Project description:We establish a Cre-ERT2-loxP (causes recombination, estrogen receptor mutant T2, locus of X-over P1) based inducible RNAi- (ribonucleic acid interference) mediated gene silencing system in patient-derived xenograft (PDX) models of acute leukemias in vivo. Mimicking anti-cancer therapy in patients, gene inhibition is initiated in mice harboring orthotopic tumors. In fluorochrome guided, competitive in vivo trials, silencing of the apoptosis regulator MCL1 (myeloid cell leukemia sequence 1) correlates to pharmacological MCL1 inhibition in patients´ tumors, demonstrating the ability of the method to detect therapeutic vulnerabilities.
Project description:We generate CRISPR/Cas9 patient derived xenograft (PDX) models of acute myeloid leukemia. Mimicking anti-cancer therapy in patients, PDX cells with gene knockouts were re-transplanted into mice. In fluorochromes guided, competitive in vivo trials, a subset of PDX models showed a clear growth disadvantage upon knockout, indicating essential functions for WT1 and DNMT3A.
Project description:We establish a Cre-ERT2-loxP (causes recombination, estrogen receptor mutant T2, locus of X-over P1) based inducible RNAi- (ribonucleic acid interference) mediated gene silencing system in patient-derived xenograft (PDX) models of acute leukemias in vivo. Mimicking anti-cancer therapy in patients, gene inhibition is initiated in mice harboring orthotopic tumors. In fluorochrome guided, competitive in vivo trials, silencing of DUX4 (double homeobox 4) playes an essential role in patients’ leukemias carrying the recently described DUX4-IGH (immunoglobulin heavy chain) translocation, while the downstream mediator DDIT4L (DNA-damage-inducible transcript 4 like) is identified as therapeutic vulnerability.
Project description:Cryopreserved AML PDX samples were collected with minimal harm to the sample by taking a biopsy punch from the vial of cell and transfering it into lysis buffer. 96 AML PDX samples collected in such manner were processed using prime-seq to generate high quality expression profiles.
Project description:Patients with acute myeloid leukemia (AML) suffer dismal prognosis and the most adverse subpopulation within each tumor determines patient’s prognosis. To better understand challenging features in AML, we studied individual stem cells from a single AML sample, complementing genomic with in vivo functional studies. Primary tumor cells from an AML patient’s first and second relapse were transplanted into NSG mice to establish serially transplantable patient derived xenografts (PDX). In an innovative approach, twelve derivative PDX clones were generated thereof, each derived from a single AML stem cell as proven by molecular barcoding, and were color-marked to facilitate multiplex competitive in vivo assays. PDX clones consisted of four different genomic clusters; one cluster displayed resistance against Cytarabine treatment, while two other clusters harbored increased stem cell potential, indicating that stemness and treatment resistance had evolved independently in the sample. In vivo functional data correlated closely with the phylogenetic tree calculated from exome data. The Cytarabine-resistant cluster was characterized by a distinct gene expression profile, and a score thereof predicted outcome in large clinical patient data cohorts. Taken together, we provide proof of concept that intra-sample heterogeneity mimics inter-sample heterogeneity in AML. Stem cell disparities within a single sample allow insights into adverse characteristics of general importance for AML.
Project description:RNA-seq analysis of RNAs isolated from primary FLT3-ITD+ AML cells in the spleen and bone marrow from xenograft mouse model after 16 hours of treatment with FLT3 inhibitor AC220 (quizartinib)
Project description:Genome wide DNA methylation profiling of AML patient samples treated with PBS or DAC. The Illumina Infinium 450 Human DNA methylation was used to examine the methylation profile of 8 patient samples and 2 cell lines. Genome wide DNA methylation profiling of AML xenografts treated with either PBS control or with decitacine (DAC) alone, cytarabine (Ara-C) alone, DAC and Ara-C together (D+A), DAC followed by Ara-C (D/A) or with Ara-C followed by DAC (A/D). DNA was extracted from patient bone marrow samples and xenograft bone marrow samples using Qiagen Allprep kit. Bisulphite converted DNA from all samples were hybridised to the Illumina Infinium 450 Human Methylation arrays and for each analysis the drug treated sample was compared to the corresponding PBS control sample.