Abstract:

Objective To explore the relationship between expression levels of long non-coding RNA (lncRNA) miR503 host gene (MIR503HG) and Wnt1 in non small cell lung cancer (NSCLC) tissue and the survival of patients within 5 years after surgery. Methods A total of 108 NSCLC patients were selected for this study, and lung cancer tissue and paracancer tissue of patients were collected during operation. Fluorescence quantitative PCR was used to detect lncRNA MIR503HG and Wnt1 mRNA expression levels in lung cancer tissue and paracancer tissue. The expression levels of Wnt1 protein in lung cancer tissue and paracancer tissue were determined by immunohistochemistry. Patients with NSCLC were follow up for 5 years after surgery, and their survival status was recorded during the follow-up period. The positive expression of lncRNA MIR503HG and Wnt1 mRNA and protein in paracancer tissue and lung cancer tissue were compared. The expression levels of the above two in lung cancer tissue of NSCLC patients with different outcomes and their differences in different clinicopathological characteristics were compared. Pearson method was used to analyze the correlation between the two expression levels in lung cancer tissue. Kaplan-Meier survival curve was used to analyze the relationship between the expression levels of both in lung cancer tissue and the survival of patients within 5 years after operation. Multivariate Cox regression analysis was used to analyze factors affecting the survival in patients with NSCLC within 5 years after surgery. Receiver operating characteristics (ROC) curves were used to evaluate the predictive values of lncRNA MIR503HG and Wnt1 mRNA expression levels in lung cancer tissue in patients with 5-year postoperative survival. Results LncRNA MIR503HG expression level in lung cancer tissue was lower than those in paracancer tissue. Wnt1 mRNA expression level and Wnt1 protein positive expression rate were higher in lung cancer tissue than that in paracancer tissue (P<0.05). The expression level of lncRNA MIR503HG in lung cancer tissue of NSCLC patients with low differentiation, stage Ⅲ and lymph node metastasis was lower than that of NSCLC patients with medium-high differentiation, stage I-Ⅱ and no lymph node metastasis. The expression level of Wnt1 mRNA in lung cancer tissue of NSCLC patients with low differentiation, stage Ⅲ and lymph nodemetastasis was higher than that of NSCLC patients with medium-high differentiation, stage I-Ⅱ and no lymph node metastasis, respectively (P<0.05). LncRNA MIR503HG and the Wnt1 mRNA expression levels in lung cancer tissue were negatively correlated (P<0.05). A total of 108 NSCLC patients were followed up for 5 years after surgery, with 48 surviving patients (the survival group) and 60 deaths (the death group). The 5-year cumulative survival rate after surgery was higher in the lncRNA MIR503HG high expression group and the Wnt1 mRNA low expression group than that of the lncRNA MIR503HG low expression group and the Wnt1 mRNA high expression group, respectively (P<0.05). Compared with the survival group, lncRNA MIR503HG expression level of lung cancer tissue was decreased and Wnt1 mRNA expression level was increased in the death group (P<0.05). The low expression of lncRNA MIR503HG, high expression of Wnt1 mRNA, low differentiation, stage Ⅲ TNM and lymph node metastasis in lung cancer tissue were all independent risk factors affecting the survival of patients with NSCLC within 5 years after surgery (P<0.05). The area under curve (AUC) of lncRNA MIR503HG, Wnt1 mRNA and their combined in predicting 5-year survival after surgery in NSCLC patients were 0.823, 0.728 and 0.885, respectively, and the combined forecasting was more efficient (P<0.05). Conclusion Low expression of lncRNA MIR503HG and high expression of Wnt1 in lung cancer tissue of NSCLC patients are closely related to the clinicopathological features and survival of patients within 5 years after surgery, and which have a high predictive value for the survival of patients within 5 years after surgery.

Key words: carcinoma, nonsmall-cell lung, RNA, long noncoding, Wnt1 protein, miR503 host gene