The promoting effects of GPR176 expression on proliferation, chemoresistance, lipogenesis and invasion of oesophageal cancer

PURPOSE: As a member of the G-protein-coupled receptor 1 family, the G-protein-coupled receptor 176 (GPR176) gene encodes a glycosylated protein made up of 515 amino acids. The current study was performed to evaluate the impact of GPR176 on the clinicopathology and prognosis of oesophageal cancer, as well as uncover its molecular mechanisms. METHODS: Bioinformatics and clinical tissue samples were used to detect the expression and clinicopathological significance of GPR176 in oesophageal cancer. The expression, proliferation, migration and invasion, apoptosis and lipid droplet formation of GPR176 gene in oesophageal cancer were performed as phenotypic readouts. RESULTS: Here, RT-PCR and bioinformatic analyses revealed that GPR176 mRNA expression was significantly higher in oesophageal cancer than in normal mucosa (p < 0.05). GPR176 mRNA expression was associated with low weight and BMI, low T stage, low N and clinicopathological stage, low histological grade and favourable clinical outcome of oesophageal cancer (p < 0.05). The differential genes of GPR176 mRNA were involved in protein digestion and absorption, extracellular matrix constituent, endoplasmic reticulum lumen, among others (p < 0.05). GPR176-related genes were classified as being involved in oxidoreductase activity, actin and myosin complexes, lipid localisation and transport, among others (p < 0.05). GPR176 knockdown suppressed proliferation, anti-apoptotic and anti-pyroptotic properties, migration, invasion, chemoresistance and lipid droplet formation in oesophageal cancer cells (p < 0.05), while ACC1 and ACLY overexpression reversed the inhibitory effects of GPR176 silencing on lipid droplet formation and chemoresistance. CONCLUSION: These findings indicated that upregulated expression of GPR176 might be involved in oesophageal carcinogenesis and subsequent progression, aggressiveness, and induced chemoresistance by ACC1- and ACLY-mediated lipogenesis and lipid droplet assembly.