Reduced Tumor Burden Research Articles

ICOS-expressing Regulatory T Cells Influence the Composition of Antitumor CTL Populations.

The role of ICOS in antitumor T cell responses and overall tumor progression has been controversial. In this study, we compared tumor progression in mice lacking ICOS selectively in regulatory T (Treg) cells or in all T cells. Using an experimental melanoma lung metastasis model, we found that Treg cell-specific ICOS knockout reduces the overall tumor burden compared with Cre control mice, with increased CD4+-to-Treg cell and CD8+-to-Treg cell ratios in the tumor. In contrast, there was no difference in the tumor burden in mice lacking ICOS in all of the T cell compartments. This suggests a dual role of ICOS costimulation in promoting protumor and antitumor T cell responses. Consistent with reduced tumor burden, we found that Treg cell-specific deletion of ICOS leads to an increase of CD8+ CTLs that express high levels of granzyme B and perforin. Moreover, single-cell transcriptome analysis revealed an increase of Ly108+Eomeshi CD8+ T cells at the cost of the Ly108+T-bethi subset in Treg cell-specific knockout mice. These results suggest that ICOS-expressing Treg cells suppress the CTL maturation process at the level of Eomes upregulation, a critical step known to drive perforin expression and cytotoxicity. Collectively, our data imply that cancer immunotherapies using ICOS agonist Abs may work better in Treg cell-low tumors or when they are combined with regimens that deplete tumor-infiltrating Treg cells.

Sonidegib reduced tumor burden in patients with advanced basal cell carcinoma in the BOLT trial: Long-term analysis results

Sonidegib reduced tumor burden in patients with advanced basal cell carcinoma in the BOLT trial: Long-term analysis results

Towards Understanding Tumour Colonisation by Probiotic Bacterium E. coli Nissle 1917.

The last decade has seen a rapid increase in studies utilising a genetically modified probiotic, Escherichia coli Nissle 1917 (EcN), as a chassis for cancer treatment and detection. This approach relies on the ability of EcN to home to and selectively colonise tumours over normal tissue, a characteristic common to some bacteria that is thought to result from the low-oxygen, nutrient-rich and immune-privileged niche the tumour provides. Pre-clinical studies have used genetically modified EcN to deliver therapeutic payloads that show efficacy in reducing tumour burden as a result of high-tumour and low off-target colonisation. Most recently, the EcN chassis has been expanded into an effective tumour-detection tool. These advances provide strong justification for the movement of genetically modified EcN into clinical oncology trials. What is currently unknown in the field is a deep mechanistic understanding of how EcN distributes to and localises within tumours. This review summarises the existing EcN literature, with the inclusion of research undertaken with other tumour-homing and pathogenic bacteria, to provide insights into possible mechanisms of EcN tumour homing for future validation. Understanding exactly how and why EcN colonises neoplastic tissue will inform the design and testing of the next generation of EcN chassis strains to address biosafety and containment concerns and optimise the detection and treatment of cancer.

Osteopontin Regulates Treg Cell Stability and Function with Implications for Anti-Tumor Immunity and Autoimmunity.

Foxp3-expressing regulatory T (Treg) cells represent the most highly immunosuppressive cell in the tumor microenvironment (TME) that halts effective anti-tumor immunity. Osteopontin (Opn), an extracellular matrix (ECM) glycophosphoprotein, plays key roles in many types of immune-related diseases and is associated with cancer aggressiveness when expressed by tumor cells. However, its role in Foxp3Treg heterogeneity, function, and stability in the TME is poorly defined. We generated mice with a Foxp3-specific deletion of Opn and assessed the ability of Opn-deficient Tregs to suppress inflammation. As these mice aged, they developed a scurfy-like syndrome characterized by aberrant and excessive activation of effector T cells. We evaluated and further confirmed the reduced suppressive capacity of Opn-deficient Tregs in an in vivo suppression assay of colitis. We also found that mice with Opn-deficient Foxp3+ Tregs have enhanced anti-tumor immunity and reduced tumor burden, associated with an unstable Treg phenotype, paralleled by reduced Foxp3 expression in tumor-infiltrating lymphocytes. Finally, we observed reduced Foxp3 and Helios expression in Opn-deficient Tregs compared to wild-type controls after in vitro activation. Our findings indicate that targeting Opn in Tregs reveals vigorous and effective ways of promoting Treg instability and dysfunction in the TME, facilitating anti-tumor immunity.

