The role of nitric oxide in tumour progression

Multifunctional Molecular Hybrids Photoreleasing Nitric Oxide: Advantages, Pitfalls, and Opportunities

The multifaceted role nitric oxide (NO) plays in human physiology and pathophysiology has opened new scenarios in biomedicine by exploiting this free radical as an unconventional therapeutic against important diseases. The difficulties in handling gaseous NO and the strict dependence of the biological effects on its doses and location have made the light-activated NO precursors, namely NO photodonors (NOPDs), very appealing by virtue of their precise spatiotemporal control of NO delivery. The covalent integration of NOPDs and additional functional components within the same molecular skeleton through suitable linkers can lead to an intriguing class of multifunctional photoactivatable molecular hybrids. In this Perspective, we provide an overview of the recent advances in these molecular constructs, emphasizing those merging NO photorelease with targeting, fluorescent reporting, and phototherapeutic functionalities. We will highlight the rational design behind synthesizing these molecular hybrids and critically describe the advantages, drawbacks, and opportunities they offer in biomedical research.

Supramolecular red-light-photosensitized nitric oxide release with fluorescence self-reporting within biocompatible nanocarriers

The strict dependence of the biological effects of nitric oxide (NO) on its concentration and generation site requires this inorganic free radical to be delivered with precise spatiotemporal control. Light-activation by suitable NO photoprecursors represents an ideal approach. Developing strategies to activate NO release using long-wavelength excitation light in the therapeutic window (650-1300 nm) is challenging. In this contribution, we demonstrate that NO release by a blue-light activatable NO photodonor (NOPD) with self-fluorescence reporting can be triggered catalytically by the much more biocompatible red light exploiting a supramolecular photosensitization process. Different red-light absorbing photosensitizers (PSs) are co-entrapped with the NOPD within different biocompatible nanocarriers such as Pluronic® micelles, microemulsions and branched cyclodextrin polymers. The intra-carrier photosensitized NO release, involving the lowest, long-lived triplet state of the PS as the key intermediate and its quenching by the NOPD, is competitive with that by molecular oxygen. This allows NO to be released with good efficacy, even under aerobic conditions. Therefore, the adopted general strategy provides a valuable tool for generating NO from an already available NOPD, otherwise activatable with the poorly biocompatible blue light, without requiring any chemical modification and using sophisticated and expensive irradiation sources.

Xanthene-Based Dyes for Photoacoustic Imaging and their Use as Analyte-Responsive Probes

Developing imaging tools that can report on the presence of disease-relevant analytes in multicellular organisms can provide insight into fundamental disease mechanisms as well as provide diagnostic tools for the clinic. Photoacoustic imaging (PAI) is a light-in, sound-out imaging technique that allows for high resolution, deep-tissue imaging with applications in pre-clinical and point-of-care settings. The continued development of near-infrared (NIR) absorbing small-molecule dyes promises to improve the capabilities of this emerging imaging modality. For example, new dye scaffolds bearing chemoselective functionalities are enabling the detection and quantification of disease-relevant analytes through activity-based sensing (ABS) approaches. Recently described strategies to engineer NIR absorbing xanthenes have enabled development of analyte-responsive PAI probes using this classic dye scaffold. Herein, we present current strategies for red-shifting the spectral properties of xanthenes via bridging heteroatom or auxochrome modifications. Additionally, we explore how these strategies, coupled with chemoselective spiroring-opening approaches, have been employed to create ABS probes for in vivo detection of hypochlorous acid, nitric oxide, copper (II), human NAD(P)H: quinone oxidoreductase isozyme 1, and carbon monoxide. Given the versatility of the xanthene scaffold, we anticipate continued growth and development of analyte-responsive PAI imaging probes based on this dye class.

Positron Emission Tomography of Nitric Oxide by a Specific Radical-Generating Dihydropyridine Tracer

Nitric oxide (NO) plays a pivotal role as a biological signaling molecule, presenting challenges in its specific detection and differentiation from other reactive nitrogen and oxygen species within living organisms. Herein, a 18F-labeled (fluorine-18, t1/2 = 109.7 min) small-molecule tracer dimethyl 4-(4-(4-[18F]fluorobutoxy)benzyl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate ([18F]BDHP) is developed based on the dihydropyridine scaffold for positron emission tomography (PET) imaging of NO in vivo. [18F]BDHP exhibits a highly sensitive and efficient C-C cleavage reaction specifically triggered by NO under physiological conditions, leading to the production of a 18F-labeled radical that is readily retained within the cells. High uptakes of [18F]BDHP are found within and around NO-generating cells, such as macrophages treated with lipopolysaccharide or benzo(a)pyrene. MicroPET/CT imaging of arthritic animal model mice reveals distinct tracer accumulation in the arthritic legs, showcasing a higher distribution of NO compared with the control legs. In summary, a specific radical-generating dihydropyridine tracer with a unique radical retention strategy has been established for the marking of NO in real-time in vivo.

Fluorescent small molecule donors

Small molecule donors (SMDs) play subtle roles in the signaling mechanism and disease treatments. While many excellent SMDs have been developed, dosage control, targeted delivery, spatiotemporal feedback, as well as the efficiency evaluation of small molecules are still key challenges. Accordingly, fluorescent small molecule donors (FSMDs) have emerged to meet these challenges. FSMDs enable controllable release and non-invasive real-time monitoring, providing significant advantages for drug development and clinical diagnosis. Integration of FSMDs with chemotherapeutic, photodynamic or photothermal properties can take full advantage of each mode to enhance therapeutic efficacy. Given the remarkable properties and the thriving development of FSMDs, we believe a review is needed to summarize the design, triggering strategies and tracking mechanisms of FSMDs. With this review, we compiled FSMDs for most small molecules (nitric oxide, carbon monoxide, hydrogen sulfide, sulfur dioxide, reactive oxygen species and formaldehyde), and discuss recent progress concerning their molecular design, structural classification, mechanisms of generation, triggered release, structure-activity relationships, and the fluorescence response mechanism. Firstly, from the large number of fluorescent small molecular donors available, we have organized the common structures for producing different types of small molecules, providing a general strategy for the development of FSMDs. Secondly, we have classified FSMDs in terms of the respective donor types and fluorophore structures. Thirdly, we discuss the mechanisms and factors associated with the controlled release of small molecules and the regulation of the fluorescence responses, from which universal guidelines for optical properties and structure rearrangement were established, mainly involving light-controlled, enzyme-activated, reactive oxygen species-triggered, biothiol-triggered, single-electron reduction, click chemistry, and other triggering mechanisms. Fourthly, representative applications of FSMDs for trackable release, and evaluation monitoring, as well as for visible in vivo treatment are outlined, to illustrate the potential of FSMDs in drug screening and precision medicine. Finally, we discuss the opportunities and remaining challenges for the development of FSMDs for practical and clinical applications, which we anticipate will stimulate the attention of researchers in the diverse fields of chemistry, pharmacology, chemical biology and clinical chemistry. With this review, we hope to impart new understanding thereby enabling the rapid development of the next generation of FSMDs.

Stepwise Nitric Oxide Release and Antibacterial Activity of a Nitric Oxide Photodonor Hosted within Cyclodextrin Branched Polymer Nanocarriers

A hydrophobic nitric oxide (NO) photodonor integrating both nitroso and nitro functionalities within its chromophoric skeleton has been synthesized. Excitation of this compound with blue light triggers the release of two NO molecules from the nitroso and the nitro functionalities via a stepwise mechanism. Encapsulation of the NO photodonor within biocompatible neutral, cationic, and anionic β-cyclodextrin branched polymers as suitable carriers leads to supramolecular nanoassemblies, which exhibit the same nature of the photochemical processes but NO photorelease performances enhanced by about 1 order of magnitude when compared with the free guest. Antibacterial tests carried out with methicillin-resistant Staphylococcus aureus and Acinetobacter baumannii demonstrate an effective antibacterial activity exclusively under light activation and point out a differentiated role of the polymeric nanocarriers in determining the outcome of the antibacterial photodynamic action.

Development and Evaluation of an Expedited System for Creation of Single Walled Carbon Nanotube Platforms

Single-walled carbon nanotubes (SWNT) have a strong and stable near-infrared (nIR) fluorescence that can be used to selectively detect target analytes, even at the single molecule level, through changes in either their fluorescence intensity or emission peak wavelength. SWNTs have been employed as NIR optical sensors for detecting a variety of analytes. However, high costs, long fabrication times, and poor distributions limit the current methods for immobilizing SWNT sensors on solid substrates. Recently, our group reported a protocol for SWNT immobilization with high fluorescence yield, longevity, fluorescence distribution, and sensor response, unfortunately this process takes 5 days to complete. Herein we report an improved method to immobilize SWNT sensors that only takes 2 days and results in higher fluorescence intensity while maintaining a high level of SWNT distribution. We performed surface morphology and chemical composition tests on the original and new synthesis methods and compared the sensor response rates. The development of this new method of attaching SWNT sensors to a platform allows for creation of a sensing system in just 2 days without sacrificing the advantageous characteristics of the original, 5-day platforms.

