Immunogenic Death Research Articles

DDEL-16. MICROMESH FOR REVAMPING THE ‘COLD’ TUMOR MICROENVIRONMENT IN GLIOBLASTOMA IMMUNOTHERAPY

Abstract High-grade gliomas have poor prognoses with limited treatment options, typically maximal safe resection and adjuvant radiochemotherapy. Novel therapies often face challenges due to low brain penetrance and poor bioavailability. To address these issues, a conformable, compartmentalized polymeric implant called microMESH has been developed. microMESH provides localized, sustained release of drugs, small inhibitors, antibodies, and nanomedicines, enabling novel therapeutic combinations. When applied to the tumor margins, microMESH adheres to the tissue, releasing its therapeutic cargo over weeks and reducing systemic toxicity. Its biocompatibility, cytotoxicity, and anti-tumor efficacy were tested on murine cancer cells (CT-2A) and orthotopic glioblastoma syngeneic models. Exposing primary bone marrow-derived monocytes (BMDM) to CT-2A conditioned medium increased the expression of anti-inflammatory cytokines (IL-10 and IL-4) by 2 times without significantly affecting the pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6), indicating that CT-2A cells tend to establish an immunosuppressive ‘cold’ tumor microenvironment. Next, the co-incubation of CT-2A cells with BMDM followed by the administration of the immune checkpoint inhibitor aCD47 resulted in a cancer cell viability drop by 50% already at 50 μg/ml aCD47 after 1 day. Additionally, pre-treatment with docetaxel (DTXL) further decreased cell viability, suggesting a synergism between aCD47 and the chemotherapeutic drug. Flow cytometry showed that 50 nM DTXL at 3 days post-incubation was responsible for a strong translocation of the ‘immunogenic dell death’ protein calreticulin on the cell membrane, potentially explaining the synergism. Over 2 months, the intracranially deployed microMESH biodegraded without inducing any toxic effect. In orthotopic CT-2A tumors, aCD47/DTXL–microMESH (0.75 mg/kg, single intracranial application) showed a 40-day survival compared to 22 days for iv DTXL (3 mg/kg qod), 24 days for ip aCD47 (5 mg/kg qod), and 18 days for untreated mice. microMESH helped identify and enabled novel combination therapies directly at the tumor bed, demonstrating superior efficacy over systemic therapies.

Exploring structure-directed immunogenic cytotoxicity of arginine-rich peptides for cytolysis-induced immunotherapy of cancer

The same cells can die with varied immunological consequences. For the purpose of cancer therapy, stronger immunogenic death of cancer cells is considered favorable. Membrane disruptive peptides are cytotoxic agents with tunable structures capable of not just killing heterogeneous cancer cells, but also inducing immunogenic death. However, the chemo-structural principles that underlie their immunogenic cytotoxicity remain elusive. Here we investigated a series of arginine-rich amphipathic peptides with representative structures on the relationship between the mode of cell death and the immunogenic potency. Among several hydrophobic motif-appended cyclic octaarginine peptides, FC-14 was found to induce cell stress and necroptotic death, unlike apoptotic peptide RL2 and membrane-dissolving peptide RL1. Their differing abilities to release immunogenic death markers correlated well with their potential to activate innate immunity and protective vaccinal effect in a prophylactic model, with FC-14 being the most potent. FC-14 can be pre-opsonized with albumin into nanoparticles (PopAN-FC-14) using PopAN technology to improve its pharmacokinetic properties for intravenous injection. In a syngeneic mouse model of subcutaneous breast cancer, PopAN-FC-14 showed superior therapeutic effect and safety profile than the albumin formulated nanomedicine Nab-paclitaxel (Nab-PTX). Boost injections of PopAN-FC-14 significantly enhanced tumor-specific cellular and humoral immunities, acting similarly as in-situ cancer vaccine. Overall, this work demonstrates a novel focus on the immunogenic cytotoxicity of peptides and a practical approach for effective systemic therapy of cancer.

Full-active pharmaceutical ingredient nanosensitizer for augmented photoimmunotherapy by synergistic mitochondria targeting and immunogenic death inducing.

