Vascular Normalization Research Articles

Abstract A041: Vascular normalization improves the delivery and efficacy of CAR-T cells in mouse brain cancers

Abstract Introduction: Chimeric antigen receptor (CAR)-T cell therapy has revolutionized the treatment of hematological malignancies, but its efficacy in patients with glioblastoma (GBM) and other solid tumors is limited due to poor tumor infiltration and an immunosuppressive tumor microenvironment (TME). We have previously shown that blocking vascular endothelial growth factor (VEGF) signaling can normalize tumor vessels, convert the immunosuppressive TME into an immunostimulatory environment, and enhance the efficacy of immunotherapy. This study aimed to investigate whether combining anti-VEGF therapy (B20) with EGFRvIII-targeting CAR-T cell treatment could improve delivery and effectiveness in immunocompetent orthotopic GBM mouse models. Methods: The study utilized two syngeneic mouse GBM cell lines (CT2A and GSC005) engineered to express EGFRvIII, a common neoantigen in human GBM. CAR-T cells were designed to target EGFRvIII. GBM-bearing mice were treated with B20[LS1] followed by EGFRvIII-CAR-T injection. Intravital imaging using two-photon microscopy was employed to track CAR-T cell infiltration into the tumor, while flow cytometry was used to measure the number and function of CAR-T and other immune cells. Results: The combination of B20 and CAR-T cell treatment significantly prolonged the survival of GBM-bearing mice compared to CAR-T cell therapy alone. Intravital imaging revealed that B20 normalized tumor vasculature, leading to a four-fold increase in the number of infiltrated CAR-T cells compared to CAR-T therapy without B20. Flow cytometry analysis showed an increased population of IL-2+ or IFN-γ+ CAR-T cells, indicating that B20 enhanced the anti-tumor function of injected CAR-T cells. Additionally, B20 therapy increased the population of endogenous lymphocytes, specifically Granzyme B+ TNF-α+ CD8 T cells (Cytotoxic T lymphocytes; CTLs) while decreasing FoxP3+ CD4 T cells (Regulatory T cells; Tregs). This indicated that the TME was remodeled to enhance the effect of CAR-T therapy. Conclusions: Our study demonstrated that combining B20 with CAR-T therapy improved their efficacy in GBM mouse models by enhancing CAR-T cell infiltration and reprogramming the TME to activate CAR-T cells and effector T cells. These findings provide compelling evidence for clinically evaluating the combination of anti-VEGF agents with CAR-T cells in GBM patients. We are now building on this approach to enhance CAR-T therapy for breast cancer brain metastasis. We are testing TNBC-targeting CAR-T therapy in murine TNBC-BrM[LS2] using a similar approach. Our hypothesis is that similar to the GBM results, anti-VEGF therapy and adoptive transfer of TNBC-targeting CAR-T cells [LS3] will improve CAR-T cell infiltration, delay tumor growth and prolong survival. This strategy has the potential to enhance emerging cellular immunotherapies' effectiveness in the brain tumor microenvironment. Citation Format: Vasiliki Salameti, Xinyue Dong, Jun Ren, Zohreh Amoozgar, Somin Lee, Meenal Datta, Sylvie Roberge, Mark Duquette, Dai Fukumura, Rakesh K. Jain. Vascular normalization improves the delivery and efficacy of CAR-T cells in mouse brain cancers [abstract]. In: Proceedings of the AACR Special Conference on Brain Cancer; 2023 Oct 19-22; Minneapolis, Minnesota. Philadelphia (PA): AACR; Cancer Res 2024;84(5 Suppl_1):Abstract nr A041.

Targeting PKM2 signaling cascade with salvianic acid A normalizes tumor blood vessels to facilitate chemotherapeutic drug delivery

Aberrant tumor blood vessels are prone to propel the malignant progression of tumors, and targeting abnormal metabolism of tumor endothelial cells emerges as a promising option to achieve vascular normalization and antagonize tumor progression. Herein, we demonstrated that salvianic acid A (SAA) played a pivotal role in contributing to vascular normalization in the tumor-bearing mice, thereby improving delivery and effectiveness of the chemotherapeutic agent. SAA was capable of inhibiting glycolysis and strengthening endothelial junctions in the human umbilical vein endothelial cells (HUVECs) exposed to hypoxia. Mechanistically, SAA was inclined to directly bind to the glycolytic enzyme PKM2, leading to a dramatic decrease in endothelial glycolysis. More importantly, SAA improved the endothelial integrity via activating the β-Catenin/Claudin-5 signaling axis in a PKM2-dependent manner. Our findings suggest that SAA may serve as a potent agent for inducing tumor vascular normalization.

