Targeting angiogenesis: progress with anti-VEGF treatment with large molecules

Targeting VEGF signaling for tumor microenvironment remodeling and metastasis inhibition: Therapeutic strategies and insights

The tumor microenvironment (TME) plays a pivotal role in cancer progression and metastasis, with vascular endothelial growth factor (VEGF) signaling serving as a key regulator of tumor angiogenesis and immune evasion. VEGF induces abnormal blood vessel formation, promoting tumor growth, immune suppression, and metastasis through epithelialmesenchymal transition (EMT). As a result, VEGF signaling has become a critical therapeutic target in cancer treatment. This review examines the molecular mechanisms driving VEGF-mediated tumor growth and angiogenesis, with a focus on the interaction between tumor and endothelial cells and the dual role of VEGF in fostering vascularization and immune suppression. Current anti-VEGF therapies, including monoclonal antibodies (e.g., bevacizumab) and tyrosine kinase inhibitors (TKIs), have demonstrated efficacy and have received FDA approval for various cancers; however, therapeutic resistance remains a significant challenge. Strategies to overcome resistance, such as novel VEGF inhibitors, vascular normalization approaches, and combination therapies with immune checkpoint inhibitors, have been explored. Additionally, future directions emphasize the need for personalized approaches to improve treatment efficacy and reduce metastasis. A comprehensive understanding of VEGF signaling in the TME may pave the way for more effective cancer therapies.

Blocking Tumoral Angiogenesis VEGF/VEGFR Pathway: Bevacizumab-20 Years of Therapeutic Success and Controversy

The "angiogenesis switch"-defined as the active process by which solid tumors develop their own circulation-plays an important role in both tumoral growth and propagation. As the malignant tumor grows and reaches a critical size, the metabolic needs as a function of an ever-increasing distance to the nearest emergent blood vessel, can no longer be covered by the microenvironment of the peritumoral tissue. Although a relatively discrete process, the "angiogenic switch" acts as a limiting stage of tumoral development present from the avascular hyperplasia phase to the vascularized neoplastic phase, providing support for tumor expansion and metastasis. Over time, research has focused on blocking the angiogenetic pathways (such as VEGF/VEGFR signaling axis) leading to the development of targeted therapeutic agents such as Bevacizumab. Objectives: We conducted a review of the molecular principles of tumoral angiogenesis and we tried to follow the history of Bevacizumab from its first approval for human usage 20 years ago to current days, focusing on the impact this agent had in solid tumor therapy. A comprehensive review of clinical trials pertaining to Bevacizumab (from the era of the preclinic trials leading to approval for human usage, to the more recent randomized trial focusing on combination targeted therapy) further details the role of this drug. We aimed to establish if this ancient drug continues to have a place in modern oncology. Conclusions: Bevacizumab, one of the first drugs targeting tumoral microenvironment, remains one of the most important oncologic agents blocking the VEGF/VEGFR angiogenic pathway. otherwise, history of 20 years marked by numerous controversies (ranging from methodological errors of clinical trials to withdrawal of approval for human usage in breast cancer patients, from discussions about severe side effects to resistance to therapy and limited efficacity), Bevacizumab continues to provide an optimal therapeutic option for many solid tumors that previously had little to no means of treatment, improving otherwise bleak outcomes. Even in the era of personalized precision oncology, Bevacizumab continues to be a key element in many therapeutic regimens both as monotherapy and in combination with newer targeted agents.

Pharmacological agents for treatment of proliferative vitreoretinopathy: A systematic review and network meta-analysis

We performed a comprehensive systematic review and network meta-analysis (NMA) to assess the efficacy of pharmacological agents for the treatment of proliferative vitreoretinopathy (PVR) following retinal detachment (RD) surgery. A systematic search was performed across PubMed, Scopus, Web of Science, and Embase. Randomized and non-randomized controlled trials and comparative observational studies evaluating the effect of pharmacological agents in a clinical setting were included. The primary outcome was retinal reattachment rate, and secondary outcomes were PVR recurrence, reoperation, intraocular pressure (IOP), epiretinal membrane (ERM), and macular edema. A total of 23 studies with 1749 eyes were included. Twelve different drugs or drug combinations were assessed. The NMA was performed for retinal reattachment, PVR recurrence, and reoperation rate outcomes. Among the pharmacological agents analyzed, adjunctive therapy with 13-cis-retinoic acid (13-cis-RA) demonstrated a statistically significant improvement in retinal reattachment rates (RR=1.36, 95 % CI: 1-1.84) and a reduction in reoperation rates (RR=0.23, 95 % CI: 0.07-0.69) compared to the control group, while none of the other drugs had statistically significant results. Additionally, adjunctive therapy did not yield significant improvements in IOP, ERM, or macular edema, except for a reduction in macular edema associated with dexamethasone in one study. This systematic review and NMA indicate that most pharmacological agents could not significantly improve retinal reattachment, reduce PVR recurrence, or lower reoperation rates following RD surgery. 13-cis-RA was the only drug that showed a significant impact on lowering retinal detachment and reoperation rates. Further high-quality clinical trials are warranted to confirm these findings.

miR-6760-5p suppresses neoangiogenesis by targeting Yes-associated protein 1 in patients with moyamoya disease undergoing indirect revascularization

OBJECTIVE

The aim of this research was to investigate the specific regulatory role of miR-6760-5p in angiogenesis in moyamoya disease.

METHODS

HUVECs were transfected with miR-6760-5p inhibitor and mimics fragments, then subjected to assays for cell proliferation, migration, and tube formation. Subsequently, downstream target genes of miR-6760-5p were predicted and the protein expression levels of these genes were evaluated. The presence of miR-6760-5p and YAP1 was verified by a dual luciferase reporter gene test, followed by an assessment of the effects of YAP1 and miR-6760-5p on the HUVECs.

RESULTS

Comparatively to the control group, increased expression of miR-6760-5p decreased cell growth, movement, and tube formation. YAP1 gene was discovered as a target controlled by miR-6760-5p, with subsequent investigation confirming YAP1 as a gene regulated by miR-6760-5p. Additionally, miR-6760-5p was found to counteract the angiogenesis-promoting effect of YAP1.

CONCLUSION

The results of this research suggest a possible link between the miR-6760-5p gene found in the cerebrospinal fluid of individuals with moyamoya disease and the process of vascularization in this particular condition. The findings indicate that miR-6760-5p may be a new molecular indicator and potential target for the diagnosis of moyamoya disease.

Prognostic significance of necrosis in ampullary carcinomas

BACKGROUND/AIMS

Necrosis is an important pathological feature that reflects high malignancy potential in tumors such as hepatocellular carcinoma and renal cell carcinoma. We aimed to elucidate the prognostic impact of necrosis in ampullary carcinomas.

MATERIALS AND METHODS

We reviewed 101 consecutive cases of ampullary carcinoma for tumor necrosis, types of necrosis, macroscopic and microscopic histopathological subtypes, lymphatic-vascular-perineural invasions, and other histopathological parameters.

RESULTS

Tumor necrosis was present in 19 (18.8%) cases and was identified as an independent poor prognostic indicator in multivariate survival analysis (p = 0.029).

CONCLUSION

The presence of necrosis in ampullary carcinomas is directly related to vascular and perineural invasion and is a poor prognostic indicator independent of tumor stage. Including the presence of necrosis in the pathology reports of ampullary carcinomas will facilitate risk stratification.

Bevacizumab-Based Therapies in Malignant Tumors-Real-World Data on Effectiveness, Safety, and Cost

Overall, it is estimated that more than 3,500,000 patients have received Bevacizumab as part of systemic oncologic treatment. Bevacizumab and its biosimilars are currently marketed in over 130 countries. Given the wide usage of Bevacizumab in current oncological practice, it is very important to compare the "real-world" results to those obtained in controlled clinical trials. This study aims to describe the clinical experience of using Bevacizumab in a large cohort of cancer patients in "non-controlled real-world" conditions with regard to effectiveness, safety, and cost of therapy.

METHODS

For this purpose, we conducted an open, observational, retrospective study involving all patients treated for solid malignant tumors in the Bucharest Institute of Oncology with "Prof. Dr. Al. Trestioreanu" with Bevacizumab-based systemic therapy, between 2017 and 2021.

RESULTS

The study consisted of 657 treatment episodes in 625 patients (F/B = 1.62/1, with a median age of 57.6 years) which were treated for malignant tumors (majority colorectal, non-small cell lung, ovarian, and breast cancer). First-line treatment was administered in 229 patients, and the rest received Bevacizumab as second or subsequent lines of treatment. The overall response rate to Bevacizumab-based therapies was around 60-65% across all indication except for subsequent treatment lines in colorectal and ovarian cancers, where lower values were recorded (27.1%, and 31.5% respectively). Median PFS for the entire cohort was 8.2 months (95% CI 6.8-9.6), and the median OS was 13.2 months (95% CI 11.5-14.9). Usual bevacizumab-related toxicities were observed, including bleeding, hypertension, wound-healing complications, gastrointestinal perforation, other types of fistulas, septic complications, and thromboembolic events. Although the clinical benefits are undeniable, the addition of Bevacizumab to standard chemotherapy increased the overall treatment cost by 213%.

CONCLUSIONS

Bevacizumab remains a high-cost therapy, but it can add to clinical benefits (like overall survival, progression-free survival, and response rate) when used in conjunction with standard chemotherapy. Similar results as those presented in various controlled trials are observable even on unselected cohorts of patients in the uncontrolled conditions of "real-world" oncological practice. Off-label usage is encountered in clinical practice, and this aspect should be monitored given the potential adverse effects of the therapy.

