THE MAS PROTOONCOGENE IS IMPRINTED IN HUMAN BREAST-TISSUE

The human MAS proto-oncogene is situated at 6q25.3-q26, a region that is homologous to mouse chromosome 17 where two parentally imprinted ge nes (Mas and Igf2r) have previously been identified. We investigated t he imprinting status of MAS in adult lesions to establish the imprinti ng status of this gene in humans, as certain imprinted genes are known to have altered imprinting phenotypes in cancer. Of 14 breast samples demonstrating a MAS RT-PCR product, 4 were informative for a polymorp hic marker. In all 4 cases, expression of the MAS gene was found to be mono-allelic, indicating the presence of a functional imprint at this locus in human breast tissue. (C) 1997 Academic Press.