Expression of resistance to etoposide and vincristine in vitro and in vivo after X-irradiation of ovarian tumor cells.
Two human ovarian carcinoma cell lines (JA-T/P and SK-OV-3/P) were exposed to 10 fractions of 5 Gy X-irradiation in vitro. Surviving populations generated sublines designated DXR-10 which expressed significant resistance to etoposide (VP-16) and vincristine (VCR), but not to adriamycin (ADR) or acute X-irradiation, as judged by clonogenic assays. JA-T/P and JA-T/DXR-10 tumor cells were xenografted into nude mice and treated with a single dose of VCR (1.8 mg/kg), VP-16 (24.5 mg/kg) or ADR (10.0 mg/kg) and 48 h later the surviving clonogenic cells in each tumor were quantitated. Significantly fewer colonies grew from the JA-T/P xenografts treated with either VCR or VP-16, as opposed to the JA-T/DXR-10 tumors, whilst comparable colony numbers were recorded after ADR treatment. These data suggest that the resistant phenotype following exposure to fractionated X-irradiation in vitro is also expressed in vivo.
Dempke
W C
WC
Medical Oncology Clinic, University of Aachen, Germany.
Whelan
R D
RD
Hill
B T
BT
D000818:Animals; D004351:Drug Resistance / Q000235:genetics; D004354:Drug Screening Assays, Antitumor; D005047:Etoposide / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D051379:Mice; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D010051:Ovarian Neoplasms / Q000188:drug therapy* / Q000473:pathology / Q000532:radiotherapy; D010641:Phenotype; D014183:Transplantation, Heterologous; D014407:Tumor Cells, Cultured; D014750:Vincristine / Q000627:therapeutic use*
D014750:Vincristine; D005047:Etoposide