Anti-angiogenic peptides application in cancer therapy; a review

The Influence of Cholesterol on Membrane Targeted Bioactive Peptides: Modulating Peptide Activity Through Changes in Bilayer Biophysical Properties

Cholesterol is a biological molecule that is essential for cellular life. It has unique features in terms of molecular structure and function, and plays an important role in determining the structure and properties of cell membranes. One of the most recognized functions of cholesterol is its ability to increase the level of lipid packing and rigidity of biological membranes while maintaining high levels of lateral mobility of the bulk lipids, which is necessary to sustain biochemical signaling events. There is increased interest in designing bioactive peptides that can act as effective antimicrobial agents without causing harm to human cells. For this reason, it becomes relevant to understand how cholesterol can affect the interaction between bioactive peptides and lipid membranes, in particular by modulating the peptides' ability to penetrate and disrupt the membranes through these changes in membrane rigidity. Here we discuss cholesterol and its role in modulating lipid bilayer properties and discuss recent evidence showing how cholesterol modulates bioactive peptides to different degrees.

A distinct subset of urothelial cells with enhanced EMT features promotes chemotherapy resistance and cancer recurrence by increasing COL4A1-ITGB1 mediated angiogenesis

Drug resistance and tumor recurrence remain clinical challenges in the treatment of urothelial carcinoma (UC). However, the underlying mechanism is not fully understood. Here, we performed single-cell RNA sequencing and identified a subset of urothelial cells with epithelial-mesenchymal transition (EMT) features (EMT-UC), which is significantly correlated with chemotherapy resistance and cancer recurrence. To validate the clinical significance of EMT-UC, we constructed EMT-UC like cells by introducing overexpression of two markers, Zinc Finger E-Box Binding Homeobox 1 (ZEB1) and Desmin (DES), and examined their histological distribution characteristics and malignant phenotypes. EMT-UC like cells were mainly enriched in UC tissues from patients with adverse prognosis and exhibited significantly elevated EMT, migration and gemcitabine tolerance in vitro. However, EMT-UC was not specifically identified from tumorous tissues, certain proportion of them were also identified in adjacent normal tissues. Tumorous EMT-UC highly expressed genes involved in malignant behaviors and exhibited adverse prognosis. Additionally, tumorous EMT-UC was associated with remodeled tumor microenvironment (TME), which exhibited high angiogenic and immunosuppressive potentials compared with the normal counterparts. Furthermore, a specific interaction of COL4A1 and ITGB1 was identified to be highly enriched in tumorous EMT-UC, and in the endothelial component. Targeting the interaction of COL4A1 and ITGB1 with specific antibodies significantly suppressed tumorous angiogenesis and alleviated gemcitabine resistance of UC. Overall, our findings demonstrated that the driven force of chemotherapy resistance and recurrence of UC was EMT-UC mediated COL4A1-ITGB1 interaction, providing a potential target for future UC treatment.

Anti-angiogenic biomolecules in neovascular age-related macular degeneration; therapeutics and drug delivery systems

Blindness in the elderly is often caused by age-related macular degeneration (AMD). The advanced type of AMD known as neovascular AMD (nAMD) has been linked to being the predominant cause of visual impairment in these people. Multiple neovascular structures including choroidal neovascular (CNV) membranes, fluid exudation, hemorrhages, and subretinal fibrosis, are diagnostic of nAMD. These pathological alterations ultimately lead to anatomical and visual loss. It is known that vascular endothelial growth factor (VEGF), a type of proangiogenic factor, mediates the pathological process underlying nAMD. Therefore, various therapies have evolved to directly target the disease. In this review article, an attempt has been made to discuss general explanations about this disease, all common treatment methods based on anti-VEGF drugs, and the use of drug delivery systems in the treatment of AMD. Initially, the pathophysiology, angiogenesis, and different types of AMD were described. Then we described current treatments and future treatment prospects for AMD and outlined the advantages and disadvantages of each. In this context, we first examined the types of therapeutic biomolecules and anti-VEGF drugs that are used in the treatment of AMD. These biomolecules include aptamers, monoclonal antibodies, small interfering RNAs, microRNAs, peptides, fusion proteins, nanobodies, and other therapeutic biomolecules. Finally, we described drug delivery systems based on liposomes, nanomicelles, nanoemulsions, nanoparticles, cyclodextrin, dendrimers, and composite vehicles that are used in AMD therapy.

