Reactive Oxygen Species Inhibitor N-acetylcysteine Research Articles

Nortriptyline hydrochloride, a potential candidate for drug repurposing, inhibits gastric cancer by inducing oxidative stress by triggering the Keap1-Nrf2 pathway

Effective drugs for the treatment of gastric cancer (GC) are still lacking. Nortriptyline Hydrochloride (NTP), a commonly used antidepressant medication, has been demonstrated by numerous studies to have antitumor effects. This study first validated the ability of NTP to inhibit GC and preliminarily explored its underlying mechanism. To begin with, NTP inhibits the activity of AGS and HGC27 cells (Human-derived GC cells) in a dose-dependent manner, as well as proliferation, cell cycle, and migration. Moreover, NTP induces cell apoptosis by upregulating BAX, BAD, and c-PARP and downregulating PARP and Bcl-2 expression. Furthermore, the mechanism of cell death caused by NTP is closely related to oxidative stress. NTP increases intracellular reactive oxygen species (ROS) and malondialdehyde (MDA) levels, decreasing the mitochondrial membrane potential (MMP) and inducing glucose (GSH) consumption. While the death of GC cells can be partially rescued by ROS inhibitor N-acetylcysteine (NAC). Mechanistically, NTP activates the Kelch-like ECH-associated protein (Keap1)—NF-E2-related factor 2 (Nrf2) pathway, which is an important pathway involved in oxidative stress. RNA sequencing and proteomics analysis further revealed molecular changes at the mRNA and protein levels and provided potential targets and pathways through differential gene expression analysis. In addition, NTP can inhibited tumor growth in nude mouse subcutaneous tumor models constructed respectively using AGS and MFC (mouse-derived GC cells), providing preliminary evidence of its effectiveness in vivo. In conclusion, our study demonstrated that NTP exhibits significant anti-GC activity and is anticipated to be a candidate for drug repurposing.

Inhibition of NRF2 enhances the acute myeloid leukemia cell death induced by venetoclax via the ferroptosis pathway

Venetoclax, an inhibitor that selectively targets B cell lymphoma-2 (BCL-2) that has been approved for treating adult acute myeloid leukemia (AML) in combination with hypomethylating agents. However, its short duration of response and emergence of resistance are significant issues. In this study, we found that the sensitivity of AML cells to venetoclax was considerably enhanced by ML385, an inhibitor of the ferroptosis factor nuclear transcription factor erythroid 2-related factor 2 (NRF2). Using AML samples, we verified that NRF2 and its target gene ferritin heavy chain 1 (FTH1) were highly expressed in patients with AML and correlated with poor prognosis. Downregulation of NRF2 could inhibit FTH1 expression and significantly enhance the venetoclax-induced labile iron pool and lipid peroxidation. By contrast, NRF2 overexpression or administration of the reactive oxygen species inhibitor N-acetylcysteine and vitamin E could effectively suppress the anti-AML effects of ML385+venetoclax. Furthermore, the ferroptosis inducer erastin increased the anti-AML effects of venetoclax. Our study demonstrated that NRF2 inhibition could enhance the AML cell death induced by venetoclax via the ferroptosis pathway. Thus, the combination of ML385 with venetoclax may offer a favorable strategy for AML treatment.

Verteporfin suppressed mitophagy via PINK1/parkin pathway in endometrial cancer.

Endometrial cancer (EC) is a malignancy that poses a threat to woman's health worldwide. Building upon prior work, we explored the inhibitory effect of verteporfin on EC. We showed that verteporfin can damage the mitochondria of EC cells, leading to a decrease of mitochondrial membrane potential and an increase in ROS (reactive oxygen species). In addition, verteporfin treatment was shown to inhibit the proliferation and migration of EC cells, promote apoptosis, and reduce the expression of mitophagy-related proteins PINK1/parkin and TOM20. The ROS inhibitor N-Acetyl Cysteine was able to rescue the expression of PINK1/parkin proteins. This suggests that verteporfin may inhibit mitophagy by elevating ROS levels, thereby inhibiting EC cell viability. The effect of verteporfin on mitophagy supports further investigation as a potential therapeutic option for EC.

