RELATIVELY HIGH EXPRESSION RATIO OF SEX HORMONE-BINDING GLOBULIN EXON-VII SPLICING VARIANT TO WILD-TYPE MESSENGER-RNA IN HUMAN UTERINE CERVICAL CANCERS

We have demonstrated the intracellular expression of sex hormone-bindi ng globulin (SHBG) exon VII splicing variant mRNA in human uterine cer vical cancer using reverse transcription-polymerase chain reaction-Sou thern blot and DNA sequencing analyses. Analysis of the missing base p airs proved they corresponded to the entire exon VII, which is conside red to encode a portion of the steroid-binding site, suggesting that t he steroid-binding affinity of the variant protein might be different from that of the wild-type SHBG. In uterine cervical cancers, the wild -type mRNA levels were lower (P<0.01) and the ratio of the SHBG varian t to wild-type mRNA levels was higher (P<0.01) than in the normal cerv ix. In cervical adenocarcinomas, the wild-type mRNA levels were higher (P<0.05) and the ratio of the SHBG variant to wild-type mRNA levels w as lower (P<0.05) than in cervical keratinizing squamous cell carcinom as. There was no difference in expression among the clinical stages of cervical cancers. These results suggest that a relative increase of i ntracellular variant SHBG protein in human uterine cervical cancers mi ght be involved in the disruption of the normal estrogen dependence.