Dynamics, stability and inheritance of somatic DNA methylation imprints.

Recent research highlights the role of CpG methylation in genomic imprinting, histone and chromatin modification, transcriptional regulation, and 'gene silencing' in cancer development. An unresolved issue, however, is the role of stable inheritance of factors that manage epigenetic imprints in renewing or expanding cell populations in soma. Here we propose a mathematical model of CpG methylation that is consistent with the cooperative roles of de novo and maintenance methylation.

Evaluation of pathways for progression of heterogeneous breast tumors.

To better understand the progression of heterogeneous breast cancers, four models of progession pathways have been evaluated. The models describe the progression through the grades of ductal carcinoma in situ (DCIS) 1, 2, and 3, and through the grades of invasive ductal carcinoma (IDC) 1, 2, and 3. The first three pathways, termed linear, nonlinear, and branched, describe DCIS as a progenitor of IDC, and grades of DCIS progressing into grades of IDC.