Artocarpin, an isoprenyl flavonoid, induces p53-dependent or independent apoptosis via ROS-mediated MAPKs and Akt activation in non-small cell lung cancer cells

Personalizing Therapy Outcomes through Mitogen-Activated Protein Kinase Pathway Inhibition in Non-Small Cell Lung Cancer

Lung cancer (LC) is a highly invasive malignancy and the leading cause of cancer-related deaths, with non-small cell lung cancer (NSCLC) as its most prevalent histological subtype. Despite all breakthroughs achieved in drug development, the prognosis of NSCLC remains poor. The mitogen-activated protein kinase signaling cascade (MAPKC) is a complex network of interacting molecules that can drive oncogenesis, cancer progression, and drug resistance when dysregulated. Over the past decades, MAPKC components have been used to design MAPKC inhibitors (MAPKCIs), which have shown varying efficacy in treating NSCLC. Thus, recent studies support the potential clinical use of MAPKCIs, especially in combination with other therapeutic approaches. This article provides an overview of the MAPKC and its inhibitors in the clinical management of NSCLC. It addresses the gaps in the current literature on different combinations of selective inhibitors while suggesting two particular therapy approaches to be researched in NSCLC: parallel and aggregate targeting of the MAPKC. This work also provides suggestions that could serve as a potential guideline to aid future research in MAPKCIs to optimize clinical outcomes in NSCLC.

ONC212 enhances YM155 cytotoxicity by triggering SLC35F2 expression and NOXA-dependent MCL1 degradation in acute myeloid leukemia cells

Although the anticancer activity of ONC212 has been reported, the precise mechanism underlying its apoptotic effects remains unclear. In this study, we investigated the apoptotic mechanism of ONC212 in acute myeloid leukemia (AML) cells. ONC212 induces apoptosis, MCL1 downregulation, and mitochondrial depolarization in AML U937 cells. Ectopic MCL1 expression alleviates mitochondria-mediated apoptosis in ONC212-treated U937 cells. ONC212 triggers AKT phosphorylation, inducing NOX4-dependent ROS production and promoting HuR transcription. HuR-mediated ATF4 mRNA stabilization stimulates NOXA and SLC35F2 expression; ONC212-induced upregulation of NOXA leads to MCL1 degradation. The synergistic effect of ONC212 on YM155 cytotoxicity was dependent on increased SLC35F2 expression. In addition, YM155 feedback facilitated the activation of the ONC212-induced signaling pathway. A similar mechanism explains ONC212- and ONC212/YM155-induced AML HL-60 cell death. The continuous treatment of U937 cells with the benzene metabolite hydroquinone (HQ) generated U937/HQ cells, exhibiting enhanced responsiveness to the cytotoxic effects of ONC212. In U937/HQ cells, ONC212 triggered apoptosis through NOXA-mediated MCL1 downregulation, enhancing YM155 cytotoxicity. Collectively, our data suggested that ONC212 upregulated SLC35F2 expression and triggered NOXA-mediated MCL1 degradation in U937, U937/HQ, and HL-60 cells by activating the AKT/NOX4/HuR/ATF4 pathway. The ONC212-induced signaling pathway showed anti-AML activity and enhanced YM155 cytotoxicity.

A review of natural products and small-molecule therapeutics acting on central nervous system malignancies: Approaches for drug development, targeting pathways, clinical trials, and challenges

In 2021, the World Health Organization released the fifth edition of the central nervous system (CNS) tumor classification. This classification uses histopathology and molecular pathogenesis to group tumors into more biologically and molecularly defined entities. The prognosis of brain cancer, particularly malignant tumors, has remained poor worldwide, approximately 308,102 new cases of brain and other CNS tumors were diagnosed in the year 2020, with an estimated 251,329 deaths. The cost and time-consuming nature of studies to find new anticancer agents makes it necessary to have well-designed studies. In the present study, the pathways that can be targeted for drug development are discussed in detail. Some of the important cellular origins, signaling, and pathways involved in the efficacy of bioactive molecules against CNS tumorigenesis or progression, as well as prognosis and common approaches for treatment of different types of brain tumors, are reviewed. Moreover, different study tools, including cell lines, in vitro, in vivo, and clinical trial challenges, are discussed. In addition, in this article, natural products as one of the most important sources for finding new chemotherapeutics were reviewed and over 700 reported molecules with efficacy against CNS cancer cells are gathered and classified according to their structure. Based on the clinical trials that have been registered, very few of these natural or semi-synthetic derivatives have been studied in humans. The review can help researchers understand the involved mechanisms and design new goal-oriented studies for drug development against CNS malignancies.

Antioxidants activities of phytochemicals perspective modulation of autophagy and apoptosis to treating cancer

The study of chemicals extracted from natural sources should be encouraged due to the significant number of cancer deaths each year and the financial burden imposed by this disease on society. The causes of almost all cancers involve a combination of lifestyle, environmental factors, and genetic and inherited factors. Modern medicine researchers are increasingly interested in traditional phytochemicals as they hold potential for new bioactive compounds with medical applications. Recent publications have provided evidence of the antitumor properties of phytochemicals, a key component of traditional Chinese medicine, thereby opening new avenues for their use in modern medicine. Various studies have demonstrated a strong correlation between apoptosis and autophagy, two critical mechanisms involved in cancer formation and regulation, indicating diverse forms of crosstalk between them. Phytochemicals have the ability to activate both pro-apoptotic and pro-autophagic pathways. Therefore, understanding how phytochemicals influence the relationship between apoptosis and autophagy is crucial for developing a new cancer treatment strategy that targets these molecular mechanisms. This review aims to explore natural phytochemicals that have demonstrated anticancer effects, focusing on their role in regulating the crosstalk between apoptosis and autophagy, which contributes to uncontrolled tumor cell growth. Additionally, the review highlights the limitations and challenges of current research methodologies while suggesting potential avenues for future research in this field.

Tetrahydrobiopterin from cyanide-degrading bacterium Bacillus pumilus strain SVD06 induces apoptosis in human lung adenocarcinoma cell (A549)

Tetrahydrobiopterin (BH4) is an essential biological cofactor and a derivative of pterin which is considered potent anticancer agents. In continuation of our previous study on the identification of BH4 from cyanide-degrading Bacillus pumilus, the present study focuses on evaluating the anticancer properties of BH4 on A549, a human lung adenocarcinoma. Anticancer activity analysis shows that BH4 inhibited A549 cell growth after 24 h of incubation with 0.02 mg/mL. In acridine orange/ethidium bromide staining, BH4-treated A549 cells showed apoptotic morphology. BH4 treatment caused cell cycle arrest at G0/G1 phase compared to control cells. BH4 augmented p53 expression in alveolar cancer cells by downregulating MDM2 levels. There was downregulation of casp-3 and upregulation of iNOS gene in BH4-treated A549 cells. Further, docking studies indicated that BH4 had significant interactions with the above proteins affirming the apoptosis mechanism. Thus, BH4 could be considered a potential anticancer drug.

