TRAIL-NP hybrids for cancer therapy: a review

Advancing Targeted Therapies in Pancreatic Cancer: Leveraging Molecular Aberrations for Therapeutic Success

Pancreatic cancer is one of the most deadly with poor prognosis and overall survival rate due to the dense stroma in the tumors which often is challenging for the delivery of drug to penetrate deep inside the tumor bed and usually results in the progression of cancer. The conventional treatment such as chemotherapy, radiotherapy or surgery shows a minimal benefit in the survival due to the drug resistance, poor penetration, less radiosensitivity or recurrence of tumor. There is an urgent demand to develop molecular- level targeted therapies to achieve therapeutic efficacy in the pancreatic ductal adenocarcinoma (PDAC) patients. The precision oncology focuses on the unique attributes of the patient such as epigenome, proteome, genome, microbiome, lifestyle and diet habits which contributes to promote oncogenesis. The targeted therapy helps to target the mutated proteins responsible for controlling growth, division and metastasis of tumor in the cancer cells. It is very important to consider all the attributes of the patient to provide the suitable personalized treatment to avoid any severe side effects. In this review, we have laid emphasis on the precision medicine; the utmost priority is to improve the survival of cancer patients by targeting molecular mutations through transmembrane proteins, inhibitors, signaling pathways, immunotherapy, gene therapy or the use of nanocarriers for the delivery at the tumor site. It will become beneficial therapeutic window to be considered for the advanced stage pancreatic cancer patients to prolong their survival rate.

Vimentin, inversely correlating with infiltration of CD8 + T lymphocytes, promotes nuclear translocation of PD-L1 in esophageal squamous cell carcinoma

Vimentin has been considered a canonical marker of epithelial-mesenchymal transition (EMT) and is associated with tumor escape characterized by aberrant PD-L1 expression. However, whether there is a relationship between vimentin and PD-L1 in esophageal squamous cell carcinoma (ESCC) remains poorly understood. The immunological involvement of vimentin in ESCC was first analyzed by multiplex immunofluorescence staining in ESCC tissue microarray followed by a xenografted mouse model. In vivo, C57BL/6 mice were subcutaneously transplanted with AKR cells after stable silencing of vimentin. In vivo results showed that in addition to PD-L1 and PD-L2 expression, vimentin expression was inversely correlated with CD8+ T-cell infiltration. Mechanistically, vimentin can directly interact with PD-L1 and promote nuclear translocation of PD-L1 in AKR cells. In addition, SEMA6C, STC-2 and TRAILR2 were identified as cytokines modulated by vimentin. Blockade of STC-2 and TRAILR2 in co-culture with their own primary antibodies was shown to recruit more CD8+ T cells than controls. Together, these data strongly suggest targeting Vimenin to overcome the immune cycle in ESCC.

Nanoparticle-mediated gene delivery of TRAIL to resistant cancer cells: A review

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), also known as APO2L, has emerged as a highly potential anticancer agent because of its capacity to effectively trigger apoptosis in tumor cells by specifically binding to either of its death receptors (DR4 or DR5) while having no adverse effects on normal cells. Nevertheless, its practical use has been hindered by its inefficient pharmacokinetics characteristics, the challenges involved in its administration and delivery to targeted cells, and the resistance exhibited by most cancer cells towards TRAIL. Gene therapy, as a promising approach would be able to potentially circumvent TRAIL-based cancer therapy challenges mainly through localized TRAIL expression and generating a bystander impact. Among different strategies, using nanoparticles in TRAIL gene delivery allows for precise targeting, and overcoming TRAIL resistance by combination therapy. In this review, we go over potential mechanisms by which cancer cells achieve resistance to TRAIL and provide an overview of different carriers for delivering of the TRAIL gene to resistant cancer cells, focusing on different types of nanoparticles utilized in this context. We will also explore the challenges, and investigate future perspectives of this nanomedicine approach for cancer therapy.

Combinational Gene Therapy toward Cancer with Nanoplatform: Strategies and Principles

Cancer remains a significant threat to human health. While numerous therapies have been developed to combat the disease, traditional treatments such as chemotherapy and radiotherapy are suboptimal and associated with significant side effects. Gene therapy is an emerging therapeutic approach that offers improved targeting and reduced side effects compared with traditional treatments. Using siRNA and other nucleic acid-based drugs in cancer treatment has generated significant interest among researchers. Nanocarriers, such as liposomes, can effectively deliver these agents to tumor sites. However, gene therapy alone is often insufficient to eradicate tumors, and there is a risk of recurrence. Therefore, combining gene therapy with other therapies using nanocarriers, such as phototherapy and magnetic hyperthermia therapy, can lead to synergistic therapeutic effects through different mechanisms. In this review, we summarize various ways in which gene therapy can be combined with other therapies and highlight the role of nanoplatforms in mediating these combined therapies, which would inspire novel design ideas toward combination therapies. Additionally, bottlenecks and barriers to gene therapy should be addressed in the near future to achieve better clinical efficacy.

