Zhang, Lijuan, Li, Shuping, Wang, Rong, Chen, Changyuan, Ma, Wen, and Cai, Hongyi
Large tumor suppressor 2 (LATS2), an important mediator of the cell apoptotic response pathway, has been linked to the progression of several cancers. Here, we described the molecular feature of LATS2 as a novel antitumor factor in liver cancer cells in vitro. Western blotting was used to detect the expression of LATS2 and its downstream factors. ELISA, immunofluorescence, and flow cytometry were used to evaluate the alterations of mitochondrial function in response to LATS2 overexpression. Adenovirus-loaded LATS2 and siRNA against DRP1 were transfected into liver cancer cells to overexpress LATS2 and knockdown DRP1 expression, respectively. The results of the present study demonstrated that overexpression of LATS2 was closely associated with more liver cancer cell death. Mechanistically, LATS2 overexpression increased the expression of DRP1, and DRP1 elevated mitochondrial division, an effect that was accompanied by mitochondrial dysfunction, including mitochondrial membrane potential reduction, mitochondrial respiratory complex downregulation, mitochondrial cyt-c release into the nucleus and mitochondrial oxidative injury. Moreover, LATS2 overexpression also initiated mitochondrial apoptosis, and this process was highly dependent on DRP1-related mitochondrial division. Molecular investigations demonstrated that LATS2 modulated DRP1 expression via the Wnt/β-catenin pathway. Inhibition of the Wnt/β-catenin pathway pregented LATS2-mediated DRP1 upregulation, ultimately sustaining mitochondrial function and cell viability in the presence of LATS2 overexpression. Altogether, the above data identify LATS2-Wnt/β-catenin/DRP1/mitochondrial division as a novel anticancer signaling pathway promoting cancer cell death, which might be an attractive therapeutic target for the treatment of hepatocellular carcinoma. [ABSTRACT FROM AUTHOR]