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Although photothermal therapy (PTT) is effective at killing tumor cells, it can inadvertently damage healthy tissues surrounding the tumor. Nevertheless, lowering the treatment temperature will reduce the therapeutic effectiveness. In this study, we employed 2,2'-((2Z,2'Z)-((4,4,9,9-Tetrahexyl-4,9-dihydro-s-indaceno[1,2-b:5,6-b']dithiophene-2,7-diyl)bis(methanylylidene))bis(3-oxo-2,3-dihydro-1H-indene-2,1-diylidene)) dimalononitrile (IDIC), a molecule possessing a conventional acceptor-donor-acceptor (A-D-A) structure, as a photothermal agent (PTA) to facilitate effective mild photothermal therapy (mPTT). IDIC promotes intramolecular charge transfer under laser irradiation, making it a promising candidate for mPTT. To enhance the therapeutic potential of IDIC, we incorporated quercetin (Qu) into IDIC to form IDIC-Qu nanoparticles (NPs), which can inhibit heat shock protein (HSP) activity during the process of mPTT. Moreover, IDIC-Qu NPs exhibited exceptional water dispersibility and passive targeting abilities towards tumor tissues, attributed to its enhanced permeation and retention (EPR) effect. These advantageous properties position IDIC-Qu NPs as a promising candidate for targeted tumor treatment. Importantly, the IDIC-Qu NPs demonstrated controllable photothermal effects, leading to outstanding in vitro cytotoxicity against cancer cells and effective in vivo tumor ablation through mPTT. IDIC-Qu NPs nano-system enriches the family of organic PTAs and holds significant promise for future clinical applications of mPTT., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Carbon dots (CDs) have garnered significant interest owing to their distinctive optical properties. However, their bioimaging and biomedical applications are limited by pronounced fluorescence (FL) quenching in aqueous media and low tumor accumulation efficacy associated with their ultra-small size. This study proposes a simple surface modification approach using functioning d-arginine on CDs (d-Arg@CDs) to improve their near-infrared (NIR) FL in aqueous solution and maintain their high photothermal conversion properties. Because of the low utilization rate of dextral amino acids in animals, modifying CDs with low molecular weight d-arginine did not increase particle size but extended the metabolism time in blood circulation, thereby leading to enhanced accumulation efficacy at tumor sites in the mice model. The enhanced tumor accumulation of d-Arg@CDs resulted in significantly superior tumor NIR FL imaging and photothermal therapy performance compared with pure CDs and l-arginine functionalized CDs. This dextral amino acid modification approach is expected to be an effective tool for enhancing the biomedical applications of CDs., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Synergistic photothermal/immunotherapy has garnered significant attention for its potential to enhance tumor therapeutic outcomes. However, the fabrication of an intelligent system with a simple composition that simultaneously exerts photothermal/immunotherapy effect and imaging guidance function still remains a challenge. Herein, a glutathione (GSH)-responsive theranostic nanoprobe, named HA-MnO 2 /ICG, was elaborately constructed by loading photothermal agent (PTA) indocyanine green (ICG) onto the surface of hyaluronic acid (HA)-modified manganese dioxide nanosheets (HA-MnO 2 ) for magnetic resonance (MR) imaging-guided synergetic photothermal/immuno-enhanced therapy. In this strategy, HA-MnO 2 nanosheets were triggered by the endogenous GSH in tumor microenvironment to generate Mn 2+ for MR imaging, where the longitudinal relaxation rate of HA-MnO 2 /ICG was up to 14.97 mM -1 s -1 (∼24 times than that found in a natural environment), demonstrating excellent intratumoral MR imaging. Moreover, the HA-MnO 2 /ICG nanoprobe demonstrates remarkable photothermal therapy (PTT) efficacy, generating sufficient heat to induce immunogenic cell death (ICD) within tumor cells. Meanwhile the released Mn 2+ ions from the nanosheets function as potent immune adjuvants, amplifying the immune response against cancer. In vivo experiments validated that HA-MnO 2 /ICG-mediated PTT was highly effective in eradicating primary tumors, while simultaneously enhancing immunogenicity to prevent the growth of distal metastasis. This hybrid HA-MnO 2 /ICG nanoprobe opened new avenues in the design of MR imaging-monitored PTT/immuno-enhanced synergistic therapy for advanced cancer., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Photothermal therapy combined with chemotherapy has shown great promise in the treatment of cancer. In this synergistic system, a safe, stable, and efficient photothermal agent is desired. Herein, an effective photothermal agent, carbon quantum dots (CQDs), was initially synthesized and then rationally constructed a folic acid (FA)-targeted photothermal multifunctional nanoplatform by encapsulating CQDs and the anticancer drug doxorubicin (DOX) in the liposomes. Indocyanine green (ICG), a near infrared (NIR) photothermal agent, approved by the U.S. Food and Drug Administration, was embedded in the bilayer membrane to further enhance the photothermal effects and facilitate the rapid cleavage of liposomes for drug release. Triggered by the NIR laser, this engineered photothermal multifunctional nanoplatform, not only exhibited an excellent performance with the photothermal conversion efficiency of up to 47.14%, but also achieved controlled release of the payloads. In vitro, and in vivo experiments demonstrated that the photothermal multifunctional nanoplatform had excellent biocompatibility, enhanced tumor-specific targeting, stimuli-responsive drug release, effective cancer cell killing and tumor suppression through multi-modal synergistic therapy. The successful construction of this NIR light-triggered targeted photothermal multifunctional nanoplatform will provide a promising strategy for the design and development of synergistic chemo-photothermal combination therapy and improve the therapeutic efficacy of cancer treatment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Photothermal therapy (PTT) offers significant potential in cancer treatment due to its short, simple, and less harmful nature. However, obtaining a photothermal agent (PTA) with good photothermal performance and biocompatibility remains a challenge. MXenes, which are PTAs, have shown promising results in cancer treatment. This study presents the preparation of Ti 3 C 2 MXene quantum dots (MXene QDs) using a simple hydrothermal and ultrasonic method and their use as a PTA for cancer treatment. Compared to conventional MXene QDs synthesized using only the hydrothermal method, the ultrasonic process increased the degree of oxidation on the surface of the MXene QDs. This resulted in the presence of more hydrophilic groups such as hydroxyl groups on the MXene QD surfaces, leading to excellent dispersion in the aqueous system and biocompatibility of the prepared MXene QDs without the need for surface modification. The MXene QDs showed great photothermal performance with a photothermal conversion efficiency of 62.5%, resulting in the highest photothermal conversion efficiency among similar materials reported thus far. Both in vitro and in vivo experiments have proved the potent tumor inhibitory effect of the MXene QD-mediated PTT, with minimal harm to mice. Therefore, these MXene QDs hold a significant promise for clinical applications.

Viral vectors are being used for the treatment of cancer. Yet, their efficacy varies among tumors and their use poses challenges in immunosuppressed patients, underscoring the need for alternatives. We report striking antitumoral effects by a nonlytic viral vector based on attenuated lymphocytic choriomeningitis virus (r3LCMV). We show in multiple tumor models that injection of tumor-bearing mice with this vector results in improved tumor control and survival. Importantly, r3LCMV improved tumor control in immunodeficient Rag1-/- mice and MyD88-/- mice, suggesting that multiple pathways contributed to the antitumoral effects. The antitumoral effects of r3LCMV were also observed when this vector was administered several weeks before tumor challenges, suggesting the induction of trained immunity. Single-cell RNA sequencing analyses, antibody blockade experiments, and knockout models revealed a critical role for host-intrinsic IFN-I in the antitumoral efficacy of r3LCMV vectors. Collectively, these data demonstrate potent antitumoral effects by r3LCMV vectors and unveil multiple mechanisms underlying their antitumoral efficacy.