Small molecule inhibitors of the VEGF and tyrosine kinase for the treatment of cervical cancer

Cervical cancer accounts for most deaths due to cancer in women, majorly in developing nations. The culprit behind this disease is the human papillomavirus (HPV) which accounts for more than 90% of cervical cancer cases. The viral strains produce proteins that favor the knocking down of the apoptosis process and continuous growth of cells in the cervix leading to tumor growth. Proangiogenic growth factors, such as fibroblast growth factor (FGF), vascular endothelial growth factor (VEGF), angiopoietins, and other endothelial growth factors (EGF), are secreted by tumor cells and the surrounding microenvironment, which further advances the development of cancer. The extracellular domain of receptor tyrosine kinases is employed by ligands (like VEGF and EGF) to engage and activate them by inducing receptor dimerization, which facilitates the cascade impact of these factors. The tyrosine kinase domains of each receptor autophosphorylate each other, activating the receptor and initiating signaling cascades that promote angiogenesis, migration, proliferation, and survival of endothelial cells. Cancer cells benefit from its modified signaling pathways, which cause oncogenic activation. Upon early cervical cancer detection, the second-line therapy strategy involves blocking the signaling pathways with VEGF and small molecule tyrosine kinase inhibitors (TKIs). This review paper highlights the genesis of cervical cancer and combating it using VEGF and tyrosine kinase inhibitors by delving into the details of the currently available inhibitors. Further, we have discussed the inhibitor molecules that are currently in various phases of clinical trials. This paper will surely enhance the understanding of cervical cancer and its treatment approaches and what further interventions can be done to alleviate the disease currently serving as a major health burden in the developing world.

Circulating VEGF and inflammatory bowel disease: a bidirectional mendelian randomization

Introduction: Prior observational studies have suggested an association between circulating vascular endothelial growth factor (VEGF) levels and inflammatory bowel disease (IBD). This study sought to demonstrate the directionality of the association between circulating VEGF and particular forms of IBD as well as if there is a causal relationship between them. Methods: We collected summary data from relevant genome-wide association studies (GWASs) to assess the validity of causality, and a two-sample bidirectional Mendelian randomization (MR) study and sensitivity testing were performed to assess the causal relationship between circulating VEGF and IBD risk, including Crohn's disease and ulcerative colitis. Results: Our findings revealed a direct causal link between circulating VEGF and Crohn's disease (b 0.195, se 0.078, p < 0.013). However, neither circulating VEGF nor ulcerative colitis were shown to be causally linked (p > 0.025), nor was there proof of a reverse causal relationship from IBD to VEGF. Discussion: In conclusion, circulating VEGF shows a cause-and-effect relationship with Crohn's disease.

A Comprehensive Review on Nanoparticles as a Targeted Delivery System for the Treatment of Lung Cancer

The second most common type of cancer is lung cancer, impacting the human population. Lung cancer is treated with a number of surgical and non-surgical therapies, including radiation, chemotherapy, and photodynamic treatment. However, the bulk of these procedures are costly, difficult, and hostile to patients. Chemotherapy is distinguished by inadequate tumour targeting, low drug solubility, and insufficient drug transport to the tumour site. In order to deal with the issues related to chemotherapy, extensive efforts are underway to develop and investigate various types of nanoparticles, both organic and inorganic, for the treatment of lung cancer. The subject of this review is the advancements in research pertaining to active targeted lung cancer nano-drug delivery systems treatment, with a specific emphasis on receptors or targets. The findings of this study are expected to assist biomedical researchers in utilizing nanoparticles (NPs) as innovative tools for lung cancer treatment, offering new methods for delivering drugs and reliable solid ligands.

Decoding the molecular mechanism of stypoldione against breast cancer through network pharmacology and experimental validation

Breast cancer is the primary factor contributing to female mortality worldwide. The incidence has overtaken lung cancer. It is the most difficult illness due to its heterogeneity and is made up of several subtypes, including Luminal A and B, basal-like, Her-2 overexpressed and TNBC. Amongst different breast carcinoma subtypes, TNBC is the most deadly breast cancer subtype. The hostile nature of TNBC is mainly attributed to its lack of three hormonal receptors and hence lack of targeted therapy. Furthermore, the current diagnostic options like radiotherapy, surgery and chemotherapy render unsuccessful due to recurrence, treatment side effects and drug resistance. The majority of anticancer drugs come from natural sources or is developed from them, making nature a significant source of many medicines. Marine-based constituents such as nucleotides, proteins, peptides, and amides are receiving a lot of interest in the field of cancer treatment due to their bioactive properties. The role of stypoldione in this study as a prospective treatment for breast carcinoma was examined, and we sought to comprehend the molecular means/pathways this chemical employs in breast carcinoma. The most promising possibility for an anti-cancer treatment is stypoldione, a marine chemical produced from the brown alga Stypopodium zonale. We investigated stypoldione's mode of action in breast cancer using the network pharmacology method, and we confirmed our research by using a number of computational tools, including UALCAN, cBioportal, TIMER, docking, and simulation. The findings revealed 92 common targets between the chemical and breast cancer target network. Additionally, we found that stypoldione targets a number of unregulated genes in breast cancer, including: ESR1, HSP90AA1, CXCL8, PTGS2, APP, MDM2, JAK2, KDR, LCK, GRM5, MAPK14, KIT, and several signaling pathways such as FOXO signaling pathway, VEGF pathway, calcium signaling pathway, MAPK/ERK pathway and Neuroactive ligand-receptor interaction. The examined medication demonstrated a strong affinity for the major targets, according to a docking analysis. The best hit compound produced a stable protein-ligand pair, as predicted by molecular dynamics simulations. Our results are supported by the fact that when in-vitro assays were done on melanoma using stypoldione compound it was found that its mechanisms of action involved the PI3K/mTOR/Akt and NF-kB pathways. This study was set out to inspect the possible value of stypoldione as a breast cancer cure and to get a deeper understanding of the molecular mechanisms by which this drug acts on breast cancer.

A Clinical Viewpoint on the Use of Targeted Therapy in Advanced Gastric Cancer

The development of therapies for advanced gastric cancer (GC) has made significant progress over the past few years. The identification of new molecules and molecular targets is expanding our understanding of the disease's intricate nature. The end of the classical oncology era, which relied on well-studied chemotherapeutic agents, is giving rise to novel and unexplored challenges, which will cause a significant transformation of the current oncological knowledge in the next few years. The integration of established clinically effective regimens in additional studies will be crucial in managing these innovative aspects of GC. This study aims to present an in-depth and comprehensive review of the clinical advancements in targeted therapy and immunotherapy for advanced GC.

Research Progress on Mechanism and Management of Adverse Drug Reactions of Anlotinib

Anti-angiogenesis therapy plays a vital role in the treatment of tumors, with anlotinib as its representative targeted drug. Anlotinib is a novel oral tyrosine kinase inhibitor (TKI) with inhibitory effects on tumor growth tumor angiogenesis. In Phase III clinical trials, anlotinib demonstrated better overall survival and progression-free survival than placebo in patients with advanced non-small cell lung cancer (NSCLC), and was approved for the first time as a third-line treatment for refractory advanced NSCLC. Going far beyond that, anlotinib has shown encouraging results in a variety of malignancies, including medullary thyroid carcinoma, renal cell carcinoma, gastric cancer and esophageal squamous cell carcinoma. Nevertheless, anlotinib has been subject to some controversy in terms of adverse events due to its widespread use. In this review, the mechanism of action, pharmacokinetic characteristics, adverse reactions in clinical use and management of anlotinib were summarized.

Solanum nigrum Linn.: Advances in anti-cancer activity and mechanism in digestive system tumors

Cancer has currently become a serious public health issue in many countries worldwide, and tumors of the digestive system have attracted an increasing number of researchers' due to their numerous types, high proportion and wide area of occurrence. While tumors of the digestive system suffer from high mortality rates, leading to untimely diagnosis and a poor prognosis, making it necessary to update current treatment approaches such as surgery, radiation therapy, and chemotherapy. This highlights the importance of exploring novel therapeutic ideas and targets. Traditional Chinese medicine has a long history of clinical use due to its low toxicity and multi-factor targeting of multiple pathways. As a kind of traditional Chinese herb, S. nigrum Linn. is highly regarded for its proven antitumor activity. The aim of this study was to comprehensively recapitulate and analyze the anti-cancer effects and molecular mechanisms of treatment of gastrointestinal tumors with S. nigrum Linn. extracts and related compounds, including classical signaling pathways mediated by them as well as noncoding RNA pathways associated with tumor suppression. Components that have been found to be responsible for the anti-cancer activity of S. nigrum Linn. include solanine, solasonine, solamargine, a-L-rhhamnopyranose, uttroside B, degalactotigonin, glycoprotein, and other compounds. The underlying mechanisms of anti-cancer activity reflected in this study include apoptosis, cell cycle arrest, autophagy, anti-angiogenesis, suppression of metastasis and invasion, immune escape, and increased sensitivity to radiotherapy. S. nigrum Linn. has great potential in the treatment of tumors of the digestive system, and through further clinical trials and pharmacological mechanisms it has the potential to become a uniform and standardized anti-tumor drug.

