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.