Acute myeloid leukemia (AML) is one of the most common and lethal hematologic malignancies with limited possibilities for treatment. Thus, more effective therapeutic drugs are imperatively needed to fulfill current unmet medical requirements. Luteoloside, derived from the traditional Chinese medicine Lonicera japonica, demonstrates potent anti-tumor activity against solid tumors, but its effects and mechanisms in hematologic malignancies like AML remain unclear. Herein, we found that luteoloside dramatically impaired the proliferation and clonogenic capacity of AML cells and induced cell cycle arrest and reduced the cells at S phase. Furthermore, luteoloside induced apoptosis and promoted differentiation of these cells. Mechanism analysis revealed that luteoloside attenuated β-catenin in the nucleus, thereby reducing the expression of its downstream effector c-Myc. Activation of Wnt/β-catenin signaling by a GSK-3β inhibitor LiCl reversed the inhibitory effect of luteoloside on AML cell proliferation, apoptosis, and differentiation. Luteoloside significantly reduced the transplantation rate of primary AML cells in a patient-derived xenografts (PDX) model. Combined treatment with luteoloside and cytarabine (Ara-C) showed a synergistic anti-AML effect in vitro, and markedly reduced leukemia burden and prolonged the survival in the orthotopic C1498 murine AML model. Collectively, our findings demonstrate that luteoloside suppresses AML cell proliferation, induces apoptosis and differentiation by targeting the β-catenin/c-Myc axis, and exhibits synergistic effects with Ara-C. These results underscore its potential as a promising adjunctive therapy for AML.

BACKGROUND:The Signaling Lymphocyte Activation Molecule (SLAM) receptor family regulates immune homeostasis across diverse immune cells. This study investigates the immunomodulatory role of CD244 in CD8+T cells within the acute myeloid leukemia (AML) bone marrow microenvironment. METHODS:Using pan-cancer analysis, Gene Expression Omnibus (GEO) datasets, functional experiments, and orthotopic AML mouse models, we systematically evaluated CD244 expression and its correlations with gene mutations, clinical prognosis, and immune microenvironment profiles in AML. RESULTS:Pan-cancer analysis revealed high CD244 expression in AML, associated with poor prognosis. GSE6891 data showed biallelic CEBPA mutations upregulated CD244, while NPM1 mutations had lower expression. TCGA-LAML analysis linked CD244 to immune cell infiltration. Flow cytometry validated elevated CD244 on bone marrow-infiltrating CD8+T cells, predominantly on terminally differentiated effector memory T subsets in AML patients, with impaired cytokine secretion compared to healthy controls. Orthotopic AML mouse models also confirmed enhanced CD244 expression in CD62Llow/highCD44high CD8+T cell subsets. Additionally, CD244 correlated positively with CD161/CD57 and negatively with CD27. And anti-CD244 antibody could significantly enhance T-cell-mediated anti-AML efficacy in cytotoxicity assays. CONCLUSIONS:CD244 drives immunomodulation via dysregulated CD8+T cell differentiation and cytokine secretion, positioning it as a prognostic biomarker and a promising target for immunotherapy in AML.

Acute myeloid leukemia (AML) is a frequently fatal malignancy of bone marrow stem/progenitor cells. Fibrinogen (Fg), the predominant coagulation factor in plasma, has been reported to have a negative correlation with the prognosis of AML patients. However, the underlying mechanisms through which Fg exerts its effects on AML remain unclear. In this study, we developed a Fg-deficient AML mouse model and utilized AML cell lines and primary human AML cells to explore the role of Fg in AML progression both in vivo and in vitro. Our findings demonstrate that Fg significantly accelerates AML progression in a cancer xenograft model, as well as primary cells from untreated patients with AML. Mechanistically, Fg upregulates the expression of miR-486-5p, which directly targets the orphan receptor GPR153. This interaction activates the downstream mTORC2/AKT signaling pathway, driving AML cell proliferation and migration. Our results highlight a critical molecular mechanism by which Fg contributes to AML progression, offering potential molecular targets for therapeutic intervention.