Objective: In order to ensure the stable transcription of target genes, we constructed a eukaryotic high expression vector carrying an immune-check inhibitor PD-1v and a variety of cytokines, and studied their effects on activating immune response to inhibit tumor growth., Methods: A novel eukaryotic expression plasmid vector named pT7AMPCE containing T7RNA polymerase, T7 promoter, internal ribosome entry site (IRES), and poly A tailing signal was constructed by T4 DNA ligase, on which homologous recombination was used to clone and construct the vector carrying PD-1v, IL-2/15, IL-12, GM-CSF, and GFP. In vitro transfection of CT26 cells was performed, and the protein expression of PD-1v, IL-12 and GM-CSF was detected by Western blot and ELISA after 48 h. Mice were subcutaneously inoculated with CT26-IRFP tumor cells in the rib abdomen, and the tumor tissues were injected with PD-1v, IL-2/15, IL-12, and GM-CSF recombinant plasmids for treatment during the experimental period. The efficacy of the treatment was evaluated by assay tumor size and survival time of tumor-bearing mice during the experiment. Expression levels of IFN-γ, TNF, IL-4, IL-2, and IL-5 in mouse blood were measured using the CBA method. Tumor tissues were extracted and immune cell infiltration in tumor tissues was detected by HE staining and the IHC method., Results: The recombinant plasmids carrying PD-1v, IL-2/15, IL-12, and GM-CSF were successfully constructed, and the Western blot and ELISA results showed that PD-1v, IL-12, and GM-CSF were expressed in the supernatant of CT26 cells 48 h after in vitro cell transfection. The combined application of PD-1v, IL-2/15, IL-12, and GM-CSF recombinant plasmids significantly inhibited tumor growth in mice, and the tumor growth rate was significantly lower than that in the blank control group and GFP plasmid control group (p < 0.05). Cytometric bead array data suggested that the combination of PD-1v and various cytokines can effectively activate immune cells. HE and IHC analysis revealed plenty of immune cell infiltrates in the tumor tissue, and a large proportion of tumor cells showed the necrotic phenotype in the combination treatment group., Conclusion: The combination of immune check blockade and multiple cytokine therapy can significantly activate the body's immune response and inhibit tumor growth., (© 2023 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.)

To date, no immunotherapy approaches have managed to fully overcome T-cell exhaustion, which remains a mandatory fate for chronically activated effector cells and a major therapeutic challenge. Understanding how to reprogram CD8 + tumor-infiltrating lymphocytes away from exhausted effector states remains an elusive goal. Our work provides evidence that orthogonal gene engineering of T cells to secrete an interleukin (IL)-2 variant binding the IL-2Rβγ receptor and the alarmin IL-33 reprogrammed adoptively transferred T cells to acquire a novel, synthetic effector state, which deviated from canonical exhaustion and displayed superior effector functions. These cells successfully overcame homeostatic barriers in the host and led-in the absence of lymphodepletion or exogenous cytokine support-to high levels of engraftment and tumor regression. Our work unlocks a new opportunity of rationally engineering synthetic CD8 + T-cell states endowed with the ability to avoid exhaustion and control advanced solid tumors., (© 2023. The Author(s).)

Clostridium ghonii (C. ghonii) is a non-pathogenic Clostridium species and a strictly anaerobic, spore-forming bacterium. However, its bacterial oncolytic capabilities and applications have not yet been reported. This study aimed to determining the bacterial oncolytic capability of C. ghonii for the treatment of experimental solid tumors. C. ghonii secreted collagenase IV and phospholipase c and significantly promoted apoptosis and necrosis in cultured A549 cells. C. ghonii spores specially germinated and were distributed in the tumors, and elicited the immune responses after intratumoral injection in tumor-bearing mice. C. ghonii spores decreased tumor volumes and increased tumor necrosis and inhibition rates in tumor-bearing mice. Furthermore, the combination of radiation and C. ghonii exerted additive anti-tumor effects. Taken together, our data indicate that C. ghonii is a bacteriolytic therapeutic agent against solid tumors. Given the proven natural safety of C. ghonii, it is attractive as a potential novel bacteriolytic therapy for solid tumors., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Inc. All rights reserved.)

CpG, an agonist of toll-like receptor 9 (TLR9), has become a novel adjuvant that substantially potentiates cellular immunity. However, this agonist may increase systemic toxicity by diffusing into blood after administration and is difficult to be internalized by immune cells to reach TLR9 located in endosomes as a result of the characteristics of negative charge of CpG. Here, we applied a scalable and controllable flash nanocomplexation technology to prepare nanoparticulate CpG adjuvant ( np CpG), CpG encapsulated in a physical cross-linking network of protamine and TPP. The nanoadjuvant could redirect CpG into draining lymph nodes to reduce systemic diffusion to improve safety. Further, a combination of np CpG and influenza H1N1 hemagglutinin antigen showed excellent humoral and cellular immunity, evoking high levels of antibodies and cytokines and inducing a great expansion of splenocytes in immunized mice. Also, the nanoadjuvant combined with ovalbumin antigen led to a potent cytotoxic T-cell response, substantially inhibited tumor growth, and improved the survival rate of mice in a melanoma model. This study showed the universal performances of np CpG in infectious disease prevention and tumor immunotherapy to demonstrate the translational potential.

Aim: To study the antitumor and antimetastatic effects of B. subtilis IMV B-7724 lectin used in neoadjuvant and adjuvant settings in vivo., Materials and Methods: Studies were performed on C57Bl/6J mice; Lewis lung carcinoma (LLC) was used as an experimental tumor. В. subtilis ІМV В-7724 lectin was administered to tumor-bearing mice or to mice which underwent surgical resection of the primary tumor. The lectin was injected subcutaneously, 10 times, at a single dose of 5 or 1 mg/kg of body weight. The standard indicators of tumor growth and metastasis were evaluated., Results: Independently of the application settings, the lectin at a dose of 1 mg/kg of b.w. caused more pronounced effect than at a dose of 5 mg/kg of b.w. The administration of B. subtilis IMV B-7724 lectin to the mice with LLC in neoadjuvant setting did not cause notable antitumor effect but led to a significant decrease in the number and volume of lung metastases. The lectin administration in adjuvant setting significantly inhibited metastasis: the metastasis inhibition index reached 63.0% and 100% in the mice treated with the lectin at a dose of 5 mg/kg and 1 mg/kg respectively. The mean survival time of the treated animals significantly increased., Conclusion: A pronounced antimetastatic effect of B. subtilis IMV B-7724 lectin administered in an adjuvant setting was demonstrated.

Schwannomas are slow-growing benign neoplasms that develop throughout the body causing pain, sensory/motor dysfunction, and death. Because bacterial immunotherapy has been used in the treatment of some malignant neoplasms, we evaluated attenuated Salmonella typhimurium strains as immunotherapies for benign murine schwannomas. Several bacterial strains were tested, including VNP20009, a highly attenuated strain that was previously shown to be safe in human subjects with advanced malignant neoplasms, and a VNP20009 mutant that was altered in motility and other properties that included adherence and invasion of cultured mammalian cells. VNP20009 controlled tumor growth in two murine schwannoma models and induced changes in cytokine and immune effector cell profiles that were consistent with induction of enhanced innate and adaptive host immune responses compared with controls. Intratumoral (i.t.) injection of S. typhimurium led to tumor cell apoptosis, decreased tumor angiogenesis, and lower growth of the injected schwannoma tumors. Invasive VNP20009 was significantly more efficacious than was a noninvasive derivative in controlling the growth of injected tumors. Bacterial treatment apparently induced systemic antitumor immunity in that the growth of rechallenge schwannomas implanted following primary bacterial treatment was also reduced. Checkpoint programmed death-1 (PD-1) blockade induced by systemic administration of anti-PD-1 antibodies controlled tumor growth to the same degree as i.t. injection of S. typhimurium , and together, these two therapies had an additive effect on suppressing schwannoma growth. These experiments represent validation of a bacterial therapy for a benign neoplasm and support development of S. typhimurium VNP20009, potentially in combination with PD-1 inhibition, as a schwannoma immunotherapy.

Low levels of immune infiltrates in the tumor milieu hinder the effectiveness of immunotherapy against immune-cold tumors. In the current work, a tumor-targeting drug delivery system composed of Endo-loaded platelets (Endo@PLT) was developed to relieve immunosuppression by achieving tumor vascular normalization. Endo@PLT reprogrammed the immunostimulatory phenotype, achieving excellent PD-1 immunotherapy in vivo .

