HSP70 AND HSC70 ARE PREFERENTIALLY EXPRESSED IN DIFFERENTIATED EPITHELIAL-CELLS IN NORMAL HUMAN ENDOMETRIUM AND ECTOCERVIX

Two highly related 70K heat shock proteins, encoded by the hsc70 and h sp70 genes, are located in the nucleocytoplasmic compartment of mammal ian cells. In contrast to rodent cell lines, which express Hsp70 only when stressed, many human cell lines constitutively express Hsp70. The degree to which this reflects constitutive expression of Hsp70 in nor mal human tissues has not been extensively examined. In this study, we show by immunoblotting that human Hsp70 is constitutively expressed i n the ovary, cervix, and endometrium and, by immunohistochemical analy sis using Hsp70- and Hsc70-specific antibodies, that Hsp70 and Hsc70 a re expressed in distinctive and predominantly overlapping patterns in the cervix and endometrium. In these two tissues, the highest levels o f both proteins are seen in differentiated, non-proliferating epitheli al cells, which is surprising in light of previous studies suggesting growth stimulation of hsp70 gene expression. These observations sugges t the possibility that in certain human tissues, basal expression of t he hsp70 and hsc70 genes is coregulated.