The Combination of Anti-CD47 Antibody with CTLA4 Blockade Enhances Anti-Tumor Immunity in Non-Small Cell Lung Cancer via Normalization of Tumor Vasculature and Reprogramming of the Immune Microenvironment.

In solid tumors, the formidable anti-tumor impact resulting from blocking the "don't eat me" signal, arising from CD47-SIRPα interaction, is constrained, especially compared to its efficacy in hematopoietic malignancies. Activating macrophage anti-tumor activity not only necessitates the inhibition of the "don't eat me" signal, but also the activation of the "eat me" (pre-phagocyte) signal. Intriguingly, the cytotoxic T-lymphocyte-associated antigen 4 (CTLA4) antibody (Ab) has been identified to stimulate Fc receptor-mediated active phagocytes in the tumor microenvironment, thereby generating "eat me" signals. This study postulates that concurrently targeting CD47 and CTLA4 could intensify the anti-tumor effects by simultaneously blocking the "don't eat me" signal while triggering the "eat me" signal. The experimental data from this investigation confirm that the combined targeting of CD47 and CTLA4 enhances immunity against solid tumors in LLC cell-transplanted tumor-bearing mice. This effect is achieved by reducing myeloid-derived suppressor cell infiltration while increasing the presence of effector memory CD8+ T cells, NK1.1+ CD8+ T cells, and activated natural killer T cells. Meanwhile, combination therapy also alleviated anemia. Mechanistically, the anti-CD47 Ab is shown to upregulate CTLA4 levels in NSCLC cells by regulating Foxp1. Furthermore, targeting CD47 is demonstrated to promote tumor vascular normalization through the heightened infiltration of CD4+ T cells. These findings suggest that the dual targeting of CD47 and CTLA4 exerts anti-tumor effects by orchestrating the "eat me" and "don't eat me" signals, reshaping the immune microenvironment, and fostering tumor vascular normalization. This combined therapeutic approach emerges as a potent strategy for effectively treating solid tumors.

Induction sintilimab and chemotherapy followed by concurrent chemoradiotherapy for locally advanced esophageal cancer: a proof-of-concept, single-arm, multicenter, phase 2 trial

Concurrent chemoradiotherapy is the standard nonoperative treatment for locally advanced esophageal squamous cell carcinoma. However, local recurrence is still the main failure pattern, accounting for more than half of all treatment failures, indicating that the sensitivity of radiotherapy still needs to be improved. This trial aimed at demonstrating whether PD-1 inhibitors followed by chemoradiotherapy could promote esophageal tumor vascular normalization, alleviate hypoxia, and thus enhance radiosensitivity and improve local control. We did a multicenter, single-arm, phase 2 trial in China. Patients with locally advanced esophageal cancer were enrolled in this study. In induction phase, patients received two cycles of sintilimab, paclitaxel and carboplatin once per 21 days. In concurrent phase, patients were treated with five cycles of carboplatin and paclitaxel once per week concurrent with radiotherapy of 50.4Gy delivered in 28 fractions. The primary endpoint was 2-year local control rate. Hypoxia and vessel normalization was assessed before and after induction phase using immunofluorescence and perfusion CT. This trial is registered with ClinicalTrials.gov (NCT03985046). Seventy-five patients with esophageal cancer were enrolled in this study between October 2019 and April 2021. The median follow-up of surviving patients was 33.6 months (IQR 29.3-35.7). The 2-year local control rate was 81.7% (95% confidence interval, 72.7%-90.7%), which was much higher than that in concurrent chemoradiation only (71.3%) in previous studies. Vascular normalization and hypoxia alleviation were observed in both biopsy specimens and perfusion CT. The addition of induction immunotherapy to standard concurrent chemoradiotherapy could improve radiosensitivity for locally advanced esophageal cancer as non-surgical treatment. New treatment combination led to higher local control rate through promoting vascular normalization and alleviating hypoxia. Our findings suggest that induction immunotherapy followed by concurrent chemoradiotherapy could be a potential option in future treatment. National Natural Science Foundation of China and Shanghai Rising-Star Program.

