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Showing papers on "Apoptosis published in 2018"


Journal ArticleDOI
TL;DR: Promising new anticancer therapies are plant-derived compounds that exhibit anticancer activity through activating the apoptotic pathway, the cell’s natural mechanism for death.
Abstract: Apoptosis, the cell’s natural mechanism for death, is a promising target for anticancer therapy. Both the intrinsic and extrinsic pathways use caspases to carry out apoptosis through the cleavage of hundreds of proteins. In cancer, the apoptotic pathway is typically inhibited through a wide variety of means including overexpression of antiapoptotic proteins and under-expression of proapoptotic proteins. Many of these changes cause intrinsic resistance to the most common anticancer therapy, chemotherapy. Promising new anticancer therapies are plant-derived compounds that exhibit anticancer activity through activating the apoptotic pathway.

818 citations


Journal ArticleDOI
TL;DR: Current understanding of the mechanisms by which p53 induces cell death is discussed and how this affects p53-mediated tumour suppression and the response of malignant cells to anticancer therapy is discussed.
Abstract: The tumour suppressor gene TP53 is mutated in ~50% of human cancers. In addition to its function in tumour suppression, p53 also plays a major role in the response of malignant as well as nontransformed cells to many anticancer therapeutics, particularly those that cause DNA damage. P53 forms a homotetrameric transcription factor that is reported to directly regulate ~500 target genes, thereby controlling a broad range of cellular processes, including cell cycle arrest, cell senescence, DNA repair, metabolic adaptation and cell death. For a long time, induction of apoptotic death in nascent neoplastic cells was regarded as the principal mechanism by which p53 prevents tumour development. This concept has, however, recently been challenged by the findings that in striking contrast to Trp53-deficient mice, gene-targeted mice that lack the critical effectors of p53-induced apoptosis do not develop tumours spontaneously. Remarkably, even mice lacking all mediators critical for p53-induced apoptosis, G1/S boundary cell cycle arrest and cell senescence do not develop any tumours spontaneously. In this review we discuss current understanding of the mechanisms by which p53 induces cell death and how this affects p53-mediated tumour suppression and the response of malignant cells to anticancer therapy.

699 citations


Journal ArticleDOI
TL;DR: When apoptotic cells are not efficiently engulfed by macrophages, they undergo secondary necrosis and release intracellular materials that represent a damage-associated molecular pattern, which may lead to a systemic lupus-like autoimmune disease.
Abstract: The human body generates 10-100 billion cells every day, and the same number of cells die to maintain homeostasis in our body. Cells infected by bacteria or viruses also die. The cell death that occurs under physiological conditions mainly proceeds by apoptosis, which is a noninflammatory, or silent, process, while pathogen infection induces necroptosis or pyroptosis, which activates the immune system and causes inflammation. Dead cells generated by apoptosis are quickly engulfed by macrophages for degradation. Caspases are a large family of cysteine proteases that act in cascades. A cascade that leads to caspase 3 activation mediates apoptosis and is responsible for killing cells, recruiting macrophages, and presenting an "eat me" signal(s). When apoptotic cells are not efficiently engulfed by macrophages, they undergo secondary necrosis and release intracellular materials that represent a damage-associated molecular pattern, which may lead to a systemic lupus-like autoimmune disease.

570 citations


Journal ArticleDOI
23 Feb 2018-Science
TL;DR: This study provides a mechanistic description of mtDNA release from mitochondria during apoptosis, and suggests that mtDNA is found outside the mitochondria—and, indeed, outside the cell—in a wide range of circumstances.
Abstract: Mitochondrial apoptosis is mediated by BAK and BAX, two proteins that induce mitochondrial outer membrane permeabilization, leading to cytochrome c release and activation of apoptotic caspases. In the absence of active caspases, mitochondrial DNA (mtDNA) triggers the innate immune cGAS/STING pathway, causing dying cells to secrete type I interferon. How cGAS gains access to mtDNA remains unclear. We used live-cell lattice light-sheet microscopy to examine the mitochondrial network in mouse embryonic fibroblasts. We found that after BAK/BAX activation and cytochrome c loss, the mitochondrial network broke down and large BAK/BAX pores appeared in the outer membrane. These BAK/BAX macropores allowed the inner mitochondrial membrane to herniate into the cytosol, carrying with it mitochondrial matrix components, including the mitochondrial genome. Apoptotic caspases did not prevent herniation but dismantled the dying cell to suppress mtDNA-induced innate immune signaling.

491 citations


Journal ArticleDOI
TL;DR: Syzygium cumini extract inhibits the proliferation ofOSCC cells and induces apoptosis through ROS accumulation and therefore, it could be used for the prevention of OSCC.
Abstract: Background Syzygium cumini (L.) Skeels (jambolan) is commonly used in Indian traditional medicine to treat a variety of diseases such as obesity, diabetes etc. The cytotoxic potential of S. cumini (SC) against oral cancer cell line remains elusive. Therefore, in this study, we evaluated the cytotoxic effect of S. cumini in human oral squamous cell carcinoma (OSCC) cell line (SCC-25 cells). Material and methods Oral squamous cell carcinoma cells are treated with different concentrations (10, 20, and 40 μg/mL) of S. cumuni for 24 hours and cytotoxicity was analyzed by MTT assay. The intracellular reactive oxygen species (ROS) was measured using the indicator dye, 2',7'-dichlorofluorescin diacetate staining. Apoptosis-related morphological changes were evaluated by dual acridine orange/ethidium bromide (AO/EB) fluorescent staining and phosphatidylserine externalization was measured by annexin V assays. The protein and gene expression of cadherin-1 was evaluated by western blotting and PCR analysis. Results Syzygium cumini treatments caused cytotoxicity of OSCC cell line and induced intracellular ROS accumulation. This treatment also caused apoptosis-related morphological changes and externalization of phosphatidylserine in OSCC cells. Further, S. cumini treatments increased protein and gene expression of cadherin-1. Conclusion Syzygium cumini extract inhibits the proliferation of OSCC cells and induces apoptosis through ROS accumulation and therefore, it could be used for the prevention of OSCC.

