Regulation of Deoxycholate Induction of CXCL8 by the Adenomatous Polyposis Coli Gene in Colorectal Cancer

PubMed Central

Rial, Nathaniel S; Lazennec, Gwendal; Prasad, Anil R; Krouse, Robert S; Lance, Peter; Gerner, Eugene W

2009-01-01

Elevated deoxycholic acid (DCA), mutations in the adenomatous polyposis coli (APC) gene and chronic inflammation are associated with increased risk of colorectal cancer (CRC). APC status was manipulated to determine whether DCA mediates inflammatory molecules in normal or initiated colonic mucosa. DCA increased steady state mRNA and protein levels of CXCL8 in cells which do not express wild type APC. Steady state CXCL8 mRNA and protein were suppressed when cells with conditional expression of wild type APC were exposed to DCA. Immunostaining did not detect CXCL8 in normal human colonic mucosa. CXCL8 was expressed in adenomatous polyps and adenocarcinomas. CXCL8 expression correlated with nuclear β-catenin localization in epithelial cells of adenomas, but was associated with endothelial cells and neutrophils in the adenocarcinomas. DCA-mediated CXCL8 promoter-reporter activity was elevated in a mutant APC background. Wild type APC suppressed this effect. Mutation of activator protein-1 (AP-1) or nuclear factor kappa B (NF-κB) sites suppressed the activation of the CXCL8 promoter-reporter by DCA. Chromatin immunoprecipitation (ChIP) revealed that AP-1 and NF-κB binding to the 5′-promoter of CXCL8 was induced by DCA. The β-catenin transcription factor was bound to the 5′-promoter of CXCL8 in the absence or presence of DCA. Phenotypic assays determined that DCA-mediated invasion was blocked by antibody directed against CXCL8 or wild type-APC. CXCL8 exposure lead to matrix metalloproteinase-2 (MMP-2) production and increased invasion on laminin coated filters. These data suggest that DCA-mediated CXCL8 occurs in initiated colonic epithelium and neutralizing CXCL8 could reduce the invasive potential of tumors. PMID:19173296

Modeling the Effect of APC Truncation on Destruction Complex Function in Colorectal Cancer Cells

PubMed Central

Barua, Dipak; Hlavacek, William S.

2013-01-01

In colorectal cancer cells, APC, a tumor suppressor protein, is commonly expressed in truncated form. Truncation of APC is believed to disrupt degradation of β—catenin, which is regulated by a multiprotein complex called the destruction complex. The destruction complex comprises APC, Axin, β—catenin, serine/threonine kinases, and other proteins. The kinases and , which are recruited by Axin, mediate phosphorylation of β—catenin, which initiates its ubiquitination and proteosomal degradation. The mechanism of regulation of β—catenin degradation by the destruction complex and the role of truncation of APC in colorectal cancer are not entirely understood. Through formulation and analysis of a rule-based computational model, we investigated the regulation of β—catenin phosphorylation and degradation by APC and the effect of APC truncation on function of the destruction complex. The model integrates available mechanistic knowledge about site-specific interactions and phosphorylation of destruction complex components and is consistent with an array of published data. We find that the phosphorylated truncated form of APC can outcompete Axin for binding to β—catenin, provided that Axin is limiting, and thereby sequester β—catenin away from Axin and the Axin-recruited kinases and . Full-length APC also competes with Axin for binding to β—catenin; however, full-length APC is able, through its SAMP repeats, which bind Axin and which are missing in truncated oncogenic forms of APC, to bring β—catenin into indirect association with Axin and Axin-recruited kinases. Because our model indicates that the positive effects of truncated APC on β—catenin levels depend on phosphorylation of APC, at the first 20-amino acid repeat, and because phosphorylation of this site is mediated by , we suggest that is a potential target for therapeutic intervention in colorectal cancer. Specific inhibition of is predicted to limit binding of β—catenin to truncated APC and thereby to reverse the effect of APC truncation. PMID:24086117

Adenomatous Polyposis Coli-Mediated Accumulation of Abasic DNA Lesions Lead to Cigarette Smoke Condensate-Induced Neoplastic Transformation of Normal Breast Epithelial Cells1

PubMed Central

Jaiswal, Aruna S; Panda, Harekrushna; Pampo, Christine A; Siemann, Dietmar W; Gairola, C Gary; Hromas, Robert; Narayan, Satya

2013-01-01

Adenomatous polyposis coli (APC) is a multifunctional protein having diverse cellular functions including cell migration, cell-cell adhesion, cell cycle control, chromosomal segregation, and apoptosis. Recently, we found a new role of APC in base excision repair (BER) and showed that it interacts with DNA polymerase β and 5′-flap endonuclease 1 and interferes in BER. Previously, we have also reported that cigarette smoke condensate (CSC) increases expression of APC and enhances the growth of normal human breast epithelial (MCF10A) cells in vitro. In the present study, using APC overexpression and knockdown systems, we have examined the molecular mechanisms by which CSC and its major component, Benzo[α]pyrene, enhances APC-mediated accumulation of abasic DNA lesions, which is cytotoxic and mutagenic in nature, leading to enhanced neoplastic transformation of MCF10A cells in an orthotopic xenograft model. PMID:23555190

Cytoprotective signaling by activated protein C requires protease-activated receptor-3 in podocytes

PubMed Central

Madhusudhan, Thati; Wang, Hongjie; Straub, Beate K.; Gröne, Elisabeth; Zhou, Qianxing; Shahzad, Khurrum; Müller-Krebs, Sandra; Schwenger, Vedat; Gerlitz, Bruce; Grinnell, Brian W.; Griffin, John H.; Reiser, Jochen; Gröne, Hermann-Josef; Esmon, Charles T.; Nawroth, Peter P.

2012-01-01

The cytoprotective effects of activated protein C (aPC) are well established. In contrast, the receptors and signaling mechanism through which aPC conveys cytoprotection in various cell types remain incompletely defined. Thus, within the renal glomeruli, aPC preserves endothelial cells via a protease-activated receptor-1 (PAR-1) and endothelial protein C receptor-dependent mechanism. Conversely, the signaling mechanism through which aPC protects podocytes remains unknown. While exploring the latter, we identified a novel aPC/PAR-dependent cytoprotective signaling mechanism. In podocytes, aPC inhibits apoptosis through proteolytic activation of PAR-3 independent of endothelial protein C receptor. PAR-3 is not signaling competent itself as it requires aPCinduced heterodimerization with PAR-2 (human podocytes) or PAR-1 (mouse podocytes). This cytoprotective signaling mechanism depends on caveolin-1 dephosphorylation. In vivo aPC protects against lipopolysaccharide-induced podocyte injury and proteinuria. Genetic deletion of PAR-3 impairs the nephroprotective effect of aPC, demonstrating the crucial role of PAR-3 for aPC-dependent podocyte protection. This novel, aPC-mediated interaction of PARs demonstrates the plasticity and cell-specificity of cytoprotective aPC signaling. The evidence of specific, dynamic signaling complexes underlying aPC-mediated cytoprotection may allow the design of cell type specific targeted therapies. PMID:22117049

WNT signaling controls expression of pro-apoptotic BOK and BAX in intestinal cancer

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

Zeilstra, Jurrit; Joosten, Sander P.J.; Wensveen, Felix M.

Research highlights: {yields} Intestinal adenomas initiated by aberrant activation of the WNT pathway displayed an increased sensitivity to apoptosis. {yields} Expression profiling of apoptosis-related genes in Apc{sup Min/+} mice revealed the differential expression of pro-apoptotic Bok and Bax. {yields} APC-mutant adenomatous crypts in FAP patients showed strongly increased BAX immunoreactivity. {yields} Blocking of {beta}-catenin/TCF-4-mediated signaling in colon cancer cells reduced the expression of BOK and BAX. -- Abstract: In a majority of cases, colorectal cancer is initiated by aberrant activation of the WNT signaling pathway. Mutation of the genes encoding the WNT signaling components adenomatous polyposis coli or {beta}-catenin causesmore » constitutively active {beta}-catenin/TCF-mediated transcription, driving the transformation of intestinal crypts to cancer precursor lesions, called dysplastic aberrant crypt foci. Deregulated apoptosis is a hallmark of adenomatous colon tissue. However, the contribution of WNT signaling to this process is not fully understood. We addressed this role by analyzing the rate of epithelial apoptosis in aberrant crypts and adenomas of the Apc{sup Min/+} mouse model. In comparison with normal crypts and adenomas, aberrant crypts displayed a dramatically increased rate of apoptotic cell death. Expression profiling of apoptosis-related genes along the crypt-villus axis and in Apc mutant adenomas revealed increased expression of two pro-apoptotic Bcl-2 family members in intestinal adenomas, Bok and Bax. Analysis of the colon of familial adenomatous polyposis (FAP) patients along the crypt-to-surface axis, and of dysplastic crypts, corroborated this expression pattern. Disruption of {beta}-catenin/TCF-4-mediated signaling in the colorectal cancer cell line Ls174T significantly decreased BOK and BAX expression, confirming WNT-dependent regulation in intestinal epithelial cells. Our results suggest a feedback mechanism by which uncontrolled epithelial cell proliferation in the stem cell compartment can be counterbalanced by an increased propensity to undergo cell death.« less

The SnRK2-APC/CTE regulatory module mediates the antagonistic action of gibberellic acid and abscisic acid pathways

PubMed Central

Lin, Qibing; Wu, Fuqing; Sheng, Peike; Zhang, Zhe; Zhang, Xin; Guo, Xiuping; Wang, Jiulin; Cheng, Zhijun; Wang, Jie; Wang, Haiyang; Wan, Jianmin

2015-01-01

Abscisic acid (ABA) and gibberellic acid (GA) antagonistically regulate many developmental processes and responses to biotic or abiotic stresses in higher plants. However, the molecular mechanism underlying this antagonism is still poorly understood. Here, we show that loss-of-function mutation in rice Tiller Enhancer (TE), an activator of the APC/CTE complex, causes hypersensitivity and hyposensitivity to ABA and GA, respectively. We find that TE physically interacts with ABA receptor OsPYL/RCARs and promotes their degradation by the proteasome. Genetic analysis also shows OsPYL/RCARs act downstream of TE in mediating ABA responses. Conversely, ABA inhibits APC/CTE activity by phosphorylating TE through activating the SNF1-related protein kinases (SnRK2s), which may interrupt the interaction between TE and OsPYL/RCARs and subsequently stabilize OsPYL/RCARs. In contrast, GA can reduce the level of SnRK2s and may promote APC/CTE-mediated degradation of OsPYL/RCARs. Thus, we propose that the SnRK2-APC/CTE regulatory module represents a regulatory hub underlying the antagonistic action of GA and ABA in plants. PMID:26272249

Modeling the Effect of APC Truncation on Destruction Complex Function in Colorectal Cancer Cells

DOE PAGES

Barua, Dipak; Hlavacek, William S.

2013-09-26

In colorectal cancer cells, APC, a tumor suppressor protein, is commonly expressed in truncated form. Truncation of APC is believed to disrupt degradation of β—catenin, which is regulated by a multiprotein complex called the destruction complex. The destruction complex comprises APC, Axin, β—catenin, serine/threonine kinases, and other proteins. The kinases CK1α and GSK–3β, which are recruited by Axin, mediate phosphorylation of β—catenin, which initiates its ubiquitination and proteosomal degradation. The mechanism of regulation of β—catenin degradation by the destruction complex and the role of truncation of APC in colorectal cancer are not entirely understood. Through formulation and analysis of amore » rule-based computational model, we investigated the regulation of β—catenin phosphorylation and degradation by APC and the effect of APC truncation on function of the destruction complex. The model integrates available mechanistic knowledge about site-specific interactions and phosphorylation of destruction complex components and is consistent with an array of published data. In this paper, we find that the phosphorylated truncated form of APC can outcompete Axin for binding to β—catenin, provided that Axin is limiting, and thereby sequester β—catenin away from Axin and the Axin-recruited kinases CK1α and GSK–3β. Full-length APC also competes with Axin for binding to β—catenin; however, full-length APC is able, through its SAMP repeats, which bind Axin and which are missing in truncated oncogenic forms of APC, to bring β—catenin into indirect association with Axin and Axin-recruited kinases. Because our model indicates that the positive effects of truncated APC on β—catenin levels depend on phosphorylation of APC, at the first 20-amino acid repeat, and because phosphorylation of this site is mediated by CK1ϵ, we suggest that CK1ϵ is a potential target for therapeutic intervention in colorectal cancer. Finally, specific inhibition of CK1ϵ is predicted to limit binding of β—catenin to truncated APC and thereby to reverse the effect of APC truncation.« less

Human APC sequesters beta-catenin even in the absence of GSK-3beta in a Drosophila model.

PubMed

Rao, P R; Makhijani, K; Shashidhara, L S

2008-04-10

There have been conflicting reports on the requirement of GSK-3beta-mediated phosphorylation of the tumor suppressor adenomatous polyposis coli (APC) vis-à-vis its ability to bind and degrade beta-catenin. Using a unique combination of loss of function for Shaggy/GSK-3beta and a gain of function for human APC in Drosophila, we show that misexpressed human APC (hAPC) can still sequester Armadillo/beta-catenin. In addition, human APC could suppress gain of Wnt/Wingless phenotypes associated with loss of Shaggy/GSK-3beta activity, suggesting that sequestered Armadillo/beta-catenin is non-functional. Based on these studies, we propose that binding per se of beta-catenin by APC does not require phosphorylation by GSK-3beta.

Adenomatous polyposis coli nucleates actin assembly to drive cell migration and microtubule-induced focal adhesion turnover

PubMed Central

Eskin, Julian A.; Jaiswal, Richa

2017-01-01

Cell motility depends on tight coordination between the microtubule (MT) and actin cytoskeletons, but the mechanisms underlying this MT–actin cross talk have remained poorly understood. Here, we show that the tumor suppressor protein adenomatous polyposis coli (APC), which is a known MT-associated protein, directly nucleates actin assembly to promote directed cell migration. By changing only two residues in APC, we generated a separation-of-function mutant, APC (m4), that abolishes actin nucleation activity without affecting MT interactions. Expression of full-length APC carrying the m4 mutation (APC (m4)) rescued cellular defects in MT organization, MT dynamics, and mitochondrial distribution caused by depletion of endogenous APC but failed to restore cell migration. Wild-type APC and APC (m4) localized to focal adhesions (FAs), and APC (m4) was defective in promoting actin assembly at FAs to facilitate MT-induced FA turnover. These results provide the first direct evidence for APC-mediated actin assembly in vivo and establish a role for APC in coordinating MTs and actin at FAs to direct cell migration. PMID:28663347

APC binds the Miro/Milton motor complex to stimulate transport of mitochondria to the plasma membrane

PubMed Central

Mills, Kate M.; Brocardo, Mariana G.; Henderson, Beric R.

2016-01-01

Mutations in adenomatous polyposis coli (APC) disrupt regulation of Wnt signaling, mitosis, and the cytoskeleton. We describe a new role for APC in the transport of mitochondria. Silencing of wild-type APC by small interfering RNA caused mitochondria to redistribute from the cell periphery to the perinuclear region. We identified novel APC interactions with the mitochondrial kinesin-motor complex Miro/Milton that were mediated by the APC C-terminus. Truncating mutations in APC abolished its ability to bind Miro/Milton and reduced formation of the Miro/Milton complex, correlating with disrupted mitochondrial distribution in colorectal cancer cells that could be recovered by reconstitution of wild-type APC. Using proximity ligation assays, we identified endogenous APC-Miro/Milton complexes at mitochondria, and live-cell imaging showed that loss of APC slowed the frequency of anterograde mitochondrial transport to the membrane. We propose that APC helps drive mitochondria to the membrane to supply energy for cellular processes such as directed cell migration, a process disrupted by cancer mutations. PMID:26658612

Structure of an APC3–APC16 Complex: Insights into Assembly of the Anaphase-Promoting Complex/Cyclosome

DOE PAGES

Yamaguchi, Masaya; Yu, Shanshan; Qiao, Renping; ...

2014-12-06

The anaphase-promoting complex/cyclosome (APC/C) is a massive E3 ligase that controls mitosis by catalyzing ubiquitination of key cell cycle regulatory proteins. The APC/C assembly contains two subcomplexes: the “Platform” centers around a cullin-RING-like E3 ligase catalytic core; the “Arc Lamp” is a hub that mediates transient association with regulators and ubiquitination substrates. The Arc Lamp contains the small subunits APC16, CDC26, and APC13, and tetratricopeptide repeat (TPR) proteins (APC7, APC3, APC6, and APC8) that homodimerize and stack with quasi-2-fold symmetry. Within the APC/C complex, APC3 serves as center for regulation. APC3's TPR motifs recruit substrate-binding coactivators, CDC20 and CDH1, viamore » their C-terminal conserved Ile-Arg (IR) tail sequences. Human APC3 also binds APC16 and APC7 and contains a > 200-residue loop that is heavily phosphorylated during mitosis, although the basis for APC3 interactions and whether loop phosphorylation is required for ubiquitination are unclear. Here, we map the basis for human APC3 assembly with APC16 and APC7, report crystal structures of APC3Δloop alone and in complex with the C-terminal domain of APC16, and test roles of APC3's loop and IR tail binding surfaces in APC/C-catalyzed ubiquitination. The structures show how one APC16 binds asymmetrically to the symmetric APC3 dimer and, together with biochemistry and prior data, explain how APC16 recruits APC7 to APC3, show how APC3's C-terminal domain is rearranged in the full APC/C assembly, and visualize residues in the IR tail binding cleft important for coactivator-dependent ubiquitination. Overall, the results provide insights into assembly, regulation, and interactions of TPR proteins and the APC/C.« less

The zinc-binding region (ZBR) fragment of Emi2 can inhibit APC/C by targeting its association with the coactivator Cdc20 and UBE2C-mediated ubiquitylation

PubMed Central

Shoji, Shisako; Muto, Yutaka; Ikeda, Mariko; He, Fahu; Tsuda, Kengo; Ohsawa, Noboru; Akasaka, Ryogo; Terada, Takaho; Wakiyama, Motoaki; Shirouzu, Mikako; Yokoyama, Shigeyuki

2014-01-01

Anaphase-promoting complex or cyclosome (APC/C) is a multisubunit ubiquitin ligase E3 that targets cell-cycle regulators. Cdc20 is required for full activation of APC/C in M phase, and mediates substrate recognition. In vertebrates, Emi2/Erp1/FBXO43 inhibits APC/C-Cdc20, and functions as a cytostatic factor that causes long-term M phase arrest of mature oocytes. In this study, we found that a fragment corresponding to the zinc-binding region (ZBR) domain of Emi2 inhibits cell-cycle progression, and impairs the association of Cdc20 with the APC/C core complex in HEK293T cells. Furthermore, we revealed that the ZBR fragment of Emi2 inhibits in vitro ubiquitin chain elongation catalyzed by the APC/C cullin-RING ligase module, the ANAPC2–ANAPC11 subcomplex, in combination with the ubiquitin chain-initiating E2, E2C/UBE2C/UbcH10. Structural analyses revealed that the Emi2 ZBR domain uses different faces for the two mechanisms. Thus, the double-faced ZBR domain of Emi2 antagonizes the APC/C function by inhibiting both the binding with the coactivator Cdc20 and ubiquitylation mediated by the cullin-RING ligase module and E2C. In addition, the tail region between the ZBR domain and the C-terminal RL residues [the post-ZBR (PZ) region] interacts with the cullin subunit, ANAPC2. In the case of the ZBR fragment of the somatic paralogue of Emi2, Emi1/FBXO5, these inhibitory activities against cell division and ubiquitylation were not observed. Finally, we identified two sets of key residues in the Emi2 ZBR domain that selectively exert each of the dual Emi2-specific modes of APC/C inhibition, by their mutation in the Emi2 ZBR domain and their transplantation into the Emi1 ZBR domain. PMID:25161877

APC/β-catenin-rich complexes at membrane protrusions regulate mammary tumor cell migration and mesenchymal morphology

PubMed Central

2013-01-01

Background The APC tumor suppressor is mutated or downregulated in many tumor types, and is prominently localized to punctate clusters at protrusion tips in migratory cells, such as in astrocytes where it has been implicated in directed cell motility. Although APC loss is considered an initiating event in colorectal cancer, for example, it is less clear what role APC plays in tumor cell motility and whether loss of APC might be an important promoter of tumor progression in addition to initiation. Methods The localization of APC and β-catenin was analyzed in multiple cell lines, including non-transformed epithelial lines treated with a proteasome inhibitor or TGFβ to induce an epithelial-to-mesenchymal transition (EMT), as well as several breast cancer lines, by immunofluorescence. APC expression was knocked down in 4T07 mammary tumor cells using lentiviral-mediated delivery of APC-specific short-hairpin (sh) RNAs, and assessed using quantitative (q) reverse-transcriptase (RT)-PCR and western blotting. Tumor cell motility was analyzed by performing wound-filling assays, and morphology via immunofluorescence (IF) and phase-contrast microscopy. Additionally, proliferation was measured using BrdU incorporation, and TCF reporter assays were performed to determine β-catenin/TCF-mediated transcriptional activity. Results APC/β-catenin-rich complexes were observed at protrusion ends of migratory epithelial cells treated with a proteasome inhibitor or when EMT has been induced and in tumor cells with a mesenchymal, spindle-like morphology. 4T07 tumor cells with reduced APC levels were significantly less motile and had a more rounded morphology; yet, they did not differ significantly in proliferation or β-catenin/TCF transcriptional activity. Furthermore, we found that APC/β-catenin-rich complexes at protrusion ends were dependent upon an intact microtubule cytoskeleton. Conclusions These findings indicate that membrane protrusions with APC/β-catenin-containing puncta control the migratory potential and mesenchymal morphology of mammary tumor cells and suggest that APC loss during later stages of tumor progression might impact tumor cell dissemination or colonization. PMID:23302090

Endothelial protein C receptor is overexpressed in rheumatoid arthritic (RA) synovium and mediates the anti‐inflammatory effects of activated protein C in RA monocytes

PubMed Central

Xue, Meilang; March, Lyn; Sambrook, Philip N; Fukudome, Kenji; Jackson, Christopher J

2007-01-01

Objectives (1) To investigate whether inflammatory synovial tissues from patients with rheumatoid arthritis (RA) express endothelial protein C receptor (EPCR) and (2) to determine the major cell type(s) that EPCR is associated with and whether EPCR functions to mediate the effects of activated protein C (APC) on these cells. Methods EPCR, CD68 and PC/APC in synovial tissues were detected by immunostaining and in situ PCR. Monocytes were isolated from peripheral blood of patients with RA and treated with APC, lipopolysaccharide (LPS), and/or EPCR blocking antibody RCR252. Cells and supernatants were collected for RT‐PCR, western blotting, enzyme‐linked immuosorbent assay and chemotaxis assay. Results: EPCR was expressed by both OA and RA synovial tissues but was markedly increased in RA synovium. EPCR was colocalised with PC/APC mostly on CD68 positive cells in synovium. In RA monocytes, APC upregulated EPCR expression and reduced monocyte chemoattractant protein‐1‐induced chemotaxis of monocytes by approximately 50%. APC also completely suppressed LPS‐stimulated NF‐κB activation and attenuated TNF‐α protein by more than 40% in RA monocytes. The inhibitory effects of APC were reversed by RCR252, indicating that EPCR is required. Conclusions Our results demonstrate for the first time that EPCR is expressed by synovial tissues, particularly in RA, where it co‐localises with PC/APC on monocytes/macrophages. In addition, APC inhibits the migration and activation of RA monocytes via EPCR. These inhibitory effects on RA monocytes suggest that PC pathway may have a beneficial therapeutic effect in RA. PMID:17491095

Antigen presenting cell-mediated expansion of human umbilical cord blood yields log-scale expansion of natural killer cells with anti-myeloma activity.

PubMed

Shah, Nina; Martin-Antonio, Beatriz; Yang, Hong; Ku, Stephanie; Lee, Dean A; Cooper, Laurence J N; Decker, William K; Li, Sufang; Robinson, Simon N; Sekine, Takuya; Parmar, Simrit; Gribben, John; Wang, Michael; Rezvani, Katy; Yvon, Eric; Najjar, Amer; Burks, Jared; Kaur, Indreshpal; Champlin, Richard E; Bollard, Catherine M; Shpall, Elizabeth J

2013-01-01

Natural killer (NK) cells are important mediators of anti-tumor immunity and are active against several hematologic malignancies, including multiple myeloma (MM). Umbilical cord blood (CB) is a promising source of allogeneic NK cells but large scale ex vivo expansion is required for generation of clinically relevant CB-derived NK (CB-NK) cell doses. Here we describe a novel strategy for expanding NK cells from cryopreserved CB units using artificial antigen presenting feeder cells (aAPC) in a gas permeable culture system. After 14 days, mean fold expansion of CB-NK cells was 1848-fold from fresh and 2389-fold from cryopreserved CB with >95% purity for NK cells (CD56(+)/CD3(-)) and less than 1% CD3(+) cells. Though surface expression of some cytotoxicity receptors was decreased, aAPC-expanded CB-NK cells exhibited a phenotype similar to CB-NK cells expanded with IL-2 alone with respect to various inhibitory receptors, NKG2C and CD94 and maintained strong expression of transcription factors Eomesodermin and T-bet. Furthermore, CB-NK cells formed functional immune synapses with and demonstrated cytotoxicity against various MM targets. Finally, aAPC-expanded CB-NK cells showed significant in vivo activity against MM in a xenogenic mouse model. Our findings introduce a clinically applicable strategy for the generation of highly functional CB-NK cells which can be used to eradicate MM.

β-Catenin destruction complex-independent regulation of Hippo–YAP signaling by APC in intestinal tumorigenesis

PubMed Central

Cai, Jing; Maitra, Anirban; Anders, Robert A.; Taketo, Makoto M.; Pan, Duojia

2015-01-01

Mutations in Adenomatous polyposis coli (APC) underlie familial adenomatous polyposis (FAP), an inherited cancer syndrome characterized by the widespread development of colorectal polyps. APC is best known as a scaffold protein in the β-catenin destruction complex, whose activity is antagonized by canonical Wnt signaling. Whether other effector pathways mediate APC's tumor suppressor function is less clear. Here we report that activation of YAP, the downstream effector of the Hippo signaling pathway, is a general hallmark of tubular adenomas from FAP patients. We show that APC functions as a scaffold protein that facilitates the Hippo kinase cascade by interacting with Sav1 and Lats1. Consistent with the molecular link between APC and the Hippo signaling pathway, genetic analysis reveals that YAP is absolutely required for the development of APC-deficient adenomas. These findings establish Hippo–YAP signaling as a critical effector pathway downstream from APC, independent from its involvement in the β-catenin destruction complex. PMID:26193883

USP7 Is a Tumor-Specific WNT Activator for APC-Mutated Colorectal Cancer by Mediating β-Catenin Deubiquitination.

PubMed

Novellasdemunt, Laura; Foglizzo, Valentina; Cuadrado, Laura; Antas, Pedro; Kucharska, Anna; Encheva, Vesela; Snijders, Ambrosius P; Li, Vivian S W

2017-10-17

The tumor suppressor gene adenomatous polyposis coli (APC) is mutated in most colorectal cancers (CRCs), resulting in constitutive Wnt activation. To understand the Wnt-activating mechanism of the APC mutation, we applied CRISPR/Cas9 technology to engineer various APC-truncated isogenic lines. We find that the β-catenin inhibitory domain (CID) in APC represents the threshold for pathological levels of Wnt activation and tumor transformation. Mechanistically, CID-deleted APC truncation promotes β-catenin deubiquitination through reverse binding of β-TrCP and USP7 to the destruction complex. USP7 depletion in APC-mutated CRC inhibits Wnt activation by restoring β-catenin ubiquitination, drives differentiation, and suppresses xenograft tumor growth. Finally, the Wnt-activating role of USP7 is specific to APC mutations; thus, it can be used as a tumor-specific therapeutic target for most CRCs. Copyright © 2017 The Francis Crick Institute. Published by Elsevier Inc. All rights reserved.

Epithelial Membrane Protein 2 and β1 integrin signaling regulate APC-mediated processes.

PubMed

Lesko, Alyssa C; Prosperi, Jenifer R

2017-01-01

Adenomatous Polyposis Coli (APC) plays a critical role in cell motility, maintenance of apical-basal polarity, and epithelial morphogenesis. We previously demonstrated that APC loss in Madin Darby Canine Kidney (MDCK) cells increases cyst size and inverts polarity independent of Wnt signaling, and upregulates the tetraspan protein, Epithelial Membrane Protein 2 (EMP2). Herein, we show that APC loss increases β1 integrin expression and migration of MDCK cells. Through 3D in vitro model systems and 2D migration analysis, we have depicted the molecular mechanism(s) by which APC influences polarity and cell motility. EMP2 knockdown in APC shRNA cells revealed that APC regulates apical-basal polarity and cyst size through EMP2. Chemical inhibition of β1 integrin and its signaling components, FAK and Src, indicated that APC controls cyst size and migration, but not polarity, through β1 integrin and its downstream targets. Combined, the current studies have identified two distinct and novel mechanisms required for APC to regulate polarity, cyst size, and cell migration independent of Wnt signaling. Copyright © 2016 Elsevier Inc. All rights reserved.

WD40 domain of Apc1 is critical for the coactivator-induced allosteric transition that stimulates APC/C catalytic activity.

PubMed

Li, Qiuhong; Chang, Leifu; Aibara, Shintaro; Yang, Jing; Zhang, Ziguo; Barford, David

2016-09-20

The anaphase-promoting complex/cyclosome (APC/C) is a large multimeric cullin-RING E3 ubiquitin ligase that orchestrates cell-cycle progression by targeting cell-cycle regulatory proteins for destruction via the ubiquitin proteasome system. The APC/C assembly comprises two scaffolding subcomplexes: the platform and the TPR lobe that together coordinate the juxtaposition of the catalytic and substrate-recognition modules. The platform comprises APC/C subunits Apc1, Apc4, Apc5, and Apc15. Although the role of Apc1 as an APC/C scaffolding subunit has been characterized, its specific functions in contributing toward APC/C catalytic activity are not fully understood. Here, we report the crystal structure of the N-terminal domain of human Apc1 (Apc1N) determined at 2.2-Å resolution and provide an atomic-resolution description of the architecture of its WD40 (WD40 repeat) domain (Apc1(WD40)). To understand how Apc1(WD40) contributes to APC/C activity, a mutant form of the APC/C with Apc1(WD40) deleted was generated and evaluated biochemically and structurally. We found that the deletion of Apc1(WD40) abolished the UbcH10-dependent ubiquitination of APC/C substrates without impairing the Ube2S-dependent ubiquitin chain elongation activity. A cryo-EM structure of an APC/C-Cdh1 complex with Apc1(WD40) deleted showed that the mutant APC/C is locked into an inactive conformation in which the UbcH10-binding site of the catalytic module is inaccessible. Additionally, an EM density for Apc15 is not visible. Our data show that Apc1(WD40) is required to mediate the coactivator-induced conformational change of the APC/C that is responsible for stimulating APC/C catalytic activity by promoting UbcH10 binding. In contrast, Ube2S activity toward APC/C substrates is not dependent on the initiation-competent conformation of the APC/C.

WD40 domain of Apc1 is critical for the coactivator-induced allosteric transition that stimulates APC/C catalytic activity

PubMed Central

Li, Qiuhong; Chang, Leifu; Aibara, Shintaro; Yang, Jing; Zhang, Ziguo; Barford, David

2016-01-01

The anaphase-promoting complex/cyclosome (APC/C) is a large multimeric cullin–RING E3 ubiquitin ligase that orchestrates cell-cycle progression by targeting cell-cycle regulatory proteins for destruction via the ubiquitin proteasome system. The APC/C assembly comprises two scaffolding subcomplexes: the platform and the TPR lobe that together coordinate the juxtaposition of the catalytic and substrate-recognition modules. The platform comprises APC/C subunits Apc1, Apc4, Apc5, and Apc15. Although the role of Apc1 as an APC/C scaffolding subunit has been characterized, its specific functions in contributing toward APC/C catalytic activity are not fully understood. Here, we report the crystal structure of the N-terminal domain of human Apc1 (Apc1N) determined at 2.2-Å resolution and provide an atomic-resolution description of the architecture of its WD40 (WD40 repeat) domain (Apc1WD40). To understand how Apc1WD40 contributes to APC/C activity, a mutant form of the APC/C with Apc1WD40 deleted was generated and evaluated biochemically and structurally. We found that the deletion of Apc1WD40 abolished the UbcH10-dependent ubiquitination of APC/C substrates without impairing the Ube2S-dependent ubiquitin chain elongation activity. A cryo-EM structure of an APC/C–Cdh1 complex with Apc1WD40 deleted showed that the mutant APC/C is locked into an inactive conformation in which the UbcH10-binding site of the catalytic module is inaccessible. Additionally, an EM density for Apc15 is not visible. Our data show that Apc1WD40 is required to mediate the coactivator-induced conformational change of the APC/C that is responsible for stimulating APC/C catalytic activity by promoting UbcH10 binding. In contrast, Ube2S activity toward APC/C substrates is not dependent on the initiation-competent conformation of the APC/C. PMID:27601667

Parkin New Cargos: a New ROS Independent Role for Parkin in Regulating Cell Division.

PubMed

Stieg, David C; Cooper, Katrina F

2016-01-01

Cell cycle progression requires the destruction of key cell cycle regulators by the multi-subunit E3 ligase called the anaphase promoting complex (APC/C). As the cell progresses through the cell cycle, the APC/C is sequentially activated by two highly conserved co-activators called Cdc20 and Cdh1. Importantly, APC/C Cdc20 is required to degrade substrates in G2/M whereas APC Cdh1 drives the cells into G1. Recently, Parkin, a monomeric E3 ligase that is required for ubiquitin-mediated mitophagy following mitochondrial stress, was shown to both bind and be activated by Cdc20 or Cdh1 during the cell cycle. This mitotic role for Parkin does not require an activating phosphorylation by its usual kinase partner PINK. Rather, mitotic Parkin activity requires phosphorylation on a different serine by the polo-like kinase Plk1. Interestingly, although Parkin Cdc20 and Parkin Cdh1 activity is independent of the APC/C, it mediates degradation of an overlapping subset of substrates. However, unlike the APC/C, Parkin is not necessary for cell cycle progression. Despite this, loss of Parkin activity accelerates genome instability and tumor growth in xenograft models. These findings provide a mechanism behind the previously described, but poorly understood, tumor suppressor role for Parkin. Taken together, studies suggest that the APC/C and Parkin have similar and unique roles to play in cell division, possibly being dependent upon the different subcellular address of these two ligases.

Reversible Modification of Adenomatous Polyposis Coli (APC) with K63-linked Polyubiquitin Regulates the Assembly and Activity of the β-Catenin Destruction Complex

PubMed Central

Tran, Hoanh; Polakis, Paul

2012-01-01

The adenomatous polyposis coli (APC) tumor suppressor forms a complex with Axin and GSK3β to promote the phosphorylation and degradation of β-catenin, a key co-activator of Wnt-induced transcription. Here, we establish that APC is modified predominantly with K63-linked ubiquitin chains when it is bound to Axin in unstimulated HEK293 cells. Wnt3a stimulation induced a time-dependent loss of K63-polyubiquitin adducts from APC, an effect synchronous with the dissociation of Axin from APC and the stabilization of cytosolic β-catenin. RNAi-mediated depletion of Axin or β-catenin, which negated the association between APC and Axin, resulted in the absence of K63-adducts on APC. Overexpression of wild-type and phosphodegron-mutant β-catenin, combined with analysis of thirteen human cancer cell lines that harbor oncogenic mutations in APC, Axin, or β-catenin, support the hypothesis that a fully assembled APC-Axin-GSK3β-phospho-β-catenin complex is necessary for the K63-polyubiquitylation of APC. Intriguingly, the degree of this modification on APC appears to correlate inversely with the levels of β-catenin in cells. Together, our results indicate that K63-linked polyubiquitin adducts on APC regulate the assembly and/or efficiency of the β-catenin destruction complex. PMID:22761442

Atomic structure of the APC/C and its mechanism of protein ubiquitination

PubMed Central

Yang, Jing; McLaughlin, Stephen H.; Barford, David

2015-01-01

The anaphase-promoting complex (APC/C) is a multimeric RING E3 ubiquitin ligase that controls chromosome segregation and mitotic exit. Its regulation by coactivator subunits, phosphorylation, the mitotic checkpoint complex, and interphase inhibitor Emi1 ensures the correct order and timing of distinct cell cycle transitions. Here, we used cryo-electron microscopy to determine atomic structures of APC/C-coactivator complexes with either Emi1 or a UbcH10-ubiquitin conjugate. These structures define the architecture of all APC/C subunits, the position of the catalytic module, and explain how Emi1 mediates inhibition of the two E2s UbcH10 and Ube2S. Definition of Cdh1 interactions with the APC/C indicates how they are antagonized by Cdh1 phosphorylation. The structure of the APC/C with UbcH10-ubiquitin reveals insights into the initiating ubiquitination reaction. Our results provide a quantitative framework for the design of experiments to further investigate APC/C functions in vivo. PMID:26083744

Neurotensin receptor 1 gene activation by the Tcf/beta-catenin pathway is an early event in human colonic adenomas.

PubMed

Souazé, Frédérique; Viardot-Foucault, Véronique; Roullet, Nicolas; Toy-Miou-Leong, Mireille; Gompel, Anne; Bruyneel, Erik; Comperat, Eva; Faux, Maree C; Mareel, Marc; Rostène, William; Fléjou, Jean-François; Gespach, Christian; Forgez, Patricia

2006-04-01

Alterations in the Wnt/APC (adenomatous polyposis coli) signalling pathway, resulting in beta-catenin/T cell factor (Tcf)-dependent transcriptional gene activation, are frequently detected in familial and sporadic colon cancers. The neuropeptide neurotensin (NT) is widely distributed in the gastrointestinal tract. Its proliferative and survival effects are mediated by a G-protein coupled receptor, the NT1 receptor. NT1 receptor is not expressed in normal colon epithelial cells, but is over expressed in a number of cancer cells and tissues suggesting a link to the outgrowth of human colon cancer. Our results demonstrate that the upregulation of NT1 receptor occurring in colon cancer is the result of Wnt/APC signalling pathway activation. We first established the functionality of the Tcf response element within the NT1 receptor promoter. Consequently, we observed the activation of NT1 receptor gene by agents causing beta-catenin cytosolic accumulation, as well as a strong decline of endogenous receptor when wt-APC was restored. At the cellular level, the re-establishment of wt-APC phenotype resulted in the impaired functionality of NT1 receptor, like the breakdown in NT-induced intracellular calcium mobilization and the loss of NT pro-invasive effect. We corroborated the Wnt/APC signalling pathway on the NT1 receptor promoter activation with human colon carcinogenesis, and showed that NT1 receptor gene activation was perfectly correlated with nuclear or cytoplasmic beta-catenin localization while NT1 receptor was absent when beta-catenin was localized at the cell-cell junction in early adenomas of patients with familial adenomatous polyposis, hereditary non-polyposis colorectal cancer and loss of heterozygosity tumours. In this report we establish a novel link in vitro between the Tcf/beta-catenin pathway and NT1 receptor promoter activation.

Structures of the APC-ARM domain in complexes with discrete Amer1/WTX fragments reveal that it uses a consensus mode to recognize its binding partners.

PubMed

Zhang, Zhenyi; Akyildiz, Senem; Xiao, Yafei; Gai, Zhongchao; An, Ying; Behrens, Jürgen; Wu, Geng

2015-01-01

The tumor suppressor APC employs its conserved armadillo repeat (ARM) domain to recognize many of its binding partners, including Amer1/WTX, which is mutated in Wilms' tumor and bone overgrowth syndrome. The APC-Amer1 complex has important roles in regulating Wnt signaling and cell adhesion. Three sites A1, A2, and A3 of Amer1 have been reported to mediate its interaction with APC-ARM. In this study, crystal structures of APC-ARM in complexes with Amer1-A1, -A2, and -A4, which is newly identified in this work, were determined. Combined with our GST pull-down, yeast two-hybrid, and isothermal titration calorimetry (ITC) assay results using mutants of APC and Amer1 interface residues, our structures demonstrate that Amer1-A1, -A2, and -A4, as well as other APC-binding proteins such as Asef and Sam68, all employ a common recognition pattern to associate with APC-ARM. In contrast, Amer1-A3 binds to the C-terminal side of APC-ARM through a bipartite interaction mode. Composite mutations on either APC or Amer1 disrupting all four interfaces abrogated their association in cultured cells and impaired the membrane recruitment of APC by Amer1. Our study thus comprehensively elucidated the recognition mechanism between APC and Amer1, and revealed a consensus recognition sequence employed by various APC-ARM binding partners.

APC sets the Wnt tone necessary for cerebral cortical progenitor development.

PubMed

Nakagawa, Naoki; Li, Jingjun; Yabuno-Nakagawa, Keiko; Eom, Tae-Yeon; Cowles, Martis; Mapp, Tavien; Taylor, Robin; Anton, E S

2017-08-15

Adenomatous polyposis coli (APC) regulates the activity of β-catenin, an integral component of Wnt signaling. However, the selective role of the APC-β-catenin pathway in cerebral cortical development is unknown. Here we genetically dissected the relative contributions of APC-regulated β-catenin signaling in cortical progenitor development, a necessary early step in cerebral cortical formation. Radial progenitor-specific inactivation of the APC-β-catenin pathway indicates that the maintenance of appropriate β-catenin-mediated Wnt tone is necessary for the orderly differentiation of cortical progenitors and the resultant formation of the cerebral cortex. APC deletion deregulates β-catenin, leads to high Wnt tone, and disrupts Notch1 signaling and primary cilium maintenance necessary for radial progenitor functions. β-Catenin deregulation directly disrupts cilium maintenance and signaling via Tulp3, essential for intraflagellar transport of ciliary signaling receptors. Surprisingly, deletion of β-catenin or inhibition of β-catenin activity in APC-null progenitors rescues the APC-null phenotype. These results reveal that APC-regulated β-catenin activity in cortical progenitors sets the appropriate Wnt tone necessary for normal cerebral cortical development. © 2017 Nakagawa et al.; Published by Cold Spring Harbor Laboratory Press.

Investigation into chromophore excited-state coupling in allophycocyanin

NASA Astrophysics Data System (ADS)

Zheng, Xiguang; Zhao, Fuli; Wang, He Z.; Gao, Zhaolan; Yu, Zhenxin; Zhu, Jinchang; Xia, Andong; Jiang, Lijin

1994-08-01

Both theoretical and experimental studies are presented on chromophore excited-state coupling in linker-free allophycocyanin (APC), one of the antenna phycobiliproteins in algal photosynthesis. A three-site-coupling model has been introduced to describe the exciton interaction mechanism amoung the excited (beta) chromophore in APC, and the exciton energy splitting is estimated. Picosecond polarized fluorescence experiments both on monomeric and trimeric APC isolated from alga Spirulina platensis have been performed. The experimental results show that APC monomer and trimer exhibit remarkedly different spectropic characteristics, and satisfy the suggestion of strong excited- state coupling among chromophores in APC.

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

Burgess, Antony W., E-mail: burgess@ludwig.edu.au; Faux, Maree C.; Layton, Meredith J.

In this brief overview we discuss the association between Wnt signaling and colon cell biology and tumorigenesis. Our current understanding of the role of Apc in the {beta}-catenin destruction complex is compared with potential roles for Apc in cell adhesion and migration. The requirement for phosphorylation in the proteasomal-mediated degradation of {beta}-catenin is contrasted with roles for phospho-{beta}-catenin in the activation of transcription, cell adhesion and migration. The synergy between Myb and {beta}-catenin regulation of transcription in crypt stem cells during Wnt signaling is discussed. Finally, potential effects of growth factor regulatory systems, Apc or truncated-Apc on crypt morphogenesis, stemmore » cell localization and crypt fission are considered.« less

Prostanoids and their receptors that modulate dendritic cell-mediated immunity.

PubMed

Gualde, Norbert; Harizi, Hedi

2004-08-01

Dendritic cells (DC) are essential for the initiation of immune responses by capturing, processing and presenting antigens to T cells. In addition to their important role as professional APC, they are able to produce immunosuppressive and pro-inflammatory prostanoids from arachidonic acid (AA) by the action of cyclooxygenase (COX) enzymes. In an autocrine and paracrine fashion, the secreted lipid mediators subsequently modulate the maturation, cytokine production, Th-cell polarizing ability, chemokine receptor expression, migration, and apoptosis of these extremely versatile APC. The biological actions of prostanoids, including their effects on APC-mediated immunity and acute inflammatory responses, are exerted by G protein-coupled receptors on plasma membrane. Some COX metabolites act as anti-inflammatory lipid mediators by binding to nuclear receptors and modulating DC functions. Although the role of cytokines in DC function has been studied extensively, the effects of prostanoids on DC biology have only recently become the focus of investigation. This review summarizes the current knowledge about the role of prostanoids and their receptors in modulating DC function and the subsequent immune responses.

Cell painting with an engineered EPCR to augment the protein C system.

PubMed

Bouwens, Eveline A M; Stavenuiter, Fabian; Mosnier, Laurent O

2015-11-25

The protein C (PC) system conveys beneficial anticoagulant and cytoprotective effects in numerous in vivo disease models. The endothelial protein C receptor (EPCR) plays a central role in these pathways as cofactor for PC activation and by enhancing activated protein C (APC)-mediated protease-activated receptor (PAR) activation. During inflammatory disease, expression of EPCR on cell membranes is often diminished thereby limiting PC activation and APC's effects on cells. Here a caveolae-targeting glycosylphosphatidylinositol (GPI)-anchored EPCR (EPCR-GPI) was engineered to restore EPCR's bioavailability via "cell painting." The painting efficiency of EPCR-GPI on EPCR-depleted endothelial cells was time- and dose-dependent. The EPCR-GPI bioavailability after painting was long lasting since EPCR surface levels reached 400 % of wild-type cells after 2 hours and remained > 200 % for 24 hours. EPCR-GPI painting conveyed APC binding to EPCR-depleted endothelial cells where EPCR was lost due to shedding or shRNA. EPCR painting normalised PC activation on EPCR-depleted cells indicating that EPCR-GPI is functional active on painted cells. Caveolin-1 lipid rafts were enriched in EPCR after painting due to the GPI-anchor targeting caveolae. Accordingly, EPCR painting supported PAR1 and PAR3 cleavage by APC and augmented PAR1-dependent Akt phosphorylation by APC. Thus, EPCR-GPI painting achieved physiological relevant surface levels on endothelial cells, restored APC binding to EPCR-depleted cells, supported PC activation, and enhanced APC-mediated PAR cleavage and cytoprotective signalling. Therefore, EPCR-GPI provides a novel tool to restore the bioavailability and functionality of EPCR on EPCR- depleted and -deficient cells.

APC binds the Miro/Milton motor complex to stimulate transport of mitochondria to the plasma membrane.

PubMed

Mills, Kate M; Brocardo, Mariana G; Henderson, Beric R

2016-02-01

Mutations in adenomatous polyposis coli (APC) disrupt regulation of Wnt signaling, mitosis, and the cytoskeleton. We describe a new role for APC in the transport of mitochondria. Silencing of wild-type APC by small interfering RNA caused mitochondria to redistribute from the cell periphery to the perinuclear region. We identified novel APC interactions with the mitochondrial kinesin-motor complex Miro/Milton that were mediated by the APC C-terminus. Truncating mutations in APC abolished its ability to bind Miro/Milton and reduced formation of the Miro/Milton complex, correlating with disrupted mitochondrial distribution in colorectal cancer cells that could be recovered by reconstitution of wild-type APC. Using proximity ligation assays, we identified endogenous APC-Miro/Milton complexes at mitochondria, and live-cell imaging showed that loss of APC slowed the frequency of anterograde mitochondrial transport to the membrane. We propose that APC helps drive mitochondria to the membrane to supply energy for cellular processes such as directed cell migration, a process disrupted by cancer mutations. © 2016 Mills et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

Activated protein C ameliorates Bacillus anthracis lethal toxin-induced lethal pathogenesis in rats

PubMed Central

2012-01-01

Background Lethal toxin (LT) is a major virulence factor of Bacillus anthracis. Sprague Dawley rats manifest pronounced lung edema and shock after LT treatments, resulting in high mortality. The heart failure that is induced by LT has been suggested to be a principal mechanism of lung edema and mortality in rodents. Since LT-induced death occurs more rapidly in rats than in mice, suggesting that other mechanisms in addition to the heart dysfunction may be contributed to the fast progression of LT-induced pathogenesis in rats. Coagulopathy may contribute to circulatory failure and lung injury. However, the effect of LT on coagulation-induced lung dysfunction is unclear. Methods To investigate the involvement of coagulopathy in LT-mediated pathogenesis, the mortality, lung histology and coagulant levels of LT-treated rats were examined. The effects of activated protein C (aPC) on LT-mediated pathogenesis were also evaluated. Results Fibrin depositions were detected in the lungs of LT-treated rats, indicating that coagulation was activated. Increased levels of plasma D-dimer and thrombomodulin, and the ameliorative effect of aPC further suggested that the activation of coagulation-fibrinolysis pathways plays a role in LT-mediated pathogenesis in rats. Reduced mortality was associated with decreased plasma levels of D-dimer and thrombomodulin following aPC treatments in rats with LT-mediated pathogenesis. Conclusions These findings suggest that the activation of coagulation in lung tissue contributes to mortality in LT-mediated pathogenesis in rats. In addition, anticoagulant aPC may help to develop a feasible therapeutic strategy. PMID:23170801

Fission Yeast Apc15 Stabilizes MCC-Cdc20-APC/C Complexes, Ensuring Efficient Cdc20 Ubiquitination and Checkpoint Arrest.

PubMed

May, Karen M; Paldi, Flora; Hardwick, Kevin G

2017-04-24

During mitosis, cells must segregate the replicated copies of their genome to their daughter cells with extremely high fidelity. Segregation errors lead to an abnormal chromosome number (aneuploidy), which typically results in disease or cell death [1]. Chromosome segregation and anaphase onset are initiated through the action of the multi-subunit E3 ubiquitin ligase known as the anaphase-promoting complex or cyclosome (APC/C [2]). The APC/C is inhibited by the spindle checkpoint in the presence of kinetochore attachment defects [3, 4]. Here we demonstrate that two non-essential APC/C subunits (Apc14 and Apc15) regulate association of spindle checkpoint proteins, in the form of the mitotic checkpoint complex (MCC), with the APC/C. apc14Δ mutants display increased MCC association with the APC/C and are unable to silence the checkpoint efficiently. Conversely, apc15Δ mutants display reduced association between the MCC and APC/C, are defective in poly-ubiquitination of Cdc20, and are checkpoint defective. In vitro reconstitution studies have shown that human MCC-APC/C can contain two molecules of Cdc20 [5-7]. Using a yeast strain expressing two Cdc20 genes with different epitope tags, we show by co-immunoprecipitation that this is true in vivo. MCC binding to the second molecule of Cdc20 is mediated via the C-terminal KEN box in Mad3. Somewhat surprisingly, complexes containing both molecules of Cdc20 accumulate in apc15Δ cells, and the implications of this observation are discussed. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Self-association of the APC tumor suppressor is required for the assembly, stability, and activity of the Wnt signaling destruction complex

PubMed Central

Kunttas-Tatli, Ezgi; Roberts, David M.; McCartney, Brooke M.

2014-01-01

The tumor suppressor adenomatous polyposis coli (APC) is an essential negative regulator of Wnt signaling through its activity in the destruction complex with Axin, GSK3β, and CK1 that targets β-catenin/Armadillo (β-cat/Arm) for proteosomal degradation. The destruction complex forms macromolecular particles we termed the destructosome. Whereas APC functions in the complex through its ability to bind both β-cat and Axin, we hypothesize that APC proteins play an additional role in destructosome assembly through self-association. Here we show that a novel N-terminal coil, the APC self-association domain (ASAD), found in vertebrate and invertebrate APCs, directly mediates self-association of Drosophila APC2 and plays an essential role in the assembly and stability of the destructosome that regulates β-cat degradation in Drosophila and human cells. Consistent with this, removal of the ASAD from the Drosophila embryo results in β-cat/Arm accumulation and aberrant Wnt pathway activation. These results suggest that APC proteins are required not only for the activity of the destructosome, but also for the assembly and stability of this macromolecular machine. PMID:25208568

State of the APC/C: Organization, function, and structure

PubMed Central

McLean, Janel R.; Chaix, Denis; Ohi, Melanie D.; Gould, Kathleen L.

2016-01-01

The ubiquitin-proteasome protein degradation system is involved in many essential cellular processes including cell cycle regulation, cell differentiation, and the unfolded protein response.The anaphase-promoting complex/cyclosome (APC/C), an evolutionary conserved E3 ubiquitin ligase, was discovered 15 years ago because of its pivotal role in cyclin degradation and mitotic progression. Since then, we have learned that the APC/C is a very large, complex E3 ligase composed of 13 subunits, yielding a molecular machine of approximately 1 MDa. The intricate regulation of the APC/C is mediated by the Cdc20 family of activators, pseudosubstrate inhibitors, protein kinases and phosphatases and the spindle assembly checkpoint. The large size, complexity, and dynamic nature of the APC/C represent significant obstacles toward high-resolution structural techniques; however, over the last decade, there have been a number of lower resolution APC/C structures determined using single particle electron microscopy. These structures, when combined with data generated from numerous genetic and biochemical studies, have begun to shed light on how APC/C activity is regulated. Here, we discuss the most recent developments in the APC/C field concerning structure, substrate recognition, and catalysis. PMID:21261459

Visualizing the complex functions and mechanisms of the anaphase promoting complex/cyclosome (APC/C)

PubMed Central

Alfieri, Claudio; Zhang, Suyang

2017-01-01

The anaphase promoting complex or cyclosome (APC/C) is a large multi-subunit E3 ubiquitin ligase that orchestrates cell cycle progression by mediating the degradation of important cell cycle regulators. During the two decades since its discovery, much has been learnt concerning its role in recognizing and ubiquitinating specific proteins in a cell-cycle-dependent manner, the mechanisms governing substrate specificity, the catalytic process of assembling polyubiquitin chains on its target proteins, and its regulation by phosphorylation and the spindle assembly checkpoint. The past few years have witnessed significant progress in understanding the quantitative mechanisms underlying these varied APC/C functions. This review integrates the overall functions and properties of the APC/C with mechanistic insights gained from recent cryo-electron microscopy (cryo-EM) studies of reconstituted human APC/C complexes. PMID:29167309

APC sets the Wnt tone necessary for cerebral cortical progenitor development

PubMed Central

Nakagawa, Naoki; Li, Jingjun; Yabuno-Nakagawa, Keiko; Eom, Tae-Yeon; Cowles, Martis; Mapp, Tavien; Taylor, Robin; Anton, E.S.

2017-01-01

Adenomatous polyposis coli (APC) regulates the activity of β-catenin, an integral component of Wnt signaling. However, the selective role of the APC–β-catenin pathway in cerebral cortical development is unknown. Here we genetically dissected the relative contributions of APC-regulated β-catenin signaling in cortical progenitor development, a necessary early step in cerebral cortical formation. Radial progenitor-specific inactivation of the APC–β-catenin pathway indicates that the maintenance of appropriate β-catenin-mediated Wnt tone is necessary for the orderly differentiation of cortical progenitors and the resultant formation of the cerebral cortex. APC deletion deregulates β-catenin, leads to high Wnt tone, and disrupts Notch1 signaling and primary cilium maintenance necessary for radial progenitor functions. β-Catenin deregulation directly disrupts cilium maintenance and signaling via Tulp3, essential for intraflagellar transport of ciliary signaling receptors. Surprisingly, deletion of β-catenin or inhibition of β-catenin activity in APC-null progenitors rescues the APC-null phenotype. These results reveal that APC-regulated β-catenin activity in cortical progenitors sets the appropriate Wnt tone necessary for normal cerebral cortical development. PMID:28916710

Identification of Mom12 and Mom13, two novel modifier loci of Apc (Min) -mediated intestinal tumorigenesis.

PubMed

Crist, Richard C; Roth, Jacquelyn J; Lisanti, Michael P; Siracusa, Linda D; Buchberg, Arthur M

2011-04-01

Colorectal cancer is a heterogeneous disease resulting from a combination of genetic and environmental factors. The C57BL/6J (B6) Apc (Min/+) mouse develops polyps throughout the gastrointestinal tract and has been a valuable model for understanding the genetic basis of intestinal tumorigenesis. Apc (Min/+) mice have been used to study known oncogenes and tumor suppressor genes on a controlled genetic background. These studies often utilize congenic knockout alleles, which can carry an unknown amount of residual donor DNA. The Apc (Min) model has also been used to identify modifer loci, known as Modifier of Min (Mom) loci, which alter Apc (Min) -mediated intestinal tumorigenesis. B6 mice carrying a knockout allele generated in WW6 embryonic stem cells were crossed to B6 Apc (Min/+) mice to determine the effect on polyp multiplicity. The newly generated colony developed significantly more intestinal polyps than Apc (Min/+) controls. Polyp multiplicity did not correlate with inheritance of the knockout allele, suggesting the presence of one or more modifier loci segregating in the colony. Genotyping of simple sequence length polymorphism (SSLP) markers revealed residual 129X1/SvJ genomic DNA within the congenic region of the parental knockout line. An analysis of polyp multiplicity data and SSLP genotyping indicated the presence of two Mom loci in the colony: 1) Mom12, a dominant modifier linked to the congenic region on chromosome 6, and 2) Mom13, which is unlinked to the congenic region and whose effect is masked by Mom12. The identification of Mom12 and Mom13 demonstrates the potential problems resulting from residual heterozygosity present in congenic lines.

Role of Heat Shock Protein 90 and Endothelial Nitric Oxide Synthase during Early Anesthetic and Ischemic Preconditioning

PubMed Central

Amour, Julien; Brzezinska, Anna K.; Weihrauch, Dorothee; Billstrom, Amie R.; Zielonka, Jacek; Krolikowski, John G.; Bienengraeber, Martin W.; Warltier, David C.; Pratt, Philip F.; Kersten, Judy R.

2009-01-01

Background Nitric oxide is known to be essential for early anesthetic (APC) and ischemic (IPC) preconditioning of myocardium. Heat shock protein 90 (Hsp90) regulates endothelial nitric oxide synthase (eNOS) activity. In this study, we tested the hypothesis that Hsp90-eNOS interactions modulate APC and IPC. Methods Myocardial infarct size was measured in rabbits after coronary occlusion and reperfusion in the absence or presence of preconditioning with 30 min of isoflurane (APC) or 5 min of coronary artery occlusion (IPC), and with or without pre-treatment with geldanamycin or radicicol, two chemically distinct Hsp90 inhibitors, or NG-nitro-L-arginine methylester, a non-specific NOS inhibitor. Isoflurane-dependent nitric oxide production was measured (ozone chemiluminescence) in human coronary artery endothelial cells or mouse cardiomyocytes, in the absence or presence of Hsp90 inhibitors or NG-nitro-L-arginine methylester. Interactions between Hsp90 and eNOS, and eNOS activation were assessed with immunoprecipitation, immunoblotting, and confocal microscopy. Results APC and IPC decreased infarct size (50% and 59%, respectively) and this action was abolished by Hsp90 inhibitors. NG-nitro-L-arginine methylester blocked APC but not IPC. Isoflurane increased nitric oxide production in human coronary artery endothelial cells, concomitantly with an increase in Hsp90-eNOS interaction (immunoprecipitation, immunoblotting, and immunohistochemistry). Pretreatment with Hsp90 inhibitors abolished isoflurane-dependent nitric oxide production and decreased Hsp90-eNOS interactions. Isoflurane did not increase nitric oxide production in mouse cardiomyocytes and eNOS was below the level of detection. Conclusion The results indicate that Hsp90 plays a critical role in mediating APC and IPC through protein-protein interactions, and suggest that endothelial cells are important contributors to nitric oxide-mediated signalling during APC. PMID:19194158

Cyclosporine-resistant, Rab27a-independent Mobilization of Intracellular Preformed CD40L Mediates Antigen-specific T Cell Help In Vitro

PubMed Central

Koguchi, Yoshinobu; Gardell, Jennifer L.; Thauland, Timothy J.; Parker, David C.

2011-01-01

CD40L is critically important for the initiation and maintenance of adaptive immune responses. It is generally thought that CD40L expression in CD4+ T cells is regulated transcriptionally and made from new mRNA following antigen recognition. However, recent studies with two-photon microscopy revealed that the majority of cognate interactions between effector CD4+ T cells and APCs are too short for de novo synthesis of CD40L. Given that effector and memory CD4+ T cells store preformed CD40L (pCD40L) in lysosomal compartments and that pCD40L comes to the cell surface within minutes of antigenic stimulation, we and others have proposed that pCD40L might mediate T cell-dependent activation of cognate APCs during brief encounters in vivo. However, it has not been shown that this relatively small amount of pCD40L is sufficient to activate APCs, owing to the difficulty of separating the effects of pCD40L from those of de novo CD40L and other cytokines in vitro. Here we show that pCD40L surface mobilization is resistant to cyclosporine or FK506 treatment, while de novo CD40L and cytokine expression are completely inhibited. These drugs thus provide a tool to dissect the role of pCD40L in APC activation. We find that pCD40L mediates selective activation of cognate but not bystander APCs in vitro and that mobilization of pCD40L does not depend on Rab27a, which is required for mobilization of lytic granules. Therefore, effector CD4+ T cells deliver pCD40L specifically to APCs on the same time scale as the lethal hit of CTLs but with distinct molecular machinery. PMID:21677130

Molecular mechanism of APC/C activation by mitotic phosphorylation

PubMed Central

Alfieri, Claudio; Zhang, Ziguo; Yang, Jing; Maslen, Sarah; Skehel, Mark; Barford, David

2016-01-01

In eukaryotes, the anaphase-promoting complex/cyclosome (APC/C) regulates the ubiquitin-dependent proteolysis of specific cell cycle proteins to coordinate chromosome segregation in mitosis and entry into G1 (refs 1,2). The APC/C’s catalytic activity and ability to specify the destruction of particular proteins at different phases of the cell cycle are controlled by its interaction with two structurally related coactivator subunits (Cdc20 and Cdh1). Coactivators recognize substrate degrons3, and enhance the APC/C’s affinity for its cognate E2 (refs 4–6). During mitosis, cyclin-dependent kinase and polo kinase control Cdc20 and Cdh1-mediated activation of the APC/C. Hyper-phosphorylation of APC/C subunits, notably Apc1 and Apc3, is required for Cdc20 to activate the APC/C7–12, whereas phosphorylation of Cdh1 prevents its association with the APC/C9,13,14. Since both coactivators associate with the APC/C through their common C box15 and IR (Ile-Arg) tail motifs16,17, the mechanism underlying this differential regulation is unclear, as is the role of specific APC/C phosphorylation sites. Here, using cryo-electron microscopy (cryo-EM) and biochemical analysis, we define the molecular basis of how APC/C phosphorylation allows for its control by Cdc20. An auto-inhibitory (AI) segment of Apc1 acts as a molecular switch that in apo unphosphorylated APC/C interacts with the C-box binding site and obstructs engagement of Cdc20. Phosphorylation of the AI segment displaces it from the C-box binding site. Efficient phosphorylation of the AI segment, and thus relief of auto-inhibition, requires the recruitment of Cdk-cyclin-Cks to a hyper-phosphorylated loop of Apc3. We also find that the small molecule inhibitor, tosyl-L-arginine methyl ester (TAME), preferentially suppresses APC/CCdc20 rather than APC/CCdh1, and interacts with both the C-box and IR-tail binding sites. Our results reveal the mechanism for the regulation of mitotic APC/C by phosphorylation and provide a rationale for the development of selective inhibitors of this state. PMID:27120157

Molecular mechanism of APC/C activation by mitotic phosphorylation.

PubMed

Zhang, Suyang; Chang, Leifu; Alfieri, Claudio; Zhang, Ziguo; Yang, Jing; Maslen, Sarah; Skehel, Mark; Barford, David

2016-05-12

In eukaryotes, the anaphase-promoting complex (APC/C, also known as the cyclosome) regulates the ubiquitin-dependent proteolysis of specific cell-cycle proteins to coordinate chromosome segregation in mitosis and entry into the G1 phase. The catalytic activity of the APC/C and its ability to specify the destruction of particular proteins at different phases of the cell cycle are controlled by its interaction with two structurally related coactivator subunits, Cdc20 and Cdh1. Coactivators recognize substrate degrons, and enhance the affinity of the APC/C for its cognate E2 (refs 4-6). During mitosis, cyclin-dependent kinase (Cdk) and polo-like kinase (Plk) control Cdc20- and Cdh1-mediated activation of the APC/C. Hyperphosphorylation of APC/C subunits, notably Apc1 and Apc3, is required for Cdc20 to activate the APC/C, whereas phosphorylation of Cdh1 prevents its association with the APC/C. Since both coactivators associate with the APC/C through their common C-box and Ile-Arg tail motifs, the mechanism underlying this differential regulation is unclear, as is the role of specific APC/C phosphorylation sites. Here, using cryo-electron microscopy and biochemical analysis, we define the molecular basis of how phosphorylation of human APC/C allows for its control by Cdc20. An auto-inhibitory segment of Apc1 acts as a molecular switch that in apo unphosphorylated APC/C interacts with the C-box binding site and obstructs engagement of Cdc20. Phosphorylation of the auto-inhibitory segment displaces it from the C-box-binding site. Efficient phosphorylation of the auto-inhibitory segment, and thus relief of auto-inhibition, requires the recruitment of Cdk-cyclin in complex with a Cdk regulatory subunit (Cks) to a hyperphosphorylated loop of Apc3. We also find that the small-molecule inhibitor, tosyl-l-arginine methyl ester, preferentially suppresses APC/C(Cdc20) rather than APC/C(Cdh1), and interacts with the binding sites of both the C-box and Ile-Arg tail motifs. Our results reveal the mechanism for the regulation of mitotic APC/C by phosphorylation and provide a rationale for the development of selective inhibitors of this state.

The effect of a germline mutation in the APC gene on β-catenin in human embryonic stem cells.

PubMed

Yedid, Nofar; Kalma, Yael; Malcov, Mira; Amit, Ami; Kariv, Revital; Caspi, Michal; Rosin-Arbesfeld, Rina; Ben-Yosef, Dalit

2016-12-23

Most cases of colorectal cancer (CRC) are initiated by inactivation mutations in the APC gene, which is a negative regulator of the Wnt-β-catenin pathway. Patients with familial adenomatous polyposis (FAP) inherit a germline mutation in one APC allele, and loss of the second allele leads to the development of polyps that will turn malignant if not removed. It is not fully understood which molecular mechanisms are activated by APC loss and when the loss of the second APC allele occurs. Two FAP human embryonic stem cell (hESCs) lines were derived from APC mutated embryos following pre-implantation genetic diagnosis (PGD) for FAP. These FAP-hESCs were cultured in vitro and following extended culture: 1) β-catenin expression was analyzed by Western blot analysis; 2) Wnt-β-catenin/TCF-mediated transcription luciferase assay was performed; 3) cellular localization of β-catenin was evaluated by immunoflorecence confocal microscopy; and 4) DNA sequencing of the APC gene was performed. We have established a novel human in-vitro model for studying malignant transformation, using hESCs that carry a germline mutation in the APC gene following PGD for FAP. Extended culturing of FAP1 hESCs led to activation of the Wnt signaling pathway, as demonstrated by enhanced β-catenin/TCF-mediated activity. Additionally, β-catenin showed a distinct perinuclear distribution in most (91 %) of the FAP1 hESCs high passage colonies. DNA sequencing of the whole gene detected several polymorphisms in FAP1 hESCs, however, no somatic mutations were discovered in the APC gene. On the other hand, no changes in β-catenin were detected in the FAP2 hESCs, demonstrating the natural diversity of the human FAP population. Our results describe the establishment of novel hESC lines from FAP patients with a predisposition for cancer mutation. These cells can be maintained in culture for long periods of time and may serve as a platform for studying the initial molecular and cellular changes that occur during early stages of malignant transformation.

Generating mixed morphology BaZrO3 artificial pinning centers for strong and isotropic pinning in BaZrO3-Y2O3 double-doped YBCO thin films

NASA Astrophysics Data System (ADS)

Chen, Shihong; Sebastian, Mary Ann; Gautam, Bibek; Wilt, Jamie; Chen, Yanbin; Sun, Lei; Xing, Zhongwen; Haugan, Timothy; Wu, Judy

2017-12-01

High concentration artificial pinning centers (APCs), such as BaZrO3 nanorods (BZO 1D APCs) aligned along the c-axis of the high temperature superconductor YBa2Cu3O7 (YBCO) can provide strong pinning of magnetic vortices and are desirable for applications in high magnetic fields. Unfortunately, in YBCO films with single-doping (SD) of BZO 1D APCs, a monotonic decreasing superconducting T c and critical current density J c(H) with BZO doping has been observed due to strain field overlap at high-concentration perfectly c-axis aligned BZO 1D APCs. In order to resolve this issue, double-doping (DD) of 2-6 vol% BZO 1D APCs and 3.0 vol% Y2O3 nanoparticles (Y2O3-NPs) in YBCO films has been explored to promote BZO-NR orientation misalignment from the c-axis. Remarkably, a monotonic increasing J c(H) with BZO 1D APCs concentration has been obtained in the BZO DD samples. Such a microstructure change is evidenced in the much smaller c-lattice parameter expansion of 0.103% in the DD samples as opposed to 0.511% in the SD counterparts and reduced c-axis alignment of the BZO 1D APCs as revealed in TEM. This yields a mixed 1D + 2D + 3D APC morphology and enhanced isotropic pinning with respect to the orientation of the H-field in the BZO DD samples.

Myelin-reactive antibodies initiate T cell-mediated CNS autoimmune disease by opsonization of endogenous antigen.

PubMed

Kinzel, Silke; Lehmann-Horn, Klaus; Torke, Sebastian; Häusler, Darius; Winkler, Anne; Stadelmann, Christine; Payne, Natalie; Feldmann, Linda; Saiz, Albert; Reindl, Markus; Lalive, Patrice H; Bernard, Claude C; Brück, Wolfgang; Weber, Martin S

2016-07-01

In the pathogenesis of central nervous system (CNS) demyelinating disorders, antigen-specific B cells are implicated to act as potent antigen-presenting cells (APC), eliciting waves of inflammatory CNS infiltration. Here, we provide the first evidence that CNS-reactive antibodies (Ab) are similarly capable of initiating an encephalitogenic immune response by targeting endogenous CNS antigen to otherwise inert myeloid APC. In a transgenic mouse model, constitutive production of Ab against myelin oligodendrocyte glycoprotein (MOG) was sufficient to promote spontaneous experimental autoimmune encephalomyelitis (EAE) in the absence of B cells, when mice endogenously contained MOG-recognizing T cells. Adoptive transfer studies corroborated that anti-MOG Ab triggered activation and expansion of peripheral MOG-specific T cells in an Fc-dependent manner, subsequently causing EAE. To evaluate the underlying mechanism, anti-MOG Ab were added to a co-culture of myeloid APC and MOG-specific T cells. At otherwise undetected concentrations, anti-MOG Ab enabled Fc-mediated APC recognition of intact MOG; internalized, processed and presented MOG activated naïve T cells to differentiate in an encephalitogenic manner. In a series of translational experiments, anti-MOG Ab from two patients with an acute flare of CNS inflammation likewise facilitated detection of human MOG. Jointly, these observations highlight Ab-mediated opsonization of endogenous CNS auto-antigen as a novel disease- and/or relapse-triggering mechanism in CNS demyelinating disorders.

The Basics of Artificial Antigen Presenting Cells in T Cell-Based Cancer Immunotherapies.

PubMed

Neal, Lillian R; Bailey, Stefanie R; Wyatt, Megan M; Bowers, Jacob S; Majchrzak, Kinga; Nelson, Michelle H; Haupt, Carl; Paulos, Chrystal M; Varela, Juan C

2017-01-01

Adoptive T cell transfer (ACT) can mediate objective responses in patients with advanced malignancies. There have been major advances in this field, including the optimization of the ex vivo generation of tumor-reactive lymphocytes to ample numbers for effective ACT therapy via the use of natural and artificial antigen presenting cells (APCs). Herein we review the basic properties of APCs and how they have been manufactured through the years to augment vaccine and T cell-based cancer therapies. We then discuss how these novel APCs impact the function and memory properties of T cells. Finally, we propose new ways to synthesize aAPCs to augment the therapeutic effectiveness of antitumor T cells for ACT therapy.

The Basics of Artificial Antigen Presenting Cells in T Cell-Based Cancer Immunotherapies

PubMed Central

Neal, Lillian R.; Bailey, Stefanie R.; Wyatt, Megan M.; Bowers, Jacob S.; Majchrzak, Kinga; Nelson, Michelle H.; Haupt, Carl; Paulos, Chrystal M.; Varela, Juan C.

2017-01-01

Adoptive T cell transfer (ACT) can mediate objective responses in patients with advanced malignancies. There have been major advances in this field, including the optimization of the ex vivo generation of tumor-reactive lymphocytes to ample numbers for effective ACT therapy via the use of natural and artificial antigen presenting cells (APCs). Herein we review the basic properties of APCs and how they have been manufactured through the years to augment vaccine and T cell-based cancer therapies. We then discuss how these novel APCs impact the function and memory properties of T cells. Finally, we propose new ways to synthesize aAPCs to augment the therapeutic effectiveness of antitumor T cells for ACT therapy. PMID:28825053

MMP-mediated collagen breakdown induced by activated protein C in equine cartilage is reduced by corticosteroids.

PubMed

Garvican, Elaine R; Vaughan-Thomas, Anne; Redmond, Colette; Gabriel, Natalie; Clegg, Peter D

2010-03-01

The plasma serine protease activated protein C (APC) is synthesized by human chondrocytes at sites of pathological cartilage fibrillation. APC levels are increased in osteoarthritis (OA) synovial fluid, and in vitro APC has been shown to synergize with interleukin-1beta (IL-1) to promote degradation from ovine cartilage. A model of equine cartilage degradation was established and used to explore corticosteroid activities. Intraarticular corticosteroids are a commonly prescribed treatment for joint disease, however their role in disease modification remains unclear. APC synergized with IL-1 or tumor necrosis factor-alpha (TNFalpha), promoting significant collagen degradation from equine cartilage explants within 4 days, but did not augment glycoaminoglycan (GAG) release. APC activated pro-matrix metalloproteinases (MMP)-2 but not pro-MMP-9, as assessed by gelatin zymography. APC did not directly activate pro-MMP-13. Dexamethasone, triamcinolone, and methylprednisolone acetate (MPA) were evaluated at concentrations between 10(- 5)M and 10(-10)M. High concentrations significantly increased GAG release from IL-1+APC-treated explants. With the exception of MPA at 10(-10)M, all concentrations of corticosteroids caused significant decreases in IL-1+APC-driven hydroxyproline loss. Treatment with corticosteroids suppressed expression of MMP-1, -3, and -13 mRNA. The collagenolysis associated with IL-1+APC synergy, and the inhibition of this effect by corticosteroids may involve gelatinase activation and downregulation of MMP expression, respectively.

An APC/C-Cdh1 Biosensor Reveals the Dynamics of Cdh1 Inactivation at the G1/S Transition.

PubMed

Ondracka, Andrej; Robbins, Jonathan A; Cross, Frederick R

2016-01-01

B-type cyclin-dependent kinase activity must be turned off for mitotic exit and G1 stabilization. B-type cyclin degradation is mediated by the anaphase-promoting complex/cyclosome (APC/C); during and after mitotic exit, APC/C is dependent on Cdh1. Cdh1 is in turn phosphorylated and inactivated by cyclin-CDK at the Start transition of the new cell cycle. We developed a biosensor to assess the cell cycle dynamics of APC/C-Cdh1. Nuclear exit of the G1 transcriptional repressor Whi5 is a known marker of Start; APC/C-Cdh1 is inactivated 12 min after Whi5 nuclear exit with little measurable cell-to-cell timing variability. Multiple phosphorylation sites on Cdh1 act in a redundant manner to repress its activity. Reducing the number of phosphorylation sites on Cdh1 can to some extent be tolerated for cell viability, but it increases variability in timing of APC/C-Cdh1 inactivation. Mutants with minimal subsets of phosphorylation sites required for viability exhibit striking stochasticity in multiple responses including budding, nuclear division, and APC/C-Cdh1 activity itself. Multiple cyclin-CDK complexes, as well as the stoichiometric inhibitor Acm1, contribute to APC/C-Cdh1 inactivation; this redundant control is likely to promote rapid and reliable APC/C-Cdh1 inactivation immediately following the Start transition.

Disruption of the RP-MDM2-p53 pathway accelerates APC loss-induced colorectal tumorigenesis.

PubMed

Liu, S; Tackmann, N R; Yang, J; Zhang, Y

2017-03-01

Inactivation of the adenomatous polyposis coli (APC) tumor suppressor is frequently found in colorectal cancer. Loss of APC function results in deregulation of the Wnt/β-catenin signaling pathway causing overexpression of the c-MYC oncogene. In lymphoma, both p19ARF and ribosomal proteins RPL11 and RPL5 respond to c-MYC activation to induce p53. Their role in c-MYC-driven colorectal carcinogenesis is unclear, as p19ARF deletion does not accelerate APC loss-triggered intestinal tumorigenesis. To determine the contribution of the ribosomal protein (RP)-murine double minute 2 (MDM2)-p53 pathway to APC loss-induced tumorigenesis, we crossed mice bearing MDM2 C305F mutation, which disrupts RPL11- and RPL5-MDM2 binding, with Apc min/+ mice, which are prone to intestinal tumor formation. Interestingly, loss of RP-MDM2 binding significantly accelerated colorectal tumor formation while having no discernable effect on small intestinal tumor formation. Mechanistically, APC loss leads to overexpression of c-MYC, RPL11 and RPL5 in mouse colonic tumor cells irrespective of MDM2 C305F mutation. However, notable p53 stabilization and activation were observed only in Apc min/+ ;Mdm2 +/+ but not Apc min/+ ;Mdm2 C305F/C305F colon tumors. These data establish that the RP-MDM2-p53 pathway, in contrast to the p19ARF-MDM2-p53 pathway, is a critical mediator of colorectal tumorigenesis following APC loss.

Identification of Proteins Required for Precise Positioning of Apc2 in Dendrites.

PubMed

Weiner, Alexis T; Seebold, Dylan Y; Michael, Nick L; Guignet, Michelle; Feng, Chengye; Follick, Brandon; Yusko, Brandon A; Wasilko, Nathan P; Torres-Gutierrez, Pedro; Rolls, Melissa M

2018-05-04

In Drosophila neurons, uniform minus-end-out polarity in dendrites is maintained in part by kinesin-2-mediated steering of growing microtubules at branch points. Apc links the kinesin motor to growing microtubule plus ends and Apc2 recruits Apc to branch points where it functions. Because Apc2 acts to concentrate other steering proteins to branch points, we wished to understand how Apc2 is targeted. From an initial broad candidate RNAi screen, we found Miro (a mitochondrial transport protein), Ank2, Axin, spastin and Rac1 were required to position Apc2-GFP at dendrite branch points. YFP-Ank2-L8, Axin-GFP and mitochondria also localized to branch points suggesting the screen identified relevant proteins. By performing secondary screens, we found that energy production by mitochondria was key for Apc2-GFP positioning and spastin acted upstream of mitochondria. Ank2 seems to act independently from other players, except its membrane partner, Neuroglian (Nrg). Rac1 likely acts through Arp2/3 to generate branched actin to help recruit Apc2-GFP. Axin can function in a variety of wnt signaling pathways, one of which includes heterotrimeric G proteins and Frizzleds. Knockdown of Gαs, Gαo, Fz and Fz2, reduced targeting of Apc2 and Axin to branch points. Overall our data suggest that mitochondrial energy production, Nrg/Ank2, branched actin generated by Arp2/3 and Fz/G proteins/Axin function as four modules that control localization of the microtubule regulator Apc2 to its site of action in dendrite branch points. Copyright © 2018 Weiner et al.

Identification of Proteins Required for Precise Positioning of Apc2 in Dendrites

PubMed Central

Weiner, Alexis T.; Seebold, Dylan Y.; Michael, Nick L.; Guignet, Michelle; Feng, Chengye; Follick, Brandon; Yusko, Brandon A.; Wasilko, Nathan P.; Torres-Gutierrez, Pedro; Rolls, Melissa M.

2018-01-01

In Drosophila neurons, uniform minus-end-out polarity in dendrites is maintained in part by kinesin-2-mediated steering of growing microtubules at branch points. Apc links the kinesin motor to growing microtubule plus ends and Apc2 recruits Apc to branch points where it functions. Because Apc2 acts to concentrate other steering proteins to branch points, we wished to understand how Apc2 is targeted. From an initial broad candidate RNAi screen, we found Miro (a mitochondrial transport protein), Ank2, Axin, spastin and Rac1 were required to position Apc2-GFP at dendrite branch points. YFP-Ank2-L8, Axin-GFP and mitochondria also localized to branch points suggesting the screen identified relevant proteins. By performing secondary screens, we found that energy production by mitochondria was key for Apc2-GFP positioning and spastin acted upstream of mitochondria. Ank2 seems to act independently from other players, except its membrane partner, Neuroglian (Nrg). Rac1 likely acts through Arp2/3 to generate branched actin to help recruit Apc2-GFP. Axin can function in a variety of wnt signaling pathways, one of which includes heterotrimeric G proteins and Frizzleds. Knockdown of Gαs, Gαo, Fz and Fz2, reduced targeting of Apc2 and Axin to branch points. Overall our data suggest that mitochondrial energy production, Nrg/Ank2, branched actin generated by Arp2/3 and Fz/G proteins/Axin function as four modules that control localization of the microtubule regulator Apc2 to its site of action in dendrite branch points. PMID:29602811

APC loss in breast cancer leads to doxorubicin resistance via STAT3 activation.

PubMed

VanKlompenberg, Monica K; Leyden, Emily; Arnason, Anne H; Zhang, Jian-Ting; Stefanski, Casey D; Prosperi, Jenifer R

2017-11-28

Resistance to chemotherapy is one of the leading causes of death from breast cancer. We recently established that loss of Adenomatous Polyposis Coli (APC) in the Mouse Mammary Tumor Virus - Polyoma middle T (MMTV-PyMT) transgenic mouse model results in resistance to cisplatin or doxorubicin-induced apoptosis. Herein, we aim to establish the mechanism that is responsible for APC-mediated chemotherapeutic resistance. Our data demonstrate that MMTV-PyMT; Apc Min/+ cells have increased signal transducer and activator of transcription 3 (STAT3) activation. STAT3 can be constitutively activated in breast cancer, maintains the tumor initiating cell (TIC) population, and upregulates multidrug resistance protein 1 (MDR1). The activation of STAT3 in the MMTV-PyMT; Apc Min/+ model is independent of interleukin 6 (IL-6); however, enhanced EGFR expression in the MMTV-PyMT; Apc Min/+ cells may be responsible for the increased STAT3 activation. Inhibiting STAT3 with a small molecule inhibitor A69 in combination with doxorubicin, but not cisplatin, restores drug sensitivity. A69 also decreases doxorubicin enhanced MDR1 gene expression and the TIC population enhanced by loss of APC. In summary, these results have revealed the molecular mechanisms of APC loss in breast cancer that can guide future treatment plans to counteract chemotherapeutic resistance.

The Poly(ADP-ribose) Polymerase Enzyme Tankyrase Antagonizes Activity of the β-Catenin Destruction Complex through ADP-ribosylation of Axin and APC2.

PubMed

Croy, Heather E; Fuller, Caitlyn N; Giannotti, Jemma; Robinson, Paige; Foley, Andrew V A; Yamulla, Robert J; Cosgriff, Sean; Greaves, Bradford D; von Kleeck, Ryan A; An, Hyun Hyung; Powers, Catherine M; Tran, Julie K; Tocker, Aaron M; Jacob, Kimberly D; Davis, Beckley K; Roberts, David M

2016-06-10

Most colon cancer cases are initiated by truncating mutations in the tumor suppressor, adenomatous polyposis coli (APC). APC is a critical negative regulator of the Wnt signaling pathway that participates in a multi-protein "destruction complex" to target the key effector protein β-catenin for ubiquitin-mediated proteolysis. Prior work has established that the poly(ADP-ribose) polymerase (PARP) enzyme Tankyrase (TNKS) antagonizes destruction complex activity by promoting degradation of the scaffold protein Axin, and recent work suggests that TNKS inhibition is a promising cancer therapy. We performed a yeast two-hybrid (Y2H) screen and uncovered TNKS as a putative binding partner of Drosophila APC2, suggesting that TNKS may play multiple roles in destruction complex regulation. We find that TNKS binds a C-terminal RPQPSG motif in Drosophila APC2, and that this motif is conserved in human APC2, but not human APC1. In addition, we find that APC2 can recruit TNKS into the β-catenin destruction complex, placing the APC2/TNKS interaction at the correct intracellular location to regulate β-catenin proteolysis. We further show that TNKS directly PARylates both Drosophila Axin and APC2, but that PARylation does not globally regulate APC2 protein levels as it does for Axin. Moreover, TNKS inhibition in colon cancer cells decreases β-catenin signaling, which we find cannot be explained solely through Axin stabilization. Instead, our findings suggest that TNKS regulates destruction complex activity at the level of both Axin and APC2, providing further mechanistic insight into TNKS inhibition as a potential Wnt pathway cancer therapy. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

The APC/C Ubiquitin Ligase: From Cell Biology to Tumorigenesis

PubMed Central

Penas, Clara; Ramachandran, Vimal; Ayad, Nagi George

2011-01-01

The ubiquitin proteasome system (UPS) is required for normal cell proliferation, vertebrate development, and cancer cell transformation. The UPS consists of multiple proteins that work in concert to target a protein for degradation via the 26S proteasome. Chains of an 8.5-kDa protein called ubiquitin are attached to substrates, thus allowing recognition by the 26S proteasome. Enzymes called ubiquitin ligases or E3s mediate specific attachment to substrates. Although there are over 600 different ubiquitin ligases, the Skp1–Cullin–F-box (SCF) complexes and the anaphase promoting complex/cyclosome (APC/C) are the most studied. SCF involvement in cancer has been known for some time while APC/C’s cancer role has recently emerged. In this review we will discuss the importance of APC/C to normal cell proliferation and development, underscoring its possible contribution to transformation. We will also examine the hypothesis that modulating a specific interaction of the APC/C may be therapeutically attractive in specific cancer subtypes. Finally, given that the APC/C pathway is relatively new as a cancer target, therapeutic interventions affecting APC/C activity may be beneficial in cancers that are resistant to classical chemotherapy. PMID:22655255

Retinoic acid downregulates Rae1 leading to APC(Cdh1) activation and neuroblastoma SH-SY5Y differentiation.

PubMed

Cuende, J; Moreno, S; Bolaños, J P; Almeida, A

2008-05-22

In neuroblastoma cells, retinoic acid induces cell cycle arrest and differentiation through degradation of the F-box protein, Skp2, and stabilization of cyclin-dependent kinase inhibitor, p27. However, the mechanism responsible for retinoic acid-mediated Skp2 destabilization is unknown. Since Skp2 is degraded by anaphase-promoting complex (APC)(Cdh1), here we studied whether retinoic acid promotes differentiation of human SH-SY5Y neuroblastoma cells by modulating Cdh1. We found that retinoic acid induced the nuclear accumulation of Cdh1 that paralleled Skp2 destabilization and p27 accumulation. The mRNA and protein abundance of Rae1-a nuclear export factor that limits APC(Cdh1) activity in mitosis-decreased upon retinoic acid-induced inhibition of neuroblastoma cell proliferation. Furthermore, either Rae1 overexpression or Cdh1 inhibition promoted Skp2 accumulation, p27 destabilization and prevented retinoic acid-induced cell cycle arrest and differentiation. Conversely, inhibition of Rae1 accelerated retinoic acid-induced differentiation. Thus, retinoic acid downregulates Rae1, hence facilitating APC(Cdh1)-mediated Skp2 degradation leading to the arrest of cell cycle progression and neuroblastoma differentiation.

Phosphorylation and dephosphorylation regulate APC/CCdh1 substrate degradation

PubMed Central

Simpson-Lavy, Kobi J; Zenvirth, Drora; Brandeis, Michael

2015-01-01

The Anaphase Promoting Complex/Cyclosome (APC/C) ubiquitin ligase activated by its G1 specific adaptor protein Cdh1 is a major regulator of the cell cycle. The APC/CCdh1 mediates degradation of dozens of proteins, however, the kinetics and requirements for their degradation are largely unknown. We demonstrate that overexpression of the constitutive active CDH1m11 mutant that is not inhibited by phosphorylation results in mitotic exit in the absence of the FEAR and MEN pathways, and DNA re-replication in the absence of Cdc7 activity. This mode of mitotic exit also reveals additional requirements for APC/CCdh1 substrate degradation, which for some substrates such as Pds1 or Clb5 is dephosphorylation, but for others such as Cdc5 is phosphorylation. PMID:26252546

IL-6 Production by TLR-Activated APC Broadly Enhances Aged Cognate CD4 Helper and B Cell Antibody Responses In Vivo.

PubMed

Brahmakshatriya, Vinayak; Kuang, Yi; Devarajan, Priyadharshini; Xia, Jingya; Zhang, Wenliang; Vong, Allen Minh; Swain, Susan L

2017-04-01

Naive CD4 T cell responses, especially their ability to help B cell responses, become compromised with aging. We find that using APC pretreated ex vivo with TLR agonists, polyinosinic-polycytidylic acid and CpG, to prime naive CD4 T cells in vivo, restores their ability to expand and become germinal center T follicular helpers and enhances B cell IgG Ab production. Enhanced helper responses are dependent on IL-6 production by the activated APC. Aged naive CD4 T cells respond suboptimally to IL-6 compared with young cells, such that higher doses are required to induce comparable signaling. Preactivating APC overcomes this deficiency. Responses of young CD4 T cells are also enhanced by preactivating APC with similar effects but with only partial IL-6 dependency. Strikingly, introducing just the activated APC into aged mice significantly enhances otherwise compromised Ab production to inactivated influenza vaccine. These findings reveal a central role for the production of IL-6 by APC during initial cognate interactions in the generation of effective CD4 T cell help, which becomes greater with age. Without APC activation, aging CD4 T cell responses shift toward IL-6-independent Th1 and CD4 cytotoxic Th cell responses. Thus, strategies that specifically activate and provide Ag to APC could potentially enhance Ab-mediated protection in vaccine responses. Copyright © 2017 by The American Association of Immunologists, Inc.

APC/C Dysfunction Limits Excessive Cancer Chromosomal Instability

PubMed Central

Sansregret, Laurent; López-García, Carlos; Koch, André; McGranahan, Nicholas; Chao, William Chong Hang; Barry, David J.; Rowan, Andrew; Instrell, Rachael; Horswell, Stuart; Way, Michael; Howell, Michael; Singleton, Martin R.; Medema, René H.; Nurse, Paul; Petronczki, Mark; Swanton, Charles

2017-01-01

Intercellular heterogeneity, exacerbated by chromosomal instability (CIN), fosters tumor heterogeneity and drug resistance. However, extreme CIN correlates with improved cancer outcome, suggesting that karyotypic diversity required to adapt to selection pressures might be balanced in tumors against the risk of excessive instability. Here, we used a functional genomics screen, genome editing, and pharmacologic approaches to identify CIN-survival factors in diploid cells. We find partial anaphase-promoting complex/cyclosome (APC/C) dysfunction lengthens mitosis, suppresses pharmacologically induced chromosome segregation errors, and reduces naturally occurring lagging chromosomes in cancer cell lines or following tetraploidization. APC/C impairment caused adaptation to MPS1 inhibitors, revealing a likely resistance mechanism to therapies targeting the spindle assembly checkpoint. Finally, CRISPR-mediated introduction of cancer somatic mutations in the APC/C subunit cancer driver gene CDC27 reduces chromosome segregation errors, whereas reversal of an APC/C subunit nonsense mutation increases CIN. Subtle variations in mitotic duration, determined by APC/C activity, influence the extent of CIN, allowing cancer cells to dynamically optimize fitness during tumor evolution. Significance We report a mechanism whereby cancers balance the evolutionary advantages associated with CIN against the fitness costs caused by excessive genome instability, providing insight into the consequence of CDC27 APC/C subunit driver mutations in cancer. Lengthening of mitosis through APC/C modulation may be a common mechanism of resistance to cancer therapeutics that increase chromosome segregation errors. PMID:28069571

CD4+ T cell-mediated rejection of MHC class II-positive tumor cells is dependent on antigen secretion and indirect presentation on host APCs.

