- 作者: Hoyun Lee Deqin Sun James M. Larner Fang-Sheng Wu
- 作者服務機構: Northeastern Ontario Regional Cancer Centre, Sudbury, Canada; Department of Biology, Virginia Commonwealth university, richmond, Va., and Department of Radiation Oncology, University of Virginia School of Medicine, Charlottesville, Va., USA
- 中文摘要: --
- 英文摘要: The tumor suppressor p53 is believed to play an essen-tial role in maintaining genome stability. Although it iscurrently unknown how p53 is involved in this importantbiological safeguard, several previous publications indi-cate that p53 can help to maintain genome integritythrough the recombination-mediated DNA repair pro-cess. The integration of linearized plasmid DNA into thehost chromosome utilizes the same repair process, andthe frequency can be measured by clonogenic assays inwhich cells that were stably transfected by plasmid inte-gration can be scored by their colony-forming abilities.To gain insight into whether p53 has a direct role in plas-mid integration into the host chromosome, we deter-mined the frequency of stable transfection with CHOcells expressing either wild-type or mutant p53 in thepresence and absence of irradiation. We found that low-dose irradiation(~50 to 100 cGy) increased stable trans-fection frequencies in CHO cells regardless of their p53status. However, the increase of transfection frequencywas significantly lower in CHO cells expressing wild-typep53. Our data thus suggest that wild-type p53 can sup-press plasmid DNA integration into the host genome.This p53 function may play a direct and significant role inmaintaining genome stability.
- 中文關鍵字: --
- 英文關鍵字: Tumor suppressor P53. Radiation. Plasmid integration. transfection, stable. Recombination. Genetic instability