Superior TRAIL gene expression and cancer cell apoptosis mediated by highly branched-linear poly(β-amino ester)s

Extensive efforts have been dedicated to enhancing the expression of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) in cancer cells for the development of effective cancer treatments. However, highly safe and efficient delivery of TRAIL gene remains a significant challenge, especially using cationic polymers. Here, a series of highly branched-linear poly(β-amino ester)s (H-LPAEs) are developed through a unique oligomer branching strategy. H-LPAEs exhibit a more uniform distribution of linear segments and branching units, leading to excellent DNA condensation and favorable physicochemical properties of H-LPAE/DNA polyplexes. In SW1353 and BMSC cells, the optimized H-LPAEs, H-LPAEB4-S5-TMPTA, achieves superior gene transfection efficiency of 58.0% and 33.4%, which were 2.5-fold and 2.0-fold higher than that of the leading commercial gene transfection reagent, Lipofectamine 3000. Excitingly, H-LPAEB4-S5-TMPTA mediated 56.7% and 28.1% cell apoptosis in HepG2 cells and HeLa cells highlighting its potential application in cancer gene therapy. In addition, locally administered H-LPAEB4-S5-TMPTA delivered TRAIL DNA to HepG2 xenograft tumors and inhibited tumor growth in vivo. This study not only proposes a novel strategy for synthesizing poly(β-amino ester)s with a unique branched-linear topology but also identifies a promising candidate for highly efficient TRAIL gene transfection.

Expression profiling of anticancer genes in colorectal cancer patients and their in vitro induction by riproximin, a ribosomal inactivating plant protein

BACKGROUND

Ectopic expression of anticancer genes (ACGs) imposes antineoplastic effects on transformed cells. Clinically, reduced expression of these genes has been linked with poor prognosis, metastasis and chemo/radiotherapy resistance in cancers. Identifying expression pattern of ACGs is crucial to establish their prognostic and therapeutic relevance in colorectal cancer (CRC). In addition to the clinical perspective, naturally occurring compounds can be explored in parallel for inducing ACGs to achieve cancer cell-specific death.

METHODOLOGY

Expression profiles of three ACGs (NOXA, PAR-4, TRAIL) were identified via real-time PCR in CRC clinical isolates. Time lapse-based expression modifications in ACGs were studied in a CRC liver metastasis animal model using microarray methodology. Effects of a purified plant protein (riproximin) on selected ACGs were identified in three primary and metastatic CRC cell lines by real-time PCR. Lastly, importance of the ACGs in a cellular environment was highlighted via bioinformatic analysis.

RESULTS

ACGs (except NOXA) were persistently downregulated in clinical isolates when comparing the overall mean expression values with normal mucosa levels. In vivo studies showed a prominent inhibition of NOXA and PAR-4 genes in implanted CRC cells during rat liver colonization. TRAIL showed deviation from this theme while showing marked induction during the early period of liver colonization (days 3 and 6 after CRC cell implantation). Riproximin exhibited substantial potential of inducing ACGs at transcriptome levels in selected CRC cell lines. Bioinformatic analysis showed that vital molecular/functional aspects of a cell are associated with the presence of ACGs.

CONCLUSION

ACGs are downregulated in primary and metastatic phase of CRC. Riproximin effectively induces ACGs in CRC cells and can be exploited for clinical investigations over time.

Evolving strategies and application of proteins and peptide therapeutics in cancer treatment

Several proteins and peptides have therapeutic potential and can be used for cancer therapy. By binding to cell surface receptors and other indicators uniquely linked with or overexpressed on tumors compared to healthy tissue, protein biologics enhance the active targeting of cancer cells, as opposed to the passive targeting of cells by conventional small-molecule chemotherapeutics. This study focuses on peptide medications that exist to slow or stop tumor growth and the spread of cancer, demonstrating the therapeutic potential of peptides in cancer treatment. As an alternative to standard chemotherapy, peptides that selectively kill cancer cells while sparing healthy tissue are developing. A mountain of clinical evidence supports the efficacy of peptide-based cancer vaccines. Since a single treatment technique may not be sufficient to produce favourable results in the fight against cancer, combination therapy is emerging as an effective option to generate synergistic benefits. One example of this new area is the use of anticancer peptides in combination with nonpeptidic cytotoxic drugs or the combination of immunotherapy with conventional therapies like radiation and chemotherapy. This review focuses on the different natural and synthetic peptides obtained and researched. Discoveries, manufacture, and modifications of peptide drugs, as well as their contemporary applications, are summarized in this review. We also discuss the benefits and difficulties of potential advances in therapeutic peptides.

Recent Advances in the Development of Nanodelivery Systems Targeting the TRAIL Death Receptor Pathway

The TRAIL (TNF-related apoptosis-inducing ligand) apoptotic pathway is extensively exploited in the development of targeted antitumor therapy due to TRAIL specificity towards its cognate receptors, namely death receptors DR4 and DR5. Although therapies targeting the TRAIL pathway have encountered many obstacles in attempts at clinical implementation for cancer treatment, the unique features of the TRAIL signaling pathway continue to attract the attention of researchers. Special attention is paid to the design of novel nanoscaled delivery systems, primarily aimed at increasing the valency of the ligand for improved death receptor clustering that enhances apoptotic signaling. Optionally, complex nanoformulations can allow the encapsulation of several therapeutic molecules for a combined synergistic effect, for example, chemotherapeutic agents or photosensitizers. Scaffolds for the developed nanodelivery systems are fabricated by a wide range of conventional clinically approved materials and innovative ones, including metals, carbon, lipids, polymers, nanogels, protein nanocages, virus-based nanoparticles, dendrimers, DNA origami nanostructures, and their complex combinations. Most nanotherapeutics targeting the TRAIL pathway are aimed at tumor therapy and theranostics. However, given the wide spectrum of action of TRAIL due to its natural role in immune system homeostasis, other therapeutic areas are also involved, such as liver fibrosis, rheumatoid arthritis, Alzheimer's disease, and inflammatory diseases caused by bacterial infections. This review summarizes the recent innovative developments in the design of nanodelivery systems modified with TRAIL pathway-targeting ligands.

