Quantitative proteomic analysis of the miR-148a-associated mechanisms of metastasis in non-small cell lung cancer.

MicroRNAs (miRs) are small non-coding RNAs that regulate gene expression and protein synthesis. Our previous study demonstrated that miR-148a suppressed the metastasis of non-small cell lung cancer (NSCLC) in vitro and in vivo. However, the modulatory mechanism of this effect remains unclear. In the present study, quantitative proteomic technology was used to study the protein expression profile of SPC-A-1 cells subsequent to the downregulation of miR-148a expression, in order to elucidate the molecular mechanism of the suppression of NSCLC metastasis by miR-148a. The differentially expressed proteins identified were analyzed using bioinformatics tools, including the Database for Annotation, Visualization and Integrated Discovery and the Search Tool for the Retrieval of Interacting Genes/proteins. In two experiments, 4,048 and 4,083 proteins were identified, and 4,014 and 4,039 proteins were quantified, respectively. In total, 44 proteins were upregulated and 40 proteins were downregulated. This was verified at the protein and mRNA levels by western blotting and reverse transcription-quantitative polymerase chain reaction, respectively. Bioinformatics analysis was used to identify potential interactions and signaling networks for the differentially expressed proteins. This may have provided an appropriate perspective for the comprehensive analysis of the modulatory mechanism underlying the metastasis-suppressive effects of miR-148a in NSCLC. In conclusion, quantitative proteomic technology revealed that miR-148a may regulate a panel of tumor-associated proteins to suppress metastasis in NSCLC.