Vascular normalization as a therapeutic strategy for malignant and nonmalignant disease

Angiogenesis causes and vasculogenic mimicry formation in the context of cancer stem cells

Tumor occurrence, development, invasion, and metastasis are regulated by multiple mechanisms. Among these, angiogenesis promotes tumor progression mainly by supplying tumor tissue and providing channels for tumor metastasis. Cancer stem cells (CSCs) are another important factor affecting tumor progression by involving in tumor initiation and development, while remaining insensitive to conventional antitumor treatments. Among treatment strategies for them, owing to the existence of alternative angiogenic pathways or the risk of damaging normal stem cells, the clinical effect is not ideal. Angiogenesis and CSCs may influence each other in this process. Tumor angiogenesis can support CSC self-renewal by providing a suitable microenvironment, whereas CSCs can regulate tumor neovascularization and mediate drug resistance to anti-angiogenic therapy. This review summarized the role of vascular niche formed by angiogenesis in CSC self-renewal and stemness maintenance, and the function of CSCs in endothelial progenitor cell differentiation and pro-angiogenic factor upregulation. We also elucidated the malignant loop between CSCs and angiogenesis promoting tumor progression. Additionally, we summarized and proposed therapeutic targets, including blocking tumor-derived endothelial differentiation, inhibiting pro-angiogenic factor upregulation, and directly targeting endothelial-like cells comprising CSCs. And we analyzed the feasibility of these strategies to identify more effective methods to improve tumor treatment.

CAVIN3 deficiency promotes vascular normalization in ocular neovascular disease via ERK/JAG1 signaling pathway

Multiple members of the caveolae-associated protein (Cavin) family are implicated in angiogenesis. However, the specific role of CAVIN3 in pathological angiogenesis within the eye remains unclear. The present study demonstrated that CAVIN3 knockdown in endothelial cells (ECs) promoted vascular normalization in ocular pathological neovascularization. Elevated CAVIN3 expression was observed in the ECs of retinal pigment epithelium/choroid complexes from patients with neovascular age-related macular degeneration and fibrovascular membranes from patients with proliferative diabetic retinopathy. Additionally, upregulated Cavin3 expression was detected in laser-induced choroidal neovascularization (CNV) and oxygen-induced retinopathy (OIR) mouse models. In both OIR and CNV mice, Cavin3 knockdown inhibited pathological neovascularization. Cavin3 deficiency further disrupted EC proliferation and vascular sprouting, thereby promoting vascular normalization by partially restoring microenvironmental hypoxia and reestablishing pericyte-EC interactions. Mechanistically, we demonstrated that zinc finger E-box-binding homeobox 1 (ZEB1) regulated CAVIN3 transcription in ECs under hypoxic conditions. CAVIN3 deficiency modulated pathological vascularization by inhibiting ERK phosphorylation, which downregulated jagged 1 (JAG1) expression. Conclusively, this study elucidated the protective role of endothelial CAVIN3 deficiency in pathological neovascularization models, addressing a gap in understanding the regulatory role of Cavins in angiogenesis. These findings suggested a therapeutic direction for ocular neovascular diseases.

Application of nanoparticles to target tumor blood vessels as a promising cancer treatment strategy

Cancer remains one of the leading causes of death worldwide and poses a significant challenge to effective treatment due to its complexity. Angiogenesis, the formation of new blood vessels, is a critical process in tumor growth and metastasis. The VEGF/VEGFR pathway plays a crucial role in regulating angiogenesis. Many anti-angiogenesis agents, including monoclonal antibodies and tyrosine kinase inhibitors, have been investigated for the treatment of various cancers. However, they face significant limitations such as limited bioavailability and drug resistance. Nanoparticles have emerged as a promising tool for effective drug delivery while minimizing systemic side effects. This review explores the application of nanoparticles dedicated to angiogenesis-targeted cancer therapy, particularly targeting the VEGF/VEGFR pathway. We describe drug delivery systems based on inorganic, lipid, and polymeric nanoparticles. Moreover, special attention is given to functionalized nanoparticles, which can precisely target numerous proteins that are significantly overexpressed on the surfaces of endothelial cells, tumors, or other cells in the tumor microenvironment. We summarize a series of nanoparticles designed for selective targeting of tumor vasculature, emphasizing the challenges faced by anti-angiogenic cancer therapies.

Overcoming chimeric antigen receptor-T (CAR-T) resistance with checkpoint inhibitors: Existing methods, challenges, clinical success, and future prospects : A comprehensive review

Immune checkpoint blockade is, as of today, the most successful form of cancer immunotherapy, with more than 43 % of cancer patients in the US eligible to receive it; however, only up to 12.5 % of patients respond to it. Similarly, adoptive cell therapy using bioengineered chimeric antigen receptorT (CAR-T) cells and T-cell receptor (TCR) cells has provided excellent responses against liquid tumours, but both forms of immunotherapy have encountered challenges within a tumour microenvironment that is both lacking in tumour-specific T-cells and is strongly immunosuppressive toward externally administered CAR-T and TCR cells. This review focuses on understanding approved checkpoint blockade and adoptive cell therapy at both biological and clinical levels before delving into how and why their combination holds significant promise in overcoming their individual shortcomings. The advent of next-generation checkpoint inhibitors has further strengthened the immune checkpoint field, and a special section explores how these inhibitors can address existing hurdles in combining checkpoint blockade with adoptive cell therapy and homing in on our cancer target for long-term immunity.

In vivo programming of adult pericytes aids axon regeneration by providing cellular bridges for SCI repair

Pericytes are contractile cells of the microcirculation that participate in wound healing after spinal cord injury (SCI). Thus far, the extent to which pericytes cause or contribute to axon growth and regeneration failure after SCI remains controversial. Here, we found that SCI leads to profound changes in vasculature architecture and pericyte coverage. We demonstrated that pericytes constrain sensory axons on their surface, causing detrimental structural and functional changes in adult dorsal root ganglion neurons that contribute to axon regeneration failure after SCI. Perhaps more excitingly, we discovered that in vivo programming of adult pericytes via local administration of platelet-derived growth factor BB (PDGF-BB) effectively promotes axon regeneration and recovery of hindlimb function by contributing to the formation of cellular bridges that span the lesion. Ultrastructural analysis showed that PDGF-BB induced fibronectin fibril alignment and extension, effectively converting adult pericytes into a permissive substrate for axon growth. In addition, PDGF-BB localized delivery positively affects the physical and chemical nature of the lesion environment, thereby creating more favorable conditions for SCI repair. Thus, therapeutic manipulation rather than wholesale ablation of pericytes can be exploited to prime axon regeneration and SCI repair.

Hypoxia Imaging in Lung Cancer: A PET-Based Narrative Review for Clinicians and Researchers

Background: Hypoxia plays a critical role in lung cancer progression and treatment resistance by contributing to aggressive tumor behavior and poor therapeutic response. Molecular imaging, particularly positron emission tomography (PET), has become an essential tool for noninvasive hypoxia detection, providing valuable insights into tumor biology and aiding in personalized treatment strategies. Objective: This narrative review explores recent advancements in PET imaging for detecting hypoxia in lung cancer, with a focus on the development, characteristics, and clinical applications of various radiotracers. Findings: Numerous PET-based hypoxia radiotracers have been investigated, each with distinct pharmacokinetics and imaging capabilities. Established tracers such as 18F-Fluoromisonidazole (18F-FMISO) remain widely used, while newer alternatives like 18F-Fluoroazomycin Arabinoside (18F-FAZA) and 18F-Flortanidazole (18F-HX4) demonstrate improved clearance and image contrast. Additionally, 64Cu-ATSM has gained attention for its rapid tumor uptake and hypoxia selectivity. The integration of PET with hybrid imaging modalities, such as PET/CT and PET/MRI, enhances the spatial resolution and functional interpretation, making hypoxia imaging a promising approach for guiding radiotherapy, chemotherapy, and targeted therapies. Conclusions: PET imaging of hypoxia offers significant potential in lung cancer diagnosis, treatment planning, and therapeutic response assessment. However, challenges remain, including tracer specificity, quantification variability, and standardization of imaging protocols. Future research should focus on developing next-generation radiotracers with enhanced specificity, optimizing imaging methodologies, and leveraging multimodal approaches to improve clinical utility and patient outcomes.

Lipid Nanoparticle Delivery System for Normalization of Tumor Microenvironment and Tumor Vascular Structure

Tumors grow by receiving oxygen and nutrients from the surrounding blood vessels, leading to rapid angiogenesis. This results in functionally and structurally abnormal vasculature characterized by high permeability and irregular blood flow, causing hypoxia within the tumor microenvironment (TME). Hypoxia exacerbates the secretion of pro-angiogenic factors such as vascular endothelial growth factor (VEGF), further perpetuating abnormal vessel formation. This environment compromises the efficacy of radiotherapy, immunotherapy, and chemotherapy. In this study, we developed a pH-sensitive liposome (PSL) system, termed OD_PSL@AKB, to co-deliver oxygen (OD) and razuprotafib (AKB-9778) to tumors. This system rapidly responds to the acidic TME to alleviate hypoxia and inhibit VEGF secretion, restoring VE-cadherin expression in hypoxic endothelial cell/cancer cell cocultures. Our findings highlight the potential of OD_PSL@AKB in normalizing tumor vasculature and improving therapeutic efficacy.

