8.163, 5.751 and 6.55 ng/mL, respectively. The GPNMB level was significantly higher in BC patients than in CC patients (P = 0.021). The HER2-rich subtype of BC patients had significantly higher GPNMB levels than other subtypes (vs. Luminal; P = 0.038; vs. DCIS; P = 0.0195). These high GPNMB levels decreased after treatment (surgery/chemotherapy). Next, we examined the relationship between GPNMB and HER2 in vitro using SK-BR3 and BT-474 (HER2-positive/GPNMB-positive) cells. GPNMB depletion by small interfering RNA (siRNA) increased both HER2 expression and phosphorylation. Trastuzumab (Tra) in combination with docetaxel promoted cell growth inhibition, and treatment with Tra or an Extracellular signal-related kinase (ERK) inhibitor enhanced GPNMB expression. These results indicate that GPNMB might be a surrogate marker for BC and may cross talk with the HER2 signal pathway. GPNMB may therefore emerge as an important player in anti-HER2 therapy. PMID:26077887

  10. Decoupling of the PI3K pathway via mutation necessitates combinatorial treatment in HER2+ breast cancer

    SciTech Connect

    Korkola, James E.; Collisson, Eric A.; Heiser, Laura; Oates, Chris; Bayani, Nora; Itani, Sleiman; Esch, Amanda; Thompson, Wallace; Griffith, Obi L.; Wang, Nicholas J.; Kuo, Wen -Lin; Cooper, Brian; Billig, Jessica; Ziyad, Safiyyah; Hung, Jenny L.; Jakkula, Lakshmi; Feiler, Heidi; Lu, Yiling; Mills, Gordon B.; Spellman, Paul T.; Tomlin, Claire; Mukherjee, Sach; Gray, Joe W.; Wong, Kwong -Kwok

    2015-07-16

    We report here on experimental and theoretical efforts to determine how best to combine drugs that inhibit HER2 and AKT in HER2+ breast cancers. We accomplished this by measuring cellular and molecular responses to lapatinib and the AKT inhibitors (AKTi) GSK690693 and GSK2141795 in a panel of 22 HER2+ breast cancer cell lines carrying wild type or mutant PIK3CA. We observed that combinations of lapatinib plus AKTi were synergistic in HER2/PIK3CAmut cell lines but not in HER2+/PIK3CAwt cell lines. We measured changes in phospho-protein levels in 15 cell lines after treatment with lapatinib, AKTi or lapatinib + AKTi to shed light on the underlying signaling dynamics. This revealed that p-S6RP levels were less well attenuated by lapatinib in HER2+/PIK3CAmut cells compared to HER2+/PIK3CAwt cells and that lapatinib + AKTi reduced p-S6RP levels to those achieved in HER2+/PIK3CAwt cells with lapatinib alone. We also found that that compensatory up-regulation of p-HER3 and p-HER2 is blunted in PIK3CAmut cells following lapatinib + AKTi treatment. Responses of HER2+ SKBR3 cells transfected with lentiviruses carrying control or PIK3CAmut sequences were similar to those observed in HER2+/PIK3CAmut cell lines but not in HER2+/PIK3CAwt cell lines. We used a nonlinear ordinary differential equation model to support the idea that PIK3CA mutations act as downstream activators of AKT that blunt lapatinib inhibition of downstream AKT signaling and that the effects of PIK3CA mutations can be countered by combining lapatinib with an AKTi. This combination does not confer substantial benefit beyond lapatinib in HER2+/PIK3CAwt cells.

  11. Prolyl isomerase Pin1 is highly expressed in Her2-positive breast cancer and regulates erbB2 protein stability

    PubMed Central

    Lam, Prudence B; Burga, Laura N; Wu, Bryan P; Hofstatter, Erin W; Lu, Kun Ping; Wulf, Gerburg M

    2008-01-01

    Overexpression of HER-2/Neu occurs in about 25–30% of breast cancer patients and is indicative of poor prognosis. While Her2/Neu overexpression is primarily a result of erbB2 amplification, it has recently been recognized that erbB2 levels are also regulated on the protein level. However, factors that regulate Her2/Neu protein stability are less well understood. The prolyl isomerase Pin1 catalyzes the isomerization of specific pSer/Thr-Pro motifs that have been phosphorylated in response to mitogenic signaling. We have previously reported that Pin1-catalyzed post-phosphorylational modification of signal transduction modulates the oncogenic pathways downstream from c-neu. The goal of this study was to examine the expression of prolyl isomerase Pin1 in human Her2+ breast cancer, and to study if Pin1 affects the expression of Her2/Neu itself. Methods Immunohistochemistry for Her2 and Pin1 were performed on two hundred twenty-three human breast cancers, with 59% of the specimen from primary cancers and 41% from metastatic sites. Pin1 inhibition was achieved using siRNA in Her2+ breast cancer cell lines, and its effects were studied using cell viability assays, immunoblotting and immunofluorescence. Results Sixty-four samples (28.7%) stained positive for Her2 (IHC 3+), and 54% (122/223) of all breast cancers stained positive for Pin1. Of the Her2-positive cancers 40 (62.5%) were also Pin1-positive, based on strong nuclear or nuclear and cytoplasmic staining. Inhibition of Pin1 via RNAi resulted in significant suppression of Her2-positive tumor cell growth in BT474, SKBR3 and AU565 cells. Pin1 inhibition greatly increased the sensitivity of Her2-positive breast cancer cells to the mTOR inhibitor Rapamycin, while it did not increase their sensitivity to Trastuzumab, suggesting that Pin1 might act on Her2 signaling. We found that Pin1 interacted with the protein complex that contains ubiquitinated erbB2 and that Pin1 inhibition accelerated erbB2 degradation, which could

  12. Coregulation of Epidermal Growth Factor Receptor/Human Epidermal Growth Factor Receptor 2 (HER2) Levels and Locations: Quantitative Analysis of HER2 Overexpression Effects

    SciTech Connect

    Hendriks, Bart S.; Opresko, Lee; Wiley, H. S.; Lauffenburger, Douglas A.

    2003-03-01

    Elevated expression of human epidermal growth factor receptor 2 (HER2) is know to alter cell signalilng and behavioral responses implicated in tumor progression. However, multiple diverse mechanisms may be involved in these overall effects, including signaling by HER2 itself, modulation of signalilng by epidermal growth factor receptor (EGFR) and modification of trafficking dynamics for both EGFR and HER2. Continued....

  13. HOXB7 is an ERα cofactor in the activation of HER2 and multiple ER target genes leading to endocrine resistance

    PubMed Central

    Jin, Kideok; Park, Sunju; Teo, Wei Wen; Korangath, Preethi; Cho, Sean Soonweng; Yoshida, Takahiro; Győrffy, Balázs; Goswami, Chirayu Pankaj; Nakshatri, Harikrishna; Cruz, Leigh-Ann; Zhou, Weiqiang; Ji, Hongkai; Su, Ying; Ekram, Muhammad; Wu, Zhengsheng; Zhu, Tao; Polyak, Kornelia; Sukumar, Saraswati

    2015-01-01

    Why breast cancers become resistant to tamoxifen despite continued expression of the estrogen receptor alpha (ERα) and what factors are responsible for high HER2 expression in these tumors remains an enigma. HOXB7 ChIP analysis followed by validation showed that HOXB7 physically interacts with ERα, and that the HOXB7-ERα complex enhances transcription of many ERα target genes including HER2. Investigating strategies for controlling HOXB7, our studies revealed that MYC, stabilized via phosphorylation mediated by EGFR-HER2 signaling, inhibits transcription of miRNA-196a, a HOXB7 repressor. This leads to increased expression of HOXB7, ER-target genes and HER2. Repressing MYC using small molecule inhibitors reverses these events, and causes regression of breast cancer xenografts. The MYC-HOXB7-HER2 signaling pathway is eminently targetable in endocrine-resistant breast cancer. PMID:26180042

  14. Development and Characterization of a Humanized Anti-HER2 Antibody HuA21 with Potent Anti-Tumor Properties in Breast Cancer Cells

    PubMed Central

    Li, Ruilin; Hu, Siyi; Chang, Yan; Zhang, Zhihui; Zha, Zhao; Huang, Hui; Shen, Guodong; Liu, Jing; Song, Lihua; Wei, Wei

    2016-01-01

    Human epidermal growth factor receptor 2 (HER2) is one of the most studied tumor-associated antigens for cancer immunotherapy. An engineered anti-HER-2 chimeric A21 antibody (chA21) is a chimeric antibody targeted to subdomain I of the HER2 extracellular domain. Here, we report the anti-tumor activity of the novel engineered monoclonal antibody humanized chA21 (HuA21) that targets HER2 on the basis of chA21, and we describe the underlying mechanisms. Our results reveal that HuA21 markedly inhibits the proliferation and migration of HER2-overexpressing breast cancer cells and causes enhanced antibody-dependent cell-mediated cytotoxicity potency against HER2-overexpressing tumor cells. In particular, HuA21, but not trastuzumab (Tra), markedly suppresses growth and enhances the internalization of the antibody in Tra-resistant BT-474 breast cancer cells. These characteristics are highly associated with the intrinsic ability of HuA21 to down-regulate HER2 activation and inhibit the extracellular signal-regulated kinase 1/2 (ERK1/2) and protein kinase B (Akt) signaling pathways. Furthermore, the combination of HuA21 with Tra synergistically enhances the anti-tumor effects in vitro and in vivo and inhibits HER2 activation and the ERK1/2 and Akt signaling pathways. Altogether, our results suggest that HuA21 may represent a unique anti-HER2 antibody with potential as a therapeutic candidate alone or in combination with other anti-HER2 reagents in cancer therapy. PMID:27092488

  15. Development and Characterization of a Humanized Anti-HER2 Antibody HuA21 with Potent Anti-Tumor Properties in Breast Cancer Cells.

    PubMed

    Li, Ruilin; Hu, Siyi; Chang, Yan; Zhang, Zhihui; Zha, Zhao; Huang, Hui; Shen, Guodong; Liu, Jing; Song, Lihua; Wei, Wei

    2016-01-01

    Human epidermal growth factor receptor 2 (HER2) is one of the most studied tumor-associated antigens for cancer immunotherapy. An engineered anti-HER-2 chimeric A21 antibody (chA21) is a chimeric antibody targeted to subdomain I of the HER2 extracellular domain. Here, we report the anti-tumor activity of the novel engineered monoclonal antibody humanized chA21 (HuA21) that targets HER2 on the basis of chA21, and we describe the underlying mechanisms. Our results reveal that HuA21 markedly inhibits the proliferation and migration of HER2-overexpressing breast cancer cells and causes enhanced antibody-dependent cell-mediated cytotoxicity potency against HER2-overexpressing tumor cells. In particular, HuA21, but not trastuzumab (Tra), markedly suppresses growth and enhances the internalization of the antibody in Tra-resistant BT-474 breast cancer cells. These characteristics are highly associated with the intrinsic ability of HuA21 to down-regulate HER2 activation and inhibit the extracellular signal-regulated kinase 1/2 (ERK1/2) and protein kinase B (Akt) signaling pathways. Furthermore, the combination of HuA21 with Tra synergistically enhances the anti-tumor effects in vitro and in vivo and inhibits HER2 activation and the ERK1/2 and Akt signaling pathways. Altogether, our results suggest that HuA21 may represent a unique anti-HER2 antibody with potential as a therapeutic candidate alone or in combination with other anti-HER2 reagents in cancer therapy. PMID:27092488

  16. The anti-HER3 antibody in combination with trastuzumab exerts synergistic antitumor activity in HER2-positive gastric cancer.

    PubMed

    Wang, Qiwei; Zhang, Xiaotian; Shen, Enyun; Gao, Jing; Cao, Fengqi; Wang, Xiaojuan; Li, Yilin; Tian, Tiantian; Wang, Jingyuan; Chen, Zuhua; Wang, Jiayuan; Shen, Lin

    2016-09-28

    The anti-HER2 monoclonal antibody trastuzumab is central to the treatment of HER2-positive gastric cancer (GC); however, its responses are limited. HER3 seems to be the preferred dimerization partner with HER2 and is emerging as a key target for complete blockade of downstream pathways and better clinical response. In this study, we report that novel anti-HER3 antibodies (1A5-3D4) that can neutralize multiple modes of HER3 activation, combined with trastuzumab, exhibited synergistic inhibitory effect on the cell proliferation in HER2-positive GC cell lines. Follow-up studies revealed that the combination treatment significantly inhibited phosphorylation of HER3 as well as AKT and ERK signals. In vivo experiments further showed that the anti-tumor effect of trastuzumab was enhanced by its combination with 1A5-3D4 in NCI-N87 xenograft and patient derived xenografts (PDX). Particularly in an HER2-negative whereas neuregulin1 (a ligand of HER3) positive PDX, the combination was also superior to monotherapy. 1A5-3D4 in combination with trastuzumab exhibits a synergistic inhibitory effect on tumor activity, suggesting that targeting both HER2 and HER3 resulted in an improved treatment effects on HER2-positive GC. PMID:27317872

  17. HER2 specific delivery of methotrexate by dendrimer conjugated anti-HER2 mAb

    NASA Astrophysics Data System (ADS)

    Shukla, Rameshwer; Thomas, Thommey P.; Desai, Ankur M.; Kotlyar, Alina; Park, Steve J.; Baker, James R., Jr.

    2008-07-01

    Herceptin, a humanized monoclonal antibody that binds to human growth factor receptor-2 (HER2), was covalently attached to a fifth-generation (G5) polyamidoamine dendrimer containing the cytotoxic drug methotrexate. The specific binding and internalization of this conjugate labeled with FITC was clearly demonstrated in cell lines overexpressing HER2 by flow cytometry as well as confocal microscopic analysis. In addition, binding and uptake of antibody conjugated dendrimers was completely blocked by excess non-conjugated herceptin. The dendrimer conjugate was also shown to inhibit the dihydrofolate reductase with similar activity to methotrexate. Co-localization experiments with lysotracker red indicate that antibody conjugate, although internalized efficiently into cells, has an unusually long residence time in the lysosome. Somewhat lower cytotoxicity of the conjugate in comparison to free methotrexate was attributed to the slow release of methotrexate from the conjugate and its long retention in the lysosomal pocket.

  18. Antiproliferative effects of γ-tocotrienol are associated with lipid raft disruption in HER2-positive human breast cancer cells.

    PubMed

    Alawin, Osama A; Ahmed, Rayan A; Ibrahim, Baher A; Briski, Karen P; Sylvester, Paul W

    2016-01-01

    A large percentage of human breast cancers are characterized by excessive or aberrant HER2 activity. Lipid rafts are specialized microdomains within the plasma membrane that are required for HER2 activation and signal transduction. Since the anticancer activity of γ-tocotrienol is associated with suppression in HER2 signaling, studies were conducted to examine the effects of γ-tocotrienol on HER2 activation within the lipid raft microdomain in HER2-positive SKBR3 and BT474 human breast cancer cells. Treatment with 0-5μM γ-tocotrienol induced a significant dose-dependent inhibition in cancer cell growth after a 5-day culture period, and these growth inhibitory effects were associated with a reduction in HER2 dimerization and phosphorylation (activation). Phosphorylated HER2 was found to be primarily located in the lipid raft microdomain of the plasma membrane in vehicle-treated control groups, whereas γ-tocotrienol treatment significantly inhibited this effect. Assay of plasma membrane subcellular fractions showed that γ-tocotrienol also accumulates exclusively within the lipid raft microdomain. Hydroxypropyl-β-cyclodextrin (HPβCD) is an agent that disrupts lipid raft integrity. Acute exposure to 3mM HPβCD alone had no effect, whereas an acute 24-h exposure to 20μM γ-tocotrienol alone significantly decreased SKBR3 and BT474 cell viability. However, combined treatment with these agents greatly reduced γ-tocotrienol accumulation in the lipid raft microdomain and cytotoxicity. In summary, these findings demonstrate that the anticancer effects of γ-tocotrienol are associated with its accumulation in the lipid raft microdomain and subsequent interference with HER2 dimerization and activation in SKBR3 and BT474 human breast cancer cells. PMID:26507543

  19. A critical role for HER3 in HER2-amplified and non-amplified breast cancers: function of a kinase-dead RTK.

    PubMed

    Dey, Nandini; Williams, Casey; Leyland-Jones, Brain; De, Pradip

    2015-01-01

    ERBB3/HER3 is the most intriguing RTK by virtue of its ability to transduce multiple cytosolic signals for the proliferation and growth of tumor cells in spite of being a "kinase dead" receptor that binds to its true ligand, heregulin. Although other members of the HER3 family like EGFR and HER2 have long been recognized to be associated with breast tumorigenesis and studied because of their predictive and prognostic value, the significance of HER3 as an irrefutable component of HER family signalosome is a relatively new development. The recent understanding of signals originating from the oncogenic partnership of HER3 with HER2 in the context of HER2 amplification/overexpression showed the critical clinical value for the treatment of HER2+BC. The downstream signaling cascade (included but not limited to the PI3K signaling) associated with signals originating from HER2:HER3 dimers play a vital role in the tumorigenesis, drug-resistance and tumor progression of HER2+BC. The upregulation of HER3 activity provides an alternate "escape route" via which tumor cells bypass either the inhibition of the HER family RTKs or the inhibition of the downstream PI3K-AKT-mTOR signaling pathway. By understanding the signaling that provides this "escape route" for these tumor cells treated with a targeted therapy (HER2 inhibitors or inhibitors of downstream PI3K-AKT-mTOR signaling pathway), we are just beginning to appreciate the prognostic value of HER3 in breast cancer. In this review, we will discuss the relevance of HER3 signaling in the context of, (1) downstream oncogenic signals and (2) therapeutic options in HER2 amplified BC. PMID:26064441

  20. A critical role for HER3 in HER2-amplified and non-amplified breast cancers: function of a kinase-dead RTK

    PubMed Central

    Dey, Nandini; Williams, Casey; Leyland-Jones, Brain; De, Pradip

    2015-01-01

    ERBB3/HER3 is the most intriguing RTK by virtue of its ability to transduce multiple cytosolic signals for the proliferation and growth of tumor cells in spite of being a “kinase dead” receptor that binds to its true ligand, heregulin. Although other members of the HER3 family like EGFR and HER2 have long been recognized to be associated with breast tumorigenesis and studied because of their predictive and prognostic value, the significance of HER3 as an irrefutable component of HER family signalosome is a relatively new development. The recent understanding of signals originating from the oncogenic partnership of HER3 with HER2 in the context of HER2 amplification/overexpression showed the critical clinical value for the treatment of HER2+BC. The downstream signaling cascade (included but not limited to the PI3K signaling) associated with signals originating from HER2:HER3 dimers play a vital role in the tumorigenesis, drug-resistance and tumor progression of HER2+BC. The upregulation of HER3 activity provides an alternate “escape route” via which tumor cells bypass either the inhibition of the HER family RTKs or the inhibition of the downstream PI3K-AKT-mTOR signaling pathway. By understanding the signaling that provides this “escape route” for these tumor cells treated with a targeted therapy (HER2 inhibitors or inhibitors of downstream PI3K-AKT-mTOR signaling pathway), we are just beginning to appreciate the prognostic value of HER3 in breast cancer. In this review, we will discuss the relevance of HER3 signaling in the context of, (1) downstream oncogenic signals and (2) therapeutic options in HER2 amplified BC. PMID:26064441

  1. TGIF inhibits retinoid signaling.

    PubMed

    Bartholin, Laurent; Powers, Shannon E; Melhuish, Tiffany A; Lasse, Samuel; Weinstein, Michael; Wotton, David

    2006-02-01

    TGIF (TG-interacting factor) represses transforming growth factor beta (TGF-beta)-activated gene expression and can repress transcription via a specific retinoid response element. Mutations in human TGIF are associated with holoprosencephaly, a severe defect of craniofacial development with both genetic and environmental causes. Both TGF-beta and retinoic acid signaling are implicated in craniofacial development. Here, we analyze the role of TGIF in regulating retinoid responsive gene expression. We demonstrate that TGIF interacts with the ligand binding domain of the RXRalpha retinoid receptor and represses transcription from retinoid response elements. TGIF recruits the general corepressor, CtBP, to RXRalpha, and this recruitment is required for full repression by TGIF. Interaction between TGIF and RXRalpha is reduced by the addition of retinoic acid, consistent with a role for TGIF as an RXRalpha transcriptional corepressor. We created a Tgif null mutation in mice and tested the sensitivity of mutant mice to increased levels of retinoic acid. Tgif mutant embryos are more sensitive to retinoic acid-induced teratogenesis, and retinoid target genes are expressed at a higher level in tissues from Tgif null mice. These results demonstrate an important role for TGIF as a transcriptional corepressor, which regulates developmental signaling by retinoic acid, and raises the possibility that TGIF may repress other RXR-dependent transcriptional responses. PMID:16428452

  2. Identifying HER2 Inhibitors from Natural Products Database

    PubMed Central

    Yang, Shun-Chieh; Chang, Su-Sen; Chen, Calvin Yu-Chian

    2011-01-01

    The relationship between abnormal HER2 expression and cancer is important in cancer therapeutics. Formation and spread of cancer cells may be restricted by inhibiting HER2. We conducted ligand-based and structure-based studies to assess the potency of natural compounds as potential HER2 inhibitors. Multiple linear regression (MLR) and support vector machine (SVM) models were constructed to predict biological activities of natural compounds, and molecular dynamics (MD) was used to assess their stability with HER2 under a dynamic environment. Predicted bioactivities of the natural compounds ranged from 6.014–9.077 using MLR (r2 = 0.7954) and 5.122–6.950 using SVM (r2 = 0.8620). Both models were in agreement and suggest bioactivity based on candidate structure. Conformation changes caused by MD favored the formation of stabilizing H-bonds. All candidates had higher stability than Lapinatib, which may be due to the number and spatial distribution of additional H-bonds and hydrophobic interactions. Amino acids Lys724 and Lys736 are critical for binding in HER2, and Thr798, Cys805, and Asp808 are also important for increased stability. Candidates may block the entrance to the ATP binding site located within the inner regions and prevent downstream activation of HER2. Our multidirectional approach indicates that the natural compounds have good ligand efficacy in addition to stable binding affinities to HER2, and should be potent candidates of HER2 inhibitors. With regard to drug design, designing HER2 inhibitors with carboxyl or carbonyl groups available for H-bond formation with Lys724 and Lys736, and benzene groups for hydrophobic contact with Cys805 may improve protein-ligand stability. PMID:22174899

  3. PGC-1β regulates HER2-overexpressing breast cancer cells proliferation by metabolic and redox pathways.

    PubMed

    Victorino, Vanessa Jacob; Barroso, W A; Assunção, A K M; Cury, V; Jeremias, I C; Petroni, R; Chausse, B; Ariga, S K; Herrera, A C S A; Panis, C; Lima, T M; Souza, H P

    2016-05-01

    Breast cancer is a prevalent neoplastic disease among women worldwide which treatments still present several side effects and resistance. Considering that cancer cells present derangements in their energetic homeostasis, and that peroxisome proliferator-activated receptor- gamma coactivator 1 (PGC-1) is crucial for cellular metabolism and redox signaling, the main objective of this study was to investigate whether there is a relationship between PGC-1 expression, the proliferation of breast cancer cells and the mechanisms involved. We initially assessed PGC-1β expression in complementary DNA (cDNA) from breast tumor of patients bearing luminal A, luminal B, and HER2-overexpressed and triple negative tumors. Our data showed that PGC-1β expression is increased in patients bearing HER2-overexpressing tumors as compared to others subtypes. Using quantitative PCR and immunoblotting, we showed that breast cancer cells with HER2-amplification (SKBR-3) have greater expression of PGC-1β as compared to a non-tumorous breast cell (MCF-10A) and higher proliferation rate. PGC-1β expression was knocked down with short interfering RNA in HER2-overexpressing cells, and cells decreased proliferation. In these PGC-1β-inhibited cells, we found increased citrate synthase activity and no marked changes in mitochondrial respiration. Glycolytic pathway was decreased, characterized by lower intracellular lactate levels. In addition, after PGC-1β knockdown, SKBR-3 cells showed increased reactive oxygen species production, no changes in antioxidant activity, and decreased expression of ERRα, a modulator of metabolism. In conclusion, we show an association of HER2-overexpression and PGC-1β. PGC-1β knockdown impairs HER2-overexpressing cells proliferation acting on ERRα signaling, metabolism, and redox balance. PMID:26602383

  4. HER2/CEP17 Ratios and Clinical Outcome in HER2-Positive Early Breast Cancer Undergoing Trastuzumab-Containing Therapy

    PubMed Central

    Stocker, Albina; Hilbers, Marie-Luise; Gauthier, Claire; Grogg, Josias; Kullak-Ublick, Gerd A.; Seifert, Burkhardt; Varga, Zsuzsanna

    2016-01-01

    Background Adjuvant therapy comprising the HER2 receptor antagonist trastuzumab is associated with a significant improvement in disease-free and overall survival as compared to chemotherapy alone in localized HER2-positive breast cancer (BC). However, a subset of HER2-positive tumors seems to respond less favorably to trastuzumab. Various mechanisms have been proposed for trastuzumab resistance, such as high HER2 to Chromosome 17 FISH (HER2/CEP17) ratios and the possibility that single agent trastuzumab may not suffice to efficiently block HER2 downstream signaling thresholds. In a retrospective analysis we evaluated whether HER2/CEP17 ratios might have an impact on disease-free survival (DFS). Methods Clinical records of Stage I-III BC patients with HER2-positive tumors were reviewed at our institution from 2007–2013. We analyzed demographics, tumor characteristics including tumor size and grade, lymph node involvement and estrogen receptor expression as well as treatment with respect to chemotherapeutic regimens from the clinical charts. HER2/CEP17 ratios were determined by routine pathology analysis using in situ fluorescent hybridization (FISH). Upon statistical preview we defined three groups of HER2 amplification based on FISH ratio (2.2 to 4, >4 to 8, >8), in order to evaluate an association between HER2 gene amplification and DFS with trastuzumab containing therapies. DFS was analyzed using Cox-regression. Results A total of 332 patients with HER2-positive BC were reviewed. Median age was 54 (range 23–89) years. The majority of tumors were classified T1 (50%) or T2 (39%), node negative (52%) and of high grade G3 histology (70%). We identified 312 (94%) tumors as immunohistochemistry (IHC) score 3+ and HER2/CEP17 ratios were available from 278 patients (84%). 30% (N = 84) had tumors with high HER2/CEP17 ratios (>8). Univariate analysis found no correlation between outcome, age, histological grade, sequence as well as anthracycline content of chemotherapy

  5. Targeting Three Distinct HER2 Domains with a Recombinant Antibody Mixture Overcomes Trastuzumab Resistance.

    PubMed

    Pedersen, Mikkel W; Jacobsen, Helle J; Koefoed, Klaus; Dahlman, Anna; Kjær, Ida; Poulsen, Thomas T; Meijer, Per-Johan; Nielsen, Lars S; Horak, Ivan D; Lantto, Johan; Kragh, Michael

    2015-03-01

    HER2 plays an important role in the development and maintenance of the malignant phenotype of several human cancers. As such, it is a frequently pursued therapeutic target and two antibodies targeting HER2 have been clinically approved, trastuzumab and pertuzumab. It has been suggested that optimal inhibition of HER2 is achieved when utilizing two or more antibodies targeting nonoverlapping epitopes. Superior clinical activity of the trastuzumab plus pertuzumab combination in metastatic breast cancer supports this hypothesis. Because trastuzumab and pertuzumab were not codeveloped, there may be potential for further optimizing HER2 targeting. The study herein evaluated functional activity of anti-HER2 antibody combinations identifying optimal epitope combinations that provide efficacious HER2 inhibition. High-affinity antibodies to all four extracellular domains on HER2 were identified and tested for ability to inhibit growth of different HER2-dependent tumor cell lines. An antibody mixture targeting three HER2 subdomains proved to be superior to trastuzumab, pertuzumab, or a combination in vitro and to trastuzumab in two in vivo models. Specifically, the tripartite antibody mixture induced efficient HER2 internalization and degradation demonstrating increased sensitivity in cell lines with HER2 amplification and high EGFR levels. When compared with individual and clinically approved mAbs, the synergistic tripartite antibody targeting HER2 subdomains I, II, and IV demonstrates superior anticancer activity. PMID:25612619

  6. High cell-surface density of HER2 deforms cell membranes.

    PubMed

    Chung, Inhee; Reichelt, Mike; Shao, Lily; Akita, Robert W; Koeppen, Hartmut; Rangell, Linda; Schaefer, Gabriele; Mellman, Ira; Sliwkowski, Mark X

    2016-01-01

    Breast cancers (BC) with HER2 overexpression (referred to as HER2 positive) progress more aggressively than those with normal expression. Targeted therapies against HER2 can successfully delay the progression of HER2-positive BC, but details of how this overexpression drives the disease are not fully understood. Using single-molecule biophysical approaches, we discovered a new effect of HER2 overexpression on disease-relevant cell biological changes in these BC. We found HER2 overexpression causes deformation of the cell membranes, and this in turn disrupts epithelial features by perturbing cell-substrate and cell-cell contacts. This membrane deformation does not require receptor signalling activities, but results from the high levels of HER2 on the cell surface. Our finding suggests that early-stage morphological alterations of HER2-positive BC cells during cancer progression can occur in a physical and signalling-independent manner. PMID:27599456

  7. Prolonged Response to Trastuzumab in a Patient With HER2-Nonamplified Breast Cancer With Elevated HER2 Dimerization Harboring an ERBB2 S310F Mutation.

    PubMed

    Chumsri, Saranya; Weidler, Jodi; Ali, Siraj; Balasubramanian, Sohail; Wallweber, Gerald; DeFazio-Eli, Lisa; Chenna, Ahmed; Huang, Weidong; DeRidder, Angela; Goicocheal, Lindsay; Perez, Edith A

    2015-09-01

    In the current genomic era, increasing evidence demonstrates that approximately 2% of HER2-negative breast cancers, by current standard testings, harbor activating mutations of ERBB2. However, whether patients with HER2-negative breast cancer with activating mutations of ERBB2 also experience response to anti-HER2 therapies remains unclear. This case report describes a patient with HER2-nonamplified heavily pretreated breast cancer who experienced prolonged response to trastuzumab in combination with pertuzumab and fulvestrant. Further molecular analysis demonstrated that her tumors had an elevated HER2 dimerization that corresponded to ERBB2 S310F mutation. Located in the extracellular domain of the HER2 protein, this mutation was reported to promote noncovalent dimerization that results in the activation of the downstream signaling pathways. This case highlights the fact that HER2-targeted therapy may be valuable in patients harboring an ERBB2 S310F mutation. PMID:26358791

  8. The EGFR-HER2 module: a stem cell approach to understanding a prime target and driver of solid tumors

    PubMed Central

    Schneider, Marlon R.; Yarden, Yosef

    2015-01-01

    The epidermal growth factor receptor (EGFR) and a co-receptor denoted HER2/ERBB2, are frequently overexpressed or mutated in solid tumors, such as carcinomas and gliomas. In line with driver roles, cancer drugs intercepting EGFR or HER2 currently outnumber therapies targeting other hubs of signal transduction. To explain the roles for EGFR and HER2 as prime drivers and targets, we take lessons from invertebrates and refer to homeostatic regulation of several mammalian tissues. The model we infer ascribes to the EGFR-HER2 module pivotal functions in rapid clonal expansion of progenitors called transient amplifying cells (TACs). Accordingly, TACs of tumors suffer from replication stress, hence accumulate mutations. In addition, several lines of evidence propose that in response to EGF and related mitogens, TACs might undergo de-differentiation into tissue stem cells, which might enable entry of oncogenic mutations into the stem cell compartment. According to this view, antibodies or kinase inhibitors targeting EGFR-HER2 effectively retard some solid tumors because they arrest mutation-enriched TACs and possibly inhibit their dedifferentiation. Deeper understanding of the EGFR-HER2 module and relations between cancer stem cells and TACs will enhance our ability to control a broad spectrum of human malignancies. PMID:26434585

  9. The EGFR-HER2 module: a stem cell approach to understanding a prime target and driver of solid tumors.

    PubMed

    Schneider, M R; Yarden, Y

    2016-06-01

    The epidermal growth factor receptor (EGFR) and a coreceptor denoted HER2/ERBB2 are frequently overexpressed or mutated in solid tumors, such as carcinomas and gliomas. In line with driver roles, cancer drugs intercepting EGFR or HER2 currently outnumber therapies targeting other hubs of signal transduction. To explain the roles for EGFR and HER2 as prime drivers and targets, we take lessons from invertebrates and refer to homeostatic regulation of several mammalian tissues. The model we infer ascribes to the EGFR-HER2 module pivotal functions in rapid clonal expansion of progenitors called transient amplifying cells (TACs). Accordingly, TACs of tumors suffer from replication stress, and hence accumulate mutations. In addition, several lines of evidence propose that in response to EGF and related mitogens, TACs might undergo dedifferentiation into tissue stem cells, which might enable entry of oncogenic mutations into the stem cell compartment. According to this view, antibodies or kinase inhibitors targeting EGFR-HER2 effectively retard some solid tumors because they arrest mutation-enriched TACs and possibly inhibit their dedifferentiation. Deeper understanding of the EGFR-HER2 module and relations between cancer stem cells and TACs will enhance our ability to control a broad spectrum of human malignancies. PMID:26434585

  10. HER2 and uPAR cooperativity contribute to metastatic phenotype of HER2-positive breast cancer

    PubMed Central

    Chandran, Vineesh Indira; Eppenberger-Castori, Serenella; Venkatesh, Thejaswini; Vine, Kara Lea; Ranson, Marie

    2015-01-01

    Human epidermal growth factor receptor type 2 (HER2)-positive breast carcinoma is highly aggressive and mostly metastatic in nature though curable/manageable in part by molecular targeted therapy. Recent evidence suggests a subtype of cells within HER2-positive breast tumors that concomitantly expresses the urokinase plasminogen activator receptor (uPAR) with inherent stem cell/mesenchymal-like properties promoting tumor cell motility and a metastatic phenotype. This HER-positive/uPAR-positive subtype may be partially responsible for the failure of HER2-targeted treatment strategies. Herein we discuss and substantiate the cumulative preclinical and clinical evidence on HER2-uPAR cooperativity in terms of gene co-amplification and/or mRNA/protein co-overexpression. We then propose a regulatory signaling model that we hypothesize to maintain upregulation and cooperativity between HER2 and uPAR in aggressive breast cancer. An improved understanding of the HER2/uPAR interaction in breast cancer will provide critical biomolecular information that may help better predict disease course and response to therapy. PMID:25897424

  11. Human Epidermal Growth Factor Receptor 2 (HER2) in Cancers: Overexpression and Therapeutic Implications

    PubMed Central

    Iqbal, Nida; Iqbal, Naveed

    2014-01-01

    Human epidermal growth factor receptor 2 (HER2) is a member of the epidermal growth factor receptor family having tyrosine kinase activity. Dimerization of the receptor results in the autophosphorylation of tyrosine residues within the cytoplasmic domain of the receptors and initiates a variety of signaling pathways leading to cell proliferation and tumorigenesis. Amplification or overexpression of HER2 occurs in approximately 15–30% of breast cancers and 10–30% of gastric/gastroesophageal cancers and serves as a prognostic and predictive biomarker. HER2 overexpression has also been seen in other cancers like ovary, endometrium, bladder, lung, colon, and head and neck. The introduction of HER2 directed therapies has dramatically influenced the outcome of patients with HER2 positive breast and gastric/gastroesophageal cancers; however, the results have been proved disappointing in other HER2 overexpressing cancers. This review discusses the role of HER2 in various cancers and therapeutic modalities available targeting HER2. PMID:25276427

  12. Suppression of tumor angiogenesis by metformin treatment via a mechanism linked to targeting of HER2/HIF-1α/VEGF secretion axis

    PubMed Central

    Wang, Yaochun; Tang, Shouching; Sun, Xin; Feng, Xuefei; Li, Yan; Bao, Gang; Li, Pingping; Mao, Xiaona; Wang, Maode; Liu, Peijun

    2015-01-01

    Anti-angiogenesis is currently considered as one of the major antitumor strategies for its protective effects against tumor emergency and later progression. The anti-diabetic drug metformin has been demonstrated to significantly inhibit tumor angiogenesis based on recent studies. However, the mechanism underlying this anti-angiogenic effect still remains an enigma. In this study, we investigated metformin-induced inhibitory effect on tumor angiogenesis in vitro and in vivo. Metformin pretreatment significantly suppressed tumor paracrine signaling-induced angiogenic promotion even in the presence of heregulin (HRG)-β1 (a co-activator of HER2) pretreatment of HER2+ tumor cells. Similar to that of AG825, a specific inhibitor of HER2 phosphorylation, metformin treatment decreased both total and phosphorylation (Tyr 1221/1222) levels of HER2 protein and significantly reduced microvessel density and the amount of Fitc-conjugated Dextran leaking outside the vessel. Furthermore, our results of VEGF-neutralizing and -rescuing tests showed that metformin markedly abrogated HER2 signaling-induced tumor angiogenesis by inhibiting VEGF secretion. Inhibition of HIF-1α signaling by using RNAi or YC-1, a specific inhibitor of HIF-1α synthesis, both completely diminished mRNA level of VEGF and greatly inhibited endothelial cell proliferation promoted by HER2+ tumor cell-conditioned medium in both the absence and presence of HRG-β1 pretreatment. Importantly, metformin treatment decreased the number of HIF-1α nucleus positive cells in 4T1 tumors, accompanied by decreased microvessel density. Our data thus provides novel insight into the mechanism underlying the metformin-induced inhibition of tumor angiogenesis and indicates possibilities of HIF-1α-VEGF signaling axis in mediating HER2-induced tumor angiogenesis. PMID:26625311

  13. Suppression of tumor angiogenesis by metformin treatment via a mechanism linked to targeting of HER2/HIF-1α/VEGF secretion axis.

    PubMed

    Wang, Jichang; Li, Guangyue; Wang, Yaochun; Tang, Shouching; Sun, Xin; Feng, Xuefei; Li, Yan; Bao, Gang; Li, Pingping; Mao, Xiaona; Wang, Maode; Liu, Peijun

    2015-12-29

    Anti-angiogenesis is currently considered as one of the major antitumor strategies for its protective effects against tumor emergency and later progression. The anti-diabetic drug metformin has been demonstrated to significantly inhibit tumor angiogenesis based on recent studies. However, the mechanism underlying this anti-angiogenic effect still remains an enigma. In this study, we investigated metformin-induced inhibitory effect on tumor angiogenesis in vitro and in vivo. Metformin pretreatment significantly suppressed tumor paracrine signaling-induced angiogenic promotion even in the presence of heregulin (HRG)-β1 (a co-activator of HER2) pretreatment of HER2+ tumor cells. Similar to that of AG825, a specific inhibitor of HER2 phosphorylation, metformin treatment decreased both total and phosphorylation (Tyr 1221/1222) levels of HER2 protein and significantly reduced microvessel density and the amount of Fitc-conjugated Dextran leaking outside the vessel. Furthermore, our results of VEGF-neutralizing and -rescuing tests showed that metformin markedly abrogated HER2 signaling-induced tumor angiogenesis by inhibiting VEGF secretion. Inhibition of HIF-1α signaling by using RNAi or YC-1, a specific inhibitor of HIF-1α synthesis, both completely diminished mRNA level of VEGF and greatly inhibited endothelial cell proliferation promoted by HER2+ tumor cell-conditioned medium in both the absence and presence of HRG-β1 pretreatment. Importantly, metformin treatment decreased the number of HIF-1α nucleus positive cells in 4T1 tumors, accompanied by decreased microvessel density. Our data thus provides novel insight into the mechanism underlying the metformin-induced inhibition of tumor angiogenesis and indicates possibilities of HIF-1α-VEGF signaling axis in mediating HER2-induced tumor angiogenesis. PMID:26625311

  14. HER2 and HER3 cooperatively regulate cancer cell growth and determine sensitivity to the novel investigational EGFR/HER2 kinase inhibitor TAK-285.

    PubMed

    Takagi, Shinji; Banno, Hiroshi; Hayashi, Akira; Tamura, Toshiya; Ishikawa, Tomoyasu; Ohta, Yoshikazu

    2014-01-01

    The human epidermal growth factor receptor (HER) family plays a major role in cancer cell proliferation. Overexpression of these receptors occurs in various cancers, including breast cancer, and correlates with shorter time to relapse and lower overall survival. We recently reported that TAK-285, an orally bioavailable small molecule inhibitor of HER kinases, is not a p-glycoprotein substrate and penetrates the blood-brain barrier, suggesting favorable activity for the treatment of brain metastases. To identify the determinants of sensitivity to TAK-285, we examined the relationship between the IC50 values of TAK-285 for cell growth inhibition and the expression of candidate genes that are involved in the HER family signaling pathway and trastuzumab resistance in a panel of human breast cancer cell lines, other types of cancer cells, and non-transformed cells in vitro. These analyses showed an inverse correlation between sensitivity to TAK-285 (IC50 values) and HER2 or HER3 expression. HER3 was highly phosphorylated in TAK-285-sensitive cells, where TAK-285 treatment reduced HER3 phosphorylation level. Because HER3 does not possess kinase activity and a selective inhibitor of HER2 but not of an epidermal growth factor receptor reduced the phospho-HER3 level, HER3 was suggested to be trans-phosphorylated by HER2. HER3 knockdown using small interfering RNA (siRNA) inhibited cancer cell growth in TAK-285-sensitive cells but not in TAK-285-insensitive cells. These results suggest that HER2 and HER3 mainly regulate cancer cell growth in TAK-285-sensitive cells and that phospho-HER3 could be used as a potential molecular marker to select patients most likely to respond to TAK-285. PMID:25594012

  15. Active targeting using HER-2-affibody-conjugated nanoparticles enabled sensitive and specific imaging of orthotopic HER-2 positive ovarian tumors.

    PubMed

    Satpathy, Minati; Wang, Liya; Zielinski, Rafal; Qian, Weiping; Lipowska, Malgorzata; Capala, Jacek; Lee, Gee Young; Xu, Hong; Wang, Y Andrew; Mao, Hui; Yang, Lily

    2014-02-12

    Despite advances in cancer diagnosis and treatment, ovarian cancer remains one of the most fatal cancer types. The development of targeted nanoparticle imaging probes and therapeutics offers promising approaches for early detection and effective treatment of ovarian cancer. In this study, HER-2 targeted magnetic iron oxide nanoparticles (IONPs) are developed by conjugating a high affinity and small size HER-2 affibody that is labeled with a unique near infrared dye (NIR-830) to the nanoparticles. Using a clinically relevant orthotopic human ovarian tumor xenograft model, it is shown that HER-2 targeted IONPs are selectively delivered into both primary and disseminated ovarian tumors, enabling non-invasive optical and MR imaging of the tumors as small as 1 mm in the peritoneal cavity. It is determined that HER-2 targeted delivery of the IONPs is essential for specific and sensitive imaging of the HER-2 positive tumor since we are unable to detect the imaging signal in the tumors following systemic delivery of non-targeted IONPs into the mice bearing HER-2 positive SKOV3 tumors. Furthermore, imaging signals and the IONPs are not detected in HER-2 low expressing OVCAR3 tumors after systemic delivery of HER-2 targeted-IONPs. Since HER-2 is expressed in a high percentage of ovarian cancers, the HER-2 targeted dual imaging modality IONPs have potential for the development of novel targeted imaging and therapeutic nanoparticles for ovarian cancer detection, targeted drug delivery, and image-guided therapy and surgery. PMID:24038985

  16. Carboplatin+Nab-paclitaxel, Plus Trastuzumab (HER2+) or Bevacizumab (HER2-) in the Neoadjuvant Setting

    ClinicalTrials.gov

    2014-03-03

    Breast Cancer; HER2-negative Breast Cancer; HER2-positive Breast Cancer; Recurrent Breast Cancer; Stage IA Breast Cancer; Stage IB Breast Cancer; Stage II Breast Cancer; Stage IIIA Breast Cancer; Stage IIIB Breast Cancer; Stage IIIC Breast Cancer

  17. Notch promotes recurrence of dormant tumor cells following HER2/neu-targeted therapy.

    PubMed

    Abravanel, Daniel L; Belka, George K; Pan, Tien-chi; Pant, Dhruv K; Collins, Meredith A; Sterner, Christopher J; Chodosh, Lewis A

    2015-06-01

    Breast cancer mortality is principally due to recurrent tumors that arise from a reservoir of residual tumor cells that survive therapy. Remarkably, breast cancers can recur after extended periods of clinical remission, implying that at least some residual tumor cells pass through a dormant phase prior to relapse. Nevertheless, the mechanisms that contribute to breast cancer recurrence are poorly understood. Using a mouse model of recurrent mammary tumorigenesis in combination with bioinformatics analyses of breast cancer patients, we have identified a role for Notch signaling in mammary tumor dormancy and recurrence. Specifically, we found that Notch signaling is acutely upregulated in tumor cells following HER2/neu pathway inhibition, that Notch signaling remains activated in a subset of dormant residual tumor cells that persist following HER2/neu downregulation, that activation of Notch signaling accelerates tumor recurrence, and that inhibition of Notch signaling by either genetic or pharmacological approaches impairs recurrence in mice. Consistent with these findings, meta-analysis of microarray data from over 4,000 breast cancer patients revealed that elevated Notch pathway activity is independently associated with an increased rate of recurrence. Together, these results implicate Notch signaling in tumor recurrence from dormant residual tumor cells and provide evidence that dormancy is a targetable stage of breast cancer progression. PMID:25961456

  18. Altered S-nitrosothiol homeostasis provides a survival advantage to breast cancer cells in HER2 tumors and reduces their sensitivity to trastuzumab.

    PubMed

    Cañas, Amanda; López-Sánchez, Laura M; Peñarando, Jon; Valverde, Araceli; Conde, Francisco; Hernández, Vanessa; Fuentes, Elena; López-Pedrera, Chary; de la Haba-Rodríguez, Juan R; Aranda, Enrique; Rodríguez-Ariza, Antonio

    2016-04-01

    The monoclonal antibody trastuzumab against HER2/neu, which is overexpressed in 15-20% of breast cancers, has clinical efficacy but many patients do not respond to initial treatment or develop resistance during treatment. Nitric oxide (NO) regulates cell signaling by targeting specific cysteine residues in proteins, forming S-nitrosothiols (SNO) in a process known as S-nitrosylation. We previously reported that molecular characteristics in breast cancer may dictate the tumor response to impaired SNO homeostasis. In the present study, we explored the role of SNO homeostasis in HER2 breast tumors. The antiproliferative action of trastuzumab in HER2-overexpressing BT-474 and SKBR-3 cells was suppressed when S-nitrosoglutathione reductase (GSNOR/ADH5) activity, which plays a key role in SNO homeostasis, was specifically inhibited with the pyrrole derivative compound N6022. Moreover, GSNOR inhibition restored the activation of survival signaling pathways involved in the resistance to anti-HER2 therapies (AKT, Src and c-Abl kinases and TrkA/NRTK1, TrkB/NRTK2, EphA1 and EphA3 receptors) and reduced the apoptotic effect of trastuzumab. Accordingly, GSNOR inhibition augmented the S-nitrosylation of apoptosis-related proteins, including Apaf-1, pSer73/63 c-Jun, calcineurin subunit α and HSF1. In agreement with in vitro data, immunohistochemical analyses of 51 breast tumors showed that HER2 expression was associated with lower expression of GSNOR protein. Moreover, gene expression analysis confirmed that high ADH5/GSNOR gene expression was associated with high patient survival rates in HER2 tumors. In conclusion, our data provide evidence of molecular mechanisms contributing to the progression of HER2+ breast cancers and could facilitate the development of therapeutic options to counteract resistance to anti-HER2 therapies. PMID:26854735

  19. Glycoengineered Pichia produced anti-HER2 is comparable to trastuzumab in preclinical study

    PubMed Central

    Zhang, Ningyan; Liu, Liming; Dumitru, Calin Dan; Cummings, Nga Rewa Houston; Cukan, Michael; Jiang, Youwei; Li, Yuan; Li, Fang; Mitchell, Teresa; Mallem, Muralidhar R; Ou, Yangsi; Patel, Rohan N; Vo, Kim; Wang, Hui; Burnina, Irina; Choi, Byung-Kwon; Huber, Hans; Stadheim, Terrance A

    2011-01-01

    Mammalian cell culture systems are used predominantly for the production of therapeutic monoclonal antibody (mAb) products. A number of alternative platforms, such as Pichia engineered with a humanized N-linked glycosylation pathway, have recently been developed for the production of mAbs. The glycosylation profiles of mAbs produced in glycoengineered Pichia are similar to those of mAbs produced in mammalian systems. This report presents for the first time the comprehensive characterization of an anti-human epidermal growth factor receptor 2 (HER2) mAb produced in glycoengineered Pichia, and a study comparing the anti-HER2 from Pichia, which had an amino acid sequence identical to trastuzumab, with trastuzumab. The comparative study covered a full spectrum of preclinical evaluation, including bioanalytical characterization, in vitro biological functions, in vivo anti-tumor efficacy and pharmacokinetics in both mice and non-human primates. Cell signaling and proliferation assays showed that anti-HER2 from Pichia had antagonist activities comparable to trastuzumab. However, Pichia-produced material showed a 5-fold increase in binding affinity to FcγIIIA and significantly enhanced antibody dependent cell-mediated cytotoxicity (ADCC) activity, presumably due to the lack of fucose on N-glycans. In a breast cancer xenograft mouse model, anti-HER2 was comparable to trastuzumab in tumor growth inhibition. Furthermore, comparable pharmacokinetic profiles were observed for anti-HER2 and trastuzumab in both mice and cynomolgus monkeys. We conclude that glycoengineered Pichia provides an alternative production platform for therapeutic mAbs and may be of particular interest for production of antibodies for which ADCC is part of the clinical mechanism of action. PMID:21487242

  20. In vitro and in vivo studies of the combination of IGF1R inhibitor figitumumab (CP-751,871) with HER2 inhibitors trastuzumab and neratinib.

    PubMed

    Chakraborty, Ashok K; Zerillo, Cynthia; DiGiovanna, Michael P

    2015-08-01

    The insulin-like growth factor I receptor (IGF1R) has been linked to resistance to HER2-directed therapy with trastuzumab (Herceptin). We examined the anti-tumor activity of figitumumab (CP-751,871), a human monoclonal antibody that blocks IGF1R ligand binding, alone and in combination with the therapeutic anti-HER2 antibody trastuzumab and the pan-HER family tyrosine kinase inhibitor neratinib, using in vitro and in vivo breast cancer model systems. In vitro assays of proliferation, apoptosis, and signaling, and in vivo anti-tumor experiments were conducted in HER2-overexpressing (BT474) and HER2-normal (MCF7) models. We find single-agent activity of the HER2-targeting drugs but not figitumumab in the BT474 model, while the reverse is true in the MCF7 model. However, in both models, combining figitumumab with HER2-targeting drugs shows synergistic anti-proliferative and apoptosis-inducing effects, and optimum inhibition of downstream signaling. In murine xenograft models, synergistic anti-tumor effects were observed in the HER2-normal MCF7 model for the combination of figitumumab with trastuzumab, and, in the HER2-overexpressing BT474 model, enhanced anti-tumor effects were observed for the combination of figitumumab with either trastuzumab or neratinib. Analysis of tumor extracts from the in vivo experiments showed evidence of the most optimal inhibition of downstream signaling for the drug combinations over the single-agent therapies. These results suggest promise for such combinations in treating patients with breast cancer, and that, unlike the case for single-agent therapy, the therapeutic effects of such combinations may be independent of expression levels of the individual receptors or the single-agent activity profile. PMID:26195122

  1. The expanding role of pertuzumab in the treatment of HER2-positive breast cancer

    PubMed Central

    Moya-Horno, I; Cortés, J

    2015-01-01

    Breast cancer tumors that demonstrate gene amplification or overexpression of human epidermal growth factor receptor 2 (HER2) are classified as HER2-positive. They account for approximately 15% of all breast cancers and represent an adverse prognostic factor. Over the past years, many new therapies have become available for the treatment of breast cancer. Particularly, the treatment of patients with HER2-positive breast cancer has developed with the arrival of anti-HER2 targeted therapies that have been proven to increase survival in both the metastatic and early-stage settings of the disease. Trastuzumab, a monoclonal antibody targeting HER2, significantly improves survival in HER2-positive breast cancer. Nevertheless, it is still a challenge to evolve anti-HER2 therapies, as the disease may progress. Pertuzumab inhibits HER2 by binding to a different HER2 epitope than trastuzumab and represents a complementary mechanism of action to trastuzumab. The efficacy and safety of pertuzumab in combination with trastuzumab with or without chemotherapy have been demonstrated in both advanced and early stages of HER2-positive breast cancer. Herein, we review the available data on the use of pertuzumab for the treatment of patients with HER2-positive breast cancer. PMID:26056489

  2. Therapeutic strategies and mechanisms of tumorigenesis of HER2-overexpressing breast cancer.

    PubMed

    Emde, Anna; Köstler, Wolfgang J; Yarden, Yosef

    2012-12-01

    The receptor tyrosine kinase HER2 is overexpressed in approximately 25% of breast cancers. HER2 acts as a signal amplifier for its siblings, namely three different transmembrane receptors that collectively bind with 11 distinct growth factors of the EGF family. Thus, overexpression of HER2 confers aggressive invasive growth in preclinical models and in patients. Specific therapies targeting HER2 include monoclonal antibodies, antibody-drug conjugates, small molecule tyrosine kinase inhibitors, as well as heat shock protein and sheddase inhibitors. Two of these drugs have shown impressive - yet mostly transient - efficacy in patients with HER2 overexpressing breast cancer. We highlight the biological roles of HER2 in breast cancer progression, and overview the available therapeutic armamentarium directed against this receptor-kinase molecule. Focusing on the mechanisms that confer resistance to individual HER2 targeting agents, we envisage therapeutic approaches to delay or overcome the evolvement of resistance in patients. PMID:20951604

  3. Patterns of HER2 Gene Amplification and Response to Anti-HER2 Therapies

    PubMed Central

    Morancho, Beatriz; Zacarias-Fluck, Mariano; Zhang, Junjie; Martínez-Barriocanal, Águeda; Navarro Jiménez, Alexandra; Aura, Claudia; Burgues, Octavio; Lluch, Ana; Cortés, Javier; Nuciforo, Paolo; Rubio, Isabel T.; Marangoni, Elisabetta; Deeds, James; Boehm, Markus; Schlegel, Robert; Tabernero, Josep; Mosher, Rebecca; Arribas, Joaquín

    2015-01-01

    A chromosomal region that includes the gene encoding HER2, a receptor tyrosine kinase (RTK), is amplified in 20% of breast cancers. Although these tumors tend to respond to drugs directed against HER2, they frequently become resistant and resume their malignant progression. Gene amplification in double minutes (DMs), which are extrachromosomal entities whose number can be dynamically regulated, has been suggested to facilitate the acquisition of resistance to therapies targeting RTKs. Here we show that ~30% of HER2-positive tumors show amplification in DMs. However, these tumors respond to trastuzumab in a similar fashion than those with amplification of the HER2 gene within chromosomes. Furthermore, in different models of resistance to anti-HER2 therapies, the number of DMs containing HER2 is maintained, even when the acquisition of resistance is concomitant with loss of HER2 protein expression. Thus, both clinical and preclinical data show that, despite expectations, loss of HER2 protein expression due to loss of DMs containing HER2 is not a likely mechanism of resistance to anti-HER2 therapies. PMID:26075403

  4. Characteristics of HER2-positive breast cancer diagnosed following the introduction of universal HER2 testing.

    PubMed

    Pathmanathan, Nirmala; Provan, Pamela J; Mahajan, Hema; Hall, Geoffrey; Byth, Karen; Bilous, A Michael; Balleine, Rosemary L

    2012-12-01

    The aim of this study was to determine the impact of universal HER2 testing on the clinico-pathologic profile of HER2+ breast cancer. Data were extracted from breast cancer pathology reports spanning two periods: before (2003/4, n = 379), and after (2008/9, n = 560) the introduction of universal testing. In 2003/4, 43.3% of breast cancers were tested for HER2 with 16% of tested cases HER2+. In 2008/9, 98.4% of cases were tested with 14.7% HER2+. In 2008/9, HER2+ status was associated with younger age, higher grade, increased tumour size, lymph node involvement, negative oestrogen and/or progesterone receptor status. HER2+ cases diagnosed in 2003/4 were not significantly different in respect of these features. The rate of HER2+ breast cancer amongst screen detected cases in 2008/9 was 8.3%. The phenotype of HER2+ breast cancer was stable following the introduction of universal testing. The overall rate of HER2+ breast cancer was influenced by screen detection. PMID:23099207

  5. Squalamine and cisplatin block angiogenesis and growth of human ovarian cancer cells with or without HER-2 gene overexpression.

