RESUMEN
TP73 encodes for two proteins: full-length TAp73 and DeltaNp73, which have little transcriptional activity and exert dominant-negative function towards TP53 and TAp73. We compared TATP73 and DeltaNTP73 expression in acute myeloid leukaemia (AML) samples and normal CD34(+) progenitors. Both forms were more highly expressed in leukaemic cells. Amongst AML blasts, TATP73 was more expressed in AML harbouring the recurrent genetic abnormalities (RGA): PML-RARA, RUNX1-RUNX1T1 and CBFB-MYH11, whereas higher DeltaNTP73 expression was detected in non-RGA cases. TP53 expression did not vary according to DeltaNTP73/TATP73 expression ratio. Leukaemic cells with higher DeltaNTP73/TATP73 ratios were significantly more resistant to cytarabine-induced apoptosis.
Asunto(s)
Antimetabolitos Antineoplásicos/uso terapéutico , Citarabina/uso terapéutico , Proteínas de Unión al ADN/genética , Genes p53/genética , Leucemia Mieloide Aguda/genética , Proteínas Nucleares/genética , Proteínas Supresoras de Tumor/genética , Apoptosis/efectos de los fármacos , Aberraciones Cromosómicas , Resistencia a Antineoplásicos , Expresión Génica , Reordenamiento Génico , Humanos , Reacción en Cadena de la Polimerasa , RecurrenciaRESUMEN
The use of all trans-retinoic acid (ATRA) is the basis of treatment of acute promyelocytic leukemia (APL) and represents the paradigm of differentiation therapy. In general, ATRA is well-tolerated but may be associated with a potentially lethal side-effect, referred to as retinoic acid or differentiation syndrome (DS). The cellular and molecular mechanisms of DS are poorly understood and involve changes in the adhesive qualities and cytokine secretion of leukemic cells during ATRA-induced differentiation. As leukocyte extravasation is a key event in DS pathogenesis, we analyzed the association between the polymorphisms at Exon 4 (G241R) and Exon 6 (E469K) of ICAM-1 and Exon 3 (L125V) of PECAM-1 genes with DS development in APL patients treated with ATRA and anthracyclines. DS was diagnosed in 23/127 (18.1%) APL patients at an average of 11.5 days after the start of ATRA. All patients presented respiratory distress associated with increased ground-glass opacity in chest radiographies. Other accompanying symptoms were: fever not attributable to infection (65.2%), generalized edema (37.5%), weight gain (37.5%), and impairment of renal function (8.6%). We detected an association between development of DS and the AA genotype at Codon 469 of ICAM-1 (odds ratio of 3.5; 95% confidence interval: 1.2-10.2). Conversely, no significant association was detected between G241R or L125V polymorphisms at Exon 4 of ICAM-1 and Exon 3 of PECAM-1, respectively. Our results suggest that susceptibility to DS in APL patients may be influenced by genetic variation in adhesion molecule loci.