Infrasound sensitizes human glioblastoma cells to cisplatin-induced apoptosis.

PubMed

Rachlin, Kenneth; Moore, Dan H; Yount, Garret

2013-11-01

The development of nontoxic agents that can selectively enhance the cytotoxicity of chemotherapy is an important aim in oncology. This study evaluates the ability of infrasound exposure to sensitize glioblastoma cells to cisplatin-induced apoptosis. The infrasound was delivered using a device designed to replicate the unique infrasound emissions measured during external Qigong treatments. Human glioblastoma cell lines harboring wild-type p53 (U87) or mutant p53 (U251, SF210, and SF188) were treated in culture with cisplatin, infrasound emissions, or the combination of the 2 agents. Induction of apoptosis was quantified after 24 hours by flow cytometry following annexin V/propidium iodide staining. Infrasound emissions alone, delivered at moderate levels (~10 mPa) with dynamic frequency content (7-13 Hz), did not induce apoptosis, yet combining infrasound with cisplatin augmented the induction of apoptosis by cisplatin in all the 4 cell lines (P < .05). Increased cellular uptake of the fluorophore calcein associated with infrasound exposure was quantified by fluorescence microscopy as well as flow cytometry, demonstrating increased cell membrane permeability. The 4 cell lines differed in the degree to which infrasound exposure increased calcein uptake, and these differences were predictive of the extent to which infrasound enhanced cisplatin-induced apoptosis. When exposed to specific frequencies, membrane permeabilization also appeared to be differentially responsive for each cell line, suggesting the potential for selective targeting of tissue types using isolated infrasonic frequencies. Additionally, the pressure amplitudes used in this study were several orders of magnitude less than those used in similar studies involving ultrasound and shock waves. The results of this study provide support for using infrasound to enhance the chemotherapeutic effects of cisplatin in a clinical setting.

Apoptosis-inducing factor (Aif1) mediates anacardic acid-induced apoptosis in Saccharomyces cerevisiae.

PubMed

Muzaffar, Suhail; Chattoo, Bharat B

2017-03-01

Anacardic acid is a medicinal phytochemical that inhibits proliferation of fungal as well as several types of cancer cells. It induces apoptotic cell death in various cell types, but very little is known about the mechanism involved in the process. Here, we used budding yeast Saccharomyces cerevisiae as a model to study the involvement of some key elements of apoptosis in the anacardic acid-induced cell death. Plasma membrane constriction, chromatin condensation, DNA degradation, and externalization of phosphatidylserine (PS) indicated that anacardic acid induces apoptotic cell death in S. cerevisiae. However, the exogenous addition of broad-spectrum caspase inhibitor Z-VAD-FMK or deletion of the yeast caspase Yca1 showed that the anacardic acid-induced cell death is caspase independent. Apoptosis-inducing factor (AIF1) deletion mutant was resistant to the anacardic acid-induced cell death, suggesting a key role of Aif1. Overexpression of Aif1 made cells highly susceptible to anacardic acid, further confirming that Aif1 mediates anacardic acid-induced apoptosis. Interestingly, instead of the increase in the intracellular reactive oxygen species (ROS) normally observed during apoptosis, anacardic acid caused a decrease in the intracellular ROS levels. Quantitative real-time PCR analysis showed downregulation of the BIR1 survivin mRNA expression during the anacardic acid-induced apoptosis.

The Fanconi anemia pathway sensitizes to DNA alkylating agents by inducing JNK-p53-dependent mitochondrial apoptosis in breast cancer cells.

PubMed

Zhao, Lin; Li, Yanlin; He, Miao; Song, Zhiguo; Lin, Shu; Yu, Zhaojin; Bai, Xuefeng; Wang, Enhua; Wei, Minjie

2014-07-01

The Fanconi anemia/BRCA (FA/BRCA) DNA damage repair pathway plays a pivotal role in the cellular response to DNA alkylating agents and greatly influences drug response in cancer treatment. However, the molecular mechanisms underlying the FA/BRCA pathway reversed resistance have received limited attention. In the present study, we investigated the effect of Fanconi anemia complementation group F protein (FANCF), a critical factor of the FA/BRCA pathway, on cancer cell apoptosis induced by DNA alkylating agents such as mitomycin c (MMC). We found that FANCF shRNA potentiated MMC-induced cytotoxicity and apoptosis in MCF-7 and MDA-MB-231 breast cancer cells. At a mechanistic level, FANCF shRNA downregulated the anti-apoptotic protein Bcl-2 and upregulated the pro-apoptotic protein Bax, accompanied by release of cyt-c and smac into the cytosol in MMC-treated cells. Furthermore, activation of caspase-3 and -9, other than caspase-8, cleavage of poly(ADP ribose) polymerase (PARP), and a decrease of mitochondrial membrane potential (MMP) indicated that involvement of the mitochondrial apoptotic pathway in FANCF silencing of MMC-treated breast cancer cells. A decrease in IAP family proteins XIAP and survivin were also observed following FANCF silencing in MMC-treated breast cancer cells. Notably, FANCF shRNA was able to increase p53 levels through activation of the JNK pathway in MMC-treated breast cancer cells. Furthermore, p53 inhibition using pifithrin-α abolished the induction of caspase-3 and PARP by FANCF shRNA and MMC, indicating that MMC-induced apoptosis is substantially enhanced by FANCF shRNA via p53-dependent mechanisms. To our knowledge, we provide new evidence for the potential application of FANCF as a chemosensitizer in breast cancer therapy.

Inducing death in tumor cells: roles of the inhibitor of apoptosis proteins.

PubMed

Finlay, Darren; Teriete, Peter; Vamos, Mitchell; Cosford, Nicholas D P; Vuori, Kristiina

2017-01-01

The heterogeneous group of diseases collectively termed cancer results not just from aberrant cellular proliferation but also from a lack of accompanying homeostatic cell death. Indeed, cancer cells regularly acquire resistance to programmed cell death, or apoptosis, which not only supports cancer progression but also leads to resistance to therapeutic agents. Thus, various approaches have been undertaken in order to induce apoptosis in tumor cells for therapeutic purposes. Here, we will focus our discussion on agents that directly affect the apoptotic machinery itself rather than on drugs that induce apoptosis in tumor cells indirectly, such as by DNA damage or kinase dependency inhibition. As the roles of the Bcl-2 family have been extensively studied and reviewed recently, we will focus in this review specifically on the inhibitor of apoptosis protein (IAP) family. IAPs are a disparate group of proteins that all contain a baculovirus IAP repeat domain, which is important for the inhibition of apoptosis in some, but not all, family members. We describe each of the family members with respect to their structural and functional similarities and differences and their respective roles in cancer. Finally, we also review the current state of IAPs as targets for anti-cancer therapeutics and discuss the current clinical state of IAP antagonists.

Endocannabinoids participate in placental apoptosis induced by hypoxia inducible factor-1.

PubMed

Abán, C; Martinez, N; Carou, C; Albamonte, I; Toro, A; Seyahian, A; Franchi, A; Leguizamón, G; Trigubo, D; Damiano, A; Farina, M

2016-10-01

During pregnancy, apoptosis is a physiological event critical in the remodeling and aging of the placenta. Increasing evidence has pointed towards the relevance of endocannabinoids (ECs) and hypoxia as modulators of trophoblast cell death. However, the relation between these factors is still unknown. In this report, we evaluated the participation of ECs in placental apoptosis induced by cobalt chloride (CoCl2), a hypoxia mimicking agent that stabilizes the expression of hypoxia inducible factor-1 alpha (HIF-1α). We found that HIF-1α stabilization decreased FAAH mRNA and protein levels, suggesting an increase in ECs tone. Additionally, CoCl2 incubation and Met-AEA treatment reduced cell viability and increased TUNEL-positive staining in syncytiotrophoblast layer. Immunohistochemical analysis demonstrated Bax and Bcl-2 protein expression in the cytoplasm of syncytiotrophoblast. Finally, HIF-1α stabilization produced an increase in Bax/Bcl-2 ratio, activation of caspase 3 and PARP cleavage. All these changes in apoptotic parameters were reversed with AM251, a CB1 antagonist. These results demonstrate that HIF-1α may induce apoptosis in human placenta via intrinsic pathway by a mechanism that involves activation of CB1 receptor suggesting a role of the ECs in this process.

Apoptosis of vascular smooth muscle cells induces features of plaque vulnerability in atherosclerosis.

PubMed

Clarke, Murray C H; Figg, Nichola; Maguire, Janet J; Davenport, Anthony P; Goddard, Martin; Littlewood, Trevor D; Bennett, Martin R

2006-09-01

Vascular smooth muscle cell (VSMC) apoptosis occurs in many arterial diseases, including aneurysm formation, angioplasty restenosis and atherosclerosis. Although VSMC apoptosis promotes vessel remodeling, coagulation and inflammation, its precise contribution to these diseases is unknown, given that apoptosis frequently accompanies vessel injury or alterations to flow. To study the direct consequences of VSMC apoptosis, we generated transgenic mice expressing the human diphtheria toxin receptor (hDTR, encoded by HBEGF) from a minimal Tagln (also known as SM22alpha) promoter. Despite apoptosis inducing loss of 50-70% of VSMCs, normal arteries showed no inflammation, reactive proliferation, thrombosis, remodeling or aneurysm formation. In contrast, VSMC apoptosis in atherosclerotic plaques of SM22alpha-hDTR Apoe-/- mice induced marked thinning of fibrous cap, loss of collagen and matrix, accumulation of cell debris and intense intimal inflammation. We conclude that VSMC apoptosis is 'silent' in normal arteries, which have a large capacity to withstand cell loss. In contrast, VSMC apoptosis alone is sufficient to induce features of plaque vulnerability in atherosclerosis. SM22alpha-hDTR Apoe-/- mice may represent an important new model to test agents proposed to stabilize atherosclerotic plaques.

Apoptosis by dietary agents for prevention and treatment of prostate cancer

PubMed Central

Khan, Naghma; Adhami, Vaqar Mustafa; Mukhtar, Hasan

2010-01-01

Accumulating data clearly indicate that induction of apoptosis is an important event for chemoprevention of cancer by naturally occurring dietary agents. In mammalian cells, apoptosis has been divided into two major pathways: the extrinsic pathway, activated by pro-apoptotic receptor signals at the cellular surface; and the intrinsic pathway, which involves the disruption of mitochondrial membrane integrity. This process is strictly controlled in response to integrity of pro-death signaling and plays critical roles in development, maintenance of homeostasis, and host defense in multicellular organisms. For chemoprevention studies, prostate cancer (PCa) represents an ideal disease due to its long latency, its high incidence, tumor marker availability, and identifiable preneoplastic lesions and risk groups. In this article, we highlight the studies of various apoptosis-inducing dietary compounds for prevention of PCa in vitro in cell culture, in preclinical studies in animals, and in human clinical trials. PMID:19926708

Activation of the proapoptotic Bcl-2 protein Bax by a small molecule induces tumor cell apoptosis.

PubMed

Zhao, Guoping; Zhu, Yanglong; Eno, Colins O; Liu, Yanlong; Deleeuw, Lynn; Burlison, Joseph A; Chaires, Jonathan B; Trent, John O; Li, Chi

2014-04-01

The proapoptotic Bcl-2 protein Bax by itself is sufficient to initiate apoptosis in almost all apoptotic paradigms. Thus, compounds that can facilitate disruptive Bax insertion into mitochondrial membranes have potential as cancer therapeutics. In our study, we have identified small-molecule compounds predicted to associate with the Bax hydrophobic groove by a virtual-screen approach. Among these, one lead compound (compound 106) promotes Bax-dependent but not Bak-dependent apoptosis. Importantly, this compound alters Bax protein stability in vitro and promotes the insertion of Bax into mitochondria, leading to Bax-dependent permeabilization of the mitochondrial outer membrane. Furthermore, as a single agent, compound 106 inhibits the growth of transplanted tumors, probably by inducing apoptosis in tumors. Our study has revealed a compound that activates Bax and induces Bax-dependent apoptosis, which may lead to the development of new therapeutic agents for cancer.

Novel microtubule-targeted agent 6-chloro-4-(methoxyphenyl) coumarin induces G2-M arrest and apoptosis in HeLa cells

PubMed Central

Ma, Yi-ming; Zhou, Yu-bo; Xie, Chuan-ming; Chen, Dong-mei; Li, Jia

2012-01-01

Aim: To identify a novel coumarin analogue with the highest anticancer activity and to further investigate its anticancer mechanisms. Methods: The viability of cancer cells was investigated using the MTT assay. The cell cycle progression was evaluated using both flow cytometric and Western blotting analysis. Microtubule depolymerization was observed with immunocytochemistry in vivo and a tubulin depolymerization assay in vitro. Apoptosis was demonstrated using Annexin V/Propidium Iodide (PI) double-staining and sub-G1 analysis. Results: Among 36 analogues of coumarin, 6-chloro-4-(methoxyphenyl) coumarin showed the best anticancer activity (IC50 value about 200 nmol/L) in HCT116 cells. The compound had a broad spectrum of anticancer activity against 9 cancer cell lines derived from colon cancer, breast cancer, liver cancer, cervical cancer, leukemia, epidermoid cancer with IC50 value of 75 nmol/L–1.57 μmol/L but with low cytotocitity against WI-38 human lung fibroblasts (IC50 value of 12.128 μmol/L). The compound (0.04–10 μmol/L) induced G2-M phase arrest in HeLa cells in a dose-dependent manner, which was reversible after the compound was removed. The compound (10–300 μmol/L) induced the depolymerization of purified porcine tubulin in vitro. Finally, the compound (0.04–2.5 μmol/L) induced apoptosis of HeLa cells in dose- and time-dependent manners. Conclusion: 6-Chloro-4-(methoxyphenyl) coumarin is a novel microtubule-targeting agent that induces G2–M arrest and apoptosis in HeLa cells. PMID:22266726

Equine Airway Mast Cells are Sensitive to Cell Death Induced by Lysosomotropic Agents.

PubMed

Wernersson, S; Riihimäki, M; Pejler, G; Waern, I

2017-01-01

Mast cells are known for their detrimental effects in various inflammatory conditions. Regimens that induce selective mast cell apoptosis may therefore be of therapeutic significance. Earlier studies have demonstrated that murine- and human-cultured mast cells are highly sensitive to apoptosis induced by the lysosomotropic agent LeuLeuOMe (LLME). However, the efficacy of lysosomotropic agents for inducing apoptosis of in vivo-derived airway mast cells and the impact on mast cells in other species have not been assessed. Here we addressed whether lysosomotropic agents can induce cell death of equine in vivo-derived mast cells. Bronchoalveolar lavage (BAL) fluids from horses were incubated with LLME at 15-100 μm for up to 48 h. The overall cell viability was unaffected by 15 μm LLME up to 48 h, whereas a relatively modest drop in total cell counts (~30%) was seen at the highest LLME dose used. In contrast to the relatively low effect on total cell counts, LLME efficiently and dose dependently reduced the number of mast cells in BAL fluids, with an almost complete depletion (96%) of mast cells after 24 h of incubation with 100 μm LLME. A significant but less dramatic reduction (up to ~45%) of lymphocytes was also seen, whereas macrophages and neutrophils were essentially resistant. The appearance of apoptotic bodies suggested a mechanism involving apoptosis rather than necrosis. These findings suggest that equine airway mast cells are highly sensitive to lysosomotropic agents. Possibly, lysosomotropic agents could be of therapeutic value to treat disorders involving harmful accumulation of mast cells in the airways. © 2016 The Foundation for the Scandinavian Journal of Immunology.

Pathway-specific effect of caffeine on protection against UV irradiation-induced apoptosis in corneal epithelial cells.

PubMed

Wang, Ling; Lu, Luo

2007-02-01

To define the role of molecular interaction between the UV-induced JNK (c-Jun N-terminal kinase) cascade and corneal epithelial cell apoptosis and protection against apoptosis by caffeine. Rabbit and human corneal epithelial cells were cultured in DMEM/F12 medium containing 10% FBS and 5 microg/mL insulin at 37 degrees C in 5% CO(2). DNA fragmentation and ethidium bromide/acridine orange (EB/AO) nuclear staining were performed to detect cell death. Western blot, immunoprecipitation, and kinase assays were used to measure UV-induced mitogen-activated protein (MAP) kinase activity. UV irradiation-induced apoptosis through apoptosis signal-regulating kinase 1 (ASK1) and MAKK4 (SEK1) upstream from JNK was caffeine sensitive. Caffeine (1,3,7-trimethylxanthine), an agent that is one of the most popular additions to food consumed in the world and a potential enhancer of chemotherapy, effectively protected corneal epithelial cells against apoptosis by its specific effect on the JNK cascade. Theophylline (1,3-dimethylxanthine) exhibited an effect similar to that of caffeine on prevention of UV irradiation-induced apoptosis. However, alterations of either intracellular cAMP or Ca(2+) levels did not alter the effect of caffeine on the JNK signaling pathway. In addition, the blockade of PI3K-like kinases by wortmannin had no impact on the protective effect of caffeine against UV irradiation-induced apoptosis, suggesting that the protective effect of caffeine acts through a specific mechanism involving UV irradiation-induced activation of ASK1 and SEK1. In contrast, caffeine had no effects on melphalan-, hyperosmotic stress-, or IL-1beta-induced activation of the JNK signaling pathway in these cells. UV irradiation stress-induced activation of the ASK1-SEK1-JNK signaling pathway leading to apoptosis is a caffeine-sensitive process, and caffeine, as a multifunctional agent in cells, can specifically interact with the pathway to protect against apoptosis.