Echinococcus granulosus cyst fluid inhibits the type I interferon response by promoting ROS in macrophages

In cystic echinococcosis (CE), Echinococcus granulosus cystic fluid (EgCF) could impede macrophage-mediated immunity. However, whether EgCF is implicated in the type I interferon response remains to be established. Here, we revealed that EgCF reduced 2′3′-cGAMP-induced IFN-β production in macrophages by inhibiting the cGAS-STING-IRF3 signaling. EgCF also increased the intracellular reactive oxygen species (ROS) levels. Administration of the ROS inhibitor N-acetylcysteine (NAC) restored the cGAS-STING-IRF3 signaling, which, in turn, upregulated IFN-β expression. The findings disclose that EgCF could increase macrophage ROS levels, thereby blocking cGAS-STING-IRF3 signaling and repressing the IFN-I response.

Induction of mitophagy via ROS-dependent pathway protects copper-induced hypothalamic nerve cell injury

Copper (Cu) is one of the essential trace elements in the body, but excessive amounts of Cu harm multiple organs and tissues such as liver, kidneys, testis, ovaries, and brain. However, the mechanism of hypothalamic neurotoxicity induced by Cu is still unknown. This study examined the relationship between reactive oxygen species (ROS) and mitophagy in mouse hypothalamus treated with high Cu. The results demonstrated that high levels of copper sulfate (CuSO4) could cause histopathological and neuronal changes in the mouse hypothalamus, produce a large amount of ROS, induce mitophagy, and lead to an imbalance of mitochondrial fusion/fission. The main manifestations are an increase in the expression levels of LC3-II/LC3-I, p62, DRP1, and FIS1, and a decrease in the expression levels of MFN1 and MFN2. Cu can induce mitophagy also was confirmed by LC3 co-localization with TOMM20 (mitochondrial marker). Next, the effect of oxidative stress on CuSO4-induced mitophagy was demonstrated. The results showed that ROS inhibitor N-acetylcysteine (NAC) diminished CuSO4-induced mitophagy and reversed the disturbance of mitochondrial dynamics. Additionally, a study was carried out to evaluate the role of mitophagy in CuSO4-induced hypothalamic injury. The inhibition of mitophagy using mitophagy inhibitor (Mdivi-1) decreased cell viability and promoted CuSO4-inhibited mitochondrial fusion. The aforementioned results suggested that CuSO4 induced mitophagy via oxidative stress in N38 cells and mouse hypothalamus, and that the activation of mitophagy might generate protective mechanisms by alleviating Cu-induced mitochondrial dynamics disorder. This study provided a novel approach and theoretical basis for studying and preventing Cu neurotoxicity.

Cucurbitacin B induces apoptosis in colorectal cells through reactive oxygen species generation and endoplasmic reticulum stress pathways.

Cucurbitacin B (CuB) is a member of the cucurbitacin family, which has shown potent anticancer pharmacological activity. Prolonged or severe endoplasmic reticulum stress (ERS) induces apoptosis; therefore, the present study investigated whether CuB may activate the ERS pathway to induce apoptosis. HT-29 and SW620 colorectal cancer (CRC) cells were treated with a range of concentrations of CuB for 48 h, and the viability and proliferation of cells were determined using Cell Counting Kit 8 (CCK8) and colony formation assays. Subsequently, the appropriate CuB concentration (5 µM) was selected for treatment of CRC cells for 48 h. Western blot analysis was used to measure the expression levels of ERS-related proteins, flow cytometry was used to evaluate apoptosis, the dichlorodihydrofluorescein diacetate fluorescent probe was used to detect reactive oxygen species (ROS) production, and the relationship between ROS and ERS was determined by western blot analysis. Furthermore, flow cytometry was used to evaluate apoptosis after treatment with the ERS inhibitor 4-phenylbutyric acid, the ROS inhibitor N-acetylcysteine and following knockdown of CHOP expression. In addition, western blot analysis was performed to measure Bax and Bcl2 protein expression levels, and a CCK8 assay was performed to evaluate the viability of cells following knockdown of CHOP. Notably, CuB treatment increased apoptosis and inhibited cell proliferation in CRC cell lines, and these effects were mediated by ROS and ROS-regulated activation of the PERK and XBP1 ERS pathways. In conclusion, CuB may induce apoptosis in HT-29 and SW620 CRC cells via ROS and ERS.

