Nanoparticles as Tools to Target Redox Homeostasis in Cancer Cells

New insights into targeted therapy of glioblastoma using smart nanoparticles

In recent times, the intersection of nanotechnology and biomedical research has given rise to nanobiomedicine, a captivating realm that holds immense promise for revolutionizing diagnostic and therapeutic approaches in the field of cancer. This innovative fusion of biology, medicine, and nanotechnology aims to create diagnostic and therapeutic agents with enhanced safety and efficacy, particularly in the realm of theranostics for various malignancies. Diverse inorganic, organic, and hybrid organic-inorganic nanoparticles, each possessing unique properties, have been introduced into this domain. This review seeks to highlight the latest strides in targeted glioblastoma therapy by focusing on the application of inorganic smart nanoparticles. Beyond exploring the general role of nanotechnology in medical applications, this review delves into groundbreaking strategies for glioblastoma treatment, showcasing the potential of smart nanoparticles through in vitro studies, in vivo investigations, and ongoing clinical trials.

Nanomaterials-Induced Redox Imbalance: Challenged and Opportunities for Nanomaterials in Cancer Therapy

Cancer cells typically display redox imbalance compared with normal cells due to increased metabolic rate, accumulated mitochondrial dysfunction, elevated cell signaling, and accelerated peroxisomal activities. This redox imbalance may regulate gene expression, alter protein stability, and modulate existing cellular programs, resulting in inefficient treatment modalities. Therapeutic strategies targeting intra- or extracellular redox states of cancer cells at varying state of progression may trigger programmed cell death if exceeded a certain threshold, enabling therapeutic selectivity and overcoming cancer resistance to radiotherapy and chemotherapy. Nanotechnology provides new opportunities for modulating redox state in cancer cells due to their excellent designability and high reactivity. Various nanomaterials are widely researched to enhance highly reactive substances (free radicals) production, disrupt the endogenous antioxidant defense systems, or both. Here, the physiological features of redox imbalance in cancer cells are described and the challenges in modulating redox state in cancer cells are illustrated. Then, nanomaterials that regulate redox imbalance are classified and elaborated upon based on their ability to target redox regulations. Finally, the future perspectives in this field are proposed. It is hoped this review provides guidance for the design of nanomaterials-based approaches involving modulating intra- or extracellular redox states for cancer therapy, especially for cancers resistant to radiotherapy or chemotherapy, etc.

Toxicity of superparamagnetic iron oxide nanoparticles on retinoblastoma mitochondria

PURPOSE

Retinoblastoma (RB) is one of the most important cancers in children with a higher rate of prevalence in developing countries. Despite different approaches to the treatment of RB, it seems necessary to discover a new approach to its treatment. Today, mitochondria are recognised as an important target in the treatment of cancer. Superparamagnetic iron oxide nanoparticles (SPIONs) have been studied by researchers due to their important biological effects.

METHODS

In this study, the effects of SPIONs on mitochondria isolated from Y79 retinoblastoma cells were investigated.

RESULTS

The results showed that SPIONs were able to increase the reactive oxygen species (ROS) level and subsequently damage the mitochondrial membrane and release cytochrome c a as one of the important pro-apoptotic proteins of RB mitochondria. Furthermore, the results indicated a decrease in cell viability and an increase in caspase-3 activity in Y79 retinoblastoma cells.

CONCLUSIONS

These events can lead to the killing of cancerous mitochondria. Our results suggest that SPIONs can cause mitochondrial dysfunction and death in RB mitochondria.

Mitochondrial targeting derivatives of honokiol enhanced selective antitumor activity in NCI-H446 cells and decreased in vivo toxicity in Caenorhabditis elegans

Mitochondria, responsible for ATP production and apoptosis regulation, play a key role in cancer cells. Honokiol regulates apoptosis through the endogenous mitochondrial pathway but does not specifically target tumor cells. We designed 28 novel derivatives of honokiol using triple-function delocalized lipophilic cations such as berberine and F16 as mitochondrion-targeting carriers. While all derivatives exhibited enhanced cytotoxicity toward tumor cells compared to honokiol, the derivative 2E-3-F16 exhibited a substantial tumor cell selectivity between NCI-H446 cancer cells and HBE cells by one order of magnitude and enhanced the sensitivity of A549 cells to cisplatin. Mechanistically, it targeted mitochondria and induced apoptosis by preventing tumor cells from entering the G0/G1 phases as well as inducing an abnormal elevation of reactive oxygen species, thereby decreasing the mitochondrial membrane potential level. It also showed lower toxicity toward Caenorhabditis elegans than honokiol. This study provides a possible method for developing mitochondrion-targeting antitumor drugs with high efficiency and low toxicity based on natural products.

