Antiangiogenic cancer treatment: The great discovery and greater complexity (Review)

Cancer-associated Fibroblast-specific Expression of the Matricellular Protein CCN1 Coordinates Neovascularization and Stroma Deposition in Melanoma Metastasis

Melanoma is the leading cause of skin cancer-related death. As prognosis of patients with melanoma remains problematic, identification of new therapeutic targets remains essential. Matricellular proteins are nonstructural extracellular matrix proteins. They are secreted into the tumor microenvironment to coordinate behavior among different cell types, yet their contribution to melanoma is underinvestigated. Examples of matricellular proteins include those comprising the CCN family. The CCN family member, CCN1, is highly proangiogenic. Herein, we show that, in human patients with melanoma, although found in several tumor cell types, CCN1 is highly expressed by a subset of cancer-associated fibroblasts (CAF) in patients with melanoma and this expression correlates positively with expression of proangiogenic genes and progressive disease/resistance to anti-PD1 checkpoint inhibitors. Consistent with these observations, in a syngeneic C57BL6 mouse model of melanoma, loss of CCN1 expression from Col1A2-Cre-, herein identified as "universal," fibroblasts, impaired metastasis of subcutaneously injected B16F10 tumor cells to lung, concomitant with disrupted neovascularization and collagen organization. Disruption of the extracellular matrix in the loss of CCN1 was validated using a novel artificial intelligence-based image analysis platform that revealed significantly decreased phenotypic fibrosis and composite morphometric collagen scores. As drug resistance is linked to matrix deposition and neoangiogenesis, these data suggest that CCN1, due to its multifaceted role, may represent a novel therapeutic target for drug-resistant melanoma. Our data further emphasize the essential role that cancer-associated, (universal) Col1A2-Cre-fibroblasts and extracellular matrix remodeling play in coordinating behavior among different cell types within the tumor microenvironment.

SIGNIFICANCE

In human patients, the expression of proangiogenic matricellular protein CCN1 in CAFs correlates positively with expression of stroma and angiogenic markers and progressive disease/resistance to checkpoint inhibitor therapy. In an animal model, loss of CCN1 from CAFs impaired metastasis of melanoma cells, neovascularization, and collagen deposition, emphasizing that CAFs coordinate cellular behavior in a tumor microenvironment and that CCN1 may be a novel target.

Bevacizumab, Irinotecan, or Topotecan Added to Temozolomide for Children With Relapsed and Refractory Neuroblastoma: Results of the ITCC-SIOPEN BEACON-Neuroblastoma Trial

PURPOSE

Outcomes for children with relapsed and refractory high-risk neuroblastoma (RR-HRNB) remain dismal. The BEACON Neuroblastoma trial (EudraCT 2012-000072-42) evaluated three backbone chemotherapy regimens and the addition of the antiangiogenic agent bevacizumab (B).

MATERIALS AND METHODS

Patients age 1-21 years with RR-HRNB with adequate organ function and performance status were randomly assigned in a 3 × 2 factorial design to temozolomide (T), irinotecan-temozolomide (IT), or topotecan-temozolomide (TTo) with or without B. The primary end point was best overall response (complete or partial) rate (ORR) during the first six courses, by RECIST or International Neuroblastoma Response Criteria for patients with measurable or evaluable disease, respectively. Safety, progression-free survival (PFS), and overall survival (OS) time were secondary end points.

RESULTS

One hundred sixty patients with RR-HRNB were included. For B random assignment (n = 160), the ORR was 26% (95% CI, 17 to 37) with B and 18% (95% CI, 10 to 28) without B (risk ratio [RR], 1.52 [95% CI, 0.83 to 2.77]; P = .17). Adjusted hazard ratio for PFS and OS were 0.89 (95% CI, 0.63 to 1.27) and 1.01 (95% CI, 0.70 to 1.45), respectively. For irinotecan ([I]; n = 121) and topotecan (n = 60) random assignments, RRs for ORR were 0.94 and 1.22, respectively. A potential interaction between I and B was identified. For patients in the bevacizumab-irinotecan-temozolomide (BIT) arm, the ORR was 23% (95% CI, 10 to 42), and the 1-year PFS estimate was 0.67 (95% CI, 0.47 to 0.80).

CONCLUSION

The addition of B met protocol-defined success criteria for ORR and appeared to improve PFS. Within this phase II trial, BIT showed signals of antitumor activity with acceptable tolerability. Future trials will confirm these results in the chemoimmunotherapy era.

Cancer chemotherapy resistance: Mechanisms and recent breakthrough in targeted drug delivery

Conventional chemotherapy, one of the most widely used cancer treatment methods, has serious side effects, and usually results in cancer treatment failure. Drug resistance is one of the primary reasons for this failure. The most significant drawbacks of systemic chemotherapy are rapid clearance from the circulation, the drug's low concentration in the tumor site, and considerable adverse effects outside the tumor. Several ways have been developed to boost neoplasm treatment efficacy and overcome medication resistance. In recent years, targeted drug delivery has become an essential therapeutic application. As more mechanisms of tumor treatment resistance are discovered, nanoparticles (NPs) are designed to target these pathways. Therefore, understanding the limitations and challenges of this technology is critical for nanocarrier evaluation. Nano-drugs have been increasingly employed in medicine, incorporating therapeutic applications for more precise and effective tumor diagnosis, therapy, and targeting. Many benefits of NP-based drug delivery systems in cancer treatment have been proven, including good pharmacokinetics, tumor cell-specific targeting, decreased side effects, and lessened drug resistance. As more mechanisms of tumor treatment resistance are discovered, NPs are designed to target these pathways. At the moment, this innovative technology has the potential to bring fresh insights into cancer therapy. Therefore, understanding the limitations and challenges of this technology is critical for nanocarrier evaluation.

Anti-angiogenic potential of bioactive phytochemicals from Helicteres isora targeting VEGFR-2 to fight cancer through molecular docking and molecular dynamics simulation

Cancer is one of the leading causes of death due to its very high rate of morbidity and mortality, and there is a constant demand of effective drugs for cancer therapy. Vascular endothelial growth factor receptor-2 (VEGFR-2) plays a significant role as central modulator of angiogenesis and is targeted frequently for developing anti-angiogenic agents to fight cancer. Helicteres isora L. (Malvaceae) is reported to possess diverse medicinal properties including anti-cancer potentials. In the current investigation, 38 bioactive phytochemicals of H. isora were screened virtually to evaluate their anti-angiogenic potentials targeting VEGFR-2. The study unveiled three potential candidates such as, Diosgenin (-9.8 Kcal//mol), Trifolin (-8.4 Kcal/mol) and Yohimbine (-8.1 Kcal/mol) that showed favorable pharmacokinetic, pharmacodynamic and toxicity properties with no significant side effects. Molecular dynamics simulation employing 100 ns revealed noteworthy structural stability and compactness for all the top three candidates. The MM/GBSA binding free energy estimation corroborated the docking interactions where Yohimbine (-30.47 Kcal/mol) scored better than Diosgenin (-27.54 Kcal/mol) and Trifolin (-29.58 Kcal/mol). Target class prediction revealed enzymes in most of the cases and some FDA approved drugs were found as structurally similar analogs for Trifolin and Yohimbine. These findings could lead to the development of novel and effective anti-angiogenic agents.Communicated by Ramaswamy H. Sarma.

Emilin2 fosters vascular stability by promoting pericyte recruitment

Angiogenesis, the formation of the new blood vessels from pre-existing vasculature, is an essential process occurring under both normal and pathological conditions, such as inflammation and cancer. This complex process is regulated by several cytokines, growth factors and extracellular matrix components modulating endothelial cell and pericyte function. In this study, we discovered that the extracellular matrix glycoprotein Elastin Microfibril Interfacer 2 (Emilin2) plays a prominent role in pericyte physiology. This work was originally prompted by the observations that tumor-associated vessels from Emilin2-/- mice display less pericyte coverage, impaired vascular perfusion, and reduced drug efficacy, suggesting that Emilin2 could promote vessel maturation and stabilization affecting pericyte recruitment. We found that Emilin2 affects different mechanisms engaged in pericyte recruitment and vascular stabilization. First, human primary endothelial cells challenged with recombinant Emilin2 synthesized and released ∼ 2.1 and 1.2 folds more PDGF-BB and HB-EGF, two cytokines known to promote pericyte recruitment. We also discovered that Emilin2, by directly engaging α5β1 and α6β1 integrins, highly expressed in pericytes, served as an adhesion substrate and haptotactic stimulus for pericytes. Moreover, Emilin2 evoked increased NCadherin expression via the sphingosine-1-phosphate receptor, leading to enhanced vascular stability by fostering interconnection between endothelial cells and pericytes. Finally, restoring pericyte coverage in melanoma and ovarian tumor vessels developed in Emilin2-/- mice improved drug delivery to the tumors. Collectively, our results implicate Emilin2 as a prominent regulator of pericyte function and suggest that Emilin2 expression could represent a promising maker to predict the clinical outcome of patients with melanoma, ovarian, and potentially other forms of cancer.

