The DNA region around the c-myc gene and its amplification in human tumour cell lines.

In order to study amplicons containing the c-myc locus in human tumour cells we have analysed the region around the human c-myc gene. Using pulsed field gel electrophoresis we have constructed a 1.8 Mb map of the c-myc locus using six rare-cutting endonucleases. In addition we have cloned 130 kb of continuous DNA around the c-myc gene which includes 65 kb of 5' sequence and 65 kb of 3' sequence. The first exon of the pvt-1 gene was located 59 kb 3' of the c-myc gene. Using nine neighbouring probes, covering a region of about 395 kb around the c-myc gene, we were able to determine the extent and composition of c-myc amplicons in the HL60, NCI-N417, Colo320HSR, SkBr3 and the Sk-N-MC human tumour cell lines. Furthermore we analysed the chromosomal location of amplified c-myc DNA in NCI-N417 and SkBr3 cells. Similarities and differences between the amplified DNA in the different cell lines are discussed.