Ad-CD40L mobilizes CD4 T cells for the treatment of brainstem tumors

Unleashing the therapeutic potential of tumor-draining lymph nodes: spotlight on bladder cancer

Tumor-draining lymph nodes (TDLNs) are often involved during the metastasis of bladder cancer (BC), which is associated with a poor prognosis. Recent studies have shown that TDLNs are a major source of host anti-tumor immunity, which can impede tumor progression and favor tumor immunotherapy. However, during tumor progression, various tumor-derived mediators modulate the TDLN microenvironment, impairing their protective function. Ultimately, TDLNs provide the soil for the proliferation and dissemination of tumor cells. Therefore, surgical removal of TDLNs is commonly recommended in various solid tumors to prevent metastasis, but this poses significant challenges for leveraging TDLNs in immunotherapy. Additionally, lymph node dissection (LND) has not shown survival benefits in some tumors. Hence, the decision to remove TDLNs in oncological treatment needs to be reconsidered. Herein, we spotlight the TDLNs of BC and introduce how BC cells modulate stromal cells and immune cells to shape an immunosuppressive TDLN microenvironment for BC progression. We summarize the existing therapeutic strategies to reinvigorate anti-tumor immunity in TDLNs. Furthermore, we discuss whether to preserve TDLNs and the role of LND during oncological treatment.

Tertiary lymphoid structures in the central nervous system

Tertiary lymphoid structures (TLSs) frequently occur at sites of chronic inflammation. A more advanced stage of multiple sclerosis (MS) has been associated with certain TLSs. However, tumor-associated TLSs have been shown to correlate with a greater treatment response rate and a better prognosis in glioma mouse models. In this review, we evaluate the clinical significances of TLSs in prognosis and treatment response, as well as the status of TLS-directed therapies targeting alternative biochemical pathways in various central nervous system (CNS) disorders. Potential molecular mechanisms underlying the development of TLSs are also discussed. Exploring these areas may provide an essential understanding of the processes behind disease advancement, uncover new therapeutic objectives, and detect biomarkers that forecast disease progression and treatment efficacy.

Current status and advances to improving drug delivery in diffuse intrinsic pontine glioma

Diffuse midline glioma (DMG), including tumors diagnosed in the brainstem (diffuse intrinsic pontine glioma - DIPG), is the primary cause of brain tumor-related death in pediatric patients. DIPG is characterized by a median survival of <12 months from diagnosis, harboring the worst 5-year survival rate of any cancer. Corticosteroids and radiation are the mainstay of therapy; however, they only provide transient relief from the devastating neurological symptoms. Numerous therapies have been investigated for DIPG, but the majority have been unsuccessful in demonstrating a survival benefit beyond radiation alone. Although many barriers hinder brain drug delivery in DIPG, one of the most significant challenges is the blood-brain barrier (BBB). Therapeutic compounds must possess specific properties to enable efficient passage across the BBB. In brain cancer, the BBB is referred to as the blood-brain tumor barrier (BBTB), where tumors disrupt the structure and function of the BBB, which may provide opportunities for drug delivery. However, the biological characteristics of the brainstem's BBB/BBTB, both under normal physiological conditions and in response to DIPG, are poorly understood, which further complicates treatment. Better characterization of the changes that occur in the BBB/BBTB of DIPG patients is essential, as this informs future treatment strategies. Many novel drug delivery technologies have been investigated to bypass or disrupt the BBB/BBTB, including convection enhanced delivery, focused ultrasound, nanoparticle-mediated delivery, and intranasal delivery, all of which are yet to be clinically established for the treatment of DIPG. Herein, we review what is known about the BBB/BBTB and discuss the current status, limitations, and advances of conventional and novel treatments to improving brain drug delivery in DIPG.

New progress in the treatment of diffuse midline glioma with H3K27M alteration

Diffuse midline glioma with H3K27 M alteration is a primary malignant tumor located along the linear structure of the brain, predominantly manifesting in children and adolescents. The mortality rate is exceptionally high, with a mere 1 % 5-year survival rate for newly diagnosed patients. Beyond conventional surgery, radiotherapy, and chemotherapy, novel approaches are imperative to enhance patient prognosis. This article comprehensively reviews current innovative treatment modalities and provides updates on the latest research advancements in preclinical studies and clinical trials focusing on H3K27M-altered diffuse midline glioma. The goal is to contribute positively to clinical treatment strategies.