New thiouracil derivatives as histone deacetylase inhibitors and apoptosis inducers: design, synthesis and anticancer evaluation

Background: Histone deacetylase (HDAC) inhibitors have good contributions in cancer management. Aim: To introduce new active HDAC inhibitors. Methods: Design and synthesis of 16 thiouracil derivatives with deep biological and computational investigation. Results: Compounds 7a, 7c, 7d, 7e, 8a and 8f showed the highest antiproliferative effects against MCF7, HepG2 and HCT116 cell lines. Compound 7e exhibited the highest activities against HDAC1 and HDAC4. Compound 7e arrested the cell cycle of HCT116 cells at G0-G1 with significant apoptotic effect. In addition, treatment with compound 7e was associated with a significant increase in the levels of caspase-3 and caspase-8. The docking studies gave good insight about the binding patterns of the synthesized compounds against HDAC1. Conclusion: Compound 7e has a promising anticancer activity targeting HDAC.

Gold nanoparticles as antiangiogenic and antimetastatic agents

Angiogenesis and metastasis are two interdependent cancer hallmarks, the latter of which is the key cause of treatment failure. Thus, establishing effective antiangiogenesis/antimetastasis agents is the final frontier in cancer research. Gold nanoparticles (GNPs) may provide disruptive advancements in this regard due to their intrinsic physical and physiological features. Here, we comprehensively discuss recent potential therapeutical strategies to treat angiogenesis and metastasis and present a critical review on the state-of-the-art in vitro and in vivo evaluations of the antiangiogenic/antimetastatic activity of GNPs. Finally, we provide perspectives on the contribution of GNPs to the advancement of cancer management.

Effect of the Marine Polyketide Plocabulin on Tumor Progression

Marine sponges represent one of the richest sources of natural marine compounds with anticancer potential. Plocabulin (PM060184), a polyketide originally isolated from the sponge Lithoplocamia lithistoides, elicits its main anticancer properties binding tubulin, which still represents one of the most important targets for anticancer drugs. Plocabulin showed potent antitumor activity, in both in vitro and in vivo models of different types of cancers, mediated not only by its antitubulin activity, but also by its ability to block endothelial cell migration and invasion. The objective of this review is to offer a description of plocabulin's mechanisms of action, with special emphasis on the antiangiogenic signals and the latest progress on its development as an anticancer agent.

Synergistic effect of combining sunitinib with a peptide-based vaccine in cancer treatment after microenvironment remodeling

Although it has proven difficult to demonstrate the clinical efficacy of therapeutic vaccination as a monotherapy in advanced cancers, its combination with an immunomodulatory treatment to reduce intra-tumor immunosuppression and improve vaccine efficacy is a very promising strategy. In this context, we are studying the combination of a vaccine composed of peptides of the tumor antigen survivin (SVX vaccine) with the anti-angiogenic agent sunitinib in a colorectal carcinoma model. To this end, we have been focusing on administration scheduling and have highlighted a therapeutic synergy between SVX vaccine and sunitinib when the vaccine was administered at the end of anti-angiogenic treatment. In this setting, a prolonged control of tumor growth associated with an important percentage of complete tumor regression was observed. Studying the remodeling induced by each therapy on the immunological and angiogenic tumor microenvironment over time we observed, during sunitinib treatment, a transient increase in polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs) and a decrease in NK cells in the tumor microenvironment. In contrast, after sunitinib treatment was stopped, a decrease in PMN-MDSC populations has been observed in the tumor, associated with an increase in NK cells, pericyte coverage of tumor vessels and CD8⁺ T cell population and functionality. In conclusion, sunitinib treatment results in the promotion of an immune-favorable tumor microenvironment that can guide the optimal sequence of vaccine and anti-angiogenic combination to reinforce their synergy.

Functional Characterization of lncRNA152 as an Angiogenesis-Inhibiting Tumor Suppressor in Triple-Negative Breast Cancers

Long noncoding RNAs have been implicated in many of the hallmarks of cancer. Herein, we found that the expression of lncRNA152 (lnc152; a.k.a. DRAIC), which we annotated previously, is highly upregulated in luminal breast cancer (LBC) and downregulated in triple-negative breast cancer (TNBC). Knockdown of lnc152 promotes cell migration and invasion in LBC cell lines. In contrast, ectopic expression of lnc152 inhibits growth, migration, invasion, and angiogenesis in TNBC cell lines. In mice, lnc152 inhibited the growth of TNBC cell xenografts, as well as metastasis of TNBC cells in an intracardiac injection model. Transcriptome analysis of the xenografts indicated that lnc152 downregulates genes controlling angiogenesis. Using pull down assays followed by LC/MS-MS, we identified RBM47, a known tumor suppressor in breast cancer, as a lnc152-interacting protein. The effects of lnc152 in TNBC cells are mediated, in part, by regulating the expression of RBM47. Collectively, our results demonstrate that lnc152 is an angiogenesis-inhibiting tumor suppressor that attenuates the aggressive cancer-related phenotypes found in TNBC.

IMPLICATIONS

This study identifies lncRNA152 as an angiogenesis-inhibiting tumor suppressor that attenuates the aggressive cancer-related phenotypes found in TNBC by upregulating the expression of the tumor suppressor RBM47. As such, lncRNA152 may serve as a biomarker to track aggressiveness of breast cancer, as well as therapeutic target for treating TNBC.

Cancer-associated fibroblasts: Origin, function, imaging, and therapeutic targeting

The tumor microenvironment (TME) is emerging as one of the primary barriers in cancer therapy. Cancer-associated fibroblasts (CAF) are a common inhabitant of the TME in several tumor types and play a critical role in tumor progression and drug resistance via different mechanisms such as desmoplasia, angiogenesis, immune modulation, and cancer metabolism. Due to their abundance and significance in pro-tumorigenic mechanisms, CAF are gaining attention as a diagnostic target as well as to improve the efficacy of cancer therapy by their modulation. In this review, we highlight existing imaging techniques that are used for the visualization of CAF and CAF-induced fibrosis and provide an overview of compounds that are known to modulate CAF activity. Subsequently, we also discuss CAF-targeted and CAF-modulating nanocarriers. Finally, our review addresses ongoing challenges and provides a glimpse into the prospects that can spearhead the transition of CAF-targeted therapies from opportunity to reality.

Modulation of Fibroblast Activity via Vitamin D3 Is Dependent on Tumor Type—Studies on Mouse Mammary Gland Cancer

Simple Summary

This study, which was conducted in healthy mice and mice bearing three mouse mammary gland cancers—4T1, 67NR, and E0771—showed that the divergent effects of vitamin D₃ supplementation (5000 IU) or deficiency (100 IU of vitamin D₃) observed in healthy mice led to the formation of various body microenvironments depending on the mouse strain. Developing tumors themselves modified the microenvironments by producing higher concentrations of osteopontin, SDF-1 (4T1), TGF-β (4T1 and E0771), CCL2, VEGF, FGF23 (E0771), and IL-6 (67NR), which influences the response to vitamin D₃ supplementation/deficiency and calcitriol administration and leads to enhanced/decreased activation of lung fibroblasts and modulation of tumor tissue blood flow.

