Breakpoint Junction of Interstitial Homozygous Deletion at Chromosome 2q33 in a Small Cell Lung Carcinoma

Abstract

We have characterized the breakpoint junction of the homozygous deletion at chromosome 2q33 in a small cell lung carcinoma cell line. Cloning and sequencing of the genomic regions surrounding the breakpoint junction of the deletion revealed that the homozygous deletion was caused by a simple interstitial deletion of a 220-kb segment. An AT-dinucleotide of contributing germline sequences was overlapped at the junction. Since there were one or two nucleotide overlaps of germline sequences at breakpoint junctions in all four cases of interstitial deletions analyzed to date, this may reflect a common mechanism underlying the occurrence of chromosomal interstitial deletion.