Project description:Acute myeloid leukemia (AML) is characterized by the accumulation of immature leukemic blasts. The application of all-trans retinoic acid (ATRA) treatments have markedly transformed acute promyelocytic leukemia (APL, the M3 subtype of AML) to a highly manageable disease, and research strategies that seek to extend the application of ATRA-based treatment to other AML subtypes are an important area of investigation. Here, we found CASP1/GSDMD was lower expressed in APL and most other subtypes of primary de novo AML patients and increased in ATRA-treated APL cells. We showed that ATRA increased and activated CASP1 to trigger pyroptosis and differentiation of APL cells. Mechanistically, ATRA could induce CASP1 expression via IFNγ/STAT1 in APL and non-APL AML cells, while do not activate CASP1 in non-APL AML cells. Accordingly, pharmacological activation of CASP1 by Val-boroPro (DPP8/9 inhibitor) enhanced pyroptosis and differentiation induced by ATRA in AML cells. Moreover, the combination of ATRA and Val-boroPro enhanced anti-leukemia activity in primary AML cells. Our study demonstrates that the ATRA-mediated anti-leukemia effect requires a functional activated CASP1 and provides a highly attractive therapeutic strategy for the treatment of AML.
Project description:Preclinical studies have shown that combining the LSD1 inhibitor tranylcypromine (TCP) with all-trans retinoic acid (ATRA) induces differentiation and impairs survival in non-APL acute myeloid leukemia (AML). We conducted a Phase 1 clinical trial (NCT02273102) to evaluate the safety and preliminary activity of ATRA in combination with TCP in patients with relapsed/refractory AML and myelodysplasia (MDS). Seventeen patients (11 AML and 6 MDS) received ATRA-TCP therapy with ATRA (45 mg/m2 daily in divided doses) and TCP (3 dose levels: 10 mg twice-daily [BID], 20 mg BID, and 30 mg BID). ATRA-TCP had an acceptable safety profile. The maximum tolerated dose of TCP was 20 mg BID. There were 3 DLTs: dizziness (20 mg BID), asthenia (30 mg BID), and nausea/vomiting (30 mg BID). Best evaluable responses included 1 morphologic leukemia-free state (MLFS), 1 marrow complete remission (CR) with hematologic improvement, 2 stable disease with hematologic improvement, and 2 stable disease. In 13 response-evaluable patients, the overall response rate was 30.8% and clinical benefit rate 46.2%. Gene expression profiling of patient blasts showed that responding patients had a more dormant phenotype compared to non-responders at baseline. In human AML cell lines, we showed that treatment with ATRA-TCP increases differentiation capacity and/or cell death, and that ATRA-TCP regulates the in vitro expression of genes that segregate primary patients by their clinical response. These data indicate that LSD1 inhibition sensitizes AML cells to ATRA-induced differentiation and cell death and may restore clinical responsiveness in subsets of MDS and AML patients.
Project description:The BCL-2 family plays important roles in acute myeloid leukemia (AML) and Venetoclax, a selective BCL-2 inhibitor, has received FDA approval for treatment of AML. However, drug resistance ensues after prolonged treatment, highlighting the need for a greater understanding of the underlying mechanisms. Using a genome-wide CRISPR/Cas9 screen in human AML, we identified genes whose inactivation sensitizes AML blasts to Venetoclax. Genes involved in mitochondrial organization and function were significantly depleted throughout our screen, including the mitochondrial chaperonin CLPB. We demonstrated that CLPB is upregulated in human AML, it is further induced upon acquisition of Venetoclax resistance and its ablation sensitizes AML cells to Venetoclax. Mechanistically, CLPB maintains the mitochondrial cristae structure via its interaction with the cristae-shaping protein OPA1, whereas its loss promotes apoptosis by inducing cristae remodeling and mitochondrial stress responses. Overall, our data suggest that targeting mitochondrial architecture may provide a promising approach to circumvent Venetoclax resistance.
Project description:Proteome and phosphoproteome raw files from AML patient samples obtained before and after 3 and 8 days of ATRA/valproic acid treatment
Project description:Purpose: Treatment of acute promyelocytic leukemia (APL) with the retinoid, all trans retinoic acid (ATRA), along with standard chemotherapy has significantly improved survival compared to chemotherapy alone1. ATRA mediates its benefit in APL by overcoming the transcriptional block mediated by PML-RAR-alpha fusion oncoprotein, thereby, restoring expression of retinoid response genes2. The therapeutic benefits observed with ATRA treatment in APL have not been achieved in the other more common sub-types of acute myeloblastic leukemia (AML)3. This likely reflects the recruitment of histone deacetylase complexes by other recurrent chromosomal translocations in AML cells4. In this experiment, we evaluated if treatment of the AML cell line, OCI/AML-2, with the histone deacetylase inhibitor, valproic acid (VPA), would alter the expression of sub-sets of genes by itself or in conjunction with ATRA that have been shown to be modulated by ATRA in APL2. Keywords: other
Project description:Pyroptosis is a recently discovered form of lytic cell death that is characterized by cell swelling and formation of pores and large bubbles on the plasma membrane. We find radiation could induce pyroptosis in human colorectal cancer HCT116 cells, and irradiation induces pyroptosis in mouse normal intestine MODEK cells only after 36 hours and over 8.0 Gy. In view of the significant pyroptosis effect of MODE-K cells, we selected 4Gy and 12Gy, 24h and 48h for experiments. After ONT full-length transcriptome sequencing, the cell pyroptosis model can screen out the differential genes related to cell pyroptosis, which is helpful to further explore the mechanism of pyroptosis of MODE-K cells.
Project description:Depletion of CHD4 sensitizes AML cells but not normal CD34+ progenitors to genotoxic agents by relaxing chromatin and impairing DSB repair. Depletion of CHD4 modulates expression of AML cell genes that regulate tumor formation in vivo and colony formation in vitro.
Project description:Searching for new strategies of acute myeloid leukemia (AML) treatment is of particular interest. Cell lines, e. g. HL-60 and NB4, represent model systems to study molecular features of leukemic cells. The all-trans-retinoic acid (ATRA) has proven itself to be an effective treatment for one of AML subtypes, i.e., acute promyelocytic leukemia (APL). At the same time, ATRA causes granulocytic differentiation of non-APL leukemic cells in vitro. Combination of new therapeutics with ATRA could improve efficiency of treatment. Studying the proteome perturbation in leukemic cells under the ATRA treatment allows to determine potential regulatory molecules that could be affected pharmacologically. Thus, the TMT-based proteomic profiles of HL-60, NB4, and K562 cell lines under the ATRA treatment were obtained at 0, 3, 12, 24, and 72 h after the ATRA treatment.