title: Downregulation of RPL6 by siRNA inhibits proliferation and cell cycle progression of human gastric cancer cell lines.
abstract: Our previous study revealed that human ribosomal protein L6 (RPL6) was up-regulated in multidrug-resistant gastric cancer cells and over-expression of RPL6 could protect gastric cancer from drug-induced apoptosis. It was further demonstrated that up-regulation of RPL6 accelerated growth and enhanced in vitro colony forming ability of GES cells while down-regulation of RPL6 exhibited the opposite results. The present study was designed to investigate the potential role of RPL6 in therapy of gastric cancer for clinic. The expression of RPL6 and cyclin E in gastric cancer tissues and normal gastric mucosa was evaluated by immunohistochemisty. It was found that RPL6 and cyclin E were expressed at a higher level in gastric cancer tissues than that in normal gastric mucosa and the two were correlative in gastric cancer. Survival time of postoperative patients was analyzed by Kaplan- Meier analysis and it was found that patients with RPL6 positive expression showed shorter survival time than patients that with RPL6 negative expression. RPL6 was then genetically down-regulated in gastric cancer SGC7901 and AGS cell lines by siRNA. It was demonstrated that down-regulation of RPL6 reduced colony forming ability of gastric cancer cells in vitro and reduced cell growth in vivo. Moreover, down-regulation of RPL6 could suppress G1 to S phase transition in these cells. Further, we evidenced that RPL6 siRNA down-regulated cyclin E expression in SGC7901 and AGS cells. Taken together, these data suggested that RPL6 was over-expressed in human gastric tissues and caused poor prognosis. Down-regulation of RPL6 could suppress cell growth and cell cycle progression at least through down-regulating cyclin E and which might be used as a novel approach to gastric cancer therapy.
authors: State Key Laboratory of Cancer Biology, Xijing Hospital of Digestive Diseases, the Fourth Military Medical University, Xi'an, Shaanxi, China.
authors: Qiong
authors: Q
authors: Wu
authors: Yawen
authors: Y
authors: Gou
authors: Qiaomin
authors: Q
authors: Wang
authors: Haifeng
authors: H
authors: Jin
authors: Lina
authors: L
authors: Cui
authors: Yongguo
authors: Y
authors: Zhang
authors: Lijie
authors: L
authors: He
authors: Jingbo
authors: J
authors: Wang
authors: Yongzhan
authors: Y
authors: Nie
authors: Yongquan
authors: Y
authors: Shi
authors: Daiming
authors: D
authors: Fan
mesh_terms: D002453:Cell Cycle / Q000187:drug effects*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects*; D015536:Down-Regulation / Q000235:genetics*; D006801:Humans; D034741:RNA, Small Interfering / Q000494:pharmacology*; D012269:Ribosomal Proteins / Q000235:genetics*; D013274:Stomach Neoplasms / Q000473:pathology*
chemical_list: D034741:RNA, Small Interfering; D012269:Ribosomal Proteins; C031249:ribosomal protein L6