Abstract

Vitamin D₃ and its analogs are known to modulate the activity of fibroblasts under various disease conditions. However, their impact on cancer-associated fibroblasts (CAFs) is yet to be fully investigated. The aim of this study was to characterize CAFs and normal fibroblasts (NFs) from the lung of mice bearing 4T1, 67NR, and E0771 cancers and healthy mice fed vitamin-D₃-normal (1000 IU), -deficient (100 IU), and -supplemented (5000 IU) diets. The groups receiving control (1000 IU) and deficient diets (100 IU) were gavaged with calcitriol (+cal). In the 4T1-bearing mice from the 100 IU+cal group, increased NFs activation (increased α-smooth muscle actin, podoplanin, and tenascin C (TNC)) with a decreased blood flow in the tumor was observed, whereas the opposite effect was observed in the 5000 IU and 100 IU groups. CAFs from the 5000 IU group of E0771-bearing mice were activated with increased expression of podoplanin, platelet-derived growth factor receptor β, and TNC. In the 100 IU+cal group of E0771-bearing mice, a decreased blood flow was recorded with decreased expression of fibroblast growth factor 23 (FGF23) and C-C motif chemokine ligand 2 (CCL2) in tumors and increased expression of TNC on CAFs. In the 67NR model, the impact of vitamin D₃ on blood flow or CAFs and lung NFs was not observed despite changes in plasma and/or tumor tissue concentrations of osteopontin (OPN), CCL2, transforming growth factor-β, vascular endothelial growth factor, and FGF23. In healthy mice, divergent effects of vitamin D₃ supplementation/deficiency were observed, which lead to the creation of various body microenvironments depending on the mouse strain. Tumors developing in such microenvironments themselves modified the microenvironments by producing, for example, higher concentrations of OPN and stromal-cell-derived factor 1 (4T1), which influences the response to vitamin D₃ supplementation/deficiency and calcitriol administration.

Chlorinated benzothiadiazines inhibit angiogenesis through suppression of VEGFR2 phosphorylation

Angiogenesis inhibitors are a critical pharmacological tool for the treatment of solid tumors. Suppressing vascular permeability leads to inhibition of tumor growth, invasion, and metastatic potential by blocking the supply of oxygen and nutrients. Disruption of the vascular endothelial growth factor (VEGF) signaling pathway is a validated target for the design of antiangiogenic agents. Several VEGFR2 inhibitors have been clinically approved over the past years. Structural analysis of these clinical VEGFR2 inhibitors highlighted key functional group overlap with the benzothiadiazine core contained in a library of in-house compounds. Herein we ascribe anti-angiogenic activity to a series of chlorinated benzothiadiazines. Selected compounds show significant activity to completely ameliorate VEGF-induced endothelial cell proliferation by suppression of VEGFR2 phosphorylation. The scaffold is devoid of activity to inhibit carbonic anhydrases and generally lacks cytotoxicity across a range of cancer and non-malignant cell lines. Assay of activity at 468 kinases shows remarkable selectivity with only four kinases inhibited > 65% at 10 µM concentration, and with significant activity to inhibit TNK2/ACK1 and PKRD2 by > 90%. All four identified kinase targets are known modulators of angiogenesis, thus highlighting compound 17b as a novel angiogenesis inhibitor for further development.

Clinical Study of Anlotinib as Third-Line or Above Therapy in Patients With Advanced or Metastatic Gastric Cancer: A Multicenter Retrospective Study

Background

The present study was conducted to evaluate the efficacy and safety of anlotinib as third-line or above therapy for patients with advanced or metastatic gastric cancer.

Methods

Patients with advanced or metastatic gastric cancer who have failed from second-line treatment and treated with anlotinib monotherapy or combined with chemotherapy or immunotherapy from June 2019 to January 2021 in 3 institutions across China were retrospectively analyzed. The primary end point was progression free survival (PFS). Secondary end points included overall survival (OS), objective response rate (ORR), disease control rate (DCR), and safety.

Results

43 patients with advanced or metastatic gastric cancer who have failed prior treatment received anlotinib monotherapy or combination therapy as third-line or above therapy. In the general population, 4 patients achieved PR, 21 patients had SD and 18 patients had PD. The overall ORR and DCR were 9.3% (4/43) and 58.1% (25/43), respectively. Median PFS and OS were 3.0 months (95% CI=2.5-3.5) and 6.0 months (95% CI=4.4-7.6), respectively. The incidence of Grade 3-4 adverse events(AEs) was 34.9%. Subgroup analysis suggested that the ORR of anlotinib combination therapy was superior than anlotinib monotherapy, but with similar PFS and OS. The clinical benefit of anlotinib was not associated with previously anti-angiogenesis therapy with apatinib.

Conclusions

Anlotinib monotherapy or combination therapy provide a feasible third-line or above therapeutic strategy in patients with advanced or metastatic gastric cancer a median PFS of 3.0 months and median OS of 6.0 months was obtained with well tolerated toxicity.

Combined anticancer therapy with imidazoacridinone C-1305 and paclitaxel in human lung and colon cancer xenografts-Modulation of tumour angiogenesis

The acridanone derivative 5-dimethylaminopropylamino-8-hydroxytriazoloacridinone (C-1305) has been described as a potent inhibitor of cancer cell growth. Its mechanism of action in in vitro conditions was attributed, among others, to its ability to bind and stabilize the microtubule network and subsequently exhibit its tumour-suppressive effects in synergy with paclitaxel (PTX). Therefore, the objective of the present study was to analyse the effects of the combined treatment of C-1305 and PTX in vivo. In addition, considering the results of previous genomic analyses, particular attention was given to the effects of this treatment on tumour angiogenesis. Treatment with C-1305 revealed antitumor effect in A549 lung cancer cells, and combined treatment with PTX showed tendency to anticancer activity in HCT116 colon cancer xenografts. It also improved tumour blood perfusion in both tumour models. The plasma level of CCL2 was increased and that of PDGF was decreased after combined treatment with C-1305 and PTX. The experimental results showed that the levels of FGF1, TGF-β and Ang-4 decreased, whereas the levels of ERK1/2 and Akt phosphorylation increased in HCT116 tumour tissue following combined treatment with both drugs. The results of in vitro capillary-like structure formation assay demonstrated the inhibiting effect of C-1305 on this process. Although previous in vitro and in vivo studies suggested a positive effect of C-1305 on cancer cells, combined treatment of HCT116 human colon and A549 lung cancer cells with both PTX and C-1305 in vivo showed that the antitumor activity was restricted and associated with the modulation of tumour angiogenesis.

Endothelial EphrinB2 Regulates Sunitinib Therapy Response in Murine Glioma

Vascular guidance is critical in developmental vasculogenesis and pathological angiogenesis. Brain tumors are strongly vascularized, and antiangiogenic therapy was anticipated to exhibit a strong anti-tumor effect in this tumor type. However, vascular endothelial growth factor A (VEGFA) specific inhibition had no significant impact in clinical practice of gliomas. More research is needed to understand the failure of this therapeutic approach. EphrinB2 has been found to directly interact with vascular endothelial growth factor receptor 2 (VEGFR2) and regulate its activity. Here we analyzed the expression of ephrinB2 and EphB4 in human glioma, we observed vascular localization of ephrinB2 in physiology and pathology and found a significant survival reduction in patients with elevated ephrinB2 tumor expression. Induced endothelial specific depletion of ephrinB2 in the adult mouse (efnb2i∆EC) had no effect on the quiescent vascular system of the brain. However, we found glioma growth and perfusion altered in efnb2i∆EC animals similar to the effects observed with antiangiogenic therapy. No additional anti-tumor effect was observed in efnb2i∆EC animals treated with antiangiogenic therapy. Our data indicate that ephrinB2 and VEGFR2 converge on the same pathway and intervention with either molecule results in a reduction in angiogenesis.

Strategies to improve the EPR effect: A mechanistic perspective and clinical translation

Many efforts have been made to achieve targeted delivery of anticancer drugs to enhance their efficacy and to reduce their adverse effects. These efforts include the development of nanomedicines as they can selectively penetrate through tumor blood vessels through the enhanced permeability and retention (EPR) effect. The EPR effect was first proposed by Maeda and co-workers in 1986, and since then various types of nanoparticles have been developed to take advantage of the phenomenon with regards to drug delivery. However, the EPR effect has been found to be highly variable and thus unreliable due to the complex tumor microenvironment. Various physical and pharmacological strategies have been explored to overcome this challenge. Here, we review key advances and emerging concepts of such EPR-enhancing strategies. Furthermore, we analyze 723 clinical trials of nanoparticles with EPR enhancers and discuss their clinical translation.

