Mouse Tumor Models Research Articles

Surface ligand-regulated renal clearance of MRI/SPECT dual-modality nanoprobes for tumor imaging

BackgroundThe general sluggish clearance kinetics of functional inorganic nanoparticles tend to raise potential biosafety concerns for in vivo applications. Renal clearance is a possible elimination pathway for functional inorganic nanoparticles delivered through intravenous injection, but largely depending on the surface physical chemical properties of a given particle apart from its size and shape.ResultsIn this study, three small-molecule ligands that bear a diphosphonate (DP) group, but different terminal groups on the other side, i.e., anionic, cationic, and zwitterionic groups, were synthesized and used to modify ultrasmall Fe3O4 nanoparticles for evaluating the surface structure-dependent renal clearance behaviors. Systematic studies suggested that the variation of the surface ligands did not significantly increase the hydrodynamic diameter of ultrasmall Fe3O4 nanoparticles, nor influence their magnetic resonance imaging (MRI) contrast enhancement effects. Among the three particle samples, Fe3O4 nanoparticle coated with zwitterionic ligands, i.e., Fe3O4@DMSA, exhibited optimal renal clearance efficiency and reduced reticuloendothelial uptake. Therefore, this sample was further labeled with 99mTc through the DP moieties to achieve a renal-clearable MRI/single-photon emission computed tomography (SPECT) dual-modality imaging nanoprobe. The resulting nanoprobe showed satisfactory imaging capacities in a 4T1 xenograft tumor mouse model. Furthermore, the biocompatibility of Fe3O4@DMSA was evaluated both in vitro and in vivo through safety assessment experiments.ConclusionsWe believe that the current investigations offer a simple and effective strategy for constructing renal-clearable nanoparticles for precise disease diagnosis.Graphical

Irradiated microparticles suppress prostate cancer by tumor microenvironment reprogramming and ferroptosis

Immunogenic cell death (ICD) plays a crucial role in triggering the antitumor immune response in the tumor microenvironment (TME). Recently, considerable attention has been dedicated to ferroptosis, a type of ICD that is induced by intracellular iron and has been demonstrated to change the immune desert status of the TME. However, among cancers that are characterized by an immune desert, such as prostate cancer, strategies for inducing high levels of ferroptosis remain limited. Radiated tumor cell-derived microparticles (RMPs) are radiotherapy mimetics that have been shown to activate the cGAS-STING pathway, induce tumor cell ferroptosis, and inhibit M2 macrophage polarization. RMPs can also act as carriers of agents with biocompatibility. In the present study, we designed a therapeutic system wherein the ferroptosis inducer RSL-3 was loaded into RMPs, which were tested in in vitro and in vivo prostate carcinoma models established using RM-1 cells. The apoptosis inducer CT20 peptide (CT20p) was also added to the RMPs to aggravate ferroptosis. Our results showed that RSL-3- and CT20p-loaded RMPs (RC@RMPs) led to ferroptosis and apoptosis of RM-1 cells. Moreover, CT20p had a synergistic effect on ferroptosis by promoting reactive oxygen species (ROS) production, lipid hydroperoxide production, and mitochondrial instability. RC@RMPs elevated dendritic cell (DC) expression of MHCII, CD80, and CD86 and facilitated M1 macrophage polarization. In a subcutaneously transplanted RM-1 tumor model in mice, RC@RMPs inhibited tumor growth and prolonged survival time via DC activation, macrophage reprogramming, enhancement of CD8+ T cell infiltration, and proinflammatory cytokine production in the tumor. Moreover, combination treatment with anti-PD-1 improved RM-1 tumor inhibition. This study provides a strategy for the synergistic enhancement of ferroptosis for prostate cancer immunotherapies.Graphical

Exploring the anticancer potential of double-active pharmaceutical ingredient, metforminium ibuprofenate: Integrating in vivo and in silico investigations

