DR4/5 agonist Aponermin 治疗急性巨核细胞白血病的疗效及机制研究

Hematological malignancies encompass a diverse range of blood-related cancers characterized by abnormal blood cell production. These cancers, classified by the World Health Organization based on lineage, cell origin, and progression, provide a more comprehensive framework for understanding cancer biology. This classification has significantly advanced cancer research, particularly in genetic analyses for diagnosis and treatment. Despite recent clinical improvements, challenges, such as relapse, resistance, and high mortality, remain unresolved. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), a protein that induces apoptosis in cancer cells without affecting normal cells, has emerged as a promising therapeutic target. However, its clinical efficacy is limited by factors, such as tumor heterogeneity and resistance to TRAIL signaling. This review examines the mechanisms of TRAIL in hematological malignancies, factors contributing to resistance, and the current state of preclinical and clinical research, highlighting potential strategies to enhance TRAIL-based therapies in blood cancers.

Fusion proteins combining TNF-related apoptosis inducing ligand (TRAIL) and antibody building blocks have emerged as a strategy for the targeted treatment of cancer cells. Using a single-chain derivative of homotrimeric TRAIL (scTRAIL), several targeted and non-targeted scTRAIL fusion proteins of varying geometries and valencies for TRAIL receptors and target antigens, all comprising an Fc region, were generated. These fusion proteins comprised either 1 or 2 scTRAIL units, i.e. are tri- or hexavalent for TRAIL receptors and in the targeted versions, 1 or 2 binding sites for EGFR. These fusion proteins were analyzed for cell binding and cell death induction using the EGFR-expressing colorectal cancer cell lines Colo205 and HCT116. In line with previous findings, all fusion proteins that were hexavalent for TRAIL receptors exhibited a strongly increased cell killing activity compared to the trivalent ones. Interestingly, the fusion proteins comprising one scTRAIL unit, did not benefit from targeting to EGFR. In contrast, the hexavalent scTRAIL fusion proteins further benefited from EGFR targeting, resulting in an approximately 6- to 30-fold increase in cell killing. In summary, this study shed further light on the influence of geometry and valency of TRAIL fusion proteins and confirmed IgG-scTRAIL fusion proteins as highly potent cell death inducers.

… among the subtypes, a predominant expression of DR4 was detected in early subtypes AML M2 and M3, while DR5 expression is considerably enhanced in the later subtype AML M7 …

… This article summarizes the milestones in the development of aponermin leading to this first … with aponermin to enhance apoptosis in aponermin-resistant human MM and leukaemia cell …

Background: Multiple myeloma (MM) is still an incurable neoplasm, and treatment options for heavily pretreated relapsed and refractory multiple myeloma (RRMM) are still limited. Aponermin is a recombinant circularly permuted human tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), which can activate death receptor 4 (DR4)/death receptor 5 (DR5) on the surface of tumor cells, triggering intracellular caspase reactions and exerting anti-tumor effects. Aponermin received its first approval in China for the treatment of patients with relapsed or refractory multiple myeloma who have received at least two prior therapies (Dhillon S, Drugs, 2024; Xia Z,Leng Y, Fang B, BMC Cancer, 2023). It could synergize with proteasome inhibitors and corticosteroids to enhance antimyeloma activity (Leng Y, Hematol Oncol, 2022). Here we report the efficacy and safety of aponermin-carfilzomib-dexamethasone (Apo-KD) based regimens for RRMM. Methods: This is a prospective, multi-center study (ChiCTR2500100365) involving patients with RRMM who had received at least two prior lines of therapy. Apo-KD was adminstered in 28-day treatment cycles as follows: aponermin (10mg/kg on days 1–5 per cycle, or alternatively on days 1–3 and 15–17 per cycle), carfilzomib (20 mg/m² on days 1 and 2 of Cycle 1; 27 mg/m² on days 1 and 2 of Cycle 2 and subsequent cycles), and dexamethasone (20 mg on days 1, 2, 8, 9, 15, 16, 22, and 23 per cycle). Other medications, such as immunomodulatory drugs or chemotherapy agents, were allowed based on the patient's disease status and tolerance (Jun Ma, Leukemia & Lymphoma, 2024). The primary endpoint was the overall response rate (ORR) according to IMWG criteria. Secondary endpoints included the response rate of at least very good partial response (VGPR), progression-free survival (PFS), overall survival (OS), duration of response (DOR), and safety. Results: As of July 10, 2025, 40 patients were recruited to the study, with a median age of 62 years (range, 38–78) and a median of 4 prior lines of therapy (range, 2–13). Baseline characteristics included 40% of patients classified as ISS Stage III, and 37.5% with high-risk cytogenetics. Extramedullary disease (EMD) was documented in 28 patients (70%), and 40.0% had previously undergone autologous stem cell transplantation (ASCT) as first-line therapy. In terms of prior treatments, 80% had been exposed to immunomodulatory drugs, proteasome inhibitors (PIs), and anti-CD38 antibodies (triple-class exposure [TCE]), while 15/40 (37.5%) had been treated with BCMA-CD3 antibodies or CAR-T therapy. Treatment regimens included Apo-KD in 10 patients (25%), Apo-KD combined with immunomodulatory drugs (IMiDs) in 12 patients (30%), and Apo-KD combined with chemotherapy in 18 patients (45%). The median number of treatment cycles was 3 (range, 2–8). The ORR was 70% (95% CI: 53.3%-82.9%), with a VGPR rate of 32.5% (95% CI: 19.1%-40.2%). Among patients with EMD, the ORR was 71.3%, and the VGPR rate was 32.1%. In the subgroup of 32 TCE patients, the ORR was 65.6%, with 31.3% achieving VGPR. Fifteen patients who had undergone prior CAR-T or BCMA-CD3 antibody treatment showed an ORR of 80.0% (20.0% complete response [CR], 20.0% VGPR, and 40.0% partial response [PR]). The efficacy of the Apo-KD-based regimens was similar in patients with extramedullary disease, TCE, or those previously treated with CAR-T/ bispecific antibody. The median follow-up period was 4 months (range: 2-12). Nine patients experienced disease progression. The estimated median PFS was 11.4 months (95% CI: 4.8–17.2). Three patients died due to disease progression, and the median OS was not reached. The most common treatment-emergent adverse events (TEAEs) were bone marrow suppression (62.5%), infections (40%), elevated transaminases (25%), fatigue (12.5%), hyperuricemia (10%), and hypokalemia (10%). Notably, grade III or higher TEAEs were reported in 42.5% for cytopenia and 12.5% for infections. Conclusion: The aponermin-carfilzomib-dexamethasone (Apo-KD)-based regimens demonstrated promising activity in heavily pretreated patients with RRMM, especially those with EMD, TCE, or T-cell-redirecting therapies. The adverse events were manageable.