Administration of the antitumor drug mitoguazone protects normal thymocytes against spontaneous and etoposide-induced apoptosis.

PubMed

Ferioli, M E; Bottone, M G; Soldani, C; Pellicciari, C

2004-11-01

The suggestion has been made that polyamines may be involved in the control of cell death, since exceedingly high or low levels induce apoptosis in different cell systems. For a deeper insight into the relationship between apoptosis and polyamine metabolism, we investigated in vitro the effect on rat thymocytes of mitoguazone (MGBG, which inhibits S-adenosylmethionine decarboxylase, i.e. a key enzyme in the polyamine biosynthetic pathway). Thymocytes were selected as an especially suitable model system, since they undergo spontaneous apoptosis in vivo and can be easily induced to apoptose in vitro by etoposide, used here as an apoptogenic agent. MGBG protected thymocytes from both spontaneous and drug-induced apoptosis, and this protective effect was associated with a decrease in polyamine oxidase activity and total polyamine levels.

Silibinin stimluates apoptosis by inducing generation of ROS and ER stress in human choriocarcinoma cells.

PubMed

Ham, Jiyeon; Lim, Whasun; Bazer, Fuller W; Song, Gwonhwa

2018-02-01

Silibinin is a flavonolignan extracted from seeds of milk thistles. Traditionally, it has been used as a therapeutic agent for liver disorders, and now it is well-known for its anti-cancer effects. However, studies on anti-cancer effects of silibinin on choriocarcinoma are very limited. Therefore, we performed proliferation and apoptosis assays to determine effects of silibinin on the viability of human choriocarcinoma (JAR and JEG3) cells. Our results showed that silibinin significantly inhibited proliferation and induced apoptosis in both JAR and JEG3 cells, and significantly increased reactive oxygen species (ROS) and lipid peroxidation. Moreover, silibinin disrupted mitochondrial function by inducing permeabilization of mitochondrial membrane potential and calcium ion efflux in JAR and JEG3 cells. Furthermore, silibinin-induced apoptosis in choriocarcinoma cells via AKT, mitogen-activated protein kinases (MAPK) and unfolded protein response (UPR) signal transduction. Collectively, our results suggest that silibinin is a novel therapeutic agent or dietary supplement for management of human placental choriocarcinomas. © 2017 Wiley Periodicals, Inc.

Centchroman induces redox-dependent apoptosis and cell-cycle arrest in human endometrial cancer cells.

PubMed

Shyam, Hari; Singh, Neetu; Kaushik, Shweta; Sharma, Ramesh; Balapure, Anil K

2017-04-01

Centchroman (CC) or Ormeloxifene has been shown to induce apoptosis and cell cycle arrest in various types of cancer cells. This has, however, not been addressed for endometrial cancer cells where its (CC) mechanism of action remains unclear. This study focuses on the basis of antineoplasticity of CC by blocking the targets involved in the cell cycle, survival and apoptosis in endometrial cancer cells. Ishikawa Human Endometrial Cancer Cells were cultured under estrogen deprived medium, exposed to CC and analyzed for proliferation and apoptosis. Additionally, we also analyzed oxidative stress induced by CC. Cell viability studies confirmed the IC 50 of CC in Ishikawa cells to be 20 µM after 48 h treatment. CC arrests the cells in G0/G1 phase through cyclin D1 and cyclin E mediated pathways. Phosphatidylserine externalization, nuclear morphology changes, DNA fragmentation, PARP cleavage, and alteration of Bcl-2 family protein expression clearly suggest ongoing apoptosis in the CC treated cells. Activation of caspase 3 & 9, up-regulation of AIF and inhibition of apoptosis by z-VAD-fmk clearly explains the participation of the intrinsic pathway of programmed cell death. Further, the increase of ROS, loss of MMP, inhibition of antioxidant (MnSOD, Cu/Zn-SOD and GST) and inhibition of apoptosis with L-NAC suggests CC induced oxidative stress leading to apoptosis via mitochondria mediated pathway. Therefore, CC could be a potential therapeutic agent for the treatment of Endometrial Cancer adjunct to its utility as a contraceptive and an anti-breast cancer agent.

Activation of the Proapoptotic Bcl-2 Protein Bax by a Small Molecule Induces Tumor Cell Apoptosis

PubMed Central

Zhao, Guoping; Zhu, Yanglong; Eno, Colins O.; Liu, Yanlong; DeLeeuw, Lynn; Burlison, Joseph A.; Chaires, Jonathan B.; Trent, John O.

2014-01-01

The proapoptotic Bcl-2 protein Bax by itself is sufficient to initiate apoptosis in almost all apoptotic paradigms. Thus, compounds that can facilitate disruptive Bax insertion into mitochondrial membranes have potential as cancer therapeutics. In our study, we have identified small-molecule compounds predicted to associate with the Bax hydrophobic groove by a virtual-screen approach. Among these, one lead compound (compound 106) promotes Bax-dependent but not Bak-dependent apoptosis. Importantly, this compound alters Bax protein stability in vitro and promotes the insertion of Bax into mitochondria, leading to Bax-dependent permeabilization of the mitochondrial outer membrane. Furthermore, as a single agent, compound 106 inhibits the growth of transplanted tumors, probably by inducing apoptosis in tumors. Our study has revealed a compound that activates Bax and induces Bax-dependent apoptosis, which may lead to the development of new therapeutic agents for cancer. PMID:24421393

Curcumin induces Apaf-1-dependent, p21-mediated caspase activation and apoptosis

PubMed Central

Zhang, Honghao; Jones, Anthony; Verone, Alissa; Pitarresi, Jason; Jandhyam, Sirisha; Prabhu, Varun; Black, Jennifer D

2011-01-01

Previous studies have demonstrated that curcumin induces mitochondria-mediated apoptosis. However, understanding of the molecular mechanisms underlying curcumin-induced cell death remains limited. In this study, we demonstrate that curcumin treatment of cancer cells caused dose- and time-dependent caspase 3 activation, which is required for apoptosis as confirmed using the pan-caspase inhibitor, z-VAD. Knockdown experiments and knockout cells excluded a role for caspase 8 in curcumin-induced caspase 3 activation. In contrast, Apaf-1 deficiency or silencing inhibited the activity of caspase 3, pointing to a requisite role of Apaf-1 in curcumin-induced apoptotic cell death. Curcumin treatment led to Apaf-1 upregulation, both at the protein and mRNA levels. Cytochrome c release from mitochondria to the cytosol in curcumin-treated cells was associated with upregulation of pro-apoptotic proteins, such as Bax, Bak, Bid and Bim. Cross-linking experiments demonstrated Bax oligomerization during curcumin-induced apoptosis, suggesting that induced expression of Bax, Bid and Bim causes Bax channel formation on the mitochondrial membrane. The release of cytochrome c was unaltered in p53-deficient cells, whereas absence of p21 blocked cytochrome c release, caspase activation and apoptosis. Importantly, p21 deficiency resulted in reduced expression of Apaf-1 during curcumin treatment, indicating a requirement for p21 in Apaf-1-dependent caspase activation and apoptosis. Together, our findings identify Apaf-1, Bax and p21 as novel potential targets for curcumin or curcumin-based anticancer agents. PMID:22101335

The aryl hydrocarbon receptor (AhR) mediates resistance to apoptosis induced in breast cancer cells.

PubMed

Bekki, Kanae; Vogel, Helena; Li, Wen; Ito, Tomohiro; Sweeney, Colleen; Haarmann-Stemmann, Thomas; Matsumura, Fumio; Vogel, Christoph F A

2015-05-01

The aryl hydrocarbon receptor (AhR) is well known as a ligand binding transcription factor regulating various biological effects. Previously we have shown that long-term exposure to estrogen in breast cancer cells caused not only down regulation of estrogen receptor (ER) but also overexpression of AhR. The AhR interacts with several cell signaling pathways associated with induction of tyrosine kinases, cytokines and growth factors which may support the survival roles of AhR escaping from apoptosis elicited by a variety of apoptosis inducing agents in breast cancer. In this study, we studied the anti-apoptotic role of AhR in different breast cancer cells when apoptosis was induced by exposure to UV light and chemotherapeutic agents. Activation of AhR by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in AhR overexpressing breast cancer cells effectively suppressed the apoptotic response induced by UV-irradiation, doxorubicin, lapatinib and paclitaxel. The anti-apoptotic response of TCDD was uniformly antagonized by the treatment with 3'methoxy-4'nitroflavone (MNF), a specific antagonist of AhR. TCDD's survival action of apoptosis was accompanied with the induction of well-known inflammatory genes, such as cyclooxygenase-2 (COX-2) and NF-κB subunit RelB. Moreover, TCDD increased the activity of the immunosuppressive enzyme indoleamine 2, 3-dioxygenase (IDO), which metabolizes tryptophan to kynurenine (Kyn) and mediates tumor immunity. Kyn also acts as an AhR ligand like TCDD, and kyn induced an anti-apoptotic response in breast cancer cells. Accordingly, our present study suggests that AhR plays a pivotal role in the development of breast cancer via the suppression of apoptosis, and provides an idea that the use of AhR antagonists with chemotherapeutic agents may effectively synergize the elimination of breast cancer cells. Copyright © 2014 Elsevier Inc. All rights reserved.

Downregulation of X-linked inhibitor of apoptosis protein by '7-Benzylidenenaltrexone maleate' sensitizes pancreatic cancer cells to TRAIL-induced apoptosis.

PubMed

Kim, So Young; Park, Sojung; Yoo, SeonA; Rho, Jin Kyung; Jun, Eun Sung; Chang, Suhwan; Kim, Kyung Kon; Kim, Song Cheol; Kim, Inki

2017-09-22

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a potential biological anticancer agent. However, a wide range of human primary cancers, including pancreatic cancer, display resistance to apoptosis induction by TRAIL. Therefore, this resistance needs to be overcome to allow TRAIL to be successfully used in cancer therapy. In this study, we performed a compound screen to isolate TRAIL sensitizers and found that one of the identified compounds, 7-benzylidenenaltrexone maleate (BNTX), sensitized pancreatic cancer cells to TRAIL-induced apoptotic cell death. The combination of BNTX with TRAIL promoted the release of cytochrome c from mitochondria into cytosol with caspase activation and a resulting increase in annexin V-stained cells. From a mechanistic perspective, we found that BNTX downregulated X-linked inhibitor of apoptosis protein (XIAP) expression when used in combination with TRAIL, and found that TRAIL-induced apoptosis was augmented by siRNA-mediated knockdown of XIAP. We further demonstrated that BNTX promoted the ubiquitin/proteasome-dependent degradation of XIAP protein via protein kinase C (PKC) alpha/AKT pathway inhibition. Moreover, combined treatment by BNTX with TRAIL suppressed growth of pancreatic tumor xenograft of animal model. Therefore, we suggest that inhibitor of apoptosis protein-mediated resistance of pancreatic cancer cells to anticancer therapeutics can be overcome by inhibiting the PKCα/AKT pathway.

Lovastatin induces apoptosis of ovarian cancer cells and synergizes with doxorubicin: potential therapeutic relevance.

PubMed

Martirosyan, Anna; Clendening, James W; Goard, Carolyn A; Penn, Linda Z

2010-03-18

Ovarian carcinoma is a rarely curable disease, for which new treatment options are required. As agents that block HMG-CoA reductase and the mevalonate pathway, the statin family of drugs are used in the treatment of hypercholesterolemia and have been shown to trigger apoptosis in a tumor-specific manner. Recent clinical trials show that the addition of statins to traditional chemotherapeutic strategies can increase efficacy of targeting statin-sensitive tumors. Our goal was to assess statin-induced apoptosis of ovarian cancer cells, either alone or in combination with chemotherapeutics, and then determine these mechanisms of action. The effect of lovastatin on ovarian cancer cell lines was evaluated alone and in combination with cisplatin and doxorubicin using several assays (MTT, TUNEL, fixed PI, PARP cleavage) and synergy determined by evaluating the combination index. The mechanisms of action were evaluated using functional, molecular, and pharmacologic approaches. We demonstrate that lovastatin induces apoptosis of ovarian cancer cells in a p53-independent manner and synergizes with doxorubicin, a chemotherapeutic agent used to treat recurrent cases of ovarian cancer. Lovastatin drives ovarian tumor cell death by two mechanisms: first, by blocking HMG-CoA reductase activity, and second, by sensitizing multi-drug resistant cells to doxorubicin by a novel mevalonate-independent mechanism. This inhibition of drug transport, likely through inhibition of P-glycoprotein, potentiates both DNA damage and tumor cell apoptosis. The results of this research provide pre-clinical data to warrant further evaluation of statins as potential anti-cancer agents to treat ovarian carcinoma. Many statins are inexpensive, off-patent generic drugs that are immediately available for use as anti-cancer agents. We provide evidence that lovastatin triggers apoptosis of ovarian cancer cells as a single agent by a mevalonate-dependent mechanism. Moreover, we also show lovastatin synergizes

Elevation of cAMP Levels Inhibits Doxorubicin-Induced Apoptosis in Pre- B ALL NALM- 6 Cells Through Induction of BAD Phosphorylation and Inhibition of P53 Accumulation.

PubMed

Fatemi, Ahmad; Kazemi, Ahmad; Kashiri, Meysam; Safa, Majid

2015-01-01

Recognition of the molecular mechanisms of cAMP action against DNA damage-induced apoptosis can be useful to improve the efficacy of DNA damaging therapeutic agents. Considering the critical role of bcl-2-associated death promoter (BAD) and p53 proteins in DNA damage -induced apoptosis, the aim of this study was to assess the effect of cAMP-elevating agents on these proteins in doxorubicin-treated pre-B acute lymphoblastic leukemia (pre-B ALL) NALM-6 cells.The pre-B ALL cell line NALM-6 was cultured and treated with doxorubicin in combination with or without cAMP-elevating agents forskolin and 3-isobutyl-1-methylxanthine (IBMX). Cell viability was measured by trypan blue staining and MTT assay. For evaluation of apoptosis, annexin-V staining by flow cytometry and caspase-3 activity assay were used. Protein expression of p53, BAD and phoshorylated BAD was detected by western blotting analysis.cAMP-increasing agents diminished the doxorubicin-mediated cytotoxicity in NALM-6 cells as indicated by the viability assays. Annexin-V apoptosis assay showed that the cAMP-elevating agents decreased doxorubicin-induced apoptosis. Moreover, doxorubicin-induced caspase-3 activity was attenuated in the presence of cAMP-increasing agents. Western blot results revealed the reduced expression of p53 protein in cells treated with combination of cAMP-elevating agents and doxorubicin in contrast to cells treated with doxorubicin alone. Expression of total BAD protein was not affected by doxorubicin and cAMP-elevating agents. However, phosphorylation of BAD protein was induced in the presence of cAMP-elevating agents. Our study suggests that elevated cAMP levels inhibit doxorubicin-induced apoptosis in pre-B ALL cells through induction of BAD phosphorylation and abrogation of p53 accumulation.