    PubMed

    Li, Dan; Williams, Jon I; Pietras, Richard J

    2002-04-25

    Angiogenesis is important for growth and progression of ovarian cancers. Squalamine is a natural antiangiogenic sterol, and its potential role in treatment of ovarian cancers with or without standard cisplatin chemotherapy was assessed. Since HER-2 gene overexpression is associated with cisplatin resistance in vitro and promotion of tumor angiogenesis in vivo, the response of ovarian cancer cells with or without HER-2 gene overexpression to squalamine and cisplatin was evaluated both in tumor xenograft models and in tissue culture. Ovarian cancer cells with or without HER-2 overexpression were grown as subcutaneous xenografts in nude mice. Animals were treated by intraperitoneal injection with control vehicle, cisplatin, squalamine or cisplatin combined with squalamine. At the end of the experiment, tumors were assessed for tumor growth inhibition and for changes in microvessel density and apoptosis. Additional in vitro studies evaluated effects of squalamine on tumor and endothelial cell growth and on signaling pathways in human endothelial cells. Profound growth inhibition was elicited by squalamine alone and by combined treatment with squalamine and cisplatin for both parental and HER-2-overexpressing ovarian tumor xenografts. Immunohistochemical evaluation of tumors revealed decreased microvessel density and increased apoptosis. Although HER-2-overexpressing tumors had more angiogenic and less apoptotic activity than parental cancers, growth of both tumor types was similarly suppressed by treatment with squalamine combined with cisplatin. In in vitro studies, we found that squalamine does not directly affect proliferation of ovarian cells. However, squalamine significantly blocked VEGF-induced activation of MAP kinase and cell proliferation in human vascular endothelial cells. The results suggest that squalamine is anti-angiogenic for ovarian cancer xenografts and appears to enhance cytotoxic effects of cisplatin chemotherapy independent of HER-2 tumor status

  6. HER2 drives Mucin-like 1 to control proliferation in breast cancer cells

    PubMed Central

    Conley, S J; Bosco, E E; Tice, D A; Hollingsworth, R E; Herbst, R; Xiao, Z

    2016-01-01

    Mucin-like 1 (MUCL1) was first identified as a breast-specific gene over a decade ago. Based on its highly restricted mRNA expression in breast tissue and continued expression during breast tumorigenesis and progression, MUCL1 is an attractive tumor-associated antigen and a potential therapeutic target. However, very little is known about the cellular location, biological functions and regulation of the MUCL1 protein, which will have a major impact on its druggability. Here we describe our efforts to fully characterize the cellular localization of MUCL1, investigate its regulation by key breast cancer oncogenes such as human epidermal growth factor receptor 2 (HER2) and discover its functional roles in breast cancer. Although some mucins are membrane bound, our data indicate that MUCL1 is secreted by some breast cancer cells, whereas others only express high levels of intracellular MUCL1. MUCL1 expression is highest in HER2-amplified breast tumors and inhibiting HER2 activity in tumor cells resulted in a decreased MUCL1 expression. In-depth investigation demonstrated that phosphoinositide3-kinase/Akt pathway, but not Ras/MEK pathway, controls MUCL1 expression downstream of HER2. Phenotypic assays revealed a strong dependence of HER2-positive cells on MUCL1 for cell proliferation. We further identified the mechanism by which MUCL1 regulates cell growth. Knockdown of MUCL1 induced a G1/S phase arrest concomitant with decreased cyclin D and increased p21 and p27 levels. Finally, we investigated the impact of MUCL1 loss on kinase signaling pathways in breast cancer cells through phospho-kinase array profiling. MUCL1 silencing abrogated phospho-focal adhesion kinase (FAK), Jun NH2-terminal kinase (JNK) and c-Jun signals, but not extracellular signal-regulated kinase or Akt pathway activities, thereby pointing to FAK/JNK pathway as the downstream effector of MUCL1 signaling. We are the first to identify an important role for MUCL1 in the proliferation of breast cancer

  7. HER2 drives Mucin-like 1 to control proliferation in breast cancer cells.

    PubMed

    Conley, S J; Bosco, E E; Tice, D A; Hollingsworth, R E; Herbst, R; Xiao, Z

    2016-08-11

    Mucin-like 1 (MUCL1) was first identified as a breast-specific gene over a decade ago. Based on its highly restricted mRNA expression in breast tissue and continued expression during breast tumorigenesis and progression, MUCL1 is an attractive tumor-associated antigen and a potential therapeutic target. However, very little is known about the cellular location, biological functions and regulation of the MUCL1 protein, which will have a major impact on its druggability. Here we describe our efforts to fully characterize the cellular localization of MUCL1, investigate its regulation by key breast cancer oncogenes such as human epidermal growth factor receptor 2 (HER2) and discover its functional roles in breast cancer. Although some mucins are membrane bound, our data indicate that MUCL1 is secreted by some breast cancer cells, whereas others only express high levels of intracellular MUCL1. MUCL1 expression is highest in HER2-amplified breast tumors and inhibiting HER2 activity in tumor cells resulted in a decreased MUCL1 expression. In-depth investigation demonstrated that phosphoinositide3-kinase/Akt pathway, but not Ras/MEK pathway, controls MUCL1 expression downstream of HER2. Phenotypic assays revealed a strong dependence of HER2-positive cells on MUCL1 for cell proliferation. We further identified the mechanism by which MUCL1 regulates cell growth. Knockdown of MUCL1 induced a G1/S phase arrest concomitant with decreased cyclin D and increased p21 and p27 levels. Finally, we investigated the impact of MUCL1 loss on kinase signaling pathways in breast cancer cells through phospho-kinase array profiling. MUCL1 silencing abrogated phospho-focal adhesion kinase (FAK), Jun NH2-terminal kinase (JNK) and c-Jun signals, but not extracellular signal-regulated kinase or Akt pathway activities, thereby pointing to FAK/JNK pathway as the downstream effector of MUCL1 signaling. We are the first to identify an important role for MUCL1 in the proliferation of breast cancer

  8. Molecular Features and Survival Outcomes of the Intrinsic Subtypes Within HER2-Positive Breast Cancer

    PubMed Central

    Carey, Lisa A.; Adamo, Barbara; Vidal, Maria; Tabernero, Josep; Cortés, Javier; Parker, Joel S.; Perou, Charles M.; Baselga, José

    2014-01-01

    Background The clinical impact of the biological heterogeneity within HER2-positive (HER2+) breast cancer is not fully understood. Here, we evaluated the molecular features and survival outcomes of the intrinsic subtypes within HER2+ breast cancer. Methods We interrogated The Cancer Genome Atlas (n = 495) and Molecular Taxonomy of Breast Cancer International Consortium (METABRIC) datasets (n = 1730) of primary breast cancers for molecular data derived from DNA, RNA and protein, and determined intrinsic subtype. Clinical HER2 status was defined according to American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) guidelines or DNA copy-number aberration by single nucleotide polymorphism arrays. Cox models tested the prognostic significance of each variable in patients not treated with trastuzumab (n = 1711). Results Compared with clinically HER2 (cHER2)-negative breast cancer, cHER2+ breast cancer had a higher frequency of the HER2-enriched (HER2E) subtype (47.0% vs 7.1%) and a lower frequency of Luminal A (10.7% vs 39.0%) and Basal-like (14.1% vs 23.4%) subtypes. The likelihood of cHER2-positivity in HER2E, Luminal B, Basal-like and Luminal A subtypes was 64.6%, 20.0%, 14.4% and 7.3%, respectively. Within each subtype, only 0.3% to 3.9% of genes were found differentially expressed between cHER2+ and cHER2-negative tumors. Within cHER2+ tumors, HER2 gene and protein expression was statistically significantly higher in the HER2E and Basal-like subtypes than either luminal subtype. Neither cHER2 status nor the new 10-subtype copy number-based classification system (IntClust) added independent prognostic value to intrinsic subtype. Conclusions When the intrinsic subtypes are taken into account, cHER2-positivity does not translate into large changes in the expression of downstream signaling pathways, nor does it affect patient survival in the absence of HER2 targeting. PMID:25139534

  9. Human Epidermal Growth Factor Receptor 2 (HER2) –Specific Chimeric Antigen Receptor–Modified T Cells for the Immunotherapy of HER2-Positive Sarcoma

    PubMed Central

    Ahmed, Nabil; Brawley, Vita S.; Hegde, Meenakshi; Robertson, Catherine; Ghazi, Alexia; Gerken, Claudia; Liu, Enli; Dakhova, Olga; Ashoori, Aidin; Corder, Amanda; Gray, Tara; Wu, Meng-Fen; Liu, Hao; Hicks, John; Rainusso, Nino; Dotti, Gianpietro; Mei, Zhuyong; Grilley, Bambi; Gee, Adrian; Rooney, Cliona M.; Brenner, Malcolm K.; Heslop, Helen E.; Wels, Winfried S.; Wang, Lisa L.; Anderson, Peter; Gottschalk, Stephen

    2015-01-01

    Purpose The outcome for patients with metastatic or recurrent sarcoma remains poor. Adoptive therapy with tumor-directed T cells is an attractive therapeutic option but has never been evaluated in sarcoma. Patients and Methods We conducted a phase I/II clinical study in which patients with recurrent/refractory human epidermal growth factor receptor 2 (HER2) –positive sarcoma received escalating doses (1 × 104/m2 to 1 × 108/m2) of T cells expressing an HER2-specific chimeric antigen receptor with a CD28.ζ signaling domain (HER2-CAR T cells). Results We enrolled 19 patients with HER2-positive tumors (16 osteosarcomas, one Ewing sarcoma, one primitive neuroectodermal tumor, and one desmoplastic small round cell tumor). HER2-CAR T-cell infusions were well tolerated with no dose-limiting toxicity. At dose level 3 (1 × 105/m2) and above, we detected HER2-CAR T cells 3 hours after infusion by quantitative polymerase chain reaction in 14 of 16 patients. HER2-CAR T cells persisted for at least 6 weeks in seven of the nine evaluable patients who received greater than 1 × 106/m2 HER2-CAR T cells (P = .005). HER2-CAR T cells were detected at tumor sites of two of two patients examined. Of 17 evaluable patients, four had stable disease for 12 weeks to 14 months. Three of these patients had their tumor removed, with one showing ≥ 90% necrosis. The median overall survival of all 19 infused patients was 10.3 months (range, 5.1 to 29.1 months). Conclusion This first evaluation of the safety and efficacy of HER2-CAR T cells in patients with cancer shows the cells can persist for 6 weeks without evident toxicities, setting the stage for studies that combine HER2-CAR T cells with other immunomodulatory approaches to enhance their expansion and persistence. PMID:25800760

  10. HER2 intratumoral heterogeneity analyses by concurrent HER2 gene and protein assessment for the prognosis of HER2 negative invasive breast cancer patients.

    PubMed

    Kurozumi, Sasagu; Padilla, Mary; Kurosumi, Masafumi; Matsumoto, Hiroshi; Inoue, Kenichi; Horiguchi, Jun; Takeyoshi, Izumi; Oyama, Tetsunari; Ranger-Moore, Jim; Allred, D Craig; Dennis, Eslie; Nitta, Hiroaki

    2016-07-01

    HER2 gene-protein assay (GPA) is a new method for the simultaneous evaluation of HER2 immunohistochemistry (IHC) and HER2 dual in situ hybridization (DISH) on single tissue sections of breast cancer. We investigated the presence of HER2 gene and protein discrepancy and HER2-heterogeneity using HER2-GPA. HER2 status was analyzed for the correlation between the presence of HER2-heterogeneity and patient prognosis. Consecutive 280 invasive breast cancer were examined. Statuses of HER2 protein and gene were evaluated in whole tumor sections of HER2 GPA slides. HER2 protein and gene combination patterns were classified to six phenotypic and genotypic types for each case, as well as at individual cell levels: (A) IHC and DISH positive; (B) IHC positive and DISH negative; (C) IHC equivocal and DISH positive; (D) IHC equivocal and DISH negative; (E) IHC negative and DISH positive; and (F) IHC and DISH negative. The presence of HER2-heterogeneity was determined by the existence of at least two of six types within one tumor. HER2-IHC positive patients had significantly worse survival than IHC negative patients and HER2-DISH positive patients had significantly worse survival than DISH negative patients. HER2 IHC negative and DISH positive patients had significantly worse recurrence-free survival than IHC and DISH negative patients. In the HER2 IHC and DISH negative group, the HER2 heterogeneous group had significantly worse survival than the nonheterogeneous group. Notably, among triple negative breast cancer (TNBC), the HER2 heterogeneous group had significantly worse survival than the nonheterogeneous group. Our study suggests that the presence of HER2-heterogeneity might be a prognostic factor in HER2 negative breast cancer patients, especially in TNBC. PMID:27318853

  11. Pten loss promotes MAPK pathway dependency in HER2/neu breast carcinomas.

    PubMed

    Ebbesen, Saya H; Scaltriti, Maurizio; Bialucha, Carl U; Morse, Natasha; Kastenhuber, Edward R; Wen, Hannah Y; Dow, Lukas E; Baselga, José; Lowe, Scott W

    2016-03-15

    Loss of the tumor suppressor gene PTEN is implicated in breast cancer progression and resistance to targeted therapies, and is thought to promote tumorigenesis by activating PI3K signaling. In a transgenic model of breast cancer, Pten suppression using a tetracycline-regulatable short hairpin (sh)RNA cooperates with human epidermal growth factor receptor 2 (HER2/neu), leading to aggressive and metastatic disease with elevated signaling through PI3K and, surprisingly, the mitogen-activated protein kinase (MAPK) pathway. Restoring Pten function is sufficient to down-regulate both PI3K and MAPK signaling and triggers dramatic tumor regression. Pharmacologic inhibition of MAPK signaling produces similar effects to Pten restoration, suggesting that the MAPK pathway contributes to the maintenance of advanced breast cancers harboring Pten loss. PMID:26929372

  12. Pten loss promotes MAPK pathway dependency in HER2/neu breast carcinomas

    PubMed Central

    Ebbesen, Saya H.; Scaltriti, Maurizio; Bialucha, Carl U.; Morse, Natasha; Kastenhuber, Edward R.; Wen, Hannah Y.; Dow, Lukas E.; Baselga, José; Lowe, Scott W.

    2016-01-01

    Loss of the tumor suppressor gene PTEN is implicated in breast cancer progression and resistance to targeted therapies, and is thought to promote tumorigenesis by activating PI3K signaling. In a transgenic model of breast cancer, Pten suppression using a tetracycline-regulatable short hairpin (sh)RNA cooperates with human epidermal growth factor receptor 2 (HER2/neu), leading to aggressive and metastatic disease with elevated signaling through PI3K and, surprisingly, the mitogen-activated protein kinase (MAPK) pathway. Restoring Pten function is sufficient to down-regulate both PI3K and MAPK signaling and triggers dramatic tumor regression. Pharmacologic inhibition of MAPK signaling produces similar effects to Pten restoration, suggesting that the MAPK pathway contributes to the maintenance of advanced breast cancers harboring Pten loss. PMID:26929372

  13. Activating HER2 mutations in HER2 gene amplification negative breast cancer

    PubMed Central

    Bose, Ron; Kavuri, Shyam M.; Searleman, Adam C.; Shen, Wei; Shen, Dong; Koboldt, Daniel C.; Monsey, John; Goel, Nicholas; Aronson, Adam B.; Li, Shunqiang; Ma, Cynthia X.; Ding, Li; Mardis, Elaine R.; Ellis, Matthew J.

    2012-01-01

    Data from eight breast cancer genome sequencing projects identified 25 patients with HER2 somatic mutations in cancers lacking HER2 gene amplification. To determine the phenotype of these mutations, we functionally characterized thirteen HER2 mutations using in vitro kinase assays, protein structure analysis, cell culture and xenograft experiments. Seven of these mutations are activating mutations, including G309A, D769H, D769Y, V777L, P780ins, V842I, and R896C. HER2 in-frame deletion 755-759, which is homologous to EGFR exon 19 in-frame deletions, had a neomorphic phenotype with increased phosphorylation of EGFR or HER3. L755S produced lapatinib resistance, but was not an activating mutation in our experimental systems. All of these mutations were sensitive to the irreversible kinase inhibitor, neratinib. These findings demonstrate that HER2 somatic mutation is an alternative mechanism to activate HER2 in breast cancer and they validate HER2 somatic mutations as drug targets for breast cancer treatment. PMID:23220880

  14. Dual HER2 blockade in the neoadjuvant and adjuvant treatment of HER2-positive breast cancer

    PubMed Central

    Advani, Pooja; Cornell, Lauren; Chumsri, Saranya; Moreno-Aspitia, Alvaro

    2015-01-01

    Human epidermal growth factor receptor 2 (HER2) is a tyrosine kinase transmembrane receptor that is overexpressed on the surface of 15%–20% of breast tumors and has been associated with poor prognosis. Consistently improved pathologic response and survival rates have been demonstrated with use of trastuzumab in combination with standard chemotherapy in both early and advanced breast cancer. However, resistance to trastuzumab may pose a major problem in the effective treatment of HER2-positive breast cancer. Dual HER2 blockade, using agents that work in a complimentary fashion to trastuzumab, has more recently been explored to evade resistance in both the preoperative (neoadjuvant) and adjuvant settings. Increased effectiveness of dual anti-HER2 agents over single blockade has been recently reported in clinical studies. Pertuzumab in combination with trastuzumab and taxane is currently approved in the metastatic and neoadjuvant treatment of HER2-positive breast cancer. Various biomarkers have also been investigated to identify subsets of patients with HER2-positive tumors who would likely respond best to these targeted therapy combinations. In this article, available trial data regarding efficacy and toxicity of treatment with combination HER2 agents in the neoadjuvant and adjuvant setting have been reviewed, and relevant correlative biomarker data from these trials have been discussed. PMID:26451122

  15. Parsing ERK Activation Reveals Quantitatively Equivalent Contributions From Epidermal Growth Factor Receptor and HER2 In Human Mammary Epithelial Cells

    SciTech Connect

    Hendriks, Bart S.; Orr, Galya; Wells, Alan H.; Wiley, H. S.; Lauffenburger, Douglas A.

    2005-02-18

    HER2, a member of the EGFR tyrosine kinase family, functions as an accessory EGFR signaling component and alters EGFR trafficking by heterodimerization. HER2 overexpression leads to aberrant cell behavior including enhanced proliferation and motility. Here we apply a combination of computational modeling and quantitative experimental studies of the dynamic interactions between EGFR and HER2, and their downstream activation of extracellular signal-related kinase (ERK) to understand this complex signaling system. Using cells expressing different levels of HER2 relative to the EGFR, we can separate relative contributions of EGFR and HER2 to signaling amplitude and duration. Based on our model calculations, we demonstrate that, in contrast with previous suggestions in the literature, the intrinsic capabilities of EGFR and HER2 to activated ERK are quantitatively equivalent . We find that HER2-mediated effects on EGFR dimerization and trafficking are sufficient to explain the detected HER2-mediated amplification of EGF-induced ERK signaling. Our model suggests that transient amplification of ERK activity by HER2 arises predominantly from the 2-to-1 stoichiometry of receptor kinase to bound ligand in EGFR/HER2 heterodimers compared to the 1-to-1 stoichiometry of the EGFR homodimer, but alterations in receptor trafficking, with resultant EGFR sparing, cause the sustained HER2-mediated enhancement of ERK signaling.

  16. Therapeutic siRNA for drug-resistant HER2-positive breast cancer

    PubMed Central

    Ngamcherdtrakul, Worapol; Castro, David J.; Morry, Jingga; Reda, Moataz M.; Gray, Joe W.; Yantasee, Wassana

    2016-01-01

    HER2 is overexpressed in about 20% of breast cancers and contributes to poor prognosis. Unfortunately, a large fraction of patients have primary or acquired resistance to the HER2-targeted therapy trastuzumab, thus a multi-drug combination is utilized in the clinic, putting significant burden on patients. We systematically identified an optimal HER2 siRNA from 76 potential sequences and demonstrated its utility in overcoming intrinsic and acquired resistance to trastuzumab and lapatinib in 18 HER2-positive cancer cell lines. We provided evidence that the drug-resistant cancer maintains dependence on HER2 for survival. Importantly, cell lines did not readily develop resistance following extended treatment with HER2 siRNA. Using our recently developed nanoparticle platform, systemic delivery of HER2 siRNA to trastuzumab-resistant tumors resulted in significant growth inhibition. Moreover, the optimal HER2 siRNA could also silence an exon 16 skipped HER2 splice variant reported to be highly oncogenic and linked to trastuzumab resistance. PMID:26894975

  17. HER2 immunohistochemistry significantly overestimates HER2 amplification in uterine papillary serous carcinomas.

    PubMed

    Mentrikoski, Mark J; Stoler, Mark H

    2014-06-01

    Recently, there have been numerous reports showing that HER2 overexpression or amplification occurs in a variable number of uterine papillary serous carcinoma (UPSC) cases, leading to a current clinical trial targeting this pathway. Although approved algorithms exist for scoring HER2 overexpression/amplification in breast and gastroesophageal carcinomas, scoring criteria and the optimal methodology for assessing HER2 in UPSC are currently unknown. Most frequently, the American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP) breast carcinoma algorithms have been utilized for UPSC, wherein cases are screened with immunohistochemistry (IHC), followed by fluorescence in situ hybridization for equivocal cases. However, interpreting HER2 IHC can be prone to significant subjectivity, often leading to false-positive results. To better correlate HER2 IHC results with underlying amplification in UPSC, we compared HER2 overexpression by IHC with HER2 amplification with chromogenic in situ hybridization (CISH). A total of 69 cases of UPSC-57 pure and 12 mixed-were identified over a 10-year period. All were included in a tissue microarray, and HER2 IHC and CISH were performed. Each case was scored according to the most recent 2013, as well as the 2007, ASCO/CAP scoring guidelines for breast carcinoma. Whole-tissue sections were also examined in cases with amplification by CISH on initial screening, as well as an equal number of negative cases, to account for intratumoral heterogeneity. Nine (13%) cases showed HER2 amplification by CISH, whereas 14 (20%) and 28 (40%) cases showed overexpression with IHC when the 2007 or 2013 ASCO/CAP criteria were utilized, respectively. The overall concordance rate between CISH and IHC was 64% (9/14) with the 2007 ASCO/CAP criteria and 32% (9/28) with the 2013 ASCO/CAP criteria. Intratumoral heterogeneity was seen in 3 (33%) amplified cases. No additional amplified cases were identified on subsequent whole

  18. Switching addictions between HER2 and FGFR2 in HER2-positive breast tumor cells: FGFR2 as a potential target for salvage after lapatinib failure

    SciTech Connect

    Azuma, Koichi; Tsurutani, Junji; Sakai, Kazuko; Kaneda, Hiroyasu; Fujisaka, Yasuhito; Takeda, Masayuki; Watatani, Masahiro; Arao, Tokuzo; Satoh, Taroh; Okamoto, Isamu; Kurata, Takayasu; Nishio, Kazuto; Nakagawa, Kazuhiko

    2011-04-01

    Highlights: {yields} A lapatinib-resistant breast cancer cell line, UACC812 (UACC812/LR), was found to harbor amplification of the FGFR2 gene. {yields} Inhibition of the molecule by a specific inhibitor of FGFR dramatically induced growth inhibition accompanied by cell death. {yields} Immunohistochemical analysis of patients with HER2-positive breast cancer demonstrated an association between FGFR2 expression and poor outcome for lapatinib-containing chemotherapy. -- Abstract: Agents that target HER2 have improved the prognosis of patients with HER2-amplified breast cancers. However, patients who initially respond to such targeted therapy eventually develop resistance to the treatment. We have established a line of lapatinib-resistant breast cancer cells (UACC812/LR) by chronic exposure of HER2-amplified and lapatinib-sensitive UACC812 cells to the drug. The mechanism by which UACC812/LR acquired resistance to lapatinib was explored using comprehensive gene hybridization. The FGFR2 gene in UACC812/LR was highly amplified, accompanied by overexpression of FGFR2 and reduced expression of HER2, and a cell proliferation assay showed that the IC{sub 50} of PD173074, a small-molecule inhibitor of FGFR tyrosine kinase, was 10,000 times lower in UACC812/LR than in the parent cells. PD173074 decreased the phosphorylation of FGFR2 and substantially induced apoptosis in UACC812/LR, but not in the parent cells. FGFR2 appeared to be a pivotal molecule for the survival of UACC812/LR as they became independent of the HER2 pathway, suggesting that a switch of addiction from the HER2 to the FGFR2 pathway enabled cancer cells to become resistant to HER2-targeted therapy. The present study is the first to implicate FGFR in the development of resistance to lapatinib in cancer, and suggests that FGFR-targeted therapy might become a promising salvage strategy after lapatinib failure in patients with HER2-positive breast cancer.

  19. Assessment of HER2 amplification status in breast cancer using a new automated HER2 IQFISH pharmDx™ (Dako Omnis) assay.

    PubMed

    Viale, Giuseppe; Paterson, Jennifer; Bloch, Miriam; Csathy, George; Allen, David; Dell'Orto, Patrizia; Kjærsgaard, Gitte; Levy, Yaron Y; Jørgensen, Jan Trøst

    2016-08-01

    In breast cancer the human epidermal growth factor receptor 2 (HER2) is an important target for a number of different HER2 inhibitors. Different slide-based assays are available for assessment of treatment eligibility, which include fluorescence in situ hybridization (FISH) or other in situ hybridization (ISH) methods for assessment of the HER2 gene status. Here we report a summary of the validation data on HER2 IQFISH pharmDx™ (Dako Omnis), a newly developed assay for the automated staining platform Dako Omnis. The assay uses a non-toxic buffer that significantly reduces the hybridization time, which results in a total turnaround time of 3½ to 4h from deparaffinization to counting of the gene and centromere signals. The data reported in the current summary covers method comparison, assessment of staining quality, observer-to-observer reproducibility as well as reproducibility within and between laboratories. Based on data from the different studies it was concluded that HER2 IQFISH pharmDx (Dako Omnis) is a reliable and robust assay with a high precision that is at least comparable to the manual HER2 IQFISH pharmDx™ assay and the PathVysion(®)HER-2 DNA Probe Kit. PMID:27461826

  20. Lipid-conjugated telomerase template antagonists sensitize resistant HER2-positive breast cancer cells to trastuzumab.

    PubMed

    Goldblatt, Erin M; Erickson, Priscilla A; Gentry, Erin R; Gryaznov, Sergei M; Herbert, Brittney-Shea

    2009-11-01

    HER2 amplification in breast cancer is associated with a more aggressive disease, greater likelihood of recurrence, and decreased survival compared to women with HER2-negative breast cancer. Trastuzumab is a monoclonal antibody that inhibits HER2 activity, making this compound an important therapeutic option for patients with HER2-positive breast cancer. However, resistance to trastuzumab develops rapidly in a large number of breast cancer patients. The objective of this study was to determine whether GRN163L, a telomerase template antagonist currently in clinical trials for cancer treatment, can augment the effects of trastuzumab in breast cancer cells with HER2 amplification. GRN163L was effective in inhibiting telomerase activity and shortening telomeres in HER2-positive breast cancer cells. We show that GRN163L acts synergistically with trastuzumab in inhibiting HER2-positive breast cancer cell growth. More importantly, we show that GRN163L can restore the sensitivity of therapeutic-resistant breast cancer cells to trastuzumab. These findings implicate that telomerase template antagonists have potential use in the treatment of cancers that have developed resistance to traditional cancer therapy. PMID:18853252

  1. Combined effects of lapatinib and bortezomib in human epidermal receptor 2 (HER2)-overexpressing breast cancer cells and activity of bortezomib against lapatinib-resistant breast cancer cells.

    PubMed

    Ma, Chuandong; Niu, Xiuqing; Luo, Jianmin; Shao, Zhimin; Shen, Kunwei

    2010-10-01

    Lapatinib and bortezomib are highly active against breast cancer cells. Breast cancer patients who initially respond to lapatinib may eventually manifest acquired resistance to this treatment. Thus, the identification of novel agents that may prevent or delay the development of acquired resistance to lapatinib is critical. In the current study, we show that the combination of lapatinib and bortezomib results in a synergistic growth inhibition in human epidermal receptor 2 (HER2)-overexpressing breast cancer cells and that the combination enhances apoptosis of SK-BR-3 cells. Importantly, we found that the combination of lapatinib plus bortezomib more effectively blocked activation of the HER2 pathway in SK-BR-3 cells, compared with monotherapy. In addition, we established a model of acquired resistance to lapatinib by chronically challenging SK-BR-3 breast cancer cells with increasing concentrations of lapatinib. Here, we showed that bortezomib notably induced apoptosis of lapatinib-resistant SK-BR-3 pools and further inhibited HER2 signaling in the resistant cells. Taken together, the current data indicate a synergistic interaction between lapatinib and bortezomib in HER2-overexpressing breast cancer cells and provide the rationale for the clinical evaluation of these two noncross-resistant targeted therapies. The combination of lapatinib and bortezomib may be a potentially novel approach to prevent or delay the onset of acquired resistance to lapatinib in HER2-overxpressing/estrogen receptor (ER)-negative breast cancers. PMID:20701607

  2. Post-Stop-Signal Adjustments: Inhibition Improves Subsequent Inhibition

    ERIC Educational Resources Information Center

    Bissett, Patrick G.; Logan, Gordon D.

    2012-01-01

    Performance in the stop-signal paradigm involves a balance between going and stopping, and one way that this balance is struck is through shifting priority away from the go task, slowing responses after a stop signal, and improving the probability of inhibition. In 6 experiments, the authors tested whether there is a corresponding shift in…

  3. Outcomes of chemotherapies and HER2 directed therapies in advanced HER2-mutant lung cancers.

    PubMed

    Eng, Juliana; Hsu, Meier; Chaft, Jamie E; Kris, Mark G; Arcila, Maria E; Li, Bob T

    2016-09-01

    Human epidermal growth factor receptor 2 (HER2, ERBB2) mutations occur in 3% of lung adenocarcinomas. While case reports and series have shown activity of HER2 targeted agents in these patients, little is known about outcomes of chemotherapies. Patients with stage IV HER2-mutant lung cancers at Memorial Sloan Kettering were reviewed. Patient demographics, types of HER2 mutations, duration of systemic treatments and survival were analyzed. We identified 38 patients with HER2-mutant lung cancers: median age 62; majority were women (n=24), never smokers (n=22), and all had adenocarcinomas. A 12 base pair in-frame insertion YVMA in exon 20 (p.A775_G776insYVMA) was present in 24 (63%, 95% CI 46-78%) patients. In addition, there were four 9 base pair insertions, one 6 base pair insertion, and five 3 base pair insertions in exon 20, and four single bp substitutions (exon 20 L755F, V777L, D769H, exon 8 S310F). The median overall survival from date of diagnosis of stage IV disease was 2.3 years (95% CI 1.2-2.6). The median duration of chemotherapy was 4.3 months (68 treatments, range 0-21 months): 6.2 months for pemetrexed ±platinum/bevacizumab, 4 months for taxane ±platinum/bevacizumab, 2.6 months for gemcitabine, 3.5 months for vinorelbine. The median duration of HER2 tyrosine kinase inhibitors was 2.2 months (28 treatments, range 0.3-16.3 months). As we search for better targeted therapies for patients with HER2-mutant lung cancers, chemotherapy remains an important component of care. PMID:27565914

  4. A gene-protein assay for human epidermal growth factor receptor 2 (HER2): brightfield tricolor visualization of HER2 protein, the HER2 gene, and chromosome 17 centromere (CEN17) in formalin-fixed, paraffin-embedded breast cancer tissue sections

    PubMed Central

    2012-01-01

    Background The eligibility of breast cancer patients for human epidermal growth factor receptor 2 (HER2)-directed therapies is determined by the HER2 gene amplification and/or HER2 protein overexpression status of the breast tumor as determined by in situ hybridization (ISH) or immunohistochemistry (IHC), respectively. Our objective was to combine the US Food and Drug Administration (FDA)-approved HER2 & chromosome 17 centromere (CEN17) brightfield ISH (BISH) and HER2 IHC assays into a single automated HER2 gene-protein assay allowing simultaneous detection of all three targets in a single tissue section. Methods The HER2 gene-protein assay was optimized using formalin-fixed, paraffin-embedded (FFPE) samples of the xenograft tumors MCF7 [HER2 negative (non-amplified gene, protein negative)] and Calu-3 [HER2 positive (amplified gene, protein positive)]. HER2 IHC was performed using a rabbit monoclonal anti-HER2 antibody (clone 4B5) and a conventional 3,3'-diaminobenzidine IHC detection. The HER2 & CEN17 BISH signals were visualized using horseradish peroxidase-based silver and alkaline phosphatase-based red detection systems, respectively with a cocktail of 2,4-dinitrophenyl-labeled HER2 and digoxigenin-labeled CEN17 probes. The performance of the gene-protein assay on tissue microarray slides containing 189 randomly selected FFPE clinical breast cancer tissue cores was compared to that of the separate HER2 IHC and HER2 & CEN17 BISH assays. Results HER2 protein detection was optimal when the HER2 IHC protocol was used before (rather than after) the BISH protocol. The sequential use of HER2 IHC and HER2 & CEN17 BISH detection steps on FFPE xenograft tumor sections appropriately co-localized the HER2 protein, HER2 gene, and CEN17 signals after mitigating the silver background staining by using a naphthol phosphate-containing hybridization buffer for the hybridization step. The HER2 protein and HER2 gene status obtained using the multiplex HER2 gene-protein assay

  5. Cationic Polymer Modified Mesoporous Silica Nanoparticles for Targeted SiRNA Delivery to HER2+ Breast Cancer

    PubMed Central

    Ngamcherdtrakul, Worapol; Morry, Jingga; Gu, Shenda; Castro, David J.; Goodyear, Shaun M.; Sangvanich, Thanapon; Reda, Moataz M.; Lee, Richard; Mihelic, Samuel A.; Beckman, Brandon L.; Hu, Zhi; Gray, Joe W.; Yantasee, Wassana

    2015-01-01

    In vivo delivery of siRNAs designed to inhibit genes important in cancer and other diseases continues to be an important biomedical goal. We now describe a new nanoparticle construct that has been engineered for efficient delivery of siRNA to tumors. The construct is comprised of a 47-nm mesoporous silica nanoparticle (MSNP) core coated with a cross-linked PEI-PEG copolymer, carrying siRNA against the HER2 oncogene, and coupled to the anti-HER2 monoclonal antibody (trastuzumab). The construct has been engineered to increase siRNA blood half-life, enhance tumor-specific cellular uptake, and maximize siRNA knockdown efficacy. The optimized anti-HER2-nanoparticles produced apoptotic death in HER2 positive (HER2+) breast cancer cells grown in vitro, but not in HER2 negative (HER2−) cells. One dose of the siHER2-nanoparticles reduced HER2 protein levels by 60% in trastuzumab-resistant HCC1954 xenografts. Multiple doses administered intravenously over 3 weeks significantly inhibited tumor growth (p < 0.004). The siHER2-nanoparticles have an excellent safety profile in terms of blood compatibility and low cytokine induction, when exposed to human peripheral blood mononuclear cells. The construct can be produced with high batch-to-batch reproducibility and the production methods are suitable for large-scale production. These results suggest that this siHER2-nanoparticle is ready for clinical evaluation. PMID:26097445

  6. In a cohort of breast cancer screened patients the proportion of HER2 positive cases is lower than that earlier reported and pathological characteristics differ between HER2 3+ and HER2 2+/Her2 amplified cases.

    PubMed

    Giuliani, Silvia; Ciniselli, Chiara Maura; Leonardi, Elena; Polla, Enzo; Decarli, Nicola; Luchini, Claudio; Cantaloni, Chiara; Gasperetti, Fabio; Cazzolli, Daniela; Berlanda, Gabriella; Bernardi, Daniela; Pellegrini, Marco; Triolo, Renza; Ferro, Antonella; Verderio, Paolo; Barbareschi, Mattia

    2016-07-01

    Human epithelial growth factor receptor 2 (HER2) overexpression and/or amplification is of predictive and prognostic value in infiltrating breast carcinoma (IBC). We evaluated the proportion of HER2-positive cases (score 3 overexpression/score 2 plus fluorescence in situ hybridization (FISH) amplification) in a consecutive series of 2163 patients. According to immunohistochemical analysis of HER2 expression, using Herceptest and FDA criteria, 839 cases had score 0, 476 score 1+, 699 score 2+, and 149 score 3+. Of the 699 scoring 2+ cases, 160 (22.88 %) showed Her2 gene amplification by FISH analysis, making a total of 309 (14.28 %) HER2-positive cases. Grade 1 ductal and special type IBC were never HER2 positive, while only three infiltrating lobular carcinomas but a relevant percentage of small IBC were HER2 positive. Of HER2-positive cases, 52.1 % was pT1 and of these, 38.5 % was pT1b or smaller. Logistic regression analysis revealed that estrogen receptor (ER), progesterone receptor (PgR), grade, and pT were significantly associated with HER2 positivity and that HER2 3+ cases were more frequently of higher grade and pT than HER2 2+/Her2 amplified cases. In addition, HER2 3+ cases were more frequently in ER and PgR negative than HER2 2+/Her2 amplified cases. We conclude that the proportion of HER2 positive cases is lower than that reported in older literature and that pathological characteristics differ between HER2 3+ and HER2 2+/Her2 amplified cases. PMID:27097809

  7. A FcγRIII-engaging bispecific antibody expands the range of HER2-expressing breast tumors eligible to antibody therapy.

    PubMed

    Turini, Marc; Chames, Patrick; Bruhns, Pierre; Baty, Daniel; Kerfelec, Brigitte

    2014-07-30

    Trastuzumab is established as treatment of HER2high metastatic breast cancers but many limitations impair its efficacy. Here, we report the design of a Fab-like bispecific antibody (HER2bsFab) that displays a moderate affinity for HER2 and a unique, specific and high affinity for FcγRIII. In vitro characterization showed that ADCC was the major mechanism of action of HER2bsFab as no significant HER2-driven effect was observed. HER2bsFab mediated ADCC at picomolar concentration against HER2high, HER2low as well as trastuzumab-refractive cell lines. In vivo HER2bsFab potently inhibited HER2high tumor growth by recruitment of mouse FcγRIII and IV-positive resident effector cells and more importantly, exhibited a net superiority over trastuzumab at inhibiting HER2low tumor growth. Moreover, FcγRIIIA-engagement by HER2bsFab was independent of V/F158 polymorphism and induced a stronger NK cells activation in response to target cell recognition. Thus, taking advantage of its epitope specificity and affinity for HER2 and FcγRIIIA, HER2bsFab exhibits potent anti-tumor activity against HER2low tumors while evading most of trastuzumab Fc-linked limitations thereby potentially enlarging the number of patients eligible for breast cancer immunotherapy. PMID:24979648

  8. A FcγRIII-engaging bispecific antibody expands the range of HER2-expressing breast tumors eligible to antibody therapy

    PubMed Central

    Turini, Marc; Chames, Patrick; Bruhns, Pierre

    2014-01-01

    Trastuzumab is established as treatment of HER2high metastatic breast cancers but many limitations impair its efficacy. Here, we report the design of a Fab-like bispecific antibody (HER2bsFab) that displays a moderate affinity for HER2 and a unique, specific and high affinity for FcγRIII. In vitro characterization showed that ADCC was the major mechanism of action of HER2bsFab as no significant HER2-driven effect was observed. HER2bsFab mediated ADCC at picomolar concentration against HER2high, HER2low as well as trastuzumab-refractive cell lines. In vivo HER2bsFab potently inhibited HER2high tumor growth by recruitment of mouse FcγRIII and IV-positive resident effector cells and more importantly, exhibited a net superiority over trastuzumab at inhibiting HER2low tumor growth. Moreover, FcγRIIIA-engagement by HER2bsFab was independent of V/F158 polymorphism and induced a stronger NK cells activation in response to target cell recognition. Thus, taking advantage of its epitope specificity and affinity for HER2 and FcγRIIIA, HER2bsFab exhibits potent anti-tumor activity against HER2low tumors while evading most of trastuzumab Fc-linked limitations thereby potentially enlarging the number of patients eligible for breast cancer immunotherapy. PMID:24979648

  9. Modeling invasive breast cancer: growth factors propel progression of HER2-positive premalignant lesions

    PubMed Central

    Pradeep, C-R; Zeisel, A; Köstler, WJ; Lauriola, M; Jacob-Hirsch, J; Haibe-Kains, B; Amariglio, N; Ben-Chetrit, N; Emde, A; Solomonov, I; Neufeld, G; Piccart, M; Sagi, I; Sotiriou, C; Rechavi, G; Domany, E; Desmedt, C; Yarden, Y

    2013-01-01

    The HER2/neu oncogene encodes a receptor-like tyrosine kinase whose overexpression in breast cancer predicts poor prognosis and resistance to conventional therapies. However, the mechanisms underlying aggressiveness of HER2 (human epidermal growth factor receptor 2)-overexpressing tumors remain incompletely understood. Because it assists epidermal growth factor (EGF) and neuregulin receptors, we overexpressed HER2 in MCF10A mammary cells and applied growth factors. HER2-overexpressing cells grown in extracellular matrix formed filled spheroids, which protruded outgrowths upon growth factor stimulation. Our transcriptome analyses imply a two-hit model for invasive growth: HER2-induced proliferation and evasion from anoikis generate filled structures, which are morphologically and transcriptionally analogous to preinvasive patients’ lesions. In the second hit, EGF escalates signaling and transcriptional responses leading to invasive growth. Consistent with clinical relevance, a gene expression signature based on the HER2/EGF-activated transcriptional program can predict poorer prognosis of a subgroup of HER2-overexpressing patients. In conclusion, the integration of a three-dimensional cellular model and clinical data attributes progression of HER2-overexpressing lesions to EGF-like growth factors acting in the context of the tumor's microenvironment. PMID:22139081

  10. Beyond trastuzumab: small molecule tyrosine kinase inhibitors in HER-2-positive breast cancer.

    PubMed

    Roy, Vivek; Perez, Edith A

    2009-11-01

    HER-2 is a transmembrane, tyrosine kinase (TK) receptor whose overexpression is associated with adverse prognosis in breast cancer. The biological effects of HER-2 are mediated by kinase activity causing phosphorylation of tyrosine residues in the cytoplasmic domain of the receptor molecule, leading to activation of downstream growth-promoting pathways. Antibody-mediated inhibition by trastuzumab as well as TK inhibition are clinically effective anti-HER-2 strategies. Kinase inhibitors offer some potential therapeutic advantages over antibody-based therapies. Being small molecules, TK inhibitors (TKIs) have oral bioavailability and ability to cross the blood-brain barrier. Because of their different mode of action, TKIs may be able to overcome some of the mechanisms of trastuzumab resistance. Preclinical, and limited clinical data also suggest that TKIs and trastuzumab have synergistic activity. Lapatinib is the only TKI available for clinical use at present, but several molecules with anti-HER-2 activity have been identified and are undergoing evaluation. These differ in the spectrum of kinases that they inhibit, potency of HER-2 inhibition, pharmacokinetic properties, and toxicity profiles, and are at various stages of clinical development. In this article we summarize selected HER-2 TKIs approved for clinical use or in development for which clinical data are available. PMID:19887469

  11. HER2 testing in gastric cancer: An update

    PubMed Central

    Abrahao-Machado, Lucas Faria; Scapulatempo-Neto, Cristovam

    2016-01-01

    Human epidermal growth factor receptor 2 (HER2) overexpression is increasingly recognized as a frequent molecular abnormality in gastric and gastroesophageal cancer. With the recent introduction of HER2 molecular targeted therapy for patients with advanced gastric cancer, determination of HER2 status is crucial in order to select patients who may benefit from this treatment. This paper provides an update on our knowledge of HER2 in gastric and gastroesophageal cancer, including the prognostic relevance of HER2, the key differences between HER2 protein expression interpretation in breast and gastric cancer, the detection methods and the immunohistochemistry scoring system. PMID:27217694

  12. Determination of HER2 status using both serum HER2 levels and circulating tumor cells in patients with recurrent breast cancer whose primary tumor was HER2 negative or of unknown HER2 status

    PubMed Central

    Fehm, Tanja; Becker, Sven; Duerr-Stoerzer, Silke; Sotlar, Karl; Mueller, Volkmar; Wallwiener, Diethelm; Lane, Nancy; Solomayer, Erich; Uhr, Jonathan

    2007-01-01

    Introduction At the time when metastatic disease is identified, assessment of human epidermal growth factor receptor (HER)2 status might help to optimize treatment decisions if HER2 status was not determined at first diagnosis and if HER2 positivity has been acquired during disease progression. Within this context, determination of serum HER2 or evaluation of HER2 status in circulating tumor cells (CTCs) may be of clinical relevance because metastatic tissue may be difficult to obtain for analysis as a result of its localization. The aim of this study was therefore to determine the HER2 status in serum and corresponding CTCs in patients with metastatic breast cancer whose primary tumors were HER2 negative or of unknown HER2 status. Methods Blood samples were obtained from 77 metastatic breast cancer patients with negative (n = 44) or unknown (n = 33) HER2 status. Serum HER2 was determined using a commercial HER2/neu ELISA kit. CTCs were detected by slide-based assay using immunomagnetic enrichment and characterized by phenotyping and genotyping. Alternatively, a commercial kit, based on RT-PCR, was used to detect and characterize CTCs. Results Twenty out of 77 patients with metastatic disease had elevated serum levels of HER2. Blood samples could be analyzed for the presence of CTCs in 67 patients. Eight out of 21 patients with detectable CTCs exhibited HER2 amplification. Twenty-three out of 77 patients were HER2 positive using at least one method. Concordance between HER2 status of CTCs and serum HER2 was observed in 15 of 21 patients (71%). In six patients conflicting results were obtained. Three patients with elevated serum HER2 status had HER2-negative CTCs, whereas three patients with HER2-positive CTCs had normal serum HER2 levels. Conclusion A subgroup of patients with initially negative or unknown HER2 status can have elevated serum HER2 levels and/or HER2-positive CTCs at the time of development of metastatic disease. Although only a small number of

  13. HER2 testing in gastric cancer: An update.

    PubMed

    Abrahao-Machado, Lucas Faria; Scapulatempo-Neto, Cristovam

    2016-05-21

    Human epidermal growth factor receptor 2 (HER2) overexpression is increasingly recognized as a frequent molecular abnormality in gastric and gastroesophageal cancer. With the recent introduction of HER2 molecular targeted therapy for patients with advanced gastric cancer, determination of HER2 status is crucial in order to select patients who may benefit from this treatment. This paper provides an update on our knowledge of HER2 in gastric and gastroesophageal cancer, including the prognostic relevance of HER2, the key differences between HER2 protein expression interpretation in breast and gastric cancer, the detection methods and the immunohistochemistry scoring system. PMID:27217694

  14. Serum HER2 levels are increased in cats with mammary carcinomas and predict tissue HER2 status

    PubMed Central

    Soares, Maria; Ribeiro, Rita; Najmudin, Shabir; Gameiro, Andreia; Rodrigues, Rita; Cardoso, Fátima; Ferreira, Fernando

    2016-01-01

    HER2 is overexpressed in about 30% of feline mammary carcinomas (FMC) and in 15-30% of breast cancers. Women with HER2-positive breast tumors are associated with shorter survival. This study aimed to optimize the detection and quantification of serum HER2 (sHER2) in cats and to evaluate its potential in diagnosing cats with mammary carcinomas (MC) overexpressing HER2. A prospective study was conducted in 60 queens showing MC and 20 healthy animals. Pre-operative serum samples were collected for sHER2 quantification using two immunoassays: ELISA and Dot blot assay. sHER2 levels were compared with tissue HER2 status assessed by immunohistochemistry. Queens with FMC showed significantly higher mean levels of sHER2 by both ELISA and Dot blot assay. A significant difference in the sHER2 levels was also found between cats with HER2-positive MC and those with low-expressing HER2 MC. A significant correlation between sHER2 levels and tumor HER2 status was also found, particularly when ELISA was used (r = 0.58, p < 0.0001). The value of 10 ng/ml was proposed as the optimal cutoff for both immunoassays by ROC analysis. Like in humans, sHER2 levels are increased in cats with MC HER2-positive, strongly suggesting that evaluation of sHER2 levels can be very useful in feline oncology. The results show that ELISA and Dot blot assay can replace the immunohistochemistry technique, due to their efficacy and lower costs for diagnostic purposes and for monitoring the response to anti-HER2 therapies in cats. PMID:26909614

  15. Serum HER2 levels are increased in cats with mammary carcinomas and predict tissue HER2 status.

    PubMed

    Soares, Maria; Ribeiro, Rita; Najmudin, Shabir; Gameiro, Andreia; Rodrigues, Rita; Cardoso, Fátima; Ferreira, Fernando

    2016-04-01

    HER2 is overexpressed in about 30% of feline mammary carcinomas (FMC) and in 15-30% of breast cancers. Women with HER2-positive breast tumors are associated with shorter survival. This study aimed to optimize the detection and quantification of serum HER2 (sHER2) in cats and to evaluate its potential in diagnosing cats with mammary carcinomas (MC) overexpressing HER2. A prospective study was conducted in 60 queens showing MC and 20 healthy animals. Pre-operative serum samples were collected for sHER2 quantification using two immunoassays: ELISA and Dot blot assay. sHER2 levels were compared with tissue HER2 status assessed by immunohistochemistry. Queens with FMC showed significantly higher mean levels of sHER2 by both ELISA and Dot blot assay. A significant difference in the sHER2 levels was also found between cats with HER2-positive MC and those with low-expressing HER2 MC. A significant correlation between sHER2 levels and tumor HER2 status was also found, particularly when ELISA was used (r = 0.58, p < 0.0001). The value of 10 ng/ml was proposed as the optimal cutoff for both immunoassays by ROC analysis. Like in humans, sHER2 levels are increased in cats with MC HER2-positive, strongly suggesting that evaluation of sHER2 levels can be very useful in feline oncology. The results show that ELISA and Dot blot assay can replace the immunohistochemistry technique, due to their efficacy and lower costs for diagnostic purposes and for monitoring the response to anti-HER2 therapies in cats. PMID:26909614

  16. HER-2/neu raises SHP-2, stops IFN-{gamma} anti-proliferation in bladder cancer

    SciTech Connect

    Su, W.-P.; Tu, I-H.; Hu, S.-W.; Yeh, H.-H.; Shieh, D.-B.; Chen, T.-Y.; Su, W.-C. . E-mail: sunnysu@mail.ncku.edu.tw

    2007-04-27

    Gene amplification or HER-2/neu protein overexpression signals a poor outcome for bladder cancer patients. We investigated the anti-proliferative effect of IFN-{gamma} in HER-2/neu-transfected human bladder cancer cells (TCC-N5 and TCC-N10). The cells continued growing after IFN-{gamma} stimulation but did not activate the Janus kinase (Jak)/Stat pathway. We found Jak/Stat protein phosphatase in TCC-N5 and TCC-N10 cells with upregulated Src homology 2-containing protein tyrosine phosphatase-2 (SHP-2). After the cells had been treated with AG825, a HER-2/neu-specific inhibitor, SHP-2 expression declined, and Jak2/Stat1 reactivated. Similar results were reported in a mouse bladder cancer cell line, MBT2, with constitutive HER-2/neu overexpression. Further, AG825 pretreatment restored the anti-proliferation activity of IFN-{gamma} in TCC-N5 and TCC-N10 cells. Therefore, the suppression of IFN-{gamma} signaling in HER-2/neu-overexpressing bladder cancer cells might be due to SHP-2 upregulation. The regulation of SHP-2 by HER-2/neu provides a new target for blocking the HER-2/neu oncogenic pathwa000.

  17. Novel bright field molecular morphology methods for detection of HER2 gene amplification.

    PubMed

    Tubbs, Raymond; Pettay, James; Hicks, David; Skacel, Marek; Powell, Richard; Grogan, Tom; Hainfeld, James

    2004-08-01

    Profiling the amplification and over-expression of the HER2 gene is a key component for defining the prognosis and management of invasive breast carcinoma. Clinical laboratory testing for HER2 gene amplification and over expression has been complicated by an unacceptably high rate of false positive immunohistochemistry (IHC) results, poor reproducibility for the '2+' category of IHC scoring, and reluctant acceptance of alternative testing by fluorescence in situ hybridization (FISH) by the diagnostic pathology community. Novel chromogenic in situ hybridization (CISH) assays have been developed that utilize bright field microscopy and a conventional light microscope for interpretation, but the analytical sensitivity of first generation CISH systems has been problematic. Novel second generation in situ hybridization detection methods based upon polymerized lg detection chemistry, autometallography or enzyme metallography, have been developed that routinely detect endogenous HER2 signals in normal cells (on slide hybridization control) and HER2 signals in both non-amplified and amplified patterns of HER2 genomic signatures. By combining the strength of polymerized peroxidase-labeled antibodies and metallography for gene amplification, with the detection of expression of HER2 encoded protein by IHC on the same slide, both HER2 gene amplification and protein over-expression can be simultaneously evaluated on a cell-by-cell basis in each microscopic field of carcinoma. PMID:15614612

  18. Evaluation of Her2 status using photoacoustic spectroscopic CT techniques

    NASA Astrophysics Data System (ADS)

    Shaffer, Michael; Kruger, Robert; Reinecke, Daniel; Chin-Sinex, Helen; Mendonca, Marc; Stantz, Keith M.

    2010-02-01

    Purpose: The purpose of this study is to determine the feasibility of using photacoustic CT spectroscopy(PCT-s) to track a near infrared dye conjugated with trastuzumab in vivo. Materials and Methods: An animal model was developed which contained both high and low Her2 expression tumor xenografts on the same mouse. The tumors were imaged at multiple wavelengths (680- 950nm) in the PCT scanner one day prior to injection of the near infrared conjugated probe. Baseline optical imaging data was acquired and the probe was then injected via the tail vein. Fluorescence data was acquired over the next week, PCT spectroscopic data was also acquired during this timeframe. The mice were sacrificed and tumors were extirpated and sent to pathology for IHC staining to verify Her2 expression levels. The optical fluorescence images were analyzed to determine probe uptake dynamics. Reconstructed PCT spectroscopic data was analyzed using IDL routines to deconvolve the probe signal from endogenous background signals, and to determine oxygen saturation. Results: The location of the NIR conjugate was able to be identified within the tumor utilizing IDL fitting routines, in addition oxygen saturation, and hemoglobin concentrations were discernible from the spectroscopic data. Conclusion: Photacoustic spectroscopy allows for the determination of in vivo tumor drug delivery at greater depths than can be determined from optical imaging techniques.

