Survival Of Tumor-bearing Mice Research Articles

Macrophage hitchhiking for systematic suppression in postablative multifocal HCC.

HCC, particularly the multifocal HCC, features aggressive invasion and dismal prognosis. Locoregional treatments were often refractory to eliminate tumor tissue, resulting in residual tumor cells persisting and subsequent progression. Owing to problematic delivery to the tumor tissue, systemic therapies, such as lenvatinib (LEN) therapy, show limited clinical benefit in preventing residual tumor progression. Therefore, more advanced strategies for postablative multifocal HCC are urgently needed. Motivated by the chemotaxis in tumor penetration of macrophages, we report a strategy named microinvasive ablation-guided macrophage hitchhiking for the targeted therapy toward HCC. In this study, the strategy leverages the natural inflammatory gradient induced by ablation to guide LEN-loaded macrophages toward tumor targeting, which increased by ~10-fold the delivery efficiency of LEN in postablative HCC in vivo. Microinvasive ablation-guided macrophage hitchhiking has demonstrated significant antitumor activity in various HCC models, including the hydrodynamic tail vein injection multifocal HCC mouse model and the orthotopic xenograft HCC rabbit model, systematically inhibiting residual tumor progression after ablation and prolonging the median survival of tumor-bearing mice. The potential antitumor mechanism was explored using techniques such as flow cytometry, ELISA, and immunohistochemistry. We found that the strategy significantly suppressed tumor cell proliferation and neovascularization, and such enhanced delivery of LEN stimulated systemic immune responses and induced durable immune memory. The macrophage hitchhiking strategy demonstrates exceptional therapeutic efficacy and biosafety across various species, offering promising prospects for clinical translation in controlling residual tumor progression and improving outcomes following HCC ablation.

Combination of miR159 Mimics and Irinotecan Utilizing Lipid Nanoparticles for Enhanced Treatment of Colorectal Cancer.

Colorectal cancer (CRC) ranks as the third most prevalent global malignancy, marked by significant metastasis and post-surgical recurrence, posing formidable challenges to treatment efficacy. The integration of oligonucleotides with chemotherapeutic drugs emerges as a promising strategy for synergistic CRC therapy. The nanoformulation, lipid nanoparticle (LNP), presents the capability to achieve co-delivery of oligonucleotides and chemotherapeutic drugs for cancer therapy. In this study, we constructed lipid nanoparticles, termed as LNP-I-V by microfluidics to co-deliver oligonucleotides miR159 mimics (VDX05001SI) and irinotecan (IRT), demonstrating effective treatment of CRC both in vitro and in vivo. The LNP-I-V exhibited a particle size of 118.67 ± 1.27 nm, ensuring excellent stability and targeting delivery to tumor tissues, where it was internalized and escaped from the endosome with a pH-sensitive profile. Ultimately, LNP-I-V significantly inhibited CRC growth, extended the survival of tumor-bearing mice, and displayed favorable safety profiles. Thus, LNP-I-V held promise as an innovative platform to combine gene therapy and chemotherapy for improving CRC treatment.

Spatiotemporally Controlled T-Cell Combination Therapy for Solid Tumor.

Due to multidimensional complexity of solid tumor, development of rational T-cell combinations and corresponding formulations is still challenging. Herein, a triple combination of T cells are developed with Indoleamine 2,3-dioxygenase inhibitors (IDOi) and Cyclin-dependent kinase 4/6 inhibitors (CDK4/6i). To maximize synergism, a spatiotemporally controlled T-cell engineering technology to formulate triple drugs into one cell therapeutic, is established. Specifically, a sequentially responsive core-shell nanoparticle (SRN) encapsulating IDOi and CDK4/6i is anchored onto T cells. The yielded SRN-T cells migrated into solid tumor, and achieved a 1st release of IDOi in acidic tumor microenvironment (TME). Released IDOi restored tryptophan supply in TME, which activated effector T cells and inhibited Tregs. Meanwhile, 1st released core is internalized by tumor cells and degraded by glutathione (GSH), to realize a 2nd release of CDK4/6i, which induced up-regulated expression of C-X-C motif chemokine ligand 10 (CXCL10) and C-C motif chemokine ligand 5 (CCL5), and thus significantly increased tumor infiltration of T cells. Together, with an enhanced recruitment and activation, T cells significantly suppressed tumor growth, and prolonged survival of tumor-bearing mice. This study demonstrated rationality and superiority of a tri-drug combination mediated by spatiotemporally controlled cell-engineering technology, which provides a new treatment regimen for solid tumor.

