An enhancer-blocker associated to a matrix attachment region (MAR) insulates the chromatin domains of the human c-Myc and Pvt-1 genes

Chimeric amplicons containing the c-myc gene in HL60 cells

The major amplicon present in HL60 cells is chimeric in nature being composed of 70 kb of DNA sequence derived from the MYC locus linked to 80 kb of novel DNA sequence derived from a non contiguous region located telomeric to the c-myc gene at 8q24 (Feo et al., 1996). Here we show by fluorescence in situ hybridization (FISH) that these coamplified sequences, MCR (Myc Coamplified Region), are derived from a locus located 3-4 Mb telomeric to the c-myc gene in the q24.2-24.3 region of chromosome 8. Genomic cloning and Southern blot analysis indicate the arrangement of chimeric amplicons are in tandem arrays. Analysis of the DNA sequences at the juncture of the MYC locus and the MCR suggest tha…

The PVT-1 oncogene is a Myc protein target that is overexpressed in transformed cells

The human PVT-1 gene is located on chromosome 8 telomeric to the c-Myc gene and it is frequently involved in the translocations occurring in variant Burkitt's lymphomas and murine plasmacytomas. It has been proposed that PVT-1 regulates c-Myc gene transcription over a long distance. To get new insights into the functional relationships between the two genes, we have investigated PVT-1 and c-Myc expression in normal human tissues and in transformed cells. Our findings indicate that PVT-1 expression is restricted to a relative low number of normal tissues compared to the wide distribution of c-Myc mRNA, whereas the gene is highly expressed in many transformed cell types including neuroblastom…