Higher-Order Clustering of the Transmembrane Anchor of DR5 Drives Signaling.

Receptor clustering on the cell membrane is critical in the signaling of many immunoreceptors, and this mechanism has previously been attributed to the extracellular and/or the intracellular interactions. Here, we report an unexpected finding that for death receptor 5 (DR5), a receptor in the tumor necrosis factor receptor superfamily, the transmembrane helix (TMH) alone in the receptor directly assembles a higher-order structure to drive signaling and that this structure is inhibited by the unliganded ectodomain. Nuclear magnetic resonance structure of the TMH in bicelles shows distinct trimerization and dimerization faces, allowing formation of dimer-trimer interaction networks. Single-TMH mutations that disrupt either trimerization or dimerization abolish ligand-induced receptor activation. Surprisingly, proteolytic removal of the DR5 ectodomain can fully activate downstream signaling in the absence of ligand. Our data suggest a receptor activation mechanism in which binding of ligand or antibodies to overcome the pre-ligand autoinhibition allows TMH clustering and thus signaling.

Apoptosis. DR5 unfolds ER stress.

ER stress induces apoptosis through DR5, which is regulated by the UPR factors PERK and IRE1α.

Coordination between Two Branches of the Unfolded Protein Response Determines Apoptotic Cell Fate.

The kinases PERK and IRE1 alleviate endoplasmic reticulum (ER) stress by orchestrating the unfolded protein response (UPR). If stress mitigation fails, PERK promotes cell death by activating pro-apoptotic genes, including death receptor 5 (DR5). Conversely, IRE1-which harbors both kinase and endoribonuclease (RNase) modules-blocks apoptosis through regulated IRE1-dependent decay (RIDD) of DR5 mRNA. Under irresolvable ER stress, PERK activity persists, whereas IRE1 paradoxically attenuates, by mechanisms that remain obscure. Here, we report that PERK governs IRE1's attenuation through a phosphatase known as RPAP2 (RNA polymerase II-associated protein 2). RPAP2 reverses IRE1 phosphorylation, oligomerization, and RNase activation. This inhibits IRE1-mediated adaptive events, including activation of the cytoprotective transcription factor XBP1s, and ER-associated degradation of unfolded proteins. Furthermore, RIDD termination by RPAP2 unleashes DR5-mediated caspase activation and drives cell death. Thus, PERK attenuates IRE1 via RPAP2 to abort failed ER-stress adaptation and trigger apoptosis.

Jekyll & Hyde: The Other Life of the Death Ligand TRAIL.

Henry and Martin (2017) and Hartwig et al. (2017) provide more insights into the non-apoptotic function of the FADD/caspase-8 duo in TRAIL signaling.

Caspase-8 Acts in a Non-enzymatic Role as a Scaffold for Assembly of a Pro-inflammatory "FADDosome" Complex upon TRAIL Stimulation.

TRAIL is a potent inducer of apoptosis and has been studied almost exclusively in this context. However, TRAIL can also induce NFκB-dependent expression of multiple pro-inflammatory cytokines and chemokines. Surprisingly, whereas inhibition of caspase activity blocked TRAIL-induced apoptosis, but not cytokine production, knock down or deletion of caspase-8 suppressed both outcomes, suggesting that caspase-8 participates in TRAIL-induced inflammatory signaling in a scaffold role. Consistent with this, introduction of a catalytically inactive caspase-8 mutant into CASP-8 null cells restored TRAIL-induced cytokine production, but not cell death. Furthermore, affinity precipitation of the native TRAIL receptor complex revealed that pro-caspase-8 was required for recruitment of RIPK1, via FADD, to promote NFκB activation and pro-inflammatory cytokine production downstream. Thus, caspase-8 can serve in two distinct roles in response to TRAIL receptor engagement, as a scaffold for assembly of a Caspase-8-FADD-RIPK1 "FADDosome" complex, leading to NFκB-dependent inflammation, or as a protease that promotes apoptosis.

The TRAIL-Induced Cancer Secretome Promotes a Tumor-Supportive Immune Microenvironment via CCR2.

Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is known for specifically killing cancer cells, whereas in resistant cancers, TRAIL/TRAIL-R can promote metastasis via Rac1 and PI3K. It remains unknown, however, whether and to what extent TRAIL/TRAIL-R signaling in cancer cells can affect the immune microenvironment. Here we show that TRAIL-triggered cytokine secretion from TRAIL-resistant cancer cells is FADD dependent and identify the TRAIL-induced secretome to drive monocyte polarization to myeloid-derived suppressor cells (MDSCs) and M2-like macrophages. TRAIL-R suppression in tumor cells impaired CCL2 production and diminished both lung MDSC presence and tumor growth. In accordance, the receptor of CCL2, CCR2, is required to facilitate increased MDSC presence and tumor growth. Finally, TRAIL and CCL2 are co-regulated with MDSC/M2 markers in lung adenocarcinoma patients. Collectively, endogenous TRAIL/TRAIL-R-mediated CCL2 secretion promotes accumulation of tumor-supportive immune cells in the cancer microenvironment, thereby revealing a tumor-supportive immune-modulatory role of the TRAIL/TRAIL-R system in cancer biology.

TRAIL-driven targeting and reversing cervical cancer radioresistance by seleno-nanotherapeutics through regulating cell metabolism.

Recently, radioresistance has become a major obstacle in the radiotherapy of cervical cancer. To demonstrate enhanced radiosensitization against radioresistant cervical cancer, radioresistant cervical cancer cell line was developed and the mechanism of radioresistance was explored. Due to the overexpression of (death receptor 5, DR5) in cervical cancer, tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-overexpressed cervical cancer cell membrane-camouflaged Cu2-xSe nanomedicine (CCMT) was designed. Since the CCMT was encapsulated with TRAIL-modified cell membrane, it represented high target to cervical cancer cell and immune evasion. Furthermore, Cu2-xSe had the ability to scavenge glutathione (GSH) and produce ·OH with excess H2O2 in the tumor microenvironment. The presence of CCMT combined with radiation therapy could effectively increase the 1O2 produced by X-rays. In vitro and in vivo studies elaborated that CCMT exhibited excellent radiosensitization properties to reverse radiotolerance by scavenging GSH and promoting DNA damage, apoptosis, mitochondrial membrane potential damage and metabolic disruption. Collectively, this study suggested that the development of TRAIL-overexpressed cell membrane-camouflaged Cu2-xSe nanomedicine could advance future cervical cancer treatment and minimize the disadvantages associated with radiation treatment.

TNFRSF10A downregulation induces retinal pigment epithelium degeneration during the pathogenesis of age-related macular degeneration and central serous chorioretinopathy.

Age-related macular degeneration (AMD) and central serous chorioretinopathy (CSC) are common diseases that can cause vision loss in older and younger populations. These diseases share pathophysiological conditions derived from retinal pigment epithelium (RPE) dysfunction. Tumor necrosis factor receptor superfamily 10A (TNFRSF10A)-LOC389641 with the same lead single-nucleotide polymorphism (SNP) (rs13278062) is the only overlapped susceptibility locus found in both AMD and CSC through genome-wide association studies. This lead SNP has been reported to alter the transcriptional activity of TNFRSF10A. This study aimed to elucidate the function of TNFRSF10A in RPE degeneration using human primary RPE cells and Tnfrsf10 knockout (Tnfrsf10-/-) mice. TNFRSF10A was found to be localized in human RPE. In vitro assays revealed that a T allele of rs13278062, the risk allele for AMD and CSC, downregulated TNFRSF10A transcription in RPE, leading to decreased cell viability and increased apoptosis through protein kinase C-α (PKCA) downregulation. Treatment with phorbol 12-myristate 13-acetate, a PKC activator, rescued the cell viability. Morphological RPE abnormality was found in the retina of Tnfrsf10-/- mice. Our data suggest that downregulation of TNFRSF10A expression inactivates PKCA signaling and causes cellular vulnerability of the RPE, which may contribute to the pathogenesis of AMD and CSC.

Association of TRAIL receptor with phosphatase SHP-1 enables repressing T cell receptor signaling and T cell activation through inactivating Lck.

