Towards precision medicine for AML

Combined proteomics and CRISPR‒Cas9 screens in PDX identify ADAM10 as essential for leukemia in vivo

BACKGROUND

Acute leukemias represent deadly malignancies that require better treatment. As a challenge, treatment is counteracted by a microenvironment protecting dormant leukemia stem cells.

METHODS

To identify responsible surface proteins, we performed deep proteome profiling on minute numbers of dormant patient-derived xenograft (PDX) leukemia stem cells isolated from mice. Candidates were functionally screened by establishing a comprehensive CRISPR‒Cas9 pipeline in PDX models in vivo.

RESULTS

A disintegrin and metalloproteinase domain-containing protein 10 (ADAM10) was identified as an essential vulnerability required for the survival and growth of different types of acute leukemias in vivo, and reconstitution assays in PDX models confirmed the relevance of its sheddase activity. Of translational importance, molecular or pharmacological targeting of ADAM10 reduced PDX leukemia burden, cell homing to the murine bone marrow and stem cell frequency, and increased leukemia response to conventional chemotherapy in vivo.

CONCLUSIONS

These findings identify ADAM10 as an attractive therapeutic target for the future treatment of acute leukemias.

Intensive chemotherapy with or without gemtuzumab ozogamicin in patients with NPM1-mutated acute myeloid leukaemia (AMLSG 09-09): a randomised, open-label, multicentre, phase 3 trial

BACKGROUND

Acute myeloid leukaemia with mutated NPM1 is associated with high CD33 expression and intermediate-risk cytogenetics. The aim of this study was to evaluate intensive chemotherapy with or without the anti-CD33 antibody-drug conjugate gemtuzumab ozogamicin in participants with newly diagnosed, NPM1-mutated acute myeloid leukaemia.

METHODS

This open-label, phase 3 trial was conducted at 56 hospitals in Germany and Austria. Eligible participants were 18 years or older and had newly diagnosed NPM1-mutated acute myeloid leukaemia and an Eastern Cooperative Oncology Group performance status of 0-2. Participants were randomly assigned, using age as a stratification factor (18-60 years vs >60 years), 1:1 to the two treatment groups using allocation concealment; there was no masking of participants and investigators to treatment groups. Participants received two cycles of induction therapy (idarubicin, cytarabine, and etoposide) plus all-trans retinoic acid (ATRA) followed by three consolidation cycles of high-dose cytarabine (or an intermediate dose for those older than 60 years) and ATRA, without or with gemtuzumab ozogamicin (3 mg/m2 administered intravenously on day 1 of induction cycles 1 and 2, and consolidation cycle 1). The primary endpoints were short-term event-free survival and overall survival in the intention-to-treat population (overall survival was added as a co-primary endpoint after amendment four of the protocol on Oct 13, 2013). The secondary endpoints were event-free survival with long-term follow-up, rates of complete remission, complete remission with partial haematological recovery (CRh), and complete remission with incomplete haematological recovery (CRi), cumulative incidences of relapse and death, and number of days in hospital. This trial is registered with ClinicalTrials.gov (NCT00893399) and has been completed.

FINDINGS

Between May 12, 2010, and Sept 1, 2017, 600 participants were enrolled, of which 588 (315 women and 273 men) were randomly assigned (296 to the standard group and 292 to the gemtuzumab ozogamicin group). No difference was found in short-term event-free survival (short-term event-free survival at 6-month follow-up, 53% [95% CI 47-59] in the standard group and 58% [53-64] in the gemtuzumab ozogamicin group; hazard ratio [HR] 0·83; 95% CI 0·65-1·04; p=0·10) and overall survival between treatment groups (2-year overall survival, 69% [63-74] in the standard group and 73% [68-78] in the gemtuzumab ozogamicin group; 0·90; 0·70-1·16; p=0·43). There was no difference in complete remission or CRi rates (n=267 [90%] in the standard group vs n=251 [86%] in the gemtuzumab ozogamicin group; odds ratio [OR] 0·67; 95% CI 0·40-1·11; p=0·15) and complete remission or CRh rates (n=214 [72%] vs n=195 [67%]; OR 0·77; 0·54-1·10; p=0·18), whereas the complete remission rate was lower with gemtuzumab ozogamicin (n=172 [58%] vs n=136 [47%]; OR 0·63; 0·45-0·80; p=0·0068). Cumulative incidence of relapse was significantly reduced by gemtuzumab ozogamicin (2-year cumulative incidence of relapse, 37% [95% CI 31-43] in the standard group and 25% [20-30] in the gemtuzumab ozogamicin group; cause-specific HR 0·65; 0·49-0·86; p=0·0028), and there was no difference in the cumulative incidence of death (2-year cumulative incidence of death 6% [4-10] in the standard group and 7% [5-11] in the gemtuzumab ozogamicin group; HR 1·03; 0·59-1·81; p=0·91). There were no differences in the number of days in hospital across all cycles between treatment groups. The most common treatment-related grade 3-4 adverse events were febrile neutropenia (n=135 [47%] in the gemtuzumab ozogamicin group vs n=122 [41%] in the standard group), thrombocytopenia (n=261 [90%] vs n=265 [90%]), pneumonia (n=71 [25%] vs n=64 [22%]), sepsis (n=85 [29%] vs n=73 [25%]). Treatment-related deaths were documented in 25 participants (4%; n=8 [3%] in the standard group and n=17 [6%] in the gemtuzumab ozogamicin group), mostly due to sepsis and infections.

INTERPRETATION

The primary endpoints of the trial of event-free survival and overall survival were not met. However, an anti-leukaemic efficacy of gemtuzumab ozogamicin in participants with NPM1-mutated acute myeloid leukaemia is shown by a significantly lower cumulative incidence of relapse rate, suggesting that the addition of gemtuzumab ozogamicin might reduce the need for salvage therapy in these participants. The results from this study provide further evidence that gemtuzumab ozogamicin should be added in the standard of care treatment in adults with NPM1-mutated acute myeloid leukaemia.

FUNDING

Pfizer and Amgen.

Super-enhancer-associated gene CAPG promotes AML progression

Acute myeloid leukemia is the most common acute leukemia in adults, the barrier of refractory and drug resistance has yet to be conquered in the clinical. Abnormal gene expression and epigenetic changes play an important role in pathogenesis and treatment. A super-enhancer is an epigenetic modifier that promotes pro-tumor genes and drug resistance by activating oncogene transcription. Multi-omics integrative analysis identifies the super-enhancer-associated gene CAPG and its high expression level was correlated with poor prognosis in AML. CAPG is a cytoskeleton protein but has an unclear function in AML. Here we show the molecular function of CAPG in regulating NF-κB signaling pathway by proteomic and epigenomic analysis. Knockdown of Capg in the AML murine model resulted in exhausted AML cells and prolonged survival of AML mice. In conclusion, SEs-associated gene CAPG can contributes to AML progression through NF-κB.

A Question of Frame: The Role of the Bone Marrow Stromal Niche in Myeloid Malignancies

Until a few years ago, the onset of acute myeloid leukemia (AML) was entirely ascribed to genetic lesions in hematopoietic stem cells. These mutations generate leukemic stem cells, which are known to be the main ones responsible for chemoresistance and relapse. However, in the last years, increasing evidence demonstrated that dynamic interplay between leukemic cells and bone marrow (BM) niche is of paramount relevance in the pathogenesis of myeloid malignancies, including AML. Specifically, BM stromal niche components, such as mesenchymal stromal cells (MSCs) and their osteoblastic cell derivatives, play a key role not only in supporting normal hematopoiesis but also in the manifestation and progression of myeloid malignancies. Here, we reviewed recent clinical and experimental findings about how genetic and functional alterations in MSCs and osteolineage progeny can contribute to leukemogenesis and how leukemic cells in turn generate a corrupted niche able to support myeloid neoplasms. Moreover, we discussed how the newest single-cell technologies may help dissect the interactions between BM stromal cells and malignant hematopoiesis. The deep comprehension of the tangled relationship between stroma and AML blasts and their modulation during disease progression may have a valuable impact on the development of new microenvironment-directed therapeutic strategies, potentially useful for a wide cohort of patients.

