Therapy for Cancer: Strategy of Combining Anti-Angiogenic and Target Therapies

Advancements in NSCLC: From Pathophysiological Insights to Targeted Treatments

With the global incidence of non-small cell lung cancer (NSCLC) on the rise, the development of innovative treatment strategies is increasingly vital. This review underscores the pivotal role of precision medicine in transforming NSCLC management, particularly through the integration of genomic and epigenomic insights to enhance treatment outcomes for patients. We focus on the identification of key gene mutations and examine the evolution and impact of targeted therapies. These therapies have shown encouraging results in improving survival rates and quality of life. Despite numerous gene mutations being identified in association with NSCLC, targeted treatments are available for only a select few. This paper offers an exhaustive analysis of the pathogenesis of NSCLC and reviews the latest advancements in targeted therapeutic approaches. It emphasizes the ongoing necessity for research and development in this domain. In addition, we discuss the current challenges faced in the clinical application of these therapies and the potential directions for future research, including the identification of novel targets and the development of new treatment modalities.

VEGF signaling: Role in angiogenesis and beyond

Angiogenesis is a crucial process for tissue development, repair, and tumor survival. Vascular endothelial growth factor (VEGF) is a key driver secreted by cancer cells, promoting neovascularization. While VEGF's role in angiogenesis is well-documented, its influence on the other aspects in tumor microenvironemt is less discussed. This review elaborates on VEGF's impact on intercellular interactions within the tumor microenvironment, including how VEGF affects pericyte proliferation and migration and mediates interactions between tumor-associated macrophages and cancer cells, resulting in PDL-1-mediated immunosuppression and Nrf2-mediated epithelial-mesenchymal transition. The review discusses VEGF's involvement in intra-organelle crosstalk, tumor metabolism, stemness, and epithelial-mesenchymal transition. It also provides insights into current anti-VEGF therapies and their limitations in cancer treatment. Overall, this review aims to provide a thorough overview of the current state of knowledge concerning VEGF signaling and its impact, not only on angiogenesis but also on various other oncogenic processes.

Pembrolizumab plus lenvatinib in second-line and third-line patients with pleural mesothelioma (PEMMELA): a single-arm phase 2 study

BACKGROUND

The combination of pembrolizumab, an anti-PD-1 antibody, and lenvatinib, an antiangiogenic multikinase inhibitor, shows synergistic activity in preclinical and clinical studies in solid tumours. We assessed the clinical activity of this combination therapy in patients with pleural mesothelioma who progressed after platinum-pemetrexed chemotherapy.

METHODS

In this single-arm, single-centre, phase 2 study, done at the Netherlands Cancer Institute in Amsterdam, The Netherlands, eligible patients (aged ≥18 years) with pleural mesothelioma with an Eastern Cooperative Oncology Group performance status of 0-1, progression after chemotherapy (no previous immunotherapy), and measurable disease according to the modified Response Evaluation Criteria In Solid Tumours (mRECIST) for mesothelioma version 1.1. Patients received 200 mg intravenous pembrolizumab once every 3 weeks plus 20 mg oral lenvatinib once per day for up to 2 years or until disease progression, development of unacceptable toxicity, or withdrawal of consent. The primary endpoint was objective response rate identified by a local investigator according to mRECIST version 1.1. This trial is registered with ClinicalTrials.gov, NCT04287829, and is recruiting for the second cohort.

FINDINGS

Between March 5, 2021, and Jan 31, 2022, 42 patients were screened, of whom 38 were included in the primary endpoint and safety analyses (median age 71 years [IQR 65-75], 33 [87%] male and five [13%] female) . At data cutoff (Jan 31, 2023), with a median follow-up of 17·7 months (IQR 13·8-19·4), 22 (58%; 95% CI 41-74) of 38 patients had an objective response. The independent review showed an objective response in 17 (45%; 95% CI 29-62) of 38 patients. Serious treatment-related adverse events occurred in ten (26%) patients, including one treatment-related death due to myocardial infarction. The most common treatment-related grade 3 or worse adverse events were hypertension (eight patients [21%]) and anorexia and lymphopenia (both four patients [11%]). In 29 (76%) of 38 patients, at least one dose reduction or discontinuation of lenvatinib was required.

INTERPRETATION

Pembrolizumab plus lenvatinib showed promising anti-tumour activity in patients with pleural mesothelioma with considerable toxicity, similar to that in previous studies. Available evidence from the literature suggests a high starting dose of lenvatinib for optimal anti-tumour activity. This, however, demands a high standard of supportive care. The combination therapy of pembrolizumab and lenvatinib warrants further investigation in pleural mesothelioma.

FUNDING

Merck Sharp & Dohme.

The vascular gene Apold1 is dispensable for normal development but controls angiogenesis under pathological conditions

The molecular mechanisms of angiogenesis have been intensely studied, but many genes that control endothelial behavior and fate still need to be described. Here, we characterize the role of Apold1 (Apolipoprotein L domain containing 1) in angiogenesis in vivo and in vitro. Single-cell analyses reveal that - across tissues - the expression of Apold1 is restricted to the vasculature and that Apold1 expression in endothelial cells (ECs) is highly sensitive to environmental factors. Using Apold1-/- mice, we find that Apold1 is dispensable for development and does not affect postnatal retinal angiogenesis nor alters the vascular network in adult brain and muscle. However, when exposed to ischemic conditions following photothrombotic stroke as well as femoral artery ligation, Apold1-/- mice display dramatic impairments in recovery and revascularization. We also find that human tumor endothelial cells express strikingly higher levels of Apold1 and that Apold1 deletion in mice stunts the growth of subcutaneous B16 melanoma tumors, which have smaller and poorly perfused vessels. Mechanistically, Apold1 is activated in ECs upon growth factor stimulation as well as in hypoxia, and Apold1 intrinsically controls EC proliferation but not migration. Our data demonstrate that Apold1 is a key regulator of angiogenesis in pathological settings, whereas it does not affect developmental angiogenesis, thus making it a promising candidate for clinical investigation.

Reshaping of the tumor microenvironment by cellular senescence: An opportunity for senotherapies

Cellular senescence is a stress response associated with aging and disease, including cancer. Senescent cells undergo a stable cell cycle arrest, undergo a change in morphology and metabolic reprogramming, and produce a bioactive secretome termed the senescence-associated secretory phenotype (SASP). In cancer, senescence is an important barrier to tumor progression. Induction of senescence in preneoplastic cells limits cancer initiation, and many cancer therapies act in part by inducing senescence in cancer cells. Paradoxically, senescent cells lingering in the tumor microenvironment (TME) can contribute to tumor progression, metastasis, and therapy resistance. In this review, we discuss the different types of senescent cells present in the TME and how these senescent cells and their SASP reshape the TME, affect immune responses, and influence cancer progression. Furthermore, we will highlight the importance of senotherapies, including senolytic drugs that eliminate senescent cells and impede tumor progression and metastasis by restoring anti-tumor immune responses and influencing the TME.

Dendrimers: Advancements and Potential Applications in Cancer Diagnosis and Treatment-An Overview

Cancer is a leading cause of death worldwide, and the main treatment methods for this condition are surgery, chemotherapy, and radiotherapy. These treatment methods are invasive and can cause severe adverse reactions among organisms, so nanomaterials are increasingly used as structures for anticancer therapies. Dendrimers are a type of nanomaterial with unique properties, and their production can be controlled to obtain compounds with the desired characteristics. These polymeric molecules are used in cancer diagnosis and treatment through the targeted distribution of some pharmacological substances. Dendrimers have the ability to fulfill several objectives in anticancer therapy simultaneously, such as targeting tumor cells so that healthy tissue is not affected, controlling the release of anticancer agents in the tumor microenvironment, and combining anticancer strategies based on the administration of anticancer molecules to potentiate their effect through photothermal therapy or photodynamic therapy. The purpose of this review is to summarize and highlight the possible uses of dendrimers regarding the diagnosis and treatment of oncological conditions.

Efficacy and Toxicity of Combined Inhibition of EGFR and VEGF in Patients With Advanced Non-small Cell Lung Cancer Harboring Activating EGFR Mutations: A Systematic Review and Meta-analysis

Dual inhibition of epidermal growth factor receptor (EGFR) and vascular endothelial growth factor (VEGF) pathways have demonstrated promising results for treatment of advanced non-small cell lung cancer. We conducted a systematic review and meta-analysis to assess the efficacy and toxicity of the combined treatment with EGFR tyrosine kinase inhibitors (TKIs) and VEGF blockade for patients with advanced non-small cell lung cancer harboring activating EGFR mutations, in comparison to EGFR TKIs alone. The electronic databases were searched for relevant randomized trials between 2000 and 2022. The primary endpoints were overall survival (OS) and progression-free survival. Secondary endpoints included objective response rate (ORR), disease control rate, and grade ≥3 adverse events (AEs). The pooled hazard ratios (HR) and odds ratios were meta-analyzed using the generic inverse variance and the Mantel-Haenszel methods. A total of 1528 patients from 8 trials were evaluated for analyses. The combination treatment decreased the risk of disease progression by 37% (HR=0.63; 95% CI, 0.56 to 0.72) but had no added benefit on OS compared with EGFR inhibition alone (HR=0.90; 95% CI, 0.76 to 1.05). There was no significant difference in objective response rate or disease control rate between treatments. There was a significantly increased number of AEs reported in the dual treatment arm (odds ratio=3.02; 95% CI, 1.71 to 5.31), with proteinuria and hypertension being the most significantly increased AEs. This meta-analysis suggests combined inhibition of EGFR and VEGF pathways significantly improves progression-free survival, with no OS benefit, and increases AEs. Mature OS data are needed along with results from more trials exploring this strategy with third-generation EGFR TKIs to strengthen these results.

