11 janClonal architecture in chronic myelomonocytic leukemia11 jan 2013
Institut Gustave Roussy, Villejuif
Genomic studies in chronic myeloid malignancies, including myeloproliferative neoplasms (MPN), myelodysplastic syndromes (MDS), and MPN/MDS, have identified common mutations in genes encoding signaling, epigenetic, transcription and splicing factors. We interrogated the clonal architecture by mutation-specific discrimination analysis of single-cell-derived colonies in patients with chronic myelomonocytic leukemias (CMML), the most frequent MPN/MDS. This analysis reveals a linear acquisition of the studied mutations with limited branching through loss of heterozygosity. Serial analysis of untreated and treated samples demonstrates a dynamic architecture on which most current therapeutic approaches have limited effects. The main disease characteristics are early clonal dominance, arising at the CD34+/CD38- stage of hematopoiesis, and granulomonocytic differentiation skewing of multipotent and common myeloid progenitors. Comparison of clonal expansions of TET2 mutations in MDS, MPN and CMML, together with functional invalidation of TET2 in sorted progenitors, suggests a causative link between early clonal dominance and skewed granulomonocytic differentiation. Altogether, early clonal dominance may distinguish CMML from other chronic myeloid neoplasms with similar gene mutations.
Invited by Brigitte Bauvois
Location : Centre des Recherche des Cordeliers, Amphithéâtre Farabeuf, 15 rue de l'école de médecine, 75006 Paris at 12pm