T cells survival, proliferation, and anti-tumor response are closely linked to their mitochondrial health. Complement C1q binding protein (C1QBP) promotes mitochondrial fitness through regulation of mitochondrial metabolism and morphology. However, whether C1QBP regulates T cell survival, proliferation, and anti-tumor immune function remains unclear. Our data demonstrated that C1QBP knockdown induced the accumulation of reactive oxygen species (ROS) and the loss of mitochondrial membrane potential to impair T cell mitochondrial fitness. At the same time, C1QBP insufficiency reduced the recruitment of the anti-apoptotic proteins, including Bcl-2 and Bcl-XL, and repressed caspase-3 activation and poly (ADP-ribose) polymerase cleavage, which consequently accelerated the T cell apoptotic process. In contrast, C1QBP knockdown rendered T cells with relatively weaker proliferation due to the inhibition of AKT/mTOR signaling pathway. To investigate the exact role of C1QBP in anti-tumor response, C1QBP +/- and C1QBP +/+ mice were given a subcutaneous injection of murine MC38 cells. We found that C1QBP deficiency attenuated T cell tumor infiltration and aggravated tumor-infiltrating T lymphocytes (TIL) exhaustion. Moreover, we further clarified the potential function of C1QBP in chimeric antigen receptor (CAR) T cell immunotherapy. Our data showed that C1QBP +/- CAR T cells exhibited relatively weaker anti-tumor response than the corresponding C1QBP +/+ CAR T cells. Given that C1QBP knockdown impairs T cells' anti-apoptotic capacity, proliferation as well as anti-tumor immune function, development of the strategy for potentiation of T cells' mitochondrial fitness through C1QBP could potentially optimize the efficacy of the related immunotherapy., (© 2022 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.)

NY-ESO-1 is a cancer/testis antigen expressed in various cancer types. However, the induction of NY-ESO-1-specific CTLs through vaccines is somewhat difficult. Thus, we developed a new type of artificial adjuvant vector cell (aAVC-NY-ESO-1) expressing a CD1d-NKT cell ligand complex and a tumor-associated antigen, NY-ESO-1. First, we determined the activation of invariant natural killer T (iNKT) and natural killer (NK) cell responses by aAVC-NY-ESO-1. We then showed that the NY-ESO-1-specific CTL response was successfully elicited through aAVC-NY-ESO-1 therapy. After injection of aAVC-NY-ESO-1, we found that dendritic cells (DCs) in situ expressed high levels of costimulatory molecules and produced interleukn-12 (IL-12), indicating that DCs undergo maturation in vivo. Furthermore, the NY-ESO-1 antigen from aAVC-NY-ESO-1 was delivered to the DCs in vivo, and it was presented on MHC class I molecules. The cross-presentation of the NY-ESO-1 antigen was absent in conventional DC-deficient mice, suggesting a host DC-mediated CTL response. Thus, this strategy helps generate sufficient CD8 + NY-ESO-1-specific CTLs along with iNKT and NK cell activation, resulting in a strong antitumor effect. Furthermore, we established a human DC-transferred NOD/Shi-scid/IL-2γc null immunodeficient mouse model and showed that the NY-ESO-1 antigen from aAVC-NY-ESO-1 was cross-presented to antigen-specific CTLs through human DCs. Taken together, these data suggest that aAVC-NY-ESO-1 has potential for harnessing innate and adaptive immunity against NY-ESO-1-expressing malignancies., (© 2022 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.)

Lysine-specific demethylase 6A (KDM6A), also named UTX, is frequently mutated in bladder cancer (BCa). Although known as a tumor suppressor, KDM6A's therapeutic potential in the metastasis of BCa remains elusive. It also remains difficult to fulfill the effective up-regulation of KDM6A levels in bladder tumor tissues in situ to verify its potential in treating BCa metastasis. Here, we report a mucoadhesive messenger RNA (mRNA) nanoparticle (NP) strategy for the intravesical delivery of KDM6A -mRNA in mice bearing orthotopic Kdm6a -null BCa and show evidence of KDM6A's therapeutic potential in inhibiting the metastasis of BCa. Through this mucoadhesive mRNA NP strategy, the exposure of KDM6A -mRNA to the in situ BCa tumors can be greatly prolonged for effective expression, and the penetration can be also enhanced by adhering to the bladder for sustained delivery. This mRNA NP strategy is also demonstrated to be effective for combination cancer therapy with other clinically approved drugs (e.g., elemene), which could further enhance therapeutic outcomes. Our findings not only report intravesical delivery of mRNA via a mucoadhesive mRNA NP strategy but also provide the proof-of-concept for the usefulness of these mRNA NPs as tools in both mechanistic understanding and translational study of bladder-related diseases., Competing Interests: The authors declare no competing interest., (Copyright © 2022 the Author(s). Published by PNAS.)

Metastatic osteosarcoma has a poor prognosis with a 2-y, event-free survival rate of ∼15 to 20%, highlighting the need for the advancement of efficacious therapeutics. Chimeric antigen receptor (CAR) T-cell therapy is a potent strategy for eliminating tumors by harnessing the immune system. However, clinical trials with CAR T cells in solid tumors have encountered significant challenges and have not yet demonstrated convincing evidence of efficacy for a large number of patients. A major bottleneck for the success of CAR T-cell therapy is our inability to monitor the accumulation of the CAR T cells in the tumor with clinical-imaging techniques. To address this, we developed a clinically translatable approach for labeling CAR T cells with iron oxide nanoparticles, which enabled the noninvasive detection of the iron-labeled T cells with magnetic resonance imaging (MRI), photoacoustic imaging (PAT), and magnetic particle imaging (MPI). Using a custom-made microfluidics device for T-cell labeling by mechanoporation, we achieved significant nanoparticle uptake in the CAR T cells, while preserving T-cell proliferation, viability, and function. Multimodal MRI, PAT, and MPI demonstrated homing of the T cells to osteosarcomas and off-target sites in animals administered with T cells labeled with the iron oxide nanoparticles, while T cells were not visualized in animals infused with unlabeled cells. This study details the successful labeling of CAR T cells with ferumoxytol, thereby paving the way for monitoring CAR T cells in solid tumors., Competing Interests: Competing interest statement: R.G.M. is a consultant for Lyell Immunopharma, Illumina Radiopharmaceuticals, and GammaDelta Therapeutics. T.S. is a cofounder of CellFE and a consultant for Heat Bio., (Copyright © 2022 the Author(s). Published by PNAS.)

PD-1 signaling on T cells is the major pathway that limits T cell immunity, but the efficacy of anti-PD-1 therapy has been limited to a small proportion of patients with advanced cancers. We fortuitously observed that anti-PD-1 therapy depends on IL-2 signaling, which raises the possibility that a lack of IL-2 limits anti-PD-1-induced effector T cell expansion. To selectively deliver IL-2 to PD-1+CD8+ tumor-infiltrating lymphocytes (TILs), we engineered a low-affinity IL-2 paired with anti-PD-1 (PD-1-laIL-2), which reduced affinity to peripheral Treg cells but enhanced avidity to PD-1+CD8+ TILs. PD-1-laIL-2 exerted better tumor control and lower toxicity than single or mixed treatments. Mechanistically, PD-1-laIL-2 could effectively expand dysfunctional and tumor-specific CD8+ T cells. Furthermore, we discovered that presumably dysfunctional PD-1+TIM3+ TILs are the dominant tumor-specific T cells responding to PD-1-laIL-2. Collectively, these results highlight that PD-1-laIL-2 can target and reactivate tumor-specific TILs for tumor regression as a unique strategy with stronger efficacy and lower toxicity.