456 citations


Journal ArticleDOI
TL;DR: The role of autophagy in cell death is reviewed and howAutophagy interfaces with other forms of cell death including apoptosis and necrosis is examined, as well as engulfment and inflammation.
Abstract: Autophagy influences cell survival through maintenance of cell bioenergetics and clearance of protein aggregates and damaged organelles Several lines of evidence indicate that autophagy is a multifaceted regulator of cell death, but controversy exists over whether autophagy alone can drive cell death under physiologically relevant circumstances Here, we review the role of autophagy in cell death and examine how autophagy interfaces with other forms of cell death including apoptosis and necrosis

439 citations


Journal ArticleDOI
TL;DR: Despite necroptosis being challenging to detect in vivo, there is accumulating evidence that this cell death form is a pathogenically relevant driver in several liver diseases that were associated with apoptosis.
Abstract: Cell death represents a basic biological paradigm that governs outcomes and long-term sequelae in almost every hepatic disease condition Acute liver failure is characterized by massive loss of parenchymal cells but is usually followed by restitution ad integrum By contrast, cell death in chronic liver diseases often occurs at a lesser extent but leads to long-term alterations in organ architecture and function, contributing to chronic hepatocyte turnover, the recruitment of immune cells and activation of hepatic stellate cells These chronic cell death responses contribute to the development of liver fibrosis, cirrhosis and cancer It has become evident that, besides apoptosis, necroptosis is a highly relevant form of programmed cell death in the liver Differential activation of specific forms of programmed cell death might not only affect outcomes in liver diseases but also offer novel opportunities for therapeutic intervention Here, we summarize the underlying molecular mechanisms and open questions about disease-specific activation and roles of programmed cell death forms, their contribution to response signatures and their detection We focus on the role of apoptosis and necroptosis in acute liver injury, nonalcoholic fatty liver disease (NAFLD), nonalcoholic steatohepatitis (NASH) and liver cancer, and possible translations into clinical applications

308 citations


Journal ArticleDOI
TL;DR: It is demonstrated that the lncRNA NKILA is expressed by tumor-associated cytotoxic T cells, and this predisposes them to activation-induced cell death and escape of tumors from immunologically mediated destruction.
Abstract: Activation-induced cell death (AICD) of T lymphocytes can be exploited by cancers to escape immunological destruction. We demonstrated that tumor-specific cytotoxic T lymphocytes (CTLs) and type 1 helper T (TH1) cells, rather than type 2 helper T cells and regulatory T cells, were sensitive to AICD in breast and lung cancer microenvironments. NKILA, an NF-κB-interacting long noncoding RNA (lncRNA), regulates T cell sensitivity to AICD by inhibiting NF-κB activity. Mechanistically, calcium influx in stimulated T cells via T cell-receptor signaling activates calmodulin, thereby removing deacetylase from the NKILA promoter and enhancing STAT1-mediated transcription. Administering CTLs with NKILA knockdown effectively inhibited growth of breast cancer patient-derived xenografts in mice by increasing CTL infiltration. Clinically, NKILA overexpression in tumor-specific CTLs and TH1 cells correlated with their apoptosis and shorter patient survival. Our findings underscore the importance of lncRNAs in determining tumor-mediated T cell AICD and suggest that engineering lncRNAs in adoptively transferred T cells might provide a novel antitumor immunotherapy.

278 citations


Journal ArticleDOI
TL;DR: The existence of a unique radiation-responsive ‘p53 gateway’ preventing miR-31-mediated apoptosis in Sf9 cells is shown, which may have significant implications for effectively modulating the mammalian cell radioresistance.
Abstract: Recently, we have demonstrated that microRNA-31 (miR-31) overexpression is inherent to radiation-induced cell death in the highly radioresistant Sf9 insect cells, and regulates pro-apoptotic Bax translocation to mitochondria. In the present study, we report that at sub-lethal radiation doses for Sf9 cells, miR-31 is significantly downregulated and is tightly regulated by an unusual mechanism involving p53. While ectopic overexpression of a well-conserved Sfp53 caused typical apoptosis, radiation-induced p53 accumulation observed selectively at sub-lethal doses failed to induce cell death. Further investigation of this paradoxical response revealed an intriguing phenomenon that sub-lethal radiation doses result in accumulation of a 'hyper-phosphorylated' Sfp53, which in turn binds to miR-31 genomic location and suppresses its expression to prevent cell death. Interestingly, priming cells with sub-lethal doses even prevented the apoptosis induced by lethal radiation or ectopic Sfp53 overexpression. On the other hand, silencing p53 increased radiation-induced cell death by inhibiting miR-31 downregulation. This study thus shows the existence of a unique radiation-responsive 'p53 gateway' preventing miR-31-mediated apoptosis in Sf9 cells. Since Sfp53 has a good functional homology with human p53, this study may have significant implications for effectively modulating the mammalian cell radioresistance.

