Leukemic Stem Cells Research Articles

Cooperative CAR targeting to selectively eliminate AML and minimize escape

Acute myeloid leukemia (AML) poses a singular challenge for chimeric antigen receptor (CAR) therapy owing to its phenotypic heterogeneity and similarity to normal hematopoietic stem/progenitor cells (HSPCs). Here we expound a CAR strategy intended to efficiently target AML while minimizing HSPC toxicity. Quantification of target expression in relapsed/refractory patient samples and normal HSPCs reveals a therapeutic window for gated co-targeting of ADGRE2 and CLEC12A: We combine an attenuated ADGRE2-CAR with a CLEC12A-chimeric costimulatory receptor (ADCLEC.syn1) to preferentially engage ADGRE2posCLEC12Apos leukemic stem cells over ADGRE2lowCLEC12Aneg normal HSPCs. ADCLEC.syn1 prevents antigen escape in AML xenograft models, outperforms the ADGRE2-CAR alone and eradicates AML despite proximate myelopoiesis in humanized mice. Off-target HSPC toxicity is similar to that of a CD19-CAR and can be mitigated by reducing CAR Tcell-derived interferon-γ. Overall, we demonstrate the ability of target density-adapted cooperative CAR targeting to selectively eliminate AML and potentially obviate the need for hematopoietic rescue.

Current Approach in the Management of Secondary Immunodeficiency in Patients with Hematological Malignancies: Spanish Expert Consensus Recommendations.

A Delphi-based survey was designed to assess the opinions of clinical hematologists (n = 17) and clinical immunologists (n = 18) from across Spain on secondary immunodeficiencies (SID) in the management of oncohematological patients. There was 100% agreement on the need to have available guidelines for the management of immunodeficiency in hematological patients; to perform a baseline immunological evaluation in patients with chronic lymphocytic leukemia (CLL), multiple myeloma (MM), lymphoma and hematopoietic stem cell transplantation (HSCT) recipients; and to quantify serum IgG, IgA and IgM levels when SID is suspected. More than 90% agreed on the need for active immunization against seasonal influenza and H1N1, pneumococcus and Haemophilus influenzae. There was a consensus on the monitoring of IgG levels every 3 months (83%) and the need to have available a clinical protocol for the use of IVIG in the management of SID (94%), to monitor trough IgG levels to determine the correct IVIG dose (86%) and to discontinue IVIG after the recovery of IgG levels after 12 months of follow-up (77%). The findings of the present survey may be useful recommendations for hematologists and immunologists to improve the management of SID in daily practice.

A Deeply Quiescent Subset of CML LSC depend on FAO yet Avoid Deleterious ROS by Suppressing Mitochondrial Complex I.

Disease relapse and therapy resistance remain serious impediments to treating cancer. Leukemia stem cells (LSC) are therapy resistant and the cause of relapse. A state of deep quiescence appears to enable cancer stem cells (CSC) to acquire new somatic mutations essential for disease progression and therapy resistance. Both normal hematopoietic stem cells (HSC) and LSC share many common features, thereby complicating the safe elimination of LSC. A recent study demonstrated that long lived normal oocytes exist without mitochondrial complex I (MC-1), expressing it in a developmentally regulated fashion, thereby mitigating their vulnerability to ROS. Quiescent CSC rely on mitochondrial FAO, without complex I expression, thereby avoiding the generation of damaging ROS, similar to long lived normal human stem cells. A deeper understanding of the biology of therapy resistance is important for the development of optimal strategies to attain complete leukemia cures. Here, using scRNA-sequencing and ATAC-seq on primary chronic myelogenous leukemia (CML) patient samples, combined with bioinformatics analyses, we further examine the heterogeneity of a previously characterized in vitro imatinib-selected CD34-CD38- CML LSC population. We utilized a series of functional analyses, including single-cell metabolomic and Seahorse analyses, to validate the existence of the deepest quiescent leukemia initiators (LI) subset. Current study revealed heterogeneity of therapy resistant LSC in CML patients and their existence of two functionally distinct states. The most deeply quiescent LI suppress the expression of MC-1, yet are highly dependent on fatty acid oxidation (FAO) for their metabolic requirements and ATAC-seq demonstrated increased chromatin accessibility in this population, all consistent with an extremely primitive, quiescent stemness transcriptional signature. Importantly, the specific CREB binding protein (CBP)/β-catenin antagonist ICG-001 initiates the differentiation of LSC, including LI, decreases chromatin accessibility with differentiation and increasing expression of MC-1, CD34, CD38 and BCR-ABL1, thereby resensitizing them to imatinib. We investigated the biological aspects related to LSC heterogeneity in CML patients and demonstrated the ability of specific small molecule CBP/β-catenin antagonists to safely eliminate deeply quiescent therapy resistant CSC. These observations may represent an attractive generalizable therapeutic strategy that could help develop better protocols to eradicate the quiescent LSC population.

