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)

Cisplatin is one of the most potent anticancer agents, displaying significant clinical activity against a variety of solid tumors. For more than two decades, the most effective systemic chemotherapy for non-small cell lung cancer (NSCLC), the leading cause of cancer morbidity and mortality among men and women in the western world, was cisplatin-based combination treatment. Unfortunately, the outcome of cisplatin therapy on NSCLC seems to have reached a plateau. Therefore, the biological mechanisms of cisplatin action need to be understood in order to overcome the treatment plateau on NSCLC. Moreover, the development of resistance is a hurdle in the use of this drug. The molecular mechanisms that underlie this chemoresistance are largely unknown. Possible mechanisms of acquired resistance to cisplatin include reduced intracellular accumulation of cisplatin, enhanced drug inactivation by metallothionine and glutathione, increased repair activity of DNA damage, and altered expression of oncogenes and regulatory proteins. In addition, it is generally accepted that cytotoxicity of cisplatin is mediated through induction of apoptosis and arrest of cell cycle resulting from its interaction with DNA, such as the formation of cisplatin-DNA adducts, which activates multiple signaling pathways, including those involving p53, Bcl-2 family, caspases, cyclins, CDKs, pRb, PKC, MAPK and PI3K/Akt. Increased expression of anti-apoptotic genes and mutations in the intrinsic apoptotic pathway may contribute to the inability of cells to detect DNA damage or to induce apoptosis. Towards an understanding of the molecular basis of the cellular response to cisplatin-based chemotherapy in NSCLC, in this review we provide some insights into the pathways involved in cisplatin damage from entering the cells to execution of apoptosis or survival of NSCLC cells. We believe that as more and more molecular mechanisms of response to cisplatin-based therapy are unraveled, this knowledge should provide a basis for further studies to improve our understanding of molecular events associated with lung NSCLC as well as to devise novel and effective therapeutic approaches to overcome the treatment plateau or reverse drug resistance in this disease.
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PMID:Molecular basis of cellular response to cisplatin chemotherapy in non-small cell lung cancer (Review). 1549 78

Taxanes (docetaxel and paclitaxel) as well as cisplatin (CDDP) are key chemotherapeutic agents in the treatment of non-small cell lung cancer (NSCLC). Although some indicators of taxane resistance, such as beta-tubulin mutations, P-glycoprotein (P-gp) and Bcl-2, have been reported in malignant cells, the mechanisms of taxane resistance in NSCLCs have yet to be fully elucidated. We evaluated in vitro chemosensitivity to docetaxel (DOC) and CDDP in 87 surgically-resected specimens of NSCLC by collagen gel-droplet embedded culture drug sensitivity test (CD-DST). Bcl-2 and P-gp expression in these specimens were also investigated by immunohistochemistry. We examined the association between Bcl-2 and P-gp expression and in vitro chemosensitivity to DOC and CDDP. Out of the 87 NSCLCs that were examined, Bcl-2 and P-gp were expressed in 32 (36.8%) and 28 (32.2%) of the tumors, respectively. Positive Bcl-2 expression was significantly associated with enhanced DOC sensitivity in NSCLCs (p=0.007) while no apparent association was observed between DOC sensitivity and P-gp expression. Interestingly, although DOC, but not CDDP has been reported to be a substrate of P-gp, P-gp expression was significantly inversely correlated with CDDP sensitivity in pulmonary adenocarcinomas (p=0.03). Positive Bcl-2 expression may be a promising indicator in determining in vitro taxane sensitivity in NSCLCs. On the other hand, positive P-gp expression may be an indicator of enhanced in vitro resistance to CDDP in pulmonary adenocarcinomas.
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PMID:Bcl-2 overexpression enhances in vitro sensitivity against docetaxel in non-small cell lung cancer. 1564 8

