Lipid-polymer hybrid nanoparticle with cell-distinct drug release for treatment of stemness-derived resistant tumor

Drug resistance presents one of the major causes for the failure of cancer chemotherapy.Cancer stem-like cells(CSCs),a population of self-renewal cells with high tumorigenicity and innate chemoresistance,can survive conventional chemotherapy and generate increased resistance.Here,we develop a lipid-polymer hybrid nanoparticle for co-delivery and cell-distinct release of the differentiation-inducing agent,all-trans retinoic acid and the chemotherapeutic drug,doxorubicin to overcome the CSC-associated chemoresistance.The hybrid nanoparticles achieve differential release of the combined drugs in the CSCs and bulk tumor cells by responding to their specific intracellular signal variation.In the hypoxic CSCs,ATRA is released to induce differentiation of the CSCs,and in the differentiating CSCs with decreased chemoresistance,DOX is released upon elevation of reactive oxygen species to cause subsequent cell death.In the bulk tumor cells,the drugs are released synchronously upon the hypoxic and oxidative conditions to exert potent anticancer effect.This cell-distinct drug release enhances the synergistic therapeutic efficacy of ATRA and DOX with different anticancer mechanism.We show that treatment with the hybrid nanoparticle efficiently inhibit the tumor growth and metastasis of the CSC-enriched triple negative breast cancer in the mouse models.

Self-assembly of polysarcosine amphiphilic polymers-tethered gold nanoparticles for precise photo-controlled synergistic therapy

Polymer-induced self-assembly of inorganic nanoparticles has emerged as a powerful strategy for fabrication of stimuliresponsive drug delivery nanosystems.Herein,we designed and synthesized a series of lipoic acid-capped polysarcosine-bpolycaprolactone(PSar-b-PCL)block copolymers.The self-assembly of gold nanoparticles drove by these block copolymers was systematically investigated,and the preparation of near-infrared(NIR)light-responsive PSar-decorated gold nanovesicle(PSGV)was optimized.DOX as anticancer drug was efficiently encapsulated within the cavity of PSGV.The PSGV greatly prevented doxorubicin(DOX)from premature leakage.While upon 808 nm laser irradiation,most of loaded DOX was rapidly released,along with the recovery of DOX fluorescence.Impressively,the DOX-loaded PSGV(DOX-PSGV)exhibited much higher cell uptake efficiency when compared to DOX-loaded polyethylene glycol(PEG)-coated gold nanovesicle(DOX-PEGV).Thanks to the synergistic photothermal/chemo therapy,the DOX-PSGV had highly superior antitumor efficacy in established 4T1 tumor model.

Identification of a new azoreductase driven prodrug from bardoxolone methyl and 5-aminosalicylate for the treatment of colitis in mice

For local treatment of ulcerative colitis,a new azoreductase driven prodrug CDDO-AZO from bardoxolone methyl(CDDO-Me)and 5-aminosalicylate(5-ASA)was designed,synthesized and biologically evaluated.It is proposed that orally administrated CDDO-AZO is stable before reaching the colon,while it can also be triggered by the presence of azoreductase in the colon to fragment into CDDO-Me and 5-ASA,generating potent anti-colitis effects.Superior to olsalazine(OLS,a clinically used drug for ulcerative colitis)and CDDO-Me plus 5-ASA,CDDO-AZO significantly attenuated inflammatory colitis symptoms in DSS-induced chronic colitis mice,which suggested that CDDO-AZO may be a promising anti-ulcerative colitis agent.

Cell-based drug delivery systems for biomedical applications

Spurred by numerous achievements in nanoscience and nanotechnology, the evolution of nanoparticulate drug delivery systems （nano-DDSs） is in its rapid growth period and attracting considerable attention due to their unique advantages in biomedical applications. Natural particulates ranging from mammalian cells to bacteria possess their own distinctive delivery processes and mechanisms, which inspires more design and development of cell-based DDSs by integrating the innate functions of cells with the nanoscale characteristics of nanoparticles. In this review article, we focus on the recent advances in cell-based DDSs for site-specific delivery of therapeutics and enhanced treatment of diseases. The promise and perils of cell-based DDSs are also discussed.