Himalayan flora: targeting various molecular pathways in lung cancer

The fatal amplification of lung cancer across the globe and the limitations of current treatment strategies emphasize the necessity for substitute therapeutics. The incorporation of phyto-derived components in chemo treatment holds promise in addressing those challenges. Despite the significant progressions in lung cancer therapeutics, the complexities of molecular mechanism and pathways underlying this disease remain inadequately understood, necessitating novel biomarker targeting. The Himalayas, abundant in diverse plant varieties with established chemotherapeutic potential, presents a promising avenue for investigating potential cures for lung carcinoma. The vast diversity of phytocompounds herein can be explored for targeting the disease. This review delves into the multifaceted targets of lung cancer and explores the established phytochemicals with their specific molecular targets. It emphasizes comprehending the intricate pathways that govern effective therapeutic interventions for lung cancer. Through this exploration of Himalayan flora, this review seeks to illuminate potential breakthroughs in lung cancer management using natural compounds. The amalgamation of Himalayan plant-derived compounds with cautiously designed combined therapeutic approaches such as nanocarrier-mediated drug delivery and synergistic therapy offers an opportunity to redefine the boundaries of lung cancer treatment by reducing the drug resistance and side effects and enabling an effective targeted delivery of drugs. Furthermore, additional studies are obligatory to understand the possible derivation of natural compounds used in current lung cancer treatment from plant species within the Himalayan region.

β-Elemene enhances erlotinib sensitivity through induction of ferroptosis by upregulating lncRNA H19 in EGFR-mutant non-small cell lung cancer

Nearly half of all Asian non-small cell lung cancer (NSCLC) patients harbour epidermal growth factor receptor (EGFR) mutations, and first-generation EGFR tyrosine kinase inhibitors (TKIs) are one of the first-line treatments that have improved the outcomes of these patients. Unfortunately, 20% of these patients can not benefit from the treatment. The basis of this primary resistance is poorly understood. Therefore, overcoming EGFR-TKI primary resistance and maintaining the efficacy of TKIs has become a key issue. β-Elemene, a sesquiterpene compound extracted from Curcuma aromatica Salisb. (wenyujing), has shown potent antitumor effects. In this research, we found that β-elemene combined with erlotinib enhanced the cytotoxicity of erlotinib to primary EGFR-TKI-resistant NSCLC cells with EGFR mutations and that ferroptosis was involved in the antitumor effect of the combination treatment. We found that lncRNA H19 was significantly downregulated in primary EGFR-TKI-resistant NSCLC cell lines and was upregulated by the combination treatment. Overexpression or knockdown of H19 conferred sensitivity or resistance to erlotinib, respectively, in both in vitro and in vivo studies. The high level of H19 enhanced the cytotoxicity of erlotinib by inducing ferroptosis. In conclusion, our data showed that β-elemene combined with erlotinib could enhance sensitivity to EGFR-TKIs through induction of ferroptosis via H19 in primary EGFR-TKI-resistant lung cancer, providing a promising strategy to overcome EGFR-TKI resistance in NSCLC patients.

Mitochondriotropic Derivative of Ethyl Ferulate, a Dietary Phenylpropanoid, Exhibits Enhanced Cytotoxicity in Cancer Cells via Mitochondrial Superoxide-Mediated Activation of JNK and AKT Signalling

Specific targeting of anti-cancer drugs to mitochondria is an emerging strategy to enhance cancer cell killing whilst simultaneously overcoming the problem of drug resistance, low bioavailability and limited clinical success of natural products. We have synthesized a mitochondria targeted derivative of Ethyl Ferulate (EF, a naturally occurring ester of ferulic acid), by conjugating it with triphenylphosphonium ion and compared its cytotoxicity with the parent molecule. Mito-Ethyl Ferulate (M-EF) was found to be more potent than EF (~ 400-fold) in inhibiting the growth of A549 and MCF-7 cells and suppressing the clonogenic potential of A549 cells. Notably, M-EF did not induce any cytotoxicity in normal cells (mouse normal fibroblast cells) up to a concentration of 25 μM. Furthermore, M-EF treatment induced significantly higher cell death in MCF-7 and A549 cells, as compared to EF via induction of apoptosis. M-EF treatment increased mitochondrial superoxide production and induced mitochondrial DNA damage and phosphorylation of JNK and AKT in A549 cells. Furthermore, M-EF induced increase in mitochondrial superoxide production and cytotoxicity was attenuated on pre-treatment with mitochondria-targeted antioxidant (mitoTEMPO) indicating the involvement of mitochondrial ROS in the cytotoxic effects of M-EF. Finally, in silico prediction revealed putative mitochondrial targets of M-EF which are known to regulate mitochondrial ROS and cell viability. In conclusion, the improved cytotoxic efficacy of M-EF exemplifies the use of mitochondria-specific drug delivery in future development of natural product based mitochondrial pharmacology.

Bioactive PI3-kinase/Akt/mTOR Inhibitors in Targeted Lung Cancer Therapy

One of the central signaling pathways with a regulatory effect on cell proliferation and survival is Akt/mTOR. In many human cancer types, for instance, lung cancer, the overexpression of Akt/mTOR has been reported. For this reason, either targeting cancer cells by synthetic or natural products affecting the Akt/mTOR pathway down-regulation is a useful strategy in cancer therapy. Direct inhibition of the signaling pathway or modulation of each related molecule could have significant feedback on the growth and proliferation of cancer cells. A variety of secondary metabolites has been identified to directly inhibit the AKT/mTOR signaling, which is important in the field of drug discovery. Naturally occurring nitrogenous and phenolic compounds can emerge as two pivotal classes of natural products possessing anticancer abilities. Herein, we have summarized the alkaloids and flavonoids for lung cancer treatment together with all the possible mechanisms of action relying on the Akt/mTOR pathway down-regulation. This review suggested that in search of new drugs, phytochemicals could be considered as promising scaffolds to be developed into efficient drugs for the treatment of cancer. In this review, the terms "Akt/mTOR", "Alkaloid", "flavonoid", and "lung cancer" were searched without any limitation in search criteria in Scopus, PubMed, Web of Science, and Google scholar engines.

Antioxidant, Anti-Inflammation and Antiaging Activities of Artocarpus altilis Methanolic Extract on Urban Particulate Matter-Induced HaCaT Keratinocytes Damage

Particulate matter (PM) is one of the reasons that exacerbate skin diseases. Impaired barrier function is a common symptom in skin diseases, including atopic dermatitis, eczema and psoriasis. Herbal extracts rich in antioxidants are thought to provide excellent pharmacological activities; however, the anti-pollution activity of Artocarpus altilis extract (AAM) has not been investigated yet. The present study demonstrated that 5 μg/mL of AAM was considered to be a safe dose for further experiments without cytotoxicity. Next, we evaluated the anti-pollution activity of AAM through the PM-induced keratinocytes damage cell model. The results showed that AAM could reduce PM-induced overproduction of intracellular ROS and the final product of lipid peroxidation, 4-hydroxynonenal (4HNE). In addition, AAM not only reduced the inflammatory protein expressions, including tumor necrosis factor α (TNFα), TNF receptor 1 (TNFR1) and cyclooxygenase-2 (COX-2), but also balanced the aging protein ratio of matrix metalloproteinase (MMPs) and tissue inhibitors of metalloproteases (TIMPs) through downregulating the phosphorylation of mitogen-activated protein kinase (MAPK) signaling. For skin barrier protection, AAM could repair PM-induced barrier function proteins damage, including filaggrin, loricrin and aquaporin 3 for providing anti-aging bioactivity. In conclusion, AAM has the potential to be developed as an anti-pollution active ingredient for topical skin products to prevent skin oxidation, inflammation and aging, and restore the skin barrier function.

