[The reversion of multidrug resistance in tumour cell line MCF-7/Adr by ribozyme].
OBJECTIVE
To construct a specific hammerhead ribozyme possessing catalytic activity that cleaves the mdr1 mRNA for reversing the resistant phenotype in tumour cell line.


METHODS
A DNA sequence encoding the ribozyme gene was incorporated into a eukaryotic expression vector (pH beta Apr-1 neu) and transfected into the human breast carcinoma cell line MCF-7/Adr, which is resistant to adriamycin and expresses the MDR phenotype.


RESULTS
The ribozyme was stably expressed in the cell line, and decreased the level of mdr1 mRNA expression by 83.5%. The ribozyme inhibited the formation of P-glycoprotein and reduced the cell's resistance to adriamycin.


CONCLUSIONS
The resistant cells were 1,000-fold more resistant than the parental cell line (MCF-7), whereas those cell clones that showed ribozyme expression were only 6-fold more resistant than the parental cell line.
Department of Cancer Second Hospital First Military Medical University, Guang Zhou.
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Y
Yuan
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Zhang
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Zhou
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000096:biosynthesis; D000903:Antibiotics, Antineoplastic / Q000494:pharmacology*; D001943:Breast Neoplasms / Q000473:pathology*; D004317:Doxorubicin / Q000494:pharmacology*; D018432:Drug Resistance, Multiple / Q000235:genetics*; D019008:Drug Resistance, Neoplasm / Q000235:genetics*; D005260:Female; D019450:Genes, MDR; D006801:Humans; D010641:Phenotype; D016337:RNA, Catalytic / Q000096:biosynthesis*; D012333:RNA, Messenger / Q000096:biosynthesis; D014162:Transfection; D014407:Tumor Cells, Cultured / Q000378:metabolism
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000903:Antibiotics, Antineoplastic; D016337:RNA, Catalytic; D012333:RNA, Messenger; D004317:Doxorubicin