PubMed

Haabeth, Ole Audun Werner; Fauskanger, Marte; Manzke, Melanie; Lundin, Katrin U; Corthay, Alexandre; Bogen, Bjarne; Tveita, Anders Aune

2018-05-11

Tumor-specific CD4+ T cells have been shown to mediate efficient anti-tumor immune responses against cancer. Such responses can occur through direct binding to MHC class II (MHC II)-expressing tumor cells or indirectly via activation of professional antigen-presenting cells (APC) that take up and present the tumor antigen. We have previously shown that CD4+ T cells reactive against an epitope within the Ig light chain variable region of a murine B cell lymphoma can reject established tumors. Given the presence of MHC II molecules at the surface of lymphoma cells, we investigated whether MHC II-restricted antigen presentation on tumor cells alone was required for rejection. Variants of the A20 B lymphoma cell line that either secreted or intracellularly retained different versions of the tumor-specific antigen revealed that antigen secretion by the MHC II-expressing tumor cells was essential both for the priming and effector phase of CD4+ T cell-driven anti-tumor immune responses. Consistent with this, genetic ablation of MHC II in tumor cells, both in the case of B lymphoma and B16 melanoma, did not preclude rejection of tumors by tumor antigen-specific CD4+ T cells in vivo. These findings demonstrate that MHC class II expression on tumor cells themselves is not required for CD4+ T cell-mediated rejection, and that indirect display on host APC is sufficient for effective tumor elimination. These results support the importance of tumor-infiltrating APC as mediators of tumor cell killing by CD4+ T cells. Copyright ©2018, American Association for Cancer Research.

Cell painting with an engineered EPCR to augment the protein C system

PubMed Central

Bouwens, Eveline A. M.; Stavenuiter, Fabian; Mosnier, Laurent O.

2016-01-01

The protein C (PC) system conveys beneficial anticoagulant and cytoprotective effects in numerous in vivo disease models. The endothelial protein C receptor (EPCR) plays a central role in these pathways as cofactor for PC activation and by enhancing activated protein C (APC)-mediated protease-activated receptor (PAR) activation. During inflammatory disease, expression of EPCR on cell membranes is often diminished thereby limiting PC activation and APC’s effects on cells. Here a caveolae-targeting glycosylphosphatidylinositol (GPI)-anchored EPCR (EPCR-GPI) was engineered to restore EPCR’s bioavailability via “cell painting.” The painting efficiency of EPCR-GPI on EPCR-depleted endothelial cells was time- and dose-dependent. The EPCR-GPI bioavailability after painting was long lasting since EPCR surface levels reached 400% of wild-type cells after 2 hours and remained >200% for 24 hours. EPCR-GPI painting conveyed APC binding to EPCR-depleted endothelial cells where EPCR was lost due to shedding or shRNA. EPCR painting normalized PC activation on EPCR-depleted cells indicating that EPCR-GPI is functional active on painted cells. Caveolin-1 lipid rafts were enriched in EPCR after painting due to the GPI-anchor targeting caveolae. Accordingly, EPCR painting supported PAR1 and PAR3 cleavage by APC and augmented PAR1-dependent Akt phosphorylation by APC. Thus, EPCR-GPI painting achieved physiological relevant surface levels on endothelial cells, restored APC binding to EPCR-depleted cells, supported PC activation, and enhanced APC-mediated PAR cleavage and cytoprotective signaling. Therefore, EPCR-GPI provides a novel tool to restore the bioavailability and functionality of EPCR on EPCR-depleted and deficient cells. PMID:26272345

APC/C-Cdh1 coordinates neurogenesis and cortical size during development

NASA Astrophysics Data System (ADS)

Delgado-Esteban, Maria; García-Higuera, Irene; Maestre, Carolina; Moreno, Sergio; Almeida, Angeles

2013-12-01

The morphology of the adult brain is the result of a delicate balance between neural progenitor proliferation and the initiation of neurogenesis in the embryonic period. Here we assessed whether the anaphase-promoting complex/cyclosome (APC/C) cofactor, Cdh1—which regulates mitosis exit and G1-phase length in dividing cells—regulates neurogenesis in vivo. We use an embryo-restricted Cdh1 knockout mouse model and show that functional APC/C-Cdh1 ubiquitin ligase activity is required for both terminal differentiation of cortical neurons in vitro and neurogenesis in vivo. Further, genetic ablation of Cdh1 impairs the ability of APC/C to promote neurogenesis by delaying the exit of the progenitor cells from the cell cycle. This causes replicative stress and p53-mediated apoptotic death resulting in decreased number of cortical neurons and cortex size. These results demonstrate that APC/C-Cdh1 coordinates cortical neurogenesis and size, thus posing Cdh1 in the molecular pathogenesis of congenital neurodevelopmental disorders, such as microcephaly.

Synergistic inhibition of the APC/C by the removal of APC15 in HCT116 cells lacking UBE2C.

PubMed

Garvanska, Dimitriya H; Larsen, Marie Sofie Yoo; Nilsson, Jakob

2016-10-15

The spindle assembly checkpoint (SAC) inhibits the anaphase-promoting complex/cyclosome (APC/C) in response to unattached kinetochores by generating a diffusible inhibitor termed the mitotic checkpoint complex (MCC). At metaphase, rapid activation of the APC/C requires removal of the MCC, a process that has been shown to depend on the APC/C E2 enzymes, UBE2C and UBE2S. Here we investigate the in vivo role of the APC/C E2 enzymes in SAC silencing using CRISPR/Cas9 genetically engineered HCT116 UBE2C or UBE2S null cell lines. Using live cell assays, we show that UBE2C and UBE2S make a minor contribution to SAC silencing in HCT116 cells. Strikingly, in cells specifically lacking UBE2C, we observe a strong synergistic inhibition of mitotic progression when we stabilize the MCC on the APC/C by depleting APC15, potentially reflecting increased competition between the MCC and the remaining initiating E2 enzyme UBE2D. In conclusion, we provide in vivo insight into the APC/C E2 module and its interplay with SAC silencing components. © 2016. Published by The Company of Biologists Ltd.

Ubiquitination of Cdc20 by the APC occurs through an intramolecular mechanism

PubMed Central

Foe, Ian T.; Foster, Scott A.; Cheung, Stephanie K.; DeLuca, Steven Z.; Morgan, David O.; Toczyski, David P.

2012-01-01

SUMMARY Background Cells control progression through late mitosis by regulating Cdc20 and Cdh1, the two mitotic activators of the Anaphase Promoting Complex (APC). The control of Cdc20 protein levels during the cell cycle is not well understood. Results Here, we demonstrate that Cdc20 is degraded in budding yeast by multiple APC-dependent mechanisms. We find that the majority of Cdc20 turnover does not involve a second activator molecule, but instead depends on in cis Cdc20 autoubiquitination while it is bound to its activator-binding site on the APC core. Unlike in trans ubiquitination of Cdc20 substrates, the APC ubiquitinates Cdc20 independent of APC activation by Cdc20’s C-box. Cdc20 turnover by this intramolecular mechanism is cell cycle-regulated, contributing to the decline in Cdc20 levels that occurs after anaphase. Interestingly, high substrate levels in vitro significantly reduce Cdc20 autoubiquitination. Conclusion We show here that Cdc20 fluctuates through the cell cycle via a distinct form of APC-mediated ubiquitination. This in cis autoubiquitination may preferentially occur in early anaphase, following depletion of Cdc20 substrates. This suggests that distinct mechanisms are able to target Cdc20 for ubiquitination at different points during the cell cycle. PMID:22079111

The APC/C E3 Ligase Complex Activator FZR1 Restricts BRAF Oncogenic Function.

PubMed

Wan, Lixin; Chen, Ming; Cao, Juxiang; Dai, Xiangpeng; Yin, Qing; Zhang, Jinfang; Song, Su-Jung; Lu, Ying; Liu, Jing; Inuzuka, Hiroyuki; Katon, Jesse M; Berry, Kelsey; Fung, Jacqueline; Ng, Christopher; Liu, Pengda; Song, Min Sup; Xue, Lian; Bronson, Roderick T; Kirschner, Marc W; Cui, Rutao; Pandolfi, Pier Paolo; Wei, Wenyi

2017-04-01

BRAF drives tumorigenesis by coordinating the activation of the RAS/RAF/MEK/ERK oncogenic signaling cascade. However, upstream pathways governing BRAF kinase activity and protein stability remain undefined. Here, we report that in primary cells with active APC FZR1 , APC FZR1 earmarks BRAF for ubiquitination-mediated proteolysis, whereas in cancer cells with APC-free FZR1, FZR1 suppresses BRAF through disrupting BRAF dimerization. Moreover, we identified FZR1 as a direct target of ERK and CYCLIN D1/CDK4 kinases. Phosphorylation of FZR1 inhibits APC FZR1 , leading to elevation of a cohort of oncogenic APC FZR1 substrates to facilitate melanomagenesis. Importantly, CDK4 and/or BRAF/MEK inhibitors restore APC FZR1 E3 ligase activity, which might be critical for their clinical effects. Furthermore, FZR1 depletion cooperates with AKT hyperactivation to transform primary melanocytes, whereas genetic ablation of Fzr1 synergizes with Pten loss, leading to aberrant coactivation of BRAF/ERK and AKT signaling in mice. Our findings therefore reveal a reciprocal suppression mechanism between FZR1 and BRAF in controlling tumorigenesis. Significance: FZR1 inhibits BRAF oncogenic functions via both APC-dependent proteolysis and APC-independent disruption of BRAF dimers, whereas hyperactivated ERK and CDK4 reciprocally suppress APC FZR1 E3 ligase activity. Aberrancies in this newly defined signaling network might account for BRAF hyperactivation in human cancers, suggesting that targeting CYCLIN D1/CDK4, alone or in combination with BRAF/MEK inhibition, can be an effective anti-melanoma therapy. Cancer Discov; 7(4); 424-41. ©2017 AACR. See related commentary by Zhang and Bollag, p. 356 This article is highlighted in the In This Issue feature, p. 339 . ©2017 American Association for Cancer Research.

[Anterior chamber inflammation after the injection of endothelin-1 into the vitreous and the effect of an anti-prostaglandin agent].

PubMed

Shoji, N; Oshika, T; Masuda, K

1997-03-01

We measured the time course of aqueous protein concentration (APC) with a laser flare-cell meter after the injection of endothelin-1 (ET-1) into the vitreous cavity of pigmented rabbits and investigated the influence of pre- or post-treatment with an anti-prostaglandin agent on these effects of ET-1. Injection of ET-1 significantly increased APC in a dose-dependent fashion. After 10(-5)M ET-1 injection, APC reached maximum at 4 hours after treatment and returned to the normal level 24 hours after the injection. On the other hand, the 10(-4)M ET-1 model displayed a bi-phase time course, with a peak value observed at 4 approximately 8 hours and 48 hours post-treatment, and APC did not return to normal even 7 days after treatment. Treatment with anti-prostaglandin agents before and after the injection blocked APC increase completely in the 10(-5)M ET-1 model, and partially in the 10(-4)M ET-1 model. These results indicate that ET-1 effects on APC are at least partially mediated by the cyclooxygenase pathway of the arachidonic acid cascade.

Investigating the sustainability of careers in academic primary care in the United Kingdom.

PubMed

Adams, Ann; Lester, Helen; Reeve, Joanne; Roberts, Jane; Wilson, Andrew

2014-07-01

The UK Society for Academic Primary Care (SAPC) is re-examining the sustainability of careers in academic primary care (APC). The motivation for this is a number of significant changes within the context of APC since the last such investigation (SAPC, 2003). It is now timely to review the current situation. As a first phase, semi-structured interviews were undertaken with 15 SAPC members from different disciplines and career stages. Findings show that lack of clarity about APC career pathways persist, but important factors linked with sustainability were identified at individual and organisational levels. These include being proactive, developing resilience, mentorship and a positive organisational culture with a strong shared vision about why APC is important. FURTHER RESEARCH: Sustainability is undermined by funding difficulties, lack of integration of members of different APC disciplines, leading to disparities in career progression and lack of clarity about what APC is. Phase 2 will comprise a UK-wide survey.

Human heat shock protein 70 enhances tumor antigen presentation through complex formation and intracellular antigen delivery without innate immune signaling.

PubMed

Bendz, Henriette; Ruhland, Sibylle C; Pandya, Maya J; Hainzl, Otmar; Riegelsberger, Stefan; Braüchle, Christoph; Mayer, Matthias P; Buchner, Johannes; Issels, Rolf D; Noessner, Elfriede

2007-10-26

Heat shock proteins (HSPs) have shown promise for the optimization of protein-based vaccines because they can transfer exogenous antigens to dendritic cells and at the same time induce their maturation. Great care must be exercised in interpretating HSP-driven studies, as by-products linked to the recombinant generation of these proteins have been shown to mediate immunological effects. We generated highly purified human recombinant Hsp70 and demonstrated that it strongly enhances the cross-presentation of exogenous antigens resulting in better antigen-specific T cell stimulation. Augmentation of T cell stimulation was a direct function of the degree of complex formation between Hsp70 and peptides and correlated with improved antigen delivery to endosomal compartments. The Hsp70 activity was independent of TAP proteins and was not inhibited by exotoxin A or endosomal acidification. Consequently, Hsp70 enhanced cross-presentation of various antigenic sequences, even when they required different post-uptake processing and trafficking, as exemplified by the tumor antigens tyrosinase and Melan-A/MART-1. Furthermore, Hsp70 enhanced cross-presentation by different antigen-presenting cells (APCs), including dendritic cells and B cells. Importantly, enhanced cross-presentation and antigen-specific T cell activation were observed in the absence of innate signals transmitted by Hsp70. As Hsp70 supports the cross-presentation of different antigens and APCs and is inert to APC function, it may show efficacy in various settings of immune modulation, including induction of antigen-specific immunity or tolerance.

APC/C Dysfunction Limits Excessive Cancer Chromosomal Instability.

PubMed

Sansregret, Laurent; Patterson, James O; Dewhurst, Sally; López-García, Carlos; Koch, André; McGranahan, Nicholas; Chao, William Chong Hang; Barry, David J; Rowan, Andrew; Instrell, Rachael; Horswell, Stuart; Way, Michael; Howell, Michael; Singleton, Martin R; Medema, René H; Nurse, Paul; Petronczki, Mark; Swanton, Charles

2017-02-01

Intercellular heterogeneity, exacerbated by chromosomal instability (CIN), fosters tumor heterogeneity and drug resistance. However, extreme CIN correlates with improved cancer outcome, suggesting that karyotypic diversity required to adapt to selection pressures might be balanced in tumors against the risk of excessive instability. Here, we used a functional genomics screen, genome editing, and pharmacologic approaches to identify CIN-survival factors in diploid cells. We find partial anaphase-promoting complex/cyclosome (APC/C) dysfunction lengthens mitosis, suppresses pharmacologically induced chromosome segregation errors, and reduces naturally occurring lagging chromosomes in cancer cell lines or following tetraploidization. APC/C impairment caused adaptation to MPS1 inhibitors, revealing a likely resistance mechanism to therapies targeting the spindle assembly checkpoint. Finally, CRISPR-mediated introduction of cancer somatic mutations in the APC/C subunit cancer driver gene CDC27 reduces chromosome segregation errors, whereas reversal of an APC/C subunit nonsense mutation increases CIN. Subtle variations in mitotic duration, determined by APC/C activity, influence the extent of CIN, allowing cancer cells to dynamically optimize fitness during tumor evolution. We report a mechanism whereby cancers balance the evolutionary advantages associated with CIN against the fitness costs caused by excessive genome instability, providing insight into the consequence of CDC27 APC/C subunit driver mutations in cancer. Lengthening of mitosis through APC/C modulation may be a common mechanism of resistance to cancer therapeutics that increase chromosome segregation errors. Cancer Discov; 7(2); 218-33. ©2017 AACR.See related commentary by Burkard and Weaver, p. 134This article is highlighted in the In This Issue feature, p. 115. ©2017 American Association for Cancer Research.

Airway structural cells regulate TLR5-mediated mucosal adjuvant activity.

PubMed

Van Maele, L; Fougeron, D; Janot, L; Didierlaurent, A; Cayet, D; Tabareau, J; Rumbo, M; Corvo-Chamaillard, S; Boulenouar, S; Jeffs, S; Vande Walle, L; Lamkanfi, M; Lemoine, Y; Erard, F; Hot, D; Hussell, T; Ryffel, B; Benecke, A G; Sirard, J-C

2014-05-01

Antigen-presenting cell (APC) activation is enhanced by vaccine adjuvants. Most vaccines are based on the assumption that adjuvant activity of Toll-like receptor (TLR) agonists depends on direct, functional activation of APCs. Here, we sought to establish whether TLR stimulation in non-hematopoietic cells contributes to flagellin's mucosal adjuvant activity. Nasal administration of flagellin enhanced T-cell-mediated immunity, and systemic and secretory antibody responses to coadministered antigens in a TLR5-dependent manner. Mucosal adjuvant activity was not affected by either abrogation of TLR5 signaling in hematopoietic cells or the presence of flagellin-specific, circulating neutralizing antibodies. We found that flagellin is rapidly degraded in conducting airways, does not translocate into lung parenchyma and stimulates an early immune response, suggesting that TLR5 signaling is regionalized. The flagellin-specific early response of lung was regulated by radioresistant cells expressing TLR5 (particularly the airway epithelial cells). Flagellin stimulated the epithelial production of a small set of mediators that included the chemokine CCL20, which is known to promote APC recruitment in mucosal tissues. Our data suggest that (i) the adjuvant activity of TLR agonists in mucosal vaccination may require TLR stimulation of structural cells and (ii) harnessing the effect of adjuvants on epithelial cells can improve mucosal vaccines.

Smad3 recruits the anaphase-promoting complex for ubiquitination and degradation of SnoN

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

Stroschein, Shannon L.; Bonni, Shirin; Wrana, Jeffrey L.

2001-09-11

Smad proteins mediate transforming growth factor-b signaling to regulate cell growth and differentiation. SnoN is an important negative regulator of TGFb signaling that functions to maintain the repressed state of TGFb target genes in the absence of ligand. Upon TGFb stimulation, Smad3 and Smad2 translocate into the nucleus and induce a rapid degradation of SnoN, allowing activation of TGFb target genes. Here we show that Smad2- or Smad3-induced degradation of SnoN requires the ubiquitin-dependent proteasome and can be mediated by the anaphase promoting complex (APC) and the UbcH5 family of ubiquitin conjugating enzymes. Smad3 and to a lesser extent, Smad2,more » interact with both the APC and SnoN, resulting in the recruitment of the APC to SnoN and subsequent ubiquitination of SnoN in a destruction box-dependent manner. In addition to the destruction box, efficient degradation of SnoN also requires the Smad3 binding site in SnoN as well as key lysine residues necessary for ubiquitin attachment. Mutation of either the Smad3 binding site or lysine residues results in stabilization of SnoN and in enhanced antagonism of TGFb signaling. Our studies elucidate an important pathway for the degradation of SnoN and reveal a novel role of the APC in regulation of TGFb signaling.« less

Loss of single immunoglobulin interlukin-1 receptor-related molecule leads to enhanced colonic polyposis in Apc(min) mice.

PubMed

Xiao, Hui; Yin, Weiguo; Khan, Mohammed A; Gulen, Muhammet F; Zhou, Hang; Sham, Ho Pan; Jacobson, Kevan; Vallance, Bruce A; Li, Xiaoxia

2010-08-01

Commensal bacteria can activate signaling by the Toll-like and interleukin-1 receptors (TLR and IL-1R) to mediate pathogenesis of inflammatory bowel diseases and colitis-associated cancer. We investigated the role of the single immunoglobulin IL-1 receptor-related (SIGIRR) molecule, a negative regulator of TLR and IL-1R signaling, as a tumor suppressor to determine whether SIGIRR controls cell-cycle progression, genetic instability, and colon tumor initiation by modulating commensal TLR signaling in the gastrointestinal tract. We analyzed adenomatous polyposis coli (Apc)min/+/Sigirr-/- mice for polyps, microadenomas, and anaphase bridge index. Commensal bacteria were depleted from mice with antibiotics. Akt, mammalian target of rapamycin (mTOR), and beta-catenin pathways were examined by immunoblotting and immunohistochemistry. Loss of heterozygosity of Apc and expression of cytokines and proinflammatory mediators were measured by nonquantitative or quantitative polymerase chain reaction. Apcmin/+/Sigirr-/- mice had increased loss of heterozygosity of Apc and microadenoma formation, resulting in spontaneous colonic polyposis, compared with Apcmin/+/Sigirr+/+ mice. The increased colonic tumorigenesis that occurred in the Apcmin/+/Sigirr-/- mice depended on the presence of commensal bacteria in the gastrointestinal tract. Cell proliferation and chromosomal instability increased in colon crypt cells of the Apcmin/+/Sigirr-/- mice. Akt, mTOR, and their substrates were hyperactivated in colon epithelium of Apcmin/+/Sigirr-/- mice in response to TLR or IL-1R ligands. Inhibition of the mTOR pathway by rapamycin reduced formation of microadenomas and polyps in the Apcmin/+/Sigirr-/- mice. SIGIRR acts as a tumor suppressor in the colon by inhibiting TLR-induced, mTOR-mediated cell-cycle progression and genetic instability. Copyright (c) 2010 AGA Institute. Published by Elsevier Inc. All rights reserved.

Quantal concept of T-cell activation: adhesion domains as immunological synapses

NASA Astrophysics Data System (ADS)

Sackmann, Erich

2011-06-01

Adhesion micro-domains (ADs) formed during encounters of lymphocytes with antigen-presenting cells (APC) mediate the genetic expression of quanta of cytokines interleukin-2 (IL-2). The IL-2-induced activation of IL-2 receptors promotes the stepwise progression of the T-cells through the cell cycle, hence their name, immunological synapses. The ADs form short-lived reaction centres controlling the recruitment of activators of the biochemical pathway (the kinases Lck and ZAP) while preventing the access of inhibitors (phosphatase CD45) through steric repulsion forces. CD45 acts as the generator of adhesion domains and, through its role as a spacer protein, also as the promoter of the reaction. In a second phase of T-cell-APC encounters, long-lived global reaction spaces (called supramolecular activation complexes (SMAC)) form by talin-mediated binding of the T-cell integrin (LFA-1) to the counter-receptor ICAM-1, resulting in the formation of ring-like tight adhesion zones (peripheral SMAC). The ADs move to the centre of the intercellular adhesion zone forming the central SMAC, which serve in the recycling of the AD. We propose that cell stimulation is triggered by integrating the effect evoked by the short-lived adhesion domains. Similar global reaction platforms are formed by killer cells to destruct APC. We present a testable mechanical model showing that global reaction spaces (SMAC or dome-like contacts between cytotoxic cells and APC) form by self-organization through delayed activation of the integrin-binding affinity and stabilization of the adhesion zones by F-actin recruitment. The mechanical stability and the polarization of the adhering T-cells are mediated by microtubule-actin cross-talk.

Cyclooxygenase-2-issued prostaglandin e(2) enhances the production of endogenous IL-10, which down-regulates dendritic cell functions.

PubMed

Harizi, Hedi; Juzan, Monique; Pitard, Vincent; Moreau, Jean-François; Gualde, Norbert

2002-03-01

PGE(2) is a well-known immunomodulator produced in the immune response by APCs, such as dendritic cells (DCs), the most potent APC of the immune system. We investigated the PGE(2) biosynthetic capacity of bone marrow-derived DC (BM-DC) and the effects of PG on the APC. We observed that BM-DC produce PGE(2) and other proinflammatory mediators, such as leukotriene B(4) and NO, after LPS exposure. Constitutively present in BM-DC, cyclooxygenase (COX)-1 did not contribute significantly to the total pool of PGE(2) compared with the LPS-induced COX-2-produced PGE(2). Treatment of BM-DC with exogenous PGE(2) induced the production of large amounts of IL-10 and less IL-12p70. In addition, selective inhibition of COX-2, but not COX-1, was followed by significant decrements in PGE(2) and IL-10, a concomitant restoration of IL-12 production, and an enhancement of DC stimulatory potential. In contrast, we found no demonstrable role for leukotriene B(4) or NO. In view of the potential of PGE(2) to stimulate IL-10, we examined the possibility that the suppressive effect of PGE(2) is mediated via IL-10. We found that exogenous IL-10 inhibits IL-12p70 production in the presence of NS-398, a COX-2 selective inhibitor, while the inhibitory effects of PGE(2) were totally reversed by anti-IL-10. We conclude that COX-2-mediated PGE(2) up-regulates IL-10, which down-regulates IL-12 production and the APC function of BM-DC.

Structures of the APC–ARM domain in complexes with discrete Amer1/WTX fragments reveal that it uses a consensus mode to recognize its binding partners

PubMed Central

Zhang, Zhenyi; Akyildiz, Senem; Xiao, Yafei; Gai, Zhongchao; An, Ying; Behrens, Jürgen; Wu, Geng

2015-01-01

The tumor suppressor APC employs its conserved armadillo repeat (ARM) domain to recognize many of its binding partners, including Amer1/WTX, which is mutated in Wilms' tumor and bone overgrowth syndrome. The APC–Amer1 complex has important roles in regulating Wnt signaling and cell adhesion. Three sites A1, A2, and A3 of Amer1 have been reported to mediate its interaction with APC-ARM. In this study, crystal structures of APC–ARM in complexes with Amer1-A1, -A2, and -A4, which is newly identified in this work, were determined. Combined with our GST pull-down, yeast two-hybrid, and isothermal titration calorimetry (ITC) assay results using mutants of APC and Amer1 interface residues, our structures demonstrate that Amer1-A1, -A2, and -A4, as well as other APC-binding proteins such as Asef and Sam68, all employ a common recognition pattern to associate with APC–ARM. In contrast, Amer1-A3 binds to the C-terminal side of APC–ARM through a bipartite interaction mode. Composite mutations on either APC or Amer1 disrupting all four interfaces abrogated their association in cultured cells and impaired the membrane recruitment of APC by Amer1. Our study thus comprehensively elucidated the recognition mechanism between APC and Amer1, and revealed a consensus recognition sequence employed by various APC–ARM binding partners. PMID:27462415

Polo boxes and Cut23 (Apc8) mediate an interaction between polo kinase and the anaphase-promoting complex for fission yeast mitosis

PubMed Central

May, Karen M.; Reynolds, Nicola; Cullen, C. Fiona; Yanagida, Mitsuhiro; Ohkura, Hiroyuki

2002-01-01

The fission yeast plo1 + gene encodes a polo-like kinase, a member of a conserved family of kinases which play multiple roles during the cell cycle. We show that Plo1 kinase physically interacts with the anaphase-promoting complex (APC)/cyclosome through the noncatalytic domain of Plo1 and the tetratricopeptide repeat domain of the subunit, Cut23. A new cut23 mutation, which specifically disrupts the interaction with Plo1, results in a metaphase arrest. This arrest can be rescued by high expression of Plo1 kinase. We suggest that this physical interaction is crucial for mitotic progression by targeting polo kinase activity toward the APC. PMID:11777938

Acquired activated protein C resistance associated with anti-protein S antibody as a strong risk factor for DVT in non-SLE patients.

PubMed

Nojima, Junzo; Kuratsune, Hirohiko; Suehisa, Etsuji; Kawasaki, Tomio; Machii, Takashi; Kitani, Teruo; Iwatani, Yoshinori; Kanakura, Yuzuru

2002-11-01

Anti-phospholipid (aPL) antibodies (Abs) are well known to be associated with thromboembolic events in patients with systemic lupus erythematosus (SLE). However, the clinical relevance of a PL Abs in patients without SLE (non-SLE) who have venous thromboembolism remains unclear. We evaluated 143 non-SLE patients with a first episode of clinically suspected deep vein thrombosis (DVT) by using objective tests for diagnosing DVT and laboratory tests including the activated protein C resistance (APC-R) test, the factor V Leiden test, and various aPL Abs. The prevalence of acquired APC-R, in which case there was no factor V Leiden mutation, was significantly higher in patients with DVT (15/58 cases, 25.9%, p < 0.0001) than in those without DVT (3/80 cases, 3.7%), and confirmed that acquired APC-R was a strong risk factor for DVT (odds ratio [OR], 8.95; 95% confidence intervals [CI], 2.45-32.7; p < 0.001). Multivariate logistic analysis revealed that the presence of LA, aCL, anti-beta2-glycoprotein I, anti-prothrombin and anti-protein C Abs was not reliable as a risk factor for DVT in non-SLE patients, and that the presence of anti-protein S Abs was the most significant risk factor for DVT (OR, 5.88; 95% CI, 1.96-17.7; p < 0.002). Furthermore, the presence of anti-protein S Abs was strongly associated with acquired APC-R (OR, 57.8; 95% CI, 8.53-391; p < 0.0001). These results suggest that acquired APC-R may reflect functional interference by anti-protein S Abs of the protein C pathway, which action may represent an important mechanism for the development DVT in non-SLE patients.

Focal Adhesion Kinase Is Required for Intestinal Regeneration and Tumorigenesis Downstream of Wnt/c-Myc Signaling

PubMed Central

Ashton, Gabrielle H.; Morton, Jennifer P.; Myant, Kevin; Phesse, Toby J.; Ridgway, Rachel A.; Marsh, Victoria; Wilkins, Julie A.; Athineos, Dimitris; Muncan, Vanesa; Kemp, Richard; Neufeld, Kristi; Clevers, Hans; Brunton, Valerie; Winton, Douglas J.; Wang, Xiaoyan; Sears, Rosalie C.; Clarke, Alan R.; Frame, Margaret C.; Sansom, Owen J.

2012-01-01

SUMMARY The intestinal epithelium has a remarkable capacity to regenerate after injury and DNA damage. Here, we show that the integrin effector protein Focal Adhesion Kinase (FAK) is dispensable for normal intestinal homeostasis and DNA damage signaling, but is essential for intestinal regeneration following DNA damage. Given Wnt/c-Myc signaling is activated following intestinal regeneration, we investigated the functional importance of FAK following deletion of the Apc tumor suppressor protein within the intestinal epithelium. Following Apc loss, FAK expression increased in a c-Myc-dependent manner. Codeletion of Apc and Fak strongly reduced proliferation normally induced following Apc loss, and this was associated with reduced levels of phospho-Akt and suppression of intestinal tumorigenesis in Apc heterozygous mice. Thus, FAK is required downstream of Wnt Signaling, for Akt/mTOR activation, intestinal regeneration, and tumorigenesis. Importantly, this work suggests that FAK inhibitors may suppress tumorigenesis in patients at high risk of developing colorectal cancer. PMID:20708588

Relationship of cerebral blood flow to aortic-to-pulmonary collateral/shunt flow in single ventricles

PubMed Central

Fogel, Mark A; Li, Christine; Wilson, Felice; Pawlowski, Tom; Nicolson, Susan C; Montenegro, Lisa M; Berenstein, Laura Diaz; Spray, Thomas L; Gaynor, J William; Fuller, Stephanie; Keller, Marc S; Harris, Matthew A; Whitehead, Kevin K; Clancy, Robert; Elci, Okan; Bethel, Jim; Vossough, Arastoo; Licht, Daniel J

2016-01-01

Objective Patients with single ventricle can develop aortic-to-pulmonary collaterals (APCs). Along with systemic-to-pulmonary artery shunts, these structures represent a direct pathway from systemic to pulmonary circulations, and may limit cerebral blood flow (CBF). This study investigated the relationship between CBF and APC flow on room air and in hypercarbia, which increases CBF in patients with single ventricle. Methods 106 consecutive patients with single ventricle underwent 118 cardiac magnetic resonance (CMR) scans in this cross-sectional study; 34 prior to bidirectional Glenn (BDG) (0.50±0.30 years old), 50 prior to Fontan (3.19±1.03 years old) and 34 3–9 months after Fontan (3.98±1.39 years old). Velocity mapping measured flows in the aorta, cavae and jugular veins. Analysis of variance (ANOVA) and multiple linear regression were used. Significance was p<0.05. Results A strong inverse correlation was noted between CBF and APC/shunt both on room air and with hypercarbia whether CBF was indexed to aortic flow or body surface area, independent of age, cardiopulmonary bypass time, Po2 and Pco2 (R=−0.67–−0.70 for all patients on room air, p<0.01 and R=−0.49–−0.90 in hypercarbia, p<0.01). Correlations were not different between surgical stages. CBF was lower, and APCs/shunt flow was higher prior to BDG than in other stages. Conclusions There is a strong inverse relationship between CBF and APC/shunt flow in patients with single ventricle throughout surgical reconstruction on room air and in hypercarbia independent of other factors. We speculate that APC/shunt flow may have a negative impact on cerebral development and neurodevelopmental outcome. Interventions on APC may modify CBF, holding out the prospect for improving neurodevelopmental trajectory. Trial Registration Number NCT02135081. PMID:26048877

Relationship of cerebral blood flow to aortic-to-pulmonary collateral/shunt flow in single ventricles.

PubMed

Fogel, Mark A; Li, Christine; Wilson, Felice; Pawlowski, Tom; Nicolson, Susan C; Montenegro, Lisa M; Diaz Berenstein, Laura; Spray, Thomas L; Gaynor, J William; Fuller, Stephanie; Keller, Marc S; Harris, Matthew A; Whitehead, Kevin K; Clancy, Robert; Elci, Okan; Bethel, Jim; Vossough, Arastoo; Licht, Daniel J

2015-08-01

Patients with single ventricle can develop aortic-to-pulmonary collaterals (APCs). Along with systemic-to-pulmonary artery shunts, these structures represent a direct pathway from systemic to pulmonary circulations, and may limit cerebral blood flow (CBF). This study investigated the relationship between CBF and APC flow on room air and in hypercarbia, which increases CBF in patients with single ventricle. 106 consecutive patients with single ventricle underwent 118 cardiac magnetic resonance (CMR) scans in this cross-sectional study; 34 prior to bidirectional Glenn (BDG) (0.50±0.30 years old), 50 prior to Fontan (3.19±1.03 years old) and 34 3-9 months after Fontan (3.98±1.39 years old). Velocity mapping measured flows in the aorta, cavae and jugular veins. Analysis of variance (ANOVA) and multiple linear regression were used. Significance was p<0.05. A strong inverse correlation was noted between CBF and APC/shunt both on room air and with hypercarbia whether CBF was indexed to aortic flow or body surface area, independent of age, cardiopulmonary bypass time, Po2 and Pco2 (R=-0.67--0.70 for all patients on room air, p<0.01 and R=-0.49--0.90 in hypercarbia, p<0.01). Correlations were not different between surgical stages. CBF was lower, and APCs/shunt flow was higher prior to BDG than in other stages. There is a strong inverse relationship between CBF and APC/shunt flow in patients with single ventricle throughout surgical reconstruction on room air and in hypercarbia independent of other factors. We speculate that APC/shunt flow may have a negative impact on cerebral development and neurodevelopmental outcome. Interventions on APC may modify CBF, holding out the prospect for improving neurodevelopmental trajectory. NCT02135081. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Discovery of candidate KEN-box motifs using cell cycle keyword enrichment combined with native disorder prediction and motif conservation.

PubMed

Michael, Sushama; Travé, Gilles; Ramu, Chenna; Chica, Claudia; Gibson, Toby J

2008-02-15

KEN-box-mediated target selection is one of the mechanisms used in the proteasomal destruction of mitotic cell cycle proteins via the APC/C complex. While annotating the Eukaryotic Linear Motif resource (ELM, http://elm.eu.org/), we found that KEN motifs were significantly enriched in human protein entries with cell cycle keywords in the UniProt/Swiss-Prot database-implying that KEN-boxes might be more common than reported. Matches to short linear motifs in protein database searches are not, per se, significant. KEN-box enrichment with cell cycle Gene Ontology terms suggests that collectively these motifs are functional but does not prove that any given instance is so. Candidates were surveyed for native disorder prediction using GlobPlot and IUPred and for motif conservation in homologues. Among >25 strong new candidates, the most notable are human HIPK2, CHFR, CDC27, Dab2, Upf2, kinesin Eg5, DNA Topoisomerase 1 and yeast Cdc5 and Swi5. A similar number of weaker candidates were present. These proteins have yet to be tested for APC/C targeted destruction, providing potential new avenues of research.

The Pleiotropic Phenotype of Apc Mutations in the Mouse: Allele Specificity and Effects of the Genetic Background

PubMed Central

Halberg, Richard B.; Chen, Xiaodi; Amos-Landgraf, James M.; White, Alanna; Rasmussen, Kristin; Clipson, Linda; Pasch, Cheri; Sullivan, Ruth; Pitot, Henry C.; Dove, William F.

2008-01-01

Familial adenomatous polyposis (FAP) is a human cancer syndrome characterized by the development of hundreds to thousands of colonic polyps and extracolonic lesions including desmoid fibromas, osteomas, epidermoid cysts, and congenital hypertrophy of the pigmented retinal epithelium. Afflicted individuals are heterozygous for mutations in the APC gene. Detailed investigations of mice heterozygous for mutations in the ortholog Apc have shown that other genetic factors strongly influence the phenotype. Here we report qualitative and quantitative modifications of the phenotype of Apc mutants as a function of three genetic variables: Apc allele, p53 allele, and genetic background. We have found major differences between the Apc alleles Min and 1638N in multiplicity and regionality of intestinal tumors, as well as in incidence of extracolonic lesions. By contrast, Min mice homozygous for either of two different knockout alleles of p53 show similar phenotypic effects. These studies illustrate the classic principle that functional genetics is enriched by assessing penetrance and expressivity with allelic series. The mouse permits study of an allelic gene series on multiple genetic backgrounds, thereby leading to a better understanding of gene action in a range of biological processes. PMID:18723878

The pleiotropic phenotype of Apc mutations in the mouse: allele specificity and effects of the genetic background.

PubMed

Halberg, Richard B; Chen, Xiaodi; Amos-Landgraf, James M; White, Alanna; Rasmussen, Kristin; Clipson, Linda; Pasch, Cheri; Sullivan, Ruth; Pitot, Henry C; Dove, William F

2008-09-01

Familial adenomatous polyposis (FAP) is a human cancer syndrome characterized by the development of hundreds to thousands of colonic polyps and extracolonic lesions including desmoid fibromas, osteomas, epidermoid cysts, and congenital hypertrophy of the pigmented retinal epithelium. Afflicted individuals are heterozygous for mutations in the APC gene. Detailed investigations of mice heterozygous for mutations in the ortholog Apc have shown that other genetic factors strongly influence the phenotype. Here we report qualitative and quantitative modifications of the phenotype of Apc mutants as a function of three genetic variables: Apc allele, p53 allele, and genetic background. We have found major differences between the Apc alleles Min and 1638N in multiplicity and regionality of intestinal tumors, as well as in incidence of extracolonic lesions. By contrast, Min mice homozygous for either of two different knockout alleles of p53 show similar phenotypic effects. These studies illustrate the classic principle that functional genetics is enriched by assessing penetrance and expressivity with allelic series. The mouse permits study of an allelic gene series on multiple genetic backgrounds, thereby leading to a better understanding of gene action in a range of biological processes.

Pivotal role of PGE2 and IL-10 in the cross-regulation of dendritic cell-derived inflammatory mediators.

PubMed

Harizi, Hedi; Gualde, Norbert

2006-08-01

Exposure to pathogens induces antigen-presenting cells (APC) such as macrophages and dendritic cells (DC) to produce various endogenous mediators, including arachidonic acid (AA)-derived eicosanoids, cytokines, and nitric oxide (NO). Many secreted products of activated APC can act by themselves in an autocrine manner and modulate their function. Moreover, the cross-interaction between endogenous bioactive molecules regulates the function of professional APC with important consequences for their ability to activate and sustain immune and inflammatory responses, and to regulate immune homeostasis. Although neglected for many years when compared to their role in cardiovascular homeostasis, cancer and inflammation, the importance of eicosanoids in immunology is becoming more defined. The role of prostaglandin (PG) E2 (PGE2), one of the best known and most well studied eicosanoids, is of particular interest. It modulates the activities of professional DC by acting on their differentiation, maturation and their ability to secrete cytokines. Uniquely among haematopoietic cytokines, interleukin-10 (IL-10) is a pleiotropic molecule that displays both immunostimulatory and immunoregulatory activities. IL-10 has attached much attention because of its anti-inflammatory properties. It modulates expression of cytokines, soluble mediators and cell surface molecules by cells of myeloid origin, particularly macrophages and DC. We previously reported that PGE2 is a potent inducer of IL-10 in bone marrow-derived DC (BM-DC), and PGE2-induced IL-10 is a key regulator of the BM-DC pro-inflammatory phenotype. BM-DC may be considered as an important model to study complex interactions between endogenous mediators, and autocrine IL-10 plays a pivotal role in the crossregulation of AA-derived lipid mediators, cytokines, and NO, with critical effects on immune and inflammatory responses.

Coagulation under flow: the influence of flow-mediated transport on the initiation and inhibition of coagulation.

PubMed

Fogelson, Aaron L; Tania, Nessy

2005-01-01

A mathematical model of intravascular coagulation is presented; it encompasses the biochemistry of the tissue factor pathway, platelet activation and deposition on the subendothelium, and flow- and diffusion-mediated transport of coagulation proteins and platelets. Simulation experiments carried out with the model indicate the predominant role played by the physical processes of platelet deposition and flow-mediated removal of enzymes in inhibiting coagulation in the vicinity of vascular injury. Sufficiently rapid production of factors IXa and Xa by the TF:VIIa complex can overcome this inhibition and lead to formation of significant amounts of the tenase complex on the surface of activated platelets and, as a consequence, to substantial thrombin production. Chemical inhibitors are seen to play almost no (TFPI) or little (AT-III and APC) role in determining whether substantial thrombin production will occur. The role of APC is limited by the necessity for diffusion of thrombin from the site of injury to nearby endothelial cells to form the thrombomodulin-thrombin complex and for diffusion in the reverse direction of the APC made by this complex. TFPI plays an insignificant part in inhibiting the TF:VIIa complex under the conditions studied whether its action involves sequential binding of TFPI to Xa and then TFPI:Xa to TF:VIIa, or direct binding of TFPI to Xa already bound to the TF:VIIa complex. Copyright 2005 S. Karger AG, Basel.

Mouse model of proximal colon-specific tumorigenesis driven by microsatellite instability-induced Cre-mediated inactivation of Apc and activation of Kras.

PubMed

Kawaguchi, Yasuo; Hinoi, Takao; Saito, Yasufumi; Adachi, Tomohiro; Miguchi, Masashi; Niitsu, Hiroaki; Sasada, Tatsunari; Shimomura, Manabu; Egi, Hiroyuki; Oka, Shiro; Tanaka, Shinji; Chayama, Kazuaki; Sentani, Kazuhiro; Oue, Naohide; Yasui, Wataru; Ohdan, Hideki

2016-05-01

KRAS gene mutations are found in 40-50% of colorectal cancer cases, but their functional contribution is not fully understood. To address this issue, we generated genetically engineered mice with colon tumors expressing an oncogenic Kras(G12D) allele in the context of the Adenomatous polyposis coli (Apc) deficiency to compare them to tumors harboring Apc deficiency alone. CDX2P9.5-G22Cre (referred to as G22Cre) mice showing inducible Cre recombinase transgene expression in the proximal colon controlled under the CDX2 gene promoter were intercrossed with Apc (flox/flox) mice and LSL-Kras (G12D) mice carrying loxP-flanked Apc and Lox-Stop-Lox oncogenic Kras(G12D) alleles, respectively, to generate G22Cre; Apc(flox/flox); Kras(G12D) and G22Cre; Apc(flox/flox); KrasWT mice. Gene expression profiles of the tumors were analyzed using high-density oligonucleotide arrays. Morphologically, minimal difference in proximal colon tumor was observed between the two mouse models. Consistent with previous findings in vitro, Glut1 transcript and protein expression was up-regulated in the tumors of G22Cre;Apc (flox/flox) ; Kras(G12D) mice. Immunohistochemical staining analysis revealed that GLUT1 protein expression correlated with KRAS mutations in human colorectal cancer. Microarray analysis identified 11 candidate genes upregulated more than fivefold and quantitative PCR analysis confirmed that Aqp8, Ttr, Qpct, and Slc26a3 genes were upregulated 3.7- to 30.2-fold in tumors with mutant Kras. These results demonstrated the validity of the G22Cre; Apc(flox/flox) ;Kras (G12D) mice as a new mouse model with oncogenic Kras activation. We believe that this model can facilitate efforts to define novel factors that contribute to the pathogenesis of human colorectal cancer with KRAS mutations.

The histone acetyltransferase component TRRAP is targeted for destruction during the cell cycle.

PubMed

Ichim, G; Mola, M; Finkbeiner, M G; Cros, M-P; Herceg, Z; Hernandez-Vargas, H

2014-01-09

Chromosomes are dynamic structures that must be reversibly condensed and unfolded to accommodate mitotic division and chromosome segregation. Histone modifications are involved in the striking chromatin reconfiguration taking place during mitosis. However, the mechanisms that regulate activity and function of histone-modifying factors as cells enter and exit mitosis are poorly understood. Here, we show that the anaphase-promoting complex or cyclosome (APC/C) is involved in the mitotic turnover of TRRAP (TRansformation/tRanscription domain-Associated Protein), a common component of histone acetyltransferase (HAT) complexes, and that the pre-mitotic degradation of TRRAP is mediated by the APC/C ubiquitin ligase activators Cdc20 and Cdh1. Ectopic expression of both Cdh1 and Cdc20 reduced the levels of coexpressed TRRAP protein and induced its ubiquitination. TRRAP overexpression or stabilization induces multiple mitotic defects, including lagging chromosomes, chromosome bridges and multipolar spindles. In addition, lack of sister chromatid cohesion and impaired chromosome condensation were found after TRRAP overexpression or stabilization. By using a truncated form of TRRAP, we show that mitotic delay is associated with a global histone H4 hyperacetylation induced by TRRAP overexpression. These results demonstrate that the chromatin modifier TRRAP is targeted for destruction in a cell cycle-dependent fashion. They also suggest that degradation of TRRAP by the APC/C is necessary for a proper condensation of chromatin and proper chromosome segregation. Chromatin compaction mediated by histone modifiers may represent a fundamental arm for APC/C orchestration of the mitotic machinery.

Rapid adhesive bonding of advanced composites and titanium

NASA Technical Reports Server (NTRS)

Stein, B. A.; Tyeryart, J. R.; Hodgest, W. T.

1985-01-01

Rapid adhesive bonding (RAB) concepts utilize a toroid induction technique to heat the adhesive bond line directly. This technique was used to bond titanium overlap shear specimens with 3 advanced thermoplastic adhesives and APC-2 (graphite/PEEK) composites with PEEK film. Bond strengths equivalent to standard heated-platen press bonds were produced with large reductions in process time. RAB produced very strong bonds in APC-2 adherend specimens; the APC-2 adherends were highly resistant to delamination. Thermal cycling did not significantly affect the shear strengths of RAB titanium bonds with polyimide adhesives. A simple ultrasonic non-destructive evaluation process was found promising for evaluating bond quality.

Copy number variation of the APC gene is associated with regulation of bone mineral density☆

PubMed Central

Chew, Shelby; Dastani, Zari; Brown, Suzanne J.; Lewis, Joshua R.; Dudbridge, Frank; Soranzo, Nicole; Surdulescu, Gabriela L.; Richards, J. Brent; Spector, Tim D.; Wilson, Scott G.

2012-01-01

Introduction Genetic studies of osteoporosis have commonly examined SNPs in candidate genes or whole genome analyses, but insertions and deletions of DNA, collectively called copy number variations (CNVs), also comprise a large amount of the genetic variability between individuals. Previously, SNPs in the APC gene have been strongly associated with femoral neck and lumbar spine volumetric bone mineral density in older men. In addition, familial adenomatous polyposis patients carrying heterozygous mutations in the APC gene have been shown to have significantly higher mean bone mineral density than age- and sex-matched controls suggesting the importance of this gene in regulating bone mineral density. We examined CNV within the APC gene region to test for association with bone mineral density. Methods DNA was extracted from venous blood, genotyped using the Human Hap610 arrays and CNV determined from the fluorescence intensity data in 2070 Caucasian men and women aged 47.0 ± 13.0 (mean ± SD) years, to assess the effects of the CNV on bone mineral density at the forearm, spine and total hip sites. Results Data for covariate adjusted bone mineral density from subjects grouped by APC CNV genotype showed significant difference (P = 0.02–0.002). Subjects with a single copy loss of APC had a 7.95%, 13.10% and 13.36% increase in bone mineral density at the forearm, spine and total hip sites respectively, compared to subjects with two copies of the APC gene. Conclusions These data support previous findings of APC regulating bone mineral density and demonstrate that a novel CNV of the APC gene is significantly associated with bone mineral density in Caucasian men and women. PMID:22884971

Interaction of the MUC1 Tumor Antigen and the Adenomatous Polyposis Coli Tumor Suppressor in Human Breast Cancer

DTIC Science & Technology

2006-03-01

catenin levels in breast cancer cells; as this is accompanied by a reduction in the amount of β-catenin that lacks GSK3β -mediated phosphorylation, the...cells. 7 seen that total β-catenin levels decrease as active β-catenin levels decline, likely due to proteasomal degradation stimulated by GSK3β ...destabilization of β-catenin after MUC1 loss occurs at least in part through the APC/ GSK3β destruction complex. We also show that another APC-dependent

Unique ζ-chain motifs mediate a direct TCR-actin linkage critical for immunological synapse formation and T-cell activation.

PubMed

Klieger, Yair; Almogi-Hazan, Osnat; Ish-Shalom, Eliran; Pato, Aviad; Pauker, Maor H; Barda-Saad, Mira; Wang, Lynn; Baniyash, Michal

2014-01-01

TCR-mediated activation induces receptor microclusters that evolve to a defined immune synapse (IS). Many studies showed that actin polymerization and remodeling, which create a scaffold critical to IS formation and stabilization, are TCR mediated. However, the mechanisms controlling simultaneous TCR and actin dynamic rearrangement in the IS are yet not fully understood. Herein, we identify two novel TCR ζ-chain motifs, mediating the TCR's direct interaction with actin and inducing actin bundling. While T cells expressing the ζ-chain mutated in these motifs lack cytoskeleton (actin) associated (cska)-TCRs, they express normal levels of non-cska and surface TCRs as cells expressing wild-type ζ-chain. However, such mutant cells are unable to display activation-dependent TCR clustering, IS formation, expression of CD25/CD69 activation markers, or produce/secrete cytokine, effects also seen in the corresponding APCs. We are the first to show a direct TCR-actin linkage, providing the missing gap linking between TCR-mediated Ag recognition, specific cytoskeleton orientation toward the T-cell-APC interacting pole and long-lived IS maintenance. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

An in vivo study of Cdh1/APC in breast cancer formation

PubMed Central

Fujita, Takeo; Liu, Weijun; Doihara, Hiroyoshi; Wan, Yong

2017-01-01

Dysregulation of the ubiquitin-proteasome system (UPS) has been implicated in several types of tumorigenesis. Our previous studies have shown the potential role of Cdh1/APC in regulating tumor formation via governing the Skp2-p27-cyclinE/CDK2 axis. In this work, we utilized a xenograft mouse breast cancer model to identify the mechanism by which Cdh1/APC potentially suppresses tumor growth in vivo. Here, we report that depletion of Cdh1 results in a significant enhancement of the breast tumor proliferation, while elevated Cdh1 leads to suppression of breast tumor growth. Analysis of breast tissue arrays has indicated that higher levels of Cdh1 are associated with normal breast epithelial tissues whereas lower Skp2 expression and elevated p27 levels are detected. Conversely, the percentage of breast cancer tissues stained positive for Cdh1 and p27 are significantly lower with higher Skp2 levels. Thus, the E3 ligase, Cdh1/APC, may inhibit breast tumor growth via regulating Skp2-p27 mediated cell cycle progression. PMID:19350629

The Giardia cell cycle progresses independently of the anaphase-promoting complex

PubMed Central

Gourguechon, Stéphane; Holt, Liam J.; Cande, W. Zacheus

2013-01-01

Summary Most cell cycle regulation research has been conducted in model organisms representing a very small part of the eukaryotic domain. The highly divergent human pathogen Giardia intestinalis is ideal for studying the conservation of eukaryotic pathways. Although Giardia has many cell cycle regulatory components, its genome lacks all anaphase-promoting complex (APC) components. In the present study, we show that a single mitotic cyclin in Giardia is essential for progression into mitosis. Strikingly, Giardia cyclin B lacks the conserved N-terminal motif required for timely degradation mediated by the APC and ubiquitin conjugation. Expression of Giardia cyclin B in fission yeast is toxic, leading to a prophase arrest, and this toxicity is suppressed by the addition of a fission yeast degradation motif. Cyclin B is degraded during mitosis in Giardia cells, but this degradation appears to be independent of the ubiquitination pathway. Other putative APC substrates, aurora and polo-like kinases, also show no evidence of ubiquitination. This is the first example of mitosis not regulated by the APC and might reflect an evolutionary ancient form of cell cycle regulation. PMID:23525017

APC/CCdh1-Rock2 pathway controls dendritic integrity and memory

PubMed Central

Bobo-Jiménez, Verónica; Delgado-Esteban, María; Angibaud, Julie; Sánchez-Morán, Irene; de la Fuente, Antonio; Yajeya, Javier; Nägerl, U. Valentin; Castillo, José; Bolaños, Juan P.

2017-01-01

Disruption of neuronal morphology contributes to the pathology of neurodegenerative disorders such as Alzheimer’s disease (AD). However, the underlying molecular mechanisms are unknown. Here, we show that postnatal deletion of Cdh1, a cofactor of the anaphase-promoting complex/cyclosome (APC/C) ubiquitin ligase in neurons [Cdh1 conditional knockout (cKO)], disrupts dendrite arborization and causes dendritic spine and synapse loss in the cortex and hippocampus, concomitant with memory impairment and neurodegeneration, in adult mice. We found that the dendrite destabilizer Rho protein kinase 2 (Rock2), which accumulates in the brain of AD patients, is an APC/CCdh1 substrate in vivo and that Rock2 protein and activity increased in the cortex and hippocampus of Cdh1 cKO mice. In these animals, inhibition of Rock activity, using the clinically approved drug fasudil, prevented dendritic network disorganization, memory loss, and neurodegeneration. Thus, APC/CCdh1-mediated degradation of Rock2 maintains the dendritic network, memory formation, and neuronal survival, suggesting that pharmacological inhibition of aberrantly accumulated Rock2 may be a suitable therapeutic strategy against neurodegeneration. PMID:28396402

Proliferating cell nuclear antigen (PCNA)-associated KIAA0101/PAF15 protein is a cell cycle-regulated anaphase-promoting complex/cyclosome substrate.

PubMed

Emanuele, Michael J; Ciccia, Alberto; Elia, Andrew E H; Elledge, Stephen J

2011-06-14

The anaphase-promoting complex/cyclosome (APC/C) is a cell cycle-regulated E3 ubiquitin ligase that controls the degradation of substrate proteins at mitotic exit and throughout the G1 phase. We have identified an APC/C substrate and cell cycle-regulated protein, KIAA0101/PAF15. PAF15 protein levels peak in the G2/M phase of the cell cycle and drop rapidly at mitotic exit in an APC/C- and KEN-box-dependent fashion. PAF15 associates with proliferating cell nuclear antigen (PCNA), and depletion of PAF15 decreases the number of cells in S phase, suggesting a role for it in cell cycle regulation. Following irradiation, PAF15 colocalized with γH2AX foci at sites of DNA damage through its interaction with PCNA. Finally, PAF15 depletion led to an increase in homologous recombination-mediated DNA repair, and overexpression caused sensitivity to UV-induced DNA damage. We conclude that PAF15 is an APC/C-regulated protein involved in both cell cycle progression and the DNA damage response.

Polarized release of T-cell-receptor-enriched microvesicles at the immunological synapse.

PubMed

Choudhuri, Kaushik; Llodrá, Jaime; Roth, Eric W; Tsai, Jones; Gordo, Susana; Wucherpfennig, Kai W; Kam, Lance C; Stokes, David L; Dustin, Michael L

2014-03-06

The recognition events that mediate adaptive cellular immunity and regulate antibody responses depend on intercellular contacts between T cells and antigen-presenting cells (APCs). T-cell signalling is initiated at these contacts when surface-expressed T-cell receptors (TCRs) recognize peptide fragments (antigens) of pathogens bound to major histocompatibility complex molecules (pMHC) on APCs. This, along with engagement of adhesion receptors, leads to the formation of a specialized junction between T cells and APCs, known as the immunological synapse, which mediates efficient delivery of effector molecules and intercellular signals across the synaptic cleft. T-cell recognition of pMHC and the adhesion ligand intercellular adhesion molecule-1 (ICAM-1) on supported planar bilayers recapitulates the domain organization of the immunological synapse, which is characterized by central accumulation of TCRs, adjacent to a secretory domain, both surrounded by an adhesive ring. Although accumulation of TCRs at the immunological synapse centre correlates with T-cell function, this domain is itself largely devoid of TCR signalling activity, and is characterized by an unexplained immobilization of TCR-pMHC complexes relative to the highly dynamic immunological synapse periphery. Here we show that centrally accumulated TCRs are located on the surface of extracellular microvesicles that bud at the immunological synapse centre. Tumour susceptibility gene 101 (TSG101) sorts TCRs for inclusion in microvesicles, whereas vacuolar protein sorting 4 (VPS4) mediates scission of microvesicles from the T-cell plasma membrane. The human immunodeficiency virus polyprotein Gag co-opts this process for budding of virus-like particles. B cells bearing cognate pMHC receive TCRs from T cells and initiate intracellular signals in response to isolated synaptic microvesicles. We conclude that the immunological synapse orchestrates TCR sorting and release in extracellular microvesicles. These microvesicles deliver transcellular signals across antigen-dependent synapses by engaging cognate pMHC on APCs.

Polarized release of T-cell-receptor-enriched microvesicles at the immunological synapse

NASA Astrophysics Data System (ADS)

Choudhuri, Kaushik; Llodrá, Jaime; Roth, Eric W.; Tsai, Jones; Gordo, Susana; Wucherpfennig, Kai W.; Kam, Lance C.; Stokes, David L.; Dustin, Michael L.

2014-03-01

The recognition events that mediate adaptive cellular immunity and regulate antibody responses depend on intercellular contacts between T cells and antigen-presenting cells (APCs). T-cell signalling is initiated at these contacts when surface-expressed T-cell receptors (TCRs) recognize peptide fragments (antigens) of pathogens bound to major histocompatibility complex molecules (pMHC) on APCs. This, along with engagement of adhesion receptors, leads to the formation of a specialized junction between T cells and APCs, known as the immunological synapse, which mediates efficient delivery of effector molecules and intercellular signals across the synaptic cleft. T-cell recognition of pMHC and the adhesion ligand intercellular adhesion molecule-1 (ICAM-1) on supported planar bilayers recapitulates the domain organization of the immunological synapse, which is characterized by central accumulation of TCRs, adjacent to a secretory domain, both surrounded by an adhesive ring. Although accumulation of TCRs at the immunological synapse centre correlates with T-cell function, this domain is itself largely devoid of TCR signalling activity, and is characterized by an unexplained immobilization of TCR-pMHC complexes relative to the highly dynamic immunological synapse periphery. Here we show that centrally accumulated TCRs are located on the surface of extracellular microvesicles that bud at the immunological synapse centre. Tumour susceptibility gene 101 (TSG101) sorts TCRs for inclusion in microvesicles, whereas vacuolar protein sorting 4 (VPS4) mediates scission of microvesicles from the T-cell plasma membrane. The human immunodeficiency virus polyprotein Gag co-opts this process for budding of virus-like particles. B cells bearing cognate pMHC receive TCRs from T cells and initiate intracellular signals in response to isolated synaptic microvesicles. We conclude that the immunological synapse orchestrates TCR sorting and release in extracellular microvesicles. These microvesicles deliver transcellular signals across antigen-dependent synapses by engaging cognate pMHC on APCs.

A Crucial Role for Host APCs in the Induction of Donor CD4+CD25+ Regulatory T Cell-Mediated Suppression of Experimental Graft-versus-Host Disease

PubMed Central

Tawara, Isao; Shlomchik, Warren D.; Jones, Angela; Zou, Weiping; Nieves, Evelyn; Liu, Chen; Toubai, Tomomi; Duran-Struuck, Raimon; Sun, Yaping; Clouthier, Shawn G.; Evers, Rebecca; Lowler, Kathleen P.; Levy, Robert B.; Reddy, Pavan

2010-01-01

Allogeneic bone marrow transplantation is an effective treatment for a number of malignant and nonmalignant diseases (Applebaum. 2001. Nature. 411: 385–389 and Copelan. 2006. N Engl J Med. 354: 1813–1826). However, the application of this therapeutic modality has been impeded by a number of confounding side effects, the most frequent and severe of which is the development of graft-versus-host disease (GVHD) (Copelan. 2006. N Engl J Med. 354: 1813–1826 and Blazar and Murphy. 2005. Philos Trans R Soc Lond B Biol Sci. 360: 1747–1767). Alloreactive donor T cells are critical for causing GVHD (Fowler. 2006. Crit Rev Oncol Hematol. 57: 225–244 and Ferrara and Reddy. 2006. Semin Hematol. 43: 3–10), whereas recent data demonstrated a significant role for the naturally occurring thymic-derived donor CD4+CD25+Foxp3+ regulatory T cells (Tregs) (Bluestone and Abbas. 2003. Nat Rev Immunol. 3: 253–257 and Shevach. 2006. Immunity. 25: 195–201) in suppressing experimental GVHD after bone marrow transplantation (Blazar and Taylor. 2005. Biol Blood Marrow Transpl. 11: 46–49 and Joffe and van Meerwijk. 2006. Semin Immunol. 18: 128–135). Host APCs are required for induction of GVHD by the conventional donor T cells. However, it is not known whether they are also obligatory for donor Treg-mediated suppression of GVHD. Using multiple clinically relevant MHC-matched and -mismatched murine models of GVHD, we investigated the role of host APCs in the suppression of GVHD by donor Tregs. We found that alloantigen expression by the host APCs is necessary and sufficient for induction of GVHD protection by donor Tregs. This requirement was independent of their effect on the maintenance of Treg numbers and the production of IL-10 or IDO by the host APCs. PMID:20810991

Intravaginal Zinc Oxide Tetrapod Nanoparticles as Novel Immunoprotective Agents against Genital Herpes.

PubMed

Antoine, Thessicar E; Hadigal, Satvik R; Yakoub, Abraam M; Mishra, Yogendra Kumar; Bhattacharya, Palash; Haddad, Christine; Valyi-Nagy, Tibor; Adelung, Rainer; Prabhakar, Bellur S; Shukla, Deepak

2016-06-01

Virtually all efforts to generate an effective protection against the life-long, recurrent genital infections caused by HSV-2 have failed. Apart from sexual transmission, the virus can also be transmitted from mothers to neonates, and it is a key facilitator of HIV coacquisition. In this article, we uncover a nanoimmunotherapy using specially designed zinc oxide tetrapod nanoparticles (ZOTEN) with engineered oxygen vacancies. We demonstrate that ZOTEN, when used intravaginally as a microbicide, is an effective suppressor of HSV-2 genital infection in female BALB/c mice. The strong HSV-2 trapping ability of ZOTEN significantly reduced the clinical signs of vaginal infection and effectively decreased animal mortality. In parallel, ZOTEN promoted the presentation of bound HSV-2 virions to mucosal APCs, enhancing T cell-mediated and Ab-mediated responses to the infection, and thereby suppressing a reinfection. We also found that ZOTEN exhibits strong adjuvant-like properties, which is highly comparable with alum, a commonly used adjuvant. Overall, to our knowledge, our study provides the very first evidence for the protective efficacy of an intravaginal microbicide/vaccine or microbivac platform against primary and secondary female genital herpes infections. Copyright © 2016 by The American Association of Immunologists, Inc.

Membrane-type matrix metalloproteinases mediate curcumin-induced cell migration in non-tumorigenic colon epithelial cells differing in Apc genotype.

PubMed

Fenton, Jenifer I; Wolff, Margaret S; Orth, Michael W; Hord, Norman G

2002-06-01

Colonic epithelial cell migration is required for normal differentiated cell function. This migratory phenotype is dependent upon wild-type adenomatous polyposis coli (Apc) expression. Non-tumorigenic murine colon epithelial cell lines with distinct Apc genotypes, i.e. young adult mouse colon (YAMC; Apc(+/+)) and immortomouse/Min colon epithelial (IMCE; Apc(Min/+) cells) were used to assess the association between the Apc genotype, cell motility and matrix metalloproteinase (MMP) activity. Cells were treated with epidermal growth factor (EGF; 1, 10 and 25 ng/ml), hepatocyte growth factor (HGF; 1, 10 and 25 ng/ml) and/or curcumin (0.1-100 microM). EGF (25 ng/ml) and HGF (25 ng/ml) induced a greater migratory response in YAMC compared with IMCE cells after 24 h (P < 0.05). Treatment with curcumin induced a greater or equivalent migratory response in IMCE than YAMC cells. When migrating cells were treated with Ilomastat (MMP inhibitor), migration was inhibited in both cell types. High concentrations of Ilomastat (25 and 50 microM) inhibited migration in both cell types, while low concentrations (10 microM) inhibited HGF-induced IMCE migration. Curcumin-induced migration was inhibited in both cell types at the highest concentration of Ilomastat (50 microM). Immuno-localization analysis of membrane type-1 (MT1)-MMP indicated that migration is associated with the redistribution of this protein from the endoplasmic reticulum to the plasma membrane. Addition of neutralizing polyclonal antibodies against MT1-MMP or a mixture of MT1, 2- and 3-MMPs demonstrated partial or complete inhibition of cell migration in both cell types, respectively. The data provide the first evidence that migration in non-tumorigenic murine colon epithelial cells is: (i) inducible by EGF and HGF in an Apc genotype-dependent manner, (ii) dependent on MT-MMP activity and (iii) inducible by curcumin in an Apc genotype-independent manner. The data suggest a potential mechanism by which curcumin may induce cells heterozygous for Apc to overcome defective cell migration, a phenotype associated with cell differentiation and apoptosis.

The early interaction of Leishmania with macrophages and dendritic cells and its influence on the host immune response.

PubMed

Liu, Dong; Uzonna, Jude E

2012-01-01

The complicated interactions between Leishmania and the host antigen-presenting cells (APCs) have fundamental effects on the final outcome of the disease. Two major APCs, macrophages and dendritic cells (DCs), play critical roles in mediating resistance and susceptibility during Leishmania infection. Macrophages are the primary resident cell for Leishmania: they phagocytose and permit parasite proliferation. However, these cells are also the major effector cells to eliminate infection. The effective clearance of parasites by macrophages depends on activation of appropriate immune response, which is usually initiated by DCs. Here, we review the early interaction of APCs with Leishmania parasites and how these interactions profoundly impact on the ensuing adaptive immune response. We also discuss how the current knowledge will allow further refinement of our understanding of the interplay between Leishmania and its hosts that leads to resistance or susceptibility.

The early interaction of Leishmania with macrophages and dendritic cells and its influence on the host immune response

PubMed Central

Liu, Dong; Uzonna, Jude E.

2012-01-01

The complicated interactions between Leishmania and the host antigen-presenting cells (APCs) have fundamental effects on the final outcome of the disease. Two major APCs, macrophages and dendritic cells (DCs), play critical roles in mediating resistance and susceptibility during Leishmania infection. Macrophages are the primary resident cell for Leishmania: they phagocytose and permit parasite proliferation. However, these cells are also the major effector cells to eliminate infection. The effective clearance of parasites by macrophages depends on activation of appropriate immune response, which is usually initiated by DCs. Here, we review the early interaction of APCs with Leishmania parasites and how these interactions profoundly impact on the ensuing adaptive immune response. We also discuss how the current knowledge will allow further refinement of our understanding of the interplay between Leishmania and its hosts that leads to resistance or susceptibility. PMID:22919674

Non-equivalent antigen presenting capabilities of dendritic cells and macrophages in generating brain-infiltrating CD8 + T cell responses.

PubMed

Malo, Courtney S; Huggins, Matthew A; Goddery, Emma N; Tolcher, Heather M A; Renner, Danielle N; Jin, Fang; Hansen, Michael J; Pease, Larry R; Pavelko, Kevin D; Johnson, Aaron J

2018-02-12

The contribution of antigen-presenting cell (APC) types in generating CD8 + T cell responses in the central nervous system (CNS) is not fully defined, limiting the development of vaccines and understanding of immune-mediated neuropathology. Here, we generate a transgenic mouse that enables cell-specific deletion of the H-2Kb MHC class I molecule. By deleting H-2K b on dendritic cells and macrophages, we compare the effect of each APC in three distinct models of neuroinflammation: picornavirus infection, experimental cerebral malaria, and a syngeneic glioma. Dendritic cells and macrophages both activate CD8 + T cell responses in response to these CNS immunological challenges. However, the extent to which each of these APCs contributes to CD8 + T cell priming varies. These findings reveal distinct functions for dendritic cells and macrophages in generating CD8 + T cell responses to neurological disease.

T-cell activation is enhanced by targeting IL-10 cytokine production in toll-like receptor-stimulated macrophages

PubMed Central

Walk, Ryan M; Elliott, Steven T; Blanco, Felix C; Snyder, Jason A; Jacobi, Ashley M; Rose, Scott D; Behlke, Mark A; Salem, Aliasger K; Vukmanovic, Stanislav; Sandler, Anthony D

2012-01-01

Toll-like receptor (TLR) agonists represent potentially useful cancer vaccine adjuvants in their ability to stimulate antigen-presenting cells (APCs) and subsequently amplify the cytotoxic T-cell response. The purpose of this study was to characterize APC responses to TLR activation and to determine the subsequent effect on lymphocyte activation. We exposed murine primary bone marrow-derived macrophages to increasing concentrations of agonists to TLRs 2, 3, 4, and 9. This resulted in a dose-dependent increase in production of not only tumor necrosis factor–alpha (TNF-α), a surrogate marker of the proinflammatory response, but also interleukin 10 (IL-10), a well-described inhibitory cytokine. Importantly, IL-10 secretion was not induced by low concentrations of TLR agonists that readily produced TNF-α. We subsequently stimulated lymphocytes with anti-CD3 antibody in the presence of media from macrophages activated with higher doses of TLR agonists and observed suppression of interferon gamma release. Use of both IL-10 knockout macrophages and IL-10 small-interfering RNA (siRNA) ablated this suppressive effect. Finally, IL-10 siRNA was successfully used to suppress CpG-induced IL-10 production in vivo. We conclude that TLR-mediated APC stimulation can induce a paradoxical inhibitory effect on T-cell activation mediated by IL-10. PMID:27471682

Mannan-decorated thiolated Eudragit microspheres for targeting antigen presenting cells via nasal vaccination.

PubMed

Li, Hui-Shan; Singh, Bijay; Park, Tae-Eun; Hong, Zhong-Shan; Kang, Sang-Kee; Cho, Chong-Su; Choi, Yun-Jaie

2015-12-01

Mucosal vaccination of protein as an antigen requires appropriate delivery or adjuvant systems to deliver antigen to mucosal immune cells efficiently and generate valid immune responses. For successful nasal immunization, the obstacles imposed by the normal process of mucociliary clearance which limits residence time of applied antigens and low antigen delivery to antigen presenting cells (APCs) in nasal associated lymphoid tissue (NALT) need to be overcome for the efficient vaccination. Here, we prepared mucoadhesive and mannan-decorated thiolated Eudragit microspheres (Man-TEM) as a nasal vaccine carrier to overcome the limitations. Mucoadhesive thiolated Eudragit (TE) were decorated with mannan for targeting mannose receptors (MR) in antigen presenting cells (APCs) to obtain efficient immune responses. The potential adjuvant ability of Man-TEM for intranasal immunization was confirmed by in vitro and in vivo experiments. In mechanistic study using APCs in vitro, we obtained that Man-TEM enhanced the receptor-mediated endocytosis by stimulating the MR receptors of APCs. The nasal vaccination of OVA-loaded Man-TEM in mice showed higher levels of serum IgG and mucosal sIgA than the soluble OVA group due to the specific recognition of MR of APCs by the mannan in the Man-TEM. These results suggest that mucoadhesive and Man-TEM may be a promising candidate for nasal vaccine delivery system to elicit systemic and mucosal immunity. Copyright © 2015 Elsevier B.V. All rights reserved.

Mechanism of Polyubiquitination by Human Anaphase-Promoting Complex: RING Repurposing for Ubiquitin Chain Assembly

DOE PAGES

Brown, Nicholas G.; Watson, Edmond R.; Weissmann, Florian; ...

2014-10-09

Polyubiquitination by E2 and E3 enzymes is a predominant mechanism regulating protein function. Some RING E3s, including anaphase-promoting complex/cyclosome (APC), catalyze polyubiquitination by sequential reactions with two different E2s. An initiating E2 ligates ubiquitin to an E3-bound substrate. Another E2 grows a polyubiquitin chain on the ubiquitin-primed substrate through poorly defined mechanisms. Here in this paper we show that human APC’s RING domain is repurposed for dual functions in polyubiquitination. The canonical RING surface activates an initiating E2-ubiquitin intermediate for substrate modification. However, APC engages and activates its specialized ubiquitin chain-elongating E2 UBE2S in ways that differ from current paradigms.more » During chain assembly, a distinct APC11 RING surface helps deliver a substrate-linked ubiquitin to accept another ubiquitin from UBE2S. Our data define mechanisms of APC/UBE2S-mediated polyubiquitination, reveal diverse functions of RING E3s and E2s, and provide a framework for understanding distinctive RING E3 features specifying ubiquitin chain elongation.« less

An orc1 allele with a mutated APC motif is female sterile with amplification defects.

PubMed

Park, So Young; Asano, Maki

2012-08-01

The origin recognition complex 1 (ORC1) is the largest subunit of the ORC, the heteromeric hexamer. ORC1 is an essential component of the pre-replicative complex (pre-RC) that licenses eukaryote DNA replication origins. The levels of ORC1 fluctuate during the mitotic cell cycle in Drosophila as well as in some human cells. Proteolysis of ORC1 occurs at the end of M phase in Drosophila, which is mediated by the anaphase-promoting complex (APC), and in late S phase in human cells by Skip-Cullin-F box (SCF). Previously we showed that proteolysis of ORC1 by APC is mediated by the ORC1 destruction box (the O-box), an APC motif conserved among species yet distinct from the D-box or KEN-box. Recently we showed that replacing the O-box with the D-box (ORC1O→D) changes the degradation profile of ORC1 during a canonical cell cycle. Here we report further characterization of the ORC1O→D allele that turned out to be a useful tool to examine the function of ORC1 in other modes of DNA replication during oogenesis. In endoreplication stages ORC1O→D does not change any DNA content profiles, consistent with our previous finding that ORC is dispensable for endoreplication. However, in amplification stage replication efficiency of ORC1O→D is drastically reduced, which resulted in amplification defects that led to thin egg shell phenotype. Taken together, our analyses show that orc1 allele newly identified is female sterile and possesses a unique feature of phenotypes that are distinct in different modes of DNA replication.

Drosophila-Cdh1 (Rap/Fzr) a regulatory subunit of APC/C is required for synaptic morphology, synaptic transmission and locomotion.

PubMed

Wise, Alexandria; Schatoff, Emma; Flores, Julian; Hua, Shao-Ying; Ueda, Atsushi; Wu, Chun-Fang; Venkatesh, Tadmiri

2013-11-01

The assembly of functional synapses requires the orchestration of the synthesis and degradation of a multitude of proteins. Protein degradation and modification by the conserved ubiquitination pathway has emerged as a key cellular regulatory mechanism during nervous system development and function (Kwabe and Brose, 2011). The anaphase promoting complex/cyclosome (APC/C) is a multi-subunit ubiquitin ligase complex primarily characterized for its role in the regulation of mitosis (Peters, 2002). In recent years, a role for APC/C in nervous system development and function has been rapidly emerging (Stegmuller and Bonni, 2005; Li et al., 2008). In the mammalian central nervous system the activator subunit, APC/C-Cdh1, has been shown to be a regulator of axon growth and dendrite morphogenesis (Konishi et al., 2004). In the Drosophila peripheral nervous system (PNS), APC2, a ligase subunit of the APC/C complex has been shown to regulate synaptic bouton size and activity (van Roessel et al., 2004). To investigate the role of APC/C-Cdh1 at the synapse we examined loss-of-function mutants of Rap/Fzr (Retina aberrant in pattern/Fizzy related), a Drosophila homolog of the mammalian Cdh1 during the development of the larval neuromuscular junction in Drosophila. Our cell biological, ultrastructural, electrophysiological, and behavioral data showed that rap/fzr loss-of-function mutations lead to changes in synaptic structure and function as well as locomotion defects. Data presented here show changes in size and morphology of synaptic boutons, and, muscle tissue organization. Electrophysiological experiments show that loss-of-function mutants exhibit increased frequency of spontaneous miniature synaptic potentials, indicating a higher rate of spontaneous synaptic vesicle fusion events. In addition, larval locomotion and peristaltic movement were also impaired. These findings suggest a role for Drosophila APC/C-Cdh1 mediated ubiquitination in regulating synaptic morphology, function and integrity of muscle structure in the peripheral nervous system. Copyright © 2013 ISDN. Published by Elsevier Ltd. All rights reserved.

GPS-ARM: Computational Analysis of the APC/C Recognition Motif by Predicting D-Boxes and KEN-Boxes

PubMed Central

Ren, Jian; Cao, Jun; Zhou, Yanhong; Yang, Qing; Xue, Yu

2012-01-01

Anaphase-promoting complex/cyclosome (APC/C), an E3 ubiquitin ligase incorporated with Cdh1 and/or Cdc20 recognizes and interacts with specific substrates, and faithfully orchestrates the proper cell cycle events by targeting proteins for proteasomal degradation. Experimental identification of APC/C substrates is largely dependent on the discovery of APC/C recognition motifs, e.g., the D-box and KEN-box. Although a number of either stringent or loosely defined motifs proposed, these motif patterns are only of limited use due to their insufficient powers of prediction. We report the development of a novel GPS-ARM software package which is useful for the prediction of D-boxes and KEN-boxes in proteins. Using experimentally identified D-boxes and KEN-boxes as the training data sets, a previously developed GPS (Group-based Prediction System) algorithm was adopted. By extensive evaluation and comparison, the GPS-ARM performance was found to be much better than the one using simple motifs. With this powerful tool, we predicted 4,841 potential D-boxes in 3,832 proteins and 1,632 potential KEN-boxes in 1,403 proteins from H. sapiens, while further statistical analysis suggested that both the D-box and KEN-box proteins are involved in a broad spectrum of biological processes beyond the cell cycle. In addition, with the co-localization information, we predicted hundreds of mitosis-specific APC/C substrates with high confidence. As the first computational tool for the prediction of APC/C-mediated degradation, GPS-ARM is a useful tool for information to be used in further experimental investigations. The GPS-ARM is freely accessible for academic researchers at: http://arm.biocuckoo.org. PMID:22479614

Dysregulated luminal bacterial antigen-specific T-cell responses and antigen-presenting cell function in HLA-B27 transgenic rats with chronic colitis

PubMed Central

Qian, Bi-Feng; Tonkonogy, Susan L; Hoentjen, Frank; Dieleman, Levinus A; Sartor, R Balfour

2005-01-01

HLA-B27/β2 microglobulin transgenic (TG) rats spontaneously develop T-cell-mediated colitis when colonized with normal commensal bacteria, but remain disease-free under germ-free conditions. We investigated regulation of in vitro T-cell responses to enteric bacterial components. Bacterial lysates prepared from the caecal contents of specific pathogen-free (SPF) rats stimulated interferon-γ (IFN-γ) production by TG but not non-TG mesenteric lymph node (MLN) cells. In contrast, essentially equivalent amounts of interleukin-10 (IL-10) were produced by TG and non-TG cells. However, when cells from MLNs of non-TG rats were cocultured with TG MLN cells, no suppression of IFN-γ production was noted. Both non-TG and TG antigen-presenting cells (APC) pulsed with caecal bacterial lysate were able to induce IFN-γ production by TG CD4+ cells, although non-TG APC were more efficient than TG APC. Interestingly, the addition of exogenous IL-10 inhibited non-TG APC but not TG APC stimulation of IFN-γ production by cocultured TG CD4+ lymphocytes. Conversely, in the presence of exogenous IFN-γ, production of IL-10 was significantly lower in the supernatants of TG compared to non-TG APC cultures. We conclude that commensal luminal bacterial components induce exaggerated in vitro IFN-γ responses in HLA-B27 TG T cells, which may in turn inhibit the production of regulatory molecules, such as IL-10. Alterations in the production of IFN-γ, and in responses to this cytokine, as well as possible resistance of TG cells to suppressive regulation could together contribute to the development of chronic colitis in TG rats. PMID:16108823

Prediction and Testing of Biological Networks Underlying Intestinal Cancer

PubMed Central

Mariadason, John M.; Wang, Donghai; Augenlicht, Leonard H.; Chance, Mark R.

2010-01-01

Colorectal cancer progresses through an accumulation of somatic mutations, some of which reside in so-called “driver” genes that provide a growth advantage to the tumor. To identify points of intersection between driver gene pathways, we implemented a network analysis framework using protein interactions to predict likely connections – both precedented and novel – between key driver genes in cancer. We applied the framework to find significant connections between two genes, Apc and Cdkn1a (p21), known to be synergistic in tumorigenesis in mouse models. We then assessed the functional coherence of the resulting Apc-Cdkn1a network by engineering in vivo single node perturbations of the network: mouse models mutated individually at Apc (Apc1638N+/−) or Cdkn1a (Cdkn1a−/−), followed by measurements of protein and gene expression changes in intestinal epithelial tissue. We hypothesized that if the predicted network is biologically coherent (functional), then the predicted nodes should associate more specifically with dysregulated genes and proteins than stochastically selected genes and proteins. The predicted Apc-Cdkn1a network was significantly perturbed at the mRNA-level by both single gene knockouts, and the predictions were also strongly supported based on physical proximity and mRNA coexpression of proteomic targets. These results support the functional coherence of the proposed Apc-Cdkn1a network and also demonstrate how network-based predictions can be statistically tested using high-throughput biological data. PMID:20824133

Spatiotemporal Regulation of the Anaphase-Promoting Complex in Mitosis

PubMed Central

Sivakumar, Sushama; Gorbsky, Gary J

2015-01-01

The appropriate timing of events that lead to chromosome segregation during mitosis and cytokinesis is essential to prevent aneuploidy, and defects in these processes can contribute to tumorigenesis. Key mitotic regulators are controlled through ubiquitylation and proteasome-mediated degradation. The Anaphase-Promoting Complex or Cyclosome (APC/C) is an E3 ubiquitin ligase that has a crucial function in the regulation of the mitotic cell cycle, particularly at the onset of anaphase and during mitotic exit. Co-activator proteins, inhibitor proteins, protein kinases and phosphatases interact with the APC/C to temporally and spatially control its activity and thus ensure accurate timing of mitotic events. PMID:25604195

A targeted and adjuvanted nanocarrier lowers the effective dose of liposomal amphotericin B and enhances adaptive immunity in murine cutaneous leishmaniasis.

PubMed

Daftarian, Pirouz M; Stone, Geoffrey W; Kovalski, Leticia; Kumar, Manoj; Vosoughi, Aram; Urbieta, Maitee; Blackwelder, Pat; Dikici, Emre; Serafini, Paolo; Duffort, Stephanie; Boodoo, Richard; Rodríguez-Cortés, Alhelí; Lemmon, Vance; Deo, Sapna; Alberola, Jordi; Perez, Victor L; Daunert, Sylvia; Ager, Arba L

2013-12-01

Amphotericin B (AmB), the most effective drug against leishmaniasis, has serious toxicity. As Leishmania species are obligate intracellular parasites of antigen presenting cells (APC), an immunopotentiating APC-specific AmB nanocarrier would be ideally suited to reduce the drug dosage and regimen requirements in leishmaniasis treatment. Here, we report a nanocarrier that results in effective treatment shortening of cutaneous leishmaniasis in a mouse model, while also enhancing L. major specific T-cell immune responses in the infected host. We used a Pan-DR-binding epitope (PADRE)-derivatized-dendrimer (PDD), complexed with liposomal amphotericin B (LAmB) in an L. major mouse model and analyzed the therapeutic efficacy of low-dose PDD/LAmB vs full dose LAmB. PDD was shown to escort LAmB to APCs in vivo, enhanced the drug efficacy by 83% and drug APC targeting by 10-fold and significantly reduced parasite burden and toxicity. Fortuitously, the PDD immunopotentiating effect significantly enhanced parasite-specific T-cell responses in immunocompetent infected mice. PDD reduced the effective dose and toxicity of LAmB and resulted in elicitation of strong parasite specific T-cell responses. A reduced effective therapeutic dose was achieved by selective LAmB delivery to APC, bypassing bystander cells, reducing toxicity and inducing antiparasite immunity.

NMDA receptors in mouse anterior piriform cortex initialize early odor preference learning and L-type calcium channels engage for long-term memory.

PubMed

Mukherjee, Bandhan; Yuan, Qi

2016-10-14

The interactions of L-type calcium channels (LTCCs) and NMDA receptors (NMDARs) in memories are poorly understood. Here we investigated the specific roles of anterior piriform cortex (aPC) LTCCs and NMDARs in early odor preference memory in mice. Using calcium imaging in aPC slices, LTCC activation was shown to be dependent on NMDAR activation. Either D-APV (NMDAR antagonist) or nifedipine (LTCC antagonist) reduced somatic calcium transients in pyramidal cells evoked by lateral olfactory tract stimulation. However, nifedipine did not further reduce calcium in the presence of D-APV. In mice that underwent early odor preference training, blocking NMDARs in the aPC prevented short-term (3 hr) and long-term (24 hr) odor preference memory, and both memories were rescued when BayK-8644 (LTCC agonist) was co-infused. However, activating LTCCs in the absence of NMDARs resulted in loss of discrimination between the conditioned odor and a similar odor mixture at 3 hr. Elevated synaptic AMPAR expression at 3 hr was prevented by D-APV infusion but restored when LTCCs were directly activated, mirroring the behavioral outcomes. Blocking LTCCs prevented 24 hr memory and spared 3 hr memory. These results suggest that NMDARs mediate stimulus-specific encoding of odor memory while LTCCs mediate intracellular signaling leading to long-term memory.

Phylogeny of Immune Recognition: Processing and Presentation of Structurally Defined Proteins in Channel Catfish Immune Responses

PubMed Central

Vallejo, Abbe N.; Miller, Norman W.

1991-01-01

This work was undertaken to investigate whether or not antigen processing and presentation are important in channel catfish in vitro secondary immune responses elicited with structurally defined proteins, namely, pigeon heart cytochrome C (pCytC), hen egg lysozyme, and horse myoglobin. The use of in vitro antigen-pulsed and fixed B cells or monocytes as antigen presenting cells (APC) resulted in autologous peripheral blood leukocytes (PBL) responding with vigorous proliferation and antibody production in vitro. In addition, several long-term catfish monocyte lines have been found to function as efficient APC with autologous but not allogeneic responders. Subsequent separation of the responding PBL into sIg- (T-cell-enriched) and B (sIg+) cell subsets showed that both underwent proliferative responses to antigen-pulsed and fixed APC. Moreover, allogeneic cells used as APC were found to induce only strong mixed leukocyte reactions without specific in vitro antibody production. Initial attempts at identifying the immunogenic region(s) of the protein antigens for catfish indicated there are two such regions for pCytC, namely, peptides 66-80 and 81-104. PMID:1668258

Loss of single immunoglobulin interlukin-1 receptor-related molecule leads to enhanced colonic polyposis in Apcmin mice

PubMed Central

Xiao, Hui; Yin, Weiguo; Khan, Mohammed A.; Gulen, Muhammet F.; Zhou, Hang; Sham, Ho Pan; Jacobson, Kevan; Vallance, Bruce A.; Li, Xiaoxia

2011-01-01

Background & Aims Commensal bacteria can activate signaling by the toll-like and interleukin-1 receptors (TLR and IL-1R) to mediate pathogenesis of inflammatory bowel diseases and colitis-associated cancer. We investigated the role of the single immunoglobulin IL-1 receptor-related (SIGIRR) molecule, a negative regulator of TLR and IL-1R signaling, as a tumor suppressor to determine whether SIGIRR controls cell cycle progression, genetic instability, and colon tumor initiation by modulating commensal TLR signaling in the gastrointestinal tract. Methods We analyzed Apcmin/+/Sigirr-/- mice for polyps, microadenomas, and anaphase bridge index. Commensal bacteria were depleted from mice with antibiotics. Akt, mTOR and β-catenin pathways were examined by immunoblotting and immunohistochemistry. Loss of heterozygosity (LOH) of Apc and expression of cytokines and proinflammatory mediators were measured by non-quantitative or quantitative PCR. Results Apcmin/+/Sigirr-/- mice had increased LOH of Apc and microadenoma formation, resulting in spontaneous colonic polyposis, compared with Apc min/+/Sigirr+/+ mice. The increased colonic tumorigenesis that occurred in the Apcmin/+/Sigirr-/- mice depended on the presence of commensal bacteria in the gastrointestinal tract. Cell proliferation and chromosomal instability increased in colon crypt cells of the Apcmin/+/Sigirr-/- mice. Akt, mTOR and their substrates were hyper-activated in colon epithelium of Apcmin/+/Sigirr-/- mice in response to TLR or IL-1R ligands. Inhibition of the mTOR pathway by rapamycin reduced formation of microadenomas and polyps in the Apcmin/+/Sigirr-/- mice. Conclusions SIGIRR acts as a tumor suppressor in the colon by inhibiting TLR-induced, mTOR-mediated cell cycle progression and genetic instability. PMID:20416302

Microscopic adaptation of BaHfO3 and Y2O3 artificial pinning centers for strong and isotropic pinning landscape in YBa2Cu3O7-x thin films

NASA Astrophysics Data System (ADS)

Gautam, Bibek; Sebastian, Mary Ann; Chen, Shihong; Haugan, Timothy; Zhang, Wenrui; Huang, Jijie; Wang, Haiyan; Wu, Judy Z.

2018-07-01

A study of 3 vol% Y2O3 + 2-6 vol% BaHfO3 double-doped YBa2Cu3O7-x (BHO DD) epitaxial thin films was carried out to explore the morphology adaption of c-axis aligned one-dimensional BHO artificial pinning centers (1D APCs) to secondary Y2O3 nanoparticles (3D APCs). BHO 1D APCs have been predicted to have the least rigidity in an elastic strain energy model in APC/YBa2Cu3O7-x nanocomposite films. Consequently, they could be best ‘tuned’ away from the c-axis alignment by local strains generated by the Y2O3 3D APCs. This provides an opportunity to generate mixed-morphology APCs, especially at high BHO concentrations. Motivated by this, we have carried out a systematic study of the transport critical current density J c(H, T, θ) on the BHO DD samples in magnetic fields (H) up to 90 kOe at different H orientations from H//c-axis (θ = 0), to θ = 45°, and to H//ab-plane (θ = 90°). Enhanced pinning at all three orientations was observed as illustrated in the comparable low alpha (α) values in the range of 0.13-0.25 at 65 K, which is consistent with the mixed 1D (in c-axis) + 2D (in ab-plane) + 3D APCs observed in transmission electron microscopy (TEM). Upon increasing BHO concentration from 2 to 4 vol%, a monotonic increase of the accommodation field H* at θ = 0°, 45° and 90° was observed, indicative of the APC concentration increase of the mixed morphologies. At 6 vol% BHO, the H* continues the increase to 85 kOe at H//c-axis (θ = 0), and >90 kOe H//ab-plane (θ = 90°), while it decreases from 80 to 85 kOe at 2-4 vol% to 60 kOe at 6 vol% at θ = 45°, which is consistent with the TEM observation of the connection of 3D APCs, appeared at lower BHO concentration into 2D ones in ab-plane at the higher BHO concentrations. These results shed light on the quantitative adaptation of APCs of mixed morphologies with increasing BHO doping in the BHO DD thin films and are important for controlling the APC pinning landscape towards minimal angular dependence.

Myostatin gene inactivation prevents skeletal muscle wasting in cancer.

PubMed

Gallot, Yann S; Durieux, Anne-Cécile; Castells, Josiane; Desgeorges, Marine M; Vernus, Barbara; Plantureux, Léa; Rémond, Didier; Jahnke, Vanessa E; Lefai, Etienne; Dardevet, Dominique; Nemoz, Georges; Schaeffer, Laurent; Bonnieu, Anne; Freyssenet, Damien G

2014-12-15

Cachexia is a muscle-wasting syndrome that contributes significantly to morbidity and mortality of many patients with advanced cancers. However, little is understood about how the severe loss of skeletal muscle characterizing this condition occurs. In the current study, we tested the hypothesis that the muscle protein myostatin is involved in mediating the pathogenesis of cachexia-induced muscle wasting in tumor-bearing mice. Myostatin gene inactivation prevented the severe loss of skeletal muscle mass induced in mice engrafted with Lewis lung carcinoma (LLC) cells or in Apc(Min) (/+) mice, an established model of colorectal cancer and cachexia. Mechanistically, myostatin loss attenuated the activation of muscle fiber proteolytic pathways by inhibiting the expression of atrophy-related genes, MuRF1 and MAFbx/Atrogin-1, along with autophagy-related genes. Notably, myostatin loss also impeded the growth of LLC tumors, the number and the size of intestinal polyps in Apc(Min) (/+) mice, thus strongly increasing survival in both models. Gene expression analysis in the LLC model showed this phenotype to be associated with reduced expression of genes involved in tumor metabolism, activin signaling, and apoptosis. Taken together, our results reveal an essential role for myostatin in the pathogenesis of cancer cachexia and link this condition to tumor growth, with implications for furthering understanding of cancer as a systemic disease. ©2014 American Association for Cancer Research.