Abstract LB294: Targeting fatty acid oxidation to boost the anti-tumor effects of nutrient starvation in solid malignancies

Abstract Introduction Reducing glucose and growth factor provision to cancer cells through in vitro starvation (STV) or in vivo fasting/fasting-mimicking diets (FMDs) delays tumor progression and prolongs survival in tumor-bearing mice. More recently, cyclic FMD has been shown to be safe and associated with promising metabolic and immunomodulatory effects in cancer patients. However, cyclic fasting and FMD only retard tumor progression, but they do not result in tumor cure when used alone. Here, we hypothesized that tumor cells exposed to STV activate Fatty Acid Oxidation (FAO) as an alternative metabolic pathway that could be responsible for primary or acquired tumor cell resistance to STV. Methods We investigated the effects of FAO inhibition (FAOi) in combination with STV on the proliferation and survival of human or murine cell lines of Triple Negative Breast Cancer (TNBC) (n=16), HR+HER2- breast cancer (n=3), colorectal (n=1), pancreatic (n=1) and lung cancer (n=1), as well as of non-transformed human epithelial cells (n=3). STV consisted of a 50% reduction of extracellular glucose and serum in cell growth media. To inhibit FAO, we used the Carnitine Palmitoyl transferase 1 inhibitor Etomoxir or ST1326. Results STV+FAOi resulted in cooperative or highly synergistic antiproliferative effects in all cancer models tested, but not in normal cells. At longer time points, STV+FAOi enhanced tumor cell death through the activation of apoptosis. Depending on the specific tumor type, the cooperative effects of STV and FAOi were mostly mediated by glucose or fatty acid restriction in the STV medium. On the other hand, the reduction of extracellular growth factors did not affect cell proliferation upon STV+FAOi combination. Intracellular ATP levels were reduced upon cell exposure to the combined treatment at later time points. However, the supplementation of several sources of ATP, such as glutamine or TCA cycle intermediates, to tumor cells did not rescue the antitumor effects of STV+FAOi, thus excluding the strong impact of this combination on tumor cell bioenergetics. On the other hand, STV+FAOi caused an excessive intracellular antioxidant response, which in part mediated the synergistic effects of STV+FAOi. Indeed, Etomoxir alone mildly increased the NADPH/NADP+ ratio, whereas its combination with STV resulted in a remarkable increase of this ratio. In parallel, combining the antioxidant molecules n-acetylcysteine (NAC) and reduced glutathione (GSH) with FAOi caused antitumor effects that recapitulate those produced by STV+FAOi treatment. Conclusions FAO is a potential resistance mechanism to nutrient starvation, with broad antitumor activity in different models of murine and human malignancies, but not in normal cells. In cancer cells, FAOi synergizes with STV by strongly affecting intracellular redox balance. FAOi is a new strategy that should be explored in future preclinical in vivo experiments and in clinical studies to potentiate the antitumor effects of nutrient starvation in solid malignancies. Citation Format: Marzia Santamaria, Beatrice Cantarelli, Arta Ajazi, Chiara Milanese, Giulia Salvadori, Pier Giorgio Mastroberardino, Paola Antonia Corsetto, Giancarlo Pruneri, Filippo De Braud, Claudio Vernieri. Targeting fatty acid oxidation to boost the anti-tumor effects of nutrient starvation in solid malignancies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr LB294.