A Literature Review of Artocarpus lacucha Focusing on the Phytochemical Constituents and Pharmacological Properties of the Plant

Studies have shown that approximately two-thirds of the plant species in the world have some medicinal value. Artocarpus lakoocha is a synonym for Artocarpus lacucha and is a plant that can be found in Indonesia. This medicinal plant has been used to treat many diseases. (1) Objective: This article discusses the scientific investigations carried out on A. lacucha, namely the plant’s chemical content, pharmacological activity, and active compounds. (2) Methods: The design of this study was based on an article that was a review of previous research. A search for relevant publications over the past ten years (2012–2022) using data from Pubmed, Proquest, Ebsco, ScienceDirect, and Google Scholar resulted in the discovery of 369 articles. (3) Results: Fifty relevant articles investigate A. lacucha’s substances and their applications in the health field. The presence of secondary metabolites and bioactive compounds has been reported, which is evidence that A. lacucha possesses antidiarrheal, immunostimulant, anticholesterol, and hepatoprotective agents. (4) Conclusions: Mobe (A. lacucha) is a plant native to North Sumatra, Indonesia. This plant is efficacious as an antioxidant, antibacterial, antidiarrheal, anti-inflammatory, analgesic, antinociceptive, schistosomicidal, hepatoprotective, neuroprotective, cytotoxic, antiglycation, and anticholesterol, and can also be used for anti-aging and wound healing. In addition to its various benefits, it turns out that this plant also has many active compounds that are useful to the health sector, especially the pharmaceutical field.

ERK: A Double-Edged Sword in Cancer. ERK-Dependent Apoptosis as a Potential Therapeutic Strategy for Cancer

The RAF/MEK/ERK signaling pathway regulates diverse cellular processes as exemplified by cell proliferation, differentiation, motility, and survival. Activation of ERK1/2 generally promotes cell proliferation, and its deregulated activity is a hallmark of many cancers. Therefore, components and regulators of the ERK pathway are considered potential therapeutic targets for cancer, and inhibitors of this pathway, including some MEK and BRAF inhibitors, are already being used in the clinic. Notably, ERK1/2 kinases also have pro-apoptotic functions under certain conditions and enhanced ERK1/2 signaling can cause tumor cell death. Although the repertoire of the compounds which mediate ERK activation and apoptosis is expanding, and various anti-cancer compounds induce ERK activation while exerting their anti-proliferative effects, the mechanisms underlying ERK1/2-mediated cell death are still vague. Recent studies highlight the importance of dual-specificity phosphatases (DUSPs) in determining the pro- versus anti-apoptotic function of ERK in cancer. In this review, we will summarize the recent major findings in understanding the role of ERK in apoptosis, focusing on the major compounds mediating ERK-dependent apoptosis. Studies that further define the molecular targets of these compounds relevant to cell death will be essential to harnessing these compounds for developing effective cancer treatments.

The T/Tn-Specific Helix pomatia Lectin Induces Cell Death in Lymphoma Cells Negative for T/Tn Antigens

Simple Summary

Changes in glycosylation, such as incomplete synthesis and higher density of O-glycans on the cell surface, are frequently observed in cancer cells. Several types of truncated O-glycan structures, e.g., T/Tn antigens, are suspected to disrupt molecular interactions between tumor microenvironment and immune cells, for instance, facilitating cancer immune-escape. Therefore, numerous exogenous lectins targeting aberrant O-glycans are interesting tools for cancer diagnosis, prognosis, and therapy. However, the ability of exolectins to detect subtle alterations in the glycome of tumor cells and to interfere in tumor/healthy cell interactions remains largely unknown. The present article reports for the first time that the Helix pomatia (HPA) lectin, a well-known T/Tn-specific lectin, currently used as a tool in cancer diagnostics, kills Tn-positive leukemia cells and Tn-negative lymphoma cells but does not affect healthy lymphocytes. Thus, HPA could be used to discriminate between tumor and healthy cells, and detect subtle alterations in the glycosylation profile.

Abstract

Morniga G is a T/Tn-specific lectin, inducing cell death in Tn-positive leukemias but not in healthy lymphocytes. Helix pomatia lectin (HPA) is another T/Tn-specific lectin, currently used as tool for cancer diagnostics. The HPA-mediated tumor cell death was evaluated on human leukemia and mouse lymphoma cells, and compared to the effect of Morniga G. Both lectins induced an equivalent percentage of cell death in Tn-positive Jurkat human leukemia. In contrast, EL4 mouse lymphoma resisted Morniga G-mediated cytotoxicity but were killed by HPA at concentrations of 2.5 μg/mL (0.032 nM) and higher. In both malignant cells, HPA-mediated cell death showed features compatible with apoptosis (annexin-externalization, caspase-activation, mitochondrial membrane depolarization, and ROS production). Cytometry analysis indicated that EL4 cells are T/Tn-negative. Because previous results showed a high amount of N-acetylgalactosamine (GalNAc, sugar present in Tn antigen) on EL4 cell surface, this GalNAc could be involved in the formation of truncated O-glycans other than the T/Tn residues. When compared to Morniga G, bioinformatic analysis suggested that HPA benefits from an extended carbohydrate-binding site, better adapted than Morniga G to the accommodation of more complex branched and truncated O-glycans (such as core 2). Finally, HPA killed EL4 cells but not healthy lymphocytes in a mixture of lymphoma cells + lymphocytes, suggesting that HPA selectively triggers tumor cell death.

Deficiency of voltage-gated proton channel Hv1 aggravates ovalbumin-induced allergic lung asthma in mice

Asthma is a chronic airway inflammation that caused by many factors. The voltage-gated proton channel Hv1 has been proposed to extrude excessive protons produced by NADPH oxidase (NOX) from cytosol to maintain its activity during respiratory bursts. Here, we showed that loss of Hv1 aggravates ovalbumin (OVA)-induced allergic lung asthma in mice. The numbers of total cells, eosinophils and neutrophils in bronchoalveolar lavage fluid (BALF) of Hv1-deficiency (KO) mice are obviously increased after OVA challenge compared with that of wild-type (WT) mice. Histopathological staining reveals that Hv1-deficiency aggravates OVA-induced inflammatory cell infiltration and goblet cell hyperplasia in lung tissues. The expression of IL-4, IL-5 and IL-13 are markedly increased in lung tissues of OVA-challenged KO mice compared with that of WT mice. Furthermore, the expression levels of NOX2, NOX4 and DUOX1 are dramatically increased, while the expression levels of SOD2 and catalase are significantly reduced in lung tissues of OVA-challenged KO mice compared with that of WT mice. The production of ROS in lung tissues of KO mice is significantly higher than that of WT mice after OVA challenge. Our data suggest that Hv1-deficiency might aggravate the development of allergic asthma through increasing ROS production.

Chemical Characterization, Antioxidant and Cytotoxic Activities of the Edible Fruits of Brosimun gaudichaudii Trécul, a Native Plant of the Cerrado Biome

In Brazil, there is a large diversity of species of small edible fruits that are considered sources of nutrients and functional properties. They present a high innovation domain for the pharmaceutical, cosmetic and food industries due to their health-promoting properties. Edible fruits from Brosimum gaudichaudii (Moraceae) are widely consumed and used in folk medicine and in feed by the population of the Brazilian Cerrado. Nevertheless, detailed information on the chemical fingerprint, antiradical activity and safety aspects of these fruits is still unknown. Thus, the aim of this work was to investigate the bioactive compounds of hydroethanolic extracts of fruits from Brosimum gaudichaudii using high-performance liquid chromatography combined with mass spectrometry using electrospray ionization (HPLC ESI-MS). Eighteen different compounds, including flavonoids, coumarins, arylbenzofurans, terpenoids, stilbenes, xanthones and esters, were detected. Moreover, the study indicated that the hydroethanolic extract of fruits from B. gaudichaudii presented low scavenging activity against 2,2-diphenyl-1-picrylhydrazyl radicals (IC₅₀ >800 μg mL^-1 ) and was cytotoxic (IC₅₀ <30 μg mL^-1 ) in Chinese hamster ovary cells (CHO-K1) by an in vitro assay. This is the first report of the chemical profile, antioxidant activity and cytotoxic properties of the hydroethanolic extract of fruits from B. gaudichaudii.