236 citations


Journal ArticleDOI
01 Dec 2018-Thorax
TL;DR: ECVC is significantly more toxic to AMs than non-vaped ECL and inhibition of phagocytosis suggests users may suffer from impaired bacterial clearance, and is cautioned against the widely held opinion that e-cigarettes are safe.
Abstract: Objective Vaping may increase the cytotoxic effects of e-cigarette liquid (ECL). We compared the effect of unvaped ECL to e-cigarette vapour condensate (ECVC) on alveolar macrophage (AM) function. Methods AMs were treated with ECVC and nicotine-free ECVC (nfECVC). AM viability, apoptosis, necrosis, cytokine, chemokine and protease release, reactive oxygen species (ROS) release and bacterial phagocytosis were assessed. Results Macrophage culture with ECL or ECVC resulted in a dose-dependent reduction in cell viability. ECVC was cytotoxic at lower concentrations than ECL and resulted in increased apoptosis and necrosis. nfECVC resulted in less cytotoxicity and apoptosis. Exposure of AMs to a sub-lethal 0.5% ECVC/nfECVC increased ROS production approximately 50-fold and significantly inhibited phagocytosis. Pan and class one isoform phosphoinositide 3 kinase inhibitors partially inhibited the effects of ECVC/nfECVC on macrophage viability and apoptosis. Secretion of interleukin 6, tumour necrosis factor α, CXCL-8, monocyte chemoattractant protein 1 and matrix metalloproteinase 9 was significantly increased following ECVC challenge. Treatment with the anti-oxidant N-acetyl-cysteine (NAC) ameliorated the cytotoxic effects of ECVC/nfECVC to levels not significantly different from baseline and restored phagocytic function. Conclusions ECVC is significantly more toxic to AMs than non-vaped ECL. Excessive production of ROS, inflammatory cytokines and chemokines induced by e-cigarette vapour may induce an inflammatory state in AMs within the lung that is partly dependent on nicotine. Inhibition of phagocytosis also suggests users may suffer from impaired bacterial clearance. While further research is needed to fully understand the effects of e-cigarette exposure in humans in vivo, we caution against the widely held opinion that e-cigarettes are safe.

196 citations


Journal ArticleDOI
TL;DR: This review highlights the recent literature on ferroptotic and apoptotic agent interactions through the ER stress–mediated PERK–eIF2α–ATF4–CHOP–PUMA pathway and implicates combined treatment to effectively enhance tumoricidal efficacy as a novel therapeutic strategy for cancer.
Abstract: Since its discovery in 2012, ferroptosis has been well characterized by the accumulation of lipid peroxides due to the failure of glutathione-dependent antioxidant defenses. It is known as an iron-dependent form of programmed cell death, which is distinct from other forms of cell death such as apoptosis and necrosis. Nonetheless, little is known about the ferroptotic agent-induced endoplasmic reticulum (ER) stress response and its role in cell death. Recent studies reveal that the ferroptotic agent-induced ER stress response plays an important role in the cross-talk between ferroptosis and other types of cell death. Ferroptotic agents induce the unfolded protein response and subsequently ER stress-mediated activation of the PERK-eIF2α-ATF4-CHOP pathway. CHOP (C/EBP homologous protein) signaling pathway-mediated p53-independent PUMA (p53 upregulated modulator of apoptosis) expression is involved in the synergistic interaction between ferroptosis and apoptosis. This review highlights the recent literature on ferroptotic and apoptotic agent interactions through the ER stress-mediated PERK-eIF2α-ATF4-CHOP-PUMA pathway and implicates combined treatment to effectively enhance tumoricidal efficacy as a novel therapeutic strategy for cancer. Mol Cancer Res; 16(7); 1073-6. ©2018 AACR.

Journal ArticleDOI
TL;DR: The results revealed that honokiol caused G0/G1 phase arrest, induced apoptosis, and autophagy via the ROS/ERK1/2 signaling pathway in human osteosarcoma cells, which makes it a promising candidate for development of antitumor drugs targeting osteosARcoma.
Abstract: Osteosarcoma is the most common primary malignant tumor of bone, the long-term survival of which has stagnated in the past several decades. In the present study, we investigated the anticancer effect of honokiol (HNK), an active component isolated and purified from the magnolia officinalis on human osteosarcoma cells. Our results showed that honokiol caused dose-dependent and time-dependent cell death in human osteosarcoma cells. The types of cell death induced by honokiol were primarily autophagy and apoptosis. Furthermore, honokiol induced G0/G1 phase arrest, elevated the levels of glucose-regulated protein (GRP)−78, an endoplasmic reticular stress (ERS)-associated protein, and increased the production of intracellular reactive oxygen species (ROS). In contrast, reducing production of intracellular ROS using N-acetylcysteine, a scavenger of ROS, concurrently suppressed honokiol-induced cellular apoptosis, autophagy, and cell cycle arrest. Consequently, honokiol stimulated phosphorylation of extracellular signal-regulated kinase (ERK)1/2. Furthermore, pretreatment of osteosarcoma cells with PD98059, an inhibitor of ERK1/2, inhibited honokiol-induced apoptosis and autophagy. Finally, honokiol suppressed tumor growth in the mouse xenograft model. Taken together, our results revealed that honokiol caused G0/G1 phase arrest, induced apoptosis, and autophagy via the ROS/ERK1/2 signaling pathway in human osteosarcoma cells. Honokiol is therefore a promising candidate for development of antitumor drugs targeting osteosarcoma.