Combination Therapies with Kinase Inhibitors for Acute Myeloid Leukemia Treatment

Targeting kinase activity is considered to be an attractive therapeutic strategy to overcome acute myeloid leukemia (AML) since aberrant activation of the kinase pathway plays a pivotal role in leukemogenesis through abnormal cell proliferation and differentiation block. Although clinical trials for kinase modulators as single agents remain scarce, combination therapies are an area of therapeutic interest. In this review, the author summarizes attractive kinase pathways for therapeutic targets and the combination strategies for these pathways. Specifically, the review focuses on combination therapies targeting the FLT3 pathways, as well as PI3K/AKT/mTOR, CDK and CHK1 pathways. From a literature review, combination therapies with the kinase inhibitors appear more promising than monotherapies with individual agents. Therefore, the development of efficient combination therapies with kinase inhibitors may result in effective therapeutic strategies for AML.

TLR8 agonist Motolimod-induced inflammatory death for treatment of acute myeloid leukemia

The clinical treatment of AML is dominated by "7 + 3" therapy, but it often shows great toxicity and limited therapeutic efficacy in application. Therefore, it is urgent to develop novel therapeutic strategies to achieve safe and efficient treatment of AML. Small-molecule inhibitors have the characteristics of high specificity, low off-target toxicity and remarkable therapeutic effect, and are receiving more and more attention in tumor therapy. In this study, we screened a library of 1972 FDA-approved small molecular compounds for those that induced the inflammatory death of AML cells, among which the TLR8 agonist Motolimod (MTL) showed stronger anti-AML activity in the animal model but slight affection on normal lymphocytes in control mice. In terms of mechanism, cellular experiments in AML cell lines proved that TLR8 and LKB1/AMPK are the key distinct mechanisms for MTL triggered caspase-3-dependent cell death and the expression of a large number of inflammatory factors. In conclusion, our findings identified the immunoactivator MTL as a single agent exerting significant anti-AML activity in vitro and in vivo, with strong potential for clinical translation.

Dual IKZF2 and CK1α degrader targets acute myeloid leukemia cells

Acute myeloid leukemia (AML) is a hematologic malignancy for which several epigenetic regulators have been identified as therapeutic targets. Here we report the development of cereblon-dependent degraders of IKZF2 and casein kinase 1α (CK1α), termed DEG-35 and DEG-77. We utilized a structure-guided approach to develop DEG-35 as a nanomolar degrader of IKZF2, a hematopoietic-specific transcription factor that contributes to myeloid leukemogenesis. DEG-35 possesses additional substrate specificity for the therapeutically relevant target CK1α, which was identified through unbiased proteomics and a PRISM screen assay. Degradation of IKZF2 and CK1α blocks cell growth and induces myeloid differentiation in AML cells through CK1α-p53- and IKZF2-dependent pathways. Target degradation by DEG-35 or a more soluble analog, DEG-77, delays leukemia progression in murine and human AML mouse models. Overall, we provide a strategy for multitargeted degradation of IKZF2 and CK1α to enhance efficacy against AML that may be expanded to additional targets and indications.

Set Protein Is Involved in FLT3 Membrane Trafficking

The in-frame internal tandem duplication (ITD) of the FLT3 gene is an important negative prognostic factor in acute myeloid leukemia (AML). FLT3-ITD is constitutive active and partially retained in the endoplasmic reticulum (ER). Recent reports show that 3'UTRs function as scaffolds that can regulate the localization of plasma membrane proteins by recruiting the HuR-interacting protein SET to the site of translation. Therefore, we hypothesized that SET could mediate the FLT3 membrane location and that the FLT3-ITD mutation could somehow disrupt the model, impairing its membrane translocation. Immunofluorescence and immunoprecipitation assays demonstrated that SET and FLT3 co-localize and interact in FLT3-WT cells but hardly in FLT3-ITD. SET/FLT3 interaction occurs before FLT3 glycosylation. Furthermore, RNA immunoprecipitation in FLT3-WT cells confirmed that this interaction occurs through the binding of HuR to the 3'UTR of FLT3. HuR inhibition and SET nuclear retention reduced FLT3 in the membrane of FLT3-WT cells, indicating that both proteins are involved in FLT3 membrane trafficking. Interestingly, the FLT3 inhibitor midostaurin increases FLT3 in the membrane and SET/FLT3 binding. Therefore, our results show that SET is involved in the transport of FLT3-WT to the membrane; however, SET barely binds FLT3 in FLT3-ITD cells, contributing to its retention in the ER.

Amsacrine-based induction therapy in AML patients with cardiac comorbidities: a retrospective single-center analysis

Intensive chemotherapy is the backbone of induction treatment in patients with acute myeloid leukemia (AML). However, AML patients with concomitant cardiac disease may not be eligible for anthracycline-based therapies. In a small cohort of patients, we have previously shown that anthracycline-free, amsacrine-based chemotherapy TAA (thioguanine, cytarabine, amsacrine) may be as effective as cytarabine/daunorubicin for induction therapy in these patients. In this systematic retrospective single-center analysis, we documented the outcome of 31 patients with significant cardiac comorbidities including coronary heart disease or cardiomyopathy receiving TAA as induction chemotherapy. Median (range) ejection fraction (EF) was 48% (30-67%) in this cohort. Patients with EF below 30% were considered unfit for intensive induction therapy. Event-free survival (EFS), overall survival (OS), and relapse-free survival (RFS) were 1.61, 5.46, and 13.6 months respectively. Poor outcome was primarily related to a high early mortality rate within the first 30 days of therapy, mainly caused by infectious complications. TAA cannot be recommended as a substitute of standard induction for AML patients with significant concomitant cardiac disease. In the era of novel agents, alternative strategies (e.g., hypomethylating agents plus venetoclax) should be considered when anthracycline-based regimens are not suitable.

Targeting a mitochondrial E3 ubiquitin ligase complex to overcome AML cell-intrinsic Venetoclax resistance

To identify molecules/pathways governing Venetoclax (VEN) sensitivity, we performed genome-wide CRISPR/Cas9 screens using a mouse AML line insensitive to VEN-induced mitochondrial apoptosis. Levels of sgRNAs targeting March5, Ube2j2 or Ube2k significantly decreased upon VEN treatment, suggesting synthetic lethal interaction. Depletion of either Ube2j2 or Ube2k sensitized AML cells to VEN only in the presence of March5, suggesting coordinate function of the E2s Ube2j2 and Ube2k with the E3 ligase March5. We next performed CRISPR screens using March5 knockout cells and identified Noxa as a key March5 substrate. Mechanistically, Bax released from Bcl2 upon VEN treatment was entrapped by Mcl1 and Bcl-XL and failed to induce apoptosis in March5 intact AML cells. By contrast, in March5 knockout cells, liberated Bax did not bind to Mcl1, as Noxa likely occupied Mcl1 BH3-binding grooves and efficiently induced mitochondrial apoptosis. We reveal molecular mechanisms underlying AML cell-intrinsic VEN resistance and suggest a novel means to sensitize AML cells to VEN.