Overcoming challenges in cancer treatment: Nano-enabled photodynamic therapy as a viable solution

Cancer presents a formidable challenge, necessitating innovative therapies that maximize effectiveness while minimizing harm to healthy tissues. Nanotechnology has emerged as a transformative force in cancer treatment, particularly through nano-enabled photodynamic therapy (NE-PDT), which leverages precise and targeted interventions. NE-PDT capitalizes on photosensitizers activated by light to generate reactive oxygen species (ROS) that initiate apoptotic pathways in cancer cells. Nanoparticle enhancements optimize this process, improving drug delivery, selectivity, and ROS production within tumors. This review dissects NE-PDT's mechanistic framework, showcasing its potential to harness apoptosis as a potent tool in cancer therapy. Furthermore, the review explores the synergy between NE-PDT and complementary treatments like chemotherapy, immunotherapy, and targeted therapies, highlighting the potential to amplify apoptotic responses, enhance immune recognition of cancer cells, and inhibit resistance mechanisms. Preclinical and clinical advancements in NE-PDT demonstrate its efficacy across various cancer types. Challenges in translating NE-PDT into clinical practice are also addressed, emphasizing the need for optimizing nanoparticle design, refining dosimetry, and ensuring long-term safety. Ultimately, NE-PDT represents a promising approach in cancer therapy, utilizing the intricate mechanisms of apoptosis to address therapeutic hurdles. The review underscores the importance of understanding the interplay between nanoparticles, ROS generation, and apoptotic pathways, contributing to a deeper comprehension of cancer biology and novel therapeutic strategies. As interdisciplinary collaborations continue to thrive, NE-PDT offers hope for effective and targeted cancer interventions, where apoptosis manipulation becomes central to conquering cancer. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

MgO Nanoparticles Obtained from an Innovative and Sustainable Route and Their Applications in Cancer Therapy

This paper aimed to evaluate the biological damages towards diseased cells caused by the use of MgO nanoparticles (NPs). The NPs are produced by a calcination process of a precursor, which is an aqueous suspension of nanostructured Mg(OH)2, in turn synthesized following our original, time-energy saving and scalable method able to guarantee short times, high yield of production (up to almost 10 kg/week of NPs), low environmental impact and low energy demand. The MgO NPs, in the form of dry powders, are organized as a network of intercrystallite channels, in turn constituted by monodispersed and roughly spherical NPs < 10 nm, preserving the original pseudo hexagonal-platelet morphology of the precursor. The produced MgO powders are diluted in a PBS solution to obtain different MgO suspension concentrations that are subsequently put in contact, for 3 days, with melanoma and healthy cells. The viable count, made at 24, 48 and 72 h from the beginning of the test, reveals a good cytotoxic activity of the NPs, already at low MgO concentrations. This is particularly marked after 72 h, showing a clear reduction in cellular proliferation in a MgO-concentration-dependent manner. Finally, the results obtained on human skin fibroblasts revealed that the use MgO NPs did not alter at all both the vitality and proliferation of healthy cells.

Study the Anticancer Properties of Thymol-Loaded PEGylated Bovine Serum Albumin Nanoparticles Conjugated with Folic Acid