Journal ArticleDOI
Yubin Wang1, Bo Yin1, Dinuo Li1, Guijun Wang1, Xiangdong Han1, Xuejun Sun1 
TL;DR: GSDME switches chemotherapy drug-induced caspase-3 dependent apoptosis into pyroptosis in gastric cancer cells, and GSDME knockout by CRISPR-Cas9 switched 5-FU induced pyroPTosis into apoptosis in SGC-7901.

Journal ArticleDOI
TL;DR: The inhibition of IL‐6/STAT3 signaling pathway mediated by anti‐IL6 was found to reduce tumor formation of HCC cells co‐cultured with M1‐ or M2‐type macrophages and lung metastases.
Abstract: Human cancers, including hepatocellular carcinoma (HCC), are characterized by a high degree of drug resistance in chemotherapy. However, the underlying molecular mechanism remains unknown. To the role of interleukin-6 (IL-6)/signal transducer and activator of transcription 3 (STAT3) signaling pathway in the regulation of macrophage polarization, M1-type and M2-type macrophages were separately induced using lipopolysaccharide and interleukin-4 (IL-4), and we found that the IL-6/STAT3 signaling pathway was inhibited in M1-type macrophages but activated in M2-type macrophages. After anti-IL-6-treated macrophages were separately induced by lipopolysaccharide and IL-4, we found that the inhibition of IL-6/STAT3 signaling pathway turned macrophages into M1-type. Co-culture with M1-type macrophages reduced HCC cell viability, proliferation, invasion, migration, drug resistance, but increased apoptosis. Co-culture with M2-type macrophages yielded reciprocal results. The inhibition of IL-6/STAT3 signaling pathway mediated by anti-IL6 was shown to significantly enhance the effects of M1-type macrophages on HCC cells and rescue HCC cells from co-culture with M2-type macrophages. Tumor xenografts of co-cultured HCC cells were established in nude mice and the results showed that the inhibition of IL-6/STAT3 signaling pathway mediated by anti-IL6 was found to reduce tumor formation of HCC cells co-cultured with M1- or M2-type macrophages and lung metastases. The current study reveals a novel mechanism of IL-6/STAT3 signaling pathway in the regulation of macrophage polarization, thus contributing to HCC metastasis and drug resistance in chemotherapy.

Journal ArticleDOI
TL;DR: This study demonstrated that the GSDMD protein levels were significantly upregulated in NSCLC compared to these levels in matched adjacent tumor specimens, and revealed a crosstalk between pyroptotic signaling and apoptosis in tumor cells.
Abstract: Gasdermin D (GSDMD) is a newly discovered pyroptosis executive protein, which can be cleaved by inflammatory caspases and is essential for secretion of IL-1β, making it a critical mediator of inflammation. However, the precise role of GSDMD in carcinogenesis remains nearly unknown. Considering the vital role of inflammation in tumorigenesis, we investigated the biological function of GSDMD in non-small cell lung cancer (NSCLC). Our study demonstrated that the GSDMD protein levels were significantly upregulated in NSCLC compared to these levels in matched adjacent tumor specimens. Higher GSDMD expression was associated with aggressive traits including larger tumor size and more advanced tumor-node-metastasis (TNM) stages. In addition, high GSDMD expression indicated a poor prognosis in lung adenocarcinoma (LUAD), but not in squamous cell carcinoma (LUSC). Knockdown of GSDMD restricted tumor growth in vitro and in vivo. Notably, intrinsic and extrinsic activation of pyroptotic (NLRP3/caspase-1) signaling in GSDMD-deficient tumor cells induced another type of programmed cell death (apoptosis), instead of pyroptosis. GSDMD depletion activated the cleavage of caspase-3 and PARP, and promoted cancer cell death via intrinsic mitochondrial apoptotic pathways. In addition, co-expression analyses indicated a correlation between GSDMD and EGFR/Akt signaling. Collectively, our results revealed a crosstalk between pyroptotic signaling and apoptosis in tumor cells. Knockdown of GSDMD attenuated tumor proliferation by promoting apoptosis and inhibiting EGFR/Akt signaling in NSCLC. In conclution, GSDMD is an independent prognostic biomarker for LUAD.

Journal ArticleDOI
TL;DR: It is indicated that bezafibrate increases or maintains the number of functional CTLs by activating mitochondrial and cellular metabolism, leading in turn to enhanced antitumor immunity during PD-1 blockade.
Abstract: Although PD-1 blockade cancer immunotherapy has shown potential for a wide range of patients with cancer, its efficacy is limited, in part, due to the loss of effector cytotoxic T lymphocytes (CTLs) via terminal differentiation-induced apoptosis. We previously demonstrated that mitochondrial activation, by the agonists of peroxisome proliferator-activated receptor γ (PPARγ) coactivator 1-α (PGC-1α)/transcription factor complexes, had synergistic effects with a PD-1-blocking monoclonal antibody in a mouse tumor model. In the current study, we examined the molecular mechanism of the synergistic effects of bezafibrate, an agonist of PGC-1α/ PPAR complexes, which enhanced the tumoricidal effects of PD-1 blockade. Bezafibrate activated CTL mitochondria and upregulated oxidative phosphorylation as well as glycolysis, resulting in more proliferation of naive T cells and improved effector function in CTLs. Bezafibrate also increased fatty acid oxidation (FAO) and mitochondrial respiratory capacity, which supports the extra energy demands of cells in emergencies, allowing cell survival. Carnitine palmitoyl transferase 1 (Cpt1), which is needed for FAO, and Bcl2 were both upregulated. Cpt1 and Bcl2 can form a complex to prevent apoptosis of CTLs. Together, these results indicate that bezafibrate increases or maintains the number of functional CTLs by activating mitochondrial and cellular metabolism, leading in turn to enhanced antitumor immunity during PD-1 blockade. Cancer Immunol Res; 6(11); 1375-87. ©2018 AACR.