  19. Acquired resistance to anti-EGFR mAb ICR62 in cancer cells is accompanied by an increased EGFR expression, HER-2/HER-3 signalling and sensitivity to pan HER blockers

    PubMed Central

    Khelwatty, Said A; Essapen, Sharadah; Seddon, Alan M; Fan, Zhen; Modjtahedi, Helmout

    2015-01-01

    Background: The human epidermal growth factor receptor (EGFR) is an important target for cancer treatment. Currently, only the EGFR antibodies cetuximab and panitumumab are approved for the treatment of patients with colorectal cancer. However, a major clinical challenge is a short-term response owing to development of acquired resistance during the course of the treatment. Methods: In this study, we investigated the molecular mechanisms underlying development of acquired resistance in DiFi colorectal cancer cells to the anti-EGFR mAb ICR62 (termed DiFi62) and to the small molecule tyrosine kinase inhibitor (TKI) gefitinib (termed DiFiG) using a range of techniques. Results: Compared with the findings from parental DiFi and DiFiG cells, development of acquired resistance to anti-EGFR mAb ICR62 in DiFi62 cells was accompanied by an increase in cell surface EGFR and increased phosphorylation of HER-2 and HER-3. Interestingly, DiFi62 cells also acquired resistance to treatment with anti-EGFR mAbs cetuximab and ICR61, which bind to other distinct epitopes on the extracellular domain of EGFR, but these cells remained equally sensitive as the parental cells to treatment with pan-HER inhibitors such as afatinib. Conclusions: Our results provide a novel mechanistic insight into the development of acquired resistance to EGFR antibody-based therapy in colorectal cancer cells and justify further investigations on the therapeutic benefits of pan-HER family inhibitors in the treatment of colorectal cancer patients once acquired resistance to EGFR antibody-based therapy is developed. PMID:26372697

  20. HSP90 expression and its association with wighteone metabolite response in HER2-positive breast cancer cells

    PubMed Central

    CAO, ZHONG-WEI; ZENG, QIAN; PEI, HAI-JIANG; REN, LI-DONG; BAI, HAI-ZHEN; NA, RI-NA

    2016-01-01

    It is well known that heat shock protein 90 (HSP90) overexpression is correlated with poor prognosis and chemo-resistance in human malignant cancers. At the same time, wighteone, or 6-prenyl-5,7,4′-trihydroxyisoflavone, a major isoflavone component of the ornamental tall tree Erythrina suberosa, has been demonstrated to exhibit a potent anti-proliferative effect on human leukemia HL-60 cancer cell lines. In this study, the effects of wighteone on the proliferation of HER2-positive breast cancer cells were investigated, and the action mechanism was explored. MCF-7 HER2-positive breast cancer cells were treated with various concentrations of wighteone. The growth inhibitory rate of the cells was calculated by MTT assay, apoptosis was detected by flow cytometry, and the expression level of HSP90 was assessed by western blot analysis. The addition of wighteone at concentrations ranging from 1–10 g/ml in the medium for 48 h had a marked inhibition on the proliferation of HER2-positive cancer cell lines. The growth inhibitory rates with 0.5, 2 or 8 mM wighteone were significantly higher compared with the control group. Apoptosis in the wighteone-treated cells was also significantly higher compared with the control group. The expression level of HSP90 in the wighteone group was significantly lower than that in the control group. Our findings demonstrated that wighteone effectively inhibited the proliferation of HER2-positive cancer cell lines, and this is considered to be the result of downregulating HSP90 receptor and downstream signaling. PMID:27313682

  1. Oncogenic AKT1(E17K) mutation induces mammary hyperplasia but prevents HER2-driven tumorigenesis

    PubMed Central

    Mancini, Maria L.; Lien, Evan C.; Toker, Alex

    2016-01-01

    One of the most frequently deregulated signaling pathways in breast cancer is the PI 3-K/Akt cascade. Genetic lesions are commonly found in PIK3CA, PTEN, and AKT, which lead to excessive and constitutive activation of Akt and downstream signaling that results in uncontrolled proliferation and increased cellular survival. One such genetic lesion is the somatic AKT1(E17K) mutation, which has been identified in 4-8% of breast cancer patients. To determine how this mutation contributes to mammary tumorigenesis, we constructed a genetically engineered mouse model that conditionally expresses human AKT1(E17K) in the mammary epithelium. Although AKT1(E17K) is only weakly constitutively active and does not promote proliferation in vitro, it is capable of escaping negative feedback inhibition to exhibit sustained signaling dynamics in vitro. Consistently, both virgin and multiparous AKT1(E17K) mice develop mammary gland hyperplasia that do not progress to carcinoma. This hyperplasia is accompanied by increased estrogen receptor expression, although exposure of the mice to estrogen does not promote tumor development. Moreover, AKT1(E17K) prevents HER2-driven mammary tumor formation, in part through negative feedback inhibition of RTK signaling. Analysis of TCGA breast cancer data revealed that the mRNA expression, total protein levels, and phosphorylation of various RTKs are decreased in human tumors harboring AKT1(E17K). PMID:27004402

  2. Hyperthermia-triggered intracellular delivery of anticancer agent to HER2+ cells by HER2-specific Affibody (ZHER2-GS-Cys)-Conjugated Thermosensitive Liposomes (HER2+ Affisomes)

    PubMed Central

    Smith, Brandon; Lyakhov, Ilya; Loomis, Kristin; Needle, Danielle; Baxa, Ulrich; Yavlovich, Amichai; Capala, Jacek; Blumenthal, Robert; Puri, Anu

    2011-01-01

    We previously reported the formulation and physical properties of HER2 (Human Epidermal Growth Factor Receptor 2)-specific Affibody (ZHER2:342-Cys) conjugated thermosensitive liposomes (HER2+ Affisomes). Here we examined localized delivery potential of these Affisomes by monitoring cellular interactions, intracellular uptake, and hyperthermia-induced effects on drug delivery. We modified ZHER2:342-Cys by introducing a glycine-serine spacer before the C-terminus cysteine (called ZHER2-GS-Cys) to achieve accessibility to cell-surface expressed HER2. This modification did not affect HER2-specific binding and ZHER2-GS-Cys retained its ability to conjugate to the liposomes containing dipalmitoyl phosphatidyl choline: DSPE-PEG2000-Malemide, 96:04 mole ratios (HER2+ Affisomes). HER2+ Affisomes were either (i) fluorescently labeled with rhodamine-PE and calcein or (ii) loaded with an anticancer drug Doxorubicin (DOX). Fluorescently labeled HER2+ Affisomes showed at least 10 fold increase in binding to HER2+ cells (SK-BR-3) when compared to HER2− cells (MDA-MB-468) at 37°C. A competition experiment using free ZHER2-GS-Cys blocked HER2+ Affisomes-SK-BR-3 cell associations. Imaging with confocal microscopy showed that HER2+ Affisomes accumulated in the cytosol of SK-BR-3 cells at 37°C. Hyperthermia-induced intracellular release experiments showed that the treatment of HER2+ Affisome/SK-BR-3 cell complexes with a 45°C (±1°C) pre-equilibrated buffer resulted in cytosolic delivery of calcein. Substantial calcein release was observed within 20 minutes at 45°C, with no effect on cell viability under these conditions. Similarly, DOX-loaded HER2+ Affisomes showed at least 2–3 fold higher accumulation of DOX in SK-BR-3 cells as compared to control liposomes. DOX-mediated cytotoxicity was more pronounced in SK-BR-3 cells especially at lower doses of HER2+ Affisomes. Brief exposure of liposome-cell complexes at 45°C prior to the onset of incubations for cell killing assays

  3. High HER2 protein levels correlate with increased survival in breast cancer patients treated with anti-HER2 therapy

    PubMed Central

    Aura, Claudia; Garrido-Castro, Ana; Vilaro, Marta; Peg, Vicente; Jimenez, José; Vicario, Rocio; Cecchi, Fabiola; Hoos, William; Burrows, Jon; Hembrough, Todd; Ferreres, Juan Carles; Perez-Garcia, José; Arribas, Joaquin; Cortes, Javier; Scaltriti, Maurizio

    2016-01-01

    Introduction Current methods to determine HER2 (human epidermal growth factor receptor 2) status are affected by reproducibility issues and do not reliably predict benefit from anti-HER2 therapy. Quantitative measurement of HER2 may more accurately identify breast cancer (BC) patients who will respond to anti-HER2 treatments. Methods Using selected reaction monitoring mass spectrometry (SRM-MS), we quantified HER2 protein levels in formalin-fixed, paraffin-embedded (FFPE) tissue samples that had been classified as HER2 0, 1+, 2+ or 3+ by immunohistochemistry (IHC). Receiver operator curve (ROC) analysis was conducted to obtain optimal HER2 protein expression thresholds predictive of HER2 status (by standard IHC or in situ hybridization [ISH]) and of survival benefit after anti-HER2 therapy. Results Absolute HER2 amol/μg levels were significantly correlated with both HER2 IHC and amplification status by ISH (p < 0.0001). A HER2 threshold of 740 amol/μg showed an agreement rate of 94% with IHC and ISH standard HER2 testing (p < 0.0001). Discordant cases (SRM-MS-negative/ISH-positive) showed a characteristic amplification pattern known as double minutes. HER2 levels >2200 amol/μg were significantly associated with longer disease-free survival (DFS) and overall survival (OS) in an adjuvant setting and with longer OS in a metastatic setting. Conclusion Quantitative HER2 measurement by SRM-MS is superior to IHC and ISH in predicting outcome after treatment with anti-HER2 therapy. PMID:26422389

  4. Human Epidermal Growth Factor Receptor Family-Targeted Therapies in the Treatment of HER2-Overexpressing Breast Cancer

    PubMed Central

    Eroglu, Zeynep; Tagawa, Tomoko

    2014-01-01

    Breast cancer characterized by overexpression of human epidermal growth factor receptor 2 (HER2) has been associated with more aggressive disease progression and a poorer prognosis. Although an improved understanding of breast cancer pathogenesis and the role of HER2 signaling has resulted in significant survival improvements in the past 20 years, resistance to HER2-targeted therapy remains a concern. A number of strategies to prevent or overcome resistance to HER2-targeted therapy in breast cancer are being evaluated. This article provides a comprehensive review of (a) the role of HER2 signaling in breast cancer pathogenesis, (b) potential receptor and downstream therapeutic targets in breast cancer to overcome resistance to HER2-targeted therapy, and (c) clinical trials evaluating agents targeting one or more members of the HER family and/or downstream pathways for the treatment of breast cancer, with a focus on metastatic disease. PMID:24436312

  5. HER2- and EGFR-specific affiprobes: novel recombinant optical probes for cell imaging.

    PubMed

    Lyakhov, Ilya; Zielinski, Rafal; Kuban, Monika; Kramer-Marek, Gabriela; Fisher, Robert; Chertov, Oleg; Bindu, Lakshman; Capala, Jacek

    2010-02-15

    The human epidermal growth factor receptors, EGFR and HER2, are members of the EGFR family of cell-surface receptors/tyrosine kinases. EGFR- and HER2-positive cancers represent a more aggressive disease with greater likelihood of recurrence, poorer prognosis, and decreased survival rate, compared to EGFR- or HER2-negative cancers. The details of HER2 proto-oncogenic functions are not deeply understood, partially because of a restricted availability of tools for EGFR and HER2 detection (A. Sorkin and L. K. Goh, Exp. Cell Res. 2009, 315, 683-696). We have created photostable and relatively simple-to-produce imaging probes for in vitro staining of EGFR and HER2. These new reagents, called affiprobes, consist of a targeting moiety, a HER2- or EGFR-specific Affibody molecule, and a fluorescent moiety, mCherry (red) or EGFP (green). Our flow cytometry and confocal microscopy experiments demonstrated high specificity and signal/background ratio of affiprobes. Affiprobes are able to stain both live cells and frozen tumor xenograph sections. This type of optical probe can easily be extended for targeting other cell-surface antigens/ receptors. PMID:20052708

  6. Radionuclide therapy of HER2-positive microxenografts using a 177Lu-labeled HER2-specific Affibody molecule.

    PubMed

    Tolmachev, Vladimir; Orlova, Anna; Pehrson, Rikard; Galli, Joakim; Baastrup, Barbro; Andersson, Karl; Sandström, Mattias; Rosik, Daniel; Carlsson, Jörgen; Lundqvist, Hans; Wennborg, Anders; Nilsson, Fredrik Y

    2007-03-15

    A radiolabeled anti-HER2 Affibody molecule (Z(HER2:342)) targets HER2-expressing xenografts with high selectivity and gives good imaging contrast. However, the small size (approximately 7 kDa) results in rapid glomerular filtration and high renal accumulation of radiometals, thus excluding targeted therapy. Here, we report that reversible binding to albumin efficiently reduces the renal excretion and uptake, enabling radiometal-based nuclide therapy. The dimeric Affibody molecule (Z(HER2:342))(2) was fused with an albumin-binding domain (ABD) conjugated with the isothiocyanate derivative of CHX-A''-DTPA and labeled with the low-energy beta-emitter (177)Lu. The obtained conjugate [CHX-A''-DTPA-ABD-(Z(HER2:342))(2)] had a dissociation constant of 18 pmol/L to HER2 and 8.2 and 31 nmol/L for human and murine albumin, respectively. The radiolabeled conjugate displayed specific binding to HER2-expressing cells and good cellular retention in vitro. In vivo, fusion with ABD enabled a 25-fold reduction of renal uptake in comparison with the nonfused dimer molecule (Z(HER2:342))(2). Furthermore, the biodistribution showed high and specific uptake of the conjugate in HER2-expressing tumors. Treatment of SKOV-3 microxenografts (high HER2 expression) with 17 or 22 MBq (177)Lu-CHX-A''-DTPA-ABD-(Z(HER2:342))(2) completely prevented formation of tumors, in contrast to mice given PBS or 22 MBq of a radiolabeled non-HER2-binding Affibody molecule. In LS174T xenografts (low HER2 expression), this treatment resulted in a small but significant increase of the survival time. Thus, fusion with ABD improved the in vivo biodistribution, and the results highlight (177)Lu-CHX-A''-DTPA-ABD-(Z(HER2:342))(2) as a candidate for treatment of disseminated tumors with a high level of HER2 expression. PMID:17363599

  7. HER2 Expression Beyond Breast Cancer: Therapeutic Implications for Gynecologic Malignancies

    PubMed Central

    English, Diana P.; Roque, Dana M.; Santin, Alessandro D.

    2013-01-01

    HER2 or ErbB2 is a member of the epidermal growth factor family and is overexpressed in subsets of breast, ovarian, gastric, colorectal, pancreatic and endometrial cancers. HER2 regulates signaling through several pathways (Ras/Raf/mitogen-activated protein kinase and phosphatidylinositol-3 kinase/protein kinase-B/mammalian target of rapamycin pathways) associated with cell survival and proliferation. HER2 overexpressed and/or gene amplified tumors are generally regarded as biologically aggressive neoplasms. In breast, cervical, endometrial and ovarian cancer, there have been several studies linking the amplification of the c-erbB2 gene with chemo-resistance and overall poor survival. Tyrosine kinase inhibitors and immunotherapy with monoclonal antibodies targeting HER2 holds promise for patients harboring these aggressive neoplasms. Trastuzumab combined with cytotoxic chemotherapy agents or conjugated with radioactive isotopes is currently being investigated in clinical trials of several tumor types. PMID:23529353

  8. Computer-aided detection of HER2 amplification status using FISH images: a preliminary study

    NASA Astrophysics Data System (ADS)

    Zheng, Bin; Wang, Xiao-Hui; Surti, Urvashi; Bhargava, Rohit; Gur, David

    2009-02-01

    The amplification status of human epidermal growth factor receptors 2 (HER2) genes is strongly associated with clinical outcome in patients with breast cancer. The American Society of Clinical Oncology Tumor Marker Guidelines Panel has recommended routine testing of HER2 status on all newly diagnosed metastatic breast cancers since 2001. Although fluorescent in situ hybridization (FISH) technology provides superior accuracy as compared with other approaches, current manual FISH analysis methods are somewhat subjective, tedious, and may introduce interreader variability. The goal of this preliminary study is to develop and test a computer-aided detection (CAD) scheme to assess HER2 status using FISH images. Forty FISH images were selected for this study from our genetic laboratory. The CAD scheme first applies an adaptive, iterative threshold method followed by a labeling algorithm to segment cells of possible interest. A set of classification rules is then used to identify analyzable interphase cells and discard nonanalyzable cells due to cell overlapping and/or other image staining debris (or artifacts). The scheme then maps the detected analyzable cells onto two other gray scale images corresponding to the red and green color of the original image followed by application of a raster scan and labeling algorithms to separately detect the HER-2/neu ("red") and CEP17 ("green") FISH signals. A simple distance based criterion is applied to detect and merge split FISH signals within each cell. The CAD scheme computes the ratio between independent "red" and "green" FISH signals of all analyzable cells identified on an image. If the ratio is >= 2.0, the FISH image is assumed to have been acquired from a HER2+ case; otherwise, the FISH image is assumed to have been acquired from HER2- case. When we applied the CAD scheme to the testing dataset, the average computed HER2 amplification ratios were 1.06+/-0.25 and 2.53+/-0.81 for HER2- and HER2+ samples, respectively. The

  9. Brain metastases in Asian HER2-positive breast cancer patients: anti-HER2 treatments and their impact on survival

    PubMed Central

    Yap, Y S; Cornelio, G H; Devi, B C R; Khorprasert, C; Kim, S B; Kim, T Y; Lee, S C; Park, Y H; Sohn, J H; Sutandyo, N; Wong, D W Y; Kobayashi, M; Landis, S H; Yeoh, E M; Moon, H; Ro, J

    2012-01-01

    Background: In Asia, large-scale studies on anti-HER2 treatment in HER2-positive breast cancer patients with brain metastases are limited. We studied the treatment patterns of these patients in Asia to evaluate the impact of anti-HER2 treatment on the time to occurrence of brain metastases (TTBM) and survival after brain metastasis (BM). Methods: A retrospective study of HER2-positive breast cancer patients diagnosed with BM between January 2006 and December 2008 in six Asian countries was conducted. Demographics, tumour characteristics, treatment details, and events dates were collected from medical records. Results: Data from 280 patients were analysed. Before BM, 63% received anti-HER2 treatment. These patients had significantly longer TTBM than those without anti-HER2 treatment (median 33 vs 19 months; P<0.002). After BM, 93% received radiotherapy, 57% received chemotherapy, and 41% received anti-HER2 treatment (trastuzumab and/or lapatinib). Use of both anti-HER2 agents, primarily sequentially, after BM demonstrated the longest survival after BM and was associated with a significant survival benefit over no anti-HER2 treatment (median 26 vs 6 months; hazard ratio 0.37; 95% CI 0.19–0.72). Conclusion: Anti-HER2 treatment before BM was associated with longer TTBM. Anti-HER2 treatment after BM was associated with a survival benefit, especially when both trastuzumab and lapatinib were utilised. PMID:22918394

  10. Overcoming Therapeutic Resistance in HER2-Positive Breast Cancers with CDK4/6 Inhibitors.

    PubMed

    Goel, Shom; Wang, Qi; Watt, April C; Tolaney, Sara M; Dillon, Deborah A; Li, Wei; Ramm, Susanne; Palmer, Adam C; Yuzugullu, Haluk; Varadan, Vinay; Tuck, David; Harris, Lyndsay N; Wong, Kwok-Kin; Liu, X Shirley; Sicinski, Piotr; Winer, Eric P; Krop, Ian E; Zhao, Jean J

    2016-03-14

    Using transgenic mouse models, cell line-based functional studies, and clinical specimens, we show that cyclin D1/CDK4 mediate resistance to targeted therapy for HER2-positive breast cancer. This is overcome using CDK4/6 inhibitors. Inhibition of CDK4/6 not only suppresses Rb phosphorylation, but also reduces TSC2 phosphorylation and thus partially attenuates mTORC1 activity. This relieves feedback inhibition of upstream EGFR family kinases, resensitizing tumors to EGFR/HER2 blockade. Consequently, dual inhibition of EGFR/HER2 and CDK4/6 invokes a more potent suppression of TSC2 phosphorylation and hence mTORC1/S6K/S6RP activity. The suppression of both Rb and S6RP enhances G1 arrest and a phenotype resembling cellular senescence. In vivo, CDK4/6 inhibitors sensitize patient-derived xenograft tumors to HER2-targeted therapies and delay tumor recurrence in a transgenic model of HER2-positive breast cancer. PMID:26977878

  11. ScFv-decorated PEG-PLA-based nanoparticles for enhanced siRNA delivery to Her2⁺ breast cancer.

    PubMed

    Dou, Shuang; Yang, Xian-Zhu; Xiong, Meng-Hua; Sun, Chun-Yang; Yao, Yan-Dan; Zhu, Yan-Hua; Wang, Jun

    2014-11-01

    Patients with Her2-overexpressing (Her2(+)) breast cancers generally have a poorer prognosis due to the high aggressiveness and chemoresistance of the disease. Small interfering RNA (siRNA) targeting the gene encoding polo-like kinase 1 (Plk1; siPlk1) has emerged as an efficient therapeutic agent for Her2(+) breast cancers. Poly(ethylene glycol)-block-poly(D,L-lactide) (PEG-PLA)-based nanoparticles for siRNA delivery were previously developed and optimized. In this study, for targeted delivery of siPlk1 to Her2(+) breast cancer, anti-Her2 single-chain variable fragment antibody (ScFv(Her2))-decorated PEG-PLA-based nanoparticles with si Plk1 encapsulation (ScFv(Her2)-NP(si) Plk1) are developed. With the rationally designed conjugation site, ScFv(Her2)-NP(siRNA) can specifically bind to the Her2 antigen overexpressed on the surface of Her2(+) breast cancer cells. Therefore, ScFv(Her2)-NP(si) Plk1 exhibits improved cellular uptake, promoted Plk1 silencing efficiency, and induced enhanced tumor cell apoptosis in Her2(+) breast cancer cells, when compared with nontargeted NP(si) Plk1. More importantly, ScFv(Her2)-NP(siRNA) markedly enhances the accumulation of siRNA in Her2(+) breast tumor tissue, and remarkably improves the efficacy of tumor suppression. Dose-dependent anti-tumor efficacy further demonstrates that ScFvHer2 -decorated PEG-PLA-based nanoparticles with siPlk1 encapsulation can significantly enhance the inhibition of Her2(+) breast tumor growth and reduce the dose of injected siRNA. These results suggest that ScFvHer2 -decorated PEG-PLA-based nanoparticles show great potential for targeted RNA interference therapy of Her2(+) breast tumor. PMID:24947820

  12. Pertuzumab in combination with trastuzumab and docetaxel for HER2-positive metastatic breast cancer.

    PubMed

    Kawajiri, Hidemi; Takashima, Tsutomu; Kashiwagi, Shinichiro; Noda, Satoru; Onoda, Naoyoshi; Hirakawa, Kosei

    2015-01-01

    Overexpression of HER2 - found in approximately 15-20% of all breast cancers - is a negative prognostic factor. Although trastuzumab significantly improves the prognosis of HER2-positive breast cancer, half of the patients with metastatic breast cancer experience disease progression within 1 year. Pertuzumab is a novel HER2-targeted humanized monoclonal antibody that binds to the dimerization domain of HER2 and acts synergically with trastuzumab in inhibiting tumor progression. The CLEOPATRA trial demonstrated that adding pertuzumab to trastuzumab plus docetaxel significantly prolonged progression-free survival and overall survival without increasing severe adverse events. Conclusively, pertuzumab was approved by the US FDA in June 2012 for use in combination with trastuzumab and docetaxel for the treatment of patients with HER2-positive metastatic breast cancer. Furthermore, various clinical trials to evaluate the efficacy and safety of pertuzumab combined with other cytotoxic agents are ongoing at present. Thus, pertuzumab has been becoming important for the treatment of patients with HER2-positive metastatic breast cancer. PMID:25494663

  13. Testing for HER2 in Breast Cancer: A Continuing Evolution

    PubMed Central

    Shah, Sejal; Chen, Beiyun

    2011-01-01

    Human epidermal growth factor receptor 2 (HER2) is an important prognostic and predictive factor in breast cancer. HER2 is overexpressed in approximately 15%–20% of invasive breast carcinomas and is associated with earlier recurrence, shortened disease free survival, and poor prognosis. Trastuzumab (Herceptin) a “humanized” monoclonal antibody targets the extracellular domain of HER2 and is widely used in the management of HER2 positive breast cancers. Accurate assessment of HER2 is thus critical in the management of breast cancer. The aim of this paper is to present a comprehensive review of HER2 with reference to its discovery and biology, clinical significance, prognostic value, targeted therapy, current and new testing modalities, and the interpretation guidelines and pitfalls. PMID:21188214

  14. Quantitative measurements of HER2 and phospho-HER2 expression: correlation with pathologic response to neoadjuvant chemotherapy and trastuzumab

    PubMed Central

    2014-01-01

    Background Preoperative therapy with chemotherapy and the HER2-targeted monoclonal antibody trastuzumab is valuable for patients with large or locally advanced HER2-positive (HER2+) breast cancers but traditional methods of measuring HER2 expression do not accurately stratify patients for likelihood of response. Quantitative immunofluorescent approaches have the potential to provide a mathematically continuous measure of HER2. Here we seek to determine whether quantitative measurement of HER2 or phospho-HER2 correlates with likelihood of response to trastuzumab- containing neoadjuvant therapy. Methods We evaluated core biopsy samples from 27 HER2+ breast cancer patients enrolled in a preoperative clinical trial using trastuzumab, nab-paclitaxel and carboplatin combination therapy (BrUOG BR-211B (NCT00617942)). Tumor core biopsies were taken before initiation of treatment and 9–13 days after patients received "run-in" doses of either single agent trastuzumab or nab-paclitaxel. The AQUA method of quantitative immunofluorescence was used for analysis of in situ protein expression. Patients then received 18 weeks of treatment, followed by surgery to assess pathologic response to the neoadjuvant regimen. Results A HER2 score of 2111 by AQUA analysis has been shown to be equivalent to HER2 3+ by immunohistochemical staining in previous studies. Of 20 evaluable patients, 10 cases who achieved a pathologic complete response (pathCR) with neoadjuvant treatment had a mean HER2 level of 10251 compared with 4766 in the patients without pathCR (p = 0.0021). Measurement of phospho-HER2 showed no difference in pathCR vs non-pathCR groups. In 9 patients who had HER2 levels repeated after a single treatment with trastuzumab there was no evidence of a reduction in the HER2 or phospho-HER2 levels following that exposure. Conclusions High levels of HER2 are associated with achievement of a pathCR in the preoperative setting, while levels of Phospho-HER2 were not predictive of

  15. Evaluation of the anti-HER2 C6.5 diabody as a PET radiotracer to monitor HER2 status and predict response to trastuzumab treatment

    PubMed Central

    Reddy, Smitha; Shaller, Calvin C.; Doss, Mohan; Shchaveleva, Irina; Marks, James D.; Yu, Jian Q.; Robinson, Matthew K.

    2011-01-01

    Purpose The rapid tumor targeting and pharmacokinetic properties of engineered antibodies make them potentially suitable for use in imaging strategies to predict and monitor response to targeted therapies. This study aims to evaluate C6.5 diabody (C6.5db), a non-covalent anti-HER2 single chain-Fv dimer, as a radiotracer for predicting response to HER2-targeted therapies such as trastuzumab. Experimental Design Immunodeficient mice bearing established HER2-positive tumor xenografts were injected with radioiodinated C6.5db and imaged using PET/CT. Radiotracer biodistribution was quantified using biopsied tumor and normal tissues. Potential competition between trastuzumab and C6.5db was examined in vitro by flow cytometry and co-immunoprecipitations. Results Biodistribution analysis of mice bearing xenografts with varying HER2 density revealed that the tumor uptake of 125I-C6.5db correlates with HER2 tumor density. In vitro competition experiments suggest that the C6.5db targets an epitope on HER2 that is distinct from that bound by trastuzumab. Treatment of SK-OV-3-tumored mice with trastuzumab for 3 d caused a 42% (P=0.002) decrease in tumor uptake of 125I-C6.5db. This is consistent with a dramatic decrease in the tumor PET signal of 124I-C6.5db after trastuzumab treatment. Furthermore, BT-474-tumored mice showed a ∼60% decrease (P=0.0026) in C6.5db uptake after 6 d of trastuzumab treatment. Immunohistochemistry of excised xenograft sections and in vitro flow cytometry revealed that the decreased C6.5db uptake upon trastuzumab treatment is not associated with HER2 downregulation. Conclusions These studies suggest that 124I-C6.5db-based imaging can be used to evaluate HER2 levels as a predictor of respone to HER2-directed therapies. PMID:21177408

  16. A HER2-specific Modified Fc Fragment (Fcab) Induces Antitumor Effects Through Degradation of HER2 and Apoptosis

    PubMed Central

    Leung, Kin-Mei; Batey, Sarah; Rowlands, Robert; Isaac, Samine J; Jones, Phil; Drewett, Victoria; Carvalho, Joana; Gaspar, Miguel; Weller, Sarah; Medcalf, Melanie; Wydro, Mateusz M; Pegram, Robert; Mudde, Geert C; Bauer, Anton; Moulder, Kevin; Woisetschläger, Max; Tuna, Mihriban; Haurum, John S; Sun, Haijun

    2015-01-01

    FS102 is a HER2-specific Fcab (Fc fragment with antigen binding), which binds HER2 with high affinity and recognizes an epitope that does not overlap with those of trastuzumab or pertuzumab. In tumor cells that express high levels of HER2, FS102 caused profound HER2 internalization and degradation leading to tumor cell apoptosis. The antitumor effect of FS102 in patient-derived xenografts (PDXs) correlated strongly with the HER2 amplification status of the tumors. Superior activity of FS102 over trastuzumab or the combination of trastuzumab and pertuzumab was observed in vitro and in vivo when the gene copy number of HER2 was equal to or exceeded 10 per cell based on quantitative polymerase chain reaction (qPCR). Thus, FS102 induced complete and sustained tumor regression in a significant proportion of HER2-high PDX tumor models. We hypothesize that the unique structure and/or epitope of FS102 enables the Fcab to internalize and degrade cell surface HER2 more efficiently than standard of care antibodies. In turn, increased depletion of HER2 commits the cells to apoptosis as a result of oncogene shock. FS102 has the potential of a biomarker-driven therapeutic that derives superior antitumor effects from a unique mechanism-of-action in tumor cells which are oncogenically addicted to the HER2 pathway due to overexpression. PMID:26234505

  17. Docosahexaenoic Acid Modulates a HER2-Associated Lipogenic Phenotype, Induces Apoptosis, and Increases Trastuzumab Action in HER2-Overexpressing Breast Carcinoma Cells

    PubMed Central

    Ravacci, Graziela Rosa; Brentani, Maria Mitzi; Tortelli, Tharcisio Citrângulo; Torrinhas, Raquel Suzana M. M.; Santos, Jéssica Reis; Logullo, Angela Flávia; Waitzberg, Dan Linetzky

    2015-01-01

    In breast cancer, lipid metabolic alterations have been recognized as potential oncogenic stimuli that may promote malignancy. To investigate whether the oncogenic nature of lipogenesis closely depends on the overexpression of HER2 protooncogene, the normal breast cell line, HB4a, was transfected with HER2 cDNA to obtain HER2-overexpressing HB4aC5.2 cells. Both cell lines were treated with trastuzumab and docosahexaenoic acid. HER2 overexpression was accompanied by an increase in the expression of lipogenic genes involved in uptake (CD36), transport (FABP4), and storage (DGAT) of exogenous fatty acids (FA), as well as increased activation of “de novo” FA synthesis (FASN). We further investigate whether this lipogenesis reprogramming might be regulated by mTOR/PPARγ pathway. Inhibition of the mTORC1 pathway markers, p70S6 K1, SREBP1, and LIPIN1, as well as an increase in DEPTOR expression (the main inhibitor of the mTOR) was detected in HB4aC5.2. Based on these results, a PPARγ selective antagonist, GW9662, was used to treat both cells lines, and the lipogenic genes remained overexpressed in the HB4aC5.2 but not HB4a cells. DHA treatment inhibited all lipogenic genes (except for FABP4) in both cell lines yet only induced death in the HB4aC5.2 cells, mainly when associated with trastuzumab. Neither trastuzumab nor GW9662 alone was able to induce cell death. In conclusion, oncogenic transformation of breast cells by HER2 overexpression may require a reprogramming of lipogenic genetic that is independent of mTORC1 pathway and PPARγ activity. This reprogramming was inhibited by DHA. PMID:26640797

  18. Super resolution imaging of HER2 gene amplification

    NASA Astrophysics Data System (ADS)

    Okada, Masaya; Kubo, Takuya; Masumoto, Kanako; Iwanaga, Shigeki

    2016-02-01

    HER2 positive breast cancer is currently examined by counting HER2 genes using fluorescence in situ hybridization (FISH)-stained breast carcinoma samples. In this research, two-dimensional super resolution fluorescence microscopy based on stochastic optical reconstruction microscopy (STORM), with a spatial resolution of approximately 20 nm in the lateral direction, was used to more precisely distinguish and count HER2 genes in a FISH-stained tissue section. Furthermore, by introducing double-helix point spread function (DH-PSF), an optical phase modulation technique, to super resolution microscopy, three-dimensional images were obtained of HER2 in a breast carcinoma sample approximately 4 μm thick.

  19. HER2 activation results in β-catenin-dependent changes in pulmonary epithelial permeability.

    PubMed

    Finigan, James H; Vasu, Vihas T; Thaikoottathil, Jyoti V; Mishra, Rangnath; Shatat, Mohammad A; Mason, Robert J; Kern, Jeffrey A

    2015-01-15

    The receptor tyrosine kinase human epidermal growth factor receptor-2 (HER2) is known to regulate pulmonary epithelial barrier function; however, the mechanisms behind this effect remain unidentified. We hypothesized that HER2 signaling alters the epithelial barrier through an interaction with the adherens junction (AJ) protein β-catenin, leading to dissolution of the AJ. In quiescent pulmonary epithelial cells, HER2 and β-catenin colocalized along the lateral intercellular junction. HER2 activation by the ligand neuregulin-1 was associated with tyrosine phosphorylation of β-catenin, dissociation of β-catenin from E-cadherin, and decreased E-cadherin-mediated cell adhesion. All effects were blocked with the HER2 inhibitor lapatinib. β-Catenin knockdown using shRNA significantly attenuated neuregulin-1-induced decreases in pulmonary epithelial resistance in vitro. Our data indicate that HER2 interacts with β-catenin, leading to dissolution of the AJ, decreased cell-cell adhesion, and disruption of the pulmonary epithelial barrier. PMID:25326580

  20. Novel Germline Mutation in the Transmembrane Domain of HER2 in Familial Lung Adenocarcinomas

    PubMed Central

    2014-01-01

    We encountered a family of Japanese descent in which multiple members developed lung cancer. Using whole-exome sequencing, we identified a novel germline mutation in the transmembrane domain of the human epidermal growth factor receptor 2 (HER2) gene (G660D). A novel somatic mutation (V659E) was also detected in the transmembrane domain of HER2 in one of 253 sporadic lung adenocarcinomas. Because the transmembrane domain of HER2 is considered to be responsible for the dimerization and subsequent activation of the HER family and downstream signaling pathways, we performed functional analyses of these HER2 mutants. Mutant HER2 G660D and V659E proteins were more stable than wild-type protein. Both the G660D and V659E mutants activated Akt. In addition, they activated p38, which is thought to promote cell proliferation in lung adenocarcinoma. Our findings strongly suggest that mutations in the transmembrane domain of HER2 may be oncogenic, causing hereditary and sporadic lung adenocarcinomas. PMID:24317180

  1. Novel germline mutation in the transmembrane domain of HER2 in familial lung adenocarcinomas.

    PubMed

    Yamamoto, Hiromasa; Higasa, Koichiro; Sakaguchi, Masakiyo; Shien, Kazuhiko; Soh, Junichi; Ichimura, Koichi; Furukawa, Masashi; Hashida, Shinsuke; Tsukuda, Kazunori; Takigawa, Nagio; Matsuo, Keitaro; Kiura, Katsuyuki; Miyoshi, Shinichiro; Matsuda, Fumihiko; Toyooka, Shinichi

    2014-01-01

    We encountered a family of Japanese descent in which multiple members developed lung cancer. Using whole-exome sequencing, we identified a novel germline mutation in the transmembrane domain of the human epidermal growth factor receptor 2 (HER2) gene (G660D). A novel somatic mutation (V659E) was also detected in the transmembrane domain of HER2 in one of 253 sporadic lung adenocarcinomas. Because the transmembrane domain of HER2 is considered to be responsible for the dimerization and subsequent activation of the HER family and downstream signaling pathways, we performed functional analyses of these HER2 mutants. Mutant HER2 G660D and V659E proteins were more stable than wild-type protein. Both the G660D and V659E mutants activated Akt. In addition, they activated p38, which is thought to promote cell proliferation in lung adenocarcinoma. Our findings strongly suggest that mutations in the transmembrane domain of HER2 may be oncogenic, causing hereditary and sporadic lung adenocarcinomas. PMID:24317180

  2. An Integrated Model of the Transcriptome of HER2-Positive Breast Cancer

    PubMed Central

    Kalari, Krishna R.; Necela, Brian M.; Tang, Xiaojia; Thompson, Kevin J.; Lau, Melissa; Eckel-Passow, Jeanette E.; Kachergus, Jennifer M.; Anderson, S. Keith; Sun, Zhifu; Baheti, Saurabh; Carr, Jennifer M.; Baker, Tiffany R.; Barman, Poulami; Radisky, Derek C.; Joseph, Richard W.; McLaughlin, Sarah A.; Chai, High-seng; Camille, Stephan; Rossell, David; Asmann, Yan W.; Thompson, E. Aubrey; Perez, Edith A.

    2013-01-01

    Our goal in these analyses was to use genomic features from a test set of primary breast tumors to build an integrated transcriptome landscape model that makes relevant hypothetical predictions about the biological and/or clinical behavior of HER2-positive breast cancer. We interrogated RNA-Seq data from benign breast lesions, ER+, triple negative, and HER2-positive tumors to identify 685 differentially expressed genes, 102 alternatively spliced genes, and 303 genes that expressed single nucleotide sequence variants (eSNVs) that were associated with the HER2-positive tumors in our survey panel. These features were integrated into a transcriptome landscape model that identified 12 highly interconnected genomic modules, each of which represents a cellular processes pathway that appears to define the genomic architecture of the HER2-positive tumors in our test set. The generality of the model was confirmed by the observation that several key pathways were enriched in HER2-positive TCGA breast tumors. The ability of this model to make relevant predictions about the biology of breast cancer cells was established by the observation that integrin signaling was linked to lapatinib sensitivity in vitro and strongly associated with risk of relapse in the NCCTG N9831 adjuvant trastuzumab clinical trial dataset. Additional modules from the HER2 transcriptome model, including ubiquitin-mediated proteolysis, TGF-beta signaling, RHO-family GTPase signaling, and M-phase progression, were linked to response to lapatinib and paclitaxel in vitro and/or risk of relapse in the N9831 dataset. These data indicate that an integrated transcriptome landscape model derived from a test set of HER2-positive breast tumors has potential for predicting outcome and for identifying novel potential therapeutic strategies for this breast cancer subtype. PMID:24223926

  3. Salivary expression of soluble HER2 in breast cancer patients with positive and negative HER2 status

    PubMed Central

    Laidi, Fatna; Bouziane, Amal; Lakhdar, Amina; Khabouze, Samira; Rhrab, Brahim; Zaoui, Fatima

    2014-01-01

    Background The aim of this study was to investigate the relationship between salivary concentration of the soluble fragment of the HER2 (human epidermal growth factor receptor) protein and its status in mammary tissues. Methods This case-control study was done in 27 breast cancer patients with no visible metastatic disease treated at the gynecology service, Maternity Souissi Hospital, Rabat, Morocco. Two groups were selected, ie, patients with positive and negative HER2 status in mammary tissue. The salivary HER2 protein concentration was assessed by enzyme-linked immunosorbent assay. The salivary HER2 concentration was compared between the HER2-positive and HER2-negative groups using the Mann-Whitney U test. A P-value <0.05 was considered to be statistically significant. Results No statistically significant difference in salivary HER2 protein expression was found between the case and control groups. There was also no significant difference in clinical characteristics according to positive and negative HER2 status (P>0.05), except for the progesterone hormone receptor which was statistically significant in both the case and control groups (P=0.047). Conclusion According to our data, salivary expression of the HER2 receptor may not be a reliable alternative to tissue assessment. PMID:25053886

  4. 2-Triazenoazaindoles: A novel class of triazenes inducing transcriptional down-regulation of EGFR and HER-2 in human pancreatic cancer cells

    PubMed Central

    KREUTZER, JAN N.; SALVADOR, ALESSIA; DIANA, PATRIZIA; CIRRINCIONE, GIROLAMO; VEDALDI, DANIELA; LITCHFIELD, DAVID W.; ISSINGER, OLAF-GEORG; GUERRA, BARBARA

    2012-01-01

    Pancreatic cancer is a complex malignancy arising from the accumulation of genetic and epigenetic defects in the affected cells. Standard chemotherapy for patients with advanced disease shows only modest effects and is associated with considerable toxicity. Overexpression or aberrant activation of members of the epidermal growth factor receptor tyrosine kinase family, which includes EGFR and HER-2, occurs frequently and is associated with multiple drug resistance and decreased patient survival. In this study, we have investigated the therapeutic potential of AS104, a novel compound of the triazene class, with potential inhibitory effects on EGFR. We found that treatment of cells with AS104 causes significant reduction of cell growth and metabolic activity in four human pancreatic cancer cell lines. Furthermore, we show that the AS104-mediated induction of apoptotic cell death is associated with stimulation of autophagy in a dose-dependent manner. Treatment of cells with AS104 results in significant down-regulation of EGFR and HER-2 expression and activity and subsequent inhibition of downstream signaling proteins. Quantitative RT-PCR analysis and assays with proteasome inhibitors revealed that AS104 regulates the expression of EGFR and HER-2 at the transcriptional level. These findings provide for the first time experimental evidence for efficacy of AS104 in the simultaneous transcriptional repression of EGFR and HER-2 genes and suggest that AS104 may have therapeutic potential in the treatment of pancreatic cancers that express high levels of the aforementioned receptor tyrosine kinases. PMID:22134789

  5. Development of automated brightfield double In Situ hybridization (BDISH) application for HER2 gene and chromosome 17 centromere (CEN 17) for breast carcinomas and an assay performance comparison to manual dual color HER2 fluorescence In Situ hybridization (FISH)

    PubMed Central

    Nitta, Hiroaki; Hauss-Wegrzyniak, Beatrice; Lehrkamp, Megan; Murillo, Adrian E; Gaire, Fabien; Farrell, Michael; Walk, Eric; Penault-Llorca, Frederique; Kurosumi, Masafumi; Dietel, Manfred; Wang, Lin; Loftus, Margaret; Pettay, James; Tubbs, Raymond R; Grogan, Thomas M

    2008-01-01

    Background Human epidermal growth factor receptor 2 (HER2) fluorescence in situ hybridization (FISH) is a quantitative assay for selecting breast cancer patients for trastuzumab therapy. However, current HER2 FISH procedures are labor intensive, manual methods that require skilled technologists and specialized fluorescence microscopy. Furthermore, FISH slides cannot be archived for long term storage and review. Our objective was to develop an automated brightfield double in situ hybridization (BDISH) application for HER2 gene and chromosome 17 centromere (CEN 17) and test the assay performance with dual color HER2 FISH evaluated breast carcinomas. Methods The BDISH assay was developed with the nick translated dinitrophenyl (DNP)-labeled HER2 DNA probe and DNP-labeled CEN 17 oligoprobe on the Ventana BenchMark® XT slide processing system. Detection of HER2 and CEN 17 signals was accomplished with the silver acetate, hydroquinone, and H2O2 reaction with horseradish peroxidase (HRP) and the fast red and naphthol phosphate reaction with alkaline phosphatise (AP), respectively. The BDISH specificity was optimized with formalin-fixed, paraffin-embedded xenograft tumors, MCF7 (non-amplified HER2 gene) and BT-474 (amplified HER2 gene). Then, the BDISH performance was evaluated with 94 routinely processed breast cancer tissues. Interpretation of HER2 and CEN 17 BDISH slides was conducted by 4 observers using a conventional brightfield microscope without oil immersion objectives. Results Sequential hybridization and signal detection for HER2 and CEN 17 ISH demonstrated both DNA targets in the same cells. HER2 signals were visualized as discrete black metallic silver dots while CEN 17 signals were detected as slightly larger red dots. Our study demonstrated a high consensus concordance between HER2 FISH and BDISH results of clinical breast carcinoma cases based on the historical scoring method (98.9%, Simple Kappa = 0.9736, 95% CI = 0.9222 – 1.0000) and the ASCO

  6. HER2-positive metastatic breast cancer: a changing scenario.

    PubMed

    Mustacchi, G; Biganzoli, L; Pronzato, P; Montemurro, F; Dambrosio, M; Minelli, M; Molteni, L; Scaltriti, L

    2015-07-01

    Adjuvant trastuzumab (AT) dramatically improved HER2-positive breast cancer prognosis. Relapsed disease after AT has different patterns and information is available from observational studies. In this Review Chemotherapy regimens combined to anti-HER2 blockade are discussed, focusing in particular the role of anthracyclines, taxanes and capecitabine. The use of trastuzumab beyond progression and the role of other anti-HER2 agents like lapatinib, pertuzumab and T-DM1 are explored, as also dual blockade and in trastuzumab resistant Patients. Metastatic "de novo" HER2 Luminal (co-expression of HER2 and hormone receptors) Patients are eligible for anastrozole and trastuzumab but if pretreated with trastuzumab they are also eligible for lapatinib and letrozole. In any case endocrine treatment plays a complementary role to chemotherapy which remains pivotal. The last topic explored is treatment options for patients with brain metastases where both trastuzumab given concurrent with radiotherapy or lapatinib and capecitabine appear as potentially active. PMID:25748080

  7. Combination therapy of RY10-4 with the γ-secretase inhibitor DAPT shows promise in treating HER2-amplified breast cancer.

    PubMed

    Su, Feng; Zhu, Shilin; Ruan, Jinlan; Muftuoglu, Yagmur; Zhang, Longbo; Yuan, Qianying

    2016-01-26

    RY10-4, a novel protoapigenone analog, shows potent cytotoxicity against human breast cancer cells. However, breast cancer cell lines overexpressing human epidermal growth factor receptor 2 (HER2), SKBR3 and BT474, showed less sensitivity to RY10-4 when compared to breast cancer cells lines expressing lower levels of HER2, such as MDA-MB-231 and MCF-7 cells. This was associated with aberrant hyperactivity in Notch signaling in cells treated with RY10-4, since treatment with RY10-4 causes an increase in Notch activity by 2-to3.5-fold in SKBR3 and BT474 cell lines. The increase in activity was abrogated with a γ-secretase inhibitor, DAPT, or with Notch1 small-interfering RNA (si-Notch1). Cell proliferation was inhibited more effectively by RY10-4 plus DAPT or si-Notch1 than either agent alone. RY10-4 plus DAPT increases apoptosis in both HER2-overexpressing cell lines by two-fold compared to RY10-4 alone, while DAPT alone has no significant effects on apoptosis. In addition, we previously found RY10-4 could inhibit tumor growth through the PI3K/AKT pathway. Here we report that the combination of RY10-4 and DAPT exhibit additive suppression on AKT phosphorylation, contributing to the anti-cancer effects. In an animal model, this combination therapy inhibits the growth of SKBR3 tumor xenografts in nude mice to a greater extent than treatment with either reagent alone. These results indicate that the aberrant activation of Notch signaling impedes the inhibitory effect of RY10-4 on HER2-amplified cell proliferation. Furthermore, these adverse effects can be prevented by treatment combining RY10-4 with a Notch pathway inhibitor. PMID:26716652

  8. Combination therapy of RY10-4 with the γ-secretase inhibitor DAPT shows promise in treating HER2-amplified breast cancer

    PubMed Central

    Su, Feng; Zhu, Shilin; Ruan, Jinlan; Muftuoglu, Yagmur; Zhang, Longbo; Yuan, Qianying

    2016-01-01

    RY10-4, a novel protoapigenone analog, shows potent cytotoxicity against human breast cancer cells. However, breast cancer cell lines overexpressing human epidermal growth factor receptor 2 (HER2), SKBR3 and BT474, showed less sensitivity to RY10-4 when compared to breast cancer cells lines expressing lower levels of HER2, such as MDA-MB-231 and MCF-7 cells. This was associated with aberrant hyperactivity in Notch signaling in cells treated with RY10-4, since treatment with RY10-4 causes an increase in Notch activity by 2-to3.5-fold in SKBR3 and BT474 cell lines. The increase in activity was abrogated with a γ-secretase inhibitor, DAPT, or with Notch1 small-interfering RNA (si-Notch1). Cell proliferation was inhibited more effectively by RY10-4 plus DAPT or si-Notch1 than either agent alone. RY10-4 plus DAPT increases apoptosis in both HER2-overexpressing cell lines by two-fold compared to RY10-4 alone, while DAPT alone has no significant effects on apoptosis. In addition, we previously found RY10-4 could inhibit tumor growth through the PI3K/AKT pathway. Here we report that the combination of RY10-4 and DAPT exhibit additive suppression on AKT phosphorylation, contributing to the anti-cancer effects. In an animal model, this combination therapy inhibits the growth of SKBR3 tumor xenografts in nude mice to a greater extent than treatment with either reagent alone. These results indicate that the aberrant activation of Notch signaling impedes the inhibitory effect of RY10-4 on HER2-amplified cell proliferation. Furthermore, these adverse effects can be prevented by treatment combining RY10-4 with a Notch pathway inhibitor. PMID:26716652

  9. Antitumor activity of phenethyl isothiocyanate in HER2-positive breast cancer models

    PubMed Central

    2012-01-01

    Background HER2 is an oncogene, expression of which leads to poor prognosis in 30% of breast cancer patients. Although trastuzumab is apparently an effective therapy against HER2-positive tumors, its systemic toxicity and resistance in the majority of patients restricts its applicability. In this study we evaluated the effects of phenethyl isothiocyanate (PEITC) in HER2-positive breast cancer cells. Methods MDA-MB-231 and MCF-7 breast cancer cells stably transfected with HER2 (high HER2 (HH)) were used in this study. The effect of PEITC was evaluated using cytotoxicity and apoptosis assay in these syngeneic cells. Western blotting was used to delineate HER2 signaling. SCID/NOD mice were implanted with MDA-MB-231 (HH) xenografts. Results Our results show that treatment of MDA-MB-231 and MCF-7 cells with varying concentrations of PEITC for 24 h extensively reduced the survival of the cells with a 50% inhibitory concentration (IC50) of 8 μM in MDA-MB-231 and 14 μM in MCF-7 cells. PEITC treatment substantially decreased the expression of HER2, epidermal growth factor receptor (EGFR) and phosphorylation of signal transducer and activator of transcription 3 (STAT3) at Tyr-705. The expression of BCL-2-associated × (BAX) and BIM proteins were increased, whereas the levels of B cell lymphoma-extra large (BCL-XL) and X-linked inhibitor of apoptosis protein (XIAP) were significantly decreased in both the cell lines in response to PEITC treatment. Substantial cleavage of caspase 3 and poly-ADP ribose polymerase (PARP) were associated with PEITC-mediated apoptosis in MDA-MB-231 and MCF-7 cells. Notably, transient silencing of HER2 decreased and overexpressing HER2 increased the effects of PEITC. Furthermore, reactive oxygen species (ROS) generation, mitochondrial depolarization and apoptosis by PEITC treatment were much higher in breast cancer cells expressing higher levels of HER2 (HH) as compared to parent cell lines. The IC50 of PEITC following 24 h of treatment was

  10. Combining epitope-distinct antibodies to HER2: cooperative inhibitory effects on invasive growth

    PubMed Central

    Emde, A.; Pradeep, C-R.; Ferraro, DA.; Ben-Chetrit, N.; Sela, M.; Ribba, B.; Kam, Z.; Yarden, Y.

