Comparative proteomic profiling of human lung adenocarcinoma cells (CL 1-0) expressing miR-372

Lung cancer is a common malignancy and has a poor overall prognosis. Widespread metastasis is a common phenomenon in non-small cell lung cancer (NSCLC). It has been demonstrated that cancer relapse and survival can be predicted by the presence of a five-microRNA (miRNA) signature independent of stage or histologic type in NSCLC patients. Among the five miRNAs in the signature, miR-372 has been shown to play a significant role in metastasis and in the development of human testicular germ cell tumors. In addition, there is evidence that miR-372 posttranscriptionally downregulates large tumor suppressor, homolog 2 (Lats2), resulting in tumorigenesis and proliferation. To further investigate the cellular mechanisms involved in miR-372-induced silencing, we conducted a comparative proteomic analysis of NSCLC CL 1-0 cells expressing miRNA-372 and/or vector only by using two-dimensional gel electrophoresis (2DE), two-dimensional difference gel electrophoresis (2D-DIGE), and LC/MS/MS. Proteins identified as being up- or downregulated were further classified according to their biological functions. Many of the proteins identified in our study may be potential diagnostic biomarkers of NSCLC, particularly phosphorylated eIF4A-I.