TRAIL/S-layer/graphene quantum dot nanohybrid enhanced stability and anticancer activity of TRAIL on colon cancer cells

Tumor necrosis factor (TNF)-related apoptosis inducing ligand (TRAIL), known as a cytokine of the TNF superfamily, is considered a promising antitumor agent due to its ability to selectively induce apoptosis in a wide variety of cancer cells. However, failure of its successful translation into clinic has led to development of nano-based platforms aiming to improve TRAIL therapeutic efficacy. In this regard, we fabricated a novel TRAIL-S-layer fusion protein (S-TRAIL) conjugated with graphene quantum dots (GQDs) to benefit both the self-assembly of S-layer proteins, which leads to elevated TRAIL functional stability, and unique optical properties of GQDs. Noncovalent conjugation of biocompatible GQDs and soluble fusion protein was verified via UV–visible and fluorescence spectroscopy, size and ζ-potential measurements and transmission electron microscopy. The potential anticancer efficacy of the nanohybrid system on intrinsically resistant cells to TRAIL (HT-29 human colon carcinoma cells) was investigated by MTT assay and flow cytometry, which indicated about 80% apoptosis in cancer cells. These results highlight the potential of TRAIL as a therapeutic protein that can be extensively improved by taking advantage of nanotechnology and introduce S-TRAIL/GQD complex as a promising nanohybrid system in cancer treatment.

Intracranial delivery of synthetic mRNA to suppress glioblastoma

Owing to messenger RNA's unique biological advantages, it has received increasing attention to be used as a therapeutic, known as mRNA-based gene therapy. It is critical to have an ideal strategy of mRNA gene therapy for glioma, which grows in a special environment. In the present study, we screened out a safe and efficient transfection reagent for intracranial delivery of synthetic mRNA in mouse brain. First, in order to analyze the effect of different transfection reagents on the intracranial delivery of mRNA, the synthetic luciferase mRNA was wrapped with two different transfection reagents and microinjected into the brain at the fixed point. The expression status of delivered mRNA was monitored by a small animal imaging system. The possible reagent-induced biological toxicity was evaluated by behavioral and blood biochemical measurements. Then, to test the therapeutic effect of our intracranial delivery mRNA model on glioma, synthetic modified tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) mRNA was used as an example of therapeutic application. This model demonstrated that synthetic mRNA could be successfully delivered into the brain using commercially available transfection reagents, and TransIT-mRNA showed better results than in vivo-jetPEI kit. This model can be applied in precise targeting and personalized gene therapy of glioma.

Strain and crystallite size controlled ordering of Heusler nanoparticles having high heating rate for magneto-thermal application

Heusler compound nanoparticles with good structural ordering need to be investigated as a potential material class for magneto-thermal applications requiring heat generation in presence of an oscillating magnetic field. Here, we report an important finding of a structural parameter related to the product of the strain and the coherent crystallite size, that can be used to efficiently control the structural ordering and the magnetic property of the Heulser compound nanoparticles. The optimization of this product parameter is found to enhance both the structural ordering and magnetic transition temperature in Co₂FeSn Heusler nanoparticles. Furthermore, using magnetic hyperthermia measurements we demonstrate the possibility of heat generation using Heusler compound nanoparticles comparable to that of conventional magnetic nanoparticles. This shall lead to the development of Heulser compounds for similar applications.

Target Nanoparticles against Pancreatic Cancer: Fewer Side Effects in Therapy

Pancreatic cancer is the most common lethal tumor in America. This lethality is related to limited treatment options. Conventional treatments involve the non-specific use of chemotherapeutical agents such as 5-FU, capecitabine, gemcitabine, paclitaxel, cisplatin, oxaliplatin, or irinotecan, which produce several side effects. This review focuses on the use of targeted nanoparticles, such as metallic nanoparticles, polymeric nanoparticles, liposomes, micelles, and carbon nanotubes as an alternative to standard treatment for pancreatic cancer. The principal objective of nanoparticles is reduction of the side effects that conventional treatments produce, mostly because of their non-specificity. Several molecular markers of pancreatic cancer cells have been studied to target nanoparticles and improve current treatment. Therefore, properly functionalized nanoparticles with specific aptamers or antibodies can be used to recognize pancreatic cancer cells. Once cancer is recognized, these nanoparticles can attack the tumor by drug delivery, gene therapy, or hyperthermia.

Improving Targeted Delivery and Antitumor Efficacy with Engineered Tumor Necrosis Factor-Related Apoptosis Ligand-Affibody Fusion Protein

Tumor necrosis factor-related apoptosis ligand (TRAIL) is a promising protein candidate for selective apoptosis of a variety of cancer cells. However, the short half-life and a lack of targeted delivery are major obstacles for its application in cancer therapy. Here, we propose a simple strategy to solve the targeting problem by genetically fusing an anti-HER2 affibody to the C-terminus of the TRAIL. The fusion protein TRAIL-affibody was produced as a soluble form with high yield in recombinant Escherichia coli. In vitro studies proved that the affibody domain promoted the cellular uptake of the fusion protein in the HER2 overexpressed SKOV-3 cells and improved its apoptosis-inducing ability. In addition, the fusion protein exhibited higher accumulation at the tumor site and greater antitumor effect than those of TRAIL in vivo, indicating that the affibody promoted the tumor homing of the TRAIL and then improved the therapeutic efficacy. Importantly, repeated injection of high-dose TRAIL-affibody showed no obvious toxicity in mice. These results demonstrated that the engineered TRAIL-affibody is promising to be a highly tumor-specific and targeted cancer therapeutic agent.

