Relative expressions of miR-205-5p, miR-205-3p, and miR-21 in tissues and serum of non-small cell lung cancer patients

Objective was to assess and compare the relative expressions of miR-205-5p, miR-205-3p, and miR-21-3p in tissues and serum among non-small cell lung carcinoma (NSCLC) patients, benign pulmonary conditions patients, and healthy volunteers. Serum samples were obtained between October 2011 and September 2012 from 20 NSCLC patients undergoing surgical treatment, 20 patients diagnosed with a benign lung disease (pulmonary tuberculosis, pneumonia, chronic obstructive pulmonary disease, or interstitial pneumonia) (lesion group), and 20 healthy volunteers (control group). NSCLC patients provided cancer tissues and cancer-adjacent normal tissues during surgery (paired specimens). Quantitative RT-PCR was used to assess miR-205-5p, miR-205-3p, and miR-21-3p expressions in serum and tissue samples. The relative expressions of miR-205-5p and miR-205-3p were significantly higher in NSCLC tissues compared with cancer-adjacent paired specimens (both P < 0.001). In the serum, significantly higher miR-205-5p, miR-205-3p, and miR-21-3p relative expressions were observed in the NSCLC group compared with the two other groups (all P < 0.001). The relative expressions of miR-205-5p and miR-21-3p in NSCLC tissues and serum were significantly correlated (r = 0.553, P = 0.011; and r = -0.541, P = 0.014, respectively), while no significant correlation was observed for miR-205-3P (P = 0.120). Expressions of miR-205-5p and miR-205-3P in squamous cell carcinoma specimens were significantly higher than in lung adenocarcinoma specimens (both P = 0.001). Similarly, higher serum miR-205-5p and miR-205-3p levels were observed in squamous cell carcinoma patients (P = 0.033 and P = 0.002, respectively). In this preliminary and novel study, miR-205-5p was more useful as a marker for NSCLC than miR-205-3p or miR-21, indicating a potential for future applications in NSCLC diagnosis and prognosis.