title: Receptor for activated protein kinase C 1 suppresses gastric tumor progression through nuclear factor-kB pathway.
abstract: OBJECTIVE
  Nuclear factor-kB (NF-kB) activity is crucial for survival and proliferation of many kinds of malignancies, including gastric cancer (GC). The receptor for activated protein kinase C 1 (RACK1) is known to regulate tumor development, whereas the underlined mechanism has not been described clearly.
  
  
  METHODS
  We analyzed expression of RACK1 in paired human GC samples by both real-time polymerase chain reaction (PCR) and western blot. Effects of RACK inhibition with small interfering RNA or its overexpression in cultured GC cell lines were evaluated in cell viabilities. NF-kB signaling was investigated using luciferase reporter assay and real-time PCR.
  
  
  RESULTS
  RACK1 was significantly decreased in GC samples. Knockdown of RACK elevated GC cell viabilities, whereas overexpression of RACK1 suppressed tumorigenesis of GC cells. Importantly, NF-kB signaling was enhanced after RACK1 expression was inhibited, suggesting the negative regulation of the pro-oncogenic NF-kB activity by RACK1 might contribute to its tumor suppressor role in GC cells.
  
  
  CONCLUSIONS
  Our results support that RACK1 suppresses gastric tumor progression through the NF-kB signaling pathway.
authors.affiliation: Department of General Surgery, Huaihe Hospital of Henan University, Kaifeng 475000, Henan Province, PR China.
authors.forename: X
authors.initials: X
authors.lastname: Yong-Zheng
authors.affiliation: Department of General Surgery, Huaihe Hospital of Henan University, Kaifeng 475000, Henan Province, PR China.
authors.forename: M
authors.initials: M
authors.lastname: Wan-Li
authors.affiliation: Department of General Surgery, Huaihe Hospital of Henan University, Kaifeng 475000, Henan Province, PR China.
authors.forename: M
authors.initials: M
authors.lastname: Ji-Ming
authors.affiliation: Department of General Surgery, Huaihe Hospital of Henan University, Kaifeng 475000, Henan Province, PR China.
authors.forename: R
authors.initials: R
authors.lastname: Xue-Qun
mesh_terms: D045744:Cell Line, Tumor; D018450:Disease Progression; D019204:GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D016328:NF-kappa B / Q000378:metabolism*; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods; D000075370:Receptors for Activated C Kinase; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D013274:Stomach Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D014162:Transfection
chemical_list: D016328:NF-kappa B; D009363:Neoplasm Proteins; C419368:RACK1 protein, human; D000075370:Receptors for Activated C Kinase; D011956:Receptors, Cell Surface; D019204:GTP-Binding Proteins