Project description:The histone demethylase LSD1 is deregulated in several tumors, including leukemias, providing the rationale for the clinical use of LSD1 inhibitors. In acute promyelocytic leukemia (APL), pharmacological doses of retinoic acid (RA) induce differentiation of APL cells, triggering degradation of the PML-RAR oncogene. APL cells are resistant to LSD1 inhibition or knockout, but targeting LSD1 sensitizes them to physiological doses of RA without altering of PML-RAR levels, and extends survival of leukemic mice upon RA treatment. The combination of RA with LSD1 inhibition (or knockout) is also effective in other non-APL, acute myeloid leukemia (AML) cells. Nonenzymatic activities of LSD1 are essential to block differentiation, while RA with targeting of LSD1 releases a differentiation gene expression program, not strictly dependent on changes in histone H3K4 methylation. Integration of proteomic/epigenomic/mutational studies showed that LSD1 inhibitors alter the recruitment of LSD1-containing complexes to chromatin, inhibiting the interaction between LSD1 and the transcription factor GFI1.
Project description:The histone demethylase LSD1 is deregulated in several tumors, including leukemias, providing the rationale for the clinical use of LSD1 inhibitors. In acute promyelocytic leukemia (APL), pharmacological doses of retinoic acid (RA) induce differentiation of APL cells through degradation of the PML-RAR oncogene. APL cells are resistant to LSD1 inhibition or knock-out, but LSD1 inhibition sensitizes them to physiological doses of RA without altering the stability of PML-RAR, and extends survival of leukemic mice upon RA treatment. Non-enzymatic activities of LSD1 are essential to block differentiation of leukemic cells, while the combination of LSD1 inhibitors (or LSD1 knock-out) with low doses of RA releases a differentiation-associated gene expression program, not strictly dependent on changes in histone H3K4 methylation (known substrate of LSD1). An integrated proteomic/epigenomic/mutational analysis showed that LSD1 inhibitors alter the recruitment of LSD1-containing complexes to chromatin through inhibition of the interaction between LSD1 and GFI1, a relevant transcription factor in hematopoiesis.
Project description:The histone demethylase LSD1 is deregulated in several tumors, including leukemias, providing the rationale for the clinical use of LSD1 inhibitors . In acute promyelocytic leukemia (APL), pharmacological doses of retinoic acid (RA) induce differentiation of APL cells through degradation of the PML-RAR oncogene. APL cells are resistant to LSD1 inhibition or knock-out, but LSD1 inhibition sensitizes them to physiological doses of RA without altering the stability of PML-RAR, and extends survival of leukemic mice upon RA treatment. Non-enzymatic activities of LSD1 are essential to block differentiation of leukemic cells, while the combination of LSD1 inhibitors (or LSD1 knock-out) with low doses of RA releases a differentiation-associated gene expression program, not strictly dependent on changes in histone H3K4 methylation (known substrate of LSD1). An integrated proteomic/epigenomic/mutational analysis showed that LSD1 inhibitors alter the recruitment of LSD1-containing complexes to chromatin through inhibition of the interaction between LSD1 and GFI1, a relevant transcription factor in hematopoiesis.
Project description:The histone demethylase LSD1 is deregulated in several tumors, including leukemias, providing the rationale for the clinical use of LSD1 inhibitors . In acute promyelocytic leukemia (APL), pharmacological doses of retinoic acid (RA) induce differentiation of APL cells through degradation of the PML-RAR oncogene. APL cells are resistant to LSD1 inhibition or knock-out, but LSD1 inhibition sensitizes them to physiological doses of RA without altering the stability of PML-RAR, and extends survival of leukemic mice upon RA treatment. Non-enzymatic activities of LSD1 are essential to block differentiation of leukemic cells, while the combination of LSD1 inhibitors (or LSD1 knock-out) with low doses of RA releases a differentiation-associated gene expression program, not strictly dependent on changes in histone H3K4 methylation (known substrate of LSD1). An integrated proteomic/epigenomic/mutational analysis showed that LSD1 inhibitors alter the recruitment of LSD1-containing complexes to chromatin through inhibition of the interaction between LSD1 and GFI1, a relevant transcription factor in hematopoiesis.
Project description:Acute promyelocytic leukemia (APL), a cytogenetically distinct subtype of acute myeloid leukemia (AML), characterized by the t(15;17)-associated PML-RARA fusion, has been successfully treated with therapy utilizing all-trans-retinoic acid (ATRA) to differentiate leukemic blasts. However, among patients with non-APL AML, ATRA-based treatment has not been effective. Here we show that, through epigenetic reprogramming, inhibitors of lysine-specific demethylase 1 (LSD1, also called KDM1A), including tranylcypromine (TCP), unlocked the ATRA-driven therapeutic response in non-APL AML. LSD1 inhibition did not lead to a large-scale increase in histone 3 Lys4 dimethylation (H3K4(me2)) across the genome, but it did increase H3K4(me2) and expression of myeloid-differentiation-associated genes. Notably, treatment with ATRA plus TCP markedly diminished the engraftment of primary human AML cells in vivo in nonobese diabetic (NOD)-severe combined immunodeficient (SCID) mice, suggesting that ATRA in combination with TCP may target leukemia-initiating cells. Furthermore, initiation of ATRA plus TCP treatment 15 d after engraftment of human AML cells in NOD-SCID ? (with interleukin-2 (IL-2) receptor ? chain deficiency) mice also revealed the ATRA plus TCP drug combination to have a potent anti-leukemic effect that was superior to treatment with either drug alone. These data identify LSD1 as a therapeutic target and strongly suggest that it may contribute to AML pathogenesis by inhibiting the normal pro-differentiative function of ATRA, paving the way for new combinatorial therapies for AML.
Project description:Targeting the scaffolding role of LSD1(KDM1A) poises acute myeloid leukemia cells for Retinoic Acid induced differentiation [ChIP-seq]
Project description:Targeting the scaffolding role of LSD1(KDM1A) poises acute myeloid leukemia cells for Retinoic Acid induced differentiation [RNA-seq]
Project description:This SuperSeries is composed of the following subset Series: GSE34672: Inhibition of the LSD1 (KDM1A) demethylase reactivates the all-trans-retinoic acid differentiation pathway in acute myeloid leukemia [Illumina HumanHT-12 gene expression array] GSE34725: Inhibition of the LSD1 (KDM1A) demethylase reactivates the all-trans-retinoic acid differentiation pathway in acute myeloid leukemia [ChIP-Seq] Refer to individual Series