Acute myeloid leukemia (AML) is defined by epigenetic heterogeneity, and recurrent mutations in chromatin remodelers are associated with a poor prognosis. Whether these mutations drive treatment resistance through remodeling of the tumor immune microenvironment remains unclear. ARID1B, a recurrently mutated SWI/SNF subunit in AML, has an uncertain association with adverse outcomes, and its immunomodulatory role remains undefined. This study characterized the clinical, genomic, and immunological features of ARID1B-mutant AML and assessed their impact on treatment response and prognosis. ARID1B mutations displayed clinical heterogeneity. Patients harboring the p.Gly332_Ala336del variant achieved significantly higher rates of complete remission and overall response to induction chemotherapy compared with those carrying other ARID1B mutations. Prognostic impact was context-dependent: ARID1B mutation conferred inferior survival specifically in acute promyelocytic leukemia and in patients aged ≥65 years. Mechanistically, ARID1B mutations were associated with an immunosuppressive microenvironment, characterized by upregulated VISTA expression on leukemic blasts, reduced bone marrow CD8+ T-cell infiltration, and impaired effector function of both CD8+ T cells and NK cells. These findings suggest that ARID1B mutations in AML have dual implications: the p.Gly332_Ala336del variant enhances chemosensitivity, while ARID1B dysfunction broadly facilitates an immune- evasive phenotype, likely through VISTA-mediated suppression. This study identifies ARID1B mutation as a conditional prognostic marker and a correlate of the AML immune landscape, thereby supporting mutation-subtype-specific management and therapeutic targeting of the VISTA pathway.

IntroductionBone marrow involvement (BMI) is a poor prognostic factor in diffuse large B cell lymphoma (DLBCL), and accurate evaluation of BMI is crucial for determining stages and prognosis. This study aimed to identify the most effective examinations for evaluating BMI in DLBCL, including positron emission tomography-computed tomography (PET/CT), immunoglobulin gene rearrangement (IGR), flow cytometry (FCM), bone marrow cytology (BMC) and bone marrow biopsy pathology (BMB), and to further explore its prognostic significance in DLBCL patients.MethodsThis retrospective study included 364 newly diagnosed DLBCL patients, all of whom underwent PET/CT, IGR, FCM, BMC, and BMB at diagnosis. Survival outcomes were analyzed via Kaplan-Meier and Cox regression models. Novel prognostic models incorporating combined IGR and BMB results were developed in a training cohort.ResultsCompared to other detection methods, Clonal IGR BMI-positive were found the highest rate of 114 patients (31.3%), and IGR BM involvement-positive patients of DLBCL had the worst survival outcomes, especially among patients in stages I to III (P<0.001). Notably, PET/CT existed some limitations in BMI diagnosis, particularly in stage IV patients (P>0.05). Additionally, the combination of IGR and BMB demonstrated superior prognostic predictive capability for the patients in stage IV (PP<0.001). Multivariate analysis further confirmed that double-positive BMI of IGR and BMB was an independent prognostic factors of PFS (P=0.026) and OS (P=0.042). In addition, the novel IPI and NCCN-IPI stratification models were established by incorporating the combination of IGR and BMB in training group. The C-index of novel models were increased when IGR and BMB were supplemented in our cohort.DiscussionOur results suggest that IGR is the most valuable methods for evaluating BMI compared to traditional detection methods. Adding the combination of IGR and BMB to the IPI and NCCN-IPI score may improve their predictive ability. In summary, IGR is essental for evaluation of BMI and provide an ideal method for disease staging and risk stratification in DLBCL patients in the rituximab era.

Exposure to benzene causes acute myelosuppression and other hematologic disorders. However, the detailed mechanism by which benzene exerts its severe hematotoxicity and potential treatments still require further deciphering and exploration. Herein, we found that hydroquinone (HQ), a main benzene metabolite, significantly increased intracellular reactive oxygen species (ROS) formation and subsequently caused damage to DNA, leading to impaired colony formation capacity and induction of apoptosis in human hematopoietic stem/progenitor cells (HSPCs) in vitro. The effects were mediated by activation of Src kinase, which subsequently activated the p38 signaling pathway while inhibiting the Akt signaling pathway. The mechanism was further verified by pre-treatment with a Src kinase inhibitor SKI-606, which effectively reversed the dampened self-renewal capacity and increased apoptosis of HSPCs induced by HQ in vitro. Furthermore, administration of SKI-606 partially reversed benzene-induced hematotoxicity and prolonged the survival time in benzene-poisoned mice. Taken together, these findings highlight that HQ-induced hematotoxicity in HSPCs is attributed to the Src kinase-mediated activation of p38 signaling pathway and repression of Akt signaling pathway. Notably, SKI-606 as a tyrosine kinase inhibitor may be a promising and potential agent for alleviating benzene-induced hematotoxicity.

