Investigation of miR221 and miR222 as biomarkers in non-small cell lung cancer

Abstract

Background/Aim: MicroRNAs (miRNA) are a class of small non-coding RNAs of 18-25 nucleotides, which regulate gene expression at the post-transcriptional level by disrupting or blocking translation of messenger RNA targets. Non-small cell lung cancer (NSCLC) represents approximately 85% of all lung cancers. Early and accurate diagnosis of the disease affects the probability of success of treatment. The purpose of this study was to investigate the expression levels of serum specific miRNA221 and miRNA222 as a biomarker in NSCLC. Materials and Methods: Thirty-two NSCLC cases and 30 healthy control cases that were diagnosed at Istanbul Yedikule Chest Diseases and Thoracic Surgery Training Hospital were included in this study. miRNAs were detected using miRNAspecific quantitative real-time-PCR. The relative expression of miRNAs was calculated using the 2-ccCt method. Results: miR221 and miR222 showed 1.46 and 1.63-fold higher expression in the samples from patients with NSCLC compared to controls, and the difference of expression was statistically significant for miR221 (p=0.000095) but not for miR222 (p=0.084470). In the presence of metastasis in NSCLC patients, miR221 levels were 2.33-fold higher compared to non-metastatic cases (p=0.014), and those of miR221 and miR222 were expressed 1.44 and 1.52-fold higher, respectively, in advanced stage compared to early stage (p=0.000387, p=0.000302). Conclusion: The levels of miR221 and miR222 in the serum of patients could be used as biomarkers for the diagnosis, treatment, and prognosis of NSCLC.