title: Relationship of cell cycle parameters to in vitro and in vivo chemosensitivity for a series of Lewis lung carcinoma lines.
abstract: The sensitivity of three Lewis lung carcinoma sublines, which grow in culture and in vivo, and vary in in vivo drug sensitivity, have been compared using topoisomerase II poisons amsacrine, amsacrine analogue CI-921, doxorubicin and etoposide. D10 (drug concentration for 10% clonogenic survival) values were determined in vitro for low and high density cultures, and ex vivo for cells from subcutaneous tumours. The cytokinetic parameters of these populations were obtained by flow cytometric analysis of bromodeoxyuridine-labelled cells. Regression analysis showed that logarithmic D10 values were significantly correlated (r greater than 0.95) with G1- and S-phase proportions and highly correlated (r = 0.99) with calculated G1 transit times. The slopes of the regression lines were similar for all topoisomerase II poisons tested and it is suggested that this slope reflects the disappearance of topoisomerase II during G1 phase.
authors.affiliation: Cancer Research Laboratory, University of Auckland School of Medicine, New Zealand.
authors.forename: K M
authors.initials: KM
authors.lastname: Holdaway
authors.forename: G J
authors.initials: GJ
authors.lastname: Finlay
authors.forename: B C
authors.initials: BC
authors.lastname: Baguley
mesh_terms: D000970:Antineoplastic Agents / Q000627:therapeutic use*; D002453:Cell Cycle / Q000187:drug effects*; D016923:Cell Death / Q000187:drug effects; D004351:Drug Resistance / Q000502:physiology*; D005434:Flow Cytometry / Q000379:methods; D006801:Humans; D007399:Interphase; D008175:Lung Neoplasms / Q000188:drug therapy*; D014407:Tumor Cells, Cultured / Q000187:drug effects
chemical_list: D000970:Antineoplastic Agents