Novel immunotherapeutics against LGR5 to target multiple cancer types

We have developed and validated a highly specific, versatile antibody to the extracellular domain of human LGR5 (α-LGR5). α-LGR5 detects LGR5 overexpression in >90% of colorectal cancer (CRC), hepatocellular carcinoma (HCC) and pre-B-ALL tumour cells and was used to generate an Antibody-Drug Conjugate (α-LGR5-ADC), Bispecific T-cell Engager (α-LGR5-BiTE) and Chimeric Antigen Receptor (α-LGR5-CAR). α-LGR5-ADC was the most effective modality for targeting LGR5+ cancer cells in vitro and demonstrated potent anti-tumour efficacy in a murine model of human NALM6 pre-B-ALL driving tumour attrition to less than 1% of control treatment. α-LGR5-BiTE treatment was less effective in the pre-B-ALL cancer model yet promoted a twofold reduction in tumour burden. α-LGR5-CAR-T cells also showed specific and potent LGR5+ cancer cell killing in vitro and effective tumour targeting with a fourfold decrease in pre-B-ALL tumour burden relative to controls. Taken together, we show that α-LGR5 can not only be used as a research tool and a biomarker but also provides a versatile building block for a highly effective immune therapeutic portfolio targeting a range of LGR5-expressing cancer cells.

ORY-1001 inhibits glioblastoma cell growth by downregulating the Notch/HES1 pathway via suppressing lysine-specific demethylase 1 expression

To explore the inhibitory effect ORY-1001, a lysine-specific histone demethylase 1 (LSD1) inhibitor, on growth of glioblastoma (GBM) and the underlying mechanism. We analyzed LSD1 expressions in GBM and normal brain tissues based on data from TCGA and HPA databases. Female BALB/c mouse models bearing xenografts derived from U87 cells or cells with lentivirus-mediated LSD1 silencing or Notch overexpression were treated with saline or 400 µg/kg ORY-1001 by gavage every 7 days, and GBM formation and survival time of the mice were recorded. The effect of ORY-1001 on GBM cell viability was assessed, and its effect on LSD1 expression was analyzed with Western blotting. The genes and pathways associated with LSD1 were analyzed using bioinformatics methods. Western blotting and qRT-PCR were used to detect Notch/HES1 pathway expression after LSD1 silencing and ORY-1001 treatment. The impact of ORY-1001 on viability of U87 cells with Notch1 silencing or overexpression was assessed, and the regulatory effects of ORY-1001 on Notch/HES1 pathway were analyzed using chromatin immunoprecipitation assay. A high expression of LSD1 in GBM was negatively correlated with patient survival (P < 0.001). ORY-1001 and LSD1 silencing obviously reduced tumor burden and prolonged the survival time of GBM-bearing mice. ORY-1001 treatment significantly inhibited the viability and dose-dependently decreased LSD1 expression in GBM cells, and such inhibitory effect of ORY-1001 was attenuated by LSD1 silencing. The Notch pathway enriched the differential genes related to LSD1, and Notch/HES1 pathway expression was significantly down-regulated after LSD1 silencing and ORY-1001 treatment. Notch1 overexpression significantly attenuated the anti-tumor effect of ORY-1001 on GBM. Mechanistically, ORY-1001 disrupted the interaction between LSD1 and the Notch pathway target genes including Notch3, HES1 and CR2. ORY-1001 down-regulates the Notch/HES1 pathway by inhibiting LSD1 expression to suppress the growth of GBM in mice.

Irreversible Electroporation has More Synergistic Effect with Anti‐PD‐1 Immunotherapy than Thermal Ablation or Cryoablation, in a Colorectal Cancer Model

