title: Gene amplification of ribosomal protein S6 kinase-1 and -2 in gastric cancer.
abstract: BACKGROUND
  The gene amplification of ribosomal protein S6 kinase 1 and 2 (S6K1 and S6K2) and its clinical relevance in gastric cancer remain unclear.
  
  
  METHODS
  A comparative genomic hybridization analysis and DNA copy number assay were performed for nine cancer cell lines. The gene amplification of S6K1 and S6K2 were determined using a DNA copy number assay of 213 gastric cancer tissues.
  
  
  RESULTS
  S6K1 and S6K2 amplifications were observed in one and three cancer cell lines, respectively. No amplification of S6K1 was detected in the gastric cancer tissues, while S6K2 amplification was observed in 4.7% of the gastric carcinoma tissues. Patients with stage IV gastric cancer whose tumors exhibited amplification had a significantly shorter overall survival.
  
  
  CONCLUSIONS
  S6K2 amplification was frequently observed in gastric cancer and was related to a poor prognosis. Our findings may provide novel insight into the dysregulation of mammalian target of rapamycin signaling by S6K2 amplification in gastric cancer.
authors: Department of Genome Biology, Kinki University Faculty of Medicine, 377-2 Ohno-higashi, Osaka-Sayama, Osaka 589-8511, Japan.
authors: Shuhei
authors: S
authors: Yoshida
authors: Kazuko
authors: K
authors: Matsumoto
authors: Tokuzo
authors: T
authors: Arao
authors: Hirokazu
authors: H
authors: Taniguchi
authors: Isao
authors: I
authors: Goto
authors: Toshiaki
authors: T
authors: Hanafusa
authors: Kazuto
authors: K
authors: Nishio
authors: Yasuhide
authors: Y
authors: Yamada
mesh_terms: D000230:Adenocarcinoma / Q000201:enzymology / Q000235:genetics* / Q000473:pathology; D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis* / Q000235:genetics; D015153:Blotting, Western; D005260:Female; D005784:Gene Amplification; D018628:Gene Dosage; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D038762:Ribosomal Protein S6 Kinases, 70-kDa / Q000096:biosynthesis / Q000235:genetics*; D015398:Signal Transduction / Q000502:physiology; D013274:Stomach Neoplasms / Q000201:enzymology / Q000235:genetics* / Q000473:pathology; D058570:TOR Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism
chemical_list: D014408:Biomarkers, Tumor; C546842:MTOR protein, human; D038762:Ribosomal Protein S6 Kinases, 70-kDa; D058570:TOR Serine-Threonine Kinases; C448901:ribosomal protein S6 kinase, 70kD, polypeptide 1; C448959:ribosomal protein S6 kinase, 70kD, polypeptide 2