HnRNPR promotes non-small cell lung cancer progression by protecting XB130 mRNA from XRN1- and DIS3L2-mediated degradation

Abstract

The adaptor protein XB130 is critically implicated in tumorigenesis. However, the mechanisms regulating its expression in tumors are not well understood. Our previous studies have identified hnRNPR as a potential binding protein of XB130 3’UTR in non-small cell lung cancer (NSCLC). This study aimed to clarify hnRNPR's role in NSCLC progression and its specific mechanisms regulating XB130 expression. The expression of hnRNPR in NSCLC and normal tissues was assessed using NSCLC tissue microarray and the TCGA database. Subsequently, in vitro and in vivo experiments were conducted to investigate the impact of hnRNPR on NSCLC cell proliferation and epithelial-mesenchymal transition (EMT) by modulating XB130 expression. The underlying molecular mechanisms of hnRNPR regulating XB130 expression were explored utilizing a range of molecular biology techniques including Western blotting, Real-time quantitative PCR, Immunohistochemistry, Dual-luciferase reporter assay, RNA pull-down assay, and RNA immunoprecipitation. We identified the overexpression of hnRNPR in NSCLC, with heightened hnRNPR levels significantly associated with poor prognosis in patients with lung adenocarcinoma. Functionally, hnRNPR overexpression promoted NSCLC cell proliferation and EMT and activated the Akt signaling pathway. Mechanistically, hnRNPR protected XB130 mRNA from XRN1- and DIS3L2-mediated degradation by binding to specific regions within XB130 3’UTR, consequently elevating XB130 expression. Lastly, XB130 overexpression counteracted the effects of hnRNPR silencing on NSCLC cells. Overall, our study unveils the potential of targeting the hnRNPR/XB130 axis as a promising therapeutic strategy for NSCLC.