Engineering tolerance using biomaterials to target and control antigen presenting cells.

PubMed

Tostanoski, Lisa H; Gosselin, Emily A; Jewell, Christopher M

2016-05-01

Autoimmune diseases occur when cells of the adaptive immune system incorrectly recognize and attack "self" tissues. Importantly, the proliferation and differentiation of these cells is triggered and controlled by interactions with antigen presenting cells (APCs), such as dendritic cells. Thus, modulating the signals transduced by APCs (e.g., cytokines, costimulatory surface proteins) has emerged as a promising strategy to promote tolerance for diseases such as multiple sclerosis, type 1 diabetes, and lupus. However, many approaches have been hindered by non-specific activity of immunosuppressive or immunoregulatory cues, following systemic administration of soluble factors via traditional injections routes (e.g., subcutaneous, intravenous). Biomaterials offer a unique opportunity to control the delivery of tolerogenic signals in vivo via properties such as controlled particle size, tunable release kinetics, and co-delivery of multiple classes of cargo. In this review, we highlight recent reports that exploit these properties of biomaterials to target APCs and promote tolerance via three strategies, i) passive or active targeting of particulate carriers to APCs, ii) biomaterial-mediated control over antigen localization and processing, and iii) targeted delivery of encapsulated or adsorbed immunomodulatory signals. These reports represent exciting advances toward the goal of more effective therapies for autoimmune diseases, without the broad suppressive effects associated with current clinically-approved therapies.

[miR-182 promotes cell proliferation of cervical cancer cells by targeting adenomatous polyposis coli (APC) gene].

PubMed

Li, Pei; Hu, Jing; Zhang, Ying; Li, Jianping; Dang, Yunzhi; Zhang, Rui; Wei, Lichun; Shi, Mei

2018-02-01

Objective To investigate the role and mechanism of microRNA-182 (miR-182) in the proliferation of cervical cancer cells. Methods With liposome-mediated transient transfection method, the level of miR-182 in HeLa and SiHa cells was increased or decreased. CCK-8 assay and colony formation assay were used to observe the effect of miR-182 on the proliferation of cervical cancer cells. Using bioinformatics predictions, real-time quantitative PCR, and dual luciferase reporter assay, we clarified the role of miR-182 in posttranscriptional regulation of adenomatous polyposis coli (APC) gene and its effect on the downstream molecules (c-Myc and cyclin D1) of Wnt singling pathway. Results Up-regulation of miR-182 significantly promoted the proliferation of cervical cancer cells, while down-regulation of miR-182 significantly inhibited the proliferation of cervical cancer cells. Over-expression of miR-182 inhibited the expression of APC gene in cervical cancer cells and the regulation of miR-182 affected the expression of canonical Wnt signaling pathway downstream molecules in cervical cancer cells. Conclusion The miR-182 stimulates canonical Wnt signaling pathway by targeting APC gene and enhances the proliferation of cervical cancer cells.

Formalizing the Austrian Procedure Catalogue: A 4-step methodological analysis approach.

PubMed

Neururer, Sabrina Barbara; Lasierra, Nelia; Peiffer, Karl Peter; Fensel, Dieter

2016-04-01

Due to the lack of an internationally accepted and adopted standard for coding health interventions, Austria has established its own country-specific procedure classification system - the Austrian Procedure Catalogue (APC). Even though the APC is an elaborate coding standard for medical procedures, it has shortcomings that limit its usability. In order to enhance usability and usefulness, especially for research purposes and e-health applications, we developed an ontologized version of the APC. In this paper we present a novel four-step approach for the ontology engineering process, which enables accurate extraction of relevant concepts for medical ontologies from written text. The proposed approach for formalizing the APC consists of the following four steps: (1) comparative pre-analysis, (2) definition analysis, (3) typological analysis, and (4) ontology implementation. The first step contained a comparison of the APC to other well-established or elaborate health intervention coding systems in order to identify strengths and weaknesses of the APC. In the second step, a list of definitions of medical terminology used in the APC was obtained. This list of definitions was used as input for Step 3, in which we identified the most important concepts to describe medical procedures using the qualitative typological analysis approach. The definition analysis as well as the typological analysis are well-known and effective methods used in social sciences, but not commonly employed in the computer science or ontology engineering domain. Finally, this list of concepts was used in Step 4 to formalize the APC. The pre-analysis highlighted the major shortcomings of the APC, such as the lack of formal definition, leading to implicitly available, but not directly accessible information (hidden data), or the poor procedural type classification. After performing the definition and subsequent typological analyses, we were able to identify the following main characteristics of health interventions: (1) Procedural type, (2) Anatomical site, (3) Medical device, (4) Pathology, (5) Access, (6) Body system, (7) Population, (8) Aim, (9) Discipline, (10) Technique, and (11) Body Function. These main characteristics were taken as input of classes for the formalization of the APC. We were also able to identify relevant relations between classes. The proposed four-step approach for formalizing the APC provides a novel, systematically developed, strong framework to semantically enrich procedure classifications. Although this methodology was designed to address the particularities of the APC, the included methods are based on generic analysis tasks, and therefore can be re-used to provide a systematic representation of other procedure catalogs or classification systems and hence contribute towards a universal alignment of such representations, if desired. Copyright © 2015 Elsevier Inc. All rights reserved.

Nanoparticulate carbon black in cigarette smoke induces DNA cleavage and Th17-mediated emphysema.

PubMed

You, Ran; Lu, Wen; Shan, Ming; Berlin, Jacob M; Samuel, Errol Lg; Marcano, Daniela C; Sun, Zhengzong; Sikkema, William Ka; Yuan, Xiaoyi; Song, Lizhen; Hendrix, Amanda Y; Tour, James M; Corry, David B; Kheradmand, Farrah

2015-10-05

Chronic inhalation of cigarette smoke is the major cause of sterile inflammation and pulmonary emphysema. The effect of carbon black (CB), a universal constituent of smoke derived from the incomplete combustion of organic material, in smokers and non-smokers is less known. In this study, we show that insoluble nanoparticulate carbon black (nCB) accumulates in human myeloid dendritic cells (mDCs) from emphysematous lung and in CD11c(+) lung antigen presenting cells (APC) of mice exposed to smoke. Likewise, nCB intranasal administration induced emphysema in mouse lungs. Delivered by smoking or intranasally, nCB persisted indefinitely in mouse lung, activated lung APCs, and promoted T helper 17 cell differentiation through double-stranded DNA break (DSB) and ASC-mediated inflammasome assembly in phagocytes. Increasing the polarity or size of CB mitigated many adverse effects. Thus, nCB causes sterile inflammation, DSB, and emphysema and explains adverse health outcomes seen in smokers while implicating the dangers of nCB exposure in non-smokers.

Cancer-induced anorexia and malaise are mediated by CGRP neurons in the parabrachial nucleus.

PubMed

Campos, Carlos A; Bowen, Anna J; Han, Sung; Wisse, Brent E; Palmiter, Richard D; Schwartz, Michael W

2017-07-01

Anorexia is a common manifestation of chronic diseases, including cancer. Here we investigate the contribution to cancer anorexia made by calcitonin gene-related peptide (CGRP) neurons in the parabrachial nucleus (PBN) that transmit anorexic signals. We show that CGRP PBN neurons are activated in mice implanted with Lewis lung carcinoma cells. Inactivation of CGRP PBN neurons before tumor implantation prevents anorexia and loss of lean mass, and their inhibition after symptom onset reverses anorexia. CGRP PBN neurons are also activated in Apc min/+ mice, which develop intestinal cancer and lose weight despite the absence of reduced food intake. Inactivation of CGRP PBN neurons in Apc min/+ mice permits hyperphagia that counteracts weight loss, revealing a role for these neurons in a 'nonanorexic' cancer model. We also demonstrate that inactivation of CGRP PBN neurons prevents lethargy, anxiety and malaise associated with cancer. These findings establish CGRP PBN neurons as key mediators of cancer-induced appetite suppression and associated behavioral changes.

Downregulation of adenomatous polyposis coli by microRNA-663 promotes odontogenic differentiation through activation of Wnt/beta-catenin signaling

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

Kim, Jae-Sung; Park, Min-Gyeong; Lee, Seul Ah

Highlights: • miR-663 is significantly up-regulated during MDPC-23 odontoblastic cell differentiation. • miR-663 accelerates mineralization in MDPC-23 odontoblastic cells without cell proliferation. • miR-663 promotes odontoblastic cell differentiation by targeting APC and activating Wnt/β-catenin signaling in MDPC-23 cells. - Abstract: MicroRNAs (miRNAs) regulate cell differentiation by inhibiting mRNA translation or by inducing its degradation. However, the role of miRNAs in odontogenic differentiation is largely unknown. In this present study, we observed that the expression of miR-663 increased significantly during differentiation of MDPC-23 cells to odontoblasts. Furthermore, up-regulation of miR-663 expression promoted odontogenic differentiation and accelerated mineralization without proliferation in MDPC-23more » cells. In addition, target gene prediction for miR-663 revealed that the mRNA of the adenomatous polyposis coli (APC) gene, which is associated with the Wnt/β-catenin signaling pathway, has a miR-663 binding site in its 3′-untranslated region (3′UTR). Furthermore, APC expressional was suppressed significantly by miR-663, and this down-regulation of APC expression triggered activation of Wnt/β-catenin signaling through accumulation of β-catenin in the nucleus. Taken together, these findings suggest that miR-663 promotes differentiation of MDPC-23 cells to odontoblasts by targeting APC-mediated activation of Wnt/β-catenin signaling. Therefore, miR-663 can be considered a critical regulator of odontoblast differentiation and can be utilized for developing miRNA-based therapeutic agents.« less

Endothelial microparticles released by activated protein C protect beta cells through EPCR/PAR1 and annexin A1/FPR2 pathways in islets.

PubMed

Kreutter, Guillaume; Kassem, Mohamad; El Habhab, Ali; Baltzinger, Philippe; Abbas, Malak; Boisrame-Helms, Julie; Amoura, Lamia; Peluso, Jean; Yver, Blandine; Fatiha, Zobairi; Ubeaud-Sequier, Geneviève; Kessler, Laurence; Toti, Florence

2017-11-01

Islet transplantation is associated with early ischaemia/reperfusion, localized coagulation and redox-sensitive endothelial dysfunction. In animal models, islet cytoprotection by activated protein C (aPC) restores islet vascularization and protects graft function, suggesting that aPC triggers various lineages. aPC also prompts the release of endothelial MP that bear EPCR, its specific receptor. Microparticles (MP) are plasma membrane procoagulant vesicles, surrogate markers of stress and cellular effectors. We measured the cytoprotective effects of aPC on endothelial and insulin-secreting Rin-m5f β-cells and its role in autocrine and paracrine MP-mediated cell crosstalk under conditions of oxidative stress. MP from aPC-treated primary endothelial (EC) or β-cells were applied to H 2 O 2 -treated Rin-m5f. aPC activity was measured by enzymatic assay and ROS species by dihydroethidium. The capture of PKH26-stained MP and the expression of EPCR were probed by fluorescence microscopy and apoptosis by flow cytometry. aPC treatment enhanced both annexin A1 (ANXA1) and PAR-1 expression in EC and to a lesser extent in β-cells. MP from aPC-treated EC (eM aPC ) exhibited high EPCR and annexin A1 content, protected β-cells, restored insulin secretion and were captured by 80% of β cells in a phosphatidylserine and ANXA1-dependent mechanism. eMP activated EPCR/PAR-1 and ANXA1/FPR2-dependent pathways and up-regulated the expression of EPCR, and of FPR2/ALX, the ANXA1 receptor. Cytoprotection was confirmed in H 2 O 2 -treated rat islets with increased viability (62% versus 48% H 2 O 2 ), reduced apoptosis and preserved insulin secretion in response to glucose elevation (16 versus 5 ng/ml insulin per 10 islets). MP may prove a promising therapeutic tool in the protection of transplanted islets. © 2017 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

Curcumin's effect on intestinal inflammation and tumorigenesis in the ApcMin/+ mouse.

PubMed

Murphy, E Angela; Davis, J Mark; McClellan, Jamie L; Gordon, Benjamin T; Carmichael, Martin D

2011-02-01

Curcumin's benefits on tumorigenesis are thought to be mediated by its antiinflammatory activity; however, these effects have not been well characterized in a mouse model of colon cancer. We examined the effects of curcumin on intestinal inflammation in the Apc(Min/+) mouse. Apc(Min/+) mice were given a placebo or curcumin (2%) diet from 4 to 18 weeks of age (n = 10/group). C57BL/6 mice were used as a wild-type control (n = 10/group). Intestines were analyzed for polyp burden (sections 1, 4, and 5) and for mRNA expression, and concentration of interleukin (IL)-1β, IL-6, tumor necrosis factor-α, and chemokine ligand 2 (CCL2) (sections 2 and 3). Plasma was collected for concentration of CCL2. Curcumin decreased total intestinal polyps by 75% (P < 0.05) in all size categories [>2 mm (65%), 1-2 mm (72%), <1 mm (82%); P < 0.05]. mRNA expression of IL-1β, IL-6, tumor necrosis factor-α, and CCL2 was elevated (P < 0.05) and curcumin blunted this increase (P < 0.05). Protein concentration of IL-1β, IL-6 (section 3), and CCL2 was increased (P < 0.05) and curcumin reduced this response for IL-1β (section 2) and CCL2 (P < 0.05). Curcumin also offset the increase in plasma CCL2 (P < 0.05). The benefits of curcumin in colon cancer may be at least in part mediated by its antiinflammatory activity.

Pathogen-mimicking vaccine delivery system designed with a bioactive polymer (inulin acetate) for robust humoral and cellular immune responses.

PubMed

Kumar, Sunny; Kesharwani, Siddharth S; Kuppast, Bhimanna; Bakkari, Mohammed Ali; Tummala, Hemachand

2017-09-10

New and improved vaccines are needed against challenging diseases such as malaria, tuberculosis, Ebola, influenza, AIDS, and cancer. The majority of existing vaccine adjuvants lack the ability to significantly stimulate the cellular immune response, which is required to prevent the aforementioned diseases. This study designed a novel particulate based pathogen-mimicking vaccine delivery system (PMVDS) to target antigen-presenting-cells (APCs) such as dendritic cells. The uniqueness of PMVDS is that the polymer used to prepare the delivery system, Inulin Acetate (InAc), activates the innate immune system. InAc was synthesized from the plant polysaccharide, inulin. PMVDS provided improved and persistent antigen delivery to APCs as an efficient vaccine delivery system, and simultaneously, activated Toll-Like Receptor-4 (TLR-4) on APCs to release chemokine's/cytokines as an immune-adjuvant. Through this dual mechanism, PMVDS robustly stimulated both the humoral (>32 times of IgG1 levels vs alum) and the cell-mediated immune responses against the encapsulated antigen (ovalbumin) in mice. More importantly, PMVDS stimulated both cytotoxic T cells and natural killer cells of cell-mediated immunity to provide tumor (B16-ova-Melanoma) protection in around 40% of vaccinated mice and significantly delayed tumor progression in rest of the mice. PMVDS is a unique bio-active vaccine delivery technology with broader applications for vaccines against cancer and several intracellular pathogens, where both humoral and cellular immune responses are desired. Copyright © 2017 Elsevier B.V. All rights reserved.

Viral Sequestration of Antigen Subverts Cross Presentation to CD8+ T Cells

PubMed Central

Tewalt, Eric F.; Grant, Jean M.; Granger, Erica L.; Palmer, Douglas C.; Heuss, Neal D.; Gregerson, Dale S.; Restifo, Nicholas P.; Norbury, Christopher C.

2009-01-01

Virus-specific CD8+ T cells (TCD8+) are initially triggered by peptide-MHC Class I complexes on the surface of professional antigen presenting cells (pAPC). Peptide-MHC complexes are produced by two spatially distinct pathways during virus infection. Endogenous antigens synthesized within virus-infected pAPC are presented via the direct-presentation pathway. Many viruses have developed strategies to subvert direct presentation. When direct presentation is blocked, the cross-presentation pathway, in which antigen is transferred from virus-infected cells to uninfected pAPC, is thought to compensate and allow the generation of effector TCD8+. Direct presentation of vaccinia virus (VACV) antigens driven by late promoters does not occur, as an abortive infection of pAPC prevents production of these late antigens. This lack of direct presentation results in a greatly diminished or ablated TCD8+ response to late antigens. We demonstrate that late poxvirus antigens do not enter the cross-presentation pathway, even when identical antigens driven by early promoters access this pathway efficiently. The mechanism mediating this novel means of viral modulation of antigen presentation involves the sequestration of late antigens within virus factories. Early antigens and cellular antigens are cross-presented from virus-infected cells, as are late antigens that are targeted to compartments outside of the virus factories. This virus-mediated blockade specifically targets the cross-presentation pathway, since late antigen that is not cross-presented efficiently enters the MHC Class II presentation pathway. These data are the first to describe an evasion mechanism employed by pathogens to prevent entry into the cross-presentation pathway. In the absence of direct presentation, this evasion mechanism leads to a complete ablation of the TCD8+ response and a potential replicative advantage for the virus. Such mechanisms of viral modulation of antigen presentation must also be taken into account during the rational design of antiviral vaccines. PMID:19478869

Acidic pre-conditioning suppresses apoptosis and increases expression of Bcl-xL in coronary endothelial cells under simulated ischaemia.

PubMed

Kumar, S; Reusch, H P; Ladilov, Y

2008-01-01

Ischaemic pre-conditioning has a powerful protective potential against ischaemia-induced cell death, and acidosis is an important feature of ischaemia and can lead to apoptosis. Here we tested whether pre-conditioning with acidosis, that is, acidic pre-conditioning (APC), may protect coronary endothelial cells (EC) against apoptosis induced by simulated ischaemia. For pre-conditioning, EC were exposed fo 40 min. to acidosis (pH 6.4) followed by a 14-hrs recovery period (pH 7.4) and finally treated for 2 hrs with simulated ischaemia (glucose-free anoxia at pH 6.4). Cells undergoing apoptosis were visualized by chromatin staining or by determination of caspase-3 activity Simulated ischaemia in untreated EC increased caspase-3 activity and the number of apoptotic cell (31.3 +/- 1.3%versus 3.9 +/- 0.6% in control). APC significantly reduced the rate of apoptosis (14.2 +/- 1.3%) and caspase-3 activity. Western blot analysis exploring the under lying mechanism leading to this protection revealed suppression of the endoplasmic reticulum- (reduced cleavage of caspase-12) and mitochondria-mediated (reduced cytochrome C release) pathways of apoptosis. These effects were associated with an over-expression of the anti-apoptotic protein Bcl-xL 14 hrs after APC, whereas no effect on the expression of Bcl-2, Bax, Bak, procaspase-12, reticulum-localized chaperones (GRP78, calreticulin), HSP70, HSP32 and HSP27 could be detected. Knock-down of Bcl-xL by siRNA-treatment prevented the protective effect of APC. In conclusion, short acidic pre-treatment can protect EC against ischaemic apoptosis. The mechanism of this protection consists of suppression of the endoplasmic reticulum- and mitochondria-mediated pathways. Over-expression of the anti apoptotic protein Bcl-xL is responsible for the increased resistance to apoptosis during ischaemic insult.

OX40 ligand-transduced tumor cell vaccine synergizes with GM-CSF and requires CD40-Apc signaling to boost the host T cell antitumor response.

PubMed

Gri, Giorgia; Gallo, Elena; Di Carlo, Emma; Musiani, Piero; Colombo, Mario P

2003-01-01

Efficient T cell priming by GM-CSF and CD40 ligand double-transduced C26 murine colon carcinoma is not sufficient to cure metastases in a therapeutic setting. To determine whether a cellular vaccine that interacts directly with both APC and T cells in vivo might be superior, we generated C26 carcinoma cells transduced with the T cell costimulatory molecule OX40 ligand (OX40L) either alone (C26/OX40L) or together with GM-CSF (C26/GM/OX40L), which is known to activate APC. Mice injected with C26/OX40L cells displayed only a delay in tumor growth, while the C26/GM/OX40L tumor regressed in 85% of mice. Tumor rejection required granulocytes, CD4+, CD8+ T cells, and APC-mediated CD40-CD40 ligand cosignaling, but not IFN-gamma or IL-12 as shown using subset-depleted and knockout (KO) mice. CD40KO mice primed with C26/GM/OX40L cells failed to mount a CTL response, and T cells infiltrating the C26/GM/OX40L tumor were OX40 negative, suggesting an impairment in APC-T cell cross-talk in CD40KO mice. Indeed, CD4+ T cell-depleted mice failed to mount any CTL activity against the C26 tumor, while treatment with agonistic mAb to CD40, which acts on APC, bypassed the requirement for CD4+ T cells and restored CTL activation. C26/GM/OX40L cells cured 83% of mice bearing lung metastases, whereas C26/OX40L or C26/GM vaccination cured only 28 and 16% of mice, respectively. These results indicate the synergistic activity of OX40L and GM-CSF in a therapeutic setting.

A Model of Parental Achievement-Oriented Psychological Control in Academically Gifted Students

ERIC Educational Resources Information Center

Garn, Alex C.; Jolly, Jennifer L.

2015-01-01

This study investigated achievement-oriented parent socialization as it pertains to school avoidance in a sample of gifted students. A serial mediation model examining relationships among parental achievement-oriented psychological control (APC), fear of academic failure, academic amotivation, and school avoidance was tested. The sample included…

Long-lived Min mice develop advanced intestinal cancers through a genetically conservative pathway.

PubMed

Halberg, Richard B; Waggoner, Jesse; Rasmussen, Kristen; White, Alanna; Clipson, Linda; Prunuske, Amy J; Bacher, Jeffery W; Sullivan, Ruth; Washington, Mary Kay; Pitot, Henry C; Petrini, John H J; Albertson, Donna G; Dove, William F

2009-07-15

C57BL/6J mice carrying the Min allele of Adenomatous polyposis coli (Apc) develop numerous adenomas along the entire length of the intestine and consequently die at an early age. This short lifespan would prevent the accumulation of somatic genetic mutations or epigenetic alterations necessary for tumor progression. To overcome this limitation, we generated F(1) Apc(Min/+) hybrids by crossing C57BR/cdcJ and SWR/J females to C57BL/6J Apc(Min/+) males. These hybrids developed few intestinal tumors and often lived longer than 1 year. Many of the tumors (24-87%) were invasive adenocarcinomas, in which neoplastic tissue penetrated through the muscle wall into the mesentery. In a few cases (3%), lesions metastasized by extension to regional lymph nodes. The development of these familial cancers does not require chromosomal gains or losses, a high level of microsatellite instability, or the presence of Helicobacter. To test whether genetic instability might accelerate tumor progression, we generated Apc(Min/+) mice homozygous for the hypomorphic allele of the Nijmegen breakage syndrome gene (Nbs1(DeltaB)) and also treated Apc(Min/+) mice with a strong somatic mutagen. These imposed genetic instabilities did not reduce the time required for cancers to form nor increase the percentage of cancers nor drive progression to the point of distant metastasis. In summary, we have found that the Apc(Min/+) mouse model for familial intestinal cancer can develop frequent invasive cancers in the absence of overt genomic instability. Possible factors that promote invasion include age-dependent epigenetic changes, conservative somatic recombination, or direct effects of alleles in the F(1) hybrid genetic background.

Production of the α and β Subunits of Spirulina Allophycocyanin and C-Phycocyanin in Escherichia coli : A Comparative Study of Their Antioxidant Activities.

PubMed

Cherdkiatikul, Thiti; Suwanwong, Yaneenart

2014-07-01

Allophycocyanin and c-phycocyanin have been reported to be potent antioxidants. In this work, the genes encoding the apo-proteins of allophycocyanin α (ApcA), allophycocyanin β (ApcB), c-phycocyanin α (CpcA), and c-phycocyanin β (CpcB) from Spirulina platensis were cloned, and the recombinant proteins were produced in Escherichia coli to study their antioxidant effects. All four recombinant phycocyanins could be produced in the soluble form and purified to more than 97% purity. The results of radical scavenging assays showed that the Trolox equivalent values for peroxyl radical scavenging by the ApcA, ApcB, CpcA, and CpcB proteins were 1.81 ± 0.2 µM, 1.98 ± 0.22 µM, 0.95 ± 0.15 µM, and 1.49 ± 0.15 µM, respectively. The IC50 values for hydroxyl radical scavenging of ApcA, ApcB, CpcA, CpcB, and Trolox were 269 ± 9 µg/mL, 190 ± 5 µg/mL, 129 ± 8 µg/mL, 108 ± 4 µg/mL, and 195 ± 12 µg/mL, respectively. These results indicated that allophycocyanin exhibited higher activity than c-phycocyanin in scavenging peroxyl radicals, whereas c-phycocyanin exhibited higher activity than allophycocyanin in scavenging hydroxyl radicals. All of the apo-phycocyanin subunits possessed strong antioxidant activities and can be further developed and applied to the food and drug industries. However, the selection of the most useful antioxidant should depend on the type of targeted free radical to obtain the highest efficiency. © 2014 Society for Laboratory Automation and Screening.

Gene expression profiling of dendritic cells by microarray.

PubMed

Foti, Maria; Ricciardi-Castagnoli, Paola; Granucci, Francesca

2007-01-01

The immune system of vertebrate animals has evolved to respond to different types of perturbations (invading pathogens, stress signals), limiting self-tissue damage. The decision to activate an immune response is made by antigen-presenting cells (APCs) that are quiescent until they encounter a foreign microorganism or inflammatory stimuli. Early activated APCs trigger innate immune responses that represent the first line of reaction against invading pathogens to limit the infections. At later times, activated APCs acquire the ability to prime antigen-specific immune responses that clear the infections and give rise to memory. During the immune response self-tissue damage is limited and tolerance to self is maintained through life. Among the cells that constitute the immune system, dendritic cells (DC) play a central role. They are extremely versatile APCs involved in the initiation of both innate and adaptive immunity and also in the differentiation of regulatory T cells required for the maintenance of self-tolerance. How DC can mediate these diverse and almost contradictory functions has recently been investigated. The plasticity of these cells allows them to undergo a complete genetic reprogramming in response to external microbial stimuli with the sequential acquisition of different regulatory functions in innate and adaptive immunity. The specific genetic reprogramming DC undergo upon activation can be easily investigated by using microarrays to perform global gene expression analysis in different conditions.

Alkylphosphocholines and curcumin induce programmed cell death in cutaneous T-cell lymphoma cell lines.

PubMed

Yosifov, Deyan Y; Kaloyanov, Kaloyan A; Guenova, Margarita L; Prisadashka, Kamelia; Balabanova, Maria B; Berger, Martin R; Konstantinov, Spiro M

2014-01-01

While most patients with early-stage cutaneous T-cell lymphomas (CTCL) have a very good prognosis, the survival of patients with extensive tumour stage and visceral involvement remains extremely poor and necessitates the development of more effective treatment modalities. In this study, we evaluated the in vitro effects of two alkylphosphocholines (APCs, miltefosine and erufosine) and the polyphenolic compound curcumin on 5 human CTCL cell lines (Hut-78, HH, MJ, My-La CD4+ and My-La CD8+). All tested drugs showed considerable cytotoxic activity, as determined by the MTT dye reduction assay. The IC50 values of both APCs ranged from the low micromolar level (Hut-78 cells) to 60-80μM (HH cells). The IC50 values of curcumin ranged from 12 to 24μM. All tested drugs induced apoptosis, as ascertained by morphological changes, DNA fragmentation and activation of caspase cascades. Miltefosine and erufosine induced dephosphorylation of Akt in My-La CD8+ cells and phosphorylation of JNK in Hut-78 and My-La CD8+ cells. APCs increased the level of the autophagic marker LC3B in Hut-78 and MJ cells. Results from co-treatment with autophagy modulators suggested that the cytotoxicity of APCs in CTCL cells is mediated, at least in part, by induction of autophagy. Copyright © 2013 Elsevier Ltd. All rights reserved.

TLR-mediated stimulation of APC: Distinct cytokine responses of B cells and dendritic cells

PubMed Central

Barr, Tom A; Brown, Sheila; Ryan, Gemma; Zhao, Jiexin; Gray, David

2007-01-01

In addition to their role in humoral immunity, B lymphocytes are important antigen-presenting cells (APC). In the same way as other APC, B cells make cytokines upon activation and have the potential to modulate T cell responses. In this study, we investigated which mouse B cell subsets are the most potent cytokine producers, and examined the role of Toll-like receptors (TLR) in the control of secretion of IL-6, IL-10, IL-12 and IFN-γ by B cells. Production of some cytokines was restricted to particular subsets. Marginal zone and B1 cells were the predominant source of B cell IL-10 in the spleen. Conversely, follicular B cells were found to express IFN-γ mRNA directly ex vivo. The nature of the activating stimulus dramatically influenced the cytokine made by B cells. Thus, in response to combined TLR stimulation, or via phorbol esters, IFN-γ was secreted. IL-10 was elicited by T-dependent activation or stimulation through TLR2, 4 or 9. This pattern of cytokine expression contrasts with that elicited from dendritic cells. QRT-PCR array data indicate that this may be due to differential expression of TLR signalling molecules, effectors and adaptors. Our data highlight the potentially unique nature of immune modulation when B cells act as APC. PMID:17918201

mTOR regulates metabolic adaptation of APCs in the lung and controls the outcome of allergic inflammation.

PubMed

Sinclair, Charles; Bommakanti, Gayathri; Gardinassi, Luiz; Loebbermann, Jens; Johnson, Matthew Joseph; Hakimpour, Paul; Hagan, Thomas; Benitez, Lydia; Todor, Andrei; Machiah, Deepa; Oriss, Timothy; Ray, Anuradha; Bosinger, Steven; Ravindran, Rajesh; Li, Shuzhao; Pulendran, Bali

2017-09-08

Antigen-presenting cells (APCs) occupy diverse anatomical tissues, but their tissue-restricted homeostasis remains poorly understood. Here, working with mouse models of inflammation, we found that mechanistic target of rapamycin (mTOR)-dependent metabolic adaptation was required at discrete locations. mTOR was dispensable for dendritic cell (DC) homeostasis in secondary lymphoid tissues but necessary to regulate cellular metabolism and accumulation of CD103 + DCs and alveolar macrophages in lung. Moreover, while numbers of mTOR-deficient lung CD11b + DCs were not changed, they were metabolically reprogrammed to skew allergic inflammation from eosinophilic T helper cell 2 (T H 2) to neutrophilic T H 17 polarity. The mechanism for this change was independent of translational control but dependent on inflammatory DCs, which produced interleukin-23 and increased fatty acid oxidation. mTOR therefore mediates metabolic adaptation of APCs in distinct tissues, influencing the immunological character of allergic inflammation. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Regulation of the Anaphase-promoting Complex–Separase Cascade by Transforming Growth Factor-β Modulates Mitotic Progression in Bone Marrow Stromal Cells

PubMed Central

Fujita, Takeo; Epperly, Michael W.; Zou, Hui; Greenberger, Joel S.

2008-01-01

Alteration of the tumor microenvironment by aberrant stromal cells influences many aspects of cell biology, including differentiation of stem cells and tumor metastasis. The role of transforming growth factor (TGF)-β signaling in stromal cells of the tissue microenvironment is critical to both pathways. We examined murine marrow stromal cells with deletion of Smad3 and found that they have an altered cell cycle profile, with a higher fraction of cells in G2/M phase. Deletion of Smad3 significantly abrogates TGF-β signaling and suppresses phosphorylation of CDC27–anaphase-promoting complex (APC) during mitosis, thereby resulting in elevated cyclin-dependent kinase (CDK)1 activity via increased levels of cyclin B. Enhanced CDK1 activity due to deregulation of APC leads in turn to hyperphosphorylation of separase, impeding chromatid separation. A residue Ser1126Ala mutation in separase specifically abolished separase hyperphosphorylation in Smad3-deficient cells. The present results unveil a new function for the TGF-β pathway in the regulation of APC to mediate chromatid separation during mitosis. PMID:18843049

Eicosanoids: an emerging role in dendritic cell biology.

PubMed

Harizi, Hedi; Gualde, Norbert

2004-01-01

The arachidonic acid (AA)-derived metabolites, termed eicosanoids, are potent lipid mediators with a key role in immune and inflammatory responses. In the immune system, eicosanoids such as prostaglandins (PGs) and leukotrienes (LTs) are produced predominately by antigen-presenting cells (APC), including macrophages and dendritic cells (DC). DC constitute a family of bone marrow-derived professional APC that play a critical role in the induction and modulation of both innate and adaptive immunity. For many years, macrophages were considered as major producers of eicosanoids that are thought to drastically affect their function. Studies concerning the modulation of DC biology by eicosanoids show that PGs and LTs have the potential to affect the maturation, cytokine-producing capacity, Th cell-polarizing ability, and migration of DC. In addition, the development of DC from bone marrow progenitors appears to be under the control of some eicosanoids. Understanding the actions of eicosanoids and their receptors on APC functions is crucial for the generation of efficient DC for therapeutic purposes in patients. In this review, we summarize the current understanding of how DC functions are modulated by eicosanoids.

Activated protein C and its potential applications in prevention of islet β-cell damage and diabetes.

PubMed

Xue, Meilang; Jackson, Christopher J

2014-01-01

Activated protein C (APC) is derived from its precursor, protein C (PC). Originally thought to be synthesized exclusively by the liver, recent reports have shown that PC is also produced by many other cells including pancreatic islet β cells. APC functions as a physiological anticoagulant with anti-inflammatory, anti-apoptotic, and barrier-stabilizing properties. APC exerts its protective effects via an intriguing mechanism requiring combinations of endothelial PC receptor, protease-activated receptors, epidermal growth factor receptor, Tie2 or CD11b, depending on cell types. Diabetes is a chronic condition resulted from the body's inability to produce and/or properly use insulin. The prevalence of diabetes has risen dramatically and has become one of the major causes of premature mortality and morbidity worldwide. Diabetes prevention is an ideal approach to reduce this burden. Type 1 and type 2 diabetes are the major forms of diabetes mellitus, and both are characterized by an autoimmune response, intraislet inflammation, β-cell apoptosis, and progressive β-cell loss. Protecting β-cell from damage is critical in both prevention and treatment of diabetes. Recent in vitro and animal studies show that APC's strong anti-inflammatory and anti-apoptotic properties are beneficial in preventing β-cell destruction and diabetes in the NOD mouse model of type 1 diabetes. Future preventive and therapeutic uses of APC in diabetes look very promising. © 2014 Elsevier Inc. All rights reserved.

HLA-G Expression Pattern: Reliable Assessment for Pregnancy Outcome Prediction

PubMed Central

Mosaferi, Elnaz; Majidi, Jafar; Mohammadian, Mojdeh; Babaloo, Zohreh; Monfaredan, Amir; Baradaran, Behzad

2013-01-01

Because mothers and fathers are more or less dissimilar at multiple HLA loci, mother considers her fetus as a semi-allograft. Mother's immune system may recognize paternal HLA as foreign antigen and may develop anti-paternal HLA antibodies and cytotoxic T lymphocyte. There are some mechanisms that modulate maternal immune responses during pregnancy, in order to make uterus an immune privileged site. This immunosuppression is believed to be mediated, at least partly, by HLA-G, non-classical class I human leukocyte antigen (HLA) molecule that is strongly expressed in cytotrophoblast and placenta. The major HLA-G function is its ability to inhibit T and B lymphocytes, NK cells and antigen-presenting cells (APC).Since HLA-G is expressed strongly at the maternofetal interface and has an essential role in immunosuppression, HLA-G polymorphism and altered expression of HLA-G seems to be associated with some complications of pregnancy, such as pre-eclampsia, recurrent misscariage and failure in IVF.This perspective discusses recent findings about HLA-G genetics, function, expression and polymorphism; and focus on HLA-G role in the etiology of recurrent miscarriage. PMID:24312875

Increased Frequency of T Follicular Helper Cells and Elevated Interleukin-27 Plasma Levels in Patients with Pemphigus

PubMed Central

Schmidt, Thomas; Seipelt, Maria; Tackenberg, Björn; Möbs, Christian; Ghoreschi, Kamran; Hertl, Michael; Eming, Rüdiger

2016-01-01

Pemphigus is an autoimmune disease in which IgG auto-antibodies (auto-ab) against the desmosomal cadherins desmoglein (Dsg) 3 and Dsg1 cause loss of epidermal keratinocyte adhesion. Aim of this study was to investigate cytokines derived from antigen-presenting cells (APC) and their relation to CD4+ T cell subpopulations and to the auto-ab response in pemphigus. In this regard, patients with pemphigus were compared to patients with myasthenia gravis (MG), an unrelated auto-ab–mediated autoimmune disease, and healthy controls. In pemphigus and MG, the plasma concentrations of the APC-derived immunomodulatory cytokine IL-27 were highly increased. Strikingly, IL-27 strongly correlated with Dsg-specific IgG auto-ab titers. T helper (Th) 17 cells were augmented in both pemphigus and MG patients while T follicular helper (Tfh) cells, which are essential in providing B cell help, were increased only in pemphigus along with increasing plasma concentrations of IL-21, a cytokine produced by Th17 and Tfh cells. Moreover, we could detect Dsg3-specific autoreactive T cells producing IL-21 upon ex vivo stimulation with Dsg3. These findings suggest that IL-27 and IL-21-producing T cells, are involved in the pathogenesis of pemphigus. The further characterization of IL-21-producing T cells and of the role of IL-27 will lead to a more defined understanding of the auto-ab response in pemphigus. PMID:26872212

Current knowledge on psoriasis and autoimmune diseases

PubMed Central

Ayala-Fontánez, Nilmarie; Soler, David C; McCormick, Thomas S

2016-01-01

Psoriasis is a prevalent, chronic inflammatory disease of the skin, mediated by crosstalk between epidermal keratinocytes, dermal vascular cells, and immunocytes such as antigen presenting cells (APCs) and T cells. Exclusive cellular “responsibility” for the induction and maintenance of psoriatic plaques has not been clearly defined. Increased proliferation of keratinocytes and endothelial cells in conjunction with APC/T cell/monocyte/macrophage inflammation leads to the distinct epidermal and vascular hyperplasia that is characteristic of lesional psoriatic skin. Despite the identification of numerous susceptibility loci, no single genetic determinant has been identified as responsible for the induction of psoriasis. Thus, numerous other triggers of disease, such as environmental, microbial and complex cellular interactions must also be considered as participants in the development of this multifactorial disease. Recent advances in therapeutics, especially systemic so-called “biologics” have provided new hope for identifying the critical cellular targets that drive psoriasis pathogenesis. Recent recognition of the numerous co-morbidities and other autoimmune disorders associated with psoriasis, including inflammatory bowel disease, multiple sclerosis, rheumatoid arthritis, and systemic lupus erythematosus suggest common signaling elements and cellular mediators may direct disease pathogenesis. In this review, we discuss common cellular pathways and participants that mediate psoriasis and other autoimmune disorders that share these cellular signaling pathways. PMID:29387591

Nanoparticulate carbon black in cigarette smoke induces DNA cleavage and Th17-mediated emphysema

PubMed Central

You, Ran; Lu, Wen; Shan, Ming; Berlin, Jacob M; Samuel, Errol LG; Marcano, Daniela C; Sun, Zhengzong; Sikkema, William KA; Yuan, Xiaoyi; Song, Lizhen; Hendrix, Amanda Y; Tour, James M; Corry, David B; Kheradmand, Farrah

2015-01-01

Chronic inhalation of cigarette smoke is the major cause of sterile inflammation and pulmonary emphysema. The effect of carbon black (CB), a universal constituent of smoke derived from the incomplete combustion of organic material, in smokers and non-smokers is less known. In this study, we show that insoluble nanoparticulate carbon black (nCB) accumulates in human myeloid dendritic cells (mDCs) from emphysematous lung and in CD11c+ lung antigen presenting cells (APC) of mice exposed to smoke. Likewise, nCB intranasal administration induced emphysema in mouse lungs. Delivered by smoking or intranasally, nCB persisted indefinitely in mouse lung, activated lung APCs, and promoted T helper 17 cell differentiation through double-stranded DNA break (DSB) and ASC-mediated inflammasome assembly in phagocytes. Increasing the polarity or size of CB mitigated many adverse effects. Thus, nCB causes sterile inflammation, DSB, and emphysema and explains adverse health outcomes seen in smokers while implicating the dangers of nCB exposure in non-smokers. DOI: http://dx.doi.org/10.7554/eLife.09623.001 PMID:26437452

Immunopurification of adenomatous polyposis coli (APC) proteins

PubMed Central

2013-01-01

Background The adenomatous polyposis coli (APC) tumour suppressor gene encodes a 2843 residue (310 kDa) protein. APC is a multifunctional protein involved in the regulation of β-catenin/Wnt signalling, cytoskeletal dynamics and cell adhesion. APC mutations occur in most colorectal cancers and typically result in truncation of the C-terminal half of the protein. Results In order to investigate the biophysical properties of APC, we have generated a set of monoclonal antibodies which enable purification of recombinant forms of APC. Here we describe the characterisation of these anti-APC monoclonal antibodies (APC-NT) that specifically recognise endogenous APC both in solution and in fixed cells. Full-length APC(1–2843) and cancer-associated, truncated APC proteins, APC(1–1638) and APC(1–1311) were produced in Sf9 insect cells. Conclusions Recombinant APC proteins were purified using a two-step affinity approach using our APC-NT antibodies. The purification of APC proteins provides the basis for detailed structure/function analyses of full-length, cancer-truncated and endogenous forms of the protein. PMID:24156781

The Adenylate Cyclase Toxins of Bacillus anthracis and Bordetella pertussis Promote Th2 Cell Development by Shaping T Cell Antigen Receptor Signaling

PubMed Central

Rossi Paccani, Silvia; Benagiano, Marisa; Capitani, Nagaja; Zornetta, Irene; Ladant, Daniel; Montecucco, Cesare; D'Elios, Mario M.; Baldari, Cosima T.

2009-01-01

The adjuvanticity of bacterial adenylate cyclase toxins has been ascribed to their capacity, largely mediated by cAMP, to modulate APC activation, resulting in the expression of Th2–driving cytokines. On the other hand, cAMP has been demonstrated to induce a Th2 bias when present during T cell priming, suggesting that bacterial cAMP elevating toxins may directly affect the Th1/Th2 balance. Here we have investigated the effects on human CD4+ T cell differentiation of two adenylate cyclase toxins, Bacillus anthracis edema toxin (ET) and Bordetella pertussis CyaA, which differ in structure, mode of cell entry, and subcellular localization. We show that low concentrations of ET and CyaA, but not of their genetically detoxified adenylate cyclase defective counterparts, potently promote Th2 cell differentiation by inducing expression of the master Th2 transcription factors, c-maf and GATA-3. We also present evidence that the Th2–polarizing concentrations of ET and CyaA selectively inhibit TCR–dependent activation of Akt1, which is required for Th1 cell differentiation, while enhancing the activation of two TCR–signaling mediators, Vav1 and p38, implicated in Th2 cell differentiation. This is at variance from the immunosuppressive toxin concentrations, which interfere with the earliest step in TCR signaling, activation of the tyrosine kinase Lck, resulting in impaired CD3ζ phosphorylation and inhibition of TCR coupling to ZAP-70 and Erk activation. These results demonstrate that, notwithstanding their differences in their intracellular localization, which result in focalized cAMP production, both toxins directly affect the Th1/Th2 balance by interfering with the same steps in TCR signaling, and suggest that their adjuvanticity is likely to result from their combined effects on APC and CD4+ T cells. Furthermore, our results strongly support the key role of cAMP in the adjuvanticity of these toxins. PMID:19266022

Curcumin's Effect on Intestinal Inflammation and Tumorigenesis in the ApcMin/+ Mouse

PubMed Central

Davis, J. Mark; McClellan, Jamie L.; Gordon, Benjamin T.; Carmichael, Martin D.

2011-01-01

Curcumin's benefits on tumorigenesis are thought to be mediated by its antiinflammatory activity; however, these effects have not been well characterized in a mouse model of colon cancer. We examined the effects of curcumin on intestinal inflammation in the ApcMin/+ mouse. ApcMin/+ mice were given a placebo or curcumin (2%) diet from 4 to 18 weeks of age (n = 10/group). C57BL/6 mice were used as a wild-type control (n = 10/group). Intestines were analyzed for polyp burden (sections 1, 4, and 5) and for mRNA expression, and concentration of interleukin (IL)-1β, IL-6, tumor necrosis factor-α, and chemokine ligand 2 (CCL2) (sections 2 and 3). Plasma was collected for concentration of CCL2. Curcumin decreased total intestinal polyps by 75% (P < 0.05) in all size categories [>2 mm (65%), 1–2 mm (72%), <1 mm (82%); P < 0.05]. mRNA expression of IL-1β, IL-6, tumor necrosis factor-α, and CCL2 was elevated (P < 0.05) and curcumin blunted this increase (P < 0.05). Protein concentration of IL-1β, IL-6 (section 3), and CCL2 was increased (P < 0.05) and curcumin reduced this response for IL-1β (section 2) and CCL2 (P < 0.05). Curcumin also offset the increase in plasma CCL2 (P < 0.05). The benefits of curcumin in colon cancer may be at least in part mediated by its antiinflammatory activity. PMID:20950131

Strong Antibody Responses Induced by Protein Antigens Conjugated onto the Surface of Lecithin-Based Nanoparticles

PubMed Central

Sloat, Brian R.; Sandoval, Michael A.; Hau, Andrew M.; He, Yongqun; Cui, Zhengrong

2009-01-01

An accumulation of research over the years has demonstrated the utility of nanoparticles as antigen carriers with adjuvant activity. Herein we defined the adjuvanticity of a novel lecithin-based nanoparticle engineered from emulsions. The nanoparticles were spheres of around 200 nm. Model protein antigens, bovine serum albumin (BSA) or Bacillus anthracis protective antigen (PA) protein, were covalently conjugated onto the nanoparticles. Mice immunized with the BSA-conjugated nanoparticles developed strong anti-BSA antibody responses comparable to that induced by BSA adjuvanted with incomplete Freund's adjuvant and 6.5-fold stronger than that induced by BSA adsorbed onto aluminum hydroxide. Immunization of mice with the PA-conjugated nanoparticles elicited a quick, strong, and durable anti-PA antibody response that afforded protection of the mice against a lethal dose of anthrax lethal toxin challenge. The potent adjuvanticity of the nanoparticles was likely due to their ability to move the antigens into local draining lymph nodes, to enhance the uptake of the antigens by antigen-presenting cells (APCs), and to activate APCs. This novel nanoparticle system has the potential to serve as a universal protein-based vaccine carrier capable of inducing strong immune responses. PMID:19729045

Novel association of APC with intermediate filaments identified using a new versatile APC antibody

PubMed Central

Wang, Yang; Azuma, Yoshiaki; Friedman, David B; Coffey, Robert J; Neufeld, Kristi L

2009-01-01

Background As a key player in suppression of colon tumorigenesis, Adenomatous Polyposis Coli (APC) has been widely studied to determine its cellular functions. However, inconsistencies of commercially available APC antibodies have limited the exploration of APC function. APC is implicated in spindle formation by direct interactions with tubulin and microtubule-binding protein EB1. APC also interacts with the actin cytoskeleton to regulate cell polarity. Until now, interaction of APC with the third cytoskeletal element, intermediate filaments, has remained unexamined. Results We generated an APC antibody (APC-M2 pAb) raised against the 15 amino acid repeat region, and verified its reliability in applications including immunoprecipitation, immunoblotting, and immunofluorescence in cultured cells and tissue. Utilizing this APC-M2 pAb, we immunoprecipitated endogenous APC and its binding proteins from colon epithelial cells expressing wild-type APC. Using Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS), we identified 42 proteins in complex with APC, including β-catenin and intermediate filament (IF) proteins lamin B1 and keratin 81. Association of lamin B1 with APC in cultured cells and human colonic tissue was verified by co-immunoprecipitation and colocalization. APC also colocalized with keratins and remained associated with IF proteins throughout a sequential extraction procedure. Conclusion We introduce a versatile APC antibody that is useful for cell/tissue immunostaining, immunoblotting and immunoprecipitation. We also present evidence for interactions between APC and IFs, independent of actin filaments and microtubules. Our results suggest that APC associates with all three major components of the cytoskeleton, thus expanding potential roles for APC in the regulation of cytoskeletal integrity. PMID:19845967

Mechanism of APC/CCDC20 activation by mitotic phosphorylation.

PubMed

Qiao, Renping; Weissmann, Florian; Yamaguchi, Masaya; Brown, Nicholas G; VanderLinden, Ryan; Imre, Richard; Jarvis, Marc A; Brunner, Michael R; Davidson, Iain F; Litos, Gabriele; Haselbach, David; Mechtler, Karl; Stark, Holger; Schulman, Brenda A; Peters, Jan-Michael

2016-05-10

Chromosome segregation and mitotic exit are initiated by the 1.2-MDa ubiquitin ligase APC/C (anaphase-promoting complex/cyclosome) and its coactivator CDC20 (cell division cycle 20). To avoid chromosome missegregation, APC/C(CDC20) activation is tightly controlled. CDC20 only associates with APC/C in mitosis when APC/C has become phosphorylated and is further inhibited by a mitotic checkpoint complex until all chromosomes are bioriented on the spindle. APC/C contains 14 different types of subunits, most of which are phosphorylated in mitosis on multiple sites. However, it is unknown which of these phospho-sites enable APC/C(CDC20) activation and by which mechanism. Here we have identified 68 evolutionarily conserved mitotic phospho-sites on human APC/C bound to CDC20 and have used the biGBac technique to generate 47 APC/C mutants in which either all 68 sites or subsets of them were replaced by nonphosphorylatable or phospho-mimicking residues. The characterization of these complexes in substrate ubiquitination and degradation assays indicates that phosphorylation of an N-terminal loop region in APC1 is sufficient for binding and activation of APC/C by CDC20. Deletion of the N-terminal APC1 loop enables APC/C(CDC20) activation in the absence of mitotic phosphorylation or phospho-mimicking mutations. These results indicate that binding of CDC20 to APC/C is normally prevented by an autoinhibitory loop in APC1 and that its mitotic phosphorylation relieves this inhibition. The predicted location of the N-terminal APC1 loop implies that this loop controls interactions between the N-terminal domain of CDC20 and APC1 and APC8. These results reveal how APC/C phosphorylation enables CDC20 to bind and activate the APC/C in mitosis.

Mechanism of APC/CCDC20 activation by mitotic phosphorylation

PubMed Central

Qiao, Renping; Weissmann, Florian; Yamaguchi, Masaya; Brown, Nicholas G.; VanderLinden, Ryan; Imre, Richard; Jarvis, Marc A.; Brunner, Michael R.; Davidson, Iain F.; Litos, Gabriele; Haselbach, David; Mechtler, Karl; Stark, Holger; Schulman, Brenda A.; Peters, Jan-Michael

2016-01-01

Chromosome segregation and mitotic exit are initiated by the 1.2-MDa ubiquitin ligase APC/C (anaphase-promoting complex/cyclosome) and its coactivator CDC20 (cell division cycle 20). To avoid chromosome missegregation, APC/CCDC20 activation is tightly controlled. CDC20 only associates with APC/C in mitosis when APC/C has become phosphorylated and is further inhibited by a mitotic checkpoint complex until all chromosomes are bioriented on the spindle. APC/C contains 14 different types of subunits, most of which are phosphorylated in mitosis on multiple sites. However, it is unknown which of these phospho-sites enable APC/CCDC20 activation and by which mechanism. Here we have identified 68 evolutionarily conserved mitotic phospho-sites on human APC/C bound to CDC20 and have used the biGBac technique to generate 47 APC/C mutants in which either all 68 sites or subsets of them were replaced by nonphosphorylatable or phospho-mimicking residues. The characterization of these complexes in substrate ubiquitination and degradation assays indicates that phosphorylation of an N-terminal loop region in APC1 is sufficient for binding and activation of APC/C by CDC20. Deletion of the N-terminal APC1 loop enables APC/CCDC20 activation in the absence of mitotic phosphorylation or phospho-mimicking mutations. These results indicate that binding of CDC20 to APC/C is normally prevented by an autoinhibitory loop in APC1 and that its mitotic phosphorylation relieves this inhibition. The predicted location of the N-terminal APC1 loop implies that this loop controls interactions between the N-terminal domain of CDC20 and APC1 and APC8. These results reveal how APC/C phosphorylation enables CDC20 to bind and activate the APC/C in mitosis. PMID:27114510

Neutrophil Extracellular Traps Directly Induce Epithelial and Endothelial Cell Death: A Predominant Role of Histones

PubMed Central

Saffarzadeh, Mona; Juenemann, Christiane; Queisser, Markus A.; Lochnit, Guenter; Barreto, Guillermo; Galuska, Sebastian P.; Lohmeyer, Juergen; Preissner, Klaus T.

2012-01-01

Neutrophils play an important role in innate immunity by defending the host organism against invading microorganisms. Antimicrobial activity of neutrophils is mediated by release of antimicrobial peptides, phagocytosis as well as formation of neutrophil extracellular traps (NET). These structures are composed of DNA, histones and granular proteins such as neutrophil elastase and myeloperoxidase. This study focused on the influence of NET on the host cell functions, particularly on human alveolar epithelial cells as the major cells responsible for gas exchange in the lung. Upon direct interaction with epithelial and endothelial cells, NET induced cytotoxic effects in a dose-dependent manner, and digestion of DNA in NET did not change NET-mediated cytotoxicity. Pre-incubation of NET with antibodies against histones, with polysialic acid or with myeloperoxidase inhibitor but not with elastase inhibitor reduced NET-mediated cytotoxicity, suggesting that histones and myeloperoxidase are responsible for NET-mediated cytotoxicity. Although activated protein C (APC) did decrease the histone-induced cytotoxicity in a purified system, it did not change NET-induced cytotoxicity, indicating that histone-dependent cytotoxicity of NET is protected against APC degradation. Moreover, in LPS-induced acute lung injury mouse model, NET formation was documented in the lung tissue as well as in the bronchoalveolar lavage fluid. These data reveal the important role of protein components in NET, particularly histones, which may lead to host cell cytotoxicity and may be involved in lung tissue destruction. PMID:22389696

T-Cell Receptor- and CD28-induced Vav1 activity is required for the accumulation of primed T cells into antigenic tissue

PubMed Central

David, Rachel; Ma, Liang; Ivetic, Aleksandar; Takesono, Aya; Ridley, Anne J.; Chai, Jian-Guo; Tybulewicz, Victor; Marelli-Berg, Federica M.

2016-01-01

Localization of primed T cells to antigenic tissue is essential for the development of effective immunity. Together with tissue-selective homing molecules, T-cell receptor (TCR)- and CD28-mediated signals have been shown to promote transendothelial migration of specific T cells into non-lymphoid antigen-rich tissue tissue. However, the cellular and molecular requirements for T-cell accumulation to target tissue following their recruitment are largely undefined. The guanine nucleotide exchange factor (GEF) Vav1 has an integral role in coupling TCR and CD28 to signalling pathways that regulate T cell activation and migration. Here, we have investigated the contribution of TCR- and CD28-induced Vav1 activity to the trafficking and localization of primed HY-specific CD4+ T cells to antigenic sites. Severe migratory defects displayed by Vav1-/- T cells in vitro were fully compensated by a combination of shear flow and chemokines, leading to normal recruitment of Vav1-/- T cells in vivo. In contrast, Vav1-/- T-cell retention into antigen-rich tissue was severely impaired, reflecting their inability to engage in sustained TCR- and CD28-mediated interactions with tissue-resident antigen-presenting cells (APCs). This novel function of APC-induced, TCR- and CD28-mediated Vav1 activity in the regulation of effector T-cell immunity highlights its potential as a therapeutic target in T-cell-mediated tissue damage. PMID:19060239

The end of the decline in cervical cancer mortality in Spain: trends across the period 1981-2012.

PubMed

Cervantes-Amat, Marta; López-Abente, Gonzalo; Aragonés, Nuria; Pollán, Marina; Pastor-Barriuso, Roberto; Pérez-Gómez, Beatriz

2015-04-15

In Spain, cervical cancer prevention is based on opportunistic screening, due to the disease's traditionally low incidence and mortality rates. Changes in sexual behaviour, tourism and migration have, however, modified the probability of exposure to human papilloma virus among Spaniards. This study thus sought to evaluate recent cervical cancer mortality trends in Spain. We used annual female population figures and individual records of deaths certified as cancer of cervix, reclassifying deaths recorded as unspecified uterine cancer to correct coding quality problems. Joinpoint models were fitted to estimate change points in trends, as well as the annual (APC) and average annual percentage change. Log-linear Poisson models were also used to study age-period-cohort effects on mortality trends and their change points. 1981 marked the beginning of a decline in cervical cancer mortality (APC(1981-2003): -3.2; 95% CI:-3.4;-3.0) that ended in 2003, with rates reaching a plateau in the last decade (APC2003-2012: 0.1; 95% CI:-0.9; 1.2). This trend, which was observable among women aged 45-46 years (APC(2003-2012): 1.4; 95% CI:-0.1;2.9) and over 65 years (APC(2003-2012): -0.1; 95% CI:-1.9;1.7), was clearest in Spain's Mediterranean and Southern regions. The positive influence of opportunistic screening is not strong enough to further reduce cervical cancer mortality rates in the country. Our results suggest that the Spanish Health Authorities should reform current prevention programmes and surveillance strategies in order to confront the challenges posed by cervical cancer.

Wild-type APC predicts poor prognosis in microsatellite-stable proximal colon cancer.

PubMed

Jorissen, Robert N; Christie, Michael; Mouradov, Dmitri; Sakthianandeswaren, Anuratha; Li, Shan; Love, Christopher; Xu, Zheng-Zhou; Molloy, Peter L; Jones, Ian T; McLaughlin, Stephen; Ward, Robyn L; Hawkins, Nicholas J; Ruszkiewicz, Andrew R; Moore, James; Burgess, Antony W; Busam, Dana; Zhao, Qi; Strausberg, Robert L; Lipton, Lara; Desai, Jayesh; Gibbs, Peter; Sieber, Oliver M

2015-09-15

APC mutations (APC-mt) occur in ∼70% of colorectal cancers (CRCs), but their relationship to prognosis is unclear. APC prognostic value was evaluated in 746 stage I-IV CRC patients, stratifying for tumour location and microsatellite instability (MSI). Microarrays were used to identify a gene signature that could classify APC mutation status, and classifier ability to predict prognosis was examined in an independent cohort. Wild-type APC microsatellite stable (APC-wt/MSS) tumours from the proximal colon showed poorer overall and recurrence-free survival (OS, RFS) than APC-mt/MSS proximal, APC-wt/MSS distal and APC-mt/MSS distal tumours (OS HR⩾1.79, P⩽0.015; RFS HR⩾1.88, P⩽0.026). APC was a stronger prognostic indicator than BRAF, KRAS, PIK3CA, TP53, CpG island methylator phenotype or chromosomal instability status (P⩽0.036). Microarray analysis similarly revealed poorer survival in MSS proximal cancers with an APC-wt-like signature (P=0.019). APC status did not affect outcomes in MSI tumours. In a validation on 206 patients with proximal colon cancer, APC-wt-like signature MSS cases showed poorer survival than APC-mt-like signature MSS or MSI cases (OS HR⩾2.50, P⩽0.010; RFS HR⩾2.14, P⩽0.025). Poor prognosis APC-wt/MSS proximal tumours exhibited features of the sessile serrated neoplasia pathway (P⩽0.016). APC-wt status is a marker of poor prognosis in MSS proximal colon cancer.

Establishment of tumor-associated immunity requires interaction of Heat Shock Proteins with CD91

PubMed Central

Zhou, Yu Jerry; Messmer, Michelle Nicole; Binder, Robert Julian

2014-01-01

Host antitumor adaptive immune responses are generated as a result of the body’s immunosurveillance mechanisms. How the antitumor immune response is initially primed remains unclear, given that soluble tumor antigens generally are quantitatively insufficient for cross-priming and tumors lack the classical pathogen-associated molecular patterns (PAMPs) to activate costimulation and initiate cross-priming. We explored the interaction of the tumor-derived heat-shock proteins (HSP) with their common receptor (CD91) on antigen presenting cells (APCs) as a mechanism for host-priming of T cell-mediated antitumor immunity. Using targeted genetic disruption of the interaction between HSPs and CD19, we demonstrated that specific ablation of CD91 in APCs prevented the establishment of antitumor immunity. The antitumor immunity was also inhibited when the transfer of tumor-derived HSPs to APCs was prevented using an endogenous inhibitor of CD91. Inhibition was manifested in a reduction of cross-presentation of tumor-derived antigenic peptides in the lymph nodes providing a molecular basis for the observed immunity associated with tumor development. Our findings demonstrate that early in tumor development, the HSP-CD91 pathway is critical for the establishment of antitumor immunity. PMID:24778318

α2-Macroglobulin Is a Significant In Vivo Inhibitor of Activated Protein C and Low APC:α2M Levels Are Associated with Venous Thromboembolism.

PubMed

Martos, Laura; Ramón, Luis Andrés; Oto, Julia; Fernández-Pardo, Álvaro; Bonanad, Santiago; Cid, Ana Rosa; Gruber, Andras; Griffin, John H; España, Francisco; Navarro, Silvia; Medina, Pilar

2018-04-01

 Activated protein C (APC) is a major regulator of thrombin formation. Two major plasma inhibitors form complexes with APC, protein C inhibitor (PCI) and α 1 -antitrypsin (α 1 AT), and these complexes have been quantified by specific enzyme-linked immunosorbent assays (ELISAs). Also, complexes of APC with α 2 -macroglobulin (α 2 M) have been observed by immunoblotting. Here, we report an ELISA for APC:α 2 M complexes in plasma.  Plasma samples were pre-treated with dithiothreitol and then with iodoacetamide. The detection range of the newly developed APC:α 2 M assay was 0.031 to 8.0 ng/mL of complexed APC. Following infusions of APC in humans and baboons, complexes of APC with α 2 M, PCI and α 1 AT were quantified. These complexes as well as circulating APC were also measured in 121 patients with a history of venous thromboembolism (VTE) and 119 matched controls.  In all the in vivo experiments, α 2 M was a significant APC inhibitor. The VTE case-control study showed that VTE patients had significantly lower APC:α 2 M and APC levels than the controls ( p  < 0.001). Individuals in the lowest quartile of APC:α 2 M or the lowest quartile of APC had approximately four times more VTE risk than those in the highest quartile of APC:α 2 M or of APC. The risk increased for individuals with low levels of both parameters.  The APC:α 2 M assay reported here may be useful to help monitor the in vivo fate of APC in plasma. In addition, our results show that a low APC:α 2 M level is associated with increased VTE risk. Schattauer GmbH Stuttgart.

Aluminum hydroxide colloid vaccine encapsulated in yeast shells with enhanced humoral and cellular immune responses.

PubMed

Liu, Hui; Jia, Zhenghu; Yang, Chengmao; Song, Mei; Jing, Zhe; Zhao, Yapu; Wu, Zhenzhou; Zhao, Liqing; Wei, Dongsheng; Yin, Zhinan; Hong, Zhangyong

2018-06-01

Aluminum salt (Alum) is one of the most important immune adjuvants approved for use in humans, however it is not suitable for vaccination against various chronic infectious diseases and cancers for not being able to induce cell-mediated (Th1) immunity. Here, we encapsulated an Alum colloid inside β-glucan particles (GPs), which are a type of natural particles derived from the yeast glucan shells, to prepare hybrid GP-Alum (GP-Al) adjuvant particles with a very uniform size of 2-4 μm. These hybrid particles can be used to load antigen proteins through a simple mixing procedure, and can be highly specifically targeted to antigen-presenting cells (APCs) and strongly activate dendritic cells (DCs) maturation and cytokine secretion. In an animal model, they elicit a strong Th1-biased immune response and extremely high antibody titer, and cause marked prophylactic and therapeutic effects against tumors. As Alum has been proven to be a safe adjuvant to induce strong humoral responses and β-glucans are safe for human use, this very uniform hybrid Alum particulate system could have important application as a vaccine carrier to stimulate humoral and cellular immune responses at the same time. Copyright © 2018 Elsevier Ltd. All rights reserved.

Tumour Suppressor Adenomatous Polyposis Coli (APC) localisation is regulated by both Kinesin-1 and Kinesin-2.

PubMed

Ruane, Peter T; Gumy, Laura F; Bola, Becky; Anderson, Beverley; Wozniak, Marcin J; Hoogenraad, Casper C; Allan, Victoria J

2016-06-07

Microtubules and their associated proteins (MAPs) underpin the polarity of specialised cells. Adenomatous polyposis coli (APC) is one such MAP with a multifunctional agenda that requires precise intracellular localisations. Although APC has been found to associate with kinesin-2 subfamily members, the exact mechanism for the peripheral localization of APC remains unclear. Here we show that the heavy chain of kinesin-1 directly interacts with the APC C-terminus, contributing to the peripheral localisation of APC in fibroblasts. In rat hippocampal neurons the kinesin-1 binding domain of APC is required for its axon tip enrichment. Moreover, we demonstrate that APC requires interactions with both kinesin-2 and kinesin-1 for this localisation. Underlining the importance of the kinesin-1 association, neurons expressing APC lacking kinesin-1-binding domain have shorter axons. The identification of this novel kinesin-1-APC interaction highlights the complexity and significance of APC localisation in neurons.

Systemic RNA delivery to dendritic cells exploits antiviral defence for cancer immunotherapy

NASA Astrophysics Data System (ADS)

Kranz, Lena M.; Diken, Mustafa; Haas, Heinrich; Kreiter, Sebastian; Loquai, Carmen; Reuter, Kerstin C.; Meng, Martin; Fritz, Daniel; Vascotto, Fulvia; Hefesha, Hossam; Grunwitz, Christian; Vormehr, Mathias; Hüsemann, Yves; Selmi, Abderraouf; Kuhn, Andreas N.; Buck, Janina; Derhovanessian, Evelyna; Rae, Richard; Attig, Sebastian; Diekmann, Jan; Jabulowsky, Robert A.; Heesch, Sandra; Hassel, Jessica; Langguth, Peter; Grabbe, Stephan; Huber, Christoph; Türeci, Özlem; Sahin, Ugur

2016-06-01

Lymphoid organs, in which antigen presenting cells (APCs) are in close proximity to T cells, are the ideal microenvironment for efficient priming and amplification of T-cell responses. However, the systemic delivery of vaccine antigens into dendritic cells (DCs) is hampered by various technical challenges. Here we show that DCs can be targeted precisely and effectively in vivo using intravenously administered RNA-lipoplexes (RNA-LPX) based on well-known lipid carriers by optimally adjusting net charge, without the need for functionalization of particles with molecular ligands. The LPX protects RNA from extracellular ribonucleases and mediates its efficient uptake and expression of the encoded antigen by DC populations and macrophages in various lymphoid compartments. RNA-LPX triggers interferon-α (IFNα) release by plasmacytoid DCs and macrophages. Consequently, DC maturation in situ and inflammatory immune mechanisms reminiscent of those in the early systemic phase of viral infection are activated. We show that RNA-LPX encoding viral or mutant neo-antigens or endogenous self-antigens induce strong effector and memory T-cell responses, and mediate potent IFNα-dependent rejection of progressive tumours. A phase I dose-escalation trial testing RNA-LPX that encode shared tumour antigens is ongoing. In the first three melanoma patients treated at a low-dose level, IFNα and strong antigen-specific T-cell responses were induced, supporting the identified mode of action and potency. As any polypeptide-based antigen can be encoded as RNA, RNA-LPX represent a universally applicable vaccine class for systemic DC targeting and synchronized induction of both highly potent adaptive as well as type-I-IFN-mediated innate immune mechanisms for cancer immunotherapy.

Sumoylation promotes optimal APC/C Activation and Timely Anaphase.

PubMed

Lee, Christine C; Li, Bing; Yu, Hongtao; Matunis, Michael J

2018-03-08

The Anaphase Promoting Complex/Cyclosome (APC/C) is a ubiquitin E3 ligase that functions as the gatekeeper to mitotic exit. APC/C activity is controlled by an interplay of multiple pathways during mitosis, including the spindle assembly checkpoint (SAC), that are not yet fully understood. Here, we show that sumoylation of the APC4 subunit of the APC/C peaks during mitosis and is critical for timely APC/C activation and anaphase onset. We have also identified a functionally important SUMO interacting motif in the cullin-homology domain of APC2 located near the APC4 sumoylation sites and APC/C catalytic core. Our findings provide evidence of an important regulatory role for SUMO modification and binding in affecting APC/C activation and mitotic exit. © 2018, Lee et al.

Sequestration of CDH1 by MAD2L2 prevents premature APC/C activation prior to anaphase onset

PubMed Central

Listovsky, Tamar

2013-01-01

The switch from activation of the anaphase-promoting complex/cyclosome (APC/C) by CDC20 to CDH1 during anaphase is crucial for accurate mitosis. APC/CCDC20 ubiquitinates a limited set of substrates for subsequent degradation, including Cyclin B1 and Securin, whereas APC/CCDH1 has a broader specificity. This switch depends on dephosphorylation of CDH1 and the APC/C, and on the degradation of CDC20. Here we show, in human cells, that the APC/C inhibitor MAD2L2 also contributes to ensuring the sequential activation of the APC/C by CDC20 and CDH1. In prometaphase, MAD2L2 sequestered free CDH1 away from the APC/C. At the onset of anaphase, MAD2L2 was rapidly degraded by APC/CCDC20, releasing CDH1 to activate the dephosphorylated APC/C. Loss of MAD2L2 led to premature association of CDH1 with the APC/C, early destruction of APC/CCDH1 substrates, and accelerated mitosis with frequent mitotic aberrations. Thus, MAD2L2 helps to ensure a robustly bistable switch between APC/CCDC20 and APC/CCDH1 during the metaphase-to-anaphase transition, thereby contributing to mitotic fidelity. PMID:24100295

APC functions at the centrosome to stimulate microtubule growth.

PubMed

Lui, Christina; Ashton, Cahora; Sharma, Manisha; Brocardo, Mariana G; Henderson, Beric R

2016-01-01

The adenomatous polyposis coli (APC) tumor suppressor is multi-functional. APC is known to localize at the centrosome, and in mitotic cells contributes to formation of the mitotic spindle. To test whether APC contributes to nascent microtubule (MT) growth at interphase centrosomes, we employed MT regrowth assays in U2OS cells to measure MT assembly before and after nocodazole treatment and release. We showed that siRNA knockdown of full-length APC delayed both initial MT aster formation and MT elongation/regrowth. In contrast, APC-mutant SW480 cancer cells displayed a defect in MT regrowth that was unaffected by APC knockdown, but which was rescued by reconstitution of full-length APC. Our findings identify APC as a positive regulator of centrosome MT initial assembly and suggest that this process is disrupted by cancer mutations. We confirmed that full-length APC associates with the MT-nucleation factor γ-tubulin, and found that the APC cancer-truncated form (1-1309) also bound to γ-tubulin through APC amino acids 1-453. While binding to γ-tubulin may help target APC to the site of MT nucleation complexes, additional C-terminal sequences of APC are required to stimulate and stabilize MT growth. Copyright © 2015 Elsevier Ltd. All rights reserved.

Chemopreventive activity of GEN-27, a genistein derivative, in colitis-associated cancer is mediated by p65-CDX2-β-catenin axis

PubMed Central

Wang, Hong; Fan, Huimin; Li, Yan; Wang, Jianing; Zhang, Xu; Lu, Jinrong; Ji, Hui; Hu, Rong

2016-01-01

Nonresolving inflammation in the intestine predisposes individuals to colitis-associated colorectal cancer (CAC), which leads to high morbidity and mortality. Here we show that genistein-27 (GEN-27), a derivative of genistein, inhibited proliferation of human colorectal cancer cells through inhibiting β-catenin activity. Our results showed that GEN-27 increased expressions of adenomatous polyposis coli (APC) and axis inhibition protein 2 (AXIN2), and reduced β-catenin nuclear localization, which resulted from the inhibition of NF-κB/p65 nuclear localization and up-regulation of caudal-related homeobox transcription factor 2 (CDX2). Furthermore, GEN-27 decreased binding of p65 to the silencer region of CDX2 and increased binding of CDX2 to the promoter regions of APC and AXIN2, thus inhibiting the activation of β-catenin induced by TNF-α. Importantly, GEN-27 protected mice from azoxymethane (AOM)/dextran sodium sulfate (DSS)-induced colon carcinogenesis, with reduced mortality, tumor number and tumor volume. Histopathology, immunohistochemistry and flow cytometry revealed that dietary GEN-27 significantly decreased secretion of proinflammatory cytokines and macrophage infiltration. Moreover, GEN-27 inhibited AOM/DSS-induced p65 and β-catenin nuclear translocation, while promoted the expression of CDX2, APC, and AXIN2. Taken together, our findings demonstrate that the anti-proliferation effect of GEN-27 in vitro and the prevention of CAC in vivo is mediated by p65-CDX2-β-catenin axis via inhibiting β-catenin target genes. Our results imply that GEN-27 could be a promising candidate for the chemoprevention of CAC. PMID:26910375

Raft-dependent endocytic movement and intracellular cluster formation during T cell activation triggered by concanavalin A.

PubMed

Yabuuchi, Satomi; Endo, Satoshi; Baek, KeangOk; Hoshino, Kunihide; Tsujino, Yoshio; Vestergaard, Mun'delanji C; Takagi, Masahiro

2017-12-01

Certain food ingredients can stimulate the human immune system. A lectin, concanavalin A (ConA), from Canavalia ensiformis (jack bean) is one of the most well-known food-derived immunostimulants and mediates activation of cell-mediated immunity through T cell proliferation. Generally, T cell activation is known to be triggered by the interaction between T cells and antigen-presenting cells (APCs) via a juxtacrine (contact-dependent) signaling pathway. The mechanism has been well characterized and is referred to as formation of the immunological synapse (IS). We were interested in the mechanism behind the T cell activation by food-derived ConA which might be different from that of T cell activation by APCs. The purpose of this study was to characterize T cell activation by ConA with regard to (i) movement of raft domain, (ii) endocytic vesicular transport, (iii) the cytoskeleton (actin and microtubules), and (iv) cholesterol composition. We found that raft-dependent endocytic movement was important for T cell activation by ConA and this movement was dependent on actin, microtubules, and cholesterol. The T cell signaling mechanism triggered by ConA can be defined as endocrine signaling which is distinct from the activation process triggered by interaction between T cells and APCs by juxtacrine signaling. Therefore, we hypothesized that T cell activation by ConA includes both two-dimensional superficial raft movement on the membrane surface along actin filaments and three-dimensional endocytic movement toward the inside of the cell along microtubules. These findings are important for developing new methods for immune stimulation and cancer therapy based on the function of ConA. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Parkin Regulates Mitosis and Genomic Stability through Cdc20/Cdh1.

PubMed

Lee, Seung Baek; Kim, Jung Jin; Nam, Hyun-Ja; Gao, Bowen; Yin, Ping; Qin, Bo; Yi, Sang-Yeop; Ham, Hyoungjun; Evans, Debra; Kim, Sun-Hyun; Zhang, Jun; Deng, Min; Liu, Tongzheng; Zhang, Haoxing; Billadeau, Daniel D; Wang, Liewei; Giaime, Emilie; Shen, Jie; Pang, Yuan-Ping; Jen, Jin; van Deursen, Jan M; Lou, Zhenkun

2015-10-01

Mutations in the E3 ubiquitin ligase Parkin have been linked to familial Parkinson's disease. Parkin has also been implicated in mitosis through mechanisms that are unclear. Here we show that Parkin interacts with anaphase promoting complex/cyclosome (APC/C) coactivators Cdc20 and Cdh1 to mediate the degradation of several key mitotic regulators independent of APC/C. We demonstrate that ordered progression through mitosis is orchestrated by two distinct E3 ligases through the shared use of Cdc20 and Cdh1. Furthermore, Parkin is phosphorylated and activated by polo-like kinase 1 (Plk1) during mitosis. Parkin deficiency results in overexpression of its substrates, mitotic defects, genomic instability, and tumorigenesis. These results suggest that the Parkin-Cdc20/Cdh1 complex is an important regulator of mitosis. Copyright © 2015 Elsevier Inc. All rights reserved.

KIR3DL1 interaction with HLA-B27 is altered by ankylosing spondylitis associated ERAP1 and enhanced by MHC class I cross-linking.

PubMed

Abdullah, Hasan; Zhang, Zhenbo; Yee, Kirby; Haroon, Nigil

2015-01-01

Ankylosing spondylitis (AS) is a chronic, inflammatory arthritis of the spine and peripheral joints linked to the antigen presenting molecule HLA-B27. The risk of AS is increased in patients possessing endoplasmic reticulum aminopeptidase-1 (ERAP1) polymorphisms rs30187 and rs27044 encoding amino acid changes K528R and Q730E, respectively. Dysfunction of ERAP1 is hypothesized to cause changes in expression of HLA-B27 classical (pHLA) and non-classical (FHC) conformers on antigen presenting cells (APCs), which interact with the natural killer (NK) cell receptor KIR3DL1. Dysregulation of this pathway may be pathogenic in AS. APC cell lines expressing HLA-B27 were found to inhibit cytokine production in KIR3DL1+ NK cells due to decreased APC-NK cell adhesion, and possibly activation of receptor down-regulation. Blocking pHLA and FHC reveals that both conformers inhibit cytokine production through KIR3DL1. KIR3DL1 affinity and HLA-B27 surface expression studies suggest that ERAP1 R528 and E730 expression protects from AS by generating sub-optimal pHLA, causing reduced KIR3DL1 affinity and weaker cytokine inhibition. Secondarily we observed that KIR3DL1 binding to C1R-B27 APCs is enhanced by blocking pHLA, but not FHC, raising the possibility that antibody mediated HLA-B27 cross-linking may be important in enhancing KIR3DL1+ NK cell function. This study establishes the role of both FHC and pHLA in modulating NK cell cytokine secretion and adhesion functions by interacting with KIR3DL1. This interaction varies depending on the AS association status of the ERAP1 variant expressed in APCs. Additionally antibody cross-linking of HLA-B27 enhances KIR3DL1 binding and as such could be an important pathogenic mechanism in AS.

Tumour Suppressor Adenomatous Polyposis Coli (APC) localisation is regulated by both Kinesin-1 and Kinesin-2

PubMed Central

Ruane, Peter T.; Gumy, Laura F.; Bola, Becky; Anderson, Beverley; Wozniak, Marcin J.; Hoogenraad, Casper C.; Allan, Victoria J.

2016-01-01

Microtubules and their associated proteins (MAPs) underpin the polarity of specialised cells. Adenomatous polyposis coli (APC) is one such MAP with a multifunctional agenda that requires precise intracellular localisations. Although APC has been found to associate with kinesin-2 subfamily members, the exact mechanism for the peripheral localization of APC remains unclear. Here we show that the heavy chain of kinesin-1 directly interacts with the APC C-terminus, contributing to the peripheral localisation of APC in fibroblasts. In rat hippocampal neurons the kinesin-1 binding domain of APC is required for its axon tip enrichment. Moreover, we demonstrate that APC requires interactions with both kinesin-2 and kinesin-1 for this localisation. Underlining the importance of the kinesin-1 association, neurons expressing APC lacking kinesin-1-binding domain have shorter axons. The identification of this novel kinesin-1-APC interaction highlights the complexity and significance of APC localisation in neurons. PMID:27272132

Low-Volatility Agent Permeation (LVAP) Verification and Validation Report

DTIC Science & Technology

2015-05-01

8196 BQL 9v Latex–vapor 8233 BQL 15 Latex 8202 BQL 15v Latex–vapor 8236 BQL 17 APC01 8204 BQL 17v APC01–vapor 8237 BQL 30 APC01 8217 BQL 30v APC01...BQL 9 Latex–NC 8233 BQL 11 Latex 8234 BQL 12 APC01 8235 BQL 15 Latex–NC 8236 BQL 17 APC01–NC 8237 BQL 22 APC01 8238 BQL 23 Latex 8239 BQL 30

Article processing charges for open access publication—the situation for research intensive universities in the USA and Canada

PubMed Central

Björk, Bo-Christer

2016-01-01

Background. Open access (OA) publishing via article processing charges (APCs) is growing as an alternative to subscription publishing. The Pay It Forward (PIF) Project is exploring the feasibility of transitioning from paying subscriptions to funding APCs for faculty at research intensive universities. Estimating of the cost of APCs for the journals authors at research intensive universities tend to publish is essential for the PIF project and similar initiatives. This paper presents our research into this question. Methods. We identified APC prices for publications by authors at the 4 research intensive United States (US) and Canadian universities involved in the study. We also obtained APC payment records from several Western European universities and funding agencies. Both data sets were merged with Web of Science (WoS) metadata. We calculated the average APCs for articles and proceedings in 13 discipline categories published by researchers at research intensive universities. We also identified 41 journals published by traditionally subscription publishers which have recently converted to APC funded OA and recorded the APCs they charge. Results. We identified 7,629 payment records from the 4 European APC payment databases and 14,356 OA articles authored by PIF partner university faculty for which we had listed APC prices. APCs for full OA journals published by PIF authors averaged 1,775 USD; full OA journal APCs paid by Western European funders averaged 1,865 USD; hybrid APCs paid by Western European funders averaged 2,887 USD. The APC for converted journals published by major subscription publishers averaged 1,825 USD. APC funded OA is concentrated in the life and basic sciences. APCs funded articles in the social sciences and humanities are often multidisciplinary and published in journals such as PLOS ONE that largely publish in the life sciences. Conclusions. Full OA journal APCs average a little under 2,000 USD while hybrid articles average about 3,000 USD for publications by researchers at research intensive universities. There is a lack of information on discipline differences in APCs due to the concentration of APC funded publications in a few fields and the multidisciplinary nature of research. PMID:27547569

Adapting photosynthesis to the near-infrared: non-covalent binding of phycocyanobilin provides an extreme spectral red-shift to phycobilisome core-membrane linker from Synechococcus sp. PCC7335.

PubMed

Miao, Dan; Ding, Wen-Long; Zhao, Bao-Qing; Lu, Lu; Xu, Qian-Zhao; Scheer, Hugo; Zhao, Kai-Hong

2016-06-01

Phycobiliproteins that bind bilins are organized as light-harvesting complexes, phycobilisomes, in cyanobacteria and red algae. The harvested light energy is funneled to reaction centers via two energy traps, allophycocyanin B and the core-membrane linker, ApcE1 (conventional ApcE). The covalently bound phycocyanobilin (PCB) of ApcE1 absorbs near 660 nm and fluoresces near 675 nm. In cyanobacteria capable of near infrared photoacclimation, such as Synechococcus sp. PCC7335, there exist even further spectrally red shifted components absorbing >700 nm and fluorescing >710 nm. We expressed the chromophore domain of the extra core-membrane linker from Synechococcus sp. PCC7335, ApcE2, in E. coli together with enzymes generating the chromophore, PCB. The resulting chromoproteins, PCB-ApcE2(1-273) and the more truncated PCB-ApcE2(24-245), absorb at 700 nm and fluoresce at 714 nm. The red shift of ~40 nm compared with canonical ApcE1 results from non-covalent binding of the chromophore by which its full conjugation length including the Δ3,3(1) double bond is preserved. The extreme spectral red-shift could not be ascribed to exciton coupling: dimeric PCB-ApcE2(1-273) and monomeric-ApcE2(24-245) absorbed and fluoresced similarly. Chromophorylation of ApcE2 with phycoerythrobilin- or phytochromobilin resulted in similar red shifts (absorption at 615 and 711 nm, fluorescence at 628 or 726 nm, respectively), compared to the covalently bound chromophores. The self-assembled non-covalent chromophorylation demonstrates a novel access to red and near-infrared emitting fluorophores. Brightly fluorescent biomarking was exemplified in E. coli by single-plasmid transformation. Copyright © 2016 Elsevier B.V. All rights reserved.

Structural basis for the recognition of Asef by adenomatous polyposis coli

PubMed Central

Zhang, Zhenyi; Chen, Leyi; Gao, Lei; Lin, Kui; Zhu, Liang; Lu, Yang; Shi, Xiaoshan; Gao, Yuan; Zhou, Jing; Xu, Ping; Zhang, Jian; Wu, Geng

2012-01-01

Adenomatous polyposis coli (APC) regulates cell-cell adhesion and cell migration through activating the APC-stimulated guanine nucleotide-exchange factor (GEF; Asef), which is usually autoinhibited through the binding between its Src homology 3 (SH3) and Dbl homology (DH) domains. The APC-activated Asef stimulates the small GTPase Cdc42, which leads to decreased cell-cell adherence and enhanced cell migration. In colorectal cancers, truncated APC constitutively activates Asef and promotes cancer cell migration and angiogenesis. Here, we report crystal structures of the human APC/Asef complex. We find that the armadillo repeat domain of APC uses a highly conserved surface groove to recognize the APC-binding region (ABR) of Asef, conformation of which changes dramatically upon binding to APC. Key residues on APC and Asef for the complex formation were mutated and their importance was demonstrated by binding and activity assays. Structural superimposition of the APC/Asef complex with autoinhibited Asef suggests that the binding between APC and Asef might create a steric clash between Asef-DH domain and APC, which possibly leads to a conformational change in Asef that stimulates its GEF activity. Our structures thus elucidate the molecular mechanism of Asef recognition by APC, as well as provide a potential target for pharmaceutical intervention against cancers. PMID:21788986

Differential activation of human T cells to allogeneic endothelial cells, epithelial cells and fibroblasts in vitro

PubMed Central

2012-01-01

Background In the direct pathway, T cells recognize intact donor major histocompatability complexes and allogeneic peptide on the surface of donor antigen presenting cells (APCs). Indirect allorecognition results from the recognition of processed alloantigen by self MHC complexes on self APCs. In this study, we wished to evaluate the relative contribution of different intragraft cells to the alloactivation of nave and memory T cells though the direct and the indirect pathway of allorecognition. Methods The processing of membrane fragments from IFN-treated single donor endothelial cells (EC), fibroblasts or renal epithelial cells (RPTEC) was evaluated by DiOC labeling of each cell type and flow cytometry following interaction with PBMC. Direct pathway activation of nave CD45RA+ or memory CD45RO+ CD4+ T cells was evaluated following coculture with IFN-treated and MHC class II-expressing EC, fibroblasts or RPTEC. Indirect pathway activation was assessed using CD45RA+ or CD45RO+ CD4+ T cells cocultured with autologous irradiated APCs in the absence or presence of sonicates derived from IFN-treated allogeneic EC, fibroblasts or RPTEC. Activation of T cells was assessed by [3H]thymidine incorporation and by ELISpot assays. Results We find that CD14+ APCs readily acquire membrane fragments from fibroblasts and RPTEC, but fail to acquire membrane fragments from intact EC. However, APCs process membranes from EC undergoing apoptosis.There was a notable direct pathway alloproliferative response of CD45RO+ CD4+ T cells to IFN-treated EC, but not to fibroblasts or RPTEC. Also, there was a minimal direct pathway response of CD45RA+ CD4+ T cells to all cell types. In contrast, we found that both CD45RA+ and CD45RO+ CD4+ T cells proliferated following coculture with autologous APCs in the presence of sonicates derived from IFN-treated EC, fibroblasts or RPTEC. By ELISpot, we found that these T cells stimulated via the indirect pathway also produced the cytokines IFN, IL-2, IL-4 and IL-5. Conclusions Recipient APCs may readily process membrane fragments from allogeneic intragraft cells, but not from EC unless they are undergoing apoptosis. This processing is sufficient for indirect pathway alloactivation of both CD45RA+ and CD45RO+ CD4+ T cells. Only graft vascular EC mediate direct pathway reactivation of CD4+ T cells. PMID:23369287

Occult progression by Apc-deficient intestinal crypts as a target for chemoprevention

PubMed Central

Liskay, R.Michael

2014-01-01

Although Apc mutation is widely considered an initiating event in colorectal cancer, little is known about the earliest stages of tumorigenesis following sporadic Apc loss. Therefore, we have utilized a novel mouse model that facilitates the sporadic inactivation of Apc via frameshift reversion of Cre in single, isolated cells and subsequently tracks the fates of Apc-deficient intestinal cells. Our results suggest that consistent with Apc being a ‘gatekeeper’, loss of Apc early in life during intestinal growth leads to adenomas or increased crypt fission, manifested by fields of mutant but otherwise normal-appearing crypts. In contrast, Apc loss occurring later in life has minimal consequences, with mutant crypts being less prone to either increased crypt fission or adenoma formation. Using the stem cell-specific Lgr5-CreER mouse, we generated different sized fields of Apc-deficient crypts via independent recombination events and found that field size correlates with progression to adenoma. To evaluate this early stage prior to adenoma formation as a therapeutic target, we examined the chemopreventive effects of sulindac on Apc-deficient occult crypt fission. We found that sulindac treatment started early in life inhibits the morphologically occult spread of Apc-deficient crypts and thus reduces adenoma numbers. Taken together these results suggest that: (i) earlier Apc loss promotes increased crypt fission, (ii) a field of Apc-deficient crypts, which can form via occult crypt fission or independent neighboring events, is an important intermediate between loss of Apc and adenoma formation and (iii) normal-appearing Apc-deficient crypts are potential unappreciated targets for cancer screening and chemoprevention. PMID:23996931

The APC tumor suppressor is required for epithelial cell polarization and three-dimensional morphogenesis

PubMed Central

Lesko, Alyssa C.; Goss, Kathleen H.; Yang, Frank F.; Schwertner, Adam; Hulur, Imge; Onel, Kenan; Prosperi, Jenifer R.

2015-01-01

The Adenomatous Polyposis Coli (APC) tumor suppressor has been previously implicated in the control of apical-basal polarity; yet, the consequence of APC loss-of-function in epithelial polarization and morphogenesis has not been characterized. To test the hypothesis that APC is required for the establishment of normal epithelial polarity and morphogenesis programs, we generated APC-knockdown epithelial cell lines. APC depletion resulted in loss of polarity and multi-layering on permeable supports, and enlarged, filled spheroids with disrupted polarity in 3D culture. Importantly, these effects of APC knockdown were independent of Wnt/β-catenin signaling, but were rescued with either full-length or a carboxy (c)-terminal segment of APC. Moreover, we identified a gene expression signature associated with APC knockdown that points to several candidates known to regulate cell-cell and cell-matrix communication. Analysis of epithelial tissues from mice and humans carrying heterozygous APC mutations further support the importance of APC as a regulator of epithelial behavior and tissue architecture. These data also suggest that the initiation of epithelial-derived tumors as a result of APC mutation or gene silencing may be driven by loss of polarity and dysmorphogenesis. PMID:25578398

Functions of the APC tumor suppressor protein dependent and independent of canonical WNT signaling: implications for therapeutic targeting.

PubMed

Hankey, William; Frankel, Wendy L; Groden, Joanna

2018-03-01

The acquisition of biallelic mutations in the APC gene is a rate-limiting step in the development of most colorectal cancers and occurs in the earliest lesions. APC encodes a 312-kDa protein that localizes to multiple subcellular compartments and performs diverse functions. APC participates in a cytoplasmic complex that promotes the destruction of the transcriptional licensing factor β-catenin; APC mutations that abolish this function trigger constitutive activation of the canonical WNT signaling pathway, a characteristic found in almost all colorectal cancers. By negatively regulating canonical WNT signaling, APC counteracts proliferation, promotes differentiation, facilitates apoptosis, and suppresses invasion and tumor progression. APC further antagonizes canonical WNT signaling by interacting with and counteracting β-catenin in the nucleus. APC also suppresses tumor initiation and progression in the colorectal epithelium through functions that are independent of canonical WNT signaling. APC regulates the mitotic spindle to facilitate proper chromosome segregation, localizes to the cell periphery and cell protrusions to establish cell polarity and appropriate directional migration, and inhibits DNA replication by interacting directly with DNA. Mutations in APC are often frameshifts, insertions, or deletions that introduce premature stop codons and lead to the production of truncated APC proteins that lack its normal functions and possess tumorigenic properties. Therapeutic approaches in development for the treatment of APC-deficient tumors are focused on the inhibition of canonical WNT signaling, especially through targets downstream of APC in the pathway, or on the restoration of wild-type APC expression.

[Preliminary studies on physicochemical properties of Angelica sinensis polysaccharide-iron complex].

PubMed

Wang, Kai-ping; Zhang, Yu; Dai, Li-quan

2006-05-01

To study some physicochemical properties of Angelica sinensis polysaccharide-iron complex (APC). Based on the qualitatively identified reactions of iron (III), the qualitatively identified reactions of APC were found out by comparing hydroxide. The content of iron (III) in APC was determined with iodometry. The stability of APC under physiological pH conditions was judged by titrating APC with sodium hydroxide. The deoxidization of APC was tested with colorimetric analysis. APC showed the qualitatively identified reactions of iron (III). The content of iron (III) in APC ranged from 10% to 40%, and the water-solubility of APC was related to the content of iron (III). The complex was stable at physiological pH from 3 to 12, without precipitation and dissociation. At 37 degrees C, Fe (III) in the complex was completely reduced to Fe (III) by ascorbic acid in about 6 hours. APC can be qualitatively identified by using the qualitatively identified reactions of iron (III). When its iron (III) content is within 20%-25%, APC has a better ability to dissolve in water. And the complex is stable under physiological pH conditions.