EDITORIAL article Front. Immunol., 04 April 2023Sec. Cancer Immunity and Immunotherapy Volume 14 - 2023 | https://doi.org/10.3389/fimmu.2023.1188582

CD44 is a ubiquitous leukocyte adhesion molecule involved in cell-cell interaction, cell adhesion, migration, homing and differentiation. CD44 can mediate the interaction between leukemic stem cells and the surrounding extracellular matrix, thereby inducing a cascade of signaling pathways to regulate their various behaviors. In this review, we focus on the impact of CD44s/CD44v as biomarkers in leukemia development and discuss the current research and prospects for CD44-related interventions in clinical application.

Despite significant advancements in multiple myeloma (MM) treatment in recent years, most patients will eventually develop resistance or experience relapse. Matrine, a primary active compound of traditional Chinese medicinal herb Sophora flavescens Ait, has been found to have anti-tumor properties in various types of malignant tumors. Whether autophagy plays a crucial role in the anti-MM effect of matrine remain unknown. Herein, we found that matrine could trigger apoptosis and cell cycle arrest, and meanwhile induce autophagy in MM cells in vitro. We further ascertained the role of autophagy by using ATG5 siRNA or the autophagy inhibitor spautin-1, which partially reversed matrine's inhibitory effect on MM cells. Conversely, the combination of matrine with the autophagy inducer rapamycin enhanced their anti-tumor activity. These findings suggest that autophagy induced by matrine can lead to cell death in MM cells. Further mechanism investigation revealed that matrine treatment increased the levels of reactive oxygen species (ROS) and AMPK alpha 1 phosphorylation and decreased the phosphorylation of mTOR in MM cells. Additionally, co-treatment with AMPK alpha 1 siRNA or the ROS scavenger Nacetyl-1-cysteine weakened the increase in autophagy that was induced by matrine. Finally, we demonstrated a synergistic inhibitory effect of matrine and rapamycin against MM in a xenograft mouse model. Collectively, our findings provided novel insights into the anti-MM efficacy of matrine and suggest that matrine induces autophagy by triggering ROS/AMPK/mTOR axis in MM cells, and combinatorial treatment of matrine and rapamycin may be a promising therapeutic strategy against MM.

Despite significant advancements in multiple myeloma (MM) treatment in recent years, most patients will eventually develop resistance or experience relapse. Matrine, a primary active compound of traditional Chinese medicinal herb Sophora flavescens Ait, has been found to have anti-tumor properties in various types of malignant tumors. Whether autophagy plays a crucial role in the anti-MM effect of matrine remain unknown. Herein, we found that matrine could trigger apoptosis and cell cycle arrest, and meanwhile induce autophagy in MM cells in vitro. We further ascertained the role of autophagy by using ATG5 siRNA or the autophagy inhibitor spautin-1, which partially reversed matrine’s inhibitory effect on MM cells. Conversely, the combination of matrine with the autophagy inducer rapamycin enhanced their anti-tumor activity. These findings suggest that autophagy induced by matrine can lead to cell death in MM cells. Further mechanism investigation revealed that matrine treatment increased the levels of reactive oxygen species (ROS) and AMPKα1 phosphorylation and decreased the phosphorylation of mTOR in MM cells. Additionally, co-treatment with AMPKα1 siRNA or the ROS scavenger N-acetyl-1-cysteine weakened the increase in autophagy that was induced by matrine. Finally, we demonstrated a synergistic inhibitory effect of matrine and rapamycin against MM in a xenograft mouse model. Collectively, our findings provided novel insights into the anti-MM efficacy of matrine and suggest that matrine induces autophagy by triggering ROS/AMPK/mTOR axis in MM cells, and combinatorial treatment of matrine and rapamycin may be a promising therapeutic strategy against MM.