Design, synthesis and biological evaluation of hybrids of β-carboline and salicylic acid as potential anticancer and apoptosis inducing agents

PubMed Central

Xu, Qi-Bing; Chen, Xiang-Fan; Feng, Jiao; Miao, Jie-Fei; Liu, Ji; Liu, Feng-Tao; Niu, Bi-Xi; Cai, Jin-Yang; Huang, Chao; Zhang, Yanan; Ling, Yong

2016-01-01

A novel series of hybrids (7a-l, 8a-l) from β-carboline and salicylic acid (SA) were designed and synthesized, and their in vitro biological activities were evaluated. Most of the hybrids displayed potent antiproliferative activity against five cancer cell lines in vitro, showing potencies superior to 5-FU and harmine. In particular, compound 8h selectively inhibited proliferation of liver cancer SMMC-7721 cells but not normal liver LO2 cells, and displayed greater inhibitory selectivity than intermediate 5h and SA. 8h also induced cancer cell apoptosis in an Annexin V-FITC/propidium iodide flow cytometry assay, and triggered the mitochondrial/caspase apoptosis by decreasing mitochondrial membrane potential which was associated with up-regulation of Bax, down-regulation of Bcl-2 and activation levels of the caspase cascade in a concentration-dependent manner. Our findings suggest that the β-carboline/SA hybrids may hold greater promise as therapeutic agents for the intervention of human cancers. PMID:27824091

Bozepinib, a novel small antitumor agent, induces PKR-mediated apoptosis and synergizes with IFNα triggering apoptosis, autophagy and senescence

PubMed Central

Marchal, Juan Antonio; Carrasco, Esther; Ramirez, Alberto; Jiménez, Gema; Olmedo, Carmen; Peran, Macarena; Agil, Ahmad; Conejo-García, Ana; Cruz-López, Olga; Campos, Joaquin María; García, María Ángel

2013-01-01

Bozepinib [(RS)-2,6-dichloro-9-[1-(p-nitrobenzenesulfonyl)-1,2,3,5-tetrahydro-4,1-benzoxazepin-3-yl]-9H-purine] is a potent antitumor compound that is able to induce apoptosis in breast cancer cells. In the present study, we show that bozepinib also has antitumor activity in colon cancer cells, showing 50% inhibitory concentration (IC50) values lower than those described for breast cancer cells and suggesting great potential of this synthetic drug in the treatment of cancer. We identified that the double-stranded RNA-dependent protein kinase (PKR) is a target of bozepinib, being upregulated and activated by the drug. However, p53 was not affected by bozepinib, and was not necessary for induction of apoptosis in either breast or colon cancer cells. In addition, the efficacy of bozepinib was improved when combined with the interferon-alpha (IFNα) cytokine, which enhanced bozepinib-induced apoptosis with involvement of protein kinase PKR. Moreover, we report here, for the first time, that in combined therapy, IFNα induces a clear process of autophagosome formation, and prior treatment with chloroquine, an autophagy inhibitor, is able to significantly reduce IFNα/bozepinib-induced cell death. Finally, we observed that a minor population of caspase 3-deficient MCF-7 cells persisted during long-term treatment with lower doses of bozepinib and the bozepinib/IFNα combination. Curiously, this population showed β-galactosidase activity and a percentage of cells arrested in S phase, that was more evident in cells treated with the bozepinib/IFNα combination than in cells treated with bozepinib or IFNα alone. Considering the resistance of some cancer cells to conventional chemotherapy, combinations enhancing the diversity of the cell death outcome might succeed in delivering more effective and less toxic chemotherapy. PMID:24194639

Induction of brain tumor stem cell apoptosis by FTY720: a potential therapeutic agent for glioblastoma.

PubMed

Estrada-Bernal, Adriana; Palanichamy, Kamalakannan; Ray Chaudhury, Abhik; Van Brocklyn, James R

2012-04-01

FTY720 is a sphingosine analogue that down regulates expression of sphingosine-1-phosphate receptors and causes apoptosis of multiple tumor cell types, including glioma cells. This study examined the effect of FTY720 on brain tumor stem cells (BTSCs) derived from human glioblastoma (GBM) tissue. FTY720 treatment of BTSCs led to rapid inactivation of ERK MAP kinase, leading to upregulation of the BH3-only protein Bim and apoptosis. In combination with temozolomide (TMZ), the current standard chemotherapeutic agent for GBM, FTY720 synergistically induced BTSC apoptosis. FTY720 also slowed growth of intracranial xenograft tumors in nude mice and augmented the therapeutic effect of TMZ, leading to enhanced survival. Furthermore, the combination of FTY720 and TMZ decreased the invasiveness of BTSCs in mouse brains. FTY720 is known to cross the blood-brain barrier and recently received Food and Drug Administration approval for treatment of relapsing multiple sclerosis. Thus, FTY720 is an excellent potential therapeutic agent for treatment of GBM.

PPARγ and Apoptosis in Cancer

PubMed Central

Elrod, Heath A.; Sun, Shi-Yong

2008-01-01

Peroxisome proliferator-activated receptors (PPARs) are ligand binding transcription factors which function in many physiological roles including lipid metabolism, cell growth, differentiation, and apoptosis. PPARs and their ligands have been shown to play a role in cancer. In particular, PPARγ ligands including endogenous prostaglandins and the synthetic thiazolidinediones (TZDs) can induce apoptosis of cancer cells with antitumor activity. Thus, PPARγ ligands have a potential in both chemoprevention and therapy of several types of cancer either as single agents or in combination with other antitumor agents. Accordingly, the involvement of PPARγ and its ligands in regulation of apoptosis of cancer cells have been extensively studied. Depending on cell types or ligands, induction of apoptosis in cancer cells by PPARγ ligands can be either PPARγ-dependent or -independent. Through increasing our understanding of the mechanisms of PPARγ ligand-induced apoptosis, we can develop better strategies which may include combining other antitumor agents for PPARγ-targeted cancer chemoprevention and therapy. This review will highlight recent research advances on PPARγ and apoptosis in cancer. PMID:18615184

Role of gap junction intercellular communication in testicular leydig cell apoptosis induced by oxaliplatin via the mitochondrial pathway.

PubMed

Tong, Xuhui; Han, Xi; Yu, Binbin; Yu, Meiling; Jiang, Guojun; Ji, Jie; Dong, Shuying

2015-01-01

Platinum agents are widely used in the chemotherapy of testicular cancer. However, adverse reactions and resistance to such agents have limited their application in antineoplastic treatment. The aim of the present study was to determine the role of gap junction intercellular communication (GJIC) composed of Cx43 on oxaliplatin‑induced survival/apoptosis in mouse leydig normal and cancer cells using MTT, Annexin V/PI double staining assays and western blot analysis. The results showed that GJIC exerted opposite effects on the mouse leydig cancer (I-10) and normal (TM3) cell apoptosis induced by oxaliplatin. In leydig cancer cells, survival of cells exposed to oxaliplatin was substantially reduced when gap junctions formed as compared to no gap junctions. Pharmacological inhibition of gap junctions by oleamide and 18-α-glycyrrhetinic acid resulted in enhanced survival/decreased apoptosis while enhancement of gap junctions by retinoic acid led to decreased survival/increased apoptosis. These effects occurred only in high‑density cultures (gap junction formed), while the pharmacological modulations had no effects when there was no opportunity for gap junction formation. Notably, GJIC played an opposite (protective) role in normal leydig cells survival/apoptosis following exposure to oxaliplatin. Furthermore, this converse oxaliplatin‑inducing apoptosis exerted through the functional gap junction was correlated with the mitochondrial pathway‑related protein Bcl-2/Bax and caspase‑3/9. These results suggested that in testicular leydig normal/cancer cells, GJIC plays an opposite role in oxaliplatin‑induced apoptosis via the mitochondrial pathway.

Involvement of caspase-dependent and -independent apoptotic pathways in cisplatin-induced apoptosis

NASA Astrophysics Data System (ADS)

Liu, Lei; Zhang, Yingjie; Wang, Xianwang

2009-02-01

Cisplatin, an efficient anticancer agent, can trigger multiple apoptotic pathways in cancer cells. However, the signal transduction pathways in response to cisplatin-based chemotherapy are complicated, and the mechanism is not fully understood. In current study, we showed that, during cisplatin-induced apoptosis of human lung adenocarcinoma cells, both the caspase-dependent and -independent pathways were activated. Herein, we reported that after cisplatin treatment, the activities of caspase-9/-3 were sharply increased; pre-treatment with Z-LEHD-fmk (inhibitor of caspase-9), Z-DEVD-fmk (inhibitor of caspase-3), and Z-VAD-fmk (a pan-caspase inhibitor) increased cell viability and decreased apoptosis, suggesting that caspase-mediated apoptotic pathway was activated following cisplatin treatment. Confocal imaging of the cells transfected with AIF-GFP demonstrated that AIF release occurred about 9 h after cisplatin treatment. The event proceeded progressively over time, coinciding with a nuclear translocation and lasting for more than 2 hours. Down-regulation of AIF by siRNA also significantly increased cell viability and decreased apoptosis, these results suggested that AIF-mediated caspase-independent apoptotic pathway was involved in cispatin-induced apoptosis. In conclusion, the current study demonstrated that both caspase-dependent and -independent apoptotic pathways were involved in cisplatin-induced apoptosis in human lung adenocarcinoma cells.

Crizotinib induces apoptosis and gene expression changes in ALK+ anaplastic large cell lymphoma cell lines; brentuximab synergizes and doxorubicin antagonizes.

PubMed

Hudson, Sandra; Wang, Dongliang; Middleton, Frank; Nevaldine, Barbara H; Naous, Rana; Hutchison, Robert E

2018-04-26

Anaplastic lymphoma kinase (ALK)-positive anaplastic large cell lymphoma (ALCL) shows 60-70% event free survival with standard treatments. Targeted therapies are being tested for increased benefit and/or reduced toxicity, but interactions with standard agents are not well known. We exposed four ALCL cell lines to two targeted agents, crizotinib and brentuximab vedotin, and to two standard agents, doxorubicin and vinblastine. For each agent and combination, we measured apoptosis and expression of approximately 300 previously annotated genes of interest using targeted RNA-sequencing. An aurora kinase inhibitor, alisertib, was similarly tested for gene expression effects. Only crizotinib, alone or in combination, showed significant effects (adjusted P < 0.05) on expression and apoptosis. One hundred and nine of 277 gene expressions showed crizotinib-associated differential expression, mostly downregulation, 62 associated with apoptosis, and 28 associated with both crizotinib and apoptosis. Doxorubicin was antagonistic with crizotinib on gene expression and apoptosis. Brentuximab was synergistic with crizotinib in apoptosis, and not antagonistic in gene expression. Vinblastine also appeared synergistic with crizotinib but did not achieve statistical significance. Alisertib did not show significant expression changes. Our data suggest that crizotinib induces apoptosis through orderly changes in cell signaling associated with ALK inhibition. Expression effects of crizotinib and associated apoptosis are antagonized by doxorubicin, but apoptosis is synergized by brentuximab vedotin and possibly vinblastine. These findings suggest that concurrent use of crizotinib and doxorubicin may be counterproductive, while the pairing of crizotinib with brentuximab (or vinblastine) may increase efficacy. Alisertib did not induce expression changes at cytotoxic dosage. © 2018 Wiley Periodicals, Inc.

Modulation of Radiation-Induced Apoptosis by Thiolamines

NASA Technical Reports Server (NTRS)

Warters, R. L.; Roberts, J. C.; Wilmore, B. H.; Kelley, L. L.

1997-01-01

Exposure to the thiolamine radioprotector N-(2-mercaptoethyl)-1,3-propanediamine (WR-1065) induced apoptosis in the mouse TB8-3 hybridoma after 60-minute (LD(sub50) = 4.5mM) or during a 20-hour (LD(sub50) = 0.15 mM) exposure. In contrast, a 20-hour exposure to 17 mM L-cysteine or 10 mM cysteamine was required to induce 50 percent apoptosis within 20 hours. Apoptosis was not induced by either a 60-minute or 20-hour exposure to 10 mM of the thiazolidime prodrugs ribose-cysteine (RibCys) or ribose-cysteamine (RibCyst). Thiolamine-induced apoptosis appeared to be a p53-independent process since it was induced by WR-1065 exposure in human HL60 cells. Exposure to WR-1065 (4mM for 15 minutes) or cysteine (10mM for 60 minutes) before and during irradiation protected cells against the induction of both DNA double-strand breaks and apoptosis, while exposure to RibCys (10 mM for 3 hours) did not. Treatment with either WR-1065, cysteine, RibCys or RibCyst for 60 minutes beginning 60 minutes after irradiation did not affect the level of radiation-induced apoptosis. In contrast, treatment with either cysteine, cysteamine or RibCys for 20 hours beginning 60 minutes after irradiation enhanced radiation-induced apoptosis. Similar experiments could not be conducted with WR-1065 because of its extreme toxicity. Our results indicate that thiolamine enhancement of radiation-induced apoptosis is not involved in their previously reported capacity to reduce radiation-induced mutations.

Anti-apoptotic effect of phloretin on cisplatin-induced apoptosis in HEI-OC1 auditory cells.

PubMed

Choi, Byung-Min; Chen, Xiao Yan; Gao, Shang Shang; Zhu, Rizhe; Kim, Bok-Ryang

2011-01-01

Cisplatin is a highly effective chemotherapeutic agent, but it has significant ototoxic side effects. Apoptosis is an important mechanism of cochlear hair cell loss following exposure to cisplatin. The present study examined the effects of phloretin, a natural polyphenolic compound found in apples and pears, on cisplatin-induced apoptosis. We found that phloretin induced the expression of heme oxygenase-1 (HO-1) protein in a concentration- and time-dependent manner. Phloretin induced nuclear factor-E2-related factor 2 (Nrf2) nuclear translocation, and dominant-negative Nrf2 attenuated phloretin-induced expression of HO-1. Phloretin activated the JNK, ERK and p38 mitogen-activated protein kinase (MAPK) pathways, and the JNK pathway played an important role in phloretin-induced HO-1 expression. Phloretin protected the cells against cisplatin-induced apoptosis. The protective effect of phloretin was abrogated by zinc protoporphyrin IX (ZnPP IX), a HO inhibitor. Furthermore, phloretin pretreatment inhibited mitochondrial dysfunction and the activation of caspases. These results demonstrate that the expression of HO-1 induced by phloretin is mediated by both the JNK pathway and Nrf2; the expression inhibits cisplatin-induced apoptosis in HEI-OC1 cells.

Agarol, an ergosterol derivative from Agaricus blazei, induces caspase-independent apoptosis in human cancer cells.

PubMed

Shimizu, Takamitsu; Kawai, Junya; Ouchi, Kenji; Kikuchi, Haruhisa; Osima, Yoshiteru; Hidemi, Rikiishi

2016-04-01

Agaricus blazei (A. blazei) is a mushroom with many biological effects and active ingredients. We purified a tumoricidal substance from A. blazei, an ergosterol derivative, and named it 'Agarol'. Cytotoxic effects of Agarol were determined by the MTT assay using A549, MKN45, HSC-3, and HSC-4 human carcinoma cell lines treated with Agarol. Apoptosis was detected by flow cytometry analysis. Reactive oxygen species (ROS) levels and mitochondria membrane potential (∆ψm) were also determined by flow cytometry. Western blot analysis was used to quantify the expression of apoptosis-related proteins. Agarol predominantly induced apoptosis in two p53-wild cell lines (A549 and MKN45) compared to the other p53-mutant cell lines (HSC-3 and HSC-4). Further mechanistic studies revealed that induction of apoptosis is associated with increased generation of ROS, reduced ∆ψm, release of apoptosis-inducing factor (AIF) from the mitochondria to the cytosol, upregulation of Bax, and downregulation of Bcl-2. Caspase-3 activities did not increase, and z-VAD-fmk, a caspase inhibitor, did not inhibit the Agarol-induced apoptosis. These findings indicate that Agarol induces caspase-independent apoptosis in human carcinoma cells through a mitochondrial pathway. The in vivo anticancer activity of Agarol was confirmed in a xenograft murine model. This study suggests a molecular mechanism by which Agarol induces apoptosis in human carcinoma cells and indicates the potential use of Agarol as an anticancer agent.

Aspartame-induced apoptosis in PC12 cells.

PubMed

Horio, Yukari; Sun, Yongkun; Liu, Chuang; Saito, Takeshi; Kurasaki, Masaaki

2014-01-01

Aspartame is an artificial sweetner added to many low-calorie foods. The safety of aspartame remains controversial even though there are many studies on its risks. In this study, to understand the physiological effects of trace amounts of artificial sweetners on cells, the effects of aspartame on apoptosis were investigated using a PC12 cell system. In addition, the mechanism of apoptosis induced by aspartame in PC12 cells and effects on apoptotic factors such as cytochrome c, apoptosis-inducing factor, and caspase family proteins were studied by Western blotting and RT-PCR. Aspartame-induced apoptosis in PC12 cells in a dose-dependent manner. In addition, aspartame exposure increased the expressions of caspases 8 and 9, and cytochrome c. These results indicate that aspartame induces apoptosis mainly via mitochondrial pathway involved in apoptosis due to oxigen toxicity. Copyright © 2013 Elsevier B.V. All rights reserved.

The C. elegans TIA-1/TIAR homolog TIAR-1 is required to induce germ cell apoptosis.

