ROS homeostasis and metabolism: a dangerous liason in cancer cells

High-dose synthetic phenolic antioxidant propyl gallate impairs mouse oocyte meiotic maturation through inducing mitochondrial dysfunction and DNA damage

Propyl gallate (PG) is one of the most widely used antioxidants in food products, cosmetics and pharmaceutical industries. Increased research has suggested that exposure to PG influences reproductive health in humans and animals. However, until now, it has not yet been confirmed whether PG would impact oocyte quality. In this study, the hazardous effects of PG on oocyte meiotic maturation were investigated in mice. The findings showed that PG exposure compromises oocyte meiosis by inducing mitochondrial stress which activates apoptosis to trigger oocyte demise. Moreover, DNA damage was significantly induced in PG-treated oocytes, which might be another cause of oocyte developmental arrest and degeneration. Besides, the level of histone methylation (H3K27me2 and H3K27me3) in oocyte was also significantly increased by PG exposure. Furthermore, PG-induced oxidative stress was validated by the increased level of reactive oxygen species (ROS), which might be the underlying reason for these abnormities. In conclusion, the foregoing findings suggested that PG exposure impaired oocyte meiotic maturation by yielding mitochondrial stress to activate apoptosis, inducing DNA damage and oxidative stress, and altering histone methylation level.

Redox signaling regulates the skeletal tissue development and regeneration

Skeletal tissue development and regeneration in mammals are intricate, multistep, and highly regulated processes. Various signaling pathways have been implicated in the regulation of these processes, including redox. Redox signaling is the signal transduction by electron transfer reactions involving free radicals or related species. Redox homeostasis is essential to cell metabolic states, as the ROS not only regulates cell biological processes but also mediates physiological processes. Following a bone fracture, redox signaling is also triggered to regulate bone healing and regeneration by targeting resident stromal cells, osteoblasts, osteoclasts and endothelial cells. This review will focus on how the redox signaling impact the bone development and bone regeneration.

Weakly supervised identification of microscopic human breast cancer-related optical signatures from normal-appearing breast tissue

With the latest advancements in optical bioimaging, rich structural and functional information has been generated from biological samples, which calls for capable computational tools to identify patterns and uncover relationships between optical characteristics and various biomedical conditions. Constrained by the existing knowledge of the novel signals obtained by those bioimaging techniques, precise and accurate ground truth annotations can be difficult to obtain. Here we present a weakly supervised deep learning framework for optical signature discovery based on inexact and incomplete supervision. The framework consists of a multiple instance learning-based classifier for the identification of regions of interest in coarsely labeled images and model interpretation techniques for optical signature discovery. We applied this framework to investigate human breast cancer-related optical signatures based on virtual histopathology enabled by simultaneous label-free autofluorescence multiharmonic microscopy (SLAM), with the goal of exploring unconventional cancer-related optical signatures from normal-appearing breast tissues. The framework has achieved an average area under the curve (AUC) of 0.975 on the cancer diagnosis task. In addition to well-known cancer biomarkers, non-obvious cancer-related patterns were revealed by the framework, including NAD(P)H-rich extracellular vesicles observed in normal-appearing breast cancer tissue, which facilitate new insights into the tumor microenvironment and field cancerization. This framework can be further extended to diverse imaging modalities and optical signature discovery tasks.

Targeting Mitochondria with ClpP Agonists as a Novel Therapeutic Opportunity in Breast Cancer

Breast cancer is the most frequently diagnosed malignancy worldwide and the leading cause of cancer mortality in women. Despite the recent development of new therapeutics including targeted therapies and immunotherapy, triple-negative breast cancer remains an aggressive form of breast cancer, and thus improved treatments are needed. In recent decades, it has become increasingly clear that breast cancers harbor metabolic plasticity that is controlled by mitochondria. A myriad of studies provide evidence that mitochondria are essential to breast cancer progression. Mitochondria in breast cancers are widely reprogrammed to enhance energy production and biosynthesis of macromolecules required for tumor growth. In this review, we will discuss the current understanding of mitochondrial roles in breast cancers and elucidate why mitochondria are a rational therapeutic target. We will then outline the status of the use of mitochondria-targeting drugs in breast cancers, and highlight ClpP agonists as emerging mitochondria-targeting drugs with a unique mechanism of action. We also illustrate possible drug combination strategies and challenges in the future breast cancer clinic.

To metabolomics and beyond: a technological portfolio to investigate cancer metabolism

Tumour cells have exquisite flexibility in reprogramming their metabolism in order to support tumour initiation, progression, metastasis and resistance to therapies. These reprogrammed activities include a complete rewiring of the bioenergetic, biosynthetic and redox status to sustain the increased energetic demand of the cells. Over the last decades, the cancer metabolism field has seen an explosion of new biochemical technologies giving more tools than ever before to navigate this complexity. Within a cell or a tissue, the metabolites constitute the direct signature of the molecular phenotype and thus their profiling has concrete clinical applications in oncology. Metabolomics and fluxomics, are key technological approaches that mainly revolutionized the field enabling researchers to have both a qualitative and mechanistic model of the biochemical activities in cancer. Furthermore, the upgrade from bulk to single-cell analysis technologies provided unprecedented opportunity to investigate cancer biology at cellular resolution allowing an in depth quantitative analysis of complex and heterogenous diseases. More recently, the advent of functional genomic screening allowed the identification of molecular pathways, cellular processes, biomarkers and novel therapeutic targets that in concert with other technologies allow patient stratification and identification of new treatment regimens. This review is intended to be a guide for researchers to cancer metabolism, highlighting current and emerging technologies, emphasizing advantages, disadvantages and applications with the potential of leading the development of innovative anti-cancer therapies.

Xiaojianzhong decoction prevents gastric precancerous lesions in rats by inhibiting autophagy and glycolysis in gastric mucosal cells

BACKGROUND

Gastric precancerous lesions (GPL) precede the development of gastric cancer (GC). They are characterized by gastric mucosal intestinal metaplasia and dysplasia caused by various factors such as inflammation, bacterial infection, and injury. Abnormalities in autophagy and glycolysis affect GPL progression, and their effective regulation can aid in GPL treatment and GC prevention. Xiaojianzhong decoction (XJZ) is a classic compound for the treatment of digestive system diseases in ancient China which can inhibit the progression of GPL. However, its specific mechanism of action is still unclear.

AIM

To investigate the therapeutic effects of XJZ decoction on a rat GPL model and the mechanisms underlying its effects on autophagy and glycolysis regulation in GPLs.

METHODS

Wistar rats were randomly divided into six groups of five rats each and all groups except the control group were subjected to GPL model construction for 18 wk. The rats’ body weight was monitored every 2 wk starting from the beginning of modeling. Gastric histopathology was examined using hematoxylin-eosin staining and Alcian blue-periodic acid-Schiff staining. Autophagy was observed using transmission electron microscopy. The expressions of autophagy, hypoxia, and glycolysis related proteins in gastric mucosa were detected using immunohistochemistry and immunofluorescence. The expressions of the following proteins in gastric tissues: B cell lymphoma/Leukemia-2 and adenovirus E1B19000 interacting protein 3 (Bnip-3), microtubule associated protein 1 light chain 3 (LC-3), moesin-like BCL2-interacting protein 1 (Beclin-1), phosphatidylinositol 3-kimase (PI3K), protein kinase B (AKT), mammalian target of rapamycin (mTOR), p53, AMP-activated protein kinase (AMPK), and Unc-51 like kinase 1 (ULK1) were detected using western blot. The relative expressions of autophagy, hypoxia, and glycolysis related mRNA in gastric tissues was detected using reverse transcription-polymerase chain reaction.

RESULTS

Treatment with XJZ increased the rats’ body weight and improved GPL-related histopathological manifestations. It also decreased autophagosome and autolysosome formation in gastric tissues and reduced Bnip-3, Beclin-1, and LC-3II expressions, resulting in inhibition of autophagy. Moreover, XJZ down-regulated glycolysis-related monocarboxylate transporter (MCT1), MCT4, and CD147 expressions. XJZ prevented the increase of autophagy level by decreasing gastric mucosal hypoxia, activating the PI3K/AKT/mTOR pathway, inhibiting the p53/AMPK pathway activation and ULK1 Ser-317 and Ser-555 phosphorylation. In addition, XJZ improved abnormal gastric mucosal glucose metabolism by ameliorating gastric mucosal hypoxia and inhibiting ULK1 expression.

