In the recent years, microRNAs (miRNAs) have been discovered to play a very important role in biological processes such as development, differentiation, and apoptosis. The miRNA expression levels in cells are associated with diverse diseases including cancers. MiRNA inhibitors have been widely employed for studying the functions and targets of miRNAs by transfecting the inhibitors into cells. The concentrations of miRNA inhibitors used for such studies can vary depending on the types of miRNAs being tested, the cell lines under study, and the analysis methods. Therefore, in order to obtain accurate results, appropriate amounts of miRNA inhibitors have to be used in the experiments. Apart from amounts, the evaluation of inhibitors may also have to be conducted for functional studies.
Here we developed capillary electrophoresis with laser-induced fluorescence (CE-LIF) method for evaluating miRNA inhibitor and for optimizing miRNA inhibitor concentrations, in the A549 lung cancer cell line. The target miRNAs, miRNA-23a and miRNA-24 are biomarker candidates in lung cancer cell lines. Our results showed that miRNA-23a and miRNA-24 were effectively inhibited upon transfection with 20 nM miRNA inhibitors using CE-LIF method. Furthermore, these results demonstrated the potential of CE for fast, specific, sensitive and specific analyses for the evaluation and determination of the optimal concentration of miRNA inhibitors for functional studies.