Clinical translation of angiogenesis inhibitors

Targeting the Renin-angiotensin-aldosterone System (RAAS) for Cardiovascular Protection and Enhanced Oncological Outcomes: Review

OPINION STATEMENT

The renin-angiotensin-aldosterone system (RAAS) is a crucial regulator of the cardiovascular system and a target for widely used therapeutic drugs. Dysregulation of RAAS, implicated in prevalent diseases like hypertension and heart failure, has recently gained attention in oncological contexts due to its role in tumor biology and cardiovascular toxicities (CVTs). Thus, RAAS inhibitors (RAASi) may be used as potential supplementary therapies in cancer treatment and CVT prevention. Oncological treatments have evolved significantly, impacting patient survival and safety profiles. However, they pose cardiovascular risks, necessitating strategies for mitigating adverse effects. The main drug classes used in oncology include anthracyclines, anti-HER2 therapies, immune checkpoint inhibitors (ICIs), and vascular endothelial growth factor (VEGF) signaling pathway inhibitors (VSPI). While effective against cancer, these drugs induce varying CVTs. RAASi adjunctive therapy shows promise in enhancing clinical outcomes and protecting the cardiovascular system. Understanding RAAS involvement in cancer and CVT can inform personalized treatment approaches and improve patient care.

Population pharmacokinetic model of ABL001/CTX-009 (anti-VEGF/DLL4) in adult cancer patients with solid tumor

ABL001/CTX-009 is a bispecific antibody targeting delta-like ligand-4 and vascular endothelial growth factor A. In this study, we developed a population pharmacokinetic (PK) model of ABL001/CTX-009 in patients with solid tumors. A total of 712 plasma concentrations from 30 patients with relapsed or refractory solid tumors were collected from a phase 1 study (NCT03292783). A population PK model was developed using a nonlinear mixed-effect method and was evaluated by graphical and numerical methods. Using the model, the steady-state concentrations were simulated to compare weight-based and fixed-dose regimens and to find optimal dosing intervals. The PK of ABL001/CTX-009 was well described by a two-compartment model with a parallel first-order and Michaelis-Menten elimination kinetics. Body weight was selected as a significant covariate on V1. Model evaluation results suggested that the model was adequate and robust with good precision. Simulations after administrations of fixed or weight-based doses showed similar plasma concentrations. Additionally, 10 mg/kg for every other week and 15 mg/kg for every three-week administration showed comparable plasma concentrations. In conclusion, the model well described the plasma concentrations of ABL001/CTX-009 in patients with solid tumors. The simulation suggested that weight-based dose and fixed dose can provide equivalent systemic exposure.

Targeting the tumour vasculature: from vessel destruction to promotion

As angiogenesis was recognized as a core hallmark of cancer growth and survival, several strategies have been implemented to target the tumour vasculature. Yet to date, attempts have rarely been so diverse, ranging from vessel growth inhibition and destruction to vessel normalization, reprogramming and vessel growth promotion. Some of these strategies, combined with standard of care, have translated into improved cancer therapies, but their successes are constrained to certain cancer types. This Review provides an overview of these vascular targeting approaches and puts them into context based on our subsequent improved understanding of the tumour vasculature as an integral part of the tumour microenvironment with which it is functionally interlinked. This new knowledge has already led to dual targeting of the vascular and immune cell compartments and sets the scene for future investigations of possible alternative approaches that consider the vascular link with other tumour microenvironment components for improved cancer therapy.

Integrating Vascular Phenotypic and Proteomic Analysis in an Open Microfluidic Platform

This research introduces a vascular phenotypic and proteomic analysis (VPT) platform designed to perform high-throughput experiments on vascular development. The VPT platform utilizes an open-channel configuration that facilitates angiogenesis by precise alignment of endothelial cells, allowing for a 3D morphological examination and protein analysis. We study the effects of antiangiogenic agents─bevacizumab, ramucirumab, cabozantinib, regorafenib, wortmannin, chloroquine, and paclitaxel─on cytoskeletal integrity and angiogenic sprouting, observing an approximately 50% reduction in sprouting at higher drug concentrations. Precise LC-MS/MS analyses reveal global protein expression changes in response to four of these drugs, providing insights into the signaling pathways related to the cell cycle, cytoskeleton, cellular senescence, and angiogenesis. Our findings emphasize the intricate relationship between cytoskeletal alterations and angiogenic responses, underlining the significance of integrating morphological and proteomic data for a comprehensive understanding of angiogenesis. The VPT platform not only advances our understanding of drug impacts on vascular biology but also offers a versatile tool for analyzing proteome and morphological features across various models beyond blood vessels.

Tumor angiogenesis and anti-angiogenic therapy

ABSTRACT

Anti-angiogenic drugs (AADs), which mainly target the vascular endothelial growth factor-A signaling pathway, have become a therapeutic option for cancer patients for two decades. During this period, tremendous clinical experience of anti-angiogenic therapy has been acquired, new AADs have been developed, and the clinical indications for AAD treatment of various cancers have been expanded using monotherapy and combination therapy. However, improvements in the therapeutic outcomes of clinically available AADs and the development of more effective next-generation AADs are still urgently required. This review aims to provide historical and perspective views on tumor angiogenesis to allow readers to gain mechanistic insights and learn new therapeutic development. We revisit the history of concept initiation and AAD discovery, and summarize the up-to-date clinical translation of anti-angiogenic cancer therapy in this field.

Tumor biomarkers for diagnosis, prognosis and targeted therapy

Tumor biomarkers, the substances which are produced by tumors or the body's responses to tumors during tumorigenesis and progression, have been demonstrated to possess critical and encouraging value in screening and early diagnosis, prognosis prediction, recurrence detection, and therapeutic efficacy monitoring of cancers. Over the past decades, continuous progress has been made in exploring and discovering novel, sensitive, specific, and accurate tumor biomarkers, which has significantly promoted personalized medicine and improved the outcomes of cancer patients, especially advances in molecular biology technologies developed for the detection of tumor biomarkers. Herein, we summarize the discovery and development of tumor biomarkers, including the history of tumor biomarkers, the conventional and innovative technologies used for biomarker discovery and detection, the classification of tumor biomarkers based on tissue origins, and the application of tumor biomarkers in clinical cancer management. In particular, we highlight the recent advancements in biomarker-based anticancer-targeted therapies which are emerging as breakthroughs and promising cancer therapeutic strategies. We also discuss limitations and challenges that need to be addressed and provide insights and perspectives to turn challenges into opportunities in this field. Collectively, the discovery and application of multiple tumor biomarkers emphasized in this review may provide guidance on improved precision medicine, broaden horizons in future research directions, and expedite the clinical classification of cancer patients according to their molecular biomarkers rather than organs of origin.

