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)

Following breast-conserving surgery for ductal carcinoma in situ (DCIS), the presence of comedo necrosis reportedly predicts for higher rates of post-operative recurrence. To examine the role of programmed cell death (apoptosis) in the aetiology of the cell death described as comedo necrosis, we studied 58 DCIS samples, using light microscopy, for morphological evidence of apoptotic cell death. The percentage of apoptotic cells (apoptotic index, AI) was compared between DCIS with and without evidence of 'comedo necrosis' and related to the immunohistochemical expression of the anti-apoptosis gene bcl-2, mitotic index (MI), the cellular proliferation antigen Ki67, nuclear grade and oestrogen receptor (ER) status. AI was significantly higher in DCIS samples displaying high-grade comedo necrosis than in low-grade non-comedo samples: median AI = 1.60% (range 0.84-2.89%) and 0.45% (0.1-1.31%) respectively (P < 0.001). Increasing nuclear grade correlated positively with AI (P < 0.001) and negatively with bcl-2 expression (P = 0.003). Bcl-2 correlated negatively with AI (P = 0.019) and strongly with ER immunoreactivity (P < 0.001). Cellular proliferation markers (MI and Ki67 immunostaining) correlated strongly with AI and were higher in comedo lesions and tumours of high nuclear grade (P < 0.001 in all cases). Thus, apoptosis contributes significantly to the cell death described in ER-negative, high-grade DCIS in which a high proliferative rate is associated with a high apoptotic rate. It is likely that dysregulation of proliferation/apoptosis control mechanisms accounts for the more malignant features typical of ER negative comedo DCIS.
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PMID:Evidence of significant apoptosis in poorly differentiated ductal carcinoma in situ of the breast. 974 2

Apoptosis is a frequent phenomenon in breast cancer and it can be detected by light microscopy in conventional histopathological sections or by special staining techniques. The number of apoptotic cells as a percentage of cells present, or the number of apoptotic cells per square millimetre of neoplastic tissue, is usually described as the apoptotic index (AI). In breast cancer, the AI is not related to tumour size, axillary lymph node metastasis or distant metastasis at diagnosis. It is greater in invasive ductal carcinomas than in other histological types. High AI is also related to high histological grade, high nuclear grade, comedo-type necrosis, lack of tubule formation, and dense infiltration of the tumour by lymphocytes. Sex steroid receptor-negative tumours have greater AIs than the sex steroid receptor-positive ones. Aneuploid breast cancers with high S-phase fractions (SPFs) also have high AI values compared with diploid tumours with low SPFs. p53-Positive breast cancers have high AIs, whereas tumours that are Bcl-2 positive have low AIs. The AI shows a strong positive correlation to all direct or indirect indicators of cell proliferation, such as mitotic index and Ki67 immunolabelling. Univariate survival analyses show that a high AI is linked with unfavourable disease outcome in axillary lymph node-negative and -positive breast cancer, but multivariate analyses indicate that AI is not an independent prognostic factor. In conclusion, a high AI is related to malignant cellular features and indicators of invasiveness and cell proliferation in breast cancer.
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PMID:Apoptosis in breast cancer: relationship with other pathological parameters. 1073 80