Rationale: A novel double active pharmaceutical ingredient (d-API), metforminium ibuprofenate (MtHIb) was synthesised by combining metformin hydrochloride (MtHCl) and sodium ibuprofen (NaIb). This formulation exhibits anti-diabetic and anti-inflammatory properties similar to its parent compounds, along with a remarkable antiproliferative effect on diverse cancer cells. AimThe present study is aimed to analyse the anticancer potential of MtHIb by mouse tumour model and molecular docking. MethodsSolid tumour was induced by Dalton's Lymphoma Ascites (DLA) cells in Swiss albino mice, and d-API was administered orally. The tumour volume was measured using Vernier calliper and the activity of γ-glutamyl transferase (GGT) was assessed. The potential interactions of MtHIb with target proteins mTOR, HER2, EGFR, CDK4, CDK6, ERα/β, progesterone, COX2, BUB1, and KEAP2 were analyzed in silico. ResultsA significant reduction in tumour size was observed in mice treated with MtHIb. On the 30th day, the tumour volume, which was 8.12 cm3 in untreated animals, decreased to 1.311 cm3 with the treatment of 5 mg/kg b.wt of MtHIb, representing an 83.8 % reduction. The activity of GGT, a marker enzyme of proliferative activity, was considerably reduced from 394.87 to 51.26 U/mg protein/L. Molecular docking studies indicated that MtHIb exhibited strong binding affinity towards all the screened target proteins, specifically HER2, EGFR, CDK4, and BUB1. DiscussionThe findings suggest that MtHIb has promising anti-tumour effect, as evidenced by its significant reduction in tumour size and GGT activity in mice. The strong binding affinity of MtHIb towards the key cancer related proteins further supports its potential as a therapeutic agent against cancer, particularly in targeting pathways involved in cell proliferation and survival. Further preclinical and clinical studies are required to validate these findings and to explore the full therapeutic potential of MtHIb in cancer treatment.

Structural engineering of magnetite nanozymes for enhanced chemodynamic cancer therapy

Magnetite nanoparticles have demonstrated great potential as nanozymes in chemodynamic therapy (CDT) for cancer. However, their in vivo efficiency remains limited. Here we developed magnetite nanozymes (MNZs) with dual enzyme activities and demonstrated their shape-dependent behavior in eradicating tumors. Three versions of MNZs were constructed of the same materials but largely different geometric forms: spherical (SMNZ), elliptic (EMNZ) and flaky (FMNZ); they were evaluated against each other in treating an aggressive mouse tumor model of triple-negative breast cancer. We showed that the shape influence is substantial, and with the optimal geometric form, FMNZ dramatically outperform its two counterparts and demonstrates phenomenal ability to shrink tumors via systemic injection. We further illustrated that the vastly increased treatment efficiency can be attributed to the large surface area of FMNZ that resulted in increased cellular uptake, greater iron ions release and increased production of highly toxic hydroxyl radicals (•OH), which leads to enhanced self-cascade CDT.

Discovery and pharmacological characterization of 1,2,3,4-tetrahydroquinoline derivatives as RORγ inverse agonists against prostate cancer.

The retinoic acid receptor-related orphan receptor γ (RORγ) is regarded as an attractive therapeutic target for the treatment of prostate cancer. Herein, we report the identification, optimization, and evaluation of 1,2,3,4-tetrahydroquinoline derivatives as novel RORγ inverse agonists, starting from high throughput screening using a thermal stability shift assay (TSA). The representative compounds 13e (designated as XY039) and 14a (designated as XY077) effectively inhibited the RORγ transcriptional activity and exhibited excellent selectivity against other nuclear receptor subtypes. The structural basis for their inhibitory potency was elucidated through the crystallographic study of RORγ LBD complex with 13e. Both 13e and 14a demonstrated reasonable antiproliferative activity, potently inhibited colony formation and the expression of AR, AR regulated genes, and other oncogene in AR positive prostate cancer cell lines. Moreover, 13e and 14a effectively suppressed tumor growth in a 22Rv1 xenograft tumor model in mice. This work provides new and valuable lead compounds for further development of drugs against prostate cancer.

Abstract PO3-24-02: Molecular characterization and therapeutic approach for VISTA+ triple-negative breast cancers