PI3K/mTOR inhibitor VS-5584 combined with PLK1 inhibitor exhibits synergistic anti-cancer effects on non-small cell lung cancer

Small molecule drugs are of significant importance in the treatment of non-small cell lung cancer (NSCLC). Here, we explored biological effects of the PI3K/mTOR inhibitor VS-5584 on NSCLC. Our findings indicated that VS-5584 administration resulted in a dose-dependent inhibition of NSCLC cell proliferation, as well as the induction of apoptosis and cycle arrest. Additionally, we observed a significant increase in intracellular reactive oxygen species (ROS) levels following VS-5584 treatment. The use of the ROS inhibitor N-acetylcysteine (NAC) effectively reduced ROS levels and decreased the proportion of apoptotic cells. Treatment with VS-5584 led to an upregulation of genes associated with apoptosis and cell cycle, such as c-caspase 3 and P21. Conversely, a downregulation of cyclin-dependent kinase 1 (CDK1) expression was observed. Next, transcriptome analyses revealed that VS-5584 treatment altered the abundance of 1520 genes/transcripts in PC-9 cells, one of which was polo-like kinase 1 (PLK1). These differentially expressed genes were primarily enriched in biological processes such as cell cycle regulation and cell apoptosis, which are closely linked to the P53 and apoptosis pathways. Co-treatment with VS-5584 and PLK1 inhibitor NMS-P937 resulted in enhanced cancer cell death, exhibiting synergistic inhibitory activity. Notably, VS-5584 inhibited the growth of NSCLC in a patient-derived xenograft (PDX) mouse model without observable abnormalities in major organs. Overall, VS-5584 effectively suppressed the growth of NSCLC cells both in vitro and in vivo. VS-5584 combined with NMS-P937 exhibited a synergistic effect in inhibiting NSCLC cell growth. These findings suggest that VS-5584 has potential as a therapeutic strategy for treating NSCLC.

LINC00938 alleviates hypoxia ischemia encephalopathy induced neonatal brain injury by regulating oxidative stress and inhibiting JNK/p38 MAPK signaling pathway

Hypoxic-ischemic encephalopathy (HIE) is an important factor leading to permanent damage of central nervous system (CNS) and even neonatal death. Long non-coding RNAs (lncRNAs) has been shown to get involved in the pathogenesis of nervous system diseases. LINC00938 is an intergenic lncRNA which is reported to be involved in neurodegenerative disease. However, the potential role of LINC00938 in nerve injury of neonatal HIE is undetermined. Here, we found that the expression of LINC00938 in the whole blood of neonates with HIE was downregulated compared with the non-HIE group. Functional study revealed that the expression of LINC00938 was significantly decreased in oxygen-glucose deprivation (OGD)-induced SH-SY5Y. Knockdown of LINC00938 induced the neural cell apoptosis by increased the protein level of Bax, Cleaved-Caspase3 and decreased the expression of Bcl-2. In addition, overexpression of LINC00938 prevented the apoptosis of SH-SY5Y from OGD injury. RNA-seq analysis showed that MAPK signaling was involved in the anti-apoptosis function of LINC00938. LINC00938 knockdown induced the activation of c-Jun-N-terminal kinase (JNK), p38 mitogen-activated protein kinase, and inhibited the activation of ERK signaling. However, LINC00938 play neuroprotective role in OGD-induced SH-SY5Y by suppression the phosphorylation of JNK and p38 MAPK rather than regulation of ERK signaling pathway. Further analyses illustrated that the cell apoptosis of neuronal cell was dependent on the elevation of reactive oxygen species (ROS) and result in mitochondria dysfunction in LINC00938 knockdown SH-SY5Y. Pretreated with ROS inhibitor N-acetylcysteine amide (NACA) dramatically suppressed LINC00938 knockdown induced oxidative stress and mitochondria dysfunction which induced cell apoptosis. In addition, NACA treatment significantly reduced the expression of p-JNK and p-p38 in OGD-induced SH-SY5Y. Furthermore, overexpression of LINC00938 displayed a notably neuroprotective effect by suppress central nervous system cell apoptosis via alleviating oxidative stress in CoCl2-induced hypoxic HIE model of zebrafish. Taken together, these results suggested that LINC00938 can act as a neuroprotective factor to inhibit oxidative stress and apoptosis of CNS under HIE conditions.

Crebanine induces ROS-dependent apoptosis in human hepatocellular carcinoma cells via the AKT/FoxO3a signaling pathway.