An oral triple pill-based cocktail effectively controls acute myeloid leukemia with high translation

Acute myeloid leukemia (AML) is a deadly hematological malignancy characterized by oncogenic translational addiction that results in over-proliferation and apoptosis evasion of leukemia cells. Various chemo- and targeted therapies aim to reverse this hallmark, but most show only modest efficacy. Here we report a single oral pill containing a low-dose triple small molecule-based cocktail, a highly active anti-cancer therapy (HAACT) with unique mechanisms that can effectively control AML. The cocktail comprises oncogenic translation inhibitor HHT, drug efflux pump P-gpi ENC and anti-apoptotic protein Bcl-2i VEN. Mechanistically, the cocktail can potently kill both leukemia stem cells (LSC) and bulk leukemic cells via co-targeting oncogenic translation, apoptosis machinery, and drug efflux pump, resulting in deep and durable remissions of AML in diverse model systems. We also identified EphB4/Bcl-xL as the cocktail response biomarkers. Collectively, our studies provide proof that a single pill containing a triple combination cocktail might be a promising avenue for AML therapy.

First-in-Human Phase I Trial Combining Biologically Guided Radioimmunotherapy (RIT) Using a 90Y-Anti-CD25 Monoclonal Antibody (Mab) with CT-guided Total Marrow and Lymphoid Irradiation (TMLI) in Relapsed and Refractory (R/R) Acute Leukemia

Patients with R/R acute leukemia after allogeneic hematopoietic cell transplant (alloHCT) have a dismal prognosis with 3-year survival rates of < 20%. To improve outcomes, innovative targeted forms of organ sparing radiotherapy, such as tumor-specific RIT and TMLI, are needed to dose escalate with acceptable toxicities, especially in patients ≥ age 60 years who cannot tolerate total body irradiation (TBI) / myeloablative regimens and who have a poor prognosis. CD25 is an ideal RIT target given its expression in acute leukemias, association with poor prognosis, and expression by leukemia stem cells. In this phase I trial (NCT05139004) we hypothesized that combining dose escalated 90Y-anti-CD25 RIT with fixed dose TMLI 12 Gy, fludarabine (flu), and melphalan (mel) in patients with R/R disease is safe and associated with acceptable toxicities. The primary objective of this trial is to determine the maximum tolerated dose and recommended phase 2 dose of 90Y-anti-CD25 Mab (Day -15) with 12 Gy TMLI (1.5 Gy twice a day, days -8 to -5), flu (30 mg/m2/d days -5 to -2), and mel (100 mg/m2, day -2) in patients ≥ 60 years old or with a HCT-comorbidity index ≥ 2 and with R/R AML, ALL or myelodysplastic syndrome (MDS) scheduled to undergo alloHCT from a matched donor. TMLI mean organ dose constraints for kidney, lung and liver were 4 Gy. Planned dose levels of 90Y-anti-CD25 were 0.3, 0.4, and 0.5 mCi/kg. 111In-anti-CD25 (5 mCi) was co-infused followed by serial nuclear scans to assess dosimetry and biodistribution. To date 5 patients (ages 31-74) with R/R AML have been treated. Marrow and circulating blasts ranged from 10-36% and 9-44%, respectively. For the 3 patients at 0.3 mCi/kg, follow-up ranged from 89-191+ days. 90Y/111In-anti-CD25 nuclear scans demonstrated persistent uptake in bone out to 144 hours, which was associated with a decline in circulating blasts. After combined RIT and TMLI, mean doses (Gy) to lungs ranged from 5.7-6.5, to kidneys from 7.5-8.2 and to liver from 7.2-11.6. No dose-limiting toxicities (DLT) were observed. All 3 patients achieved CR on day +30 bone marrow biopsies and 2 remained in CR on day +90 biopsies. Two patients have recently been treated at the 0.4 mCi/kg dose level. The results of patients treated at the higher dose levels will be provided. Dose escalation by adding 90Y-anti-CD25 RIT at 0.3 mCi/kg to 12 Gy TMLI was safe, including in older patients, with no dose-limiting toxicities, mean critical organ doses lower than conventional myeloablative TBI, and encouraging response rates. The toxicity profile and dose estimates at 0.3 mCi/kg predict that the planned higher dose levels will also be feasible with acceptable toxicities. RIT and TMLI are complementary and when combined address the limitations of each modality. Combining these targeted therapies may be a superior strategy to intensify dose to leukemia compared to dose escalation of either modality alone.