Comparison of Notch Strength between Gr/PEEK (APC-1 and APC-2) and Gr/Epoxy Composite Materials at Elevated Temperature.

DTIC Science & Technology

1985-12-01

J ub. we Jr. Captain, USARt Z712 AFIT/GAE/AA/85D- 12 Iv COMPARISON OF NOTCH STRENGTH BETWEEN GR/PEEK (APC-1 AND APC-2) AND GR/EPOXY COMPOSITE ...85D-12 COMPARISON OF NOTCH STRENGTH BETWEEN GR/PEEK _ (APC-1 AND APC-2) AND GR/EPOXY COMPOSITE MATERIAL AT ELEVATED TEMPERATURE THESIS Presented to the...unlimited Preface In this experimental investigation, the reduction of strength for notched composite laminates of Aromatic Polymer Composite , APC-2

Functions of the APC tumor suppressor protein dependent and independent of canonical WNT signaling: Implications for therapeutic targeting

PubMed Central

Hankey, William; Frankel, Wendy L.

2018-01-01

The acquisition of biallelic mutations in the APC gene is a rate-limiting step in the development of most colorectal cancers and occurs in the earliest lesions. APC encodes a 312-kDa protein that localizes to multiple subcellular compartments and performs diverse functions. APC participates in a cytoplasmic complex that promotes the destruction of the transcriptional licensing factor β-catenin; APC mutations that abolish this function trigger constitutive activation of the canonical WNT signaling pathway, a characteristic found in almost all colorectal cancers. By negatively regulating canonical WNT signaling, APC counteracts proliferation, promotes differentiation, facilitates apoptosis and suppresses invasion and tumor progression. APC further antagonizes canonical WNT signaling by interacting with and counteracting β-catenin in the nucleus. APC also suppresses tumor initiation and progression in the colorectal epithelium through functions that are independent of canonical WNT signaling. APC regulates the mitotic spindle to facilitate proper chromosome segregation, localizes to the cell periphery and cell protrusions to establish cell polarity and appropriate directional migration, and inhibits DNA replication by interacting directly with DNA. Mutations in APC are often frameshifts, insertions or deletions that introduce premature stop codons and lead to the production of truncated APC proteins that lack its normal functions and possess tumorigenic properties. Therapeutic approaches in development for the treatment of APC-deficient tumors are focused on the inhibition of canonical WNT signaling, especially through targets downstream of APC in the pathway, or on the restoration of wild-type APC expression. PMID:29318445

Ablating the aryl hydrocarbon receptor (AhR) in CD11c+ cells perturbs intestinal epithelium development and intestinal immunity.

PubMed

Chng, Song Hui; Kundu, Parag; Dominguez-Brauer, Carmen; Teo, Wei Ling; Kawajiri, Kaname; Fujii-Kuriyama, Yoshiaki; Mak, Tak Wah; Pettersson, Sven

2016-04-12

Diet and microbiome derived indole derivatives are known to activate the ligand induced transcription factor, the Aryl hydrocarbon Receptor (AhR). While the current understanding of AhR biology has confirmed its role in mucosal lymphocytes, its function in intestinal antigen presenting cells (APCs) is poorly understood. Here, we report that Cre-mediated deletion of AhR in CD11c-expressing cells in C57/BL6 mice is associated with altered intestinal epithelial morphogenesis in vivo. Moreover, when co-cultured with AhR-deficient DCs ex vivo, intestinal organoids showed reduced SRY (sex determining region Y)-box 9 and increased Mucin 2 expression, which correlates with reduced Paneth cells and increased goblet cell differentiation, similar to the data obtained in vivo. Further, characterization of intestinal APC subsets, devoid of AhR, revealed an expression pattern associated with aberrant intrinsic Wnt pathway regulation. At a functional level, the loss of AhR in APCs resulted in a dysfunctional epithelial barrier, associated with a more aggressive chemically induced colitis compared to wild type animals. Our results are consistent with a model whereby the AhR signalling pathway may participate in the regulation of innate immunity through intestinal epithelium development and mucosal immunity.

Evaluation of the cancer chemopreventive efficacy of rice bran in genetic mouse models of breast, prostate and intestinal carcinogenesis.

PubMed

Verschoyle, R D; Greaves, P; Cai, H; Edwards, R E; Steward, W P; Gescher, A J

2007-01-29

Brown rice is a staple dietary constituent in Asia, whereas rice consumed in the Western world is generally white, obtained from brown rice by removal of the bran. We tested the hypothesis that rice bran interferes with development of tumours in TAg, TRansgenic Adenocarcinoma of the Mouse Prostate (TRAMP) or Apc(Min) mice, genetic models of mammary, prostate and intestinal carcinogenesis, respectively. Mice received rice bran (30%) in AIN-93G diet throughout their post-weaning lifespan. In TAg and TRAMP mice, rice bran did not affect carcinoma development. In TRAMP or wild-type C57Bl6/J mice, dietary rice bran increased kidney weight by 18 and 20%, respectively. Consumption of rice bran reduced numbers of intestinal adenomas in Apc(Min) mice by 51% (P<0.01), compared to mice on control diet. In parallel, dietary rice bran decreased intestinal haemorrhage in these mice, as reflected by increased haematocrit. At 10% in the diet, rice bran did not significantly retard Apc(Min) adenoma development. Likewise, low-fibre rice bran (30% in the diet) did not affect intestinal carcinogenesis, suggesting that the fibrous constituents of the bran mediate chemopreventive efficacy. The results suggest that rice bran might be beneficially evaluated as a putative chemopreventive intervention in humans with intestinal polyps.

Central Tolerance to Tissue-specific Antigens Mediated by Direct and Indirect Antigen Presentation

PubMed Central

Gallegos, Alena M.; Bevan, Michael J.

2004-01-01

Intrathymic expression of tissue-specific antigens (TSAs) by medullary thymic epithelial cells (Mtecs) leads to deletion of autoreactive T cells. However, because Mtecs are known to be poor antigen-presenting cells (APCs) for tolerance to ubiquitous antigens, and very few Mtecs express a given TSA, it was unclear if central tolerance to TSA was induced directly by Mtec antigen presentation or indirectly by thymic bone marrow (BM)-derived cells via cross-presentation. We show that professional BM-derived APCs acquire TSAs from Mtecs and delete autoreactive CD8 and CD4 T cells. Although direct antigen presentation by Mtecs did not delete the CD4 T cell population tested in this study, Mtec presentation efficiently deleted both monoclonal and polyclonal populations of CD8 T cells. For developing CD8 T cells, deletion by BM-derived APC and by Mtec presentation occurred abruptly at the transitional, CD4high CD8low TCRintermediate stage, presumably as the cells transit from the cortex to the medulla. These studies reveal a cooperative relationship between Mtecs and BM-derived cells in thymic elimination of autoreactive T cells. Although Mtecs synthesize TSAs and delete a subset of autoreactive T cells, BM-derived cells extend the range of clonal deletion by cross-presenting antigen captured from Mtecs. PMID:15492126

PI3Kδ promotes CD4(+) T-cell interactions with antigen-presenting cells by increasing LFA-1 binding to ICAM-1.

PubMed

Garçon, Fabien; Okkenhaug, Klaus

2016-05-01

Activation of T lymphocytes by peptide/major histocompatibility complex on antigen-presenting cells (APCs) involves dynamic contacts between the two cells, during which T cells undergo marked morphological changes. These interactions are facilitated by integrins. Activation of the T cells increases the binding of the integrin lymphocyte function-associated antigen 1 (LFA-1) expressed by T cells to intercellular adhesion molecule (ICAM)-1 and ICAM-2 expressed by APCs. The signalling pathways that control integrin affinities are incompletely defined. The phosphoinositide 3-kinases (PI3Ks) generate second-messenger signalling molecules that control cell growth, proliferation, differentiation and trafficking. Here we show that in T cells, PI3Kδ attenuates the activation of Rac1, but sustains the activation of Rap1. Consequently, PI3Kδ increases LFA-1-dependent adhesion to form stable conjugates with APCs. Increased Rap1 activity and LFA-1 adhesion were only in part mediated by the downstream kinase Akt, suggesting the involvement of additional phosphatidylinositol(3,4,5)P3-binding proteins. These results establish a link between PI3K activity, cytoskeletal changes and integrin binding and help explain the impaired T-cell-dependent immune responses in PI3Kδ-deficient mice.

CD40 agonist antibody mediated improvement of chronic Cryptosporidium infection in patients with X-linked hyper IgM syndrome

USDA-ARS?s Scientific Manuscript database

X-linked hyper-IgM syndrome (XHM) is a combined immune deficiency disorder caused by mutations in CD40 ligand. We tested CP-870,893, a human CD40 agonist monoclonal antibody, in the treatment of two XHM patients with biliary Cryptosporidiosis. CP-870,893 activated B cells and APCs in vitro, restori...

Hepatitis B viral X protein interacts with tumor suppressor adenomatous polyposis coli to activate Wnt/β-catenin signaling.

PubMed

Hsieh, Antony; Kim, Hyeon-Seop; Lim, Seung-Oe; Yu, Dae-Yeul; Jung, Guhung

2011-01-28

HBV X protein is a transactivator of several cellular signaling pathways including Wnt which contributes to HBV associated neoplasia. The Wnt/β-catenin pathway is associated with HCC-initiating cells. Here we perform a functional screen for host factors involved in the transactivational properties of HBx. We identify adenomatous polyposis coli (APC) as a binding partner of HBx and further determine that HBx competitively binds APC to displace β-catenin from its degradation complex. This results in β-catenin upregulation in the nucleus and the activation of Wnt signaling. We show that Wnt inhibitors curcumin and quercetin target downstream β-catenin activity and effectively repress HBx-mediated regulation of c-MYC and E-cadherin. Our results provide a pathological mechanism of HBx induced malignant transformation. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

40 CFR 272.201 - Arkansas State-administered program: Final authorization.

Code of Federal Regulations, 2011 CFR

2011-07-01

...) Arkansas Pollution Control and Ecology (APC&E) Commission Regulation No. 23, Hazardous Waste Management, as... Three, Sections 19 and 21, 22; Chapter Five, Section 28. (x) Arkansas Pollution Control and Ecology (APC... Ecology (APC&E) Commission, Regulation No. 8, Administrative Procedures, June 12, 2000. (3) The following...

40 CFR 272.201 - Arkansas State-administered program: Final authorization.

Code of Federal Regulations, 2013 CFR

2013-07-01

...) Arkansas Pollution Control and Ecology (APC&E) Commission Regulation No. 23, Hazardous Waste Management, as... Three, Sections 19 and 21, 22; Chapter Five, Section 28. (x) Arkansas Pollution Control and Ecology (APC... Ecology (APC&E) Commission, Regulation No. 8, Administrative Procedures, June 12, 2000. (3) The following...

40 CFR 272.201 - Arkansas State-administered program: Final authorization.

Code of Federal Regulations, 2014 CFR

2014-07-01

...) Arkansas Pollution Control and Ecology (APC&E) Commission Regulation No. 23, Hazardous Waste Management, as... Three, Sections 19 and 21, 22; Chapter Five, Section 28. (x) Arkansas Pollution Control and Ecology (APC... Ecology (APC&E) Commission, Regulation No. 8, Administrative Procedures, June 12, 2000. (3) The following...

40 CFR 272.201 - Arkansas State-administered program: Final authorization.

Code of Federal Regulations, 2012 CFR

2012-07-01

...) Arkansas Pollution Control and Ecology (APC&E) Commission Regulation No. 23, Hazardous Waste Management, as... Three, Sections 19 and 21, 22; Chapter Five, Section 28. (x) Arkansas Pollution Control and Ecology (APC... Ecology (APC&E) Commission, Regulation No. 8, Administrative Procedures, June 12, 2000. (3) The following...

Selective targeting of mutant adenomatous polyposis coli (APC) in colorectal cancer.

PubMed

Zhang, Lu; Theodoropoulos, Panayotis C; Eskiocak, Ugur; Wang, Wentian; Moon, Young-Ah; Posner, Bruce; Williams, Noelle S; Wright, Woodring E; Kim, Sang Bum; Nijhawan, Deepak; De Brabander, Jef K; Shay, Jerry W

2016-10-19

Mutations in the adenomatous polyposis coli (APC) gene are common in colorectal cancer (CRC), and more than 90% of those mutations generate stable truncated gene products. We describe a chemical screen using normal human colonic epithelial cells (HCECs) and a series of oncogenically progressed HCECs containing a truncated APC protein. With this screen, we identified a small molecule, TASIN-1 (truncated APC selective inhibitor-1), that specifically kills cells with APC truncations but spares normal and cancer cells with wild-type APC. TASIN-1 exerts its cytotoxic effects through inhibition of cholesterol biosynthesis. In vivo administration of TASIN-1 inhibits tumor growth of CRC cells with truncated APC but not APC wild-type CRC cells in xenograft models and in a genetically engineered CRC mouse model with minimal toxicity. TASIN-1 represents a potential therapeutic strategy for prevention and intervention in CRC with mutant APC. Copyright © 2016, American Association for the Advancement of Science.

Germline APC mutations in hepatoblastoma.

PubMed

Yang, Adeline; Sisson, Rebecca; Gupta, Anita; Tiao, Greg; Geller, James I

2018-04-01

Conflicting reports on the frequency of germline adenomatous polyposis coli (APC) gene mutations in patients with hepatoblastoma (HB) have called into question the clinical value of APC mutation testing on apparently sporadic HB. An Institutional Review Board approved retrospective review of clinical data collected from patients with HB who received APC testing at our institution was conducted. All HB patients seen at Cincinnati Children's Hospital Medical Center were eligible for testing. Potential genotype/phenotype correlations were assessed. As of July 2015, 29 patients with HB had received constitutional APC testing. Four (14%) were found to have APC pathogenic truncations of the APC protein and in addition two (7%) had APC missense variants of unknown clinical significance. Two patients (7%) had family histories indicative of familial adenomatous polyposis (FAP). Response to chemotherapy tracked differently in APC pathogenic cases, with a slower imaging response despite an equivalent or slightly faster α-fetoprotein (AFP) response. The prevalence of pathogenic APC variants in apparently sporadic HB may be higher than previously detected. Differences in time to imaging response, despite similar AFP response, may impact surgical planning. All patients with HB warrant germline APC mutation testing for underlying FAP. © 2017 Wiley Periodicals, Inc.

The distinct spectra of tumor-associated Apc mutations in mismatch repair-deficient Apc1638N mice define the roles of MSH3 and MSH6 in DNA repair and intestinal tumorigenesis.

PubMed

Kuraguchi, M; Yang, K; Wong, E; Avdievich, E; Fan, K; Kolodner, R D; Lipkin, M; Brown, A M; Kucherlapati, R; Edelmann, W

2001-11-01

In mammalian cells, mismatch recognition has been attributed to two partially redundant heterodimeric protein complexes of MutS homologues, MSH2-MSH3 and MSH2-MSH6. We have conducted a comparative analysis of Msh3 and Msh6 deficiency in mouse intestinal tumorigenesis by generating Apc1638N mice deficient in Msh3, Msh6 or both. We have found that Apc1638N mice defective in Msh6 show reduced survival and a 6-7-fold increase in intestinal tumor multiplicity. In contrast, Msh3-deficient Apc1638N mice showed no difference in survival and intestinal tumor multiplicity as compared with Apc1638N mice. However, when Msh3 deficiency is combined with Msh6 deficiency (Msh3(-/-)Msh6(-/-)Apc1638N), the survival rate of the mice was further reduced compared to Msh6(-/-)Apc(1638N) mice because of a high multiplicity of intestinal tumors at a younger age. Almost 90% of the intestinal tumors from both Msh6(-/-)Apc1638N and Msh3(-/-)Msh6(-/-)Apc1638N mice contained truncation mutations in the wild-type Apc allele. Apc mutations in Msh6(-/-)Apc1638N mice consisted predominantly of base substitutions (93%) creating stop codons, consistent with a major role for Msh6 in the repair of base-base mismatches. However, in Msh3(-/-)Msh6(-/-)Apc1638N tumors, we observed a mixture of base substitutions (46%) and frameshifts (54%), indicating that in Msh6(-/-)Apc1638N mice frameshift mutations in the Apc gene were suppressed by Msh3. Interestingly, all except one of the Apc mutations detected in mismatch repair-deficient intestinal tumors were located upstream of the third 20-amino acid beta-catenin binding repeat and before all of the Ser-Ala-Met-Pro repeats, suggesting that there is selection for loss of multiple domains involved in beta-catenin regulation. Our analysis therefore has revealed distinct mutational spectra and clarified the roles of Msh3 and Msh6 in DNA repair and intestinal tumorigenesis.

Atrial ectopic activity in cryptogenic ischemic stroke and TIA: a risk factor for recurrence.

PubMed

Pinho, João; Braga, Carlos Galvão; Rocha, Sofia; Santos, Ana Filipa; Gomes, André; Cabreiro, Ana; Magalhães, Sónia; Ferreira, Carla

2015-02-01

To characterize atrial ectopic activity in patients with cryptogenic ischemic stroke (CIS) or transient ischemic attack (TIA) and determine its prognostic significance. Retrospective cohort study, in which 184 patients with CIS or TIA who had performed 24-hour Holter electrocardiogram were included. The median follow-up was 27.5 months. Baseline clinical and imagiologic characteristics, etiologic investigation results, and ischemic stroke and TIA recurrences information were collected. Number of atrial premature complexes (APCs) per hour was categorized as less than 10 APCs/hour, 10-30 APCs/hour, and more than 30 APCs/hour. Most of the patients had less than 10 APCs/hour (82.6%), 8.2% had 10-30 APCs/hour, and 9.2% had more than 30 APCs/hour. Patients with more than 30 APCs/hour had a greater median left atrium diameter than patients with 30 APCs/hour or less (42 mm vs. 38 mm; 95% confidence interval [CI], .50-7.00; P = .003). Annual recurrence rate of CIS or TIA was 2.9% in patients with less than 10 APCs/hour, 11.0% in 10-30 APCs/hour, and 22.6% in more than 30 APCs/hour (P = .001). More than 30 APCs/hour were independently associated with recurrence risk in multivariate survival analysis (hazard ratio, 3.40; 95% CI, 1.12-10.32; P = .030). In patients with CIS or TIA, frequent atrial ectopic activity (>30 APCs/h) was independently associated with increased risk of stroke or TIA recurrence. Further studies need to validate frequent atrial ectopic activity as a risk factor for recurrence in cryptogenic stroke and confirm its role as a predictor of occult atrial fibrillation. Copyright © 2015 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Curcumin modifies Apc(min) apoptosis resistance and inhibits 2-amino 1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) induced tumour formation in Apc(min) mice.

PubMed

Collett, G P; Robson, C N; Mathers, J C; Campbell, F C

2001-05-01

Curcumin, the active ingredient of the rhizome of Curcuma longa, promotes apoptosis and may have chemopreventive properties. This study investigates the effects of curcumin on apoptosis and tumorigenesis in male Apc(min) mice treated with the human dietary carcinogen, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP). Intestinal epithelial apoptotic index in response to PhIP treatment was approximately twice as great in the wild-type C57BL/6 APC(+/+) strain than in Apc(min) mice (3.7% Apc(+/+) versus 1.9% Apc(min); P < 0.001). PhIP promoted tumour formation in Apc(min) proximal small intestine (4.6 tumours per mouse, PhIP treated versus 2.1 tumours per mouse, control untreated; P < 0.05). Curcumin enhanced PhIP-induced apoptosis (4.0% curcumin + PhIP versus 2.1% PhIP alone; P < 0.01) and inhibited PhIP-induced tumorigenesis in the proximal small intestine of Apc(min) mice (2.2 tumours per mouse, curcumin + PhIP versus 4.6 tumours per mouse PhIP alone; P < 0.05). This study shows that the Apc(min) genotype is associated with resistance to PhIP-induced apoptosis in intestinal epithelium. Curcumin attenuates Apc(min) resistance to PhIP-induced apoptosis and inhibits PhIP-induced tumorigenesis in proximal Apc(min) mouse small intestine.

Tumor suppressor gene adenomatous polyposis coli downregulates intestinal transport.

PubMed

Rexhepaj, Rexhep; Rotte, Anand; Gu, Shuchen; Michael, Diana; Pasham, Venkanna; Wang, Kan; Kempe, Daniela S; Ackermann, Teresa F; Brücher, Björn; Fend, Falko; Föller, Michael; Lang, Florian

2011-05-01

Loss of function mutations of the tumor suppressor gene adenomatous polyposis coli (APC) underly the familial adenomatous polyposis. Mice carrying an inactivating mutation in the apc gene (apc (Min/+)) similarly develop intestinal polyposis. APC is effective at least in part by degrading β-catenin and lack of APC leads to markedly enhanced cellular β-catenin levels. β-Catenin has most recently been shown to upregulate the Na+/K+ ATPase. The present study, thus, explored the possibility that APC could influence intestinal transport. The abundance and localization of β-catenin were determined utilizing Western blotting and confocal microscopy, the activity of the electrogenic glucose carrier (SGLT1) was estimated from the glucose-induced current in jejunal segments utilizing Ussing chamber experiments and the Na+/H+ exchanger (NHE3) activity from Na+ -dependent re-alkalinization of cytosolic pH (ΔpH(i)) following an ammonium pulse employing BCECF fluorescence. As a result, β-catenin abundance in intestinal tissue was significantly higher in apc (Min/+) mice than in wild-type mice (apc (+/+)). The β-catenin protein was localized in the basolateral membrane. Both, the glucose-induced current and ΔpH(i) were significantly higher in apc (Min/+) mice than in apc (+/+) mice. In conclusion, intestinal electrogenic transport of glucose and intestinal Na+/H+ exchanger activity are both significantly enhanced in apc (Min/+) mice, pointing to a role of APC in the regulation of epithelial transport.

KCTD1 Suppresses Canonical Wnt Signaling Pathway by Enhancing β-catenin Degradation

PubMed Central

Wang, Fangmei; Huang, Wenhuan; Liang, Zhongheng; Xiao, Yuzhong; Wei, Ke; Wan, Zhenxing; Hu, Xiang; Xiang, Shuanglin; Ding, Xiaofeng; Zhang, Jian

2014-01-01

The canonical Wnt signaling pathway controls normal embryonic development, cellular proliferation and growth, and its aberrant activity results in human carcinogenesis. The core component in regulation of this pathway is β-catenin, but molecular regulation mechanisms of β-catenin stability are not completely known. Here, our recent studies have shown that KCTD1 strongly inhibits TCF/LEF reporter activity. Moreover, KCTD1 interacted with β-catenin both in vivo by co-immunoprecipitation as well as in vitro through GST pull-down assays. We further mapped the interaction regions to the 1-9 armadillo repeats of β-catenin and the BTB domain of KCTD1, especially Position Ala-30 and His-33. Immunofluorescence analysis indicated that KCTD1 promotes the cytoplasmic accumulation of β-catenin. Furthermore, protein stability assays revealed that KCTD1 enhances the ubiquitination/degradation of β-catenin in a concentration-dependent manner in HeLa cells. And the degradation of β-catenin mediated by KCTD1 was alleviated by the proteasome inhibitor, MG132. In addition, KCTD1-mediated β-catenin degradation was dependent on casein kinase 1 (CK1)- and glycogen synthase kinase-3β (GSK-3β)-mediated phosphorylation and enhanced by the E3 ubiquitin ligase β-transducin repeat-containing protein (β-TrCP). Moreover, KCTD1 suppressed the expression of endogenous Wnt downstream genes and transcription factor AP-2α. Finally, we found that Wnt pathway member APC and tumor suppressor p53 influence KCTD1-mediated downregulation of β-catenin. These results suggest that KCTD1 functions as a novel inhibitor of Wnt signaling pathway. PMID:24736394

Drosophila homologues of adenomatous polyposis coli (APC) and the formin diaphanous collaborate by a conserved mechanism to stimulate actin filament assembly.

PubMed

Jaiswal, Richa; Stepanik, Vince; Rankova, Aneliya; Molinar, Olivia; Goode, Bruce L; McCartney, Brooke M

2013-05-10

Vertebrate APC collaborates with Dia through its Basic domain to assemble actin filaments. Despite limited sequence homology between the vertebrate and Drosophila APC Basic domains, Drosophila APC1 collaborates with Dia to stimulate actin assembly in vitro. The mechanism of actin assembly is highly conserved over evolution. APC-Dia collaborations may be crucial in a wide range of animal cells. Adenomatous polyposis coli (APC) is a large multidomain protein that regulates the cytoskeleton. Recently, it was shown that vertebrate APC through its Basic domain directly collaborates with the formin mDia1 to stimulate actin filament assembly in the presence of nucleation barriers. However, it has been unclear whether these activities extend to homologues of APC and Dia in other organisms. Drosophila APC and Dia are each required to promote actin furrow formation in the syncytial embryo, suggesting a potential collaboration in actin assembly, but low sequence homology between the Basic domains of Drosophila and vertebrate APC has left their functional and mechanistic parallels uncertain. To address this question, we purified Drosophila APC1 and Dia and determined their individual and combined effects on actin assembly using both bulk fluorescence assays and total internal reflection fluorescence microscopy. Our data show that APC1, similar to its vertebrate homologue, bound to actin monomers and nucleated and bundled filaments. Further, Drosophila Dia nucleated actin assembly and protected growing filament barbed ends from capping protein. Drosophila APC1 and Dia directly interacted and collaborated to promote actin assembly in the combined presence of profilin and capping protein. Thus, despite limited sequence homology, Drosophila and vertebrate APCs exhibit highly related activities and mechanisms and directly collaborate with formins. These results suggest that APC-Dia interactions in actin assembly are conserved and may underlie important in vivo functions in a broad range of animal phyla.

Activated protein C promotes breast cancer cell migration through interactions with EPCR and PAR-1

PubMed Central

Beaulieu, Lea M.; Church, Frank C.

2014-01-01

Activated protein C (APC) is a serine protease that regulates thrombin (IIa) production through inactivation of blood coagulation factors Va and VIIIa. APC also has non-hemostatic functions related to inflammation, proliferation, and apoptosis through various mechanisms. Using two breast cancer cell lines, MDA-MB-231 and MDA-MB-435, we investigated the role of APC in cell chemotaxis and invasion. Treatment of cells with increasing APC concentrations (1–50 μg/ml) increased invasion and chemotaxis in a concentration-dependent manner. Only the active form of APC increased invasion and chemotaxis of the MDA-MB-231 cells when compared to 3 inactive APC derivatives. Using a modified “checkerboard” analysis, APC was shown to only affect migration when plated with the cells; therefore, APC is not a chemoattractant. Blocking antibodies to endothelial protein C receptor (EPCR) and protease-activated receptor-1 (PAR-1) attenuated the effects of APC on chemotaxis in the MDA-MB-231 cells. Finally, treatment of the MDA-MB-231 cells with the proliferation inhibitor, Na butyrate, showed that APC did not increase migration by increasing cell number. Therefore, APC increases invasion and chemotaxis of cells by binding to the cell surface and activating specific signaling pathways through EPCR and PAR-1. PMID:17254565

APC hypermethylation for early diagnosis of colorectal cancer: a meta-analysis and literature review.

PubMed

Liang, Tie-Jun; Wang, Hong-Xu; Zheng, Yan-Yan; Cao, Ying-Qing; Wu, Xiaoyu; Zhou, Xin; Dong, Shu-Xiao

2017-07-11

Adenomatous polyposis coli (APC) promoter hypermethylation has been frequently observed in colorectal cancer (CRC). The association between APC promoter methylation and clinicopathological significance in CRC is under investigation. We performed a meta-analysis to quantitatively evaluate the significance of APC methylation in CRC. The study included a total of 24 articles and 2025 CRC patients. The frequency of APC promoter hypermethylation was significantly higher in colorectal adenoma than in normal colorectal tissue, OR was 5.76, 95% CI, 2.45-13.56; p<0.0001, I2=0%. APC promoter more frequently hypermethylated in CRC stage I compared to normal colorectal tissue, OR was 13.42, 95% CI, 3.66-49.20; p<0.0001, I2=31%. The risk of incidence of CRC was significantly correlated to APC promoter hypermethylation, pooled OR was 9.80, 95%CI, 6.07-15.81; p<0.00001, I2=43%. APC methylation was not associated with grade, stage of CRC as well as tumor location, patients' gender, and smoking behavior. The results indicate that APC promoter hypermethylation is an early event in carcinogenesis of CRC, could be a valuable diagnostic marker for early-stage CRC. APC methylation is not significantly associated with overall survival in patients with CRC. APC is a potential drug target for development of personalized treatment.

Epigenetic regulation of APC in the molecular pathogenesis of gallbladder cancer.

PubMed

Tekcham, Dinesh Singh; Poojary, Satish S; Bhunia, Shushruta; Barbhuiya, Mustafa Ahmed; Gupta, Sanjeev; Shrivastav, Braj Raj; Tiwari, Pramod Kumar

2016-05-01

Loss of function of adenomatous polyposis coli (APC) has been reported in cancer. The two promoters of APC, 1A and 1B also have roles in cancer. But, the epigenetic role of APC promoters is not yet clear in gallbladder cancer (GBC) and gallstone diseases (GSD). We undertook this study to determine the epigenetic role of APC in GBC and GSD. Methylation-specific (MS)-PCR was used to analyze the methylation of APC gene. The expression of APC gene was studied by semi-quantitative PCR, real-time PCR and immunohistochemistry (IHC) in GBC, GSD and adjacent normal tissues. Of the two promoters, APC 1A promoter was found methylated in 96 per cent GBC ( P=0.0155) and 80 per cent GSD (P=0.015). Exon 1 was downregulated in grade II (P=0.002) and grade III (P=0.0001) of GBC, while exon 2 was normally expressed. Scoring analysis of IHC revealed 0 or negativity in 34.48 per cent (P=0.057) and 1+ in 24.14 per cent (P=0.005) GBC cases suggesting loss of APC expression. The present findings indicate epigenetic silencing of APC in advanced GBC. The methylation pattern, followed by expression analysis of APC may be suggested for diagnostic, prognostic and therapeutic purposes in GBC in future.

Molecular basis of APC/C regulation by the spindle assembly checkpoint

PubMed Central

Zhang, Ziguo; Yang, Jing; Maslen, Sarah; Skehel, Mark; Barford, David

2016-01-01

In the dividing eukaryotic cell the spindle assembly checkpoint (SAC) ensures each daughter cell inherits an identical set of chromosomes. The SAC coordinates the correct attachment of sister chromatid kinetochores to the mitotic spindle with activation of the anaphase-promoting complex/cyclosome (APC/C), the E3 ubiquitin ligase that initiates chromosome separation. In response to unattached kinetochores, the SAC generates the mitotic checkpoint complex (MCC), a multimeric assembly that inhibits the APC/C, delaying chromosome segregation. Here, using cryo-electron microscopy we determined the near-atomic resolution structure of an APC/C-MCC complex (APC/CMCC). We reveal how degron-like sequences of the MCC subunit BubR1 block degron recognition sites on Cdc20, the APC/C coactivator subunit (Cdc20APC/C) responsible for substrate interactions. BubR1 also obstructs binding of UbcH10 (APC/C’s initiating E2) to repress APC/C ubiquitination activity. Conformational variability of the complex allows for UbcH10 association, and we show from a structure of APC/CMCC in complex with UbcH10 how the Cdc20 subunit intrinsic to the MCC (Cdc20MCC) is ubiquitinated, a process that results in APC/C reactivation when the SAC is silenced. PMID:27509861

Measuring APC/C-Dependent Ubiquitylation In Vitro.

PubMed

Jarvis, Marc A; Brown, Nicholas G; Watson, Edmond R; VanderLinden, Ryan; Schulman, Brenda A; Peters, Jan-Michael

2016-01-01

The anaphase-promoting complex/cyclosome (APC/C) is a 1.2 MDa ubiquitin ligase complex with important functions in both proliferating and post-mitotic differentiated cells. In proliferating cells, APC/C controls cell cycle progression by targeting inhibitors of chromosome segregation and mitotic exit for degradation by the 26S proteasome. To understand how APC/C recruits and ubiquitylates its substrate proteins and how these processes are controlled, it is essential to analyze APC/C activity in vitro. In the past, such experiments have been limited by the fact that large quantities of purified APC/C were difficult to obtain and that mutated versions of the APC/C could not be easily generated. In this chapter we review recent advances in generating and purifying recombinant forms of the human APC/C and its co-activators, using methods that are scalable and compatible with mutagenesis. We also describe a method that allows the quantitative analysis of APC/C activity using fluorescently labeled substrate proteins.

Peptidomimetic inhibitors of APC-Asef interaction block colorectal cancer migration.

PubMed

Jiang, Haiming; Deng, Rong; Yang, Xiuyan; Shang, Jialin; Lu, Shaoyong; Zhao, Yanlong; Song, Kun; Liu, Xinyi; Zhang, Qiufen; Chen, Yu; Chinn, Y Eugene; Wu, Geng; Li, Jian; Chen, Guoqiang; Yu, Jianxiu; Zhang, Jian

2017-09-01

The binding of adenomatous polyposis coli (APC) to its receptor Asef relieves the negative intramolecular regulation of Asef and leads to aberrant cell migration in human colorectal cancer. Because of its crucial role in metastatic dissemination, the interaction between APC and Asef is an attractive target for anti-colorectal-cancer therapy. We rationally designed a series of peptidomimetics that act as potent inhibitors of the APC interface. Crystal structures and biochemical and cellular assays showed that the peptidomimetics in the APC pocket inhibited the migration of colorectal cells by disrupting APC-Asef interaction. By using the peptidomimetic inhibitor as a chemical probe, we found that CDC42 was the downstream GTPase involved in APC-stimulated Asef activation in colorectal cancer cells. Our work demonstrates the feasibility of exploiting APC-Asef interaction to regulate the migration of colorectal cancer cells, and provides what to our knowledge is the first class of protein-protein interaction inhibitors available for the development of cancer therapeutics targeting APC-Asef signaling.

Critical role for invariant chain in CD1d-mediated selection and maturation of Vα14-invariant NKT cells.

PubMed

Sillé, Fenna C M; Martin, Constance; Jayaraman, Pushpa; Rothchild, Alissa; Besra, Gurdyal S; Behar, Samuel M; Boes, Marianne

2011-09-30

The development and maturation of Vα14 invariant (i)NKT cells in mice requires CD1d-mediated lipid antigen presentation in the thymus and the periphery. Cortical thymocytes mediate positive selection, while professional APCs are involved in thymic negative selection and in terminal maturation of iNKT cells in the periphery. CD1d requires entry in the endosomal pathway to allow antigen acquisition for assembly as lipid/CD1d complexes for display to iNKT cells. This process involves tyrosine-based sorting motifs in the CD1d cytoplasmic tail and invariant chain (Ii) that CD1d associates with in the endoplasmic reticulum. The function of Ii in iNKT cell thymic development and peripheral maturation had not been fully understood. Using mice deficient in Ii and the Ii-processing enzyme cathepsin S (catS), we addressed this question. Ii(-/-) mice but not catS(-/-) mice developed significantly fewer iNKT cells in thymus, that were less mature as measured by CD44 and NK1.1 expression. Ii(-/-) mice but not catS(-/-) mice developed fewer Vβ7(+) cells in their iNKT TCR repertoire than WT counterparts, indicative of a change in endogenous glycolipid antigen/CD1d-mediated iNKT cell selection. Finally, using a Mycobacterium tuberculosis infection model in macrophages, we show that iNKT developed in Ii(-/-) but not catS(-/-) mice have defective effector function. Our data support a role for professional APCs expressing Ii, but no role for catS in the thymic development and peripheral terminal maturation of iNKT cells. Copyright © 2011 Elsevier B.V. All rights reserved.

APC alterations are frequently involved in the pathogenesis of acinar cell carcinoma of the pancreas, mainly through gene loss and promoter hypermethylation.

PubMed

Furlan, Daniela; Sahnane, Nora; Bernasconi, Barbara; Frattini, Milo; Tibiletti, Maria Grazia; Molinari, Francesca; Marando, Alessandro; Zhang, Lizhi; Vanoli, Alessandro; Casnedi, Selenia; Adsay, Volkan; Notohara, Kenji; Albarello, Luca; Asioli, Sofia; Sessa, Fausto; Capella, Carlo; La Rosa, Stefano

2014-05-01

Genetic and epigenetic alterations involved in the pathogenesis of pancreatic acinar cell carcinomas (ACCs) are poorly characterized, including the frequency and role of gene-specific hypermethylation, chromosome aberrations, and copy number alterations (CNAs). A subset of ACCs is known to show alterations in the APC/β-catenin pathway which includes mutations of APC gene. However, it is not known whether, in addition to mutation, loss of APC gene function can occur through alternative genetic and epigenetic mechanisms such as gene loss or promoter methylation. We investigated the global methylation profile of 34 tumor suppressor genes, CNAs of 52 chromosomal regions, and APC gene alterations (mutation, methylation, and loss) together with APC mRNA level in 45 ACCs and related peritumoral pancreatic tissues using methylation-specific multiplex ligation probe amplification (MS-MLPA), fluorescence in situ hybridization (FISH), mutation analysis, and reverse transcription-droplet digital PCR. ACCs did not show an extensive global gene hypermethylation profile. RASSF1 and APC were the only two genes frequently methylated. APC mutations were found in only 7 % of cases, while APC loss and methylation were more frequently observed (48 and 56 % of ACCs, respectively). APC mRNA low levels were found in 58 % of cases and correlated with CNAs. In conclusion, ACCs do not show extensive global gene hypermethylation. APC alterations are frequently involved in the pathogenesis of ACCs mainly through gene loss and promoter hypermethylation, along with reduction of APC mRNA levels.

Correlation between the methylation of APC gene promoter and colon cancer.

PubMed

Li, Bing-Qiang; Liu, Peng-Peng; Zhang, Cai-Hua

2017-08-01

The present study was planned to explore the correlation between the methylation of APC (adenomatous polyposis coli) and colon carcinogenesis. Colon cancer tissues and tumor-adjacent normal tissues of 60 colon cancer patients (who received surgical operation in our hospital from January 2012 to December 2014) were collected. SW1116 cells in human colon cancer tissues were selected for culturing. 5-aza-2c-deoxycytidine (5-aza-dC) was utilized as an inhibitor of the methylation for APC gene. Methylation specific PCR (MSP) was utilized for detection of APC methylation in SW1116 cells. The MTT and Transwell assays were performed to detect the effect of the methylation of APC gene on the proliferation and invasive abilities of SW1116 cells. The correlation between the methylation of APC gene and pathological parameters of colon cancer patients was analyzed. MSP results revealed that 41 cases (68.33%) showed methylation of APC gene in colon cancer tissues. No methylation of APC gene was found in tumor-adjacent normal tissues. 5-aza-dC was able to inhibit the methylation of APC gene in SW1116 cells. APC gene methylation was correlated with tumor size, differentiation degree, lymph node metastasis and Dukes staging. In conclusion, the levels of the methylation of APC in colon cancer tissues and SW1116 cells are relatively high. The methylation of APC promoted the proliferation and invasion abilities of SW1116 cells. Furthermore, methylation is correlated with a variety of clinicopathological features of colon cancer patients.

High dose infusion of activated protein C (rhAPC) fails to improve neuronal damage and cognitive deficit after global cerebral ischemia in rats.

PubMed

Brückner, Melanie; Lasarzik, Irina; Jahn-Eimermacher, Antje; Peetz, Dirk; Werner, Christian; Engelhard, Kristin; Thal, Serge C

2013-09-13

Recent studies demonstrated anticoagulatory, antiinflammatory, antiapoptotic, and neuroprotective properties of activated protein C (APC) in rodent models of acute neurodegenerative diseases, suggesting APC as promising broad acting therapeutic agent. Unfortunately, continuous infusion of recombinant human APC (rhAPC) failed to improve brain damage following cardiac arrest in rats. The present study was designed to investigate the neuroprotective effect after global cerebral ischemia (GI) with an optimized infusion protocol. Rats were subjected to bilateral clip occlusion of the common carotid arteries (BCAO) and controlled hemorrhagic hypotension to 40 mm Hg for 14 min and a subsequent 5h-infusion of rhAPC (2mg/kg bolus+6 mg/kg/h continuous IV) or vehicle (0.9% NaCl). The dosage was calculated to maintain plasma hAPC activity at 150%. Cerebral inflammation, apoptosis and neuronal survival was determined at day 10. rhAPC infusion did not influence cortical cerebral perfusion during reperfusion and failed to reduce neuronal cell loss, microglia activation, and caspase 3 activity. Even an optimized rhAPC infusion protocol designed to maintain a high level of APC plasma activity failed to improve the sequels following GI. Despite positive reports about protective effects of APC following, e.g., ischemic stroke, the present study supports the notion that infusion of APC during the early reperfusion phase does not result in sustained neuroprotection and fails to improve outcome after global cerebral ischemia. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

MET Signaling Mediates Intestinal Crypt-Villus Development, Regeneration, and Adenoma Formation and Is Promoted by Stem Cell CD44 Isoforms.

PubMed

Joosten, Sander P J; Zeilstra, Jurrit; van Andel, Harmen; Mijnals, R Clinton; Zaunbrecher, Joost; Duivenvoorden, Annet A M; van de Wetering, Marc; Clevers, Hans; Spaargaren, Marcel; Pals, Steven T

2017-10-01

Resistance of metastatic human colorectal cancer cells to drugs that block epidermal growth factor (EGF) receptor signaling could be caused by aberrant activity of other receptor tyrosine kinases, activating overlapping signaling pathways. One of these receptor tyrosine kinases could be MET, the receptor for hepatocyte growth factor (HGF). We investigated how MET signaling, and its interaction with CD44 (a putative MET coreceptor regulated by Wnt signaling and highly expressed by intestinal stem cells [ISCs] and adenomas) affects intestinal homeostasis, regeneration, and adenoma formation in mini-gut organoids and mice. We established organoid cultures from ISCs stimulated with HGF or EGF and assessed intestinal differentiation by immunohistochemistry. Mice with total epithelial disruption of MET (Ah Cre /Met fl/fl /LacZ) or ISC-specific disruption of MET (Lgr5 Creert2 /Met fl/fl /LacZ) and control mice (Ah Cre /Met +/+ /LacZ, Lgr5 Creert2 /Met +/+ /LacZ) were exposed to 10 Gy total body irradiation; intestinal tissues were collected, and homeostasis and regeneration were assessed by immunohistochemistry. We investigated adenoma organoid expansion stimulated by HGF or EGF using adenomas derived from Lgr5 Creert2 /Met fl/fl /Apc fl/fl and Lgr5 Creert2 /Met +/+ /Apc fl/fl mice. The same mice were evaluated for adenoma prevalence and size. We also quantified adenomas in Ah Cre /Met fl/fl /Apc fl/+ mice compared with Ah Cre /Met +/+ /Apc fl/+ control mice. We studied expansion of organoids generated from crypts and adenomas, stimulated by HGF or EGF, that were derived from mice expressing different CD44 splice variants (Cd44 +/+ , Cd44 -/- , Cd44 s/s , or Cd44 v4-10/v4-10 mice). Crypts incubated with EGF or HGF expanded into self-organizing mini-guts with similar levels of efficacy and contained all differentiated cell lineages. MET-deficient mice did not have defects in intestinal homeostasis. Total body irradiation reduced numbers of proliferating crypts in Ah Cre /Met fl/fl /LacZ mice. Lgr5 Creert2 /Met fl/fl /LacZ mice had impaired regeneration of MET-deficient ISCs. Adenoma organoids stimulated with EGF or HGF expanded to almost twice the size of nonstimulated organoids. MET-deficient adenoma organoids did not respond to HGF stimulation, but did respond to EGF. ISC-specific disruption of Met (Lgr5 Creert2 /Met fl/fl /Apc fl/fl mice) caused a twofold increase in apoptosis in microadenomas, resulting in an approximately 50% reduction of microadenoma numbers and significantly reduced average adenoma size. Total epithelial disruption of Met (Ah Cre /Met fl/fl /Apc fl/+ mice) resulted in an approximate 50% reduction in (micro)adenoma numbers. Intestinal crypts from Cd44 -/- mice did not expand to the same extent as crypts from Cd44 +/+ mice on stimulation with HGF, but had the same response to EGF. The negative effect on HGF-mediated growth was overcome by expression of CD44v4-10, but not by CD44s. Similarly, HGF-mediated expansion of adenoma organoids required CD44v4-10. In studies of intestinal organoid cultures and mice with inducible deletion of MET, we found HGF receptor signaling to regulate intestinal homeostasis and regeneration, as well as adenoma formation. These activities of MET are promoted by the stem cell CD44 isoform CD44v4-10. Our findings provide rationale for targeting signaling via MET and CD44 during anti-EGF receptor therapy of patients with colorectal cancer or in patients resistant to EGF receptor inhibitors. Copyright © 2017 AGA Institute. Published by Elsevier Inc. All rights reserved.

The Anaphase-Promoting Complex is a dual integrator that regulates both microRNA-mediated transcriptional regulation of Cyclin B1 and degradation of Cyclin B1 during Arabidopsis male gametophyte development

USDA-ARS?s Scientific Manuscript database

The anaphase-promoting complex/cyclosome (APC/C), an essential ubiquitin protein ligase, regulates mitotic progression and exit by enhancing degradation of cell cycle regulatory proteins, such as CYCB1;1, whose transcripts are upregulated by DUO POLLEN1 (DUO1). DUO1 is required for cell division in ...

The Anaphase-Promoting Complex Is a Dual Integrator That Regulates Both MicroRNA-Mediated Transcriptional Regulation of Cyclin B1 and Degradation of Cyclin B1 during Arabidopsis Male Gametophyte Development

USDA-ARS?s Scientific Manuscript database

The anaphase-promoting complex/cyclosome (APC/C), an essential ubiquitin protein ligase, regulates mitotic progression and exit by enhancing degradation of cell cycle regulatory proteins, such as CYCB1;1, whose transcripts are upregulated by DUO POLLEN1 (DUO1). DUO1 is required for cell division in ...

Dampened antiviral immunity to intravaginal exposure to RNA viral pathogens allows enhanced viral replication

PubMed Central

Woodruff, Erik M.; Trapecar, Martin; Fontaine, Krystal A.; Ezaki, Ashley; Ott, Melanie

2016-01-01

Understanding the host immune response to vaginal exposure to RNA viruses is required to combat sexual transmission of this class of pathogens. In this study, using lymphocytic choriomeningitis virus (LCMV) and Zika virus (ZIKV) in wild-type mice, we show that these viruses replicate in the vaginal mucosa with minimal induction of antiviral interferon and inflammatory response, causing dampened innate-mediated control of viral replication and a failure to mature local antigen-presenting cells (APCs). Enhancement of innate-mediated inflammation in the vaginal mucosa rescues this phenotype and completely inhibits ZIKV replication. To gain a better understanding of how this dampened innate immune activation in the lower female reproductive tract may also affect adaptive immunity, we modeled CD8 T cell responses using vaginal LCMV infection. We show that the lack of APC maturation in the vaginal mucosa leads to a delay in CD8 T cell activation in the draining lymph node and hinders the timely appearance of effector CD8 T cells in vaginal mucosa, thus further delaying viral control in this tissue. Our study demonstrates that vaginal tissue is exceptionally vulnerable to infection by RNA viruses and provides a conceptual framework for the male to female sexual transmission observed during ZIKV infection. PMID:27852793

Inhibition of CDK7 bypasses spindle assembly checkpoint via premature cyclin B degradation during oocyte meiosis.

PubMed

Wang, HaiYang; Jo, Yu-Jin; Sun, Tian-Yi; Namgoong, Suk; Cui, Xiang-Shun; Oh, Jeong Su; Kim, Nam-Hyung

2016-12-01

To ensure accurate chromosome segregation, the spindle assembly checkpoint (SAC) delays anaphase onset by preventing the premature activation of anaphase-promoting complex/cyclosome (APC/C) until all kinetochores are attached to the spindle. Although an escape from mitosis in the presence of unsatisfied SAC has been shown in several cancer cells, it has not been reported in oocyte meiosis. Here, we show that CDK7 activity is required to prevent a bypass of SAC during meiosis I in mouse oocytes. Inhibition of CDK7 using THZ1 accelerated the first meiosis, leading to chromosome misalignment, lag of chromosomes during chromosome segregation, and a high incidence of aneuploidy. Notably, this acceleration occurred in the presence of SAC proteins including Mad2 and Bub3 at the kinetochores. However, inhibition of APC/C-mediated cyclin B degradation blocked the THZ1-induced premature polar body extrusion. Moreover, chromosomal defects mediated by THZ1 were rescued when anaphase onset was delayed. Collectively, our results show that CDK7 activity is required to prevent premature anaphase onset by suppressing the bypass of SAC, thus ensuring chromosome alignment and proper segregation. These findings reveal new roles of CDK7 in the regulation of meiosis in mammalian oocytes. Copyright © 2016 Elsevier B.V. All rights reserved.

The Spindle Assembly Checkpoint Is Not Essential for Viability of Human Cells with Genetically Lowered APC/C Activity.

PubMed

Wild, Thomas; Larsen, Marie Sofie Yoo; Narita, Takeo; Schou, Julie; Nilsson, Jakob; Choudhary, Chunaram

2016-03-01

The anaphase-promoting complex/cyclosome (APC/C) and the spindle assembly checkpoint (SAC), which inhibits the APC/C, are essential determinants of mitotic timing and faithful division of genetic material. Activation of the APC/C is known to depend on two APC/C-interacting E2 ubiquitin-conjugating enzymes-UBE2C and UBE2S. We show that APC/C activity in human cells is tuned by the combinatorial use of three E2s, namely UBE2C, UBE2S, and UBE2D. Genetic deletion of UBE2C and UBE2S, individually or in combination, leads to discriminative reduction in APC/C function and sensitizes cells to UBE2D depletion. Reduction of APC/C activity results in loss of switch-like metaphase-to-anaphase transition and, strikingly, renders cells insensitive to chemical inhibition of MPS1 and genetic ablation of MAD2, both of which are essential for the SAC. These results provide insights into the regulation of APC/C activity and demonstrate that the essentiality of the SAC is imposed by the strength of the APC/C. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Adenomatous polyposis coli (APC) regulates miR17-92 cluster through β-catenin pathway in colorectal cancer.

PubMed

Li, Yajuan; Lauriola, Mattia; Kim, Donghwa; Francesconi, Mirko; D'Uva, Gabriele; Shibata, Dave; Malafa, Mokenge P; Yeatman, Timothy J; Coppola, Domenico; Solmi, Rossella; Cheng, Jin Q

2016-09-01

Adenomatous polyposis coli (APC) mutation is the most common genetic change in sporadic colorectal cancer (CRC). Although deregulations of miRNAs have been frequently reported in this malignancy, APC-regulated miRNAs have not been extensively documented. Here, by using an APC-inducible cell line and array analysis, we identified a total of 26 deregulated miRNAs. Among them, members of miR-17-92 cluster were dramatically inhibited by APC and induced by enforced expression of β-catenin. Furthermore, we demonstrate that activated β-catenin resulted from APC loss binds to and activates the miR-17-92 promoter. Notably, enforced expression of miR-19a overrides APC tumor suppressor activity, and knockdown of miR-19a in cancer cells with compromised APC function reduced their aggressive features in vitro. Finally, we observed that expression of miR-19a significantly correlates with β-catenin levels in colorectal cancer specimens, and it is associated to the aggressive stage of tumor progression. Thus, our study reveals that miR-17-92 cluster is directly regulated by APC/β-catenin pathway and could be a potential therapeutic target in colon cancers with aberrant APC/β-catenin signaling.

Extensive metabolic disorders are present in APC(min) tumorigenesis mice.

PubMed

Liu, Zhenzhen; Xiao, Yi; Zhou, Zhengxiang; Mao, Xiaoxiao; Cai, Jinxing; Xiong, Lu; Liao, Chaonan; Huang, Fulian; Liu, Zehao; Ali Sheikh, Md Sayed; Plutzky, Jorge; Huang, He; Yang, Tianlun; Duan, Qiong

2016-05-15

Wnt signaling plays essential role in mesenchymal stem cell (MSC) differentiation. Activation of Wnt signaling suppresses adipogenesis, but promotes osteogenesis in MSC. Adenomatous polyposis coli (APC) is a negative regulator of β-catenin and Wnt signaling activity. The mutation of APC gene leads to the activation of Wnt signaling and is responsible for tumorigenesis in APC(min) mouse; however, very few studies focused on its metabolic abnormalities. The present study reports a widespread metabolic disorder phenotype in APC(min) mice. The old APC(min) mice have decreased body weight and impaired adipogenesis, but severe hyperlipidemia, which mimic the phenotypes of Familial Adenomatous Polyposis (FAP), an inherited disease also caused by APC gene mutation in human. We found that the expression of lipid metabolism and free fat acids (FA) use genes in the white adipose tissue (WAT) of the APC(min) mice is much lower than those of control. The changed gene expression pattern may lead to the disability of circulatory lipid transportation and storage at WAT. Moreover, the APC(min) mice could not maintain the core body temperature in cold condition. PET-CT determination revealed that the BAT of APC(min) mice has significantly impaired ability to take up (18)FDG from the blood. Morphological studies identified that the brown adipocytes of APC(min) mice were filled with lipid droplets but fewer mitochondria. These results matched with the findings of impaired BAT function in APC(min) mice. Collectively, our study explores a new mechanism that explains abnormal metabolism in APC(min) mice and provides insights into studying the metabolic disorders of FAP patients. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

76 FR 74121 - Medicare and Medicaid Programs: Hospital Outpatient Prospective Payment; Ambulatory Surgical...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-30

... Radiation Therapy (IMRT) (APC 0305) f. Computed Tomography of Abdomen/Pelvic (APCs 0331 and 0334) g. Complex Interstitial Radiation Source Application (APC 0651) h. Radioelement Applications (APC 0312) 8. Respiratory...

The TLR3/TICAM-1 signal constitutively controls spontaneous polyposis through suppression of c-Myc in Apc Min/+ mice.

PubMed

Ono, Junya; Shime, Hiroaki; Takaki, Hiromi; Takashima, Ken; Funami, Kenji; Yoshida, Sumito; Takeda, Yohei; Matsumoto, Misako; Kasahara, Masanori; Seya, Tsukasa

2017-10-17

Intestinal tumorigenesis is promoted by myeloid differentiation primary response gene 88 (MyD88) activation in response to the components of microbiota in Apc Min/+ mice. Microbiota also contains double-stranded RNA (dsRNA), a ligand for TLR3, which activates the toll-like receptor adaptor molecule 1 (TICAM-1, also known as TRIF) pathway. We established Apc Min/+ Ticam1 -/- mice and their survival was compared to survival of Apc Min/+ Myd88 -/- and wild-type (WT) mice. The properties of polyps were investigated using immunofluorescence staining and RT-PCR analysis. We demonstrate that TICAM-1 is essential for suppression of polyp formation in Apc Min/+ mice. TICAM-1 knockout resulted in shorter survival of mice compared to WT mice or mice with knockout of MyD88 in the Apc Min/+ background. Polyps were more frequently formed in the distal intestine of Apc Min/+ Ticam1 -/- mice than in Apc Min/+ mice. Infiltration of immune cells such as CD11b + and CD8α + cells into the polyps was detected histologically. CD11b and CD8α mRNAs were increased in polyps of Apc Min/+ Ticam1 -/- mice compared to Apc Min/+ mice. Gene expression of inducible nitric oxide synthase (iNOS), interferon (IFN)-γ, CXCL9 and IL-12p40 was increased in polyps of Apc Min/+ Ticam1 -/- mice. mRNA and protein expression of c-Myc, a critical transcription factor for inflammation-associated polyposis, were increased in polyps of Apc Min/+ Ticam1 -/- mice. A Lactobacillus strain producing dsRNA was detected in feces of Apc Min/+ mice. These results imply that the TLR3/TICAM-1 pathway inhibits polyposis through suppression of c-Myc expression and supports long survival in Apc Min/+ mice.

Chir99021 and Valproic acid reduce the proliferative advantage of Apc mutant cells.

PubMed

Langlands, Alistair J; Carroll, Thomas D; Chen, Yu; Näthke, Inke

2018-02-15

More than 90% of colorectal cancers carry mutations in Apc that drive tumourigenesis. A 'just-right' signalling model proposes that Apc mutations stimulate optimal, but not excessive Wnt signalling, resulting in a growth advantage of Apc mutant over wild-type cells. Reversal of this growth advantage constitutes a potential therapeutic approach. We utilised intestinal organoids to compare the growth of Apc mutant and wild-type cells. Organoids derived from Apc Min/+ mice recapitulate stages of intestinal polyposis in culture. They eventually form spherical cysts that reflect the competitive growth advantage of cells that have undergone loss of heterozygosity (LOH). We discovered that this emergence of cysts was inhibited by Chiron99021 and Valproic acid, which potentiates Wnt signalling. Chiron99021 and Valproic acid restrict the growth advantage of Apc mutant cells while stimulating that of wild-type cells, suggesting that excessive Wnt signalling reduces the relative fitness of Apc mutant cells. As a proof of concept, we demonstrated that Chiron99021-treated Apc mutant organoids were rendered susceptible to TSA-induced apoptosis, while wild-type cells were protected.

Different effection of p.1125Val>Ala and rs11954856 in APC on Wnt signaling pathway.

PubMed

Li, Fei-Feng; Zhao, Zhi-Xun; Yan, Peng; Wang, Song; Liu, Zheng; Zhang, Qiong; Zhang, Xiao-Ning; Sun, Chang-Hao; Wang, Xi-Shan; Wang, Gui-Yu; Liu, Shu-Lin

2017-09-19

Colorectal cancer (CRC) is among the most common and fatal forms of solid tumors worldwide and more than two thirds of CRC and adenomas patients have APC gene mutations. APC is a key regulator in the Wnt/β-catenin signaling pathway but its roles in CRC remains to be elucidated. In this study, we compared APC genes between CRC patients and controls to determine possible associations of nucleotide changes in the APC gene with the pathways involved in CRC pathogenesis. All participants received physical and enteroscopic examinations. The APC gene was sequenced for 300 Chinese Han CRC patients and 411 normal controls, and the expression levels of genes in the signaling pathway were analyzed using Western Blotting. Statistical analyses were conducted using SPSS (version 19.0) software. We found that rs11954856 in the APC gene was associated with colorectal cancer and could increase the expression levels of APC , β-catenin , TCF7L1 , TCF7L2 and LEF1 genes in the pathway in the CRC patients, demonstrating the involvement of APC in the pathological processes leading to CRC.

Early diagnostic potential of APC hypermethylation in esophageal cancer.

PubMed

Wang, Bujiang; Song, Haojun; Jiang, Haizhong; Fu, Yangbo; Ding, Xiaoyun; Zhou, Chongchang

2018-01-01

The hypermethylation of APC gene is observed in various cancers, including esophageal cancer (EC). However, the association between APC methylation and the initiation and progression of EC is poorly understood. The current study systematically reviewed studies on abnormal methylation of APC in EC and quantitatively synthesized 18 studies by meta-analysis involving 1008 ECs, 570 Barrett's esophagus (BE), and 782 controls. Our results showed higher methylation of APC in EC (OR = 23.33, P < 0.001) and BE (OR = 9.34, P < 0.001) than in normal controls. Whereas APC methylation in EC was similar to that in BE ( P = 0.052), it was not associated with tumor stage ( P = 0.204). Additionally, APC methylation was not significantly associated with overall survival (OS) and relapse-free survival (RFS) in patients with EC. The performance of APC methylation for the detection of EC and BE achieved areas under the receiver operating characteristic curves of 0.94 and 0.88, respectively. Our results imply that APC methylation detection is a potential diagnostic biomarker for EC and BE.

Epigenetic markers in circulating cell-free DNA as prognostic markers for survival of castration-resistant prostate cancer patients.

PubMed

Hendriks, Rianne J; Dijkstra, Siebren; Smit, Frank P; Vandersmissen, Johan; Van de Voorde, Hendrik; Mulders, Peter F A; van Oort, Inge M; Van Criekinge, Wim; Schalken, Jack A

2018-04-01

Noninvasive biomarkers to guide personalized treatment for castration-resistant prostate cancer (CRPC) are needed. In this study, we analyzed hypermethylation patterns of two genes (GSTP1 and APC) in plasma cell-free DNA (cfDNA) of CRPC patients. The aim of this study was to analyze the cfDNA concentrations and levels of the epigenetic markers and to assess the value of these biomarkers for prognosis. In this prospective study, patients were included before starting new treatment after developing CRPC. The blood samples were collected prior to start of the treatment and at three time points thereafter. cfDNA was extracted from 1.5 mL of plasma and before performing a methylation-specific PCR, bisulfate modification was carried out. The median levels of cfDNA, GSTP1, and APC copies in the baseline samples of CRPC patients (n = 47) were higher than in controls (n = 30). In the survival analysis, the group with baseline marker levels below median had significant less PCa-related deaths (P-values <0.02) and did not reach the median survival point. The survival distributions for the groups were statistically significant for the cfDNA concentration, GSTP1 and APC copies, as well as PSA combined with GSTP1 + APC (P-values <0.03). Furthermore, there were strong positive correlations between PSA and marker response after starting treatment (P-values <0.04). In conclusion, this study showed the kinetics of methylated cfDNA (GSTP1 and APC) in plasma of CRPC patients after starting treatment. Furthermore, the value of the markers before treatment is prognostic for overall survival. These results are promising for developing a test to guide treatment-decision-making for CRPC patients. © 2018 The Authors. The Prostate Published by Wiley Periodicals, Inc.

Altered T-Cell Balance in Lymphoid Organs of a Mouse Model of Colorectal Cancer

PubMed Central

Tanner, Scott M.; Daft, Joseph G.; Hill, Stephanie A.; Martin, Colin A.; Lorenz, Robin G.

2016-01-01

The adenomatous polyposis coli (APC) gene is a known tumor suppressor gene, and mice with mutations in Apc (ApcMin/+) spontaneously form multiple intestinal neoplasms. In this model of human colorectal cancer (CRC), it has been reported that CD4+ T-cell-derived interleukin 17 (IL-17) promotes intestinal tumor development, but it is not known if the Apc mutation actually directly alters T-cell function and subsequently tumor immunosurveillance. To investigate the ApcMin/+ mutation on T-cell function, flow cytometric, histochemical, and immunofluorescent studies on both wild-type (Apc+/+) and ApcMin/+ mice were performed. We identified decreased levels of interferon gamma (IFN-γ+)IL-17+ double-positive CD4+ cells in the mesenteric lymph nodes and Peyer’s patches of ApcMin/+ mice. In addition, altered levels of CD8+ cells, and changes in CD8+ production of IFN-γ and granzyme B were observed. These T-cell alterations did modify tumor immunosurveillance, as the adoptive transfer of splenocytes from ApcMin/+ animals into a chemically induced CRC model resulted in the inability to prevent epithelial dysplasia. These results suggest an altered T-cell balance in ApcMin/+ mice may disrupt intestinal homeostasis, consequently limiting intestinal tumor immunosurveillance. PMID:27798287

Altered T-Cell Balance in Lymphoid Organs of a Mouse Model of Colorectal Cancer.

PubMed

Tanner, Scott M; Daft, Joseph G; Hill, Stephanie A; Martin, Colin A; Lorenz, Robin G

2016-12-01

The adenomatous polyposis coli (APC) gene is a known tumor suppressor gene, and mice with mutations in Apc (Apc Min/+ ) spontaneously form multiple intestinal neoplasms. In this model of human colorectal cancer (CRC), it has been reported that CD4 + T-cell-derived interleukin 17 (IL-17) promotes intestinal tumor development, but it is not known if the Apc mutation actually directly alters T-cell function and subsequently tumor immunosurveillance. To investigate the Apc Min/+ mutation on T-cell function, flow cytometric, histochemical, and immunofluorescent studies on both wild-type (Apc +/+ ) and Apc Min/+ mice were performed. We identified decreased levels of interferon gamma (IFN-γ + )IL-17 + double-positive CD4 + cells in the mesenteric lymph nodes and Peyer's patches of Apc Min/+ mice. In addition, altered levels of CD8 + cells, and changes in CD8 + production of IFN-γ and granzyme B were observed. These T-cell alterations did modify tumor immunosurveillance, as the adoptive transfer of splenocytes from Apc Min/+ animals into a chemically induced CRC model resulted in the inability to prevent epithelial dysplasia. These results suggest an altered T-cell balance in Apc Min/+ mice may disrupt intestinal homeostasis, consequently limiting intestinal tumor immunosurveillance. © 2016 The Histochemical Society.

Controlling the response to DNA damage by the APC/C-Cdh1.

PubMed

de Boer, H Rudolf; Guerrero Llobet, S; van Vugt, Marcel A T M

2016-03-01

Proper cell cycle progression is safeguarded by the oscillating activities of cyclin/cyclin-dependent kinase complexes. An important player in the regulation of mitotic cyclins is the anaphase-promoting complex/cyclosome (APC/C), a multi-subunit E3 ubiquitin ligase. Prior to entry into mitosis, the APC/C remains inactive, which allows the accumulation of mitotic regulators. APC/C activation requires binding to either the Cdc20 or Cdh1 adaptor protein, which sequentially bind the APC/C and facilitate targeting of multiple mitotic regulators for proteasomal destruction, including Securin and Cyclin B, to ensure proper chromosome segregation and mitotic exit. Emerging data have indicated that the APC/C, particularly in association with Cdh1, also functions prior to mitotic entry. Specifically, the APC/C-Cdh1 is activated in response to DNA damage in G2 phase cells. These observations are in line with in vitro and in vivo genetic studies, in which cells lacking Cdh1 expression display various defects, including impaired DNA repair and aberrant cell cycle checkpoints. In this review, we summarize the current literature on APC/C regulation in response to DNA damage, the functions of APC/C-Cdh1 activation upon DNA damage, and speculate how APC/C-Cdh1 can control cell fate in the context of persistent DNA damage.

Selenium-containing allophycocyanin purified from selenium-enriched Spirulina platensis attenuates AAPH-induced oxidative stress in human erythrocytes through inhibition of ROS generation.

PubMed

Zhang, Haobin; Chen, Tianfeng; Jiang, Jie; Wong, Yum-Shing; Yang, Fang; Zheng, Wenjie

2011-08-24

Both selenium and allophycocyanin (APC) have been reported to show novel antioxidant activities. In this study, a fast protein liquid chromatographic method for purification of selenium-containing allophycocyanin (Se-APC) from selenium-enriched Spirulina platensis and the protective effect of Se-APC on 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH)-induced oxidative stress have been described. After fractionation by ammonium sulfate precipitation, and separation by DEAE-Sepharose ion-exchange and Sephacryl S-300 size exclusion chromatography, Se-APC with purity ratio (A652/A280) of 5.30 and Se concentration of 343.02 μg g(-1) protein was obtained. Se-APC exhibited stronger antioxidant activity than APC by scavenging ABTS (2,2'-azinobis-3-ethylbenzothiazolin-6-sulfonic acid) and AAPH free radicals. The oxidative hemolysis and morphological changes induced by AAPH in human erythrocytes were effectively reversed by coincubation with Se-APC. Lipid oxidation induced by the pro-oxidant agent cupric chloride in human plasma, as evaluated by formation of conjugated diene, was blocked by Se-APC. The accumulation of malondialdehyde, loss of reduced glutathione, and increase in enzyme activities of glutathione peroxidase and reductase induced by AAPH in human erythrocytes were effectively suppressed by Se-APC. Furthermore, Se-APC significantly prevented AAPH-induced intracellular reactive oxygen species (ROS) generation. Taken together, our results suggest that Se-APC demonstrates application potential in treatment of diseases in which excess production of ROS acts as a casual or contributory factor.

Evaluation of the cancer chemopreventive efficacy of rice bran in genetic mouse models of breast, prostate and intestinal carcinogenesis

PubMed Central

Verschoyle, R D; Greaves, P; Cai, H; Edwards, R E; Steward, W P; Gescher, A J

2007-01-01

Brown rice is a staple dietary constituent in Asia, whereas rice consumed in the Western world is generally white, obtained from brown rice by removal of the bran. We tested the hypothesis that rice bran interferes with development of tumours in TAg, TRansgenic Adenocarcinoma of the Mouse Prostate (TRAMP) or ApcMin mice, genetic models of mammary, prostate and intestinal carcinogenesis, respectively. Mice received rice bran (30%) in AIN-93G diet throughout their post-weaning lifespan. In TAg and TRAMP mice, rice bran did not affect carcinoma development. In TRAMP or wild-type C57Bl6/J mice, dietary rice bran increased kidney weight by 18 and 20%, respectively. Consumption of rice bran reduced numbers of intestinal adenomas in ApcMin mice by 51% (P<0.01), compared to mice on control diet. In parallel, dietary rice bran decreased intestinal haemorrhage in these mice, as reflected by increased haematocrit. At 10% in the diet, rice bran did not significantly retard ApcMin adenoma development. Likewise, low-fibre rice bran (30% in the diet) did not affect intestinal carcinogenesis, suggesting that the fibrous constituents of the bran mediate chemopreventive efficacy. The results suggest that rice bran might be beneficially evaluated as a putative chemopreventive intervention in humans with intestinal polyps. PMID:17211473

Osteopontin-deficient progenitor cells display enhanced differentiation to adipocytes.

PubMed

Moreno-Viedma, Veronica; Tardelli, Matteo; Zeyda, Maximilian; Sibilia, Maria; Burks, J Deborah; Stulnig, Thomas M

2018-03-06

Osteopontin (OPN, Spp1) is a protein upregulated in white adipose tissue (WAT) of obese subjects. Deletion of OPN protects mice from high-fat diet-induced WAT inflammation and insulin resistance. However, the alterations mediated by loss of OPN in WAT before the obesogenic challenge have not yet been investigated. Therefore, we hypothesised that the lack of OPN might enhance the pro-adipogenic micro environment before obesity driven inflammation. OPN deficiency was tested in visceral (V) and subcutaneous (SC) WAT from WT and Spp1 -/- female mice. Gene expression for hypoxia, inflammation and adipogenesis was checked in WT vs. Spp1 -/- mice (n=15). Adipocytes progenitor cells (APC) were isolated by fluorescence cell sorting and role of OPN deficiency in adipogenesis was investigated by cell images and RT-PCR. We show that Spp1 -/- maintained normal body and fat-pad weights, although hypoxia and inflammation markers were significantly reduced. In contrast, expression of genes involved in adipogenesis was increased in WAT from Spp1 -/- mice. Strikingly, APC from Spp1 -/- were diminished but differentiated more efficiently to adipocytes than those from control mice. APC from SC-WAT of lean OPN-deficient mice display an enhanced capacity for differentiating to adipocytes. These alterations may explain the healthy expansion of WAT in the OPN-deficient model which is associated with reduced inflammation and insulin resistance. Copyright © 2018. Published by Elsevier Ltd.

FBXW7 influences murine intestinal homeostasis and cancer, targeting Notch, Jun, and DEK for degradation.

PubMed

Babaei-Jadidi, Roya; Li, Ningning; Saadeddin, Anas; Spencer-Dene, Bradley; Jandke, Anett; Muhammad, Belal; Ibrahim, ElSayed E; Muraleedharan, Ranjithmenon; Abuzinadah, Mohammed; Davis, Hayley; Lewis, Annabelle; Watson, Susan; Behrens, Axel; Tomlinson, Ian; Nateri, Abdolrahman Shams

2011-02-14

The Fbxw7 (F-box/WD repeat-containing protein 7; also called CDC4, Sel10, Ago, and Fbw7) component of the SCF (Skp1/Cullin/F-box protein) E3 ubiquitin ligase complex acts as a tumor suppressor in several tissues and targets multiple transcriptional activators and protooncogenes for ubiquitin-mediated degradation. To understand Fbxw7 function in the murine intestine, in this study, we specifically deleted Fbxw7 in the murine gut using Villin-Cre (Fbxw7(ΔG)). In wild-type mice, loss of Fbxw7 in the gut altered homeostasis of the intestinal epithelium, resulted in elevated Notch and c-Jun expression, and induced development of adenomas at 9-10 mo of age. In the context of APC (adenomatous polyposis coli) deficiency (Apc(Min/+) mice), loss of Fbxw7 accelerated intestinal tumorigenesis and death and promoted accumulation of β-catenin in adenomas at late but not early time points. At early time points, Fbxw7 mutant tumors showed accumulation of the DEK protooncogene. DEK expression promoted cell division and altered splicing of tropomyosin (TPM) RNA, which may also influence cell proliferation. DEK accumulation and altered TPM RNA splicing were also detected in FBXW7 mutant human colorectal tumor tissues. Given their reduced lifespan and increased incidence of intestinal tumors, Apc(Min/+)Fbxw7(ΔG) mice may be used for testing carcinogenicity and drug screening.

Relationships of inflammatory and haemostatic markers with social class: results from a population-based study of older men.

PubMed

Ramsay, Sheena; Lowe, Gordon D O; Whincup, Peter H; Rumley, Ann; Morris, Richard W; Wannamethee, S Goya

2008-04-01

Haemostatic and inflammatory markers have been hypothesised to mediate the relationship of social class and cardiovascular disease (CVD). We investigated whether a range of inflammatory/haemostatic markers are associated with social class independent of chronic diseases and behavioural risk factors in a population-based sample of 2682 British men aged 60-79 without a physician diagnosis of CVD, diabetes or musculoskeletal disease requiring anti-inflammatory medications. Men in lower social classes had higher mean levels of C-reactive protein, fibrinogen, interleukin-6, white blood cell count, von Willebrand factor (vWF), factor VIII, activated protein C (APC) resistance, plasma viscosity, fibrin D-dimer and platelet count, compared to higher social class groups; but not of tissue plasminogen activator antigen, haematocrit or activated partial prothrombin time. After adjustment for behavioural risk factors (smoking, alcohol, physical activity and body mass), the associations of social class with vWF, factor VIII, APC resistance, plasma viscosity, and platelet count though weakened, remained statistically significant, while those of other markers were considerably attenuated. In this study of older men without CVD, the social gradient in inflammatory and haemostatic markers was substantially explained by behavioural risk factors. The effect of socio-economic gradient on the factor VIII-vWF complex, APC resistance, plasma viscosity and platelet count merits further study.

A metabolic switch controls intestinal differentiation downstream of Adenomatous polyposis coli (APC).

PubMed

Sandoval, Imelda T; Delacruz, Richard Glenn C; Miller, Braden N; Hill, Shauna; Olson, Kristofor A; Gabriel, Ana E; Boyd, Kevin; Satterfield, Christeena; Remmen, Holly Van; Rutter, Jared; Jones, David A

2017-04-11

Elucidating signaling pathways that regulate cellular metabolism is essential for a better understanding of normal development and tumorigenesis. Recent studies have shown that mitochondrial pyruvate carrier 1 (MPC1) , a crucial player in pyruvate metabolism, is downregulated in colon adenocarcinomas. Utilizing zebrafish to examine the genetic relationship between MPC1 and Adenomatous polyposis coli (APC), a key tumor suppressor in colorectal cancer, we found that apc controls the levels of mpc1 and that knock down of mpc1 recapitulates phenotypes of impaired apc function including failed intestinal differentiation. Exogenous human MPC1 RNA rescued failed intestinal differentiation in zebrafish models of apc deficiency. Our data demonstrate a novel role for apc in pyruvate metabolism and that pyruvate metabolism dictates intestinal cell fate and differentiation decisions downstream of apc .

Comprehensive Analysis of the Activation and Proliferation Kinetics and Effector Functions of Human Lymphocytes, and Antigen Presentation Capacity of Antigen-Presenting Cells in Xenogeneic Graft-Versus-Host Disease.

PubMed

Kawasaki, Yasufumi; Sato, Kazuya; Hayakawa, Hiroko; Takayama, Norihito; Nakano, Hirofumi; Ito, Ryoji; Mashima, Kiyomi; Oh, Iekuni; Minakata, Daisuke; Yamasaki, Ryoko; Morita, Kaoru; Ashizawa, Masahiro; Yamamoto, Chihiro; Hatano, Kaoru; Fujiwara, Shin-Ichiro; Ohmine, Ken; Muroi, Kazuo; Kanda, Yoshinobu

2018-04-17

Xenogeneic graft-versus-host disease (GVHD) models in highly immunodeficient mice are currently being used worldwide to investigate human immune responses against foreign antigens in vivo. However, the individual roles of CD4 + and CD8 + T cells, and donor/host hematopoietic and nonhematopoietic antigen-presenting cells (APCs) in the induction and development of GVHD have not been fully investigated. In the present study, we comprehensively investigated the immune responses of human T cells and the antigen presentation capacity of donor/host hematopoietic and nonhematopoietic APCs in xenogeneic GVHD models using nonobese diabetic/Shi-scid-IL2rg null mice. CD4 + T cells and, to a lesser extent, CD8 + T cells individually mediated potentially lethal GVHD. In addition to inflammatory cytokine production, CD4 + T cells also supported the activation and proliferation of CD8 + T cells. Using bone marrow chimeras, we demonstrated that host hematopoietic, but not nonhematopoietic, APCs play a critical role in the development of CD4 + T cell-mediated GVHD. During early GVHD, we detected 2 distinct populations in memory CD4 + T cells. One population was highly activated and proliferated in major histocompatibility complex antigen (MHC) +/+ mice but not in MHC -/- mice, indicating alloreactive T cells. The other population showed a less activated and slowly proliferative status regardless of host MHC expression, and was associated with higher susceptibility to apoptosis, indicating nonalloreactive T cells in homeostasis-driven proliferation. These observations are clinically relevant to donor T cell response after allogeneic hematopoietic stem cell transplantation. Our findings provide a better understanding of the immunobiology of humanized mice and support the development of novel options for the prevention and treatment for GVHD. Copyright © 2018. Published by Elsevier Inc.

Clinical and electrocardiographic characteristics for prediction of new-onset atrial fibrillation in asymptomatic patients with atrial premature complexes.

PubMed

Im, Sung Il; Park, Dong Hyun; Kim, Bong Joon; Cho, Kyoung Im; Kim, Hyun Su; Heo, Jung Ho

2018-06-01

Identification of precursors of atrial fibrillation (AF) may lead to early detection and prevent associated morbidity and mortality. Atrial premature complexes (APCs) are commonly seen in healthy subjects. However, there was limited data about the clinical and electrocardiographic (ECG) characteristics for prediction of new-onset AF in asymptomatic patients with APCs in the long-term follow up. The Kosin University (No. 2014-02-04) 24-h holter monitoring, echocardiography, ECG database were reviewed from 2008 to 2016 to identify new- onset AF in patients with APCs. We analyzed demographic and clinical features and the nature of the APCs by ECG according to new-onset AF in those patients. Among 652 patients who underwent 24-h holter monitoring, 226 (34.4%) patients had new-onset AF. There was no difference of the baseline characteristics between new-onset AF group and non-AF group. In univariate analysis, hypertension (HTN), renal failure (CRF), high APC burdens, fastest APC running heart rate (HR), minimal HR, left ventricular ejection fraction (LVEF), left atrial volume index, peak mitral flow velocity of the early rapid filling wave and tricuspid regurgitation grade were significantly associated with new-onset AF. In multivariate analysis, higher APCs burden ( P  = 0.047), higher fastest APCs running HR ( P  = 0.034) and lower minimal HR ( P  = 0.025) were independent risk factors for new-onset AF in asymptomatic patients with APCs. Higher APCs burden, higher fastest APCs running HR and lower minimal HR were associated with new-onset AF in asymptomatic patients with APCs in the long-term follow up.

A kinetic model to study the regulation of β-catenin, APC, and Axin in the human colonic crypt.

PubMed

Emerick, Brooks; Schleiniger, Gilberto; Boman, Bruce M

2017-11-01

The Wnt/[Formula: see text]-catenin pathway plays a crucial role in stem cell renewal and differentiation in the normal human colonic crypt. The balance between [Formula: see text]-catenin and APC along the crypt axis determines its normal functionality. The mechanism that deregulates this balance may give insight into the initiation of colorectal cancer. This is significant because the spatial dysregulation of [Formula: see text]-catenin by the mutated tumor suppressor gene/protein APC in human colonic crypts is responsible for the initiation and growth of colorectal cancer. We consider a regulatory function that promotes APC synthesis within the cell and its effect on the accumulation of the Wnt target protein, [Formula: see text]-catenin. It is evident that an APC gradient exists along the crypt axis; however, the mechanism by which APC expression is regulated within the cell is not well known. We investigate the dynamics of an APC regulatory mechanism with an increased level of Axin at the subcellular level. Model output shows an increase of APC for a diminished Wnt signal, which explains the APC gradient along the crypt. We find that the dynamic interplay between [Formula: see text]-catenin, APC, and Axin produces oscillatory behavior, which is controlled by the Wnt stimulus. In the presence of reduced functional APC, the oscillations are amplified, which suggests that the cell remains in a more proliferative state for longer periods of time. Increased Axin levels (typical of mammalian cells) reduce oscillatory behavior and minimize the levels of [Formula: see text]-catenin within the cell while raising the levels of APC.

PTT analysis of polyps from FAP patients reveals a great majority of APC truncating mutations

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

Luijt, R.B. van der; Khan, P.M.; Tops, C.M.J.

The adenomatous polyposis coli (APC) gene plays an important role in colorectal carcinogenesis. Germline APC mutations are associated with familial adenomatous polyposis (FAP), an autosomal dominantly inherited predisposition to colorectal cancer, characterized by the development of numerous adenomatous polyps in the large intestine. In order to investigate whether somatic inactivation of the remaining APC allele is necessary for adenoma formation, we collected multiple adenomatous polyps from individual FAP patients and investigated the presence of somatic mutations in the APC gene. The analysis of somatic APC mutations in these tumor samples was performed using a rapid and sensitive assay, called themore » protein truncation test (PTT). Chain-terminating somatic APC mutations were detected in the great majority of the tumor samples investigated. As expected, these mutations were mainly located in the mutation cluster region (MCR) in exon 15. Our results confirm that somatic mutation of the second APC allele is required for adenoma formation in FAP. Interestingly, in the polyps investigated in our study, the second APC allele is somatically inactivated through point mutation leading to a stop codon rather than by loss of heterozygosity. The observation that somatic second hits in APC are required for tumor development in FAP is in apparent accordance with the Knudson hypothesis for classical tumor suppressor genes. However, it is yet unknown whether chain-terminating APC mutations lead to a truncated protein exerting a dominant-negative effect or whether these mutations result in a null allele. Further investigation of this important issue will hopefully provide a better understanding of the mechanism of action of the mutated APC alleles in colorectal carcinogenesis.« less

A novel Fizzy/Cdc20-dependent mechanism suppresses necrosis in neural stem cells

PubMed Central

Kuang, Chaoyuan; Golden, Krista L.; Simon, Claudio R.; Damrath, John; Buttitta, Laura; Gamble, Caitlin E.; Lee, Cheng-Yu

2014-01-01

Cancer stem cells likely survive chemotherapy or radiotherapy by acquiring mutations that inactivate the endogenous apoptotic machinery or by cycling slowly. Thus, knowledge about the mechanisms linking the activation of an alternative cell death modality and the cell cycle machinery could have a transformative impact on the development of new cancer therapies, but the mechanisms remain completely unknown. We investigated the regulation of alternative cell death in Drosophila larval brain neural stem cells (neuroblasts) in which apoptosis is normally repressed. From a screen, we identified two novel loss-of-function alleles of the Cdc20/fizzy (fzy) gene that lead to premature brain neuroblast loss without perturbing cell proliferation in other diploid cell types. Fzy is an evolutionarily conserved regulator of anaphase promoting complex/cyclosome (APC/C). Neuroblasts carrying the novel fzy allele or exhibiting reduced APC/C function display hallmarks of necrosis. By contrast, neuroblasts overexpressing the non-degradable form of canonical APC/C substrates required for cell cycle progression undergo mitotic catastrophe. These data strongly suggest that Fzy can elicit a novel pro-survival function of APC/C by suppressing necrosis. Neuroblasts experiencing catastrophic cellular stress, or overexpressing p53, lose Fzy expression and undergo necrosis. Co-expression of fzy suppresses the death of these neuroblasts. Consequently, attenuation of the Fzy-dependent survival mechanism functions downstream of catastrophic cellular stress and p53 to eliminate neuroblasts by necrosis. Strategies that target the Fzy-dependent survival mechanism might lead to the discovery of new treatments or complement the pre-existing therapies to eliminate apoptosis-resistant cancer stem cells by necrosis. PMID:24598157

T cell reactivity with allergoids: influence of the type of APC.

PubMed

Kahlert, H; Grage-Griebenow, E; Stüwe, H T; Cromwell, O; Fiebig, H

2000-08-15

The use of allergoids for allergen-specific immunotherapy has been established for many years. The characteristic features of these chemically modified allergens are their strongly reduced IgE binding activity compared with the native form and the retained immunogenicity. T cell reactivity of chemically modified allergens is documented in animals, but in humans indirect evidence of reactivity has been concluded from the induction of allergen-specific IgG during immunotherapy. Direct evidence of T cell reactivity was obtained recently using isolated human T cells. To obtain further insight into the mechanism of action of allergoids, we compared the Ag-presenting capacity of different APC types, including DC and macrophages, generated from CD14+ precursor cells from the blood of grass pollen allergic subjects, autologous PBMC, and B cells. These APC were used in experiments together with Phl p 5-specific T cell clones under stimulation with grass pollen allergen extract, rPhl p 5b, and the respective allergoids. Using DC and macrophages, allergoids exhibited a pronounced and reproducible T cell-stimulating capacity. Responses were superior to those with PBMC, and isolated B cells failed to present allergoids. Considerable IL-12 production was observed only when using the DC for Ag presentation of both allergens and allergoids. The amount of IL-10 in supernatants was dependent on the phenotype of the respective T cell clone. High IL-10 production was associated with suppressed IL-12 production from the DC in most cases. In conclusion, the reactivity of Th cells with allergoids is dependent on the type of the APC.

Trends in gastrointestinal cancer incidence in Iran, 2001-2010: a joinpoint analysis

PubMed Central

Motlagh, Ali; Karimi Jaberi, Maryam

2016-01-01

OBJECTIVES The main purpose of this study was to evaluate changes in the time trends of stomach, colorectal, and esophageal cancer during the past decade in Iran. METHODS Cancer incidence data for the years 2001 to 2010 were obtained from the cancer registration of the Ministry of Health. All incidence rates were directly age-standardized to the world standard population. In order to identified significant changes in time trends, we performed a joinpoint analysis. The annual percent change (APC) for each segment of the trends was then calculated. RESULTS The incidence of stomach cancer increased from 4.18 and 2.41 per 100,000 population in men and women, respectively, in 2001 to 17.06 (APC, 16.7%) and 8.85 (APC, 16.2%) per 100,000 population in 2010 for men and women, respectively. The corresponding values for colorectal cancer were 2.12 and 2.00 per 100,000 population for men and women, respectively, in 2001 and 11.28 (APC, 20.0%) and 10.33 (APC, 20.0%) per 100,000 in 2010. For esophageal cancer, the corresponding increase was from 3.25 and 2.10 per 100,000 population in 2001 to 5.57 (APC, 12.0%) and 5.62 (APC, 11.2%) per 100,000 population among men and women, respectively. The incidence increased most rapidly for stomach cancer in men and women aged 80 years and older (APC, 23.7% for men; APC, 18.6% for women), for colorectal cancer in men aged 60 to 69 years (APC, 24.2%) and in women aged 50 to 59 years (APC, 25.1%), and for esophageal cancer in men and women aged 80 years and older (APC, 17.5% for men; APC,15.3% for women) over the period of the study. CONCLUSIONS The incidence of gastrointestinal cancer significantly increased during the past decade. Therefore, monitoring the trends of cancer incidence can assist efforts for cancer prevention and control. PMID:27923268

Differential RNA-seq analysis comparing APC-defective and APC-restored SW480 colorectal cancer cells.

PubMed

King, Lauren E; Love, Christopher G; Sieber, Oliver M; Faux, Maree C; Burgess, Antony W

2016-03-01

The adenomatous polyposis coli (APC) tumour suppressor gene is mutated in about 80% of colorectal cancers (CRC) Brannon et al. (2014) [1]. APC is a large multifunctional protein that regulates many biological functions including Wnt signalling (through the regulation of beta-catenin stability) Reya and Clevers (2005) [2], cell migration Kroboth et al. (2007), Sansom et al. (2004) [3], [4], mitosis Kaplan et al. (2001) [5], cell adhesion Faux et al. (2004), Carothers et al. (2001) [6], [7] and differentiation Sansom et al. (2004) [4]. Although the role of APC in CRC is often described as the deregulation of Wnt signalling, its other biological functions suggest that there are other factors at play that contribute to the onset of adenomas and the progression of CRC upon the truncation of APC. To identify genes and pathways that are dysregulated as a consequence of loss of function of APC, we compared the gene expression profiles of the APC mutated human CRC cell line SW480 following reintroduction of wild-type APC (SW480 + APC) or empty control vector (SW480 + vector control) Faux et al. (2004) . Here we describe the RNA-seq data derived for three biological replicates of parental SW480, SW480 + vector control and SW480 + APC cells, and present the bioinformatics pipeline used to test for differential gene expression and pathway enrichment analysis. A total of 1735 genes showed significant differential expression when APC was restored and were enriched for genes associated with cell polarity, Wnt signalling and the epithelial to mesenchymal transition. There was additional enrichment for genes involved in cell-cell adhesion, cell-matrix junctions, angiogenesis, axon morphogenesis and cell movement. The raw and analysed RNA-seq data have been deposited in the Gene Expression Omnibus (GEO) database under accession number GSE76307. This dataset is useful for further investigations of the impact of APC mutation on the properties of colorectal cancer cells.

A randomized clinical trial of the effects of supplemental calcium and vitamin D3 on the APC/β-catenin pathway in the normal mucosa of colorectal adenoma patients.

PubMed

Ahearn, Thomas U; Shaukat, Aasma; Flanders, W Dana; Rutherford, Robin E; Bostick, Roberd M

2012-10-01

APC/β-catenin pathway perturbation is a common early event in colorectal carcinogenesis and is affected by calcium and vitamin D in basic science studies. To assess the effects of calcium and vitamin D on adenomatous polyposis coli (APC), β-catenin, and E-cadherin expression in the normal appearing colorectal mucosa of sporadic colorectal adenoma patients, we conducted a randomized, double-blinded, placebo-controlled 2 × 2 factorial clinical trial. Pathology-confirmed colorectal adenoma cases were treated with 2 g/day elemental calcium and/or 800 IU/day vitamin D(3) versus placebo over 6 months (N = 92; 23/group). Overall APC, β-catenin, and E-cadherin expression and distributions in colon crypts in normal-appearing rectal mucosa biopsies were detected by standardized automated immunohistochemistry and quantified by image analysis. In the vitamin D(3)-supplemented group relative to placebo, the proportion of APC in the upper 40% of crypts (Φh APC) increased 21% (P = 0.01), β-catenin decreased 12% (P = 0.18), E-cadherin increased 72% (P = 0.03), and the Φh APC/β-catenin ratio (APC/β-catenin score) increased 31% (P = 0.02). In the calcium-supplemented group Φh APC increased 10% (P = 0.12), β-catenin decreased 15% (P = 0.08), and the APC/β-catenin score increased 41% (P = 0.01). In the calcium/vitamin D(3)-supplemented group, β-catenin decreased 11% (P = 0.20), E-cadherin increased 51% (P = 0.08), and the APC/β-catenin score increased 16% (P = 0.26). These results support (i) that calcium and vitamin D modify APC, β-catenin, and E-cadherin expression in humans in directions hypothesized to reduce risk for colorectal neoplasms, (ii) calcium and vitamin D as potential chemopreventive agents against colorectal neoplasms, and (iii) the potential of APC, β-catenin, and E-cadherin expression as modifiable, preneoplastic risk biomarkers for colorectal neoplasms.

A multigene mutation classification of 468 colorectal cancers reveals a prognostic role for APC

PubMed Central

Schell, Michael J.; Yang, Mingli; Teer, Jamie K.; Lo, Fang Yin; Madan, Anup; Coppola, Domenico; Monteiro, Alvaro N. A.; Nebozhyn, Michael V.; Yue, Binglin; Loboda, Andrey; Bien-Willner, Gabriel A.; Greenawalt, Danielle M.; Yeatman, Timothy J.

2016-01-01

Colorectal cancer (CRC) is a highly heterogeneous disease, for which prognosis has been relegated to clinicopathologic staging for decades. There is a need to stratify subpopulations of CRC on a molecular basis to better predict outcome and assign therapies. Here we report targeted exome-sequencing of 1,321 cancer-related genes on 468 tumour specimens, which identified a subset of 17 genes that best classify CRC, with APC playing a central role in predicting overall survival. APC may assume 0, 1 or 2 truncating mutations, each with a striking differential impact on survival. Tumours lacking any APC mutation carry a worse prognosis than single APC mutation tumours; however, two APC mutation tumours with mutant KRAS and TP53 confer the poorest survival among all the subgroups examined. Our study demonstrates a prognostic role for APC and suggests that sequencing of APC may have clinical utility in the routine staging and potential therapeutic assignment for CRC. PMID:27302369

PLK1 has tumor-suppressive potential in APC-truncated colon cancer cells.

