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Frontiers in Oncology 2022Acute myeloid leukemia (AML) is a hematologic malignancy. The overall prognosis is poor and therapeutic strategies still need to be improved. Studies have found that...
Acute myeloid leukemia (AML) is a hematologic malignancy. The overall prognosis is poor and therapeutic strategies still need to be improved. Studies have found that abnormalities in metabolisms promote the survival of AML cells. In recent years, an increasing number of studies have reported the effectiveness of a protein synthesis inhibitor, homoharringtonine (HHT), for the treatment of AML. In this study, we demonstrated that HHT effectively inhibited AML cells, especially MV4-11, a cell line representing human AML carrying the poor prognostic marker FLT3-ITD. We analyzed the transcriptome of MV4-11 cells treated with HHT, and identified the affected metabolic pathways including the choline metabolism process. In addition, we generated a line of MV4-11 cells that were resistant to HHT. The transcriptome analysis showed that the resistant mechanism was closely related to the ether lipid metabolism pathway. The key genes involved in these processes were , , and by multiple intergroup comparison and Venn analysis. In conclusion, we found that the treatment of HHT significantly changed metabolic signatures of AML cells, which may contribute to the precise clinical use of HHT and the development of novel strategies to treat HHT-resistant AML.
PubMed: 35774129
DOI: 10.3389/fonc.2022.931527 -
RSC Advances Dec 2019Three HS/NO-donating artemisinin derivatives were designed and synthesized. Their antiproliferative activities were evaluated against human acute myeloid leukemia (AML)...
Three HS/NO-donating artemisinin derivatives were designed and synthesized. Their antiproliferative activities were evaluated against human acute myeloid leukemia (AML) cell lines of K562 and K562/ADR and human normal liver cells of LO2. Biological evaluation indicated that NO-donating compound 10c exhibited the most potent cytotoxicity against leukemia cells, similar to the bioactivity of clinical drug of homoharringtonine, but showed less toxicity than homoharringtonine against LO2 cells. Further mechanism studies revealed that 10c could enhance the levels of intracellular NO and ROS, induce apoptosis and S phase cell cycle arrest, and disturb the mitochondrial membrane potential in K562 and K562/ADR cells. Western blot results demonstrated that 10c noticeably promoted autophagy by up-regulating the levels of Beclin1 and L3-II expression, inhibited the AKT signaling, and stimulated the AMPK and JNK signaling in both leukemia cell lines. Overall, 10c exhibited the potential to be a promising candidate for the therapy of AML.
PubMed: 35492518
DOI: 10.1039/c9ra08239e -
Clinical Cancer Research : An Official... Jul 2019Acute myeloid leukemia (AML) is a hematologic malignancy characterized by the accumulation of immature myeloid precursor cells. AML is poorly responsive to conventional...
PURPOSE
Acute myeloid leukemia (AML) is a hematologic malignancy characterized by the accumulation of immature myeloid precursor cells. AML is poorly responsive to conventional chemotherapy and a diagnosis of AML is usually fatal. More effective and less toxic forms of therapy are desperately needed. AML cells are known to be highly dependent on the amino acid glutamine for their survival. These studies were directed at determining the effects of glutaminase inhibition on metabolism in AML and identifying general weaknesses that can be exploited therapeutically.
EXPERIMENTAL DESIGN
AML cancer cell lines, primary AML cells, and mouse models of AML and acute lymphoblastic leukemia (ALL) were utilized.
RESULTS
We show that blocking glutamine metabolism through the use of a glutaminase inhibitor (CB-839) significantly impairs antioxidant glutathione production in multiple types of AML, resulting in accretion of mitochondrial reactive oxygen species (mitoROS) and apoptotic cell death. Moreover, glutaminase inhibition makes AML cells susceptible to adjuvant drugs that further perturb mitochondrial redox state, such as arsenic trioxide (ATO) and homoharringtonine (HHT). Indeed, the combination of ATO or HHT with CB-839 exacerbates mitoROS and apoptosis, and leads to more complete cell death in AML cell lines, primary AML patient samples, and using mouse models of AML. In addition, these redox-targeted combination therapies are effective in eradicating ALL cells and .
CONCLUSIONS
Targeting glutamine metabolism in combination with drugs that perturb mitochondrial redox state represents an effective and potentially widely applicable therapeutic strategy for treating multiple types of leukemia.