CONCLUSION

This study demonstrates that XJZ may inhibit autophagy and glycolysis in GPL gastric mucosal cells by improving gastric mucosal hypoxia and regulating PI3K/AKT/mTOR and p53/ AMPK/ULK1 signaling pathways, providing a feasible strategy for the GPL treatment.

Epigenetic-Metabolic Interplay in the DNA Damage Response and Therapeutic Resistance of Breast Cancer

Therapy resistance is imposing a daunting challenge on effective clinical management of breast cancer. Although the development of resistance to drugs is multifaceted, reprogramming of energy metabolism pathways is emerging as a central but heterogenous regulator of this therapeutic challenge. Metabolic heterogeneity in cancer cells is intricately associated with alterations of different signaling networks and activation of DNA damage response pathways. Here we consider how the dynamic metabolic milieu of cancer cells regulates their DNA damage repair ability to ultimately contribute to development of therapy resistance. Diverse epigenetic regulators are crucial in remodeling the metabolic landscape of cancer. This epigenetic-metabolic interplay profoundly affects genomic stability of the cancer cells as well as their resistance to genotoxic therapies. These observations identify defining mechanisms of cancer epigenetics-metabolism-DNA repair axis that can be critical for devising novel, targeted therapeutic approaches that could sensitize cancer cells to conventional treatment strategies.

Diselenide-triggered hydroxyethyl starch conjugate nanoparticles with cascade drug release properties for potentiating chemo-photodynamic therapy

A novel type of diselenide bond-bridged hydroxyethyl starch-doxorubicin conjugate, HES-SeSe-DOX, was synthesized via a specially designed multistep synthetic route. The optimally achieved HES-SeSe-DOX was further combined with photosensitizer, chlorin E6 (Ce6), to self-assemble into HES-SeSe-DOX/Ce6 nanoparticles (NPs) for potentiating chemo-photodynamic anti-tumor therapy via diselenide-triggered cascade actions. HES-SeSe-DOX/Ce6 NPs were observed to disintegrate through the cleavage or oxidation of diselenide-bridged linkages in response to the stimuli arising from glutathione (GSH), hydrogen peroxide and Ce6-induced singlet oxygen, respectively, as evidenced by the enlarged size with irregular shapes and cascade drug release. In vitro cell studies exhibited that HES-SeSe-DOX/Ce6 NPs in combination with laser irradiation effectively consumed intracellular GSH and promoted a large rise in levels of reactive oxygen species in tumor cells, actuating the disruption of intracellular redox balance and the enhanced chemo-photodynamic cytotoxicity against tumor cells. The in vivo investigations revealed that HES-SeSe-DOX/Ce6 NPs were inclined to accumulate in tumors with persistent fluorescence emission, inhibited tumor growth with high efficacy and had good safety. These findings demonstrate the potential of HES-SeSe-DOX/Ce6 NPs for use in chemo-photodynamic tumor therapy and suggest their viability for clinical translation.

Involvement of redox signalling in tumour cell dormancy and metastasis

Decades of research on oncogene-driven carcinogenesis and gene-expression regulatory networks only started to unveil the complexity of tumour cellular and molecular biology. This knowledge has been successfully implemented in the clinical practice to treat primary tumours. In contrast, much less progress has been made in the development of new therapies against metastasis, which are the main cause of cancer-related deaths. More recently, the role of epigenetic and microenviromental factors has been shown to play a key role in tumour progression. Free radicals are known to communicate the intracellular and extracellular compartments, acting as second messengers and exerting a decisive modulatory effect on tumour cell signalling. Depending on the cellular and molecular context, as well as the intracellular concentration of free radicals and the activation status of the antioxidant system of the cell, the signalling equilibrium can be tilted either towards tumour cell survival and progression or cell death. In this regard, recent advances in tumour cell biology and metastasis indicate that redox signalling is at the base of many cell-intrinsic and microenvironmental mechanisms that control disseminated tumour cell fate and metastasis. In this manuscript, we will review the current knowledge about redox signalling along the different phases of the metastatic cascade, including tumour cell dormancy, making emphasis on metabolism and the establishment of supportive microenvironmental connections, from a redox perspective.

The phototoxicity action spectra of visible light in HaCaT keratinocytes

Visible light (VL) surely affects human skin in several ways, exerting positive (tissue regeneration, pain relief) and negative (oxidation, inflammation) effects, depending on the radiation dose and wavelength. Nevertheless, VL continues to be largely disregarded in photoprotection strategies, perhaps because the molecular mechanisms occurring during the interaction of VL with endogenous photosensitizers (ePS) and the subsequent biological responses are still poorly understood. Besides, VL encompass photons with different properties and interaction capacities with the ePS, but there are no quantitative comparisons of their effects on humans. Here, we studied the effects of physiologically relevant doses of four wavelengths ranges of VL, i.e. (in nm), 408-violet, 466/478-blue, 522-green, 650-red, in immortalized human skin keratinocytes (HaCaT). The level of cytotoxicity/damage follows the order: violet>blue >green>red. Violet and blue light induced the highest levels of Fpg-sensitive lesions in nuclear DNA, oxidative stress, lysosomal and mitochondrial damage, disruption of the lysosomal-mitochondrial axis of cell homeostasis, blockade of the autophagic flux, as well as lipofuscin accumulation, greatly increasing the toxicity of wideband VL to human skin. We hope this work will stimulate in development of optimized sun protection strategies.

The Yin and Yang Effect of the Apelinergic System in Oxidative Stress

Apelin is an endogenous ligand for the G protein-coupled receptor APJ and has multiple biological activities in human tissues and organs, including the heart, blood vessels, adipose tissue, central nervous system, lungs, kidneys, and liver. This article reviews the crucial role of apelin in regulating oxidative stress-related processes by promoting prooxidant or antioxidant mechanisms. Following the binding of APJ to different active apelin isoforms and the interaction with several G proteins according to cell types, the apelin/APJ system is able to modulate different intracellular signaling pathways and biological functions, such as vascular tone, platelet aggregation and leukocytes adhesion, myocardial activity, ischemia/reperfusion injury, insulin resistance, inflammation, and cell proliferation and invasion. As a consequence of these multifaceted properties, the role of the apelinergic axis in the pathogenesis of degenerative and proliferative conditions (e.g., Alzheimer's and Parkinson's diseases, osteoporosis, and cancer) is currently investigated. In this view, the dual effect of the apelin/APJ system in the regulation of oxidative stress needs to be more extensively clarified, in order to identify new potential strategies and tools able to selectively modulate this axis according to the tissue-specific profile.

Association between Iron Deficiency and Survival in Older Patients with Cancer

BACKGROUND

iron deficiency (ID) is frequent in older patients.

PURPOSE

to evaluate the association between ID and survival in patients ≥ 75 years old with confirmed solid tumors.

METHODS

a retrospective monocentric study including patients between 2009 and 2018. ID, absolute ID (AID) and functional ID (FID) were defined according to the European Society for Medical Oncology (ESMO) criteria. Severe ID was defined by a ferritin level < 30 µg/L.

RESULTS

in total, 556 patients were included, the mean age was 82 (±4.6) years, 56% were male, the most frequent cancer was colon cancer (19%, n = 104), and metastatic cancers were found in 38% (n = 211). Median follow-up time: 484 [190-1377] days. In anemic patients, ID and FID were independently associated with an increased risk of mortality (respectively, HR 1.51; p = 0.0065 and HR 1.73; p = 0.0007). In non-anemic patients, FID was independently associated with better survival (HR 0.65; p = 0.0495).

CONCLUSION

in our study, ID was significantly associated with survival, and with better survival for patients without anemia. These results suggest that attention should be paid to the iron status in older patients with tumors and raise questions about the prognostic value of iron supplementation for iron-deficient patients without anemia.

Mitochondrial SENP2 regulates the assembly of SDH complex under metabolic stress

Succinate dehydrogenase (SDH) is a heterotetrameric enzyme complex belonging to the mitochondrial respiratory chain and uniquely links the tricarboxylic acid (TCA) cycle with oxidative phosphorylation. Cancer-related SDH mutations promote succinate accumulation, which is regarded as an oncometabolite. Post-translational modifications of SDH complex components are known to regulate SDH activity, although the contribution of SUMOylation remains unclear. Here, we show that SDHA is SUMOylated by PIAS3 and deSUMOylated by SENP2, events dictating the assembly and activity of the SDH complex. Moreover, CBP acetylation of SENP2 negatively regulates its deSUMOylation activity. Under glutamine deprivation, CBP levels decrease, and the ensuing SENP2 activation and SDHA deSUMOylation serve to concurrently dampen the TCA cycle and electron transport chain (ETC) activity. Along with succinate accumulation, this mechanism avoids excessive reactive oxygen species (ROS) production to promote cancer cell survival. This study elucidates a major function of mitochondrial-localized SENP2 and expands our understanding of the role of SUMOylation in resolving metabolic stress.

