TRPM8 Inhibition Regulates the Proliferation, Migration and ROS Metabolism of Bladder Cancer Cells

Gang Wang,1– 4,* Rui Cao,5,* Kaiyu Qian,1– 4,* Tianchen Peng,6 Lushun Yuan,6 Liang Chen,6 Songtao Cheng,6 Yaoyi Xiong,6 Lingao Ju,1– 4 Xinghuan Wang,6 Yu Xiao1– 4,6 1Department of Biological Repositories, Zhongnan Hospital of Wuhan University, Wuhan, People’s Republic of China; 2Human Genetics Resource Preservation Center of Wuhan University, Wuhan, People’s Republic of China; 3Human Genetics Resource Preservation Center of Hubei Province, Wuhan, People’s Republic of China; 4Cancer Precision Diagnosis and Treatment and Translational Medicine Hubei Engineering Research Center, Wuhan, People’s Republic of China; 5Department of Urology, Beijing Friendship Hospital, Capital Medical University, Beijing, People’s Republic of China; 6Department of Urology, Zhongnan Hospital of Wuhan University, Wuhan, People’s Republic of China*These authors contributed equally to this workCorrespondence: Yu Xiao; Xinghuan Wang Tel +86-27-6781-2689; +86-27-6781-3104Fax +86-27-6781-2892Email yu.xiao@whu.edu.cn; wangxinghuan@whu.edu.cnIntroduction: Based on accumulating evidence, transient receptor potential (TRP) ion channels may play important roles in the occurrence and the progression of cancer. TRP melastatin 8 (TRPM8), a member of the TRP family, functions as a Ca2+-permeable channel and regulates various physiological and pathological processes. However, the effects of TRPM8 on bladder cancer (BCa) and its underlying mechanisms have not been elucidated.Methods: BCa tissues and matched noncancerous tissues were collected to examine the expression of the TRPM8 mRNA and protein using qRT-PCR, Western blotting and immunofluorescence staining. Meanwhile, the effect of knockdown or inhibition of the activity of the TRPM8 protein on the proliferation, migration and ROS metabolism of bladder cancer cells was detected using the MTT assay, clonogenic survival assay, Transwell chamber migration assay, and reactive oxygen species (ROS) detection, respectively. Furthermore, a mouse model transplanted with BCa cells was established to assess tumor growth after TRPM8 expression was inhibited in vivo.Results: Compared with the noncancerous tissues, the levels of TRPM8 in BCa tissues were significantly increased. Knockdown or inhibition of the activity of the TRPM8 protein in BCa cells reduced cell proliferation and migration. Moreover, the production of ROS was increased in cells treated with siTRPM8, which was accompanied by increased levels of Catalase, HO-1 and SOD2. Furthermore, a mouse model transplanted with the stable TRPM8-deficient T24 cell line was established, demonstrating that knockdown of TRPM8 delayed tumor growth in vivo.Discussion: TRPM8 might play an essential for BCa tumor progression and metastasis by interfering with BCa cell proliferation, motility, ROS metabolism and migration.Keywords: bladder cancer, TRPM8, proliferation, migration, reactive oxygen species