JAML promotes the antitumor role of tumor-resident CD8+ T cells by facilitating their innate-like function in human lung cancer

Tissue-resident memory CD8+T cells (CD8+TRMs) are thought to play a crucial role in cancer immunosurveillance. However, the characteristics of CD8+TRMs in the tumor microenvironment (TME) of human non-small cell lung cancer (NSCLC) remain unclear. Here, we report that CD8+TRMs accumulate explicitly and exhibit a unique gene expression profile in the TME of NSCLC. Interestingly, these tumor-associated CD8+TRMs uniquely exhibit an innate-like phenotype. Importantly, we found that junction adhesion molecule-like (JAML) provides an alternative costimulatory signal to activate tumor-associated CD8+TRMs via combination with cancer cell-derived CXADR (CXADR Ig-like cell adhesion molecule). Furthermore, we demonstrated that activating JAML could promote the expression of TLR1/2 on CD8+TRMs, inhibit tumor progression and prolong the survival of tumor-bearing mice. Finally, we found that higher CD8+TRMs and JAML expression in the TME could predict favorable clinical outcomes in NSCLC patients. Our study reveals an intrinsic bias of CD8+TRMs for receiving the tumor-derived costimulatory signal in the TME, which sustains their innate-like function and antitumor role. These findings will shed more light on the biology of CD8+TRMs and aid in the development of potential targeted treatment strategies for NSCLC.

Site-specific Antibody-Nitric Oxide Conjugate HN02 Possesses Improved Antineoplastic and Safety Properties.

Antibody-drug conjugates (ADCs) combine the high specificity of antibodies with the cytotoxicity of payloads and have great potential in pan-cancer immunotherapy. However, the current payloads for clinical uses have limited the therapeutic window due to their uncontrollable off-site toxicity. There is unmet needs to develop more potent ADC payloads with better safety and efficacy profiles. Nitric oxide (NO) is a special molecule that has low toxicity itself, which can kill tumor cells effectively when highly concentrated, has broad application prospects. Previously, we prepared for the first time an antibody-nitric oxide conjugate (ANC)-HN01, which showed inhibitory activity against hepatocellular carcinoma. However, the random conjugation method made HN01 highly heterogeneous and unstable. Here, we used site-specific conjugation-based engineered cysteine sites (CL-V211C) of anti-CD24 antibody to prepare a second-generation ANC with a drug-to-antibody ratio of 2. The homogeneous ANC, HN02 was stable in human plasma, shown in vitro bystander effect to neighboring cells and antiproliferative activity to CD24-targeted tumor cells. Compared with HN01, HN02 significantly prolonged the survival of tumor-bearing mice. In summary, we developed a stable and homogeneous site-specific conjugated ANC, which showed good antitumor activity and improved safety profile both in vitro and in vivo. This study provides new insight into the development of next generation of ADC candidates.

Abstract 4049: The beta-carboline Harmine sensitives microsatellite stable colorectal cancer mouse model to anti-PD-1 through upregulating MHC-I dependent antigen presentation machinery and improving the infiltration of CD8 T cells into the tumor microenvironment

Abstract Colorectal cancer (CRC) is the most common gastrointestinal cancer and the third leading cause of cancer-related death in both sexes. Mismatch repair deficient/microsatellite instability-high (MSI) colorectal cancer patients benefit from immune checkpoint blockades (ICBs)-based immunotherapy; however, this benefit has not been translated into microsatellite stable (MSS) colorectal cancer. It has been proposed that the loss of major histocompatibility complex class I (MHC-I) in tumor cells limits the use of ICB in colorectal cancer. Harmine displays a number of biological and pharmacological properties affecting the immune response and tumor phenotype. Here, we assessed the impact of combining harmine, also referred to as ACB1801 molecule, on improving the responsiveness of ICB in the mouse MSS CRC model. Our results showed that combining ACB1801 significantly improves the therapeutic benefit of anti-PD-1 in the CT26 CRC mouse model by decreasing tumor growth and improving the survival of tumor-bearing mice. The improvement of anti-PD-1-based therapy by combining ACB-1801 was associated with a modification of the immune landscape of tumors as evidenced by an increase in the CD8+ T cells and a decrease in the Treg infiltrations into the tumor microenvironment. By profiling the cytokine/chemokine network, we showed that ACB1801 induced the expression and the release of the proinflammatory chemokine CXCL10 by CRC tumor cells in vitro, which could be responsible for driving CD8+ T cells to the tumor microenvironment. Mechanistically, we showed that ACB1801 increased the expression of MHC-I genes, including TAP1 and TAPASIN, and improved the antigen loading on MHC-I in CRC cells in vitro. Overall, our study highlights the value of combining ACB1801 and anti-PD-1 as a therapeutic opportunity to convert MSS colorectal cancer into an “immune hot” cancer, which may define the future treatment paradigm of colorectal cancer for which there is a great unmet need. Citation Format: Ruize Gao, Kris Van Moer, Coralie Pulido, Anaïs Oudin, Diane Murera, Teresa L. Ramos, Margaux Poussard, Andreas Schläpfer, Annette Ives, Christian Auclair, Bassam Janji. The beta-carboline Harmine sensitives microsatellite stable colorectal cancer mouse model to anti-PD-1 through upregulating MHC-I dependent antigen presentation machinery and improving the infiltration of CD8 T cells into the tumor microenvironment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4049.

