Leiomyomata Uteri: Apoptosis and Cell Survival Pathways

描述（由申请人提供）：平滑肌瘤是子宫平滑肌细胞的良性单克隆增生，每三个育龄妇女中就有一个发生。20% - 50%的女性平滑肌瘤患者会出现异常出血、骨盆疼痛和压力、尿频、生育能力下降和流产等症状。在美国，子宫肌瘤是子宫切除术的主要指征。症状的发展和严重程度与肿瘤的大小和位置有关。子宫平滑肌瘤细胞的增殖超过一定数量的细胞凋亡，导致肿瘤增大。我们实验室的研究已经证明了细胞毒性基因治疗方法的有效性，这种方法可以诱导细胞凋亡，从而减少平滑肌瘤的增殖和体积，使用的是人平滑肌瘤细胞和来源于Eker大鼠品系的平滑肌瘤细胞（ELT-3细胞）。一个强大的旁观者效应被证明，转染一小部分平滑肌瘤细胞能够介导未转染细胞的显著细胞死亡和子宫平滑肌瘤的体内肿瘤消退。在体外实验中，雌激素受体拮抗剂三酚二苯乙烯白藜芦醇可抑制低雌激素环境下子宫平滑肌瘤细胞系的增殖。子宫平滑肌瘤通常表现出很少的细胞凋亡，尽管有证据表明细胞凋亡的内在和外在途径的细胞介质都表达。与正常肌层相比，抗凋亡因子Bcl-2在平滑肌瘤细胞中高表达。雌激素降低Bcl-2蛋白表达，孕激素升高Bcl-2蛋白表达。体内施用GnRH激动剂可显著减少平滑肌瘤大小，但无细胞凋亡迹象。相反，在体外将平滑肌瘤细胞暴露于GnRH激动剂会引起明显的细胞凋亡，并诱导Fas和Fas配体。我们提出以下具体目的：具体目的一：研究HSV-tk/更昔洛韦、er - α受体拮抗剂白藜芦醇和GNRH激动剂对ELT-3和人平滑肌瘤细胞增殖和凋亡的影响。特异性目的二：研究HSVtk/更昔洛韦、膳食er - α受体拮抗剂白藜芦醇、GNRH激动剂对ELT-3/裸鼠平滑肌瘤模型细胞增殖和凋亡的影响。目的三：研究HSV-tk/更昔洛韦、er - α受体拮抗剂白藜芦醇和GNRH激动剂对异种人平滑肌瘤模型细胞增殖和凋亡的影响。详细了解子宫平滑肌瘤中活跃的细胞凋亡和细胞存活途径，将使我们更好地促进长期肿瘤消退，以应对不断发展的子宫平滑肌瘤微创治疗，包括血管栓塞，高强度聚焦超声，以及不断发展的靶向分子和药物治疗。

DESCRIPTION (provided by applicant): Leiomyomas are benign monoclonal proliferations of uterine smooth muscle cells occurring in one of every three women of reproductive age. Twenty to fifty percent of women with leiomyomas develop symptoms including abnormal bleeding, pelvic pain and pressure, urinary frequency, reduced fertility and miscarriage. Leiomyomas represent the leading indication for hysterectomy in the United States. The development and severity of symptoms is related to the size and position of the tumors. The proliferation of uterine leiomyoma cells exceeds the limited number of cells undergoing apoptosis resulting in tumor enlargement. Studies from our laboratory have demonstrated the effectiveness of a cytotoxic gene therapy approach known to induce apoptosis to reduce leiomyoma proliferation and volume using human leiomyocytes and leiomyoma cells derived from the Eker rat strain (ELT-3 cells). A strong bystander effect was demonstrated where transfection of a small percentage of leiomyoma cells was able to mediate marked cellular death of the non transfected cells and in vivo tumor regression of uterine leiomyomas. In vitro experiments using the dietary triphenolic stilbene resveratrol, an estrogen alpha receptor antagonist, inhibited proliferation of the ELT-3 uterine leiomyoma cell line in a hypoestrogenic environment. Uterine leiomyomas generally exhibit minimal apoptosis despite evidence that cellular mediators of both the intrinsic and extrinsic pathways of apoptosis are expressed. The anti-apoptosis factor Bcl-2 is highly expressed in leiomyoma cells in comparison to normal myometrium. Bcl-2 protein expression is reduced by estrogen exposure and increased by progesterone exposure. GnRH agonists administered in vivo cause a marked reduction in leiomyoma size without evidence of apoptosis. In contrast, in vitro exposure of leiomyoma cells to GnRH agonists causes marked apoptosis and induction of Fas and Fas ligand. We propose the following Specific Aims: Specific Aim I: To study the effect of HSV-tk/ganciclovir, the dietary ER-alpha receptor antagonist resveratrol, and GNRH agonist on cell proliferation and apoptosis in ELT-3 and human leiomyoma cells. Specific Aim II: To study the effect of HSVtk/ ganciclovir, the dietary ER-alpha receptor antagonist resveratrol, and GNRH agonist on cell proliferation and apoptosis in the ELT-3/nude mouse model of leiomyoma. Specific Aim III: To study the effect of HSV-tk/ganciclovir, the dietary ER-alpha receptor antagonist resveratrol and GNRH agonist on cell proliferation and apoptosis in a human leiomyoma xenograft model. A detailed understanding of the apoptosis and cell survival pathways active in uterine leiomyomas will allow us to better promote long term tumor regression in response to evolving minimally invasive therapies in development for uterine leiomyomas including vascular embolization, high intensity focused ultrasound, and evolving targeted molecular and pharmacologic therapies.