CALCIUM SIGNALING AND OVARIAN CANCER

钙信号传导与卵巢癌

基本信息

批准号：
6554346
负责人：
Karin D Rodland
金额：
$ 22.59万
依托单位：
BATTELLE PACIFIC NORTHWEST LABORATORIES
依托单位国家：
美国
项目类别：
财政年份：
1998
资助国家：
美国
起止时间：
1998-07-01 至 2004-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/6554346
关键词：
calcium binding protein calcium flux cell proliferation clinical research enzyme activity female gene induction /repression human genetic material tag human subject mitogen activated protein kinase neoplasm /cancer genetics ovary neoplasms phosphatidylinositol 3 kinase protein structure function protooncogene tissue /cell culture

项目摘要

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.

卵巢癌是导致癌症死亡的主要原因之一女性。卵巢癌受害者的生存率较低（少于13 III期疾病的百分比）在很大程度上反映了高度卵巢腺癌的侵略性和转移性。尽管卵巢癌的明显严重性，对卵巢表面上皮细胞的正常生物学，该细胞给出升至最恶性的卵巢癌。显示的数据在此提案中表明，细胞外钙的施加增加对卵巢表面上皮细胞的显着增殖作用，通过胸苷掺入和细胞生长曲线测量。卵巢表面上皮细胞表达mRNA和蛋白质最近克隆的钙感应受体（CAR）。该G蛋白结合已证明受体是触发副抑制的原因从甲状旁腺细胞中释放出较高的细胞外细胞钙。我们已经表明卵巢表面上皮细胞中的汽车显示对细胞外钙的相同功能响应和其他激动剂（包括gadolinium）和甲状旁腺一样。卵巢表面上皮细胞中汽车的激活与随着酪氨酸磷酸化的增加，有丝分裂原激活的激酶ERK2，并增加了SRC激酶活性。表达汽车的非功能突变体（R796W）抑制了酪氨酸磷酸化和ERK2活性的增加对汽车激动剂的反应，表明存在这些响应需要功能性汽车才能增加细胞外钙。此外，我们观察到四个检查的卵巢肿瘤细胞系似乎过表达汽车mRNA，如以及表达新颖的汽车成绩单。这些卵巢肿瘤细胞低钙培养基中不再抑制生长生长。这提案基于下游信号转导信号的假设汽车直接导致ERK激酶的激活并增加增殖，并破坏正常的汽车表达和/或功能导致卵巢正常生长控制的丧失致癌作用。这些假设将通过1）破坏已知信号传导机制和观察对汽车依赖性的影响使用显性负的转染SRC和/或ERK2的激活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表达以测试临床关联。