Recent advances in targeted therapies in acute myeloid leukemia

Acute myeloid leukemia (AML) is the most common acute leukemia in adults. While survival for younger patients over the last several decades has improved nearly sixfold with the optimization of intensive induction chemotherapy and allogeneic stem cell transplantation (alloHSCT), this effect has been largely mitigated in older and less fit patients as well as those with adverse-risk disease characteristics. However, the last 10 years has been marked by major advances in the molecular profiling of AML characterized by a deeper understanding of disease pathobiology and therapeutic vulnerabilities. In this regard, the classification of AML subtypes has recently evolved from a morphologic to a molecular and genetic basis, reflected by recent updates from the World Health Organization and the new International Consensus Classification system. After years of stagnation in new drug approvals for AML, there has been a rapid expansion of the armamentarium against this disease since 2017. Low-intensity induction therapy with hypomethylating agents and venetoclax has substantially improved outcomes, including in those previously considered to have a poor prognosis. Furthermore, targeted oral therapies against driver mutations in AML have been added to the repertoire. But with an accelerated increase in treatment options, several questions arise such as how to best sequence therapy, how to combine therapies, and if there is a role for maintenance therapy in those who achieve remission and cannot undergo alloHSCT. Moreover, certain subtypes of AML, such as those with TP53 mutations, still have dismal outcomes despite these recent advances, underscoring an ongoing unmet need and opportunity for translational advances. In this review, we will discuss recent updates in the classification and risk stratification of AML, explore the literature regarding low-intensity and novel oral combination therapies, and briefly highlight investigative agents currently in early clinical development for high-risk disease subtypes.

Exploring underlying mechanism of artesunate in treatment of acute myeloid leukemia using network pharmacology and molecular docking

BACKGROUND

Acute myeloid leukemia (AML) is a highly heterogeneous hematological cancer. The current diagnosis and therapy model of AML has gradually shifted to personalization and accuracy. Artesunate, a member of the artemisinin family, has anti-tumor impacts on AML. This research uses network pharmacology and molecular docking to anticipate artesunate potential mechanisms of action in the therapy of AML.

METHODS

Screening the action targets of artesunate through Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP), PubChem, and Swiss Target Prediction databases; The databases of Online Mendelian Inheritance in Man (OMIM), Disgenet, GeneCards, and Drugbank were utilized to identify target genes of AML, and an effective target of artesunate for AML treatment was obtained through cross-analysis. Protein-protein interaction (PPI) networks are built on the Cytoscape platform. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were conducted on the relevant targets using R software. Finally, using molecular docking technology and Pymol, we performed verification of the effects of active components and essential targets.

RESULTS

Artesunate 30 effective targets for treating AML include CASP3, EGFR, MAPK1, and STAT3, four targeted genes that may have a crucial function in disease management. The virus infection-related pathway (HeptatisB (HBV), Human papillomavirus (HPV), Epstein-Barr virus (EBV) infection and etc.), FoxO, viral carcinogenesis, and proteoglycans in cancer signaling pathways have all been hypothesized to be involved in the action mechanism of GO, which is enriched in 2044 biological processes, 125 molecular functions, 209 cellular components, and 106 KEGG pathways. Molecular docking findings revealed that artesunate was critically important in the therapy of AML due to its high affinity for the four primary disease targets. Molecular docking with a low binding energy yields helpful information for developing medicines against AML.

CONCLUSIONS

Consequently, artesunate may play a role in multi-targeted, multi-signaling pathways in treating AML, suggesting that artesunate may have therapeutic potential for AML.

CYP2C19 gene polymorphism in Ningxia

BACKGROUND

Poor metabolizer (PM) status of CYP2C19 can be a predisposing factor for developing gastric cancer in H. pylori-infected patients. It is unclear whether PM status of CYP2C19 can also be a potential factor for H.pylori infection in healthy people.

METHODS

We used high-throughput sequencing to detect single nucleotide polymorphisms (SNPs) at just three loci, rs4244285 (CYP2C19*2), rs4986893 (CYP2C19*3) and rs12248560 (CYP2C19*17), to identify the exact CYP2C19 alleles corresponding to the mutated sites. We determined CYP2C19 genotypes of 1050 subjects from 5 cities of Ningxia from September 2019 to September 2020 and evaluated the potential correlation between H.pylori and CYP2C19 gene polymorphisms. Clinical data were analyzed using χ2 tests.

RESULTS

The frequency of CYP2C19*17 in Hui (3.7%) was higher as compared to Han (1.4%) in Ningxia (p = 0.001). The frequency of CYP2C19*1/*17 of Hui (4.7%) was higher as compared to Han (1.6%) in Ningxia (p = 0.004). The frequency of CYP2C19*3/*17 of Hui (1%) was higher as compared to Han (0%) in Ningxia (p = 0.023). The frequencies of alleles (p = 0.142) and genotypes (p = 0.928) were not found to be significantly different among the different BMI groups. The frequencies of four alleles between H. pylori positive and negative groups were not found to be statistically different (p = 0.794). The frequencies of the different genotypes between H. pylori positive and negative groups were not statistically different (p = 0.974), and no statistical difference was observed between the different metabolic phenotypes (p = 0.494).

CONCLUSION

There were regional differences observed in CYP2C19*17 distribution in Ningxia. The frequency of CYP2C19*17 in Hui was higher than in Han of Ningxia. No significant relationship was found between CYP2C19 gene polymorphism and susceptibility to H. pylori infection.

Gene Mutations and Targeted Therapies of Myeloid Sarcoma

OPINION STATEMENT

Myeloid sarcoma, a rare malignant tumor characterized by the invasion of extramedullary tissue by immature myeloid cells, commonly occurs concomitantly with acute myeloid leukemia, myelodysplastic syndromes, or myeloproliferative neoplasms. The rarity of myeloid sarcoma poses challenges for diagnosis and treatment. Currently, treatments for myeloid sarcoma remain controversial and primarily follow protocols for acute myeloid leukemia, such as chemotherapy utilizing multi-agent regimens, in addition to radiation therapy and/or surgery. The advancements in next-generation sequencing technology have led to significant progress in the field of molecular genetics, resulting in the identification of both diagnostic and therapeutic targets. The application of targeted therapeutics, such as FMS-like tyrosine kinase 3(FLT3) inhibitors, isocitrate dehydrogenases(IDH) inhibitors, and the B cell lymphoma 2(BCL2) inhibitors, has facilitated the gradual transformation of traditional chemotherapy into targeted precision therapy for acute myeloid leukemia. However, the field of targeted therapy for myeloid sarcoma is relatively under-investigated and not well-described. In this review, we comprehensively summarize the molecular genetic characteristics of myeloid sarcoma and the current application of targeted therapeutics.

Activation of the PP2A-B56α heterocomplex synergizes with venetoclax therapies in AML through BCL2 and MCL1 modulation

Venetoclax combination therapies are becoming the standard of care in acute myeloid leukemia (AML). However, the therapeutic benefit of these drugs in older/unfit patients is limited to only a few months, highlighting the need for more effective therapies. Protein phosphatase 2A (PP2A) is a tumor suppressor phosphatase with pleiotropic functions that becomes inactivated in ∼70% of AML cases. PP2A promotes cancer cell death by modulating the phosphorylation state in a variety of proteins along the mitochondrial apoptotic pathway. We therefore hypothesized that pharmacological PP2A reactivation could increase BCL2 dependency in AML cells and, thus, potentiate venetoclax-induced cell death. Here, by using 3 structurally distinct PP2A-activating drugs, we show that PP2A reactivation synergistically enhances venetoclax activity in AML cell lines, primary cells, and xenograft models. Through the use of gene editing tools and pharmacological approaches, we demonstrate that the observed therapeutic synergy relies on PP2A complexes containing the B56α regulatory subunit, of which expression dictates response to the combination therapy. Mechanistically, PP2A reactivation enhances venetoclax-driven apoptosis through simultaneous inhibition of antiapoptotic BCL2 and extracellular signal-regulated kinase signaling, with the latter decreasing MCL1 protein stability. Finally, PP2A targeting increases the efficacy of the clinically approved venetoclax and azacitidine combination in vitro, in primary cells, and in an AML patient-derived xenograft model. These preclinical results provide a scientific rationale for testing PP2A-activating drugs with venetoclax combinations in AML.

Identification of tumor antigens and immune subtypes of acute myeloid leukemia for mRNA vaccine development

BACKGROUND

Acute myeloid leukemia (AML) is a highly aggressive hematological malignancy, and there has not been any significant improvement in therapy of AML over the past several decades. The mRNA vaccines have become a promising strategy against multiple cancers, however, its application on AML remains undefined. In this study, we aimed to identify novel antigens for developing mRNA vaccines against AML and explore the immune landscape of AML to select appropriate patients for vaccination.