Dynamic NIR Fluorescence Imaging and Machine Learning Framework for Stratifying High vs. Low Notch-Dll4 Expressing Host Microenvironment in Triple-Negative Breast Cancer

Delta like canonical notch ligand 4 (Dll4) expression levels in tumors are known to affect the efficacy of cancer therapies. This study aimed to develop a model to predict Dll4 expression levels in tumors using dynamic enhanced near-infrared (NIR) imaging with indocyanine green (ICG). Two rat-based consomic xenograft (CXM) strains of breast cancer with different Dll4 expression levels and eight congenic xenograft strains were studied. Principal component analysis (PCA) was used to visualize and segment tumors, and modified PCA techniques identified and analyzed tumor and normal regions of interest (ROIs). The average NIR intensity for each ROI was calculated from pixel brightness at each time interval, yielding easily interpretable features including the slope of initial ICG uptake, time to peak perfusion, and rate of ICG intensity change after reaching half-maximum intensity. Machine learning algorithms were applied to select discriminative features for classification, and model performance was evaluated with a confusion matrix, receiver operating characteristic curve, and area under the curve. The selected machine learning methods accurately identified host Dll4 expression alterations with sensitivity and specificity above 90%. This may enable stratification of patients for Dll4 targeted therapies. NIR imaging with ICG can noninvasively assess Dll4 expression levels in tumors and aid in effective decision making for cancer therapy.

Nanotechnology - a robust tool for fighting the challenges of drug resistance in non-small cell lung cancer

Genomic and proteomic mutation analysis is the standard of care for selecting candidates for therapies with tyrosine kinase inhibitors against the human epidermal growth factor receptor (EGFR TKI therapies) and further monitoring cancer treatment efficacy and cancer development. Acquired resistance due to various genetic aberrations is an unavoidable problem during EGFR TKI therapy, leading to the rapid exhaustion of standard molecularly targeted therapeutic options against mutant variants. Attacking multiple molecular targets within one or several signaling pathways by co-delivery of multiple agents is a viable strategy for overcoming and preventing resistance to EGFR TKIs. However, because of the difference in pharmacokinetics among agents, combined therapies may not effectively reach their targets. The obstacles regarding the simultaneous co-delivery of therapeutic agents at the site of action can be overcome using nanomedicine as a platform and nanotools as delivery agents. Precision oncology research to identify targetable biomarkers and optimize tumor homing agents, hand in hand with designing multifunctional and multistage nanocarriers that respond to the inherent heterogeneity of the tumors, may resolve the challenges of inadequate tumor localization, improve intracellular internalization, and bring advantages over conventional nanocarriers.

The Combination of Immune Checkpoint Blockade with Tumor Vessel Normalization as a Promising Therapeutic Strategy for Breast Cancer: An Overview of Preclinical and Clinical Studies

Immune checkpoint inhibitors (ICIs) have a modest clinical activity when administered as monotherapy against breast cancer (BC), the most common malignancy in women. Novel combinatorial strategies are currently being investigated to overcome resistance to ICIs and promote antitumor immune responses in a greater proportion of BC patients. Recent studies have shown that the BC abnormal vasculature is associated with immune suppression in patients, and hampers both drug delivery and immune effector cell trafficking to tumor nests. Thus, strategies directed at normalizing (i.e., at remodeling and stabilizing) the immature, abnormal tumor vessels are receiving much attention. In particular, the combination of ICIs with tumor vessel normalizing agents is thought to hold great promise for the treatment of BC patients. Indeed, a compelling body of evidence indicates that the addition of low doses of antiangiogenic drugs to ICIs substantially improves antitumor immunity. In this review, we outline the impact that the reciprocal interactions occurring between tumor angiogenesis and immune cells have on the immune evasion and clinical progression of BC. In addition, we overview preclinical and clinical studies that are presently evaluating the therapeutic effectiveness of combining ICIs with antiangiogenic drugs in BC patients.

AAV8-mediated sVEGFR2 and sVEGFR3 gene therapy combined with chemotherapy reduces the growth and microvasculature of human ovarian cancer and prolongs the survival in mice

Background

Vascular endothelial growth factors (VEGFs) are major regulators of intratumoral angiogenesis in ovarian cancer (OVCA). Overexpression of VEGFs is associated with increased tumor growth and metastatic tendency and VEGF-targeting therapies are thus considered as potential treatments for OVCA. Here, we examined the antiangiogenic and antitumoral effects on OVCA of adeno-associated virus 8 (AAV8)-mediated expression of soluble VEGF receptors (sVEGFRs) sVEGFR2 and sVEGFR3 together with paclitaxel and carboplatin chemotherapy.

Materials and methods

Immunodeficient mice were inoculated with human OVCA cell line SKOV-3m. Development of tumors was confirmed with magnetic resonance imaging (MRI) and mice were treated with gene therapy and paclitaxel and carboplatin chemotherapy. The study groups included (I) non-treated control group, (II) blank control vector AAV8-CMV, (III) AAV8-CMV with chemotherapy, (IV) AAV8-sVEGFR2, (V) AAV8-sVEGFR3, (VI) AAV8-sVEGFR2 and AAV8-sVEGFR3, and (VII) AAV8-sVEGFR2 and AAV8-sVEGFR3 with chemotherapy. Antiangiogenic and antitumoral effects were evaluated with immunohistochemical stainings and serial MRI.

Results

Reduced intratumoral angiogenesis was observed in all antiangiogenic gene therapy groups. The combined use of AAV8-sVEGFR2 and AAV8-sVEGFR3 with chemotherapy suppressed ascites fluid formation and tumor growth, thus improving the overall survival of mice. Antitumoral effect was mainly caused by AAV8-sVEGFR2 while the benefits of AAV8-sVEGFR3 and chemotherapy were less prominent.

Conclusion

Combined use of the AAV8-sVEGFR2 and AAV8-sVEGFR3 with chemotherapy reduces intratumoral angiogenesis and tumor growth in OVCA mouse model. Results provide preclinical proof-of-concept for the use of soluble decoy VEGFRs and especially the AAV8-sVEGFR2 in the treatment of OVCA.

Bioinformatics analysis reveals the potential target of rosiglitazone as an antiangiogenic agent for breast cancer therapy

Background

Several studies have demonstrated the antitumor activity of rosiglitazone (RGZ) in cancer cells, including breast cancer cells. However, the molecular targets of RGZ in the inhibition of angiogenesis in breast cancer cells remain unclear. This study aimed to explore the potential targets of RGZ in inhibiting breast cancer angiogenesis using bioinformatics-based analysis.

Results

Venn diagram analysis revealed 29 TR proteins. KEGG pathway enrichment analysis demonstrated that TR regulated the adipocytokine, AMPK, and PPAR signaling pathways. Oncoprint analysis showed genetic alterations in FABP4 (14%), ADIPOQ (2.9%), PPARG (2.8%), PPARGC1A (1.5%), CD36 (1.7%), and CREBBP (11%) in patients with breast cancer in a TCGA study. The mRNA levels of FABP4, ADIPOQ, PPARG, CD36, and PPARGC1A were significantly lower in patients with breast cancer than in those without breast cancer. Analysis of gene expression using bc-GenExMiner showed that the mRNA levels of FABP, ADIPOQ, PPARG, CD36, PPARGC1A, and CREBBP were significantly lower in basal-like and triple-negative breast cancer (TNBC) cells than in non-basal-like and non-TNBC cells. In general, the protein levels of these genes were low, except for that of CREBBP. Patients with breast cancer who had low mRNA levels of FABP4, ADIPOQ, PPARG, and PPARGC1A had lower overall survival rates than those with high mRNA levels, which was supported by the overall survival related to DNA methylation. Correlation analysis of immune cell infiltration with TR showed a correlation between TR and immune cell infiltration, highlighting the potential of RGZ for immunotherapy.

Conclusion

This study explored the potential targets of RGZ as antiangiogenic agents in breast cancer therapy and highlighted FABP4, ADIPOQ, PPARG, PPARGC1A, CD36, and CREBBP as potential targets of RGZ. These findings require further validation to explore the potential of RGZ as an antiangiogenic agent.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12863-022-01086-2.

Recent studies have focused on the development of indirect angiogenesis inhibitors.

Bioinformatics-based identification of potential rosiglitazone target genes to inhibit breast cancer angiogenesis.

FABP4, ADIPOQ, PPARG, PPARGC1A, CD36, and CREBBP are potential targets of rosiglitazone.

