The significance of selected miRNAs expression in non-small cell lung cancer

Lung cancer is classified as one of the most serious cause of cancer mortality worldwide. RNA interference (RNAi) is a highly conserved molecular mechanism that is used for post-transcriptional, sequence silencing of gene expression. Functional units of RNAi, responsible for the mechanism of RNAi are small non-coding, endogenous, single-strand RNAs, called microRNAs (miRNAs). The miRNAs, based on the complementarity of target molecules, bind to the mRNA which is either completely degrades or only preventes from translation, without any split.

We studied 65 lung cancer samples and detected levels of miR-21, miR-23a, miR-23b, miR-126, miR-205, miR-335*, miR-3163, miR-491-3p, miR-548p, miR-548x, miR-576-5p, miR-590p, miR- 655, miR-656 and miR-944 with respect to the endogenous control RNU6B using TaqMan® MicroRNA Assays (Ambion). We analysed their expressions in the samples and then correlated with disease free survival (DFS) and overall survival (OS). We found no significant relationships between miR-21, miR-23a, miR-23b, miR-126, miR-335*, miR-3163, miR-491-3p, miR-548p, miR-548x, miR-576-5p, miR-590p, miR-655, miR-656, miR-944 expression and abovementioned parameters. However, miR- 205 was significantly increased in squamous cell carcinomas (p<2.10-3) compared with other subtypes of NSCLC. The expression of miR-205 significantly correlated with the length of DFS and OS (DFS: p<0,015; OS: p<0,01). Our results showed that miR-205 could be used as a diagnostic and prognostic marker for patients with NSCLC.

This work was supported by grants: IGA MZCR 10259-3, GACR303/09/H048, MSM6198959216 and CZ.1.05/2.1.00/01.0030