Dacomitinib exhibits promising activity against the rare HER2 exon 20 insertion M774delinsWLV in lung cancer: A case report and literature review

A775_G776insYVMA, the typical and predominant HER2 exon 20 insertion variant in non-small cell lung cancer, exhibits relative insensitivity to covalent HER2-targeted tyrosine kinase inhibitors. However, other less common insertions have shown better responses to HER2-targeted inhibitors. M774delinsWLV is a rare HER2 exon 20 insertion subtype and its clinical sensitivity to HER2-targeted inhibitors remains unclear. Furthermore, there is a lack of current studies to elucidate its structure and predict its sensitivity to HER2-targeted tyrosine kinase inhibitors. Herein, we presented a case of non-small cell lung cancer harboring M774delinsWLV who derived favorable response and significant survival benefit from HER2-targeted tyrosine kinase inhibitors. A 60-year-old male with metastatic lung adenocarcinoma carrying M774delinsWLV received pyrotinib monotherapy as first-line treatment. After rapid disease progression at three months, sequential combination therapy with pyrotinib and bevacizumab yielded promising antitumor activity and sustained progression-free survival benefits for nearly a year. Subsequent dacomitinib monotherapy displayed significant activity against this uncommon insertion, resulting in a rapid decrease in tumor markers and partial response, along with progression-free survival of one year. The molecular simulation revealed no significant differences in the overall protein structure and binding pocket region between M774delinsWLV and the HER2 wild type. Drug binding dynamics simulation indicated that dacomitinib exhibited the most potent binding activity compared to afatinib, pyrotinib and poziotinib. Conclusively, dacomitinib exhibited promising efficacy against the rare HER2 exon 20 insertion M774delinsWLV. Extensive investigation is needed to elucidate the effects of HER2-targeted tyrosine kinase inhibitors on non-small cell lung cancer with different HER2 insertion subtypes.

The interaction of platelet-related factors with tumor cells promotes tumor metastasis

Platelets not only participate in thrombosis and hemostasis but also interact with tumor cells and protect them from mechanical damage caused by hemodynamic shear stress and natural killer cell lysis, thereby promoting their colonization and metastasis to distant organs. Platelets can affect the tumor microenvironment via interactions between platelet-related factors and tumor cells. Metastasis is a key event in cancer-related death and is associated with platelet-related factors in lung, breast, and colorectal cancers. Although the factors that promote platelet expression vary slightly in terms of their type and mode of action, they all contribute to the overall process. Recognizing the correlation and mechanisms between these factors is crucial for studying the colonization of distant target organs and developing targeted therapies for these three types of tumors. This paper reviews studies on major platelet-related factors closely associated with metastasis in lung, breast, and colorectal cancers.

On the Importance of Acidity in Cancer Cells and Therapy

Cancer cells are associated with high glycolytic activity, which results in acidification of the tumor microenvironment. The occurrence of this stressful condition fosters tumor aggressiveness, with the outcome of invasiveness and metastasis that are linked to a poor clinical prognosis. Acidosis can be both the cause or consequence of alterations in the functions and expressions of transporters involved in intracellular acidity regulation. This review aims to explore the origin of acidity in cancer cells and the various mechanisms existing in tumors to resist, survive, or thrive in the acidic environment. It highlights the difficulties in measuring the intracellular pH evolution that impedes our understanding of the many regulatory and feedback mechanisms. It finally presents the consequences of acidity on tumor development as well as the friend or foe role of acidity in therapy.

Clonal Expansion in Cardiovascular Pathology

Clonal expansion refers to the proliferation and selection of advantageous "clones" that are better suited for survival in a Darwinian manner. In recent years, we have greatly enhanced our understanding of cell clonality in the cardiovascular context. However, our knowledge of the underlying mechanisms behind this clonal selection is still severely limited. There is a transpiring pattern of clonal expansion of smooth muscle cells and endothelial cells-and, in some cases, macrophages-in numerous cardiovascular diseases irrespective of their differing microenvironments. These findings indirectly suggest the possible existence of stem-like vascular cells which are primed to respond during disease. Subsequent clones may undergo further phenotypic changes to adopt either protective or detrimental roles. By investigating these clone-forming vascular cells, we may be able to harness this inherent clonal nature for future therapeutic intervention. This review comprehensively discusses what is currently known about clonal expansion across the cardiovascular field. Comparisons of the clonal nature of vascular cells in atherosclerosis (including clonal hematopoiesis of indeterminate potential), pulmonary hypertension, aneurysm, blood vessel injury, ischemia- and tumor-induced angiogenesis, and cerebral cavernous malformations are evaluated. Finally, we discuss the potential clinical implications of these findings and propose that proper understanding and specific targeting of these clonal cells may provide unique therapeutic options for the treatment of these cardiovascular conditions.

An Overview of the Use of Anti-Angiogenic Agents in the Treatment of Thymic Epithelial Tumors

Angiogenesis significantly influences the carcinogenesis of thymic epithelial tumors (TET). Both thymomas and thymic carcinoma (TC) overexpress VEGF-A and VEGFR-1 and -2. This review aims to provide an appraisal of the use of anti-angiogenics in the treatment of TET. The literature research identified 16 studies that were deemed eligible for further analysis. Seven studies assessed the clinical efficacy of sunitinib and five studies the use of apatinib and/or anlotinib. The multicenter Japanese phase II REMORA trial investigated the efficacy of lenvatinib, which is a multi-targeted inhibitor of VEGFR, FGFR, RET, c-Kit, and other kinases. The objective response rate was 38% (25.6-52%), which is the highest documented in TET that progressed after first-line chemotherapy. Anti-angiogenic agents may be useful in the treatment of TET, which are not amenable to curative treatment. Their toxicity profile seems to be acceptable. However, angiogenesis inhibitors do not appear to have a major influence on either thymomas or TC, although multikinase inhibitors may have some effect on TC. The current evidence suggests that the most active agent is lenvatinib, whereas sunitinib could be proposed as an acceptable second-line therapy for TC. Further research concerning the combination of immune checkpoint inhibitors with anti-angiogenic drugs is warranted.

Metronomic chemotherapy in ovarian cancer

Translational research and the development of targeted therapies have transformed the therapeutic landscape in epithelial ovarian cancer over the last decade. However, recurrent ovarian cancer continues to pose formidable challenges to therapeutic interventions, necessitating innovative strategies to optimize treatment outcomes. Current research focuses on the development of pharmaceuticals that target potential resistance pathways to DNA repair pathways. However, the cost and toxicity of some of these therapies are prohibitive and majority of patients lack access to clinical trials. Metronomic chemotherapy, characterized by the continuous administration of low doses of chemotherapeutic agents without long treatment breaks, has emerged as a promising approach with potential implications beyond recurrent setting. It acts primarily by inhibition of angiogenesis and activation of host immune system. We here review the mechanism of action of metronomic chemotherapy, as well as its current role, limitations, and avenues for further research in the management of epithelial ovarian cancer.

Aptamer-functionalized quantum dots as theranostic nanotools against cancer and bacterial infections: A comprehensive overview of recent trends

Aptamers (Apts) are synthetic nucleic acid ligands that can be engineered to target various molecules, including amino acids, proteins, and pharmaceuticals. Through a series of adsorption, recovery, and amplification steps, Apts are extracted from combinatorial libraries of synthesized nucleic acids. Using aptasensors in bioanalysis and biomedicine can be improved by combining them with nanomaterials. Moreover, Apt-associated nanomaterials, including liposomes, polymeric, dendrimers, carbon nanomaterials, silica, nanorods, magnetic NPs, and quantum dots (QDs), have been widely used as promising nanotools in biomedicine. Following surface modifications and conjugation with appropriate functional groups, these nanomaterials can be successfully used in aptasensing. Advanced biological assays can use Apts immobilized on QD surfaces through physical interaction and chemical bonding. Accordingly, modern QD aptasensing platforms rely on interactions between QDs, Apts, and targets to detect them. QD-Apt conjugates can be used to directly detect prostate, ovarian, colorectal, and lung cancers or simultaneously detect biomarkers associated with these malignancies. Tenascin-C, mucin 1, prostate-specific antigen, prostate-specific membrane antigen, nucleolin, growth factors, and exosomes are among the cancer biomarkers that can be sensitively detected using such bioconjugates. Furthermore, Apt-conjugated QDs have shown great potential for controlling bacterial infections such as Bacillus thuringiensis, Pseudomonas aeruginosa, Escherichia coli, Acinetobacter baumannii, Campylobacter jejuni, Staphylococcus aureus, and Salmonella typhimurium. This comprehensive review discusses recent advancements in the design of QD-Apt bioconjugates and their applications in cancer and bacterial theranostics.