Molecularly Imprinted Nanomedicine for Anti-angiogenic Cancer Therapy via Blocking Vascular Endothelial Growth Factor Signaling

The VEGF-VEGFR2 (VEGF = vascular endothelial growth factor) signaling has been a promising target in cancer therapy. However, because conventional anti-angiogenic therapeutics suffer from drawbacks, particularly severe side effects, novel anti-angiogenic strategies are much needed. Herein, we report the rational engineering of VEGF-targeted molecularly imprinted polymer nanoparticles (nanoMIP) for anti-angiogenic cancer therapy. The anti-VEGF nanomedicine was prepared via a state-of-the-art molecular imprinting approach using the N-terminal epitope of VEGF as the template. The nanoMIP could target the two major pro-angiogenic isoforms (VEGF165 and VEGF121) with high affinity and thereby effectively block the VEGF-VEGFR2 signaling, yielding a potent anti-angiogenic effect of "killing two birds with one stone". In vivo experiments demonstrated that the anti-VEGF nanoMIP effectively suppressed tumor growth via anti-angiogenesis in a xenograft model of human colon carcinoma without apparent side effects. Thus, this study not only proposes an unprecedented anti-angiogenic strategy for cancer therapy but also provides a new paradigm for the rational development of MIPs-based "drug-free" nanomedicines.

Novel heavily fucosylated glycans as a promising therapeutic target in colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is highly prevalent and lethal globally, and its prognosis remains unsatisfactory. Drug resistance is regarded as the main cause of treatment failure leading to tumor recurrence and metastasis. The overexpression of fucosylated epitopes, which are usually modifications of glycoproteins, was reported to occur in various epithelial cancers. However, the effects of treatments that target these antigens in colorectal cancer remain unclear.

METHODS

This study investigated the expression of heavily fucosylated glycans (HFGs) in 30 clinical samples from patients with CRC and other normal human tissues. The complement-dependent cytotoxicity was explored in vitro through treatment with anti-HFG monoclonal antibody (mAb) alone or in combination with chemotherapeutic agents. In vivo inhibitory effects were also examined using a xenograft mouse model.

RESULTS

Immunohistochemistry staining and western blotting revealed that HFG expression was higher in human colorectal cancer tissues than in normal tissues. In DLD-1 and SW1116 cells, which overexpress fucosylated epitopes, anti-HFG mAb produced observable cytotoxic effects, especially when it was combined with chemotherapeutic agents. The xenograft model also demonstrated that anti-HFG mAb had potent and dose-dependent inhibitory effects on colorectal tumor growth.

CONCLUSIONS

As a novel cancer antigen, HFGs are a promising treatment target, and the implementation of anti-HFG mAb treatment for CRC warrants further investigation.

Production of a biosimilar version of aflibercept to improve VEGF blocker cytotoxicity on endothelial cells

This project aimed to produce a biosimilar version of aflibercept (AFL) and evaluate the effect of the co-treatment of AFL with other vascular endothelial growth factor (VEGF) blocker drugs. For this purpose, the optimized gene was inserted into the pCHO1.0 plasmid and transfected into the CHO-S cell line. The final concentration of biosimilar-AFL for the selected clone was 782 mg/L. Results revealed that the inhibition potential of the biosimilar-AFL on HUVEC cells was significant at 10 and 100 nM concentrations and in a dose-dependent manner. Furthermore, co-treatment of biosimilar-AFL with Everolimus (EVR), Lenvatinib (LEN), and Sorafenib (SOR) could reduce HUVEC cell viability/proliferation, more than when used alone. When LEN and SOR were co-treated with biosimilar-AFL, their cytotoxicity increased 10-fold. The most and least efficient combination was seen when biosimilar-AFL combined with LEN and EVR, respectively. Finally, biosimilar-AFL may improve the efficiency of LEN, EVR, and SOR in reducing the VEGF effect on endothelial cells.

Bone morphogenetic protein signaling is a possible therapeutic target in gynecologic cancer

Bone morphogenetic proteins (BMPs) belong to the transforming growth factor β (TGFβ) superfamily. BMPs play crucial roles in embryogenesis and bone remodeling. Recently, BMP signaling has been found to have diverse effects on different types of tumors. In this review, we summarized the effects of BMP signaling on gynecologic cancer. BMP signaling has tumor-promoting effects on ovarian cancer (OC) and endometrial cancer (EC), whereas it has tumor-suppressing effects on uterine cervical cancer (UCC). Interestingly, EC has frequent gain-of-function mutations in ACVR1, encoding one of the type I BMP receptors, which are also observed in fibrodysplasia ossificans progressiva and diffuse intrinsic pontine glioma. Little is known about the relationship between BMP signaling and other gynecologic cancers. Tumor-promoting effects of BMP signaling in OC and EC are dependent on the promotion of cancer stemness and epithelial-mesenchymal transition (EMT). In accordance, BMP receptor kinase inhibitors suppress the cell growth and migration of OC and EC. Since both cancer stemness and EMT are associated with chemoresistance, BMP signaling activation might also be an important mechanism by which OC and EC patients acquire chemoresistance. Therefore, BMP inhibitors are promising for OC and EC patients even if they become resistant to standard chemotherapy. In contrast, BMP signaling inhibits UCC growth in vitro. However, the in vivo effects of BMP signaling have not been elucidated in UCC. In conclusion, BMP signaling has a variety of functions, depending on the types of gynecologic cancer. Therefore, targeting BMP signaling should improve the treatment of patients with gynecologic cancer.

Targeted Therapies for Hepatocellular Carcinoma Treatment: A New Era Ahead-A Systematic Review

Hepatocellular carcinoma (HCC) remains one of the most common malignancies and the third cause of cancer-related death worldwide, with surgery being the best prognostic tool. Among the well-known causative factors of HCC are chronic liver virus infections, chronic virus hepatitis B (HBV) and chronic hepatitis virus C (HCV), aflatoxins, tobacco consumption, and non-alcoholic liver disease (NAFLD). There is a need for the development of efficient molecular markers and alternative therapeutic targets of great significance. In this review, we describe the general characteristics of HCC and present a variety of targeted therapies that resulted in progress in HCC therapy.

Circulating vascular endothelial growth factor and cancer risk: A bidirectional mendelian randomization

In observational studies, circulating vascular endothelial growth factor (VEGF) has been reported to be associated with certain types of cancer. The purpose of this study was to verify whether there is a causal relationship between circulating VEGF and different types of cancer and the direction of the causal relationship. Summary statistical data were obtained from the corresponding genome-wide association studies (GWASs) to investigate the causal relationship between circulating VEGF and the risk of several cancers, including breast cancer, ovarian cancer, lung cancer, colorectal cancer, anus and anal canal cancer, prostate cancer, esophageal cancer, kidney cancer, bladder cancer, thyroid cancer, malignant neoplasm of the brain and malignant neoplasm of the liver and intrahepatic bile ducts. A two-sample bidirectional Mendelian randomization (MR) analysis and sensitivity tests were used to evaluate the validity of causality. A causal relationship was detected between circulating VEGF and colorectal cancer (OR 1.21, 95% CI 1.11–1.32, p < 0.000) and colon adenocarcinoma (OR 1.245, 95% CI 1.10–1.412, p < 0.000). Suggestive evidence of association was detected in VEGF on malignant neoplasms of the rectum (OR 1.16, 95% CI 1.00–1.34, p = 0.049). No causal relationship was found between circulating VEGF and other types of cancer, nor was there a reverse causal relationship from tumors to VEGF (p > 0.05). Circulating VEGF has a causal relationship with specific types of cancer. Our findings highlight and confirm the importance of circulating VEGF in the prevention and treatment of colorectal cancer.

Apatinib for recurrent/progressive glioblastoma multiforme: A salvage option

Purpose: The recurrent/progressive glioblastoma multiforme (GBM) carries a dismal prognosis and the definitive treatment strategy has not yet been established. This study aimed to assess the efficacy and safety of apatinib in recurrent/progressive GBM patients.

Materials and methods: The clinical data of 19 recurrent/progressive GBM patients who received apatinib treatment from November 2015 to December 2019 at Sun Yat-sen University Cancer Center were collected retrospectively in this study. Objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), overall survival (OS), and treatment-related adverse events (AEs) were reviewed and assessed.

Results: The overall ORR was 52.6%, and the DCR was 73.7%. Median PFS and OS were 5.1 and 10.4 months, respectively. The 6-month PFS and OS rates were 38.9% and 68.4%, respectively. The 12-month PFS and OS rates were 16.7% and 36.8%, respectively. The treatment-related toxicities were generally well-tolerated. The most common grade 3/4 AEs were hand-foot syndrome (36.8%) and hypertension (21.1%).

Conclusion: Our study showed that apatinib therapy provided a better salvaging option for recurrent/progressive GBM patients and the toxicity was manageable.

The Vascular Endothelium and Coagulation: Homeostasis, Disease, and Treatment, with a Focus on the Von Willebrand Factor and Factors VIII and V

The vascular endothelium has several important functions, including hemostasis. The homeostasis of hemostasis is based on a fine balance between procoagulant and anticoagulant proteins and between fibrinolytic and antifibrinolytic ones. Coagulopathies are characterized by a mutation-induced alteration of the function of certain coagulation factors or by a disturbed balance between the mechanisms responsible for regulating coagulation. Homeostatic therapies consist in replacement and nonreplacement treatments or in the administration of antifibrinolytic agents. Rebalancing products reestablish hemostasis by inhibiting natural anticoagulant pathways. These agents include monoclonal antibodies, such as concizumab and marstacimab, which target the tissue factor pathway inhibitor; interfering RNA therapies, such as fitusiran, which targets antithrombin III; and protease inhibitors, such as serpinPC, which targets active protein C. In cases of thrombophilia (deficiency of protein C, protein S, or factor V Leiden), treatment may consist in direct oral anticoagulants, replacement therapy (plasma or recombinant ADAMTS13) in cases of a congenital deficiency of ADAMTS13, or immunomodulators (prednisone) if the thrombophilia is autoimmune. Monoclonal-antibody-based anti-vWF immunotherapy (caplacizumab) is used in the context of severe thrombophilia, regardless of the cause of the disorder. In cases of disseminated intravascular coagulation, the treatment of choice consists in administration of antifibrinolytics, all-trans-retinoic acid, and recombinant soluble human thrombomodulin.

