Immunomodulation of Tumor Vessels: It Takes Two to Tango

Targeting Tumor Endothelial Cells by EGCG Using Specific Liposome Delivery System Inhibits Vascular Inflammation and Thrombosis

BACKGROUND

Inflammation is one of the hallmarks of cancer and is associated with tumor growth. Tumor endothelial cells (TECs) demonstrate inflamed phenotypes. Endothelial inflammation initiates thrombus formation, which is the second cause of cancer-related deaths. Epigallocatechin-3-O-gallate (EGCG), a natural compound in green tea, has demonstrated an anti-inflammatory effect. However, the tumor progression inhibition effect of EGCG by targeting TEC inflammation remains unclear. This study addresses the anti-tumor effect of EGCG, especially its anti-inflammatory role in TECs.

METHODS

In vitro, the effect of EGCG on TECs were studied using real-time quantitative PCR and immunofluoresence to analyza gene and protein expression. In vivo, a cyclic RGD liposome delivery system (MEND) was employed to efficiently deliver EGCG to TECs in tumor-bearing mice.

RESULTS

In vitro, EGCG significantly reduces inflammatory cytokine expression, including tumor necrosis factor-α, interleukin-6, IL-8, and IL-1β through NF-κB signaling inhibition. Additionally, von Willebrand factor reduction in TECs, which is involved in platelet adhesion and thrombosis formation, was analyzed. Our results revealed that EGCG-MEND significantly inhibited TEC inflammation and thrombus formation in tumors. Additionally, EGCG-MEND improved tumor immunity by reducing programmed death-ligand 1 expression and promoting high endothelial venule formation by recruiting CD8+ T cells.

CONCLUSION

Our results indicate the anti-tumor potential of EGCG-MEND in normalizing the inflammatory immune microenvironment and inhibiting thrombosis by targeting TEC.

Dual-Functional Nanodroplet for Tumor Vasculature Ultrasound Imaging and Tumor Immunosuppressive Microenvironment Remodeling

Accurately evaluating tumor neoangiogenesis and conducting precise interventions toward an immune-favorable microenvironment are of significant clinical importance. In this study, a novel nanodroplet termed as the nanodroplet-based ultrasound contrast agent and therapeutic (NDsUCA/Tx) is designed for ultrasound imaging and precise interventions of tumor neoangiogenesis. Briefly, the NDsUCA/Tx shell is constructed from an engineered CMs containing the tumor antigen, vascular endothelial growth factor receptor 1 (VEGFR1) extracellular domain 2-3, and CD93 ligand multimerin 2. The core is composed of perfluorohexane and the immune adjuvant R848. After injection, NDsUCA/Tx is found to be enriched in the tumor vasculature with high expression of CD93. When triggered by ultrasound, the perfluorohexane in NDsUCA/Tx underwent acoustic droplet vaporization and generated an enhanced ultrasound signal. Some microbubbles exploded and the resultant debris (with tumor antigen and R848) together with the adsorbed VEGF are taken up by nearby cells. This cleared the local VEGF for vascular normalization, and also served as a vaccine to activate the immune response. Using a syngeneic mouse model, the satisfactory performance of NDsUCA/Tx in tumor vasculature imaging and immune activation is confirmed. Thus, a multifunctional NDsUCA/Tx is successfully developed for molecular imaging of tumor neoangiogenesis and precise remodeling of the tumor microenvironment.

A Wurster-Type Covalent Organic Framework with Internal Electron Transfer-Enhanced Catalytic Capacity for Tumor Therapy

The low immunogenicity of tumors, along with the abnormal structural and biochemical barriers of tumor-associated vasculature, impedes the infiltration and function of effector T cells at the tumor site, severely inhibiting the efficacy of antitumor immunotherapy. In this study, a cobaloxime catalyst and STING agonist (MSA-2)-coloaded Wurster-type covalent organic framework (Co-TB COF-M) with internal electron transfer-enhanced catalytic capacity was developed as a COF-based immune activator. The covalently anchored cobaloxime adjusts the energy band structure of TB COF and provides it with good substrate adsorption sites, enabling it to act as an electron transmission bridge between the COF and substrate in proton reduction catalytic reactions. This property significantly enhances the sonodynamic catalytic performance. Under sono-irradiation, Co-TB COF-M can produce a substantial amount of reactive oxygen species (ROS) to induce Gasdermin D-mediated pro-inflammatory pyroptosis, thereby effectively enhancing the immunogenicity of tumors. Furthermore, MSA-2 is specifically released in response to ROS at the tumor site, minimizing the off-target side effects. More importantly, Co-TB COF-induced STING activation normalizes tumor vasculature and increases the expression of endothelial T cell adhesion molecules, which greatly enhance the infiltration and function of effector T cells. Thus, Co-TB COF-M as an immune activator could remold the tumor microenvironment, leading to increased infiltration and an improved function of T cells for immunotherapy.

Immune priming and induction of tertiary lymphoid structures in a cord-blood humanized mouse model of gastrointestinal stromal tumor

Gastrointestinal stromal tumors (GISTs) harbor diverse immune cell populations but so far immunotherapy in patients has been disappointing. Here, we established cord blood humanized mouse models of localized and disseminated GIST to explore the remodeling of the tumor environment for improved immunotherapy. Specifically, we assessed the ability of a cancer vascular targeting peptide (VTP) to bind to mouse and patient GIST angiogenic blood vessels and deliver the TNF superfamily member LIGHT (TNFS14) into tumors. LIGHT-VTP treatment of GIST in humanized mice improved vascular function and tumor oxygenation, which correlated with an overall increase in intratumoral human effector T cells. Concomitant with LIGHT-mediated vascular remodeling, we observed intratumoral high endothelial venules (HEVs) and tertiary lymphoid structures (TLS), which resemble spontaneous TLS found in GIST patients. Thus, by overcoming the limitations of immunodeficient xenograft models, we demonstrate the therapeutic feasibility of vascular targeting and immune priming in human GIST. Since TLS positively correlate with patient prognosis and improved response to immune checkpoint inhibition, vascular LIGHT targeting in GIST is a highly translatable approach to improve immunotherapeutic outcomes.

Acetyl-NPKY of integrin-β1 binds KINDLIN2 to control endothelial cell proliferation and junctional integrity

Integrin-dependent crosstalk between cell-matrix adhesions and cell-cell junctions is critical for controlling endothelial permeability and proliferation in cancer and inflammatory diseases but remains poorly understood. Here, we investigated how acetylation of the distal NPKY-motif of Integrin-β1 influences endothelial cell physiology and barrier function. Expression of an acetylation-mimetic β1-K794Q-GFP mutant led to the accumulation of immature cell-matrix adhesions accompanied by a transcriptomic reprograming of endothelial cells, involving genes associated with cell adhesion, proliferation, polarity, and barrier function. β1-K794Q-GFP induced constitutive MAPK signaling, junctional impairment, proliferation, and reduced contact inhibition at confluence. Structural analysis of Integrin-β1 interaction with KINDLIN2, biochemical pulldown assay, and binding energy determination by using molecular dynamics simulation showed that acetylation of K794 and the K794Q-mutant increased KINDLIN2 binding affinity to the Integrin-β1. Thus, enhanced recruitment of KINDLIN2 to Lysine-acetylated Integrin-β1 and resulting modulation of barrier function, offers new therapeutic possibilities for controlling vascular permeability and disease conditions.