AbstractBoosting the response rate of immune checkpoint blockade (ICB) therapy to improve treatment efficacy is a primary goal in cancer immunotherapy. One of the promising approaches involves focal tumor ablation to reduce tumor burden and trigger the in situ vaccination. Even though this combination strategy has demonstrated enhanced therapeutic outcomes in both preclinical research and clinical trials, limited research has comparatively investigated diverse ablation techniques. The optimal choice among focal therapy techniques remains largely unknown. In a murine colorectal cancer model (MC‐38), the therapeutic efficacy of anti‐PD‐1 in combination with thermal ablation, cryoablation, and irreversible electroporation (IRE) is evaluated, utilizing well‐characterized miniature probes. In this model, ICB monotherapy has limited effect in controlling tumor growth. IRE exhibits the most favorable synergistic effect with anti‐PD‐1 immunotherapy than thermal ablation or cryoablation, leading to the greatest primary tumor growth delay, longest tumor‐free survival, and highest protection against secondary tumor challenge. Furthermore, the co‐administration of IRE and anti‐PD‐1 significantly fosters the infiltration of CD8+ T cells into the tumor coupled with a remarkable stem‐like progenitor phenotype. The findings demonstrate that IRE stands as a promising modality that can potentiate the antitumor efficacy when the tumor is poorly responding to ICB monotherapy.

The CD47/TSP-1 axis: a promising avenue for ovarian cancer treatment and biomarker research

BackgroundOvarian cancer (OC) remains one of the most challenging and deadly malignancies facing women today. While PARP inhibitors (PARPis) have transformed the treatment landscape for women with advanced OC, many patients will relapse and the PARPi-resistant setting is an area of unmet medical need. Traditional immunotherapies targeting PD-1/PD-L1 have failed to show any benefit in OC. The CD47/TSP-1 axis may be relevant in OC. We aimed to describe changes in CD47 expression with platinum therapy and their relationship with immune features and prognosis.MethodsTumor and blood samples collected from OC patients in the CHIVA trial were assessed for CD47 and TSP-1 before and after neoadjuvant chemotherapy (NACT) and multiplex analysis was used to investigate immune markers. Considering the therapeutic relevance of targeting the CD47/TSP-1 axis, we used the CD47-derived TAX2 peptide to selectively antagonize it in a preclinical model of aggressive ovarian carcinoma.ResultsSignificant reductions in CD47 expression were observed post NACT. Tumor patients having the highest CD47 expression profile at baseline showed the greatest CD4+ and CD8+ T-cell influx post NACT and displayed a better prognosis. In addition, TSP-1 plasma levels decreased significantly under NACT, and high TSP-1 was associated with a worse prognosis. We demonstrated that TAX2 exhibited a selective and favorable biodistribution profile in mice, localizing at the tumor sites. Using a relevant peritoneal carcinomatosis model displaying PARPi resistance, we demonstrated that post-olaparib (post-PARPi) administration of TAX2 significantly reduced tumor burden and prolonged survival. Remarkably, TAX2 used sequentially was also able to increase animal survival even under treatment conditions allowing olaparib efficacy.ConclusionsOur study thus (1) proposes a CD47-based stratification of patients who may be most likely to benefit from postoperative immunotherapy, and (2) suggests that TAX2 is a potential alternative therapy for patients relapsing on PARP inhibitors.

Berberine Protects against Hepatocellular Carcinoma Progression by Regulating Intrahepatic T Cell Heterogeneity.

Accumulating evidence suggests that berberine (BBR) exhibits anti-cancer effects in hepatocellular carcinoma (HCC). However, the mechanisms by which BBR regulates the immunological microenvironment in HCC has not been fully elucidated. In this study, a mouse model of orthotopic HCC is established and treated with varying doses of BBR. BBR showed effectiveness in reducing tumor burden in mice with HCC. Cytometry by time-of-flight depicted the alterations in the tumor immune landscape following BBR treatment, revealing the enhancement in the T lymphocytes effector function. In particular, BBR decreased the proportion of TCRbhiPD-1hiCD69+CD27+ effector CD8+ T lymphocytes and increased the proportion of Ly6ChiTCRb+CD69+CD27+CD62L+ central memory CD8+ T lymphocytes. Single-cell RNA sequencing further elucidates the effects of BBR on transcriptional profiles of liver immune cells and confirms the phenotypical heterogeneity of T lymphocytes in HCC immune microenvironment. Additionally, it is found that BBR potentially regulated the antitumor immunity in HCC by modulating the receptor-ligand interaction among immune cells mediated by cytokines. In summary, the findings improve the understanding of BBR's impact on protecting against HCC, emphasizing BBR's role in regulating intrahepatic T cell heterogeneity. BBR has the potential to be a promising therapeutic strategy to hinder the advancement of HCC.

Local Control, Survival, and Toxicity Outcomes with High-Dose-Rate Peri-Operative Interventional Radiotherapy (Brachytherapy) in Head and Neck Cancers: A Systematic Review.