PubMed

Raab, Monika; Sanhaji, Mourad; Matthess, Yves; Hörlin, Albrecht; Lorenz, Ioana; Dötsch, Christina; Habbe, Nils; Waidmann, Oliver; Kurunci-Csacsko, Elisabeth; Firestein, Ron; Becker, Sven; Strebhardt, Klaus

2018-03-16

The spindle assembly checkpoint (SAC) acts as a molecular safeguard in ensuring faithful chromosome transmission during mitosis, which is regulated by a complex interplay between phosphatases and kinases including PLK1. Adenomatous polyposis coli (APC) germline mutations cause aneuploidy and are responsible for familial adenomatous polyposis (FAP). Here we study the role of PLK1 in colon cancer cells with chromosomal instability promoted by APC truncation (APC-ΔC). The expression of APC-ΔC in colon cells reduces the accumulation of mitotic cells upon PLK1 inhibition, accelerates mitotic exit and increases the survival of cells with enhanced chromosomal abnormalities. The inhibition of PLK1 in mitotic, APC-∆C-expressing cells reduces the kinetochore levels of Aurora B and hampers the recruitment of SAC component suggesting a compromised mitotic checkpoint. Furthermore, Plk1 inhibition (RNAi, pharmacological compounds) promotes the development of adenomatous polyps in two independent Apc Min/+ mouse models. High PLK1 expression increases the survival of colon cancer patients expressing a truncated APC significantly.

The Importance of TLR2 and Macrophages in Modulating a Humoral Response after Encountering Streptococcus pneumoniae

DTIC Science & Technology

2008-03-26

Response after Encountering Streptococcus Pneumoniae" Brian Schae:5 ,Ph.D. Department of Microbi ogy & Immunology Committee Chairperson Masters...presenting cells (APCs), such as macrophages (M ) and dendritic cells (DC) recognize microbial surface components via cell surface receptors (i.e...stimulating factor (GM-CSF). TH1 cells are able to secrete IFN- , which is important in activating M to produce mediators important for microbial

Pharmacological Differentiation of Thrombomodulin Alfa and Activated Protein C on Coagulation and Fibrinolysis In Vitro.

PubMed

Tanaka, Kosuke; Tawara, Shunsuke; Tsuruta, Kazuhisa; Hoppensteadt, Debra; Fareed, Jawed

2018-01-01

Although thrombomodulin alfa (TM alfa), recombinant human soluble thrombomodulin, exerts antithrombogenic effects through activated protein C (APC), clinical trials suggested that TM alfa has a lower bleeding risk than does recombinant human APC. To address the mechanism explaining this difference, effects of TM alfa and APC on thrombogenic, coagulation, and fibrinolytic processes were compared in vitro. TM alfa and APC inhibited generation of thrombogenic markers, thrombin, and prothrombin fragment F1+2 and prolonged coagulation parameters, activated clotting time (ACT), and activated partial thromboplastin time (APTT). Concentrations of TM alfa effective for thrombin and F1+2 generation inhibition were comparable to those of APC. However, effects of TM alfa on ACT and APTT were clearly weaker than those of APC. TM alfa significantly prolonged clot lysis time (CLT) and decreased LY30, a parameter of degree of fibrinolysis in thromboelastography, whereas APC significantly shortened CLT and increased LY30. These results suggested that while the antithrombogenic effects of TM alfa were similar to those of APC, its anticoagulant effects were lower. In addition, effects of TM alfa were antifibrinolytic, while those of APC were profibrinolytic.

Endosome-mediated autophagy

PubMed Central

Kondylis, Vangelis; van Nispen tot Pannerden, Hezder E.; van Dijk, Suzanne; ten Broeke, Toine; Wubbolts, Richard; Geerts, Willie J.; Seinen, Cor; Mutis, Tuna; Heijnen, Harry F.G.

2013-01-01

Activation of TLR signaling has been shown to induce autophagy in antigen-presenting cells (APCs). Using high-resolution microscopy approaches, we show that in LPS-stimulated dendritic cells (DCs), autophagosomes emerge from MHC class II compartments (MIICs) and harbor both the molecular machinery for antigen processing and the autophagosome markers LC3 and ATG16L1. This ENdosome-Mediated Autophagy (ENMA) appears to be the major type of autophagy in DCs, as similar structures were observed upon established autophagy-inducing conditions (nutrient deprivation, rapamycin) and under basal conditions in the presence of bafilomycin A1. Autophagosome formation was not significantly affected in DCs expressing ATG4BC74A mutant and atg4b−/− bone marrow DCs, but the degradation of the autophagy substrate SQSTM1/p62 was largely impaired. Furthermore, we demonstrate that the previously described DC aggresome-like LPS-induced structures (DALIS) contain vesicular membranes, and in addition to SQSTM1 and ubiquitin, they are positive for LC3. LC3 localization on DALIS is independent of its lipidation. MIIC-driven autophagosomes preferentially engulf the LPS-induced SQSTM1-positive DALIS, which become later degraded in autolysosomes. DALIS-associated membranes also contain ATG16L1, ATG9 and the Q-SNARE VTI1B, suggesting that they may represent (at least in part) a membrane reservoir for autophagosome expansion. We propose that ENMA constitutes an unconventional, APC-specific type of autophagy, which mediates the processing and presentation of cytosolic antigens by MHC class II machinery, and/or the selective clearance of toxic by-products of elevated ROS/RNS production in activated DCs, thereby promoting their survival. PMID:23481895

The impact of eicosanoids on the crosstalk between innate and adaptive immunity: the key roles of dendritic cells.

PubMed

Harizi, H; Gualde, N

2005-06-01

The innate immune response is essentially the first line of defense against an invading pathogen. Through specialized receptors, known as pattern recognition receptors, especially Toll-like receptors, specialized cells of myeloid origin, including macrophages and dendritic cells (DCs) are able to phagocytose microorganisms and induce an innate inflammatory response. Although B and T lymphocytes recognize tissue antigens with high specificity, they are unable to initiate immune responses. The decision to activate an appropriate immune response is made by unique DC, the most professional antigen-presenting cells (APCs) which control the responses of several types of lymphocytes and play central role in the transition between innate and adaptive immunity. Increased secretion of inflammatory endogenous mediators such as cytokines and arachidonic acid-derived lipid mediators, also termed eicosanoids, can activate APC, particularly DC, which in turn induce an adaptive immune response. There is an increasing evidence that eicosanoids play an important role in connecting innate and adaptive immunity by acting on cells of both systems. Prostanoids, a major class of eicosanoids, have a great impact on inflammatory and immune responses. PGE(2) is one of the best known and most well-characterized prostanoids in terms of immunomodulation. Although cytokines are known as key regulators of immunity, eicosanoids, including PGE(2), PGD(2), LTB(4), and LTC(4), may also affect cells of immune system by modulating cytokine release, cell differentiation, survival, migration, antigen presentation, and apoptosis. By acting on various aspects of immune and inflammatory reactions, these lipid mediators emerge as key regulators of the crosstalk between innate and adaptive immunity.

42 CFR 416.167 - Basis of payment.

Code of Federal Regulations, 2010 CFR

2010-10-01

... classification (APC) groups and payment weights. (1) ASC covered surgical procedures are classified using the APC... section, an ASC relative payment weight is determined based on the APC relative payment weight for each covered surgical procedure and covered ancillary service that has an applicable APC relative payment...

Activated protein C: biased for translation.

PubMed

Griffin, John H; Zlokovic, Berislav V; Mosnier, Laurent O

2015-05-07

The homeostatic blood protease, activated protein C (APC), can function as (1) an antithrombotic on the basis of inactivation of clotting factors Va and VIIIa; (2) a cytoprotective on the basis of endothelial barrier stabilization and anti-inflammatory and antiapoptotic actions; and (3) a regenerative on the basis of stimulation of neurogenesis, angiogenesis, and wound healing. Pharmacologic therapies using recombinant human and murine APCs indicate that APC provides effective acute or chronic therapies for a strikingly diverse range of preclinical injury models. APC reduces the damage caused by the following: ischemia/reperfusion in brain, heart, and kidney; pulmonary, kidney, and gastrointestinal inflammation; sepsis; Ebola virus; diabetes; and total lethal body radiation. For these beneficial effects, APC alters cell signaling networks and gene expression profiles by activating protease-activated receptors 1 and 3. APC's activation of these G protein-coupled receptors differs completely from thrombin's activation mechanism due to biased signaling via either G proteins or β-arrestin-2. To reduce APC-associated bleeding risk, APC variants were engineered to lack >90% anticoagulant activity but retain normal cell signaling. Such a neuroprotective variant, 3K3A-APC (Lys191-193Ala), has advanced to clinical trials for ischemic stroke. A rich data set of preclinical knowledge provides a solid foundation for potential translation of APC variants to future novel therapies. © 2015 by The American Society of Hematology.

Analysis of APC mutation in human ameloblastoma and clinical significance.

PubMed

Li, Ning; Liu, Bing; Sui, Chengguang; Jiang, Youhong

2016-01-01

As a highly conserved signaling pathway, Wnt/β-catenin signal transduction pathway plays an important role in many processes. Either in the occurrence or development of tumor, activation of this pathway takes an important place. APC inhibits Wnt/β-catenin pathway to regulate cell proliferation and differentiation. This study aimed to investigate the function of cancer suppressor gene. PCR amplification and sequencing method was used to analyze APC mutations of human clinical specimens. The pathological specimens were collected for PCR and clear electrophoretic bands were obtained after electrophoresis. The gene sequence obtained after purification and sequencing analysis was compared with the known APC gene sequence (NM_000038.5). Base mutations at APC 1543 (T → C), APC-4564 (G → A), APC-5353 (T → G), APC-5550 (T → A) and APC-5969 (G → A) locus existed in 22 (27.5 %), 12 (15 %), 5 (6.25 %), 13 (16.25 %) and 12 patients (15 %), respectively. Gene mutations existed in ameloblastoma, and the mutation loci were 1543 locus (T → C), 4564 locus (G → A), 5353 locus (T → G), 5550 locus (T → A) and 5969 locus (G → A) 15 %, respectively. APC mutation plays a certain role in monitoring the tumor malignant degree as it may indicate the transition process of ameloblastoma malignant phenotype.

Reduced expression of APC-1B but not APC-1A by the deletion of promoter 1B is responsible for familial adenomatous polyposis.

PubMed

Yamaguchi, Kiyoshi; Nagayama, Satoshi; Shimizu, Eigo; Komura, Mitsuhiro; Yamaguchi, Rui; Shibuya, Tetsuo; Arai, Masami; Hatakeyama, Seira; Ikenoue, Tsuneo; Ueno, Masashi; Miyano, Satoru; Imoto, Seiya; Furukawa, Yoichi

2016-05-24

Germline mutations in the tumor suppressor gene APC are associated with familial adenomatous polyposis (FAP). Here we applied whole-genome sequencing (WGS) to the DNA of a sporadic FAP patient in which we did not find any pathological APC mutations by direct sequencing. WGS identified a promoter deletion of approximately 10 kb encompassing promoter 1B and exon1B of APC. Additional allele-specific expression analysis by deep cDNA sequencing revealed that the deletion reduced the expression of the mutated APC allele to as low as 11.2% in the total APC transcripts, suggesting that the residual mutant transcripts were driven by other promoter(s). Furthermore, cap analysis of gene expression (CAGE) demonstrated that the deleted promoter 1B region is responsible for the great majority of APC transcription in many tissues except the brain. The deletion decreased the transcripts of APC-1B to 39-45% in the patient compared to the healthy controls, but it did not decrease those of APC-1A. Different deletions including promoter 1B have been reported in FAP patients. Taken together, our results strengthen the evidence that analysis of structural variations in promoter 1B should be considered for the FAP patients whose pathological mutations are not identified by conventional direct sequencing.

Clinical and genetic characterization of classical forms of familial adenomatous polyposis: a Spanish population study.

PubMed

Rivera, B; González, S; Sánchez-Tomé, E; Blanco, I; Mercadillo, F; Letón, R; Benítez, J; Robledo, M; Capellá, G; Urioste, M

2011-04-01

Classical familial adenomatous polyposis (FAP) is characterized by the appearance of >100 colorectal adenomas. We screened the APC and MUTYH genes for mutations and evaluated the genotype-phenotype correlation in 136 Spanish classical FAP families. APC/MUTYH mutations were detected in 107 families. Sixty-four distinct APC point mutations were detected in 95 families of which all were truncating mutations. A significant proportion (39.6%) had not been previously reported. Mutations were spread over the entire coding region and great rearrangements were identified in six families. Another six families exhibited biallelic MUTYH mutations. No APC or MUTYH mutations were detected in 29 families. These APC/MUTYH-negative families showed clinical differences with the APC-positive families. A poor correlation between phenotype and mutation site was observed. Our results highlight that a broad approach in the genetic study must be considered for classical FAP due to involvement of both APC and MUTYH and the heterogeneous spectrum of APC mutations observed in this Spanish population. The scarcely consistent genotype-phenotype correlation does not allow making specific recommendations regarding screening and management. Differences observed in APC/MUTYH-negative families may reflect a genetic basis other than mutations in APC and MUTYH genes for FAP predisposition. © The Author 2010. Published by Oxford University Press on behalf of the European Society for Medical Oncology.

APC10.1 cells as a model for assessing the efficacy of potential chemopreventive agents in the Apc(Min) mouse model in vivo.

PubMed

Sale, Stewart; Fong, Isabel L; de Giovanni, Carla; Landuzzi, Lorena; Brown, Karen; Steward, William P; Gescher, Andreas J

2009-11-01

Apc(Min) mice are widely used for mechanism and efficacy studies associated with the development of chemopreventive agents. APC10.1 cells have been derived from Apc(Min) mouse adenomas and retain the heterozygous Apc genotype. We tested the hypothesis that this cell type may provide an in vitro model to predict chemopreventive activity of agents in the Apc(Min) mouse in vivo. The growth inhibitory properties of 14 putative colorectal cancer chemopreventive agents, tricin, apigenin, 3',4',5',5,7-pentamethoxyflavone, resveratrol, curcumin, 3,4-methylenedioxy-3',4',5'-trimethoxychalcone (DMU135), 3,4,5,4'-tetramethoxystilbene (DMU212), celecoxib, aspirin, piroxicam, all-trans-retinoic acid, difluoromethylornithine (DFMO), quercetin and cyanidin-3-glucoside, were studied in this cell line, and the IC(50) values were calculated. The IC(50) values were plotted against previously published data of reduction of adenoma numbers caused by these agents in Apc(Min) mice. The correlation co-efficient was 0.678 (p<0.01), suggesting that there was a tentative correlation between the ability to inhibit the growth of APC10.1 cells and the ability to delay adenoma development in vivo. If this relationship is supported by using further agents, APC10.1 cells may serve in the future as an initial screen to prioritise compounds for assessing chemopreventive efficacy in Apc(Min) mice in vivo. Such a screen could reduce the number of animals required to find active agents, help reduce costs and increase throughput.

Ag-Pd-Cu alloy inserted transparent indium tin oxide electrodes for organic solar cells

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

Kim, Hyo-Joong; Seo, Ki-Won; Kim, Han-Ki, E-mail: imdlhkkim@khu.ac.kr

2014-09-01

The authors report on the characteristics of Ag-Pd-Cu (APC) alloy-inserted indium tin oxide (ITO) films sputtered on a glass substrate at room temperature for application as transparent anodes in organic solar cells (OSCs). The effect of the APC interlayer thickness on the electrical, optical, structural, and morphological properties of the ITO/APC/ITO multilayer were investigated and compared to those of ITO/Ag/ITO multilayer electrodes. At the optimized APC thickness of 8 nm, the ITO/APC/ITO multilayer exhibited a resistivity of 8.55 × 10{sup −5} Ω cm, an optical transmittance of 82.63%, and a figure-of-merit value of 13.54 × 10{sup −3} Ω{sup −1}, comparable to those of the ITO/Ag/ITOmore » multilayer. Unlike the ITO/Ag/ITO multilayer, agglomeration of the metal interlayer was effectively relieved with APC interlayer due to existence of Pd and Cu elements in the thin region of the APC interlayer. The OSCs fabricated on the ITO/APC/ITO multilayer showed higher power conversion efficiency than that of OSCs prepared on the ITO/Ag/ITO multilayer below 10 nm due to the flatness of the APC layer. The improved performance of the OSCs with ITO/APC/ITO multilayer electrodes indicates that the APC alloy interlayer prevents the agglomeration of the Ag-based metal interlayer and can decrease the thickness of the metal interlayer in the oxide-metal-oxide multilayer of high-performance OSCs.« less

Functional characterization of Anaphase Promoting Complex/Cyclosome (APC/C) E3 ubiquitin ligases in tumorigenesis

PubMed Central

Zhang, Jinfang; Wan, Lixin; Dai, Xiangpeng; Sun, Yi; Wei, Wenyi

2014-01-01

The Anaphase Promoting Complex/Cyclosome (APC/C) is a multi-subunit E3 ubiquitin ligase that primarily governs cell cycle progression. APC/C is composed of at least 14 core subunits and recruits its substrates for ubiquitination via one of the two adaptor proteins, Cdc20 or Cdh1, in M or M/early G1 phase, respectively. Furthermore, recent studies have shed light on crucial functions for APC/C in maintaining genomic integrity, neuronal differentiation, cellular metabolism and tumorigenesis. To gain better insight into the in vivo physiological functions of APC/C in regulating various cellular processes, particularly development and tumorigenesis, a number of mouse models of APC/C core subunits, coactivators or inhibitors have been established and characterized. However, due to their essential role in cell cycle regulation, most of the germline knockout mice targeting the APC/C pathway are embryonic lethal, indicating the need for generating conditional knockout mouse models to assess the role in tumorigenesis for each APC/C signaling component in specific tissues. In this review, we will first provide a brief introduction of the ubiquitin-proteasome system (UPS) and the biochemical activities and cellular functions of the APC/C E3 ligase. We will then focus primarily on characterizing genetic mouse models used to understand the physiological roles of each APC/C signaling component in embryogenesis, cell proliferation, development and carcinogenesis. Finally, we discuss future research directions to further elucidate the physiological contributions of APC/C components during tumorigenesis and validate their potentials as a novel class of anti-cancer targets. PMID:24569229

Cancer Incidence Trends Among Asian American Populations in the United States, 1990–2008

PubMed Central

2013-01-01

Background National cancer incidence trends are presented for eight Asian American groups: Asian Indians/Pakistanis, Chinese, Filipinos, Japanese, Kampucheans, Koreans, Laotians, and Vietnamese. Methods Cancer incidence data from 1990 through 2008 were obtained from 13 Surveillance, Epidemiology, End Results (SEER) registries. Incidence rates from 1990 through 2008 and average percentage change were computed using SEER*Stat and Joinpoint software. The annual percentage change (APC) in incidence rates was estimated with 95% confidence intervals (95% CIs) calculated for both the rate and APC estimates. Rates for non-Hispanic whites are presented for comparison. Results Prostate cancer was the most common malignancy among most groups, followed by lung, colorectal, liver, and stomach cancers. Breast cancer was generally the most common cancer in women, followed by colorectal and lung cancers; liver, cervix, thyroid, and stomach cancers also ranked highly. Among men, increasing trends were observed for prostate (Asian Indians and Pakistanis: APC 1990–2003 = 2.2, 95% CI = 0.3 to 4.1; Filipinos: APC 1990–1994 = 19.0, 95% CI = 4.5 to 35.4; Koreans: APC 1990–2008 = 2.9, 95% CI = 1.8 to 4.0), colorectal (Koreans: APC 1990–2008 = 2.2, 95% CI = 0.9 to 3.5), and liver cancers (Filipinos: APC 1990–2008 = 1.6, 95% CI = 0.4 to 2.7; Koreans: APC 1990–2006 = 2.1, 95% CI = 0.4 to 3.7; Vietnamese: APC 1990–2008 = 1.6, 95% CI = 0.3 to 2.8), whereas lung and stomach cancers generally remained stable or decreased. Among women, increases were observed for uterine cancer (Asian Indians: APC 1990–2008 = 3.0, 95% CI = 0.3 to 5.8; Chinese: APC 2004–2008 = 7.0, 95% CI = 1.4 to 12.9; Filipina: APC 1990–2008 = 3.0, 95% CI = 2.4 to 3.7; Japanese: APC 1990–2008 = 1.1, 95% CI = 0.1 to 2.0), colorectal cancer (Koreans: APC 1990–2008 = 2.8, 95% CI = 1.7 to 3.9; Laotians: APC: 1990–2008 = 5.9, 95% CI = 4.0 to 7.7), lung cancer (Filipinas: APC 1990–2008 = 2.1, 95% CI = 1.4 to 2.8; Koreans: APC 1990–2008 = 2.1, 95% CI = 0.6 to 3.6), thyroid cancer (Filipinas: APC 1990–2008 = 2.5, 95% CI = 1.7 to 3.3), and breast cancer in most groups (APC 1990–2008 from 1.2 among Vietnamese and Chinese to 4.7 among Koreans). Decreases were observed for stomach (Chinese and Japanese), colorectal (Chinese), and cervical cancers (Laotians and Vietnamese). Conclusions These data fill a critical knowledge gap concerning the cancer experience of Asian American groups and highlight where increased preventive, screening, and surveillance efforts are needed—in particular, lung cancer among Filipina and Korean women and Asian Indian/Pakistani men, breast cancer among all women, and liver cancer among Vietnamese, Laotian, and Kampuchean women and Filipino, Kampuchean, and Vietnamese men. PMID:23878350

Compositions and methods for adoptive and active immunotherapy

DOEpatents

Fahmy, Tarek; Steenblock, Erin

2014-01-14

Modular aAPCs and methods of their manufacture and use are provided. The modular aAPCs are constructed from polymeric microparticles. The aAPCs include encapsulated cytokines and coupling agents which modularly couple functional elements including T cell receptor activators, co-stimulatory molecules and adhesion molecules to the particle. The ability of these aAPCs to release cytokines in a controlled manner, coupled with their modular nature and ease of ligand attachment, results in an ideal, tunable APC capable of stimulating and expanding primary T cells.

Evaluation and analysis of SEASAT-A Scanning Multichannel Microwave Radiometer (SMMR) Antenna Pattern Correction (APC) algorithm

NASA Technical Reports Server (NTRS)

Kitzis, J. L.; Kitzis, S. N.

1979-01-01

An evaluation of the versions of the SEASAT-A SMMR antenna pattern correction (APC) algorithm is presented. Two efforts are focused upon in the APC evaluation: the intercomparison of the interim, box, cross, and nominal APC modes; and the development of software to facilitate the creation of matched spacecraft and surface truth data sets which are located together in time and space. The problems discovered in earlier versions of the APC, now corrected, are discussed.

Colorectal cancer chemoprevention: the potential of a selective approach.

PubMed

Ben-Amotz, Oded; Arber, Nadir; Kraus, Sarah

2010-10-01

Colorectal cancer (CRC) is a leading cause of cancer death, and therefore demands special attention. Novel recent approaches for the chemoprevention of CRC focus on selective targeting of key pathways. We review the study by Zhang and colleagues, evaluating a selective approach targeting APC-deficient premalignant cells using retinoid-based therapy and TNF-related apoptosis-inducing ligand (TRAIL). This study demonstrates that induction of TRAIL-mediated death signaling contributes to the chemopreventive value of all-trans-retinyl acetate (RAc) by sensitizing premalignant adenoma cells for apoptosis without affecting normal cells. We discuss these important findings, raise few points that deserve consideration, and may further contribute to the development of RAc-based combination therapies with improved efficacy. The authors clearly demonstrate a synergistic interaction between TRAIL, RAc and APC, which leads to the specific cell death of premalignant target cells. The study adds to the growing body of literature related to CRC chemoprevention, and provides solid data supporting a potentially selective approach for preventing CRC using RAc and TRAIL.

The immunological synapse as a pharmacological target.

PubMed

Francesca, Finetti; Baldari, Cosima T

2018-06-10

The development of T cell mediated immunity relies on the assembly of a highly specialized interface between T cell and antigen presenting cell (APC), known as the immunological synapse (IS). IS assembly is triggered when the T cell receptor (TCR) binds to specific peptide antigen presented in association to the major histocompatibility complex (MHC) by the APC, and is followed by the spatiotemporal dynamic redistribution of TCR, integrins, co-stimulatory receptors and signaling molecules, allowing for the fine-tuning and integration of the signals that lead to T cell activation. The knowledge acquired to date about the mechanisms of IS assembly underscores this structure as a robust pharmacological target. The activity of molecules involved in IS assembly and function can be targeted by specific compounds to modulate the immune response in a number of disorders, including cancers and autoimmune diseases, or in transplanted patients. Here, we will review the state-of-the art of the current therapies which exploit the IS to modulate the immune response. Copyright © 2018. Published by Elsevier Ltd.

Distinct Patterns of Somatic Mosaicism in the APC Gene in Neoplasms From Patients With Unexplained Adenomatous Polyposis.

PubMed

Jansen, Anne M L; Crobach, Stijn; Geurts-Giele, Willemina R R; van den Akker, Brendy E W M; Garcia, Marina Ventayol; Ruano, Dina; Nielsen, Maartje; Tops, Carli M J; Wijnen, Juul T; Hes, Frederik J; van Wezel, Tom; Dinjens, Winand N M; Morreau, Hans

2017-02-01

We investigated the presence and patterns of mosaicism in the APC gene in patients with colon neoplasms not associated with any other genetic variants; we performed deep sequence analysis of APC in at least 2 adenomas or carcinomas per patient. We identified mosaic variants in APC in adenomas from 9 of the 18 patients with 21 to approximately 100 adenomas. Mosaic variants of APC were variably detected in leukocyte DNA and/or non-neoplastic intestinal mucosa of these patients. In a comprehensive sequence analysis of 1 patient, we found no evidence for mosaicism in APC in non-neoplastic intestinal mucosa. One patient was found to carry a mosaic c.4666dupA APC variant in only 10 of 16 adenomas, indicating the importance of screening 2 or more adenomas for genetic variants. Copyright © 2017 AGA Institute. Published by Elsevier Inc. All rights reserved.

Potential use of advanced process control for safety purposes during attack of a process plant.

PubMed

Whiteley, James R

2006-03-17

Many refineries and commodity chemical plants employ advanced process control (APC) systems to improve throughputs and yields. These APC systems utilize empirical process models for control purposes and enable operation closer to constraints than can be achieved with traditional PID regulatory feedback control. Substantial economic benefits are typically realized from the addition of APC systems. This paper considers leveraging the control capabilities of existing APC systems to minimize the potential impact of a terrorist attack on a process plant (e.g., petroleum refinery). Two potential uses of APC are described. The first is a conventional application of APC and involves automatically moving the process to a reduced operating rate when an attack first begins. The second is a non-conventional application and involves reconfiguring the APC system to optimize safety rather than economics. The underlying intent in both cases is to reduce the demands on the operator to allow focus on situation assessment and optimal response planning. An overview of APC is provided along with a brief description of the modifications required for the proposed new applications of the technology.

Transportability, distributability and rehosting experience with a kernel operating system interface set

NASA Technical Reports Server (NTRS)

Blumberg, F. C.; Reedy, A.; Yodis, E.

1986-01-01

For the past two years, PRC has been transporting and installing a software engineering environment framework, the Automated Product control Environment (APCE), at a number of PRC and government sites on a variety of different hardware. The APCE was designed using a layered architecture which is based on a standardized set of interfaces to host system services. This interface set called the APCE Interface Set (AIS), was designed to support many of the same goals as the Common Ada Programming Support Environment (APSE) Interface Set (CAIS). The APCE was developed to provide support for the full software lifecycle. Specific requirements of the APCE design included: automation of labor intensive administrative and logistical tasks: freedom for project team members to use existing tools: maximum transportability for APCE programs, interoperability of APCE database data, and distributability of both processes and data: and maximum performance on a wide variety of operating systems. A brief description is given of the APCE and AIS, a comparison of the AIS and CAIS both in terms of functionality and of philosophy and approach and a presentation of PRC's experience in rehosting AIS and transporting APCE programs and project data. Conclusions are drawn from this experience with respect to both the CAIS efforts and Space Station plans.

Spontaneous Aberrant Crypt Foci in Apc1638N Mice with a Mutant Apc Allele

PubMed Central

Pretlow, Theresa P.; Edelmann, Winfried; Kucherlapati, Raju; Pretlow, Thomas G.; Augenlicht, Leonard H.

2003-01-01

The Apc1638N/+ mouse has a chain-terminating mutation in one allele of the adenomatous polyposis coli (Apc) gene that is similar to most mutations observed in the human familial adenomatous polyposis syndrome. Aberrant crypt foci (ACF), the earliest identified neoplastic lesions in the colon, are morphologically abnormal structures that are identifiedmicroscopically in the grossly normal colonic mucosas of rodents treated with colon carcinogens and of human patients. The colons and cecums of 62 Apc1638N/+ mice were evaluated for the spontaneous occurrence of ACF and tumors. Both male and female mice were killed at different times between 5 and 28 weeks of age. Wild-type littermates, ie, Apc+/+ mice, at 22 to 26 weeks of age served as controls. ACF were identified in 97% of the Apc1638N/+ mice starting at 5 weeks of age and not in any wild-type littermates. Although the number of ACF increased with age (P < 0.0001), the average number of crypts per focus of the ACF did not increase significantly. In addition, wild-type Apc protein was detected by immunohistochemistry in all 22 ACF evaluated. Together these data suggest that heterozygous loss of Apc may be sufficient to initiate ACF in these mice and that these mice may be suitable models to study the interaction of environmental factors with an inherited mutation of the Apc gene that is associated with colon cancer. PMID:14578176

Proteomic analysis reveals APC-dependent post-translational modifications and identifies a novel regulator of β-catenin.

PubMed

Blundon, Malachi A; Schlesinger, Danielle R; Parthasarathy, Amritha; Smith, Samantha L; Kolev, Hannah M; Vinson, David A; Kunttas-Tatli, Ezgi; McCartney, Brooke M; Minden, Jonathan S

2016-07-15

Wnt signaling generates patterns in all embryos, from flies to humans, and controls cell fate, proliferation and metabolic homeostasis. Inappropriate Wnt pathway activation results in diseases, including colorectal cancer. The adenomatous polyposis coli (APC) tumor suppressor gene encodes a multifunctional protein that is an essential regulator of Wnt signaling and cytoskeletal organization. Although progress has been made in defining the role of APC in a normal cellular context, there are still significant gaps in our understanding of APC-dependent cellular function and dysfunction. We expanded the APC-associated protein network using a combination of genetics and a proteomic technique called two-dimensional difference gel electrophoresis (2D-DIGE). We show that loss of Drosophila Apc2 causes protein isoform changes reflecting misregulation of post-translational modifications (PTMs), which are not dependent on β-catenin transcriptional activity. Mass spectrometry revealed that proteins involved in metabolic and biosynthetic pathways, protein synthesis and degradation, and cell signaling are affected by Apc2 loss. We demonstrate that changes in phosphorylation partially account for the altered PTMs in APC mutants, suggesting that APC mutants affect other types of PTM. Finally, through this approach Aminopeptidase P was identified as a new regulator of β-catenin abundance in Drosophila embryos. This study provides new perspectives on the cellular effects of APC that might lead to a deeper understanding of its role in development. © 2016. Published by The Company of Biologists Ltd.

CpG methylation of APC promoter 1A in sporadic and familial breast cancer patients.

PubMed

Debouki-Joudi, Saoussen; Trifa, Fatma; Khabir, Abdelmajid; Sellami-Boudawara, Tahia; Frikha, Mounir; Daoud, Jamel; Mokdad-Gargouri, Raja

2017-01-01

Tumour suppressor gene (TSG) silencing through promoter hypermethylation plays an important role in cancer initiation. The aim of this study was to assess the extent of methylation of APC gene promoter in 91 sporadic and 44 familial cases of Tunisian patients with breast cancer (BC) in. The frequency of APC promoter methylation is somewhat similar for sporadic and familial breast cancer cases, (52.1%, and 54.5% respectively). For sporadic breast cancer patients, there was a significant correlation of APC promoter hypermethylation with TNM stage (p = 0.024) and 3-year survival (p = 0.025). Regarding the hormonal status (HR), we found significant association between negativity to PR and unmethylated APC (p= 0.005) while ER and Her2/neu are not correlated. Moreover, unmethylated APC promoter is more frequent in tumours expressing at least one out the 3 proteins compared to triple negative cases (p= 0.053). On the other hand, aberrant methylation of APC was associated with tumour size (p = 0.036), lymph node (p = 0.028), distant metastasis (p = 0.031), and 3-year survival (p = 0.046) in the group of patients with familial breast cancer. Moreover, patients with sporadic breast cancer displaying the unmethylated profile have a significant prolonged overall survival compared to those with the methylated pattern of APC promoter (p log rank = 0.008). Epigenetic change at the CpG islands in the APC promoter was associated with the silence of its transcript and the loss of protein expression suggesting that this event is the main mechanism regulating the APC expression in breast cancer. In conclusion, our data showed that the loss of APC through aberrant methylation is associated with the aggressive behavior of both sporadic and familial breast cancer in Tunisian patients.

An APC:WNT Counter-Current-Like Mechanism Regulates Cell Division Along the Human Colonic Crypt Axis: A Mechanism That Explains How APC Mutations Induce Proliferative Abnormalities That Drive Colon Cancer Development

PubMed Central

Boman, Bruce M.; Fields, Jeremy Z.

2013-01-01

APC normally down-regulates WNT signaling in human colon, and APC mutations cause proliferative abnormalities in premalignant crypts leading to colon cancer, but the mechanisms are unclear at the level of spatial and functional organization of the crypt. Accordingly, we postulated a counter-current-like mechanism based on gradients of factors (APC;WNT) that regulate colonocyte proliferation along the crypt axis. During crypt renewal, stem cells (SCs) at the crypt bottom generate non-SC daughter cells that proliferate and differentiate while migrating upwards. The APC concentration is low at the crypt bottom and high at the top (where differentiated cells reside). WNT signaling, in contrast, is high at the bottom (where SCs reside) and low at the top. Given that WNT and APC gradients are counter to one another, we hypothesized that a counter-current-like mechanism exists. Since both APC and WNT signaling components (e.g., survivin) are required for mitosis, this mechanism establishes a zone in the lower crypt where conditions are optimal for maximal cell division and mitosis orientation (symmetric versus asymmetric). APC haploinsufficiency diminishes the APC gradient, shifts the proliferative zone upwards, and increases symmetric division, which causes SC overpopulation. In homozygote mutant crypts, these changes are exacerbated. Thus, APC-mutation-induced changes in the counter-current-like mechanism cause expansion of proliferative populations (SCs, rapidly proliferating cells) during tumorigenesis. We propose this mechanism also drives crypt fission, functions in the crypt cycle, and underlies adenoma development. Novel chemoprevention approaches designed to normalize the two gradients and readjust the proliferative zone downwards, might thwart progression of these premalignant changes. PMID:24224156

A Minimal Anaphase Promoting Complex/Cyclosome (APC/C) in Trypanosoma brucei

PubMed Central

Bessat, Mohamed; Knudsen, Giselle; Burlingame, Alma L.; Wang, Ching C.

2013-01-01

The anaphase-promoting complex/cyclosome (APC/C) is a multi-subunit E3 ubiquitin ligase that initiates chromosome segregation and mitotic exit by targeting critical cell-cycle regulators for proteolytic destruction. Previously, seven APC/C subunit homologues were identified in the genome of Trypanosoma brucei. In the present study, we tested five of them in yeast complementation studies and found none of them capable of complementing the yeast mutants lacking the corresponding subunits, suggesting significant discrepancies between the two APC/C’s. Subunit homologues of mitotic checkpoint complex (MCC) have not yet been identified in T. brucei, raising the possibility that a MCC-APC/C complex equivalent may not exist in T. brucei. We performed tandem affinity purification of the protein complex containing a APC1 fusion protein expressed in the cells enriched in different phases of the cell cycle of procyclic form T. brucei, and compared their protein profiles using LC-MS/MS analyses. The seven putative APC/C subunits were identified in the protein complex throughout the cell cycle together with three additional proteins designated the associated proteins (AP) AP1, AP2 and AP3. Abundance of the 10 proteins remained relatively unchanged throughout the cell cycle, suggesting that they are the core subunits of APC/C. AP1 turned out to be a homologue of APC4. An RNAi knockdown of APC4 and AP3 showed no detectable cellular phenotype, whereas an AP2 knockdown enriched the cells in G2/M phase. The AP2-depleted cells showed stabilized mitotic cyclin B. An accumulation of poly-ubiquitinated cyclin B was indicated in the cells treated with the proteasome inhibitor MG132, demonstrating the involvement of proteasome in degrading poly-ubiquitinated cyclin B. In all, a 10-subunit APC/C machinery with a conserved function is identified in T. brucei without linking to a MCC-like complex, thus indicating a unique T. brucei APC/C. PMID:23533609

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

Tooker, Brian C.; Brindley, Stephen M.; Chiarappa-Zucca, Marina L.

We report that exposure to small amounts of beryllium (Be) can result in beryllium sensitization and progression to Chronic Beryllium Disease (CBD). In CBD, beryllium is presented to Be-responsive T-cells by professional antigen-presenting cells (APC). This presentation drives T-cell proliferation and pro-inflammatory cytokine (IL-2, TNFα, and IFNγ) production and leads to granuloma formation. The mechanism by which beryllium enters an APC and is processed to become part of the beryllium antigen complex has not yet been elucidated. Developing techniques for beryllium detection with enough sensitivity has presented a barrier to further investigation. The objective of this study was to demonstratemore » that Accelerator Mass Spectrometry (AMS) is sensitive enough to quantify the amount of beryllium presented by APC to stimulate Be-responsive T-cells. To achieve this goal, APC - which may or may not stimulate Be-responsive T-cells - were cultured with Be-ferritin. Then, by utilizing AMS, the amount of beryllium processed for presentation was determined. Further, IFNγ intracellular cytokine assays were performed to demonstrate that Be-ferritin (at levels used in the experiments) could stimulate Be-responsive T-cells when presented by an APC of the correct HLA type (HLA-DP0201). The results indicated that Be-responsive T-cells expressed IFNγ only when APC with the correct HLA type were able to process Be for presentation. Utilizing AMS, we determined that APC with HLA-DP0201 had membrane fractions containing 0.17-0.59 ng Be and APC with HLA-DP0401 had membrane fractions bearing 0.40-0.45 ng Be. However, HLA-DP0401 APC had 20-times more Be associated with the whole cells (57.68-61.12 ng) then HLA-DP0201 APC (0.90-3.49 ng). As these findings demonstrate, AMS detection of picogram levels of Be processed by APC is possible. Further, regardless of form, Be requires processing by APC to successfully stimulate Be-responsive T-cells to generate IFNγ.« less

The Saccharomyces cerevisiae anaphase-promoting complex interacts with multiple histone-modifying enzymes to regulate cell cycle progression.

PubMed

Turner, Emma L; Malo, Mackenzie E; Pisclevich, Marnie G; Dash, Megan D; Davies, Gerald F; Arnason, Terra G; Harkness, Troy A A

2010-10-01

The anaphase-promoting complex (APC), a large evolutionarily conserved ubiquitin ligase complex, regulates cell cycle progression through mitosis and G(1). Here, we present data suggesting that APC-dependent cell cycle progression relies on a specific set of posttranslational histone-modifying enzymes. Multiple APC subunit mutants were impaired in total and modified histone H3 protein content. Acetylated H3K56 (H3K56(Ac)) levels were as reduced as those of total H3, indicating that loading histones with H3K56(Ac) is unaffected in APC mutants. However, under restrictive conditions, H3K9(Ac) and dimethylated H3K79 (H3K79(me2)) levels were more greatly reduced than those of total H3. In a screen for histone acetyltransferase (HAT) and histone deacetylase (HDAC) mutants that genetically interact with the apc5(CA) (chromatin assembly) mutant, we found that deletion of GCN5 or ELP3 severely hampered apc5(CA) temperature-sensitive (ts) growth. Further analyses showed that (i) the elp3Δ gcn5Δ double mutant ts defect was epistatic to that observed in apc5(CA) cells; (ii) gcn5Δ and elp3Δ mutants accumulate in mitosis; and (iii) turnover of the APC substrate Clb2 is not impaired in elp3Δ gcn5Δ cells. Increased expression of ELP3 and GCN5, as well as genes encoding the HAT Rtt109 and the chromatin assembly factors Msi1 and Asf1, suppressed apc5(CA) defects, while increased APC5 expression partially suppressed elp3Δ gcn5Δ growth defects. Finally, we demonstrate that Gcn5 is unstable during G(1) and following G(1) arrest and is stabilized in APC mutants. We present our working model in which Elp3/Gcn5 and the APC work together to facilitate passage through mitosis and G(1). To progress into S, we propose that at least Gcn5 must then be targeted for degradation in an APC-dependent fashion.

Correlation between mutations and mRNA expression of APC and MUTYH genes: new insight into hereditary colorectal polyposis predisposition.

PubMed

Aceto, Gitana Maria; Fantini, Fabiana; De Iure, Sabrina; Di Nicola, Marta; Palka, Giandomenico; Valanzano, Rosa; Di Gregorio, Patrizia; Stigliano, Vittoria; Genuardi, Maurizio; Battista, Pasquale; Cama, Alessandro; Curia, Maria Cristina

2015-10-28

Transcript dosage imbalance may influence the transcriptome. To gain insight into the role of altered gene expression in hereditary colorectal polyposis predisposition, in the present study we analyzed absolute and allele-specific expression (ASE) of adenomatous polyposis coli (APC) and mutY Homolog (MUTYH) genes. We analyzed DNA and RNA extracted from peripheral blood mononuclear cells (PBMC) of 49 familial polyposis patients and 42 healthy blood donors selected according similar gender and age. Patients were studied for germline alterations in both genes using dHPLC, MLPA and automated sequencing. APC and MUTYH mRNA expression levels were investigated by quantitative Real-Time PCR (qRT-PCR) analysis using TaqMan assay and by ASE assays using dHPLC-based primer extension. Twenty out of 49 patients showed germline mutations: 14 in APC gene and six in MUTYH gene. Twenty-nine patients did not show mutations in both genes. Results from qRT-PCR indicated that gene expression of both APC and MUTYH was reduced in patients analyzed. In particular, a significant reduction in APC expression was observed in patients without APC germline mutation vs control group (P < 0.05) while APC expression in the mutation carrier patients, although lower compared to control individuals, did not show statistical significance. On the other hand a significant reduced MUTYH expression was detected in patients with MUTYH mutations vs control group (P < 0.05). Altered ASE of APC was detected in four out of eight APC mutation carriers. In particular one case showed a complete loss of one allele. Among APC mutation negative cases, 4 out of 13 showed a moderate ASE. ASE of MUTYH did not show any altered expression in the cases analyzed. Spearman's Rho Test analysis showed a positive and significant correlation between APC and MUTYH genes both in cases and in controls (P = 0.020 and P < 0.001). APC and MUTYH showed a reduced germline expression, not always corresponding to gene mutation. Expression of APC is decreased in mutation negative cases and this appears to be a promising indicator of FAP predisposition, while for MUTYH gene, mutation is associated to reduced mRNA expression. This study could improve the predictive genetic diagnosis of at-risk individuals belonging to families with reduced mRNA expression regardless of presence of mutation.

Jagged1 is the pathological link between Wnt and Notch pathways in colorectal cancer.

PubMed

Rodilla, Verónica; Villanueva, Alberto; Obrador-Hevia, Antonia; Robert-Moreno, Alex; Fernández-Majada, Vanessa; Grilli, Andrea; López-Bigas, Nuria; Bellora, Nicolás; Albà, M Mar; Torres, Ferran; Duñach, Mireia; Sanjuan, Xavier; Gonzalez, Sara; Gridley, Thomas; Capella, Gabriel; Bigas, Anna; Espinosa, Lluís

2009-04-14

Notch has been linked to beta-catenin-dependent tumorigenesis; however, the mechanisms leading to Notch activation and the contribution of the Notch pathway to colorectal cancer is not yet understood. By microarray analysis, we have identified a group of genes downstream of Wnt/beta-catenin (down-regulated when blocking Wnt/beta-catenin) that are directly regulated by Notch (repressed by gamma-secretase inhibitors and up-regulated by active Notch1 in the absence of beta-catenin signaling). We demonstrate that Notch is downstream of Wnt in colorectal cancer cells through beta-catenin-mediated transcriptional activation of the Notch-ligand Jagged1. Consistently, expression of activated Notch1 partially reverts the effects of blocking Wnt/beta-catenin pathway in tumors implanted s.c. in nude mice. Crossing APC(Min/+) with Jagged1(+/Delta) mice is sufficient to significantly reduce the size of the polyps arising in the APC mutant background indicating that Notch is an essential modulator of tumorigenesis induced by nuclear beta-catenin. We show that this mechanism is operating in human tumors from Familial Adenomatous Polyposis patients. We conclude that Notch activation, accomplished by beta-catenin-mediated up-regulation of Jagged1, is required for tumorigenesis in the intestine. The Notch-specific genetic signature is sufficient to block differentiation and promote vasculogenesis in tumors whereas proliferation depends on both pathways.

Production of CXC and CC chemokines by human antigen-presenting cells in response to Lassa virus or closely related immunogenic viruses, and in cynomolgus monkeys with lassa fever.

PubMed

Pannetier, Delphine; Reynard, Stéphanie; Russier, Marion; Carnec, Xavier; Baize, Sylvain

2014-01-01

The pathogenesis of Lassa fever (LF), a hemorrhagic fever endemic to West Africa, remains unclear. We previously compared Lassa virus (LASV) with its genetically close, but nonpathogenic homolog Mopeia virus (MOPV) and demonstrated that the strong activation of antigen-presenting cells (APC), including type I IFN production, observed in response to MOPV probably plays a crucial role in controlling infection. We show here that human macrophages (MP) produce large amounts of CC and CXC chemokines in response to MOPV infection, whereas dendritic cells (DC) release only moderate amounts of CXC chemokines. However, in the presence of autologous T cells, DCs produced CC and CXC chemokines. Chemokines were produced in response to type I IFN synthesis, as the levels of both mediators were strongly correlated and the neutralization of type I IFN resulted in an inhibition of chemokine production. By contrast, LASV induced only low levels of CXCL-10 and CXCL-11 production. These differences in chemokine production may profoundly affect the generation of virus-specific T-cell responses and may therefore contribute to the difference of pathogenicity between these two viruses. In addition, a recombinant LASV (rLASV) harboring the NP-D389A/G392A mutations, which abolish the inhibition of type I IFN response by nucleoprotein (NP), induced the massive synthesis of CC and CXC chemokines in both DC and MP, confirming the crucial role of arenavirus NP in immunosuppression and pathogenicity. Finally, we confirmed, using PBMC samples and lymph nodes obtained from LASV-infected cynomolgus monkeys, that LF was associated with high levels of CXC chemokine mRNA synthesis, suggesting that the very early synthesis of these mediators may be correlated with a favourable outcome.

Evaluation of optimal DNA staining for triggering by scanning fluorescence microscopy (SFM)

NASA Astrophysics Data System (ADS)

Mittag, Anja; Marecka, Monika; Pierzchalski, Arkadiusz; Malkusch, Wolf; Bocsi, József; Tárnok, Attila

2009-02-01

In imaging and flow cytometry, DNA staining is a common trigger signal for cell identification. Selection of the proper DNA dye is restricted by the hardware configuration of the instrument. The Zeiss Imaging Solutions GmbH (München, Germany) introduced a new automated scanning fluorescence microscope - SFM (Axio Imager.Z1) which combines fluorescence imaging with cytometric parameters measurement. The aim of the study was to select optimal DNA dyes as trigger signal in leukocyte detection and subsequent cytometric analysis of double-labeled leukocytes by SFM. Seven DNA dyes (DAPI, Hoechst 33258, Hoechst 33342, POPO-3, PI, 7-AAD, and TOPRO-3) were tested and found to be suitable for the implemented filtersets (fs) of the SFM (fs: 49, fs: 44, fs: 20). EDTA blood was stained after erythrocyte lysis with DNA dye. Cells were transferred on microscopic slides and embedded in fluorescent mounting medium. Quality of DNA fluorescence signal as well as spillover signals were analyzed by SFM. CD45-APC and CD3-PE as well as CD4-FITC and CD8-APC were selected for immunophenotyping and used in combination with Hoechst. Within the tested DNA dyes DAPI showed relatively low spillover and the best CV value. Due to the low spillover of UV DNA dyes a triple staining of Hoechst and APC and PE (or APC and FITC, respectively) could be analyzed without difficulty. These results were confirmed by FCM measurements. DNA fluorescence is applicable for identifying and triggering leukocytes in SFM analyses. Although some DNA dyes exhibit strong spillover in other fluorescence channels, it was possible to immunophenotype leukocytes. DAPI seems to be best suitable for use in the SFM system and will be used in protocol setups as primary parameter.

Highly purified eicosapentaenoic acid as free fatty acids strongly suppresses polyps in Apc(Min/+) mice.

PubMed

Fini, Lucia; Piazzi, Giulia; Ceccarelli, Claudio; Daoud, Yahya; Belluzzi, Andrea; Munarini, Alessandra; Graziani, Giulia; Fogliano, Vincenzo; Selgrad, Michael; Garcia, Melissa; Gasbarrini, Antonio; Genta, Robert M; Boland, C Richard; Ricciardiello, Luigi

2010-12-01

Although cyclooxygenase (COX)-2 inhibitors could represent the most effective chemopreventive tool against colorectal cancer (CRC), their use in clinical practice is hampered by cardiovascular side effects. Consumption of ω-3-polyunsaturated fatty acids (ω-3-PUFAs) is associated with a reduced risk of CRC. Therefore, in this study, we assessed the efficacy of a novel 99% pure preparation of ω-3-PUFA eicosapentaenoic acid as free fatty acids (EPA-FFA) on polyps in Apc(Min/+) mice. Apc(Min/+) and corresponding wild-type mice were fed control diet (Ctrl) or diets containing either EPA-FFA 2.5% or 5%, for 12 weeks while monitoring food intake and body weight. We found that both EPA-FFA diets protected from the cachexia observed among Apc(Min/+) animals fed Ctrl diet (P < 0.0054), without toxic effect, in conjunction with a significant decrease in lipid peroxidation in the treated arms. Moreover, both EPA-FFA diets dramatically suppressed polyp number (by 71.5% and 78.6%, respectively; P < 0.0001) and load (by 82.5% and 93.4%, respectively; P < 0.0001) in both small intestine and colon. In addition, polyps less than 1 mm in size were predominantly found in the EPA-FFA 5% arm whereas those 1 to 3 mm in size were more frequent in the Ctrl arm (P < 0.0001). Interestingly, in the EPA-FFA groups, mucosal arachidonic acid was replaced by EPA (P < 0.0001), leading to a significant reduction in COX-2 expression and β-catenin nuclear translocation. Moreover, in the EPA-FFA arms, we found a significant decrease in proliferation throughout the intestine together with an increase in apoptosis. Our data make 99% pure EPA-FFA an excellent candidate for CRC chemoprevention. ©2010 AACR.

Dietary fat overcomes the protective activity of thrombospondin-1 signaling in the Apc(Min/+) model of colon cancer.

PubMed

Soto-Pantoja, D R; Sipes, J M; Martin-Manso, G; Westwood, B; Morris, N L; Ghosh, A; Emenaker, N J; Roberts, D D

2016-05-30

Thrombospondin 1 is a glycoprotein that regulates cellular phenotype through interactions with its cellular receptors and extracellular matrix-binding partners. Thrombospondin 1 locally regulates angiogenesis and inflammatory responses that contribute to colorectal carcinogenesis in Apc(Min/+) mice. The ability of thrombospondin 1 to regulate responses of cells and tissues to a variety of stresses suggested that loss of thrombospondin 1 may also have broader systemic effects on metabolism to modulate carcinogenesis. Apc(Min/+):Thbs1(-/-) mice exhibited decreased survival and higher tumor multiplicities in the small and large intestine relative to Apc(Min/+) mice when fed a low (5%) fat western diet. However, the protective effect of endogenous thrombospondin 1 was lost when the mice were fed a western diet containing 21% fat. Biochemical profiles of liver tissue identified systemic metabolic changes accompanying the effects of thrombospondin 1 and dietary lipid intake on tumorigenesis. A high-fat western diet differentially regulated elements of amino acid, energy and lipid metabolism in Apc(Min/+):Thbs1(-/-) mice relative to Apc(Min/+):Thbs1(+/+)mice. Metabolic changes in ketone body and tricarboxylic acid cycle intermediates indicate functional interactions between Apc and thrombospondin 1 signaling that control mitochondrial function. The cumulative diet-dependent differential changes observed in Apc(Min/+):Thbs1(-/-) versus Apc(Min/+) mice include altered amino acid and lipid metabolism, mitochondrial dysfunction, eicosanoids and ketone body formation. This metabolic profile suggests that the protective role of thrombospondin 1 to decrease adenoma formation in Apc(Min/+) mice results in part from improved mitochondrial function.

Somatic APC mosaicism and oligogenic inheritance in genetically unsolved colorectal adenomatous polyposis patients.

PubMed

Ciavarella, Michele; Miccoli, Sara; Prossomariti, Anna; Pippucci, Tommaso; Bonora, Elena; Buscherini, Francesco; Palombo, Flavia; Zuntini, Roberta; Balbi, Tiziana; Ceccarelli, Claudio; Bazzoli, Franco; Ricciardiello, Luigi; Turchetti, Daniela; Piazzi, Giulia

2018-03-01

Germline variants in the APC gene cause familial adenomatous polyposis. Inherited variants in MutYH, POLE, POLD1, NTHL1, and MSH3 genes and somatic APC mosaicism have been reported as alternative causes of polyposis. However, ~30-50% of cases of polyposis remain genetically unsolved. Thus, the aim of this study was to investigate the genetic causes of unexplained adenomatous polyposis. Eight sporadic cases with >20 adenomatous polyps by 35 years of age or >50 adenomatous polyps by 55 years of age, and no causative germline variants in APC and/or MutYH, were enrolled from a cohort of 56 subjects with adenomatous colorectal polyposis. APC gene mosaicism was investigated on DNA from colonic adenomas by Sanger sequencing or Whole Exome Sequencing (WES). Mosaicism extension to other tissues (peripheral blood, saliva, hair follicles) was evaluated using Sanger sequencing and/or digital PCR. APC second hit was investigated in adenomas from mosaic patients. WES was performed on DNA from peripheral blood to identify additional polyposis candidate variants. We identified APC mosaicism in 50% of patients. In three cases mosaicism was restricted to the colon, while in one it also extended to the duodenum and saliva. One patient without APC mosaicism, carrying an APC in-frame deletion of uncertain significance, was found to harbor rare germline variants in OGG1, POLQ, and EXO1 genes. In conclusion, our restrictive selection criteria improved the detection of mosaic APC patients. In addition, we showed for the first time that an oligogenic inheritance of rare variants might have a cooperative role in sporadic colorectal polyposis onset.

High-resolution Melting Analysis for Gene Scanning of Adenomatous Polyposis Coli (APC) Gene With Oral Squamous Cell Carcinoma Samples.

PubMed

Chang, Ya-Sian; Lin, Chien-Yu; Yang, Shu-Fen; Ho, Cheng Mao; Chang, Jan-Gowth

2016-02-01

There have been many different mutations reported for the large adenomatous polyposis coli (APC) tumor suppressor gene. APC mutations result in inactivation of APC tumor suppressor action, allowing the progression of tumorigenesis. The present study utilized a highly efficient method to identify APC mutations and investigated the association between the APC genetic variants Y486Y, A545A, T1493T, and D1822V and susceptibility to oral squamous cell carcinoma (OSCC). High-resolution melting (HRM) analysis was used to characterize APC mutations. Genomic DNA was extracted from 83 patient specimens of OSCC and 50 blood samples from healthy control subjects. The 14 exons and mutation cluster region of exon 15 were screened by HRM analysis. All mutations were confirmed by direct DNA sequencing. Three mutations and 4 single nucleotide polymorphisms (SNPs) were found in this study. The mutations were c.573T>C (Y191Y) in exon 5, c.1005A>G (L335L) in exon 9, and c.1488A>T (T496T) in exon 11. Two SNPs, c.4479G>A (T1493T) and c.5465A>T (D1822V), were located in exon 15, whereas c.1458T>C (Y486Y) and c.1635G>A (A545A) were located in exon 11 and 13, respectively. There was no observed association between OSCC risk and genotype for any of the 4 APC SNPs. The mutation of APC is rare in Taiwanese patients with OSCC. HRM analysis is a reliable, accurate, and fast screening method for APC mutations.

A novel system of artificial antigen-presenting cells efficiently stimulates Flu peptide-specific cytotoxic T cells in vitro

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

Han, Hui; Peng, Ji-Run, E-mail: pengjr@medmail.com.cn; Chen, Peng-Cheng

Highlights: {yields} Adoptive immunotherapy depends on relevant numbers of cytolytic T lymphocytes. {yields} An ideal artificial APCs system was successfully prepared in vivo. {yields} Controlled release of IL-2 leads to much more T-cell expansion. {yields} This system is better than general cellular APCs on T-cell expansion. -- Abstract: Therapeutic numbers of antigen-specific cytotoxic T lymphocytes (CTLs) are key effectors in successful adoptive immunotherapy. However, efficient and reproducible methods to meet the qualification remain poor. To address this issue, we designed the artificial antigen-presenting cell (aAPC) system based on poly(lactic-co-glycolic acid) (PLGA). A modified emulsion method was used for the preparationmore » of PLGA particles encapsulating interleukin-2 (IL-2). Biotinylated molecular ligands for recognition and co-stimulation of T cells were attached to the particle surface through the binding of avidin-biotin. These formed the aAPC system. The function of aAPCs in the proliferation of specific CTLs against human Flu antigen was detected by enzyme-linked immunospot assay (ELISPOT) and MTT staining methods. Finally, we successfully prepared this suitable aAPC system. The results show that IL-2 is released from aAPCs in a sustained manner over 30 days. This dramatically improves the stimulatory capacity of this system as compared to the effect of exogenous addition of cytokine. In addition, our aAPCs promote the proliferation of Flu antigen-specific CTLs more effectively than the autologous cellular APCs. Here, this aAPC platform is proved to be suitable for expansion of human antigen-specific T cells.« less

Novel mutations and phenotypic associations identified through APC, MUTYH, NTHL1, POLD1, POLE gene analysis in Indian Familial Adenomatous Polyposis cohort.

PubMed

Khan, Nikhat; Lipsa, Anuja; Arunachal, Gautham; Ramadwar, Mukta; Sarin, Rajiv

2017-05-22

Colo-Rectal Cancer is a common cancer worldwide with 5-10% cases being hereditary. Familial Adenomatous Polyposis (FAP) syndrome is due to germline mutations in the APC or rarely MUTYH gene. NTHL1, POLD1, POLE have been recently reported in previously unexplained FAP cases. Unlike the Caucasian population, FAP phenotype and its genotypic associations have not been widely studied in several geoethnic groups. We report the first FAP cohort from South Asia and the only non-Caucasian cohort with comprehensive analysis of APC, MUTYH, NTHL1, POLD1, POLE genes. In this cohort of 112 individuals from 53 FAP families, we detected germline APC mutations in 60 individuals (45 families) and biallelic MUTYH mutations in 4 individuals (2 families). No NTHL1, POLD1, POLE mutations were identified. Fifteen novel APC mutations and a new Indian APC mutational hotspot at codon 935 were identified. Eight very rare FAP phenotype or phenotypes rarely associated with mutations outside specific APC regions were observed. APC genotype-phenotype association studies in different geo-ethnic groups can enrich the existing knowledge about phenotypic consequences of distinct APC mutations and guide counseling and risk management in different populations. A stepwise cost-effective mutation screening approach is proposed for genetic testing of south Asian FAP patients.

New Functions of APC/C Ubiquitin Ligase in the Nervous System and Its Role in Alzheimer's Disease.

PubMed

Fuchsberger, Tanja; Lloret, Ana; Viña, Jose

2017-05-14

The E3 ubiquitin ligase Anaphase Promoting Complex/Cyclosome (APC/C) regulates important processes in cells, such as the cell cycle, by targeting a set of substrates for degradation. In the last decade, APC/C has been related to several major functions in the nervous system, including axon guidance, synaptic plasticity, neurogenesis, and neuronal survival. Interestingly, some of the identified APC/C substrates have been related to neurodegenerative diseases. There is an accumulation of some degradation targets of APC/C in Alzheimer's disease (AD) brains, which suggests a dysregulation of the protein complex in the disorder. Moreover, recently evidence has been provided for an inactivation of APC/C in AD. It has been shown that oligomers of the AD-related peptide, Aβ, induce degradation of the APC/C activator subunit cdh1, in vitro in neurons in culture and in vivo in the mouse hippocampus. Furthermore, in the AD mouse model APP/PS1, lower cdh1 levels were observed in pyramidal neurons in CA1 when compared to age-matched wildtype mice. In this review, we provide a complete list of APC/C substrates that are involved in the nervous system and we discuss their functions. We also summarize recent studies that show neurobiological effects in cdh1 knockout mouse models. Finally, we discuss the role of APC/C in the pathophysiology of AD.

High-resolution melting (HRM) re-analysis of a polyposis patients cohort reveals previously undetected heterozygous and mosaic APC gene mutations.

PubMed

Out, Astrid A; van Minderhout, Ivonne J H M; van der Stoep, Nienke; van Bommel, Lysette S R; Kluijt, Irma; Aalfs, Cora; Voorendt, Marsha; Vossen, Rolf H A M; Nielsen, Maartje; Vasen, Hans F A; Morreau, Hans; Devilee, Peter; Tops, Carli M J; Hes, Frederik J

2015-06-01

Familial adenomatous polyposis is most frequently caused by pathogenic variants in either the APC gene or the MUTYH gene. The detection rate of pathogenic variants depends on the severity of the phenotype and sensitivity of the screening method, including sensitivity for mosaic variants. For 171 patients with multiple colorectal polyps without previously detectable pathogenic variant, APC was reanalyzed in leukocyte DNA by one uniform technique: high-resolution melting (HRM) analysis. Serial dilution of heterozygous DNA resulted in a lowest detectable allelic fraction of 6% for the majority of variants. HRM analysis and subsequent sequencing detected pathogenic fully heterozygous APC variants in 10 (6%) of the patients and pathogenic mosaic variants in 2 (1%). All these variants were previously missed by various conventional scanning methods. In parallel, HRM APC scanning was applied to DNA isolated from polyp tissue of two additional patients with apparently sporadic polyposis and without detectable pathogenic APC variant in leukocyte DNA. In both patients a pathogenic mosaic APC variant was present in multiple polyps. The detection of pathogenic APC variants in 7% of the patients, including mosaics, illustrates the usefulness of a complete APC gene reanalysis of previously tested patients, by a supplementary scanning method. HRM is a sensitive and fast pre-screening method for reliable detection of heterozygous and mosaic variants, which can be applied to leukocyte and polyp derived DNA.

Using genipin-crosslinked acellular porcine corneal stroma for cosmetic corneal lens implants.

PubMed

Liu, Zhao; Zhou, Qiang; Zhu, Jixiang; Xiao, Jianhui; Wan, Pengxia; Zhou, Chenjing; Huang, Zheqian; Qiang, Na; Zhang, Wei; Wu, Zheng; Quan, Daping; Wang, Zhichong

2012-10-01

Acellular porcine corneal stroma (APCS) has been proven to maintain the matrix microenvironment and is therefore an ideal biomaterial for the repair and reconstruction of corneal stroma. This study aims to develop a method to prepare cosmetic corneal lens implants for leukoma using genipin-crosslinked APCS (Gc-APCS). The Gc-APCS was prepared from APCS immersed in 1.0% genipin aqueous solution (pH 5.5) for 4 h at 37 °C, followed by lyophilization at -10 °C. The color of the Gc-APCS gradually deepened to dark-blue. The degree of crosslinking was 45.7 ± 4.6%, measured by the decrease of basic and hydroxy amino acids. The porous structure and ultrastructure of collagenous lamellae were maintained, and the porosity and BET SSA were 72.7 ± 4.6% and 23.01 ± 3.45 m(2)/g, respectively. The Gc-APCS rehydrated to the physiological water content within 5 min and was highly resistant to collagenase digestion. There were no significant differences in the areal modulus and curvature variation between Gc-APCS and nature porcine cornea. The dark-blue pigments were stable to pH, light and implantation in vivo. Gc-APCS extracts had no inhibitory effects on the proliferation of keratocytes. Corneal neovascularization, graft degradation and corneal rejection were not observed within 6 months. Copyright © 2012 Elsevier Ltd. All rights reserved.

PARK2-dependent mitophagy induced by acidic postconditioning protects against focal cerebral ischemia and extends the reperfusion window.

PubMed

Shen, Zhe; Zheng, Yanrong; Wu, Jiaying; Chen, Ying; Wu, Xiaoli; Zhou, Yiting; Yuan, Yang; Lu, Shousheng; Jiang, Lei; Qin, Zhenghong; Chen, Zhong; Hu, Weiwei; Zhang, Xiangnan

2017-03-04

Prompt reperfusion after cerebral ischemia is critical for neuronal survival. Any strategies that extend the limited reperfusion window will be of great importance. Acidic postconditioning (APC) is a mild acidosis treatment that involves inhaling CO 2 during reperfusion following ischemia. APC attenuates ischemic brain injury although the underlying mechanisms have not been elucidated. Here we report that APC reinforces ischemia-reperfusion-induced mitophagy in middle cortical artery occlusion (MCAO)-treated mice, and in oxygen-glucose deprivation (OGD)-treated brain slices and neurons. Inhibition of mitophagy compromises neuroprotection conferred by APC. Furthermore, mitophagy and neuroprotection are abolished in Park2 knockout mice, indicating that APC-induced mitophagy is facilitated by the recruitment of PARK2 to mitochondria. Importantly, in MCAO mice, APC treatment extended the effective reperfusion window from 2 to 4 h, and this window was further extended to 6 h by exogenously expressing PARK2. Taken together, we found that PARK2-dependent APC-induced mitophagy renders the brain resistant to ischemic injury. APC treatment could be a favorable strategy to extend the thrombolytic time window for stroke therapy.

Antigen targeting to antigen-presenting cells enhances presentation to class II-restricted T lymphocytes.

PubMed Central

Scardino, A; Paroli, M; De Petrillo, G; Michel, M L; Barnaba, V

1994-01-01

Receptor-mediated uptake increases by several orders of magnitude the efficiency of APC to internalize Ag, and is stringently required for the Ag-presenting function of T lymphocytes due to their inability to take up Ag non-specifically. We have previously reported that hepatitis B envelope antigen (HBenvAg) can be internalized by T cells via transferrin receptor (TfR). To evaluate if Ag targeting to receptors expressed on APC could be an effective tool for promoting Ag uptake and presentation, we tested the capacity of activated T cells not expressing TfR to induce HBenvAg-specific T-cell responses when pulsed with a hybrid particle containing HBenvAg coupled to gp120 of human immunodeficiency virus (HIV), exploiting the ability of gp120 to bind to CD4 receptor. We found that CD4+/TfR- T cells pulsed either with the hybrid particle or peptide (S193-207) but not with S, L Ag, a recombinant form of HBenvAg, induced a specific proliferative response of a T-cell clone recognizing peptide (S193-207) of HBenvAg. The finding that the addition of anti-CD4 monoclonal antibody (mAb) before the pulsing of CD4+/TfR- T cells with the hybrid particle drastically blocked the specific T-cell response, together with the finding that CD8+/TfR- T cells were unable to serve as APC even if pulsed with this molecule, demonstrated that CD4 receptor was crucial for the HBenvAg internalization. On the other hand, HBenvAg presentation by CD4+/TfR+ T cells pulsed with the hybrid particle was inhibited only when both anti-CD4 and anti-TfR were added before the pulsing. These results suggest that Ag targeting to APC receptors may be usefully exploited to improve Ag-presentation efficiency in potential immunotherapeutic approaches. PMID:7907575

Building a pseudo-atomic model of the anaphase-promoting complex.

PubMed

Kulkarni, Kiran; Zhang, Ziguo; Chang, Leifu; Yang, Jing; da Fonseca, Paula C A; Barford, David

2013-11-01

The anaphase-promoting complex (APC/C) is a large E3 ubiquitin ligase that regulates progression through specific stages of the cell cycle by coordinating the ubiquitin-dependent degradation of cell-cycle regulatory proteins. Depending on the species, the active form of the APC/C consists of 14-15 different proteins that assemble into a 20-subunit complex with a mass of approximately 1.3 MDa. A hybrid approach of single-particle electron microscopy and protein crystallography of individual APC/C subunits has been applied to generate pseudo-atomic models of various functional states of the complex. Three approaches for assigning regions of the EM-derived APC/C density map to specific APC/C subunits are described. This information was used to dock atomic models of APC/C subunits, determined either by protein crystallography or homology modelling, to specific regions of the APC/C EM map, allowing the generation of a pseudo-atomic model corresponding to 80% of the entire complex.

Adaptive Packet Combining Scheme in Three State Channel Model

NASA Astrophysics Data System (ADS)

Saring, Yang; Bulo, Yaka; Bhunia, Chandan Tilak

2018-01-01

The two popular techniques of packet combining based error correction schemes are: Packet Combining (PC) scheme and Aggressive Packet Combining (APC) scheme. PC scheme and APC scheme have their own merits and demerits; PC scheme has better throughput than APC scheme, but suffers from higher packet error rate than APC scheme. The wireless channel state changes all the time. Because of this random and time varying nature of wireless channel, individual application of SR ARQ scheme, PC scheme and APC scheme can't give desired levels of throughput. Better throughput can be achieved if appropriate transmission scheme is used based on the condition of channel. Based on this approach, adaptive packet combining scheme has been proposed to achieve better throughput. The proposed scheme adapts to the channel condition to carry out transmission using PC scheme, APC scheme and SR ARQ scheme to achieve better throughput. Experimentally, it was observed that the error correction capability and throughput of the proposed scheme was significantly better than that of SR ARQ scheme, PC scheme and APC scheme.

A novel function of adenomatous polyposis coli (APC) in regulating DNA repair

PubMed Central

Jaiswal, Aruna S.; Narayan, Satya

2008-01-01

Prevailing literature suggests diversified cellular functions for the adenomatous polyposis coli (APC) gene. Among them a recently discovered unique role of APC is in DNA repair. The APC gene can modulate the base excision repair (BER) pathway through an interaction with DNA polymerase β (Pol-β) and flap endonuclease 1 (Fen-1). Taken together with the transcriptional activation of APC gene by alkylating agents and modulation of BER activity, APC may play an important role in carcinogenesis and chemotherapy by determining whether cells with DNA damage survive or undergo apoptosis. In this review, we summarize the evidence supporting this novel concept and suggest that these results will have implications for the development of more effective strategies for chemoprevention, prognosis, and chemotherapy of certain types of tumors. PMID:18662849

Panta rhei: The APC/C at steady state

PubMed Central

2013-01-01

The anaphase-promoting complex or cyclosome (APC/C) is a conserved, multisubunit E3 ubiquitin (Ub) ligase that is active both in dividing and in postmitotic cells. Its contributions to life are especially well studied in the domain of cell division, in which the APC/C lies at the epicenter of a regulatory network that controls the directionality and timing of cell cycle events. Biochemical and structural work is shedding light on the overall organization of APC/C subunits and on the mechanism of substrate recognition and Ub chain initiation and extension as well as on the molecular mechanisms of a checkpoint that seizes control of APC/C activity during mitosis. Here, we review how these recent advancements are modifying our understanding of the APC/C. PMID:23589490

TRAV7-2*02 Expressing CD8⁺ T Cells Are Responsible for Palladium Allergy.

PubMed

Takeda, Yuri; Suto, Yoshiko; Ito, Koyu; Hashimoto, Wataru; Nishiya, Tadashi; Ueda, Kyosuke; Narushima, Takayuki; Takahashi, Tetsu; Ogasawara, Kouetsu

2017-05-31

While metallic biomaterials have led to an improvement in the quality of life, metal allergies, especially to palladium (Pd), has caused a recent increase in allergic patients. Metal allergy is known to be a T cell-mediated delayed-type hypersensitivity (DTH); however, the pathogenic T cell subsets and the specific T cell receptor (TCR) have not been identified. Therefore, we attempted to identify the pathogenic T cells responsible for Pd allergy. We found that activating CD8⁺ T cells significantly increased and that the TRAV (TCRα variable) 7-2*02 chain skewed in Pd allergic mice. Furthermore, adoptive transfer experiments revealed that in vitro-cultured Pd-stimulated antigen presenting cells (APCs) function as memory APCs with recipient mice developing Pd allergy and that the frequency of TRAV7-2*02 increases the same as conventional Pd allergic mice. In contrast, neither proliferation of CD8⁺ T cells nor increasing of TRAV7-2*02 was observed in major histocompatibility complex I (MHC I)-deficient Pd-APCs transferred to mice. Taken together, we revealed that TRAV7-2*02-expressing CD8⁺ T cells are the pathogenic T cells for the development of Pd allergy. We also identified the CDR3 consensus motif of pathogenic TCRs as CAAXSGSWQLIF in TRAV7-2*02/TRAJ (TCRα junction)22*01 positive cells. These results suggest that the specific TCRs represent novel targets for the development of diagnostics and treatments for metal allergy.

Early planarian brain regeneration is independent of blastema polarity mediated by the Wnt/β-catenin pathway.

PubMed

Iglesias, Marta; Almuedo-Castillo, Maria; Aboobaker, A Aziz; Saló, Emili

2011-10-01

Analysis of anteroposterior (AP) axis specification in regenerating planarian flatworms has shown that Wnt/β-catenin signaling is required for posterior specification and that the FGF-like receptor molecule nou-darake (ndk) may be involved in restricting brain regeneration to anterior regions. The relationship between re-establishment of AP identity and correct morphogenesis of the brain is, however, still poorly understood. Here we report the characterization of two axin paralogs in the planarian Schmidtea mediterranea. Although Axins are well known negative regulators of Wnt/β-catenin signaling, no role in AP specification has previously been reported for axin genes in planarians. We show that silencing of Smed-axin genes by RNA interference (RNAi) results in two-tailed planarians, a phenotype previously reported after silencing of Smed-APC-1, another β-catenin inhibitor. More strikingly, we show for the first time that while early brain formation at anterior wounds remains unaffected, subsequent development of the brain is blocked in the two-tailed planarians generated after silencing of Smed-axin genes and Smed-APC-1. These findings suggest that the mechanisms underlying early brain formation can be uncoupled from the specification of AP identity by the Wnt/β-catenin pathway. Finally, the posterior expansion of the brain observed following Smed-ndk RNAi is enhanced by silencing Smed-APC-1, revealing an indirect relationship between the FGFR/Ndk and Wnt/β-catenin signaling systems in establishing the posterior limits of brain differentiation. Copyright © 2011 Elsevier Inc. All rights reserved.

FBXW7 influences murine intestinal homeostasis and cancer, targeting Notch, Jun, and DEK for degradation

PubMed Central

Babaei-Jadidi, Roya; Li, Ningning; Saadeddin, Anas; Spencer-Dene, Bradley; Jandke, Anett; Muhammad, Belal; Ibrahim, ElSayed E.; Muraleedharan, Ranjithmenon; Abuzinadah, Mohammed; Davis, Hayley; Lewis, Annabelle; Watson, Susan; Behrens, Axel; Tomlinson, Ian

2011-01-01

The Fbxw7 (F-box/WD repeat–containing protein 7; also called CDC4, Sel10, Ago, and Fbw7) component of the SCF (Skp1/Cullin/F-box protein) E3 ubiquitin ligase complex acts as a tumor suppressor in several tissues and targets multiple transcriptional activators and protooncogenes for ubiquitin-mediated degradation. To understand Fbxw7 function in the murine intestine, in this study, we specifically deleted Fbxw7 in the murine gut using Villin-Cre (Fbxw7ΔG). In wild-type mice, loss of Fbxw7 in the gut altered homeostasis of the intestinal epithelium, resulted in elevated Notch and c-Jun expression, and induced development of adenomas at 9–10 mo of age. In the context of APC (adenomatous polyposis coli) deficiency (ApcMin/+ mice), loss of Fbxw7 accelerated intestinal tumorigenesis and death and promoted accumulation of β-catenin in adenomas at late but not early time points. At early time points, Fbxw7 mutant tumors showed accumulation of the DEK protooncogene. DEK expression promoted cell division and altered splicing of tropomyosin (TPM) RNA, which may also influence cell proliferation. DEK accumulation and altered TPM RNA splicing were also detected in FBXW7 mutant human colorectal tumor tissues. Given their reduced lifespan and increased incidence of intestinal tumors, ApcMin/+Fbxw7ΔG mice may be used for testing carcinogenicity and drug screening. PMID:21282377

TRAV7-2*02 Expressing CD8+ T Cells Are Responsible for Palladium Allergy

PubMed Central

Takeda, Yuri; Suto, Yoshiko; Ito, Koyu; Hashimoto, Wataru; Nishiya, Tadashi; Ueda, Kyosuke; Narushima, Takayuki; Takahashi, Tetsu; Ogasawara, Kouetsu

2017-01-01

While metallic biomaterials have led to an improvement in the quality of life, metal allergies, especially to palladium (Pd), has caused a recent increase in allergic patients. Metal allergy is known to be a T cell-mediated delayed-type hypersensitivity (DTH); however, the pathogenic T cell subsets and the specific T cell receptor (TCR) have not been identified. Therefore, we attempted to identify the pathogenic T cells responsible for Pd allergy. We found that activating CD8+ T cells significantly increased and that the TRAV (TCRα variable) 7-2*02 chain skewed in Pd allergic mice. Furthermore, adoptive transfer experiments revealed that in vitro-cultured Pd-stimulated antigen presenting cells (APCs) function as memory APCs with recipient mice developing Pd allergy and that the frequency of TRAV7-2*02 increases the same as conventional Pd allergic mice. In contrast, neither proliferation of CD8+ T cells nor increasing of TRAV7-2*02 was observed in major histocompatibility complex I (MHC I)-deficient Pd-APCs transferred to mice. Taken together, we revealed that TRAV7-2*02-expressing CD8+ T cells are the pathogenic T cells for the development of Pd allergy. We also identified the CDR3 consensus motif of pathogenic TCRs as CAAXSGSWQLIF in TRAV7-2*02/TRAJ (TCRα junction)22*01 positive cells. These results suggest that the specific TCRs represent novel targets for the development of diagnostics and treatments for metal allergy. PMID:28561797

Timely Degradation of Wip1 Phosphatase by APC/C Activator Protein Cdh1 is Necessary for Normal Mitotic Progression.

PubMed

Jeong, Ho-Chang; Gil, Na-Yeon; Lee, Ho-Soo; Cho, Seung-Ju; Kim, Kyungtae; Chun, Kwang-Hoon; Cho, Hyeseong; Cha, Hyuk-Jin

2015-08-01

Wip1 belongs to the protein phosphatase C (PP2C) family, of which expression is up-regulated by a number of external stresses, and serves as a stress modulator in normal physiological conditions. When overexpressed, premature dephosphorylation of stress-mediators by Wip1 results in abrogation of tumor surveillance, thus Wip1 acts as an oncogene. Previously, the functional regulation of Wip1 in cell-cycle progression by counteracting cellular G1 and G2/M checkpoint activity in response to DNA damage was reported. However, other than in stress conditions, the function and regulatory mechanism of Wip1 has not been fully determined. Herein, we demonstrated that protein regulation of Wip1 occurs in a cell cycle-dependent manner, which is directly governed by APC/C(Cdh1) at the end of mitosis. In particular, we also showed evidence that Wip1 phosphatase activity is closely associated with its own protein stability, suggesting that reduced phosphatase activity of Wip1 during mitosis could trigger its degradation. Furthermore, to verify the physiological role of its phosphatase activity during mitosis, we established doxycycline-inducible cell models, including a Wip1 wild type (WT) and phosphatase dead mutant (Wip1 DA). When ectopically expressing Wip1 WT, we observed a delay in the transition from metaphase to anaphase. In conclusion, these studies show that mitotic degradation of Wip1 by APC/C(Cdh1) is important for normal mitotic progression. © 2015 Wiley Periodicals, Inc.

Manufacture of Clinical-Grade CD19-Specific T Cells Stably Expressing Chimeric Antigen Receptor Using Sleeping Beauty System and Artificial Antigen Presenting Cells

PubMed Central

Singh, Harjeet; Figliola, Matthew J.; Dawson, Margaret J.; Olivares, Simon; Zhang, Ling; Yang, Ge; Maiti, Sourindra; Manuri, Pallavi; Senyukov, Vladimir; Jena, Bipulendu; Kebriaei, Partow; Champlin, Richard E.; Huls, Helen; Cooper, Laurence J. N.

2013-01-01

Adoptive transfer of T cells expressing a CD19-specific chimeric antigen receptor (CAR) is being evaluated in multiple clinical trials. Our current approach to adoptive immunotherapy is based on a second generation CAR (designated CD19RCD28) that signals through a CD28 and CD3-ζ endodomain. T cells are electroporated with DNA plasmids from the Sleeping Beauty (SB) transposon/transposase system to express this CAR. Stable integrants of genetically modified T cells can then be retrieved when co-cultured with designer artificial antigen presenting cells (aAPC) in the presence of interleukin (IL)-2 and 21. Here, we reveal how the platform technologies of SB-mediated transposition and CAR-dependent propagation on aAPC were adapted for human application. Indeed, we have initiated clinical trials in patients with high-risk B-lineage malignancies undergoing autologous and allogeneic hematopoietic stem-cell transplantation (HSCT). We describe the process to manufacture clinical grade CD19-specific T cells derived from healthy donors. Three validation runs were completed in compliance with current good manufacturing practice for Phase I/II trials demonstrating that by 28 days of co-culture on γ-irradiated aAPC ∼1010 T cells were produced of which >95% expressed CAR. These genetically modified and propagated T cells met all quality control testing and release criteria in support of infusion. PMID:23741305

Substrate-specific regulation of ubiquitination by the anaphase-promoting complex

PubMed Central

Song, Ling

2011-01-01

By orchestrating the sequential degradation of a large number of cell cycle regulators, the ubiquitin ligase anaphase-promoting complex (APC/C) is essential for proliferation in all eukaryotes. The correct timing of APC/C-dependent substrate degradation, a critical feature of progression through mitosis, was long known to be controlled by mechanisms targeting the core APC/C-machinery. Recent experiments, however have revealed an important contribution of substrate-specific regulation of the APC/C to achieve accurate cell division. In this perspective, we describe different mechanisms of substrate-specific APC/C-regulation and discuss their importance for cell division. PMID:21191176

Analytic Patch Configuration (APC) gateway version 1.0 user's guide

NASA Technical Reports Server (NTRS)

Bingel, Bradford D.

1990-01-01

The Analytic Patch Configuration (APC) is an interactive software tool which translates aircraft configuration geometry files from one format into another. This initial release of the APC Gateway accommodates six formats: the four accepted APC formats (89f, 89fd, 89u, and 89ud), the PATRAN 2.x phase 1 neutral file format, and the Integrated Aerodynamic Analysis System (IAAS) General Geometry (GG) format. Written in ANSI FORTRAN 77 and completely self-contained, the APC Gateway is very portable and was already installed on CDC/NOS, VAX/VMS, SUN, SGI/IRIS, CONVEX, and GRAY hosts.

Effectiveness of extruded rapeseed associated with an alfalfa protein concentrate in enhancing the bovine milk fatty acid composition.

PubMed

Dang Van, Q C; Bejarano, L; Mignolet, E; Coulmier, D; Froidmont, E; Larondelle, Y; Focant, M

2011-08-01

Linseed and rapeseed, good sources of 18:3 n-3 and cis9-18:1, respectively, have been shown to improve the bovine milk fatty acid (FA) profile. However, rapeseed, unlike linseed, has little effect on the concentration of 18:3 n-3 in milk fat. Alfalfa protein concentrate (APC), besides being a valuable protein source for milk production, contains lipids rich in 18:3 n-3. Therefore, this experiment aimed at (1) evaluating the transfer efficiency of unsaturated FA (UFA), especially 18:3 n-3, of APC to bovine milk fat, and (2) evaluating whether extruded rapeseed (ER) associated with APC is as effective as extruded linseed (EL) in enhancing the bovine milk fat composition. Six lactating Holstein cows were used in a replicated 2 × 2 Latin square design with 2 iso-energy, iso-nitrogen and iso-FA corn silage-based diets (EL and ER-APC) and two 21-d periods. Extruded linseed, as main UFA source, was included in the first diet, whereas ER, as main UFA source, and APC, as supplemental 18:3 n-3, were included in the second diet. Diets were distributed as a restricted total mixed ration. Compared with the EL diet, the ER-APC diet, where ER was associated with APC, increased milk concentration of 18:3 n-3 (1.18 vs. 1.31% of FA) and cis9-18:1 (18.35 vs. 20.01% of FA). The apparent transfer efficiency of 18:3 n-3 from diet to milk was almost twice as much for the ER-APC diet than for the EL diet (7.4 vs. 3.8% of intake). Extruded linseed accounted for 84% of 18:3 n-3 provided in the EL diet, whereas ER and APC accounted for 33 and 38% of 18:3 n-3 provided in the ER-APC diet, respectively. Because both EL and ER underwent extrusion in similar conditions, these results suggest that 18:3 n-3 of EL in the EL diet and ER in the ER-APC diet were subjected to more extensive ruminal biohydrogenation than 18:3 n-3 of APC in the ER-APC diet. This experiment shows that corn silage-based diets supplemented with ER as the main UFA source, associated with APC as supplemental 18:3 n-3, are as effective as corn silage-based diets supplemented with EL as the main UFA source, in increasing bovine milk UFA and 18:3 n-3 contents. Furthermore, at similar levels of dietary incorporation, this experiment shows that the ruminal bypass of 18:3 n-3 is higher for APC compared with EL. Copyright © 2011 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

42 CFR 419.45 - Payment and copayment reduction for devices replaced without cost or when full or partial credit...

Code of Federal Regulations, 2010 CFR

2010-10-01

... of reduction to the APC payment. (1) The amount of the reduction to the APC payment made under... be applied if the device implanted during a procedure assigned to the APC had transitional pass-through status under § 419.66. (2) The amount of the reduction to the APC payment made under paragraph (a...

Accelerator mass spectrometry detection of beryllium ions in the antigen processing and presentation pathway

DOE PAGES

Tooker, Brian C.; Brindley, Stephen M.; Chiarappa-Zucca, Marina L.; ...

2014-06-16

We report that exposure to small amounts of beryllium (Be) can result in beryllium sensitization and progression to Chronic Beryllium Disease (CBD). In CBD, beryllium is presented to Be-responsive T-cells by professional antigen-presenting cells (APC). This presentation drives T-cell proliferation and pro-inflammatory cytokine (IL-2, TNFα, and IFNγ) production and leads to granuloma formation. The mechanism by which beryllium enters an APC and is processed to become part of the beryllium antigen complex has not yet been elucidated. Developing techniques for beryllium detection with enough sensitivity has presented a barrier to further investigation. The objective of this study was to demonstratemore » that Accelerator Mass Spectrometry (AMS) is sensitive enough to quantify the amount of beryllium presented by APC to stimulate Be-responsive T-cells. To achieve this goal, APC - which may or may not stimulate Be-responsive T-cells - were cultured with Be-ferritin. Then, by utilizing AMS, the amount of beryllium processed for presentation was determined. Further, IFNγ intracellular cytokine assays were performed to demonstrate that Be-ferritin (at levels used in the experiments) could stimulate Be-responsive T-cells when presented by an APC of the correct HLA type (HLA-DP0201). The results indicated that Be-responsive T-cells expressed IFNγ only when APC with the correct HLA type were able to process Be for presentation. Utilizing AMS, we determined that APC with HLA-DP0201 had membrane fractions containing 0.17-0.59 ng Be and APC with HLA-DP0401 had membrane fractions bearing 0.40-0.45 ng Be. However, HLA-DP0401 APC had 20-times more Be associated with the whole cells (57.68-61.12 ng) then HLA-DP0201 APC (0.90-3.49 ng). As these findings demonstrate, AMS detection of picogram levels of Be processed by APC is possible. Further, regardless of form, Be requires processing by APC to successfully stimulate Be-responsive T-cells to generate IFNγ.« less

Chlorinated Water Modulates the Development of Colorectal Tumors with Chromosomal Instability and Gut Microbiota in Apc-Deficient Mice.

PubMed

Sasada, Tatsunari; Hinoi, Takao; Saito, Yasufumi; Adachi, Tomohiro; Takakura, Yuji; Kawaguchi, Yasuo; Sotomaru, Yusuke; Sentani, Kazuhiro; Oue, Naohide; Yasui, Wataru; Ohdan, Hideki

2015-01-01

The gastrointestinal tract is continuously exposed to a variety of chemicals and commensal bacteria. Recent studies have shown that changes in gut microbial populations caused by chlorine or other chemicals in the drinking water influence the development of human colorectal cancer, although the mechanism of tumorigenesis in the gut epithelium is obfuscated by the diversity of microflora and complexity of the tumor microenvironment. In this regard, mouse models that recapitulate human colorectal cancer are an invaluable tool. In this study, we used two conditional adenomatous polyposis coli (Apc) knockout mouse models to investigate the effect of chlorinated water on tumorigenesis in the digestive tract. Mice with colon-specific carcinoma--caused by either chromosomal (CDX2P 9.5-NLS Cre;Apc(+/flox), abbreviated to CPC;Apc) or microsatellite (CDX2P9.5-G19Cre;Apc(flox/flox) and CDX2P9.5-G22Cre;Apc(flox/flox)) instability, respectively--were administered chlorinated (10.0 mg/L chlorine) or tap (0.7 mg/L chlorine) water and evaluated for colon polyp formation. In CPC;Apc mice given chlorinated drinking water, tumors tended to develop in the colon, whereas in those that drank tap water, tumors were mostly observed in the small intestine. There was no difference in the rate of tumor formation of CDX2P9.5-G19Cre;Apc(flox/flox) and CDX2P9.5-G22Cre;Apc(flox/flox) mice consuming chlorinated as compared to tap water, suggesting that microsatellite instability in the Apc gene does not significantly affect tumorigenesis. Chlorinated water altered the enteric environment by reducing the fecal populations of the obligatory anaerobes Clostridium perfringens and C. difficile, as well as species belonging to the Atopobium cluster, including Enterobacteriaceae and Staphylococcus sp., which was associated with colon tumorigenesis in CPC;Apc mice. These results suggest that differences in tumorigenesis among CPC;Apc mice consuming chlorinated versus tap water may be due to differences in gastrointestinal commensal populations.

Novel APC gene mutations associated with protein alteration in diffuse type gastric cancer.

PubMed

Ghatak, Souvik; Chakraborty, Payel; Sarkar, Sandeep Roy; Chowdhury, Biswajit; Bhaumik, Arup; Kumar, Nachimuthu Senthil

2017-06-02

The role of adenomatous polyposis coli (APC) gene in mitosis might be critical for regulation of genomic stability and chromosome segregation. APC gene mutations have been associated to have a role in colon cancer and since gastric and colon tumors share some common genetic lesions, it is relevant to investigate the role of APC tumor suppressor gene in gastric cancer. We investigated for somatic mutations in the Exons 14 and 15 of APC gene from 40 diffuse type gastric cancersamples. Rabbit polyclonal anti-APC antibody was used, which detects the wild-type APC protein and was recommended for detection of the respective protein in human tissues. Cell cycle analysis was done from tumor and adjacent normal tissue. APC immunoreactivity showed positive expression of the protein in stages I, II, III and negative expression in Stages III and IV. Two novel deleterious variations (g.127576C > A, g.127583C > T) in exon 14 sequence were found to generate stop codon (Y622* and Q625*)in the tumor samples. Due to the generation of stop codon, the APC protein might be truncated and all the regulatory features could be lost which has led to the down-regulation of protein expression. Our results indicate that aneuploidy might occurdue to the codon 622 and 625 APC-driven gastric tumorigenesis, in agreement with our cell cycle analysis. The APC gene function in mitosis and chromosomal stability might be lost and G1 might be arrested with high quantity of DNA in the S phase. Six missense somatic mutations in tumor samples were detected in exon 15 A-B, twoof which showed pathological and disease causing effects based on SIFT, Polyphen2 and SNPs & GO score and were not previously reported in the literature or the public mutation databases. The two novel pathological somatic mutations (g.127576C > A, g.127583C > T) in exon 14 might be altering the protein expression leading to development of gastric cancer in the study population. Our study showed that mutations in the APC gene alter the protein expression and cell cycle regulation in diffuse type gastric adenocarcinoma.