Abstract Introduction: Current FDA-approved immunotherapeutics for triple-negative breast cancer are only available for a subset of patients, highlighting the need to develop improved immune-targeting strategies. VISTA (V-domain Ig suppressor of T cell activation) is a single-pass transmembrane immune checkpoint receptor that is an emerging clinical target for cancer immunotherapy. It is expressed widely on lymphoid and myeloid cells in healthy individuals, is commonly expressed on cells of the tumor microenvironment and can be abnormally upregulated on tumor cells in a wide variety of tumors. Although VISTA confers quiescence to naïve T cells, molecular mechanisms responsible for this effect remain unclear. Also, the effects of VISTA expression on tumor cells remains poorly defined. Methods: Multi-omic profiling was performed in human breast cancer cells lines to determine immune regulatory genes controlled by growth factor stimulation. Human triple-negative breast cancer tumor specimens (N=248) were examined by immunohistochemistry for expression of VISTA, PDL1, PD1 and FoxP3. VISTA expression was engineered into human and mouse triple-negative breast cancer cell lines and growth metrics were characterized in vitro and in immunocompetent (syngeneic) and immunodeficient (xenograft) mouse tumor models. Membrane receptor trafficking and localization of EGFR was performed in human TNBC cells lines expressing VISTA and VISTA mutants. Proximity biotinylation identified protein partners that interacted with VISTA’s intracellular domain. Deletion mutagenesis was performed to identify motifs required for biochemical interactions between VISTA and clathrin adaptor proteins. Clathrin adapter localization was examined in WT and VISTA knock-out cell lines. Cytokine response, clathrin adaptor localization and tumor growth kinetics were measured in TNBC cell lines expressing VISTA or VISTA mutants. Results: A class of human triple-negative breast cancers were identified with high VISTA expression, low tumor infiltrating lymphocytes and low proliferative index (8-20% of all TNBCs). Tumor models demonstrated that enforced expression of VISTA in tumor cells caused growth suppression, even in the absence of an immune system. This effect was mapped to the cytoplasmic domain of VISTA, which lacks defined signaling domains. Through biochemical approaches, the clathrin-adaptor molecules NUMB and GULP1 were found in complex with a VISTA intracellular NPGF motif. This motif sequestered NUMB at early endosomes, resulting in diminished NUMB recycling for EGFR endocytosis, thereby causing growth suppression. VISTA impaired NUMB recycling by blocking Rab11 effector complex formation. VISTA NPGF mutations did not disrupt cytokine secretion in mixed lymphocyte assays. VISTA-targeted antibodies did not disrupt NUMB sequestration. VISTA+ tumors were selectively sensitive to VISTA-blocking antibodies. Conclusions: VISTA+ TNBC have distinct features including slower proliferative index and increased sensitivity to VISTA-blocking antibodies. This work identifies mechanisms by which VISTA enforces a quiescent cellular state by sequestering clathrin adapter proteins away from sites of endocytosis in cancer cells. This is the first description of intracellular molecular mechanisms controlled by VISTA’s intracellular tail. It may inform features of the VISTA-dependent immune checkpoint that could be exploited to improve anti-tumor immunity. Citation Format: Yan Zhao, Fatima Charles, Andrew Lipchik, Yan Peng, James Ford, Melinda Telli, Song Zhang, Allison Kurian, Michael Snyder, Joshua Gruber. Molecular characterization and therapeutic approach for VISTA+ triple-negative breast cancers [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO3-24-02.

Abstract PO3-25-02: Circadian Rhythm Disruption Accelerates Aggressive Mammary Tumorigenesis by Altering Tumor Microenvironment

Abstract \Breast cancer is the most common cancer in women worldwide, leading to over 650,000 deaths worldwide. The circadian rhythm is a 24-hour biological rhythm that controls most cellular, hormonal, and behavioral processes in living organisms, which is why perturbation of these rhythms is linked to several devastating diseases such as cardiovascular diseases, diabetes, and cancer. In the mammary gland, circadian clocks regulate the rhythmic expression of numerous genes. Circadian rhythm disruption (CRD), which has been termed a "carcinogen" by the International Agency for Research in Cancer, is caused by different factors, one of them being shift work. Several epidemiological studies have revealed that women who work night shifts are predisposed to breast cancer. The aim of this study is to investigate the effect of circadian rhythm disruption on aggressive mammary tumorigenesis. To do this, we used genetically engineered mouse models of mammary tumors (HER2-tumor and triple-negative breast tumor, or TNBC). Chronic jetlag, which mimics shift work in mice and is known to cause CRD, was introduced in one group of mice by perturbing the normal light and dark cycles with an 8-hour advance every three days. Wheel-running, which is represented by an actogram, was used to confirm the circadian disruption in the CRD mice. CRD was found to accelerate tumor initiation with a significant increase in weight in the CRD group of mice. CRD enhanced tumor burden significantly compared to LD mice. Our results also showed high metastatic foci in the lungs of CRD mice compared to LD mice. A flow cytometry study showed a higher cancer stem cell population in CRD tumors. Mammosphere assays with tumor-derived cells showed that CRD increased the number and size of the mammospheres compared to the control tumors. The tumor cells were analyzed using single-cell RNA sequencing, which showed that CRD alters the tumor microenvironment by developing more immunosuppressive and "cold" tumors. The tumor-derived organoids (tumoroid) showed resistance to chemotherapeutics. Finally, bioinformatics analysis using single-cell RNA seq data from human breast tumors (TNBC, ER/PR, and HER2) showed that the malignant cells in TNBC tumors had a significantly higher circadian rhythm disrupted score (CRD score) compared to ER/PR tumors. Taken together, our data showed how circadian rhythm disruption affects TNBC tumorigenesis and drug response by altering the tumor microenvironment. Citation Format: Olajumoke Ogunlusi, Mrinmoy Sarkar, Tristan Nguyen, Devon Boland, James Cai, Arhit Chakrabarti, Bani Mallick, Alex Keene, Tapasree Roy Sarkar. Circadian Rhythm Disruption Accelerates Aggressive Mammary Tumorigenesis by Altering Tumor Microenvironment [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO3-25-02.