Background: Hepatocellular carcinoma (HCC), as an aggressive cancer with a high mortality rate, needs high-efficiency and low-toxicity drug therapy. Natural products have great potential as candidate lead compounds for the development of new HCC drugs. Crebanine is an isoquinoline alkaloid derived from Stephania with various potential pharmacological effects such as anti-cancer. However, the molecular mechanism underlying crebanine-induced liver cancer cells apoptosis has not been reported. Here, we investigated the effect of crebanine on HCC and identified a potential mechanism of action. Methods: In this paper, we intend to detect the toxic effects of crebanine on hepatocellular carcinoma HepG2 cells through a series of in vitro experiments, including detecting the effects of crebanine on the proliferation of HepG2 cells using the CCK8 method and plate cloning assay, observing the growth status and morphological changes of crebanine on HepG2 cells by inverted microscopy; and using the Transwell method to determine the the effect of crebanine on the migration and invasion ability of HepG2 cells; using Hoechst 33258 assay to stain cancer cells, thus observing the effect of crebanine on the morphology of HepG2 apoptotic cells, and detecting the apoptotic state and level of HepG2 cells by flow cytometry; using ROS kit and JC-1 assay kit to detect the changes of reactive oxygen species and mitochondrial membrane potential of HepG2 The immunofluorescence assay was taken to verify whether crebanine had an effect on the expression of p-FoxO3a in cancer cells; the Wetern blot assay was also used to examine the effect of crebanine on proteins related to the mitochondrial apoptotic pathway and its effect on the regulation of the relative protein expression of AKT/FoxO3a axis; after this, NAC and AKT inhibitor LY294002 were used to cells were pretreated with NAC and AKT inhibitor LY294002, respectively, in order to further validate the inhibitory effect of crebanine. Results: It was shown that crebanine effectively inhibited the growth and capacity of HepG2 cells migration and invasion in a dose-dependent manner. Furthermore, the effect of crebanine on the morphology of HepG2 cells was observed through microscopy. Meanwhile, crebanine induced apoptosis by causing reactive oxygen species (ROS) burst and mitochondrial membrane potential (MMP) disrupt. We found that crebanine could down-regulate Bcl-2 and up-regulate Bax, cleaved-PARP, cleaved-caspase-3 and cleaved-caspase-9, but these effects were overturned by ROS inhibitor N-acetylcysteine (NAC). Crebanine also down-regulated p-AKT and p-FoxO3a, and the PI3K inhibitor LY294002 significantly enhances this effect. We also found that the expression of AKT/FoxO3a signaling pathway was ROS-dependent. As shown by Western blots, NAC could partially attenuate the inhibitory effect of crebanine on AKT and FoxO3a phosphorylation. Conclusion: Based on our results, our results suggest that crebanine, as a compound with potential anticancer activity, has significant cytotoxic effects on hepatocellular carcinoma,and it likely induces apoptosis via ROS in the mitochondrial pathway and simultaneously affects the biological function of HCC via the ROS-AKT-FoxO3a signaling axis.

Shikonin potentiates therapeutic efficacy of oxaliplatin through reactive oxygen species-mediated intrinsic apoptosis and endoplasmic reticulum stress in oxaliplatin-resistant colorectal cancer cells.

Oxaliplatin (OXA) has been recognized as a third-generation platinum-based chemotherapeutic agent with stellar therapeutic efficacy in managing colorectal cancer (CRC). Nevertheless, resistance to OXA in CRC patients hinders its effectiveness. Shikonin (SHI), a natural naphthoquinone derived from Arnebia euchroma (Royle) Johnst., features a broad pharmacological profile and minimal toxicities. To assess the synergism of SHI andOXAtowards OXA-resistant CRC cells (HCT116R ), we employed in vitro and in vivo pharmacological assays. Our experiments provided evidence that SHI, either alone or in combination with OXA, considerably reduced cell proliferation, triggered apoptosis, and induced the generation of reactive oxygen species (ROS) in HCT116R cells. Furthermore, the combination of SHI and OXA dramatically curbed the extent of HCT116R -initiated xenograft growth in mouse models. Bioinformatics, western blot, and ROS assays highlighted that the mechanisms of SHI against OXA-resistant CRC cells may involve the induction of cellular responses to chemical stress, intrinsic apoptosis, as well as endoplasmic reticulum stress pathways mediated by ROS. Notably, the synergism of SHI+OXA was partially abrogated by an ROS inhibitor N-acetyl cysteine. Our findings imply the potential of SHI to boost the sensitivity of OXA to CRC, offering promising benefits for clinical strategies to combat OXA resistance.

NADPH oxidase 4 regulate the glycolytic metabolic reprogramming of microglial cells to promote M1 polarization.