Pan-immune-inflammation value predicts immunotherapy response and reflects local antitumor immune response in rectal cancer

The pan-immune-inflammation value reflects the systemic inflammatory response, and tumor-infiltrating lymphocytes indicate a local immune response in rectal cancer. However, the association between systemic inflammatory response, as indicated by the pan-immune-inflammation value, and local immune responses in rectal cancer remains unclear. This study analyzed 915 treatment-naïve rectal cancer patients from the Peking Union Medical College Hospital and PLA General Hospital (PLAGH) cohorts who underwent radical surgery to investigate the relationship between the pan-immune-inflammation value and immune responses. Lower pan-immune-inflammation value was significantly associated with improved disease-free survival and cancer-specific survival. Multivariate Cox regression models identified the pan-immune-inflammation value as an independent prognostic factor. In the PLAGH cohort, patients with low pan-immune-inflammation values had higher immune cell levels, activated immune pathways, and increased expression of immune checkpoint genes according to RNA sequencing. Hematoxylin and eosin staining and immunohistochemical analysis revealed that lower pan-immune-inflammation value was associated with higher tumor-infiltrating lymphocyte density, more mature tertiary lymphoid structures, increased CD8+ T cells, and elevated human lymphocyte antigen class I expression. Conversely, patients with high pan-immune-inflammation values exhibited pathways linked to tumor progression, such as angiogenesis, epithelial-mesenchymal transition, hypoxia, KRAS signaling, and TGF-ß signaling. Among patients receiving anti-PD-1 therapy, responders had low pre- and post-treatment pan-immune-inflammation values. The pan-immune-inflammation value is a reliable marker associated with distinct immune microenvironment characteristics and can effectively predict disease-free survival, cancer-specific survival, and response to immunotherapy.

Vascular regional analysis unveils differential responses to anti-angiogenic therapy in pancreatic xenografts through macroscopic photoacoustic imaging

Background: Amongst the various imaging techniques that provide surrogate tumor radiographic indications to aid in planning, monitoring, and predicting outcomes of therapy, ultrasound-guided photoacoustic imaging (US-PAI) is a promising non-ionizing modality based on endogenous blood (hemoglobin) and blood oxygen saturation (StO₂) contrast. Adaptation of US-PAI to the clinical realm requires macroscopic system configurations for adequate depth visualization. Methods: Here we present a vascular regional analysis (VRA) methodology of obtaining areas of low and high vessel density regions within the tumor (LVD and HVD respectively) by frequency domain filtering of macroscopic PA images. In this work, we evaluated the various vascular and oxygenation profiles of different murine xenografts of pancreatic cancer (AsPC-1, MIA PaCa-2, and BxPC-3) that have varying levels of angiogenic potentials and investigated the effects of receptor tyrosine kinase inhibitor (sunitinib) on the tumor microvessel density and StO₂. Results: The administration of sunitinib resulted in transient deoxygenation and reduction in vessel density within 72 h in two (AsPC-1 and MIA PaCa-2) of the three tumor types. Utilizing VRA, the regional change in StO2 (∆StO2) revealed the preferential targeting of sunitinib in LVD regions in only the AsPC-1 tumors. We also identified the presence of vascular normalization (validated through immunohistochemistry) in the sunitinib treated AsPC-1 tumors at day 8 post-treatment where a significant increases in HVD ∆StO2 (~20%) were seen following the 72-hour time point, indicative of improved vessel flow and functionality. Treated AsPC-1 vasculature displayed increased maturity and functionality compared to non-treated tumors on day 8, while these same metrics showed no conclusive evidence of vascular normalization in MIA PaCa-2 or BxPC-3 tumors. Conclusion: Overall, VRA as a tool to monitor treatment response allowed us to identify time points of vascular remodeling, highlighting its ability to provide insights into the tumor microenvironment for sunitinib treatment and other anti-angiogenic therapies.

New Carbothioamide and Carboxamide Derivatives of 3-Phenoxybenzoic Acid as Potent VEGFR-2 Inhibitors: Synthesis, Molecular Docking, and Cytotoxicity Assessment

INTRODUCTION/BACKGROUND

Because of the well-established link between angiogenesis and tumor development, the use of antiangiogenic therapeutics, such as those targeting VEGFR-2, presents a promising approach to cancer treatment. In the current study, a set of five hydrazine-1- carbothioamide (compounds 3a-e) and three hydrazine-1-carboxamide derivatives (compounds 4a-c) were successfully synthesized from 3-phenoxybenzoic acid. These compounds were specially created as antiproliferative agents with the goal of targeting cancer cells by inhibiting VEGFR- 2 tyrosine kinase.

MATERIALS AND METHODS

The new derivatives were synthesized by conventional organic methods, and their structure was versified by IR, 1HNMR, 13CNMR, and mass spectroscopy. In silico investigation was carried out to identify the compounds' target, molecular similarity, ADMET, and toxicity profile. The cytotoxic activity of the prepared compounds was evaluated in vitro against three human cancer cell lines (DLD1 colorectal adenocarcinoma, HeLa cervical cancer, and HepG2 hepatocellular carcinoma). The effects of the leading compound on cell cycle progression and apoptosis induction were investigated by flow cytometry, and the specific apoptotic pathway triggered by the treatment was evaluated by RT-PCR and immunoblotting. Finally, the inhibitory activities of the new compounds against VEGFR-2 was measured.

RESULTS

The designed derivatives exhibited comparable binding positions and interactions to the VEGFR-2 binding site to that of sorafenib (a standard VEGFR-2 tyrosine kinase inhibitor), as determined by molecular docking analysis. Compound 4b was the most cytotoxic compound, achieving the lowest IC50 against HeLa cells. Compound 4b, a strong representative of the synthesized series, induced cell cycle arrest at the G2/M phase, increased the proportion of necrotic and apoptotic HeLa cells, and activated caspase 3. The EC50 value of compound 4b against VEGFR-2 kinase activity was comparable to sorafenib's.

CONCLUSION

Overall, the findings suggest that compound 4b has a promising future as a starting point for the development of new anticancer drugs.

Lenvatinib radiofrequency ablation sequential therapy offers survival benefits for patients with unresectable hepatocellular carcinoma at intermediate stage and the liver reserve of Child-Pugh A category: A multicenter study

AIM

This study aims to evaluate the efficacy and safety of lenvatinib radiofrequency ablation (RFA) sequential therapy for certain hepatocellular carcinoma (HCC) patients.

METHODS

One hundred and nineteen patients with unresectable HCC in the intermediate stage with Child-Pugh A were retrospectively recruited in a multicenter setting. Those in the lenvatinib RFA sequential therapy group received lenvatinib initially, followed by RFA and the retreatment with lenvatinib. The study compared overall survival (OS), progression-free survival (PFS), tumor response, and adverse events (AEs) between patients undergoing sequential therapy and lenvatinib monotherapy.

RESULTS

After propensity score matching, 25 patients on sequential therapy and 50 on monotherapy were evaluated. Independent factors influencing OS were identified as sequential therapy, modified albumin-bilirubin (mALBI) grade, and relative dose intensity (%) with hazard ratios (HRs) of 0.381 (95% confidence interval [CI], 0.186-0.782), 2.220 (95% CI, 1.410-3.493), and 0.982 (95% CI, 0.966-0.999), respectively. Stratified analysis based on mALBI grades confirmed the independent influence of treatment strategy across all mALBI grades for OS (HR, 0.376; 95% CI, 0.176-0.804). Furthermore, sequential therapy was identified as an independent factor of PFS (HR, 0.382; 95% CI, 0.215-0.678). Sequential therapy significantly outperformed monotherapy on survival benefits (OS: 38.27 vs. 18.96 months for sequential therapy and monotherapy, respectively, p = 0.004; PFS: 13.80 vs. 5.32 months for sequential therapy and monotherapy, respectively, p < 0.001). Sequential therapy was significantly associated with complete response by modified Response Evaluation Criteria in Solid Tumors (odds ratio, 63.089). Ten of 119 patients experienced grade 3 AEs, with no AE beyond grade 3 observed.

CONCLUSION

Lenvatinib RFA sequential therapy might offer favorable tolerability and potential prognostic improvement compared to lenvatinib monotherapy.

Lenvatinib Plus Ifosfamide and Etoposide in Children and Young Adults With Relapsed Osteosarcoma: A Phase 2 Randomized Clinical Trial

Importance

The combination of ifosfamide and etoposide (IE) is commonly used to treat relapsed or refractory osteosarcoma; however, second-line treatment recommendations vary across guidelines.

Objective

To evaluate whether the addition of lenvatinib to IE (LEN-IE) improves outcomes in children and young adults with relapsed or refractory osteosarcoma.