A Lactate-Depleting metal organic framework-based nanocatalyst reinforces intratumoral T cell response to boost anti-PD1 immunotherapy

Infiltration and activation of intratumoral T lymphocytes are critical for immune checkpoint blockade (ICB) therapy. Unfortunately, the low tumor immunogenicity and immunosuppressive tumor microenvironment (TME) induced by tumor metabolic reprogramming cooperatively hinder the ICB efficacy. Herein, we engineered a lactate-depleting MOF-based catalytic nanoplatform (LOX@ZIF-8@MPN), encapsulating lactate oxidase (LOX) within zeolitic imidazolate framework-8 (ZIF-8) coupled with a coating of metal polyphenol network (MPN) to reinforce T cell response based on a “two birds with one stone” strategy. LOX could catalyze the degradation of the immunosuppressive lactate to promote vascular normalization, facilitating T cell infiltration. On the other hand, hydrogen peroxide (H2O2) produced during lactate depletion can be transformed into anti-tumor hydroxyl radical (•OH) by the autocatalytic MPN-based Fenton nanosystem to trigger immunogenic cell death (ICD), which largely improved the tumor immunogenicity. The combination of ICD and vascular normalization presents a better synergistic immunopotentiation with anti-PD1, inducing robust anti-tumor immunity in primary tumors and recurrent malignancies. Collectively, our results demonstrate that the concurrent depletion of lactate to reverse the immunosuppressive TME and utilization of the by-product from lactate degradation via cascade catalysis promotes T cell response and thus improves the effectiveness of ICB therapy.

Clinical Potential of YY1-Hypoxia Axis for Vascular Normalization and to Improve Immunotherapy

Abnormal vasculature in solid tumors causes poor blood perfusion, hypoxia, low pH, and immune evasion. It also shapes the tumor microenvironment and affects response to immunotherapy. The combination of antiangiogenic therapy and immunotherapy has emerged as a promising approach to normalize vasculature and unlock the full potential of immunotherapy. However, the unpredictable and redundant mechanisms of vascularization and immune suppression triggered by tumor-specific hypoxic microenvironments indicate that such combination therapies need to be further evaluated to improve patient outcomes. Here, we provide an overview of the interplay between tumor angiogenesis and immune modulation and review the function and mechanism of the YY1-HIF axis that regulates the vascular and immune tumor microenvironment. Furthermore, we discuss the potential of targeting YY1 and other strategies, such as nanocarrier delivery systems and engineered immune cells (CAR-T), to normalize tumor vascularization and re-establish an immune-permissive microenvironment to enhance the efficacy of cancer therapy.

Therapy-induced modulation of tumor vasculature and oxygenation in a murine glioblastoma model quantified by deep learning-based feature extraction

Glioblastoma presents characteristically with an exuberant, poorly functional vasculature that causes malperfusion, hypoxia and necrosis. Despite limited clinical efficacy, anti-angiogenesis resulting in vascular normalization remains a promising therapeutic approach. Yet, fundamental questions concerning anti-angiogenic therapy remain unanswered, partly due to the scale and resolution gap between microscopy and clinical imaging and a lack of quantitative data readouts. To what extend does treatment lead to vessel regression or vessel normalization and does it ameliorate or aggravate hypoxia? Clearly, a better understanding of the underlying mechanisms would greatly benefit the development of desperately needed improved treatment regimens. Here, using orthotopic transplantation of Gli36 cells, a widely used murine glioma model, we present a mesoscopic approach based on light sheet fluorescence microscopic imaging of wholemount stained tumors. Deep learning-based segmentation followed by automated feature extraction allowed quantitative analyses of the entire tumor vasculature and oxygenation statuses. Unexpectedly in this model, the response to both cytotoxic and anti-angiogenic therapy was dominated by vessel normalization with little evidence for vessel regression. Equally surprising, only cytotoxic therapy resulted in a significant alleviation of hypoxia. Taken together, we provide and evaluate a quantitative workflow that addresses some of the most urgent mechanistic questions in anti-angiogenic therapy.

A phase 1b study of the OxPhos inhibitor ME-344 in combination with bevacizumab in refractory metastatic colorectal cancer.