Phenolic compounds such as Thymol have an effective role in suppressing cancer, however, their low solubility in aqueous solution has limited their use. This study aimed to prepare Thymol (TY)-loaded bovine serum albumin (BSA) nanoparticles surface-modified with polyethylene glycol (PEG) conjugated with folic acid (FA) and evaluate their inhibitory activity on cancer cells. The TY-BSA-PEG-FA was characterized using DLS, FESEM, and FTIR. The encapsulation efficiency (EE) was evaluated indirectly by using UV absorption. The antioxidant property of nanoparticles was evaluated by 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and ferric reducing ability of plasm (FRAP) methods. The effects of nanoparticles against cancer cells were investigated by MTT, AO/PI, flow cytometry, and real-time qPCR methods. The results showed the spherical morphology of TY-BSA-PEG-FA with an average size of 70.0 nm, a PDI of 0.32, a zeta potential of -11.3 mV, and an EE of 89.0±2.3 %. The cytotoxicity effects of nanoparticles against all cell lines were in a concentration-dependent manner. AGS gastric cancer cells were reported to be the most vulnerable to treatment, while pancreatic cancer cells (PANC-1) and normal skin cells (HFF) would be the most resistant. The SubG1 phase arrest of about 66 % occurred at 85 μg/mL. An increase in apoptotic cells in fluorescent staining, along with decreased expression of Bcl-2 and increased expression of the BAX gene demonstrated the induction of apoptosis in treated cells. The powerful inhibitory effect of nanoparticles in inhibiting ABTS free radicals (IC50 =82 μg/mL) and DPPH free radicals (IC50 =844 μg/mL) and the ability to reduce iron ions indicated the antioxidant effects of TY-BSA-PEG-FA. Based on these results, the synthesized nanoparticles may be suitable for further investigation in the treatment of cancer, notably gastric cancer.

Proanthocyanidins: A novel approach to Henoch‑Schonlein purpura through balancing immunity and arresting oxidative stress via TLR4/MyD88/NF‑κB signaling pathway (Review)

Henoch-Schonlein purpura (HSP), a recurrent and immunoglobulin (Ig)A-mediated vasculitis, presents not only as skin lesions but also as systemic involvement that can be life-threatening. Although the etiology of HSP remains unknown, immune imbalance and oxidative stress (OS) are primary contributors to its pathogenesis, alongside the abnormal activation of Toll-like receptor (TLR)/myeloid differentiation primary response gene 88 (MyD88)/nuclear factor-κB (NF-κB) pathway. TLRs, especially TLR4, stimulate downstream signaling molecules such as NF-κB and proinflammatory cytokines, which are released when TLRs combine with the key adapter molecule MyD88. This leads to the activation of T helper (Th) cell 2/Th17 and overproduction of reactive oxygen species (ROS). The function of regulatory T (Treg) cells is suppressed in the process. Th17/Treg imbalance then produces various inflammatory cytokines to promote proliferation and differentiation of B cells and the secretion of antibodies. IgA is secreted, and it binds to vascular endothelial surface receptors where the complex induces injury of the vascular endothelial cells. Additionally, excessive ROS creates OS that leads to an inflammatory response and vascular cell apoptosis or necrosis, thereby contributing to vascular endothelial damage and HSP occurrence. Proanthocyanidins are active compounds naturally enriched in fruits, vegetables and plants. Proanthocyanidins have diverse properties, including anti-inflammatory, antioxidant, antibacterial, immunoregulatory, anticarcinogenic and vascular protective effects. Proanthocyanidins are used in the management of various diseases. Proanthocyanidins regulate T cells, equilibrate immunity and arrest OS by inhibiting the TLR4/MyD88/NF-κB signaling pathway. Considering the pathogenesis of HSP and the properties of proanthocyanidins, the present study hypothesized that these compounds may potentially lead to HSP recovery through modulating the immune equilibrium and preventing OS by inhibiting the TLR4/MyD88/NF-κB pathway. To the best of our knowledge, however, little is known about the positive effects of proanthocyanidins against HSP. The present review summarizes the potential of proanthocyanidins to treat HSP.

A Nanomedicine Structure-Activity Framework for Research, Development, and Regulation of Future Cancer Therapies

Despite their clinical success in drug delivery applications, the potential of theranostic nanomedicines is hampered by mechanistic uncertainty and a lack of science-informed regulatory guidance. Both the therapeutic efficacy and the toxicity of nanoformulations are tightly controlled by the complex interplay of the nanoparticle's physicochemical properties and the individual patient/tumor biology; however, it can be difficult to correlate such information with observed outcomes. Additionally, as nanomedicine research attempts to gradually move away from large-scale animal testing, the need for computer-assisted solutions for evaluation will increase. Such models will depend on a clear understanding of structure-activity relationships. This review provides a comprehensive overview of the field of cancer nanomedicine and provides a knowledge framework and foundational interaction maps that can facilitate future research, assessments, and regulation. By forming three complementary maps profiling nanobio interactions and pathways at different levels of biological complexity, a clear picture of a nanoparticle's journey through the body and the therapeutic and adverse consequences of each potential interaction are presented.

