Oxidative stress and apoptosis: a new treatment paradigm in cancer

A potential therapeutic strategy based on acute oxidative stress induction for wild-type NRF2/KEAP1 lung squamous cell carcinoma

Extensive efforts have been conducted in the search for new targetable drivers of lung squamous cell carcinoma (LUSC); to date, however, candidates remain mostly unsuccessful. One of the oncogenic pathways frequently found to be active in LUSC is NFE2L2 (NRF2 transcription factor), the levels of which are regulated by KEAP1. Mutations in NFE2L2 or KEAP1 trigger NRF2 activation, an essential protector against reactive oxygen species (ROS). We hypothesized that the frequency of NRF2 activation in LUSC (∼35 %) may reflect a sensitivity of LUSC to ROS. Results from this study reveal that whereas tumors containing active forms of NRF2 were protected, ROS induction in wild-type NFE2L2/KEAP1 LUSC cells triggered ferroptosis. The mechanism of ROS action in normal-NRF2 LUSC cells involved transient NRF2 activation, miR-126-3p/miR-126-5p upregulation, and reduction of p85β and SETD5 levels. SETD5 levels reduction triggered pentose pathway gene levels increase to toxic values. Simultaneous depletion of p85βPI3K and SETD5 triggered LUSC cell death, while p85βPI3K and SETD5 overexpression rescued survival of ROS-treated normal-NRF2 LUSC cells. This shows that the cascade involving NRF2 > miR-126-3p, miR-126-5p > p85βPI3K and SETD5 is responsible for ROS-induced cell death in normal-NRF2 LUSC. Transient ROS-induced cell death is shown in 3D spheroids, patient-derived organoids, and in xenografts of wild-type NFE2L2/KEAP1 LUSC cells, supporting the potential of acute local ROS induction as a therapeutic strategy for LUSC patients with normal-NRF2.

Vernodalin Triggers ROS-Mediated Apoptosis in TPC-1 Human PapillaryThyroid Cancer Cells via Suppression of the MAPKs Signaling Pathway

BACKGROUND

Thyroid Cancer (TC) is an endocrine organ malignancy that has become more common in recent decades. Vernodalin (VN), a cytotoxic sesquiterpene, has been reported to exhibit anticancer properties against human breast and liver cancer cells. However, no study has explored the efficacy of VN with respect to its antiproliferative and apoptotic action on human Papillary Thyroid Cancer cells (PTC).

OBJECTIVE

The study intended to examine the antitumor and antiproliferative effects of VN and the apoptosis mechanisms underlying its action on TPC-1 human PTC cells.

METHODS

In this study, we examined the VN cell viability by MTT assay; performed ROS measurement by DCFH staining method, MMP identification by Rh-123 staining method, and apoptotic morphological assay by employing AO/EB and DAPI stain method, and further, p38 MAPK/ERK/JNK cell proliferation markers were determined by western blotting technique.

RESULTS

The findings showed that VN could inhibit the growth of PTC cells by increasing intracellular ROS, damaging MMP, and stimulating apoptosis in a concentration-dependent manner. The study demonstrated how VN inhibited TPC-1 cell viability by causing ROS-induced cell death via the MAPK signaling pathway.

CONCLUSION

VN may serve as an agonist to impact apoptosis in PTC cells. In human PTC, VN could play an effective role in chemotherapy. More studies pertaining to animal tumor models are needed to prove its anti-cancer effectiveness in vivo.

Effects of alpha lipoic acid treatment during in vitro maturation on the development of porcine somatic cell nuclear transfer embryos

Oxidative stress influences the embryo production efficiency in vitro. We investigated the effects of alpha lipoic acid (ALA) treatment during the in vitro maturation (IVM) period on the porcine somatic cell nuclear transfer (SCNT) embryo production. After IVM, maturation rates of the 12.5- and 25-μM ALA-treated groups were not significantly different from those of the 0-μM ALA-treated group. Compared to those in the 0-μM ALA-treated group, the reactive oxygen species and glutathione levels were significantly decreased and increased, respectively, in the cytoplasm of matured oocytes in the 12.5-50-μM ALA-treated groups. Apoptosis rate in cumulus cells after IVM was significantly lower in the 12.5-50-μM ALA-treated groups than in the 0-μM ALA-treated group. Blastocyst formation rate was significantly higher in parthenogenetic oocytes treated with 12.5-μM ALA than in the 0-, 25-, and 50-μM ALA-treated groups. Similarly, in SCNT embryos, the 12.5-μM ALA-treated group showed a significantly higher blastocyst formation rate than the 0-μM ALA-treated group. Apoptosis rate in SCNT blastocysts was significantly decreased by 12.5-μM ALA treatment. The results showed that treatment with 12.5-μM ALA during IVM improves porcine SCNT embryo development and partial quality.

Proton irradiation induced reactive oxygen species promote morphological and functional changes in HepG2 cells

The increased use of proton therapy has led to the need of better understanding the cellular mechanisms involved. The aim of this study was to investigate the effects induced by the accelerated proton beam in hepatocarcinoma cells. An existing facility in IFIN-HH, a 3 MV Tandetron™ accelerator, was used to irradiate HepG2 human hepatocarcinoma cells with doses between 0 and 3 Gy. Colony formation was used to assess the influence of radiation on cell long-term replication. Also, the changes induced at the mitochondrial level were shown by increased ROS and ATP levels as well as a decrease in the mitochondrial membrane potential. An increased dose has induced DNA damages and G₂/M cell cycle arrest which leads to caspase 3/7 mediated apoptosis and senescence induction. Finally, the morphological and ultrastructural changes were observed at the membrane level and the nucleus of the irradiated cells. Thus, proton irradiation induces both morphological and functional changes in HepG2 cells.

A comprehensive review on modulation of SIRT1 signaling pathways in the immune system of COVID-19 patients by phytotherapeutic melatonin and epigallocatechin-3-gallate

SARS-CoV-2 infection has now become the world's most significant health hazard, with the World Health Organization declaring a pandemic on March 11, 2020. COVID-19 enters the lungs through angiotensin-converting enzyme 2 (ACE2) receptors, alters various signaling pathways, and causes immune cells to overproduce cytokines, resulting in mucosal inflammation, lung damage, and multiple organ failure in COVID-19 patients. Although several antiviral medications have been effective in managing the virus, they have not been effective in lowering the inflammation and symptoms of the illness. Several studies have found that epigallocatechin-3-gallate and melatonin upregulate sirtuins proteins, which leads to downregulation of pro-inflammatory gene transcription and NF-κB, protecting organisms from oxidative stress in autoimmune, respiratory, and cardiovascular illnesses. As a result, the purpose of this research is to understand more about the molecular pathways through which these phytochemicals affect COVID-19 patients' impaired immune systems, perhaps reducing hyperinflammation and symptom severity. PRACTICAL APPLICATIONS: Polyphenols are natural secondary metabolites that are found to be present in plants. EGCG a polyphenol belonging to the flavonoid family in tea has potent anti-inflammatory and antioxidative properties that helps to counter the inflammation and oxidative stress associated with many neurodegenerative diseases. Melatonin, another strong antioxidant in plants, has been shown to possess antiviral function and alleviate oxidative stress in many inflammatory diseases. In this review, we propose an alternative therapy for COVID-19 patients by supplementing their diet with these nutraceuticals that perhaps by modulating sirtuin signaling pathways counteract cytokine storm and oxidative stress, the root causes of severe inflammation and symptoms in these patients.