The precise and effective activation of the immune response is crucial in promising therapy curing cancer. Photoimmunotherapy (PIT) is an emerging strategy for precise regulation and highly spatiotemporal selectivity. However, this approach faces a significant challenge due to the off-target effect and the immunosuppressive microenvironment. To address this challenge, a nanoscale full-active pharmaceutical ingredient (API) photo-immune stimulator was developed. This formulation overcomes the limitations of PIT by strengthening the ability to penetrate tumors deeply and inducing precise and potent mitochondria-targeted dual-mode photodynamic therapy and photothermal therapy. Along with inhibiting overexpressed Hsp90, this nanosensitizer in turn improves the immunosuppressive microenvironment. Ultimately, this mitochondria-targeted PIT demonstrated potent antitumor efficacy, achieving a remarkable inhibition rate of ≥95% for both established primary tumors and distant abscopal tumors. In conclusion, this novel self-delivery full-API nanosystem enhances the efficacy of phototherapy and reprograms the immunosuppressive microenvironment, thereby holding great promise in the development of precise and effective immunotherapy.

Tumor-Derived Extracellular Vesicles Enable Tumor Tropism Chemo-Genetherapy for Local Immune Activation in Triple-Negative Breast Cancer.

Triple-negative breast cancer (TNBC) is highly heterogeneous, lacks accessible therapeutic targets, and features an immunosuppressive tumor microenvironment (TME). Anthracycline-based chemotherapy remains the primary treatment method for TNBC, while the current popular immune checkpoint inhibitors persistently encounter therapeutic resistance. Therefore, there is an urgent need to explore combined therapeutic strategies to remodel the TME and improve the treatment response. Considering the highly specific homing ability of tumor cell-derived vesicles and the key role of the signal transduction and activation of the transcription factor 3 (STAT3) pathway in TNBC, we propose a synergistic therapeutic strategy that integrates gene therapy, chemotherapy, and immunotherapy based on STAT3 short interfering RNA (siSTAT3) and doxorubicin (DOX)-functionalized tumor-derived extracellular vesicles (TEVs) (siSTAT3-DOX@TEV). The in vitro and in vivo results demonstrate that siSTAT3-DOX@TEV target tumor tissues precisely, downregulate STAT3 expression, and synergistically and efficiently induce immunogenic death, thereby reversing the immunosuppressive TME. Moreover, mass cytometry and immunohistochemistry reveal the local immune activation effect of siSTAT3-DOX@TEV, with a significant increase in M1 macrophages, CD4+ T cells, and CD8+ T cells in tumor tissues. These results provide strong hints for the development of TEV-based chemo-gene therapeutic agents for TNBC treatment at the clinical level.

Tumor specific in situ synthesis of therapeutic agent for precision cancer therapy

BackgroundTraditional chemotherapeutic agents suffer from a lack of selectivity, poor targeting ability, and drug resistance. Developing tumor-specific therapies is crucial for precisely eliminating tumors while circumventing toxicity to normal tissues. Disulfiram (DSF), an FDA-approved drug for treating alcohol dependence, exhibits antitumor effect by forming complexes with copper ions (Cu(DDC)2). Here, we developed a Cu-doped polydopamine-based nanosystem (DSF@CuPDA-PEGM) to achieve in situ generation of toxic Cu(DDC)2.ResultsIn cancer cells with elevated H2O2 contents, CuPDA responsively degrades to release Cu ions and DSF, allowing on-site synthesis of Cu(DDC)2 with potent antitumor activity. DSF@CuPDA-PEGM exhibits excellent therapeutic efficacy against both drug-sensitive and drug-resistant cancer cells while minimizing toxicity to noncancerous cells. Moreover, DSF@CuPDA-PEGM promotes the immune response by inducing cancer cell immunogenic death, thereby augmenting anti-PD-1-based immune checkpoint blockade therapy.ConclusionA tumor-specifically degradable Cu-doped polydopamine-based nanosystem is developed to achieve in situ synthesis of antitumor compounds, providing a promising approach to precisely eliminate tumors and heighten chemo-immunotherapy.Graphical

Synergizing autophagic cell death and oxaliplatin-induced immunogenic death by a self-delivery micelle for enhanced tumor immunotherapy