Design, Setting, and Participants

The OLIE phase II, open-label, randomized clinical trial was conducted globally across Europe, Asia and the Pacific, and North America. From March 22, 2020, through November 11, 2021, the trial enrolled patients aged 2 to 25 years with high-grade osteosarcoma, measurable or evaluable disease per Response Evaluation Criteria in Solid Tumors, version 1.1 (RECIST 1.1), and 1 to 2 prior lines of systemic treatment. The data analyses were performed between March 22, 2020 (first patient in) and June 22, 2022 (data cutoff for the primary analysis), and September 29, 2023 (end of study final database lock).

Interventions

The OLIE trial assessed the efficacy and safety of lenvatinib (14 mg/m2 taken orally once daily) combined with up to 5 cycles of ifosfamide (3000 mg/m2 intravenously) and etoposide (100 mg/m2 intravenously) on days 1 to 3 of each cycle vs IE alone at the same doses. Patients randomized to IE could cross over to receive lenvatinib upon disease progression by independent imaging review.

Main Outcomes and Measures

The primary end point was progression-free survival (PFS) per RECIST 1.1 by independent imaging review. The Kaplan-Meier method was used to estimate the PFS distribution, with a prespecified 1-sided significance threshold of .025 by stratified log-rank test. Secondary end points included PFS rate at 4 months and overall survival. Adverse events were summarized using descriptive statistics.

Results

A total of 81 patients were enrolled (median [IQR] age, 15.0 [12.0-18.0] years; 46 males [56.8%]), with 40 in the LEN-IE arm and 41 in the IE arm. Median PFS was 6.5 months (95% CI, 5.7-8.2 months) for the LEN-IE arm and 5.5 months (95% CI, 2.9-6.5 months) for the IE arm (hazard ratio [HR], 0.54; 95% CI, 0.27-1.08; 1-sided P = .04). The rate of PFS at 4 months was 76.3% (95% CI, 59.3%-86.9%) in the LEN-IE arm and 66.0% (95% CI, 47.7%-79.2%) in the IE arm. Median overall survival was 11.9 months (95% CI, 10.1 months to not estimable) with LEN-IE and 17.4 months (95% CI, 14.2 months to not estimable) with IE (HR, 1.28; 95% CI, 0.60-2.70; 1-sided nominal P = .75). Grade 3 or higher treatment-related adverse events occurred in 35 of 39 patients (89.7%) in the LEN-IE arm and 31 of 39 patients (79.5%) in the IE arm.

Conclusions and Relevance

Although LEN-IE did not meet prespecified statistical significance for improved PFS vs IE, this study demonstrates the importance of international collaboration and randomized clinical trials in patients with relapsed or refractory osteosarcoma and may inform future trial design.

Trial Registration

ClinicalTrials.gov Identifier: NCT04154189.

Efficacy and safety of anlotinib combined with immune checkpoint inhibitors and platinum-containing chemotherapy for later-line advanced non-small cell lung cancer: a retrospective three-arm real-world study using propensity-score matching

Objective

To assess the efficacy and safety of anlotinib combined with immune checkpoint inhibitors (ICIs) in patients with advanced non-small-cell lung cancer (NSCLC).

Methods

Clinical data on patients with advanced NSCLC were collected from June 2019 to October 2022 at Hebei General Hospital, China. The efficacy and safety of anlotinib combined with ICIs and platinum-containing chemotherapy were retrospectively analyzed. The primary endpoint was progression-free survival (PFS). The secondary endpoint was the disease control rate (DCR) and overall survival (OS). Survival curves were created using the Kaplan-Meier method. The efficacy and adverse reactions were evaluated according to the RECIST 1.1 and CTCAE 5.0 standards.

Results

A total of 54 patients were enrolled in this study after propensity score matching (PSM), including 27 men and 17 women, with a median age of 59. A total of 26 patients received anlotinib + ICIs + platinum-containing chemotherapy (AIC), 15 patients received anlotinib + platinum-containing chemotherapy (AC), and 13 patients received ICIs + platinum-containing chemotherapy (IC). The PFS of the AIC group was 7.76 months (95% CI: 3.71-NC). The DCR was 65.38%. The OS endpoint had not been reached, The AIC combination regimen group had a significantly longer PFS than the IC group (mPFS, 7.76 vs. 2.33 months, p=0.012, HR=0.23, 95% CI: 0.06-0.8). There was no significant difference in the DCR between the two groups (65.38% vs. 53.85%, p=0.326). There was a statistically significant difference in PFS between the AC group and the IC group (mPFS, 9.2 vs. 2.33 months, p=0.02, HR=0.14, 95% CI: 0.03-0.65). There was no significant difference in the DCR between the two groups (40% vs. 53.85%, p=0.445). The common adverse reactions of the combination of anti-angiogenic agents, ICIs, and platinum-containing chemotherapy were anemia (34.62%), allergic reactions (19.23%), thrombocytopenia (11.54%), gastrointestinal reactions (15.38%), and hepatobiliary disorders (11.54%). Most of them were manageable.

Conclusions

Anlotinib combined with immune checkpoint inhibitors and platinum-containing chemotherapy regimens offers a good survival benefit for patients with advanced non-small-cell lung cancer who fail to respond to standard therapy. When both efficacy and safety are considered, a combination of anti-angiogenic agents, ICIs, and platinum-containing chemotherapy can be used as a choice for the treatment of advanced NSCLC.

Neoadjuvant Chemotherapy With the Angiogenesis Inhibitor Bevacizumab for Locally Advanced Cervical Cancer

BACKGROUND/AIM

We hypothesized that adding bevacizumab to platinum-based neoadjuvant chemotherapy - whose efficacy for patients with recurrent or metastatic cervical cancer has already been proven - could optimize the therapy regimen, leading to improved response rates and survival outcomes.

PATIENTS AND METHODS

Forty patients with histologically confirmed cervical cancer with FIGO stage IB3-IVA who received platinum-based neoadjuvant treatment between March 2008 and January 2019 in the Department of Obstetrics and Gynecology of University Hospital Cologne were analyzed. Twenty patients were treated with additional bevacizumab. The comparative cohort consisted of 18 patients treated with neoadjuvant chemotherapy alone. The response rates and clinical outcomes, including progression-free survival and overall survival, were evaluated.

RESULTS

Neoadjuvant chemotherapy combined with bevacizumab significantly improved the response rate (p=0.046). The survival analysis showed that patients treated without bevacizumab had better progression-free survival up to FIGO stage IVA than patients treated with bevacizumab. However, overall survival was similar for both cohorts. For patients with advanced tumor stage, including FIGO IVB, progression-free survival and overall survival improved with the addition of bevacizumab. Pathological complete remission was a statistically significant prognostic factor for progression-free survival (p=0.039) but did not significantly affect overall survival (p=0.098).

CONCLUSION

While bevacizumab did not demonstrate a significant improvement in overall survival rates, it was associated with a notable reduction in tumor size and showed a trend towards improved clinical response rates. These findings suggest that bevacizumab may have potential in optimizing the neoadjuvant treatment approach.

Immunomodulation by endothelial cells: prospects for cancer therapy

Growing evidence highlights the importance of tumor endothelial cells (TECs) in the tumor microenvironment (TME) for promoting tumor growth and evading immune responses. Immunomodulatory endothelial cells (IMECs) represent a distinct plastic phenotype of ECs that exerts the ability to modulate immunity in health and disease. This review discusses our current understanding of IMECs in cancer biology, scrutinizing insights from single-cell reports to compare their characteristics and function dynamics across diverse tumor types, conditions, and species. We investigate possible implications of exploiting IMECs in the context of cancer treatment, particularly examining their influence on the efficacy of existing therapies and the potential to leverage them as targets in optimizing immunotherapeutic strategies.

Modified C-type natriuretic peptide normalizes tumor vasculature, reinvigorates antitumor immunity, and improves solid tumor therapies

Deficit of oxygen and nutrients in the tumor microenvironment (TME) triggers abnormal angiogenesis that produces dysfunctional and leaky blood vessels, which fail to adequately perfuse tumor tissues. Resulting hypoxia, exacerbation of metabolic disturbances, and generation of an immunosuppressive TME undermine the efficacy of anticancer therapies. Use of carefully scheduled angiogenesis inhibitors has been suggested to overcome these problems and normalize the TME. Here, we propose an alternative agonist-based normalization approach using a derivative of the C-type natriuretic peptide (dCNP). Multiple gene expression signatures in tumor tissues were affected in mice treated with dCNP. In several mouse orthotopic and subcutaneous solid tumor models including colon and pancreatic adenocarcinomas, this well-tolerated agent stimulated formation of highly functional tumor blood vessels to reduce hypoxia. Administration of dCNP also inhibited stromagenesis and remodeling of the extracellular matrix and decreased tumor interstitial fluid pressure. In addition, treatment with dCNP reinvigorated the antitumor immune responses. Administration of dCNP decelerated growth of primary mouse tumors and suppressed their metastases. Moreover, inclusion of dCNP into the chemo-, radio-, or immune-therapeutic regimens increased their efficacy against solid tumors in immunocompetent mice. These results demonstrate the proof of principle for using vasculature normalizing agonists to improve therapies against solid tumors and characterize dCNP as the first in class among such agents.