PubMed

Silva-García, Carlos Giovanni; Estela Navarro, Rosa

2013-10-01

In Caenorhabditis elegans, physiological germ cell apoptosis eliminates more than half of the cells in the hermaphrodite gonad to support gamete quality and germline homeostasis by a still unidentified mechanism. External factors can also affect germ cell apoptosis. The BH3-only protein EGL-1 induces germ cell apoptosis when animals are exposed to pathogens or agents that produce DNA damage. DNA damage-induced apoptosis also requires the nematode p53 homolog CEP-1. Previously, we found that heat shock, oxidative, and osmotic stresses induce germ cell apoptosis through an EGL-1 and CEP-1 independent mechanism that requires the MAPKK pathway. However, we observed that starvation increases germ cell apoptosis by an unknown pathway. Searching for proteins that participate in stress-induced apoptosis, we found the RNA-binding protein TIAR-1 (a homolog of the mammalian TIA-1/TIAR family of proteins). Here, we show that TIAR-1 in C. elegans is required to induce apoptosis in the germline under several conditions. We also show that TIAR-1 acts downstream of CED-9 (a BCL2 homolog) to induce apoptosis under stress conditions, and apparently does not seem to regulate ced-4 or ced-3 mRNAs accumulation directly. TIAR-1 is expressed ubiquitously in the cytoplasm of the soma as well as the germline, where it sometimes associates with P granules. We show that animals lacking TIAR-1 expression are temperature sensitive sterile due to oogenesis and spermatogenesis defects. Our work shows that TIAR-1 is required for proper germline function and demonstrates that this protein is important to induce germ cell apoptosis under several conditions. Copyright © 2013 Wiley Periodicals, Inc.

Procaspase-activating compound-1 induces apoptosis in Trypanosoma cruzi.

PubMed

de Castro, Emanuella; Reus, Thamile Luciane; de Aguiar, Alessandra Melo; Ávila, Andrea Rodrigues; de Arruda Campos Brasil de Souza, Tatiana

2017-12-01

Some therapeutics for parasitic, cardiac and neurological diseases activate apoptosis. Therefore, the study of apoptotic proteins in pathogenic organisms is relevant. However, the molecular mechanism of apoptosis in unicellular organisms remain elusive, despite morphological evidence of its occurrence. In Trypanosoma cruzi, the causative agent of Chagas disease, metacaspase 3 (TcMCA3), seems to have a key role in parasite apoptosis. Accordingly, this work provides data concerning TcMCA3 regulation through its interaction with procaspase-activating compound 1 (PAC-1), a procaspase 3 activator. Indeed, PAC-1 reduced T. cruzi epimastigote viability with an IC 50 of 14.12 µM and induced loss of mitochondrial potential and exposure of phosphatidylserine, features of the apoptotic process. Notwithstanding, those PAC-1-inducible effects were not conserved in metacyclic trypomastigotes. Moreover, PAC-1 reduced the viability of mammalian cells with a greater IC 50 (25.70 µM) compared to T. cruzi epimastigotes, indicating distinct modes of binding between caspases and metacaspases. To shed light on the selectivity of metacaspases and caspases, we determined the structural features related to the PAC-1 binding sites in both types of proteins. These data are important for improving the understanding of the apoptosis pathway in T. cruzi so that TcMCA3 could be better targeted with future pharmaceuticals.

Cyanidin-3-glucoside isolated from mulberry fruit protects pancreatic β-cells against oxidative stress-induced apoptosis.

PubMed

Lee, Jong Seok; Kim, Young Rae; Song, In Gyu; Ha, Suk-Jin; Kim, Young Eon; Baek, Nam-In; Hong, Eock Kee

2015-02-01

The extract obtained from berries contains high amounts of anthocyanins, and this extract is used as a phytotherapeutic agent for different types of diseases. In this study, we examined the cytoprotective effects of cyanidin-3-glucoside (C3G) isolated from mulberry fruit against pancreatic β-cell apoptosis caused by hydrogen peroxide (H2O2)-induced oxidative stress. The MIN6 pancreatic β-cells were used to investigate the cytoprotective effects of C3G on the oxidative stress-induced apoptosis of cells. Cell viability was examined by MTT assay and lipid peroxidation was assayed by thiobarbituric acid (TBA) reaction. Immunofluorescence staining, flow cytometry and western blot analysis were also used to determine apoptosis and the expression of proteins associated with apoptosis. Our results revealed that H2O2 increased the rate of apoptosis by stimulating various pro-apoptotic processes, such as the generation of intracellular reactive oxygen species (ROS), lipid peroxidation, DNA fragmentation and caspase-3 activation. However, C3G reduced the H2O2-induced cell death in the MIN6N pancreatic β-cells. In addition, we confirmed that H2O2 activated mitogen-activated protein kinases (MAPKs), such as extracellular signal-regulated kinase (ERK), c-Jun NH2-terminal kinase (JNK) and p38 MAPK. C3G inhibited the phosphorylation of ERK and p38 without inducing the phosphorylation of JNK. Furthermore, C3G regulated the intrinsic apoptotic pathway-associated proteins, such as proteins belonging to the Bcl-2 family, cytochrome c and caspase-3. Taken together, our results suggest that C3G isolated from mulberry fruit has potential for use as a phytotherapeutic agent for the prevention of diabetes by preventing oxidative stress-induced β-cell apoptosis.

Fluoride Induces Apoptosis in Mammalian Cells: In Vitro and In Vivo Studies.

PubMed

Ribeiro, Daniel Araki; Cardoso, Caroline Margonato; Yujra, Veronica Quispe; DE Barros Viana, Milena; Aguiar, Odair; Pisani, Luciana Pellegrini; Oshima, Celina Tizuko Fujiyama

2017-09-01

Apoptosis is genetically programmed cell death, an irreversible process of cell senescence with characteristic features different from other cellular mechanisms of death such as necrosis. In the last years, apoptosis has been extensively studied in the scientific literature, because it has been established that apoptosis plays a crucial role following the time course of chronic degenerative diseases, such as cancer. Thus, several researchers have strugged to detect what chemical agents are able to inter fere with the apoptotic process. Thus, the purpose of this literature review is to assess if fluoride induces apoptosis in mammalian cells using in vivo and in vitro test systems. Certain mammalian cell types such as oral cells, blood and brain were exetensively investigated; the results showed that fluoride is able to induce apoptosis in both intrinsinc and extrinsic pathways. Moreover, other cells types have been poorly investigated such as bone, kidney and reproductive cells with conflicting results so far. Therefore, this area needs further investigation for the safety of human populations exposed to fluoride in a chronic way, as for example in developing countries. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Licochalcone C induces apoptosis via B-cell lymphoma 2 family proteins in T24 cells.

PubMed

Wang, Penglong; Yuan, Xuan; Wang, Yan; Zhao, Hong; Sun, Xiling; Zheng, Qiusheng

2015-11-01

The current study investigated the mechanisms by which licochalcone C induces apoptosis of T24 human malignant bladder cancer cells. Cell viability was evaluated using an MTT assay. Apoptosis was investigated using a morphological assay, flow cytometry and a caspase‑3 activity assay. Alterations in the gene expression levels of Bcl‑2 family members were measured by semi‑quantitative reverse transcription‑polymerase chain reaction assays. The protein levels of pro‑caspase‑3 and cleaved poly(ADP ribose) polymerase were measured using western blotting. The results indicated that licochalcone C induced T24 cell apoptosis in a concentration‑dependent manner. Licochalcone C treatment reduced the levels of the anti‑apoptotic mRNAs (Bcl‑2, Bcl‑w and Bcl‑XL) and increased expression of the pro‑apoptotic mRNAs (Bax and Bim). The Bcl‑2 family inhibitor (ABT‑737) reduced apoptosis induced by licochalcone C in T24 cells. The current study demonstrated that licochalcone C may be a potential adjuvant therapeutic agent for bladder cancer.

A synthetic peptide targeting the BH4 domain of Bcl-2 induces apoptosis in multiple myeloma and follicular lymphoma cells alone or in combination with agents targeting the BH3-binding pocket of Bcl-2.

PubMed

Lavik, Andrew R; Zhong, Fei; Chang, Ming-Jin; Greenberg, Edward; Choudhary, Yuvraj; Smith, Mitchell R; McColl, Karen S; Pink, John; Reu, Frederic J; Matsuyama, Shigemi; Distelhorst, Clark W

2015-09-29

Bcl-2 inhibits apoptosis by two distinct mechanisms but only one is targeted to treat Bcl-2-positive malignancies. In this mechanism, the BH1-3 domains of Bcl-2 form a hydrophobic pocket, binding and inhibiting pro-apoptotic proteins, including Bim. In the other mechanism, the BH4 domain mediates interaction of Bcl-2 with inositol 1,4, 5-trisphosphate receptors (IP3Rs), inhibiting pro-apoptotic Ca2+ signals. The current anti-Bcl-2 agents, ABT-263 (Navitoclax) and ABT-199 (Venetoclax), induce apoptosis by displacing pro-apoptotic proteins from the hydrophobic pocket, but do not inhibit Bcl-2-IP3R interaction. Therefore, to target this interaction we developed BIRD-2 (Bcl-2 IP3 Receptor Disruptor-2), a decoy peptide that binds to the BH4 domain, blocking Bcl-2-IP3R interaction and thus inducing Ca2+-mediated apoptosis in chronic lymphocytic leukemia, multiple myeloma, and follicular lymphoma cells, including cells resistant to ABT-263, ABT-199, or the Bruton's tyrosine kinase inhibitor Ibrutinib. Moreover, combining BIRD-2 with ABT-263 or ABT-199 enhances apoptosis induction compared to single agent treatment. Overall, these findings provide strong rationale for developing novel therapeutic agents that mimic the action of BIRD-2 in targeting the BH4 domain of Bcl-2 and disrupting Bcl-2-IP3R interaction.

Age-related differential responses to curcumin-induced apoptosis during the initiation of colon cancer in rats.

PubMed

Kwon, Youngjoo; Magnuson, Bernadene A

2009-02-01

Curcumin is a widely-used dietary supplement and a chemopreventive agent for various cancers. Pre-clinical chemopreventive studies rarely consider the effect of aging. We previously reported that unlike young animals, curcumin is ineffective in middle-aged rats for colon chemoprevention. This study investigated whether resistance to apoptosis during cancer initiation contributes to this age-dependent effect. Young, middle-aged, and old F344 rats were fed either curcumin (0.6%) or control diet. Colonic apoptosis was evaluated 0, 8, and 16 h after azoxymethane (AOM) injection. Colonic Hsp70 mRNA levels, caspase-9 activity, cell proliferation, and crypt morphology were measured. In AOM-treated rats, only middle-aged rats were resistant to curcumin-induced apoptosis whereas cell proliferation was reduced by curcumin in all ages. Curcumin-induced apoptosis was mediated by caspase-9 in young but not older rats. Transcriptional Hsp70 expression was induced in only young rats and was suppressed by curcumin. Therefore, the age-related difference in curcumin chemoprevention is due to a differential response in induction of apoptosis. The mitochondria-dependent pathway seems to mediate curcumin-induced apoptosis in young but not older animals. Hsp70 expression was not related with resistance to curcumin-induced apoptosis. Understanding age-related differences in the apoptotic response may lead to improved translation from pre-clinical animal studies to humans.

Mitochondrial dysfunction in lyssavirus-induced apoptosis.

PubMed

Gholami, Alireza; Kassis, Raïd; Real, Eléonore; Delmas, Olivier; Guadagnini, Stéphanie; Larrous, Florence; Obach, Dorothée; Prevost, Marie-Christine; Jacob, Yves; Bourhy, Hervé

2008-05-01

Lyssaviruses are highly neurotropic viruses associated with neuronal apoptosis. Previous observations have indicated that the matrix proteins (M) of some lyssaviruses induce strong neuronal apoptosis. However, the molecular mechanism(s) involved in this phenomenon is still unknown. We show that for Mokola virus (MOK), a lyssavirus of low pathogenicity, the M (M-MOK) targets mitochondria, disrupts the mitochondrial morphology, and induces apoptosis. Our analysis of truncated M-MOK mutants suggests that the information required for efficient mitochondrial targeting and dysfunction, as well as caspase-9 activation and apoptosis, is held between residues 46 and 110 of M-MOK. We used a yeast two-hybrid approach, a coimmunoprecipitation assay, and confocal microscopy to demonstrate that M-MOK physically associates with the subunit I of the cytochrome c (cyt-c) oxidase (CcO) of the mitochondrial respiratory chain; this is in contrast to the M of the highly pathogenic Thailand lyssavirus (M-THA). M-MOK expression induces a significant decrease in CcO activity, which is not the case with M-THA. M-MOK mutations (K77R and N81E) resulting in a similar sequence to M-THA at positions 77 and 81 annul cyt-c release and apoptosis and restore CcO activity. As expected, the reverse mutations, R77K and E81N, introduced in M-THA induce a phenotype similar to that due to M-MOK. These features indicate a novel mechanism for energy depletion during lyssavirus-induced apoptosis.

Role of Apollon in Human Melanoma Resistance to Antitumor Agents That Activate the Intrinsic or the Extrinsic Apoptosis Pathways

PubMed Central

Tassi, Elena; Zanon, Marina; Vegetti, Claudia; Molla, Alessandra; Bersani, Ilaria; Perotti, Valentina; Pennati, Marzia; Zaffaroni, Nadia; Milella, Michele; Ferrone, Soldano; Carlo-Stella, Carmelo; Gianni, Alessandro M.; Mortarini, Roberta; Anichini, Andrea

2012-01-01

Purpose To assess the role of Apollon in melanoma resistance to intrinsic and extrinsic pathways of apoptosis and to identify strategies to reduce its expression. Experimental Design Apollon expression was assessed in melanoma cells in vitro and in vivo. Apollon modulation and melanoma apoptosis were evaluated by Western blot and/or flow cytometry in response to cytotoxic drugs, mitogen-activated protein/extracellular signal–regulated kinase (MEK)-, BRAFV600E-, and mTOR-specific inhibitors, TRAIL and anti-HLA class II monoclonal antibodies (mAb). Mitochondrial depolarization, caspase activation, apoptosis assays, and gene expression profiling were used to test effects of Apollon silencing, by siRNA, on melanoma response to antitumor agents. Results Apollon was constitutively expressed by melanoma cells, in vitro and in vivo, and at higher levels than in benign melanocytic lesions. Melanoma apoptosis correlated significantly with Apollon protein downmodulation in response to cytotoxic drugs, MEK, or BRAFV600E-specific inhibitors. Combinatorial treatment with MEK and mTOR inhibitors and HLA class II ligation, by a specific mAb, promoted Apollon downmodulation and enhanced melanoma apoptosis. Apollon downmodulation induced by antitumor agents was caspase independent, but proteasome dependent. Knockdown of Apollon, by siRNA, triggered apoptosis and/or significantly enhanced melanoma cell death in response to cytotoxic drugs, MEK- and BRAFV600E-specific inhibitors, and soluble or membrane-bound TRAIL. Apollon silencing promoted mitochondrial depolarization and caspase-2, caspase-8, caspase-9, and caspase-3 activation in response to different antitumor agents and altered the profile of genes modulated by MEK or BRAFV600E-specific inhibitors. Conclusions Targeting of Apollon may significantly improve melanoma cell death in response to antitumor agents that trigger the intrinsic or the extrinsic apoptosis pathways. PMID:22553342

TNF-related apoptosis-inducing ligand (TRAIL): A new path to anti-cancer therapies

PubMed Central

Holoch, Peter A.; Griffith, Thomas S.

2009-01-01

Since its discovery in 1995, tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), a member of the tumor necrosis factor super family, has been under intense focus because of its remarkable ability to induce apoptosis in malignant human cells while leaving normal cells unscathed. Consequently, activation of the apoptotic signaling pathway from the death-inducing TRAIL receptors provides an attractive, biologically-targeted approach to cancer therapy. A great deal of research has focused on deciphering the TRAIL receptor signaling cascade and intracellular regulation of this pathway, as many human tumor cells possess mechanisms of resistance to TRAIL-induced apoptosis. This review focuses on the currently state of knowledge regarding TRAIL signaling and resistance, the preclinical development of therapies targeted at TRAIL receptors and modulators of the pathway, and the results of clinical trials for cancer treatment that have emerged from this base of knowledge. TRAIL-based approaches to cancer therapy vary from systemic administration of recombinant, soluble TRAIL protein with or without the combination of traditional chemotherapy, radiation or novel anticancer agents to agonistic monoclonal antibodies directed against functional TRAIL receptors to TRAIL gene transfer therapy. A better understanding of TRAIL resistance mechanisms may allow for the development of more effective therapies that exploit this cell-mediated pathway to apoptosis. PMID:19836385

A new tellurium-containing amphiphilic molecule induces apoptosis in HCT116 colon cancer cells.