Abstract 2921: Extended treatment with IAP inhibitor xevinapant post radiotherapy improves therapeutic efficacy and promotes antitumor immunity in preclinical models

Abstract Background: Xevinapant is a first-in-class, oral IAP (inhibitor of apoptosis protein) inhibitor designed to restore cancer cell sensitivity to apoptosis induced by radiotherapy (RT) and chemotherapy. In a randomized phase 2 study of patients with unresected locally advanced squamous cell carcinoma of the head and neck, xevinapant + chemoradiotherapy (CRT) significantly improved locoregional control at 18 months, 3-year progression-free survival and nearly doubled 5-year overall survival vs. placebo + CRT (53% vs. 28%). Two phase 3 trials, in which patients receive 6 cycles of xevinapant or placebo monotherapy (3 cycles in combination with standard-of-care (C)RT followed by 3 cycles of monotherapy), are ongoing. Based on the roles of IAPs in apoptosis and tumor immunity, continual dosing of xevinapant post RT may deliver additional therapeutic benefit through modulation of multiple tumor microenvironment (TME) compartments. Methods: The impact on antitumor efficacy of xevinapant dosing duration was evaluated in A1419 (head and neck), LLC (lung) and MC38 (colorectal) syngeneic tumor-bearing mice treated with vehicle control, RT alone (3.6Gy, QD, 5 days), or RT + xevinapant (100 mg/kg, QD, 1, 2, or 4 weeks). To assess treatment-mediated TME modulation in MC38 tumors, RNAseq and FACS-based immune profiling was performed, followed by functional validation with ex vivo ELISpot assays, in vitro immunogenic cell death assays, T cell activation assays, and macrophage polarization and viability assays. To evaluate the effect of xevinapant on RT-induced cancer associated fibroblast (CAF) activation and CAF-modulated immune phenotype, activation assay and cytokine profiling was performed. Results: In the tumor models tested, RT in combination with extended xevinapant dosing markedly improved efficacy and prolonged survival compared to treatment arms of RT with shorter xevinapant dosing durations, RT alone, and vehicle control. RNAseq and FACS analyses suggested a TME with enhanced antitumor immunity, while ELISpot and in vitro T cell assays confirmed that extended xevinapant dosing promoted antigen-specific T cell response and T cell activation. Furthermore, macrophage polarization and viability assays suggested that xevinapant reduced the viability of M2 macrophages which may have contributed to the increased M1:M2 macrophage ratio and the improved antitumor immune response observed in vivo. In addition, via the suppression of RT-mediated CAF activation, xevinapant may promote M1 polarization of macrophages and recruitment of T cells by upregulating GM-CSF and CXCL10 in CAFs. Conclusions: Extended dosing of xevinapant post concurrent RT improved antitumor efficacy and prolonged survival of tumor-bearing mice. Mechanistic investigation suggested that such benefit may be, in part, modulated by xevinapant enhanced antitumor immunity. Citation Format: Tsz-Lun Yeung, Feng Jiang, Hui Huang, Huakui Yu, Li-Ya Chiu, Mathilde Bonnemaison, Bo Marelli, Roberta Ferretti, Ralph Lindemann, Christina Esdar. Extended treatment with IAP inhibitor xevinapant post radiotherapy improves therapeutic efficacy and promotes antitumor immunity in preclinical models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2921.