Introduction Chimeric antigen receptor (CAR) T-cell therapy represents a breakthrough in the treatment of relapsed or refractory (R/R) multiple myeloma (MM), however, severe cytokine release syndrome and neurotoxicity may compromise outcomes. A well-tolerated bridging therapy that controls disease without additional toxicities could improve the safety and efficacy of subsequent CAR-T infusion. Aponermin, a novel circularly permuted TRAIL ligand, induces selective apoptosis in malignant plasma cells through death receptors DR4 and DR5 (Dhillon S, Drugs, 2024; Xia Z, Leng Y, Fang B, BMC Cancer, 2023). The safety and efficacy of aponermin-based regimens as bridging therapy before CAR-T treatment remain to be explored. Methods We performed a retrospective, three-centre cohort study of consecutive RRMM patients who received aponermin-based chemotherapy after leukapheresis and before lymphodepletion (fludarabine 30 mg/m²/day and cyclophosphamide 300 mg/m²/day × 3 days) followed by a single BCMA CAR-T infusion. Safety and efficacy were assessed from the start of bridging therapy until 30 days after CAR-T administration. Results Twenty-eight patients with R/R MM were enrolled. All had received a median of four prior lines of therapy (range 3–7). Among them, 27 patients presented with extramedullary disease. All patients were refractory to proteasome inhibitors, immunomodulatory drugs, and CD38 monoclonal antibodies. Of the 28 patients, 23 received one cycle of bridging therapy, 3 received two cycles, and 1 patient received three cycles. After aponermin-based bridging therapy, the overall response rate (ORR) was 41.7% (7/28), including a complete response (CR) in 7.1% (2/28) patients and a partial response (PR) in 17.9% (5/28) patients. Stable disease (SD) was observed in 17 (60.7%) patients, and 2 (7.1%) patients experienced disease progression after bridging therapy. The safety profile of bridging therapy was favorable, with only one case of hypersensitivity reaction and two cases of elevated transaminases. Notably, six patients with stable disease after bridging therapy experienced significant platelet elevation after bridging therapy, potentially reducing bleeding risk during subsequent CAR-T cell treatment. Among 23 evaluable patients after CAR-T cell treatment, the ORR was 95.7 % (sCR 4.3 %, CR 17.4 %, PR 52.2 %). The median progression-free survival (PFS) was 6.43 months. Conclusion: Aponermin-based bridging therapy is well tolerated, does not exacerbate organ dysfunction or marrow suppression, and provides significant disease control or platelet recovery. These findings support prospective evaluation of aponermin-based regimens as an effective bridge to BCMA CAR-T therapy in R/R MM.

Drug-induced liver injury (DILI) remains an active field of clinical research and investigation with more than 4700 publications appearing in 2023 relating to hepatotoxicity of all causes …

PANoptosis is closely associated with tumorigenesis and therapeutic response, yet its role in multiple myeloma (MM) remains unclear. This study analyzed bulk transcriptomic and clinical data from the TCGA and GEO databases to identify seven PANoptosis-related genes (PRGs) using machine learning (LASSO regression and random forest models) and univariate Cox analysis, and constructed a prognostic risk model. The model demonstrated robust predictive performance across three external validation cohorts. High-risk patients exhibited higher tumor purity, increased tumor mutational burden, and distinct immune cell infiltration patterns. Drug sensitivity analysis revealed heightened sensitivity to cyclophosphamide, Sinularin, Wee1 inhibitor, osimertinib, JQ1, VE-822, and AZD6738 in high-risk patients. Single-cell transcriptomic analysis revealed significant enrichment of PARP1, ZBP1, LY96, and CASP3 in plasma cells. Quantitative PCR (qPCR) further validated differential expression patterns of the seven core PRGs between MM patients and healthy controls. Immunohistochemical analysis demonstrated distinct expression profiles of PARP1, ZBP1, LY96, and CASP3 in high-risk versus standard-risk MM patients. Furthermore, CCK-8 assays and Wright-Giemsa staining confirmed the crucial role of PARP1 in regulating MM cell viability. This PANoptosis-based prognostic model provides a valuable tool for predicting MM prognosis and guiding personalized treatment. Supplementary Information The online version contains supplementary material available at 10.1038/s41598-025-06376-0.

The efficient tumor ablation strategy accompanied with metastasis blocking is critical for triple-negative breast cancer (TNBC) therapy. Herein, we develop a cascade pH-responsive …

It is well known that tumor necrosis factor-related apoptosis inducing ligand receptor 1 or 2 (DR4/DR5) is specifically expressed in various tumor cells, but less or no expression in most normal cells. Many first generations of TRAIL agonists including recombinant preparations of TRAIL, agonistic antibodies against DR4/DR5 have been developed in phase I/II clinical trials for cancer therapy. However, the outcomes of clinical trials by using DR4/DR5 agonist mono-therapy were disappointed even though the safety profile was well tolerance. In the present study, we report an anti-DR5 antibody-drug conjugate (ADC, named as Zapadcine-1) possesses a higher potential for the therapy of lymphocyte leukemia and solid cancers. Methods: Zapadcine-1 was made by a fully humanized DR5-specific monoclonal antibody (Zaptuzumab) coupled via a cleavable linker to a highly toxic inhibitor of tubulin, monomethyl auristatin D (MMAD), by using ThioBridge technology. Cytotoxicity of the ADC in various tumor cells was identified by luminescent cell viability assay and the efficacy in vivo was determined in cells derived xenografts (CDX) of Jurkat E6-1, BALL-1, Reh, and patient derived xenografts (PDX) of human acute leukemia. Preliminary safety evaluation was carried out in rat and monkey. Results: Zapadcine-1 possesses a similar binding ability to the death receptor DR5 as the naked monoclonal antibody Zaptuzumab, and can be rapidly endocytosed into the lysosome of cancer cells. Zapadcine-1 specifically kills human lymphocyte leukemia cells and solid tumor cells, but not normal cells tested. More importantly, Zapadcine-1 drastically eliminates the xenografts in both CDX and PDX models of human acute leukemia. The excellent and comparable therapeutic efficacy is also observed in lung cancer NCI-H1975 CDX mouse model. The maximum-tolerated dose (MTD) of single injected Zapadcine-1 in rat and cynomolgus monkey shows an acceptable safety profile. Conclusion: These data demonstrate a promising anti-cancer activity, meriting further exploration of its potential as a novel cancer therapeutic agent, especially for the acute lymphocyte leukemia.