Background. Peri-operative interventional radiotherapy (POIRT) entails tumor resection, catheter implantation in the same surgery, and irradiation within the peri-operative period. It allows for maximal tumor burden reduction, better tumor bed identification, more flexible implant geometry, highly conformal irradiation, and treatment delay minimization. We reviewed the published local control, survival, toxicity, and quality of life (QOL) outcomes with POIRT for head and neck cancers (HNCs) in primary and re-irradiation settings. Materials and Methods. A systematic search of PubMed, Scopus, Science Direct, and other databases, supplemented by bibliography scanning and hand-searching, yielded 107 titles. Fifteen unique articles were eligible, five of which were merged with more updated studies. Of the ten remaining studies, four reported on primary POIRT, and seven reported on reirradiation POIRT. Given data heterogeneity, only qualitative synthesis was performed. Results. Primary POIRT in early tongue cancer results in 6-year recurrence-free (RFS) and overall survival (OS) of 92% for both; in advanced HNCs, the 9-year RFS and OS rates are 52% and 55%. Grade 1-2 toxicity is very common; grade 3-4 toxicity is rare, but grade 5 toxicity has been reported. POIRT re-irradiation for recurrent HNCs results in 5y RFS and OS rates of 37-55% and 17-50%; better outcomes are achieved with gross total resection (GTR). QOL data are lacking. Conclusions. Primary POIRT is safe and effective in early tongue cancers; its use in other HNC sites, especially in advanced disease, requires careful consideration. Re-irradiation POIRT is most effective and safe when combined with GTR; toxicity is significant and may be limited by careful case selection, implant planning and execution, use of smaller fraction sizes, and adherence to homogeneity constraints. Study Registration Number. PROSPERO Registry Number CRD42024548294.

Use of a novel proteomimetic nanoplatform for simultaneous delivery of antigens with adjuvants to impact tumor growth in multiple tumor models.

40 Background: Patient-specific cancer vaccines derived from tumor antigen have been explored as a promising therapeutic strategy, however, challenges delivering vaccine components in a coordinated fashion to elicit antitumor responses remain. To overcome these, we utilize a novel nanoplatform called the Protein-Like Polymer (PLP), which allows for sustained and targeted delivery of tumor antigens in conjunction with adjuvants. Methods: PLPs containing peptide antigens were synthesized via ROMP and characterized. A library of compounds with different sidechain linkage chemistries, degrees of polymerization (DP), and inclusion/exclusion of Oligo-ethylene glycol (OEG) were made to determine design rules for immune activation. Cell uptake and functional assays using payload-specific T Cells were conducted. Immunization in three independent tumor models was done to show generalizability. Ability of PLPs to co-deliver adjuvants was tested by electrostatically coupling small molecule STING agonist, 2’3’ cGAMP. Results: Conjugating antigens to the polymer via a cleavable disulfide linkage, which reduces intracellularly in APCs, resulted in increased endosomal localization, higher levels of induced T cell proliferation, cytokine production, and expression of activation markers in CTLs and APCs. Incorporating a diluent amount of OEG side chains reduced enzymatic degradation while increasing immunogenicity and uptake. Additionally, increasing the DP, and therefore the density of antigen side chains, further improved vaccine efficacy and resistance to proteolysis. Antigen-PLP conjugates enhanced dendritic cell activation and T-cell response only when paired with cells from their cognate system, with no activity in immune cells not expressing receptors for the payload demonstrating antigen-specificity. Mice bearing established B16F10, MC38, or TC-1 tumors treated with PLPs containing gp100, adpgk, or E7 respectively all showed increased survival times, reduced tumor burden with corresponding changes in immune cell profiles, and immunological memory upon rechallenge. Impressively, mice treated with STING-PLP complexes had significantly smaller tumors vs control at day 14 (0.038g vs 0.76g; p &lt; 0.0001) and allowed for subcutaneous administration of 2’3’ cGAMP, which traditionally requires intratumoral injection. Studies on the effects of vaccinating with pools of neoantigens multiplexed onto one PLP are ongoing. Conclusions: This work validates the ability of PLPs to overcome major limitations in cancer vaccine development. The modularity of the platform allows for complex nano-architectures including systems capable of delivering challenging compounds, ie small molecule STING agonists, subcutaneously through electrostatic coupling, highlighting its potential to revolutionize cancer vaccinology.

