Amplification of DNA sequences in human multidrug-resistant KB carcinoma cells

A. T. Fojo, J. Whang-Peng, M. M. Gottesman, I. Pastan

Research output: Contribution to journalArticlepeer-review

138 Citations (Scopus)


Four KB carcinoma cell lines selected independently for resistance to either colchicine, adriamycin, or vinblastine were studied. All cell lines showed high levels of resistance to the selecting drug and cross-resistance to the other drugs and to actinomycin D. Double-minute chromosomes could be identified on chromosomal spreads of these multidrug-resistant KB cell lines. Amplification of specific DNA sequences was demonstrated by using the technique of in-gel renaturation. All the cell lines share common amplified sequences. There are also amplified sequences that are specific for each cell line. A revertant cell line that has reacquired drug sensitivity has lost its amplified sequences. Specific probes obtained by cloning amplified sequences from the cell line selected in vinblastine recognize amplified sequences in all the resistant lines. The presence of common amplified sequences in these cell lines is strong evidence for the importance of these regions in multiple drug resistance.

Original languageEnglish
Pages (from-to)7661-7665
Number of pages5
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number22
Publication statusPublished - Jan 1 1985
Externally publishedYes

ASJC Scopus subject areas

  • General


Dive into the research topics of 'Amplification of DNA sequences in human multidrug-resistant KB carcinoma cells'. Together they form a unique fingerprint.

Cite this