A fluorescent probe with an ultra-rapid response to nitric oxide

Nitric oxide (NO) is a diatomic inorganic free radical ubiquitous in mammalian tissues and cells that plays a multifaceted role in a variety of physiological and pathophysiological processes. The strict dependence of the biological effects of NO on its concentration makes its real-time monitoring crucial. In view of the reactivity of NO with multiple bio-targets, the development of NO sensors that associate a fast response rate with selectivity and sensitivity is very challenging. Herein we report a fluorescent NO probe based on a BODIPY fluorogenic unit covalently linked to a trimethoxy aniline derivative through a flexible spacer. NO leads to effective nitrosation of the highly electron-rich amino active site of the probe through the secondary oxide N2O3, resulting in an increase of BODIPY fluorescence quantum yield from Φf = 0.06 to Φf = 0.55, accompanied by significant changes in the relative amplitude of the fluorescence lifetimes. In situ generation of NO, achieved by a tailored light-activatable NO releaser, allows the real-time detection of NO as a function of its concentration and permits demonstrating that the probe exhibits a very fast response time, being ≤0.1 s. This remarkable data combines with the high sensitivity of the probe to NO (LOD = 35 nM), responsiveness also to ONOO-, the other important secondary oxide of NO, independence from the fluorescence response within a wide pH range, good selectivity towards different analytes and small interference by typical physiological concentrations of glutathione. Validation of this probe in melanoma cell lines is also reported.

A NIR-II Photoacoustic Probe for High Spatial Quantitative Imaging of Tumor Nitric Oxide in Vivo

Nitric oxide (NO) exhibits both pro- and anti-tumor effects. Therefore, real-time in vivo imaging and quantification of tumor NO dynamics are essential for understanding the conflicting roles of NO played in pathophysiology. The current molecular probes, however, cannot provide high-resolution imaging in deep tissues, making them unsuitable for these purposes. Herein, we designed a photoacoustic probe with an absorption maximum beyond 1000 nm for high spatial quantitative imaging of in vivo tumor NO dynamics. The probe exhibits remarkable sensitivity, selective ratiometric response behavior, and good tumor-targeting abilities, facilitating ratiometric imaging of tumor NO throughout tumor progression in a micron-resolution level. Using the probe as the imaging agent, we successfully quantified NO dynamics in tumor, liver and kidney. We have pinpointed an essential concentration threshold of around 80 nmol/cm3 for NO, which plays a crucial role in the "double-edged-sword" function of NO in tumors. Furthermore, we revealed a reciprocal relationship between the NO concentration in tumors and that in the liver, providing initial insights into the possible NO-mediated communication between tumor and the liver. We believe that the probe will help resolve conflicting aspects of NO biology and guide the design of imaging agents for tumor diagnosis and anti-cancer drug screening.

Review: The PI3K-AKT-mTOR signal transduction pathway in canine cancer

Tumors in dogs and humans share many similar molecular and genetic features, incentivizing a better understanding of canine neoplasms not only for the purpose of treating companion animals, but also to facilitate research of spontaneously developing tumors with similar biologic behavior and treatment approaches in an immunologically competent animal model. Multiple tumor types of both species have similar dysregulation of signal transduction through phosphatidylinositol 3-kinase (PI3K), protein kinase B (PKB; AKT), and mechanistic target of rapamycin (mTOR), collectively known as the PI3K-AKT-mTOR pathway. This review aims to delineate the pertinent aspects of the PI3K-AKT-mTOR signaling pathway in health and in tumor development. It will then present a synopsis of current understanding of PI3K-AKT-mTOR signaling in important canine cancers and advancements in targeted inhibitors of this pathway.

Bisphenols and brominated bisphenols induced endothelial dysfunction via its disruption of endothelial nitric oxide synthase

Emerging literatures have concentrated on the association between cardiovascular diseases risk of typical endocrine disruptor bisphenols, which also put forward the further studies need respect to the potential mechanism. Herein, we investigated the endothelial dysfunction effects of bisphenols and brominated bisphenols involved in aortic pathological structure, endothelial nitric oxide synthase (eNOS) protein phosphorylation, synthase activity and nitric oxide (NO) production in human umbilical vein endothelial cells (HUVECs) and C57BL/6 mice. Bisphenol A (BPA) and bisphenol S (BPS) increased NO production by 85.7% and 68.8% at 10-6 M level in vitro and 74.3%, 41.5% in vivo, respectively, while tetrabromobisphenol S (TBBPS) significantly inhibited NO by 55.7% at 10-6 M in vitro and 28.9% in vivo at dose of 20 mg/kg BW/d. Aortic transcriptome profiling revealed that the process of 'regulation of NO mediated signal transduction' was commonly induced. The mRNA and protein expression of phosphorylated eNOS at Ser1177 were promoted by BPA and BPS but decreased by TBBPA and TBBPS in HUVECs. Phosphorylation and enzymatic activity of eNOS were significantly increased by 43.4% and 13.8% with the treatment of BPA and BPS at 10-7 M, but decreased by 16.9% after exposure to TBBPS at 10-6 M in vitro. Moreover, only TBBPS was observed to increase aorta thickness significantly in mice and induce endothelial dysfunction. Our work suggests that bisphenols and brominated bisphenols may exert adverse outcome on vascular health differently in vitro and in vivo, and emphasizes areas of public health concern similar endocrine disruptors vulnerable on the vascular endothelial function.

Recent advances on the development of NO-releasing molecules (NORMs) for biomedical applications

Nitric oxide (NO) is an important biological messenger as well as a signaling molecule that participates in a broad range of physiological events and therapeutic applications in biological systems. However, due to its very short half-life in physiological conditions, its therapeutic applications are restricted. Efforts have been made to develop an enormous number of NO-releasing molecules (NORMs) and motifs for NO delivery to the target tissues. These NORMs involve organic nitrate, nitrite, nitro compounds, transition metal nitrosyls, and several nanomaterials. The controlled release of NO from these NORMs to the specific site requires several external stimuli like light, sound, pH, heat, enzyme, etc. Herein, we have provided a comprehensive review of the biochemistry of nitric oxide, recent advancements in NO-releasing materials with the appropriate stimuli of NO release, and their biomedical applications in cancer and other disease control.

Engineered Bacterial Biomimetic Vesicles Reprogram Tumor-Associated Macrophages and Remodel Tumor Microenvironment to Promote Innate and Adaptive Antitumor Immune Responses

Tumor-associated macrophages (TAMs) are among the most abundant infiltrating leukocytes in the tumor microenvironment (TME). Reprogramming TAMs from protumor M2 to antitumor M1 phenotype is a promising strategy for remodeling the TME and promoting antitumor immunity; however, the development of an efficient strategy remains challenging. Here, a genetically modified bacterial biomimetic vesicle (BBV) with IFN-γ exposed on the surface in a nanoassembling membrane pore structure was constructed. The engineered IFN-γ BBV featured a nanoscale structure of protein and lipid vesicle, the existence of rich pattern-associated molecular patterns (PAMPs), and the costimulation of introduced IFN-γ molecules. In vitro, IFN-γ BBV reprogrammed M2 macrophages to M1, possibly through NF-κB and JAK-STAT signaling pathways, releasing nitric oxide (NO) and inflammatory cytokines IL-1β, IL-6, and TNF-α and increasing the expression of IL-12 and iNOS. In tumor-bearing mice, IFN-γ BBV demonstrated a targeted enrichment in tumors and successfully reprogrammed TAMs into the M1 phenotype; notably, the response of antigen-specific cytotoxic T lymphocyte (CTL) in TME was promoted while the immunosuppressive myeloid-derived suppressor cell (MDSC) was suppressed. The tumor growth was found to be significantly inhibited in both a TC-1 tumor and a CT26 tumor. It was indicated that the antitumor effects of IFN-γ BBV were macrophage-dependent. Further, the modulation of TME by IFN-γ BBV produced synergistic effects against tumor growth and metastasis with an immune checkpoint inhibitor in an orthotopic 4T1 breast cancer model which was insensitive to anti-PD-1 mAb alone. In conclusion, IFN-γ-modified BBV demonstrated a strong capability of efficiently targeting tumor and tuning a cold tumor hot through reprogramming TAMs, providing a potent approach for tumor immunotherapy.

Potential anticancer effect of free and nanoformulated Deferasirox for breast cancer treatment: in-vitro and in-vivo evaluation

BACKGROUND

Breast cancer (BC) stands as the second-leading cause of mortality among women worldwide. Many chemotherapeutic treatments for BC come with significant adverse effects. Additionally, BC is recognized as one of the most resistant forms of malignancy to treatment. Consequently, there exists a critical need for innovative therapeutic agents that are both highly effective and exhibit reduced toxicity and side effects for patients. Deferasirox (DFX), an iron-chelating drug approved by the FDA for oral use, emerges as a promising contender in the fight against BC proliferation. DFX, primarily administered orally, is utilized to address chronic iron excess resulting from blood transfusions, and it is the inaugural treatment for chronic iron overload syndrome. However, DFX encounters limitations due to its poor water solubility.

