title: Lower expression of PH domain leucine-rich repeat protein phosphatase 1 (PHLPP1) association with poor prognosis of gastric cancer.
abstract: BACKGROUND
  The aim of this study was to investigate the expression of PH domain leucine-rich repeat protein phosphatase 1 (PHLPP1) in gastric cancer (GC), and its potential influence on the prognosis of GC patients.
  
  
  METHODS
  At present study, we examined the immunohistochemical expression of PHLPP1 on tissue microarrays (TMAs) containing 135 gastric adenocarcinoma tissues and 135 matched adjacent non-tumor tissues. In addition, both semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) and western blotting analysis (WB) were adopted to detect of the expression of PHLPP1 in the GC cell lines (AGS, SUN-1, KATO-III, BGC-823, MGC-803, SGC-7901, and HGC-27) and the normal gastric cell line GES-1. Survival analysis was used to investigate the efficiency of the prognostic evaluation of PHLPP1 expression in GC patients.
  
  
  RESULTS
  Positive expression rate of PHLPP1 in the primary GC tissues was significantly lower than that in adjacent non-tumor tissues (55.6% vs. 87.4%, P<0.001). Both gene transcription (mRNA) and Protein expression of PHLPP1 in the GC cell lines were significantly lower than those in the GES-1 cell line, respectively. The Kaplan-Meier analysis showed that patients presented PHLPP1 negative expression in the GC tissues had significantly lower overall survival rate than those presented PHLPP1 positive expression in the GC tissues (P=0.008). With the multivariate survival analysis (Cox regression), PHLPP1 expression in the GC tissue was identified as an independent predictor of the survival of patients.
  
  
  CONCLUSIONS
  This study indicated that aberrant PHLPP1 expression was observed in GC tissues, which was significantly associated with the poor prognostic outcomes of GC patients.
authors.affiliation: Department of Gastroenterology, Tianjin Medical University Cancer Hospital, City Key Laboratory of Tianjin Cancer Center and National Clinical Research Center for Cancer Tianjin, China.
authors.forename: Yachao
authors.initials: Y
authors.lastname: Hou
authors.affiliation: Department of Gastroenterology, Tianjin Medical University Cancer Hospital, City Key Laboratory of Tianjin Cancer Center and National Clinical Research Center for Cancer Tianjin, China.
authors.forename: Jingyu
authors.initials: J
authors.lastname: Deng
authors.affiliation: Department of Gastroenterology, Tianjin Medical University Cancer Hospital, City Key Laboratory of Tianjin Cancer Center and National Clinical Research Center for Cancer Tianjin, China.
authors.forename: Li
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Gastroenterology, Tianjin Medical University Cancer Hospital, City Key Laboratory of Tianjin Cancer Center and National Clinical Research Center for Cancer Tianjin, China.
authors.forename: Xingming
authors.initials: X
authors.lastname: Xie
authors.affiliation: Department of Gastroenterology, Tianjin Medical University Cancer Hospital, City Key Laboratory of Tianjin Cancer Center and National Clinical Research Center for Cancer Tianjin, China.
authors.forename: Xiaofan
authors.initials: X
authors.lastname: Guo
authors.affiliation: Department of Gastroenterology, Tianjin Medical University Cancer Hospital, City Key Laboratory of Tianjin Cancer Center and National Clinical Research Center for Cancer Tianjin, China.
authors.forename: Changyu
authors.initials: C
authors.lastname: Sun
authors.affiliation: Department of Gastroenterology, Tianjin Medical University Cancer Hospital, City Key Laboratory of Tianjin Cancer Center and National Clinical Research Center for Cancer Tianjin, China.
authors.forename: Rupeng
authors.initials: R
authors.lastname: Zhang
authors.affiliation: Department of Gastroenterology, Tianjin Medical University Cancer Hospital, City Key Laboratory of Tianjin Cancer Center and National Clinical Research Center for Cancer Tianjin, China.
authors.forename: Han
authors.initials: H
authors.lastname: Liang
keywords: PH domain leucine-rich repeat protein phosphatase 1; immunohistochemical; neoplasm; prognosis; stomach