This work aimed to investigate the role and mechanism of NADPH oxidase 4 (NOX4) in the polarization of microglial cells.Microglial cells were transfected with the NOX4 overexpression plasmid (pGL3-NOX4), and later treated with lipopolysaccharide (LPS) and interferon-γ (IFN-γ) to induce its M1 polarization. Later, the F4/80 + CD86 + cell proportion was detected by flow cytometry (FCM), the inflammatory factor expression levels were analyzed through enzyme-linked immunosorbent assay (ELISA), while ionized calcium binding adapter molecule 1(IBA-1) and PKM2 expression were measured by immunofluorescence (IF) staining. In addition, dichlorodihydrofluorescein diacetate probe was utilized to detect the reactive oxygen species(ROS) levels, glucose uptake, and glycolysis, as well as lactic acid level. The expression of glycolytic enzymes PKM2, HK2, and citrate (Si)-synthas(CS) was detected by Western-blot (WB) assay. Moreover, the polarization level of microglial cells was detected after ROS expression was suppressed by the ROS inhibitor N-acetylcysteine (NAC). In mouse experiments, LPS was applied in inducing central neuroinflammation in NOX4 knockdown mouse model (KO) and wild-type mice (WT). Thereafter, the inflammatory factor levels and lactic acid level in mouse tissues were detected; IBA-1 and CD86 expression in mice was measured by IF staining; and the expression of glycolytic enzymes PKM2, HK2, and CS in the central nervous system (CNS) was also detected.After NOX4 overexpression in microglial cells, the M1 polarization level was upregulated, the F4/80 + CD86 + cell proportion increased, and inflammatory factors were upregulated. At the same time, the expression of glycolytic enzymes PKM2, HK2, and CS was upregulated. NAC pretreatment suppressed the effects of NOX4, reduced the F4/80 + CD86 + cell proportion, and suppressed the expression of PKM2, HK2, and CS. In the mouse model, the expression levels of CD86 in KO group decreased, and the inflammatory factors were also downregulated.NOX4 promotes glycolysis of microglial cells via ROS, thus accelerating M1 polarization and inflammatory factor expression. In this regard, NOX4 is promising as a new target for the treatment of neuroinflammation.

Analysis of SOD1 variants in Chinese patients with familial amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease, and genetic contributors exert a significant role in the complicated pathogenesis. Identification of the genetic causes in ALS families could be valuable for early diagnosis and management. The development of potential drugs for patients with genetic defects will shed new light on ALS therapy. To identify causative variants in three Chinese families with familial ALS (FALS), reveal the pathogenic mechanism and look for the targeted drug for ALS. Whole-exome sequencing and bioinformatics were used to perform genetic analysis of the ALS families. Functional analysis was performed to study the variants' function and search for potential drug targets. Three heterozygous missense variants of the superoxide dismutase 1 gene (SOD1) were identified in families with FALS. The clinical manifestations of these patients include spinal onset, predominant lower motor neurons presentation and absence of cognitive involvement. Functional analysis showed that all three SOD1 variants led to increased reactive oxygen species (ROS) levels, reduced cell viability and formation of cytoplasmic aggregates. Remarkably, the decreased cell viability induced by variants was rescued after treatment with the ROS inhibitor N-acetylcysteine. This study identified three SOD1 variants in three families with FALS. The variant SOD1 toxicity was associated with oxidative damage and aggregation, and N-acetylcysteine could rescue the decreased cell viability induced by these variants. Our findings support a pathogenic role for ROS in SOD1 deficiencies and provide a potential drug N-acetylcysteine for ALS therapy, especially in SOD1 patients with limb onset.

PbO nanoparticles increase the expression of ICAM-1 and VCAM-1 by increasing reactive oxygen species production in choroid plexus.

PbO nanoparticles (nano-PbO) are widely used in the production of electrode materials, but exposure to them can cause brain damage. The first barrier preventing nano-PbO from entering the brain is the choroid plexus. However, the effect of nano-PbO on the choroid plexus remains unclear. Thus, the purpose of this study was to investigate the effect of nano-PbO exposure on lymphocyte cells infiltration, the adhesion protein of the choroid plexus as well as the role of reactive oxygen species (ROS) during the process. Results showed that nano-PbO exposure increased the percentage of lymphocyte cells in the brain and upregulated the expression of surface adhesion proteins, including intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) in choroid plexus. Meanwhile, nano-PbO treatment also resulted in the increase of intercellular ROS production, and significantly decrease glutathione (GSH) content, glutathione peroxidase (GSH-PX) activity, and superoxide dismutase (SOD) activity in Z310 cells beside the increase of ICAM and VCAM-1 expression. Treatment with ROS inhibitor N-acetylcysteine (NAC) significantly downregulated the expression of ICAM-1 and VCAM-1expression. In conclusion, exposure to nano-PbO increases the expression of ICAM-1 and VCAM-1 through oxidative stress, which may contribute to peripheral lymphocyte cells infiltration into the brain.

