Methylation status analysis of cell cycle regulatory genes (p16INK4A, p15INK4B, p21Waf1/Cip1, p27Kip1 and p73) in natural killer cell disorders.
Natural killer (NK) cell disorders are rare diseases. Genetic abnormalities of the several tumor suppressor genes, including p15INK4B, p16INK4A/p14ARF, p53, p73, and Rb genes have been reported. Deletions and point mutations of these genes are frequently detected in these diseases. It has been reported that tumor suppressor genes are inactivated by DNA methylation of the promoter region and/or first exon of the genes in a variety of human cancers. In this study we analyze the methylation status of the genes associated with cell cycle regulation, including p16INK4A, p15INK4B, p21/Waf1/Cip1, p27/Kip1, p73, and p14ARF, by methylation specific (MS) PCR and/or bisulfite sequencing. We examined 29 cases of NK cell disorders (five aggressive NK cell leukemia/lymphoma, three blastic NK cell lymphoma/leukemia, five nasal NK cell lymphoma, three myeloid/NK cell precursor acute leukemia, 13 chronic NK lymphocytosis). We found methylation of the first exon of the p16INK4A gene in two cases (one aggressive, one blastic), and methylation of the p14ARF gene in one aggressive NK cell leukemia. Bisulfite sequencing revealed that methylation of the p15 and p27 genes was rare in these disorders. MS-PCR suggested that the p73 and p21 genes were methylated in seven cases, respectively (p73: one blastic, one nasal, five chronic; p21: one myeloid/NK, one aggressive, one nasal, and four chronic); bisulfite sequencing confirmed that methylated alleles of these genes were dominant in the samples except three cases (one myeloid/NK, one aggressive, and one chronic) in which methylated alleles of the p21 genes were less than 34% of all alleles. These results suggested that inactivation of the cell cycle regulatory genes by DNA methylation could be associated with tumorigenesis in NK cell disorders, not only aggressive subtypes but also chronic subtype.
Kawamata
Norihiko
N
Division of Hematology, Juntendo University School of Medicine, Bunkyo-ku, Tokyo, Japan. kawamatan@cshs.org
Inagaki
Naoko
N
Mizumura
Sachiko
S
Sugimoto
Kei-Ji
KJ
Sakajiri
Sakura
S
Ohyanagi-Hara
Mutsuko
M
Oshimi
Kazuo
K
D001483:Base Sequence; D002453:Cell Cycle / Q000235:genetics*; D018797:Cell Cycle Proteins / Q000235:genetics*; D002908:Chronic Disease; D050762:Cyclin-Dependent Kinase Inhibitor p15; D019941:Cyclin-Dependent Kinase Inhibitor p16 / Q000235:genetics*; D050759:Cyclin-Dependent Kinase Inhibitor p21; D019175:DNA Methylation; D017931:DNA Primers; D004268:DNA-Binding Proteins / Q000235:genetics*; D016147:Genes, Tumor Suppressor; D006801:Humans; D007694:Killer Cells, Natural / Q000473:pathology / Q000502:physiology*; D007938:Leukemia / Q000145:classification / Q000235:genetics* / Q000473:pathology; D008223:Lymphoma / Q000235:genetics* / Q000473:pathology; D009687:Nuclear Proteins / Q000235:genetics*; D000072160:Tumor Protein p73; D025521:Tumor Suppressor Proteins / Q000235:genetics*
C493956:CDKN1A protein, human; C493966:CDKN2B protein, human; D018797:Cell Cycle Proteins; D050762:Cyclin-Dependent Kinase Inhibitor p15; D019941:Cyclin-Dependent Kinase Inhibitor p16; D050759:Cyclin-Dependent Kinase Inhibitor p21; D017931:DNA Primers; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; C000606460:TP73 protein, human; D000072160:Tumor Protein p73; D025521:Tumor Suppressor Proteins