Co-amplification and over-expression of two mdr genes in a multidrug-resistant human colon carcinoma cell line.
The human P-glycoprotein gene family contains the mdr1 and the mdr3 gene. The mdr1 P-glycoprotein is over-expressed in multidrug resistant (MDR) tumor cells and is believed to play a role in the elimination of certain cytotoxic drugs used in the chemotherapy of cancer. The mdr3 gene has not been found to be amplified or over-expressed in MDR cells. In this study, gene-specific mdr gene probes were developed for the detection of the gene and the total mRNA level. Southern and Northern hybridization analyses showed that the mdr genes and the mRNA levels were increased 30--40-fold in a MDR human colon cancer cell line. In addition, this MDR cell line had an altered growth rate and morphology and detectable double minute chromosomes.
Department of Biochemistry, Chang Gung Medical College, Taoyuan, Taiwan, Republic of China.
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Chao
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Ma
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Lin-Chao
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D002460:Cell Line; D002471:Cell Transformation, Neoplastic / Q000187:drug effects; D003110:Colonic Neoplasms / Q000235:genetics* / Q000473:pathology; D015342:DNA Probes; D004317:Doxorubicin / Q000494:pharmacology; D004351:Drug Resistance / Q000235:genetics; D005784:Gene Amplification; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D008562:Membrane Glycoproteins / Q000235:genetics*; D009363:Neoplasm Proteins / Q000235:genetics*
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D015342:DNA Probes; D008562:Membrane Glycoproteins; D009363:Neoplasm Proteins; D004317:Doxorubicin