Melanoma Tumour Vascularization and Tissue-Resident Endothelial Progenitor Cells

Simple Summary

Melanoma is the most aggressive and potentially lethal form of skin cancer. Research over recent decades has highlighted the role of tumour vasculature in altering the metabolic function of cancer cells, infiltration of immune cells, and cancer cell dissemination. However, variations in the modes of vessel formation in melanoma have made this process difficult to target. In particular, the role of endothelial progenitor cells in melanoma vascularization-promoting vasculogenesis begins to be understood. Progenitor recruitment, vessel formation, and paracrine activity are among the steps contributing to tumour metastasis and affecting the impact of anti-angiogenic drugs, as detailed in this review.

Abstract

The aggressiveness of solid cancers, such as melanoma, relies on their metastatic potential. It has become evident that this key cause of mortality is largely conferred by the tumour-associated stromal cells, especially endothelial cells. In addition to their essential role in the formation of the tumour vasculature, endothelial cells significantly contribute to the establishment of the tumour microenvironment, thus enabling the dissemination of cancer cells. Melanoma tumour vascularization occurs through diverse biological processes. Vasculogenesis is the formation of de novo blood vessels from endothelial progenitor cells (EPCs), and recent research has shown the role of EPCs in melanoma tumour vascularization. A more detailed understanding of the complex role of EPCs and how they contribute to the abnormal vessel structures in tumours is of importance. Moreover, anti-angiogenic drugs have a limited effect on melanoma tumour vascularization, and the role of these drugs on EPCs remains to be clarified. Overall, targeting cancer vasculature remains a challenge, and the role of anti-angiogenic drugs and combination therapies in melanoma, a focus of this review, is an area of extensive exploration.

Inducing vascular normalization: A promising strategy for immunotherapy

In solid tumors, the vasculature is highly abnormal in structure and function, resulting in the formation of an immunosuppressive tumor microenvironment by limiting immune cells infiltration into tumors. Vascular normalization is receiving much attention as an alternative strategy to anti-angiogenic therapy, and its potential therapeutic targets include signaling pathways, angiogenesis-related genes, and metabolic pathways. Endothelial cells play an important role in the formation of blood vessel structure and function, and their metabolic processes drive blood vessel sprouting in parallel with the control of genetic signals in cancer. The feedback loop between vascular normalization and immunotherapy has been discussed extensively in many reviews. In this review, we summarize the impact of aberrant tumor vascular structure and function on drug delivery, metastasis, and anti-tumor immune responses. In addition, we present evidences for the mutual regulation of immune vasculature. Based on the importance of endothelial metabolism in controlling angiogenesis, we elucidate the crosstalk between endothelial cells and immune cells from the perspective of metabolic pathways and propose that targeting abnormal endothelial metabolism to achieve vascular normalization can be an alternative strategy for cancer treatment, which provides a new theoretical basis for future research on the combination of vascular normalization and immunotherapy.

Sanguinarine Inhibition of TNF-α-Induced CCL2, IKBKE/NF-κB/ERK1/2 Signaling Pathway, and Cell Migration in Human Triple-Negative Breast Cancer Cells

Angiogenesis is a process that drives breast cancer (BC) progression and metastasis, which is linked to the altered inflammatory process, particularly in triple-negative breast cancer (TNBC). In targeting inflammatory angiogenesis, natural compounds are a promising option for managing BC. Thus, this study was designed to determine the natural alkaloid sanguinarine (SANG) potential for its antiangiogenic and antimetastatic properties in triple-negative breast cancer (TNBC) cells. The cytotoxic effect of SANG was examined in MDA-MB-231 and MDA-MB-468 cell models at a low molecular level. In this study, SANG remarkably inhibited the inflammatory mediator chemokine CCL2 in MDA-MB-231 and MDA-MB-468 cells. Furthermore, qRT-PCR confirmed with Western analysis studies showed that mRNA CCL2 repression was concurrent with reducing its main regulator IKBKE and NF-κB signaling pathway proteins in both TNBC cell lines. The total ERK1/2 protein was inhibited in the more responsive MDA-MB-231 cells. SANG exhibited a higher potential to inhibit cell migration in MDA-MB-231 cells compared to MDA-MB-468 cells. Data obtained in this study suggest a unique antiangiogenic and antimetastatic effect of SANG in the MDA-MB-231 cell model. These effects are related to the compound’s ability to inhibit the angiogenic CCL2 and impact the ERK1/2 pathway. Therefore, SANG use may be recommended as a component of the therapeutic strategy for TNBC.

Normalization of tumor vasculature: A potential strategy to increase the efficiency of immune checkpoint blockades in cancers

Immune checkpoint inhibitors (ICIs) eliminate tumor cells by reactivating CD8 + T cells using the cytotoxic effects of the immune system. However, in this process, tumor angiogenic factors and abnormal formation of tumor blood vessels are not conducive to the treatment of ICIs. In the tumor microenvironment (TME), proangiogenic factors prevent dendritic cell maturation, reduce T cell infiltration, and recruit inhibitory immune cells such as regulatory T (Treg) cells. Abnormal tumor blood vessels also prevent immune cells and chemotherapy drugs from reaching the target effectively and lead to poor perfusion and severe hypoxia of the tumor. Treatment with antiangiogenic inhibitors can block the transmission of abnormal angiogenesis signals and promote the normalization of tumor vasculature. Therefore, the combination of antiangiogenic inhibitors and ICIs is used in clinical therapy. Combination therapy has been proven theoretically feasible in preclinical trials, and many clinical trials have been completed to confirm its safety and efficacy.

Selenium binding protein 1 inhibits tumor angiogenesis in colorectal cancers by blocking the Delta-like ligand 4/Notch1 signaling pathway

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SELENBP1 localizes to vessels and is suppressed in tumor vessels.

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SELENBP1 inhibits in vivo and in vitro angiogenesis.

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SELENBP1 antagonizes tumor angiogenesis by blocking the DLL4/Notch1 signaling pathway.

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SELENBP1 is a candidate target to treat bevacizumab-resistance in colorectal cancer.

Background

Selenium binding protein 1 (SELENBP1) is frequently downregulated in malignancies such as colorectal cancer (CRC), however, whether it is involved in tumor angiogenesis is still unknown.

Methods

We analyzed the expression and localization of SELENBP1 in vessels from CRC and neighboring tissues. We investigated the in vitro and in vivo activity of SELENBP1 in angiogenesis and explored the underlying mechanism.

Results

SELENBP1 was localized to endothelial cells in addition to glandular cells, while its vascular expression was decreased in tumor vessels compared to that in vessels from neighboring non-tumor tissues. Gain-of-function and loss-of-function experiments demonstrated that SELENBP1 inhibited angiogenesis in vitro, and blocked communications between HUVECs and CRC cells. Overexpression of SELENBP1 in CRC cells inhibited tumor growth and angiogenesis, and enhanced bevacizumab-sensitivity in a mouse subcutaneous xenograft model. Mechanic analyses revealed that SELENBP1 may suppress tumor angiogenesis by binding with Delta-like ligand 4 (DLL4) and antagonizing the DLL4/Notch1 signaling pathway. The inhibitory effects of SELENBP1 on in vitro angiogenesis could largely be rescued by DLL4.

Conclusion

These results revealed a novel role of SELENBP1 as a potential tumor suppressor that antagonizes tumor angiogenesis in CRC by intervening the DLL4/Notch1 signaling pathway.

A Weakly Supervised Deep Learning Method for Guiding Ovarian Cancer Treatment and Identifying an Effective Biomarker

Ovarian cancer is a common malignant gynecological disease. Molecular target therapy, i.e., antiangiogenesis with bevacizumab, was found to be effective in some patients of epithelial ovarian cancer (EOC). Although careful patient selection is essential, there are currently no biomarkers available for routine therapeutic usage. To the authors’ best knowledge, this is the first automated precision oncology framework to effectively identify and select EOC and peritoneal serous papillary carcinoma (PSPC) patients with positive therapeutic effect. From March 2013 to January 2021, we have a database, containing four kinds of immunohistochemical tissue samples, including AIM2, c3, C5 and NLRP3, from patients diagnosed with EOC and PSPC and treated with bevacizumab in a hospital-based retrospective study. We developed a hybrid deep learning framework and weakly supervised deep learning models for each potential biomarker, and the experimental results show that the proposed model in combination with AIM2 achieves high accuracy 0.92, recall 0.97, F-measure 0.93 and AUC 0.97 for the first experiment (66% training and 34%testing) and high accuracy 0.86 ± 0.07, precision 0.9 ± 0.07, recall 0.85 ± 0.06, F-measure 0.87 ± 0.06 and AUC 0.91 ± 0.05 for the second experiment using five-fold cross validation, respectively. Both Kaplan-Meier PFS analysis and Cox proportional hazards model analysis further confirmed that the proposed AIM2-DL model is able to distinguish patients gaining positive therapeutic effects with low cancer recurrence from patients with disease progression after treatment (p < 0.005).