Neuronal nitric oxide synthase/reactive oxygen species pathway is involved in apoptosis and pyroptosis in epilepsy.

Dysfunction of neuronal nitric oxide synthase contributes to neurotoxicity, which triggers cell death in various neuropathological diseases, including epilepsy. Studies have shown that inhibition of neuronal nitric oxide synthase activity increases the epilepsy threshold, that is, has an anticonvulsant effect. However, the exact role and potential mechanism of neuronal nitric oxide synthase in seizures are still unclear. In this study, we performed RNA sequencing, functional enrichment analysis, and weighted gene coexpression network analysis of the hippocampus of tremor rats, a rat model of genetic epilepsy. We found damaged hippocampal mitochondria and abnormal succinate dehydrogenase level and Na+-K+-ATPase activity. In addition, we used a pilocarpine-induced N2a cell model to mimic epileptic injury. After application of neuronal nitric oxide synthase inhibitor 7-nitroindazole, changes in malondialdehyde, lactate dehydrogenase and superoxide dismutase, which are associated with oxidative stress, were reversed, and the increase in reactive oxygen species level was reversed by 7-nitroindazole or reactive oxygen species inhibitor N-acetylcysteine. Application of 7-nitroindazole or N-acetylcysteine downregulated the expression of caspase-3 and cytochrome c and reversed the apoptosis of epileptic cells. Furthermore, 7-nitroindazole or N-acetylcysteine downregulated the abnormally high expression of NLRP3, gasdermin-D, interleukin-1β and interleukin-18. This indicated that 7-nitroindazole and N-acetylcysteine each reversed epileptic cell death. Taken together, our findings suggest that the neuronal nitric oxide synthase/reactive oxygen species pathway is involved in pyroptosis of epileptic cells, and inhibiting neuronal nitric oxide synthase activity or its induced oxidative stress may play a neuroprotective role in epilepsy.

Silver Nanoparticles Suppress Retinoic Acid-Induced Neuronal Differentiation in Human-Derived Neuroblastoma SH-SY5Y Cells

Nanoparticles are being used in an increasing number of applications in a wide range of fields; however, these particles can migrate to the brain, raising concerns over their potential as risk factors of neurodevelopment disorders. Here, we examined the effects of silver nanoparticles with a diameter of 10 nm (nAg10) on neural differentiation in human-derived neuroblastoma SH-SY5Y cells. SH-SY5Y cells treated with retinoic acid undergo neuronal differentiation characterized by increased expression of brain-derived neurotrophic factor (BDNF); however, co-treatment of these cells with retinoic acid (RA) and nAg10 significantly mitigated this RA-induced BDNF expression. RA-induced neurite outgrowth and extracellular secretion of dopamine were significantly suppressed by nAg10 in a concentration-dependent manner. Reactive oxygen species (ROS) production was enhanced in cells co-treated with RA and nAg10, and the expression level of BDNF was restored by co-treatment with nAg10 and an ROS inhibitor (N-acetylcysteine). nAg10-induced mitochondrial ROS production and decreased mitochondrial fusion-related gene expression. In summary, nAg10 suppressed retinoic acid-induced neuronal differentiation in SH-SY5Y cells via the oxidative stress pathway, induced mitochondrial ROS production, and decreased mitochondrial fusion-related gene expression.

Niclosamide Inhibits the Growth of Acute Lymphoblastic Leukemia Cells By Increasing Intracellular ROS and Activation of p53-PUMA/NOXA

