title: Mitogen-activated protein kinase activator with WD40 repeats (MAWD) and MAWD-binding protein induce cell differentiation in gastric cancer.
abstract: BACKGROUND
  Our previous proteomic analysis revealed that mitogen-activated protein kinase activator with WD40 repeats (MAWD) and MAWD-binding protein (MAWBP) were downregulated in gastric cancer (GC) tissues. These proteins interacted and formed complexes in GC cells. To investigate the role of MAWD and MAWBP in GC differentiation, we analyzed the relationship between MAWD/MAWBP and clinicopathologic characteristics of GC tissues and examined the expression of E-cadherin and pepsinogen C (PGC)-used as gastric mucosa differentiation markers-in MAWD/MAWBP-overexpressing GC cells and xenografts.
  
  
  METHODS
  We measured MAWD, MAWBP, transforming growth factor-beta (TGF-beta), E-cadherin, and PGC expression in 223 GC tissues and matched-adjacent normal tissues using tissue microarray and immunohistochemistry (IHC) analyses, and correlated these expression levels with clinicopathologic features. MAWD and MAWBP were overexpressed alone or together in SGC7901 cells and then E-cadherin, N-cadherin, PGC, Snail, and p-Smad2 levels were determined using western blotting, semiquantitative RT-PCR, and immunofluorescence analysis. Alkaline phosphatase (AKP) activity was measured to investigate the differentiation level of various transfected cells, and the transfected cells were used in tumorigenicity assays and for IHC analysis of protein expression in xenografts.
  
  
  RESULTS
  MAWD/MAWBP positive staining was significantly lower in GC tissues than in normal samples (P < 0.001), and the expression of these proteins was closely correlated with GC differentiation grade. Kaplan-Meier survival curves indicated that low MAWD and MAWBP expression was associated with poor patient survival (P < 0.05). The differentiation-related proteins E-cadherin and PGC were expressed in GC tissues at a lower level than in normal tissues (P < 0.001), but were upregulated in MAWD/MAWBP-overexpressing cells. N-cadherin and Snail expression was strongr in vector-expressing cells and comparatively weaker in MAWD/MAWBP co-overexpressing cells. MAWD/MAWBP co-overexpression inhibited Smad2 phosphorylation and nuclear translocation (P < 0.05), and AKP activity was lowest in MAWD/MAWBP coexpressing cells and highest in vector-expressing cells (P < 0.001). TGF-beta, E-cadherin, and PGC expression in xenograft tumors derived from MAWD/MAWBP coexpressing cells was higher than that in control.
  
  
  CONCLUSIONS
  MAWD and MAWBP were downregulated and associated with the differentiation grade in GC tissues. MAWD and MAWBP might induce the expression of differentiation-related proteins by modulating TGF-beta signaling in GC cells.
authors.affiliation: Department of Biochemistry and Molecular Biology, School of Medicine, Shihezi University, Xinjiang, 832000, P.R China. lidong_abc@126.com.
authors.forename: Dongmei
authors.initials: D
authors.lastname: Li
authors.affiliation: Laboratory of Molecular Oncology, Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Peking University Cancer Hospital/Institute, Beijing, 100142, P.R China. zhangjun@genomics.org.cn.|Beijing Genomics Institute, Chinese Academy of Sciences, Shunyi, Beijing, 101318, P.R China. zhangjun@genomics.org.cn.
authors.forename: Jun
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of General Surgery, First Affiliated Hospital of Shihezi University, Shihezi, Xinjiang, 832008, P.R China. 34576705@qq.com.
authors.forename: Yu
authors.initials: Y
authors.lastname: Xi
authors.affiliation: Department of Laboratory, First Affiliated Hospital of Shihezi University, Shihezi, Xinjiang, 832008 P.R, China. 2446514472@qq.com.
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Laboratory of Molecular Oncology, Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Peking University Cancer Hospital/Institute, Beijing, 100142, P.R China. wenmei_li2002@yahoo.com.cn.
authors.forename: Wenmei
authors.initials: W
authors.lastname: Li
authors.affiliation: Laboratory of Molecular Oncology, Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Peking University Cancer Hospital/Institute, Beijing, 100142, P.R China. jtcui@sina.com.
authors.forename: Jiantao
authors.initials: J
authors.lastname: Cui
authors.affiliation: Laboratory of Molecular Oncology, Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Peking University Cancer Hospital/Institute, Beijing, 100142, P.R China. 860387704@qq.com.
authors.forename: Rui
authors.initials: R
authors.lastname: Xing
authors.affiliation: Laboratory of Molecular Oncology, Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Peking University Cancer Hospital/Institute, Beijing, 100142, P.R China. peter.f.pan@hotmail.com.
authors.forename: Yuanmin
authors.initials: Y
authors.lastname: Pan
authors.affiliation: Department of Biochemistry and Molecular Biology, School of Medicine, Shihezi University, Xinjiang, 832000, P.R China. panzemin89@126.com.
authors.forename: Zemin
authors.initials: Z
authors.lastname: Pan
authors.affiliation: Department of Biochemistry and Molecular Biology, School of Medicine, Shihezi University, Xinjiang, 832000, P.R China. lifeng7855@yahoo.com.cn.
authors.forename: Feng
authors.initials: F
authors.lastname: Li
authors.affiliation: Laboratory of Molecular Oncology, Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Peking University Cancer Hospital/Institute, Beijing, 100142, P.R China. 10989959@bjmu.edu.cn.
authors.forename: Youyong
authors.initials: Y
authors.lastname: Lu
mesh_terms: D000818:Animals; D015415:Biomarkers; D015820:Cadherins / Q000378:metabolism; D045744:Cell Line, Tumor; D002471:Cell Transformation, Neoplastic / Q000235:genetics / Q000378:metabolism; D004195:Disease Models, Animal; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D064593:Heterografts; D006801:Humans; D051379:Mice; D060787:Neoplasm Grading; D009363:Neoplasm Proteins / Q000235:genetics* / Q000378:metabolism; D011379:Prognosis; D060066:Protein Interaction Maps; D011506:Proteins / Q000235:genetics* / Q000378:metabolism; D016601:RNA-Binding Proteins; D015398:Signal Transduction; D013274:Stomach Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000401:mortality / Q000473:pathology*; D016212:Transforming Growth Factor beta / Q000378:metabolism
chemical_list: D015415:Biomarkers; D015820:Cadherins; D009363:Neoplasm Proteins; C434327:PBLD protein, human; D011506:Proteins; D016601:RNA-Binding Proteins; C403447:STRAP protein, human; D016212:Transforming Growth Factor beta