Ecto-nucleotide pyrophosphatase/phosphodiesterases 1 (ENPP1 or NPP1), is an attractive therapeutic target for various diseases, primarily cancer and mineralization disorders. The ecto-enzyme is located on the cell surface and has been implicated in the control of extracellular levels of nucleotide, nucleoside and (di) phosphate. Recently, it has emerged as a critical phosphodiesterase that hydrolyzes cyclic 2'3'- cGAMP, the endogenous ligand for STING (STimulator of INterferon Genes). STING plays an important role in innate immunity by activating type I interferon in response to cytosolic 2'3'-cGAMP. ENPP1 negatively regulates the STING pathway and hence its inhibition makes it an attractive therapeutic target for cancer immunotherapy. Herein, we describe the design, optimization and biological evaluation studies of a series of novel non-nucleotidic thioguanine based small molecule inhibitors of ENPP1. The lead compound 43 has shown good in vitro potency, stability in SGF/SIF/PBS, selectivity, ADME properties and pharmacokinetic profile and finally potent anti-tumor response in vivo. These compounds are a good starting point for the development of potentially effective cancer immunotherapy agents., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Nanomedicine, constructed from therapeutics, presents an advantage in drug delivery for cancer therapies. However, nanocarrier-based treatment systems have problems such as interbatch variability, multicomponent complexity, poor drug delivery, and carrier-related toxicity. To solve these issues, the natural molecule honokiol (HK), an anticancer agent in a phase I clinical trial (CTR20170822), was used to form a self-assembly nanoparticle (SA) through hydrogen bonding and hydrophobicity. The preparation of SA needs no molecular precursors or excipients in aqueous solution, and 100% drug-loaded SA exhibited superior tumor-targeting ability due to the enhanced permeability and retention (EPR) effect. Moreover, SA significantly enhanced the antitumor immunity relative to free HK, and the mechanism has notable selectivity to the p53 pathway. Furthermore, SA exhibited excellent physiological stability and inappreciable toxicity. Taken together, this supramolecular self-assembly strategy provides a safe and "molecular economy" model for rational design of clinical therapies and is expected to promote targeted therapy of HK, especially in colorectal cancer patients with obvious p53 status.

Herein we report synthesis of hematite (α-Fe 2 O 3 ) nanorods by calcinating hydrothermally synthesized goethite nanorods at 5000C. The structural, optical and MRI imaging guided cancer therapeutic properties of fabricated nanorods have been discussed in this manscript. FESEM and TEM imaging techniques were used to confirm the nanorod like morphology of as prepared materials. As we know that Fe 2 O 3 nanorods with size in the range of 25-30 nm exhibit super magnetism. After coating with the PEG, the as prepared nanorods can be used as T 2 MR imaging contrast agents. An excellent T 2 MRI contrast of 38.763 mM -1 s -1 achieved which is highest reported so far for α-Fe 2 O 3 . Besides the as prepared nanorods display an excellent photothermal conversion efficiency of 39.5% thus acts as an excellent photothermal therapeutic agent. Thus, we envision the idea of testing our nanorods for photothermal therapy and MR imaging application both in vitro and in vivo, achieving an excellent T 2 MRI contrast and photothermal therapy effect with as prepared PEGylated nanorods., (© 2021. The Author(s).)

Trastuzumab combined with chemotherapy is the first-line treatment for advanced HER2-positive gastric cancer, but it still suffers from limited therapeutic efficiency and serious side effects, which are usually due to the poor delivery efficiency and the drug resistance of tumor cells to the chemotherapeutic drugs. Herein, a type of ultrasound microbubble for simultaneous delivery of sonosensitizers and therapeutic antibodies to achieve targeting combination of sonodynamic therapy and antibody therapy of HER2-positive gastric cancer was constructed from pyropheophorbide-lipid followed by trastuzumab conjugation (TP MBs). In vitro and in vivo studies showed that TP MBs had good biological safety, and their in vivo delivery can be monitored by ultrasound/fluorescence bimodal imaging. With ultrasound (US) located at the tumor area, TP MBs can be converted into nanoparticles (TP NPs) in situ by US-targeted microbubble destruction; plus the enhanced permeability and retention effects and the targeting effects of trastuzumab, the enrichment of sonosensitizers and antibodies in the tumor tissue can be greatly enhanced (∼2.1 times). When combined with ultrasound, TP MBs can not only increase the uptake of sonosensitizers in HER2-positive gastric cancer NCI-N87 cells but also efficiently generate singlet oxygen to greatly increase the killing effect on cells, obviously inhibiting the tumor growth in HER2-positive gastric cancer NCI-N87 cell models with a tumor inhibition rate up to 79.3%. Overall, TP MBs combined with US provided an efficient way for co-delivery of sonosensitizers and antibodies, greatly enhancing the synergistic therapeutic effect on HER2-positive gastric cancer while effectively reducing the side effects.

Theranostic agents for concurrent cancer therapy and diagnosis have begun attracting attention as a promising modality. However, accurate imaging and identification remains a great challenge for theranostic agents. Here, we designed and synthesized a novel theranostic agent H6M based on the "double-locked" strategy by introducing an electron-withdrawing nitro group into 1-position of a pH-responsive 3-amino-β-carboline and further covalently linking the hydroxamic acid group, a zinc-binding group (ZBG), to the 3-position of β-carboline to obtain histone deacetylase (HDAC) inhibitory effect for combined HDAC-targeted therapy. We found that H6M can be specifically reduced under overexpressed nitroreductase (NTR) to produce H6AQ , which emits bright fluorescence at low pH. Notably, H6M demonstrated a selective fluorescence imaging via successive reactions with NTR (first "key") and pH (second "key"), and precisely identified tumor margins with a high S/N ratio to guide tumor resection. Finally, H6M exerted robust HDAC1/cancer cell inhibitory activities compared with a known HDAC inhibitor SAHA. Therefore, the NTR/pH-activated theranostic agent provided a novel tool for precise diagnosis and efficient tumor therapy.

Brain metastases are a leading cause of death in patients with breast cancer. The lack of clinical trials and the presence of the blood-brain barrier limit therapeutic options. Furthermore, overexpression of the human epidermal growth factor receptor 2 (HER2) increases the incidence of breast cancer brain metastases (BCBM). HER2-targeting agents, such as the monoclonal antibodies trastuzumab and pertuzumab, improved outcomes in patients with breast cancer and extracranial metastases. However, continued BCBM progression in breast cancer patients highlighted the need for novel and effective targeted therapies against intracranial metastases. In this study, we engineered the highly migratory and brain tumor tropic human neural stem cells (NSCs) LM008 to continuously secrete high amounts of functional, stable, full-length antibodies against HER2 (anti-HER2Ab) without compromising the stemness of LM008 cells. The secreted anti-HER2Ab impaired tumor cell proliferation in vitro in HER2+ BCBM cells by inhibiting the PI3K-Akt signaling pathway and resulted in a significant benefit when injected in intracranial xenograft models. In addition, dual HER2 blockade using anti-HER2Ab LM008 NSCs and the tyrosine kinase inhibitor tucatinib significantly improved the survival of mice in a clinically relevant model of multiple HER2+ BCBM. These findings provide compelling evidence for the use of HER2Ab-secreting LM008 NSCs in combination with tucatinib as a promising therapeutic regimen for patients with HER2+ BCBM., Competing Interests: The authors declare no competing interest., (Copyright © 2021 the Author(s). Published by PNAS.)

High fluence low-level laser (HF-LLL), a mitochondria-targeted tumour phototherapy, results in oxidative damage and apoptosis of tumour cells, as well as damage to normal tissue. To circumvent this, the therapeutic effect of low fluence LLL (LFL), a non-invasive and drug-free therapeutic strategy, was identified for tumours and the underlying molecular mechanisms were investigated. We observed that LFL enhanced antigen-specific immune response of macrophages and dendritic cells by upregulating MHC class II, which was induced by mitochondrial reactive oxygen species (ROS)-activated signalling, suppressing tumour growth in both CD11c-DTR and C57BL/6 mice. Mechanistically, LFL upregulated MHC class II in an MHC class II transactivator (CIITA)-dependent manner. LFL-activated protein kinase C (PKC) promoted the nuclear translocation of CIITA, as inhibition of PKC attenuated the DNA-binding efficiency of CIITA to MHC class II promoter. CIITA mRNA and protein expression also improved after LFL treatment, characterised by direct binding of Src and STAT1, and subsequent activation of STAT1. Notably, scavenging of ROS downregulated LFL-induced Src and PKC activation and antagonised the effects of LFL treatment. Thus, LFL treatment altered the adaptive immune response via the mitochondrial ROS-activated signalling pathway to control the progress of neoplastic disease., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Radiation is an integral part of cancer therapy. With the emergence of oncolytic vaccinia virus immunotherapy, it is important to study the combination of radiation and vaccinia virus in cancer therapy. In this study, we investigated the anti-tumor effect of and immune mechanisms underlying the combination of high-dose hypofractionated stereotactic body radiotherapy (SBRT) and oncolytic vaccinia virus in preclinical murine models. The combination enhanced the in vivo anti-tumor effect and increased the numbers of splenic CD4 + Ki-67 + helper T lymphocytes and CD8 + Ki-67 + cytotoxic T lymphocytes. Combinational therapy also increased tumor-infiltrating CD3 + CD4 + helper T lymphocytes and CD3 + CD8 + cytotoxic T lymphocytes, but decreased tumor-infiltrating regulatory T cells. In addition, SBRT combined with oncolytic vaccinia virus enhanced in vitro cell death, partly through necroptosis, and subsequent release of damage-associated molecular patterns (DAMPs), and shifted the macrophage M1/M2 ratio. We concluded that SBRT combined with oncolytic vaccinia virus can trigger tumor cell necroptosis and modify macrophages through the release of DAMPs, and then generate potent anti-tumor immunity and effects. Thus, combined therapy is potentially an important strategy for clinical cancer therapy., (Copyright © 2021. Published by Elsevier B.V.)