TPS222 Background: ME-344 is a synthetic small molecule that inhibits oxidative phosphorylation, resulting in energy starvation and cell death via caspase-dependent and -independent mechanisms. The activity of mitochondrial inhibitors is enhanced when mitochondrial respiration is upregulated, a situation achieved in solid tumors by inducing vascular normalization and hypoxia correction with antiangiogenics. In a CT26 colon carcinoma syngeneic murine model, ME-344 in combination with regorafenib showed significantly reduced tumor growth compared to regorafenib alone (Navarro et al. Cell Reports. 2016;15:2705). A randomized phase 0/1 window of opportunity study in HER2-negative breast cancer showed significant decrease in the proliferation marker Ki67 in patients administered ME-344 plus bevacizumab vs. bevacizumab alone (Quintela-Fandino et al, Clin Cancer Res. 2020;26:35). The current study evaluates the safety and efficacy of ME-344 in combination with bevacizumab in refractory metastatic colorectal cancer, a clinical setting where continued antiangiogenic inhibition has established benefit. Prior phase 1-1b studies of ME-344 as a single agent and in combination have established the RP2D at 10 mg/kg when administered intravenously weekly. Methods: This is an open-label phase 1b study in patients ≥18 years old with metastatic colorectal cancer after failure of standard therapies, including fluoropyrimidine-, irinotecan-, and oxaliplatin-based regimens, anti-EGFR if RAS wild-type, PD/L-1-blocking antibody if MSI-H/dMMR, and BRAF-targeted therapy if BRAF V600E mutated. Other key eligibility criteria include measurable disease, ECOG performance status 0-1, adequate bone marrow, liver and renal function, no uncontrolled brain metastatic disease, no peripheral neuropathy grade ≥2, no uncontrolled hypertension or diabetes, and no increased hemorrhagic risk. Enrollment will proceed in 2 cohorts of 20 patients each. Cohort 1 will be administered ME-344 at 10 mg/kg on days 1, 8, and 15 of a 28-day cycle and bevacizumab 5 mg/kg on days 1 and 15. Cohort 2 will be administered ME-344 at 10 mg/kg and bevacizumab 5 mg/kg both on days 1 and 15 of a 28-day cycle. Treatment will continue until disease progression or intolerance. Tumor assessment is performed every 8 weeks for 6 months and then every 3 months using RECIST-1 criteria. The primary endpoint is 16-week PFS. Secondary endpoints are PFS, response rate, and safety. Correlative analysis will evaluate treatment-related metabolic response. The study is actively enrolling, funded by MEI Pharma, and registered under NCT02100007. Clinical trial information: NCT02100007 .

Antagonism of regulatory ISGs enhances the anti-melanoma efficacy of STING agonists.

Stimulator of Interferon Genes (STING) is a dsDNA sensor that triggers type I inflammatory responses. Recent data from our group and others support the therapeutic efficacy of STING agonists applied intratumorally or systemically in a range of murine tumor models, with treatment benefits associated with tumor vascular normalization and improved immune cell recruitment and function within the tumor microenvironment (TME). However, such interventions are rarely curative and STING agonism coordinately upregulates expression of immunoregulatory interferon-stimulated genes (ISGs) including Arg2, Cox2, Isg15, Nos2, and Pdl1 that may limit treatment benefits. We hypothesized that combined treatment of melanoma-bearing mice with STING agonist ADU-S100 together with antagonists of regulatory ISGs would result in improved control of tumor growth vs. treatment with ADU-S100 alone. Mice bearing either B16 (BRAFWTPTENWT) or BPR20 (BRAFV600EPTEN-/-) melanomas were treated with STING agonist ADU-S100 plus various inhibitors of ARG2, COX2, NOS2, PD-L1, or ISG15. Tumor growth control and changes in the TME were evaluated for combination treatment vs ADU-S100 monotherapy by tumor area measurements and flow cytometry/transcriptional profiling, respectively. In the B16 melanoma model, we noted improved antitumor efficacy only when ADU-S100 was combined with neutralizing/blocking antibodies against PD-L1 or ISG15, but not inhibitors of ARG2, COX2, or NOS2. Conversely, in the BPR20 melanoma model, improved tumor growth control vs. ADU-S100 monotherapy was only observed when combining ADU-S100 with ARG2i, COX2i, and NOS2i, but not anti-PD-L1 or anti-ISG15. Immune changes in the TME associated with improved treatment outcomes were subtle but included increases in proinflammatory innate immune cells and activated CD8+CD69+ T cells and varied between the two tumor models. These data suggest contextual differences in the relative contributions of individual regulatory ISGs that serve to operationally limit the anti-tumor efficacy of STING agonists which should be considered in future design of novel combination protocols for optimal treatment benefit.

Hypoxia-activated prodrug and antiangiogenic therapies cooperatively treat pancreatic cancer but elicit immunosuppressive G-MDSC infiltration.

