Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0006142 (breast cancer)
 160,383 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Aberrant inhibition of programmed cell death (apoptosis) prevents normal homeostasis and promotes tissue tumorigenesis, but whether it also influences the outcome of common cancers has remained arguable. The expression of a novel IAP apoptosis inhibitor, survivin, in breast cancer and its association with tumor cell apoptosis and overall prognosis were examined in this study. Immunohistochemical analysis showed that survivin expression was positive in 118 of 167 cases (70.7%) of breast carcinomas of histological stages I to IH. In contrast, no expression of survivin in adjacent normal tissue was detected. Although survivin expression was not correlated with p53 mutations, survivin-positive cases were strongly associated with bcl-2 expression (78.0% versus 47.5%; P = 0.0005) and reduced apoptotic index (0.62% +/- 0.51% versus 1.27% +/- 1.37%; P < 0.0001). In addition, patients with low apoptotic index (<0.52%) had worse survival rates than the group with high apoptotic index (> or =0.52%; P = 0.028), and multivariate Cox proportional hazard model analysis identified apoptotic index as an independent prognostic factor (P = 0.024). The results suggest that apoptosis inhibition by survivin, alone or in cooperation with bcl-2, is a significant prognostic parameter of worse outcome in breast carcinoma.
 ...
PMID:Expression of survivin and its relationship to loss of apoptosis in breast carcinomas. 1065 40

Progesterone inhibits the proliferation of normal breast epithelial cells in vivo, as well as breast cancer cells in vitro. But the biologic mechanism of this inhibition remains to be determined. We explored the possibility that an antiproliferative activity of progesterone in breast cancer cell lines is due to its ability to induce apoptosis. Since p53, bcl-2 and survivin genetically control the apoptotic process, we investigated whether or not these genes could be involved in the progesterone-induced apoptosis. We found a maximal 90% inhibition of cell proliferation with T47-D breast cancer cells after exposure to 10 microM progesterone for 72 h. Control progesterone receptor negative MDA-231 cancer cells were unresponsive to 10 microM progesterone. The earliest sign of apoptosis is translocation of phosphatidylserine from the inner to the outer leaflet of the plasma membrane and can be monitored by the calcium-dependent binding of annexin V in conjunction with flow cytometry. After 24 h of exposure to 10 microM progesterone, cytofluorometric analysis of T47-D breast cancer cells indicated 43% were annexin V-positive and had undergone apoptosis and no cells showed signs of cellular necrosis (propidium iodide negative). After 72 h of exposure to 10 microM progesterone, 48% of the cells had undergone apoptosis and 40% were annexin V positive/propidium iodide positive indicating signs of necrosis. Control untreated cancer cells did not undergo apoptosis. Evidence proving apoptosis was also demonstrated by fragmentation of nuclear DNA into multiples of oligonucleosomal fragments. After 24 h of exposure of T47-D cells to either 1 or 10 microM progesterone, we observed a marked down-regulation of protooncogene bcl-2 protein and mRNA levels. mRNA levels of survivin and the metastatic variant CD44 v7-v10 were also downregulated. Progesterone increased p53 mRNA levels. These results demonstrate that progesterone at relative high physiological concentrations, but comparable to those seen in plasma during the third trimester of human pregnancy, exhibited a strong antiproliferative effect on breast cancer cells and induced apoptosis.
 ...
PMID:Bcl-2, survivin and variant CD44 v7-v10 are downregulated and p53 is upregulated in breast cancer cells by progesterone: inhibition of cell growth and induction of apoptosis. 1070 95

Recent advances in therapeutic tumor vaccinations necessitate the identification of broadly expressed, immunogenic tumor antigens that are not prone to immune selection. To this end, the human inhibitor of apoptosis, survivin, is a prime candidate because it is expressed in most human neoplasms but not in normal, differentiated tissues. Here, we demonstrate spontaneous cytotoxic T-cell responses against survivin-derived MHC class I-restricted T-cell epitopes in breast cancer, leukemia, and melanoma patients both in situ as well as ex vivo. Moreover, survivin-reactive T cells isolated by magnetic beads coated with MHC/peptide complexes were cytotoxic against HLA-matched tumors of different tissue types. Being a universal tumor antigen, survivin may serve as a widely applicable target for anticancer immunotherapy.
 ...
PMID:Spontaneous cytotoxic T-cell responses against survivin-derived MHC class I-restricted T-cell epitopes in situ as well as ex vivo in cancer patients. 1150 35