Safety, recommended dose, efficacy and immune correlates for nintedanib in combination with pembrolizumab in patients with advanced cancers

Background

We aimed to determine the safety and efficacy of nintedanib, an oral anti-angiogenic tyrosine kinase inhibitor, in combination with pembrolizumab, an anti-PD1 immunotherapy, in patients with advanced solid tumors (PEMBIB trial; NCT02856425).

Methods

In this monocentric phase Ib dose escalation cohort, we evaluated escalating doses of nintedanib (Dose level 1 (DL1) = 150 mg bid [bis in die, as twice a day]; DL2 = 200 mg bid, oral delivery) in combination with pembrolizumab (200 mg Q3W, IV). Patients received a 1-week lead-in dose of nintedanib monotherapy prior starting pembrolizumab. The primary objective was to establish the maximum tolerated dose (MTD) of the combination based on dose limiting toxicity (DLT) occurrence during the first 4 weeks. Secondary objectives were to assess the anti-tumor efficacy and to identify the associated immune and angiogenic parameters in order to establish the recommended nintedanib dose for expansion cohorts. Flow cytometry (FC), Immuno-Histo-Chemistry (IHC) and electrochemiluminescence multi-arrays were prospectively performed on baseline & on-treatment tumor and blood samples to identify immune correlates of efficacy.

Results

A total of 12/13 patients enrolled were evaluable for DLT (1 patient withdrew consent prior receiving pembrolizumab). Three patients at 200 mg bid experienced a DLT (grade 3 liver enzymes increase). Four patients developed grade 1–2 immune related adverse events (irAE). Eight patients died because of cancer progression. Median follow-up was 23.7 months (95%CI: 5.55–40.5). Three patients developed a partial response (PR) (ORR = 25%) and five patients (42%) had durable clinical benefit (DCB), defined as PR or stable disease (SD) ≥ 6 months. At baseline, patients with DCB had higher plasma levels of Tie2, CXCL10, CCL22 and circulating CD4⁺ PD1⁺ OX40⁺ T cells than patients without DCB. Patients with DCB presented also with more DC-LAMP⁺ dendritic cells, CD3⁺ T cells and FOXP3⁺ Tregs in baseline tumor biopsies. For DCB patients, the nintedanib lead-in monotherapy resulted in higher blood CCL3, Tregs and CCR4⁺ CXCR3⁺ CXCR5⁻ memory CD4 T cells. After the first pembrolizumab infusion, patients with DCB showed lower IL-6, IL-8, IL-27 plasma levels.

Conclusion

Nintedanib 150 mg bid is the recommended dose for combination with pembrolizumab and is currently investigated in multiple expansion cohorts. Early tumoral and circulating immune factors were associated with cancer outcome under nintedanib & pembrolizumab therapy.

Trial registration

ClinicalTrials.gov, NCT02856425. Registered August 4, 2016 — Prospectively registered.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-022-02423-0.

Glycometabolic reprogramming-mediated proangiogenic phenotype enhancement of cancer-associated fibroblasts in oral squamous cell carcinoma: role of PGC-1α/PFKFB3 axis

BACKGROUND

Angiogenesis is a key rate-limiting step in the process of tumour progression. Cancer-associated fibroblasts (CAFs), the most abundant component OSCC stroma, play important roles in pro-angiogenesis. Recently, the stroma "reverse Warburg effect" was proposed, and PFKFB3 has been brought to the forefront as a metabolic enzyme regulating glycometabolism. However, it remains unclear whether glycometabolism reprogramming is involved in promoting the angiogenesis of CAFs.

METHODS

CAFs and paracancerous fibroblasts (PFs) were isolated from OSCC and adjacent tissues. We detected the pro-angiogenesis and glycometabolism phenotype of three pairs of fibroblasts. Targeted blockage of PFKFB3 or activation of PGC-1α signal was used to investigate the effect of glycolysis on regulating angiogenesis of CAFs in vitro and vivo.

RESULTS

CAFs exhibited metabolic reprogramming and enhanced proangiogenic phenotype compared with PFs. Inhibition of PFKFB3-dependent glycolysis impaired proangiogenic factors (VEGF-A, PDGF-C and MMP9) expression in CAFs. Furthermore, CAFs proangiogenic phenotype was regulated by glycometabolism through the PGC-1α/PFKFB3 axis. Consistently, PGC-1α overexpression or PFKFB3 knockdown in CAFs slowed down tumour development by reducing tumour angiogenesis in the xenograft model.

CONCLUSION

CAFs of OSCC are characterised with glycometabolic reprogramming and enhanced proangiogenic phenotypes. Our findings suggest that activating PGC-1α signalling impairs proangiogenic phenotype of CAFs by blocking PFKFB3-driven glycolysis.

CircRNAs: promising factors for regulating angiogenesis in colorectal cancer

Colorectal cancer (CRC) is one of the most common cancers in the world. The incidence rate of cancer is high. The overall response to traditional treatment methods such as surgery, radiotherapy, and chemotherapy is not very satisfactory. Therefore, finding new therapeutic targets is very important for improving CRC treatment. In recent reports, the role of circRNAs in regulating colorectal angiogenesis has been gradually revealed. CircRNAs can indirectly act on angiogenesis pathways and regulate the expression of growth factors such as vascular endothelial growth factor (VEGF). CircRNAs are endogenous noncoding RNAs formed by pre-mRNAs through exon circular splicing. The covalent closed-loop structure makes these RNAs highly conserved and stable. CircRNAs have been found in human plasma, serum, urine, and other body fluids. Their highly conserved characteristics play important roles in many biological activities. CircRNAs can participate in the progression of many diseases by sponging miRNAs, interacting with proteins, and regulating transcription. Angiogenesis can provide nutrients and oxygen for tumour proliferation and metastasis. Angiogenesis is an important sign of the formation of the tumour microenvironment. Here, we will summarize the role of the latest circRNAs in the mechanism of angiogenesis in CRC and provide potential therapeutic targets for clinical treatment.

Immunotherapy Associated Neurotoxicity in Pediatric Oncology

Novel immunotherapies are increasingly being employed in pediatric oncology, both in the upfront and relapsed/refractory settings. Through various mechanisms of action, engagement and activation of the immune system can cause both generalized and disease site-specific inflammation, leading to immune-related adverse events (irAEs). One of the most worrisome irAEs is that of neurotoxicity. This can present as a large spectrum of neurological toxicities, including confusion, aphasia, neuropathies, seizures, and/or death, with variable onset and severity. Earlier identification and treatment, generally with corticosteroids, remains the mainstay of neurotoxicity management to optimize patient outcomes. The pathophysiology of neurotoxicity varies across the different therapeutic strategies and remains to be elucidated in most cases. Furthermore, little is known about long-term neurologic sequelae. This review will focus on neurotoxicity seen with the most common immunotherapies used in pediatric oncology, including CAR T cell therapy, alternative forms of adoptive cell therapy, antibody therapies, immune checkpoint inhibitors, and tumor vaccines. Herein we will discuss the incidence, pathophysiology, symptomatology, diagnosis, and management strategies currently being utilized for immunotherapy-associated neurotoxicity with a focus on pediatric specific considerations.

Targeting Ocular Drug Delivery: An Examination of Local Anatomy and Current Approaches

Ocular drug delivery remains the focus of much modern research. Primary routes of administration include the surface, the intravitreal space, the subretinal space, and the subconjunctival space, each with its own series of unique challenges, limitations, and advantages. Each of these approaches requires careful consideration of the local anatomy, physical barriers, and key cells as well as the interface between the anatomy and the drug or drug system being delivered. While least invasive, the topical route poses a challenge with the many physical barriers that prevent drug penetration into the eye; while injection into the intravitreal, subretinal, and subconjunctival spaces are direct and targeted but limited due to the many internal clearance mechanisms and potential for damage to the eye. Polymeric-based, sustained-release drug delivery systems have been identified as a potential solution to many of these challenges; however, the design and successful implementation of a sustained-release system that is well-tolerated, bioactive, biocompatible, and degradable remains, in many cases, only in the early stages. The drugs and biomaterials in question also require special attention as small chemical changes could result in vastly different outcomes. This paper explores the anatomy and key cells of these four primary drug delivery routes as well as the interface between drug and drug delivery systems and the anatomy, reviewing the recent developments and current state of research in each area. Finally, this paper also examines the frequently used drugs and biomaterials found in ocular drug delivery and summarizes the primary interactions observed.

A radiologist’s guide to novel anticancer therapies in the era of precision medicine

Novel anticancer agents have replaced conventional chemotherapy as first line agents for many cancers, with continued new and expanding indications. Small molecule inhibitors act on cell surface or intracellular targets and prevent the downstream signaling that would otherwise permit tumor growth and spread. Anticancer antibodies can be directed against growth factors or may be immunotherapeutic agents. The latter act by inhibiting mechanisms that cancer cells use to evade the immune system. Hormonal agents act by decreasing levels of hormones that are necessary for the growth of certain cancer cells. Cancer therapy protocols often include novel anticancer agents and conventional chemotherapy used successively or in combination, in order to maximize survival and minimize morbidity. A working knowledge of anti-cancer drug classification will aid the radiologist in assessing response on imaging.

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Novel anticancer agents include small molecule inhibitors, antibodies and hormones.

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These agents are predominantly cytostatic and inhibit factors that provide a survival advantage to tumor cells.