Kirenol Inhibits B[a]P-Induced Oxidative Stress and Apoptosis in Endothelial Cells via Modulation of the Nrf2 Signaling Pathway

Atherosclerosis is a persistent inflammatory disorder specified by the dysfunction of the arteries, the world's leading cause of cardiovascular diseases. We sought to determine the effectiveness of KRL in B[a]P-induced oxidative stress and programmed cell death in endothelial cells. Western blotting, real-time PCR, DCFH2-DA, and TUNEL staining were performed to detect pPI3K, pAKT, Nrf2, HO-1, NQO-1, Bcl2, Bax, and caspase-3 on the HUVECs. Through the pretreatment of KRL, a drastic enhancement was observed in the cell viability of HUVECs, whereas DNA damage and generation of reactive oxygen species induced by B[a]P was suppressed. KRL's potential use as an antioxidant was observed to have a direct correlation with an antioxidant gene's augmented expression and the nuclear translocation activation of Nrf2, even during the event when B[a]P was found to be absent. In addition, this study proved that the signaling cascades of PI3K/AKT mediated Nrf2 translocation. Activation of suppressed nuclear Nrf2 and reduced antioxidant genes across cells interacting with an LY294002 confirmed this phenomenon. In addition, knockdown of Nrf2 by Nrf2-siRNA transfection abolished the protective effects of KRL on HUVECs cells against oxidative damage. Finally, the expression of apoptotic proteins also supported the hypothesis that KRL may inhibit endothelial dysfunction. This study showed that KRL potentially prevents B[a]P-induced redox imbalance in the vascular endothelium by inducing the Nrf2 signaling via the PI3K/AKT pathway.

Potential chemopreventive, anticancer and anti-inflammatory properties of a refined artocarpin-rich wood extract of Artocarpus heterophyllus Lam

Colorectal cancer (CRC) represents the third leading cause of death among cancer patients below the age of 50, necessitating improved treatment and prevention initiatives. A crude methanol extract from the wood pulp of Artocarpus heterophyllus was found to be the most bioactive among multiple others, and an enriched extract containing 84% (w/v) artocarpin (determined by HPLC–MS–DAD) was prepared. The enriched extract irreversibly inhibited the activity of human cytochrome P450 CYP2C9, an enzyme previously shown to be overexpressed in CRC models. In vitro evaluations on heterologously expressed microsomes, revealed irreversible inhibitory kinetics with an IC₅₀ value of 0.46 µg/mL. Time- and concentration-dependent cytotoxicity was observed on human cancerous HCT116 cells with an IC₅₀ value of 4.23 mg/L in 72 h. We then employed the azoxymethane (AOM)/dextran sodium sulfate (DSS) colitis-induced model in C57BL/6 mice, which revealed that the enriched extract suppressed tumor multiplicity, reduced the protein expression of proliferating cell nuclear antigen, and attenuated the gene expression of proinflammatory cytokines (Il-6 and Ifn-γ) and protumorigenic markers (Pcna, Axin2, Vegf, and Myc). The extract significantly (p = 0.03) attenuated (threefold) the gene expression of murine Cyp2c37, an enzyme homologous to the human CYP2C9 enzyme. These promising chemopreventive, cytotoxic, anticancer and anti-inflammatory responses, combined with an absence of toxicity, validate further evaluation of A. heterophyllus extract as a therapeutic agent.

Zearalenone Induces Endothelial Cell Apoptosis through Activation of a Cytosolic Ca2+/ERK1/2/p53/Caspase 3 Signaling Pathway

Zearalenone (ZEN) is a mycotoxin that has been reported to damage various types of cells/tissues, yet its effects on endothelial cells (ECs) have never been investigated. Therefore, this study investigates the potential effects of ZEN using bovine aortic ECs (BAECs). In this study, we found that ZEN induced apoptosis of BAECs through increased cleavage of caspase 3 and poly ADP-ribose polymerase (PARP). ZEN also increased phosphorylation of ERK1/2 and p53, and treatment with the ERK1/2 or p53 inhibitor reversed ZEN-induced EC apoptosis. Transfection of BAECs with small interfering RNA against ERK1/2 or p53 revealed ERK1/2 as an upstream target of p53 in ZEN-stimulated apoptosis. ZEN increased the production of reactive oxygen species (ROS), yet treatment with the antioxidant did not prevent EC apoptosis. Similarly, blocking of estrogen receptors by specific inhibitors also did not prevent ZEN-induced apoptosis. Finally, chelation of cytosolic calcium (Ca²⁺) using BAPTA-AM or inhibition of endoplasmic reticulum (ER) Ca²⁺ channel using 2-APB reversed ZEN-induced EC apoptosis, but not by inhibiting ER stress using 4-PBA. Together, our findings demonstrate that ZEN induces EC apoptosis through an ERK1/2/p53/caspase 3 signaling pathway activated by Ca²⁺ release from the ER, and this pathway is independent of ROS production and estrogen receptor activation.

PM2.5 facilitates IL-6 production in human osteoarthritis synovial fibroblasts via ASK1 activation

Osteoarthritis (OA) is a progressive degenerative joint disorder characterized by synovial inflammation. Interleukin-6 (IL-6) is a key proinflammatory cytokine in OA progression. Particulate matter 2.5 (PM2.5) exposure increases the risk of different diseases, including OA. Up until now, no studies have described any association between PM2.5 and IL-6 expression in human OA synovial fibroblasts (OASFs). Here, our data show that PM2.5 concentration- and time-dependently promoted IL-6 synthesis in human OASFs. We also found that reactive oxygen species (ROS) generation potentiated the effects of PM2.5 on IL-6 production. ASK1, ERK, p38, and JNK inhibitors reduced PM2.5-induced increases of IL-6 expression. Treatment of OASFs with PM2.5 promoted phosphorylation of these signaling cascades. We also found that PM2.5 enhanced c-Jun phosphorylation and its translocation into the nucleus. Thus, PM2.5 increases IL-6 production in human OASFs via the ROS, ASK1, ERK, p38, JNK, and AP-1 signaling pathways. Our evidence links PM2.5 with OA progression.

Encapsulation by Electrospraying of Anticancer Compounds from Jackfruit Extract (Artocarpus heterophyllus Lam): Identification, Characterization and Antiproliferative Properties

BACKGROUND

Compounds with biological activities had been reported in the jackfruit. These compounds are susceptible to structural changes such as isomerization and/or loss of bonds due to environmental factors. Then, the encapsulation for protecting is a necessary process.

OBJECTIVE

In this study, encapsulation of High-Value Biological Compounds (HVBC) was performed using High Degree of Polymerization Agave Fructans (HDPAF) and Whey Protein (WP) as encapsulating materials to preserve the biological properties of the HVBC.

METHODS

The extract was characterized by HPLC-MS in order to show the presence of compounds with preventive or therapeutic effects on chronic degenerative diseases such as cancer. The micrographs by Scanning Electron Microscopy (SEM), Thermal Analysis (TGA and DSC), photostabilization and antiproliferation of M12.C3.F6 cell line of capsules were evaluated.