Topics: Animals; Antineoplastic Agents; Apoptosis; Cell Line, Tumor; Cell Proliferation; Cell Survival; Disease Models, Animal; Energy Metabolism; Glutamine; Humans; Leukemia; Mice; Mice, Transgenic; Molecular Targeted Therapy; Oxidation-Reduction; Reactive Oxygen Species; Xenograft Model Antitumor Assays
PubMed: 30940653
DOI: 10.1158/1078-0432.CCR-18-3223 -
Experimental Hematology May 2020Inhibition of the H3K79 histone methyltransferase DOT1L has exhibited encouraging preclinical and early clinical activity in KMT2A (MLL)-rearranged leukemia, supporting...
Inhibition of the H3K79 histone methyltransferase DOT1L has exhibited encouraging preclinical and early clinical activity in KMT2A (MLL)-rearranged leukemia, supporting the development of combinatorial therapies. Here, we investigated two novel combinations: dual inhibition of the histone methyltransferases DOT1L and EZH2, and the combination with a protein synthesis inhibitor. EZH2 is the catalytic subunit in the polycomb repressive complex 2 (PRC2), and inhibition of EZH2 has been reported to have preclinical activity in KMT2A-r leukemia. When combined with DOT1L inhibition, however, we observed both synergistic and antagonistic effects. Interestingly, antagonistic effects were not due to PRC2-mediated de-repression of HOXA9. HOXA cluster genes are key canonical targets of both KMT2A and the PRC2 complex. The independence of the HOXA cluster from PRC2 repression in KMT2A-r leukemia thus affords important insights into leukemia biology. Further studies revealed that EZH2 inhibition counteracted the effect of DOT1L inhibition on ribosomal gene expression. We thus identified a previously unrecognized role of DOT1L in regulating protein production. Decreased translation was one of the earliest effects measurable after DOT1L inhibition and specific to KMT2A-rearranged cell lines. H3K79me2 chromatin immunoprecipitation sequencing patterns over ribosomal genes were similar to those of the canonical KMT2A-fusion target genes in primary AML patient samples. The effects of DOT1L inhibition on ribosomal gene expression prompted us to evaluate the combination of EPZ5676 with a protein translation inhibitor. EPZ5676 was synergistic with the protein translation inhibitor homoharringtonine (omacetaxine), supporting further preclinical/clinical development of this combination. In summary, we discovered a novel epigenetic regulation of a metabolic process-protein synthesis-that plays a role in leukemogenesis and affords a combinatorial therapeutic opportunity.
Topics: Cell Line, Tumor; Enhancer of Zeste Homolog 2 Protein; Epigenesis, Genetic; Gene Expression Regulation, Leukemic; Gene Rearrangement; Histone-Lysine N-Methyltransferase; Homeodomain Proteins; Humans; Leukemia, Myeloid, Acute; Myeloid-Lymphoid Leukemia Protein; Polycomb Repressive Complex 2; Protein Biosynthesis
PubMed: 32437908
DOI: 10.1016/j.exphem.2020.04.007 -
British Journal of Pharmacology Jan 2016Homoharringtonine (HHT) is a natural alkaloid isolated from various Cephalotaxus species. HHT has been used to treat acute myeloid leukaemia (AML), chronic myeloid...
BACKGROUND AND PURPOSE
Homoharringtonine (HHT) is a natural alkaloid isolated from various Cephalotaxus species. HHT has been used to treat acute myeloid leukaemia (AML), chronic myeloid leukaemia (CML), chronic lymphocyte leukaemia and myelodysplastic syndromes. Although HHT inhibits protein synthesis and promotes apoptosis of leukaemia cells in preclinical studies, its molecular target proteins remain unknown. The aim of this study was to identify target proteins of HHT.
EXPERIMENTAL APPROACH
We have synthesized a biotinylated affinity column and used it to identify targets of HHT and confirmed the results by MS and Western blots. We also examined the effects of HHT on the target protein and determined roles of the target protein in anti-leukaemia activities of HHT through Western blots, flow cytometry and retrovirus transfection.