    2013-01-01

    Monoclonal antibodies (mAbs) to HER2 are currently used to treat breast cancer, but low clinical efficacy, along with primary and acquired resistance to therapy, commonly limit clinical applications. We previously reported that combinations of antibodies directed at non-overlapping epitopes of HER2 are endowed with enhanced antitumor effects, probably due to accelerated receptor degradation. Here, we extend these observations to three-dimensional mammary cell models, and compare the effects of single mAbs with the effects of antibody combinations. Collectively, our in vitro assays and computational image analyses indicate that combining mAbs against different epitopes of HER2 better inhibits invasive growth. Importantly, while growth factors are able to reduce intraluminal apoptosis and induce an invasive phenotype, combinations of mAbs better than single mAbs can reverse the growth factor-induced phenotypes of HER2-overexpressing spheroids. In conclusion, our studies propose that mAb combinations negate the biological effects of growth factors on invasive growth of HER2-overexpressing cells. Hence, combining mAbs offers a therapeutic strategy, potentially able to enhance clinical efficacy of existing antireceptor immuno-therapeutics. PMID:21132012

  11. Xeno-Klotho Inhibits Parathyroid Hormone Signaling.

    PubMed

    Takenaka, Tsuneo; Inoue, Tsutomu; Miyazaki, Takashi; Hayashi, Matsuhiko; Suzuki, Hiromichi

    2016-02-01

    Although fibroblast growth factor (FGF) 23 was recently identified as a phosphatonin that influences vitamin D metabolism, the underlying signaling mechanisms remain unclear. FGF23 elevates the renal levels of membrane-associated klotho as well as soluble klotho. Klotho is expressed on distal tubules. Upon enzymatic cleavage, soluble klotho is released into the renal interstitial space and then into the systemic circulation. The expression of 25-hydroxyvitamin D3 1α-hydroxylase (1-OH) on proximal tubular cells is controlled by parathyroid hormone (PTH). Klotho binds to various membrane proteins to alter their function. Here, the interaction between the PTH receptor and klotho was studied using various approaches, including immunoprecipitation, in vitro cell culture, and in vivo animal experiments. Immunoprecipitation studies demonstrate, for the first time, that recombinant human klotho protein interacts with human PTH receptors to inhibit the binding of human PTH. Furthermore, when applied to human proximal tubular cells, recombinant human klotho suppresses PTH-stimulated generation of inositol trisphosphate in vitro. Moreover, PTH-induced increase of cyclic AMP secretion and 1α,25-dihydroxyvitamin D3 (1,25VD) was attenuated by recombinant human klotho in vivo. In addition, recombinant human klotho inhibits the expression of 1-OH by PTH both in vitro and in vivo. These results suggest that free klotho mediates the FGF23-induced inhibition of 1,25VD synthesis. © 2015 American Society for Bone and Mineral Research. PMID:26287968

  12. Preliminary results of centralized HER2 testing in ductal carcinoma in situ (DCIS): NSABP B-43

    PubMed Central

    Siziopikou, Kalliopi P.; Anderson, Stewart J.; Cobleigh, Melody A.; Arthur, Douglas W.; Zheng, Ping; Mamounas, Eleftherios P.; Pajon, Eduardo R.; Behrens, Robert J.; Eakle, Janice F.; Leasure, Nick C.; Atkins, James N.; Polikoff, Jonathan A.; Seay, Thomas E.; McCaskill-Stevens, Worta J.; Rabinovitch, Rachel; Costantino, Joseph P.; Wolmark, Norman

    2016-01-01

    NSABP B-43 is the first prospective, randomized phase III multi-institution clinical trial targeting high-risk, HER2-positive DCIS. It compares whole breast irradiation alone with WBI given concurrently with trastuzumab in women with HER2-positive DCIS treated by lumpectomy. The primary aim is to determine if trastuzumab plus radiation will reduce in-breast tumor recurrence. HER2-positive DCIS was previously estimated at >50 %, occurring primarily in ER-negative, comedo-type DCIS of high nuclear grade. There has been no documented centralized multi-institutional HER2 analysis of DCIS. NSABP B-43 provides a unique opportunity to evaluate this in a large cohort of DCIS patients. Patients undergoing lumpectomy for DCIS without evidence of an invasive component are eligible. A central review of each patient’s pure DCIS lesion is carried out by immunohistochemistry analysis. If the lesion is 2+, FISH analysis is performed. Patients whose tumors are HER2 3+ or FISH-positive are randomly assigned to receive two doses of trastuzumab during WBI or WBI alone. NSABP B-43 opened 11/9/08. As of 7/31/2013, 5,861 patients have had specimens received centrally, and 5,645 of those had analyzable blocks; 1,969 (34.9 %) were HER2 positive. A total of 1,428 patients have been accrued, 1,137 (79.6 %) of whom have follow-up information. The average follow-up time for the 1,137 patients is 23.3 months. No grade 4 or 5 toxicity has been observed. In NSABP B-43 the HER2-positive rate for pure DCIS among patients undergoing breast-preserving surgery is 34.9 %, lower than the previously reported rate. No trastuzumab-related safety signals have been observed. Interest in this trial has been robust. PMID:24202240

  13. Preliminary results of centralized HER2 testing in ductal carcinoma in situ (DCIS): NSABP B-43.

    PubMed

    Siziopikou, Kalliopi P; Anderson, Stewart J; Cobleigh, Melody A; Julian, Thomas B; Arthur, Douglas W; Zheng, Ping; Mamounas, Eleftherios P; Pajon, Eduardo R; Behrens, Robert J; Eakle, Janice F; Leasure, Nick C; Atkins, James N; Polikoff, Jonathan A; Seay, Thomas E; McCaskill-Stevens, Worta J; Rabinovitch, Rachel; Costantino, Joseph P; Wolmark, Norman

    2013-11-01

    NSABP B-43 is the first prospective, randomized phase III multi-institution clinical trial targeting high-risk, HER2-positive DCIS. It compares whole breast irradiation alone with WBI given concurrently with trastuzumab in women with HER2-positive DCIS treated by lumpectomy. The primary aim is to determine if trastuzumab plus radiation will reduce in-breast tumor recurrence. HER2-positive DCIS was previously estimated at >50 %, occurring primarily in ER-negative, comedo-type DCIS of high nuclear grade. There has been no documented centralized multi-institutional HER2 analysis of DCIS. NSABP B-43 provides a unique opportunity to evaluate this in a large cohort of DCIS patients. Patients undergoing lumpectomy for DCIS without evidence of an invasive component are eligible. A central review of each patient's pure DCIS lesion is carried out by immunohistochemistry analysis. If the lesion is 2+, FISH analysis is performed. Patients whose tumors are HER2 3+ or FISH-positive are randomly assigned to receive two doses of trastuzumab during WBI or WBI alone. NSABP B-43 opened 11/9/08. As of 7/31/2013, 5,861 patients have had specimens received centrally, and 5,645 of those had analyzable blocks; 1,969 (34.9 %) were HER2 positive. A total of 1,428 patients have been accrued, 1,137 (79.6 %) of whom have follow-up information. The average follow-up time for the 1,137 patients is 23.3 months. No grade 4 or 5 toxicity has been observed. In NSABP B-43 the HER2-positive rate for pure DCIS among patients undergoing breast-preserving surgery is 34.9 %, lower than the previously reported rate. No trastuzumab-related safety signals have been observed. Interest in this trial has been robust. PMID:24202240

  14. HER-2 Positive Breast Cancer - a Mini-Review.

    PubMed

    Asif, Hafiz Muhammad; Sultana, Sabira; Ahmed, Saeed; Akhtar, Naheed; Tariq, Muhammad

    2016-01-01

    Breast cancer is one of among all cancers with increased incidence, high mortality rate, and high economic and social costs. The the most common type of cancer among females worldwide, breast cancer is actually the uncontrolled proliferation of cells which attain malignancy. Recently it has shown that breast cancer contributes 11% among all types of cancer diagnosed globally on an annual basis and it is one of the leading causes of death among women. The human epidermal growth factor receptor 2 (HER-2) is a receptor tyrosine-protein kinase erbB-2 normally involved in the proliferation and division of breast cells. In some abnormal cases the HER2 gene does not work correctly and makes too many copies of itself. HER2-positive (HER2+) breast cancers constitute an aggressive type of breast cancer and tend to grow faster and are more likely to spread. However, therapies that specifically target HER2, such as Herceptin® (traztuzumab), are very effective. HER2 targeted therapies, has significantly improved the therapeutic outcome for patients with HER2 positive breast cancer. PMID:27221828

  15. Genetic variants in the HER2 gene: Influence on HER2 overexpression and loss of heterozygosity in breast cancer.

    PubMed

    Cresti, Nicola; Lee, Joanne; Rourke, Emma; Televantou, Despina; Jamieson, David; Verrill, Mark; Boddy, Alan V

    2016-03-01

    Human epidermal growth factor receptor 2 (HER2) overexpression in breast cancer is an indicator of poor prognosis and is the pre-requisite for treatment with the agents targeting this member of the epidermal growth factor receptor family. In order to determine the influence of these common single-nucleotide polymorphisms (SNPs) in the HER2 gene, genomic DNA was obtained from 361 patients with breast cancer, aged between 29 and 82 years. Samples of tumour tissue were obtained from 241 (66%) patients and material for extraction of DNA is isolated from surrounding normal tissue by laser capture microdissection. Genotyping was performed using the Taqman fluorogenic 5' nuclease assay. Of the 360 patients with definitive determination of HER2 status, 49% were positive. The Ile655Val SNP had no influence on the frequency of HER2 expression. However, the proline allele of the Ala1170Pro SNP was associated with a higher frequency of HER2 overexpression (56% versus 43%, p = 0.015). Where the germline genotype was homozygous, the tumour genotype was identical in every case and for both SNPs. In HER2-positive tumours, heterozygosity was maintained in only 15% and 18% of the Ile655Val and Ala1170Pro SNPs, respectively. This was lower than in the HER2-negative tumours (46% and 43%, respectively). Normal breast tissue (n = 23) retained the germline genotype in all but one case. The underlying link between the Ala1170Pro SNP and HER2 positivity is not known, nor is the significance of HER2 overexpression and loss of heterozygosity in breast cancer. However, these results illustrate the complexity of HER2 genotype and overexpression in this disease. PMID:26773371

  16. Biologic and therapeutic role of HER2 in cancer.

    PubMed

    Ménard, Sylvie; Pupa, Serenella Marja; Campiglio, Manuela; Tagliabue, Elda

    2003-09-29

    Overexpression of the human epidermal growth factor-2 (HER2) oncogene in human breast carcinomas has been associated with a more aggressive course of disease. The reason for this association is still unclear, although it has been suggested to rest in increased proliferation, vessel formation, and/or invasiveness. Alternatively, prognosis may not be directly related to the presence of the oncoprotein on the cell membrane, but instead to the breast carcinoma subset identified by HER2 overexpression and characterized by a peculiar gene expression profile. HER2 has also been associated with sensitivity to anthracyclins and resistance to endocrine therapy, suggesting that tyrosine kinase receptor and hormone receptor pathways represent two major proliferation pathways exclusively active in breast carcinomas, one sensitive to chemotherapeutic drugs and the other to antiestrogens. HER2 currently represents one of the most appropriate targets for specific therapy. Indeed, trastuzumab, a monoclonal antibody directed against the extracellular domain of HER2, is therapeutically active in HER2-positive breast carcinomas. However, a consistent number of HER2-positive tumors is not responsive to HER2-driven therapy, indicating the need for a better understanding of the mechanism of action of this new biological drug in vivo. While preclinical studies suggest antibody-dependent cell cytotoxicity as the major mechanism, determination of NK activity at the time of treatment remains mandatory, especially in patients treated with immunosuppressive drugs. The efficacy of prophylactic vaccination has been fully demonstrated in preclinical models, whereas ongoing studies of active immunotherapy using a variety of vaccination regimens against HER2 in tumor-bearing mice and patients have met with only moderate success. PMID:14528282

  17. ATM: An unexpected tumor-promoting factor in HER2-expressing tumors

    PubMed Central

    Stagni, Venturina; Oropallo, Veronica; Barilà, Daniela

    2016-01-01

    ABSTRACT ATM kinase is a gatekeeper of genome stability. However, its role in several other signaling pathways suggests that it might not always act as a tumor suppressor. Here, we discuss recent data that unveil a function of ATM as a tumor promoter in HER2-positive breast cancer. PMID:27308589

  18. Antitumor effect of afatinib, as a human epidermal growth factor receptor 2-targeted therapy, in lung cancers harboring HER2 oncogene alterations.

    PubMed

    Suzawa, Ken; Toyooka, Shinichi; Sakaguchi, Masakiyo; Morita, Mizuki; Yamamoto, Hiromasa; Tomida, Shuta; Ohtsuka, Tomoaki; Watanabe, Mototsugu; Hashida, Shinsuke; Maki, Yuho; Soh, Junichi; Asano, Hiroaki; Tsukuda, Kazunori; Miyoshi, Shinichiro

    2016-01-01

    Human epidermal growth factor receptor 2 (HER2) is a member of the HER family of proteins containing four receptor tyrosine kinases. It plays an important role in the pathogenesis of certain human cancers. In non-small-cell lung cancer (NSCLC), HER2 amplification or mutations have been reported. However, little is known about the benefit of HER2-targeted therapy for NSCLCs harboring HER2 alterations. In this study, we investigated the antitumor effect of afatinib, an irreversible epidermal growth factor receptor (EGFR)-HER2 dual inhibitor, in lung cancers harboring HER2 oncogene alterations, including novel HER2 mutations in the transmembrane domain, which we recently identified. Normal bronchial epithelial cells, BEAS-2B, ectopically overexpressing wild-type HER2 or mutants (A775insYVMA, G776VC, G776LC, P780insGSP, V659E, and G660D) showed constitutive autophosphorylation of HER2 and activation of downstream signaling. They were sensitive to afatinib, but insensitive to gefitinib. Furthermore, we examined the antitumor activity of afatinib and gefitinib in several NSCLC cell lines, and investigated the association between their genetic alterations and sensitivity to afatinib treatment. In HER2-altered NSCLC cells (H2170, Calu-3, and H1781), afatinib downregulated the phosphorylation of HER2 and EGFR as well as their downstream signaling, and induced an antiproliferative effect through G1 arrest and apoptotic cell death. In contrast, HER2- or EGFR-non-dependent NSCLC cells were insensitive to afatinib. In addition, these effects were confirmed in vivo by using a xenograft mouse model of HER2-altered lung cancer cells. Our results suggest that afatinib is a therapeutic option as a HER2-targeted therapy for NSCLC harboring HER2 amplification or mutations. PMID:26545934

  19. Is it necessary to evaluate nuclei in HER2 FISH evaluation?

    PubMed

    López, Carlos; Tomás, Barbara; Korzynska, Anna; Bosch, Ramón; Salvadó, Maria T; Llobera, Montserrat; Garcia-Rojo, Marcial; Alvaro, Tomás; Jaén, Joaquín; Lejeune, Marylène

    2013-01-01

    A new method that simplifies the evaluation of the traditional HER2 fluorescence in situ hybridization (FISH) evaluation in breast cancer was proposed. HER2 status was evaluated in digital images (DIs) captured from 423 invasive breast cancer stained sections. All centromeric/CEP17 and HER2 gene signals obtained from separated stacked DIs were manually counted on the screen. The global ratios were compared with the traditional FISH evaluation and the immunohistochemical status. The 2 FISH scores were convergent in 96.93% of cases, showing an "almost perfect" agreement with a weighted k of 0.956 (95% confidence interval, 0.928-0.985). The new method evaluates at least 3 times more nuclei than traditional methods and also has an almost perfect agreement with the immunohistochemical scores. The proposed enhanced method substantially improves HER2 FISH assessment in breast cancer biopsy specimens because the evaluation of HER2/CEP17 copy numbers is more representative, easier, and faster than the conventional method. PMID:23270898

  20. Detection of HER2 breast cancer biomarker using the optofluidic ring resonator biosensor

    NASA Astrophysics Data System (ADS)

    Gohring, John T.; Dale, Paul S.; Fan, Xudong

    2010-04-01

    In this work, we describe a novel approach for detecting the HER2/neu extra-cellular domain (ECD) protein in human serum samples using the opto-fluidic ring resonator (OFRR). OFRR sensing technology that incorporates microfluidics and optical sensing methods to achieve rapid label free detection in a small and low cost platform. In this study, HER2 proteins were spiked in PBS running buffer and serum at varying concentrations. Concentrations of the HER2 protein were adjusted in serum to levels typical of breast cancer patients that show over-expression of this particular beast cancer biomarker. The OFRR was modified with a biologically functional layer to efficiently capture the HER2 biomarker and produce a sensing signal through interaction with the evanescent field of the optical resonator. Results show effective capture of HER2 at medically relevant concentrations in serum and was achieved for concentrations as low as 13 ng/mL and ranged to above 100 ng/mL. This work will lead to a device that can be used as a tool for monitoring disease progression in a low cost sensing setup.

  1. Neratinib in HER-2-positive breast cancer: results to date and clinical usefulness

    PubMed Central

    Chan, Arlene

    2016-01-01

    The management of HER-2-positive breast cancer has improved significantly with the use of targeted agents to the HER-2 signaling pathway. Despite the improved survival achieved with the use of trastuzumab and chemotherapy in both the adjuvant and metastatic setting, patients may still recur or progress; whilst preclinical data demonstrate that these cancer cells remain addicted to the HER-2 oncogene. Neratinib, an oral small molecule tyrosine-kinase inhibitor has efficacy in the metastatic and adjuvant setting of patients who have previously received trastuzumab-based treatment. Diarrhea, being a class effect of tyrosine-kinase inhibitor, is the most common side effect seen following neratinib administration, but recent data suggests that a prophylactic loperamide regimen can reduce the incidence of grade 3 diarrhea. Phase I through to III clinical trials of neratinib will be reviewed, with discussion of the postulated mechanism underlying diarrheal events and its management. PMID:27583026

  2. Neratinib in HER-2-positive breast cancer: results to date and clinical usefulness.

    PubMed

    Chan, Arlene

    2016-09-01

    The management of HER-2-positive breast cancer has improved significantly with the use of targeted agents to the HER-2 signaling pathway. Despite the improved survival achieved with the use of trastuzumab and chemotherapy in both the adjuvant and metastatic setting, patients may still recur or progress; whilst preclinical data demonstrate that these cancer cells remain addicted to the HER-2 oncogene. Neratinib, an oral small molecule tyrosine-kinase inhibitor has efficacy in the metastatic and adjuvant setting of patients who have previously received trastuzumab-based treatment. Diarrhea, being a class effect of tyrosine-kinase inhibitor, is the most common side effect seen following neratinib administration, but recent data suggests that a prophylactic loperamide regimen can reduce the incidence of grade 3 diarrhea. Phase I through to III clinical trials of neratinib will be reviewed, with discussion of the postulated mechanism underlying diarrheal events and its management. PMID:27583026

  3. Application of NIR fluorescent markers to quantify expression level of HER2 receptors in carcinomas in vivo

    NASA Astrophysics Data System (ADS)

    Chernomordik, Victor; Hassan, Moinuddin; Lee, Sang Bong; Zielinski, Rafal; Capala, Jacek; Gandjbakhche, Amir

    2010-02-01

    HER2 overexpression has been associated with a poor prognosis and resistance to therapy in breast cancer patients. However, quantitative estimates of this important characteristic have been limited to ex vivo ELISA essays of tissue biopsies and/or PET. We develop a novel approach in optical imaging, involving specific probes, not interfering with the binding of the therapeutic agents, thus, excluding competition between therapy and imaging. Affibody-based molecular probes seem to be ideal for in vivo analysis of HER2 receptors using near-infrared optical imaging. Fluorescence intensity distributions, originating from specific markers in the tumor area, can reveal the corresponding fluorophore concentration. We use temporal changes of the signal from a contrast agent, conjugated with HER2-specific Affibody as a signature to monitor in vivo the receptors status in mice with different HER2 over-expressed tumor models. Kinetic model, incorporating saturation of the bound ligands in the tumor area due to HER2 receptor concentration, is suggested to analyze relationship between tumor cell characteristics, i.e., HER2 overexpression, obtained by traditional ("golden standard") ex vivo methods (ELISA), and parameters, estimated from the series of images in vivo. Observed correlation between these parameters and HER2 overexpression substantiates application of our approach to quantify HER2 concentration in vivo.

  4. SU-E-I-81: Targeting of HER2-Expressing Tumors with Dual PET-MR Imaging Probes

    SciTech Connect

    Xu, P; Peng, Y; Sun, M; Yang, X

    2015-06-15

    Purpose: The detection of human epidermal growth factor receptor type 2 (HER2) expression in malignant tumors provides important information influencing patient management. Radionuclide in vivo imaging of HER2 may permit the detection of HER2 in both primary tumors and metastases by a single noninvasive procedure. Trastuzumab, effective in about 15 % of women with breast cancer, downregulates signalling through the Akt/PI3K and MAPK pathways.These pathways modulate metabolism which can be monitored by positron emission tomography (PET) and magnetic resonance imaging (MRI). Methods: The relationship between response of HER2 overexpressing tumours and changes in imaging PET or SPECT and MRI will be examined by a integrated bimodal imaging probe.Small (7 kDa) high-affinity anti-HER2 Affibody molecules and KCCYSL targeting peptide may be suitable tracers for visualization of HER2-expressing tumors. Peptide-conjugated iron oxide nanoparticles (Fe3O4 NPs) as MRI imaging and CB-TE2A as PET imaging are integrated into a single synthetic molecule in the HER2 positive cancer. Results: One of targeted contrast bimodal imaging probe agents was synthesized and evaluated to target HER2-expressing tumors in a HER2 positive rat model. We will report the newest results regarding the development of bimodal imaging probes. Conclusion: The preliminary results of the bimodal imaging probe presents high correlation of MRI signal and PET imaging intensity in vivo. This unique feature can hardly be obtained by single model contrast agents. It is envisioned that this bimodal agents can hold great potential for accurate detection of HER2-expressing tumors which are critical for clinical management of the disease.

  5. EGFR, HER-2 and KRAS in canine gastric epithelial tumors: a potential human model?

    PubMed

    Terragni, Rossella; Casadei Gardini, Andrea; Sabattini, Silvia; Bettini, Giuliano; Amadori, Dino; Talamonti, Chiara; Vignoli, Massimo; Capelli, Laura; Saunders, Jimmy H; Ricci, Marianna; Ricci, Marianna; Ulivi, Paola; Ulivi, Paola

    2014-01-01

    Epidermal growth factor receptor (EGFR or HER-1) and its analog c-erbB-2 (HER-2) are protein tyrosine kinases correlated with prognosis and response to therapy in a variety of human cancers. KRAS mediates the transduction of signals between EGFR and the nucleus, and its mutation has been identified as a predictor of resistance to anti-EGFR drugs. In human oncology, the importance of the EGFR/HER-2/KRAS signalling pathway in gastric cancer is well established, and HER-2 testing is required before initiating therapy. Conversely, this pathway has never been investigated in canine gastric tumours. A total of 19 canine gastric epithelial neoplasms (5 adenomas and 14 carcinomas) were retrospectively evaluated for EGFR/HER-2 immunohistochemical expression and KRAS mutational status. Five (35.7%) carcinomas were classified as intestinal-type and 9 (64.3%) as diffuse-type. EGFR was overexpressed (≥ 1+) in 8 (42.1%) cases and HER-2 (3+) in 11 (57.9%) cases, regardless of tumour location or biological behaviour. The percentage of EGFR-positive tumours was significantly higher in the intestinal-type (80%) than in the diffuse-type (11.1%, p = 0.023). KRAS gene was wild type in 18 cases, whereas one mucinous carcinoma harboured a point mutation at codon 12 (G12R). EGFR and HER-2 may be promising prognostic and therapeutic targets in canine gastric epithelial neoplasms. The potential presence of KRAS mutation should be taken into account as a possible mechanism of drug resistance. Further studies are necessary to evaluate the role of dog as a model for human gastric cancer. PMID:24454858

  6. EGFR, HER-2 and KRAS in Canine Gastric Epithelial Tumors: A Potential Human Model?

    PubMed Central

    Bettini, Giuliano; Amadori, Dino; Talamonti, Chiara; Vignoli, Massimo; Capelli, Laura; Saunders, Jimmy H.; Ricci, Marianna; Ulivi, Paola

    2014-01-01

    Epidermal growth factor receptor (EGFR or HER-1) and its analog c-erbB-2 (HER-2) are protein tyrosine kinases correlated with prognosis and response to therapy in a variety of human cancers. KRAS mediates the transduction of signals between EGFR and the nucleus, and its mutation has been identified as a predictor of resistance to anti-EGFR drugs. In human oncology, the importance of the EGFR/HER-2/KRAS signalling pathway in gastric cancer is well established, and HER-2 testing is required before initiating therapy. Conversely, this pathway has never been investigated in canine gastric tumours. A total of 19 canine gastric epithelial neoplasms (5 adenomas and 14 carcinomas) were retrospectively evaluated for EGFR/HER-2 immunohistochemical expression and KRAS mutational status. Five (35.7%) carcinomas were classified as intestinal-type and 9 (64.3%) as diffuse-type. EGFR was overexpressed (≥1+) in 8 (42.1%) cases and HER-2 (3+) in 11 (57.9%) cases, regardless of tumour location or biological behaviour. The percentage of EGFR-positive tumours was significantly higher in the intestinal-type (80%) than in the diffuse-type (11.1%, p = 0.023). KRAS gene was wild type in 18 cases, whereas one mucinous carcinoma harboured a point mutation at codon 12 (G12R). EGFR and HER-2 may be promising prognostic and therapeutic targets in canine gastric epithelial neoplasms. The potential presence of KRAS mutation should be taken into account as a possible mechanism of drug resistance. Further studies are necessary to evaluate the role of dog as a model for human gastric cancer. PMID:24454858

  7. HER-2/neu oncogene expression and proliferation in breast cancers.

    PubMed Central

    Bacus, S. S.; Ruby, S. G.; Weinberg, D. S.; Chin, D.; Ortiz, R.; Bacus, J. W.

    1990-01-01

    Amplification of the HER-2/neu proto-oncogene in breast cancer has been reported to correlate with poor patient prognosis. The proliferation, or growth fraction, of cells has also been shown to be of prognostic importance in breast cancer. A study was conducted to evaluate the correlation between HER-2/neu gene expression and proliferation in breast cancer. Quantitative immunohistochemical methods for the detection of the HER-2/neu protein expression and for assessing the proliferation fraction on frozen sections of tumor cells were used. The detection of epidermal growth factor receptor (EGFR) along with quantitative DNA ploidy analysis, also was performed on the same breast cancers. The results indicated two subgroups of invasive ductal carcinoma; 1) HER-2/neu overexpressing cases that were negative for EGFR expression and had low proliferation fraction, and a tetraploid DNA pattern (22 cases), and 2) other combinations of HER-2/neu expression and EGFR expression, with a high proliferation fraction and an aneuploid DNA pattern (38 cases). Eight cases of carcinoma in situ were positive for HER-2/neu overexpression and negative for EGFR expression, and had a high proliferation fraction and a tetraploid DNA pattern. Twenty-six cases of low-grade carcinoma exhibited low proliferation and a diploid DNA pattern. Images Figure 1 Figure 2 PMID:1973597

  8. TARGETING THE MUC1-C ONCOPROTEIN DOWNREGULATES HER2 ACTIVATION AND ABROGATES TRASTUZUMAB RESISTANCE IN BREAST CANCER CELLS

    PubMed Central

    Raina, Deepak; Uchida, Yasumitsu; Kharbanda, Akriti; Rajabi, Hasan; Panchamoorthy, Govind; Jin, Caining; Kharbanda, Surender; Scaltriti, Maurizio; Baselga, Jose; Kufe, Donald

    2014-01-01

    Patients with HER2 positive breast cancer often exhibit intrinsic or acquired resistance to trastuzumab treatment. The transmembrane MUC1-C oncoprotein is aberrantly overexpressed in breast cancer cells and associates with HER2. The present studies demonstrate that silencing MUC1-C in HER2-overexpressing SKBR3 and BT474 breast cancer cells results in downregulation of constitutive HER2 activation. Moreover, treatment with the MUC1-C inhibitor, GO-203, was associated with disruption of MUC1-C/HER2 complexes and decreases in tyrosine phosphorylated HER2 (p-HER2) levels. In studies of trastuzumab-resistant SKBR3R and BT474R cells, we found that the association between MUC1-C and HER2 is markedly increased (~20-fold) as compared to that in sensitive cells. Additionally, silencing MUC1-C in the trastuzumab-resistant cells or treatment with GO-203 decreased p-HER2 and AKT activation. Moreover, targeting MUC1-C was associated with downregulation of phospho-p27 and cyclin E, which confer trastuzumab resistance. Consistent with these results, targeting MUC1-C inhibited the growth and clonogenic survival of both trastuzumab-resistant cells. Our results further demonstrate that silencing MUC1-C reverses resistance to trastuzumab and that the combination of GO-203 and trastuzumab is highly synergistic. These findings indicate that MUC1-C contributes to constitutive activation of the HER2 pathway and that targeting MUC1-C represents a potential approach to abrogate trastuzumab resistance. PMID:23912457

  9. Virtual Screening Approaches in Identification of Bioactive Compounds Akin to Delphinidin as Potential HER2 Inhibitors for the Treatment of Breast Cancer.

    PubMed

    Patidar, Kavisha; Deshmukh, Aruna; Bandaru, Srinivas; Lakkaraju, Chandana; Girdhar, Amandeep; Vr, Gutlapalli; Banerjee, Tushar; Nayarisseri, Anuraj; Singh, Sanjeev Kumar

    2016-01-01

    Small molecule tyrosine kinase inhibitors targeting HER 2 receptors have emerged as an important therapeutic approach in inhibition of downstream proliferation and survival signals for the treatment of breast cancers. Recent drug discovery efforts have demonstrated that naturally occurring polyphenolic compounds like delphinidin have potential to inhibit proliferation and promote apoptosis of breast cancer cells by targeting HER2 receptors. While delphinidin may thus reduce tumour size, it is associated with serious side effects like dysphonia. Owing to the narrow therapeutic window of delphinidin, the present study aimed to identify high affinity compounds targeting HER2 with safer pharmacological profiles than delphinidin through virtual screening approaches. Delphinidin served as the query parent for identification of structurally similar compounds by Tanimoto-based similarity searching with a threshold of 95% against the PubChem database. The compounds retrieved were further subjected to Lipinski and Verber's filters to obtain drug like agents, then further filtered by diversity based screens with a cut off of 0.6. The compound with Pubchem ID: 91596862 was identified to have higher affinity than its parent. In addition it also proved to be non-toxic with a better ADMET profile and higher kinase activity. The compound identified in the study can be put to further in vitro drug testing to complement the present study. PMID:27221932

  10. Improved biological activity of a single chain antibody fragment against human epidermal growth factor receptor 2 (HER2) expressed in the periplasm of Escherichia coli.

    PubMed

    Akbari, Vajihe; Sadeghi, Hamid Mir Mohammad; Jafarian-Dehkordi, Abbas; Abedi, Daryoush; Chou, C Perry

    2015-12-01

    A novel monoclonal antibody against human epidermal growth factor receptor 2 (HER2), i.e., pertuzumab (Perjeta®) developed by Genentech, has been verified to be effective in treating metastatic HER2-overexpressing breast cancer. The fact that the presence of the Fc region of the anti-HER2 is uncritical for growth inhibition of tumor cells suggests the potential biological activity of the associated antibody fragments. In the present study, we report functional expression of anti-HER2his-scFv, a single-chain variable fragment (scFv) derived from pertuzumab, in the periplasm of Escherichia coli and its purification. Biological activity of the soluble scFv produced in this manner was characterized using immunofluorescent staining, immunocytochemistry, flow cytometry and cytotoxicity assay. The effect of anti-HER2his-scFv on HER2 dimerization was also assessed by tyrosine kinase assay. It was observed that the purified scFv had a high specificity and affinity to HER2 receptors expressed on the surface of tumor cells with a selective cytotoxic effect on HER2-overexpressing SK-OV-3 cells. In addition, anti-HER2his-scFv was able to suppress phosphorylation of HER2 in the presence of heregulin. The results suggest that anti-HER2his-scFv can be a potential candidate for various therapeutic and diagnosis applications. PMID:26166178

  11. Preventive efficacy of receptor class selective retinoids on HER-2/neu oncogene expressing preneoplastic human mammary epithelial cells.

    PubMed

    Jinno, Hiromitsu; Steiner, Melissa G; Nason-Burchenal, Kathryn; Osborne, Michael P; Telang, Nitin T

    2002-07-01

    Aberrant proliferation is an early-occurring event in vitro prior to tumorigenesis in vivo in the multistep process of carcinogenesis. Inhibition of aberrant proliferation therefore may represent a useful biomarker to evaluate the efficacy of chemopreventive agents. Retinoids have exhibited preventive efficacy in vitro and in vivo predominantly through the retinoic acid receptors (RARs) and the retinoid X receptors (RXRs). Clinically relevant biochemical and cellular mechanistic endpoints for chemopreventive effects of retinoids should provide novel biomarkers. The present study was designed to examine the preventive efficacy of natural retinoids, all-trans-retinoic acid (ATRA) and 9-cis-retinoic acid (9cisRA), and to identify the possible mechanisms for their effects using the HER-2/neu oncogene expressing preneoplastic human mammary epithelial 184-B5/HER cells. Seven-day treatment with ATRA and 9cisRA exhibited a dose-dependent growth inhibition. Long-term (21 days) treatment with IC20 doses of 50 nM ATRA and 100 nM 9cisRA inhibited anchorage-dependent colony forming efficiency by about 75.4% (p<0.01) and 84.9% (p<0.01), respectively. Cell cycle analysis revealed that a 24-h treatment with IC90 doses of 2 microM ATRA and 3 microM 9cisRA accumulates cells in the G0/G1 phase and inhibit S and/or G2/M phase of the cell cycle. ATRA and 9cisRA induced an 11-fold (p=0.03) and a 9-fold (p=0.04) increase in subG0/G1 (apoptotic) population relative to the solvent control, respectively. ATRA and 9cisRA induced 77% (p=0.01) and 51% (p=0.02) decrease in tyrosine kinase immunoreactivity, respectively. Similarly, the two retinoids caused almost a 50% (p=0.01) down-regulation of Bcl-2 immunoreactivity. Western blot analysis revealed that ATRA induced an increase in RARbeta expression and a decrease in RARgamma expression, while 9cisRA down-regulated RXRalpha expression. These data demonstrate that ATRA and 9cisRA may inhibit HER-2/neu induced aberrant proliferation in part by

  12. Antitumor Activity of a Monoclonal Antibody Targeting Major Histocompatibility Complex Class I–Her2 Peptide Complexes

    PubMed Central

    2013-01-01

    Background Applications of trastuzumab are limited to breast cancer patients with high Her2-expressing tumors. We developed a T-cell receptor mimic (TCRm) monoclonal antibody (hereafter called RL1B) that targets the Her2-E75 peptide (residues 369–377)–HLA-A2 complex and examined its effects in Her2-expressing cancer cells. Methods RL1B binding affinity was determined by surface plasmon resonance and specificity was demonstrated using Her2 antigen-positive and negative tumor cell lines. Immunohistochemistry was used to assess binding to frozen sections of human carcinomas (n = 3). Antitumor activity mediated by RL1B and trastuzumab against Her2+ tumor cell lines was evaluated using the WST-1 cell viability assay and caspase-3 and poly(ADP-ribose) polymerase cleavage assays. A xenograft mouse model (n = 6 per group) was used to assess RL1B antitumor activity. Mechanisms of RL1B-mediated cytotoxicity were evaluated with confocal microscopy, flow cytometry, and histology. All statistical tests were two-sided. Results RL1B bound with high specificity and affinity to the E75 peptide–HLA-A2 complex in all Her2+ and HLA-A2+ cancer cell lines and human carcinomas. Compared with control antibody, RL1B suppressed growth of low Her2–expressing breast tumors in mice (mean volume, RL1B vs control = 241mm3 vs 1531mm3; P = .0109) and statistically significantly increased mouse survival (P = .0098). It reduced viability compared to control monoclonal antibody–treated cells and statistically significantly increased caspase 3 activation of all Her2+ carcinoma cell lines tested, whereas trastuzumab induced apoptosis only in high Her2–expressing cancer cells. Mechanisms of RL1B cytotoxicity were associated with antibody internalization and intracellular signaling. Conclusion The TCRm RL1B could be a new approach to immunotherapy of Her2-expressing malignancies. PMID:23300219

  13. Adoptive transfer of autologous, HER2-specific, cytotoxic T lymphocytes for the treatment of HER2-overexpressing breast cancer.

    PubMed

    Bernhard, Helga; Neudorfer, Julia; Gebhard, Kerstin; Conrad, Heinke; Hermann, Christine; Nährig, Jörg; Fend, Falko; Weber, Wolfgang; Busch, Dirk H; Peschel, Christian

    2008-02-01

    The human epidermal growth factor receptor 2 (HER2) has been targeted as a breast cancer-associated antigen by immunotherapeutical approaches based on HER2-directed monoclonal antibodies and cancer vaccines. We describe the adoptive transfer of autologous HER2-specific T-lymphocyte clones to a patient with metastatic HER2-overexpressing breast cancer. The HLA/multimer-based monitoring of the transferred T lymphocytes revealed that the T cells rapidly disappeared from the peripheral blood. The imaging studies indicated that the T cells accumulated in the bone marrow (BM) and migrated to the liver, but were unable to penetrate into the solid metastases. The disseminated tumor cells in the BM disappeared after the completion of adoptive T-cell therapy. This study suggests the therapeutic potential for HER2-specific T cells for eliminating disseminated HER2-positive tumor cells and proposes the combination of T cell-based therapies with strategies targeting the tumor stroma to improve T-cell infiltration into solid tumors. PMID:17646988

  14. Targeted delivery of CXCR4-siRNA by scFv for HER2(+) breast cancer therapy.

    PubMed

    Jiang, Kuo; Li, Jia; Yin, Jipeng; Ma, Qiong; Yan, Bo; Zhang, Xiang; Wang, Lei; Wang, Lifeng; Liu, Tao; Zhang, Yinglong; Fan, Qingyu; Yang, Angang; Qiu, Xiuchun; Ma, Baoan

    2015-08-01

    Therapeutics based on short interfering RNAs (siRNAs) have great potential to treat human diseases. However, the clinical application of siRNAs has been limited by their poor intracellular uptake, low serum stability, and inability to target specific cells. In this study, we addressed this lack of specificity by synthesizing a molecularly targeted CXCR4-siRNA (CXCR4si) for the treatment of HER2(+) breast cancers using a HER2-scFv-arginine nonamer peptide fusion protein (e23sFv-9R) as an siRNA carrier. The e23sFv-9R binding siRNA is able to specifically deliver the siRNA to HER2(+) breast cancer cells and concentrate and persist in orthotopic HER2(+) breast cancer xenografts for at least 36 h. CXCR4si delivered by e23sFv-9R inhibited CXCR4 gene expression, reduced proliferation and metastasis and induced apoptosis in the HER2(+) breast cancer BT-474 cell line in vitro. Moreover, the systemic delivery of CXCR4si by e23sFv-9R is able to suppress tumor growth, reduce metastasis and prolong survival in mice bearing HER2(+) xenografts. This approach causes no systemic toxicity and does not activate the innate immune response, suggesting that a fusion protein carrying CXCR4si shows promise in the treatment of HER2-overexpressing breast cancer. PMID:25956853

  15. AHNP-Streptavidin: A Tetrameric Bacterially Produced Antibody Surrogate Fusion Protein Against p185her2/neu

    SciTech Connect

    Masuda,K.; Richter, M.; Song, X.; Berezov, A.; Masuda, K.; Murali, R.; Greene, M.; Zhang, H.

    2006-01-01

    The anti-p185her2/neu peptidomimetic (AHNP) is a small exo-cyclic peptide derived from the anti-p185her2/neu rhumAb 4D5 (h4D5). AHNP mimics many but not all of the antitumor characteristics exhibited by h4D5. However, the pharmacokinetic profiles of AHNP are less than optimal for therapeutic or diagnostic purposes. To improve the binding affinity to p185her2/neu and the antitumor efficacy, we have engineered a fusion protein containing AHNP and a nonimmunoglobulin protein scaffold, streptavidin (SA). The recombinant protein, AHNP-SA (ASA) bound to p185her2/neu with high affinity, inhibited the proliferation of p185her2/neu-overexpressing cells, and reduced tumor growth induced by p185her2/neu-transformed cells. These data suggest that the bacterially produced tetrameric ASA can be used as an antibody-surrogate molecule. This class of molecule will play a role in the diagnosis and treatment of p185her2/neu-related tumors. Our studies establish a general principle by which a small biologically active synthetic exo-cyclic peptide can be engineered to enhance functional aspects by structured oligomerization and can be produced recombinantly using bacterial expression.

  16. HER2 status and disparities in luminal breast cancers.

    PubMed

    Holowatyj, Andreana N; Ruterbusch, Julie J; Ratnam, Manohar; Gorski, David H; Cote, Michele L

    2016-08-01

    National Comprehensive Care Network guidelines for adjuvant treatment of invasive breast cancer are based on HER2 and hormone receptor (HR) status, where HR+ disease encompasses all estrogen receptor (ER)+ and/or progesterone receptor (PR)+ tumors. We sought to explore clinical and demographic differences among patients with HR+ breast cancer subtypes, and the role of HER2 status, age, race/ethnicity, and socioeconomic status (SES) in disease risk. We evaluated breast cancer subtype distribution, defined by HR and HER2 status, using patient clinical, demographic, and socioeconomic characteristics. Differences in HR categories by demographic and tumor characteristics were examined using chi-squared tests. Multinomial logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI) to quantify associations between breast cancer HR status and demographic factors. We found that differences in HR+ (ER-/PR+ vs. ER+/PR- or ER+/PR+) tumor biology are likely clinically significant and may play a role in breast cancer, regardless of HER2 status. While clinical and patient characteristics differed within each luminal subtype, we found disparities in SES only among Luminal A (HR+/HER2-) tumors. Among HR+/HER2- cases, we observed that ER-/PR+ patients tend to live in areas of higher poverty (OR = 1.20, 95% CI = 1.03-1.40) and are 70% more likely to be aged 50 years or older. However, this pattern was not found in women with Luminal B (HR+/HER2+) disease (Poverty OR = 0.98, 95% CI = 0.76-1.27; Age OR = 1.01, 95% CI = 0.81-1.26). Racial/ethnic disparities among non-Hispanic black and Hispanic women persisted across HR+/HER2- cases compared to non-Hispanic white women. Our findings suggest that while race/ethnicity and SES are correlated, each plays an independent role in contributing to disease among Luminal A tumors. Further study is needed to investigate how tumor biology, race/ethnicity, and socioeconomic disparities among HR+/HER2

  17. Efficacy and Safety of HER2-Targeted Agents for Breast Cancer with HER2-Overexpression: A Network Meta-Analysis

    PubMed Central

    Yu, Qiuyan; Zhu, Zhenli; Liu, Yan; Zhang, Jun; Li, Ke

    2015-01-01

    Background Clinical trials of human epidermal growth factor receptor 2 (HER2)-targeted agents added to standard treatment have been efficacious for HER2-positive (HER2+) advanced breast cancer. To our knowledge, no meta-analysis has evaluated HER2-targeted therapy including trastuzumab emtansine (T-DM1) and pertuzumab for HER2-positive breast caner and ranked the targeted treatments. We performed a network meta-analysis of both direct and indirect comparisons to evaluate the effect of adding HER2-targeted agents to standard treatment and examined side effects. Methods We performed a Bayesian-framework network meta-analysis of randomized controlled trials to compare 6 HER2-targeted treatment regimens and 1 naïve standard treatment (NST, without any-targeted drugs) in targeted treatment of HER2+ breast cancer in adults. These treatment regimens were T-DM1, LC (lapatinib), HC (trastuzumab), PEC (pertuzumab), LHC (lapatinib and trastuzumab), and PEHC (pertuzumab and trastuzumab). The main outcomes were overall survival and response rates. We also examined side effects of rash, LVEF (left ventricular ejection fraction), fatigue, and gastrointestinal disorders, and performed subgroup analysis for the different treatment regimens in metastatic or advanced breast cancer. Results We identified 25 articles of 21 trials, with data for 11,276 participants. T-DM1 and PEHC were more efficient drug regimens with regard to overall survival as compared with LHC, LC, HC and PEC. The incidence of treatment-related rash occurs more frequently in the patients who received LC treatment regimen than PEHC and T-DM1 and HC. In subgroup analysis, T-DM1 was associated with increased overall survival as compared with LC and HC. PEHC was associated with increased overall response as compared with LC, HC, and NST. Conclusions Overall, the regimen of T-DM1 as well as pertuzumab in combination with trastuzumab and docetaxel is efficacious with fewer side effects as compared with other regimens

  18. HER2-targeted immunotoxins with low nonspecific toxicity and immunogenicity.

    PubMed

    Guo, Rui; Cao, Li; Guo, Wenjun; Liu, Hui; Xu, Hua; Fang, Qi; Hong, Zhangyong

    2016-06-17

    Immunotoxins have efficient anti-tumor activity due to their extreme potency. However, dose-limiting off-target toxicity and immunogenicity are the critical barriers for these immunotoxins to be used in a clinical setting. In this study, we designed a Pseudomonas exotoxin A (PE)-based human epidermal growth factor receptor-2 (HER2)-specific immunotoxin HER2-PE25-X7 by deleting most of domain II and introducing seven point mutations into domain III of the PE38 toxin. The anti-cancer activity, off-target toxicity and immunogenicity of this immunotoxin were carefully evaluated in vitro and in vivo. This new construct maintained the therapeutic potency of the original PE38-based immunotoxin HER2-PE38, with a greatly reduced off-target toxicity and immunogenicity. To compare with HER2-PE38, which resulted in the death of most of the mice after a single dose of 1.0 mg/kg, the new construct was completely tolerated at a dose of 10 mg/kg by the mice and almost completely depleted the tumor after treatment with five doses of 5 mg/kg of the immunotoxin. This work demonstrates a potentially attractive therapeutic modality for HER2-specific cancer treatment. PMID:27178207

  19. Autophagy and Apoptotic Crosstalk: Mechanism of Therapeutic Resistance in HER2-Positive Breast Cancer

    PubMed Central

    Zambrano, Joelle; Yeh, Elizabeth S.

    2016-01-01

    While breast cancer patients benefit from the use of HER2 inhibitors, many fail therapy and become resistant to treatment, indicating a critical need to prevent treatment failure. A number of studies have emerged that highlight the catabolic process of autophagy in breast cancer as a mechanism of resistance to chemotherapy and targeted inhibitors. Furthermore, recent research has begun to dissect how autophagy signaling crosstalks with apoptotic signaling. Thus, a possible strategy in fighting resistance is to couple targeting of apoptotic and autophagy signaling pathways. In this review, we discuss how cellular response by autophagy circumvents cell death to promote resistance of breast cancers to HER2 inhibitors, as well as the potential avenues of therapeutic intervention. PMID:26997868

  20. The Mysterious Ways of ErbB2/HER2 Trafficking

    PubMed Central

    Bertelsen, Vibeke; Stang, Espen

    2014-01-01

    The EGFR- or ErbB-family of receptor tyrosine kinases consists of EGFR/ErbB1, ErbB2/HER2, ErbB3/HER3 and ErbB4/HER4. Receptor activation and downstream signaling are generally initiated upon ligand-induced receptor homo- or heterodimerization at the plasma membrane, and endocytosis and intracellular membrane transport are crucial for regulation of the signaling outcome. Among the receptors, ErbB2 is special in several ways. Unlike the others, ErbB2 has no known ligand, but is still the favored dimerization partner. Furthermore, while the other receptors are down-regulated either constitutively or upon ligand-binding, ErbB2 is resistant to down-regulation, and also inhibits down-regulation of its partner upon heterodimerization. The reason(s) why ErbB2 is resistant to down-regulation are the subject of debate. Contrary to other ErbB-proteins, mature ErbB2 needs Hsp90 as chaperone. Several data suggest that Hsp90 is an important regulator of factors like ErbB2 stability, dimerization and/or signaling. Hsp90 inhibitors induce degradation of ErbB2, but whether Hsp90 directly makes ErbB2 endocytosis resistant is unclear. Exposure to anti-ErbB2 antibodies can also induce down-regulation of ErbB2. Down-regulation induced by Hsp90 inhibitors or antibodies does at least partly involve internalization and endosomal sorting to lysosomes for degradation, but also retrograde trafficking to the nucleus has been reported. In this review, we will discuss different molecular mechanisms suggested to be important for making ErbB2 resistant to down-regulation, and review how membrane trafficking is involved when down-regulation and/or relocalization of ErbB2 is induced. PMID:25102001

  1. The assessment of HER2 status in breast cancer: the past, the present, and the future.

    PubMed

    Nitta, Hiroaki; Kelly, Brian D; Allred, Craig; Jewell, Suzan; Banks, Peter; Dennis, Eslie; Grogan, Thomas M

    2016-06-01

    Humanized monoclonal anti-human growth factor receptor 2 (HER2) antibody trastuzumab was approved for HER2 positive breast cancer patient treatment 11 years after the demonstration of HER2 gene amplification associated with the HER2 protein overexpression in breast cancer in 1987. HER2 positive status of breast cancer patients is assessed by HER2 gene amplification with in situ hybridization (ISH) and/or HER2 protein overexpression with immunohistochemistry (IHC). Because the discordance between quantitative HER2 ISH and subjective, semi-quantitative HER2 IHC assay results is a well-recognized issue of HER2 testing, we developed an assay combining HER2 ISH and HER2 IHC assays (HER2 gene-protein assay; HER2 GPA) as one test on the same tissue section. HER2 GPA allows pathologists to score the HER2 gene and HER2 protein status simultaneously at the individual cell level. The possibility that HER2 GPA may become the next generation of HER2 testing is discussed, particularly for cases in which it is difficult to assess the HER2 status of breast cancer patients due to the HER2 heterogeneity. PMID:27061008

  2. Src, a potential target for overcoming trastuzumab resistance in HER2-positive breast carcinoma

    PubMed Central

    Peiró, G; Ortiz-Martínez, F; Gallardo, A; Pérez-Balaguer, A; Sánchez-Payá, J; Ponce, J J; Tibau, A; López-Vilaro, L; Escuin, D; Adrover, E; Barnadas, A; Lerma, E

    2014-01-01

    Background: Src is a non-receptor tyrosine kinase involved in signalling and crosstalk between growth-promoting pathways. We aim to investigate the relationship of active Src in response to trastuzumab of HER2-positive breast carcinomas. Methods: We selected 278 HER2-positive breast cancer patients with (n=154) and without (n=124) trastuzumab treatment. We performed immunohistochemistry on paraffin-embedded tissue microarrays of active Src and several proteins involved in the PI3K/Akt/mTOR pathway, PIK3CA mutational analysis and in vitro studies (SKBR3 and BT474 cancer cells). The results were correlated with clinicopathological factors and patients' outcome. Results: Increased pSrc-Y416 was demonstrated in trastuzumab-resistant cells and in 37.8% of tumours that correlated positively with tumour size, necrosis, mitosis, metastasis to the central nervous system, p53 overexpression and MAPK activation but inversely with EGFR and p27. Univariate analyses showed an association of increased active Src with shorter survival in patients at early stage with HER2/hormone receptor-negative tumours treated with trastuzumab. Conclusions: Src activation participates in trastuzumab mechanisms of resistance and indicates poor prognosis, mainly in HER2/hormone receptor-negative breast cancer. Therefore, blocking this axis may be beneficial in those patients. PMID:24937674

  3. A Naturally Occurring HER2 Carboxy-Terminal Fragment Promotes Mammary Tumor Growth and Metastasis▿ †

    PubMed Central

    Pedersen, Kim; Angelini, Pier-Davide; Laos, Sirle; Bach-Faig, Alba; Cunningham, Matthew P.; Ferrer-Ramón, Cristina; Luque-García, Antonio; García-Castillo, Jesús; Parra-Palau, Josep Lluis; Scaltriti, Maurizio; y Cajal, Santiago Ramón; Baselga, José; Arribas, Joaquín

    2009-01-01

    HER2 is a tyrosine kinase receptor causally involved in cancer. A subgroup of breast cancer patients with particularly poor clinical outcomes expresses a heterogeneous collection of HER2 carboxy-terminal fragments (CTFs). However, since the CTFs lack the extracellular domain that drives dimerization and subsequent activation of full-length HER2, they are in principle expected to be inactive. Here we show that at low expression levels one of these fragments, 611-CTF, activated multiple signaling pathways because of its unanticipated ability to constitutively homodimerize. A transcriptomic analysis revealed that 611-CTF specifically controlled the expression of genes that we found to be correlated with poor prognosis in breast cancer. Among the 611-CTF-regulated genes were several that have previously been linked to metastasis, including those for MET, EPHA2, matrix metalloproteinase 1, interleukin 11, angiopoietin-like 4, and different integrins. It is thought that transgenic mice overexpressing HER2 in the mammary glands develop tumors only after acquisition of activating mutations in the transgene. In contrast, we show that expression of 611-CTF led to development of aggressive and invasive mammary tumors without the need for mutations. These results demonstrate that 611-CTF is a potent oncogene capable of promoting mammary tumor progression and metastasis. PMID:19364815

  4. tabAnti-HER2 (erbB-2) oncogene effects of phenolic compounds directly isolated from commercial Extra-Virgin Olive Oil (EVOO)

    PubMed Central

    Menendez, Javier A; Vazquez-Martin, Alejandro; Garcia-Villalba, Rocio; Carrasco-Pancorbo, Alegria; Oliveras-Ferraros, Cristina; Fernandez-Gutierrez, Alberto; Segura-Carretero, Antonio

    2008-01-01

    molecular mechanism contributing to HER2 overexpression (i.e. naturally by gene amplification and ectopically driven by a viral promoter). Pre-treatment with the proteasome inhibitor MG132 prevented EVOO polyphenols-induced HER2 depletion. Conclusion The ability of EVOO-derived polyphenols to inhibit HER2 activity by promoting the proteasomal degradation of the HER2 protein itself, together with the fact that humans have safely been ingesting secoiridoids and lignans as long as they have been consuming olives and OO, support the notion that the stereochemistry of these phytochemicals might provide an excellent and safe platform for the design of new HER2-targeting agents. PMID:19094209

  5. A single-domain antibody-linked Fab bispecific antibody Her2-S-Fab has potent cytotoxicity against Her2-expressing tumor cells.

    PubMed

    Li, Aifen; Xing, Jieyu; Li, Li; Zhou, Changhua; Dong, Bin; He, Ping; Li, Qing; Wang, Zhong

    2016-12-01

    Her2, which is frequently overexpressed in breast cancer, is one of the most studied tumor-associated antigens for cancer therapy. Anti-HER2 monoclonal antibody, trastuzumab, has achieved significant clinical benefits in metastatic breast cancer. In this study, we describe a novel bispecific antibody Her2-S-Fab targeting Her2 by linking a single domain anti-CD16 VHH to the trastuzumab Fab. The Her2-S-Fab antibody can be efficiently expressed and purified from Escherichia coli, and drive potent cancer cell killing in HER2-overexpressing cancer cells. In xenograft model, the Her2-S-Fab suppresses tumor growth in the presence of human immune cells. Our results suggest that the bispecific Her2-S-Fab may provide a valid alternative to Her2 positive cancer therapy. PMID:27112931

  6. Identification of novel pathways linking epithelial-to-mesenchymal transition with resistance to HER2-targeted therapy

    PubMed Central

    Creedon, Helen; Gómez-Cuadrado, Laura; Tarnauskaitė, Žygimantė; Balla, Jozef; Canel, Marta; MacLeod, Kenneth G.; Serrels, Bryan; Fraser, Craig; Unciti-Broceta, Asier; Tracey, Natasha; Le Bihan, Thierry; Klinowska, Teresa; Sims, Andrew H.; Byron, Adam; Brunton, Valerie G.

    2016-01-01

    Resistance to human epidermal growth factor receptor 2 (HER2)-targeted therapies in the treatment of HER2-positive breast cancer is a major clinical problem. To identify pathways linked to resistance, we generated HER2-positive breast cancer cell lines which are resistant to either lapatinib or AZD8931, two pan-HER family kinase inhibitors. Resistance was HER2 independent and was associated with epithelial-to-mesenchymal transition (EMT), resulting in increased proliferation and migration of the resistant cells. Using a global proteomics approach, we identified a novel set of EMT-associated proteins linked to HER2-independent resistance. We demonstrate that a subset of these EMT-associated genes is predictive of prognosis within the ERBB2 subtype of human breast cancers. Furthermore, targeting the EMT-associated kinases Src and Axl potently inhibited proliferation of the resistant cells, and inhibitors to these kinases may provide additional options for the treatment of HER2-independent resistance in tumors. PMID:26883193

  7. Salicylic acid signaling inhibits apoplastic reactive oxygen species signaling

    PubMed Central

    2014-01-01

    Background Reactive oxygen species (ROS) are used by plants as signaling molecules during stress and development. Given the amount of possible challenges a plant face from their environment, plants need to activate and prioritize between potentially conflicting defense signaling pathways. Until recently, most studies on signal interactions have focused on phytohormone interaction, such as the antagonistic relationship between salicylic acid (SA)-jasmonic acid and cytokinin-auxin. Results In this study, we report an antagonistic interaction between SA signaling and apoplastic ROS signaling. Treatment with ozone (O3) leads to a ROS burst in the apoplast and induces extensive changes in gene expression and elevation of defense hormones. However, Arabidopsis thaliana dnd1 (defense no death1) exhibited an attenuated response to O3. In addition, the dnd1 mutant displayed constitutive expression of defense genes and spontaneous cell death. To determine the exact process which blocks the apoplastic ROS signaling, double and triple mutants involved in various signaling pathway were generated in dnd1 background. Simultaneous elimination of SA-dependent and SA-independent signaling components from dnd1 restored its responsiveness to O3. Conversely, pre-treatment of plants with SA or using mutants that constitutively activate SA signaling led to an attenuation of changes in gene expression elicited by O3. Conclusions Based upon these findings, we conclude that plants are able to prioritize the response between ROS and SA via an antagonistic action of SA and SA signaling on apoplastic ROS signaling. PMID:24898702

  8. Renal toxicity of anticancer agents targeting HER2 and EGFR.

    PubMed

    Cosmai, Laura; Gallieni, Maurizio; Porta, Camillo

    2015-12-01

    EGFR and HER2 are found overexpressed and/or activated in many different human malignancies (e.g. breast and colon cancer), and a number of drugs specifically targeting these two tyrosine kinases have been developed over the years as anticancer agents. In the present review, the renal safety profile of presently available agents targeting either HER2 or EGFR will be discussed, together with the peculiarities related to their clinical use in patients with impaired renal function, or even in dialysis. Indeed, even though renal toxicity is not so common with these agents, it may nevertheless happen, especially when these agents are combined with traditional chemotherapeutic agents. As a whole, kidney impairment or dialysis should not be regarded per se as reasons not to administer or to stop an active anti-HER or anti-EGFR anticancer treatment, especially given the possibility of significantly improving the life expectancy of many cancer patients with the use of these agents. PMID:26341657

  9. Progesterone inhibition of oxytocin signaling in endometrium

    PubMed Central

    Bishop, Cecily V.

