Nano-TRAIL: a promising path to cancer therapy

Interactions between radiotherapy resistance mechanisms and the tumor microenvironment

BACKGROUND

Resistance to radiotherapy (RT) presents a significant clinical challenge in management of cancer. Recent evidence points to specific mechanisms of resistance within the tumor microenvironment (TME), which we aim to discuss, with the aim of overcoming the clinical challenge.

METHODS

We performed the narrative review using PubMed and Web of Science databases to identify studies that reported the regulative network and treatments of RT resistance from TME perspectives.

RESULTS

RT significantly changes the immune TME of cancers, which is closely appearing to play a key role in RT resistance (RTR) by modulating immune cell infiltration and function. Various phenotypes are involved in the development of RTR, such as autophagy, senescence, oxidative stress, cell polarization, ceramide metabolism, and angiogenesis in the TME. Key genes and pathways are also implicated in RTR, including immune and inflammatory cytokines, TGF-β, P53, the NF-κB pathway, the cGAS/STING pathway, the ERK and AKT pathway, and the STAT pathway. Based on the mechanism of RTR in the TME, many proposed routes to overcome RTR, several specifically target the TME including targeting fibroblast activation protein, exosomes management, nanomedicine, and immunotherapy. Many challenges in RT resistance still need to be further explored with emerging investigative methods, such as artificial intelligence, genetic technologies, and bioengineering.

CONCLUSIONS

The complex interactions between RT and TME significantly affect the efficiency of RT. Novel approaches to overcome this clinical difficulty are promising, which needs future work to further explore and identify better treatment strategies.

Combination therapies and novel delivery systems: a new frontier in overcoming TRAIL resistance in gastric cancer

Gastric cancer (GC) presents a formidable challenge in oncology, mainly due to its inherent resistance to therapies such as tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). This review delineates the multifaceted mechanisms underlying TRAIL resistance in GC, encompassing the deregulation of death receptors (DRs) and decoy receptors (DcRs), aberrant signaling pathways, and the influence of the tumor microenvironment (TME). Innovative strategies such as nanoparticle-based drug delivery systems and oncolytic viral therapies are being explored to counteract these challenges. Nanoparticles enhance TRAIL delivery and efficacy by exploiting the enhanced permeability and retention (EPR) effect, while oncolytic viruses can selectively target cancer cells and stimulate immune responses. Combination therapies, integrating TRAIL with conventional chemotherapeutics like paclitaxel, cisplatin, and 5-fluorouracil, have shown promise in overcoming resistance by modulating apoptotic pathways and downregulating multidrug resistance genes. Additionally, novel agents like cyclopamine, decitabine, and genistein have emerged as effective TRAIL sensitizers by modulating apoptotic pathways and enhancing DR5 expression. Furthermore, the integration of epigenetic modifiers can restore TRAIL sensitivity by demethylating DR4 and DR5 genes. This review emphasizes the need for a comprehensive understanding of the molecular underpinnings of TRAIL resistance and the potential of combination therapies and TRAIL delivery by nanoparticles and oncolytic viruses to enhance treatment outcomes in GC. Future research should focus on elucidating predictive biomarkers and optimizing therapeutic regimens to improve the clinical efficacy of TRAIL-based strategies in GC.

Discovery of potent quinone oxidoreductase 2 inhibitors to overcome TRAIL resistance of non-small cell lung cancer

Resistance to tumor-necrosis-factor-related apoptosis-inducing ligand (TRAIL) of cancer cells is a main obstacle for the chemotherapy. NRH: quinone oxidoreductase 2 (NQO2), known as a chemopreventive target, has emerged as a promising therapeutic target for overcoming TRAIL resistance in non-small cell lung cancer (NSCLC). Here we report the design, synthesis and evaluation of resveratrol analogues as novel selective NQO2 inhibitors, and analogue 20b, with potent NQO2 inhibitory activity (IC50 = 95 nM) and relatively low cytotoxicity, displayed synergistic lethal effects in combination with TRAIL on TRAIL-resistant NSCLC cells. In addition, mechanistic studies revealed that 20b sensitized TRAIL-resistant A549 cells to apoptosis through the generation of reactive oxygen species (ROS) and the upregulation of death receptor 5 (DR5). Furthermore, 20b showed no acute toxicity in the healthy mice at a single dose of 2000 mg/kg. Molecular docking confirmed the binding mode of 20b within the NQO2 active site, highlighting key interactions responsible for its enhanced potency. This study provided novel molecular templates for development of NQO2 inhibitor, and laid a foundation for developing agents against TRAIL-resistant cancers for targeting NQO2.

