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

Engineering of 2D transition metal carbides and nitrides MXenes for cancer therapeutics and diagnostics

The 2D layered structured material with unique surface terminations and properties have showed great potential in variety of biomedical research fields including drug delivery and cancer therapeutics which forms the major focus of this review. MXenes as a multifunctional two-dimensional (2D) nanomaterial, has also received momentous research interest in oncology resulting from its intriguing structure and fascinating properties of magnetism and photodynamic properties such as luminescent, conductivity, magnetism, non-toxicity and its bio compatibility. This reported review intends to cover exclusively the synthesis and utilization of MXenes in oncological applications, and subsequently its future outlook in cancer therapeutic, diagnostic and theranostics. The versatile and unique physio-chemistry of MXenes permits fine tuning of its properties towards oncological applications ranging from the cancer therapeutic (e.g., photothermal therapy, photodynamic therapy, radiation therapy, chemotherapy) to cancer imaging (e.g., CT/MRI/PA imaging) as well as cancer theranostic applications. We have started the discussion by portraying the broad picture of physio-chemical aspects of MXenes followed by its drug delivery functionalities. Subsequently, ROS mediated therapeutic strategies of photodynamic therapy and radiotherapy as well as light triggered functionalities of MXenes were detailed comprehensively. In the middle of the gallery, various imaging and sensing aspects of MXenes were elucidated. Finally, we have concluded by explaining the combined therapy and diagnostic functions (theranostics) of MXenes. To put it in perspective, the current challenges and new opportunities in MXenes also discussed will give great realistic insights to motivate further research in realizing MXene as an intelligent oncological tool.

The mystery of mitochondria-ER contact sites in physiology and pathology: A cancer perspective

Mitochondria-associated membranes (MAM), physical platforms that enable communication between mitochondria and the endoplasmic reticulum (ER), are enriched with many proteins and enzymes involved in several crucial cellular processes, such as calcium (Ca²⁺) homeostasis, lipid synthesis and trafficking, autophagy and reactive oxygen species (ROS) production. Accumulating studies indicate that tumor suppressors and oncogenes are present at these intimate contacts between mitochondria and the ER, where they influence Ca²⁺ flux between mitochondria and the ER or affect lipid homeostasis at MAM, consequently impacting cell metabolism and cell fate. Understanding these fundamental roles of mitochondria-ER contact sites as important domains for tumor suppressors and oncogenes can support the search for new and more precise anticancer therapies. In the present review, we summarize the current understanding of basic MAM biology, composition and function and discuss the possible role of MAM-resident oncogenes and tumor suppressors.

Akkermansia muciniphila Aspartic Protease Amuc_1434* Inhibits Human Colorectal Cancer LS174T Cell Viability via TRAIL-Mediated Apoptosis Pathway

Mucin2 (Muc2) is the main component of the intestinal mucosal layer and is highly expressed in mucous colorectal cancer. Previous studies conducted by our lab found that the recombinant protein Amuc_1434 (expressed in Escherichia coli prokaryote cell system, hereinafter termed Amuc_1434*), derived from Akkermansia muciniphila, can degrade Muc2. Thus, the main objective of this study was to explore the effects of Amuc_1434* on LS174T in colorectal cancer cells expressing Muc2. Results from this study demonstrated that Amuc_1434* inhibited the proliferation of LS174T cells, which was related to its ability to degrade Muc2. Amuc_1434* also blocked the G0/G1 phase of the cell cycle of LS174T cells and upregulated the expression of tumor protein 53 (p53), which is a cell cycle-related protein. In addition, Amuc_1434* promoted apoptosis of LS174T cells and increased mitochondrial ROS levels in LS174T cells. The mitochondrial membrane potential of LS174T cells was also downregulated by Amuc_1434*. Amuc_1434* can activate the death receptor pathway and mitochondrial pathway of apoptosis by upregulating tumor-necrosis-factor-related apoptosis-inducing ligand (TRAIL). In conclusion, our study was the first to demonstrate that the protein Amuc_1434* derived from Akkermansia muciniphila suppresses LS174T cell viability via TRAIL-mediated apoptosis pathway.

The Double-Faced Role of Nitric Oxide and Reactive Oxygen Species in Solid Tumors

Disturbed redox homeostasis represents a hallmark of cancer phenotypes, affecting cellular metabolism and redox signaling. Since reactive oxygen and nitrogen species (ROS/RNS) are involved in regulation of proliferation and apoptosis, they may play a double-faced role in cancer, entailing protumorigenic and tumor-suppressing effects in early and later stages, respectively. In addition, ROS and RNS impact the activity and communication of all tumor constituents, mediating their reprogramming from anti- to protumorigenic phenotypes, and vice versa. An important role in this dichotomic action is played by the variable amounts of O₂ in the tumor microenvironment, which dictates the ultimate outcome of the influence of ROS/RNS on carcinogenesis. Moreover, ROS/RNS levels remarkably influence the cancer response to therapy. The relevance of ROS/RNS signaling in solid tumors is witnessed by the emergence of novel targeted treatments of solid tumors with compounds that target ROS/RNS action and production, such as tyrosine kinase inhibitors and monoclonal antibodies, which might contribute to the complexity of redox regulation in cancer. Prospectively, the dual role of ROS/RNS in the different stages of tumorigenesis through different impact on oxidation and nitrosylation may also allow development of tailored diagnostic and therapeutic approaches.

The role and function of PPARγ in bladder cancer

Peroxisome proliferator-activated receptor gamma (PPARγ), a member of the nuclear receptor superfamily, participates in multiple physiological and pathological processes. Extensive studies have revealed the relationship between PPARγ and various tumors. However, the expression and function of PPARγ in bladder cancer seem to be controversial. It has been demonstrated that PPARγ affects the occurrence and progression of bladder cancer by regulating proliferation, apoptosis, metastasis, and reactive oxygen species (ROS) and lipid metabolism, probably through PPARγ-SIRT1 feedback loops, the PI3K-Akt signaling pathway, and the WNT/β-catenin signaling pathway. Considering the frequent relapses after chemotherapy, some researchers have focused on the relationship between PPARγ and chemotherapy sensitivity in bladder cancer. Moreover, the feasibility of PPARγ ligands as potential therapeutic targets for bladder cancer has been uncovered. Taken together, this review summarizes the relevant literature and our findings to explore the complicated role and function of PPARγ in bladder cancer.

Mycoremediation: Expunging environmental pollutants

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Mycoremediation of polycyclic aromatic hydrocarbons, challenges, and strategies to overcome.

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Role of the fungi in eradicating heavy metal contamination from the polluted sites.

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Mycoremediation of agricultural wastes including pesticides, herbicides, and cyanotoxins.

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Pharmaceutical wastes and strategies for its remediation using white-rot and ligninolytic fungus.

The ever-increasing population, rapid rate of urbanization, and industrialization are exacerbating the pollution-related problems. Soil and water pollution affect human health and the ecosystem. Thus, it is crucial to develop strategies to combat this ever-growing problem. Mycoremediation, employing fungi or its derivatives for remediation of environmental pollutants, is a comparatively cost-effective, eco-friendly, and effective method. It has advantages over other conventional and bioremediation methods. In this review, we have elucidated the harmful effects of common pollutants on public health and the environment. The role of several fungi in degrading these pollutants such as heavy metals, agricultural, pharmaceutical wastes, including polycyclic aromatic hydrocarbons, is enumerated. Future strategies to improve the rate and efficiency of mycoremediation are suggested. The manuscript describes the strategies which can be used as a future framework to address the global problem of pollution.

Anti-Tumor Mechanisms of Novel 3-(4-Substituted Benzyl)-5-Isopropil-5- Phenylhydantoin Derivatives in Human Colon Cancer Cell Line

BACKGROUND

Hydantoin and its newly synthesized derivatives have recently become a focus of interest due to their numerous biological activities and newly emerging beneficial effects in different pathological conditions, including cancer.

OBJECTIVE

The aim of this study was to evaluate the possible anti-tumor mechanisms of a series of newly synthesized 3-(4-substituted benzyl)-5-isopropyl-5-phenylhydantoin derivatives in different aspects of cell physiology of human colon cancer cell line, HCT-116.

METHODS

The increasing concentrations of derivatives (0.01µM up to 100µM) were applied to cells during 24h, 48h, and 72h after which the evaluation of proliferation, apoptosis, oxidative/anti-oxidative status, nitrite production, and migration/invasion potential of treated cells was performed.

