Upsides and downsides of reactive oxygen species for cancer: the roles of reactive oxygen species in tumorigenesis, prevention, and therapy

The activity of pyrazolo[4,3-e][1,2,4]triazine and pyrazolo[4,3-e]tetrazolo[1,5-b][1,2,4]triazine sulphonamide derivatives in monolayer and spheroid breast cancer cell cultures

In the last decade, an increasing interest in compounds containing pyrazolo[4,3-e][1,2,4]triazine moiety is observed. Therefore, the aim of the research was to synthesise a novel sulphonyl pyrazolo[4,3-e][1,2,4]triazines (2a, 2b) and pyrazolo[4,3-e]tetrazolo[1,5-b][1,2,4]triazine sulphonamide derivatives (3a, 3b) to assess their anticancer activity. The MTT assay showed that 2a, 2b, 3a, 3b have stronger cytotoxic activity than cisplatin in both breast cancer cells (MCF-7 and MDA-MB-231) and exhibited weaker effect on normal breast cells (MCF-10A). The obtained results showed that the most active compound 3b increased apoptosis via caspase 9, caspase 8, and caspase 3/7. It is worth to note that compound 3b suppressed NF-κB expression and promoted p53, Bax, and ROS which play important role in activation of apoptosis. Moreover, our results confirmed that compound 3b triggers autophagy through increased formation of autophagosomes, expression of beclin-1 and mTOR inhibition. Thus, our study defines a possible mechanism underlying 3b-induced anti-cancer activity against breast cancer cell lines.

The molecular mechanism of action for the potent antitumor component extracted using supercritical fluid extraction from Croton crassifolius root

ETHNOPHARMACOLOGICAL RELEVANCE

The root of Croton crassifolius has been used as a traditional Chinese medicine (TCM), called Radix Croton Crassifolius, and commonly known as "Ji Gu Xiang" in Chinese. Its medicinal value has been recorded in several medical books or handbooks, such as "Sheng Cao Yao Xing Bei Yao", "Ben Cao Qiu Yuan" and "Zhong Hua Ben Cao". It has been traditional employed for treating sore throat, stomach-ache, rheumatism and cancer.

AIM OF THE STUDY

At present, there are limited studies on the evaluation of low-polarity extracts of roots in C. crassifolius. Consequently, the aim of this study was to evaluate the antitumor effect of the low-polarity extract of C. crassifolius root.

MATERIALS AND METHODS

Extracts were obtained by supercritical fluid extraction. The extracts were tested for antitumor effects in vitro on several cancer cell lines. A CCK-8 kit was used for further analysis of cell viability. A flow cytometer and propidium iodide staining were used to evaluate the cell cycle and apoptosis. Hoechst staining, JC-1 staining and the fluorescence probe DCFH-DA were used to evaluate apoptotic cells. Molecular mechanisms of action were analyzed by quantitative RT‒PCR and Western blotting. Immunohistochemistry was used for the evaluation of xenograft tumors in male BALB/c mice. Finally, molecular docking was employed to predict the bond between the desired bioactive compound and molecular targets.

RESULTS

Eleven diterpenoids were isolated from low-polarity C. crassifolius root extracts. Among the compounds, chettaphanin II showed the strongest activity (IC50 = 8.58 μM) against A549 cells. Evaluation of cell viability and the cell cycle showed that Chettaphanin II reduced A549 cell proliferation and induced G2/M-phase arrest. Chttaphanin II significantly induced apoptosis in A549 cells, which was related to the level of apoptosis-related proteins. The growth of tumor tissue was significantly inhibited by chettaphanin II in experiments performed on naked mice. The antitumor mechanism of chettaphanin II is that it can obstruct the mTOR/PI3K/Akt signaling pathway in A549 cells. Molecular docking established that chettaphanin II could bind to the active sites of Bcl-2 and Bax.

CONCLUSIONS

Taken together, the natural diterpenoid chettaphanin II was identified as the major antitumor active component, and its potential for developing anticancer therapies was demonstrated for the first time by antiproliferation evaluation in vitro and in vivo.

Deciphering the Molecular Mechanisms behind Drug Resistance in Ovarian Cancer to Unlock Efficient Treatment Options

Ovarian cancer is a highly lethal form of gynecological cancer. This disease often goes undetected until advanced stages, resulting in high morbidity and mortality rates. Unfortunately, many patients experience relapse and succumb to the disease due to the emergence of drug resistance that significantly limits the effectiveness of currently available oncological treatments. Here, we discuss the molecular mechanisms responsible for resistance to carboplatin, paclitaxel, polyadenosine diphosphate ribose polymerase inhibitors, and bevacizumab in ovarian cancer. We present a detailed analysis of the most extensively investigated resistance mechanisms, including drug inactivation, drug target alterations, enhanced drug efflux pumps, increased DNA damage repair capacity, and reduced drug absorption/accumulation. The in-depth understanding of the molecular mechanisms associated with drug resistance is crucial to unveil new biomarkers capable of predicting and monitoring the kinetics during disease progression and discovering new therapeutic targets.

PI3K/AKT Signaling Pathway Mediated Autophagy in Oral Carcinoma - A Comprehensive Review

Oral cancer is the most heterogeneous cancer at clinical and histological levels. PI3K/AKT/mTOR pathway was identified as one of the most commonly modulated signals in oral cancer, which regulates major cellular and metabolic activity of the cell. Thus, various proteins of PI3K/AKT/mTOR pathway were used as therapeutic targets for oral cancer, to design more specific drugs with less off-target toxicity. This review sheds light on the regulation of PI3K/AKT/mTOR, and its role in controlling autophagy and associated apoptosis during the progression and metastasis of oral squamous type of malignancy (OSCC). In addition, we reviewed in detail the upstream activators and the downstream effectors of PI3K/AKT/mTOR signaling as potential therapeutic targets for oral cancer treatment.

Conquering chemoresistance in pancreatic cancer: Exploring novel drug therapies and delivery approaches amidst desmoplasia and hypoxia

Pancreatic cancer poses a significant challenge within the field of oncology due to its aggressive behaviour, limited treatment choices, and unfavourable outlook. With a mere 10% survival rate at the 5-year mark, finding effective interventions becomes even more pressing. The intricate relationship between desmoplasia and hypoxia in the tumor microenvironment further complicates matters by promoting resistance to chemotherapy and impeding treatment efficacy. The dense extracellular matrix and cancer-associated fibroblasts characteristic of desmoplasia create a physical and biochemical barrier that impedes drug penetration and fosters an immunosuppressive milieu. Concurrently, hypoxia nurtures aggressive tumor behaviour and resistance to conventional therapies. a comprehensive exploration of emerging medications and innovative drug delivery approaches. Notably, advancements in nanoparticle-based delivery systems, local drug delivery implants, and oxygen-carrying strategies are highlighted for their potential to enhance drug accessibility and therapeutic outcomes. The integration of these strategies with traditional chemotherapies and targeted agents reveals the potential for synergistic effects that amplify treatment responses. These emerging interventions can mitigate desmoplasia and hypoxia-induced barriers, leading to improved drug delivery, treatment efficacy, and patient outcomes in pancreatic cancer. This review article delves into the dynamic landscape of emerging anticancer medications and innovative drug delivery strategies poised to overcome the challenges imposed by desmoplasia and hypoxia in the treatment of pancreatic cancer.

Phytocompounds targeting epigenetic modulations: an assessment in cancer

For centuries, plants have been serving as sources of potential therapeutic agents. In recent years, there has been a growing interest in investigating the effects of plant-derived compounds on epigenetic processes, a novel and captivating Frontier in the field of epigenetics research. Epigenetic changes encompass modifications to DNA, histones, and microRNAs that can influence gene expression. Aberrant epigenetic changes can perturb key cellular processes, including cell cycle control, intercellular communication, DNA repair, inflammation, stress response, and apoptosis. Such disruptions can contribute to cancer development by altering the expression of genes involved in tumorigenesis. However, these modifications are reversible, offering a unique avenue for therapeutic intervention. Plant secondary compounds, including terpenes, phenolics, terpenoids, and sulfur-containing compounds are widely found in grains, vegetables, spices, fruits, and medicinal plants. Numerous plant-derived compounds have demonstrated the potential to target these abnormal epigenetic modifications, including apigenin (histone acetylation), berberine (DNA methylation), curcumin (histone acetylation and epi-miRs), genistein (histone acetylation and DNA methylation), lycopene (epi-miRs), quercetin (DNA methylation and epi-miRs), etc. This comprehensive review highlights these abnormal epigenetic alterations and discusses the promising efficacy of plant-derived compounds in mitigating these deleterious epigenetic signatures in human cancer. Furthermore, it addresses ongoing clinical investigations to evaluate the therapeutic potential of these phytocompounds in cancer treatment, along with their limitations and challenges.