Non-small cell lung cancer (NSCLC) often shows intrinsic multidrug resistance, which is one of the most serious problems in cisplatin-based adjuvant chemotherapy. Anticancer drugs exert at least part of their cytotoxic effect by triggering apoptosis. In order to understand the molecular alterations leading to heterogeneous cisplatin sensitivity and apoptosis inducibility in NSCLC cells, we analyzed various apoptotic pathways, including the activation of caspase-8, -9 and -3, the release of cytochrome c from mitochondria and the expression levels of pro- and anti-apoptotic proteins such as Bax, Bad, Bcl-2, Bcl-xL, Fas and p53 using heterogeneously apoptosis-sensitive cells (Ma-10, Ma-31 and Ma-46). Cisplatin treatment induced the activation of caspase-8, -9 and -3 and the release of cytochrome c in apoptosis-sensitive Ma-46. The expression of Bcl-xL was the highest and p53 was not expressed in apoptosis-resistant Ma-31, and Fas was not expressed in Ma-46. These expression levels were not correlated with the apoptosis inducibility of the three cell lines. These results suggest that blockage of the apoptotic signal from mitochondria is responsible for apoptosis resistance in NSCLC cell lines. Our findings also indicate that anti-apoptotic Bcl-xL and pro-apoptotic p53 are necessary but not sufficient for resistance to cisplatin-induced apoptosis in NSCLC cells.
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PMID:Defects in apoptotic signal transduction in cisplatin-resistant non-small cell lung cancer cells. 1587 Sep 47

Improvements in conventional cytotoxic treatment have probably reached a plateau for the treatment of lung cancer; therefore, new treatment strategies that are based on a better understanding of tumour biology are required. Some progress has been made for non-small cell lung cancer, in which erlotinib (Tarceva, OSI-774; Genentech), an epidermal growth factor receptor antagonist, has demonstrated a significant clinical benefit in a Phase III randomised trial, and has been licensed for second- or third-line treatment. Other therapies under investigation include angiogenesis inhibitors, COX-2 inhibitors, retinoids, farnesyl transferase inhibitors, Bcl-2 inhibitors and c-Kit antagonists. In this article the recent and ongoing Phase II and III trials of these therapies in lung cancer are summarised, and the prospects for their further clinical development are discussed.
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PMID:Perspectives on novel therapies for bronchial carcinoma. 1595 69

Bcl-2 is involved in the progression of human malignancies, but the precise role and mechanism of Bcl-2 for tumor invasion and metastasis remains unclear. In this study, we have investigated the role and mechanism of Bcl-2 on tumor cell invasion and metastasis by using Bcl-2 overexpressing non-small cell lung cancer cells. Matrix metalloproteinases (MMPs) are important proteins involved in the processes of tumor invasion and metastasis. In vitro Matrigel invasion assays showed that Bcl-2 overexpression increased tumor cell invasion by 15-fold. Moreover, Bcl-2 overexpression enhanced in vivo lung metastasis by 4-fold. Consistent with its effect on invasion and metastasis, Bcl-2 overexpression induced not only MMP-2 mRNA and its protein expression, but this also activated the pro-MMP-2 protein to its active form. To explore the induction mechanism of MMP-2 by Bcl-2, we investigated the effects of Bcl-2 overexpression on MMP-2 transcriptional regulation. Nuclear run-on assays showed a 6-fold increase in the transcription rate of MMP-2 mRNA in the Bcl-2 transfectants (H157/Bcl-2) compared with that of the H157/vector control cells (H157/C). Overexpression of Bcl-2 induced the nuclear transcription factor activator protein 1 family, including the c-Jun, JunD, c-Fos, FosB, and Fra-1 proteins. Reporter assays combined with deletion mutagenesis analysis and gel shift assays showed the involvement of activator protein 1 in the activation of MMP-2 promoter activity by Bcl-2. Taken together, we have shown that Bcl-2 promotes tumor invasion and lung metastasis by inducing MMP-2 gene expression through the combined action of transcriptional and posttranslational mechanisms.
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PMID:Bcl-2 promotes invasion and lung metastasis by inducing matrix metalloproteinase-2. 1599 27