Perspectives for Improving the Tumor Targeting of Nanomedicine via the EPR Effect in Clinical Tumors

Over the past few decades, the enhanced permeability and retention (EPR) effect of nanomedicine has been a crucial phenomenon in targeted cancer therapy. Specifically, understanding the EPR effect has been a significant aspect of delivering anticancer agents efficiently to targeted tumors. Although the therapeutic effect has been demonstrated in experimental models using mouse xenografts, the clinical translation of the EPR effect of nanomedicine faces several challenges due to dense extracellular matrix (ECM), high interstitial fluid pressure (IFP) levels, and other factors that arise from tumor heterogeneity and complexity. Therefore, understanding the mechanism of the EPR effect of nanomedicine in clinics is essential to overcome the hurdles of the clinical translation of nanomedicine. This paper introduces the basic mechanism of the EPR effect of nanomedicine, the recently discussed challenges of the EPR effect of nanomedicine, and various strategies of recent nanomedicine to overcome the limitations expected from the patients' tumor microenvironments.

Preclinical and Basic Research Strategies for Overcoming Resistance to Targeted Therapies in HER2-Positive Breast Cancer

The amplification of epidermal growth factor receptor 2 (HER2) is associated with a poor prognosis and HER2 gene is overexpressed in approximately 15-30% of breast cancers. In HER2-positive breast cancer patients, HER2-targeted therapies improved clinical outcomes and survival rates. However, drug resistance to anti-HER2 drugs is almost unavoidable, leaving some patients with an unmet need for better prognoses. Therefore, exploring strategies to delay or revert drug resistance is urgent. In recent years, new targets and regimens have emerged continuously. This review discusses the fundamental mechanisms of drug resistance in the targeted therapies of HER2-positive breast cancer and summarizes recent research progress in this field, including preclinical and basic research studies.

Nanoformulations-Based Metronomic Chemotherapy: Mechanism, Challenges, Recent Advances, and Future Perspectives

Cancer-related death is a significant health and economic burden worldwide, and some conventional chemotherapy is associated with limited effectiveness in completely curing various cancers, severe adverse effects, and destruction of healthy cells. To overcome the complications associated with conventional treatment, metronomic chemotherapy (MCT) is extensively suggested. In this review, we aim to highlight the importance of MCT over conventional chemotherapeutic approach with emphasis on nanoformulations-based MCT, their mechanism, challenges, recent advances, and future perspectives. Nanoformulations-based MCT revealed remarkable antitumor activity in both preclinical and clinical settings. For example, the metronomic scheduling of oxaliplatin-loaded nanoemulsion and polyethylene glycol-coated stealth nanoparticles incorporating paclitaxel were proven very effective in tumor-bearing mice and rats, respectively. Additionally, several clinical studies have demonstrated the benefit of MCT with acceptable tolerance. Moreover, metronomic might be a promising treatment strategy for improving cancer care in low- and middle-income nations. However, an appropriate alternative to a metronomic regimen for an individual ailment, suitable combinational delivery and scheduling, and predictive biomarkers are certain parts that remain unanswered. Further clinical-based comparative research studies are mandatory to be performed before entailing this treatment modality in clinical practice as alternative maintenance therapy or in place of transferring to therapeutic management.

Anticancer evaluation of new organometallic ruthenium(ii) flavone complexes

Targeting multiple malignancy features such as angiogenesis, proliferation and metastasis with one molecule is an effective strategy in developing potent anticancer agents. Ruthenium metal complexation to bioactive scaffolds is reported to enhance their biological activities. Herein, we evaluate the impact of Ru chelation on the pharmacological activities of two bioactive flavones (1 and 2) as anticancer candidates. The novel Ru complexes (1Ru and 2Ru) caused a loss of their parent molecules' antiangiogenic activities in an endothelial cell tube formation assay. 1Ru enhanced the antiproliferative and antimigratory activities of its 4-oxoflavone 1 on MCF-7 breast cancer cells (IC₅₀ = 66.15 ± 5 μM and 50% migration inhibition, p < 0.01 at 1 μM). 2Ru diminished 4-thioflavone's (2) cytotoxic activity on MCF-7 and MDA-MB-231 yet significantly enhanced 2's migration inhibition (p < 0.05) particularly on the MDA-MB-231 cell line. The test derivatives also showed non-intercalative interaction with VEGF and c-myc i-motif DNA sequences.

Angiogenic inhibitor pre-administration improves the therapeutic effects of immunotherapy

In lung cancer, immune checkpoint inhibitors (ICIs) are often inadequate for tumor growth inhibition. Angiogenic inhibitors (AIs) are required to normalize tumor vasculature for improved immune cell infiltration. However, in clinical practice, ICIs and cytotoxic antineoplastic agents are simultaneously administered with an AI when tumor vessels are abnormal. Therefore, we examined the effects of pre-administering an AI for lung cancer immunotherapy in a mouse lung cancer model. Using DC101, an anti-vascular endothelial growth factor receptor 2 (VEGFR2) monoclonal antibody, a murine subcutaneous Lewis lung cancer (LLC) model was used to determine the timing of vascular normalization. Microvessel density (MVD), pericyte coverage, tissue hypoxia, and CD8-positive cell infiltration were analyzed. The effects of an ICI and paclitaxel after DC101 pre-administration were investigated. On Day 3, increased pericyte coverage and alleviated tumor hypoxia represented the highest vascular normalization. CD8+ T-cell infiltration was also highest on Day 3. When combined with an ICI, DC101 pre-administration significantly reduced PD-L1 expression. When combined with an ICI and paclitaxel, only DC101 pre-administration significantly inhibited tumor growth, but simultaneous administration did not. AI pre-administration, and not simultaneous administration, may increase the therapeutic effects of ICIs due to improved immune cell infiltration.

Endothelial Progenitor Cells May Be Related to Major Amputation after Angioplasty in Patients with Critical Limb Ischemia

BACKGROUND

Critical limb ischemia represents an advanced stage of peripheral arterial disease. Angioplasty improves blood flow to the limb; however, some patients progress irreversibly to lower limb amputation. Few studies have explored the predictive potential of biomarkers during postangioplasty outcomes.

AIM

To evaluate the behavior of endothelial progenitor cells in patients with critical limb ischemia, in relation to their postangioplasty outcome.

METHODS

Twenty patients with critical limb ischemia, candidates for angioplasty, were enrolled. Flow-mediated dilation, as well as endothelial progenitor cells (subpopulations CD45+/CD34+/CD133+/CD184+ and CD45+/CD/34+/KDR[VEGFR-2]+ estimated by flow cytometry) from blood flow close to vascular damage, were evaluated before and after angioplasty. Association with lower limb amputation during a 30-day follow-up was analyzed.

