title: Genome-wide expression profile of sporadic gastric cancers with microsatellite instability.
abstract: Gastric cancers with mismatch repair (MMR) inactivation are characterised by microsatellite instability (MSI). In this study, the transcriptional profile of 38 gastric cancers with and without MSI was analysed. Unsupervised analysis showed that the immune and apoptotic gene networks efficiently discriminated these two cancer types. Hierarchical clustering analysis revealed numerous gene expression changes associated with the MSI phenotype. Amongst these, the p53-responsive genes maspin and 14-3-3 sigma were significantly more expressed in tumours with than without MSI. A tight immunosurveillance coupled with a functional p53 gene response is consistent with the better prognosis of MSI cancers. Frequent silencing of MLH1 and downregulation of MMR target genes, such as MRE11 and MBD4, characterised MSI tumours. The downregulation of SMUG1 was also a typical feature of these tumours. The DNA repair gene expression profile of gastric cancer with MSI is of relevance for therapy response.
authors.affiliation: Department of Environment and Primary Prevention, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy.
authors.forename: Mariarosaria
authors.initials: M
authors.lastname: D'Errico
authors.forename: Emanuele
authors.initials: E
authors.lastname: de Rinaldis
authors.forename: Monica F
authors.initials: MF
authors.lastname: Blasi
authors.forename: Valentina
authors.initials: V
authors.lastname: Viti
authors.forename: Mario
authors.initials: M
authors.lastname: Falchetti
authors.forename: Angelo
authors.initials: A
authors.lastname: Calcagnile
authors.forename: Francesco
authors.initials: F
authors.lastname: Sera
authors.forename: Calogero
authors.initials: C
authors.lastname: Saieva
authors.forename: Laura
authors.initials: L
authors.lastname: Ottini
authors.forename: Domenico
authors.initials: D
authors.lastname: Palli
authors.forename: Fabio
authors.initials: F
authors.lastname: Palombo
authors.forename: Alessandro
authors.initials: A
authors.lastname: Giuliani
authors.forename: Eugenia
authors.initials: E
authors.lastname: Dogliotti
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D053843:DNA Mismatch Repair / Q000235:genetics*; D015536:Down-Regulation / Q000235:genetics; D005260:Female; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics; D016158:Genes, p53 / Q000235:genetics*; D006801:Humans; D008297:Male; D053842:Microsatellite Instability; D008875:Middle Aged; D020411:Oligonucleotide Array Sequence Analysis; D010641:Phenotype; D011379:Prognosis; D011401:Promoter Regions, Genetic / Q000235:genetics; D013274:Stomach Neoplasms / Q000235:genetics*