CTCFL regulates the PI3K-Akt pathway and it is a target for personalized ovarian cancer therapy

High-grade serous ovarian carcinoma (HGSC) is the most lethal gynecologic malignancy due to the lack of reliable biomarkers, effective treatment, and chemoresistance. Improving the diagnosis and the development of targeted therapies is still needed. The molecular pathomechanisms driving HGSC progression are not fully understood though crucial for effective diagnosis and identification of novel targeted therapy options. The oncogene CTCFL (BORIS), the paralog of CTCF, is a transcriptional factor highly expressed in ovarian cancer (but in rarely any other tissue in females) with cancer-specific characteristics and therapeutic potential. In this work, we seek to understand the regulatory functions of CTCFL to unravel new target genes with clinical relevance. We used in vitro models to evaluate the transcriptional changes due to the presence of CTCFL, followed by a selection of gene candidates using de novo network enrichment analysis. The resulting mechanistic candidates were further assessed regarding their prognostic potential and druggability. We show that CTCFL-driven genes are involved in cytoplasmic membrane functions; in particular, the PI3K-Akt initiators EGFR1 and VEGFA, as well as ITGB3 and ITGB6 are potential drug targets. Finally, we identified the CTCFL targets ACTBL2, MALT1 and PCDH7 as mechanistic biomarkers to predict survival in HGSC. Finally, we elucidated the value of CTCFL in combination with its targets as a prognostic marker profile for HGSC progression and as putative drug targets.

Angioprevention of Urologic Cancers by Plant-Derived Foods

The number of cancer cases worldwide keeps growing unstoppably, despite the undeniable advances achieved by basic research and clinical practice. Urologic tumors, including some as prevalent as prostate, bladder or kidney tumors, are no exceptions to this rule. Moreover, the fact that many of these tumors are detected in early stages lengthens the duration of their treatment, with a significant increase in health care costs. In this scenario, prevention offers the most cost-effective long-term strategy for the global control of these diseases. Although specialized diets are not the only way to decrease the chances to develop cancer, epidemiological evidence support the role of certain plant-derived foods in the prevention of urologic cancer. In many cases, these plants are rich in antiangiogenic phytochemicals, which could be responsible for their protective or angiopreventive properties. Angiogenesis inhibition may contribute to slow down the progression of the tumor at very different stages and, for this reason, angiopreventive strategies could be implemented at different levels of chemoprevention, depending on the targeted population. In this review, epidemiological evidence supporting the role of certain plant-derived foods in urologic cancer prevention are presented, with particular emphasis on their content in bioactive phytochemicals that could be used in the angioprevention of cancer.

Role of Tumor Microenvironment in Cancer Stem Cells Resistance to Radiotherapy

Cancer is a chronic disorder that involves several elements of both the tumor and the host stromal cells. At present, the complex relationship between the various factors presents in the tumor microenvironment (TME) and tumor cells, as well as immune cells located within the TME, is still poorly known. Within the TME, the crosstalk of these factors and immune cells essentially determines how a tumor reacts to the treatment and how the tumor can ultimately be destroyed, remain dormant, or develop and metastasize. Also, in TME, reciprocal crosstalk between cancer-associated fibroblasts (CAFs), extracellular matrix (ECM), hypoxia-inducible factor (HIF) intensifies the proliferation capacity of cancer stem cells (CSCs). CSCs are subpopulation of cells that reside within the tumor bulk and have the capacity to self-renew, differentiate, and repair DNA damage. These characteristics make CSCs develop resistance to a variety of treatments, such as radiotherapy (RT). RT is a frequent and often curative treatment for local cancer which mediates tumor elimination by cytotoxic actions. Also, cytokines and growth factors that are released into TME, have been involved in the activation of tumor radioresistance and the induction of different immune cells, altering local immune responses. In this review, we discuss the pivotal role of TME in resistance of CSCs to RT.

The Role of the Tumor Microenvironment and Treatment Strategies in Colorectal Cancer

Colorectal cancer (CRC) has the second highest mortality rate among all cancers worldwide. Surgery, chemotherapy, radiotherapy, molecular targeting and other treatment methods have significantly prolonged the survival of patients with CRC. Recently, the emergence of tumor immunotherapy represented by immune checkpoint inhibitors (ICIs) has brought new immunotherapy options for the treatment of advanced CRC. As the efficacy of ICIs is closely related to the tumor immune microenvironment (TME), it is necessary to clarify the relationship between the immune microenvironment of CRC and the efficacy of immunotherapy to ensure that the appropriate drugs are selected. We herein review the latest research progress in the immune microenvironment and strategies related to immunotherapy for CRC. We hope that this review helps in the selection of appropriate treatment strategies for CRC patients.

IQ Motif-Containing GTPase-Activating Protein 2 Inhibits Breast Cancer Angiogenesis By Suppressing VEGFR2-AKT Signaling

Antiangiogenesis cancer therapies are facing setbacks due to side effects and resistance. Parallel targeting of multiple pathways can help in the development of more effective therapies. This requires the discovery of new molecules that can regulate multiple cellular processes. Our study has recently established the association of reduced IQGAP2 expression in breast cancer with EMT and poor prognosis of the patient. Existing literature indirectly suggests the role of IQGAP2 in angiogenesis that is still unexplored. In this study, we searched the role of IQGAP2 in tumor angiogenesis in a comprehensive manner using cell culture, patients, and animal models. Depletion of IQGAP2 in breast cancer cells increased proliferation, migration, and tubulogenesis of HUVECs. Findings were validated in ex ovo CAM, Matrigel plug and skin wound-healing assays in mouse model, showing that the reduction of IQGAP2 significantly increased angiogenesis. As a confirmation, IHC analysis of the patient's tissues showed a negative correlation of IQGAP2 expression with the microvessel density. Mechanistically, loss of IQGAP2 appeared to activate VEGF-A via ERK activation in tumor cells, which activated the VEGFR2-AKT axis in HUVECs. IMPLICATIONS: The findings of this study suggest the antiangiogenic properties of IQGAP2 in breast cancer. The Dual effect of IQGAP2 on EMT and angiogenesis makes it a potential target for anticancer therapy.

Recent advances in ocular drug delivery systems and targeting VEGF receptors for management of ocular angiogenesis: A comprehensive review

Background

Angiogenic ocular diseases address the main source of vision impairment or irreversible vision loss. The angiogenesis process depends on the balance between the pro-angiogenic and anti-angiogenic factors. An imbalance between these factors leads to pathological conditions in the body. The vascular endothelial growth factor is the main cause of pathological conditions in the ocular region. Intravitreal injections of anti-angiogenic drugs are selective, safe, specific and revolutionized treatment for ocular angiogenesis. But intravitreal injections are invasive techniques with other severe complications. The area of targeting vascular endothelial growth factor receptors progresses with novel approaches and therapeutically based hope for best clinical outcomes for patients through the developments in anti-angiogenic therapy.

Main text

The present review article gathers prior knowledge about the vascular endothelial growth factor and associated receptors with other angiogenic and anti-angiogenic factors involved in ocular angiogenesis. A focus on the brief mechanism of vascular endothelial growth factor inhibitors in the treatment of ocular angiogenesis is elaborated. The review also covers various recent novel approaches available for ocular drug delivery by comprising a substantial amount of research works. Besides this, we have also discussed in detail the adoption of nanotechnology-based drug delivery systems in ocular angiogenesis by comprising literature having recent advancements. The clinical applications of nanotechnology in terms of ocular drug delivery, risk analysis and future perspectives relating to the treatment approaches for ocular angiogenesis have also been presented.

Conclusion

The novel ocular drug delivery systems involving nanotechnologies are of great importance in the ophthalmological sector to overcome traditional treatments with many drawbacks. This article gives a detailed insight into the various approaches that are currently available to be a road map for future research in the field of ocular angiogenesis disease management.

Colorectal Cancer, Liver Metastases and Biotherapies

(1) Background: colorectal cancer (CRC) is one of the deadliest causes of death by cancer worldwide. Its first main metastatic diffusion spreads to the liver. Different mechanisms such as the epithelial-mesenchymal transition and angiogenesis are the characteristics of this invasion. At this stage, different options are possible and still in debate, especially regarding the use of targeted therapeutics and biotherapies. (2) Methods: A review of the literature has been done focusing on the clinical management of liver metastasis of colorectal cancer and the contribution of biotherapies in this field. (3) Results: In a clinical setting, surgeons and oncologists consider liver metastasis in CRC into two groups to launch adapted therapeutics: resectable and non-resectable. Around these two entities, the combination of targeted therapies and biotherapies are of high interest and are currently tested to know in which molecular and clinical conditions they have to be applied to impact positively both on survival and quality of life of patients.