Ferrocene-appended anthraquinone and coumarin as redox-active cytotoxins

Appending of ferrocene (Fc) to biologically-active organic backbones can generate novel multi-functional species for targeting bacteria and cancer. In this work Fc was linked to coumarin and anthraquinone with the goal of harnessing the redox-active Fc centre to generate new compounds that exhibit cytoxicity through the generation of toxic reactive oxygen species (ROS). A Cu(I)-catalyzed azide-alkyne cycloaddition "click" reaction was used to connect the organic and Fc components via a triazole linker. Cyclic voltammetry shows that the Fc potentials are suitable for oxidation by biological hydrogen peroxide to give reactive ferrocenium (Fc⁺) species, which can then generate hydroxyl radicals. The ability of the compounds to generate hydroxyl radicals in the presence of hydrogen peroxide was shown directly using EPR spin-trapping experiments. Furthermore, in vitro studies in MCF-7 breast cancer cells show significant increases in ROS following incubation with the Fc-functionalized compounds. Screening for antibacterial activity produced negative results for all of the Fc compounds, consitent with low levels of hydrogen peroxide typically found in bacteria. By contrast, Fc-coumarin showed cytotoxicity against A549 lung cancer and SKOV3 ovarian cancer cell lines, whereas the parent compound was inactive. This is consistent both with the cytoxic potential of the Fc group and the elevated hydrogen peroxide levels found in many cancers. Interestingly, the anthraquinone compounds showed the opposite effect with the parent compounds showing modest activity against A549 cells, but the Fc compounds being inactive. This demonstrates other potential negative impacts of including Fc, such as significantly increased lipophilicity.

Epoxiconazole profoundly alters rat brain and properties of neural stem cells

Epoxiconazole (EPX), a widely used fungicide for domestic, medical, and industrial applications, could cause neurodegenerative diseases. However, the underling mechanism of neurotoxicity is not well understood. This study aimed to investigate the possible toxic outcomes of Epoxiconzole, a triazole fungicide, on the brain of adult rats in vivo, and in vitro on neural stem cells derived from the subventricular zone of newborn Wistar rats. Our results revealed that oral exposure to EPX at these concentrations (8, 24, 40, 56 mg/kg bw representing respectively NOEL (no observed effect level), NOEL × 3, NOEL × 5, and NOEL × 7) for 28 days caused a considerable generation of oxidative stress in adult rat brain tissue. Furthermore, a significant augmentation in lipid peroxidation and protein oxidation has been found. Moreover, it induced an elevation of DNA fragmentation as assessed by the Comet assay. Indeed, EPX administration impaired activities of antioxidant enzymes and inhibited AChE activity. Concomitantly, this pesticide produced histological alterations in the brain of adult rats. Regarding the embryonic neural stem cells, we demonstrated that the treatment by EPX reduced the viability of cells with an IC50 of 10 μM. It also provoked the reduction of cell proliferation, and EPX triggered arrest in G1/S phase. The neurosphere formation and self-renewal capacity was reduced and associated with decreased differentiation. Moreover, EPX induced cytoskeleton disruption as evidenced by immunocytochemical analysis. Our findings also showed that EPX induced apoptosis as evidenced by a loss of mitochondrial transmembrane potential (ΔΨm) and an activation of caspase-3. In addition, EPX promoted ROS production in neural stem cells. Interestingly, the pretreatment of neural stem cells with the N-acetylcysteine (ROS scavenger) attenuated EPX-induced cell death, disruption of neural stem cells properties, ROS generation and apoptosis. Thus, the use of this hazardous material should be restricted and carefully regulated.

Protective effect of baicalin against arsenic trioxide-induced acute hepatic injury in mice through JAK2/STAT3 signaling pathway

Baicalin (BA) is a kind of flavonoid that is isolated from Scutellaria baicalensis Georgi, which has been verified to have hepatoprotective effects in some diseases. However, the role of BA in acute hepatic injury induced by arsenic trioxide (ATO) remains unclear. The aim of this study was to investigate the protective action of BA on acute hepatic injury induced by ATO and to probe its possible mechanism. Mice were pretreated with BA (50, 100 mg/kg) by gavage. After 7 h, ATO (7.5 mg/kg) was injected intraperitoneally to induce liver injury. After 7 days of treatment, serum and hepatic specimens were collected and assayed to evaluate the hepatoprotective effect of BA. Pathological sections and the liver function index indicated that ATO caused significant liver injury. The fluorescence of reactive oxygen species and oxidative stress indicators showed that ATO also increased oxidative stress. The inflammatory markers in ATO-induced mice also increased significantly. Staining of the terminal deoxynucleotidyl transferase dUTP nick end labeling and apoptotic factor assay showed that apoptosis increased. However, with BA pretreatment, these changes were significantly weakened. In addition, BA treatment promoted the expression of proteins related to the JAK2/STAT3 signaling pathway. The results suggest that BA can ameliorate acute ATO-induced hepatic injury in mice, which is related to the inhibition of oxidative stress, thereby reducing inflammation and apoptosis. The mechanism of this protection is potentially related to the JAK2/STAT3 signaling pathway.

Açai (Euterpe oleracea Mart.) Seed Extract Induces ROS Production and Cell Death in MCF-7 Breast Cancer Cell Line

Euterpe oleracea Mart. (açai) is a native palm from the Amazon region. There are various chemical constituents of açai with bioactive properties. This study aimed to evaluate the chemical composition and cytotoxic effects of açai seed extract on breast cancer cell line (MCF-7). Global Natural Products Social Molecular Networking (GNPS) was applied to identify chemical compounds present in açai seed extract. LC-MS/MS and molecular networking were employed to detect the phenolic compounds of açai. The antioxidant activity of açai seed extract was measured by DPPH assay. MCF-7 breast cancer cell line viability was evaluated by MTT assay. Cell death was evaluated by flow cytometry and time-lapse microscopy. Autophagy was evaluated by orange acridin immunofluorescence assay. Reactive oxygen species (ROS) production was evaluated by DAF assay. From the molecular networking, fifteen compounds were identified, mainly phenolic compounds. The açai seed extract showed cytotoxic effects against MCF-7, induced morphologic changes in the cell line by autophagy and increased the ROS production pathway. The present study suggests that açai seed extract has a high cytotoxic capacity and may induce autophagy by increasing ROS production in breast cancer. Apart from its antioxidant activity, flavonoids with high radical scavenging activity present in açai also generated NO (nitric oxide), contributing to its cytotoxic effect and autophagy induction.

