Co-occurrence of cohesin complex and Ras signaling mutations during progression from myelodysplastic syndromes to secondary acute myeloid leukemia
Myelodysplastic syndromes (MDS) are hematological disorders at high risk of progression to secondary acute myeloid leukemia (sAML). However, the mutational dynamics and clonal evolution underlying disease progression are poorly understood at present. To elucidate the mutational dynamics of pathways and genes occurring during the evolution to sAML, next generation sequencing was performed on 84 serially paired samples of MDS patients who developed sAML (discovery cohort) and 14 paired samples from MDS patients who did not progress to sAML during follow-up (control cohort). Results were validated in an independent series of 388 MDS patients (validation cohort). We used an integrative analysis to identify how mutations, alone or in combination, contribute to leukemic transformation. The study showed that MDS progression to sAML is characterized by greater genomic instability and the presence of several types of mutational dynamics, highlighting increasing (STAG2) and newly-acquired (NRAS and FLT3) mutations. Moreover, we observed cooperation between genes involved in the cohesin and Ras pathways in 15-20% of MDS patients who evolved to sAML, as well as a high proportion of newly acquired or increasing mutations in the chromatin-modifier genes in MDS patients receiving a disease-modifying therapy before their progression to sAML. ; This work was supported by grants from the Spanish Fondo de Investigaciones Sanitarias FIS PI18/01500, PI17/01741, Instituto de Salud Carlos III (ISCIII), Fondo de Investigación Sanitaria (Instituto de Salud Carlos III – Contratos Río Hortega (CM17/0017), European Regional Development Fund (ERDF), Una manera de hacer Europa, European Union Seventh Framework Programme [FP7/2007-2013] under Grant Agreement nº306242-NGS-PTL, SYNtherapy: Synthetic Lethality for Personalized Therapy-based Stratification in Acute Leukemia (ERAPERMED2018-275); ISCIII (AC18/00093), Proyectos de Investigación del SACYL, Gerencia Regional de Salud de Castilla y León: GRS1850/A18, GRS1653/A17, and Centro de Investigación Biomédica en Red de Cáncer (CIBERONC CB16/12/00233). MMI is supported by a predoctoral grant from the Junta de Castilla y León, and by the Fondo Social Europeo (JCYL-EDU/556/2019 PhD scholarship) and JMHS is supported by a research grant from Fundación Española de Hematología y Hemoterapia.