KEY RESULTS
Myosin-9, a member of the myosin super-family, was identified as a direct interactor of HHT. Furthermore, HHT up-regulated the expression level of myosin-9 in both AML and CML cell lines in a time-dependent manner. Thus, HHT-induced apoptosis of leukaemia cells begins in 6 h and continues to increase for 24 h. There is a positive correlation between up-regulated myosin-9 expression level and increased percentage of apoptotic cells mediated by HHT. Overexpression of myosin-9 could increase the sensitivity of the leukaemia cells to the cytotoxicity of HHT and arrest cells in S and G2/M phases.
CONCLUSIONS AND IMPLICATIONS
Our results indicated that myosin-9 was the target protein of HHT and played an important role in the HHT-induced apoptosis of leukaemia cells.
Topics: Antineoplastic Agents, Phytogenic; Apoptosis; Cell Cycle Checkpoints; Cell Line, Tumor; Cell Proliferation; Chromatography, Affinity; Harringtonines; Homoharringtonine; Humans; Leukemia, Myeloid; Molecular Motor Proteins; Myosin Heavy Chains; Up-Regulation
PubMed: 26448459
DOI: 10.1111/bph.13359 -
Cell Transplantation 2023Allogeneic hematopoietic stem cell transplantation (HSCT) is an effective treatment for acute myeloid leukemia (AML). Pediatric patients with AML who relapse after HSCT...
Allogeneic hematopoietic stem cell transplantation (HSCT) is an effective treatment for acute myeloid leukemia (AML). Pediatric patients with AML who relapse after HSCT have an extremely poor prognosis. We performed a retrospective study of pediatric patients diagnosed with AML from August 2015 to October 2019 who were treated with HSCT. Kaplan-Meier analyses were used to evaluate overall survival (OS), event-free survival (EFS), and cumulative recurrence rate (CRR). Cox regression analysis was used to determine the association between the baseline characteristics and relapse. A total of 37 pediatric patients met the inclusion criteria. Twenty-eight (75.7%) patients survived, and 9 (24.3%) patients died. The OS rates of AML patients treated with HSCT were 89.2% ± 5.1%, 75.7% ± 7.1%, and 75.7% ± 7.1% at 1, 3, and 5 years, respectively, and the CRRs were 11.4% ± 5.4%, 24.7% ± 7.7%, and 33.1% ± 10.4% at 1, 3, and 5 years after HSCT, respectively; four of nine children who relapsed after transplantation died. Induction with etoposide rather than homoharringtonine and fungal infections could be high-risk factors for recurrence after transplantation. The association between homoharringtonine-based induction therapy and a low recurrence rate persisted after adjusting for age, sex, risk stratification, fusion genes, and fungal infections. This study clarifies the clinical features and poor prognosis of post-transplant relapse in pediatric AML and indicates the urgent need for effective therapy for patients who relapse after HSCT.
Topics: Humans; Child; Homoharringtonine; Induction Chemotherapy; Retrospective Studies; Hematopoietic Stem Cell Transplantation; Leukemia, Myeloid, Acute; Recurrence; Chronic Disease; Mycoses
PubMed: 37470325
DOI: 10.1177/09636897231183559 -
Oxidative Medicine and Cellular... 2022The prognosis of children with refractory acute myeloid leukemia (AML) is poor. Complete remission (CR) is not always achieved with current salvage chemotherapy regimens...
OBJECTIVE
The prognosis of children with refractory acute myeloid leukemia (AML) is poor. Complete remission (CR) is not always achieved with current salvage chemotherapy regimens before transplantation, and some patients have no chance of transplantation. Here, we aimed to describe a new regimen of conventional chemotherapy drugs (homoharringtonine, cladribine , and aclarubicin (HCA)) for refractory AML and its mechanism in vitro.
METHODS
We retrospectively collected the clinical data of 5 children with primary refractory AML using HCA as reinduction chemotherapy, and CR rates, adverse reactions, and disease-free survival (DFS) were analyzed. The effects of homoharringtonine, cladribine, and aclarubicin alone or in combination on the proliferation of HL60 and THP1 cells were analyzed by CCK-8 assay. Furthermore, CCK-8 was used to determine the effects of HCA, alone or in combination with apoptosis inhibitors, necroptosis inhibitors, ferroptosis inhibitors, or autophagy inhibitors, on the proliferation of HL60 and THP1 cells and to screen for possible HCA-mediated death pathways in AML cells. The pathway of HCA-mediated AML cell death was further verified by Hoechst/PI staining, flow cytometry, and Western blotting.