In Vitro, In Vivo, and In Silico Models of Lymphangiogenesis in Solid Malignancies

Simple Summary

Lymphangiogenesis is the formation of new lymphatic vessels in physiological conditions but has also been found to be associated with pathologies. For example, it has been proven to be involved in cancer progression and metastatic dissemination through the body. Thus, it became a key element to study in the management of this widespread disease. To date, the study of lymphangiogenesis takes place at the biological (in vitro and in vivo) and computational (in silico) levels. The association of these complementary fields combined with imaging techniques constitutes a real toolbox in pathological lymphangiogenesis understanding.

Abstract

Lymphangiogenesis (LA) is the formation of new lymphatic vessels by lymphatic endothelial cells (LECs) sprouting from pre-existing lymphatic vessels. It is increasingly recognized as being involved in many diseases, such as in cancer and secondary lymphedema, which most often results from cancer treatments. For some cancers, excessive LA is associated with cancer progression and metastatic dissemination to the lymph nodes (LNs) through lymphatic vessels. The study of LA through in vitro, in vivo, and, more recently, in silico models is of paramount importance in providing novel insights and identifying the key molecular actors in the biological dysregulation of this process under pathological conditions. In this review, the different biological (in vitro and in vivo) models of LA, especially in a cancer context, are explained and discussed, highlighting their principal modeled features as well as their advantages and drawbacks. Imaging techniques of the lymphatics, complementary or even essential to in vivo models, are also clarified and allow the establishment of the link with computational approaches. In silico models are introduced, theoretically described, and illustrated with examples specific to the lymphatic system and the LA. Together, these models constitute a toolbox allowing the LA research to be brought to the next level.

Tumor Budding in Gynecologic Cancer as a Marker for Poor Survival: A Systematic Review and Meta-Analysis of the Perspectives of Epithelial-Mesenchymal Transition

This study aimed to assess the prognostic significance, assessment methods, and molecular features of tumor budding (TB). A literature search of Medline, EMBASE, Cochrane Library, and eleven cohort studies (seven cervical and four endometrial cancers) was conducted. Three assessment methods for TB involving 2009 patients were collected and constituted in the analysis. Our meta-analysis showed that TB was a marker of poor survival, regardless of the cancer origin site or assessment method (overall survival: hazard ratio [HR], 2.40; 95% confidence interval [CI], 1.82-3.17; disease-free survival: HR, 3.32; 95% CI, 2.46-4.48). In endometrial cancers, TB is associated with the epithelial-mesenchymal transition, microvessel density, and decreased hormone receptor expression. Thus, we suggest TB as a poor prognostic marker for all gynecologic cancers.

The p53-Driven Anticancer Effect of Ribes fasciculatum Extract on AGS Gastric Cancer Cells

Cancer metastasis is directly related to the survival rate of cancer patients. Although cancer metastasis proceeds by the movement of cancer cells, it is fundamentally caused by its resistance to anoikis, a mechanism of apoptosis caused by the loss of adhesion of cancer cells. Therefore, it was found that inhibiting cancer migration and reducing anoikis resistance are important for cancer suppression, and natural compounds can effectively control it. Among them, Ribes fasciculatum, which has been used as a medicinal plant, was confirmed to have anticancer potential, and experiments were conducted to prove various anticancer effects by extracting Ribes fasciculatum (RFE). Through various experiments, it was observed that RFE induces apoptosis of AGS gastric cancer cells, arrests the cell cycle, induces oxidative stress, and reduces mobility. It was also demonstrated that anoikis resistance was attenuated through the downregulation of proteins, such as epidermal growth factor receptor (EGFR). Moreover, the anticancer effect of RFE depends upon the increase in p53 expression, suggesting that RFE is suitable for the development of p53-targeted anticancer materials. Moreover, through xenotransplantation, it was found that the anticancer effect of RFE confirmed in vitro was continued in vivo.

Picolylamine-functionalized benz[e]indole squaraine dyes: Synthetic approach, characterization and in vitro efficacy as potential anticancer phototherapeutic agents

Squaraine dyes are a family of compounds known for their relevant photophysical and photochemical properties potentially useful as photosensitizing agents. Since pyridines have been introduced into the skeleton of several families of compounds to enhance their pharmacological activity, and this approach had not yet been performed on squaraines, novel dyes derived from benz[e]indole functionalized with picolyl- and dipicolylamine and N-ethyl and -hexyl chains were designed and synthesized. After being fully characterized, their interaction with human albumin was in vitro and in silico evaluated. Dyes were further assessed for their phototoxicity activity, and the most interesting ones were studied regarding cell localization and induction of morphological cell changes, genotoxicity, apoptosis and cell cycle arrest. The molecules with N-ethyl chains showed the greatest in vitro light-dependent cytotoxic effects, particularly the zwitterionic squaraine dye and the one bearing a single pyridine unit, which also exhibited a more significant interaction with human albumin. Phenotypically, the cells incubated with these squaraines became smaller and rounded after irradiation, the effects varying with the tested concentration. Genotoxic effects were observed even without irradiation, being more evident for the N-ethyl picolylamine-derived dye. The fluorescence emitted by Rhodamine 123 largely coincided with that emitted by the dyes, suggesting that they are found preferentially in mitochondria. After irradiation, an increase in the subG1 population was verified by propidium iodide-staining analysis by flow cytometry, indicative of cell death by apoptosis.

EphrinB2-EphB4 Signaling in Neurooncological Disease

EphrinB2-EphB4 signaling is critical during embryogenesis for cardiovascular formation and neuronal guidance. Intriguingly, critical expression patterns have been discovered in cancer pathologies over the last two decades. Multiple connections to tumor migration, growth, angiogenesis, apoptosis, and metastasis have been identified in vitro and in vivo. However, the molecular signaling pathways are manifold and signaling of the EphB4 receptor or the ephrinB2 ligand is cancer type specific. Here we explore the impact of these signaling pathways in neurooncological disease, including glioma, brain metastasis, and spinal bone metastasis. We identify potential downstream pathways that mediate cancer suppression or progression and seek to understand it´s role in antiangiogenic therapy resistance in glioma. Despite the Janus-faced functions of ephrinB2-EphB4 signaling in cancer Eph signaling remains a promising clinical target.

Immunohistochemistry study of tumor vascular normalization and anti-angiogenic effects of sunitinib versus bevacizumab prior to dose-dense doxorubicin/cyclophosphamide chemotherapy in HER2-negative breast cancer

Purpose

Tumor angiogenesis controlled predominantly by vascular endothelial growth factor and its receptor (VEGF-VEGFR) interaction plays a key role in the growth and propagation of cancer cells. However, the newly formed network of blood vessels is disorganized and leaky. Pre-treatment with anti-angiogenic agents can “normalize” the tumor vasculature allowing effective intra-tumoral delivery of standard chemotherapy. Immunohistochemistry (IHC) analysis was applied to investigate and compare the vascular normalization and anti-angiogenic effects of two commonly used anti-angiogenic agents, Sunitinib and Bevacizumab, administered prior to chemotherapy in HER2-negative breast cancer patients.

Methods

This prospective clinical trial enrolled 38 patients into a sunitinib cohort and 24 into a bevacizumab cohort. All received 4 cycles of doxorubicin/cyclophosphamide chemotherapy and pre-treatment with either sunitinib or bevacizumab. Tumor biopsies were obtained at baseline, after cycle 1 (C1) and cycle 4 (C4) of chemotherapy. IHC was performed to assess the tumor vascular normalization index (VNI), lymphatic vessel density (LVD), Ki67 proliferation index and expression of tumor VEGFR2.

Results

In comparison to Bevacizumab, Sunitinib led to a significant increase in VNI post-C1 and C4 (p < 0.001 and 0.001) along with decrease in LVD post-C1 (p = 0.017). Both drugs when combined with chemotherapy resulted in significant decline in tumor proliferation after C1 and C4 (baseline vs post-C4 Ki67 index p = 0.006 for Sunitinib vs p = 0.021 for Bevacizumab). Bevacizumab resulted in a significant decrease in VEGFR2 expression post-C1 (p = 0.004).