The role of oxygen tension in cell fate and regenerative medicine: implications of hypoxia/hyperoxia and free radicals

Oxygen pressure plays an integral role in regulating various aspects of cellular biology. Cell metabolism, proliferation, morphology, senescence, metastasis, and angiogenesis are some instances that are affected by different tensions of oxygen. Hyperoxia or high oxygen concentration, enforces the production of reactive oxygen species (ROS) that disturbs physiological homeostasis, and consequently, in the absence of antioxidants, cells and tissues are directed to an undesired fate. On the other side, hypoxia or low oxygen concentration, impacts cell metabolism and fate strongly through inducing changes in the expression level of specific genes. Thus, understanding the precise mechanism and the extent of the implication of oxygen tension and ROS in biological events is crucial to maintaining the desired cell and tissue function for application in regenerative medicine strategies. Herein, a comprehensive literature review has been performed to find out the impacts of oxygen tensions on the various behaviors of cells or tissues.

IRF3 function and immunological gaps in sepsis

Lipopolysaccharide (LPS) induces potent cell activation via Toll-like receptor 4/myeloid differentiation protein 2 (TLR4/MD-2), often leading to septic death and cytokine storm. TLR4 signaling is diverted to the classical acute innate immune, inflammation-driving pathway in conjunction with the classical NF-κB pivot of MyD88, leading to epigenetic linkage shifts in nuclear pro-inflammatory transcription and chromatin structure-function; in addition, TLR4 signaling to the TIR domain-containing adapter-induced IFN-β (TRIF) apparatus and to nuclear pivots that signal the association of interferons alpha and beta (IFN-α and IFN-β) with acute inflammation, often coupled with oxidants favor inhibition or resistance to tissue injury. Although the immune response to LPS, which causes sepsis, has been clarified in this manner, there are still many current gaps in sepsis immunology to reduce mortality. Recently, selective agonists and inhibitors of LPS signals have been reported, and there are scattered reports on LPS tolerance and control of sepsis development. In particular, IRF3 signaling has been reported to be involved not only in sepsis but also in increased pathogen clearance associated with changes in the gut microbiota. Here, we summarize the LPS recognition system, main findings related to the IRF3, and finally immunological gaps in sepsis.

Redox Regulation of PTEN by Reactive Oxygen Species: Its Role in Physiological Processes

Phosphatase and tensin homolog (PTEN) is a tumor suppressor due to its ability to regulate cell survival, growth, and proliferation by downregulating the PI3K/AKT signaling pathway. In addition, PTEN plays an essential role in other physiological events associated with cell growth demands, such as ischemia-reperfusion, nerve injury, and immune responsiveness. Therefore, recently, PTEN inhibition has emerged as a potential therapeutic intervention in these situations. Increasing evidence demonstrates that reactive oxygen species (ROS), especially hydrogen peroxide (H2O2), are produced and required for the signaling in many important cellular processes under such physiological conditions. ROS have been shown to oxidize PTEN at the cysteine residue of its active site, consequently inhibiting its function. Herein, we provide an overview of studies that highlight the role of the oxidative inhibition of PTEN in physiological processes.

Health position paper and redox perspectives - Disease burden by transportation noise

Transportation noise is a ubiquitous urban exposure. In 2018, the World Health Organization concluded that chronic exposure to road traffic noise is a risk factor for ischemic heart disease. In contrast, they concluded that the quality of evidence for a link to other diseases was very low to moderate. Since then, several studies on the impact of noise on various diseases have been published. Also, studies investigating the mechanistic pathways underlying noise-induced health effects are emerging. We review the current evidence regarding effects of noise on health and the related disease-mechanisms. Several high-quality cohort studies consistently found road traffic noise to be associated with a higher risk of ischemic heart disease, heart failure, diabetes, and all-cause mortality. Furthermore, recent studies have indicated that road traffic and railway noise may increase the risk of diseases not commonly investigated in an environmental noise context, including breast cancer, dementia, and tinnitus. The harmful effects of noise are related to activation of a physiological stress response and nighttime sleep disturbance. Oxidative stress and inflammation downstream of stress hormone signaling and dysregulated circadian rhythms are identified as major disease-relevant pathomechanistic drivers. We discuss the role of reactive oxygen species and present results from antioxidant interventions. Lastly, we provide an overview of oxidative stress markers and adverse redox processes reported for noise-exposed animals and humans. This position paper summarizes all available epidemiological, clinical, and preclinical evidence of transportation noise as an important environmental risk factor for public health and discusses its implications on the population level.

Cold atmospheric plasma (CAP) treatment increased reactive oxygen and nitrogen species (RONS) levels in tumor samples obtained from patients with low-grade glioma

Low-grade gliomas (LGGs) are a heterogeneous group of tumors with an average 10-year survival rate of 40%-55%. Current treatment options include chemotherapy, radiotherapy, and gross total resection (GTR) of the tumor. The extent of resection (EOR) plays an important role in improving surgical outcomes. However, the major obstacle in treating low-grade gliomas is their diffused nature and the presence of residual cancer cells at the tumor margins post resection. Cold Atmospheric Plasma (CAP) has shown to be effective in targeted killing of tumor cells in various glioma cell lines without affecting non-tumor cells through Reactive Oxygen and Nitrogen Species (RONS). However, no study on the effectiveness of CAP has been carried out in LGG tissues till date. In this study, we applied helium-based CAP on tumor tissues resected from LGG patients. Our results show that CAP is effective in promoting RONS accumulation in LGG tissues when CAP jet parameters are set at 4 kV voltage, 5 min treatment time and 3 lpm gas flow rate. We also observed that CAP jet is more effective in thinner slice preparations of tumor as compared to thick tumor samples. Our results indicate that CAP could prove to be an effective adjunct therapy in glioma surgery to target residual cancer cells to improve surgical outcome of patients with low-grade glioma.

Preclinical evaluation of L-fucoside from lapachol-loaded nanoemulsion as a strategy to breast cancer treatment

Breast cancer prevails as the most common cancer in women, underscoring an urgent need for more effective therapies. This study explores the potential of our newly developed nanoemulsion containing a novel fucoside derivative of lapachol (NE-F-LapA) as an intravenous treatment strategy. We sought to overcome the solubility issues associated with fucoside with this improved drug delivery strategy that enhances tumor delivery and mitigates other dose-limiting toxicities. Nanoemulsion was prepared and characterized by DLS, zeta potential, encapsulation efficiency, and storage stability. Cytotoxicity against breast cancer cell lines (4T1 and MDA-MB-231) and non-tumor human fibroblasts (NTHF) were evaluated. In vivo assays included antitumoral activity performance and acute systemic toxicity in mice models. NE-F-LapA was synthesized and optimized to 200 nm size, - 20 mV zeta potential, and near-complete (>98%) drug encapsulation. Stability exceeded 6 months, and biological fluid exposure maintained suitable properties for administration. In vitro, NE-F-LapA showed high toxicity (3 µM) against 4T1 and MDA-MB-231, enhanced five times the breast cancer cell uptake and three times the selectivity when compared to normal cells. Systemic toxicity assessment in mice revealed no concerning hematological or biochemical changes. Finally, in a 4T1 breast tumor model, NE-F-LapA significantly inhibited growth by 50% of the subcutaneous 4T1 tumor and reduced lung metastases 5-fold versus control. Overall, tailored nanoemulsification of the lapachol derivative enabled effective intravenous administration and improved efficacy over the free drug, indicating promise for enhanced breast cancer therapy pending further optimization.