In vitro Anticancer Effects of JI017 on Two Prostate Cancer Cell Lines Involve Endoplasmic Reticulum Stress Mediated by Elevated Levels of Reactive Oxygen Species

Prostate cancer is the second most commonly diagnosed cancer, and prostate cancer is the second most common cause of cancer death in United States men after lung cancer. Many therapies are used to treat prostate cancer, and chemotherapy is one of the most relevant treatments. However, chemotherapy has many side effects, and repeated administration of chemotherapeutic agents leads to acquired resistance. Thus, new drugs with few side effects are needed. We investigated the molecular mechanism of action of JI017 in human prostate cancer cells. We identified an endoplasmic reticulum (ER) stress pathway that depended on the reactive oxygen species (ROS) pathway and played a crucial role in JI017-induced apoptosis. We measured cell viability by the MTS assay to determine the effect of JI017. Analysis of apoptosis, mitochondrial dysfunction, and cell cycle features was performed by flow cytometry. We used western blot and RT-PCR to measure the levels of the proteins of the unfolded protein response (UPR) pathway and apoptosis markers. Immunoprecipitation assay and transfection were used to determine the expression levels of proteins interacting with the pathways influenced by JI017 in prostate cancer cells. The anticancer effects induced by JI017 were evaluated. JI017 induced cell death that regulated apoptotic molecules and caused cell cycle arrest that inhibited the proliferation of cancer cells. Moreover, JI017 generated ROS. Accumulation of ROS caused ER stress through the PERK-eIF2α-CHOP and IRE1α-CHOP pathways. Furthermore, persistent activation of the UPR pathway induced by JI017 treatment triggered mitochondrial dysfunction, including dissipation of mitochondrial membrane potential, which activated intrinsic apoptotic pathway in human prostate cancer cells. The data indicated that N-acetyl-L-cysteine diminished apoptosis. We demonstrated that JI017 induced ER stress and cell death. Anticancer properties of JI017 in prostate cancer cells and in a human prostate cancer model involved ROS-mediated ER stress. Thus, JI017 treatment provides a new strategy for chemotherapy of prostate cancer.

Precision Redox: The Key for Antioxidant Pharmacology

Significance: The redox balance of cells provides a stable microenvironment for biological macromolecules to perform their physiological functions. As redox imbalance is closely related to the occurrence and development of a variety of diseases, antioxidant therapies are an attractive option. However, redox-based therapeutic strategies have not yet shown satisfactory results. To find the key reason is of great significance. Recent Advances: We emphasize the precise nature of redox regulation and elucidate the importance and necessity of precision redox strategies from three aspects: differences in redox status, differences in redox function, and differences in the effects of redox therapy. We then propose the "5R" principle of precision redox in antioxidant pharmacology: "Right species, Right place, Right time, Right level, and Right target." Critical Issues: Redox status must be considered in the context of species, time, place, level, and target. The function of a biomacromolecule and its cellular signaling role are closely dependent on redox status. Accurate evaluation of redox status and specific interventions are critical for the success of redox treatments. Precision redox is the key for antioxidant pharmacology. The precise application of antioxidants as nutritional supplements is also key to the general health of the population. Future Directions: Future studies to develop more accurate methods for detecting redox status and accurately evaluating the redox state of different physiological and pathological processes are needed. Antioxidant pharmacology should consider the "5R" principle rather than continuing to apply global nonspecific antioxidant treatments. Antioxid. Redox Signal. 34, 1069-1082.

Mitochondria: Insights into Crucial Features to Overcome Cancer Chemoresistance

Mitochondria are key regulators of cell survival and are involved in a plethora of mechanisms, such as metabolism, Ca²⁺ signaling, reactive oxygen species (ROS) production, mitophagy and mitochondrial transfer, fusion, and fission (known as mitochondrial dynamics). The tuning of these processes in pathophysiological conditions is fundamental to the balance between cell death and survival. Indeed, ROS overproduction and mitochondrial Ca²⁺ overload are linked to the induction of apoptosis, while the impairment of mitochondrial dynamics and metabolism can have a double-faceted role in the decision between cell survival and death. Tumorigenesis involves an intricate series of cellular impairments not yet completely clarified, and a further level of complexity is added by the onset of apoptosis resistance mechanisms in cancer cells. In the majority of cases, cancer relapse or lack of responsiveness is related to the emergence of chemoresistance, which may be due to the cooperation of several cellular protection mechanisms, often mitochondria-related. With this review, we aim to critically report the current evidence on the relationship between mitochondria and cancer chemoresistance with a particular focus on the involvement of mitochondrial dynamics, mitochondrial Ca²⁺ signaling, oxidative stress, and metabolism to possibly identify new approaches or targets for overcoming cancer resistance.

Ruthenium-loaded mesoporous silica as tumor microenvironment-response nano-fenton reactors for precise cancer therapy

BACKGROUND

Nano-Fenton reactors as novel strategy to selectively convert hydrogen peroxide (H₂O₂) into active hydroxyl radicals in tumor microenvironment for cancer therapy had attracted much attention. However, side effects and low efficiency remain the main drawbacks for cancer precise therapy.

RESULTS

Here, ruthenium-loaded palmitoyl ascorbate (PA)-modified mesoporous silica (Ru@SiO₂-PA) was successfully fabricated and characterized. The results indicated that Ru@SiO₂-PA under pH6.0 environment displayed enhanced growth inhibition against human cancer cells than that of pH7.4, which indicated the super selectivity between cancer cells and normal cells. Ru@SiO₂-PA also induced enhanced cancer cells apoptosis, followed by caspase-3 activation and cytochrome-c release. Mechanism investigation revealed that Ru@SiO₂-PA caused enhanced generation of superoxide anion, which subsequently triggered DNA damage and dysfunction of MAPKs and PI3K/AKT pathways. Moreover, Ru@SiO₂-PA effectively inhibited tumor spheroids and tumor xenografts growth in vivo by induction of apoptosis. The real-time imaging by monitoring Ru fluorescence in vitro and in vivo revealed that Ru@SiO₂-PA mainly accumulated in cell nucleus and tumor xenografts. Importantly, Ru@SiO₂-PA showed no side effects in vivo, predicting the safety and potential application in clinic.

CONCLUSIONS

Our findings validated the rational design that Ru@SiO₂-PA can act as novel tumor microenvironment-response nano-Fenton reactors for cancer precise therapy.

Evaluation of antioxidant and anticancer activity of crude extract and different fractions of Chlorella vulgaris axenic culture grown under various concentrations of copper ions

Background

Chlorella vulgaris is a microalga potentially used for pharmaceutical, animal feed, food supplement, aquaculture and cosmetics. The current study aims to study the antioxidant and prooxidant effect of Chlorella vulgaris cultivated under various conc. of copper ions.

Methods

The axenic green microalgal culture of Chlorella vulgaris was subjected to copper stress conditions (0.00, 0.079, 0.158, 0.316 and 0.632 mg/L). The growth rate was measured at OD₆₈₀ nm and by dry weight (DW). Moreover, the Antioxidant activity against DPPH and ABTS radical, pigments and phytochemical compounds of the crude extracts (methylene chloride: Methanol, 1:1) were evaluated. The promising Cu crude extract (0.316 mg/L) further fractionated into twenty-one fractions by silica gel column chromatography using hexane, chloroform and ethyl acetate as a mobile phase.