METHODS

Genomic data and gene mutation data were retrieved from TCGA, GEO and cBioPortal, respectively. GEPIA2 was used to analyze differentially expressed genes. The single cell RNA-seq database Tumor Immune Single-cell Hub (TISCH) was used to explore the association between the potential tumor antigens and the infiltrating immune cells in the bone marrow. Consensus clustering analysis was applied to identify distinct immune subtypes. The correlation between the abundance of antigen presenting cells and the expression level of antigens was evaluated using Spearman correlation analysis. The characteristics of the tumor immune microenvironment in each subtype were investigated based on single-sample gene set enrichment analysis.

RESULTS

Five potential tumor antigens were identified for mRNA vaccine from the pool of overexpressed and mutated genes, including CDH23, LRP1, MEFV, MYOF and SLC9A9, which were associated with infiltration of antigen-presenting immune cells (APCs). AML patients were stratified into two immune subtypes Cluster1 (C1) and Cluster2 (C2), which were characterized by distinct molecular and clinical features. C1 subtype demonstrated an immune-hot and immunosuppressive phenotype, while the C1 subtype had an immune-cold phenotype. Furthermore, the two immune subtype showed remarkably different expression of immune checkpoints, immunogenic cell death modulators and human leukocyte antigens.

CONCLUSION

CDH23, LRP1, MEFV, MYOF and SLC9A9 were potential antigens for developing AML mRNA vaccine, and AML patients in immune subtype 1 were suitable for vaccination.

Acquired mutations in BAX confer resistance to BH3-mimetic therapy in acute myeloid leukemia

Randomized trials in acute myeloid leukemia (AML) have demonstrated improved survival by the BCL-2 inhibitor venetoclax combined with azacitidine in older patients, and clinical trials are actively exploring the role of venetoclax in combination with intensive chemotherapy in fitter patients with AML. As most patients still develop recurrent disease, improved understanding of relapse mechanisms is needed. We find that 17% of patients relapsing after venetoclax-based therapy for AML have acquired inactivating missense or frameshift/nonsense mutations in the apoptosis effector gene BAX. In contrast, such variants were rare after genotoxic chemotherapy. BAX variants arose within either leukemic or preleukemic compartments, with multiple mutations observed in some patients. In vitro, AML cells with mutated BAX were competitively selected during prolonged exposure to BCL-2 antagonists. In model systems, AML cells rendered deficient for BAX, but not its close relative BAK, displayed resistance to BCL-2 targeting, whereas sensitivity to conventional chemotherapy was variable. Acquired mutations in BAX during venetoclax-based therapy represent a novel mechanism of resistance to BH3-mimetics and a potential barrier to the long-term efficacy of drugs targeting BCL-2 in AML.

Targeting Mitochondrial IDH2 Enhances Antitumor Activity of Cisplatin in Lung Cancer via ROS-Mediated Mechanism

Mitochondrial isocitrate dehydrogenase 2 (IDH2) is an important metabolic enzyme in the tricarboxylic acid cycle (TCA) cycle. Our previous study showed that high expression of wild-type IDH2 promotes the proliferation of lung cancer cells. This study aims to test the potential of targeting IDH2 as a therapeutic strategy to inhibit lung cancer in vitro and in vivo. First, we analyzed the available data from the databases gene expression omnibus (GEO) database to evaluate the clinical relevance of IDH2 expression in affecting lung cancer patient survival. We then generated a stable IDH2-knockdown lung cancer cell line using a lentivirus-based method for in vitro and in vivo study. Cell growth, apoptosis, cell viability, and colony formation assays were conducted to test the sensitivity of lung cancer cells with different IDH2 expression status to cisplatin or radiation treatment in vitro. For mechanistic study, Cellular oxygen consumption and extracellular acidification rates were measured using a Seahorse metabolic analyzer, and reactive oxygen species (ROS) generation was analyzed using flow cytometry. An animal study using a xenograft tumor model was performed to further evaluate the in vivo therapeutic effect on tumor growth. We found that high IDH2 expression was associated with poor survival in lung cancer patients undergoing chemotherapy. Inhibition of IDH2 significantly enhanced the anticancer activity of cisplatin and also increased the effect of radiation against lung cancer cells. IDH2 was upregulated in cisplatin-resistant lung cancer cells, which could be sensitized by targeted inhibition of IDH2. Mechanistic study showed that abrogation of IDH2 caused only minimal changes in oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) in lung cancer cells, but induced a significant increase in ROS, which rendered the cancer cells more sensitive to cisplatin. Pretreatment of lung cancer cells with the ROS scavenger N-acetyl-cysteine could partially rescue cells from the cytotoxic effect of cisplatin and IDH2 inhibition. Importantly, abrogation of IDH2 significantly increased the sensitivity of lung cancer cells to cisplatin in vivo.

Mitochondrial fusion is a therapeutic vulnerability of acute myeloid leukemia

Mitochondrial metabolism recently emerged as a critical dependency in acute myeloid leukemia (AML). The shape of mitochondria is tightly regulated by dynamin GTPase proteins, which drive opposing fusion and fission forces to consistently adapt bioenergetics to the cellular context. Here, we showed that targeting mitochondrial fusion was a new vulnerability of AML cells, when assayed in patient-derived xenograft (PDX) models. Genetic depletion of mitofusin 2 (MFN2) or optic atrophy 1 (OPA1) or pharmacological inhibition of OPA1 (MYLS22) blocked mitochondrial fusion and had significant anti-leukemic activity, while having limited impact on normal hematopoietic cells ex vivo and in vivo. Mechanistically, inhibition of mitochondrial fusion disrupted mitochondrial respiration and reactive oxygen species production, leading to cell cycle arrest at the G₀/G₁ transition. These results nominate the inhibition of mitochondrial fusion as a promising therapeutic approach for AML.

Therapy resistance mechanisms in hematological malignancies

Hematologic malignancies are model diseases for understanding neoplastic transformation and serve as prototypes for developing effective therapies. Indeed, the concept of systemic cancer therapy originated in hematologic malignancies and has guided the development of chemotherapy, cellular therapies, immunotherapy and modern precision oncology. Despite significant advances in the treatment of leukemias, lymphomas and multiple myelomas, treatment resistance associated with molecular and clinical relapse remains very common. Therapy of relapsed and refractory disease remains extremely difficult, and failure of disease control at this stage remains the leading cause of mortality in patients with hematologic malignancies. In recent years, many efforts have been made to identify the genetic and epigenetic mechanisms that drive the development of hematologic malignancies to the stage of full-blown disease requiring clinical intervention. In contrast, the mechanisms responsible for treatment resistance in hematologic malignancies remain poorly understood. For example, the molecular characteristics of therapy-resistant persisting cells in minimal residual disease (MRD) remain rather elusive. In this mini-review we want to discuss that cellular heterogeneity and plasticity, together with adaptive genetic and epigenetic processes, lead to reduced sensitivity to various treatment regimens such as chemotherapy and pathway inhibitors such as tyrosine kinase inhibitors. However, resistance mechanisms may be conserved across biologically distinct cancer entities. Recent technological advances have made it possible to explore the underlying mechanisms of therapy resistance with unprecedented resolution and depth. These include novel multi-omics technologies with single cell resolution combined with advanced biocomputational approaches, along with artificial intelligence (AI) and sophisticated disease models for functional validation.