Co-Targeting of BTK and TrxR as a Therapeutic Approach to the Treatment of Lymphoma

Diffuse large B-cell lymphoma (DLBCL) is a haematological malignancy representing the most diagnosed non-Hodgkin's lymphoma (NHL) subtype. Despite the approved chemotherapies available in clinics, some patients still suffer from side effects and relapsed disease. Recently, studies have reported the role of the Trx system and the BCR signalling pathway in cancer development and drug resistance. In this regard, we assessed a potential link between the two systems and evaluated the effects of [Au(d2pype)₂]Cl (TrxR inhibitor) and ibrutinib (BTK inhibitor) alone and in combination on the cell growth of two DLBCL lymphoma cell lines, SUDHL2 and SUDHL4. In this study, we show higher expression levels of the Trx system and BCR signalling pathway in the DLBCL patient samples compared to the healthy samples. The knockdown of TrxR using siRNA reduced BTK mRNA and protein expression. A combination treatment with [Au(d2pype)₂]Cl and ibrutinib had a synergistic effect on the inhibition of lymphoma cell proliferation, the activation of apoptosis, and, depending on lymphoma cell subtype, ferroptosis. Decreased BTK expression and the cytoplasmic accumulation of p65 were observed after the combination treatment in the DLBCL cells, indicating the inhibition of the NF-κB pathway. Thus, the co-targeting of BTK and TrxR may be an effective therapeutic strategy to consider for DLBCL treatment.

Stimuli-Responsive Gene Delivery Nanocarriers for Cancer Therapy

Gene therapy provides a promising approach in treating cancers with high efficacy and selectivity and few adverse effects. Currently, the development of functional vectors with safety and effectiveness is the intense focus for improving the delivery of nucleic acid drugs for gene therapy. For this purpose, stimuli-responsive nanocarriers displayed strong potential in improving the overall efficiencies of gene therapy and reducing adverse effects via effective protection, prolonged blood circulation, specific tumor accumulation, and controlled release profile of nucleic acid drugs. Besides, synergistic therapy could be achieved when combined with other therapeutic regimens. This review summarizes recent advances in various stimuli-responsive nanocarriers for gene delivery. Particularly, the nanocarriers responding to endogenous stimuli including pH, reactive oxygen species, glutathione, and enzyme, etc., and exogenous stimuli including light, thermo, ultrasound, magnetic field, etc., are introduced. Finally, the future challenges and prospects of stimuli-responsive gene delivery nanocarriers toward potential clinical translation are well discussed. The major objective of this review is to present the biomedical potential of stimuli-responsive gene delivery nanocarriers for cancer therapy and provide guidance for developing novel nanoplatforms that are clinically applicable.

Targeting Mitochondrial IDH2 Enhances Antitumor Activity of Cisplatin in Lung Cancer via ROS-Mediated Mechanism

Mitochondrial isocitrate dehydrogenase 2 (IDH2) is an important metabolic enzyme in the tricarboxylic acid cycle (TCA) cycle. Our previous study showed that high expression of wild-type IDH2 promotes the proliferation of lung cancer cells. This study aims to test the potential of targeting IDH2 as a therapeutic strategy to inhibit lung cancer in vitro and in vivo. First, we analyzed the available data from the databases gene expression omnibus (GEO) database to evaluate the clinical relevance of IDH2 expression in affecting lung cancer patient survival. We then generated a stable IDH2-knockdown lung cancer cell line using a lentivirus-based method for in vitro and in vivo study. Cell growth, apoptosis, cell viability, and colony formation assays were conducted to test the sensitivity of lung cancer cells with different IDH2 expression status to cisplatin or radiation treatment in vitro. For mechanistic study, Cellular oxygen consumption and extracellular acidification rates were measured using a Seahorse metabolic analyzer, and reactive oxygen species (ROS) generation was analyzed using flow cytometry. An animal study using a xenograft tumor model was performed to further evaluate the in vivo therapeutic effect on tumor growth. We found that high IDH2 expression was associated with poor survival in lung cancer patients undergoing chemotherapy. Inhibition of IDH2 significantly enhanced the anticancer activity of cisplatin and also increased the effect of radiation against lung cancer cells. IDH2 was upregulated in cisplatin-resistant lung cancer cells, which could be sensitized by targeted inhibition of IDH2. Mechanistic study showed that abrogation of IDH2 caused only minimal changes in oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) in lung cancer cells, but induced a significant increase in ROS, which rendered the cancer cells more sensitive to cisplatin. Pretreatment of lung cancer cells with the ROS scavenger N-acetyl-cysteine could partially rescue cells from the cytotoxic effect of cisplatin and IDH2 inhibition. Importantly, abrogation of IDH2 significantly increased the sensitivity of lung cancer cells to cisplatin in vivo.

Phytochemicals and mitochondria: Therapeutic allies against gastric cancer

BACKGROUND

Mitochondria are the energy factories of cells with the ability to modulate the cell cycle, cellular differentiation, signal transduction, growth, and apoptosis. Existing drugs targeting mitochondria in cancer treatment have disadvantages of drug resistance and side effects. Phytochemicals, which are widely found in plants, are bioactive compounds that could facilitate the development of new drugs for gastric cancer. Studies have shown that some phytochemicals can suppress the development of gastric cancer.

METHODS

We searched for data from PubMed, China National Knowledge Infrastructure, Web of Science, and Embase databases from initial establishment to December 2021 to review the mechanism by which phytochemicals suppress gastric cancer cell growth by modulating mitochondrial function. Phytochemicals were classified and summarized by their mechanisms of action.

RESULTS

Phytochemicals can interfere with mitochondria through several mechanisms to reach the goal of promoting apoptosis in gastric cancer cells. Some phytochemicals, e.g., daidzein and tetrandrine promoted cytochrome c spillover into the cytoplasm by modulating the members of the B-cell lymphoma-2 protein family and induced apoptotic body activity by activating the caspase protein family. Phytochemicals (e.g., celastrol and shikonin) could promote the accumulation of reactive oxygen species and reduce the mitochondrial membrane potential. Several phytochemicals (e.g., berberine and oleanolic acid) activated mitochondrial apoptotic submission via the phosphatidylinositol-3-kinase/Akt signaling pathway, thereby triggering apoptosis in gastric cancer cells. Several well-known phytochemicals that target mitochondria, including berberine, ginsenoside, and baicalein, showed the advantages of multiple targets, high efficacy, and fewer side effects.

CONCLUSIONS

Phytochemicals could target the mitochondria in the treatment of gastric cancer, providing potential directions and evidence for clinical translation. Drug discovery focused on phytochemicals has great potential to break barriers in cancer treatment.

A robust Au@Cu2-xS nanoreactor assembled by silk fibroin for enhanced intratumoral glucose depletion and redox dyshomeostasis

Intracellular redox dyshomeostasis promoted by tumor microenvironment (TME) modulation has become an appealing therapeutic target for cancer management. Herein, a dual plasmonic Au/SF@Cu_2-xS nanoreactor (abbreviation as ASC) is elaborately developed by covalent immobilization of sulfur defective Cu_2-xS nanodots onto the surface of silk fibroin (SF)-capped Au nanoparticles. Tumor hypoxia can be effectively alleviated by ASC-mediated local oxygenation, owing to the newfound catalase-mimic activity of Cu_2-xS. The semiconductor of Cu_2-xS with narrow bandgap energy of 2.54 eV enables a more rapid dissociation of electron-hole (e^-/h⁺) pair for a promoted US-triggered singlet oxygen (¹O₂) generation, in the presence of Au as electron scavenger. Moreover, Cu_2-xS is devote to Fenton-like reaction to catalyze H₂O₂ into ·OH under mild acidity and simultaneously deplete glutathione to aggravate intracellular oxidative stress. In another aspect, Au nanoparticles with glucose oxidase-mimic activity consumes intrinsic glucose, which contributes to a higher degree of oxidative damage and energy exhaustion of cancer cells. Importantly, such tumor starvation and ¹O₂ yield can be enhanced by Cu_2-xS-catalyzed O₂ self-replenishment in H₂O₂-rich TME. ASC-initiated M1 macrophage activation and therapy-triggered immunogenetic cell death (ICD) favors the systematic tumor elimination by eliciting antitumor immunity. This study undoubtedly enriches the rational design of SF-based nanocatalysts for medical utilizations.