Twist family BHLH transcription factor 1 is required for the maintenance of leukemia stem cell in MLL-AF9+ acute myeloid leukemia.

Leukemia stem cells (LSC) are a rare population capable of limitless self-renewal and are responsible for the initiation, maintenance, and relapse of leukemia. Elucidation of the mechanisms underlying the regulation of LSC function could provide novel treatment strategies. Here, we show that TWIST1 is extremely highly expressed in the LSC of MLL-AF9+ acute myeloid leukemia (AML), and its upregulation is positively regulated by KDM4C in a H3K9me3 demethylation-dependent manner. We further demonstrate that TWIST1 is essential for the viability, dormancy, and self-renewal capacities of LSC, and that it promotes the initiation and maintenance of MLL-AF9-mediated AML. In addition, TWIST1 directly interacts and collaborates with HOXA9 in inducing AML in mice. Mechanistically, TWIST1 exerts its oncogenic function by activating the WNT5a/RAC1 axis. Collectively, our study uncovers a critical role of TWIST1 in LSC function and provides new mechanistic insights into the pathogenesis of MLL-AF9+ AML.

Engineered mesenchymal stem cell exosomes loaded with miR-34c-5p selectively promote eradication of acute myeloid leukemia stem cells

Most patients with acute myeloid leukemia (AML) relapse eventually because of the inability to effectively eliminate leukemia stem cells (LSCs), prompting the search of new therapies to eradicate LSCs. Our previous study demonstrated that miR-34c-5p promotes the clearance of LSCs in an AML mouse model, highlighting its potential as a therapeutic target for eradicating LSCs, but the effective delivery of miR-34c-5p to LSCs remains a great challenge. Here, we employed simultaneous two-step modifications to engineer mesenchymal stem cells (MSCs) and MSC-derived exosomes to create exosomes overexpressing the fused protein lysosome-associated membrane protein 2-interleukin 3 (Lamp2b-IL3) and hematopoietic cell E-selectin/L-selectin ligand (HCELL), and demonstrated that the engineered exosomes exhibited an enhanced ability for bone marrow homing and selective targeting of LSCs. Additionally, using a humanized AML mouse model, we confirmed that the engineered exosomes, loaded with miR-34c-5p, could selectively promote eradication of LSCs and impede the AML development in vivo. In summary, we successfully designed an effective delivery system and provided new insights into the development of novel therapies for delivering miRNA or other molecules to LSCs with greater cellular targeting specificity.

Recent advances in therapies for primary myelofibrosis.

Primary myelofibrosis (PMF), polycythemia vera (PV) and essential thrombocythemia (ET) form the classical BCR-ABL1-negative myeloproliferative neoplasms (MPNs) that are driven by a constitutive activation of JAK2 signaling. PMF as well as secondary MF (post-ET and post-PV MF) are the most aggressive MPNs. Presently, there is no curative treatment, except allogenic hematopoietic stem cell transplantation. JAK inhibitors, essentially ruxolitinib, are the therapy of reference for intermediate and high-risk MF. However, presently the current JAK inhibitors behave mainly as anti-inflammatory drugs, improving general symptoms and spleen size without major impact on disease progression. A better understanding of the genetics of MF, the biology of its leukemic stem cells (LSCs), the mechanisms of fibrosis and of cytopenia and the role of inflammatory cytokines has led to new approaches with the development of numerous therapeutic agents that target epigenetic regulation, telomerase, apoptosis, cell cycle, cytokines and signaling. Furthermore, the use of a new less toxic form of interferon-α has been revived, as it is presently one of the only molecules that targets the mutated clone. These new approaches have different aims: (a) to provide alternative therapy to JAK inhibition; (b) to correct cytopenia; and (c) to inhibit fibrosis development. However, the main important goal is to find new disease modifier treatments, which will profoundly modify the progression of the disease without major toxicity. Presently the most promising approaches consist of the inhibition of telomerase and the combination of JAK2 inhibitors (ruxolitinib) with either a BCL2/BCL-xL or BET inhibitor. Yet, the most straightforward future approaches can be considered to be the development of and/or selective inhibition of JAK2V617F and the targeting MPL and calreticulin mutants by immunotherapy. It can be expected that the therapy of MF will be significantly improved in the coming years.