Journal ArticleDOI
TL;DR: An overview of methods often being used for detecting DNA fragmentation as one of the most specific findings in apoptosis is provided, including optimized approaches, techniques, and limitations.
Abstract: Apoptosis has been recognized as a type of programmed cell death connected with characteristic morphological and biochemical changes in cells. This programmed cell death plays an important role in the genesis of a number of physiological and pathological processes. Thus, it can be very important to detect the signs of apoptosis in a study of cellular metabolism. The present paper provides an overview of methods often being used for detecting DNA fragmentation as one of the most specific findings in apoptosis. To date, three routine assays have been developed for detecting DNA fragmentation: DNA ladder assay, TUNEL assay, and comet assay. All these methods differ in their principles for detecting DNA fragmentation. DNA ladder assay detects the characteristic "DNA ladder" pattern formed during internucleosomal cleavage of DNA. Terminal deoxynUcleotidyl transferase Nick-End Labeling (TUNEL) assay detects DNA strand breaks using terminal deoxynucleotidyl transferase catalyzing attachment of modified deoxynucleotides on the DNA strand breaks. Comet assay can be used for detecting nucleus breakdown producing single/double-strand DNA breaks. The aim of this review is to describe the present knowledge on these three methods, including optimized approaches, techniques, and limitations.

Journal ArticleDOI
TL;DR: The biosynthesized AgNPs-induced cell death in HeLA cells suggested the anticancer potential of ND-AgNPs, and they may be used to treat the cervical cancer cells.
Abstract: In this study, silver nanoparticles (AgNPs) were synthesized using aqueous extract of Nepeta deflersiana plant. The prepared AgNPs (ND-AgNPs) were examined by ultraviolet-visible spectroscopy, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscope (SEM), and energy dispersive spectroscopy (EDX). The results obtained from various characterizations revealed that average size of synthesized AgNPs was 33 nm and in face-centered-cubic structure. The anticancer potential of ND-AgNPs was investigated against human cervical cancer cells (HeLa). The cytotoxic response was assessed by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT), neutral red uptake (NRU) assays, and morphological changes. Further, the influence of cytotoxic concentrations of ND-AgNPs on oxidative stress markers, reactive oxygen species (ROS) generation, mitochondrial membrane potential (MMP), cell cycle arrest and apoptosis/necrosis was studied. The cytotoxic response observed was in a concentration-dependent manner. Furthermore, the results also showed a significant increase in ROS and lipid peroxidation (LPO), along with a decrease in MMP and glutathione (GSH) levels. The cell cycle analysis and apoptosis/necrosis assay data exhibited ND-AgNPs-induced SubG1 arrest and apoptotic/necrotic cell death. The biosynthesized AgNPs-induced cell death in HeLA cells suggested the anticancer potential of ND-AgNPs. Therefore, they may be used to treat the cervical cancer cells.

Journal ArticleDOI
TL;DR: It is demonstrated that Art inhibits chondrocyte proliferation and accelerates apoptosis and autophagy in RA rats through the PI3K/AKT/mTOR signaling pathway.

Journal ArticleDOI
TL;DR: Taken together, these findings represent a novel mechanism by which downregulation of PI3Kγ-p110 and consequent interruption ofPI3K/AKT/mTOR/p70S6K/ULK signaling pathway might play a critical functional role in these flavonoids-induced cell cycle arrest at G2/M phase, apoptosis, and autophagy.
Abstract: Anticancer activities of flavonoids derived from Tephroseris kirilowii (Turcz.) Holub. were evaluated in human cancer cells. We isolated and identified, for the first time, eight flavonoids from T. kirilowii and found that three of them (IH: isorhamnetin, GN: genkwanin, and Aca: acacetin) inhibited cell proliferation in a variety of human cancer cell lines. These active flavonoids caused cell cycle arrest at G2/M phase and induced apoptosis and autophagy in human breast cancer cells. Molecular docking revealed that these flavonoids dock in the ATP binding pocket of PI3Kγ. Importantly, treatment with these flavonoids decreased the levels of PI3Kγ-p110, phospho-PI3K, phospho-AKT, phospho-mTOR, phospho-p70S6K, and phospho-ULK. Pretreatment with PI3Kγ specific inhibitor AS605240 potentiated flavonoids-mediated inactivation of AKT, mTOR, p70S6K, ULK, and apoptosis. Taken together, these findings represent a novel mechanism by which downregulation of PI3Kγ-p110 and consequent interruption of PI3K/AKT/mTOR/p70S6K/ULK signaling pathway might play a critical functional role in these flavonoids-induced cell cycle arrest at G2/M phase, apoptosis, and autophagy. Our studies provide novel insights into the anticancer activities of selected flavonoids and their potential uses in anticancer therapy.

