JAK2/STAT3信号传导通路在瘦素促进子宫内膜癌细胞增殖中的作用

The Role of JAK2/STAT3 Signaling Pathway in Leptin Promoting the Proliferation of Human Endometrial Cancer Cells

目的 探讨JAK2／STAT3信号传导通路在瘦素促进子宫内膜癌细胞（Ishikawa细胞）增殖中的作用。方法 免疫荧光染色法检测瘦素受体（OB-Rb）在Ishikawa细胞的表达。Ishikawa细胞分别用不同浓度的瘦素（0、10、50、100、150ng／ml）作用不同的时间（6、12、24h）后，MTT法检测各组细胞的增殖情况；另应用不同浓度（0、25、50、100umol／L）JAK2激酶特异性抑制剂AG490阻断STAT3磷酸化后，采用MTT法检测瘦素对Ishikawa细胞增殖的影响；瘦素（100ng／ml）作用Ishikawa细胞不同时间（0、20、40、60min）后，采用免疫印迹法（Western blot）检测细胞STAT3磷酸化水平。结果 免疫荧光染色证实Ishikawa细胞膜存在OB-Rb的表达；瘦素能明显促进Ishikawa细胞的增殖，在0～100ng／ml范围内呈剂量依赖性，于150ng／ml瘦素作用24h时细胞增殖效应最大；AG490可明显抑制瘦素对Ishikawa细胞的促增殖作用，呈剂量依赖性；Ishikawa细胞经100ng／ml瘦紊处理后，随时间的延长，STAT3活化程度逐渐增高，至少可持续60min。结论 瘦素可能通过激活JAK2／STAT3信号传导通路促进子宫内膜癌细胞的增殖。

Objective To explore the role of JAK/STAT3 signaling pathway in leptin promoting the proliferation of human endometrial cancer cells. Methods The expression of leptin receptor （OB-Rb） was detected by immunofluorescence staining. The ceils after serum starvation were treated with leptin at different concentrations （0, 10, 50, 100, 150 ng/ml） for different time （6, 12, 24 h）. The effect of leptin on cell proliferation was assayed by MTT method. AG490, a selective inhibitor of JAK2, with different concentrations （0, 25, 50, 100 umol/L）, was used to block the phosphorylation of STAT3. The proliferation of Ishikawa cells was tested by MTT. After leptin （100 ng/ml） treatment for various time （0, 20, 40, 60 min）, the phosphorylation level of STAT3 was examined by Western blot. Results Immunofluorescence staining showed that OB-Rb was expressed on the membrane of Ishikawa cells. Leptin （0-100 ng/ml） stimulated the proliferation of Ishikawa cells in a dosedependent manner, and the effect was maximal after leptin （150 ng/ml） treatment for 24 h. AG490 significantly suppressed the proliferation of Ishikawa cells induced by leptin in a dose-dependent manner. The phosphorylation level of STAT3 was significantly increased in Ishikawa cells after leptin treatment and could last for 60 min at least. Conclusion Leptin may promote the proliferation of endometrial cancer cells by activating JAK2/STAT3 signaling pathway.