Viewing Cancer Through the Lens of Corruption: Using Behavioral Ecology to Understand Cancer

All biological systems depend on signals for coordination: signals which pass information among agents that run the gamut from cells to organisms. However, their very importance makes signals vulnerable to subversion. How can a receiver know whether a signal is honest or deceptive? In other words, are signals necessarily a reliable indicator of agent quality or need? By drawing parallels to ecological phenomena ranging from begging by nestlings to social insects, we investigate the role of signal degradation in cancer. We thus think of cancer as a form of corruption, in which cells command huge resource investment through relatively cheap signals, just as relatively small bribes can leverage large profits. We discuss various mechanisms which prevent deceptive signaling in the natural world and within tissues. We show how cancers evolve ways to escape these controls and relate these back to evasion mechanisms in ecology. We next introduce two related concepts, co-option and collusion, and show how they play critical roles in ecology and cancer. Drawing on public policy, we propose new approaches to view treatment based on taxation, changing the incentive structure, and the recognition of corrupted signaling networks.

The cancer angiogenesis co-culture assay: In vitro quantification of the angiogenic potential of tumoroids

The treatment response to anti-angiogenic agents varies among cancer patients and predictive biomarkers are needed to identify patients with resistant cancer or guide the choice of anti-angiogenic treatment. We present “the Cancer Angiogenesis Co-Culture (CACC) assay”, an in vitro Functional Precision Medicine assay which enables the study of tumouroid induced angiogenesis. This assay can quantify the ability of a patient-derived tumouroid to induce vascularization by measuring the induction of tube formation in a co-culture of vascular cells and tumoroids established from the primary colorectal tumour or a metastasis. Furthermore, the assay can quantify the sensitivity of patient-derived tumoroids to anti-angiogenic therapies. We observed that tube formation increased in a dose-dependent manner upon treatment with the pro-angiogenic factor vascular endothelial growth factor A (VEGF-A). When investigating the angiogenic potential of tumoroids from 12 patients we found that 9 tumoroid cultures induced a significant increase in tube formation compared to controls without tumoroids. In these 9 angiogenic tumoroid cultures the tube formation could be abolished by treatment with one or more of the investigated anti-angiogenic agents. The 3 non-angiogenic tumoroid cultures secreted VEGF-A but we observed no correlation between the amount of tube formation and tumoroid-secreted VEGF-A. Our data suggests that the CACC assay recapitulates the complexity of tumour angiogenesis, and when clinically verified, could prove a valuable tool to quantify sensitivity towards different anti-angiogenic agents.

Nephrotoxicity of Anti-Angiogenic Therapies

The use of inhibitors of vascular endothelial growth factor (VEGF)/vascular endothelial growth factor receptor 2 (VEGFR2) signaling for the treatment of cancer has increased over the last decade. This signaling pathway plays a fundamental role in angiogenesis and also in kidney physiology. The emergence of anti-angiogenic therapies has led to adverse nephrotoxic effects, despite improving the outcomes of patients. In this review, we will present the different anti-angiogenic therapies targeting the VEGFR pathway in association with the incidence of renal manifestations during their use. In addition, we will discuss, in detail, the pathophysiological mechanisms of frequent renal diseases such as hypertension, proteinuria, renal dysfunction, and electrolyte disorders. Finally, we will outline the cellular damage described following these therapies.

Angiopoietin inhibitors: A review on targeting tumor angiogenesis

Angiogenesis is the process of formation of new blood vessels from existing ones. Vessels serve the purpose of providing oxygen, nutrients and removal of waste from the cells. The physiological angiogenesis is a normal process and is required in the embryonic development, wound healing, menstrual cycle. For homeostasis, balance of pro angiogenic factors and anti angiogenic factors like is important. Their imbalance causes a process known as "angiogenic switch" which leads to various pathological conditions like inflammation, tumor and restenosis. Like normal cells, tumor cells also require oxygen and nutrients to grow which is provided by tumor angiogenesis. Hence angiogenic process can be inhibited to prevent tumor growth. This gives rise to study of anti angiogenic drugs. Currently approved anti angiogenic drugs are mostly VEGF inhibitors, but VEGF inhibitors have certain limitations like toxicity, low progression free survival (PFS), and resistance to anti VEGF therapy. This article focuses on angiopoietins as alternative and potential targets for anti angiogenic therapy. Angiopoietins are ligands of Tie receptor and play a crucial role in angiogenesis, their inhibition can prevent many tumor growths even on later stages of development. We present current clinical and preclinical stages of angiopoietin inhibitors. Drugs studied in the article are selective as well as non-selective inhibitors of angiopoietin 2 like Trebananib (AMG 386), AMG 780, REGN 910, CVX 060, MEDI 3617 and dual inhibitors of angiopoietin 2 and VEGF like Vanucizumab and RG7716. The angiopoietin inhibitors show promising results alone and in combination with VEGF inhibitors in various malignancies.

ABL001, a Bispecific Antibody Targeting VEGF and DLL4, with Chemotherapy, Synergistically Inhibits Tumor Progression in Xenograft Models

Delta-like-ligand 4 (DLL4) is a promising target to augment the effects of VEGF inhibitors. A simultaneous blockade of VEGF/VEGFR and DLL4/Notch signaling pathways leads to more potent anti-cancer effects by synergistic anti-angiogenic mechanisms in xenograft models. A bispecific antibody targeting VEGF and DLL4 (ABL001/NOV1501/TR009) demonstrates more potent in vitro and in vivo biological activity compared to VEGF or DLL4 targeting monoclonal antibodies alone and is currently being evaluated in a phase 1 clinical study of heavy chemotherapy or targeted therapy pre-treated cancer patients (ClinicalTrials.gov Identifier: NCT03292783). However, the effects of a combination of ABL001 and chemotherapy on tumor vessels and tumors are not known. Hence, the effects of ABL001, with or without paclitaxel and irinotecan were evaluated in human gastric or colon cancer xenograft models. The combination treatment synergistically inhibited tumor progression compared to each monotherapy. More tumor vessel regression and apoptotic tumor cell induction were observed in tumors treated with the combination therapy, which might be due to tumor vessel normalization. Overall, these findings suggest that the combination therapy of ABL001 with paclitaxel or irinotecan would be a better clinical strategy for the treatment of cancer patients.

Combination Therapy by Tissue-Specific Suicide Gene and Bevacizumab in Intramedullary Spinal Cord Tumor

PURPOSE

Malignant gliomas are aggressive spinal cord tumors. In this study, we hypothesized that combination therapy using an anti-angiogenic agent, bevacizumab, and hypoxia-inducible glioblastoma-specific suicide gene could reduce tumor growth.

MATERIALS AND METHODS

In the present study, we evaluated the effect of combination therapy using bevacizumab and pEpo-NI2-SV-TK in reducing the proliferation of C6 cells and tumor growth in the spinal cord. Spinal cord tumor was generated by the injection of C6 cells into the T5 level of the spinal cord. Complexes of branched polyethylenimine (bPEI)/pEpo-NI2-SV-TK were injected into the spinal cord tumor. Bevacizumab was then administered by an intraperitoneal injection at a dose of 7 mg/kg. The anti-cancer effects of combination therapy were analyzed by histological analyses and magnetic resonance imaging (MRI). The Basso, Beattie and Bresnahan scale scores for all of the treatment groups were recorded every other day for 15 days to assess the rat hind-limb strength.

RESULTS

The complexes of bPEI/pEpo-NI2-SV-TK inhibited the viability of C6 cells in the hypoxia condition at 5 days after treatment with ganciclovir. Bevacizumab was decreased in the cell viability of human umbilical vein endothelial cells. Combination therapy reduced the tumor size by histological analyses and MRI. The combination therapy group showed improved hind-limb function compared to the other groups that were administered pEpo-NI2-SV-TK alone or bevacizumab alone.

CONCLUSION

This study suggests that combination therapy using bevacizumab with the pEpo-NI2-SV-TK therapeutic gene could be useful for increasing its therapeutic benefits for intramedullary spinal cord tumors.

Targeting the RhoGEF βPIX/COOL-1 in Glioblastoma: Proof of Concept Studies

Simple Summary

Glioblastoma (GBM) is an incurable disease with a 14-month average life-expectancy following diagnosis, and clinical management has not improved in four decades. GBM mortality is due to rapid tumour growth and invasion into surrounding normal brain. Invasive cells make complete surgical removal of the tumour impossible, and result in disease relapse. Thus, it is imperative that any new treatment strategy takes these invading cells into consideration. Bevacizumab (Bev), which prevents the formation of new blood vessels, is an FDA approved therapy, but it has failed to increase overall survival in GBM and has even been shown to increase tumour invasion in some cases. Complementary anti-invasive therapies are therefore urgently required to enhance bevacizumab efficacy. We have identified βPIX/COOL-1, a RhoGEF protein which plays an important role in GBM cell invasion and angiogenesis and could be a useful target in this setting.

