The disappearing Barr body in breast and ovarian cancers
Department of Cell Biology
Medical Subject Headings
Breast Neoplasms; Chromosomes, Human, X; Female; Genes, BRCA1; Heterochromatin; Humans; Ovarian Neoplasms; Sex Chromatin
Interest has recently reawakened in whether loss of the heterochromatic X chromosome (Barr body) is prevalent in certain breast and ovarian cancers, and new insights into the mechanisms involved have emerged. Mitotic segregation errors commonly explain the loss of the inactive X chromosome (Xi), but compromise of Xi heterochromatin in some cancers may signal broader deficits of nuclear heterochromatin. The debated link between BRCA1 and Xi might reflect a general relationship between BRCA1 and heterochromatin, which could connect BRCA1 to both epigenetic and genetic instability. We suggest that heterochromatic instability is a common but largely unexplored mechanism, leading to widespread genomic misregulation and the evolution of some cancers.
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Citation: Nat Rev Cancer. 2007 Aug;7(8):628-33. Epub 2007 Jul 5. Link to article on publisher's site