RESUMEN
OBJECTIVES: We previously reported loss of heterozygosity on 1p in chronic myelogenous leukemia (CML). We analyzed promoter methylation and mutation of tumor suppressor genes on 1p36 in CML. METHODS: We performed methylation-specific PCR (MS-PCR) analysis of the PRDM2, RUNX3, and TP73 genes in 61 patients with CML (43 chronic phase, CP; two accelerated phase; and 16 blast crisis, BC). Oxidative MS-PCR, PCR-single-strand conformation polymorphism, and real-time reverse transcriptase PCR were also analyzed. K-562 cells were grown in the presence of 5-Aza-dC and trichostatin A. RESULTS: Methylation of the PRDM2, RUNX3, and TP73 genes was detected in 24/60 (40%), 21/61 (34%), and 28/60 (47%) patients, respectively. Methylation of all three genes was detected in 19/59 (32%) patients. Methylation was more frequent in BC than in CP. Oxidative MS-PCR analysis detected 5-mC in the PRDM2, RUNX3, and TP73 genes in 10/22 (45%), 15/21 (71%), and 16/26 (62%) samples with methylation detected by MS-PCR, respectively. Decreased expression was observed in several samples with methylation, while no mutations were found in the genes. Treatment of K-562 cells induced growth suppression, demethylation, and reexpression of the PRDM2 and RUNX3 genes. CONCLUSION: Multiple tumor suppressor genes on 1p were inactivated in CML by methylation.
Asunto(s)
Cromosomas Humanos Par 1 , Metilación de ADN , Genes Supresores de Tumor , Leucemia Mielógena Crónica BCR-ABL Positiva/genética , Adulto , Anciano , Línea Celular Tumoral , Subunidad alfa 3 del Factor de Unión al Sitio Principal/genética , Proteínas de Unión al ADN/genética , Femenino , Predisposición Genética a la Enfermedad , N-Metiltransferasa de Histona-Lisina/genética , Humanos , Cariotipificación , Leucemia Mielógena Crónica BCR-ABL Positiva/diagnóstico , Leucemia Mielógena Crónica BCR-ABL Positiva/tratamiento farmacológico , Masculino , Persona de Mediana Edad , Mutación , Estadificación de Neoplasias , Proteínas Nucleares/genética , Reacción en Cadena de la Polimerasa , Regiones Promotoras Genéticas , Análisis de Secuencia de ADN , Factores de Transcripción/genética , Proteína Tumoral p73/genéticaRESUMEN
To elucidate the relevance of genetic alterations, we analysed 17 genes known to be involved in haematological neoplasms in patients with chronic leucocytosis and patients with persistent thrombocytosis. Mutations of the JAK2, SETBP1 and ASXL1 genes were found in 1/13, 1/13, and 2/13 patients with leucocytosis, respectively. Mutations of the JAK2, CALR, SETBP1 and ASXL1 genes were found in 1/5, 1/5, 1/5 and 2/5 patients with thrombocytosis, respectively. One leucocytosis patient with a JAK2 V617F mutation developed polycythaemia vera. Another leucocytosis patient developed Philadelphia chromosome-negative chronic myeloid leukaemia (Ph(-) CML) accompanied by t(9;12)(q34.1;p13.?3) (Mori et al. 2016). Another leucocytosis patient with mutations of the SETBP1 and ASXL1 genes progressed to blast crisis of Ph(-) CML accompanied by i(17)(q10). Chronic leucocytosis patients who had genetic alterations tended to develop haematological neoplasms, while thrombocytosis unexpectedly resolved in two persistent thrombocytosis patients with genetic alterations.