On-demand integrated nano-engager converting cold tumors to hot via increased DNA damage and dual immune checkpoint inhibition

Cancer immunotherapy has become a promising strategy. However, the effectiveness of immunotherapy is restricted in "cold tumors" characterized with insufficient T cells intratumoral infiltration and failed T cells priming. Herein, an on-demand integrated nano-engager (JOT-Lip) was developed to convert cold tumors to hot via "increased DNA damage and dual immune checkpoint inhibition" strategy. JOT-Lip was engineered by co-loading oxaliplatin (Oxa) and JQ1 into liposomes with T-cell immunoglobulin mucin-3 antibodies (Tim-3 mAb) coupled on the liposomal surface by metalloproteinase-2 (MMP-2)-sensitive linker. JQ1 inhibited DNA repair to increase DNA damage and immunogenic cell death (ICD) of Oxa, thus promoting T cells intratumoral infiltration. In addition, JQ1 inhibited PD-1/PD-L1 pathway, achieving dual immune checkpoint inhibition combining with Tim-3 mAb, thus effectively promoting T cells priming. It is demonstrated that JOT-Lip not only increased DNA damage and promoted the release of damage-associated molecular patterns (DAMPs), but also enhanced T cells intratumoral infiltration and promoted T cell priming, which successfully converted cold tumors to hot and showed significant anti-tumor and anti-metastasis effects. Collectively, our study provides a rational design of an effective combination regimen and an ideal co-delivery system to convert cold tumors to hot, which holds great potential in clinical cancer chemoimmunotherapy.

Clinical significance of expression of tumor immunogenic cell death related molecules / 国际肿瘤学杂志

Tumor immunogenic cell death is a type of regulatory cell death, which is driven by stress including chemotherapy drugs, radiotherapy, oncolytic virus, nano carrier drugs and photodynamic force. It can induce specific immune response to tumor death cell antigen. The further study can provide theoretical basis and new ideas for anti-tumor immunity and clinical immunotherapy of tumor.

Stimuli-responsive nano vehicle enhances cancer immunotherapy by coordinating mitochondria-targeted immunogenic cell death and PD-L1 blockade

Induction of immunogenic cell death promotes antitumor immunity against cancer. However, majority of clinically-approved drugs are unable to elicit sufficient ICD. Here, our study revealed that mitochondria-targeted delivery of doxorubicin (DOX) massively amplified ICD via substantial generation of reactive oxygen species (ROS) after mitochondrial damage. The underlying mechanism behind increased ICD was further demonstrated to be ascribed to two pathways: (1) ROS elevated endoplasmic reticulum (ER) stress, leading to surface exposure of calreticulin; (2) ROS promoted release of various mitochondria-associated damage molecules including mitochondrial transcription factor A. Nevertheless, adaptive upregulation of PD-L1 was found after such ICD-inducing treatment. To overcome such immunosuppressive feedback, we developed a tumor stimuli-responsive nano vehicle to simultaneously exert mitochondrial targeted ICD induction and PD-L1 blockade. The nano vehicle was self-assembled from ICD-inducing copolymer and PD-L1 blocking copolymer, and possessed long-circulating property which contributed to better tumor accumulation and mitochondrial targeting. As a result, the nano vehicle remarkably activated antitumor immune responses and exhibited robust antitumor efficacy in both immunogenic and non-immunogenic tumor mouse models.

Perfluorooctyl bromide nanoemulsions holding MnO2 nanoparticles with dual-modality imaging and glutathione depletion enhanced HIFU-eliciting tumor immunogenic cell death

Tumor-targeted immunotherapy is a remarkable breakthrough, offering the inimitable advantage of specific tumoricidal effects with reduced immune-associated cytotoxicity. However, existing platforms suffer from low efficacy, inability to induce strong immunogenic cell death (ICD), and restrained capacity of transforming immune-deserted tumors into immune-cultivated ones. Here, an innovative platform, perfluorooctyl bromide (PFOB) nanoemulsions holding MnO2 nanoparticles (MBP), was developed to orchestrate cancer immunotherapy, serving as a theranostic nanoagent for MRI/CT dual-modality imaging and advanced ICD. By simultaneously depleting the GSH and eliciting the ICD effect via high-intensity focused ultrasound (HIFU) therapy, the MBP nanomedicine can regulate the tumor immune microenvironment by inducing maturation of dendritic cells (DCs) and facilitating the activation of CD8+ and CD4+ T cells. The synergistic GSH depletion and HIFU ablation also amplify the inhibition of tumor growth and lung metastasis. Together, these findings inaugurate a new strategy of tumor-targeted immunotherapy, realizing a novel therapeutics paradigm with great clinical significance.