Integration of Clinical Trial Spatial Multiomics Analysis and Virtual Clinical Trials Enables Immunotherapy Response Prediction and Biomarker Discovery

Due to the lack of treatment options, there remains a need to advance new therapeutics in hepatocellular carcinoma (HCC). The traditional approach moves from initial molecular discovery through animal models to human trials to advance novel systemic therapies that improve treatment outcomes for patients with cancer. Computational methods that simulate tumors mathematically to describe cellular and molecular interactions are emerging as promising tools to simulate the impact of therapy entirely in silico, potentially greatly accelerating delivery of new therapeutics to patients. To facilitate the design of dosing regimens and identification of potential biomarkers for immunotherapy, we developed a new computational model to track tumor progression at the organ scale while capturing the spatial heterogeneity of the tumor in HCC. This computational model of spatial quantitative systems pharmacology was designed to simulate the effects of combination immunotherapy. The model was initiated using literature-derived parameter values and fitted to the specifics of HCC. Model validation was done through comparison with spatial multiomics data from a neoadjuvant HCC clinical trial combining anti-PD1 immunotherapy and a multitargeted tyrosine kinase inhibitor cabozantinib. Validation using spatial proteomics data from imaging mass cytometry demonstrated that closer proximity between CD8 T cells and macrophages correlated with nonresponse. We also compared the model output with Visium spatial transcriptomics profiling of samples from posttreatment tumor resections in the clinical trial and from another independent study of anti-PD1 monotherapy. Spatial transcriptomics data confirmed simulation results, suggesting the importance of spatial patterns of tumor vasculature and TGFβ in tumor and immune cell interactions. Our findings demonstrate that incorporating mathematical modeling and computer simulations with high-throughput spatial multiomics data provides a novel approach for patient outcome prediction and biomarker discovery. Significance: Incorporating mathematical modeling and computer simulations with high-throughput spatial multiomics data provides an effective approach for patient outcome prediction and biomarker discovery.

Dendrimer-mediated targeting of angiogenic biomarkers: therapeutic intervention against cancer

INTRODUCTION

Development of novel vascular networks is a fundamental requirement for tumor growth and progression. In the last decade, biomarkers and underlying molecular pathways of angiogenesis have been intensely investigated to disrupt the initiation and progression of tumor angiogenesis. However, the clinical applications of anti-angiogenic agents are constrained due to toxic side effects, acquired drug resistance, and unavailability of validated biomarkers.

AREA COVERED

This review discusses the development of dendrimeric nanocarriers that could be a promising domain to explore for the eradication of current challenges associated with angiogenesis-based cancer therapy. Novel drug-delivery approaches with subtle readouts and better understanding of molecular mechanisms have revealed that dendrimers comprise innate anti-angiogenic activity and incorporation of anti-angiogenic agents or gene-silencing RNA could lead to synergistic anti-angiogenic and anticancer effects with reduced side effects.

EXPERT OPINION

Dendrimer-mediated targeting of angiogenic biomarkers has efficiently led to the vascular normalization, and rational linking of dendrimers with anti-angiogenic agent or siRNA or both might be a potential area to eradicate the current challenges of angiogenesis-based cancer therapy. However, drawbacks associated with the dendrimers-mediated targeting of angiogenic biomarkers, such as poor stability or small expression of these biomarkers on the normal cells, limit their application at market scale.

An integrated omics approach highlights how epigenetic events can explain and predict response to neoadjuvant chemotherapy and bevacizumab in breast cancer

Treatment with the anti-angiogenic drug bevacizumab in addition to chemotherapy has shown efficacy for breast cancer in some clinical trials, but better biomarkers are needed to optimally select patients for treatment. Here, we present an omics approach where DNA methylation profiles are integrated with gene expression and results from proteomic data in breast cancer patients to predict response to therapy and pinpoint response-related epigenetic events. Fresh-frozen tumor biopsies taken before, during, and after treatment from human epidermal growth factor receptor 2 negative non-metastatic patients receiving neoadjuvant chemotherapy with or without bevacizumab were subjected to molecular profiling. Here, we report that DNA methylation at enhancer CpGs related to cell cycle regulation can predict response to chemotherapy and bevacizumab for the estrogen receptor positive subset of patients (AUC = 0.874), and we validated this observation in an independent patient cohort with a similar treatment regimen (AUC = 0.762). Combining the DNA methylation scores with the scores from a previously published protein signature resulted in a slight increase in the prediction performance (AUC = 0.784). We also show that tumors receiving the combination treatment underwent more extensive epigenetic alterations. Finally, we performed an integrative expression-methylation quantitative trait loci analysis on alterations in DNA methylation and gene expression levels, showing that the epigenetic alterations that occur during treatment are different between responders and non-responders and that these differences may be explained by the proliferation-epithelial-to-mesenchymal transition axis through the activity of grainyhead like transcription factor 2. Using tumor purity computed from copy number data, we developed a method for estimating cancer cell-specific methylation to confirm that the association to response reflects DNA methylation in cancer cells. Taken together, these results support the potential for clinical benefit of the addition of bevacizumab to chemotherapy when administered to the correct patients.

Towards equitable AI in oncology

Artificial intelligence (AI) stands at the threshold of revolutionizing clinical oncology, with considerable potential to improve early cancer detection and risk assessment, and to enable more accurate personalized treatment recommendations. However, a notable imbalance exists in the distribution of the benefits of AI, which disproportionately favour those living in specific geographical locations and in specific populations. In this Perspective, we discuss the need to foster the development of equitable AI tools that are both accurate in and accessible to a diverse range of patient populations, including those in low-income to middle-income countries. We also discuss some of the challenges and potential solutions in attaining equitable AI, including addressing the historically limited representation of diverse populations in existing clinical datasets and the use of inadequate clinical validation methods. Additionally, we focus on extant sources of inequity including the type of model approach (such as deep learning, and feature engineering-based methods), the implications of dataset curation strategies, the need for rigorous validation across a variety of populations and settings, and the risk of introducing contextual bias that comes with developing tools predominantly in high-income countries.

Epstein-Barr virus causes vascular abnormalities in epithelial malignancies through upregulating ANXA3-HIF-1α-VEGF pathway

Angiogenesis is one of the characteristics of malignant tumors, and persistent generation of abnormal tumor blood vessels is an important factor contributing to tumor treatment resistance. Epstein-Barr virus (EBV) is a highly prevalent DNA oncogenic virus that is associated with the development of various epithelial malignancies. However, the relationship between EBV infection and tumor vascular abnormalities as well as its underlying mechanisms is still unclear. In this study, we found that compared to EBV-uninfected tumors, EBV-infected tumors were more angiogenic, but the neovascularization was mostly immature vessels without pericyte attachment in both clinical patient tumor samples and mouse xenograft models; These immature vessels exhibited aberrant functionality, characterized by poor blood perfusion and increased vascular permeability. The vascular abnormalities caused by EBV infection exacerbated tumor hypoxia and was responsible for accelerated tumor growth. Mechanistically, EBV infection upregulated ANXA3-HIF-1α-VEGF pathway. Silencing the ANXA3 gene or neutralizing ANXA3 with an antibody can diminish vascular abnormalities, thereby increasing immune cell infiltration and alleviating treatment resistance. Finally, a new therapy combining ANXA3 blockade and NK cell + PD1 antibody significantly inhibited the growth of EBV-infected xenografts in mice. In conclusion, our study identified a previously unrecognized role for EBV infection in tumor vascular abnormalities and revealed its underlying mechanism that upregulated the ANXA3-HIF-1α-VEGF pathway. ANXA3 is a potential therapeutic target for EBV-infected tumors and ANXA3 blockade to improve vascular conditions, in combination with NK cell + PD1 antibody therapy, holds promise as an effective treatment strategy for EBV-associated epithelial malignancies.

Vascular regional analysis unveils differential responses to anti-angiogenic therapy in pancreatic xenografts through macroscopic photoacoustic imaging

Pancreatic cancer (PC) is a highly lethal malignancy and the third leading cause of cancer deaths in the U.S. Despite major innovations in imaging technologies, there are limited surrogate radiographic indicators to aid in therapy planning and monitoring. Amongst the various imaging techniques Ultrasound-guided photoacoustic imaging (US-PAI) is a promising modality based on endogenous blood (hemoglobin) and blood oxygen saturation (StO 2 ) contrast to monitor response to anti-angiogenic therapies. Adaptation of US-PAI to the clinical realm requires macroscopic configurations for adequate depth visualization, illuminating the need for surrogate radiographic markers, including the tumoral microvessel density (MVD). In this work, subcutaneous xenografts with PC cell lines AsPC-1 and MIA-PaCa-2 were used to investigate the effects of receptor tyrosine kinase inhibitor (sunitinib) treatment on MVD and StO 2 . Through histological correlation, we have shown that regions of high and low vascular density (HVD and LVD) can be identified through frequency domain filtering of macroscopic PA images which could not be garnered from purely global analysis. We utilized vascular regional analysis (VRA) of treatment-induced StO 2 and total hemoglobin (HbT) changes. VRA as a tool to monitor treatment response allowed us to identify potential timepoints of vascular remodeling, highlighting its ability to provide insights into the TME not only for sunitinib treatment but also other anti-angiogenic therapies.