Redox and metabolic reprogramming in breast cancer and cancer-associated adipose tissue

Redox and metabolic processes are tightly coupled in both physiological and pathological conditions. In cancer, their integration occurs at multiple levels and is characterized by synchronized reprogramming both in the tumor tissue and its specific but heterogeneous microenvironment. In breast cancer, the principal microenvironment is the cancer-associated adipose tissue (CAAT). Understanding how the redox-metabolic reprogramming becomes coordinated in human breast cancer is imperative both for cancer prevention and for the establishment of new therapeutic approaches. This review aims to provide an overview of the current knowledge of the redox profiles and regulation of intermediary metabolism in breast cancer while considering the tumor and CAAT of breast cancer as a unique Warburg's pseudo-organ. As cancer is now recognized as a systemic metabolic disease, we have paid particular attention to the cell-specific redox-metabolic reprogramming and the roles of estrogen receptors and circadian rhythms, as well as their crosstalk in the development, growth, progression, and prognosis of breast cancer.

A Zero-Valent Sulfur Transporter Helps Podophyllotoxin Uptake into Bacterial Cells in the Presence of CTAB

Podophyllotoxin (PTOX) is naturally produced by the plant Podophyllum species. Some of its derivatives are anticancer drugs, which are produced mainly by using chemical semi-synthesis methods. Recombinant bacteria have great potential in large-scale production of the derivatives of PTOX. In addition to introducing the correct enzymes, the transportation of PTOX into the cells is an important factor, which limits its modification in the bacteria. Here, we improved the cellular uptake of PTOX into Escherichia coli with the help of the zero-valent sulfur transporter YedE1E2 in the presence of cetyltrimethylammonium bromide (CTAB). CTAB promoted the uptake of PTOX, but induced the production of reactive oxygen species. A protein complex (YedE1E2) of YedE1 and YedE2 enabled E. coli cells to resist CTAB by reducing reactive oxygen species, and YedE1E2 was a hypothetical transporter. Further investigation showed that YedE1E2 facilitated the uptake of extracellular zero-valent sulfur across the cytoplasmic membrane and the formation of glutathione persulfide (GSSH) inside the cells. The increased GSSH minimized oxidative stress. Our results indicate that YedE1E2 is a zero-valent sulfur transporter and it also facilitates CTAB-assisted uptake of PTOX by recombinant bacteria.

The pathogenesis and potential therapeutic targets in sepsis

Sepsis is defined as "a life-threatening organ dysfunction caused by dysregulated host systemic inflammatory and immune response to infection." At present, sepsis continues to pose a grave healthcare concern worldwide. Despite the use of supportive measures in treating traditional sepsis, such as intravenous fluids, vasoactive substances, and oxygen plus antibiotics to eradicate harmful pathogens, there is an ongoing increase in both the morbidity and mortality associated with sepsis during clinical interventions. Therefore, it is urgent to design specific pharmacologic agents for the treatment of sepsis and convert them into a novel targeted treatment strategy. Herein, we provide an overview of the molecular mechanisms that may be involved in sepsis, such as the inflammatory response, immune dysfunction, complement deactivation, mitochondrial damage, and endoplasmic reticulum stress. Additionally, we highlight important targets involved in sepsis-related regulatory mechanisms, including GSDMD, HMGB1, STING, and SQSTM1, among others. We summarize the latest advancements in potential therapeutic drugs that specifically target these signaling pathways and paramount targets, covering both preclinical studies and clinical trials. In addition, this review provides a detailed description of the crosstalk and function between signaling pathways and vital targets, which provides more opportunities for the clinical development of new treatments for sepsis.

The master antioxidant defense is activated during EBV latent infection

IMPORTANCE

To our knowledge, this is the first report delineating the activation of the master antioxidant defense during EBV latency. We show that EBV-triggered reactive oxygen species production activates the Keap1-NRF2 pathway in EBV-transformed cells, and LMP1 plays a major role in this event, and the stress-related kinase TBK1 is required for NRF2 activation. Moreover, we show that the Keap1-NRF2 pathway is important for cell proliferation and EBV latency maintenance. Our findings disclose how EBV controls the balance between oxidative stress and antioxidant defense, which greatly improve our understanding of EBV latency and pathogenesis and may be leveraged to opportunities toward the improvement of therapeutic outcomes in EBV-associated diseases.

A novel flavonol glycoside and six derivatives of quercetin and kaempferol from Clematis flammula with antioxidant and anticancer potentials

Clematis flammula leaves are traditionally used in Algeria to treat rheumatoid arthritis. Our aim was to identify the main compounds in this plant in order to characterize its antioxidant and anticancer activities. A new flavonol compound, kaempferol 3-O-[(6-O- caffeoyl)- glucosyl(1 → 2)]-(6-Ocaffeoyl) glucoside-7-O-rhamnoside (6) along with six known flavonol molecules were isolated from an ethanolic extract of Clematis flammula leaves. The chemical structures of these flavonols were elucidated using NMR and high resolution-MS spectroscopies. Antioxidant activities of the extract were revealed through its elimination of superoxide radical (O2.-) produced enzymatically (49.7 ± 1.52% at 50 μg/ml) and non-enzymatically (34 ± 1.2% at 100 μg/ml), probably related to its inhibition of the xanthine oxidase form of the xanthine oxidoreductase (XOR) enzyme (25.05 ± 2.33 μg/mL at 100 μg/mL), but mostly to that of the NADH oxidase form of the enzyme (69.16 ± 4.0%). Cytotoxicity tests of the extract on human hepatoma cell line HepG2 and ovarian cancer cell lines A2780 and OVCAR3 were promising especially regarding A2780 cell line (IC50: 77.0 μg/mL), which was comparable to taxol (IC50:76.9 μg/mL).

Dual anticancer activity of Aspergillus nidulans pigment and Ionizing γ-Radiation on human larynx carcinoma cell line

BACKGROUND

Fungi are a readily available source of naturally generated colored compounds. These compounds might be used as radiosensitizers for treating cancer cells.

METHODS

Aspergillus nidulans was examined for its color-producing ability in Potato dextrose agar (PDA) broth medium. The pigment was characterized by Ultraviolet (UV) spectrophotometer and Gas Chromatography Mass Spectrometry (GC/MS). Pigment extracts from A. nidulans were studied for their cytotoxic effects on the growth of human larynx carcinoma cell line (HEp-2) with or without exposure to γ-radiation at three different doses (5, 10, and 15 Gy). A. nidulans pigment cytotoxic activity was tested against normal Vero cells. Cell apoptosis was studied using flow cytometry. Gene expression of P53, Caspase 3 and Bcl-2 were quantified.

RESULTS

Ultraviolet spectrum and GC/MS revealed the ability of Aspergillus nidulans to produce Rhodopin pigment. HEp-2 cells treated with A. nidulans pigment only give IC50 about 208 µg/ml. In contrast, when treated with the pigment +10 Gy γ-radiation, it give about 115 µg/ml. However, for normal cells, lower cytotoxic activity was detected. Treatment with pigment (208 g/mL) caused about 50% ± 1.0 total apoptosis level and gene expression of P53: 2.3 fold and Caspase 3: 1.84 fold in respect to untreated HEp-2), while Bcl-2 was decreased (Bcl-2: 0.63 fold in respect to untreated HEp-2). Furthermore, treated with pigment (115 µg/mL) + 10Gy caused about 47.41% ± 1.7 total apoptosis level and P53: 2.53 fold and Caspase 3: 2.0 fold in respect to untreated HEp-2, while Bcl-2 was downregulated (Bcl-2: 0.61 fold in respect to untreated HEp-2).

CONCLUSION

This study concluded that the anti-cancer activity of Aspergillus nidulans pigment was enhanced by ionizing radiation at 10 Gy, as well as its low cytotoxic activity against normal Vero cells.