Surface Modified Glucose‐Derived, Blood–Brain Barrier‐Crossing Nanospheres Dually Targets Macrophage and Cancer Cells for Effective In Situ Anti‐Glioma Effect

AbstractGlucose‐derived carbon nanospheres (CSP), uniquely derived by hydrothermal condensation process, inherently cross blood–brain‐barrier (BBB) but distribute all over the brain. Albeit its potential to treat glioma as an effective drug delivery system, it is challenging to restrict drug‐associated CSP within the glioma region and reduce non‐specific side effects. Incidentally, gliomas moderately express sigma receptors (SR). Earlier, a cationic lipid‐conjugated neuropsychotic drug, haloperidol (H8) is developed with SR‐targetability and anticancer effect but with zero BBB‐crossing ability. In this study, the CSP surface is modified with H8 (CH8 nano‐conjugate) and dual targeting is achieved within glioma‐tumor microenvironment: 1) glioma cells and 2) pro‐proliferative M2 tumor‐associated macrophages (TAM), as both express SR. CH8‐treatment increases the survivability of orthotopic glioma‐tumor bearing mice and significantly reduces tumor burden in the glioma‐subcutaneous model. Further CH8‐surface is modified by combining the brain tumor drug, carmustine (CH8‐CRM). CH8‐CRM nano‐conjugate selectively enhances the survivability of orthotopic glioma‐carrying mice and reduces tumor aggressiveness significantly in comparison to other treatment groups. Lysates from CH8‐CRM‐treated tumor show upregulation of cleaved‐caspase 3, p53, but downregulation of pAkt. The combination treatment pronouncedly enhances the anti‐glioma effect of H8. Conclusively, CH8‐mediated dual‐targeting via SR within orthotopic glioma‐associated mice exemplifies the repurposing of neuropsychotic drugs for treating glioma.

Traversing the bench to bedside journey for iNKT cell therapies.

Invariant natural killer T (iNKT) cells are immune cells that harness properties of both the innate and adaptive immune system and exert multiple functions critical for the control of various diseases. Prevention of graft-versus-host disease (GVHD) by iNKT cells has been demonstrated in mouse models and in correlative human studies in which high iNKT cell content in the donor graft is associated with reduced GVHD in the setting of allogeneic hematopoietic stem cell transplants. This suggests that approaches to increase the number of iNKT cells in the setting of an allogeneic transplant may reduce GVHD. iNKT cells can also induce cytolysis of tumor cells, and murine experiments demonstrate that activating iNKT cells in vivo or treating mice with ex vivo expanded iNKT cells can reduce tumor burden. More recently, research has focused on testing anti-tumor efficacy of iNKT cells genetically modified to express a chimeric antigen receptor (CAR) protein (CAR-iNKT) cells to enhance iNKT cell tumor killing. Further, several of these approaches are now being tested in clinical trials, with strong safety signals demonstrated, though efficacy remains to be established following these early phase clinical trials. Here we review the progress in the field relating to role of iNKT cells in GVHD prevention and anti- cancer efficacy. Although the iNKT field is progressing at an exciting rate, there is much to learn regarding iNKT cell subset immunophenotype and functional relationships, optimal ex vivo expansion approaches, ideal treatment protocols, need for cytokine support, and rejection risk of iNKT cells in the allogeneic setting.

67 Preclinical evaluation of PSMA-based68Ga-/225Ac-labeled radiotheranostic pair in a syngeneic mouse model of renal cell carcinoma