New techniques and strategies in drug discovery

Great success has been witnessed in last decades,some new techniques and strategies have been widely used in drug discovery.In this roadmap,several representative techniques and strategies are highlighted to show recent advances in this filed.(A)A DOX protocol has been developed for accurate protein-ligand binding structure prediction,in which first principle method was used to rank the binding poses.Validation against crystal structures have found that DOX prediction achieved an impressive success rate of 99%,indicating significant improvement over molecular docking method.(B)Virtual target profiling is a compound-centric strategy enabling a parallel implementation of interrogating compounds against various targets in a single screen,which has been used in hit/lead identification,drug repositioning,and mechanism-of-action studies.Current and emerging methods for virtual target profiling are briefly summarized herein.(C)Research on targeted autophagy to treat diseases has received encouraging progress.However,due to the complexity of autophagy and disease,experimental and in silico methods should be performed synergistically for the entire process.This part focuses on in silico methods in autophagy research to promote their use in medicinal research.(D)Histone deacetylases(HDACs)play important roles in various biological functions through the deacetylation of lysine residues.Recent studies demonstrated that HDACs,which possess low deacetylase activities,exhibited more efficient defatty-acylase activities.Here,we review the defatty-acylase activity of HDACs and describe examples for the design of isoform selective HDAC inhibitor.(E)The FDA approval of three kinase allosteric inhibitors and some others entering clinical study has spurred considerable interests in this targeted drug discovery area.(F)Recent advances are reviewed in structure-based design of novel antiviral agents to combat drug resistance.(G)Since nitric oxide(NO)exerts anticancer activity depending on its concentration,optimal levels of NO in cancer cells is desirable.In this minireview,we briefly describe recent advances in the research of NO-based anticancer agents by our group and present some opinions on the future development of these agents.(H)The field of photoactivation strategies have been extensively developed for controlling chemical and biological processes with light.This review will summarize and provide insight into recent research advances in the understanding of photoactivatable molecules including photoactivatable caged prodrugs and photoswitchable molecules.

Synthesis and evaluation of 2-cyano-3, 12-dioxooleana-1, 9(11)-en-28-oate-13β, 28-olide as a potent anti-inflammatory agent for intervention of LPS-induced acute lung injury

The present study was designed to synthesize 2-Cyano-3, 12-dioxooleana-1, 9(11)-en-28-oate-13β, 28-olide(1), a lactone derivative of oleanolic acid(OA) and evaluate its anti-inflammatory activity. Compound 1 significantly diminished nitric oxide(NO) production and down-regulated the m RNA expression of iNOS, COX-2, IL-6, IL-1β, and TNF-α in lipopolysaccharide(LPS)-stimulated RAW264.7 cells. Further in vivo studies in murine model of LPS-induced acute lung injury(ALI) showed that 1 possessed more potent protective effects than the well-known anti-inflammatory drug dexamethasone by inhibiting myeloperoxidase(MPO) activity, reducing total cells and neutrophils, and suppressing inflammatory cytokines expression, and thus ameliorating the histopathological conditions of the injured lung tissue. In conclusion, compound 1 could be developed as a promising anti-inflammatory agent for intervention of LPS-induced ALI.

Histology and antitumor activity study of PTX-loaded micelle,a fluorescent drug delivery system prepared by PEG-TPP

We synthesized PEG-TPP as carrier to encapsulate paclitaxel (PTX) in the form of micelles to overcome its water-solubility problem. PTX-loaded micelles possess a-week stability and appropriate particle size (152.1 ±1.2 nm) which is beneficial for enhanced permeability and retention (EPR) effect. Strong pH dependence of PTX releasing from micelles is verified by in vitro release study. At cellular level, PTX-loaded micelles can target mitochondria effectively which may results a better cytotoxicity of micelles (especially IC50 = 0.123 ± 0.035μmol/L of micelles and 0.298 ± 0.067μmol/L of PTX alone on MCF-7 cells). The fluorescence distributions of both isolated and sliced organs show that the micelles can effectively target tumors. Moreover, we further prove the enhanced therapeutic effects of micelles in tumor-bearing mice comparing with PTX alone. The results show that the biodegradable drug delivery system prepared by PEG-TPP can overcome the poor solubility of paclitaxel and improve its tumor targeting and antitumor activity.

