title: Proteomic analysis of CD44(+) and CD44(-) gastric cancer cells.
abstract: CD44 is a cell surface protein and it is widely used as a cancer stem cell marker in various cancer types including gastric cancer. We conducted proteomic analysis in CD44(+) and CD44(-) gastric cancer cells to understand characteristics of CD44(+) and CD44(-) cells. In the present study, we sorted cells from the gastric cancer cell line MKN45 according to CD44 expression to separate out CD44(+) and CD44(-) cells. And we conducted RT-PCR to identify mRNA expression of cancer stem cell markers in CD44(+) and CD44(-) cells. Cancer stem cell markers showed upregulated expression in CD44(+) cells. Next, we performed two-dimensional electrophoresis analysis to determine the differential expression pattern of proteins in each group; control, CD44(+), and CD44(-) MKN45 cells. We found a total of 113 spots that varied in expression between CD44(+) and CD44(-) cells, and subjected 20 of those protein spots to MALDI-MS. We selected the three proteins (HSPA8; heat shock cognate 71 kDa protein isoform 1, ezrin, α-enolase) upregulated in CD44(+) cells than CD44(-) cells and one protein (prohibitin) showed increased expression in CD44(-) cells. We validated the protein expression levels of four selected proteins by Western blot. We suggest that our study could be a helpful background to study CD44(+) cancer stem-like cells and differences between CD44(+) and CD44(-) cells in gastric cancer.
authors: Department of Internal Medicine, Institute of Gastroenterology, Yonsei University College of Medicine, 134 Shinchon-Dong, Seodaemun-Ku, Seoul, 120-752, Korea.
authors: Dayeon
authors: D
authors: Yu
authors: Hyun-Soo
authors: HS
authors: Shin
authors: Go
authors: G
authors: Choi
authors: Yong Chan
authors: YC
authors: Lee
mesh_terms: D014408:Biomarkers, Tumor / Q000378:metabolism; D002469:Cell Separation; D003598:Cytoskeletal Proteins / Q000378:metabolism; D015180:Electrophoresis, Gel, Two-Dimensional; D020869:Gene Expression Profiling; D050883:HSC70 Heat-Shock Proteins / Q000378:metabolism; D006801:Humans; D018960:Hyaluronan Receptors / Q000378:metabolism*; D014411:Neoplastic Stem Cells / Q000378:metabolism; D010751:Phosphopyruvate Hydratase / Q000378:metabolism; D011506:Proteins / Q000032:analysis* / Q000235:genetics / Q000378:metabolism; D040901:Proteomics / Q000379:methods; D015203:Reproducibility of Results; D013274:Stomach Neoplasms / Q000378:metabolism* / Q000473:pathology; D015854:Up-Regulation; D000099149:Ezrin
chemical_list: D014408:Biomarkers, Tumor; D003598:Cytoskeletal Proteins; D050883:HSC70 Heat-Shock Proteins; D018960:Hyaluronan Receptors; D010751:Phosphopyruvate Hydratase; D011506:Proteins; D000099149:Ezrin; C497483:CD44 protein, human; C494371:HSPA8 protein, human