Chemotherapy has become an emerging strategy to activate cytotoxic T cell responses by inducing immunogenic cell death (ICD), but the level of antitumor immunity induced by chemotherapeutic agents, such as oxaliplatin (OXA), is limited due to inadequate tumor antigen presentation and T cell activation. Inducing autophagic cell death (ACD) promotes the release of tumor antigen and the recruitment of dendritic cells, therefore strengthening antitumor immune responses. Here we simultaneously activate ICD and ACD with tumor targeting micelle to achieve enhanced antitumor chemo-immunotherapy. A self-delivery micelle is formulated by conjugating OXA prodrug with tocopherol succinate (TOS) as a hydrophobic segment and further encapsulates autophagy activator SMER28 to afford TOPR/SMER28, which specifically targets αvβ3 on tumor cells with c(RGDfK). Upon cellular internalization, OXA is released from the prodrug in response to the high concentration of reduced glutathione (GSH) in tumor cells, triggering ICD and releasing associated molecular patterns (DAMPs) signaling molecules to stimulate immunity. Meanwhile, SMER28 over-activates autophagy to induce autophagic cell death, which further leads to the maturation of dendritic cells and ultimately activates anti-tumor immune response. In the 4T1 tumor-bearing mice, the combination of OXA and SMER28 effectively inhibits tumor growth and activates antitumor immune responses. The tumor targeted micelle releases OXA and SMER28 in an on-demand profile and strengthens tumor chemo-immunotherapy by synergizing ICD and ACD, providing an alternative for antitumor immunotherapy. Statement of significanceChemotherapy induces immunogenic cell death (ICD) to activate anti-tumor immunity. However, the efficacy is limited by low levels of antigen presentation and T cell activation. To strengthen the antitumor immune responses induced by ICD, we first combine autophagic cell death (ACD) with ICD by formulating a glutathione-responsive oxaliplatin prodrug micelle co-encapsulating the autophagy activator SMER28. The activated autophagic level by SMER28 enhances the release of antigen and the recruitment of APCs, and ultimately bolsters T cell-mediated antitumor immune responses. We provide a potential strategy to amplify antitumor immune effects by combining autophagy activation with chemotherapy.

Oncogenic miRNAs dependent photothermal-immunotherapy enhanced by on-demand manipulation of immunosuppressive microenvironment using engineered gold nanoparticles for effective treatment of primary and metastatic tumor

Although photothermal-immunotherapy has emerged as a promising strategy to treat malignant tumor, unexpected thermal damage, continuous tumor migration and immunosuppressive microenvironment still limit its application. To improve the therapeutic efficacy, two types of engineered gold nanoparticles (SNAs@CCM and SNA2@CCM-Man) were fabricated. The SNAs@CCM are cancer cell membrane (CCM, tumor targeting agent) coated spherical nucleic acids (SNAs, miR-21 catcher and photothermal agent). The SNAs contained two types (SNA1 and SNA2), which are gold nanoparticles grafted with the first half and second half of anti-miR-21 oligonucleotide, respectively. The SNA2@CCM-Man are CCM coated SNA2 (miR-21 catcher) in which the CCM was functionalized by mannose (Man, macrophage targeting agent). These nanoparticles were expected to not only perform miR-21 dependent photothermal-immunotherapy in tumor cells to precisely damage primary tumor and activate the anti-tumor immune response against metastatic tumor, but also restrain the miR-21 expression in tumor-associated M2-type macrophages to promote their polarization to tumor-suppressed M1-type macrophages for on-demand manipulation of immunosuppressive microenvironment avoiding immune escape. After injection, the SNAs@CCM and SNA2@CCM-Man would respectively internalize by tumor cells and M2-type macrophages via homologous targeting of cancer cell membranes and receptor-ligand interactions of mannose. Upon entry into tumor cells, the SNAs specifically hybridized with the over-expressed miR-21 in these cells, thereby silencing the oncogenic miR-21 and leading to significant intracellular aggregation of SNAs. These aggregated SNAs not only served as miR-21 catcher, but performed a strong absorption in the near-infrared region acting as in situ photothermal agents. Under NIR irradiation, these photothermal agents enable highly selective photothermal-immunotherapy, inducing the immunogenic death of primary tumors and subsequent anti-tumor immune responses via the maturation of dendritic cells (DCs) and activation of T cells. Moreover, the miR-21 plunder process also effectively inhibited the migration of tumor cells to further enhance the therapeutic efficacy. Simultaneously, the similar miR-21 capture process mediated by SNA2 in M2 macrophages continuously induced macrophage polarization towards the anti-tumor M1 type, which was able to reverse the immunosuppressive microenvironment in tumor tissue to avoid immune escape and enhance immunotherapy. Both in vivo and in vitro experiments demonstrated that our nanoparticles could inhibit the primary tumor and its metastasis through miR-21-dependent photothermal immune activation and directional polarization of macrophages, providing a promising strategy for on-demand synchronous modulation of tumor cells and immune cells in tumor tissues for better malignant tumor therapy.

