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)

The expression of apoptosis suppressing protein bcl-2, tumour-suppressor protein p53, and proliferation marker Ki-67 and their possible prognostic value were analysed in pancreatic ductal adenocarcinoma. Fifty-two % (34/64) of the samples were positive for bcl-2 and immunostaining were mainly localized in the cytoplasm of tumour cells. Bcl-2 expression was not related to tumour grade, DNA ploidy or S-phase fraction or to any clinical parameters. In univariate analysis bcl-2 expression predicted favourable outcome (p = 0.008). Positive nuclear staining for p53 was found in 40% (24/59) of samples and 80% (60/74) of the tumours were positive for Ki-67. p53 and Ki-67 expressions were not related to patient survival. According to our results, bcl-2 expression seems to be a predictor of disease outcome and may have some clinical value in human pancreatic cancer.
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PMID:Clinical contribution of bcl-2, p53 and Ki-67 proteins in pancreatic ductal adenocarcinoma. 956 86

The growth of a tumour can be determined by an interplay between cell proliferation and loss. The expression of apoptosis-related proteins (Bcl-2 and p53), cell proliferation (Ki-67), and apoptotic cell death were investigated using immunohistochemistry and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labelling in gastric neoplams, to evaluate whether they correlate with the morphology of the tumour. The materials included ten cases of gastric adenoma and 40 cases of early gastric carcinoma consisting of differentiated adenocarcinomas (n = 20) and undifferentiated carcinomas (n = 20). All cases of adenoma and eight cases of differentiated adenocarcinoma were of the elevated type, while 12 differentiated adenocarcinomas and all of the undifferentiated carcinomas were of the depressed type. The diffuse expression of Bcl-2 was observed in all cases of adenoma and seven out of eight (88 per cent) of elevated-type differentiated adenocarcinoma. In contrast, Bcl-2 expression was absent or focal in the depressed type of carcinoma. Overexpression of p53 was found exclusively in the depressed type of carcinoma. Thus, Bcl-2 and p53 expression was associated with tumour morphology. It seemed unlikely that Bcl-2 and p53 expression was involved in the morphogenesis of the gastric tumours through inhibiting apoptotic cell death, since the degree of apoptosis in Bcl-2-positive gastric tumours was rather higher than that in Bcl-2-negative ones and it did not differ significantly between p53-positive and p53-negative tumours. Instead, the diffuse distribution of Bcl-2 correlated with the superficial distribution of Ki-67-positive proliferating cells, and the overexpression of p53 had a tendency to correlate with the diffuse distribution of proliferating cells. These results suggest that diffuse Bcl-2 expression and a superficial distribution of proliferating cells may contribute to the elevated configuration, and that overexpression of p53 and a diffuse distribution of proliferating cells may result in the depressed configuration in the relatively early stages of gastric tumourigenesis.
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PMID:Expression of Bcl-2 and p53 correlates with the morphology of gastric neoplasia. 966 3

Cisplatin exerts its cytotoxicity by inducing apoptosis. Similarly, all-trans retinoic acid (ATRA) causes apoptosis in certain cells. We studied the interaction of cisplatin and ATRA in human ovarian adenocarcinoma cells 2008, in human head and neck squamous carcinoma cells UMSCC10b, and in their respective cisplatin-resistant sub-lines. ATRA enhanced the cytotoxicity of cisplatin. The interaction of the drugs was synergistic in combination index-isobologram analyses (combination index >0.5 at 50% cell survival) in all of the cell lines tested. ATRA inhibited the cellular accumulation of the cisplatin analogue [3H] cis-dichloroethylenediamineplatinum(II) by 22-33% in three of four cell lines tested but did not alter the cellular content of reduced glutathione. The expression of Bcl-2 relative to Bax decreased more after combined treatment with cisplatin and ATRA than after either drug alone. The apoptotic mechanism of cell death was confirmed by demonstrating cleavage of poly(ADP-ribose)polymerase and by morphological analysis. The combined treatment with ATRA and cisplatin induced apoptosis in significantly more cells than either drug alone. We conclude that ATRA enhances the cytotoxicity of cisplatin by facilitating apoptosis in ovarian and head and neck carcinoma cells.
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PMID:all-trans retinoic acid enhances cisplatin-induced apoptosis in human ovarian adenocarcinoma and in squamous head and neck cancer cells. 981 94

