title: Reduced expression of PTPRD correlates with poor prognosis in gastric adenocarcinoma.
abstract: BACKGROUND
  PTPRD, encoding protein tyrosine phosphatases receptor type D, is located at chromosome 9p23-24.1, a loci frequently lost in many types of tumors. Recently, PTPRD has been proposed to function as a tumor suppressor gene. The current study aimed to investigate PTPRD expression and its prognostic significance in primary gastric adenocarcinoma.
  
  
  RESULTS
  Quantitative real time reverse transcription PCR (qRT-PCR) and western blotting were used to examine PTPRD expression in paired gastric tumourous and paracancerous tissues. Compared with the matched normal gastric mucosa tissues, both the mRNA (P = 0.0138) and protein (P = 0.0093) expression of PTPRD in fresh surgical specimens were significantly reduced. Clinicopathological and prognostic roles of PTPRD in gastric adenocarcinoma were investigated using immunohistochemistry with 513 paraffin-embedded gastric adenocarcinoma tissue blocks. Statistical analysis revealed that reduced PTPRD expression was significantly associated with T stage (P = 0.004), TNM stage (P<0.001) and tumor size (P = 0.003). Furthermore, Kaplan-Meier survival analysis revealed that low expression of PTPRD significantly correlated with poor survival of gastric cancer patients (P<0.001). Cox regression analysis confirmed PTPRD expression as independent predictor of the overall survival of gastric cancer patients. The MTT assay determined the effects of PTPRD on cell proliferation of MGC803 and GES1 cell lines. Restoring PTPRD expression in MGC803 cells significantly inhibited their growth rate. Silencing PTPRD expression by siRNA treatment in GES1 significantly enhanced cell proliferation compared with mock siRNA treatment. Methylation analysis of PTPRD promoter CpG island in 3 primary GC samples showed one case with partial methylation.
  
  
  CONCLUSIONS
  These results indicated that PTPRD is a candidate tumour suppressor in gastric cancer. Thus, PTPRD may play an important role in gastric tumorigenesis and serve as a valuable prognostic marker of gastric adenocarcinoma.
authors.affiliation: Key Laboratory for Biotech-Drugs Ministry of Health, Key Laboratory for Modern Medicine and Technology of Shandong Province, Key Laboratory for Rare & Uncommon Diseases of Shandong Province, Key Laboratory for Virology of Shandong Province, Back and Neck Pain Hospital of Shandong Academy of Medical Sciences, Shandong Medicinal Biotechnology Centre, Shandong Academy of Medical Sciences, Jinan, People's Republic of China.
authors.forename: Dandan
authors.initials: D
authors.lastname: Wang
authors.affiliation: Biology Institute of Shandong Academy of Sciences, Jinan, People's Republic of China.
authors.forename: Leilei
authors.initials: L
authors.lastname: Wang
authors.affiliation: Departments of Oncology, Provincial Hospital Affiliated to Shandong University, Jinan, People's Republic of China.
authors.forename: Jun
authors.initials: J
authors.lastname: Zhou
authors.affiliation: Key Laboratory for Biotech-Drugs Ministry of Health, Key Laboratory for Modern Medicine and Technology of Shandong Province, Key Laboratory for Rare & Uncommon Diseases of Shandong Province, Key Laboratory for Virology of Shandong Province, Back and Neck Pain Hospital of Shandong Academy of Medical Sciences, Shandong Medicinal Biotechnology Centre, Shandong Academy of Medical Sciences, Jinan, People's Republic of China.
authors.forename: Jihong
authors.initials: J
authors.lastname: Pan
authors.affiliation: The General Hospital of Jinan Military Command, Jinan, People's Republic of China.
authors.forename: Wei
authors.initials: W
authors.lastname: Qian
authors.affiliation: Key Laboratory for Biotech-Drugs Ministry of Health, Key Laboratory for Modern Medicine and Technology of Shandong Province, Key Laboratory for Rare & Uncommon Diseases of Shandong Province, Key Laboratory for Virology of Shandong Province, Back and Neck Pain Hospital of Shandong Academy of Medical Sciences, Shandong Medicinal Biotechnology Centre, Shandong Academy of Medical Sciences, Jinan, People's Republic of China.
authors.forename: Jiafang
authors.initials: J
authors.lastname: Fu
authors.affiliation: Key Laboratory for Biotech-Drugs Ministry of Health, Key Laboratory for Modern Medicine and Technology of Shandong Province, Key Laboratory for Rare & Uncommon Diseases of Shandong Province, Key Laboratory for Virology of Shandong Province, Back and Neck Pain Hospital of Shandong Academy of Medical Sciences, Shandong Medicinal Biotechnology Centre, Shandong Academy of Medical Sciences, Jinan, People's Republic of China.