Conclusion

Sunitinib, in comparison to Bevacizumab showed a greater effect on tumor vessel modulation and lymphangiogenesis suggesting that its administration prior to chemotherapy might result in improved drug delivery.

Trial registry

ClinicalTrials.gov: NCT02790580 (first posted June 6, 2016).

Novel Dual-Targeting Antibody Fragment IDB0062 Overcomes Anti-Vascular Endothelial Growth Factor Drug Limitations in Age-Related Macular Degeneration

Purpose

Repeated administration of anti–vascular endothelial growth factor drugs to treat age-related macular degeneration leads to resistance. To overcome this drawback, we developed the novel recombinant dual-targeting antibody fragment IDB0062, which is comprised of the anti–vascular endothelial growth factor A Fab and neuropilin 1-targeting peptide, and we assessed its properties.

Methods

We compared the in vitro activity of IDB0062 and conventional drugs using cell proliferation, wound healing, and Transwell assays. The in vivo efficacy of IDB0062 was determined using mouse choroidal neovascularization and oxygen-induced retinopathy models. To evaluate the ocular distribution of IDB0062, we intravitreally administered IDB0062 and ranibizumab to cynomolgus monkeys and measured the retinal drug levels.

Results

IDB0062 effectively inhibited not only vascular endothelial growth factor A in vitro but also placenta growth factor 2, vascular endothelial growth factor B, and platelet-derived growth factor BB, which induce vascular endothelial growth factor A–independent angiogenesis. In addition, IDB0062 showed non-inferior efficacy compared with aflibercept in vivo despite the low selectivity for mouse vascular endothelial growth factor A. In the monkey intravitreal pharmacokinetic study, IDB0062 improved drug distribution in the retina compared with ranibizumab, confirming the accelerated onset of pharmacological action when IDB0062 is injected in the vitreous humor.

Conclusions

Through neuropilin 1 binding, IDB0062 can improve the efficacy and accelerate the onset of pharmacological action in the posterior segment, which is targeted for macular degeneration, thereby improving drug responsiveness in drug-resistant patients.

Translational Relevance

Considering its novel mechanism of action, IDB0062 may help in controlling resistance to conventional anti–vascular endothelial growth factor drugs in clinical settings.

Translational research in pediatric contrast-enhanced ultrasound

The role of contrast-enhanced ultrasound (CEUS) imaging is being widely explored by various groups for its use in the pediatric population. Clinical implementation of new diagnostic or therapeutic techniques requires extensive and meticulous preclinical testing and evaluation. The impact of CEUS will be determined in part by the extent to which studies are oriented specifically toward a pediatric population. Rather than simply applying principles and techniques used in the adult population, these studies are expected to advance and augment preexisting knowledge with pediatric-specific information. To further develop this imaging modality for use in children, pediatric-focused preclinical research is essential. In this paper we describe the development and implementation of the pediatric-specific preclinical animal and phantom models that are being used to evaluate CEUS with the goal of clinical translation to children.

Haloperidol Metabolite II Valproate Ester (S)-(-)-MRJF22: Preliminary Studies as a Potential Multifunctional Agent Against Uveal Melanoma

Increased angiogenesis and vascular endothelial growth factor (VEGF) levels contribute to higher metastasis and mortality in uveal melanoma (UM), an aggressive malignancy of the eye in adults. (±)-MRJF22, a prodrug of the sigma (σ) ligand haloperidol metabolite II conjugated with the histone deacetylase (HDAC) inhibitor valproic acid, has previously demonstrated a promising antiangiogenic activity. Herein, the asymmetric synthesis of (R)-(+)-MRJF22 and (S)-(-)-MRJF22 was performed to investigate their contribution to (±)-MRJF22 antiangiogenic effects in human retinal endothelial cells (HREC) and to assess their therapeutic potential in primary human uveal melanoma (UM) 92-1 cell line. While both enantiomers displayed almost identical capabilities to reduce cell viability than the racemic mixture, (S)-(-)-MRJF22 exhibited the highest antimigratory effects in endothelial and tumor cells. Given the fundamental contribution of cell motility to cancer progression, (S)-(-)-MRJF22 may represent a promising candidate for novel antimetastatic therapy in patients with UM.

Design and Synthesis of New Quinoxaline Derivatives as Potential Histone Deacetylase Inhibitors Targeting Hepatocellular Carcinoma: In Silico, In Vitro, and SAR Studies

Guided by the structural optimization principle and the promising anticancer effect of the quinoxaline nucleus, a new series of novel HDAC inhibitors were designed and synthesized. The synthesized compounds were designed to bear the reported pharmacophoric features of the HDAC inhibitors in addition to an extra moiety to occupy the non-used vacant deep pocket of the HDAC receptor. The newly prepared compounds were evaluated for their in vitro anti-proliferative activities against HepG-2 and HuH-7 liver cancer cell lines. The tested compounds showed promising anti-proliferative activities against both cell lines. The most active ten candidates (6 c , 6 d , 6 f , 6 g , 6 k , 6 l , 7 b , 8, 10 h , and 12) were further evaluated for their effect on the gene expression levels of Bax as an apoptotic marker and Bcl-2 as an anti-apoptotic one. Moreover, they were evaluated for their ability to inhibit histone deacetylase (HDAC1, HDAC4, and HDAC6) activities. Compound 6 c achieved the best cytotoxic activities on both HepG-2 and HuH-7 cell lines with IC50 values of 1.53 and 3.06 µM, respectively, and also it showed the most inhibitory activities on HDAC1, HDAC4, and HDAC6 with IC50 values of 1.76, 1.39, and 3.46 µM, respectively, compared to suberoylanilide hydroxamic acid (SAHA) as a reference drug (IC50 = 0.86, 0.97, and 0.93 µM, respectively). Furthermore, it achieved a more characteristic arrest in the growth of cell population of HepG-2 at both G0/G1 and S phases with 1.23-, and 1.18-fold, respectively, compared to that of the control, as determined by cell cycle analysis. Also, compound 6 c showed a marked elevation in the AnxV-FITC apoptotic HepG-2 cells percentage in both early and late phases increasing the total apoptosis percentage by 9.98-, and 10.81-fold, respectively, compared to the control. Furthermore, docking studies were carried out to identify the proposed binding mode of the synthesized compounds towards the prospective target (HDAC4). In silico ADMET and toxicity studies revealed that most of the synthesized compounds have accepted profiles of drug-likeness with low toxicity. Finally, an interesting SAR analysis was concluded to help the future design of more potent HDACIs in the future by medicinal chemists.

Iterative Upgrading of Small Molecular Tyrosine Kinase Inhibitors for EGFR Mutation in NSCLC: Necessity and Perspective

Molecular targeted therapy has been reported to have fewer adverse effects, and offer a more convenient route of administration, compared with conventional chemotherapy. With the development of sequencing technology, and research on the molecular biology of lung cancer, especially whole-genome information on non-small cell lung cancer (NSCLC), various therapeutic targets have been unveiled. Among the NSCLC-driving gene mutations, epidermal growth factor receptor (EGFR) mutations are the most common, and approximately 10% of Caucasian, and more than 50% of Asian, NSCLC patients have been found to have sensitive EGFR mutations. A variety of targeted therapeutic agents for EGFR mutations have been approved for clinical applications, or are undergoing clinical trials around the world. This review focuses on: the indications of approved small molecular kinase inhibitors for EGFR mutation-positive NSCLC; the mechanisms of drug resistance and the corresponding therapeutic strategies; the principles of reasonable and precision molecular structure; and the drug development discoveries of next-generation inhibitors for EGFR.

