[2002] [BAX GENE][BNP1350]
1: Sheng Wu Hua Xue Yu Sheng Wu Wu Li Xue Bao (Shanghai) 2000;32(4):356-358 Related Articles, Books
Upregulation of bax Gene Expression Promotes Paclitaxel-induced Apoptosis in Esophageal Carcinoma Cells.
Peng WD, Zhang J, Hui HX, Xu YM, Zhu F, Yang AG, Wang CJ.
Department of Biochemistry, Fourth Military Medical University, Xi'an 710033, China. pengwd@263.net
An inducible mammalian expression vector of bax gene was constructed and the control ability of metallothionein II promoter in esophageal carcinoma cell line was systematically identified with luciferase report gene. After the transfection of it into human esophageal carcinoma cell line Eca109, Bax protein expression was analyzed by immunolcytochemical method. Paclitaxel-induced apoptosis was determined by TUNEL assay, DNA ladder assay and flow cytometry. Results showed that 140 &mgr;mol/L ZnSO(4) for 12 h is optimal for induction of bax gene expression. Under these conditions, a clonal transfectant X1097(#), expressing bax gene effectively, was obtained. It was found that, X1097(#) had higher apoptotic rate and was more sensible than Eca109. These results implied that Bax protein may play an important role in paclitaxel-induced apoptosis. Therefore, bax protein may be promising as an helping drug to improve therapeutic effects of paclitaxel.
PMID: 12075422 [PubMed - as supplied by publisher]
ncbi.nlm.nih.gov
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BAX protein expression and clinical outcome in epithelial ovarian cancer [see comments]
Unique Identifier: 98368405
Author: Tai YT; Lee S; Niloff E; Weisman C; Strobel T; Cannistra SA
Source: J Clin Oncol 1998;16(8):2583-90
Address: Department of Adult Oncology, Dana-Farber Cancer Institute, Beth Israel Hospital, Harvard Medical School, Boston, MA 02115, USA.
Abstract:
PURPOSE: Expression of the pro-apoptotic protein BAX sensitizes ovarian cancer cell lines to paclitaxel in vitro by enhancing the pathway of programmed cell death. The present study was performed to determine the relationship between BAX expression and clinical outcome in 45 patients with newly diagnosed ovarian cancer. METHODS: BAX protein expression was analyzed by immunohistochemistry, and its relationship with clinical outcome was determined. Assessment of BAX mRNA transcript levels and mutational analysis of the BAX coding region were also performed. RESULTS: BAX protein was expressed at high levels (defined as > or = 50% of tumor cells positive) in tumor tissue from 60% of newly diagnosed patients. All patients whose tumors expressed high levels of BAX achieved a complete response (CR) to first-line chemotherapy that contained paclitaxel plus a platinum analogue, compared with 57% of patients in the low-BAX group (P = .036). After a median follow-up of 1.9 years, the median disease-free survival (DFS) of patients in the high-BAX group has not been reached, compared with a median DFS of 1.1 years for low-BAX expressors (P = .0061). BAX retained independent prognostic significance in multivariate analysis when corrected for stage and histology. BAX mRNA transcripts were easily detected in samples with low BAX protein expression, and no BAX mutations were identified. CONCLUSION: The correlation between high BAX levels and improved clinical outcome suggests that an intact apoptotic pathway is an important determinant of chemoresponsiveness in ovarian cancer patients who receive paclitaxel.
slip.net
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Oncogene (zurück zum Seitenanfang)
Oncogene 2001 Aug 30;20(38):5249-57
The Chk1-Cdc25C regulation is involved in sensitizing A253 cells to a novel topoisomerase I inhibitor BNP1350 by bax gene transfer.
Yin M, Hapke G, Guo B, Azrak RG, Frank C, Rustum YM.
Department of Pharmacology and Therapeutics, Grace Cancer Drug Center, Roswell Park Cancer Institute, Elm and Carlton Streets, Buffalo, New York, NY 14263, USA.
Promotion of apoptosis may potentiate the sensitivity of tumor cells to chemotherapeutic agents, thus improving the efficacy of cancer treatment. The transfection of the proapoptotic bax gene, which results in the overexpression of bax protein, augments the growth inhibition of A253 cells by BNP1350. Increased drug response was associated with the induction of DNA fragmentation in the size of 30-200 Kb, generating a cleaved fragment of 18 kDa from full-length 21 kDa bax and the cleavage of PARP. A253/vec cells treated with 0.07 microM(IC50) of BNP1350 accumulated in G2 phase at 24 h after drug removal. In contrast, A253/Bax cells treated with an equimolar concentration of BNP1350 primarily displayed a G1 phase accumulation with a concurrent decrease in G2 phase. Certain cell cycle regulatory protein expression and activities were altered following drug exposure in both cell lines under similar conditions. Cdk2- and cdc2-associated H1 kinase activities were markedly increased in the A253/Bax cell line with marginal increased activity in the A253/vec cell line. A chk1 activity assay was performed with GST-cdc25C (200-256) or GST-cdc25C(S216A) (200-256) fusion proteins as the substrate. Increased chk1 activity was observed in the A253/vec cell line, with little change in the A253/Bax cell line, when exposed to equimolar concentrations of BNP1350 (0.07 microM). A Western blot of immunoprecipitated chk1 indicated that increased chk1 phosphorylation following DNA damage induced by BNP1350 was accompanied by the observed G2 accumulation in the A253/vec cell line, while only a slight increase in chk1 phosphorylation was seen in the A253/Bax cell line. A decreased expression of cdc25C was observed in the BNP1350-treated A253/Bax cells, but not in the A253/vec cell line. Following exposure to BNP1350, increased binding of 14-3-3 proteins to chk1 occurred in both cell lines, with more being observed in the A253/vec cell line. The data have shown that inhibition of the chk1 pathway accompanied by the abrogation of G2 arrest is involved in sensitizing A253 cells to BNP1350 by bax gene transfer. These findings suggest that bax gene transfer sensitizes A253 cells to BNP1350 through apoptosis promoting and G2/M DNA damage checkpoint regulatory pathways
uni-essen.de
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BNP1350
Publish Date: 11/12/1999
Generic Name: karenitecin
Metabolism: Drug is highly protein-bound in the plasma, and has a plasma half-life of 16 hours. Primary route of excretion is probably hepatobiliary, as less than 1% of the drug is excreted by the urinary route.
Dosage Range: Per investigational protocol. Currently, two IV schedules of administration are being studied in adults:
1.0 mg/m2/day IV × 5 consecutive days q3 weeks.
Weekly IV administration.
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