Amphiphilic Poly(N-vinylpyrrolidone) Nanoparticles Conjugated with DR5-Specific Antitumor Cytokine DR5-B for Targeted Delivery to Cancer Cells

Nanoparticles based on the biocompatible amphiphilic poly(N-vinylpyrrolidone) (Amph-PVP) derivatives are promising for drug delivery. Amph-PVPs self-aggregate in aqueous solutions with the formation of micellar nanoscaled structures. Amph-PVP nanoparticles are able to immobilize therapeutic molecules under mild conditions. As is well known, many efforts have been made to exploit the DR5-dependent apoptosis induction for cancer treatment. The aim of the study was to fabricate Amph-PVP-based nanoparticles covalently conjugated with antitumor DR5-specific TRAIL (Tumor necrosis factor-related apoptosis-inducing ligand) variant DR5-B and to evaluate their in vitro cytotoxicity in 3D tumor spheroids. The Amph-PVP nanoparticles were obtained from a 1:1 mixture of unmodified and maleimide-modified polymeric chains, while DR5-B protein was modified by cysteine residue at the N-end for covalent conjugation with Amph-PVP. The nanoparticles were found to enhance cytotoxicity effects compared to those of free DR5-B in both 2D (monolayer culture) and 3D (tumor spheroids) in vitro models. The cytotoxicity of the nanoparticles was investigated in human cell lines, namely breast adenocarcinoma MCF-7 and colorectal carcinomas HCT116 and HT29. Notably, DR5-B conjugation with Amph-PVP nanoparticles sensitized resistant multicellular tumor spheroids from MCF-7 and HT29 cells. Taking into account the nanoparticles loading ability with a wide range of low-molecular-weight antitumor chemotherapeutics into hydrophobic core and feasibility of conjugation with hydrophilic therapeutic molecules by click chemistry, we suggest further development to obtain a versatile system for targeted drug delivery into tumor cells.

Stem cells for the treatment of glioblastoma: a 20-year perspective

Glioblastoma, the deadliest form of primary brain tumor, remains a disease without cure. Treatment resistance is in large part attributed to limitations in the delivery and distribution of therapeutic agents. Over the last 20 years, numerous preclinical studies have demonstrated the feasibility and efficacy of stem cells as antiglioma agents, leading to the development of trials to test these therapies in the clinic. In this review we present and analyze these studies, discuss mechanisms underlying their beneficial effect and highlight experimental progress, limitations and the emergence of promising new therapeutic avenues. We hope to increase awareness of the advantages brought by stem cells for the treatment of glioblastoma and inspire further studies that will lead to accelerated implementation of effective therapies.

Glioblastoma is the deadliest and most common form of brain tumor, for which there is no cure. It is very difficult to deliver medicine to the tumor cells, because they spread out widely into the normal brain, and local blood vessels represent a barrier that most medicines cannot cross. It was shown, in many studies over the last 20 years, that stem cells are attracted toward the tumor and that they can deliver many kinds of therapeutic agents directly to brain cancer cells and shrink the tumor. In this review we analyze these studies and present new discoveries that can be used to make stem cell therapies for glioblastoma more effective to prolong the life of patients with brain tumors.

Grafting TRAIL through Either Amino or Carboxylic Groups onto Maghemite Nanoparticles: Influence on Pro-Apoptotic Efficiency

Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is a member of the TNF cytokine superfamily. TRAIL is able to induce apoptosis through engagement of its death receptors DR4 and DR5 in a wide variety of tumor cells while sparing vital normal cells. This makes it a promising agent for cancer therapy. Here, we present two different ways of covalently grafting TRAIL onto maghemite nanoparticles (NPs): (a) by using carboxylic acid groups of the protein to graft it onto maghemite NPs previously functionalized with amino groups, and (b) by using the amino functions of the protein to graft it onto NPs functionalized with carboxylic acid groups. The two resulting nanovectors, NH-TRAIL@NPs-CO and CO-TRAIL@NPs-NH, were thoroughly characterized. Biological studies performed on human breast and lung carcinoma cells (MDA-MB-231 and H1703 cell lines) established these nanovectors are potential agents for cancer therapy. The pro-apoptotic effect is somewhat greater for CO-TRAIL@NPs-NH than NH-TRAIL@NPs-CO, as evidenced by viability studies and apoptosis analysis. A computational study indicated that regardless of whether TRAIL is attached to NPs through an acid or an amino group, DR4 recognition is not affected in either case.

FENDRR: A pivotal, cancer-related, long non-coding RNA

Long non-coding RNAs (lncRNAs) have more than 200 nucleotides and do not encode proteins. Based on numerous studies, lncRNAs have emerged as new and crucial regulators of biological function and have been implicated in the pathogenesis of a variety of diseases, especially cancers. Specific lncRNAs have been identified as novel molecular biomarkers for cancer diagnosis, prognosis, and treatment efficacy. Fetal-lethal non-coding developmental regulatory RNA (FENDRR, also known as FOXF1-AS1) is a novel lncRNA that is located at chr3q13.31 and has four exons and 3099 nucleotides, and its genomic site is located at chr3q13.31. FENDRR is abnormally expressed in a variety of cancers and is significantly associated with different clinical characteristics. In addition, FENDRR has shown potential as a biomarker for cancer diagnosis, prognosis, and treatment. In this review, we summarize the current understanding of FENDRR and its mechanistic role in cancer progression. We also discuss recent insights into the clinical significance of FENDRR for cancer diagnosis, prognosis, and treatment.

