Regulatory Effects and Mechanism of Immune Inhibitory Receptor LAIR-1 in Non-small Cell Lung Cancer

Purpose: To investigate the association of leukocyte-associated immunoglobulin-like receptor 1 (LAIR-1) levels with clinicopathological features and prognosis of non-small cell lung cancer (NSCLC). Methods: The expression of LAIR-1 and clinicopathological data were downloaded from The Cancer Genome Atlas database and Gene Expression Omnibus for analyzing the correlation between LAIR-1 expression and prognosis. Tissue samples from 118 NSCLC patients and 47 paired adjacent cancer tissues were collected and the expression of LAIR-1 in NSCLC tissues was detected by immunohistochemistry. The statistical analysis was performed for association analysis of LAIR-1 expression and clinicopathological properties. Lentiviral transfection of NSCLC cell lines A549 and SK-MES-1 for overexpressing LAIR-1 were used to evaluate the role of LAIR-1 in regulating cell cycle and apoptosis in NSCLC cell lines by flow cytometry. Results: LAIR-1 expression was lower in NSCLC tissues than in para-cancerous tumor tissues, and overall survival time was lower in the LAIR-1 low- expression group. Univariate analysis revealed that the low expression of LAIR-1 was related to lymph node metastasis, tumor stage, etc. in NSCLC patients. The LAIR-1 low-expression group of the NSCLC patients showed higher mortality, tumor progression, and lower overall survival and disease-free survival. Multivariate analyses demonstrated that the expression of LAIR-1 in squamous carcinoma patients had a negative correlation with NSCLC progression. In vitro experiments showed that the overexpression of LAIR-1 blocked the squamous cell carcinoma at the G1 stage and promoted cell apoptosis. Conclusion: LAIR-1 was closely associated with lymph node metastasis, tumor stage, and patients’ prognosis.