RESULTS

The micrographs of the nanocapsules obtained by Scanning Electron Microscopy (SEM) showed spherical capsules with sizes between 700 and 800nm. No cracks, dents or deformations were observed. The Thermogravimetric Analysis (TGA) evidenced the decomposition of the unencapsulated extract ranging from 154 to 221°C. On the other hand, the fructan-whey protein mixture demonstrated that nanocapsules have a thermoprotective effect because the decomposition temperature of the encapsulated extract increased 32.1°C. Differential Scanning Calorimetry (DSC) exhibited similar values of the glass transition temperature (Tg) between the capsules with and without extract; which indicates that the polymeric material does not interact with the extract compounds. The photoprotection study revealed that nanocapsules materials protect the jackfruit extract compounds from the UV radiation. Finally, the cell viability on the proliferation of M12.C3.F6 cell line was not affected by powder nanocapsules without jackfruit extract, indicating that capsules are not toxic for these cells. However, microcapsules with jackfruit extract (50μg/ml) were able to inhibit significantly the proliferation cells.

CONCLUSION

The encapsulation process provides thermoprotection and photostability, and the antiproliferative activity of HVBC from jackfruit extract was preserved.

Albanol B from Mulberries Exerts Anti-Cancer Effect through Mitochondria ROS Production in Lung Cancer Cells and Suppresses In Vivo Tumor Growth

Albanol B (ABN-B), an arylbenzofuran derivative isolated from mulberries, has been shown to have anti-Alzheimer’s disease, anti-bacterial and antioxidant activities. The aim of this study was to investigate the anti-cancer effect of this compound against lung cancer cells. The results show that ABN-B inhibited the proliferation of four human lung cancer cell lines (A549, BZR, H1975, and H226) and induced apoptosis, based on the cleavage of caspase-7 and PARP (poly (ADP-ribose) polymerase), as well as the downregulation of Bcl-2. ABN-B also induced cell cycle arrest at G₂/M by down-regulating the expression of CKD1 (cyclin-dependent kinase 1) and cyclin B1, but up-regulating p21 (cyclin-dependent kinase inhibitor 1) expression. Notably, ABN-B increased the production of mitochondrial reactive oxygen species (ROS); however, treatment with mito-TEMPO (a specific mitochondrial antioxidant) blocked ABN-B-induced cell cycle arrest at G₂/M and apoptosis, as well as the up-regulation of p21 and down-regulation of CDK1 and cyclin B1 induced by ABN-B. At the molecular level, ABN-B-induced mitochondrial ROS production increased the phosphorylation levels of AKT (protein kinase B) and ERK1/2 (extracellular signal-regulated kinase 1/2), while the inhibition of these kinases blocked the ABN-B-induced up-regulation of p21 and down-regulation of CDK1 and cyclin B1. Moreover, ABN-B significantly suppressed tumor growth in Ex-3LL (Lewis lung carcinoma) tumor-bearing mice. Taken together, these results suggest that ABN-B can exert an anti-cancer effect by inducing apoptosis and cell cycle arrest at G₂/M through mitochondrial ROS production in lung cancer cells.

Two isoprenylated flavonoids from Dorstenia psilurus activate AMPK, stimulate glucose uptake, inhibit glucose production and lower glycemia

Root extracts of a Cameroon medicinal plant, Dorstenia psilurus, were purified by screening for AMP-activated protein kinase (AMPK) activation in incubated mouse embryo fibroblasts (MEFs). Two isoprenylated flavones that activated AMPK were isolated. Compound 1 was identified as artelasticin by high-resolution electrospray ionization mass spectrometry and 2D-NMR while its structural isomer, compound 2, was isolated for the first time and differed only by the position of one double bond on one isoprenyl substituent. Treatment of MEFs with purified compound 1 or compound 2 led to rapid and robust AMPK activation at low micromolar concentrations and increased the intracellular AMP:ATP ratio. In oxygen consumption experiments on isolated rat liver mitochondria, compound 1 and compound 2 inhibited complex II of the electron transport chain and in freeze-thawed mitochondria succinate dehydrogenase was inhibited. In incubated rat skeletal muscles, both compounds activated AMPK and stimulated glucose uptake. Moreover, these effects were lost in muscles pre-incubated with AMPK inhibitor SBI-0206965, suggesting AMPK dependency. Incubation of mouse hepatocytes with compound 1 or compound 2 led to AMPK activation, but glucose production was decreased in hepatocytes from both wild-type and AMPKβ1-/- mice, suggesting that this effect was not AMPK-dependent. However, when administered intraperitoneally to high-fat diet-induced insulin-resistant mice, compound 1 and compound 2 had blood glucose-lowering effects. In addition, compound 1 and compound 2 reduced the viability of several human cancer cells in culture. The flavonoids we have identified could be a starting point for the development of new drugs to treat type 2 diabetes.

USP53 promotes apoptosis and inhibits glycolysis in lung adenocarcinoma through FKBP51-AKT1 signaling

Despite an overall decline in the incidence of new cases, lung adenocarcinoma continues to be a leading cause of cancer death worldwide. Due to lack of gene expression signatures for risk and prognosis stratification of lung adenocarcinoma, identifying novel molecular biomarkers and therapeutic targets may potentially improve lung adenocarcinoma prognosis and treatment. In the current study, we investigate the role of USP53 in lung adenocarcinoma. Bioinformatics analysis, quantitative reverse transcription polymerase chain reaction, and Western blot were employed to examine patterns of gene expression in human lung adenocarcinoma database, patient samples, and cancer cell lines. Stable cell lines were produced by transducing with USP53 overexpression vector or short hairpin RNA targeting USP53 in the presence and absence of AKT pathway inhibitor LY294002. Functional assays were carried out to examine the impact of USP53 and AKT pathway on lung adenocarcinoma cell viability, apoptosis, and glycolysis in vitro, as well as tumor growth in vivo. The correlation between USP53 and FKBP51 was measured by coimmunoprecipitation and ubiquitination assay. Decreased USP53 levels are a reliable marker of lung adenocarcinoma across published datasets, clinical samples, and cell culture lines. Low USP53 expression is linked to decreased apoptosis and increased metabolic activity, suggesting it acts as a tumor suppressor. USP53 regulates cell apoptosis and glycolysis through the AKT1 pathway. Mechanistically, USP53 deubiquitinates FKBP51, which in turn dephosphorylates AKT1, and ultimately inhibits tumor growth in lung adenocarcinoma. Taken together, our study establishes USP53 as a novel regulator of AKT1 pathway with an important role in tumorigenesis in lung adenocarcinoma.

Inhibition of NADPH Oxidase-Derived Reactive Oxygen Species Decreases Expression of Inflammatory Cytokines in A549 Cells

Various experimental models strongly support the hypothesis that airway inflammation can be caused by oxidative stress. Inflammatory airway diseases like asthma and COPD are characterized by higher levels of ROS and inflammatory cytokines. One of the sources of ROS is NADPH oxidase. Therefore, the aim of the study was to investigate influence of NADPH oxidase inhibition on the expression of IL-6, IL-8, TNF, TSLP, CD59, and PPAR-γ in vitro. A549 cells were incubated with apocynin in three concentrations (0.5 mg/ml, 1 mg/ml, and 3 mg/ml). Cells were trypsinized and RNA isolated after 1 h, 2 h, and 4 h of apocynin incubation at each concentration. Afterwards, reverse transcription was performed to evaluate mRNA expression using real-time PCR. The time-response and dose-response study showed that apocynin significantly influenced the relative expression of chosen genes (IL-6, IL-8, TNF, PPAR-γ, TSLP, and CD59). Apocynin decreased the mRNA expression of TNF-α at all concentrations used, and of IL-6 at concentrations of 1 and 3 mg/ml (p < 0.05). TSLP mRNA expression was also reduced by apocynin after 1 h and 2 h, and CD59 mRNA after 1 h, but only at the highest concentration. The expression of PPAR-γ was reduced after apocynin in the highest concentrations only (p < 0.05). The results might suggest that proinflammatory agents’ expression levels are strongly connected to the presence of oxidative stress generated by NADPH oxidase and this might be at least partially eliminated by anti-oxidative action. Apocynin, as an effective inhibitor of NADPH oxidase, seems to be useful in potential anti-oxidative and anti-inflammatory therapy.

