Epigenetic reprogramming of XXXX cells with oocyte extracts.

@entity5 @entity7547 @entity19 @entity0
BACKGROUND: @entity0 is a disease characterised by both genetic and epigenetic alterations. Epigenetic silencing of @entity5 suppressor genes is an early event in @entity0 and reversion of gene silencing by epigenetic reprogramming can provide clues to the mechanisms responsible for @entity5 initiation and progression. In this study we apply the reprogramming capacity of oocytes to @entity5 cells in order to study breast oncogenesis. RESULTS: We show that @entity0 cells can be directly reprogrammed by amphibian oocyte extracts. The reprogramming effect, after six hours of treatment, in the absence of DNA replication, includes DNA demethylation and removal of repressive histone marks at the promoters of @entity5 suppressor genes; also, expression of the silenced genes is re-activated in response to treatment. This activity is specific to oocytes as it is not elicited by extracts from ovulated eggs, and is present at very limited levels in extracts from @entity19 embryonic stem cells. Epigenetic reprogramming in oocyte extracts results in @entity5 cell growth under anchorage independent conditions and a @entity5 growth in @entity19 xenografts. CONCLUSIONS: This study presents a new method to investigate @entity5 reversion by epigenetic reprogramming. After testing extracts from different sources, we found that @entity7547 oocyte extracts possess superior reprogramming ability, which reverses epigenetic silencing of @entity5 suppressor genes and tumorigenicity of @entity0 cells in a @entity19 xenograft model. Therefore this system can be extremely valuable for dissecting the mechanisms involved in @entity5 suppressor gene silencing and identifying molecular activities capable of arresting @entity5 growth. These applications can ultimately shed light on the contribution of epigenetic alterations in @entity0 and advance the development of epigenetic therapies.