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Modern cancer therapy employs a combination of novel anticancer agents and conventional chemotherapy.

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It is essential for radiologists to have a broad understanding of these agents and their mechanisms of action.

A Gene-Based Machine Learning Classifier Associated to the Colorectal Adenoma-Carcinoma Sequence

Colorectal cancer (CRC) carcinogenesis is generally the result of the sequential mutation and deletion of various genes; this is known as the normal mucosa–adenoma–carcinoma sequence. The aim of this study was to develop a predictor-classifier during the “adenoma-carcinoma” sequence using microarray gene expression profiles of primary CRC, adenoma, and normal colon epithelial tissues. Four gene expression profiles from the Gene Expression Omnibus database, containing 465 samples (105 normal, 155 adenoma, and 205 CRC), were preprocessed to identify differentially expressed genes (DEGs) between adenoma tissue and primary CRC. The feature selection procedure, using the sequential Boruta algorithm and Stepwise Regression, determined 56 highly important genes. K-Means methods showed that, using the selected 56 DEGs, the three groups were clearly separate. The classification was performed with machine learning algorithms such as Linear Model (LM), Random Forest (RF), k-Nearest Neighbors (k-NN), and Artificial Neural Network (ANN). The best classification method in terms of accuracy (88.06 ± 0.70) and AUC (92.04 ± 0.47) was k-NN. To confirm the relevance of the predictive models, we applied the four models on a validation cohort: the k-NN model remained the best model in terms of performance, with 91.11% accuracy. Among the 56 DEGs, we identified 17 genes with an ascending or descending trend through the normal mucosa–adenoma–carcinoma sequence. Moreover, using the survival information of the TCGA database, we selected six DEGs related to patient prognosis (SCARA5, PKIB, CWH43, TEX11, METTL7A, and VEGFA). The six-gene-based classifier described in the current study could be used as a potential biomarker for the early diagnosis of CRC.

Dual sEH/COX-2 Inhibition Using PTUPB-A Promising Approach to Antiangiogenesis-Induced Nephrotoxicity

Kidney injury from antiangiogenic chemotherapy is a significant clinical challenge, and we currently lack the ability to effectively treat it with pharmacological agents. Thus, we set out to investigate whether simultaneous soluble epoxide hydrolase (sEH) and cyclooxygenase-2 (COX-2) inhibition using a dual sEH/COX-2 inhibitor PTUPB could be an effective strategy for treating antiangiogenic therapy-induced kidney damage. We used a multikinase inhibitor, sorafenib, which is known to cause serious renal side effects. The drug was administered to male Sprague-Dawley rats that were on a high-salt diet. Sorafenib was administered over the course of 56 days. The study included three experimental groups; 1) control group (naïve rats), 2) sorafenib group [rats treated with sorafenib only (20 mg/kg/day p.o.)], and 3) sorafenib + PTUPB group (rats treated with sorafenib only for the initial 28 days and subsequently coadministered PTUPB (10 mg/kg/day i.p.) from days 28 through 56). Blood pressure was measured every 2 weeks. After 28 days, sorafenib-treated rats developed hypertension (161 ± 4 mmHg). Over the remainder of the study, sorafenib treatment resulted in a further elevation in blood pressure through day 56 (200 ± 7 mmHg). PTUPB treatment attenuated the sorafenib-induced blood pressure elevation and by day 56, blood pressure was 159 ± 4 mmHg. Urine was collected every 2 weeks for biochemical analysis. After 28 days, sorafenib rats developed pronounced proteinuria (9.7 ± 0.2 P/C), which intensified significantly (35.8 ± 3.5 P/C) by the end of day 56 compared with control (2.6 ± 0.4 P/C). PTUPB mitigated sorafenib-induced proteinuria, and by day 56, it reduced proteinuria by 73%. Plasma and kidney tissues were collected on day 56. Kidney histopathology revealed intratubular cast formation, interstitial fibrosis, glomerular injury, and glomerular nephrin loss at day 56 in sorafenib-treated rats. PTUPB treatment reduced histological features by 30%-70% compared with the sorafenib-treated group and restored glomerular nephrin levels. Furthermore, PTUPB also acted on the glomerular permeability barrier by decreasing angiotensin-II-induced glomerular permeability to albumin. Finally, PTUPB improved in vitro the viability of human mesangial cells. Collectively, our data demonstrate the potential of using PTUPB or dual sEH/COX-2 inhibition as a therapeutic strategy against sorafenib-induced glomerular nephrotoxicity.

Anti-angiogenic Properties of Bevacizumab Improve Respiratory System Inflammation in Ovalbumin-Induced Rat Model of Asthma

Studies on the bronchial vascular bed have revealed that the number of blood vessels in the lamina propria and under the mucosa of the lung tissue increases in patients suffering from mild to severe asthma. Thus, in this study, a new strategy was employed in respiratory system disorders by angiogenesis inhibition in an ovalbumin (OVA)-induced rat model of asthma. Twenty-one male Wistar albino rats, 8 weeks old, were randomly divided into three groups (n = 7 in each group), including (1) control group, (2) OVA-treated group, and (3) OVA + Bmab (bevacizumab drug). On days 1 and 8, 1 mg of OVA and aluminum hydroxide in sterile phosphate-buffered saline (PBS) were intraperitoneally injected to rats in groups 2 and 3. The control group was only subject to intraperitoneal injection of saline on days 1 and 8. One week after the last injection, the rats (groups 2 and 3) were exposed to OVA inhalation for 30 min at 2-day intervals from days 15 to 25. After sensitization and challenge with OVA, the OVA + Bmab group (group 3) were treated with a 5 mg/kg bevacizumab drug. Genes and protein expression of IL-1β and TNF-α and the expression of vascular endothelial growth factor (VEGF) protein were assessed by real-time PCR and immunohistochemistry respectively, in lung tissue. OVA exposure increased mucosal secretion and inflammatory cell populations in lung tissue and OVA-specific IgE level in serum. Also, VEGF and cytokine factor expression were significantly elevated in the OVA-induced asthma model (p ≤ 0.05). However, rats in OVA + Bmab group showed significantly a decrease in VEGF and IL-1β and TNF-α genes as well as proteins (p ≤ 0.05). The results showed that bevacizumab efficiently diminished bronchial inflammation via downregulation of VEGF expression, followed by inflammatory cells population and cytokines reduction. Angiogenesis inhibition in rats with induced asthma not only suppresses the inflammatory process through blocking VEGF expression but also inhibits the development of new blood vessels and progressing asthmatic attacks.

Furanone-functionalized benzothiazole derivatives: synthesis, in vitro cytotoxicity, ADME, and molecular docking studies

In the present study, a novel series of new furanone-based benzothiazole derivatives (4a-j) were synthesized from 4-(benzo[d]thiazol-2-yl)-4-oxobutanoic acid (3) as potential anticancer agents. In vitro cytotoxicity against three human cancer cell lines (A549, MCF7, and DUI45) revealed substantial activity. Di-substituted compound, 4i emerged as a promising anticancer compound which showed IC50 values of 7.2 ± 0.5, 6.6 ± 1.4, and 7.3 ± 0.1 µM against A549, MCF7, and DUI45 cell lines, respectively. Four compounds 4c, 4e, 4f, and 4i evaluated for their acute toxicity were found to be non-toxic on the two vital organs (liver and heart). Further, these compounds were found to be more efficient and less hepatotoxic in comparison to standard drug doxorubicin. Molecular docking studies carried out with VEGFR-2 revealed compounds 4a and 4i as potential VEGFR-2 kinase inhibitors. In silico ADME evaluation was carried out to estimate and predict drug-likeness. Compound 4i demonstrated the best ADME parameters. Based on the results of docking analyses, ADME, and in vitro cytotoxicity, compound 4i is identified as the lead compound for further development of anticancer agents.

Anticancer Effect of Heparin-Taurocholate Conjugate on Orthotopically Induced Exocrine and Endocrine Pancreatic Cancer

Simple Summary

Pancreatic cancer has a less than 9% 5-year survival rate among patients because it is very difficult to detect and diagnose early. Combinatorial chemotherapy with surgery or radiotherapy is a potential remedy to treat pancreatic cancer. However, these strategies still have side effects such as hair loss, skin soreness and fatigue. To overcome these side effects, angiogenesis inhibitors such as sunitinib are used to deliver targeted blood vessels around tumor tissues, including pancreatic cancer tumors. It is still controversial whether antiangiogenesis therapy is sufficient to treat pancreatic cancer. So far, many scientists have not been focused on the tumor types of pancreatic cancer when they have developed antipancreatic cancer medication. Here, we used heparin–taurocholate (LHT) as an anticancer drug to treat pancreatic cancer through inhibition of angiogenic growth factors. In this study, we examined the anticancer efficacy of LHT on various types of pancreatic cancer in an orthotopic model.

Abstract

Pancreatic cancers are classified based on where they occur, and are grouped into those derived from exocrine and those derived from neuroendocrine tumors, thereby experiencing different anticancer effects under medication. Therefore, it is necessary to develop anticancer drugs that can inhibit both types. To this end, we developed a heparin–taurocholate conjugate, i.e., LHT, to suppress tumor growth via its antiangiogenic activity. Here, we conducted a study to determine the anticancer efficacy of LHT on pancreatic ductal adenocarcinoma (PDAC) and pancreatic neuroendocrine tumor (PNET), in an orthotopic animal model. LHT reduced not only proliferation of cancer cells, but also attenuated the production of VEGF through ERK dephosphorylation. LHT effectively reduced the migration, invasion and tube formation of endothelial cells via dephosphorylation of VEGFR, ERK1/2, and FAK protein. Especially, these effects of LHT were much stronger on PNET (RINm cells) than PDAC (PANC1 and MIA PaCa-2 cells). Eventually, LHT reduced ~50% of the tumor weights and tumor volumes of all three cancer cells in the orthotopic model, via antiproliferation of cancer cells and antiangiogenesis of endothelial cells. Interestingly, LHT had a more dominant effect in the PNET-induced tumor model than in PDAC in vivo. Collectively, these findings demonstrated that LHT could be a potential antipancreatic cancer medication, regardless of pancreatic cancer types.