Nanoscale coordination polymers enabling antioxidants inhibition for enhanced chemodynamic therapy

Reactive oxygen species (ROS) generation to induce cell death is an effective strategy for cancer therapy. In particular, chemodynamic therapy (CDT), using Fenton-type reactions to generate highly cytotoxic hydroxyl radical (•OH), is a promising treatment modality. However, the therapeutic efficacy of ROS-based cancer treatment is still limited by some critical challenges, such as overexpression of enzymatic and non-enzymatic antioxidants by tumor cells, as well as the low tumor targeting efficiency of therapeutic agents. To address those problems, biomimetic CuZn protoporphyrin IX nanoscale coordination polymers have been developed, which significantly amplify oxidative stress against tumors by simultaneously inhibiting enzymatic and non-enzymatic antioxidants and initiating the CDT. In this design, cancer cell membrane camouflaged nanoparticle exhibits an excellent homotypic targeting effect. After being endocytosed into tumor cells, the nanoparticles induce depletion of the main non-enzymatic antioxidant glutathione (GSH) by undergoing a redox reaction with GSH. Afterward, the redox reaction generated cuprous ion (Cu⁺) works as a CDT agent for •OH generation. Furthermore, the released Zn protoporphyrin IX strongly inhibits the activity of the typical enzymatic antioxidant heme oxygenase-1. This tetra-modal synergistic strategy endows the biomimetic nanoparticles with great capability for anticancer therapy, which has been demonstrated in both in vitro and in vivo studies.

Effective or Harmful-Evaluation of Locally Applied Antibiotics on Adipose Tissue during Lipofilling to the Breast-An In Vitro Study

Lipofilling is a frequently used and safe procedure for breast reconstruction. One of the most feared complications is soft tissue infection following lipofilling. Because of this, some surgeons propose the practice of rinsing fat grafts with antibiotics. This study investigates the effect of antibiotic rinses on fat grafts in an in vitro model. Adipocytes and stem cells were isolated from fat tissue harvested during 24 lipofilling procedures and incubated with different doses of clindamycin or cefazolin. Cell viability, metabolism, proliferation, and differentiation capacities were analyzed by gross morphology, fluorescence staining, -(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromid (MTT-), and Glyceraldehyde 3 Phosphate Dehydrogenase (G3PD)-assay as well as reactive oxygen species (ROS)-assay. Cefazolin and clindamycin led to significant reduction of cell viability of adipocytes. High doses of both antibiotics led to a rupture of adipocytes with visible free lipid droplets. Cell metabolism was significantly decreased after incubation with both antibiotics. There was a significant increase in ROS production. Exposure to clindamycin and cefazolin led to morphological changes in stem cells in a dose- and time-dependent manner. Furthermore, differentiation potential was significantly reduced. Antibiotic susceptibility testing, however, showed that low concentrations of antibiotics effectively inhibited bacterial growth in contaminated fat grafts. This study confirms that rinsing fat grafts with clindamycin or cefazolin not only overly prevents infection but also has cytotoxic and metabolic effects on adipocytes. Therefore, based on these results, the routine clinical application in high doses cannot be recommended.

PHB2 promotes colorectal cancer cell proliferation and tumorigenesis through NDUFS1-mediated oxidative phosphorylation

The alteration of cellular energy metabolism is a hallmark of colorectal cancer (CRC). Accumulating evidence has suggested oxidative phosphorylation (OXPHOS) is upregulated to meet the demand for energy in tumor initiation and development. However, the role of OXPHOS and its regulatory mechanism in CRC tumorigenesis and progression remain unclear. Here, we reveal that Prohibitin 2 (PHB2) expression is elevated in precancerous adenomas and CRC, which promotes cell proliferation and tumorigenesis of CRC. Additionally, knockdown of PHB2 significantly reduces mitochondrial OXPHOS levels in CRC cells. Meanwhile, NADH:ubiquinone oxidoreductase core subunit S1 (NDUFS1), as a PHB2 binding partner, is screened and identified by co-immunoprecipitation and mass spectrometry. Furthermore, PHB2 directly interacts with NDUFS1 and they co-localize in mitochondria, which facilitates NDUFS1 binding to NADH:ubiquinone oxidoreductase core subunit V1 (NDUFV1), regulating the activity of complex I. Consistently, partial inhibition of complex I activity also abrogates the increased cell proliferation induced by overexpression of PHB2 in normal human intestinal epithelial cells and CRC cells. Collectively, these results indicate that increased PHB2 directly interacts with NDUFS1 to stabilize mitochondrial complex I and enhance its activity, leading to upregulated OXPHOS levels, thereby promoting cell proliferation and tumorigenesis of CRC. Our findings provide a new perspective for understanding CRC energy metabolism, as well as novel intervention strategies for CRC therapeutics.

NOX Dependent ROS Generation and Cell Metabolism

Reactive oxygen species (ROS) represent a group of high reactive molecules with dualistic natures since they can induce cytotoxicity or regulate cellular physiology. Among the ROS, the superoxide anion radical (O2·-) is a key redox signaling molecule prominently generated by the NADPH oxidase (NOX) enzyme family and by the mitochondrial electron transport chain. Notably, altered redox balance and deregulated redox signaling are recognized hallmarks of cancer and are involved in malignant progression and resistance to drugs treatment. Since oxidative stress and metabolism of cancer cells are strictly intertwined, in this review, we focus on the emerging roles of NOX enzymes as important modulators of metabolic reprogramming in cancer. The NOX family includes seven isoforms with different activation mechanisms, widely expressed in several tissues. In particular, we dissect the contribute of NOX1, NOX2, and NOX4 enzymes in the modulation of cellular metabolism and highlight their potential role as a new therapeutic target for tumor metabolism rewiring.

Dual inhibition of thioredoxin reductase and proteasome is required for auranofin-induced paraptosis in breast cancer cells

Auranofin (AF), a gold (I)-containing phosphine compound, is being investigated for oncological application as a repurposed drug. We show here that 4~5 µM AF induces paraptosis, a non-apoptotic cell death mode characterized by dilation of the endoplasmic reticulum (ER) and mitochondria, in breast cancer cells. Although the covalent inhibition of thioredoxin reductase (TrxR), an enzyme that critically controls intracellular redox homeostasis, is considered the primary mechanism of AF's anticancer activity, knockdown of TrxR1 did not induce paraptosis. Instead, both TrxR1 knockdown plus the proteasome inhibitor (PI), bortezomib (Bz), and 2 μM AF plus Bz induced paraptosis, thereby mimicking the effect of 5 μM AF. These results suggest that the paraptosis induced by 5 μM AF requires the inhibition of both TrxR1 and proteasome. We found that TrxR1 knockdown/Bz or subtoxic doses of AF and Bz induced paraptosis selectively in breast cancer cells, sparing non-transformed MCF10A cells, whereas 4~5 μM AF killed both cancer and MCF10A cells. GSH depletion was found to be more critical than ROS generation for the paraptosis induced by dual TrxR1/proteasome inhibition. In this process, the ATF4/CHAC1 (glutathione-specific gamma-glutamylcyclotransferase 1) axis leads to GSH degradation, contributing to proteotoxic stress possibly due to the accumulation of misfolded thiol-containing proteins. These results suggest that the paraptosis-inducing strategy of AF plus a PI may provide an effective therapeutic strategy against pro-apoptotic therapy-resistant cancers and reduce the potential side effects associated with high-dose AF.

Enhancement of Human Epidermal Cell Defense against UVB Damage by Fermentation of Passiflora edulis Sims Peel with Saccharomyces cerevisiae

The processing of Passiflora edulis Sims results in large amounts of wasted peel resources and environmental pollution. In order to improve the utilisation of natural plant resources and economic benefits, this study uses Saccharomyces cerevisiae to ferment Passiflora edulis Sims peel to obtain Passiflora edulis Sims peel fermentation broth (PF). The content of active substances in unfermented Passiflora edulis Sims peel water extract (PW) and PF is then determined, as well as their in vitro antioxidant capacity. The protective effects of PF and PW on UVB-induced skin inflammation and skin barrier damage in human immortalised epidermal keratinocytes (HaCaT) cells (including cell viability, ROS, HO-1, NQO1, IL-1β, IL-8, TNF-α, KLK-7, FLG, AQP3 and Caspase 14 levels) are investigated. Studies have shown that PF enhances the content of active substances more effectively compared to PW, showing a superior ability to scavenge free radical scavenging and antioxidants. PW and PF can effectively scavenge excess intracellular ROS, reduce the cellular secretion of pro-inflammatory factors, regulate the content of skin barrier-related proteins and possibly respond to UVB-induced cell damage by inhibiting the activation of the PI3K/AKT/mTOR signalling pathway. Studies have shown that both PW and PF are safe and non-irritating, with PF exploiting the efficacy of Passiflora edulis Sims peel more significantly, providing a superior process for the utilisation of Passiflora edulis Sims waste. At the same time, PF can be developed and used as a functional protective agent against ultraviolet damage to the skin, thereby increasing the value of the use of Passiflora edulis Sims waste.