Abstract Background Despite the significant progress achieved with PD-1/PD-L1 inhibitors in the treatment of metastatic renal cell carcinoma (mRCC), most patients ultimately progress. Targeted radiotheranostics offer a new potential approach. Although a radiotheranostic platform targeting the prostate-specific membrane antigen (PSMA) has been tested in mRCC in patients preliminarily, thorough preclinical optimization has not been reported. Prostate-specific membrane antigen (PSMA) is overexpressed in tumor-associated neovascular endothelial cells of many solid tumors, including metastatic RCC. Furthermore, radiopharmaceutical therapy using β- and α-particle emitting agents causes immunomodulation by inducing immunogenic cell death, and release of tumor-associated antigens, potentially enhancing inflammatory phenotype. Here, we investigated whether PSMA-based radiotheranostics can be utilized to improve the efficacy of PD-1 therapy. Methods The PSMA+ RENCA model was developed by lentiviral transduction of RENCA (wt) cells and then characterized for basal and IFN-g induced PD-L1 expression. 68Ga-L1 and 225Ac-L1 were synthesized in high radiochemical yield and purity following our reported methods. Male and female BALB/c mice were used for tumor inoculation. 68Ga-L1 was evaluated in small animal PET/CT imaging in flank and PET/MR imaging in orthotopic implantation. A treatment study was conducted to assess the effect of combination therapy in seven groups in the flank tumors at 2 weeks post-inoculation: Control (saline); PD-1 (10 mg/kg); Anti-PD-1 (10 mg/kg)+axitinib (tyrosine kinase inhibitor, 5 mg/kg, oral gavage, for five days/wk); 225Ac-L1 (37 kBq); 225Ac-L1 (2×37 kBq, 1 wk apart); [225Ac-L1 (37 kBq)+PD-1 (10 mg/kg) and [225Ac-L1 2×37 kBq)+PD-1 (10 mg/kg)]. Therapeutic efficacy was assessed by tumor weight and time to progression of tumor volume doubling (TVD). To determine the mechanism of action of the 225Ac-L1/anti-PD-1 combination treatment, tumor-infiltrating lymphoid populations from tumor samples were collected at day 30, and Fluorescence-Activated Cell Sorting analysis was done with fluorochrome-labeled antibodies against CD45, CD3, CD8, IL10, and IL12. Results 68Ga-L1 and 225Ac-L1 confirmed 10-fold and 2-fold higher uptake, respectively, in the PSMA+ RENCA cells compared to RENCA (wt) cells. PET imaging in the flank model displayed ~7-fold higher accumulation of 68Ga-L1 in PSMA+ RENCA than the RENCA (wt). Two-fold higher accumulation of 68Ga-L1 was observed in orthotopic tumors than the normal kidneys during 1-3 h post-injection. Significant lung metastases were detected with 68Ga-L1 PET at 3 weeks in mice with orthotopic tumors. A combination therapy study was conducted using anti-PD-1 and anti-PD-1+axitinib and compared the efficacy with 225Ac-L1 as a single agent (37 kBq and 2×37 kBq, 1 wk apart) and in combination with PD-1. Median TVD increased from 12 d (control) to 16 d (anti-PD-1), 16 d (anti-PD-1+axitinib), 24 d [225Ac-L1 (37 kBq) P&amp;lt;0.001], 24 d [225Ac-L1 (2 × 37 kBq) P&amp;lt;0.0001}, 30 d [anti-PD-1+225Ac-L1 (1×37 kBq) P&amp;lt;0.0001], and undefined, [anti-PD-1+225Ac-L1 2×37 kBq), P&amp;lt;0.0001], respectively. Furthermore, treatment with 225Ac-L1 (2×37 kBq, 1 wk) resulted in a significant lowering of tumor growth (P&amp;lt; 0.01) compared to control, whereas anti-PD-1 (vs. control) alone moderately reduced tumor growth. The combination of the treatment of [PD-1+225Ac-L1 (2×37 kBq), P=0.0001] was the most effective in enhancing tumor growth inhibition compared with the PD-1+axitinib group. Flow cytometry of tumor-infiltrating immune cells of the treatment groups PD-1+225Ac-L1(37 kBq) and PD-1+225Ac-L1 (2×37 kBq) revealed a higher proportion of effector CD3+CD8+ T cells, accompanied by a significant decline in the proportion of immunosuppressive and pro-tumoral CD8+IL10+ T cells and increase in antitumor CD8+IL12+ T cells compared to untreated and treatment control groups (PD-1 or PD-1+axitinib groups). Conclusions Combining radiotheranostic platform, 68Ga-L1/225Ac-L1 with PD-1 therapy reduces tumor burden and improves TVD in a syngeic model of RCC. This is a promising option for metastatic RCC patients with low and heterogeneous PSMA expression. Translation of this method will be pursued actively. DOD CDMRP Funding: yes

Enhancing outcome prediction of concurrent chemoradiation treatment in patients with locally advanced cervical cancer through plasma extracellular vesicle proteomics