In the multistep progressive pathogenesis of human breast cancer, comedo ductal carcinoma in situ (DCIS) represents a preinvasive precursor lesion for therapy resistant invasive cancer. Human tissue derived cell culture models exhibiting molecular similarities to clinical DCIS facilitate an important preclinical mechanistic approach for evaluation of preventive efficacy of natural and synthetic chemopreventive compounds. Natural phytochemicals present in fresh fruits, vegetables and grain products are likely to offer protection against cancer. The clinical efficacy of these natural phytochemicals, however, depends on extrapolation, and is therefore equivocal. The present study determined whether the natural soy isoflavone genistein (GEN) inhibited aberrant proliferation in 184-B5/HER cells (a model for human comedo DCIS) and identified possible mechanisms responsible for its efficacy. Human reduction mammoplasty derived HER-2/neu oncogene expressing preneoplastic 184-B5/HER cells represented the experimental system. Flow cytometry and cellular epifluorescence based assays were utilized to quantitate the alterations in cell cycle progression, cellular apoptosis, and in the status of cell cycle regulatory and apoptosis-associated gene product expression. The 184-B5/HER cells exhibited specific immunofluorescence to p185HER, p53, EGFR, but not to ERalpha, thus resembling comedo DCIS. Treatment of 184-B5/HER cells with GEN resulted in a dose-dependent decrease in the viable cell population, increase in the G0/G1:S + G2/M ratio and enhancement of sub G0/G1 (apoptotic population). Exposure to the maximum cytostatic 10 microM dose of GEN down-regulated HER-2/neu mediated signal transduction as evidenced by a 73.9% decrease (p=0.001) in p185HER specific, and a 89.8% decrease (p=0.001) in phosphotyrosine specific immunofluorescence. The increase in G0/G1:S + G2/M ratio in response to the treatment with 10 microM GEN was associated with a 85.5% decrease (p=0.001) in immunoreactivity to PCNA and a 128.6% increase (p=0.004) in immunoreactivity to the cyclin dependent kinase inhibitor p16INK4. The induction of apoptosis by GEN was associated with a 52.8% decrease (p=0.001) in the immunoreactivity to antiapoptotic Bcl-2 and with a 195.9% (p=0.001) increase in the immunoreactivity to proapoptotic Bax. Thus, preventive efficacy of GEN in HER-2/neu+/ER- 184-B5/HER cells may be due to its ability to down-regulate HER-2/neu mediated signal transduction, increase the expression of the cyclin dependent kinase inhibitor p16INK4, and induce Bcl-2 dependent apoptosis. These data provide evidence that GEN may be a potential chemopreventive lead compound for human comedo DCIS. The 184-B5/HER cells, may therefore, provide a high throughput mechanistic bioassay to identify new chemopreventive agents for human breast cancer.
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PMID:Soy isoflavone genistein modulates cell cycle progression and induces apoptosis in HER-2/neu oncogene expressing human breast epithelial cells. 1223 20

Comedo-DCIS is a histologic subtype of preinvasive breast neoplasia that is characterized by prominent apoptotic cell death and has greater malignant potential than other DCIS subtypes. We investigated the mechanisms of apoptosis in comedo-DCIS and its role in conversion of comedo-DCIS to invasive cancer. Clinical comedo-DCIS excisions and the MCF10DCIS.com human breast cancer model which produces lesions resembling comedo-DCIS were analyzed. Apoptotic luminal and myoepithelial cells were identified by TUNEL and reactivity to cleaved PARP antibody and cell death assessed by Western blotting, Mitocapture and immunohistochemical assays. MCF10DCIS.com cells undergo spontaneous apoptosis in vitro, both in monolayers and multicellular spheroids; it is associated with increased mitochondrial membrane permeability, increase in Bax/Bcl-2 ratio and occurs via caspase-9-dependent p53-independent pathway. This suggests that apoptosis is stromal-independent and that the cells are programmed to undergo apoptosis. Immunostaining with cleaved PARP antibody showed that myoepithelial apoptosis occurs before lesions progress to comedo-DCIS in both clinical comedo-DCIS and in vivo MCF10DCIS.com lesions. Intense staining for MMP-2, MMP-3, MMP-9 and MMP-11 was observed in the stroma and epithelia of solid DCIS lesions prior to conversion to comedo-DCIS in clinical and MCF10DCIS.com lesions. Gelatin zymography showed higher MMP-2 levels in lysates and conditioned media of MCF10DCIS. com cells undergoing apoptosis. These data suggest that signals arising from the outside (microenvironmental) and inside (internal genetic alterations) of the duct act in concert to trigger apoptosis of myoepithelial and luminal epithelial cells. Our findings implicate spontaneous apoptosis in both the etiology and progression of comedo-DCIS. It is possible that spontaneous apoptosis facilitates elimination of cells thus permitting expansion and malignant transformation of cancer cells that are resistant to spontaneous apoptosis.
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PMID:Comedo-ductal carcinoma in situ: A paradoxical role for programmed cell death. 1878 17