Results

The obtained results reported that nine out of these fractions exhibited more than 50% antioxidant activity and anticancer activity against Hela cancer cell lines. Based on IC₅₀, fraction No. 7 was found to be the most effective fraction possessing a significant increase in both antioxidant and anticancer potency. Separation of active compound (s) in fraction No 7 was performed using precoated silica gel plates (TLC F₂₅₄) with ethyl acetate: hexane (9:1 v/v) as mobile phase. Confirmation of active compound separation was achieved by two-dimensional TLC and visualization of the separated compound by UV lamp. The complete identification of the separated active compound was performed by UV- Vis- spectrophotometric absorption, IR, MS, H¹-NMRT C¹³-NMR. The isolated compound ((2E,7R,11R)-3,7,11,15-Tetramethyl-2-hexadecenol) have high antioxidant activity with IC₅₀ (10.59 μg/ml) against DPPH radical assay and comparable to the capacities of the positive controls, Butylated hydroxy toluene [BHT] (IC₅₀ 11.2 μg/ml) and Vitamin C (IC₅₀ 12.9 μg/ml). Furthermore, pure isolated compound exhibited a potent anticancer activity against Hela cell line with IC₅₀ (4.38 μg/ml) compared to Doxorubicin (DOX) as synthetic drug (13.3 μg/ml). In addition, the interaction of the pure compound with Hela cancer cell line and gene expression were evaluated.

Conclusions

The authors recommend cultivation of Chlorella vulgaris in large scale under various stress conditions for use the crude extracts and semi purified fractions for making a pharmaco-economic value in Egypt and other countries.

Importance of studying primitive neuroectodermal tumors and extraosseous Ewings sarcoma of the vagina and vulva

Primitive neuroectodermal tumor (PNT) and Ewing's sarcoma are rare, round-cell tumors, characterized by the presence of the t(11; 22)(q24; q12) chromosomal translocation. A review of the literature revealed only 38 previously reported cases of vulvar PNT and Ewing's sarcoma and 15 vaginal PNT and Ewing's sarcoma. Although rare, these types of tumors should be taken into consideration when making a differential diagnosis for vulvar or vaginal tumors. The currently available data is limited, and therefore, case reports are essential for improving knowledge and management of these types of extremely rare tumors. However, further molecular and histopathological studies are essential for an improved understanding of these conditions and for an early, correct diagnosis. Although the gathered and presented data from the present review are limited, the literature demonstrates that the outcome of these types of cancer are more favorable compared with outcomes observed for carcinomas in more typical locations.

An Insight into the Mechanism of Holamine- and Funtumine-Induced Cell Death in Cancer Cells

Holamine and funtumine, steroidal alkaloids with strong and diverse pharmacological activities are commonly found in the Apocynaceae family of Holarrhena. The selective anti-proliferative and cell cycle arrest effects of holamine and funtumine on cancer cells have been previously reported. The present study evaluated the anti-proliferative mechanism of action of these two steroidal alkaloids on cancer cell lines (HT-29, MCF-7 and HeLa) by exploring the mitochondrial depolarization effects, reactive oxygen species (ROS) induction, apoptosis, F-actin perturbation, and inhibition of topoisomerase-I. The apoptosis-inducing effects of the compounds were studied by flow cytometry using the APOPercentage^TM dye and Caspase-3/7 Glo assay kit. The two compounds showed a significantly greater cytotoxicity in cancer cells compared to non-cancer (normal) fibroblasts. The observed antiproliferative effects of the two alkaloids presumably are facilitated through the stimulation of apoptosis. The apoptotic effect was elicited through the modulation of mitochondrial function, elevated ROS production, and caspase-3/7 activation. Both compounds also induced F-actin disorganization and inhibited topoisomerase-I activity. Although holamine and funtumine appear to have translational potential for the development of novel anticancer agents, further mechanistic and molecular studies are recommended to fully understand their anticancer effects.

Vernodalin induces apoptosis through the activation of ROS/JNK pathway in human colon cancer cells

Colorectal cancer is one of the most leading death-causing cancers in the world. Vernodalin, a cytotoxic sesquiterpene, has been reported to possess anticancer properties against human breast cancer cells. We aimed to examine the anticancer mechanism of vernodalin on human colon cancer cells. Vernodalin was used on human colon cancer cells, HT-29 and HCT116. The cytotoxicity of vernodalin on human colon cancer cells was determined through in vitro 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyl-tetrazolium bromide assay. Small interfering RNA was used to analyze the cascade activation of mitogen-activated protein kinase (MAPK) pathway, c-Jun N-terminal kinase (JNK) in HT-29, and HCT116 cells against vernodalin treatment. The protein expressions of caspase 3, Bcl-2, and Bax were examined through Western blot analysis. Immunoblot analysis on the JNK, ERK, and p38 MAPK pathways showed increased activation due to vernodalin treatment. It was proven from the JNK and p38 inhibition test that both pathways are significantly activated by vernodalin to induce apoptosis. Our results, collectively, showed the apoptosis-induced anticancer mechanism of vernodalin on human colon cancer cells that was mediated through the activation of JNK pathway and apoptotic regulator proteins. These results suggest that vernodalin could be developed as a potent chemotherapeutic agent for human colorectal cancer treatment.

Protective Effects of Crocetin on Arsenic Trioxide-Induced Hepatic Injury: Involvement of Suppression in Oxidative Stress and Inflammation Through Activation of Nrf2 Signaling Pathway in Rats

Purpose

Arsenic trioxide (ATO) has been shown to induce hepatic injury. Crocetin is a primary constituent of saffron, which has been verified to have antioxidant and anti-inflammatory effects. In the current experiment, we evaluated the efficacy of crocetin against ATO-induced hepatic injury and explored the potential molecular mechanisms in rats.

Methods

Rats were pretreated with 25 or 50 mg/kg crocetin 6 h prior to treating with 5 mg/kg ATO to induce hepatic injury daily for 7 days.

Results

Treatment with crocetin attenuated ATO-induced body weight loss, decreases in food and water consumption, and improved ATO-induced hepatic pathological damage. Crocetin significantly inhibited ATO-induced alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) increases. Crocetin prevented ATO-induced liver malondialdehyde (MDA) and reactive oxygen species (ROS) levels. Crocetin abrogated the ATO-induced decrease of catalase (CAT) and superoxide dismutase (SOD) activity. Crocetin was found to significantly restore the protein levels of interleukin 6 (IL-6), interleukin 1β (IL-1β), and tumor necrosis factor-alpha (TNF-α). Furthermore, crocetin promoted the expression of nuclear factor erythroid 2 related factor 2 (Nrf2), heme oxygenase-1 (HO-1), and NADP(H): quinone oxidoreductase 1 (NQO1).

Conclusion

These findings suggest that crocetin ameliorates ATO-induced hepatic injury in rats. In addition, the effect of crocetin might be related to its role in antioxidant stress, as an anti-inflammatory agent, and in regulating the Nrf2 signaling pathway.