Abstract PO1-14-06: Integrated analysis reveals the impact of obesity on triple-negative breast cancer

Abstract Background: Obesity and overweight status, which has been growing rapidly over the past few decades, is considered as a risk factor for many types of cancers including breast cancer. Despite the multi-omics profile of triple-negative breast cancer (TNBC) has been comprehensively characterized, the impact of obesity on molecular features of TNBC is not fully appreciated. Methods: We applied an integrative analysis on clinicopathological data and molecular data (including genomic, transcriptomic, proteomic and metabolomic profiling) using the multi-omics database of TNBC (N = 465) from Fudan University Shanghai Cancer Center (FUSCC) for associations with patient body mass index (BMI). Patients were categorized into overweight/obese (OW/OB, BMI ≥ 24 kg/m2) and normal (NL, BMI < 24 kg/m2) group according to the Chinese criteria of BMI. The clinical and molecular differences between OW/OB and NL patients were systematically explored. We also constructed high-fat diet (HFD)-induced obese mouse tumor models and used single-cell RNA sequencing to investigate the impact of obesity on the tumor microenvironment. Furthermore, we analyzed the efficacy of anti-PD-1 immunotherapy on TNBC tumors in both obese and normal mice. Results: OW/OB patients exhibited higher proportion of metabolic syndrome, more adipose tissue in the breast and worse survival than NL patients. Among most frequently mutated genes, OBSCN showed statistically significantly less mutated in the OW/OB group (3.2% vs 9.6%), while TP53 (68.3% vs 76.9%) and PIK3CA (21.4% vs 14.1%) had tendency to be different. In terms of copy number alterations, we found OW/OB patients had a higher amplified or gained frequency of 13q14.11 (FOXO1) and a lower frequency of deletion or loss of chromosomal region 7p22.1 (FOXK1). We further dissect the expression profile of TNBC. Differentially expressed gene analysis and pathway enrichment analysis demonstrated that immune and metabolic pathways were the major distinction between OW/OB and NL tumors. OW/OB tumors were characterized with elevated inflammation of tumor microenvironment, as well as higher expression of immune checkpoints. Moreover, analyses focusing on metabolic heterogeneity using transcriptomic, proteomic and metabolomic data revealed upregulation of lipid metabolism and reactive oxygen species pathway in OW/OB group. In addition, our in vivo experiments demonstrated that TNBC in the obese mice displayed faster growth rates. Flow cytometry analysis and single-cell RNA sequencing showed that higher proportion of immunosuppressive myeloid cells and exhausted CD8+ T cells and upregulation of lipid metabolism in HFD group. Applying anti-PD-1 immunotherapy in both obese and normal mice displayed that tumors in the obese mice showed more sensitive to anti-PD-1 immunotherapy. Conclusion: Our study systematically revealed that obesity might play a significant role in the molecular heterogeneity of TNBC and showed distinct sensitivities to immunotherapy, which should be taken in account in the field of precision medicine. Keywords: triple-negative breast cancer, obesity, immune, tumor microenvironment, metabolism Citation Format: Yue Gong, Peng Ji, Huai-liang Wu, Li-Hua He, Ming-Liang Jin, Xin Hu, Yi-Zhou Jiang, Zhiming Shao. Integrated analysis reveals the impact of obesity on triple-negative breast cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-14-06.

A new MVA ancestor-derived oncolytic vaccinia virus induces immunogenic tumor cell death and robust antitumor immune responses

Vaccinia viruses (VACV) are versatile therapeutic agents and different features of various VACV strains allow for a broad range of therapeutic applications. Modified Vaccinia virus Ankara (MVA) is a particularly altered VACV strain that is highly immunogenic, incapable of replicating in mammalian hosts, and broadly used as a safe vector for vaccination. Alternatively, Western Reserve (WR) or Copenhagen (Cop) are VACV strains that efficiently replicate in cancer cells and therefore are used to develop oncolytic viruses. However, the immune evasion capacity of WR or Cop hinders their ability to elicit antitumor immune responses, which is crucial for efficacy in the clinic. Here, we describe a new VACV strain named Immune-Oncolytic Vaccinia virus Ankara (IOVA), which combines efficient replication in cancer cells with induction of immunogenic tumor cell death (ICD). IOVA was engineered from an MVA ancestor and shows superior cytotoxicity in tumor cells. In addition, the IOVA genome incorporates mutations that lead to massive fusogenesis of tumor cells, which contributes to improved antitumor effects. In syngeneic mouse tumor models, induction of ICD results in robust antitumor immunity directed against tumor neo-epitopes and eradication of large established tumors. These data present IOVA as an improved immunotherapeutic oncolytic vector.