Predicting metastasis at initial diagnosis and radiotherapy effectiveness in patients with metastatic osteosarcoma

Osteosarcoma is a primary malignant bone tumor affecting mostly children and adolescents. The overall 10 year survivals of patients with metastatic osteosarcoma are typically less than 20% in the literature and remain concerning. We aimed to develop a nomogram for predicting the risk of metastasis at initial diagnosis in patients with osteosarcoma and evaluate the effectiveness of radiotherapy in patients with metastatic osteosarcoma. Clinical and demographic data of patients with osteosarcoma were collected from the surveillance, epidemiology, and end results database. We randomly split our analytical sample into the training and validation cohorts, then established and validated a nomogram for predicting the risk of osteosarcoma metastasis at initial diagnosis. The effectiveness of radiotherapy was evaluated by performing propensity score matching in patients underwent surgery + chemotherapy and those underwent surgery + chemotherapy + radiotherapy, among patients with metastatic osteosarcoma. 1439 patients met the inclusion criteria and were included in this study. 343 of 1439 had osteosarcoma metastasis by the time of initial presentation. A nomogram for predicting the likelihood of osteosarcoma metastasis by the time of initial presentation was developed. In both unmatched and matched samples, the radiotherapy group demonstrated a superior survival profile comparing with the non-radiotherapy group. Our study established a novel nomogram to evaluate the risk of osteosarcoma with metastasis, and demonstrated that radiotherapy combined with chemotherapy and surgical resection could improve 10-year survival in patients with metastasis. These findings may guide the clinical decision-making for orthopedic surgeons.

Molecular mechanisms of ROS-modulated cancer chemoresistance and therapeutic strategies

Drug resistance is the main obstacle to achieving a cure in many cancer patients. Reactive oxygen species (ROS) are master regulators of cancer development that act through complex mechanisms. Remarkably, ROS levels and antioxidant content are typically higher in drug-resistant cancer cells than in non-resistant and normal cells, and have been shown to play a central role in modulating drug resistance. Therefore, determining the underlying functions of ROS in the modulation of drug resistance will contribute to develop therapies that sensitize cancer resistant cells by leveraging ROS modulation. In this review, we summarize the notable literature on the sources and regulation of ROS production and highlight the complex roles of ROS in cancer chemoresistance, encompassing transcription factor-mediated chemoresistance, maintenance of cancer stem cells, and their impact on the tumor microenvironment. We also discuss the potential of ROS-targeted therapies in overcoming tumor therapeutic resistance.

Enhanced Chemodynamic Therapy Mediated by a Tumor-Specific Catalyst in Synergy with Mitophagy Inhibition Improves the Efficacy for Endometrial Cancer

Chemodynamic therapy (CDT) relies on the tumor microenvironment (e.g., high H2 O2 level) responsive Fenton-like reactions to produce hydroxyl radicals (·OH) against tumors. However, endogenous H2 O2 is insufficient for effective chemodynamic responses. An NAD(P)H: quinone oxidoreductase 1 (NQO1)high catalase (CAT)low therapeutic window for the use of NQO1 bioactive drug β-lapachone (β-Lap) is first identified in endometrial cancer (EC). Accompanied by NADH depletion, NQO1 catalyzes β-Lap to produce excess H2 O2 and initiate oxidative stress, which selectively suppress NQO1high EC cell proliferation, induce DNA double-strand breaks, and promote apoptosis. Moreover, shRNA-mediated NQO1 knockdown or dicoumarol rescues NQO1high EC cells from β-Lap-induced cytotoxicity. Arginine-glycine-aspartic acid (RGD)-functionalized iron-based metal-organic frameworks (MOF(Fe)) further promote the conversion of the accumulated H2 O2 into highly oxidative ·OH, which in turn, exacerbates the oxidative damage to RGD-positive target cells. Furthermore, mitophagy inhibition by Mdivi-1 blocks a powerful antioxidant defense approach, ultimately ensuring the anti-tumor efficacy of stepwise-amplified reactive oxygen species signals. The tumor growth inhibition rate (TGI) is about 85.92%. However, the TGI of MOF(Fe)-based synergistic antitumor therapy decreases to only 50.46% in NQO1-deficient KLE tumors. Tumor-specific chemotherapy and CDT-triggered therapeutic modality present unprecedented therapeutic benefits in treating NQO1high EC.

Atherosclerosis, Diabetes Mellitus, and Cancer: Common Epidemiology, Shared Mechanisms, and Future Management

The involvement of cardiovascular disease in cancer onset and development represents a contemporary interest in basic science. It has been recognized, from the most recent research, that metabolic syndrome-related conditions, ranging from atherosclerosis to diabetes, elicit many pathways regulating lipid metabolism and lipid signaling that are also linked to the same framework of multiple potential mechanisms for inducing cancer. Otherwise, dyslipidemia and endothelial cell dysfunction in atherosclerosis may present common or even interdependent changes, similar to oncogenic molecules elevated in many forms of cancer. However, whether endothelial cell dysfunction in atherosclerotic disease provides signals that promote the pre-clinical onset and proliferation of malignant cells is an issue that requires further understanding, even though more questions are presented with every answer. Here, we highlight the molecular mechanisms that point to a causal link between lipid metabolism and glucose homeostasis in metabolic syndrome-related atherosclerotic disease with the development of cancer. The knowledge of these breakthrough mechanisms may pave the way for the application of new therapeutic targets and for implementing interventions in clinical practice.

Inhibition of Autophagy and the Cytoprotective Role of Smac Mimetic against ROS-Induced Cancer: A Potential Therapeutic Strategy in Relapse and Chemoresistance Cases in Breast Cancer

With more than a million deaths each year, breast cancer is the top cause of death in women. Around 70% of breast cancers are hormonally responsive. Although several therapeutic options exist, cancer resistance and recurrence render them inefficient and insufficient. The major key reason behind this is the failure in the regulation of the cell death mechanism. In addition, ROS was also found to play a major role in this problem. The therapeutic benefits of Smac mimetic compound (SMC) BV6 on MCF7 were examined in the current study. Treatment with BV6 reduces viability and induces apoptosis in MCF7 breast cancer cells. BV6 suppresses autophagy and has demonstrated a defensive role in cancer cells against oxidative stress caused by H₂O₂. Overall, the present investigation shows that SMC has therapeutic and cytoprotective potential against oxidative stress in cancer cells. These Smac mimetic compounds may be used as anti-cancer drugs as well as antioxidants alone or in conjunction with other commonly used antioxidants.

Lycium ruthenicum Murr. anthocyanins inhibit hyperproliferation of synovial fibroblasts from rheumatoid patients and the mechanism study powered by network pharmacology

BACKGROUND

Rheumatoid arthritis (RA), is a typical autoimmune disease affecting nearly 1% of the world's population. The dysfunctional hyperproliferation of synovial fibroblast (SF) in articular cartilage of RA patients is considered as the essential etiology. Traditional chemotherapeutic agents for RA treatment are imperfect for their high cost and unpredictable side-effects. L. ruthenicum anthocyanins (LRAC) is a natural product that of potential for therapeutic application against RA.

METHODS

LRAC was characterized by UPLC-MS/MS. Bioinformatics analyses based on network pharmacology were applied to predict the potential targets of LRAC, and to select DEGs (differentially expressed genes) caused by RA pathogenesis from GSE77298. Interactions between LRAC and the predicted targets were evaluated by molecular docking. Effects of LRAC on SFs from RA patients were examined by in vitro assays, which were analyzed by flow cytometry and western blotting (WB).

RESULTS

LRAC was able to inhibit the abnormal proliferation and aggressive invasion of SFs from RA patients. LRAC was mainly constituted by petunidin (82.7%), with small amount of delphinidin (12.9%) and malvidin (4.4%) in terms of anthocyanidin. Bioinformatics analyses showed that in 3738 RA-related DEGs, 58 of them were collectively targeted by delphinidin, malvidin and delphinidin. AR, CDK2, CHEK1, HIF1A, CXCR4, MMP2 and MMP9, the seven hub genes constructed a central network mediating the signal transduction. Molecular docking confirmed the high affinities between the LRAC ligands and the protein receptors encoded by the hub genes. The in vitro assays validated that LRAC repressed the growth of RASF by cell cycle arresting and cell invasion paralyzing (c-Myc/p21/CDK2), initiating cell apoptosis (HIF-1α/CXCR4/Bax/Bcl-2), and inducing pyroptosis via ROS-dependent pathway (NOX4/ROS/NLRP3/IL-1β/Caspase-1).

CONCLUSION

LRAC can selectively inhibit the proliferation of RASFs, without side-effecting immunosuppression that usually occurred for RA treatment using MTX (methotrexate). These findings demonstrate the potential application of LRAC as a phytomedicine for RA treatment, and provide a valid approach for exploring natural remedies against autoimmune diseases.

