目的：探讨IL6诱导卵巢癌细胞对他莫西芬（tamoxifen，TAM）耐药的分子机制。方法：构建内源性过表达IL6的人卵巢癌A2780细胞系和内源性抑制IL6表达的人卵巢癌CAOV3细胞，50 ng/ml外源性IL6预处理A2780细胞(A2780/preIL6细胞)，Western blotting检测内/外源IL6对卵巢癌细胞ERα Ser167位磷酸化水平的影响；IL6与PI3K抑制剂Wortmannin单独或联合作用于A2780细胞，Western blotting检测其对A2780细胞Akt磷酸化和ERα磷酸化的影响；MTT法检测Wortmannin和内/外源IL6对A2780细胞TAM敏感性的影响；荧光素酶报告基因检测卵巢癌细胞ERα的转录活性，并分析其可能涉及的信号通路。结果：外源性及内源性过表达IL6可明显促进A2780细胞ERα Ser167位点磷酸化水平（均P<001），而内源性抑制IL6表达则可降低CAOV3细胞ERα Ser167位点的磷酸化水平（P<0.01）；Wortmannin可阻断IL6诱导的A2780细胞对TAM的耐药及ERα的磷酸化（P<0.05）； IL6可促进细胞ERα的转录活性（P<0.01），而Wortmannin并不能阻断IL6对ERα的转录活性的影响（P>0.05）。结论：IL6可经PI3K/Akt通路引起ERα磷酸化从而活化ER信号通路，进而诱导卵巢癌细胞对TAM耐药。

Objective:This study aimed to explore the mechanism of tamoxifen (TAM) resistance caused by IL6 in ovarian cancer cells. Methods: Human ovarian cancer A2780 cell line that endogenously overexpressing IL6 and human ovarian cancer CAOV3 cell line that exogenously depleting IL6 were constructed; exogenous IL6 (50 ng/ml) were used for pretreatment of A2780 cells (A2780/perIL6 cells), and Western blotting was used to detect the effect of endogenous/exogenous IL6 on the phosphorylation level of ERα Ser167 in ovarian cancer cells; IL6 and/or Wortmannin (PI3K inhibitor) were used to treat A2780 cells and western blotting was used to detect their effect on the phosphorylation of Akt and ERα; MTT assay was used to detect the effect of Wortmannin and endogenous/exogenous IL6 on the sensitivity of A2780 cells to TAM; luciferase reporter assay was performed to detect transcription activity of ERα in ovarian cancer cells, and to explore the possible signaling pathway. Results: Both exogenous and endogenous overexpression of IL6 could obviously increase the level of ERα Ser167 phosphorylation in A2780 cells (all P<0.01), while endogenous depletion of IL6 could reduce the level of ERα Ser167 phosphorylation in CAOV3 cells (P<0.01). It also found that wortmannin (PI3K inhibitor) could significantly antagonize IL6induced TAM resistance and phosphorylation of ERα Ser167. IL6 promoted ERa transcription activity, while this activation was not blocked by the PI3Kspecific inhibitor wortmannin. Conclusion: These results indicate that IL6 could induce ERa phosphorylation by triggering PI3K/Akt signaling pathway to activate the ER pathway, and thereby induce the resistance of ovarian cancer cells to TAM.

国家自然科学基金资助项目（No. 81572852, No.81502256）；天津市自然科学基金资助项目（No. 12JCZDJC26300 ）；武警后勤学院科学技术研究资助项目（No. 2015ZXKF05,No.WHB201404, No.WHB201505）