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

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.