Cisplatin in Liver Cancer Therapy

Hepatocellular carcinoma (HCC) is the most common primary liver tumor and is often diagnosed at an unresectable advanced stage. Systemic chemotherapy as well as transarterial chemoembolization (TACE) and hepatic arterial infusion chemotherapy (HAIC) are used to treat advanced HCC. TACE and HAIC have long been the standard of care for patients with unresectable HCC but are limited to the treatment of intrahepatic lesions. Systemic chemotherapy with doxorubicin or chemohormonal therapy with tamoxifen have also been considered, but neither has demonstrated survival benefits. In the treatment of unresectable advanced HCC, cisplatin is administered transhepatic arterially for local treatment. Subsequently, for cisplatin-refractory cases due to drug resistance, a shift to systemic therapy with a different mechanism of action is expected to produce new antitumor effects. Cisplatin is also used for the treatment of liver tumors other than HCC. This review summarizes the action and resistance mechanism of cisplatin and describes the treatment of the major hepatobiliary cancers for which cisplatin is used as an anticancer agent, with a focus on HCC.

Bone Marrow Mesenchymal Stem Cells Induce Metabolic Plasticity in Estrogen Receptor-Positive Breast Cancer

Cancer cells reprogram energy metabolism through metabolic plasticity, adapting ATP-generating pathways in response to treatment or microenvironmental changes. Such adaptations enable cancer cells to resist standard therapy. We employed a coculture model of estrogen receptor-positive (ER+) breast cancer and mesenchymal stem cells (MSC) to model interactions of cancer cells with stromal microenvironments. Using single-cell endogenous and engineered biosensors for cellular metabolism, coculture with MSCs increased oxidative phosphorylation, intracellular ATP, and resistance of cancer cells to standard therapies. Cocultured cancer cells had increased MCT4, a lactate transporter, and were sensitive to the MCT1/4 inhibitor syrosingopine. Combining syrosingopine with fulvestrant, a selective estrogen receptor degrading drug, overcame resistance of ER+ breast cancer cells in coculture with MSCs. Treatment with antiestrogenic therapy increased metabolic plasticity and maintained intracellular ATP levels, while MCT1/4 inhibition successfully limited metabolic transitions and decreased ATP levels. Furthermore, MCT1/4 inhibition decreased heterogenous metabolic treatment responses versus antiestrogenic therapy. These data establish MSCs as a mediator of cancer cell metabolic plasticity and suggest metabolic interventions as a promising strategy to treat ER+ breast cancer and overcome resistance to standard clinical therapies.

IMPLICATIONS

This study reveals how MSCs reprogram metabolism of ER+ breast cancer cells and point to MCT4 as potential therapeutic target to overcome resistance to antiestrogen drugs.

Protoporphyrin IX-loaded albumin nanoparticles reverse cancer chemoresistance by enhancing intracellular reactive oxygen species

Chemoresistance is the main cause of chemotherapy failure in ovarian cancer (OC). The enhanced scavenging of reactive oxygen species (ROS) by the thioredoxin system resulted in insufficient intracellular concentrations of effective ROS, leading to chemoresistance. To induce OC cell apoptosis by enhancing intracellular ROS levels, protoporphyrin IX (PpIX) and albumin-bound PTX nanoparticles (APNP) were utilized to fabricate APNP-PpIX nanoparticles. APNP-PpIX effectively generated ROS and increased the effective ROS concentration in chemoresistant cancer cells. The in vitro and in vivo experiments confirmed the effective inhibition of APNP-PpIX on chemoresistant OC cell proliferation and tumor formation. APNP-PpIX significantly improved the effectiveness of chemotherapy and photodynamic therapy, thus providing a new approach for the clinical treatment of chemoresistant OC.

H2O2 Self-Supplying and GSH-Depleting Nanocatalyst for Copper Metabolism-Based Synergistic Chemodynamic Therapy and Chemotherapy

Chemodynamic therapy (CDT) that involves the use of Fenton catalysts to convert endogenous hydrogen peroxide (H₂O₂) to hydroxyl radicals (·OH) constitutes a promising strategy for cancer therapy; however, insufficient endogenous H₂O₂ and glutathione (GSH) overexpression render its efficiency unsatisfactory. Herein, we present an intelligent nanocatalyst that comprises copper peroxide nanodots and DOX-loaded mesoporous silica nanoparticles (MSNs) (DOX@MSN@CuO₂) and can self-supply exogenous H₂O₂ and respond to specific tumor microenvironments (TME). Following endocytosis into tumor cells, DOX@MSN@CuO₂ initially decomposes into Cu²⁺ and exogenous H₂O₂ in the weakly acidic TME. Subsequently, Cu²⁺ reacts with high GSH concentrations, thereby inducing GSH depletion and reducing Cu²⁺ to Cu⁺ Next, the generated Cu⁺ undergoes Fenton-like reactions with exogenous H₂O₂ to accelerate toxic ·OH production, which exhibits a rapid reaction rate and is responsible for tumor cell apoptosis, thereby enhancing CDT. Furthermore, the successful delivery of DOX from the MSNs achieves chemotherapy and CDT integration. Thus, this excellent strategy can resolve the problem of insufficient CDT efficacy due to limited H₂O₂ and GSH overexpression. Integrating H₂O₂ self-supply and GSH deletion enhances CDT, and DOX-induced chemotherapy endows DOX@MSN@CuO₂ with effective tumor growth-inhibiting properties alongside minimal side effects in vivo.

Polystyrene nanoplastics inhibit StAR expression by activating HIF-1α via ERK1/2 MAPK and AKT pathways in TM3 Leydig cells and testicular tissues of mice

Microplastics (MPs) and nanoplastics (NPs) are widely found in water, food and air, and have been found in human blood, lung and feces. Several studies in vivo have shown that MPs and NPs decrease testosterone level. However, the molecular mechanism of MPs and NPs leading to testosterone reduction remains unclear. In the present study, mice were treated with 50 μg/kg·day polystyrene (PS)-NPs by tail vein injection once daily for two consecutive days, the mRNA and protein levels of steroidogenic acute regulatory protein (StAR) decreased significantly in testis. TM3 Leydig cells were treated with non-toxic doses of PS-NPs, hypoxia-inducible factor-1α (HIF-1α) mRNA translation was induced by PS-NPs through mTOR/4E-BP1 pathway, which was activated by the ERK1/2 MAPK and AKT pathways. Simultaneously, increased HIF-1α protein inhibited StAR transcription. Additionally, reactive oxygen species production induced by PS-NPs played a central role in the activation of ERK1/2 MAPK/mTOR and AKT/mTOR signaling pathways. These results suggest that PS-NPs down-regulate StAR expression by increasing HIF-1α, which is induced by activation of mTOR/4E-BP1 through the ERK1/2 MAPK and AKT signaling pathways. Our findings provide new insight into the potential molecular mechanism by which PS-NPs impair testosterone synthesis and male reproductive function.

Oxidation Responsive PEGylated Polyamino Acid Bearing Thioether Pendants for Enhanced Anticancer Drug Delivery

Reactive oxygen species (ROS) in biological tissues are in a state of dynamic balance. However, many diseases such as cancer and inflammation, are accompanied by a long-term increase in ROS. This situation inspires researchers to use ROS-sensitive nanocarriers for a site-specific release of cargo in pathological areas. Polyamino acid materials with good biodegradability, biocompatibility, and regular secondary structure are widely used in the biomedical field. Herein, a new oxidation responsive PEGylated polyamino acid is synthesised for anticancer drug delivery by ring-opening polymerisation of N-carboxyanhydrides bearing thioether pendants. The obtained block copolymer mPEG-b-PMLG self-assembles into spherical nanoparticles (NPs) in water with diameter ≈68.3 nm. NMR measurement demonstrated that the hydrophobic thioether pendants in the NPs can be selectively oxidised to hydrophilic sulfoxide groups by H₂ O₂ , which will lead to the disassociation of NPs. In vitro drug release results indicated that the encapsulated Nile red is selectively released in the trigger of 10 mM H₂ O₂ in PBS. Finally, anticancer drug doxorubicin (DOX) is encapsulated to the NPs, and the obtained NPs/DOX exhibits an improved antitumor efficacy in 4T1 tumour-bearing mice and lower cardiotoxicity than free DOX. These results indicates that the mPEG-b-PMLG NPs are promising for anticancer drug delivery.

