Overexpression of CUGBP1 is associated with the progression of non-small cell lung cancer.

The multifunctional RNA-binding protein CUGBP1 regulates multiple aspects of nuclear and cytoplasmic messenger RNA (mRNA) processing, including splicing, stabilization, and translation of mRNAs. Previous studies have shown that CUGBP1 is overexpressed in non-small-cell lung cancer (NSCLC) tissues, but the pathological functions of CUGBP1 in tumorigenesis and development are unknown. Here, we provide the first evidence demonstrating the clinicopathological significance of CUGBP1 in NSCLC. Using immunohistochemistry, the levels of CUGBP1 expression in NSCLC tissues and adjacent non-cancerous tissues were examined and determined to be associated with differentiation. Short hairpin RNA-induced downregulation of CUGBP1 promoted apoptosis and decreased proliferation in the A549 NSCLC cell line. Moreover, Western blot analysis indicated that the depletion of CUGBP1 increased the protein levels of cyclin D1, BAD, BAX, Jun D, and E-cadherin, while the cyclin B1 level decreased. Knockdown of CUGBP1 decreased β-catenin and vimentin levels and increased E-cadherin expression, suggesting that CUGBP1 may contribute significantly to epithelial to mesenchymal transition (EMT) progression. These results demonstrate the importance of CUGBP1 in the biological and pathological functions of NSCLC and indicate its potential as a therapeutic target for NSCLC.