Li Pang1, Jian-Fang Li1, Liping Su1, Mingde Zang1, Zhiyuan Fan1, Beiqin Yu1, Xiongyan Wu1, Chen Li1, Min Yan1, Zheng-Gang Zhu1, Bingya Liu2. 1. Shanghai Key Laboratory of Gastric Neoplasms, Department of Surgery, Shanghai Institute of Digestive Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, People's Republic of China. 2. Shanghai Key Laboratory of Gastric Neoplasms, Department of Surgery, Shanghai Institute of Digestive Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, People's Republic of China. liubingya@sjtu.edu.cn.
Abstract
BACKGROUND: The ALEX is a novel member of the armadillo family and ALEX1 was reported to be reduced or even lost in multiple solid tumors. However, its expression profile and oncogenic role in gastric cancer (GC) remains largely unknown. METHODS: ALEX1 expression was detected in 161 GC samples by immunohistochemistry staining. NCI-N87 cells transfected by ALEX1 lentivirus vectors and MKN28 cells transfected by ALEX1 shRNA were used for biological function investigation. Western blot was applied to explore the molecular mechanism and pull-down assays were applied to measure the activity of Rho GTPases. In vivo tumorigenicity, peritoneal and lung metastasis experiments were performed by tumor cell engraftment into nude mice. Bisulfite genomic sequencing and methylation-specific PCR were applied to check the methylation status of the ALEX1 gene. RESULTS: The expression rate of ALEX1 was significantly reduced in gastric tumor samples compared to non-tumor samples (43.5 vs. 90.2%), and its expression was closely related to the tumor differentiation, TNM staging, and lymph nodes metastasis. ALEX1 overexpression in NCI-N87 cells significantly inhibited cell proliferation, migration, and invasion in vitro, and disrupted the structure of the cytoskeleton. ALEX1 overexpression attenuated xenografts growth, peritoneal, and lung metastasis in nude mice. Mechanistically, the overexpression of ALEX1 inhibits thrombin-induced metastasis and Rho GTPases activation. Bisulfite genomic sequencing and methylation-specific PCR revealed that the promoter of ALEX1 is highly methylated in GC cells and tissues. CONCLUSIONS: ALEX1 expression is reduced in GC and is involved in diverse cellular functions. ALEX1 inhibits metastasis through the PAR-1/Rho GTPase signaling pathway.
BACKGROUND: The ALEX is a novel member of the armadillo family and ALEX1 was reported to be reduced or even lost in multiple solid tumors. However, its expression profile and oncogenic role in gastric cancer (GC) remains largely unknown. METHODS:ALEX1 expression was detected in 161 GC samples by immunohistochemistry staining. NCI-N87 cells transfected by ALEX1 lentivirus vectors and MKN28 cells transfected by ALEX1 shRNA were used for biological function investigation. Western blot was applied to explore the molecular mechanism and pull-down assays were applied to measure the activity of Rho GTPases. In vivo tumorigenicity, peritoneal and lung metastasis experiments were performed by tumor cell engraftment into nude mice. Bisulfite genomic sequencing and methylation-specific PCR were applied to check the methylation status of the ALEX1 gene. RESULTS: The expression rate of ALEX1 was significantly reduced in gastric tumor samples compared to non-tumor samples (43.5 vs. 90.2%), and its expression was closely related to the tumor differentiation, TNM staging, and lymph nodes metastasis. ALEX1 overexpression in NCI-N87 cells significantly inhibited cell proliferation, migration, and invasion in vitro, and disrupted the structure of the cytoskeleton. ALEX1 overexpression attenuated xenografts growth, peritoneal, and lung metastasis in nude mice. Mechanistically, the overexpression of ALEX1 inhibits thrombin-induced metastasis and Rho GTPases activation. Bisulfite genomic sequencing and methylation-specific PCR revealed that the promoter of ALEX1 is highly methylated in GC cells and tissues. CONCLUSIONS:ALEX1 expression is reduced in GC and is involved in diverse cellular functions. ALEX1 inhibits metastasis through the PAR-1/Rho GTPase signaling pathway.
Authors: Christina Fitzmaurice; Daniel Dicker; Amanda Pain; Hannah Hamavid; Maziar Moradi-Lakeh; Michael F MacIntyre; Christine Allen; Gillian Hansen; Rachel Woodbrook; Charles Wolfe; Randah R Hamadeh; Ami Moore; Andrea Werdecker; Bradford D Gessner; Braden Te Ao; Brian McMahon; Chante Karimkhani; Chuanhua Yu; Graham S Cooke; David C Schwebel; David O Carpenter; David M Pereira; Denis Nash; Dhruv S Kazi; Diego De Leo; Dietrich Plass; Kingsley N Ukwaja; George D Thurston; Kim Yun Jin; Edgar P Simard; Edward Mills; Eun-Kee Park; Ferrán Catalá-López; Gabrielle deVeber; Carolyn Gotay; Gulfaraz Khan; H Dean Hosgood; Itamar S Santos; Janet L Leasher; Jasvinder Singh; James Leigh; Jost B Jonas; Jost Jonas; Juan Sanabria; Justin Beardsley; Kathryn H Jacobsen; Ken Takahashi; Richard C Franklin; Luca Ronfani; Marcella Montico; Luigi Naldi; Marcello Tonelli; Johanna Geleijnse; Max Petzold; Mark G Shrime; Mustafa Younis; Naohiro Yonemoto; Nicholas Breitborde; Paul Yip; Farshad Pourmalek; Paulo A Lotufo; Alireza Esteghamati; Graeme J Hankey; Raghib Ali; Raimundas Lunevicius; Reza Malekzadeh; Robert Dellavalle; Robert Weintraub; Robyn Lucas; Roderick Hay; David Rojas-Rueda; Ronny Westerman; Sadaf G Sepanlou; Sandra Nolte; Scott Patten; Scott Weichenthal; Semaw Ferede Abera; Seyed-Mohammad Fereshtehnejad; Ivy Shiue; Tim Driscoll; Tommi Vasankari; Ubai Alsharif; Vafa Rahimi-Movaghar; Vasiliy V Vlassov; W S Marcenes; Wubegzier Mekonnen; Yohannes Adama Melaku; Yuichiro Yano; Al Artaman; Ismael Campos; Jennifer MacLachlan; Ulrich Mueller; Daniel Kim; Matias Trillini; Babak Eshrati; Hywel C Williams; Kenji Shibuya; Rakhi Dandona; Kinnari Murthy; Benjamin Cowie; Azmeraw T Amare; Carl Abelardo Antonio; Carlos Castañeda-Orjuela; Coen H van Gool; Francesco Violante; In-Hwan Oh; Kedede Deribe; Kjetil Soreide; Luke Knibbs; Maia Kereselidze; Mark Green; Rosario Cardenas; Nobhojit Roy; Taavi Tillmann; Taavi Tillman; Yongmei Li; Hans Krueger; Lorenzo Monasta; Subhojit Dey; Sara Sheikhbahaei; Nima Hafezi-Nejad; G Anil Kumar; Chandrashekhar T Sreeramareddy; Lalit Dandona; Haidong Wang; Stein Emil Vollset; Ali Mokdad; Joshua A Salomon; Rafael Lozano; Theo Vos; Mohammad Forouzanfar; Alan Lopez; Christopher Murray; Mohsen Naghavi Journal: JAMA Oncol Date: 2015-07 Impact factor: 31.777