We previously showed that ablation of tumor hypoxia can sensitize tumors to immune checkpoint blockade (ICB). Here, we used a Kras+/G12D TP53+/R172H Pdx1-Cre-derived (KPC-derived) model of pancreatic adenocarcinoma to examine the tumor response and adaptive resistance mechanisms involved in response to 2 established methods of hypoxia-reducing therapy: the hypoxia-activated prodrug TH-302 and vascular endothelial growth factor receptor 2 (VEGFR-2) blockade. The combination of both modalities normalized tumor vasculature, increased DNA damage and cell death, and delayed tumor growth. In contrast with prior cancer models, the combination did not alleviate overall tissue hypoxia or sensitize these KPC tumors to ICB therapy despite qualitative improvements to the CD8+ T cell response. Bulk tumor RNA sequencing, flow cytometry, and adoptive myeloid cell transfer suggested that treated tumor cells increased their capacity to recruit granulocytic myeloid-derived suppressor cells (G-MDSCs) through CCL9 secretion. Blockade of the CCL9/CCR1 axis could limit G-MDSC migration, and depletion of Ly6G-positive cells could sensitize tumors to the combination of TH-302, anti-VEGFR-2, and ICB. Together, these data suggest that pancreatic tumors modulate G-MDSC migration as an adaptive response to vascular normalization and that these immunosuppressive myeloid cells act in a setting of persistent hypoxia to maintain adaptive immune resistance.

TET2-mediated tumor cGAS triggers endothelial STING activation to regulate vasculature remodeling and anti-tumor immunity in liver cancer

Induction of tumor vascular normalization is a crucial measure to enhance immunotherapy efficacy. cGAS-STING pathway is vital for anti-tumor immunity, but its role in tumor vasculature is unclear. Herein, using preclinical liver cancer models in Cgas/Sting-deficient male mice, we report that the interdependence between tumor cGAS and host STING mediates vascular normalization and anti-tumor immune response. Mechanistically, TET2 mediated IL-2/STAT5A signaling epigenetically upregulates tumor cGAS expression and produces cGAMP. Subsequently, cGAMP is transported via LRRC8C channels to activate STING in endothelial cells, enhancing recruitment and transendothelial migration of lymphocytes. In vivo studies in male mice also reveal that administration of vitamin C, a promising anti-cancer agent, stimulates TET2 activity, induces tumor vascular normalization and enhances the efficacy of anti-PD-L1 therapy alone or in combination with IL-2. Our findings elucidate a crosstalk between tumor and vascular endothelial cells in the tumor immune microenvironment, providing strategies to enhance the efficacy of combinational immunotherapy for liver cancer.

IRGD-mediated liposomal nanoplatforms for improving hepatocellular carcinoma targeted combination immunotherapy and monitoring tumor response via IVIM-MRI.

The combination therapy of targeted treatments and immune checkpoint blockade (ICB) holds great promise for hepatocellular carcinoma (HCC) treatment. However, challenges such as immunogenicity, off-target toxicity of ICB antibodies, low drug co-delivery efficiency, and lack of effective biomarkers to monitor treatment response limit the efficacy of existing targeted immunotherapies. Herein, we synthesized iRGD-modified pH-sensitive liposomal nanoparticles co-encapsulating lenvatinib (Len) and the small molecule PD-1/PD-L1 inhibitor BMS-202 (iRGD-lip@Len/BMS-202) to address issues related to inadequate tumor enrichment and distinct pharmacokinetics of these drugs. Furthermore, intravoxel incoherent motion-magnetic resonance imaging (IVIM-MRI), which is calculated using a biexponential model, can simultaneously reflect both the diffusion of water molecules within the tissue and the microcirculatory perfusion of capillaries. Consequently, we further assessed the feasibility of using IVIM-MRI to monitor the cancer treatment response in nanodrug therapy. These results demonstrated that the iRGD-targeted liposomal nanodrug effectively accumulated in tumors and released in acidic microenvironments. The sustained release of Len facilitated tumor vascular normalization, decreased the presence of Tregs and MDSCs and activated the IFN-γ signaling pathway. This led to increased PD-L1 expression in tumor cells, enhancing the sensitivity of BMS-202. Consequently, there was a synergistic amplification of antitumor immune therapy, resulting in the shrinkage of subcutaneous and orthotopic HCC and inhibition of lung metastasis. Furthermore, IVIM-MRI technology facilitated the non-invasive monitoring of the tumor microenvironment (TME), revealing critical therapeutic response indicators such as the normalization of tumor blood vessels and the degree of hypoxia. Collectively, the combination of Food and Drug Administration (FDA)-approved drugs with iRGD-modified liposomes presents a promising strategy for HCC treatment. Simultaneously, IVIM-MRI provides a non-invasive method to accurately predict the response to this nanodrug.

Chinese Herbal Compound Xiaoliu Pingyi Recipe Inhibits the Growth of Lung Adenocarcinoma by Regulating the Tumor Vascular Microenvironment.