    2013-01-01

    Expression of the oxytocin receptor (OXTR) in the endometrium of ruminant species is regulated by the ovarian steroids progesterone (P) and estradiol (E). Near the end of the estrous cycle, long-term exposure of endometrial epithelial cells to P results in loss of genomic P receptors (PGRs), leading to an increase in E receptors (ERs). Genomic regulation of the OXTR is mediated via suppression of ER signaling by P. Upon OT binding at the plasma membrane of endometrial cells, a signaling cascade is generated stimulating release of prostaglandin F2α (PGF2α). Transport of PGF2α to the ovary results in release of OT by luteal cells in a positive feedback loop leading to luteal regression. This signaling cascade can be rapidly blocked by exposing endometrial cells to physiologic levels of P. This mini review will focus on the mechanisms by which P may act to block OXTR signaling and the luteolytic cascade in the ruminant endometrium, with special focus on both non-genomic signaling pathways and non-receptor actions of P at the level of the plasma membrane. While this review focuses on ruminant species, non-classical blockage of OXTR signaling may be important for fertility in women. PMID:23966904

  10. Investigating Molecular Mechanisms of Activation and Mutation of the HER2 Receptor Tyrosine Kinase through Computational Modeling and Simulation

    PubMed Central

    Telesco, Shannon E.; Shih, Andrew; Liu, Yingting; Radhakrishnan, Ravi

    2011-01-01

    mechanism of HER2 in the context of the other ErbB members is crucial for understanding how the activated kinase might interact with downstream molecules and couple to signaling cascades that promote cancer. Our comparative analysis furthers insight into the mechanics of activation of the HER2 kinase and enables us to predict the effect of an identified insertion mutation on HER2 activation. Further understanding of the mechanism of HER2 kinase activation at the atomic scale and how it couples to downstream signaling at the cellular scale will elucidate predictive molecular phenotypes that may indicate likelihood of response to specific therapies for HER2-mediated cancers. PMID:25346782

  11. HER2 mutated breast cancer responds to treatment with single agent neratinib, a second generation HER2/EGFR tyrosine kinase inhibitor

    PubMed Central

    Ben–Baruch, Noa Efrat; Bose, Ron; Kavuri, Shyam M.; Ma, Cynthia X.; Ellis, Matthew J.

    2015-01-01

    Activating mutations in the HER2 tyrosine kinase have been identified in human breast cancers that lack HER2 gene amplification. These patients are not candidates for HER2 targeted drugs under current standards of care, but preclinical data strongly suggest that these patients will benefit from anti-HER2 drugs. In this case report, we describe a young woman with metastatic breast cancer whose tumor was found to carry a HER2 L755S mutation, which is in the kinase domain of HER2. Treatment with the second generation HER2/EGFR tyrosine kinase inhibitor, neratinib, resulted in partial response and dramatic improvement in the patient’s function status. This partial response lasted 11 months and when the patient’s cancer progressed, she was treated with neratinib plus capecitabine and her cancer again responded. This second response parallels the benefit seen with continuing trastuzumab in HER2 amplified breast cancer after disease progression. This case is the first report, to our knowledge, of successful single agent treatment of HER2 mutated breast cancer. Two clinical trials of neratinib for HER2 mutated, metastatic breast cancer are currently enrolling patients. Further, data from The Cancer Genome Atlas project have identified HER2 mutations in a wide range of solid tumors, including bladder, colorectal, and non-small cell lung cancer, suggesting that clinical trials of neratinib or neratinib-based combinations for HER2 mutated solid tumors is warranted. PMID:26358790

  12. HER2-Mutated Breast Cancer Responds to Treatment With Single-Agent Neratinib, a Second-Generation HER2/EGFR Tyrosine Kinase Inhibitor.

    PubMed

    Ben-Baruch, Noa Efrat; Bose, Ron; Kavuri, Shyam M; Ma, Cynthia X; Ellis, Matthew J

    2015-09-01

    Activating mutations in the HER2 tyrosine kinase have been identified in human breast cancers that lack HER2 gene amplification. These patients are not candidates for HER2-targeted drugs under current standards of care, but preclinical data strongly suggest that these patients will benefit from anti-HER2 drugs. This case report describes a young woman with metastatic breast cancer whose tumor was found to carry a HER2 L755S mutation, which is in the kinase domain of HER2. Treatment with the second-generation HER2/EGFR tyrosine kinase inhibitor neratinib resulted in partial response and dramatic improvement in the patient's functional status. This partial response lasted 11 months, and when the patient's cancer progressed, she was treated with neratinib plus capecitabine and her cancer again responded. This second response parallels the benefit seen with continuing trastuzumab in HER2-amplified breast cancer after disease progression. This case represents the first report, to our knowledge, of successful single-agent treatment of HER2-mutated breast cancer. Two clinical trials of neratinib for HER2-mutated metastatic breast cancer are currently enrolling patients. Further, data from The Cancer Genome Atlas project have identified HER2 mutations in a wide range of solid tumors, including bladder, colorectal, and non-small cell lung cancers, suggesting that clinical trials of neratinib or neratinib-based combinations for HER2-mutated solid tumors is warranted. PMID:26358790

  13. Aberrant Splicing of Estrogen Receptor, HER2, and CD44 Genes in Breast Cancer

    PubMed Central

    Inoue, Kazushi; Fry, Elizabeth A.

    2015-01-01

    Breast cancer (BC) is the most common cause of cancer-related death among women under the age of 50 years. Established biomarkers, such as hormone receptors (estrogen receptor [ER]/progesterone receptor) and human epidermal growth factor receptor 2 (HER2), play significant roles in the selection of patients for endocrine and trastuzumab therapies. However, the initial treatment response is often followed by tumor relapse with intrinsic resistance to the first-line therapy, so it has been expected to identify novel molecular markers to improve the survival and quality of life of patients. Alternative splicing of pre-messenger RNAs is a ubiquitous and flexible mechanism for the control of gene expression in mammalian cells. It provides cells with the opportunity to create protein isoforms with different, even opposing, functions from a single genomic locus. Aberrant alternative splicing is very common in cancer where emerging tumor cells take advantage of this flexibility to produce proteins that promote cell growth and survival. While a number of splicing alterations have been reported in human cancers, we focus on aberrant splicing of ER, HER2, and CD44 genes from the viewpoint of BC development. ERα36, a splice variant from the ER1 locus, governs nongenomic membrane signaling pathways triggered by estrogen and confers 4-hydroxytamoxifen resistance in BC therapy. The alternative spliced isoform of HER2 lacking exon 20 (Δ16HER2) has been reported in human BC; this isoform is associated with transforming ability than the wild-type HER2 and recapitulates the phenotypes of endocrine therapy-resistant BC. Although both CD44 splice isoforms (CD44s, CD44v) play essential roles in BC development, CD44v is more associated with those with favorable prognosis, such as luminal A subtype, while CD44s is linked to those with poor prognosis, such as HER2 or basal cell subtypes that are often metastatic. Hence, the detection of splice variants from these loci will provide keys

  14. Prognostic Value of KIF2A and HER2-Neu Overexpression in Patients With Epithelial Ovarian Cancer

    PubMed Central

    Wang, Di; Zhu, Huijun; Ye, Qing; Wang, Chenyi; Xu, Yunzhao

    2016-01-01

    Abstract Kinesin family member 2A (KIF2A) is a member of Kinesin-13 family and involved in cell migration and cell signaling. Human epidermal growth factor receptor 2 (HER2-neu) is implicated in the development of many cancers. Both of these 2 proteins are upstream inducer of PI3K/AKT signaling pathway that plays an important role in the regulation of many cellular events including proliferation, survival, and invasion. We hypothesized that aberrant KIF2A and HER2-neu expression might be associated with aggressive behavior of epithelial ovarian cancer (EOC). To address the prognostic implications of KIF2A and HER2-neu in EOC, we assessed protein levels of KIF2A and HER2-neu in 159 ovarian and fallopian tube tissues (111 carcinomas and 48 normal ovary or fallopian tube tissues) by immunohistochemistry (IHC) analysis on tissue microarray and KIF2A mRNA levels in 35 ovarian and fallopian tube tissues (15 carcinomas and 20 normal ovary or fallopian tube tissues) by real-time PCR. We found that significantly higher KIF2A mRNA expression in EOC tumors than that in normal ovary or fallopian tube tissues. The IHC results showed that protein of KIF2A and HER2-neu was overexpressed in EOC tissues compared with normal ovary or fallopian tube tissues, and KIF2A expression level was significantly associated with lymph nodes, metastasis, ascites cells, and FIGO stage. No correlation between KIF2A and HER2-neu expression was observed. Survival analysis showed that patients with KIF2A and HER2-neu overexpression had a worse overall survival (OS) as compared to patients with low or none expression of the 2 proteins. Multivariate analysis of variance revealed that overexpression of KIF2A was an independent prognostic factor for OS. These findings indicate the important role of KIF2A in predicting EOC prognosis. PMID:26937910

  15. Continuous quantification of HER2 expression by microfluidic precision immunofluorescence estimates HER2 gene amplification in breast cancer

    PubMed Central

    Dupouy, Diego G.; Ciftlik, Ata Tuna; Fiche, Maryse; Heintze, Déborah; Bisig, Bettina; de Leval, Laurence; Gijs, Martin A. M.

    2016-01-01

    Chromogenic immunohistochemistry (IHC) is omnipresent in cancer diagnosis, but has also been criticized for its technical limit in quantifying the level of protein expression on tissue sections, thus potentially masking clinically relevant data. Shifting from qualitative to quantitative, immunofluorescence (IF) has recently gained attention, yet the question of how precisely IF can quantify antigen expression remains unanswered, regarding in particular its technical limitations and applicability to multiple markers. Here we introduce microfluidic precision IF, which accurately quantifies the target expression level in a continuous scale based on microfluidic IF staining of standard tissue sections and low-complexity automated image analysis. We show that the level of HER2 protein expression, as continuously quantified using microfluidic precision IF in 25 breast cancer cases, including several cases with equivocal IHC result, can predict the number of HER2 gene copies as assessed by fluorescence in situ hybridization (FISH). Finally, we demonstrate that the working principle of this technology is not restricted to HER2 but can be extended to other biomarkers. We anticipate that our method has the potential of providing automated, fast and high-quality quantitative in situ biomarker data using low-cost immunofluorescence assays, as increasingly required in the era of individually tailored cancer therapy. PMID:26856369

  16. Moderate level of HER2 expression and its prognostic significance in breast cancer with intermediate grade.

    PubMed

    Ignatov, Tanja; Eggemann, Holm; Burger, Elke; Fettke, Franziska; Costa, Serban Dan; Ignatov, Atanas

    2015-06-01

    Overexpression of human epidermal growth factor receptor 2 (HER2) is an important prognostic and predictive marker of response to anti-HER2 therapy in breast cancer. Our goal was to analyze the prognostic significance of moderate expression of HER2 in breast cancer with intermediate differentiation grade. We performed a multicenter retrospective register study of 8494 patients with primary non-metastatic breast cancer admitted between 2000 and 2011 to eight Clinics in Saxony-Anhalt, federal state of Germany. Patients were divided into three groups according to their HER2 score: 4073 were classified as HER2 negative (HER2 0 and 1+), 822 HER2 moderate (HER2 2+/HER2), and 1238 HER2 positive (HER2 3+ or HER2 2+/HER2+). HER2-positive cases were excluded from analysis. Tumors with moderate HER2 (HER2 2+) expression demonstrated an aggressive behavior and worse patient survival compared with HER2 0 and 1+ status. HER2 2+ status was associated with shorter median overall survival (OS) (P < 0.0001) in breast cancer patients with an intermediate grade of differentiation. Comparing low-grade and high-grade tumors, HER2 moderate expression did not significantly influence patient survival. In multivariate analysis after adjustment for other prognostic factors HER2 2+ status remained an unfavorable prognostic factor for OS (HR 1.224, 95 % CI 1.059-1.415, P = 0.006) in breast cancer patients with an intermediate grade of differentiation. HER2 2+ status is an unfavorable prognostic factor regarding the OS of breast cancer patients with intermediate grade of differentiation and could be used to identify patients, who may benefit from adjuvant therapy. PMID:25926338

  17. High-throughput screening system to identify small molecules that induce internalization and degradation of HER2.

    PubMed

    Isa, Masayuki; Asanuma, Daisuke; Namiki, Shigeyuki; Kumagai, Kazuo; Kojima, Hirotatsu; Okabe, Takayoshi; Nagano, Tetsuo; Hirose, Kenzo

    2014-10-17

    Overexpression of growth factor receptors in cancers, e.g., human epidermal growth factor receptor 2 (HER2) in ovarian and breast cancers, is associated with aggressiveness. A possible strategy to treat cancers that overexpress those receptors is blockade of receptor signaling by inducing receptor internalization and degradation. In this study, we developed a cell-based high-throughput screening (HTS) system to identify small molecules that induce HER2 internalization by employing our recently developed acidic-pH-activatable probe in combination with protein labeling technology. Our HTS system enabled facile and reliable quantification of HER2 internalization with a Z' factor of 0.66 and a signal-to-noise ratio of 44.6. As proof of concept, we used the system to screen a ∼155,000 small-molecule library and identified three hits that induced HER2 internalization and degradation via at least two distinct mechanisms. This HTS platform should be adaptable to other disease-related receptors in addition to HER2. PMID:25140805

  18. Pertuzumab: in the first-line treatment of HER2-positive metastatic breast cancer.

    PubMed

    Keating, Gillian M

    2012-02-12

    The humanized monoclonal antibody pertuzumab is the first in a new class of drugs, the human epidermal growth factor receptor (HER) dimerization inhibitors. Given that pertuzumab binds to a different epitope of the HER2 extracellular domain than trastuzumab, combination therapy with pertuzumab plus trastuzumab may result in more comprehensive blockade of HER2 signalling than can be achieved with trastuzumab alone. The efficacy of adding pertuzumab to trastuzumab plus docetaxel for the first-line treatment of HER2-positive metastatic breast cancer was demonstrated in the randomized, double-blind, multinational, phase III CLEOPATRA trial. Both independently assessed progression-free survival (primary endpoint) and investigator-assessed progression-free survival were significantly improved in patients receiving pertuzumab plus trastuzumab and docetaxel compared with those receiving placebo plus trastuzumab and docetaxel. The prespecified interim analysis of survival revealed a strong trend towards a survival benefit associated with pertuzumab, although this was not considered statistically significant. The objective response rate was higher with pertuzumab than with placebo. Intravenous pertuzumab had an acceptable tolerability profile when added to trastuzumab and docetaxel in the CLEOPATRA trial. PMID:22316351

  19. Association of HER2 codon 655 polymorphism with ovarian cancer.

    PubMed

    Watrowski, Rafał; Castillo-Tong, Dan Cacsire; Schuster, Eva; Fischer, Michael B; Speiser, Paul; Zeillinger, Robert

    2016-06-01

    The role of the human epidermal growth factor receptor 2 (HER2) codon 655 (Ile655Val) polymorphism in ovarian cancer is not fully understood. Two studies indicated a possible association between the Val allele and elevated risk or reduced prognosis of ovarian cancer. We investigated the HER2 codon 655 (rs1136201) polymorphism in 242 Austrian women-142 ovarian cancer patients and 100 healthy controls-by polymerase chain reaction and pyrosequencing. Associations between Ile655Val polymorphism and clinicopathological variables (e.g., age, FIGO stage, grading, serous vs. non-serous histology) were evaluated. The genotype distributions in ovarian cancer patients and controls were: AA; 66.2 %, AG; 25.35 %, GG; 8.45 %, and AA; 63 %, AG; 34 %, GG; 3.7 %, respectively (OR 1.15, CI 95 % 0.67-1.96). We observed a non-significant trend toward elevated cancer risk in Val/Val genotype (OR 2.98, CI 95 % 0.82-10.87, p = 0.10). Of note, 11 out of 12 Val/Val homozygotes were postmenopausal. The link between the Val/Val homozygosity and age over 50 years at diagnosis (OR 0.15, CI 95 % 0.02-1.2) was barely significant (p = 0.056). Summarizing, our data indicated a non-significant trend toward increased ovarian cancer risk in the Val/Val homozygosity, especially in women aged above 50 years. Further large-cohort studies focusing on the role of the HER2 codon 655 Val allele are needed. PMID:26666819

  20. Isolated Splenic Metastases of Her2+++ Gastroesophageal Junction Adenocarcinoma

    PubMed Central

    Sigrand, Julie; Bazin, Camille; Ewald, Jacques; Dermeche, Slimane; Ries, Pauline; Poizat, Flora; Guiramand, Jerome; Raoul, Jean-Luc

    2016-01-01

    Isolated metastases from gastric adenocarcinoma to the spleen are very infrequent. Usually, there are multiple metastases from gastric cancer, and isolated splenic metastases are very rare [Lam and Tang: Arch Pathol Lab Med 2000;124:526–530] because of certain anatomical and physiological characteristics (e.g., angulation between the splenic artery and celiac trunk, paucity of afferent lymph flow toward the spleen, contractility of the spleen and major immune content). Here, we report 2 cases of isolated splenic metastases from an adenocarcinoma of the gastroesophageal junction, both with long-term survival outcome and overexpression of Her2. PMID:27065846

  1. Isolated Splenic Metastases of Her2+++ Gastroesophageal Junction Adenocarcinoma.

    PubMed

    Sigrand, Julie; Bazin, Camille; Ewald, Jacques; Dermeche, Slimane; Ries, Pauline; Poizat, Flora; Guiramand, Jerome; Raoul, Jean-Luc

    2016-01-01

    Isolated metastases from gastric adenocarcinoma to the spleen are very infrequent. Usually, there are multiple metastases from gastric cancer, and isolated splenic metastases are very rare [Lam and Tang: Arch Pathol Lab Med 2000;124:526-530] because of certain anatomical and physiological characteristics (e.g., angulation between the splenic artery and celiac trunk, paucity of afferent lymph flow toward the spleen, contractility of the spleen and major immune content). Here, we report 2 cases of isolated splenic metastases from an adenocarcinoma of the gastroesophageal junction, both with long-term survival outcome and overexpression of Her2. PMID:27065846

  2. A novel cell-penetrating peptide suppresses breast tumorigenesis by inhibiting β-catenin/LEF-1 signaling

    PubMed Central

    Hsieh, Tsung-Hua; Hsu, Chia-Yi; Tsai, Cheng-Fang; Chiu, Chien-Chih; Liang, Shih-Shin; Wang, Tsu-Nai; Kuo, Po-Lin; Long, Cheng-Yu; Tsai, Eing-Mei

    2016-01-01

    The inhibition of β-catenin/LEF-1 signaling is an emerging strategy in cancer therapy. However, clinical targeted treatment of the β-catenin/LEF-1 complex remains relatively ineffective. Therefore, development of specific molecular targets is a key approach for identifying new cancer therapeutics. Thus, we attempted to synthesize a peptide (TAT-NLS-BLBD-6) that could interfere with the interaction of β-catenin and LEF-1 at nuclei in human breast cancer cells. TAT-NLS-BLBD-6 directly interacted with β-catenin and inhibited breast cancer cell growth, invasion, migration, and colony formation as well as increased arrest of sub-G1 phase and apoptosis; it also suppressed breast tumor growth in nude mouse and zebrafish xenotransplantation models, showed no signs of toxicity, and did not affect body weight. Furthermore, the human global gene expression profiles and Ingenuity Pathway Analysis software showed that the TAT-NLS-BLBD-6 downstream target genes were associated with the HER-2 and IL-9 signaling pathways. TAT-NLS-BLBD-6 commonly down-regulated 27 candidate genes in MCF-7 and MDA-MB-231 cells, which are concurrent with Wnt downstream target genes in human breast cancer. Our study suggests that TAT-NLS-BLBD-6 is a promising drug candidate for the development of effective therapeutics specific for Wnt/β-catenin signaling inhibition. PMID:26750754

  3. Antibody response to HER2 extracellular domain and subdomains in mouse following DNA immunization.

    PubMed

    Sadri-Ardalani, Fateme; Shabani, Mahdi; Amiri, Mohammad Mehdi; Bahadori, Motahareh; Emami, Shaghayegh; Sarrafzadeh, Ali Reza; Noutash-Haghighat, Farzaneh; Jeddi-Tehrani, Mahmood; Shokri, Fazel

    2016-01-01

    Human epidermal growth factor receptor 2 (HER2) is overexpressed in 15-20 % of breast cancer patients and is an appropriate target for immunotherapy in these patients. Monoclonal antibodies (mAbs) specific to HER2 are currently applied to treat breast cancer patients with HER2 overexpression. Active immunization with HER2 DNA or protein has been considered as a suitable alternative. The aim of this study is to evaluate anti-HER2 antibody response in serum of mice immunized with DNA constructs containing full extracellular domain (fECD) or subdomains of human HER2. Four extracellular subdomains and also fECD of HER2 were cloned into pCMV6-Neo vector. Different groups of Balb/C mice were immunized with HER2 DNA constructs and boosted with HER2 recombinant protein. The anti-HER2 antibody was subsequently determined by ELISA, flow cytometry, and immunohistochemistry. Anti-HER2 antibody was detected only in serum of mice immunized with fECD DNA. None of HER2 extracellular subdomains induced appreciable levels of anti-HER2 antibody. However, boosting with fECD or extracellular subdomain III (DIII) recombinant protein resulted in enhanced anti-HER2 fECD as well as anti-HER2 subdomain antibody responses. In this regard, almost all (99 %) of HER2-overexpressing BT474 cells could be detected by serum antibody from mice immunized with HER2 subdomain DNA and boosted with recombinant HER2 protein by flow cytometry. Similarly, serum of mice immunized with DIII DNA construct and boosted with recombinant DIII protein could also recognize these cells, but to a lesser extent (50 %). Our findings suggest that combination of HER2 DNA and protein immunization could effectively induce anti-HER2 antibody response in Balb/C mice. PMID:26282003

  4. Differential survival following trastuzumab treatment based on quantitative HER2 expression and HER2 homodimers in a clinic-based cohort of patients with metastatic breast cancer

    PubMed Central

    2010-01-01

    Background We have recently described the correlation between quantitative measures of HER2 expression or HER2 homodimers by the HERmark assay and objective response (RR), time-to progression (TTP), and overall survival (OS) in an expanded access cohort of trastuzumab-treated HER2-positive patients with metastatic breast cancer (MBC) who were stringently selected by fluorescence in situ hybridization (FISH). Multivariate analyses suggested a continuum of HER2 expression that correlated with outcome following trastuzumab. Here we investigate the relationship between HER2 expression or HER2 homodimers and OS in a clinic-based population of patients with MBC selected primarily by IHC. Methods HERmark, a proximity-based assay designed to detect and quantitate protein expression and dimerization in formalin-fixed paraffin-embedded (FFPE) tissues, was used to measure HER2 expression and HER2 homodimers in FFPE samples from patients with MBC. Assay results were correlated with OS using univariate Kaplan-Meier, hazard function plots, and multivariate Cox regression analyses. Results Initial analyses revealed a parabolic relationship between continuous measures of HER2 expression and risk of death, suggesting that the assumption of linearity for the HER2 expression measurements may be inappropriate in subsequent multivariate analyses. Cox regression analyses using the categorized variable of HER2 expression level demonstrated that higher HER2 levels predicted better survival outcomes following trastuzumab treatment in the high HER2-expressing group. Conclusions These data suggest that the quantitative amount of HER2 expression measured by Hermark may be a new useful marker to identify a more relevant target population for trastuzumab treatment in patients with MBC. PMID:20178580

  5. Model-based analysis of HER activation in cells co-expressing EGFR, HER2 and HER3.

    PubMed

    Shankaran, Harish; Zhang, Yi; Tan, Yunbing; Resat, Haluk

    2013-01-01

    The HER/ErbB family of receptor tyrosine kinases drives critical responses in normal physiology and cancer, and the expression levels of the various HER receptors are critical determinants of clinical outcomes. HER activation is driven by the formation of various dimer complexes between members of this receptor family. The HER dimer types can have differential effects on downstream signaling and phenotypic outcomes. We constructed an integrated mathematical model of HER activation, and trafficking to quantitatively link receptor expression levels to dimerization and activation. We parameterized the model with a comprehensive set of HER phosphorylation and abundance data collected in a panel of human mammary epithelial cells expressing varying levels of EGFR/HER1, HER2 and HER3. Although parameter estimation yielded multiple solutions, predictions for dimer phosphorylation were in agreement with each other. We validated the model using experiments where pertuzumab was used to block HER2 dimerization. We used the model to predict HER dimerization and activation patterns in a panel of human mammary epithelial cells lines with known HER expression levels in response to stimulations with ligands EGF and HRG. Simulations over the range of expression levels seen in various cell lines indicate that: i) EGFR phosphorylation is driven by HER1-HER1 and HER1-HER2 dimers, and not HER1-HER3 dimers, ii) HER1-HER2 and HER2-HER3 dimers both contribute significantly to HER2 activation with the EGFR expression level determining the relative importance of these species, and iii) the HER2-HER3 dimer is largely responsible for HER3 activation. The model can be used to predict phosphorylated dimer levels for any given HER expression profile. This information in turn can be used to quantify the potencies of the various HER dimers, and can potentially inform personalized therapeutic approaches. PMID:23990774

  6. Executive Control Signals in Orbitofrontal Cortex during Response Inhibition

    PubMed Central

    2015-01-01

    Orbitofrontal cortex (OFC) lesions produce deficits in response inhibition and imaging studies suggest that activity in OFC is stronger on trials that require suppression of behavior, yet few studies have examined neural correlates at the single-unit level in a behavioral task that probes response inhibition without varying other factors, such as anticipated outcomes. Here we recorded from single neurons in lateral OFC in a task that required animals in the minority of trials to STOP or inhibit an ongoing movement and respond in the opposite direction. We found that population and single-unit firing was modulated primarily by response direction and movement speed, and that very few OFC neurons exhibited a response independent inhibition signal. Remarkably, the strength of the directional signal was not diminished on STOP trials and was actually stronger on STOP trials during conflict adaptation. Finally, directional signals were stronger during sessions in which rats had the most difficulty inhibiting behavior. These results suggest that “inhibition” deficits observed with OFC interference studies reflect deficits unrelated to signaling the need to inhibit behavior, but instead support a role for OFC in executive functions related to dissociating between two perceptually similar actions during response conflict. PMID:25740519

  7. Soy isoflavone genistein modulates cell cycle progression and induces apoptosis in HER-2/neu oncogene expressing human breast epithelial cells.

    PubMed

    Katdare, Meena; Osborne, Michael; Telang, Nitin T

    2002-10-01

    In the multistep progressive pathogenesis of human breast cancer, comedo ductal carcinoma in situ (DCIS) represents a preinvasive precursor lesion for therapy resistant invasive cancer. Human tissue derived cell culture models exhibiting molecular similarities to clinical DCIS facilitate an important preclinical mechanistic approach for evaluation of preventive efficacy of natural and synthetic chemopreventive compounds. Natural phytochemicals present in fresh fruits, vegetables and grain products are likely to offer protection against cancer. The clinical efficacy of these natural phytochemicals, however, depends on extrapolation, and is therefore equivocal. The present study determined whether the natural soy isoflavone genistein (GEN) inhibited aberrant proliferation in 184-B5/HER cells (a model for human comedo DCIS) and identified possible mechanisms responsible for its efficacy. Human reduction mammoplasty derived HER-2/neu oncogene expressing preneoplastic 184-B5/HER cells represented the experimental system. Flow cytometry and cellular epifluorescence based assays were utilized to quantitate the alterations in cell cycle progression, cellular apoptosis, and in the status of cell cycle regulatory and apoptosis-associated gene product expression. The 184-B5/HER cells exhibited specific immunofluorescence to p185HER, p53, EGFR, but not to ERalpha, thus resembling comedo DCIS. Treatment of 184-B5/HER cells with GEN resulted in a dose-dependent decrease in the viable cell population, increase in the G0/G1:S + G2/M ratio and enhancement of sub G0/G1 (apoptotic population). Exposure to the maximum cytostatic 10 microM dose of GEN down-regulated HER-2/neu mediated signal transduction as evidenced by a 73.9% decrease (p=0.001) in p185HER specific, and a 89.8% decrease (p=0.001) in phosphotyrosine specific immunofluorescence. The increase in G0/G1:S + G2/M ratio in response to the treatment with 10 microM GEN was associated with a 85.5% decrease (p=0.001) in

  8. Lapatinib inhibits CIP2A/PP2A/p-Akt signaling and induces apoptosis in triple negative breast cancer cells

    PubMed Central

    Liu, Chun-Yu; Hu, Ming-Hung; Hsu, Chia-Jung; Huang, Chun-Teng; Wang, Duen-Shian; Tsai, Wen-Chun; Chen, Yi-Ting; Lee, Chia-Han; Chu, Pei-Yi; Hsu, Chia-Chi; Chen, Ming-Huang; Shiau, Chung-Wai; Tseng, Ling-Ming; Chen, Kuen-Feng

    2016-01-01

    We tested the efficacy of lapatinib, a dual tyrosine kinase inhibitor which interrupts the HER2 and epidermal growth factor receptor (EGFR) pathways, in a panel of triple-negative breast cancer (TNBC) cells, and examined the drug mechanism. Lapatinib showed an anti-proliferative effect in HCC 1937, MDA-MB-468, and MDA-MB-231 cell lines. Lapatinib induced significant apoptosis and inhibited CIP2A and p-Akt in a dose and time-dependent manner in the three TNBC cell lines. Overexpression of CIP2A reduced lapatinib-induced apoptosis in MDA-MB-468 cells. In addition, lapatinib increased PP2A activity (in relation to CIP2A inhibition). Moreover, lapatinib-induced apoptosis and p-Akt downregulation was attenuated by PP2A antagonist okadaic acid. Furthermore, lapatinib indirectly decreased CIP2A transcription by disturbing the binding of Elk1 to the CIP2A promoter. Importantly, lapatinib showed anti-tumor activity in mice bearing MDA-MB-468 xenograft tumors, and suppressed CIP2A as well as p-Akt in these xenografted tumors. In summary, inhibition of CIP2A determines the effects of lapatinib-induced apoptosis in TNBC cells. In addition to being a dual tyrosine kinase inhibitor of HER2 and EGFR, lapatinib also inhibits CIP2A/PP2A/p-Akt signaling in TNBC cells. PMID:26824320

  9. The Metastasis Suppressor, N-MYC Downstream-regulated Gene-1 (NDRG1), Down-regulates the ErbB Family of Receptors to Inhibit Downstream Oncogenic Signaling Pathways.

    PubMed

    Kovacevic, Zaklina; Menezes, Sharleen V; Sahni, Sumit; Kalinowski, Danuta S; Bae, Dong-Hun; Lane, Darius J R; Richardson, Des R

    2016-01-15

    N-MYC downstream-regulated gene-1 (NDRG1) is a potent growth and metastasis suppressor that acts through its inhibitory effects on a wide variety of cellular signaling pathways, including the TGF-β pathway, protein kinase B (AKT)/PI3K pathway, RAS, etc. To investigate the hypothesis that its multiple effects could be regulated by a common upstream effector, the role of NDRG1 on the epidermal growth factor receptor (EGFR) and other members of the ErbB family, namely human epidermal growth factor receptor 2 (HER2) and human epidermal growth factor receptor 3 (HER3), was examined. We demonstrate that NDRG1 markedly decreased the expression and activation of EGFR, HER2, and HER3 in response to the epidermal growth factor (EGF) ligand, while also inhibiting formation of the EGFR/HER2 and HER2/HER3 heterodimers. In addition, NDRG1 also decreased activation of the downstream MAPKK in response to EGF. Moreover, novel anti-tumor agents of the di-2-pyridylketone class of thiosemicarbazones, namely di-2-pyridylketone 4,4-dimethyl-3-thiosemicarbazone and di-2-pyridylketone 4-cyclohexyl-4-methyl-3-thiosemicarbazone, which markedly up-regulate NDRG1, were found to inhibit EGFR, HER2, and HER3 expression and phosphorylation in cancer cells. However, the mechanism involved appeared dependent on NDRG1 for di-2-pyridylketone 4,4-dimethyl-3-thiosemicarbazone, but was independent of this metastasis suppressor for di-2-pyridylketone 4-cyclohexyl-4-methyl-3-thiosemicarbazone. This observation demonstrates that small structural changes in thiosemicarbazones result in marked alterations in molecular targeting. Collectively, these results reveal a mechanism for the extensive downstream effects on cellular signaling attributed to NDRG1. Furthermore, this study identifies a novel approach for the treatment of tumors resistant to traditional EGFR inhibitors. PMID:26534963

  10. Interleukin-2 enhances the natural killer cell response to Herceptin-coated Her2/neu-positive breast cancer cells.

    PubMed

    Carson, W E; Parihar, R; Lindemann, M J; Personeni, N; Dierksheide, J; Meropol, N J; Baselga, J; Caligiuri, M A

    2001-10-01

    The Her2/neu (c-erbB-2) oncogene encodes a 185-kDa protein tyrosine kinase which is overexpressed in 20% of breast adenocarcinomas and is recognized by a humanized anti-Her2/neu monoclonal antibody (mAb) (rhu4D5 or Herceptin). Natural killer (NK) cells are capable of mediating antibody-dependent cell cytotoxicity (ADCC) against antibody-coated targets via their expression of a low-affinity receptor for IgG (FcgammaRIII or CD16). NK cells can be expanded in cancer patients via the administration of low-dose interleukin-2 (IL-2) and become potent cytotoxic effectors following exposure to high doses of IL-2. We tested IL-2-activated NK cells against Her2/neu+ (MCF-7Her2/neu) and Her2/neu- (MDA-468) breast cancer cell lines in a 4-h 51Cr-release cytotoxicity assay in the presence or absence of rhu4D5 mAb (effector : target ratio = 10 : 1). Specific lysis of rhu4D5-coated MCF-7Her2/neu and MDA-468 target cells by IL-2-activated NK cells was 35% and 3%, respectively (p < 0.05). Lysis was less than 5% when targets were treated with either the non-humanized mu4D5 mAb or control huIgG. Lysis of rhu4D5-coated MCF-7Her2/neu cells was inhibited by 80 % when NK cells were pre-treated with an anti-Fc receptor antibody prior to use in the cytotoxicity assay. Enhanced ADCC of MCF-7Her2/neu target cells was seen when the effector cells consisted of mononuclear cells obtained from a patient demonstrating significant expansion of NK cells secondary to therapy with low-dose IL-2. Serum from patients receiving infusions of rhu4D5 mAb could substitute for exogenous antibody in the ADCC assay. NK cells activated by rhu4D5-coated tumor cells in the presence of IL-2 also produced large amounts of IFN-gamma with concomitant up-regulation of cell-surface activation markers CD25 and CD69. These results lend support to the concurrent use of rhu4D5 mAb and IL-2 therapy in patients with cancers that express the Her2/neu oncogene. PMID:11592078

  11. Detection of truncated HER2 forms in formalin-fixed, paraffin-embedded breast cancer tissue captures heterogeneity and is not affected by HER2-targeted therapy.

    PubMed

    Krüger, Juliane M; Thomas, Marlene; Korn, René; Dietmann, Gabriele; Rutz, Christoph; Brockhoff, Gero; Specht, Katja; Hasmann, Max; Feuerhake, Friedrich

    2013-08-01

    Truncated forms of HER2, previously identified in subsets of HER2-positive breast cancer, originate from proteolytic extracellular domain (ECD) cleavage or alternative translation initiation. They lack ECD but may retain intracellular domain functionality, potentially associated with unfavorable prognosis, metastasis, and decreased sensitivity to antibody-based HER2-targeted therapy. To study the distribution of truncated HER2 in breast cancer, we detected loss of membrane-bound ECD independently of its molecular origin in paraffin sections, combining multispectral unmixing of chromogenic duplex IHC for HER2 ECD and intracellular domain with advanced image analysis. HER2 C-terminal fragment 611-transfected MCF7 and 4-aminophenylmercuric acetate-treated SKBR3 cell lines were used as controls. Applying a prototype work flow to whole sections, paired surgical resection/core needle biopsy samples, and paired samples from 69 patients of a phase 2 neoadjuvant clinical trial, we observed unexpected heterogeneity of ECD loss at the single-cell level, and in different areas of individual tumors, indicating that extent and localization of HER2 ECD loss add relevant information to averaging truncated HER2 across whole sections. We show acceptable run-to-run variation (coefficient of variation, <0.15), image analysis results in moderate agreement with conventional slide assessment (Cohen's κ = 0.59), and no obvious interference with previous HER2-ECD-targeted therapy. We conclude that duplex IHC and digital image processing extend current approaches of truncated HER2 detection. PMID:23727348

  12. Identification of Targetable HER2 Aberrations in Head and Neck Squamous Cell Carcinoma

    PubMed Central

    Birkeland, Andrew C.; Yanik, Megan; Tillman, Brittny N.; Scott, Megan V.; Foltin, Susan K.; Mann, Jacqueline E.; Michmerhuizen, Nicole L.; Ludwig, Megan L.; Sandelski, Morgan M.; Komarck, Christine M.; Carey, Thomas E.; Prince, Mark E.P.; Bradford, Carol R.; McHugh, Jonathan B.; Spector, Matthew E.; Brenner, J. Chad

    2016-01-01

    Importance HER2 is an important drug target in breast cancer, where anti-HER2 therapy has been shown to lead to improvements in disease recurrence and overall survival. HER2 status in head and neck squamous cell carcinoma (HNSCC) has not been well studied. Identification of HER2 positive tumors and characterization of response to HER2 therapy could lead to targeted treatment options in HNSCC. Objective To identify HER2 aberrations in HNSCCs and investigate potential for HER2 targeted therapy in HNSCCs. Design, Setting, and Participants Retrospective case series of patients with laryngeal and oral cavity SCC enrolled in the University of MichiganSPORE. Publically available sequencing data(TCGA) was reviewed to identify additional mutations and overexpression in HER2 in HNSCC. Established HNSCC cell lines were used for follow-up in vitro analysis. Interventions Using targeted, amplicon-based sequencing with the Oncomine Cancer Panel, we assessed the copy number and mutation status of commonly altered genes in HNSCCs. Immunohistochemical staining was performed on tissue microarrays of HNSCCs to assess expression of HER2. Western blotting for HNSCC cell line HER2 expression, and cell survival assays after treatment with HER2 inhibitors were performed. Main Outcomes and Measures Prevalence of HER2 genetic aberrations and HER2 overexpression in laryngeal and oral cavity squamous cell carcinomas (SCCs). Prevalence of HER2 aberrations in HNSCC in TCGA. HER2 protein expression in HNSCC cell lines. Response of HNSCC cell lines to targeted HER2 inhibitors. Results Forty-two laryngeal SCC samples were screened by targeted sequencing, of which 4 were positive for HER2 amplification. Two samples identified with sequencing showed HER2 overexpression on immunohistochemistry. Two of 94 oral cavity SCC samples were positive for HER2 on immunohistochemistry. Analysis of 288 patients from publicly available HNSCC sequencing data revealed 9 amplifications in HER2. Protein expression

  13. Synergistic antitumor efficacy against the EGFRvIII+HER2+ breast cancers by combining trastuzumab with anti-EGFRvIII antibody CH12

    PubMed Central

    Zhang, Jiqin; Kong, Juan; Jiang, Hua; Tian, Mi; Li, Kesang; Wang, Biao; Chen, Cheng; Song, Fei; Pan, Xiaorong; Shi, Bizhi; Kong, Xianming; Gu, Jianren; Cai, Xiumei; Li, Zonghai

    2015-01-01

    Although Trastuzumab, an anti-HER2 antibody, benefits certain patients with HER2-overexpressing breast cancer, de novo or acquired trastuzumab resistance remains a haunting issue. EGFRvIII, co-expressing with HER2 in some breast tumors, indicates a poor clinical prognosis. However, the role of EGFRvIII in the function of trastuzumab is not clear. Here, we demonstrated that EGFRvIII overexpression contributed to de novo trastuzumab resistance and the feedback activation of STAT3 caused by trastuzumab also resulted in acquired resistance in EGFRvIII+HER2+ breast cancers. CH12, a highly effective anti-EGFRvIII monoclonal antibody that preferentially binds to EGFRvIII, significantly suppressed the growth of EGFRvIII+HER2+ breast cancer cells in vitro and in vivo. Importantly, CH12 in combination with trastuzumab had a synergistic inhibitory effect on EGFRvIII+HER2+ breast cancers in vitro and in vivo via attenuating the phosphorylation of EGFR and HER2 and their downstream signal pathways more effectively and reversing STAT3 feedback activation. Moreover, the combination therapy suppressed angiogenesis and induced cell apoptosis significantly. Together, these results suggested a synergistic efficacy of the combination of trastuzumab with CH12 against EGFRvIII+HER2+ breast cancers, which might be a potential clinical application in the future. PMID:26474285

  14. Signaling Delays Preclude Defects in Lateral Inhibition Patterning

    NASA Astrophysics Data System (ADS)

    Glass, David S.; Jin, Xiaofan; Riedel-Kruse, Ingmar H.

    2016-03-01

    Lateral inhibition represents a well-studied example of biology's ability to self-organize multicellular spatial patterns with single-cell precision. Despite established biochemical mechanisms for lateral inhibition (e.g., Delta-Notch), it remains unclear how cell-cell signaling delays inherent to these mechanisms affect patterning outcomes. We investigate a compact model of lateral inhibition highlighting these delays and find, remarkably, that long delays can ensure defect-free patterning. This effect is underscored by an interplay with synchronous oscillations, cis interactions, and signaling strength. Our results suggest that signaling delays, though previously posited as a source of developmental defects, may in fact be a general regulatory knob for tuning developmental robustness.

  15. Induction of HER2 Immunity in Outbred Domestic Cats by DNA Electrovaccination

    PubMed Central

    Gibson, Heather; Veenstra, Jesse; Jones, Richard; Vaishampayan, Ulka; Sauerbrey, Michele; Bepler, Gerold; Lum, Lawrence; Reyes, Joyce; Weise, Amy; Wei, Wei-Zen

    2015-01-01

    Domestic cats share human living environments and genetic traits. They develop spontaneous feline mammary carcinoma (FMC) with histopathology similar to human breast cancer. HER2 and AKT phosphorylation was demonstrated in primary FMC by immunoblot, indicating HER2 as a therapeutic target. FMC lines K12 and K248 expressing HER1, HER2 and HER3 were sensitive to receptor tyrosine kinase (RTK) inhibitors gefitinib and lapatinib. To test HER2 vaccine response in cats, purpose-bred, healthy cats were electrovaccinated with heterologous (xenogeneic) or point-mutated feline HER2 DNA. T-cell reactivity to feline self-HER2 was detected in 4 of 10 cats that received bear HER2, human/rat fusion HER2 (E2Neu) or mutant feline HER2 (feHER2-K) which contains a single amino acid substitution. The variable T-cell responses may resemble that in the genetically heterogeneous human population. All immune sera to heterologous HER2 recognized feline HER2 expressed in 3T3 cells (3T3/HER2), but not that in FMC K12 or K248. Immune sera to mutant pfeHER2-K bound 3T3/HER2 cells weakly, but they demonstrated better recognition of K12 and K248 cells that also express HER1 and HER3, suggesting distinct HER2 epitopes displayed by FMC that may be simulated by feHER2-K. In summary, HER2 DNA electroporation overcomes T-cell immune tolerance in ~40% healthy cats and induces antibodies with distinct specificity. Vaccination studies in domestic cats can expedite vaccine iteration to guide human vaccine design and better predict outcome, with the added benefit of helping feline mammary tumor patients. PMID:25711535

  16. Sasa health exerts a protective effect on Her2/NeuN mammary tumorigenesis.

    PubMed

    Ren, Mingqiang; Reilly, R Todd; Sacchi, Nicoletta

    2004-01-01

    Bamboo grass leaves of different Sasa species have been widely used in food and medicine in Eastern Asia for hundreds of years. Of special interest are Kumazasa (Sasa senanensis rehder) leaves used to prepare an alkaline extract known as Sasa Health. This extract was reported to inhibit both the development and growth of mammary tumors in a mammary tumor strain of virgin SHN mice (1). We found that Sasa Health exerts a significant protective effect on spontaneous mammary tumorigenesis in another mouse model of human breast cancer, the transgenic FVB-Her2/NeuN mouse model. Two cohorts of Her2/NeuN female mice of different age (eleven-week-old and twenty-four-week-old) chronically treated with Sasa Health in drinking water showed both a delay in the development of tumors and reduced tumor multiplicity. Sasa Health also induced inhibition of mammary duct branching and side bud development in association with reduced angiogenesis. Altogether these findings indicate that Sasa Health contains phytochemicals that can effectively retard spontaneous mammary tumorigenesis. PMID:15517891

  17. Correlation between HER-2/neu(erbB-2) expression level and therapeutic effect of combination treatment with HERCEPTIN and chemotherapeutic agents in gastric cancer cell lines

    PubMed Central

    2014-01-01

    Introduction Although advanced gastric cancer has many limitations and response rate is marginal in chemotherapy. Overexpression of human epidermal growth factor receptor 2(HER-2/neu) gene and its protein are associated with increased cell division and a high rate of tumor growth and have been reported in several malignancies. Especially, approximately 30% of breast cancer patients have overexpression of HER-2/neu protein and the overexpression metastasize faster, induces resistance of the chemotherapy and down-regulate function of estrogen receptor. Recombinant humanized anti-HER2 antibody (Herceptin) inhibits proliferation of HER-2/neu overexpressing tumor cells and the use of that in combination in metastatic breast cancer have increased cytotoxicity of chemotherapeutic agents. Methods We evaluated the expression of HER-2/neu protein in gastric cell lines by FACS and then comparing the cytotoxicity in chemotherapeutics (doxorubicin, cisplatin, paclitaxel, 5-FU) alone and in combination with Herceptin according to the expression of HER-2/neu protein by MTT assay. Results 1. NCI-N87 (88%) gastric cancer cell line and SK-BR-3 (89%) breast cancer cell line with strong positivity of HER-2/neu expression. YBC-2 (55%) and YBC-3 (48%) gastric cancer cell line with intermediated, weak positivity respectively. Negative control U-87 MG (6%) brain cancer cell line were showed low expression of HER-2/neu. 2. Cell growth was dose-dependently inhibited in HER-2/neu positive, control cell line SK-BR-3 by Herceptin treatment but not observed in HER-2/neu negative control cell line U-87 MG. Effective growth inhibition was not observed in gastric cancer cell lines with single treatment of Herceptin, all cell lines observed the dose-dependent growth inhibition to chemotherapeutic agents (doxorubicin, cisplatin, paclitaxel and 5-FU). 3. Combination of Herceptin with doxorubicin observed synergistic effects in all cancer cell lines except YBC-3, combination of Herceptin with

  18. Blood Genome-Wide Transcriptional Profiles of HER2 Negative Breast Cancers Patients

    PubMed Central

    Balacescu, Ovidiu; Balacescu, Loredana; Gherman, Claudia; Drigla, Flaviu; Pop, Laura; Bolba-Morar, Gabriela; Tudoran, Oana; Berindan-Neagoe, Ioana

    2016-01-01

    Tumors act systemically to sustain cancer progression, affecting the physiological processes in the host and triggering responses in the blood circulating cells. In this study, we explored blood transcriptional patterns of patients with two subtypes of HER2 negative breast cancers, with different prognosis and therapeutic outcome. Peripheral blood samples from seven healthy female donors and 29 women with breast cancer including 14 triple-negative breast cancers and 15 hormone-dependent breast cancers were evaluated by microarray. We also evaluated the stroma in primary tumors. Transcriptional analysis revealed distinct molecular signatures in the blood of HER2− breast cancer patients according to ER/PR status. Our data showed the implication of immune signaling in both breast cancer subtypes with an enrichment of these processes in the blood of TNBC patients. We observed a significant alteration of “chemokine signaling,” “IL-8 signaling,” and “communication between innate and adaptive immune cells” pathways in the blood of TNBC patients correlated with an increased inflammation and necrosis in their primary tumors. Overall, our data indicate that the presence of triple-negative breast cancer is associated with an enrichment of altered systemic immune-related pathways, suggesting that immunotherapy could possibly be synergistic to the chemotherapy, to improve the clinical outcome of these patients. PMID:26884644

  19. Quantitative detection of HER2 protein concentration in breast cancer tissue does not increase the number of patients eligible for adjuvant HER2-targeted therapy.

    PubMed

    Bechmann, Troels; Olsen, Dorte Aalund; Jakobsen, Erik Hugger; Madsen, Jonna Skov; Brandslund, Ivan; Jylling, Anne Marie Bak; Steffensen, Karina Dahl; Jakobsen, Anders

    2013-04-01

    Human epidermal growth factor receptor-2 (HER2) is overexpressed in 15-20% of breast cancer patients and is associated with an aggressive tumor and a poor prognosis. Currently, patients are selected for adjuvant HER2-targeted therapy based on HER2 status by immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH). In this study, we assessed the clinical significance of tissue HER2 status determined by a quantitative immunoassay using ADVIA Centaur. We investigated the hypothesis that the clinical outcome is worse in a group of patients defined as tissue HER2-positive only by Centaur, but not treated with adjuvant HER2-targeted therapy, compared to patients defined as HER2-positive by IHC/FISH and therefore treated with adjuvant HER2-targeted therapy. Tumor tissue was obtained at primary surgery from 415 breast cancer patients between 2004 and 2010. HER2 status was determined by quantitative immunoassay of fresh-frozen tissue and by IHC/FISH of corresponding paraffin-embedded tissue. We compared the clinical outcome in four groups of patients defined by tissue HER2 status and adjuvant HER2-targeted therapy. The final analysis included 379 patients after a median follow-up of 3.9 years for invasive disease-free survival (IDFS) and 4.2 years for overall survival (OS). The quantitative Centaur assay defined a greater number of patients (100 patients, 26.4%) as HER2-positive than IHC/FISH (63 patients, 16.6%) (P<0.0001). No significant difference in IDFS (P=0.159) and OS (P=0.150) was observed among the four groups of patients. However, in the IHC/FISH-positive group without adjuvant HER2-targeted therapy (group 2), a significantly greater number of events was found compared to the Centaur-positive group without adjuvant HER2-targeted therapy (group 3) for both IDFS (P=0.025) and OS (P=0.020). Quantitative HER2 determination by Centaur did not define a new group of patients eligible for HER2-targeted therapy. Currently, tissue HER2 status defined

  20. Accurate sensitivity of quantum dots for detection of HER2 expression in breast cancer cells and tissues.

    PubMed

    Tabatabaei-Panah, Akram-Sadat; Jeddi-Tehrani, Mahmood; Ghods, Roya; Akhondi, Mohammad-Mehdi; Mojtabavi, Nazanin; Mahmoudi, Ahmad-Reza; Mirzadegan, Ebrahim; Shojaeian, Sorour; Zarnani, Amir-Hassan

    2013-03-01

    Here we introduce novel optical properties and accurate sensitivity of Quantum dot (QD)-based detection system for tracking the breast cancer marker, HER2. QD525 was used to detect HER2 using home-made HER2-specific monoclonal antibodies in fixed and living HER2(+) SKBR-3 cell line and breast cancer tissues. Additionally, we compared fluorescence intensity (FI), photostability and staining index (SI) of QD525 signals at different exposure times and two excitation wavelengths with those of the conventional organic dye, FITC. Labeling signals of QD525 in both fixed and living breast cancer cells and tissue preparations were found to be significantly higher than those of FITC at 460-495 nm excitation wavelengths. Interestingly, when excited at 330-385 nm, the superiority of QD525 was more highlighted with at least 4-5 fold higher FI and SI compared to FITC. Moreover, QDs exhibited exceptional photostability during continuous illumination of cancerous cells and tissues, while FITC signal faded very quickly. QDs can be used as sensitive reporters for in situ detection of tumor markers which in turn could be viewed as a novel approach for early detection of cancers. To take comprehensive advantage of QDs, it is necessary that their optimal excitation wavelength is employed. PMID:23212129

  1. The HER2 amplicon includes several genes required for the growth and survival of HER2 positive breast cancer cells — A data description

    PubMed Central

    Hongisto, Vesa; Aure, Miriam Ragle; Mäkelä, Rami; Sahlberg, Kristine Kleivi

    2014-01-01

    A large number of breast cancers are characterized by amplification and overexpression of the chromosome segment surrounding the HER2 (ERBB2) oncogene. As the HER2 amplicon at 17q12 contains multiple genes, we have systematically explored the role of the HER2 co-amplified genes in breast cancer cell growth and their relation to trastuzumab resistance. We integrated array comparative genomic hybridization (aCGH) data of the HER2 amplicon from 71 HER2 positive breast tumors and 10 cell lines with systematic functional RNA interference analysis of 23 core amplicon genes with several phenotypic endpoints in a panel of trastuzumab responding and non-responding HER2 positive breast cancer cells. In this Data in Brief we give a detailed description of the experimental procedures and the data analysis methods used in the study (1). PMID:26484103

  2. hMENA(11a) contributes to HER3-mediated resistance to PI3K inhibitors in HER2-overexpressing breast cancer cells.

