Bioinformatics analysis of LINC00426 expression in lung cancer and its correlation with patients' prognosis

BACKGROUND: To investigate the expression of long noncoding RNA (lncRNA) LINC00426 (long intergenic nonprotein coding RNA 426) in non-small cell lung cancer (NSCLC) patients and its correlation with their prognosis. METHODS: The expression of long noncoding RNA LINC00426 of non-small cell lung cancer (NSCLC) in The Cancer Genome Atlas (TCGA) database was screened. According to the expression level of LINC00426 in tumor tissue of NSCLC patients, the patients were divided into high and low LINC00426 expression groups. The correlation between LINC00426 expression group and the prognosis of the patient was analyzed by log-rank test. A total of 72 NSCLC patients who had undergone surgery were retrospectively included in this study. LINC00426 relative expression of tumor and normal lung tissue of the included 72 NSCLC patients were examined by real-time quantitative PCR assay. The correlation between LINC00426 expression and the patients' clinical characteristics were also evaluated. RESULTS: LINC00426 relative expression was not statistically different between cancer and normal tissue (P > 0.05) of NSCLC patients in the TCGA database. The amplification and deep deletion mutation of LINC00426 gene was found in 0.5% of NSCLC patients. The overall survival (OS) of the LINC00426 high expression group was significantly higher than that of the low expression group (HR = 0.81, P = 0.044), while there was no significant difference between the high and low expression group (HR = 0.97, P = 0.82) for disease-free survival (DFS). LINC0042646 expression level was elevated in 46 cases in normal lung tissue compared to the tumor tissue of the 72 NSCLC patients. LINC0042646 expression level was significantly correlated with the clinical stage (P < 0.05). CONCLUSION: Long noncoding RNA LINC00426 was downregulated in the tumor tissue of NSCLC patients and correlated with poor prognosis.