Combination therapy has been widely studied due to its promising applications in tumor therapy. However, a sophisticated nanoplatform and sequential irradiation with different laser sources for phototherapy complicate the treatment process. Unlike the integration of therapeutic agents, we report a FeS 2 @SRF@BSA nanoplatform for the combination of chemo-combined photothermal therapy (PTT) enhanced photodynamic therapy (PDT) and chemodynamic therapy (CDT) to achieve an "all-in-one" therapeutic agent. Ultrasmall FeS 2 nanoparticles (NPs) with a size of 7 nm exhibited higher Fenton reaction rates due to their large specific surface areas. A photodynamic reaction could be triggered and could generate 1 O 2 to achieve PDT under 808 nm irradiation. FeS 2 NPs also exhibited the desired photothermal properties under the same wavelength of the laser. The Fenton reaction and photodynamic reaction were both significantly improved to accumulate more reactive oxygen species (ROS) with an increase of temperature under laser irradiation. Besides, loading of the chemotherapeutic drug sorafenib (SRF) further improved the efficacy of tumor treatment. To realize long blood circulation, bovine serum albumin (BSA) was used as a carrier to encapsulate FeS 2 NPs and SRF, remarkably improving the biocompatibility and tumor enrichment ability of the nanomaterials. Additionally, the tumors on mice treated with FeS 2 @SRF@BSA almost disappeared under 808 nm irradiation. To sum up, FeS 2 @SRF@BSA NPs possess good biocompatibility, stability, and sufficient therapeutic efficacy in combination therapy for cancer treatment. Our study pointed out a smart design of the nanoplatform as a multifunctional therapeutic agent for combination cancer therapy in the near future.

Antibodies targeting costimulatory receptors of T cells have been developed for the activation of T cell immunity in cancer immunotherapy. However, costimulatory molecule expression is often lacking in tumor-infiltrating immune cells, which can impede antibody-mediated immunotherapy. Here, we hypothesize that delivery of costimulatory receptor mRNA to tumor-infiltrating T cells will enhance the antitumor effects of antibodies. We first design a library of biomimetic nanoparticles and find that phospholipid nanoparticles (PL1) effectively deliver costimulatory receptor mRNA (CD137 or OX40) to T cells. Then, we demonstrate that the combination of PL1-OX40 mRNA and anti-OX40 antibody exhibits significantly improved antitumor activity compared to anti-OX40 antibody alone in multiple tumor models. This treatment regimen results in a 60% complete response rate in the A20 tumor model, with these mice being resistant to rechallenge by A20 tumor cells. Additionally, the combination of PL1-OX40 mRNA and anti-OX40 antibody significantly boosts the antitumor immune response to anti-PD-1 + anti-CTLA-4 antibodies in the B16F10 tumor model. This study supports the concept of delivering mRNA encoding costimulatory receptors in combination with the corresponding agonistic antibody as a strategy to enhance cancer immunotherapy., (© 2021. The Author(s).)

Because of the blood-brain barrier and the high infiltration of glioma cells, the diagnostic accuracy and treatment efficiency of gliomas are still facing challenges. There is an urgent need to explore the integration of diagnostic and therapeutic methods to achieve an accurate diagnosis, guide surgery, and inhibit postoperative recurrence. In this work, we developed a macrophage loaded with a photothermal nanoprobe (MFe 3 O 4 -Cy5.5), which is able to cross the blood-brain barrier and accumulate into deep gliomas to achieve multimodal imaging and guided glioma surgery purposes. With desirable probing depth and high signal-to-noise ratio, Fe 3 O 4 -Cy5.5 can perform fluorescence, photoacoustic, and magnetic resonance imaging, which can distinguish brain tumors from the surrounding normal tissues and accurately guide glioma resection. Meanwhile, Fe 3 O 4 -Cy5.5 can effectively induce local photothermal therapy and inhibit the recurrence of glioma after surgery. These results demonstrate that the macrophage-mediated Fe 3 O 4 -Cy5.5, which can achieve a multimodal diagnosis, accurate imaging-guided surgery, and effective photothermal therapy, is a promising nanoplatform for gliomas.

We aim to evaluate the efficacies of combination therapy with low-frequency ultrasound-stimulated microbubbles (USMB) and radiofrequency ablation (RFA) on suppressing the proliferation of pancreatic cancer cell and treating Panc02 subcutaneous xenograft mice. The proliferation of HPDE6-C7 and Panc02 cells after the treatment of USMB and RFA alone or combination were evaluated by CCK-8 assay. Scratch test was performed to assess the cell migration capability. Panc02-bearing mice were received 14-day treatment of USMB and RFA alone or combination. Tumor size and survival rate were recorded once two days. The serum levels of immune-related factors and changes of apoptosis- and autophagy-related factors were detected by ELISA and western blotting methods. As a result, CKK-8 assays revealed significant inhibition on Panc02 cell proliferation in combination therapy with USMB and RFA relative to other groups (all p < 0.05). Strong synergistic effect of USMB combined with RFA was confirmed via the calculated combination index (CI) <0.4. In addition, combination therapy of USMB and RFA significantly inhibited the migration of Panc02 cells. Moreover, combined treatment remarkably inhibited the size and width of xenograft and improved the survival in Panc02-bearing mice. Furthermore, 14-day combination therapy of USMB and RFA in Panc02-bearing mice significantly facilitated the apoptosis and autophagy of tumor cells. In summary, combination therapy of USMB and RFA showed synergistic anti-tumor efficacies on Panc02 cells attributing to the promotion on apoptosis and autophagy in Panc02 subcutaneous xenograft mice.