PubMed

Du, Peng; Saidu, Nathaniel Edward Bennett; Intemann, Johanna; Jacob, Claus; Montenarh, Mathias

2014-06-01

Chalcogen-based redox modulators over the years have attracted considerable attention as anti-cancer agents. New selenium- and tellurium-containing compounds with a polar head group and aryl-groups of various lengths have recently been reported as biologically active in several organisms. In the present study, we used the most active of the tellurium compound DP41, and its selenium counterpart DP31 to investigate their effects on the human cancer cell line HCT116. Cells were treated with DP41 or DP31 and the formation of superoxide radicals was determined using dihydroethidium. Cell cycle analysis and apoptosis was determined by cytofluorimetry. Proteins involved in ER signaling and apoptosis were determined by Western blot analysis and fluorescence microscopy. With 50μM of DP41, we observed an increase in O2(-) formation. There was, however, no such increase in O2(-) after treatment with the corresponding selenium compound under the same conditions. In the case of DP41, the production of O2(-) radicals was followed by an up-regulation of Nrf2, HO-1, phospho-eIF2α and ATF4. CHOP was also induced and cells entered apoptosis. Unlike the cancer cells, normal retinal epithelial ARPE-19 cells did not produce elevated levels of O2(-) radicals nor did they induce the ER signaling pathway or apoptosis. The tellurium-containing compound DP41, in contrast to the corresponding selenium compound, induces O2(-) radical formation and oxidative and ER stress responses, including CHOP activation and finally apoptosis. These results indicate that DP41 is a redox modulating agent with promising anti-cancer potentials. Copyright © 2014 Elsevier B.V. All rights reserved.

Novel sila-amide derivatives of N-acetylcysteine protects platelets from oxidative stress-induced apoptosis.

PubMed

Paul, Manoj; Thushara, Ram M; Jagadish, Swamy; Zakai, Uzma I; West, Robert; Kemparaju, Kempaiah; Girish, Kesturu S

2017-02-01

Oxidative stress-induced platelet apoptosis is one among the many causes for the development and progression of many disorders like cardiovascular diseases, arthritis, Alzheimer's disease and many chronic inflammatory responses. Many studies have demonstrated the less optimal effect of N-acetyl cysteine (NAC) in oxidative stress-induced cellular damage. This could be due to its less lipophilicity which makes it difficult to enter the cellular membrane. Therefore in the present study, lipophilic sila-amide derivatives (6a and 6b) synthesized through the reaction of NAC with 3-Aminopropyltrimethylsilane and aminomethyltrimethylsilane were used to determine their protective property against oxidative stress-induced platelet apoptosis. At a concentration of 10 µM, compound 6a and 6b were able to significantly inhibit Rotenone/H 2 O 2 induced platelet apoptotic markers like reactive oxygen species, intracellular calcium level, mitochondrial membrane potential, cytochrome c release from mitochondrial to the cytosol, caspase-9 and -3 activity and phosphatidylserine externalization. Therefore, the compounds can be extrapolated as therapeutic agents to protect platelets from oxidative stress-induced platelet apoptosis and its associated complications.

Acetyl-CoA carboxylase-alpha inhibitor TOFA induces human cancer cell apoptosis.

PubMed

Wang, Chun; Xu, Canxin; Sun, Mingwei; Luo, Dixian; Liao, Duan-Fang; Cao, Deliang

2009-07-31

Acetyl-CoA carboxylase-alpha (ACCA) is a rate-limiting enzyme in long chain fatty acid synthesis, playing a critical role in cellular energy storage and lipid synthesis. ACCA is upregulated in multiple types of human cancers and small interfering RNA-mediated ACCA silencing in human breast and prostate cancer cells results in oxidative stress and apoptosis. This study reports for the first time that TOFA (5-tetradecyloxy-2-furoic acid), an allosteric inhibitor of ACCA, is cytotoxic to lung cancer cells NCI-H460 and colon carcinoma cells HCT-8 and HCT-15, with an IC(50) at approximately 5.0, 5.0, and 4.5 microg/ml, respectively. TOFA at 1.0-20.0 microg/ml effectively blocked fatty acid synthesis and induced cell death in a dose-dependent manner. The cell death was characterized with PARP cleavage, DNA fragmentation, and annexin-V staining, all of which are the features of the apoptosis. Supplementing simultaneously the cells with palmitic acids (100 microM), the end-products of the fatty acid synthesis pathway, prevented the apoptosis induced by TOFA. Taken together, these data suggest that TOFA is a potent cytotoxic agent to lung and colon cancer cells, inducing apoptosis through disturbing their fatty acid synthesis.

Acetyl-CoA Carboxylase-α Inhibitor TOFA Induces Human Cancer Cell Apoptosis

PubMed Central

Wang, Chun; Xu, Canxin; Sun, Mingwei; Luo, Dixian; Liao, Duan-fang; Cao, Deliang

2009-01-01

Acetyl-CoA carboxylase-α (ACCA) is a rate-limiting enzyme in long chain fatty acid synthesis, playing a critical role in cellular energy storage and lipid synthesis. ACCA is upregulated in multiple types of human cancers and small interfering RNA-mediated ACCA silencing in human breast and prostate cancer cells results in oxidative stress and apoptosis. This study reports for the first time that TOFA (5-tetradecyloxy-2-furoic acid), an allosteric inhibitor of ACCA, is cytotoxic to lung cancer cells NCI-H460 and colon carcinoma cells HCT-8 and HCT-15, with an IC50 at approximately 5.0, 5.0, and 4.5 μg/ml, respectively. TOFA at 1.0–20.0 μg/ml effectively blocked fatty acid synthesis and induced cell death in a dose-dependent manner. The cell death was characterized with PARP cleavage, DNA fragmentation, and annexin-V staining, all of which are the features of the apoptosis. Supplementing simultaneously the cells with palmitic acids (100 μM), the end-products of the fatty acid synthesis pathway, prevented the apoptosis induced by TOFA. Taken together, these data suggest that TOFA is a potent cytotoxic agent to lung and colon cancer cells, inducing apoptosis through disturbing their fatty acid synthesis. PMID:19450551

α-Lipoic acid inhibits sevoflurane-induced neuronal apoptosis through PI3K/Akt signalling pathway.

PubMed

Ma, Rong; Wang, Xiang; Peng, Peipei; Xiong, Jingwei; Dong, Hongquan; Wang, Lixia; Ding, Zhengnian

2016-01-01

Sevoflurane is a widely used anaesthetic agent, including in anaesthesia of children and infants. Recent studies indicated that the general anaesthesia might cause the cell apoptosis in the brain. This issue raises the concerns about the neuronal toxicity induced by the application of anaesthetic agents, especially in the infants and young children. In this study, we used Morris water maze, western blotting and immunohistochemistry to elucidate the role of α-lipoic acid in the inhibition of neuronal apoptosis. We found that sevoflurane led to the long-term cognitive impairment in the young rats. This adverse effect may be caused by the neuronal death in the hippocampal region, mediated through PI3K/Akt signalling pathway. We also showed that α-lipoic acid offset the effect of sevoflurane on the neuronal apoptosis and cognitive dysfunction. This study elucidated the potential clinical role of α-lipoic acid, providing a promising way in the prevention and treatment of long-term cognitive impairment induced by sevoflurane general anesthesia. Copyright © 2016 John Wiley & Sons, Ltd.

Artesunate induces AIF-dependent apoptosis in A549 cells

NASA Astrophysics Data System (ADS)

Zhou, Chen-juan; Chen, Tong-Sheng

2012-03-01

Artesunate (ART), a semi-synthetic derivative of the sesquiterpene artemisinin extracted from the Chinese herb Artemisia annua, exerts a broad spectrum of clinical activity against human cancers. It has been shown that ART induces cancer cells death through apoptosis pathway. This study investigated whether ART treatment induced reactive oxygen species (ROS)-dependent cell death in the apoptosis fashion in human lung adenocarconoma A549 cell line and the proapoptotic protein apoptosis inducing factor (AIF) is involved in ART-induced apoptosis. Cells treated with ART exhibited typical apoptotic morphology as chromatin condensation, margination and shrunken nucleus. ART treatment also induced a loss of mitochondrial membrane potential and AIF release from mitochondria. Silencing AIF can remarkable attenuated ART-induced apoptosis. Collectively, ART induces apoptosis by caspase-independent intrinsic pathway in A549 cells.

Mangiferin induces apoptosis in multiple myeloma cell lines by suppressing the activation of nuclear factor kappa B-inducing kinase.

PubMed

Takeda, Tomoya; Tsubaki, Masanobu; Kino, Toshiki; Yamagishi, Misa; Iida, Megumi; Itoh, Tatsuki; Imano, Motohiro; Tanabe, Genzoh; Muraoka, Osamu; Satou, Takao; Nishida, Shozo

2016-05-05

Mangiferin is a naturally occurring glucosyl xanthone, which induces apoptosis in various cancer cells. However, the molecular mechanism underlying mangiferin-induced apoptosis has not been clarified thus far. Therefore, we examined the molecular mechanism underlying mangiferin-induced apoptosis in multiple myeloma (MM) cell lines. We found that mangiferin decreased the viability of MM cell lines in a concentration-dependent manner. We also observed an increased number of apoptotic cells, caspase-3 activation, and a decrease in the mitochondrial membrane potential. In addition, mangiferin inhibited the nuclear translocation of nuclear factor kappa B (NF-κB) and expression of phosphorylated inhibitor kappa B (IκB) and increased the expression of IκB protein, whereas no changes were observed in the phosphorylation levels of extracellular signal-regulated kinase 1/2 (ERK1/2), c-Jun N-terminal protein kinase 1/2 (JNK1/2), and mammalian target of rapamycin (mTOR). The molecular mechanism responsible for mangiferin-induced inhibition of nuclear translocation of NF-κB was a decrease in the expression of phosphorylated NF-κB-inducing kinase (NIK). Moreover, mangiferin decreased the expression of X-linked inhibitor of apoptosis protein (XIAP), survivin, and Bcl-xL proteins. Knockdown of NIK expression showed results similar to those observed with mangiferin treatment. Our results suggest that mangiferin induces apoptosis through the inhibition of nuclear translocation of NF-κB by suppressing NIK activation in MM cell lines. Our results provide a new insight into the molecular mechanism of mangiferin-induced apoptosis. Importantly, since the number of reported NIK inhibitors is limited, mangiferin, which targets NIK, may be a potential anticancer agent for the treatment of MM. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

A microtubule inhibitor, ABT-751, induces autophagy and delays apoptosis in Huh-7 cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wei, Ren-Jie

The objective was to investigate the upstream mechanisms of apoptosis which were triggered by a novel anti-microtubule drug, ABT-751, in hepatocellular carcinoma-derived Huh-7 cells. Effects of ABT-751 were evaluated by immunocytochemistry, flow cytometric, alkaline comet, soft agar, immunoblotting, CytoID, green fluorescent protein-microtubule associated protein 1 light chain 3 beta detection, plasmid transfection, nuclear/cytosol fractionation, coimmunoprecipitation, quantitative reverse transcription-polymerase chain reaction, small-hairpin RNA interference and mitochondria/cytosol fractionation assays. Results showed that ABT-751 caused dysregulation of microtubule, collapse of mitochondrial membrane potential, generation of reactive oxygen species (ROS), DNA damage, G{sub 2}/M cell cycle arrest, inhibition of anchorage-independent cell growth and apoptosismore » in Huh-7 cells. ABT-751 also induced early autophagy via upregulation of nuclear TP53 and downregulation of the AKT serine/threonine kinase (AKT)/mechanistic target of rapamycin (MTOR) pathway. Through modulation of the expression levels of DNA damage checkpoint proteins and G{sub 2}/M cell cycle regulators, ABT-751 induced G{sub 2}/M cell cycle arrest. Subsequently, ABT-751 triggered apoptosis with marked downregulation of B-cell CLL/lymphoma 2, upregulation of mitochondrial BCL2 antagonist/killer 1 and BCL2 like 11 protein levels, and cleavages of caspase 8 (CASP8), CASP9, CASP3 and DNA fragmentation factor subunit alpha proteins. Suppression of ROS significantly decreased ABT-751-induced autophagic and apoptotic cells. Pharmacological inhibition of autophagy significantly increased the percentages of ABT-751-induced apoptotic cells. The autophagy induced by ABT-751 plays a protective role to postpone apoptosis by exerting adaptive responses following microtubule damage, ROS and/or impaired mitochondria. - Highlights: • An anti-microtubule agent, ABT-751, induces autophagy and apoptosis in Huh-7

CIP-36, a novel topoisomerase II-targeting agent, induces the apoptosis of multidrug-resistant cancer cells in vitro.

PubMed

Cao, Bo; Chen, Hong; Gao, Ying; Niu, Cong; Zhang, Yuan; Li, Ling

2015-03-01

The need to overcome cancer multidrug resistance (MDR) has fueled considerable interest in the development of novel synthetic antitumor agents with cytotoxicity against cancer cell lines with MDR. In this study, we aimed to investigate CIP-36, a novel podophyllotoxin derivative, for its inhibitory effects on human cancer cells from multiple sources, particularly cells with MDR in vitro. The human leukemia cell line, K562, and the adriamycin-resistant subline, K562/A02, were exposed to CIP-36 or anticancer agents, and various morphological and biochemical properties were assessed by Hoechst 33342 staining under a fluorescence microscope. Subsequently, cytotoxicity, cell growth curves and the cell cycle were analyzed. Finally, the effects of CIP-36 on topoisomerase IIα (Topo IIα) activity were determined. Treatment with CIP-36 significantly inhibited the growth of the K562 and MDR K562/A02 cells. Our data demonstrated that CIP-36 induced apoptosis, inhibited cell cycle progression and inhibited Topo IIα activity. These findings suggest that CIP-36 has the potential to overcome the multidrug resistance of K562/A02 cells by mediating Topo IIα activity.

Measurement of caspase-2 activation during different anti-tumor drugs induced apoptosis by FRET technique

NASA Astrophysics Data System (ADS)

Lin, Juqiang; Zeng, Shaoqun; Luo, Qingming; Rong, Chen; Zhang, Zhihong

2007-11-01

Caspase-2 is important for the engagement of the mitochondrial apoptotic pathway, in the presence of DNA-damaging agents, such as cisplatin; however, the mechanism by which caspase-2 executes apoptosis remains obscure. In this study, we carried out the measurements of the dynamics of caspase-2 activation in a single living cell by a FRET (fluorescence resonance energy transfer) probe. A FRET probe was constructed that encoded a CRS (caspase-2 recognition site) fused with a cyan fluorescent protein (CFP) and a red fluorescent protein (DsRed) (CFP-CRS-DsRed). Using this probe, we found that during TRAIL-induced apoptosis, caspase-2 was not activated, and caspase-2 activation occurred in etoposide and cisplatin treated cells. However, during cisplatin-induced apoptosis caspase-2 activation was initiated much earlier than that of etoposide. Cisplatin and etoposide is one of the most broadly used drugs in the Clinical applications of cancer chemotherapy, and TRAIL, which belongs to the TNF family proteins, can selectively induce apoptosis in many transformed cells but not in normal cells. Most of anticancer drugs can induce apoptosis mediated by the activation of caspase pathway. Thus, the perfect synergistic effect group of multi-drug can be selected by using our FRET probe.

Heat shock protein inhibitors, 17-DMAG and KNK437, enhance arsenic trioxide-induced mitotic apoptosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu Yichen; Yen Wenyen; Institute of Biomedical Sciences, Academia Sinica, Taipei 115, Taiwan

2009-04-15

Arsenic trioxide (ATO) has recently emerged as a promising therapeutic agent in leukemia because of its ability to induce apoptosis. However, there is no sufficient evidence to support its therapeutic use for other types of cancers. In this study, we investigated if, and how, 17-dimethylaminoethylamino-17-demethoxy-geldanamycin (17-DMAG), an antagonist of heat shock protein 90 (HSP90), and KNK437, a HSP synthesis inhibitor, potentiated the cytotoxic effect of ATO. Our results showed that cotreatment with ATO and either 17-DMAG or KNK437 significantly increased ATO-induced cell death and apoptosis. siRNA-mediated attenuation of the expression of the inducible isoform of HSP70 (HSP70i) or HSP90{alpha}/{beta} alsomore » enhanced ATO-induced apoptosis. In addition, cotreatment with ATO and 17-DMAG or KNK437 significantly increased ATO-induced mitotic arrest and ATO-induced BUBR1 phosphorylation and PDS1 accumulation. Cotreatment also significantly increased the percentage of mitotic cells with abnormal mitotic spindles and promoted metaphase arrest as compared to ATO treatment alone. These results indicated that 17-DMAG or KNK437 may enhance ATO cytotoxicity by potentiating mitotic arrest and mitotic apoptosis possibly through increased activation of the spindle checkpoint.« less

Chk2 mediates RITA-induced apoptosis.

