title: The expression of the molecular chaperone calnexin is decreased in cancer cells grown as colonies compared to monolayer.
abstract: Differential display was used to identify genes which were differentially expressed when HT-29 human colon adenocarcinoma cells were grown as monolayers attached to plastic or as colonies in soft agarose. One of the gel bands differentially displayed corresponded to a 171 bp fragment that showed 99% identity with a sequence of mRNA for human calnexin. The decrease in calnexin gene expression by HT-29 cells growing as colonies in soft agarose was confirmed by reverse transcriptase-PCR (RT-PCR) using calnexin-specific primers. We also used RT-PCR to show that the expression of calnexin was decreased in HT-29 cells and MCF-7 human breast adenocarcinoma cells growing in suspension in poly(hydroxyethyl methacrylate)-coated wells compared to cells growing as monolayers. The results suggest that there is a signal for the up-regulation of calnexin expression when cells contact a substrate which allows cell adhesion.
authors.affiliation: Arizona Cancer Center, University of Arizona, Tucson 85724-5024, USA. lcyeates@azcc.arizona.edu
authors.forename: L C
authors.initials: LC
authors.lastname: Yeates
authors.forename: G
authors.initials: G
authors.lastname: Powis
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism* / Q000473:pathology; D001483:Base Sequence; D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology; D002135:Calcium-Binding Proteins / Q000096:biosynthesis* / Q000235:genetics; D037281:Calnexin; D018929:Cell Culture Techniques / Q000379:methods; D003001:Cloning, Molecular; D003110:Colonic Neoplasms / Q000378:metabolism* / Q000473:pathology; D018076:DNA, Complementary / Q000032:analysis; D006801:Humans; D018832:Molecular Chaperones / Q000096:biosynthesis* / Q000235:genetics; D008969:Molecular Sequence Data; D011102:Polyhydroxyethyl Methacrylate; D016133:Polymerase Chain Reaction; D014407:Tumor Cells, Cultured; D014410:Tumor Stem Cell Assay
chemical_list: D002135:Calcium-Binding Proteins; D018076:DNA, Complementary; D018832:Molecular Chaperones; D037281:Calnexin; D011102:Polyhydroxyethyl Methacrylate