The unexpensive and readily available biomarkers for CRS grading and prognosis assessment in CAR-T therapy are currently lacking. This study included 27 patients with relapsed/refractory MM who were treated with CAR-T cells. Our results suggest that ALP levels after CAR-T therapy could serve as a suitable biomarker for monitoring CAR-T cell proliferation, CRS grading, and prognosis in patients with MM.Background: The inexpensive and readily available biomarkers for cytokine release syndrome (CRS) grading and prognosis assessment in chimeric antigen receptor (CAR)-T therapy are currently lacking. This study examined the significance of alkaline phosphatase (ALP) after CAR-T therapy in patients with relapsed/refractory multiple myeloma (MM). Methods: This cohort study included 27 patients with relapsed/refractory MM who were treated with CAR-T cells between December 2017 and October 2021. Patients were classified into 2 groups: normal ALP group (peak ALP < 125 U/L, n = 10) and high ALP group (peak ALP >=;125 U/L, n = 17). Results: Within 1 month of CAR-T cell infusion, the incidence of ALP increases was 63%. We found that ALP levels began to rise in the second week, peaked in the third and fourth weeks, and began to decline in the second month. Moreover, the ALP levels in previous chemotherapy-responsive period were significantly lower than those after CAR-T therapy. Statistical analysis found that patients with increased ALP exhibited higher alanine aminotransferase and aspartate aminotransferase levels, higher and longer CAR-T cell proliferation, more serious CRS, higher cytokine and ferritin levels, and higher initial response rates. In addition, the duration of ALP increase was parallel to the duration of CAR-T expansion. Multivariable Cox-regression analysis showed that peak ALP was the independent predictor for progression-free survival (PFS) (HR = 0.029, 95% CI: 0.002-0.369). Conclusions: Our results suggest that the ALP levels after CAR-T therapy could serve as a suitable biomarker for monitoring CAR-T cell proliferation, CRS grading, and prognosis in patients with MM.

Perturbations in autophagy, apoptosis and differentiation have greatly affected the progression and therapy of acute myeloid leukaemia (AML). The role of X-linked inhibitor of apoptosis (XIAP)-related autophagy remains unclear in AML therapeutics. Here, we found that XIAP was highly expressed and associated with poor overall survival in patients with AML. Furthermore, pharmacologic inhibition of XIAP using birinapant or XIAP knockdown via siRNA impaired the proliferation and clonogenic capacity by inducing autophagy and apoptosis in AML cells. Intriguingly, birinapant-induced cell death was aggravated in combination with ATG5 siRNA or an autophagy inhibitor spautin-1, suggesting that autophagy may be a pro-survival signalling. Spautin-1 further enhanced the ROS level and myeloid differentiation in THP-1 cells treated with birinapant. The mechanism analysis showed that XIAP interacted with MDM2 and p53, and XIAP inhibition notably downregulated p53, substantially increased the AMPKα1 phosphorylation and downregulated the mTOR phosphorylation. Combined treatment using birinapant and chloroquine significantly retarded AML progression in both a subcutaneous xenograft model injected with HEL cells and an orthotopic xenograft model injected intravenously with C1498 cells. Collectively, our data suggested that XIAP inhibition can induce autophagy, apoptosis and differentiation, and combined inhibition of XIAP and autophagy may be a promising therapeutic strategy for AML.