Aims: Human papillomavirus (HPV) L1, L2 and E7 proteins were used as target antigens for development of preventive and therapeutic vaccines. Moreover, linkage of antigens to heat shock proteins (HSPs) could enhance the potency of vaccines. Curcumin and nanocurcumin compounds were suggested as the chemopreventive and chemotherapeutic agents against cancer. In this study, two multiepitope DNA and peptide-based vaccine constructs (L1-L2-E7 and HSP70-L1-L2-E7) were used along with curcumin and nanocurcumin to evaluate immune responses, and protective/therapeutic effects in tumor mouse model., Main Methods: At first, the multiepitope L1-L2-E7 and HSP70-L1-L2-E7 fusion genes were subcloned in eukaryotic and prokaryotic expression vectors. The recombinant multiepitope peptides were generated in E. coli strain. Then, the cytotoxic effects of curcumin and nanocurcumin were evaluated on HEK-293 T non-cancerous and C3 cancerous cells. Finally, mice vaccination was performed using different regimens. Curcumin and nanocurcumin compounds were administered alone or along with different vaccine constructs., Key Findings: Our data indicated that the use of nanocurcumin along with the multiepitope HSP70-L1-L2-E7 vaccine construct could completely protect mice against HPV-related C3 tumor cells, and eradicate tumors in a therapeutic test. Furthermore, nanocurcumin showed higher protection than curcumin alone. Generally, curcumin and nanocurcumin compounds could reduce tumor growth synergistically with the multiepitope vaccine constructs, but they did not influence the immune responses in different regimens., Significance: These data demonstrated that the designed multiepitope vaccine constructs along with curcumin and nanocurcumin can be used as a promising method for HPV vaccine development., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Cancer is one of the leading causes of death in the world. A cancer-targeted multifunctional probe labeled with the radionuclide has been developed to provide multi-modalities for NIR fluorescence and nuclear imaging (PET, SPECT), for photothermal therapy (PTT), and targeted radionuclide therapy of cancer. In this study, synthesis, characterization, in vitro, and in vivo biological evaluation of the cyanine-based probe (DOTA-NIR790) were demonstrated. The use of cyanine dyes for the selective accumulation of cancer cells were used to achieve the characteristics of tumor markers. Therefore, all kinds of organ tumors can be targeted for diagnosis and treatment. The DOTA-NIR790 labeled with lutetium-111 could detect original or metastatic tumors by using SPECT imaging and quantify tumor accumulation. The β-emission of 177 Lu-DOTA-NIR790 can be used for targeted radionuclide therapy of tumors. The DOTA-NIR790 enabled imaging by NIR fluorescence and by nuclear imaging (SPECT) to monitor in real-time the tumor accumulation and the situation of cancer therapy, and to guide the surgery or the photothermal therapy of the tumor. The radionuclide-labeled heptamethine cyanine based probe (DOTA-NIR790) offers multifunctional modalities for imaging and therapies of cancer.

Initiation of T cell receptor (TCR) signaling involves the activation of the tyrosine kinase LCK; however, it is currently unclear how LCK is recruited and activated. Here, we have identified the membrane protein CD146 as an essential member of the TCR network for LCK activation. CD146 deficiency in T cells substantially impaired thymocyte development and peripheral activation, both of which depend on TCR signaling. CD146 was found to directly interact with the SH3 domain of coreceptor-free LCK via its cytoplasmic domain. Interestingly, we found CD146 to be present in both monomeric and dimeric forms in T cells, with the dimerized form increasing after TCR ligation. Increased dimerized CD146 recruited LCK and promoted LCK autophosphorylation. In tumor models, CD146 deficiency dramatically impaired the antitumor response of T cells. Together, our data reveal an LCK activation mechanism for TCR initiation. We also underscore a rational intervention based on CD146 for tumor immunotherapy.

Peptide vaccines exhibit great potential in cancer therapy via eliciting antigen-specific host immune response and long-term immune memory to defend cancer cells. However, the low induced immune response of many developing vaccines implies the imperatives for understanding the favorable structural features of efficient cancer vaccines. Herein, we report on the two groups of self-adjuvanting peptide vaccines with distinct morphology and investigate the relationship between the morphology of peptide vaccines and the induced immune response. Two nanofibril peptide vaccines were created via co-assembly of a pentapeptide with a central 4-aminoproline residue, with its derivative functionalized with antigen epitopes derived from human papillomavirus E7 proteins, whereas utilization of a pentapeptide with a natural proline residue led to the formation of two nanoparticle peptide vaccines. The immunological results of dendritic cell (DCs) maturation and antigen presentation induced by the peptide assemblies implied the self-adjuvanting property of the resulting peptide vaccines. In particular, cellular uptake studies revealed the enhanced internalization and elongated retention of the nanofibril peptide vaccines in DCs, leading to their advanced performance in DC maturation, accumulation at lymph nodes, infiltration of cytotoxic T lymphocytes into tumor tissues, and eventually lysis of in vivo tumor cells, compared to the nanoparticle counterparts. The antitumor immune response caused by the nanofibril peptide vaccines was further augmented when simultaneously administrated with anti-PD-1 checkpoint blockades, suggesting the opportunity of the combinatorial immunotherapy by utilizing the nanofibril peptide vaccines. Our findings strongly demonstrate a robust relationship between the immune response of peptide vaccines and their morphology, thereby elucidating the critical role of morphological control in the design of efficient peptide vaccines and providing the guidance for the design of efficient peptide vaccines in the future.

Neoantigen vaccines are an immunotherapy strategy for treating cancer. The vaccine degrades quickly, so the strategy must include protection and precise targeting for immune cell stimulation. In this study, we engineered attenuated Salmonella typhimurium , which is highly infiltrative to tumors, to act as a carrier for Neoantigen peptide vaccine. Our system used a constitutive promoter vector, so that a single injection of Salmonella expressing Neoantigen could be used without requiring additional induction injections. In vivo experiments on bacteria-treated mice showed that Neoantigen expressed by the engineered carrier infiltrated tumors and resulted in suppressed tumor growth, higher survival rates and longer survival times, a relative increase of CD4 and CD8 T cells, and cytokine release. These results indicate that engineered Salmonella can be used as a carrier for Neoantigen immunotherapy.

Background: Sonodynamic therapy (SDT) strategies exhibit a high tissue penetration depth and can achieve therapeutic efficacy by facilitating the intertumoral release of reactive oxygen species (ROS) with a short lifespan and limited diffusion capabilities. The majority of SDT systems developed to date are of the highly O 2 -dependent type II variety, limiting their therapeutic utility in pancreatic cancer and other hypoxic solid tumor types., Results: Herein, a nucleus-targeted ultra-small Ti-tetrakis(4-carboxyphenyl)porphyrin (TCPP) metal-organic framework (MOF) platform was synthesized and shown to be an effective mediator of SDT. This MOF was capable of generating large quantities of ROS in an oxygen-independent manner in response to low-intensity ultrasound (US) irradiation (0.5 W cm -2 ), thereby facilitating both type I and type II SDT. This approach thus holds great promise for the treatment of highly hypoxic orthotopic pancreatic carcinoma solid tumors. This Ti-TCPP MOF was able to induce in vitro cellular apoptosis by directly destroying DNA and inducing S phase cell cycle arrest following US irradiation. The prolonged circulation, high intratumoral accumulation, and nucleus-targeting attributes of these MOF preparations significantly also served to significantly inhibit orthotopic pancreatic tumor growth and prolong the survival of tumor-bearing mice following Ti-TCPP + US treatment. Moreover, this Ti-TCPP MOF was almost completely cleared from mice within 7 days of treatment, and no apparent treatment-associated toxicity was observed., Conclusion: The nucleus-targeted ultra-small Ti-TCPP MOF developed herein represents an effective approach to the enhanced SDT treatment of tumors in response to low-intensity US irradiation., (© 2021. The Author(s).)

Aims: In hypoxic tumor microenvironments, the strongly reducing redox environment reduces evofosfamide (TH-302) to release a cytotoxic bromo-isophosphoramide (Br-IPM) moiety. This drug therefore preferentially attacks hypoxic regions in tumors where other standard anticancer treatments such as chemotherapy and radiation therapy are often ineffective. Various combination therapies with evofosfamide have been proposed and tested in preclinical and clinical settings. However, the treatment effect of evofosfamide monotherapy on tumor hypoxia has not been fully understood, partly due to the lack of quantitative methods to assess tumor pO 2 in vivo . Here, we use quantitative pO 2 imaging by electron paramagnetic resonance (EPR) to evaluate the change in tumor hypoxia in response to evofosfamide treatment using two pancreatic ductal adenocarcinoma xenograft models: MIA Paca-2 tumors responding to evofosfamide and Su.86.86 tumors that do not respond. Results: EPR imaging showed that oxygenation improved globally after evofosfamide treatment in hypoxic MIA Paca-2 tumors, in agreement with the ex vivo results obtained from hypoxia staining by pimonidazole and in apparent contrast to the decrease in K trans observed in dynamic contrast-enhanced magnetic resonance imaging (DCE MRI). Innovations: The observation that evofosfamide not only kills the hypoxic region of the tumor but also improves oxygenation in the residual tumor regions provides a rationale for combination therapies using radiation and antiproliferatives post evofosfamide for improved outcomes. Conclusion: This study suggests that reoxygenation after evofosfamide treatment is due to decreased oxygen demand rather than improved perfusion. Following the change in pO 2 after treatment may therefore yield a way of monitoring treatment response. Antioxid. Redox Signal . 35, 904-915.

