Association of the AHSG polymorphism with genetic susceptibility to stage IV endoametriosis and expression of aromatase P450 in eutopic and ectopic endometrium

Objective:To explore the possible association between polymorphism at AHSG gene and stage Ⅳ endometriosis and expression of aromatase P450 in eutopic and ectopic endometrium.Methods:The genetic polymorphism of AHSG were analyzed by polymerase chain reaction(PCR) technique in peripheral blood leukocytes in 50 stage Ⅳ endometriosis(ovary chocolate cysts) and 62 non-endometriosis cases.The expression of aromatase P450 was detected by immunohistochemical analysis for eutopic and ectopic endometrium in 50 Ⅳ endometriosis patients and 62 controls.Results:Among 50 patients with stage Ⅳ endometriosis(ovary chocolate cysts) and 62 controls,the frequency of AHSG 1*1,AHSGI*2,AHSG2*2 was 44%,46%,10% and 71%,25.8%,3.2%,respectively.Combined genotype of AHSG1*2 and AHSG2*2,then compared it with the wide-type.A statistic difference was found between the two groups.(χ2=8.317,P=0.004) OR=3.111(95%CI:1.422～6.805).Statistic analysis suggested AHSG genotype polymorphism increased risk of stage Ⅳ endometriosis(ovary chocolate cysts).AHSG*1,AHSG*2 alleles differed significantly between the two groups(χ2=8.723,P=0.003) with OR=2.561,(95% CI:1.358～4.831),which suggested that AHSG*2 allele increased risk of stage Ⅳ endometriosis(ovary chocolate cysts).Expression of aromatase P450 in eutopic endometrium in stage Ⅳ endometdosis(histochemistry score 2.1±1.2) was significantly higher than that in control group(0.9±1.1)(P0.01).Expression of aromatase P450 in ectopic endometrium in stage Ⅳ endometriosis(histochemistry score 1.5±1.0) was significenfly lower than that in eutopic endometrium(P0.05).Conclusion:AHSG polymorphism is highly associated with the genetic susceptibility to stage Ⅳ endometriosis.The increased expression of aromatase P450 in eutopic and ectopic endometrium in stage Ⅳ endometriosis can promote the growth and implantation of endometriosis.