Biophysical and biochemical aspects of immune cell-tumor microenvironment interactions

The tumor microenvironment (TME), composed of and influenced by a heterogeneous set of cancer cells and an extracellular matrix, plays a crucial role in cancer progression. The biophysical aspects of the TME (namely, its architecture and mechanics) regulate interactions and spatial distributions of cancer cells and immune cells. In this review, we discuss the factors of the TME-notably, the extracellular matrix, as well as tumor and stromal cells-that contribute to a pro-tumor, immunosuppressive response. We then discuss the ways in which cells of the innate and adaptive immune systems respond to tumors from both biochemical and biophysical perspectives, with increased focus on CD8+ and CD4+ T cells. Building upon this information, we turn to immune-based antitumor interventions-specifically, recent biophysical breakthroughs aimed at improving CAR-T cell therapy.

Fas Ligand enhances vessel maturation and inhibits vascular leakage associated with age-related macular degeneration

Neovascular age-related macular degeneration (AMD), results from choroidal neovascularization (CNV), retinal edema and loss of photoreceptors. Previous studies suggested that Fas Ligand (FasL) on retinal pigment epithelial cells inhibited CNV by inducing apoptosis of infiltrating Fas+ vascular endothelial cells. However, induction of apoptosis depends on membrane-bound (mFasL) while the FasL cleavage product (sFasL) is neuroprotective. To better understand how FasL regulates the development of CNV, we used a mouse model of laser CNV to evaluate the development of CNV in mice with a FasL cleavage site mutation (ΔCS) and can only express the membrane-bound form of FasL. There was no significant difference in CNV size and area of vascular leakage in homozygous FasLΔCS/ΔCS mice when compared to wild type mice. Unexpectedly, heterozygous FasLΔCS/WT mice developed significantly less vascular leakage and showed accelerated neovessel maturation. However, CNV was not prevented in heterozygous FasLΔCS/WT mice if the Fas receptor was deleted in myeloid cells (FasLΔCS/+ Fasflox/flox CreLysM). Thus, FasL-mediated CNV inhibition depends on the extent of FasL cleavage, and on FasL engagement of Fas+ myeloid cells. Moreover, accelerated neovessel maturation prevents vascular leakage in AMD.

PDGFRβ-Antagonistic Affibody-Mediated Tumor-Targeted Tumor Necrosis Factor-Alpha for Enhanced Radiotherapy in Lung Cancer

The morbidity and mortality of lung cancer are still the highest among all malignant tumors. Radiotherapy plays an important role in clinical treatment of lung cancer. However, the effect of radiotherapy is not ideal due to the radiation resistance of tumor tissues. Abnormalities in tumor vascular structure and function affect blood perfusion, and oxygen transport is impeded, making tumor microenvironment hypoxic. Tumor hypoxia is the major cause of radiotherapy resistance. By promoting tumor vessel normalization and enhancing vascular transport function, tumor hypoxia can be relieved to reduce radiotherapy resistance and increase tumor radiotherapy sensitivity. In our previous study, a pericytes-targeted tumor necrosis factor alpha (named Z-TNFα) was first constructed and produced by genetically fusing the platelet-derived growth factor receptor β (PDGFRβ)-antagonistic affibody (ZPDGFRβ) to the TNFα, and the Z-TNFα induced normalization of tumor vessels and improved the delivery of doxorubicin, enhancing tumor chemotherapy. In this study, the tumor vessel normalization effect of Z-TNFα in lung cancer was further clarified. Moreover, the tumor hypoxia improvement and radiosensitizing effect of Z-TNFα were emphatically explored in vivo. Inspiringly, Z-TNFα specifically accumulated in Lewis lung carcinoma (LLC) tumor graft and relieved tumor hypoxia as well as inhibited HIF-1α expression. As expected, Z-TNFα significantly increased the effect of radiotherapy in mice bearing LLC tumor graft. In conclusion, these results demonstrated that Z-TNFα is also a promising radiosensitizer for lung cancer radiotherapy.

Whole-Brain Radiotherapy Alone vs Preceded by Bevacizumab, Etoposide, and Cisplatin for Untreated Brain Metastases From Breast Cancer: A Randomized Clinical Trial

Importance

The incidence of brain metastasis is increasing in patients with metastatic breast cancer. Treatments to extend the control of brain metastasis are urgently required.

Objective

To investigate whether the addition of an induction treatment of bevacizumab, etoposide, and cisplatin (BEEP) improves brain-specific progression-free survival (PFS) after whole-brain radiotherapy (WBRT).

Design, Setting, and Participants

This open-label, randomized, multicenter clinical trial assessed patients with brain metastases from breast cancer (BMBC) in Taiwan from September 9, 2014, to December 24, 2018, with survival follow-up until December 31, 2021. Key inclusion criteria included metastatic brain tumors not suitable for focal treatment, WBRT naivety, age 20 to 75 years, and at least 1 measurable brain metastatic lesion. The primary end point was brain-specific PFS, with an expected hazard ratio of 0.60, a 2-sided α ≤ .20, and power of 0.8.

Interventions

Eligible patients were randomly assigned at a ratio of 2:1 to the experimental arm, which involved 3 cycles of BEEP followed by WBRT, or the control arm, which involved WBRT alone.

Main Outcomes and Measures

The primary end point was the determination of brain-specific PFS by local investigators according to the Response Evaluation Criteria in Solid Tumors, version 1.1, the initiation of other brain-directed treatment after WBRT, or death. Other key end points included brain-specific objective response rate after 8 weeks of BEEP treatment or WBRT and 8-month brain-specific PFS rate, PFS, and overall survival.

Results

A total of 118 patients with BMBC were randomized, with the intention-to-treat cohort comprising 112 patients. The median age was 56 years (range, 34-71 years), and 61 patients (54.5%) had ERBB2 (formerly HER2 or HER2/neu)-positive disease. The median (range) brain-specific PFS was 8.1 (0.3-29.5) vs 6.5 (0.9-25.5) months in the experimental and control arms, respectively (hazard ratio, 0.71; 95% CI, 0.44-1.13; P = .15; significant at predefined α ≤ .20). The brain-specific objective response rate at 2 months was not significantly different (BEEP treatment vs WBRT, 41.9% vs 52.6%), but the 8-month brain-specific PFS rate was significantly higher in the experimental group (48.7% vs 26.3%; P = .03). Adverse events were generally manageable with prophylactic granulocyte colony-stimulating factor treatment.

Conclusions and Relevance

The findings show that induction BEEP before WBRT may improve the control of BMBC compared with using upfront WBRT, which could address an unmet need for an effective systemic treatment for intractable brain and extracranial metastases from metastatic breast cancer.

Trial Registration

ClinicalTrials.gov Identifier: NCT02185352.

Negative impact of ratio of the microvascular area to tumor area on the response to EGFR-TKI in non-small cell lung cancer with an EGFR mutation

Background

The clinical impact of tumor microvessels on the efficacy of epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) in EGFR mutation-positive non-small cell lung cancer (NSCLC) is unclear. Thus, the aim of this study was to investigate whether a tumor microenvironment, abundant in microvessels, affects EGFR-TKI efficacy in patients with NSCLC and EGFR mutations.

Methods

We retrospectively studied the data of 40 post-operative patients with recurrent NSCLC and EGFR mutations who received EGFR-TKIs as a first-line treatment at Kumamoto University Hospital from January 2010 to February 2021. Tumor sections were retrieved from the tissue registry and analyzed for CD34-positive microvessels using immunohistochemical techniques. The ratio of microvascular area to tumor area (RMV), which is the CD34-positive microvascular area compared to the total tumor area, was measured using StrataQuest. The predictive value of RMV on treatment outcome, assessed via progression-free survival (PFS), was evaluated using a multivariate Cox proportional hazard model.

Results

The median PFS in the high RMV group (≥0.058) was significantly shorter than that in the low RMV group [<0.058; 296 days, 95% confidence interval (CI): 217-374 vs. 918 days, 95% CI: 279-1,556, P=0.002]. Multivariate analysis revealed that high RMV was an independent negative predictor of PFS (hazard ratio, 3.21; 95% CI: 1.18-8.76, P=0.022).

Conclusions

High RMV may critically affect EGFR-TKI resistance in patients with NSCLC and EGFR mutations.