Facet-Dependent Activity of CeO2 Nanozymes Regulate the Fate of Human Neural Progenitor Cell via Redox Homeostasis

Neural progenitor cells (NPCs) therapy, a promising therapeutic strategy for neurodegenerative diseases, has a huge challenge to ensure high survival rate and neuronal differentiation rate. Cerium oxide (CeO₂) nanoparticles exhibit multienzyme mimetic activities and have shown the capability of regulating reactive oxygen species (ROS), which is a pivotal mediator for intracellular redox homeostasis in NPCs, regulating biological processes including differentiation, proliferation, and apoptosis. In the present study, the role of facet-dependent CeO₂-mediated redox homeostasis in regulating self-renewal and differentiation of NPCs is reported for the first time. The cube-, rod-, and octahedron-shaped CeO₂ nanozymes with different facets are prepared. Among the mentioned nanozymes, the cube enclosed by the (100) facet exhibits the highest CAT-like activity, causing it to provide superior protection to NPCs from oxidative stress induced by H₂O₂; meanwhile, the octahedron enclosed by the (111) facet with the lowest CAT-like activity induces the most ROS production in ReNcell CX cells, which promotes neuronal differentiation by activated AKT/GSK-3β/β-catenin pathways. A further mechanistic study indicated that the electron density of the surface Ce atoms changed continuously with different crystal facets, which led to their different CAT-like activity and modulation of redox homeostasis in NPCs. Altogether, the different surface chemistry and atomic architecture of active sites on CeO₂ exert modulation of redox homeostasis and the fate of NPCs.

Recent trends and advances in polyindole-based nanocomposites as potential antimicrobial agents: a mini review

Infections caused by multi-drug resistant microbes are a big challenge to the medical field and it necessitates the need for new biomedical agents that can act as potential candidates against these pathogens. Several polyindole based nanocomposites were found to exhibit the ability to release reactive oxygen species (ROS) and hence they show excellent antimicrobial properties. The features of polyindole can be fine-tuned to make them potential alternatives to antibiotics and antifungal medicines. This review clearly portrays the antimicrobial properties of polyindole based nanocomposites, reported so far for biomedical applications. This review will give a clear insight into the scope and possibilities for further research on the biomedical applications of polyindole based nanocomposites.

Incorporation of Low Concentrations of Gold Nanoparticles: Complex Effects on Radiation Response and Fate of Cancer Cells

(1) Background: In oncology research, a long-standing discussion exists about pros and cons of metal nanoparticle-enhanced radiotherapy and real mechanisms behind the tumor cell response to irradiation (IR) in presence of gold nanoparticles (GNPs). A better understanding of this response is, however, necessary to develop more efficient and safety nanoparticle (NP) types designed to disturb specific processes in tumor cells. (2) Aims and Methods: We combined 3D confocal microscopy and super-resolution single molecule localization microscopy (SMLM) to analyze, at the multiscale, the early and late effects of 10 nm-GNPs on DNA double strand break (DSB) induction and repair in tumor cells exposed to different doses of photonic low-LET (linear energy transfer) radiation. The results were correlated to different aspects of short and long-term cell viability. SkBr3 breast cancer cells (selected for the highest incidence of this cancer type among all cancers in women, and because most breast tumors are treated with IR) were incubated with low concentrations of GNPs and irradiated with ⁶⁰Co γ-rays or 6 MV X-rays. In numerous post-irradiation (PI) times, ranging from 0.5 to 24 h PI, the cells were spatially (3D) fixed and labeled with specific antibodies against γH2AX, 53BP1 and H3K9me3. The extent of DSB induction, multi-parametric micro- and nano-morphology of γH2AX and 53BP1 repair foci, DSB repair kinetics, persistence of unrepaired DSBs, nanoscale clustering of γH2AX and nanoscale (hetero)chromatin re-organization were measured by means of the mentioned microscopy techniques in dependence of radiation dose and GNP concentration. (3) Results: The number of γH2AX/53BP1 signals increased after IR and an additional increase was observed in GNP-treated (GNP(+)) cells compared to untreated controls. However, this phenomenon reflected slight expansion of the G2-phase cell subpopulation in irradiated GNP(+) specimens instead of enhanced DNA damage induction by GNPs. This statement is further supported by some micro- and nano-morphological parameters of γH2AX/53BP1 foci, which slightly differed for cells irradiated in absence or presence of GNPs. At the nanoscale, Ripley’s distance frequency analysis of SMLM signal coordinate matrices also revealed relaxation of heterochromatin (H3K9me3) clusters upon IR. These changes were more prominent in presence of GNPs. The slight expansion of radiosensitive G2 cells correlated with mostly insignificant but systematic decrease in post-irradiation survival of GNP(+) cells. Interestingly, low GNP concentrations accelerated DSB repair kinetics; however, the numbers of persistent γH2AX/53BP1 repair foci were slightly increased in GNP(+) cells. (4) Conclusions: Low concentrations of 10-nm GNPs enhanced the G2/M cell cycle arrest and the proportion of radiosensitive G2 cells, but not the extent of DNA damage induction. GNPs also accelerated DSB repair kinetics and slightly increased presence of unrepaired γH2AX/53BP1 foci at 24 h PI. GNP-mediated cell effects correlated with slight radiosensitization of GNP(+) specimens, significant only for the highest radiation dose tested (4 Gy).

