The interaction of taxol and vinblastine with radiation induction of p53 and p21 WAF1/CIP1.

The combination of the microtubule active drug taxol with radiation has shown promise for use in combined modality therapy. Recent studies have demonstrated that radiation and a wide range of chemotherapy agents, including microtubule active drugs, induce p53. In certain circumstances, the induction of p53 has been shown to be an important parameter in the response of a tumour to cytotoxic treatment. We examined the induction of p53 and its downstream target, p21WAF1/CIP1, by the microtubule active agents taxol and vinblastine with radiation. An increase in induction of both p53 and p21 WAF1/CIP1 was demonstrated when radiation was added to either taxol or vinblastine treatment. These results, in conjunction with data on taxol and vinblastine induction of p21WAF1/CIP1, suggest a rationale for the combination therapy.