Targeting PI3K/Akt/mTOR signaling pathway by polyphenols: Implication for cancer therapy

Cancer is one of the biggest challenges facing medicine and its cure is regarded to be the Holy Grail of medicine. Therapy in cancer is consisted as various artificial cytotoxic agents and radiotherapy, and recently immunotherapy. Recently much attention has been directed to the use of natural occurring agents in cancer therapy. One of the main group of agents utilized in this regard is polyphenols which are found abundantly in berries, fruits and vegetables. Polyphenols show to exert direct and indirect effects in progression of cancer, angiogenesis, proliferation and enhancing resistance to treatment. One of the cellular pathways commonly affected by polyphenols is PI3K/Akt/mTOR pathway, which has far ranging effects on multiple key aspects of cellular growth, metabolism and death. In this review article, evidence regarding the biology of polyphenols in cancer via PI3K/Akt/mTOR pathway is discussed and their application on cancer pathophysiology in various types of human malignancies is shown.

Interspecies metabolic diversity of artocarpin in vitro mammalian liver microsomes

Artocarpin has shown anti-inflammation and anticancer activities. However, the metabolism differences among different species have not been reported. In this work, we used liver microsomes to explore the metabolic characteristics and possible metabolites of artocarpin among different species. The structures of six metabolites were characterized by LC-MS/MS, and hydroxylated artocarpin was the main metabolite. Enzyme kinetics and depletion studies of artocarpin among different species proved that artocarpin metabolism exhibited significant species differences; rats and monkeys showed a great metabolic ability to artocarpin, and minipigs showed the highest similarity to humans. The in vivo hepatic clearances of artocarpin in rats and humans were predicted that artocarpin was classified as a high-clearance drug in humans and rats. The glucuronidation assay of artocarpin in different liver microsomes also proved that artocarpin metabolism showed significant species difference. These findings will support further pharmacological or toxicological research on artocarpin.Abbreviations: UGT: UDP-glucuronosyltransferase; CYP: cytochrome P450; LC-MS/MS: liquid chromatography-tandem mass spectrometry; HPLC: high-performance liquid chromatography; HLMs: human liver microsomes; MLMs: monkey liver microsomes; RAMs: rabbit liver microsomes; RLMs: rat liver microsomes; DLMs: dog liver microsomes; PLMs: minipig liver microsomes; V_max: maximum velocity; K_m: Michaelis constant; CL_int: intrinsic clearance; CL_H: hepatic clearance; Q_H: hepatic blood flow.

Artocarpin induces cell apoptosis in human osteosarcoma cells through endoplasmic reticulum stress and reactive oxygen species

Osteosarcoma is a malignant primary bone tumor that responds poorly to both chemotherapy and radiation therapy. However, because of side effects and drug resistance in chemotherapy and the insufficiency of an effective adjuvant therapy for osteosarcoma, it is necessary to research novel treatments. This study was the first to investigate the anticancer effects of the flavonoid derivative artocarpin in osteosarcoma. Artocarpin induced cell apoptosis in three human osteosarcoma cell lines-U2OS, MG63, and HOS. Artocarpin was also associated with increased intracellular reactive oxygen species (ROS). Mitochondrial dysfunction was followed by the release of cytochrome c from mitochondria and accompanied by decreased antiapoptotic Bcl-2 and Bcl-xL and increased proapoptotic protein Bak and Bax. Artocarpin triggered endoplasmic reticulum (ER) stress, as indicated by changes in cytosol calcium levels and increased glucose-regulated protein 78 and 94 expressions, and also increased calpains expression and activity. Animal studies revealed a dramatic 40% reduction in tumor volume after 18 days of treatment. This study demonstrated a novel anticancer activity of artocarpin against human osteosarcoma cells and in murine tumor models. In summary, artocarpin significantly induced cell apoptosis through ROS, ER stress, mitochondria, and the caspase pathway, and may thus be a novel anticancer treatment for osteosarcoma.

Mitochondria-Centric Review of Polyphenol Bioactivity in Cancer Models

SIGNIFICANCE

Humans are exposed daily to polyphenols in milligram-to-gram amounts through dietary consumption of fruits and vegetables. Polyphenols are also available as components of dietary supplements for improving general health. Although polyphenols are often advertised as antioxidants to explain health benefits, experimental evidence shows that their beneficial cancer preventing and controlling properties are more likely due to stimulation of pro-oxidant and proapoptotic pathways. Recent Advances: The understanding of the biological differences between cancer and normal cell, and especially the role that mitochondria play in carcinogenesis, has greatly advanced in recent years. These advances have resulted in a wealth of new information on polyphenol bioactivity in cell culture and animal models of cancer. Polyphenols appear to target oxidative phosphorylation and regulation of the mitochondrial membrane potential (MMP), glycolysis, pro-oxidant pathways, and antioxidant (adaptive) stress responses with greater selectivity in tumorigenic cells.

CRITICAL ISSUES

The ability of polyphenols to dissipate the MMP (Δψm) by a protonophore mechanism has been known for more than 50 years. However, researchers focus primarily on the downstream molecular effects of Δψm dissipation and mitochondrial uncoupling. We argue that the physicochemical properties of polyphenols are responsible for their anticancer properties by virtue of their protonophoric and pro-oxidant properties rather than their specific effects on downstream molecular targets.

FUTURE DIRECTIONS

Polyphenol-induced dissipation of Δψm is a physicochemical process that cancer cells cannot develop resistance against by gene mutation. Therefore, polyphenols should receive more attention as agents for cotherapy with cancer drugs to gain synergistic activity. Antioxid. Redox Signal.

The compound 2-(naphthalene-2-thio)-5,8-dimethoxy-1,4-naphthoquinone induces apoptosis via reactive oxygen species-regulated mitogen-activated protein kinase, protein kinase B, and signal transducer and activator of transcription 3 signaling in human gastric cancer cells

Hit, Lead & Candidate Discovery It is reported that 1,4-naphthoquinones and their derivatives have potent antitumor activity in various cancers, although their clinical application is limited by observed side effects. To improve the therapeutic efficacy of naphthoquinones in the treatment of cancer and to reduce side effects, we synthesized a novel naphthoquinone derivative, 2-(naphthalene-2-thio)-5,8-dimethoxy-1,4-naphthoquinone (NTDMNQ). In this study, we explored the effects of NTDMNQ on apoptosis in gastric cancer cells with a focus on reactive oxygen species (ROS) production. Our results demonstrated that NTDMNQ exhibited the cytotoxic effects on gastric cancer cells in a dose-dependent manner. NTDMNQ significantly induced mitochondrial-related apoptosis in AGS cells and increased the accumulation of ROS. However, pre-treatment with N-acetyl-L-cysteine (NAC), an ROS scavenger, inhibited the NTDMNQ-induced apoptosis. In addition, NTDMNQ increased the phosphorylation of p38 kinase and c-Jun N-terminal kinase (JNK) and decreased the phosphorylation of extracellular signal-regulated kinase (ERK), protein kinase B (Akt), and Signal Transducer and Activator of Transcription 3 (STAT3); these effects were blocked by mitogen-activated protein kinase (MAPK) inhibitor and NAC. Taken together, the present findings indicate that NTDMNQ-induced gastric cancer cell apoptosis via ROS-mediated regulation of the MAPK, Akt, and STAT3 signaling pathways. Therefore, NTDMNQ may be a potential treatment for gastric cancer as well as other tumor types.