Nxhl Controls Angiogenesis by Targeting VE-PTP Through Interaction With Nucleolin

Precise regulation of angiogenesis is required for organ development, wound repair, and tumor progression. Here, we identified a novel gene, nxhl (New XingHuo light), that is conserved in vertebrates and that plays a crucial role in vascular integrity and angiogenesis. Bioinformatic analysis uncovered its essential roles in development based on co-expression with several key developmental genes. Knockdown of nxhl in zebrafish causes global and pericardial edema, loss of blood circulation, and vascular defects characterized by both reduced vascularization in intersegmental vessels and decreased sprouting in the caudal vein plexus. The nxhl gene also affects human endothelial cell behavior in vitro. We found that nxhl functions in part by targeting VE-PTP through interaction with NCL (nucleolin). Loss of ptprb (a VE-PTP ortholo) in zebrafish resulted in defects similar to nxhl knockdown. Moreover, nxhl deficiency attenuates tumor invasion and proteins (including VE-PTP and NCL) associated with angiogenesis and EMT. These findings illustrate that nxhl can regulate angiogenesis via a novel nxhl-NCL-VE-PTP axis, providing a new therapeutic target for modulating vascular formation and function, especially for cancer treatment.

Blood-Brain Barrier Repair of Bevacizumab and Corticosteroid as Prediction of Clinical Improvement and Relapse Risk in Radiation-Induced Brain Necrosis: A Retrospective Observational Study

Background

Blood-brain barrier (BBB) disruption after endothelial damage is a crucial part of radiation-induced brain necrosis (RN), but little is known of BBB disruption quantification and its role in the evaluation of therapeutic effect and prognosis for drug treatment. In this retrospective study, BBB repair by bevacizumab and corticosteroid and the correlation between BBB permeability and treatment response and relapse were evaluated by dynamic contrast-enhanced MRI (DCE-MRI).

Methods

Forty-one patients with RN after radiotherapy for nasopharyngeal carcinoma (NPC) (28 treated with bevacizumab and 13 with corticosteroid), 12 patients with no RN after NPC radiotherapy, and 12 patients with no radiotherapy history were included as RN, non-RN, and normal groups, respectively. DCE-MRI assessed BBB permeability in white matter of bilateral temporal lobe. DCE parameters were compared at baseline among the three groups. DCE parameters after treatment were compared and correlated with RN volume decrease, neurological improvement, and relapse.

Results

The extent of BBB leakage at baseline increased from the normal group and non-RN group and to RN necrosis lesions, especially K ^trans (Kruskal-Wallis test, P < 0.001). In the RN group, bevacizumab-induced K ^trans and v _e decrease in radiation necrosis lesions (both P < 0.001), while corticosteroid showed no obvious effect on BBB. The treatment response rate of bevacizumab was significantly higher than that of corticosteroid [30/34 (88.2%) vs. 10/22 (45.4%), P < 0.001]. Spearman analysis showed baseline K ^trans, K _ep, and v _p positively correlated with RN volume decrease and improvement of cognition and quality of life in bevacizumab treatment. After a 6-month follow-up for treatment response cases, the relapse rate of bevacizumab and corticosteroid was 10/30 (33.3%) and 2/9 (22.2%), respectively, with no statistical difference. Post-bevacizumab K ^trans level predicted relapse in 6 months with AUC 0.745 (P < 0.05, 95% CI 0.546-0.943, sensitivity = 0.800, specificity = 0.631).

Conclusions

Bevacizumab improved BBB leakage in RN necrosis. DCE parameters may be useful to predict therapeutic effect and relapse after bevacizumab.

The Adrenergic Nerve Network in Cancer

The central and autonomic nervous systems interact and converge to build up an adrenergic nerve network capable of promoting cancer. While a local adrenergic sympathetic innervation in peripheral solid tumors influences cancer and stromal cell behavior, the brain can participate to the development of cancer through an intermixed dysregulation of the sympathoadrenal system, adrenergic neurons, and the hypothalamo-pituitary-adrenal axis. A deeper understanding of the adrenergic nerve circuitry within the brain and tumors and its interactions with the microenvironment should enable elucidation of original mechanisms of cancer and novel therapeutic strategies.

Gemcitabine with or without ramucirumab as second-line treatment for malignant pleural mesothelioma (RAMES): a randomised, double-blind, placebo-controlled, phase 2 trial

BACKGROUND

There is a preclinical rationale for inhibiting angiogenesis in mesothelioma. We aimed to assess the efficacy and safety of the anti-VEGFR-2 antibody ramucirumab combined with gemcitabine in patients with pretreated malignant pleural mesothelioma.

METHODS

RAMES was a multicentre, randomised, double-blind, placebo-controlled, phase 2 trial done at 26 hospitals in Italy. Eligible patients were aged 18 years or older, had Eastern Cooperative Oncology Group performance status 0-2, and histologically proven malignant pleural mesothelioma progressing during or after first-line treatment with pemetrexed plus platinum. Patients were randomly assigned (1:1) to receive intravenous gemcitabine 1000 mg/m2 on days 1 and 8 every 3 weeks plus either intravenous placebo (gemcitabine plus placebo group) or ramucirumab 10 mg/kg (gemcitabine plus ramucirumab group) on day 1 every 3 weeks, until tumour progression or unacceptable toxicity. Central randomisation was done according to a minimisation algorithm method, associated with a random element using the following stratification factors: ECOG performance status, age, histology, and first-line time-to-progression. The primary endpoint was overall survival, measured from the date of randomisation to the date of death from any cause. Efficacy analyses were assessed in all patients who had been correctly randomised and received their allocated treatment, and safety analyses were assessed in all patients who received at least one dose of their assigned treatment. This trial is registered with ClinicalTrials.gov, NCT03560973, and with EudraCT, 2016-001132-36.

FINDINGS

Between Dec 22, 2016, and July 30, 2018, of 165 patients enrolled 161 were correctly assigned and received either gemcitabine plus placebo (n=81) or gemcitabine plus ramucirumab (n=80). At database lock (March 8, 2020), with a median follow-up of 21·9 months (IQR 17·7-28·5), overall survival was longer in the ramucirumab group (HR 0·71, 70% CI 0·59-0·85; p=0·028). Median overall survival was 13·8 months (70% CI 12·7-14·4) in the gemcitabine plus ramucirumab group and 7·5 months (6·9-8·9) in the gemcitabine plus placebo group. Grade 3-4 treatment-related adverse events were reported in 35 (44%) of 80 patients in the gemcitabine plus ramucirumab group and 24 (30%) of 81 in the gemcitabine plus placebo group. The most common treatment-related grade 3-4 adverse events were neutropenia (16 [20%] for gemcitabine plus ramucirumab vs ten [12%] for gemcitabine plus placebo) and hypertension (five [6%] vs none). Treatment-related serious adverse events were reported in five (6%) in the gemcitabine plus ramucirumab group and in four (5%) patients in the gemcitabine plus placebo group; the most common was thromboembolism (three [4%] for gemcitabine plus ramucirumab vs two [2%] for gemcitabine plus placebo). There were no treatment-related deaths.

INTERPRETATION

Ramucirumab plus gemcitabine significantly improved overall survival after first-line standard chemotherapy, with a favourable safety profile. This combination could be a new option in this setting.

FUNDING

Eli Lilly Italy.

TRANSLATION

For the Italian translation of the abstract see Supplementary Materials section.

Spatial and temporal VEGF receptor intracellular trafficking in microvascular and macrovascular endothelial cells

The vascular endothelial growth factor receptors (VEGFRs) can shape the neovascular phenotype of vascular endothelial cells when translocated to the nucleus, however the spatial and temporal changes in the intracellular distribution and translocation of VEGFRs to the nucleus and the organelles involved in this process is unclear. This study reports the effect of exogenous VEGF on translocation of VEGFRs and organelles in micro- and macrovascular endothelial cells. We showed that VEGF is responsible for: a rapid and substantial nuclear translocation of VEGFRs; VEGFR1 and VEGFR2 exhibit distinct spatial, temporal and structural translocation characteristics both in vitro and in vivo and this determines the nuclear VEGFR1:VEGFR2 ratio which differs between microvascular and macrovascular cells; VEGFR2 nuclear translocation is associated with the endosomal pathway transporting the receptor from Golgi in microvascular endothelial cells; and an increase in the volume of intracellular organelles. In conclusion, the nuclear translocation of VEGFRs is both receptor and vessel (macro versus micro) dependent and the endosomal pathway plays a key role in the translocation of VEGFRs to the nucleus and the subsequent export to the lysosomal system. Modulating VEGF-mediated VEGFR1 and VEGFR2 intracellular transmigration pathways may offer an alternative for the development of new anti-angiogenic therapies.

EIF4A3-induced circ_0084615 contributes to the progression of colorectal cancer via miR-599/ONECUT2 pathway

BACKGROUND

Colorectal cancer (CRC) is a common malignant tumor. Circular RNAs (circRNAs) have been reported to take part in the progression of CRC. However, the functions of circ_0084615 in CRC development are still undefined. In this study, we aimed to explore the functions and underlying mechanisms of circ_0084615 in CRC.

