NOVA1 promotes NSCLC proliferation and invasion by activating Wnt/β-catenin signaling

Abstract

Background: Neuro-oncological ventral antigen 1 (NOVA1) is a neuron-specific RNA-binding protein which regulates alternative splicing in the developing nervous system. Recent research has found that NOVA1 plays a significant role in carcinogenesis. In this paper, we examine the role of NOVA1 in non-small cell lung cancer (NSCLC) and its underlying molecular mechanisms. Methods: The expression of NOVA1 in NSCLC was detected by immunohistochemistry and correlations between NOVA1 expression and clinicopathological factors were analyzed by chi–square tests. Kaplan–Meier survival analysis and the Cox regression model were used to evaluate the predictive effect of prognostic factors. Western blotting, Cell Counting Kit-8, colony formation, apoptosis, migration and invasion assays were used to detect the effects of silencing (si)NOVA1 RNA on Wnt/β-catenin signaling and biological behavior in NSCLC cell lines. Results: Our study showed that expression of NOVA1 was up-regulated and significantly correlated with poor differentiation (p = 0.020), advanced TNM stage (P = 0.001), T stage (P = 0.001) and lymph node metastasis (P = 0.000) as well as the expression of β-catenin (P = 0.012) in NSCLC. The down-regulation of NSCLC by siRNA significantly inhibited proliferation, migration and invasion and promoted apoptosis in NSCLC cells. Expression of Wnt signaling molecules, including β-catenin, activated β-catenin, cyclin D1, matrix metalloproteinase (MMP)-2 and MMP-7, was also significantly reduced by siNOVA1. The inhibition of Wnt/β-catenin signaling in A549 and H1299 cells by siNOVA1 was reversed after treatment with a β-catenin expression plasmid. Conclusion: The present study suggests that NOVA1 may serve as a potential prognosis biomarker in NSCLC. High NOVA1 expression was associated with poor survival rate. Finally, in vitro experiments verified that NOVA1 promotes NSCLC cell proliferation and invasion by regulating Wnt/β-catenin signaling.