Cationic liposomes promote antigen cross-presentation in dendritic cells by alkalizing the lysosomal pH and limiting the degradation of antigens

PubMed Central

Gao, Jie; Ochyl, Lukasz J; Yang, Ellen; Moon, James J

2017-01-01

Cationic liposomes (CLs) have been widely examined as vaccine delivery nanoparticles since they can form complexes with biomacromolecules, promote delivery of antigens and adjuvant molecules to antigen-presenting cells (APCs), and mediate cellular uptake of vaccine components. CLs are also known to trigger antigen cross-presentation – the process by which APCs internalize extracellular protein antigens, degrade them into minimal CD8+ T-cell epitopes, and present them in the context of major histocompatibility complex-I (MHC-I). However, the precise mechanisms behind CL-mediated induction of cross-presentation and cross-priming of CD8+ T-cells remain to be elucidated. In this study, we have developed two distinct CL systems and examined their impact on the lysosomal pH in dendritic cells (DCs), antigen degradation, and presentation of peptide:MHC-I complexes to antigen-specific CD8+ T-cells. To achieve this, we have used 3β-[N-(N′,N′-dimethylaminoethane)-carbamoyl] cholesterol (DC-Chol) and 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) as the prototypical components of CLs with tertiary amine groups and compared the effect of CLs and anionic liposomes on lysosomal pH, antigen degradation, and cross-presentation by DCs. Our results showed that CLs, but not anionic liposomes, elevated the lysosomal pH in DCs and reduced antigen degradation, thereby promoting cross-presentation and cross-priming of CD8+ T-cell responses. These studies shed new light on CL-mediated cross-presentation and suggest that intracellular fate of vaccine components and subsequent immunological responses can be controlled by rational design of nanomaterials. PMID:28243087

RING E3 mechanism for ubiquitin ligation to a disordered substrate visualized for human anaphase-promoting complex

DOE PAGES

Brown, Nicholas G.; VanderLinden, Ryan; Watson, Edmond R.; ...

2015-03-30

For many E3 ligases, a mobile RING (Really Interesting New Gene) domain stimulates ubiquitin (Ub) transfer from a thioester-linked E2~Ub intermediate to a lysine on a remotely bound disordered substrate. One such E3 is the gigantic, multisubunit 1.2-MDa anaphase-promoting complex/cyclosome (APC), which controls cell division by ubiquitinating cell cycle regulators to drive their timely degradation. Intrinsically disordered substrates are typically recruited via their KEN-box, D-box, and/or other motifs binding to APC and a coactivator such as CDH1. On the opposite side of the APC, the dynamic catalytic core contains the cullin-like subunit APC2 and its RING partner APC11, which collaboratesmore » with the E2 UBCH10 (UBE2C) to ubiquitinate substrates. However, how dynamic RING–E2~Ub catalytic modules such as APC11–UBCH10~Ub collide with distally tethered disordered substrates remains poorly understood. In this paper, we report structural mechanisms of UBCH10 recruitment to APC CDH1 and substrate ubiquitination. Unexpectedly, in addition to binding APC11’s RING, UBCH10 is corecruited via interactions with APC2, which we visualized in a trapped complex representing an APC CDH1–UBCH10~Ub–substrate intermediate by cryo-electron microscopy, and in isolation by X-ray crystallography. To our knowledge, this is the first structural view of APC, or any cullin–RING E3, with E2 and substrate juxtaposed, and it reveals how tripartite cullin–RING–E2 interactions establish APC’s specificity for UBCH10 and harness a flexible catalytic module to drive ubiquitination of lysines within an accessible zone. Finally, we propose that multisite interactions reduce the degrees of freedom available to dynamic RING E3–E2~Ub catalytic modules, condense the search radius for target lysines, increase the chance of active-site collision with conformationally fluctuating substrates, and enable regulation.« less

Interaction between APC and Fen1 during breast carcinogenesis

PubMed Central

Narayan, Satya; Jaiswal, Aruna S.; Law, Brian K.; Mohammed, Kamal A.; Sharma, Arun K.; Hromas, Robert A.

2016-01-01

Aberrant DNA base excision repair (BER) contributes to malignant transformation. However, inter-individual variations in DNA repair capacity plays a key role in modifying breast cancer risk. We review here emerging evidence that two proteins involved in BER – adenomatous polyposis coli (APC) and flap endonuclease 1 (Fen1) – promote the development of breast cancer through novel mechanisms. APC and Fen1 expression and interaction is increased in breast tumors versus normal cells, APC interacts with and blocks Fen1 activity in Pol-β-directed LP-BER, and abrogation of LP-BER is linked with cigarette smoke condensate-induced transformation of normal breast epithelial cells. Carcinogens increase expression of APC and Fen1 in spontaneously immortalized human breast epithelial cells, human colon cancer cells, and mouse embryonic fibroblasts. Since APC and Fen1 are tumor suppressors, an increase in their levels could protect against carcinogenesis; however, this does not seem to be the case. Elevated Fen1 levels in breast and lung cancer cells may reflect the enhanced proliferation of cancer cells or increased DNA damage in cancer cells compared to normal cells. Inactivation of the tumor suppressor functions of APC and Fen1 is due to their interaction, which may act as a susceptibility factor for breast cancer. The increased interaction of APC and Fen1 may occur due to polypmorphic and/or mutational variation in these genes. Screening of APC and Fen1 polymorphic and/or mutational variations and APC/Fen1 interaction may permit assessment of individual DNA repair capability and the risk for breast cancer development. Such individuals might lower their breast cancer risk by reducing exposure to carcinogens. Stratifying individuals according to susceptibility would greatly assist epidemiologic studies of the impact of suspected environmental carcinogens. Additionally, a mechanistic understanding of the interaction of APC and Fen1 may provide the basis for developing new and effective targeted chemopreventive and chemotherapeutic agents. PMID:27088617

Germline Missense Changes in the APC Gene and Their Relationship to Disease.

PubMed

Scott, Rodney J; Crooks, Renee; Rose, Lindy; Attia, John; Thakkinstian, Ammarin; Thomas, Lesley; Spigelman, Allan D; Meldrum, Cliff J

2004-05-15

Familial adenomatous polyposis (FAP) is characterized by the presence of hundreds to thousands of adenomas that carpet the entire colon and rectum. Nonsense and frameshift mutations in the adenomatous polyposis coli (APC) gene account for the majority of mutations identified to date and predispose primarily to the typical disease phenotype. Some APC mutations are associated with a milder form of the disease known as attenuated FAP. Virtually all mutations that have been described in the APC gene result in the formation of a premature stop codon and very little is known about missense mutations apart from a common Ashkenazi Jewish mutation (1307 K) and a British E1317Q missense change. The incidence of missense mutations in the APC gene has been underreported since the APC gene lends itself to analysis using an artificial transcription and translation assay known as the Protein Truncation Test (PTT) or the In Vitro Synthetic Protein assay (IVSP).In this report we have used denaturing high performance liquid chromatography to analyse the entire coding sequence of the APC gene to determine if a cohort of patients adhering to the diagnostic criteria of FAP to assess the frequency of missense mutations in the APC gene. Altogether 112 patients were studied and 22 missense mutations were identified. From the total of 22 missense changes, 13 were silent changes and the remaining 9 resulted in amino acid substitutions. One or more of these changes were identified multiple times in 62.5% of the population under study.The results reveal that missense mutations in the APC gene appear not to radically alter protein function but may be associated with more subtle processing of RNA transcripts which in turn could result in the expression of differentially spliced forms of the APC gene which may interfere with the functional activity of the APC protein.

Interaction between APC and Fen1 during breast carcinogenesis.

PubMed

Narayan, Satya; Jaiswal, Aruna S; Law, Brian K; Kamal, Mohammad A; Sharma, Arun K; Hromas, Robert A

2016-05-01

Aberrant DNA base excision repair (BER) contributes to malignant transformation. However, inter-individual variations in DNA repair capacity plays a key role in modifying breast cancer risk. We review here emerging evidence that two proteins involved in BER - adenomatous polyposis coli (APC) and flap endonuclease 1 (Fen1) - promote the development of breast cancer through novel mechanisms. APC and Fen1 expression and interaction is increased in breast tumors versus normal cells, APC interacts with and blocks Fen1 activity in Pol-β-directed LP-BER, and abrogation of LP-BER is linked with cigarette smoke condensate-induced transformation of normal breast epithelial cells. Carcinogens increase expression of APC and Fen1 in spontaneously immortalized human breast epithelial cells, human colon cancer cells, and mouse embryonic fibroblasts. Since APC and Fen1 are tumor suppressors, an increase in their levels could protect against carcinogenesis; however, this does not seem to be the case. Elevated Fen1 levels in breast and lung cancer cells may reflect the enhanced proliferation of cancer cells or increased DNA damage in cancer cells compared to normal cells. Inactivation of the tumor suppressor functions of APC and Fen1 is due to their interaction, which may act as a susceptibility factor for breast cancer. The increased interaction of APC and Fen1 may occur due to polypmorphic and/or mutational variation in these genes. Screening of APC and Fen1 polymorphic and/or mutational variations and APC/Fen1 interaction may permit assessment of individual DNA repair capability and the risk for breast cancer development. Such individuals might lower their breast cancer risk by reducing exposure to carcinogens. Stratifying individuals according to susceptibility would greatly assist epidemiologic studies of the impact of suspected environmental carcinogens. Additionally, a mechanistic understanding of the interaction of APC and Fen1 may provide the basis for developing new and effective targeted chemopreventive and chemotherapeutic agents. Published by Elsevier B.V.

The role of APC in WNT pathway activation in serrated neoplasia.

PubMed

Borowsky, Jennifer; Dumenil, Troy; Bettington, Mark; Pearson, Sally-Ann; Bond, Catherine; Fennell, Lochlan; Liu, Cheng; McKeone, Diane; Rosty, Christophe; Brown, Ian; Walker, Neal; Leggett, Barbara; Whitehall, Vicki

2018-03-01

Conventional adenomas are initiated by APC gene mutation that activates the WNT signal. Serrated neoplasia is commonly initiated by BRAF or KRAS mutation. WNT pathway activation may also occur, however, to what extent this is owing to APC mutation is unknown. We examined aberrant nuclear β-catenin immunolocalization as a surrogate for WNT pathway activation and analyzed the entire APC gene coding sequence in serrated and conventional pathway polyps and cancers. WNT pathway activation was a common event in conventional pathway lesions with aberrant nuclear immunolocalization of β-catenin and truncating APC mutations in 90% and 89% of conventional adenomas and 82% and 70% of BRAF wild-type cancers, respectively. WNT pathway activation was seen to a lesser extent in serrated pathway lesions. It occurred at the transition to dysplasia in serrated polyps with a significant increase in nuclear β-catenin labeling from sessile serrated adenomas (10%) to sessile serrated adenomas with dysplasia (55%) and traditional serrated adenomas (9%) to traditional serrated adenomas with dysplasia (39%) (P=0.0001). However, unlike the conventional pathway, truncating APC mutations were rare in the serrated pathway lesions especially sessile serrated adenomas even when dysplastic (15%) and in the BRAF mutant cancers with microsatellite instability that arise from them (8%). In contrast, APC missense mutations that were rare in conventional pathway adenomas and cancers (3% in BRAF wild-type cancers) were more frequent in BRAF mutant cancers with microsatellite instability (32%). We conclude that increased WNT signaling is important in the transition to malignancy in the serrated pathway but that APC mutation is less common and the spectrum of mutations is different than in conventional colorectal carcinogenesis. Moderate impact APC mutations and non-APC-related causes of increased WNT signaling may have a more important role in serrated neoplasia than the truncating APC mutations common in conventional adenomas.

Quantitative framework for ordered degradation of APC/C substrates.

PubMed

Lu, Dan; Girard, Juliet R; Li, Weihan; Mizrak, Arda; Morgan, David O

2015-11-16

During cell-cycle progression, substrates of a single master regulatory enzyme can be modified in a specific order. Here, we used experimental and computational approaches to dissect the quantitative mechanisms underlying the ordered degradation of the substrates of the ubiquitin ligase APC/C(Cdc20), a key regulator of chromosome segregation in mitosis. We show experimentally that the rate of catalysis varies with different substrates of APC/C(Cdc20). Using a computational model based on multi-step ubiquitination, we then show how changes in the interaction between a single substrate and APC/C(Cdc20) can alter the timing of degradation onset relative to APC/C(Cdc20) activation, while ensuring a fast degradation rate. Degradation timing and dynamics depend on substrate affinity for the enzyme as well as the catalytic rate at which the substrate is modified. When two substrates share the same pool of APC/C(Cdc20), their relative enzyme affinities and rates of catalysis influence the partitioning of APC/C(Cdc20) among substrates, resulting in substrate competition. Depending on how APC/C(Cdc20) is partitioned among its substrates, competition can have minor or major effects on the degradation of certain substrates. We show experimentally that increased expression of the early APC/C(Cdc20) substrate Clb5 does not delay the degradation of the later substrate securin, arguing against a role for competition with Clb5 in establishing securin degradation timing. The degradation timing of APC/C(Cdc20) substrates depends on the multi-step nature of ubiquitination, differences in substrate-APC/C(Cdc20) interactions, and competition among substrates. Our studies provide a conceptual framework for understanding how ordered modification can be established among substrates of the same regulatory enzyme, and facilitate our understanding of how precise temporal control is achieved by a small number of master regulators to ensure a successful cell division cycle.

Analysing the impact of nucleo-cytoplasmic shuttling of β-catenin and its antagonists APC, Axin and GSK3 on Wnt/β-catenin signalling.

PubMed

Schmitz, Yvonne; Rateitschak, Katja; Wolkenhauer, Olaf

2013-11-01

The canonical Wnt signalling pathway plays a critical role in development and disease. The key player of the pathway is β-catenin. Its activity is mainly regulated by the destruction complex consisting of APC, Axin and GSK3. In the nucleus, the complex formation of β-catenin and TCF initiates target gene expression. Our study provides a comprehensive analysis of the role of nucleo-cytoplasmic shuttling of APC, Axin, and GSK3 and the inactivation of β-catenin by the destruction complex in Wnt/β-catenin signalling. We address the following questions: Can nucleo-cytoplasmic shuttling of APC, Axin and GSK3 increase the [β-catenin/TCF] concentration? And, how is the [β-catenin/TCF] concentration influenced by phosphorylation and subsequent degradation of nuclear β-catenin? Based on experimental findings, we develop a compartmental model and conduct several simulation experiments. Our analysis reveals the following key findings: 1) nucleo-cytoplasmic shuttling of β-catenin and its antagonists can yield a spatial separation between the said proteins, which results in a breakdown of β-catenin degradation, followed by an accumulation of β-catenin and hence leads to an increase of the [β-catenin/TCF] concentration. Our results strongly suggest that Wnt signalling can benefit from nucleo-cytoplasmic shuttling of APC, Axin and GSK3, although they are in general β-catenin antagonising proteins. 2) The total robustness of the [β-catenin/TCF] output is closely linked to its absolute concentration levels. We demonstrate that the compartmental separation of β-catenin and the destruction complex does not only lead to a maximization, but additionally to an increased robustness of [β-catenin/TCF] signalling against perturbations in the cellular environment. 3) A nuclear accumulation of the destruction complex renders the pathway robust against fluctuations in Wnt signalling and against changes in the compartmental distribution of β-catenin. 4) Elucidating the impact of destruction complex inhibition, we show that the [β-catenin/TCF] concentration is more effectively enhanced by inhibition of the kinase GSK3 rather than the binding of β-catenin to the destruction complex. © 2013 Elsevier Inc. All rights reserved.

Different sensitivities of cultured mammalian cells towards aphidicolin-enhanced DNA effects in the comet assay.

PubMed

Speit, Günter; Schütz, Petra; Bausinger, Julia

2016-06-01

The comet assay in combination with the polymerase inhibitor aphidicolin (APC) has been used to measure DNA excision repair activity, DNA repair kinetics and individual DNA repair capacity. Since APC can enhance genotoxic effects of mutagens measured by the comet assay, this approach has been proposed for increasing the sensitivity of the comet assay in human biomonitoring. The APC-modified comet assay has mainly been performed with human blood and it was shown that it not only enhances the detection of DNA damage repaired by nucleotide excision repair (NER) but also damage typically repaired by base excision repair (BER). Recently, we reported that in contrast to blood leukocytes, A549 cells (a human lung adenocarcinoma cell line) seem to be insensitive towards the repair-inhibiting action of APC. To further elucidate the general usefulness of the APC-modified comet assay for studying repair in cultured mammalian cells, we comparatively investigated further cell lines (HeLa, TK6, V79). DNA damage was induced by BPDE (benzo[a]pyrene-7,8-dihydrodiol-9,10-epoxide) and MMS (methyl methanesulfonate) in the absence and presence of APC (3 or 15μM). APC was either added for 2h together with the mutagen or cells were pre-incubated for 30min with APC before the mutagen was added. The results indicate that the cell lines tested differ fundamentally with regard to their sensitivity and specificity towards the repair-inhibiting effect of APC. The actual cause for these differences is still unclear but potential molecular explanations are discussed. Irrespective of the underlying mechanism(s), our study revealed practical limitations of the use of the APC-modified comet assay. Copyright © 2016 Elsevier B.V. All rights reserved.

Kaiso overexpression promotes intestinal inflammation and potentiates intestinal tumorigenesis in Apc(Min/+) mice.

PubMed

Pierre, Christina C; Longo, Joseph; Mavor, Meaghan; Milosavljevic, Snezana B; Chaudhary, Roopali; Gilbreath, Ebony; Yates, Clayton; Daniel, Juliet M

2015-09-01

Constitutive Wnt/β-catenin signaling is a key contributor to colorectal cancer (CRC). Although inactivation of the tumor suppressor adenomatous polyposis coli (APC) is recognized as an early event in CRC development, it is the accumulation of multiple subsequent oncogenic insults facilitates malignant transformation. One potential contributor to colorectal carcinogenesis is the POZ-ZF transcription factor Kaiso, whose depletion extends lifespan and delays polyp onset in the widely used Apc(Min/+) mouse model of intestinal cancer. These findings suggested that Kaiso potentiates intestinal tumorigenesis, but this was paradoxical as Kaiso was previously implicated as a negative regulator of Wnt/β-catenin signaling. To resolve Kaiso's role in intestinal tumorigenesis and canonical Wnt signaling, we generated a transgenic mouse model (Kaiso(Tg/+)) expressing an intestinal-specific myc-tagged Kaiso transgene. We then mated Kaiso(Tg/+) and Apc(Min/+) mice to generate Kaiso(Tg/+):Apc(Min/+) mice for further characterization. Kaiso(Tg/+):Apc(Min/+) mice exhibited reduced lifespan and increased polyp multiplicity compared to Apc(Min/+) mice. Consistent with this murine phenotype, we found increased Kaiso expression in human CRC tissue, supporting a role for Kaiso in human CRC. Interestingly, Wnt target gene expression was increased in Kaiso(Tg/+):Apc(Min/+) mice, suggesting that Kaiso's function as a negative regulator of canonical Wnt signaling, as seen in Xenopus, is not maintained in this context. Notably, Kaiso(Tg/+):Apc(Min/+) mice exhibited increased inflammation and activation of NFκB signaling compared to their Apc(Min/+) counterparts. This phenotype was consistent with our previous report that Kaiso(Tg/+) mice exhibit chronic intestinal inflammation. Together our findings highlight a role for Kaiso in promoting Wnt signaling, inflammation and tumorigenesis in the mammalian intestine. Copyright © 2015 Elsevier B.V. All rights reserved.

ETS-Associated Genomic Alterations including ETS2 Loss Markedly Affect Prostate Cancer Progression

DTIC Science & Technology

2015-10-01

upregulation of ERG, a transcription factor with oncogenic roles in other cancers such as leukemias and sarcomas (Tomlins, Rhodes et al. 2005; Turner ...represses Apc(Min)-mediated tumours in mouse models of Down’s syndrome ." Nature 451(7174): 73-75. Taylor, B. S., N. Schultz, et al. (2010...generation antiandrogen for treatment of advanced prostate cancer." Science 324(5928): 787-790. Turner , D. P. and D. K. Watson (2008). "ETS transcription

Intestinal flora of FAP patients containing APC-like sequences.

PubMed

Hainova, K; Adamcikova, Z; Ciernikova, S; Stevurkova, V; Tyciakova, S; Zajac, V

2014-01-01

Colorectal cancer mortality is one of the most common cause of cancer-related mortality. A multiple risk factors are associated with colorectal cancer, including hereditary, enviromental and inflammatory syndromes affecting the gastrointestinal tract. Familial adenomatous polyposis (FAP) is characterized by the emergence of hundreds to thousands of colorectal adenomatous polyps and FAP syndrome is caused by mutations within the adenomatous polyposis coli (APC) tumor suppressor gene. We analyzed 21 rectal bacterial subclones isolated from FAP patient 41-1 with confirmed 5bp ACAAA deletion within codons 1060-1063 for the presence of APC-like sequences in longest exon 15. The studied section was defined by primers 15Efor-15Erev, what correlates with mutation cluster region (MCR) in which the 75% of all APC germline mutations were detected. More than 90% homology was showed by sequencing and subsequent software comparison. The expression of APC-like sequences was demostrated by Western blot analysis using monoclonal and polyclonal antibodies against APC protein. To study missing link between the DNA analysis (PCR, DNA sequencing) and protein expresion experiments (Western blotting) we analyzed bacterial transcripts containing the 15Efor-15Erev sequence of APC gene by reverse transcription-PCR, what indicated that an APC gene derived fragment may be produced. We observed 97-100 % homology after computer comparison of cDNA PCR products. Our results suggest that presence of APC-like sequences in intestinal/rectal bacteria is enrichment of bacterial genetic information in which horizontal gene transfer between humans and microflora play an important role.

The efficacy of activated protein C in murine endotoxemia is dependent on integrin CD11b

PubMed Central

Cao, Chunzhang; Gao, Yamei; Li, Yang; Antalis, Toni M.; Castellino, Francis J.; Zhang, Li

2010-01-01

Activated protein C (APC), the only FDA-approved biotherapeutic drug for sepsis, possesses anticoagulant, antiinflammatory, and barrier-protective activities. However, the mechanisms underlying its anti­inflammatory functions are not well defined. Here, we report that the antiinflammatory activity of APC on macrophages is dependent on integrin CD11b/CD18, but not on endothelial protein C receptor (EPCR). We showed that CD11b/CD18 bound APC within specialized membrane microdomains/lipid rafts and facilitated APC cleavage and activation of protease-activated receptor–1 (PAR1), leading to enhanced production of sphingosine-1-phosphate (S1P) and suppression of the proinflammatory response of activated macrophages. Deletion of the γ-carboxyglutamic acid domain of APC, a region critical for its anticoagulant activity and EPCR-dependent barrier protection, had no effect on its antiinflammatory function. Genetic inactivation of CD11b, PAR1, or sphingosine kinase–1, but not EPCR, abolished the ability of APC to suppress the macrophage inflammatory response in vitro. Using an LPS-induced mouse model of lethal endotoxemia, we showed that APC administration reduced the mortality of wild-type mice, but not CD11b-deficient mice. These data establish what we believe to be a novel mechanism underlying the antiinflammatory activity of APC in the setting of endotoxemia and provide clear evidence that the antiinflammatory function of APC is distinct from its barrier-protective function and anticoagulant activities. PMID:20458145

Epithelial-derived IL-33 promotes intestinal tumorigenesis in Apc Min/+ mice.

PubMed

He, Zhengxiang; Chen, Lili; Souto, Fabricio O; Canasto-Chibuque, Claudia; Bongers, Gerold; Deshpande, Madhura; Harpaz, Noam; Ko, Huaibin M; Kelley, Kevin; Furtado, Glaucia C; Lira, Sergio A

2017-07-14

Increased expression of Interleukin (IL)-33 has been detected in intestinal samples of patients with ulcerative colitis, a condition associated with increased risk for colon cancer, but its role in the development of colorectal cancer has yet to be fully examined. Here, we investigated the role of epithelial expressed IL-33 during development of intestinal tumors. IL-33 expression was detected in epithelial cells in colorectal cancer specimens and in the Apc Min/+ mice. To better understand the role of epithelial-derived IL-33 in the intestinal tumorigenesis, we generated transgenic mice expressing IL-33 in intestinal epithelial cells (V33 mice). V33 Apc Min/+ mice, resulting from the cross of V33 with Apc Min/+ mice, had increased intestinal tumor burden compared with littermate Apc Min/+ mice. Consistently, Apc Min/+ mice deficient for IL-33 receptor (ST2), had reduced polyp burden. Mechanistically, overexpression of IL-33 promoted expansion of ST2 + regulatory T cells, increased Th2 cytokine milieu, and induced alternatively activated macrophages in the gut. IL-33 promoted marked changes in the expression of antimicrobial peptides, and antibiotic treatment of V33 Apc Min/+ mice abrogated the tumor promoting-effects of IL-33 in the colon. In conclusion, elevated IL-33 signaling increases tumor development in the Apc Min/+ mice.

Suppression of intestinal tumorigenesis in Apc mutant mice upon Musashi-1 deletion.

PubMed

Wolfe, Andy R; Ernlund, Amanda; McGuinness, William; Lehmann, Carl; Carl, Kaitlyn; Balmaceda, Nicole; Neufeld, Kristi L

2017-02-15

Therapeutic strategies based on a specific oncogenic target are better justified when elimination of that particular oncogene reduces tumorigenesis in a model organism. One such oncogene, Musashi-1 ( Msi-1 ), regulates translation of target mRNAs and is implicated in promoting tumorigenesis in the colon and other tissues. Msi-1 targets include the tumor suppressor adenomatous polyposis coli ( Apc ), a Wnt pathway antagonist lost in ∼80% of all colorectal cancers. Cell culture experiments have established that Msi-1 is a Wnt target, thus positioning Msi-1 and Apc as mutual antagonists in a mutually repressive feedback loop. Here, we report that intestines from mice lacking Msi-1 display aberrant Apc and Msi-1 mutually repressive feedback, reduced Wnt and Notch signaling, decreased proliferation, and changes in stem cell populations, features predicted to suppress tumorigenesis. Indeed, mice with germline Apc mutations ( Apc Min ) or with the Apc 1322T truncation mutation have a dramatic reduction in intestinal polyp number when Msi-1 is deleted. Taken together, these results provide genetic evidence that Msi-1 contributes to intestinal tumorigenesis driven by Apc loss, and validate the pursuit of Msi-1 inhibitors as chemo-prevention agents to reduce tumor burden. © 2017. Published by The Company of Biologists Ltd.

Nanoengineering approaches to the design of artificial antigen-presenting cells

PubMed Central

Sunshine, Joel C; Green, Jordan J

2014-01-01

Artificial antigen-presenting cells (aAPCs) have shown great initial promise for ex vivo activation of cytotoxic T cells. The development of aAPCs has focused mainly on the choice of proteins to use for surface presentation to T cells when conjugated to various spherical, microscale particles. We review here biomimetic nanoengineering approaches that have been applied to the development of aAPCs that move beyond initial concepts about aAPC development. This article also discusses key technologies that may be enabling for the development of nano- and micro-scale aAPCs with nanoscale features, and suggests several future directions for the field. PMID:23837856

Changes in antigen-presenting cell function in the spleen and lymph nodes of ultraviolet-irradiated mice

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

Gurish, M.F.; Lynch, D.H.; Daynes, R.A.

1982-03-01

It has been previously reported that mice exposed to ultraviolet (UV) radiation exhibit a decrease in splenic antigen-presenting cell (APC) function. The results presented here confirm this observation and further demonstrate that animals exposed daily to UV for extended periods of time (5 weeks instead of 6 days) no longer exhibit this depressed capability. In spite of the depression in splenic APC activity found in 6-day UV-irradiated mice, lymph node APC function from these same animals was elevated compared with that found in the lymph nodes from normal animals. Lymph node APC activity in animals that were splenectomized prior tomore » the UV irradiation, however, was not enhanced over controls. Treatment of animals with a chemical irritant (turpentine) also caused a depression in splenic APC function without modifying lymph node activity. Collectively, our findings suggest that the observed decrease in splenic APC activity, found after the first week of UV exposures, may be attributable to the migration of splenic APC to peripheral lymphoid tissue which drain the site of epidermal inflammation.« less

Oral Administration of Apple Procyanidins Ameliorates Insulin Resistance via Suppression of Pro-Inflammatory Cytokine Expression in Liver of Diabetic ob/ob Mice.

PubMed

Ogura, Kasane; Ogura, Masahito; Shoji, Toshihiko; Sato, Yuichi; Tahara, Yumiko; Yamano, Gen; Sato, Hiroki; Sugizaki, Kazu; Fujita, Naotaka; Tatsuoka, Hisato; Usui, Ryota; Mukai, Eri; Fujimoto, Shimpei; Inagaki, Nobuya; Nagashima, Kazuaki

2016-11-23

Procyanidins, the main ingredient of apple polyphenols, are known to possess antioxidative and anti-inflammatory effects associated closely with the pathophysiology of insulin resistance and type 2 diabetes. We investigated the effects of orally administered apple procyanidins (APCs) on glucose metabolism using diabetic ob/ob mice. We found no difference in body weight or body composition between mice treated with APCs and untreated mice. A 4 week oral administration of APCs containing water [0.5% (w/v)] ameliorated glucose tolerance, insulin resistance, and hepatic gluconeogenesis in ob/ob mice. APCs also suppressed the increase in the level of the pancreatic β-cell. Insulin-stimulated Akt phosphorylation was significantly enhanced; pro-inflammatory cytokine expression levels were significantly decreased, and c-Jun N-terminal kinase phosphorylation was downregulated in the liver of those mice treated with APCs. In conclusion, APCs ameliorate insulin resistance by improving hepatic insulin signaling through suppression of hepatic inflammation in ob/ob mice, which may be a mechanism with possible beneficial health effects of APCs in disturbed glucose metabolism.

The APC/C Coordinates Retinal Differentiation with G1 Arrest through the Nek2-Dependent Modulation of Wingless Signaling.

PubMed

Martins, Torcato; Meghini, Francesco; Florio, Francesca; Kimata, Yuu

2017-01-09

The cell cycle is coordinated with differentiation during animal development. Here we report a cell-cycle-independent developmental role for a master cell-cycle regulator, the anaphase-promoting complex or cyclosome (APC/C), in the regulation of cell fate through modulation of Wingless (Wg) signaling. The APC/C controls both cell-cycle progression and postmitotic processes through ubiquitin-dependent proteolysis. Through an RNAi screen in the developing Drosophila eye, we found that partial APC/C inactivation severely inhibits retinal differentiation independently of cell-cycle defects. The differentiation inhibition coincides with hyperactivation of Wg signaling caused by the accumulation of a Wg modulator, Drosophila Nek2 (dNek2). The APC/C degrades dNek2 upon synchronous G1 arrest prior to differentiation, which allows retinal differentiation through local suppression of Wg signaling. We also provide evidence that decapentaplegic signaling may posttranslationally regulate this APC/C function. Thus, the APC/C coordinates cell-fate determination with the cell cycle through the modulation of developmental signaling pathways. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

Critical Current Properties in Longitudinal Magnetic Field of YBCO Superconductor with APC

NASA Astrophysics Data System (ADS)

Kido, R.; Kiuchi, M.; Otabe, E. S.; Matsushita, T.; Jha, A. K.; Matsumoto, K.

The critical current density (Jc) properties of the Artificial Pinning Center (APC) introduced YBa2Cu3O7 (YBCO) films in the longitudinal magnetic field were measured. Y2O3 or Y2BaCuO5 (Y211) was introduced as APCs to YBCO, and YBCO films with APC were fabricated on SrTiO3 single crystal substrate. The sizes of Y2O3 and Y211 were 5-10 nm and 10-20 nm, respectively. As a result, Jc enhancement in the longitudinal magnetic field was observed in Y2O3 introduced YBCO films. However, it was not observed in Y211 introduced YBCO films. Therefore, it was considered that Jc properties in the longitudinal magnetic field were affected by introducing of small size APC, and it was necessary that APC does not disturb the current pathway in the superconductor.

Methylation status of the APC and RASSF1A promoter in cell-free circulating DNA and its prognostic role in patients with colorectal cancer.

PubMed

Matthaios, Dimitrios; Balgkouranidou, Ioanna; Karayiannakis, Anastasios; Bolanaki, Helen; Xenidis, Nikolaos; Amarantidis, Kyriakos; Chelis, Leonidas; Romanidis, Konstantinos; Chatzaki, Aikaterini; Lianidou, Evi; Trypsianis, Grigorios; Kakolyris, Stylianos

2016-07-01

DNA methylation is the most frequent epigenetic alteration. Using methylation-specific polymerase chain reaction (MSP), the methylation status of the adenomatous polyposis coli ( APC ) and Ras association domain family 1 isoform A ( RASSF1A ) genes was examined in cell-free circulating DNA from 155 plasma samples obtained from patients with early and advanced colorectal cancer (CRC). APC and RASSF1A hypermethylation was frequently observed in both early and advanced disease, and was significantly associated with a poorer disease outcome. The methylation status of the APC and RASSF1A promoters was investigated in cell-free DNA of patients with CRC. Using MSP, the promoter methylation status of APC and RASSF1A was examined in 155 blood samples obtained from patients with CRC, 88 of whom had operable CRC (oCRC) and 67 had metastatic CRC (mCRC). The frequency of APC methylation in patients with oCRC was 33%. Methylated APC promoter was significantly associated with older age (P=0.012), higher stage (P=0.014) and methylated RASSF1A status (P=0.050). The frequency of APC methylation in patients with mCRC was 53.7%. In these patients, APC methylation was significantly associated with methylated RASSF1A status (P=0.016). The frequency of RASSF1A methylation in patients with oCRC was 25%. Methylated RASSF1A in oCRC was significantly associated with higher stage (P=0.021). The frequency of RASSF1A methylation in mCRC was 44.8%. Methylated RASSF1A in mCRC was associated with moderate differentiation (P=0.012), high levels of carcinoembryonic antigen (P=0.023) and methylated APC status (P=0.016). Patients with an unmethylated APC gene had better survival in both early (81±5 vs. 27±4 months, P<0.001) and advanced disease (37±7 vs. 15±3 months, P<0.001), compared with patients with methylated APC . Patients with an unmethylated RASSF1A gene had better survival in both early (71±6 vs. 46±8 months, P<0.001) and advanced disease (28±4 vs. 16±3 months, P<0.001) than patients with methylated RASSF1A . The observed significant correlations between APC and RASSF1A promoter methylation status and survival may be indicative of a prognostic role for these genes in CRC, which requires additional testing in larger studies.

Synergistic Blockade of Mitotic Exit by Two Chemical Inhibitors of the APC/C

PubMed Central

Sackton, Katharine L.; Dimova, Nevena; Zeng, Xing; Tian, Wei; Zhang, Mengmeng; Sackton, Timothy B.; Meaders, Johnathan; Pfaff, Kathleen L.; Sigoillot, Frederic; Yu, Hongtao; Luo, Xuelian; King, Randall W.

2014-01-01

Summary Protein machines are multi-subunit protein complexes that orchestrate highly regulated biochemical tasks. An example is the Anaphase-Promoting Complex/Cyclosome (APC/C), a thirteen-subunit ubiquitin ligase that initiates the metaphase-anaphase transition and mitotic exit by targeting proteins such as securin and cyclin B1 for ubiquitin-dependent destruction by the proteasome1,2. Because blocking mitotic exit is an effective approach for inducing tumor cell death3,4, the APC/C represents a potential novel target for cancer therapy. APC/C activation in mitosis requires binding of Cdc205, which forms a co-receptor with the APC/C to recognize substrates containing a Destruction box (D-box)6-14. Here we demonstrate that we can synergistically inhibit APC/C-dependent proteolysis and mitotic exit by simultaneously disrupting two protein-protein interactions within the APC/C-Cdc20-substrate ternary complex. We identified a small molecule, called apcin (APC inhibitor), which binds to Cdc20 and competitively inhibits the ubiquitylation of D-box-containing substrates. Analysis of the crystal structure of the apcin-Cdc20 complex suggests that apcin occupies the D-box-binding pocket on the side face of the WD40-domain. The ability of apcin to block mitotic exit is synergistically amplified by co-addition of tosyl-L-arginine methyl ester (TAME), a small molecule that blocks the APC/C-Cdc20 interaction15,16. This work suggests that simultaneous disruption of multiple, weak protein-protein interactions is an effective approach for inactivating a protein machine. PMID:25156254

Data sharing system for lithography APC

NASA Astrophysics Data System (ADS)

Kawamura, Eiichi; Teranishi, Yoshiharu; Shimabara, Masanori

2007-03-01

We have developed a simple and cost-effective data sharing system between fabs for lithography advanced process control (APC). Lithography APC requires process flow, inter-layer information, history information, mask information and so on. So, inter-APC data sharing system has become necessary when lots are to be processed in multiple fabs (usually two fabs). The development cost and maintenance cost also have to be taken into account. The system handles minimum information necessary to make trend prediction for the lots. Three types of data have to be shared for precise trend prediction. First one is device information of the lots, e.g., process flow of the device and inter-layer information. Second one is mask information from mask suppliers, e.g., pattern characteristics and pattern widths. Last one is history data of the lots. Device information is electronic file and easy to handle. The electronic file is common between APCs and uploaded into the database. As for mask information sharing, mask information described in common format is obtained via Wide Area Network (WAN) from mask-vender will be stored in the mask-information data server. This information is periodically transferred to one specific lithography-APC server and compiled into the database. This lithography-APC server periodically delivers the mask-information to every other lithography-APC server. Process-history data sharing system mainly consists of function of delivering process-history data. In shipping production lots to another fab, the product-related process-history data is delivered by the lithography-APC server from the shipping site. We have confirmed the function and effectiveness of data sharing systems.

A role for cyclin-dependent kinase(s) in the modulation of fast anterograde axonal transport: effects defined by olomoucine and the APC tumor suppressor protein

NASA Technical Reports Server (NTRS)

Ratner, N.; Bloom, G. S.; Brady, S. T.

1998-01-01

Proteins that interact with both cytoskeletal and membrane components are candidates to modulate membrane trafficking. The tumor suppressor proteins neurofibromin (NF1) and adenomatous polyposis coli (APC) both bind to microtubules and interact with membrane-associated proteins. The effects of recombinant NF1 and APC fragments on vesicle motility were evaluated by measuring fast axonal transport along microtubules in axoplasm from squid giant axons. APC4 (amino acids 1034-2844) reduced only anterograde movements, whereas APC2 (aa 1034-2130) or APC3 (aa 2130-2844) reduced both anterograde and retrograde transport. NF1 had no effect on organelle movement in either direction. Because APC contains multiple cyclin-dependent kinase (CDK) consensus phosphorylation motifs, the kinase inhibitor olomoucine was examined. At concentrations in which olomoucine is specific for cyclin-dependent kinases (5 microM), it reduced only anterograde transport, whereas anterograde and retrograde movement were both affected at concentrations at which other kinases are inhibited as well (50 microM). Both anterograde and retrograde transport also were inhibited by histone H1 and KSPXK peptides, substrates for proline-directed kinases, including CDKs. Our data suggest that CDK-like axonal kinases modulate fast anterograde transport and that other axonal kinases may be involved in modulating retrograde transport. The specific effect of APC4 on anterograde transport suggests a model in which the binding of APC to microtubules may limit the activity of axonal CDK kinase or kinases in restricted domains, thereby affecting organelle transport.

Evaluation of a Computerized Decision Support Intervention to Decrease Use of Anti-Pseudomonal Carbapenems in Penicillin Allergic Patients

PubMed Central

Caplinger, Christina; Smith, Garret; Remington, Richard; Madaras-Kelly, Karl

2016-01-01

Allergies to β-lactam antibiotics are commonly documented in hospitalized patients; however, true allergy is uncommon. Cross-reactivity rates for advanced generation cephalosporins and carbapenems are low; particularly for patients without a history of symptoms consistent with type 1 hypersensitivity. We observed that providers preferentially prescribed antipseudomonal carbapenems (APC) over advanced generation cephalosporins for patients with β-lactam allergy history, including those with low risk for antimicrobial-resistant infections. Information was inserted into the computerized decision support system (CDSS) to aid clinicians in assessing β-lactam cross-reactivity risk and selecting appropriate therapy. A retrospective evaluation was conducted in a small hospital to assess the impact of the CDSS changes in APC prescribing. Inpatients (n = 68) who received at least one APC dose during hospitalization over a 13 month pre-intervention period were compared to inpatients who received an APC during the 15 month post-intervention period (n = 59) for documented APC indications and β-lactam allergy history. APC initiations were measured and corrected per 1000 patient-days; interrupted time-series analysis was performed to assess changes in use before and after implementation. Aggregate monthly APC initiations decreased from 7.01 to 6.14 per 1000 patient-days after the implementation (p = 0.03). Post-intervention APC initiations for patients with low-risk β-lactam histories decreased from 92% to 83% (p = 0.17). No adverse events were observed in patients with low-risk β-lactam histories. The intervention was associated with a reduction in APC initiations. PMID:27025522

NUP98 fusion oncoproteins interact with the APC/C(Cdc20) as a pseudosubstrate and prevent mitotic checkpoint complex binding.

PubMed

Salsi, Valentina; Fantini, Sebastian; Zappavigna, Vincenzo

2016-09-01

NUP98 is a recurrent partner gene in translocations causing acute myeloid leukemias and myelodisplastic syndrome. The expression of NUP98 fusion oncoproteins has been shown to induce mitotic spindle defects and chromosome missegregation, which correlate with the capability of NUP98 fusions to cause mitotic checkpoint attenuation. We show that NUP98 oncoproteins physically interact with the APC/C(Cdc20) in the absence of the NUP98 partner protein RAE1, and prevent the binding of the mitotic checkpoint complex to the APC/C(Cdc20). NUP98 oncoproteins require the GLEBS-like domain present in their NUP98 moiety to bind the APC/C(Cdc20). We found that NUP98 wild-type is a substrate of APC/C(Cdc20) prior to mitotic entry, and that its binding to APC/C(Cdc20) is controlled via phosphorylation of a PEST sequence located within its C-terminal portion. We identify S606, within the PEST sequence, as a key target site, whose phosphorylation modulates the capability of NUP98 to interact with APC/C(Cdc20). We finally provide evidence for an involvement of the peptidyl-prolyl isomerase PIN1 in modulating the possible conformational changes within NUP98 that lead to its dissociation from the APC/C(Cdc20) during mitosis. Our results provide novel insight into the mechanisms underlying the aberrant capability of NUP98 oncoproteins to interact with APC/C(Cdc20) and to interfere with its function.

Tissue-Specific Control of the Endocycle by the Anaphase Promoting Complex/Cyclosome Inhibitors UVI4 and DEL1.

PubMed

Heyman, Jefri; Polyn, Stefanie; Eekhout, Thomas; De Veylder, Lieven

2017-09-01

The endocycle represents a modified mitotic cell cycle that in plants is often coupled to cell enlargement and differentiation. Endocycle onset is controlled by activity of the Anaphase Promoting Complex/Cyclosome (APC/C), a multisubunit E3 ubiquitin ligase targeting cell-cycle factors for destruction. CELL CYCLE SWITCH52 (CCS52) proteins represent rate-limiting activator subunits of the APC/C. In Arabidopsis ( Arabidopsis thaliana ), mutations in either CCS52A1 or CCS52A2 activators result in a delayed endocycle onset, whereas their overexpression triggers increased DNA ploidy levels. Here, the relative contribution of the APC/C CCS52A1 and APC/C CCS52A2 complexes to different developmental processes was studied through analysis of their negative regulators, being the ULTRAVIOLET-B-INSENSITIVE4 protein and the DP-E2F-Like1 transcriptional repressor, respectively. Our data illustrate cooperative activity of the APC/C CCS52A1 and APC/C CCS52A2 complexes during root and trichome development, but functional interdependency during leaf development. Furthermore, we found APC/C CCS52A1 activity to control CCS52A2 expression. We conclude that interdependency of CCS52A-controlled APC/C activity is controlled in a tissue-specific manner. © 2017 American Society of Plant Biologists. All Rights Reserved.

APC/C--the master controller of origin licensing?

PubMed

Sivaprasad, Umasundari; Machida, Yuichi J; Dutta, Anindya

2007-02-23

DNA replication must be tightly controlled to prevent initiation of a second round of replication until mitosis is complete. So far, components of the pre-replicative complex (Cdt1, Cdc6 and geminin) were considered key players in this regulation. In a new study, Machida and Dutta have shown that depletion of Emi1 caused cells to replicate their DNA more than once per cell cycle 1. This effect was dependent on the ability of Emi1 to inhibit the APC/C. In addition to its role in regulating entry into mitosis, oscillation of APC/C activity regulates pre-RC formation: high APC/C activity in late M/G1 allows pre-RC formation and low APC/C activity in S/G2 prevents pre-RC formation for a second time thereby preventing rereplication. Each redundant pathway to prevent rereplication is dependent on regulating one of the pre-RC components, and all of the pathways are co-regulated by Emi1 through the APC/C. In this commentary we discuss how this new role of Emi1 adds to our understanding of the regulation of replication initiation. We also review the literature to analyze whether APC/C has a role in regulating endoreduplication (a normal state of polyploidy in some differentiated cells). Similarly a role of premature APC/C activation in genomic instability of tumors is discussed.

Regulation of nuclear envelope dynamics via APC/C is necessary for the progression of semi-open mitosis in Schizosaccharomyces japonicus.

PubMed

Aoki, Keita; Shiwa, Yuh; Takada, Hiraku; Yoshikawa, Hirofumi; Niki, Hironori

2013-09-01

Three types of mitosis, which are open, closed or semi-open mitosis, function in eukaryotic cells, respectively. The open mitosis involves breakage of the nuclear envelope before nuclear division, whereas the closed mitosis proceeds with an intact nuclear envelope. To understand the mechanism and significance of three types of mitotic division in eukaryotes, we investigated the process of semi-open mitosis, in which the nuclear envelope is only partially broken, in the fission yeast Schizosaccharomyces japonicus. In anaphase-promoting complex/cyclosome (APC/C) mutants of Sz. japonicus, the nuclear envelope remained relatively intact during anaphase, resulting in impaired semi-open mitosis. As a suppressor of apc2 mutant, a mutation of Oar2, which was a 3-oxoacyl-[acyl carrier protein] reductase, was obtained. The level of the Oar2, which had two destruction-box motifs recognized by APC/C, was increased in APC/C mutants. Furthermore, the defective semi-open mitosis observed in an apc2 mutant was restored by mutated oar2+. Based on these findings, we propose that APC/C regulates the dynamics of the nuclear envelope through degradation of Oar2 dependent on APC/C during the metaphase-to-anaphase transition of semi-open mitosis in Sz. japonicus. © 2013 The Authors Genes to Cells © 2013 by the Molecular Biology Society of Japan and Wiley Publishing Asia Pty Ltd.

Cutting Edge: Processing of Oxidized Peptides in Macrophages Regulates T Cell Activation and Development of Autoimmune Arthritis.

PubMed

Yang, Min; Haase, Claus; Viljanen, Johan; Xu, Bingze; Ge, Changrong; Kihlberg, Jan; Holmdahl, Rikard

2017-12-15

APCs are known to produce NADPH oxidase (NOX) 2 - derived reactive oxygen species; however, whether and how NOX2-mediated oxidation affects redox-sensitive immunogenic peptides remains elusive. In this study, we investigated a major immunogenic peptide in glucose-6-phosphate isomerase (G6PI), a potential autoantigen in rheumatoid arthritis, which can form internal disulfide bonds. Ag presentation assays showed that presentation of this G6PI peptide was more efficient in NOX2-deficient ( Ncf1 m1J/m1J mutant) mice, compared with wild-type controls. IFN-γ - inducible lysosomal thiol reductase (GILT), which facilitates disulfide bond-containing Ag processing, was found to be upregulated in macrophages from Ncf1 mutant mice. Ncf1 mutant mice exhibited more severe G6PI peptide-induced arthritis, which was accompanied by the increased GILT expression in macrophages and enhanced Ag-specific T cell responses. Our results show that NOX2-dependent processing of the redox-sensitive autoantigens by APCs modify T cell activity and development of autoimmune arthritis. Copyright © 2017 by The American Association of Immunologists, Inc.

PKCθ links proximal T cell and Notch signaling through localized regulation of the actin cytoskeleton

PubMed Central

Britton, Graham J; Ambler, Rachel; Clark, Danielle J; Hill, Elaine V; Tunbridge, Helen M; McNally, Kerrie E; Burton, Bronwen R; Butterweck, Philomena; Sabatos-Peyton, Catherine; Hampton-O’Neil, Lea A; Verkade, Paul; Wülfing, Christoph; Wraith, David Cameron

2017-01-01

Notch is a critical regulator of T cell differentiation and is activated through proteolytic cleavage in response to ligand engagement. Using murine myelin-reactive CD4 T cells, we demonstrate that proximal T cell signaling modulates Notch activation by a spatiotemporally constrained mechanism. The protein kinase PKCθ is a critical mediator of signaling by the T cell antigen receptor and the principal costimulatory receptor CD28. PKCθ selectively inactivates the negative regulator of F-actin generation, Coronin 1A, at the center of the T cell interface with the antigen presenting cell (APC). This allows for effective generation of the large actin-based lamellum required for recruitment of the Notch-processing membrane metalloproteinase ADAM10. Such enhancement of Notch activation is critical for efficient T cell proliferation and Th17 differentiation. We reveal a novel mechanism that, through modulation of the cytoskeleton, controls Notch activation at the T cell:APC interface thereby linking T cell receptor and Notch signaling pathways. DOI: http://dx.doi.org/10.7554/eLife.20003.001 PMID:28112644

TAK1 (MAP3K7) inhibition promotes apoptosis in KRAS-dependent colon cancers

PubMed Central

Singh, Anurag; Sweeney, Michael F.; Yu, Min; Burger, Alexa; Greninger, Patricia; Benes, Cyril; Haber, Daniel A.; Settleman, Jeff

2012-01-01

Summary Colon cancers frequently harbor KRAS mutations, yet only a subset of KRAS-mutant colon cancer cell lines are dependent upon KRAS signaling for survival. In a screen for kinases that promote survival of KRAS-dependent colon cancer cells, we found that the TAK1 kinase (MAP3K7) is required for tumor cell viability. The induction of apoptosis by RNAi-mediated depletion or pharmacologic inhibition of TAK1 is linked to its suppression of hyperactivated Wnt signaling, evident in both endogenous and genetically reconstituted cells. In APC-mutant/KRAS-dependent cells, KRAS stimulates BMP-7 secretion and BMP signaling, leading to TAK1 activation and enhancement of Wnt-dependent transcription. An in vitro-derived “TAK1-dependency signature” is enriched in primary human colon cancers with mutations in both APC and KRAS, suggesting potential clinical utility in stratifying patient populations. Together, these findings identify TAK1 inhibition as a potential therapeutic strategy for a treatment-refractory subset of colon cancers exhibiting aberrant KRAS and Wnt pathway activation. PMID:22341439

T cell ignorance is bliss: T cells are not tolerized by Langerhans cells presenting human papillomavirus antigens in the absence of costimulation.

PubMed

Woodham, Andrew W; Yan, Lisa; Skeate, Joseph G; van der Veen, Daniel; Brand, Heike H; Wong, Michael K; Da Silva, Diane M; Kast, W Martin

2016-12-01

Human papillomavirus type 16 (HPV16) infections are intra-epithelial, and thus, HPV16 is known to interact with Langerhans cells (LCs), the resident epithelial antigen-presenting cells (APCs). The current paradigm for APC-mediated induction of T cell anergy is through delivery of T cell receptor signals via peptides on MHC molecules (signal 1), but without costimulation (signal 2). We previously demonstrated that LCs exposed to HPV16 in vitro present HPV antigens to T cells without costimulation, but it remained uncertain if such T cells would remain ignorant, become anergic, or in the case of CD4+ T cells, differentiate into Tregs. Here we demonstrate that Tregs were not induced by LCs presenting only signal 1, and through a series of in vitro immunizations show that CD8 + T cells receiving signal 1 + 2 from LCs weeks after consistently receiving signal 1 are capable of robust effector functions. Importantly, this indicates that T cells are not tolerized but instead remain ignorant to HPV, and are activated given the proper signals.

Generation of B-cell chronic lymphocytic leukemia (B-CLL)-reactive T-cell lines and clones from HLA class I-matched donors using modified B-CLL cells as stimulators: implications for adoptive immunotherapy.

PubMed

Hoogendoorn, M; Wolbers, J Olde; Smit, W M; Schaafsma, M R; Barge, R M Y; Willemze, R; Falkenburg, J H F

2004-07-01

Allogeneic stem cell transplantation following reduced-intensity conditioning is being evaluated in patients with advanced B-cell chronic lymphocytic leukemia (B-CLL). The curative potential of this procedure is mediated by donor-derived alloreactive T cells, resulting in a graft-versus-leukemia effect. However, B-CLL may escape T-cell-mediated immune reactivity since these cells lack expression of costimulatory molecules. We examined the most optimal method to transform B-CLL cells into efficient antigen-presenting cells (APC) using activating cytokines, by triggering toll-like receptors (TLRs) using microbial pathogens and by CD40 stimulation with CD40L-transfected fibroblasts. CD40 activation in the presence of IL-4 induced strongest upregulation of costimulatory and adhesion molecules on B-CLL cells and induced the production of high amounts of IL-12 by the leukemic cells. In contrast to primary B-CLL cells as stimulator cells, these malignant APCs were capable of inducing the generation of B-CLL-reactive CD8(+) CTL lines and clones from HLA class I-matched donors. These CTL lines and clones recognized and killed primary B-CLL as well as patient-derived lymphoblasts, but not donor cells. These results show the feasibility of ex vivo generation of B-CLL-reactive CD8(+) CTLs. This opens new perspectives for adoptive immunotherapy, following allogeneic stem cell transplantation in patients with advanced B-CLL.

Hypermethylated APC in serous carcinoma based on a meta-analysis of ovarian cancer.

PubMed

Shen, Chunyan; Sheng, Qifang; Zhang, Xiaojie; Fu, Yuling; Zhu, Kemiao

2016-09-26

The reduced expression of the Adenomatous polyposis coli (APC) gene, a tumor suppressor gene, through promoter hypermethylation has been reported to play a key role in the carcinogenesis. However, the correlation between APC promoter hypermethylation and ovarian cancer (OC) remains to be clarified. A comprehensive literature search was carried out in related research databases. The overall odds ratio (OR) and corresponding 95 % confidence interval (CI) were used to evaluate the effects of APC promoter hypermethylation on OC and clinicopathological characteristics. Ultimately, 12 eligible studies were used in our study, including 806 OC samples, 429 normal controls, 109 benign lesions and 75 LMP samples. The pooled OR showed that APC promoter hypermethylation was significantly higher in OC than in normal and benign controls (OR = 6.18 and OR = 3.26, respectively). No significant correlation was observed between OC and low malignant potential (LMP) tumors (P = 0.436). In the comparison of OC and normal controls, subgroup analysis based on race showed that the overall OR of APC promoter hypermethylation was significant and similar in Asians and Caucasians (OR = 8.34 and OR = 5.39, respectively). A subgroup analysis based on sample type found that the pooled OR was significantly higher in blood than in tissue (OR = 18.71 and OR = 5.74, respectively). A significant association was not observed between APC promoter hypermethylation and tumor grade or tumor stage. The pooled OR indicated that APC promoter hypermethylation was significantly lower in serous carcinoma than in non-serous carcinoma (OR = 0.56, P = 0.02). No obvious publication bias was detected by Egger's test (all P > 0.05). APC promoter hypermethylation may be linked to the increased risk of OC. It was associated with histological type, but not with tumor grade or tumor stage. Moreover, hypermethylated APC may be a noninvasive biomarker using blood samples. Future studies are required to validate these results.

Relationship Between Endothelial Wall Shear Stress and High-Risk Atherosclerotic Plaque Characteristics for Identification of Coronary Lesions That Cause Ischemia: A Direct Comparison With Fractional Flow Reserve.

PubMed

Han, Donghee; Starikov, Anna; Ó Hartaigh, Bríain; Gransar, Heidi; Kolli, Kranthi K; Lee, Ji Hyun; Rizvi, Asim; Baskaran, Lohendran; Schulman-Marcus, Joshua; Lin, Fay Y; Min, James K

2016-12-19

Wall shear stress (WSS) is an established predictor of coronary atherosclerosis progression. Prior studies have reported that high WSS has been associated with high-risk atherosclerotic plaque characteristics (APCs). WSS and APCs are quantifiable by coronary computed tomography angiography, but the relationship of coronary lesion ischemia-evaluated by fractional flow reserve-to WSS and APCs has not been examined. WSS measures were obtained from 100 evaluable patients who underwent coronary computed tomography angiography and invasive coronary angiography with fractional flow reserve. Patients were categorized according to tertiles of mean WSS values defined as low, intermediate, and high. Coronary ischemia was defined as fractional flow reserve ≤0.80. Stenosis severity was determined by minimal luminal diameter. APCs were defined as positive remodeling, low attenuation plaque, and spotty calcification. The likelihood of having positive remodeling and low-attenuation plaque was greater in the high WSS group compared with the low WSS group after adjusting for minimal luminal diameter (odds ratio for positive remodeling: 2.54, 95% CI 1.12-5.77; odds ratio for low-attenuation plaque: 2.68, 95% CI 1.02-7.06; both P<0.05). No significant relationship was observed between WSS and fractional flow reserve when adjusting for either minimal luminal diameter or APCs. WSS displayed no incremental benefit above stenosis severity and APCs for detecting lesions that caused ischemia (area under the curve for stenosis and APCs: 0.87, 95% CI 0.81-0.93; area under the curve for stenosis, APCs, and WSS: 0.88, 95% CI 0.82-0.93; P=0.30 for difference). High WSS is associated with APCs independent of stenosis severity. WSS provided no added value beyond stenosis severity and APCs for detecting lesions with significant ischemia. © 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Identification a nonsense mutation of APC gene in Chinese patients with familial adenomatous polyposis.

PubMed

Li, Haishan; Zhang, Lingling; Jiang, Quan; Shi, Zhenwang; Tong, Hanxing

2017-04-01

Familial adenomatous polyposis (FAP; Mendelian of Inherintance in Man ID, 175100) is a rare autosomal dominant disorder characterized by the development of numerous adenomatous polyps throughout the colon and rectum associated with an increased risk of colorectal cancer. FAP is at time accompanied with certain extraintestinal manifestations such as congenital hypertrophy of the retinal pigment epithelium, dental disorders and desmoid tumors. It is caused by mutations in the adenomatous polyposis coli ( APC ) gene. The present study reported on a Chinese family with FAP. Polymerase chain reaction and direct sequencing of the full coding sequence of the APC gene were performed to identify the mutation in this family. A nonsense mutation of the APC gene was identified in this pedigree. It is a heterozygous G>T substitution at position 2,971 in exon 15 of the APC gene, which formed a premature stop codon at amino acid residue 991 (p.Glu991*). The resulting truncated protein lacked 1,853 amino acids. The present study expanded the database on APC gene mutations in FAP and enriched the spectrum of known germline mutations of the APC gene. Prophylactic proctocolectomy may be considered as a possible treatment for carriers of the mutation.

Quantitative assessment of the association between APC promoter methylation and breast cancer.

PubMed

He, Keli; Zhang, Li; Long, Xinghua

2016-06-21

Adenomatous polyposis coli (APC) is an important tumor suppressor gene in breast cancer. However, there were inconsistent conclusions in the association between APC promoter methylation and breast cancer. Hence, we conducted a meta-analysis to quantitatively assess the clinicopathological significance and diagnosis role of APC methylation in breast cancer. In total, 3172 samples from 29 studies were performed in this study. The odds ratio (OR) of APC methylation was 5.92 (95% CI = 3.16-11.07) in breast cancer cases compared to controls,. The APC promoter methylation was associated with cancer stage (OR = 0.47, 95% CI = 0.28-0.80, P = 0.006), lymph node metastases (OR = 0.55, 95% CI = 0.36-0.84, P = 0.005) and ER status (OR = 1.34, 95% CI = 1.03-1.73, P = 0.003) in breast cancer. Furthermore, the sensitivity and specificity for all included studies were 0.444 (95% CI: 0.321-0.575, P < 0.0001) and 0.976 (95% CI: 0.916-0.993, P < 0.0001), respectively. These results suggested that APC promoter methylation was associated with breast cancer risk, and it could be a valuable biomarker for diagnosis, treatment and prognosis of breast cancer.

A System Approach to Advanced Practice Clinician Standardization and High Reliability.

PubMed

Okuno-Jones, Susan; Siehoff, Alice; Law, Jennifer; Juarez, Patricia

Advanced practice clinicians (APCs) are an integral part of the health care team. Opportunities exist within Advocate Health Care to standardize and optimize APC practice across the system. To enhance the role and talents of APCs, an approach to role definition and optimization of practice and a structured approach to orientation and evaluation are shared. Although in the early stages of development, definition and standardization of accountabilities in a framework to support system changes are transforming the practice of APCs.

Evaluation and analysis of Seasat-A scanning multichannel Microwave Radiometer (SMMR) Antenna Pattern Correction (APC) algorithm

NASA Technical Reports Server (NTRS)

Kitzis, J. L.; Kitzis, S. N.

1979-01-01

The brightness temperature data produced by the SMMR final Antenna Pattern Correction (APC) algorithm is discussed. The algorithm consisted of: (1) a direct comparison of the outputs of the final and interim APC algorithms; and (2) an analysis of a possible relationship between observed cross track gradients in the interim brightness temperatures and the asymmetry in the antenna temperature data. Results indicate a bias between the brightness temperature produced by the final and interim APC algorithm.

Studies of Several New Modifications of Aggressive Packet Combining to Achieve Higher Throughput, Based on Correction Capability of Disjoint Error Vectors

NASA Astrophysics Data System (ADS)

Chakraborty, Swarnendu Kumar; Goswami, Rajat Subhra; Bhunia, Chandan Tilak; Bhunia, Abhinandan

2016-06-01

Aggressive packet combining (APC) scheme is well-established in literature. Several modifications were studied earlier for improving throughput. In this paper, three new modifications of APC are proposed. The performance of proposed modified APC is studied by simulation and is reported here. A hybrid scheme is proposed here for getting higher throughput and also the disjoint factor is compared among conventional APC with proposed schemes for getting higher throughput.

Multi-scale modeling of APC and [Formula: see text]-catenin regulation in the human colonic crypt.

PubMed

Emerick, Brooks; Schleiniger, Gilberto; Boman, Bruce M

2018-06-01

Stem cell renewal and differentiation in the human colonic crypt are linked to the [Formula: see text]-catenin pathway. The spatial balance of Wnt factors in proliferative cells within the crypt maintain an appropriate level of cellular reproduction needed for normal crypt homeostasis. Mutational events at the gene level are responsible for deregulating the balance of Wnt factors along the crypt, causing an overpopulation of proliferative cells, a loss of structure of the crypt domain, and the initiation of colorectal carcinomas. We formulate a PDE model describing cell movement and reproduction in a static crypt domain. We consider a single cell population whose proliferative capabilities are determined by stemness, a quantity defined by intracellular levels of adenomatous polyposis coli (APC) scaffold protein and [Formula: see text]-catenin. We fit APC regulation parameters to biological data that describe normal protein gradients in the crypt. We also fit cell movement and protein flux parameters to normal crypt characteristics such as renewal time, total cell count, and proportion of proliferating cells. The model is used to investigate abnormal crypt dynamics when subjected to a diminished APC gradient, a scenario synonymous to mutations in the APC gene. We find that a 25% decrease in APC synthesis leads to a fraction of 0.88 proliferative, which is reflective of normal-appearing FAP crypts. A 50% drop in APC activity yields a fully proliferative crypt showing a doubling of the level of stemness, which characterizes the initial stages of colorectal cancer development. A sensitivity analysis of APC regulation parameters shows the perturbation of factors that is required to restore crypt dynamics to normal in the case of APC mutations.

[Divergent Trends in Suicide Mortality in Navarra and Spain: 2000-2015].

PubMed

Delfrade, Josu; Sayón-Orea, Carmen; Teijeira-Álvarez, Rafael; Floristán-Floristán, Yugo; Moreno-Iribas, Conchi

2017-05-03

The aim of this study was to know the suicide mortality rates in Navarra and Spain and to compare their time trends during the period 2000-2015. Suicide data were obtained from the Instituto Nacional de Estadística [INE], Spain’s National Statistics Institute. During all the period, the coding of cause of death in Navarra was carried out using data from forensic autopsies, while in some Spanish regions this process started after 2010. A Joinpoint time series regression model was used to assess the time trend and estimate the annual percent change [APC] of the rates by sex and 4 age groups. Suicide mortality in Spain showed a significant downward trend in the overall rate between 2000-2011 [APC of -1.93% in males and -2.19% in females] followed by a significant increase in 2012-2015 [APC: 3.65% in men and 7.60% in women]. No inflection points were observed in men aged 25-44 [APC:1.26%], 45-64 [APC: 1.63%], and women over 65 years [APC:-2.18%]. In Navarra, global rates in men showed a non significant decrease [APC:-1.56%] and a significant decrease in the group of men between 25-44 years [APC:-3.19%]. Among women we observed a non significant increase [APC: 0.74%]. The rise in overall suicide rates observed in Spain since 2011, that was not observed in Navarre, could be influenced by the improvements in coding methods in several Spanish regions. However, this could not explain the decrease observed during the all period in men aged 25-44, that was even larger in Navarra.

Increase of Alternatively Activated Antigen Presenting Cells in Active Experimental Autoimmune Encephalomyelitis.

PubMed

Wasser, Beatrice; Pramanik, Gautam; Hess, Moritz; Klein, Matthias; Luessi, Felix; Dornmair, Klaus; Bopp, Tobias; Zipp, Frauke; Witsch, Esther

2016-12-01

The importance of CD11c + antigen-presenting cells (APCs) in the pathogenesis of experimental autoimmune encephalomyelitis (EAE) is well accepted and the gate keeper function of perivascular CD11c + APCs has been demonstrated. CD11c can be expressed by APCs from external sources or by central nervous system (CNS) resident APCs such as microglia. Yet, changes in the gene expression pattern of CNS CD11c + APCs during disease are still unclear and differentially expressed genes might play a decisive role in EAE progression. Due to their low numbers in the diseased brain and due to the absence of considerable numbers in the healthy CNS, analysis of CNS CD11c + cells is technically difficult. To ask whether the CD11c + APC population contributes to remission of EAE disease, we used Illumina deep mRNA sequencing (RNA-Seq) and quantitative real time polymerase chain reaction (qRT-PCR) analyses to identify the transcriptome of CD11c + APCs during disease course. We identified a battery of genes that were significantly regulated during the exacerbation of the disease compared to remission and relapse. Three of these genes, Arginase-1, Chi3l3 and Ms4a8a, showed a higher expression at the exacerbation than at later time points during the disease, both in SJL/J and in C57BL/6 mice, and could be attributed to alternatively activated APCs. Expression of Arginase-1, Chi3l3 and Ms4a8a genes was linked to the disease phase of EAE rather than to disease score. Expression of these genes suggested that APCs resembling alternatively activated macrophages are involved during the first wave of neuroinflammation and can be directly associated with the disease progress.

Proteomic profiling of a mouse model of acute intestinal Apc deletion leads to identification of potential novel biomarkers of human colorectal cancer (CRC).

PubMed

Hammoudi, Abeer; Song, Fei; Reed, Karen R; Jenkins, Rosalind E; Meniel, Valerie S; Watson, Alastair J M; Pritchard, D Mark; Clarke, Alan R; Jenkins, John R

2013-10-25

Colorectal cancer (CRC) is the fourth most common cause of cancer-related death worldwide. Accurate non-invasive screening for CRC would greatly enhance a population's health. Adenomatous polyposis coli (Apc) gene mutations commonly occur in human colorectal adenomas and carcinomas, leading to Wnt signalling pathway activation. Acute conditional transgenic deletion of Apc in murine intestinal epithelium (AhCre(+)Apc(fl)(/)(fl)) causes phenotypic changes similar to those found during colorectal tumourigenesis. This study comprised a proteomic analysis of murine small intestinal epithelial cells following acute Apc deletion to identify proteins that show altered expression during human colorectal carcinogenesis, thus identifying proteins that may prove clinically useful as blood/serum biomarkers of colorectal neoplasia. Eighty-one proteins showed significantly increased expression following iTRAQ analysis, and validation of nine of these by Ingenuity Pathaway Analysis showed they could be detected in blood or serum. Expression was assessed in AhCre(+)Apc(fl)(/)(fl) small intestinal epithelium by immunohistochemistry, western blot and quantitative real-time PCR; increased nucelolin concentrations were also detected in the serum of AhCre(+)Apc(fl)(/)(fl) and Apc(Min)(/)(+) mice by ELISA. Six proteins; heat shock 60kDa protein 1, Nucleolin, Prohibitin, Cytokeratin 18, Ribosomal protein L6 and DEAD (Asp-Glu-Ala-Asp) box polypeptide 5,were selected for further investigation. Increased expression of 4 of these was confirmed in human CRC by qPCR. In conclusion, several novel candidate biomarkers have been identified from analysis of transgenic mice in which the Apc gene was deleted in the intestinal epithelium that also showed increased expression in human CRC. Some of these warrant further investigation as potential serum-based biomarkers of human CRC. Copyright © 2013 Elsevier Inc. All rights reserved.

APC fly ashes stabilized with Portland cement for further development of road sub-base aggregates

NASA Astrophysics Data System (ADS)

Formosa, J.; Giro-Paloma, J.; Maldonado-Alameda, A.; Huete-Hernández, S.; Chimenos, J. M.

2017-10-01

Although waste-to-energy plants allow reducing the mass and volume of municipal solid waste (MSW) incinerated, an average around 30 % of the total content remains as bottom ash (BA) and air pollution control (APC) ashes at the end of combustion process. While weathered bottom ash (WBA) is considered a non-hazardous residue that can be revalorized as a secondary aggregate, APC fly ashes generated during the flue gas treatment are classified as hazardous waste and are handled in landfill disposal after stabilization, usually with Portland cement (OPC). However, taking into account the amount of APC residues produced and the disposing cost in landfill, their revalorization is an important issue that could be effectively addressed. As MSW can be incinerated producing bottom ashes (BA) or air pollutant control (APC) residues, the development of a mortar formulated with APC fly ash as secondary building material is a significant risk to the environment for their content of heavy metals. In this way, Design of Experiment (DoE) was used for the improvement of granular material (GM) formulation composed by APC and OPC for further uses as road sub-base aggregate. DoE analysis was successful in the modelling and optimization the formulation as function of the mechanical properties and APC amount. Consequently, an optimal mortar formulation (OMF) of around 50 wt.% APC and 50 wt.% OPC was considered. The OMF leachates and abrasion resistance have been analyzed. These results have demonstrated the viability of OMF as non-hazardous material feasible to be used as secondary aggregate. Moreover, it would be possible to consider the environmental assessment of a GM composed by ≈20 wt.% of OMF and ≈80 wt.% of WBA in order to improve mechanical properties and heavy metals stabilization.

The PP2AB56 phosphatase promotes the association of Cdc20 with APC/C in mitosis.

PubMed

Lee, Sun Joo; Rodriguez-Bravo, Veronica; Kim, Hyunjung; Datta, Sutirtha; Foley, Emily A

2017-05-15

PP2A comprising B56 regulatory subunit isoforms (PP2A B56 ) is a serine/threonine phosphatase essential for mitosis. At the kinetochore, PP2A B56 both stabilizes microtubule binding and promotes silencing of the spindle assembly checkpoint (SAC) through its association with the SAC protein BubR1. Cells depleted of the B56 regulatory subunits of PP2A are delayed in activation of Cdc20-containing APC/C (APC/C Cdc20 ), which is an essential step for mitotic exit. It has been hypothesized that this delay arises from increased production of the mitotic checkpoint complex (MCC), an APC/C Cdc20 inhibitor formed at unattached kinetochores through SAC signaling. In contrast to this prediction, we show that depletion of B56 subunits does not increase the amount or stability of the MCC. Rather, delays in APC/C Cdc20 activation in B56-depleted cells correlate with impaired Cdc20 binding to APC/C. Stimulation of APC/C Cdc20 assembly does not require binding between PP2A B56 and BubR1, and thus this contribution of PP2A B56 towards mitotic exit is distinct from its functions at kinetochores. PP2A B56 associates with APC/C constitutively in a BubR1-independent manner. A mitotic phosphorylation site on Cdc20, known to be a substrate of PP2A B56 , modulates APC/C Cdc20 assembly. These results elucidate the contributions of PP2A B56 towards completion of mitosis. © 2017. Published by The Company of Biologists Ltd.

Esophageal Cancer Clinical Presentation: Trends in the Last 3 Decades in a Large Italian Series.

PubMed

Cavallin, Francesco; Scarpa, Marco; Cagol, Matteo; Alfieri, Rita; Ruol, Alberto; Sileni, Vanna Chiarion; Ancona, Ermanno; Castoro, Carlo

2018-01-01

The aim of this study was to investigate trends in patients' characteristics and comorbidities in esophageal cancer (EC) patients. Identifying changing pattern is essential to understand and predict further changes and to plan surgical procedures and resource allocation. Trends in patients' characteristics and comorbidities were evaluated in 4440 EC patients at the Center for Esophageal Diseases in Padova, Italy, during 1980 to 2011. Joinpoint regression analysis was performed to evaluate trends and to estimate annual percentage changes (APCs). During the study period, there has been a statistically significant increment of the rate of esophageal adenocarcinoma (APC 3.70). The rates of elderly and of asymptomatic patients increased over time (APCs 0.98 and 6.24), whereas the rates of malnutrition, alcoholic drinking, and gastric ulcer decreased (APCs -1.50, -1.72, and -5.20). Reflux rate increased until 1997 and decreased thereafter (APCs 6.96 and -4.48), whereas the rate of Barrett esophagus increased until 1992 (APC 35.84) and then leveled. The rates of patients with previous neoplasms increased over time (APCs 3.22 and 4.86). There have been significant changes in systemic comorbidities, with an increase of hypertension and cardiac disease (APCs 7.56 and 1.86) and a decrease of advanced liver disease and pulmonary disease (APCs -2.67 and -1.74). The current EC patient has more often an esophageal adenocarcinoma and is more frequently elderly, asymptomatic, a survivor of previous neoplasms, and a patient with hypertension and cardiac disease than 30 years ago. On the contrary, malnutrition, alcoholic drinking, gastric ulcer, pulmonary disease, and advanced liver disease decreased.

A flexible architecture for advanced process control solutions

NASA Astrophysics Data System (ADS)

Faron, Kamyar; Iourovitski, Ilia

2005-05-01

Advanced Process Control (APC) is now mainstream practice in the semiconductor manufacturing industry. Over the past decade and a half APC has evolved from a "good idea", and "wouldn"t it be great" concept to mandatory manufacturing practice. APC developments have primarily dealt with two major thrusts, algorithms and infrastructure, and often the line between them has been blurred. The algorithms have evolved from very simple single variable solutions to sophisticated and cutting edge adaptive multivariable (input and output) solutions. Spending patterns in recent times have demanded that the economics of a comprehensive APC infrastructure be completely justified for any and all cost conscious manufacturers. There are studies suggesting integration costs as high as 60% of the total APC solution costs. Such cost prohibitive figures clearly diminish the return on APC investments. This has limited the acceptance and development of pure APC infrastructure solutions for many fabs. Modern APC solution architectures must satisfy the wide array of requirements from very manual R&D environments to very advanced and automated "lights out" manufacturing facilities. A majority of commercially available control solutions and most in house developed solutions lack important attributes of scalability, flexibility, and adaptability and hence require significant resources for integration, deployment, and maintenance. Many APC improvement efforts have been abandoned and delayed due to legacy systems and inadequate architectural design. Recent advancements (Service Oriented Architectures) in the software industry have delivered ideal technologies for delivering scalable, flexible, and reliable solutions that can seamlessly integrate into any fabs" existing system and business practices. In this publication we shall evaluate the various attributes of the architectures required by fabs and illustrate the benefits of a Service Oriented Architecture to satisfy these requirements. Blue Control Technologies has developed an advance service oriented architecture Run to Run Control System which addresses these requirements.

Meta-analysis of the association between APC promoter methylation and colorectal cancer.

PubMed

Ding, Zhenyu; Jiang, Tong; Piao, Ying; Han, Tao; Han, Yaling; Xie, Xiaodong

2015-01-01

Previous studies investigating the association between adenomatous polyposis coli (APC) gene promoter methylation and colorectal cancer (CRC) have yielded conflicting results. The aim of this study was to comprehensively evaluate the potential application of the detection of APC promoter methylation to the prevention and treatment of CRC. PubMed, Embase, and MEDLINE (results updated to October 2014) were searched for relevant studies. The effect size was defined as the weighted odds ratio (OR), which was calculated using either the fixed-effects or random-effects model. Prespecified subgroup and sensitivity analyses were conducted to evaluate potential heterogeneity among the included studies. Nineteen studies comprising 2,426 participants were selected for our meta-analysis. The pooled results of nine studies comprising a total of 740 subjects indicated that APC promoter methylation was significantly associated with CRC risk (pooled OR 5.53; 95% confidence interval [CI] 3.50-8.76; P<0.01). Eleven studies with a total of 1,219 patients evaluated the association between APC promoter methylation and the presence of CRC metastasis, and the pooled OR was 0.80 (95% CI 0.44-1.46; P=0.47). A meta-analysis conducted with four studies with a total of 467 patients found no significant correlation between APC promoter methylation and the presence of colorectal adenoma (pooled OR 1.85; 95% CI 0.67-5.10; P=0.23). No significant correlation between APC promoter methylation and patients' Dukes' stage, TNM stage, differentiation grade, age, or sex was identified. In conclusion, APC promoter methylation was found to be significantly associated with a higher risk of developing CRC. The findings indicate that APC promoter methylation may be a potential biomarker for the carcinogenesis of CRC.

Colorectal cancer risk variants at 8q23.3 and 11q23.1 are associated with disease phenotype in APC mutation carriers.

PubMed

Ghorbanoghli, Z; Nieuwenhuis, M H; Houwing-Duistermaat, J J; Jagmohan-Changur, S; Hes, F J; Tops, C M; Wagner, A; Aalfs, C M; Verhoef, S; Gómez García, E B; Sijmons, R H; Menko, F H; Letteboer, T G; Hoogerbrugge, N; van Wezel, T; Vasen, H F A; Wijnen, J T

2016-10-01

Familial adenomatous polyposis (FAP) is a dominantly inherited syndrome caused by germline mutations in the APC gene and characterized by the development of multiple colorectal adenomas and a high risk of developing colorectal cancer (CRC). The severity of polyposis is correlated with the site of the APC mutation. However, there is also phenotypic variability within families with the same underlying APC mutation, suggesting that additional factors influence the severity of polyposis. Genome-wide association studies identified several single nucleotide polymorphisms (SNPs) that are associated with CRC. We assessed whether these SNPs are associated with polyp multiplicity in proven APC mutation carriers. Sixteen CRC-associated SNPs were analysed in a cohort of 419 APC germline mutation carriers from 182 families. Clinical data were retrieved from the Dutch Polyposis Registry. Allele frequencies of the SNPs were compared for patients with <100 colorectal adenomas versus patients with ≥100 adenomas, using generalized estimating equations with the APC genotype as a covariate. We found a trend of association of two of the tested SNPs with the ≥100 adenoma phenotype: the C alleles of rs16892766 at 8q23.3 (OR 1.71, 95 % CI 1.05-2.76, p = 0.03, dominant model) and rs3802842 at 11q23.1 (OR 1.51, 95 % CI 1.03-2.22, p = 0.04, dominant model). We identified two risk variants that are associated with a more severe phenotype in APC mutation carriers. These risk variants may partly explain the phenotypic variability in families with the same APC gene defect. Further studies with a larger sample size are recommended to evaluate and confirm the phenotypic effect of these SNPs in FAP.

Low-level APC mutational mosaicism is the underlying cause in a substantial fraction of unexplained colorectal adenomatous polyposis cases.

PubMed

Spier, Isabel; Drichel, Dmitriy; Kerick, Martin; Kirfel, Jutta; Horpaopan, Sukanya; Laner, Andreas; Holzapfel, Stefanie; Peters, Sophia; Adam, Ronja; Zhao, Bixiao; Becker, Tim; Lifton, Richard P; Perner, Sven; Hoffmann, Per; Kristiansen, Glen; Timmermann, Bernd; Nöthen, Markus M; Holinski-Feder, Elke; Schweiger, Michal R; Aretz, Stefan

2016-03-01

In 30-50% of patients with colorectal adenomatous polyposis, no germline mutation in the known genes APC, causing familial adenomatous polyposis, MUTYH, causing MUTYH-associated polyposis, or POLE or POLD1, causing polymerase-proofreading-associated polyposis can be identified, although a hereditary aetiology is likely. This study aimed to explore the impact of APC mutational mosaicism in unexplained polyposis. To comprehensively screen for somatic low-level APC mosaicism, high-coverage next-generation sequencing of the APC gene was performed using DNA from leucocytes and a total of 53 colorectal tumours from 20 unrelated patients with unexplained sporadic adenomatous polyposis. APC mosaicism was assumed if the same loss-of-function APC mutation was present in ≥ 2 anatomically separated colorectal adenomas/carcinomas per patient. All mutations were validated using diverse methods. In 25% (5/20) of patients, somatic mosaicism of a pathogenic APC mutation was identified as underlying cause of the disease. In 2/5 cases, the mosaic level in leucocyte DNA was slightly below the sensitivity threshold of Sanger sequencing; while in 3/5 cases, the allelic fraction was either very low (0.1-1%) or no mutations were detectable. The majority of mosaic mutations were located outside the somatic mutation cluster region of the gene. The present data indicate a high prevalence of pathogenic mosaic APC mutations below the detection thresholds of routine diagnostics in adenomatous polyposis, even if high-coverage sequencing of leucocyte DNA alone is taken into account. This has important implications for both routine work-up and strategies to identify new causative genes in this patient group. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Transforming activity and therapeutic targeting of C-terminal-binding protein 2 in Apc-mutated neoplasia.

PubMed

Sumner, E T; Chawla, A T; Cororaton, A D; Koblinski, J E; Kovi, R C; Love, I M; Szomju, B B; Korwar, S; Ellis, K C; Grossman, S R

2017-08-17

Overexpression of the transcriptional coregulators C-terminal binding proteins 1 and 2 (CtBP1 and 2) occurs in many human solid tumors and is associated with poor prognosis. CtBP modulates oncogenic gene expression programs and is an emerging drug target, but its oncogenic role is unclear. Consistent with this oncogenic potential, exogenous CtBP2 transformed primary mouse and human cells to anchorage independence similarly to mutant H-Ras. To investigate CtBP's contribution to in vivo tumorigenesis, Apc min/+ mice, which succumb to massive intestinal polyposis, were bred to Ctbp2 +/- mice. CtBP interacts with adenomatous polyposis coli (APC) protein, and is stabilized in both APC-mutated human colon cancers and Apc min/+ intestinal polyps. Ctbp2 heterozygosity increased the median survival of Apc min/+ mice from 21 to 48 weeks, and reduced polyp formation by 90%, with Ctbp2 +/- polyps exhibiting reduced levels of β-catenin and its oncogenic transcriptional target, cyclin D1. CtBP's potential as a therapeutic target was studied by treating Apc min/+ mice with the CtBP small-molecule inhibitors 4-methylthio-2-oxobutyric acid and 2-hydroxy-imino phenylpyruvic acid, both of which reduced polyposis by more than half compared with vehicle treatment. Phenocopying Ctbp2 deletion, both Ctbp inhibitors caused substantial decreases in the protein level of Ctbp2, as well its oncogenic partner β-catenin, and the effects of the inhibitors on CtBP and β-catenin levels could be modeled in an APC-mutated human colon cancer cell line. CtBP2 is thus a druggable transforming oncoprotein critical for the evolution of neoplasia driven by Apc mutation.

Contribution of APC and MUTYH mutations to familial adenomatous polyposis susceptibility in Hungary.

PubMed

Papp, Janos; Kovacs, Marietta Eva; Matrai, Zoltan; Orosz, Enikő; Kásler, Miklós; Børresen-Dale, Anne-Lise; Olah, Edith

2016-01-01

Familial adenomatous polyposis (FAP) is a colorectal cancer predisposition syndrome with considerable genetic and phenotypic heterogeneity, defined by the development of multiple adenomas throughout the colorectum. FAP is caused either by monoallelic mutations in the adenomatous polyposis coli gene APC, or by biallelic germline mutations of MUTYH, this latter usually presenting with milder phenotype. The aim of the present study was to characterize the genotype and phenotype of Hungarian FAP patients. Mutation screening of 87 unrelated probands from FAP families (21 of them presented as the attenuated variant of the disease, showing <100 polyps) was performed using DNA sequencing and multiplex ligation-dependent probe amplification. Twenty-four different pathogenic mutations in APC were identified in 65 patients (75 %), including nine cases (37.5 %) with large genomic alterations. Twelve of the point mutations were novel. In addition, APC-negative samples were also tested for MUTYH mutations and we were able to identify biallelic pathogenic mutations in 23 % of these cases (5/22). Correlations between the localization of APC mutations and the clinical manifestations of the disease were observed, cases with a mutation in the codon 1200-1400 region showing earlier age of disease onset (p < 0.003). There were only a few, but definitive dissimilarities between APC- and MUTYH-associated FAP in our cohort: the age at onset of polyposis was significantly delayed for biallelic MUTYH mutation carriers as compared to patients with an APC mutation. Our data represent the first comprehensive study delineating the mutation spectra of both APC and MUTYH in Hungarian FAP families, and underscore the overlap between the clinical characteristics of APC- and MUTYH-associated phenotypes, necessitating a more appropriate clinical characterization of FAP families.

Dual control by Cdk1 phosphorylation of the budding yeast APC/C ubiquitin ligase activator Cdh1.

PubMed

Höckner, Sebastian; Neumann-Arnold, Lea; Seufert, Wolfgang

2016-07-15

The antagonism between cyclin-dependent kinases (Cdks) and the ubiquitin ligase APC/C-Cdh1 is central to eukaryotic cell cycle control. APC/C-Cdh1 targets cyclin B and other regulatory proteins for degradation, whereas Cdks disable APC/C-Cdh1 through phosphorylation of the Cdh1 activator protein at multiple sites. Budding yeast Cdh1 carries nine Cdk phosphorylation sites in its N-terminal regulatory domain, most or all of which contribute to inhibition. However, the precise role of individual sites has remained unclear. Here, we report that the Cdk phosphorylation sites of yeast Cdh1 are organized into autonomous subgroups and act through separate mechanisms. Cdk sites 1-3 had no direct effect on the APC/C binding of Cdh1 but inactivated a bipartite nuclear localization sequence (NLS) and thereby controlled the partitioning of Cdh1 between cytoplasm and nucleus. In contrast, Cdk sites 4-9 did not influence the cell cycle-regulated localization of Cdh1 but prevented its binding to the APC/C. Cdk sites 4-9 reside near two recently identified APC/C interaction motifs in a pattern conserved with the human Cdh1 orthologue. Thus a Cdk-inhibited NLS goes along with Cdk-inhibited APC/C binding sites in yeast Cdh1 to relay the negative control by Cdk1 phosphorylation of the ubiquitin ligase APC/C-Cdh1. © 2016 Höckner et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

[Purification and properties of Se-containing allophycocyanins from selenium rich Spirulina platensis].

PubMed

Huang, Zhi; Yang, Fang; Zheng, Wen-Jie

2006-06-01

Three Se-containing allophycocyanins (Se-APC) with high purity were purified from Se rich Spirulina platensis (Se-sp.) by hydroxyapatite chromatography, DEAE-52 anion-exchange chromatography and native gel preparative electrophoresis. Their biochemicial properties were explored by spectral scanning and electrophoresis analysis of Native-PAGE, SDS-PAGE and IEF on thin slab gel. Protein molecular weight (MW) of APC aggregation was determined by gel filter on Sephadex G-200 column. Se content of native and denatured Se-APC was detected by 2, 3-DAN fluorocence method. According to visible and fluorescence spectral character, three purified fractions of APC were identified to be APCI, APCII and APCIII. Native-PAGE and SDS-PAGE analysis revealed that they all shaped trimer (alphabeta) 3 of alpha and beta subunit with molecular mass of 18.3kDa and 15.7kDa, whereas APCI contains gamma subunit (about 32kDa) visibly and APCIII maybe contain the linker peptide of L(C)(8 - 10 kDa) based on their MW to be determined of 130.9, 98.1 and 106.30 kDa. IEF detection showed that the pl of Se-APCs was 4.76, 4.85 and 5.02 respectively. Se content of three purified Se-APCs were 316, 273 and 408 microg/g, which decreased about 25% after deaggregation treatment by 0.50 mol/L NaSCN and decreased more than 50% after denaturation treatment by 2-mercaptoethanol and reached to a steady content of 132 microg/g on average. These results indicated that Se incorporation into APC had no influence on function of energy transfer as well as biochemical property of APCs, and Se binding with APCs was highly relevant to its aggregation states whereas Se integrated steadily with its subunits.

Mutation analysis of the APC gene in Taiwanese FAP families: low incidence of APC germline mutation in a distinct subgroup of FAP families.

PubMed

Chiang, J M; Chen, H W; Tang, R P; Chen, J S; Changchien, C R; Hsieh, P S; Wang, J Y

2010-06-01

Familial adenomatous polyposis (FAP) is an autosomal-dominant disease caused by germline mutations in the adenomatous polyposis coli (APC) gene. The affected individuals develop colorectal polyposis and show various extra-colonic manifestations. In this study, we aimed to investigate the genetic and clinical characteristics of FAP in Taiwanese families and analyze the genotype-phenotype correlations. Blood samples were obtained from 66 FAP patients registered in the hereditary colorectal cancer database. Then, germline mutations in the APC genes of these 66 polyposis patients from 47 unrelated FAP families were analyzed. The germline-mutation-negative cases were analyzed by performing multiplex ligation-dependent probe amplification (MLPA) and single-strand conformation polymorphism (SSCP) analysis of the MUTYH gene. Among the analyzed families, 79% (37/47) of the families showed 28 APC mutations, including 19 frameshift mutations, 4 nonsense mutations, 3 genomic deletion mutations, 1 missense mutation, and 1 splice-site mutation. In addition, we identified 15 novel mutations in 32% (15/47) of the families. The cases in which APC mutations were not identified showed significantly lower incidence of profuse polyposis (P = 0.034) and gastroduodenal polyps (P = 0.027). Furthermore, FAP families in which some affected individuals had less than 100 polyps showed significant association with low incidence of APC germline mutations (P = 0.002). We have added the APC germline-mutation data for Taiwanese FAP patients and indicated the presence of an FAP subgroup comprising affected individuals with nonadenomatous polyps or less than 100 adenomatous polyps; this form of FAP is less frequently caused by germline mutations of the APC gene.

Alleviating neuropathic pain mechanical allodynia by increasing Cdh1 in the anterior cingulate cortex.

PubMed

Tan, Wei; Yao, Wen-Long; Hu, Rong; Lv, You-You; Wan, Li; Zhang, Chuan-Han; Zhu, Chang

2015-09-12

Plastic changes in the anterior cingulate cortex (ACC) are critical in the pathogenesis of pain hypersensitivity caused by injury to peripheral nerves. Cdh1, a co-activator subunit of anaphase-promoting complex/cyclosome (APC/C) regulates synaptic differentiation and transmission. Based on this, we hypothesised that the APC/C-Cdh1 played an important role in long-term plastic changes induced by neuropathic pain in ACC. We employed spared nerve injury (SNI) model in rat and found Cdh1 protein level in the ACC was down-regulated 3, 7 and 14 days after SNI surgery. We detected increase in c-Fos expression, numerical increase of organelles, swollen myelinated fibre and axon collapse of neuronal cells in the ACC of SNI rat. Additionally, AMPA receptor GluR1 subunit protein level was up-regulated on the membrane through a pathway that involves EphA4 mediated by APC/C-Cdh1, 3 and 7 days after SNI surgery. To confirm the effect of Cdh1 in neuropathic pain, Cdh1-expressing lentivirus was injected into the ACC of SNI rat. Intra-ACC treatment with Cdh1-expressing lentivirus vectors elevated Cdh1 levels, erased synaptic strengthening, as well as alleviating established mechanical allodynia in SNI rats. We also found Cdh1-expressing lentivirus normalised SNI-induced redistribution of AMPA receptor GluR1 subunit in ACC by regulating AMPA receptor trafficking. These results provide evidence that Cdh1 in ACC synapses may offer a novel therapeutic strategy for treating chronic neuropathic pain.

IL-33 activates tumor stroma to promote intestinal polyposis.

