Abstract 8P
Background
Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related death worldwide, and identification of novel targets is necessary for its diagnosis and treatment. This study aimed to investigate the biological function and clinical significance of tweety homolog 3 (TTYH3) in HCC.
Methods
The biological function of TTYH3 was investigated in vitro and in vivo through its overexpression and knockdown in HCC cell lines. The molecular mechanism by which TTYH3 regulates HCC cell invasion and metastasis was explored. The expression and clinical significance of TTYH3 was analyzed in HCC tissues. DNA methylation in TTYH3 was studied through microarray and pyrosequencing. The interaction between TTYH3 and MK5 was identified through co-immunoprecipitation assays and protein docking. In clinical HCC samples, TTYH3 expression was analyzed and the relation between TTYH3 expression and patient survival was also analyzed.
Results
TTYH3 overexpression promoted cell proliferation, migration, and invasion and inhibited HCCM3 and Hep3B cell apoptosis. TTYH3 promoted tumor formation and metastasis in vivo. TTYH3 upregulated calcium influx and intracellular chloride concentration, thereby promoting cellular migration and regulating epithelial-mesenchymal transition-related protein expression. The interaction between TTYH3 and MK5 was identified through co-immunoprecipitation assays and protein docking. TTYH3 promoted the expression of MK5, which then activated the GSK3β/β-catenin signaling pathway. MK5 knockdown attenuated the activation of GSK3β/β-catenin signaling by TTYH3. Based on site-mutant TTYH3, the results shown that TTYH3 expression was regulated in a positive feedback manner. In clinical HCC samples, TTYH3 was upregulated in the HCC tissues compared to nontumor tissues. Furthermore, high TTYH3 expression was significantly correlated with poor patient survival. The CpG islands were hypomethylated in the promoter region of TTYH3 in HCC tissues.
Conclusions
We identified TTYH3 regulates tumor development and progression via MK5/GSK3-β/β-catenin signaling in HCC and promotes itself expression in a positive feedback loop.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Department of Hepatobiliary and Pancreatic Surgery, The Affiliated Hospital of Qingdao University.
Funding
The National Natural Science Foundation of China (grant number 81600490), the Taishan Scholars Program of Shandong Province (grant number 2019010668), the Shandong Higher Education Young Science and Technology Support Program (grant number 2020KJL005), and National Natural Science Foundation of Shandong Province (grant number ZR2021MH171).
Disclosure
All authors have declared no conflicts of interest.