BACKGROUND:The previous studies have revealed that abnormal RNA-binding protein Musashi-2 (MSI2) expression is associated with cancer progression through post-transcriptional mechanisms, however mechanistic details of this regulation in acute myeloid leukemia (AML) still remain unclear. Our study aimed to explore the relationship between microRNA-143 (miR-143) and MSI2 and to clarify their clinical significance, biological function and mechanism.METHODS:Abnormal expression of miR-143 and MSI2 were evaluated in bone marrow samples from AML patients by quantitative real time-PCR. Effects of miR-143 on regulating MSI2 expression were investigated using luciferase reporter assay. Functional roles of MSI2 and miR-143 on AML cell proliferation and migration were determined by CCK-8 assay, colony formation, and transwell assays in vitro and in mouse subcutaneous xenograft and orthotopic transplantation models in vivo. RNA immunoprecipitation, RNA stability measurement and Western blotting were performed to assess the effects of MSI2 on AML.RESULTS:We found that MSI2 was significantly overexpressed in AML and exerted its role of promoting AML cell growth by targeting DLL1 and thereby activating Notch signaling pathway. Moreover, we found that MSI2 bound to Snail1 transcript and inhibited its degradation, which in turn upregulated the expression of matrix metalloproteinases. We also found that MSI2 targeting miR-143 is downregulated in AML. In the AML xenograft mouse model, overexpression of MSI2 recapitulated its leukemia-promoting effects, and overexpression of miR-143 partially attenuated tumor growth and prevented metastasis. Notably, low expression of miR-143, and high expression of MSI2 were associated with poor prognosis in AML patients.CONCLUSIONS:Our data demonstrate that MSI2 exerts its malignant properties via DLL1/Notch1 cascade and the Snail1/MMPs axes in AML, and upregulation of miR-143 may be a potential therapeutic approach for AML.

Background: The T-cell non-Hodgkin's lymphoma (T-NHL) patients with bone marrow (BM) invasion have a poor prognosis. Although BM biopsy is still a confirmed diagnosis method, the low sensitivity restricts its use to detect the minimal BM invasion. It is of great clinical significance to establish a rapid and highly sensitive method to evaluate BM invasion. Methods: We conducted a retrospective study of 85 patients with new diagnosed T-NHL patients enrolled in our institute. The bone marrow mononuclear cells (BMMNCs) cells were isolated, stained with different combinations of antibody and subjected to flow cytometry analysis. Results: We found that CD3(+)CD7(-) T cells increased significantly in the BM in T-NI IL patients with BM invasion. The patients were divided into the low and high groups according to the cutoff value of 1.035% obtained by analyzing the receiver operating characteristic (ROC) curve of the percentage of CD3(+)CD7(-) T cells of nucleated cells at diagnosis. The ratio of invasion in high group was markedly higher than that in low group. Furthermore, CD3(+)CD7(-) T cells presented significantly higher level of programmed cell death-1 (PD-1), lymphocyte-activation-gene-3 (LAG3) and CD4/CD8 ratio. Conclusions: Our study revealed the percentage of CD3(+)CD7(-) T cells of nucleated cells in BM was a potential diagnostic predictor of BM invasion with T-NHL.

Platelets are the smallest non-nucleated cells in the blood circulation, and their specific morphological structure and biochemical composition make them play a key role in physiological hemostasis and pathological thrombosis (Zhao, Zhang et al. 2021). But recently, platelets are also widely recognized as novel biomarkers and therapeutic targets for related diseases such as inflammation, immunity and tumors. Hematologic toxicity is a common adverse event associated with chimeric antigen receptor (CAR) T-cell therapy (Rejeski, Perez et al. 2021). Liu et al. showed that high incidence of platelet transfusion refractoriness (PTR) occurred in CAR-T therapy for relapsed/refractory acute lymphoblastic leukemia (R/R ALL), and the levels of IL-6 and IFN-γ in cytokine release syndrome (CRS) were positively correlated with PTR (Liu et al.). PTR is a high-risk factor for hemorrhagic death. Endothelial activation drives the mechanism of CAR-T cell-mediated toxicity, suggesting that common laboratory parameters prior to lymphocyte depletion correlate with CAR-T-related toxicity (Greenbaum, Strati et al. 2021). Therefore, an in-depth understanding of the mechanism of PTR can significantly counteract the risk of hemorrhagic death in CAR-T cell therapy, thereby improving the transfusion efficiency and disease treatment outcomes.

Cytokine release syndrome (CRS) is the most common on-target toxicity of chimeric antigen receptor (CAR) T cell therapy. However, the prognostic significance of CRS has not been well elucidated. The aim of our study was to evaluate the association between CRS and efficacy after anti-CD19 CAR-T therapy in a retrospective cohort of 22 patients with relapsed/refractory B cell hematological malignancies. The complete remission (CR) rates after CAR-T therapy were 68%, and median value for progression-free survival (PFS) was 6.8 months. Eight of 22 (36.4%) patients showed ≥ grade 2 CRS. Statistical analysis found that patients with ≥ grade 2 CRS had higher CR rates and longer PFS than those with < grade 2 CRS. Moreover, bridging hematopoietic stem cell transplantation was another independent predictor for PFS. These data suggested that appropriate CRS may be beneficial to the efficacy of CAR-T therapy. The Clinical Trial Registration number is NCT03110640, NCT03302403.

