RNA helicase DHX15 decreases cell apoptosis by NF-κB signaling pathway in Burkitt lymphoma

Abstract

Abstract Background DHX15 is one of the RNA helicase family members involving in several biological processes. Studies have reported that overexpression of DHX15 is related to cancer progression. However, the role of DHX15 in Burkitt lymphoma (BL) and latent Epstein-Barr virus (EBV) infection remains to be elucidated. Methods Expression of DHX15 was measured in BL patient by immunohistochemical staining. In vitro study, a CCK-8 assay was used to analyze cell proliferation and flow cytometry was performed to assess cell cycle, apoptosis and mitochondria membrane potential. Members of NF-κB signaling pathway and apoptotic-related proteins expression were measured by western-blot. EBV latent infection products and RNA polymerase III transcripts expression were determined by quantitative real-time PCR and western-blot. In vivo study, HE, IHC, TUNEL and ISH assays were used to analyze the effect of DHX15 on subcutaneous tumor nodes formation. Results DHX15 was overexpressed in Burkitt lymphoma patients and tends to be associated with poor progression-free survival and poor overall survival. Knockdown of DHX15 significantly inhibited BL tumor growth, reduced cell proliferation, induced cell cycle arrest and increased cell apoptosis. Further analysis showed that canonical NF-κB signaling and its downstream targets, mitochondria and Caspase were involved in the increased cell apoptosis after DHX15 gene knockdown. Furthermore, knockdown of DHX15 reduced EBV latent infection products expression and inhibited RNA polymerase III activity. Conclusion DHX15 may be an oncogene in the development of BL and a potential therapeutic target for the treatment of BL and latent EBV infection.

Keywords

• DHX15
• Burkitt lymphoma
• Gene knockdown
• Apoptosis
• NF-κB signaling pathway