Mechanism of Lakoochin A Inducing Apoptosis of A375.S2 Melanoma Cells through Mitochondrial ROS and MAPKs Pathway

Malignant melanoma is developed from pigment-containing cells, melanocytes, and primarily found on the skin. Malignant melanoma still has a high mortality rate, which may imply a lack of therapeutic agents. Lakoochin A, a compound isolated from Artocarpus lakoocha and Artocarpus xanthocarpus, has an inhibitory function of tyrosinase activity and melanin production, but the anti-cancer effects are still unclear. In the current study, the therapeutic effects of lakoochin A with their apoptosis functions and possible mechanisms were investigated on A375.S2 melanoma cells. Several methods were applied, including 3-(4,5-Dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide (MTT), flow cytometry, and immunoblotting. Results suggest that lakoochin A attenuated the growth of A375.S2 melanoma cells through an apoptosis mechanism. Lakoochin A first increase the production of cellular and mitochondrial reactive oxygen species (ROSs); mitochondrial ROSs then promote mitogen-activated protein kinases (MAPKs) pathway activation and raise downstream apoptosis-related protein and caspase expression. This is the first study to demonstrate that lakoochin A, through ROS-MAPK, apoptosis-related proteins, caspases cascades, can induce melanoma cell apoptosis and may be a potential candidate compound for treating malignant melanoma.

Quinalizarin Induces Apoptosis through Reactive Oxygen Species (ROS)-Mediated Mitogen-Activated Protein Kinase (MAPK) and Signal Transducer and Activator of Transcription 3 (STAT3) Signaling Pathways in Colorectal Cancer Cells

BACKGROUND Quinalizarin (1,2,5,8-tetrahydroxyanthraquinone) exhibits potentially useful anticancer effects by inducing apoptosis in several types of cancer, but its underlying mechanism of action remains unknown. The present study examined the effects of quinalizarin on the induction of cell cycle arrest, apoptosis, the generation of reactive oxygen species (ROS), other underlying mechanisms, and its role in modifying colorectal cancer cell lines. MATERIAL AND METHODS The MTT assay was used to evaluate the viability of SW480 and HCT-116 cells that had been treated with quinalizarin and 5-fluorouracil (5-FU). Cell cycle arrest and apoptosis were analyzed by flow cytometry. Western blotting was used to investigate the mitochondrial pathway; Akt, MAPK, and STAT3 signaling pathways were also investigated. The relationship between ROS generation and apoptosis was analyzed by flow cytometry and western blotting. RESULTS The results indicated that quinalizarin significantly inhibits the viability of SW480 and HCT-116 cells in a dose-dependent manner. Quinalizarin induced SW480 cell cycle arrest at G2/M by regulating cyclin B1 and CDK1/2. The apoptosis-related protein expression levels of p-p53, Bad, cleaved caspase-3, cleaved PARP and p-JNK were increased in quinalizarin-treated cells, while protein expression levels Bcl-2, p-Akt, p-ERK, and p-STAT3 were decreased. Quinalizarin induced apoptosis in colorectal cancer cells by regulating MAPK and STAT3 signaling pathways via ROS generation. CONCLUSIONS Quinalizarin induces apoptosis via ROS-mediated MAPK/STAT3 signaling pathways.

Extracts of Artocarpus communis Induce Mitochondria-Associated Apoptosis via Pro-oxidative Activity in Human Glioblastoma Cells

Glioblastoma multiforme (GBM) is an extremely aggressive and devastating malignant tumor in the central nervous system. Its incidence is increasing and the prognosis is poor. Artocarpin is a natural prenylated flavonoid with various anti-inflammatory and anti-tumor properties. Studies have shown that artocarpin is associated with cell death of primary glioblastoma cells. However, the in vivo effects and the cellular and molecular mechanisms modulating the anticancer activities of artocarpin remain unknown. In this study, we demonstrated that treating the glioblastoma cell lines U87 and U118 cells with artocarpin induced apoptosis. Artocarpin-induced apoptosis is associated with caspase activation and poly (ADP-ribose) polymerase (PARP) cleavage and is mediated by the mitochondrial pathway. This is associated with mitochondrial depolarization, mitochondrial-derived reactive oxidative species (ROS) production, cytochrome c release, Bad and Bax upregulations, and Bcl-2 downregulation. Artocarpin induced NADPH oxidase/ROS generation plays an important role in the mitochondrial pathway activation. Furthermore, we found artocarpin-induced ROS production in mitochondria is associated with Akt- and ERK1/2 activation. After treatment with artocarpin, ROS causes PI3K/Akt/ERK1/2-induced cell death of these tumor cells. These observations were further verified by the results from the implantation of both U87 and U118 cells into in vivo mouse. In conclusion, our findings suggest that artocarpin induces mitochondria-associated apoptosis of glioma cells, suggesting that artocarpine can be a potential chemotherapeutic agent for future GBM treatment.

Methyl ferulic acid exerts anti-apoptotic effects on L-02 cells via the ROS-mediated signaling pathway

The present study aimed to investigate the anti-apoptotic effects of methyl ferulic acid (MFA) on L-02 cell apoptosis induced by ethanol, and to elucidate the possible underlying mechanisms. L-02 cells were examined after being soaked in ethanol (400 mM) to allow the ethanol to permeate into the cells for 24 h. Cell survival was measured by MTT assay. Cell apoptosis was assessed by both flow cytometry and single-stranded DNA assays. Intracellular reactive oxygen species (ROS) production was determined using the 2',7'-dichlorofluorescein-diacetate dye. The protein expression levels of p38, p-p38, JNK, p-JNK, NADPH oxidase 4 (NOX4), p22, Bax and Bcl-2 were measured by western blot analysis. The mRNA expression levels of NOX4 and p22 were measured by RT-PCR. It was identified that MFA markedly suppressed the ethanol-induced apoptosis and necrosis of L-02 cells. In addition, MFA decreased the expression levels of superoxide dismutase, catalase and phospholipid hydroperoxide gluthione peroxidase, and downregulated the levels of Bax/Bcl-2 and the cleaved forms of caspase-3 in a dose- and time-dependent manner. This indicated that MFA attenuated the apoptosis of L-02 cells. MFA also decreased the elevated mRNA and protein expression levels of Nox4 and p22phox, and the production of intracellular ROS triggered by ethanol. Further analysis demonstrated that MFA significantly attenuated the phosphorylation of JNK and p38, which are major components of the mitogen-activated protein kinase (MAPK) pathways. On the whole, the findings of this study demonstrated that MFA attenuated the apoptotic cell death of L-02 cells by reducing the generation of ROS and inactivating the MAPK pathways.

A novel synthetic curcumin derivative MHMM-41 induces ROS-mediated apoptosis and migration blocking of human lung cancer cells A549

Many curcumin derivatives were produced and characterized to improve the physiochemical instability and low solubility of curcumin. Here, MHMM-41 (a novel curcumin derivative) was used to treat non-small lung cancer cells of human (known as A549) and to identify its anti-proliferative activities. Our results suggested that MHMM-41 display no significant cytotoxicity toward normal human lung fibroblast 2BS cells and mouse embryonal fibroblast 3T3 cells. It also had better anti-proliferative activity than curcumin in A549 cells. Further study showed a significant increase of apoptotic A549 cells in time and dose dependent manners. The activation of caspase-3, 8, 9, 12, Bax and PARP proteins were detected. Consequently, MHMM-41 treatment led to the reduction of mitochondrial membrane potential by JC-1 staining and characteristic nuclei fragmentation by Hoechst 33,342 staining, respectively, which showed that A549 apoptosis could be triggered by the extrinsic and intrinsic mitochondrial pathways. The release of ROS was also measured by flow cytometry. Further, wound healing assay and transwell experiments confirmed the anti-migration ability of MHMM-41 in A549 cells. Our current study suggested the potentials of MHMM-41 to inhibit the A549 cell proliferation. However, the intensive mechanical research on the anti-proliferation of A549 cells needs to be performed in the future.