Catalytic NIR chemiluminescence sensor with enhanced persistence and intensity for in vivo imaging

Chemiluminescence (CL) is a self-illumination phenomenon that involves the emission of light from chemical reactions, and it provides favorable spatial and temporal information on biological processes. However, it is still a great challenge to construct effective CL sensors that equip strong CL intensity, long emission wavelength, and persistent luminescence for deep tissue imaging. Here, we report a liposome encapsulated polymer dots (Pdots)-based system using catalytic CL substrates (L-012) as energy donor and fluorescent polymers and dyes (NIR 695) as energy acceptors for efficient Near-infrared (NIR) CL in vivo imaging. Thanks to the modulation of paired donor and acceptor distance and the slow diffusion of biomarker by liposome, the Pdots show a NIR emission wavelength (λ em, max = 720 nm), long CL duration (> 24 h), and a high chemiluminescence resonance energy transfer efficiency (46.5%). Furthermore, the liposome encapsulated Pdots possess excellent biocompatibility, sensitive response to H2O2, and persistent whole-body NIR CL imaging in the drug-induced inflammation and the peritoneal metastatic tumor mouse model. In a word, this NIR-II CL nanoplatform with long-lasting emission and high spatial-temporal resolution will be a concise strategy in deep tissue imaging and clinical diagnostics.

YBX1, Targeted By Microrna-382-5p, Promotes Laryngeal Squamous Cell Carcinoma Progression via Modulating RAS/MAPK Signaling.

Laryngeal squamous cell carcinoma (LSCC) is the most common cancer of head and neck cancer. Y-box binding protein-1 (YBX1) has tumor-promoting effects in some types of cancers. However, its role in LSCC remains unknown. This study set out to identify the role of YBX1 in LSCC. Bioinformatics analysis of the Gene Expression Omnibus (GEO) database and our cohort data were used to explore the association of YBX1 expression with clinicopathological factors in LSCC. Then, cells with stably or transiently transfected with plasmid or siRNA were constructed to assess the effect of loss and gain of YBX1 on the biological phenotypes of LSCC cells in vitro. In addition, subcutaneous xenograft and orthotopic liver tumor mouse models were constructed for validation. The interrogated miRNA databases and subsequent luciferase reporter assays were used to confirm the miR-382-5p target of YBX1. At last, KEGG enrichment annotation from TGCA data was used for downstream analyses of miR-382-5p/YBX1 and verified by PCR and Western immunoblotting. The results showed that significant upregulation of YBX1 in LSCC tumors was correlated with advanced TNM stage and poor prognosis. Knockdown of YBX1 markedly impaired the proliferative, invasive, and migratory activity of Tu212 cells. We confirmed that miR-382-5p targets YBX1 to mediate LSCC progression both in vitro and in vivo. We further confirmed that miR-382-5p/YBX1 modulated the Ras/MAPK signaling axis to regulate the progression of LSCC. Together, our results indicated that YBX1 is an important promoter of LSCC progression. And miR-382-5p/YBX1/RAS/MAPK signaling pathway can be perceived as a promising target in the treatment of LSCC.

PD-L1 targeted peptide demonstrates potent antitumor and immunomodulatory activity in cancer immunotherapy

BackgroundIn recent years, immunotherapy has been emerging as a promising alternative therapeutic method for cancer patients, offering potential benefits. The expression of PD-L1 by tumors can inhibit the T-cell response to the tumor and allow the tumor to evade immune surveillance. To address this issue, cancer immunotherapy has shown promise in disrupting the interaction between PD-L1 and its ligand PD-1.MethodsWe used mirror-image phage display technology in our experiment to screen and determine PD-L1 specific affinity peptides (PPL-C). Using CT26 cells, we established a transplanted mouse tumor model to evaluate the inhibitory effects of PPL-C on tumor growth in vivo. We also demonstrated that PPL-C inhibited the differentiation of T regulatory cells (Tregs) and regulated the production of cytokines.ResultsIn vitro, PPL-C has a strong affinity for PD-L1, with a binding rate of 0.75 μM. An activation assay using T cells and mixed lymphocytes demonstrated that PPL-C inhibits the interaction between PD-1 and PD-L1. PPL-C or an anti-PD-L1 antibody significantly reduced the rate of tumor mass development in mice compared to those given a control peptide (78% versus 77%, respectively). The results of this study demonstrate that PPL-C prevents or retards tumor growth. Further, immunotherapy with PPL-C enhances lymphocyte cytotoxicity and promotes proliferation in CT26-bearing mice.ConclusionPPL-C exhibited antitumor and immunoregulatory properties in the colon cancer. Therefore, PPL-C peptides of low molecular weight could serve as effective cancer immunotherapy.

