title: Molecular basis of the differences between normal and tumor tissues of gastric cancer.
abstract: To be able to describe the differences between the normal and tumor tissues of gastric cancer at a molecular level would be essential in the study of the disease. We investigated the gene expression pattern in the two types of tissues from gastric cancer by performing expression profiling of 86 tissues on 17K complementary DNA microarrays. To select for the differentially expressed genes, class prediction algorithm was employed. For predictor selection, samples were first divided into a training (n=58), and a test set (n=28). A group of 894 genes was selected by a t-test in a training set, which was used for cross-validation in the training set and class (normal or tumor) prediction in the test set. Smaller groups of 894 genes were individually tested for their ability to correctly predict the normal or tumor samples based on gene expression pattern. The expression ratios of the 5 genes chosen from microarray data can be validated by real time RT-PCR over 6 tissue samples, resulting in a high level of correlation, individually or combined. When a representative predictor set of 92 genes was examined, pathways of 'focal adhesion' (with gene components of THBS2, PDGFD, MAPK1, COL1A2, COL6A3), 'ECM-receptor interaction' pathway (THBS2, COL1A2, COL6A3, FN1) and 'TGF-beta signaling' (THBS2, MAPK1, INHBA) represent some of the main differences between normal and tumor of gastric cancer at a molecular level.
authors.affiliation: Cancer Metastasis Research Center, Yonsei University College of Medicine, 134, Shinchon-Dong, Seodaemun-Gu, Seoul 120-752, Korea.
authors.forename: Sanghwa
authors.initials: S
authors.lastname: Yang
authors.forename: Jihye
authors.initials: J
authors.lastname: Shin
authors.forename: Kyu Hyun
authors.initials: KH
authors.lastname: Park
authors.forename: Hei-Cheul
authors.initials: HC
authors.lastname: Jeung
authors.forename: Sun Young
authors.initials: SY
authors.lastname: Rha
authors.forename: Sung Hoon
authors.initials: SH
authors.lastname: Noh
authors.forename: Woo Ick
authors.initials: WI
authors.lastname: Yang
authors.forename: Hyun Cheol
authors.initials: HC
authors.lastname: Chung
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D016000:Cluster Analysis; D005753:Gastric Mucosa / Q000378:metabolism*; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D020411:Oligonucleotide Array Sequence Analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000235:genetics; D013270:Stomach / Q000473:pathology; D013274:Stomach Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology