title: Abnormal expression of Pygopus 2 correlates with a malignant phenotype in human lung cancer.
abstract: BACKGROUND
  Pygopus 2 (Pygo2) is a Pygo family member and an important component of the Wnt signaling transcriptional complex. Despite this data, no clinical studies investigating Pygo2 expression in lung cancer have yet been reported.
  
  
  METHODS
  In the present study, the expression patterns of Pygo2 were evaluated by immunochemistry in 168 patients with non-small cell lung cancer (NSCLC). We used small interfering RNA (siRNA) to specifically silence Pygo2, and investigated its effect on cell growth by an 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry analysis in human lung cancer cell lines.
  
  
  RESULTS
  Immunohistochemical analysis showed low expression of Pygo2 in normal lung tissues and increased nuclear expression in lung cancer tissues, either with or without perinuclear expression. Abnormal Pygo2 expression was associated with poor differentiation and a high Tumor (T), Node (N) and Metastases (M) stage in NSCLC patients, and correlated with poor prognosis. Using MTT assay we observed that Pygo2 downregulation inhibited cell proliferation; in addition, flow cytometry analysis showed that Pygo2 knockdown induced apoptosis and increased numbers of G1-phase cells and a reduction in S-phase cells.
  
  
  CONCLUSIONS
  We therefore conclude that abnormal Pygo2 protein expression may be a marker for advanced NSCLC. Furthermore, Pygo2 knockdown suppresses cell growth.
authors.affiliation: Department of Pathology, The First Affiliated Hospital and College of Basic Medical Sciences of China Medical University, Shenyang 110001, PR China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.forename: Qian-Ze
authors.initials: QZ
authors.lastname: Dong
authors.forename: Si
authors.initials: S
authors.lastname: Wang
authors.forename: Chang-Qing
authors.initials: CQ
authors.lastname: Fang
authors.forename: Yuan
authors.initials: Y
authors.lastname: Miao
authors.forename: Liang
authors.initials: L
authors.lastname: Wang
authors.forename: Ming-Zhu
authors.initials: MZ
authors.lastname: Li
authors.forename: En-Hua
authors.initials: EH
authors.lastname: Wang
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis*; D015153:Blotting, Western; D002289:Carcinoma, Non-Small-Cell Lung / Q000378:metabolism / Q000473:pathology*; D005434:Flow Cytometry; D055785:Gene Knockdown Techniques; D006801:Humans; D007150:Immunohistochemistry; D047908:Intracellular Signaling Peptides and Proteins / Q000032:analysis / Q000096:biosynthesis*; D008175:Lung Neoplasms / Q000378:metabolism / Q000473:pathology*; D010641:Phenotype; D034741:RNA, Small Interfering; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D014408:Biomarkers, Tumor; D047908:Intracellular Signaling Peptides and Proteins; C453401:PYGO2 protein, human; D034741:RNA, Small Interfering