RESULTS

Endothelial progenitor cells were related with flow-mediated dilation. A higher number of baseline EPCs CD45⁺CD34⁺KDR⁺, as well as an impaired reactivity of endothelial progenitor cells CD45⁺CD34⁺CD133⁺CD184⁺ after angioplasty, were observed in cases further undergoing major limb amputation, with a significant discrimination ability and risk (0.75, specificity 0.83 and RR 4.5 p < 0.05).

CONCLUSIONS

Endothelial progenitor cells were related with endothelial dysfunction, whereas a higher baseline number of the subpopulation CD45⁺CD34⁺KDR⁺, as well as an impaired reactivity of subpopulation CD45⁺CD34⁺CD133⁺CD184⁺ after angioplasty, showed a predictive ability for major limb amputation in patients with critical limb ischemia.

Advances in PET and MRI imaging of tumor hypoxia

Tumor hypoxia is a complex and evolving phenomenon both in time and space. Molecular imaging allows to approach these variations, but the tracers used have their own limitations. PET imaging has the disadvantage of low resolution and must take into account molecular biodistribution, but has the advantage of high targeting accuracy. The relationship between the signal in MRI imaging and oxygen is complex but hopefully it would lead to the detection of truly oxygen-depleted tissue. Different ways of imaging hypoxia are discussed in this review, with nuclear medicine tracers such as [¹⁸F]-FMISO, [¹⁸F]-FAZA, or [⁶⁴Cu]-ATSM but also with MRI techniques such as perfusion imaging, diffusion MRI or oxygen-enhanced MRI. Hypoxia is a pejorative factor regarding aggressiveness, tumor dissemination and resistance to treatments. Therefore, having accurate tools is particularly important.

Novel VEGFR-2 Kinase Inhibitors as Anticancer Agents: A Review Focusing on SAR and Molecular Docking Studies (2016-2021)

Cancer growth, annexation, and metastatic spread are all aided by the formation of new blood vessels (angiogenesis). The commencement of the VEGF pathway leads to signal transduction that enhances endothelial cell survival, relocation, and divergence from pre-existing vasculature. The ability of solid malignancies to bloom and spread depends critically on their ability to establish their independent blood circulation (tumor angiogenesis). VEGFR is a major receptor tyrosine kinase that regulates angiogenesis, cell growth, and metastasis, diminishing apoptosis, cytoskeletal function, and other biological processes VEGFR has proven to be a remarkable focus for a variety of anticancer medicines in clinical studies. This Review explores the development of anti-VEGF-based antiangiogenic therapies having different scaffolds. This review had focused on SAR and docking studies of previously reported molecules.

Simvastatin Enhanced Anti-tumor Effects of Bevacizumab against Lung Adenocarcinoma A549 Cells via Abating HIF-1α-Wnt/β-Catenin Signaling Pathway

BACKGROUND

Bevacizumab increased hypoxia-inducible factor (HIF-1α) expression attenuates its antitumor effect. Simvastatin can reduce the expression of HIF-1α to exert a tumor-suppressive effect in many in vitro experiments. Therefore, this study aimed to determine whether simvastatin could strengthen the anti-tumor activity of bevacizumab in lung adenocarcinoma.

OBJECTIVE

To determine whether simvastatin could strengthen the anti-tumor activity of bevacizumab in lung adenocarcinoma.

METHODS

The changes in the biological behavior of A549 cells treated with different drugs were determined through colony forming assay, Cell Counting Assay-8 (CCK-8), transwell assay, wound healing assay, and flow cytometry. The expressions of pathway-related factors HIF-1α and β-Catenin were determined via qRT-PCR and western blotting. The expressions of proliferation-related proteins, invasion-related proteins, and apoptosis-related proteins were detected by western blotting. In addition, a xenograft non-small cell lung cancer model in nude mice was used to explore in vivo tumor growth.

RESULTS

We found that simvastatin combined with bevacizumab synergistically suppressed the proliferation, migration, and invasion of A549 cells while promoting their apoptosis. As demonstrated by qRT-PCR and western blotting experiments, the bevacizumab group displayed a higher expression of pathway-related factors HIF-1α and β-Catenin than the control groups, however simvastatin group showed the opposite trend. Its combination with bevacizumab induced elevation of HIF-1α and β-catenin expressions. During in vivo experiments, simvastatin inhibited tumor growth, and in comparison, the inhibitory effects of its combination with bevacizumab were stronger.

CONCLUSION

Based on our findings, simvastatin may affect the biological responses of bevacizumab on A549 cells by restraining the HIF-1α-Wnt/β-catenin signaling pathway, thus representing a novel and effective combination therapy that can be potentially applied in a clinical therapy for lung adenocarcinoma.

Bioactive Peptides: Potential Impact on the Treatment of Gastrointestinal Cancers

We have reviewed the potential use of bioactive peptides in the treatment of gastrointestinal (GI) malignancies, which are a significant cause of morbidity and mortality globally. Conventional therapies, such as surgery, chemotherapy, and radiotherapy, are associated with numerous side effects that may lead to longterm complications. Bioactive peptides are short-chain amino acids that can be extracted from natural sources or synthesized, and they have various potential health benefits, including anti-inflammatory, anti-hypertensive, antioxidant, antimicrobial, and anti-cancer properties. Bioactive peptides can be acquired from animal or plant sources, and can be classified based on their function, such as ACE-inhibiting, antimicrobial, and electrolyte- regulating peptides. Recent studies have demonstrated the promising role of bioactive peptides in tumor suppression, especially when combined with conventional therapies. In this study, we have reviewed the beneficial properties of bioactive peptides and their role in suppressing tumor activity. The mechanisms of bioactive peptides in tumor suppression are discussed. We have further reviewed the findings of preclinical and clinical studies that have investigated the application of bioactive peptides in the treatment of GI cancers. This review highlights the potential use of bioactive peptides as a promising treatment method for GI malignancies to increase the quality of life of GI cancer patients.

Neomycin, but Not Neamine, Blocks Angiogenic Factor Induced Nitric Oxide Release through Inhibition of Akt Phosphorylation

Angiogenesis, the growth of new blood vessels, is a critical factor of carcinogenesis. Neomycin and neamine, two drugs blocking the nuclear translocation of angiogenin (ANG), have been proven to inhibit tumour growth in vivo. However, the high toxicity of neomycin prevents its therapeutic use, thus indicating that the less toxic neamine may be a better candidate. Endothelial cells were cultured on a biocompatible multiple microelectrode array (MMA). The release of NO evoked by ANG or vascular endothelial growth factor (VEGF) was detected electrochemically. The effects of neomycin and neamine on ANG- and VEGF-induced NO releases have been investigated. Neomycin totally blocks NO release for concentrations down to the pM range, probably through the inhibition of the Akt kinase phosphorylation, as revealed by confocal microscopy. On the other hand, both ANG- and VEGF-induced NO releases were not significantly hindered by the presence of high concentrations of neamine. The inhibition of the Akt pathway and NO release are expected to lead to a severe decrease in tissue growth and repair, thus indicating a possible cause for the toxicity of neomycin. Furthermore, the data presented here show that ANG- and VEGF-induced NO releases are not dependent on the nuclear translocation of angiogenin, as these events were not abolished by the presence of neamine.

