Overexpression of ribosomal protein L15 is associated with cell proliferation in gastric cancer

Background: Ribosomal proteins are the components of ribosome, which also exhibit various secondary functions in DNA repair, apoptosis, drug resistance and proliferation. In our previous study of microarray, ribosomal protein L15 ( RPL15) was identified as an upregulated gene in gastric cancer. Methods: We investigated the expression of ribosomal protein L15 in gastric cancer and the effect of RPL15 on proliferation of gastric cancer. Results: It was found that the expression of RPL15 was markedly up-regulated in gastric cancer tissues. RPL15 was also highly expressed in gastric cancer cell lines AGS, MKN45, MKN28, SGC7901 and KATOIII. Inhibition of RPL15 expression by siRNA vector transfection suppressed the growth of SGC7901 cells significantly, which was independent of the expression of Cyclin D1 and B1. Down-regulation of RPL15 expression inhibited SGC7901 cell growth in soft agar and its tumorigenicity in nude mice. Conclusion: RPL15 promotes cell proliferation and may be a potential target for anticancer therapy of gastric cancer.