Acute lymphoblastic leukemia (ALL) is a heterogeneous clonal malignancy originated from B- or T-cell lymphoid precursor cells. The prognosis is extremely poor in refractory or relapsed cases. Niclosamide is an FDA-approved oral anthelmintic drug with anti-cancer property. In the present study, we investigated the anti-leukemic effect of niclosamide in ALL cells in vitro and in vivo. ALL cell lines REH and NALM-6, and primary cells of patients with ALL were treated with niclosamide according to the concentration gradient, and then detected by trypan blue, MTS, and soft agar colony assays. The transcriptional and translational levels of apoptosis/anti-apoptosis-related genes were assessed by immunoblotting and quantitative real-time PCR. Flow cytometry was used to detect the effect of niclosamide on apoptosis of ALL cells, mitochondrial membrane potential, and intracellular specific reactive oxygen species (ROS) levels. For animal studies, we generated a mouse xenograft model with NOD prkdc-/-IL-2Rg-/- mice intravenously engrafted with NALM-6-luc cells, the NALM-6 cells infected with retrovirus expressing luciferase. Mice were treated with 25 mg/kg/day niclosamide or solvent twice a day intraperitoneally. The effect of niclosamide against leukemia cells in mice was dynamically evaluated by an in vivo imaging system. Flow cytometry was used to analyze the percentage of leukemia cells in spleens and bone marrows of sacrificed mice. The overall survival of mice was evaluated by Kaplan-Meier survival curve. In the cell viability assay, we found that niclosamide effectively inhibited REH, NALM-6 and primary ALL cells with IC50 values of 1.72, 3.58 and 1.36 μmol/L, respectively. Immunoblotting showed increased levels of pro-apoptotic proteins p53, PUMA, NOXA, cyto C and PARP, but decreased level of anti-apoptotic protein survivin in ALL cells treated with niclosamide in a dose- and time-dependent manner. Flow cytometry showed that niclosamide induced apoptosis and mitochondrial membrane potential in ALL cells. We also found that the level of ROS began to increase in cells treated by niclosamide for 2 hours, which reached the maximum at 8 hours. The treatment of ROS inhibitor N-acetylcysteine (NAC) attenuated niclosamide-induced apoptosis of REH and NALM-6 cells, which reduced by 18.12% and 8.02%, respectively. NAC also inhibited niclosamide-induced accumulation of intracellular p53/PUMA/NOXA proteins in these cells. In the animal study, in vivo imaging system showed significantly reduced tumor burdens in mice treated with niclosamide compared with controls, with bioluminescence signals of 15.53 and 4.04 on day 21, respectively. Mice treated with niclosamide survived longer than controls (32.5 days vs 26.5 days, p < 0.01), which had lower percentage of CD45+ CD19+ leukemia cells in their bone marrows and spleens, compared with the control group (61.10% vs 34.76% and 54.88% vs 26.40%, respectively). In the present study, we found that niclosamide potently inhibited the growth of ALL cells and induced apoptosis via increased levels of ROS and the activation of p53 signaling. Our findings suggest that niclosamide may be a promisingly potent agent for ALL therapy.

Combined Treatment (Ultraviolet-C/Physapruin A) Enhances Antiproliferation and Oxidative-Stress-Associated Mechanism in Oral Cancer Cells.

Physapruin A (PHA), a Physalis peruviana-derived withanolide, exhibits antiproliferation activity against oral and breast cancer cells. However, its potential antitumor effects in combined treatments remain unclear. This investigation focused on evaluating the impact of the combined treatment of ultraviolet-C with PHA (UVC/PHA) on the proliferation of oral cancer cells. The UVC-caused antiproliferation was enhanced by combination with PHA in oral cancer (Ca9-22 and CAL 27) but not normal cells (SG), as evidenced by ATP detection, compared with UVC or PHA alone. UVC/PHA showed a greater extent of subG1 increase, G2/M arrest, annexin-V-assessed apoptosis, caspase 3/7 activation, and reactive oxygen species (ROS) in the UVC or PHA treatment of oral cancer compared to normal cells. Moreover, the mitochondrial functions, such as mitochondrial superoxide bursts and mitochondrial membrane potential destruction, of oral cancer cells were also enhanced by UVC/PHA compared to UVC or PHA alone. These oxidative stresses triggered γH2AX and 8-hydroxyl-2'-deoxyguanosine-assessed DNA damage to a greater extent under UVC/PHA treatment than under UVC or PHA treatment alone. The ROS inhibitor N-acetylcysteine reversed all these UVC/PHA-promoted changes. In conclusion, UVC/PHA is a promising strategy for decreasing the proliferation of oral cancer cells but shows no inhibitory effect on normal cells.

Gomisin A enhances the antitumor effect of paclitaxel by suppressing oxidative stress in ovarian cancer.

Gomisin A (GA) is an effective component of Schisandra. The crude extracts of Schisandra chinensis and its active ingredients have been shown to inhibit multidrug resistance in tumour cells. Reactive oxygen species (ROS) have different roles in cancer and may contribute to therapy resistance. The human ovarian cancer (OC) cell lines SKOV3 and A2780, and a mouse model of OC, were used in the present study. MTT assay, colony formation assay, flow cytometry, western blot analysis, and haematoxylin and eosin (H&E) staining were performed to determine the antitumor effect of GA and paclitaxel (PTX) in vitro and in vivo. The ROS inhibitor N-acetyl cysteine (NAC) was used to assess the mechanism underlying the chemosensitizing effects of GA. Notably, the proliferation of OC cells was inhibited by PTX, which could be enhanced by the ROS inhibitor NAC or GA. Treatment with NAC + PTX or GA + PTX enhanced the cell cycle arrest, but not apoptosis, induced by PTX. Moreover, the molecular mechanism underlying this effect may be that GA decreases the levels of ROS in ovarian cancer cells and inhibits cell cycle progression by downregulating the expression of the cell cycle proteins cyclin-dependent kinase 4 and cyclin B1. In conclusion, the combination of PTX and the ROS inhibitor GA may be a novel strategy in OC chemotherapy.

