ADAM17 regulates prostate cancer cell proliferation through mediating cell cycle progression by EGFR/PI3K/AKT pathway Ping Lin • Xicai Sun • Tian Feng • Haifeng Zou • Ying Jiang • Zijun Liu • Dandan Zhao • Xiaoguang Yu Received: 23 March 2011 / Accepted: 27 July 2011 / Published online: 12 August 2011 Ó Springer Science+Business Media, LLC. 2011 Abstract A disintegrin and metalloprotease 17 (ADAM17) is a transmembrane protein that can cleave membrane anchored proteins to release soluble factors and regulate important bio- logical phenomena in cancers. In the present study, we evalu- ated the effects of ADAM17 on the proliferation and on the cell cycle distribution of human prostate cancer cells. Experiments were also performed to gain insights into the possible mecha- nism of action of ADAM17. We used over-expression and RNAi strategy to investigate the function of ADAM17 in human prostate cancer cells. Changes in rate of proliferation and cell cycle profile were measured by growth curve, Cell Counting Kit-8 (CCK-8) assay, bromodeoxyuridine (BrdU) incorporation assay and cell cycle analysis. In addition, changes in expression of associated genes and proteins were studied by semiquantitative RT-PCR, western blotting and ELISA anal- ysis. Ectopic over-expression of ADAM17 resulted in increased cell proliferation. We also showed that ADAM17 promoted G 1 to S phase transition concomitantly with upreg- ulation of cyclin E, CDK2 and downregulation of p21 and p27 proteins. ADAM17 over-expression cells showed that more TGF-a released to the supernatant and activated the EGFR/ PI3K/AKT pathway. Conversely, silencing ADAM17 led to the opposite effect. Both siRNAs knockdown of ADAM17 and blocking the EGFR/PI3K/AKT pathway using specific inhibi- tor caused downregulation of cyclin E, CDK2, and upregulation of p21 and p27 in prostate cancer cells. Collectively, this study demonstrates that over-expression of ADAM17 might target cyclin E, CDK2, p21, and p27 to promote prostate cancer cell proliferation through activation of the EGFR/PI3K/AKT pathway. Keywords ADAM17 Á Prostate cancer Á Cell proliferation Á Cell cycle Á EGFR Á AKT Introduction Prostate cancer is the most common malignancy and the second leading cause of male cancer-related death in the US, accounting for approximately 29% of all cancers diagnosed in males [1]. The primary therapeutic strategies for the treatment of prostate cancer is androgen deprivation [2]. Androgen withdrawal may initially reduce the growth of metastatic prostate cancers; however, the long-term treatment of prostate cancer patients results in loss of responsiveness. Prostate cancer cells finally become androgen independent, leading to the failure of androgen- deprivation therapy and patient death [2, 3]. Thus, under- standing the molecular mechanisms in PC-3 and DU145 cells which represent castration-resistant prostate cancer are essential for choosing novel chemotherapeutic targets to treat advanced prostate cancer patients. A disintegrin and metalloprotease 17 (ADAM17), a transmembrane metalloprotease, is primary sheddase for multiple EGFR pro-ligands, including transforming growth factor-alpha (TGF-a), heparin-binding epidermal growth factor (HB-EGF), and amphiregulin [4–7]. ADAM17 is overexpressed in the breast, ovary, kidney, colon and pancreas cancer tissues and regulates important biological phenomena in cancers through EGFR/PI3K/ AKT pathway [8–14]. Thus, it has been reported that ADAM17 proteolytic shedding of EGFR-binding Ping Lin, Xicai Sun, and Tian Feng contributed equally to this study. P. Lin Á X. Sun Á T. Feng Á H. Zou Á Y. Jiang Á Z. Liu Á D. Zhao Á X. Yu (&) Department of Biochemistry and Molecular Biology, College of Basic Medical Science, Harbin Medical University, Harbin 150081, China e-mail: yxg301@yahoo.com.cn 123 Mol Cell Biochem (2012) 359:235–243 DOI 10.1007/s11010-011-1018-8