c-FLIP/Ku70 complex; A potential molecular target for apoptosis induction in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most lethal malignancies worldwide and the most common form of liver cancer. Despite global efforts toward early diagnosis and effective treatments, HCC is often diagnosed at advanced stages, where conventional therapies frequently lead to resistance and/or high recurrence rates. Therefore, novel biomarkers and promising medications are urgently required. Epi-drugs, or epigenetic-based medicines, have recently emerged as a promising therapeutic modality. Since the epigenome of the cancer cells is always dysregulated and this is followed by apoptosis-resistance, reprogramming the epigenome of cancer cells by epi-drugs (such as HDAC inhibitors (HDACis), and DNMT inhibitors (DNMTis)) could be an alternative approach to use in concert with established treatment protocols. C-FLIP, an anti-apoptotic protein, and Ku70, a member of the DNA repair system, bind together and make a cytoplasmic complex in certain cancers and induce resistance to apoptosis. Many epi-drugs, such as HDACis, can dissociate this complex through Ku70 acetylation and activate cellular apoptosis. The novel compounds for dissociating this complex could provide an innovative insight into molecular targeted HCC treatments. In this review, we address the innovative therapeutic potential of targeting c-FLIP/Ku70 complex by epi-drugs, particularly HDACis, to overcome apoptosis resistance of HCC cells. This review will cover the mechanisms by which the c-FLIP/Ku70 complex facilitates cancer cell survival, the impact of epigenetic alterations on the complex dissociation, and highlight HDACis potential in combination therapies, biomarker developments and mechanistic overviews. This review highlights c-FLIP ubiquitination and Ku70 acetylation levels as diagnostic and prognostic tools in HCC management.

Turn TRAIL Into Better Anticancer Therapeutic Through TRAIL Fusion Proteins

BACKGROUND

TNF-related apoptosis-inducing ligand (TRAIL) belongs to the tumor necrosis factor superfamily. TRAIL selectively induces apoptosis in tumor cells while sparing normal cells, which makes it an attractive candidate for cancer therapy. Recombinant soluble TRAIL and agonistic antibodies against TRAIL receptors have demonstrated safety and tolerability in clinical trials. However, they have failed to exhibit expected clinical efficacy. Consequently, extensive research has focused on optimizing TRAIL-based therapies, with one of the most common approaches being the construction of TRAIL fusion proteins.

METHODS

An extensive literature search was conducted to identify studies published over the past three decades related to TRAIL fusion proteins. These various TRAIL fusion strategies were categorized based on their effects achieved.

RESULTS

The main fusion strategies for TRAIL include: 1. Construction of stable TRAIL trimers; 2. Enhancing the polymerization capacity of soluble TRAIL; 3. Increasing the accumulation of TRAIL at tumor sites by fusing with antibody fragments or peptides; 4. Decorating immune cells with TRAIL; 5. Prolonging the half-life of TRAIL in vivo; 6. Sensitizing cancer cells to overcome resistance to TRAIL treatment.

CONCLUSION

This work focuses on the progress in recombinant TRAIL fusion proteins and aims to provide more rational and effective fusion strategies to enhance the efficacy of recombinant soluble TRAIL, facilitating its translation from bench to bedside as an effective anti-cancer therapeutic.

Targeting Death Receptor 5 (DR5) for the imaging and treatment of primary bone and soft tissue tumors: an update of the literature

Background

Death Receptor 5 (DR5) is expressed on the surface of primary bone and soft tissue sarcoma cells, and its activation induces cell death primarily through apoptosis. The combination of DR5 agonists and commonly used chemotherapeutic agents, such as doxorubicin, can promote cell death. Currently, clinical trials are investigating the effectiveness of DR5 activation using new biological agents, such as bi-specific or tetravalent antibodies, in improving the survival of patients with relapsed or refractory cancers. Furthermore, investigations continue into the use of novel combination therapies to enhance DR5 response, for example, with inhibitor of apoptosis protein (IAP) antagonist agents [such as the second mitochondria-derived activator of caspase (SMAC) mimetics] and with immune checkpoint inhibitor anti-programmed death-ligand 1 (anti-PD-L1) or anti-programmed cell death-1 (anti-PD-1) antibodies. Other therapies include nanoparticle-mediated delivery of TRAIL plasmid DNA or TRAIL mRNA and stem cells as a vehicle for the targeted delivery of anti-cancer agents, such as TRAIL, to the tumor.

Methods

Scoping review of the literature from November 2017 to March 2024, utilizing PubMed and Google Scholar.

Results

New agents under investigation include nanoTRAIL, anti-Kv10.1, multimeric IgM, and humanized tetravalent antibodies. Developments have been made to test novel agents, and imaging has been used to detect DR5 in preclinical models and patients. The models include 3D spheroids, genetically modified mouse models, a novel jaw osteosarcoma model, and patient-derived xenograft (PDX) animal models. There are currently two ongoing clinical trials focusing on the activation of DR5, namely, IGM-8444 and INBRX-109, which have progressed to phase 2. Further modifications of TRAIL delivery with fusion to single-chain variable fragments (scFv-TRAIL), directed against tumor-associated antigens (TAAs), and in the use of stem cells focus on targeted TRAIL delivery to cancer cells using bi-functional strategies.

Conclusion

In vitro, in vivo, and clinical trials, as well as advances in imaging and theranostics, indicate that targeting DR5 remains a valid strategy in the treatment of some relapsed and refractory cancers.