Effective therapy of advanced breast cancer through synergistic anticancer by paclitaxel and P-glycoprotein inhibitor

Multi-drug resistance (MDR) in advanced breast cancer (ABC) is triggered by the high expression of P-glycoprotein (P-gp), which reduces intracellular concentration of anti-tumor drugs, in turn preventing oxidative stress damage to cytoplasmic and mitochondrial membranes. It is therefore of clinical relevance to develop P-gp-specific targeted nanocarriers for the treatment of drug resistant ABC. Herein, a drug carrier targeting CD44 and mitochondria was synthesised for the delivery of encequidar (ER, P-gp inhibitor) and paclitaxel (PTX). HT@ER/PTX nanoparticles (ER:PTX molar ratio 1:1) had excellent P-gp inhibition ability and targeted mitochondria to induce apoptosis in MCF-7/PTX cells in vitro. Furthermore, HT@ER/PTX nanocarriers showed more anti-tumor efficacy than PTX (Taxol®) in a xenograft mouse model of MCF-7/PTX cells; the tumor inhibitory rates of HT@ER/PTX nanoparticles and Taxol® were 72.64% ± 4.41% and 32.36% ± 4.09%, respectively. The survival of tumor-bearing mice administered HT@ER/PTX nanoparticles was prolonged compared to that of the mice treated with Taxol®. In addition, HT@ER/PTX not only inhibited P-gp-mediated removal of toxic lipid peroxidation byproducts resulting from anti-tumor drugs but also upregulated the expression of mitochondrial dynamics-related protein, fostering oxidative stress damage, which induced activation of the Caspase-3 apoptosis pathway. Our findings indicate that mitochondria targeted co-delivery of anti-tumor drugs and P-gp inhibitors could be a practical approach in treating multi-drug resistance in ABC.

Biomimetic Nanovehicle-Enabled Targeted Depletion of Intratumoral Fusobacterium nucleatum Synergizes with PD-L1 Blockade against Breast Cancer.

Immune checkpoint blockade (ICB) therapy has been approved for breast cancer (BC), but clinical response rates are limited. Recent studies have shown that commensal microbes colonize a variety of tumors and are closely related to the host immune system response. Here, we demonstrated that Fusobacterium nucleatum (F.n), which is prevalent in BC, creates an immunosuppressive tumor microenvironment (ITME) characterized by a high-influx of myeloid cells that hinders ICB therapy. Administering the antibiotic metronidazole in BC can deplete F.n and remodel the ITME. To prevent an imbalance in the systemic microbiota caused by antibiotic administration, we designed a biomimetic nanovehicle for on-site antibiotic delivery inspired by F.n homing to BC. Additionally, ferritin-nanocaged doxorubicin was coloaded into this nanovehicle, as immunogenic chemotherapy has shown potential for synergy with ICB. It has been demonstrated that this biomimetic nanovehicle can be precisely homed to BC and efficiently eliminate intratumoral F.n without disrupting the diversity and abundance of systemic microbiota. This ultimately remodels the ITME, improving the therapeutic efficacy of the PD-L1 blocker with a tumor inhibition rate of over 90% and significantly extending the median survival of 4T1 tumor-bearing mice.

Intra-bone marrow injection with engineered Lactococcus lactis for the treatment of metastatic tumors: Primary report

Bone marrow has the capacity to produce different types of immune cells, such as natural killer cells, macrophages, dendritic cells (DCs) and T cells. Improving the activation of immune cells in the bone marrow can enhance the therapy of bone metastases. Previously, we designed an engineered probiotic Lactococcus lactis, capable of expressing a fusion protein of Fms-like tyrosine kinase 3 ligand and co-stimulator OX40 ligand (FOLactis), and proved that it can induce the activation and differentiation of several immune cells. In this research, we successfully establish mouse models of bone metastasis, lung metastasis and intraperitoneal dissemination, and we are the first to directly inject the probiotics into the bone marrow to inhibit tumor growth. We observe that injecting FOLactis into the bone marrow of mice can better regulate the immune microenvironment of tumor-bearing mice, resulting in a tumor-suppressive effect. Compared to subcutaneous (s.c.) injection, intra-bone marrow (IBM) injection is more effective in increasing mature DCs and CD8+ T cells and prolonging the survival of tumor-bearing mice. Our results confirm that IBM injection of FOLactis reprograms the immune microenvironment of bone marrow and has remarkable effectiveness in various metastatic tumor models.

SESN1 functions as a new tumor suppressor gene via Toll-like receptor signaling pathway in neuroblastoma.