BACKGROUND: T cell receptor (TCR) signaling and T cell activation are tightly regulated by gatekeepers to maintain immune tolerance and avoid autoimmunity. The TRAIL receptor (TRAIL-R) is a TNF-family death receptor that transduces apoptotic signals to induce cell death. Recent studies have indicated that TRAIL-R regulates T cell-mediated immune responses by directly inhibiting T cell activation without inducing apoptosis; however, the distinct signaling pathway that regulates T cell activation remains unclear. In this study, we screened for intracellular TRAIL-R-binding proteins within T cells to explore the novel signaling pathway transduced by TRAIL-R that directly inhibits T cell activation. METHODS: Whole-transcriptome RNA sequencing was used to identify gene expression signatures associated with TRAIL-R signaling during T cell activation. High-throughput screening with mass spectrometry was used to identify the novel TRAIL-R binding proteins within T cells. Co-immunoprecipitation, lipid raft isolation, and confocal microscopic analyses were conducted to verify the association between TRAIL-R and the identified binding proteins within T cells. RESULTS: TRAIL engagement downregulated gene signatures in TCR signaling pathways and profoundly suppressed phosphorylation of TCR proximal tyrosine kinases without inducing cell death. The tyrosine phosphatase SHP-1 was identified as the major TRAIL-R binding protein within T cells, using high throughput mass spectrometry-based proteomics analysis. Furthermore, Lck was co-immunoprecipitated with the TRAIL-R/SHP-1 complex in the activated T cells. TRAIL engagement profoundly inhibited phosphorylation of Lck (Y394) and suppressed the recruitment of Lck into lipid rafts in the activated T cells, leading to the interruption of proximal TCR signaling and subsequent T cell activation. CONCLUSIONS: TRAIL-R associates with phosphatase SHP-1 and transduces a unique and distinct immune gatekeeper signal to repress TCR signaling and T cell activation via inactivating Lck. Thus, our results define TRAIL-R as a new class of immune checkpoint receptors for restraining T cell activation, and TRAIL-R/SHP-1 axis can serve as a potential therapeutic target for immune-mediated diseases.

Integrative analyses reveal outcome-associated and targetable molecular partnerships between TP53, BRD4, TNFRSF10B, and CDKN1A in diffuse large B-cell lymphoma.

Diffuse large B-cell lymphoma (DLBCL) is a common, genomically heterogenous disease that presents a clinical challenge despite the success of frontline regimens and second-line chimeric antigen receptor T-cell (CAR-T) therapy. Recently, genomic alterations and tumor microenvironment features associated with poor CAR-T response have been identified, namely those to the TP53 tumor suppressor gene. This retrospective analysis aimed to integrate various data to identify genomic partnerships capable of providing further clarity and actionable treatment targets within this population. Publicly available data were analyzed for differential expression based on TP53 and 24-month event-free survival (EFS24) status, revealing enrichments of the BRD4 bromodomain oncogene (p < 0.0001, p = 0.001). High-BRD4 and TP53 alterations were significantly associated with lower CDKN1A (p21) and TNFRSF10B (TRAIL-R2), a key tumor suppressor and CAR-T modulator, respectively. Significant loss of CD8 T-cell presence within low-TNFRSF0B (p = 0.0042) and altered-TP53 (p = 0.0424) patients showcased relevant outcome-associated tumor microenvironment features. Furthermore, reduced expression of CDKN1A was associated with low TNFRSF10B (FDR < 0.0001) and increased BRD4 interactant genes (FDR < 0.0001). Promisingly, in vitro MDM2 inhibition with Idasnutlin and TP53 reactivation via Eprenetapopt was able to renew TNFRSF10B protein expression. Additionally, applying the BRD4-degrading PROTAC ARV-825 and the CDK4/6 inhibitor Abemaciclib as single-agents and in synergistic combination significantly reduced TP53-altered DLBCL cell line viability. Our analysis presents key associations within a genomic network of actionable targets capable of providing clarity within the evolving precision CAR-T treatment landscape.

Rolapitant treats lung cancer by targeting deubiquitinase OTUD3.

