Characterization of a BMS-181174-resistant human bladder cancer cell line

• Published in: British journal of cancer Vol. 76; no. 4; pp. 461 - 466
• Main Authors: XIA, H, BLEICHER, R. J, HU, X, SRIVASTAVA, S. K, GUPTA, V, ZAREN, H. A, SINGH, S. V
• Format: Journal Article
• Language: English
• Published: Basingstoke Nature Publishing Group 01.01.1997
• Subjects: Antineoplastic agents; Antineoplastic Agents, Alkylating - pharmacology; Biological and medical sciences; Cell Survival - drug effects; Chemotherapy; Drug Resistance; Humans; Medical sciences; Mitomycin - pharmacology; Mitomycins; Pharmacology. Drug treatments; Tumor Cells, Cultured; Urinary Bladder Neoplasms - drug therapy; Urinary Bladder Neoplasms - pathology; Antineoplastic agent; Cell culture; Urinary system disease; Mitomycin; Urinary tract disease; Malignant tumor; Experimental study; Resistance; Antibiotic; Urinary bladder; Analog; Bladder disease; Mechanism of action
• ISSN: 0007-0920; 1532-1827
• DOI: 10.1038/bjc.1997.410

This study was undertaken to elucidate the mechanism of cellular resistance to BMS-181174, a novel analogue of mitomycin C (MMC), in a human bladder cancer cell line. The BMS-181174-resistant variant (J82/BMS) was established by repeated continuous exposures of parental cells (J82) to increasing concentrations of BMS-181174 (9-40 nM) over a period of about 17 months. A 2.6-fold higher concentration of BMS-181174 was required to kill 50% of J82/BMS cell line compared with J82. The J82/BMS cell line exhibited collateral sensitivity to 5-fluorouracil (5-FU), but was significantly more cross-resistant to MMC, melphalan, taxol, doxorubicin and VP-16. NADPH cytochrome P450 reductase and DT-diaphorase activities, which have been implicated in bioreductive activation of MMC, were significantly lower in the J82/BMS cell line than in J82. The cytotoxicity of BMS-181174, however, was not affected in either cell line by pretreatment with dicoumarol, which is an inhibitor of DT-diaphorase activity. These results argue against a role of DT-diaphorase in cellular bioactivation of BMS-181174, a conclusion consistent with that of Rockwell et al (Biochem Pharmacol, 50: 1239-1243, 1995). BMS-181174-induced DNA interstrand cross-link (DNA-ISC) frequency was markedly lower in J82/BMS cell line than in J82 at every drug concentration tested. The results of the present study suggest that cellular resistance to BMS-181174 in J82/BMS cell line may be due to reduced DNA-ISC formation. However, the mechanism of relatively lower BMS-181174 induced DNA-ISC formation in J82/BMS cell line than in parental cells remains to be clarified.