Immunogenic Cell Death Enhances Immunotherapy of Diffuse Intrinsic Pontine Glioma: From Preclinical to Clinical Studies

Diffuse intrinsic pontine glioma (DIPG) is the most lethal tumor involving the pediatric central nervous system. The median survival of children that are diagnosed with DIPG is only 9 to 11 months. More than 200 clinical trials have failed to increase the survival outcomes using conventional cytotoxic or myeloablative chemotherapy. Immunotherapy presents exciting therapeutic opportunities against DIPG that is characterized by unique and heterogeneous features. However, the non-inflammatory DIPG microenvironment greatly limits the role of immunotherapy in DIPG. Encouragingly, the induction of immunogenic cell death, accompanied by the release of damage-associated molecular patterns (DAMPs) shows satisfactory efficacy of immune stimulation and antitumor strategies. This review dwells on the dilemma and advances in immunotherapy for DIPG, and the potential efficacy of immunogenic cell death (ICD) in the immunotherapy of DIPG.

INSC Is Down-Regulated in Colon Cancer and Correlated to Immune Infiltration

Background: Previous studies have verified that Inscuteable Spindle Orientation Adaptor Protein (INSC) can regulate cell proliferation and differentiation in the developing nervous system. It also plays an important role in spindle orientation during mitosis and asymmetric division of fibroblasts and participates in the process of stratification of the squamous epithelium. The role and potential mechanism of INSC in the development of colonic adenocarcinoma (COAD) have not been fully understood. This study aimed at exploring the prognostic value of INSC in COAD and the correlation of its expression with immune infiltration.

Methods: The Cancer Genome Atlas (TCGA), Genotype-Tissue Expression (GTEx) project, Gene Expression Profiling Interactive Analysis (GEPIA), and Gene Expression Omnibus (GEO) database were used to analyze the expression of INSC in COAD. The INSC protein expression level was analyzed by immunohistochemistry staining and the Human Protein Atlas (HPA) database. The diagnostic and prognostic values of INSC in COAD patients were analyzed using receiver operating characteristic (ROC) and Kaplan–Meier (KM) survival curves. In order to understand whether INSC is an independent prognostic factor, we used univariable and multivariate Cox analyses to analyze INSC expression and several clinical characteristics with survival. We use STRING analysis to find INSC-related proteins and related biological events analyzed by Gene Ontology (GO) annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. At last, GEPIA and the Tumor Immune Estimation Resource (TIMER) were employed to explore the relationship between INSC and immune infiltrates and its marker gene set.

Results: INSC was lower expressed in COAD tissues than in normal colon tissues, which was correlated with tumor stage. Patients with lower expression of INSC had shorter overall survival (OS). Moreover, univariable Cox analysis demonstrated that high expression of INSC was an independent prognostic factor for COAD. ROC analysis showed INSC was an accurate marker for identifying tumors from normal colon tissue, and the AUC of the curve was 0.923. Significant GO term analysis by GSEA showed that genes correlated with INSC were found to be enriched in several immune-related pathways. Specifically, INSC expression showed significant negative correlations with infiltration levels of B cells, CD4+ T cells, macrophages, DCs, and their marker sets in COAD.

Conclusion: INSC was provided with prognostic value in COAD and related to immune invasion.

Oncolytic adenovirus-mediated intratumoral expression of TRAIL and CD40L enhances immunotherapy by modulating the tumor microenvironment in immunocompetent mouse models

The immune status of the tumor microenvironment is a key indicator determining the antitumor effect of immunotherapy. Oncolytic viruses directly target tumor cells or indirectly modulate the tumor microenvironment (TME) especially when properly armed. It was previously demonstrated that conditionally replicating adenovirus serotype 5 (CRAd5) encoding tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) had outstanding antitumor effects in different human cancer cells xenograft models; however, its antitumor immune mechanism has not been evaluated in immunocompetent preclinical mouse models. We first explored the antitumor activity of CRAd5-TRAIL in several murine tumor models and found that the expression of TRAIL induced increases or activation in tumor-infiltrating T cells. To further improve the antitumor effects, mouse CD40 ligand (mCD40L) as an immune activator expressed by recombinant Ad5 vector was firstly used in combination with CRAd5-TRAIL for tumor immunotherapy. Both in vitro and in vivo studies demonstrated that mCD40L effectively activated dendritic cells (DCs), B cells, and tumor-infiltrating T cells, and also promoted tumor cell apoptosis by increasing the expression of TRAIL receptors, thereby significantly enhancing the antitumor activity of oncolytic adenoviruses in CT26 and B16 tumor-bearing models. Although affected by the restriction of oncolytic adenovirus replication in mouse cells, the combination treatment failed to completely eliminate tumor cells, our research still provided a promising strategy for oncolytic adenovirus-mediated solid tumor immunotherapy.

