Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P10415 (Bcl-2)
 33,771 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Breast cancers lacking estrogen and progesterone receptor expression and Her2 amplification exhibit distinct gene expression profiles and clinical features, and they comprise the majority of BRCA1-associated tumors. Here we demonstrated that the p53 family member p63 controls a pathway for p73-dependent cisplatin sensitivity specific to these "triple-negative" tumors. In vivo, DeltaNp63 and TAp73 isoforms were coexpressed exclusively within a subset of triple-negative primary breast cancers that commonly exhibited mutational inactivation of p53. The DeltaNp63alpha isoform promoted survival of breast cancer cells by binding TAp73 and thereby inhibiting its proapoptotic activity. Consequently, inhibition of p63 by RNA interference led to TAp73-dependent induction of proapoptotic Bcl-2 family members and apoptosis. Breast cancer cells expressing DeltaNp63alpha and TAp73 exhibited cisplatin sensitivity that was uniquely dependent on TAp73. Thus, in response to treatment with cisplatin, but not other chemotherapeutic agents, TAp73 underwent c-Abl-dependent phosphorylation, which promoted dissociation of the DeltaNp63alpha/TAp73 protein complex, TAp73-dependent transcription of proapoptotic Bcl-2 family members, and apoptosis. These findings define p63 as a survival factor in a subset of breast cancers; furthermore, they provide what we believe to be a novel mechanism for cisplatin sensitivity in these triple-negative cancers, and they suggest that such cancers may share the cisplatin sensitivity of BRCA1-associated tumors.
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PMID:The p63/p73 network mediates chemosensitivity to cisplatin in a biologically defined subset of primary breast cancers. 1744 29

Netrins and their receptors deleted in colon cancer (DCC), neogenin, UNC5, and integrins are involved in axon guidance, epithelial morphogenesis, vascular pattering, cancer cell survival, invasion, tumor angiogenesis, and metastasis. Here, we considered the possible contribution of the p53-related apoptosis mediators p63 and p73 in the mechanisms underlying the antagonism between netrin-1 and DCC at the cell death control. We have showed that ectopic expression and external addition of netrin-1 in HeLa and HEK-293 cells with inactive p53 lead to impaired cell viability and induction of apoptosis. These responses were associated with up-regulation of the proapoptotic protein TAp73alpha, decreased Bcl-2/Bax ratio, and caspase-3 cleavage, with no change in protein levels of the antiapoptotic NH(2)-terminal-truncated DeltaNp73alpha isoform, p73 adapter Yap-1 and p73 E3 ubiquitin ligase Itch, and p63, as well as the transcripts encoding p63, TAp73alpha, and DeltaNp73alpha. However, the proteasome inhibitor MG132 potentiated, while DCC counteracted, netrin-1-induced TAp73alpha. Consistently, netrin-1 expression correlated with stabilization of the TAp73alpha protein and lower levels of TAp73alpha ubiquitination that was conversely enhanced by DCC, in a netrin-dependent manner. Our data indicate that netrin-1 selectively up-regulates TAp73alpha by preventing its ubiquitination and degradation. Targeted repression of p73alpha by shRNA reversed TAp73alpha and the apoptosis induced by netrin-1, and exacerbated the growth of HeLa tumor xenografts. Apoptosis induced by cisplatin was markedly enhanced in netrin-1 or DCC-expressing cells. Collectively, our data reveal that the transcriptionally active TAp73alpha tumor suppressor is implicated in the apoptosis induced by netrin-1 in a p53-independent and DCC/ubiquitin-proteasome dependent manner.
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PMID:Netrin-1 induces apoptosis in human cervical tumor cells via the TAp73alpha tumor suppressor. 1892 94