Highly penetrable nanoparticles co-loading doxorubicin and IDO1 siRNA enhance tumor immunotherapy / 药学学报

There are two serious obstacles to tumor immunotherapy. Firstly, the immune response of the tumor is seriously reduced due to immunosuppressive tumor microenvironment (ITM) and low immunogenicity of tumor. The second obstacle is the dense and complex heterogeneous structures, which seriously prevent the nanoparticles (NPs) from penetrating deeper into tumor tissue. Immunogenic cell death (ICD) induced by doxorubicin (DOX) is an effective method to enhance tumor immune activity. However, interferon-γ (IFN-γ) secreted by cytotoxic T lymphocytes (CTL) after ICD induction would increase the expression of indoleamine 2,3-dioxygenase 1 (IDO1) and enhance ITM. IDO1 siRNA would reduce the expression of IDO1 protein, regulate the tumor immunosuppressive microenvironment and regulate ITM, so as to enhance the ICD effect of DOX. In this paper, a novel charge conversional, particle size reduction and highly penetrable NPs based on a pH sensitive copolymer poly(ethylene glycol)-poly-L-lysine-2,3-dimethylmaleic anhydride (mPEG-PLL-DMA, PLD) and polyamidoamine (PAMAM) dendrimers to achieve deep delivery of tumor tissue. DOX and IDO1 siRNA were encapsulated to achieve efficient tumor immunotherapy. Preparation and cell level experiments showed that PLD material had significant pH sensitivity. Results of 3D tumor penetrable experiment in vitro showed that adding the pH sensitive material PLD significantly improved the permeability of the preparation. In addition, 4T1 tumor model was established for BALB/c mice and all animal experiments were displayed in according with the requirements of the Animal Experiment Ethics Committee of Shenyang Pharmaceutical University. The results of in vivo efficacy experiments and tissue experiments evaluated that IDO1 siRNA significantly improved the ICD effect owing to DOX, so as to significantly inhibit tumor growth.

Research progress of endoplasmic reticulum targeting drug delivery system for anti-tumor immunotherapy / 药学学报

Endoplasmic reticulum (ER), a multifunctional organelle in eukaryotic cells, is responsible for protein synthesis and intracellular signal transduction, which dominates cell function, survival, and apoptosis. Disequilibrium of ER homeostasis may induce ER stress, which closely intertwines with tumor occurrence and progress. A few clinical-used drugs (such as anthraquinones and oxaliplatin) can mediate the immunogenic cell death of tumor cells through excessive ER stress, and sequentially stimulate anti-tumor immune responses as well as long-term immune memory. However, these drugs often exhibit poor targeting ability and extremely low ER accumulation in tumor cells, limiting their clinical efficacy. Therefore, the researches of ER-targeted delivery of these drugs will significantly benefit the efficient and precise anti-tumor immunotherapy. In this review, we introduce the relationship between ER and tumor immunity, and summarize the ER targeting strategies for anti-tumor immunotherapy in recent years. Furthermore, we discuss the problems of existing ER targeting strategies and look into its broad prospects of application.

Enzyme-instructed and mitochondria-targeting peptide self-assembly to efficiently induce immunogenic cell death

Immunogenic cell death (ICD) plays a major role in cancer immunotherapy by stimulating specific T cell responses and restoring the antitumor immune system. However, effective type II ICD inducers without biotoxicity are still very limited. Herein, a tentative drug- or photosensitizer-free strategy was developed by employing enzymatic self-assembly of the peptide F-pY-T to induce mitochondrial oxidative stress in cancer cells. Upon dephosphorylation catalyzed by alkaline phosphatase overexpressed on cancer cells, the peptide F-pY-T self-assembled to form nanoparticles, which were subsequently internalized. These affected the morphology of mitochondria and induced serious reactive oxygen species production, causing the ICD characterized by the release of danger-associated molecular patterns (DAMPs). DAMPs enhanced specific immune responses by promoting the maturation of DCs and the intratumoral infiltration of tumor-specific T cells to eradicate tumor cells. The dramatic immunotherapeutic capacity could be enhanced further by combination therapy of F-pY-T and anti-PD-L1 agents without visible biotoxicity in the main organs. Thus, our results revealed an alternative strategy to induce efficient ICD by physically promoting mitochondrial oxidative stress.