RESULTS

All tested compounds expressed the dose- and time-dependent anti-proliferative and pro-apoptotic activities against HCT-116 cells. The investigated derivatives induced a decrease in levels of oxidative stress parameters and an increase in levels of nitrite production by treated cells suggesting their significant antioxidative effects. The cell migration index and expression level of tumor invasion-promoting metalloproteinase- 9 (MMP-9) gene were significantly decreased after treatment with the tested hydantoin derivatives implicating their inhibitory role in colon cancer cell motility and invasion processes. The mRNA level of cyclooxygenase-2 (COX-2) gene as a pro-inflammatory gene related to colorectal carcinogenesis was reduced compared to values in the non-treated control cells indicating the significant anti-inflammatory/anti-tumor effects of these compounds.

CONCLUSION

The obtained results show the significant anti-tumor potential of tested derivatives, especially 3- benzyl-5-isopropyl-5-phenylhydantoin and 3-(4-chlorobenzyl)-5-isopropyl-5-phenylhydantoin, suggesting their potential usage in the development of more effective chemotherapies.

Andrographolide induces apoptosis in human osteosarcoma cells via the ROS/JNK pathway

Osteosarcoma is the most common primary malignant tumor of the bone and the long-term survival of patients with this disease has remained unsatisfactory over the past several decades. Andrographolide, a traditional drug used in Chinese medicine, has been found to exert a significant antitumor effect against several types of cancer. However, relatively little is known about the effect of andrographolide on osteosarcoma and the underlying mechanisms. In the present study, it was shown that andrographolide inhibited osteosarcoma cell proliferation by arresting the cell cycle at the G2/M phase and increasing caspase-mediated apoptosis. Furthermore, treatment with andrographolide induced JNK activation and increased production of reactive oxygen species (ROS). The andrographolide-triggered apoptosis in osteosarcoma cells was partly abrogated by a JNK inhibitor and completely reversed by a ROS scavenger. Additionally, JNK activation and cell cycle arrest at the G2/M phase were prevented by administration of an ROS scavenger. In vivo, it was also found that andrographolide inhibited tumor growth by increasing the levels of ROS and activating JNK; thus inducing cytotoxicity in primary osteosarcoma cells. Together, the results of the present study suggest that andrographolide caused G2/M arrest and induced cell apoptosis via regulation of the ROS/JNK signaling pathway in osteosarcoma cells. Thus, andrographolide may serve as a promising antitumor therapeutic agent against osteosarcoma.

Cyanidin Chloride Induces Apoptosis by Inhibiting NF-κB Signaling through Activation of Nrf2 in Colorectal Cancer Cells

Colorectal cancer (CRC) is the third most common cancer worldwide and a leading cause of cancer-related deaths in developed countries. Anthocyanins are a class of flavonoids, widely distributed in food, exhibiting important biological effects. Cyanidin chloride (CyCl) is the common type of anthocyanin with antioxidative and anti-inflammatory potential. The present study aimed to investigate the molecular mechanisms underlying the chemotherapeutic effects of CyCl in colorectal cancer cells. We found that CyCl treatment induced apoptosis as well as a significant inhibition of cellular proliferation and colony formation in three colon cancer HCT116, HT29, and SW620 cells. In addition, CyCl suppressed nuclear factor-kappa B (NF-κB) signaling and induced the activation of the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway in tumor necrosis factor-alpha (TNF-α)-stimulated colon cancer cells. Nrf2 and NF-κB are two key transcription factors regulating antioxidative responses and cellular proliferation, respectively. In this study, knockdown of Nrf2 by small interfering RNA (siRNA) transfection inhibited the effect of CyCl on NF-κB signaling and apoptosis, suggesting that there is functional crosstalk between Nrf2 and NF-κB. Our findings demonstrate the important role of Nrf2 in inducing apoptosis through the involvement of NF-κB signaling in colorectal cancer cells, suggesting that CyCl may be used as a potential therapeutic agent for CRC.

Soy Metabolism by Gut Microbiota from Patients with Precancerous Intestinal Lesions

BACKGROUND

Colorectal cancer (CRC) requires the presence of a variety of factors predisposing a tumorigenic milieu. Excluding familial clustering and hereditary CRC syndromes, the development of sporadic CRC from precancerous lesions is influenced by tissue inflammation, modulation of intestinal immunity, hormones, dietary habits and gut microbiota composition. As concerning the last two aspects, the intestinal presence of equol, the most biologically active metabolite of the soy isoflavone daidzein and the presence of a genetic determinant of gut microbiota able to metabolize daidzein, seem to lower the CRC risk. It has been hypothesized that the anaerobic microorganisms of the Bacteroides genus play a role in equol production.

AIM

To evaluate the presence of (i) anaerobic gut microbiota and (ii) the urinary levels of soy isoflavones (daidzein, genistein and equol) in patients with and without precancerous lesions, challenged with a daidzein-rich soy extract.

METHODS

Consecutive subjects undergoing colonoscopy participated to the study. Feces were collected from all patients one week before colonoscopy for gut microbiota studies. After the endoscopy examination and the histological evaluation, 40 subjects, 20 with sporadic colorectal adenomas (SCA/P group) and 20 without proliferative lesions (control group) were enrolled for the study. Urine levels of soy isoflavones daidzein, genistein and their metabolite equol, were determined by high performance liquid chromatographic (HPLC) analysis and gut microbiota analysis was performed by Matrix Assisted Laser Desorption Ionization Time of Flight Mass Spectrometry (MALDI-TOF MS) procedure.

RESULTS

Seventeen different bacterial species were identified in the fecal samples of the forty subjects participating to the study. Ten bacterial species resulted anaerobic Gram-negative bacteria, all belonging to the Bacteroides genus. A significant difference of bacteria species was evidenced in the fecal samples of the two groups of subjects. Particularly important was the evidence of Parabacteroides distasonis, Clostridium clostridioforme and Pediococcus pentasaceus only in control fecal samples, such as the presence of Bacteroides fragilis and Prevotella melaningenica only in SCA/P fecal samples. Concerning the soy isoflavones levels, no statistically significant differences were revealed in the genistein and daidzein urinary levels between the two groups of subjects. On the contrary, urinary equol levels were undetectable in ten SCA/P subjects and in two controls; moreover, when present, the levels of urinary equol were significantly lower in SCA/P subjects compared to controls (0.24 ± 0.27 mg/24 hrs vs. 21.25 ± 4.3 mg/24 hrs, respectively, p = 1.12 × 10^-6).

CONCLUSIONS

Our results suggest that the presence of anaerobic Bacteroides in the colon, and the production of equol from soy, could determine a milieu able to contrast the development of colonic mucosa proliferative lesions.

Combining Tumor Microenvironment Modulating Nanoparticles with Doxorubicin to Enhance Chemotherapeutic Efficacy and Boost Antitumor Immunity

BACKGROUND

Tumor microenvironment (TME) and associated multiple factors are found to contribute to the failures in cancer therapies, including chemo- and immunotherapy. Here we report a new multimodal strategy that uses a bioreactive multifunctional hybrid polymer-lipid encapsulated manganese dioxide nanoparticle (PLMD NP) system to remodel the TME, suppress drug resistance factors, reverse immunosuppressive conditions, and enhance chemotherapy efficacy.

METHODS

The influence of PLMD NPs on enhancing cellular uptake in EMT6 mouse breast cancer cells and tumor penetration of doxorubicin (DOX) in EMT6 orthotopic breast tumor mouse model was evaluated using confocal microscopy (n = 3-4). Immunohistochemistry was employed to examine the effect of PLMD NPs on downregulating hypoxia-induced drug resistance proteins and anticancer activity of DOX (n = 3-4). The efficacy of the combination therapy with PLMD NPS and DOX was assessed in murine EMT6 (n = 15-23) and 4T1 (n = 7) orthotopic breast tumor mouse models. Rechallenge and splenocyte transfer were performed to validate the stimulation of adaptive tumor immunity in the surviving mice.

RESULTS

PLMD NPs enhanced intratumoral penetration and efficacy of DOX, and reduced intratumoral expression of P-glycoprotein, p53, and carbonic anhydrase IX by 74.5%, 38.0%, and 58.8% vs saline control, respectively. Combination treatment with PLMD NPs and DOX increased the number of tumor-infiltrated CD8+ T cells and resulted in up to 60.0% complete tumor regression. Of naïve mice (n = 7) that received splenocytes from the PLMD+DOX-treated surviving mice, 57.1% completely suppressed tumor growth whereas 100% of mice that received splenocytes from DOX-treated mice (n = 3) and the control group (n = 7) showed rapid tumor growth.

CONCLUSIONS

The clinically suitable PLMD NPs can effectively downregulate TME-associated drug resistance and immunosuppression. The combination therapy with PLMD NPs and DOX is a multimodal and translational treatment approach for enhancing chemotherapeutic efficacy and boosting antitumor immunity.