… CLL cells to some preparations of TRAIL. Second, they show that agonistic anti-DR4 antibody also induces apoptosis in CLL cells … acid, whereas agonistic anti-DR5 antibody does not, …

Despite progress in the treatment of acute myelogenous leukaemia (AML) the outcome often remains poor. Tumour necrosis factor related apoptosis‐inducing ligand (TRAIL) is a promising therapeutic agent in many different types of tumours, but AML cells are relatively insensitive to TRAIL‐induced apoptosis. Here we show that TRAIL‐induced apoptosis in AML cells is predominantly mediated by death receptor 4 (DR4) and not DR5. Therefore, we constructed a variant of TRAIL (rhTRAIL‐C3) that is a strong inducer of DR4‐mediated apoptosis. TRAIL‐C3 demonstrated much stronger pro‐apoptotic activity than wild‐type (WT) TRAIL in a panel of AML cell lines as well as in primary AML blasts. The higher pro‐apoptotic potential was further enhanced when the TRAIL mutant was used in combination with BMS‐345541, a selective inhibitor of inhibitor‐κB kinases. It illustrates that combination of this TRAIL variant with chemotherapeutics or other targeted agents can kill AML with high efficacy. This may represent a major advantage over the currently used therapies that have serious toxic side effects. The high efficacy of rhTRAIL‐C3 containing therapies may enable the use of lower drug doses to reduce the toxic side effects and improve patient outcome. Our findings suggest that the rational design of TRAIL variants that target DR4 potentiate the death‐inducing activity of TRAIL and offer a novel therapeutic strategy for the treatment of AML.

The present study was designed to explore the effects of low-toxicity Embelin on TRAIL-induced apoptosis and its possible mechanism in human leukemia cells. Our study showed that low-toxicity Embelin enhanced TRAIL-induced apoptosis through DR4 and DR5 upregulation and caspase activation in HL-60 cells. Pan-caspase inhibitor Z-VAD-FMK inhibited cell apoptosis induced by TRAIL alone or combined with low-toxicity Embelin, which indicated the cytotoxic effect is mediated by caspase-dependent apoptosis. Although Embelin is an X chromosome-linked inhibitor-of-apoptosis protein (XIAP) inhibitor, an XIAP independent effect on cell death was detected in HL-60 cells exposed to low-toxicity Embelin and TRAIL. Low-toxicity Embelin upregulated DR4 and DR5 expression to enhance TRAIL-induced apoptosis. The sensitizing effects of Embelin on TRAIL-induced apoptosis were markedly attenuated when DR4/DR5 was knocked down. These data suggested that low-toxicity Embelin enhanced TRAIL-induced cell apoptosis through DR4 and DR5 upregulation, indicating that combination of low-toxicity Embelin and TRAIL may become as a potential antileukemia strategy.

The tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) induces cancer cell death with minimal damage to normal cells; however, some cancer cells are resistant to TRAIL. TRAIL resistance may be overcome by agonistic antibodies to TRAIL receptors. In this study, we report the toxic effects of a novel recombinant agonistic human anti–TRAIL receptor 1 (DR4) monoclonal antibody Fab fragment, DR4-4, on various TRAIL-resistant and -sensitive cancer cell lines. The mechanisms of DR4-4 Fab–induced cell death in a human T cell leukemia cell line (Jurkat) were investigated using cell viability testing, immunoblotting, immunoassays, flow cytometry, and morphological observation. DR4-4 Fab–induced caspase-independent necrosis was observed to occur in Jurkat cells in association with p38 mitogen-activated protein kinase activation, cellular FLICE (FADD-like IL-1β-converting enzyme)-inhibitory protein degradation, decreased mitochondrial membrane potential, and increased mitochondrial reactive oxygen species production. Increased cytotoxic effects of DR4-4 Fab were observed in combination with TRAIL or γ-irradiation. Our results indicate that the novel DR4-4 Fab might overcome TRAIL-resistance and induce death in leukemia cells via cellular mechanisms different from those activated by TRAIL. DR4-4 Fab may have application as a potential therapeutic antibody fragment in single or combination therapy for cancer.

… of the expression of DR4 and DR5 on the degree of differentiation of leukemic cells, we evaluated the possibility of increasing the TRAIL sensitivity of leukemic cells by stimulating the …

… a greater contribution of DR5 than DR4 to apoptosis induction … DR4 and DR5 agonists are under clinical development our results underscore the importance of DR5 in myeloid leukemia …

… In the present study, a novel murine agonistic mAb, designated … of human DR5. This antibody can specifically bind to human … -6, a novel agonistic mAb against human DR5, has been …

… chronic lymphocytic leukemia, the constitutive embedding of DR4 in … DR4 and DR5 agonist antibodies Besides, we evaluated pro-apoptotic effects of agonist antibodies to DR4 and DR5 …

… DR4 leading to apoptosis in CLL-like cell line I-83, and DR4 … combined with chemotherapy in I-83 and primary CLL cells. … We determined whether DR4 and DR5 are localized in lipid …

… Other works, however, have shown that these agents synergistically cooperate with TRAIL or anti-DR4/DR5 agonistic mAbs in other leukemia and lymphoma lines. Doxorubicin, a DNA …

Death receptors of the TNF family are found on the surface of most cancer cells and their activation typically kills cancer cells through the stimulation of the extrinsic apoptotic pathway. The endogenous ligand for death receptors 4 and 5 (DR4 and DR5) is TNF-related apoptosis-inducing ligand, TRAIL (Apo2L). As most untransformed cells are not susceptible to TRAIL-induced apoptosis, death receptor activators have emerged as promising cancer therapeutic agents. One strategy to stimulate death receptors in cancer patients is to use soluble human recombinant TRAIL protein, but this agent has limitations of a short half-life and decoy receptor sequestration. Another strategy that attempted to evade decoy receptor sequestration and to provide improved pharmacokinetic properties was to generate DR4 or DR5 agonist antibodies. The resulting monoclonal agonist antibodies overcame the limitations of short half-life and avoided decoy receptor sequestration, but are limited by activating only one of the two death receptors. Here, we describe a DR4 and DR5 dual agonist produced using Surrobody technology that activates both DR4 and DR5 to induce apoptotic death of cancer cells in vitro and in vivo and also avoids decoy receptor sequestration. This fully human anti-DR4/DR5 Surrobody displays superior potency to DR4- and DR5-specific antibodies, even when combined with TRAIL-sensitizing proapoptotic agents. Moreover, cancer cells were less likely to acquire resistance to Surrobody than either anti-DR4 or anti-DR5 monospecific antibodies. Taken together, Surrobody shows promising preclinical proapoptotic activity against cancer cells, meriting further exploration of its potential as a novel cancer therapeutic agent. Mol Cancer Ther; 15(1); 114–24. ©2015 AACR.