    PubMed

    Trono, P; Di Modugno, F; Circo, R; Spada, S; Di Benedetto, A; Melchionna, R; Palermo, B; Matteoni, S; Soddu, S; Mottolese, M; De Maria, R; Nisticò, P

    2016-02-18

    Human Mena (hMENA), an actin regulatory protein of the ENA/VASP family, cooperates with ErbB receptor family signaling in breast cancer. It is overexpressed in high-risk preneoplastic lesions and in primary breast tumors where it correlates with HER2 overexpression and an activated status of AKT and MAPK. The concomitant overexpression of hMENA and HER2 in breast cancer patients is indicative of a worse prognosis. hMENA is expressed along with alternatively expressed isoforms, hMENA(11a) and hMENAΔv6 with opposite functions. A novel role for the epithelial-associated hMENA(11a) isoform in sustaining HER3 activation and pro-survival pathways in HER2-overexpressing breast cancer cells has been identified by reverse phase protein array and validated in vivo in a series of breast cancer tissues. As HER3 activation is crucial in mechanisms of cell resistance to PI3K inhibitors, we explored whether hMENA(11a) is involved in these resistance mechanisms. The specific hMENA(11a) depletion switched off the HER3-related pathway activated by PI3K inhibitors and impaired the nuclear accumulation of HER3 transcription factor FOXO3a induced by PI3K inhibitors, whereas PI3K inhibitors activated hMENA(11a) phosphorylation and affected its localization. At the functional level, we found that hMENA(11a) sustains cell proliferation and survival in response to PI3K inhibitor treatment, whereas hMENA(11a) silencing increases molecules involved in cancer cell apoptosis. As shown in three-dimensional cultures, hMENA(11a) contributes to resistance to PI3K inhibition because its depletion drastically reduced cell viability upon treatment with PI3K inhibitor BEZ235. Altogether, these results indicate that hMENA(11a) in HER2-overexpressing breast cancer cells sustains HER3/AKT axis activation and contributes to HER3-mediated resistance mechanisms to PI3K inhibitors. Thus, hMENA(11a) expression can be proposed as a marker of HER3 activation and resistance to PI3K inhibition therapies, to

  3. KHF16 is a Leading Structure from Cimicifuga foetida that Suppresses Breast Cancer Partially by Inhibiting the NF-κB Signaling Pathway

    PubMed Central

    Kong, Yanjie; Li, Fubin; Nian, Yin; Zhou, Zhongmei; Yang, Runxiang; Qiu, Ming-Hua; Chen, Ceshi

    2016-01-01

    Triterpenoids extracted from Cimicifuga foetida have been reported to inhibit cancer by inducing cell cycle arrest and apoptosis. In this study, KHF16 (24-acetylisodahurinol-3-O-β-D-xylopyranoside), a cycloartane triterpenoid isolated from the rhizomes of C. foetida, showed potent anti-cancer activity in multiple ERα/PR/HER2 triple-negative breast cancer (TNBC) cell lines. KHF16 significantly induces cell cycle G2/M phase arrest and apoptosis in both MDA-MB-468 and SW527 TNBC cell lines. KHF16 reduces the expression levels of XIAP, Mcl-1, Survivin and Cyclin B1/D1 proteins. Importantly, KHF16 inhibits TNFα-induced IKKα/β phosphorylation, IKBα phosphorylation, p65 nuclear translocation and NF-κB downstream target gene expression, including XIAP, Mcl-1 and Survivin, in TNBC cells. These results suggest that KHF16 may inhibit TNBC by blocking the NF-κB signaling pathway in part. PMID:27162557

  4. Marked heterogeneity of HER2/NEU gene amplification in endometrial serous carcinoma.

    PubMed

    Buza, Natalia; Hui, Pei

    2013-12-01

    Significant heterogeneity of HER2 protein expression has been recently observed in HER2 positive endometrial serous carcinomas. Tumor cells with HER2 overexpression and/or gene amplification in a heterogeneous tumor may represent a biologically more aggressive subclone that is clinically relevant to prognosis and potential targeted therapy. To correlate with HER2 protein heterogeneity, we investigated the heterogeneity of HER2/NEU gene amplification in endometrial serous carcinoma. A total of 17 endometrial serous carcinomas with heterogeneous HER2 protein expression were selected for the study, including nine cases with a 3+ and eight cases with a 2+ immunohistochemical score. Initial reflex HER2 FISH was available for seven of the eight 2+ cases, five of which showed HER2/NEU gene amplification. All 17 cases underwent repeat FISH targeting larger tumor tissue areas. Ten cases (72%) displayed striking heterogeneity of HER2/NEU gene copy number in the form of cluster amplification. Diffuse HER2 amplification was observed in four cases, no amplification was seen in three tumors. In cases with cluster amplification, HER2 protein overexpression by immunohistochemistry closely correlated at the cellular level with HER2/NEU gene amplification. In conclusion, the significant percentage of cases with heterogeneous HER2/NEU gene amplification indicates that the existing HER2 testing guidelines designed for breast cancer may not be applicable to endometrial serous carcinoma. Clinical testing on multiple different tumor samples or large tumor tissue sections is recommended for both immunohistochemistry and FISH assessment of HER2 status. Direct comparison with the HER2 immunostaining pattern may be helpful in detecting HER2 amplified areas in a heterogeneous tumor. PMID:24123408

  5. HER2 heterogeneity in gastric/gastroesophageal cancers: From benchside to practice

    PubMed Central

    Grillo, Federica; Fassan, Matteo; Sarocchi, Francesca; Fiocca, Roberto; Mastracci, Luca

    2016-01-01

    HER2 is overexpressed in approximately 10%-20% of gastric and gastroesophageal junction carcinomas. In these types of cancer, accurate assessment of HER2 status is mandatory, for selecting patients who may benefit from targeted therapies with anti-HER2 drugs such as Trastuzumab. This manuscript focuses on HER2 in gastric carcinogenesis, on optimal evaluation of HER2 and on the possible causes which may contribute to inaccurate HER2 evaluation. Similarly to breast cancer HER2 evaluation, standardization of HER2 testing in gastric cancer is necessary in diagnostic practice. The three principle aspects which require consideration are: (1) the choice of sample with regards to cancer morphology - intestinal vs diffuse areas; (2) the choice of scoring criteria - use of HER2 scoring criteria specific for gastric cancer; and (3) the choice of HER2 evaluation methods - use of an algorithm in which both immunohistochemistry and in situ hybridization play a role. Problematic issues include: (1) pre-analytic variables with particular emphasis on fixation; (2) recommended methodology for HER2 assessment (immunohistochemistry vs in situ hybridization); (3) HER2 heterogeneity both within the primary tumor and between primary tumor and metastases; (4) reliability of biopsies in HER 2 evaluation; and (5) quantity of sample (FFPE blocks from surgical specimens or endoscopic biopsies) necessary for an adequate assessment. PMID:27468182

  6. A systematic analysis of the resistance and sensitivity of HER2YVMA receptor tyrosine kinase mutant to tyrosine kinase inhibitors in HER2-positive lung cancer.

    PubMed

    Shen, Xiaokun; Chen, Beibei; Ma, Zhaosheng; Xie, Bojian; Cao, Xinguang; Yang, Tiejun; Zhao, Yuzhou; Qin, Jianjun; Li, Jicheng; Cao, Feilin; Chen, Xiaobing

    2016-01-01

    Human epidermal growth factor receptor 2 (HER2) has become a well-established target for the treatment of HER2-positive lung cancer. However, a frequently observed in-frame mutation that inserts amino acid quadruplex Tyr776-Val777-Met778-Ala779 at G776 (G776(YVMA)) in HER2 kinase domain can cause drug resistance and sensitivity, largely limiting the application of reversible tyrosine kinase inhibitors in lung cancer therapy. A systematic investigation of the intermolecular interactions between the HER2(YVMA) mutant and clinical small-molecule inhibitors would help to establish a complete picture of drug response to HER2 G776(YVMA) insertion in lung cancer, and to design new tyrosine kinase inhibitors with high potency and selectivity to target the lung cancer-related HER2(YVMA) mutant. Here, we combined homology modeling, ligand grafting, structure minimization, molecular simulation and binding affinity analysis to profile a number of tyrosine kinase inhibitors against the G776(YVMA) insertion in HER2. It is found that the insertion is far away from HER2 active pocket and thus cannot contact inhibitor ligand directly. However, the insertion is expected to induce marked allosteric effect on some regions around the pocket, including A-loop and hinges connecting between the N- and C-lobes of HER2 kinase domain, which may exert indirect influence to inhibitor binding. Most investigated inhibitors exhibit weak binding strength to both wild-type and mutant HER2, which can be attributed to steric hindrance that impairs ligand compatibility with HER2 active pocket. However, the cognate inhibitor lapatinib and the non-cognate inhibitor bosutinib were predicted to have low affinity for wild-type HER2 but high affinity for HER2(YVMA) mutant, which was confirmed by subsequent kinase assay experiments; the inhibitory potencies of bosutinib against wild-type and mutant HER2 were determined to be IC(50) > 1000 and =27 nM, respectively, suggesting that the bosutinib might be

  7. Anti-Tumor Effects of Peptide Therapeutic and Peptide Vaccine Antibody Co-targeting HER-1 and HER-2 in Esophageal Cancer (EC) and HER-1 and IGF-1R in Triple-Negative Breast Cancer (TNBC)

    PubMed Central

    Overholser, Jay; Ambegaokar, Kristen Henkins; Eze, Siobhan M.; Sanabria-Figueroa, Eduardo; Nahta, Rita; Bekaii-Saab, Tanios; Kaumaya, Pravin T.P.

    2015-01-01

    Despite the promise of targeted therapies, there remains an urgent need for effective treatment for esophageal cancer (EC) and triple-negative breast cancer (TNBC). Current FDA-approved drugs have significant problems of toxicity, safety, selectivity, efficacy and development of resistance. In this manuscript, we demonstrate that rationally designed peptide vaccines/mimics are a viable therapeutic strategy for blocking aberrant molecular signaling pathways with high affinity, specificity, potency and safety. Specifically, we postulate that novel combination treatments targeting members of the EGFR family and IGF-1R will yield significant anti-tumor effects in in vitro models of EC and TNBC possibly overcoming mechanisms of resistance. We show that the combination of HER-1 and HER-2 or HER-1 and IGF-1R peptide mimics/vaccine antibodies exhibited enhanced antitumor properties with significant inhibition of tumorigenesis in OE19 EC and MDA-MB-231 TNBC cell lines. Our work elucidates the mechanisms of HER-1/IGF-1R and HER-1/HER-2 signaling in these cancer cell lines, and the promising results support the rationale for dual targeting with HER-1 and HER-2 or IGF-1R as an improved treatment regimen for advanced therapy tailored to difference types of cancer. PMID:26350593

  8. Anti-Tumor Effects of Peptide Therapeutic and Peptide Vaccine Antibody Co-targeting HER-1 and HER-2 in Esophageal Cancer (EC) and HER-1 and IGF-1R in Triple-Negative Breast Cancer (TNBC).

    PubMed

    Overholser, Jay; Ambegaokar, Kristen Henkins; Eze, Siobhan M; Sanabria-Figueroa, Eduardo; Nahta, Rita; Bekaii-Saab, Tanios; Kaumaya, Pravin T P

    2015-01-01

    Despite the promise of targeted therapies, there remains an urgent need for effective treatment for esophageal cancer (EC) and triple-negative breast cancer (TNBC). Current FDA-approved drugs have significant problems of toxicity, safety, selectivity, efficacy and development of resistance. In this manuscript, we demonstrate that rationally designed peptide vaccines/mimics are a viable therapeutic strategy for blocking aberrant molecular signaling pathways with high affinity, specificity, potency and safety. Specifically, we postulate that novel combination treatments targeting members of the EGFR family and IGF-1R will yield significant anti-tumor effects in in vitro models of EC and TNBC possibly overcoming mechanisms of resistance. We show that the combination of HER-1 and HER-2 or HER-1 and IGF-1R peptide mimics/vaccine antibodies exhibited enhanced antitumor properties with significant inhibition of tumorigenesis in OE19 EC and MDA-MB-231 TNBC cell lines. Our work elucidates the mechanisms of HER-1/IGF-1R and HER-1/HER-2 signaling in these cancer cell lines, and the promising results support the rationale for dual targeting with HER-1 and HER-2 or IGF-1R as an improved treatment regimen for advanced therapy tailored to difference types of cancer. PMID:26350593

  9. HER Story: The Next Chapter in HER-2-Directed Therapy for Advanced Breast Cancer

    PubMed Central

    Joy, Anil A.; Rayson, Daniel; McLeod, Deanna; Brezden-Masley, Christine; Boileau, Jean-François; Gelmon, Karen A.

    2013-01-01

    Untreated human epidermal growth factor receptor-2 (HER-2)-positive advanced breast cancer (ABC) is an aggressive disease, associated with a poor prognosis and short overall survival. HER-2-directed therapy prolongs both time to disease progression and overall survival when combined with chemotherapy and has become the standard of care for those with HER-2-positive breast cancer in the early and advanced settings. Despite the remarkable therapeutic impact HER-2-directed therapy has had on disease outcomes, some patients with HER-2-positive disease will have primary resistant disease and others will respond initially but will eventually have progression, underscoring the need for other novel therapeutic options. This article reviews recent phase III trial data and discusses a practical approach to sequencing of HER-2-directed therapy in patients with HER-2-positive ABC. The significant cumulative survival gains seen in these trials are slowly reshaping the landscape of HER-2-positive ABC outcomes. PMID:24212500

  10. HER story: the next chapter in HER-2-directed therapy for advanced breast cancer.

    PubMed

    Verma, Sunil; Joy, Anil A; Rayson, Daniel; McLeod, Deanna; Brezden-Masley, Christine; Boileau, Jean-François; Gelmon, Karen A

    2013-01-01

    Untreated human epidermal growth factor receptor-2 (HER-2)-positive advanced breast cancer (ABC) is an aggressive disease, associated with a poor prognosis and short overall survival. HER-2-directed therapy prolongs both time to disease progression and overall survival when combined with chemotherapy and has become the standard of care for those with HER-2-positive breast cancer in the early and advanced settings. Despite the remarkable therapeutic impact HER-2-directed therapy has had on disease outcomes, some patients with HER-2-positive disease will have primary resistant disease and others will respond initially but will eventually have progression, underscoring the need for other novel therapeutic options. This article reviews recent phase III trial data and discusses a practical approach to sequencing of HER-2-directed therapy in patients with HER-2-positive ABC. The significant cumulative survival gains seen in these trials are slowly reshaping the landscape of HER-2-positive ABC outcomes. PMID:24212500

  11. Lapatinib for the treatment of HER2-overexpressing breast cancer.

    PubMed

    Jones, J; Takeda, A; Picot, J; von Keyserlingk, C; Clegg, A

    2009-10-01

    This paper presents a summary of the evidence review group (ERG) report into the clinical effectiveness and cost-effectiveness of lapatinib for the treatment of advanced or metastatic HER2-overexpressing breast cancer based upon a review of the manufacturer's submission to the National Institute for Health and Clinical Excellence (NICE) as part of the single technology appraisal (STA) process. The scope included women with advanced, metastatic or recurrent HER2-overexpressing breast cancer who have had previous therapy that includes trastuzumab. Outcomes were time to progression, progression-free survival, response rates, overall survival, health-related quality of life and adverse effects. The submission's evidence came from one randomised controlled trial (RCT) of reasonable methodological quality, although it was not powered to detect a statistically significant difference in mean overall survival. Median time to progression was longer in the lapatinib plus capecitabine arm than in the capecitabine monotherapy arm {27.1 [95% confidence interval (CI) 17.4 to 49.4] versus 18.6 [95% CI 9.1 to 36.9] weeks; hazard ratio 0.57 [95% CI 0.43 to 0.77; p = 0.00013]}. Median overall survival was very similar between the groups [67.7 (95% CI 58.9 to 91.6) versus 66.6 (95% CI 49.1 to 75.0) weeks; hazard ratio 0.78 (95% CI 0.55 to 1.12; p = 0.177)]. Median progression-free survival was statistically significantly longer in the lapatinib plus capecitabine group than in the capecitabine monotherapy group [27.1 (95% CI 24.1 to 36.9) versus 17.6 (95% CI 13.3 to 20.1) weeks; hazard ratio 0.55 (95% CI 0.41 to 0.74); p = 0.000033]. The manufacturer's economic model to estimate progression-free and overall survival for patients with HER2-positive advanced/metastatic breast cancer who had relapsed following treatment with an anthracycline, a taxane and trastuzumab was appropriate for the disease area. The base-case incremental cost-effectiveness ratios (ICERs) for lapatinib plus

  12. Protective effect of naturally occurring anti-HER2 autoantibodies on breast cancer.

    PubMed

    Tabuchi, Yukiko; Shimoda, Masafumi; Kagara, Naofumi; Naoi, Yasuto; Tanei, Tomonori; Shimomura, Atsushi; Shimazu, Kenzo; Kim, Seung Jin; Noguchi, Shinzaburo

    2016-05-01

    Anti-HER2-autoantibodies (HER2-AAbs) are found in breast cancer patients as well as healthy individuals. However, the clinical relevance of the antibodies is unknown. We established an enzyme-linked immunosorbent assay with high sensitivity and quantified serum HER2-AAbs in 100 healthy women, 100 untreated patients with ductal carcinoma in situ (DCIS), and 500 untreated patients with invasive breast carcinoma (IBC). The associations between the levels of HER2-AAbs and breast cancer risk, and recurrence-free survival, were examined. High levels of HER2-AAbs were significantly associated with a reduced risk of DCIS (odds ratio [OR] 0.19, P = 4.6 × 10(-7)) or IBC (OR 0.31, P = 3.7 × 10(-7)). Subgroup analysis of IBC revealed a stronger association of HER2-AAbs with a reduced risk of the hormone receptor (HR)(-)/HER2(+) subtype (OR 0.12) than the other subtypes (HR(+)/HER2(-) [OR = 0.32], HR(+)/HER2(+) [OR 0.38], and HR(-)/HER2(-) [OR 0.29]). When we set the cutoff of HER2-AAbs at 20 ng/mL, recurrence-free survival of HER2-AAb-positive patients (N = 74) was significantly better than that of HER2-AAb-negative patients (N = 426) (P = 0.015). Univariate and multivariate analyses demonstrated that HER2-AAbs, as well as histological grade, were independently and significantly (P = 0.0065 and 0.049, respectively) associated with recurrence-free survival. Our exploratory study suggests a protective effect of naturally occurring HER2-AAbs on the development of primary and recurrent breast cancer. Further studies on HER2-AAbs are warranted. PMID:27113738

  13. Discovery of new human epidermal growth factor receptor-2 (HER2) inhibitors for potential use as anticancer agents via ligand-based pharmacophore modeling.

    PubMed

    Zalloum, Hiba; Tayyem, Rabab; Irmaileh, Basha'er Abu-; Bustanji, Yasser; Zihlif, Malek; Mohammad, Mohammad; Rjai, Talal Abu; Mubarak, Mohammad S

    2015-09-01

    To discover potential antitumor agents directed toward human epidermal growth factor receptor-2HER2/ErbB2 overexpression in cancer, we have explored the pharmacophoric space of 115 HER2/ErbB2 inhibitors. This identified 240 pharmacophores which were subsequently clustered into 20 groups and cluster centers were used as 3D-pharmacophoric descriptors in QSAR analysis with 2D-physicochemical descriptors to select the optimal combination. We were obliged to use ligand efficiency as the response variable because the logarithmic transformation of bioactivities failed to access self-consistent QSAR models. Two binding pharmacophore models emerged in the optimal QSAR equation, suggesting the existence of distinct binding modes accessible to ligands within the HER2/ErbB2 binding pocket. The QSAR equation and its associated pharmacophore models were employed to screen the National Cancer Institute (NCI) and Drug Bank databases to search for new, promising, and structurally diverse HER2 inhibitory leads. Inhibitory activities were tested against HER2-overexpressing SKOV3 Ovarian cancer cell line and MCF-7 which express low levels of HER2. In silico mining identified 80 inhibitors out of which four HER2 selective compounds inhibited the growth of SKOV3 cells with IC50 values < 5μM and with virtually no effect in MCF-7 cells. These lead compounds are excellent candidates for further optimization. PMID:26188796

  14. Fully human HER2/cluster of differentiation 3 bispecific antibody triggers potent and specific cytotoxicity of T lymphocytes against breast cancer.

    PubMed

    Zhou, Yan; Gou, Lan-Tu; Guo, Zhi-Hui; Liu, Hai-Rong; Wang, Jiang-Man; Zhou, Shu-Xian; Yang, Jin-Liang; Li, Xiao-An

    2015-07-01

    The use of a bispecific antibody (BsAb) is a promising and highly specific approach to cancer therapy. In the present study, a fully human recombinant single chain variable fragment BsAb against human epidermal growth factor receptor (HER)2 and cluster of differentiation (CD)3 was constructed with the aim of developing an effective treatment for breast cancer. HER2/CD3 BsAb was expressed in Chinese hamster ovary cells and purified via nickel column chromatography. Flow cytometry revealed that the HER2/CD3 BsAb was able to specifically bind to HER2 and CD3‑positive cells. HER2/CD3 BsAb was able to stimulate T-cell activation and induce the lysis of cultured SKBR‑3 and BT474 cells in the presence of unstimulated T lymphocytes. HER2/CD3 BsAb efficiently inhibited the growth of breast cancer tissue by activating and inducing the proliferation of tumor tissue infiltrating lymphocytes. Therefore, HER2/CD3 BsAb is a potent tool which may be a suitable candidate for the treatment of breast cancer. PMID:25760691

  15. EGFR/HER2 inhibitors effectively reduce the malignant potential of MDR breast cancer evoked by P-gp substrates in vitro and in vivo.

    PubMed

    Jin, Yiting; Zhang, Wei; Wang, Hongying; Zhang, Zijing; Chu, Chengyu; Liu, Xiuping; Zou, Qiang

    2016-02-01

    Multidrug resistance (MDR) induced by chemotherapy in breast cancer frequently leads to tumor invasion, metastasis and poor clinical outcome. We preliminarily found that the epidermal growth factor receptor (EGFR) is involved in enhancing the malignant potential of MDR breast cancer cells, but the mechanism remains unclear. In the present study, we demonstrated in vitro and in vivo that EGFR/HER2 promote the invasive and metastatic abilities of MDR breast cancer. More importantly, a new function of EGFR/HER2 inhibitors was revealed for the first time, which could improve the treatment efficacy of breast cancer by reversing the MDR process rather than by inhibiting tumor growth. Firstly, using quantitative real‑time PCR and western blot analysis, we found that overexpression of EGFR/HER2 in MCF7/Adr cells upregulated CD147 and MMP2/9 at both the transcription and protein expression levels, which promoted tumor cell migration, as determined using an in vitro invasion assay. Secondly, the upregulated levels of CD147 and MMP2/9 were decreased when EGFR/HER2 activity was inhibited, and therefore tumor invasion was also significantly inhibited. These phenomena were also demonstrated in nude mouse assays. Additionally, in MDR breast cancer patients, we found that overexpression of EGFR and P‑gp levels led to shorter overall survival (OS) and disease‑free survival (DFS) by IHC assays and Kaplan‑Meier survival analysis. In conclusion, EGFR/HER2 play a crucial role in enhancing CD147 and MMP expression to establish favorable conditions for invasion/metastasis in MDR breast cancer. The scope of application of EGFR/HER2 inhibitors may be expanded in EGFR/HER2‑positive patients. We suggest that MDR breast cancer patients may benefit from novel therapies targeting EGFR/HER2. PMID:26718028

  16. Even With Very Small Breast Tumors, Studies Find HER2 Status Matters | Division of Cancer Prevention

    Cancer.gov

    Two retrospective studies have found that women with HER2-positive breast tumors (that is, tumors that produce too much of the HER2 protein) that are 1 centimeter or smaller had a higher risk of their disease returning within 5 years than women with similarly small HER2-negative tumors. |

  17. Trastuzumab-mediated selective delivery for platinum drug to HER2-positive breast cancer cells.

    PubMed

    Huang, Rong; Sun, Yu; Gao, Qihe; Wang, Qiucui; Sun, Baiwang

    2015-10-01

    Oxaliplatin is used widely as an anticancer drug for clinical treatment. However, its applications are limited because of its poor selectivity. In this work, we described the design, synthesis, and characterization of conjugates combining trastuzumab with a platinum (IV) analog of oxaliplatin, in which the trastuzumab acted as an active targeting agent for HER2-positive cancer cells. Indirect enzyme-linked immunosorbent assay and immunofluorescence study indicated the platinum (IV)-trastuzumab conjugates retained specific binding activity to HER2 overexpressed SK-BR-3 cells. In the presence of ascorbic acid, platinum (IV)-trastuzumab conjugates were reduced to platinum (II) analogs, which could bind to and unwind PUC19 DNA in a manner similar to oxaliplatin. The cytotoxic study was tested on three breast cell lines: SK-BR-3, MCF-7, and MDA-MB-231. Platinum (IV)-trastuzumab conjugates showed promising antiproliferative activity against SK-BR-3 cells, but significantly decreased the inhibition to MDA-MB-231 and MCF-7 cells. The flow cytometric analysis showed that the conjugates arrested the cell cycle mainly at the G2/M phase and killed the cells through an apoptotic pathway. PMID:26186063

  18. Her2+ and b-HCG Producing Undifferentiated Gastric Adenocarcinoma

    PubMed Central

    Eivaz-Mohammadi, Sahar; Tarar, Omer; Malik, Khurram; Syed, Amer K.

    2014-01-01

    A 25-year-old Hispanic female with a history of anemia, schizoaffective disorder, and psychosis was admitted for anemia associated with fatigue, weakness, shortness of breath, night sweats, weight loss, and abdominal and lower back pain for the past two months. On routine management, she was found to have a positive serum b-HCG of 80.4 (0–5 mIU/mL) but the patient denied any sexual activity in her life. During her admission, U/S of the pelvis was noncontributory. CT angiogram of the chest was significant for prominent mediastinal and hilar lymph nodes, diffusely thickened stomach suggesting gastric malignancy with multiple hypoenhancing lesions in the liver and diffuse lytic lesions in the spine and sacrum suspicious for metastatic disease. The MRI of the abdomen confirmed the CT angiogram findings. After these findings, EGD was performed which showed lesions in the antrum, body of the stomach, fundus, and cardia on the lesser curvature of the stomach body correlating with carcinoma. The biopsy was positive for Her2, b-HCG producing poorly differentiated gastric adenocarcinoma. Patient underwent one successful round of chemotherapy with Taxotene, Cisplatin, and 5-FU for Stage IV gastric adenocarcinoma. PMID:25349615

  19. The HER2-Binding Affibody Molecule (ZHER2∶342)2 Increases Radiosensitivity in SKBR-3 Cells

    PubMed Central

    Ekerljung, Lina; Lennartsson, Johan; Gedda, Lars

    2012-01-01

    We have previously shown that the HER2-specific affibody molecule (ZHER2∶342)2 inhibits proliferation of SKBR-3 cells. Here, we continue to investigate its biological effects in vitro by studying receptor dimerization and clonogenic survival following irradiation. We found that (ZHER2∶342)2 sensitizes the HER2-overexpressing cell line SKBR-3 to ionizing radiation. The survival after exposure to (ZHER2∶342)2 and 8 Gy (S8Gy 0.006) was decreased by a factor four compared to the untreated (S8Gy 0.023). The low HER2-expressing cell line MCF-7 was more radiosensitive than SKBR-3 but did not respond to (ZHER2∶342)2. Treatment by (ZHER2∶342)2 strongly increased the levels of dimerized and phosphorylated HER2 even after 5 minutes of stimulation. The monomeric ZHER2∶342 does not seem to be able to induce receptor phosphorylation and dimerization or sensitize cells to irradiation. PMID:23166716

  20. ATR inhibition rewires cellular signaling networks induced by replication stress.

    PubMed

    Wagner, Sebastian A; Oehler, Hannah; Voigt, Andrea; Dalic, Denis; Freiwald, Anja; Serve, Hubert; Beli, Petra

    2016-02-01

    The slowing down or stalling of replication forks is commonly known as replication stress and arises from multiple causes such as DNA lesions, nucleotide depletion, RNA-DNA hybrids, and oncogene activation. The ataxia telangiectasia and Rad3-related kinase (ATR) plays an essential role in the cellular response to replication stress and inhibition of ATR has emerged as therapeutic strategy for the treatment of cancers that exhibit high levels of replication stress. However, the cellular signaling induced by replication stress and the substrate spectrum of ATR has not been systematically investigated. In this study, we employed quantitative MS-based proteomics to define the cellular signaling after nucleotide depletion-induced replication stress and replication fork collapse following ATR inhibition. We demonstrate that replication stress results in increased phosphorylation of a subset of proteins, many of which are involved in RNA splicing and transcription and have previously not been associated with the cellular replication stress response. Furthermore, our data reveal the ATR-dependent phosphorylation following replication stress and discover novel putative ATR target sites on MCM6, TOPBP1, RAD51AP1, and PSMD4. We establish that ATR inhibition rewires cellular signaling networks induced by replication stress and leads to the activation of the ATM-driven double-strand break repair signaling. PMID:26572502

  1. A novel luciferase based reporter system to monitor activation of the ErbB2/Her2/neu pathway non-invasively during radiotherapy

    PubMed Central

    Wolf, Frank; Li, Wenrong; Li, Fang; Li, Chuan-Yuan

    2010-01-01

    Purpose To develop a split-luciferase based reporter system that allows for non-invasive monitoring of activation of the Her2/neu pathway in vivo in a quantitative and sensitive manner. Methods and Materials Fusion proteins of the ErbB2/Her2/neu receptor to the N-terminal fragment of luciferase as well as of its downstream binding partner Shc to the C-terminal fragment of luciferase have been engineered based on the rationale that upon activation and binding of the Her2 receptor molecule to Shc, luciferase function will be reconstituted. Thus the resulting bioluminescence signals can serve as a surrogate measure of receptor activation. Results We show that our reporter systems functions well in vitro in breast cancer cells and in vivo in xenograft tumors. In particular, the activities of Her2/neu in xenograft tumors could be monitored serially for an extended period of time after radiotherapy. Conclusions We believe that the novel ErbB2/Her2/neu reporter presented here is a powerful tool to study the biology of the Her2-neu pathway in vitro as well as in vivo. It should also facilitate the development and rapid evaluation of new Her2/neu targeted therapeutics. PMID:20934271

  2. Novel Luciferase-Based Reporter System to Monitor Activation of ErbB2/Her2/neu Pathway Noninvasively During Radiotherapy

    SciTech Connect

    Wolf, Frank; Li Wenrong; Li Fang; Li Chuanyuan

    2011-01-01

    Purpose: To develop a split-luciferase-based reporter system that allows for noninvasive monitoring of activation of the Her2/neu pathway in vivo in a quantitative and sensitive manner. Methods and Materials: Fusion proteins of the ErbB2/Her2/neu receptor to the N-terminal fragment of luciferase and of its downstream binding partner Shc to the C-terminal fragment of luciferase have been engineered owing to the rationale that on activation and binding of the Her2 receptor molecule to Shc, luciferase function will be reconstituted. Thus, the resulting bioluminescence signals can serve as a surrogate measure of receptor activation. Results: We have shown that our reporter systems functions well in vitro in breast cancer cells and in vivo in xenograft tumors. In particular, the activities of Her2/neu in xenograft tumors could be monitored serially for an extended period after radiotherapy. Conclusions: We believe that the novel ErbB2/Her2/neu reporter we have presented is a powerful tool to study the biology of the Her2-neu pathway in vitro and in vivo. It should also facilitate the development and rapid evaluation of new Her2/neu-targeted therapeutic agents.

  3. Liposome-mediated in vivo E1A gene transfer suppressed dissemination of ovarian cancer cells that overexpress HER-2/neu.

    PubMed

    Yu, D; Matin, A; Xia, W; Sorgi, F; Huang, L; Hung, M C

    1995-10-01

    The HER-2/neu proto-oncogene is frequently amplified or overexpressed in many different types of human cancers, a phenomenon that has been shown to correlate with shorter survival time and lower survival rate in ovarian cancer patients. We previously reported that increased HER-2/neu expression led to more severe malignancy and increased metastatic potential in animal models and that the adenovirus 5 E1A gene repressed HER-2/neu gene expression at transcriptional level and was able to suppress tumor growth when stably transfected into human ovarian cancer SKOV-3 cells which overexpress HER-2/neu. To investigate whether the E1A gene may be used as a therapeutic agent for HER-2/neu-overexpressing human cancers in living hosts, we first developed tumor-bearing mice by injecting SKOV-3 cells that overexpress HER-2/neu intraperitonealy into female nu/nu mice. Five days later, we used cationic liposomes to directly deliver the E1A gene into adenocarcinomas that developed in the peritoneal cavity and on the mesentery of the mice that received the SKOV-3 cell injection. We found that liposome-mediated E1A gene transfer significantly inhibited growth and dissemination of ovarian cancer cells that overexpress HER-2/neu in the treated mice; about 70% of these mice survived at least 365 days, whereas all the control mice that did not receive the gene therapy developed severe tumor symptoms and died within 160 days. The results suggest that liposome-mediated E1A gene transfer may serve as an effective therapy for human ovarian cancers that overexpress HER-2/neu by directly targeting the HER-2/neu oncogene. PMID:7478560

  4. Imaging and biodistribution of Her2/neu expression in non-small cell lung cancer xenografts with Cu-labeled trastuzumab PET.

    PubMed

    Paudyal, Pramila; Paudyal, Bishnuhari; Hanaoka, Hirofumi; Oriuchi, Noboru; Iida, Yashuhiko; Yoshioka, Hiroki; Tominaga, Hideyuki; Watanabe, Satoshi; Watanabe, Shigeki; Ishioka, Noriko S; Endo, Keigo

    2010-04-01

    Non-small cell lung carcinomas (NSCLC) overexpress the Her2/neu gene in approximately 59% of cases. Trastuzumab, a humanized monoclonal antibody, interferes with Her2 signaling and is approved for the treatment of Her2/neu overexpressing breast cancer. However, its therapeutic use in Her2/neu overexpressing NSCLC remains obscure. The present study aimed to determine the role of (64)Cu-labeled trastuzumab positron emission tomography (PET) for non-invasive imaging of Her2/neu expression in NSCLC. Trastuzumab was conjugated with the bifunctional chelator 1, 4, 7, 10-tetraazacyclododecane-1, 4, 7, 10-tetraacetic acid (DOTA) and radiolabeled with (64)Cu. The molecular specificity of DOTA-trastuzumab was determined in NSCLC cell lines with Her2/neu overexpression (NCI-H2170) and negative expression (NCI-H520). Imaging of Her2/neu expression was performed in NCI-H2170 tumor-bearing mice with (64)Cu-DOTA-trastuzumab PET and (64)Cu-DOTA-IgG. In vitro studies revealed specific binding of DOTA-trastuzumab in the Her2/neu positive NCI-H2170 cells, while no binding was seen in the Her2/neu negative NCI-H520 cell line. Biodistribution and PET studies revealed a significantly high accumulation of (64)Cu-DOTA-trastuzumab in the Her2/neu overexpressing NCI-H2170 tumor at 24 and 48 h post-injection (21.4 +/- 1.4% and 23.2 +/- 5.1% injection dose/gram (% ID/g), respectively). PET imaging of Her2/neu negative NCI-H520 tumors showed much less uptake of (64)Cu-DOTA-trastuzumab (4.0% ID/g). The NCI-H2170 tumor uptake of (64)Cu-DOTA-trastuzumab was significantly higher than that of (64)Cu-DOTA-IgG (P < 0.0001). (64)Cu-DOTA-trastuzumab showed a very clear image of a Her2/neu positive tumor and appeared to be effective as a PET tracer for imaging of Her2/neu gene expression in NSCLC, suggesting its potential clinical use for identifying patients that might benefit from trastuzumab-based therapy. PMID:20219072

  5. Bovine herpesvirus 4-based vector delivering a hybrid rat/human HER-2 oncoantigen efficiently protects mice from autochthonous Her-2+ mammary cancer

    PubMed Central

    Jacca, Sarah; Rolih, Valeria; Quaglino, Elena; Franceschi, Valentina; Tebaldi, Giulia; Bolli, Elisabetta; Rosamilia, Alfonso; Ottonello, Simone; Cavallo, Federica; Donofrio, Gaetano

    2016-01-01

    ABSTRACT The epidermal growth factor receptor 2 (HER-2) oncogene is a major target for the immunotherapy of breast cancer. Following up to the therapeutic success achieved with Her-2-targeting monoclonal antibodies, immune-prophylactic approaches directed against Her-2 have also been investigated taking into account, and trying to overcome, Her-2 self-tolerance. Perhaps due to safety (and efficacy) concerns, the least explored anti-Her-2 active immunization strategy so far has been the one relying on viral-vectored vaccine formulations. Taking advantage of the favorable properties of bovine herpesvirus 4 (BoHV-4) in terms of safety and ease of manipulation as well as its previously documented ability to transduce and confer immunogenicity to heterologous antigens, we tested the ability of different recombinant HER-2-BoHV-4 immunogens to 8break tolerance and elicit a protective, anti-mammary tumor antibody response in HER-2 transgenic BALB-neuT mice. All the tested constructs expressed the HER-2 transgenes at high levels and elicited significant cellular immune responses in BALB/c mice upon administration via either DNA vaccination or viral infection. In BALB-neuT mice, instead, only the viral construct expressing the membrane-bound chimeric form of Her-2 protein (BoHV-4-RHuT-gD) elicited a humoral immune response that was more intense and earlier-appearing than that induced by DNA vaccination. In keeping with this observation, two administrations of BoHV-4-RHuT-gD effectively protected BALB-neuT mice from tumor formation, with 50% of vaccinated animals tumor-free after 30 weeks from immunization compared to 100% of animals exhibiting at least one palpable tumor in the case of animals vaccinated with the other BoHV-4-HER-2 constructs. PMID:27141335

  6. Molecular imaging of EGFR/HER2 cancer biomarkers by protein MRI contrast agents

    PubMed Central

    Qiao, Jingjuan; Xue, Shenghui; Pu, Fan; White, Natalie; Jiang, Jie; Liu, Zhi-Ren

    2014-01-01

    Epidermal growth factor receptor (EGFR) and HER2 are major prognosis biomarkers and drug targets overexpressed in various types of cancer cells. There is a pressing need to develop MRI contrast agents capable of enhancing the contrast between normal tissues and tumors with high relaxivity, capable of targeting tumors, and with high intratumoral distribution and minimal toxicity. In this review, we first discuss EGFR signaling and its role in tumor progression as a major drug target. We then report our progress in the development of protein contrast agents with significant improvement of both r1 and r2 relaxivities, pharmacokinetics, in vivo retention time, and in vivo dose efficiency. Finally, we report our effort in the development of EGFR-targeted protein contrast agents with the capability to cross the endothelial boundary and with good tissue distribution across the entire tumor mass. The noninvasive capability of MRI to visualize spatially and temporally the intratumoral distribution as well as quantify the levels of EGFR and HER2 would greatly improve our ability to track changes of the biomarkers during tumor progression, monitor treatment efficacy, aid in patient selection, and further develop novel targeted therapies for clinical application. PMID:24366655

  7. HER2 Status in Premalignant, Early, and Advanced Neoplastic Lesions of the Stomach

    PubMed Central

    Ieni, A.; Barresi, V.; Rigoli, L.; Caruso, R. A.; Tuccari, G.

    2015-01-01

    Objectives. HER2 expression in gastric cancer (GC) has received attention as a potential target for therapy with Trastuzumab. We reviewed the current knowledge on HER2 status in premalignant gastric lesions and in early (EGC) and advanced (AGC) GC to discuss the possible pathogenetic and prognostic roles of HER2 overexpression in GC. Results. HER2 overexpression was documented in gastric low-grade (LG) and high-grade intraepithelial neoplasia (HG-IEN), with higher frequency in gastric type dysplasia. HER2 overexpression was significantly associated with disease recurrence and poor prognosis in EGC representing an independent risk factor for lymph node metastases. HER2 overexpression was more frequent in AGC characterized by high grade, advanced stage, and high Ki-67 labeling index. The discordance in HER2 status was evidenced between primitive GC and synchronous or metachronous metastases. Conclusions. HER2 overexpression in premalignant gastric lesions suggests its potential involvement in the early steps of gastric carcinogenesis. The assessment of HER2 status in EGC may be helpful for the identification of patients who are at low risk for developing nodal metastases. Finally, the possible discordance in HER2 status between primary GC and its synchronous metastases support routine assessment of HER2 both in the primary GC and in its metastatic lesions. PMID:26494937

  8. A molecular mechanism that links Hippo signalling to the inhibition of Wnt/β-catenin signalling

    PubMed Central

    Imajo, Masamichi; Miyatake, Koichi; Iimura, Akira; Miyamoto, Atsumu; Nishida, Eisuke

    2012-01-01

    The Hippo signalling pathway has emerged as a key regulator of organ size, tissue homeostasis, and patterning. Recent studies have shown that two effectors in this pathway, YAP/TAZ, modulate Wnt/β-catenin signalling through their interaction with β-catenin or Dishevelled, depending on biological contexts. Here, we identify a novel mechanism through which Hippo signalling inhibits Wnt/β-catenin signalling. We show that YAP and TAZ, the transcriptional co-activators in the Hippo pathway, suppress Wnt signalling without suppressing the stability of β-catenin but through preventing its nuclear translocation. Our results show that YAP/TAZ binds to β-catenin, thereby suppressing Wnt-target gene expression, and that the Hippo pathway-stimulated phosphorylation of YAP, which induces cytoplasmic translocation of YAP, is required for the YAP-mediated inhibition of Wnt/β-catenin signalling. We also find that downregulation of Hippo signalling correlates with upregulation of β-catenin signalling in colorectal cancers. Remarkably, our analysis demonstrates that phosphorylated YAP suppresses nuclear translocation of β-catenin by directly binding to it in the cytoplasm. These results provide a novel mechanism, in which Hippo signalling antagonizes Wnt signalling by regulating nuclear translocation of β-catenin. PMID:22234184

  9. The Gq signalling pathway inhibits brown and beige adipose tissue

    PubMed Central

    Klepac, Katarina; Kilić, Ana; Gnad, Thorsten; Brown, Loren M.; Herrmann, Beate; Wilderman, Andrea; Balkow, Aileen; Glöde, Anja; Simon, Katharina; Lidell, Martin E.; Betz, Matthias J.; Enerbäck, Sven; Wess, Jürgen; Freichel, Marc; Blüher, Matthias; König, Gabi; Kostenis, Evi; Insel, Paul A.; Pfeifer, Alexander

    2016-01-01

    Brown adipose tissue (BAT) dissipates nutritional energy as heat via the uncoupling protein-1 (UCP1) and BAT activity correlates with leanness in human adults. Here we profile G protein-coupled receptors (GPCRs) in brown adipocytes to identify druggable regulators of BAT. Twenty-one per cent of the GPCRs link to the Gq family, and inhibition of Gq signalling enhances differentiation of human and murine brown adipocytes. In contrast, activation of Gq signalling abrogates brown adipogenesis. We further identify the endothelin/Ednra pathway as an autocrine activator of Gq signalling in brown adipocytes. Expression of a constitutively active Gq protein in mice reduces UCP1 expression in BAT, whole-body energy expenditure and the number of brown-like/beige cells in white adipose tissue (WAT). Furthermore, expression of Gq in human WAT inversely correlates with UCP1 expression. Thus, our data indicate that Gq signalling regulates brown/beige adipocytes and inhibition of Gq signalling may be a novel therapeutic approach to combat obesity. PMID:26955961

  10. Therapeutic potential of chemokine signal inhibition for metastatic breast cancer

    PubMed Central

    Kitamura, Takanori; Pollard, Jeffrey W.

    2015-01-01

    Metastatic breast cancer is incurable by current therapies including chemotherapy and immunotherapy. Accumulating evidence indicates that tumor-infiltrating macrophages promote establishment of the lethal metastatic foci and contribute to therapeutic resistance. Recent studies suggest that the accumulation of these macrophages is regulated by a chemokine network established in the tumor microenvironment. In this perspective paper, we elaborate on the chemokine signals that can attract monocytes/macrophages to the site of metastasis, and discuss whether inhibition of these chemokine signals can represent a new therapeutic strategy for metastatic breast cancer. PMID:26275794

  11. Immunotherapy with MVA-BN®-HER2 induces HER-2-specific Th1 immunity and alters the intratumoral balance of effector and regulatory T cells.

    PubMed

    Mandl, Stefanie J; Rountree, Ryan B; Dalpozzo, Katie; Do, Lisa; Lombardo, John R; Schoonmaker, Peter L; Dirmeier, Ulrike; Steigerwald, Robin; Giffon, Thierry; Laus, Reiner; Delcayre, Alain

    2012-01-01

    MVA-BN®-HER2 is a new candidate immunotherapy designed for the treatment of HER-2-positive breast cancer. Here, we demonstrate that a single treatment with MVA-BN®-HER2 exerts potent anti-tumor efficacy in a murine model of experimental pulmonary metastasis. This anti-tumor efficacy occurred despite a strong tumor-mediated immunosuppressive environment characterized by a high frequency of regulatory T cells (T(reg)) in the lungs of tumor-bearing mice. Immunogenicity studies showed that treatment with MVA-BN®-HER2 induced strongly Th1-dominated HER-2-specific antibody and T-cell responses. MVA-BN®-HER2-induced anti-tumor activity was characterized by an increased infiltration of lungs with highly activated, HER-2-specific, CD8+CD11c+ T cells accompanied by a decrease in the frequency of T(reg) cells in the lung, resulting in a significantly increased ratio of effector T cells to T(reg) cells. In contrast, administration of HER2 protein formulated in Complete Freund's Adjuvant (CFA) induced a strongly Th2-biased immune response to HER-2. However, this did not lead to significant infiltration of the tumor-bearing lungs by CD8+ T cells or the decrease in the frequency of T(reg) cells nor did it result in anti-tumor efficacy. In vivo depletion of CD8+ cells confirmed that CD8 T cells were required for the anti-tumor activity of MVA-BN®-HER2. Furthermore, depletion of CD4+ or CD25+ cells demonstrated that tumor-induced T(reg) cells promoted tumor growth and that CD4 effector cells also contribute to MVA-BN®-HER2-mediated anti-tumor efficacy. Taken together, our data demonstrate that treatment with MVA-BN®-HER2 controls tumor growth through mechanisms including the induction of Th1-biased HER-2-specific immune responses and the control of tumor-mediated immunosuppression. PMID:21822917

  12. Model-Based Design of a Decision Tree for Treating HER2+ Cancers Based on Genetic and Protein Biomarkers

    PubMed Central

    Kirouac, DC; Lahdenranta, J; Du, J; Yarar, D; Onsum, MD; Nielsen, UB; McDonagh, CF

    2015-01-01

    Human cancers are incredibly diverse with regard to molecular aberrations, dependence on oncogenic signaling pathways, and responses to pharmacological intervention. We wished to assess how cellular dependence on the canonical PI3K vs. MAPK pathways within HER2+ cancers affects responses to combinations of targeted therapies, and biomarkers predictive of their activity. Through an integrative analysis of mechanistic model simulations and in vitro cell line profiling, we designed a six-arm decision tree to stratify treatment of HER2+ cancers using combinations of targeted agents. Activating mutations in the PI3K and MAPK pathways (PIK3CA and KRAS), and expression of the HER3 ligand heregulin determined sensitivity to combinations of inhibitors against HER2 (lapatinib), HER3 (MM-111), AKT (MK-2206), and MEK (GSK-1120212; trametinib), in addition to the standard of care trastuzumab (Herceptin). The strategy used to identify effective combinations and predictive biomarkers in HER2-expressing tumors may be more broadly extendable to other human cancers. PMID:26225238

  13. Quantitative real-time RT-PCR and chromogenic in situ hybridization: precise methods to detect HER-2 status in breast carcinoma

    PubMed Central

    2009-01-01

    Background HER-2 gene testing has become an integral part of breast cancer patient diagnosis. The most commonly used assay in the clinical setting for evaluating HER-2 status is immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH). These procedures permit correlation between HER-2 expression and morphological features. However, FISH signals are labile and fade over time, making post-revision of the tumor difficult. CISH (chromogenic in situ hybridization) is an alternative procedure, with certain advantages, although still limited as a diagnostic tool in breast carcinomas. Methods To elucidate the molecular profile of HER-2 status, mRNA and protein expression in 75 invasive breast carcinomas were analyzed by real time quantitative RT-PCR (qRT-PCR) and IHC, respectively. Amplifications were evaluated in 43 of these cases by CISH and in 11 by FISH. Results The concordance rate between IHC and qRT-PCR results was 78.9%, and 94.6% for qRT-PCR and CISH. Intratumoral heterogeneity of HER-2 status was identified in three cases by CISH. The results of the three procedures were compared and showed a concordance rate of 83.8%; higher discordances were observed in 0 or 1+ immunostaining cases, which showed high-level amplification (15.4%) and HER-2 transcript overexpression (20%). Moreover, 2+ immunostaining cases presented nonamplified status (50%) by CISH and HER-2 downexpression (38.5%) by qRT-PCR. In general, concordance occurred between qRT-PCR and CISH results. A high concordance was observed between CISH/qRT-PCR and FISH. Comparisons with clinicopathological data revealed a significant association between HER-2 downexpression and the involvement of less than four lymph nodes (P = 0.0350). Conclusion Based on these findings, qRT-PCR was more precise and reproducible than IHC. Furthermore, CISH was revealed as an alternative and useful procedure for investigating amplifications involving the HER-2 gene. PMID:19309522

  14. In vivo assessment of HER2 receptor density in HER2-positive tumors by near-infrared imaging, using repeated injections of the fluorescent probe.