Neuroblastoma (NB) is the most common extracranial solid tumor in children, with a 5-year survival rate of <50% in high-risk patients. MYCN amplification is an important factor that influences the survival rate of high-risk patients. Our results indicated MYCN regulates the expression of SESN1. Therefore, this study aimed to investigate the role and mechanisms of SESN1 in NB. siRNAs or overexpression plasmids were used to change MYCN, SESN1, or MyD88's expression. The role of SESN1 in NB cell proliferation, migration, and invasion was elucidated. Xenograft mice models were built to evaluate SESN1's effect invivo. The correlation between SESN1 expression and clinicopathological data of patients with NB was analyzed. RNA-Seq was done to explore SESN1's downstream targets. SESN1 was regulated by MYCN in NB cells. Knockdown SESN1 promoted NB cell proliferation, cell migration, and cell invasion, and overexpressing SESN1 had opposite functions. Knockdown SESN1 promoted tumor growth and shortened tumor-bearing mice survival time. Low expression of SESN1 had a positive correlation with poor prognosis in patients with NB. RNA-Seq showed that Toll-like receptor (TLR) signaling pathway, and PD-L1 expression and PD-1 checkpoint pathway in cancer were potential downstream targets of SESN1. Knockdown MyD88 or TLRs inhibitor HCQ reversed the effect of knockdown SESN1 in NB cells. High expression of SESN1 was significantly associated with a higher immune score and indicated an active immune microenvironment for patients with NB. SESN1 functions as a new tumor suppressor gene via TLR signaling pathway in NB.

Enzyme/pH Dual-Responsive Engineered Nanoparticles for Improved Tumor Immuno-Chemotherapy.

Combining immune checkpoint blockade (ICB) therapy with chemotherapy can enhance the efficacy of ICB and expand its indications. However, the limited tumor specificity of chemotherapy drugs results in severe adverse reactions. Additionally, the low tissue penetration and immune-related adverse events associated with monoclonal antibodies restrict their widespread application. To address challenges faced by traditional combination therapies, we design a dual-responsive engineered nanoparticle based on ferritin (denoted as CMFn@OXA), achieving tumor-targeted delivery and controlled release of the anti-PD-L1 peptide CLP002 and oxaliplatin (OXA). Our results demonstrate that CMFn@OXA not only exhibits tumor-specific accumulation but also responds to matrix metalloproteinase-2/9 (MMP-2/9), facilitating the controlled release of CLP002 to block PD-1/PD-L1 interaction. Simultaneously, it ensures the precise delivery of the OXA to tumor cells and its subsequent release within the acidic environment of lysosomes, thereby fostering a synergistic therapeutic effect. Compared to traditional combination therapies, CMFn@OXA demonstrates superior performance in inhibiting tumor growth, extending the survival of tumor-bearing mice, and exhibiting excellent biocompatibility. Collectively, our results highlight CMFn@OXA as a novel and promising strategy in the field of cancer immunotherapy.

A Thermosensitive Bi-Adjuvant Hydrogel Triggers Epitope Spreading to Promote the Anti-Tumor Efficacy of Frameshift Neoantigens.

Tumor-specific frameshift mutations encoding peptides (FSPs) are highly immunogenic neoantigens for personalized cancer immunotherapy, while their clinical efficacy is limited by immunosuppressive tumor microenvironment (TME) and self-tolerance. Here, a thermosensitive hydrogel (FSP-RZ-BPH) delivering dual adjuvants R848 (TLR7/8 agonist) + Zn2+ (cGAS-STING agonist) is designed to promote the efficacy of FSPs on murine forestomach cancer (MFC). After peritumoral injection, FSP-RZ-BPH behaves as pH-responsive sustained drug release at sites near the tumor to effectively transform the immunosuppressive TME into an inflammatory type. FSP-RZ-BPH orchestrates innate and adaptive immunity to activate dendritic cells in tumor-draining lymph nodes and increase the number of FSPs-reactive effector memory T cells (TEM) in tumor by 2.9 folds. More importantly, these TEM also exhibit memory responses to nonvaccinated neoantigens on MFC. This epitope spreading effect contributes to reduce self-tolerance to maintain long-lasting anti-tumor immunity. In MFC suppressive model, FSP-RZ-BPH achieves 84.8% tumor inhibition rate and prolongs the survival of tumor-bearing mice with 57.1% complete response rate. As a preventive tumor vaccine, FSP-RZ-BPH can also significantly delay tumor growth. Overall, the work identifies frameshift MFC neoantigens for the first time and demonstrates the thermosensitive bi-adjuvant hydrogel as an effective strategy to boost bystander anti-tumor responses of frameshift neoantigens.