Background Death Receptor 5 (DR5) is expressed on the surface of primary bone and soft tissue sarcoma cells, and its activation induces cell death primarily through apoptosis. The combination of DR5 agonists and commonly used chemotherapeutic agents, such as doxorubicin, can promote cell death. Currently, clinical trials are investigating the effectiveness of DR5 activation using new biological agents, such as bi-specific or tetravalent antibodies, in improving the survival of patients with relapsed or refractory cancers. Furthermore, investigations continue into the use of novel combination therapies to enhance DR5 response, for example, with inhibitor of apoptosis protein (IAP) antagonist agents [such as the second mitochondria-derived activator of caspase (SMAC) mimetics] and with immune checkpoint inhibitor anti-programmed death-ligand 1 (anti-PD-L1) or anti-programmed cell death-1 (anti-PD-1) antibodies. Other therapies include nanoparticle-mediated delivery of TRAIL plasmid DNA or TRAIL mRNA and stem cells as a vehicle for the targeted delivery of anti-cancer agents, such as TRAIL, to the tumor. Methods Scoping review of the literature from November 2017 to March 2024, utilizing PubMed and Google Scholar. Results New agents under investigation include nanoTRAIL, anti-Kv10.1, multimeric IgM, and humanized tetravalent antibodies. Developments have been made to test novel agents, and imaging has been used to detect DR5 in preclinical models and patients. The models include 3D spheroids, genetically modified mouse models, a novel jaw osteosarcoma model, and patient-derived xenograft (PDX) animal models. There are currently two ongoing clinical trials focusing on the activation of DR5, namely, IGM-8444 and INBRX-109, which have progressed to phase 2. Further modifications of TRAIL delivery with fusion to single-chain variable fragments (scFv-TRAIL), directed against tumor-associated antigens (TAAs), and in the use of stem cells focus on targeted TRAIL delivery to cancer cells using bi-functional strategies. Conclusion In vitro, in vivo, and clinical trials, as well as advances in imaging and theranostics, indicate that targeting DR5 remains a valid strategy in the treatment of some relapsed and refractory cancers.

TRA-8, a monoclonal antibody to death receptor 5 induces apoptosis in various cancer cells; however, the degree of sensitivity varies from highly sensitive to resistant. We have previously shown that resistance to TRA-8 can be reversed by using chemotherapeutic agents, but the mechanism underlying this sensitization was not fully understood. Here, we examined the combination of TRA-8 with doxorubicin or bortezomib in breast cancer cells. In TRA-8–resistant BT-474 and T47D cells, both chemotherapy agents synergistically sensitized cells to TRA-8 cytotoxicity with enhanced activation of apoptosis shown by cleavage of caspases and PARP, reduced Bid, increased proapoptotic Bcl-2 proteins, and increased mitochondrial membrane depolarization. Doxorubicin or bortezomib combined with TRA-8 also reduced Bcl-XL and X-linked inhibitors of apoptosis (XIAP) in treated cells. Furthermore, targeting these proteins with pharmacologic modulators, AT-101, BH3I-2′ and AT-406, produced sensitization to TRA-8. TRA-8 combined with AT-101 or BH3I-2′, inhibitors of antiapoptotic Bcl-2 proteins, produced synergistic cytotoxicity against ZR-75-1, BT-474, and T47D cells. The IAP-targeting compound, AT-406, was synergistic with TRA-8 in BT-474 cells, and to a lesser extent T47D cells. Activation of the intrinsic apoptotic pathway was a common mechanism associated with sensitization of TRA-8–resistant breast cancer cell lines. Collectively, these studies show that the Bcl-2 and IAP families of proteins are involved in TRA-8 and chemotherapy resistance via their modulation of the intrinsic apoptotic pathway. Targeting these proteins with novel agents sensitized TRA-8–resistant breast cancer cells, suggesting this approach may represent a potent therapeutic strategy in the treatment of breast cancer. Mol Cancer Res; 9(4); 403–17. ©2011 AACR.

… of various agonists to TRAIL death receptors DR4 and DR5, … These agonists demonstrated significant antitumor activity in … of DR4 mediated apoptosis was observed mainly in leukemia…

… on leukemia cells by soluble cytotoxic ligands or agonistic antibodies to … of DR4 and DR5, we found gene silencing by methylation and low basal transcription activity of DR4 and DR5 …

… ligand (TRAIL) (ie, DR4 and DR5) selectively kills cancer cells via … TRAIL and agonistic antibodies to DR4 or DR5 have … DR5 expression in glioma cells,60 human acute leukemia …

… , are standard antitumor agents for CLL and we have shown that both these agents increase DR4 and DR5 mRNA and protein expressions in primary CLL cells, but not in normal B cells…

Tumor necrosis factor-associated ligand inducing apoptosis (TRAIL) induces apoptosis through the death receptors (DRs) 4 and 5 expressed on the cell surface. Upon ligand stimulation, death receptors are rapidly internalized through clathrin-dependent and -independent mechanisms. However, there have been conflicting data on the role of death receptor endocytosis in apoptotic TRAIL signaling and possible cell type-specific differences in TRAIL signaling have been proposed. Here we have compared the kinetics of TRAIL-mediated internalization and subsequent recycling of DR4 and DR5 in resistant (HT-29 and A549) and sensitive (HCT116 and Jurkat) tumor cell lines of various origin. TRAIL stimulated the internalization of both receptors in a concentration-dependent manner with similar kinetics in sensitive and resistant cell lines without affecting the steady-state expression of DR4 and DR5 in cell lysates. Using the receptor-selective TRAIL variant DR5-B, we have shown that DR5 is internalized independently of DR4 receptor. After internalization and elimination of TRAIL from culture medium, the receptors slowly return to the plasma membrane. Within 4 h in resistant or 6 h in sensitive cells, the surface expression of receptors was completely restored. Recovery of receptors occurred both from newly synthesized molecules or from trans-Golgi network, as cycloheximide and brefeldin A inhibited this process. These agents also suppressed the expression of cell surface receptors in a time- and concentration-dependent manner, indicating that DRs undergo constitutive endocytosis. Inhibition of receptor endocytosis by sucrose led to sensitization of resistant cells to TRAIL and to an increase in its cytotoxic activity against sensitive cells. Our results confirm the universal nature of TRAIL-induced death receptor endocytosis, thus cell sensitivity to TRAIL can be associated with post-endocytic events.

