Frequent homozygous deletions of the CDKN2A locus in somatic cancer tissues

Publication date: Available online 25 April 2019Source: Mutation Research/Fundamental and Molecular Mechanisms of MutagenesisAuthor(s): Mr Abdulaziz Hamid, Ruben PetreacaAbstractHere we present and describe data on homozygous deletions (HD) of human CDKN2 A and neighboring regions on the p arm of Chromosome 9 from cancer genome sequences deposited on the online Catalogue of Somatic Mutations in Cancer (COSMIC) database. Although CDKN2 A HDs have been previously described in many cancers, this is a pan-cancer report of these aberrations with the aim to map the distribution of the breakpoints. We find that HDs of this locus have a median range of 1,255,650bps. When the deletion breakpoints were mapped on both the telomere and centromere proximal sides of CDKN2 A, most of the telomere proximal breakpoints concentrate to a narrow region of the chromosome where the gene MTAP is located. The centromere proximal breakpoints of the deletions are distributed over a wider chromosomal region. Furthermore, gene expression analysis shows that the deletions that include the CDKN2 A region also include the MTAP region and this observation is tissue independent. This analysis shows that the CDKN2 A HDs are not completely random but at least one of the breakpoints originates in a narrow region immediately telomere proximal of CDKN2 A. We propose a model to explain how CDKN2 A locus HDs may originate. Finally, we show that HD distributions for at least three other loci, RB1, SMAD...
Source: Mutation Research Fundamental and Molecular Mechanisms of Mutagenesis - Category: Cytology Source Type: research