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)

Liposarcoma, a malignancy of adipose tissue, is the most common soft tissue sarcoma. Patients whose primary tumor cannot be resected or those who have developed metastasis, have poor prognosis since liposarcomas are highly resistant to chemotherapy. We recently generated a spontaneously immortalized cell line, named LS14, from a patient with metastatic liposarcoma. Our goal was to compare the responsiveness of LS14 and SW872 liposarcoma cells to anti-cancer drugs and explore mechanisms of chemoresistance. Using complementary assays for cell viability and number we found that SW872 cells responded robustly to relatively low concentrations of doxorubicin, cisplatin and vinblastine. This reduction in cell viability was due to apoptosis, as evident by phosphatidylserine exposure and caspase 3 cleavage. In contrast, only a high dose of doxorubicin or combination therapy effectively reduced LS14 cell viability and induced apoptosis. LS14 cells showed a higher expression of Bcl-2 and Bcl-xL, but a lower expression of survivin and Bax, than SW872 cells, suggesting that anti-apoptotic proteins contribute to chemoresistance in LS14 cells. Although LS14 cells did not form colonies in soft agar, they generated large tumors and metastases in SCID mice, establishing their tumorigenicity in vivo. In conclusion, LS14 cells are much more resistant to chemotherapy than SW872 cells, making them an excellent model for exploring the efficacy and mechanism of action of anti-cancer drugs in liposarcomas.
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PMID:LS14 cells: a model for chemoresistance in liposarcoma. 1742 41

Disruption of pathways leading to programmed cell death plays a major role in most malignancies, including multiple myeloma (MM). ABT-737 is a BH3 mimetic small-molecule inhibitor that binds with high affinity to Bcl-2 and Bcl-xL, preventing the sequestration of proapoptotic molecules and shifting the cell survival/apoptosis balance toward apoptosis induction. In this study, we show that ABT-737 is cytotoxic to MM cell lines, including those resistant to conventional therapies, and primary tumor cells. Flow cytometric analysis of intracellular levels of Bcl-2 family proteins demonstrates a clear inversion of the Bax/Bcl-2 ratio leading to induction of apoptosis. Activation of the mitochondrial apoptosis pathway was indicated by mitochondrial membrane depolarization and caspase cleavage. Additionally, several signaling pathways known to be important for MM cell survival are disrupted following treatment with ABT-737. The impact of ABT-737 on survival could not be overcome by the addition of interleukin-6, vascular endothelial growth factor or insulin-like growth factor, suggesting that ABT-737 may be effective in preventing the growth and survival signals provided by the microenvironment. These data indicate that therapies targeting apoptotic pathways may be effective in MM treatment and warrant clinical evaluation of ABT-737 and similar drugs alone or in combination with other agents in the setting of MM.
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PMID:ABT-737, an inhibitor of Bcl-2 family proteins, is a potent inducer of apoptosis in multiple myeloma cells. 1746 Jul

The aim of this study was the analysis of Ki-67, Bcl-2 and Bak expression in primary tumor and axillary lymph node metastases of breast cancer as well as an attempt to assess preoperative chemotherapy influence on the mentioned markers with regard to changes in the morphological appearance of the primary tumor and its metastases. Immunohistochemical examinations of Ki-67, Bcl-2 and Bak expression were conducted on sections collected from 135 patients treated surgically on invasive ductal breast cancer. Sixty-four of these patients were administered preoperative chemotherapy, whilst on 71 patients the surgery was performed without initial chemotherapy. In the group of patients without preoperative chemotherapy positive correlation in Ki-67 and Bcl-2 expression between primary tumors and lymph node metastases (p<0.0001, r=0.707; p<0.0001, r=0.604, respectively) was observed. In the group of patients after chemotherapy positive correlation between primary tumors and lymph node metastases in case of Bcl-2 and Bak proteins (p<0.04, r=0.424; p<0.02, r=0.478, respectively) was observed. It was also found that preoperative chemotherapy has an influence on the expression of proteins connected with proliferation and apoptosis and thus, it can influence neoplastic process biology. It does not have any significant impact on the proapoptotic Bak protein expression either in primary tumor or in lymph node metastases of breast cancer. However, it is related to lower expression of antiapoptotic Bcl-2 protein (p<0.0005) and of Ki-67 proliferation marker (p<0.03) in primary tumors, which indirectly indicates a beneficial influence of preoperative chemotherapy on the primary tumor. Concurrently, the influence of neoadjuvant therapy on lymph node metastases seems to be relatively small, which can limit its effectiveness.
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PMID:The effect of chemotherapy on Ki-67, Bcl-2 and Bak expression in primary tumors and lymph node metastases of breast cancer. 1754 55