Clinico-pathological significance of Drp1 dysregulation and its correlation to apoptosis in oral cancer patients

Dysregulation in mitochondrial dynamics has been associated with several diseases including cancer. Present study assessed the alteration in mitochondrial fission protein (Drp1) in oral epithelial cells collected from clinically confirmed pre-cancer and cancer patients and further correlates it with the cellular apoptosis signaling. Results indicate the ROS accumulation in OSCC patients is accompanied by several changes including increase in mitochondrial mass, expression of mitochondrial fission protein (Drp1) and alteration in apoptotic signaling. The positive co-relation has been observed between the expressions of anti-apoptotic Bcl-2proteinswith mitochondrial fission protein Drp1. Higher mitochondrial fission in oral cancer cells was also correlated with the increased expression of cell cycle marker CyclinD1 indicating highly proliferative stage of oral cancer cells. The clinical correlation can be extended to develop biomarker for diagram and program in oral cancer management.

The role of transporters in cancer redox homeostasis and cross-talk with nanomedicines

Tumor cell usually exhibits high levels of reactive oxygen species and adaptive antioxidant system due to the metabolic, genetic, and microenvironment-associated alterations. The altered redox homeostasis can promote tumor progression, development, and treatment resistance. Several membrane transporters are involved in the resetting redox homeostasis and play important roles in tumor progression. Therefore, targeting the involved transporters to disrupt the altered redox balance emerges as a viable strategy for cancer therapy. In addition, nanomedicines have drawn much attention in the past decades. Using nanomedicines to target or reset the redox homeostasis alone or combined with other therapies has brought convincing data in cancer treatment. In this review, we will introduce the altered redox balance in cancer metabolism and involved transporters, and highlight the recent advancements of redox-modulating nanomedicines for cancer treatment.

The benefits of ascorbate to protect healthy cells in the prevention and treatment of oncological diseases

Health status is determined by the balance of oxidants and antioxidants which protects healthy cells against the threat of internal and external risk factors. Antioxidants such as ascorbate (vitamin C, ascorbic acid) are of fundamental importance in this respect. Ascorbate neutralizes potential damage caused by cellular oxidative stress which may be the greatest risk of damage to healthy tissue. Cellular oxidative stress is mediated by external factors (e.g. psychological stress, physical exertion, drugs, various diseases, environmental pollution, preservatives, smoking, and alcohol) and internal factors (products of cellular metabolism including reactive oxygen species). When the products of oxidative stress are not sufficiently neutralized, healthy cells are at risk for both mitochondrial and DNA damage. In the short term, cell function may deteriorate, while an increased production of proinflammatory cytokines over time may lead to the development of chronic inflammatory changes and diseases, including cancer. Although pharmaceutical research continues to bring effective chemotherapeutic agents to the market, a limiting factor is often the normal tissue and organ toxicity of these substances, which leads to oxidative stress on healthy tissue. There is increasing interest and imperative to protect healthy tissues from the negative effects of radio-chemotherapeutic treatment. The action of ascorbate against the development of oxidative stress may justify its use not only in the prevention of carcinogenesis, but as a part of supportive or complementary therapy during treatment. Ascorbate (particularly when administered parentally at high doses) may have antioxidant effects that work to protect healthy cells and improve patient tolerability to some toxic radio-chemotherapy regimens. Additionally, ascorbate has demonstrated an immunomodulatory effect by supporting mechanisms essential to anti-tumor immunity. Intravenous administration of gram doses of vitamin C produce high plasma levels immediately, but the levels drop rapidly. Following oral vitamin C administration, plasma levels increase slowly to relatively low values, and then gradually decay. With an oral liposomal formulation, significantly higher levels are attainable than with standard oral formulations. Therefore, oral administration of liposomal vitamin C appears to be an optimal adjunct to intravenous administration. In this review, the basic mechanisms and clinical benefits of ascorbate as an antioxidant that may be useful as complementary therapy to chemotherapeutic regimens will be discussed.

Synthesis of novel caffeic acid derivatives and their protective effect against hydrogen peroxide induced oxidative stress via Nrf2 pathway

AIM

This study was aimed to synthesize novel caffeic acid derivatives and evaluate their potential applications for the treatment of oxidative stress associated disease.

MAIN METHODS

Caffeic acid sulfonamide derivatives were synthesized by coupling sulfonamides to the backbone of caffeic acid and fully characterized by melting point test, FT-IR, MS, NMR, UV-vis and n-octanol-water distribution assay. Their free radical scavenging ability was evaluated using DPPH assay and cytotoxicity against A549 cells were determined by MTT assay. The protective effect of these derivatives against hydrogen peroxide (H₂O₂) induced oxidative injury was assessed in A549 cells from cell viability, production of reactive oxygen species (ROS) and malondialdehyde (MDA), alternation of antioxidase activities, and expressions of Nrf2 and its target genes.

KEY FINDINGS

Six novel caffeic acid sulfonamide derivatives were obtained. The derivatives showed better liphophilicity than the parent caffeic acid. CASMZ, CAST and CASQ exhibited similar DPPH scavenging capability as caffeic acid, while the protection of hydroxyl groups on the benzene ring with acetyl groups caused decrease in radical scavenging activity. No inhibitory effect on the proliferation of A549 cells were observed up to a concentration of 50 μM. Pre-treatment of cells with these derivatives strongly inhibited H₂O₂ induced decrease of cell viability, reduced the production of ROS and MDA, promoted antioxidase activities, and further upregulated the expression of Nrf2 and its target genes.

SIGNIFICANCE

Caffeic acid sulfonamide derivatives were synthesized with simple reactions under mild conditions. They might protect cells from H₂O₂-induced oxidative injury via Nrf2 pathway.

Smart Sorting of Tumor Phenotype with Versatile Fluorescent Ag Nanoclusters by Sensing Specific Reactive Oxygen Species

Reactive oxygen species (ROS) play a crucial role in cancer formation and development, especially cancer metastasis. However, lack of a precise tool, which could accurately distinguish specific types of ROS, restricts an in-depth study of ROS in cancer development and progression. Herein, we designed smart and versatile fluorescent Ag nanoclusters (AgNCs) for sensitive and selective detection of different species of ROS in cells and tissues.

Methods: Firstly, dual-emission fluorescent AgNCs was synthesized by using bovine serum albumin (BSA) to sense different types of ROS (H₂O₂, O2•-, •OH). The responsiveness of the AgNCs to different species of ROS was explored by fluorescence spectrum, hydrodynamic diameter, and so on. Furthermore, dual-emission fluorescent AgNCs was used to sense ROS in tumor with different degrees of differentiation. Finally, the relationship between specific types of ROS and tumor cell invasion was explored by cell migration ability and the expression of cell adhesion and EMT markers.

Results: This dual-emission fluorescent AgNCs possessed an excellent ability to sensitively and selectively distinguish highly reactive oxygen species (hROS, including O₂•^-and •OH) from moderate reactive oxygen species (the form of H₂O₂), and exhibited no fluoresence and green fluorescence, respectively. The emission of AgNCs is effective in detecting cellular and tissular ROS. When cultured with AgNCs, malignant tumor cells exhibit non-fluorescence, while the benign tumor emits green and reduced red light and the normal cells appear in weak green and bright red fluorescence. We further verified that not just H₂O₂ but specific species of ROS (O₂•^-and •OH) were involved in cell invasion and malignant transformation. Our study warrants further research on the role of ROS in physiological and pathophysiological processes.

Conclusion: Taken together, AgNCs would be a promising approach for sensing ROS, and offer an intelligent tool to detect different kinds of ROS in tumors.

Antioxidation of 2-phenylbenzofuran derivatives: structural-electronic effects and mechanisms

Stilbenoid-type 2-phenylbenzofuran derivatives, which are widely distributed in nature, are now promising antioxidant agents. In the present study, a quantum computational approach principally based on the DFT/B3LYP method with the 6-311++G(d,p) basis set was used to shed light on free radical scavenging for the isolated compounds stemofurans A-K and S-W. On the basis of the findings and from a thermodynamic perspective, the antioxidant activity of all studied compounds in the gaseous phase was mostly controlled by the O-H bond dissociation enthalpy (BDE), consistent with the hydrogen atom transfer (HAT) mechanism. The solvent effect was investigated, and the hydroxyl radicals of these studied compounds possessed the lowest proton affinity (PA) enthalpy and the sequential proton loss electron transfer (SPLET) pathway occurred in water, methanol and acetone. The studied compounds interacted with DPPH radicals, which is kinetic evidence of the involvement of two intermediates and one transition state. From both thermodynamics and kinetics perspectives, it can be proposed that stemofuran U is likely to be a leader compound in antioxidant drug development due to the presence of a 4'-OH moiety. Regarding the structure-bioactivity relationship, methylation can lead to a decrease in BDE.