CBX3 antagonizes IFNγ/STAT1/PD-L1 axis to modulate colon inflammation and CRC chemosensitivity.

As an important immune stimulator and modulator, IFNγ is crucial for gut homeostasis and its dysregulation links to diverse colon pathologies, such as colitis and colorectal cancer (CRC). Here, we demonstrated that the epigenetic regulator, CBX3 (also known as HP1γ) antagonizes IFNγ signaling in the colon epithelium by transcriptionally repressing two critical IFNγ-responsive genes: STAT1 and CD274 (encoding Programmed death-ligand 1, PD-L1). Accordingly, CBX3 deletion resulted in chronic mouse colon inflammation, accompanied by upregulated STAT1 and CD274 expressions. Chromatin immunoprecipitation indicated that CBX3 tethers to STAT1 and CD274 promoters to inhibit their expression. Reversely, IFNγ significantly reduces CBX3 binding to these promoters and primes gene expression. This antagonist effect between CBX3 and IFNγ on STAT1/PD-L1 expression was also observed in CRC. Strikingly, CBX3 deletion heightened CRC cells sensitivity to IFNγ, which ultimately enhanced their chemosensitivity under IFNγ stimulation in vitro with CRC cells and in vivo with a syngeneic mouse tumor model. Overall, this work reveals that by negatively tuning IFNγ-stimulated immune genes' transcription, CBX3 participates in modulating colon inflammatory response and CRC chemo-resistance.

Turning anecdotal irradiation-induced anticancer immune responses into reproducible in situ cancer vaccines via disulfiram/copper-mediated enhanced immunogenic cell death of breast cancer cells

Irradiation (IR) induces immunogenic cell death (ICD) in tumors, but it rarely leads to the abscopal effect (AE); even combining IR with immune checkpoint inhibitors has shown only anecdotal success in inducing AEs. In this study, we aimed to enhance the IR-induced immune response and generate reproducible AEs using the anti-alcoholism drug, disulfiram (DSF), complexed with copper (DSF/Cu) to induce tumor ICD. We measured ICD in vitro and in vivo. In mouse tumor models, DSF/Cu was injected intratumorally followed by localized tumor IR, creating an in situ cancer vaccine. We determined the anticancer response by primary tumor rejection and assessed systemic immune responses by tumor rechallenge and the occurrence of AEs relative to spontaneous lung metastasis. In addition, we analyzed immune cell subsets and quantified proinflammatory and immunosuppressive chemokines/cytokines in the tumor microenvironment (TME) and blood of the vaccinated mice. Immune cell depletion was investigated for its effects on the vaccine-induced anticancer response. The results showed that DSF/Cu and IR induced more potent ICD under hypoxia than normoxia in vitro. Low-dose intratumoral (i.t.) injection of DSF/Cu and IR(12Gy) demonstrated strong anti-primary and -rechallenged tumor effects and robust AEs in mouse models. These vaccinations also increased CD8+ and CD4+ cell numbers while decreasing Tregs and myeloid-derived suppressor cells in the 4T1 model, and increased CD8+, dendritic cells (DC), and decreased Treg cell numbers in the MCa-M3C model. Depleting both CD8+ and CD4+ cells abolished the vaccine’s anticancer response. Moreover, vaccinated tumor-bearing mice exhibited increased TNFα levels and reduced levels of immunosuppressive chemokines/cytokines. In conclusion, our novel approach generated an anticancer immune response that results in a lack of or low tumor incidence post-rechallenge and robust AEs, i.e., absence of or decreased spontaneous lung metastasis in tumor-bearing mice. This approach is readily translatable to clinical settings and may increase IR-induced AEs in cancer patients.

Catheter-Directed Ionic Liquid Embolic Agent for Rapid Portal Vein Embolization, Segmentectomy, and Bile Duct Ablation.

Embolic materials currently in use for portal vein embolization (PVE) do not treat the tumor, which poses a risk for tumor progression during the interval between PVE and surgical resection. Here, is developed an ionic-liquid-based embolic material (LEAD) for portal vein embolization, liver ablation, and drug delivery. LEAD is optimized and characterized for diffusivity, X-ray visibility, and cytotoxicity. In the porcine renal embolization model, LEAD delivered from the main renal artery reached vasculature down to 10 microns with uniform tissue ablation and delivery of small and large therapeutics. In non-survival and survival porcine experiments, successful PVE is achieved in minutes, leading to the expected chemical segmentectomy, and delivery of a large protein drug (i.e., Nivolumab) with LEAD. In cholangiocarcinoma mouse tumor models and in ex vivo human tumors, LEAD consistently achieved an effective ablation and wide drug distribution. Furthermore, various strains of drug-resistant patient-derived bacteria showed significant susceptibility to LEAD, suggesting that LEAD may also prevent infectious complications resulting from tissue ablation. With its capabilities to embolize, ablate, and deliver therapeutics, ease of use, and a high safety profile demonstrated in animal studies, LEAD offers a potential alternative to tumor ablation with or without PVE for FLR growth.

