title: Expression changes of cell-cell adhesion-related genes in colorectal tumors.
abstract: Epithelial tissues achieve a highly organized structure due to cell-cell junction complexes. Carcinogenesis is accompanied by changes in cell interactions and tissue morphology, which appear in the early stages of benign tumors and progress along with invasive potential. The aim of the present study was to analyze the changes in expression levels of genes encoding intercellular junction proteins that have been previously identified to be differentially expressed in colorectal tumors compared with normal mucosa samples (fold change, >2.5) in genome-wide expression profiling. The expression of 20 selected genes was assessed using quantitative reverse transcription polymerase chain reaction in 26 colorectal cancer, 42 adenoma and 24 normal mucosa samples. Between these tissue types, differences were observed in the mRNA levels of genes encoding adherens junction proteins (upregulation ofCDH3andCDH11, and downregulation ofCDH19andPTPRF), tight junction proteins (upregulation ofCLDN1andCLDN2, and downregulation ofCLDN5,CLDN8,CLDN23,CLDN15,JAM2andCGN) and desmosomes (upregulation ofDSC3andDSG3, and downregulation ofDSC2), in addition to a decrease in the expression of certain other genes involved in intercellular connections:PCDHB14,PCDH7,MUPCDHandNEO1. The differences between tissue types were statistically significant, and separate clustering of normal adenoma and carcinoma samples was observed in a hierarchical clustering analysis. These results indicate that the morphological changes in neoplastic colon tissue that occur during the 'adenoma-carcinoma sequence' are accompanied by specific changes in the expression of multiple genes encoding the majority of cell-cell junction complexes. The particular differential expression patterns appear to be consistent among patients with cancer and adenoma, in addition to normal mucosa samples.
authors.affiliation: Department of Molecular and Translational Oncology, Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, Warsaw 02-781, Poland.
authors.forename: Mateusz
authors.initials: M
authors.lastname: Bujko
authors.affiliation: Department of Molecular and Translational Oncology, Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, Warsaw 02-781, Poland.
authors.forename: Paulina
authors.initials: P
authors.lastname: Kober
authors.affiliation: Department of Genetics, Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, Warsaw 02-781, Poland.
authors.forename: Michal
authors.initials: M
authors.lastname: Mikula
authors.affiliation: Department of Pathology, Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, Warsaw 02-781, Poland.
authors.forename: Marcin
authors.initials: M
authors.lastname: Ligaj
authors.affiliation: Department of Genetics, Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, Warsaw 02-781, Poland.
authors.forename: Jerzy
authors.initials: J
authors.lastname: Ostrowski
authors.affiliation: Department of Molecular and Translational Oncology, Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, Warsaw 02-781, Poland.
authors.forename: Janusz Aleksander
authors.initials: JA
authors.lastname: Siedlecki
keywords: cell-cell adhesion; colorectal adenoma; colorectal cancer; gene expression