Functional co-delivery nanoliposomes based on improving hypoxia for increasing photoimmunotherapy efficacy of cold tumors

Cold tumors lack T cells infiltration and have low immunogenicity, resulting insufficient immunotherapy response. Therefore, how to realize the transformation from cold tumor to hot tumor is an urgent problem to be solved. Photodynamic therapy can induce immunogenic death of tumor cells (ICD) and activate T lymphocytes to produce tumor immune response. However, hypoxia in the cold tumor microenvironment limits the effectiveness of photodynamic therapy. So in this article, MET-HMME/CAT-HMME@Nlip as a functional co-delivery nanoliposomes was constructed based on overcoming the above problems. Firstly, the oxygen-deficient state could be improved by the following two ways, one is catalase loaded in CAT-HMME@Nlip can decompose high concentration hydrogen peroxide to produce oxygen, and the other is metformin loaded in MET-HMME@Nlip can decrease oxygen consumption by inhibiting of mitochondrial respiration. And then with the increase of substrate oxygen concentration, the sensitivity of photodynamic therapy can be greatly improved and the anti-tumor immune response by PDT-induced ICD can also be enhanced obviously. In addition, metformin could act as a small molecule immune checkpoint inhibitor to reduce the expression of PD-L1 on the surface of tumor cells, thereby effectively improving the specific killing ability of cytotoxic T cells to tumor cells which could not only erasing the primary tumor, but also inhibiting the growth of simulated distant tumors through the immune memory function. This study provides a new idea for improving the clinical treatment effect of hypoxic cold tumors, especially for tumors that could not benefit from immunotherapy due to low or no expression of PD-L1 protein on the surface of tumor cells.

Synergistic Photothermal Tumor Immunotherapy by 1-MT Based on Zeolitic Imidazolate Framework-8 with pH-High Sensitivity.

A successful immune response against tumors depends on various cellular processes. Hence, there is an urgent need to construct a proficient nanoplatform for immunotherapy that can concurrently regulate the activities of various cells participating in the immune process. We have developed zeolitic imidazolate framework-8 (ZIF-8) formula, with good pH sensitivity, which is conducive to the release of drugs in the tumor site (acidic environment) and significantly improves immunotherapy. This is achieved through the coordinated action of different therapeutic agents, such as the photothermal agent polydopamine (PDA), the chemodrug camptothecin (CPT), and the immunomodulator 1-methyl-D-tryptophan (1-MT). In this study, we evaluated the antitumor effect of PDA/(CPT + 1-MT) @ZIF-8 (PCMZ) nanoparticles (NPs) in vitro and in vivo and investigated the molecular mechanism of PCMZ NPs in tumor suppression via photothermal-chemo-immunotherapy. MTT and Annexin V-FITC/PI double staining apoptosis test showed that PCMZ NPs could induce apoptosis of 4T1 cell, and PCMZ NPs could cause 4T1 cell necrosis under 808 nm laser irradiation. The objective is to establish a unilateral breast cancer model in mice and investigate the effect of PCMZ NPs on tumor growth and tumor suppression in tumor bearing mice. The results showed that PCMZ NPs showed good heating effect in vivo and effectively inhibited tumor growth under 808 nm laser irradiation. In addition, PCMZ NPs could induce the immunogenic death of tumor cells, promote the maturation of DCs, inhibit IDO pathway, and finally differentiate T cells into cytotoxic T cells and helper T cells, so as to effectively activate the anti-tumor immune response. The PCMZ NPs, possessing good photothermal conversion capabilities due to join of PDA, effectively overcome two main challenges in immunotherapy: insufficient stimulation of the immune response and evasion of the immune system. This provides a robust platform against invasive cancer and recurrent tumors.