Tertiary lymphoid structural heterogeneity determines tumour immunity and prospects for clinical application

Tertiary lymphoid structures (TLS) are clusters of immune cells that resemble and function similarly to secondary lymphoid organs (SLOs). While TLS is generally associated with an anti-tumour immune response in most cancer types, it has also been observed to act as a pro-tumour immune response. The heterogeneity of TLS function is largely determined by the composition of tumour-infiltrating lymphocytes (TILs) and the balance of cell subsets within the tumour-associated TLS (TA-TLS). TA-TLS of varying maturity, density, and location may have opposing effects on tumour immunity. Higher maturity and/or higher density TLS are often associated with favorable clinical outcomes and immunotherapeutic response, mainly due to crosstalk between different proportions of immune cell subpopulations in TA-TLS. Therefore, TLS can be used as a marker to predict the efficacy of immunotherapy in immune checkpoint blockade (ICB). Developing efficient imaging and induction methods to study TA-TLS is crucial for enhancing anti-tumour immunity. The integration of imaging techniques with biological materials, including nanoprobes and hydrogels, alongside artificial intelligence (AI), enables non-invasive in vivo visualization of TLS. In this review, we explore the dynamic interactions among T and B cell subpopulations of varying phenotypes that contribute to the structural and functional diversity of TLS, examining both existing and emerging techniques for TLS imaging and induction, focusing on cancer immunotherapies and biomaterials. We also highlight novel therapeutic approaches of TLS that are being explored with the aim of increasing ICB treatment efficacy and predicting prognosis.

Disturbed endothelial cell signaling in tumor progression and therapy resistance

Growth of new blood vessels is considered requisite to cancer progression. Recent findings revealed that in addition to inducing angiogenesis, tumor-derived factors alter endothelial cell gene transcription within the tumor mass but also systemically throughout the body. This subsequently contributes to immunosuppression, altered metabolism, therapy resistance and metastasis. Clinical studies demonstrated that targeting the endothelium can increase the success rate of immunotherapy. Single-cell technologies revealed remarkable organ-specific endothelial heterogeneity that becomes altered by the presence of a tumor. In metastases, endothelial transcription differs remarkably between newly formed and co-opted vessels which may provide a basis for developing new therapies to target endothelial cells and overcome therapy resistance more effectively. This review addresses how cancers impact the endothelium to facilitate tumor progression.

Dynamic polarization of tumor-associated macrophages and their interaction with intratumoral T cells in an inflamed tumor microenvironment: from mechanistic insights to therapeutic opportunities

Immunotherapy has brought a paradigm shift in the treatment of tumors in recent decades. However, a significant proportion of patients remain unresponsive, largely due to the immunosuppressive tumor microenvironment (TME). Tumor-associated macrophages (TAMs) play crucial roles in shaping the TME by exhibiting dual identities as both mediators and responders of inflammation. TAMs closely interact with intratumoral T cells, regulating their infiltration, activation, expansion, effector function, and exhaustion through multiple secretory and surface factors. Nevertheless, the heterogeneous and plastic nature of TAMs renders the targeting of any of these factors alone inadequate and poses significant challenges for mechanistic studies and clinical translation of corresponding therapies. In this review, we present a comprehensive summary of the mechanisms by which TAMs dynamically polarize to influence intratumoral T cells, with a focus on their interaction with other TME cells and metabolic competition. For each mechanism, we also discuss relevant therapeutic opportunities, including non-specific and targeted approaches in combination with checkpoint inhibitors and cellular therapies. Our ultimate goal is to develop macrophage-centered therapies that can fine-tune tumor inflammation and empower immunotherapy.

STING-activating nanoparticles normalize the vascular-immune interface to potentiate cancer immunotherapy

The tumor-associated vasculature imposes major structural and biochemical barriers to the infiltration of effector T cells and effective tumor control. Correlations between stimulator of interferon genes (STING) pathway activation and spontaneous T cell infiltration in human cancers led us to evaluate the effect of STING-activating nanoparticles (STANs), which are a polymersome-based platform for the delivery of a cyclic dinucleotide STING agonist, on the tumor vasculature and attendant effects on T cell infiltration and antitumor function. In multiple mouse tumor models, intravenous administration of STANs promoted vascular normalization, evidenced by improved vascular integrity, reduced tumor hypoxia, and increased endothelial cell expression of T cell adhesion molecules. STAN-mediated vascular reprogramming enhanced the infiltration, proliferation, and function of antitumor T cells and potentiated the response to immune checkpoint inhibitors and adoptive T cell therapy. We present STANs as a multimodal platform that activates and normalizes the tumor microenvironment to enhance T cell infiltration and function and augments responses to immunotherapy.

Vascular Normalization Was Associated with Colorectal Tumor Regression upon Anti-PD-L1 Combinational Therapy

Anti-PD-L1 therapy exhibits durable efficacy, but only in a small fraction of cancer patients. The immunosuppressive tumor microenvironment (TME) is a crucial obstacle that impedes cancer immunotherapy. Here, we found that anti-PD-L1 therapy coupled with CD4+ T cell depletion induced colorectal tumor regression and vascular normalization, while monotherapy only retarded tumor growth without affecting the tumor vasculature. Moreover, simultaneous PD-L1 blockade and CD4+ T cell depletion eradicated intratumoral PD-L1+ lymphoid and myeloid cell populations, while additively elevating the proportions of CD44+CD69+CD8+, central memory CD44+CD62L+CD8+, and effector memory CD44+CD62L-CD8+ T cells, suggesting a reduction in immunosuppressive cell populations and the activation of CD8+ T cells in the TME. Moreover, anti-PD-L1 therapy reduced the proportions of intratumoral PD-L1+ immune cells and suppressed tumor growth in a CD8+ T cell dependent manner. Together, these results suggest that anti-PD-L1 therapy induces tumor vascular normalization and colorectal tumor regression via CD8+ T cells, which is antagonized by CD4+ T cells. Our findings unveil the positive correlation of tumor regression and vascular normalization in colorectal tumor models upon anti-PD-L1 therapy, providing a potential new strategy to improve its efficacy.

Emerging immunomodulatory strategies for cell therapeutics

Cellular therapies are poised to transform the field of medicine by restoring dysfunctional tissues and treating various diseases in a dynamic manner not achievable by conventional pharmaceutics. Spanning various therapeutic areas inclusive of cancer, regenerative medicine, and immune disorders, cellular therapies comprise stem or non-stem cells derived from various sources. Despite numerous clinical approvals or trials underway, the host immune response presents a critical impediment to the widespread adoption and success of cellular therapies. Here, we review current research and clinical advances in immunomodulatory strategies to mitigate immune rejection or promote immune tolerance to cellular therapies. We discuss the potential of these immunomodulatory interventions to accelerate translation or maximize the prospects of improving therapeutic outcomes of cellular therapies for clinical success.

