Project: Epigenetic Innovations in Leukemia Therapies_x000D_
Recent research has provided evidence that epigenetic dysfunction plays a critical role in cancer onset and progression. These findings prompted us to evaluate the therapeutic potential as new cancer treatments of compounds that inhibit such epigenetic modifiers. One such enzyme is the lysine-specific histone demethylase LSD1, ORYZON has been instrumental in the development of novel, potent and specific inhibitors of LSD1 which are derived from the MAO inhibitor tranylcypromine._x000D_In preclinical studies done at the Paterson Institute for in the Leukaemia Biology Laboratory led by Dr Tim Somervaille, it was discovered that Oryzon’s LSD1 inhibitors used in the low nM range were able to induce differentiation of AML cells collected directly from patients treated at The Christie NHS Foundation Trust. This work, focusing on the MLL-mutated subtype of human AML (5-10% of cases) was published in Cancer Cell in April 2012 (Harris et al., Cancer Cell 21:473). At the same time another study (Schenk et al., Nature Medicine 11:605) reported that combination of LSD1 inhib. and ATRA synergize the differentiation of other AML subtypes. These studies, both published in leading biomedical journals, together make a powerful case for further research investigating the potential clinical use of LSD1 inhibitors as novel treatments for AML._x000D_Our work will be centered on: 1) the MoA of Oryzon’s LSD1 inhibitors; 2) pre-clinical studies addressing companion diagnostics, dosing strategies and evaluation of optimal combinations of drugs using both primary human AML cells and murine models; and 3) collaboration on an early phase clinical trial of ORY1001 in patients with relapsed AML._x000D_To address the MoA of LSD1 inhibitors we will use a human AML cell line model. Binding of LSD1 inhibitors may have consequences other than simply inhibiting its demethylase activity. Human AML cells which undergo robust differentiation following exposure to LSD1 inhibitor, will be treated with OG-LSD1 inhibitors, and control and treated cell samples collected over a time course. ChIP sequencing using mAbs versus H3K4Me1, -Me2, H3K9Me1 and -Me2 (the four known histone targets for LSD1) will be done for each time point, together with RNA sequencing (to correlate changes in methylation marks with gene expression), and ChIP sequencing for LSD1 (to enable distinction of loci where LSD1 is active in erasing histone methyl marks from those where it is not). Nuclear and subcellular fractionation experiments will determine whether LSD1 inhib, results in alteration of its physical interaction with chromatin or other members of chromatin regulatory complexes in which it is bound (eg HDACs, CoREST). _x000D_For dosing strategies and combinations of concomitantly delivered drugs, we will screen cell lines and primary patient cells from a range of haematological malignancies. Possible indications for LSD1 inhib. might include, in addition to MLL-mutated AML, 1) myeloproliferative disorders (MPD); 2) chronic myeloid leukaemia (CML) (might myeloid skewed CML stem cells be more sensitive to LSD1 inhibition than their normal HSPC counterparts?); 3) chronic myelomonocytic leukaemia (CMML), and other BCR-ABL negative CMMLs; 4) AML, as an agent to promote differentiation of AML blasts either administered concomitantly with chemotherapy, or as COtenance therapy following chemotherapy, 5) myelodysplasia (MDS), to prevent transformation of disease to AML in an analogous fashion to azacitidine, and 6) the MLL-AF4 subtype of acute lymphoblastic leukaemia (ALL). Cells from these conditions will be tested in in vitro colony forming assays with or without concomitantly administered drugs such as ATRA, HDACi, azacitidine etc. Normal human CD34+ cells will also be tested in a similar approach. These experiments will further define the in vitro sensitivity of normal and malignant human haematopoietic cells to LSD1 inhibition and provide critical preclinical information as to likely therapeutic indications._x000D_For optimal dosing strategy for LSD1 inhibitors, if in vitro effect is observed for LSD1 inhib. for a particular type of haematological malignancy, follow up studies will be performed using mouse models to test if disease responds to LSD1 inhib. in vivo. Readouts will be altered extent of donor:recipient chimerism in bone marrow aspirates of transplanted mice, differential survival and altered proliferation, apoptosis and/or differentiation of transplanted leukaemia cells, either at autopsy or in bone marrow aspirates from living mice. Dosing approaches to be used will include intermittant dosing by oral gavage or by ip injection or continuous dosing by osmotic mini- pump or simply by adding compound to the food or water. _x000D_ As ORY1001has successfully passed the Preclinical regulatory tox, we will test safety, PD and PK of ORY1001 in a phase I clinical trial as described in 2.5.2._x000D__x000D__x000D__x000D_
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Acronym
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EPILETH
(Reference Number: 8159)
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Duration
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01/07/2013 - 31/12/2015
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Project Topic
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Current therapeutics target only proliferating leukemic cells, and not the more chemoresistant LSC. Aberrant epigenetic regulation contributes to the heterogeneity of the LSC compartment in AML. We propose to explore the strategy of hitting LSC by inhibition of LSD1 and to test it in humans.
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Network
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Eurostars
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Call
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Eurostars Cut-Off 10
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Project partner