AIM

This study aimed at incorporating DFX into lipid nanocapsules (DFX-LNCs) followed by investigating the anticancer effect of the DFX nanoform as compared to free DFX in-vitro and on an orthotopic BC mouse model in-vivo.

METHODS

The DFX-LNCs was prepared and imaged using TEM and also characterized in terms of particle size (PS), zeta potential (ZP), and polydispersity index (PDI) using DLS. Moreover, drug release, cytotoxicity, and anticancer effect were assessed in-vitro, and in-vivo.

RESULTS

The results revealed that DFX-LNCs are more cytotoxic than free DFX with IC50 of 4.417 µg/ml and 16.114 µg/ml, respectively, while the plain LNCs didn't show any cytotoxic effect on the 4T1 cell line (IC50 = 122.797 µg/ml). Besides, the apoptotic effect of DFX-LNCs was more pronounced than that of free DFX, as evidenced by Annexin V/PI staining, increased BAX expression, and decreased expression of BcL-2. Moreover, DFX-LNCs showed a superior antitumor effect in-vivo with potent antioxidant and anti-proliferative effects.

CONCLUSION

The newly developed DFX nanoform demonstrated a high potential as a promising therapeutic agent for BC treatment.

Activity-Based Nitric Oxide-Responsive Porphyrin for Site-Selective and Nascent Cancer Ablation

Nitric oxide (NO) generated within the tumor microenvironment is an established driver of cancer progression and metastasis. Recent efforts have focused on leveraging this feature to target cancer through the development of diagnostic imaging agents and activatable chemotherapeutics. In this context, porphyrins represent an extraordinarily promising class of molecules, owing to their demonstrated use within both modalities. However, the remodeling of a standard porphyrin to afford a responsive chemical that can distinguish elevated NO from physiological levels has remained a significant research challenge. In this study, we employed a photoinduced electron transfer strategy to develop a panel of NO-activatable porphyrin photosensitizers (NOxPorfins) augmented with real-time fluorescence monitoring capabilities. The lead compound, NOxPorfin-1, features an o-phenylenediamine trigger that can effectively capture NO (via N2O3) to yield a triazole product that exhibits a 7.5-fold enhancement and a 70-fold turn-on response in the singlet oxygen quantum yield and fluorescence signal, respectively. Beyond demonstrating excellent in vitro responsiveness and selectivity toward NO, we showcase the potent photodynamic therapy (PDT) effect of NOxPorfin-1 in murine breast cancer and human non-small cellular lung cancer cells. Further, to highlight the in vivo efficacy, two key studies were executed. First, we utilized NOxPorfin-1 to ablate murine breast tumors in a site-selective manner without causing substantial collateral damage to healthy tissue. Second, we established a nascent human lung cancer model to demonstrate the unprecedented ability of NOxPorfin-1 to halt tumor growth and progression completely. The results of the latter study have tremendous implications for applying PDT to target metastatic lesions.

Innovations in Molecular Biomarkers and Biomaterial-Based Immunotherapies for Head & Neck Cancer

Purpose of Review

Oral squamous cell carcinoma (OSCC) survival rates have remained stagnant due to a lack of targeted therapies and diagnostic tools. Patient risk is currently determined solely through clinicopathologic features, primarily tumor staging, which lacks the necessary precision to stratify patients by risk and accurately dictate adjuvant treatment. Similarly, conventional OSCC therapies have well-established toxicities and limited efficacy.

Recent Findings

Recent studies show that patient risk can now be assessed using non-invasive techniques, at earlier time points, and with greater accuracy using molecular biomarker panels. Additionally, novel immunotherapies not only utilize the host's immune response to combat disease but also have the potential to form immunological memory to prevent future recurrence. Localized controlled-release formulas have further served to reduce toxicity and allow the de-escalation of other treatment modalities.

Summary

We review the latest advances in head and neck cancer diagnosis and treatment, including novel molecular biomarkers and immunotherapies.

Biopterin metabolism and nitric oxide recoupling in cancer

Tetrahydrobiopterin is a cofactor necessary for the activity of several enzymes, the most studied of which is nitric oxide synthase. The role of this cofactor-enzyme relationship in vascular biology is well established. Recently, tetrahydrobiopterin metabolism has received increasing attention in the field of cancer immunology and immunotherapy due to its involvement in the cytotoxic T cell response. Past research has demonstrated that when the availability of BH4 is low, as it is in chronic inflammatory conditions and tumors, electron transfer in the active site of nitric oxide synthase becomes uncoupled from the oxidation of arginine. This results in the production of radical species that are capable of a direct attack on tetrahydrobiopterin, further depleting its local availability. This feedforward loop may act like a molecular switch, reinforcing low tetrahydrobiopterin levels leading to altered NO signaling, restrained immune effector activity, and perpetual vascular inflammation within the tumor microenvironment. In this review, we discuss the evidence for this underappreciated mechanism in different aspects of tumor progression and therapeutic responses. Furthermore, we discuss the preclinical evidence supporting a clinical role for tetrahydrobiopterin supplementation to enhance immunotherapy and radiotherapy for solid tumors and the potential safety concerns.

Mitochondria-targetable small molecule fluorescent probes for the detection of cancer-associated biomarkers: A review

Cancer represents a global threat to human health, and effective strategies for improved cancer early diagnosis and treatment are urgently needed. The detection of tumor biomarkers has been one of the important auxiliary means for tumor screening and diagnosis. Mitochondria are crucial subcellular organelles that produce most chemical energy used by cells, control metabolic processes, and maintain cell function. Evidence suggests the close involvement of mitochondria with cancer development. As a consequence, the identification of cancer-associated biomarker expression levels in mitochondria holds significant importance in the diagnosis of early-stage diseases and the monitoring of therapy efficacy. Small-molecule fluorescent probes are effective for the identification and visualization of bioactive entities within biological systems, owing to their heightened sensitivity, expeditious non-invasive analysis and real-time detection capacities. The design principles and sensing mechanisms of mitochondrial targeted fluorescent probes are summarized in this review. Additionally, the biomedical applications of these probes for detecting cancer-associated biomarkers are highlighted. The limitations and challenges of fluorescent probes in vivo are also considered and some future perspectives are provided. This review is expected to provide valuable insights for the future development of novel fluorescent probes for clinical imaging, thereby contributing to the advancement of cancer diagnosis and treatment.

Pro-fluorescent probe with morpholine moiety and its reactivity towards selected biological oxidants

Biological oxidants participate in many processes in the human body. Their excessive production causes organelle damage, which may result in the accumulation of cytotoxic mediators and cell degradation and may manifest itself in various diseases. Peroxynitrite (ONOO- ), hypochlorous acid (HOCl), hydrogen peroxide (H2 O2 ), and peroxymonocarbonate (HOOCO2 - ) are important oxidants in biology, toxicology, and various pathologies. Derivatives of coumarin, containing an oxidant-sensitive boronate group, have been recently developed for the fluorescent detection of inflammatory oxidants. Here, we report the synthesis and characterization of 4-[2-(morpholin-4-yl)-2-oxoethyl]-2-oxo-2H-chromen-7-yl boronic acid (MpC-BA) as a fluorescent probe for the detection of oxidants, with better solubility in water, high stability and fast response time toward peroxynitrite and hypochlorous acid. The effectiveness of the MpC-BA probe for the detection of peroxynitrite was measured by adding bolus ONOO- or using the co-generating superoxide and nitrogen oxide system. MpC-BA is oxidized by ONOO- to 7-hydroxy-4-[2-(morpholin-4-yl)-2-oxoethyl]-2H-chromen-2-one (MpC-OH). However, peroxynitrite-specific product (MpC-H) is formed in the minor reaction pathway. MpC-OH is also yielded in the reaction of MpC-BA with HOCl, and the subsequent formation of a chlorinated MpC-OH gives a specific product for HOCl (MpC-OHCl). H2 O2 slowly oxidizes MpC-BA. However, the addition of NaHCO3 increased the MpC-OH formation rate. We conclude that MpC-BA is potentially an improved fluorescent probe detecting peroxynitrite and hypochlorite in biological settings. Complementation of the fluorescence measurements by HPLC-based identification of chlorinated and reduced coumarin(s) will help identify the oxidants detected.

Bioinspired Lipoproteins of Furoxans-Gemcitabine Preferentially Targets Glioblastoma and Overcomes Radiotherapy Resistance

Radiotherapy (RT) resistance is an enormous challenge in glioblastoma multiforme (GBM) treatment, which is largely associated with DNA repair, poor distribution of reactive radicals in tumors, and limited delivery of radiosensitizers to the tumor sites. Inspired by the aberrant upregulation of RAD51 (a critical protein of DNA repair), scavenger receptor B type 1 (SR-B1), and C-C motif chemokine ligand 5 (CCL5) in GBM patients, a reduction-sensitive nitric oxide (NO) donor conjugate of gemcitabine (RAD51 inhibitor) (NG) is synthesized as radio-sensitizer and a CCL5 peptide-modified bioinspired lipoprotein system of NG (C-LNG) is rationally designed, aiming to preferentially target the tumor sites and overcome the RT resistance. C-LNG can preferentially accumulate at the orthotopic GBM tumor sites with considerable intratumor permeation, responsively release the gemcitabine and NO, and then generate abundant peroxynitrite (ONOO- ) upon X-ray radiation, thereby producing a 99.64% inhibition of tumor growth and a 71.44% survival rate at 120 days in GL261-induced orthotopic GBM tumor model. Therefore, the rationally designed bioinspired lipoprotein of NG provides an essential strategy to target GBM and overcome RT resistance.

