Extrachromosomal amplification of the epidermal growth factor receptor gene in a human colon carcinoma cell line

G. Dolf, R. E. Meyn, D. Curley, N. Prather, M. D. Story, B. M. Boman, M. J. Siciliano, R. R. Hewitt

Research output: Contribution to journalArticle

31 Scopus citations


In situ hybridization, using a biotinylated cDNA probe for the epidermal growth factor receptor EGFR gene, indicates that the amplified EGFR genes in the colon tumor cell line, DiFi, are localized in many small double minute chromosomes (dmin) of varying size and visibility. Analysis of the electrophoretic mobility of γ‐irradiated DNA from DiFi by pulsed‐field gel electrophoresis and Southern blot hybridization using EGFR probe, indicates that the amplified EGFR in DiFi exists in extrachromosomal, covalently closed circular episomes, presumably equivalent to dmin. Two major and one minor species were observed which had estimated sizes of 650, 1,300, and 2,000 kb, respectively. The DiFi cell line appears to represent a unique case of extrachromosomal EGFR gene amplification in human cells.

Original languageEnglish (US)
Pages (from-to)48-54
Number of pages7
JournalGenes, Chromosomes and Cancer
Issue number1
StatePublished - Jan 1991


ASJC Scopus subject areas

  • Genetics
  • Cancer Research

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