Doxorubicin is an important component of combination therapy for muscle-invasive urinary bladder cancer. Treatment with this topoisomerase II poison is able to interfere with cell cycle progression and lead to cancer cell death. Using FACS analysis, Western immunoblotting and semi-quantitative RT-PCR, we studied the effects of doxorubicin on cell cycle progression and apoptosis, and also explored the possibility of using groups of genes as biomarkers of prognosis and/or response to doxorubicin treatment in human urinary bladder cancer cells. Doxorubicin induced dose-dependent G2/M and/or G1/S cell cycle arrest, followed by grade- and dose-dependent reduction in the amount of the cytosolic trimeric form of FasL, activation of Caspase-8, Caspase-9, Caspase-3, cleavage of PARP, Lamin A/C, Bcl-XL/S and interestingly Hsp90, and finally cell death. Data presented here also suggest the use of the expression patterns of Cyclin-E2, Cyclin-F, p63, p73, FasL, TRAIL, Tweak, Tweak-R, XAF-1, OPG and Bok genes for identification of the differentiation grade, and Cyclin-B2, GADD45A, p73, FasL, Bik, Bim, TRAIL, Fas, Tweak-R, XAF-1, Bcl-2, Survivin, OPG, DcR2 and Bcl-XL genes for the detection of response to doxorubicin in human bladder cancer cells.
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PMID:Grade-dependent effects on cell cycle progression and apoptosis in response to doxorubicin in human bladder cancer cell lines. 1908 86

High-level expression of Bcl-2 associated athanogene (BAG-1) protects cancer cells from stress-induced cell death and growth inhibition. These protective effects of BAG-1 are dependent on interactions with the HSC70 and HSP70 chaperones. However, the key stress-response molecules that are regulated by a BAG-1/chaperone mechanism have not been identified. In this study, we investigated the effects of BAG-1 overexpression on the function of p53 family proteins, p53, p63 and p73. Overexpression of BAG-1 isoforms interfered with the transactivating activity of p73 and p63, but had modest and variable effects on p53-dependent transcription. p73 and BAG-1 interacted in intact cells and overexpression of BAG-1 decreased the expression of p73. siRNA-mediated ablation of endogenous BAG-1 increased the activity of a p73-responsive promoter and this was reversed by knock-down of p73. The ability of BAG-1 to modulate p73 activity and expression, and to interact with p73 were dependent on amino acid residues required for the interaction of BAG-1 with HSC70 and HSP70. These results show that BAG-1 inhibits the transactivating functions of p73 and provide new insight into the mechanisms that control the expression of p73. Inhibition of p73 function may be one mechanism that contributes to the pro-survival activity of BAG-1.
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PMID:The BAG-1 cochaperone is a negative regulator of p73-dependent transcription. 1929 98

Carcinomas arising in or from the epithelial component of preexisting parotid Warthin tumors (WTs) are rare; the other histologic types of carcinoma found to arise from WTs are adenocarcinoma not otherwise specified, undifferentiated, mucoepidermoid, squamous cell, and oncocytic. The aim of this study is to describe the clinicopathologic features of a distinct salivary gland neoplasm, previously undescribed, with a striated duct phenotype arising from WT. We have designated this neoplasm "Warthin adenocarcinoma" (WA). In this retrospective study, we searched the surgical pathology files of the Department of Pathology at The University of Texas M.D. Anderson Cancer Center for cases of malignant WT and salivary adenocarcinoma not otherwise specified diagnosed from January 1, 1985, through December 31, 2006, and evaluated patients' medical records and pathologic material. We obtained tissue sections and immunohistochemically stained them with antibodies against p63; Bcl-2; cytokeratin (CK)903, CK7, CK14, and CK18; antimitochondrial antibody (AMA); smooth muscle actin; calponin; S-100; and Ki-67. We identified 2 cases of WA; both patients were women, 44 and 60 years of age, with 4.0- and 4.5-cm tumors in the left parotid gland. Histologically, the tumors were composed of bilayered duct-like structures: The inner layer was formed by a single row of columnar oxyphilic cells expressing CK7, CK14, CK18, and AMA. The outer layer was composed of multiple layers of small round dark cells with scanty cytoplasm that expressed p63, Bcl-2, and CK903 and were focally positive for AMA and negative for myoepithelial markers. The Ki-67 proliferative indices were 20%; and 25%. A residual WT with transition to carcinoma was identified in both cases. Treatment had consisted of total parotidectomy with postoperative irradiation. Patients were free of disease 1 and 3 years after treatment. Warthin adenocarcinoma is a unique salivary gland carcinoma representing the malignant epithelial counterpart of WT. The identification of additional cases would help to better elucidate the line of differentiation of the tumor and further define its natural history.
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PMID:Warthin adenocarcinoma: analysis of 2 cases of a distinct salivary neoplasm. 1943 1

We investigated the downstream mechanisms by which chemotherapeutic drugs elicit apoptosis in hepatocellular carcinoma (HCC). Genomic signatures of HCC cell lines treated with different chemotherapeutic drugs were obtained. Analyses of apoptosis pathways were performed and RNA interference was used to evaluate the role of the p53 family. Endogenous p53, p63 and p73 were upregulated in response to DNA damage by chemotherapeutic drugs. Blocking p53 family function led to chemoresistance in HCC. Stimulation and blocking experiments of the CD95-, the TNF- and the TRAIL-receptor systems revealed that cytotoxic drugs, via the p53 family members as transactivators, can trigger expression of each of these death receptors and consequently sensitize HCC cells toward apoptosis. Furthermore, our findings demonstrate a link between chemotherapy, the p53 family and the mitochondrial apoptosis pathway in HCC. Chemotherapeutic treatment induces expression of proapoptotic Bcl-2 family members like Bax and BCL2L11 and the expression of Apaf1, BNIP1, Pdcd8 and RAD. Thus, upon DNA damage, p53, p63 and p73 promote apoptosis via the extrinsic and the intrinsic signaling pathway. In addition, not only proapoptotic genes were upregulated, but also genes known to exert antiapoptotic functions. Bleomycin-induced upregulation of BCL-XL/BCLXL1 and MDM2 suggests that it is the ratio of proapoptotic and antiapoptotic proteins that regulates the apoptosis response of HCC cells toward chemotherapy, thereby playing a decisive role between treatment sensitivity vs. drug resistance. The clinical importance of these data is evidenced by our finding that the bleomycin target gene signature can predict the prognosis of patients suffering from HCC.
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PMID:Chemotherapy-induced apoptosis in hepatocellular carcinoma involves the p53 family and is mediated via the extrinsic and the intrinsic pathway. 1971 44

Giant cell tumour of bone (GCTB) is a primary tumour of bone that may rarely, in the absence of malignant cytological features, produce metastatic lesions, most commonly in the lungs. Whether these lung nodules represent true neoplastic secondaries or implants derived from the primary tumour is not certain. In this study, we have analysed the morphological and immunophenotypic features of 19 conventional GCTBs and corresponding lung nodules for expression of macrophage, osteoclast, proliferation and tumour-associated markers. A striking morphological feature of all GCTBs that produced lung secondaries was the presence of large areas of haemorrhage and thrombus formation; mononuclear and multinucleated cells of GCTB were frequently found within these areas of haemorrhage and thrombus. A similar pattern of CD14, CD33, HLA-DR and CD51 expression was seen in macrophages and giant cells in primary and secondary tumours. Smooth muscle actin expression was frequently noted in primary GCTBs that recurred and metastasised. No difference was seen in the expression of p53, p63, Ki-67, cyclin D1 or Bcl-2 in primary and secondary tumours. Our findings suggest that most lung nodules associated with primary conventional GCTBs are implants derived from tumour emboli formed in areas of haemorrhage and thrombus formation within the primary tumour.
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PMID:Morphological and immunophenotypic features of primary and metastatic giant cell tumour of bone. 2001 88