Journal ArticleDOI
TL;DR: These results pinpoint GSDME-dependent pyroptosis as a previously unrecognized mechanism of action for molecular targeted agents to eradicate oncogene-addicted neoplastic cells, which may have important implications for the clinical development and optimal application of anticancer therapeutics.
Abstract: Purpose: The induced death signals following oncogene inhibition underlie clinical efficacy of molecular targeted therapies against human cancer, and defects of intact cell apoptosis machinery often lead to therapeutic failure. Despite potential importance, other forms of regulated cell death triggered by pharmacologic intervention have not been systematically characterized. Experimental Design: Pyroptotic cell death was assessed by immunoblot analysis, phase-contrast imaging, scanning electron microscopy, and flow cytometry. Tumor tissues of patients with lung cancer were analyzed using IHC. Functional impact of pyroptosis on drug response was investigated in cell lines and xenograft models. Results: We showed that diverse small-molecule inhibitors specifically targeting KRAS-, EGFR-, or ALK-driven lung cancer uniformly elicited robust pyroptotic cell death, in addition to simultaneously invoking cellular apoptosis. Upon drug treatment, the mitochondrial intrinsic apoptotic pathway was engaged and the mobilized caspase-3 protease cleaved and activated gasdermin E (GSDME, encoded by DFNA5), which permeabilized cytoplasmic membrane and executed cell-lytic pyroptosis. GSDME displayed ubiquitous expression in various lung cancer cell lines and clinical specimens, including KRAS-mutant, EGFR-altered, and ALK-rearranged adenocarcinomas. As a result, cooccurrence and interplay of apoptosis and pyroptosis were widespread in lung cancer cells, succumbing to genotype-matched regimens. We further demonstrated that pyroptotic cell death partially contributed to the drug response in a subset of cancer models. Conclusions: These results pinpoint GSDME-dependent pyroptosis as a previously unrecognized mechanism of action for molecular targeted agents to eradicate oncogene-addicted neoplastic cells, which may have important implications for the clinical development and optimal application of anticancer therapeutics.

Journal ArticleDOI
TL;DR: It is suggested that miR-27a alleviates LPS-induced ALI in mice via reducing inflammation and apoptosis through blocking TLR4/MyD88/NF-κB activation.
Abstract: Acute lung injury (ALI) is a critical clinical condition with a high mortality rate, characterized with excessive uncontrolled inflammation and apoptosis. Recently, microRNAs (miRNAs) have been found to play crucial roles in the amelioration of various inflammation-induced diseases, including ALI. However, it remains unknown the biological function and regulatory mechanisms of miRNAs in the regulation of inflammation and apoptosis in ALI. The aim of this study is to identify and evaluate the potential role of miRNAs in ALI and reveal the underlying molecular mechanisms of their effects. Here, we analyzed microRNA expression profiles in lung tissues from LPS-challenged mice using miRNA microarray. Because microRNA-27a (miR-27a) was one of the miRNAs being most significantly downregulated, which has an important role in regulation of inflammation, we investigated its function. Overexpression of miR-27a by agomir-27a improved lung injury, as evidenced by the reduced histopathological changes, lung wet/dry (W/D) ratio, lung microvascular permeability and apoptosis in the lung tissues, as well as ameliorative survival of ALI mice. This was accompanied by the alleviating of inflammation, such as the reduced total BALF cell and neutrophil counts, decreased levels of tumor necrosis factor alpha (TNF-α), interleukin-1 (IL-6) interleukin-1β (IL-1β) and myeloperoxidase (MPO) activity in BAL fluid. Toll-like receptor 4 (TLR4), an important regulator of the nuclear factor kappa-B (NF-κB) signaling pathway, was identified as a novel target of miR-27a in RAW264.7 cells. Furthermore, our results showed that LPS stimulation increased the expression of MyD88 and NF-κB p65 (p-p65), but inhibited the expression of inhibitor of nuclear factor-κB-α (IκB-α), suggesting the activation of NF-κB signaling pathway. Further investigations revealed that agomir-miR-27a reversed the promoting effect of LPS on NF-κB signaling pathway. The results here suggested that miR-27a alleviates LPS-induced ALI in mice via reducing inflammation and apoptosis through blocking TLR4/MyD88/NF-κB activation.

Journal ArticleDOI
TL;DR: Findings indicate that lncRNA cox‐2 inhibits HCC immune evasion and tumor growth by inhibiting the polarization of M2 macrophages.
Abstract: Objective: Macrophages have been shown to demonstrate a high level of plasticity, with the ability to undergo dynamic transition between M1 and M2 polarized phenotypes. We investigate long non-coding RNA (lncRNA) cox-2 in macrophage polarization and the regulatory mechanism functions in hepatocellular carcinoma (HCC). Methods: Lipopolysaccharide (LPS) was used to induce RAW264.7 macrophages into M1 type, and IL-4 was to induce RAW264.7 macrophages into M2 type. We selected mouse hepatic cell line Hepal-6 and hepatoma cell line HepG2 for co-incubation with M1 or M2 macrophages. Quantitative real-time PCR was used to detect the expressions of lncRNA cox-2and mRNAs. ELISA was conducted for testing IL-12 and IL-10 expressions; western blotting for epithelial mesenchymal transition related factors (E-cadherin and Vimentin). An MTT, colony formation assay, flow cytometry, transwell assay and stretch test were conducted to test cell abilities. Results: The M1 macrophages had higher lncRNA cox-2 expression than that in the non-polarized macrophages and M2 macrophages. The lncRNA cox-2 siRNA decreased the expression levels of IL-12, iNOS, and TNF-α in M1 macrophages, increased the expression levels of IL-10, Arg-1, and Fizz-1 in M2 macrophages (all P < 0.05). The lncRNA cox-2 siRNA reduces the ability of M1 macrophages to inhibit HCC cell proliferation, invasion, migration, EMT, angiogenesis and facilitate apoptosis while strengthening the ability of M2 macrophages to promote proliferation HCC cell growth and inhibit apoptosis. Conclusion: These findings indicate that lncRNA cox-2 inhibits HCC immune evasion and tumor growth by inhibiting the polarization of M2 macrophages. This article is protected by copyright. All rights reserved

