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殖，每三名育龄妇女中就有一名发生。20%到50%的女性平滑肌瘤患者会出现异常出血、骨盆疼痛和压迫、尿频、生育能力下降和流产等症状。平滑肌瘤是美国子宫切除术的主要适应症。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了有限数量的细胞凋亡，导致肿瘤扩大。我们实验室的研究已经证明了已知的细胞毒性基因治疗方法的有效性，该方法可以诱导细胞凋亡，从而使用人平滑肌细胞和来自Eker大鼠品系的平滑肌瘤细胞（ELT-3细胞）减少平滑肌瘤增殖和体积。一个强大的旁观者效应被证明，其中一小部分的平滑肌瘤细胞的转染能够介导显着的非转染细胞的细胞死亡和子宫平滑肌瘤的体内肿瘤消退。在体外实验中，使用膳食三酚芪白藜芦醇，雌激素α受体拮抗剂，抑制增殖的ELT-3子宫平滑肌瘤细胞系在低雌激素的环境。子宫平滑肌瘤通常表现出最小的细胞凋亡，尽管有证据表明，细胞介质的内在和外在途径的细胞凋亡的表达。与正常子宫肌层相比，抗凋亡因子Bcl-2在平滑肌瘤细胞中高度表达。Bcl-2蛋白表达减少雌激素暴露和增加孕激素暴露。体内给予GnRH激动剂可导致平滑肌瘤大小显著减小，但无细胞凋亡迹象。与此相反，在体外暴露的平滑肌瘤细胞GnRH激动剂引起显着的凋亡和诱导Fas和Fas配体。我们提出以下具体目的：具体目的I：研究HSV-tk/更昔洛韦、膳食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。具体目标二：研究HSVtk/更昔洛韦、ER-α受体拮抗剂白藜芦醇和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。具体目标三：研究HSV-tk/更昔洛韦、ER-α受体拮抗剂白藜芦醇和GNRH激动剂对人平滑肌瘤异种移植模型细胞增殖和凋亡的影响。详细了解子宫平滑肌瘤中的细胞凋亡和细胞存活途径将使我们能够更好地促进长期肿瘤消退，以应对子宫平滑肌瘤发展中不断发展的微创治疗，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.