Bispecific prodrug nanoparticles circumventing multiple immune resistance mechanisms for promoting cancer immunotherapy

Cancer immunotherapy is impaired by the intrinsic and adaptive immune resistance. Herein, a bispecific prodrug nanoparticle was engineered for circumventing immune evasion of the tumor cells by targeting multiple immune resistance mechanisms. A disulfide bond-linked bispecific prodrug of NLG919 and JQ1 (namely NJ) was synthesized and self-assembled into a prodrug nanoparticle, which was subsequently coated with a photosensitizer-modified and tumor acidity-activatable diblock copolymer PHP for tumor-specific delivery of NJ. Upon tumor accumulation via passive tumor targeting, the polymeric shell was detached for facilitating intracellular uptake of the bispecific prodrug. NJ was then activated inside the tumor cells for releasing JQ1 and NLG919 via glutathione-mediated cleavage of the disulfide bond. JQ1 is a bromodomain-containing protein 4 inhibitor for abolishing interferon gamma-triggered expression of programmed death ligand 1. In contrast, NLG919 suppresses indoleamine-2,3-dioxygenase 1-mediated tryptophan consumption in the tumor microenvironment, which thus restores robust antitumor immune responses. Photodynamic therapy (PDT) was performed to elicit antitumor immunogenicity by triggering immunogenic cell death of the tumor cells. The combination of PDT and the bispecific prodrug nanoparticle might represent a novel strategy for blockading multiple immune evasion pathways and improving cancer immunotherapy.

Multifunctional polymeric micelle-based chemo-immunotherapy with immune checkpoint blockade for efficient treatment of orthotopic and metastatic breast cancer

Immunotherapy has become a highly promising paradigm for cancer treatment. Herein, a chemo-immunotherapy was developed by encapsulating chemotherapeutic drug doxorubicin (DOX) and Toll-like receptor 7 agonist imiquimod (IMQ) in low molecular weight heparin (LMWH)-d--tocopheryl succinate (TOS) micelles (LT). In this process, LMWH and TOS were conjugated by ester bond and they were not only served as the hydrophilic and hydrophobic segments of the carrier, but also exhibited strong anti-metastasis effect. The direct killing of tumor cells mediated by DOX-loaded micelles (LT-DOX) generated tumor-associated antigens, initiating tumor-specific immune responses in combination with IMQ-loaded micelles (LT-IMQ). Furthermore, the blockade of immune checkpoint with programmed cell death ligand 1 (PD-L1) antibody further elevated the immune responses by up-regulating the maturation of DCs as well as the ratios of CD8 CTLs/T and CD4 T/T. Therefore, such a multifunctional strategy exhibited great potential for inhibiting the growth of orthotopic and metastatic breast cancer.

Perspectives for cancer immunotherapy mediated by p19Arf plus interferon-beta gene transfer

While cancer immunotherapy has gained much deserved attention in recent years, many areas regarding the optimization of such modalities remain unexplored, including the development of novel approaches and the strategic combination of therapies that target multiple aspects of the cancer-immunity cycle. Our own work involves the use of gene transfer technology to promote cell death and immune stimulation. Such immunogenic cell death, mediated by the combined transfer of the alternate reading frame (p14ARF in humans and p19Arf in mice) and the interferon-β cDNA in our case, was shown to promote an antitumor immune response in mouse models of melanoma and lung carcinoma. With these encouraging results, we are now setting out on the road toward translational and preclinical development of our novel immunotherapeutic approach. Here, we outline the perspectives and challenges that we face, including the use of human tumor and immune cells to verify the response seen in mouse models and the incorporation of clinically relevant models, such as patient-derived xenografts and spontaneous tumors in animals. In addition, we seek to combine our immunotherapeutic approach with other treatments, such as chemotherapy or checkpoint blockade, with the goal of reducing dosage and increasing efficacy. The success of any translational research requires the cooperation of a multidisciplinary team of professionals involved in laboratory and clinical research, a relationship that is fostered at the Cancer Institute of Sao Paulo.

Immunogenic cell death of human osteosarcoma cells MG-63 induced by capsaicin / 基础医学与临床

Objective To investigate the effect of capsaicin and cisplatin on the proliferation and immunogenic cell death of human osteosarcoma cells.Methods MTT assay was used to examine the growth inhibiting effects of capsacin and cisplation on MG-63 cells;Mitochondrial membrane potential (MMP) was used to investigate the apoptosis;flow cytometry was used to detect the expression of calreticulin (CRT) on the cell membrane,fluorescein enzymatic method was used to detect the release of ATP,ELISA was used to detect the secretion of high mobility group B1 (HMGB1).Results Capsaicin and cisplatin can inhibit MG-63 cells proliferation in the dose-dependent manner and induce MG-63 apoptosis(P＜0.01).Only capsaicin can induce translocation of CRT from endoplasmic reticulum to the cell surface and release of extracellular ATP and HMGB1 (P＜0.01).Conclusions Capsaicin can induce human osteosarcoma cells apoptosis and immunogenic cell death.