Reprogramming Tumor-Associated Macrophages with a Se-Based Core-Satellite Nanoassembly to Enhance Cancer Immunotherapy.

Tumor-associated macrophages (TAMs), as the most prevalent immune cells in the tumor microenvironment, play a pivotal role in promoting tumor development through various signaling pathways. Herein, we have engineered a Se@ZIF-8 core-satellite nanoassembly to reprogram TAMs, thereby enhancing immunotherapy outcomes. When the nanoassembly reaches the tumor tissue, selenium nanoparticles and Zn2+ are released in response to the acidic tumor microenvironment, resulting in a collaborative effort to promote the production of reactive oxygen species (ROS). The generated ROS, in turn, activate the nuclear factor κB (NF-κB) signaling pathway, driving the repolarization of TAMs from M2-type to M1-type, effectively eliminating cancer cells. Moreover, the nanoassembly can induce the immunogenic death of cancer cells through excess ROS to expose calreticulin and boost macrophage phagocytosis. The Se@ZIF-8 core-satellite nanoassembly provides a potential paradigm for cancer immunotherapy by reversing the immunosuppressive microenvironment.

Tumor Growth Inhibition and Induced the Immunogenic Death of Tumor Cells in Prostate Tumor Bone Metastases by Photothermal Therapy Mediated with Au Nanoparticles Modified with PDA

AbstractUpon progression to the metastatic stage, prostate tumors commonly exhibit multi‐drug resistance. Combining multiple treatment protocols can be beneficial in overcoming this resistance, which is often attributed to tumor heterogeneity. Recently, nano‐photosensitizer‐mediated photothermal therapy is shown to inhibit tumor growth through multiple pathways, including thermal ablation and activation of the antitumor immune response. In this study, gold nanoparticles (Au) are selected as the core photosensitizer. Then, the photothermal conversion of Au is augmented through dopamine coating, and the chemotherapy drug doxorubicin (DOX) is grafted to the dopamine coating. The release of DOX from DOX‐loaded dopamine‐modified gold nanoparticles (Au@PDA@DOX) occurred in response to an acidic environment. The combination of chemotherapy and thermal ablation better inhibits the growth, migration, and invasion of tumor cells and induced tumor cell apoptosis and necrosis in vitro. More importantly, thermal ablation induces the immunogenic death of prostate tumor cells (RM‐1) cells. The transition of prostate tumors from a “cold” to a “hot” tumor with immunogenicity is observed. The combination effectively activates the antitumor immune response, inhibits tumor growth, and alleviated bone damage by tumors in vivo. It is indicated that Au@PDA@DOX nanoparticles will offer a novel treatment protocol for prostate tumor bone metastases.

PH/glutathione-responsive theranostic nanoprobes for chemoimmunotherapy and magnetic resonance imaging of ovarian cancer cells

The integration of immunotherapy and standard chemotherapy holds great promise for enhanced anticancer effects. In this study, we prepared a pH- and glutathione (GSH)-sensitive manganese-doped mesoporous silicon (MMSNs) based drug delivery system by integrating paclitaxel (PTX) and anti-programmed cell death-ligand 1 antibody (aPD-L1), and encapsulating with polydopamine (PDA) for chemoimmunosynergic treatment of ovarian cancer cells. The nanosystem was degraded in response to the tumor weakly acidic and reductive microenvironment. The Mn2+ produced by degradation can be used as a contrast agent for magnetic resonance (MR) imaging to provide visual exposure to tumor tissue. The released PTX can not only kill tumor cells directly, but also induce immunogenic death (ICD) of tumor cells, which can play a synergistic therapeutic effect with aPD-L1. Therefore, our study is expected to provide a promising strategy for improving the efficacy of cancer immunotherapy and the detection rate of cancer.

Oral Heterojunction Coupling Interventional Optical Fiber Mediates Synergistic Therapy for Orthotopic Rectal Cancer.