Engineering of Neutrophil Membrane Camouflaging Nanoparticles Realizes Targeted Drug Delivery for Amplified Antitumor Therapy

Purpose

Although the neutrophil membrane (NM)-based nanoparticulate delivery system has exhibited rapid advances in tumor targeting stemmed from the inherited instinct, the antitumor effect requires further improvement due to inefficient cellular internalization in the absence of specific interactions between NM-coated nanoparticles and tumor cells.

Methods

Herein, we fabricated drug-paclitaxel loaded NM camouflaging nanoparticles (TNM-PN) modified with tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), favorable for the cellular internalization.

Results

The results showed that TNM-PN exerted a significant cytotoxicity to tumor cells by TRAIL-mediated endocytosis and strong adhesion to inflamed endothelial cells in vitro. Due to TRAIL modification as well as the adhesive interactions between neutrophil and inflamed tumor vascular endothelial cells, tumors in TNM-PN group exhibited almost 2-fold higher fluorescence intensities than that of NM camouflaging nanoparticles and 3-fold higher than that of bare nanoparticles, respectively. Significant tumor inhibition and survival rates of mice were achieved in TNM-PN group as a consequence of prolonged blood circulations to 48 h and preferential tumor accumulations, which was ascribed to targeting adhesion originated from NM to immune evasion and subsequent excellent cellular internalization.

Conclusion

The research unveiled a novel strategy of amplifying cellular internalization based on NM coating nanotechnology to boost antitumor efficacy.

TRAIL promotes hepatocellular carcinoma apoptosis and inhibits proliferation and migration via interacting with IER3

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) can induce substantial cytotoxicity in tumor cells but rarely exert cytotoxic activity on non-transformed cells. In the present study, we therefore evaluated interactions between TRAIL and IER3 via co-immunoprecipitation and immunofluorescence analyses, leading us to determine that these two proteins were able to drive the apoptotic death of hepatocellular carcinoma (HCC) cells and to disrupt their proliferative and migratory abilities both in vitro and in vivo. From a mechanistic perspective, we determined that TRAIL and IER3 were capable of inhibiting Wnt/β-catenin signaling. Together, these results indicate that TRAIL can control the pathogenesis of HCC at least in part via interacting with IER3 to inhibit Wnt/β-catenin signaling, thus indicating that this TRAIL/IER3/β-catenin axis may be a viable therapeutic target in HCC patients.

Revisiting the role of TRAIL/TRAIL-R in cancer biology and therapy

TNF-related apoptosis-inducing ligand (TRAIL), a member of the TNF superfamily, can induce apoptosis in cancer cells, sparing normal cells when bound to its associated death receptors (DR4/DR5). This unique mechanism makes TRAIL a potential anticancer therapeutic agent. However, clinical trials of recombinant TRAIL protein and TRAIL receptor agonist monoclonal antibodies have shown disappointing results due to its short half-life, poor pharmacokinetics and the resistance of the cancer cells. This review summarizes TRAIL-induced apoptotic and survival pathways as well as mechanisms leading to apoptotic resistance. Recent development of methods to overcome cancer cell resistance to TRAIL-induced apoptosis, such as protein modification, combination therapy and TRAIL-based gene therapy, appear promising. We also discuss the challenges and opportunities in the development of TRAIL-based therapies for the treatment of human cancers.

Designed ferritin nanocages displaying trimeric TRAIL and tumor-targeting peptides confer superior anti-tumor efficacy

TRAIL is considered a promising target for cancer therapy because it mediates activation of the extrinsic apoptosis pathway in a tumor-specific manner by binding to and trimerizing its functional receptors, DR4 or DR5. Although recombinant human TRAIL has shown high potency and specificity for killing cancer cells in preclinical studies, it has failed in multiple clinical trials for several reasons, including a very short half-life mainly caused by instability of the monomeric form of TRAIL and rapid renal clearance of the off-targeted TRAIL. To overcome such obstacles, we developed a TRAIL-active trimer nanocage (TRAIL-ATNC) that presents the TRAIL ligand in its trimer-like conformation by connecting it to a triple helix sequence that links to the threefold axis of the ferritin nanocage. We also ligated the tumor-targeting peptide, IL4rP, to TRAIL-ATNC to enhance tumor targeting. The developed TRAIL-ATNCIL4rP showed enhanced agonistic activity compared with monomeric TRAIL. The in vivo serum half-life of TRAIL-ATNCIL4rP was ~ 16-times longer than that of native TRAIL. As a consequence of these properties, TRAIL-ATNCIL4rP exhibited efficacy as an anti-tumor agent in vivo against xenograft breast cancer as well as orthotopic pancreatic cancer models, highlighting the promise of this system for development as novel therapeutics against cancer.