Manipulation of the crosstalk between tumor angiogenesis and immunosuppression in the tumor microenvironment: Insight into the combination therapy of anti-angiogenesis and immune checkpoint blockade

Immunotherapy has been recognized as an effective and important therapeutic modality for multiple types of cancer. Nevertheless, it has been increasing recognized that clinical benefits of immunotherapy are less than expected as evidenced by the fact that only a small population of cancer patients respond favorably to immunotherapy. The structurally and functionally abnormal tumor vasculature is a hallmark of most solid tumors and contributes to an immunosuppressive microenvironment, which poses a major challenge to immunotherapy. In turn, multiple immune cell subsets have profound consequences on promoting neovascularization. Vascular normalization, a promising anti-angiogenic strategy, can enhance vascular perfusion and promote the infiltration of immune effector cells into tumors via correcting aberrant tumor blood vessels, resulting in the potentiation of immunotherapy. More interestingly, immunotherapies are prone to boost the efficacy of various anti-angiogenic therapies and/or promote the morphological and functional alterations in tumor vasculature. Therefore, immune reprograming and vascular normalization appear to be reciprocally regulated. In this review, we mainly summarize how tumor vasculature propels an immunosuppressive phenotype and how innate and adaptive immune cells modulate angiogenesis during tumor progression. We further highlight recent advances of anti-angiogenic immunotherapies in preclinical and clinical settings to solidify the concept that targeting both tumor blood vessels and immune suppressive cells provides an efficacious approach for the treatment of cancer.

Vessel state and immune infiltration of the angiogenesis subgroup and construction of a prediction model in osteosarcoma

Angiogenesis has been recognized as a pivotal contributor to tumorigenesis and progression. However, the role of angiogenesis-related genes (ARGs) in vessel state, immune infiltration, and prognosis remains unknown in osteosarcoma (OS). Bulk RNA sequencing data of osteosarcoma patients were obtained from the Therapeutically Applicable Research to Generate Effective Treatments (TARGET) database, and patients were divided into two angiogenesis subgroups according to the expression of ARGs. We compared their vessel state and used two independent algorithms to evaluate the tumor microenvironment (TME) in the two subgroups. Furthermore, hub genes of differentially expressed genes (DEGs) in the two subgroups were selected to perform LASSO regression and multivariate Cox stepwise regression, and two prognostic hub genes were found. An ARG_score based on prognostic hub genes was calculated and proved to be reliable in the overall survival prediction in OS patients. Furthermore, the ARG_score was significantly associated with ARGs, immune infiltration, response to immunotherapy, and drug sensitivity. To make our prediction model perform well, clinical features were added and a highly accurate interactive nomogram was constructed. Immunohistochemistry and qRT-PCR were utilized to verify the expression of prognostic hub genes. GSE21257 from the Gene Expression Omnibus (GEO) database was used as a validation dataset to verify its robustness. In conclusion, our comprehensive analysis of angiogenesis subgroups in OS illustrated that angiogenesis may lead to different vessel states and further affect immune infiltration and prognosis of OS patients. Our findings may bring a novel perspective for the immunotherapy strategies for OS patients.

Single-intraosseous simvastatin injection suppresses cancers via activating CD8+ T cells

Immunotherapies provide effective strategies for cancer treatment. Cholesterol induces CD8⁺ T cell exhaustion, which inhibits antitumor immunity. CD8⁺ T cells are derived from bone marrow and transport and function in bone marrow, where provides more porous cavities for drugs to access the circulation than other solid organs. We previously found that single-dose intraosseous (i.o.) injection of simvastatin suppresses breast cancer development and prolongs survival, but the exact mechanism remains unclear. In this study, we found the antitumor activity of simvastatin i.o. mainly depended on CD8⁺ T cells. Simvastatin i.o. increased the percentage and cytotoxicity of CD8⁺ T cells and downregulated the expression of PD-1, TIM3 and CTLA4 in CD8⁺ T cells in vivo. Simvastatin promoted the activation, proliferation and cytotoxicity of tumor antigen-specific CD8⁺ T cells in vitro. Furthermore, Simvastatin i.o. suppressed cancers by activating the T-cell antigen receptor signaling pathway. Taken together, simvastatin i.o. effectively suppresses cancer progression, which would be a potential strategy for cancer treatment.

Acquired αSMA Expression in Pericytes Coincides with Aberrant Vascular Structure and Function in Pancreatic Ductal Adenocarcinoma

The subpopulations of tumor pericytes undergo pathological phenotype switching, affecting their normal function in upholding structural stability and cross-communication with other cells. In the case of pancreatic ductal adenocarcinoma (PDAC), a significant portion of blood vessels are covered by an α-smooth muscle actin (αSMA)-expressing pericyte, which is normally absent from capillary pericytes. The Desmin^lowαSMA^high phenotype was significantly correlated with intratumoral hypoxia and vascular leakiness. Using an in vitro co-culture system, we demonstrated that cancer cell-derived exosomes could induce ectopic αSMA expression in pericytes. Exosome-treated αSMA⁺ pericytes presented altered pericyte markers and an acquired immune-modulatory feature. αSMA⁺ pericytes were also linked to morphological and biomechanical changes in the pericyte. The PDAC exosome was sufficient to induce αSMA expression by normal pericytes of the healthy pancreas in vivo, and the vessels with αSMA⁺ pericytes were leaky. This study demonstrated that tumor pericyte heterogeneity could be dictated by cancer cells, and a subpopulation of these pericytes confers a pathological feature.

A Novel Angiogenesis-Related Prognostic Signature Associated with the Hepatocellular Carcinoma Immune Microenvironment and Survival Outcome

Purpose

Hepatocellular carcinoma (HCC) is a highly vascularized solid tumor characterized by neovascularization and vascular invasion. Angiogenesis plays an essential role in the occurrence and development of liver cancer. Our study aimed to investigate the prognostic value of angiogenesis-related genes in liver cancer.

Patients and Methods

The transcriptome data and corresponding clinical information of patients with liver cancer were downloaded from The Cancer Genome Atlas (TCGA) and the International Cancer Genome Consortium (ICGC) databases. In the TCGA cohort, differential expression and prognostic analyses were used to screen angiogenesis-related candidate prognostic genes. We then used least absolute shrinkage and selection operator regression analysis to construct a prognostic signature using 10 angiogenesis-related prognostic genes. The reliability of the prognostic signature was assessed in the TCGA and ICGC cohorts. In addition, we comprehensively analyzed the correlation of the prognostic signature with the tumor microenvironment, chemotherapy drugs, and specific genes.

Results

We identified 37 angiogenesis-related differentially expressed genes that were remarkably associated with prognosis. Ten of these genes were used to establish a survival and prognostic signature. This signature can distinguish between high-risk and low-risk groups and performs well in overall survival prediction, as demonstrated by internal and external validations. In addition, we observed that the high-risk group was remarkably associated with immune infiltration in the tumor microenvironment and had a different sensitivity to chemotherapeutic agents compared with the low-risk group. Moreover, the high-risk population was positively correlated with the expression of several special genes, such as immune checkpoint-related genes.