RESULTS
After 2 cycles of conventional chemotherapy, none of the 5 children with AML achieved CR and were then treated with the HCA regimen for two cycles, 4 of 5 achieved CR, and another child achieved CR with incomplete hematological recovery (CRi). After CR, 3 children underwent hematopoietic stem cell transplantation (HSCT), and only 2 of them received consolidation therapy. As of the last follow-up, all 5 patients had been in DFS for a range of 23 to 28 months. The inhibition rate of homoharringtonine, cladribine, and aclarubicin in combination on HL60 and THP1 cells was significantly greater than that of a single drug or a combination of two drugs. We found that inhibitors of apoptosis and necroptosis were able to inhibit HCA-mediated cell death but not ferroptosis or autophagy inhibitors. Compared with the control group, the number of apoptotic cells in the HCA group was significantly increased and could be reduced by an apoptosis inhibitor. Western blot results showed that PARP, caspase-3, and caspase-8 proteins were activated and cleaved in the HCA group, the expression of Bax was upregulated and that of Bcl-2 was downregulated. The expression of apoptosis-related proteins could be reversed by apoptosis inhibition. Compared with the control group, the expression levels of the necroptosis-related proteins RIP1, RIP3, and MLKL were downregulated in the HCA group but were not phosphorylated. The necroptosis inhibitor increased the expression of RIP1 but caused no significant changes in RIP3 and MLKL, and none were phosphorylated.
CONCLUSIONS
HCA, as a new regimen of conventional drugs, was a safe and efficacious reinduction salvage strategy in children with refractory AML before HSCT. HCA exhibits the synergistic growth inhibition of AML cells and induces cell death mainly through apoptosis.
Topics: Aclarubicin; Antineoplastic Combined Chemotherapy Protocols; Child; Cladribine; Granulocyte Colony-Stimulating Factor; Homoharringtonine; Humans; Leukemia, Myeloid, Acute; Retrospective Studies
PubMed: 35873796
DOI: 10.1155/2022/8212286 -
Oncology Reports Jan 2020Drug resistance to tyrosine kinase inhibitors (TKIs) is currently a clinical problem in patients with chronic myelogenous leukemia (CML). Homoharringtonine (HHT) is an...
Drug resistance to tyrosine kinase inhibitors (TKIs) is currently a clinical problem in patients with chronic myelogenous leukemia (CML). Homoharringtonine (HHT) is an approved treatment for adult patients with chronic‑ or accelerated‑phase CML who are resistant to TKIs and other therapies; however, the underlying mechanisms remain unclear. In the present study, HHT treatment demonstrated induction of apoptosis in imatinib‑resistant K562G cells by using MTS assay and western blotting, and BCR‑ABL protein was reduced. CHX chase assay revealed that HHT induced degradation of the BCR‑ABL protein, which could be reversed by autophagy lysosome inhibitors Baf‑A1 and CQ. Next, HHT treatment confirmed the induction of autophagy in K562G cells, and silencing the key autophagic proteins ATG5 and Beclin‑1 inhibited the degradation of the BCR‑ABL protein and cytotoxicity. In addition, autophagic receptor p62/SQSTM1(p62) participated during the autophagic degradation of BCR‑ABL induced by HHT, and this was confirmed by co‑immunoprecipitation, in which HHT enhanced the ubiquitination of the BCR‑ABL protein and promoted its binding to p62. In conclusion, HHT induced p62‑mediated autophagy in imatinib‑resistant CML K562G cells, thus promoting autophagic degradation of the BCR‑ABL protein and providing a novel strategy for the treatment of TKI‑resistant CML.
Topics: Antineoplastic Agents, Phytogenic; Autophagy; Cell Line, Tumor; Cell Proliferation; Drug Resistance, Neoplasm; Fusion Proteins, bcr-abl; Gene Expression Regulation, Neoplastic; Homoharringtonine; Humans; Imatinib Mesylate; K562 Cells; Leukemia, Myelogenous, Chronic, BCR-ABL Positive; Proteolysis; RNA-Binding Proteins; Signal Transduction
PubMed: 31789418
DOI: 10.3892/or.2019.7412 -
Clinical Cancer Research : An Official... Sep 2020Rhabdoid tumors are devastating pediatric cancers in need of improved therapies. We sought to identify small molecules that exhibit and efficacy against preclinical...