Chemotherapy and tumor immunogenic cell death / 国际肿瘤学杂志

Chemotherapy resist is the problem for clinic,and some researches find that chemotherapy with anthracycline and oxaliplatin not only induces the tumor cell apoptosis,but also the celt immunogenic cell death (ICD) by inducing the tumor cell apoptosis and releasing three kinds of signals:exposure of calreticulin on the cell surface to stimulate the dendritic cell (DC) to engulf,and the secretion of adenosine triphosphate to recruit DC to enter into tumor bed,and the release of the high mobility group B1 to promote DC to steadily bind with dying tumor cell to induce specific T cell antitumor immune response.It is with great meaning to promote the chemotherapy protocol by studying the ICD induced by chemotherapy.

Immunogenic Cell Death Induced by Ginsenoside Rg3: Significance in Dendritic Cell-based Anti-tumor Immunotherapy

Cancer is one of the leading causes of morbidity and mortality worldwide; therefore there is a need to discover new therapeutic modules with improved efficacy and safety. Immune-(cell) therapy is a promising therapeutic strategy for the treatment of intractable cancers. The effectiveness of certain chemotherapeutics in inducing immunogenic tumor cell death thus promoting cancer eradication has been reported. Ginsenoside Rg3 is a ginseng saponin that has antitumor and immunomodulatory activity. In this study, we treated tumor cells with Rg3 to verify the significance of inducing immunogenic tumor cell death in antitumor therapy, especially in DC-based immunotherapy. Rg3 killed the both immunogenic (B16F10 melanoma cells) and non-immunogenic (LLC: Lewis Lung Carcinoma cells) tumor cells by inducing apoptosis. Surface expression of immunogenic death markers including calreticulin and heat shock proteins and the transcription of relevant genes were increased in the Rg3-dying tumor. Increased calreticulin expression was directly related to the uptake of dying tumor cells by dendritic cells (DCs): the proportion of CRT+ CD11c+ cells was increased in the Rg3-treated group. Interestingly, tumor cells dying by immunogenic cell death secreted IFN-gamma, an effector molecule for antitumor activity in T cells. Along with the Rg3-induced suppression of pro-angiogenic (TNF-alpha) and immunosuppressive cytokine (TGF-beta) secretion, IFN-gamma production from the Rg3-treated tumor cells may also indicate Rg3 as an effective anticancer immunotherapeutic strategy. The data clearly suggests that Rg3-induced immunogenic tumor cell death due its cytotoxic effect and its ability to induce DC function. This indicates that Rg3 may be an effective immunotherapeutic strategy.

Mechanism of immunogenic cell death induced by microwave ablation in treatment of osteosarcoma / 中华放射肿瘤学杂志

Objective As a classical approach for hyperthermic ablation,microwave ablation (MWA) has been widely used in the treatment of tumors that cannot be removed by traditional surgery.MWA devitalizes the neighboring tissue and kills tumor cells by thermal diffusion.In the last two decades,this technique has been improved for treating malignant bone tumor in our institute.In situ ablation has already replaced en bloc resection and achieved satisfactory treatment outcomes.This study explores whether tumor cell death induced by MWA would cause the release of immunogenic tumor antigens and tumor-specific immune responses.Methods Three models of MWA were established using osteosarcoma cell lines from the mouse,rat,and human,respectively.The expression of immunogenic molecules was measured during in vitro and in situ ablation with different ablation time and group design.Results The injection of tumor vaccines made from tumor cells or supernatant treated with in vitro ablation resulted in substantial inhibition of tumor cell growth in tumor-bearing animal models.The CDs + T cells induced by vaccines played a key role in the process.The effector cells released cytokines,IFN-γand TNF-α,to inhibit tumor cell growth and also trigger Fas/FasL-mediated apoptosis.Conclusions MWA-treated osteosarcoma cells can be used to induce specific antitumor immunogenic effects.Therefore,in situ MWA combined with immunotherapy provides an alternative treatment method for patients who have trouble due to their insensitivity to chemotherapy.