蛋白激酶C在人绒毛膜癌JAR细胞中作用的研究

目的：研究蛋白激酶C(protein kinaseC，PKC)对人绒毛膜癌JAR细胞分泌人绒毛膜促性腺激素(hCG)的影响，进一步探讨PKC在调控JAR细胞hCG分泌中的作用。方法：不同浓度的PKC激动剂phorbol 12—myristrate l3—acetate(PMA)急性和慢性刺激、PKC抑制剂chelerythrine chlorine(CHEL)分别作用JAR细胞，用ELASA法测定hCG分泌量变化，以及蛋白印迹(Western blot)法测定细胞内磷酸化丝裂原激活的蛋白激酶(mitogen-activated protein kinase，MAPK)的改变。结果：不同浓度PMA急性刺激时，抑制JAR细胞hCG分泌，在200nmol/L时，其抑制作用最强；不同浓度PMA慢性刺激时，JAR细胞hCG分泌量增加，在200nmol／L时，其作用最强。CHEL作用JAR细胞时，hCG分泌量升高，在600nmol/L时，其作用最强。对照组及各实验组都有活性的MAPK的表达，与对照组相比，PMA慢性刺激组、CHEL组MAPK磷酸化水平升高;PMA急性刺激组MAPK磷酸化水平降低。结论：PKC参与调节JAR细胞hCG的分泌，活性升高时，下调MAPK磷酸化，使JAR细胞hCG分泌减少，而活性降低时，增强MAPK磷酸化，JAR细胞hCG分泌量增加。MAPK通路激活是PKC介导的JAR细胞分泌hCG的重要机制。

Effects of PKC on Human Choriocarcinoma JAR Cell Line

Objective: To study the effects of PKC on hCG secretion in JAR cell and discuss the roles of PKC on the regulation of hCG secretion of JAR cell. Methods: Phorbol 12-myristrate 13-acetate (PMA, a PKC agonist) and chelerythrine chlorine (CHEL, a PKC inhibitor) were added, the hCG secretion of JAR cell was determined by ELASA, and the method of Western blot was used to determine the change of phosphorylation MAPK in JAR cell. Results: Acute treatment with PMA significantly inhibited hCG secretion of JAR cell. The PMA concentration of 200 nmol/L was the most effective while the phosphorylation of MAPK was significantly inhibited. Chronic treatment of PMA significantly increased hCG secretion of JAR cell. Treatment with CHEL significantly increased hCG accumulation in JAR cells, and enhanced the phosphorylation of MAPK. Conclusion: The results indicated that PKC was related to the control of hCG secretion of JAR cell. Downregulation of protein kinase C activity enhanced the phosphorylation of MAPK and stimulated hCG production of JAR cell.