Abstract

Glioblastoma (GBM), a highly invasive and vascular malignancy is shown to rapidly develop resistance and evolve to a more invasive phenotype following bevacizumab (Bev) therapy. Rho Guanine Nucleotide Exchange Factor proteins (RhoGEFs) are mediators of key components in Bev resistance pathways, GBM and Bev-induced invasion. To identify GEFs with enhanced mRNA expression in the leading edge of GBM tumours, a cohort of GEFs was assessed using a clinical dataset. The GEF βPix/COOL-1 was identified, and the functional effect of gene depletion assessed using 3D-boyden chamber, proliferation, and colony formation assays in GBM cells. Anti-angiogenic effects were assessed in endothelial cells using tube formation and wound healing assays. In vivo effects of βPix/COOL-1-siRNA delivered via RGD-Nanoparticle in combination with Bev was studied in an invasive model of GBM. We found that siRNA-mediated knockdown of βPix/COOL-1 in vitro decreased cell invasion, proliferation and increased apoptosis in GBM cell lines. Moreover βPix/COOL-1 mediated endothelial cell migration in vitro. Mice treated with βPix/COOL-1 siRNA-loaded RGD-Nanoparticle and Bev demonstrated a trend towards improved median survival compared with Bev monotherapy. Our hypothesis generating study suggests that the RhoGEF βPix/COOL-1 may represent a target of vulnerability in GBM, in particular to improve Bev efficacy.

Tumor-associated macrophage, angiogenesis and lymphangiogenesis markers predict prognosis of non-small cell lung cancer patients

BACKGROUND

The tumor microenvironment (TME) is a critical player in tumor progression, metastasis and therapy outcomes. Tumor-associated macrophages (TAMs) are a well-recognized core element of the TME and generally characterized as M2-like macrophages. TAMs are believed to contribute to tumor progression, but the mechanism behind this remains unclear. We aimed to investigate the clinical, angiogenic, and lymphangiogenic significance of TAMs in non-small cell lung cancer (NSCLC).

METHODS

Utilizing combined immunohistochemistry and digital image analysis, we assessed CD68, CD163, VEGF-A, and VEGF-C expression in 349 patients with NSCLC. Subsequently, the potential association between M2 TAMs and angiogenic VEGF-A and/or lymphangiogenic VEGF-C was evaluated for its prognostic value. Furthermore, the effects of M2 TAMs on angiogenesis and lymphangiogenesis were explored via an in vitro co-culture system.

RESULTS

CD68 and CD163 expression were found to directly correlate with VEGF-A and/or VEGF-C expression (all p < 0.001). Furthermore, elevated M2 ratio (CD163+/CD68+) was significantly associated with poor overall survival (p = 0.023). Dual expression of M2 ratio^high and VEGF-C^high (M2 ratio^highVEGF-C^high) was correlated with worse overall survival (p = 0.033). Multivariate analysis revealed that M2 ratio^high [HR (95% CI) = 1.53 (1.01-2.33), p = 0.046] and combined M2 ratio^highVEGF-C^high expression [HR (95% CI) = 2.01 (1.28-3.16), p = 0.003] were independent predictors of poor overall survival. Notably, we confirmed that M2 macrophages significantly enhanced the protein and mRNA expression of both VEGF-A and VEGF-C, while M1 macrophages induced only mRNA expression of VEGF-A in A549 cells.

CONCLUSIONS

This study suggests that TAMs are significantly associated with angiogenesis and lymphangiogenesis, contributing to the progression of NSCLC. Furthermore, elevated M2 ratio, similar to combined high M2 ratio and high VEGF-C expression, is a strong indicator of poor prognosis in patients with NSCLC, providing insight for future TAM-based immunotherapy strategies.

Significance of Targeting VEGFR-2 and Cyclin D1 in Luminal-A Breast Cancer

The hormonal luminal-A is the most pre-dominant sub type of breast cancer (BC), and it is associated with a high level of cyclin D1 in Saudi patients. Tamoxifen is the golden therapy for hormonal BC, but resistance of cancer cells to tamoxifen contributes to the recurrence of BC due to many reasons, including high levels of AIB1 and cyclin D1. Overcoming drug resistance could be achieved by exploring alternative targetable therapeutic pathways and new drugs or combinations. The objective of this study was to determine the differentially enriched pathways in 12 samples of Saudi women diagnosed with luminal-A using the PamChip peptide microarray-based kinase activity profiling, and to compare the activity of HAA₂₀₂₀ and dinaciclib with tamoxifen in singles and combinations in the MCF7 luminal-A cell line. Our results of network and pathway analysis of the 12 samples highlighted the importance of VEGFR and CDKs in promoting luminal-A breast cancer. The activation of VEGF signaling via VEGFR-2 leads to activation of PI3K/AKT kinases and an increase of cell survival, and leads to activation of Hsp90, which induces the phosphorylation of FAK1, resulting in cytoskeleton remodeling. PLC-gamma 1 is also activated, leading to FAK-2 and PKC activation. Notably, the G₁/S cell cycle phases and phosphorylation processes contribute to the top seven tumorigenesis processes in the 12 samples. Further, the MTT combination of HAA₂₀₂₀ and dinaciclib showed the best combination index (CI), was more clonogenic against MCF7 cells compared to the other combinations, and it also showed the best selectivity index (SI) in normal MRC5 cells. Interestingly, HAA₂₀₂₀ and dinaciclib showed a synergistic apoptotic and G₁ cell cycle effect in MCF7 cells, which was supported by their synergistic CDK2, cyclin D1, and PCNA inhibition activities. Additionally, the combination showed VEGFR-2 and Hsp90 inhibition activities in MCF7 cells. The results show the significance of targeting VEGFR-2 and cyclin D1 in Saudi luminal-A breast cancer patients, and the effect of combining HAA₂₀₂₀ and dinaciclib on those targets in the MCF7 model. It also warrants further preclinical and in vivo investigations for the combination of HAA₂₀₂₀ and dinaciclib as a possible future second-line treatment for luminal-A breast cancers.

Resistance to Anti-angiogenic Therapies: A Mechanism Depending on the Time of Exposure to the Drugs

Angiogenesis, the formation of new blood vessels from preexisting one, represents a critical process for oxygen and nutrient supply to proliferating cells, therefore promoting tumor growth and metastasis. The Vascular Endothelial Growth Factor (VEGF) pathway is one of the key mediators of angiogenesis in cancer. Therefore, several therapies including monoclonal antibodies or tyrosine kinase inhibitors target this axis. Although preclinical studies demonstrated strong antitumor activity, clinical studies were disappointing. Antiangiogenic drugs, used to treat metastatic patients suffering of different types of cancers, prolonged survival to different extents but are not curative. In this review, we focused on different mechanisms involved in resistance to antiangiogenic therapies from early stage resistance involving mainly tumor cells to late stages related to the adaptation of the microenvironment.

LCRF-0006, a small molecule mimetic of the N-cadherin antagonist peptide ADH-1, synergistically increases multiple myeloma response to bortezomib

N-cadherin is a homophilic cell-cell adhesion molecule that plays a critical role in maintaining vascular stability and modulating endothelial barrier permeability. Pre-clinical studies have shown that the N-cadherin antagonist peptide, ADH-1, increases the permeability of tumor-associated vasculature thereby increasing anti-cancer drug delivery to tumors and enhancing tumor response. Small molecule library screens have identified a novel compound, LCRF-0006, that is a mimetic of the classical cadherin His-Ala-Val sequence-containing region of ADH-1. Here, we evaluated the vascular permeability-enhancing and anti-cancer properties of LCRF-0006 using in vitro vascular disruption and cell apoptosis assays, and a well-established pre-clinical model (C57BL/KaLwRij/5TGM1) of the hematological cancer multiple myeloma (MM). We found that LCRF-0006 disrupted endothelial cell junctions in a rapid, transient and reversible manner, and increased vascular permeability in vitro and at sites of MM tumor in vivo. Notably, LCRF-0006 synergistically increased the in vivo anti-MM tumor response to low-dose bortezomib, a frontline anti-MM agent, leading to regression of disease in 100% of mice. Moreover, LCRF-0006 and bortezomib synergistically induced 5TGM1 MM tumor cell apoptosis in vitro. Our findings demonstrate the potential clinical utility of LCRF-0006 to significantly increase bortezomib effectiveness and enhance the depth of tumor response in patients with MM.

Bevacizumab (Avastin®) in cancer treatment: A review of 15 years of clinical experience and future outlook

When the VEGF-A-targeting monoclonal antibody bevacizumab (Avastin®) entered clinical practice more than 15 years ago, it was one of the first targeted therapies and the first approved angiogenesis inhibitor. Marking the beginning for a new line of anti-cancer treatments, bevacizumab remains the most extensively characterized anti-angiogenetic treatment. Initially approved for treatment of metastatic colorectal cancer in combination with chemotherapy, its indications now include metastatic breast cancer, non-small-cell lung cancer, glioblastoma, renal cell carcinoma, ovarian cancer and cervical cancer. This review provides an overview of the clinical experience and lessons learned since bevacizumab's initial approval, and highlights how this knowledge has led to the investigation of novel combination therapies. In the past 15 years, our understanding of VEGF's role in the tumor microenvironment has evolved. We now know that VEGF not only plays a major role in controlling blood vessel formation, but also modulates tumor-induced immunosuppression. These immunomodulatory properties of bevacizumab have opened up new perspectives for combination therapy approaches, which are being investigated in clinical trials. Specifically, the combination of bevacizumab with cancer immunotherapy has recently been approved in non-small-cell lung cancer and clinical benefit was also demonstrated for treatment of hepatocellular carcinoma. However, despite intense investigation, reliable and validated biomarkers that would enable a more personalized use of bevacizumab remain elusive. Overall, bevacizumab is expected to remain a key agent in cancer therapy, both due to its established efficacy in approved indications and its promise as a partner in novel targeted combination treatments.

