雌激素通过激活AKT通路产生的细胞因子增强子宫内膜癌细胞增殖能力

背景与目的：目前认为子宫内膜癌的发生可能与无拮抗的雌激素长期作用有关，但雌激素如何调节细胞增殖的作用机制尚不清楚。AKT信号转导通路是细胞生存和增殖的一个重要调节信号。本研究探讨在子宫内膜癌细胞HEC-1A中，雌二醇能否通过激活AKT通路产生细胞因子，以及其对细胞增殖能力的影响。方法：蛋白质印迹法(Western blot)技术检测雌二醇作用HEC-1A细胞后AKT活化情况，以及AKT抑制剂、ER抑制剂对AKT活化的影响。荧光定量PCR及ELISA技术检测雌二醇(E2组)作用于HEC-1A细胞30 min后；或雌激素受体抑制剂(ER组)、AKT抑制剂(AKT组)分别预处理细胞1 h后再加入雌二醇作用30 min后，细胞内血管内皮生长因子受体(VEGF)、bFGF、IL-8基因mRNA表达及细胞培养上清液中蛋白表达。细胞集落形成实验、流式细胞仪检测细胞周期的变化，CFSE法检测细胞增殖能力。结果：E₂组的AKT活化比值较对照组显著升高(P=0.006 2)，ER组和AKT组的AKT活性比值较E2组显著降低(P=0.006 0和P=0.006 4)，但不能完全抑制雌二醇作用。E₂组的VEGF、bFGF、IL-8 mRNA或蛋白的表达均明显高于对照组(P均<0.01)；在ER组及AKT组中VEGF、bFGF、IL-8 mRNA或蛋白的表达均明显低于E2组(P均<0.05)；雌二醇作用HEC-1A细胞后，细胞增殖数明显增多，细胞周期加快(P均<0.01)。结论：在HEC-1A细胞，雌二醇可能通过激活AKT信号通路产生VEGF、bFGF、IL-8因子，从而增强肿瘤细胞的增殖能力。

Estradiol enhances the proliferation of endometrial cancer cells by producing angiogenesis by activating AKT pathway

Background and purpose: The occurrence of endometrial cancer may be related to the persistent stimulus of endogenous and exogenous estrogen without progesterone antagonist. But how does estrogen regulate cell proliferation is still unknown. AKT pathway is the most important signal transduction way to mediate proliferation in the cells. The main aim was to study whether estradiol induces the expression of VEGF, bFGF and IL-8 in the endometrial cancer HEC-1A cells by activating AKT, and its effect on proliferation. Methods: Western blot was used to detect the expression of AKT protein in HEC-1A cells after estradiol stimulation, AKT inhibitor or ER inhibitor stimulation followed by estradiol. Real-time PCR and ELISA were used to detect the gene and protein expression of VEGF, bFGF and IL-8 in different inhibitors. Cell colony formation assay, flow cytometry and CFSE assay were used to examine the proliferation in HEC-1A cells. Results: The expression of p-AKT protein in HEC-1A cells after stimulation with estradiol was markedly higher than that in the control group (P=0.006 2); the expression of p-AKT protein in AKT inhibitor group and ER inhibitor group were significantly decreased than that in estradiol group (P=0.006 0, P=0.006 4). qPCR and ELISA showed the mRNA and protein expression of VEGF, bFGF, IL-8 in estradiol group were significantly increased than that in control group (P<0.05); The expressions of VEGF, bFGF, IL-8 in AKT inhibitor group and ER inhibitor group were significantly decreased than that in estradiol group (P<0.01). The abilities of proliferation and cell cycle were significantly increased in HEC-1A cells after estradiol stimulation. Conclusion: Estrogen induces the production of VEGF, bFGF and IL-8 through activating AKT signal pathway.