Selected Factors of Vascular Changes: The Potential Pathological Processes Underlying Primary Headaches in Children

Background: The prevalence, social consequences and complicated pathogenesis make headaches in children a significant clinical issue. Studies in adults suggest that primary headaches could be the first sign of atherosclerosis and platelet aggregation. Aim: To analyze the blood levels of selected biomarkers of vascular changes potentially associated with a higher risk of atherosclerosis in children with primary headaches. Methods: The medical family history, brain-derived neurotrophic factor (BDNF), soluble CD40 ligands (sCD40L), endothelial plasminogen activator inhibitor (PAI I), vascular endothelial growth factor (VEGF) and intima-media thickness (IMT) measurements were performed in the 83 children (52 with primary headaches, 31 controls). Selected factors were compared with basic laboratory parameters that are potentially related to atherosclerosis: C-reactive protein (CRP) and lipid concentration. Results: There were no significant differences in biomarkers of vascular changes in the study group and controls in general. In the study group, boys had a higher BDNF level than girls (p = 0.046). Normal-weight migraine patients had significantly higher PAI-I levels than controls (p = 0.034). A positive correlation between PAI-1 and triglycerides (TG) was observed. IMT did not differ between children with primary headaches and controls; however, IMT showed a positive correlation with BMI z-score and TG. Children with headaches had, more often, a positive family history of cardiovascular disease (p = 0.049). Conclusions: There were no clear clinical changes indicative of atherosclerosis in the study population. However, some trends are visible. Primary headaches are more often related to a family history of cardiovascular diseases. IMT is associated with TG levels and BMI z-score. The measured biomarkers of vascular changes show mutual relations.

Anticancer peptides mechanisms, simple and complex

Peptide therapy has started since 1920s with the advent of insulin application, and now it has emerged as a new approach in treatment of diseases including cancer. Using anti-cancer peptides (ACPs) is a promising way of cancer therapy as ACPs are continuing to be approved and arrived at major pharmaceutical markets. Traditional cancer treatments face different problems like intensive adverse effects to patient's body, cell resistance to conventional chemical drugs and in some worse cases the occurrence of cell multidrug resistance (MDR) of cancerous tissues against chemotherapy. On the other hand, there are some benefits conceived for peptides usage in treatment of diseases specifically cancer, as these compounds present favorable characteristics such as smaller size, high activity, low immunogenicity, good biocompatibility in vivo, convenient and rapid way of synthesis, amenable to sequence modification and revision and there is no limitation for the type of cargo they carry. It is possible to achieve an optimum molecular and functional structure of peptides based on previous experience and bank of peptide motif data which may result in novel peptide design. Bioactive peptides are able to form pores in cell membrane and induce necrosis or apoptosis of abnormal cells. Moreover, recent researches have focused on the tumor recognizing peptide motifs with the ability to permeate to cancerous cells with the aim of cancer treatment at earlier stages. In this strategy the most important factors for addressing cancer are choosing peptides with easy accessibility to tumor cell without cytotoxicity effect towards normal cells. The peptides must also meet acceptable pharmacokinetic requirements. In this review, the characteristics of peptides and cancer cells are discussed. The various mechanisms of peptides' action proposed against cancer cells make the next part of discussion. It will be followed by giving information on peptides application, various methods of peptide designing along with introducing various databases. Future aspects of peptides for employing in area of cancer treatment come as conclusion at the end.

Extracellular vesicles as central regulators of blood vessel function in cancer

Blood vessels deliver oxygen and nutrients that sustain tumor growth and enable the dissemination of cancer cells to distant sites and the recruitment of intratumoral immune cells. In addition, the structural and functional abnormalities of the tumor vasculature foster the development of an aggressive tumor microenvironment and impair the efficacy of existing cancer therapies. Extracellular vesicles (EVs) have emerged as major players of tumor progression, and a growing body of evidence has demonstrated that EVs derived from cancer cells trigger multiple responses in endothelial cells that alter blood vessel function in tumors. EV-mediated signaling in endothelial cells can occur through the transfer of functional cargos such as miRNAs, lncRNAs, cirRNAs, and proteins. Moreover, membrane-bound proteins in EVs can elicit receptor-mediated signaling in endothelial cells. Together, these mechanisms reprogram endothelial cells and contribute to the sustained exacerbated angiogenic signaling typical of tumors, which, in turn, influences cancer progression. Targeting these angiogenesis-promoting EV-dependent mechanisms may offer additional strategies to normalize tumor vasculature. Here, we discuss the current knowledge pertaining to the contribution of cancer cell-derived EVs in mechanisms regulating blood vessel functions in tumors. Moreover, we discuss the translational opportunities in targeting the dysfunctional tumor vasculature using EVs and highlight the open questions in the field of EV biology that can be addressed using mass spectrometry-based proteomics analysis.

Pyrotinib combined with apatinib for targeting metastatic non-small cell lung cancer with HER2 alterations: a prospective, open-label, single-arm phase 2 study (PATHER2)

BACKGROUND

Although targeted agents have been gradually applied in the treatment of HER2-mutated non-small cell lung cancer (NSCLC) in recent years, patients' therapeutic demands are far from being met. PATHER2 was the first phase 2 trial to explore the efficacy and safety of the HER2-targeted tyrosine kinase inhibitor (TKI) pyrotinib plus the antiangiogenic agent apatinib in previously treated HER2-altered metastatic NSCLC patients.

METHODS

HER2-mutated or HER2-amplified metastatic NSCLC patients who had failed at least first-line chemotherapy or HER2-targeted TKIs received oral pyrotinib 400 mg plus apatinib 250 mg once daily until disease progression, intolerable toxicity, or death. The primary endpoint was the investigator-assessed objective response rate (ORR).

RESULTS

Between March 2019 and December 2020, 33 patients were enrolled; 13 (39.4%) presented brain metastases, and 16 (48.5%) had received at least two lines of prior chemotherapy or HER2-targeted TKIs. As of September 20, 2021, the median follow-up duration was 11.3 (range, 3.5-26.0) months. The investigator-assessed ORR was 51.5% (17/33; 95% CI, 33.5 to 69.2%), and the disease control rate was 93.9% (31/33; 95% CI, 79.8 to 99.3%). The median duration of response, progression-free survival, and overall survival were 6.0 (95% CI, 4.4 to 8.6) months, 6.9 (95% CI, 5.8 to 8.5) months, and 14.8 (95% CI, 10.4 to 23.8) months, respectively. The most frequent grade ≥ 3 treatment-related adverse events included diarrhea (3.0%) and hypertension (9.1%). No treatment-related deaths were reported.

CONCLUSIONS

Pyrotinib plus apatinib demonstrated promising antitumor activity and a manageable safety profile in HER2-mutated or HER2-amplified metastatic NSCLC patients.

TRIAL REGISTRATION

Chinese Clinical Trial Registry Identifier: ChiCTR1900021684 .

Hypoxia‐induced ELF3 promotes tumor angiogenesis through IGF1/IGF1R

Epithelial ovarian cancer (EOC) is one of the most lethal gynecological cancers despite a relatively low incidence. Angiogenesis, one of the hallmarks of cancer, is essential for the pathogenesis of EOC, which is related to the induction of angiogenic factors. We found that ELF3 was highly expressed in EOCs under hypoxia and functioned as a transcription factor for IGF1. The ELF3‐mediated increase in the secretion of IGF1 and VEGF promoted endothelial cell proliferation, migration, and EOC angiogenesis. Although this situation was much exaggerated under hypoxia, ELF3 silencing under hypoxia significantly attenuated angiogenic activity in endothelial cells by reducing the expression and secretion of IGF1 and VEGF. ELF3 silencing attenuated angiogenesis and tumorigenesis in ex vivo and xenograft mouse models. Consequently, ELF3 plays an important role in the induction of angiogenesis and tumorigenesis in EOC as a transcription factor of IGF1. A detailed understanding of the biological mechanism of ELF3 may both improve current antiangiogenic therapies and have anticancer effects for EOC.