Amphiphilic Dendrimer Vectors for RNA Delivery:State-of-the-Art and Future

Dendrimers,a special family of polymers,are particularly promising materials for various biomedical applications by virtue of their well-defined dendritic structure and cooperative multivalency.Specifically,in this Account,we present state-of-the-art amphiphilic dendrimers for nucleic acid delivery.Ribonucleic acid(RNA)molecules are fast becoming an important drug modality,particularly since the recent success of mRNA vaccines against COVID-19.Notably,RNA therapeutics offer the unique opportunity to treat diseases at the gene level and address“undruggable”targets.However,RNA therapeutics are not stable and have poor bioavailability,imposing the need for their protection and safe delivery by vectors to the sites-of-action to allow the desired therapeutic effects.Currently,the two most advanced nonviral vectors are based on lipids and polymers,with lipid vectors primarily exploiting the membrane-fusion mechanism and polymer vectors mainly endocytosis-mediated delivery.Notably,only lipid vectors have been advanced through to their clinical use in the delivery of,for example,the first siRNA drug and the first mRNA vaccine.The success of lipid vectors for RNA delivery has motivated research for further innovative materials as delivery vectors.Specifically,we have pioneered lipid/dendrimer conjugates,referred to as amphiphilic dendrimers,for siRNA delivery with the view to harnessing the delivery advantages of both lipid and polymer vectors while enjoying the unique structural features of dendrimers.These amphiphilic dendrimer vectors are lipid/dendrimer hybrids and are thus able to mimic lipid vectors and exploit membranefusion-mediated delivery,while simultaneously retaining the multivalent properties of polymer vectors that allow endocytosis-based delivery.In addition,they have precisely controllable and stable nanosized chemical structures and offer nanotechnology-based delivery.Effective amphiphilic dendrimer vectors share two important elements:chemical hydrophilic entities to bind RNA and RNA complex-stabilizing hydrophobicity.These two combined features allow the encapsulation of RNA within a stable complex before its release into the cytosol following endocytosis.This hydrophilic/hydrophobic balance permitted by the structural features of amphiphilic dendrimers plays a determining role in RNA delivery success.In this Account,we provide a conceptual overview of this exciting field with the latest breakthroughs and key advances in the design of amphiphilic dendrimers for the delivery of siRNA and mRNA.Specifically,we start with a short introduction to siRNA-and mRNA-based therapeutics and their delivery challenges.We then outline the pioneering and representative studies on amphiphilic dendrimer vectors to highlight their historical development and promising features that offer to facilitate the once challenging RNA delivery.We conclude by offering perspectives for the future of amphiphilic dendrimer vectors for nucleic acid delivery in general.

Reprogrammed siTNFα/neutrophil cytopharmaceuticals targeting inflamed joints for rheumatoid arthritis therapy

Rheumatoid arthritis(RA)is an autoimmune disease characterized by severe synovial inflammation and cartilage damage.Despite great progress in RA therapy,there still lacks the drugs to completely cure RA patients.Herein,we propose a reprogrammed neutrophil cytopharmaceuticals loading with TNFα-targeting-siRNA(siTNFα)as an alternative anti-inflammatory approach for RA treatment.The loaded siTNFαact as not only the gene therapeutics to inhibit TNFαproduction by macrophages in inflamed synovium,but also the editors to reprogram neutrophils to anti-inflammatory phenotypes.Leveraging the active tendency of neutrophils to inflammation,the reprogrammed siTNFα/neutrophil cytopharmaceuticals(siTNFα/TP/NEs)can rapidly migrate to the inflamed synovium,transfer the loaded siTNFαto macrophages followed by the significant reduction of TNFαexpression,and circumvent the pro-inflammatory activity of neutrophils,thus leading to the alleviated synovial inflammation and improved cartilage protection.Our work provides a promising cytopharmaceutical for RA treatment,and puts forward a living neutrophil-based gene delivery platform.

Enzyme-instructed hybrid nanogel/nanofiber oligopeptide hydrogel for localized protein delivery

Enzyme-catalysis self-assembled oligopeptide hydrogel holds great interest in drug delivery,which has merits of biocompatibility,biodegradability and mild gelation conditions.However,its application for protein delivery is greatly limited by inevitable degradation of enzyme on the encapsulated proteins leading to loss of protein activity.Moreover,for the intracellularly acted proteins,cell membrane as a primary barrier hinders the transmembrane delivery of proteins.The internalized proteins also suffer from acidic and enzymatic degradation in endosomes and lysosomes.We herein develop a proteasemanipulated hybrid nanogel/nanofiber hydrogel for localized delivery of intracellularly acted proteins.The embedded polymeric nanogels(CytoC/aNGs)preserve activity of cytochrome c(CytoC)that is an intracellular activator for cell apoptosis as a model protein against proteolysis,and do not affect the gelation properties of the protease-catalysis assembled hydrogels.The injectable hydrogel(CytoC/aNGs/Gel)serves as a reservoir to enhance intratumoral retention and realize sustainable release of CytoC/aNGs.The released CytoC/aNGs increase cellular uptake of CytoC and enhance its intracellular delivery to its target site,cytoplasm,resulting in favorable apoptosis-inducing and cytotoxic effects.We show that a single local administration of CytoC/aNGs/Gel efficiently inhibit the tumor growth in the breast tumor mouse model.