… Based on these findings, soluble recombinant TRAIL and agonistic antibodies to DR4 or DR5 have progressed to phase I and phase II clinical trials as new therapeutic modalities …

Simple Summary All-trans retinoic acid (ATRA) is an established differentiation therapy for acute promyelocytic leukemia (APL), but its effect in other acute myeloid leukemia (AML) subtypes is limited. This single-author review summarizes current evidence on combination strategies designed to enhance ATRA-induced myeloid differentiation. A PubMed search using the keywords “ATRA,” “myeloid,” and “differentiation inducer or enhancer” identified over 500 published studies as of November 2025. Clinical trials demonstrate that ATRA with arsenic trioxide or epigenetic modulators induces high remission rates in APL and select AML subtypes. Pre-clinical studies reveal synergistic differentiation when ATRA is combined with Cyclin-Dependent Kinase (CDK) and kinase inhibitors, nucleotide synthesis inhibitors, DNA-damaging drugs, B-cell lymphoma 2 (Bcl-2)/Mouse double minute 2 homolog (MDM2) inhibitors, proteasome inhibitors, cytokines, glycosylation modifiers, or natural and antibiotic-derived compounds. Mechanisms include modulation of signaling pathways, chromatin remodeling, RARα stabilization, and interference with nucleotide metabolism. These findings support further clinical investigation of ATRA-based combination therapies beyond APL.

The nuclear receptor (NR) superfamily has been studied extensively in many solid tumors and some receptors have been targeted to develop therapies. However, their roles in leukemia are less clear and vary considerably among different types of leukemia. Some NRs participate in mediating the differentiation of myeloid cells, making them attractive therapeutic targets for myeloid leukemia. To date, the success of all-trans retinoic acid (ATRA) in treating acute promyelocytic leukemia (APL) remains a classical and unsurpassable example of cancer differentiation therapy. ATRA targets retinoic acid receptor (RAR) and forces differentiation and/or apoptosis of leukemic cells. In addition, ligands/agonists of vitamin D receptor (VDR) and peroxisome proliferator-activated receptor (PPAR) have also been shown to inhibit proliferation, induce differentiation, and promote apoptosis of leukemic cells. Encouragingly, combining different NR agonists or the addition of NR agonists to chemotherapies have shown some synergistic anti-leukemic effects. This review will summarize recent research findings and discuss the therapeutic potential of selected NRs in acute and chronic myeloid leukemia, focusing on RAR, VDR, PPAR, and retinoid X receptor (RXR). We believe that more mechanistic studies in this field will not only shed new lights on the roles of NRs in leukemia, but also further expand the clinical applications of existing therapeutic agents targeting NRs.

We review the importance of monocytic differentiation and differentiation induction in non-APL (acute promyelocytic leukemia) variants of acute myeloid leukemia (AML), a malignancy characterized by proliferation of immature myeloid cells. Even though the cellular differentiation block is a fundamental characteristic, the AML cells can show limited signs of differentiation. According to the French–American–British (FAB-M4/M5 subset) and the World Health Organization (WHO) 2016 classifications, monocytic differentiation is characterized by morphological signs and the expression of specific molecular markers involved in cellular communication and adhesion. Furthermore, monocytic FAB-M4/M5 patients are heterogeneous with regards to cytogenetic and molecular genetic abnormalities, and monocytic differentiation does not have any major prognostic impact for these patients when receiving conventional intensive cytotoxic therapy. In contrast, FAB-M4/M5 patients have decreased susceptibility to the Bcl-2 inhibitor venetoclax, and this seems to be due to common molecular characteristics involving mitochondrial regulation of the cellular metabolism and survival, including decreased dependency on Bcl-2 compared to other AML patients. Thus, the susceptibility to Bcl-2 inhibition does not only depend on general resistance/susceptibility mechanisms known from conventional AML therapy but also specific mechanisms involving the molecular target itself or the molecular context of the target. AML cell differentiation status is also associated with susceptibility to other targeted therapies (e.g., CDK2/4/6 and bromodomain inhibition), and differentiation induction seems to be a part of the antileukemic effect for several targeted anti-AML therapies. Differentiation-associated molecular mechanisms may thus become important in the future implementation of targeted therapies in human AML.

Paediatric acute myeloid leukaemia (AML) continues to present treatment challenges, as no “standard approach” exists to treat those young patients reliably and safely. Combination therapies could become a viable treatment option for treating young patients with AML, allowing multiple pathways to be targeted. Our in silico analysis of AML patients highlighted “cell death and survival” as an aberrant, potentially targetable pathway in paediatric AML patients. Therefore, we aimed to identify novel combination therapies to target apoptosis. Our apoptotic drug screening resulted in the identification of one potential “novel” drug pairing, comprising the Bcl-2 inhibitor ABT-737 combined with the CDK inhibitor Purvalanol-A, as well as one triple combination of ABT-737 + AKT inhibitor + SU9516, which showed significant synergism in a series of paediatric AML cell lines. Using a phosphoproteomic approach to understand the apoptotic mechanism involved, proteins related to apoptotic cell death and cell survival were represented, in agreement with further results showing differentially expressed apoptotic proteins and their phosphorylated forms among combination treatments compared to single-agent treated cells such upregulation of BAX and its phosphorylated form (Thr167), dephosphorylation of BAD (Ser 112), and downregulation of MCL-1 and its phosphorylated form (Ser159/Thr 163). Total levels of Bcl-2 were decreased but correlated with increased levels of phosphorylated Bcl-2, which was consistent with our phosphoproteomic analysis predictions. Bcl-2 phosphorylation was regulated by extracellular-signal-regulated kinase (ERK) but not PP2A phosphatase. Although the mechanism linking to Bcl-2 phosphorylation remains to be determined, our findings provide first-hand insights on potential novel combination treatments for AML.

