EXPRESSION OF SEX HORMONE-BINDING GLOBULIN MESSENGER-RNA IN HUMAN ENDOMETRIAL CANCERS

To more fully understand the role of sex hormone-binding globulin (SHB G) on the intracellular steroidal action in endometrial cancers, we in vestigated the expression of SHBG mRNA as the substitute of SHBG expre ssion in human endometrial cancers. In the present study, the levels o f SHBG mRNA were analyzed using competitive reverse transcription-poly merase chain reaction (RT-PCR)-Southern-blot analysis. The higher leve l of SHBG mRNA tended to be expressed in the normal secretory and late proliferative phase endometrium > early proliferative phase endometri um > well differentiated adenocarcinoma of the endometrium (G1) > mode rately differentiated adenocarcinoma (G2) > poorly differentiated aden ocarcinoma (G3), in the order shown. These studies indicate that endom etrial cancer cells might synthesize intracellular SHBG to conserve th eir estrogen-dependent properties. Further, it indicates that endometr ial cancer cell synthesis of SHBG mRNA is lost as these cells undergo de-differentiation.