Most patients with locally advanced cervical cancer (LACC) are primarily treated using concurrent chemoradiation (CCRT); however, LACC lacks reliable predictive biomarkers. Extracellular vesicles (EVs) could define the dynamic biological response to CCRT. However, the relationship between EVs and the therapeutic response to LACC is unestablished. Thus, we aimed to determine the relationship of plasma EVs pre- and post-CCRT in 62 patients with LACC. For proteomic analyses, EVs were isolated using ultracentrifugation (UC) with size exclusion chromatography or UC alone. We found that plasma particle concentration was significantly increased post-treatment in non-responders. After CCRT, there was a decrease in proteins related to serine protease and fibrinogen, which contribute to tumor microenvironment alteration. This reduction also extended to proteins involved in innate immune and viral immune responses, correlating with reduced tumor burden. Sparse partial least squares discriminant analysis revealed 8, 13, and 19 proteins at diagnosis, one month, and three months, respectively, influencing the CCRT response. Among these, FIBG, TFR1, HBA, and FINC are prognostic markers according to The Cancer Genome Atlas tissue gene expression database. Our discriminant model demonstrated excellent specificity and negative predictive value, underscoring the model's reliability in determining responsiveness to CCRT and highlighting the potential clinical applicability of EVs in improving outcomes in LACC.

Delivery of a STING Agonist Using Lipid Nanoparticles Inhibits Pancreatic Cancer Growth.

The tumor microenvironment (TME) of pancreatic cancer is highly immunosuppressive and characterized by a large number of cancer-associated fibroblasts, myeloid-derived suppressor cells, and regulatory T cells. Stimulator of interferon genes (STING) is an endoplasmic reticulum receptor that plays a critical role in immunity. STING agonists have demonstrated the ability to inflame the TME, reduce tumor burden, and confer anti-tumor activity in mouse models. 2'3' cyclic guanosine monophosphate adenosine monophosphate (2'3'-cGAMP) is a high-affinity endogenous ligand of STING. However, delivering cGAMP to antigen-presenting cells and tumor cells within the cytosol remains challenging due to membrane impermeability and poor stability. In this study, we encapsulated 2'3'-cGAMP in a lipid nanoparticle (cGAMP-LNP) designed for efficient cellular delivery. We assessed the properties of the nanoparticles using a series of in-vitro studies designed to evaluate their cellular uptake, cytosolic release, and minimal cytotoxicity. Furthermore, we examined the nanoparticle's anti-tumor effect in a syngeneic mouse model of pancreatic cancer. The lipid platform significantly increased the cellular uptake of 2'3'-cGAMP. cGAMP-LNP exhibited promising antitumor activity in the syngeneic mouse model of pancreatic cancer. The LNP platform shows promise for delivering exogenous 2'3'-cGAMP or its derivatives in cancer therapy.

AB001. Development of tumour-targeted therapy for the treatment of adult and paediatric high-grade gliomas.

Brain cancer patients, especially those suffering from high-grade gliomas (HGGs) face a bleak future with very dismal long-term disease-free survival outcomes due to the limited treatment options currently available. Therefore, there is an unmet need for new therapeutic intervention that extends patients' progress-free survival and improves their quality of life. A significant hurdle is the inability of current chemotherapy agents to cross the blood-brain barrier (BBB). BBB acts as a protective shield that filters the blood to ensure nothing harmful makes it to the brain. This protection is usually good, but it becomes a problem if you want to deliver therapeutic cancer drugs through it. This barrier blocks 98% of drugs from entering the brain. Even the ones that cross BBB are unevenly distributed in the normal brain and tumour tissue, resulting in mediocre treatment and severe side effects. We are developing drug delivery systems that can cross the BBB and facilitate the specific accumulation of drugs in the tumour tissue. This will significantly improve the efficacy of anticancer drugs in treating various brain cancers and reduce systemic toxicity. Our group has explored and developed BBB crossing and tumour targeting near infra-red dyes, which can be covalently attached to Food and Drug Administration (FDA)-approved chemotherapy agents (drug-dye conjugates), thereby delivering it to the tumour tissue. We synthesized such drug-dye conjugates to target various aberrant pathways in HGG and tested these conjugates against patient-derived HGG cell lines. One such conjugate was tested on a mouse model of glioblastoma, an aggressive form of HGG, and shown to cross the BBB and specifically accumulate in tumour tissue, bringing forth tumour burden reduction. The results obtained from this work serve as proof of principle that enables tumour-specific drug delivery to treat HGG. This work also paves the way for treating other brain cancers and central nervous system (CNS) disorders like Parkinson's and Alzheimer's disease, for which no adequate therapy exists.

