Lenalidomide Resistance in del(5q) Myelodysplastic Syndrome Follows Loss of RUNX1/TP53-mediated Megakaryocytic Differentiation
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ABSTRACT:
PROVIDER: EGAS00001004113 | EGA |
REPOSITORIES: EGA
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Project description:Interstitial deletion of the long arm of chromosome 5 (del(5q)) is the commonest structural genomic variant in myelodysplastic syndromes (MDS). Lenalidomide (LEN) is the treatment of choice for patients with del(5q) MDS, but half of the responding patients become resistant within two years. TP53 mutations are detected in ~20% of patients who become resistant to LEN. Our data show that patients who become resistant to LEN harbor either TP53 or RUNX1 mutations or loss of RUNX1 expression. Here we show that LEN-induced degradation of IKZF1 permits a RUNX1/GATA2 complex to drive megakaryocytic differentiation and consequent del(5q) MDS progenitor cell death via CRBN-mediated CSNK1A1 degradation. Overexpression of GATA2 is able to restore LEN sensitivity in the context of RUNX1 or TP53 mutations by enhancing LEN-induced megakaryocytic differentiation. Screening for TP53 and RUNX1 mutations or downregulation should identify patients resistant to LEN, and strategies to activate GATA2 may resensitize del(5q) MDS cells to LEN.
| EGAD00001005769 | EGA
Project description:As part of this study, we isolated induced pluripotent stem cells (iPSCs) from a patient with TP53-mutant MDS and identified loss of chromosome 5q as a cooperating genetic event. Using RNA sequencing we found that loss of chromosome 5q dysregulates genes that maintain chromosome stability, predisposing TP53-mutant cells to chromosomal rearrangements and progression to complex karyotype.
2019-04-17 | GSE129851 | GEO
Project description:Lenalidome is a drug especially effective in low risk myelodysplastic syndromes (MDS) with isolated 5q deletion. However, 25% of the patients did not respond. TP53 mutations have been described to play a role in the disease progression, and karyotypic complexity also has an important impact in the outcome. We selected 53 MDS patients with 5q deletion and treated with lenalidomide and we studied by the following techniques: conventional G-banding cytogenetics (CC), single nucleotide polymorphism arrays (SNP-A) and sequencing, in order to assess their impact on treatment response and disease progression. Low karyotypic complexity (by CC), a high baseline platelet count (>280x103/L) and TP53 unmutated gene status are associated with the achievement of hematological response (P=0.005, P=0.008 and P=0.057, respectively). In a multivariate model, the most important predictors for lenalidomide failure are karyotypic complexity (P=0.014) and a platelet count below 280x103/L (P=0.042). Additionally, none of the TP53 mutated cases achieved complete cytogenetics response. Nevertheless, inclusion of defects by SNP-A did not allow for a better separation of responders and non responders. These findings constitute a useful reference data to be considered before lenalidomide treatment enrollment. Affymetrix SNP arrays were performed according to the manufacturer's directions on DNA extracted from bone marrow or peripheral blood and, in some cases, also lymphocytes CD3 isolated from peripheral blood samples. Copy number analyses of Affymetrix 250K and 6.0 SNP arrays were performed for 53 MDS with 5q deletion samples. There are also 30 samples from lymphocytes CD3 isolated from peripheral blood, which were used as germ-line DNA (control).