Potential Role of ROS in Butyrate- and Dietary Fiber-Mediated Growth Inhibition and Modulation of Cell Cycle-, Apoptosis- and Antioxidant-Relevant Proteins in LT97 Colon Adenoma and HT29 Colon Carcinoma Cells

The aim of the present study was to examine whether reactive oxygen species (ROS) contribute to chemopreventive effects of fermentation supernatants (FS) of different dietary fibers (Synergy1^®, oat-, barley-, yeast β-glucan, Curdlan) and butyrate as a fermentation metabolite. LT97 and HT29 cells were treated with butyrate and FS alone or with N-acetyl-cysteine (NAC) and their impact on ROS formation, cell growth, and protein expression (Cyclin D2, p21, PARP, Bid, GPx2) was investigated. Butyrate and FS significantly decreased cell growth. ROS levels were significantly increased, particularly in LT97 cells, while co-treatment with NAC decreased ROS formation and growth inhibitory effects in both cell lines. After treatment with butyrate and FS, Cyclin D2 expression was reduced in LT97 cells and p21 expression was increased in both cell lines. Levels of full-length PARP and Bid were decreased, while levels of cleaved PARP were enhanced. GPx2 expression was significantly reduced by fiber FS in HT29 cells. A notable effect of NAC on butyrate- and FS-modulated protein expression was observed exclusively for PARP and Bid in HT29 cells. From the present results, a contribution of ROS to growth inhibitory and apoptotic effects of butyrate and FS on LT97 and HT29 cells cannot be excluded.

Diets Differently Regulate Tumorigenesis in Young E0771 Syngeneic Breast Cancer Mouse Model

Breast cancer (BC) is the most diagnosed cancer type, accounting for one in eight cancer diagnoses worldwide. Epidemiological studies have shown that obesity is associated with increased risk of BC in post-menopausal women, whereas adiposity reduces the risk of BC in premenopausal women. The mechanistic link between obesity and BC has been examined by combining murine BC models with high-fat diet (HFD) induced obesity. However, the effect of adiposity (not obesity) induced by a short period of HFD consumption on BC pathogenesis is not well understood. In the current study, we examined the effects of different diet compositions on BC pathogenesis using a young E0771 syngeneic BC mouse model fed on either an HFD or regular diet (RD: a low-fat high-carbohydrate diet) for a short period (4 weeks) before implanting mammary tumors in mice. We analyzed the effect of diet composition on the onset of tumor growth, metastasis, and metabolic and immune status in the tumor microenvironment (TME) using various methods including in vivo bioluminescence imaging and immunoblotting analyses. We showed for the first time that a short-term HFD delays the onset of tumorigenesis by altering the immune and metabolic signaling and energy mechanism in the TME. However, RD may increase the risk of tumorigenesis and metastasis by increasing pro-inflammatory factors in the TME in young mice. Our data suggest that diet composition, adipogenesis, and loss of body fat likely regulate the pathogenesis of BC in a manner that differs between young and post-menopausal subjects.

"Smart" drug delivery: A window to future of translational medicine

Chemotherapy is the mainstay of cancer treatment today. Chemotherapeutic drugs are non-selective and can harm both cancer and healthy cells, causing a variety of adverse effects such as lack of specificity, cytotoxicity, short half-life, poor solubility, multidrug resistance, and acquiring cancer stem-like characteristics. There is a paradigm shift in drug delivery systems (DDS) with the advent of smarter ways of targeted cancer treatment. Smart Drug Delivery Systems (SDDSs) are stimuli responsive and can be modified in chemical structure in response to light, pH, redox, magnetic fields, and enzyme degradation can be future of translational medicine. Therefore, SDDSs have the potential to be used as a viable cancer treatment alternative to traditional chemotherapy. This review focuses mostly on stimuli responsive drug delivery, inorganic nanocarriers (Carbon nanotubes, gold nanoparticles, Meso-porous silica nanoparticles, quantum dots etc.), organic nanocarriers (Dendrimers, liposomes, micelles), antibody-drug conjugates (ADC) and small molecule drug conjugates (SMDC) based SDDSs for targeted cancer therapy and strategies of targeted drug delivery systems in cancer cells.

Carrier-Free Immunotherapeutic Nano-Booster with Dual Synergistic Effects Based on Glutaminase Inhibition Combined with Photodynamic Therapy

The immunotherapeutic effect elicited by photodynamic therapy (PDT) is attenuated by tumor defense mechanisms associated with glutamine metabolism, including the metabolic regulation of redox homeostasis and the limitation of the immunosuppressive tumor microenvironment (ITM). Herein, a carrier-free immunotherapeutic nanobooster C9SN with dual synergistic effects was constructed by the self-assembly of glutaminase (GLS) inhibitor compound 968 (C968) and photosensitizer Chlorin e6. C968-mediated GSH deprivation through inhibiting glutamine metabolism prevented PDT-generated reactive oxygen species from being annihilated by GSH, amplifying intracellular oxidative stress, which caused severe cell death and also enhanced the immunogenic cell death (ICD) effect. In addition, genome-wide analysis was carried out using RNA-sequencing to evaluate the changes in cell transcriptome induced by amplifying oxidative stress. Thereafter, neoantigens generated by the enhanced ICD effect promoted the maturation of dendritic cells, thereby recruiting and activating cytotoxic T lymphocytes (CTLs). Meanwhile, C9SN remodeled the ITM by blocking glutamine metabolism to polarize M2-type tumor-associated macrophages (TAMs) into M1-type TAMs, which further recruited and activated the CTLs. Ultimately, this immunotherapeutic nanobooster suppressed primary and distant tumors. This "kill two birds with one stone" strategy would shed light on enhancing tumor immunogenicity and alleviating tumor immunosuppression to improve the immunotherapeutic effect of PDT.

The Double-Edged Sword of Oleuropein in Ovarian Cancer Cells: From Antioxidant Functions to Cytotoxic Effects

Oleuropein plays a key role as a pro-oxidant as well as an antioxidant in cancer. In this study, the activity of oleuropein, in an in vitro model of ovarian (OCCs) and breast cancer cells (BCCs) was investigated. Cell viability and cell death were analyzed. Oxidative stress was measured by CM-H2DCFDA flow cytometry assay. Mitochondrial dysfunction was evaluated based on mitochondrial reactive oxygen species (ROS) and GPX4 protein levels. Further, the effects on iron metabolism were analyzed by measuring the intracellular labile iron pool (LIP). We confirmed that high doses of oleuropein show anti-proliferative and pro-apoptotic activity on HEY and MCF-7 cells. Moreover, our results indicate that low doses of oleuropein impair cell viability without affecting the mortality of cells, and also decrease the LIP and ROS levels, keeping them unchanged in MCF-7 cells. For the first time, our data show that low doses of oleuropein reduce erastin-mediated cell death. Interestingly, oleuropein decreases the levels of intracellular ROS and LIP in OCCs treated with erastin. Noteworthily, we observed an increased amount of ROS scavenging enzyme GPX4 together with a consistent reduction in mitochondrial ROS, confirming a reduction in oxidative stress in this model.

Stress Granules in Cancer

The capacity of cells to organize complex biochemical reactions in intracellular space is a fundamental organizational principle of life. Key to this organization is the compartmentalization of the cytoplasm into distinct organelles, which is frequently achieved through intracellular membranes. Recent evidence, however, has added a new layer of flexibility to cellular compartmentalization. As such, in response to specific stimuli, liquid-liquid phase separations can lead to the rapid rearrangements of the cytoplasm to form membraneless organelles. Stress granules (SGs) are one such type of organelle that form specifically when cells are faced with stress stimuli, to aid cells in coping with stress. Inherently, altered SG formation has been linked to the pathogenesis of diseases associated with stress and inflammatory conditions, including cancer. Exciting discoveries have indicated an intimate link between SGs and tumorigenesis. Several pro-tumorigenic signaling molecules including the RAS oncogene, mTOR, and histone deacetylase 6 (HDAC6) have been shown to upregulate SG formation. Based on these studies, SGs have emerged as structures that can integrate oncogenic signaling and tumor-associated stress stimuli to enhance cancer cell fitness. In addition, growing evidence over the past decade suggests that SGs function not only to regulate the switch between survival and cell death, but also contribute to cancer cell proliferation, invasion, metastasis, and drug resistance. Although much remains to be learned about the role of SGs in tumorigenesis, these studies highlight SGs as a key regulatory hub in cancer and a promising therapeutic target.

