title: Identification of differentially expressed genes in classical and atypical multidrug-resistant gastric carcinoma cells.
abstract: The phenomenon of multidrug resistance (MDR) in human cancers is the major cause of failure of chemotherapy. To better understand the molecular events associated with the development of different types of MDR, a classical MDR P-glycoprotein expressing gastric carcinoma cell line and an atypical MDR P-glycoprotein-negative variant were analyzed by cDNA array hybridization. Of 588 cDNAs spotted on the array, a total of 9 genes showed differences in mRNA expressions. An enhanced expression level of 3 genes could be detected in both different MDR models (HLH, IR21, CCT5, Tx P-1), 4 genes were overexpressed solely in classical MDR cells (Hsp27, Rcl, aldehyde dehydrogenase 1, vimentin), whereas the expression of one gene was increased in atypical MDR cells (ProTa). Furthermore, the mRNA expressions of 3 genes were down-regulated in atypical MDR cells (Hsp27, vimentin, JNK2), whereas a decrease in mRNA expression in classical MDR cells could be determined for none of them. These differences were confirmed by a semiquantitative RT-PCR approach. Further characterization of these factors may provide more insight into the biology and development of different types of MDR in human gastric carcinomas. Moreover, these genes may be potential candidate factors for the diagnostics and/or prognosis of clinical drug resistance.
authors.affiliation: Institute of Pathology, Charité Campus Mitte, Humboldt University Berlin, Schumannstr. 20/21, D-10117 Berlin, Germany.
authors.forename: Antje
authors.initials: A
authors.lastname: Ludwig
authors.forename: Manfred
authors.initials: M
authors.lastname: Dietel
authors.forename: Hermann
authors.initials: H
authors.lastname: Lage
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000096:biosynthesis; D018432:Drug Resistance, Multiple / Q000235:genetics*; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D020411:Oligonucleotide Array Sequence Analysis; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013274:Stomach Neoplasms / Q000188:drug therapy* / Q000235:genetics* / Q000378:metabolism; D014407:Tumor Cells, Cultured
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D012333:RNA, Messenger