Update on current treatments for adult acute myeloid leukemia: to treat acute myeloid leukemia intensively or non-intensively? That is the question

For several decades, the treatment for acute myeloid leukemia (AML) has been a dichotomous choice between intensive chemotherapy strategies with curative intent and non-intensive options including supportive care. Patients' age and fitness, as well as comorbidities, primarily influenced this choice. However, the therapeutic armamentarium is evolving, so that there are highly effective and increasingly specific drugs, fitting the mutational profile of a patient's leukemia. There is now a spectrum of treatment options that are less intense and can be administered in an outpatient setting and to a substantial extent are equally or even more effective than standard intensive therapy. We are, therefore, witnessing a radical change in the treatment landscape of AML. In this review, we examine the current treatment options for patients with AML, considering the molecular spectrum of the disease on the background of patient-related factors.

Novel insights into histone lysine methyltransferases in cancer therapy: From epigenetic regulation to selective drugs

The reversible and precise temporal and spatial regulation of histone lysine methyltransferases (KMTs) is essential for epigenome homeostasis. The dysregulation of KMTs is associated with tumor initiation, metastasis, chemoresistance, invasiveness, and the immune microenvironment. Therapeutically, their promising effects are being evaluated in diversified preclinical and clinical trials, demonstrating encouraging outcomes in multiple malignancies. In this review, we have updated recent understandings of KMTs' functions and the development of their targeted inhibitors. First, we provide an updated overview of the regulatory roles of several KMT activities in oncogenesis, tumor suppression, and immune regulation. In addition, we summarize the current targeting strategies in different cancer types and multiple ongoing clinical trials of combination therapies with KMT inhibitors. In summary, we endeavor to depict the regulation of KMT-mediated epigenetic landscape and provide potential epigenetic targets in the treatment of cancers.

FMS-Like Tyrosine Kinase 3 Inhibitors in the Treatment of Acute Myeloid Leukemia: An Update on the Emerging Evidence and Safety Profile

FMS-like tyrosine kinase 3 (FLT3) is one of the most frequently mutated genes in acute myeloid leukemia (AML). Approximately 30% of the adult cases harbor an internal tandem duplication (FLT3-ITD) and 5-10% a tyrosine kinase domain (TKD) amino acid substitution (FLT3-TKD). The treatment paradigm of AML patients harboring FLT3 mutations (30%) has been modified by the discovery of tyrosine kinase inhibitors. First- and second-generation inhibitors classify FLT3 inhibitors according to FLT3 specificity: first-generation FLT3 inhibitors include sorafenib and midostaurin and second-generation inhibitors are represented by quizartinib, gilteritinib and crenolanib, among others. Activity of these inhibitors depends on their mechanism of receptor binding (active vs inactive conformation) and efficacy against the FLT3-ITD and -TKD mutations (type 1 inhibitors are active both on FLT3-ITD and TKD, whereas type 2 inhibitors are active only on FLT3-ITD). The FLT3 inhibitors sorafenib, midostaurin, quizartinib and gilteritinib have been tested in monotherapy in several settings including refractory or relapsed AML (R/R AML), post-transplant maintenance as well as in combination with intensive chemotherapy (ICT) or non-intensity regimens. The results of published randomized studies support the use of sorafenib in a post-transplant setting (SORMAIN trial), midostaurin in combination with ICT based (RATIFY trial) and gilteritinib for R/R AML (ADMIRAL trial). Gilteritinib in combination with hypomethylating agent as well as quizartinib are not supported by solid randomized trial results for their use in FLT3-mutated AML patients.

CircZBTB46 Protects Acute Myeloid Leukemia Cells from Ferroptotic Cell Death by Upregulating SCD

Circular RNAs (circRNAs) have been shown to be closely linked to the tumorigenesis and treatment response of hematological malignancies. However, the biological functions and clinical implications of circRNAs in acute myeloid leukemia (AML) remain largely unknown. CircRNA microarray datasets were analyzed to screen differentially expressed circRNAs in AML patients. It was found that circZBTB46 was significantly upregulated in AML patients and AML cells. Moreover, the expression of circZBTB46 was associated with the stages of AML patients and showed high sensitivity and specificity for diagnosing AML. Silencing of circZBTB46 inhibited AML cell proliferation and induced cell cycle arrest. Importantly, the depletion of circZBTB46 notably increased ferroptosis and enhanced RSL3-induced ferroptosis in AML cells. Mechanistically, circZBTB46 upregulated the expression of stearoyl-CoA desaturase 1 (SCD) possibly by acting as a miRNA sponge. Finally, the circZBTB46 knockdown repressed the tumor growth of AML in vivo. In conclusion, circZBTB46 protects AML cells from ferroptosis and promotes the proliferation by upregulating SCD, thus suggesting that circZBTB46 may be a potential therapeutic target for AML.

A hybrid algorithm for clinical decision support in precision medicine based on machine learning

PURPOSE

The objective of the manuscript is to propose a hybrid algorithm combining the improved BM25 algorithm, k-means clustering, and BioBert model to better determine biomedical articles utilizing the PubMed database so, the number of retrieved biomedical articles whose content contains much similar information regarding a query of a specific disease could grow larger.

DESIGN/METHODOLOGY/APPROACH

In the paper, a two-stage information retrieval method is proposed to conduct an improved Text-Rank algorithm. The first stage consists of employing the improved BM25 algorithm to assign scores to biomedical articles in the database and identify the 1000 publications with the highest scores. The second stage is composed of employing a method called a cluster-based abstract extraction to reduce the number of article abstracts to match the input constraints of the BioBert model, and then the BioBert-based document similarity matching method is utilized to obtain the most similar search outcomes between the document and the retrieved morphemes. To realize reproducibility, the written code is made available on https://github.com/zzc1991/TREC_Precision_Medicine_Track .

FINDINGS

The experimental study is conducted based on the data sets of TREC2017 and TREC2018 to train the proposed model and the data of TREC2019 is used as a validation set confirming the effectiveness and practicability of the proposed algorithm that would be implemented for clinical decision support in precision medicine with a generalizability feature.

ORIGINALITY/VALUE

This research integrates multiple machine learning and text processing methods to devise a hybrid method applicable to domains of specific medical literature retrieval. The proposed algorithm provides a 3% increase of P@10 than that of the state-of-the-art algorithm in TREC 2019.

Blasts in context: the impact of the immune environment on acute myeloid leukemia prognosis and treatment

Acute myeloid leukemia (AML) is a cancer that originates from the bone marrow (BM). Under physiological conditions, the bone marrow supports the homeostasis of immune cells and hosts memory lymphoid cells. In this review, we summarize our present understanding of the role of the immune microenvironment on healthy bone marrow and on the development of AML, with a focus on T cells and other lymphoid cells. The types and function of different immune cells involved in the AML microenvironment as well as their putative role in the onset of disease and response to treatment are presented. We also describe how the immune context predicts the response to immunotherapy in AML and how these therapies modulate the immune status of the bone marrow. Finally, we focus on allogeneic stem cell transplantation and summarize the current understanding of the immune environment in the post-transplant bone marrow, the factors associated with immune escape and relevant strategies to prevent and treat relapse.

Precision Medicine in Therapy of Non-solid Cancer

The development and approval of the tyrosine kinase inhibitor imatinib in 2001 has heralded the advance of directed therapy options. Today, an armamentarium of targeted therapeutics is available and enables the use of precision medicine in non-solid cancer. Precision medicine is guided by the detection of tumor-specific and targetable characteristics. These include pathogenic fusions and/or mutations, dependency on specific signaling pathways, and the expression of certain cell surface markers. Within the first part, we review approved targeted therapies for the compound classes of small molecule inhibitors, antibody-based therapies and cellular therapies. Particular consideration is given to the underlying pathobiology and the respective mechanism of action. The second part emphasizes on how biomarkers, whether they are of diagnostic, prognostic, or predictive relevance, are indispensable tools to guide therapy choice and management in precision medicine. Finally, the examples of acute myeloid leukemia, chronic lymphocytic leukemia, and chronic myeloid leukemia illustrate how integration of these biomarkers helps to tailor therapy.