METHODS

qRT-PCR, western blot assay and IHC assay were utilized for the levels of circ_0084615, miR-599, ONECUT2 or EIF4A3. 5-ethynyl-2'-deoxyuridine (EdU) assay and colony formation assay were conducted for cell proliferation ability. Wound-healing assay and transwell assay were applied to evaluate cell migration and invasion. Tube formation assay was used to analyze angiogenesis ability. RNA immunoprecipitation (RIP) assay, RNA pull down assay and dual-luciferase reporter assay were used to analyze the relationships of circ_0084615, miR-599, ONECUT2 and EIF4A3. Murine xenograft model assay was employed for the role of circ_0084615 in vivo.

RESULTS

Circ_0084615 was elevated in CRC tissues and was linked to TNM stages, lymph node metastasis, differentiation and overall survival rate. Circ_0084615 knockdown inhibited CRC cell proliferation, migration, invasion and angiogenesis in vitro and hampered tumorigenesis in vivo. Circ_0084615 sponged miR-599 and miR-599 inhibition reversed circ_0084615 knockdown-mediated effects on CRC cell growth, motility and angiogenesis. ONECUT2 was identified as the target gene of miR-599. ONECUT2 overexpression recovered the effects of miR-599 on CRC malignant behaviors. Additionally, EIF4A3 induced circ_0084615 expression.

CONCLUSIONS

EIF4A3-induced circ_0084615 played an oncogenic role in CRC development via miR-599/ONECUT2 axis.

Pharmacotherapy for recurrent respiratory papillomatosis (RRP): a treatment update

Introduction: Recurrent respiratory papillomatosis is a rare human papillomavirus (HPV)-induced condition where warts grow within the airway and especially the larynx to effect voice and restrict breathing.Areas covered: A PubMed search using the following search terms was performed: respiratory papillomatosis and cidofovir, alpha-interferon, bevacizumab, PD1, and HPV vaccines. Surgery remains the mainstay of treatment. There has been a change in options available for adjuvant therapies with systemic bevacizumab and the potential benefits of prophylactic HPV vaccine. Despite efforts to identify a drug therapy to control RRP, no therapy yet remains which is predictable and effective in all. The current status of therapeutic vaccines and immunotherapy is discussed.Expert opinion: The current adjuvant therapies do offer a reasonable expectation of control but the effect for the individual is unpredictable despite the therapies being based on good science. The current therapies would allow an escalating treatment strategy to be formulated, however a single therapy is unlikely to be curative. Multi-center trials are required such that adequate numbers to show an effect are achieved.

Targeted Noninvasive Treatment of Choroidal Neovascularization by Hybrid Cell-Membrane-Cloaked Biomimetic Nanoparticles

Choroidal neovascularization (CNV) is the leading cause of vision loss in many blinding diseases, but current antiangiogenic therapies with invasively intravitreal injection suffer from poor patient compliance and a rate of devastating ocular complications. Here, we develop an alternative antiangiogenic agent based on hybrid cell-membrane-cloaked nanoparticles for noninvasively targeted treatment of CNV. The retinal endotheliocyte membrane coating provides as-fabricated nanoagents with homotypic targeting capability and binding ability to the vascular endothelial growth factor. The fusion of red blood cell membranes protects the hybrid membrane-coated nanoparticles from phagocytosis by macrophages. In a laser-induced wet age-related macular degeneration mouse model, a significantly enhanced accumulation is observed in CNV regions after intravenous delivery of the hybrid membrane-coated nanoparticles. Moreover, an excellent therapeutic efficacy is achieved in reducing the leakage and area of CNV. Overall, the biomimetic antiangiogenic nanoagents provide an effective approach for noninvasive treatment of CNV.

Anti-Angiogenic Property of Free Human Oligosaccharides

Angiogenesis, a fundamental process in human physiology and pathology, has attracted considerable attention owing to its potential as a therapeutic strategy. Vascular endothelial growth factor (VEGF) and its receptor (VEGFR) are deemed major mediators of angiogenesis. To date, inhibition of the VEGF-A/VEGFR-2 axis has been an effective strategy employed in the development of anticancer drugs. However, some limitations, such as low efficacy and side effects, need to be addressed. Several drug candidates have been discovered, including small molecule compounds, recombinant proteins, and oligosaccharides. In this review, we focus on human oligosaccharides as modulators of angiogenesis. In particular, sialylated human milk oligosaccharides (HMOs) play a significant role in the inhibition of VEGFR-2-mediated angiogenesis. We discuss the structural features concerning the interaction between sialylated HMOs and VEGFR-2 as a molecular mechanism of anti-angiogenesis modulation and its effectiveness in vivo experiments. In the current state, extensive clinical trials are required to develop a novel VEGFR-2 inhibitor from sialylated HMOs.

Vascular endothelial growth factor (VEGF) targeting therapy for persistent, recurrent, or metastatic cervical cancer

BACKGROUND

Cervical cancer ranks as the fourth leading cause of death from cancer in women. Historically, women with metastatic or recurrent cervical cancer have had limited treatment options. New anti-angiogenesis therapies, such as vascular endothelial growth factor (VEGF) targeting agents, offer an alternative strategy to conventional chemotherapy; they act by inhibiting the growth of new blood vessels, thereby restricting tumour growth by blocking the blood supply.

OBJECTIVES

To assess the benefits and harms of VEGF targeting agents in the management of persistent, recurrent, or metastatic cervical cancer.

SEARCH METHODS

We performed searches of the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, online registers of clinical trials, and abstracts of scientific meetings up until 27 May 2020.

SELECTION CRITERIA

We examined randomised controlled trials (RCTs) that evaluated the use of VEGF targeting agents alone or in combination with conventional chemotherapy or other VEGF targeting agents.

DATA COLLECTION AND ANALYSIS

Three review authors independently screened the results of search strategies, extracted data, assessed risk of bias, and analysed data according to the standard methods expected by Cochrane. The certainty of evidence was assessed via the GRADE approach.

MAIN RESULTS

A total of 1634 records were identified. From these, we identified four studies with a total of 808 participants for inclusion. We also identified two studies that were awaiting classification and nine ongoing studies. Bevacizumab plus chemotherapy versus chemotherapy Treatment with bevacizumab plus chemotherapy may result in lower risk of death compared to chemotherapy alone (hazard ratio (HR) 0.77, 95% confidence interval (CI) 0.62 to 0.95; 1 study, 452 participants; low-certainty evidence). However, there are probably more specific adverse events when compared to chemotherapy alone, including gastrointestinal perforations or fistulae (risk ratio (RR) 18.00, 95% CI 2.42 to 133.67; 1 study, 440 participants; moderate-certainty evidence); serious thromboembolic events (RR 4.5, 95% CI 1.55 to 13.08; 1 study, 440 participants; moderate-certainty evidence); and hypertension (RR 13.75, 95% CI 5.07 to 37.29; 1 study, 440 participants; moderate-certainty evidence). There may also be a higher incidence of serious haemorrhage (RR 5.00, 95% CI 1.11 to 22.56; 1 study, 440 participants; low-certainty evidence). In addition, the incidence of serious adverse events is probably higher (RR 1.44, 95% CI 1.16 to 1.79; 1 study, 439 participants; moderate-certainty evidence). The incremental cost-effectiveness ratio was USD 295,164 per quality-adjusted life-year (1 study, 452 participants; low-certainty evidence). Cediranib plus chemotherapy versus chemotherapy Treatment with cediranib plus chemotherapy may or may not result in similar risk of death when compared to chemotherapy alone (HR 0.94, 95% CI 0.53 to 1.65; 1 study, 69 participants; low-certainty evidence). We found very uncertain results for the incidences of specific adverse events, including gastrointestinal perforations or fistulae (RR 3.27, 95% CI 0.14 to 77.57; 1 study, 67 participants; very low-certainty evidence); serious haemorrhage (RR 5.45, 95% CI 0.27 to 109.49; 1 study, 67 participants; very low-certainty evidence); serious thromboembolic events (RR 3.41, 95% CI 0.14 to 80.59; 1 study, 60 participants; very low-certainty evidence); and serious hypertension (RR 0.36, 95% CI 0.02 to 8.62; 1 study, 67 participants; very low-certainty evidence). In addition, there may or may not be a similar incidence of serious adverse events compared to chemotherapy alone (RR 1.15, 95% CI 0.75 to 1.78; 1 study, 67 participants; low-certainty evidence). Apatinib plus chemotherapy or chemotherapy/brachytherapy versus chemotherapy or chemotherapy/brachytherapy Treatment with apatinib plus chemotherapy or chemotherapy/brachytherapy may or may not result in similar risk of death compared to chemotherapy alone or chemotherapy/brachytherapy alone (HR 0.90, 95% CI 0.51 to 1.60; 1 study, 52 participants; low-certainty evidence). However, hypertension events may occur at a higher incidence as compared to chemotherapy alone or chemotherapy/brachytherapy alone (RR 5.14, 95% CI 1.28 to 20.73; 1 study, 52 participants; low-certainty evidence). Pazopanib plus lapatinib versus lapatinib Treatment with pazopanib plus lapatinib may result in higher risk of death compared to lapatinib alone (HR 2.71, 95% CI 1.16 to 6.31; 1 study, 117 participants; low-certainty evidence). We found very uncertain results for the incidences of specific adverse events, including gastrointestinal perforations or fistulae (RR 2.00, 95% CI 0.19 to 21.59; 1 study, 152 participants; very low-certainty evidence); haemorrhage (RR 2.00, 95% CI 0.72 to 5.58; 1 study, 152 participants; very low-certainty evidence); and thromboembolic events (RR 3.00, 95% CI 0.12 to 72.50; 1 study, 152 participants; very low-certainty evidence). In addition, the incidence of hypertension events is probably higher (RR 12.00, 95% CI 2.94 to 49.01; 1 study, 152 participants; moderate-certainty evidence). There may or may not be a similar incidence of serious adverse events as compared to lapatinib alone (RR 1.45, 95% CI 0.94 to 2.26; 1 study, 152 participants; low-certainty evidence). Pazopanib versus lapatinib Treatment with pazopanib may or may not result in similar risk of death as compared to lapatinib (HR 0.96, 95% CI 0.67 to 1.38; 1 study, 152 participants; low-certainty evidence). We found very uncertain results for the incidences of specific adverse events, including gastrointestinal perforations or fistulae (RR 1.03, 95% CI 0.07 to 16.12; 1 study, 150 participants; very low-certainty evidence); haemorrhage (RR 1.03, 95% CI 0.31 to 3.40; 1 study, 150 participants; very low-certainty evidence); and thromboembolic events (RR 3.08, 95% CI 0.13 to 74.42; 1 study, 150 participants; very low-certainty evidence). In addition, the incidence of hypertension events is probably higher (RR 11.81, 95% CI 2.89 to 48.33; 1 study, 150 participants; moderate-certainty evidence). The risk of serious adverse events may or may not be similar as compared to lapatinib (RR 1.31, 95% CI 0.83 to 2.07; 1 study, 150 participants; low-certainty evidence).