Self-Assembled Activatable Probes to Monitor Interactive Dynamics of Intracellular Nitric Oxide and Hydrogen Sulfide

The increasing understanding of the intricate relationship between two crucial gasotransmitters nitric oxide (NO) and hydrogen sulfide (H2S) in biological actions has generated significant interest. However, comprehensive monitoring of the dynamic fluctuations of endogenous NO and H2S remains a challenge. In this study, we have designed an innovative aggregation-induced reporter SAB-NH-SC with enhanced responsiveness to H2S for visualizing the fluctuations of intracellular NO and H2S. This probe leverages the hydrophilic properties of the pyridinium salt derivative, which can rapidly self-assemble into positively charged nanoparticles under physiological conditions, avoiding the introduction of organic solvents or tedious preparations. Notably, the reporter can repeatedly cycle S-nitrosation and SNO-transnitrosation reactions when successively treated with NO and H2S. Consequently, fluorescence alternation at 751 (H2S) and 639 nm (NO) facilitates the dynamic visualization of the alternating presence of H2S and NO within cells. This dynamic and reversible probe holds immense potential for unraveling the intricate interactions between NO and H2S in a complex network of biological applications.

Nitric Oxide-Releasing Tubular Polymersomes toward Advanced Gas Therapeutic Carriers

Nitric oxide (NO) not only plays a vital role in a series of physiological processes but also has great potential for therapeutic applications. One of the existing challenges in using NO as a gas therapeutic is the inconvenience of gaseous NO storage, and thus, it is of importance to develop NO-releasing vehicle platforms. Although a variety of polymer-based NO-releasing nanoparticles have been constructed, a majority of the systems are limited to spherical morphologies. Here we present the preparation of biodegradable NO-releasing amphiphilic block copolymers containing poly(ethylene glycol) (PEG) and poly(trimethylene carbonate-4-nitro-3-(trifluoromethyl)) (PTMC-NF), which can self-assemble into tubular polymersomes. The tubular polymersomes with high aspect ratio structures showed much faster NO-releasing behavior, in contrast to their spherical counterparts under light irradiation. We found that the amount of NO released from tubular polymersomes is 1.5 times that from spherical polymersomes. More importantly, the tubular polymersomes have an enhanced anticancer performance compared to spherical polymersomes, demonstrating that the morphology of the NO-releasing polymersomes has a significant effect on their anticancer ability. In view of the benefits of NO-releasing tubular polymersomes, we expect that they can be used as an efficient NO delivery system for enhanced gas therapy.

Current trends in gas-synergized phototherapy for improved antitumor theranostics

Phototherapy, such as photothermal therapy (PTT) and photodynamic therapy (PDT), has been considered an elegant solution to eradicate tumors due to its minimal invasiveness and low systemic toxicity. Nevertheless, it is still challenging for phototherapy to achieve ideal outcomes and clinical translation due to its inherent drawbacks. Owing to the unique biological functions, diverse gases have attracted growing attention in combining with phototherapy to achieve super-additive therapeutic effects. Specifically, gases such as nitric oxide (NO), carbon monoxide (CO), and hydrogen sulfide (H2S) have been proven to kill tumor cells by inducing mitochondrial damage in synergy with phototherapy. Additionally, several gases not only enhance the thermal damage in PTT and the reactive oxygen species (ROS) production in PDT but also improve the tumor accumulation of photoactive agents. The inflammatory responses triggered by hyperthermia in PTT are also suppressed by the combination of gases. Herein, we comprehensively review the latest studies on gas-synergized phototherapy for cancer therapy, including (1) synergistic mechanisms of combining gases with phototherapy; (2) design of nanoplatforms for gas-synergized phototherapy; (3) multimodal therapy based on gas-synergized phototherapy; (4) imaging-guided gas-synergized phototherapy. Finally, the current challenges and future opportunities of gas-synergized phototherapy for tumor treatment are discussed. STATEMENT OF SIGNIFICANCE: 1. The novelty and significance of the work with respect to the existing literature. (1) Strategies to design nanoplatforms for gas-synergized anti-tumor phototherapy have been summarized for the first time. Meanwhile, the integration of various imaging technologies and therapy modalities which endow these nanoplatforms with advanced theranostic capabilities has been summarized. (2) The mechanisms by which gases synergize with phototherapy to eradicate tumors are innovatively and comprehensively summarized. 2. The scientific impact and interest. This review elaborates current trends in gas-synergized anti-tumor phototherapy, with special emphases on synergistic anti-tumor mechanisms and rational design of therapeutic nanoplatforms to achieve this synergistic therapy. It aims to provide valuable guidance for researchers in this field.

The Role of Amino Acids in Non-Enzymatic Antioxidant Mechanisms in Cancer: A Review

Currently, the antioxidant properties of amino acids and their role in the physicochemical processes accompanying oxidative stress in cancer remain unclear. Cancer cells are known to extensively uptake amino acids, which are used as an energy source, antioxidant precursors that reduce oxidative stress in cancer, and as regulators of inhibiting or inducing tumor cell-associated gene expression. This review examines nine amino acids (Cys, His, Phe, Met, Trp, Tyr, Pro, Arg, Lys), which play a key role in the non-enzymatic oxidative process in various cancers. Conventionally, these amino acids can be divided into two groups, in one of which the activity increases (Cys, Phe, Met, Pro, Arg, Lys) in cancer, and in the other, it decreases (His, Trp, Tyr). The review examines changes in the metabolism of nine amino acids in eleven types of oncology. We have identified the main nonspecific mechanisms of changes in the metabolic activity of amino acids, and described direct and indirect effects on the redox homeostasis of cells. In the future, this will help to understand better the nature of life of a cancer cell and identify therapeutic targets more effectively.

Smart Lipid Nanoparticle that Remodels Tumor Microenvironment for Activatable H2S Gas and Photodynamic Immunotherapy

Hydrogen sulfide (H2S) has shown promise for gas therapy. However, it is still controversial whether H2S can remodel the tumor microenvironment (TME) and induce robust antitumor immunity. Here, a tumor-targeting and TME-responsive "smart" lipid nanoparticle (1-JK-PS-FA) is presented, which is capable of delivering and releasing H2S specifically in tumor tissues for on-demand H2S gas and photodynamic immunotherapy. 1-JK-PS-FA enables a burst release of H2S in the acidic TME, which promptly reduces the embedded organic electrochromic materials and consequently switches on near-infrared fluorescence and photodynamic activity. Furthermore, we found that high levels of H2S can reprogram the TME by reducing tumor interstitial fluid pressure, promoting angiogenesis, increasing vascular permeability, ameliorating hypoxia, and reducing immunosuppressive conditions. This leads to increased tumor uptake of 1-JK-PS-FA, thereby enhancing PDT efficacy and eliciting strong immunogenic cell death during 808 nm laser irradiation. Therefore, 1-JK-PS-FA permits synergistic H2S gas and photodynamic immunotherapy, effectively eradicating orthotopic breast tumors and preventing tumor metastasis and recurrence. This work showcases the capacity of H2S to reprogram the TME to enhance H2S gas and immunotherapy.

Molecular and metabolic orchestration of the lymphatic vasculature in physiology and pathology

Lymphangiogenesis refers to the generation of new lymphatic vessels from pre-existing ones. During development and particular adult states, lymphatic endothelial cells (LEC) undergo reprogramming of their transcriptomic and signaling networks to support the high demands imposed by cell proliferation and migration. Although there has been substantial progress in identifying growth factors and signaling pathways controlling lymphangiogenesis in the last decades, insights into the role of metabolism in lymphatic cell functions are just emerging. Despite numerous similarities between the main metabolic pathways existing in LECs, blood ECs (BEC) and other cell types, accumulating evidence has revealed that LECs acquire a unique metabolic signature during lymphangiogenesis, and their metabolic engine is intertwined with molecular regulatory networks, resulting in a tightly regulated and interconnected process. Considering the implication of lymphatic dysfunction in cancer and lymphedema, alongside other pathologies, recent findings hold promising opportunities to develop novel therapeutic approaches. In this review, we provide an overview of the status of knowledge in the molecular and metabolic network regulating the lymphatic vasculature in health and disease.