Adjuvant Novel Nanocarrier-Based Targeted Therapy for Lung Cancer

Lung cancer has the lowest survival rate due to its late-stage diagnosis, poor prognosis, and intra-tumoral heterogeneity. These factors decrease the effectiveness of treatment. They release chemokines and cytokines from the tumor microenvironment (TME). To improve the effectiveness of treatment, researchers emphasize personalized adjuvant therapies along with conventional ones. Targeted chemotherapeutic drug delivery systems and specific pathway-blocking agents using nanocarriers are a few of them. This study explored the nanocarrier roles and strategies to improve the treatment profile's effectiveness by striving for TME. A biofunctionalized nanocarrier stimulates biosystem interaction, cellular uptake, immune system escape, and vascular changes for penetration into the TME. Inorganic metal compounds scavenge reactive oxygen species (ROS) through their photothermal effect. Stroma, hypoxia, pH, and immunity-modulating agents conjugated or modified nanocarriers co-administered with pathway-blocking or condition-modulating agents can regulate extracellular matrix (ECM), Cancer-associated fibroblasts (CAF),Tyro3, Axl, and Mertk receptors (TAM) regulation, regulatory T-cell (Treg) inhibition, and myeloid-derived suppressor cells (MDSC) inhibition. Again, biomimetic conjugation or the surface modification of nanocarriers using ligands can enhance active targeting efficacy by bypassing the TME. A carrier system with biofunctionalized inorganic metal compounds and organic compound complex-loaded drugs is convenient for NSCLC-targeted therapy.

Comparative analysis of the effect of hypoxia in two different tumor cell models shows the differential involvement of PTEN control of proangiogenic pathways

Hypoxia, low, non-physiological oxygen tension is a key regulator of tumor microenvironment, determining the pathological tumor vascularization. Alleviation of hypoxia through vessel normalization may be a promising therapeutic approach. We aimed to assess the role of low oxygen tension in PTEN-related pathways and proangiogenic response, in vitro, in two different tumor cell lines, focusing on potential therapeutic targets for tumor vessel normalization. Downregulation of PTEN in hypoxia mediates the activation of distinct mechanisms: cytoplasmic pAKT activation in melanoma and pMDM2 modulation in kidney cancer. We show that hypoxia-induced proangiogenic potential was stronger in Renca cells than B16 F10-confirmed by a distinct secretory potential and different ability to affect endothelial cells functions. Therefore, the impact of hypoxia on PTEN-mediated regulation may determine the therapeutic targets and effectiveness of vessel normalization and intrinsic characteristics of cancer cell have to be taken into account when designing treatment.

Pattern recognition of microcirculation with super-resolution ultrasound imaging provides markers for early tumor response to anti-angiogenic therapy

Rationale: Cancer treatment outcome is traditionally evaluated by tumor volume change in clinics, while tumor microvascular heterogeneity reflecting tumor response has not been fully explored due to technical limitations. Methods: We introduce a new paradigm in super-resolution ultrasound imaging, termed pattern recognition of microcirculation (PARM), which identifies both hemodynamic and morphological patterns of tumor microcirculation hidden in spatio-temporal space trajectories of microbubbles. Results: PARM demonstrates the ability to distinguish different local blood flow velocities separated by a distance of 24 μm. Compared with traditional vascular parameters, PARM-derived heterogeneity parameters prove to be more sensitive to microvascular changes following anti-angiogenic therapy. Particularly, PARM-identified "sentinel" microvasculature, exhibiting evident structural changes as early as 24 hours after treatment initiation, correlates significantly with subsequent tumor volume changes (|r| > 0.9, P < 0.05). This provides prognostic insight into tumor response much earlier than clinical criteria. Conclusions: The ability of PARM to noninvasively quantify tumor vascular heterogeneity at the microvascular level may shed new light on early-stage assessment of cancer therapy.

VEGF-C-expressing TAMs rewire the metastatic fate of breast cancer cells

The expression of pro-lymphangiogenic VEGF-C in primary tumors is associated with sentinel lymph node metastasis in most solid cancer types. However, the impact of VEGF-C on distant organ metastasis remains unclear. Perivascular tumor-associated macrophages (TAMs) play a crucial role in guiding hematogenous spread of cancer cells by establishing metastatic pathways within the tumor microenvironment. This process supports breast cancer cell intravasation and metastatic dissemination. We show here that VEGF-C-expressing TAMs reduce the dissemination of mammary cancer cells to the lungs while concurrently increasing lymph node metastasis. These TAMs express podoplanin and interact with normalized tumor blood vessels expressing VEGFR3. Moreover, clinical data suggest inverse association between VEGF-C-expressing TAMs and breast cancer malignancy. Thus, our study elucidates the paradoxical role of VEGF-C-expressing TAMs in redirecting cancer cells to preferentially disseminate to lymph nodes rather than to lungs, partially achieved by normalizing tumor blood vessels and promoting lymphangiogenesis.

Charting a killer course to the solid tumor: strategies to recruit and activate NK cells in the tumor microenvironment

The ability to expand and activate natural Killer (NK) cells ex vivo has dramatically changed the landscape in the development of novel adoptive cell therapies for treating cancer over the last decade. NK cells have become a key player for cancer immunotherapy due to their innate ability to kill malignant cells while not harming healthy cells, allowing their potential use as an "off-the-shelf" product. Furthermore, recent advancements in NK cell genetic engineering methods have enabled the efficient generation of chimeric antigen receptor (CAR)-expressing NK cells that can exert both CAR-dependent and antigen-independent killing. Clinically, CAR-NK cells have shown promising efficacy and safety for treating CD19-expressing hematologic malignancies. While the number of pre-clinical studies using CAR-NK cells continues to expand, it is evident that solid tumors pose a unique challenge to NK cell-based adoptive cell therapies. Major barriers for efficacy include low NK cell trafficking and infiltration into solid tumor sites, low persistence, and immunosuppression by the harsh solid tumor microenvironment (TME). In this review we discuss the barriers posed by the solid tumor that prevent immune cell trafficking and NK cell effector functions. We then discuss promising strategies to enhance NK cell infiltration into solid tumor sites and activation within the TME. This includes NK cell-intrinsic and -extrinsic mechanisms such as NK cell engineering to resist TME-mediated inhibition and use of tumor-targeted agents such as oncolytic viruses expressing chemoattracting and activating payloads. We then discuss opportunities and challenges for using combination therapies to extend NK cell therapies for the treatment of solid tumors.

Laser ablation-inductively coupled plasma-mass spectrometry analysis reveals differences in chemotherapeutic drug distribution in surgically resected pleural mesothelioma

AIMS

Pleural mesothelioma (PM) is a highly aggressive thoracic tumour with poor prognosis. Although reduced tissue drug accumulation is one of the key features of platinum (Pt) resistance, little is known about Pt distribution in human PM.

METHODS

We assessed Pt levels of blood samples and surgically resected specimens from 25 PM patients who had received neoadjuvant Pt-based chemotherapy (CHT). Pt levels and tissue distributions were measured by laser ablation-inductively coupled plasma-mass spectrometry and correlated with clinicopathological features.

RESULTS

In surgically resected PM specimens, mean Pt levels of nontumourous (fibrotic) areas were significantly higher (vs tumourous regions, P = 0.0031). No major heterogeneity of Pt distribution was seen within the tumourous areas. Pt levels correlated neither with the microvessel area nor with apoptosis rate in the tumourous or nontumourous regions. A significant positive correlation was found between serum and both full tissue section and tumourous area mean Pt levels (r = 0.532, P = 0.006, 95% confidence interval [95% CI] 0.161-0.771 and r = 0.415, P = 0.039, 95% CI 0.011-0.702, respectively). Furthermore, a significant negative correlation was detected between serum Pt concentrations and elapsed time from the last cycle of CHT (r = -0.474, P = 0.017, 95% CI -0.738--0.084). Serum Pt levels correlated negatively with overall survival (OS) (P = 0.029).

CONCLUSIONS

There are major differences in drug distribution between tumourous and nontumourous areas of PM specimens. Serum Pt levels significantly correlate with full section and tumourous area average Pt levels, elapsed time from the last CHT cycle, and OS. Further studies investigating clinicopathological factors that modulate tissue Pt concentration and distribution are warranted.

Surface Functionalization of Gold Nanoparticles for Targeting the Tumor Microenvironment to Improve Antitumor Efficiency

Gold nanoparticles (AuNPs) have undergone significant research for their use in the treatment of cancer. Numerous researchers have established their potent antitumor properties, which have greatly impacted the treatment of cancer. AuNPs have been used in four primary anticancer treatment modalities, namely radiation, photothermal therapy, photodynamic therapy, and chemotherapy. However, the ability of AuNPs to destroy cancer is lacking and can even harm healthy cells without the right direction to transport them to the tumor microenvironment. Consequently, a suitable targeting technique is needed. Based on the distinct features of the human tumor microenvironment, this review discusses four different targeting strategies that target the four key features of the tumor microenvironment, including abnormal vasculature, overexpression of specific receptors, an acidic microenvironment, and a hypoxic microenvironment, to direct surface-functionalized AuNPs to the tumor microenvironment and increase antitumor efficacies. In addition, some current completed or ongoing clinical trials of AuNPs will also be discussed below to further reinforce the concept of using AuNPs in anticancer therapy.