Metastases in renal carcinoma are diagnosed at initial diagnosis in 25% examinees. Traditional renal carcinoma has higher metastatic potential, is associated with worse survival of the patients compared to papillary cancer. We studied cytological characteristics of renal carcinoma metastases to the pleura in comparison with histological studies of the primary lesion using immunohistochemical findings. We examined cytologically pleural liquid in renal carcinoma metastases to the pleura in 6 patients (2.3% of carcinomatous pleuricies). High efficacy was shown by a cytocentrifuge CYTOSPIN-4. In 3 cases initial cancer was renal cell carcinoma, pleural exudation developed 2 years later, clear cell carcinoma appeared 6 years later and papillary cancer--10 years later. In the other 3 cases malignant cells were detected in new-onset cases. Renal carcinoma was diagnosed in one case. Cytological preparations were studied with identification of cytological signs typical for classic clear cell, granulocell and papillary renal cancer. Immunohistochemical examination of primary tumor lesion in the kidney discovered high proliferative activity of tumor cells by Ki-67 index to 5.28%. The tumors had solitary Bcl-2 positive cells. Expression of mutant p-53 took place in 0.93%. Her-2/neu hyperexpression was not found in the tumors of the above patients. Such immunohistochemical parameters point to poor prognosis. This is confirmed by renal carcinoma metastases to the pleura.
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PMID:[Pleural metastases of renal carcinoma]. 1757 98

We assessed molecular markers such as BRCA1, K-ras, p53, Bcl-2, Bcl-XL, Survivin and telomerase activity in untreated ovarian cancer tissue samples, ascitic cells and normal ovarian tissues and gathered insights into their correlation with each other and also with apoptotic index. The expression of these proteins was analyzed by Western blotting and immunohistochemistry. Apoptotic index was determined by TUNEL assay and telomerase activity was measured by PCR-ELISA kit. p53, Bcl-2, Bcl-XL, K-ras and Survivin were found to be over expressed in tumors and ascitic cells as compared to normal controls whereas there was no significant difference in expression of BRCA1. A significantly higher telomerase activity and lower apoptotic index in tumors as compared to controls was observed. p53 positively correlated with Bcl-2, Bcl-XL, K-ras and Survivin expression and also clinical stage of the disease. A positive correlation between Survivin and Bcl-2, Bcl-XL was seen. Apoptotic Index, telomerase activity and BRCA1 expression showed no correlation with any of the parameters. Our study confirms the fact that multiple gene interactions govern the pathogenesis of ovarian cancer, and analyzing ascitic cells of ovarian cancer patients may help to delineate molecular profile of the primary tumor.
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PMID:Role of apoptotic regulators in human epithelial ovarian cancer. 1761 99