Although histone deacetylase (HDAC) inhibitors are emerging as a promising new treatment strategy in malignancy, how they exert their effect on human non-small cell lung cancer cells is as yet unclear. This study was undertaken to investigate the underlying mechanism of an HDAC inhibitor, Trichostatin A (TSA), -induced apoptosis in a human lung carcinoma cell line A549. The effects of this compound were also tested on cyclooxygenase (COX) activity. Treatment of A549 cells to TSA resulted in the inhibition of viability and the induction of apoptosis in a concentration-dependent manner, which could be proved by trypan blue counts, DAPI staining, agarose gel electrophoresis and flow cytometry analysis. Apoptosis of A549 cells by TSA was associated with a down-regulation of anti-apoptotic Bcl-2 protein and an up-regulation of pro-apoptotic Bax protein. TSA treatment induced the proteolytic activation of caspase-3 and caspase-9, and a concomitant degradation of poly(ADP-ribose)-polymerase protein. Furthermore, TSA decreased the levels of COX-2 mRNA and protein expression without significant changes in the levels of COX-1, which was correlated with an inhibition in prostaglandin E2 synthesis. Taken together, these findings provide important new insights into the possible molecular mechanisms of the anti-cancer activity of TSA.
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PMID:Induction of apoptosis by trichostatin A, a histone deacetylase inhibitor, is associated with inhibition of cyclooxygenase-2 activity in human non-small cell lung cancer cells. 1601 Apr 30

The aim of our study was to estimate the expression of the Bcl-xL gene, a member of Bcl-2 family, in NSCLC patients. A total of 60 consecutive patients diagnosed with NSCLC that underwent chemotherapy prior to surgery were reviewed. Bcl-xL expression was assessed on paraffin sections by in situ hybridization (ISH) and immunohistochemistry (IMH). We observed the presence of mRNA of Bcl-xL gene and its protein product overexpression in most patients (60 and 81.7%, respectively). In material examined no significant correlation was observed between the pattern of Bcl-xL or protein expression and any clinicopathological factors evaluated. The expression of Bcl-xL protein was low (less than 10% positive cells) in 11 patients (median survival time 29 months) as compared to 49 patients with overexpression (median survival time 21.0 months). The difference was not of statistic significance (p=0.27). In examined group the Bcl-xL mRNA was found in 36 patients, while it was absent in 24 cases. Median survival time was 14.5 and 86.5 months, respectively (p=0.001). In addition, 19.4% of 5-year survivals were achieved in patients with overexpression and 54.2% in patients with no mRNA present (p=0.002). The percentage of 5-year survival in patients with protein expression assessed by IMH was 30.6% (p=0.31). The estimation of Bcl-xL expression on mRNA and protein level was compared by the means of sign test and the significant difference was found (p=0.009). The inconsistency was related to 35% of cases. In comparison with IMH, ISH technique appeared to be more specific and accurate in assessment of 5-year survival (25 and 65%; 65 and 70%, respectively). The results of our study indicate that Bcl-xL mRNA overexpression may suggest poor prognosis in NSCLC.
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PMID:Estimation of prognostic value of Bcl-xL gene expression in non-small cell lung cancer. 1629 99