PubMed

Maywald, Rebecca L; Doerner, Stephanie K; Pastorelli, Luca; De Salvo, Carlo; Benton, Susan M; Dawson, Emily P; Lanza, Denise G; Berger, Nathan A; Markowitz, Sanford D; Lenz, Heinz-Josef; Nadeau, Joseph H; Pizarro, Theresa T; Heaney, Jason D

2015-05-12

Tumor epithelial cells develop within a microenvironment consisting of extracellular matrix, growth factors, and cytokines produced by nonepithelial stromal cells. In response to paracrine signals from tumor epithelia, stromal cells modify the microenvironment to promote tumor growth and metastasis. Here, we identify interleukin 33 (IL-33) as a regulator of tumor stromal cell activation and mediator of intestinal polyposis. In human colorectal cancer, IL-33 expression was induced in the tumor epithelium of adenomas and carcinomas, and expression of the IL-33 receptor, IL1RL1 (also referred to as IL1-R4 or ST2), localized predominantly to the stroma of adenoma and both the stroma and epithelium of carcinoma. Genetic and antibody abrogation of responsiveness to IL-33 in the Apc(Min/+) mouse model of intestinal tumorigenesis inhibited proliferation, induced apoptosis, and suppressed angiogenesis in adenomatous polyps, which reduced both tumor number and size. Similar to human adenomas, IL-33 expression localized to tumor epithelial cells and expression of IL1RL1 associated with two stromal cell types, subepithelial myofibroblasts and mast cells, in Apc(Min/+) polyps. In vitro, IL-33 stimulation of human subepithelial myofibroblasts induced the expression of extracellular matrix components and growth factors associated with intestinal tumor progression. IL-33 deficiency reduced mast cell accumulation in Apc(Min/+) polyps and suppressed the expression of mast cell-derived proteases and cytokines known to promote polyposis. Based on these findings, we propose that IL-33 derived from the tumor epithelium promotes polyposis through the coordinated activation of stromal cells and the formation of a protumorigenic microenvironment.

ApcMin, A Mutation in the Murine Apc Gene, Predisposes to Mammary Carcinomas and Focal Alveolar Hyperplasias

NASA Astrophysics Data System (ADS)

Moser, Amy Rapaich; Mattes, Ellen M.; Dove, William F.; Lindstrom, Mary J.; Haag, Jill D.; Gould, Michael N.

1993-10-01

ApcMin (Min, multiple intestinal neoplasia) is a point mutation in the murine homolog of the APC gene. Min/+ mice develop multiple intestinal adenomas, as do humans carrying germ-line mutations in APC. Female mice carrying Min are also prone to develop mammary tumors. Min/+ mammary glands are more sensitive to chemical carcinogenesis than are +/+ mammary glands. Transplantation of mammary cells from Min/+ or +/+ donors into +/+ hosts demonstrates that the propensity to develop mammary tumors is intrinsic to the Min/+ mammary cells. Long-term grafts of Min/+ mammary glands also gave rise to focal alveolar hyperplasias, indicating that the presence of the Min mutation also has a role in the development of these lesions.

Optimal utilization of a breast care advanced practice clinician.

PubMed

Russell, Katie W; Mone, Mary C; Serpico, Victoria J; Ward, Cori; Lynch, Joanna; Neumayer, Leigh A; Nelson, Edward W

2014-12-01

Incorporation of "lean" business philosophy within health care has the goal of adding value by reducing cost and improving quality. Applying these principles to the role of Advance Practice Clinicians (APCs) is relevant because they have become essential members of the healthcare team. An independent surgical breast care clinic directed by an APC was created with measurements of success to include the following: time to obtain an appointment, financial viability, and patient/APC/MD satisfaction. During the study period, there was a trend toward a decreased median time to obtain an appointment. Monthly APC charges increased from $388 to $30,800. The mean provider satisfaction score by Press Ganey was 96% for the APC and 95.8% for the surgeon. Both clinicians expressed significant satisfaction with clinic development. Overall, initiation of an APC breast clinic met the proposed goals of success. The use of lean philosophy demonstrates that implementation of change can result in added value in patient care. Copyright © 2014 Elsevier Inc. All rights reserved.

Definition of APC presentation of phosphoantigen (E)-4-hydroxy-3-methyl-but-2-enyl pyrophosphate to Vgamma2Vdelta 2 TCR.

PubMed

Wei, Huiyong; Huang, Dan; Lai, Xiaomin; Chen, Meiling; Zhong, Weihua; Wang, Richard; Chen, Zheng W

2008-10-01

Although microbial (E)-4-hydroxy-3-methyl-but-2-enyl pyrophosphate (HMBPP) can activate primate Vgamma2Vdelta2 T cells, molecular mechanisms by which HMBPP interacts with Vgamma2Vdelta2 T cells remain poorly characterized. Here, we developed soluble, tetrameric Vgamma2Vdelta2 TCR of rhesus macaques to define HMBPP/APC interaction with Vgamma2Vdelta2 TCR. While exogenous HMBPP was associated with APC membrane in an appreciable affinity, the membrane-associated HMBPP readily bound to the Vgamma2Vdelta2 TCR tetramer. The Vgamma2Vdelta2 TCR tetramer was shown to bind stably to HMBPP presented on membrane by various APC cell lines from humans and nonhuman primates but not those from mouse, rat, or pig. The Vgamma2Vdelta2 TCR tetramer also bound to the membrane-associated HMBPP on primary monocytes, B cells and T cells. Consistently, endogenous phosphoantigen produced in Mycobacterium-infected dendritic cells was transported and presented on membrane, and bound stably to the Vgamma2Vdelta2 TCR tetramer. The capability of APC to present HMBPP for recognition by Vgamma2Vdelta2 TCR was diminished after protease treatment of APC. Thus, our studies elucidated an affinity HMBPP-APC association conferring stable binding to the Vgamma2Vdelta2 TCR tetramer and the protease-sensitive nature of phosphoantigen presentation. The findings defined APC presentation of phosphoantigen HMBPP to Vgamma2Vdelta2 TCR.

Variational Bayes method for estimating transit route OD flows using APC data.

DOT National Transportation Integrated Search

2017-01-31

The focus of this study is on the use of large quantities of APC data to estimate OD flows : for transit bus routes. Since most OD flow estimation methodologies based on boarding and : alighting counts were developed before the prevalence of APC tech...

The Arts As Academic Education.

ERIC Educational Resources Information Center

Dorn, Charles M.

1984-01-01

The College Board's report "Academic Preparation for College" (APC) claims that study and performance in the arts are essential for success in college. Discussed are the APC report and its development, the APC arts statement and its evolution, and problems and prospects for implementation of the arts competencies. (RM)

More than two decades of Apc modeling in rodents

PubMed Central

Zeineldin, Maged; Neufeld, Kristi L.

2013-01-01

Mutation of tumor suppressor gene Adenomatous polyposis coli (APC) is an initiating step in most colon cancers. This review summarizes Apc models in mice and rats, with particular concentration on those most recently developed, phenotypic variation among different models, and genotype/ phenotype correlations. PMID:23333833

77 FR 45061 - Hospital Outpatient Prospective and Ambulatory Surgical Center Payment Systems and Quality...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-30

... radiation therapy (IORT), brachytherapy composite APC, multiple imaging composite APCs, cardiac... Outpatient Code Editor IOL Intraocular lens IOM Institute of Medicine IORT Intraoperative radiation treatment... Radiation Therapy (IORT) (APC 0412) a. Background b. CY 2013 Proposals for CPT Codes 77424, 77425, and 77469...

Apoptosis in neural crest cells by functional loss of APC tumor suppressor gene

PubMed Central

Hasegawa, Sumitaka; Sato, Tomoyuki; Akazawa, Hiroshi; Okada, Hitoshi; Maeno, Akiteru; Ito, Masaki; Sugitani, Yoshinobu; Shibata, Hiroyuki; Miyazaki, Jun-ichi; Katsuki, Motoya; Yamauchi, Yasutaka; Yamamura, Ken-ichi; Katamine, Shigeru; Noda, Tetsuo

2002-01-01

Apc is a gene associated with familial adenomatous polyposis coli (FAP) and its inactivation is a critical step in colorectal tumor formation. The protein product, adenomatous polyposis coli (APC), acts to down-regulate intracellular levels of β-catenin, a key signal transducer in the Wnt signaling. Conditional targeting of Apc in the neural crest of mice caused massive apoptosis of cephalic and cardiac neural crest cells at about 11.5 days post coitum, resulting in craniofacial and cardiac anomalies at birth. Notably, the apoptotic cells localized in the regions where β-catenin had accumulated. In contrast to its role in colorectal epithelial cells, inactivation of APC leads to dysregulation of β-catenin/Wnt signaling with resultant apoptosis in certain tissues including neural crest cells. PMID:11756652

Environmental effects on the compressive properties - Thermosetting vs. thermoplastic composites

NASA Technical Reports Server (NTRS)

Haque, A.; Jeelani, S.

1992-01-01

The influence of moisture and temperature on the compressive properties of graphite/epoxy and APC-2 materials systems was investigated to assess the viability of using APC-2 instead of graphite/epoxy. Data obtained indicate that the moisture absorption rate of T-300/epoxy is higher than that of APC-2. Thick plate with smaller surface area absorbs less moisture than thin plate with larger surface area. The compressive strength and modulus of APC-2 are higher than those of T-300/epoxy composite, and APC-2 sustains higher compressive strength in the presence of moisture. The compressive strength and modulus decrease with the increase of temperature in the range of 23-100 C. The compression failure was in the form of delamination, interlaminar shear, and end brooming.

Geopolymers prepared from DC plasma treated air pollution control (APC) residues glass: properties and characterisation of the binder phase.

PubMed

Kourti, Ioanna; Devaraj, Amutha Rani; Bustos, Ana Guerrero; Deegan, David; Boccaccini, Aldo R; Cheeseman, Christopher R

2011-11-30

Air pollution control (APC) residues have been blended with glass-forming additives and treated using DC plasma technology to produce a high calcium aluminosilicate glass (APC glass). This has been used to form geopolymer-glass composites that exhibit high strength and density, low porosity, low water absorption, low leaching and high acid resistance. The composites have a microstructure consisting of un-reacted residual APC glass particles imbedded in a complex geopolymer and C-S-H gel binder phase, and behave as particle reinforced composites. The work demonstrates that materials prepared from DC plasma treated APC residues have potential to be used to form high quality pre-cast products. Copyright © 2011 Elsevier B.V. All rights reserved.

Comparison of composition and absorption of sugarcane policosanols.

PubMed

Marinangeli, Christopher P F; Kassis, Amira N; Jain, Deepak; Ebine, Naoyuki; Cunnane, Stephen C; Jones, Peter J H

2007-02-01

Policosanols (PC) exist as very-long-chain alcohols derived from sugarcane currently used in many countries as a cholesterol-lowering therapy. PC purity and relative percentage composition have been suggested as primary reasons why the original Cuban PC (OPC) supplements possess lipid-lowering efficacy. The purpose of the present study was, first, to compare the relative percentage purity and PC composition of both OPC and alternative sources of PC (APC). A second objective was to feed Syrian hamsters a diet containing 0.275 mg PC/g of either the OPC or an APC product (APC1) and compare subsequent tissue, plasma and faecal PC levels. Five animals from the APC1 dietary group received a diet containing ten times the original amount of PC. Results indicate that the APC formulations have a composition that is highly consistent with the OPC supplement, with octacosanol being present within the cited 60-70 % range. PC were undetectable in the small intestine, liver, adipose or plasma in animals fed either source. Hamsters fed OPC excreted octacosanol (C28) more rapidly (P < 0.05) than hamsters receiving APC1. If the cholesterol-lowering efficacy of PC mixtures is dependent on their purity and composition, then sugarcane-derived APC products should possess similar therapeutic properties as the OPC supplement.

Upregulation of miR-3607 promotes lung adenocarcinoma proliferation by suppressing APC expression.

PubMed

Lin, Yong; Gu, Qiangye; Sun, Zongwen; Sheng, Baowei; Qi, Congcong; Liu, Bing; Fu, Tian; Liu, Cun; Zhang, Yan

2017-11-01

Lung cancer is the leading cause of worldwide cancer-related deaths, although many drugs and new therapeutic approaches have been used, the 5-years survival rate is still low for lung cancer patients. microRNAs have been shown to regulate lung cancer initiation and development, here we studied the role of miR-3607 in lung cancer cell proliferation. We found miR-3607 was upregulated in lung cancer tissues and cells, miR-3607 overexpression promoted lung cancer cell A549 proliferation determined by MTT assay, colony formation assay, anchorage-independent growth ability assay and bromodeoxyuridine incorporation assay, while the opposite phenotypes were shown when miR-3607 was knocked down. Predicted analysis suggested a Wnt signaling pathway regulator adenomatous polyposis coli (APC) was the target of miR-3607, miR-3607 could directly bind to the 3'UTR of APC, and promoted Cyclin D1 and c-Myc expression which can be suppressed by APC. Double knockdown of miR-3607 and APC copied the phenotypes of miR-3607 overexpression, suggesting miR-3607 promoted lung cancer cell A549 proliferation by targeting APC. In conclusion, our study suggested miR-3607 contributes to lung cancer cell proliferation by inhibiting APC. Copyright © 2017. Published by Elsevier Masson SAS.

Anti-atopic dermatitis effects and the mechanism of lactic acid bacteria isolated from Mongolian fermented milk.

PubMed

Hayashi, Atsushi; Kimura, Makoto; Nakamura, Yusaku; Yasui, Hisako

2009-05-01

We investigated the anti-allergic effects of one strain (T120) of a lactic acid bacteria (LAB) isolated from Mongolian fermented milk using atopic dermatitis (AD) model mice (NC/Nga mice). Strain T120 has already been identified as Enterococcus faecium and shown to induce strong production of IL-12 (Kimura et al. 2006). In in vitro studies, strain T120 suppressed total IgE production and induced IL-12 and IFN-gamma production by splenocytes of NC/Nga mice. The additional examination of various neutralization antibodies was performed to elucidate in detail the mechanism of depressed IgE production by strain T120. As a result, it became clear that IL-12 induced by strain T120 increased production of IFN-gamma and total IgE production was mainly controlled by the IFN-gamma. In order to define the cells which produce IL-12 powerfully by this strain, antigen-presenting cells (APCs) such as macrophages and dendritic cells (DCs) were removed from the splenocytes, and the reactivity of these cells to the strain was examined. Induction of IL-12 and IFN-gamma by strain T120 became significantly very low by removal of APCs from splenocytes. Therefore, it was clear that strain T120 acted on APCs and induced production of IL-12. Further, this strain enhanced the production of IL-10 by splenocytes. In in vivo studies, intraperitoneal injection of strain T120 inhibited serum IgE elevation and atopic dermatitis symptoms in NC/Nga mice. These results suggest that an anti-allergic effect of strain T120 depends on the increased production of IL-12 by APCs activated by the strain and following the increased production of IFN-gamma. Further, activation of regulatory T cells by strain T120 may inhibit atopic disease.

CD44-positive cells are candidates for astrocyte precursor cells in developing mouse cerebellum.

PubMed

Cai, Na; Kurachi, Masashi; Shibasaki, Koji; Okano-Uchida, Takayuki; Ishizaki, Yasuki

2012-03-01

Neural stem cells are generally considered to be committed to becoming precursor cells before terminally differentiating into either neurons or glial cells during neural development. Neuronal and oligodendrocyte precursor cells have been identified in several areas in the murine central nervous system. The presence of astrocyte precursor cells (APCs) is not so well understood. The present study provides several lines of evidence that CD44-positive cells are APCs in the early postnatal mouse cerebellum. In developing mouse cerebellum, CD44-positive cells, mostly located in the white matter, were positive for the markers of the astrocyte lineage, but negative for the markers of mature astrocytes. CD44-positive cells were purified from postnatal cerebellum by fluorescence-activated cell sorting and characterized in vitro. In the absence of any signaling molecule, many cells died by apoptosis. The surviving cells gradually expressed glial fibrillary acidic protein, a marker for mature astrocytes, indicating that differentiation into mature astrocytes is the default program for these cells. The cells produced no neurospheres nor neurons nor oligodendrocytes under any condition examined, indicating these cells are not neural stem cells. Leukemia inhibitory factor greatly promoted astrocytic differentiation of CD44-positive cells, whereas bone morphogenetic protein 4 (BMP4) did not. Fibroblast growth factor-2 was a potent mitogen for these cells, but was insufficient for survival. BMP4 inhibited activation of caspase-3 and greatly promoted survival, suggesting a novel role for BMP4 in the control of development of astrocytes in cerebellum. We isolated and characterized only CD44 strongly positive large cells and discarded small and/or CD44 weakly positive cells in this study. Further studies are necessary to characterize these cells to help determine whether CD44 is a selective and specific marker for APCs in the developing mouse cerebellum. In conclusion, we succeeded in preparing APC candidates from developing mouse cerebellum, characterized them in vitro, and found that BMPs are survival factors for these cells.

Hypothesis: Induction of biomarkers for detection of colonic neoplasms

PubMed Central

Bordonaro, Michael; Lazarova, Darina

2018-01-01

The signing of the National Cancer Act of 1971 by President Nixon marked the beginning of our war on cancer. More than 45 years later, the war is still going steady, with the enemy being almost as strong as in 1971. Furthermore, the increasing rates of obesity not only among adults, but among children and adolescents, are the likely cause for the 30-year trend of colon cancer (CC) becoming a disease of the younger population in the U.S. These trends, however, have not spurred the development of novel screening approaches for CC. Considering the need for a sensitive and non-invasive detection of early stage neoplastic lesions in the colon, we propose the development of a test based on a novel concept - the concept of induced biomarkers. The proposal is based upon our findings that the food additives propolis and gamma-cyclodextrin (gCD) (a) decrease the neoplastic burden in normal weight and obese ApcMin mice, a model of early stage intestinal neoplasia, and (b) elicit significant changes in the serum proteome in ApcMin mice. We posit that gCD and propolis induce the release of neoplasm-associated biomarkers in systemic circulation (e.g., metabolites, neoplastic, apoptotic, and immune response proteins), and these markers could be used to detect early stage intestinal neoplasms. Additional dietary bioactives may also elicit a complement of induced markers. The hypothesis could be ascertained by utilizing a mouse model, the Apc+/1638Nmice, as well as through human subject studies that integrate proteomics and metabolomics analyses. The concept of detecting inducible markers of colonic neoplasms is novel, and is substantiated by the significant physiological effects of gCD and propolis on neoplastic colonic cells in culture and on early neoplastic development in ApcMinmice. The long-term objective is to develop a minimally invasive method that detects early stage neoplastic development in the human colon. PMID:29290782

Healing property of the Piper betel phenol, allylpyrocatechol against indomethacin-induced stomach ulceration and mechanism of action

PubMed Central

Bhattacharya, S; Banerjee, D; Bauri, AK; Chattopadhyay, S; Bandyopadhyay, SK

2007-01-01

AIM: To evaluate the protective activity of allylpyrocatechol (APC), the major antioxidant constituent of Piper betel, against the indomethacin-induced stomach ulceration in the rat model and correlates with its antioxidative and mucin protecting properties. METHODS: Male Sprague-Dawley rats were divided into five groups. Normal control rats (group I) were given the vehicle oral dose of gum acacia in distilled water (1 mL per rat); ulcerated control and treated rats (groups II-V) were given a single dose of indomethacin (30 mg/kg body wt.); group II rats were sacrificed 4 h after indomethacin administration; groups III-V rats were given the vehicle (1 mL per rat) or APC (2 mg/kg body wt.) or misoprostol (1.43 μg/kg body wt.) once daily by oral intubation for 7 d starting from 4 h after the indomethacin administration. After 7 d, the stomach tissues were excised for histological examination and biochemical analysis. RESULTS: Treatment with APC (2 mg/kg body wt per day) and misoprostol (1.43 μg/kg body wt per day) for 7 d could effectively heal the stomach ulceration as revealed from the ulcer index and histopathological studies. Compared to the zero day ulcerated group, treatment with APC and misoprostol reduced the ulcer index by 93.4% and 85.4% respectively (P < 0.05). Both APC and misoprostol accelerated ulcer healing observed in natural recovery (P < 0.05), their respective healing capacities not being significantly different. The healing capacities of APC and misoprostol could be attributed to their antioxidant activity as well as the ability to enhance the mucin content of the gastric tissues. Compared to the ulcerated untreated rats, those treated with APC and misoprostol showed near normal MDA levels, while the protein levels were 86% and 78% of the normal value respectively (P < 0.05). Likewise, both APC and misoprostol increased the SOD, catalase, and mucin levels significantly (P < 0.05), the effect of APC being better. CONCLUSION: APC can protect indomethacin-induced gastric ulceration due to its antioxidative and mucin protecting properties. PMID:17659730

Healing property of the Piper betel phenol, allylpyrocatechol against indomethacin-induced stomach ulceration and mechanism of action.

PubMed

Bhattacharya, S; Banerjee, D; Bauri, A-K; Chattopadhyay, S; Bandyopadhyay, S-K

2007-07-21

To evaluate the protective activity of allylpyrocatechol (APC), the major antioxidant constituent of Piper betel, against the indomethacin-induced stomach ulceration in the rat model and correlates with its antioxidative and mucin protecting properties. Male Sprague-Dawley rats were divided into five groups. Normal control rats (group I) were given the vehicle oral dose of gum acacia in distilled water (1 mL per rat); ulcerated control and treated rats (groups II-V) were given a single dose of indomethacin (30 mg/kg body wt.); group II rats were sacrificed 4 h after indomethacin administration; groups III-V rats were given the vehicle (1 mL per rat) or APC (2 mg/kg body wt.) or misoprostol (1.43 mug/kg body wt.) once daily by oral intubation for 7 d starting from 4 h after the indomethacin administration. After 7 d, the stomach tissues were excised for histological examination and biochemical analysis. Treatment with APC (2 mg/kg body wt per day) and misoprostol (1.43 mug/kg body wt per day) for 7 d could effectively heal the stomach ulceration as revealed from the ulcer index and histopathological studies. Compared to the zero day ulcerated group, treatment with APC and misoprostol reduced the ulcer index by 93.4% and 85.4% respectively (P < 0.05). Both APC and misoprostol accelerated ulcer healing observed in natural recovery (P < 0.05), their respective healing capacities not being significantly different. The healing capacities of APC and misoprostol could be attributed to their antioxidant activity as well as the ability to enhance the mucin content of the gastric tissues. Compared to the ulcerated untreated rats, those treated with APC and misoprostol showed near normal MDA levels, while the protein levels were 86% and 78% of the normal value respectively (P < 0.05). Likewise, both APC and misoprostol increased the SOD, catalase, and mucin levels significantly (P < 0.05), the effect of APC being better. APC can protect indomethacin-induced gastric ulceration due to its antioxidative and mucin protecting properties.

Inhibitory effects of thymus-independent type 2 antigens on MHC class II-restricted antigen presentation: comparative analysis of carbohydrate structures and the antigen presenting cell.

PubMed

González-Fernández, M; Carrasco-Marín, E; Alvarez-Domínguez, C; Outschoorn, I M; Leyva-Cobián, F

1997-02-25

The role of thymus-independent type 2 (TI-2) antigens (polysaccharides) on the MHC-II-restricted processing of protein antigens was studied in vitro. In general, antigen presentation is inhibited when both peritoneal and splenic macrophages (M phi) as well as Küpffer cells (KC) are preincubated with acidic polysaccharides or branched dextrans. However, the inhibitory effect of neutral polysaccharides was minimal when KC were used as antigen presenting cells (APC). Morphological evaluation of the uptake of fluoresceinated polysaccharides clearly correlates with this selective and differential interference. Polysaccharides do not block MHC-I-restricted antigen presentation. Some chemical characteristics shared by different saccharides seem to be specially related to their potential inhibitory abilities: (i) those where two anomeric carbon atoms of two interlinked sugars and (ii) those containing several sulfate groups per disaccharide repeating unit. No polysaccharide being inhibitory in M phi abrogated antigen processing in other APC: lipopolysaccharide-activated B cells, B lymphoma cells, or dendritic cells (DC). Using radiolabeled polysaccharides it was observed that DC and B cells incorporated less radioactivity as a function of time than M phi. Morphological evaluation of these different APC incubated for extended periods of time with inhibitory concentrations of polysaccharides revealed intense cytoplasmic vacuolization in M phi but not in B cells or DC. The large majority of M phi lysosomes containing polysaccharides fail to fuse with incoming endocytic vesicles and delivery of fluid-phase tracers was reduced, suggesting that indigestible carbohydrates reduced the fusion of these loaded lysosomes with endosomes containing recently internalized tracers. It is suggested that the main causes of this antigen presentation blockade are (i) the chemical characteristics of certain carbohydrates and whether the specific enzymatic machinery for their intracellular degradation exists; and (ii) the different phagocytic abilities of distinct APC populations, fluid-phase pinocytosis and receptor-mediated saccharide uptake, and existence of a differential antigen-processing pathway in M phi and DC or B cells, which could be based on a polysaccharide-inhibited step present in M phi but unaffected or irrelevant in both B cells and DC.

A Rising Trend in the Incidence of Advanced Gastric Cancer in Young Hispanic Men

PubMed Central

Merchant, Shaila J.; Kim, Joseph; Choi, Audrey H.; Sun, Virginia; Chao, Joseph; Nelson, Rebecca

2017-01-01

BACKGROUND Although the incidence of gastric cancer has been decreasing, recent reports suggest an increased rate in select populations. We sought to evaluate trends in gastric cancer incidence to identify high risk populations. METHODS Gastric cancer incidence rates from 1992 to 2011 were computed using the Surveillance, Epidemiology and End Results (SEER) registry. We evaluated trends in incidence rates by calculating annual percent change (APC) across 3 age groups (20–49, 50–64, ≥65) and 4 racial/ethnic groups (Hispanics, non-Hispanic Whites, Blacks, and Asian/Pacific Islanders). RESULTS We identified 41,428 patients with gastric cancer. For the entire cohort over the study period, the APC was decreased. When patients were grouped according to sex, APC was flat or decreased in women regardless of age or race/ethnicity. APC was also flat or decreased for all men except young Hispanic males (20–49 years), who had an increased APC of nearly 1.6% per year (1.55%, 95% CI:0.26 to 2.86%). Furthermore, young Hispanic males were the only group to have increased incidence of Stage 4 disease (APC 4.34%, 95% CI:2.76 to 5.94%) and poorly differentiated tumors (APC 2.08%, 95% CI:0.48 to 3.70%). CONCLUSIONS The APC of young Hispanic male gastric cancer places it among the top cancers with rising incidence in the United States. This is concomitant with increased incidence of advanced disease at presentation. This major public health concern warrants additional research to determine the etiology of the increasing incidence in this group. PMID:26924751

Regression of atherosclerosis with apple procyanidins by activating the ATP-binding cassette subfamily A member 1 in a rabbit model.

PubMed

Wang, Liang; Fumoto, Toshio; Masumoto, Saeko; Shoji, Toshihiko; Miura, Tomisato; Naraoka, Masato; Matsuda, Naoya; Imaizumi, Tadaatsu; Ohkuma, Hiroki

2017-03-01

Apple polyphenol contains abundant procyanidins, which have been associated with an anti-atherosclerosis and cholesterol-lowering effect. The aim of this study was to investigate whether apple procyanidins (APCs) feature therapeutic efficacy in terms of regressing atherosclerosis and whether this efficacy is due to mechanisms other than a cholesterol-lowering effect. After eight weeks on an atherogenic diet, rabbits were given a normal diet for another eight weeks to normalize the increased serum lipids level. The rabbits in the baseline group were sacrificed at this stage. The control group was subsequently fed a normal diet for eight weeks, while the APCs group was administrated 50 mg/kg/day of APCs in addition to the normal diet. Serum lipids and aortic intimal-medial thickness (IMT) were serially examined, and the resected aorta was examined histologically and through molecular biology. Aortic IMT on ultrasonography and the lipid accumulation area examined using Sudan IV staining were significantly reduced in the APCs group as compared to the control group. Serum lipid profiles were not different between the groups. Immunohistochemistry showed significantly decreased staining of an oxidative stress marker and significantly increased staining of ATP-binding cassette subfamily A member 1 (ABCA1) in the APCs group. Western blotting and RT-PCR also showed increased expression of ABCA1 mRNA and its protein in the APCs group. This study revealed that APCs administration causes a regression of atherosclerosis. APCs might hold promise as an anti-atherosclerotic agent. Copyright © 2017 Elsevier B.V. All rights reserved.

Nek2A destruction marks APC/C activation at the prophase-to-prometaphase transition by spindle-checkpoint-restricted Cdc20.

PubMed

Boekhout, Michiel; Wolthuis, Rob

2015-04-15

Nek2 isoform A (Nek2A) is a presumed substrate of the anaphase-promoting complex/cyclosome containing Cdc20 (APC/C(Cdc20)). Nek2A, like cyclin A, is degraded in mitosis while the spindle checkpoint is active. Cyclin A prevents spindle checkpoint proteins from binding to Cdc20 and is recruited to the APC/C in prometaphase. We found that Nek2A and cyclin A avoid being stabilized by the spindle checkpoint in different ways. First, enhancing mitotic checkpoint complex (MCC) formation by nocodazole treatment inhibited the degradation of geminin and cyclin A, whereas Nek2A disappeared at a normal rate. Second, depleting Cdc20 effectively stabilized cyclin A but not Nek2A. Nevertheless, Nek2A destruction crucially depended on Cdc20 binding to the APC/C. Third, in contrast to cyclin A, Nek2A was recruited to the APC/C before the start of mitosis. Interestingly, the spindle checkpoint very effectively stabilized an APC/C-binding mutant of Nek2A, which required the Nek2A KEN box. Apparently, in cells, the spindle checkpoint primarily prevents Cdc20 from binding destruction motifs. Nek2A disappearance marks the prophase-to-prometaphase transition, when Cdc20, regardless of the spindle checkpoint, activates the APC/C. However, Mad2 depletion accelerated Nek2A destruction, showing that spindle checkpoint release further increases APC/C(Cdc20) catalytic activity. © 2015. Published by The Company of Biologists Ltd.

APC/C and retinoblastoma interaction: cross-talk of retinoblastoma protein with the ubiquitin proteasome pathway.

PubMed

Ramanujan, Ajeena; Tiwari, Swati

2016-10-01

The ubiquitin (Ub) ligase anaphase promoting complex/cyclosome (APC/C) and the tumour suppressor retinoblastoma protein (pRB) play key roles in cell cycle regulation. APC/C is a critical regulator of mitosis and G1-phase of the cell cycle whereas pRB keeps a check on proliferation by inhibiting transition to the S-phase. APC/C and pRB interact with each other via the co-activator of APC/C, FZR1, providing an alternative pathway of regulation of G1 to S transition by pRB using a post-translational mechanism. Both pRB and FZR1 have complex roles and are implicated not only in regulation of cell proliferation but also in differentiation, quiescence, apoptosis, maintenance of chromosomal integrity and metabolism. Both are also targeted by transforming viruses. We discuss recent advances in our understanding of the involvement of APC/C and pRB in cell cycle based decisions and how these insights will be useful for development of anti-cancer and anti-viral drugs. © 2016 The Author(s).

APC/C and retinoblastoma interaction: cross-talk of retinoblastoma protein with the ubiquitin proteasome pathway

PubMed Central

Ramanujan, Ajeena; Tiwari, Swati

2016-01-01

The ubiquitin (Ub) ligase anaphase promoting complex/cyclosome (APC/C) and the tumour suppressor retinoblastoma protein (pRB) play key roles in cell cycle regulation. APC/C is a critical regulator of mitosis and G1-phase of the cell cycle whereas pRB keeps a check on proliferation by inhibiting transition to the S-phase. APC/C and pRB interact with each other via the co-activator of APC/C, FZR1, providing an alternative pathway of regulation of G1 to S transition by pRB using a post-translational mechanism. Both pRB and FZR1 have complex roles and are implicated not only in regulation of cell proliferation but also in differentiation, quiescence, apoptosis, maintenance of chromosomal integrity and metabolism. Both are also targeted by transforming viruses. We discuss recent advances in our understanding of the involvement of APC/C and pRB in cell cycle based decisions and how these insights will be useful for development of anti-cancer and anti-viral drugs. PMID:27402801

Environmental effects on the compressive properties - Thermosetting vs. thermoplastic composites

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

Haque, A.; Jeelani, S.

1992-02-01

The influence of moisture and temperature on the compressive properties of graphite/epoxy and APC-2 materials systems was investigated to assess the viability of using APC-2 instead of graphite/epoxy. Data obtained indicate that the moisture absorption rate of T-300/epoxy is higher than that of APC-2. Thick plate with smaller surface area absorbs less moisture than thin plate with larger surface area. The compressive strength and modulus of APC-2 are higher than those of T-300/epoxy composite, and APC-2 sustains higher compressive strength in the presence of moisture. The compressive strength and modulus decrease with the increase of temperature in the range ofmore » 23-100 C. The compression failure was in the form of delamination, interlaminar shear, and end brooming. 9 refs.« less

Estimating average annual per cent change in trend analysis

PubMed Central

Clegg, Limin X; Hankey, Benjamin F; Tiwari, Ram; Feuer, Eric J; Edwards, Brenda K

2009-01-01

Trends in incidence or mortality rates over a specified time interval are usually described by the conventional annual per cent change (cAPC), under the assumption of a constant rate of change. When this assumption does not hold over the entire time interval, the trend may be characterized using the annual per cent changes from segmented analysis (sAPCs). This approach assumes that the change in rates is constant over each time partition defined by the transition points, but varies among different time partitions. Different groups (e.g. racial subgroups), however, may have different transition points and thus different time partitions over which they have constant rates of change, making comparison of sAPCs problematic across groups over a common time interval of interest (e.g. the past 10 years). We propose a new measure, the average annual per cent change (AAPC), which uses sAPCs to summarize and compare trends for a specific time period. The advantage of the proposed AAPC is that it takes into account the trend transitions, whereas cAPC does not and can lead to erroneous conclusions. In addition, when the trend is constant over the entire time interval of interest, the AAPC has the advantage of reducing to both cAPC and sAPC. Moreover, because the estimated AAPC is based on the segmented analysis over the entire data series, any selected subinterval within a single time partition will yield the same AAPC estimate—that is it will be equal to the estimated sAPC for that time partition. The cAPC, however, is re-estimated using data only from that selected subinterval; thus, its estimate may be sensitive to the subinterval selected. The AAPC estimation has been incorporated into the segmented regression (free) software Joinpoint, which is used by many registries throughout the world for characterizing trends in cancer rates. Copyright © 2009 John Wiley & Sons, Ltd. PMID:19856324

Association of APC I1307K and E1317Q polymorphisms with colorectal cancer among Egyptian subjects.

PubMed

Abdel-Malak, Camelia; Darwish, Hossam; Elsaid, Afaf; El-Tarapely, Fatma; Elshazli, Rami

2016-01-01

Colorectal cancer is a multifactorial disease that involves both environmental and genetic factors. The gene encoding adenomatous polyposis coli (APC) has been reported to be associated with colorectal cancer (CRC) risk in several ethnic populations. The aim of this work is to assess the association of the APC I1307K and E1317Q polymorphisms with CRC risk among Egyptian subjects. This study included 120 unrelated CRC Egyptian patients who were compared to 100 healthy controls from the same locality. For all subjects, DNA was genotyped for APC I1307K and E1317Q polymorphisms using the PCR-ARMS technique. The frequency of APC I1307K carrier (TA+AA genotypes) was noted to be significantly higher among cases with CRC compared to controls (18.3 vs. 9.0 %, OR 2.58, 95 % CI 1.09-6.09, p = 0.03). Also the frequency of the APC I1307K A allele was significantly higher among cases compared to controls (10.4 vs. 4.5 %, OR 2.47; 95 % CI 1.12-5.42, p = 0.03). On the contrast, the frequencies of APC E1317Q GC genotype and C allele showed no significant difference among CRC patients compared to controls (3.3 vs. 2.0 %, OR 1.69; 95 % CI 0.30-9.42, p = 0.69 and 2.1 vs. 1.0 %, OR 2.11; 95 % CI 0.40-10.97, p = 0.46, respectively). Cases of the APC I1307K and E1317Q carriers (TA+AA and GC) showed no significant difference compared to those with I1307K and E1317Q non-carriers (TT and GG) regarding their clinical and laboratory markers. APC I1307K variant was associated with an increased risk of CRC among Egyptian subjects.

Tissue-Specific Effects of Reduced β-catenin Expression on Adenomatous Polyposis Coli Mutation-Instigated Tumorigenesis in Mouse Colon and Ovarian Epithelium

PubMed Central

Feng, Ying; Sakamoto, Naoya; Wu, Rong; Liu, Jie-yu; Wiese, Alexandra; Green, Maranne E.; Green, Megan; Akyol, Aytekin; Roy, Badal C.; Zhai, Yali; Cho, Kathleen R.; Fearon, Eric R.

2015-01-01

Adenomatous polyposis coli (APC) inactivating mutations are present in most human colorectal cancers and some other cancers. The APC protein regulates the β-catenin protein pool that functions as a co-activator of T cell factor (TCF)-regulated transcription in Wnt pathway signaling. We studied effects of reduced dosage of the Ctnnb1 gene encoding β-catenin in Apc-mutation-induced colon and ovarian mouse tumorigenesis and cell culture models. Concurrent somatic inactivation of one Ctnnb1 allele, dramatically inhibited Apc mutation-induced colon polyposis and greatly extended Apc-mutant mouse survival. Ctnnb1 hemizygous dose markedly inhibited increases in β-catenin levels in the cytoplasm and nucleus following Apc inactivation in colon epithelium, with attenuated expression of key β-catenin/TCF-regulated target genes, including those encoding the EphB2/B3 receptors, the stem cell marker Lgr5, and Myc, leading to maintenance of crypt compartmentalization and restriction of stem and proliferating cells to the crypt base. A critical threshold for β-catenin levels in TCF-regulated transcription was uncovered for Apc mutation-induced effects in colon epithelium, along with evidence of a feed-forward role for β-catenin in Ctnnb1 gene expression and CTNNB1 transcription. The active β-catenin protein pool was highly sensitive to CTNNB1 transcript levels in colon cancer cells. In mouse ovarian endometrioid adenocarcinomas (OEAs) arising from Apc- and Pten-inactivation, while Ctnnb1 hemizygous dose affected β-catenin levels and some β-catenin/TCF target genes, Myc induction was retained and OEAs arose in a fashion akin to that seen with intact Ctnnb1 gene dose. Our findings indicate Ctnnb1 gene dose exerts tissue-specific differences in Apc mutation-instigated tumorigenesis. Differential expression of selected β-catenin/TCF-regulated genes, such as Myc, likely underlies context-dependent effects of Ctnnb1 gene dosage in tumorigenesis. PMID:26528816

Prognostic role of APC and RASSF1A promoter methylation status in cell free circulating DNA of operable gastric cancer patients.

PubMed

Balgkouranidou, I; Matthaios, D; Karayiannakis, A; Bolanaki, H; Michailidis, P; Xenidis, N; Amarantidis, K; Chelis, L; Trypsianis, G; Chatzaki, E; Lianidou, E S; Kakolyris, S

2015-08-01

Gastric carcinogenesis is a multistep process including not only genetic mutations but also epigenetic alterations. The best known and more frequent epigenetic alteration is DNA methylation affecting tumor suppressor genes that may be involved in various carcinogenetic pathways. The aim of the present study was to investigate the methylation status of APC promoter 1A and RASSF1A promoter in cell free DNA of operable gastric cancer patients. Using methylation specific PCR, we examined the methylation status of APC promoter 1A and RASSF1A promoter in 73 blood samples obtained from patients with gastric cancer. APC and RASSF1A promoters were found to be methylated in 61 (83.6%) and 50 (68.5%) of the 73 gastric cancer samples examined, but in none of the healthy control samples (p < 0.001). A significant association between methylated RASSF1A promoter status and lymph node positivity was observed (p = 0.005). Additionally, a significant correlation between a methylated APC promoter and elevated CEA (p = 0.033) as well as CA-19.9 (p = 0.032) levels, was noticed. The Kaplan-Meier estimates of survival, significantly favored patients with a non-methylated APC promoter status (p = 0.008). No other significant correlations between APC and RASSF1A methylation status and different tumor variables examined was observed. Serum RASSF1A and APC promoter hypermethylation is a frequent epigenetic event in patients with early operable gastric cancer. The observed correlations between APC promoter methylation status and survival as well as between a hypermethylated RASSF1A promoter and nodal positivity may be indicative of a prognostic role for those genes in early operable gastric cancer. Additional studies, in a larger cohort of patients are required to further explore whether these findings could serve as potential molecular biomarkers of survival and/or response to specific treatments. Copyright © 2015 Elsevier B.V. All rights reserved.

Laser CO2 tonsillotomy versus argon plasma coagulation (APC) tonsillotomy: A retrospective study with 10-year follow-up.

PubMed

Papaspyrou, Giorgos; Linxweiler, Maximilian; Knöbber, Dirk; Schick, Bernhard; Al Kadah, Basel

2017-01-01

Tonsillotomy is increasingly gaining acceptance as the treatment for tonsillar hyperplasia resulting in obstructive symptoms. The aim of this study was to compare the long-term results of CO 2 laser tonsillotomy with those of argon plasma coagulation (APC) tonsillotomy. The data of 64 children, aged 2-10 years (mean 4.7 years), treated in the Department of Otolaryngology, Head and Neck Surgery, in Homburg, Germany with APC (36 patients) or CO 2 laser (28 patients) for tonsillar hyperplasia between June 2004 and December 2004 were available for analysis. Forty-five (APC: 26 patients, CO 2 : 19 patients) of the 64 patients (70.3%) could be contacted and were available for follow-up in a telephone survey conducted 10 years after surgery. The mean operation time was 17 min (range 10-25 min) in the APC group and 23 min (range 13-32 min) in the CO 2 group (p = 0.0003). No case of intra- or postoperative bleeding was documented. One minor intraoperative complication in the form of a superficial lip burn was documented in the APC group. During the minimum 10 years of follow-up, 1 patient treated with APC underwent a surgical revision because of tonsillar regrowth, whereas in the group of patients treated with CO 2 , no surgical revision was needed. Regarding the parents' assessment of their children's symptoms, 89.4% of the parents of the CO 2 laser group and 84.6% of the parents of the APC group reported that the overall long-term operation results of their children to be "very satisfying." Regarding complications, the need for secondary tonsillectomy, and parents' satisfaction, no statistically significant differences were found. Both CO 2 laser tonsillotomy and APC tonsillotomy are safe procedures leading to very satisfying results with respect to intra- and postoperative complications. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Decomposing Black-White Disparities in Heart Disease Mortality in the United States, 1973–2010: An Age-Period-Cohort Analysis

PubMed Central

Kramer, Michael R.; Valderrama, Amy L.; Casper, Michele L.

2015-01-01

Against the backdrop of late 20th century declines in heart disease mortality in the United States, race-specific rates diverged because of slower declines among blacks compared with whites. To characterize the temporal dynamics of emerging black-white racial disparities in heart disease mortality, we decomposed race-sex–specific trends in an age-period-cohort (APC) analysis of US mortality data for all diseases of the heart among adults aged ≥35 years from 1973 to 2010. The black-white gap was largest among adults aged 35–59 years (rate ratios ranged from 1.2 to 2.7 for men and from 2.3 to 4.0 for women) and widened with successive birth cohorts, particularly for men. APC model estimates suggested strong independent trends across generations (“cohort effects”) but only modest period changes. Among men, cohort-specific black-white racial differences emerged in the 1920–1960 birth cohorts. The apparent strength of the cohort trends raises questions about life-course inequalities in the social and health environments experienced by blacks and whites which could have affected their biomedical and behavioral risk factors for heart disease. The APC results suggest that the genesis of racial disparities is neither static nor restricted to a single time scale such as age or period, and they support the importance of equity in life-course exposures for reducing racial disparities in heart disease. PMID:26199382

Fringe field switching AMLCD technology in military and consumer applications

NASA Astrophysics Data System (ADS)

Niemczyk, James

2006-05-01

American Panel Corporation (APC) designs and delivers customized AMLCD products for aircraft cockpits and rugged ground vehicles. APC specifies AMLCD's to be designed and manufactured, based on an exclusive relationship, with both LG.Philips LCD, in South Korea and BOE Hydis, in South Korea. This paper addresses the Fringe Field Switching (FFS) technology developed by BOE Hydis and APC's customization of this technology into both high end avionics display products as well as consumer display products. FFS technology optimizes all optical and electrical performance qualities into a single product. APC offers the high temperature FFS products for all applications.

Characterization of antigen-presenting cells from the porcine respiratory system.

PubMed

López-Robles, Guadalupe; Silva-Campa, Erika; Burgara-Estrella, Alexel; Hernández, Jesús

2015-06-01

Antigen-presenting cells (APCs) are strategically placed in all anatomic sites with high antigen exposure such as the respiratory system. The aim of this study was to evaluate phenotypic and functional properties of APCs from the lung (L-Cs), mediastinal lymph node (LN-Cs) and bronchoalveolar lavage cells (BAL-Cs). The APCs were first analyzed based on forward scatter and side scatter profiles and the selection of MHC-II(high)CD172a(+) cells (referred to as APCs); then the expression of CD1a, CD163, CD206, CD16 and CD11R3 was evaluated in the APCs. The results showed that CD1a, CD163 and CD206 were differentially expressed among L-Cs, LN-Cs and BAL-Cs, suggesting the phenotype MHC-II(high)CD172a(+)CD1a(low/-)CD163(low)CD206(-) for L-Cs and MHC-II(high)CD172a(+)CD1a(+)CD163(low/-)CD206(+) for LN-Cs. BAL-Cs were MHC-II(high)CD172a(+)CD1a(-)CD163(high)CD206(+/-). The functional characteristics of L-Cs and LN-Cs were different from those of BAL-Cs, confirming that L-Cs and LN-Cs resemble specialized APCs. In conclusion, we present the characterization of APCs from L-Cs, LN-Cs and BAL-Cs of the porcine respiratory system. Copyright © 2015 Elsevier Ltd. All rights reserved.

Disruption of estrogen receptor signaling enhances intestinal neoplasia in Apc(Min/+) mice.

PubMed

Cleveland, Alicia G; Oikarinen, Seija I; Bynoté, Kimberly K; Marttinen, Maija; Rafter, Joseph J; Gustafsson, Jan-Ake; Roy, Shyamal K; Pitot, Henry C; Korach, Kenneth S; Lubahn, Dennis B; Mutanen, Marja; Gould, Karen A

2009-09-01

Estrogen receptors (ERs) [ERalpha (Esr1) and ERbeta (Esr2)] are expressed in the human colon, but during the multistep process of colorectal carcinogenesis, expression of both ERalpha and ERbeta is lost, suggesting that loss of ER function might promote colorectal carcinogenesis. Through crosses between an ERalpha knockout and Apc(Min) mouse strains, we demonstrate that ERalpha deficiency is associated with a significant increase in intestinal tumor multiplicity, size and burden in Apc(Min/+) mice. Within the normal intestinal epithelium of Apc(Min/+) mice, ERalpha deficiency is associated with an accumulation of nuclear beta-catenin, an indicator of activation of the Wnt-beta-catenin-signaling pathway, which is known to play a critical role in intestinal cancers. Consistent with the hypothesis that ERalpha deficiency is associated with activation of Wnt-beta-catenin signaling, ERalpha deficiency in the intestinal epithelium of Apc(Min/+) mice also correlated with increased expression of Wnt-beta-catenin target genes. Through crosses between an ERbeta knockout and Apc(Min) mouse strains, we observed some evidence that ERbeta deficiency is associated with an increased incidence of colon tumors in Apc(Min/+) mice. This effect of ERbeta deficiency does not involve modulation of Wnt-beta-catenin signaling. Our studies suggest that ERalpha and ERbeta signaling modulate colorectal carcinogenesis, and ERalpha does so, at least in part, by regulating the activity of the Wnt-beta-catenin pathway.

Disruption of estrogen receptor signaling enhances intestinal neoplasia in ApcMin/+ mice

PubMed Central

Cleveland, Alicia G.; Oikarinen, Seija I.; Bynoté, Kimberly K.; Marttinen, Maija; Rafter, Joseph J.; Gustafsson, Jan-Åke; Roy, Shyamal K.; Pitot, Henry C.; Korach, Kenneth S.; Lubahn, Dennis B.; Mutanen, Marja; Gould, Karen A.

2009-01-01

Estrogen receptors (ERs) [ERα (Esr1) and ERβ (Esr2)] are expressed in the human colon, but during the multistep process of colorectal carcinogenesis, expression of both ERα and ERβ is lost, suggesting that loss of ER function might promote colorectal carcinogenesis. Through crosses between an ERα knockout and ApcMin mouse strains, we demonstrate that ERα deficiency is associated with a significant increase in intestinal tumor multiplicity, size and burden in ApcMin/+ mice. Within the normal intestinal epithelium of ApcMin/+ mice, ERα deficiency is associated with an accumulation of nuclear β-catenin, an indicator of activation of the Wnt–β-catenin-signaling pathway, which is known to play a critical role in intestinal cancers. Consistent with the hypothesis that ERα deficiency is associated with activation of Wnt–β-catenin signaling, ERα deficiency in the intestinal epithelium of ApcMin/+ mice also correlated with increased expression of Wnt–β-catenin target genes. Through crosses between an ERβ knockout and ApcMin mouse strains, we observed some evidence that ERβ deficiency is associated with an increased incidence of colon tumors in ApcMin/+ mice. This effect of ERβ deficiency does not involve modulation of Wnt–β-catenin signaling. Our studies suggest that ERα and ERβ signaling modulate colorectal carcinogenesis, and ERα does so, at least in part, by regulating the activity of the Wnt–β-catenin pathway. PMID:19520794

Association between aberrant APC promoter methylation and breast cancer pathogenesis: a meta-analysis of 35 observational studies.

PubMed

Zhou, Dan; Tang, Weiwei; Wang, Wenyi; Pan, Xiaoyan; An, Han-Xiang; Zhang, Yun

2016-01-01

Background. Adenomatous polyposis coli (APC) is widely known as an antagonist of the Wnt signaling pathway via the inactivation of β-catenin. An increasing number of studies have reported that APC methylation contributes to the predisposition to breast cancer (BC). However, recent studies have yielded conflicting results. Methods. Herein, we systematically carried out a meta-analysis to assess the correlation between APC methylation and BC risk. Based on searches of the Cochrane Library, PubMed, Web of Science and Embase databases, the odds ratio (OR) with 95% confidence interval (CI) values were pooled and summarized. Results. A total of 31 articles involving 35 observational studies with 2,483 cases and 1,218 controls met the inclusion criteria. The results demonstrated that the frequency of APC methylation was significantly higher in BC cases than controls under a random effect model (OR = 8.92, 95% CI [5.12-15.52]). Subgroup analysis further confirmed the reliable results, regardless of the sample types detected, methylation detection methods applied and different regions included. Interestingly, our results also showed that the frequency of APC methylation was significantly lower in early-stage BC patients than late-stage ones (OR = 0.62, 95% CI [0.42-0.93]). Conclusion. APC methylation might play an indispensable role in the pathogenesis of BC and could be regarded as a potential biomarker for the diagnosis of BC.

APC and Smad7 link TGFβ type I receptors to the microtubule system to promote cell migration

PubMed Central

Ekman, Maria; Mu, Yabing; Lee, So Young; Edlund, Sofia; Kozakai, Takaharu; Thakur, Noopur; Tran, Hoanh; Qian, Jiang; Groeden, Joanna; Heldin, Carl-Henrik; Landström, Maréne

2012-01-01

Cell migration occurs by activation of complex regulatory pathways that are spatially and temporally integrated in response to extracellular cues. Binding of adenomatous polyposis coli (APC) to the microtubule plus ends in polarized cells is regulated by glycogen synthase kinase 3β (GSK-3β). This event is crucial for establishment of cell polarity during directional migration. However, the role of APC for cellular extension in response to extracellular signals is less clear. Smad7 is a direct target gene for transforming growth factor-β (TGFβ) and is known to inhibit various TGFβ-induced responses. Here we report a new function for Smad7. We show that Smad7 and p38 mitogen–activated protein kinase together regulate the expression of APC and cell migration in prostate cancer cells in response to TGFβ stimulation. In addition, Smad7 forms a complex with APC and acts as an adaptor protein for p38 and GSK-3β kinases to facilitate local TGFβ/p38–dependent inactivation of GSK-3β, accumulation of β-catenin, and recruitment of APC to the microtubule plus end in the leading edge of migrating prostate cancer cells. Moreover, the Smad7–APC complex links the TGFβ type I receptor to the microtubule system to regulate directed cellular extension and migratory responses evoked by TGFβ. PMID:22496417

Long-term effect of argon plasma coagulation (APC) in the treatment of gastric antral vascular ectasia (GAVE).

PubMed

Naga, Mazen; Esmat, Serag; Naguib, Mohamed; Sedrak, Heba

2011-03-01

Gastric antral vascular ectasia (GAVE) is a distinct vascular abnormality, mainly involving the gastric antrum. It is a rare but well-known cause of occult gastrointestinal bleeding. Various endoscopic treatment modalities have been tried in this condition. The aim of the study is to show the long-term effect of argon plasma coagulation (APC) on GAVE. Twenty-nine patients with endoscopically proved GAVE were enrolled in the study. Clinical assessment of GAVE patients, haemoglobin (Hb) level and transfused blood units were recorded after APC using 60-80-W power setting. A second session was done 1month after the therapeutic procedure to ensure complete ablation of all lesions. The documented Hb levels and number of blood units transfused 3months after APC were recorded. At endoscopy, all patients had the classic type of GAVE. The mean Hb level increased from 7.5±1.7gdl(-1) before APC to 10.2±0.8gdl(-1) after APC (p value <0.001). The transfusion requirements significantly decreased to 0.2±0.5units/patient (p value <0.001). Endoscopic APC is a safe, effective and inexpensive modality in treating GAVE and could be an alternative to the currently available endoscopic methods. Copyright © 2011 Arab Journal of Gastroenterology. Published by Elsevier Ltd. All rights reserved.

Antibodies associated with heparin-induced thrombocytopenia (HIT) inhibit activated protein C generation: new insights into the prothrombotic nature of HIT.

PubMed

Kowalska, M Anna; Krishnaswamy, Sriram; Rauova, Lubica; Zhai, Li; Hayes, Vincent; Amirikian, Karine; Esko, Jeffrey D; Bougie, Daniel W; Aster, Richard H; Cines, Douglas B; Poncz, Mortimer

2011-09-08

Heparin-induced thrombocytopenia (HIT) is caused by antibodies that recognize complexes between platelet factor 4 (PF4) and heparin or glycosaminoglycan side chains. These antibodies can lead to a limb- and life-threatening prothrombotic state. We now show that HIT antibodies are able to inhibit generation of activated protein C (aPC) by thrombin/thrombomodulin (IIa/TM) in the presence of PF4. Tetrameric PF4 potentiates aPC generation by formation of complexes with chondroitin sulfate (CS) on TM. Formation of these complexes occurs at a specific molar ratio of PF4 to glycosaminoglycan. This observation and the finding that the effect of heparin on aPC generation depends on the concentration of PF4 suggest similarity between PF4/CS complexes and those that bind HIT antibodies. HIT antibodies reduced the ability of PF4 to augment aPC formation. Cationic protamine sulfate, which forms similar complexes with heparin, also enhanced aPC generation, but its activity was not blocked by HIT antibodies. Our studies provide evidence that complexes formed between PF4 and TM's CS may play a physiologic role in potentiating aPC generation. Recognition of these complexes by HIT antibodies reverses the PF4-dependent enhancement in aPC generation and may contribute to the prothrombotic nature of HIT.

REMOVAL OF ARSENIC IN DRINKING WATER: ARS CFU-50 APC ELECTROFLOCCULATION AND FILTRATION WATER TREATMENT SYSTEM

EPA Science Inventory

ETV testing of the ARS CFU-50 APC Electroflocculation and Filtration Water Treatment System (ARS CFU-50 APC) for arsenic removal was conducted at the Town of Bernalillo Well #3 site from April 18 through May 2, 2006. The source water was chlorinated groundwater from two supply w...

40 CFR 52.781 - Rules and regulations.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) A part of the second sentence in section 3, APC-17, which states “Where there is a violation or... pollution control equipment shall comply with th (c)-(d) [Reserved] (e) Section 2(d) of APC-20, Fugitive...) Subsections 3(b)(3) and 3(b)(5) of APC-2 (May 18, 1977) are disapproved because they are unenforceable within...

A rising trend in the incidence of advanced gastric cancer in young Hispanic men.

PubMed

Merchant, Shaila J; Kim, Joseph; Choi, Audrey H; Sun, Virginia; Chao, Joseph; Nelson, Rebecca

2017-03-01

Although the incidence of gastric cancer has been decreasing, recent reports suggest an increased rate in select populations. We sought to evaluate trends in gastric cancer incidence to identify high-risk populations. Gastric cancer incidence rates from 1992 to 2011 were computed with use of the Surveillance, Epidemiology, and End Results (SEER) registry. We evaluated trends in incidence rates by calculating the annual percent change (APC) across three age groups (20-49 years, 50-64 years, and 65 years or older) and four racial/ethnic groups (Hispanics, non-Hispanic whites, blacks, and Asian/Pacific Islanders). We identified 41,428 patients with gastric cancer. For the entire cohort during the study period, the APC was decreased. When patients were grouped according to sex, the APC was flat or decreased in women regardless of age or race/ethnicity. The APC was also flat or decreased for all men except young Hispanic men (20-49 years), who had an increased APC of nearly 1.6 % (1.55 %, 95 % confidence interval 0.26-2.86 %). Furthermore, young Hispanic men were the only group to have increased incidence of stage IV disease (APC 4.34 %, 95 % confidence interval 2.76-5.94 %) and poorly differentiated tumors (APC 2.08 %, 95 % confidence interval 0.48-3.70 %). The APC of the incidence of gastric cancer in young Hispanic men places it among the top cancers with rising incidence in the USA. This is concomitant with increased incidence of advanced disease at presentation. This major public health concern warrants additional research to determine the cause of the increasing incidence in this group.

Evolution of the use of noninvasive mechanical ventilation in chronic obstructive pulmonary disease in a Spanish region, 1997-2010.

PubMed

Carpe-Carpe, Bienvenida; Hernando-Arizaleta, Lauro; Ibáñez-Pérez, M Carmen; Palomar-Rodríguez, Joaquín A; Esquinas-Rodríguez, Antonio M

2013-08-01

Noninvasive mechanical ventilation (NIV) appeared in the 1980s as an alternative to invasive mechanical ventilation (IMV) in patients with acute respiratory failure. We evaluated the introduction of NIV and the results in patients with acute exacerbation of chronic obstructive pulmonary disease in the Region of Murcia (Spain). A retrospective observational study based on the minimum basic hospital discharge data of all patients hospitalised for this pathology in all public hospitals in the region between 1997 and 2010. We performed a time trend analysis on hospital attendance, the use of each ventilatory intervention and hospital mortality through joinpoint regression. We identified 30.027 hospital discharges. Joinpoint analysis: downward trend in attendance (annual percentage change [APC]=-3.4, 95% CI: - 4.8; -2.0, P <.05) and in the group without ventilatory intervention (APC=-4.2%, -5.6; -2.8, P <.05); upward trend in the use of NIV (APC=16.4, 12.0; 20. 9, P <.05), and downward trend that was not statistically significant in IMV (APC=-4.5%, -10.3; 1.7). We observed an upward trend without statistical significance in overall mortality (APC=0.5, -1.3; 2.4) and in the group without intervention (APC=0.1, -1.6; 1.9); downward trend with statistical significance in the NIV group (APC=-7.1, -11.7; -2.2, P <.05) and not statistically significant in the IMV group (APC=-0,8, -6, 1; 4.8). The mean stay did not change substantially. The introduction of NIV has reduced the group of patients not receiving assisted ventilation. No improvement in results was found in terms of mortality or length of stay. Copyright © 2012 SEPAR. Published by Elsevier Espana. All rights reserved.

Antigen presenting cells (APCs) from thermally injured and/or septic rats modulate CD4+ T cell responses of naive rat.

PubMed

Fazal, Nadeem; Raziuddin, Syed; Khan, Mehdi; Al-Ghoul, Walid M

2006-01-01

Regulation of immune response is marked by complex interactions among the cells that recognize and present antigens. Antigen presenting cells (APCs), the antigen presenting cell component of the innate immune response plays an important role in effector CD4+ T cell response. Thermal injury and/or superimposed sepsis in rats' leads to suppressed CD4+ T cell functions. We investigated modulations of CD4+ T cell function by APCs (purified non-T cells) from thermally injured and/or septic rats. Rats were subjected to 30% total body surface area scald burn or exposed to 37 degrees C water (Sham burn) and sepsis was induced by cecal-ligation and puncture (CLP) method. At day 3 post-injury animals were sacrificed and CD4+ T cells and APCs from mesenteric lymph nodes (MLN) were obtained using magnetic microbead isolation procedure. APCs from injured rats were co-cultured with sham rat MLN CD4+ T cells and proliferative responses (thymidine incorporation), phenotypic changes (Flow cytometry), IL-2 production (ELISA) and CTLA-4 mRNA (RT-PCR) were determined in naive rat CD4+ T cells. The data indicate that APCs from thermally injured and/or septic rats when co-cultured with CD4+ T cells suppressed CD4+ T cell effector functions. This lack of CD4+ T cell activation was accompanied with altered co-stimulatory molecules, i.e., CD28 and/or CTLA-4 (CD152). In conclusion, our studies indicated that defective APCs from thermally injured and/or septic rats modulate CD4+ T cell functions via changes in co-stimulatory molecules expressed on naive CD4+ T cells. This altered APC: CD4+ T cell interaction leads to suppressed CD4+ T cell activation of healthy animals.

Efficacy and safety of Hybrid-APC for the ablation of Barrett's esophagus.

PubMed

Manner, Hendrik; May, Andrea; Kouti, Ioanna; Pech, Oliver; Vieth, Michael; Ell, Christian

2016-04-01

After thermal ablation of Barrett's esophagus (BE), stricture formation is reported in 5 to over 10% of patients. The question arises whether submucosal fluid injection prior to ablation may lower the risk of stricture formation. The aim of the present study was to evaluate the efficacy and safety of the new technique of Hybrid-APC which combines submucosal injection with APC. Patients who had a residual BE segment of at least 1 cm after endoscopic resection of early Barrett's neoplasia underwent thermal ablation of BE by Hybrid-APC. Prior to thermal ablation, submucosal injection of sodium chloride 0.9% was carried out using a flexible water-jet probe (Erbejet 2; Erbe Elektromedizin, Tuebingen, Germany). Check-up upper GI endoscopy was carried out 3 months after macroscopically complete ablation including biopsies from the neo-Z-line and the former BE segment, and recording of stricture formation. From May 2011 to November 2012, a total of 60 patients (pt) were included in the study [55 pt male (92%); mean age 62 ± 9 years, range 42-79]. Ten patients were excluded from the study. In the remaining 50 pt, Hybrid-APC ablation and check-up endoscopy at 3 months were carried out. Forty-eight out of 50 pt (96%; ITT: 49/60, 82%) achieved macroscopically complete remission after a median of 3.5 APC sessions [SD 2.4; range 1-10]. Freedom from BE was histopathologically observed in 39/50 patients (78%). There was one treatment-related stricture (2%). Minor adverse events of Hybrid-APC were observed in 11 patients (22%). According to this pilot series, Hybrid-APC was effective and safe for BE ablation in a tertiary referral center. The rate of stricture formation was only 2%. Further studies are required to confirm the present results. DRKS00003369.

APC promoter is frequently methylated in pancreatic juice of patients with pancreatic carcinomas or periampullary tumors.

PubMed

Ginesta, Mireia M; Diaz-Riascos, Zamira Vanessa; Busquets, Juli; Pelaez, Núria; Serrano, Teresa; Peinado, Miquel Àngel; Jorba, Rosa; García-Borobia, Francisco Javier; Capella, Gabriel; Fabregat, Joan

2016-09-01

Early detection of pancreatic and periampullary neoplasms is critical to improve their clinical outcome. The present authors previously demonstrated that DNA hypermethylation of adenomatous polyposis coli (APC), histamine receptor H2 (HRH2), cadherin 13 (CDH13), secreted protein acidic and cysteine rich (SPARC) and engrailed-1 (EN-1) promoters is frequently detected in pancreatic tumor cells. The aim of the present study was to assess their prevalence in pancreatic juice of carcinomas of the pancreas and periampullary area. A total of 135 pancreatic juices obtained from 85 pancreatic cancer (PC), 26 ampullary carcinoma (AC), 10 intraductal papillary mucinous neoplasm (IPMN) and 14 chronic pancreatitis (CP) patients were analyzed. The methylation status of the APC, HRH2, CDH13, SPARC and EN-1 promoters was analyzed using methylation specific-melting curve analysis (MS-MCA). Kirsten rat sarcoma viral oncogene homolog (KRAS) mutations were also tested with allele-specific quantitative polymerase chain reaction amplification. Out of the 5 promoters analyzed, APC (71%) and HRH2 (65%) were the most frequently methylated in PC juice. APC methylation was also detected at a high frequency in AC (76%) and IPMN (80%), but only occasionally observed in CP (7%). APC methylation had a high sensitivity (71-80%) for all types of cancer analyzed. The panel (where a sample scored as positive when ≥2 markers were methylated) did not outperform APC as a single marker. Finally, KRAS detection in pancreatic juice offered a lower sensitivity (50%) and specificity (71%) for detection of any cancer. APC hypermethylation in pancreatic juice, as assessed by MS-MCA, is a frequent event of potential clinical usefulness in the diagnosis of pancreatic and periampullary neoplasms.

Promoter methylation of APC and RAR-β genes as prognostic markers in non-small cell lung cancer (NSCLC).

PubMed

Feng, Hongxiang; Zhang, Zhenrong; Qing, Xin; Wang, Xiaowei; Liang, Chaoyang; Liu, Deruo

2016-02-01

Aberrant promoter hypermethylations of tumor suppressor genes are promising markers for lung cancer diagnosis and prognosis. The purpose of this study was to determine methylation status at APC and RAR-β promoters in primary NSCLC, and whether they have any relationship with survival. APC and RAR-β promoter methylation status were determined in 41 NSCLC patients using methylation specific PCR. APC promoter methylation was detectable in 9 (22.0%) tumor samples and 6 (14.6%) corresponding non-tumor samples (P=0.391). RAR-β promoter methylation was detectable in 13 (31.7%) tumor samples and 4 (9.8%) corresponding non-tumor samples (P=0.049) in the NSCLC patients. APC promoter methylation was found to be associated with T stage (P=0.046) and nodal status (P=0.019) in non-tumor samples, and with smoking (P=0.004) in tumor samples. RAR-β promoter methylation was found associated with age (P=0.031) in non-tumor samples and with primary tumor site in tumor samples. Patients with APC promoter methylation in tumor samples showed significantly longer survival than patients without it (Log-rank P=0.014). In a multivariate analysis of prognostic factors, APC methylation in tumor samples was an independent prognostic factor (P=0.012), as were N1 positive lymph node number (P=0.025) and N2 positive lymph node number (P=0.06). Our study shows that RAR-β methylation detected in lung tissue may be used as a predictive marker for NSCLC diagnosis and that APC methylation in tumor sample may be a useful marker for superior survival in NSCLC patients. Copyright © 2015. Published by Elsevier Inc.

Identification of the APC/C co-factor FZR1 as a novel therapeutic target for multiple myeloma.

PubMed

Crawford, Lisa J; Anderson, Gordon; Johnston, Cliona K; Irvine, Alexandra E

2016-10-25

Multiple Myeloma (MM) is a haematological neoplasm characterised by the clonal proliferation of malignant plasma cells in the bone marrow. The success of proteasome inhibitors in the treatment of MM has highlighted the importance of the ubiquitin proteasome system (UPS) in the pathogenesis of this disease. In this study, we analysed gene expression of UPS components to identify novel therapeutic targets within this pathway in MM. Here we demonstrate how this approach identified previously validated and novel therapeutic targets. In addition we show that FZR1 (Fzr), a cofactor of the multi-subunit E3 ligase complex anaphase-promoting complex/cyclosome (APC/C), represents a novel therapeutic target in myeloma. The APC/C associates independently with two cofactors, Fzr and Cdc20, to control cell cycle progression. We found high levels of FZR1 in MM primary cells and cell lines and demonstrate that expression is further increased on adhesion to bone marrow stromal cells (BMSCs). Specific knockdown of either FZR1 or CDC20 reduced viability and induced growth arrest of MM cell lines, and resulted in accumulation of APC/CFzr substrate Topoisomerase IIα (TOPIIα) or APC/CCdc20 substrate Cyclin B. Similar effects were observed following treatment with proTAME, an inhibitor of both APC/CFzr and APC/CCdc20. Combinations of proTAME with topoisomerase inhibitors, etoposide and doxorubicin, significantly increased cell death in MM cell lines and primary cells, particularly if TOPIIα levels were first increased through pre-treatment with proTAME. Similarly, combinations of proTAME with the microtubule inhibitor vincristine resulted in enhanced cell death. This study demonstrates the potential of targeting the APC/C and its cofactors as a therapeutic approach in MM.

Induction of endoplasmic reticulum stress by deletion of Grp78 depletes Apc mutant intestinal epithelial stem cells.

PubMed

van Lidth de Jeude, J F; Meijer, B J; Wielenga, M C B; Spaan, C N; Baan, B; Rosekrans, S L; Meisner, S; Shen, Y H; Lee, A S; Paton, J C; Paton, A W; Muncan, V; van den Brink, G R; Heijmans, J

2017-06-15

Intestinal epithelial stem cells are highly sensitive to differentiation induced by endoplasmic reticulum (ER) stress. Colorectal cancer develops from mutated intestinal epithelial stem cells. The most frequent initiating mutation occurs in Apc, which results in hyperactivated Wnt signalling. This causes hyperproliferation and reduced sensitivity to chemotherapy, but whether these mutated stem cells are sensitive to ER stress induced differentiation remains unknown. Here we examined this by generating mice in which both Apc and ER stress repressor chaperone Grp78 can be conditionally deleted from the intestinal epithelium. For molecular studies, we used intestinal organoids derived from these mice. Homozygous loss of Apc alone resulted in crypt elongation, activation of the Wnt signature and accumulation of intestinal epithelial stem cells, as expected. This phenotype was however completely rescued on activation of ER stress by additional deletion of Grp78. In these Apc-Grp78 double mutant animals, stem cells were rapidly lost and repopulation occurred by non-mutant cells that had escaped recombination, suggesting that Apc-Grp78 double mutant stem cells had lost self-renewal capacity. Although in Apc-Grp78 double mutant mice the Wnt signature was lost, these intestines exhibited ubiquitous epithelial presence of nuclear β-catenin. This suggests that ER stress interferes with Wnt signalling downstream of nuclear β-catenin. In conclusion, our findings indicate that ER stress signalling results in loss of Apc mutated intestinal epithelial stem cells by interference with the Wnt signature. In contrast to many known inhibitors of Wnt signalling, ER stress acts downstream of β-catenin. Therefore, ER stress poses a promising target in colorectal cancers, which develop as a result of Wnt activating mutations.

Evaluation of combined argon plasma coagulation and Savary Bougienage for the relief of anastomotic-stenosis after esophageal squamous cancer surgery.

PubMed

Jia, Ruinuo; Guo, Ruifeng; Liu, Gang; Yuan, Xiang; Dong, Caihong; Shan, Tanyou; Yuan, Xiaozhi; Zhang, Yi; Tai, Edmund Wing To; Feng, Xiaoshan; Gao, Shegan

2014-01-01

Several endoscopic dilation techniques have been reported for treatment of anastomotic-stenosis of esophageal cancer, but the high incidence of dysphagia has remained unchanged. The aim of this study was to compare the effect of Argon Plasma Coagulation (APC) combined with Savary Bougienage (SB) compared to APC alone or SB alone for anastomotic-stenosis after radical operation for squamous cell carcinoma of the esophagus. Patients with anastomotic-stenosis that was diagnosed for the first time following esophageal squamous cell carcinoma resection surgery were randomly assigned to undergo APC combined with SB, APC alone, or SB alone. Primary endpoints were the dysphagia-free survival (DFS defined as the time from first dilatation of effectively relieved dysphagia to dysphagia relapse expressed in days) after 6 months of follow up. A total of 90 patients from the Cancer Institute, First Affiliated Hospital of Henan University of Science and Technology were entered into the study (APC group, n = 30, SB group, n = 30, combination group [APC combined with SB], n = 30). Primary endpoints: 6 months after treatment, DFS of combination group (115.63 days; 95% CI, 105.31-125.95) was significantly longer than the APC alone group (39.53 days; 95% CI, 35.95-43.11, p = 0.000) and the SB alone group (16.93 days; 95% CI, 15.01-18.84, p = 0.000). No severe complications occurred within the three treatment groups. APC combined with SB was a safe and well-tolerated method for relieving dysphagia of esophageal squamous cell cancer patients with anastomotic-stenosis. (Registered with randomized controlled trials, ChiCRT, registration number ChiCTR-TRC-13003757.) © 2015 S. Karger AG, Basel.

Targeted Modification of Mitochondrial ROS Production Converts High Glucose-Induced Cytotoxicity to Cytoprotection: Effects on Anesthetic Preconditioning.

PubMed

Sedlic, Filip; Muravyeva, Maria Y; Sepac, Ana; Sedlic, Marija; Williams, Anna Marie; Yang, Meiying; Bai, Xiaowen; Bosnjak, Zeljko J

2017-01-01

Contradictory reports on the effects of diabetes and hyperglycemia on myocardial infarction range from cytotoxicity to cytoprotection. The study was designed to investigate acute effects of high glucose-driven changes in mitochondrial metabolism and osmolarity on adaptive mechanisms and resistance to oxidative stress of isolated rat cardiomyocytes. We examined the effects of high glucose on several parameters of mitochondrial bioenergetics, including changes in oxygen consumption, mitochondrial membrane potential, and NAD(P)H fluorometry. Effects of high glucose on the endogenous cytoprotective mechanisms elicited by anesthetic preconditioning (APC) and the mediators of cell injury were also tested. These experiments included real-time measurements of reactive oxygen species (ROS) production and mitochondrial permeability transition pore (mPTP) opening in single cells by laser scanning fluorescence confocal microscopy, and cell survival assay. High glucose rapidly enhanced mitochondrial energy metabolism, observed by increase in NAD(P)H fluorescence intensity, oxygen consumption, and mitochondrial membrane potential. This substantially elevated production of ROS, accelerated opening of the mPTP, and decreased survival of cells exposed to oxidative stress. Abrogation of high glucose-induced mitochondrial hyperpolarization with 2,4 dinitrophenol (DNP) significantly, but not completely, attenuated ROS production to a level similar to hyperosmotic mannitol control. DNP treatment reversed high glucose-induced cytotoxicity to cytoprotection. Hyperosmotic mannitol treatment also induced cytoprotection. High glucose abrogated APC-induced mitochondrial depolarization, delay in mPTP opening and cytoprotection. In conclusion, high glucose-induced mitochondrial hyperpolarization abolishes APC and augments cell injury. Attenuation of high glucose-induced ROS production by eliminating mitochondrial hyperpolarization protects cardiomyocytes. J. Cell. Physiol. 232: 216-224, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Expression of tolerance associated gene-1, a mitochondrial protein inhibiting T cell activation, can be used to predict response to immune modulating therapies.

PubMed

Keeren, Kathrin; Friedrich, Markus; Gebuhr, Inga; Philipp, Sandra; Sabat, Robert; Sterry, Wolfram; Brandt, Christine; Meisel, Christian; Grütz, Gerald; Volk, Hans-Dieter; Sawitzki, Birgit

2009-09-15

Immune modulating therapies gain increasing importance in treatment of patients with autoimmune diseases such as psoriasis. None of the currently applied biologics achieves significant clinical improvement in all treated patients. Because the therapy with biologics is cost intensive and sometimes associated with side effects, noninvasive diagnostic tools for early prediction of responders are of major interest. We studied the effects of Alefacept (LFA3Ig), an approved drug for treatment of psoriasis, on leukocytes in vitro and in vivo to identify gene markers predictive for treatment response and to further investigate its molecular mechanisms of action. In an open-label study, 20 psoriasis patients were treated weekly with 15 mg Alefacept over 12 wk. We demonstrate that transcription of the tolerance-associated gene (TOAG-1) is significantly up-regulated whereas receptor for hyaluronic acid mediated migration (RHAMM) transcription is down-regulated in PBMCs of responding patients before clinical improvement. TOAG-1 is exclusively localized within mitochondria. Overexpression of TOAG-1 in murine T cells leads to increased susceptibility to apoptosis. Addition of Alefacept to stimulated human T cells in vitro resulted in reduced frequencies of activated CD137(+) cells, increased TOAG-1 but reduced RHAMM expression. This was accompanied by reduced proliferation and enhanced apoptosis. Inhibition of proliferation was dependent on enhanced PDL1 expression of APCs. Thus, peripheral changes of TOAG-1 and RHAMM expression can be used to predict clinical response to Alefacept treatment in psoriasis patients. In the presence of APCs Alefacept can inhibit T cell activation and survival by increasing expression of TOAG-1 on T cells and PDL1 on APCs.

T-cell brain infiltration and immature antigen-presenting cells in transgenic models of Alzheimer's disease-like cerebral amyloidosis.

PubMed

Ferretti, M T; Merlini, M; Späni, C; Gericke, C; Schweizer, N; Enzmann, G; Engelhardt, B; Kulic, L; Suter, T; Nitsch, R M

2016-05-01

Cerebral beta-amyloidosis, one of the pathological hallmarks of Alzheimer's disease (AD), elicits a well-characterised, microglia-mediated local innate immune response. In contrast, it is not clear whether cells of the adaptive immune system, in particular T-cells, react to cerebral amyloidosis in AD. Even though parenchymal T-cells have been described in post-mortem brains of AD patients, it is not known whether infiltrating T-cells are specifically recruited to the extracellular deposits of beta-amyloid, and whether they are locally activated into proliferating, effector cells upon interaction with antigen-presenting cells (APCs). To address these issues we have analysed by confocal microscopy and flow-cytometry the localisation and activation status of both T-cells and APCs in transgenic (tg) mice models of AD-like cerebral amyloidosis. Increased numbers of infiltrating T-cells were found in amyloid-burdened brain regions of tg mice, with concomitant up-regulation of endothelial adhesion molecules ICAM-1 and VCAM-1, compared to non-tg littermates. The infiltrating T-cells in tg brains did not co-localise with amyloid plaques, produced less interferon-gamma than those in controls and did not proliferate locally. Bona-fide dendritic cells were virtually absent from the brain parenchyma of both non-tg and tg mice, and APCs from tg brains showed an immature phenotype, with accumulation of MHC-II in intracellular compartments. These results indicate that cerebral amyloidosis promotes T-cell infiltration but interferes with local antigen presentation and T-cell activation. The inability of the brain immune surveillance to orchestrate a protective immune response to amyloid-beta peptide might contribute to the accumulation of amyloid in the progression of the disease. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Choice and Design of Adjuvants for Parenteral and Mucosal Vaccines

PubMed Central

Savelkoul, Huub F. J.; Ferro, Valerie A.; Strioga, Marius M.; Schijns, Virgil E. J. C.

2015-01-01

The existence of pathogens that escape recognition by specific vaccines, the need to improve existing vaccines and the increased availability of therapeutic (non-infectious disease) vaccines necessitate the rational development of novel vaccine concepts based on the induction of protective cell-mediated immune responses. For naive T-cell activation, several signals resulting from innate and adaptive interactions need to be integrated, and adjuvants may interfere with some or all of these signals. Adjuvants, for example, are used to promote the immunogenicity of antigens in vaccines, by inducing a pro-inflammatory environment that enables the recruitment and promotion of the infiltration of phagocytic cells, particularly antigen-presenting cells (APC), to the injection site. Adjuvants can enhance antigen presentation, induce cytokine expression, activate APC and modulate more downstream adaptive immune reactions (vaccine delivery systems, facilitating immune Signal 1). In addition, adjuvants can act as immunopotentiators (facilitating Signals 2 and 3) exhibiting immune stimulatory effects during antigen presentation by inducing the expression of co-stimulatory molecules on APC. Together, these signals determine the strength of activation of specific T-cells, thereby also influencing the quality of the downstream T helper cytokine profiles and the differentiation of antigen-specific T helper populations (Signal 3). New adjuvants should also target specific (innate) immune cells in order to facilitate proper activation of downstream adaptive immune responses and homing (Signal 4). It is desirable that these adjuvants should be able to exert such responses in the context of mucosal administered vaccines. This review focuses on the understanding of the potential working mechanisms of the most well-known classes of adjuvants to be used effectively in vaccines. PMID:26344951

Steady State Dendritic Cells Present Parenchymal Self-Antigen and Contribute to, but Are Not Essential for, Tolerization of Naive and Th1 Effector CD4 Cells1

PubMed Central

Hagymasi, Adam T.; Slaiby, Aaron M.; Mihalyo, Marianne A.; Qui, Harry Z.; Zammit, David J.; Lefrançois, Leo; Adler, Adam J.

2010-01-01

Bone marrow-derived APC are critical for both priming effector/memory T cell responses to pathogens and inducing peripheral tolerance in self-reactive T cells. In particular, dendritic cells (DC) can acquire peripheral self-Ags under steady state conditions and are thought to present them to cognate T cells in a default tolerogenic manner, whereas exposure to pathogen-associated inflammatory mediators during the acquisition of pathogen-derived Ags appears to reprogram DCs to prime effector and memory T cell function. Recent studies have confirmed the critical role of DCs in priming CD8 cell effector responses to certain pathogens, although the necessity of steady state DCs in programming T cell tolerance to peripheral self-Ags has not been directly tested. In the current study, the role of steady state DCs in programming self-reactive CD4 cell peripheral tolerance was assessed by combining the CD11c-diphtheria toxin receptor transgenic system, in which DC can be depleted via treatment with diphtheria toxin, with a TCR-transgenic adoptive transfer system in which either naive or Th1 effector CD4 cells are induced to undergo tolerization after exposure to cognate parenchymally derived self-Ag. Although steady state DCs present parenchymal self-Ag and contribute to the tolerization of cognate naive and Th1 effector CD4 cells, they are not essential, indicating the involvement of a non-DC tolerogenic APC population(s). Tolerogenic APCs, however, do not require the cooperation of CD4+CD25+ regulatory T cells. Similarly, DC were required for maximal priming of naive CD4 cells to vaccinia viral-Ag, but priming could still occur in the absence of DC. PMID:17641018

APC implementation in Chandra Asri - ethylene plant

NASA Astrophysics Data System (ADS)

Sidiq, Mochamad; Mustofa, Ali

2017-05-01

Nowadays, the modern process plants are continuously improved for maximizing production, Optimization of the energy and raw material and reducing the risk. Due to many disturbances appearance between the process units, hence, the failure of one unit might have a bad effect on the overall productivity. Ethylene Plant have significant opportunities for using Advanced Process Control (APC) technologies to improve operation stability, push closer to quality or equipment limit, and improve the capability of process units to handle disturbances. APC implementation had considered a best answer for solving multivariable control problem. PT. Chandra Asri Petrochemical, Tbk (CAP) operates a large naphtha cracker complex at Cilegon, Indonesia. To optimize the plant operation and to enhance the benefit, Chandra Asri has been decided to implement Advance Process Control (APC) for ethylene plant. The APC implementation technology scopes at CAP are as follows: 1. Hot Section : Furnaces, Quench Tower 2. Cold Section : Demethanizer, Deethanizer, Acetylene Converter, Ethylene Fractionator, Depropanizer, Propylene Fractionator, Debutanizer

Analysis of mortality data from the former USSR: age-period-cohort analysis.

PubMed

Willekens, F; Scherbov, S

1992-01-01

The objective of this article is to review research on age-period-cohort (APC) analysis of mortality and to trace the effects of contemporary and historical factors on mortality change in the former USSR. Several events in USSR history have exerted a lasting influence on its people. These influences may be captured by an APC model in which the period effects measure the impact of contemporary factors and the cohort effects the past history of individuals which cannot be attributed to age or stage in the life cycle. APC models are extensively applied in the study of mortality. This article presents the statistical theory of the APC models and shows that they belong to the family of generalized linear models. The parameters of the APC model may therefore be estimated by any package of loglinear analysis that allows for hybrid loglinear models.

Smad4-Mediated Signaling Inhibits Intestinal Neoplasia by Inhibiting Expression of β-Catenin

PubMed Central

Freeman, Tanner J.; Smith, J. Joshua; Chen, Xi; Washington, M. Kay; Roland, Joseph T.; Means, Anna L.; Eschrich, Steven A.; Yeatman, Timothy J.; Deane, Natasha G.; Beauchamp, R. Daniel

2012-01-01

Background & Aims Mutational inactivation of APC is an early event in colorectal cancer (CRC) progression that affects the stability and increases the activity of β-catenin, a mediator of Wnt signaling. CRC progression also involves inactivation of signaling via transforming growth factor (TGF)β and bone morphenogenic protein (BMP), which are tumor suppressors. However, the interactions between these pathways are not clear. We investigated the effects of loss of the transcription factor Smad4 loss on levels of β-catenin mRNA and Wnt signaling. Methods We used microarray analysis to associate levels of Smad4 and β-catenin mRNA in colorectal tumor samples from 250 patients. We performed oligonucleotide-mediated knockdown of Smad4 in human embryonic kidney (HEK293T) and in HCT116 colon cancer cells and transgenically expressed Smad4 in SW480 colon cancer cells. We analyzed adenomas from (APCΔ1638/+) and (APCΔ1638/+)x(K19CreERT2Smad4lox/lox) mice using laser-capture microdissection. Results In human CRC samples, reduced levels of Smad4 correlated with increased levels of β-catenin mRNA. In Smad4-depleted cell lines, levels of β-catenin mRNA and Wnt signaling increased. Inhibition of BMP or depletion of Smad4 in HEK293T cells increased binding of RNA polymerase II to the β-catenin gene. Expression of Smad4 in SW480 cells reduced Wnt signaling and levels of β-catenin mRNA. In mice with heterozygous disruption of Apc(APCΔ1638/+), Smad4-deficient intestinal adenomas had increased levels of β-catenin mRNA and expression of Wnt target genes, compared with adenomas from APCΔ1638/+mice that expressed Smad4. Conclusions Transcription of β-catenin is inhibited by BMP signaling to Smad4. These findings provide important information about the interaction among TGF-β, BMP, and Wnt signaling pathways in CRC progression. PMID:22115830

CD4 Receptor is a Key Determinant of Divergent HIV-1 Sensing by Plasmacytoid Dendritic Cells

PubMed Central

Wilen, Craig; Gopal, Ramya; Huq, Rumana; Wu, Vernon; Sunseri, Nicole; Bhardwaj, Nina

2016-01-01

Plasmacytoid dendritic cells (pDC) are innate immune cells that sense viral nucleic acids through endosomal Toll-like receptor (TLR) 7/9 to produce type I interferon (IFN) and to differentiate into potent antigen presenting cells (APC). Engagement of TLR7/9 in early endosomes appears to trigger the IRF7 pathway for IFN production whereas engagement in lysosomes seems to trigger the NF-κB pathway for maturation into APC. We showed previously that HIV-1 (HIV) localizes predominantly to early endosomes, not lysosomes, and mainly stimulate IRF7 rather than NF-κB signaling pathways in pDC. This divergent signaling may contribute to disease progression through production of pro-apoptotic and pro-inflammatory IFN and inadequate maturation of pDCs. We now demonstrate that HIV virions may be re-directed to lysosomes for NF-κB signaling by either pseudotyping HIV with influenza hemagglutinin envelope or modification of CD4 mediated-intracellular trafficking. These data suggest that HIV envelope-CD4 receptor interactions drive pDC activation toward an immature IFN producing phenotype rather than differentiation into a mature dendritic cell phenotype. PMID:27082754

Modulation of the phenotype and function of Mycobacterium tuberculosis-stimulated dendritic cells by adrenal steroids.

PubMed

Angerami, Matias; Suarez, Guadalupe; Pascutti, Maria Fernanda; Salomon, Horacio; Bottasso, Oscar; Quiroga, Maria Florencia

2013-07-01

Cell-mediated immunity, cytokines induced during the specific immune response and T-cell populations are crucial factors for containing Mycobacterium tuberculosis infection. Recent reports suggest a cross-regulation between adrenal steroids (glucocorticoids and dehydroepiandrosterone, DHEA) and the function of antigen-presenting cells (APCs). Therefore, we investigated the role of adrenal hormones on the functional capacity of M. tuberculosis-induced dendritic cells (DCs). Cortisol significantly inhibited the functions of M. tuberculosis-induced DCs. Interestingly, the presence of DHEA enhanced the M. tuberculosis-induced expression of MHC I, MHC II and CD86 and also increased ERK1/2 phosphorylation. Moreover, DHEA improved the production of IL-12 in response to M. tuberculosis stimulation, diminished IL-10 secretion and could not modify TNF-α synthesis. Importantly, we observed that DHEA enhanced the antigen-specific T-cell proliferation and IFN-γ production induced by M. tuberculosis-stimulated DC. These data show for the first time the relevance of the adrenal axis (especially of DHEA) in the modulation of DC function in the context of tuberculosis, a disease where the induction of a Th1 environment by APCs is crucial for the development of an effective immune response to the mycobacteria.

Saccharomyces boulardii Inhibits EGF Receptor Signaling and Intestinal Tumor Growth in Apcmin Mice

PubMed Central

Chen, Xinhua; Fruehauf, Johannes; Goldsmith, Jeffrey D.; Xu, Hua; Katchar, Kianoosh K; Koon, Hon-Wai; Zhao, Dezheng; Kokkotou, Efi G.; Pothoulakis, Charalabos; Kelly, Ciarán P.

2009-01-01

Saccharomyces boulardii (Sb) is a probiotic yeast with anti-inflammatory and antimicrobial activities and has been used for decades in the prevention and treatment of a variety of human gastrointestinal disorders. We reported previously that Sb modulates host inflammatory responses through down regulation of Erk1/2 MAP kinase activities both in vitro and in vivo. The aim of this study was to identify upstream mediators responsible for Erk1/2 inactivation and to examine the effects of Sb on tumor development in ApcMin mice. We found that the EGF receptor was deactivated upon exposure to Sb leading to inactivation of both the EGFR-Erk and EGFR-Akt pathways. In human colonic cancer cells, Sb prevented EGF induced proliferation, reduced cell colony formation and promoted apoptosis. HER-2, HER-3 and IGF-1R were also found to be inactivated by Sb. Oral intake of Sb reduced intestinal tumor growth and dysplasia in C57BL/6J Min/+ (ApcMin) mice. Thus, in addition to its anti-inflammatory effects, S. boulardii inhibits EGFR and other receptor tyrosine kinase signaling and thereby may also serve a novel therapeutic or prophylactic role in intestinal neoplasia. PMID:19482027

Cot/Tpl2 regulates IL-23 p19 expression in LPS-stimulated macrophages through ERK activation.

PubMed

Kakimoto, K; Musikacharoen, T; Chiba, N; Bandow, K; Ohnishi, T; Matsuguchi, T

2010-03-01

We have previously reported that a serine/threonine protein kinase, Cot/Tpl2, is a negative regulator of Th1-type immunity through inhibiting IL-12 expression in antigen presenting cells (APCs) stimulated by Toll-like receptor (TLR) ligands. We here show that Cot/Tpl2(-/-) macrophages produce significantly less IL-23, an important regulator of Th17-type response, than the wild-type counterparts in response to lipopolysaccharide (LPS), which is a ligand for TLR4. The decreased IL-23 production in Cot/Tpl2(-/-) macrophages is, at least partly, regulated at the transcriptional level, as the LPS-mediated IL-23 p19 mRNA induction was significantly less in Cot/Tpl2(-/-) macrophages. Chemical inhibition of extracellular signal-regulated kinase (ERK) activity similarly inhibited IL-23 expression in LPS-stimulated wild-type macrophages. As Cot/Tpl2 is an essential upstream component of the ERK activation pathway of LPS, it is suggested that Cot/Tpl2 positively regulates IL-23 expression through ERK activation. These results indicate that Cot/Tpl2 may be involved in balancing Th1/Th17 differentiation by regulating the expression ratio of IL-12 and IL-23 in APCs.

V-set and Ig domain-containing 4 (VSIG4)-expressing hepatic F4/80+ cells regulate oral antigen-specific responses in mouse.

PubMed

Shin, Wonhwa; Jeon, Youkyoung; Choi, Inhak; Kim, Yeon-Jeong

2018-04-01

Oral tolerance can prevent unnecessary immune responses against dietary antigens. Members of the B7 protein family play critical roles in the positive and/or negative regulation of T cell responses to interactions between APCs and T cells. V-set and Ig domain-containing 4 (VSIG4), a B7-related co-signaling molecule, has been known to act as a co-inhibitory ligand and may be critical in establishing immune tolerance. Therefore, we investigated the regulation of VSIG4 signaling in a food allergy and experimental oral tolerance murine models. We analyzed the contributions of the two main sites involved in oral tolerance, the mesenteric lymph node (MLN) and the liver, in VSIG4-mediated oral tolerance induction. Through the comparative analysis of major APCs, dendritic cells (DCs) and macrophages, we found that Kupffer cells play a critical role in inducing regulatory T cells (Tregs) and establishing immune tolerance against oral antigens via VSIG4 signaling. Taken together, these results suggest the possibility of VSIG4 signaling-based regulation of orally administered antigens. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The World's Approach toward Publishing in Springer and Elsevier's APC-Funded Open Access Journals

ERIC Educational Resources Information Center

Sotudeh, Hajar; Ghasempour, Zahra

2018-01-01

Purpose: The present study explored tendencies of the world's countries--at individual and scientific development levels--toward publishing in APC-funded open access journals. Design/Methodology/Approach: Using a bibliometric method, it studied OA and NOA articles issued in Springer and Elsevier's APC journals? during 2007-2011. The data were…

Carbon and Mo transformations during the synthesis of mesoporous Mo2C/carbon catalysts by carbothermal hydrogen reduction

NASA Astrophysics Data System (ADS)

Wang, Haiyan; Liu, Shida; Liu, Bing; Montes, Vicente; Hill, Josephine M.; Smith, Kevin J.

