자궁내막증 환자와 정상 여성의 자궁내막에서 Pleiotrophin (PTN)과 Midkine (MK) mRNA 발현 차이에 관한 연구

Endometrium from Women with Endometriosis Expresses Increased Levels of Pleiotrophin (PTN) and Midkine (MK) mRNA Compared to Normal Endometrium

자궁내막증은 흔한 부인과적 질병이며 여성 불임의 한 원인이 되나 그 발생 원인에 대하여서는 아직 논란의 여지가 많다. 최근 월경혈의 역류에 의하여 자궁내막증이 생긴다는 가설이 가장 유력한데 자궁내막증 환자가 정상여성에서보다 역류되는 월경혈의 양이 많거나 침습성이 강한 것이 자궁내막증의 발생원인이 될 수 있다는 이론들이 소개되었다. Pleitrophin (PTN)이나 midkine(MK)은 성장 및 분화에 관여하는 인자로서 여러 종류의 악성 종양에서 그 발현이 보고되어있으며 종양화 (carcinogenensis), 맥관형성 (angiogenesis), plasminogen activator의 활성화 증가 등에 관여한다고 보고된 바 있다. 이에 자궁내막증 환자의 자궁 내막과 대조군의 자궁내막에서 PTN과 MK mRNA의 발현의 차이를 quantitative competitive RT PCR로 비교하였다. 그 결과 자궁내막증 환자의 황체기 자궁내막에서 대조군의 자궁내막에 비하여 PTN과 MK의 발현이 높게 나타났다. 이러한 PTN과 MK의 발현의 증가로 자궁내막증 환자의 자궁내막이 복강 내에서 더욱 쉽게 맥관형성을 하고 성장이 촉진되어 자궁내막증이 발생될 것으로 생각되어 PTN과 MK가 자궁내막증의 초기 발생과정에 관여할 가능성이 있다.

Objectives: The pleiotrophin (PTN) and midkine (MK) are secreted heparin-binding neurokines that share 50％ sequence homology. PTN and MK are expressed in the range of primary human tumors. The association of PTN and MK with carcinogenesis, enhancement of plasminogen activator activity and angiogenic factor are reported. Patients with endometriosis are characterized by the ability of the endometrium to implant; angiogenic and growth factors may play a significant role in the pathogenesis of endometriosis. To test the hypothesis that higher expression of PTN and MK in endometrium from women with endometriosis might be increase angiogenesis and growth ectopic endometriosis implants, we investigated PTN and MK expression by quantitative and competitive polymerase chain reaction (QC-PCR) in endometrium from women with and without endometriosis throughout the menstrual cycle. Design: MK and PTN mRNA expression in endomeoium from women with endometriosis and control patients without endometriosis were determined by QC-PCR throughout the menstrual cycle. Methods: Endometrial tissue was obtained from 25 patients with severe endometriosis and 30 patients without endometriosis undergoing hysterectomy or endometrial biopsy. Stage of endometrial cycle and a diagnosis of endometriosis were confirmed histologically. Total RNA was extracted and reverse transcribed into c-DNA. QC-PCR was performed to evaluate PTN and MK mRNA expression. Results were analysed by Post Hoc test. Results: MK and PTN were expressed throughout the menstrual cycle in both groups. MK expression was higher in follicular phase than luteal phase in endometrium from normal women. endometrium from endometriosis patients showed increased expression of PTN and MK compared to endometrium from normal women in the luteal phase (p<0.05). Conclusion: Our results suggest that uterine endometrium from women with endometriosis expresses higher levels of MK and PTN than endometrium from normal women during luteal phase. Increased MK and PTN expression may be related to the initiation of ectopic endometrial implants and their subsequent peritoneal invasion.