ATP6V0D2, a subunit associated with proton transport, serves an oncogenic role in esophagus cancer and is correlated with epithelial–mesenchymal transition

Background The poor prognosis of esophagus cancer (EC) is mainly due to its high invasiveness and metastasis, so it is urgent to search effectively prognostic markers and explore their roles in the mechanism of metastasis. Materials and methods Based on the TCGA database, we downloaded the RNA-Seq for analyzing the expression of ATP6V0D2. QRT-PCR was used to test the mRNA levels of ATP6V0D2 in cell lines. Chi-square tests were used to evaluate the correlation between ATP6V0D2 and clinical characteristics. Prognostic values were determined by Kaplan–Meier methods and cox’s regression models. CCK-8 and clone formation assays were employed to evaluate the cell viability, and Transwell assay was implemented to determine the invasive and migratory abilities. Correlations between ATP6V0D2 and motion-related markers were analyzed by the GEPIA database and confirmed by western blot. Moreover, the relationship between ATP6V0D2 and molecules related to cell cycle and apoptosis was also determined by western blot. Results A significant increase was observed in 3 EC-related cell lines compared to the normal cell line. ATP6V0D2 has a connection with the poor prognosis and can be considered as an independent prognosticator for patients with EC. Besides, ATP6V0D2 can improve cells viability as well as invasive and migratory abilities. What’s more, downregulation of ATP6V0D2 notably enhanced E -cadherin expression, while decreased N -cadherin, Vimentin, and MMP9 expression, whereas overexpression of ATP6V0D2 presented the opposite outcomes. Furthermore, we found that silencing ATP6V0D2 led to a significant reduction on the protein expression of Cyclin D1, CDK4, Bcl-2, whereas resulted in a notable enhancement on the Bax level. Conclusion ATP6V0D2 might be an independent prognosticator for EC patients, and it possibly promotes tumorigenesis by regulating epithelial–mesenchymal transition, cell cycle and apoptosis-related markers, providing the possibility that ATP6V0D2 may be a novel biomarker for the therapeutic intervention of EC.