Imidazolyl Ethanamide Pentandioic Acid (IEPA) as Potential Radical Scavenger during Tumor Therapy in Human Hematopoietic Stem Cells

Radiochemotherapy-associated leuco- or thrombocytopenia is a common complication, e.g., in head and neck cancer (HNSCC) and glioblastoma (GBM) patients, often compromising treatments and outcomes. Currently, no sufficient prophylaxis for hematological toxicities is available. The antiviral compound imidazolyl ethanamide pentandioic acid (IEPA) has been shown to induce maturation and differentiation of hematopoietic stem and progenitor cells (HSPCs), resulting in reduced chemotherapy-associated cytopenia. In order for it to be a potential prophylaxis for radiochemotherapy-related hematologic toxicity in cancer patients, the tumor-protective effects of IEPA should be precluded. In this study, we investigated the combinatorial effects of IEPA with radio- and/or chemotherapy in human HNSCC and GBM tumor cell lines and HSPCs. Treatment with IEPA was followed by irradiation (IR) or chemotherapy (ChT; cisplatin, CIS; lomustine, CCNU; temozolomide, TMZ). Metabolic activity, apoptosis, proliferation, reactive oxygen species (ROS) induction, long-term survival, differentiation capacity, cytokine release, and DNA double-strand breaks (DSBs) were measured. In tumor cells, IEPA dose-dependently diminished IR-induced ROS induction but did not affect the IR-induced changes in metabolic activity, proliferation, apoptosis, or cytokine release. In addition, IEPA showed no protective effect on the long-term survival of tumor cells after radio- or chemotherapy. In HSPCs, IEPA alone slightly enhanced CFU-GEMM and CFU-GM colony counts (2/2 donors). The IR- or ChT-induced decline of early progenitors could not be reversed by IEPA. Our data indicate that IEPA is a potential candidate for the prevention of hematologic toxicity in cancer treatment without affecting therapeutic benefits.

Reactive oxygen species-upregulating nanomedicines towards enhanced cancer therapy

Reactive oxygen species (ROS) play a crucial role in physiological and pathological processes, emerging as a therapeutic target in cancer. Owing to the high concentration of ROS in solid tumor tissues, ROS-based treatments, such as photodynamic therapy and chemodynamic therapy, and ROS-responsive drug delivery systems have been widely explored to powerfully and specifically suppress tumors. However, their anticancer efficacy is still hampered by the heterogeneous ROS levels, and thus comprehensively upregulating the ROS levels in tumor tissues can ensure an enhanced therapeutic effect, which can further sensitize and/or synergize with other therapies to inhibit tumor growth and metastasis. Herein, we review the recently emerging drug delivery strategies and technologies for increasing the H₂O₂, ˙OH, ¹O₂, and ˙O₂^- concentrations in cancer cells, including the efficient delivery of natural enzymes, nanozymes, small molecular biological molecules, and nanoscale Fenton-reagents and semiconductors and neutralization of intracellular antioxidant substances and localized input of mechanical and electromagnetic waves (such as ultrasound, near infrared light, microwaves, and X-rays). The applications of these ROS-upregulating nanosystems in enhancing and synergizing cancer therapies including chemotherapy, chemodynamic therapy, phototherapy, and immunotherapy are surveyed. In addition, we discuss the challenges of ROS-upregulating systems and the prospects for future studies.

Unraveling the Peculiar Features of Mitochondrial Metabolism and Dynamics in Prostate Cancer

Prostate cancer (PCa) is the second leading cause of cancer deaths among men in Western countries. Mitochondria, the "powerhouse" of cells, undergo distinctive metabolic and structural dynamics in different types of cancer. PCa cells experience peculiar metabolic changes during their progression from normal epithelial cells to early-stage and, progressively, to late-stage cancer cells. Specifically, healthy cells display a truncated tricarboxylic acid (TCA) cycle and inefficient oxidative phosphorylation (OXPHOS) due to the high accumulation of zinc that impairs the activity of m-aconitase, the enzyme of the TCA cycle responsible for the oxidation of citrate. During the early phase of cancer development, intracellular zinc levels decrease leading to the reactivation of m-aconitase, TCA cycle and OXPHOS. PCa cells change their metabolic features again when progressing to the late stage of cancer. In particular, the Warburg effect was consistently shown to be the main metabolic feature of late-stage PCa cells. However, accumulating evidence sustains that both the TCA cycle and the OXPHOS pathway are still present and active in these cells. The androgen receptor axis as well as mutations in mitochondrial genes involved in metabolic rewiring were shown to play a key role in PCa cell metabolic reprogramming. Mitochondrial structural dynamics, such as biogenesis, fusion/fission and mitophagy, were also observed in PCa cells. In this review, we focus on the mitochondrial metabolic and structural dynamics occurring in PCa during tumor development and progression; their role as effective molecular targets for novel therapeutic strategies in PCa patients is also discussed.

A novel ROS-activable self-immolative prodrug for tumor-specific amplification of oxidative stress and enhancing chemotherapy of mitoxantrone

Reactive oxygen species (ROS) as well-known endogenous stimuli has been widely used to activate drug delivery systems (DDSs) for tumor-specific therapy. Unfortunately, endogenous ROS in the tumor microenvironment (TME) is not enough to achieve effective therapeutic efficacy and cancer cells have adapted to high oxidative stress by upregulating glutathione (GSH) level. Herein, we devised a novel ROS-activable self-immolative prodrug CASDB with both GSH-depletion ability and ROS self-supply competence. Then, an stimuli-responsive nanoplatform integrating CASDB with clinical chemotherapeutics mitoxantrone (MTO) and PLGA was fabricated (denoted as CMPs) through nanoprecipitation method. The CMPs could achieve desired accumulation at tumor tissues through enhanced permeability and retention (EPR) effects. Then the accumulated CMPs could induce tumor cell apoptosis efficiently. Especially, ROS in tumor sites could trigger the immolation of CASDB to generate CA and quinone methide (QM). Then CA and QM cooperatively promoted damage of mitochondria due to oxidative stress and led to cancer cells more sensitive to MTO. Accordingly, MTO could perturb cellular microenvironment of cancer cells then promote the degradation of CASDB. The experiment results demonstrated that CMPs were ideal for desirable synergetic tumor-specific anticancer therapy with negligible systemic toxicity. The half-maximal inhibitory concentrations (IC50) value of CMPs was 6.53 μM, while the IC50 values of MTO was 14.76 μM. And the CMPs group showed the strongest tumor suppressor effect with the tumor sizes increased to 1.2-fold (Control group: 20.6-fold, MTO only: 3.0-fold). This study should be inspirational for designing efficient prodrugs to overcome the handicaps of traditional chemotherapy.

The Curcuminoid EF24 in Combination with TRAIL Reduces Human Renal Cancer Cell Migration by Decreasing MMP-2/MMP-9 Activity through a Reduction in H2O2

Cancer cells present high levels of oxidative stress, and although an increase in reactive oxygen species (ROS), such as H₂O₂, can lead to apoptosis, it can also induce cell invasion and metastasis. As the increase in ROS can lead to an increase in the expression of MMP-2 and MMP-9, thus causing the degradation of the extracellular matrix, an increase in the ROS H₂O₂ might have an impact on MMP-2/MMP-9 activity. The natural compound curcumin has shown some anticancer effects, although its bioavailability hinders its therapeutic potential. However, curcumin and its analogues were shown to resensitize kidney cancer cells to TNF-related apoptosis-inducing ligand (TRAIL)-induced apoptosis. This study shows that the curcuminoid EF24 in combination with TRAIL increases peroxidase activity in the renal adenocarcinoma cell line ACHN, reducing the level of intracellular H₂O₂ and MMP-2/MMP-9 activity, a mechanism that is also observed after treatment with curcumin and TRAIL.