We have constructed a replication-deficient adenovirus encoding a nonphosphorylatable Thr(34)-->Ala mutant of the apoptosis inhibitor survivin (pAd-T34A) to target tumor cell viability in vitro and in vivo. Infection with pAd-T34A caused spontaneous apoptosis in cell lines of breast, cervical, prostate, lung, and colorectal cancer. In contrast, pAd-T34A did not affect cell viability of proliferating normal human cells, including fibroblasts, endothelium, or smooth muscle cells. Infection of tumor cells with pAd-T34A resulted in cytochrome c release from mitochondria, cleavage of approximately 46-kDa upstream caspase-9, processing of caspase-3 to the active subunits of approximately 17 and 19 kDa, and increased caspase-3 catalytic activity. When compared with chemotherapeutic regimens, pAd-T34A was as effective as taxol and considerably more effective than adriamycin in induction of tumor cell apoptosis and enhanced taxol-induced cell death. In three xenograft breast cancer models in immunodeficient mice, pAd-T34A suppressed de novo tumor formation, inhibited by approximately 40% the growth of established tumors, and reduced intraperitoneal tumor dissemination. Tumors injected with pAd-T34A exhibited loss of proliferating cells and massive apoptosis by in situ internucleosomal DNA fragmentation. These data suggest that adenoviral targeting of the survivin pathway may provide a novel approach for selective cancer gene therapy.
 ...
PMID:Cancer gene therapy using a survivin mutant adenovirus. 1180 41

We measured survivin mRNA expression in breast cancers using a fluorogenically detected reverse transcription-polymerase chain reaction, seeking relationships between expression and clinical and histological variables. The mean relative expression of survivin mRNA was 0.347+/-0.466 in breast cancers and 0.017+/-0.023 in noncancerous breast tissue resected with the tumors. A cut-off value for positivity was set at the mean + SD for expression in the noncancerous tissues; positivity for survivin mRNA expression was 90.2% (37 out of 41 cases) in breast cancers and 23% (3 out of 13) in adjacent noncancerous breast tissues. Expression in tumors varied independently of clinicopathological factors except for lymphatic invasion. As measured by our sensitive detection system, survivin mRNA is a useful diagnostic marker for breast cancer.
 ...
PMID:Survivin mRNA expression in patients with breast cancer. 1216 79

The molecular mechanisms underlying the cell cycle growth-inhibitory and apoptotic effects of flavopiridol (FP) were determined in human breast cancer cells. Treatment with FP caused accumulation in the G(1) phase of the cell cycle and induced apoptosis of SKBR-3 and MB-468 cells. This was associated with down-regulation of the levels of cyclins D1 and B1, as well as with inhibition of cyclin-dependent kinase (cdk) 1, cdk2, and cdk4. FP-induced apoptosis was accompanied by a conformational change and mitochondrial localization of Bax. This resulted in the accumulations of cytochrome c, Smac, and Omi/HtrA2 in the cytosol and induced the poly(ADP-ribose) polymerase cleavage activity of caspase-3. Treatment with FP also attenuated the mRNA and protein levels of XIAP, cIAP-2, Mcl-1, Bcl-x(L), and survivin. In MB-468 cells with overexpression of Bcl-2 (468/Bcl-2), FP-induced Bax conformational change and apoptosis were inhibited, whereas the FP-mediated decline in the levels of IAP proteins, Mcl-11 and Bcl-x(L) remained unaltered. The effects of cotreatment with FP and the nontaxane tubulin-polymerizing agent epothilone (Epo) B were also determined in MB-468 cells. Sequential treatment with Epo B followed by FP induced significantly more apoptosis of MB-468 cells than treatment with the reverse sequence of FP followed by Epo B or treatment with either agent alone (P < 0.05). Treatment with Epo B followed by FP induced more Bax conformational change and was associated with a greater decline in the levels of XIAP, cIAP-2, Mcl-1, and Bcl-x(L). However, MB-468/Bcl-2 cells remained relatively resistant to Epo B followed by FP. Taken together, these findings suggest that the superior sequence-dependent anti-breast cancer activity of Epo B followed by FP may be due to FP-induced Bax conformational change and down-regulation of the antiapoptotic IAP, Bcl-x(L), and Mcl-1 proteins, but this treatment may not overcome the resistance to apoptosis of breast cancer cells conferred by overexpression of Bcl-2.
 ...
PMID:Flavopiridol down-regulates antiapoptotic proteins and sensitizes human breast cancer cells to epothilone B-induced apoptosis. 1251 83