Ginsenoside Rh2 shifts tumor metabolism from aerobic glycolysis to oxidative phosphorylation through regulating the HIF1-α/PDK4 axis in non-small cell lung cancer

BackgroundGinsenoside Rh2 (G-Rh2), a steroidal compound extracted from roots of ginseng, has been extensively studied in tumor therapy. However, its specific regulatory mechanism in non-small cell lung cancer (NSCLC) is not well understood. Pyruvate dehydrogenase kinase 4 (PDK4), a central regulator of cellular energy metabolism, is highly expressed in various malignant tumors. We investigated the impact of G-Rh2 on the malignant progression of NSCLC and how it regulated PDK4 to influence tumor aerobic glycolysis and mitochondrial function.MethodWe examined the inhibitory effect of G-Rh2 on NSCLC through I proliferation assay, migration assay and flow cytometry in vitro. Subsequently, we verified the ability of G-Rh2 to inhibit tumor growth and metastasis by constructing subcutaneous tumor and metastasis models in nude mice. Proteomics analysis was conducted to analyze the action pathways of G-Rh2. Additionally, we assessed glycolysis and mitochondrial function using seahorse, PET-CT, Western blot, and RT-qPCR.ResultTreatment with G-Rh2 significantly inhibited tumor proliferation and migration ability both in vitro and in vivo. Furthermore, G-Rh2 inhibited the tumor’s aerobic glycolytic capacity, including glucose uptake and lactate production, through the HIF1-α/PDK4 pathway. Overexpression of PDK4 demonstrated that G-Rh2 targeted the inhibition of PDK4 expression, thereby restoring mitochondrial function, promoting reactive oxygen species (ROS) accumulation, and inducing apoptosis. When combined with sodium dichloroacetate, a PDK inhibitor, it complemented the inhibitory capacity of PDKs, acting synergistically as a detoxifier.ConclusionG-Rh2 could target and down-regulate the expression of HIF-1α, resulting in decreased expression of glycolytic enzymes and inhibition of aerobic glycolysis in tumors. Additionally, by directly targeting mitochondrial PDK, it elevated mitochondrial oxidative phosphorylation and enhanced ROS accumulation, thereby promoting tumor cells to undergo normal apoptotic processes.

Near-infrared photoimmunotherapy targeting PD-L1: Improved efficacy by preconditioning the tumor microenvironment.

Near-infrared photoimmunotherapy (NIR-PIT) is a new type of cancer therapy that employs antibody-IRDye700DX conjugates (AbPCs) and near-infrared (NIR) light at a wavelength of 689 nm, the excitation wavelength of IR700. Administered intravenously, injected AbPCs bind specifically to cells expressing the target antigen, whereupon NIR light exposure causes rapid, selective killing. This process induces an anticancer T cell response, leading to sustained anticancer host immune response. Programmed cell death ligand-1 (PD-L1) is a major inhibitory immune checkpoint molecule expressed in various cancers. In this study, we first assessed the efficacy of PD-L1-targeted NIR-PIT (αPD-L1-PIT) in immune-competent tumor mouse models. αPD-L1-PIT showed a significant therapeutic effect on the tumor models with high PD-L1 expression. Furthermore, αPD-L1-PIT induced an abscopal effect on distant tumors and long-term immunological memory. In contrast, αPD-L1-PIT was not as effective for tumor models with low PD-L1 expression. To improve the efficacy of PD-L1-targeted NIR-PIT, PEGylated interferon-gamma (IFNγ) was administered with αPD-L1-PIT. The combination therapy improved the treatment efficacy by increasing PD-L1 expression leading to more efficient cell killing by αPD-L1-PIT. Furthermore, the PEGylated IFNγ led to a CD8+ T cell-dominant tumor microenvironment (TME) with an enhanced anticancer T cell response after αPD-L1-PIT. As a result, even so-called cold tumors exhibited complete responses after αPD-L1-PIT. Thus, combination therapy of PEGylated IFNγ and PD-L1-targeted NIR-PIT has the potential to be an important future strategy for cancer immunotherapy.

Diagnostic Positron Emission Tomography Imaging with Zirconium-89 Desferrioxamine B Squaramide: From Bench to Bedside.