Antitumor Activity of Cabazitaxel and MSC-TRAIL Derived Extracellular Vesicles in Drug-Resistant Oral Squamous Cell Carcinoma

INTRODUCTION

TRAIL (tumor necrosis factor-related apoptosis-inducing ligand) can induce apoptosis in a variety of cancer cells. However, drug resistance of tumor and short half-life seriously affects its clinical targeted therapy. Cabazitaxel (CTX) is a taxane drug, which can induce apoptosis or autophagy by inhibiting the phosphorylation of PI3K/Akt/mTOR and sensitive to some drug-resistant tumors. Therefore, we explored the possibility of developing a mesenchymal stem cell-derived exosomes (MSC-EXO) vector for oral squamous cell carcinoma (OSCC) to deliver CTX/TRAIL combinations.

METHODS

After ultracentrifugation and dialysis, CTX/TRAIL loaded exosomes transfected MSC (MSCT)-derived exosome (EXO) (MSCT-EXO/CTX) were isolated and purified. The expression of CD63, CD9 and TRAIL was detected by BCA to confirm the origin of EXO. High-performance liquid chromatography (HPLC) was used to determine the drug loading of VPF and draw the in vitro release profile. MTT assay, flow cytometry and Western blot were used to detect the antitumor effect of MSCT-EXO/CTX in vitro. Subsequently, the antitumor effect of MSCT-EXO/CTX in vivo was verified by mouse model.

RESULTS

The diameter of the membrane particles was about 60-150 nm. We have proved that the incorporation and release of CTX in MSCT-EXO can inhibit the activation of PI3K, Akt and mTOR, which is a possible synergistic mechanism of CTX. MSCT-EXO and CTX can induce the apoptosis of SCC25 tumor cells in a dose-dependent manner and exert a good synergistic effect in the proportion range of 10:1-5:1. The inherent activity of MSCT-EXO and the direct effect of MSCT-EXO/CTX on OSCC confirm that MSCT-EXO/CTX makes MSCT-EXO and CTX have an efficient synergistic effect and a highly effective pharmacological inhibition on cancer cells, as verified by the subsequent mouse model. MSCT-EXO/CTX showed the lowest relative tumor volume and the highest tumor inhibition rate (P<0.05) in vivo.

CONCLUSION

An MSCT-EXO-based CTX delivery system might be an effective anticancer method.

Identification and analysis of key lncRNAs in malignant-transformed BEAS-2B cells induced with coal tar pitch by microarray analysis

This study aims to explore the key and differentially expressed long non-coding RNAs (lncRNAs) and elucidates their possible mechanisms in malignant-transformed Human bronchial epithelial (BEAS-2B) cells induced by coal tar pitch extracts (CTPE). BEAS-2B cells were stimulated with 2.4 μg/ml CTPE, then passaged for three times which were named CTPE1 and then passaged until passage 30 (CTPE30). The results showed that cells of CTPE30 appeared abnormal morphology. Furthermore, migration, clonality and proliferation of cells in CTPE group were significantly increased compared with those in control groups. However, the apoptosis of cells in CTPE group was inhibited. A total of 569 differentially expressed mRNAs and 707 differentially expressed lncRNAs were screened out, among which four lncRNAs were validated and were consistent with the microarray results. 32 target genes were screened out by Co-expression network. The study suggests that differentially expressed lncRNAs may play a potential role in lung carcinogenesis.

TRAIL acts synergistically with iron oxide nanocluster-mediated magneto- and photothermia

Targeting TRAIL (Tumor necrosis factor (TNF)-Related Apoptosis-Inducing Ligand) receptors for cancer therapy remains challenging due to tumor cell resistance and poor preparations of TRAIL or its derivatives. Herein, to optimize its therapeutic use, TRAIL was grafted onto iron oxide nanoclusters (NCs) with the aim of increasing its pro-apoptotic potential through nanoparticle-mediated magnetic hyperthermia (MHT) or photothermia (PT). Methods: The nanovector, NC@TRAIL, was characterized in terms of size, grafting efficiency, and potential for MHT and PT. The therapeutic function was assessed on a TRAIL-resistant breast cancer cell line, MDA-MB-231, wild type (WT) or TRAIL-receptor-deficient (DKO), by combining complementary methylene blue assay and flow cytometry detection of apoptosis and necrosis. Results: Combined with MHT or PT under conditions of "moderate hyperthermia" at low concentrations, NC@TRAIL acts synergistically with the TRAIL receptor to increase the cell death rate beyond what can be explained by the mere global elevation of temperature. In contrast, all results are consistent with the idea that there are hotspots, close to the nanovector and, therefore, to the membrane receptor, which cause disruption of the cell membrane. Furthermore, nanovectors targeting other membrane receptors, unrelated to the TNF superfamily, were also found to cause tumor cell damage upon PT. Indeed, functionalization of NCs by transferrin (NC@Tf) or human serum albumin (NC@HSA) induces tumor cell killing when combined with PT, albeit less efficiently than NC@TRAIL. Conclusions: Given that magnetic nanoparticles can easily be functionalized with molecules or proteins recognizing membrane receptors, these results should pave the way to original remote-controlled antitumoral targeted thermal therapies.

