Inhibition of proliferation, invasion, and migration of prostate cancer cells by downregulating elongation factor-1alpha expression.

Overexpression of elongation factor-1alpha (EF-1alpha) has been reported to contribute to the development and progression of various cancers. However, its role in prostate cancer (PCa) still remains poorly understood. In the present study, we investigate the influence of EF-1alpha in Du145, a high-grade metastatic PCa cell line, and demonstrate that EF-1alpha plays an essential role in cellular properties associated with tumor progression, namely cell proliferation, invasion, and migration. In this study, EF-1alpha expression in human PCa cell line Du145 was reduced by RNA interference (RNAi) technology, and the proliferation, invasion, and migration of EF-1alpha-reduced Du145 cells were examined. We also detected an EF-1alpha expression pattern in 20 pairs of primary PCa samples and their corresponding normal tissues. Expression of EF-1alpha was detectable in four PCa cell lines (22RV1, LnCap, Du145, and PC3), indicating its possible role in pathogenesis of PCa. RNAi-mediated knockdown of EF-1alpha expression in Du145 cells, which expressed the highest level of EF-1alpha among four PCa cell lines, led to a decrease in proliferation. Similarly, suppression of EF-1alpha inhibited Du145 cell migration and invasion through a basement membrane substitute. Furthermore, we found that the normal prostate tissues showed a relatively low level of EF-1alpha expression, whereas PCa tissues demonstrated significantly higher expression levels of EF-1alpha (P < 0.001). Taken together, these findings support the hypothesis that EF-1alpha affects multiple processes involved in tumor progression, and identify EF-1alpha as a potential therapeutic target.