Leiomyomata Uteri: Apoptosis and Cell Survival Pathways

描述(申请人提供)：子宫肌瘤是子宫平滑肌细胞的良性单克隆性增殖，发生在每三名育龄妇女中的一名。患有子宫肌瘤的女性中有20%到50%会出现异常出血、盆腔疼痛和压力、尿频、生育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。子宫肌瘤细胞的增殖超过了细胞凋亡的限制，导致肿瘤增大。我们实验室的研究已经证明了一种已知的细胞毒基因治疗方法的有效性，该方法可以通过诱导细胞凋亡来减少肌瘤的增殖和体积，使用的是人肌细胞和来源于Eker大鼠品系的肌瘤细胞(ELT-3细胞)。少数子宫肌瘤细胞的转染组出现了较强的旁观者效应，未转染组细胞明显死亡，子宫肌瘤体内肿瘤消退。在低雌激素环境下，饮食中使用雌激素α受体拮抗剂二苯乙烯类白藜芦醇的体外实验抑制了ELT-3子宫肌瘤细胞系的增殖。子宫肌瘤通常表现出极少量的细胞凋亡，尽管有证据表明内在和外在凋亡途径的细胞介质都有表达。与正常子宫肌层相比，抗凋亡因子Bcl2在子宫肌瘤细胞中高表达。Bcl2蛋白的表达因雌激素暴露而减少，而因孕激素暴露而增加。体内应用促性腺激素释放激素激动剂可显著缩小肌瘤大小，但未发现细胞凋亡的迹象。相反，在体外，子宫肌瘤细胞暴露于GnRH激动剂会导致显著的细胞凋亡和Fas和Fas配体的诱导。具体目的一：研究HSV-tk/Ganciclovir、饲料中ER-α受体拮抗剂白藜芦醇和GnRH激动剂对ELT-3和人子宫肌瘤细胞增殖和凋亡的影响。特定目的II：研究HSVtk/Ganciclovir、饮食中ER-α受体拮抗剂白藜芦醇和GnRH激动剂对ELT-3/裸鼠子宫肌瘤模型细胞增殖和凋亡的影响。特定目的III：研究HSV-tk/Ganciclovir、饮食中ER-α受体拮抗剂白藜芦醇和GnRH激动剂对人子宫肌瘤移植瘤细胞增殖和凋亡的影响。对子宫肌瘤中活跃的细胞凋亡和细胞存活通路的详细了解将使我们能够更好地促进长期肿瘤消退，以应对不断发展的子宫肌瘤微创治疗，包括血管栓塞术、高强度聚焦超声和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.