Diagnostic Value of MiR-125b as a Potential Biomarker for Stage I Lung Adenocarcinoma.

Background: We aimed at exploring biological functions of differentially expressed miRNAs during carcinogenesis, to identify miRNAs dysegulations involved in DNA repair mechanisms, and to evaluate potential of miRNAs as prognostic and diagnostic biomarkers for early lung adenocarcinomas (LAC).

Methods: We obtained 21 LAC and paired adjacent normal formalin-fixed, paraffinembedded lung tissues from patients who underwent curative resection for stage I LAC. We compared expression levels of eight miRNAs involved in the DNA repair mechanism between LAC and adjacent tissues.

Results: Expressions of Hsa-miR-9-5p, hsa-miR-24-3p, hsa-miR-125a-3p, hsa-miR- 125b-5p, hsa-miR-155-5p, and hsa-let-7a-5p were significantly up-regulated in stage I LAC tissues compared with those in the adjacent tissues. In addition, expressions of hsa-mir-9-5p, hsa-mir-24-3p, hsa-mir-125a-3p, hsa-mir-125b-5p, and hsa-mir-155-5p were significantly up-regulated in stage Ia LAC tissues, whereas expressions of hsa-mir- 125a-3p and hsa-mir-125b-5p were significantly up-regulated in stage Ib LAC tissues. Receiver operating characteristic (ROC) analysis revealed that AUROC of hsa-mir-125b- 5p was 0.875 (P < 0.001).

Conclusion: Expression of hsa-mir-125b-5p could be used to distinguish LAC from adjacent tissues. Our result suggests that hsa-mir125b-5p can be a prognostic and diagnostic biomarker for LAC.