Catalytic therapy has shown great potential for clinical application. However, conventional catalytic therapies rely on reactive oxygen species (ROS) as "therapeutic drugs," which have limitations in effectively inhibiting tumor recurrence and metastasis. Here, a biomimetic heterojunction catalyst is developed that can actively target orthotopic rectal cancer after oral administration. The heterojunction catalyst is composed of quatrefoil star-shaped BiVO4 (BVO) and ZnIn2S4 (ZIS) nanosheets through an in situ direct growth technique. Poly-norepinephrine and macrophage membrane coatings afford the biomimetic heterojunction catalyst (BVO/ZIS@M), which has high rectal cancer targeting and retention abilities. The coupled optical fiber intervention technology activates the multicenter coordination of five catalytic reactions of heterojunction catalysts, including two reduction reactions (O2→·O2 - and CO2→CO) and three oxidation reactions (H2O→·OH, GSH→GSSG, and LA→PA). These catalytic reactions not only induce immunogenic death in tumor cells through the efficient generation of ROS/CO and the consumption of GSH but also specifically lead to the use of lactic acid (LA) as an electron donor to improve catalytic activity and disrupt the LA-mediated immunosuppressive microenvironment, mediating synergistic catalysis and immunotherapy for orthotopic rectal cancer. Therefore, this optical fiber intervention triggered the combination of heterojunction catalytic therapy and immunotherapy, which exhibits prominent antitumor effects.

Low-dose doxorubicin loaded extracellular vesicles combined Fas/FasL pathway-mediated chemo-sensitization and immunotherapy against tumor

The clinical application of doxorubicin (DOX) is mainly restricted by its serious side effects, poor drug delivery efficiency, and limited immunogenic death (ICD) effect. To improve DOX-based chemotherapy and ameliorate its adverse effects, we utilized 3LL cell-derived extracellular vesicles to encapsulate DOX and sodium nitroprusside (SNP) to obtain DOX/SNP@CM, which could effectively target the tumor site by harnessing the inherent homologous targeting property of tumor cell membranes. DOX performed its role on chemotherapy, and SNP successfully respond to the intracellular GSH to continuously generate nitric oxide (NO). The in situ-produced NO upregulated the Fas expression on the tumor cell surface, thereby sensitizing the Fas/FasL pathway-mediated tumor cell apoptosis of DOX. Furthermore, NO also boosted the intratumoral infiltration of cytotoxic T cells by promoted ICD effect towards tumor cells. Importantly, the anti-tumor immunity tightly cooperated with Fas/FasL mediated tumor cell apoptosis by NO-mediated manipulation on Fas/FasL interaction, collectively making DOX/SNP@CM exert significant tumor growth inhibition with low-dose DOX. Remarkably, DOX and SNP both are widely used clinical medicines, ensuring DOX/SNP@CM a potential opportunity for future practical applications.

Programmable melanoma-targeted radio-immunotherapy via fusogenic liposomes functionalized with multivariate-gated aptamer assemblies

Radio-immunotherapy exploits the immunostimulatory features of ionizing radiation (IR) to enhance antitumor effects and offers emerging opportunities for treating invasive tumor indications such as melanoma. However, insufficient dose deposition and immunosuppressive microenvironment (TME) of solid tumors limit its efficacy. Here we report a programmable sequential therapeutic strategy based on multifunctional fusogenic liposomes (Lip@AUR-ACP-aptPD-L1) to overcome the intrinsic radio-immunotherapeutic resistance of solid tumors. Specifically, fusogenic liposomes are loaded with gold-containing Auranofin (AUR) and inserted with multivariate-gated aptamer assemblies (ACP) and PD-L1 aptamers in the lipid membrane, potentiating melanoma-targeted AUR delivery while transferring ACP onto cell surface through selective membrane fusion. AUR amplifies IR-induced immunogenic death of melanoma cells to release antigens and damage-associated molecular patterns such as adenosine triphosphate (ATP) for triggering adaptive antitumor immunity. AUR-sensitized radiotherapy also upregulates matrix metalloproteinase-2 (MMP-2) expression that combined with released ATP to activate ACP through an “and” logic operation-like process (AND-gate), thus triggering the in-situ release of engineered cytosine-phosphate-guanine aptamer-based immunoadjuvants (eCpG) for stimulating dendritic cell-mediated T cell priming. Furthermore, AUR inhibits tumor-intrinsic vascular endothelial growth factor signaling to suppress infiltration of immunosuppressive cells for fostering an anti-tumorigenic TME. This study offers an approach for solid tumor treatment in the clinics.