Conclusion

Our results demonstrated that prognostic signatures based on angiogenesis-related genes are involved in the development of HCC and may provide new insights into accurate clinical decision-making and therapeutic evaluation of patients with HCC.

LRG1 destabilizes tumor vessels and restricts immunotherapeutic potency

BACKGROUND

A poorly functioning tumor vasculature is pro-oncogenic and may impede the delivery of therapeutics. Normalizing the vasculature, therefore, may be beneficial. We previously reported that the secreted glycoprotein leucine-rich α-2-glycoprotein 1 (LRG1) contributes to pathogenic neovascularization. Here, we investigate whether LRG1 in tumors is vasculopathic and whether its inhibition has therapeutic utility.

METHODS

Tumor growth and vascular structure were analyzed in subcutaneous and genetically engineered mouse models in wild-type and Lrg1 knockout mice. The effects of LRG1 antibody blockade as monotherapy, or in combination with co-therapies, on vascular function, tumor growth, and infiltrated lymphocytes were investigated.

FINDINGS

In mouse models of cancer, Lrg1 expression was induced in tumor endothelial cells, consistent with an increase in protein expression in human cancers. The expression of LRG1 affected tumor progression as Lrg1 gene deletion, or treatment with a LRG1 function-blocking antibody, inhibited tumor growth and improved survival. Inhibition of LRG1 increased endothelial cell pericyte coverage and improved vascular function, resulting in enhanced efficacy of cisplatin chemotherapy, adoptive T cell therapy, and immune checkpoint inhibition (anti-PD1) therapy. With immunotherapy, LRG1 inhibition led to a significant shift in the tumor microenvironment from being predominantly immune silent to immune active.

CONCLUSIONS

LRG1 drives vascular abnormalization, and its inhibition represents a novel and effective means of improving the efficacy of cancer therapeutics.

FUNDING

Wellcome Trust (206413/B/17/Z), UKRI/MRC (G1000466, MR/N006410/1, MC/PC/14118, and MR/L008742/1), BHF (PG/16/50/32182), Health and Care Research Wales (CA05), CRUK (C42412/A24416 and A17196), ERC (ColonCan 311301 and AngioMature 787181), and DFG (CRC1366).

Comprehensive Analysis of Glutamate-Rich WD Repeat-Containing Protein 1 and Its Potential Clinical Significance for Pancancer

Methods

The expression level of GRWD1 in human cancer tissues was analyzed using the Tumor Immune Evaluation Resource (ver. 2.0, TIMER2), Gene Expression Profiling Interactive Analysis (ver. 2, GEPIA2), and UALCAN databases. The Kaplan-Meier plotter was utilized to analyze the survival data. Spearman's correlation analysis was used to find out the correlation between the expression level of GRWD1 and predictive biomarkers, such as tumor mutation burden (TMB) and microsatellite instability (MSI). Furthermore, the MEXPRESS website was used to study the potential relationship between DNA methylation level of GRWD1 and pathological staging. We utilized the “immune” module provided on the TIMER2 website to explore the relationship between the expression level of GRWD1 and immune infiltration in all types of cancer in TCGA. Pearson's correlation analysis was used to investigate the correlation between the expression level of GRWD1 and the expression levels of immune checkpoint-related genes. For protein expression analysis, we used the CPTAC module provided by the UALCAN portal to compare the total protein and phosphorylated protein level of GRWD1 in adjacent normal and tumor tissues.

Results

GRWD1 was overexpressed in tissues of most types of cancer, in which the expression levels of GRWD1 in the kidney chromophobe (KICH), kidney renal papillary cell carcinoma (KIRP), and kidney renal clear cell carcinoma (KIRC) tissues showed an opposite trend, and the expression level of GRWD1 was correlated to only the KIRC tumor stage. The results of survival analysis showed that the expression level of GRWD1 was significantly associated with overall survival in six types of cancer and disease-free survival (DFS) in three types of cancer. Importantly, the increased expression level of GRWD1 was strongly correlated with prognosis of KIRC patients. There was a positive relationship between the expression level of GRWD1 and immune cell infiltration in several types of cancer, and the expression level of GRWD1 was also positively correlated with TMB, MSI, and DNA methylation in some types of cancer. The results of Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis revealed that “ubiquitin mediated proteolysis,” “spliceosome,” and “nucleotide excision repair” were involved in the effect of GRWD1 expression on tumor pathogenesis.

Conclusion

This pancancer analysis provided a comprehensive overview of the carcinogenic effects of GRWD1 on a variety of human cancers. The results of bioinformatics analysis indicated GRWD1 as a promising biomarker for detection, prognosis, and therapeutic assessment of diverse types of cancer, and GRWD1 could act as a tumor suppressor in KIRC.

Radioimmunotherapy: future prospects from the perspective of brachytherapy

In combination with radiotherapy, immunotherapy is becoming an increasingly used strategy in treating advanced, recurrent, or metastatic cancer. The evident impact of radiotherapy on local and systemic immune response is an indication of the synergistic effect of these two modalities. There is a strong rationale to combine radiotherapy and immunotherapy to enhance response rates and overcome resistances. Therefore, the combination of radio- and immunotherapy holds a variety of opportunities as well as challenges in treating primary cancer and is progressively tested in curative settings. Brachytherapy is also known as internal radiation therapy and only offers a local therapy option at first glance: due to tumor-specific antigens, released by a high local radiation dose, a systemic immune response could be plausible and eminent. Accordingly, brachytherapy could be an underestimated partner with immuno-therapeutic approaches in both curative and palliative settings, to generate local and systemic response. In this review, we summarized the potential benefit of a potential combination of brachytherapy and immuno-therapeutic approaches vs. the background of limited data.

Multi-Parameter Quantitative Imaging of Tumor Microenvironments Reveals Perivascular Immune Niches Associated With Anti-Tumor Immunity

Tumors are populated by a multitude of immune cell types with varied phenotypic and functional properties, which can either promote or inhibit anti-tumor responses. Appropriate localization and function of these cells within tumors is critical for protective immunity, with CD8 T cell infiltration being a biomarker of disease outcome and therapeutic efficacy. Recent multiplexed imaging approaches have revealed highly complex patterns of localization for these immune cell subsets and the generation of distinct tumor microenvironments (TMEs), which can vary among cancer types, individuals, and within individual tumors. While it is recognized that TMEs play a pivotal role in disease progression, a better understanding of their composition, organization, and heterogeneity, as well as how distinct TMEs are reshaped with immunotherapy, is necessary. Here, we performed spatial analysis using multi-parameter confocal imaging, histocytometry, and CytoMAP to study the microanatomical organization of immune cells in two widely used preclinical cancer models, the MC38 colorectal and KPC pancreatic murine tumors engineered to express human carcinoembryonic antigen (CEA). Immune responses were examined in either unperturbed tumors or after immunotherapy with a CEA T cell bispecific (CEA-TCB) surrogate antibody and anti-PD-L1 treatment. CEA-TCB mono and combination immunotherapy markedly enhanced intra-tumoral cellularity of CD8 T cells, dominantly driven by the expansion of TCF1-PD1+ effector T cells and with more minor increases in TCF1+PD1+ resource CD8 T cells. The majority of infiltrating T cells, particularly resource CD8 T cells, were colocalized with dendritic cells (DCs) or activated MHCII+ macrophages, but largely avoided the deeper tumor nest regions composed of cancer cells and non-activated macrophages. These myeloid cell - T cell aggregates were found in close proximity to tumor blood vessels, generating perivascular immune niches. This perivascular TME was present in untreated samples and markedly increased after CEA-TCB therapy, with its relative abundance positively associated with response to therapy. Together, these studies demonstrate the utility of advanced spatial analysis in cancer research by revealing that blood vessels are key organizational hubs of innate and adaptive immune cells within tumors, and suggesting the likely relevance of the perivascular immune TME in disease outcome.

