Long Non-Coding RNA SNHG4 Is a Potential Diagnostic and Prognostic Indicator in Non-Small Cell Lung Cancer

The mortality rate of non-small cell lung cancer ranks first worldwide. The lack of effective and accurate diagnosis contributes to the unfavorable prognosis of non-small cell lung cancer patients since most of them are diagnosed at an advanced stage. In the present study, we aimed to investigate whether LncRNA SNHG4 was implicated in predicting non-small cell lung cancer diagnosis and outcomes.

We collected 68 unpaired serums and tissues from patients with non-small cell lung cancer and from healthy volunteers. Quantitative real-time polymerase chain reaction (qRT-PCR) assays were conducted accordingly. Furthermore, we uncovered the correlation of their expressions with clinicopathological features and the diagnostic values. The five-year survival rate and disease-free rate were analyzed using Kaplan-Meier methods. Finally, in vitro experiments were performed to explore the role and mechanisms of LncRNA SNHG4 in non-small cell lung cancer.

LncRNA SNHG4 level was significantly more elevated in non-small cell lung cancer serum samples and tissues than in healthy controls (P<0.01). A receiver operating characteristic (ROC) assay demonstrated that the areas under the curve (AUC) were 0.9087 (95% CI, 0.8529 to 0.9646; specificity=98.53%, sensitivity=80.88%, cutoff=1.7941) and 0.9457 (95% CI, 0.8994 to 0.9920; specificity=100.00%, sensitivity=82.80%, cutoff=1.828), separately. Notably, a higher expression of LncRNA SNHG4 was positively correlated with the clinical stage, lymph node metastasis, and smoking. Meanwhile, patients with higher expressions of LncRNA SNHG4 had significantly lower overall survival rates and disease-free rates. In the in vitro experiments, we found that LncRNA SNHG4 was strongly elevated in the non-small cell lines compared with the human normal lung epithelial cell line BEAS-2B. After transfection with the SNHG4 silencing plasmid, A549 cell viability was significantly inhibited, while apoptosis was promoted.

LncRNA SNHG4 might have diagnostic and prognostic significance in non-small cell lung cancer. However, it is imperative to conduct further experiments on the aspect of the biological mechanisms of LncRNA SNHG4 in the occurrence and development of non-small cell lung cancer.