Spatiotemporal transformable nano-assembly for on-demand drug delivery to enhance anti-tumor immunotherapy

Induction of tumor cell senescence has become a promising strategy for anti-tumor immunotherapy, but fibrotic matrix severely blocks senescence inducers penetration and immune cells infiltration. Herein, we designed a cancer-associated fibroblasts (CAFs) triggered structure-transformable nano-assembly (HSD-P@V), which can directionally deliver valsartan (Val, CAFs regulator) and doxorubicin (DOX, senescence inducer) to the specific targets. In detail, DOX is conjugated with hyaluronic acid (HA) via diselenide bonds (Se-Se) to form HSD micelles, while CAFs-sensitive peptide is grafted onto the HSD to form a hydrophilic polymer, which is coated on Val nanocrystals (VNs) surface for improving the stability and achieving responsive release. Once arriving at tumor microenvironment and touching CAFs, HSD-P@V disintegrates into VNs and HSD micelles due to sensitive peptide detachment. VNs can degrade the extracellular matrix, leading to the enhanced penetration of HSD. HSD targets tumor cells, releases DOX to induce senescence, and recruits effector immune cells. Furthermore, senescent cells are cleared by the recruited immune cells to finish the integrated anti-tumor therapy. In vitro and in vivo results show that the nano-assembly remarkably inhibits tumor growth as well as lung metastasis, and extends tumor-bearing mice survival. This work provides a promising paradigm of programmed delivering multi-site nanomedicine for cancer immunotherapy.

RNA Origami Functions as a Self-Adjuvanted Nanovaccine Platform for Cancer Immunotherapy.

Peptide-based vaccines have been widely investigated in cancer immunotherapy. Despite their high specificity, safety, and low production cost, these vaccines have shown limited success in clinical studies, owing to their poor immunogenicity. Extensive efforts have been devoted to increasing the immunogenicity of peptide vaccines by mixing peptides with adjuvants and/or promoting their delivery to tumor-draining lymph nodes (TdLNs) for better antigen presentation by and maturation of dendritic cells. Among these efforts, the exploration of various nanoparticles has been at the forefront of the rational design and construction of peptide-based vaccines. Here, we present a nanovaccine platform that is built on a self-assembled RNA origami (RNA-OG) nanostructure. As previously reported, this RNA-OG nanostructure is a potent toll-like receptor (TLR)3 agonist. In addition, due to its robust synthesis and versatility in modification, RNA-OG could be readily linked to peptides of interest. Thus, these RNA-OG nanostructures function as adjuvanted nanocarriers to construct RNA-OG-peptide nanovaccines that are uniform in size, consistent in peptide loading, and highly stable. Here, we demonstrate that the assembled RNA-OG-peptide nanovaccines induced dendritic cell maturation, reduced tumor-mediated immunosuppression, and mobilized tumor-specific CD8+ T cell responses at the tumor site. Together, these actions led to the elicitation of an effective antitumor immunity that increased the survival of tumor-bearing mice. The combination of RNA-OG-based nanovaccines with the α-PD-1 immune checkpoint blockade further enhanced the immunity. Hence, our RNA-OG nanostructures represent a robust, simple, and highly effective platform to empower peptide-based vaccines for cancer immunotherapy.

Adoptive cell transfer therapy with ex vivo primed peripheral lymphocytes in combination with anti-PDL1 therapy effectively inhibits triple-negative breast cancer growth and metastasis

