Tumor and Stem Cell Biology Androgen-Induced TMPRSS2 Activates Matriptase and Promotes Extracellular Matrix Degradation, Prostate Cancer Cell Invasion, Tumor Growth, and Metastasis Chun-Jung Ko 1 , Cheng-Chung Huang 1 , Hsin-Ying Lin 1 , Chun-Pai Juan 1 , Shao-Wei Lan 1 , Hsin-Yi Shyu 1,2 , Shang-Ru Wu 1 , Pei-Wen Hsiao 3 , Hsiang-Po Huang 4 , Chia-Tung Shun 5 , and Ming-Shyue Lee 1 Abstract Dysregulation of androgen signaling and pericellular prote- olysis is necessary for prostate cancer progression, but the links between them are still obscure. In this study, we show how the membrane-anchored serine protease TMPRSS2 stimulates a proteolytic cascade that mediates androgen-induced prostate cancer cell invasion, tumor growth, and metastasis. We found that matriptase serves as a substrate for TMPRSS2 in mediating this proinvasive action of androgens in prostate cancer. Further, we determined that higher levels of TMPRSS2 expression cor- relate with higher levels of matriptase activation in prostate cancer tissues. Lastly, we found that the ability of TMPRSS2 to promote prostate cancer tumor growth and metastasis was associated with increased matriptase activation and enhanced degradation of extracellular matrix nidogen-1 and laminin b1 in tumor xenografts. In summary, our results establish that TMPRSS2 promotes the growth, invasion, and metastasis of prostate cancer cells via matriptase activation and extracellular matrix disruption, with implications to target these two pro- teases as a strategy to treat prostate cancer. Cancer Res; 75(14); 2949–60. Ó2015 AACR. Introduction Prostate cancer is the most frequent male malignancy and a leading cause of cancer-related death in many Western countries (1). In prostate cancer, androgen signaling generally regulates the expression of genes associated with cancer cell growth and sur- vival (2). Because androgen signaling has been shown to be involved in prostate cancer development and progression (3), androgen deprivation therapy is an option for the patients. Initially, most prostate cancer cells respond to this therapy, but eventually tumors relapse and take on a castration therapy– resistant prostate cancer phenotype that correlates with poor prognosis and high metastatic potential (4). Moreover, androgen signaling has been shown to be involved in prostate cancer cell invasion (5, 6) and strongly implicated in metastasis (3). How- ever, the detailed molecular mechanisms through which andro- gen signaling can induce prostate cancer cell invasion and metas- tasis still need more investigation. Deregulation of pericellular proteolysis has been proposed to be involved in cancer progression because of its role in the degradation of the extracellular matrix (ECM) and the alteration of the micro- environment (7). Recently, several lines of evidence have shown that dysregulation of some membrane-anchored serine proteases (MASP) contributes to the progression of many human disorders, including tumor growth, invasion, and metastasis (8). Among them, matriptase has been focused on because it plays crucial roles in carcinogenesis and cancer cell invasion including prostate cancer (9–12). In prostate cancer cells, androgens can induce matriptase activation and shedding (13). However, the molecular mechanism through which androgens induce matriptase activation and wheth- er the androgen-induced proteolytic cascade plays a role in prostate cancer progression and metastasis are still unknown. TMPRSS2 is a member of the MASP family (14) and predom- inantly expressed in prostate (15). Recent studies have indicated that a gene fusion of the 5 0 untranslational region of TMPRSS2 to E26 transformation-specific (ETS) transcription factors (ERG and ETV1) is often observed in prostate cancer tissues (16). In addi- tion, TMPRSS2 protein level has been shown to be correlated with prostate cancer progression (17, 18). However, the in vivo sub- strates of TMPRSS2 and the TMPRSS2-initiated proteolytic cas- cade are unknown, and the exact role of TMPRSS2 in prostate cancer progression is still unclear. In this report, we addressed the functional role of TMPRSS2 in androgen-induced prostate cancer cell invasion, tumor growth, and metastasis and identified the 1 Department of Biochemistry and Molecular Biology, College of Med- icine, National Taiwan University,Taipei,Taiwan. 2 Bureau of Investiga- tion, Ministry of Justice, College of Medicine, National Taiwan Univer- sity,Taipei,Taiwan. 3 Agricultural Biotechnology Research Center, Aca- demia Sinica, Taipei,Taiwan. 4 Graduate Institute of Medical Genomics and Proteomics, College of Medicine, National Taiwan University, Taipei, Taiwan. 5 Department and Graduate Institute of Forensic Med- icine, College of Medicine, National Taiwan University,Taipei,Taiwan. Note: Supplementary data for this article are available at Cancer Research Online (http://cancerres.aacrjournals.org/). Corresponding Author: Ming-Shyue Lee, Department of Biochemistry and Molecular Biology, College of Medicine, National Taiwan University, R817, 8F, No. 1, Section 1, Jen-Ai Rd. Taipei, Taiwan. Phone. 011-886-2-2395-7966, Fax: 011- 886-2-2391-5295; E-mail: mslee2006@ntu.edu.tw doi: 10.1158/0008-5472.CAN-14-3297 Ó2015 American Association for Cancer Research. Cancer Research www.aacrjournals.org 2949 on July 15, 2015. © 2015 American Association for Cancer Research. cancerres.aacrjournals.org Downloaded from Published OnlineFirst May 27, 2015; DOI: 10.1158/0008-5472.CAN-14-3297