Abnormal location of p16 protein and overexpression of p53 protein in human radiation-induced skin cancer.

To evaluate the role of p16 multiple tumor suppressor (MTS1) and p53 protein in human radiation-induced skin cancer, we examined the expression of p16 and p53 in eight cases using immunohistochemistry. An abnormal location of p16 expression in the cytoplasm was found in seven of eight cases, but the expression of p53 in nuclei was noted in only three of eight cases. These findings suggest that the inactivation of p16 might be related to its binding with another unknown oncoprotein in the cytoplasm and thus lead to carcinogenesis.