EXPRESSION OF SEX-HORMONE BINDING GLOBULIN EXON-VII SPLICING VARIANT MESSENGER-RNA IN HUMAN UTERINE ENDOMETRIAL CANCERS

We have demonstrated the intracellular expression of sex hormone-bindi ng globulin (SHBG) exon VII splicing variant mRNA in human uterine end ometrial cancer using the reverse transcription-PCR-Southern blot and DNA sequencing analyses, Analysis of the missing base pairs proved tha t they corresponded to the entire exon VII, which is considered to enc ode a portion of the steroid-binding site, suggesting that the steroid -binding affinity of this variant might be different from that of the SHBG wild type. In uterine endometrial cancers, the wild-type mRNA lev els significantly (P < 0.01) decreased, and the ratio of the SHBG vari ant to wild-type mRNA levels (P < 0.01) increased with the advance of histological dedifferentiation. These results suggest that dedifferent iation of endometrial cancers might induce a reduction in their estrog en-dependent properties via intracellular SHBG.