Journal ArticleDOI
TL;DR: AS-IV reduced the growth, invasion, migration, and angiogenesis of lung cancer by blocking the M2 polarization of macrophages partially through the AMPK signaling pathway, which appears to play an important role in AS-IV’s ability to inhibit the metastasis of Lung cancer.
Abstract: Accumulating evidence suggests that M2-polarized tumor-associated macrophages (TAMs) play an important role in cancer progression and metastasis, making M2 polarization of TAMs an ever more appealing target for therapeutic intervention. Astragaloside IV (AS-IV), a saponin component isolated from Astragali radix, has been reported to inhibit the invasion and metastasis of lung cancer, but its effects on TAMs during lung cancer progression have not been investigated. Human THP-1 monocytes were induced to differentiate into M2 macrophages through treatments with IL-4, IL-13, and phorbol myristate acetate (PMA). We used the lung cancer cell lines A549 and H1299 cultured in conditioned medium from M2 macrophages (M2-CM) to investigate the effects of AS-IV on tumor growth, invasion, migration, and angiogenesis of lung cancer cells. Macrophage subset distribution, M1 and M2 macrophage-associated markers, and mRNA expression were analyzed by flow cytometry and quantitative PCR. The activation of adenosine monophosphate-activated protein kinase (AMPK) signaling pathways that mediate M2-CM–promoted tumor migration was detected using western blotting. Here we found that AS-IV significantly inhibited IL-13 and IL-4–induced M2 polarization of macrophages, as illustrated by reduced expression of CD206 and M2-associated genes, and that AS-IV suppressed the M2-CM–induced invasion, migration, and angiogenesis of A549 and H1299 cells. In vivo experiments demonstrated that AS-IV greatly inhibited tumor growth and reduced the number of metastases of Lewis lung cancer. The percentage of M2 macrophages was decreased in tumor tissue after AS-IV treatment. Furthermore, AS-IV inhibited AMPKα activation in M2 macrophages, and silencing of AMPKα partially abrogated the inhibitory effect of AS-IV. AS-IV reduced the growth, invasion, migration, and angiogenesis of lung cancer by blocking the M2 polarization of macrophages partially through the AMPK signaling pathway, which appears to play an important role in AS-IV’s ability to inhibit the metastasis of lung cancer.

Journal ArticleDOI
TL;DR: It is shown that persistent exposure to antigen in the absence of T cell help or ‘pathogen pattern motifs’ leads to B cell death via a calcium-dependent ‘metabolic timer’.
Abstract: B cells are activated by two temporally distinct signals, the first provided by the binding of antigen to the B cell antigen receptor (BCR), and the second provided by helper T cells. Here we found that B cells responded to antigen by rapidly increasing their metabolic activity, including both oxidative phosphorylation and glycolysis. In the absence of a second signal, B cells progressively lost mitochondrial function and glycolytic capacity, which led to apoptosis. Mitochondrial dysfunction was a result of the gradual accumulation of intracellular calcium through calcium response–activated calcium channels that, for approximately 9 h after the binding of B cell antigens, was preventable by either helper T cells or signaling via the receptor TLR9. Thus, BCR signaling seems to activate a metabolic program that imposes a limited time frame during which B cells either receive a second signal and survive or are eliminated. B cells need at least two signals to terminally differentiate into antibody-secreting cells. Pierce and colleagues show that persistent exposure to antigen in the absence of T cell help or ‘pathogen pattern motifs’ leads to B cell death via a calcium-dependent ‘metabolic timer’.

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TL;DR: The findings indicate that FT exhibits significant anti-cancer effects in MM that may be primarily mediated through the ROS-regulated inhibition of the STAT3 and STAT5 signaling cascade.