A Novel Green Preparation of Ag/RGO Nanocomposites with Highly Effective Anticancer Performance

The efficacy of current cancer therapies is limited due to several factors, including drug resistance and non-specific toxic effects. Due to their tuneable properties, silver nanoparticles (Ag NPs) and graphene derivative-based nanomaterials are now providing new hope to treat cancer with minimum side effects. Here, we report a simple, inexpensive, and eco-friendly protocol for the preparation of silver-reduced graphene oxide nanocomposites (Ag/RGO NCs) using orange peel extract. This work was planned to curtail the use of toxic chemicals, and improve the anticancer performance and cytocompatibility of Ag/RGO NCs. Aqueous extract of orange peels is abundant in phytochemicals that act as reducing and stabilizing agents for the green synthesis of Ag NPs and Ag/RGO NCs from silver nitrate and graphene oxide (GO). Moreover, the flavonoid present in orange peel is a potent anticancer agent. Green-prepared Ag NPs and Ag/RGO NCs were characterized by UV-visible spectrophotometry, transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and dynamic light scattering (DLS). The results of the anticancer study demonstrated that the killing potential of Ag/RGO NCs against human breast cancer (MCF7) and lung cancer (A549) cells was two-fold that of pure Ag NPs. Moreover, the cytocompatibility of Ag/RGO NCs in human normal breast epithelial (MCF10A) cells and normal lung fibroblasts (IMR90) was higher than that of pure Ag NPs. This mechanistic study indicated that Ag/RGO NCs induce toxicity in cancer cells through pro-oxidant reactive oxygen species generation and antioxidant glutathione depletion and provided a novel green synthesis of Ag/RGO NCs with highly effective anticancer performance and better cytocompatibility.

Facile Synthesis of Zn-Doped Bi2O3 Nanoparticles and Their Selective Cytotoxicity toward Cancer Cells

Bismuth (III) oxide nanoparticles (Bi2O3 NPs) have shown great potential for biomedical applications because of their tunable physicochemical properties. In this work, pure and Zn-doped (1 and 3 mol %) Bi2O3 NPs were synthesized by a facile chemical route and their cytotoxicity was examined in cancer cells and normal cells. The X-ray diffraction results show that the tetragonal phase of β-Bi2O3 remains unchanged after Zn-doping. Transmission electron microscopy and scanning electron microscopy images depicted that prepared particles were spherical with smooth surfaces and the homogeneous distribution of Zn in Bi2O3 with high-quality lattice fringes without distortion. Photoluminescence spectra revealed that intensity of Bi2O3 NPs decreases with increasing level of Zn-doping. Biological data showed that Zn-doped Bi2O3 NPs induce higher cytotoxicity to human lung (A549) and liver (HepG2) cancer cells as compared to pure Bi2O3 NPs, and cytotoxic intensity increases with increasing concentration of Zn-doping. Mechanistic data indicated that Zn-doped Bi2O3 NPs induce cytotoxicity in both types of cancer cells through the generation of reactive oxygen species and caspase-3 activation. On the other hand, biocompatibility of Zn-doped Bi2O3 NPs in normal cells (primary rat hepatocytes) was greater than that of pure Bi2O3 NPs and biocompatibility improves with increasing level of Zn-doping. Altogether, this is the first report highlighting the role of Zn-doping in the anticancer activity of Bi2O3 NPs. This study warrants further research on the antitumor activity of Zn-doped Bi2O3 NPs in suitable in vivo models.

