title: Differential expression of the epithelial-mesenchymal transition regulators snail, SIP1, and twist in gastric cancer.
abstract: Epithelial-mesenchymal transition (EMT) involving down-regulation of E-cadherin is thought to play a fundamental role during early steps of invasion and metastasis of carcinoma cells. The aim of our study was to elucidate the role of EMT regulators Snail, SIP1 (both are direct repressors of E-cadherin), and Twist (an activator of N-cadherin during Drosophila embryogenesis), in primary human gastric cancers. Expression of Snail, SIP1, and Twist was analyzed in 48 gastric carcinomas by real-time quantitative RT-PCR in paraffin-embedded and formalin-fixed tissues. The changes of expression levels of these genes in malignant tissues compared to matched non-tumorous tissues were correlated with the expression of E- and N-cadherin. From 28 diffuse-type gastric carcinomas analyzed reduced E-cadherin expression was detected in 11 (39%) cases compared to non-tumorous tissues. Up-regulated Snail could be found in 6 cases with reduced or negative E-cadherin expression. However, there was no correlation to increased SIP1 expression. Interestingly, we could detect abnormal expression of N-cadherin mRNA in 6 cases, which was correlated with Twist overexpression in 4 cases. From 20 intestinal-type gastric cancer samples reduced E-cadherin expression was found in 12 (60%) cases, which was correlated to up-regulation of SIP1, since 10 of these 12 cases showed elevated mRNA levels, whereas Snail, Twist, and N-cadherin were not up-regulated. We present the first study investigating the role of EMT regulators in human gastric cancer and provide evidence that an increase in Snail mRNA expression is associated with down-regulation of E-cadherin in diffuse-type gastric cancer. We detected abnormally positive or increased N-cadherin mRNA levels in the same tumors, probably due to overexpression of Twist. SIP1 overexpression could not be linked to down-regulated E-cadherin in diffuse-type tumors, but was found to be involved in the pathogenesis of intestinal-type gastric carcinoma. We conclude that EMT regulators play different roles in gastric carcinogenesis depending on the histological subtype.
authors.affiliation: Klinikum rechts der Isar, Institut für Pathologie, Technische Universität München, Germany.
authors.forename: Erika
authors.initials: E
authors.lastname: Rosivatz
authors.forename: Ingrid
authors.initials: I
authors.lastname: Becker
authors.forename: Katja
authors.initials: K
authors.lastname: Specht
authors.forename: Elena
authors.initials: E
authors.lastname: Fricke
authors.forename: Birgit
authors.initials: B
authors.lastname: Luber
authors.forename: Raymonde
authors.initials: R
authors.lastname: Busch
authors.forename: Heinz
authors.initials: H
authors.lastname: Höfler
authors.forename: Karl-Friedrich
authors.initials: KF
authors.lastname: Becker
mesh_terms: D015820:Cadherins / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D002277:Carcinoma / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000096:biosynthesis* / Q000235:genetics; D004848:Epithelium / Q000196:embryology; D015972:Gene Expression Regulation, Neoplastic; D018398:Homeodomain Proteins / Q000096:biosynthesis* / Q000235:genetics; D006801:Humans; D007150:Immunohistochemistry; D008648:Mesoderm / Q000502:physiology; D008954:Models, Biological; D009154:Mutation; D009687:Nuclear Proteins; D012334:RNA, Neoplasm / Q000096:biosynthesis; D012097:Repressor Proteins / Q000096:biosynthesis* / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D000071250:Snail Family Transcription Factors; D013274:Stomach Neoplasms / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000096:biosynthesis* / Q000235:genetics; D051879:Twist-Related Protein 1; D000074165:Zinc Finger E-box Binding Homeobox 2
chemical_list: D015820:Cadherins; D004268:DNA-Binding Proteins; D018398:Homeodomain Proteins; D009687:Nuclear Proteins; D012334:RNA, Neoplasm; D012097:Repressor Proteins; D000071250:Snail Family Transcription Factors; C103173:TWIST1 protein, human; D014157:Transcription Factors; D051879:Twist-Related Protein 1; C492363:ZEB2 protein, human; D000074165:Zinc Finger E-box Binding Homeobox 2; C000604451:sna protein, Drosophila