Bax and Bcl-2 are proteins that regulate programmed cell death and apoptosis. The expression of these proteins can be regulated, at least in part, by the tumor suppressor p53, but the effects of p53 are highly tissue specific. In an effort to better understand the relation between p53 and the in vivo control of the expression of Bax and Bcl-2 in adenocarcinomas of the breast, we evaluated by immunohistochemistry the expression of Bcl-2 and Bax in 149 invasive ductal carcinomas, 135 of which were chosen because of their p53 immunopositivity. The percentages of Bcl-2-immunopositive tumor cells were significantly lower in the p53-positive (median 20%) subsets as compared to the p53-negative (median 85%) subsets (P = 0. 004). Comparisons of the percentages of p53-immunopositive tumor cells with the percentages of Bcl-2- and Bax-positive cells (as continuous variables) revealed a significant inverse correlation between Bcl-2 and p53 (r = -0.41, P < 0.001) but not between Bax and p53. In the p53-positive subset, the percentages of Bax- and Bcl-2-immunopositive tumor cells were correlated positively (r = 0. 27, P = 0.002), suggesting that the expression of these genes may be co-regulated to some extent in these breast cancers. Higher percentages of Bcl-2-positive tumor cells were also associated with estrogen receptor positivity (P = 0.03), low histological tumor grade (P = 0.03), and low T stage (P = 0.02), whereas Bax immunostaining was associated only with c-erbB-2 immunopositivity (P = 0.02). Although the number of cases was small and treatment was non-uniform, preliminary correlations with clinical outcome data suggest that the prognostic significance of Bcl-2 may be enhanced by inclusion of Bax data in patients with p53-immunopositive adenocarcinoma of the breast, at least for patients with node-negative disease. Taken together, these data suggest that, despite the ability of p53 to bind directly to the Bax gene promoter, the regulation of Bax in human breast cancers does not necessarily correlate with p53 status, implying that regulation of this pro-apoptotic gene in these tumors is complex and probably influenced by several factors.
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PMID:Analysis of Bax and Bcl-2 expression in p53-immunopositive breast cancers. 1004 37

Programmed cell death (PCD) is a genetically regulated pathway that is altered in many cancers. This process is, in part, regulated by the ratio of PCD inducers (Bax) or inhibitors (Bcl-2). An abnormally high ratio of Bcl-2 to Bax prevents PCD, thus contributing to resistance to chemotherapeutic agents, many of which are capable of inducing PCD. Non-small cell lung cancer (NSCLC) cells demonstrate resistance to these PCD-inducing agents. If Bcl-2 prevents NSCLC cells from entering the PCD pathway, then reducing the amount of endogenous Bcl-2 product may allow these cells to spontaneously enter the PCD pathway. Our purpose was to determine the effects of bcl-2 antisense treatment on the levels of programmed cell death in NSCLC cells. First, we determined whether bcl-2 and bax mRNA were expressed in three morphologically distinct NSCLC cell lines: NCI-H226 (squamous), NCI-H358 (adenocarcinoma), and NCI-H596 (adenosquamous). Cells were then exposed to synthetic antisense bcl-2 oligonucleotide treatment, after which programmed cell death was determined, as evidenced by DNA fragmentation. Bcl-2 protein expression was detected immunohistochemically. All three NSCLC cell lines expressed both bcl-2 and bax mRNA and had functional PCD pathways. Synthetic antisense bcl-2 oligonucleotide treatment resulted in decreased Bcl-2 levels, reduced cell proliferation, decreased cell viability, and increased levels of spontaneous PCD. This represents the first evidence that decreasing Bcl-2 in three morphologically distinct NSCLC cell lines allows the cells to spontaneously enter a PCD pathway. It also indicates the potential therapeutic use of antisense bcl-2 in the treatment of NSCLC.
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PMID:Antisense bcl-2 treatment increases programmed cell death in non-small cell lung cancer cell lines. 1021 15