Aptamer-integrated α-Gal liposomes as bispecific agents to trigger immune response for killing tumor cells

A novel bispecific α-Gal liposome was constructed by self-assembling AS1411 aptamers into the α-Gal containing liposomes. The α-Gal liposomes were prepared using cell membranes of red blood cells from rabbit, which are composed of cholesterol, phospholipids, and α-Gal glycolipids. AS1411 is a DNA aptamer with high specificity and affinity for nucleolin and could integrate into liposomes by the modification of cholesterol. The bispecific α-Gal liposomes surface-functionalized by α-Gal and AS1411 aptamer could recognize anti-Gal antibodies and nucleolin overexpressed by tumor cells simultaneously, followed by activating the immune system to attack the tumor cells, resulting in the lysis of the tumor cells by antibody dependent cell-mediated cytotoxicity. Under simulated tumor environment, the lysis rate of MCF-7 cells treated by the AS1411 modified α-Gal liposomes drastically increased compared to the liposomes without AS1411 aptamer. This study suggests that the AS1411 modified α-Gal liposomes can recognize nucleolin-overexpressing tumor cells selectively, subsequently improve the effect of the immunotherapy with high specificity. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 1176-1183, 2019.

Presentation and Delivery of Tumor Necrosis Factor-Related Apoptosis-Inducing Ligand via Elongated Plant Viral Nanoparticle Enhances Antitumor Efficacy

Potato virus X (PVX) is a flexuous plant virus-based nanotechnology with promise in cancer therapy. As a high aspect ratio biologic (13 × 515 nm), PVX has excellent spatial control in structures and functions, offering high-precision nanoengineering for multivalent display of functional moieties. Herein, we demonstrate the preparation of the PVX-based nanocarrier for delivery of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), a promising protein drug that induces apoptosis in cancer cells but not healthy cells. TRAIL bound to PVX by coordination bonds between nickel-coordinated nitrilotriacetic acid on PVX and His-tag on the protein could mimic the bioactive "membrane-bound" state in native TRAIL, resulting in an elongated nanoparticle displaying up 490 therapeutic protein molecules. Our data show that PVX-delivered TRAIL activates caspase-mediated apoptosis more efficiently compared to soluble TRAIL; also in vivo the therapeutic nanoparticle outperforms in delaying tumor growth in an athymic nude mouse model bearing human triple-negative breast cancer xenografts. This proof-of-concept work highlights the potential of filamentous plant virus nanotechnologies, particularly for targeting protein drug delivery for cancer therapy.

Modified PAMAM vehicles for effective TRAIL gene delivery to colon adenocarcinoma: in vitro and in vivo evaluation

TRAIL (tumour necrosis factor-related apoptosis-inducing ligand) gene therapy is considered as one of the promising approaches for cancer treatment. Polyamidoamine (PAMAM) is one of the most extensively applied polymeric vector in gene delivery. In the current study, PAMAM (G4 and G5) dendrimers were modified with alkyl-carboxylate chain, PEG and cholesteryl chloroformate in order to enhance transfection efficiency through overcoming extracellular and intracellular barriers while reducing PAMAM cytotoxicity. Gene delivery efficiency of synthetized vectors was evaluated by both GFP (green fluorescent protein) reporter gene and TRAIL plasmid in colon cancer cells, in vitro and in vivo. The obtained results demonstrated that PAMAM G4-alkyl-PEG (3%)-Chol (5%)-TRAIL complexes at C/P ratio 4 could significantly increase cell death (29.45%) in comparison with unmodified PAMAM vector (15.5%). Moreover, in vivo study in C26 tumor-bearing BALB/c mice suggested that the prepared non-toxic safe vector could inhibit the tumor growth. This study represented the potent vehicle based on cholesterol-grafted PAMAM dendrimers with alkyl-PEG modification for efficient gene delivery in vitro and in vivo.

Designed trimer-mimetic TNF superfamily ligands on self-assembling nanocages

Presentation of an endogenous bioactive ligand in its native form is a key factor in controlling and determining its bioactivity, stability, and therapeutic efficacy. In this study, we developed a novel strategy for presenting trimeric ligands on nanocages by designing, optimizing and testing based on the rational design, high-resolution structural analysis and agonistic activity assays in vitro and in vivo. We successfully designed a nanocage that presents the TNF superfamily member, TRAIL (TNF-related apoptosis-inducing ligand) in its native-like trimeric structure. The native structure of TRAIL complexes was mimicked on the resulting trimeric TRAIL-presenting nanocages (TTPNs) by inserting sufficient spacing, determined from three-dimensional structural models, to provide optimal access to the corresponding receptors. The efficacy of TTPNs as an anti-tumor agent was confirmed in preclinical studies, which revealed up to 330-fold increased affinity, 62.5-fold enhanced apoptotic activity, and improved pharmacokinetic characteristics and stability compared with the monomeric form of TRAIL (mTRAIL). In this latter context, TTPNs exhibited greater than 90% stability over 1 mo, whereas ∼50% of mTRAIL aggregated within 2 d. Consistent with their enhanced stability and ultra-high affinity for the TRAIL receptor, TTPNs effectively induced apoptosis of tumor cells in vivo, leading to effective inhibition of tumor growth. Although TRAIL was used here as a proof-of-concept, all members of the TNF superfamily share the TNF homology domain (THD) and have similar distances between ecto-domain C-termini. Thus, other TNF superfamily ligands could be genetically substituted for the TRAIL ligand on the surface of this biomimetic delivery platform.