ConspectusMolecular imaging with antibodies radiolabeled with positron-emitting radionuclides combines the affinity and selectivity of antibodies with the sensitivity of Positron Emission Tomography (PET). PET imaging allows the visualization and quantification of the biodistribution of the injected radiolabeled antibody, which can be used to characterize specific biological interactions in individual patients. This characterization can provide information about the engagement of the antibody with a molecular target such as receptors present in elevated levels in tumors as well as providing insight into the distribution and clearance of the antibody. Potential applications of clinical PET with radiolabeled antibodies include identifying patients for targeted therapies, characterization of heterogeneous disease, and monitoring treatment response.Antibodies often take several days to clear from the blood pool and localize in tumors, so PET imaging with radiolabeled antibodies requires the use of a radionuclide with a similar radioactive half-life. Zirconium-89 is a positron-emitting radionuclide that has a radioactive half-life of 78 h and relatively low positron emission energy that is well suited to radiolabeling antibodies. It is essential that the zirconium-89 radionuclide be attached to the antibody through chemistry that provides an agent that is stable in vivo with respect to the dissociation of the radionuclide without compromising the biological activity of the antibody.This Account focuses on our research using a simple derivative of the bacterial siderophore desferrioxamine (DFO) with a squaramide ester functional group, DFO-squaramide (DFOSq), to link the chelator to antibodies. In our work, we produce conjugates with an average ∼4 chelators per antibody, and this does not compromise the binding of the antibody to the target. The resulting antibody conjugates of DFOSq are stable and can be easily radiolabeled with zirconium-89 in high radiochemical yields and purity. Automated methods for the radiolabeling of DFOSq-antibody conjugates have been developed to support multicenter clinical trials. Evaluation of several DFOSq conjugates with antibodies and low molecular weight targeting agents in tumor mouse models gave PET images with high tumor uptake and low background. The promising preclinical results supported the translation of this chemistry to human clinical trials using two different radiolabeled antibodies. The potential clinical impact of these ongoing clinical trials is discussed.The use of DFOSq to radiolabel relatively low molecular weight targeting molecules, peptides, and peptide mimetics is also presented. Low molecular weight molecules typically clear the blood pool and accumulate in target tissue more rapidly than antibodies, so they are usually radiolabeled with positron-emitting radionuclides with shorter radioactive half-lives such as fluorine-18 (t1/2 ∼ 110 min) or gallium-68 (t1/2 ∼ 68 min). Radiolabeling peptides and peptide mimetics with zirconium-89, with its longer radioactive half-life (t1/2 = 78 h), could facilitate the centralized manufacture and distribution of radiolabeled tracers. In addition, the ability to image patients at later time points with zirconium-89 based agents (e.g. 4-24 h after injection) may also allow the delineation of small or low-uptake disease sites as the delayed imaging results in increased clearance of the tracer from nontarget tissue and lower background signal.

TLR3 activation enhances abscopal effect of radiotherapy in HCC by promoting tumor ferroptosis.

Radiotherapy (RT) has been reported to induce abscopal effect in advanced hepatocellular carcinoma (HCC), but such phenomenon was only observed in sporadic cases. Here, we demonstrated that subcutaneous administration of Toll-like receptor 3 (TLR3) agonist poly(I:C) could strengthen the abscopal effect during RT through activating tumor cell ferroptosis signals in bilateral HCC subcutaneous tumor mouse models, which could be significantly abolished by TLR3 knock-out or ferroptosis inhibitor ferrostatin-1. Moreover, poly(I:C) could promote the presentation of tumor neoantigens by dendritic cells to enhance the recruitment of activated CD8+ T cells into distant tumor tissues for inducing tumor cell ferroptosis during RT treatment. Finally, the safety and feasibility of combining poly(I:C) with RT for treating advanced HCC patients were further verified in a prospective clinical trial. Thus, enhancing TLR3 signaling activation during RT could provide a novel strategy for strengthening abscopal effect to improve the clinical benefits of advanced HCC patients.

A dietary commensal microbe enhances antitumor immunity by activating tumor macrophages to sequester iron.

Innate immune cells generate a multifaceted antitumor immune response, including the conservation of essential nutrients such as iron. These cells can be modulated by commensal bacteria; however, identifying and understanding how this occurs is a challenge. Here we show that the food commensal Lactiplantibacillus plantarum IMB19 augments antitumor immunity in syngeneic and xenograft mouse tumor models. Its capsular heteropolysaccharide is the major effector molecule, functioning as a ligand for TLR2. In a two-pronged manner, it skews tumor-associated macrophages to a classically active phenotype, leading to generation of a sustained CD8+ T cell response, and triggers macrophage 'nutritional immunity' to deploy the high-affinity iron transporter lipocalin-2 for capturing and sequestering iron in the tumor microenvironment. This process induces a cycle of tumor cell death, epitope expansion and subsequent tumor clearance. Together these data indicate that food commensals might be identified and developed into 'oncobiotics' for a multi-layered approach to cancer therapy.