BACKGROUND:Neutrophil-to-lymphocyte (NLR) ratio can predict survival outcome and assess response to chemotherapy in several tumors. However, the values of NLR in acute myeloid leukemia (AML) remains unknown.METHODS:A retrospective review of 181 patients with de novo AML excluding acute promyelocytic leukemia (M3) was conducted in our institute. We categorized the patients into two groups by defining NLR =2.0 as the cut-off point. NLR was calculated by the ratio of the number of neutrophils to lymphocytes in the peripheral blood (PB). The baseline clinicopathologic parameters were compared using Chi-squared test or Kruskal-Wallis H test. Kaplan-Meier analysis was used to assess survival, and overall survival (OS) and disease-free survival (DFS) were analyzed using the Cox regression with log-rank tests.RESULTS:We found AML patients with low NLR (<2.0) had longer OS and DFS than those with high NLR (≥2.0). NLR, absolute neutrophil count (ANC), and absolute lymphocyte count (ALC) were significantly associated with OS and DFS in all AML patients. NLR, ANC, and ALC were associated with OS and DFS only in those case with myeloblasts over 50% in bone marrow (BM). Furthermore, the median NLR was dramatically increased in low NLR group when patients achieved complete remission (CR).CONCLUSIONS:Pretreatment NLR as a marker can predict the prognosis and NLR can assess the response to chemotherapy in patients with non-M3 AML, especially in those cases with myeloblasts over 50% in BM.

BACKGROUND:Iron overload, which is common in patients with haematological disorders, is known to have a suppressive effect on haematogenesis. However, the mechanism for this effect is still unclear. The antioxidant curcumin has been reported to protect against iron overload-induced bone marrow damage through an as-yet-unknown mechanism.METHODS:We established iron overload cell and mouse models. Mitochondrial reactive oxygen species (mROS) levels, autophagy levels and the SIRT3/SOD2 pathway were examined in the models and in the bone marrow of patients with iron overload.RESULTS:Iron overload was shown to depress haematogenesis and induce mitochondrion-derived superoxide anion-dependent autophagic cell death. Iron loading decreased SIRT3 protein expression, promoted an increase in SOD2, and led to the elevation of mROS. Overexpression of SIRT3 reversed these effects. Curcumin treatment ameliorated peripheral blood cells generation, enhanced SIRT3 activity, decreased SOD2 acetylation, inhibited mROS production, and suppressed iron loading-induced autophagy.CONCLUSIONS:Our results suggest that curcumin exerts a protective effect on bone marrow by reducing mROS-stimulated autophagic cell death in a manner dependent on the SIRT3/SOD2 pathway.

Intratumoral accumulation of CD4+CD25+Foxp3+ regulatory T (Treg) cells occurs in acute myeloid leukemia (AML), but little is known about the role of tumor cells themselves in this process. Here, we showed that an immune checkpoint PD-L1 expressed by AML cells promoted the conversion and expansion of Treg cells sustaining high expression of Foxp3 and PD-1 as well as a suppressive function. Furthermore, an AML cell line HEL overexpressed PD-L1 promoted the conversion and expansion of Treg cells and CD4+PD-1+Foxp3+ T (PD-1+Treg) cells from the conventional CD4+ T cells. CD4+CD25highPD-1+ T cells secreted more IL-10 production than CD4+CD25highPD-1- T cells. IL-35, another cytokine secreted by Treg cells, promoted the proliferation of HL-60 cells and enhanced chemoresistance to cytarabine. Blockade of PD-1 signaling using anti-PD-L1 antibody dramatically impaired the generation of Treg cells and sharply retarded the progression of a murine AML model injected with C1498 cells. The frequency of intratumoral PD-1+ Treg cells was capable of predicting patient survival in patients with AML. In conclusion, our data suggest that PD-L1 expression by AML cells may directly drive Treg cell expansion as a mechanism of immune evasion and the frequency of PD-1+ Treg cells is a potential prognostic predictor in patients with AML.