AUTHORS' CONCLUSIONS

We found low-certainty evidence in favour of the use of bevacizumab plus chemotherapy. However, bevacizumab probably increases specific adverse events (gastrointestinal perforations or fistulae, thromboembolic events, hypertension) and serious adverse events. We found low-certainty evidence that does not support the use of cediranib plus chemotherapy, apatinib plus chemotherapy, apatinib plus chemotherapy/brachytherapy, or pazopanib monotherapy. We found low-certainty evidence suggesting that pazopanib plus lapatinib worsens outcomes. The VEGF inhibitors apatinib and pazopanib may increase the probability of hypertension events.

Controlling the immobilization process of an optically enhanced protein microarray for highly reproducible immunoassay

By virtue of its high throughput multiplex detection capability, superior read-out sensitivity, and tiny analyte consumption, an optically enhanced protein microarray assay has been developed as a promising diagnostic tool for various applications, ranging from the field of pharmacology to diagnostics. However, so far, the development of an optically enhanced protein microarray (OEPM) toward widespread commercial availability is mainly hampered by insufficient detection reproducibility. Here, we develop an OEPM platform with an order of magnitude optical enhancement induced by the interference effect. High assay reproducibility of the OEPM is achieved by optimizing the protein immobilization schemes, linking to the surface energy of the substrate, surfactant-tuned wetting ability, and the washing and drying dynamics. As a result, smearing-free and uniform spot arrays with a coefficient of variation less than 7% can be achieved. Furthermore, we demonstrate the assay performance of the OEPM by detecting five biomarkers, showing an order of magnitude higher sensitivity, many-fold higher throughput, and 10 times less analyte consumption than those of the commercial enzyme-linked immunosorbent assay kits. Our results provide new insight for improving the reproducibility of OEPMs toward practical and commercial diagnostic assays.

Novel DEK-Targeting Aptamer Delivered by a Hydrogel Microneedle Attenuates Collagen-Induced Arthritis

DEK protein is critical to the formation of neutrophil extracellular traps (NETs) in rheumatoid arthritis (RA). Blocking DEK using the aptamer DTA via articular injection has been shown to have robust anti-inflammatory efficacy in a previous study. However, DTA is prone to nuclease degradation and renal clearance in vivo. RA is a systemic disease that involves multiple joints, and local injection is impractical in clinical settings. In this study, DTA was modified with methoxy groups on all deoxyribose sugar units and inverted deoxythymidine on the 3' end (DTA4) to enhance its stability against nuclease. DTA4 is stable for 72 h in 90% mouse serum and maintains a high binding affinity to DEK. DTA4 effectively inhibits the formation of NETs and the migration of HUVECs in vitro. DTA4 was then modified with cholesterol on its 5' end to form DTA6. DTA6 dramatically reduces DEK expression in inflammatory RAW264.7 cells. A hydrogel microneedle (hMN) was then fabricated for the transdermal delivery of DTA6. The hMN maintains morphological integrity after absorbing the aptamer solution, effectively pierces the skin, and rapidly releases DTA6 into the dermis. The DTA6-loaded hMN significantly attenuates inflammation and protects joints from cartilage/bone erosion in collagen-induced arthritis (CIA) mice.

Antiangiogenic effects of AG36, a triterpenoid saponin from Ardisia gigantifolia stapf

AG36 is a triterpenoid saponin from Ardisia gigantifolia stapf. Our recent studies proved that AG36 displayed prominent cytotoxicity against breast cancer cells both in vitro and in vivo. However, whether AG36 has antiangiogenic properties is unknown. Therefore, in the present study, we evaluated the antiangiogenic effect of AG36 and the underlying mechanism. The results indicated that AG36 could significantly inhibit the proliferation, migration and invasion of human umbilical vein endothelial cells (HUVEC). Further antiangiogenic molecular mechanism investigation showed that AG36 significantly suppressed phosphorylated FAK and AKT, and downregulated the expressions of vascular endothelial growth factor (VEGF) and vascular endothelial growth factor receptor 2 (VEGFR2) in HUVECs. PI3K inhibitor (LY294002) and FAK inhibitor (PF562271) pretreatment could markedly enhance AG36-induced inhibition of HUVEC proliferation and p-FAK suppression, respectively. In addition, AG36 inhibited the tumor growth in xenograft model and expressions of p-VEGFR2 and p-Akt in vivo. Molecular docking simulation indicated that AG36 formed hydrogen bonds and hydrophobic interactions within the ATP binding pocket of VEGFR2 kinase domain. The present study firstly revealed the high antiangiogenic potency and related underlying molecular of AG36, demonstrating that AG36 maybe a potential antiangiogenic cancer therapy agent or lead candidate.

Vascular Endothelial Growth Factor Blockade Induces Dermal Endothelial Cell Apoptosis in a Clinically Relevant Skin Organ Culture Model

BACKGROUND/AIMS

Vascular endothelial growth factor (VEGF), a key mediator of angiogenesis, plays a key role in physiological processes and is a major contributor to several diseases including cancer and psoriasis. Anti-VEGF therapies are widely used as cancer and ophthalmological treatments. There is some evidence that VEGF blockade may have utility in the management of psoriasis, although their potential has been largely unexplored. We hypothesized that a human skin organ culture could provide a stable ex vivo model in which the cutaneous microvascular network could be studied and experimentally manipulated.

METHODS

Punch biopsies (3 mm) of skin, donated by healthy individuals (39-72 years old, n = 5), were incubated with monoclonal antibody (mAb) to human VEGF (bevacizumab) at doses based on data from animal and clinical studies. After 3-day culture, cell death and proliferation as well as vascular endothelial cell changes were assessed using quantitative immunohistomorphometry.

RESULTS

Anti-VEGF mAb at 0.8 mg/mL induced a significant increase in cleaved caspase-3 expression in CD31+ cells (p < 0.05). None of the doses tested increased TUNEL or decreased Ki-67 expression in the basal layer of the epidermis, confirming the model's viability. In addition, the lactate dehydrogenase (LDH) assay showed no increase in LDH activity in treated samples compared to untreated control. The highest anti-VEGF mAb dose (0.8 mg/mL) induced an increase in TUNEL expression in the upper epidermis, which did not correlate with caspase-3 immunoreactivity. Further investigation revealed that anti-VEGF mAb did not change the expression of markers of terminal differentiation such as keratin 10, filaggrin, and involucrin, suggesting that VEGF depletion does not affect keratinocyte terminal differentiation. In contrast to the control group, levels of VEGF protein were undetectable in the culture supernatant of samples treated with 0.8 mg/mL of anti-VEGF mAb, suggesting sufficient dose.

CONCLUSION

Our pilot study provides the first evidence that anti-VEGF therapy promotes endothelial cell apoptosis in human skin ex vivo. Our pragmatic human skin organ culture assay offers a valuable tool for future preclinical endothelial cell and translational microvascular network/anti-angiogenesis research in human skin.

Exploiting the dynamics of the EPR effect and strategies to improve the therapeutic effects of nanomedicines by using EPR effect enhancers

The enhanced permeability and retention (EPR) effect is a unique phenomenon of solid tumors that is related to their particular anatomical and pathophysiological characteristics, e.g. defective vascular architecture; large gaps between endothelial cells in blood vessels; abundant vascular mediators such as bradykinin, nitric oxide, carbon monoxide, and vascular endothelial growth factor; and impaired lymphatic recovery. These features lead to tumor tissues showing considerable extravasation of plasma components and nanomedicines. These data comprise the basic theory underlying the development of macromolecular agents or nanomedicines. The EPR effect is not necessarily valid for all solid tumors, because tumor blood flow and vascular permeability vary greatly. Tumor blood flow is frequently obstructed as tumor size increases, as often seen clinically; early stage, small tumors show a more uniform EPR effect, whereas advanced large tumor show heterogeneity in EPR effect. Accordingly, it would be very important to apply enhancers of EPR effect in clinical setting to make EPR effect more uniform. In this review, we discuss the EPR effect: its history, factors involved, and dynamics and heterogeneity. Strategies to overcome the EPR effect's heterogeneity may guarantee better therapeutic outcomes of drug delivery to advanced cancers.