Aberrant Expression of β-Catenin Correlates with Infiltrating Immune Cells and Prognosis in NSCLC.

Aims: β-catenin is a critical regulating factor of the Wnt pathway, which is closely linked to tumorigenesis, tumor growth, metastasis, and tumor immunity. Our study focused on exploring the relationship between β-catenin and clinicopathological features, prognosis, as well as infiltrating immune cells and immune scores, so as to illustrate its clinical significance in NSCLC. Materials and Methods: The β-catenin mRNA (CTNNB1) and protein expression data were downloaded from the UALCAN and the UCSC Xena website, respectively. All tumor-immune infiltrating cells' data were downloaded from the TIMER platform and immune scores were downloaded from ESTIMATE website. The expression of β-catenin protein in our cohort was measured by immunohistochemistry. Results: β-catenin mRNA level was higher in lung adenocarcinoma (LUAD) compared to normal tissues (p < 0.001) and was related to overall survival (OS) (p < 0.001) and post-progression survival (PPS) (both p = 0.049) in LUAD. Aberrant β-catenin protein expression was higher in male and lung squamous cell carcinoma (LUSC) patients (both p = 0.001). Also, it was considered to be a prognosis factor independently (p = 0.034). In addition, β-catenin protein was negatively correlated with CD8⁺T cells (r = -0.128, p = 0.008), neutrophils (r = -0.198, p < 0.001), immune score (r = -0.109, p = 0.024), stromal score (r = -0.097, p = 0.045), and ESTIMATE score (r = -0.113, p = 0.020). Conclusions: Aberrant β-catenin protein expression was evidently higher in NSCLC and might serve as a biomarker for poor prognosis. Most importantly, β-catenin protein might play an important part in tumor immunity and the tumor microenvironment by inhibiting the infiltration of CD8+ T cells and neutrophils.