Review on Metal-Based Theranostic Nanoparticles for Cancer Therapy and Imaging

Theranostic agents are promising due to their ability to diagnose, treat and monitor different types of cancer using a variety of imaging modalities. The advantage specifically of nanoparticles is that they can accumulate easily at the tumor site due to the large gaps in blood vessels near tumors. Such high concentration of theranostic agents at the target site can lead to enhancement in both imaging and therapy. This article provides an overview of nanoparticles that have been used for cancer theranostics, and the different imaging, treatment options and signaling pathways that are important when using nanoparticles for cancer theranostics. In particular, nanoparticles made of metal elements are emphasized due to their wide applications in cancer theranostics. One important aspect discussed is the ability to combine different types of metals in one nanoplatform for use as multimodal imaging and therapeutic agents for cancer.

Molecular mechanisms behind ROS regulation in cancer: A balancing act between augmented tumorigenesis and cell apoptosis

ROS include hydroxyl radicals (HO^.), superoxide (O₂^..), and hydrogen peroxide (H₂O₂). ROS are typically produced under physiological conditions and play crucial roles in living organisms. It is known that ROS, which are created spontaneously by cells through aerobic metabolism in mitochondria, can have either a beneficial or detrimental influence on biological systems. Moderate levels of ROS can cause oxidative damage to proteins, DNA and lipids, which can aid in the pathogenesis of many disorders, including cancer. However, excessive concentrations of ROS can initiate programmed cell death in cancer. Presently, a variety of chemotherapeutic drugs and herbal agents are being investigated to induce ROS-mediated cell death in cancer. Therefore, preserving ROS homeostasis is essential for ensuring normal cell development and survival. On account of a significant association of ROS levels at various concentrations with carcinogenesis in a number of malignancies, further studies are needed to determine the underlying molecular mechanisms and develop the possibilities for intervening in these processes.

Lactoferrin and Activated Protein C: Potential Role in Prevention of Cancer Progression and Recurrence

Existing therapeutic interventions for controlling cancer are limited and associated with side effects. Furthermore, the recurrence of cancer poses a significant challenge to the cure of cancer. Therefore, avenues are wanted to find novel therapies for cancer treatment and cancer recurrence. In this review, we have highlighted that lactoferrin (LF) and activated protein C (APC) carry enormous potential in cancer treatment. Studies have shown that the decreased level of APC and impaired function of APC are associated with cancer progression and cancer-related mortality. Moreover, APC plays an important role in preventing prothrombotic state-mediated cancer progression and deaths. LF can also inhibit the progression of cancer by controlling the generation of reactive oxygen species, triggering the apoptosis of cancer cells, arresting the cell cycle and hindering the angiogenesis process. Additionally, APC and LF could have the potential to inhibit neutrophil extracellular traps (NETs) formations which are involved in cancer progression and the reawakening of dormant cancer cells. Hence, in this review, the anticancer potential and mechanism of APC and LF along with their potential to mitigate inflammation and NETs-mediated cancer progression and recurrence has been discussed. Additionally, possible future strategies to develop effective and safe anticancer treatment using LF and APC have also been discussed in this review.

Real-time simultaneous imaging of temporal alterations in cytoplasmic and mitochondrial redox in single cells during cell division and cell death

Cytosolic and organelle redox are highly interrelated, and their alterations play critical roles in both physiological and pathological cell states. This highly regulated process is crucial in life-death decisions of cells. Among organelles, the mitochondrion is the major source of intracellular-ROS and contributes to oxidation damage-induced cell death. Increase in cytosolic-redox and mitochondrial-redox is evident in cells undergoing diverse forms of cell death, such as apoptosis, necrosis, and necroptosis. The hierarchical profiling of redox signaling at the cytosol and mitochondria in a single cell is important to understand the relative contribution of each species in the initiation and shaping of cell death. Here, we demonstrate the potential application of ratiometric redox GFP (roGFP) and intensity-based redox-sensitive RFP (rxRFP) targeted to mitochondria in revealing both rapid and slow progressing changes in redox during cell division and in cells undergoing multiple modes of cell death. To generate imaging quality signal, single-cell clones stably expressing both roGFP at the cytosol and rxRFP probes targeted to mitochondria were generated. The cells provided sufficient temporal resolution with imaging-ready signal for the real-time visualization of rapidly progressing redox alterations at the cytosol and mitochondria. The long-time imaging of the cells revealed that a moderate increase in cytosolic ROS marks the division stage. Similarly, distinct forms of cell death trigger a unique and temporally regulated redox change at the cytosol and mitochondria, suggesting the potential utility of the sensor cells to dissect the nature of cell death pathways induced by specific forms of stress.

Possible role of nuclear factor erythroid 2-related factor 2 in the progression of human colon precancerous lesions

BACKGROUND

Increased levels of oxidative stress/cell inflammation contribute to colorectal cancer (CRC) onset. Nuclear factor-erythroid 2-related factor 2 (Nrf2) and its controlled growth factor erv1-like (Gfer) gene regulate redox-sensitive and anti-inflammatory mechanisms, respectively, which can contribute to promoting cancer development.

AIM

We evaluated Nrf2 and Gfer RNA expression and Nrf2 protein expression in colon mucosa in order to establish their possible involvement in the early stage of CRC.

METHODS

Forty subjects were enrolled after a histological evaluation of their colon biopsies. They included 20 subjects with a sporadic colorectal adenoma (SpCA group) and 20 without precancerous lesions (controls). Biopsy samples were processed for gene expression analysis and protein expression, using Real-time PCR and immunofluorescence confocal microscopy, respectively.

RESULTS

Nrf2 and Gfer mRNA expression were significantly reduced (p=0.007 and p<0.003, respectively) in SpCA tissues compared to normal mucosa from controls. Furthermore, immunofluorescence analysis confirmed a relevant reduction of Nrf2 in SpCA tissue compared to normal tissue from controls.

CONCLUSIONS

Our data confirm the hypothesis that Nrf2 and Gfer expression may be involved in the initial hits contributing to the multistep process of colon carcinogenesis. Further larger studies are needed to confirm if Nrf2 and Gfer are potential risk/prognostic factors for cancer development.

Oxidative Stress Response in Adipose Tissue-Derived Mesenchymal Stem/Stromal Cells

Reactive oxygen species (ROS) can irreversibly damage biological molecules, a process known as oxidative stress. Elevated ROS levels are associated with immune cell activation. Sustained immune system activation can affect many different cells in the environment. One cell type that has been detected in almost all tissues of the body is mesenchymal stem/stromal cells (MSC). MSC possess proliferation and differentiation potential, thus facilitating regeneration processes. However, the regenerative capacity of MSC might be impaired by oxidative stress, and the effects of long-term oxidative stress on MSC functions are sparsely described. The examination of oxidative stress is often performed by exposure to H2O2. Since H2O2 is rapidly degraded, we additionally exposed the cell cultures to glucose oxidase (GOx), resulting in sustained exposure to H2O2. Using these model systems, we have focused on the effects of short- and long-term oxidative stress on viability, migration, differentiation, and signaling. All cellular functions examined were affected by the applied oxidative stress. The differences that occur between pulsed and sustained oxidative stress indicated higher oxidative stress in MSC upon direct H2O2 exposure, whereas the GOx-induced prolonged exposure to H2O2 seems to allow for better cellular adaptation. The mechanisms underlying these different responses are currently unknown.

Ivermectin and curcumin cause plasma membrane rigidity in Leishmania amazonensis due to oxidative stress

Spin label electron paramagnetic resonance (EPR) spectroscopy was used to study the mechanisms of action of ivermectin and curcumin against Leishmania (L.) amazonensis promastigotes. EPR spectra showed that treatment of the parasites with both compounds results in plasma membrane rigidity due to oxidative processes. With the IC₅₀ and EPR measurements for assays using different parasite concentrations, estimations could be made for the membrane-water partition coefficient (K_M/W), and the concentration of the compound in the membrane (c_m50) and in the aqueous phase (c_w50), which inhibits cell growth by 50%. The K_M/W values indicated that ivermectin has a greater affinity than curcumin for the parasite membrane. Therefore, the activity of ivermectin was higher for experiments with low cell concentrations, but for concentrations greater than 1.5 × 10⁸ parasites/mL the compounds did not show significantly different results. The c_m50 values indicated that the concentration of compound in the membrane leading to growth inhibition or membrane alteration is approximately 1 M for both ivermectin and curcumin. This high membrane concentration suggests that many ivermectin molecules per chlorine channel are needed to cause an increase in chlorine ion influx.