Cloning of a novel lectin from Artocarpus lingnanensis that induces apoptosis in human B-lymphoma cells

We isolated a novel lectin (Artocarpus nitidus subsp. lingnanensis lectin, ALL) from Artocarpus nitidus subsp. lingnanensis and showed its mitogenic activities. In this study, we determined the amino acid sequence of ALL by cDNA sequencing. ALL cDNA (933 bp) contains a 657-bp open reading frame (ORF), which encodes a protein with 218 amino acids. ALL shares high sequence similarities with Jacalin and Morniga G and belongs to jacalin-related lectin family. We also examined the antitumor activity of ALL using Raji, a human B-lymphoma cell line. ALL exhibits a strong binding affinity to cell membrane, which can be effectively inhibited by N-acetyl-D-galactosamine (GalNAc). ALL inhibits Raji cell proliferation in a time- and dose-dependent manner through apoptosis, evidenced by morphological changes, phosphatidylserine externalization, poly ADP-ribose polymerase (PARP) cleavage, Bcl-2 down-regulation, and caspase-3 activation. We further showed that the activation of p38 mitogen-activated protein kinase (MAPK) signaling pathways is required for the pro-apoptotic activity of ALL.

Auriculasin-induced ROS causes prostate cancer cell death via induction of apoptosis

Recent studies have demonstrated that natural agents targeting the accumulation of reactive oxygen species (ROS) that selectively kill, leaving normal cells undamaged, can suppress prostate cancer. Here, we show that auriculasin, derived from Flemingia philippinensis, induces significant cell death and apoptosis via ROS generation in prostate cancer cells. Auriculasin treatment resulted in selective apoptotic cell death in LNCaP prostate cancer cells, characterized by DNA fragmentation, accumulation of sub-G1 cell population, cleavage of poly (ADP-ribose) polymerase (PARP), regulation of Bax/Bcl-2 ratio, increase of cytosolic apoptosis-inducing factor (AIF) and endonuclease G (EndoG), in addition to inhibiting tumor growth in a xenograft mouse model. Interestingly, auriculasin-induced apoptosis did not result in caspase-3, -8, and -9 activations. We found that auriculasin treatment decreased phosphorylation of AKT/mTOR/p70s6k in a dose- and time-dependent manner. Further, cellular ROS levels increased in LNCaP cells treated with auriculasin and blocking ROS accumulation with ROS scavengers resulted in inhibition of auriculasin-induced PARP cleavage, AIF increase, upregulation of Bax/Bcl-2 ratio, and decrease in AKT/mTOR phosphorylation. Taken together, these data suggest that auriculasin targets ROS-mediated caspase-independent pathways and suppresses PI3K/AKT/mTOR signaling, which leads to apoptosis and decreased tumor growth.

Costunolide enhances doxorubicin-induced apoptosis in prostate cancer cells via activated mitogen-activated protein kinases and generation of reactive oxygen species

The management of castration-resistant prostate cancer (CRPC) is challenging, attributable to a lack of efficacious therapies. Chemotherapy is one of the most important treatments for CRPC. Doxorubicin has been extensively used in many different tumors and is often combined with other drugs to enhance effects and reduce toxicity. Costunolide is a natural sesquiterpene lactone with anti-cancer properties. In this study, we first demonstrated that the combination of costunolide and doxorubicin induced apoptosis significantly more than either drug alone in prostate cancer cell lines. Costunolide combined with doxorubicin induced mitochondria-mediated apoptosis through a loss of mitochondrial membrane potential and modulation of Bcl-2 family proteins. We found that this drug combination significantly increased the production of reactive oxygen species (ROS), as well as phosphorylation of c-jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinases, which play upstream roles in mitochondria-mediated apoptosis. Further studies showed that N-acetyl cysteine blocked JNK and p38 phosphorylation, suggesting that ROS were upstream activators of JNK and p38. However, a JNK inhibitor, but not a p38 inhibitor, blocked the increase in ROS observed in cells treated with a combination of costunolide and doxorubicin, suggesting that ROS and JNK could activate each other. In vivo, inhibition of tumor growth and induction of apoptosis were greater in mice treated with the costunolide and doxorubicin combination than in mice treated with either drug alone, without an increase in toxicity. Therefore, we suggested that costunolide in combination with doxorubicin was a new potential chemotherapeutic strategy for treating prostate cancer.

(S)-crizotinib induces apoptosis in human non-small cell lung cancer cells by activating ROS independent of MTH1

BACKGROUND

Non-small cell lung cancer (NSCLC) accounts for approximately 80-85% of all lung cancers and is usually diagnosed at an advanced stage with poor prognosis. Targeted therapy has produced unprecedented outcomes in patients with NSCLC as a number of oncogenic drivers have been found. Crizotinib, a selective small-molecule inhibitor, has been widely used for the treatment of NSCLC patients with ALK gene rearrangements. A recent study has also shown that (S)-enantiomer of crizotinib exhibits anticancer activity by targeting the protein mutT homologue (MTH1). Since this discovery, contradictory studies have cast a doubt on MTH1 as a therapeutic target of (S)-crizotinib.

METHODS

NCI-H460, H1975, and A549 cells and immunodeficient mice were chosen as a model to study the (S)-crizotinib treatment. The changes induced by (S)-crizotinib treatment in cell viability, apoptosis as well as ROS, and endoplasmic reticulum stress pathway in the cells were analyzed by MTT assay, FACSCalibur, Western blotting, ROS imaging and electron microscopy.

RESULTS

Here, we report that MTH1 does not affect survival of NSCLC cells. We found that (S)-crizotinib induces lethal endoplasmic reticulum stress (ER) response in cultured NSCLC cells by increasing intracellular levels of reactive oxygen species (ROS). Blockage of ROS production markedly reversed (S)-crizotinib-induced ER stress and cell apoptosis, independent of MTH1. We confirmed these findings in NSCLC xenograft studies and showed that (S)-crizotinib-induced ER stress and cell apoptosis.

CONCLUSIONS

Our results reveal a novel antitumor mechanism of (S)-crizotinib in NSCLC which involves activation of ROS-dependent ER stress apoptotic pathway and is independent of MTH1 inhibition.

Anti-inflammatory effects of millet bran derived-bound polyphenols in LPS-induced HT-29 cell via ROS/miR-149/Akt/NF-κB signaling pathway

The pro-inflammatory and anti-inflammatory maladjustment has been acknowledged as one of the chief causations of inflammatory diseases and even cancers. Previous studies showed that plant-derived polyphenolic compounds were the most potent anti-oxidant and anti-inflammatory agents among all natural compounds. The present study indicates that bound polyphenols of inner shell (BPIS) from foxtail millet bran can display anti-inflammatory effects in LPS-induced HT-29 cells and in nude mice. Mechanistically, BPIS restrained the level of various pro-inflammatory cytokines (IL-1β, IL-6, IL-8), and enhanced the expression level of anti-inflammatory cytokine (IL-10) by blocking the nuclear factor-kappaB (NF-κB)-p65 nuclear translocation. Further, we found the elevated miR-149 expression by BPIS-induced ROS accumulation, directly targeted the Akt expression to block NF-κB nuclear translocation. Taken together, these novel findings provide new insights into the development of BPIS as an anti-inflammatory agent via the signaling cascade of ROS/miR-149/Akt/NF-κB axis.