Alpha Protein Kinase 2 Promotes Esophageal Cancer via Integrin Alpha 11.

Background: As a common disease around the world, esophageal cancer (EC) primarily includes two subclasses: esophageal adenocarcinoma and esophageal squamous cell carcinoma. Mortality has been rising over the years; hence, exploring the mechanism of EC development has become critical. Among the alpha protein kinases, alpha protein kinase 2 (ALPK2) presumably has a connection with EC, but it has never been revealed before. Methods: In this study, IHC analysis was used for ALPK2 expression quantification in ES tissues. TE-1 and Eca-109, which are both human EC cell lines, were used for in vitro analysis of cell proliferation, migration, apoptosis, and colony formation. Results: ALPK2 was found to have an abundant expression within EC tissues (P < 0.001), as well as in the two selected human EC cell lines (P < 0.05). The data showed that ALPK2 depletion suppressed EC cell proliferation, migration, and colony formation, meanwhile stimulating apoptosis (P < 0.001). The in vivo experiments also displayed inhibitory effects caused by ALPK2 depletion on EC tumorigenesis (P < 0.001). It was further validated that ALPK2 depletion made the phosphorylation of Akt and mTOR, as well as CDK6 and PIK3CA levels downregulated (P < 0.001). Mechanistically, we identified integrin alpha 11 (ITGA11) as a downstream gene of ALPK2 regulating EC. More importantly, we found that ITGA11 elevation promoted cell proliferation and migration and rescued the suppression effects caused by ALPK2 depletion (P < 0.001). Conclusions: ALPK2 promotes esophageal cancer via integrin its downstream gene alpha 11; ALPK2 can potentially act as a target for the treatment of EC.

Human papillomavirus promotes esophageal squamous cell carcinoma by regulating DNA methylation and expression of HLA-DQB1.

AIMS: Esophageal cancer (EC) is one of the most prevalent and deadly cancers worldwide. Along with nutrition, smoking and alcohol consumption, human papillomavirus (HPV) infection is one of the major risk factors, which is modulated by host immune response. This study is aimed at elucidating how HPV modifies host immune system in the EC pathogenesis. METHODS: The HPV and HLA-DQB1 levels in primary esophageal squamous cell (ESC) cancer cells from Han, Khazak and Uygur patients were analyzed by quantitative real-time PCR and immunoblotting. The ability of HPV16 E6/E7 to transform normal primary ESCs was investigated by infecting ESC with pMSCVpuro-carried E6 or E7. The shRNA against HPV16 E6 or E7 was delivered by adenovirus into esophageal squamous cell carcinoma (ESCC) cells with high HPV content. The DNA methylation level of HLA-DQB1 was measured by methylation-specific PCR. RESULTS: The HLA-DQB1 expression level was correlated with the levels of HPV and inversely related to DNA methylation level of HLA-DQB1. Overexpressing HPV16 E6 or E7 alone was enough to transform normal primary ESCs. However, single knockdown of either E6 or E7 in ESC cancer cells did not reduce HLA-DQB1 expression. CONCLUSIONS: Oncogenic HPV E6 and E7 genes promoted ESCC pathogenesis by upregulating susceptible HLA-DQB1 via DNA demethylation.