Project description:Acute Promyelocytic Leukemia (APL) is characterized by the t(15;17)(q22;q11.2) translocation, which creates a PML-RARA fusion gene that can initiate APL in mice. To discover cooperating mutations in this model, we sequenced a mouse APL genome to 15.6x haploid coverage, and discovered three somatic, non-synonymous mutations, of which one (Jak1 V657F) was recurrent. This mutation is identical to the JAK1 V658F mutation previously found in human APL and ALL samples. JAK1 V658F cooperates in vivo with PML-RARA, causing a rapidly fatal leukemia. We also discovered a somatic 150kb deletion involving the Kdm6a/Utx gene in the mouse APL genome; 3/14 additional mouse APL samples had similar deletions involving Kdm6a/Utx. Kdm6A/Utx, a histone H3K27 demethylase, was also deleted in 1/150 human AML samples tested. Whole genome sequencing of mouse cancer genomes provides an unbiased approach for discovering functionally relevant mutations that are also present in human leukemias. DNA from 15 mouse APL tumors on the Bl/6 Taconic background (F10), DNA from one WT 129/SvJ mouse spleen, and pooled DNA derived from the spleens of 6-week-old, wild type, Bl/6 Taconic (parental strain) mice were analyzed using the Nimblegen Mouse CGH 3x720K WGT platform.
Project description:Acute Promyelocytic Leukemia (APL) is characterized by the t(15;17)(q22;q11.2) translocation, which creates a PML-RARA fusion gene that can initiate APL in mice. To discover cooperating mutations in this model, we sequenced a mouse APL genome to 15.6x haploid coverage, and discovered three somatic, non-synonymous mutations, of which one (Jak1 V657F) was recurrent. This mutation is identical to the JAK1 V658F mutation previously found in human APL and ALL samples. JAK1 V658F cooperates in vivo with PML-RARA, causing a rapidly fatal leukemia. We also discovered a somatic 150kb deletion involving the Kdm6a/Utx gene in the mouse APL genome; 3/14 additional mouse APL samples had similar deletions involving Kdm6a/Utx. Kdm6A/Utx, a histone H3K27 demethylase, was also deleted in 1/150 human AML samples tested. Whole genome sequencing of mouse cancer genomes provides an unbiased approach for discovering functionally relevant mutations that are also present in human leukemias.
Project description:About 5-10% newly diagnosed and about 20-30% of relapsed acute promyelocytic leukemia (APL) patients will have disease recurrence after receiving currently accepted standards of care. While there are reports of micro-environment mediated drug resistance (EM-DR) in AML, there is no data on the effect of malignant promyelocyte and stromal interaction on Arsenic trioxide (ATO) induced apoptosis. We undertook a preliminary study to evaluate the role of EM-DR to ATO in APL. In direct co-culture (contact dependent system) of malignant promyelocyte with stromal cells, the stromal cells gave a significant protective effect against ATO at different concentrations used (1 to 8 μmol; NB4 (APL cell line) In a gene expression profiling comparing NB4 cells in co-culture with NB4 cells alone, 1846 genes were differentially regulated. On a preliminary analysis, we observed an up-regulation of various pathways such as adhesion (ITGB1, ITGB2, ITGB7, etc.), Cytokines (IL-6, IL-8, IL-18, CCL2, CCL10, etc.) Wnt signalling (Wnt5a, Wnt11, NFATC4, etc,) NF-kB pathway (ICAM1, BIRC2, BIRC3, XIAP1, etc.) in the leukemic cells. The NF-kB pathway has been validated using real time PCR which correlated with the genes being differentially regulated in NB4 cells co-cultured in stroma.
Project description:About 5-10% newly diagnosed and about 20-30% of relapsed acute promyelocytic leukemia (APL) patients will have disease recurrence after receiving currently accepted standards of care. While there are reports of micro-environment mediated drug resistance (EM-DR) in AML, there is no data on the effect of malignant promyelocyte and stromal interaction on Arsenic trioxide (ATO) induced apoptosis. We undertook a preliminary study to evaluate the role of EM-DR to ATO in APL. In direct co-culture (contact dependent system) of malignant promyelocyte with stromal cells, the stromal cells gave a significant protective effect against ATO at different concentrations used (1 to 8 μmol; NB4 (APL cell line) In a gene expression profiling comparing NB4 cells in co-culture with NB4 cells alone, 1846 genes were differentially regulated. On a preliminary analysis, we observed an up-regulation of various pathways such as adhesion (ITGB1, ITGB2, ITGB7, etc.), Cytokines (IL-6, IL-8, IL-18, CCL2, CCL10, etc.) Wnt signalling (Wnt5a, Wnt11, NFATC4, etc,) NF-kB pathway (ICAM1, BIRC2, BIRC3, XIAP1, etc.) in the leukemic cells. The NF-kB pathway has been validated using real time PCR which correlated with the genes being differentially regulated in NB4 cells co-cultured in stroma. Agilent one-color experiment,Organism: Homo sapiens ,Custom Agilent 8x60k Human Whole Genome Microarray Gene expression (AMADID: 039494) , Labeling kit: Agilent Quick-Amp labeling Kit (p/n5190-0442)
Project description:Here we report a novel fusion gene, RUNX1-RARA, in acute promyelocytic leukemia (APL). RUNX1-RARA triggers APL genesis by mediating transcriptional repression of target genes, and it can be potently restrained by all-trans retinoic acid treatment.
Project description:About 5-10% newly diagnosed and about 20-30% of relapsed acute promyelocytic leukemia (APL) patients will have disease recurrence after receiving currently accepted standards of care. While there are reports of micro-environment mediated drug resistance (EM-DR) in AML, there is no data on the effect of malignant promyelocyte and stromal interaction on Arsenic trioxide (ATO) induced apoptosis. There are limited study available on the effect of leukemic cell interaction on stromal cells. We undertook a preliminary study to evaluate the changes induced by leukemic cells on stromal cells. In a gene expression profiling comparing HS-5 cells in co-culture with NB4 cells alone, 8456 genes were differentially regulated. On a preliminary analysis, we observed an up-regulation of various pathways such as adhesion, Cytokines, Wnt signalling in the stromal cells.
Project description:Acute promyelocytic leukemia (APL) is a subtype of myeloid leukemia characterized by differentiation block at the promyelocyte stage. Besides the presence of chromosomal rearrangement t(15;17) leading to formation of PML-RARA fusion, other genetic alterations have also been implicated in APL. Here, we performed comprehensive mutational analysis of primary and relapse APL to identify somatic alterations which cooperate with PML-RARA in the pathogenesis of APL. We explored the mutational landscape using whole-exome (n=12) and subsequent targeted sequencing of 398 genes in 153 primary and 69 relapse APL. Both primary and relapse APL harbored an average of eight non-silent somatic mutations per exome. We observed recurrent alterations of FLT3, WT1, NRAS and KRAS in the newly diagnosed APL, while mutations in other genes commonly mutated in myeloid leukemia were rarely detected. The molecular signature of APL relapse was characterized by emergence of frequent mutations in PML and RARA genes. Our sequencing data also demonstrates incidence of loss-of-function mutations in previously unidentified genes, ARID1B and ARID1A, both of which encode for key components of the SWI/SNF complex. We show that knockdown of ARID1B in APL cell line, NB4, results in large scale activation of gene expression and reduced in vitro differentiation potential.