Identification and validation of a prognostic risk-scoring model based on the level of TIM-3 expression in acute myeloid leukemia

Acute myeloid leukemia (AML) is characterized by an unfavorable prognosis due to the presence of self-renewing leukemic stem cells (LSCs). The presence of T-cell immunoglobulin mucin-3 (TIM-3) on the surface of LSCs has been observed in various types of human AML, exerting an impact on the prognostic outcome. Exploring the hub genes associated with varying levels of TIM-3 expression offers a valuable approach to enhance our understanding of the underlying mechanisms involving TIM-3 and to identify potential prognostic indicators in AML. Nevertheless, to date, no research studies have reported a prognostic model that relies on the level of TIM-3 expression. In our study, we screen the hub-genes based on different expression level of TIM-3 through WGCNA. The prognostic risk-scoring model was constructed based on hub-genes. The results show the risk prognostic model has extraordinary ability to predict prognosis in both the training and validation sets. The high-risk group present poor prognosis with mutation of NPM1, TP53 (Multiple Hit) and FLT3(multiple hit), while IDH2 (Missense Mutation), MUC16 (Multiple Hit/Missense Mutation) occur mutation in low-risk group presenting favorite prognosis than high-risk group. Leukocyte cell–cell adhesion, regulation of T cell activation and I-κB kinase/NF-κB signaling enriched in high-risk group, involving in HSCs or LSCs anchoring to BM, which implicated in LSCs survival and chemotherapy resistance. B7-H3 (CD276) and CD276 would be the potential immune targets in high-risk group. The risk score model may help in distinguishing immune and molecular characteristics, predicting patient outcomes.

Ratio of stemness to interferon signalling as a biomarker and therapeutic target of myeloproliferative neoplasm progression to acute myeloid leukaemia.

Progression to aggressive secondary acute myeloid leukaemia (sAML) poses a significant challenge in the management of myeloproliferative neoplasms (MPNs). Since the physiopathology of MPN is closely linked to the activation of interferon (IFN) signalling and that AML initiation and aggressiveness is driven by leukaemia stem cells (LSCs), we investigated these pathways in MPN to sAML progression. We found that high IFN signalling correlated with low LSC signalling in MPN and AML samples, while MPN progression and AML transformation were characterized by decreased IFN signalling and increased LSC signature. A high LSC to IFN expression ratio in MPN patients was associated with adverse clinical prognosis and higher colony forming potential. Moreover, treatment with hypomethylating agents (HMAs) activates the IFN signalling pathway in MPN cells by inducing a viral mimicry response. This response is characterized by double-stranded RNA (dsRNA) formation and MDA5/RIG-I activation. The HMA-induced IFN response leads to a reduction in LSC signature, resulting in decreased stemness. These findings reveal the frequent evasion of viral mimicry during MPN-to-sAML progression, establish the LSC-to-IFN expression ratio as a progression biomarker, and suggests that HMAs treatment can lead to haematological response in murine models by re-activating dsRNA-associated IFN signalling.

Ppm1d truncating mutations promote the development of genotoxic stress-induced AML.

Hematopoietic stem cells (HSCs) ensure blood cell production during the life-time of an organism, and to do so they need to balance self-renewal, proliferation, differentiation, and migration in a steady state as well as in response to stress or injury. Importantly, aberrant proliferation of HSCs leads to hematological malignancies, and thus, tight regulation by various tumor suppressor pathways, including p53, is essential. Protein phosphatase magnesium-dependent 1 delta (PPM1D) is a negative regulator of p53 and promotes cell survival upon induction of genotoxic stress. Truncating mutations in the last exon of PPM1D lead to the production of a stable, enzymatically active protein and are commonly associated with clonal hematopoiesis. Using a transgenic mouse model, we demonstrate that truncated PPM1D reduces self-renewal of HSCs in basal conditions but promotes the development of aggressive AML after exposure to ionizing radiation. Inhibition of PPM1D suppressed the colony growth of leukemic stem and progenitor cells carrying the truncated PPM1D, and remarkably, it provided protection against irradiation-induced cell growth. Altogether, we demonstrate that truncated PPM1D affects HSC maintenance, disrupts normal hematopoiesis, and that its inhibition could be beneficial in the context of therapy-induced AML.