BACKGROUND: Lung cancer is cancer with the highest morbidity and mortality in the world and poses a serious threat to human health. Therefore, discovering new treatments is urgently needed to improve lung cancer prognosis. Small molecule inhibitors targeting the ubiquitin-proteasome system have achieved great success, in which deubiquitinase inhibitors have broad clinical applications. The deubiquitylase OTUD3 was reported to promote lung tumorigenesis by stabilizing oncoprotein GRP78, implying that inhibition of OTUD3 may be a therapeutic strategy for lung cancer. RESULTS: In this study, we identified a small molecule inhibitor of OTUD3, Rolapitant, by computer-aided virtual screening and biological experimental verification from FDA-approved drugs library. Rolapitant inhibited the proliferation of lung cancer cells by inhibiting deubiquitinating activity of OTUD3. Quantitative proteomic profiling indicated that Rolapitant significantly upregulated the expression of death receptor 5 (DR5). Rolapitant also promoted lung cancer cell apoptosis through upregulating cell surface expression of DR5 and enhanced TRAIL-induced apoptosis. Mechanistically, Rolapitant directly targeted the OTUD3-GRP78 axis to trigger endoplasmic reticulum (ER) stress-C/EBP homologous protein (CHOP)-DR5 signaling, sensitizing lung cancer cells to TRAIL-induced apoptosis. In the vivo assays, Rolapitant suppressed the growth of lung cancer xenografts in immunocompromised mice at suitable dosages without apparent toxicity. CONCLUSION: In summary, the present study identifies Rolapitant as a novel inhibitor of deubiquitinase OTUD3 and establishes that the OTUD3-GRP78 axis is a potential therapeutic target for lung cancer.

PEG-lipid-modified agonistic antibody against tumor necrosis factor receptor family elicits superior apoptosis-inducing activity against human carcinoma.

We have recently developed a novel PEG-lipid-modified antibody to enhance the induction of apoptosis by the agonistic antibody. The chemically modified TRA-8 antibody [anti-death receptor 5 (DR5) antibody] with PEG-lipid (DSPE-PEG) demonstrated significant cytotoxic activity in vitro without the need for crosslinking with a secondary antibody, which is typically required. We investigated the correlation between the PEG-lipid structure and the cytotoxic activity of the modified antibodies by varying the PEG length or lipid structure. However, when the DSPE-PEG-modified TRA-8 antibody was incubated with plasma, it lost its cytotoxic activity, likely due to degradation in the DSPE-PEG component. Nevertheless, by designing new PEG-lipids that are intended to be resistant to enzymatic degradation, we were able to prevent this degradation and restore the cytotoxic activity of the modified antibody. These findings provide valuable insights for the design of PEG-lipid-modified antibodies and suggest their potential effectiveness in enhancing cancer therapy.

Ars2 regulates both miRNA- and siRNA- dependent silencing and suppresses RNA virus infection in Drosophila.

Intrinsic immune responses autonomously inhibit viral replication and spread. One pathway that restricts viral infection in plants and insects is RNA interference (RNAi), which targets and degrades viral RNA to limit infection. To identify additional genes involved in intrinsic antiviral immunity, we screened Drosophila cells for modulators of viral infection using an RNAi library. We identified Ars2 as a key component of Drosophila antiviral immunity. Loss of Ars2 in cells, or in flies, increases susceptibility to RNA viruses. Consistent with its antiviral properties, we found that Ars2 physically interacts with Dcr-2, modulates its activity in vitro, and is required for siRNA-mediated silencing. Furthermore, we show that Ars2 plays an essential role in miRNA-mediated silencing, interacting with the Microprocessor and stabilizing pri-miRNAs. The identification of Ars2 as a player in these small RNA pathways provides new insight into the biogenesis of small RNAs that may be extended to other systems.

Licochalcone D exhibits cytotoxicity in breast cancer cells and enhances tumor necrosis factor-related apoptosis-inducing ligand-induced apoptosis through upregulation of death receptor 5.

Anticancer strategies using natural products or derivatives are promising alternatives for cancer treatment. Here, we showed that licochalcone D (LCD), a natural flavonoid extracted from Glycyrrhiza uralensis Fisch, suppressed the growth of breast cancer cells, and was less toxic to MCF-10A normal breast cells. LCD-induced DNA damage, cell cycle arrest, and apoptosis in breast cancer cells. Furthermore, LCD potentiated tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced cytotoxicity. Mechanistically, LCD was revealed to reduce survival protein expression and to upregulate death receptor 5 (DR5) expressions. Silencing DR5 blocked the ability of LCD to sensitize cells to TRAIL-mediated apoptosis. LCD increased CCAAT/enhancer-binding protein homologous protein (CHOP) expression in breast cancer cells. Knockdown of CHOP attenuated DR5 upregulation and apoptosis triggered by cotreatment with LCD and TRAIL. Furthermore, LCD suppressed the phosphorylation of extracellular signal-regulated kinase and promoted the phosphorylation of c-Jun amino-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK). Pretreatment with JNK inhibitor SP600125 or p38 MAPK inhibitor SB203580 abolished the upregulation of DR5 and CHOP, and also attenuated LCD plus TRAIL-induced cleavage of poly(ADP-ribose) polymerase. Overall, our results show that LCD exerts cytotoxic effects on breast cancer cells and arguments TRAIL-mediated apoptosis by inhibiting survival protein expression and upregulating DR5 in a JNK/p38 MAPK-CHOP-dependent manner.