Antibiotic discovery in the artificial intelligence era

As the global burden of antibiotic resistance continues to grow, creative approaches to antibiotic discovery are needed to accelerate the development of novel medicines. A rapidly progressing computational revolution-artificial intelligence-offers an optimistic path forward due to its ability to alleviate bottlenecks in the antibiotic discovery pipeline. In this review, we discuss how advancements in artificial intelligence are reinvigorating the adoption of past antibiotic discovery models-namely natural product exploration and small molecule screening. We then explore the application of contemporary machine learning approaches to emerging areas of antibiotic discovery, including antibacterial systems biology, drug combination development, antimicrobial peptide discovery, and mechanism of action prediction. Lastly, we propose a call to action for open access of high-quality screening datasets and interdisciplinary collaboration to accelerate the rate at which machine learning models can be trained and new antibiotic drugs can be developed.

Time for Dynamic Assessment of Fitness in Acute Myeloid Leukemia

Informed treatment decision-making in acute myeloid leukemia (AML) requires a comprehensive evaluation of all clinical and biological features that may affect the outcome with any given type or intensity of therapy [...].

Modeling leukemia with zebrafish (Danio rerio): Towards precision medicine

Leukemia is a type of blood cancer characterized by high genetic heterogeneity and fatality. While chemotherapy remains the primary form of treatment for leukemia, its effectiveness was profoundly diminished by the genetic heterogeneity and cytogenetic abnormalities of leukemic cells. Therefore, there is an unmet need to develop precision medicine for leukemia with distinct genetic backgrounds. Zebrafish (Danio rerio), a freshwater fish with exceptional feasibility in genome editing, is a powerful tool for rapid human cancer modeling. In the past decades, zebrafish have been adopted in modeling human leukemia, exploring the molecular mechanisms of underlying genetic abnormalities, and discovering novel therapeutic agents. Although many recurrent mutations of leukemia have been modeled in zebrafish for pathological study and drug discovery, its great potential in leukemia modeling was not yet fully exploited, particularly in precision medicine. In this review, we evaluated the current zebrafish models of leukemia/pre-leukemia and genetic techniques and discussed the potential of zebrafish models with novel techniques, which may contribute to the development of zebrafish as a disease model for precision medicine in treating leukemia.

Precision Medicine in Myeloid Malignancies: Hype or Hope?

PURPOSE OF REVIEW

We review how understanding the fitness and comorbidity burden of patients, and molecular landscape of underlying acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) at the time of diagnosis is now integral to treatment.

RECENT FINDINGS

The upfront identification of patients' fitness and molecular profile facilitates selection of targeted and novel agents, enables risk stratification, allows consideration of allogeneic hematopoietic cell transplantation in high-risk patients, and provides treatment selection for older (age ≥ 75) or otherwise unfit patients who may not tolerate conventional treatment. The use of measurable residual disease (MRD) assessment improves outcome prediction and can also guide therapeutic strategies such as chemotherapy maintenance and transplant. In recent years, several novel drugs have received FDA approval for treating patients with AML with or without specific mutations. A doublet and triplet combination of molecular targeted and other novel treatments have resulted in high response rates in early trials. Following the initial success in AML, novel drugs are undergoing clinical trials in MDS. Unprecedented advances have been made in precision medicine approaches in AML and MDS. However, lack of durable responses and long-term disease control in many patients still present significant challenges, which can only be met, to some extent, with innovative combination strategies throughout the course of treatment from induction to consolidation and maintenance.

The present and future of measurable residual disease testing in acute myeloid leukemia

Considerable progress has been made in the past several years in the scientific understanding of, and available treatments for, acute myeloid leukemia (AML). Achievement of a conventional remission, evaluated cytomorphologically via small bone marrow samples, is a necessary but not sufficient step toward cure. It is increasingly appreciated that molecular or immunophenotypic methods to identify and quantify measurable residual disease (MRD) - populations of leukemia cells below the cytomorphological detection limit - provide refined information on the quality of response to treatment and prediction of the risk of AML recurrence and leukemia-related deaths. The principles and practices surrounding MRD remain incompletely determined however and the genetic and immunophenotypic heterogeneity of AML may prevent a one-sizefits- all approach. Here, we review the current approaches to MRD testing in AML, discuss strengths and limitations, highlight recent technological advances that may improve such testing, and summarize ongoing initiatives to generate the clinical evidence needed to advance the use of MRD testing in patients with AML.

FGF13 suppresses acute myeloid leukemia by regulating bone marrow niches

Fibroblast growth factor 13 (FGF13) is aberrantly expressed in multiple cancer types, suggesting its essential role in tumorigenesis. Hence, we aimed to explore its definite role in the development of acute myeloid leukemia (AML) and emphasize its associations with bone marrow niches. Results showed that FGF13 was lowly expressed in patients with AML and that its elevated expression was related to prolonged overall survival (OS). Univariate and multivariate Cox regression analyses identified FGF13 as an independent prognostic factor. A prognostic nomogram integrating FGF13 and clinicopathologic variables was constructed to predict 1-, 3-, and 5-year OS. Gene mutation and functional analyses indicated that FGF13 was not associated with AML driver mutations but was related to bone marrow niches. As for immunity, FGF13 was remarkably associated with T cell count, immune checkpoint genes, and cytokines. In addition, FGF13 overexpression substantially inhibited the growth and significantly induced the early apoptosis of AML cells. The xenograft study indicated that FGF13 overexpression prolonged the survival of recipient mice. Overall, FGF13 could serve as an independent prognostic factor for AML, and it was closely related to the bone marrow microenvironment.

HDAC1/3-dependent moderate liquid-liquid phase separation of YY1 promotes METTL3 expression and AML cell proliferation

Methyltransferase-like protein 3 (METTL3) plays critical roles in acute myeloid leukemia (AML) progression, however, the mechanism of abnormal overexpression of METTL3 in AML remain elusive. In the current study, we uncovered that Yin Yang 1 (YY1) binds to the promoter region of METTL3 as a transcription factor and promotes its expression, which in turn enhances the proliferation of AML cells. Mechanistically, YY1 binds to HDAC1/3 and regulates METTL3 expression in a moderate liquid-liquid phase separation (LLPS) manner. After mutation of the HDAC-binding site of YY1 or HDAC inhibitor (HDACi) treatment, YY1 was separated from HDAC1/3, which resulted in an excessive LLPS state, thereby inhibiting the expression of METTL3 and the proliferation of AML cells. In conclusion, our study clarified the regulatory mechanism of the abnormal expression of METTL3 in AML, revealed the precise "Yin-Yang" regulatory mechanism of YY1 from the perspective of LLPS degree, and provided new ideas for the precise diagnosis and treatment of AML.

Pharmacogenomic Profiling of Pediatric Acute Myeloid Leukemia to Identify Therapeutic Vulnerabilities and Inform Functional Precision Medicine

Despite the expanding portfolio of targeted therapies for adults with acute myeloid leukemia (AML), direct implementation in children is challenging due to inherent differences in underlying genetics. Here we established the pharmacologic profile of pediatric AML by screening myeloblast sensitivity to approved and investigational agents, revealing candidates of immediate clinical relevance. Drug responses ex vivo correlated with patient characteristics, exhibited age-specific alterations, and concorded with activities in xenograft models. Integration with genomic data uncovered new gene-drug associations, suggesting actionable therapeutic vulnerabilities. Transcriptome profiling further identified gene-expression signatures associated with on- and off-target drug responses. We also demonstrated the feasibility of drug screening-guided treatment for children with high-risk AML, with two evaluable cases achieving remission. Collectively, this study offers a high-dimensional gene-drug clinical data set that could be leveraged to research the unique biology of pediatric AML and sets the stage for realizing functional precision medicine for the clinical management of the disease.

SIGNIFICANCE

We conducted integrated drug and genomic profiling of patient biopsies to build the functional genomic landscape of pediatric AML. Age-specific differences in drug response and new gene-drug interactions were identified. The feasibility of functional precision medicine-guided management of children with high-risk AML was successfully demonstrated in two evaluable clinical cases. This article is highlighted in the In This Issue feature, p. 476.