Helicobacter pylori-Induced Host Cell DNA Damage and Genetics of Gastric Cancer Development

Gastric cancer is a very serious and deadly disease worldwide with about one million new cases every year. Most gastric cancer subtypes are associated with genetic and epigenetic aberrations caused by chromosome instability, microsatellite instability or Epstein-Barr virus infection. Another risk factor is an infection with Helicobacter pylori, which also triggers severe alterations in the host genome. This pathogen expresses an extraordinary repertoire of virulence determinants that take over control of important host cell signaling functions. In fact, H. pylori is a paradigm of persistent infection, chronic inflammation and cellular destruction. In particular, H. pylori profoundly induces chromosomal DNA damage by introducing double-strand breaks (DSBs) followed by genomic instability. DSBs appear in response to oxidative stress and pro-inflammatory transcription during the S-phase of the epithelial cell cycle, which mainly depends on the presence of the bacterial cag pathogenicity island (cagPAI)-encoded type IV secretion system (T4SS). This scenario is closely connected with the T4SS-mediated injection of ADP-glycero-β-D-manno-heptose (ADP-heptose) and oncoprotein CagA. While ADP-heptose links transcription factor NF-κB-induced innate immune signaling with RNA-loop-mediated DNA replication stress and introduction of DSBs, intracellular CagA targets the tumor suppressor BRCA1. The latter scenario promotes BRCAness, a disease characterized by the deficiency of effective DSB repair. In addition, genetic studies of patients demonstrated the presence of gastric cancer-associated single nucleotide polymorphisms (SNPs) in immune-regulatory and other genes as well as specific pathogenic germline variants in several crucial genes involved in homologous recombination and DNA repair, all of which are connected to H. pylori infection. Here we review the molecular mechanisms leading to chromosomal DNA damage and specific genetic aberrations in the presence or absence of H. pylori infection, and discuss their importance in gastric carcinogenesis.

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.

Implications of reactive oxygen species in lung cancer and exploiting it for therapeutic interventions

Lung cancer is the second (11.4%) most commonly diagnosed cancer and the first (18%) to cause cancer-related deaths worldwide. The incidence of lung cancer varies significantly among men, women, and high and low-middle-income countries. Air pollution, inhalable agents, and tobacco smoking are a few of the critical factors that determine lung cancer incidence and mortality worldwide. Reactive oxygen species are known factors of lung carcinogenesis resulting from the xenobiotics and their mechanistic paths are under critical investigation. Reactive oxygen species exhibit dual roles in cells, as a tumorigenic and anti-proliferative factor, depending on spatiotemporal context. During the precancerous state, ROS promotes cancer origination through oxidative stress and base-pair substitution mutations in pro-oncogenes and tumor suppressor genes. At later stages of tumor progression, they help the cancer cells in invasion, and metastases by activating the NF-kB and MAPK pathways. However, at advanced stages, when ROS exceeds the threshold, it promotes cell cycle arrest and induces apoptosis in cancer cells. ROS activates extrinsic apoptosis through death receptors and intrinsic apoptosis through mitochondrial pathways. Moreover, ROS upregulates the expression of beclin-1 which is a critical component to initiate autophagy, another form of programmed cell death. ROS is additionally involved in an intermediatory step in necroptosis, which catalyzes and accelerates this form of cell death. Various therapeutic interventions have been attempted to exploit this cytotoxic potential of ROS to treat different cancers. Growing body of evidence suggests that ROS is also associated with chemoresistance and cancer cell immunity. Considering the multiple roles of ROS, this review highlights the exploitation of ROS for various therapeutic interventions. However, there are still gaps in the literature on the dual roles of ROS and the involvement of ROS in cancer cell immunity and therapy resistance.

Protective Effects of Naringin-Dextrin Nanoformula against Chemically Induced Hepatocellular Carcinoma in Wistar Rats: Roles of Oxidative Stress, Inflammation, Cell Apoptosis, and Proliferation

Nanotechnology holds great promise for the development of treatments for deadly human diseases, such as hepatocellular carcinoma (HCC). In the current study, we compared the hepatoprotective effects of naringin-dextrin nanoparticles (NDNPs) against HCC in male Wistar rats with those of pure naringin and investigated the underlying cellular and molecular mechanisms. HCC was induced by intraperitoneal injection of diethylnitrosamine (DEN, 150 mg/kg body weight (b.w.) per week) for two weeks, followed by oral administration of 2-acetylaminofluorene (2AAF, 20 mg/kg b.w.) four times per week for three weeks. DEN/2AAF-administered rats were divided into three groups that respectively received 1% carboxymethyl cellulose (as vehicle), 10 mg/kg b.w. naringin, or 10 mg/kg b.w. NDNP every other day by oral gavage for 24 weeks. Both naringin and NDNP significantly attenuated the harmful effects of DEN on liver function. Both compounds also suppressed tumorigenesis as indicated by the reduced serum concentrations of liver tumor markers, and this antitumor effect was confirmed by histopathological evaluation. Additionally, naringin and NDNP prevented DEN-induced changes in hepatic oxidative stress and antioxidant activities. In addition, naringin and NDNP suppressed inflammation induced by DEN. Moreover, naringin and NDNP significantly reduced the hepatic expression of Bcl-2 and increased Bax, p53, and PDCD5 expressions. Naringin and NDNP also reduced expression of IQGAP1, IQGAP3, Ras signaling, and Ki-67 while increasing expression of IQGAP2. Notably, NDNP more effectively mitigated oxidative stress and inflammatory signaling than free naringin and demonstrated improved antitumor efficacy, suggesting that this nanoformulation improves bioavailability within nascent tumor sites.

Cinnamon oil as a co-chemotherapy agent through inhibition of cell migration and MMP-9 expression on 4T1 cells

OBJECTIVES

The long-term and high-dose use of doxorubicin as chemotherapy for triple-negative breast cancer (TNBC) patients induces epithelial-to-mesenchymal transition (EMT) and stimulates cancer metastasis. Cinnamaldehyde is a major compound of cinnamon oil (CO) suppressing Snail and NFκB activity that are involved in cell migration. This study aims to explore the activity of CO as a co-chemotherapeutic agent on 4T1 breast cancer cells.

METHODS

The CO was obtained by water and steam distillation and was characterized phytochemically by gas chromatography-mass spectrometry (GC-MS). Cytotoxic activity of single CO or in combination with doxorubicin was observed by MTT assay. Cell migration and MMP-9 expression were measured by scratch wound healing and gelatin zymography assays. The intracellular reactive oxygen species (ROS) levels were observed by 2',7'-dichlorofluorescin diacetate (DCFDA) staining flowcytometry.

RESULTS

The phytochemical analysis with GC-MS showed that CO contains 14 compounds with cinnamaldehyde as the major compound. CO exhibited cytotoxicity on 4T1 cells with the IC₅₀ value of 25 μg/mL and its combination with doxorubicin decreased cell viability and inhibited cell migration compared to a single use. Furthermore, the combination of CO and doxorubicin inhibited MMP-9 expression and elevated intracellular ROS levels compared to control.

CONCLUSIONS

CO has the potential to be developed as a co-chemotherapy agent through inhibition of cell migration, and intracellular ROS levels elevation.

Targeting selenoprotein H in the nucleolus suppresses tumors and metastases by Isovalerylspiramycin I

Background

Compared to normal cells, cancer cells exhibit a higher level of oxidative stress, which primes key cellular and metabolic pathways and thereby increases their resilience under oxidative stress. This higher level of oxidative stress also can be exploited to kill tumor cells while leaving normal cells intact. In this study we have found that isovalerylspiramycin I (ISP I), a novel macrolide antibiotic, suppresses cancer cell growth and tumor metastases by targeting the nucleolar protein selenoprotein H (SELH), which plays critical roles in keeping redox homeostasis and genome stability in cancer cells.