Pro-Inflammatory Activation Suppresses TRAIL-induced Apoptosis of Acute Myeloid Leukemia Cells.

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL/Apo2L) is a promising agent for treatment of AML due to its specific apoptosis-inducing effect on tumor cells but not normal cells. However, emergence of resistance to TRAIL in the AML cells limits its potential as an antileukemic agent. Previously, we revealed increase in the resistance of the human AML THP-1 cells to the TRAIL-induced death during their LPS-dependent proinflammatory activation and in the in vitro model of LPS-independent proinflammatory activation - in a long-term high-density cell culture. In this study, we investigated mechanisms of this phenomenon using Western blot analysis, caspase 3 enzymatic activity analysis, quantitative reverse transcription-PCR, and flow cytometry. The results showed that the increased resistance to the TRAIL-induced cell death of AML THP-1 cells during their pro-inflammatory activation is associated with the decrease in the surface expression of the proapoptotic receptors TRAIL-R1/DR4 and TRAIL-R2/DR5, as well as with the increased content of members of the IAPs family - Livin and cIAP2. The results of this article open up new insights into the role of inflammation in formation of the resistance of AML cells to the action of mediators of antitumor immunity, in particular TRAIL.

Large remodeling of the Myc-induced cell surface proteome in B cells and prostate cells creates new opportunities for immunotherapy.

MYC is a powerful transcription factor overexpressed in many human cancers including B cell and prostate cancers. Antibody therapeutics are exciting opportunities to attack cancers but require knowledge of surface proteins that change due to oncogene expression. To identify how MYC overexpression remodels the cell surface proteome in a cell autologous fashion and in different cell types, we investigated the impact of MYC overexpression on 800 surface proteins in three isogenic model cell lines either of B cell or prostate cell origin engineered to have high or low MYC levels. We found that MYC overexpression resulted in dramatic remodeling (both up- and down-regulation) of the cell surfaceome in a cell type-dependent fashion. We found systematic and large increases in distinct sets of >80 transporters including nucleoside transporters and nutrient transporters making cells more sensitive to toxic nucleoside analogs like cytarabine, commonly used for treating hematological cancers. Paradoxically, MYC overexpression also increased expression of surface proteins driving cell turnover such as TNFRSF10B, also known as death receptor 5, and immune cell attacking signals such as the natural killer cell activating ligand NCR3LG1, also known as B7-H6. We generated recombinant antibodies to these two targets and verified their up-regulation in MYC overexpression cell lines and showed they were sensitive to bispecific T cell engagers (BiTEs). Our studies demonstrate how MYC overexpression leads to dramatic bidirectional remodeling of the surfaceome in a cell type-dependent but functionally convergent fashion and identify surface targets or combinations thereof as possible candidates for cytotoxic metabolite or immunotherapy.

Therapeutic targeting of FOS in mutant TERT cancers through removing TERT suppression of apoptosis via regulating survivin and TRAIL-R2.

The telomerase reverse transcriptase (TERT) has long been pursued as a direct therapeutic target in human cancer, which is currently hindered by the lack of effective specific inhibitors of TERT. The FOS/GABPB/(mutant) TERT cascade plays a critical role in the regulation of mutant TERT, in which FOS acts as a transcriptional factor for GABPB to up-regulate the expression of GABPB, which in turn activates mutant but not wild-type TERT promoter, driving TERT-promoted oncogenesis. In the present study, we demonstrated that inhibiting this cascade by targeting FOS using FOS inhibitor T-5224 suppressed mutant TERT cancer cells and tumors by inducing robust cell apoptosis; these did not occur in wild-type TERT cells and tumors. Mechanistically, among 35 apoptotic cascade-related proteins tested, the apoptosis induced in this process specifically involved the transcriptional activation of tumor necrosis factor-related apoptosis-inducing ligand receptor 2 (TRAIL-R2) and inactivation of survivin, two key players in the apoptotic cascade, which normally initiate and suppress the apoptotic cascade, respectively. These findings with suppression of FOS were reproduced by direct knockdown of TERT and prevented by prior knockdown of TRAIL-R2. Further experiments demonstrated that TERT acted as a direct transcriptional factor of survivin, up-regulating its expression. Thus, this study identifies a therapeutic strategy for TERT promoter mutation-driven cancers by targeting FOS in the FOS/GABPB/(mutant) TERT cascade, circumventing the current challenge in pharmacologically directly targeting TERT itself. This study also uncovers a mechanism through which TERT controls cell apoptosis by transcriptionally regulating two key players in the apoptotic cascade.

