Quantitative Proteomics of miR-148a in gastric cancer cells

A quantitative proteomics combined with stable isotope labeling was applied to identify the global profile of miR-148a-regulated downstream proteins in AGS cancer cells. For proteomic analysis, cells were treated with miR-148a mimic (Pre-miR-148a) or miR-148a negative control (miR-CTL) and the downstream protein expression level (Pre-miR-148a/miR-CTL) were quantified using iTRAQ approach. Bioinformatics pipeline: The peak list in the resultant MS/MS spectra were generated by Mascot Distiller v2.1.1.0  and searched using Mascot v2.2 against the International Protein Index (IPI) human database (v. 3.64, 84032 sequences). The Mascot search parameters were +-0.1 Da for MS tolerance, +-0.1 Da for MS/MS mass tolerance, allowances for two missed cleavages, and variable modifications of deamidation (NQ), oxidation (M), iTRAQ (N terminal), iTRAQ (K), and MMTS (C). Protein quantitation were calculated using the Multi-Q software v1.6.5.4 with a dynamic range filter of ion count > 30.