title: H19 gene overexpression in atypical multidrug-resistant cells associated with expression of a 95-kilodalton membrane glycoprotein.
abstract: The multidrug resistance phenotype of human breast carcinoma MCF-7/AdrVp cells is characterized by overexpression of a 95-kilodalton membrane glycoprotein (p95), accompanied by a marked reduction in intracellular anthracycline accumulation, without overexpression of P-glycoprotein or the multidrug resistance protein. We discovered that the mRNA of the H19 gene is overexpressed in MCF-7/AdrVp cells relative to parental MCF-7 cells or drug-sensitive MCF-7/AdrVp revertant cells. H19 is an imprinted gene with an important role in fetal differentiation, as well as a postulated function as a tumor suppressor gene. Another p95-overexpressing multidrug-resistant cell line, human lung carcinoma NCI-H1688, also displays high levels of H19 mRNA. In contrast, several multidrug-resistant cell lines that overexpress P-glycoprotein or the multidrug resistance protein do not have higher levels of H19 mRNA than their drug-sensitive counterparts. This is the first report of H19 gene overexpression accompanying any form of drug resistance. The association of H19 and p95 gene expression in drug resistance warrants further study.
authors.affiliation: University of Maryland Cancer Center, University of Maryland School of Medicine, Baltimore 21201, USA.
authors.forename: L A
authors.initials: LA
authors.lastname: Doyle
authors.forename: W
authors.initials: W
authors.lastname: Yang
authors.forename: A K
authors.initials: AK
authors.lastname: Rishi
authors.forename: Y
authors.initials: Y
authors.lastname: Gao
authors.forename: D D
authors.initials: DD
authors.lastname: Ross
mesh_terms: D001483:Base Sequence; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000235:genetics* / Q000378:metabolism; D003001:Cloning, Molecular; D015342:DNA Probes; D004273:DNA, Neoplasm / Q000235:genetics; D018432:Drug Resistance, Multiple / Q000235:genetics*; D015870:Gene Expression; D006801:Humans; D008562:Membrane Glycoproteins / Q000096:biosynthesis*; D008969:Molecular Sequence Data; D009124:Muscle Proteins / Q000096:biosynthesis* / Q000235:genetics*; D009363:Neoplasm Proteins / Q000096:biosynthesis*; D062085:RNA, Long Noncoding; D022661:RNA, Untranslated; D014407:Tumor Cells, Cultured
chemical_list: D015342:DNA Probes; D004273:DNA, Neoplasm; C094335:H19 long non-coding RNA; D008562:Membrane Glycoproteins; D009124:Muscle Proteins; D009363:Neoplasm Proteins; D062085:RNA, Long Noncoding; D022661:RNA, Untranslated