KIF15 promotes the evolution of gastric cancer cells through inhibition of reactive oxygen species-mediated apoptosis

Kinesin family member 15 (KIF15) is a member of the kinesin superfamily of proteins, which promotes cell mitosis, participates in the transport of intracellular materials, and helps structural assembly and cell signaling pathways transduction. However, its biological role and molecular mechanisms of action in the development of gastric cancer (GC) remain unclear. In the present study, an integrated analysis of The Cancer Genome Atlas (TCGA), Gene Expression Omnibus database, and Kaplan-Meier plotter database was performed to predict the expression and prognostic value of KIF15 in GC patients. Detection of KIF15 expression in GC cells and tissues was performed by a quantitative polymerase chain reaction. In vitro cell proliferation, viability, colony formation ability and flow cytometry assays, and in vivo tumorigenicity assay, were performed to evaluate the effects of KIF15 knockdown on GC cell phenotype. It was demonstrated that the expression of KIF15 messenger RNA in GC tissues was significantly higher compared with that in adjacent tissues, and was closely associated with larger tumor size and poor patient prognosis. In addition, functional studies demonstrated that, due to the increase in reactive oxygen species (ROS) generation, the interference with the expression of KIF15 not only decreased cell proliferation but also increased cell apoptosis and induced cell cycle arrest. ROS-mediated activation of c-Jun N-terminal kinase/c-Jun signaling reduced cell proliferation by regulating the GC cell cycle and increasing apoptosis. Taken together, the results of the present study indicate that KIF15 is an oncoprotein contributing to GC progression, and is expected to help identify novel biomarkers and treatment targets in GC.

Mitochondria as target to inhibit proliferation and induce apoptosis of cancer cells: the effects of doxycycline and gemcitabine

Doxycycline has anti-tumour effects in a range of tumour systems. The aims of this study were to define the role mitochondria play in this process and examine the potential of doxycycline in combination with gemcitabine. We studied the adenocarcinoma cell line A549, its mitochondrial DNA-less derivative A549 ρ° and cultured fibroblasts. Treatment with doxycycline for 5 days resulted in a decrease of mitochondrial-encoded proteins, respiration and membrane potential, and an increase of reactive oxygen species in A549 cells and fibroblasts, but fibroblasts were less affected. Doxycycline slowed proliferation of A549 cells by 35%. Cellular ATP levels did not change. Doxycycline alone had no effect on apoptosis; however, in combination with gemcitabine given during the last 2 days of treatment, doxycycline increased caspase 9 and 3/7 activities, resulting in a further decrease of surviving A549 cells by 59% and of fibroblasts by 24% compared to gemcitabine treatment alone. A549 ρ° cells were not affected by doxycycline. Key effects of doxycycline observed in A549 cells, such as the decrease of mitochondrial-encoded proteins and surviving cells were also seen in the cancer cell lines COLO357 and HT29. Our results suggest that doxycycline suppresses cancer cell proliferation and primes cells for apoptosis by gemcitabine.

The attenuation of the toxic effects of LPS on mouse pre-implantation development by alpha-lipoic acid

The present study was conducted to evaluate the effects of alpha-lipoic acid (ALA) on quantitative and qualitative indices of mouse embryos challenged by lipopolysaccharide (LPS). Having determined the effective concentrations of LPS (1 mg/mL) that could reduce blastocyst formation rate by around 50% and the optimal concentration of ALA (10 μM) that could attenuate the toxic effects of LPS on blastocyst formation, the following indices were defined: inner cell mass and trophectoderm cell numbers, blastocyst mitochondrial distribution, ROS and GSH levels, as well as the relative expression of Tlr-4. Nrf-2 and Tnf-RI/P-60 receptor involved in inflammatory pathways. Finally, embryos derived from the experimental and control groups were transferred to synchronized recipients and their implantation rate and post-implantation capacity were determined. Treatment with LPS resulted in an increase in intracellular ROS level (P ≤ 0.05), and remarkable decreases (P ≤ 0.05) in intracellular GSH content, mitochondrial mass, and blastocyst quality. ALA attenuated all the aforementioned negative effects of LPS. The relative expression levels of Nrf-2 and Tnf-RI/P-60 receptor (P ≤ 0.05) significantly increased in response to LPS, and treatment with ALA significantly reduced the relative expression of Tnf-RI/P-60. ALA also improved the post-implantation developmental capacity of embryos treated with LPS. In conclusion, our findings indicate that the reproductive toxicity of LPS could be overcome by ALA treatment. These effects were mainly due to the improvements made in intracellular antioxidant capacity as well as suppression of some inflammatory elements, especially the main receptor of TNF-α, the Tnf-RI/P-60, involved in induction of apoptosis. These observations have important implications for dairy farming and treatment of infertility.

Berberine Protects C17.2 Neural Stem Cells From Oxidative Damage Followed by Inducing Neuronal Differentiation

Neurodegeneration is the loss of structure and/or function of neurons. Oxidative stress has been suggested as one of the common etiology in most of the neurodegenerative diseases. Previous studies have demonstrated the beneficial effects of berberine in various neurodegenerative and neuropsychiatric disorders. In this study, we hypothesized that berberine could protect C17.2 neural stem cells (NSCs) from 2,2′-Azobis(2-amidinopropane) dihydrochloride (AAPH)-induced oxidative damage then promote neuronal differentiation. AAPH was used to induce oxidative damage. After the damage, berberine protected C17.2 cells were kept cultured for another week in differentiation medium with/without berberine. Changes in cell morphology were detected by microscopy and cell viability was determined by MTT assay. Real-time PCR and western blot analysis were performed to confirm the associated pathways. Berberine was able to protect C17.2 NSCs from the oxidative damage. It lowered the cellular reactive oxygen species (ROS) level in C17.2 cells via Nuclear Factor Erythroid 2-Related Factor 1/2 (NRF1/2) – NAD(P)H Quinone Dehydrogenase 1 (NQO-1) – Heme Oxygenase 1 (HO-1) pathway. It also down-regulated the apoptotic factors-Caspase 3 and Bcl2 Associated X (Bax) and upregulated the anti-apoptotic factor-Bcl2 to reduce cell apoptosis. Besides, berberine increased C17.2 cell viability via up-regulating Extracellular-signal-Related Kinase (ERK) and phosphor-Extracellular-signal-Related Kinase (pERK) expression. Then, berberine promoted C17.2 cell to differentiate into neurons and the differentiation mechanism involved the activation of WNT/β-catenin pathway as well as the upregulation of expression levels of pro-neural factors Achaete-Scute Complex-Like 1 (ASCL1), Neurogenin 1 (NeuroG1), Neuronal Differentiation 2 (NeuroD2) and Doublecortin (DCX). In conclusion, berberine protected C17.2 NSCs from oxidative damage then induced them to differentiate into neurons.

Genetics, epigenetics and redox homeostasis in rhabdomyosarcoma: Emerging targets and therapeutics

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma accounting for 5-8% of malignant tumours in children and adolescents. Children with high risk disease have poor prognosis. Anti-RMS therapies include surgery, radiation and combination chemotherapy. While these strategies improved survival rates, they have plateaued since 1990s as drugs that target differentiation and self-renewal of tumours cells have not been identified. Moreover, prevailing treatments are aggressive with drug resistance and metastasis causing failure of several treatment regimes. Significant advances have been made recently in understanding the genetic and epigenetic landscape in RMS. These studies have identified novel diagnostic and prognostic markers and opened new avenues for treatment. An important target identified in high throughput drug screening studies is reactive oxygen species (ROS). Indeed, many drugs in clinical trials for RMS impact tumour progression through ROS. In light of such emerging evidence, we discuss recent findings highlighting key pathways, epigenetic alterations and their impacts on ROS that form the basis of developing novel molecularly targeted therapies in RMS. Such targeted therapies in combination with conventional therapy could reduce adverse side effects in young survivors and lead to a decline in long-term morbidity.