Cytokine profile in patients with chronic myeloid leukemia

Resistance to tyrosine kinase inhibitors (TKIs) is currently an important clinical problem in the management of patients with chronic myeloid leukemia (CML). Recent studies suggested that aberrant cytokine secretion may be among the BCR/ABL-independent mechanisms of resistance, thus contributing to the persistence of leukemic stem cells in spite of continuous targeted therapy. The aim of the study was to evaluate concentration of cytokines in the serum of patients with CML depending on the efficiency of therapy.Quantitative determination of the cytokines (TNFα, IL-1β, IL-2, IL-4, IL-6, IL-10, IL-17, IL-18, IFNα and VEGF) in blood serum of patients with chronic-phase CML (n = 84) and healthy subjects (n = 30) was performed using enzyme immunoassay (ELISA). The patients with CML were divided into 3 groups depending on the duration of therapy: group I, newly diagnosed patients (n = 10); group II, patients receiving therapy for &lt; 12 months (n = 10); group III included patients receiving therapy for more than 12 months (n = 64).The results of our study showed that cytokine concentration among CML patients significantly differed, depending on the duration of therapy. Significantly higher concentration of IL-17, IL-6, IL-1β, IL-10, IL-18, IL-2 and TNFα was found in group I compared with control group. Group II patients also demonstrated significantly higher concentrations of TNFα, IL-6, IL-10, IL-18 and IFNα by comparison with control group, as well as higher concentration of IFNα compared with in groups I and III. In group III, concentrations of IL-17, IL-1β, TNFα, IL-6, IL-10, IL-18 were significantly higher than in control group. When compared with group I, it was found that concentrations of IL-1β, IL-2 and IL-18 were significantly lower. A direct correlation was found between expression levels of chimeric BCR/ABL gene, (a marker of CML malignancy), and concentrations of IL-1β and IL-17. ROC-analysis demonstrated high-quality models which showed an association between achievement of major molecular response (MMR) and low serum concentrations of IL-1β, IL-6 and IL-17.Hence, the results of our study have shown that determination of IL-1β, IL-6 and IL-17 concentrations may be a prognostic marker for assessing the efficiency of therapy and probability of achieving MMR in CML.

Acquired miR-142 deficit in leukemic stem cells suffices to drive chronic myeloid leukemia into blast crisis

The mechanisms underlying the transformation of chronic myeloid leukemia (CML) from chronic phase (CP) to blast crisis (BC) are not fully elucidated. Here, we show lower levels of miR-142 in CD34+CD38− blasts from BC CML patients than in those from CP CML patients, suggesting that miR-142 deficit is implicated in BC evolution. Thus, we create miR-142 knockout CML (i.e., miR-142−/−BCR-ABL) mice, which develop BC and die sooner than miR-142 wt CML (i.e., miR-142+/+BCR-ABL) mice, which instead remain in CP CML. Leukemic stem cells (LSCs) from miR-142−/−BCR-ABL mice recapitulate the BC phenotype in congenic recipients, supporting LSC transformation by miR-142 deficit. State-transition and mutual information analyses of “bulk” and single cell RNA-seq data, metabolomic profiling and functional metabolic assays identify enhanced fatty acid β-oxidation, oxidative phosphorylation and mitochondrial fusion in LSCs as key steps in miR-142-driven BC evolution. A synthetic CpG-miR-142 mimic oligodeoxynucleotide rescues the BC phenotype in miR-142−/−BCR-ABL mice and patient-derived xenografts.

Recent Advances in Characterization of Pre-Leukemic/Leukemic Stem Cells in Acute Myeloid Leukemia

Recent Advances in Characterization of Pre-Leukemic/Leukemic Stem Cells in Acute Myeloid Leukemia

Single-cell multi-omics identifies chronic inflammation as a driver of TP53-mutant leukemic evolution

Understanding the genetic and nongenetic determinants of tumor protein 53 (TP53)-mutation-driven clonal evolution and subsequent transformation is a crucial step toward the design of rational therapeutic strategies. Here we carry out allelic resolution single-cell multi-omic analysis of hematopoietic stem/progenitor cells (HSPCs) from patients with a myeloproliferative neoplasm who transform to TP53-mutant secondary acute myeloid leukemia (sAML). All patients showed dominant TP53 ‘multihit’ HSPC clones at transformation, with a leukemia stem cell transcriptional signature strongly predictive of adverse outcomes in independent cohorts, across both TP53-mutant and wild-type (WT) AML. Through analysis of serial samples, antecedent TP53-heterozygous clones and in vivo perturbations, we demonstrate a hitherto unrecognized effect of chronic inflammation, which suppressed TP53 WT HSPCs while enhancing the fitness advantage of TP53-mutant cells and promoted genetic evolution. Our findings will facilitate the development of risk-stratification, early detection and treatment strategies for TP53-mutant leukemia, and are of broad relevance to other cancer types.

