Expression of Five Important Biomarkers in Non-small Cell Lung Cancer: MicroRNAs-128, miR-335-5p, miR-1254, VEGF, and K-RAS

Background: Lung cancers, such as non-small cell lung cancer (NSCLC), are the most common malignancy and leading cause of cancer-related death worldwide. MicroRNAs (miRNAs) play a role in the occurrence of lung cancer by targeting both tumor suppressor genes and oncogenes. Among them, miR-128, miR-335-5p, and miR-1254 are mainly reported to function in regulating lung cancer cell behavior. Objectives: The aim of the study was to investigate the existence and expression levels of miRNA-128, miR-335-5p, and miR-1254 as well as mRNA and protein expression levels of VEGF and mRNA expression levels of K-RAS in both peripheral blood and cancerous tissue of NSCLC patients compared to the healthy subjects. Methods: Blood and tissue samples were collected from 50 healthy donors and 50 NSCLS patients. The serum level of VEGF was measured using the commercial enzyme-linked immunosorbent assay (ELISA). The mRNA expression levels of K-RAS and VEGF, as well as the expression of miRNA-128, miR-335-5p, and miR-1254, were determined, using real-time PCR. Results: Lower mRNA expression levels of miRNA-128, miR-335-5p, and miR-1254, as well as higher mRNA expression levels of VEGF and K-RAS, were detected in both peripheral blood and tissue samples from NSCLC patients compared to those of the healthy subjects. The VEGF protein levels in the peripheral blood of the patients were also found to be significantly lower than those in the healthy subjects. Conclusions: The findings from this study suggest that miR-335-5p, miR-1254, and miR-128, may contribute to the pathogenesis and tumorigenesis of NSCLC at least in part by modulation of proliferation, migration, and angiogenesis via targeting VEGF and K-RAS signaling pathways. K-RAS and VEGF may be target genes for miR-335-5p, miR-1254, and miR-128 in NSCLC patients.