The grading of dysplasia in Barrett's esophagus has prognostic importance, however observer variation limits the reliability of simple histological analysis alone. We investigated Ki-67, p53 and Bcl-2 expression in Barrett's esophagus, in the sequence from Barrett's low-grade dysplasia to high-grade dysplasia and infiltrating adenocarcinoma. Forty-four esophagectomy specimens were utilized: 39 specimens with esophageal dysplasia and adenocarcinoma and 5 specimens with esophageal dysplasia only. This gave 83 sections (2 sections for specimens with dyplasia and carcinoma) examined from 44 patients. The sections were examined for Ki-67, p53 and Bcl-2 reactivity by immunohistochemistry. Low-grade dysplasia was present in 14 sections, high-grade dysplasia in 30 sections and carcinoma in 39 sections. Ki-67 expression occurred in 2 out of 14 (14%) sections with low-grade dysplasia, in 22 out of 30 (73%) sections with high-grade dysplasia and in 34 out of 39 (87%) sections with carcinoma (p<0.001). p53 protein expression was found in 1 of 14 (7%) sections with low-grade dysplasia, in 18 of 30 (60%) sections with high-grade dysplasia and in 33 of 39 (85%) sections with carcinoma (p<0.001). Expression of Bcl-2 was found in 11 of 14 (84%) sections with low-grade dysplasia but immunoreactivity was not seen in any section with high-grade dysplasia or Barrett's carcinoma. Our results indicate that overexpression of Ki-67, Bcl-2 protein and p53 mutations can be identified as early events during neoplastic progression in Barrett's esophagus. These data support the hypothesis that, in the progression of Barrett's metaplasia to adenocarcinoma, the balance of proliferation/apoptosis plays an important role.
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PMID:Analysis of Ki-67, p53 and Bcl-2 expression in the dysplasia-carcinoma sequence of Barrett's esophagus. 1037 74

The p53 tumor suppressor gene and the Bcl-2 proto-oncogene regulate cell cycle progression and apoptosis. We evaluated the expression of these molecular markers with standard pathologic prognostic variables in patients who received multimodality therapy for resectable adenocarcinoma of the pancreas to study the effect of p53 and Bcl-2 on survival duration. Immunohistochemical staining of archival material was performed to determine levels of expression of p53 and Bcl-2 proteins in 70 patients with adenocarcinoma of pancreatic origin. All patients underwent a potentially curative pancreaticoduodenectomy and standardized pathologic analysis of resected specimens. Potential pathologic and molecular prognostic variables were assessed for their effect on survival duration. Nuclear staining for p53 was observed in 33 (47%) of 70 specimens. Immunostaining for Bcl-2 was observed in 23 specimens (33%). A trend toward improved survival duration was seen in patients whose tumors stained positive for either p53 or Bcl-2. Negative staining for both markers predicted short survival (P = 0.01). By univariate and multivariate analyses, no single pathologic factor was associated with survival duration. Immunohistochemical staging using both p53 and Bcl-2 significantly predicted survival duration by univariate and multivariate analysis; patients whose tumors stained positively for p53 and/or overexpressed Bcl-2 had a significantly longer survival than those whose tumors stained negative for both proteins.
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PMID:Prognostic factors in resectable pancreatic cancer: p53 and bcl-2. 1048 Nov 19