[Inhibitory Effect of Ginsenoside Rg3 Combined With 5-Fluorouracil on Tumor Angiogenesis and Tumor Growth of Colon Cancer in Mice: An Experimental Study]

Objective

To evaluate the inhibitory effect of ginsenoside Rg3 combined with 5-fluorouracil (5-FU) on tumor angiogenesis and tumor growth in colon cancer in mice.

Methods

CT26 mouse model of colon cancer was established and the mice were randomly assigned to the control group, the ginsenoside Rg3 group, the 5-FU group, and the Rg3 combined with 5-FU group. The 5-FU group was injected intraperitoneally at the dose of 20 mg/kg, 0.2 mL/animal, and once a day for 10 days. Treatment for the Rg3 group was given at the dose of 20 mg/kg, 0.2 mL/animal, and once a day for 21 days via gastric gavage. The dose and the mode of treatment for the Rg3+5-FU combination group were the same as those for the 5-FU and the Rg3 group. The control group was intraperitoneally injected with 0.2 mL/d of normal saline for 10 days. The expression of vascular endothelial growth factor (VEGF) and CD31 and the microvascular density (MVD) of the tumor tissues were examined by immunohistochemistry. The blood flow signals and tumor necrosis were examined by color Doppler flow imaging (CDFI). The quality of life, survival rate, tumor volume, tumor mass, and tumor inhibition rate of the mice were monitored.

Results

After 21 days of treatment, the tumor volume and the tumor mass of all treatment groups were significantly decreased compared with those the control group, with the combination treatment group exhibiting the most significant decrease. The tumor inhibition rates of the Rg3 group, the 5-FU group, and the combination group were 29.96%, 68.78%, and 73.42%, respectively. Rg3 treatment alone had inhibitory effect on tumor growth to a certain degree, while 5-FU treatment alone or 5-FU combined with Rg3 had a stronger inhibitory effect on tumor growth. The tumor inhibition rate of the combination group was higher than that of the 5-FU group, but the difference was not statistically significant (P>0.05). Color Doppler ultrasound showed that there were multiple localized and large tumor necrotic areas that were obvious and observable in the Rg3 group and the combination group, and that there were only small tumor necrotic areas in the 5-FU group and the control group. The tumor necrosis rate of the combination group was (55.63±3.12)%, which was significantly higher than those of the other groups (P<0.05). CDFI examination of the blood flow inside of the tumor of the mice showed that the blood flow signals in the combination group were mostly grade 0-Ⅰ, and that the blood flow signals in the control group were the most abundant, being mostly grade Ⅱ-Ⅲ. The abundance of the blood flow signals in the Rg3 and 5-FU groups were between those of the control group and the combination group. Compared with those of the control group, the expression levels of MVD and VEGF in the tumor tissues of the Rg3 group, the 5-FU group, and the combination group were significantly decreased, with the combination group showing the most significant decrease (P<0.05). HE staining results indicated that there was significant tumor necrosis in mice in the control group and that there were more blood vessels. In contrast, in the tumor of the Rg3 group and the 5-FU group, there were fewer blood vessels and necrotic gaps appeared within the tumors. In the combination group, the tumor tissues had the fewest blood vessels and rope-like necrosis was observed. The mice started dying on the 18th day after treatment started, and all the mice in the control group died on the 42nd day. By this time, there were 3, 5, and 7 mice still alive in the Rg3 group, the 5-FU group, and the combination group, respectively, presenting a survival rate of 30%, 50%, and 70%, respectively. All mice in all the groups died on day 60 after treatment started.

Conclusion

Ginsenoside Rg3 combined with 5-FU can significantly inhibit tumor angiogenesis and tumor growth of colon cancer in mice and improve the survival and quality of life of tumor-bearing mice.

Recent advances and applications of peptide-agent conjugates for targeting tumor cells

BACKGROUND

Cancer, being a complex disease, presents a major challenge for the scientific and medical communities. Peptide therapeutics have played a significant role in different medical practices, including cancer treatment.

METHOD

This review provides an overview of the current situation and potential development prospects of anticancer peptides (ACPs), with a particular focus on peptide vaccines and peptide-drug conjugates for cancer treatment.

RESULTS

ACPs can be used directly as cytotoxic agents (molecularly targeted peptides) or can act as carriers (guiding missile) of chemotherapeutic agents and radionuclides by specifically targeting cancer cells. More than 60 natural and synthetic cationic peptides are approved in the USA and other major markets for the treatment of cancer and other diseases. Compared to traditional cancer treatments, peptides exhibit anticancer activity with high specificity and the ability to rapidly kill target cancer cells. ACP's target and kill cancer cells via different mechanisms, including membrane disruption, pore formation, induction of apoptosis, necrosis, autophagy, and regulation of the immune system. Modified peptides have been developed as carriers for drugs, vaccines, and peptide-drug conjugates, which have been evaluated in various phases of clinical trials for the treatment of different types of solid and leukemia cancer.

