Exosome Releasing HSPD1 Assists HNF1A in Regulating the Invasion Ability and Radiosensitivity of Esophageal Squamous Cell Carcinoma Cells via Activating EMT

Abstract Background: Concurrent chemoradiotherapy is the standard scheme for locally advanced non-surgical esophageal squamous cell carcinoma (ESCC). But there are frequently different results due to tumor heterogeneity. HNF1A and HSPD1 have been shown to be associated with the invasion, proliferation, apoptosis, and chemical resistance in multiple cancers. The aim of this study was to investigate the effects of HNF1A and HSPD1 on invasion and radiosensitivity of ESCC.Methods: HNF1A was overexpressed by lentivirus transfection and HSPD1 was silenced by knockdown plasmid in TE1 and KYSE150 cells. The mRNA expression of HSPD1 and HNF1A were detected by RT-qPCR. The correlated proteins expression was verified by western blot, and transwell tested the invasion ability of ESCC cells. Survival curve was plotted by colony formation assay. Co-immunoprecipitation and immunofluorescence assays were used to detect interaction and subcellular location of HNF1A and HSPD1. At the same time, we explored the change of HSPD1 protein in exosomes by western blotting.Results: Immunoprecipitation and mass spectrometry identified the combination of HNF1A and HSPD1/hnRNPA1/A3/TCP1 in TE1 cells. Co-immunoprecipitation and immunofluorescence experiments were verified the bind of HNF1A and HSPD1 again, but HNF1A did not regulate HSPD1 expression. Subsequently, HSPD1 knockout reversed HNF1A to promote invasion ability of cells by inhibiting EMT. Likewise, deletion of HSPD1 relieved radio-resistance from overexpression of HNF1A in TE1 and KYSE150 cells. Notably, induced cells to release abundant of HSPD1 through exosome, and ectopic expression of HNF1A prevented radiation-induced exosomal releasing of HSPD1.Conclusions: We initially demonstrated that HNF1A was assisted by HSPD1 to drive EMT process and promote invasion of ESCC cells, and explained that HNF1A prevented HSPD1 from releasing to extracellular with exosomes after irradiation, thereby causing radio-resistance. These findings provided theoretical basis of gene target treatment for radiotherapy of ESCC.