… of leukemia cells and establish an effective anti-leukemia … leukemia cells in patients with acute myelogenous leukemia (… leukemia-derived dendritic cells, we investigated leukemia …

Differentiation therapy of acute promyelocytic leukemia with all-trans retinoic acid represents the most successful pharmacological therapy of acute myeloid leukemia (AML). Numerous studies demonstrate that drugs that inhibit mechanistic target of rapamycin (mTOR) and activate AMP-kinase (AMPK) have beneficial effects in promoting differentiation and blocking proliferation of AML. Most of these drugs are already in use for other purposes; rapalogs as immunosuppressants, biguanides as oral antidiabetics, and 5-amino-4-imidazolecarboxamide ribonucleoside (AICAr, acadesine) as an exercise mimetic. Although most of these pharmacological modulators have been widely used for decades, their mechanism of action is only partially understood. In this review, we summarize the role of AMPK and mTOR in hematological malignancies and discuss the possible role of pharmacological modulators in proliferation and differentiation of leukemia cells.

BackgroundThe increasing genomic complexity of acute myeloid leukemia (AML), the most common form of acute leukemia, poses a major challenge to its therapy. To identify potent therapeutic targets with the ability to block multiple cancer-driving pathways is thus imperative. The unique peptidyl-prolyl cis-trans isomerase Pin1 has been reported to promote tumorigenesis through upregulation of numerous cancer-driving pathways. Although Pin1 is a key drug target for treating acute promyelocytic leukemia (APL) caused by a fusion oncogene, much less is known about the role of Pin1 in other heterogeneous leukemia.MethodsThe mRNA and protein levels of Pin1 were detected in samples from de novo leukemia patients and healthy controls using real-time quantitative RT-PCR (qRT-PCR) and western blot. The establishment of the lentiviral stable-expressed short hairpin RNA (shRNA) system and the tetracycline-inducible shRNA system for targeting Pin1 were used to analyze the biological function of Pin1 in AML cells. The expression of cancer-related Pin1 downstream oncoproteins in shPin1 (Pin1 knockdown) and Pin1 inhibitor all-trans retinoic acid (ATRA) treated leukemia cells were examined by western blot, followed by evaluating the effects of genetic and chemical inhibition of Pin1 in leukemia cells on transformed phenotype, including cell proliferation and colony formation ability, using trypan blue, cell counting assay, and colony formation assay in vitro, as well as the tumorigenesis ability using in vivo xenograft mouse models.ResultsFirst, we found that the expression of Pin1 mRNA and protein was significantly increased in both de novo leukemia clinical samples and multiple leukemia cell lines, compared with healthy controls. Furthermore, genetic or chemical inhibition of Pin1 in human multiple leukemia cell lines potently inhibited multiple Pin1 substrate oncoproteins and effectively suppressed leukemia cell proliferation and colony formation ability in cell culture models in vitro. Moreover, tetracycline-inducible Pin1 knockdown and slow-releasing ATRA potently inhibited tumorigenicity of U937 and HL-60 leukemia cells in xenograft mouse models.ConclusionsWe demonstrate that Pin1 is highly overexpressed in human AML and is a promising therapeutic target to block multiple cancer-driving pathways in AML.

… of M7 megakaryoblastic leukemia. Consistently, we also observed the absence of CD123 in a single M7 … Psoriasis triggered by toll-like receptor 7 agonist imiquimod in the presence of …

Aldo–keto reductase 1C3 (AKR1C3) catalyzes the synthesis of 9α,11β-prostaglandin (PG) F2α and PGF2α prostanoids that sustain the growth of myeloid precursors in the bone marrow. The enzyme is overexpressed in acute myeloid leukemia (AML) and T-cell acute lymphoblastic leukemia (T-ALL). Moreover, AKR1C3 confers chemother-apeutic resistance to the anthracyclines: first-line agents for the treatment of leukemias. The highly homologous isoforms AKR1C1 and AKR1C2 inactivate 5α-dihydrotestosterone, and their inhibition would be undesirable. We report herein the identification of AKR1C3 inhibitors that demonstrate exquisite isoform selectivity for AKR1C3 over the other closely related isoforms to the order of >2800-fold. Biological evaluation of our isoform-selective inhibitors revealed a high degree of synergistic drug action in combination with the clinical leukemia therapeutics daunorubicin and cytarabine in in vitro cellular models of AML and primary patient-derived T-ALL cells. Our developed compounds exhibited >100-fold dose reduction index that results in complete resensitization of a daunorubicin-resistant AML cell line to the chemotherapeutic and >100-fold dose reduction of cytarabine in both AML cell lines and primary T-ALL cells.

Cr release and lactate dehydrogenase release assays. We also found that the combination of IFNγ and activation of FcγR led to the release of granzyme B by AML cells. Finally, using a murine NSG model of subcutaneous AML, we found that treatment with IFNγ plus daratumumab significantly attenuated tumor growth. Taken together, these studies show a novel mechanism of daratumumab-mediated killing and a possible new therapeutic strategy for AML.

To understand mechanisms of response to BET inhibitors (BETi), we mined the Beat AML functional genomic dataset and performed genome-wide CRISPR screens on BETi- sensitive and BETi- resistant AML cells. Both strategies revealed regulators of monocytic differentiation, SPI1, JUNB, FOS, and aryl-hydrocarbon receptor signaling (AHR/ARNT), as determinants of BETi response. AHR activation synergized with BETi while inhibition antagonized BETi-mediated cytotoxicity. Consistent with BETi sensitivity dependence on monocytic differentiation, ex vivo sensitivity to BETi in primary AML patient samples correlated with higher expression of monocytic markers CSF1R, LILRs, and VCAN. In addition, HL-60 cell line differentiation enhanced its sensitivity to BETi. Further, screens to rescue BETi sensitivity identified BCL2 and CDK6 as druggable vulnerabilities. Finally, monocytic AML patient samples refractory to venetoclax ex vivo were significantly more sensitive to combined BETi + venetoclax. Together, our work highlights mechanisms that could predict BETi response and identifies combination strategies to overcome resistance.

