title: Proteomic identification of overexpressed adenomatous polyposis coli and cyclin B3 during endoderm differentiation from human embryonic stem cells.
abstract: OBJECTIVE
  This study was aimed to investigate important proteins associated with endoderm differentiation by pancreatic derivation protocol from human embryonic stem cells (hESCs).
  
  
  METHODS
  Comparative proteomic analysis of endoderm cells differentiated from hESCs by activin A and low serum was performed. Proteins with altered expression levels during endoderm differentiation were investigated by 2-dimensional gel electrophoresis (2-DE) with mass spectrometric analysis.
  
  
  RESULTS
  Thirty-four protein spots with significantly changed intensities were identified. These were functionally annotated based on gene ontology. The messenger RNA expression levels of 5 genes, APC, CCNB3, HSPA9, CCT2, and YWHAE, were correlated with 2-DE analysis. We further validated the protein expression levels of adenomatous polyposis coli (APC) and cyclin B3 (CCNB3) by using Western blot analysis and immunocytochemistry. They are involved in the regulation of cell cycle, thus, cyclins and cyclin-dependent kinases, which regulate the cell cycle, were examined. Cyclin A1, cyclin D2, and cyclin E2 were upregulated, and other cyclins and cyclin-dependent kinases were downregulated in endoderm cells.
  
  
  CONCLUSIONS
  The increase in expression of APC and CCNB3 suggests that these proteins will be important markers for identifying endoderm cells differentiated from hESCs, and they can play important roles in the differentiation of endoderm cells from hESCs or in human endoderm development for pancreas.
authors.affiliation: Department of Physiology, School of Medicine, CHA University, Seongnam, Gyeonggi, Republic of Korea. leedh@cha.ac.kr
authors.forename: Dong Hyeon
authors.initials: DH
authors.lastname: Lee
authors.forename: Young Geon
authors.initials: YG
authors.lastname: Ji
authors.forename: Hyung Min
authors.initials: HM
authors.lastname: Chung
authors.forename: Jung Jae
authors.initials: JJ
authors.lastname: Ko
authors.forename: Soo-Kyung
authors.initials: SK
authors.lastname: Kim
mesh_terms: D028341:Activins / Q000378:metabolism; D025601:Adenomatous Polyposis Coli Protein / Q000235:genetics / Q000378:metabolism*; D015153:Blotting, Western; D002454:Cell Differentiation; D002460:Cell Line; D019926:Cyclin B / Q000235:genetics / Q000378:metabolism*; D015180:Electrophoresis, Gel, Two-Dimensional; D053595:Embryonic Stem Cells / Q000378:metabolism*; D004707:Endoderm / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D007150:Immunohistochemistry; D010179:Pancreas / Q000378:metabolism*; D010449:Peptide Mapping; D040901:Proteomics / Q000379:methods; D012333:RNA, Messenger / Q000378:metabolism; D015203:Reproducibility of Results; D020133:Reverse Transcriptase Polymerase Chain Reaction; D044967:Serum / Q000378:metabolism; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D015854:Up-Regulation
chemical_list: C555337:APC protein, human; D025601:Adenomatous Polyposis Coli Protein; C503694:CCNB3 protein, human; D019926:Cyclin B; D012333:RNA, Messenger; C422405:activin A; D028341:Activins