The reduced expression of RBM5 protein

was associated with tobacco smoke, tumor stages, and lymph node metastasis of NSCLC, while overexpression of EGFR and KRAS proteins was associated with tumor stages and lymph node metastasis of NSCLC. Overexpression of KRAS protein occurred more frequently in smokers with NSCLC. Moreover, expression of RBM5 mRNA and protein was negatively associated with expression of EGFR and KRAS mRNA and protein in NSCLC tissues. The data from the current study suggest that expression of RBM5 mRNA and protein is worth further evaluation as a biomarker for tumor diagnosis. Previous studies have shown that RBM5 expression was frequently reduced in different cancers, including breast MLN4924 order cancer [20], human schwannoma [23] and 75 % of primary lung cancer specimens [24]. In the present study, expression levels of RBM5 protein were reduced in NSCLC compared with the non-tumor tissues, suggesting that RBM5 could play a role in suppression of NSCLC development or progression. Furthermore, the expression level of RBM5 was shown to be high in the adult thymus and low in the fetal thymus, indicating that RBM5 expression may be developmentally regulated [17]. RBM5 protein is a negative regulator

of cell proliferation: overexpression of the full length LUCA-15/RBM5 in breast cancer CEM-C7 and NSCLC A549 cells p38 MAPK assay suppressed check details cell proliferation through induction of apoptosis and arrest of tumor cells at the G1 phase of the cell cycle [16]. These data together suggest that the loss of RBM5 expression in different cancer tissues and cells contributes to tumor growth via regulation of cell proliferation and apoptosis. Moreover, our current study also showed that expression of RBM5 protein in NSCLC tissues was negatively correlated with tobacco smoke, The data that decreased expression of RBM5 protein was more frequent

in smokers than in non-smokers suggest tobacco carcinogens may lead to the loss of RBM5 expression in NSCLC, which is in agreement Reverse transcriptase with previous studies that had shown deletions at 3p21.3 were the earliest lesions in lung cancer, and were associated with smoking alone [15]. In addition, tumor metastasis, the major cause of cancer death, is a multistep process that requires interactions between cancer cells, stromal cells, and the extracellular matrix. In this study, we found that reduced expression of RBM5 protein was associated with lymph node metastasis of NSCLC, indicating that RBM5 may play a potential role in the suppression of tumor metastasis.