Decylubiquinone suppresses breast cancer growth and metastasis by inhibiting angiogenesis via the ROS/p53/ BAI1 signaling pathway

Breast cancer is one of the most common cancers worldwide with a rising incidence, and is the leading cause of cancer-related death among females. Angiogenesis plays an important role in breast cancer growth and metastasis. In this study, we identify decylubiquinone (DUb), a coenzyme Q₁₀ analog, as a promising anti-breast cancer agent through suppressing tumor-induced angiogenesis. We screened a library comprising FDA-approved drugs and found that DUb significantly inhibits blood vessel formation using in vivo chick embryo chorioallantoic membrane (CAM) and yolk sac membrane (YSM) models. DUb was further identified to inhibit angiogenesis in the rat aortic ring and Matrigel plug assay. Moreover, DUb was found to suppress breast cancer growth and metastasis in the MMTV-PyMT transgenic mouse and human xenograft tumor models. To explore whether the anticancer efficacy of DUb was directly corrected with tumor-induced angiogenesis, the MDA-MB-231 breast cancer assay on the CAM was performed. Interestingly, DUb significantly inhibits the angiogenesis of breast cancer on the CAM. Brain angiogenesis inhibitor 1 (BAI1), a member of the G protein-coupled receptor (GPCR) adhesion subfamily, has an important effect on the inhibition of angiogenesis. Further studies demonstrate that DUb suppresses the formation of tubular structures by regulating the reactive oxygen species (ROS)/p53/BAI1 signaling pathway. These results uncover a novel finding that DUb has the potential to be an effective agent for the treatment of breast cancer by inhibiting tumor-induced angiogenesis.

Icariin sensitizes human colon cancer cells to TRAIL‑induced apoptosis via ERK‑mediated upregulation of death receptors

Tumor necrosis factor‑associated apoptosis‑inducing ligand (TRAIL) is considered to be a potential therapeutic target for various types of cancer. However, colon cancer is difficult to treat due to its resistance to TRAIL. Therefore, various trials have been conducted to overcome TRAIL resistance in colon cancer. The present study aimed to determine whether icariin (ICA) may sensitize human colon cancer cells to TRAIL‑induced apoptosis in vitro and in vivo. In the investigation of the effect of ICA on TRAIL‑induced apoptosis, the LIVE/DEAD assay results demonstrated that TRAIL plus ICA synergistically induced apoptosis in 49% of HCT116 colon cancer cells. These results were confirmed using long‑term colony formation assay. ICA potentiated TRAIL‑induced apoptosis by modulating the expression of apoptotic proteins and the induction of cell surface death receptors (DRs) 4 and 5. Upregulation of DRs by ICA was also observed at the transcriptional level by RT‑PCR. The expression of DR by ICA was increased through the production of reactive oxygen species (ROS). The results also suggested that increased expression of DR by ICA may be due to the activation of ERK and induction of the transcription factor CCAAT enhancer‑binding protein homologous protein (CHOP). NAC, a ROS scavenger, reduced the effect of ICA on ERK activation, DR induction and sensitization of TRAIL‑induced apoptosis. In addition, ICA enhanced the effects of TRAIL to reduce tumor growth in an in vivo xenograft mouse model. Overall, the present study provided evidence that ICA sensitized tumor cells to TRAIL‑induced apoptosis via ROS‑, ERK‑ and CHOP‑mediated upregulation of DR5 and DR4. Based on these results, it is suggested that the antitumor activity of ICA and TRAIL co‑treatment in vitro and in vivo may be used as an effective therapeutic agent in chemotherapy.

6-Formyl-5-isopropyl-3-hydroxymethyl- 7-methyl-1H-indene mitigates methamphetamine-induced photoreceptor cell toxicity through inhibiting oxidative stress

As an extremely addictive psychostimulant drug and an illicit dopaminergic neurotoxin, methamphetamine (METH) conducts to enhance satisfaction, feelings of alertness through influencing monoamine neurotransmitter systems. Long-lasting exposure to METH causes psychosis and increases the risk of neurodegeneration. 6-Formyl-5-isopropyl-3-hydroxymethyl-7-methyl-1H-indene (FIHMI) is a novel compound with potent antioxidant properties. This study was to investigate whether FIHMI could mitigate METH-induced photoreceptor cell toxicity. METH-caused cell toxicity was established in 661W cells and protective effects of FIHMI at different concentrations (1-10 µM) was examined. FIHMI significantly attenuated the METH-caused cell damage in 661W cells, evidenced by increasing cell viability and mitochondrial membrane potential, decreasing cytochrome c release and DNA fragmentation, inhibiting activities of caspase 3/9, and changing expression of apoptosis-related protein. Furthermore, FIHMI treatment decreased mRNA expression of Beclin-1 and LC3B protein expression in METH-induced 661W cells suggesting autophagy is reduced. FIHMI decreased the oxidative stress through increasing protein expression of nuclear factor (erythroid-derived 2)-like 2. These data demonstrated FIHMI could inhibit oxidative stress, which may also play an essential role in the regulation of METH-triggered apoptotic response, providing the scientific rational to develop FIHMI as the therapeutic agent to alleviate METH-induced photoreceptor cell toxicity.

Dancing with reactive oxygen species generation and elimination in nanotheranostics for disease treatment

Reactive oxygen species (ROS) play important roles in cell signaling and tissue homeostasis, in which the level of ROS is critical through the equilibrium between ROS generating and eliminating events. A disruption of the balance leads to disease development either by a surplus or a dearth of ROS, which requires ROS-modulating strategies to overturn the defect for disease treatment. Over the past decade, there have been tremendous advances in nanomedicine centering ROS generation and/or elimination as major mechanisms to treat a variety of diseases. In this review, we will discuss the research achievements on two opposite approaches of ROS-generating and ROS-eliminating strategies for treating cancer and other related diseases. Importantly, we will highlight the conceptual and strategic advances of ROS-mediated immunomodulation, including macrophage polarization, immunogenic cell death and T cell activation, which are currently rising as one of the mainstreams of cancer therapy. At the end, the future challenges and opportunities of mediating ROS-based mechanisms are envisioned. In light of the pleiotropic roles of ROS in different diseases, we hope this review is timely to deliver a clear logic of designing principles on ROS generation and elimination for different disease treatments.

Phenotypic alterations in liver cancer cells induced by mechanochemical disruption

Hepatocellular carcinoma (HCC) is a highly fatal disease recognized as a growing global health crisis worldwide. Currently, no curative treatment is available for early-to-intermediate stage HCC, characterized by large and/or multifocal tumors. If left untreated, HCC rapidly progresses to a lethal stage due to favorable conditions for metastatic spread. Mechanochemical disruption of cellular structures can potentially induce phenotypic alterations in surviving tumor cells that prevent HCC progression. In this paper, HCC response to mechanical vibration via high-intensity focused ultrasound and a chemical disruptive agent (ethanol) was examined in vitro and in vivo. Our analysis revealed that mechanochemical disruption caused a significant overproduction of reactive oxygen species (ROS) in multiple HCC cell lines (HepG2, PLC/PRF/5, and Hep3B). This led to a decrease in cell viability and long-term proliferation due to increased expression and activity of death receptors TNFR1 and Fas. The cells that survived mechanochemical disruption had a reduced expression of cancer stem cell markers (CD133, CD90, CD49f) and a diminished colony-forming ability. Mechanochemical disruption also impeded HCC migration and their adhesion to vascular endothelium, two critical processes in hematogenous metastasis. The HCC transformation to a non-tumorigenic phenotype post mechanochemical disruption was confirmed by a lack of tumor spheroid formation in vitro and complete tumor regression in vivo. These results show that mechanochemical disruption inhibits uncontrolled proliferation and reduces tumorigenicity and aggressiveness of HCC cells through ROS overproduction and associated activation of TNF- and Fas-mediated cell death signaling. Our study identifies a novel curative therapeutic approach that can prevent the development of aggressive HCC phenotypes.