Immune dysfunction signatures predict outcomes and define checkpoint blockade-unresponsive microenvironments in acute myeloid leukemia

BackgroundImmune exhaustion and senescence are dominant dysfunctional states of effector T cells and major hurdles for the success of cancer immunotherapy. In the current study, we characterized how acute myeloid leukemia (AML) promotes the generation of senescent-like CD8+ T cells and whether they have prognostic relevance.METHODSWe analyzed NanoString, bulk RNA-Seq and single-cell RNA-Seq data from independent clinical cohorts comprising 1,896 patients treated with chemotherapy and/or immune checkpoint blockade (ICB).ResultsWe show that senescent-like bone marrow CD8+ T cells were impaired in killing autologous AML blasts and that their proportion negatively correlated with overall survival (OS). We defined what we believe to be new immune effector dysfunction (IED) signatures using 2 gene expression profiling platforms and reported that IED scores correlated with adverse-risk molecular lesions, stemness, and poor outcomes; these scores were a more powerful predictor of OS than 2017-ELN risk or leukemia stem cell (LSC17) scores. IED expression signatures also identified an ICB-unresponsive tumor microenvironment and predicted significantly shorter OS.ConclusionThe IED scores provided improved AML-risk stratification and could facilitate the delivery of personalized immunotherapies to patients who are most likely to benefit.TRIAL REGISTRATIONClinicalTrials.gov; NCT02845297.FUNDINGJohn and Lucille van Geest Foundation, Nottingham Trent University's Health & Wellbeing Strategic Research Theme, NIH/NCI P01CA225618, Genentech-imCORE ML40354, Qatar National Research Fund (NPRP8-2297-3-494).

Molecular Targeting of the Most Functionally Complex Gene in Precision Oncology: p53

While chemotherapy is a key treatment strategy for many solid tumors, it is rarely curative, and most tumor cells eventually become resistant. Because of this, there is an unmet need to develop systemic treatments that capitalize on the unique mutational landscape of each patient's tumor. The most frequently mutated protein in cancer, p53, has a role in nearly all cancer subtypes and tumorigenesis stages and therefore is one of the most promising molecular targets for cancer treatment. Unfortunately, drugs targeting p53 have seen little clinical success despite promising preclinical data. Most of these drug compounds target specific aspects of p53 inactivation, such as through inhibiting negative regulation by the mouse double minute (MDM) family of proteins. These treatment strategies fail to address cancer cells' adaptation mechanisms and ignore the impact that p53 loss has on the entire p53 network. However, recent gene therapy successes show that targeting the p53 network and cellular dysfunction caused by p53 inactivation is now possible and may soon translate into successful clinical responses. In this review, we discuss p53 signaling complexities in cancer that have hindered the development and use of p53-targeted drugs. We also describe several current therapeutics reporting promising preclinical and clinical results.

Small molecule inhibitors targeting the cancers

Compared with traditional therapies, targeted therapy has merits in selectivity, efficacy, and tolerability. Small molecule inhibitors are one of the primary targeted therapies for cancer. Due to their advantages in a wide range of targets, convenient medication, and the ability to penetrate into the central nervous system, many efforts have been devoted to developing more small molecule inhibitors. To date, 88 small molecule inhibitors have been approved by the United States Food and Drug Administration to treat cancers. Despite remarkable progress, small molecule inhibitors in cancer treatment still face many obstacles, such as low response rate, short duration of response, toxicity, biomarkers, and resistance. To better promote the development of small molecule inhibitors targeting cancers, we comprehensively reviewed small molecule inhibitors involved in all the approved agents and pivotal drug candidates in clinical trials arranged by the signaling pathways and the classification of small molecule inhibitors. We discussed lessons learned from the development of these agents, the proper strategies to overcome resistance arising from different mechanisms, and combination therapies concerned with small molecule inhibitors. Through our review, we hoped to provide insights and perspectives for the research and development of small molecule inhibitors in cancer treatment.

Diagnosis and management of AML in adults: 2022 recommendations from an international expert panel on behalf of the ELN

The 2010 and 2017 editions of the European LeukemiaNet (ELN) recommendations for diagnosis and management of acute myeloid leukemia (AML) in adults are widely recognized among physicians and investigators. There have been major advances in our understanding of AML, including new knowledge about the molecular pathogenesis of AML, leading to an update of the disease classification, technological progress in genomic diagnostics and assessment of measurable residual disease, and the successful development of new therapeutic agents, such as FLT3, IDH1, IDH2, and BCL2 inhibitors. These advances have prompted this update that includes a revised ELN genetic risk classification, revised response criteria, and treatment recommendations.

Contemporary evaluation of acute myeloid leukemia patients with long-term survival exceeding five years

OBJECTIVES

Define clinical and laboratory attributes of acute myeloid leukemia (AML) patients with long-term survival exceeding five years and compare them with AML patients succumbing to disease within two years of diagnosis.

METHODS

A retrospective analysis of AML patients alive at least five years from the time of initial diagnosis. Baseline clinical data were compared with patients who died within two years of diagnosis.

RESULTS

The long-term cohort consisted of 93 patients treated in 2007-2016 with a median follow-up duration of 7.7 years (range 5-13.6 years). European LeukemiaNet (ELN) 2017 favorable risk patients accounted for 60% of the cohort. All long-term survivors achieved remission following induction chemotherapy. Multivariate analysis showed that compared with 132 patients experiencing death within 2 years of diagnosis, long term survivors were more likely to be of younger age [odds ratio (OR), 0.92; 95% confidence interval (CI), 0.9-0.95; p<0.001], have a lower initial WBC count (OR, 0.58; 95% CI, 0.43-0.79; p=0.0004), undergo an allogeneic stem cell transplantation (OR, 7.95; 95% CI, 3.07-20.59; p<0.0001), and harbor favorable risk cytogenetics (OR, 0.03; 95% CI, 0.006-0.23; p=0.0004).

CONCLUSIONS

Long term survival of AML is seen in a distinct demographic and biologic patient subset.

A novel fatty acid metabolism-related signature identifies features of the tumor microenvironment and predicts clinical outcome in acute myeloid leukemia

Background

Acute myeloid leukemia (AML) is the most common malignancy of the hematological system, and there are currently a number of studies regarding abnormal alterations in energy metabolism, but fewer reports related to fatty acid metabolism (FAM) in AML. We therefore analyze the association of FAM and AML tumor development to explore targets for clinical prognosis prediction and identify those with potential therapeutic value.

Methods

The identification of AML patients with different fatty acid metabolism characteristics was based on a consensus clustering algorithm. The CIBERSORT algorithm was used to calculate the proportion of infiltrating immune cells. We used Cox regression analysis and least absolute shrinkage and selection operator (LASSO) regression analysis to construct a signature for predicting the prognosis of AML patients. The Genomics of Drug Sensitivity in Cancer database was used to predict the sensitivity of patient samples in high- and low-risk score groups to different chemotherapy drugs.

Results

The consensus clustering approach identified three molecular subtypes of FAM that exhibited significant differences in genomic features such as immunity, metabolism, and inflammation, as well as patient prognosis. The risk-score model we constructed accurately predicted patient outcomes, with area under the receiver operating characteristic curve values of 0.870, 0.878, and 0.950 at 1, 3, and 5 years, respectively. The validation cohort also confirmed the prognostic evaluation performance of the risk score. In addition, higher risk scores were associated with stronger fatty acid metabolisms, significantly higher expression levels of immune checkpoints, and significantly increased infiltration of immunosuppressive cells. Immune functions, such as inflammation promotion, para-inflammation, and type I/II interferon responses, were also significantly activated. These results demonstrated that immunotherapy targeting immune checkpoints and immunosuppressive cells, such as myeloid-derived suppressor cells (MDSCs) and M2 macrophages, are more suitable for patients with high-risk scores. Finally, the prediction results of chemotherapeutic drugs showed that samples in the high-risk score group had greater treatment sensitivity to four chemotherapy drugs in vitro.

