CALCIUM SIGNALING AND OVARIAN CANCER

卵巢癌是导致癌症死亡的主要原因之一 女人。卵巢癌患者的低存活率(不到13 III期疾病的百分比)在很大程度上反映了 卵巢腺癌的侵袭性和转移性。尽管 卵巢癌的严重性显而易见，人们对此知之甚少 卵巢表面上皮细胞的正常生物学 上升为最恶性的卵巢癌。提供的数据 在这项建议中指出，增加的细胞外钙施加 对卵巢表面上皮细胞有显著的增殖作用， 通过胸腺嘧啶核苷掺入和细胞生长曲线测定。 卵巢表面上皮细胞表达信使核糖核酸和蛋白 最近克隆了钙敏感受体(CAR)。这个G蛋白偶联 受体已被证明负责触发甲状旁腺激素 甲状旁腺细胞对细胞外激素升高的反应 钙。我们已经证明了卵巢表面上皮细胞中的CAR 对细胞外钙和钙的功能反应相同 其他激动剂(包括Gd)和甲状旁腺汽车一样。 卵巢表面上皮细胞中CAR的激活与 随着酪氨酸磷酸化的增加，该酶的活性增强 丝裂原激活的激酶ERK2，并增加src的活性。 表达CAR的非功能突变体(R796W)可抑制 观察到酪氨酸磷酸化和ERK2活性增加 对CAR激动剂的反应，表明存在 对于这些增加的响应，需要功能正常的汽车 细胞外钙。此外，我们观察到，四个中的两个 被检测的卵巢肿瘤细胞系似乎过表达CAR mRNA，因为 以及表达一部新奇的汽车成绩单。这些卵巢肿瘤细胞 在低钙介质中，品系不再受到生长抑制。这 该提议基于以下假设：信号转导在下游 CAR的激活直接导致ERK激酶的激活和增加 增殖以及正常CAR表达和/或中断 功能导致卵巢失去正常的生长控制 致癌。这些假设将通过1)颠覆已知的方式进行检验 信号转导机制及对汽车依赖影响的观察 利用显性负性转染法激活src和/或ERK2 突变体或选择性化学抑制剂，2)使用前瞻性研究 卵巢癌患者CAR表达的临床意义 关联性。

Ovarian carcinoma is one of the leading causes of cancer death among women. The low survival for victims of ovarian cancer (less than 13 percent for stage III disease) reflect, in large part, the highly aggressive and metastatic character of ovarian adenocarcinomas. Despite the obvious seriousness of ovarian cancer, very little is known about the normal biology of the ovarian surface epithelial cells which give rise to the most malignant forms of ovarian carcinoma. Data presented in this proposal indicate that increased extracellular calcium exerts a significant proliferative effect on ovarian surface epithelial cells, as measured by both thymidine incorporation and cell growth curves. Ovarian surface epithelial cells express mRNA and protein for the recently cloned Calcium-sensing Receptor (CaR). This G-protein coupled receptor has been shown to be responsible for triggering parathormone release from parathyroid cells in response to elevated extracellular calcium. We have shown that the CaR in ovarian surface epithelial cells displays the same functional responses to extracellular calcium and other agonists (including gadolinium) as does the parathyroid CaR. Activation of the CaR in ovarian surface epithelial cells is associated with increases in tyrosine phosphorylation, increased activity of the mitogen-activated kinase ERK2, and increased src kinase activity. Expressing a non-functional mutant of the CaR (R796W) inhibited the increases in tyrosine phosphorylation and ERK2 activity observed in response to agonists of the CaR, indicating that the presence of functional CaR is required for these responses to increased extracellular calcium. Furthermore, we have observed that two of four ovarian tumor cell lines examined appear to over-express CaR mRNA, as well as expressing a novel CaR transcript. These ovarian tumor cell lines are no longer growth-inhibited in low calcium media. This proposal is based on the hypotheses that signal transduction downstream of the CaR leads directly to activation of ERK kinase and increased proliferation, and that disruption of normal CaR expression and/or function contributes to the loss of normal growth controls in ovarian carcinogenesis. These hypotheses will be tested by 1) disrupting known signaling mechanisms and observing the effect on CaR-dependent activation of src and/or ERK2, using transfection of dominant negative mutants or selective chemical inhibitors, 2) using a prospective study of CaR expression in patients with ovarian cancer to test clinical relevance.