Halogenated Flavonoid Derivatives Display Antiangiogenic Activity

Antiangiogenic agents attenuate tumours' growth and metastases and are therefore beneficial as an adjuvant or standalone cancer regimen. Drugs with dual antiproliferative and antiangiogenic activities can achieve anticancer efficacy and overcome acquired resistance. In this study, synthetic flavones (5a,b) with reported anticancer activity, and derivatives (4b and 6a), exhibited significant inhibition of endothelial cell tube formation (40-55%, 12 h) at 1 µM, which is comparable to sunitinib (50% inhibition at 1 µM, 48 h). Flavones (4b, 5a,b and 6a) also showed 25-37% reduction in HUVECs migration at 10 µM. In a Western blotting assay, 5a and 5b subdued VEGFR2 phosphorylation by 37% and 57%, respectively, suggesting that VEGFR2 may be their main antiangiogenic target. 5b displayed the best docking fit with VEGFR2 in an in silico study, followed by 5a, emphasizing the importance of the 7-hydroxyl group accompanied by a 4-C=S for activity. Conversely, derivatives with a 4-carbonyl moiety fitted poorly into the target's binding pocket, suggesting that their antiangiogenic activity depends on a different target. This study provides valuable insight into the Structure Activity Relationships (SAR) and modes of action of halogenated flavones with VEGFR2 and highlights their therapeutic potential as antiangiogenic/anticancer lead compounds.

Design, synthesis and evaluation of novel tetrahydropyridothienopyrimidin-ureas as cytotoxic and anti-angiogenic agents

The novel derivatives of tetrahydropyridothienopyrimidine-based compounds have been designed and efficiently synthesized with good yields through seven steps reaction. The anticancer activity of compounds 11a-y has been evaluated against MCF-7, PC-3, HEPG-2, SW-480, and HUVEC cell lines by MTT assay. The target compounds showed IC₅₀ values between 2.81–29.6 μg/mL and were compared with sorafenib as a reference drug. Among them, compound 11n showed high cytotoxic activity against four out of five examined cell lines and was 14 times more selective against MRC5. The flow cytometric analysis confirmed the induction of apoptotic cell death by this compound against HUVEC and MCF-7 cells. In addition, 11n caused sub-G1 phase arrest in the cell cycle arrest. Besides, this compound induced anti-angiogenesis in CAM assay and increased the level of caspase-3 by 5.2 fold. The western-blot analysis of the most active compound, 11n, revealed the inhibition of VEGFR-2 phosphorylation. Molecular docking study also showed the important interactions for compound 11n.

Biological aspects in controlling angiogenesis: current progress

All living beings continue their life by receiving energy and by excreting waste products. In animals, the arteries are the pathways of these transfers to the cells. Angiogenesis, the formation of the arteries by the development of pre-existed parental blood vessels, is a phenomenon that occurs naturally during puberty due to certain physiological processes such as menstruation, wound healing, or the adaptation of athletes' bodies during exercise. Nonetheless, the same life-giving process also occurs frequently in some patients and, conversely, occurs slowly in some physiological problems, such as cancer and diabetes, so inhibiting angiogenesis has been considered to be one of the important strategies to fight these diseases. Accordingly, in tissue engineering and regenerative medicine, the highly controlled process of angiogenesis is very important in tissue repairing. Excessive angiogenesis can promote tumor progression and lack of enough angiogensis can hinder tissue repair. Thereby, both excessive and deficient angiogenesis can be problematic, this review article introduces and describes the types of factors involved in controlling angiogenesis. Considering all of the existing strategies, we will try to lay out the latest knowledge that deals with stimulating/inhibiting the angiogenesis. At the end of the article, owing to the early-reviewed mechanical aspects that overshadow angiogenesis, the strategies of angiogenesis in tissue engineering will be discussed.

Synthesis and Characterization of Novel Copper(II)-Sunitinib Complex: Molecular Docking, DFT Studies, Hirshfeld Analysis and Cytotoxicity Studies

The main goal of this work was to report the synthesis, characterization, and cytotoxicity study of a novel copper(II)-sunitinib complex, CuSun. It has been synthesized and characterized in solid state and in solution by different methods (such as DFT, FTIR, Raman, UV-vis, EPR, NMR, etc.). The solid-state molecular structure of trichlorosunitinibcopper(II), where sunitinib: N-[2-(diethylamino)ethyl]-5-[(Z)-(5-fluoro-2-oxo-1H-indol-3-ylidene)methyl]-2,4-dimethyl-1H-pyrrole-3-carboxamide, for short Cu(Sun)Cl3, was determined by X-ray diffraction. It crystallizes in the triclinic space group P-1 with a = 7.9061(5) Å, b = 12.412(1) Å, c = 13.7005(8) Å, α = 105.021(6)°, β = 106.744(5)°, γ = 91.749(5)°, and Z = 2 molecules per unit cell. Also, we have found π-π interactions and classic and non-classic H-bonds in the crystal structure by using Hirshfeld surface analysis. In the speciation studies, the complex has dissociated in protonated sunitinib and chlorocomplex of copper(II), according to 1HNMR, EPR, UV-vis and conductimetric analysis. Molecular docking of the complex in both, ATP binding site and allosteric site of VEGFR2 have shown no improvement in comparison to the free ligand. Besides, cytotoxicity assay on HepG2 cell line shows similar activity for complex and ligand in the range between 1–25 μM supporting the data obtained from studies in solution.

Incorporation of Functionalized Calcium Phosphate Nanoparticles in Living Cells

Intracellular calcium (Ca2+) is a key signaling element that is involved in a great variety of fundamental biological processes. Thus, Ca2+ deregulation would be involved in the cancer cell progression and damage of mitochondrial membrane and DNA, which lead to apoptosis and necrosis. In this study, we have prepared amorphous calcium phosphate nanoparticles (ACP NPs) for studied their incorporation by endocytosis or electroporation to epithelial, endothelial and fibroblast cells (MCF-7, HUVEC and COS-1 cells, respectively). Our results showed that internalized ACP NPs have cytotoxic effects as a consequence of the increase of the intracellular calcium content. The endocytosis pathways showed a greater cytotoxic effect since calcium ions could easily be released from the nanoparticles and be accumulated in the lysosomes and mitochondria. In addition, the cytotoxic effect could be reversed when calcium ion was chelated with ethylene glycol-bis(2-aminoethylether)-N,N,N′,N′-tetraacetic acid (EGTA). Modification of ACP NPs by coating with different compounds based on phosphates was also evaluated. The results indicated a reduction of the cytotoxic effect, in the order polyphosphate < phosphonic acid < orthophosphate. A differential cytotoxic effect of ACP-NPs was observed in function of the cell type; the cytotoxic effect can be ordered as i.e., HUVEC > COS-1 > MCF-7. The greater cytotoxic effect caused by the increase of intracellular calcium that is observed in normal cells and the greater resistance of cancer cells suggests new perspectives for cancer research.

