Project description:Neomorphic mutations in isocitrate dehydrogenase 1 (IDH1) are driver mutations in acute myeloid leukemia (AML) and other cancers. We report the development of new allosteric inhibitors of mutant IDH1. Crystallographic and biochemical results demonstrated that compounds of this chemical series bind to an allosteric site and lock the enzyme in a catalytically inactive conformation, thereby enabling inhibition of different clinically relevant IDH1 mutants. Treatment of IDH1 mutant primary AML cells uniformly led to a decrease in intracellular 2-HG, abrogation of the myeloid differentiation block and induction of granulocytic differentiation at the level of leukemic blasts and more immature stem-like cells, in vitro and in vivo. Molecularly, treatment with the inhibitors led to a reversal of the DNA cytosine hypermethylation patterns caused by mutant IDH1 in AML patients’ cells. Our study provides proof-of-concept for the molecular and biological activity of novel allosteric inhibitors for targeting different mutant forms of IDH1 in leukemia. To obtain insight into the molecular mechanism of the novel IDH1 mutant allosteric inhibitor, primary AML cells were treated with either GSK321 IDH1 active inhibitor or Controls (DMSO or GSK990 inactive inhibitor) followed by DNA extraction for ERRBS analysis. Primary IDH1 mutant acute myeloid leukemia (AML) mononuclear (MNC) cells were treated in suspension cultures in differentiating media for 6 days with 3 microM GSK990 or GSK321 and an equal volume of DMSO, Followed ERRBS analysis after DNA extraction.
Project description:Neomorphic mutations in isocitrate dehydrogenase 1 (IDH1) are driver mutations in acute myeloid leukemia (AML) and other cancers. We report the development of new allosteric inhibitors of mutant IDH1. Crystallographic and biochemical results demonstrated that compounds of this chemical series bind to an allosteric site and lock the enzyme in a catalytically inactive conformation, thereby enabling inhibition of different clinically relevant IDH1 mutants. Treatment of IDH1 mutant primary AML cells uniformly led to a decrease in intracellular 2-HG, abrogation of the myeloid differentiation block and induction of granulocytic differentiation at the level of leukemic blasts and more immature stem-like cells, in vitro and in vivo. Molecularly, treatment with the inhibitors led to a reversal of the DNA cytosine hypermethylation patterns caused by mutant IDH1 in AML patients’ cells. Our study provides proof-of-concept for the molecular and biological activity of novel allosteric inhibitors for targeting different mutant forms of IDH1 in leukemia. To obtain insight into the molecular mechanism for the induction of granulocytic differentiation and cell death following inhibition of IDH1 mutant protein in primary AML cells, we performed gene expression microarrays following treatment with either GSK321 IDH1 inhibitor or Controls (DMSO or GSK990 inactive inhibitor). Primary IDH1 mutant acute myeloid leukemia (AML) mononuclear (MNC) cells were treated in suspension cultures in differentiating media for 6 days with 3 microM GSK990 or GSK321 and an equal volume of DMSO. Followed by microarray analysis after RNA extraction.
Project description:Neomorphic mutations in isocitrate dehydrogenase 1 (IDH1) are driver mutations in acute myeloid leukemia (AML) and other cancers. We report the development of new allosteric inhibitors of mutant IDH1. Crystallographic and biochemical results demonstrated that compounds of this chemical series bind to an allosteric site and lock the enzyme in a catalytically inactive conformation, thereby enabling inhibition of different clinically relevant IDH1 mutants. Treatment of IDH1 mutant primary AML cells uniformly led to a decrease in intracellular 2-HG, abrogation of the myeloid differentiation block and induction of granulocytic differentiation at the level of leukemic blasts and more immature stem-like cells, in vitro and in vivo. Molecularly, treatment with the inhibitors led to a reversal of the DNA cytosine hypermethylation patterns caused by mutant IDH1 in AML patients’ cells. Our study provides proof-of-concept for the molecular and biological activity of novel allosteric inhibitors for targeting different mutant forms of IDH1 in leukemia. To obtain insight into the molecular mechanism of the novel IDH1 mutant allosteric inhibitor, primary AML cells were treated with either GSK321 IDH1 active inhibitor or Controls (DMSO or GSK990 inactive inhibitor) followed by DNA extraction for ERRBS analysis.
Project description:Neomorphic mutations in isocitrate dehydrogenase 1 (IDH1) are driver mutations in acute myeloid leukemia (AML) and other cancers. We report the development of new allosteric inhibitors of mutant IDH1. Crystallographic and biochemical results demonstrated that compounds of this chemical series bind to an allosteric site and lock the enzyme in a catalytically inactive conformation, thereby enabling inhibition of different clinically relevant IDH1 mutants. Treatment of IDH1 mutant primary AML cells uniformly led to a decrease in intracellular 2-HG, abrogation of the myeloid differentiation block and induction of granulocytic differentiation at the level of leukemic blasts and more immature stem-like cells, in vitro and in vivo. Molecularly, treatment with the inhibitors led to a reversal of the DNA cytosine hypermethylation patterns caused by mutant IDH1 in AML patients’ cells. Our study provides proof-of-concept for the molecular and biological activity of novel allosteric inhibitors for targeting different mutant forms of IDH1 in leukemia. To obtain insight into the molecular mechanism for the induction of granulocytic differentiation and cell death following inhibition of IDH1 mutant protein in primary AML cells, we performed gene expression microarrays following treatment with either GSK321 IDH1 inhibitor or Controls (DMSO or GSK990 inactive inhibitor).