Near Infrared-Activated Dye-Linked ZnO Nanoparticles Release Reactive Oxygen Species for Potential Use in Photodynamic Therapy

Novel dye-linked zinc oxide nanoparticles (NPs) hold potential as photosensitizers for biomedical applications due to their excellent thermal- and photo-stability. The particles produced reactive oxygen species (ROS) upon irradiation with 850 nm near infrared (NIR) light in a concentration- and time-dependent manner. Upon irradiation, ROS detected in vitro in human umbilical vein endothelial cells (HUVEC) and human carcinoma MCF7 cells positively correlated with particle concentration and interestingly, ROS detected in MCF7 was higher than in HUVEC. Preferential cytotoxicity was also exhibited by the NPs as cell killing was higher in MCF7 than in HUVEC. In the absence of irradiation, dye-linked ZnO particles minimally affected the viability of cell (HUVEC) at low concentrations (<30 μg/mL), but viability significantly decreased at higher particle concentrations, suggesting a need for particle surface modification with poly (ethylene glycol) (PEG) for improved biocompatibility. The presence of PEG on particles after dialysis was indicated by an increase in size, an increase in zeta potential towards neutral, and spectroscopy results. Cell viability was improved in the absence of irradiation when cells were exposed to PEG-coated, dye-linked ZnO particles compared to non-surface modified particles. The present study shows that there is potential for biological application of dye-linked ZnO particles in photodynamic therapy.

CD40 induces renal cell carcinoma-specific differential regulation of TRAF proteins, ASK1 activation and JNK/p38-mediated, ROS-dependent mitochondrial apoptosis

A unique feature of CD40 among the TNF receptor (TNFR) superfamily is its exquisitely contextual effects, as originally demonstrated in normal and malignant B-lymphocytes. We studied renal cell carcinoma (RCC) in comparison to normal (human renal proximal tubule) cells, as a model to better understand the role of CD40 in epithelial cells. CD40 ligation by membrane-presented CD40 ligand (mCD40L), but not soluble CD40 agonist, induced extensive apoptosis in RCC cells; by contrast, normal cells were totally refractory to mCD40L. These findings underline the importance of CD40 'signal-quality' on cell fate and explain the lack of pro-apoptotic effects in RCC cells previously, while confirming the tumour specificity of CD40 in epithelial cells. mCD40L differentially regulated TRAF expression, causing sustained TRAF2/TRAF3 induction in RCC cells, yet downregulation of TRAF2 and no TRAF3 induction in normal cells, observations strikingly reminiscent of TRAF modulation in B-lymphocytes. mCD40L triggered reactive oxygen species (ROS) production, critical in apoptosis, and NADPH oxidase (Nox)-subunit p40phox phosphorylation, with Nox blockade abrogating apoptosis thus implying Nox-dependent initial ROS release. mCD40L mediated downregulation of Thioredoxin-1 (Trx-1), ASK1 phosphorylation, and JNK and p38 activation. Although both JNK/p38 were essential in apoptosis, p38 activation was JNK-dependent, which is the first report of such temporally defined JNK-p38 interplay during an apoptotic programme. CD40-killing entrained Bak/Bax induction, controlled by JNK/p38, and caspase-9-dependent mitochondrial apoptosis, accompanied by pro-inflammatory cytokine secretion, the repertoire of which also depended on CD40 signal quality. Previous reports suggested that, despite the ability of soluble CD40 agonist to reduce RCC tumour size in vivo via immunocyte activation, RCC could be targeted more effectively by combining CD40-mediated immune activation with direct tumour CD40 signalling. Since mCD40L represents a potent tumour cell-specific killing signal, our work not only offers insights into CD40's biology in normal and malignant epithelial cells, but also provides an avenue for a 'double-hit' approach for inflammatory, tumour cell-specific CD40-based therapy.

PM2.5, Fine Particulate Matter: A Novel Player in the Epithelial-Mesenchymal Transition?

Epithelial-mesenchymal transition (EMT) refers to the conversion of epithelial cells to mesenchymal phenotype, which endows the epithelial cells with enhanced migration, invasion, and extracellular matrix production abilities. These characteristics link EMT with the pathogenesis of organ fibrosis and cancer progression. Recent studies have preliminarily established that fine particulate matter with an aerodynamic diameter of less than 2.5 μm (PM_2.5) is correlated with EMT initiation. In this pathological process, PM_2.5 particles, excessive reactive oxygen species (ROS) derived from PM_2.5, and certain components in PM_2.5, such as ions and polyaromatic hydrocarbons (PAHs), have been implicated as potential EMT mediators that are linked to the activation of transforming growth factor β (TGF-β)/SMADs, NF-κB, growth factor (GF)/extracellular signal-regulated protein kinase (ERK), GF/phosphatidylinositol 3-kinase (PI3K)/Akt, wingless/integrated (Wnt)/β-catenin, Notch, Hedgehog, high mobility group box B1 (HMGB1)-receptor for advanced glycation end-products (RAGE), and aryl hydrocarbon receptor (AHR) signaling cascades and to cytoskeleton rearrangement. These pathways directly and indirectly transduce pro-EMT signals that regulate EMT-related gene expression in epithelial cells, finally inducing the characteristic alterations in morphology and functions of epithelia. In addition, novel associations between autophagy, ATP citrate lyase (ACLY), and exosomes with PM_2.5-induced EMT have also been summarized. However, some debates and paradoxes remain to be consolidated. This review discusses the potential molecular mechanisms underlying PM_2.5-induced EMT, which might account for the latent role of PM_2.5 in cancer progression and fibrogenesis.

Obestatin attenuated methamphetamine-induced PC12 cells neurotoxicity via inhibiting autophagy and apoptosis

Methamphetamine (METH) is an illicit dopaminergic neurotoxin and is an extremely addictive psychostimulant drug that influences monoamine neurotransmitter system of the brain and is responsible for enhancing energy and satisfaction and feelings of alertness. Long-lasting exposure to METH causes psychosis and increases the risk of Parkinson's disease. Studies have revealed that obestatin (OB) is a novel endogenous ligand, which may have neuroprotective effects. Hence, we hypothesized that OB might appropriately limit METH-induced neurotoxicity via the control of apoptotis and autophagy. In the current study, PC12 cells were exposed to both METH (0.5, 1, 2, 3, 4, and 6 mmol/L) and pretreatment OB (1, 10, 100, and 200 nmol/L) in vitro for 24 h to determine appropriate dose, and then downstream pathways were measured to investigate apoptosis and autophagy. The results have shown that OB reduced the apoptotic response post-METH exposure in PC12 cells by developing cell viability and diminishing apoptotic rates. Furthermore, the study has exhibited OB decreased gene expression of Beclin-1 by real-time polymerase chain reaction and LC3-II by Western blotting in METH-induced PC12 cells, which demonstrated that autophagy is reduced. The study is proposed that OB is useful in reducing oxidative stress, which may also play an essential role in the regulation of METH-triggered apoptotic response. So these data indicate that OB could potentially alleviate METH-induced neurotoxicity via the reduction of apoptotic and autophagy responses.

Usnic acid induces apoptosis in human gastric cancer cells through ROS generation and DNA damage and causes up-regulation of DNA-PKcs and γ-H2A.X phosphorylation

Usnic acid, a dibenzofuran derivative found in many lichen species, is reported to have anticancer activity against human gastric cancer. We investigated the molecular alterations associated with anticancer effects of usnic acid against human gastric adenocarcinoma AGS and gastric carcinoma SNU-1 cells. Usnic acid (10-25 μM) treatment to these cells caused a significant increase in mitochondrial membrane depolarization and apoptotic cells. Apoptosis induction was accompanied by an increase in the ratio of Bax:Bcl-2 expression and cleaved-PARP. Usnic acid increased the comet tail length and tail DNA in alkaline comet assay indicating DNA double-strand breaks which was also evidenced by an increase in γH2A.X (Ser139) phosphorylation. The expression of DNA damage response proteins including DNA-PKcs, pATM (Ser1981), Chk-2 and p53 were increased. Further, N-acetyl cysteine, a known reactive oxygen species (ROS) scavenger, reversed the effects of usnic acid on expression of DNA damage response proteins and γH2A.X (Ser139) phosphorylation. This reversal was also observed in comet assay in a time and dose-dependent manner suggesting that usnic acid-induced DNA damage was caused by ROS. In addition, the non-toxic concentrations (1-10 μM) of usnic acid inhibited colony forming potential of AGS cells indicating its anti-proliferation activity. More importantly, the concentration of usnic acid that caused significant death in gastric cancer cells, did not show any considerable toxicity to normal human embryonic kidney HEK293 cells, human keratinocyte HaCaT cells and mouse primary gastric cells. Collectively, these results for the first time demonstrated the selective apoptotic effect of usnic acid (10-25 μM) through ROS generation and DNA damage on human gastric cancer cells accompanied with upregulation of γH2A.X (Ser139) phosphorylation, DNA-PKcs and p53.

