Effects of UPA on Uterine Leiomyoma

Abstract

Uterine leiomyoma is a benign tumor that grows within the muscle tissue of the uterus. Ulipristal acetate (UPA) is a pre-operative drug used for the reducing the size of the myoma. The aim of this study is to examine the in vitro action of UPA on uterine leiomyoma. Patients-derived myoma were primary-cultured and analyzed. Cell viability was measured using cell counting kit (CCK) assay. Doubling time of primary-cultured myoma cells was calculated. EdU assay was performed to determine the rate of proliferation. RT-PCR was executed to determine the mRNA levels of the genes. Flow cytometry (FACS) was employed to evaluate cell cycle. Western immunoassay was performed to determine the expression levels of genes in cell cycle. Treatment of primary-cultured myoma cells with UPA (1 and 10 μM) exhibited delayed cell proliferation rate compared with that of control primary-cultured myoma cells. Doubling time of myoma cells treated with UPA was prolonged compared with that of control myoma cells. FACS analysis revealed delayed cell cycle in UPA-treated primary-cultured myoma cells. To analyze genes involved in cell cycle regulation, the expression levels of both mRNA and proteins of p21, p27, cyclin E, and CDK2 were determined by quantitative RT-PCR and western blot analyses. The mRNA levels of p21 and p27 in UPA-treated myoma cells were significantly elevated compared with those in control myoma cells. And protein level of p27 was observed to be up-regulated. These results suggest that UPA inhibit the growth of uterine myoma through modulating cell cycle regulatory molecules, p21 and p27 resulting in prolongation of the growth rate of myoma, which shows that UPA plays a regulatory role in cell cycle, leading to the suppression of myoma proliferation.

UPA는 자궁근종 성장지연 목적을 위해 쓰이는 약제이다. 자궁근종은 가임기 여성 30% 정도에서 발생하며 과도한 출혈, 통증, 생식기증 장애 등으로 인해 건강뿐만 아니라 경제적으로도 많은 손해를 야기하는 질환이다. UPA가 현재 WHO의 허가를 받은 유일한 자궁근종 성장지연 치료제이지만 정확한 효과 기전이 알려지지 않고 있다. 그러므로 본 연구는 자궁근종세포에서의 UPA 효과를 확인하여 그 정확한 기전을 연구하는 것을 목적으로 하고 있다. 자궁근종으로 수술 받은 환자에서 자궁근종세포를 배양하여 UPA를 투여한 후 자궁근종세포 성장 속도와 세포주기를 측정하여 UPA가 자궁근종세포 doubling time을 증가시키고 세포주기를 연장시키는 효과를 나타냄을 확인하였다. 또한 세포주기 조절 인자인 p21과 p27 발현을 조사한 결과 UPA가 p21과 p27 발현을 증가시킴도 확인하였다. 또한 Western immunoblot 분석을 통해 세포주기 조절 인자인 사이클린 E와 CDK2 발현이 감소함을 확인하였다. 따라서 본 연구는 UPA가 p21과 p27 발현 조절을 통해 세포주기를 증가시켜 자궁근종 성장을 억제한다는 것을 확인하였다. 본 연구 결과는 자궁근종 성장 억제 치료제 개발을 위한 기초 자료를 제공할 것으로 사료된다.