authors.forename: Genglin
authors.initials: G
authors.lastname: Zhang
authors.affiliation: Key Laboratory for Biotech-Drugs Ministry of Health, Key Laboratory for Modern Medicine and Technology of Shandong Province, Key Laboratory for Rare & Uncommon Diseases of Shandong Province, Key Laboratory for Virology of Shandong Province, Back and Neck Pain Hospital of Shandong Academy of Medical Sciences, Shandong Medicinal Biotechnology Centre, Shandong Academy of Medical Sciences, Jinan, People's Republic of China.
authors.forename: Youming
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: Key Laboratory for Biotech-Drugs Ministry of Health, Key Laboratory for Modern Medicine and Technology of Shandong Province, Key Laboratory for Rare & Uncommon Diseases of Shandong Province, Key Laboratory for Virology of Shandong Province, Back and Neck Pain Hospital of Shandong Academy of Medical Sciences, Shandong Medicinal Biotechnology Centre, Shandong Academy of Medical Sciences, Jinan, People's Republic of China.
authors.forename: Chunshan
authors.initials: C
authors.lastname: Liu
authors.affiliation: Key Laboratory for Biotech-Drugs Ministry of Health, Key Laboratory for Modern Medicine and Technology of Shandong Province, Key Laboratory for Rare & Uncommon Diseases of Shandong Province, Key Laboratory for Virology of Shandong Province, Back and Neck Pain Hospital of Shandong Academy of Medical Sciences, Shandong Medicinal Biotechnology Centre, Shandong Academy of Medical Sciences, Jinan, People's Republic of China.
authors.forename: Chunliang
authors.initials: C
authors.lastname: Wang
authors.affiliation: Key Laboratory for Biotech-Drugs Ministry of Health, Key Laboratory for Modern Medicine and Technology of Shandong Province, Key Laboratory for Rare & Uncommon Diseases of Shandong Province, Key Laboratory for Virology of Shandong Province, Back and Neck Pain Hospital of Shandong Academy of Medical Sciences, Shandong Medicinal Biotechnology Centre, Shandong Academy of Medical Sciences, Jinan, People's Republic of China.
authors.forename: Zongkun
authors.initials: Z
authors.lastname: Jin
authors.affiliation: Key Laboratory for Biotech-Drugs Ministry of Health, Key Laboratory for Modern Medicine and Technology of Shandong Province, Key Laboratory for Rare & Uncommon Diseases of Shandong Province, Key Laboratory for Virology of Shandong Province, Back and Neck Pain Hospital of Shandong Academy of Medical Sciences, Shandong Medicinal Biotechnology Centre, Shandong Academy of Medical Sciences, Jinan, People's Republic of China.
authors.forename: Ziqing
authors.initials: Z
authors.lastname: He
authors.affiliation: Key Laboratory for Biotech-Drugs Ministry of Health, Key Laboratory for Modern Medicine and Technology of Shandong Province, Key Laboratory for Rare & Uncommon Diseases of Shandong Province, Key Laboratory for Virology of Shandong Province, Back and Neck Pain Hospital of Shandong Academy of Medical Sciences, Shandong Medicinal Biotechnology Centre, Shandong Academy of Medical Sciences, Jinan, People's Republic of China.
authors.forename: Jianmei
authors.initials: J
authors.lastname: Wu
authors.affiliation: Key Laboratory for Biotech-Drugs Ministry of Health, Key Laboratory for Modern Medicine and Technology of Shandong Province, Key Laboratory for Rare & Uncommon Diseases of Shandong Province, Key Laboratory for Virology of Shandong Province, Back and Neck Pain Hospital of Shandong Academy of Medical Sciences, Shandong Medicinal Biotechnology Centre, Shandong Academy of Medical Sciences, Jinan, People's Republic of China.
authors.forename: Bin
authors.initials: B
authors.lastname: Shi
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis* / Q000401:mortality / Q000473:pathology; D000368:Aged; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D002899:Chromosomes, Human, Pair 9; D018899:CpG Islands; D019175:DNA Methylation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D011401:Promoter Regions, Genetic; D034622:RNA Interference; D054623:Receptor-Like Protein Tyrosine Phosphatases, Class 2 / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D013274:Stomach Neoplasms / Q000175:diagnosis* / Q000401:mortality / Q000473:pathology
chemical_list: C090899:PTPRD protein, human; D054623:Receptor-Like Protein Tyrosine Phosphatases, Class 2