    PubMed

    Ardeshirpour, Yasaman; Hassan, Moinuddin; Zielinski, Rafal; Horton, Jason A; Capala, Jacek; Gandjbakhche, Amir H; Chernomordik, Victor

    2014-10-01

    HER2 overexpression and amplification of the HER2/neu gene have been found in approximately 25% of invasive breast carcinomas. They are associated with a poor prognosis and resistance to therapy in breast cancer patients. Up to now, clinical evaluation of human epidermal growth factor receptor 2 (HER2) expression is based on ex vivo methods (immunohistochemistry (IHC) or fluorescence in situ hybridization (FISH) staining of biopsied tissue). Our goal is to realize "image and treat" paradigm using targeted fluorescent probes to evaluate expression levels of cell biomarkers responsible for cancer progression and to monitor the efficacy of corresponding monoclonal antibody treatments. We used fluorescent Affibody-based probes for in vivo analysis of HER2 receptors using near-infrared optical imaging that do not interfere with binding of the therapeutic agents to these receptors. We have analyzed two types of breast carcinoma xenografts with significant differences in HER2 expression (31 and 21 according to classification) in the mouse model. Using our kinetic model to analyze the temporal variations of the fluorescence intensity in the tumor area after two subsequent injections allowed us to assess quantitatively the difference in HER2 expression levels for two tumor types (BT-474 and MD-MBA-361). This result was substantiated by ELISA ex vivo assays of HER2 expression in the same tumors. PMID:24000992

  15. A benzimidazole derivative exhibiting antitumor activity blocks EGFR and HER2 activity and upregulates DR5 in breast cancer cells

    PubMed Central

    Chu, B; Liu, F; Li, L; Ding, C; Chen, K; Sun, Q; Shen, Z; Tan, Y; Tan, C; Jiang, Y

    2015-01-01

    Aberrant expression or function of epidermal growth factor receptor (EGFR) or the closely related human epidermal growth factor receptor 2 (HER2) can promote cell proliferation and survival, thereby contributing to tumorigenesis. Specific antibodies and low-molecular-weight tyrosine kinase inhibitors of both proteins are currently in clinical trials for cancer treatment. Benzimidazole derivatives possess diverse biological activities, including antitumor activity. However, the anticancer mechanism of 5a (a 2-aryl benzimidazole compound; 2-chloro-N-(2-p-tolyl-1H-benzo[d]imidazol-5-yl)acetamide, C16H14ClN3O, MW299), a novel 2-aryl benzimidazole derivative, toward breast cancer is largely unknown. Here, we demonstrate that 5a potently inhibited both EGFR and HER2 activity by reducing EGFR and HER2 tyrosine phosphorylation and preventing downstream activation of PI3K/Akt and MEK/Erk pathways in vitro and in vivo. We also show that 5a inhibited the phosphorylation of FOXO and promoted FOXO translocation from the cytoplasm into the nucleus, resulting in the G1-phase cell cycle arrest and apoptosis. Moreover, 5a potently induced apoptosis via the c-Jun N-terminal kinase (JNK)-mediated death receptor 5 upregulation in breast cancer cells. The antitumor activity of 5a was consistent with additional results demonstrating that 5a significantly reduced tumor volume in nude mice in vivo. Analysis of the primary breast cancer cell lines with HER2 overexpression further confirmed that 5a significantly inhibited Akt Ser473 and Bad Ser136 phosphorylation and reduced cyclin D3 expression. On the basis of our findings, further development of this 2-aryl benzimidazole derivative, a new class of multitarget anticancer agents, is warranted and represents a novel strategy for improving breast cancer treatment. PMID:25766325

  16. Apatinib inhibits VEGF signaling and promotes apoptosis in intrahepatic cholangiocarcinoma.

    PubMed

    Peng, Hong; Zhang, Qiuyang; Li, Jiali; Zhang, Ning; Hua, Yunpeng; Xu, Lixia; Deng, Yubin; Lai, Jiaming; Peng, Zhenwei; Peng, Baogang; Chen, Minhu; Peng, Sui; Kuang, Ming

    2016-03-29

    Tumor cells co-express vascular endothelial growth factor (VEGF) and VEGF receptors (VEGFRs) that interact each other to support a self-sustainable cell growth. So far, this autocrine VEGF loop is not reported in human intrahepatic cholangiocarcinoma (ICC). Apatinib is a highly selective VEGFR2 inhibitor, but its effects on ICC have not been investigated. In this study, we reported that VEGF and phosphorylated VEGFR2 were expressed at a significantly high level in ICC patient tissues (P<0.05). In vitro, treating ICC cell lines RBE and SSP25 with recombinant human VEGF (rhVEGF) induced phosphorylation of VEGFR1 (pVEGFR1) and VEGFR2 (pVEGFR2); however, only the VEGFR2 played a role in the anti-apoptotic cell growth through activating a PI3K-AKT-mTOR anti-apoptotic signaling pathway which generated more VEGF to enter this autocrine loop. Apatinib inhibited the anti-apoptosis induced by VEGF signaling, and promoted cell death in vitro. In addition, Apatinib treatment delayed xenograft tumor growth in vivo. In conclusion, the autocrine VEGF/VEGFR2 signaling promotes ICC cell survival. Apatinib inhibits anti-apoptotic cell growth through suppressing the autocrine VEGF signaling, supporting a potential role for using Apatinib in the treatment of ICC. PMID:26967384

  17. Apatinib inhibits VEGF signaling and promotes apoptosis in intrahepatic cholangiocarcinoma

    PubMed Central

    Zhang, Ning; Hua, Yunpeng; Xu, Lixia; Deng, Yubin; Lai, Jiaming; Peng, Zhenwei; Peng, Baogang; Chen, Minhu; Peng, Sui; Kuang, Ming

    2016-01-01

    Tumor cells co-express vascular endothelial growth factor (VEGF) and VEGF receptors (VEGFRs) that interact each other to support a self-sustainable cell growth. So far, this autocrine VEGF loop is not reported in human intrahepatic cholangiocarcinoma (ICC). Apatinib is a highly selective VEGFR2 inhibitor, but its effects on ICC have not been investigated. In this study, we reported that VEGF and phosphorylated VEGFR2 were expressed at a significantly high level in ICC patient tissues (P<0.05). In vitro, treating ICC cell lines RBE and SSP25 with recombinant human VEGF (rhVEGF) induced phosphorylation of VEGFR1 (pVEGFR1) and VEGFR2 (pVEGFR2); however, only the VEGFR2 played a role in the anti-apoptotic cell growth through activating a PI3K-AKT-mTOR anti-apoptotic signaling pathway which generated more VEGF to enter this autocrine loop. Apatinib inhibited the anti-apoptosis induced by VEGF signaling, and promoted cell death in vitro. In addition, Apatinib treatment delayed xenograft tumor growth in vivo. In conclusion, the autocrine VEGF/VEGFR2 signaling promotes ICC cell survival. Apatinib inhibits anti-apoptotic cell growth through suppressing the autocrine VEGF signaling, supporting a potential role for using Apatinib in the treatment of ICC. PMID:26967384

  18. Current and emerging therapies of HER2-positive metastatic breast cancer.

    PubMed

    Hernández-Blanquisett, Abraham; Touya, Diego; Strasser-Weippl, Kathrin; Ruiz, Rossana; St Louis, Jessica; Goss, Paul

    2016-10-01

    The HER2 receptor as measured by immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) is overexpressed in 15-20% of all breast cancers and traditionally represents adverse biology and a guarded prognosis, particularly in HER2 positive metastatic breast cancer (MBC). Trastuzumab and newer anti-HER2 targeting agents have significantly improved the clinical outcomes of patients with HER2 positive MBC. The development of new techniques has led to discovery of promising biomarkers that can lead to more precise selection of patients for anti-HER2 therapies. This paper summarizes these new biomarkers, useful in selecting patients for treatment with new and emerging therapies for HER2 positive MBC. Emerging next generation sequencing techniques have truly changed the landscape of HER2 positive MBC. Deployment of multiple anti-HER2 therapies in combination is a strategy which has yielded additive or even synergistic effects and has led to markedly improved patient outcomes in HER2+ MBC. In the future, in order to further improve the treatment of these patients and to reduce toxicities, we need to improve our understanding of HER2-dependent pathways and their function, and to develop further treatment combinations while optimizing selection of patients by identifying new biomarkers. The results of prospective studies using CTCs, cDNA and other promising new biomarkers are awaited with great interest. PMID:27526299

  19. Current Approaches and Emerging Directions in HER2-resistant Breast Cancer

    PubMed Central

    Brufsky, Adam M

    2014-01-01

    Human epidermal growth factor receptor-2 (HER2) is overexpressed in up to 30% of breast cancers; HER2 overexpression is indicative of poor prognosis. Trastuzumab, an anti-HER2 monoclonal antibody, has led to improved outcomes in patients with HER2-positive breast cancer, including improved overall survival in adjuvant and first-line settings. However, a large proportion of patients with breast cancer have intrinsic resistance to HER2-targeted therapies, and nearly all become resistant to therapy after initial response. Elucidation of underlying mechanisms contributing to HER2 resistance has led to development of novel therapeutic strategies, including those targeting HER2 and downstream pathways, heat shock protein 90, telomerase, and vascular endothelial growth factor inhibitors. Numerous clinical trials are ongoing or completed, including phase 3 data for the mammalian target of rapamycin inhibitor everolimus in patients with HER2-resistant breast cancer. This review considers the molecular mechanisms associated with HER2 resistance and evaluates the evidence for use of evolving strategies in patients with HER2-resistant breast cancer. PMID:25125981

  20. Her2/neu extracellular domain shedding in uterine serous carcinoma: implications for immunotherapy with trastuzumab

    PubMed Central

    Todeschini, P; Cocco, E; Bellone, S; Varughese, J; Lin, K; Carrara, L; Guzzo, F; Buza, N; Hui, P; Silasi, D-A; Ratner, E; Azodi, M; Schwartz, P E; Rutherford, T J; Pecorelli, S; Santin, A D

    2011-01-01

    Background: We evaluated shedding of epidermal growth factor type II receptor (Her2/neu) extracellular domain (ECD) in primary uterine serous carcinoma (USC) cell lines and in the serum of USC patients and its biological effects in experiments of trastuzumab-induced cytotoxicity in vitro. Methods: Her2/neu expression was evaluated by immunohistochemistry (IHC), real-time PCR and flow cytometry, while c-erbB2 gene amplification was assessed using fluorescent in situ hybridisation (FISH). Her2/neu ECD levels in the supernatants of USC cell lines and in the serum of 38 USC patients and 19 controls were tested using ELISA. The biologic effect of Her2/neu ECD on trastuzumab-induced antibody-dependent cell-mediated cytotoxicity (ADCC) was evaluated in 5-h chromium-release assays. Results: Five out of ten USC cell lines overexpressed Her2/neu by IHC and showed amplification of the c-erbB2 gene. High levels of Her2/neu ECD were found in supernatants of all FISH-positive tumours. In contrast, FISH-negative USC was negative for Her2/neu ECD shedding. Serum Her2/neu ECD levels in patients harbouring 3+Her2/neu tumours were higher than those found in healthy women (P=0.02) or USC patients with 2+ or 1+/negative Her2/neu expression (P=0.02). In cytotoxicity experiments, trastuzumab-mediated ADCC was significantly decreased by the addition of Her2/neu ECD-containing supernatants (P=0.01). Conclusion: FISH-positive c-erbB2 USC cell lines shed high levels of Her2/neu ECD. High levels of Her2/neu ECD in USC patients may reduce trastuzumab-mediated ADCC in vitro and potentially neutralise its therapeutic effect in vivo. PMID:21915118

  1. Engineering and characterization of a bispecific HER2 x EGFR-binding affibody molecule.

    PubMed

    Friedman, Mikaela; Lindström, Sara; Ekerljung, Lina; Andersson-Svahn, Helene; Carlsson, Jörgen; Brismar, Hjalmar; Gedda, Lars; Frejd, Fredrik Y; Ståhl, Stefan

    2009-10-01

    HER2 (human epidermal-growth-factor receptor-2; ErbB2) and EGFR (epidermal-growth-factor receptor) are overexpressed in various forms of cancer, and the co-expression of both HER2 and EGFR has been reported in a number of studies. The simultaneous targeting of HER2 and EGFR has been discussed as a strategy with which to potentially increase efficiency and selectivity in molecular imaging and therapy of certain cancers. In an effort to generate a molecule capable of bispecifically targeting HER2 and EGFR, a gene fragment encoding a bivalent HER2-binding affibody molecule was genetically fused in-frame with a bivalent EGFR-binding affibody molecule via a (G4S)3 [(Gly4-Ser)3]-encoding gene fragment. The encoded 30 kDa affibody construct (ZHER2)2-(G4S)3-(ZEGFR)2, with potential for bs (bispecific) binding to HER2 and EGFR, was expressed in Escherichia coli and characterized in terms of its binding capabilities. The retained ability to bind HER2 and EGFR separately was demonstrated using both biosensor technology and flow-cytometric analysis, the latter using HER2- and EGFR-overexpressing cells. Furthermore, simultaneous binding to HER2 and EGFR was demonstrated in: (i) a sandwich format employing real-time biospecific interaction analysis where the bs affibody molecule bound immobilized EGFR and soluble HER2; (ii) immunofluorescence microscopy, where the bs affibody molecule bound EGFR-overexpressing cells and soluble HER2; and (iii) a cell-cell interaction analysis where the bs affibody molecule bound HER2-overexpressing SKBR-3 cells and EGFR-overexpressing A-431 cells. This is, to our knowledge, the first reported bs affinity protein with potential ability for the simultaneous targeting of HER2 and EGFR. The potential future use of this and similar constructs, capable of bs targeting of receptors to increase the efficacy and selectivity in imaging and therapy, is discussed. PMID:19492986

  2. Her-2 overexpression increases the metastatic outgrowth of breast cancer cells in the brain.

    PubMed

    Palmieri, Diane; Bronder, Julie L; Herring, Jeanne M; Yoneda, Toshiyuki; Weil, Robert J; Stark, Andreas M; Kurek, Raffael; Vega-Valle, Eleazar; Feigenbaum, Lionel; Halverson, Douglas; Vortmeyer, Alexander O; Steinberg, Seth M; Aldape, Kenneth; Steeg, Patricia S

    2007-05-01

    Retrospective studies of breast cancer patients suggest that primary tumor Her-2 overexpression or trastuzumab therapy is associated with a devastating complication: the development of central nervous system (brain) metastases. Herein, we present Her-2 expression trends from resected human brain metastases and data from an experimental brain metastasis assay, both indicative of a functional contribution of Her-2 to brain metastatic colonization. Of 124 archival resected brain metastases from breast cancer patients, 36.2% overexpressed Her-2, indicating an enrichment in the frequency of tumor Her-2 overexpression at this metastatic site. Using quantitative real-time PCR of laser capture microdissected epithelial cells, Her-2 and epidermal growth factor receptor (EGFR) mRNA levels in a cohort of 12 frozen brain metastases were increased up to 5- and 9-fold, respectively, over those of Her-2-amplified primary tumors. Co-overexpression of Her-2 and EGFR was also observed in a subset of brain metastases. We then tested the hypothesis that overexpression of Her-2 increases the colonization of breast cancer cells in the brain in vivo. A subclone of MDA-MB-231 human breast carcinoma cells that selectively metastasizes to brain (231-BR) overexpressed EGFR; 231-BR cells were transfected with low (4- to 8-fold) or high (22- to 28-fold) levels of Her-2. In vivo, in a model of brain metastasis, low or high Her-2-overexpressing 231-BR clones produced comparable numbers of micrometastases in the brain as control transfectants; however, the Her-2 transfectants yielded 3-fold greater large metastases (>50 microm(2); P < 0.001). Our data indicate that Her-2 overexpression increases the outgrowth of metastatic tumor cells in the brain in this model system. PMID:17483330

  3. Dual-Labeled Near-Infrared/99mTc Imaging Probes Using PAMAM-Coated Silica Nanoparticles for the Imaging of HER2-Expressing Cancer Cells

    PubMed Central

    Yamaguchi, Haruka; Tsuchimochi, Makoto; Hayama, Kazuhide; Kawase, Tomoyuki; Tsubokawa, Norio

    2016-01-01

    We sought to develop dual-modality imaging probes using functionalized silica nanoparticles to target human epidermal growth factor receptor 2 (HER2)-overexpressing breast cancer cells and achieve efficient target imaging of HER2-expressing tumors. Polyamidoamine-based functionalized silica nanoparticles (PCSNs) for multimodal imaging were synthesized with near-infrared (NIR) fluorescence (indocyanine green (ICG)) and technetium-99m (99mTc) radioactivity. Anti-HER2 antibodies were bound to the labeled PCSNs. These dual-imaging probes were tested to image HER2-overexpressing breast carcinoma cells. In vivo imaging was also examined in breast tumor xenograft models in mice. SK-BR3 (HER2 positive) cells were imaged with stronger NIR fluorescent signals than that in MDA-MB231 (HER2 negative) cells. The increased radioactivity of the SK-BR3 cells was also confirmed by phosphor imaging. NIR images showed strong fluorescent signals in the SK-BR3 tumor model compared to muscle tissues and the MDA-MB231 tumor model. Automatic well counting results showed increased radioactivity in the SK-BR3 xenograft tumors. We developed functionalized silica nanoparticles loaded with 99mTc and ICG for the targeting and imaging of HER2-expressing cells. The dual-imaging probes efficiently imaged HER2-overexpressing cells. Although further studies are needed to produce efficient isotope labeling, the results suggest that the multifunctional silica nanoparticles are a promising vehicle for imaging specific components of the cell membrane in a dual-modality manner. PMID:27399687

  4. Dual-Labeled Near-Infrared/(99m)Tc Imaging Probes Using PAMAM-Coated Silica Nanoparticles for the Imaging of HER2-Expressing Cancer Cells.

    PubMed

    Yamaguchi, Haruka; Tsuchimochi, Makoto; Hayama, Kazuhide; Kawase, Tomoyuki; Tsubokawa, Norio

    2016-01-01

    We sought to develop dual-modality imaging probes using functionalized silica nanoparticles to target human epidermal growth factor receptor 2 (HER2)-overexpressing breast cancer cells and achieve efficient target imaging of HER2-expressing tumors. Polyamidoamine-based functionalized silica nanoparticles (PCSNs) for multimodal imaging were synthesized with near-infrared (NIR) fluorescence (indocyanine green (ICG)) and technetium-99m ((99m)Tc) radioactivity. Anti-HER2 antibodies were bound to the labeled PCSNs. These dual-imaging probes were tested to image HER2-overexpressing breast carcinoma cells. In vivo imaging was also examined in breast tumor xenograft models in mice. SK-BR3 (HER2 positive) cells were imaged with stronger NIR fluorescent signals than that in MDA-MB231 (HER2 negative) cells. The increased radioactivity of the SK-BR3 cells was also confirmed by phosphor imaging. NIR images showed strong fluorescent signals in the SK-BR3 tumor model compared to muscle tissues and the MDA-MB231 tumor model. Automatic well counting results showed increased radioactivity in the SK-BR3 xenograft tumors. We developed functionalized silica nanoparticles loaded with (99m)Tc and ICG for the targeting and imaging of HER2-expressing cells. The dual-imaging probes efficiently imaged HER2-overexpressing cells. Although further studies are needed to produce efficient isotope labeling, the results suggest that the multifunctional silica nanoparticles are a promising vehicle for imaging specific components of the cell membrane in a dual-modality manner. PMID:27399687

  5. Imaging of Her2-Targeted Magnetic Nanoparticles for Breast Cancer Detection: Comparison of SQUID-detected Magnetic Relaxometry and MRI

    PubMed Central

    Adolphi, Natalie L.; Butler, Kimberly S.; Lovato, Debbie M.; Tessier, T. E.; Trujillo, Jason E.; Hathaway, Helen J.; Fegan, Danielle L.; Monson, Todd C.; Stevens, Tyler E.; Huber, Dale L.; Ramu, Jaivijay; Milne, Michelle L.; Altobelli, Stephen A.; Bryant, Howard C.; Larson, Richard S.; Flynn, Edward R.

    2013-01-01

    Both magnetic relaxometry and magnetic resonance imaging (MRI) can be used to detect and locate targeted magnetic nanoparticles, non-invasively and without ionizing radiation. Magnetic relaxometry offers advantages in terms of its specificity (only nanoparticles are detected) and the linear dependence of the relaxometry signal on the number of nanoparticles present. In this study, detection of single-core iron oxide nanoparticles by Superconducting Quantum Interference Device (SQUID)-detected magnetic relaxometry and standard 4.7 T MRI are compared. The nanoparticles were conjugated to a Her2 monoclonal antibody and targeted to Her2-expressing MCF7/Her2-18 breast cancer cells); binding of the nanoparticles to the cells was assessed by magnetic relaxometry and iron assay. The same nanoparticle-labeled cells, serially diluted, were used to assess the detection limits and MR relaxivities. The detection limit of magnetic relaxometry was 125,000 nanoparticle-labeled cells at 3 cm from the SQUID sensors. T2-weighted MRI yielded a detection limit of 15,600 cells in a 150 μl volume, with r1 = 1.1 mM−1s−1 and r2 = 166 mM−1s−1. Her2-targeted nanoparticles were directly injected into xenograft MCF7/Her2-18 tumors in nude mice, and magnetic relaxometry imaging and 4.7 T MRI were performed, enabling direct comparison of the two techniques. Co-registration of relaxometry images and MRI of mice resulted in good agreement. A method for obtaining accurate quantification of microgram quantities of iron in the tumors and liver by relaxometry was also demonstrated. These results demonstrate the potential of SQUID-detected magnetic relaxometry imaging for the specific detection of breast cancer and the monitoring of magnetic nanoparticle-based therapies. PMID:22539401

  6. Model-based Analysis of HER Activation in Cells Co-Expressing EGFR, HER2 and HER3.

    SciTech Connect

    Shankaran, Harish; Zhang, Yi; Tan, Yunbing; Resat, Haluk

    2013-08-22

    The HER/ErbB family of receptor tyrosine kinases drive critical responses in normal physiology and cancer, and the expression levels of the various HER receptors are critical determinants of clinical outcomes. HER activation is driven by the formation of various dimer complexes between members of this receptor family. The HER dimer types can have differential effects on downstream signaling and phenotypic outcomes. We constructed an integrated mathematical model of HER activation and trafficking to quantitatively link receptor expression levels to dimerization and activation. We parameterized the model with a comprehensive set of HER phosphorylation and abundance data collected in a panel of human mammary epithelial cells expressing varying levels of EGFR, HER2 and HER3. Although parameter estimation yielded multiple solutions, predictions for dimer phosphorylation were in agreement with each other. We validated the model using experiments where pertuzumab was used to block HER2 dimerization. We used the model to predict HER dimerization and activation patterns in a panel of epithelial cells lines with known HER expression levels. Simulations over the range of expression levels seen in various cell lines indicate that: i) EGFR phosphorylation is driven by HER1/1 and HER1/2 dimers, and not HER1/3 dimers, ii) HER1/2 and HER2/3 dimers both contribute significantly to HER2 activation with the EGFR expression level determining the relative importance of these species, and iii) the HER2/3 dimer is largely responsible for HER3 activation. The model can be used to predict phosphorylated dimer levels for any given HER expression profile. This information in turn can be used to quantify the potencies of the various HER dimers, and can potentially inform personalized therapeutic approaches.

  7. Functional SNP in stem of mir-146a affects Her2 status and breast cancer survival.

    PubMed

    Meshkat, Mahboobeh; Tanha, Hamzeh Mesrian; Naeini, Marjan Mojtabavi; Ghaedi, Kamran; Sanati, Mohammad H; Meshkat, Marzieh; Bagheri, Fatemeh

    2016-07-01

    In-silico investigation suggested a common variant within stem of miR-146a-5p precursor (rs2910164, n.60C>G) associated with breast cancer (BC) phenotypes. Our aim was computationally predicting possible targets of miR-146a-5p and probable rs2910164 mechanism of action in expression of phenotypes in BC. Additionally, a case-control study was designated to examine experimentally the correlation of mir-146a rs2910164 variant and BC phenotypes. In this study, 152 BC subjects and healthy controls were genotyped using RFLP-PCR. Allelic and genotypic association and Armitage's trend tests were run to investigate the correlation between the alleles and genotypes and expressed phenotypes of BC. Bioinformatics analyses introduce regulatory function of miR-146a-5p in numerous signaling pathways and impact of allele substitution upon mir-146a stem-loop stability. Logistic regression data represented the C allele of rs2910164 (OR = 4.00, p= 0.0037) as the risk allele and associated with Her2-positive phenotype. In a similar vein, data revealed the correlation of the C allele and cancer death less than two years in BC patients (OR = 2.65, p= 0.0217). Ultimately, unconditional logistical regression models suggested log-additive model for inheritance manner of rs2910164 in either Her2 status or BC survival (OR = 5.64, p= 0.0025 and OR = 3.13, p= 0.019, respectively). Using bioinformatics connected association of Her2 status to altered function of miR-146a-5p in regulation of focal adhesion and Ras pathway. Furthermore, computations inferred the association between death phenotype and studied SNP upon specific target genes of miR-146a-5p involved in focal adhesion, EGF receptor, Ras, ErbB, interleukin, Toll-like receptor, NGF, angiogenesis, and p53 feedback loops 2 signaling pathways. These verdicts may enhance our perceptions of how mir-146a rs2910164 affect expressed phenotypes in BC, and might have potential implications to develop BC treatment in future. PMID:27434289

  8. Prognostic Significance of HER-2 Status in Women With Inflammatory Breast Cancer

    PubMed Central

    Dawood, Shaheenah; Broglio, Kristine; Gong, Yun; Yang, Wei-Tse; Cristofanilli, Massimo; Kau, Shu-Wan; Meric-Bernstam, Funda; Buchholz, Thomas A.; Hortobagyi, Gabriel N; Gonzalez-Angulo, Ana M.

    2015-01-01

    BACKGROUND Inflammatory breast cancer (IBC) is a rare, aggressive form of breast cancer with poorly understood prognostic variables. The purpose of this study was to define the prognostic impact of HER-2 status on survival outcomes of patients with IBC. METHODS In all, 179 patients with IBC, diagnosed between 1989 and 2005, with known HER-2 status, and treated with an anthracycline-based chemotherapy regimen without trastuzumab, were included in the analysis. Patients with HER-2-positive disease who received trastuzumab at the time of disease recurrence were included. Survival outcomes were estimated by the Kaplan-Meier product limit method and compared across groups using the log-rank statistic. A Cox proportional hazards model was fitted to determine the association of survival outcomes with HER-2 status after adjusting for patient and tumor characteristics. RESULTS A total of 111 patients (62%) had HER-2-negative disease and 68 (38%) had HER-2-positive disease. The median follow-up among all patients was 35 months. At the time of the analysis, 62 patients (55.9%) with HER-2-negative disease and 42 patients (61.8%) with HER-2-positive disease had a recurrence. Thirty-one patients (73.8%) with HER-2-positive disease who had a disease recurrence went on to receive trastuzumab. On univariate analysis, no statistically significant difference was observed for either recurrence-free survival (P = .75) or overall survival (P = .24) between patients who had HER-2-positive disease and those who had HER-2-negative disease. In a multivariate model, HER-2 status did not appear to significantly affect recurrence-free survival (hazards ratio [HR] of 0.75; 95% confidence interval [95% CI], 0.46–1.22 [P = .241]). In the multivariate model, patients with HER-2-positive disease had a decreased hazard of death (HR of 0.56; 95% CI, 0.34–0.93 [P = .024]) compared with patients with HER-2-negative disease. CONCLUSIONS HER-2 status, in the absence of trastuzumab, did not appear to

  9. Update on HER-2 as a target for cancer therapy: HER2/neu peptides as tumour vaccines for T cell recognition

    PubMed Central

    Correa, Isabel; Plunkett, Tim

    2001-01-01

    During the past decade there has been renewed interest in the use of vaccine immunotherapy for the treatment of cancer. This review focuses on HER2/neu, a tumour-associated antigen that is overexpressed in 10–40% of breast cancers and other carcinomata. Several immunogenic HER2/neu peptides recognized by T lymphocytes have been identified to be included in cancer vaccines. Some of these peptides have been assessed in clinical trials of patients with breast and ovarian cancer. Although it has been possible to detect immunological responses against the peptides in the immunized patients, no clinical responses have so far been described. Immunological tolerance to self-antigens like HER2/neu may limit the functional immune responses against them. It will be of interest to determine whether immune responses against HER2/neu epitopes can be of relevance to cancer treatment. PMID:11737893

  10. Estrogen receptor beta signals to inhibition of cardiac fibrosis.

    PubMed

    Pedram, Ali; Razandi, Mahnaz; Narayanan, Ramesh; Levin, Ellis R

    2016-10-15

    Cardiac fibrosis evolves from the cardiac hypertrophic state. In this respect, estrogen and estrogen receptor beta (ERβ) inhibit the effects of cardiac hypertrophic peptides that also stimulate fibrosis. Here we determine details of the anti-fibrotic functions of ERβ. In acutely isolated rat cardiac fibroblasts. E2 or a specific ERβ agonist (βLGND2) blocked angiotensin II (AngII) signaling to fibrosis. This resulted from ERβ activating protein kinase A and AMP kinase, inhibiting both AngII de-phosphorylation of RhoA and the resulting stimulation of Rho kinase. Inhibition of Rho kinase from ERβ signaling resulted in marked decrease of TGFβ expression, connective tissue growth factor production and function, matrix metalloproteinases 2 and 9 expression and activity, and the conversion of fibroblasts to myofibroblasts. Production of collagens I and III were also significantly decreased. Several important aspects were corroborated in-vivo from βLGND2-treated mice that underwent AngII-induced cardiac hypertrophy. Thus, ERβ in cardiac fibroblasts prevents key aspects of cardiac fibrosis development. PMID:27321970

  11. miR-217 and CAGE form feedback loop and regulates the response to anti-cancer drugs through EGFR and HER2

    PubMed Central

    Han, Minho; Lee, Hansoo; Lee, Yun Sil; Choe, Jongseon; Kim, Young Myeong; Jeoung, Dooil

    2016-01-01

    MicroRNA array analysis revealed that miR-217 expression was decreased in anti-cancer drug-resistant Malme3MR cancer cells. CAGE, a cancer/testis antigen, was predicted as a target of miR-217. Luciferase activity and ChIP assays revealed a negative feedback relationship between CAGE and miR-217. miR-217 and CAGE oppositely regulated the response to anti-cancer drugs such as taxol, gefitinib and trastuzumab, an inhibitor of HER2. miR-217 negatively regulated the tumorigenic, metastatic, angiogenic, migration and invasion potential of cancer cells. The xenograft of Malme3MR cells showed an increased expression of pEGFRY845. CAGE and miR-217 inhibitor regulated the expression of pEGFRY845. CAGE showed interactions with EGFR and HER2 and regulated the in vivo sensitivity to trastuzumab. The down-regulation of EGFR or HER2 enhanced the sensitivity to anti-cancer drugs. CAGE showed direct regulation of HER2 and was necessary for the interaction between EGFR and HER2 in Malme3MR cells. miR-217 inhibitor induced interactions of CAGE with EGFR and HER2 in Malme3M cells. The inhibition of EGFR by CAGE-binding GTGKT peptide enhanced the sensitivity to gefitinib and trastuzumab and prevented interactions of EGFR with CAGE and HER2. Our results show that miR-217-CAGE feedback loop serves as a target for overcoming resistance to various anti-cancer drugs, including EGFR and HER2 inhibitors. PMID:26863629

  12. T-DM1, a novel antibody-drug conjugate, is highly effective against primary HER2 overexpressing uterine serous carcinoma in vitro and in vivo.

    PubMed

    English, Diana P; Bellone, Stefania; Schwab, Carlton L; Bortolomai, Ileana; Bonazzoli, Elena; Cocco, Emiliano; Buza, Natalia; Hui, Pei; Lopez, Salvatore; Ratner, Elena; Silasi, Dan-Arin; Azodi, Masoud; Schwartz, Peter E; Rutherford, Thomas J; Santin, Alessandro D

    2014-10-01

    Amplification of c-erbB2 has been reported in over 30% of uterine serous carcinoma (USC) and found to confer poor survival because of high proliferation and increased resistance to therapy. In this study, we evaluated for the first time Trastuzumab emtansine (T-DM1), a novel antibody-drug conjugate, against multiple epidermal growth factor receptor-2 (HER2)-positive USC cells in vitro followed by developing a supportive in vivo model. Fifteen primary USC cell lines were assessed by immunohistochemistry (IHC) and flow cytometry for HER2 protein expression. C-erbB2 gene amplification was evaluated using fluorescent in situ hybridization. Sensitivity to T-DM1 and trastuzumab (T)-induced antibody-dependent cell-mediated cytotoxicity was evaluated in 5-h chromium release assays. T-DM1 and T cytostatic and apoptotic activities were evaluated using flow-cytometry-based proliferation assays. In vivo activity of T-DM1 versus T in USC xenografts in SCID mice was also evaluated. High levels of HER2 protein overexpression and HER2 gene amplification were detected in 33% of USC cell lines. T-DM1 was considerably more effective than trastuzumab in inhibiting cell proliferation and in causing apoptosis (P = 0.004) of USC showing HER2 overexpression. Importantly, T-DM1 was highly active at reducing tumor formation in vivo in USC xenografts overexpressing HER2 (P = 0.04) and mice treated with TDM-1 had significantly longer survival when compared to T-treated mice and control mice (P ≤ 0.0001). T-DM1 shows promising antitumor effect in HER2-positive USC cell lines and USC xenografts and its activity is significantly higher when compared to T. T-DM1 may represent a novel treatment option for HER2-positive USC patients with disease refractory to trastuzumab and traditional chemotherapy. PMID:24890382

  13. T-DM1, a novel antibody–drug conjugate, is highly effective against primary HER2 overexpressing uterine serous carcinoma in vitro and in vivo

    PubMed Central

    English, Diana P; Bellone, Stefania; Schwab, Carlton L; Bortolomai, Ileana; Bonazzoli, Elena; Cocco, Emiliano; Buza, Natalia; Hui, Pei; Lopez, Salvatore; Ratner, Elena; Silasi, Dan-Arin; Azodi, Masoud; Schwartz, Peter E; Rutherford, Thomas J; Santin, Alessandro D

    2014-01-01

    Amplification of c-erbB2 has been reported in over 30% of uterine serous carcinoma (USC) and found to confer poor survival because of high proliferation and increased resistance to therapy. In this study, we evaluated for the first time Trastuzumab emtansine (T-DM1), a novel antibody–drug conjugate, against multiple epidermal growth factor receptor-2 (HER2)-positive USC cells in vitro followed by developing a supportive in vivo model. Fifteen primary USC cell lines were assessed by immunohistochemistry (IHC) and flow cytometry for HER2 protein expression. C-erbB2 gene amplification was evaluated using fluorescent in situ hybridization. Sensitivity to T-DM1 and trastuzumab (T)-induced antibody-dependent cell-mediated cytotoxicity was evaluated in 5-h chromium release assays. T-DM1 and T cytostatic and apoptotic activities were evaluated using flow-cytometry-based proliferation assays. In vivo activity of T-DM1 versus T in USC xenografts in SCID mice was also evaluated. High levels of HER2 protein overexpression and HER2 gene amplification were detected in 33% of USC cell lines. T-DM1 was considerably more effective than trastuzumab in inhibiting cell proliferation and in causing apoptosis (P = 0.004) of USC showing HER2 overexpression. Importantly, T-DM1 was highly active at reducing tumor formation in vivo in USC xenografts overexpressing HER2 (P = 0.04) and mice treated with TDM-1 had significantly longer survival when compared to T-treated mice and control mice (P ≤ 0.0001). T-DM1 shows promising antitumor effect in HER2-positive USC cell lines and USC xenografts and its activity is significantly higher when compared to T. T-DM1 may represent a novel treatment option for HER2-positive USC patients with disease refractory to trastuzumab and traditional chemotherapy. PMID:24890382

  14. T-DM1, a novel antibody-drug conjugate, is highly effective against uterine and ovarian carcinosarcomas overexpressing HER2

    PubMed Central

    Nicoletti, Roberta; Lopez, Salvatore; Bellone, Stefania; Cocco, Emiliano; Schwab, Carlton L.; Black, Jonathan D.; Centritto, Floriana; Zhu, Liancheng; Bonazzoli, Elena; Buza, Natalia; Hui, Pei; Mezzanzanica, Delia; Canevari, Silvana; Schwartz, Peter E.; Rutherford, Thomas J.; Santin, Alessandro D.

    2014-01-01

    Introduction Ovarian and uterine carcinosarcoma (CS) are characterized by their aggressive clinical behavior and poor prognosis. We evaluated the efficacy of trastuzumab-emtansine (T-DM1), against primary HER2 positive and HER2 negative CS cell lines in vitro and in vivo. Methods Eight primary CS cell lines were evaluated for HER2 amplification and protein expression by FISH, immunohistochemistry, flow cytometry and qRT-PCR. Sensitivity to T-DM1-induced antibody-dependent-cell-mediated-cytotoxicity (ADCC) was evaluated in 4-hr-chromium-release-assays. T-DM1 cytostatic and apoptotic activities were evaluated using flow cytometry based proliferation assays. In vivo activity of T-DM1 was also evaluated. Results HER2 protein overexpression and gene amplification were detected in 25% (2/8) of the primary CS cell lines. T-DM1 and T were similarly effective in inducing strong ADCC against CS overexpressing HER2 at 3+ levels. In contrast, T-DM1 was dramatically more effective than T in inhibiting cell proliferation (P<0.0001) and in inducing G2/M phase cell cycle arrest in the HER2 expressing cell lines (shift of G2/M: mean ± SEM from 14.87 ± 1.23% to 66.57 ± 4.56%, P<0.0001). Importantly, T-DM1 was highly active at reducing tumor formation in vivo in CS xenografts overexpressing HER2 (P=0.0001 and P<0.0001 compared to T and vehicle respectively) with a significantly longer survival when compared to T and vehicle mice (P=0.008 and P=0.0001 respectively). Conclusion T-DM1 may represent a novel treatment option for the subset of HER2 positive CS patients with disease refractory to chemotherapy. PMID:25398397

  15. T-DM1, a novel antibody-drug conjugate, is highly effective against uterine and ovarian carcinosarcomas overexpressing HER2.

    PubMed

    Nicoletti, Roberta; Lopez, Salvatore; Bellone, Stefania; Cocco, Emiliano; Schwab, Carlton L; Black, Jonathan D; Centritto, Floriana; Zhu, Liancheng; Bonazzoli, Elena; Buza, Natalia; Hui, Pei; Mezzanzanica, Delia; Canevari, Silvana; Schwartz, Peter E; Rutherford, Thomas J; Santin, Alessandro D

    2015-01-01

    Ovarian and uterine carcinosarcoma (CS) are characterized by their aggressive clinical behavior and poor prognosis. We evaluated the efficacy of trastuzumab-emtansine (T-DM1), against primary HER2 positive and HER2 negative CS cell lines in vitro and in vivo. Eight primary CS cell lines were evaluated for HER2 amplification and protein expression by fluorescence in situ hybridization, immunohistochemistry, flow cytometry and qRT-PCR. Sensitivity to T-DM1-induced antibody-dependent-cell-mediated-cytotoxicity (ADCC) was evaluated in 4-h-chromium-release-assays. T-DM1 cytostatic and apoptotic activities were evaluated using flow cytometry based proliferation assays. In vivo activity of T-DM1 was also evaluated. HER2 protein overexpression and gene amplification were detected in 25 % (2/8) of the primary CS cell lines. T-DM1 and T were similarly effective in inducing strong ADCC against CS overexpressing HER2 at 3+ levels. In contrast, T-DM1 was dramatically more effective than T in inhibiting cell proliferation (P < 0.0001) and in inducing G2/M phase cell cycle arrest in the HER2 expressing cell lines (shift of G2/M: mean ± SEM from 14.87 ± 1.23 to 66.57 ± 4.56 %, P < 0.0001). Importantly, T-DM1 was highly active at reducing tumor formation in vivo in CS xenografts overexpressing HER2 (P = 0.0001 and P < 0.0001 compared to T and vehicle respectively) with a significantly longer survival when compared to T and vehicle mice (P = 0.008 and P = 0.0001 respectively). T-DM1 may represent a novel treatment option for the subset of HER2 positive CS patients with disease refractory to chemotherapy. PMID:25398397

  16. HER2 Status Determination: Analyzing the Problems to Find the Solutions

    PubMed Central

    Terrenato, Irene; Pennacchia, Ilaria; Buglioni, Simonetta; Mottolese, Marcella; Arena, Vincenzo

    2015-01-01

    Abstract Misdiagnosis in the evaluation of HER2 status in breast cancer may have consequent negative impact on clinical decision-making. Therefore, it has become ever more important to share procedures and interpretation criteria for HER2 testing among laboratories. Herein, we report an interlaboratory survey among 9 hospitals located in the central-south regions of Italy. The centers sent a series of 36 slides, 4 for each HER2 score, to the revising centers. We found a good concordance in HER2 scoring for 0 and 3+ score, but a very low concordance for 1+ and 2+ scores. To focus on factors that may lead to discordant results, we report 4 cases which summarized the most common source of discrepancy in HER2 testing. This methodological approach will help the individual laboratory to minimize technical variables and to reduce the percentage of erroneous interpretations of HER2 status. PMID:25881836

  17. Small molecule activation of NOTCH signaling inhibits acute myeloid leukemia

    PubMed Central

    Ye, Qi; Jiang, Jue; Zhan, Guanqun; Yan, Wanyao; Huang, Liang; Hu, Yufeng; Su, Hexiu; Tong, Qingyi; Yue, Ming; Li, Hua; Yao, Guangmin; Zhang, Yonghui; Liu, Hudan

    2016-01-01

    Aberrant activation of the NOTCH signaling pathway is crucial for the onset and progression of T cell leukemia. Yet recent studies also suggest a tumor suppressive role of NOTCH signaling in acute myeloid leukemia (AML) and reactivation of this pathway offers an attractive opportunity for anti-AML therapies. N-methylhemeanthidine chloride (NMHC) is a novel Amaryllidaceae alkaloid that we previously isolated from Zephyranthes candida, exhibiting inhibitory activities in a variety of cancer cells, particularly those from AML. Here, we report NMHC not only selectively inhibits AML cell proliferation in vitro but also hampers tumor development in a human AML xenograft model. Genome-wide gene expression profiling reveals that NMHC activates the NOTCH signaling. Combination of NMHC and recombinant human NOTCH ligand DLL4 achieves a remarkable synergistic effect on NOTCH activation. Moreover, pre-inhibition of NOTCH by overexpression of dominant negative MAML alleviates NMHC-mediated cytotoxicity in AML. Further mechanistic analysis using structure-based molecular modeling as well as biochemical assays demonstrates that NMHC docks in the hydrophobic cavity within the NOTCH1 negative regulatory region (NRR), thus promoting NOTCH1 proteolytic cleavage. Our findings thus establish NMHC as a potential NOTCH agonist that holds great promises for future development as a novel agent beneficial to patients with AML. PMID:27211848

  18. Small molecule activation of NOTCH signaling inhibits acute myeloid leukemia.

    PubMed

    Ye, Qi; Jiang, Jue; Zhan, Guanqun; Yan, Wanyao; Huang, Liang; Hu, Yufeng; Su, Hexiu; Tong, Qingyi; Yue, Ming; Li, Hua; Yao, Guangmin; Zhang, Yonghui; Liu, Hudan

    2016-01-01

    Aberrant activation of the NOTCH signaling pathway is crucial for the onset and progression of T cell leukemia. Yet recent studies also suggest a tumor suppressive role of NOTCH signaling in acute myeloid leukemia (AML) and reactivation of this pathway offers an attractive opportunity for anti-AML therapies. N-methylhemeanthidine chloride (NMHC) is a novel Amaryllidaceae alkaloid that we previously isolated from Zephyranthes candida, exhibiting inhibitory activities in a variety of cancer cells, particularly those from AML. Here, we report NMHC not only selectively inhibits AML cell proliferation in vitro but also hampers tumor development in a human AML xenograft model. Genome-wide gene expression profiling reveals that NMHC activates the NOTCH signaling. Combination of NMHC and recombinant human NOTCH ligand DLL4 achieves a remarkable synergistic effect on NOTCH activation. Moreover, pre-inhibition of NOTCH by overexpression of dominant negative MAML alleviates NMHC-mediated cytotoxicity in AML. Further mechanistic analysis using structure-based molecular modeling as well as biochemical assays demonstrates that NMHC docks in the hydrophobic cavity within the NOTCH1 negative regulatory region (NRR), thus promoting NOTCH1 proteolytic cleavage. Our findings thus establish NMHC as a potential NOTCH agonist that holds great promises for future development as a novel agent beneficial to patients with AML. PMID:27211848

  19. Lysyl oxidase propeptide inhibits smooth muscle cell signaling and proliferation

    SciTech Connect

    Hurtado, Paola A.; Vora, Siddharth; Sume, Siddika Selva; Yang, Dan; Hilaire, Cynthia St.; Guo Ying; Palamakumbura, Amitha H.; Schreiber, Barbara M.; Ravid, Katya; Trackman, Philip C.

    2008-02-01

    Lysyl oxidase is required for the normal biosynthesis and maturation of collagen and elastin. It is expressed by vascular smooth muscle cells, and its increased expression has been previously found in atherosclerosis and in models of balloon angioplasty. The lysyl oxidase propeptide (LOX-PP) has more recently been found to have biological activity as a tumor suppressor, and it inhibits Erk1/2 Map kinase activation. We reasoned that LOX-PP may have functions in normal non-transformed cells. We, therefore, investigated its effects on smooth muscle cells, focusing on important biological processes mediated by Erk1/2-dependent signaling pathways including proliferation and matrix metalloproteinase-9 (MMP-9) expression. In addition, we investigated whether evidence for accumulation of LOX-PP could be found in vivo in a femoral artery injury model. Recombinant LOX-PP was expressed and purified, and was found to inhibit primary rat aorta smooth muscle cell proliferation and DNA synthesis by more than 50%. TNF-{alpha}-stimulated MMP-9 expression and Erk1/2 activation were both significantly inhibited by LOX-PP. Immunohistochemistry studies carried out with affinity purified anti-LOX-PP antibody showed that LOX-PP epitopes were expressed at elevated levels in vascular lesions of injured arteries. These novel data suggest that LOX-PP may provide a feedback control mechanism that serves to inhibit properties associated with the development of vascular pathology.

  20. New developments in the treatment of HER2-positive breast cancer

    PubMed Central

    Nahta, Rita

    2012-01-01

    Approximately 20%–30% of metastatic breast cancers show increased expression of the human epidermal growth factor receptor-2 (HER2) tyrosine kinase. Two HER2-specific therapies are currently approved for clinical treatment of patients with HER2-overexpressing metastatic breast cancer. Trastuzumab is a monoclonal antibody against HER2 and is approved for first-line treatment of HER2-positive metastatic breast cancer. Lapatinib is a small molecule dual inhibitor of epidermal growth factor receptor and HER2 tyrosine kinases, and is approved for trastuzumab-refractory disease. Although trastuzumab is a highly effective therapy for patients with HER2-overexpressing metastatic breast cancer, a significant number of patients in the initial clinical trials of trastuzumab monotherapy showed resistance to trastuzumab-based therapy. Further, among those who did respond, the initial trials indicated that the median time to progression was less than 1 year. Similarly, lapatinib is effective in a subset of trastuzumab-refractory cases, but the majority of patients display resistance. This review discusses the multiple molecular mechanisms of resistance that have been proposed in the literature. In addition, novel agents that are being tested for efficacy against HER2-positive breast cancer, including the antibodies pertuzumab and trastuzumab-DM1 and the immunotoxin affitoxin, are reviewed. The introduction of trastuzumab has revolutionized the clinical care of patients with HER2-positive metastatic breast cancer and has resulted in dramatic reductions in recurrences of early-stage HER2-positive breast cancer. The development and implementation of gene- and protein-based assays that measure potential molecular predictors of trastuzumab resistance will allow individualization of HER2-targeted therapeutic approaches, and may ultimately improve treatment of HER2-positive breast cancer. PMID:23869176

  1. Relationship Between HER2 Status and Prognosis in Women With Brain Metastases From Breast Cancer

    SciTech Connect

    Xu Zhiyuan; Marko, Nicholas F.; Chao, Sam T.; Angelov, Lilyana; Vogelbaum, Michael A.; Suh, John H.; Barnett, Gene H.; Weil, Robert J.

    2012-04-01

    Purpose: To analyze factors affecting outcomes in breast cancer patients with brain metastases (BM) and characterize the role of HER2 status. Methods and Materials: We identified 264 breast cancer patients treated between 1999 and 2008 for BM. HER2 status was known definitively for 172 patients and was used to define cohorts in which survival and risk factors were analyzed. Results: Kaplan-Meier survival analysis demonstrated improved mean overall survival (105.7 vs. 74.3 months, p < 0.02), survival after diagnosis of BM (neurologic survival, NS) (32.2 vs. 18.9 months, p < 0.01), and survival after treatment with stereotactic radiosurgery (RS) (31.3 vs. 14.1, p < 0.01) in HER2+ patients relative to those with HER2- breast cancer. HER2+ status was an independent, positive prognostic factor for survival on univariate and multivariate hazard analysis (hazard ratio: overall survival = 0.66, 0.18; NS = 0.50, 0.34). Additionally, subgroup analysis suggests that stereotactic radiosurgery may be of particular benefit in patients with HER2+ tumors. Conclusions: Overall survival, NS, and RS are improved in patients with HER2+ tumors, relative to those with HER2- lesions, and HER2 amplification is independently associated with increased survival in patients with BM from breast cancer. Our findings suggest that the prognosis of HER2+ patients may be better than that of otherwise similar patients who are HER2- and that stereotactic radiosurgery may be beneficial for some patients with HER2+ lesions.

  2. Crocetinic acid inhibits hedgehog signaling to inhibit pancreatic cancer stem cells

    PubMed Central

    Rangarajan, Parthasarathy; Subramaniam, Dharmalingam; Paul, Santanu; Kwatra, Deep; Palaniyandi, Kanagaraj; Islam, Shamima; Harihar, Sitaram; Ramalingam, Satish; Gutheil, William; Putty, Sandeep; Pradhan, Rohan; Padhye, Subhash; Welch, Danny R.; Anant, Shrikant; Dhar, Animesh

    2015-01-01

    Pancreatic cancer is the fourth leading cause of cancer deaths in the US and no significant treatment is currently available. Here, we describe the effect of crocetinic acid, which we purified from commercial saffron compound crocetin using high performance liquid chromatography. Crocetinic acid inhibits proliferation of pancreatic cancer cell lines in a dose- and time-dependent manner. In addition, it induced apoptosis. Moreover, the compound significantly inhibited epidermal growth factor receptor and Akt phosphorylation. Furthermore, crocetinic acid decreased the number and size of the pancospheres in a dose-dependent manner, and suppressed the expression of the marker protein DCLK-1 (Doublecortin Calcium/Calmodulin-Dependent Kinase-1) suggesting that crocetinic acid targets cancer stem cells (CSC). To understand the mechanism of CSC inhibition, the signaling pathways affected by purified crocetinic acid were dissected. Sonic hedgehog (Shh) upon binding to its cognate receptor patched, allows smoothened to accumulate and activate Gli transcription factor. Crocetinic acid inhibited the expression of both Shh and smoothened. Finally, these data were confirmed in vivo where the compound at a dose of 0.5 mg/Kg bw suppressed growth of tumor xenografts. Collectively, these data suggest that purified crocetinic acid inhibits pancreatic CSC, thereby inhibiting pancreatic tumorigenesis. PMID:26317547

  3. Crocetinic acid inhibits hedgehog signaling to inhibit pancreatic cancer stem cells.

    PubMed

    Rangarajan, Parthasarathy; Subramaniam, Dharmalingam; Paul, Santanu; Kwatra, Deep; Palaniyandi, Kanagaraj; Islam, Shamima; Harihar, Sitaram; Ramalingam, Satish; Gutheil, William; Putty, Sandeep; Pradhan, Rohan; Padhye, Subhash; Welch, Danny R; Anant, Shrikant; Dhar, Animesh

    2015-09-29

    Pancreatic cancer is the fourth leading cause of cancer deaths in the US and no significant treatment is currently available. Here, we describe the effect of crocetinic acid, which we purified from commercial saffron compound crocetin using high performance liquid chromatography. Crocetinic acid inhibits proliferation of pancreatic cancer cell lines in a dose- and time-dependent manner. In addition, it induced apoptosis. Moreover, the compound significantly inhibited epidermal growth factor receptor and Akt phosphorylation. Furthermore, crocetinic acid decreased the number and size of the pancospheres in a dose-dependent manner, and suppressed the expression of the marker protein DCLK-1 (Doublecortin Calcium/Calmodulin-Dependent Kinase-1) suggesting that crocetinic acid targets cancer stem cells (CSC). To understand the mechanism of CSC inhibition, the signaling pathways affected by purified crocetinic acid were dissected. Sonic hedgehog (Shh) upon binding to its cognate receptor patched, allows smoothened to accumulate and activate Gli transcription factor. Crocetinic acid inhibited the expression of both Shh and smoothened. Finally, these data were confirmed in vivo where the compound at a dose of 0.5 mg/Kg bw suppressed growth of tumor xenografts. Collectively, these data suggest that purified crocetinic acid inhibits pancreatic CSC, thereby inhibiting pancreatic tumorigenesis. PMID:26317547

  4. Silibinin Preferentially Radiosensitizes Prostate Cancer by Inhibiting DNA Repair Signaling.

    PubMed

    Nambiar, Dhanya K; Rajamani, Paulraj; Deep, Gagan; Jain, Anil K; Agarwal, Rajesh; Singh, Rana P

    2015-12-01

    Radiotherapy, a frequent mode of cancer treatment, is often restricted by dose-related toxicity and development of therapeutic resistance. To develop a novel and selective radiosensitizer, we studied the radiosensitizing effects and associated mechanisms of silibinin in prostate cancer. The radiosensitizing effect of silibinin with ionizing radiation (IR) was assessed on radioresistant prostate cancer cell lines by clonogenic, cell cycle, cell death, and DNA repair assays. Tumor xenograft growth, immunohistochemical (IHC) analysis of tumor tissues, and toxicity-related parameters were measured in vivo. Silibinin (25 μmol/L) enhanced IR (2.5-10 Gy)-caused inhibition (up to 96%, P < 0.001) of colony formation selectively in prostate cancer cells, and prolonged and enhanced IR-caused G2-M arrest, apoptosis, and ROS production. Mechanistically, silibinin inhibited IR-induced DNA repair (ATM and Chk1/2) and EGFR signaling and attenuated the levels of antiapoptotic proteins. Specifically, silibinin suppressed IR-induced nuclear translocation of EGFR and DNA-PK, an important mediator of DSB repair, leading to an increased number of γ-H2AX (ser139) foci suggesting lesser DNA repair. In vivo, silibinin strongly radiosensitized DU145 tumor xenograft inhibition (84%, P < 0.01) with higher apoptotic response (10-fold, P < 0.01) and reduced repair of DNA damage, and rescued the mice from IR-induced toxicity and hematopoietic injury. Overall, silibinin enhanced the radiotherapeutic response via suppressing IR-induced prosurvival signaling and DSB repair by inhibiting nuclear translocation of EGFR and DNA-PK. Because silibinin is already in phase II clinical trial for prostate cancer patients, the present finding has translational relevance for radioresistant prostate cancer. PMID:26516160

  5. Quantum dots-based double-color imaging of HER2 positive breast cancer invasion

    SciTech Connect

    Liu, Xiu-Li; Peng, Chun-Wei; Chen, Chuang; Yang, Xue-Qin; Hu, Ming-Bai; Xia, He-Shun; Liu, Shao-Ping; and others

    2011-06-10

    Highlights: {yields} HER2 level is closely related to the biologic behaviors of breast cancer cells. {yields} A new method to simultaneously image HER2 and type IV collagen was established. {yields} HER2 status and type IV collagen degradation predict breast cancer invasion. {yields} The complex interactions between tumor and its environment were revealed. -- Abstract: It has been well recognized that human epidermal growth factor receptor 2 (HER2) level in breast cancer (BC) is closely related to the malignant biologic behaviors of the tumor, including invasion and metastasis. Yet, there has been a lack of directly observable evidence to support such notion. Here we report a quantum dots (QDs)-based double-color imaging technique to simultaneously show the HER2 level on BC cells and the type IV collagen in the tumor matrix. In benign breast tumor, the type IV collagen was intact. With the increasing of HER2 expression level, there has been a progressive decrease in type IV collagen around the cancer nest. At HER2 (3+) expression level, there has virtually been a total destruction of type IV collagen. Moreover, HER2 (3+) BC cells also show direct invasion into the blood vessels. This novel imaging method provides direct observable evidence to support the theory that the HER2 expression level is directly related to BC invasion.

  6. HER2 status in advanced gastric carcinoma: A retrospective multicentric analysis from Sicily

    PubMed Central

    IENI, A.; BARRESI, V.; GIUFFRÈ, G.; CARUSO, R.A.; LANZAFAME, S.; VILLARI, L.; SALOMONE, E.; ROZ, E.; CABIBI, D.; FRANCO, V.; CERTO, G.; LABATE, A.; NAGAR, C.; MAGLIOLO, E.; BROGGI, B.; FAZZARI, C.; ITALIA, F.; TUCCARI, G.

    2013-01-01

    According to the ToGA trial, HER2 has been shown to be predictive for the success of treatment with trastuzumab in advanced gastric cancer (AGC). A number of studies have analyzed HER-2/neu overexpression in gastric carcinoma and identified the rate of HER2 positivity to be markedly varied. To date, the prevalence of HER2 overexpression in Sicilian people with AGC is unknown. Therefore, in the present study, a retrospective immunohistochemical analysis of HER2 was performed in a cohort of 304 AGC samples that were obtained from the archives of 10 Sicilian anatomopathological diagnostic units in order to verify the positive rate of HER2-positive cases. Furthermore, the characteristics of histotype, grade, stage and Ki-67 expression were also analyzed. HER2 overexpression was encountered in 17.43% of all the gastric adenocarcinomas, which was consistent with the results that have been reported elsewhere in the literature. A progressive increase in HER2 overexpression was observed, from the poorly cohesive histotype to the tubular adenocarcinomas and gastric hepatoid adenocarcinomas. HER2 overexpression was significantly associated with a high grade, advanced stage and high Ki-67 labeling index. Further investigations performed jointly by pathologists and oncologists within the geographical area of the present study should confirm that the association of trastuzumab with chemotherapy results in an improvement of survival in patients with AGC. PMID:24260051

  7. In vitro antiproliferative effect of trastuzumab (Herceptin(®)) combined with cetuximab (Erbitux(®)) in a model of human non-small cell lung cancer expressing EGFR and HER2.