Peritoneal Gene Transfection of Tumor Necrosis Factor-Related Apoptosis-Inducing Ligand for Tumor Surveillance and Prophylaxis.

Peritoneal metastasis is very common in gastrointestinal, reproductive, and genitourinary tract cancers in late stages or postsurgery, causing poor prognosis, so effective and nontoxic prophylactic strategies against peritoneal metastasis are highly imperative. Herein, we demonstrate the first gene transfection as a nontoxic prophylaxis preventing peritoneal metastasis or operative metastatic dissemination. Lipopolyplexes of TNF-related-apoptosis-inducing-ligand (TRAIL) transfected peritonea and macrophages to express TRAIL for over 15 days. The expressed TRAIL selectively induced tumor cell apoptosis while exempting normal tissue, providing long-term tumor surveillance. Therefore, tumor cells inoculated in the pretransfected peritoneal cavity quickly underwent apoptosis and, thus, barely formed tumor nodules, significantly prolonging the mouse survival time compared with chemotherapy prophylaxis. Furthermore, lipopolyplex transfection showed no sign of toxicity. Therefore, this peritoneal TRAIL-transfection is an effective and safe prophylaxis, preventing peritoneal metastasis.

Strophanthidin Induces Apoptosis of Human Lung Adenocarcinoma Cells by Promoting TRAIL-DR5 Signaling.

Strophanthidin (SPTD), one of the cardiac glycosides, is refined from traditional Chinese medicines such as Semen Lepidii and Antiaris toxicaria, and was initially used for the treatment of heart failure disease in clinic. Recently, SPTD has been shown to be a potential anticancer agent, but the underlying mechanism of action is poorly understood. Herein, we explored the molecular mechanism by which SPTD exerts anticancer effects in A549 human lung adenocarcinoma cells by means of mass spectrometry-based quantitative proteomics in combination with bioinformatics analysis. We revealed that SPTD promoted the expression of tumor necrosis factor (TNF)-related apoptosis-inducing ligand receptor 2 (TRAIL-R2, or DR5) in A549 cells to activate caspase 3/6/8, in particular caspase 3. Consequently, the activated caspases elevated the expression level of apoptotic chromatin condensation inducer in the nucleus (ACIN1) and prelamin-A/C (LMNA), ultimately inducing apoptosis via cooperation with the SPTD-induced overexpressed barrier-to-autointegration factor 1 (Banf1). Moreover, the SPTD-induced DEPs interacted with each other to downregulate the p38 MAPK/ERK signaling, contributing to the SPTD inhibition of the growth of A549 cells. Additionally, the downregulation of collagen COL1A5 by SPTD was another anticancer benefit of SPTD through the modulation of the cell microenvironment.

Efficient treatment of colon cancer with codelivery of TRAIL and imatinib by liposomes.

To solve the problem of resistance of tumor cells to TRAIL and the inevitable side effects of imatinib during treatment, we successfully prepared a kind of multifunctional liposome that encapsulated imatinib in its internal water phase and inserted TRAIL on its membrane in this study, which named ITLPs. The liposomes appeared uniform spherical and the particle size was approximately 150 nm. ITLPs showed high accumulation in TRAIL-resistance cells and HT-29 tumor-bearing mice model. In vitro cytotoxicity assay results showed that the killing activity of HT-29 cells treated with ITLPs increased by 50% and confirmed that this killing activity was mediated by the apoptosis pathway. Through mechanism studies, it was found that ITLPs arrested up to 32.3% of cells in phase M to exert anti-tumor effects. In vivo anti-tumor study showed that ITLPs achieved 61.8% tumor suppression and little toxicity in the HT-29 tumor-bearing mice model. Overall results demonstrated that codelivery of imatinib and TRAIL via liposomes may be a prospective method in the treatment of the TRAIL-resistance tumor.