Autocrine stimulation of IGF1 in estrogen-induced growth of endometrial carcinoma cells: involvement of the mitogen-activated protein kinase pathway followed by up-regulation of cyclin D1 and cyclin E
Autocrine stimulation of IGF1 in estrogen-induced growth of endometrial carcinoma cells: involvement of the mitogen-activated protein kinase pathway followed by up-regulation of cyclin D1 and cyclin E
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DOI：
10.1677/erc-08-0117
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发表时间：
2009-03-01
影响因子：
3.9
通讯作者：
Konishi, Ikuo
中科院分区：
文献类型：
--
作者：
Kashima, Hiroyasu;Shiozawa, Tanri;Konishi, Ikuo
为了研究雌激素诱导的子宫内膜癌生长机制，我们研究了雌激素诱导的丝裂原活化蛋白激酶（MAPK）通路和细胞周期调节因子的激活。用10（-8）M和10（-6）M的雌二醇（E-2）处理雌激素受体（ER）阳性的子宫内膜癌石川细胞24 h，细胞增殖分别增加20%和28%。E-2诱导的细胞增殖与细胞外信号调节激酶（MAPK）3/1的激活和细胞周期蛋白D1和E的上调有关，而MAPK 2K抑制剂（U 0126）或ER拮抗剂（ICI 182 780）可抑制细胞增殖。然后，我们的筛选雌激素诱导的生长因子确定，IGF 1的上调显着的E-2。用E-2处理后的石川细胞的条件培养基进行的免疫沉淀证实了E-2诱导的IGF 1蛋白的分泌。重组IGF 1处理以剂量依赖性方式刺激细胞增殖，与MAPK 3/1磷酸化和细胞周期蛋白D1和E的上调相关。这些IGF 1诱导的反应被MAP 2K抑制剂或抗IGF 1受体抗体抑制。免疫组化染色证实了活化的MAPK 3/1在正常增殖期子宫内膜癌和子宫内膜癌中的表达，表明该途径参与了体内活跃增殖的子宫内膜组织。这些结果表明，E2诱导的子宫内膜癌细胞的增殖是通过MAPK 3/1途径介导的IGF 1的自分泌刺激。
To examine estrogen-induced growth mechanisms of endometrial carcinoma, we investigated the estrogen-induced activation of the mitogen-activated protein kinase (MAPK) pathway and cell cycle regulators. Estradiol (E-2) treatment at concentrations of 10(-8) M and 10(-6) M to estrogen receptor (ER)-positive endometrial carcinoma Ishikawa cells for 24 h resulted in increased cell proliferation by 20% and 28% respectively. The E-2-induced proliferation was associated with the activation of extracellular signal-regulated kinase (MAPK)3/1 and up-regulation of cyclin D1 and E, which were suppressed by the addition of an MAP2K inhibitor (U0126) or an ER antagonist (ICI 182 780). Then, our screening for estrogen-inducible growth factors identified that IGF1 was up-regulated remarkably by E-2. Immunoprecipitation using conditioned medium of Ishikawa cells after E-2 treatment confirmed the E-2-induced secretion of IGF1 protein. Treatment with recombinant IGF1 stimulated cell proliferation in a dose-dependent fashion, in association with MAPK3/1 phosphorylation and up-regulation of cyclin D1 and E. These IGF1-induced responses were suppressed by treatment with MAP2K inhibitor or anti-IGF1 receptor antibody. Immunohistochemical staining confirmed the expression of activated MAPK3/1 in normal proliferative phase endometria and endometrial carcinomas, indicating the involvement of this pathway in actively proliferating endometrial tissues in vivo. These findings suggest that E2-induced proliferation of endometrial carcinoma cells is mediated by the MAPK3/1 pathway via autocrine stimulation of IGF1.