Disturbances in Nitric Oxide Cycle and Related Molecular Pathways in Clear Cell Renal Cell Carcinoma

It is important to note that maintaining adequate levels of nitric oxide (NO), the turnover, and the oxidation level of nitrogen are essential for the optimal progression of cellular processes, and alterations in the NO cycle indicate a crucial step in the onset and progression of multiple diseases. Cellular accumulation of NO and reactive nitrogen species in many types of tumour cells is expressed by an increased susceptibility to oxidative stress in the tumour microenvironment. Clear cell renal cell carcinoma (ccRCC) is a progressive metabolic disease in which tumour cells can adapt to metabolic reprogramming to enhance NO production in the tumour space. Understanding the factors governing NO biosynthesis metabolites in ccRCC represents a relevant, valuable approach to studying NO-based anticancer therapy. Exploring the molecular processes mediated by NO, related disturbances in molecular pathways, and NO-mediated signalling pathways in ccRCC could have significant therapeutic implications in managing and treating this condition.

A CaCO3-based nanoplatform with sonodynamic and tumor microenvironment activated for combined in vitro cancer therapy

INTRODUCTION

Sonodynamic therapy (SDT) has potential clinical applications for cancer therapy, and is yet restricted by complex tumor microenvironmental (TME) factors. Thus, the research problem of TME modulation as well as efficient tumor treatment still needs to be clarified.

METHOD

In this study, a calcium carbonate (CaCO3) nanoplatform was designed for ultrasound (US) and TME response-triggered, which encapsulated Ag2S and loaded with l-Arg, and further wrapped with RBC/Platelet membrane, named as QD@Ca/ML-Arg.

RESULTS

Non-invasive US-triggered SDT by Ag2S and acidic environment-responsive drug release were achieved. In vitro experiments validated the efficacy of SDT, Ca-ion interference and nitric oxide (NO) gas therapy as combined therapy for cancer treatment. By means of RNA sequencing, the cancer therapeutic mechanism of SDT in redox-related pathways was elucidated. The immunosuppressive TME was simulated with a M2-macrophage/cancer cell co-culture system to confirm the immune activating effect of immunogenic cell death (ICD).

CONCLUSION

Accordingly, the potential of QD@Ca/ML-Arg-was demonstrated for in vitro TME modulation, cancer therapeutic efficacy and clinical translation.

Effects of S-Adenosylhomocysteine Hydrolase Downregulation on Wnt Signaling Pathway in SW480 Cells

S-adenosylhomocysteine hydrolase (AHCY) deficiency results mainly in hypermethioninemia, developmental delay, and is potentially fatal. In order to shed new light on molecular aspects of AHCY deficiency, in particular any changes at transcriptome level, we enabled knockdown of AHCY expression in the colon cancer cell line SW480 to simulate the environment occurring in AHCY deficient individuals. The SW480 cell line is well known for elevated AHCY expression, and thereby represents a suitable model system, in particular as AHCY expression is regulated by MYC, which, on the other hand, is involved in Wnt signaling and the regulation of Wnt-related genes, such as the β-catenin co-transcription factor LEF1 (lymphoid enhancer-binding factor 1). We selected LEF1 as a potential target to investigate its association with S-adenosylhomocysteine hydrolase deficiency. This decision was prompted by our analysis of RNA-Seq data, which revealed significant changes in the expression of genes related to the Wnt signaling pathway and genes involved in processes responsible for epithelial-mesenchymal transition (EMT) and cell proliferation. Notably, LEF1 emerged as a common factor in these processes, showing increased expression both on mRNA and protein levels. Additionally, we show alterations in interconnected signaling pathways linked to LEF1, causing gene expression changes with broad effects on cell cycle regulation, tumor microenvironment, and implications to cell invasion and metastasis. In summary, we provide a new link between AHCY deficiency and LEF1 serving as a mediator of changes to the Wnt signaling pathway, thereby indicating potential connections of AHCY expression and cancer cell phenotype, as Wnt signaling is frequently associated with cancer development, including colorectal cancer (CRC).

AS1411 aptamer tagged PEGylated liposomes as a smart nanocarrier for tumor-specific delivery of Withaferin A for mitigating pulmonary metastasis

Metastasis is the most challenging health problem contributing to about 90 % of cancer-related deaths worldwide. Metastatic tumors are highly aggressive and resistant to the most available therapeutic options. Hence, innovative therapeutic approaches are required to target metastatic tumors selectively. In this study, we prepared AS1411 functionalized Withaferin A loaded PEGylated nanoliposomes (ALW) and investigated its therapeutic effect in B16F10 induced in pulmonary metastasis mice models. The prepared formulations' size and morphological properties were evaluated using dynamic light scattering system and Transmission electron microscope. ALW had spherical-shaped nanosized particles with a size of 118 nm and an encapsulation efficacy of 82.5 %. TEM analysis data indicated that ALW has excellent dispersibility and uniform spherical nano-size particles. ALW inhibited cell viability, and induced cell apoptosis of B16F10. In vivo, the pulmonary metastasis study in C57BL/6 mice revealed that the ALW significantly (p < 0.01) improved the encapsulated WA anti-metastatic activity and survival rate compared to WA or LW treated groups. ALW significantly (p < 0.01) downregulated the levels of IL-6, TNF-α, and IL-1β and significantly reduced the lung collagen hydroxyproline, hexosamine, and uronic acid content in metastatic tumor bearing animals compared to WA or LW. Gene expression levels of MMPs and NF-κB were downregulated in ALW treated metastatic pulmonary tumor-bearing mice. These findings demonstrate that the AS1411 functionalized Withaferin A loaded PEGylated nanoliposomes could be a promising nanoliposomal formulation for targeting metastatic tumors.

Insights on the functional dualism of nitric oxide in the hallmarks of cancer

Nitric oxide (NO), a gaseous radical, governs a variety of physiological and pathological processes, including cancer, pro-inflammatory signalling, and vasodilation. The family of nitric oxide synthases (NOS), which comprises the constitutive forms, nNOS and eNOS, and the inducible form, iNOS, produces NO enzymatically. Additionally, NO can be generated non-enzymatically from the nitrate-nitrite-NO pathway. The anti- and pro-oxidant properties of NO and its functional dualism in cancer is due to its highly reactive nature. Numerous malignancies have NOS expression, which interferes with the tumour microenvironment to modulate the tumour's growth in both favourable and unfavourable ways. NO regulates a number of mechanisms in the tumour microenvironment, including metabolism, cell cycle, DNA repair, angiogenesis, and apoptosis/necrosis, depending on its concentration and spatiotemporal profile. This review focuses on the bi-modal impact of nitric oxide on the alteration of a few cancer hallmarks.

A Mitochondria-Localized Iridium(III) Complex for Simultaneous Two-Photon Phosphorescence Lifetime Imaging of Downstream Products N2O3 and ONOO- of Endogenous Nitric Oxide

Nitric oxide (NO) serves as a ubiquitous and fundamental signaling molecule involved in intricate effects on both physiological and pathological processes. NO, biosynthesized by nitric oxide synthase (NOS) or generated from nitrite, can form nitrosation reagent N2O3 (4NO + O2 = 2N2O3) through its oxidation or quickly produce peroxynitrite anion ONOO- (NO + •O2- = ONOO-) by reacting with superoxide anion (•O2-). However, most of the existing luminescent probes for NO just focus on specificity and utilize only a single signal to distinguish products N2O3 or ONOO-. In most of the present work, they differentiate one product from another simply by fluorescence signal or fluorescence intensity, which is not enough to distinguish accurately the behavior of NO in living cells. Herein, a new mitochondria-targeted and two-photon near-infrared (NIR) phosphorescent iridium(III) complex, known as Ir-NBD, has been designed for accurate detection and simultaneous imaging of two downstream products of endogenous NO, i.e., N2O3 and ONOO-. Ir-NBD exhibits a rapid response to N2O3 and ONOO- in enhanced phosphorescence intensity, increased phosphorescence lifetime, and an exceptionally high two-photon cross-section, reaching values of 78 and 85 GM, respectively, after the reaction. Furthermore, we employed multiple imaging methods, phosphorescence intensity imaging, and phosphorescence lifetime imaging together to image even distinguish N2O3 and ONOO- by probe Ir-NBD. Thus, coupled with its excellent photometrics, Ir-NBD enabled the detection of the basal level of intracellular NO accurately by responding to N2O3 and ONOO- in the lipopolysaccharide-stimulated macrophage model in virtue of fluorescence signal and phosphorescence lifetime imaging, revealing precisely the endogenous mitochondrial NO distribution during inflammation in a cell environment.