Low molecular weight heparin synergistically enhances the efficacy of adoptive and anti-PD-1-based immunotherapy by increasing lymphocyte infiltration in colorectal cancer

BACKGROUND

Immunotherapy, including adoptive cell therapy (ACT) and immune checkpoint inhibitors (ICIs), has a limited effect in most patients with colorectal cancer (CRC), and the efficacy is further limited in patients with liver metastasis. Lack of antitumor lymphocyte infiltration could be a major cause, and there remains an urgent need for more potent and safer therapies for CRC.

METHODS

In this study, the antitumoral synergism of low molecular weight heparin (LMWH) combined with immunotherapy in the microsatellite stable (MSS) highly aggressive murine model of CRC was fully evaluated.

RESULTS

Dual LMWH and ACT objectively mediated the stagnation of tumor growth and inhibition of liver metastasis, neither LMWH nor ACT alone had any antitumoral activity on them. The combination of LMWH and ACT obviously increased the infiltration of intratumor CD8+ T cells, as revealed by multiplex immunohistochemistry, purified CD8+ T-cell transfer assay, and IVIM in vivo imaging. Mechanistically, evaluation of changes in the tumor microenvironment revealed that LMWH improved tumor vascular normalization and facilitated the trafficking of activated CD8+ T cells into tumors. Similarly, LMWH combined with anti-programmed cell death protein 1 (PD-1) therapy provided superior antitumor activity as compared with the single PD-1 blockade in murine CT26 tumor models.

CONCLUSIONS

LMWH could enhance ACT and ICIs-based immunotherapy by increasing lymphocyte infiltration into tumors, especially cytotoxic CD8+ T cells. These results indicate that combining LMWH with an immunotherapy strategy presents a promising and safe approach for CRC treatment, especially in MSS tumors.

Induced Vascular Normalization-Can One Force Tumors to Surrender to a Better Microenvironment?

Immunotherapy has changed the way many cancers are being treated. Researchers in the field of immunotherapy and tumor immunology are investigating similar questions: How can the positive benefits achieved with immunotherapies be enhanced? Can this be achieved through combinations with other agents and if so, which ones? In our view, there is an urgent need to improve immunotherapy to make further gains in the overall survival for those patients that should benefit from immunotherapy. While numerous different approaches are being considered, our team believes that drug delivery methods along with appropriately selected small-molecule drugs and drug candidates could help reach the goal of doubling the overall survival rate that is seen in some patients that are given immunotherapeutics. This review article is prepared to address how immunotherapies should be combined with a second treatment using an approach that could realize therapeutic gains 10 years from now. For context, an overview of immunotherapy and cancer angiogenesis is provided. The major targets in angiogenesis that have modulatory effects on the tumor microenvironment and immune cells are highlighted. A combination approach that, for us, has the greatest potential for success involves treatments that will normalize the tumor's blood vessel structure and alter the immune microenvironment to support the action of immunotherapeutics. So, this is reviewed as well. Our focus is to provide an insight into some strategies that will engender vascular normalization that may be better than previously described approaches. The potential for drug delivery systems to promote tumor blood vessel normalization is considered.

The Role of Targeted Therapy in the Multi-Disciplinary Approach to Colorectal Liver Metastasis

Colorectal cancer (CRC) is the second most common cause of cancer-related mortality in the United States. Among newly diagnosed patients with CRC, 20% will present with metastatic disease and another 25% will develop metastases. The surgical resection of the primary tumor and metastatic disease sites confers the best chance at long-term survival. Unfortunately, many patients will recur after resection or present with unresectable disease. As such, metastatic CRC is commonly treated with a combination of surgery, systemic therapy, and/or liver-directed therapies. Despite best efforts, 5-year survival for unresectable metastatic CRC is only about 20%. CRC is a heterogeneous disease and the underlying genetic differences inform behavior, treatment strategy, and prognosis. Given the limitations of cytotoxic chemotherapy and the growing role of molecular profiling, research has focused on identifying and developing targeted therapies. We herein review how genetic profiling informs prognosis, crucial cell-signaling pathways that play a role in CRC carcinogenesis, and currently approved targeted therapies for metastatic CRC.

Understanding tumour endothelial cell heterogeneity and function from single-cell omics

Anti-angiogenic therapies (AATs) are used to treat different types of cancers. However, their success is limited owing to insufficient efficacy and resistance. Recently, single-cell omics studies of tumour endothelial cells (TECs) have provided new mechanistic insight. Here, we overview the heterogeneity of human TECs of all tumour types studied to date, at the single-cell level. Notably, most human tumour types contain varying numbers but only a small population of angiogenic TECs, the presumed targets of AATs, possibly contributing to the limited efficacy of and resistance to AATs. In general, TECs are heterogeneous within and across all tumour types, but comparing TEC phenotypes across tumours is currently challenging, owing to the lack of a uniform nomenclature for endothelial cells and consistent single-cell analysis protocols, urgently raising the need for a more consistent approach. Nonetheless, across most tumour types, universal TEC markers (ACKR1, PLVAP and IGFBP3) can be identified. Besides angiogenesis, biological processes such as immunomodulation and extracellular matrix organization are among the most commonly predicted enriched signatures of TECs across different tumour types. Although angiogenesis and extracellular matrix targets have been considered for AAT (without the hoped success), the immunomodulatory properties of TECs have not been fully considered as a novel anticancer therapeutic approach. Therefore, we also discuss progress, limitations, solutions and novel targets for AAT development.

α-SMA positive vascular mural cells suppress cyst formation in hemangioblastoma

Approximately 60% of hemangioblastomas (HBs) have peritumoral cysts adjacent to the tumor, which can cause neurological deficits due to the mass effect, and the management of cyst formation is a clinical challenge. Vascular mural cells surrounding endothelial cells consist of vascular smooth muscle cells (vSMCs) and pericytes, which are essential elements that support blood vessels and regulate permeability. This study investigated the involvement of mural cells in cyst formation. We analyzed the expression of α-smooth muscle actin (α-SMA), platelet-derived growth factor receptor-beta (PDGFRB), and CD31 in 39 consecutive human cerebellar HBs, 20 of cystic and 19 of solid type. Solid type HBs showed stronger diffuse expression of α-SMA in precapillary arterioles and capillaries within the tumor than cystic type HBs (p = 0.001), whereas there was no difference in PDGFRB and CD31 expression. Detailed observation with immunofluorescence demonstrated that α-SMA was expressed in vascular mural cells surrounding capillaries in the solid rather than in the cystic type. Multivariate analysis including various clinical and pathological factors showed that lower α-SMA expression was significantly correlated with cyst formation (p < 0.001). Our data suggested that vascular mural cells from precapillary arterioles to capillaries expressing α-SMA may be pericytes and play a crucial role in HB cystogenesis.

Amine-weighted chemical exchange saturation transfer magnetic resonance imaging in brain tumors

Amine-weighted chemical exchange saturation transfer (CEST) magnetic resonance imaging (MRI) is particularly valuable as an amine- and pH-sensitive imaging technique in brain tumors, targeting the intrinsically high concentration of amino acids with exchangeable amine protons and reduced extracellular pH in brain tumors. Amine-weighted CEST MRI contrast is dependent on the glioma genotype, likely related to differences in degree of malignancy and metabolic behavior. Amine-weighted CEST MRI may provide complementary value to anatomic imaging in conventional and exploratory therapies in brain tumors, including chemoradiation, antiangiogenic therapies, and immunotherapies. Continual improvement and clinical testing of amine-weighted CEST MRI has the potential to greatly impact patients with brain tumors by understanding vulnerabilities in the tumor microenvironment that may be therapeutically exploited.

The Effect of Stem Cells and Vascular Endothelial Growth Factor on Cancer Angiogenesis

The formation of new vessels from pre-existing vessels is known as angiogenesis. The process is controlled by stimuli and inhibitors. Angiogenesis starts as a result of the unbalance of these factors, where balance has a tendency toward the stimulus. One of the most important factors promoting angiogenesis is the vascular endothelial growth factor (VEGF). In addition to being involved in vascular regeneration in normal tissues, VEGF also takes part in tumor tissue angiogenesis. These factors affect endothelial cells (ECs) directly as well as differentiate tumor cells from endothelial cells and play an active role in tumor tissue angiogenesis. Angiogenesis partakes in the growth and proliferation of tumor tissue. Because anti-angiogenic treatment is favorable in existing cancer therapies, the potential benefits should be considered. One of these new therapies is cell therapy using mesenchymal stem cells (MSCs). Research on MSCs remains controversial because much of the earlier research on MSCs has shown their effectiveness, but more recent research has identified harmful effects of these cells. This article reviews the role of stem cells and their secretions in the angiogenesis of tumor tissues.