Resistance Mechanisms to Anti-angiogenic Therapies in Cancer

Tumor growth and metastasis rely on tumor vascular network for the adequate supply of oxygen and nutrients. Tumor angiogenesis relies on a highly complex program of growth factor signaling, endothelial cell (EC) proliferation, extracellular matrix (ECM) remodeling, and stromal cell interactions. Numerous pro-angiogenic drivers have been identified, the most important of which is the vascular endothelial growth factor (VEGF). The importance of pro-angiogenic inducers in tumor growth, invasion and extravasation make them an excellent therapeutic target in several types of cancers. Hence, the number of anti-angiogenic agents developed for cancer treatment has risen over the past decade, with at least eighty drugs being investigated in preclinical studies and phase I-III clinical trials. To date, the most common approaches to the inhibition of the VEGF axis include the blockade of VEGF receptors (VEGFRs) or ligands by neutralizing antibodies, as well as the inhibition of receptor tyrosine kinase (RTK) enzymes. Despite promising preclinical results, anti-angiogenic monotherapies led only to mild clinical benefits. The minimal benefits could be secondary to primary or acquired resistance, through the activation of alternative mechanisms that sustain tumor vascularization and growth. Mechanisms of resistance are categorized into VEGF-dependent alterations, non-VEGF pathways and stromal cell interactions. Thus, complementary approaches such as the combination of these inhibitors with agents targeting alternative mechanisms of blood vessel formation are urgently needed. This review provides an updated overview on the pathophysiology of angiogenesis during tumor growth. It also sheds light on the different pro-angiogenic and anti-angiogenic agents that have been developed to date. Finally, it highlights the preclinical evidence for mechanisms of angiogenic resistance and suggests novel therapeutic approaches that might be exploited with the ultimate aim of overcoming resistance and improving clinical outcomes for patients with cancer.

Concurrent imaging of vascularization and metabolism in a mouse model of paraganglioma under anti-angiogenic treatment

Rationale: Deregulation of metabolism and induction of vascularization are major hallmarks of cancer. Using a new multimodal preclinical imaging instrument, we explored a sequence of events leading to sunitinib-induced resistance in a murine model of paraganglioma (PGL) invalidated for the expression of succinate dehydrogenase subunit B (Sdhb^-/-).

Methods: Two groups of Sdhb^-/- tumors bearing mice were treated with sunitinib (6 weeks) or vehicle (3 weeks). Concurrent Positron Emission Tomography (PET) with 2′ -deoxy-2′-[¹⁸F]fluoro-D-glucose (FDG), Computed Tomography (CT) and Ultrafast Ultrasound Imaging (UUI) imaging sessions were performed once a week and ex vivo samples were analyzed by western blots and histology.

Results: PET-CT-UUI enabled to detect a rapid growth of Sdhb^-/- tumors with increased glycolysis and vascular development. Sunitinib treatment prevented tumor growth, vessel development and reduced FDG uptake at week 1 and 2 (W1-2). Thereafter, imaging revealed tumor escape from sunitinib treatment: FDG uptake in tumors increased at W3, followed by tumor growth and vessel development at W4-5. Perfused vessels were preferentially distributed in the hypermetabolic regions of the tumors and the perfused volume increased during escape from sunitinib treatment. Finally, initial changes in total lesion glycolysis and maximum vessel length at W1 were predictive of resistance to sunitinib.

Conclusion: These results demonstrate an adaptive resistance of Sdhb^-/- tumors to six weeks of sunitinib treatment. Early metabolic changes and delayed vessel architecture changes were detectable and predictable in vivo early during anti-angiogenic treatment. Simultaneous metabolic, anatomical and functional imaging can monitor precisely the effects of anti-angiogenic treatment of tumors.

Molecular Links Between Angiogenesis and Neuroendocrine Phenotypes in Prostate Cancer Progression

As a common therapy for prostate cancer, androgen deprivation therapy (ADT) is effective for the majority of patients. However, prolonged ADT promotes drug resistance and progression to an aggressive variant with reduced androgen receptor signaling, so called neuroendocrine prostate cancer (NEPC). Until present, NEPC is still poorly understood, and lethal with no effective treatments. Elevated expression of neuroendocrine related markers and increased angiogenesis are two prominent phenotypes of NEPC, and both of them are positively associated with cancers progression. However, direct molecular links between the two phenotypes in NEPC and their mechanisms remain largely unclear. Their elucidation should substantially expand our knowledge in NEPC. This knowledge, in turn, would facilitate the development of effective NEPC treatments. We recently showed that a single critical pathway regulates both ADT-enhanced angiogenesis and elevated expression of neuroendocrine markers. This pathway consists of CREB1, EZH2, and TSP1. Here, we seek new insights to identify molecules common to pathways promoting angiogenesis and neuroendocrine phenotypes in prostate cancer. To this end, our focus is to summarize the literature on proteins reported to regulate both neuroendocrine marker expression and angiogenesis as potential molecular links. These proteins, often described in separate biological contexts or diseases, include AURKA and AURKB, CHGA, CREB1, EZH2, FOXA2, GRK3, HIF1, IL-6, MYCN, ONECUT2, p53, RET, and RB1. We also present the current efforts in prostate cancer or other diseases to target some of these proteins, which warrants testing for NEPC, given the urgent unmet need in treating this aggressive variant of prostate cancer.

AURKB Promotes the Metastasis of Gastric Cancer, Possibly by Inducing EMT

AIM

To investigate the function of Aurora kinase B (AURKB) in gastric cancer (GC).

METHODS

Immunohistochemistry was used to assay the expression of AURKB in 50 pairs of GC and adjacent tissues, and qRT-PCR was conducted to test AURKB expression in normal gastric epithelial and GC cell lines. Two segments of small interference RNAs (siRNAs) targeting AURKB were synthesized and inserted into GV248 lentivirus vector. After transfected with LV-AURKB-RNAis, CCK8, wound healing, transwell and flow cytometric assays were performed to determine the influence of silencing AURKB on cell proliferation, invasion, migration, cell cycles and apoptosis of GC cells, and the expression of EMT (epithelial-mesenchymal transition)-related markers was demonstrated by Western blots (WB).

RESULTS

AURKB was highly expressed in GC and closely associated with lymph node metastasis and advanced stages of GC. Down-regulating AURKB suppressed the proliferation and promoted the apoptosis of GC cells, arrested the cell cycle in G2/M phase, and inhibited the invasion and migration of GC cells. The expression levels of AKT1, mTOR, Myc, MMP2, and VEGFA were decreased, while the expression levels of OCLN and JUP were increased after knocking down of AURKB in both AGC and MKN45 cells.

CONCLUSION

AURKB is overexpressed in GC and closely associated with clinicopathologic characteristics of GC. It is likely that by inhibiting VEGFA/Akt/mTOR and Wnt/β-catenin/Myc pathways, silenced AURKB could inhibit the invasive and migratory abilities of GC cells. However, because of the small sample size and the absence of in-vivo experiments, these results should be verified by further studies.

MicroRNA 452 Regulates Cell Proliferation, Cell Migration, and Angiogenesis in Colorectal Cancer by Suppressing VEGFA Expression

The human microRNA 452 (MIR452) was identified as a colorectal cancer (CRC)-associated micro RNA (miRNA) by miRNA expression profiling of human CRC tissues versus normal colorectal tissues. It was significantly up-regulated in human CRC tissues. However, the functional mechanisms of MIR452 and its target genes in CRC remain unclear. We identified 27 putative MIR452 target genes, and found that the vascular endothelial growth factor A (VEGFA) was a direct target gene of MIR452. Both cellular and extracellular VEGFA levels were significantly downregulated in CRC cells upon their transfection with MIR452 or siVEGFA. VEGFA expression was frequently downregulated in human CRC tissues in comparison with that in their healthy counterparts. We showed that MIR452 regulated the expression of genes in the VEGFA-mediated signal transduction pathways vascular endothelial growth factor receptor 1 (VEGFR2)-mitogen-activated protein kinase (MAPK) and VEGFR2-SRC proto-oncogene non-receptor tyrosine kinase (SRC) in CRC cells. Immunohistological analyses of xenografted MIR452-overexpressing CRC cells in mice showed that MIR452 regulated cell proliferation and angiogenesis. Furthermore, aortic ring angiogenesis assay in rats clearly showed that the number of microvessels formed was significantly reduced by MIR452 transfection. Our findings suggest that MIR452 regulates cell proliferation, cell migration, and angiogenesis by suppressing VEGFA expression in early CRC progression; therefore, MIR452 may have therapeutic value in relation to human CRC.

miRNA‑205‑5p functions as a tumor suppressor by negatively regulating VEGFA and PI3K/Akt/mTOR signaling in renal carcinoma cells

