RADIATION-INDUCED G2 M BLOCK AND APOPTOSIS IN 2 HUMAN SARCOMA CELL-LINES WITH DIFFERENT P53 GENE STATUS/

We investigated a wild-type (wt) p53 rhabdomyosarcoma (A-204) and a mu tated (mt p53) undifferentiated sarcoma cell line (US8-93) for their r esponse to X-rays. The observation period was 0 to 96 h after irradiat ion. Both cell lines showed a strikingly delayed G2/M arrest and an in duction of apoptosis after irradiation. Compared with the cell line A- 204 (wt p53), the cell line US8-93 (mt p53) revealed a stronger G2/M a rrest. In agreement with this, in terms of viability as well as the ra te of apoptosis, A-204 (wt p53) showed a stronger response to irradiat ion than US8-93 (mt p53). We suggest that the different p53 gene statu s might be the cause for a different response to irradiation.