BACKGROUND: To investigate the mechanisms of cisplatin (CDDP)-resistance in neuroblastoma(NB), we established a CDDP-resistant human NB cell line, BM1R2. MATERIALS AND METHODS: We characterized BM1R2 in terms of the susceptibilities to other anticancer agents, MDR1 and MRP expression, MYCN amplification, intracellular gultathione-S-transferase(GST-pi), metallothionein(MT) and gultathione(GSH) levels, and immunocytochemical and cytogenetic features. RESULTS: When compared to parent BM1 line, BM1R2 exhibited a 17.0-fold resistance to CDDP and cross-resistance to other agents. MRP expression was only observed in BM1R2, whereas MDR1 was expressed in both lines. Notably higher intracellular GST-pi and MT levels were observed in BM1R2 cells. MYCN amplifications were 50 and 6 copies in BM1 and BM1R2, respectively, and additional aberrations were observed in chromosome 1 and 2 in BM1R2. CONCLUSION: It was suggested that GST-pi and MT could exert crucial roles on CDDP-resistance in our system. BM1R2 is of great interest for investigating the mechanisms of CDDP-resistance in NB.
BACKGROUND: To investigate the mechanisms of cisplatin (CDDP)-resistance in neuroblastoma(NB), we established a CDDP-resistant human NB cell line, BM1R2. MATERIALS AND METHODS: We characterized BM1R2 in terms of the susceptibilities to other anticancer agents, MDR1 and MRP expression, MYCN amplification, intracellular gultathione-S-transferase(GST-pi), metallothionein(MT) and gultathione(GSH) levels, and immunocytochemical and cytogenetic features. RESULTS: When compared to parent BM1 line, BM1R2 exhibited a 17.0-fold resistance to CDDP and cross-resistance to other agents. MRP expression was only observed in BM1R2, whereas MDR1 was expressed in both lines. Notably higher intracellular GST-pi and MT levels were observed in BM1R2 cells. MYCN amplifications were 50 and 6 copies in BM1 and BM1R2, respectively, and additional aberrations were observed in chromosome 1 and 2 in BM1R2. CONCLUSION: It was suggested that GST-pi and MT could exert crucial roles on CDDP-resistance in our system. BM1R2 is of great interest for investigating the mechanisms of CDDP-resistance in NB.