Journal ArticleDOI
TL;DR: It is demonstrated that Bax inhibitor 1 (BI1) functions as a novel microvascular guardian in cardiac IR injury that operates via inhibition of the Syk–Nox2–Drp1-mitochondrial fission signaling axis and could provide a survival advantage to microvasculature following IR stress.
Abstract: Mitochondrial fission has been identified as the pathogenesis underlying the development of cardiac microvascular ischemia reperfusion (IR) injury, although the regulatory signaling upstream from fission is far from clear. Bax inhibitor is a novel anti-apoptotic factor, and, however, its role of cardiac microvascular IR injury and mitochondrial homeostasis remains unclear. The cardiac microvascular IR injury was performed in WT mice and BI1 transgenic (BITG) mice. The alterations of microvascular structure and function were detected via electron microscope, immunohistochemistry and immunofluorescence in vivo. Cardiac microvascular endothelial cells were isolated form WT and BITG mice and underwent hypoxia/reoxygenation injury in vitro. Cellular viability and apoptosis were analyzed via MTT assay and caspase-3 activity. Mitochondrial function, morphology and apoptosis were detected. Signaling pathways were analyzed via inhibitor, siRNA and mutant plasmid. Herein, we demonstrated that Bax inhibitor 1 (BI1) was downregulated following cardiac microvascular IR injury, and its expression correlated negatively with microvascular collapse, endothelial cell apoptosis and mitochondrial damage. However, compared to wild-type mice, BI1 transgenic mice were actually protected from the acute microvascular injury and mitochondrial dysfunction. Functional studies illustrated that reintroduced BI1 directly interacted with and inhibited the Syk pathway, leading to the inactivation of Nox2. Subsequently, less Nox2 was associated with ROS downregulation, inhibiting Drp1 phosphorylated activation. Through repression of the Syk–Nox2–Drp1 signaling axis, BI1 strongly disrupted mitochondrial fission, abolishing mitochondrial apoptosis and thus sustaining endothelial cell viability. In summary, our report illustrates that BI1 functions as a novel microvascular guardian in cardiac IR injury that operates via inhibition of the Syk–Nox2–Drp1-mitochondrial fission signaling axis. Thus, novel therapeutic strategies to regulate the balance between BI1 and mitochondrial fission could provide a survival advantage to microvasculature following IR stress.

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TL;DR: The study revealed that Cd could impact the pancreas function and induce the activation of Bax and the overproduction of NO via PPAR-γ/PI3K/Akt pathway to promote apoptosis in chicken pancrea, however, Se could reduce Cd accumulation and antagonize Cd-triggered apoptosisIn chicken pancresas.

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TL;DR: Results suggest that the triple combined treatment with Piperlongumine, CN‑A and SSZ is highly effective against pancreatic cancer.
Abstract: Pancreatic cancer is one of the most lethal types of cancer with a mortality rate of almost 95%. Treatment with current chemotherapeutic drugs has limited success due to poor responses. Therefore, the development of novel drugs or effective combination therapies is urgently required. Piperlongumine (PL) is a natural product with cytotoxic properties restricted to cancer cells by significantly increasing intracellular reactive oxygen species (ROS) levels. In the present study, we demonstrated that PL induced cancer cell death through, at least in part, the induction of ferroptosis, as the cancer cell-killing activity was inhibited by the antioxidant, N‑acetylcysteine, ferroptosis inhibitors (ferrostatin‑1 and liproxstatin‑1) and the iron chelator, deferoxamine (DFO), but not by the apoptosis inhibitor, Z-VAD-FMK, or the necrosis inhibitor, necrostatin‑1. Cotylenin A (CN‑A; a plant growth regulator) exhibits potent antitumor activities in several cancer cell lines, including pancreatic cancer cell lines. We found that CN‑A and PL synergistically induced the death of pancreatic cancer MIAPaCa‑2 and PANC‑1 cells for 16 h. CN‑A enhanced the induction of ROS by PL for 4 h. The synergistic induction of cell death was also abrogated by the ferroptosis inhibitors and DFO. The present results revealed that clinically approved sulfasalazine (SSZ), a ferroptosis inducer, enhanced the death of pancreatic cancer cells induced by PL and the combined effects were abrogated by the ferroptosis inhibitors and DFO. SSZ further enhanced the cancer cell-killing activities induced by combined treatment with PL plus CN‑A. On the other hand, the synergistic induction of cell death by PL and CN‑A was not observed in mouse embryonic fibroblasts (MEFs), and SSZ did not enhance the death of MEFs induced by PL plus CN‑A. These results suggest that the triple combined treatment with PL, CN‑A and SSZ is highly effective against pancreatic cancer.

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TL;DR: Snail and Dlx-2, EMT-inducing transcription factors, are responsible for metabolic stress-induced necrosis in tumors and contribute to tumor progression by promoting necrosis and inducing EMT and oncogenic metabolism.
Abstract: Rapidly growing malignant tumors frequently encounter hypoxia and nutrient (e.g., glucose) deprivation, which occurs because of insufficient blood supply. This results in necrotic cell death in the core region of solid tumors. Necrotic cells release their cellular cytoplasmic contents into the extracellular space, such as high mobility group box 1 (HMGB1), which is a nonhistone nuclear protein, but acts as a proinflammatory and tumor-promoting cytokine when released by necrotic cells. These released molecules recruit immune and inflammatory cells, which exert tumor-promoting activity by inducing angiogenesis, proliferation, and invasion. Development of a necrotic core in cancer patients is also associated with poor prognosis. Conventionally, necrosis has been thought of as an unregulated process, unlike programmed cell death processes like apoptosis and autophagy. Recently, necrosis has been recognized as a programmed cell death, encompassing processes such as oncosis, necroptosis, and others. Metabolic stress-induced necrosis and its regulatory mechanisms have been poorly investigated until recently. Snail and Dlx-2, EMT-inducing transcription factors, are responsible for metabolic stress-induced necrosis in tumors. Snail and Dlx-2 contribute to tumor progression by promoting necrosis and inducing EMT and oncogenic metabolism. Oncogenic metabolism has been shown to play a role(s) in initiating necrosis. Here, we discuss the molecular mechanisms underlying metabolic stress-induced programmed necrosis that promote tumor progression and aggressiveness.