CBX4 contributes to radioresistance by regulating autophagic activity in esophageal squamous cell carcinoma

• Published in: Annals of translational medicine 2022-09, Vol.10 (18), p.959-959
• Main Authors: Zhu, Hongcheng, Chen, Hui, Chen, Guangzong, Liu, Ming, Chu, Li, Gu, Yu, Chen, Yun, Zhang, Chi, Qin, Qin, Chen, Yanan, Chen, Weiwei, Fan, Jianhong, Nie, Yongzhan, Chen, Junqiang, Wu, Shixiu, Sun, Xinchen, Zhao, Weixin, Zhao, Kuaile
• Format: Article
• Language: English
• Subjects: Original
• ISSN: 2305-5839; 2305-5839
• DOI: 10.21037/atm-21-3630

BackgroundThe function of Chromobox 4 (CBX4) function has attracted attention in many cancer types due to its unique biological role; however, its mechanism in esophageal squamous cell carcinoma (ESCC) under radiotherapeutic treatment has not yet been investigated. MethodsSilencing of CBX4 was carried out in TE-13 and KYSE-150 cell lines. Cell proliferation, radiosensitivity, DNA damage, apoptosis, and cell cycle distribution were determined by Cell Counting Kit-8 (CCK-8), colony formation assay, immunofluorescence, flow cytometry, and immunoblot in vitro. In vivo xenograft models were also used to assess tumor cell growth and radioresistance. The underpinning mechanisms were explored based on pathway analysis and confirmed by rescue experiments, detecting cellular autophagy. ResultsKnockdown of CBX4 resulted in reduced tumor growth and enhanced radio-response in vivo and in vitro. Down-regulating CBX4 increased DNA damage, apoptotic rate, and G2/M arrest induced by radiation in ESCC cell lines. Gene Set Enrichment Analysis (GSEA) revealed that CBX4 was associated with cellular autophagy regulation. Enhanced radiosensitivity in ESCC cells silenced for CBX4 was partially blocked by autophagy inhibition (P