The Polyphenols as Potential Agents in Prevention and Therapy of Prostate Diseases

In recent years, the progress of science and medicine greatly has influenced human life span and health. However, lifestyle habits, like physical activity, smoking cessation, moderate alcohol consumption, diet, and maintaining a normal body weight represent measures that greatly reduce the risk of various diseases. The type of diet is very important for disease development. Numerous epidemiological clinical data confirm that longevity is linked to predominantly plant-based diets and it is related to a long life; whereas the western diet, rich in red meat and fats, increases the risk of oxidative stress and thus the risk of developing various diseases and pre-aging. This review is focused on the bioavailability of polyphenols and the use of polyphenols for the prevention of prostate diseases. Special focus in this paper is placed on the isoflavonoids and flavan-3-ols, subgroups of polyphenols, and their protective effects against the development of prostate diseases.

The Combination of Astragalus membranaceus and Angelica sinensis Inhibits Lung Cancer and Cachexia through Its Immunomodulatory Function

Lung cancer and its related cachexia are the leading cause of cancer death in the world. In this study, we report the inhibitory effect of the combined therapy of Astragalus membranaceus and Angelica sinensis, on tumor growth and cachexia in tumor-bearing mice. Lewis lung carcinoma cells were inoculated into male C57BL/6 and CAnN.Cg-Foxn1^nu nude mice. After tumor inoculation, mice were fed orally by the combination of AM and AS in different doses. In C57BL/6 mice, the combination of AM and AS significantly inhibited the growth of cancer tumor and prevented the loss of body weight and skeletal muscle. It also diminished the formation of free radicals and cytokines, stimulated the differentiation of NK and Tc cells, and rebalanced the ratios of Th/Tc cells, Th1/Th2 cytokines, and M1/M2 tumor-associated macrophages. The herbal combination also downregulated the expression of NFκΒ, STAT3, HIF-1α, and VEGF in tumors. In contrast, the findings were not observed in the nude mice. Therefore, the combination of AM and AS is confirmed to inhibit the progression of lung cancer, cancer cachexia, and cancer inflammation through the immunomodulatory function.

Isolation of Phytochemicals from Bauhinia variegata L. Bark and Their In Vitro Antioxidant and Cytotoxic Potential

Plants have been the basis of traditional medicine since the dawn of civilizations. Different plant parts possess various phytochemicals, playing important roles in preventing and curing diseases. Scientists, through extensive experimental studies, are playing an important part in establishing the use of phytochemicals in medicine. However, there are still a large number of medicinal plants which need to be studied for their phytochemical profile. In this study, the objective was to isolate phytochemicals from bark of Bauhinia variegata L. and to study them for their antioxidant and cytotoxic activities. The bark was extracted with methanol, followed by column chromatography and thus isolating kaempferol, stigmasterol, protocatechuic acid-methyl ester (PCA-ME) and protocatechuic acid (PCA). 2,2-azinobis-3-ethyl-benzothiazoline-6-sulfonic acid (ABTS) and 2, 2'-diphenyl-1-picrylhydrazyl radical (DPPH) radical scavenging assays were utilized for assessment of antioxidant activity, and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) dye reduction assay was used to determine cytotoxic activity against C-6 glioma rat brain, MCF-7 breast cancer, and HCT-15 colon cancer cell lines. The compounds were found to have significant antioxidant and cytotoxic activity. Since there is a considerable increase in characterizing novel chemical compounds from plant parts, the present study might be helpful for chemotaxonomic determinations, for understanding of medicinal properties as well as for the quality assessment of herbal supplements containing B. variegata bark, thus establishing its use in traditional medicine.

Autophagy inhibition enhances Matrine derivative MASM induced apoptosis in cancer cells via a mechanism involving reactive oxygen species-mediated PI3K/Akt/mTOR and Erk/p38 signaling

Background

In the quest for new anti-cancer drugs, the drug discovery process has shifted to screening of active ingredients in traditional eastern medicine. Matrine is an active alkaloid isolated from plants of the Sophora genus used in traditional Chinese herbal medicine that exhibits a wide spectrum of biological properties and has a potential as an anti-proliferative agent. In this study, we investigated the anticancer property of MASM, ([(6aS, 10S, 11aR, 11bR, 11cS)210-Methylamino-dodecahydro-3a, 7a-diaza-benzo (de)anthracene-8-thione]), a potent derivative of matrine.

Methods

Four epithelial cancer cell lines representing the dominant cancers, namely: A549 (non-small-cell lung cancer cell line), MCF-7 and MDA-MB-231 (breast cancer cell lines), and Hela (cervical cancer cell line) were employed, and the mechanistic underpinning of MASM-induced apoptosis was investigated using flow cytometry, western blot and immunofluorescence.

Results

MASM, induced apoptosis via caspase 3 dependent and independent pathways, and autophagy in all the four cancer cell lines, but post-EMT (epithelial mesenchymal transition) cells showed greater sensitivity to MASM. Scavenging reactive oxygen species using N-acetylcysteine rescued all cancer cell lines from apoptosis and autophagy. Mechanistic analysis revealed that MASM induced autophagy involves inhibition of Akt signaling and the activation of Erk and p38 signaling, and inhibition of autophagy further enhanced the apoptosis induced by MASM.

Conclusions

These results indicate that MASM possesses potency against cancer cells and modulating autophagy during MASM administration could be used to further enhance its therapeutic effects.

Deferoxamine Enhanced Mitochondrial Iron Accumulation and Promoted Cell Migration in Triple-Negative MDA-MB-231 Breast Cancer Cells Via a ROS-Dependent Mechanism

In our previous study, Deferoxamine (DFO) increased the iron concentration by upregulating the expression levels of TfR1 and DMT1 and exacerbated the migration of triple-negative breast cancer cells. However, the mechanisms of iron distribution and utilization in triple-negative breast cancer cells with a DFO-induced iron deficiency are still unclear. In this study, triple-negative MDA-MB-231 and estrogen receptor (ER)-positive MCF-7 breast cancer cells were used to investigate the mechanisms of iron distribution and utilization with a DFO-induced iron deficiency. We found that the mitochondrial iron concentration was elevated in MDA-MB-231 cells, while it was decreased in MCF-7 cells after DFO treatment. The cellular and mitochondrial reactive oxygen species (ROS) levels increased in both breast cancer cell types under DFO-induced iron-deficient conditions. However, the increased ROS levels had different effects on the different breast cancer cell types: Cell viability was inhibited and apoptosis was enhanced in MCF-7 cells, but cell viability was maintained and cell migration was promoted in MDA-MB-231 cells through the ROS/NF-κB and ROS/TGF-β signaling pathways. Collectively, this study suggests that under DFO-induced iron-deficient conditions, the increased mitochondrial iron levels in triple-negative MDA-MB-231 breast cancer cells would generate large amounts of ROS to activate the NF-κB and TGF-β signaling pathways to promote cell migration.

Effect of irinotecan on the tongue mucosa of juvenile male albino rat at adulthood

Irinotecan is one of the most important anti-tumour drugs against a broad spectrum of malignancies, but is known to be associated with possible oral complications. The aim of the present study was to evaluate the effect of irinotecan on the tongue mucosa of juvenile male albino rat at adulthood using different histological and immunohistochemical methods. Twenty juvenile male albino rats were divided equally into two groups: control and irinotecan-treated group (single injection of 200 mg irinotecan/kg, then kept for four weeks without treatment). The tongue specimens were processed for light microscopy and scanning electron microscopy. The irinotecan-treated group showed statistically significant shortening and thinning of the lingual papillae. There was loss of the normal appearance of the filiform papillae with focal cell loss alternating with areas of hyperkeratosis. Focal separation of the keratin layer, some nuclear changes and vacuolation of some epithelial cells were detected. Dilated congested blood vessels and mild mononuclear cellular infiltration were encountered. Atrophic fungiform papillae with ill-defined taste bud cells were observed. A statistically significant decrease in the pattern of Ki67 immunohistochemical staining reaction was detected in comparision to the control group. Scanning electron microscopy revealed different signs of atrophy of the tongue papillae. Focal areas of desquamation of lingual papillae were observed revealing some filiform papillae with desquamated surface, bisected tips and evident thinning. Some extravasated red blood cells could be detected. Thus irinotecan caused significant morphological and morphometrical alterations of the tongue mucosa in particularly the filiform papillae.