Dental Implant Placement in Patients With a History of Medications Related to Osteonecrosis of the Jaws: A Systematic Review

The present systematic review evaluates the safety of placing dental implants in patients with a history of antiresorptive or antiangiogenic drug therapy. The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines were followed. PubMed, Cochrane Central Register of Controlled Trials, Scopus, Web of Science, and OpenGrey databases were used to search for clinical studies (English only) to July 16, 2019. Study quality was assessed regarding randomization, allocation sequence concealment, blinding, incomplete outcome data, selective outcome reporting, and other biases using a modified Newcastle-Ottawa scale and the Joanna Briggs Institute critical appraisal checklist for case series. A broad search strategy resulted in the identification of 7542 studies. There were 28 studies reporting on bisphosphonates (5 cohort, 6 case control, and 17 case series) and 1 study reporting on denosumab (case series) that met the inclusion criteria and were included in the qualitative synthesis. The quality assessment revealed an overall moderate quality of evidence among the studies. Results demonstrated that patients with a history of bisphosphonate treatment for osteoporosis are not at increased risk of implant failure in terms of osseointegration. However, all patients with a history of bisphosphonate treatment, whether taken orally for osteoporosis or intravenously for malignancy, appear to be at risk of "implant surgery-triggered" medication-related osteonecrosis of the jaw (MRONJ). In contrast, the risk of MRONJ in patients treated with denosumab for osteoporosis was found to be negligible. In conclusion, general and specialist dentists should exercise caution when planning dental implant therapy in patients with a history of bisphosphonate and denosumab drug therapy. Importantly, all patients with a history of bisphosphonates are at risk of MRONJ, necessitating this to be included in the informed consent obtained before implant placement.

Expression and characterization of a novel single-chain anti-vascular endothelial growth factor antibody in the goat milk

Vascular endothelial growth factor (VEGF) has essential functions in angiogenesis, endothelial cell proliferation, migration, and tumor invasion. Different approaches have been developed to suppress tumor angiogenesis, which is considered a hallmark of cancer. Anti-VEGF monoclonal antibodies constitute an important strategy for cancer immunotherapy, which has been produced on several platforms. In this study, a novel single-chain anti-VEGF monoclonal antibody (scVEGFmAb) was produced in the goat mammary gland by adenoviral transduction. scVEGFmAb was purified by affinity chromatography. N-glycans were analyzed by exoglycosidase digestion and hydrophilic interaction ultra-performance liquid chromatography coupled to electrospray ionization mass spectrometry. The biological activity of scVEGFmAb was assessed by scratch and mouse aortic ring assays. scVEGFmAb was produced at 0.61 g/L in the goat milk, and its purification rendered 95 % purity. N-glycans attached to scVEGFmAb backbone were mainly neutral biantennary core fucosylated with Galβ1,4GlcNAc motif, and charged structures were capped with Neu5Ac and Neu5Gc. The chimeric molecule significantly prevented cell migration and suppressed microvessel sprouting. These results demonstrated for the first time the feasibility of producing an anti-VEGF therapeutic antibody in the milk of non-transgenic goats with the potential to counteract tumor angiogenesis.

Anti-angiogenesis in cancer therapeutics: the magic bullet

BACKGROUND

Angiogenesis is the formation of new vascular networks from preexisting ones through the migration and proliferation of differentiated endothelial cells. Available evidence suggests that while antiangiogenic therapy could inhibit tumour growth, the response to these agents is not sustained. The aim of this paper was to review the evidence for anti-angiogenic therapy in cancer therapeutics and the mechanisms and management of tumour resistance to antiangiogenic agents. We also explored the latest advances and challenges in this field. MEDLINE and EMBASE databases were searched for publications on antiangiogenic therapy in cancer therapeutics from 1990 to 2020. Vascular endothelial growth factor (VEGF) is the master effector of the angiogenic response in cancers. Anti-angiogenic agents targeting the VEGF and HIF-α pathways include monoclonal antibodies to VEGF (e.g. bevacizumab), small-molecule tyrosine kinase inhibitors (TKIs) e.g. sorafenib, decoy receptor or VEGF trap e.g. aflibercept and VEGFR2 inhibitors (e.g. ramucirumab). These classes of drugs are vascular targeting which in many ways are advantageous over tumour cell targeting drugs. Their use leads to a reduction in the tumour blood supply and growth of the tumour blood vessels. Tumour resistance and cardiovascular toxicity are important challenges which limit the efficacy and long-term use of anti-angiogenic agents in cancer therapeutics. Tumour resistance can be overcome by dual anti-angiogenic therapy or combination with conventional chemotherapy and immunotherapy. Emerging nanoparticle-based therapy which can silence the expression of HIF-α gene expression by antisense oligonucleotides or miRNAs has been developed. Effective delivery platforms are required for such therapy.

SHORT CONCLUSION

Clinical surveillance is important for the early detection of tumour resistance and treatment failure using reliable biomarkers. It is hoped that the recent interest in mesenchymal cell-based and exosome-based nanoparticle delivery platforms will improve the cellular delivery of newer anti-angiogenics in cancer therapeutics.

Natural Products as a Promising Therapeutic Strategy to Target Cancer Stem Cells

Cancer is still a deadly disease, and its treatment desperately needs to be managed in a very sophisticated way through fast-developing novel strategies. Most of the cancer cases eventually develop into recurrencies, for which cancer stem cells (CSCs) are thought to be responsible. They are considered as a subpopulation of all cancer cells of tumor tissue with aberrant regulation of self-renewal, unbalanced proliferation, and cell death properties. Moreover, CSCs show a serious degree of resistance to chemotherapy or radiotherapy and immune surveillance as well. Therefore, new classes of drugs are rushing into the market each year, which makes the cost of therapy increase dramatically. Natural products are also becoming a new research area as a diverse chemical library to suppress CSCs. Some of the products even show promise in this regard. So, the near future could witness the introduction of natural products as a source of new chemotherapy modalities, which may result in the development of novel anticancer drugs. They could also be a reasonably-priced alternative to highly expensive current treatments. Nowadays, considering the effects of natural compounds on targeting surface markers, signaling pathways, apoptosis, and escape from immunosurveillance have been a highly intriguing area in preclinical and clinical research. In this review, we present scientific advances regarding their potential use in the inhibition of CSCs and the mechanisms by which they kill the CSCs.

Phytochemicals in Chemoprevention: A Cost-Effective Complementary Approach

Cancer is one of the leading causes of death across the world. Although conventional cancer treatments such as chemotherapy and radiotherapy have effectively decreased cancer progression, they come with many dose-limiting side-effects. Phytochemicals that naturally occur in spices, fruits, vegetables, grains, legumes, and other common foods are surprisingly effective complements to conventional cancer treatments. These biologically active compounds demonstrate anticancer effects via cell signaling pathway interference in cancerous cells. In addition, phytochemicals protect non-cancerous cells from chemotherapy-induced side-effects. This paper addresses the not only the potential of phytochemicals quercetin, isoflavones, curcumin, catechins, and hesperidin in terms of cancer treatment and protection against side-effects of chemotherapy, but also methods for increasing phytochemical bioavailability.

Targeting HIF-1α by newly synthesized Indolephenoxyacetamide (IPA) analogs to induce anti-angiogenesis-mediated solid tumor suppression

BACKGROUND

Hypoxic microenvironment is a common feature of solid tumors, which leads to the promotion of cancer. The transcription factor, HIF-1α, expressed under hypoxic conditions stimulates tumor angiogenesis, favoring HIF-1α as a promising anticancer agent. On the other hand, synthetic Indolephenoxyacetamide derivatives are known for their pharmacological potentiality. With this background here, we have synthesized, characterized, and validated the new IPA (8a-n) analogs for anti-tumor activity.

METHODS

The new series of IPA (8a-n) were synthesized through a multi-step reaction sequence and characterized based on the different spectroscopic analysis FT-IR, ¹H, ¹³C NMR, mass spectra, and elemental analyses. Cell-based screening of IPA (8a-n) was assessed by MTT assay. Anti-angiogenic efficacy of IPA (8k) validated through CAM, Rat corneal, tube formation and migration assay. The underlying molecular mechanism is validated through zymogram and IB studies. The in vivo anti-tumor activity was measured in the DLA solid tumor model.

RESULTS

Screening for anti-proliferative studies inferred, IPA (8k) is a lead molecule with an IC₅₀ value of _˜5 μM. Anti-angiogenic assays revealed the angiopreventive activity through inhibition of HIF-1α and modulation downstream regulatory genes, VEGF, MMPs, and P53. The results are confirmative in an in vivo solid tumor model.

CONCLUSION

The IPA (8k) is a potent anti-proliferative molecule with anti-angiogenic activity and specifically targets HIF1α, thereby modulates its downstream regulatory genes both in vitro and in vivo. The study provides scope for new target-specific drug development against HIF-1α for the treatment of solid tumors.