Effect of Peptide Receptor Radionuclide Therapy in Combination with Temozolomide against Tumor Angiogenesis in a Glioblastoma Model

Cell adhesion receptor integrin α_vβ₃ is a promising biomarker for developing tumor-angiogenesis targeted theranostics. In this study, we aimed to examine the therapeutic potential of peptide receptor radionuclide therapy (PRRT) with ¹⁸⁸Re-IDA-D-[c(RGDfK)]₂ (11.1 MBq). The results showed that the tumor volume was significantly decreased by 81% compared with the vehicle-treated group in U87-MG xenografts. The quantitative in vivo anti-angiogenic responses of PRRT were obtained using ^99mTc-IDA-D-[c(RGDfK)]₂ SPECT and corresponded to the measured tumor volume. PRRT combined with temozolomide (TMZ) resulted in a 93% reduction in tumor volume, which was markedly greater than that of each agent used individually. In addition, histopathological characterization showed that PRRT combined with TMZ was superior to PRRT or TMZ alone, even when TMZ was used at half dose. Overall, our results indicated that integrin-targeted PRRT and TMZ combined therapy might be a new medical tool for the effective treatment of glioblastoma.

Anticancer Effects of the Corchorus olitorius Aqueous Extract and Its Bioactive Compounds on Human Cancer Cell Lines

Corchorus olitorius is a common, leafy vegetable locally known as “Saluyot” in the Philippines. Several studies have reported on its various pharmacological properties, such as antioxidant, anti-inflammatory, analgesic, and anticancer properties. However, little is known about its effects on angiogenesis. This study aimed to evaluate the anticancer properties, such as the antiproliferative, anti-angiogenic, and antitumor activities, of the C. olitorius aqueous extract (CO) and its bioactive compounds, chlorogenic acid (CGA) and isoquercetin (IQ), against human melanoma (A-375), gastric cancer (AGS), and pancreatic cancer (SUIT-2), using in vitro and in ovo biological assays. The detection and quantification of CGA and IQ in CO were achieved using LC-MS/MS analysis. The antiproliferative, anti-angiogenic, and antitumor activities of CO, CGA, and IQ against A-375, AGS, and SUIT-2 cancer cell lines were evaluated using MTT and CAM assays. CGA and IQ were confirmed to be present in CO. CO, CGA, and IQ significantly inhibited the proliferation of A-375, AGS, and SUIT-2 cancer cells in a dose-dependent manner after 48 h of treatment. Tumor angiogenesis (hemoglobin levels) of A-375 and AGS tumors was significantly inhibited by CO, CGA, IQ, and a CGA–IQ combination. The growth of implanted A-375 and AGS tumors was significantly reduced by CO, CGA, IQ, and a CGA–IQ combination, as measured in tumor weight. Our investigation provides new evidence to show that CO has promising anticancer effects on various types of human cancer cells. CO and its compounds are potential nutraceutical products that could be used for cancer treatment.

Isookanin Inhibits PGE2-Mediated Angiogenesis by Inducing Cell Arrest through Inhibiting the Phosphorylation of ERK1/2 and CREB in HMEC-1 Cells

Inflammation is increasingly recognized as a critical mediator of angiogenesis, and unregulated angiogenic responses often involve human diseases. The importance of regulating angiogenesis in inflammatory diseases has been demonstrated through some successful cases of anti-angiogenesis therapies in related diseases, including arthritis, but it has been reported that some synthetic types of antiangiogenic drugs have potential side effects. In recent years, the importance of finding alternative strategies for regulating angiogenesis has begun to attract the attention of researchers. Therefore, identification of natural ingredients used to prevent or treat angiogenesis-related diseases will play a greater role. Isookanin is a phenolic flavonoid presented in Bidens extract, and it has been reported that isookanin possesses some biological properties, including antioxidative and anti-inflammatory effects, anti-diabetic properties, and an ability to inhibit α-amylase. However, its antiangiogenic effects and mechanism thereof have not been studied yet. In this study, our results indicate that isookanin has an effective inhibitory effect on the angiogenic properties of microvascular endothelial cells. Isookanin shows inhibitory effects in multiple stages of PGE₂-induced angiogenesis, including the growth, proliferation, migration, and tube formation of microvascular endothelial cells. In addition, isookanin induces cell cycle arrest in S phase, which is also the reason for subsequent inhibition of cell proliferation. The mechanism of inhibiting angiogenesis by isookanin is related to the inhibition of PGE₂-mediated ERK1/2 and CREB phosphorylation. These findings make isookanin a potential candidate for the treatment of angiogenesis-related diseases.

An updated patent review of VEGFR-2 inhibitors (2017-present)

Introduction: Angiogenesis is a vital process for cellular functions in both physiological and pathophysiological conditions and is one of the hallmarks of cancer progression and metastasis. VEGF/VEGFR-2 signaling pathway has been recognized as the most critical factor in promoting angiogenesis. Hence, several VEGFR-2 inhibitors have been clinically tested and/or approved for the treatment of angiogenesis-related diseases.Areas covered: This review covered reports in the patent literature in the period 2017 to the end of 2020 on the small-molecule inhibitors and antibodies of VEGFR-2 and their potential use as therapeutics for several types of cancers, angiogenesis-related disorders, and Parkinson's and Alzheimer's diseases.Expert opinion: VEGF inhibition has attracted considerable attention as a potential approach for antiangiogenic therapy during the last two decades. However, the effectiveness of this approach may be limited by several issues such as weak response, resistance development, and serious adverse effects. Therefore, the combination of anti-angiogenic therapy with chemotherapy and/or immunotherapy, together with the proper utilization of nanomedicine-based approaches, may have a synergistic effect on improving the efficiency of therapy, reducing side effects and lowering the cost.

Histone deacetylase 10, a potential epigenetic target for therapy

Histone deacetylase (HDAC) 10, a class II family, has been implicated in various tumors and non-tumor diseases, which makes the discovery of biological functions and novel inhibitors a fundamental endeavor. In cancers, HDAC10 plays crucial roles in regulating various cellular processes through its epigenetic functions or targeting some decisive molecular or signaling pathways. It also has potential clinical utility for targeting tumors and non-tumor diseases, such as renal cell carcinoma, prostate cancer, immunoglobulin A nephropathy (IgAN), intracerebral hemorrhage, human immunodeficiency virus (HIV) infection and schizophrenia. To date, relatively few studies have investigated HDAC10-specific inhibitors. Therefore, it is important to study the biological functions of HDAC10 for the future development of specific HDAC10 inhibitors. In this review, we analyzed the biological functions, mechanisms and inhibitors of HDAC10, which makes HDAC10 an appealing therapeutic target.

Biodegradable Dendritic Polyglycerol Sulfate for the Delivery and Tumor Accumulation of Cytostatic Anticancer Drugs

Targeted delivery and extended blood circulation of anticancer drugs have been the challenges for decreasing the adverse side effects and improving the therapeutic efficiency in cancer chemotherapy. Herein, we present a drug delivery system (DDS) based on biodegradable dendritic polyglycerol sulfate-bearing poly(caprolactone) (dPGS-PCL) chains, which has been synthesized on 20 g scale using a straightforward two-step protocol. In vivo fluorescence imaging demonstrated a significant accumulation of the DDS in the tumor environment. Sunitinib, an anticancer drug, was loaded into the DDS and the drug-induced toxicity was investigated in vitro and in vivo. The drug encapsulated in dPGS-PCL and the free drug showed similar toxicities in A431 and HT-29 cells, and the cellular uptake was comparable. The straightforward and large-scale synthesis, the organic solvent-free drug-loading approach, together with the tumor targetability of the biodegradable dendritic polyglycerols, render this copolymer a promising candidate for targeted cancer nanomedicine drug delivery systems.

