J Cancer 2021; 12(1):253-263. doi:10.7150/jca.49709

Research Paper

NKCC1 promotes proliferation, invasion and migration in human gastric cancer cells via activation of the MAPK-JNK/EMT signaling pathway

Jun-fu Wang#, Kun Zhao#, Ye-yang Chen, Yue Qiu, Jin-hui Zhu, Bo-pei Li, Zheng Wang, Jun-qiang Chen

Department of Gastrointestinal Surgery, The First Affiliated Hospital of Guangxi Medical University, 6 Shuangyong Road, Nanning 530021, Guangxi Zhuang Autonomous Region, China.
#These authors contributed equally to this work.

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Citation:
Wang Jf, Zhao K, Chen Yy, Qiu Y, Zhu Jh, Li Bp, Wang Z, Chen Jq. NKCC1 promotes proliferation, invasion and migration in human gastric cancer cells via activation of the MAPK-JNK/EMT signaling pathway. J Cancer 2021; 12(1):253-263. doi:10.7150/jca.49709. Available from https://www.jcancer.org/v12p0253.htm

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Abstract

Aims: This study aimed to explore the function of NKCC1 in the proliferation, migration and invasion of Gastric cancer (GC) cells.

Materials and Methods: GC data extracted from the database was analyzed using molecular bioinformatics. The expression levels of NKCC1 in tissue samples from GC patients and GC cell lines were determined by Western blotting, qRT-PCR, and immunohistochemistry. Immunofluorescence was used to detect protein localization. The GC cell lines were transfected with NKCC1-shRNA or expression plasmid, and in vitro proliferation, invasion and migration were analyzed by the CCK8, wound healing and transwell tests.

Results: The NKCC1 mRNA level was significantly increased in GC tissues than that in normal gastric tissues (P = 0.0195). This phenomenon was further confirmed by the analysis of the TCGA-GTEx database that includes 408 gastric cancer tissues and 211 normal gastric tissues (P < 0.01). Furthermore, the increased level of NKCC1 was significantly correlated with Tumor size (P = 0.039), lymphatic node metastasis (P = 0.035) and tumor stage (P = 0.034). In vitro experiments confirmed that NKCC1 expression was higher in GC cells compared to that in GES-1 cells, and was mainly localized to the cytoplasm and membrane. NKCC1 silencing inhibited GC cell proliferation, invasion, migration and EMT, whereas its overexpression had the opposite effects. Furthermore, NKCC1 overexpression upregulated and activated JNK, and the targeted inhibition of JNK by SP600125 abrogated the pro-metastatic effects of NKCC1.

Conclusions: NKCC1 promotes migration and invasion of GC cells by MAPK-JNK/EMT pathway and can be a potential therapeutic target.

Keywords: Na+/K+/2CI- cotransporter 1 (NKCC1), gastric cancer, migration, invasion, epithelial-mesenchymal transition