Contributions of viral oncogenes of HPV-18 and hypoxia to oxidative stress and genetic damage in human keratinocytes

Infection with high-risk human papillomaviruses like HPV-16 and HPV-18 is highly associated with the development of cervical and other cancers. Malignant transformation requires viral oncoproteins E5, E6 and E7, which promote cell proliferation and increase DNA damage. Oxidative stress and hypoxia are also key factors in cervical malignant transformation. Increased levels of reactive species of oxygen (ROS) and nitrogen (RNS) are found in the hypoxic tumor microenvironment, promoting genetic instability and invasiveness. In this work, we studied the combined effect of E5, E6 and E7 and hypoxia in increasing oxidative stress and promoting DNA damage and nuclear architecture alterations. HaCaT cells containing HPV-18 viral oncogenes (HaCaT E5/E6/E7-18) showed higher ROS levels in normoxia and higher levels of RNS in hypoxia compared to HaCaT parental cells, as well as higher genetic damage in hypoxia as measured by γH2AX and comet assays. In hypoxia, HaCaT E5/E6/E7-18 increased its nuclear dry mass and both cell types displayed marked heterogeneity in nuclear dry mass distribution and increased nuclear foci. Our results show contributions of both viral oncogenes and hypoxia to oxidative stress, DNA damage and altered nuclear architecture, exemplifying how an altered microenvironment combines with oncogenic transformation to promote tumor progression.

Mechanisms and Application of Gas-Based Anticancer Therapies

Cancer is still one of the major factors threatening public health, with morbidity and mortality rates at the forefront of the world. Clinical drawbacks, such as high toxicity and side effects of drug therapy, and easy recurrence after surgery affect its therapeutic effect. Gas signaling molecules are essential in maintaining biological homeostasis and physiological functions as specific chemical substances for biological information transfer. In recent years, the physiological regulatory functions of gas molecules in the cancer process have been gradually revealed and have shown broad application prospects in tumor therapy. In this paper, standard gas therapies are classified and introduced. Taking H2, CO2, NO, CO, H2S, and SO2 gases as examples, the research progress and application of gas therapies in malignant tumors are mainly introduced in terms of biological characteristics, anticancer mechanisms, and treatment strategies. Finally, the problems and prospects for developing gases as anticancer drugs are outlined.

Synthesis, antiproliferative activity, and molecular modeling of novel 4-methylcoumarin derivatives and/or nitric oxide donor hybrids

Two new 4-methylcoumarin derivatives (3a-f and 4a-f) were designed, synthesized, and evaluated for their cytotoxic activity. Different spectroscopic methods and elemental analyses confirmed all the synthesized derivatives' characterization. All the prepared compounds were biologically screened against four cancer cell lines (hepatocellular carcinoma HepG-2, colon cancer cell lines HCT-116, breast cancer cell lines MCF-7, and prostate cancer cell lines PC3). The in vitro antiproliferative activity of the target analogues 4b, 4c, 4f, 3b, and 3d against the MCF-7 cancer cell line was significant, with IC50 values of 3.98, 7.80, 10.94, 17.7, and 24.07 μM, respectively. Furthermore, the potent cytotoxic oxime derivative 4b was evaluated for cell cycle analysis showing a significant substantial disruption in cell cycle profile and cell cycle arrest at the S phase boundary with a time-dependent rise in a pre-G cell population, as well as a 22-fold increase in MCF-7 apoptosis compared to control cells. Accordingly, the Bax/Bcl-2 ratio, a critical ratio in controlling cell sensitivity to apoptosis, increased upon treatment with the oxime analog 4b. A docking investigation was conducted within the BcL-2 binding site to explore and anticipate the binding modes of the synthesized compounds. Thus, synthesizing these novel coumarin/nitric oxide hybrids may aid in developing promising antiproliferative agents.

Unraveling Metal-Ligand Bonding in an HNO-Evolving {FeNO}6 Complex with a Combined X-ray Spectroscopic Approach

Photolytic delivery of nitric oxide and nitroxide has substantial biomedical and phototherapeutic applications. Here, we utilized hard X-ray spectroscopic methods to identify key geometric and electronic structural features of two photolabile {FeNO}6 complexes where the compounds differ in the presence of a pendant thiol in [Fe(NO)(TMSPS2)(TMSPS2H)] and thioether in [Fe(NO)(TMSPS2)(TMSPS2CH3)] with the former complex being the only transition metal system to photolytically generate HNO. Fe Kβ XES identifies the photoreactant systems as essentially Fe(II)-NO+, while valence-to-core XES extracts a NO oxidation state of +0.5. Finally, the pre-edge of the Fe high-energy-resolution fluorescence detected (HERFD) XAS spectra is shown to be acutely sensitive to perturbation of the Fe-NO covalency enhanced by the 3d-4p orbital mixing dipole intensity contribution. Collectively, this X-ray spectroscopic approach enables future time-resolved insights in these systems and extensions to other challenging redox noninnocent {FeNO}x systems.

PI3K/Akt signalling pathway-associated long noncoding RNA signature predicts the prognosis of laryngeal cancer patients

The PI3K/Akt signalling pathway is associated with the occurrence and development of tumours and significantly affects the prognosis of patients. We established a predictive signature based on the PI3K/Akt pathway to predict the prognosis of patients. The RNA-seq and clinical data of laryngeal cancer patients were downloaded from The Cancer Genome Atlas (TCGA) database. Three lncRNAs (MNX1-AS1, LINC00330, LSAMP-AS1) were selected through univariate, multivariate Cox and log-rank test analysis to establish a prognostic signature. The patients were then divided into high-risk and low-risk groups based on their risk score. In the TCGA training set, the survival time of the high-risk group was shorter than that of the low-risk group (P < 0.01). Follicular helper T cells were lower in the high-risk group (P = 0.022), and CCR, inflammation promotion, parainflammation, and type I IFN immune function were suppressed. The results of the drug sensitivity analysis suggest that the high-risk group is sensitive to AKT inhibitors. The establishment of the signature was also verified based on the clinical data. Three lncRNAs can facilitate the migration, invasion, and vitality of cancer cells in vitro, and vice versa. Moreover, p-AKT (Ser473) and p-PI3K were highly activated in the cells overexpressing the abovementioned three lncRNAs. The PI3K/Akt signalling pathway-associated prognosis signature has a good predictive effect.

Monitoring Metabolic Changes in Response to Chemotherapies in Cancer with Raman Spectroscopy and Metabolomics

Resistance to clinical therapies remains a major barrier in cancer management. There is a critical need for rapid and highly sensitive diagnostic tools that enable early prediction of treatment response to allow accurate clinical decisions. Here, Raman spectroscopy was employed to monitor changes in key metabolites as early predictors of response in KRAS-mutant colorectal cancer (CRC) cells, HCT116, treated with chemotherapies. We show at the single cell level that HCT116 is resistant to cetuximab (CTX), the first-line treatment in CRC, but this resistance can be overcome with pre-sensitization of cells with oxaliplatin (OX). In combination treatment of CTX + OX, sequential delivery of OX followed by CTX rather than simultaneous administration of drugs was observed to be critical for effective therapy. Our results demonstrated that metabolic changes are well aligned to cellular mechanical changes where Young's modulus decreased after effective treatment, indicating that both changes in mechanical properties and metabolism in cells are likely responsible for cancer proliferation. Raman findings were verified with mass spectrometry (MS) metabolomics, and both platforms showed changes in lipids, nucleic acids, and amino acids as predictors of resistance/response. Finally, key metabolic pathways enriched were identified when cells are resistant to CTX but downregulated with effective treatment. This study highlights that drug-induced metabolic changes both at the single cell level (Raman) and ensemble level (MS) have the potential to identify mechanisms of response to clinical cancer therapies.

CS-NO suppresses inhibits glycolysis and gastric cancer progression through regulating YAP/TAZ signaling pathway

CONTEXT

Gastric cancer (GC) is a significant contributor to global mortality and is recognized for its elevated prevalence and fatality rates. Nitric Oxide (NO) plays a role in multiple aspects of cancer metastasis and progression. CS-NO is a polysaccharide-based biomaterial with NO-releasing properties that shows promising therapeutic potential. Nonetheless, the action mechanism of CS-NO in GC is still largely unclear.

METHODS

The present study employed various experimental techniques, including CCK-8 assay, colony formation assay, EdU staining, and transwell assays, to evaluate the proliferation, migration, and invasion of GC cells. Additionally, ELISA was utilized to measure glucose uptake, lactate production, and cellular ATP levels in GC cells. In vivo investigations on nude mice were conducted to validate the in vitro results.

OBJECTIVE

The present study aimed to examine the potential anti-tumor properties of CS-NO on GC through in vitro and in vivo investigations, while also exploring the underlying mechanisms involved.

RESULTS

Our data suggested that CS-NO might prevent GC cell invasion and migration. Decreased expressions of GLUT1, HK2, and LDHA further demonstrated that CS-NO significantly suppressed aerobic glycolysis in GC cells. The administration of CS-NO resulted in a significant reduction of YAP and TAZ levels in GC cells. Our data further show that CS-NO treatment could inhibit GC cancer growth in mice, consistent with the significant decrease in Ki67, GLUT1 and YAP expression levels.

DISCUSSION AND CONCLUSION

These findings could reveal the good effects of CS-NO therapy on inhibiting GC.

