ADAM17通过EGFR-PI3K/Akt/p27通路调控前列腺癌细胞增殖

ADAM17是金属蛋白酶家族(ADAMs)成员之一,研究发现ADAM17可以通过水解细胞表面蛋白的胞外结构域导致肿瘤细胞的增殖和转移.本课题前期研究结果显示,与LNCap细胞相比,ADAM17在DU145细胞中高表达,且与细胞增殖相关.为了研究ADAM17与前列腺癌细胞增殖相关基因p27表达的关系及调控机制,我们采用RNAi技术下调ADAM17的表达,加入PMA(一种ADAM17的激活剂)上调ADAM17的表达,通过细胞计数和CCK-8方法检测细胞增殖,RT-PCR检测p27mRNA的表达,Western印迹检测ADAM17的表达;进一步阻断EGFR和PI3K/Akt信号转导,RT-PCR方法检测p27mRNA的表达,Western印迹检测ADAM17、EGFR、pEGFR、Akt和pAkt的表达.结果显示ADAM17的表达与前列腺癌细胞的增殖呈正相关(P0.05);p27mRNA的表达与ADAM17的表达呈负相关(P0.05);分别阻断EGFR和PI3K/Akt信号转导通路,同时使ADAM17表达增加,与对照组(单独PMA处理组)相比,p27mRNA的表达均增加(P0.05).提示ADAM17调控前列腺癌细胞增殖相关基因p27表达是通过EGFR-PI3K/Akt信号通路实现的.

ADAM17 Regulates Proliferation via the EGFR-PI3K/Akt/p27 Pathway in Prostate Cancer Cells

A Disintegrin and A Metalloproteinase 17 (ADAM17), a membrane-associated metalloproteinase， is involved in the proteolytic release of the ectodomain of diverse cell surface proteins with critical roles in the tumor proliferation and metastasis. We have previously demonstrated that ADAM17 is highly expressed in DU145 cells, compared with LNCap cells. In this study, we elucidate whether ADAM17 contributes to prostate cancer proliferation and mediates p27 mRNA expression, as well as the mechanism between them in vitro. The results of CCK-8 assay and cell quantification showed that ADAM17 expression correlated with prostate cancer cell proliferation. The results of Western blotting indicated that the expression of ADAM17 was down-regulated by GM6001 or ADAM17-siRNA in DU145, but it was up-regulated by PMA (an activator of ADAM17) in LNCap. Conversely，the result of RT-PCR indicated that p27 mRNA expression was up-regulated by GM6001 or ADAM17-siRNA in DU145, but it was down-regulated by PMA in LNCap. Furthermore, increased p27 mRNA expression level was associated with inhibition of the EGFR-PI3K/Akt signaling pathway, as confirmed by RT-PCR and Western blotting analysis. These results suggest that ADAM17 can mediate prostate cancer cell proliferation and P27 gene expression via EGFR-PI3K/Akt pathway.