The traditional Chinese medicine (TCM) Xiaoliu Pingyi recipe (XLPYR) has been clinically used for several decades, demonstrating favorable therapeutic effects. However, the underlying regulatory mechanisms remain unclear. The aim of this study was to explore the anti-tumor effects of XLPYR and its regulatory role in the vascular microenvironment through in vivo and in vitro experiment. In the in vivo study, a C57BL/6J mouse model of lung adenocarcinoma (LUAD) allografts was established, and various interventions were administered for 14 days (Model group: administered normal saline via oral gavage; Pemetrexed (PEM) group: intraperitoneally injected with a solution of pemetrexed, once every 3d; XLPYR group: administered XLPYR via oral gavage; Combination (COMBI) group: received XLPYR via oral gavage simultaneously with intraperitoneal injection of pemetrexed solution). Tumor volume and weight were then compared among the groups. The impact of XLPYR on the tumor vascular microenvironment was assessed using immunohistochemistry staining. In the in vitro study, XLPYR-containing serum was prepared by oral administration to SD rats. The CCK-8 assay evaluated the effect of the serum on the proliferation of normal lung epithelial BEAS-2B cells and LUAD A549 cells, determining the optimal intervention concentrations. The cell migration and invasion abilities were evaluated using the wound-healing assay and Transwell assay, respectively. Finally, ELISA assay measured VEGF secretion levels in the LUAD cell supernatant, and RT-qPCR and Western Blot were employed to detect differences in HIF-1α, VEGFA, Ang-2, and PI3K/Akt mRNA and protein expression levels in both in vivo and in vitro experiments. In the in vivo study, XLPYR significantly inhibited the growth of mice LUAD allografts, with enhanced anti-tumor effects observed with prolonged drug intervention. Immunohistochemistry staining revealed reduced MVD and increased pericyte coverage in all intervention groups. Regarding vascular function, FITC-Dextran extravasation in the tumor tissues of the Model group was significantly higher than in the intervention groups, particularly with lower extravasation in the COMBI group compared to the PEM group. In the in vitro study, XLPYR demonstrated a time- and concentration-dependent inhibitory effect on LUAD cells, and with greater sensitivity in inhibiting LUAD cells compared to BEAS-2B cells. The wound-healing assay and Transwell assay confirmed that XLPYR significantly suppressed the migration and invasion abilities of LUAD cells. ELISA experiments further revealed a significant decrease in VEGF expression in the supernatant of each intervention group. RT-qPCR and Western Blot results showed consistent findings between the in vivo and in vitro experiments. HIF-1α, VEGFA, and Ang-2 mRNA and protein expression levels were significantly downregulated in the PEM group, XLPYR group, and COMBI group. There were no significant differences in the expression of PI3K and Akt mRNA and total protein, but the expression levels of phosphorylated p-PI3K and p-Akt were notably downregulated. XLPYR significantly inhibited C57BL/6J mouse LUAD allograft growth and improved the vascular microenvironment, thereby intervening in tumor angiogenesis and inducing vascular normalization. It suppressed LUAD cell proliferation, migration, and invasion, while reducing VEGF concentration in the cell supernatant. The regulatory mechanism may involve inhibiting PI3K/Akt protein phosphorylation and downregulating angiogenesis-related factors, such as HIF-1α, VEGF, and Ang-2.

Targeting vascular normalization: a promising strategy to improve immune-vascular crosstalk in cancer immunotherapy.

Blood vessels are a key target for cancer therapy. Compared with the healthy vasculature, tumor blood vessels are extremely immature, highly permeable, and deficient in pericytes. The aberrantly vascularized tumor microenvironment is characterized by hypoxia, low pH, high interstitial pressure, and immunosuppression. The efficacy of chemotherapy, radiotherapy, and immunotherapy is affected by abnormal blood vessels. Some anti-angiogenic drugs show vascular normalization effects in addition to targeting angiogenesis. Reversing the abnormal state of blood vessels creates a normal microenvironment, essential for various cancer treatments, specifically immunotherapy. In addition, immune cells and molecules are involved in the regulation of angiogenesis. Therefore, combining vascular normalization with immunotherapy may increase the efficacy of immunotherapy and reduce the risk of adverse reactions. In this review, we discussed the structure, function, and formation of abnormal vessels. In addition, we elaborated on the role of the immunosuppressive microenvironment in the formation of abnormal vessels. Finally, we described the clinical challenges associated with the combination of immunotherapy with vascular normalization, and highlighted future research directions in this therapeutic area.