Nanomaterials for Antiangiogenic Therapies for Cancer: A Promising Tool for Personalized Medicine

Angiogenesis is one of the hallmarks of cancer. Several studies have shown that vascular endothelium growth factor (VEGF) plays a leading role in angiogenesis progression. Antiangiogenic medication has gained substantial recognition and is commonly administered in many forms of human cancer, leading to a rising interest in cancer therapy. However, this treatment method can lead to a deteriorating outcome of resistance, invasion, distant metastasis, and overall survival relative to its cytotoxicity. Furthermore, there are significant obstacles in tracking the efficacy of antiangiogenic treatments by incorporating positive biomarkers into clinical settings. These shortcomings underline the essential need to identify additional angiogenic inhibitors that target numerous angiogenic factors or to develop a new method for drug delivery of current inhibitors. The great benefits of nanoparticles are their potential, based on their specific properties, to be effective mechanisms that concentrate on the biological system and control various important functions. Among various therapeutic approaches, nanotechnology has emerged as a new strategy for treating different cancer types. This article attempts to demonstrate the huge potential for targeted nanoparticles and their molecular imaging applications. Notably, several nanoparticles have been developed and engineered to demonstrate antiangiogenic features. This nanomedicine could effectively treat a number of cancers using antiangiogenic therapies as an alternative approach. We also discuss the latest antiangiogenic and nanotherapeutic strategies and highlight tumor vessels and their microenvironments.

Optimizing Survival and the Changing Landscape of Targeted Therapy for Intermediate and Advanced Hepatocellular Carcinoma: A Systematic Review

BACKGROUND

Systemic therapy for hepatocellular carcinoma (HCC) consisting of the tyrosine kinase inhibitor sorafenib has remained unchanged for over a decade, although results from phase III targeted therapy trials have recently emerged. This review considers available phase III evidence on the use and sequencing of targeted therapy for intermediate and advanced non-locoregional therapy (LRT) eligible HCC and discusses implications for clinical practice.

METHODS

Published and presented literature on phase III data reporting on targeted therapy for advanced HCC that was not eligible for loco-regional therapies was identified using the key search terms "hepatocellular cancer" AND "advanced" AND "targeted therapy" AND "phase III" OR respective aliases (PRISMA).

RESULTS

Ten phase III trials assessed targeted therapy first-line and eight following sorafenib. In the first-line, atezolizumab plus bevacizumab statistically significantly improved overall survival (OS) and patient-reported outcomes (PROs) compared with sorafenib, while lenvatinib demonstrated non-inferior OS. Following progression on sorafenib, statistically significant OS improvements over placebo were seen for cabozantinib and regorafenib in unselected patients and for ramucirumab in those with baseline α-fetoprotein≥400 ng/mL. Based on improved OS and PROs, atezolizumab plus bevacizumab appears to be a preferred first-line treatment option for intermediate or advanced non-LRT eligible HCC. Phase III data informing sequencing of later lines of treatment is lacking. Therefore, sequencing principles are proposed that can be used to guide treatment selection.

CONCLUSIONS

Ongoing trials will continue to inform optimal therapy. Multiple targeted therapies have improved OS in intermediate or advanced non-LRT eligible HCC, although optimal sequencing is an area of ongoing investigation.

The effects of vascularization on tumor development: A systematic review and meta-analysis of pre-clinical studies

PURPOSE

This review aimed to systematize and quantify the existing evidence about the effect of tumor vascularization on its growth, in preclinical studies.

METHODOLOGY

A computerized research on databases PubMed, Scopus and EBSCO was performed to identify studies that evaluate both the vascularization parameters and the development of the tumors in animal models and the mean differences were calculated through a random effects model.

RESULTS

Thirteen studies met the inclusion criteria and were included in the systematic review, of which, 6 studies were included in the meta-analysis. Besides tumor vascular density that all studies evaluated, 3 studies analysed the tumor perfusion, 2 studies the tumor hypoxia and 3 studies assessed the grade of vessel maturation. Most of the studies (11) related decreased tumor vascularization and a concomitant inhibition of tumor growth or metastasis development. Quantitatively, the decrease in tumor vascularization contributed to a significant decrease in the tumor growing rate of 5.23 (-9.20, -1.26).

CONCLUSION

A reduced level of tumor vascularization seems to be able to inhibit tumor growth and progression.

Endothelial Cells as Tools to Model Tissue Microenvironment in Hypoxia-Dependent Pathologies

Endothelial cells (ECs) lining the blood vessels are important players in many biological phenomena but are crucial in hypoxia-dependent diseases where their deregulation contributes to pathology. On the other hand, processes mediated by ECs, such as angiogenesis, vessel permeability, interactions with cells and factors circulating in the blood, maintain homeostasis of the organism. Understanding the diversity and heterogeneity of ECs in different tissues and during various biological processes is crucial in biomedical research to properly develop our knowledge on many diseases, including cancer. Here, we review the most important aspects related to ECs’ heterogeneity and list the available in vitro tools to study different angiogenesis-related pathologies. We focus on the relationship between functions of ECs and their organo-specificity but also point to how the microenvironment, mainly hypoxia, shapes their activity. We believe that taking into account the specific features of ECs that are relevant to the object of the study (organ or disease state), especially in a simplified in vitro setting, is important to truly depict the biology of endothelium and its consequences. This is possible in many instances with the use of proper in vitro tools as alternative methods to animal testing.

An overview of the tumor microenvironment, from cells to complex networks (Review)

For a long period, cancer has been believed to be a gene disease, in which oncogenic and suppressor mutations accumulate gradually, finally leading to the malignant transformation of cells. This vision has changed in the last few years, the involvement of the tumor microenvironment, the non-malignant part of the tumors, as an important contributor to the malignant growth being now largely recognized. There is a consensus according to which the understanding of the tumor microenvironment is important as a means to develop new approaches in the therapy of cancer. In this context, the present study is a review of the different types of non-malignant cells that can be found in tumors, with their pro or antitumoral actions, presence in tumors and therapeutic targeting. These cells establish complex relations between them, through cytokines, exosomes, cell adhesion, co-stimulation and co-inhibition; these relations will also be examined in the present work.

Role of Regular Physical Exercise in Tumor Vasculature: Favorable Modulator of Tumor Milieu

The tumor vessel network has been investigated as a precursor of an inhospitable tumor microenvironment, including its repercussions in tumor perfusion, oxygenation, interstitial fluid pressure, pH, and immune response. Dysfunctional tumor vasculature leads to the extravasation of blood to the interstitial space, hindering proper perfusion and causing interstitial hypertension. Consequently, the inadequate delivery of oxygen and clearance of by-products of metabolism promote the development of intratumoral hypoxia and acidification, hampering the action of immune cells and resulting in more aggressive tumors. Thus, pharmacological strategies targeting tumor vasculature were developed, but the overall outcome was not satisfactory due to its transient nature and the higher risk of hypoxia and metastasis. Therefore, physical exercise emerged as a potential favorable modulator of tumor vasculature, improving intratumoral vascularization and perfusion. Indeed, it seems that regular exercise practice is associated with lasting tumor vascular maturity, reduced vascular resistance, and increased vascular conductance. Higher vascular conductance reduces intratumoral hypoxia and increases the accessibility of circulating immune cells to the tumor milieu, inhibiting tumor development and improving cancer treatment. The present paper describes the implications of abnormal vasculature on the tumor microenvironment and the underlying mechanisms promoted by regular physical exercise for the re-establishment of more physiological tumor vasculature.

Vascular disrupting agents in cancer therapy

Tumor blood vessel formation is a key process for tumor expansion. Tumor vessels are abnormal and differ from normal vessels in architecture and components. Besides oxygen and nutrients supply, the tumor vessels system, due to its abnormality, is responsible for: hypoxia formation, and metastatic routes. Tumor blood vessels can be a target of anti-cancer therapies. There are two types of therapies that target tumor vessels. The first one is the inhibition of the angiogenesis process. However, the inhibition is often ineffective because of alternative angiogenesis mechanism activation. The second type is a specific targeting of existing tumor blood vessels by vascular disruptive agents (VDAs). There are three groups of VDAs: microtubule destabilizing drugs, flavonoids with anti-vascular functions, and tumor vascular targeted drugs based on endothelial cell receptors. However, VDAs possess some limitations. They may be cardiotoxic and their application in therapy may leave viable residual, so called, rim cells on the edge of the tumor. However, it seems that a well-designed combination of VDAs with other anti-cancer drugs may bring a significant therapeutic effect. In this article, we describe three groups of vascular disruptive agents with their advantages and disadvantages. We mention VDAs clinical trials. Finally, we present the current possibilities of VDAs combination with other anti-cancer drugs.