The adoptive transfer of antigen-specific T cells has been successfully applied in the treatment of hematological malignancies. However, its application in the treatment of solid tumors has been overshadowed by the immunosuppressive tumor microenvironment. In this context, a preprocessing strategy is developed to reprogram the immunosuppressive tumor microenvironment using a thermoresponsive hydrogel loaded with doxorubicin (DOX@Gel). Compared with hydrogel-based chemotherapy alone or adoptive T cell therapy alone, this combination exhibits enhanced anti-tumor efficacy. In addition to the direct killing of tumor cells, the local chemotherapy releases tumor-associated antigens which enhance the proliferation and effector function of endogenous and adoptively transferred T cells. Moreover, DOX@Gel significantly reduces the numbers of both myeloid derived suppressor cells and Tregs in tumor microenvironment. It is suggested that DOX@Gel promotes the efficacy of adoptively transferred T cells against solid tumors, overcoming the key limitations of adoptive T cell therapy., (© 2021 Wiley-VCH GmbH.)

The availability of L-arginine in tumours is a key determinant of an efficient anti-tumour T cell response 1-4 . Consequently, increases of typically low L-arginine concentrations within the tumour may greatly potentiate the anti-tumour responses of immune checkpoint inhibitors, such as programmed death-ligand 1 (PD-L1)-blocking antibodies 5 . However, currently no means are available to locally increase intratumoural L-arginine levels. Here we used a synthetic biology approach to develop an engineered probiotic Escherichia coli Nissle 1917 strain that colonizes tumours and continuously converts ammonia, a metabolic waste product that accumulates in tumours 6 , to L-arginine. Colonization of tumours with these bacteria increased intratumoural L-arginine concentrations, increased the number of tumour-infiltrating T cells and had marked synergistic effects with PD-L1 blocking antibodies in the clearance of tumours. The anti-tumour effect of these bacteria was mediated by L-arginine and was dependent on T cells. These results show that engineered microbial therapies enable metabolic modulation of the tumour microenvironment leading to enhanced efficacy of immunotherapies., (© 2021. The Author(s), under exclusive licence to Springer Nature Limited.)

Targeted immunotherapies have greatly changed treatment of patients with B cell malignancies. To further enhance immunotherapies, research increasingly focuses on the tumor microenvironment (TME), which differs considerably by organ site. However, immunocompetent mouse models of disease to study immunotherapies targeting human molecules within organ-specific TME are surprisingly rare. We developed a myc -driven, primary murine lymphoma model expressing a human-mouse chimeric CD22 (h/mCD22). Stable engraftment of three distinct h/mCD22 + lymphoma was established after subcutaneous and systemic injection. However, only systemic lymphoma showed immune infiltration that reflected human disease. In this model, myeloid cells supported lymphoma growth and showed a phenotype of myeloid-derived suppressor cells. The human CD22-targeted immunotoxin Moxetumomab was highly active against h/mCD22 + lymphoma and similarly reduced infiltration of bone marrow and spleen of all three models up to 90-fold while efficacy against lymphoma in lymph nodes varied substantially, highlighting relevance of organ-specific TME. As in human aggressive lymphoma, anti-PD-L1 as monotherapy was not efficient. However, anti-PD-L1 enhanced efficacy of Moxetumomab suggesting potential for future clinical application. The novel model system of h/mCD22 + lymphoma provides a unique platform to test targeted immunotherapies and may be amenable for other human B cell targets such as CD19 and CD20.

Invariant natural killer T (iNKT) cells are a T-cell subset with potent immunomodulatory properties. Experimental evidence in mice and observational studies in humans indicate that iNKT cells have antitumor potential as well as the ability to suppress acute and chronic graft-versus-host-disease (GVHD). Murine iNKT cells differentiate during thymic development into iNKT1, iNKT2, and iNKT17 sublineages, which differ transcriptomically and epigenomically and have subset-specific developmental requirements. Whether distinct iNKT sublineages also differ in their antitumor effect and their ability to suppress GVHD is currently unknown. In this work, we generated highly purified murine iNKT sublineages, characterized their transcriptomic and epigenomic landscape, and assessed specific functions. We show that iNKT2 and iNKT17, but not iNKT1, cells efficiently suppress T-cell activation in vitro and mitigate murine acute GVHD in vivo. Conversely, we show that iNKT1 cells display the highest antitumor activity against murine B-cell lymphoma cells both in vitro and in vivo. Thus, we report for the first time that iNKT sublineages have distinct and different functions, with iNKT1 cells having the highest antitumor activity and iNKT2 and iNKT17 cells having immune-regulatory properties. These results have important implications for the translation of iNKT cell therapies to the clinic for cancer immunotherapy as well as for the prevention and treatment of GVHD., (© 2021 by The American Society of Hematology.)

"Bug as drug" is a concept recognized over a century ago and has gained significant research attention recently for fighting diseases such as immune disorders and others. Bacteria and viruses are constantly studied for this purpose, but the use of parasitic organisms is still rare. Recently, we found that Toxoplasma gondii mutants lacking two lactate dehydrogenases (ME49 Δldh1-Δldh2) were avirulent in mice but able to stimulate high levels of Th1 immunity. This outcome prompted us to determine whether Δldh mutants also displayed antitumor activities. Using a mouse melanoma model, we showed that intratumoral administration of Δldh1-Δldh2 repressed the growth of established tumors and helped to inhibit lethal tumor development in the mice. The sera of parasite-treated mice had high levels of TNF-α and INF-γ, which likely contributed to the tumor-repressing activity. We also found that chronic Toxoplasma infection, which is common in animals and humans, also led to antitumor activity. In addition, pre-existing chronic infections did not affect the antitumor efficiency of the Δldh1-Δldh2 mutant. Together, these results suggest that the attenuated T. gondii mutant Δldh1-Δldh2 has the potential to be a good antitumor therapy and provide new insights into the development of novel tumor therapeutics., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: One of the major factors restricting in vivo efficacy of dendritic cells (DCs) based immunotherapy is the inefficient migration of these cells to the lymphoid tissue, wherein DCs activate antigen-specific T cells. A fundamentally new approach for the possibility of enhancing the antitumor effects of DC-based immunotherapy may be the use of magnetically sensitive nanocomplexes to increase the target delivery of DCs to the lymph nodes of the recipient., Aim: To study the antitumor and immunomodulatory effects of the DC-nanovaccine with magnetosensitive properties and its influence on the immunosuppressive tumor microenvironment in mice with sarcoma 37., Materials and Methods: The antitumor, antimetastatic and immunomodulatory effects of DCs loaded with magnetic nanocomplex under magnetic field (MF) control in mice with sarcoma 37 have been investigated., Results: Combined therapy contributed to a significant reduction in tumor volume and weight compared to the control group of mice and mice that received the DC vaccine without MF. Therapy with magnetically sensitive DC nanovaccine with and without the addition of the MF was accompanied by a significant down-regulation of the level of FoxP3, transforming growth factor β, interleukin (IL)-10 and vascular endothelial growth factors, mRNA expression in tumor tissues. A significant increase in interferon-γ and IL-4 mRNA expression was found in mice treated with the magnetically sensitive DC nanovaccine under MF control., Conclusion: A significant increase in the antitumor efficacy of the DC vaccine can be achieved using magnetosensitive nanocarriers of tumor antigens under MF control.

Nanomedicine can regulate the balance between cytotoxic T lymphocytes (CTLs) and suppressive regulatory T lymphocytes (Tregs), which however has been rarely exploited for cancer immunotherapy. We report a charge-reversal polymer nano-modulator (SP DMC N) activated by tumor microenvironment (TME) for photodynamic immunotherapy of cancer. SP DMC N is constructed by conjugating an immunomodulator (demethylcantharidin, DMC) to the side chains of a photodynamic polymer via an acid-liable linker. The negative charge of SP DMC N ensures its high stability in blood circulation and ideal tumor accumulation; exposure to acidic TME reverses its surface charge to positive, enhancing tumor penetration and locally releasing DMC. Upon near-infrared photoirradiation, SP DMC N generates singlet oxygen to ablate tumors and promote maturation of dendritic cells. Released DMC inhibits protein phosphatase 2 (PP2A) activity and decreases Tregs differentiation. Such combinational action induces a sharp increase in CTL/Treg ratio in TME and effectively inhibits both primary and distant tumors in living mice., (© 2021 Wiley-VCH GmbH.)