Modulating Oncolytic Adenovirus Immunotherapy by Driving Two Axes of the Immune System by Expressing 4-1BBL and CD40L

Oncolytic viruses (OVs) can have utility for direct killing of cancer cells, but may also serve to activate the immune system against cancer cells. While viruses alone can serve as immune stimulators, there is great interest in arming OVs with genes encoding immune stimulatory proteins to amplify their effects. In this work, we have tested the efficacy of conditionally-replicating adenoviruses (CRAds) with and without selected immunostimulatory payloads, murine CD40L (mCD40L) or 4-1BBL (m4-1BBL), in an immune competent mouse model of melanoma. When CRAd657-m4-1BBL and CRAd657-mCD40L were injected into B16-hCAR murine melanoma tumors, both single vectors delayed tumor growth and prolong survival compared to empty CRAd657. However, combined injection of both CRAd-m4-1BBL and CRAd-mCD40L mediated significantly better control of tumor growth. All of the payloads increased immune cell infiltration into tumors and notably reduced expression of PD-1 exhaustion marker on T cells. Tumor volumes were negatively associated with total infiltrating T cell population. We found that the payloads increased immune cell infiltration into tumors with some specificities: recruitment of CD8+ T cells was higher with m4-1BBL expression, while mCD40L expression induced more CD4+ T cell infiltration. Importantly, the combination of CRAd657-m4-1BBL and CRAd657-mCD40L induced the highest immune cells/T cell infiltration and the highest anti-TRP-2 tumor-associated antigen T cell responses than empty or single gene vector. This combination also caused depigmentation in areas adjacent to the tumor sites in more animals. These data indicate that driving two axes of the immune system with combined immune stimulatory payloads can lead to improved anticancer immune responses and better tumor control in an immune competent model of cancer.

Glioma Immunotherapy: Advances and Challenges for Spinal Cord Gliomas

Spinal cord gliomas are rare entities that often have limited surgical options. Immunotherapy has shown promise in intracranial gliomas with some research suggesting benefit for spinal cord gliomas. A focused review of immunotherapies that have been investigated in spinal cord gliomas was performed. The primary methods of immunotherapy investigated in spinal cord gliomas include immune checkpoint inhibitors, adoptive T-cell therapies, and vaccine strategies. There are innumerable challenges that must be overcome to effectively apply immunotherapeutic strategies to the spinal cord gliomas including low incidence, few antigenic targets, the blood spinal cord barrier, the immunosuppressive tumor microenvironment and neurotoxic treatment effects. Nonetheless, research has suggested ways to overcome these challenges and treatments have been effective in case reports for metastatic non-small cell lung cancer, melanoma, midline glioma and glioblastoma. Current therapies for spinal cord gliomas are markedly limited. Further research is needed to determine if the success of immunotherapy for intracranial gliomas can be effectively applied to these unique tumors.

Tertiary Lymphoid Structures in the Central Nervous System: Implications for Glioblastoma

Glioblastoma is the most common and aggressive brain tumor, which is uniformly lethal due to its extreme invasiveness and the absence of curative therapies. Immune checkpoint inhibitors have not yet proven efficacious for glioblastoma patients, due in part to the low prevalence of tumor-reactive T cells within the tumor microenvironment. The priming of tumor antigen-directed T cells in the cervical lymph nodes is complicated by the shortage of dendritic cells and lack of appropriate lymphatic vessels within the brain parenchyma. However, recent data suggest that naive T cells may also be primed within brain tumor-associated tertiary lymphoid structures. Here, we review the current understanding of the formation of these structures within the central nervous system, and hypothesize that promotion of tertiary lymphoid structures could enhance priming of tumor antigen-targeted T cells and sensitize glioblastomas to cancer immunotherapy.