Increased Oxidative Stress Induced by Rubus Bioactive Compounds Induce Apoptotic Cell Death in Human Breast Cancer Cells

Bioactive compounds from plants represent good candidate drugs for the prevention and treatment of various forms of cancer. Berries are rich sources of bioactive compounds, and there has been an increasing interest in the study of therapeutic action of wild berries. Oxidants are generated continuously in biological system as a result of physiological process. When there is an imbalance between oxidants and antioxidants, it leads to a condition called oxidative stress. Natural compounds as inducers of oxidative stress are able to modulate the physiological functions of cancer cells leading to cell death or survival. The aim of this study was to evaluate the induction of apoptosis by isolated bioactive compounds (1-(2-hydroxyphenyl)-4-methylpentan-1-one (C1) and 2-[(3-methylbutoxy) carbonyl] benzoic acid (C2)) from Rubus fairholmianus against MCF-7 breast cancer cells. The exposure of C1 and C2 reduced viability (IC₅₀ of C1: 4.69; C2: 8.36 μg/mL) and proliferation. Cytochrome c release from mitochondria and changes in mitochondrial membrane potential of treated cells supported the intrinsic apoptotic cell death. Reactive oxygen species (ROS) production after treatment with C1 and C2 was found to be higher and induced nuclear damage. Expression of apoptotic proteins after the treatments was significantly upregulated as indicated using immunofluorescence (caspase 9, p53, and Bax), western blotting (p53, cleaved PARP, cytochrome c, and Bax), and ELISA (caspase 9) analysis. Overall, C1 was more cytotoxic, increased the ROS production in dichlorodihydrofluorescein diacetate assay, and induced apoptosis in breast cancer cells. These results illustrate that berry bioactive compounds have strong chemopreventive potential. In this article, we provide information on prooxidant and anticancer activities of Rubus bioactive compounds. Natural products have always demonstrated a significant contribution to the development of several cancer chemotherapeutic drugs. Most of these compounds are known to affect the redox state of the cell; and studies on these compounds have focused on their antioxidant property instead of prooxidant properties.

Cold Argon Plasma as Adjuvant Tumour Therapy on Progressive Head and Neck Cancer: A Preclinical Study

Investigating cold argon plasma (CAP) for medical applications is a rapidly growing, innovative field of research. The controllable supply of reactive oxygen and nitrogen species through CAP has the potential for utilization in tumour treatment. Maxillofacial surgery is limited if tumours grow on vital structures such as the arteria carotis. Here CAP could be considered as an option for adjuvant intraoperative tumour therapy especially in the case of squamous cell carcinoma of the head and neck. Further preclinical research is necessary to investigate the efficacy of this technology for future clinical applications in cancer treatment. Initially, a variety of in vitro assays was performed on two cell lines that served as surrogate for the squamous cell carcinoma (SCC) and healthy tissue, respectively. Cell viability, motility and the activation of apoptosis in SCC cells (HNO97) was compared with those in normal HaCaT keratinocytes. In addition, induction of apoptosis in ex vivo CAP treated human tissue biopsies of patients with tumours of the head and neck was monitored and compared to healthy control tissue of the same patient. In response to CAP treatment, normal HaCaT keratinocytes differed significantly from their malignant counterpart HNO97 cells in cell motility only whereas cell viability remained similar. Moreover, CAP treatment of tumour tissue induced more apoptotic cells than in healthy tissue that was accompanied by elevated extracellular cytochrome c levels. This study promotes a future role of CAP as an adjuvant intraoperative tumour therapy option in the treatment of head and neck cancer. Moreover, patient-derived tissue explants complement in vitro examinations in a meaningful way to reflect an antitumoral role of CAP.

Self-Assembled Responsive Bilayered Vesicles with Adjustable Oxidative Stress for Enhanced Cancer Imaging and Therapy

In the present study, we report the development of magnetic-plasmonic bilayer vesicles assembled from iron oxide-gold Janus nanoparticles (Fe₃O₄-Au JNPs) for reactive oxygen species (ROS) enhanced chemotherapy. The amphiphilic Fe₃O₄-Au JNPs were grafted with poly(ethylene glycol) (PEG) on the Au surface and ROS-generating poly(lipid hydroperoxide) (PLHP) on the Fe₃O₄ surface, respectively, which were then assembled into vesicles containing two closely attached Fe₃O₄-Au NPs layers in opposite directions. The self-assembly mechanism of the bilayered vesicles was elucidated by performing a series of numerical simulations. The enhanced optical properties of the bilayered vesicles were verified by the calculated results and experimental data. The vesicles exhibited enhanced T₂ relaxivity and photoacoustic properties over single JNPs due to the interparticle magnetic dipole interaction and plasmonic coupling. In particular, the vesicles are pH responsive and disassemble into single JNPs in the acidic tumor environment, activating an intracellular biochemical reaction between the grafted PLHP and released ferrous ions (Fe²⁺) from Fe₃O₄ NPs, resulting in highly efficient local ROS generation and increased intracellular oxidative stress. In combination with the release of doxorubicin (DOX), the vesicles combine ROS-mediated cytotoxicity and DOX-induced chemotherapy, leading to greatly improved therapeutic efficacy than monotherapies. High tumor accumulation efficiency and fast vesicle clearance from the body were also confirmed by positron emission tomography (PET) imaging of radioisotope ⁶⁴Cu-labeled vesicles.

Investigation of the Roles of Plasma Species Generated by Surface Dielectric Barrier Discharge

As an emerging sterilization technology, cold atmospheric plasma offers a dry, non-thermal, rapid process that is minimally damaging to a majority of substrates. However, the mechanisms by which plasma interacts with living cells are poorly understood and the plasma generation apparatuses are complex and resource-intensive. In this study, the roles of reactive oxygen species (ROS), nitric oxide (NO), and charged particles (ions) produced by surface dielectric barrier discharge (SDBD) plasma on prokaryotic (Listeria monocytogenes (Gram-positive)) and eukaryotic (human umbilical vein endothelial cells (HUVEC)) cellular function were evaluated. HUVEC and bacterial oxidative stress responses, the accumulation of nitrite in aqueous media, air ion density, and bacterial inactivation at various distances from SDBD actuators were measured. SDBD actuator designs were also varied in terms of electrode number and length to evaluate the cellular effects of plasma volume and power distribution. NO and ions were found to contribute minimally to the observed cellular effects, whereas ROS were found to cause rapid bacterial inactivation, induce eukaryotic and prokaryotic oxidative stress, and result in rapid oxidation of bovine muscle tissue. The results of this study underscore the dominance of ROS as the major plasma generated species responsible for cellular effects, with ions and RNS having a secondary, complimentary role.

miR-330-3p promotes lung cancer cells invasion, migration, and metastasis by directly targeting hSOD2b

Lung cancer is a serious threat to human health. Studies have revealed that human manganese superoxide dismutase (hSOD2) and miRNAs play an essential role in the metastasis process of lung cancer. However, the miRNAs that associated with hSOD2 and involved in metastasis, remain elusive. After databases analysis and dual luciferase reporter validation, we demonstrated that miR-330-3p expression inversely correlated with hSOD2b expression level, and that miR-330-3p directly targeted the 3'untranslated region (3'UTR) of hSOD2b. Furthermore, overexpression of miR-330-3p promoted whereas knockdown of miR-330-3p inhibited invasion/migration and the epithelial-mesenchymal transition (EMT) process of lung cancer cells in vitro. Knockdown of miR-330-3p inhibited metastasis of lung cancer cells in vivo. Moreover, miR-330-3p-mediated enhancement of invasion/migration in 95-D cells could be rescued by over-expression of hSOD2. In conclusion, we demonstrated that miR-330-3p promoted metastasis of lung cancer cells by suppressing hSOD2b expression and unveiled a new clinical application of miR-330-3p in the therapy of lung cancer.

