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

To know the role of sex hormone-binding globulin (SHBG) in the intrace llular steroidal actions in human ovarian cancers, the expression of S HBG mRNA as a substitute for intracellular SHBG expression was investi gated in normal ovarian tissues and ovarian tumors. In the present stu dy, we used competitive reverse transcription-polymerase chain reactio n-Southern blot analysis to evaluate SHBG mRNA levels. The expression of SHBG mRNA was detected in all normal ovaries and benign and maligna nt ovarian tumors analyzed. There were no significant differences in t he mean SHBG mRNA levels among the three types of tissue. The expressi on in normal ovaries was significantly higher (p < 0.01) in premenopau se, suggesting the predominance of a sex steroid hormone effect on ova rian SHBG synthesis. Relative overexpression of SHBG mRNA was observed in six out of 22 cases (27%) of ovarian cancer (three cases of endome trioid adenocarcinoma, two cases of serous cystadenocarcinoma and one case of mucinous cystadenocarcinoma) in comparison with normal ovaries and benign ovarian tumors. There was no difference in expression amon g the clinical stages of ovarian cancers. These data suggest that norm al human ovaries and ovarian tumors might synthesize SHBG intracellula rly, ovarian cancers might conserve an estrogen-associated property vi a SHBG and the regulation of intracellular SHBG expression might be ch anged in some cancers.