CONCLUSIONS

This review highlights the potential of ACPs as a promising therapeutic option for cancer treatment, particularly through the use of peptide vaccines and peptide-drug conjugates. Despite the limitations of peptides, such as poor metabolic stability and low bioavailability, modified peptides show promise in addressing these challenges. Various mechanism of action of anticancer peptides. Modes of action against cancer cells including: inducing apoptosis by cytochrome c release, direct cell membrane lysis (necrosis), inhibiting angiogenesis, inducing autophagy-mediated cell death and immune cell regulation.

Sanikovich V, S. Rusanov A, N. Pirogova Y, Boroda A, Rozhkov A, Kemfang Ngowa JD, N. Bagmet L, I. Sekacheva M. Angiogenesis in Lung Cancer: Understanding the Roles of Growth Factors

Research has shown the role of growth factors in lung cancer angiogenesis. Angiogenesis promotes lung cancer progression by stimulating tumor growth, enhancing tumor invasion, contributing to metastasis, and modifying immune system responses within the tumor microenvironment. As a result, new treatment techniques based on the anti-angiogenic characteristics of compounds have been developed. These compounds selectively block the growth factors themselves, their receptors, or the downstream signaling pathways activated by these growth factors. The EGF and VEGF families are the primary targets in this approach, and several studies are being conducted to propose anti-angiogenic drugs that are increasingly suitable for the treatment of lung cancer, either as monotherapy or as combined therapy. The efficacy of the results are encouraging, but caution must be placed on the higher risk of toxicity, outlining the importance of personalized follow-up in the management of these patients.

Polypharmacological Cell-Penetrating Peptides from Venomous Marine Animals Based on Immunomodulating, Antimicrobial, and Anticancer Properties

Complex pathological diseases, such as cancer, infection, and Alzheimer's, need to be targeted by multipronged curative. Various omics technologies, with a high rate of data generation, demand artificial intelligence to translate these data into druggable targets. In this study, 82 marine venomous animal species were retrieved, and 3505 cryptic cell-penetrating peptides (CPPs) were identified in their toxins. A total of 279 safe peptides were further analyzed for antimicrobial, anticancer, and immunomodulatory characteristics. Protease-resistant CPPs with endosomal-escape ability in Hydrophis hardwickii, nuclear-localizing peptides in Scorpaena plumieri, and mitochondrial-targeting peptides from Synanceia horrida were suitable for compartmental drug delivery. A broad-spectrum S. horrida-derived antimicrobial peptide with a high binding-affinity to bacterial membranes was an antigen-presenting cell (APC) stimulator that primes cytokine release and naïve T-cell maturation simultaneously. While antibiofilm and wound-healing peptides were detected in Synanceia verrucosa, APC epitopes as universal adjuvants for antiviral vaccination were in Pterois volitans and Conus monile. Conus pennaceus-derived anticancer peptides showed antiangiogenic and IL-2-inducing properties with moderate BBB-permeation and were defined to be a tumor-homing peptide (THP) with the ability to inhibit programmed death ligand-1 (PDL-1). Isoforms of RGD-containing peptides with innate antiangiogenic characteristics were in Conus tessulatus for tumor targeting. Inhibitors of neuropilin-1 in C. pennaceus are proposed for imaging probes or therapeutic delivery. A Conus betulinus cryptic peptide, with BBB-permeation, mitochondrial-targeting, and antioxidant capacity, was a stimulator of anti-inflammatory cytokines and non-inducer of proinflammation proposed for Alzheimer's. Conclusively, we have considered the dynamic interaction of cells, their microenvironment, and proportional-orchestrating-host- immune pathways by multi-target-directed CPPs resembling single-molecule polypharmacology. This strategy might fill the therapeutic gap in complex resistant disorders and increase the candidates' clinical-translation chance.