Survivin is a member of the inhibitor of apoptosis gene family that is expressed in most human cancers and may facilitate evasion from apoptosis and aberrant mitotic progression. Here, exposure of breast carcinoma MCF-7 or cervical carcinoma HeLa cells to anticancer agents, including Adriamycin, Taxol, or UVB resulted in a 4-5-fold increased survivin expression. Changes in survivin levels after anticancer treatment did not involve modulation of survivin mRNA expression and were independent of de novo gene transcription. Conversely, inhibition of survivin phosphorylation on Thr(34) by the cyclin-dependent kinase inhibitor flavopiridol resulted in loss of survivin expression, and nonphosphorylatable survivin Thr(34)-->Ala exhibited accelerated clearance as compared with wild-type survivin. Sequential ablation of survivin phosphorylation on Thr(34) enhanced tumor cell apoptosis induced by anticancer agents independently of p53 and suppressed tumor growth without toxicity in a breast cancer xenograft model in vivo. These data suggest that Thr(34) phosphorylation critically regulates survivin levels in tumor cells and that sequential ablation of p34(cdc2) kinase activity may remove the survivin viability checkpoint and enhance apoptosis in tumor cells.
 ...
PMID:Suppression of survivin phosphorylation on Thr34 by flavopiridol enhances tumor cell apoptosis. 1251 2

The positivity rates of mRNA expression in breast cancer of the tumor-related genes for c-erbB2, PLU-1 and survivin are unclear. We quantitatively analyzed tissue samples from 39 breast cancers and non-cancerous parts of the same specimens for the above three mRNAs using a TaqMan reverse transcription-polymerase chain reaction (RT-PCR). Using the mean + 2SD of non-cancerous sample as a cut-off value, the positivity rates of the tumors for c-erbB2, PLU-1 and survivin were 20.5%, 7.7% and 69.2%, respectively. Combining consideration of survivin with c-erbB2 and or PLU-1 increased the positivity ratio (survivin plus either of others, 76.9%; survivin plus both, 79.5%). Analysis by histological type indicated that survivin showed the highest positivity in ductal carcinoma and that survivin and PLU-1 showed the same positivity rate (40.0%) in the five carcinomas classified histologically as either solid-tubular or mucinous. Further, all cases that were positive for PLU-1 were negative for survivin. Survivin mRNA expression appeared more useful as a marker for diagnosis of breast cancer than c-erbB2 or PLU-1. However, PLU-1 appeared to vary independently of survivin, enhancing the usefulness of assays considering both in combination.
 ...
PMID:Relevance of c-erbB2, PLU-1 and survivin mRNA expression to diagnostic assessment of breast cancer. 1253 26

Survivin is a new member of the inhibitor of apoptosis protein (IAP) family that is implicated in the control of cell proliferation and the regulation of cell life span. This protein is selectively expressed in most human carcinomas but not in normal adult tissues. To down-regulate a human survivin expression as a strategy for cancer gene therapy, we designed two hammerhead ribozymes (RZ-1, RZ-2) targeting human survivin mRNA. RZ-1 and RZ-2 efficiently cleaved the human survivin mRNA at nucleotide positions +279 and +289, which was identified by in vitro cleavage assay using in vitro transcribed ribozymes and truncated survivin mRNA substrate. To investigate the function of the ribozymes in cells, the sequences of the ribozymes were cloned into replication-deficient adenoviral vector and transferred to breast cancer cell, MCF-7. The infection with adenovirus encoding the ribozymes resulted in a significant reduction of survivin mRNA (74% and 73%, respectively) and protein. As revealed by nuclear condensation/ fragmentation and flow cytometry analysis, inhibition of survivin gene by ribozymes increased apoptosis and sensitivity induced by etoposide or serum starvation. Our results suggest that the designed hammerhead ribozymes against survivin mRNA are good candidates for feasible gene therapy in the treatment of cancer.
 ...
PMID:Ribozyme-mediated cleavage of the human survivin mRNA and inhibition of antiapoptotic function of survivin in MCF-7 cells. 1253 96

Survivin is a member of the inhibitor of apoptosis (IAP) family, and is also involved in the regulation of cell division. Survivin is widely expressed in foetal tissues and in human cancers, but generally not in normal adult tissue. This study examined the expression of surviving protein in a series of 293 cases of invasive primary breast carcinoma. Survivin immunoreactivity was assessed using two different polyclonal antibodies, and evaluated semiquantitatively according to the percentage of cells demonstrating distinct nuclear and/or diffuse cytoplasmic staining. Overall, 60% of tumours were positive for survivin: 31% demonstrated nuclear staining only, 13% cytoplasmic only, and 16% of tumour cells demonstrated both nuclear and cytoplasmic staining. Statistical analysis revealed that survivin expression was independent of patient's age, tumour size, histological grade, nodal status, and oestrogen receptor status. In multivariate analysis, nuclear survivin expression was a significant independent prognostic indicator of favourable outcome both in relapse-free and overall survival (P<0.001 and P=0.01, respectively). In conclusion, our results show that survivin is frequently overexpressed in primary breast cancer. Nuclear expression is most common and is an independent prognostic indicator of good prognosis.
 ...
PMID:Prognostic importance of survivin in breast cancer. 1267 8


1 2 3 4 5 6 7 8 9 10 Next >>