Objective: To investigate the expression of sex hormone-binding globulin (SHBG) exon VII splicing variant messenger RNA (mRNA) in human ovarian endometriosis.
Design: The expression of SHBG variant mRNA in normal uterine endometrium and endometriotic tissue was determined.
Setting: Department of Obstetrics and Gynecology, Gifu University Hospital.
Patient(s): Fourteen women with endometriosis and 18 women without endometriosis.
Intervention(s): Normal uterine endometrial and ovarian endometriotic tissues from patients who had undergone gynecological surgery were studied.
Main outcome measure(s): Levels of SHBG wild-type and variant mRNAs were determined using the quantitative reverse transcription-polymerase chain reaction.
Results(s): Analysis of the missing base pairs proved that they corresponded to the entire exon VII. There was no significant difference between the levels of SHBG wild-type mRNA in normal endometria and in endometriotic endometria, although the levels of SHBG variant mRNA in endometriotic endometria were significantly higher than that in normal endometria. The ratio of SHBG variant to wild-type mRNA levels was significantly higher in endometriotic endometria than in normal endometria.
Conclusion(s): This study demonstrates the coexpression of SHBG exon VII splicing variant mRNA with its wild-type and the dominant expression of the variant in ovarian endometriosis. These results might be involved in the cellular estrogenic interaction, plausibly assisting in the development and growth of ovarian endometriosis.