2018-02-01

The synthesis of mesoporous Mo2C/carbon catalysts by carbothermal hydrogen reduction is reported. Petroleum coke (petcoke) was activated with KOH at 800 °C to obtain high surface area microporous activated petcoke (APC; 2000 m2/g). The APC was wet impregnated with ammonium heptamolybdate (AHM: 10 wt% Mo), dried and reduced in H2 at temperatures from 400 to 800 °C, to yield Mo2C/APC catalysts. Increased reduction temperature increased the Mo2C yield and the mesoporous volume of the Mo2C/APC. At a reduction temperature of 750 °C the mesopore volume of the catalyst doubled compared to the APC support and accounted for 37% of the total pore volume. Maintaining the final CHR temperature for 90 min further increased the Mo2C yield and mesoporosity of the catalyst. The role of Mo2C in the catalytic hydrogenation of the APC and mesopore generation is demonstrated. The activity of the Mo2C/carbon catalysts in the hydrodeoxygenation of 4-methyl phenol increased with increased CHR temperature and catalyst mesoporosity.

APC-PCI complex levels for screening of AAA in patients with peripheral atherosclerosis.

PubMed

Zarrouk, Moncef; Keshavarz, Kave; Lindblad, Bengt; Gottsäter, Anders

2013-11-01

To evaluate the use of activated protein C-protein C inhibitor (APC-PCI) complex levels for detection of abdominal aortic aneurysm (AAA) in patients with peripheral atherosclerotic disease (PAD). APC-PCI levels and aortic diameter evaluated in 511 PAD patients without previously known AAA followed-up concerning survival for 4.8(0.5) years. AAA was found in 13% of patients. Aortic diameter correlated (r = 0.138; p = 0.002) with APC-PCI levels which were higher (0.40[0.45] vs. 0.30[0.49] μg/l; p = 0.004) in patients with AAA. This difference persisted in multivariate analysis (p = 0.029). A threshold value of APC-PCI ≥0.15 μg/L showed a specificity of 11%, a sensitivity of 97% and a negative predictive value of 96% for an AAA diagnosis. APC-PCI levels were higher in patients with AAA, and showed high sensitivity but low specificity for the diagnosis and can therefore not be considered as a screening tool in PAD patients. An AAA prevalence of 13% in patients with PAD indicates a need for AAA screening within this population.

APC promoter 1B deletion in seven American families with familial adenomatous polyposis.

PubMed

Snow, A K; Tuohy, T M F; Sargent, N R; Smith, L J; Burt, R W; Neklason, D W

2015-10-01

Familial adenomatous polyposis (FAP) is a colorectal cancer predisposition syndrome caused by mutations in the adenomatous polyposis coli (APC) gene. Clinical genetic testing fails to identify disease causing mutations in up to 20% of clinically apparent FAP cases. Following the inclusion of multiplex ligation-dependent probe amplification (MLPA) probes specific for APC promoter 1B, seven probands were identified with a deletion of promoter 1B. Using haplotype analysis spanning the APC locus, the seven families appear to be identical by descent from a common founder. The clinical phenotype of 19 mutation carriers is classical FAP with colectomy at an average age of 24. The majority of cases had a large number of duodenal and gastric polyps. Measurements of allele-specific expression of APC mRNA using TaqMan assay confirmed that relative expression in the allele containing the promoter 1B deletion was reduced 42-98%, depending on tissue type. This study confirms the importance of APC promoter deletions as a cause of FAP and identifies a founder mutation in FAP patients from the United States. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Assessment of Microbiological Safety and Quality of Marinades Used To Treat Beef and That Were Collected over a 12-Month Period from Specialty Retailers Near Raleigh, North Carolina.

PubMed

Jung, Yangjin; Rupert, Christopher L; Chapman, Benjamin; Porto Fett, Anna C S; Luchansky, John B

2018-02-23

In total, 115 marinade samples (58 fresh marinades and 57 spent marinades) were collected over 12 months from specialty retailers (four individual stores) near Raleigh, NC. These marinades were screened for total mesophilic aerobic plate count (M-APC), total psychrotrophic aerobic plate count (P-APC), and Enterobacteriaceae. These marinades were also screened for the seven regulated serogroups of Shiga toxin-producing Escherichia coli. Stores A and B used immersion to marinade raw beef cuts, whereas stores C-1 and C-2 used vacuum tumbling. In general, marinade temperatures at the stores ranged from 1.8 to 6.6°C, and beef cuts were marinated from a few minutes to up to 3 days. Regardless of the process used to marinade meat, levels of M-APC and P-APC in fresh marinades ranged from 3.4 to 4.7 and 1.4 to 1.8 log CFU/mL, respectively, whereas Enterobacteriaceae were not detected in any fresh marinades, even after enrichment. However, levels of M-APC, P-APC, and Enterobacteriaceae in spent marinades collected from stores C-1 and C-2 (ca. 3.6 to 7.1 log CFU/mL) were significantly higher ( P < 0.05) compared with levels of these same types of bacteria enumerated from spent marinades collected at stores A and B (ca. ≤0.7 to 4.9 log CFU/mL). None of the 115 marinade samples tested positive for Shiga toxin-producing E. coli by using a BAX system real-time PCR assay. No significant ( P > 0.05) association was observed between microbial levels (i.e., M-APC, P-APC, and Enterobacteriaceae) and the temperature or duration of the marination process. Levels of M-APC, P-APC, and Enterobacteriaceae in spent marinades were significantly affected by the marination method ( P < 0.05), with levels, in general, being higher in marinades used for tumbling. Thus, retailers must continue to keep marinade solutions and meat at a safe temperature (i.e., ≤4°C) and to properly and frequently sanitize the equipment and environment in both the processing area and deli case.

Assessment of the Microbial Level for Livestock Products in Retail Meat Shops Implementing HACCP System

PubMed Central

Kim, Jung-hyun

2016-01-01

This study aimed to examine the microbial contamination levels in livestock products at retail stores. Beef, pork, and chicken samples from raw materials and final products were obtained between January and December 2015. All homogenized meat samples (25 g) were tested for the aerobic plate count (APC), coliform count (CC), and Escherichia coli count (E. coli). The highest APCs in meat samples, by month, at retail shops were obtained in September, followed by July, May, and October (p<0.001). However, APC was the highest in summer and the lowest in winter (p<0.001). Average APCs for beef, pork, and chicken samples were 2.90, 3.19, and 3.79 Log CFU/g, respectively (p<0.05). A comparison between different months revealed that, CC levels in meat samples ranged from 0 to 1.13 CFU/g, and the highest CC was obtained in August (p<0.001). By season, the highest CC was found in the summer, followed by autumn, and spring (p<0.001). All meat samples were negative for E. coli. The average log10APC and CC for all samples was 3.10 and 0.37 Log CFU/g, respectively. Furthermore, there was a direct correlation between the season and coliform presence (p<0.001). There was also a positive correlation between the APC and CC (r = 0.517, p<0.001). The microbiological APCs for livestock products were in most cases below 106 CFU/g. PMID:27857534

A novel approach to assess the spontaneous gastrointestinal bleeding risk of antithrombotic agents using Apc(min/+) mice.

PubMed

Wei, Huijun; Shang, Jin; Keohane, CarolAnn; Wang, Min; Li, Qiu; Ni, Weihua; O'Neill, Kim; Chintala, Madhu

2014-06-01

Assessment of the bleeding risk of antithrombotic agents is usually performed in healthy animals with some form of vascular injury to peripheral organs to induce bleeding. However, bleeding observed in patients with currently marketed antithrombotic drugs is typically spontaneous in nature such as intracranial haemorrhage (ICH) and gastrointestinal (GI) bleeding, which happens most frequently on top of preexisting pathologies such as GI ulcerations and polyps. Apc(min/+) mice are reported to develop multiple adenomas through the entire intestinal tract and display progressive anaemia.In this study, we evaluated the potential utility of Apc(min/+) mice as a model for assessing spontaneous GI bleeding with antithrombotic agents. Apc(min/+) mice exhibited progressive blood loss starting at the age of nine weeks. Despite the increase in bleeding, Apc(min/+) mice were in a hypercoagulable state and displayed an age-dependent increase in thrombin generation and circulating fibrinogen as well as a significant decrease in clotting times. We evaluated the effect of warfarin, dabigatran etexilate, apixaban and clopidogrel in this model by administering them in diet or in the drinking water to mice for 1-4 weeks. All of these marketed drugs significantly increased GI bleeding in Apc(min/+) mice, but not in wild-type mice. Although different exposure profiles of these antithrombotic agents make it challenging to compare the bleeding risk of compounds, our results indicate that the Apc(min/+) mouse may be a sensitive preclinical model for assessing the spontaneous GI bleeding risk of novel antithrombotic agents.

Preparation of activated petroleum coke for removal of naphthenic acids model compounds: Box-Behnken design optimization of KOH activation process.

PubMed

Niasar, Hojatallah Seyedy; Li, Hanning; Das, Sreejon; Kasanneni, Tirumala Venkateswara Rao; Ray, Madhumita B; Xu, Chunbao Charles

2018-04-01

This study employed Box-Behnken design and response surface methodology to optimize activation parameters for the production of activated petroleum coke (APC) adsorbent from petroleum coke (PC) to achieve highest adsorption capacity for three model naphthenic acids. Activated petroleum coke (APC) adsorbent with a BET surface area of 1726 m 2 /g and total pore volume of 0.85 cc/g was produced at the optimum activation conditions (KOH/coke mass ratio) of 3.0, activation temperature 790 °C, and activation time 3.47 h). Effects of the activation parameters on the adsorption pefromances (adsortion capaciy and kinetics) were investigated. With the APC obtained at the optimum activation condition, the maximum adsorption capacity of 451, 362, and 320 (mg/g) was achieved for 2-naphthoic acid, diphenylacetic acid and cyclohexanepentanoic acid (CP), respectively. Although, generally APC adsorbents with a higher specific surface area and pore volume provide better adsorption capacity, the textural properties (surface areas and pore volume) are not the only parameters determining the APC adsorbents' adsorption capacity. Other parameters such as surface functionalities play effective roles on the adsorption capacity of the produced APC adsorbents for NAs. The KOH activation process, in particular the acid washing step, distinctly reduced the sulfur and metals contents in the raw PC, decreasing the leaching potential of metals from APC adsorbents during adsorption. Copyright © 2018 Elsevier Ltd. All rights reserved.

Cellular context-dependent consequences of Apc mutations on gene regulation and cellular behavior.

PubMed

Hashimoto, Kyoichi; Yamada, Yosuke; Semi, Katsunori; Yagi, Masaki; Tanaka, Akito; Itakura, Fumiaki; Aoki, Hitomi; Kunisada, Takahiro; Woltjen, Knut; Haga, Hironori; Sakai, Yoshiharu; Yamamoto, Takuya; Yamada, Yasuhiro

2017-01-24

The spectrum of genetic mutations differs among cancers in different organs, implying a cellular context-dependent effect for genetic aberrations. However, the extent to which the cellular context affects the consequences of oncogenic mutations remains to be fully elucidated. We reprogrammed colon tumor cells in an Apc Min/+ (adenomatous polyposis coli) mouse model, in which the loss of the Apc gene plays a critical role in tumor development and subsequently, established reprogrammed tumor cells (RTCs) that exhibit pluripotent stem cell (PSC)-like signatures of gene expression. We show that the majority of the genes in RTCs that were affected by Apc mutations did not overlap with the genes affected in the intestine. RTCs lacked pluripotency but exhibited an increased expression of Cdx2 and a differentiation propensity that was biased toward the trophectoderm cell lineage. Genetic rescue of the mutated Apc allele conferred pluripotency on RTCs and enabled their differentiation into various cell types in vivo. The redisruption of Apc in RTC-derived differentiated cells resulted in neoplastic growth that was exclusive to the intestine, but the majority of the intestinal lesions remained as pretumoral microadenomas. These results highlight the significant influence of cellular context on gene regulation, cellular plasticity, and cellular behavior in response to the loss of the Apc function. Our results also imply that the transition from microadenomas to macroscopic tumors is reprogrammable, which underscores the importance of epigenetic regulation on tumor promotion.

Cellular context-dependent consequences of Apc mutations on gene regulation and cellular behavior

PubMed Central

Hashimoto, Kyoichi; Yamada, Yosuke; Semi, Katsunori; Yagi, Masaki; Tanaka, Akito; Itakura, Fumiaki; Aoki, Hitomi; Kunisada, Takahiro; Woltjen, Knut; Haga, Hironori; Sakai, Yoshiharu; Yamamoto, Takuya; Yamada, Yasuhiro

2017-01-01

The spectrum of genetic mutations differs among cancers in different organs, implying a cellular context-dependent effect for genetic aberrations. However, the extent to which the cellular context affects the consequences of oncogenic mutations remains to be fully elucidated. We reprogrammed colon tumor cells in an ApcMin/+ (adenomatous polyposis coli) mouse model, in which the loss of the Apc gene plays a critical role in tumor development and subsequently, established reprogrammed tumor cells (RTCs) that exhibit pluripotent stem cell (PSC)-like signatures of gene expression. We show that the majority of the genes in RTCs that were affected by Apc mutations did not overlap with the genes affected in the intestine. RTCs lacked pluripotency but exhibited an increased expression of Cdx2 and a differentiation propensity that was biased toward the trophectoderm cell lineage. Genetic rescue of the mutated Apc allele conferred pluripotency on RTCs and enabled their differentiation into various cell types in vivo. The redisruption of Apc in RTC-derived differentiated cells resulted in neoplastic growth that was exclusive to the intestine, but the majority of the intestinal lesions remained as pretumoral microadenomas. These results highlight the significant influence of cellular context on gene regulation, cellular plasticity, and cellular behavior in response to the loss of the Apc function. Our results also imply that the transition from microadenomas to macroscopic tumors is reprogrammable, which underscores the importance of epigenetic regulation on tumor promotion. PMID:28057861

Activated protein C cofactor function of protein S: a critical role for Asp95 in the EGF1-like domain

PubMed Central

Andersson, Helena M.; Arantes, Márcia J.; Crawley, James T. B.; Luken, Brenda M.; Tran, Sinh; Dahlbäck, Björn; Rezende, Suely M.

2010-01-01

Protein S has an established role in the protein C anticoagulant pathway, where it enhances the factor Va (FVa) and factor VIIIa (FVIIIa) inactivating property of activated protein C (APC). Despite its physiological role and clinical importance, the molecular basis of its action is not fully understood. To clarify the mechanism of the protein S interaction with APC, we have constructed and expressed a library of composite or point variants of human protein S, with residue substitutions introduced into the Gla, thrombin-sensitive region (TSR), epidermal growth factor 1 (EGF1), and EGF2 domains. Cofactor activity for APC was evaluated by calibrated automated thrombography (CAT) using protein S–deficient plasma. Of 27 variants tested initially, only one, protein S D95A (within the EGF1 domain), was largely devoid of functional APC cofactor activity. Protein S D95A was, however, γ-carboxylated and bound phospholipids with an apparent dissociation constant (Kdapp) similar to that of wild-type (WT) protein S. In a purified assay using FVa R506Q/R679Q, purified protein S D95A was shown to have greatly reduced ability to enhance APC-induced cleavage of FVa Arg306. It is concluded that residue Asp95 within EGF1 is critical for APC cofactor function of protein S and could define a principal functional interaction site for APC. PMID:20308596

The Governance of the National Assessment of Educational Progress: A Brief Review and Some Options. Report No. A-158-5.

ERIC Educational Resources Information Center

Boruch, Robert F.

This report concerns the governance of the structure of the National Assessment of Educational Progress (NAEP), especially the law and the role of the Assessment Policy Committee (APC). The major sources of evidence include interviews with APC members and National Institute of Education (NIE) staff, minutes of APC meetings and historical documents…

Head and neck squamous cell cancers in the United States are rare and the risk now is higher among white individuals compared with black individuals.

PubMed

Fakhry, Carole; Krapcho, Martin; Eisele, David W; D'Souza, Gypsyamber

2018-05-15

The increasing incidence of oropharyngeal squamous cell cancer (OPSCC) is well established. However, up-to-date incidence estimates and trends for head and neck squamous cell cancers (HNSCCs) overall, including major anatomic sites, and nonoropharyngeal (non-OP) HNSCCs by sex, race, and age in the United States are not well described. A retrospective analysis of incident HNSCCs during 1992 through 2014 using the Surveillance, Epidemiology, and End Results database was performed to evaluate the incidence of HNSCCs overall, OPSCC, and non-OP HNSCC (those of the larynx, oral cavity, hypopharynx, nasopharynx, and nasal cavity). Incidence rates were calculated overall and by subgroups of interest, and incidence rate ratios were used to compare rates between groups. The incidence rates presented were per 100,000 population and were age adjusted to the 2000 US standard population (19 age groups; Census P25-1130). The annual percent change (APC) was modeled with and without joinpoints. The incidence of HNSCC overall declined (average APC [aAPC], -0.8; P<.001) despite significant increases in the incidence of OPSCCs, most notably between 2000 and 2014 (APC, 2.1; P<.001). Significant declines in incidence were observed for all non-OP HNSCC sites for both women and men (P<.001 each). Among women, the risk of OPSCC also significantly decreased (aAPC, -0.8; P = .002), whereas the risk among men was stable during 1992 through 2001 (APC, 0.4; P = .42) and then significantly increased from 2001 to 2014 (APC, 2.7; P<.001). Decreases in the risk of non-OP HNSCC were especially large for black women (aAPC, -2.6; P<.001) and men (aAPC, -3.0; P<.001). Although the incidence of HNSCC previously was highest among black individuals, since 2009 its incidence has been higher among white compared with black individuals. The incidence of HNSCC is declining, especially for non-OP HNSCC and among black individuals. Cancer 2018;124:2125-33. © 2018 American Cancer Society. © 2018 American Cancer Society.

Termination of T cell priming relies on a phase of unresponsiveness promoting disengagement from APCs and T cell division.

PubMed

Bohineust, Armelle; Garcia, Zacarias; Beuneu, Hélène; Lemaître, Fabrice; Bousso, Philippe

2018-05-07

T cells are primed in secondary lymphoid organs by establishing stable interactions with antigen-presenting cells (APCs). However, the cellular mechanisms underlying the termination of T cell priming and the initiation of clonal expansion remain largely unknown. Using intravital imaging, we observed that T cells typically divide without being associated to APCs. Supporting these findings, we demonstrate that recently activated T cells have an intrinsic defect in establishing stable contacts with APCs, a feature that was reflected by a blunted capacity to stop upon T cell receptor (TCR) engagement. T cell unresponsiveness was caused, in part, by a general block in extracellular calcium entry. Forcing TCR signals in activated T cells antagonized cell division, suggesting that T cell hyporesponsiveness acts as a safeguard mechanism against signals detrimental to mitosis. We propose that transient unresponsiveness represents an essential phase of T cell priming that promotes T cell disengagement from APCs and favors effective clonal expansion. © 2018 Bohineust et al.

Submucosal injection of normal saline may prevent tissue damage from argon plasma coagulation: an experimental study using resected porcine esophagus, stomach, and colon.

PubMed

Fujishiro, Mitsuhiro; Yahagi, Naohisa; Nakamura, Masanori; Kakushima, Naomi; Kodashima, Shinya; Ono, Satoshi; Kobayashi, Katsuya; Hashimoto, Takuhei; Yamamichi, Nobutake; Tateishi, Ayako; Shimizu, Yasuhito; Oka, Masashi; Ichinose, Masao; Omata, Masao

2006-10-01

Argon plasma coagulation (APC) is considered to be a safe thermocoagulation technique, but some reports show perforation and deformity during and after APC. In this study, we investigated the usefulness of prior submucosal injection for APC. APC over the mucosa was performed on fresh resected porcine esophagus, stomach, and colon with prior submucosal injection of normal saline (injection group) and without it (control group). The depth of tissue damage increased linearly with pulse duration up to the shallower submucosal layer in both groups. After that, tissue damage in the injection group remained confined to the shallower submucosal layer under any condition, whereas that in the control group continued to extend. The tissue damages of the injection groups were significantly (P<0.05) shallower than those of the control groups that reached the deeper submucosal layer in all the organs. Submucosal injection of normal saline before the application of APC may limit tissue damage and prevent perforation and deformity.

Air pollution control residues from waste incineration: current UK situation and assessment of alternative technologies.

PubMed

Rani, D Amutha; Boccaccini, A R; Deegan, D; Cheeseman, C R

2008-11-01

Current disposal options for APC residues in the UK and alternative treatment technologies developed world-wide have been reviewed. APC residues are currently landfilled in the UK where they undergo in situ solidification, although the future acceptability of this option is uncertain because the EU waste acceptance criteria (WAC) introduce strict limits on leaching that are difficult to achieve. Other APC residue treatment processes have been developed which are reported to reduce leaching to below relevant regulatory limits. The Ferrox process, the VKI process, the WES-PHix process, stabilisation/solidification using cementitious binders and a range of thermal treatment processes are reviewed. Thermal treatment technologies convert APC residues combined with other wastes into inert glass or glass-ceramics that encapsulate heavy metals. The waste management industry will inevitably use the cheapest available option for treating APC residues and strict interpretation and enforcement of waste legislation is required if new, potentially more sustainable technologies are to become commercially viable.

Resource Recovery Technology Application Document.

DTIC Science & Technology

1982-06-01

B-6 Electrostatic Precipitator (APC-C) ......................B-1O Venturi Scrubber (APC D) B-15 C Combustion Equipment (CE) C-1 Modular... Scrubber APC-D P. 1 of 4 CONTROLIII COMPONENT DESCRIPTION Types Available - Competing Components Type a. Venturi e. Moving bed Venturi b. Flooded disc f...Clean Gas to Demister (Used Separate Liquid from Gas Stream) / F C Scrubber Wall Liquid Inlet D Scrubber Liquid at Venturi Throat Inlet B E Venturi

Occupational Structures and Profiles in Italy in the Field of Environmental Protection in the Public Service Sector with Reference to Air Pollution Control. CEDEFOP Panorama. National Report.

ERIC Educational Resources Information Center

Mannocci, Virgilio; And Others

A study examined the knowledge and job skills required of persons employed in air pollution control (APC)-related occupations in Italy's public service sector. First, Italian legislation on APC and the functions/powers of Italy's public agencies responsible for APC were reviewed. The organization/operation of the public structures involved in…

Successful marriage: American Panel Corporation and LG Philips LCD custom-designed avionic, shipboard, and rugged ground vehicle display modules from a consumer-oriented fabrication facility

NASA Astrophysics Data System (ADS)

Dunn, William; Garrett, Kimberly S.

2001-09-01

American panel corporation (APC) believes the use of custom designed (instead of ruggedized commercial) AMLCD cells is the only way to meet the specific environmental and performance requirements of the military/commercial avionic, shipboard and rugged ground vehicle markets. The APC/LG.Philips LCD (LG) custom approach mitigates risk to the end-user in many ways. As a part of the APC/LG long- term agreement LG has committed to provide module level equivalent (form, fit and function equivalent) panels for a period of ten years. No other commercial glass manufacturer has provided such an agreement. With the use of LG's commercial production manufacturing capabilities, APC/LG can provide the opportunity to procure a lifetime buy for any program with delivery of the entire lot within six months of order placement. This ensures that the entire production program will receive identical glass for every unit. The APC/LG relationship works where others have failed due to the number of years spent cultivating the mutual trust and respect necessary for establishing such a partnership, LG's interest in capturing the market share of this niche application, and the magnitude of the initial up-front investment by APC in engineering, tooling, facilities, production equipment, and LCD cell inventory.

Mycobacterium tuberculosis manipulates pulmonary APCs subverting early immune responses.

PubMed

Garcia-Romo, Gina S; Pedroza-Gonzalez, Alexander; Lambrecht, Bart N; Aguilar-Leon, Diana; Estrada-Garcia, Iris; Hernandez-Pando, Rogelio; Flores-Romo, Leopoldo

2013-03-01

Alveolar macrophages (AM) and dendritic cells (DCs) are the main antigen presenting cells (APCs) in the respiratory tract. Whereas macrophages have been extensively studied in tuberculosis, in situ interactions of DC with Mycobacterium tuberculosis (Mtb) are poorly explored. We aimed to characterize lung APCs during pulmonary tuberculosis in Balb/C mice infected with Mtb H37Rv. Mtb-infection via the airways induced a delayed and continuous accumulation of DCs and AM in the lungs. While lung DCs increased after day 3 post-infection, macrophages increased after 2-3 weeks. Although both populations accumulated in lungs during the infection, DCs decreased in the late stages. Infection induced differential expression of co-stimulatory molecules in these lung APCs, decreasing to basal levels in both APCs in the late stages. A remarkable segregation was found regarding bacillary burden. Many macrophages contained numerous bacilli, but DC contained scarce mycobacteria or none. Mtb-infection also induced delayed accumulation of DC in draining lymph nodes. This delayed recruitment was not associated with a lack of IL-12p40, which was detected from day 3 post-infection. Although AM and lung DCs behave differently during pulmonary tuberculosis, Mtb apparently manipulates both lung APCs subverting early protective responses resulting in disease progression. Copyright © 2012 Elsevier GmbH. All rights reserved.

Different modes of APC/C activation control growth and neuron-glia interaction in the developing Drosophila eye.

PubMed

Neuert, Helen; Yuva-Aydemir, Yeliz; Silies, Marion; Klämbt, Christian

2017-12-15

The development of the nervous system requires tight control of cell division, fate specification and migration. The anaphase-promoting complex/cyclosome (APC/C) is an E3 ubiquitin ligase that affects different steps of cell cycle progression, as well as having postmitotic functions in nervous system development. It can therefore link different developmental stages in one tissue. The two adaptor proteins, Fizzy/Cdc20 and Fizzy-related/Cdh1, confer APC/C substrate specificity. Here, we show that two distinct modes of APC/C function act during Drosophila eye development. Fizzy/Cdc20 controls the early growth of the eye disc anlage and the concomitant entry of glial cells onto the disc. In contrast, fzr/cdh1 acts during neuronal patterning and photoreceptor axon growth, and subsequently affects neuron-glia interaction. To further address the postmitotic role of Fzr/Cdh1 in controlling neuron-glia interaction, we identified a series of novel APC/C candidate substrates. Four of our candidate genes are required for fzr/cdh1 -dependent neuron-glia interaction, including the dynein light chain Dlc90F Taken together, our data show how different modes of APC/C activation can couple early growth and neuron-glia interaction during eye disc development. © 2017. Published by The Company of Biologists Ltd.

Naringin, a natural dietary compound, prevents intestinal tumorigenesis in Apc (Min/+) mouse model.

PubMed

Zhang, Yu-Sheng; Li, Ye; Wang, Yan; Sun, Shi-Yue; Jiang, Tao; Li, Cong; Cui, Shu-Xiang; Qu, Xian-Jun

2016-05-01

Naringin is a natural dietary flavonoid compound. We aimed to evaluate the effects of naringin on intestinal tumorigenesis in the adenomatous polyposis coli multiple intestinal neoplasia (Apc (Min/+)) mouse model. Apc (Min/+) mice were given either naringin (150 mg/kg) or vehicle by p.o. gavage daily for 12 consecutive weeks. Mice were killed with ether, and blood samples were collected to assess the concentrations of IL-6 and PGE2. Total intestines were removed, and the number of polyps was examined. Tissue samples of intestinal polyps were subjected to the assays of histopathology, immunohistochemical analysis and Western blotting analysis. Apc (Min/+) mice fed with naringin developed less and smaller polyps in total intestines. Naringin prevented intestinal tumorigenesis without adverse effects. Histopathologic analysis revealed the reduction of dysplastic cells and dysplasia in the adenomatous polyps. The treatments' effects might arise from its anti-proliferation, induction of apoptosis and modulation of GSK-3β and APC/β-catenin signaling pathways. Naringin also exerted its effects on tumorigenesis through anti-chronic inflammation. Naringin prevented intestinal tumorigenesis likely through a collection of activities including anti-proliferation, induction of apoptosis, modulation of GSK-3β and APC/β-catenin pathways and anti-inflammation. Naringin is a potential chemopreventive agent for reducing the risk of colonic cancers.

APC-PC Combined Scheme in Gilbert Two State Model: Proposal and Study

NASA Astrophysics Data System (ADS)

Bulo, Yaka; Saring, Yang; Bhunia, Chandan Tilak

2017-04-01

In an automatic repeat request (ARQ) scheme, a packet is retransmitted if it gets corrupted due to transmission errors caused by the channel. However, an erroneous packet may contain both erroneous bits and correct bits and hence it may still contain useful information. The receiver may be able to combine this information from multiple erroneous copies to recover the correct packet. Packet combining (PC) is a simple and elegant scheme of error correction in transmitted packet, in which two received copies are XORed to obtain the bit location of erroneous bits. Thereafter, the packet is corrected by bit inversion of bit located as erroneous. Aggressive packet combining (APC) is a logic extension of PC primarily designed for wireless communication with objective of correcting error with low latency. PC offers higher throughput than APC, but PC does not correct double bit errors if occur in same bit location of erroneous copies of the packet. A hybrid technique is proposed to utilize the advantages of both APC and PC while attempting to remove the limitation of both. In the proposed technique, applications of APC-PC on Gilbert two state model has been studied. The simulation results show that the proposed technique offers better throughput than the conventional APC and lesser packet error rate than PC scheme.

Purification and in vitro antioxidant activities of tellurium-containing phycobiliproteins from tellurium-enriched Spirulina platensis.

PubMed

Yang, Fang; Wong, Ka-Hing; Yang, Yufeng; Li, Xiaoling; Jiang, Jie; Zheng, Wenjie; Wu, Hualian; Chen, Tianfeng

2014-01-01

Tellurium-containing phycocyanin (Te-PC) and allophycocyanin (Te-APC), two organic tellurium (Te) species, were purified from tellurium-enriched Spirulina platensis by a fast protein liquid chromatographic method. It was found that the incorporation of Te into the peptides enhanced the antioxidant activities of both phycobiliproteins. With fractionation by ammonium sulfate precipitation and hydroxylapatite chromatography, Te-PC and Te-APC could be effectively separated with high purity, and Te concentrations were 611.1 and 625.3 μg g(-1) protein in Te-PC and Te-APC, respectively. The subunits in the proteins were identified by using MALDI-TOF-TOF mass spectrometry. Te incorporation enhanced the antioxidant activities of both phycobiliproteins, as examined by 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid assay. Moreover, Te-PC and Te-APC showed dose-dependent protection on erythrocytes against the water-soluble free radical initiator 2,2'-azo(2-asmidinopropane)dihydrochloride-induced hemolysis. In the hepatoprotective model, apoptotic cell death and nuclear condensation induced by tert-butyl hydroperoxide in HepG2 cells was significantly attenuated by Te-PC and Te-APC. Taken together, these results suggest that Te-PC and Te-APC are promising Te-containing proteins with application potential for treatment of diseases related to oxidative stress.

Purification and in vitro antioxidant activities of tellurium-containing phycobiliproteins from tellurium-enriched Spirulina platensis

PubMed Central

Yang, Fang; Wong, Ka-Hing; Yang, Yufeng; Li, Xiaoling; Jiang, Jie; Zheng, Wenjie; Wu, Hualian; Chen, Tianfeng

2014-01-01

Tellurium-containing phycocyanin (Te-PC) and allophycocyanin (Te-APC), two organic tellurium (Te) species, were purified from tellurium-enriched Spirulina platensis by a fast protein liquid chromatographic method. It was found that the incorporation of Te into the peptides enhanced the antioxidant activities of both phycobiliproteins. With fractionation by ammonium sulfate precipitation and hydroxylapatite chromatography, Te-PC and Te-APC could be effectively separated with high purity, and Te concentrations were 611.1 and 625.3 μg g−1 protein in Te-PC and Te-APC, respectively. The subunits in the proteins were identified by using MALDI-TOF-TOF mass spectrometry. Te incorporation enhanced the antioxidant activities of both phycobiliproteins, as examined by 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid assay. Moreover, Te-PC and Te-APC showed dose-dependent protection on erythrocytes against the water-soluble free radical initiator 2,2′-azo(2-asmidinopropane)dihydrochloride-induced hemolysis. In the hepatoprotective model, apoptotic cell death and nuclear condensation induced by tert-butyl hydroperoxide in HepG2 cells was significantly attenuated by Te-PC and Te-APC. Taken together, these results suggest that Te-PC and Te-APC are promising Te-containing proteins with application potential for treatment of diseases related to oxidative stress. PMID:25336922

Ikaros-Notch axis in host hematopoietic cells regulates experimental graft-versus-host disease

PubMed Central

Toubai, Tomomi; Sun, Yaping; Tawara, Isao; Friedman, Ann; Liu, Chen; Evers, Rebecca; Nieves, Evelyn; Malter, Chelsea; Chockley, Peter; Maillard, Ivan; Winandy, Susan

2011-01-01

Host hematopoietically derived APCs play a vital role in the initiation of GVH responses. However, the APC autonomous molecular mechanisms that are critical for the induction of GVHD are not known. We report here that the Ikaros-Notch axis in host hematopoietically derived APCs regulates the severity of acute GVHD across multiple clinically relevant murine models of experimental bone marrow transplantation. In the present study, Ikaros deficiency (Ik−/−) limited to host hematopoietically derived APCs enhanced donor T-cell expansion and intensified acute GVHD, as determined by survival and other GVHD-specific parameters. The Ik−/− conventional CD8+ and CD8−CD11c+ dendritic cells (DCs), the most potent APCs, showed no increase in the expression of activation markers or in response to TLR stimulation compared with wild-type controls. However, Ik−/− DCs demonstrated an enhanced stimulation of allogeneic T cells. Deficiency of Ikaros in the conventional CD8+ and CD8−CD11c+ DCs was associated with an increase in Notch signaling, the blockade of which mitigated the enhanced in vitro and in vivo allostimulatory capacity. Therefore, the Ikaros-Notch axis is a novel pathway that modulates DC biology in general, and targeting this pathway in host hematopoietically derived APCs may reduce GVHD. PMID:21471527

Engineered artificial antigen presenting cells facilitate direct and efficient expansion of tumor infiltrating lymphocytes

PubMed Central

2011-01-01

Background Development of a standardized platform for the rapid expansion of tumor-infiltrating lymphocytes (TILs) with anti-tumor function from patients with limited TIL numbers or tumor tissues challenges their clinical application. Methods To facilitate adoptive immunotherapy, we applied genetically-engineered K562 cell-based artificial antigen presenting cells (aAPCs) for the direct and rapid expansion of TILs isolated from primary cancer specimens. Results TILs outgrown in IL-2 undergo rapid, CD28-independent expansion in response to aAPC stimulation that requires provision of exogenous IL-2 cytokine support. aAPCs induce numerical expansion of TILs that is statistically similar to an established rapid expansion method at a 100-fold lower feeder cell to TIL ratio, and greater than those achievable using anti-CD3/CD28 activation beads or extended IL-2 culture. aAPC-expanded TILs undergo numerical expansion of tumor antigen-specific cells, remain amenable to secondary aAPC-based expansion, and have low CD4/CD8 ratios and FOXP3+ CD4+ cell frequencies. TILs can also be expanded directly from fresh enzyme-digested tumor specimens when pulsed with aAPCs. These "young" TILs are tumor-reactive, positively skewed in CD8+ lymphocyte composition, CD28 and CD27 expression, and contain fewer FOXP3+ T cells compared to parallel IL-2 cultures. Conclusion Genetically-enhanced aAPCs represent a standardized, "off-the-shelf" platform for the direct ex vivo expansion of TILs of suitable number, phenotype and function for use in adoptive immunotherapy. PMID:21827675

Newly synthesized curcumin analog has improved potential to prevent colorectal carcinogenesis in vivo.

PubMed

Shibata, Hiroyuki; Yamakoshi, Hiroyuki; Sato, Atsuko; Ohori, Hisatsugu; Kakudo, Yuichi; Kudo, Chieko; Takahashi, Yayoi; Watanabe, Mika; Takano, Hiroshi; Ishioka, Chikashi; Noda, Tetsuo; Iwabuchi, Yoshiharu

2009-05-01

Curcumin (diferuloylmethane) has chemopreventive and chemotherapeutic potentials against various types of cancers. We have developed a series of curcumin analogs to improve its low bioavailability by enhancing its potentials. The newly synthesized analog GO-Y030 [(1E, 4E)-1,5-bis-(3,5(-bismethoxymethoxyphenyl) penta-1,4-dien-3-one] showed a 30-fold greater growth suppression in vitro via similar molecular mechanisms to curcumin. The availability of this analog was examined by using a mouse model harboring the germ-line mutation of Apc, Apc(580D/+), in vivo. Apc(580D/+) mice had a very limited survival time with an intestinal obstruction due to polyposis. The average tumor number in mice fed GO-Y030 was reduced to 61.2% of those that were fed the basal diet (P < 0.05). Compared with Apc(580D/+) mice fed the basal diet (median survival time = 166.5 days), a significantly prolonged lifespan (213 days) was observed in Apc(580D/+) mice fed GO-Y030. The chemopreventive effect with GO-Y030 was improved, compared with curcumin (191 days). The survival benefit corresponded to the diminished intestinal tumor incidence in Apc(580D/+) mice fed GO-Y030. No adverse reactions were observed, judging from body weight or biochemical data concerning liver and renal damage. Degradation of accumulated beta-catenin with curcumin is one of the major mechanisms of chemoprevention in colorectal carcinogenesis. It was demonstrated that the number of beta-catenin-positive adenoma cells in Apc(580D/+) mice fed GO-Y030 was reduced.

Cellular Pathway(S) of Antigen Processing and Presentation in Fish APC: Endosomal Involvement and Cell-Free Antigen Presentation

PubMed Central

Vallejo, Abbe N.; Miller, Norman W.; Harvey, Nancy E.; Cuchens, Marvin A.; Warr, Gregory W.

1992-01-01

Studies were conducted to address further the role(s) of antigen processing and presentation in the induction of immune responses in a phylogenetically lower vertebrate, specifically a teleost, the channel catfish. In particular, studies were aimed at determining the subcellular compartments involved in antigen degradation by channel catfish antigen-presenting cells (APC) as well as ascertaining the reexpression of immunogenic peptides on the surfaces of APC. The results showed that exogenous protein antigens were actively endocytosed by APC as detected by flow cytometry. Use of radiolabeled antigen and subcellular fractionation protocols also showed that antigen localized in endosomes/lysosomes. Furthermore, there was an apparent redistribution of antigen between these organelles and the plasma membrane during the course of antigen pulsing. Functional assays for the induction of in vitro antigen-specific proliferation of immune catfish peripheral blood leukocytes (PBL) showed that membrane preparations from antigen-pulsed autologous APC were highly stimulatory. The magnitude of responses elicited with such membrane preparations was very similar to that of PBL cultures stimulated with native antigen-pulsed and fixed intact APC or prefixed intact APC incubated with a peptide fragment of the nominal antigen. Current data further corroborate our previous findings that steps akin to antigen processing and presentation are clearly important in the induction of immune responses in lower vertebrates like fish, in a manner similar to that seen in mammalian systems. Consequently, it would appear that many immune functions among the diverse taxa of vertebrates are remarkably conserved. PMID:1343103

Phenotypic and Functional Properties of Human Steady State CD14+ and CD1a+ Antigen Presenting Cells and Epidermal Langerhans Cells.

PubMed

Fehres, Cynthia M; Bruijns, Sven C M; Sotthewes, Brigit N; Kalay, Hakan; Schaffer, Lana; Head, Steven R; de Gruijl, Tanja D; Garcia-Vallejo, Juan J; van Kooyk, Yvette

2015-01-01

Cutaneous antigen presenting cells (APCs) are critical for the induction and regulation of skin immune responses. The human skin contains phenotypically and functionally distinct APCs subsets that are present at two separated locations. While CD1ahigh LCs form a dense network in the epidermis, the CD14+ and CD1a+ APCs reside in the dermal compartment. A better understanding of the biology of human skin APC subsets is necessary for the improvement of vaccine strategies that use the skin as administration route. In particular, progress in the characterization of uptake and activatory receptors will certainly improve APC-targeting strategies in vaccination. Here we performed a detailed analysis of the expression and function of glycan-binding and pattern-recognition receptors in skin APC subsets. The results demonstrate that under steady state conditions human CD1a+ dermal dendritic cells (DCs) were phenotypically most mature as measured by the expression of CD83 and CD86, whereas the CD14+ cells showed a higher expression of the CLRs DC-SIGN, mannose receptor and DCIR and had potent antigen uptake capacity. Furthermore, steady state LCs showed superior antigen cross-presentation as compared to the dermal APC subsets. Our results also demonstrate that the TLR3 ligand polyribosinic-polyribocytidylic acid (pI:C) was the most potent stimulator of cytokine production by both LCs and dDCs. These studies warrant further exploration of human CD1a+ dDCs and LCs as target cells for cancer vaccination to induce anti-tumor immune responses.

Defining the rectal dose constraint for permanent radioactive seed implantation of the prostate.

PubMed

Albert, Michele; Song, Jun S; Schultz, Delray; Cormack, Robert A; Tempany, Clare M; Haker, Steve; Devlin, Phillip M; Beard, Clair; Hurwitz, Mark D; Suh, Wonsuk W; Jolesz, Ferenc; D'Amico, Anthony V

2008-01-01

This study was performed to define the rectal dose constraint that would predict late rectal bleeding requiring argon plasma coagulation (APC) following prostate brachy mono-therapy. Between February 1999 and April 2002, 91 patients with low risk prostate cancer underwent permanent I(125) radioactive seed implantation without the use of supplemental external beam radiation or androgen suppression therapy. Patients received both CT and MRI scans 6 weeks postimplant for evaluation of dosimetry. The CT and MRI scans were fused. Rectal volumes were contoured on the T2 weighted MR images. For those patients requiring APC, the date on which a patient reported rectal bleeding was recorded. A Cox regression analysis was performed to assess whether there was a significant association between the rectal volume (continuous) exceeding 100 Gy time rectal bleeding. Comparisons of estimates of rectal bleeding requiring APC were made using a 2-sided log rank test. There was a significant association (hazard ratio = 5.6 [95% confidence interval: 1.3, 23.8]; P = 0.002) between the rectal volume exceeding 100 Gy and rectal bleeding requiring APC. After a median follow-up of 4.25 (1-6) years, no patient with less than a median value of 8 cc of rectum exceeding 100 Gy required APC, whereas 20% (P = 0.004) were estimated to require APC within 3 years following treatment. Keeping the rectal volume receiving more than 100 Gy below 8 cc will minimize the risk of rectal bleeding requiring APC following I(125) permanent prostate brachy mono-therapy.

A blinded randomized controlled trial evaluating the usefulness of a novel diet (aminoprotect care) in dogs with spontaneous food allergy.

PubMed

Olivry, Thierry; Kurata, Keigo; Paps, Judy S; Masuda, Kenichi

2007-10-01

Aminoprotect Care (APC) is a novel diet composed of aminoacids, potato proteins and corn starch. The objectives of this study were to determine whether Maltese-Beagle atopic (MBA) dogs hypersensitive to corn exhibited clinical signs and changes in immunological markers after being fed APC. The study was designed as a blinded randomized controlled crossover experiment. Ten MBA dogs with signs of allergy within five days of ingesting corn were selected. Dogs were randomized to be fed either their maintenance diet with corn or APC for five days. After a washout of two weeks, diets were switched. Before and daily during each intervention, skin lesions were graded by an investigator while pruritus was assessed by another. Before and at the end of each intervention, the percentage of circulating CD4+CCR4+, corn-activated CD4+ T-lymphocytes and serum corn-specific IgE levels were measured and ratios of post:pre values calculated. During this trial, pruritus and skin lesions increased significantly in MBA dogs when ingesting corn while no such increase occurred when fed APC. Total, median and maximal pruritus values were significantly higher in MBA dogs ingesting corn compared to APC. There were no significant differences between interventions in the immunological parameters assessed. In summary, even though APC contains corn starch to which corn-sensitive MBA dogs often react, the ingestion of APC did not lead to significant increases in skin lesions or pruritus. Aminoprotect Care might prove valuable for management of food allergies. These experimental observations must be validated in large field studies.

Dispensing error rate after implementation of an automated pharmacy carousel system.

PubMed

Oswald, Scott; Caldwell, Richard

2007-07-01

A study was conducted to determine filling and dispensing error rates before and after the implementation of an automated pharmacy carousel system (APCS). The study was conducted in a 613-bed acute and tertiary care university hospital. Before the implementation of the APCS, filling and dispensing rates were recorded during October through November 2004 and January 2005. Postimplementation data were collected during May through June 2006. Errors were recorded in three areas of pharmacy operations: first-dose or missing medication fill, automated dispensing cabinet fill, and interdepartmental request fill. A filling error was defined as an error caught by a pharmacist during the verification step. A dispensing error was defined as an error caught by a pharmacist observer after verification by the pharmacist. Before implementation of the APCS, 422 first-dose or missing medication orders were observed between October 2004 and January 2005. Independent data collected in December 2005, approximately six weeks after the introduction of the APCS, found that filling and error rates had increased. The filling rate for automated dispensing cabinets was associated with the largest decrease in errors. Filling and dispensing error rates had decreased by December 2005. In terms of interdepartmental request fill, no dispensing errors were noted in 123 clinic orders dispensed before the implementation of the APCS. One dispensing error out of 85 clinic orders was identified after implementation of the APCS. The implementation of an APCS at a university hospital decreased medication filling errors related to automated cabinets only and did not affect other filling and dispensing errors.

Activated protein C resistance in patients following venous thromboembolism receiving rivaroxaban versus vitamin K antagonists: assessment using Russell viper venom time-based assay.

PubMed

Goralczyk, Tadeusz; Wojtowicz, Katarzyna B; Undas, Anetta

2017-06-01

: Activated protein C resistance (APC-R) is assessed as part of thrombophilia screening, preferably in patients not taking oral anticoagulants. Rivaroxaban is known to alter some APC-R assays. To our knowledge, there have been no reports on the effect of rivaroxaban on the Russell viper venom time (RVVT)-based APC-R assay in real-life patients. In 168 consecutive outpatients suspected of having venous thromboembolism because of thrombophilia, APC-R was determined using the RVVT-based ProC Ac R assay (Siemens, Marburg, Germany). Patients receiving rivaroxaban or vitamin K antagonists were eligible. We measured rivaroxaban concentrations using the anti-Xa Biophen DiXal assay (Hyphen Biomed, Neuville-Sur-Oise, France) and factor V Leiden using the real-time PCR. APC-R was detected in 23 (28%) patients on rivaroxaban (n = 81) administrated 2-48 h since the blood draw, 15 (28%) patients on vitamin K antagonists (n = 54), and in four (12%) patients off anticoagulation (n = 33). Compared with nonanticoagulated patients, APC-R ratios were similar in patients on rivaroxaban, without any correlation with rivaroxaban concentrations (from 0 to 303 μg/l). None of the patients on rivaroxaban were found to have false-negative or false-positive APC-R ratios. Rivaroxaban concentrations up to 300 μg/l do not affect results of the ProC Ac R RVVT-based assay, which could be recommended in patients referred to a clinic for thrombophilia screening in whom the time since the last dose of rivaroxaban is uncertain.

Sex Differences in the Relationship of IL-6 Signaling to Cancer Cachexia Progression

PubMed Central

Hetzler, Kimbell L.; Hardee, Justin P.; Puppa, Melissa J.; Narsale, Aditi A.; Sato, Shuichi; Davis, J. Mark; Carson, James A.

2015-01-01

A devastating aspect of cancer cachexia is severe loss of muscle and fat mass. Though cachexia occurs in both sexes, it is not well-defined in the female. The Apc Min/+ mouse is genetically predisposed to develop intestinal tumors; circulating IL-6 is a critical regulator of cancer cachexia in the male Apc Min/+ mouse. The purpose of this study was to examine the relationship between IL-6 signaling and cachexia progression in the female Apc Min/+ mouse. Male and female Apc Min/+ mice were examined during the initiation and progression of cachexia. Another group of females had IL-6 overexpressed between 12-14 weeks or 15-18 weeks of age to determine whether IL-6 could induce cachexia. Cachectic female Apc Min/+ mice lost body weight, muscle mass, and fat mass; increased muscle IL-6 mRNA expression was associated with these changes, but circulating IL-6 levels were not. Circulating IL-6 levels did not correlate with downstream signaling in muscle in the female. Muscle IL-6r mRNA expression and SOCS3 mRNA expression as well as muscle IL-6r protein and STAT3 phosphorylation increased with severe cachexia in both sexes. Muscle SOCS3 protein increased in cachectic females but decreased in cachectic males. IL-6 overexpression did not affect cachexia progression in female Apc Min/+ mice. Our results indicate that female Apc Min/+ mice undergo cachexia progression that is at least initially IL-6-independent. Future studies in the female will need to determine mechanisms underlying regulation of IL-6 response and cachexia induction. PMID:25555992

Advanced Practice Clinician Training for Neurology.

PubMed

Ermak, David M; Cox, Lori; Ahmed, Aiesha

2017-04-26

The specialty of Neurology is faced with a fundamental problem of economics: supply and demand. The projected increase in provider supply is unlikely to keep up with projected increases in patient-care demand. Many large academic centers have used residents to meet this patient-care demand. However, the conflict between education of residents and patient-care needs has created a hindrance to both of those missions. Many specialties have been using advanced practice clinicians (APCs) to help address the need for patient care. In the setting of a residency program, this availability of APCs can help to alleviate patient-care demands for the resident and allow for better allocated educational time. Neurology has not historically been a popular choice for APCs and a standardized educational curriculum for a Neurology APC has not been established. The authors share an example curriculum recently implemented for training new inpatient Neurology APCs. This curriculum includes a 12-week program complete with rotations through various subspecialties and proposes fundamental lecture topics for use in education. The authors share their expectations for clinical duties that evolve over the course of the 12-week program in conjunction with expectations for increasing clinical knowledge as well as efficiency in system utilization. The addition of APCs to support a busy inpatient Neurology practice has obvious beneficial implications but the integration and education of this new staff must be structured and well-designed to support the confidence of the APC in both their knowledge and their role as an indispensable member of the care team.

Umbilical cord blood regulatory T-cell expansion and functional effects of tumor necrosis factor receptor family members OX40 and 4-1BB expressed on artificial antigen-presenting cells

PubMed Central

Harker-Murray, Paul; Porter, Stephen B.; Merkel, Sarah C.; Londer, Aryel; Taylor, Dawn K.; Bina, Megan; Panoskaltsis-Mortari, Angela; Rubinstein, Pablo; Van Rooijen, Nico; Golovina, Tatiana N.; Suhoski, Megan M.; Miller, Jeffrey S.; Wagner, John E.; June, Carl H.; Riley, James L.

2008-01-01

Previously, we showed that human umbilical cord blood (UCB) regulatory T cells (Tregs) could be expanded approximately 100-fold using anti-CD3/28 monoclonal antibody (mAb)–coated beads to provide T-cell receptor and costimulatory signals. Because Treg numbers from a single UCB unit are limited, we explored the use of cell-based artificial antigen-presenting cells (aAPCs) preloaded with anti-CD3/28 mAbs to achieve higher levels of Treg expansion. Compared with beads, aAPCs had similar expansion properties while significantly increasing transforming growth factor β (TGF-β) secretion and the potency of Treg suppressor function. aAPCs modified to coexpress OX40L or 4-1BBL expanded UCB Tregs to a significantly greater extent than bead- or nonmodified aAPC cultures, reaching mean expansion levels exceeding 1250-fold. Despite the high expansion and in contrast to studies using other Treg sources, neither OX40 nor 4-1BB signaling of UCB Tregs reduced in vitro suppression. UCB Tregs expanded with 4-1BBL expressing aAPCs had decreased levels of proapoptotic bim. UCB Tregs expanded with nonmodified or modified aAPCs versus beads resulted in higher survival associated with increased Treg persistence in a xeno-geneic graft-versus-host disease lethality model. These data offer a novel approach for UCB Treg expansion using aAPCs, including those coexpressing OX40L or 4-1BBL. PMID:18645038

Commentary: open access, open business, closed fairness!

PubMed

Moustafa, Khaled

2015-01-01

A strong trend to move from print to online publication is largely perceived in scientific and nonscientific fields. A growing number of publishers increasingly opt for online publication as an option or a compulsory alternative. From readers' perspective, this is a highly appreciated facility, but from the author's, things are different mainly because of excessive article processing charges (APC) that make the open access system sometimes as a hindrance for many authors but a lucrative enterprise for many shareholders, enticing the most traditional and conservative publishers.

Impact of Hormone-Associated Resistance to Activated Protein C on the Thrombotic Potential of Oral Contraceptives: A Prospective Observational Study

PubMed Central

Müller, Jens; Sukhitashvili, Shorena; Welz, Julia; Kuhn, Walther C.; Oldenburg, Johannes; Rudlowski, Christian; Pötzsch, Bernd

2014-01-01

Introduction The increased thrombotic risk of oral contraceptives (OC) has been attributed to various alterations of the hemostatic system, including acquired resistance to activated protein C (APC). To evaluate to what extent OC-associated APC resistance induces a prothrombotic state we monitored plasma levels of thrombin and molecular markers specific for thrombin formation in women starting OC use. Elevated plasma levels of thrombin have been reported to characterize situations of high thrombotic risk such as trauma-induced hypercoagulability, but have not yet been studied during OC use. Patients and Methods Blood samples were collected prospectively from healthy women (n = 21) before and during three menstruation cycles after start of OC. APC resistance was evaluated using a thrombin generation-based assay. Plasma levels of thrombin and APC were directly measured using highly sensitive oligonucleotide-based enzyme capture assay (OECA) technology. Thrombin generation markers and other hemostasis parameters were measured additionally. Results All women developed APC resistance as indicated by an increased APC sensitivity ratio compared with baseline after start of OC (p = 0.0003). Simultaneously, plasma levels of thrombin, prothrombin fragment 1+2, and of thrombin-antithrombin complexes did not change, ruling out increased thrombin formation. APC plasma levels were also not influenced by OC use, giving further evidence that increased thrombin formation did not occur. Conclusions In the majority of OC users no enhanced thrombin formation occurs despite the development of APC resistance. It cannot be ruled out, however, that thrombin formation might occur to a greater extent in the presence of additional risk factors. If this were the case, endogenous thrombin levels might be a potential biomarker candidate to identify women at high thrombotic risk during OC treatment. Large-scale studies are required to assess the value of plasma levels of thrombin as predictors of OC-associated thrombotic risk. PMID:25121606

APC Yin-Yang haplotype associated with colorectal cancer risk

PubMed Central

GARRE, P.; DE LA HOYA, M.; INIESTA, P.; ROMERA, A.; LLOVET, P.; GONZALEZ, S.; PEREZ-SEGURA, P.; CAPELLA, G.; DIAZ-RUBIO, E.; CALDES, T.

2010-01-01

The Yin-Yang haplotype is defined as two mismatched haplotypes (Yin and Yang) representing the majority of the existing haplotypes in a particular genomic region. The human adenomatous polyposis coli (APC) gene shows a Yin-Yang haplotype pattern accounting for 84% of all of the haplotypes existing in the Spanish population. Several association studies have been published regarding APC gene variants (SNPs and haplotypes) and colorectal cancer (CRC) risk. However, no studies concerning diplotype structure and CRC risk have been conducted. The aim of the present study was to investigate whether the APC Yin-Yang homozygote diplotype is over-represented in patients with sporadic CRC when compared to its distribution in controls, and its association with CRC risk. TaqMan® assays were used to genotype three tagSNPs selected across the APC Yin-Yang region. Frequencies of the APC Yin-Yang tagSNP alleles, haplotype and diplotype of 378 CRC cases and 642 controls were compared. Two Spanish CRC group samples were included [Hospital Clínico San Carlos in Madrid (HCSC) and Instituto Catalán de Oncología in Barcelona (ICO)]. Analysis of 157 consecutive CRC patients and 405 control subjects from HCSC showed a significative effect for the risk of CRC (OR=1.93; 95% CI 1.32–2.81; P=0.001). However, this effect was not confirmed in 221 CRC patients and 237 control subjects from ICO (OR=0.89; 95% CI 0.61–1.28; P=0.521). We found a significant association between the APC homozygote Yin-Yang diplotype and the risk of colorectal cancer in the HCSC samples. However, we did not observe this association in the ICO samples. These observations suggest that a study with a larger Spanish cohort is necessary to confirm the effects of the APC Yin-Yang diplotype on the risk of CRC. PMID:22993613

APC Yin-Yang haplotype associated with colorectal cancer risk.

PubMed

Garre, P; DE LA Hoya, M; Iniesta, P; Romera, A; Llovet, P; Gonzalez, S; Perez-Segura, P; Capella, G; Diaz-Rubio, E; Caldes, T

2010-09-01

The Yin-Yang haplotype is defined as two mismatched haplotypes (Yin and Yang) representing the majority of the existing haplotypes in a particular genomic region. The human adenomatous polyposis coli (APC) gene shows a Yin-Yang haplotype pattern accounting for 84% of all of the haplotypes existing in the Spanish population. Several association studies have been published regarding APC gene variants (SNPs and haplotypes) and colorectal cancer (CRC) risk. However, no studies concerning diplotype structure and CRC risk have been conducted. The aim of the present study was to investigate whether the APC Yin-Yang homozygote diplotype is over-represented in patients with sporadic CRC when compared to its distribution in controls, and its association with CRC risk. TaqMan(®) assays were used to genotype three tagSNPs selected across the APC Yin-Yang region. Frequencies of the APC Yin-Yang tagSNP alleles, haplotype and diplotype of 378 CRC cases and 642 controls were compared. Two Spanish CRC group samples were included [Hospital Clínico San Carlos in Madrid (HCSC) and Instituto Catalán de Oncología in Barcelona (ICO)]. Analysis of 157 consecutive CRC patients and 405 control subjects from HCSC showed a significative effect for the risk of CRC (OR=1.93; 95% CI 1.32-2.81; P=0.001). However, this effect was not confirmed in 221 CRC patients and 237 control subjects from ICO (OR=0.89; 95% CI 0.61-1.28; P=0.521). We found a significant association between the APC homozygote Yin-Yang diplotype and the risk of colorectal cancer in the HCSC samples. However, we did not observe this association in the ICO samples. These observations suggest that a study with a larger Spanish cohort is necessary to confirm the effects of the APC Yin-Yang diplotype on the risk of CRC.

Potential of polarization lidar to provide profiles of CCN- and INP-relevant aerosol parameters

NASA Astrophysics Data System (ADS)

Mamouri, R. E.; Ansmann, A.

2015-12-01

We investigate the potential of polarization lidar to provide vertical profiles of aerosol parameters from which cloud condensation nucleus (CCN) and ice nucleating particle (INP) number concentrations can be estimated. We show that height profiles of number concentrations of aerosol particles with radius > 50 nm (APC50, reservoir of favorable CCN) and with radius > 250 nm (APC250, reservoir of favorable INP), as well as profiles of the aerosol particle surface area concentration (ASC, used in INP parameterization) can be retrieved from lidar-derived aerosol extinction coefficients (AEC) with relative uncertainties of a factor of around 2 (APC50), and of about 25-50 % (APC250, ASC). Of key importance is the potential of polarization lidar to identify mineral dust particles and to distinguish and separate the aerosol properties of basic aerosol types such as mineral dust and continental pollution (haze, smoke). We investigate the relationship between AEC and APC50, APC250, and ASC for the main lidar wavelengths of 355, 532 and 1064 nm and main aerosol types (dust, pollution, marine). Our study is based on multiyear Aerosol Robotic Network (AERONET) photometer observations of aerosol optical thickness and column-integrated particle size distribution at Leipzig, Germany, and Limassol, Cyprus, which cover all realistic aerosol mixtures of continental pollution, mineral dust, and marine aerosol. We further include AERONET data from field campaigns in Morocco, Cabo Verde, and Barbados, which provide pure dust and pure marine aerosol scenarios. By means of a simple relationship between APC50 and the CCN-reservoir particles (APCCCN) and published INP parameterization schemes (with APC250 and ASC as input) we finally compute APCCCN and INP concentration profiles. We apply the full methodology to a lidar observation of a heavy dust outbreak crossing Cyprus with dust up to 8 km height and to a case during which anthropogenic pollution dominated.

Effects of supplemental calcium and vitamin D on the APC/β-catenin pathway in the normal colorectal mucosa of colorectal adenoma patients.

PubMed

Liu, Siyu; Barry, Elizabeth L; Baron, John A; Rutherford, Robin E; Seabrook, March E; Bostick, Roberd M

2017-02-01

APC/β-catenin pathway malfunction is a common and early event in colorectal carcinogenesis. To assess calcium and vitamin D effects on the APC/β-catenin pathway in the normal-appearing colorectal mucosa of sporadic colorectal adenoma patients, nested within a larger randomized, double-blind, placebo-controlled, partial 2 × 2 factorial chemoprevention clinical trial of supplemental calcium (1200 mg daily) and vitamin D (1000 IU daily), alone and in combination versus placebo, we assessed APC, β-catenin, and E-cadherin expression in colon crypts in normal-appearing rectal mucosa biopsies from 104 participants at baseline and 1-yr follow up using standardized, automated immunohistochemistry and quantitative image analysis. For vitamin D versus no vitamin D, the ratio of APC expression to β-catenin expression in the upper 40% (differentiation zone) of crypts (APC/β-catenin score) increased by 28% (P = 0.02), for calcium versus no calcium it increased by 1% (P = 0.88), and for vitamin D + calcium versus calcium by 35% (P = 0.01). Total E-cadherin expression increased by 7% (P = 0.35) for vitamin D versus no vitamin D, 8% (P = 0.31) for calcium versus no calcium, and 12% (P = 0.21) for vitamin D + calcium versus calcium. These results support (i) that vitamin D, alone or in combination with calcium, may modify APC, β-catenin, and E-cadherin expression in humans in directions hypothesized to reduce risk for colorectal neoplasms; (ii) vitamin D as a potential chemopreventive agent against colorectal neoplasms; and (iii) the potential of APC, β-catenin, and E-cadherin expression as treatable, pre-neoplastic risk biomarkers for colorectal neoplasms. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Mutation analysis of the p53, APC, and p16 genes in the Barrett's oesophagus, dysplasia, and adenocarcinoma.

PubMed Central

González, M V; Artímez, M L; Rodrigo, L; López-Larrea, C; Menéndez, M J; Alvarez, V; Pérez, R; Fresno, M F; Pérez, M J; Sampedro, A; Coto, E

1997-01-01

AIMS: To study the loss of heterozygosity and the presence of mutations at the p53, p16/CDKN2, and APC genes in Barrett's oesophagus, low grade dysplastic oesophageal epithelium, and adenocarcinoma of the oesophagus; to relate the presence of alterations at these genes with the progression from Barrett's oesophagus to adenocarcinoma. METHODS: DNA was extracted from paraffin blocks containing tissue from Barrett's oesophagus (12 samples), low grade dysplasia (15 cases), and adenocarcinoma (14 cases). Loss of heterozygosity (LOH) at the p53, p16, and APC genes was determined by comparing the autoradiographic patterns of several microsatellite markers between the normal tissue and the malignant tissue counterpart. SSCP was used to determine the presence of mutations at p53 (exons 5 to 8), p16 (exon 2), and APC. Homozygous deletion of the p16 gene was defined through polymerase chain reaction followed by Southern blot. RESULTS: LOH at the p53, p16, and APC genes was not observed in Barrett's oesophagus without dysplasia, and increased to 90% (p53), 89% (p16), and 60% (APC) in the adenocarcinomas. The p53 gene was mutated in only two adenocarcinomas (codons 175 and 245). In one case a mutation at the APC gene (codon 1297) was found. No patient had mutation at the second exon of p16. However, this gene was homozygously deleted in three of the 12 adenocarcinomas. CONCLUSIONS: The tumour suppressor genes p53, p16, and APC are often deleted in adenocarcinomas derived from Barrett's oesophagus. Mutations at these genes are also found in the adenocarcinomas, including the homozygous deletion of the p16 gene. However, the absence of genetic alterations in the Barrett's oesophagus and the low grade dysplastic epithelia suggest that mutations at these genes develop later in the progression from Barrett's oesophagus to adenocarcinoma. Images PMID:9155671

Paracrine release of IL-2 and anti-CTLA-4 enhances the ability of artificial polymer antigen-presenting cells to expand antigen-specific T cells and inhibit tumor growth in a mouse model.

PubMed

Zhang, Lei; Wang, Limin; Shahzad, Khawar Ali; Xu, Tao; Wan, Xin; Pei, Weiya; Shen, Chuanlai

2017-09-01

Accumulating evidence indicates that bead-based artificial antigen-presenting cells (aAPCs) are a powerful tool to induce antigen-specific T cell responses in vitro and in vivo. To date, most conventional aAPCs have been generated by coupling an antigen signal (signal 1) and one or two costimulatory signals, such as anti-CD28 with anti-LFA1 or anti-4-1BB (signal 2), onto the surfaces of cell-sized or nanoscale magnetic beads or polyester latex beads. The development of a biodegradable scaffold and the combined use of multiple costimulatory signals as well as third signals for putative clinical applications is the next step in the development of this technology. Here, a novel biodegradable aAPC platform for active immunotherapy was developed by co-encapsulating IL-2 and anti-CTLA-4 inside cell-sized polylactic-co-glycolic acid microparticles (PLGA-MPs) while co-coupling an H-2K b /TRP2-Ig dimer and anti-CD28 onto the surface. Cytokines (activating signal) and antibodies (anti-inhibition signal) were efficiently co-encapsulated in PLGA-MP-based aAPCs and co-released without interfering with each other. The targeted, sustained co-release of IL-2 and anti-CTLA-4 achieved markedly enhanced, synergistic effects in activating and expanding tumor antigen-specific T cells both in vitro and in vivo, as well as in inhibiting tumor growth in a mouse melanoma model, as compared with conventional two-signal aAPCs and IL-2 or anti-CTLA-4 single-released aAPCs. These data revealed the feasibility and importance of the paracrine release of multiple costimulatory molecules and cytokines from biodegradable aAPCs and thus provide a proof of principle for the future use of polymeric aAPCs for active immunotherapy of tumors and infectious diseases.

Aspirin augments the expression of Adenomatous Polyposis Coli protein by suppression of IKKβ

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

Ashida, Noboru, E-mail: nashida@kuhp.kyoto-u.ac.jp; Kishihata, Masako; Tien, Dat Nguyen

Highlights: • Clinical studies revealed aspirin inhibits cancer, but the mechanism is not known. • Adenomatous Polyposis Coli (APC) is a well-known tumor-suppressing gene. • We found aspirin up-regulates the protein of APC. • Aspirin suppressed the expression of IKKβ, an essential kinase in NFκB activation. • The deletion of IKKβ significantly increases the expression of APC protein. - Abstract: Aspirin has been widely used as analgesic, antipyretic and anti-inflammatory medicine for long. In addition to these traditional effects, clinical studies suggest that aspirin can protect against cancer, but its mechanism has not been explored. To unveil it, we identifiedmore » the proteins up- or down-regulated after incubation with aspirin by using proteomics analysis with Nano-flow LC/MALDI-TOF system. Interestingly, the analysis identified the protein of Adenomatous Polyposis Coli (APC) as one of the most up-regulated protein. APC regulates cell proliferation or angiogenesis, and is widely known as a tumor-suppressing gene which can cause colorectal cancer when it is mutated. Western blots confirmed this result, and real-time PCR indicated it is transcriptionally regulated. We further tried to elucidate the molecular mechanism with focusing on IKKβ. IKKβ is the essential kinase in activation of nuclear factor-kappa B (NF-κB), major transcriptional factors that regulate genes responsible for inflammation or immune response. Previous reports indicated that aspirin specifically inhibits IKKβ activity, and constitutively active form of IKKβ accelerates APC loss. We found that aspirin suppressed the expression of IKKβ, and the deletion of IKKβ by siRNA increases the expression of APC in HEK294 cells. Finally, we observed similar effects of aspirin in human umbilical vein endothelial cells. Taken together, these results reveal that aspirin up-regulates the expression of APC via the suppression of IKKβ. This can be a mechanism how aspirin prevents cancer at least in part, and a novel link between inflammatory NF-κB signaling and cancer.« less

Trends in the Incidence of In Situ and Invasive Cervical Cancer by Age Group and Histological Type in Korea from 1993 to 2009

PubMed Central

Oh, Chang-Mo; Jung, Kyu-Won; Won, Young-Joo; Shin, Aesun; Kong, Hyun-Joo; Jun, Jae Kwan; Park, Sang-yoon

2013-01-01

Objective Our study aims to describe changes in carcinoma in situ (CIS) and invasive cervical carcinoma (ICC) in Korean women diagnosed between 1993 and 2009. Methods All cases of CIS and invasive cervical carcinoma diagnosed from 1993 to 2009 in the Korean National Cancer Incidence database were analyzed. Age-standardized rates (ASRs) and annual percent changes (APCs) in incidence rates were compared according to age and histological type. Additionally, we used Korea National Health and Nutrition Examination Survey (KNHANES) to know the association between screening rate for cervical cancer and incidence rate of cervical cancer. Results Between 1993 and 2009, 72,240 cases of ICC were reported in Korea. Total incidence rate of ICC was 14.7 per 100,000 females. ASRs of ICC declined 3.8% per year, from 19.3 per 100,000 in 1993 to 10.5 per 100,000 in 2009. Although the overall incidence rate of adenocarcinoma remained stable, invasive squamous cell carcinoma showed a decreasing trend (APC −4.2%). For women aged 60–79 years, ASRs for squamous cell carcinoma increased from 1993 to 2001, and decreased from 2001 to 2009 (APC: −4.6%). Total 62,300 cases of CIS were diagnosed from 1993 to 2009. Total incidence rate of CIS was 12.2 per 100,000 females. ASRs of CIS increased 5.7% per year, from 7.5 per 100,000 in 1993 to 19.0 per 100,000 in 2009. Adenocarcinoma in situ increased 13.2% per year. There was a strong positive correlation between screening rate for cervical cancer and incidence rate for CIS (p-value = 0.03) whereas screening rate showed a strong negative correlation with incidence rate for squamous ICC (p-value = 0.04). Conclusions The increasing trend in CIS, coupled with a decreasing trend in ICC, suggests the important role of cervix cancer screening. The incidence of adenocarcinoma showed a plateau, but the incidence of adenocarcinoma in situ showed an increasing trend. PMID:23977194

Rapid detection of translation-terminating mutations at the adenomatous polyposis coli (APC) gene by direct protein truncation test

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

Van Der Luut, R.; Khan, P.M.; Van Leeuwen, C.

Familial adenomatous polyposis (FAP) is usually associated with protein truncating mutations in the adenomatous polyposis coli (APC) gene. The APC mutations are known to play a major role in colorectal carcinogensis. For the identification of protein truncating mutations of the APC gene, the authors developed a rapid, sensitive, and direct screening procedure. The technique is based on the in vitro transcription and translation of the genomic PCR products and is called the protein truncation test. Samples of DNA from individual FAP patients, members of a FAP family, colorectal tumors, and colorectal tumor-derived cell lines were used to show the effectivenessmore » of this method. 9 refs., 2 figs.« less

B cells are critical to T-cell-mediated antitumor immunity induced by a combined immune-stimulatory/conditionally cytotoxic therapy for glioblastoma.

PubMed

Candolfi, Marianela; Curtin, James F; Yagiz, Kader; Assi, Hikmat; Wibowo, Mia K; Alzadeh, Gabrielle E; Foulad, David; Muhammad, A K M G; Salehi, Sofia; Keech, Naomi; Puntel, Mariana; Liu, Chunyan; Sanderson, Nicholas R; Kroeger, Kurt M; Dunn, Robert; Martins, Gislaine; Lowenstein, Pedro R; Castro, Maria G

2011-10-01

We have demonstrated that modifying the tumor microenvironment through intratumoral administration of adenoviral vectors (Ad) encoding the conditional cytotoxic molecule, i.e., HSV1-TK and the immune-stimulatory cytokine, i.e., fms-like tyrosine kinase 3 ligand (Flt3L) leads to T-cell-dependent tumor regression in rodent models of glioblastoma. We investigated the role of B cells during immune-mediated glioblastoma multiforme regression. Although treatment with Ad-TK+Ad-Flt3L induced tumor regression in 60% of wild-type (WT) mice, it completely failed in B-cell-deficient Igh6(-/-) mice. Tumor-specific T-cell precursors were detected in Ad-TK+Ad-Flt3L-treated WT mice but not in Igh6(-/-) mice. The treatment also failed in WT mice depleted of total B cells or marginal zone B cells. Because we could not detect circulating antibodies against tumor cells and the treatment was equally efficient in WT mice and in mice with B-cell-specific deletion of Prdm 1 (encoding Blimp-1), in which B cells are present but unable to fully differentiate into antibody-secreting plasma cells, tumor regression in this model is not dependent on B cells' production of tumor antigen-specific immunoglobulins. Instead, B cells seem to play a role as antigen-presenting cells (APCs). Treatment with Ad-TK+Ad-Flt3L led to an increase in the number of B cells in the cervical lymph nodes, which stimulated the proliferation of syngeneic T cells and induced clonal expansion of antitumor T cells. Our data show that B cells act as APCs, playing a critical role in clonal expansion of tumor antigen-specific T cells and brain tumor regression.

Lipopolysaccharide-Induced Acute Kidney Injury Is Dependent on an IL-18 Receptor Signaling Pathway

PubMed Central

Nozaki, Yuji; Hino, Shoichi; Ri, Jinhai; Sakai, Kenji; Nagare, Yasuaki; Kawanishi, Mai; Niki, Kaoru; Funauchi, Masanori; Matsumura, Itaru

2017-01-01

The proinflammatory cytokine interleukin (IL)-18 is an important mediator of the organ failure induced by endotoxemia. IL-18 (known as an interferon-gamma (IFN-γ) inducing factor), and other inflammatory cytokines have important roles in lipopolysaccharide (LPS)-induced acute kidney injury (AKI). We investigated the effect of inflammatory cytokines and Toll-like receptor 4 (TLR4) expression, an event that is accompanied by an influx of monocytes, including CD4+ T cells and antigen-presenting cells (APCs) in IL-18Rα knockout (KO) mice and wild-type (WT) mice after LPS injection. In the acute advanced phase, the IL-18Rα KO mice showed a higher survival rate and a suppressed increase of blood urea nitrogen, increased levels of proinflammatory cytokines such as IFN-γ and IL-18, the infiltration of CD4+ T cells and the expression of kidney injury molecule-1 as an AKI marker. In that phase, the renal mRNA expression of the M1 macrophage phenotype and C-C chemokine receptor type 7 as the maturation marker of dendritic cells (DCs) was also significantly decreased in the IL-18Rα KO mice, although there were small numbers of F4/80+ cells and DCs in the kidney. Conversely, there were no significant differences in the expressions of mRNA and protein TLR4 after LPS injection between the WT and IL-18Rα KO groups. Our results demonstrated that the IL-18Rα-mediated signaling pathway plays critical roles in CD4+ T cells and APCs and responded more quickly to IFN-γ and IL-18 than TLR4 stimulation in the pathogenesis of LPS-induced AKI. PMID:29261164

IL-10 down-regulates T cell activation by antigen-presenting liver sinusoidal endothelial cells through decreased antigen uptake via the mannose receptor and lowered surface expression of accessory molecules.

PubMed

Knolle, P A; Uhrig, A; Hegenbarth, S; Löser, E; Schmitt, E; Gerken, G; Lohse, A W

1998-12-01

Our study demonstrates that antigen-presenting liver sinusoidal endothelial cells (LSEC) induce production of interferon-gamma (IFN-gamma) from cloned Th1 CD4+ T cells. We show that LSEC used the mannose receptor for antigen uptake, which further strengthened the role of LSEC as antigen-presenting cell (APC) population in the liver. The ability of LSEC to activate cloned CD4+ T cells antigen-specifically was down-regulated by exogenous prostaglandin E2 (PGE2) and by IL-10. We identify two separate mechanisms by which IL-10 down-regulated T cell activation through LSEC. IL-10 decreased the constitutive surface expression of MHC class II as well as of the accessory molecules CD80 and CD86 on LSEC. Furthermore, IL-10 diminished mannose receptor activity in LSEC. Decreased antigen uptake via the mannose receptor and decreased expression of accessory molecules may explain the down-regulation of T cell activation through IL-10. Importantly, the expression of low numbers of antigen on MHC II in the absence of accessory signals on LSEC may lead to induction of anergy in T cells. Because PGE2 and IL-10 are released from LSEC or Kupffer cells (KC) in response to those concentrations of endotoxin found physiologically in portal venous blood, it is possible that the continuous presence of these mediators and their negative effect on the local APC may explain the inability of the liver to induce T cell activation and to clear chronic infections. Our results support the notion that antigen presentation by LSEC in the hepatic microenvironment contributes to the observed inability to mount an effective cell-mediated immune response in the liver.

Strengthening of antitumor immune memory and prevention of thymic atrophy mediated by adenovirus expressing IL-12 and GM-CSF.

PubMed

Choi, K-J; Zhang, S-N; Choi, I-K; Kim, J-S; Yun, C-O

2012-07-01

Interleukin (IL)-12 and granulocyte-monocyte colony-stimulating factor (GM-CSF) have recently been used as immunotherapeutic agents in cancer gene therapy. IL-12 and GM-CSF have differential roles in the antitumor immune response, as IL-12 targets T, NK and natural killer T (NKT) cells and GM-CSF principally targets antigen-presenting cells (APCs). To strengthen the therapeutic efficacy of these two cytokines, we generated an oncolytic adenovirus (Ad), Ad-ΔB7/IL12/GMCSF, coexpressing IL-12 and GM-CSF. Using a murine B16-F10 syngeneic tumor model, we show that Ad-ΔB7/IL12/GMCSF promoted antitumor responses and increased survival compared with an oncolytic Ad expressing IL-12 or GM-CSF alone (Ad-ΔB7/IL12 or Ad-ΔB7/GMCSF, respectively). By measuring cytotoxic T lymphocyte activity and interferon-γ production, we show that the enhanced therapeutic effect was mediated by the induction of immune cell cytotoxicity. In situ delivery of Ad-ΔB7/IL12/GMCSF resulted in massive infiltration of CD4(+) T cells, CD8(+) T cells, NK cells and CD86(+) APCs into the tissue surrounding the necrotic area of the tumor. Moreover, GM-CSF effectively promoted antitumor immune memory, which was significantly augmented by IL-12. Lastly, IL12-expressing oncolytic Ads prevented tumor-induced thymic atrophy and was associated with reduced apoptosis and increased proliferation in the thymus. Taken together, these data demonstrate that an oncolytic Ad coexpressing IL-12 and GM-CSF is a potential therapeutic tool for the treatment of cancer.

Silencing or inhibition of endoplasmic reticulum aminopeptidase 1 (ERAP1) suppresses free heavy chain expression and Th17 responses in ankylosing spondylitis

PubMed Central

Chen, Liye; Ridley, Anna; Hammitzsch, Ariane; Al-Mossawi, Mohammad Hussein; Bunting, Helen; Georgiadis, Dimitris; Chan, Antoni; Kollnberger, Simon; Bowness, Paul

2016-01-01

Objective Human leucocyte antigen (HLA)-B27 and endoplasmic reticulum aminopeptidase 1 (ERAP1) are strongly associated with ankylosing spondylitis (AS). ERAP1 is a key aminopeptidase in HLA class I presentation and can potentially alter surface expression of HLA-B27 free heavy chains (FHCs). We studied the effects of ERAP1 silencing/inhibition/variations on HLA-B27 FHC expression and Th17 responses in AS. Methods Flow cytometry was used to measure surface expression of HLA class I in peripheral blood mononuclear cells (PBMCs) from patients with AS carrying different ERAP1 genotypes (rs2287987, rs30187 and rs27044) and in ERAP1-silenced/inhibited/mutated HLA-B27-expressing antigen presenting cells (APCs). ERAP1-silenced/inhibited APCs were cocultured with KIR3DL2CD3ε-reporter cells or AS CD4+ T cells. Th17 responses of AS CD4+ T cells were measured by interleukin (IL)-17A ELISA and Th17 intracellular cytokine staining. FHC cell surface expression and Th17 responses were also measured in AS PBMCs following ERAP1 inhibition. Results The AS-protective ERAP1 variants, K528R and Q730E, were associated with reduced surface FHC expression by monocytes from patients with AS and HLA-B27-expressing APCs. ERAP1 silencing or inhibition in APCs downregulated HLA-B27 FHC surface expression, reduced IL-2 production by KIR3DL2CD3ε-reporter cells and suppressed the Th17 expansion and IL-17A secretion by AS CD4+ T cells. ERAP1 inhibition of AS PBMCs reduced HLA class I FHC surface expression by monocytes and B cells, and suppressed Th17 expansion. Conclusions ERAP1 activity determines surface expression of HLA-B27 FHCs and potentially promotes Th17 responses in AS through binding of HLA-B27 FHCs to KIR3DL2. Our data suggest that ERAP1 inhibition has potential for AS treatment. PMID:26130142

Chromogranin A as a useful neuroendocrine marker in patients with autoimmune Addison's disease.

PubMed

El Ali, Z; Fichna, M; Piniewska, J; Kosowicz, J; Grzymisławski, M

2010-03-01

Antiparietal cells antibodies (APC-Ab) are commonly found in patients with autoimmune Addison's disease (AAD), usually pointing to autoimmune atrophic gastritis and pernicious anemia. The autoaggression to the gastric proton pumpmay result in a long-term hypergastrinemia, which predisposes to enterochromaffin-like cell hyper/dysplasia and gastric carcinoids. We evaluated the clinical utility of assessing serum chromogranin A levels in patients with AAD. Serum chromogranin A, gastrin, and gastric APC-Ab levels were determined in 40 patients with AAD using commercially available kits. Serum chromogranin A and gastrin levels were found to be elevated in 27.5 and 22.5% of patients with AAD, respectively. The Addison's patients with elevated APC-Ab had significantly higher chromogranin A and gastrin levels, as compared to individuals with normal APC-Ab (chromogranin A: 128.00+/-123.08 vs 57.68+/-36.50 ng/ml, p=0.0036; gastrin: 141.38+/-191.43 vs 49.50+/-75.36 muU/ml, p=0.003). Additionally, the patients with AAD and coexisting elevated serum APC-Ab, contrary to those with normal levels, showed a significant correlation between the chromogranin A and gastrin concentrations (r=0.52, p=0.0092 vs r=0.211, p=0.43). Serum chromogranin A appeared also significantly correlated with APC-Ab levels (r=0.431, p=0.005). In patients with autoimmune Addison's disease hyperchromograninemia and hypergastrinemia occur with a prevalence of 27.5 and 22.5%, respectively. Addison's patients with coexisting elevated gastric APC-Ab, particularly with elevated gastrin levels, are at risk of enterochromaffin-like cells hyper/dysplasia. Serum chromogranin A assessment may complement histology for the early diagnosis of gastric carcinoid in these patients.

Incidence, Trends and Ethnic Differences of Oropharyngeal, Anal and Cervical Cancers: Singapore, 1968-2012

PubMed Central

Lam, Jennifer O.; Lim, Wei-Yen; Chow, Khuan-Yew; D’Souza, Gypsyamber

2015-01-01

In recent decades, several Western countries have reported an increase in oropharyngeal and anal cancers caused by human papillomavirus (HPV). Trends in HPV-associated cancers in Asia have not been as well described. We describe the epidemiology of potentially HPV-related cancers reported to the Singapore Cancer Registry from 1968–2012. Analysis included 998 oropharyngeal squamous cell carcinoma (OPSCC), 183 anal squamous cell carcinoma (ASCC) and 8,019 invasive cervical cancer (ICC) cases. Additionally, 368 anal non-squamous cell carcinoma (ANSCC) and 2,018 non-oropharyngeal head and neck carcinoma (non-OP HNC) cases were included as comparators. Age-standardized incidence rates (ASR) were determined by gender and ethnicity (Chinese, Malay and Indian). Joinpoint regression was used to evaluate annual percentage change (APC) in incidence. OPSCC incidence increased in both genders (men 1993–2012, APC = 1.9%, p<0.001; women 1968–2012, APC = 2.0%, p = 0.01) and was 5 times higher in men than women. In contrast, non-OP HNC incidence declined between 1968–2012 among men (APC = -1.6%, p<0.001) and women (APC = -0.4%, p = 0.06). ASCC and ANSCC were rare (ASR = 0.2 and 0.7 per 100,000 person-years, respectively) and did not change significantly over time except for increasing ANSCCs in men (APC = 2.8%, p<0.001). ICC was the most common HPV-associated cancer (ASR = 19.9 per 100,000 person-years) but declined significantly between 1968–2012 (APC = -2.4%). Incidence of each cancer varied across ethnicities. Similar to trends in Western countries, OPSCC incidence increased in recent years, while non-OP HNC decreased. ICC remains the most common HPV-related cancer in Singapore, but Pap screening programs have led to consistently decreasing incidence. PMID:26720001

Predictors of advanced colorectal neoplasia for colorectal cancer screening.

PubMed

Wong, Martin C S; Lam, Thomas Y T; Tsoi, Kelvin K F; Chan, Victor C W; Hirai, Hoyee W; Ching, Jessica Y L; Sung, Joseph J Y

2014-05-01

The Asia-Pacific Colorectal Screening (APCS) score based on age, gender, family history, and smoking is useful to predict advanced colorectal neoplasia (ACN) in asymptomatic Asian subjects. To evaluate the factors in addition to those of APCS associated with ACN colonoscopic findings. Data from 5,220 asymptomatic subjects aged between 50 and 70 years who underwent screening colonoscopy in a community center between 2008 and 2012 were analyzed. One binary logistic regression analysis was conducted in 2013 with the presence of ACN or cancer as the outcome, controlling for APCS score, alcohol consumption, BMI, hypertension, and other chronic diseases as independent variables. The average participant age was 57.7 years (SD=4.9) and 47.5% were men. Advanced neoplasms or cancers were identified at colonoscopy in 5.6% of all screening participants. From multivariate regression analysis, APCS score≥4 (adjusted OR [AOR]=1.74, 95% CI=1.34, 2.25, p<0.001); overweight (BMI=23-24.9, AOR=1.52, 95% CI=1.12, 2.07, p=0.007); obesity (BMI≥25, AOR=1.56, 95% CI=1.15, 2.10, p=0.004); hypertension (AOR=1.58, 95% CI=1.21, 2.06, p=0.001); and alcohol consumption (AOR=1.47, 95% CI=1.05, 2.06, p=0.025) were associated with ACN. The c-statistic of APCS score alone was 0.560 (95% CI=0.524, 0.595, p=0.001) and that of APCS score plus BMI, hypertension, and alcohol consumption was 0.613 (95% CI=0.578, 0.648, p<0.001). Alcohol consumption, hypertension, and BMI are independent predictors of ACN, which could be incorporated into the APCS for prioritizing Asian asymptomatic subjects for colorectal cancer screening. Copyright © 2014. Published by Elsevier Inc.

Identification of five novel modifier loci of ApcMin harbored in the BXH14 recombinant inbred strain

PubMed Central

Siracusa, Linda D.

2012-01-01

Every year thousands of people in the USA are diagnosed with small intestine and colorectal cancers (CRC). Although environmental factors affect disease etiology, uncovering underlying genetic factors is imperative for risk assessment and developing preventative therapies. Familial adenomatous polyposis is a heritable genetic disorder in which individuals carry germ-line mutations in the adenomatous polyposis coli (APC) gene that predisposes them to CRC. The Apc Min mouse model carries a point mutation in the Apc gene and develops polyps along the intestinal tract. Inbred strain background influences polyp phenotypes in Apc Min mice. Several Modifier of Min (Mom) loci that alter tumor phenotypes associated with the Apc Min mutation have been identified to date. We screened BXH recombinant inbred (RI) strains by crossing BXH RI females with C57BL/6J (B6) Apc Min males and quantitating tumor phenotypes in backcross progeny. We found that the BXH14 RI strain harbors five modifier loci that decrease polyp multiplicity. Furthermore, we show that resistance is determined by varying combinations of these modifier loci. Gene interaction network analysis shows that there are multiple networks with proven gene–gene interactions, which contain genes from all five modifier loci. We discuss the implications of this result for studies that define susceptibility loci, namely that multiple networks may be acting concurrently to alter tumor phenotypes. Thus, the significance of this work resides not only with the modifier loci we identified but also with the combinations of loci needed to get maximal protection against polyposis and the impact of this finding on human disease studies. Abbreviations:APCadenomatous polyposis coliGWASgenome-wide association studiesQTLquantitative trait lociSNPsingle-nucleotide polymorphism. PMID:22637734

Activation and propagation of tumor infiltrating lymphocytes on clinical-grade designer artificial antigen presenting cells for adoptive immunotherapy of melanoma

PubMed Central

Forget, Marie-Andrée; Malu, Shruti; Liu, Hui; Toth, Christopher; Maiti, Sourindra; Kale, Charuta; Haymaker, Cara; Bernatchez, Chantale; Huls, Helen; Wang, Ena; Marincola, Francesco M.; Hwu, Patrick; Cooper, Laurence J. N.; Radvanyi, Laszlo G.

2014-01-01

PURPOSE Adoptive cell therapy (ACT) with autologous tumor infiltrating lymphocytes (TIL) is a therapy for metastatic melanoma with response rates up to 50%. However, the generation of the TIL transfer product is challenging, requiring pooled allogeneic normal donor peripheral blood mononuclear cells (PBMC) used in vitro as “feeders” to support a rapid expansion protocol (REP). Here, we optimized a platform to propagate TIL to a clinical scale using K562-cells genetically modified to express costimulatory molecules such as CD86, CD137-ligand and membrane-bound IL-15 to function as artificial antigen-presenting cell (aAPC) as an alternative to using PBMC feeders. EXPERIMENTAL DESIGN We used aAPC or γ-irradiated PBMC feeders to propagate TIL and measured rates of expansion. The activation and differentiation state was evaluated by flow cytometry and differential gene expression analyses. Clonal diversity was assessed based on pattern of T-cell receptor (TCR) usage. T-cell effector function was measured by evaluation of cytotoxic granule content and killing of target cells. RESULTS The aAPC propagated TIL at numbers equivalent to that found with PBMC feeders, while increasing the frequency of CD8+ T-cell expansion with a comparable effector-memory phenotype. mRNA profiling revealed an up-regulation of genes in the Wnt and stem-cell pathways with the aAPC. The aAPC platform did not skew clonal diversity and CD8+ T cells showed comparable anti-tumor function as those expanded with PBMC feeders. CONCLUSIONS TIL can be rapidly expanded with aAPC to clinical scale generating T cells with similar phenotypic and effector profiles as with PBMC feeders. These data support the clinical-application of aAPC to manufacture TIL for the treatment of melanoma. PMID:25304728

ATP depletion during mitotic arrest induces mitotic slippage and APC/CCdh1-dependent cyclin B1 degradation.

PubMed

Park, Yun Yeon; Ahn, Ju-Hyun; Cho, Min-Guk; Lee, Jae-Ho

2018-04-27

ATP depletion inhibits cell cycle progression, especially during the G1 phase and the G2 to M transition. However, the effect of ATP depletion on mitotic progression remains unclear. We observed that the reduction of ATP after prometaphase by simultaneous treatment with 2-deoxyglucose and NaN 3 did not arrest mitotic progression. Interestingly, ATP depletion during nocodazole-induced prometaphase arrest resulted in mitotic slippage, as indicated by a reduction in mitotic cells, APC/C-dependent degradation of cyclin B1, increased cell attachment, and increased nuclear membrane reassembly. Additionally, cells successfully progressed through the cell cycle after mitotic slippage, as indicated by EdU incorporation and time-lapse imaging. Although degradation of cyclin B during normal mitotic progression is primarily regulated by APC/C Cdc20 , we observed an unexpected decrease in Cdc20 prior to degradation of cyclin B during mitotic slippage. This decrease in Cdc20 was followed by a change in the binding partner preference of APC/C from Cdc20 to Cdh1; consequently, APC/C Cdh1 , but not APC/C Cdc20 , facilitated cyclin B degradation following ATP depletion. Pulse-chase analysis revealed that ATP depletion significantly abrogated global translation, including the translation of Cdc20 and Cdh1. Additionally, the half-life of Cdh1 was much longer than that of Cdc20. These data suggest that ATP depletion during mitotic arrest induces mitotic slippage facilitated by APC/C Cdh1 -dependent cyclin B degradation, which follows a decrease in Cdc20 resulting from reduced global translation and the differences in the half-lives of the Cdc20 and Cdh1 proteins.