Pramod S, T. Prabhakar B, B.N. Naika M, G. Thippeswamy T, Niranjana P. Characterization and biochemical activities of novel functional antimicrobial peptide (AMP) from Trichogramma chilonis

Introduction and Aim: The antimicrobial peptides (AMPs) are generally found in invertebrates, mammals, birds, plants and insects. AMPs produced by insect parasitoids contribute to innate immunity to resist infection due to lack of adaptive immunity. T. chilonis is one of the most effective endoparasitoid wasps for controlling lepidopterous insects. Several attempts have been made to isolate, characterize and develop a commercially viable product of AMPs from various insect sources. The present study aimed to characterize AMP from T. chilonis for potential antimicrobial and anti-cancer properties.    Methods: AMP was identified through T. chilonis transcriptome sequence and designed in silico and synthesized. Its purity was quantified using RP-HPLC, and the mass identified by mass spectrophotometry. LC/MS-MS was employed to predict the sequence and the BLAST program used to compare the sequence. AMP was tested for haemolytic activity and antimicrobial activity. Two pathogenic bacteria and fungal strains were used and IC50 values and MIC values were predicted against microbial strains.    Results: Synthetic peptide was found to be 95% homogenous with molecular weight of 3.48 kD.  The peptide was identified to be a novel antimicrobial peptide consisting of 33 amino acid residues, and has a low computed instability index of -0.1.55 with high hydrophobic ratio of 27.27%. The antimicrobial activity revealed that T. chilonis antimicrobial peptide (TC-AMP) strongly inhibits the growth of selected human bacterial and fungal pathogens. While the haemolytic assay showed that the peptide did not obliterate human RBC in vitro. TC-AMP also showed an efficient inhibition of angiogenesis by in vivo model as evident by inhibition of vascularization.   Conclusions: AMP derived from the parasitoid has a potent antibiotic and anti-angiogenesis property. The peptide can be used as a potential antimicrobial and anticancer drug in near future with more detailed studies on its targeted applications.

Preparation, In Vitro Affinity, and In Vivo Biodistribution of Receptor-Specific 68Ga-Labeled Peptides Targeting Vascular Endothelial Growth Factor Receptors

As angiogenesis plays a key role in tumor growth and metastasis, the angiogenic process has attracted scientific interest as a target for diagnostic and therapeutic agents. Factors influencing angiogenesis include the vascular endothelial growth factor (VEGF) family and the two associated receptor types (VEGFR-1 and VEGFR-2). VEGFR-1/-2 detection and quantification in cancer lesions are essential for tumor process management. As a result of the advantageous pharmacokinetics and image contrast, peptides radiolabeled with PET emitters have become interesting tools for the visualization of VEGFR-1/-2-positive tumors. In this study, we prepared ⁶⁸Ga-labeled peptides containing 15 (peptide 1) and 23 (peptide 2) amino acids as new PET tracers for tumor angiogenic process imaging.

METHODS

The peptides were conjugated with NODAGA-tris(t-Bu ester) and subsequently radiolabeled with [⁶⁸Ga]Ga-chloride. The prepared [⁶⁸Ga]Ga-NODAGA-peptide 1 and [⁶⁸Ga]Ga-NODAGA-peptide 2 were tested for radiochemical purity and saline/plasma stability. Consequently, the binding affinity toward VEGFRs was assessed in vitro on human glioblastoma and kidney carcinoma cells. The found peptide receptor affinity was compared with the calculated values in the PROtein binDIng enerGY prediction (PRODIGY) server. Finally, the biodistribution study was performed on BALB/c female mice to reveal the basic pharmacokinetic behavior of radiopeptides.

RESULTS

The in vitro affinity testing of [⁶⁸Ga]Ga-NODAGA-peptides 1 and 2 showed retained receptor binding as characterized by equilibrium dissociation constant (K_D) values in the range of 0.5-1.2 μM and inhibitory concentration 50% (IC₅₀) values in the range of 3.0-5.6 μM. Better binding properties of peptide 2 to VEGFR-1/-2 were found in the PRODIGY server. The biodistribution study on mice showed remarkable accumulation of both peptides in the kidneys and urinary bladder with a short half-life after intravenous application. The in vitro plasma stability of [⁶⁸Ga]Ga-NODAGA-peptide 2 was superior to that of [⁶⁸Ga]Ga-NODAGA-peptide 1.

CONCLUSIONS

The obtained results demonstrated a high radiolabeling yield with no need for purification and preserved binding potency of ⁶⁸Ga-labeled peptides 1 and 2 toward VEGFRs in cancer cells. The peptide-receptor protein interaction assessed in protein-peptide docking determined the strongest interaction of peptide 2 with domain 2 of VEGFR-2 in addition to a more acceptable plasma stability (t_1/2 = 120 min) than that for peptide 1. We found both radiolabeled peptides very potent in their receptor binding, which makes them suitable imaging agents. The rapid transition of the radiopeptides into the urinary tract indicates suitable pharmacokinetic characteristics.