2013-07-01 | E-GEOD-35656 | biostudies-arrayexpress
Project description:Myelodysplastic syndromes (MDS) are clonal disorders of hematopoietic progenitors characterized by ineffective hematopoiesis and high propensity to leukemias. Although a number of gene targets have been identified, in many MDS cases, particular genetic targets are unknown. In this study, we performed genome-wide profiling of copy number (CN) abnormalities and allelic imbalances in MDS genomes in order to clarify the distribution of LOH (loss of heterozygosity) and identify their target genes. We analyzed a total of 171MDS and MDS/MPD specimens, including 7 RA/RARS, 23 RCMD/RCMD-RS, 6 5q-syndrome, 30 RAEB-1, 40 RAEB-2, 4 therapy related-MDS/AML, 5 MDSu, 17 CMML-1, 16 CMML-2, 24 overt AML, using high-density SNP arrays. The data were analyzed by CNAG/AsCNAR software we specifically developed for allele-specific CN analysis and sensitive LOH detection. MDS showed characteristic CN profiles in SNP array analysis. Of particular interest is the finding of high frequency of CN-neutral LOH (Uniparental disomy,UPD), which were observed in 51 of 171 (30%) MDS cases. They preferentially involved 1p, 1q, 4q, 7q, 11q, 17p and other chromosomal segments, which were associated with homozygous mutations of both loss-of-function mutations and gain-of function mutations of tumor suppressor genes and cellular oncogenes, including TP53 (17p UPD), AML1/RUNX1 (21q UPD), Nras and cMPL (1p UPD), JAK-2 (9p UPD), and FLT3 (13q UPD). Next we tried to identify a new gene target in 11q UPD, which was most common UPD region in this study and many of these cases were CMML with a normal karyotype. The minimum 11q UPD segment is about 2Mb which existed in 11q23. We sequenced coding exons of c-cbl and detected homozygous mutations in 8 of 9 MDS cases with 11q UPD (CMML= 5, RAEB= 3, overt leukemia= 1), but very rare in cases without 11q UPD (1/162), demonstrating that the mutation is tightly linked to 11q UPD. These mutations were 8 point mutations and 1 micro-deletion, they were accumulated in the linker or RING domain. These c-cbl mutants can transform NIH3T3 in a dominant manner and these mutants are phosphorylated and activate PI3K-Akt pathway. To investigate the functions of these mutants in hematopoietic cells, we introduced these mutants into c-kit(+)Sca1(+)Lin(-) murine bone marrow cells, it prolonged replating capacity of these hematopoietic progenitors. Keywords: SNP-chip To identify oncogenic lesions in MDS, we performed a genome-wide analysis of primary MDS samples using high-density SNP arrays (Affymetrix GeneChip).
2010-04-09 | E-GEOD-15187 | biostudies-arrayexpress
Project description:Mutations of RUNX1 are detected in patients with myelodysplastic syndrome (MDS). In particular, C-terminal truncation mutations lack a transcription regulatory domain and have increased DNA binding through the runt homology domain (RHD). The expression of the RHD, RUNX1(41-214), in mouse hematopoietic cells induced progression to MDS and acute myeloid leukemia (AML). Analysis of pre-myelodysplastic animals revealed expansion of c-Kit+Sca-1+Lin- (KSL) cells and skewed differentiation to myeloid at the expense of the lymphoid lineage. These abnormalities correlate with the phenotype of Runx1-deficient animals, as expected given the reported dominant-negative role of C-terminal mutations over the full-length RUNX1. However, MDS is not observed in Runx1-deficient animals. Gene expression profiling revealed that RUNX1(41-214) KSLs have an overlapping yet distinct gene expression profile from Runx1-deficient animals. Moreover, an unexpected parallel was observed between the hematopoietic phenotype of RUNX1(41-214) and aged animals. Genes deregulated in RUNX1(41-214), but not in Runx1-deficient animals, were inversely correlated with the aging gene signature of hematopoietic stem cells (HSC), suggesting that disruption of the expression of genes related to normal aging by RUNX1 mutations contributes to development of MDS. The data presented here provide insights into the mechanisms of development of MDS in HSCs by C-terminal mutations of RUNX1. Gene expression analysis were performed on c-Kit+/Sca-1+/Lin-/IL7Ra- (KSL) cells sorted from RUNX1(41-214)-expressing and Runx1-knockout (Runx1floxed/floxed MxCre+/-) and control mice (Runx1floxed/floxedMxCre-/-).