PURPOSE
Rhabdoid tumors are devastating pediatric cancers in need of improved therapies. We sought to identify small molecules that exhibit and efficacy against preclinical models of rhabdoid tumor.
EXPERIMENTAL DESIGN
We screened eight rhabdoid tumor cell lines with 481 small molecules and compared their sensitivity with that of 879 other cancer cell lines. Genome-scale CRISPR-Cas9 inactivation screens in rhabdoid tumors were analyzed to confirm target vulnerabilities. Gene expression and CRISPR-Cas9 data were queried across cell lines and primary rhabdoid tumors to discover biomarkers of small-molecule sensitivity. Molecular correlates were validated by manipulating gene expression. Subcutaneous rhabdoid tumor xenografts were treated with the most effective drug to confirm results.
RESULTS
Small-molecule screening identified the protein-translation inhibitor homoharringtonine (HHT), an FDA-approved treatment for chronic myelogenous leukemia (CML), as the sole drug to which all rhabdoid tumor cell lines were selectively sensitive. Validation studies confirmed the sensitivity of rhabdoid tumor to HHT was comparable with that of CML cell lines. Low expression of the antiapoptotic gene , which encodes Bcl-XL, was the strongest predictor of HHT sensitivity, and HHT treatment consistently depleted Mcl-1, the synthetic-lethal antiapoptotic partner of Bcl-XL. Rhabdoid tumor cell lines and primary-tumor samples expressed low , and overexpression of induced resistance to HHT in rhabdoid tumor cells. Furthermore, HHT treatment inhibited rhabdoid tumor cell line and patient-derived xenograft growth .
CONCLUSIONS
Rhabdoid tumor cell lines and xenografts are highly sensitive to HHT, at least partially due to their low expression of . HHT may have therapeutic potential against rhabdoid tumors.
Topics: Animals; Apoptosis; Cell Line, Tumor; Cell Proliferation; Drug Resistance, Neoplasm; Female; Gene Expression Regulation, Neoplastic; Homoharringtonine; Humans; Mice; Protein Biosynthesis; Rhabdoid Tumor; Xenograft Model Antitumor Assays; bcl-X Protein
PubMed: 32631955
DOI: 10.1158/1078-0432.CCR-19-2717 -
Molecular Oncology Jul 2023Bromodomain-containing protein 4 (BRD4) inhibitors have been clinically developed to treat acute myeloid leukemia (AML), but their application is limited by the...
Bromodomain-containing protein 4 (BRD4) inhibitors have been clinically developed to treat acute myeloid leukemia (AML), but their application is limited by the possibility of drug resistance, which is reportedly associated with the activation of the WNT/β-catenin pathway. Meanwhile, homoharringtonine (HHT), a classic antileukemia drug, possibly inhibits the WNT/β-catenin pathway. In this study, we attempted to combine a novel BRD4 inhibitor (ACC010) and HHT to explore their synergistic lethal effects in treating AML. Here, we found that co-treatment with ACC010 and HHT synergistically inhibited cell proliferation, induced apoptosis, and arrested the cell cycle in FMS-like tyrosine kinase 3-internal tandem duplication (FLT3-ITD)-positive AML cells in vitro, and significantly inhibiting AML progression in vivo. Mechanistically, ACC010 and HHT cooperatively downregulated MYC and inhibited FLT3 activation. Further, when HHT was added, ACC010-resistant cells demonstrated a good synergy. We also extended our study to the mouse BaF3 cell line with FLT3-inhibitor-resistant FLT3-ITD/tyrosine kinase domain mutations and AML cells without FLT3-ITD. Collectively, our results suggested that the combination treatment of ACC010 and HHT might be a promising strategy for AML patients, especially those carrying FLT3-ITD.
Topics: Animals; Mice; Apoptosis; beta Catenin; Cell Line, Tumor; fms-Like Tyrosine Kinase 3; Homoharringtonine; Leukemia, Myeloid, Acute; Mutation; Nuclear Proteins; Protein Kinase Inhibitors; Transcription Factors; Humans
PubMed: 36567628
DOI: 10.1002/1878-0261.13368