Amlexanox-modified platinum(IV) complex triggers apoptotic and autophagic bimodal death of cancer cells

Platinum(IV) prodrugs c,c,t-[PtCl₂(NH₃)₂(OH)(amlexanox)] (MAP) and c,c,t-[PtCl₂(NH₃)₂(amlexanox)₂] (DAP) were synthesized by reacting amlexanox with oxoplatin and characterized by NMR, HR-MS, HPLC, and elemental analysis. The complexes could be reduced to platinum(II) species and amlexanox to exert antitumor activity. Generally, MAP was more potent than DAP and cisplatin towards various human cancer cell lines; particularly, it was active in cisplatin-resistant Caov-3 ovarian cancer and A549/DDP lung cancer cells. MAP induced serious damage to DNA, remarkable change in mitochondrial morphology, decrease in mitochondrial membrane potential, release of cytochrome c from mitochondria, and up-regulation of pro-apoptotic protein Bax in Caov-3 cells, thereby leading to evident apoptosis. Meanwhile, MAP markedly promoted the autophagic flux, including affecting the expression of microtubule-associated protein light chain 3 (LC3) and autophagy adaptor protein p62 in Caov-3 cells, with an increase in the ratio of LC3-II/LC3-I and a decrease in p62, thus trigging the occurrence of autophagy. The MAP-induced bimodal cell death mode is uncommon for platinum complexes, which presents a new possibility to invent anticancer drugs with unique mechanism of action.

Jensen L. Reactive Oxygen Species-Responsive Polymer Nanoparticles to Improve the Treatment of Inflammatory Skin Diseases

To improve the quality of life for people living with chronic inflammatory skin diseases, we propose a new treatment strategy by exploring a stimuli-responsive drug delivery system. Formulations designed by exploiting smart materials can be programmed to perform a specific action upon exposure to disease-related stimuli. For instance, increased levels of reactive oxygen species (ROS), especially the accumulation of hydrogen peroxide, can be utilized to differentiate between healthy and inflamed tissues. In this concept-proofing study, the polymer poly(1,4 phenyleneacetone dimethylene thioketal) (PPADT) was investigated for its ROS-responsive properties and potential to treat inflammatory skin diseases. PPADT nanoparticles were formulated by oil-in-water emulsification followed by solvent evaporation and characterized by size, zeta-potential, and release kinetic profiles. Release profiles revealed that the PPADT nanoparticles were sensitive toward elevated levels of ROS in an ROS-stimulus concentration (0.1-10 mM) and time-dependent manner (flare-up mimicked). The safety assessment proved that the PPADT polymer and the monomers generated by oxidation do not show any sign of being cytotoxic to fibroblasts and no mutagenic liabilities were observed. In conclusion, the PPADT polymer demonstrated to be a promising material for stimuli-responsive delivery of hydrophobic small molecules in the treatment of inflammatory skin diseases.

Metabolic Reprogramming Helps to Define Different Metastatic Tropisms in Colorectal Cancer

Approximately 25% of colorectal cancer (CRC) patients experience systemic metastases, with the most frequent target organs being the liver and lung. Metabolic reprogramming has been recognized as one of the hallmarks of cancer. Here, metabolic and functional differences between two CRC cells with different metastatic organotropisms (metastatic KM12SM CRC cells to the liver and KM12L4a to the lung when injected in the spleen and in the tail vein of mice) were analysed in comparison to their parental non-metastatic isogenic KM12C cells, for a subsequent investigation of identified metabolic targets in CRC patients. Meta-analysis from proteomic and transcriptomic data deposited in databases, qPCR, WB, in vitro cell-based assays, and in vivo experiments were used to survey for metabolic alterations contributing to their different organotropism and for the subsequent analysis of identified metabolic markers in CRC patients. Although no changes in cell proliferation were observed between metastatic cells, KM12SM cells were highly dependent on oxidative phosphorylation at mitochondria, whereas KM12L4a cells were characterized by being more energetically efficient with lower basal respiration levels and a better redox management. Lipid metabolism-related targets were found altered in both cell lines, including LDLR, CD36, FABP4, SCD, AGPAT1, and FASN, which were also associated with the prognosis of CRC patients. Moreover, CD36 association with lung metastatic tropism of CRC cells was validated in vivo. Altogether, our results suggest that LDLR, CD36, FABP4, SCD, FASN, LPL, and APOA1 metabolic targets are associated with CRC metastatic tropism to the liver or lung. These features exemplify specific metabolic adaptations for invasive cancer cells which stem at the primary tumour.

RNA 5-methylcytosine status is associated with DNMT2/TRDMT1 nuclear localization in osteosarcoma cell lines

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Selected phenotypic features of three osteosarcoma (OS) cell lines were evaluated.

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Redox disequilibrium promoted sustained AKT and ERK1/2 activation.

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Redox imbalance modulated cell death pathways in OS cells.

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Nuclear levels of TRDMT1 methyltransferase were associated with RNA methylation.

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A novel marker for predicting therapy response in OS patients is proposed.

Osteosarcoma (OS) is a pediatric malignant bone tumor with unsatisfying improvements in survival rates due to limited understanding of OS biology and potentially druggable targets. The present study aims to better characterize osteosarcoma U-2 OS, SaOS-2, and MG-63 cell lines that are commonly used as in vitro models of OS. We focused on evaluating the differences in cell death pathways, redox equilibrium, the activity of proliferation-related signaling pathways, DNA damage response, telomere maintenance, DNMT2/TRDMT1-based responses and RNA 5-methylcytosine status. SaOS-2 cells were characterized by higher levels of superoxide and nitric oxide that promoted AKT and ERK1/2 activation thus modulating cell death pathways. OS cell lines also differed in the levels and localization of DNA repair regulator DNMT2/TRDMT1. SaOS-2 cells possessed the lowest levels of total, cytoplasmic and nuclear DNMT2/TRDMT1, whereas in MG-63 cells, the highest levels of nuclear DNMT2/TRDMT1 were associated with the most pronounced status of RNA 5-methylcytosine. In silico analysis revealed potential phosphorylation sites at DNMT2/TRDMT1 that may be related to the regulation of DNMT2/TRDMT1 localization. We postulate that redox homeostasis, proliferation-related pathways and DNMT2/TRDMT1-based effects can be modulated as a part of anti-osteosarcoma strategy reflecting diverse phenotypic features of OS cells.

An update of Nrf2 activators and inhibitors in cancer prevention/promotion

NF-E2-related factor 2 (Nrf2) protein is a basic-region leucine zipper transcription factor that defends against endogenous or exogenous stressors. By inducing several cytoprotective and detoxifying gene expressions, Nrf2 can increase the sensitivity of the cells to oxidants and electrophiles. Transient Nrf2 activation, by its specific activators, has protective roles against carcinogenesis and cancer development. However, permanent activation of Nrf2 promotes various cancer properties, comprising malignant progression, chemo/radio resistance, and poor patient prognosis. Taken together, these findings suggest that reaching an optimal balance between paradoxical functions of Nrf2 in malignancy may render a selective improvement to identify therapeutic strategies in cancer treatment. In this review, we describe lately discovered Nrf2 inducers and inhibitors, and their chemopreventive and/or anticancer activities.

The Nrf2 pathway signifies one of the most significant cell defense procedures against exogenous or endogenous stressors. Certainly, by increasing the expression of several cytoprotective genes, the transcription factor Nrf2 can shelter cells and tissues from multiple sources of damage including electrophilic, xenobiotic, metabolic, and oxidative stress. Notably, the aberrant activation or accumulation of Nrf2, a common event in many tumors, confers a selective advantage to cancer cells and is connected to malignant progression, therapy resistance, and poor prognosis. Therefore, lately, Nrf2 has arisen as a hopeful target in treatment of cancer, and many struggles have been made to detect therapeutic strategies intended at disrupting its pro-oncogenic role. By summarizing the outcomes from past and recent studies, this review provided an overview concerning the Nrf2 pathway and the molecular mechanisms causing Nrf2 hyperactivation in cancer cells. Finally, this paper also described some of the most promising therapeutic approaches that have been successfully employed to counteract Nrf2 activity in tumors, with a particular emphasis on the development of natural compounds and the adoption of drug repurposing strategies.