Cell death pathways: molecular mechanisms and therapeutic targets for cancer

Cell death regulation is essential for tissue homeostasis and its dysregulation often underlies cancer development. Understanding the different pathways of cell death can provide novel therapeutic strategies for battling cancer. This review explores several key cell death mechanisms of apoptosis, necroptosis, autophagic cell death, ferroptosis, and pyroptosis. The research gap addressed involves a thorough analysis of how these cell death pathways can be precisely targeted for cancer therapy, considering tumor heterogeneity and adaptation. It delves into genetic and epigenetic factors and signaling cascades like the phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) and mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) pathways, which are critical for the regulation of cell death. Additionally, the interaction of the microenvironment with tumor cells, and particularly the influence of hypoxia, nutrient deprivation, and immune cellular interactions, are explored. Emphasizing therapeutic strategies, this review highlights emerging modulators and inducers such as B cell lymphoma 2 (BCL2) homology domain 3 (BH3) mimetics, tumour necrosis factor-related apoptosis-inducing ligand (TRAIL), chloroquine, and innovative approaches to induce ferroptosis and pyroptosis. This review provides insights into cancer therapy's future direction, focusing on multifaceted approaches to influence cell death pathways and circumvent drug resistance. This examination of evolving strategies underlines the considerable clinical potential and the continuous necessity for in-depth exploration within this scientific domain.

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.

Circular RNA in cervical cancer: Fundamental mechanism and clinical potential

CC (CC) remains a significant global health concern, imposing a substantial health burden on women worldwide due to its high incidence and mortality rates. To address this issue, there is a need for ongoing research to uncover the underlying molecular mechanisms of CC and to discover novel diagnostic and therapeutic strategies. Recent progress in non-coding RNAs (ncRNAs) has opened new avenues for investigation, and circular RNAs (circRNAs) have emerged as molecules with diverse roles in various cellular processes. These circRNAs are distinct in structure, forming a closed loop, setting them apart from their linear counterparts. They are intricately involved in regulating different aspects of cellular functions, particularly in cell growth and development. Remarkably, circRNAs can have varying functions, either promoting or inhibiting oncogenic processes, depending on the specific cellular context. Recent studies have identified abnormal circRNAs expression patterns associated with CC, indicating their significant involvement in disease development. The differing circRNAs profiles linked to CC present promising opportunities for early detection, precise prognosis evaluation, and personalized treatment strategies. In this comprehensive review, we embark on a detailed exploration of CC-related circRNAs, elucidating their distinct roles and providing insights into the intricate molecular mechanisms governing CC's onset and progression. A growing body of evidence strongly suggests that circRNAs can serve as valuable biomarkers for early CC detection and hold potential as therapeutic targets for intervention. By delving into the complex interplay between circRNAs and CC, we are paving the way for innovative, individualized approaches to combat this serious disease, with the goal of reducing its impact on women's health globally and improving patient outcomes. As our understanding of circRNAs in the context of CC continues to deepen, the outlook for breakthroughs in diagnosis and treatment becomes increasingly promising.

Melatonin modulates tumor metabolism and mitigates metastasis

INTRODUCTION

Melatonin, originally isolated from the mammalian pineal gland, was subsequently identified in many animal cell types and in plants. While melatonin was discovered to inhibit cancer more than 5 decades ago, its anti-cancer potential has not been fully exploited despite its lack of serious toxicity over a very wide dose range, high safety margin, and its efficacy.

AREAS COVERED

This review elucidates the potential mechanisms by which melatonin interferes with tumor growth and metastasis, including its ability to alter tumor cell metabolism, inhibit epithelial-mesenchymal transition, reverse cancer chemoresistance, function synergistically with conventional cancer-inhibiting drugs while limiting many of their side effects. In contrast to its function as a potent antioxidant in normal cells, it may induce oxidative stress in cancer cells, contributing to its oncostatic actions.

EXPERT OPINION

Considering the large amount of experimental data supporting melatonin's multiple and varied inhibitory effects on numerous cancer types, coupled with the virtual lack of toxicity of this molecule, it has not been thoroughly tested as an anti-cancer agent in clinical trials. There seems to be significant resistance to such investigations, possibly because melatonin is inexpensive and non-patentable, and as a result there would be limited financial gain for its use.

Mitochondria in Cancer Stem Cells: From an Innocent Bystander to a Central Player in Therapy Resistance

Cancer continues to rank among the world's leading causes of mortality despite advancements in treatment. Cancer stem cells, which can self-renew, are present in low abundance and contribute significantly to tumor recurrence, tumorigenicity, and drug resistance to various therapies. The drug resistance observed in cancer stem cells is attributed to several factors, such as cellular quiescence, dormancy, elevated aldehyde dehydrogenase activity, apoptosis evasion mechanisms, high expression of drug efflux pumps, protective vascular niche, enhanced DNA damage response, scavenging of reactive oxygen species, hypoxic stability, and stemness-related signaling pathways. Multiple studies have shown that mitochondria play a pivotal role in conferring drug resistance to cancer stem cells, through mitochondrial biogenesis, metabolism, and dynamics. A better understanding of how mitochondria contribute to tumorigenesis, heterogeneity, and drug resistance could lead to the development of innovative cancer treatments.