Vascular normalisation as the stepping stone into tumour microenvironment transformation

A functional vascular system is indispensable for drug delivery and fundamental for responsiveness of the tumour microenvironment to such medication. At the same time, the progression of a tumour is defined by the interactions of the cancer cells with their surrounding environment, including neovessels, and the vascular network continues to be the major route for the dissemination of tumour cells in cancer, facilitating metastasis. So how can this apparent conflict be reconciled? Vessel normalisation-in which redundant structures are pruned and the abnormal vasculature is stabilised and remodelled-is generally considered to be beneficial in the course of anti-cancer treatments. A causality between normalised vasculature and improved response to medication and treatment is observed. For this reason, it is important to discern the consequence of vessel normalisation on the tumour microenvironment and to modulate the vasculature advantageously. This article will highlight the challenges of controlled neovascular remodelling and outline how vascular normalisation can shape disease management.

Tertiary Lymphoid Structures in Cancer: The Double-Edged Sword Role in Antitumor Immunity and Potential Therapeutic Induction Strategies

The complex tumor microenvironment (TME) plays a vital role in cancer development and dramatically determines the efficacy of immunotherapy. Tertiary lymphoid structures (TLSs) within the TME are well recognized and consist of T cell-rich areas containing dendritic cells (DCs) and B cell-rich areas containing germinal centers (GCs). Accumulating research has indicated that there is a close association between tumor-associated TLSs and favorable clinical outcomes in most types of cancers, though a minority of studies have reported an association between TLSs and a poor prognosis. Overall, the double-edged sword role of TLSs in the TME and potential mechanisms need to be further investigated, which will provide novel therapeutic perspectives for antitumor immunoregulation. In this review, we focus on discussing the main functions of TLSs in the TME and recent advances in the therapeutic manipulation of TLSs through multiple strategies to enhance local antitumor immunity.

Therapeutic Induction of Tertiary Lymphoid Structures in Cancer Through Stromal Remodeling

Improving the effectiveness of anti-cancer immunotherapy remains a major clinical challenge. Cytotoxic T cell infiltration is crucial for immune-mediated tumor rejection, however, the suppressive tumor microenvironment impedes their recruitment, activation, maturation and function. Nevertheless, solid tumors can harbor specialized lymph node vasculature and immune cell clusters that are organized into tertiary lymphoid structures (TLS). These TLS support naïve T cell infiltration and intratumoral priming. In many human cancers, their presence is a positive prognostic factor, and importantly, predictive for responsiveness to immune checkpoint blockade. Thus, therapeutic induction of TLS is an attractive concept to boost anti-cancer immunotherapy. However, our understanding of how cancer-associated TLS could be initiated is rudimentary. Exciting new reagents which induce TLS in preclinical cancer models provide mechanistic insights into the exquisite stromal orchestration of TLS formation, a process often associated with a more functional or "normalized" tumor vasculature and fueled by LIGHT/LTα/LTβ, TNFα and CC/CXC chemokine signaling. These emerging insights provide innovative opportunities to induce and shape TLS in the tumor microenvironment to improve immunotherapies.

DLL1 orchestrates CD8+ T cells to induce long-term vascular normalization and tumor regression

The immunosuppressive and hypoxic tumor microenvironment (TME) remains a major obstacle to impede cancer immunotherapy. Here, we showed that elevated levels of Delta-like 1 (DLL1) in the breast and lung TME induced long-term tumor vascular normalization to alleviate tumor hypoxia and promoted the accumulation of interferon γ (IFN-γ)-expressing CD8⁺ T cells and the polarization of M1-like macrophages. Moreover, increased DLL1 levels in the TME sensitized anti-cytotoxic T lymphocyte-associated protein 4 (anti-CTLA4) treatment in its resistant tumors, resulting in tumor regression and prolonged survival. Mechanically, in vivo depletion of CD8⁺ T cells or host IFN-γ deficiency reversed tumor growth inhibition and abrogated DLL1-induced tumor vascular normalization without affecting DLL1-mediated macrophage polarization. Together, these results demonstrate that elevated DLL1 levels in the TME promote durable tumor vascular normalization in a CD8⁺ T cell- and IFN-γ-dependent manner and potentiate anti-CTLA4 therapy. Our findings unveil DLL1 as a potential target to persistently normalize the TME to facilitate cancer immunotherapy.

Modulation of the Vascular-Immune Environment in Metastatic Cancer

Advanced metastatic cancer is rarely curable. While immunotherapy has changed the oncological landscape profoundly, cure in metastatic disease remains the exception. Tumor blood vessels are crucial regulators of tumor perfusion, immune cell influx and metastatic dissemination. Indeed, vascular hyperpermeability is a key feature of primary tumors, the pre-metastatic niche in host tissue and overt metastases at secondary sites. Combining anti-angiogenesis and immune therapies may therefore unlock synergistic effects by inducing a stabilized vascular network permissive for effector T cell trafficking and function. However, anti-angiogenesis therapies, as currently applied, are hampered by intrinsic or adaptive resistance mechanisms at primary and distant tumor sites. In particular, heterogeneous vascular and immune environments which can arise in metastatic lesions of the same individual pose significant challenges for currently approved drugs. Thus, more consideration needs to be given to tailoring new combinations of vascular and immunotherapies, including dosage and timing regimens to specific disease microenvironments.

Dendritic cell vaccine therapy for colorectal cancer

Colorectal cancer (CRC) remains a leading cause of cancer-related deaths in the United States despite an array of available treatment options. Current standard-of-care interventions for this malignancy include surgical resection, chemotherapy, and targeted therapies depending on the disease stage. Specifically, infusion of anti-vascular endothelial growth factor agents in combination with chemotherapy was an important development in improving the survival of patients with advanced colorectal cancer, while also helping give rise to other forms of anti-angiogenic therapies. Yet, one approach by which tumor angiogenesis may be further disrupted is through the administration of a dendritic cell (DC) vaccine targeting tumor-derived blood vessels, leading to cytotoxic immune responses that decrease tumor growth and synergize with other systemic therapies. Early generations of such vaccines exhibited protection against various forms of cancer in pre-clinical models, but clinical results have historically been disappointing. Sipuleucel-T (Provenge®) was the first, and to-date, only dendritic cell-based therapy to receive FDA approval after significantly increasing overall survival in prostate cancer patients. The unparalleled success of Sipuleucel-T has helped revitalize the clinical development of dendritic cell vaccines, which will be examined in this review. We also highlight the promise of these vaccines to instill anti-angiogenic immunity for individuals with advanced colorectal cancer.