Single-cell transcriptomics reveals multiple chemoresistant properties in leukemic stem and progenitor cells in pediatric AML

BackgroundCancer patients can achieve dramatic responses to chemotherapy yet retain resistant tumor cells, which ultimately results in relapse. Although xenograft model studies have identified several cellular and molecular features that are associated with chemoresistance in acute myeloid leukemia (AML), to what extent AML patients exhibit these properties remains largely unknown.ResultsWe apply single-cell RNA sequencing to paired pre- and post-chemotherapy whole bone marrow samples obtained from 13 pediatric AML patients who had achieved disease remission, and distinguish AML clusters from normal cells based on their unique transcriptomic profiles. Approximately 50% of leukemic stem and progenitor populations actively express leukemia stem cell (LSC) and oxidative phosphorylation (OXPHOS) signatures, respectively. These clusters have a higher chance of tolerating therapy and exhibit an enhanced metabolic program in response to treatment. Interestingly, the transmembrane receptor CD69 is highly expressed in chemoresistant hematopoietic stem cell (HSC)-like populations (named the CD69+ HSC-like subpopulation). Furthermore, overexpression of CD69 results in suppression of the mTOR signaling pathway and promotion of cell quiescence and adhesion in vitro. Finally, the presence of CD69+ HSC-like cells is associated with unfavorable genetic mutations, the persistence of residual tumor cells in chemotherapy, and poor outcomes in independent pediatric and adult public AML cohorts.ConclusionsOur analysis reveals leukemia stem cell and OXPHOS as two major chemoresistant features in human AML patients. CD69 may serve as a potential biomarker in defining a subpopulation of chemoresistant leukemia stem cells. These findings have important implications for targeting residual chemo-surviving AML cells.

POSTER: AML-055 Correlation Between CD200 Expression on Leukemic Stem Cells and Response to Treatment in De Novo Adult Acute Myeloid Leukemia Patients

POSTER: AML-055 Correlation Between CD200 Expression on Leukemic Stem Cells and Response to Treatment in De Novo Adult Acute Myeloid Leukemia Patients

AML-055 Correlation Between CD200 Expression on Leukemic Stem Cells and Response to Treatment in De novo Adult Acute Myeloid Leukemia Patients

AML-055 Correlation Between CD200 Expression on Leukemic Stem Cells and Response to Treatment in De novo Adult Acute Myeloid Leukemia Patients

MPN-058 Diagnostic and Prognostic Utility of Flow Cytometric Enumeration of Aberrant hMICL–Expressing Circulating Leukemic Stem Cells in BCR-ABL1–Negative Myeloproliferative Neoplasms

MPN-058 Diagnostic and Prognostic Utility of Flow Cytometric Enumeration of Aberrant hMICL–Expressing Circulating Leukemic Stem Cells in BCR-ABL1–Negative Myeloproliferative Neoplasms

GPRC5C drives branched-chain amino acid metabolism in leukemogenesis

AbstractLeukemia stem cells (LSCs) share numerous features with healthy hematopoietic stem cells (HSCs). G-protein coupled receptor family C group 5 member C (GPRC5C) is a regulator of HSC dormancy. However, GPRC5C functionality in acute myeloid leukemia (AML) is yet to be determined. Within patient AML cohorts, high GPRC5C levels correlated with poorer survival. Ectopic Gprc5c expression increased AML aggression through the activation of NF-κB, which resulted in an altered metabolic state with increased levels of intracellular branched-chain amino acids (BCAAs). This onco-metabolic profile was reversed upon loss of Gprc5c, which also abrogated the leukemia-initiating potential. Targeting the BCAA transporter SLC7A5 with JPH203 inhibited oxidative phosphorylation and elicited strong antileukemia effects, specifically in mouse and patient AML samples while sparing healthy bone marrow cells. This antileukemia effect was strengthened in the presence of venetoclax and azacitidine. Our results indicate that the GPRC5C–NF-κB-SLC7A5–BCAAs axis is a therapeutic target that can compromise leukemia stem cell function in AML.