Clonal heterogeneity in the 5q- syndrome: p53 expressing progenitors prevail during lenalidomide treatment and expand at disease progression.
Clonal heterogeneity has not been described in patients with myelodysplastic syndrome with isolated del(5q), for which lenalidomide has emerged as a highly potent treatment. However, transformation to acute myeloid leukemia is occasionally observed, particularly in patients without a cytogenetic response to lenalidomide. We performed molecular studies in a patient with classical 5q- syndrome with complete erythroid and partial cytogenetic response to lenalidomide, who evolved to high-risk myelodysplastic syndrome with complex karyotype. Immunohistochemistry of pre-treatment marrow biopsies revealed a small fraction of progenitors with overexpression of p53 and sequencing confirmed a TP53 mutation. TP53 mutated subclones have not previously been described in myelodysplastic syndrome with isolated del(5q) and indicates a previously unknown heterogeneity of this disease. The aberrant subclone remained stable during the treatment with lenalidomide and expanded at transformation, suggesting that this pre-existing cell population had molecular features which made it insensitive to lenalidomide and prone to disease progression.
Karolinska Institutet, Department of Medicine, Center for Experimental Hematology, Karolinska University Hospital, Stockholm, Sweden. martin.jadersten@ki.se
Martin
M
Jädersten
Leonie
L
Saft
Andrea
A
Pellagatti
Gudrun
G
Göhring
James S
JS
Wainscoat
Jacqueline
J
Boultwood
Anna
A
Porwit
Brigitte
B
Schlegelberger
Eva
E
Hellström-Lindberg
D000368:Aged; D000970:Antineoplastic Agents / Q000627:therapeutic use; D001854:Bone Marrow Cells / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D002871:Chromosome Banding; D002872:Chromosome Deletion; D002895:Chromosomes, Human, Pair 5 / Q000235:genetics*; D002999:Clone Cells / Q000378:metabolism / Q000473:pathology; D018450:Disease Progression; D005260:Female; D020869:Gene Expression Profiling; D018740:Genetic Heterogeneity; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D000077269:Lenalidomide; D009154:Mutation; D009190:Myelodysplastic Syndromes / Q000188:drug therapy / Q000235:genetics* / Q000473:pathology; D013792:Thalidomide / Q000031:analogs & derivatives / Q000627:therapeutic use; D016159:Tumor Suppressor Protein p53 / Q000235:genetics
D000970:Antineoplastic Agents; D016159:Tumor Suppressor Protein p53; D013792:Thalidomide; D000077269:Lenalidomide