title: Chromosome 22 array-CGH profiling of breast cancer delimited minimal common regions of genomic imbalances and revealed frequent intra-tumoral genetic heterogeneity.
abstract: Breast cancer is a common malignancy and the second most frequent cause of death among women. Our aim was to perform DNA copy number profiling of 22q in breast tumors using a methodology which is superior, as compared to the ones applied previously. We studied 83 biopsies from 63 tumors obtained from 60 female patients. A general conclusion is that multiple distinct patterns of genetic aberrations were observed, which included deletion(s) and/or gain(s), ranging in size from affecting the whole chromosome to only a few hundred kb. Overall, the analysis revealed genomic imbalances of 22q in 22% (14 out of 63) of tumors. The predominant profile (11%) was monosomy 22. The smallest identified candidate region, in the vicinity of telomere of 22q, encompasses approximately 220 kb and was involved in all but one of the tumors with aberrations on chromosome 22. This segment is dense in genes and contains 11 confirmed and one predicted gene. The availability of multiple biopsies from a single tumor provides an excellent opportunity for analysis of possible intra-tumor differences in genetic profiles. In 15 tumors we had access to two or three biopsies derived from the same lesion and these were studied independently. Four out of 15 (26.6%) tumors displayed indications of clonal intra-tumor genotypic differences, which should be viewed as a high number, considering that we studied in detail only a single human chromosome. Our results open up several avenues for continued genetic research of breast cancer.
authors.affiliation: Department of Genetics and Pathology, Rudbeck Laboratory, Uppsala University, 75185 Uppsala, Sweden. magdalena.benetkiewicz@curie.fr
authors.forename: Magdalena
authors.initials: M
authors.lastname: Benetkiewicz
authors.forename: Arkadiusz
authors.initials: A
authors.lastname: Piotrowski
authors.forename: Teresita
authors.initials: T
authors.lastname: Díaz De Ståhl
authors.forename: Michal
authors.initials: M
authors.lastname: Jankowski
authors.forename: Dariusz
authors.initials: D
authors.lastname: Bala
authors.forename: Jacek
authors.initials: J
authors.lastname: Hoffman
authors.forename: Ewa
authors.initials: E
authors.lastname: Srutek
authors.forename: Ryszard
authors.initials: R
authors.lastname: Laskowski
authors.forename: Wojciech
authors.initials: W
authors.lastname: Zegarski
authors.forename: Jan P
authors.initials: JP
authors.lastname: Dumanski
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000235:genetics* / Q000473:pathology; D043171:Chromosomal Instability; D002892:Chromosomes, Human, Pair 22 / Q000235:genetics*; D005260:Female; D018628:Gene Dosage; D052138:Genes, Neoplasm; D018740:Genetic Heterogeneity; D006801:Humans; D008875:Middle Aged; D009693:Nucleic Acid Hybridization; D020411:Oligonucleotide Array Sequence Analysis; D017384:Sequence Deletion; D014407:Tumor Cells, Cultured