Methods

We developed ISP I through genetic recombination and tested the antitumor effects using primary and metastatic cancer models. The drug target was identified using the drug affinity responsive target stability (DARTS) and mass spectrum assays. The effects of ISP I were assessed for reactive oxygen species (ROS) generation, DNA damage, R-loop formation and its impact on the JNK2/TIF-IA/RNA polymerase I (POLI) transcription pathway.

Results

ISP I suppresses cancer cell growth and tumor metastases by targeting SELH. Suppression of SELH induces accumulation of ROS and cancer cell-specific genomic instability. The accumulation of ROS in the nucleolus triggers nucleolar stress and blocks ribosomal RNA transcription via the JNK2/TIF-IA/POLI pathway, causing cell cycle arrest and apoptosis in cancer cells.

Conclusions

We demonstrated that ISP I links cancer cell vulnerability to oxidative stress and RNA biogenesis by targeting SELH. This suggests a potential new cancer treatment paradigm, in which the primary therapeutic agent has minimal side-effects and hence may be useful for long-term cancer chemoprevention.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-022-02350-0.

Celastrol elicits antitumor effects by inhibiting the STAT3 pathway through ROS accumulation in non-small cell lung cancer

Background

Non-small cell lung cancer (NSCLC) is the most common lung cancer with high mortality across the world, but it is challenging to develop an effective therapy for NSCLC. Celastrol is a natural bioactive compound, which has been found to possess potential antitumor activity. However, the underlying molecular mechanisms of celastrol activity in NSCLC remain elusive.

Methods

Cellular function assays were performed to study the suppressive role of celastrol in human NSCLC cells (H460, PC-9, and H520) and human bronchial epithelial cells BEAS-2B. Cell apoptosis levels were analyzed by flow cytometry, Hoechst 33342, caspase-3 activity analysis, and western blot analysis. Intracellular reactive oxygen species (ROS) were analyzed by flow cytometry and fluorescence microscope. Expression levels of endoplasmic reticulum (ER) stress-related proteins and phosphorylated signal transducer and activator of transcription 3 (P-STAT3) were identified via western blot analysis. A heterograft model in nude mice was employed to evaluate the effect of celastrol in vivo.

Results

Celastrol suppressed the growth, proliferation, and metastasis of NSCLC cells. Celastrol significantly increased the level of intracellular ROS; thus, triggering the activation of the ER stress pathway and inhibition of the P-STAT3 pathway, and eventually leading to cell apoptosis, and the effects were reversed by the pre-treatment with N-Acetyl-l-cysteine (NAC). Celastrol also suppressed tumor growth in vivo.

Conclusion

The outcomes revealed that celastrol plays a potent suppressive role in NSCLC in vitro and in vivo. Celastrol induces apoptosis via causing mitochondrial ROS accumulation to suppress the STAT3 pathway. Celastrol may have potential application prospects in the therapy of NSCLC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-022-03741-9.

Redox balance and autophagy regulation in cancer progression and their therapeutic perspective

Cellular ROS production participates in various cellular functions but its accumulation decides the cell fate. Malignant cells have higher levels of ROS and active antioxidant machinery, a characteristic hallmark of cancer with an outcome of activation of stress-induced pathways like autophagy. Autophagy is an intracellular catabolic process that produces alternative raw materials to meet the energy demand of cells and is influenced by the cellular redox state thus playing a definite role in cancer cell fate. Since damaged mitochondria are the main source of ROS in the cell, however, cancer cells remove them by upregulating the process of mitophagy which is known to play a decisive role in tumorigenesis and tumor progression. Chemotherapy exploits cell machinery which results in the accumulation of toxic levels of ROS in cells resulting in cell death by activating either of the pathways like apoptosis, necrosis, ferroptosis or autophagy in them. So understanding these redox and autophagy regulations offers a promising method to design and develop new cancer therapies that can be very effective and durable for years. This review will give a summary of the current therapeutic molecules targeting redox regulation and autophagy for the treatment of cancer. Further, it will highlight various challenges in developing anticancer agents due to autophagy and ROS regulation in the cell and insights into the development of future therapies.

Integrated analysis of transcriptomics, proteomics and metabolomics data reveals the role of SLC39A1 in renal cell carcinoma

Purpose: Accumulating evidence suggests that solute carrier family 39 member 1 (SLC39A1) conceivably function as a tumor suppressor, but the underlying mechanism in renal cell carcinoma (RCC) is poorly understood. Methods: OSRC-2 renal cancer cells were first transfected with SLC39A1 overexpressed vectors and empty vectors and then used in transcriptomics, proteomics, and metabolomics integrated analyses. Results: SLC39A1 significantly altered several metabolisms at transcriptional, protein and metabolic levels, including purine and pyrimidine metabolism, amino acids and derivatives metabolism, lactose metabolism, and free fatty acid metabolism. Additionally, SLC39A1 could promote ferroptosis, and triggered significant crosstalk in PI3K-AKT signal pathway, cAMP signal pathway, and peroxisome proliferators-activated receptor (PPAR) signal pathway. Conclusion: We found SLC39A1 transfection impaired tumor metabolism and perturbed tumor metabolism-related pathways, which was a likely cause of the alteration in cell proliferation, migration, and cell cycle progression in RCC cells. These multi-omics analyses results provided both a macroscopic picture of molecular perturbation by SLC39A1 and novel insights into RCC tumorigenesis and development.

NK cells and solid tumors: therapeutic potential and persisting obstacles

Natural killer (NK) cells, which are innate lymphocytes endowed with potent cytotoxic activity, have recently attracted attention as potential anticancer therapeutics. While NK cells mediate encouraging responses in patients with leukemia, the therapeutic effects of NK cell infusion in patients with solid tumors are limited. Preclinical and clinical data suggest that the efficacy of NK cell infusion against solid malignancies is hampered by several factors including inadequate tumor infiltration and persistence/activation in the tumor microenvironment (TME). A number of metabolic features of the TME including hypoxia as well as elevated levels of adenosine, reactive oxygen species, and prostaglandins negatively affect NK cell activity. Moreover, cancer-associated fibroblasts, tumor-associated macrophages, myeloid-derived suppressor cells, and regulatory T cells actively suppress NK cell-dependent anticancer immunity. Here, we review the metabolic and cellular barriers that inhibit NK cells in solid neoplasms as we discuss potential strategies to circumvent such obstacles towards superior therapeutic activity.

The Self-Administered Use of Complementary and Alternative Medicine (CAM) Supplements and Antioxidants in Cancer Therapy and the Critical Role of Nrf-2-A Systematic Review

Complementary and alternative medicine (CAM) supplements are widely used by cancer patients. Dietary supplements, vitamins and minerals, herbal remedies, and antioxidants are especially popular. In a systematic literature review, 37 studies, each including more than 1000 participants, on CAM, dietary supplement, and vitamin use among cancer patients were identified. Accordingly, cancer patients use antioxidants such as vitamin C (from 2.6% (United Kingdom) to 41.6% (United States)) and vitamin E (from 2.9% (China) to 48% (United States)). Dietary supplements and vitamins are taken for different reasons, but often during conventional cancer treatment involving chemotherapy or radiotherapy and in a self-decided manner without seeking medical advice from healthcare professionals. Drug-drug interactions with dietary supplements or vitamins involving multiple signaling pathways are well described. Since most of the anticancer drugs generate reactive oxygen species (ROS), an adaptive stress response of healthy and malignant cells, mainly driven by the Nrf-2-Keap I network, can be observed. On the one hand, healthy cells should be protected from ROS-overproducing chemotherapy and radiotherapy; on the other hand, ROS production in cancer cells is a "desirable side effect" during anticancer drug treatment. We here describe the paradoxical use of antioxidants and supplements during cancer therapy, possible interactions with anticancer drugs, and the involvement of the Nrf-2 transcription factor.

Glutamine metabolism in cancers: Targeting the oxidative homeostasis

Glutamine is the most abundant amino acid in blood and tissues, and the most important nutrient except for glucose in cancer cells. Over the past years, most studies have focused on the role of Gln metabolism in supporting energy metabolism rather than maintaining oxidative homeostasis. In fact, Gln is an important factor in maintaining oxidative homeostasis of cancer cells, especially in “Glutamine addicted” cancer cells. Here, this paper will review the recent scientific literature about the link between Gln metabolism and oxidative homeostasis, with an emphasis on the potential role of Gln metabolism in different cancers. Given that oxidative homeostasis is of critical importance in cancer, understanding the impacts of a Gln metabolism on oxidative homeostasis, gaining great insights into underlying molecular mechanisms, and developing effective therapeutic strategies are of great importance.