Pleomorphic carcinoma of the breast is considered a rare variant of high-grade ductal NOS carcinoma (NOS-IDC), and the prognosis is poor. However, its clinicopathologic features are not well-characterized. Using the criteria delineated in the World Health Organization breast tumor classification of 2003, ten cases of pleomorphic carcinoma were identified from 9794 NOS-IDC in our archived materials that were originally diagnosed as high-grade infiltrating ductal carcinoma of breast. To investigate the clinicopathologic characteristics and to elucidate the histologic diagnosis and differential diagnosis of this entity, we reviewed the pathology manifestations and clinical features of these cases and examined the tumor expression of ER, PR, PCNA, AE(1)/AE(3), p53, S-100, C-erbB-2, EMA, p63, and Bcl-2 by immunohistochemistry.
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PMID:Clinicopathologic characteristics of pleomorphic carcinoma of the breast. 2001 46

The androgen receptor (AR) is expressed in differentiated secretory prostate epithelial cells in vivo. However, in the human prostate, it is unclear whether androgens directly promote the survival of secretory cells, or whether secretory cells survive through androgen-dependent signals from the prostate stroma. Biochemical and mechanistic studies have been hampered by inadequate cell-culture models. In particular, large-scale differentiation of prostate epithelial cells in culture has been difficult to achieve. Here, we describe the development of a differentiation system that is amenable to functional and biochemical analysis and its application to deciphering the survival pathways in differentiated AR-expressing epithelial cells. Confluent prostate epithelial cell cultures were treated with keratinocyte growth factor (KGF) and dihydrotestosterone. After 2 weeks, a suprabasal cell layer was formed in which cells no longer expressed alpha2, alpha3, alpha6, alphav, beta1 or beta4 integrins or p63, K5, K14, EGFR, FGFR2IIIb or Bcl-2, but instead expressed AR and androgen-induced differentiation markers, including K18, K19, TMPRSS2, Nkx3.1, PMSA, KLK2 and secreted prostate-specific antigen (PSA). Differentiated prostate cell survival depended on E-cadherin and PI3K, but not KGF, androgen, AR or MAPK. Thus survival of differentiated prostate epithelial cells is mediated by cell-cell adhesion, and not through androgen activity or prostate stroma-derived KGF.
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PMID:E-cadherin-mediated survival of androgen-receptor-expressing secretory prostate epithelial cells derived from a stratified in vitro differentiation model. 2004 43

p63 belongs to the family of p53-related transcription factors expressing a variety of isoforms. The Trp63 gene has two promoters that drive the expression of two major p63 isoform subfamilies. Isoforms of the TAp63 subfamily show pro-apoptotic activities, whereas members of the N-terminally truncated (DeltaN) p63 subfamily have anti-apoptotic functions. We have previously shown an important role for TAp63alpha in the induction of apoptosis and chemosensitivity of hepatocellular carcinoma (HCC). Here, we investigated the molecular mechanisms accounting for the oncogenic role of DeltaNp63alpha in HCC. DeltaNp63alpha can directly interfere with the transcriptional activation function of the TA (containing the transactivation domain) isoforms of the p53 family and consequently inhibit transactivation of pro-apoptotic target genes. DeltaNp63alpha negatively regulates the genes encoding for the death receptor CD95 and the pro-apoptotic Bcl-2 family member BAX. Thus, DeltaNp63alpha expression in HCC interferes with both the death receptor and the mitochondrial apoptosis activity of the TA isoforms. In addition and of clinical relevance, DeltaNp63alpha inhibits activation of p53 family target genes and apoptosis induced by chemotherapeutic drugs. Chemotherapeutic treatment induces expression of Bax, Bim, Noxa, Puma and Perp; this is antagonized by DeltaNp63alpha. Our data suggest that the DeltaNp63alpha isoform represses apoptosis-related genes of the extrinsic and intrinsic apoptosis signaling pathways, thereby contributing to chemoresistance of HCC.
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PMID:Dominant negative (DeltaN) p63alpha induces drug resistance in hepatocellular carcinoma by interference with apoptosis signaling pathways. 2040 33


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