Protocadherin 10 inhibits cell proliferation and induces apoptosis via regulation of DEP domain containing 1 in endometrial endometrioid carcinoma Yihua Yang a, ⁎ ,1 , Yan Jiang b,1 , Man Jiang b , Jiamiao Zhang a , Bing Yang b , Yuanping She b , Wanxue Wang a , Yan Deng c , Yuan Ye b, ⁎⁎ a Reproductive Medicine Center of the Affiliated Hospital, Guilin Medical University, Guilin, Guangxi, China b Department of Obstetrics and Gynecology of the Affiliated Hospital, Guilin Medical University, Guilin, Guangxi, China c Department of Obstetrics and Gynecology, The Chinese University of Hong Kong, Shatin, N. T., Hong Kong Special Administrative Region abstract article info Article history: Received 15 December 2015 and in revised form 27 February 2016 Accepted 7 March 2016 Available online 10 March 2016 Endometrial cancer is the most common gynecologic malignancy and about 80% of these cancers are endometrial endometrioid carcinoma (EEC). Previously, we have demonstrated that protocadherin 10 (PCDH10) is a tumor suppressor gene in EEC, and in this study we further explored the molecular mechanisms of PCDH10 in EEC. We first detect the PCDH10 expression in EEC tissues and then investigate the mechanism in two EEC cell lines. The mRNA and protein expression levels were measured by quantitative real time PCR (qRT-PCR) and western blot, respectively; Cell growth was determined by MTS, CCK-8 and colony formation assays; Cell cycle was determined by flow cytometry, and cell apoptosis was examined by flow cytometry and TUNEL assay. The downstream mediator of PCHD10 was confirmed by Topflash luciferase reporter assay. QRT-PCR and western blot results showed that PCDH10 was down-regulated in EEC clinical tissues. Restoration of PCDH10 suppressed cell growth and induced apoptosis in EEC cells. Dishevelled, EGL-10 and Pleckstrin domain containing 1 (DEPDC1) was a potential downstream mediator of PCDH10 as revealed by RNA-sequencing, and mechanistic studies suggested that DEPDC1 is a downstream mediator and promotes cell growth and induces apoptosis in EEC cells. Western blot further showed that PCDH10 restoration activate apoptotic signaling pathway via caspase signaling in both EEC cell lines and EEC clinical tissues. Collectively, our results suggest that PCDH10-DEPDC1- caspase signaling may be a novel regulatory axis in EEC development and it will be of great interest to explore the clinical significance of PCDH10 and DEPDC1 in the future. © 2016 Elsevier Inc. All rights reserved. Keywords: EEC PCDH10 DEPDC1 Cell growth Apoptosis Caspase 1. Introduction Endometrial cancer is the most common gynecologic malignancy and ranks fourth in whole malignancies among women (Siegel et al., 2013). Endometrioid endometrial carcinoma (EEC), accounting for about 80% of the whole cases, and is often associated with obesity, estro- gen stimulation, hormone receptor positivity, and favorable prognosis (Di Cristofano and Ellenson, 2007). Several critical genes have been established to play an essential role in EEC progression, but the underly- ing molecular mechanisms involving oncogenic or tumor suppressive factors are largely unknown (Kandoth et al., 2013; Matias-Guiu and Prat, 2013; Yang et al., 2013). Our group has demonstrated that Ying Yang 1 plays an important role in EEC development (Yang et al., 2013), and recently, we also discovered that Protocadherin 10 (PCDH10) played a tumor suppressive role in EEC (Zhao et al., 2014). PCDH10 is a member of nonclustered protocadherin subfamily and has been demonstrated as a tumor suppressor in multiple cancers (Kim et al., 2011; Wolverton and Lalande, 2001; Ying et al., 2006). Pre- viously, our group has demonstrated that PCDH10 is silenced in EEC cells/tumors through its promoter CpG hypermethylation, and more importantly we also uncovered a novel PCDH10-Wnt/β-catenin- MALAT1 regulatory axis that contributes to EEC development and pro- gression (Zhao et al., 2014). Based on the RNA-sequencing analysis in our previous study, many genes have been shown to be potential downstream mediators of PCDH10. Among these genes, Dishevelled, EGL-10 and Pleckstrin do- main containing 1 (DEPDC1) is highly conserved in many species, and DEP domain have been reported to regulate a wide range of cellular functions including a large number of signaling proteins (Kharrat Experimental and Molecular Pathology 100 (2016) 344–352 ⁎ Correspondence to: Y. Yang, Reproductive Medicine Center of the Affiliated Hospital, Guilin Medical University, Guilin, Guangxi 541001, China. ⁎⁎ Correspondence to: Y. Ye, Department of Obstetrics and Gynecology of the Affiliated Hospital, Guilin Medical University, Guilin, Guangxi 541001, China. E-mail addresses: yangyihua@glmc.edu.cn (Y. Yang), 260070985@qq.com (Y. Jiang), jiangmanman@126.com (M. Jiang), zhangxq1006@163.com (J. Zhang), 1224462833@qq.com (B. Yang), shelittle@163.com (Y. She), 854777399@qq.com (W. Wang), shrilly@cuhk.edu.hk (Y. Deng), glyy169@163.com (Y. Ye). 1 Both authors contributed equally to this article. http://dx.doi.org/10.1016/j.yexmp.2016.03.002 0014-4800/© 2016 Elsevier Inc. All rights reserved. Contents lists available at ScienceDirect Experimental and Molecular Pathology journal homepage: www.elsevier.com/locate/yexmp