Hippocampal PPARδ downregulation contri butes to depressive phenotype with decreased neurogenesis

Our previous study showed that up-regulating hippocampal peroxisome proliferator-activated receptorδ(PPARδ)displays an antidepressive effect and enhanc-es hippocampal neurogenesis in the context of chronic stress.Here,the changes in depressive behaviors and hippocampal neurogenesis were investigated after PPARδknockdown by microinfusion of the lentiviral vector,expressing short hairpin RNA(sh RNA)complementary to the coding exon of PPARδ,into the bilateral dentate gyri of the hippocampus or PPARδblockade by repeated systemic administration of PPARδantagonist,GSK0660(1 or 3mg·kg-1,ip,for 21 d).We found that hippocampal PPARδknockdown or blockade induced depressive-like behaviors and increased vulnerability to stress,which is involved in decreased hippocampal neurogenesis and neuronal differentiation.Down-regulating hippocampal PPARδalso induced significant decreases in phosphorylation c AMP response element-binding protein(CREB)and BDNF level in the hippocampus.The in vitro study that PPARδknockdown or blockade inhibited proliferation and differentiation of neural stem cells.Taken together,our results suggest that PPARδcould be a novel and promising target for developing new PPARδagonists for the treatment of depressive disorders.

Vitamin D receptor (VDR) mediates the quiescence of activated hepatic stellate cells (aHSCs) by regulating M2 macrophage exosomal smooth muscle cell-associated protein 5 (SMAP-5)

An effective therapeutic regimen for hepatic fibrosis requires a deep understanding of the pathogenesis mechanism.Hepatic fibrosis is characterized by activated hepatic stellate cells(aHSCs)with an excessive production of extracellular matrix.Although promoted activation of HSCs by M2 macrophages has been demonstrated,the molecular mechanism involved remains ambiguous.Herein,we propose that the vitamin D receptor(VDR)involved in macrophage polarization may regulate the communication between macrophages and HSCs by changing the functions of exosomes.We confirm that activating the VDR can inhibit the effect of M2 macrophages on HSC activation.The exosomes derived from M2 macrophages can promote HSC activation,while stimulating VDR alters the protein profiles and reverses their roles in M2 macrophage exosomes.Smooth muscle cell-associated protein 5(SMAP-5)was found to be the key effector protein in promoting HSC activation by regulating autophagy flux.Building on these results,we show that a combined treatment of a VDR agonist and a macrophage-targeted exosomal secretion inhibitor achieves an excellent anti-hepatic fibrosis effect.In this study,we aim to elucidate the association between VDR and macrophages in HSC activation.The results contribute to our understanding of the pathogenesis mechanism of hepatic fibrosis,and provide potential therapeutic targets for its treatment.

Identification of highly efficacious PROTACs targeting BRD4 against acute myeloid leukemia:Design,synthesis,and biological evaluations

The abnormal activation of BRD4 accelerates the progression of acute myeloid leukemia(AML),developing more precise therapeutics to intervene BRD4 promise to be an excellent opportunity to avoid current limitations of chemotherapy in clinic.Herein,a range of small-molecule PROTACs with the privileged 8-methyl-pyrrolo[1,2-a]pyrazin-1(2H)-one scaffold were rationally designed,which harbored different carbon or ethylenedioxy chains to degrade BRD4 mediated by the E3 ubiquitin ligase CRBN.Among them,the most potential B24 exhibited remarkable BRD4 degradation and excellent anti-proliferative activities in MV4-11 cells,with values of DC_(50)and IC_(50)for 0.75 nmol/L and 0.4 nmol/L,respectively,which were better than the BRD4 inhibitor(+)-JQ-1.Notably,this compound could time-dependently degrade the target protein in the BRD4-,CRBN-,and proteasome-dependent manner.Besides,B24 dramatically decreased the level of proto-oncogene c-Myc,and induced cell apoptosis by arresting the cell cycle in G0/G1 phase,down-regulating Bcl-2 and up-regulating Bax to amplify apoptotic effectors.This proof-of-concept study also highlighted the feasibility of BRD4-based PROTACs as a more powerful strategy against AML.