Identification and validation of methylated differentially expressed miRNAs and immune infiltrate profile in EBV-associated gastric cancer

BACKGROUND

The recent discovery of cancer/tissue specificity of miRNA has indicated its great potential as a therapeutic target. In Epstein-Barr virus-associated gastric cancer (EBVaGC), host genes are affected by extensive DNA methylation, including miRNAs. However, the role of methylated miRNA in the development of EBVaGC and immune cell infiltration has largely remained elusive.

RESULTS

After crossmatching the DNA methylation and expression profile of miRNA and mRNA in the Gene Expression Omnibus (GEO) and the Cancer Genome Atlas Research Network (TCGA), we discovered that miR-129-2-3p was significantly suppressed due to hypermethylation on its enhancer in EBVaGC. The differentially expressed genes (DEGs) added up to 30, among which AKAP12 and LARP6 were predicted to be the target genes of miR-129-2-3p and negatively correlated with patients' survival. Accordingly, miR-129-2-3p was significantly down-regulated in tumor samples in 26 (65%) out of 40 cases in our cohort (P < 0.0001). The proliferation, migration and invasion functions of GC cells were significantly promoted when transfected with miR-129-2-3p inhibitor and suppressed when transfected with mimics or treated with 5-aza-2'-deoxycytidine. Moreover, a comprehensive regulation network was established by combining the putative transcription factors, miRNA-mRNA and protein-protein interaction (PPI) analysis. Pathway enrichment analysis showed that cytokine activity, especially CCL20, was the most prominent biological process in EBVaGC development. Immune cell infiltration analysis demonstrated CD4+ T cell, macrophage and dendritic cell infiltrates were significantly enriched for the prognostic-indicated hub genes.

CONCLUSION

This study has provided a comprehensive analysis of differentially expressed miRNAs and mRNAs associated with genome-wide DNA methylation by integrating multi-source data including transcriptome, methylome and clinical data from GEO and TCGA, QPCR of tumor samples and cell function assays. It also gives a hint on the relationships between methylated miRNA, DEGs and the immune infiltration. Further experimental and clinical investigations are warranted to explore the underlying mechanism and validate our findings.

Thymus involution sets the clock of the aging T-cell landscape: Implications for declined immunity and tissue repair

Aging is generally characterized as a gradual increase in tissue damage, which is associated with senescence and chronic systemic inflammation and is evident in a variety of age-related diseases. The extent to which such tissue damage is a result of a gradual decline in immune regulation, which consequently compromises the capacity of the body to repair damages, has not been fully explored. Whereas CD4 T lymphocytes play a critical role in the orchestration of immunity, thymus involution initiates gradual changes in the CD4 T-cell landscape, which may significantly compromise tissue repair. In this review, we describe the lifespan accumulation of specific dysregulated CD4 T-cell subsets and their coevolution with systemic inflammation in the process of declined immunity and tissue repair capacity with age. Then, we discuss the process of thymus involution-which appears to be most pronounced around puberty-as a possible driver of the aging T-cell landscape. Finally, we identify individualized T cell-based early diagnostic biomarkers and therapeutic strategies for age-related diseases.

Targeting tumor-associated macrophages as an antitumor strategy

Tumor-associated macrophages (TAMs) are the most widely infiltrating immune cells in the tumor microenvironment (TME). Clinically, the number of TAMs is closely correlated with poor outcomes in multiple cancers. The biological actions of TAMs are complex and diverse, including mediating angiogenesis, promoting tumor invasion and metastasis, and building an immunosuppressive microenvironment. Given these pivotal roles of TAMs in tumor development, TAM-based strategies are attractive and used in certain tumor therapies, including inhibition of angiogenic signalling, blockade of the immune checkpoint, and macrophage enhancement phagocytosis. Several attempts to develop TAM-targeted agents have been made to deplete TAMs or reprogram the behaviour of TAMs. Some have shown a favourable curative effect in monotherapy, combination with chemotherapy or immunotherapy in clinical trials. Additionally, a new macrophage-based cell therapeutic technology was recently developed by equipping macrophages with CAR molecules. It is expected to break through barriers to solid tumor treatment. Although TAM-related studies have yielded positive antitumor outcomes, further investigations are needed to better characterize TAMs, which will benefit further establishment of novel strategies for tumor therapy. Here, we concisely summarize the functions of TAMs in the TME and comprehensively introduce the latest TAM-based regimens in cancer treatment.

Manipulation of immune‒vascular crosstalk: new strategies towards cancer treatment

Tumor vasculature is characterized by aberrant structure and function, resulting in immune suppressive profiles of tumor microenvironment through limiting immune cell infiltration into tumors, endogenous immune surveillance and immune cell function. Vascular normalization as a novel therapeutic strategy tends to prune some of the immature blood vessels and fortify the structure and function of the remaining vessels, thus improving immune stimulation and the efficacy of immunotherapy. Interestingly, the presence of "immune‒vascular crosstalk" enables the formation of a positive feedback loop between vascular normalization and immune reprogramming, providing the possibility to develop new cancer therapeutic strategies. The applications of nanomedicine in vascular-targeting therapy in cancer have gained increasing attention due to its specific physical and chemical properties. Here, we reviewed the recent advances of effective routes, especially nanomedicine, for normalizing tumor vasculature. We also summarized the development of enhancing nanoparticle-based anticancer drug delivery via the employment of transcytosis and mimicking immune cell extravasation. This review explores the potential to optimize nanomedicine-based therapeutic strategies as an alternative option for cancer treatment.

B7-H3 augments the pro-angiogenic function of tumor-associated macrophages and acts as a novel adjuvant target for triple-negative breast cancer therapy

B7-H3 is an immune checkpoint molecule from the B7 superfamily. It has been widely studied in tumor immune evasion in certain types of cancer. In our preliminary study, we found that B7-H3 is specifically enriched in tumor-associated macrophages (TAMs) in triple-negative breast cancer (TNBC) patients and strongly correlated with poor clinical prognosis. However, the role of B7-H3 in breast cancer remains elusive. Our current study aims to explore the potential of B7-H3 as a novel target in TNBC therapy. Here, we demonstrated that B7-H3 enriched on TAMs is tightly correlated with TNBC clinical progression. B7-H3^high TAMs exhibit great pro-metastatic and immunosuppressive functions by intriguing extracellular matrix (ECM) reconstruction and tumor angiogenesis, therefore helping tumor cell dissemination and dampening T-cell infiltration in tumor microenvironment (TME). Importantly, targeting blockade of B7-H3 by anti-B7-H3 antibody improves the tumor vasculature disorder, thereby enhancing chemotherapy and PD-1 therapy efficacy. In conclusion, our study establishes the correlation between B7-H3^high TAMs and TNBC progression for the first time. By exploring the possibility of targeting B7-H3 expressed in both tumor cells and TAMs, we suggest that B7-H3 could be a promising target in clinical TNBC treatment.

