EXPRESSION OF SEX HORMONE-BINDING GLOBULIN MESSENGER-RNA IN UTERINE LEIOMYOMA, MYOMETRIUM AND ENDOMETRIUM OF HUMAN-SUBJECTS

This study tvas designed to evaluate the effect of sex hormone-binding globulin (SHBG) on the estrogen-dependent growth of human uterine lei omyoma. Levels of SHBG mRNA were analyzed using competitive reverse tr anscription-polymerase chain reaction-Southern blot analysis (RT-PCR-S BA). In normal uterine endometria, the levels of SHBG mRNA in the earl y/mid and late proliferative phases of the menstrual cycle were signif icantly lower than in the secretory phase (p < 0.01). In uterine myome tria and leiomyomas, SHBG mRNA level showed no significant differences during the menstrual cycle, while the ratio of leiomyoma SHBG level t o the corresponding myometrium SHBG level was > 1 in 21 out of 23 case s (91%). Our results suggest that steroidal regulation of intracellula r SHBG synthesis in the myometrium and the leiomyoma might differ from that in the endometrium, and that the mechanism of SHBG expression in leiomyoma might, in the process of tumorigenesis, be altered from tha t of corresponding normal myometrium, contributing to SHBG overexpress ion and the abundant estrogen supply.