Effect of cigarette smoke extract on mitochondrial heme-metabolism: An in vitro model of oral cancer progression

Tobacco smoking is considered as one of the major risk factors for development of oral cancer. In vitro studies indicate that cigarette smoke initiates transformation of epithelial cells toward development of oral cancer through altering mitochondrial metabolic pathways. However the present in vitro models need to be improved to correlate these molecular changes with epithelial transformations. In present study, we investigated the association of mitochondrial metabolic events with oral cancer progression under cigarette smoke extract (CSE). In this regard, an in vitro model of oral keratinocyte cell line (MOE1A) was developed by exposing them with different concentrations of CSE. Alterations in cellular phenomena were confirmed by Fourier-transform infrared spectroscopy (FTIR) study, which indicated changes in important functional groups of CSE-induced oral cells. Enhanced reactive oxygen species (ROS) of exposed cells altered the mitochondrial metabolic activities in terms of increased mitochondrial mass and DNA content. Further, mitochondrial heme-metabolism was investigated and real-time PCR study showed altered expression of important genes like ALAS1, ABCB6, CPOX, FECH, HO-1. Both transcriptomic and proteomic studies showed up- and down-regulation of important biomarkers related to cellular cancer progression. Overall data suggest that CSE alters mitochondrial heme metabolic pathway and initiates cancer progression through modifying cellar biomarkers in oral epithelial cells.

Ursolic and Oleanolic Acids Induce Mitophagy in A549 Human Lung Cancer Cells

Ursolic and oleanolic acids are natural isomeric triterpenes known for their anticancer activity. Here, we investigated the effect of triterpenes on the viability of A549 human lung cancer cells and the role of autophagy in their activity. The induction of autophagy, the mitochondrial changes and signaling pathway stimulated by triterpenes were systematically explored by confocal microscopy and western blotting. Ursolic and oleanolic acids induce autophagy in A549 cells. Ursolic acid activates AKT/mTOR pathways and oleanolic acid triggers a pathway independent on AKT. Both acids promote many mitochondrial changes, suggesting that mitochondria are targets of autophagy in a process known as mitophagy. The PINK1/Parkin axis is a pathway usually associated with mitophagy, however, the mitophagy induced by ursolic or oleanolic acid is just dependent on PINK1. Moreover, both acids induce an ROS production. The blockage of autophagy with wortmannin is responsible for a decrease of mitochondrial membrane potential (Δψ) and cell death. The wortmannin treatment causes an over-increase of p62 and Nrf2 proteins promote a detoxifying effect to rescue cells from the death conducted by ROS. In conclusion, the mitophagy and p62 protein play an important function as a survival mechanism in A549 cells and could be target to therapeutic control.

Warburg effect and its role in tumourigenesis

Glucose is a crucial molecule in energy production and produces different end products in non-tumourigenic- and tumourigenic tissue metabolism. Tumourigenic cells oxidise glucose by fermentation and generate lactate and adenosine triphosphate even in the presence of oxygen (Warburg effect). The Na⁺/H⁺-antiporter is upregulated in tumourigenic cells resulting in release of lactate- and H⁺ ions into the extracellular space. Accumulation of lactate- and proton ions in the extracellular space results in an acidic environment that promotes invasion and metastasis. Otto Warburg reported that tumourigenic cells have defective mitochondria that produce less energy. However, decades later it became evident that these mitochondria have adapted with alterations in mitochondrial content, structure, function and activity. Mitochondrial biogenesis and mitophagy regulate the formation of new mitochondria and degradation of defective mitochondria in order to combat accumulation of mutagenic mitochondrial deoxyribonucleic acid. Tumourigenic cells also produce increase reactive oxygen species (ROS) resulting from upregulated glycolysis leading to pathogenesis including cancer. Moderate ROS levels exert proliferative- and prosurvival signaling, while high ROS quantities induce cell death. Understanding the crosstalk between aberrant metabolism, redox regulation, mitochondrial adaptions and pH regulation provides scientific- and medical communities with new opportunities to explore cancer therapies.

Lead bioactive compounds of Aloe vera as potential anticancer agent

Aloe vera (Aloe barbadensis Miller) is a perennial succulent medicinal plant. It has been used as a traditional or folk medicine for thousands of years and claimed that it possesses wound and burn healing activities, and anti-inflammatory as well as immunomodulatory effects. In recent years, the use of Aloe vera has been growing as a dietary supplement. The pre-clinical studies over the last couple of decades uncover the potential therapeutic activities of Aloe vera and its bioactive compounds, especially against neoplastic disease. Such investigations indicate the possible preventive as well as therapeutic effects of Aloe vera against cancer. Here, we discuss the crucial bioactive compounds of Aloe vera that have been harnessed against cancer and also address several mechanisms of action of these lead bioactive compounds compared to other standard drugs involved in cancer prevention and treatment.

Deoxynivalenol induces oxidative stress, inflammatory response and apoptosis in bovine mammary epithelial cells

Deoxynivalenol (DON) is a toxic secondary metabolite produced by Fusarium graminearum. It is one of the most common feed contaminants that poses a serious threat to the health and performance of dairy cows. This study investigated the in vitro cytotoxicity of DON on bovine mammary epithelial cells (MAC-T). DON at different concentrations (0.25, 0.3, 0.5, 0.8, 1 or 2 μg/ml) inhibited the growth of MAC-T cells after 24 hr of exposure (p < .001). DON at 0.25 μg/ml increased lactate dehydrogenase (LDH) leakage (p < .05); decreased glutathione (GSH) levels (p < .001), total superoxide dismutase (T-SOD) activity and total antioxidant capacity (T-AOC; p < .01); and increased malondialdehyde (MDA) concentration (p < .01) in MAC-T cells after 24 hr of exposure. We also observed that DON increased reactive oxygen species (ROS) levels in cells incubated for 9, 15 and 24 hr (p < .001). DON at 0.25 μg/ml triggered oxidative damage in MAC-T cells. Furthermore, it induced an inflammatory response in the cells incubated for 9, 15 and 24 hr (p < .05) by increasing the mRNA expression levels of nuclear factor kappa B, myeloid differentiation factor 88 (MyD88), tumour necrosis factor-α (TNF-α), interleukin-1β (IL-1β), IL-6, cyclooxygenase-2 and IL-8. We further examined the effect of DON on apoptosis. DON prevented normal proliferation of MAC-T cells by blocked cell cycle progression in 24 hr (p < .001). In addition, the apoptosis rate measured using annexin V-FITC significantly increased (p < .05) with increase in the mRNA expression level of Bax (p < .01) and increase in the Bax/Bcl-2 ratio (p < .01) in cells incubated for 24 hr. In summary, DON exerts toxic effects in MAC-T cells by causing oxidative stress, inducing an inflammatory response, affecting cell cycle and leading to apoptosis.

Lambda-Carrageenan Enhances the Effects of Radiation Therapy in Cancer Treatment by Suppressing Cancer Cell Invasion and Metastasis through Racgap1 Inhibition

Radiotherapy is used extensively in cancer treatment, but radioresistance and the metastatic potential of cancer cells that survive radiation remain critical issues. There is a need for novel treatments to improve radiotherapy. Here, we evaluated the therapeutic benefit of λ-carrageenan (CGN) to enhance the efficacy of radiation treatment and investigated the underlying molecular mechanism. CGN treatment decreased viability in irradiated cancer cells and enhanced reactive oxygen species accumulation, apoptosis, and polyploid formation. Additionally, CGN suppressed radiation-induced chemoinvasion and invasive growth in 3D lrECM culture. We also screened target molecules using a gene expression microarray analysis and focused on Rac GTPase-activating protein 1 (RacGAP1). Protein expression of RacGAP1 was upregulated in several cancer cell lines after radiation, which was significantly suppressed by CGN treatment. Knockdown of RacGAP1 decreased cell viability and invasiveness after radiation. Overexpression of RacGAP1 partially rescued CGN cytotoxicity. In a mouse xenograft model, local irradiation followed by CGN treatment significantly decreased tumor growth and lung metastasis compared to either treatment alone. Taken together, these results suggest that CGN may enhance the effectiveness of radiation in cancer therapy by decreasing cancer cell viability and suppressing both radiation-induced invasive activity and distal metastasis through downregulating RacGAP1 expression.