Due to its highly immunogenic nature and the great engineerability, filamentous phage has shown promising antitumor activities in preclinical studies. Previous designs of antitumor phage mainly focused on tumor targeting using a cancer-specific moiety displayed on the minor capsid protein, pIII. In this work, we developed a new therapeutic platform of filamentous phage, in which the major capsid protein pVIII was utilized for displaying an antitumor cytokine. We showcased that a 16.1-kD cytokine GM-CSF could be efficiently presented on the M13 phage particle using the 8 + 8 type display system through a highly tolerable pVIII variant P8(1a). We verified that the GM-CSF phage was a potent activator for STAT5 signaling in murine macrophage. The GM-CSF phage significantly reduced the tumor size by more than 50% as compared to the unmodified phage in a murine colorectal cancer model. Immunological profiling of the tumor-infiltrating leukocytes revealed that an increase of CD4+ lymphocytes in the GM-CSF phage treatment group. Furthermore, the combined therapy of the GM-CSF phage and radiation greatly improved the therapeutic potency with a 100% survival rate and a 25% complete remission rate. We observed that the IFN-γ expression was dramatically up-regulated by the combined therapy in multiple types of tumor-infiltrating immune cells. Overall, we created a novel vehicle for cytokine therapy using the pVIII filamentous phage display. This new platform can be multiplexed with other phage engineering approaches, such as displaying targeting ligands on pIII or encapsulating therapeutic genes inside phage capsids, to create multifunctional nanoparticles for cancer therapy.

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive malignancy that is characterized by early metastasis, low resectability, high recurrence, and therapy resistance. The experimental mouse models have played a central role in understanding the pathobiology of PDAC and in the preclinical evaluation of various therapeutic modalities. Different mouse models with targetable pathological hallmarks have been developed and employed to address the unique challenges associated with PDAC progression, metastasis, and stromal heterogeneity. Over the years, mouse models have evolved from simple cell line-based heterotopic and orthotopic xenografts in immunocompromised mice to more complex and realistic genetically engineered mouse models (GEMMs) involving multi-gene manipulations. The GEMMs, mostly driven by KRAS mutation(s), have been widely accepted for therapeutic optimization due to their high penetrance and ability to recapitulate the histological, molecular, and pathological hallmarks of human PDAC, including comparable precursor lesions, extensive metastasis, desmoplasia, perineural invasion, and immunosuppressive tumor microenvironment. Advanced GEMMs modified to express fluorescent proteins have allowed cell lineage tracing to provide novel insights and a new understanding about the origin and contribution of various cell types in PDAC pathobiology. The syngeneic mouse models, GEMMs, and target-specific transgenic mice have been extensively used to evaluate immunotherapies and study therapy-induced immune modulation in PDAC yielding meaningful results to guide various clinical trials. The emerging mouse models for parabiosis, hepatic metastasis, cachexia, and image-guided implantation, are increasingly appreciated for their high translational significance. In this article, we describe the contribution of various experimental mouse models to the current understanding of PDAC pathobiology and their utility in evaluating and optimizing therapeutic modalities for this lethal malignancy., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Therapeutic gene silencing by RNA interference relies on the safe and efficient in vivo delivery of small interfering RNAs (siRNAs). Polyethylenimines are among the most studied cationic polymers for gene delivery. For several reasons including superior tolerability, small linear PEIs would be preferable over branched PEIs, but they show poor siRNA complexation. Their chemical modification for siRNA formulation has not been extensively explored so far. We generated a set of small linear PEIs bearing tyrosine modifications (LPxY), leading to substantially enhanced siRNA delivery and knockdown efficacy in vitro in various cell lines, including hard-to-transfect cells. The tyrosine-modified linear 10 kDa PEI (LP10Y) is particularly powerful, associated with favorable physicochemical properties and very high biocompatibility. Systemically administered LP10Y/siRNA complexes reveal antitumor effects in mouse xenograft and patient-derived xenograft (PDX) models, and their direct application into the brain achieves therapeutic inhibition of orthotopic glioma xenografts. LP10Y is particularly interesting for therapeutic siRNA delivery., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Oncolytic viruses (OVs) are promising alternative biological agents for treating cancer. However, triggered immune responses against viruses and their delivery to tumor sites are their primary limitations in cancer therapy. To address these challenges, mesenchymal stem cells (MSCs) can serve as permissive tools for OVs loading and delivery to tumor sites. Here, we evaluated the in vitro and in vivo antitumor capability of adipose-derived mesenchymal stem cells (AD-MSCs) as a new vehicle for Dearing strain of reovirus (ReoT3D) loading. We first isolated and confirmed the purity of MSCs, and the optimized dose of ReoT3D for MSCs loading was computed by a standard assay. Next, we used murine CT26 cell line to establish the colorectal cancer model in BALB/c mice and demonstrated the antitumor effects of MSCs loaded with reovirus. Our results demonstrated that multiplicity of infection (MOI) 1 pfu/cells of reovirus was the safe dose for loading into purified MSCs. Moreover, our anticancer experiments exhibited that treatment with MSCs loaded with ReoT3D was more effective than ReoT3D and MSCs alone. Higher anticancer impact of MSCs loaded with OV was associated with induction of apoptosis, cell cycle arrests, P53 expression in tumor sections, and reduced tumor growth and size. The present results suggest that MSCs as a permissive shuttle for oncolytic virus (OV) delivery increased the anticancer activity of ReoT3D in mice models of colorectal cancer and these findings should be supported by more preclinical and clinical studies., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Nonresponse, or acquired resistance to immune checkpoint inhibitors in colorectal cancer (CRC) highlight the importance of finding potential tolerance mechanisms. Low expression of major histocompatibility complex, class I (MHC-I) on the cell surface of the tumor is one of the main mechanisms of tumor escape from T-cell recognition and destruction. In this study, we demonstrated that a high level of calnexin (CANX) in the tumors is positively correlated with the overall survival in colorectal cancer patients. CANX is a chaperone protein involved in the folding and assembly of MHC-I molecules. Using miRNA target prediction databases and luciferase assays, we identified miR-148a-3p as a potential regulator of CANX. Inhibition of miR-148a-3p restores surface levels of MHC-I and significantly enhanced the effects of CD8 + T-cell-mediated immune attack in vitro and in vivo by promoting CANX expression. These results reveal that miR-148a-3p can function as a tumor promotor in CRC by targeting the CANX/MHC-I axis, which provides a rationale for immunotherapy through targeting the miR-148a-3p/CANX/MHC-I pathway in patients with CRC., (© 2021 Federation of American Societies for Experimental Biology.)

A coated microneedle patch is a reliable way to load gene on a surface as a transdermal gene delivery platform. But there are many limitations to the traditional methods to fabricate a coated microneedle patch, such as the fact that they are time consuming or the difficulty in controlling the loading content. In this research, ultrasonic spraying technology, as an industrialized production method, was first used to fabricate a gene-coated microneedle patch. First, the p53 expression plasmid (p53 DNA) was ultrasonically sprayed on a polycaprolactone (PCL) microneedle patch (D@MNP). To promote the transfection efficiency, polycation polyethylenimine (PEI), as a vector, was then ultrasonically sprayed on D@MNP (P@D@MNP). From the experimental results, although two layers were sprayed step by step, no obvious stratification could be observed. The vector PEI interweaved with genes and inhibited the gene release profile, but it changed the released naked genes to positively charged complexes, which would promote gene transfection efficiency. In subsequent in vivo experiments, the anti-tumor efficacy of the "P@D@MNP treated group" could reach 84.7%, although it had the lowest gene release profile. In contrast, the anti-tumor efficacy of the "intravenous injection group" and "D@MNP treated group" was only 24.3% and 59.3%, respectively. Overall, P@D@MNP was a safe and efficient device to treat the subdermal tumor. Ultrasonic spraying technology provided an industrialized method to fabricate the coated microneedle patch as a transdermal gene/drug delivery platform.