2012-11-29 | E-GEOD-40155 | biostudies-arrayexpress
Project description:Lenalidome is a drug especially effective in low risk myelodysplastic syndromes (MDS) with isolated 5q deletion. However, 25% of the patients did not respond. TP53 mutations have been described to play a role in the disease progression, and karyotypic complexity also has an important impact in the outcome. We selected 53 MDS patients with 5q deletion and treated with lenalidomide and we studied by the following techniques: conventional G-banding cytogenetics (CC), single nucleotide polymorphism arrays (SNP-A) and sequencing, in order to assess their impact on treatment response and disease progression. Low karyotypic complexity (by CC), a high baseline platelet count (>280x103/L) and TP53 unmutated gene status are associated with the achievement of hematological response (P=0.005, P=0.008 and P=0.057, respectively). In a multivariate model, the most important predictors for lenalidomide failure are karyotypic complexity (P=0.014) and a platelet count below 280x103/L (P=0.042). Additionally, none of the TP53 mutated cases achieved complete cytogenetics response. Nevertheless, inclusion of defects by SNP-A did not allow for a better separation of responders and non responders. These findings constitute a useful reference data to be considered before lenalidomide treatment enrollment.
2013-07-01 | GSE35656 | GEO
Project description:Despite the high response rates of individuals with myelodysplastic syndrome (MDS) with deletion of chromosome 5q (del(5q)) to treatment with lenalidomide (LEN) and the recent identification of cereblon (CRBN) as the molecular target of LEN, the cellular mechanism by which LEN eliminates MDS clones remains elusive. Here we performed an RNA interference screen to delineate gene regulatory networks that mediate LEN responsiveness in an MDS cell line, MDSL. We identified GPR68, which encodes a G-protein-coupled receptor that has been implicated in calcium metabolism, as the top candidate gene for modulating sensitivity to LEN. LEN induced GPR68 expression via IKAROS family zinc finger 1 (IKZF1), resulting in increased cytosolic calcium levels and activation of a calcium-dependent calpain, CAPN1, which were requisite steps for induction of apoptosis in MDS cells and in acute myeloid leukemia (AML) cells. In contrast, deletion of GPR68 or inhibition of calcium and calpain activation suppressed LEN-induced cytotoxicity. Moreover, expression of calpastatin (CAST), an endogenous CAPN1 inhibitor that is encoded by a gene (CAST) deleted in del(5q) MDS, correlated with LEN responsiveness in patients with del(5q) MDS. Depletion of CAST restored responsiveness of LEN-resistant non-del(5q) MDS cells and AML cells, providing an explanation for the superior responses of patients with del(5q) MDS to LEN treatment. Our study describes a cellular mechanism by which LEN, acting through CRBN and IKZF1, has cytotoxic effects in MDS and AML that depend on a calcium- and calpain-dependent pathway.
2016-06-08 | GSE82235 | GEO
Project description:We used CRISPR/Cas9 system to generate WT Control and RUNX1-KO MDS-L cells isolated as single clones from the parental MDS-L cell line. We have observed that RUNX1-KO MDS-L cells are resistant to Lenalidomide-induced cell death compared to WT Control MDS-L cells We have treated WT and RUNX1-KO MDS-L cells with 1µM Lenalidomide for 24h or 72h and performed expression analysis
2020-01-28 | GSE126265 | GEO
Project description:Mutations of RUNX1 are detected in patients with myelodysplastic syndrome (MDS). In particular, C-terminal truncation mutations lack a transcription regulatory domain and have increased DNA binding through the runt homology domain (RHD). The expression of the RHD, RUNX1(41-214), in mouse hematopoietic cells induced progression to MDS and acute myeloid leukemia (AML). Analysis of pre-myelodysplastic animals revealed expansion of c-Kit+Sca-1+Lin- (KSL) cells and skewed differentiation to myeloid at the expense of the lymphoid lineage. These abnormalities correlate with the phenotype of Runx1-deficient animals, as expected given the reported dominant-negative role of C-terminal mutations over the full-length RUNX1. However, MDS is not observed in Runx1-deficient animals. Gene expression profiling revealed that RUNX1(41-214) KSLs have an overlapping yet distinct gene expression profile from Runx1-deficient animals. Moreover, an unexpected parallel was observed between the hematopoietic phenotype of RUNX1(41-214) and aged animals. Genes deregulated in RUNX1(41-214), but not in Runx1-deficient animals, were inversely correlated with the aging gene signature of hematopoietic stem cells (HSC), suggesting that disruption of the expression of genes related to normal aging by RUNX1 mutations contributes to development of MDS. The data presented here provide insights into the mechanisms of development of MDS in HSCs by C-terminal mutations of RUNX1.
2012-11-29 | GSE40155 | GEO