title: Tumor resistance to therapy: a genetic or kinetic problem?
abstract: Chinese hamster V79 spheroids exposed to cisplatin for 2 hr daily for 3 weeks responded very similarly to tumors undergoing chemotherapy. Initially, the number of viable cells per spheroid decreased in a dose-dependent fashion but, after several treatments, the apparent effectiveness of the cisplatin decreased. At low doses, spheroid regrowth eventually occurred despite continued therapy. A detailed examination of the cellular basis for this response showed that the so-called acquired resistance was not due to a change in cellular responsiveness to cisplatin but, rather, was the result of a marked increase in the cellular growth fraction in the treated spheroids.
authors.affiliation: Medical Biophysics Unit, B.C. Cancer Research Centre, Vancouver, Canada.
authors.forename: R E
authors.initials: RE
authors.lastname: Durand
authors.forename: S L
authors.initials: SL
authors.lastname: Vanderbyl
mesh_terms: D000818:Animals; D002455:Cell Division / Q000187:drug effects*; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects*; D002945:Cisplatin / Q000494:pharmacology*; D006224:Cricetinae; D003412:Cricetulus; D004247:DNA / Q000302:isolation & purification; D004351:Drug Resistance / Q000235:genetics; D007700:Kinetics; D008168:Lung; D008954:Models, Biological
chemical_list: D004247:DNA; D002945:Cisplatin