BackgroundAdoptive cell transfer cancer immunotherapy holds promise for treating disseminated disease, yet generating sufficient numbers of lymphocytes with anti-cancer activity against diverse specificities remains a major challenge. We recently developed a novel procedure (ALECSAT) for selecting, expanding and maturating polyclonal lymphocytes from peripheral blood with the capacity to target malignant cells.MethodsImmunodeficient mice were challenged with triple-negative breast cancer cell lines or patient-derived xenografts (PDX) and treated with allogeneic or autologous ALECSAT cells with and without anti-PDL1 therapy to assess the capacity of ALECSAT cells to inhibit primary tumor growth and metastasis.ResultsALECSAT mono therapy inhibited metastasis, but did not inhibit primary tumor growth or prolong survival of tumor-bearing mice. In contrast, combined ALECSAT and anti-PDL1 therapy significantly inhibited primary tumor growth, nearly completely blocked metastasis, and prolonged survival of tumor-bearing mice.ConclusionsCombined ALECSAT and anti-PDL1 therapy results in favorable anti-cancer responses in both cell line-derived xenograft and autologous PDX models of advanced triple-negative breast cancer.

The Wnt-pathway corepressor TLE3 interacts with the histone methyltransferase KMT1A to inhibit differentiation in Rhabdomyosarcoma.

Rhabdomyosarcoma tumor cells resemble differentiating skeletal muscle cells, which unlike normal muscle cells, fail to undergo terminal differentiation, underlying their proliferative and metastatic properties. We identify the corepressor TLE3 as a key regulator of rhabdomyosarcoma tumorigenesis by inhibiting the Wnt-pathway. Loss of TLE3 function leads to Wnt-pathway activation, reduced proliferation, decreased migration, and enhanced differentiation in rhabdomyosarcoma cells. Muscle-specific TLE3-knockout results in enhanced expression of terminal myogenic differentiation markers during normal mouse development. TLE3-knockout rhabdomyosarcoma cell xenografts result in significantly smaller tumors characterized by reduced proliferation, increased apoptosis and enhanced differentiation. We demonstrate that TLE3 interacts with and recruits the histone methyltransferase KMT1A, leading to repression of target gene activation and inhibition of differentiation in rhabdomyosarcoma. A combination drug therapy regime to promote Wnt-pathway activation by the small molecule BIO and inhibit KMT1A by the drug chaetocin led to significantly reduced tumor volume, decreased proliferation, increased expression of differentiation markers and increased survival in rhabdomyosarcoma tumor-bearing mice. Thus, TLE3, the Wnt-pathway and KMT1A are excellent drug targets which can be exploited for treating rhabdomyosarcoma tumors.

Ganoderma lucidum spore oil enhances the effect of paclitaxel, improves the tolerance to paclitaxel and prolongs the survival in Lewis tumor-bearing mice

Ganoderma lucidum spore oil enhances the effect of paclitaxel, improves the tolerance to paclitaxel and prolongs the survival in Lewis tumor-bearing mice

Cell Membrane Hybrid Lipid Nanovesicles Enhance Innate Immunity for Synergistic Immunotherapy by Promoting Immunogenic Cell Death and cGAS Activation.

Immunotherapy shows great therapeutic potential for long-term protection against tumor relapse and metastasis. Innate immune sensors, such as cyclic GMP-AMP synthase (cGAS) and stimulator of interferon genes (STING), dissolve DNA and induce type I interferon. Through activation of the cGAS/STING pathway, chemotherapy drugs and reversine (REV) may provide synergetic anti-tumor effects. Here, we prepared drug-loaded cell membrane hybrid lipid nanovesicles (LEVs) (designated LEV@DOX@REV) by fusion of cell membranes, phospholipids, doxorubicin (DOX), and REV, to realize accurate delivery to tumors and chemo-immunotherapy. The cell membranes of LEVs confer "homing" abilities. DOX can induce immunogenic cell death as a result of its specific immunomodulatory effects, which promotes the maturation of immune cells and improves the microenvironment of the immune system. REV is proven to efficiently activate cGAS/STING signaling, thereby enhancing the immune system. The antitumor efficacy of LEV@DOX@REV was evaluated in a 4T1 subcutaneous tumor xenograft model, a distant metastatic tumor model, and a liver metastatic tumor model. LEV@DOX@REV facilitated the infiltration of cytotoxic T lymphocytes within tumors, increased the secretion of proinflammatory cytokines, and modified the tumor microenvironment. In conclusion, LEV@DOX@REV displayed favorable antitumor effects and extended the survival of tumor-bearing mice. We therefore successfully developed nanoparticles capable of enhancing immune activation that have potential therapeutic applications for cancer immunotherapy.