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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1999-3-4
pubmed:abstractText
The tumor suppressor gene p16ink4a is homozygously deleted in numerous T as well as in some B lineage acute lymphoblastic leukemia (ALL). We therefore analyzed the clinical and biological implications of this feature by studying p16ink4a expression in 58 cases of childhood ALL. mRNA and protein were significantly correlated and both appeared more highly expressed in B than in T lineage ALLs: 13 out of the 15 T cell ALLs did not show any p16ink4a expression. The main result of this study is the strong prognostic value of p16ink4a expression. When stratifying the patients in three groups according to p16ink4a expression, we observed in univariate analysis: (1) the shortest disease-free survival for patients presenting a high p16ink4a level; (2) contrasting with the good prognosis in the group of patients expressing p16ink4a at low level; (3) while cases without any expression of the inhibitor were associated with a medium course of the disease (P=0.0165). This prognostic value was confirmed by the multivariate analysis showing therapeutic regimen and p16ink4a protein expression as the only variables retained in the model. A specific metabolic profile related to cellular survival and proliferation was observed in each of the three p16ink4a expression groups. Among the cell cycle-related proteins we analyzed, only p21waf1 bcl-2 and CDK4 were significantly and positively correlated to p16ink4a. Furthermore, CDK6 was also strongly expressed in the group of cases with high p16ink4a level. An enhancement of p16ink4a, p21waf1 and bcl-2 was previously described in prolonged cellular survival, while aging cells showed a decrease in CDK4 expression. The concomitant high expression of the oncogenic protein CDK4 (and of CDK6), we observed, may amplify the leukemic advantage of prolonged lifespan blast cells by favoring cell progression through G1 phase. These data suggest that at least two mechanisms may be associated in the oncogenesis of very aggressive ALLs, ie deregulation of cell multiplication and prolonged blast lifespan.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0887-6924
pubmed:author
pubmed:issnType
Print
pubmed:volume
13
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
181-9
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Enhanced expression of p16ink4a is associated with a poor prognosis in childhood acute lymphoblastic leukemia.
pubmed:affiliation
Laboratoire de Cytologie Analytique, Université Claude Bernard, MESRT JE 1879, Lyon, France.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't