The VE-Cadherin/β-catenin signalling axis regulates immune cell infiltration into tumours

Vascular normalisation, the process that reverses the structural and functional abnormalities seen in tumour-associated vessels, is also accompanied by changes in leucocyte trafficking. Our previous studies have shown the normalisation effects of the agent CD5-2 which acts to stabilise VE-Cadherin leading to increased penetration of CD8⁺ T cells but decreased infiltration of neutrophils (CD11b⁺Gr1^hi) into tumour parenchyma. In the present study, we demonstrate that VE-Cadherin stabilisation through CD5-2 treatment of purified endothelial cells (ECs) results in a similar leucocyte-selective regulation of transmigration, suggesting the existence of an endothelial specific intrinsic mechanism. Further, we show by RNA sequencing (RNA-seq)-based transcriptomic analysis, that treatment of ECs with CD5-2 regulates chemokines known to be involved in leucocyte transmigration, including upregulation of CCL2 and CXCL10 that facilitate CD8⁺ T cell transmigration. Both in vitro and in vivo mechanistic studies revealed that the increased CCL2 expression was dependent on expression of VE-Cadherin and downstream activation of the AKT/GSK3β/β-catenin/TCF4 signalling pathway. CD5-2 treatment also contributed to the reorganisation of the cytoskeleton, inducing reorganisation of stress fibres to circumferential actin, which previously has been described as associated with the stabilisation of the endothelial barrier, and amplification of the transcellular migration of CD8⁺ T cells. Thus, we propose that promotion of endothelial junctional integrity during vascular normalisation not only inhibits vascular leak but also resets the endothelial dependent regulation of immune cell infiltration.

Lactate Dehydrogenase A Depletion Alters MyC-CaP Tumor Metabolism, Microenvironment, and CAR T Cell Therapy

To enhance human prostate-specific membrane antigen (hPSMA)-specific chimeric antigen receptor (CAR) T cell therapy in a hPSMA+ MyC-CaP tumor model, we studied and imaged the effect of lactate dehydrogenase A (LDH-A) depletion on the tumor microenvironment (TME) and tumor progression. Effective LDH-A short hairpin RNA (shRNA) knockdown (KD) was achieved in MyC-CaP:hPSMA+ Renilla luciferase (RLuc)-internal ribosome entry site (IRES)-GFP tumor cells, and changes in tumor cell metabolism and in the TME were monitored. LDH-A downregulation significantly inhibited cell proliferation and subcutaneous tumor growth compared to control cells and tumors. However, total tumor lactate concentration did not differ significantly between LDH-A knockdown and control tumors, reflecting the lower vascularity, blood flow, and clearance of lactate from LDH-A knockdown tumors. Comparing treatment responses of MyC-CaP tumors with LDH-A depletion and/or anti-hPSMA CAR T cells showed that the dominant effect on tumor growth was LDH-A depletion. With anti-hPSMA CAR T cell treatment, tumor growth was significantly slower when combined with tumor LDH-A depletion and compared to control tumor growth (p < 0.0001). The lack of a complete tumor response in our animal model can be explained in part by (1) the lower activity of human CAR T cells against hPSMA-expressing murine tumors in a murine host, and (2) a loss of hPSMA antigen from the tumor cell surface in progressive generations of tumor cells.

Stem cell programs in cancer initiation, progression, and therapy resistance

Over the past few decades, substantial evidence has convincingly revealed the existence of cancer stem cells (CSCs) as a minor subpopulation in cancers, contributing to an aberrantly high degree of cellular heterogeneity within the tumor. CSCs are functionally defined by their abilities of self-renewal and differentiation, often in response to cues from their microenvironment. Biological phenotypes of CSCs are regulated by the integrated transcriptional, post-transcriptional, metabolic, and epigenetic regulatory networks. CSCs contribute to tumor progression, therapeutic resistance, and disease recurrence through their sustained proliferation, invasion into normal tissue, promotion of angiogenesis, evasion of the immune system, and resistance to conventional anticancer therapies. Therefore, elucidation of the molecular mechanisms that drive cancer stem cell maintenance, plasticity, and therapeutic resistance will enhance our ability to improve the effectiveness of targeted therapies for CSCs. In this review, we highlight the key features and mechanisms that regulate CSC function in tumor initiation, progression, and therapy resistance. We discuss factors for CSC therapeutic resistance, such as quiescence, induction of epithelial-to-mesenchymal transition (EMT), and resistance to DNA damage-induced cell death. We evaluate therapeutic approaches for eliminating therapy-resistant CSC subpopulations, including anticancer drugs that target key CSC signaling pathways and cell surface markers, viral therapies, the awakening of quiescent CSCs, and immunotherapy. We also assess the impact of new technologies, such as single-cell sequencing and CRISPR-Cas9 screening, on the investigation of the biological properties of CSCs. Moreover, challenges remain to be addressed in the coming years, including experimental approaches for investigating CSCs and obstacles in therapeutic targeting of CSCs.

Relevance of immune cell and tumor microenvironment imaging in the new era of immunotherapy

Tumor-infiltrating immune cells play a key role against cancer. However, malignant cells are able to evade the immune response and establish a very complex balance in which different immune subtypes may drive tumor progression, metastatization and resistance to therapy. New immunotherapeutic approaches aim at restoring the natural balance and increase immune response against cancer by different mechanisms. The complexity of these interactions and the heterogeneity of immune cell subpopulations are a real challenge when trying to develop new immunotherapeutics and evaluate or predict their efficacy in vivo. To this purpose, molecular imaging can offer non-invasive diagnostic tools like radiopharmaceuticals, contrast agents or fluorescent dyes. These agents can be useful for preclinical and clinical purposes and can overcome [18F]FDG limitations in discriminating between true-progression and pseudo-progression. This review provides a comprehensive overview of immune cells involved in microenvironment, available immunotherapies and imaging agents to highlight the importance of new therapeutic biomarkers and their in vivo evaluation to improve the management of cancer patients.

TNFSF14: LIGHTing the Way for Effective Cancer Immunotherapy

Tumor necrosis factor superfamily member 14 (LIGHT) has been in pre-clinical development for over a decade and shows promise as a modality of enhancing treatment approaches in the field of cancer immunotherapy. To date, LIGHT has been used to combat cancer in multiple tumor models where it can be combined with other immunotherapy modalities to clear established solid tumors as well as treat metastatic events. When LIGHT molecules are delivered to or expressed within tumors they cause significant changes in the tumor microenvironment that are primarily driven through vascular normalization and generation of tertiary lymphoid structures. These changes can synergize with methods that induce or support anti-tumor immune responses, such as checkpoint inhibitors and/or tumor vaccines, to greatly improve immunotherapeutic strategies against cancer. While investigators have utilized multiple vectors to LIGHT-up tumor tissues, there are still improvements needed and components to be found within a human tumor microenvironment that may impede translational efforts. This review addresses the current state of this field.

anlotinib alters tumor immune microenvironment by downregulating PD-L1 expression on vascular endothelial cells

Aberrant vascular network is a hallmark of cancer. However, the role of vascular endothelial cells (VECs)-expressing PD-L1 in tumor immune microenvironment and antiangiogenic therapy remains unclear. In this study, we used the specimens of cancer patients for immunohistochemical staining to observe the number of PD-L1⁺ CD34⁺ VECs and infiltrated immune cells inside tumor specimens. Immunofluorescence staining and flow cytometry were performed to observe the infiltration of CD8⁺ T cells and FoxP3⁺ T cells in tumor tissues. Here, we found that PD-L1 expression on VECs determined CD8⁺ T cells’, FoxP3⁺ T cells’ infiltration, and the prognosis of patients with lung adenocarcinoma. Anlotinib downregulated PD-L1 expression on VECs through the inactivation of AKT pathway, thereby improving the ratio of CD8/FoxP3 inside tumor and remolding the immune microenvironment. In conclusion, our results demonstrate that PD-L1 high expression on VECs inhibits the infiltration of CD8⁺ T cells, whereas promotes the aggregation of FoxP3⁺ T cells into tumor tissues, thus becoming an “immunosuppressive barrier”. Anlotinib can ameliorate the immuno-microenvironment by downregulating PD-L1 expression on VECs to inhibit tumor growth.