PubMed

de Lange, J; Verlaan-de Vries, M; Teunisse, A F A S; Jochemsen, A G

2012-06-01

Reactivation of the p53 tumor-suppressor protein by small molecules like Nutlin-3 and RITA (reactivation of p53 and induction of tumor cell apoptosis) is a promising strategy for cancer therapy. The molecular mechanisms involved in the responses to RITA remain enigmatic. Several groups reported the induction of a p53-dependent DNA damage response. Furthermore, the existence of a p53-dependent S-phase checkpoint has been suggested, involving the checkpoint kinase Chk1. We have recently shown synergistic induction of apoptosis by RITA in combination with Nutlin-3, and we observed concomitant Chk2 phosphorylation. Therefore, we investigated whether Chk2 contributes to the cellular responses to RITA. Strikingly, the induction of apoptosis seemed entirely Chk2 dependent. Transcriptional activity of p53 in response to RITA required the presence of Chk2. A partial rescue of apoptosis observed in Noxa knockdown cells emphasized the relevance of p53 transcriptional activity for RITA-induced apoptosis. In addition, we observed an early p53- and Chk2-dependent block of DNA replication upon RITA treatment. Replicating cells seemed more prone to entering RITA-induced apoptosis. Furthermore, the RITA-induced DNA damage response, which was not a secondary effect of apoptosis induction, was strongly attenuated in cells lacking p53 or Chk2. In conclusion, we identified Chk2 as an essential mediator of the cellular responses to RITA.

Real-time single cell analysis of Bid cleavage and translocation in cisplatin-induced apoptosis

NASA Astrophysics Data System (ADS)

Liu, Lei; Xing, Da; Pei, Yihui; Chen, Wei R.

2007-02-01

Cancer cell apoptosis can be induced by cisplatin, an efficient anticancer agent. However, its mechanism is not fully understood. Bcl-2 homology domain (BH) 3-only proteins couple stress signals to mitochondrial apoptotic pathways. Calpain-mediated cleavage of the BH3-only protein Bid into a 14 kD truncated protein (tBid) has been implicated in cisplatin-induced apoptotic pathway. We utilized a recombinant fluorescence resonance energy transfer (FRET) Bid probe to determine the kinetics of Bid cleavage during cisplatin-induced apoptosis in ASTC-a-1 cells. The cells were also co-transfected with Bid-CFP and DsRed-Mit to dynamically detect tBid translocation. Cells showed a cleavage of the Bid-FRET probe occurring at about 4-5 h after treated with 20 µM cisplatin. Cleavage of the Bid-FRET probe coincided with a translocation of tBid from the cytosolic to the mitochondria, and the translocation lasted about 1.5 h. Using real-time single-cell analysis, we first observed the kinetics of Bid cleavage and translocation to mitochondria in living cells during cisplatin-induced apoptosis.

S-Allylmercaptocysteine Attenuates Cisplatin-Induced Nephrotoxicity through Suppression of Apoptosis, Oxidative Stress, and Inflammation

PubMed Central

Zhu, Xiaosong; Jiang, Xiaoyan; Li, Ang; Zhao, Zhongxi; Li, Siying

2017-01-01

Cisplatin is a potent chemotherapeutic agent, but its clinical usage is limited by nephrotoxicity. S-allylmercaptocysteine (SAMC), one of the water-soluble organosulfur garlic derivatives, has antioxidant and anti-inflammatory properties and plays an important role in protecting cells from apoptosis. This study aims to examine the protective effects of SAMC on cisplatin nephrotoxicity and to explore the mechanism of its renoprotection. Rats were treated with cisplatin with or without pre-treatment with SAMC. Renal function, histological change, oxidative stress markers and antioxidant enzyme activities were investigated. Apoptotic marker, nuclearfactor (NF)-κB activity, expression of nuclear factor erythroid 2-related factor 2 (Nrf2), NAD(P)H:quinone oxidoreductase 1 (NQO1) and inflammatory cytokines were also examined. The effect of SAMC on cell viability and apoptosis was examined in cultured human kidney (HK-2) cells. SAMC was confirmed to significantly attenuate cisplatin-induced renal damage by using histological pathology and molecular biological method. Pre-treatment with SAMC reduced NF-κB activity, up-regulated Nrf2 and NQO1 expression and down-regulated inflammatory cytokine levels after cisplatin administration. Cisplatin-induced apoptosis in HK-2 cells was significantly attenuated by SAMC. Thus our results suggest that SAMC could be a potential therapeutic agent in the treatment of the cisplatin-induced nephrotoxicity through its anti-apoptotic, anti-oxidant and anti-inflammatory effects. PMID:28230744

Silibinin Induced Human Glioblastoma Cell Apoptosis Concomitant with Autophagy through Simultaneous Inhibition of mTOR and YAP.

PubMed

Bai, Zhuan-Li; Tay, Vincent; Guo, Shu-Zhong; Ren, Juan; Shu, Mao-Guo

2018-01-01

Silibinin, also known as silybin, is the major flavonolignan isolated from Silybum marianum . Although previous reports demonstrated that silibinin exhibits significant tumor suppressor activities in various cancers by promoting cell apoptosis, it was also shown to trigger autophagy to counteract apoptosis induced by exogenous stresses in several types of cells. However, there is no report to address the role of silibinin induced autophagy in human A172 and SR glioblastoma cells. Our study showed that silibinin treatment not only inhibited the metabolic activities of glioblastoma cells but also promoted their apoptosis through the regulation of caspase 3 and PARP-1 in concentration- and time-dependent manners. Meanwhile, silibinin induced autophagy through upregulation of microtubule-associated protein a light chain 3- (LC3-) II. And autophagy inhibition with chloroquine, a lysosomotropic agent, significantly enhanced silibinin induced glioblastoma cell apoptosis. Moreover, silibinin dose-dependently downregulated the phosphorylation levels of mTOR at Ser-2448, p70S6K at Thr-389, and 4E-BP1 at Thr-37/46. Furthermore, the expression of YAP, the downstream effector of Hippo signal pathway, was also suppressed by silibinin. These results suggested that silibinin induced glioblastoma cell apoptosis concomitant with autophagy which might be due to simultaneous inhibition of mTOR and YAP and silibinin induced autophagy exerted a protective role against cell apoptosis in both A172 and SR cells.

Sugammadex, a Neuromuscular Blockade Reversal Agent, Causes Neuronal Apoptosis in Primary Cultures

PubMed Central

Palanca, José M.; Aguirre-Rueda, Diana; Granell, Manuel V.; Aldasoro, Martin; Garcia, Alma; Iradi, Antonio; Obrador, Elena; Mauricio, Maria Dolores; Vila, Jose; Gil-Bisquert, Anna; Valles, Soraya L.

2013-01-01

Sugammadex, a γ-cyclodextrin that encapsulates selectively steroidal neuromuscular blocking agents, such as rocuronium or vecuronium, has changed the face of clinical neuromuscular pharmacology. Sugammadex allows a rapid reversal of muscle paralysis. Sugammadex appears to be safe and well tolerated. Its blood-brain barrier penetration is poor (< 3% in rats), and thus no relevant central nervous toxicity is expected. However the blood brain barrier permeability can be altered under different conditions (i.e. neurodegenerative diseases, trauma, ischemia, infections, or immature nervous system). Using MTT, confocal microscopy, caspase-3 activity, cholesterol quantification and Western-blot we determine toxicity of Sugammadex in neurons in primary culture. Here we show that clinically relevant sugammadex concentrations cause apoptotic/necrosis neuron death in primary cultures. Studies on the underlying mechanism revealed that sugammadex-induced activation of mitochondria-dependent apoptosis associates with depletion of neuronal cholesterol levels. Furthermore SUG increase CytC, AIF, Smac/Diablo and CASP-3 protein expression in cells in culture. Potential association of SUG-induced alteration in cholesterol homeostasis with oxidative stress and apoptosis activation occurs. Furthermore, resistance/sensitivity to oxidative stress differs between neuronal cell types. PMID:23983586

Concanavalin A: A potential anti-neoplastic agent targeting apoptosis, autophagy and anti-angiogenesis for cancer therapeutics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Wen-wen; Yu, Jia-ying; Xu, Huai-long

2011-10-22

Highlights: {yields} ConA induces cancer cell death targeting apoptosis and autophagy. {yields} ConA inhibits cancer cell angiogenesis. {yields} ConA is utilized in pre-clinical and clinical trials. -- Abstract: Concanavalin A (ConA), a Ca{sup 2+}/Mn{sup 2+}-dependent and mannose/glucose-binding legume lectin, has drawn a rising attention for its remarkable anti-proliferative and anti-tumor activities to a variety of cancer cells. ConA induces programmed cell death via mitochondria-mediated, P73-Foxo1a-Bim apoptosis and BNIP3-mediated mitochondrial autophagy. Through IKK-NF-{kappa}B-COX-2, SHP-2-MEK-1-ERK, and SHP-2-Ras-ERK anti-angiogenic pathways, ConA would inhibit cancer cell survival. In addition, ConA stimulates cell immunity and generates an immune memory, resisting to the same genotypic tumor.more » These biological findings shed light on new perspectives of ConA as a potential anti-neoplastic agent targeting apoptosis, autophagy and anti-angiogenesis in pre-clinical or clinical trials for cancer therapeutics.« less

6-Shogaol induces apoptosis in human leukemia cells through a process involving caspase-mediated cleavage of eIF2α.

PubMed

Liu, Qun; Peng, Yong-Bo; Zhou, Ping; Qi, Lian-Wen; Zhang, Mu; Gao, Ning; Liu, E-Hu; Li, Ping

2013-11-12

6-Shogaol is a promising antitumor agent isolated from dietary ginger (Zingiber officinale). However, little is known about the efficacy of 6-shogaol on leukemia cells. Here we investigated the underlying mechanism of 6-shogaol induced apoptosis in human leukemia cells in vitro and in vivo. Three leukemia cell lines and primary leukemia cells were used to investigate the apoptosis effect of 6-shogaol. A shotgun approach based on label-free proteome with LC-CHIP Q-TOF MS/MS was employed to identify the cellular targets of 6-shogaol and the differentially expressed proteins were analyzed by bioinformatics protocols. The present study indicated that 6-shogaol selectively induced apoptosis in transformed and primary leukemia cells but not in normal cells. Eukaryotic translation initiation factor 2 alpha (eIF2α), a key regulator in apoptosis signaling pathway, was significantly affected in both Jurkat and U937 proteome profiles. The docking results suggested that 6-shogaol might bind well to eIF2α at Ser51 of the N-terminal domain. Immunoblotting data indicated that 6-shogaol induced apoptosis through a process involving dephosphorylation of eIF2α and caspase activation-dependent cleavage of eIF2α. Furthermore, 6-shogaol markedly inhibited tumor growth and induced apoptosis in U937 xenograft mouse model. The potent anti-leukemia activity of 6-shogaol found both in vitro and in vivo in our study make this compound a potential anti-tumor agent for hematologic malignancies.

Valsartan Protects Against Contrast-Induced Acute Kidney Injury in Rats by Inhibiting Endoplasmic Reticulum Stress-Induced Apoptosis.

PubMed

Sun, Yan; Peng, Ping-An; Ma, Yue; Liu, Xiao-Li; Yu, Yi; Jia, Shuo; Xu, Xiao-Han; Wu, Si-Jing; Zhou, Yu-Jie

2017-01-01

Contrast-induced acute kidney injury (CI-AKI) is a serious complication of the administration of iodinated contrast media (CM) for diagnostic and interventional cardiovascular procedures and is associated with substantial morbidity and mortality. While the preventative measures can mitigate the risk of CI-AKI, there remains a need for novel and effective therapeutic approaches. The pathogenesis of CI-AKI is complex and not completely understood. CM-induced renal tubular cell apoptosis caused by the activation of endoplasmic reticulum (ER) stress is involved in CIAKI. We previously demonstrated that valsartan alleviated CM-induced human renal tubular cell apoptosis by inhibiting ER stress in vitro. However, the nephroprotective effect of valsartan on CI-AKI in vivo has not been investigated. Therefore, the aim of this study was to explore the protective effect of valsartan in a rat model of CI-AKI by measuring the amelioration of renal damage and the changes in ER stressrelated biomarkers. Our results showed that the radiocontrast agent meglumine diatrizoate caused significant renal insufficiency, renin-angiotensin system (RAS) activation, and renal tubular apoptosis by triggering ER stress through activation of glucose-regulated protein 78 (GRP78), activating transcription factor 4 (ATF4), caspase 12, CCAAT/enhancer-binding protein-homologous protein (CHOP) and c-Jun N-terminal protein kinase (JNK) (P<0.05; n=6 in each group). Pre-treatment with valsartan significantly alleviated renal dysfunction, pathological injury, and apoptosis along with the inhibition of ER stressrelated biomarkers (P<0.05; n=8 in each group). Valsartan could protect against meglumine diatrizoate-induced kidney injury in rats by inhibiting the ER stress-induced apoptosis, making it a promising strategy for preventing CI-AKI. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

FOXO3-mediated up-regulation of Bim contributes to rhein-induced cancer cell apoptosis.

PubMed

Wang, Jiao; Liu, Shu; Yin, Yancun; Li, Mingjin; Wang, Bo; Yang, Li; Jiang, Yangfu

2015-03-01

The anthraquinone compound rhein is a natural agent in the traditional Chinese medicine rhubarb. Preclinical studies demonstrate that rhein has anticancer activity. Treatment of a variety of cancer cells with rhein may induce apoptosis. Here, we report that rhein induces atypical unfolded protein response in breast cancer MCF-7 cells and hepatoma HepG2 cells. Rhein induces CHOP expression, eIF2α phosphorylation and caspase cleavage, while it does not induce glucose-regulated protein 78 (GRP78) expression in both MCF-7 and HepG2 cells. Meanwhile, rhein inhibits thapsigargin-induced GRP78 expression and X box-binding protein 1 splicing. In addition, rhein inhibits Akt phosphorylation and stimulates FOXO transactivation activity. Rhein induces Bim expression in MCF-7 and HepG2 cells, which can be abrogated by FOXO3a knockdown. Knockdown of FOXO3a or Bim abrogates rhein-induced caspase cleavage and apoptosis. The chemical chaperone 4-phenylbutyrate acid antagonizes the induction of FOXO activation, Bim expression and caspase cleavage by rhein, indicating that protein misfolding may be involved in triggering these deleterious effects. We conclude that FOXO3a-mediated up-regulation of Bim is a key mechanism underlying rhein-induced cancer cells apoptosis.

Curcumin against advanced glycation end products (AGEs) and AGEs-induced detrimental agents.

PubMed

Alizadeh, Mohammad; Kheirouri, Sorayya

2017-11-29

This study was aimed to review and collate effects of curcumin on generation of advanced glycation end products (AGEs) and AGEs induced detrimental agents. Pubmed, Googlescholar, ScienceDirect, and Scopus databases were searched. Searching was not limited to specific publication period. Only English language original articles (in vitro, experimental and human) which had examined the effect of curcumin on AGEs formation and AGEs induced apoptosis, oxidative stress or inflammatory responses were included. To review effect of curcumin on AGEs formation, search terms were as following: ''curcumin" (title) and AGEs or pentosidine or methylglyoxal or carboxymethyllysine or glucosylation (title/abstract). Totally 104 articles were searched which 19 were selected for review. To review effect of curcumin on AGEs induced harmful agents, key words were as following: "curcumin" (title) and AGEs (title/abstract) and apoptosis or oxidative stress or DNA damage or cell injury or inflammatory or cell death or cell proliferation (title/abstract). Totally 126 articles were searched which 18 were found appropriate for review. Regarding curcumin and AGEs formation, ten eligible articles (1 human trial, 5 animal models and 4 in vitro) and with regarding curcumin and AGEs-induced complications, 17 articles (5 on apoptosis, 9 on oxidative stress, and 3 on inflammatory responses) were selected. Except one, all studies indicated that curcumin is able to prevent AGEs formation and AGEs-induced disturbances with different potential mechanisms. Curcumin can inhibit AGEs formation and AGEs-induced disturbances. More RCT researches are suggested to evaluate beneficial effect of curcumin regarding AGEs in different age-related chronic diseases, with specific attention to AGEs memberships.

Csk regulates angiotensin II-induced podocyte apoptosis.