Beauvericin (BEA), a cyclic hexadepsipeptide from Codyceps cicadae, possesses anti-convulsion, anti-arrhythmia, sedation, and anti-tumor activities. It has been reported that BEA induces apoptosis in several cancer cell lines. However, the molecular mechanism underlying the BEA-induced apoptotic process is not yet clearly understood. In the present study, the intracellular signaling pathways of BEA-induced apoptosis in human non-small cell lung cancer (NSCLC) A549 cells were investigated using morphological analysis and terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) technique. In this study, BEA-induced apoptosis in human NSCLC A549 cells demonstrated a BEA concentration- and treatment time-dependent manner. This BEA-induced apoptosis in human NSCLC A549 cells was also accompanied by the up-regulation of Bax, Bak, and p-Bad and down-regulation of p-Bcl-2, but no effect on the levels of Bcl-X(L) or Bad proteins. Moreover, the BEA treatment resulted in a significant reduction of mitochondrial membrane potential, increase in the release of mitochondrial cytochrome c (cyt c), and activation of caspase 3. Furthermore, treatment with caspase 3 inhibitor (z-DEVD-fmk) was capable to prevent the BEA-induced caspase 3 activity and cell death. These results clearly demonstrate that the induction of apoptosis by BEA involves multiple cellular/molecular pathways and strongly suggest that pro- and anti-apoptotic Bcl-2 family proteins, mitochondrial membrane potential, mitochondrial cyt c, and caspase 3, they all participate in BEA-induced apoptotic process in human NSCLC A549 cells.
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PMID:Involvement of Bcl-2 family, cytochrome c and caspase 3 in induction of apoptosis by beauvericin in human non-small cell lung cancer cells. 1629 11

One of the most valuable objectives for oncologists is the ability to predict patient response to chemotherapy before drugs are administered in order to maximise the therapeutic benefit of treatment whilst limiting the toxicity. This is particularly relevant in non-small cell lung cancer as the initial treatment decision is important due to the inherent drug resistance of many tumours and short survival times of patients. We established a homogeneous series of pre-treatment archival biopsy samples from patients receiving first-line single-agent vinorelbine for non-small cell lung cancer. Cases were selected following strict inclusion criteria and patient response was assessed using the Response Evaluation Criteria in Solid Tumours guideline. The expression of 7 proteins was investigated and correlated with response data. Chi-square analysis revealed no association between expression of Bcl-2, Bcl-XL, Bad, Bak, Bid or p53 proteins and response to vinorelbine therapy. There was a trend for Hsp27-positive tumours to show progression but this did not reach significance (p=0.068). The results suggest that Hsp27 expression may be useful as a predictor of response to single-agent vinorelbine chemotherapy in non-small cell lung cancer patients but a larger study is required to confirm this.
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PMID:Hsp27 may allow prediction of the response to single-agent vinorelbine chemotherapy in non-small cell lung cancer. 1632 69

The aim of this study was to determine the expression of Bcl-2 gene and prognostic importance of Bcl-2 expression in paraffin embedded blocks of patients diagnosed with non-small cell lung cancer (NSCLC). This study included the retrospective analysis of overall 46 patients diagnosed with NSCLC in our clinic between 1996 and 1999. In 16 (34.8%) patients, the diagnosis was made on biopsy of bronchial mucosa and in 30 (65.2%) patients, on materials obtained by surgical resection (lobectomy and pneumonectomy). We reviewed the sections 4-6 microns in size and stained with Hemotoxylin-Eosine (HE) obtained from paraffin embedded blocks and fixed by 10% formalin. These sections are transferred on to slides covered with poly-L-lysine, then de-paraffinization was made. In all cases, immunohistochemical staining with Bcl-2 antibodies was performed. Positive staining was observed in 9 (19.6%) patients, but not in 37 (80.4%) patients. Out of 32 cases with squamous cell tumor, 8 (25%) were observed to have positive staining in their sections, but 24 (75%) were not so. No staining was observed in 11 cases whose cell type was adenoma and two cases whose cell type was adenosquamos (100%). Staining was present in the section of one case with large cell (100%). Median survival time was 36.6 months in cases in which staining was observed and 6.10 months in cases in which staining was not observed, with a significant difference (p< 0.05). In conclusion, the rate of survival was higher in cases in which staining was present.
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PMID:Distribution of Bcl-2 gene expression and its prognostic value in non-small cell lung cancer. 1645 30


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