The role of P53, Bax, Bcl-2 expression and cell apoptosis in the formation and development of acute radiation-induced skin ulcers / 军事医学科学院院刊

ABSTRACT

Objective:To study the expression of P53, Bax, Bcl-2 proteins and the role of cell apoptosis in the formation and development of acute radiation-induced skin ulcers.Methods:A rat model which was locally irradiated with 60 Co γ-rays was used, and the pathological changes were observed for 40 days. Immunohistochemistry and TUNEL assay were performed which enabled the detection of P53, Bax, Bcl-2 and cell apoptosis during the formation and development of radiation skin ulcers.Results: Skin ulcers were found on day 14 after irradiation, and enlarged and deepened gradually during the observation period. P53 was over expressed during days 11 to 40 after irradiation and was localized in vascular endotheliocytes and smooth muscle cells. Bax was moderately positive during days 14 to 21 and weakly positive during days 28 to 35, and was localized in vascular endotheliocytes, some fibroblasts and proliferating keratinocytes. Bcl-2 was weakly positive during days 1 to 11 after irradiation, and was located in keratinocytes, hair follicular cells and some vascular endotheliocytes. Bcl-2 was negative during days 11 to 40.The rate of cell apoptosis, especially of vascular endotheliocytes,wash igher than that in the early process of normal wound healing. Conclusions:After irradiation,the increased expression of the apoptosis-inducing protein P53, Bax and the decreased expression of the apoptosis-inhibiting protein Bcl-2 might be associated with the high rate of apoptotic events, and play important roles in the formation and development of radiation skin ulcers.