CALCIUM SIGNALING AND OVARIAN CANCER

卵巢癌是癌症死亡的主要原因之一， 妇女 卵巢癌患者的低生存率（低于13 第三阶段疾病的百分比）在很大程度上反映了 卵巢腺癌的侵袭性和转移性。 尽管 卵巢癌的早期症状有哪些？ 卵巢表面上皮细胞的正常生物学， 发展成最恶性的卵巢癌 呈现的数据 在该提议中，表明增加细胞外钙发挥 对卵巢表面上皮细胞有显著的增殖作用， 如通过胸苷掺入和细胞生长曲线测量的。 卵巢表面上皮细胞表达与卵巢癌相关的mRNA和蛋白。 钙敏感受体（CaR）。这种G蛋白 已经证明一种受体负责触发甲状旁腺激素 甲状旁腺细胞对升高的细胞外 钙 我们已经证明卵巢表面上皮细胞中的CaR 对细胞外钙离子表现出相同的功能反应， 其他激动剂（包括钆），如甲状旁腺CaR。 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， 丝裂原活化激酶ERK 2，并增加src激酶活性。 表达CaR的无功能突变体（R796 W）抑制了细胞增殖。 酪氨酸磷酸化和ERK 2活性增加， 对CaR激动剂的反应，表明 功能性CaR是这些反应所必需的， 细胞外钙 此外，我们还观察到， 卵巢肿瘤细胞系检查似乎过表达CaR mRNA， 并表达一种新的CaR转录本。 这些卵巢肿瘤细胞 品系在低钙培养基中不再受到生长抑制。 这 该建议是基于这样的假设，即下游信号转导 直接导致ERK激酶的激活， 增殖和正常CaR表达破坏，和/或 功能导致卵巢中正常生长控制的丧失 致癌作用 这些假设将通过1）破坏已知的 信号转导机制，观察对CaR依赖性 src和/或ERK 2的激活，使用显性阴性转染 突变体或选择性化学抑制剂，2）使用前瞻性研究 卵巢癌患者的CaR表达，以测试临床 本案无关

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.