A novel mesenchymal stem cell-based regimen for acute myeloid leukemia differentiation therapy

Currently the main treatment of acute myeloid leukemia(AML)is chemotherapy combining hematopoietic stem cell transplantation.However,the unbearable side effect of chemotherapy and the high risk of life-threatening infections and disease relapse following hematopoietic stem cell transplantation restrict its application in clinical practice.Thus,there is an urgent need to develop alternative therapeutic tactics with significant efficacy and attenuated adverse effects.Here,we revealed that umbilical cord-derived mesenchymal stem cells(UC-MSC)efficiently induced AML cell differentiation by shuttling the neutrophil elastase(NE)-packaged extracellular vesicles(EVs)into AML cells.Interestingly,the generation and release of NE-packaged EVs could be dramatically increased by vitamin D receptor(VDR)activation in UC-MSC.Chemical activation of VDR by using its agonist 1a,25-dihydroxyvitamin D3 efficiently enhanced the pro-differentiation capacity of UC-MSC and then alleviated malignant burden in AML mouse model.Based on these discoveries,to evade the risk of hypercalcemia,we synthetized and identified sw-22,a novel non-steroidal VDR agonist,which exerted a synergistic prodifferentiation function with UC-MSC on mitigating the progress of AML.Collectively,our findings provided a non-gene editing MSC-based therapeutic regimen to overcome the differentiation blockade in AML.

Click chemistry and natural products

The 2022 Nobel Prize in Chemistry was awarded to American scientists Carolyn Bertozzi,K.Barry Sharpless,and Danish scientist Morten P.Merdahl for their contributions to the development of click chemistry and bioorthogonal chemistry.

Current developments in pharmacological therapeutics for chronic constipation

Chronic constipation is a common gastrointestinal disease severely affecting the patient's quality of life. The traditional treatment of constipation is the use of laxatives. Recently, several new drugs including lubiprostone, linaclotide and prucalopride have been approved for treatment of chronic constipation. However, a significant unmet medical need still remains, particularly among those patients achieving poor results by current therapies. The 5-HT4 receptor modulators velusetrag and naronapride,the guanylate cyclase C agonist plecanatide and the ileal bile acid transporter inhibitor elobixibat are recognized as the most promising drugs under investigation. Herein, we give a comprehensive review on the pharmacological therapeutics for the treatment of chronic constipation, with the purpose of reflecting the drug development trends in this field.

Tetrandrine inhibits migration and invasion of rheumatoid arthritis fibroblast-like synoviocytes through down-regulating the expressions of Rac1, Cdc42, and Rho A GTPases and activation of the PI3K/Akt and JNK signaling pathways

Tetrandrine(Tet), the main active constituent of Stephania tetrandra root, has been demonstrated to alleviate adjuvant-induced arthritis in rats. The present study was designed to investigate the effects of Tet on the migration and invasion of rheumatoid arthritis fibroblast-like synoviocytes(RA-FLS) and explore the underlying mechanisms. By using cultures of primary FLS isolated from synoviums of RA patients and cell line MH7 A, Tet(0.3, 1 μmol·L-1) was proven to significantly impede migration and invasion of RA-FLS, but not cell proliferation. Tet also greatly reduced the activation and expressions of matrix degrading enzymes MMP-2/9, the expression of F-actin and the activation of FAK, which controlled the morphologic changes in migration process of FLS. To identify the key signaling pathways by which Tet exerts anti-migration effect, the specific inhibitors of multiple signaling pathways LY294002, Triciribine, SP600125, U0126, SB203580, and PDTC(against PI3 K, Akt, JNK, ERK, p38 MAPK and NF-κB-p65, respectively) were used. Among them, LY294002, Triciribine, and SP600125 were shown to obviously inhibit the migration of MH7 A cells. Consistently, Tet was able to down-regulate the activation of Akt and JNK as demonstrated by Western blotting assay. Moreover, Tet could reduce the expressions of migration-related proteins Rho GTPases Rac1, Cdc42, and Rho A in MH7 A cells. In conclusion, Tet can impede the migration and invasion of RA-FLS, which provides a plausible explanation for its protective effect on RA. The underlying mechanisms involve the reduction of the expressions of Rac1, Cdc42, and Rho A, inhibition of the activation of Akt and JNK, and subsequent down-regulation of activation and/or expressions of MMP-2/9, F-actin, and FAK.