Nanomaterials for the Diagnosis and Treatment of Head and Neck Cancers: A Review

Head and neck cancer (HNC) is a category of cancers that typically arise from the nose-, mouth-, and throat-lining squamous cells. The later stage of HNC diagnosis significantly affects the patient's survival rate. This makes it mandatory to diagnose this cancer with a suitable biomarker and imaging techniques at the earlier stages of growth. There are limitations to traditional technologies for early detection of HNC. Furthermore, the use of nanocarriers for delivering chemo-, radio-, and phototherapeutic drugs represents a promising approach for improving the outcome of HNC treatments. Several studies with nanostructures focus on the development of a targeted and sustained release of anticancer molecules with reduced side effects. Besides, nanovehicles could allow co-delivering of anticancer drugs for synergistic activity to counteract chemo- or radioresistance. Additionally, a new generation of smart nanomaterials with stimuli-responsive properties have been developed to distinguish between unique tumor conditions and healthy tissue. In this light, the present article reviews the mechanisms used by different nanostructures (metallic and metal oxide nanoparticles, polymeric nanoparticles, quantum dots, liposomes, nanomicelles, etc.) to improve cancer diagnosis and treatment, provides an up-to-date picture of the state of the art in this field, and highlights the major challenges for future improvements.

Remote control of magnetic nanocomplexes for delivery and destruction of cancer cells

Although nanotechnology advances have been exploited for a myriad of purposes, including cancer diagnostics and treatment, still there is little discussion about the mechanisms of remote control. Our main aim here is to explain the possibility of a magnetic field control over magnetic nanocomplexes to improve their delivery, controlled release and antitumor activity. In doing so we considered the nonlinear dynamics of magnetomechanical and magnetochemical effects based on free radical mechanisms in cancer development for future pre-clinical studies.

Biomedical Applications of Reactive Oxygen Species Generation by Metal Nanoparticles

The design, synthesis and characterization of new nanomaterials represents one of the most dynamic and transversal aspects of nanotechnology applications in the biomedical field. New synthetic and engineering improvements allow the design of a wide range of biocompatible nanostructured materials (NSMs) and nanoparticles (NPs) which, with or without additional chemical and/or biomolecular surface modifications, are more frequently employed in applications for successful diagnostic, drug delivery and therapeutic procedures. Metal-based nanoparticles (MNPs) including metal NPs, metal oxide NPs, quantum dots (QDs) and magnetic NPs, thanks to their physical and chemical properties have gained much traction for their functional use in biomedicine. In this review it is highlighted how the generation of reactive oxygen species (ROS), which in many respects could be considered a negative aspect of the interaction of MNPs with biological matter, may be a surprising nanotechnology weapon. From the exchange of knowledge between branches such as materials science, nanotechnology, engineering, biochemistry and medicine, researchers and clinicians are setting and standardizing treatments by tuning ROS production to induce cancer or microbial cell death.

Genetic perturbation of IFN-α transcriptional modulators in human endothelial cells uncovers pivotal regulators of angiogenesis

Interferon-α (IFN-α) comprises a family of 13 cytokines involved in the modulation of antiviral, immune, and anticancer responses by orchestrating a complex transcriptional network. The activation of IFN-α signaling pathway in endothelial cells results in decreased proliferation and migration, ultimately leading to suppression of angiogenesis. In this study, we knocked-down the expression of seven established or candidate modulators of IFN-α response in endothelial cells to reconstruct a gene regulatory network and to investigate the antiangiogenic activity of IFN-α. This genetic perturbation approach, along with the analysis of interferon-induced gene expression dynamics, highlighted a complex and highly interconnected network, in which the angiostatic chemokine C-X-C Motif Chemokine Ligand 10 (CXCL10) was a central node targeted by multiple modulators. IFN-α-induced secretion of CXCL10 protein by endothelial cells was blunted by the silencing of Signal Transducer and Activator of Transcription 1 (STAT1) and of Interferon Regulatory Factor 1 (IRF1) and it was exacerbated by the silencing of Ubiquitin Specific Peptidase 18 (USP18). In vitro sprouting assay, which mimics in vivo angiogenesis, confirmed STAT1 as a positive modulator and USP18 as a negative modulator of IFN-α-mediated sprouting suppression. Our data reveal an unprecedented physiological regulation of angiogenesis in endothelial cells through a tonic IFN-α signaling, whose enhancement could represent a viable strategy to suppress tumor neoangiogenesis.

