TY - JOUR
T1 - Characterization of a BMS-181174-resistant human bladder cancer cell line
AU - Xia, H.
AU - Bleicher, R. J.
AU - Hu, X.
AU - Srivastava, S. K.
AU - Gupta, V.
AU - Zaren, H. A.
AU - Singh, S. V.
PY - 1997
Y1 - 1997
N2 - 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 The BMS-181174-resistant variant (J82/BMS) was established by repealed continuous exposures of parental cells (J82) to increasing concentrations of BMS-181174 (9-40 nM) over a period of about 17 months.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. 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.
AB - 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 The BMS-181174-resistant variant (J82/BMS) was established by repealed continuous exposures of parental cells (J82) to increasing concentrations of BMS-181174 (9-40 nM) over a period of about 17 months.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. 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.
KW - Antineoplastic Agents, Alkylating/pharmacology
KW - Cell Survival/drug effects
KW - Drug Resistance
KW - Humans
KW - Mitomycin/pharmacology
KW - Mitomycins
KW - Tumor Cells, Cultured
KW - Urinary Bladder Neoplasms/drug therapy
UR - http://www.scopus.com/inward/record.url?scp=0030858759&partnerID=8YFLogxK
U2 - 10.1038/bjc.1997.410
DO - 10.1038/bjc.1997.410
M3 - Article
C2 - 9275022
AN - SCOPUS:0030858759
SN - 0007-0920
VL - 76
SP - 461
EP - 466
JO - British Journal of Cancer
JF - British Journal of Cancer
IS - 4
ER -