The mammalian colon develops from a simple tube of undifferentiated cells into a complex, highly ordered organ, with a continuously self-renewing epithelial layer. We have previously described c-Myb expression in the epithelia of murine and human colon crypts and documented increased expression in colorectal adenocarcinoma cells. To investigate the role of c-Myb in colonic epithelium development, we have used embryos with a disrupted c-myb gene. Prior to the in utero death of these embryos at E15, we excised colon tissue and transplanted it under the kidney capsule of recipient mice to allow further development and cyto-differentiation. Compared to the colons of wildtype and heterozygous littermates, the c-myb homozygous knockout colon is highly irregular with a disordered epithelium and abnormal crypts. In addition, the expression of Bcl-2, a known target of c-Myb, is reduced and apoptosis is increased, indicating a critical requirement for c-Myb in normal colon development.
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PMID:c-Myb is critical for murine colon development. 1052 63

Pancreatic cancer is the fifth leading cause of cancer related deaths in the United States. Despite many recent advances in the treatment modalities, the mortality rate still remains very high. Paclitaxel (Taxol) and Caffeine have been used for the treatment of this disease, however the molecular mechanisms of these agents are not fully understood, which may be partly responsible for the failure of these agents in the treatment of pancreatic cancer. Human pancreatic adenocarcinoma cell lines, HPAC and PANC-1 containing wild-type and mutant p53 respectively, were used to investigate the effects of Taxol and Caffeine on cell growth, and their effects on the modulation of cell cycle and apoptosis related genes. Protein extracts from these cells treated with 100 nM of Taxol or 4 mM of Caffeine were subjected to Western blot analysis for this study. Drug treated cells were also analyzed to calculate the number of cells undergoing apoptosis. Dose and time dependent growth inhibition was observed in both PANC-1 and HPAC cells when treated with either Taxol or Caffeine. Western blot analysis showed an up-regulation of p21WAF1 in both cell lines treated with either Taxol or Caffeine. Furthermore, down-regulation of cyclin B and cdk1 was observed in Taxol and Caffeine treated HPAC cells. However, the results were drastically different in PANC-1 cells where cyclin B was down regulated only by Caffeine treatment and the level of cdk1 protein was undetectable in this cell line. Moreover, up-regulation of p53 and down-regulation of Bcl-2 was observed only in HPAC cells treated with Taxol. Apoptotic cell death analysis showed increasing number of cells undergoing apoptosis between 24 and 48 h of Caffeine treatment, however only Taxol showed greater than 50% cells under-going apoptosis only in HPAC cells. The up-regulation of p21WAF1 and down-regulation of cyclin B and cdk1 suggest their possible roles in G2/M cell cycle arrest caused by both Taxol and Caffeine as reported earlier. From these results we conclude that the differential molecular changes observed in this study may determine the cellular effects of these agents on pancreatic adenocarcinoma cells and that the effects of chemotherapeutic agents may be determined by the endogenous status of p53 mutation and, in turn, may determine the therapeutic effects of these agents in the treatment of pancreatic cancer.
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PMID:Molecular effects of taxol and caffeine on pancreatic cancer cells. 1053 72

Bcl-2 is an anti-apoptotic and anti-proliferative protein over-expressed in several different human cancers including breast. Gain of Bcl-2 function in mammary epithelial cells was superimposed on the WAP-TAg transgenic mouse model of breast cancer progression to determine its effect on epithelial cell survival and proliferation at three key stages in oncogenesis: the initial proliferative process, hyperplasia, and cancer. During the initial proliferative process, Bcl-2 strongly inhibited both apoptosis and mitotic activity. However as tumorigenesis progressed to hyperplasia and adenocarcinoma, the inhibitory effects on mitotic activity were lost. In contrast, anti-apoptotic activity persisted in both hyperplasias and adenocarcinomas. These results demonstrate that the inhibitory effect of Bcl-2 on epithelial cell proliferation and apoptosis can separate during cancer progression. In this model, retention of anti-apoptotic activity with loss of anti-proliferative action resulted in earlier tumor presentation.
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PMID:Loss of anti-mitotic effects of Bcl-2 with retention of anti-apoptotic activity during tumor progression in a mouse model. 1059 63


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