Complement C3d enables protective immunity capable of distinguishing spontaneously transformed from non-transformed cells.

We show that intracellular soluble fragment 3d of complement (C3d) induces regression of spontaneous multiple myeloma in mice reducing tumor burden by 10 fold, after 8 weeks. C3d enables cell-mediated immunity to target multiple myeloma clones sparing non-transformed polyclonal B cells and plasma cells with lower mutation loads. We show that C3d increases the expression of ribosomal subunits associated with the translation of defective ribosomal products (DRiPs). C3d also decreases expression of protein arginine methyl transferase (PRMT) 5 which in turn relieves E2f1 repression increasing the expression of Lnc RNAs and derived peptides that evoke anti-tumor cellular immunity. The approach increases MHC-I expression by tumor cells and generates a CMI response that overcomes tumor immune-evasion strategies. Tumors are immunogenic in part because of somatic mutations that originate novel peptides that once presented on MHC engage cell-mediated immunity (CMI). However, in spite of the higher mutation load most tumors evade immunity. We discovered that a component of the complement system (C3d) overcomes tumor immune evasion by augmenting expression of ribosomal proteins and lncRNAs linked to the presentation of novel peptides by tumor cells. C3d induced CMI targets cancer cells sparing non transformed cells uncovering a novel function for complement in immune surveillance.

Longitudinal Intravascular Antibody Labeling Identified Regulatory T Cell Recruitment as a Therapeutic Target in a Mouse Model of Lung Cancer.

Anticancer immunity is predicated on leukocyte migration into tumors. Once recruited, leukocytes undergo substantial reprogramming to adapt to the tumor microenvironment. A major challenge in the field is distinguishing recently recruited from resident leukocytes in tumors. In this study, we developed an intravascular Ab technique to label circulating mouse leukocytes before they migrate to tissues, providing unprecedented insight into the kinetics of recruitment. This approach unveiled the substantial role of leukocyte migration in tumor progression using a preclinical mouse model of lung adenocarcinoma. Regulatory T cells (Tregs), critical mediators of immunosuppression, were continuously and rapidly recruited into tumors throughout cancer progression. Moreover, leukocyte trafficking depended on the integrins CD11a/CD49d, and CD11a/CD49d blockade led to significant tumor burden reduction in mice. Importantly, preventing circulating Treg recruitment through depletion or sequestration in lymph nodes was sufficient to decrease tumor burden, indicating that Treg migration was crucial for suppressing antitumor immunity. These findings underscore the dynamic nature of the immune compartment within mouse lung tumors and demonstrate the relevance of a temporal map of leukocyte recruitment into tumors, thereby advancing our understanding of leukocyte migration in the context of tumor development.

MS-20 enhances the gut microbiota-associated antitumor effects of anti-PD1 antibody

ABSTRACT Cancer immunotherapy has been regarded as a promising strategy for cancer therapy by blocking immune checkpoints and evoking immunity to fight cancer, but its efficacy seems to be heterogeneous among patients. Manipulating the gut microbiota is a potential strategy for enhancing the efficacy of immunotherapy. Here, we report that MS-20, also known as “Symbiota®”, a postbiotic that comprises abundant microbial metabolites generated from a soybean-based medium fermented with multiple strains of probiotics and yeast, inhibited colon and lung cancer growth in combination with an anti-programmed cell death 1 (PD1) antibody in xenograft mouse models. Mechanistically, MS-20 remodeled the immunological tumor microenvironment by increasing effector CD8+ T cells and downregulating PD1 expression, which were mediated by the gut microbiota. Fecal microbiota transplantation (FMT) from mice receiving MS-20 treatment to recipient mice increased CD8+ T-cell infiltration into the tumor microenvironment and significantly improved antitumor activity when combined with anti-PD1 therapy. Notably, the abundance of Ruminococcus bromii, which increased following MS-20 treatment, was positively associated with a reduced tumor burden and CD8+ T-cell infiltration in vivo. Furthermore, an ex vivo study revealed that MS-20 could alter the composition of the microbiota in cancer patients, resulting in distinct metabolic pathways associated with favorable responses to immunotherapy. Overall, MS-20 could act as a promising adjuvant agent for enhancing the efficacy of immune checkpoint-mediated antitumor therapy.