PubMed

Zhang, Lu; Ren, Zhilong; Yang, Qian; Ding, Guohua

2016-07-01

Increasing data have shown that angiotensin II (Ang II) perpetuates podocyte injury and promotes progression to end-stage kidney disease. The mechanism underlying Ang II-induced podocyte apoptosis has not been established. C-terminal Src kinase (Csk) is a cytoplasmic kinase that interacts with scaffolding proteins involved in cell growth, adhesion, and polarization, and the role of Csk in regulating cellular apoptosis has gradually attracted attention. This study evaluates the role of Csk in Ang II-induced podocyte apoptosis. In vivo, Wistar rats were randomly subjected to a normal saline or Ang II infusion. In vitro, we exposed differentiated mouse podocytes to Ang II. Ang II increased Csk expression and induced podocyte apoptosis, stimulated Csk translocation and binding to Caveolin-1, and stimulated decreased Fyn pY416, increased Fyn pY529, and nephrin dephosphorylation. Csk knockdown prevented Ang II-induced podocyte apoptosis, reduced Fyn kinase inactivation, and increased the interaction between nephrin and the activated form of Fyn, accompanied by a reduced interaction between Csk and Caveolin-1. These findings indicate that Ang II induces podocyte injury via a Csk-dependent pathway.

Research Advances on Pathways of Nickel-Induced Apoptosis

PubMed Central

Guo, Hongrui; Chen, Lian; Cui, Hengmin; Peng, Xi; Fang, Jing; Zuo, Zhicai; Deng, Junliang; Wang, Xun; Wu, Bangyuan

2015-01-01

High concentrations of nickel (Ni) are harmful to humans and animals. Ni targets a number of organs and produces multiple toxic effects. Apoptosis is important in Ni-induced toxicity of the kidneys, liver, nerves, and immune system. Apoptotic pathways mediated by reactive oxygen species (ROS), mitochondria, endoplasmic reticulum (ER), Fas, and c-Myc participate in Ni-induced cell apoptosis. However, the exact mechanism of apoptosis caused by Ni is still unclear. Understanding the mechanism of Ni-induced apoptosis may help in designing measures to prevent Ni toxicity. PMID:26703593

3-Bromopyruvate induces apoptosis in breast cancer cells by downregulating Mcl-1 through the PI3K/Akt signaling pathway.

PubMed

Liu, Zhe; Zhang, Yuan-Yuan; Zhang, Qian-Wen; Zhao, Su-Rong; Wu, Cheng-Zhu; Cheng, Xiu; Jiang, Chen-Chen; Jiang, Zhi-Wen; Liu, Hao

2014-04-01

The hexokinase inhibitor 3-bromopyruvate (3-BrPA) can inhibit glycolysis in tumor cells to reduce ATP production, resulting in apoptosis. However, as 3-BrPA is an alkylating agent, its cytotoxic action may be induced by other molecular mechanisms. The results presented here reveal that 3-BrPA-induced apoptosis is caspase independent. Further, 3-BrPA induces the generation of reactive oxygen species in MDA-MB-231 cells, leading to mitochondria-mediated apoptosis. These results suggest that caspase-independent apoptosis may be induced by the generation of reactive oxygen species. In this study, we also demonstrated that 3-BrPA induces apoptosis through the downregulation of myeloid cell leukemia-1 (Mcl-1) in MDA-MB-231 breast cancer cells. The results of Mcl-1 knockdown indicate that Mcl-1 plays an important role in 3-BrPA-induced apoptosis. Further, the upregulation of Mcl-1 expression in 3-BrPA-treated MDA-MB-231 cells significantly increases cell viability. In addition, 3-BrPA treatment resulted in the downregulation of p-Akt, suggesting that 3-BrPA may downregulate Mcl-1 through the phosphoinositide-3-kinase/Akt pathway. These findings indicate that 3-BrPA induces apoptosis in breast cancer cells by downregulating Mcl-1 through the phosphoinositide-3-kinase/Akt signaling pathway.

Time course of Paclitaxel-induced apoptosis in an experimental model of virus-induced breast cancer.

PubMed

Erba, Paola A; Manfredi, Chiara; Lazzeri, Elena; Minichilli, Fabrizio; Pauwels, Ernest K J; Sbrana, Alberto; Strauss, H William; Mariani, Giuliano

2010-05-01

Early assessment of the efficacy of treatment is important in patients with breast cancer, whose routine adjuvant regimen frequently includes chemotherapy. Irrespective of the exact mechanisms involved in induction, the common early phenotypic marker of apoptosis is the expression on the outer cell membrane surface of phosphatidylserine, which avidly binds annexin V. (99m)Tc-labeled annexin V has been proposed for in vivo scintigraphic detection of apoptosis, albeit with contradicting results. This study was performed to define the time course of apoptosis induced by the chemotherapeutic agent paclitaxel in a model of virus-induced murine breast cancer. The RIII virus induces an estrogen-dependent, slow-growing breast cancer; BALB-c/cRIII female mice with breast tumors averaging 10 mm were studied, both in baseline conditions and at various times after the intravenous administration of paclitaxel (equivalent to a human dose of 20 mg/70 kg of body weight). The biodistribution of (99m)Tc-annexin V was evaluated at baseline and then at 1, 3, 6, and 24 h after paclitaxel administration. Apoptotic and antiapoptotic markers were also evaluated in tumor samples obtained at the same time points: DNA breaks (terminal deoxynucleotidyl transferase biotin-dUTP nick-end labeling [TUNEL]), active caspase-3, apoptosis-inducing factor, and Bcl-2 protein. Baseline uptake of (99m)Tc-annexin V in breast tumors was about 2-fold higher than the uptake in normal breast tissue (demonstrating some ongoing apoptosis); tracer uptake increased at 1 and 3 h after paclitaxel administration (to almost double the baseline value) and then declined to levels even lower than baseline. Although no activation of the apoptosis-inducing factor mechanism was detected, a peak in TUNEL-positive tumor cells was reached 3 h after paclitaxel administration (to more than 6-fold the baseline level). The antiapoptotic marker Bcl-2 exhibited a biphasic pattern, with a maximum drop at 3 h, followed by return

Visualizing Vpr-Induced G2 Arrest and Apoptosis

PubMed Central

Murakami, Tomoyuki; Aida, Yoko

2014-01-01

Vpr is an accessory protein of human immunodeficiency virus type 1 (HIV-1) with multiple functions. The induction of G2 arrest by Vpr plays a particularly important role in efficient viral replication because the transcriptional activity of the HIV-1 long terminal repeat is most active in G2 phase. The regulation of apoptosis by Vpr is also important for immune suppression and pathogenesis during HIV infection. However, it is not known whether Vpr-induced apoptosis depends on the ability of Vpr to induce G2 arrest, and the dynamics of Vpr-induced G2 arrest and apoptosis have not been visualized. We performed time-lapse imaging to examine the temporal relationship between Vpr-induced G2 arrest and apoptosis using HeLa cells containing the fluorescent ubiquitination-based cell cycle indicator2 (Fucci2). The dynamics of G2 arrest and subsequent long-term mitotic cell rounding in cells transfected with the Vpr-expression vector were visualized. These cells underwent nuclear mis-segregation after prolonged mitotic processes and then entered G1 phase. Some cells subsequently displayed evidence of apoptosis after prolonged mitotic processes and nuclear mis-segregation. Interestingly, Vpr-induced apoptosis was seldom observed in S or G2 phase. Likewise, visualization of synchronized HeLa/Fucci2 cells infected with an adenoviral vector expressing Vpr clearly showed that Vpr arrests the cell cycle at G2 phase, but does not induce apoptosis at S or G2 phase. Furthermore, time-lapse imaging of HeLa/Fucci2 cells expressing SCAT3.1, a caspase-3-sensitive fusion protein, clearly demonstrated that Vpr induces caspase-3-dependent apoptosis. Finally, to examine whether the effects of Vpr on G2 arrest and apoptosis were reversible, we performed live-cell imaging of a destabilizing domain fusion Vpr, which enabled rapid stabilization and destabilization by Shield1. The effects of Vpr on G2 arrest and subsequent apoptosis were reversible. This study is the first to characterize the

Identification of 6-methylsulfinylhexyl isothiocyanate as an apoptosis-inducing component in wasabi.

PubMed

Watanabe, Makoto; Ohata, Masahiko; Hayakawa, Sumio; Isemura, Mamoru; Kumazawa, Shigenori; Nakayama, Tsutomu; Furugori, Michiyo; Kinae, Naohide

2003-03-01

The ethanol extract from Japanese horseradish wasabi was found to inhibit cell proliferation in human monoblastic leukemia U937 cells by inducing apoptotic cell death. Separation by methods including silica gel chromatography and preparative HPLC gave an active compound, which was identified as 6-methylsulfinylhexyl isothiocyanate (6-HITC). Several lines of evidence indicated that 6-HITC induced apoptosis in U937 cells and human stomach cancer MKN45 cells. Thus, 6-HITC is potentially useful as a natural anti-cancer agent.

Chk2 mediates RITA-induced apoptosis

PubMed Central

de Lange, J; Verlaan-de Vries, M; Teunisse, A F A S; Jochemsen, A G

2012-01-01

Reactivation of the p53 tumor-suppressor protein by small molecules like Nutlin-3 and RITA (reactivation of p53 and induction of tumor cell apoptosis) is a promising strategy for cancer therapy. The molecular mechanisms involved in the responses to RITA remain enigmatic. Several groups reported the induction of a p53-dependent DNA damage response. Furthermore, the existence of a p53-dependent S-phase checkpoint has been suggested, involving the checkpoint kinase Chk1. We have recently shown synergistic induction of apoptosis by RITA in combination with Nutlin-3, and we observed concomitant Chk2 phosphorylation. Therefore, we investigated whether Chk2 contributes to the cellular responses to RITA. Strikingly, the induction of apoptosis seemed entirely Chk2 dependent. Transcriptional activity of p53 in response to RITA required the presence of Chk2. A partial rescue of apoptosis observed in Noxa knockdown cells emphasized the relevance of p53 transcriptional activity for RITA-induced apoptosis. In addition, we observed an early p53- and Chk2-dependent block of DNA replication upon RITA treatment. Replicating cells seemed more prone to entering RITA-induced apoptosis. Furthermore, the RITA-induced DNA damage response, which was not a secondary effect of apoptosis induction, was strongly attenuated in cells lacking p53 or Chk2. In conclusion, we identified Chk2 as an essential mediator of the cellular responses to RITA. PMID:22158418

The organophosphate insecticide chlorpyrifos confers its genotoxic effects by inducing DNA damage and cell apoptosis.

PubMed

Li, Diqiu; Huang, Qingchun; Lu, Miaoqing; Zhang, Lei; Yang, Zhichuan; Zong, Mimi; Tao, Liming

2015-09-01

The organophosphate insecticide chlorpyrifos (CPF) is known to induce neurological effects, malformation and micronucleus formation, persistent developmental disorders, and maternal toxicity in rats and mice. The binding of chlorpyrifos with DNA to produce DNA adducts leads to an increasing social concern about the genotoxic risk of CPF in human, but CPF-induced cytotoxicity through DNA damage and cell apoptosis is not well understood. Here, we quantified the cytotoxicity and potential genotoxicity of CPF using the alkaline comet assay, γH2AX foci formation, and the DNA laddering assay in order to detect DNA damage and apoptosis in human HeLa and HEK293 cells in vitro. Drosophila S2 cells were used as a positive control. The alkaline comet assay showed that sublethal concentrations of CPF induced significant concentration-dependent increases in single-strand DNA breaks in the treated cells compared with the control. The percentage of γH2AX-positive HeLa cells revealed that CPF also causes DNA double-strand breaks in a time-dependent manner. Moreover, DNA fragmentation analysis demonstrated that exposure to CPF induced a significant concentration- and time-dependent increase in cell apoptosis. We conclude that CPF is a strongly genotoxic agent that induces DNA damage and cell apoptosis. Copyright © 2015 Elsevier Ltd. All rights reserved.

Noscapine induces mitochondria-mediated apoptosis in human colon cancer cells in vivo and in vitro

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Zi-Rong; Liu, Meng; Peng, Xiu-Lan

2012-05-11

Highlights: Black-Right-Pointing-Pointer Noscapine inhibited cell viability of colon cancer in a time- and dose- dependent manner. Black-Right-Pointing-Pointer G{sub 2}/M phase arrest and chromatin condensation and nuclear fragmentation were induced. Black-Right-Pointing-Pointer Noscapine promoted apoptosis via mitochondrial pathways. Black-Right-Pointing-Pointer Tumorigenicity was inhibited by noscapine. -- Abstract: Noscapine, a phthalide isoquinoline alkaloid derived from opium, has been widely used as a cough suppressant for decades. Noscapine has recently been shown to potentiate the anti-cancer effects of several therapies by inducing apoptosis in various malignant cells without any detectable toxicity in cells or tissues. However, the mechanism by which noscapine induces apoptosis in colonmore » cancer cells remains unclear. The signaling pathways by which noscapine induces apoptosis were investigated in colon cancer cell lines treated with various noscapine concentrations for 72 h, and a dose-dependent inhibition of cell viability was observed. Noscapine effectively inhibited the proliferation of LoVo cells in vitro (IC{sub 50} = 75 {mu}M). This cytotoxicity was reflected by cell cycle arrest at G{sub 2}/M and subsequent apoptosis, as indicated by increased chromatin condensation and fragmentation, the upregulation of Bax and cytochrome c (Cyt-c), the downregulation of survivin and Bcl-2, and the activation of caspase-3 and caspase-9. Moreover, in a xenograft tumor model in mice, noscapine injection clearly inhibited tumor growth via the induction of apoptosis, which was demonstrated using a TUNEL assay. These results suggest that noscapine induces apoptosis in colon cancer cells via mitochondrial pathways. Noscapine may be a safe and effective chemotherapeutic agent for the treatment of human colon cancer.« less

2-aryl benzimidazole conjugate induced apoptosis in human breast cancer MCF-7 cells through caspase independent pathway.

PubMed

Nayak, V Lakshma; Nagesh, Narayana; Ravikumar, A; Bagul, Chandrakant; Vishnuvardhan, M V P S; Srinivasulu, Vunnam; Kamal, Ahmed

2017-01-01

Apoptosis is a representative form of programmed cell death, which has been assumed to be critical for cancer prevention. Thus, any agent that can induce apoptosis may be useful for cancer treatment and apoptosis induction is arguably the most potent defense against cancer promotion. In our previous studies, 2-aryl benzimidazole conjugates were synthesized and evaluated for their antiproliferative activity and one of the new molecule (2f) was considered as a potential lead. This lead molecule showed significant antiproliferative activity against human breast cancer cell line, MCF-7. The results of the present study revealed that this compound arrested the cell cycle at G2/M phase. Topoisomerase II inhibition assay and Western blot analysis suggested that this compound effectively inhibits topoisomerase II activity which leads to apoptotic cell death. Apoptosis induction in MCF-7 cells was further confirmed by loss of mitochondrial membrane potential (∆Ψm), release of cytochrome c from mitochondria, an increase in the level of apoptosis inducing factor (AIF), generation of reactive oxygen species (ROS), up regulation of proapoptotic protein Bax and down regulation of anti apoptotic protein Bcl-2. Apoptosis assay using Annexin V-FITC assay also suggested that this compound induced cell death by apoptosis. However, compound 2f induced apoptosis could not be reversed by Z-VAD-FMK (a pan-caspase inhibitor) demonstrated that the 2f induced apoptosis was caspase independent. Further, 2f treatment did not activate caspase-7 and caspase-9 activity, suggesting that this compound induced apoptosis in breast cancer cells via a caspase independent pathway. Most importantly, this compound was less toxic towards non-tumorigenic breast epithelial cells, MCF-10A. Furthermore, docking studies also support the potentiality of this molecule to bind to the DNA topoisomerase II.