NanoTRAIL-Oncology: A Strategic Approach in Cancer Research and Therapy

TRAIL is a member of the tumor necrosis factor superfamily that can largely trigger apoptosis in a wide variety of cancer cells, but not in normal cells. However, insufficient exposure to cancer tissues or cells and drug resistance has severely impeded the clinical application of TRAIL. Recently, nanobiotechnology has brought about a revolution in advanced drug delivery for enhanced anticancer therapy using TRAIL. With the help of materials science, immunology, genetic engineering, and protein engineering, substantial progress is made by expressing fusion proteins with TRAIL, engineering TRAIL on biological membranes, and loading TRAIL into functional nanocarriers or conjugating it onto their surfaces. Thus, the nanoparticle-based TRAIL (nanoTRAIL) opens up intriguing opportunities for efficient and safe bioapplications. In this review, the mechanisms of action and biological function of TRAIL, as well as the current status of TRAIL treatment, are comprehensively discussed. The application of functional nanotechnology combined with TRAIL in cancer therapy is also discussed.

Pro-apoptotic peptides-based cancer therapies: challenges and strategies to enhance therapeutic efficacy

Cancer is a leading cause of death worldwide. Despite many advances in the field of cancer therapy, an effective cure is yet to be found. As a more potent alternative for the conventional small molecule anti-cancer drugs, pro-apoptotic peptides have emerged as a new class of anticancer agents. By interaction with certain members in the apoptotic pathways, they could effectively kill tumor cells. However, there remain bottleneck challenges for clinical application of these pro-apoptotic peptides in cancer therapy. In this review, we will overview the developed pro-apoptotic peptides and outline the widely adopted molecular-based and nanoparticle-based strategies to enhance their anti-tumor effects.

Effects of Recombinant Circularly Permuted Tumor Necrosis Factor (TNF)-Related Apoptosis-Inducing Ligand (TRAIL) (Recombinant Mutant Human TRAIL) in Combination with 5-Fluorouracil in Human Colorectal Cancer Cell Lines HCT116 and SW480

Background

Circularly permuted tumor necrosis factor-related apoptosis-inducing ligand, a mutant form of tumor necrosis factor-related apoptosis-inducing ligand, is an effective antitumor cytokine. However, its antitumor effect in colorectal cancer is unclear. This study assessed the antitumor effect of circularly permuted tumor necrosis factor-related apoptosis-inducing ligand alone or with 5-fluorouracil in colorectal cancer cells in vitro and explored the underlying mechanisms.

Material/Methods

We used the (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) (MTS) assay to analyze cell proliferation inhibition. The apoptotic effects of circularly permuted tumor necrosis factor-related apoptosis-inducing ligand, 5-fluorouracil, or both in human colorectal cancer cells were evaluated using flow cytometry. Furthermore, the levels of apoptosis-related proteins were examined by Western blotting.

Results

Compared to either agent alone, cotreatment with 5-fluorouracil and circularly permuted tumor necrosis factor-related apoptosis-inducing ligand showed obvious antitumor effects and induced significant apoptosis of colorectal cancer cells. 5-Fluorouracil enhanced circularly permuted tumor necrosis factor-related apoptosis-inducing ligand-induced apoptosis by increasing death receptor 4 and 5 levels in HCT116 cells, but only of death receptor 4 in SW480 cells. Moreover, 5-fluorouracil plus circularly permuted tumor necrosis factor-related apoptosis-inducing ligand increased apoptosis-related protein levels such as cleaved caspase-3, caspase-8, and poly-ADP-ribose polymerase and downregulated that of the survival protein B-cell lymphoma-extra-large. Pretreatment with the pan-caspase inhibitor, z-VAD-FMK, attenuated the caspase-dependent apoptosis induced by circularly permuted tumor necrosis factor-related apoptosis-inducing ligand alone or combined with 5-fluorouracil.

Conclusions

Cotreatment with 5-fluorouracil and circularly permuted tumor necrosis factor-related apoptosis-inducing ligand showed enhanced antitumor effects on colorectal cancer cells.

Antibodies and Derivatives Targeting DR4 and DR5 for Cancer Therapy

Developing therapeutics that induce apoptosis in cancer cells has become an increasingly attractive approach for the past 30 years. The discovery of tumor necrosis factor (TNF) superfamily members and more specifically TNF-related apoptosis-inducing ligand (TRAIL), the only cytokine of the family capable of eradicating selectively cancer cells, led to the development of numerous TRAIL derivatives targeting death receptor 4 (DR4) and death receptor 5 (DR5) for cancer therapy. With a few exceptions, preliminary attempts to use recombinant TRAIL, agonistic antibodies, or derivatives to target TRAIL agonist receptors in the clinic have been fairly disappointing. Nonetheless, a tremendous effort, worldwide, is being put into the development of novel strategic options to target TRAIL receptors. Antibodies and derivatives allow for the design of novel and efficient agonists. We summarize and discuss here the advantages and drawbacks of the soar of TRAIL therapeutics, from the first developments to the next generation of agonistic products, with a particular insight on new concepts.

Nanocarriers for TRAIL delivery: driving TRAIL back on track for cancer therapy

Since its initial identification, tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) has been shown to be capable of selectively inducing apoptosis in cancer cells. However, translation of the encouraging preclinical studies of this cytokine into the clinic has been restricted by its extremely short half-life, the presence of resistant cancer cell populations, and its inefficient in vivo delivery. Recently, there has been exceptional progress in developing novel formulations to increase the circulatory half-life of TRAIL and new combinations to treat cancers that are resistant to TRAIL. In particular, TRAIL-based nanotherapies offer the potential to improve the stability of TRAIL and prolong its half-life in plasma, to specifically deliver TRAIL to a particular target site, and to overcome resistance to TRAIL. The aim of this review is to provide an overview of the state-of-the art drug delivery systems that are currently being tested or developed to improve the biological attributes of TRAIL-based therapies.