EXPRESSION OF HEAT-SHOCK PROTEINS HSP70 AND HSP90 IN ENDOMETRIAL CARCINOMAS - CORRELATION WITH CLINICOPATHOLOGY, SEX STEROID-RECEPTOR STATUS, AND P53 PROTEIN EXPRESSION

BACKGROUND, It has been suggested that heat shock proteins HSP70 and H SPSO are involved in the functional modulation of sex steroid receptor s and are expressed in normal endometrium. However, little is known ab out the expression of HSP70 and HSPSO in endometrial carcinomas. METHO DS, The immunohistochemical reactivity of monoclonal antibodies agains t HSP70 and HSPSO was examined in 42 endometrial carcinomas, and the p resence or absence of correlation with the clinicopathologic features, sex steroid receptor status, and p53 protein expression was analyzed. RESULTS, Expression of HSP70 was found in 52% of endometrial carcinom as and was correlated with nonendometrioid histology (P < 0.05), a poo rly differentiated state (P < 0.01), p53 protein expression (P < 0.01) , and absence of sex steroid receptors (P < 0.001) in the tumor. By co ntrast, strong expression of HSP90 was observed in 29% of endometrial carcinomas, and occurred more frequently in well-differentiated carcin omas that were positive for sex steroid receptors. CONCLUSIONS, Both H SP70 and HSP90 are significantly correlated with the histology and the sex steroid receptor status of endometrial carcinomas. Expression of HSP70 may be associated with a loss of sex steroid receptors in either nonendometrioid or poorly differentiated carcinoma of the endometrium , which frequently exhibits p53 protein expression. Conversely, strong expression of HSP90 may indicate high levels of sex steroid receptors in the tumor cells. (C) 1996 American Cancer Society.