Small molecules in targeted cancer therapy: advances, challenges, and future perspectives

Due to the advantages in efficacy and safety compared with traditional chemotherapy drugs, targeted therapeutic drugs have become mainstream cancer treatments. Since the first tyrosine kinase inhibitor imatinib was approved to enter the market by the US Food and Drug Administration (FDA) in 2001, an increasing number of small-molecule targeted drugs have been developed for the treatment of malignancies. By December 2020, 89 small-molecule targeted antitumor drugs have been approved by the US FDA and the National Medical Products Administration (NMPA) of China. Despite great progress, small-molecule targeted anti-cancer drugs still face many challenges, such as a low response rate and drug resistance. To better promote the development of targeted anti-cancer drugs, we conducted a comprehensive review of small-molecule targeted anti-cancer drugs according to the target classification. We present all the approved drugs as well as important drug candidates in clinical trials for each target, discuss the current challenges, and provide insights and perspectives for the research and development of anti-cancer drugs.

Metronomic Chemotherapy

Simple Summary

The present article reviews the state of the art of metronomic chemotherapy use to treat the principal types of cancers, namely breast, non-small cell lung cancer and colorectal ones, and of the most recent progresses in understanding the underlying mechanisms of action. Areas of novelty, in terms of new regimens, new types of cancer suitable for Metronomic chemotherapy (mCHT) and the overview of current ongoing trials, along with a critical review of them, are also provided.

Abstract

Metronomic chemotherapy treatment (mCHT) refers to the chronic administration of low doses chemotherapy that can sustain prolonged, and active plasma levels of drugs, producing favorable tolerability and it is a new promising therapeutic approach in solid and in hematologic tumors. mCHT has not only a direct effect on tumor cells, but also an action on cell microenvironment, by inhibiting tumor angiogenesis, or promoting immune response and for these reasons can be considered a multi-target therapy itself. Here we review the state of the art of mCHT use in some classical tumour types, such as breast and no small cell lung cancer (NSCLC), see what is new regarding most recent data in different cancer types, such as glioblastoma (GBL) and acute myeloid leukemia (AML), and new drugs with potential metronomic administration. Finally, a look at the strategic use of mCHT in the context of health emergencies, or in low –and middle-income countries (LMICs), where access to adequate healthcare is often not easy, is mandatory, as we always need to bear in in mind that equity in care must be a compulsory part of our medical work and research.

Combining Angiogenesis Inhibitors with Radiation: Advances and Challenges in Cancer Treatment

BACKGROUND

Radiation therapy is a widely employed modality that is used to destroy cancer cells, but it also tends to induce changes in the tumor microenvironment and promote angiogenesis. Radiation, when used as a sole means of therapeutic approach to treat cancer, tends to trigger the angiogenic pathways, leading to the upregulation of several angiogenic growth factors such as VEGF, bFGF, PDGF and angiogenin. This uncontrolled angiogenesis leads to certain angiogenic disorders like vascular outgrowth and an increase in tumor progression that can pose a serious threat to patients.

OBJECTIVE

This review emphasizes on various components of the tumor microenvironment, angiogenic growth factors and biological effects of radiation on tumors in provoking the relapse. It also describes the angiogenic mechanisms that trigger the tumor relapse after radiation therapy and how angiogenesis inhibitors can help in overcoming this phenomenon. It gives an overview of various angiogenesis inhibitors in pre-clinical as well as in clinical trials.

CONCLUSION

The review focuses on the beneficial effects of the combinatorial therapeutic approach of anti-angiogenesis therapy and radiation in tumor management.

Insulin's actions on vascular tissues: Physiological effects and pathophysiological contributions to vascular complications of diabetes

Background

Insulin has been demonstrated to exert direct and indirect effects on vascular tissues. Its actions in vascular cells are mediated by two major pathways: the insulin receptor substrate 1/2-phosphoinositide-3 kinase/Akt (IRS1/2/PI3K/Akt) pathway and the Src/mitogen-activated protein kinase (MAPK) pathway, both of which contribute to the expression and distribution of metabolites, hormones, and cytokines.

Scope of review

In this review, we summarize the current understanding of insulin's physiological and pathophysiological actions and associated signaling pathways in vascular cells, mainly in endothelial cells (EC) and vascular smooth muscle cells (VSMC), and how these processes lead to selective insulin resistance. We also describe insulin's potential new signaling and biological effects derived from animal studies and cultured capillary and arterial EC, VSMC, and pericytes. We will not provide a detailed discussion of insulin's effects on the myocardium, insulin's structure, or its signaling pathways' various steps, since other articles in this issue discuss these areas in depth.

Major conclusions

Insulin mediates many important functions on vascular cells via its receptors and signaling cascades. Its direct actions on EC and VSMC are important for transporting and communicating nutrients, cytokines, hormones, and other signaling molecules. These vascular actions are also important for regulating systemic fuel metabolism and energetics. Inhibiting or enhancing these pathways leads to selective insulin resistance, exacerbating the development of endothelial dysfunction, atherosclerosis, restenosis, poor wound healing, and even myocardial dysfunction. Targeted therapies to improve selective insulin resistance in EC and VSMC are thus needed to specifically mitigate these pathological processes.

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Insulin's actions in vascular cells have a significant influence on systemic metabolism.

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Insulin exerts its vascular effects through its receptors and signaling cascades.

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Inhibition or enhancement of different insulin signaling leads to selective insulin resistance.

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Loss of insulin's actions causes endothelial dysfunction and vascular complications in diabetes.

Angiogenesis as a hallmark of solid tumors - clinical perspectives

BACKGROUND

Angiogenesis is a key and early step in tumorigenesis, and is known as a hallmark of solid tumors and a key promoter of tumor recurrence. Unlike normal tissue vessels, the architecture of the tumor vasculature is abnormal, being leaky, tortuous, fragile and blind-ended. Perivascular cells are either detached or absent, causing reduction of vascular integrity, an increase in vessel immaturity, incoherent perfusion, defective functionality and enhanced tumor dissemination and metastasis. The abnormal tumor vasculature along with the defective tumor vessel functionality finally causes bouts of hypoxia and acidity in the tumor microenvironment (TME), further reinvigorating tumor aggression. Interstitial hypertension or high interstitial fluid pressure (IFP) is an outcome of tumor hyper-permeability. High IFP can be a barrier for either effective delivery of anti-cancer drugs toward the TME or accumulation of drugs within the tumor area, thus promoting tumor resistance to therapy. Some tumors do, however, not undergo angiogenesis but instead undergo vessel co-option or vascular mimicry, thereby adding another layer of complexity to cancer development and therapy.

CONCLUSIONS

Combination of anti-angiogenesis therapy with chemotherapy and particularly with immune checkpoint inhibitors (ICIs) is a promising strategy for a number of advanced cancers. Among the various approaches for targeting tumor angiogenesis, vascular normalization is considered as the most desired method, which allows effective penetration of chemotherapeutics into the tumor area, thus being an appropriate adjuvant to other cancer modalities.