Stereotactic ablative radiotherapy combined with fruquintinib and tislelizumab in metastatic colorectal cancer: Updated findings from a single-arm, prospective phase II trial (RIFLE).

e15570 Background: Stereotactic ablative radiotherapy (SABR) has been shown to sensitize immunotherapy through inducing immunogenic death and remodeling the tumor immune microenvironment. In addition, anti-angiogenic therapy exhibits synergistic antitumor effects with PD-1/PD-L1 antibodies through its immunomodulatory effects for metastatic colorectal cancer (mCRC) patients. Here, we report the updated results from RIFLE trial: the efficacy and safety of the combination of fruquintinib, PD-1 inhibitor tislelizumab and SABR in mCRC patients. Methods: This is a single-center, single-arm, prospective phase II clinical trial (NCT04948034). mCRC patients with at least 2 measurable lesions (≥1 of which can be targeted with radiation and ≥1 lesion outside the radiation field) who have failed ≥ 1L standard therapy will receive SABR followed by fruquintinib (5 mg, d1-14, qd) and tislelizumab (200 mg, d1, q3w) within two weeks from completion of radiation. The percentage change from baseline in the sum of longest diameter of target lesions, consist of specified radiated and non-radiated lesions, will be assessed after at least 2 cycles’ drug treatment. Primary endpoint is best objective response rate (ORR) of target lesions. Secondary endpoints include disease control rate (DCR), duration of response (DoR), progression-free survival (PFS) rate, overall survival (OS) rate and toxicity. Results: From August 2021 to February 2024, 34 patients were included in the trial and 31 in the efficacy analysis. Median age was 62 years, 24 (77.4%) patients were male, 26 (83.9%) had ≥ 3 metastases, and 14 (45.2%) had received ≥ 3 prior lines of systemic therapy. The biological effective dose (BED) for irradiated lesions ranged from 37.5 to 105 Gy. Median study follow-up was 17.3 months (95%CI:13.841-20.759), 24 patients were alive and 13 remained on treatment. 1 patient achieved complete response (CR) for target lesions, 8 partial response (PR), 14 stable disease (SD), illustrating an ORR of 29% and a DCR of 74.2%. Median PFS was 8.8 months (95%CI:5.868-11.732). The most common treatment-related adverse events (TRAEs) were proteinuria (35.5%), hypertension (22.6%) and rash (19.4%). Grade 3-4 AEs occurred in 9 patients, including proteinuria and hypertension, and there were no treatment-related deaths. Conclusions: SABR combined with tislelizumab and fruquintinib shows promising effects and good safety in the treatment of metastatic colorectal cancer, which is expected to provide new therapeutic strategies and improve the prognosis for mCRC patients. Clinical trial information: NCT04948034 . [Table: see text]

As1411-modified liposomes to enhance drug utilization and augment the anti-tumor efficacy

BackgroundThe utilization of liposomes in drug delivery has garnered significant attention due to their efficient drug loading capacity and excellent biocompatibility, rendering them a promising platform for tumor therapy. However, the average size of liposomes ~ 100 nm leads to liposomes being susceptible to hepatic and renal metabolism to excretion outside the body leading to poor drug delivery efficiency with a total utilization rate of less than 0.7%, resulting in unfavorable treatment outcomes.ResultsWe have developed a novel liposome platform equipped with tumor surface nucleolin-targeting capacity to enhance drug accumulation at the tumor in vivo. The encapsulation of doxorubicin through thin film hydration has resulted in the formation of D@L-AS1411. Through in vivo experiments, we have demonstrated the effective accumulation of D@L-AS1411 at the tumor site and its ability to improve doxorubicin utilization rates by 40%. Additionally, D@L-AS1411 induces immunogenic death of tumor cells, release of tumor-associated antigens, upregulation of calreticulin expression, and recruitment of active T cell infiltration, and ultimately improves the therapeutic efficacy against tumors (70%).ConclusionsBased on the nucleic acid aptamer AS1411, D@L-1411 is developed to specifically enhance the accumulation of Dox at tumor sites, thereby inhibiting and enhancing the anti-tumor effect. In summary, this study not only provides an efficient tumor-targeting delivery platform but also contributes to the improvement of chemotherapy–immunotherapy combination for tumor treatment strategy in the clinic.

Biomimetic piezoelectric nanomaterial-modified oral microrobots for targeted catalytic and immunotherapy of colorectal cancer.

