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 characterized by a block in differentiation where leukemic cells are halted at the promyelocyte stage. A characteristic balanced chromosomal translocation between chromosomes 15 and 17 t (15;17) (q24; q21) is seen in 95% of cases - the translocation results in the formation of the PML-RARA fusion protein. The introduction of retinoic acid (RA) and arsenic trioxide (ATO) has been responsible for initially remarkable cure rates. However, relapsed APL, particularly in the high-risk subset of patients, remains an important clinical problem. In addition, despite the success of ATRA & ATO, many clinicians still elect to use cytotoxic chemotherapy in the treatment of APL. Patients who become resistant to ATO have an increased risk of mortality. The probability of relapse is significantly higher in the high-risk subset of patients undergoing treatment for APL; overall approximately 10-20% of APL patients relapse regardless of their risk stratification. Furthermore, 20-25% of patients undergoing treatment will develop differentiation syndrome, a common side effect of differentiation agents. Recent evidence using in vitro models has shown that mutations in the B2 domain of the PML protein, mediate arsenic resistance. Alternative agents and approaches considering these clinical outcomes are needed to address ATO resistance as well as the relapse rate in high risk APL.
Project description:BackgroundAcute promyelocytic leukemia (APL) is considered a hematologic emergency due to high risk of bleeding and fatal hemorrhages being a major cause of death. Despite lower death rates reported from clinical trials, patient registry data suggest an early death rate of 20%, especially for elderly and frail patients. Therefore, reliable diagnosis is required as treatment with differentiation-inducing agents leads to cure in the majority of patients. However, diagnosis commonly relies on cytomorphology and genetic confirmation of the pathognomonic t(15;17). Yet, the latter is more time consuming and in some regions unavailable.MethodsIn recent years, deep learning (DL) has been evaluated for medical image recognition showing outstanding capabilities in analyzing large amounts of image data and provides reliable classification results. We developed a multi-stage DL platform that automatically reads images of bone marrow smears, accurately segments cells, and subsequently predicts APL using image data only. We retrospectively identified 51 APL patients from previous multicenter trials and compared them to 1048 non-APL acute myeloid leukemia (AML) patients and 236 healthy bone marrow donor samples, respectively.ResultsOur DL platform segments bone marrow cells with a mean average precision and a mean average recall of both 0.97. Further, it achieves high accuracy in detecting APL by distinguishing between APL and non-APL AML as well as APL and healthy donors with an area under the receiver operating characteristic of 0.8575 and 0.9585, respectively, using visual image data only.ConclusionsOur study underlines not only the feasibility of DL to detect distinct morphologies that accompany a cytogenetic aberration like t(15;17) in APL, but also shows the capability of DL to abstract information from a small medical data set, i. e. 51 APL patients, and infer correct predictions. This demonstrates the suitability of DL to assist in the diagnosis of rare cancer entities. As our DL platform predicts APL from bone marrow smear images alone, this may be used to diagnose APL in regions were molecular or cytogenetic subtyping is not routinely available and raise attention to suspected cases of APL for expert evaluation.
Project description:The application of all-trans retinoic acid (ATRA) and arsenic trioxide (ATO) has revolutionized the treatment of acute promyelocytic leukemia (APL). More than 80-90% of patients are expected to be cured with a combination of ATRA, ATO and/or chemotherapy. In this review, we focus on the remaining obstacles to a cure for all patients with APL. We review the issue of early death and coagulopathy and discuss the particular challenges in the care of patients with high-risk APL and patients with relapsed APL. We also give recommendations and highlight ongoing efforts to improve the persistently high early death rate and the outcomes of high risk and relapsed APL patients.