The Interaction of Selenium with Chemotherapy and Radiation on Normal and Malignant Human Mononuclear Blood Cells

Selenium, a trace element with anticancer properties, can reduce harmful toxicities of chemotherapy and radiotherapy without compromising efficacy. However, the dose-response relationship in normal versus malignant human cells is unclear. We evaluated how methylseleninic acid (MSA) modulates the toxicity and efficacy of chemotherapy and radiation on malignant and non-malignant human mononuclear blood cells in vitro. We specifically investigated its effects on endoplasmic reticulum stress induction, intracellular glutathione concentration, DNA damage and viability of peripheral blood mononuclear cells and THP1 monocytic leukaemia cells in response to radiation, cytosine arabinoside or doxorubicin chemotherapy. MSA, at lower concentrations, induced protective responses in normal cells but cytotoxic effects in malignant cells, alone and in conjunction with chemotherapy or radiation. However, in normal cells higher concentrations of MSA were directly toxic and increased the cytotoxicity of radiation but not chemotherapy. In malignant cells higher MSA concentrations were generally more effective in combination with cancer treatments. Thus, optimal MSA concentrations differed between normal and malignant cells and treatments. This work supports clinical reports that selenium can significantly reduce dose-limiting toxicities of anticancer therapies and potentially improve efficacy of anticancer treatments. The optimal selenium compound and dose is not yet determined.

Real time detection of glutathionse in chemotherapy squamous-cell carcinoma cells of a fluorescent probe

Glutathione (GSH) plays a key role in protecting damage induced by radiation and chemotherapy drugs. Current methods, which quantify GSH level changes by using cellular extraction or being based on redox homeostasis results, are unable to directly measure real time GSH level in live cells. In this article, we utilized a newly designed reversible fluorescent probe to measure GSH in living cells. The image of probe 1 can reveal intracellular GSH location and GSH level changes caused by different chemotherapy drugs in squamous-cell carcinoma cells. The results show that it is the first report with probe 1 that to quantify real-time GSH level changes in the cultured chemotherapy cancer cells and different changes in GSH level that may confer chemotherapy resistance.

Piperlongumine potentiates the effects of gemcitabine in in vitro and in vivo human pancreatic cancer models

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest cancers due to a late diagnosis and poor response to available treatments. There is a need to identify complementary treatment strategies that will enhance the efficacy and reduce the toxicity of currently used therapeutic approaches. We investigated the ability of a known ROS inducer, piperlongumine (PL), to complement the modest anti-cancer effects of the approved chemotherapeutic agent gemcitabine (GEM) in PDAC cells in vitro and in vivo. PDAC cells treated with PL + GEM showed reduced cell viability, clonogenic survival, and growth on Matrigel compared to control and individually-treated cells. Nude mice bearing orthotopically implanted MIA PaCa-2 cells treated with both PL (5 mg/kg) and GEM (25 mg/kg) had significantly lower tumor weight and volume compared to control and single agent-treated mice. RNA sequencing (RNA-Seq) revealed that PL + GEM resulted in significant changes in p53-responsive genes that play a role in cell death, cell cycle, oxidative stress, and DNA repair pathways. Cell culture assays confirmed PL + GEM results in elevated ROS levels, arrests the cell cycle in the G0/G1 phase, and induces PDAC cell death. We propose a mechanism for the complementary anti-tumor effects of PL and GEM in PDAC cells through elevation of ROS and transcription of cell cycle arrest and cell death-associated genes. Collectively, our results suggest that PL has potential to be combined with GEM to more effectively treat PDAC.

Antitumor activity of extract and isolated compounds from Drechslera rostrata and Eurotium tonophilum

Total extracts of Drechslera rostrata and Eurotium tonophilum in addition of two isolated compounds from their cultures [di-2-ethylhexyl phthalate (H1) and 1,8-Dihydroxy-3-methoxy-6-methyl-anthraquinone (H2)] were tested for their antitumor activity using four human carcinoma cell lines. Antitumor activity was assessed by performing MTT assay to check the % cell viability. The % viability of HCT-116 (colon carcinoma), HeLa (cervical carcinoma), HEp-2 (larynx carcinoma) and HepG-2 (hepatocellular carcinoma) cells decreased after treatment with Drechslera rostrata and Eurotium tonophilum extracts, these effects were ranged from 059.0 ±  0.1 to 217.0  ±  0.3 µg/ml on all types of cancer cells. The best activity was recorded for Eurotium tonpholium extract (054.5 ± 0.3, 059.0 ± 0.5 and 059.0 ± 0.1 for HEp-2, Hela, and HepG-2 respectively). The isolated compounds (H1&H2) were found to be responsible about the activities because they recorded the lowest IC₅₀ on tested cell lines with range of 9.5-20.3 μg/ml. Vinblastine sulphate was used as a reference standard and showed in vitro anticancer activity. This study demonstrated that all extracts and isolated compounds have antitumor activity against HCT-116, HeLa, HEp-2 and HepG-2 cells.

Oxidative stress-induced diseases and tea polyphenols

Reactive oxide species are the middle products of normal metabolism, and play a crucial role in cell signaling transduction. On the contrary, accumulation of excess reactive oxide species results in oxidative stress that often brings multifarious impairment to cells, including decrease of ATP level in cells, elevation of cytosolic Ca2+, DNA damage, dysfunction of biological function in lipid bilayer and so on. These effects will finally lead to all kinds of diseases. Tea polyphenols are widely considered as a kind of excellent antioxidant agents. It can be antioxidants by directly scavenging reactive oxide species or chelating transition metals, and indirectly upregulating the activity of antioxidant enzymes. In addition, tea polyphenols have also been observed a potent pro-oxidant capacity, which directly leads to the generation of reactive oxide species, and indirectly induces apoptosis and death of cancer cells. The underlying characters of its pro-oxidant activity in some diseases is not well understood. The present review we will discuss the dual character of tea polyphenols, both antioxidant and pro-oxidant properties, in some human diseases induced by oxidative stress.