… within the M7 group (20, 21). Taken together, these observations suggest that AML-M7 is a … The 5-HT1A receptor agonist BAY x 3702 prevents staurosporineinduced apoptosis. Eur J …

… to the death receptor intracellular domain (death domain), … Agonist-induced PS is calcium-dependent; apoptotic PS is … to a range of pro-megakaryocytic cytokines and growth …

Despite their profoundly different cellular composition, size, and function, megakaryocytes and platelets both depend on restraint of the intrinsic (or “mitochondrial”) apoptosis pathway by BCL-2 family prosurvival proteins for their development and viability. Activation of the pathway contributes to the clearance of megakaryocytes following platelet shedding and constrains platelet lifespan in the circulation. Important questions remain as to how apoptosis is initiated in these cells at steady state and in response to pathophysiological insults.

… apoptotic mRNAs and proteins, as summarized in Table 1 [37]. These proteins are cataloged into caspase, Bcl-2, and death receptor … Induction of apoptosis in megakaryocytic leukemia …

It is believed that megakaryocytes undergo a specialized form of apoptosis to shed platelets. Conversely, a range of pathophysiological insults, including chemotherapy, are thought to cause thrombocytopenia by inducing the apoptotic death of megakaryocytes and their progenitors. To resolve this paradox, we generated mice with hematopoietic- or megakaryocyte-specific deletions of the essential mediators of apoptosis, Bak and Bax. We found that platelet production was unperturbed. In stark contrast, deletion of the prosurvival protein Bcl-x(L) resulted in megakaryocyte apoptosis and a failure of platelet shedding. This could be rescued by deletion of Bak and Bax. We examined the effect on megakaryocytes of three agents that activate the intrinsic apoptosis pathway in other cell types: etoposide, staurosporine, and the BH3 mimetic ABT-737. All three triggered mitochondrial damage, caspase activation, and cell death. Deletion of Bak and Bax rendered megakaryocytes resistant to etoposide and ABT-737. In vivo, mice with a Bak(-/-) Bax(-/-) hematopoietic system were protected against thrombocytopenia induced by the chemotherapeutic agent carboplatin. Thus, megakaryocytes do not activate the intrinsic pathway to generate platelets; rather, the opposite is true: they must restrain it to survive and progress safely through proplatelet formation and platelet shedding.

… A possible explanation for the differences between our findings and those from Battinelli's group could be the megakaryocytic source employed in each study (immortalized vs CD34 + -…

Platelets, generated from precursor megakaryocytes (MKs), are central mediators of hemostasis and thrombosis. The process of thrombopoiesis is extremely complex, regulated by multiple factors, and related to many cellular events including apoptosis. However, the role of apoptosis in thrombopoiesis has been controversial for many years. Some researchers believe that apoptosis is an ally of thrombopoiesis and platelets production is apoptosis-dependent, while others have suggested that apoptosis is dispensable for thrombopoiesis, and is even inhibited during this process. In this review, we will focus on this conflict, discuss the relationship between megakaryocytopoiesis, thrombopoiesis and apoptosis. In addition, we also consider why such a vast number of studies draw opposite conclusions of the role of apoptosis in thrombopoiesis, and try to figure out the truth behind the mystery. This review provides more comprehensive insights into the relationship between megakaryocytopoiesis, thrombopoiesis, and apoptosis and finds some clues for the possible pathological mechanisms of platelet disorders caused by abnormal apoptosis.

… -01 and HEL megakaryocytic cell lines, inhibitory effects of NO were shown to be related to the induction of apoptosis.5, 55 Although cytostasis and ultimately apoptosis may result from …

… pathway is regulated by the Bcl-2 family of pro-survival and pro-death … to death receptors. This initiates recruitment of adaptor proteins to the death receptor intracellular domain (death …

… in complex signaling pathways, including apoptosis, immune responses, and inflammation (… of RelB, and human primary megakaryocytic cells required agonist stimulation to produce …

… apoptosis, hinder differentiation, and prevent platelet production. The origin of pathological megakaryocytic apoptosis … with the TPO receptor agonists eltrombopag and romiplostim also …

Caspase-directed apoptosis usually fragments cells, releasing nonfunctional, prothrombogenic, membrane-bound apoptotic bodies marked for rapid engulfment by macrophages. Blood platelets are functional anucleate cells generated by specialized fragmentation of their progenitors, megakaryocytes (MKs), but committed to a constitutive caspase-independent death. Constitutive formation of the proplatelet-bearing MK was recently reported to be caspase-dependent, apparently involving mitochondrial release of cytochrome c, a known pro-apoptogenic factor. We extend those studies and report that activation of caspases in MKs, either constitutively or after Fas ligation, yields platelets that are functionally responsive and evade immediate phagocytic clearance, and retain mitochondrial transmembrane potential until constitutive platelet death ensues. Furthermore, the exclusion from the platelet progeny of caspase-9 present in the progenitor accounts for failure of mitochondrial release of cytochrome c to activate caspase-3 during platelet death. Thus, progenitor cell death by apoptosis can result in birth of multiple functional anucleate daughter cells.

Necroptosis is a pro-inflammatory cell death program executed by the terminal effector, mixed lineage kinase domain-like (MLKL). Previous studies suggested a role for the necroptotic machinery in platelets, where loss of MLKL or its upstream regulator, RIPK3 kinase, impacted thrombosis and haemostasis. However, it remains unknown whether necroptosis operates within megakaryocytes, the progenitors of platelets, and whether necroptotic cell death might contribute to or diminish platelet production. Here, we demonstrate that megakaryocytes possess a functional necroptosis signalling cascade. Necroptosis activation leads to phosphorylation of MLKL, loss of viability and cell swelling. Analyses at steady state and post antibody-mediated thrombocytopenia revealed that platelet production was normal in the absence of MLKL, however, platelet activation and haemostasis were impaired with prolonged tail re-bleeding times. We conclude that MLKL plays a role in regulating platelet function and haemostasis and that necroptosis signalling in megakaryocytes is dispensable for platelet production.

