title: Hypermethylation of p15/ink4b/MTS2 gene is differentially implicated among non-Hodgkin's lymphomas.
abstract: P15 (MTS2) gene is a candidate tumor suppressor gene localized adjacent to the p16 gene at 9p21. Deletions at the 9p21 region frequently affect both p16 and p15 genes, however, mutations in the coding sequence of the p15 gene have not been found in the majority of tumors analyzed, including non-Hodgkin's lymphomas. Abnormal methylation of the promoter region of p15 has been recently described as an alternative mechanism of inactivation of this gene. We analyzed 72 non-Hodgkin's lymphomas (NHL) for methylation at p15 exon 1 by PCR and Southern blot techniques using methylation-sensitive restriction enzymes. Abnormal methylation was found in eight cases (11%), most of them (three MALT, one anaplastic T cell lymphoma, one Burkitt and one follicular lymphoma) showing hypermethylation in the p16 gene also. In contrast, two pleomorphic T cell NHL showed a selective methylation at p15 gene, while the p16 gene remained unmethylated. The results show that methylation at the p15 gene is frequently associated with p16 methylation in NHL, and suggest that selective methylation of p15, although uncommon, could be a specific alteration implicated in T cell NHL.
authors.affiliation: Genetic Department, Fundacion Jimenez Diaz, Madrid, Spain.
authors.forename: B
authors.initials: B
authors.lastname: Martinez-Delgado
authors.forename: M
authors.initials: M
authors.lastname: Robledo
authors.forename: E
authors.initials: E
authors.lastname: Arranz
authors.forename: A
authors.initials: A
authors.lastname: Osorio
authors.forename: M J
authors.initials: MJ
authors.lastname: García
authors.forename: G
authors.initials: G
authors.lastname: Echezarreta
authors.forename: C
authors.initials: C
authors.lastname: Rivas
authors.forename: J
authors.initials: J
authors.lastname: Benitez
mesh_terms: D002352:Carrier Proteins / Q000235:genetics*; D018797:Cell Cycle Proteins; D050762:Cyclin-Dependent Kinase Inhibitor p15; D019941:Cyclin-Dependent Kinase Inhibitor p16; D019175:DNA Methylation; D016147:Genes, Tumor Suppressor; D019942:Genes, p16; D006801:Humans; D018442:Lymphoma, B-Cell, Marginal Zone / Q000235:genetics; D008228:Lymphoma, Non-Hodgkin / Q000235:genetics*; D025521:Tumor Suppressor Proteins
chemical_list: C493966:CDKN2B protein, human; D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D050762:Cyclin-Dependent Kinase Inhibitor p15; D019941:Cyclin-Dependent Kinase Inhibitor p16; D025521:Tumor Suppressor Proteins