Ambidextrous Approach To Disrupt Redox Balance in Tumor Cells with Increased ROS Production and Decreased GSH Synthesis for Cancer Therapy

An effective steady-state redox balance is maintained in cancer cells, allowing for protection against oxidative stress and thereby enhancing cell proliferation and tumor growth. Disruption of this redox balance would increase the cellular content of reactive oxygen species (ROS) and potentiate oxidative stress-induced cell death in tumor cells, thus representing an effective strategy for cancer treatment. Glutathione (GSH) is a major reducing agent, and its cellular levels are determined at least partly by the availability of cysteine via xCT (SLC7A11)-mediated entry of cystine into cells. We developed a nanoplatform using ZnO nanoparticles (NPs) as a carrier, loaded with salicylazosulfapyridine (SASP), and stabilized with DSPE-PEG, to form ultra-small NPs (SASP/ZnO NPs). The goal of this NP strategy is to disrupt the redox balance in cells by two mechanisms: increased generation of ROS and decreased synthesis of GSH. Such an approach would be effective in killing tumor cells. As expected, the SASP/ZnO NPs enhanced ROS production because of ZnO and impaired GSH synthesis because of SASP-induced inhibition of xCT (SLC7A11) transport function. As a consequence, treatment of tumor cells with SASP/ZnO NPs in vitro and in vivo resulted in a synergistic disruptive effect on redox balance in tumor cells and induced cell death and decreased tumor growth. This ambidextrous approach has potential in cancer therapy by combining two complementary pathways to disrupt the redox balance in tumor cells.

p53 sensitizes chemoresistant non-small cell lung cancer via elevation of reactive oxygen species and suppression of EGFR/PI3K/AKT signaling

Background

Non-small cell lung cancer (NSCLC) is the leading cause of cancer deaths primarily due to chemoresistance. Somatic mutation of TP53 (36%) and epidermal growth factor receptor (EGFR; > 30%) are major contributors to cisplatin (CDDP) resistance. Substantial evidence suggests the elevated levels of reactive oxygen species (ROS) is a key determinant in cancer. The elevated ROS can affect the cellular responses to chemotherapeutic treatments. Although the role of EGFR in PI3K/Akt signaling cascade in NSCLC is extensively studied, the molecular link between EGFR and p53 and the role of ROS in pathogenesis of NSCLC are limitedly addressed. In this study, we investigated the role of p53 in regulation of ROS production and EGFR signaling, and the chemosensitivity of NSCLC.

Methods

In multiple NSCLC cell lines with varied p53 and EGFR status, we compared and examined the protein contents involved in EGFR-Akt-P53 signaling loop (EGFR, P-EGFR, Akt, P-Akt, p53, P-p53) by Western blot. Apoptosis was determined based on nuclear morphological assessment using Hoechst 33258 staining. Cellular ROS levels were measured by dichlorofluorescin diacetate (DCFDA) staining followed by flow cytometry analysis.

Results

We have demonstrated for the first time that activation of p53 sensitizes chemoresistant NSCLC cells to CDDP by down-regulating EGFR signaling pathway and promoting intracellular ROS production. Likewise, blocking EGFR/PI3K/AKT signaling with PI3K inhibitor elicited a similar response. Our findings suggest that CDDP-induced apoptosis in chemosensitive NSCLC cells involves p53 activation, leading to suppressed EGFR signaling and ROS production. In contrast, in chemoresistant NSCLC, activated Akt promotes EGFR signaling by the positive feedback loop and suppresses CDDP-induced ROS production and apoptosis.

Conclusion

Collectively, our study reveals that the interaction of the p53 and Akt feedback loops determine the fate of NSCLC cells and their CDDP sensitivity.

Electronic supplementary material

The online version of this article (10.1186/s12935-019-0910-2) contains supplementary material, which is available to authorized users.

Intelligent gold nanostars for in vivo CT imaging and catalase-enhanced synergistic photodynamic & photothermal tumor therapy

Photodynamic therapy (PDT) is a clinically approved and minimally invasive form of cancer treatment. However, due to hypoxia at the tumor site and phototoxicity to normal tissues, monotherapies using photosensitizers remain suboptimal. This study aimed to develop a highly selective controlled catalase-enhanced synergistic photodynamic and photothermal cancer therapy based on gold nanostars.

Methods: Gold nanostars (GNS) with high thermal conversion efficiency were used as the core for photothermal therapy (PTT) and the shell consisted of the photosensitizer Ce6-loaded mesoporous silicon. The shell was modified with catalase (E), which catalyzes the conversion of hydrogen peroxide to oxygen at the tumor site, alleviating hypoxia and increasing the effect of the photodynamic treatment. Finally, a phospholipid derivative with c(RGDyK) was used as the targeting moiety and the nanoparticle-encapsulating material.

Results: The nanoprobe exhibited good dispersion, high stability, and high photothermal conversion efficiency (~28%) for PTT as well as a photodynamic "on-off" effect on Ce6 encapsulated in mesoporous channels. The "release" of Ce6 was only triggered under photothermal stimulation in vivo. Due to its targeting ability, 72 h after injection of the probe, the tumor site in mice showed an observable CT response. The combined treatment using photothermal therapy (PTT) and catalase-enhanced photo-controlled PDT exerted a superior effect to PTT or PDT monotherapies.

Conclusion: Our findings demonstrate that the use of this intelligent nanoprobe for CT-targeted image-guided treatment of tumors with integrated photothermal therapy (PTT) and catalase-enhanced controlled photodynamic therapy (PDT) may provide a novel approach for cancer theranostics.

ROS and the DNA damage response in cancer

Reactive oxygen species (ROS) are a group of short-lived, highly reactive, oxygen-containing molecules that can induce DNA damage and affect the DNA damage response (DDR). There is unequivocal pre-clinical and clinical evidence that ROS influence the genotoxic stress caused by chemotherapeutics agents and ionizing radiation. Recent studies have provided mechanistic insight into how ROS can also influence the cellular response to DNA damage caused by genotoxic therapy, especially in the context of Double Strand Breaks (DSBs). This has led to the clinical evaluation of agents modulating ROS in combination with genotoxic therapy for cancer, with mixed success so far. These studies point to context dependent outcomes with ROS modulator combinations with Chemotherapy and radiotherapy, indicating a need for additional pre-clinical research in the field. In this review, we discuss the current knowledge on the effect of ROS in the DNA damage response, and its clinical relevance.

Robust identification of molecular phenotypes using semi-supervised learning

BACKGROUND

Modern molecular profiling techniques are yielding vast amounts of data from patient samples that could be utilized with machine learning methods to provide important biological insights and improvements in patient outcomes. Unsupervised methods have been successfully used to identify molecularly-defined disease subtypes. However, these approaches do not take advantage of potential additional clinical outcome information. Supervised methods can be implemented when training classes are apparent (e.g., responders or non-responders to treatment). However, training classes can be difficult to define when assessing relative benefit of one therapy over another using gold standard clinical endpoints, since it is often not clear how much benefit each individual patient receives.

RESULTS

We introduce an iterative approach to binary classification tasks based on the simultaneous refinement of training class labels and classifiers towards self-consistency. As training labels are refined during the process, the method is well suited to cases where training class definitions are not obvious or noisy. Clinical data, including time-to-event endpoints, can be incorporated into the approach to enable the iterative refinement to identify molecular phenotypes associated with a particular clinical variable. Using synthetic data, we show how this approach can be used to increase the accuracy of identification of outcome-related phenotypes and their associated molecular attributes. Further, we demonstrate that the advantages of the method persist in real world genomic datasets, allowing the reliable identification of molecular phenotypes and estimation of their association with outcome that generalizes to validation datasets. We show that at convergence of the iterative refinement, there is a consistent incorporation of the molecular data into the classifier yielding the molecular phenotype and that this allows a robust identification of associated attributes and the underlying biological processes.

CONCLUSIONS

The consistent incorporation of the structure of the molecular data into the classifier helps to minimize overfitting and facilitates not only good generalization of classification and molecular phenotypes, but also reliable identification of biologically relevant features and elucidation of underlying biological processes.

Yttrium oxide nanoparticle loaded scaffolds with enhanced cell adhesion and vascularization for tissue engineering applications

In situ tissue engineering is emerging as a novel approach in tissue engineering to repair damaged tissues by boosting the natural ability of the body to heal itself. This can be achieved by providing suitable signals and scaffolds that can augment cell migration, cell adhesion on the scaffolds and proliferation of endogenous cells that facilitate the repair. Lack of appropriate cell proliferation and angiogenesis are among the major issues associated with the limited success of in situ tissue engineering during in vivo studies. Exploitation of metal oxide nanoparticles such as yttrium oxide (Y₂O₃) nanoparticles may open new horizons in in situ tissue engineering by providing cues that facilitate cell proliferation and angiogenesis in the scaffolds. In this context, Y₂O₃ nanoparticles were synthesized and incorporated in polycaprolactone (PCL) scaffolds to enhance the cell proliferation and angiogenic properties. An optimum amount of Y₂O₃-containing scaffolds (1% w/w) promoted the proliferation of fibroblasts (L-929) and osteoblast-like cells (UMR-106). Results of chorioallantoic membrane (CAM) assay and the subcutaneous implantation studies in rats demonstrated the angiogenic potential of the scaffolds loaded with Y₂O₃ nanoparticles. Gene expression study demonstrated that the presence of Y₂O₃ in the scaffolds can upregulate the expression of cell proliferation and angiogenesis related biomolecules such as VEGF and EGFR. Obtained results demonstrated that Y₂O₃ nanoparticles can perform a vital role in tissue engineering scaffolds to promote cell proliferation and angiogenesis.