Moutan Cortex and Paeoniae Radix Rubra reverse high-fat-diet-induced metabolic disorder and restore gut microbiota homeostasis

The present study was designed to investigate the therapeutic effcts of Moutan Cortex(CM,root bark of Paeonia suffruticosa Andr) and Paeoniae Radix Rubra(PR,root of Paeonia veitchii Lynch) on metabolic disorders,focusing on the infuence of CM and PR on the obesity-related gut microbiota homeostasis.The diet-induced obese(DIO) mouse model was used to test the therapeutic effects of CM and PR.The mice were orally administered with CM and PR for 6 weeks,and oral glucose tolerance test(OGTT) and insulin tolerance test(ITT) were performed to evaluate the insulin sensitivity of the mice.Sterol-regulatory element binding proteins(SREBPs) and their target genes were measured by quantitative RT-PCR.High-throughput 16 S ribosomal RNA(16S rR NA) gene sequencing technology was used to determine the composition of gut microbiota,and the metabolites in serum were analyzed by GC-MS.Our results indicated that CM and PR combination alleviated obese and insulin resistance in the DIO mice,leading to increased glucose uptake and gene expression in muscle and liver,and down-regulated SREBPs and their target genes in liver.Interesting,neither the CM-PR extracts,nor the major components of CM and PR did not affect SREBPs activity in cultured cells.Meanwhile,CM and PR significantly modulated the gut microbiota of the high-fat diet(HFD) treated mice,similar to metformin,and CM-PR reversed the overall microbiota composition similar to the normal chow diet(NCD) treated mice.In conclusion,our results provide novel mechanisms of action for the effects of CM and PR in treating DIO-induced dysregulation of sugar and lipid metabolism.

Design, synthesis, and biological evaluation of ligustrazine/resveratrol hybrids as potential anti-ischemic stroke agents

To search for potent anti-ischemic stroke agents,a series of tetramethylpyrazine(TMP)/resveratrol(RES)hybrids 6 a-t were designed and synthesized.These hybrids inhibited adenosine diphosphate(ADP)-or arachidonic acid(AA)-induced platelet aggregation,among them,6 d,6 g-i,6 o and 6 q were more active than TMP.The most active compound 6 h exhibited more potent antiplatelet aggregation activity than TMP,RES,as well as positive control ticlopidine(Ticlid)and aspirin(ASP).Furthermore,6 h exerted strong antioxidative activity in a dose-dependent manner in rat pheochromocytoma PC12 cells which were treated with hydrogen peroxide(H2 O2)or hydroxyl radical(·OH).Importantly,6 h significantly protected primary neuronal cells suffered from oxygen-glucose deprivation/reoxygenation(OGD/R)injury,comparable to an anti-ischemic drug edaravone(Eda).Together,our findings suggest that 6 h may be a promising candidate warranting further investigation for the intervention of ischemic stroke.

Synergistic antitumor activity of artesunate and HDAC inhibitors through elevating heme synthesis via synergistic upregulation of ALAS1 expression

Artemisinin and its derivatives(ARTs) were reported to display heme-dependent antitumor activity. On the other hand, histone deacetylase inhibitors(HDACi) were known to be able to promote heme synthesis in erythroid cells. Nevertheless, the effect of HDACi on heme homeostasis in nonerythrocytes remains unknown. We envisioned that the combination of HDACi and artesunate(ARS)might have synergistic antitumor activity through modulating heme synthesis. In vitro studies revealed that combination of ARS and HDACi exerted synergistic tumor inhibition by inducing cell death. Moreover, this combination exhibited more effective antitumor activity than either ARS or HDACi monotherapy in xenograft models without apparent toxicity. Importantly, mechanistic studies revealed that HDACi coordinated with ARS to increase 5-aminolevulinate synthase(ALAS1) expression, and subsequent heme production, leading to enhanced cytotoxicity of ARS. Notably, knocking down ALAS1 significantly blunted the synergistic effect of ARS and HDACi on tumor inhibition, indicating a critical role of ALAS1 upregulation in mediating ARS cytotoxicity. Collectively, our study revealed the mechanism of synergistic antitumor action of ARS and HDACi. This finding indicates that modulation of heme synthesis pathway by the combination based on ARTs and other heme synthesis modulators represents a promising therapeutic approach to solid tumors.