Genetic and epigenetic alterations of the cell cycle regulators and XXXX suppressor genes in @entity421 .

@entity1 @entity986 @entity5 @entity996 @entity39 @entity876 @entity421 @entity3 @entity105
PURPOSE: To analyze the genetic and epigenetic alterations affecting the @entity996 , @entity876 , @entity986 , and p21WAF1 @entity5 suppressor genes, loss of heterozygosity (LOH) at 3q and 18q, and the clinical variables of a series of Spanish @entity1 with @entity421 . These genetic changes were tested for an association with prognosis. METHODS: Peripheral blood samples and clinical data were available from 76 @entity1 with @entity421 . Paired tissue was available from 41 of them. The mutation and methylation status of @entity986 , p21WAF1, @entity876 , and @entity996 was screened as well as LOH at 3q and 18q. RESULTS: Loss of heterozygosity affecting @entity996 (37.2%), @entity876 (42.3%), and 18q (30.8%) and @entity876 mutation (39%) were frequently encountered. @entity876 mutation was associated with diagnosis at a later age. @entity996 alteration was associated with reduced survival and event-free survival. The clinical variables associated with poor prognosis were the presence of @entity3 at diagnosis (P = 0.035) or during treatment (P = 0.016) and the chondroblastic histologic subtype (P = 0.007); the response to induction chemotherapy (<90% @entity39 ) also tended to be related to poor prognosis (P = 0.08). CONCLUSIONS: @entity996 , @entity876 , and possibly other @entity5 suppressor genes located at 18q and other localizations are involved in pediatric @entity105 , together with other genetic alterations not fully understood to date. Based on these results, the presence of an altered @entity996 gene should be regarded as a poor prognostic factor for @entity421 .