Angiogenic signaling pathways and anti-angiogenic therapy for cancer

Angiogenesis, the formation of new blood vessels, is a complex and dynamic process regulated by various pro- and anti-angiogenic molecules, which plays a crucial role in tumor growth, invasion, and metastasis. With the advances in molecular and cellular biology, various biomolecules such as growth factors, chemokines, and adhesion factors involved in tumor angiogenesis has gradually been elucidated. Targeted therapeutic research based on these molecules has driven anti-angiogenic treatment to become a promising strategy in anti-tumor therapy. The most widely used anti-angiogenic agents include monoclonal antibodies and tyrosine kinase inhibitors (TKIs) targeting vascular endothelial growth factor (VEGF) pathway. However, the clinical benefit of this modality has still been limited due to several defects such as adverse events, acquired drug resistance, tumor recurrence, and lack of validated biomarkers, which impel further research on mechanisms of tumor angiogenesis, the development of multiple drugs and the combination therapy to figure out how to improve the therapeutic efficacy. Here, we broadly summarize various signaling pathways in tumor angiogenesis and discuss the development and current challenges of anti-angiogenic therapy. We also propose several new promising approaches to improve anti-angiogenic efficacy and provide a perspective for the development and research of anti-angiogenic therapy.

Tumour suppressor PTEN activity is differentially inducible by myo-inositol phosphates

Tumour evolution and efficacy of treatments are controlled by the microenvironment, the composition of which is primarily dependent on the angiogenic reaction to hypoxic stress. Tumour angiogenesis normalization is a challenge for adjuvant therapy strategies to chemo-, radio- and immunotherapeutics. Myo-inositol trispyrophosphate (ITPP) appears to provide the means to alleviate hypoxia in the tumour site by a double molecular mechanism. First, it modifies the properties of red blood cells (RBC) to release oxygen (O₂ ) in the hypoxic sites more easily, leading to a rapid and stable increase in the partial pressure of oxygen (pO₂ ). And second, it activates the endothelial phosphatase and tensin homologue deleted on Chromosome 10 (PTEN). The hypothesis that stable normalization of the vascular system is due to the PTEN, a tumour suppressor and phosphatase which controls the proper angiogenic reaction was ascertained. Here, by direct biochemical measurements of PTEN competitive activity in relation to PIP2 production, we show that the kinetics are complex in terms of the activation/inhibition effects of ITPP with an inverted consequence towards the kinase PI3K. The use of the surface plasmon resonance (SPR) technique allowed us to demonstrate that PTEN binds inositol derivatives differently but weakly. This method permitted us to reveal that PTEN is highly sensitive to the local concentration conditions, especially that ITPP increases the PTEN activity towards PIP3, and importantly, that PTEN affinity for ITPP is considerably increased by the presence of PIP3, as occurs in vivo. Our approach demonstrates the validity of using ITPP to activate PTEN for stable vessel normalization strategies.

Ultrasound-mediated nano drug delivery for treating cancer: Fundamental physics to future directions

The application of biocompatible nanocarriers in medicine has provided several benefits over conventional treatment methods. However, achieving high treatment efficacy and deep penetration of nanocarriers in tumor tissue is still challenging. To address this, stimuli-responsive nano-sized drug delivery systems (DDSs) are an active area of investigation in delivering anticancer drugs. While ultrasound is mainly used for diagnostic purposes, it can also be applied to affect cellular function and the delivery/release of anticancer drugs. Therapeutic ultrasound (TUS) has shown potential as both a stand-alone anticancer treatment and a method to induce targeted drug release from nanocarrier systems. TUS approaches have been used to overcome various physiological obstacles, including endothelial barriers, the tumor microenvironment (TME), and immunological hurdles. Combining nanomedicine and ultrasound as a smart DDS can increase in situ drug delivery and improve access to impermeable tissues. Furthermore, smart DDSs can perform targeted drug release in response to distinctive TMEs, external triggers, or dual/multi-stimulus. This results in enhanced treatment efficacy and reduced damage to surrounding healthy tissue or organs at risk. Integrating DDSs and ultrasound is still in its early stages. More research and clinical trials are required to fully understand ultrasound's underlying physical mechanisms and interactions with various types of nanocarriers and different types of cells and tissues. In the present review, ultrasound-mediated nano-sized DDS, specifically focused on cancer treatment, is presented and discussed. Ultrasound interaction with nanoparticles (NPs), drug release mechanisms, and various types of ultrasound-sensitive NPs are examined. Additionally, in vitro, in vivo, and clinical applications of TUS are reviewed in light of the critical challenges that need to be considered to advance TUS toward an efficient, secure, straightforward, and accessible cancer treatment. This study also presents effective TUS parameters and safety considerations for this treatment modality and gives recommendations about system design and operation. Finally, future perspectives are considered, and different TUS approaches are examined and discussed in detail. This review investigates drug release and delivery through ultrasound-mediated nano-sized cancer treatment, both pre-clinically and clinically.

Nanotechnology for next-generation cancer immunotherapy: State of the art and future perspectives

Over the past decade, immunotherapy aiming to activate an effective antitumor immune response has ushered in a new era of cancer treatment. However, the efficacy of cancer immunotherapy is limited by low response rates and high systemic toxicity. Nanotechnology is an encouraging platform for the development of next-generation cancer immunotherapy to effectively treat advanced cancer. Nanotechnology-enabled immunotherapy has remarkable advantages, ranging from the increased bioavailability and stability of immunotherapeutic agents to the enhanced activation of immune cells and favorable safety profiles. Nanotechnology-enabled immunotherapy can target solid tumors through reprogramming or stimulating immune cells (i.e., nanovaccines); modulating the immunosuppressive tumor microenvironment; or targeting tumor cells and altering their responses to immune cells to generate effective antitumor immunity. In this Oration, I introduce the advanced strategies currently being pursued by our laboratory and other groups to improve the therapeutic efficacy of cancer immunotherapy and discuss the potential challenges and future directions.

Heterogeneity of cGMP signalling in tumour cells and the tumour microenvironment: Challenges and chances for cancer pharmacology and therapeutics

The second messenger cyclic guanosine monophosphate (cGMP) is an important regulator of human (patho-)physiology and has emerged as an attractive drug target. Currently, cGMP-elevating drugs are mainly used to treat cardiovascular diseases, but there is also increasing interest in exploring their potential for cancer prevention and therapy. In this review article, we summarise recent findings in cancer-related cGMP research, with a focus on melanoma, breast cancer, colorectal cancer, prostate cancer, glioma, and ovarian cancer. These studies indicate tremendous heterogeneity of cGMP signalling in tumour tissue. It appears that different tumour and stroma cells, and perhaps different sexes, express different cGMP generators, effectors, and degraders. Therefore, the same cGMP-elevating drug can lead to different outcomes in different tumour settings, ranging from inhibition to promotion of tumourigenesis or therapy resistance. These findings, together with recent evidence that increased cGMP signalling is associated with worse prognosis in several human cancers, challenge the traditional view that cGMP elevation generally has an anti-cancer effect. As cGMP pathways appear to be more stable in the stroma than in tumour cells, we suggest that cGMP-modulating drugs should preferentially target the tumour microenvironment. Indeed, there is evidence that phosphodiesterase 5 inhibitors like sildenafil enhance anti-tumour immunity by acting on immune cells. Moreover, many in vivo results obtained with cGMP-modulating drugs could be explained by effects on the tumour vasculature rather than on the tumour cells themselves. We therefore propose a model that incorporates the NO/cGMP signalling pathway in tumour vessels as a key target for cancer therapy. Deciphering the multifaceted roles of cGMP in cancer is not only a challenge for basic research, but also provides a chance to predict potential adverse effects of cGMP-modulating drugs in cancer patients and to develop novel anti-tumour therapies by precision targeting of the relevant cells and molecular pathways.

Targeted modulation of immune cells and tissues using engineered biomaterials

Therapies modulating the immune system offer the prospect of treating a wide range of conditions including infectious diseases, cancer and autoimmunity. Biomaterials can promote specific targeting of immune cell subsets in peripheral or lymphoid tissues and modulate the dosage, timing and location of stimulation, thereby improving safety and efficacy of vaccines and immunotherapies. Here we review recent advances in biomaterials-based strategies, focusing on targeting of lymphoid tissues, circulating leukocytes, tissue-resident immune cells and immune cells at disease sites. These approaches can improve the potency and efficacy of immunotherapies by promoting immunity or tolerance against different diseases.

Antibody therapeutics for epithelial ovarian cancer

INTRODUCTION

High-grade serous ovarian carcinoma (HGSC) is an aggressive subtype of epithelial ovarian carcinoma (EOC) and remains the most lethal gynecologic cancer. A lack of effective and tolerable therapeutic options and nonspecific symptoms at presentation with advanced stage of disease are among the challenges in the management of the disease.

AREAS COVERED

An overview of ovarian cancer, followed by a discussion of the current therapeutic regimes and challenges that arise during and after the treatment of EOC. We discuss different formats of antibody therapeutics and their usage in targeting validated targets implicated in ovarian cancer, as well as three emerging novel proteins as examples recently implicated in their contribution to adaptive resistance in ovarian cancer.

EXPERT OPINION

Antibody therapeutics allow for a unique and effective way to target proteins implicated in cancer and other diseases, and have the potential to radically change the outcomes of patients suffering from ovarian cancer. The vast array of targets that have been implicated in ovarian cancer and yet the lack of effective therapeutic options for patients further stresses the importance of discovering novel proteins that can be targeted, as well as predictive biomarkers that can inform the stratification of patients into treatment-specific populations.