CCL2 chemokine inhibition primes the tumor vasculature for improved nanomedicine delivery and efficacy

Blood vessel functionality is crucial for efficient tumor-targeted drug delivery. Heterogeneous distribution and perfusion of angiogenic blood vessels contribute to suboptimal accumulation of (nano-) therapeutics in tumors and metastases. To attenuate pathological angiogenesis, an L-RNA aptamer inhibiting the CC motif chemokine ligand 2 (CCL2) was administered to mice bearing orthotopic 4T1 triple-negative breast cancer tumors. The effect of CCL2 inhibition on tumor blood vessel functionality and tumor-targeted drug delivery was evaluated via multimodal and multiscale optical imaging, employing fluorophore-labeled polymeric (10 nm) and liposomal (100 nm) nanocarriers. Anti-CCL2 treatment induced a dose-dependent anti-angiogenic effect, reflected by a decreased relative blood volume, increased blood vessel maturity and functionality, and reduced macrophage infiltration, accompanied by a shift in the polarization of tumor-associated macrophages (TAM) towards a less M2-like and more M1-like phenotype. In line with this, CCL2 inhibitor treatment improved the delivery of polymers and liposomes to tumors, and enhanced the antitumor efficacy of free and liposomal doxorubicin. Together, these findings demonstrate that blocking the CCL2-CCR2 axis modulates TAM infiltration and polarization, resulting in vascular normalization and improved tumor-targeted drug delivery.

Cold to Hot: Tumor Immunotherapy by Promoting Vascular Normalization Based on PDGFB Nanocomposites.

Immunotherapy is a promising cancer therapeutic strategy. However, the "cold" tumor immune microenvironment (TIME), characterized by insufficient immune cell infiltration and immunosuppressive status, limits the efficacy of immunotherapy. Tumor vascular abnormalities due to defective pericyte coverage aregradually recognized as a profound determinant in "cold" TIME establishment by hindering immune cell trafficking. Recently, several vascular normalization strategies by improving pericyte coverage have been reported, whereas have unsatisfactory efficacy and high rates of resistance. Herein, a combinatorial strategy to induce tumor vasculature-targeted pericyte recruitment and zinc ion-mediated immune activation with aplatelet-derived growth factor B (PDGFB)-loaded, cyclo (Arg-Gly-Asp-D-Phe-Lys)-modified zeolitic imidazolate framework 8 (PDGFB@ZIF8-RGD) nanoplatform is proposed. PDGFB@ZIF8-RGD effectively induced tumor vascular normalization, which facilitated trafficking and infiltration of immune effector cells, including natural killer (NK) cells, M1-like macrophages and CD8+ T cells, into tumor microenvironment. Simultaneously, vascular normalization promoted the accumulation of zinc ions inside tumors to trigger effector cell immune activation and effector molecule production. The synergy between these two effects endowed PDGFB@ZIF8-RGD with superior capabilities in reprogramming the "cold" TIME to a "hot" TIME, thereby initiating robust antitumor immunity and suppressing tumor growth. This combinatorial strategy for improving immune effector cell infiltration and activation is a promising paradigm for solid tumor immunotherapy.

Identification of the consistently differential expressed hub mRNAs and proteins in lung adenocarcinoma and construction of the prognostic signature: a multidimensional analysis.

This study aimed to elucidate the consistency of differentially expressed hub mRNAs and proteins in lung adenocarcinoma (LUAD) across populations and to construct a comprehensive LUAD prognostic signature. The transcriptomic and proteomics data from different populations were standardized and analyzed using the same criteria to identify the consistently differential expressed mRNAs and proteins across genders and races. We then integrated prognosis-related mRNAs with clinical, pathological, and EGFR (epidermal growth factor receptor) mutation data to construct a survival model, subsequently validating it across populations. Through plasma proteomics, plasma proteins that consistently differential expressed with LUAD tissues were screened and validated, with their associations discerned by measuring expressions in tumor tissues and tumor vascular normalization. The consistency rate of differentially expressed mRNAs and proteins was ~20-40%, with ethnic factors leading to about 40-60% consistency of differentially expressed mRNA or protein across populations. The survival model based on the identified eight hub mRNAs as well as stage, smoking status, and EGFR mutations, demonstrated good prognostic prediction capabilities in both Western and East Asian populations, with a higher number of unfavorable variables indicating poorer LUAD prognosis. Notably, GPI expression in tumor tissues was inversely correlated with vascular normalization and positively correlated with plasma GPI expression. Our study underscores the significance of integrating transcriptomics and proteomics data, emphasizing the need to account for genetic diversity among ethnic groups. The developed survival model may offer a holistic perspective on LUAD progression, enhancing prognosis and therapeutic strategies.

Computational Multi-Scale Modeling of Drug Delivery into an Anti-Angiogenic Therapy-Treated Tumor.

