X Chromosome Inactivation and Breast Cancer: Epigenetic Alteration in Tumor Initiation and Progression

摘要

We tested whether reactivation of the inactive X chromosome in the mouse mammary gland contributes to tumorigenesis in vivo and whether that reactivation of the inactive X can cooperate with the MYC oncogene in tumor progression. We found no evidence for a role of reactivation of the inactive X in tumor initiation or progression. We also examined whether the inactive X was reactivated in a number of different mouse breast cancers and found not evidence to support reactivation. Finally, these studies directly lead to an examination of whether the BRCA1 promotes breast cancer by affecting the function of Xist RNA during X-inactivation, and found that Xist RNA and X- inactivation are unaffected in BRCA1 mutant cells and cancers.