Relationships between clonogenic cell survival, DNA damage and chromosomalradiosensitivity in nine human cervix carcinoma cell lines

Purpose: To compare clonogenic cell survival, DNA damage and chromosomal ra diosensitivity in nine cervix carcinoma cell lines. Materials and methods: Initial and residual (after 24 h repair) radiation-i nduced DNA damage was evaluated using pulsed field gel electrophoresis. Chr omosome damage was measured by micronucleus (MN) induction in cytochalasin- B-induced binucleate cells. Results: Significant differences between the cell lines were obtained in th e induced levels of initial damage, residual damage and MN. Values for SF2 for the nine cell lines ranged from 0.36 to 0.92. No correlation was found between clonogenic measurements of radiosensitivity and initial DNA damage dose-response slopes. However, borderline significant correlations were see n between clonogenic radiosensitivity data and the levels of residual DNA d amage. There was no correlation between clonogenic radiosensitivity and the levels of radiation-induced MN. Cell lines with high levels of initial dam age had high yields of MN induced by radiation and the correlation seen was significant. Conclusions: The poor correlation between the different endpoints precludes their use in a clinical setting on primary tumour samples in vitro. It may be that tumour cell lines in vitro are a poor model for rumours in vivo. S tudies aimed at assessing assays for measuring tumour radiosensitivity ther efore should employ clinical samples. In vitro cell line work should concen trate on unravelling the complex mechanisms involved in determining a radio sensitive or radioresistant phenotype.