… To better quantify the pro-apoptotic effect of ionomycin in megakaryocytic cells, we used the flow … These results demonstrate that ionomycin induces apoptosis in megakaryocytic cells. …

… were used as models of leukemic megakaryoblasts. NMDAR components were examined … , including in megakaryocytic disease. Well-established NMDAR modulators (agonists and …

Thrombocytopenia, a common complication of prolonged radiotherapy in cancer patients, presents significant clinical management challenges due to limitations of current therapies. In this study, we screened Ginkgolic acid (GA) and elucidated its mechanisms in regulating the differentiation of Megakaryocytes (MKs) and thrombopoiesis, as well as its therapeutic potential for thrombocytopenia. Firstly, Initial validation studies conducted in vitro using K562, Meg-01 cell lines and mouse primary MK showed that GA promoted MK differentiation, which evidenced by increased cell size, enhanced polyploidization, and upregulation of specific markers. Subsequently, validation of GA's effect on platelet production was undertaken using the radiation-induced thrombocytopenia (RIT) model mice and the RIT Tg (itga2b: eGFP) model zebrafish. GA stimulated thrombopoiesis in RIT Tg (itga2b: eGFP) zebrafish and accelerated thrombopoiesis and restored platelet function in RIT model mice. Furthermore, integrated approaches combining network pharmacology, western blotting, and immunofluorescence revealed that GA exerts these effects through IL1R1 receptor activation and subsequent modulation of the SRC/MEK/ERK signaling pathway. In summary, the present study provides novel insights into the pharmacological effects of GA. GA as a novel IL1R1 agonist, promotes MK differentiation and platelet formation via downstream pathway of SRC/MEK/ERK, suggesting that GA's potential as a therapeutic candidate for treating RIT.

Neurotrophin signaling modulates the differentiation and function of mature blood cells. The expression of neurotrophin receptors and ligands by hematopoietic and stromal cells of the bone marrow indicates that neurotrophins have the potential to regulate hematopoietic cell fate decisions. This study investigates the role of neurotrophins and Tropomyosin receptor kinases (Trk) in the development of megakaryocytes (MKs) and their progeny cells, platelets. Results indicate that primary human MKs and MK cells lines, DAMI, Meg-01 and MO7e express TrkA, the primary receptor for Nerve Growth Factor (NGF) signaling. Activation of TrkA by NGF enhances the expansion of human MK progenitors (MKPs) and, to some extent, MKs. Whereas, inhibition of TrkA receptor by K252a leads to a 50% reduction in the number of both MKPs and MKs and is associated with a 3-fold increase in the production of platelets. In order to further confirm the role of TrkA signaling in platelet production, TrkA deficient DAMI cells were generated using CRISPR-Cas9 technology. Comparative analysis of wild-type and TrkA-deficient Dami cells revealed that loss of TrkA signaling induced apoptosis of MKs and increased platelet production. Overall, these findings support a novel role for TrkA signaling in platelet production and highlight its potential as therapeutic target for Thrombocytopenia.

Hematopoiesis is the process that generates blood cells in an organism from the pluripotent stem cells. Hematopoietic stem cells are characterized by their ability to undergo self-renewal and differentiation. The self-renewing ability ensures that these pluripotent cells are not depleted from the bone marrow niche. A proper balance between cell death and cell survival is necessary to maintain a homeostatic condition, hence, apoptosis, or programmed cell death, is an essential step in hematopoiesis. Recent studies, however, have introduced a new aspect to this process, citing the significance of the apoptosis mediator, caspase, in cell development and differentiation. Extensive research has been carried out to study the possible role of caspases and other apoptosis related factors in the developmental processes. This review focuses on the various apoptotic factors involved in the development and differentiation of myeloid lineage cells: erythrocytes, megakaryocytes, and macrophages.

Background CD34+ cells, megakaryocytes (MKs), and platelets express toll-like receptors (TLRs) that enable these cells to amplify the host innate immune response. However, the role of TLR7/TLR8 activation in megakaryopoiesis has not yet been investigated. Objectives We evaluated the effect of coxsackievirus B3 (CVB3) and synthetic TLR7/TLR8 agonists on the development of human MKs and production of platelets. Methods CD34+ cells from human umbilical cord were inoculated with CVB3 or stimulated with synthetic TLR7/TLR8 agonists and then cultured in the presence of thrombopoietin. Results CD34+ cells, MK progenitor cells, and mature MKs expressed TLR7 and TLR8, and exposure to CVB3 resulted in productive infection, as determined by the presence of viral infectious particles in culture supernatants. Cell expansion, differentiation into MKs, MK maturation, and platelet biogenesis were significantly reduced in CD34+-infected cultures. The reduction in MK growth was not due to an alteration in cellular proliferation but was accompanied by an increase in cellular apoptosis and pyroptosis. Impairment of MK generation and maturation of viable cells were also associated with decreased expression of transcription factors involved in these processes. These effects were completely abrogated by TLR7 but not TLR8 antagonists and mimicked by TLR7 but not TLR8 agonists. CVB3 infection of CD34+ cells increased the immunophenotype of MKs characterized as CD148+/CD48+ or CD41+/CD53+ cells. Conclusion These data suggest a novel role of TLR7 in megakaryo/thrombopoiesis that may contribute to a better understanding of the molecular basis underlying thrombocytopenia and the immunologic role of MKs in viral infection processes.

Radiation-induced thrombocytopenia (RIT) faces a perplexing challenge in the clinical treatment of cancer patients, and current therapeutic approaches are inadequate in the clinical settings. In this research, oxymatrine, a new molecule capable of healing RIT was screened out, and the underlying regulatory mechanism associated with magakaryocyte (MK) differentiation and thrombopoiesis was demonstrated. The capacity of oxymatrine to induce MK differentiation was verified in K-562 and Meg-01 cells in vitro. The ability to induce thrombopoiesis was subsequently demonstrated in Tg (cd41:enhanced green fluorescent protein (eGFP)) zebrafish and RIT model mice. In addition, we carried out network pharmacological prediction, drug affinity responsive target stability assay (DARTS) and cellular thermal shift assay (CETSA) analyses to explore the potential targets of oxymatrine. Moreover, the pathway underlying the effects of oxymatrine was determined by Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses, Western blot (WB), and immunofluorescence. Oxymatrine markedly promoted MK differentiation and maturation in vitro. Moreover, oxymatrine induced thrombopoiesis in Tg (cd41:eGFP) zebrafish and accelerated thrombopoiesis and platelet function recovery in RIT model mice. Mechanistically, oxymatrine directly binds to toll-like receptor 2 (TLR2) and further regulates the downstream pathway stimulator of interferon genes (STING)/nuclear factor-kappaB (NF-κB), which can be blocked by C29 and C-176, which are specific inhibitors of TLR2 and STING, respectively. Taken together, we demonstrated that oxymatrine, a novel TLR2 agonist, plays a critical role in accelerating MK differentiation and thrombopoiesis via the STING/NF-κB axis, suggesting that oxymatrine is a promising candidate for RIT therapy.