Project description:Mutations in the enzymes IDH1 and IDH2 have been identified in a wide variety of tumors like glioma, chondrosarcoma, thyroid cancer, lymphoma, melanoma, and in acute myeloid leukemia. Mutated IDH1/2 produces the metabolite 2-hydroxyglutarate (2HG), which interferes with epigenetic regulation of gene expression, and thus may promote tumorigenesis. Data for IDH1 inhibitors show that 30-40% of AML patients respond to monotherapy with a median duration of response of 8 months, suggesting that IDH1 inhibitors should be combined with other agents to improve efficacy. BAY 1436032 (BAY) is an oral pan-mutant IDH1 inhibitor currently undergoing phase 1 clinical trials. 5-Azacitidine (AZA) is a hypomethylating agent and can activate key epigenetically silenced pathways in AML cells, leading to an arrest of AML cell proliferation.
Project description:Mutations in the enzymes IDH1 and IDH2 have been identified in a wide variety of tumors like glioma, chondrosarcoma, thyroid cancer, lymphoma, melanoma, and in acute myeloid leukemia. Mutated IDH1/2 produces the metabolite 2-hydroxyglutarate (2HG), which interferes with epigenetic regulation of gene expression, and thus may promote tumorigenesis. Data for IDH1 inhibitors show that 30-40% of AML patients respond to monotherapy with a median duration of response of 8 months, suggesting that IDH1 inhibitors should be combined with other agents to improve efficacy. BAY 1436032 (BAY) is an oral pan-mutant IDH1 inhibitor currently undergoing phase 1 clinical trials. 5-Azacitidine (AZA) is a hypomethylating agent and can activate key epigenetically silenced pathways in AML cells, leading to an arrest of AML cell proliferation.
Project description:Mutations in the enzymes IDH1 and IDH2 have been identified in a wide variety of tumors like glioma, chondrosarcoma, thyroid cancer, lymphoma, melanoma, and in acute myeloid leukemia. Mutated IDH1/2 produces the metabolite 2-hydroxyglutarate (2HG), which interferes with epigenetic regulation of gene expression, and thus may promote tumorigenesis. Data for IDH1 inhibitors show that 30-40% of AML patients respond to monotherapy with a median duration of response of 8 months, suggesting that IDH1 inhibitors should be combined with other agents to improve efficacy. BAY 1436032 (BAY) is an oral pan-mutant IDH1 inhibitor currently undergoing phase 1 clinical trials. 5-Azacitidine (AZA) is a hypomethylating agent and can activate key epigenetically silenced pathways in AML cells, leading to an arrest of AML cell proliferation.
Project description:Acute Myeloid Leukemia (AML) is the most common and aggressive form of acute leukemia, with a 5-year survival rate of just 24%. Over a third of all AML patients harbor activating mutations in kinases, such as the receptor tyrosine kinases FLT3 and KIT. FLT3 and KIT mutations are associated with poor clinical outcomes and lower remission rates in response to standard-of-care chemotherapy. We have recently identified that the core kinase of the non-homologous end joining DNA repair pathway, DNA-PK, is activated downstream of FLT3; and targeting DNA-PK sensitized FLT3-mutant AML cells to standard-of-care therapies. Herein, we investigated DNA-PK as a possible therapeutic vulnerability in KIT mutant AML, using isogenic FDC-P1 myeloid progenitor cell lines transduced with an empty vector or oncogenic mutant KIT (V560G, D816V). Targeted quantitative phosphoproteomic profiling identified phosphorylation of DNA-PK at threonine 2599 in KIT mutant cells, indicative of DNA-PK activation. Accordingly, proliferation assays revealed that KIT mutant FDC-P1 cells were more sensitive to the DNA-PK inhibitors M3814 or NU7441, compared to empty vector controls. DNA-PK inhibition combined with inhibition of KIT signaling via using the kinase inhibitors dasatinib or ibrutinib, or the protein phosphatase 2A activators FTY720 or AAL(S), led to synergistic cell death. Discovery phosphoproteomic analysis of KIT-D816V cells revealed that dasatinib single-agent treatment inhibited ERK1 activity, and M3814 single-agent treatment inhibited Akt/mTOR activity. The combination of dasatinib and M3814 treatment inhibited both ERK/MAPK and Akt/mTOR activity, and induced synergistic inhibition of phosphorylation of transcription regulators including MYC and MYB. This study provides insight into the oncogenic pathways regulated by DNA-PK beyond its canonical role in DNA repair, and demonstrates that DNA-PK is a promising novel therapeutic target for KIT mutant cancers.