The present study develops a numerical model, which is the most complex one, in comparison to previous research to investigate drug delivery accompanied by the anti-angiogenesis effect. This paper simulates intravascular blood flow and interstitial fluid flow using a dynamic model. The model accounts for the non-Newtonian behavior of blood and incorporates the adaptation of the diameter of a heterogeneous microvascular network derived from modeling the evolution of endothelial cells toward a circular tumor sprouting from two-parent vessels, with and without imposing the inhibitory effect of angiostatin on a modified discrete angiogenesis model. The average solute exposure and its uniformity in solid tumors of different sizes are studied by numerically solving the convection-diffusion equation. Three different methodologies are considered for simulating anti-angiogenesis: modifying the capillary network, updating the transport properties, and considering both microvasculature and transport properties modifications. It is shown that anti-angiogenic therapy decreases drug wash-out in the periphery of the tumor. Results show the decisive role of microvascular structure, particularly its distribution, and interstitial transport properties modifications induced via vascular normalization on the quality of drug delivery, such that it is improved by 39% in uniformity by the second approach in R = 0.2 cm.

CTNI-63. A PHASE IIA CLINICAL TRIAL FOR COMBINATION OF NAVIGATION-GUIDE FOCUSED ULTRASOUND AND BEVACIZUMAB FOR PATIENTS WITH RECURRENT GLIOBLASTOMA

Abstract INTRODUCTION Bevacizumab (BEV), a vascular normalizing therapy that prolongs progression free survival (PFS) for patients with recurrent glioblastoma (rGBM). Focused ultrasound combines with microbubbles (MB-FUS), an emergent technology for targeted blood-brain barrier opening (BBBO), is under investigation for its combinatorial effect with current standard of care for GBM treatment. This study aims to evaluate the safety and efficacy of BEV + MB-FUS for treating patients with rGBM. METHODS This is a phase IIa, open-label, single-arm clinical trial (NCT04446416). Eligible patients received BEV (10 mg/kg), then MB-FUS with a MB dosage of 0.1 ml/kg and neuronavigation-guided FUS system (NaviFUS-001, NaviFUS, Taiwan). The MB-FUS is planned to be an add-on modality to the bi-weekly BEV therapy for up to 18 sessions (FUSBEV, 34 weeks). RESULTS Six patients underwent total 156 FUS-BEVs (26 times per patients). Three patients (50%) completed the trial protocol, 2 of another 3 patients had disease progression during the treatments, the remaining one patient was in stable disease. The mean progression free survival was 7.5 months. Among the 156 sessions of MB-FUS, there were 3 (1.9%) transient focal scalp pain related to heating. An evaluation of the MB-FUS penetrated regions revealed a significant normalization effect of T2 signal hyperintensity at beam-concentrated areas. CONCLUSIONS The PFS-6 was 67% in this study. RESULTS have demonstrated the safety, feasibility, and a potential to decrease edema by the mechanism of enhance bevacizumab delivery to the treated site. The preliminary results are encouraging. More data are needed to proof the efficacy of BEV-FUS on rGBM patients.

Near‐Infrared‐II Nanoparticles for Vascular Normalization Combined with Immune Checkpoint Blockade via Photodynamic Immunotherapy Inhibit Uveal Melanoma Growth and Metastasis

AbstractPhotodynamic therapy (PDT) has been widely employed in tumor treatment due to its effectiveness. However, the tumor hypoxic microenvironment which is caused by abnormal vasculature severely limits the efficacy of PDT. Furthermore, the abnormal vasculature has been implicated in the failure of immunotherapy. In this study, a novel nanoparticle denoted as Combo‐NP is introduced, composed of a biodegradable NIR II fluorescent pseudo‐conjugate polymer featuring disulfide bonds within its main chain, designated as TPA‐BD, and the vascular inhibitor Lenvatinib. Combo‐NP exhibits dual functionality by not only inducing cytotoxic reactive oxygen species (ROS) to directly eliminate tumor cells but also eliciting immunogenic cell death (ICD). This ICD response, in turn, initiates a robust cascade of immune reactions, thereby augmenting the generation of cytotoxic T lymphocytes (CTLs). In addition, Combo‐NP addresses the issue of tumor hypoxia by normalizing the tumor vasculature. This normalization process enhances the efficacy of PDT while concurrently fostering increased CTLs infiltration within the tumor microenvironment. These synergistic effects synergize to potentiate the photodynamic‐immunotherapeutic properties of the nanoparticles. Furthermore, when combined with anti‐programmed death‐ligand 1 (PD‐L1), they showcase notable inhibitory effects on tumor metastasis. The findings in this study introduce an innovative nanomedicine strategy aimed at triggering systemic anti‐tumor immune responses for the treatment of Uveal melanoma.