Metastasis of cancer cells from the primary tumor is associated with poor prognosis and decreased overall survival. One protein implicated in inhibiting metastasis is the tumor metastasis suppressor nonmetastatic protein 23 homologue 1 (NM23-H1). NM23-H1 is a multifunctional protein, which, in addition to limiting metastasis, has DNase and histidine protein kinase activities. We have identified new functions for NM23-H1 in influencing estrogen receptor alpha (ER alpha)-mediated gene expression. Using a battery of molecular and biochemical techniques, we show that NM23-H1 interacts with ER alpha and increases the ER alpha-estrogen response element (ERE) interaction. When NM23-H1 expression is increased in U2 osteosarcoma and MDA-MB-231 breast cancer cells, transcription of a transiently transfected, estrogen-responsive reporter plasmid is decreased. More importantly, when endogenous NM23-H1 expression is knocked down in MCF-7 human breast cancer cells using small interfering RNA, estrogen responsiveness of the progesterone receptor (PR), Bcl-2, cathepsin D, and cyclin D1 genes, but not the pS2 gene, is enhanced. Furthermore, NM23-H1 associates with the region of the PR gene containing the +90 activator protein 1 site, but not with the ERE-containing region of the pS2 gene, indicating that NM23-H1 mediates gene-specific effects by association with endogenous chromatin. Our studies suggest that the capacity of NM23-H1 to limit the expression of estrogen-responsive genes such as cathepsin D and Bcl-2, which are involved in cell migration, apoptosis, and angiogenesis, may help to explain the metastasis-suppressive effects of this protein. The complementary abilities of ER alpha and NM23-H1 together to influence gene expression, cell migration, and apoptosis could be key factors in helping to determine tumor cell fate.
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PMID:Interaction of the tumor metastasis suppressor nonmetastatic protein 23 homologue H1 and estrogen receptor alpha alters estrogen-responsive gene expression. 1797 5

The presence of circulating tumor cells (CTC) is common in prostate cancer patients, however until recently their clinical significance was unknown. The CTC stage is essential for the formation of distant metastases, and their continuing presence after radical prostatectomy has been shown to predict recurrent or latent disease. Despite their mechanistic and prognostic importance, due both to their scarcity and difficulties in their isolation, little is known about the characteristics that enable their production and survival. The aim of this study was to investigate the molecular mechanisms underlying the survival of CTC cells. A novel CTC cell line from the bloodstream of an orthotopic mouse model of castration-resistant prostate cancer was established and compared with the primary tumor using attachment assays, detachment culture, Western blot, flow cytometry and 2D gel electrophoresis. Decreased adhesiveness and expression of adhesion molecules E-cadherin, beta4-integrin and gamma-catenin, together with resistance to detachment and drug-induced apoptosis and upregulation of Bcl-2 were integral to the development of CTC and their survival. Using proteomic studies, we observed that the GRP94 glycoprotein was suppressed in CTC. GRP94 was also shown to be suppressed in a tissue microarray study of 79 prostate cancer patients, indicating its possible role in prostate cancer progression. Overall, this study suggests molecular alterations accounting for the release and survival of CTC, which may be used as drug targets for either anti-metastatic therapy or the suppression of latent disease. We also indicate the novel involvement of GRP94 suppression in prostate cancer metastasis.
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PMID:Decreased adhesiveness, resistance to anoikis and suppression of GRP94 are integral to the survival of circulating tumor cells in prostate cancer. 1834 Apr 25

Chemoprevention represents a promising strategy to reducing the incidence of prostate cancer which afflicts more than 240,000 males annually in the U.S. 2-cyano-3,12-dioxooleana-1,9(11)-dien-28-oic acid (CDDO) and its C-28 methyl ester (CCDO-Me) and C-28 imidazole (CDDO-Im) derivatives are synthetic oleanane triterpenoids that exhibit several-fold more potent antiinflammatory activity than naturally occurring oleanolic acid, but have not been investigated for prevention of the prostate. In order to evaluate the anticancer activity of CDDOs for prostate cancer, we have investigated the effect of synthetic oleanane triterpenoids on molecular targets relevant to the chemoprevention and treatment of prostate cancer in vitro in TRAMPC-1 cells derived from the primary tumor in the prostate of a transgenic adenocarcinoma of the mouse prostate (TRAMP) mouse. Data demonstrate that CDDOs strongly inhibit the proliferation of TRAMPC-1 cells with a potency order of CDDO-Me>CDDO-Im>CDDO. Because CDDO-Me showed the most growth inhibitory activity it was further analyzed for the anticancer activity. CDDO-Me induced apoptosis in TRAMPC-1 cells as shown by the increased binding of annexin V-FITC and cleavage of procaspases 3, -8, and -9. It effectively inhibited the molecular targets such as p-Akt, NF-kappaB, and p-mTOR and downstream effectors of mTOR (p-S6K1, cyclin-D1, and cdk4). Further, CDDO-Me inhibited NF-kappaB-regulated antiapoptotic Bcl-2, Bcl-xL, and XIAP and proangiogenic VEGF. Taken together, these data demonstrate that CDDO-Me is potentially a potent chemopreventive agent that inhibits several molecular targets that are known to play critical roles in the development and progression of prostate cancer.
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PMID:CDDO-Me inhibits proliferation, induces apoptosis, down-regulates Akt, mTOR, NF-kappaB and NF-kappaB-regulated antiapoptotic and proangiogenic proteins in TRAMP prostate cancer cells. 1847 40