Preclinical Efficacy and Safety of an Anti-Human VEGFA and Anti-Human NRP1 Dual-Targeting Bispecific Antibody (IDB0076)

Although bevacizumab (Avastin^®) has been approved as an antiangiogenic agent against some cancers, the efficacy is transient and unsatisfactory in other cancers most likely owing to the presence of alternative proangiogenic factors. Therefore, simultaneous blocking of several proangiogenic factors may be a promising strategy for antiangiogenic cancer therapeutics. Accordingly, neuropilin-1 (NRP1) is an attractive target because it serves as a multifunctional receptor for the vascular endothelial growth factor (VEGF) family. Here, we aimed to generate and test an anti-VEGFA and anti-NRP1 dual-targeting bispecific antibody (named as IDB0076) by genetic fusion of an NRP1-targeting peptide to the C-terminus of the bevacizumab heavy chain. Similar to the parental antibody (bevacizumab), IDB0076 suppressed VEGFA-induced migration of human endothelial cells. In contrast, IDB0076 inhibited endothelial-cell migration induced by other angiogenesis growth factors and manifested a more potent antitumor activity than that of bevacizumab in a murine tumor xenograft model. When toxicity was preliminarily evaluated in cynomolgus monkeys, IDB0076 showed no substantial adverse effects, e.g., the absence of noticeable nephrotoxicity, which has previously been documented for the combination therapy of bevacizumab and an anti-NRP1 antibody. Thus, VEGFA-and-NRP1 dual-targeting bispecific antibody IDB0076 may be a potent and safe anticancer agent worthy of further preclinical and clinical studies.

TRF2 and VEGF-A: an unknown relationship with prognostic impact on survival of colorectal cancer patients

BACKGROUND

Colorectal cancer is one of most common tumors in developed countries and, despite improvements in treatment and diagnosis, mortality rate of patients remains high, evidencing the urgent need of novel biomarkers to properly identify colorectal cancer high-risk patients that would benefit of specific treatments. Recent works have demonstrated that the telomeric protein TRF2 is over-expressed in colorectal cancer and it promotes tumor formation and progression through extra-telomeric functions. Moreover, we and other groups evidenced, both in vitro on established cell lines and in vivo on tumor bearing mice, that TRF2 regulates the vascularization mediated by VEGF-A. In the present paper, our data evidence a tight correlation between TRF2 and VEGF-A with prognostic relevance in colorectal cancer patients.

METHODS

For this study we sampled 185 colorectal cancer patients surgically treated and diagnosed at the Regina Elena National Cancer Institute of Rome and investigated the association between the survival outcome and the levels of VEGF-A and TRF2.

RESULTS

Tissue microarray immunohistochemical analyses revealed that TRF2 positively correlates with VEGF-A expression in our cohort of patients. Moreover, analysis of patients' survival, confirmed in a larger dataset of patients from TCGA, demonstrated that co-expression of TRF2 and VEGF-A correlate with a poor clinical outcome in stage I-III colorectal cancer patients, regardless the mutational state of driver oncogenes.

CONCLUSIONS

Our results permitted to identify the positive correlation between high levels of TRF2 and VEGF-A as a novel prognostic biomarker for identifying the subset of high-risk colorectal cancer patients that could benefit of specific therapeutic regimens.

Pericyte in Oral Squamous Cell Carcinoma: A Systematic Review

The microenvironment of oral cancer is highly dynamic and has been proved to affect tumor progression. Pericytes are blood vessels surrounding cells that have recently gained attention for their roles in vascular and cancer biology. The objective of the present study was to survey the scientific literature for conclusive evidence about whether pericytes are part of blood vessels in oral squamous cell carcinoma (OSCC) and their roles in the tumor microenvironment and clinical outcomes. A systematic electronic search was undertaken in Medline Ovid, PubMed, Web of Science, and Scopus. Eligibility criteria were: publications adopting in vivo models of OSCC that included pericyte detection and assessment by pericyte markers (e.g., α-smooth muscle actin, neuron-glial antigen 2 and platelet-derived growth factor receptor-β). The search yielded seven eligible studies (from 2008 to 2018). The markers most commonly used for pericyte detection were α-smooth muscle actin and neuron-glial antigen 2. The studies reviewed showed the presence of immature vessels exhibiting a reduction of pericyte coverage in OSCC and indicated that anti-cancer therapies could contribute to vessel normalization and pericyte regain. The pericyte population is significantly affected during OSCC development and cancer therapy. While these findings might suggest a role for pericytes in OSCC progression, the limited data available do not allow us to conclude whether they modify the tumor microenvironment and clinical outcome.

In silico analysis of hypoxia activated prodrugs in combination with anti angiogenic therapy through nanocell delivery

Tumour hypoxia is a well-studied phenomenon with implications in cancer progression, treatment resistance, and patient survival. While a clear adverse prognosticator, hypoxia is also a theoretically ideal target for guided drug delivery. This idea has lead to the development of hypoxia-activated prodrugs (HAPs): a class of chemotherapeutics which remain inactive in the body until metabolized within hypoxic regions. In theory, these drugs have the potential for increased tumour selectivity and have therefore been the focus of numerous preclinical studies. Unfortunately, HAPs have had mixed results in clinical trials, necessitating further study in order to harness their therapeutic potential. One possible avenue for the improvement of HAPs is through the selective application of anti angiogenic agents (AAs) to improve drug delivery. Such techniques have been used in combination with other conventional chemotherapeutics to great effect in many studies. A further benefit is theoretically achieved through nanocell administration of the combination, though this idea has not been the subject of any experimental or mathematical studies to date. In the following, a mathematical model is outlined and used to compare the predicted efficacies of separate vs. nanocell administration for AAs and HAPs in tumours. The model is experimentally motivated, both in mathematical form and parameter values. Preliminary results of the model are highlighted throughout which qualitatively agree with existing experimental evidence. The novel prediction of our model is an improvement in the efficacy of AA/HAP combination therapies when administered through nanocells as opposed to separately. While this study specifically models treatment on glioblastoma, similar analyses could be performed for other vascularized tumours, making the results potentially applicable to a range of tumour types.

Tumour hypoxia is a well-documented phenomenon with adverse effects for the progression of the cancer. Accordingly, various therapeutic strategies have emerged in recent years to combat its effects. Herein, we present an experimentally-motivated mathematical model used to assess the feasibility of the therapeutic combination of anti angiogenic agents with hypoxia-activated prodrugs. Analysis of the combination therapy shows that delivery through drug nanocells provides the optimal anticancer effect: a novel result which should inspire further examination.

Angiogenesis in Breast Cancer Progression, Diagnosis, and Treatment

Angiogenesis is a significant event in a wide range of healthy and diseased conditions. This process frequently involves vasodilation and an increase in vascular permeability. Numerous players referred to as angiogenic factors, work in tandem to facilitate the outgrowth of endothelial cells (EC) and the consequent vascularity. Conversely, angiogenic factors could also feature in pathological conditions. Angiogenesis is a critical factor in the development of tumors and metastases in numerous cancers. An increased level of angiogenesis is associated with decreased survival in breast cancer patients. Therefore, a good understanding of the angiogenic mechanism holds a promise of providing effective treatments for breast cancer progression, thereby enhancing patients' survival. Disrupting the initiation and progression of this process by targeting angiogenic factors such as vascular endothelial growth factor (Vegf)-one of the most potent member of the VEGF family- or by targeting transcription factors, such as Hypoxia-Inducible Factors (HIFs) that act as angiogenic regulators, have been considered potential treatment options for several types of cancers. The objective of this review is to highlight the mechanism of angiogenesis in diseases, specifically its role in the progression of malignancy in breast cancer, as well as to highlight the undergoing research in the development of angiogenesis-targeting therapies.