Conclusions

The analysis of the molecular patterns of FAM effectively predicted patient prognosis and revealed various tumor microenvironment (TME) characteristics.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12944-022-01687-x.

Recent advances of IDH1 mutant inhibitor in cancer therapy

Isocitrate dehydrogenase (IDH) is the key metabolic enzyme that catalyzes the conversion of isocitrate to α-ketoglutarate (α-KG). Two main types of IDH1 and IDH2 are present in humans. In recent years, mutations in IDH have been observed in several tumors, including glioma, acute myeloid leukemia, and chondrosarcoma. Among them, the frequency of IDH1 mutations is higher than IDH2. IDH1 mutations have been shown to increase the conversion of α-KG to 2-hydroxyglutarate (2-HG). IDH1 mutation-mediated accumulation of 2-HG leads to epigenetic dysregulation, altering gene expression, and impairing cell differentiation. A rapidly emerging therapeutic approach is through the development of small molecule inhibitors targeting mutant IDH1 (mIDH1), as evidenced by the recently approved of the first selective IDH1 mutant inhibitor AG-120 (ivosidenib) for the treatment of IDH1-mutated AML. This review will focus on mIDH1 as a therapeutic target and provide an update on IDH1 mutant inhibitors in development and clinical trials.

Immunotherapy targeting mesothelin in acute myeloid leukemia

Mesothelin (MSLN) is an emerging target that exists in soluble and membrane-associated forms. It is usually used for the diagnosis and treatment of MSLN-positive solid tumors. Interestingly, recent studies have shown that MSLN is highly expressed in 36% of acute myeloid leukemia (AML) patients and barely expressed in normal hematopoietic cells, which makes MSLN a promising target for the treatment of AML. It has been shown that MSLN is detectable as a diagnostic marker in its soluble form. Although the mechanism of action is unclear, MSLN remains a promising target for immunotherapy. Most MSLN research has been conducted in solid tumors, and less research has been conducted in hematopoietic tumors. Increasing research on MSLN is underway in AML, a hematopoietic neoplasm. For example, MSLN is related to extramedullary disease, minimal residual disease, and relapse in AML patients. Decreasing the expression of MSLN reduces the severity of the disease course. This information suggests that MSLN may be an ideal target for the treatment of many AML-related diseases to improve the prognosis and survival rate. At present, there are a few immunotherapies targeting MSLN in AML in preclinical and clinical trials, such as antibody-drug conjugates, bispecific T-cell engagers, and chimeric antigen receptor-T cells, which opens new room for the treatment of MSLN-related AML.

An immunity and pyroptosis gene-pair signature predicts overall survival in acute myeloid leukemia

Treatment responses of patients with acute myeloid leukemia (AML) are known to be heterogeneous, posing challenges for risk scoring and treatment stratification. In this retrospective multi-cohort study, we investigated whether combining pyroptosis- and immune-related genes improves prognostic classification of AML patients. Using a robust gene pairing approach, which effectively eliminates batch effects across heterogeneous patient cohorts and transcriptomic data, we developed an immunity and pyroptosis-related prognostic (IPRP) signature that consists of 15 genes. Using 5 AML cohorts (n = 1327 patients total), we demonstrate that the IPRP score leads to more consistent and accurate survival prediction performance, compared with 10 existing signatures, and that IPRP scoring is widely applicable to various patient cohorts, treatment procedures and transcriptomic technologies. Compared to current standards for AML patient stratification, such as age or ELN2017 risk classification, we demonstrate an added prognostic value of the IPRP risk score for providing improved prediction of AML patients. Our web-tool implementation of the IPRP score and a simple 4-factor nomogram enables practical and robust risk scoring for AML patients. Even though developed for AML patients, our pan-cancer analyses demonstrate a wider application of the IPRP signature for prognostic prediction and analysis of tumor-immune interplay also in multiple solid tumors.

Understanding gilteritinib resistance to FLT3-F691L mutation through an integrated computational strategy

FMS-like tyrosine kinase 3 (FLT3) serves as an important drug target for acute myeloid leukemia (AML), and gene mutations of FLT3 have been closely associated with AML patients with an incidence rate of ~ 30%. However, the mechanism of the clinically relevant F691L gatekeeper mutation conferred resistance to the drug gilteritinib remained poorly understood. In this study, multiple microsecond molecular dynamics (MD) simulations, end-point free energy calculations, and dynamic correlated and network analyses were performed to investigate the molecular basis of gilteritinib resistance to the FLT3-F691L mutation. The simulations revealed that the resistant mutation largely induced the conformational changes of the activation loop (A-loop), the phosphate-binding loop, and the helix αC of the FLT3 protein. The binding abilities of the gilteritinib to the wild-type and the F691L mutant were different through the binding free energy prediction. The simulation results further indicated that the driving force to determine the binding affinity of gilteritinib was derived from the differences in the energy terms of electrostatic and van der Waals interactions. Moreover, the per-residue free energy decomposition suggested that the four residues (Phe803, Gly831, Leu832, and Ala833) located at the A-loop of FLT3 had a significant impact on the binding affinity of gilteritinib to the F691L mutant. This study may provide useful information for the design of novel FLT3 inhibitors specially targeting the F691L gatekeeper mutant.

Targeting stem cells in myelodysplastic syndromes and acute myeloid leukemia

The genetic architecture of cancer has been delineated through advances in high-throughput next-generation sequencing, where the sequential acquisition of recurrent driver mutations initially targeted towards normal cells ultimately leads to malignant transformation. Myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML) are hematologic malignancies frequently initiated by mutations in the normal hematopoietic stem cell compartment leading to the establishment of leukemic stem cells. Although the genetic characterization of MDS and AML has led to identification of new therapeutic targets and development of new promising therapeutic strategies, disease progression, relapse, and treatment-related mortality remain a major challenge in MDS and AML. The selective persistence of rare leukemic stem cells following therapy-induced remission implies unique resistance mechanisms of leukemic stem cells towards conventional therapeutic strategies and that leukemic stem cells represent the cellular origin of relapse. Therefore, targeted surveillance of leukemic stem cells following therapy should, in the future, allow better prediction of relapse and disease progression, but is currently challenged by our restricted ability to distinguish leukemic stem cells from other leukemic cells and residual normal cells. To advance current and new clinical strategies for the treatment of MDS and AML, there is a need to improve our understanding and characterization of MDS and AML stem cells at the cellular, molecular, and genetic levels. Such work has already led to the identification of promising new candidate leukemic stem cell molecular targets that can now be exploited in preclinical and clinical therapeutic strategies, towards more efficient and specific elimination of leukemic stem cells.

Application of precision medicine in clinical routine in haematology-Challenges and opportunities

Precision medicine is revolutionising patient care in cancer. As more knowledge is gained about the impact of specific genetic lesions on diagnosis, prognosis and treatment response, diagnostic precision and the possibility for optimal individual treatment choice have improved. Identification of hallmark genetic aberrations such as the BCR::ABL1 gene fusion in chronic myeloid leukaemia (CML) led to the rapid development of efficient targeted therapy and molecular follow-up, vastly improving survival for patients with CML during recent decades. The assessment of translocations, copy number changes and point mutations are crucial for the diagnosis and risk stratification of acute myeloid leukaemia and myelodysplastic syndromes. Still, the often heterogeneous and complex genetic landscape of haematological malignancies presents several challenges for the implementation of precision medicine to guide diagnosis, prognosis and treatment choice. This review provides an introduction and overview of the important molecular characteristics and methods currently applied in clinical practice to guide clinical decision making in haematological malignancies of myeloid and lymphoid origin. Further, experimental ways to guide the choice of targeted therapy for refractory patients are reviewed, such as functional precision medicine using drug profiling. An example of the use of pipeline studies where the treatment is chosen according to the molecular characteristics in rare solid malignancies is also provided. Finally, the future opportunities and remaining challenges of precision medicine in the real world are discussed.