Metastatic spread, not primary tumor burden, is the leading cause of cancer death. Glutathione (L-gamma-glutamyl-L-cysteinyl-glycine; GSH) is the most prevalent non-protein thiol in mammalian cells, and in cancer cells is particularly relevant in regulating mutagenic mechanisms, DNA synthesis, growth, and multidrug and radiation resistance. In malignant tumors, as compared with normal tissues, that resistance associates in most cases with higher GSH levels. Interaction of metastatic cells with the vascular endothelium activates local release of proinflammatory cytokines, which act as signals promoting cancer cell adhesion, extravasation, and proliferation. A high% of metastatic cells with high GSH levels survive the nitrosative and oxidative stresses elicited by the endothelium and possibly by macrophages and granulocytes. Gamma-glutamyl transpeptidase overexpression and an interorgan flow of GSH, by increasing cysteine availability for tumor GSH synthesis, promote metastatic growth. The mechanism of NO- and H(2)O(2)-induced tumor cytotoxicity has been examined during murine B16 melanoma (B16M) adhesion to the vascular endothelium. H(2)O(2) was not cytotoxic in the absence of NO. But, NO-induced tumor cytotoxicity was increased by H(2)O(2) due to the formation of potent oxidants, likely (.)OH and ((-))OONO radicals, via a trace metal-dependent process. B16M cells with high GSH content were more resistant to NO and H(2)O(2). Cancer cell survivors showed higher Bcl-2 and GSH levels. Metastatic invaders, after surviving attack by tissue macrophages, may further enhance their resistance.
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PMID:Tumoricidal activity of endothelium-derived NO and the survival of metastatic cells with high GSH and Bcl-2 levels. 1847 63

The efficient treatment of lung carcinomas with chemotherapeutics still poses a challenge for anti-cancer therapy. Since stromal cells of the tumor may alter the responsiveness of tumor cells to chemotherapeutics, we studied the impact of lung fibroblasts (WI-38) on the chemotherapy-induced death of non-small cell lung carcinoma cells (H358). Conditioned medium from WI-38 fibroblasts impaired the H358 cell death induced by paclitaxel but not by cisplatin. Comparable results were observed when culturing H358 cells in conditioned medium from primary tumor fibroblasts or co-culturing H358 cells with fibroblasts. This anti-apoptotic effect induced by paracrine signaling from fibroblasts was associated with less necrosis (membrane leakage, mitochondrial dysfunction) and apoptosis (outer membrane phosphatidylserine exposure, pycnotic nuclei, nuclear translocation of the apoptosis-inducing factor from mitochondria, caspase-9 and -3/-7 activation) in response to paclitaxel but not cisplatin. Additionally, we demonstrated that WI-38 fibroblasts mediate activation of both extracellular signal-regulated kinases (Erk) 1/2 and Akt kinase in H358 cells. Subsequent application of specific inhibitors revealed that the paclitaxel-induced cell death is highly impaired by active Erk1/2 and Akt, whereas the cisplatin-induced cell death is independent of both kinases. Pro-apoptotic Bcl-2 family proteins such as Bim cannot explain the differential impact of fibroblasts on the H358 cell death induced by paclitaxel compared with cisplatin. Our data support the preferential use of the cisplatin-based lung carcinoma therapy, because the cell death-inducing efficiency of cisplatin is not impaired by stromal fibroblasts.
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PMID:Differential impact of fibroblasts on the efficient cell death of lung cancer cells induced by paclitaxel and cisplatin. 1878 12


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