Crassolide Induces G2/M Cell Cycle Arrest, Apoptosis, and Autophagy in Human Lung Cancer Cells via ROS-Mediated ER Stress Pathways.

Crassolide, a cembranoid diterpene extracted from the soft coral Lobophytum crissum, has been proven to possess antioxidant and immunomodulatory properties. In the present study, we assessed the anticancer effects of crassolide on human H460 non-small-cell lung cancer (NSCLC) cells. We found that crassolide exerted cytotoxic effects on H460 cancer cells in vitro, inducing G2/M phase arrest and apoptosis. In addition, in H460 cells exposed to crassolide, the expression of the autophagy-related proteins LC3-II and beclin was increased, while the expression of p62 was decreased. Moreover, inhibiting autophagy with chloroquine (CQ) suppressed the crassolide-induced G2/M arrest and apoptosis of H460 cells. Moreover, we also found that crassolide induced endoplasmic reticulum (ER) stress in lung cancer cells by increasing the expression of ER stress marker proteins and that the crassolide-induced G2/M arrest, apoptosis, and autophagy were markedly attenuated by the ER stress inhibitor 4-phenylbutyric acid (4-PBA). Furthermore, we found that crassolide promoted reactive oxygen species (ROS) production by H460 cells and that the ROS inhibitor N-acetylcysteine (NAC) decreased the crassolide-induced ER stress, G2/M arrest, apoptosis, and autophagy. In conclusion, our findings show that crassolide inhibits NSCLC cell malignant biological behaviors for the first time, suggesting that this effect may be mechanistically achieved by inducing G2/M arrest, apoptosis, and autophagy through ROS accumulation, which activates the ER stress pathway. As a result of our findings, we now have a better understanding of the molecular mechanism underlying the anticancer effect of crassolide, and we believe crassolide might be a candidate for targeted cancer therapy.

Effects of Montelukast on Arsenic-Induced Epithelial-Mesenchymal Transition and the Role of Reactive Oxygen Species Production in Human Bronchial Epithelial Cells.

Background: Epithelial-mesenchymal transition (EMT) of airway lung epithelial cells is considered a major driver of fibrosis and airway remodeling. Arsenic exposure is well known to cause the malignant transformation of cells, including those in the lung. Accumulating studies have shown that arsenic exposure is associated with chronic pulmonary diseases. However, clinical treatment for arsenic-induced pulmonary damage has not been well investigated. Materials and Methods: The therapeutic effects of montelukast and its combination with fluticasone on sodium arsenite-induced EMT changes in normal human bronchial cells were investigated. The cell migration ability was evaluated by Transwell and wound healing assays. EMT marker expression was determined by immunoblotting. Furthermore, the role of reactive oxygen species (ROS) generation in arsenic-induced EMT and the effect of montelukast on this process were determined by ROS inhibitor treatment and ROS measurement, respectively. Results: Montelukast was effective at reducing arsenic-induced cell migration and mesenchymal protein (fibronectin, MMP-2, N-cadherin, β-catenin, and SMAD2/3) expression. Arsenic-induced ROS production was attenuated by pretreatment with montelukast. Treatment with the ROS inhibitor N-acetyl cysteine reduced arsenic-induced NF-kB phosphorylation and the mesenchymal protein expression, indicating that ROS production is critical for arsenic-induced EMT. In addition, combined treatment with montelukast and fluticasone reversed the inhibitory effects of montelukast on cell migration. The expression of fibronectin, MMP-2 induced by arsenic was further enhanced by the combination treatment compared with montelukast treatment only. Conclusion: This study demonstrated that montelukast is effective at reducing arsenic-induced EMT in human bronchial epithelial cells. Through the inhibition of arsenic-induced ROS generation and NF-kB activation, which is critical for arsenic-induced EMT, montelukast inhibited arsenic-induced cell migration and the expression of extracellular matrix proteins and several EMT-regulating transcription factors. The combination of fluticasone with montelukast reversed the inhibitory effect of montelukast on arsenic-induced EMT. This study provides therapeutic strategies and mechanisms for arsenic-induced pulmonary epithelial damage.