MicroRNAs (miRNAs) are involved in the development of various types of cancers. Dysregulation of miR-205-5p has been reported in various types of human cancer. However, little is known concerning the role of miR-205-5p in renal cell carcinoma (RCC). The pr~esent study was designed to investigate the role of miR-205-5p in RCC. The expression of miR-205-5p was measured in clear cell renal cell carcinoma (ccRCC) tissues and cell lines using RT-qPCR. RCC cell lines were transfected with miR-205-5p mimics. CCK-8 assays, wound healing assays, Matrigel invasion assays and nucleosome ELISAs were used to assess the effects of miR-205-5p on cell growth, migration, invasion and apoptosis, respectively. Western blotting was employed to detect changes in protein levels. Bioinformatic analyses and luciferase reporter assays were performed to identify the potential targets of miR-205-5p. Mouse xenograft models were used to verify the effect of miR-205-5p in vivo. The expression of miR-205-5p was found to be downregulated in 25 RCC tissues compared to that noted in the adjacent normal tissues. Decreased expression of miR-205-5p was associated with poor clinical outcomes. Based on the results of the in vitro experiments, overexpression of miR-205-5p reduced RCC cell proliferation, invasion and migration. Overexpression of miR-205-5p also promoted apoptosis and inhibited the EMT in RCC cells. Moreover, the PI3K/Akt signaling pathway was found to be negatively regulated by miR-205-5p. Bioinformatic analyses and luciferase reporter assays revealed that miR-205-5p directly targeted the 3′-UTR of vascular endothelial growth factor A (VEGFA). Furthermore, miR-205-5p negatively regulated the expression of VEGFA in ccRCC cell lines. In ccRCC tissues, miR-205-5p expression was inversely correlated with VEGFA expression. Moreover, overexpression of miR-205-5p inhibited RCC growth in vivo in a mouse xenograft model. Overall, miR-205-5p functions as a tumor suppressor in RCC by targeting VEGFA and the PI3K/Akt signaling pathway, providing a potential therapeutic target for the treatment of ccRCC.

Polymer-based nanoparticles for chemo/gene-therapy: Evaluation its therapeutic efficacy and toxicity against colorectal carcinoma

Combination treatment through simultaneous delivery of anticancer drugs and gene with nano-formulation has been demonstrated to be an elegant and efficient approach for colorectal cancer therapy. Recently, sorafenib being studied in combination therapy in colorectal cancer (CRC) attracted attention of researchers. On the basis of our previous study, pigment epithelium-derived factor (PEDF) loaded nanoparticles showed good effect on CRC in vitro and in vivo. Herein, we designed a combination therapy for sorafenib (Sora), a multi-kinase inhibitor and PEDF, a powerful antiangiogenic gene, in a nano-formulation aimed to increase anti-tumor effect on CRC for the first time. Sora and PEDF were simultaneously encapsulated in PEG-PLGA based nanoparticles by a modified double-emulsion solvent evaporation method. The obtained co-encapsulated nanoparticles (Sora@PEDF-NPs) showed high entrapment efficiency of both Sora and PEDF - and exhibited a uniform spherical morphology. The release profiles of Sora and PEDF were in a sustained manner. The most effective tumor growth inhibition in the C26 cells and C26-bearing mice was observed in the Sora@PEDF-NPs in comparison with none-drug nanoparticles, free Sora, mono-drug nanoparticles (Sora-NPs and PEDF-NPs) and the mixture of Sora-NPs and equivalent PEDF-NPs (Mix-NPs). More importantly, Sora@PEDF-NPs showed lower toxicity than free Sora in mice according to the acute toxicity test. The serologic biochemical analysis and mice body weight during therapeutic period revealed that Sora@PEDF-NPs had no obvious toxicity. All the data demonstrated that the simultaneously loaded nanoparticles with multi-kinase inhibitor and anti-angiogenic gene might be one of the most potential formulations in the treatment of colorectal carcinoma in clinic and worthy of further investigation.

Combinations of Bevacizumab With Cancer Immunotherapy

Cancer immunotherapy (CIT) has transformed cancer treatment. In particular, immunotherapies targeting the programmed death ligand 1 (PD-L1)/programmed death 1 pathway have demonstrated durable clinical benefit in some patients. However, CIT combinations may create a more favorable environment in which to maximize the potential of the immune system to eliminate cancer. Here we describe 3 key mechanisms related to vascular endothelial growth factor (VEGF)-mediated immunosuppression: inhibition of dendritic cell maturation, reduction of T-cell tumor infiltration, and promotion of inhibitory cells in the tumor microenvironment; supporting data are also described. In addition, we discuss immunomodulatory properties observed within tumors following bevacizumab treatment. Combining anti-PD-L1 and anti-VEGF therapies has shown synergy and positive outcomes in phases I to III studies, particularly in settings where high VEGF levels are known to play an important role in tumor growth. We also review data from key studies supporting combination of bevacizumab and CIT, with a focus on PD-L1/programmed death 1 inhibitors.

Predictive Approach Identifies Molecular Targets and Interventions to Restore Angiogenesis in Wounds With Delayed Healing

Impaired angiogenesis is a hallmark of wounds with delayed healing, and currently used therapies to restore angiogenesis have limited efficacy. Here, we employ a computational simulation-based approach to identify influential molecular and cellular processes, as well as protein targets, whose modulation may stimulate angiogenesis in wounds. We developed a mathematical model that captures the time courses for platelets, 9 cell types, 29 proteins, and oxygen, which are involved in inflammation, proliferation, and angiogenesis during wound healing. We validated our model using previously published experimental data. By performing global sensitivity analysis on thousands of simulated wound-healing scenarios, we identified six processes (among the 133 modeled in total) whose modulation may improve angiogenesis in wounds. By simulating knockouts of 25 modeled proteins and by simulating different wound-oxygenation levels, we identified four proteins [namely, transforming growth factor (TGF)-β, vascular endothelial growth factor (VEGF), fibroblast growth factor-2 (FGF-2), and angiopoietin-2 (ANG-2)], as well as oxygen, as therapeutic targets for stimulating angiogenesis in wounds. Our modeling results indicated that simultaneous inhibition of TGF-β and supplementation of either FGF-2 or ANG-2 could be more effective in stimulating wound angiogenesis than the modulation of either protein alone. Our findings suggest experimentally testable intervention strategies to restore angiogenesis in wounds with delayed healing.

Penetration Efficiency of Antitumor Agents in Ovarian Cancer Spheroids: The Case of Recombinant Targeted Toxin DARPin-LoPE and the Chemotherapy Drug, Doxorubicin

The efficiency of delivering a therapeutic agent into a tumor is among the crucial factors determining the prospects for its clinical use. This problem is particularly acute in the case of targeted antitumor agents since many of them are high-molecular-weight compounds. In this work, the penetration of therapeutic agents of two distinct molecular weights into the spheroids of ovarian adenocarcinoma overexpressing human epidermal growth factor receptor 2 (HER2) was studied. It was shown that the low-molecular-weight chemotherapy drug, doxorubicin (~0.5 kDa), effectively penetrates through almost the entire depth of a 300 to 400 μm spheroid, while the penetration depth of the HER2-specific recombinant targeted toxin, DARPin-LoPE (~42 kDa), is only a few surface layers of cells and does not exceed 70 μm. The low penetration of the targeted toxin into spheroid was shown along with a significant decrease in its efficiency against the three-dimensional tumor spheroid as compared with the two-dimensional monolayer culture. The approaches to increasing the accumulation of agents in the tumor are presented and prospects of their use in order to improve the effectiveness of therapy are discussed.

Vascular Targeting to Increase the Efficiency of Immune Checkpoint Blockade in Cancer

Boosting natural immunity against malignant cells has had a major breakthrough in clinical cancer therapy. This is mainly due to the successful development of immune checkpoint blocking antibodies, which release a break on cytolytic anti-tumor-directed T-lymphocytes. However, immune checkpoint blockade is only effective for a proportion of cancer patients, and a major challenge in the field is to understand and overcome treatment resistance. Immune checkpoint blockade relies on successful trafficking of tumor-targeted T-lymphocytes from the secondary lymphoid organs, through the blood stream and into the tumor tissue. Resistance to therapy is often associated with a low density of T-lymphocytes residing within the tumor tissue prior to treatment. The recruitment of leukocytes to the tumor tissue relies on up-regulation of adhesion molecules and chemokines by the tumor vasculature, which is denoted as endothelial activation. Tumor vessels are often poorly activated due to constitutive pro-angiogenic signaling in the tumor microenvironment, and therefore constitute barriers to efficient leukocyte recruitment. An emerging possibility to enhance the efficiency of cancer immunotherapy is to combine pro-inflammatory drugs with anti-angiogenic therapy, which can enable tumor-targeted T-lymphocytes to access the tumor tissue by relieving endothelial anergy and increasing adhesion molecule expression. This would pave the way for efficient immune checkpoint blockade. Here, we review the current understanding of the biological basis of endothelial anergy within the tumor microenvironment, and discuss the challenges and opportunities of combining vascular targeting with immunotherapeutic drugs as suggested by data from key pre-clinical and clinical studies.