Nitric oxide synthase inhibitors as potential therapeutic agents for gliomas: A systematic review

INTRODUCTION

Gliomas represent the most prevalent form of brain tumors, among which glioblastomas are the most malignant subtype. Despite advances in comprehending their biology and treatment strategies, median survival remains disappointingly low. Inflammatory processes involving nitric oxide (NO), critically contribute to glioma formation. The inducible isoform of NO synthase (iNOS) is highly overexpressed in gliomas and has been linked to resistance against temozolomide (TMZ) treatment, neoplastic transformation, and modulation of immune response. While both in vitro and in vivo studies showed the potential of iNOS inhibitors as effective treatments for gliomas, no clinical trials on gliomas have been published. This review aims to summarize the available evidence regarding iNOS as a target for glioma treatment, focusing on clinically relevant data.

METHODS

Following PRISMA guidelines, we conducted a systematic review by searching PubMed/Medline, and Embase databases in May 2023. We included studies that investigated the impact of NOS inhibitors on glioma cells using L-NMMA, CM544, PBN, 1400W or l-NAME either alone or combined with TMZ. We extracted data on the NOS inhibitor used, subtype, study setting, animal model or cell lines employed, obtained results, and safety profile. Our inclusion criteria encompassed original articles in English or Spanish, studies with an untreated control group, and a primary outcome focused on the biological effects on glioma cells.

RESULTS

Out of 871 articles screened from the aforementioned databases, 37 reports were assessed for eligibility. After excluding studies that did not utilize glioma cells or address the designated outcome, 11 original articles satisfied the inclusion and exclusion criteria. Although no NOS inhibitor has been tested in a published clinical trial, three inhibitors have been evaluated using in vivo models of intracranial gliomas. l-NAME, 1400W, and CM544 were tested in vitro. Co-administration of l-NAME, or CM544 with TMZ showed superior results in vitro compared to individual agent testing.

CONCLUSION

Glioblastomas remain a challenging therapeutic target. iNOS inhibitors exhibit substantial potential as treatment options for oncologic lesions, and they have demonstrated a safe toxicity profile in humans for other pathological conditions. Research endeavors should be focused on investigating their potential effects on brain tumors.

Bj-PRO-10c, as an allosteric regulator of argininosuccinate synthase, is a potential therapy for neuroblastoma metastasis

Cancer is a global public health issue. Neuroblastoma (NB) originates from any tissue of the sympathetic nervous system, and the most affected site is the abdomen. The adrenal gland is the primary site in 38% of cases. Approximately 50% of patients have metastatic disease at diagnosis, and bone marrow is often affected. Metastatic disease is characterized by the spreading of cancer cells that are frequently resistant to chemotherapy and radiotherapy from the primary tumor to other specific parts of the body and is responsible for 90% of cancer-related deaths. Increasing evidence has indicated that nitric oxide (NO) signaling is implicated in the pathophysiology of many types of cancer, particularly in tumorigenesis and cancer progression. However, the effect of NO on metastasis cannot be easily classified as prometastatic or antimetastatic. An understanding at the molecular level of the role of NO in cancer will have profound therapeutic implications for the diagnosis and treatment of disease. Here, the proline-rich decapeptide isolated from Bothrops jararaca venom (Bj-PRO-10c) that enhances and sustains the generation of NO was used to unravel the role of metabolic NO in steps of metastasis. Bj-PRO-10c showed an antimetastatic effect, mainly by interfering with actin cytoskeleton rearrangement, controlling cell proliferation, and decreasing the seeding efficiency of NB in metastatic niches. Therefore, we proposed that an approach for controlled NO induction with the right molecular strategies can hopefully inhibit metastasis and increase the lifespan of NB patients.

Inducible nitric oxide synthase (iNOS)-activated Cxcr2 signaling in myeloid cells promotes TGFβ-dependent squamous cell carcinoma lung metastasis

Transforming growth factor beta (TGFβ) activity is linked to metastasis in many cancer types, but whether TGFβ activity is necessary for squamous cell carcinoma (SCC) lung metastasis has not been studied. Here we used a lung metastatic SCC model derived from keratin 15 (K15). KrasG12D.Smad4-/- SCC and human SCC specimens to identify metastasis drivers and test therapeutic interventions. We demonstrated that a TGFβ receptor (TGFβR) inhibitor reduced lung metastasis in mouse SCC correlating with reduced CD11b+/Ly6G+ myeloid cells positive for inducible nitric oxide synthase (iNOS). Further, TGFβ activity and iNOS were higher in primary human oral SCCs with metastasis than SCCs without metastasis. Consistently, either depleting myeloid cells with anti-Gr1 antibody or inhibiting iNOS with L-N6-(1-iminoethyl)-l-lysine (L-NIL) reduced SCC lung metastasis. L-NIL treated tumor-bearing mice exhibited reductions in tumor-infiltrating myeloid cells and in plasma Cxcl5 levels, and attenuated primary tumor growth with increased apoptosis and decreased proliferation. Blocking Cxcl5 with an antagonist of its receptor Cxcr2, SB225002, also reduced SCC lung metastasis.

N-Nitrosation Based Fluorescence Turn-On Nitric Oxide Probe: Kinetic and Cell Imaging Studies

Nitric oxide (NO) is a ubiquitous messenger molecule playing a key role in various physiological and pathological processes. However, producing a selective turn-on fluorescence response to NO is a challenging task due to (a) the very short half-life of NO (typically in the range of 0.1-10 s) in the biological milieu and (b) false positive responses to reactive carbonyl species (RCS) (e.g., dehydroascorbic acid and methylglyoxal etc.) and some other reactive oxygen/nitrogen species (ROS/RNS), especially with o-phenylenediamine (OPD) based fluorosensors. To avoid these limitations, NO sensors should be designed in such a way that they react spontaneously with NO to give turn-on response within the time frame of t1/2 (typically in the range of 0.1-10 s) of NO and λem in the visible wavelength along with good cell permeability to achieve biocompatibility. With these views in mind, a N-nitrosation based fluorescent sensor, NDAQ, has been developed that is highly selective to NO with ∼27-fold fluorescence enhancement at λem = 542 nm with high sensitivity (LOD = 7 ± 0.4 nM) and shorter response time, eliminating the interference of other reactive species (RCS/ROS/RNS). Furthermore, all the photophysical studies with NDAQ have been performed in 98% aqueous medium at physiological pH, indicating its good stability under physiological conditions. The kinetic assay illustrates the second-order dependency with respect to NO concentration and first-order dependency with respect to NDAQ concentration. The biological studies reveal the successful application of the probe to track both endogenous and exogenous NO in living organisms.

Red-Light-Photosensitized NO Release and Its Monitoring in Cancer Cells with Biodegradable Polymeric Nanoparticles

The role of nitric oxide (NO) as an "unconventional" therapeutic and the strict dependence of biological effects on its concentration require the generation of NO with precise spatiotemporal control. The development of precursors and strategies to activate NO release by excitation in the so-called "therapeutic window" with highly biocompatible and tissue-penetrating red light is desirable and challenging. Herein, we demonstrate that one-photon red-light excitation of Verteporfin, a clinically approved photosensitizer (PS) for photodynamic therapy, activates NO release, in a catalytic fashion, from an otherwise blue-light activatable NO photodonor (NOPD) with an improvement of about 300 nm toward longer and more biocompatible wavelengths. Steady-state and time-resolved spectroscopic and photochemical studies combined with theoretical calculations account for an NO photorelease photosensitized by the lowest triplet state of the PS. In view of biological applications, the water-insoluble PS and NOPD have been co-entrapped within water-dispersible, biodegradable polymeric nanoparticles (NPs) of mPEG-b-PCL (about 84 nm in diameter), where the red-light activation of NO release takes place even more effectively than in an organic solvent solution and almost independently by the presence of oxygen. Moreover, the ideal spectroscopic prerequisites and the restricted environment of the NPs permit the green-fluorescent co-product formed concomitantly to NO photorelease to communicate with the PS via Förster resonance energy transfer. This leads to an enhancement of the typical red emission of the PS offering the possibility of a double color optical reporter useful for the real-time monitoring of the NO release through fluorescence techniques. The suitability of this strategy applied to the polymeric NPs as potential nanotherapeutics was evaluated through biological tests performed by using HepG2 hepatocarcinoma and A375 melanoma cancer cell lines. Fluorescence investigation in cells and cell viability experiments demonstrates the occurrence of the NO release under one-photon red-light illumination also in the biological environment. This confirms that the adopted strategy provides a valuable tool for generating NO from an already available NOPD, otherwise activatable with the poorly biocompatible blue light, without requiring any chemical modification and the use of sophisticated irradiation sources.