Lactic acid (LA) accumulation in the tumor microenvironment poses notable challenges to effective tumor immunotherapy. Here, an intelligent tumor treatment microrobot based on the unique physiological structure and metabolic characteristics of Veillonella atypica (VA) is proposed by loading Staphylococcus aureus cell membrane-coating BaTiO3 nanocubes (SAM@BTO) on the surface of VA cells (VA-SAM@BTO) via click chemical reaction. Following oral administration, VA-SAM@BTO accurately targeted orthotopic colorectal cancer through inflammatory targeting of SAM and hypoxic targeting of VA. Under in vitro ultrasonic stimulation, BTO catalyzed two reduction reactions (O2 → •O2- and CO2 → CO) and three oxidation reactions (H2O → •OH, GSH → GSSG, and LA → PA) simultaneously, effectively inducing immunogenic death of tumor cells. BTO catalyzed the oxidative coupling of VA cells metabolized LA, effectively disrupting the immunosuppressive microenvironment, improving dendritic cell maturation and macrophage M1 polarization, and increasing effector T cell proportions while decreasing regulatory T cell numbers, which facilitates synergetic catalysis and immunotherapy.

Biomimetic nanodrug blocks CD73 to inhibit adenosine and boosts antitumor immune response synergically with photothermal stimulation

Combination of tumor immunotherapy with photothermal therapy (PTT) is a feasible tactic to overcome the drawback of immunotherapy such as poor immune response. Via triggering the immunogenic cells death (ICD), PTT can stimulate the activity of immune cells, but meanwhile, the level of adenosine is elevated via the CD73-induced decomposition of ATP which is overexpressed accompanying with the PTT process, resulting in negative feedback to impair the immune stimulation. Herein, we developed a novel biomimetic photothermal nanodrug to specifically block CD73 for inhibition of adenosine production and more efficient priming of the suppressive immune microenvironments. The nanodrug, named as AptEM@CBA, is constructed by encapsulation of photothermal agent black phosphorus quantum dots (BPQDs) and selective CD73 inhibitor α, β-Methyleneadenosine 5′-diphosphate (AMPCP) in chitosan nanogels, which are further covered with aptamer AS1411 modified erythrocyte membrane (EM) for biomimetic camouflage. With AS1411 induced active targeting and EM induced long blood circulation time, the enrichment of the nanodrug tumor sites is promoted. The photothermal treatment promotes the maturation of dendritic cells. Meanwhile, the release of AMPCP suppress the adenosine generation via CD73 blockade, alleviating the impairment of adenosine to dendritic cells and suppressing regulatory T cells, synergically stimulate the activity of T cells. The combination of CD73 blockade with PTT, not only suppresses the growth of primary implanted tumors, but also boosts strong antitumor immunity to inhibit the growth of distal tumors, providing good potential for tumor photoimmunotherapy.

Core-shell nanomedicine based on multifunctional tetrahedral DNA nanostructures for synergistic enhancement of tumor chemodynamic/chemo-immunotherapy

Immune checkpoint blockade therapy has made great strides in cancer treatment, but conventional immune checkpoint blockade antibodies often lead to overactivation of the immune system and severe immune-related adverse effects. Herein, we report the design of a nanomedicine (denoted as CPD@M−TDN) based on multifunctional tetrahedral DNA nanostructures (M−TDN). In this system, a bimetallic metal–organic framework (Cu/ZIF-8) is synthesized as the core; doxorubicin-loaded polydopamine acts as a shell to reduce the immunogenicity of the nanomaterials in peripheral blood. Finally, the CpG oligodeoxynucleotides and PD-L1 aptamer-based M−TDN are coupled to the core–shell structure nanomedicine through the biotin-avidin-system. Under the acidic tumor microenvironment, the decomposition of Cu/ZIF-8 and the release of copper ions and doxorubicin can lead to immunogenic death of tumor cells through chemodynamic/chemotherapy. Furthermore, the M−TDN has the dual effects of weakening the immunosuppressive microenvironment with PD-L1 aptamer and promoting dendritic cell activation with the immunostimulant CpG. Overall, the developed CPD@M−TDN can effectively enhance the response rate to immunotherapy and has excellent potential in the field of integrated tumor treatment.