Barium Titanate (BaTiO3) Nanoparticles Exert Cytotoxicity through Oxidative Stress in Human Lung Carcinoma (A549) Cells

Barium titanate (BaTiO3) nanoparticles (BT NPs) have shown exceptional characteristics such as high dielectric constant and suitable ferro-, piezo-, and pyro-electric properties. Thus, BT NPs have shown potential to be applied in various fields including electro-optical devices and biomedicine. However, very limited knowledge is available on the interaction of BT NPs with human cells. This work was planned to study the interaction of BT NPs with human lung carcinoma (A549) cells. Results showed that BT NPs decreased cell viability in a dose- and time-dependent manner. Depletion of mitochondrial membrane potential and induction of caspase-3 and -9 enzyme activity were also observed following BT NP exposure. BT NPs further induced oxidative stress indicated by induction of pro-oxidants (reactive oxygen species and hydrogen peroxide) and reduction of antioxidants (glutathione and several antioxidant enzymes). Moreover, BT NP-induced cytotoxicity and oxidative stress were effectively abrogated by N-acetyl-cysteine (an ROS scavenger), suggesting that BT NP-induced cytotoxicity was mediated through oxidative stress. Intriguingly, the underlying mechanism of cytotoxicity of BT NPs was similar to the mode of action of ZnO NPs. At the end, we found that BT NPs did not affect the non-cancerous human lung fibroblasts (IMR-90). Altogether, BT NPs selectively induced cytotoxicity in A549 cells via oxidative stress. This work warrants further research on selective cytotoxicity mechanisms of BT NPs in different types of cancer cells and their normal counterparts.

Caffeine Targets G6PDH to Disrupt Redox Homeostasis and Inhibit Renal Cell Carcinoma Proliferation

Glucose-6-phosphate dehydrogenase (G6PDH) is the rate-limiting enzyme in the pentose phosphate pathway (PPP) and plays a crucial role in the maintenance of redox homeostasis by producing nicotinamide adenine dinucleotide phosphate (NADPH), the major intracellular reductant. G6PDH has been shown to be a biomarker and potential therapeutic target for renal cell carcinoma (RCC). Here, we report a previously unknown biochemical mechanism through which caffeine, a well-known natural small molecule, regulates G6PDH activity to disrupt cellular redox homeostasis and suppress RCC development and progression. We found that caffeine can inhibit G6PDH enzymatic activity. Mechanistically, caffeine directly binds to G6PDH with high affinity (K _D = 0.1923 μM) and competes with the coenzyme NADP⁺ for G6PDH binding, as demonstrated by the decreased binding affinities of G6PDH for its coenzyme and substrate. Molecular docking studies revealed that caffeine binds to G6PDH at the structural NADP⁺ binding site, and chemical cross-linking analysis demonstrated that caffeine inhibits the formation of dimeric G6PDH. G6PDH inhibition abrogated the inhibitory effects of caffeine on RCC cell growth. Moreover, inhibition of G6PDH activity by caffeine led to a reduction in the intracellular levels of NADPH and reactive oxygen species (ROS), and altered the expression of redox-related proteins in RCC cells. Accordingly, caffeine could inhibit tumor growth through inhibition of G6PDH activity in vivo. Taken together, these results demonstrated that caffeine can target G6PDH to disrupt redox homeostasis and inhibit RCC tumor growth, and has potential as a therapeutic agent for the treatment of RCC.

Nitric Oxide Nano-Delivery Systems for Cancer Therapeutics: Advances and Challenges

Nitric oxide (NO) plays important roles in various physiological and pathological functions and processes in the human body. Therapeutic application of NO molecules has been investigated in various diseases, including cardiovascular disease, cancer, and infections. However, the extremely short half-life of NO, which limits its clinical use considerably, along with non-specific distribution, has resulted in a low therapeutic index and undesired adverse effects. To overcome the drawbacks of using this gaseous signaling molecule, researchers in the last several decades have focused on innovative medical technologies, specifically nanoparticle-based drug delivery systems (DDSs), because these systems alter the biodistribution of the therapeutic agent through controlled release at the target tissues, resulting in a significant therapeutic drug effect. Thus, the application of nano-systems for NO delivery in the field of biomedicine, particularly in the development of new drugs for cancer treatment, has been increasing worldwide. In this review, we discuss NO delivery nanoparticle systems, with the aim of improving drug delivery development for conventional chemotherapies and controlling multidrug resistance in cancer treatments.