Theoretical characterization of two-photon fluorescent probes for nitric oxide detection: sensing mechanism, photophysical properties and protonation effects

Nitric oxide (NO) is an important signal molecule in biological systems and is correlated with many physiological processes and pathological diseases. To date, numerous fluorescent probes based on o-diamino aromatics have been designed and synthesized for NO detection utilizing the principle of photoinduced electron transfer (PET). However, the underlying PET mechanism has rarely been validated, and a systematic computational study on the photophysical properties is urgently desired. In this study, we used a theoretical protocol to comparatively investigate the sensing mechanism, photophysical properties and protonation effects of two emblematic probes NINO and PYSNO in aqueous solution, which combines a polarizable continuum model (PCM), time-dependent density functional theory (TD-DFT) and thermal vibration correlation function formalism (TVCF). Our findings reveal that the weak emission of NINO is due to activated PET with negative driving energy and blocked fluorescence with significant charge separation. In contrast, the poor luminescence of PYSNO is caused by the facilitated non-radiative dissipation, even though the fluorescence emission remains unobstructed. Although NINO has been successfully used in two-photon microscopy for detecting NO, we suggest that PYSNO possesses a superior two-photon absorption (TPA) cross section in the near-infrared region. The protonation effects suggest that both probes can function effectively in practical acidic lysosomal environments. Our study opens a new avenue for understanding the mechanism and predicting the properties of two-photon fluorescent probes for NO detection, thus aiding the rational design of efficient fluorescent sensors.

Periprostatic adipose tissue (PPAT) supernatant from obese mice releases anticontractile substances and increases human prostate epithelial cell proliferation: the role of nitric oxide and adenosine

Background: The prostate gland is surrounded by periprostatic adipose tissue (PPAT) that can release mediators that interfere in prostate function. In this study, we examined the effect of periprostatic adipose tissue supernatant obtained from obese mice on prostate reactivity in vitro and on the viability of human prostatic epithelial cell lines. Methods: Male C57BL/6 mice were fed a standard or high-fat diet after which PPAT was isolated, incubated in Krebs-Henseleit solution for 30 min (without prostate) or 60 min (with prostate), and the supernatant was then collected and screened for biological activity. Total nitrate and nitrite (NOx^-) and adenosine were quantified, and the supernatant was then collected and screened for biological activity. NOx^- and adenosine were quantified. Concentration-response curves to phenylephrine (PE) were obtained in prostatic tissue from lean and obese mice incubated with or without periprostatic adipose tissue. In some experiments, periprostatic adipose tissue was co-incubated with inhibitors of the nitric oxide (NO)-cyclic guanosine monophosphate pathway (L-NAME, 1400W, ODQ), adenylate cyclase (SQ22536) or with adenosine A_2A (ZM241385), and A_2B (MRS1754) receptor antagonists. PNT1-A (normal) and BPH-1 (hyperplasic) human epithelial cells were cultured and incubated with supernatant from periprostatic adipose tissue for 24, 48, or 72 h in the absence or presence of these inhibitors/antagonists, after which cell viability and proliferation were assessed. Results: The levels of NOx^- and adenosine were significantly higher in the periprostatic adipose tissue supernatant (30 min, without prostate) when compared to the vehicle. A trend toward an increase in the levels of NOX was observed after 60 min. PPAT supernatant from obese mice significantly reduced the PE-induced contractions only in prostate from obese mice. The co-incubation of periprostatic adipose tissue with L-NAME, 1400W, ODQ, or ZM241385 attenuated the anticontractile activity of the periprostatic adipose tissue supernatant. Incubation with the supernatant of periprostatic adipose tissue from obese mice significantly increased the viability of PNT1-A cells and attenuated expression of the apoptosis marker protein caspase-3 when compared to cells incubated with periprostatic adipose tissue from lean mice. Hyperplastic cells (BPH-1) incubated with periprostatic adipose tissue from obese mice showed greater proliferation after 24 h, 48 h, and 72 h compared to cells incubated with culture medium alone. BPH-1 cell proliferation in the presence of PPAT supernatant was attenuated by NO-signaling pathway inhibitors and by adenosine receptor antagonists after 72 h. Conclusion: NO and adenosine are involved in the anticontractile and pro-proliferative activities of periprostatic adipose tissue supernatant from obese mice. More studies are needed to determine whether the blockade of NO and/or adenosine derived from periprostatic adipose tissue can improve prostate function.

The Role of Hyperthermia in Potentiation of Anti-Angiogenic Effect of Cisplatin and Resveratrol in Mice Bearing Solid Form of Ehrlich Ascites Tumour

The aim of this study was to investigate the therapeutic potential of resveratrol in combination with cisplatin on the inhibition of tumour angiogenesis, growth, and macrophage polarization in mice bearing the solid form of an Ehrlich ascites tumour (EAT) that were exposed to whole-body hyperthermia treatment. In addition, we investigated whether a multimodal approach with hyperthermia and resveratrol could abolish cisplatin resistance in tumour cells through the modulation of histone deacetylase (HDAC) activity and levels of heat shock proteins (HSP70/HSP90) and contribute to the direct toxicity of cisplatin on tumour cells. The tumour was induced by injecting 1 × 10⁶ EAT cells subcutaneously (sc) into the thighs of Balb/c mice. The mice were treated with resveratrol per os for five consecutive days beginning on day 2 after tumour injection and/or by injecting cisplatin intraperitoneally (ip) at a dose of 2.5 mg/kg on days 10 and 12 and at a dose of 5 mg/kg on day 15. Immediately thereafter, the mice were exposed to systemic hyperthermia for 15 min at a temperature of 41 °C. The obtained results showed that the administration of resveratrol did not significantly contribute to the antitumour effect of cisplatin and hyperthermia, but it partially contributed to the immunomodulatory effect and to the reduction of cisplatin toxicity and to a slight increase in animal survival. This treatment schedule did not affect microvessel density, but it inhibited tumour growth and modulated macrophage polarization to the M1 phenotype. Furthermore, it abolished the resistance of tumour cells to cisplatin by modulating HDAC activity and the concentration of HSP70 and HSP90 chaperones, contributing to the increased lifespan of mice. However, the precise mechanism of the interaction between resveratrol, cisplatin, and hyperthermia needs to be investigated further.

"Iridium Signature" Mass Spectrometric Probes: New Tools Integrated in a Liquid Chromatography-Mass Spectrometry Workflow for Routine Profiling of Nitric Oxide and Metabolic Fingerprints in Cells

Nitric oxide (NO) is a highly reactive signaling molecule involved in diverse biological processes. Simultaneous profiling of NO and associated metabolic fingerprints in a single assay allows more accurate assessments of cell states and offers the possibility to better understand its exact biological roles. Herein, a multiplexing LC-MS workflow was established for simultaneous detection of intracellular NO and various metabolites based on a novel "iridium signature" mass spectrometric probe (Ir-MSP841). This Ir-MSP841 can convert highly liable NO to a stable permanently charged triazole product (Ir-TP852), enabling direct MS detection of NO. This ^191/193Ir-signature mass spectrometric probe-based approach is endowed with overwhelming advantages of interference-free, high quantitative accuracy, and great sensitivity (limit of detection down to 0.14 nM). It also reveals good linearity over a wide concentration range 12.5-500 nM and has been successfully employed for exploring the release behaviors of three representative NO donors in cells. Meanwhile, metabolic profiling results reveal that varying the concentrations of NO has distinct effects on various cellular metabolites. This study provides a robust, sensitive, and versatile method for simultaneous detection of NO and numerous metabolites in a single LC-MS run and expands its applications in biomedical research.

The strange Microenvironment of Glioblastoma

Glioblastoma (GB) is the most common and aggressive primary brain tumor, with poor patient survival and lack of effective therapies. Late advances trying to decipher the composition of the GB tumor microenvironment (TME) emphasized its role in tumor progression and potentialized it as a therapeutic target. Many components participate critically to tumor development and expansion such as blood vessels, immune cells or components of the nervous system. Dysmorphic tumor vasculature brings challenges to optimal delivery of cytotoxic agents currently used in clinics. Also, massive infiltration of immunosuppressive myeloid cells and limited recruitment of T cells limits the success of conventional immunotherapies. Neuronal input seems also be required for tumor expansion. In this review, we provide a comprehensive report of vascular and immune component of the GB TME and their cross talk during GB progression.

Synthesis, cytotoxicity, and biomacromolecule binding: Three isomers of nitrosylruthenium complexes with bidentate bioactive molecules as co-ligands

Three isomeric nitrosylruthenium complexes [RuNO(Qn)(PZA)Cl] (P1, P2, and P3) with bioactive small molecules 8-hydroxyquinoline (Qn) and pyrazinamide (PZA) as co-ligands were synthesized, and their crystal structures were determined using X-ray diffraction technique. The cellular toxicity of the isomeric complexes was compared to understand the effects of the geometries on the biological activity of the complexes. Both the complexes and the human serum albumin (HSA) complex adducts affected the extent of proliferation of HeLa cells (IC₅₀: 0.77-1.45 μM). P2 showed prominent activity-induced cell apoptosis and arrested cell cycles at the G1 phase. The binding constants (K_b) of the complex with calf thymus DNA (CT-DNA) and HSA were quantitatively evaluated using fluorescence spectroscopy in the range of 0.17-1.56 × 10⁴ M^-1 and 0.88-3.21 × 10⁵ M^-1, respectively. The average binding site (n) number was close to 1. Moreover, the structure of HSA and the P2 complex adduct solved at the resolution of 2.48 Å revealed that one PZA-coordinated nitrosylruthenium complex bound at the subdomain I of HSA via a noncoordinative bond. HSA could serve as a potential nano-delivery system. This study provides a framework for the rational design of metal-based drugs.