Deciphering the molecular mechanism underlying anticancer activity of coumestrol in triple-negative breast cancer cells

Triple-negative breast cancer (TNBC) represents the highly aggressive subgroup of breast cancers with poor prognosis due to absence of estrogen receptor (ER). Therefore, alternative targeted therapies are required against ER-negative breast cancers. Coumestrol, a phytoestrogen inhibits cell growth of ER-negative breast cancer MDA-MB-231 cells; the exact mechanism has not yet been reported. Unlike normal cells, cancer cells contain elevated copper which play an integral role in angiogenesis. The current focus of the work was to identify any possible role of copper in coumestrol cytotoxic action against breast cancer MDA-MB-231 cells. Results demonstrated that coumestrol inhibited cell viability, induced ROS generation, DNA damage, G1/S cell cycle arrest, up-regulation of Bax and apoptosis induction via caspase-dependent mitochondrial mediated pathway in MDA-MB-231 cells. Further, addition of copper chelator, neocuproine and ROS scavenger, N-acetyl cysteine were ineffective in abrogating coumestrol-mediated apoptosis. This suggests non-involvement of copper and ROS in coumestrol-induced apoptosis. To account for coumestrol-mediated up-regulation of Bax and apoptosis induction, direct binding potential between coumestrol and Bax/Bcl-2 was studied using in silico molecular docking studies. We propose that coumestrol directly enters cells and combines with Bax/Bcl-2 to alter their structures, thereby causing Bax binding to the outer mitochondrial membrane and Bcl-2 release from the mitochondria to initiate apoptosis. Thus, non-copper targeted ROS independent DNA damage is the central mechanism of coumestrol in ER-negative MDA-MB-231 cells. These findings will be useful in better understanding of anticancer mechanisms of coumestrol and establishing it as a lead molecule for TNBC treatment.

Cold Atmospheric Plasma in the Treatment of Osteosarcoma

Human osteosarcoma (OS) is the most common primary malignant bone tumor occurring most commonly in adolescents and young adults. Major improvements in disease-free survival have been achieved by implementing a combination therapy consisting of radical surgical resection of the tumor and systemic multi-agent chemotherapy. However, long-term survival remains poor, so novel targeted therapies to improve outcomes for patients with osteosarcoma remains an area of active research. This includes immunotherapy, photodynamic therapy, or treatment with nanoparticles. Cold atmospheric plasma (CAP), a highly reactive (partially) ionized physical state, has been shown to inherit a significant anticancer capacity, leading to a new field in medicine called “plasma oncology.” The current article summarizes the potential of CAP in the treatment of human OS and reviews the underlying molecular mode of action.

Morin Inhibits Proliferation of SW480 Colorectal Cancer Cells by Inducing Apoptosis Mediated by Reactive Oxygen Species Formation and Uncoupling of Warburg Effect

The study under investigation focuses on in vitro antiproliferative efficacy of the flavonoid morin and the mechanisms by which it inhibits the growth of colon cancer using SW480 colon cancer cells with emphasis on Warburg effect. It was found that the cell proliferation was significantly inhibited by morin in a dose and time dependent manner. Morin induced apoptosis that was correlated with increased levels of reactive oxygen species formation and loss of mitochondrial membrane potential of the cells. In addition, an increase in cleaved PARP, cleaved caspase 3, cleaved caspase 8, cleaved caspase 9 and Bax as well as a decrease in Bcl 2 was observed, indicating morin is inducing both intrinsic as well as extrinsic pathway of apoptosis. This was further confirmed by using downstream caspase 3 inhibitor which indicated that caspase 3 inhibition reduces morin induced cell death. Moreover, the impact of morin on over all energy status when determined in terms of total cellular ATP level showed a decline with low level of glucose uptake and Glut1 expression. The results indicate that morin exerts antiproliferative activity by inducing apoptosis and by reducing Warburg effect in the evaluated cell lines and provide preliminary evidence for its anticancer activity.

Integrated Nanoparticles To Synergistically Elevate Tumor Oxidative Stress and Suppress Antioxidative Capability for Amplified Oxidation Therapy

The improved antioxidant system of cancer cells renders them well-adaptive to the intrinsic oxidative stress in tumor tissues. On the other hand, cancer cells are more sensitive to elevated tumor oxidative stress as compared with normal cells due to their deficient reactive oxygen species-eliminating systems. Oxidation therapy of cancers refers to the strategy of killing cancer cells through selectively increasing the oxidative stress in tumor tissues. In this article, to amplify the oxidation therapy, we develop integrated nanoparticles with the properties to elevate tumor oxidative stress and concurrently suppress the antioxidative capability of cancer cells. The amphiphilic block copolymer micelles of poly(ethylene glycol)-b-poly[2-((((4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzyl)oxy)carbonyl)oxy)ethyl methacrylate] (PEG-b-PBEMA) are integrated with palmitoyl ascorbate (PA) to form hybrid micelles (PA-Micelle). PA molecules at pharmacologic concentrations serve as a prooxidant to upregulate the hydrogen peroxide (H₂O₂) level in tumor sites and the PBEMA segment exhibits H₂O₂-triggered release of quinone methide for glutathione depletion to suppress the antioxidative capability of cancer cells, which synergistically and selectively kill cancer cells for tumor growth suppression. Given the significantly low side toxicity against normal tissues, this novel integrated nanoparticle design represents a novel class of nanomedicine systems for high-efficiency oxidation therapy with the potentials to be translated to clinical applications.

ROS-modulated therapeutic approaches in cancer treatment

PURPOSE

Reactive oxygen species (ROS) are produced in cancer cells as a result of increased metabolic rate, dysfunction of mitochondria, elevated cell signaling, expression of oncogenes and increased peroxisome activities. Certain level of ROS is required by cancer cells, above or below which lead to cytotoxicity in cancer cells. This biochemical aspect can be exploited to develop novel therapeutic agents to preferentially and selectively target cancer cells.

METHODS

We searched various electronic databases including PubMed, Web of Science, and Google Scholar for peer-reviewed english-language articles. Selected articles ranging from research papers, clinical studies, and review articles on the ROS production in living systems, its role in cancer development and cancer treatment, and the role of microbiota in ROS-dependent cancer therapy were analyzed.

RESULTS

This review highlights oxidative stress in tumors, underlying mechanisms of different relationships of ROS and cancer cells, different ROS-mediated therapeutic strategies and the emerging role of microbiota in cancer therapy.

CONCLUSION

Cancer cells exhibit increased ROS stress and disturbed redox homeostasis which lead to ROS adaptations. ROS-dependent anticancer therapies including ROS scavenging anticancer therapy and ROS boosting anticancer therapy have shown promising results in vitro as well as in vivo. In addition, response to cancer therapy is modulated by the human microbiota which plays a critical role in systemic body functions.

Selective Targeting of Cancer Cells by Oxidative Vulnerabilities with Novel Curcumin Analogs

Recently, research has focused on targeting the oxidative and metabolic vulnerabilities in cancer cells. Natural compounds like curcumin that target such susceptibilities have failed further clinical advancements due to the poor stability and bioavailability as well as the need of high effective doses. We have synthesized and evaluated the anti-cancer activity of several monocarbonyl analogs of curcumin. Interestingly, two novel analogs (Compound A and I) in comparison to curcumin, have increased chemical stability and have greater anti-cancer activity in a variety of human cancer cells, including triple-negative, inflammatory breast cancer cells. In particular, the generation of reactive oxygen species was selective to cancer cells and occurred upstream of mitochondrial collapse and execution of apoptosis. Furthermore, Compound A in combination with another cancer-selective/pro-oxidant, piperlongumine, caused an enhanced anti-cancer effect. Most importantly, Compound A was well tolerated by mice and was effective in inhibiting the growth of human triple-negative breast cancer and leukemia xenografts in vivo when administered intraperitoneally. Thus, exploiting oxidative vulnerabilities in cancer cells could be a selective and efficacious means to eradicate malignant cells as demonstrated by the curcumin analogs presented in this report with high therapeutic potential.