    PubMed

    Privitera, G; Luca, T; Musso, N; Vancheri, C; Crimi, N; Barresi, V; Condorelli, D; Castorina, S

    2016-05-01

    Lung cancer is the leading cause of cancer death. For this reason, new therapies are needed for the treatment of this devastating disease. In this study, we investigated the effects of combining cetuximab and the trastuzumab on the growth of a model of human non-small cell lung carcinoma cell line (A549). The results were compared with those obtained from a human lung squamous carcinoma cell line (NCI-H226). Both cell lines were treated with cetuximab and trastuzumab, alone or in combination, at various concentrations, for 24, 48 and 72 h. Cell proliferation was measured by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. EGFR and HER-2 mRNA expression was detected by reverse transcription polymerase chain reaction, and the gene amplification status of receptors was evaluated by fluorescence in situ hybridisation. The colorimetric proliferation assay showed that trastuzumab combined with cetuximab significantly inhibited A549 cells at a dose of 40 μg/ml after 72 h of treatment (p < 0.05), while no time-dose dependent inhibition was observed in NCI-H226 cells. The combined treatment influenced both levels of EGFR and HER-2 mRNA in A549 cells and only EGFR mRNA levels in NCI-H226 cells. Fluorescence in situ hybridisation showed that both cell lines were aneuploid for the two genes with equally increased EGFR and CEN7 signals, as well as HER-2 and CEN17 signals, indicating a condition of polysomy without amplification. The preliminary results of this study encourage further investigations to elucidate the downstream events involved and to understand how these mechanisms influence non-small cell lung cancers growth. PMID:25716471

  8. The in vitro influences of epidermal growth factor and heregulin-β1 on the efficacy of trastuzumab used in Her-2 positive breast adenocarcinoma

    PubMed Central

    2013-01-01

    Background Human epidermal growth factor receptor-2 (Her-2) is over expressed in approximately 25-30% of all primary breast tumors resulting in a distinctive breast cancer subtype associated with a poor prognosis and a decrease in overall survival. Trastuzumab (Herceptin®), an anti-Her-2 monoclonal antibody, has dramatically altered the prognosis of Her-2 positive breast cancer. Trastuzumab is, however, associated with primary and acquired resistance. Aim and methods To investigate the in-vitro effects of trastuzumab on cell viability (tetrazolium conversion assay), cell cycling (propidium iodide staining), apoptosis (executioner caspases and annexin-V) and relative surface Her-2 receptor expression (anti-Her-2 affibody molecule) in Her-2-positive (SK-Br-3) and oestrogen receptor positive (MCF-7) breast adenocarcinoma cells and to determine potential augmentation of these effects by two endogenous ligands, epidermal growth factor (EGF) and heregulin-β1 (HRG- β1). Results Cell viability was decreased in SK-Br-3 cells by exposure to trastuzumab. This was associated with G1 accumulation and decreased relative surface Her-2 receptor density, supporting the cytostatic nature of trastuzumab in vitro. SK-Br-3 cells exposed to EGF and heregulin-β1 produced differential cell responses alone and in combination with trastuzumab, in some instances augmenting cell viability and cell cycling. Relative surface Her-2 receptor density was reduced substantially by trastuzumab, EGF and heregulin-β1. These reductions were amplified when ligands were used in combination with trastuzumab. Conclusion Cell type specific interactions of endogenous ligands appear to be dependent on absolute Her-receptor expression and cross activation of signaling pathways. This supports the notion that receptor density of Her-family members and multiplicity of growth ligands are of mutual importance in breast cancer cell proliferation and therefore also in resistance associated with trastuzumab. PMID

  9. A different immunologic profile characterizes patients with HER-2-overexpressing and HER-2-negative locally advanced breast cancer: implications for immune-based therapies

    PubMed Central

    2011-01-01

    Introduction The clinical efficacy of trastuzumab and taxanes is at least partly related to their ability to mediate or promote antitumor immune responses. On these grounds, a careful analysis of basal immune profile may be capital to dissect the heterogeneity of clinical responses to these drugs in patients with locally advanced breast cancer undergoing neoadjuvant chemotherapy. Methods Blood samples were collected from 61 locally advanced breast cancers (36 HER2- and 25 HER2+) at diagnosis and from 23 healthy women. Immunophenotypic profiling of circulating and intratumor immune cells, including regulatory T (Treg) cells, was assessed by flow cytometry and immunohistochemistry, respectively. Serum levels of 10 different cytokines were assessed by multiplex immunoassays. CD8+ T cell responses to multiple tumor-associated antigens (TAA) were evaluated by IFN-γ-enzyme-linked immunosorbent spot (ELISPOT). The Student's t test for two tailed distributions and the Wilcoxon two-sample test were used for the statistical analysis of the data. Results The proportion of circulating immune effectors was similar in HER2+ patients and healthy donors, whereas higher percentages of natural killer and Treg cells and a lower CD4+/CD8+ T cell ratio (with a prevalence of naïve and central memory CD8+ T cells) were observed in HER2- cases. Higher numbers of circulating CD8+ T cells specific for several HLA-A*0201-restricted TAA-derived peptides were observed in HER2+ cases, together with a higher prevalence of intratumor CD8+ T cells. Serum cytokine profile of HER2+ patients was similar to that of controls, whereas HER2- cases showed significantly lower cytokine amounts compared to healthy women (IL-2, IL-8, IL-6) and HER2+ cases (IL-2, IL-1β, IL-8, IL-6, IL-10). Conclusions Compared to HER2- cases, patients with HER2-overexpressing locally advanced breast cancer show a more limited tumor-related immune suppression. This may account for the clinical benefit achieved in this subset

  10. Human Epidermal Growth Factor Receptor 2 (HER-2/neu)-Directed Therapy for Rare Metastatic Epithelial Tumors with HER-2 Amplification

    PubMed Central

    Shin, Daniel Sanghoon; Sherry, Timothy; Kallen, Michael E.; Wong, Steven; Drakaki, Alexandra

    2016-01-01

    Case 1 A 67-year-old Asian female was diagnosed with locally advanced high-grade salivary duct carcinoma in June 2011. Molecular analysis revealed human epidermal growth factor receptor 2 (HER-2) amplification. She received adjuvant therapy with carboplatin/paclitaxel/ trastuzumab and maintenance of trastuzumab. Upon disease progression, trastuzumab could not be continued due to lack of financial coverage. Instead, she was treated with compassionate use of lapatinib from April 2013 and standard 5-fluorouracil. Her disease ultimately progressed and she expired later in 2013. Case 2 A 68-year-old Asian male was diagnosed with extramammary Paget's disease of the scrotum with HER-2 amplification in May 2011. He received 6 cycles of adjuvant trastuzumab/docetaxel/carboplatin followed by maintenance trastuzumab, which was changed to compassionate use of lapatinib as his insurance did not cover further administration of trastuzumab. He showed clinical benefits from single-agent lapatinib and a combination of lapatinib/capecitabine upon progression to the single-agent lapatinib. Ultimately, he was started on ado-trastuzumab emtansine, which was approved at that time by the FDA for HER-2-positive breast cancer progressed on trastuzumab. He is having clinical and radiographic complete response based on current imaging and normalization of his tumor markers. Conclusion HER-2-targeted therapy should be considered for tumors with HER-2 amplification. In our case series, we would like to emphasize this approach in other rare histologies. Specifically, our patient with extramammary Paget's disease of the scrotum represents the first reported case of a non-breast, non-gastric tumor with HER-2 overexpression with complete clinical and radiographic response to HER-2-targeted therapy PMID:27403128

  11. HER2-positive patients receiving trastuzumab treatment have a comparable prognosis with HER2-negative advanced gastric cancer patients: a prospective cohort observation.

    PubMed

    Qiu, Miao-Zhen; Li, Qian; Wang, Zhi-Qiang; Liu, Tian-Shu; Liu, Qing; Wei, Xiao-Li; Jin, Ying; Wang, De-Shen; Ren, Chao; Bai, Long; Zhang, Dong-Sheng; Wang, Feng-Hua; Li, Yu-Hong; Xu, Rui-Hua

    2014-05-15

    The monoclonal antibody trastuzumab has brought survival benefit to patients with advanced gastric cancer (AGC) that have human epidermal growth factor receptor 2 (HER2) over expression or amplification. This study was designed to compare the clinical outcomes of HER2-negative and HER2-positive AGC patients with or without trastuzumab treatment. There were three groups of patients enrolled for analysis. Group A was 51 HER2-positive AGC patients treated with trastuzumab and chemotherapy; group B was a matched control group of 47 HER2-positive patients who received chemotherapy only; group C was a matched group of 251 HER2-negative patients who received chemotherapy. All the patients were enrolled at Sun Yat-sen University Cancer Center or Zhongshan Hospital, Fudan University between January 2010 and December 2012. The primary endpoint was overall survival (OS). The Kaplan-Meier method and log-rank test were used for survival analysis. The median duration of follow-up was 13.5 months (range 5-18.6 months). The median OS of these three groups of patients was 14.8 months, 11.3 months and 14.4 months respectively (p < 0.001). The survival difference between group A and B was significant, p < 0.001. Similarly, there was significant difference between group B and C, p < 0.001. Moreover the survival between group A and C was comparable, p = 0.281. The median progression-free survival for these three groups was 7.4, 6.0 and 7.2 months. Multivariate analysis confirmed that trastuzumab treatment was an independent prognostic factor in group A and B patients (p = 0.017). HER2 positive was an independent adverse prognostic factor in group B and C patients (p = 0.013). PMID:24155030

  12. HER2 expression in primary gastric cancers and paired synchronous lymph node and liver metastases. A possible road to target HER2 with radionuclides.

    PubMed

    Wei, Qichun; Xu, Jing; Shen, Li; Fu, Xianhua; Zhang, Bicheng; Zhou, Xiaofeng; Carlsson, Jorgen

    2014-07-01

    Resistance has been reported to human epidermal growth factor receptor 2 (HER2)-targeted therapy with the tyrosine kinase inhibitor lapatinib and the antibody trastuzumab in metastatic gastric cancer. An alternative or complement might be to target the extracellular domain of HER2 with therapy-effective radionuclides. The fraction of patients with HER2 expression in primary tumors and major metastatic sites, e.g., lymph nodes and liver, was analyzed to evaluate the potential for such therapy. Samples from primary tumors and lymph node and liver metastases were taken from each patient within a few hours, and to our knowledge, such sampling is unique. The number of analyzed cases was therefore limited, since patients that had received preoperative radiotherapy, chemotherapy, or HER2-targeted therapy were excluded. From a large number of considered patients, only 29 could be included for HER2 analysis. Intracellular mutations were not analyzed since they are assumed to have no or minor effect on the extracellular binding of molecules that deliver radionuclides. HER2 was positive in nearly 52 % of the primary tumors, and these expressed HER2 in corresponding lymph node and liver metastases in 93 and 100 % of the cases, respectively. Similar values for primary tumors and also good concordance with metastases have been indicated in the literature. Thus, relevant radionuclides and targeting molecules for nuclear medicine-based noninvasive, whole-body receptor analysis, dose planning, and therapy can be applied for many patients; see "Discussion" Hopefully, more patients can then be treated with curative instead of palliative intention. PMID:24643685

  13. Expression profile analysis of long noncoding RNA in HER-2-enriched subtype breast cancer by next-generation sequencing and bioinformatics

    PubMed Central

    Yang, Fan; Lyu, Shixu; Dong, Siyang; Liu, Yehuan; Zhang, Xiaohua; Wang, Ouchen

    2016-01-01

    Background Human epidermal growth factor receptor 2 (HER-2)-enriched subtype breast cancer is associated with a more aggressive phenotype and shorter survival time. Long non-coding RNAs (LncRNAs) have essential roles in tumorigenesis and occupy a central place in cancer progression. Notably, few studies have focused on the dysregulation of LncRNAs in the HER-2-enriched subtype breast cancer. In this study, we analyzed the expression profile of LncRNAs and mRNAs in this particular subtype of breast cancer. Methods Seven pairs of HER-2-enriched subtype breast cancer and normal tissue were sequenced. We screened out differently expressed genes and measured the correlation of the expression levels of dysregulated LncRNAs and HER-2 by Pearson’s correlation coefficient analysis. Gene ontology analysis and pathway analysis were used to understand the biological roles of these differently expressed genes. Pathway act network and coexpression network were constructed. Results More than 1,300 LncRNAs and 2,800 mRNAs, which were significantly differently expressed, were identified. Among these LncRNAs, AFAP1-AS1 was the most dysregulated LncRNA, while ORM2 was the most dysregulated mRNA. LOC100288637 had the highest positive correlation coefficient of 0.93 with HER-2, while RPL13P5 had the highest negative correlation coefficient of −0.87. The pathway act network showed that MAPK signaling pathway, PI3K-Akt signaling pathway, metabolic pathways, cell cycle, and regulation of actin cytoskeleton were highly related with HER-2-enriched subtype breast cancer. Coexpression network recognized LINC00636, LINC01405, ADARB2-AS1, ST8SIA6-AS1, LINC00511, and DPP10-AS1 as core genes. Conclusion These results analyze the functions of LncRNAs and provide useful information for exploring candidate therapeutic targets and new molecular biomarkers for HER-2-enriched subtype breast cancer. PMID:26929647

  14. Predicting discordant HER2 results in ipsilateral synchronous invasive breast carcinomas: experience from a single institution.

    PubMed

    Chou, Shaun; Khan, Tayyaba; Mahajan, Hema; Pathmanathan, Nirmala

    2015-12-01

    With the emergence of multiple lines of highly effective Human Epidermal Growth Factor Receptor 2 (HER2) directed therapy, accurate identification of HER2 positive tumour has become a critical aspect in the histopathological analysis of breast cancers. Multifocal invasive breast carcinomas are relatively common, and given the aggressive inherent biology of HER2 positive disease, identification of even small tumours with HER2 positive status may be of importance for treatment planning. There are currently no clear guidelines as to whether all of these foci should be tested for HER2 status. We reviewed the results of 172 patients in whom HER2 in situ hybridisation (ISH) testing was performed on at least two ipsilateral synchronous invasive carcinomas. Discordant results in different invasive foci were relatively uncommon and occurred in only eight (5%) of the 172 patients. This showed a statistically significant correlation with similarly discordant oestrogen receptor (ER) results. In addition HER2 discordance was more likely amongst different tumour foci if these arose in distinct and separate areas of DCIS. An algorithm based on a combination of College of American Pathologists (CAP) recommendation for HER2 testing, differing ER status and background DCIS profile may be useful in detecting these discordant cases. PMID:26517643

  15. Design, synthesis and characterization of peptidomimetic conjugate of BODIPY targeting HER2 protein extracellular domain

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Among the EGFRs, HER2 is a major heterodimer partner and also has important implications in the formation of particular tumors. Interaction of HER2 protein with other EGFR proteins can be modulated by small molecule ligands and, hence, these protein-protein interactions play a key role in biochemica...

  16. Targeting HER2+ breast cancer cells: lysosomal accumulation of anti-HER2 antibodies is influenced by antibody binding site and conjugation to polymeric nanoparticles.

    PubMed

    Owen, Shawn C; Patel, Nish; Logie, Jennifer; Pan, Guohua; Persson, Helena; Moffat, Jason; Sidhu, Sachdev S; Shoichet, Molly S

    2013-12-10

    Humanized monoclonal antibodies (mAb) against HER2 are being engineered to treat cancer. We utilized phage-display technology to generate a novel anti-HER2 mAb (named 73JIgG) that binds an epitope of HER2 distinct from that of trastuzumab. Although these mAbs bind to the same cell surface receptor, they have different cell distribution profiles. After 3h of incubation, almost 10% of the total 73JIgG reaches the lysosome compared to less than 3% of trastuzumab. Interestingly, 73JIgG disassociates from HER2 whereas trastuzumab remains bound to the receptor. Importantly, HER2 distribution is not affected by the antibody binding epitope, thus negating this mechanism as the reason for the difference in intracellular trafficking of 73JIgG versus trastuzumab. Each of trastuzumab and 73JIgG was chemically-modified with either a small molecule or polymeric nanoparticle to better understand the influence of conjugation on cellular localization. Relative to antibody alone, antibody-nanoparticle conjugates resulted in a higher concentration of antibodies in the lysosome whereas antibody-small molecule conjugates did not affect cell trafficking to the lysosome. Given the importance of lysosomal targeting, these results demonstrate the importance of understanding the influence of the antibody-conjugate on cell trafficking for ultimate optimization of treatment selection. PMID:23880472

  17. HER2-positive, trastuzumab-resistant metastatic esophageal cancer presenting with brain metastasis after durable response to dual HER2 blockade: a case report

    PubMed Central

    Gelbspan, Deborah; Weitz, David; Markman, Maurie; Quan, Walter

    2014-01-01

    We here report a case of a patient diagnosed with human epithelial growth factor receptor 2 (HER2)-amplified esophageal adenocarcinoma. The patient responded well to trastuzumab-based chemotherapy initially, but progressed with liver metastases. Her treatment was then switched to dual HER2 blockade with both trastuzumab and lapatinib in combination with capecitabine. She tolerated therapy and responded remarkably well with radiographic resolution of liver metastases. Unfortunately, she developed multiple brain metastases in the absence of extracranial progression. Discordant negative expression of HER2 and subclonal mutations in brain lesions were discovered, which, at least in part, explained her brain metastases in the presence of capecitabine and lapatinib, as both agents are known to be able to cross the blood brain barrier. The potential mechanism for dual HER2 blockade is discussed in the context of HER2-positive, trastuzumab-resistant, advanced esophageal cancer. The incidence of brain metastasis in advanced gastro-esophageal cancer has been reported to be extremely low, but is expected to increase with more effective systemic therapy. The intratumoral heterogeneity between the metastases, local recurrences and the primary tumor is definitely noteworthy. PMID:25436131

  18. Pentoxifylline inhibits liver fibrosis via hedgehog signaling pathway.

    PubMed

    Li, Hui; Hua, Juan; Guo, Chun-Xia; Wang, Wei-Xian; Wang, Bao-Ju; Yang, Dong-Liang; Wei, Ping; Lu, Yin-Ping

    2016-06-01

    Infection of schistosomiasis japonica may eventually lead to liver fibrosis, and no effective antifibrotic therapies are available but liver transplantation. Hedgehog (HH) signaling pathway has been involved in the process and is a promising target for treating liver fibrosis. This study aimed to explore the effects of pentoxifylline (PTX) on liver fibrosis induced by schistosoma japonicum infection by inhibiting the HH signaling pathway. Phorbol12-myristate13-acetate (PMA) was used to induce human acute mononuclear leukemia cells THP-1 to differentiate into macrophages. The THP-1-derived macrophages were stimulated by soluble egg antigen (SEA), and the culture supernatants were collected for detection of activation of macrophages. Cell Counting Kit-8 (CCK-8) was used to detect the cytotoxicity of the culture supernatant and PTX on the LX-2 cells. The LX-2 cells were administered with activated culture supernatant from macrophages and(or) PTX to detect the transforming growth factor-β gene expression. The mRNA expression of shh and gli-1, key parts in HH signaling pathway, was detected. The mRNA expression of shh and gli-1 was increased in LX-2 cells treated with activated macrophages-derived culture supernatant, suggesting HH signaling pathway may play a key role in the activation process of hepatic stellate cells (HSCs). The expression of these genes decreased in LX-2 cells co-cultured with both activated macrophages-derived culture supernatant and PTX, indicating PTX could suppress the activation process of HSCs. In conclusion, these data provide evidence that PTX prevents liver fibrogenesis in vitro by the suppression of HH signaling pathway. PMID:27376806

  19. HER2 as a Therapeutic Target in Head and Neck Squamous Cell Carcinoma

    PubMed Central

    Pollock, Netanya I.; Grandis, Jennifer R.

    2014-01-01

    The majority of patients with head and neck squamous cell carcinoma (HNSCC) present with advanced-stage disease. Current standard of care is surgery followed by adjuvant radiation therapy with or without chemotherapy or chemoradiation alone. The addition of cetuximab for the treatment of patients with locally advanced or recurrent/metastatic HNSCC has improved overall survival and locoregional control; however, responses are often modest, and treatment resistance is common. A variety of therapeutic strategies are being explored to overcome cetuximab resistance by blocking candidate proteins implicated in resistance mechanisms such as HER2. Several HER2 inhibitors are in clinical development for HNSCC, and HER2-targeted therapy has been approved for several cancers. This review focuses on the biology of HER2, its role in cancer development, and the rationale for clinical investigation of HER2 targeting in HNSCC. PMID:25424855

  20. Structure-based Design of Peptides with High Affinity and Specificity to HER2 Positive Tumors

    PubMed Central

    Geng, Lingling; Wang, Zihua; Yang, Xiaoliang; Li, Dan; Lian, Wenxi; Xiang, Zhichu; Wang, Weizhi; Bu, Xiangli; Lai, Wenjia; Hu, Zhiyuan; Fang, Qiaojun

    2015-01-01

    To identify peptides with high affinity and specificity against human epidermal growth factor receptor 2 (HER2), a series of peptides were designed based on the structure of HER2 and its Z(HER2:342) affibody. By using a combination protocol of molecular dynamics modeling, MM/GBSA binding free energy calculations, and binding free energy decomposition analysis, two novel peptides with 27 residues, pep27 and pep27-24M, were successfully obtained. Immunocytochemistry and flow cytometry analysis verified that both peptides can specifically bind to the extracellular domain of HER2 protein at cellular level. The Surface Plasmon Resonance imaging (SPRi) analysis showed that dissociation constants (KD) of these two peptides were around 300 nmol/L. Furthermore, fluorescence imaging of peptides against nude mice xenografted with SKBR3 cells indicated that both peptides have strong affinity and high specificity to HER2 positive tumors. PMID:26284145

  1. Improved Aptamers for the Diagnosis and Potential Treatment of HER2-Positive Cancer

    PubMed Central

    Gijs, Marlies; Penner, Gregory; Blackler, Garth B.; Impens, Nathalie R.E.N.; Baatout, Sarah; Luxen, André; Aerts, An M.

    2016-01-01

    Aptamers provide a potential source of alternative targeting molecules for existing antibody diagnostics and therapeutics. In this work, we selected novel DNA aptamers targeting the HER2 receptor by an adherent whole-cell SELEX approach. Individual aptamers were identified by next generation sequencing and bioinformatics analysis. Two aptamers, HeA2_1 and HeA2_3, were shown to bind the HER2 protein with affinities in the nanomolar range. In addition, both aptamers were able to bind with high specificity to HER2-overexpressing cells and HER2-positive tumor tissue samples. Furthermore, we demonstrated that aptamer HeA2_3 is being internalized into cancer cells and has an inhibitory effect on cancer cell growth and viability. In the end, we selected novel DNA aptamers with great potential for the diagnosis and possible treatment of HER2-positive cancer. PMID:27213406

  2. Structure-based Design of Peptides with High Affinity and Specificity to HER2 Positive Tumors.

    PubMed

    Geng, Lingling; Wang, Zihua; Yang, Xiaoliang; Li, Dan; Lian, Wenxi; Xiang, Zhichu; Wang, Weizhi; Bu, Xiangli; Lai, Wenjia; Hu, Zhiyuan; Fang, Qiaojun

    2015-01-01

    To identify peptides with high affinity and specificity against human epidermal growth factor receptor 2 (HER2), a series of peptides were designed based on the structure of HER2 and its Z(HER2:342) affibody. By using a combination protocol of molecular dynamics modeling, MM/GBSA binding free energy calculations, and binding free energy decomposition analysis, two novel peptides with 27 residues, pep27 and pep27-24M, were successfully obtained. Immunocytochemistry and flow cytometry analysis verified that both peptides can specifically bind to the extracellular domain of HER2 protein at cellular level. The Surface Plasmon Resonance imaging (SPRi) analysis showed that dissociation constants (K D) of these two peptides were around 300 nmol/L. Furthermore, fluorescence imaging of peptides against nude mice xenografted with SKBR3 cells indicated that both peptides have strong affinity and high specificity to HER2 positive tumors. PMID:26284145

  3. Predictive biomarkers in the treatment of HER2-positive breast cancer: an ongoing challenge.

    PubMed

    Triulzi, Tiziana; Bianchi, Giulia Valeria; Tagliabue, Elda

    2016-06-01

    The transmembrane tyrosine kinase receptor HER2 is overexpressed in 20% of invasive breast cancers and is associated with more aggressive disease. Until the advent of targeted agents, HER2 was associated with worse outcome. Trastuzumab, a recombinant humanized anti-HER2 monoclonal antibody, combined with chemotherapy improves disease-free and overall survival in both primary and metastatic tumors and represents a foundation of care for patients with HER2-positive breast cancers. However, a sizeable number of patients do not respond to this reagent, indicating the need for a biomarker able to recognize resistant tumors. Here, we review various studies on mechanisms of action and resistance to trastuzumab that have proven relevant in understanding how tumor care can be tailored to all HER2-positive patients. PMID:27007660

  4. WNT signaling drives cholangiocarcinoma growth and can be pharmacologically inhibited

    PubMed Central

    Boulter, Luke; Guest, Rachel V.; Kendall, Timothy J.; Wilson, David H.; Wojtacha, Davina; Robson, Andrew J.; Ridgway, Rachel A.; Samuel, Kay; Van Rooijen, Nico; Barry, Simon T.; Wigmore, Stephen J.; Sansom, Owen J.; Forbes, Stuart J.

    2015-01-01

    Cholangiocarcinoma (CC) is typically diagnosed at an advanced stage and is refractory to surgical intervention and chemotherapy. Despite a global increase in the incidence of CC, little progress has been made toward the development of treatments for this cancer. Here we utilized human tissue; CC cell xenografts; a p53-deficient transgenic mouse model; and a non-transgenic, chemically induced rat model of CC that accurately reflects both the inflammatory and regenerative background associated with human CC pathology. Using these systems, we determined that the WNT pathway is highly activated in CCs and that inflammatory macrophages are required to establish this WNT-high state in vivo. Moreover, depletion of macrophages or inhibition of WNT signaling with one of two small molecule WNT inhibitors in mouse and rat CC models markedly reduced CC proliferation and increased apoptosis, resulting in tumor regression. Together, these results demonstrate that enhanced WNT signaling is a characteristic of CC and suggest that targeting WNT signaling pathways has potential as a therapeutic strategy for CC. PMID:25689248

  5. Intestinal epithelial vitamin D receptor signaling inhibits experimental colitis

    PubMed Central

    Liu, Weicheng; Chen, Yunzi; Golan, Maya Aharoni; Annunziata, Maria L.; Du, Jie; Dougherty, Urszula; Kong, Juan; Musch, Mark; Huang, Yong; Pekow, Joel; Zheng, Changqing; Bissonnette, Marc; Hanauer, Stephen B.; Li, Yan Chun

    2013-01-01

    The inhibitory effects of vitamin D on colitis have been previously documented. Global vitamin D receptor (VDR) deletion exaggerates colitis, but the relative anticolitic contribution of epithelial and nonepithelial VDR signaling is unknown. Here, we showed that colonic epithelial VDR expression was substantially reduced in patients with Crohn’s disease or ulcerative colitis. Moreover, targeted expression of human VDR (hVDR) in intestinal epithelial cells (IECs) protected mice from developing colitis. In experimental colitis models induced by 2,4,6-trinitrobenzenesulfonic acid, dextran sulfate sodium, or CD4+CD45RBhi T cell transfer, transgenic mice expressing hVDR in IECs were highly resistant to colitis, as manifested by marked reductions in clinical colitis scores, colonic histological damage, and colonic inflammation compared with WT mice. Reconstitution of Vdr-deficient IECs with the hVDR transgene completely rescued Vdr-null mice from severe colitis and death, even though the mice still maintained a hyperresponsive Vdr-deficient immune system. Mechanistically, VDR signaling attenuated PUMA induction in IECs by blocking NF-κB activation, leading to a reduction in IEC apoptosis. Together, these results demonstrate that gut epithelial VDR signaling inhibits colitis by protecting the mucosal epithelial barrier, and this anticolitic activity is independent of nonepithelial immune VDR actions. PMID:23945234

  6. Age-Associated Increase in BMP Signaling inhibits Hippocampal Neurogenesis

    PubMed Central

    Yousef, Hanadie; Morgenthaler, Adam; Schlesinger, Christina; Bugaj, Lukasz; Conboy, Irina M.; Schaffer, David V.

    2016-01-01

    Hippocampal neurogenesis, the product of resident neural stem cell proliferation and differentiation, persists into adulthood but decreases with organismal aging, which may contribute to the age-related decline in cognitive function. The mechanisms that underlie this decrease in neurogenesis are not well understood, though evidence in general indicates that extrinsic changes in an aged stem cell niche can contribute to functional decline in old stem cells. Bone Morphogenetic Protein (BMP) family members are intercellular signaling proteins that regulate stem and progenitor cell quiescence, proliferation, and differentiation in various tissues and are likewise critical regulators of neurogenesis in young adults. Here, we establish that BMP signaling increases significantly in old murine hippocampi and inhibits neural progenitor cell proliferation. Furthermore, direct in vivo attenuation of BMP signaling via genetic and transgenic perturbations in aged mice led to elevated neural stem cell proliferation, and subsequent neurogenesis, in old hippocampi. Such advances in our understanding of mechanisms underlying decreased hippocampal neurogenesis with age may offer targets for the treatment of age-related cognitive decline. PMID:25538007

  7. Age-Associated Increase in BMP Signaling Inhibits Hippocampal Neurogenesis.

    PubMed

    Yousef, Hanadie; Morgenthaler, Adam; Schlesinger, Christina; Bugaj, Lukasz; Conboy, Irina M; Schaffer, David V

    2015-05-01

    Hippocampal neurogenesis, the product of resident neural stem cell proliferation and differentiation, persists into adulthood but decreases with organismal aging, which may contribute to the age-related decline in cognitive function. The mechanisms that underlie this decrease in neurogenesis are not well understood, although evidence in general indicates that extrinsic changes in an aged stem cell niche can contribute to functional decline in old stem cells. Bone morphogenetic protein (BMP) family members are intercellular signaling proteins that regulate stem and progenitor cell quiescence, proliferation, and differentiation in various tissues and are likewise critical regulators of neurogenesis in young adults. Here, we establish that BMP signaling increases significantly in old murine hippocampi and inhibits neural progenitor cell proliferation. Furthermore, direct in vivo attenuation of BMP signaling via genetic and transgenic perturbations in aged mice led to elevated neural stem cell proliferation, and subsequent neurogenesis, in old hippocampi. Such advances in our understanding of mechanisms underlying decreased hippocampal neurogenesis with age may offer targets for the treatment of age-related cognitive decline. PMID:25538007

  8. Design, synthesis and biological evaluation of novel EGFR/HER2 dual inhibitors bearing a oxazolo[4,5-g]quinazolin-2(1H)-one scaffold.

    PubMed

    Yin, Siyuan; Tang, Chunming; Wang, Bin; Zhang, Ying; Zhou, Liliang; Xue, Lingjing; Zhang, Can

    2016-09-14

    For the purpose of developing novel EGFR/HER2 tyrosine kinases inhibitors with high inhibition activity and low toxicity, two novel series of oxazolo[4,5-g]quinazolin-2(1H)-one derivatives as EGFR/HER2 dual inhibitors introducing two electrophiles 2-(2-bromoacetyl)ethyl and 2-(2-chloroacetoxy)ethyl group as side-chain at 1-position respectively and evaluated their EGFR and HER2 inhibition activity and toxicity comparing with Lapatinib. All these compounds were evaluated by EGFR and HER2 kinase inhibition and two anti-proliferation assays in vitro. Most of the designed compounds exhibited moderate to high inhibition activity against EGFR and HER2. Especially, compounds 11o, 11p, 12e and 12f presented high inhibition against EGFR and HER2. Furthermore, compounds 11p and 12f also had well exhibition to excellent anti-proliferation activity against human lung adenocarcinoma cell line (A549) and human breast cancer cell line (SK-Br3), and 12f also exhibited the lowest toxicity against human embryonic lung fibroblast cell line (HELF) cell. Finally, compound 12f presented remarkably higher inhibition efficacy towards tumour growth than Lapatinib in a mouse lewis lung cancer (LLC) xenograft model. PMID:27187856

  9. Notch-EGFR/HER2 Bidirectional Crosstalk in Breast Cancer

    PubMed Central

    Baker, Andrew T.; Zlobin, Andrei; Osipo, Clodia

    2014-01-01

    The Notch pathway is a well-established mediator of cell–cell communication that plays a critical role in stem cell survival, self-renewal, cell fate decisions, tumorigenesis, invasion, metastasis, and drug resistance in a variety of cancers. An interesting form of crosstalk exists between the Notch receptor and the Epidermal Growth Factor Receptor Tyrosine Kinase family, which consists of HER-1, -2, -3, and -4. Overexpression of HER and/or Notch occurs in several human cancers including brain, lung, breast, ovary, and skin making them potent oncogenes capable of advancing malignant disease. Continued assessment of interplay between these two critical signaling networks uncovers new insight into mechanisms used by HER-driven cancer cells to exploit Notch as a compensatory pathway. The compensatory Notch pathway maintains HER-induced downstream signals transmitted to pathways such as Mitogen Activated Protein Kinase and Phosphatidylinositol 3-Kinase (PI3K), thereby allowing cancer cells to survive molecular targeted therapies, undergo epithelial to mesenchymal transitioning, and increase cellular invasion. Uncovering the critical crosstalk between the HER and Notch pathways can lead to improved screening for the expression of these oncogenes enabling patients to optimize their personal treatment options and predict potential treatment resistance. This review will focus on the current state of crosstalk between the HER and Notch receptors and the effectiveness of current therapies targeting HER-driven cancers. PMID:25566499

  10. Central nervous system relapse in patients with untreated HER2-positive esophageal or gastroesophageal junction adenocarcinoma.

    PubMed

    Yoon, Harry H; Lewis, Mark A; Foster, Nathan R; Sukov, William R; Khan, Maliha; Sattler, Christopher A; Wiktor, Anne E; Wu, Tsung-Teh; Jenkins, Robert B; Sinicrope, Frank A

    2016-10-01

    Although HER2-positive breast cancers demonstrate a propensity for central nervous system (CNS) metastasis, it is unknown whether other HER2-positive tumors, including adenocarcinomas of the esophagus/gastroesophageal junction (EAC), share this characteristic. Insight into this association may inform the development of HER2-targeted therapies that penetrate the blood-brain barrier. We examined HER2 overexpression and gene amplification in 708 patients with EAC who underwent curative-intent surgery during a time period (1980-1997) when no patient received HER2-targeted therapy. We identified patients whose site of first cancer recurrence was CNS and those who had a CNS relapse at any time. After a median follow-up of 61.2 months, 3.4% (24/708) of patients developed CNS relapse (all involved the brain). Patients with HER2-positive (vs -negative) primary tumors showed a higher 5-year cumulative incidence of CNS relapse as first recurrence (5.8% vs. 1.2%; p = 0.0058) and at any time (8.3% vs. 2.4%; p = 0.0062). In a multivariable model that included covariates previously associated with HER2 or with CNS relapse in breast cancer, HER2 positivity was the only variable that was statistically significantly associated with shorter time to CNS relapse as first recurrence (p = 0.0026) or at any time (hazard ratio 4.3 [95% confidence interval 1.8 to 10.3]; p = 0.001). These are the first data in a non-breast cancer to demonstrate an association between HER2 positivity and higher CNS relapse risk after surgery, and suggest that HER2-positive EACs have a predilection for CNS metastases. PMID:27198655

  11. Duration of trastuzumab in patients with HER2-positive metastatic breast cancer in prolonged remission

    PubMed Central

    Haq, R.; Gulasingam, P.

    2016-01-01

    Background Outcomes in metastatic breast cancer (mbc) positive for her2 (human epidermal growth factor receptor 2) are generally unfavourable. Trastuzumab has revolutionized the prognosis of her2-positive mbc. Some her2-positive mbc patients go into prolonged remission, and a few patients remain in remission even after discontinuation of trastuzumab, suggesting the possibility of a cure. In our practice, 4 her2-positive mbc patients treated with chemotherapy and trastuzumab have remained in remission on maintenance therapy for 5 years or more. Of those 4 patients, 2 have continued in remission after discontinuation of trastuzumab for more than 1 year. The objective of the present paper was therefore to address the duration of trastuzumab therapy in her2-positive mbc patients in prolonged remission. Methods We conducted a literature review of the duration of trastuzumab in her2-positive mbc patients in remission. We also conducted an online survey of oncologists in Ontario to determine their treatment practices in her2-positive mbc patients. Results The literature search found no specific evidence about the optimal duration of trastuzumab maintenance therapy in her2-positive mbc in prolonged remission. However, retrospective studies suggest predictive markers of good prognosis in patients in complete remission taking maintenance trastuzumab. Identifying those markers could lead to more personalized treatment. Our survey of oncologists about their treatment practices in her2-positive mbc patients revealed that 82.93% of respondents (n = 34) follow the currently available guidelines. Conclusions With the emergence of patients in prolonged remission, duration of trastuzumab in her2-positive mbc has become an important and relevant clinical question worldwide. Collaborative efforts are needed for the further study of this topic. PMID:27122973

  12. HYPOTHESIZED ROLE OF PREGNANCY HORMONES ON HER2+ BREAST TUMOR DEVELOPMENT

    PubMed Central

    Cruz, Giovanna I.; Martínez, María Elena; Natarajan, Loki; Wertheim, Betsy C.; Gago-Dominguez, Manuela; Bondy, Melissa; Daneri-Navarro, Adrian; Meza-Montenegro, María Mercedes; Gutierrez-Millan, Luis Enrique; Brewster, Abenaa; Schedin, Pepper; Komenaka, Ian K.; Castelao, J. Esteban; Carracedo, Angel; Redondo, Carmen M.; Thompson, Patricia A.

    2014-01-01

    Breast cancer incidence rates have declined among older but not younger women; the latter are more likely to be diagnosed with breast cancers carrying a poor prognosis. Epidemiological evidence supports an increase in breast cancer incidence following pregnancy with risk elevated as much as 10 years postpartum. We investigated the association between years since last full-term pregnancy at the time of diagnosis (≤10 or >10 years) and breast tumor subtype in a case series of premenopausal Hispanic women (n = 627). Participants were recruited in the United States, Mexico, and Spain. Cases with known estrogen receptor (ER), progesterone receptor (PR), and HER2 status, with one or more full-term pregnancies ≥1 year prior to diagnosis were eligible for this analysis. Cases were classified into three tumor subtypes according to hormone receptor (HR+ = ER+ and/or PR+; HR− = ER− and PR−) expression and HER2 status: HR+/HER2−, HER2+ (regardless of HR), and triple negative breast cancer (TNBC). Case-only odds ratios (ORs) and 95% confidence intervals (CIs) were calculated for HER2+ tumors in reference to HR+/HER2− tumors. Participants were pooled in a mixed-effects logistic regression model with years since pregnancy as a fixed effect and study site as a random effect. When compared to HR+/HER2− cases, women with HER2+ tumors were more likely be diagnosed in the postpartum period of ≤10 years (OR=1.68; 95% CI, 1.12–2.52). The effect was present across all source populations and independent of the HR status of the HER2+ tumor. Adjusting for age at diagnosis (≤45 or >45 years) did not materially alter our results (OR=1.78; 95% CI, 1.08–2.93). These findings support the novel hypothesis that factors associated with the postpartum breast, possibly hormonal, are involved in the development of HER2+ tumors. PMID:23135573

  13. Microfluidic processor allows rapid HER2 immunohistochemistry of breast carcinomas and significantly reduces ambiguous (2+) read-outs

    PubMed Central

    Ciftlik, Ata Tuna; Lehr, Hans-Anton; Gijs, Martin A. M.

    2013-01-01

    Biomarker analysis is playing an essential role in cancer diagnosis, prognosis, and prediction. Quantitative assessment of immunohistochemical biomarker expression on tumor tissues is of clinical relevance when deciding targeted treatments for cancer patients. Here, we report a microfluidic tissue processor that permits accurate quantification of the expression of biomarkers on tissue sections, enabled by the ultra-rapid and uniform fluidic exchange of the device. An important clinical biomarker for invasive breast cancer is human epidermal growth factor receptor 2 [(HER2), also known as neu], a transmembrane tyrosine kinase that connotes adverse prognostic information for the patients concerned and serves as a target for personalized treatment using the humanized antibody trastuzumab. Unfortunately, when using state-of-the-art methods, the intensity of an immunohistochemical signal is not proportional to the extent of biomarker expression, causing ambiguous outcomes. Using our device, we performed tests on 76 invasive breast carcinoma cases expressing various levels of HER2. We eliminated more than 90% of the ambiguous results (n = 27), correctly assigning cases to the amplification status as assessed by in situ hybridization controls, whereas the concordance for HER2-negative (n = 31) and -positive (n = 18) cases was 100%. Our results demonstrate the clinical potential of microfluidics for accurate biomarker expression analysis. We anticipate our technique will be a diagnostic tool that will provide better and more reliable data, onto which future treatment regimes can be based. PMID:23479638

  14. Melatonin Attenuates Her-2, p38 MAPK, p-AKT, and mTOR Levels in Ovarian Carcinoma of Ethanol-Preferring Rats

    PubMed Central

    Ferreira, Grazielle M.; Martinez, Marcelo; Camargo, Isabel Cristina C.; Domeniconi, Raquel F.; Martinez, Francisco Eduardo; Chuffa, Luiz Gustavo A.

    2014-01-01

    Epidermal growth factor receptors 2 (Her-2) and 4 (Her-4) are closely associated with ovarian cancer (OC) progression and metastasis, and a more complete understanding of these signaling pathways allow the development of new therapeutic strategies. Melatonin (Mel) is recognized as having several anticancer properties and has been reported to modulate Her-2 system in aggressive tumors. Here, we investigated OC and the role of Mel therapy on the Her-2- and Her-4-signaling pathway related to downstream molecules in an ethanol-preferring rat model. To induce OC, the left ovary was injected directly with a single dose of 100 µg 7,12-dimethylbenz(a)anthracene (DMBA) dissolved in 10 µL of sesame oil under the bursa. Right ovaries were used as sham-surgery controls. After developing OC, half of the animals received i.p. injections of Mel (200 µg/100 g b.w./day) for 60 days. While Mel therapy was unable to reduce Her-4 and phosphoinositide 3-kinase (PI3K) levels, it was able to suppress the OC-related increase in the levels of the Her-2, p38 mitogen-activated protein kinases (p38 MAPK), protein kinase B (phospho-AKT), and mammalian target of rapamycin (mTOR). In addition, Mel significantly attenuated the expression of Her-2, p38 MAPK, and p-AKT, which are involved in OC signaling during ethanol intake. Collectively, our results suggest that Mel attenuates the Her-2-signaling pathway in OC of ethanol-preferring rats, providing an effective contribution for further development of adjuvant therapies. PMID:25368672

  15. A phase 1 study of a heterologous prime-boost vaccination involving a truncated HER2 sequence in patients with HER2-expressing breast cancer

    PubMed Central

    Kim, Sung-Bae; Ahn, Jin-Hee; Kim, Jeongeun; Jung, Kyung Hae

    2015-01-01

    A phase 1 clinical trial was conducted to assess the safety, tolerability, and preliminary efficacy of a heterologous prime-boost strategy involving plasmid DNA (pHM-GM-CSF, expressing truncated human epidermal growth factor receptor 2 (HER2) and granulocyte macrophage colony-stimulation factor (GM-CSF) as a bicistronic message) and an adenoviral vector (Ad-HM, containing the same modified HER2 sequence only), in patients with stage III–IV metastatic breast cancer expressing HER2. Nine eligible subjects were divided into three cohorts based on the dosages (2, 4, and 8 mg/patient/visit) of pHM-GM-CSF used as the primer, which was intramuscularly injected three times at weeks 0, 2, and 4. It was followed by a single injection of Ad-HM (3 × 109 virus particles), used as a booster, at week 6. During the 6-month follow-up period, adverse events (AEs), pharmacokinetics and pharmacodynamics, and HER2-specific cellular and humoral immune responses were evaluated. Seven cases of minor grade 1 toxicities in four of nine subjects and no serious drug-related AEs were reported. HER2-specific cell-mediated or humoral immunity was produced in all (100%) or three subjects (33%), respectively. One subject showed a partial response, and seven subjects had stable diseases. However, there were no differences in clinical tumor response and HER2-specific immune responses among the cohorts. These results showed that intramuscular injections of pHM-GM-CSF and Ad-HM were well tolerated and safe. PMID:26445724

  16. Honokiol inhibits melanoma stem cells by targeting notch signaling.

    PubMed

    Kaushik, Gaurav; Venugopal, Anand; Ramamoorthy, Prabhu; Standing, David; Subramaniam, Dharmalingam; Umar, Shahid; Jensen, Roy A; Anant, Shrikant; Mammen, Joshua M V

    2015-12-01

    Melanoma is an aggressive disease with limited therapeutic options. Here, we determined the effects of honokiol (HNK), a biphenolic natural compound on melanoma cells and stemness. HNK significantly inhibited melanoma cell proliferation, viability, clonogenicity and induced autophagy. In addition, HNK significantly inhibited melanosphere formation in a dose dependent manner. Western blot analyses also demonstrated reduction in stem cell markers CD271, CD166, Jarid1b, and ABCB5. We next examined the effect of HNK on Notch signaling, a pathway involved in stem cell self-renewal. Four different Notch receptors exist in cells, which when cleaved by a series of enzymatic reactions catalyzed by Tumor Necrosis Factor-α-Converting Enzyme (TACE) and γ-secretase protein complex, results in the release of the Notch intracellular domain (NICD), which then translocates to the nucleus and induces target gene expression. Western blot analyses demonstrated that in HNK treated cells there is a significant reduction in the expression of cleaved Notch-2. In addition, there was a reduction in the expression of downstream target proteins, Hes-1 and cyclin D1. Moreover, HNK treatment suppressed the expression of TACE and γ-secretase complex proteins in melanoma cells. To confirm that suppression of Notch-2 activation is critical for HNK activity, we overexpressed NICD1, NICD2, and performed HNK treatment. NICD2, but not NICD1, partially restored the expression of Hes-1 and cyclin D1, and increased melanosphere formation. Taken together, these data suggest that HNK is a potent inhibitor of melanoma cells, in part, through the targeting of melanoma stem cells by suppressing Notch-2 signaling. PMID:25491779

  17. Xanthohumol Inhibits Notch Signaling and Induces Apoptosis in Hepatocellular Carcinoma

    PubMed Central

    Kunnimalaiyaan, Selvi; Gamblin, T. Clark; Kunnimalaiyaan, Muthusamy

    2015-01-01

    Despite improvement in therapeutic strategies, median survival in advanced hepatocellular carcinoma (HCC) remains less than one year. Therefore, molecularly targeted compounds with less toxic profiles are needed. Xanthohumol (XN), a prenylated chalcone has been shown to have anti-proliferative effects in various cancers types in vitro. XN treatment in healthy mice and humans yielded favorable pharmacokinetics and bioavailability. Therefore, we determined to study the effects of XN and understand the mechanism of its action in HCC. The effects of XN on a panel of HCC cell lines were assessed for cell viability, colony forming ability, and cellular proliferation. Cell lysates were analyzed for pro-apoptotic (c-PARP and cleaved caspase-3) and anti-apoptotic markers (survivin, cyclin D1, and Mcl-1). XN concentrations of 5μM and above significantly reduced the cell viability, colony forming ability and also confluency of all four HCC cell lines studied. Furthermore, growth suppression due to apoptosis was evidenced by increased expression of pro-apoptotic and reduced expression of anti-apoptotic proteins. Importantly, XN treatment inhibited the Notch signaling pathway as evidenced by the decrease in the expression of Notch1 and HES-1 proteins. Ectopic expression of Notch1 in HCC cells reverses the anti-proliferative effect of XN as evidenced by reduced growth suppression compared to control. Taken together these results suggested that XN mediated growth suppression is appeared to be mediated by the inhibition of the Notch signaling pathway. Therefore, our findings warrants further studies on XN as a potential agent for the treatment for HCC. PMID:26011160

  18. Pharmacologic inhibition of JAK-STAT signaling promotes hair growth

    PubMed Central

    Harel, Sivan; Higgins, Claire A.; Cerise, Jane E.; Dai, Zhenpeng; Chen, James C.; Clynes, Raphael; Christiano, Angela M.

    2015-01-01

    Several forms of hair loss in humans are characterized by the inability of hair follicles to enter the growth phase (anagen) of the hair cycle after being arrested in the resting phase (telogen). Current pharmacologic therapies have been largely unsuccessful in targeting pathways that can be selectively modulated to induce entry into anagen. We show that topical treatment of mouse and human skin with small-molecule inhibitors of the Janus kinase (JAK)–signal transducer and activator of transcription (STAT) pathway results in rapid onset of anagen and subsequent hair growth. We show that JAK inhibition regulates the activation of key hair follicle populations such as the hair germ and improves the inductivity of cultured human dermal papilla cells by controlling a molecular signature enriched in intact, fully inductive dermal papillae. Our findings open new avenues for exploration of JAK-STAT inhibition for promotion of hair growth and highlight the role of this pathway in regulating the activation of hair follicle stem cells. PMID:26601320

  19. Autophagy Inhibition Dysregulates TBK1 Signaling and Promotes Pancreatic Inflammation.

    PubMed

    Yang, Shenghong; Imamura, Yu; Jenkins, Russell W; Cañadas, Israel; Kitajima, Shunsuke; Aref, Amir; Brannon, Arthur; Oki, Eiji; Castoreno, Adam; Zhu, Zehua; Thai, Tran; Reibel, Jacob; Qian, Zhirong; Ogino, Shuji; Wong, Kwok K; Baba, Hideo; Kimmelman, Alec C; Pasca Di Magliano, Marina; Barbie, David A

    2016-06-01

    Autophagy promotes tumor progression downstream of oncogenic KRAS, yet also restrains inflammation and dysplasia through mechanisms that remain incompletely characterized. Understanding the basis of this paradox has important implications for the optimal targeting of autophagy in cancer. Using a mouse model of cerulein-induced pancreatitis, we found that loss of autophagy by deletion of Atg5 enhanced activation of the IκB kinase (IKK)-related kinase TBK1 in vivo, associated with increased neutrophil and T-cell infiltration and PD-L1 upregulation. Consistent with this observation, pharmacologic or genetic inhibition of autophagy in pancreatic ductal adenocarcinoma cells, including suppression of the autophagy receptors NDP52 or p62, prolonged TBK1 activation and increased expression of CCL5, IL6, and several other T-cell and neutrophil chemotactic cytokines in vitro Defective autophagy also promoted PD-L1 upregulation, which is particularly pronounced downstream of IFNγ signaling and involves JAK pathway activation. Treatment with the TBK1/IKKε/JAK inhibitor CYT387 (also known as momelotinib) not only inhibits autophagy, but also suppresses this feedback inflammation and reduces PD-L1 expression, limiting KRAS-driven pancreatic dysplasia. These findings could contribute to the dual role of autophagy in oncogenesis and have important consequences for its therapeutic targeting. Cancer Immunol Res; 4(6); 520-30. ©2016 AACR. PMID:27068336

  20. Pharmacologic inhibition of JAK-STAT signaling promotes hair growth.

    PubMed

    Harel, Sivan; Higgins, Claire A; Cerise, Jane E; Dai, Zhenpeng; Chen, James C; Clynes, Raphael; Christiano, Angela M

    2015-10-01

    Several forms of hair loss in humans are characterized by the inability of hair follicles to enter the growth phase (anagen) of the hair cycle after being arrested in the resting phase (telogen). Current pharmacologic therapies have been largely unsuccessful in targeting pathways that can be selectively modulated to induce entry into anagen. We show that topical treatment of mouse and human skin with small-molecule inhibitors of the Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathway results in rapid onset of anagen and subsequent hair growth. We show that JAK inhibition regulates the activation of key hair follicle populations such as the hair germ and improves the inductivity of cultured human dermal papilla cells by controlling a molecular signature enriched in intact, fully inductive dermal papillae. Our findings open new avenues for exploration of JAK-STAT inhibition for promotion of hair growth and highlight the role of this pathway in regulating the activation of hair follicle stem cells. PMID:26601320

  1. Antitumor Activity of TAK-285, an Investigational, Non-Pgp Substrate HER2/EGFR Kinase Inhibitor, in Cultured Tumor Cells, Mouse and Rat Xenograft Tumors, and in an HER2-Positive Brain Metastasis Model.

    PubMed

    Nakayama, Akiko; Takagi, Shinji; Yusa, Tadashi; Yaguchi, Masahiro; Hayashi, Akira; Tamura, Toshiya; Kawakita, Youichi; Ishikawa, Tomoyasu; Ohta, Yoshikazu

    2013-01-01

    Breast cancer therapy has improved following the development of drugs with specific molecular targets, exemplified by inhibitors of human epidermal growth factor receptor-2 (HER2) or epidermal growth factor receptor (EGFR) such as trastuzumab and lapatinib. However, these drugs have little effect on brain metastasis due to the combined effects of poor penetration of the blood-brain barrier and their removal from the central nervous system (CNS) by the p-glycoprotein (Pgp) drug efflux pump. We investigated the effects of TAK-285, a novel, investigational, dual EGFR/HER2 inhibitor that has been shown to penetrate the CNS and has comparable inhibitory efficacy to lapatinib which is a known Pgp substrate. Tested against a panel of 96 kinases, TAK-285 showed specificity for inhibition of HER family kinases. Unlike lapatinib, TAK-285 is not a substrate for Pgp efflux. In mouse and rat xenograft tumor models, TAK-285 showed antitumor activity against cancers that expressed HER2 or EGFR. TAK-285 was as effective as lapatinib in antitumor activity in a mouse subcutaneous BT-474 breast cancer xenograft model. TAK-285 was examined in a model of breast cancer brain metastasis using direct intracranial injection of BT-474-derived luciferase-expressing cells and showed greater inhibition of brain tumor growth compared to animals treated with lapatinib. Our studies suggest that investigational drugs such as TAK-285 that have strong antitumor activity and are not Pgp substrates may be useful in the development of agents with the potential to treat brain metastases. PMID:23983820

  2. Intratumoral Delivery of IL-21 Overcomes Anti-Her2/Neu Resistance through Shifting Tumor-Associated Macrophages from M2 to M1 Phenotype.

    PubMed

    Xu, Meng; Liu, Mingyue; Du, Xuexiang; Li, Sirui; Li, Hang; Li, Xiaozhu; Li, Ying; Wang, Yang; Qin, Zhihai; Fu, Yang-Xin; Wang, Shengdian

    2015-05-15

    Tumor resistance is a major hurdle to anti-Her2/neu Ab-based cancer therapy. Current strategies to overcome tumor resistance focus on tumor cell-intrinsic resistance. However, the extrinsic mechanisms, especially the tumor microenvironment, also play important roles in modulating the therapeutic response and resistance of the Ab. In this study, we demonstrate that tumor progression is highly associated with TAMs with immune-suppressive M2 phenotypes, and deletion of TAMs markedly enhanced the therapeutic effects of anti-Her2/neu Ab in a HER2/neu-dependent breast cancer cell TUBO model. Tumor local delivery of IL-21 can skew TAM polarization away from the M2 phenotype to a tumor-inhibiting M1 phenotype, which rapidly stimulates T cell responses against tumor and dramatically promotes the therapeutic effect of anti-Her2 Ab. Skewing of TAM polarization by IL-21 relies substantially on direct action of IL-21 on TAMs rather than stimulation of T and NK cells. Thus, our findings identify the abundant TAMs as a major extrinsic barrier for anti-Her2/neu Ab therapy and present a novel approach to combat this extrinsic resistance by tumor local delivery of IL-21 to skew TAM polarization. This study offers a therapeutic strategy to modulate the tumor microenvironment to overcome tumor-extrinsic resistance. PMID:25876763

  3. Targeted Therapies in HER2-Positive Breast Cancer – a Systematic Review

    PubMed Central

    Schramm, Amelie; De Gregorio, Nikolaus; Widschwendter, Peter; Fink, Visnja; Huober, Jens

    2015-01-01

    Summary About 20% of all breast cancer patients have a human epidermal growth factor receptor 2 (HER2)-positive breast tumor. This entity underwent an impressive change in prognosis, with notable improvement of progression-free survival and overall survival. Due to more aggressive tumors and no specific therapy, HER2 overexpression was historically seen as a negative prognostic marker, with worse prognosis and increased risk of recurrent disease. Trastuzumab, the first anti-HER2 antibody, revolutionized the systemic therapy options in HER2-positive breast cancer and initiated several targeted therapies and more personalized treatment strategies. Over the years, multiple HER2-targeting drugs stepped into clinical practice, for the curative as well as the metastatic situation. This review summarizes the targeted treatment options in HER2-positive breast cancer and their current impact in the clinical routine. Results of the most outstanding trials in HER2-targeted therapies and important ongoing trials are subsequently described for an up-to-date overview. PMID:26557822

  4. The case for HER2/neu as a therapeutic target for gynecologic malignancies.

    PubMed

    Goyne, Hannah E; Cannon, Martin J

    2012-08-01

    Evaluation of: Guzzo F, Bellone S, Buza N et al. HER2/neu as a potential target for immunotherapy in gynecological carcinosarcomas. Int. J. Gynecol. Pathol. 31, 211-221 (2012). Trastuzumab (Herceptin(®)) is a human monoclonal antibody that is US FDA-approved for the treatment of HER2/neu-overexpressing breast cancer and metastatic gastric cancer. HER2/neu expression has also been observed in other malignancies, notably in subsets of endometrial and ovarian cancers, raising the possibility that trastuzumab may be a viable treatment option in these settings. The current paper reveals that HER2/neu may also be expressed in gynecologic carcinosarcomas, which are rare but aggressive tumors with a high rate of resistance to chemotherapy. Cell lines derived from ovarian carcinosarcomas expressed HER2/neu and were sensitive to trastuzumab ADCC. By contrast, cell lines derived from uterine carcinosarcomas were HER2/neu-negative and insensitive to trastuzumab ADCC. These observations indicate that at least a subset of gynecologic carcinosarcoma patients may benefit from trastuzumab treatment. However, trastuzumab monotherapy typically has relatively low response rates, which in part may be related to impaired NK cell function in patients with advanced disease. Accordingly, treatments that boost NK cell activity may improve response rates to trastuzumab treatment, not only for gynecologic carcinosarcomas, but also for other HER2/neu-positive malignancies. PMID:22947006

  5. Atomistic Insights into Regulatory Mechanisms of the HER2 Tyrosine Kinase Domain: A Molecular Dynamics Study

    PubMed Central

    Telesco, Shannon E.; Radhakrishnan, Ravi

    2009-01-01

    HER2 (ErbB2/Neu) is a receptor tyrosine kinase belonging to the epidermal growth factor receptor (EGFR)/ErbB family and is overexpressed in 20–30% of human breast cancers. Although several crystal structures of ErbB kinases have been solved, the precise mechanism of HER2 activation rema