© 1989 Oxford University Press
research-article |
UVC-induced expression of a tumor-associated antigen in human cell hybrids (HeLa x skin fibroblasts): repair of potentially lethal and potentially transforming damage
Division of Radiation Oncology, Department of Radiological Sciences, University of California Irvine, CA 92717, USA
The UVC-induced expression of a cell surface protein which correlates with the induction of tumorigenicity has been observed in human cell hybrids (HeLa x skin fibroblasts). A dose-response curve for the induction of this marker of neoplastic transformation has been obtained. Studies of the repair of potentially lethal and potentially transforming damage indicate a slow repair process which results in enhanced survival and decreased neoplastic transformation over the period 624 h post-treatment. The kinetics of this repair process are consistent with previously published work on the kinetics of removal of thymine dimers from UVC-irradiated human skin fibroblasts. During the first few hours post-irradiation (06 h) there are fluctuations in transformation frequency while survival remains essentially constant. It is during this period that 64 photoproducts are removed from UV-irradiated DNA. It is possible that repair of these lesions may lead to an increase in transformation frequency and have no impact in terms of survival.