Dracocephalum kotschyi Boiss. In Vitro Efficacy on Growth and Apoptosis Induction in Leishmania major Promastigotes

Dracocephalum kotschyi Boiss. is a plant generally used in modern medicine to treat many human illnesses. It is also used to prevent tumor cell proliferation throughout the world. This study's objective was to evaluate this plant's in vitro efficacy on growth and apoptosis induction in Leishmania major promastigotes. To do this, the essential oil is extracted for the test following the collection and identification of D. kotschyi. The essential oil was analyzed using a GC-MS analyzer. Promastigotes of L. major were cultured in RPMI-1640 media, and the MTT assay and a flow cytometry analysis were carried out on promastigotes that had entered the log phase. To differentiate between viable, necrotic, and apoptotic treated or untreated promastigotes, the flow cytometry method of double staining with annexin V-FLUOS and propidium iodide (PI) was used. Given the results obtained, 11 phytochemicals were identified in the essential oil of this plant. Copaene (22.15%), methyl geranate (16.31%), geranial (13.78%), and carvone (11.34%) were the main substances. The essential oil of D. kotschyi inhibits the proliferation of L. major promastigotes at 921 μg/mL, 252 μg/mL, and 416 μg/mL, respectively, after 24 h, 48 h, and 78 h. The cells were divided into four quadrates based on cell phases using the flow cytometry approach by double staining with annexin V-FLUOS and propidium iodide (PI): necrosis (Q1), late apoptosis (Q2), early apoptosis (Q3), and viable (Q4) quadrates. Overall, it is apparent that the different concentrations induced cell apoptosis in promastigotes. Observation under the light microscope at ×100 magnification showed that the different doses of D. kotschyi essential oil caused apparent alterations in the treated promastigotes. In this work, D. kotschyi essential oils induce programmed death on L. major promastigotes. This study opens many research perspectives, such as investigating the mechanisms of action and the production of a phytomedicine based on this plant.

Evaluation of Paraoxonase-1 and Pentraxin-3 in the Diagnosis and Prognosis of Endometrial Cancer

It is relevant to find new prognostic and diagnostic biomarkers for endometrial cancer. The study group consisted of 94 cases of endometrial cancer, the control group of 65 cases of normal endometrium. We evaluated PON1 and PTX3 serum levels. The ROC curve was plotted. The area under the curve was calculated to characterize the sensitivity and specificity of the studied parameters. Univariate and multivariate analyses were performed simultaneously using the Cox regression model. The Kaplan-Meier curve was used to assess survival. The cut-off level of PON1 was 142.6 ng/mL, with a sensitivity and specificity of 79 and 84% (p = 0.0321). The cut-off level of PTX3 was 4.2 ng/mL, with a sensitivity and specificity of 63 and 57% (p = 0.028). The favorable prognostic factor determined in serum was PON1 (for PFS: HR 0.93, 95% CI 0.86-1.03, p = 0.046; for OS: HR 0.96, 95% CI 0.89-1.08, p = 0.009). PON1 may be considered a potential biomarker in the diagnosis of endometrial cancer. Considering multivariate analysis, the PON1 serum level above the median is an independent favourable prognostic factor affecting PFS and OS. Considering Kaplan-Meier curves, longer recurrence-free survival and overall survival were found in patients with PON1 levels below the median. In view of the inconclusive results, we suggest that further studies should be conducted.

Mitochondrial Matrix Protease ClpP Agonists Inhibit Cancer Stem Cell Function in Breast Cancer Cells by Disrupting Mitochondrial Homeostasis

Mitochondria are multifaceted organelles which are important for bioenergetics, biosynthesis and signaling in metazoans. Mitochondrial functions are frequently altered in cancer to promote both the energy and the necessary metabolic intermediates for biosynthesis required for tumor growth. Cancer stem cells (CSCs) contribute to chemotherapy resistance, relapse, and metastasis. Recent studies have shown that while non-stem, bulk cancer cells utilize glycolysis, breast CSCs are more dependent on oxidative phosphorylation (OxPhos) and therefore targeting mitochondria may inhibit CSC function. We previously reported that small molecule ONC201, which is an agonist for the mitochondrial caseinolytic protease (ClpP), induces mitochondrial dysfunction in breast cancer cells. In this study, we report that ClpP agonists inhibit breast cancer cell proliferation and CSC function in vitro and in vivo. Mechanistically, we found that OxPhos inhibition downregulates multiple pathways required for CSC function, such as the mevalonate pathway, YAP, Myc, and the HIF pathway. ClpP agonists showed significantly greater inhibitory effect on CSC functions compared with other mitochondria-targeting drugs. Further studies showed that ClpP agonists deplete NAD(P)+ and NAD(P)H, induce redox imbalance, dysregulate one-carbon metabolism and proline biosynthesis. Downregulation of these pathways by ClpP agonists further contribute to the inhibition of CSC function. In conclusion, ClpP agonists inhibit breast CSC functions by disrupting mitochondrial homeostasis in breast cancer cells and inhibiting multiple pathways critical to CSC function.

Significance

ClpP agonists disrupt mitochondrial homeostasis by activating mitochondrial matrix protease ClpP. We report that ClpP agonists inhibit cell growth and cancer stem cell functions in breast cancer models by modulating multiple metabolic pathways essential to cancer stem cell function.

ISCA2 deficiency leads to heme synthesis defects and impaired erythroid differentiation in K562 cells by indirect ROS-mediated IRP1 activation

Iron‑sulfur (Fe-S) clusters have been shown to play important roles in various cellular physiological process. Iron‑sulfur cluster assembly 2 (ISCA2) is a vital component of the [4Fe-4S] cluster assembly machine. Several studies have shown that ISCA2 is highly expressed during erythroid differentiation. However, the role and specific regulatory mechanisms of ISCA2 in erythroid differentiation and erythroid cell growth remain unclear. RNA interference was used to deplete ISCA2 expression in human erythroid leukemia K562 cells. The proliferation, apoptosis, and erythroid differentiation ability of the cells were assessed. We show that knockdown of ISCA2 has profound effects on [4Fe-4S] cluster formation, diminishing mitochondrial respiratory chain complexes, leading to reactive oxygen species (ROS) accumulation and mitochondrial damage, inhibiting cell proliferation. Excessive ROS can inhibit the activity of cytoplasmic aconitase (ACO1) and promote ACO1, a bifunctional protein, to perform its iron-regulating protein 1(IRP1) function, thus inhibiting the expression of 5'-aminolevulinate synthase 2 (ALAS2), which is a key enzyme in heme synthesis. Deficiency of ISCA2 results in the accumulation of iron divalent. In addition, the combination of excessive ferrous iron and ROS may lead to damage of the ACO1 cluster and higher IRP1 function. In brief, ISCA2 deficiency inhibits heme synthesis and erythroid differentiation by double indirect downregulation of ALAS2 expression. We conclude that ISCA2 is essential for normal functioning of mitochondria, and is necessary for erythroid differentiation and cell proliferation.

Cordyceps militaris Carotenoids Protect Human Retinal Endothelial Cells against the Oxidative Injury and Apoptosis Resulting from H2O2

Vision loss is primarily caused by age-related macular degeneration (AMD) due to oxidative retinal pigment epithelial (RPE) cell injury. Carotenoid utilization is deemed a possible strategy for treating AMD. Cordyceps militaris has advantages like immunomodulatory, anti-inflammatory, and antioxidative characteristics. This paper assessed the possible protective influence of carotenoids obtained by isolating and purifying the Cordyceps militaris (CMCT) into human RPE cells (ARPE-19) damaged by hydrogen peroxide (H₂O₂). The findings demonstrated that CMCT safeguarded the ARPE-19 cells against the damage and apoptosis caused by H₂O₂ and oxidative stress via Bcl-2 protein upregulation, as well as the expression of Bax and cleaved caspase-3 protein. In addition, CMCT treatment increased cell survival and restricted the generation of H₂O₂-induced reactive oxygen species (ROS) and the protein expression of NADPH oxidase-1 (NOX1). Additionally, the CMCT treatment of H₂O₂-induced ARPE-19 cells ameliorated high malondialdehyde (MDA) levels in oxidative stress-induced cells. The catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH) returned to standard levels, which were governed by the higher expression of nuclear Nrf2 protein in the ARPE-19 cells. Moreover, this study showed that CMCT safeguarded the ARPE-19 cells against the damage caused by oxidative stress via its antioxidant activity and antiapoptotic functionality, suggesting the potential therapeutic role of CMCT in AMD prevention and mitigation.