Spatial Characterization of Tumor Perfusion Properties from 3D DCE-US Perfusion Maps are Early Predictors of Cancer Treatment Response

There is a need for noninvasive repeatable biomarkers to detect early cancer treatment response and spare non-responders unnecessary morbidities and costs. Here, we introduce three-dimensional (3D) dynamic contrast enhanced ultrasound (DCE-US) perfusion map characterization as inexpensive, bedside and longitudinal indicator of tumor perfusion for prediction of vascular changes and therapy response. More specifically, we developed computational tools to generate perfusion maps in 3D of tumor blood flow, and identified repeatable quantitative features to use in machine-learning models to capture subtle multi-parametric perfusion properties, including heterogeneity. Models were developed and trained in mice data and tested in a separate mouse cohort, as well as early validation clinical data consisting of patients receiving therapy for liver metastases. Models had excellent (ROC-AUC > 0.9) prediction of response in pre-clinical data, as well as proof-of-concept clinical data. Significant correlations with histological assessments of tumor vasculature were noted (Spearman R > 0.70) in pre-clinical data. Our approach can identify responders based on early perfusion changes, using perfusion properties correlated to gold-standard vascular properties.

Tumour vessel remodelling: new opportunities in cancer treatment

Tumour growth critically depends on a supportive microenvironment, including the tumour vasculature. Tumour blood vessels are structurally abnormal and functionally anergic which limits drug access and immune responses in solid cancers. Thus, tumour vasculature has been considered an attractive therapeutic target for decades. However, with time, anti-angiogenic therapy has evolved from destruction to structural and functional rehabilitation as understanding of tumour vascular biology became more refined. Vessel remodelling or normalisation strategies which alleviate hypoxia are now coming of age having been shown to have profound effects on the tumour microenvironment. This includes improved tumour perfusion, release from immune suppression and lower metastasis rates. Nevertheless, clinical translation has been slow due to challenges such as the transient nature of current normalisation strategies, limited in vivo monitoring and the heterogeneity of primary and/or metastatic tumour environments, calling for more tailored approaches to vascular remodelling. Despite these setbacks, harnessing vascular plasticity provides unique opportunities for anti-cancer combination therapies in particular anti-angiogenic immunotherapy which are yet to reach their full potential.

Synergistic effect of immune checkpoint blockade and anti-angiogenesis in cancer treatment

Immune checkpoint inhibitor (ICI) activates host's anti-tumor immune response by blocking negative regulatory immune signals. A series of clinical trials showed that ICI could effectively induce tumor regression in a subset of advanced cancer patients. In clinical practice, a main concerning for choosing ICI is the low response rate. Even though multiple predictive biomarkers such as PD-L1 expression, mismatch-repair deficiency, and status of tumor infiltrating lymphocytes have been adopted for patient selection, frequent resistance to ICI monotherapy has not been completely resolved. However, some recent studies indicated that ICI resistance could be alleviated by combination therapy with anti-angiogenesis treatment. Actually, anti-angiogenesis therapy not only prunes blood vessel which is essential to cancer growth and metastasis, but also reprograms the tumor immune microenvironment. Preclinical studies demonstrated that the efficacy of combination therapy of ICI and anti-angiogenesis was superior to monotherapy. In mice model, combination therapy could effectively increase the ratio of anti-tumor/pro-tumor immune cell and decrease the expression of multiple immune checkpoints more than PD-1. Based on exciting results from preclinical studies, many clinical trials were deployed to investigate the synergistic effect of the combination therapy and acquired promising outcome. This review summarized the latest understanding of ICI combined anti-angiogenesis therapy and highlighted the advances of relevant clinical trials.

Role of Radiation Therapy in Modulation of the Tumor Stroma and Microenvironment

In recent decades, there has been substantial growth in our understanding of the immune system and its role in tumor growth and overall survival. A central finding has been the cross-talk between tumor cells and the surrounding environment or stroma. This tumor stroma, comprised of various cells, and extracellular matrix (ECM), has been shown to aid in suppressing host immune responses against tumor cells. Through immunosuppressive cytokine secretion, metabolic alterations, and other mechanisms, the tumor stroma provides a complex network of safeguards for tumor proliferation. With recent advances in more effective, localized treatment, radiation therapy (XRT) has allowed for strategies that can effectively alter and ablate tumor stromal tissue. This includes promoting immunogenic cell death through tumor antigen release to increasing immune cell trafficking, XRT has a unique advantage against the tumoral immune evasion mechanisms that are orchestrated by stromal cells. Current studies are underway to elucidate pathways within the tumor stroma as potential targets for immunotherapy and chemoradiation. This review summarizes the effects of tumor stroma in tumor immune evasion, explains how XRT may help overcome these effects, with potential combinatorial approaches for future treatment modalities.

An antiestrogen-binding protein in human tissues

Although nonsteroidal antiestrogens of the triphenylethylene type are generally considered to act through the estrogen receptor, some observations suggest that estrogen target tissues may also contain a binding protein specific for these compounds. The data so far reported, however, are also consistent with ligand-induced changes in conformation or in the state of aggregation of the estrogen receptor. The studies reported here demonstrate the existence of a protein in human myometrial cytosol which binds 1-[4-(2-dimethylaminoethoxy)phenyl]1,2-diphenylbut-1(Z)-ene ([3H]tamoxifen) with high affinity (Kd = 2.3 X 10(-9) M). This protein exhibits striking specificity for nonsteroidal antiestrogens. Estradiol competes weakly for bound [3H]tamoxifen, while other estrogens and nonestrogenic steroid hormones do not compete at all. Sedimentation analysis and molecular sieve chromatography indicate that the antiestrogen-binding protein is a larger species than the estrogen receptor and elutes from DEAE-Sephacel at a lower KCl concentration (0.03 M) than the estrogen receptor (0.15 M). Differential thermal stability of the estrogen receptor and the antiestrogen-binding protein was demonstrable in the absence of added ligand. The antiestrogen-binding protein was ubiquitous, being present in many tissues where estrogen receptor was undetectable. These findings support the separate existence of an antiestrogen-binding protein.