The Marine Fungal Metabolite, Dicitrinone B, Induces A375 Cell Apoptosis through the ROS-Related Caspase Pathway

PubMed Central

Chen, Li; Gong, Mei-Wei; Peng, Zhen-Fei; Zhou, Tong; Ying, Min-Gang; Zheng, Qiu-Hong; Liu, Qin-Ying; Zhang, Qi-Qing

2014-01-01

Dicitrinone B, a rare carbon-bridged citrinin dimer, was isolated from the marine-derived fungus, Penicillium citrinum. It was reported to have antitumor effects on tumor cells previously; however, the details of the mechanism remain unclear. In this study, we found that dicitrinone B inhibited the proliferation of multiple tumor types. Among them, the human malignant melanoma cell, A375, was confirmed to be the most sensitive. Morphologic evaluation, cell cycle arrest and apoptosis rate analysis results showed that dicitrinone B significantly induced A375 cell apoptosis. Subsequent observation of reactive oxygen species (ROS) accumulation and mitochondrial membrane potential (MMP) reduction revealed that the apoptosis induced by dicitrinone B may be triggered by over-producing ROS. Further studies indicated that the apoptosis was associated with both intrinsic and extrinsic apoptosis pathways under the regulation of Bcl-2 family proteins. Caspase-9, caspase-8 and caspase-3 were activated during the process, leading to PARP cleavage. The pan-caspase inhibitor, Z-VAD-FMK, could reverse dicitrinone B-induced apoptosis, suggesting that it is a caspase-dependent pathway. Our data for the first time showed that dicitrinone B inhibits the proliferation of tumor cells by inducing cell apoptosis. Moreover, compared with the first-line chemotherapy drug, 5-fluorouracil (5-Fu), dicitrinone B showed much more potent anticancer efficacy, suggesting that it might serve as a potential antitumor agent. PMID:24699111

Detergent sclerosants at sub-lytic concentrations induce endothelial cell apoptosis through a caspase dependent pathway.

PubMed

Cooley-Andrade, Osvaldo; Cheung, Kelvin; Chew, An-Ning; Connor, David Ewan; Parsi, Kurosh

2016-07-01

To investigate the apoptotic effects of detergent sclerosants sodium tetradecylsulphate (STS) and polidocanol (POL) on endothelial cells at sub-lytic concentrations. Human umbilical vein endothelial cells (HUVECs) were isolated and labelled with antibodies to assess for apoptosis and examined with confocal microscopy and flow cytometry. Isolated HUVECs viability was assessed using propidium iodide staining. Early apoptosis was determined by increased phosphatidylserine exposure by lactadherin binding. Caspase 3, 8, 9 and Bax activation as well as inhibitory assays with Pan Caspase (Z-VAD-FMK) and Bax (BI-6C9) were assessed to identify apoptotic pathways. Porimin activation was used to assess cell membrane permeability. Cell lysis reached almost 100 % with STS at 0.3 % and with POL at 0.6 %. Apoptosis was seen with both STS and POL at concentrations ranging from 0.075 to 0.15 %. PS exposure increased with both STS and POL and exhibited a dose-dependent trend. Active Caspase 3, 8 and 9 but not Bax were increased in HUVECs stimulated with low concentrations of both STS and POL. Inhibitory assays demonstrated Caspase 3, 8, 9 inhibition at low concentrations (0.075 to 0.6 %) with both STS and POL. Both agents increased the activation of porimin at all concentrations. Both sclerosants induced endothelial cell (EC) apoptosis at sub-lytic concentrations through a caspase-dependant pathway. Both agents induced EC oncosis.

Biguanides sensitize leukemia cells to ABT-737-induced apoptosis by inhibiting mitochondrial electron transport

PubMed Central

Velez, Juliana; Pan, Rongqing; Lee, Jason T.C.; Enciso, Leonardo; Suarez, Marta; Duque, Jorge Eduardo; Jaramillo, Daniel; Lopez, Catalina; Morales, Ludis; Bornmann, William; Konopleva, Marina; Krystal, Gerald; Andreeff, Michael; Samudio, Ismael

2016-01-01

Metformin displays antileukemic effects partly due to activation of AMPK and subsequent inhibition of mTOR signaling. Nevertheless, Metformin also inhibits mitochondrial electron transport at complex I in an AMPK-independent manner, Here we report that Metformin and rotenone inhibit mitochondrial electron transport and increase triglyceride levels in leukemia cell lines, suggesting impairment of fatty acid oxidation (FAO). We also report that, like other FAO inhibitors, both agents and the related biguanide, Phenformin, increase sensitivity to apoptosis induction by the bcl-2 inhibitor ABT-737 supporting the notion that electron transport antagonizes activation of the intrinsic apoptosis pathway in leukemia cells. Both biguanides and rotenone induce superoxide generation in leukemia cells, indicating that oxidative damage may sensitize toABT-737 induced apoptosis. In addition, we demonstrate that Metformin sensitizes leukemia cells to the oligomerization of Bak, suggesting that the observed synergy with ABT-737 is mediated, at least in part, by enhanced outer mitochondrial membrane permeabilization. Notably, Phenformin was at least 10-fold more potent than Metformin in abrogating electron transport and increasing sensitivity to ABT-737, suggesting that this agent may be better suited for targeting hematological malignancies. Taken together, our results suggest that inhibition of mitochondrial metabolism by Metformin or Phenformin is associated with increased leukemia cell susceptibility to induction of intrinsic apoptosis, and provide a rationale for clinical studies exploring the efficacy of combining biguanides with the orally bioavailable derivative of ABT-737, Venetoclax. PMID:27283492

Biguanides sensitize leukemia cells to ABT-737-induced apoptosis by inhibiting mitochondrial electron transport.

PubMed

Velez, Juliana; Pan, Rongqing; Lee, Jason T C; Enciso, Leonardo; Suarez, Marta; Duque, Jorge Eduardo; Jaramillo, Daniel; Lopez, Catalina; Morales, Ludis; Bornmann, William; Konopleva, Marina; Krystal, Gerald; Andreeff, Michael; Samudio, Ismael

2016-08-09

Metformin displays antileukemic effects partly due to activation of AMPK and subsequent inhibition of mTOR signaling. Nevertheless, Metformin also inhibits mitochondrial electron transport at complex I in an AMPK-independent manner, Here we report that Metformin and rotenone inhibit mitochondrial electron transport and increase triglyceride levels in leukemia cell lines, suggesting impairment of fatty acid oxidation (FAO). We also report that, like other FAO inhibitors, both agents and the related biguanide, Phenformin, increase sensitivity to apoptosis induction by the bcl-2 inhibitor ABT-737 supporting the notion that electron transport antagonizes activation of the intrinsic apoptosis pathway in leukemia cells. Both biguanides and rotenone induce superoxide generation in leukemia cells, indicating that oxidative damage may sensitize toABT-737 induced apoptosis. In addition, we demonstrate that Metformin sensitizes leukemia cells to the oligomerization of Bak, suggesting that the observed synergy with ABT-737 is mediated, at least in part, by enhanced outer mitochondrial membrane permeabilization. Notably, Phenformin was at least 10-fold more potent than Metformin in abrogating electron transport and increasing sensitivity to ABT-737, suggesting that this agent may be better suited for targeting hematological malignancies. Taken together, our results suggest that inhibition of mitochondrial metabolism by Metformin or Phenformin is associated with increased leukemia cell susceptibility to induction of intrinsic apoptosis, and provide a rationale for clinical studies exploring the efficacy of combining biguanides with the orally bioavailable derivative of ABT-737, Venetoclax.

ATP depletion inhibits glucocorticoid-induced thymocyte apoptosis.

PubMed Central

Stefanelli, C; Bonavita, F; Stanic', I; Farruggia, G; Falcieri, E; Robuffo, I; Pignatti, C; Muscari, C; Rossoni, C; Guarnieri, C; Caldarera, C M

1997-01-01

In quiescent thymocytes, mitochondrial de-energization was not correlated to apoptotic death. In fact, thymocytes treated with oligomycin, a highly specific inhibitor of ATP synthase, alone or with atractyloside to block ATP translocation from the cytoplasm, were alive, even if their mitochondria were depolarized, as revealed by flow cytometry after Rhodamine 123 staining. Furthermore, oligomycin was a powerful inhibitor of apoptosis induced in rat thymocytes by dexamethasone and, to a lesser extent, by the calcium ionophore A23187 and etoposide, but was without effect when apoptosis was induced by staurosporine, and increased cell death in mitogen-treated thymocytes. The inhibition of apoptosis was confirmed by morphological criteria, inhibition of inter-nucleosomal DNA fragmentation and inhibition of the loss of membrane integrity. The anti-apoptotic effect of oligomycin in cells treated with A23187 or etoposide was correlated to the inhibition of protein synthesis, while inhibition of apoptosis induced by dexamethasone, already evident at an oligomycin concentration of 10 ng/ml, was instead strictly correlated to the effect exerted on the cellular ATP level. Thymocyte apoptosis triggered by dexamethasone was blocked or delayed by inhibitors of respiratory-chain uncouplers, inhibitors of ATP synthase and antioxidants: a lasting protection from dexamethasone-induced apoptosis was always correlated to a drastic and rapid reduction in ATP level (31-35% of control), while a delay in the death process was characterized by a moderate decrease in ATP (73-82% of control). Oligomycin inhibited the specific binding of radioactive corticosteroid to thymocyte nuclei, confirming the inhibitory effect of ATP depletion on glucocorticoid binding and suggesting that ATP depletion is a common mediator of the anti-apoptotic action of different effectors in glucocorticoid-induced apoptosis. In conclusion, the reported data indicate that ATP may act as a cellular modulator of some

Mequindox-Induced Kidney Toxicity Is Associated With Oxidative Stress and Apoptosis in the Mouse.

PubMed

Liu, Qianying; Lei, Zhixin; Guo, Jingchao; Liu, Aimei; Lu, Qirong; Fatima, Zainab; Khaliq, Haseeb; Shabbir, Muhammad A B; Maan, Muhammad Kashif; Wu, Qinghua; Dai, Menghong; Wang, Xu; Pan, Yuanhu; Yuan, Zonghui

2018-01-01

Mequindox (MEQ), belonging to quinoxaline-di- N -oxides (QdNOs), is a synthetic antimicrobial agent widely used in China. Previous studies found that the kidney was one of the main toxic target organs of the QdNOs. However, the mechanisms underlying the kidney toxicity caused by QdNOs in vivo still remains unclear. The present study aimed to explore the molecular mechanism of kidney toxicity in mice after chronic exposure to MEQ. MEQ led to the oxidative stress, apoptosis, and mitochondrial damage in the kidney of mice. Meanwhile, MEQ upregulated Bax/Bcl-2 ratio, disrupted mitochondrial permeability transition pores, caused cytochrome c release, and a cascade activation of caspase, eventually induced apoptosis. The oxidative stress mediated by MEQ might led to mitochondria damage and apoptosis in a mitochondrial-dependent apoptotic pathway. Furthermore, upregulation of the Nrf2-Keap1 signaling pathway was also observed. Our findings revealed that the oxidative stress, mitochondrial dysfunction, and the Nrf2-Keap1 signaling pathway were associated with the kidney apoptosis induced by MEQ in vivo .

Mequindox-Induced Kidney Toxicity Is Associated With Oxidative Stress and Apoptosis in the Mouse

PubMed Central

Liu, Qianying; Lei, Zhixin; Guo, Jingchao; Liu, Aimei; Lu, Qirong; Fatima, Zainab; Khaliq, Haseeb; Shabbir, Muhammad A. B.; Maan, Muhammad Kashif; Wu, Qinghua; Dai, Menghong; Wang, Xu; Pan, Yuanhu; Yuan, Zonghui

2018-01-01

Mequindox (MEQ), belonging to quinoxaline-di-N-oxides (QdNOs), is a synthetic antimicrobial agent widely used in China. Previous studies found that the kidney was one of the main toxic target organs of the QdNOs. However, the mechanisms underlying the kidney toxicity caused by QdNOs in vivo still remains unclear. The present study aimed to explore the molecular mechanism of kidney toxicity in mice after chronic exposure to MEQ. MEQ led to the oxidative stress, apoptosis, and mitochondrial damage in the kidney of mice. Meanwhile, MEQ upregulated Bax/Bcl-2 ratio, disrupted mitochondrial permeability transition pores, caused cytochrome c release, and a cascade activation of caspase, eventually induced apoptosis. The oxidative stress mediated by MEQ might led to mitochondria damage and apoptosis in a mitochondrial-dependent apoptotic pathway. Furthermore, upregulation of the Nrf2-Keap1 signaling pathway was also observed. Our findings revealed that the oxidative stress, mitochondrial dysfunction, and the Nrf2-Keap1 signaling pathway were associated with the kidney apoptosis induced by MEQ in vivo. PMID:29765325

Isogambogenic acid induces apoptosis-independent autophagic cell death in human non-small-cell lung carcinoma cells.

PubMed

Yang, Jianhong; Zhou, Yongzhao; Cheng, Xia; Fan, Yi; He, Shichao; Li, Shucai; Ye, Haoyu; Xie, Caifeng; Wu, Wenshuang; Li, Chunyan; Pei, Heying; Li, Luyuan; Wei, Zhe; Peng, Aihua; Wei, Yuquan; Li, Weimin; Chen, Lijuan

2015-01-09

To overcome drug resistance caused by apoptosis deficiency in patients with non-small cell lung carcinoma (NSCLC), there is a need to identify other means of triggering apoptosis-independent cancer cell death. We are the first to report that isogambogenic acid (iso-GNA) can induce apoptosis-independent autophagic cell death in human NSCLC cells. Several features of the iso-GNA-treated NSCLC cells indicated that iso-GNA induced autophagic cell death. First, there was no evidence of apoptosis or cleaved caspase 3 accumulation and activation. Second, iso-GNA treatment induced the formation of autophagic vacuoles, increased LC3 conversion, caused the appearance of autophagosomes and increased the expression of autophagy-related proteins. These findings provide evidence that iso-GNA induces autophagy in NSCLC cells. Third, iso-GNA-induced cell death was inhibited by autophagic inhibitors or by selective ablation of Atg7 and Beclin 1 genes. Furthermore, the mTOR inhibitor rapamycin increased iso-GNA-induced cell death by enhancing autophagy. Finally, a xenograft model provided additional evidence that iso-GNA exhibited anticancer effect through inducing autophagy-dependent cell death in NSCLC cells. Taken together, our results demonstrated that iso-GNA exhibited an anticancer effect by inducing autophagy-dependent cell death in NSCLC cells, which may be an effective chemotherapeutic agent that can be used against NSCLC in a clinical setting.

Isogambogenic acid induces apoptosis-independent autophagic cell death in human non-small-cell lung carcinoma cells

PubMed Central

Yang, Jianhong; Zhou, Yongzhao; Cheng, Xia; Fan, Yi; He, Shichao; Li, Shucai; Ye, Haoyu; Xie, Caifeng; Wu, Wenshuang; Li, Chunyan; Pei, Heying; Li, Luyuan; Wei, Zhe; Peng, Aihua; Wei, Yuquan; Li, Weimin; Chen, Lijuan

2015-01-01

To overcome drug resistance caused by apoptosis deficiency in patients with non-small cell lung carcinoma (NSCLC), there is a need to identify other means of triggering apoptosis-independent cancer cell death. We are the first to report that isogambogenic acid (iso-GNA) can induce apoptosis-independent autophagic cell death in human NSCLC cells. Several features of the iso-GNA-treated NSCLC cells indicated that iso-GNA induced autophagic cell death. First, there was no evidence of apoptosis or cleaved caspase 3 accumulation and activation. Second, iso-GNA treatment induced the formation of autophagic vacuoles, increased LC3 conversion, caused the appearance of autophagosomes and increased the expression of autophagy-related proteins. These findings provide evidence that iso-GNA induces autophagy in NSCLC cells. Third, iso-GNA-induced cell death was inhibited by autophagic inhibitors or by selective ablation of Atg7 and Beclin 1 genes. Furthermore, the mTOR inhibitor rapamycin increased iso-GNA-induced cell death by enhancing autophagy. Finally, a xenograft model provided additional evidence that iso-GNA exhibited anticancer effect through inducing autophagy-dependent cell death in NSCLC cells. Taken together, our results demonstrated that iso-GNA exhibited an anticancer effect by inducing autophagy-dependent cell death in NSCLC cells, which may be an effective chemotherapeutic agent that can be used against NSCLC in a clinical setting. PMID:25571970

Alkylating agent induced NRF2 blocks endoplasmic reticulum stress-mediated apoptosis via control of glutathione pools and protein thiol homeostasis

PubMed Central

Zanotto-Filho, Alfeu; Masamsetti, V. Pragathi; Loranc, Eva; Tonapi, Sonal S.; Gorthi, Aparna; Bernard, Xavier; Gonçalves, Rosângela Mayer; Moreira, José C. F.; Chen, Yidong; Bishop, Alexander J. R.

2016-01-01

Alkylating agents are a commonly used cytotoxic class of anticancer drugs. Understanding the mechanisms whereby cells respond to these drugs is key to identify means to improve therapy while reducing toxicity. By integrating genome-wide gene expression profiling, protein analysis and functional cell validation, we herein demonstrated a direct relationship between NRF2 and Endoplasmic Reticulum (ER) stress pathways in response to alkylating agents, which is coordinated by the availability of glutathione (GSH) pools. GSH is essential for both drug detoxification and protein thiol homeostasis within the ER, thus inhibiting ER stress induction and promoting survival; an effect independent of its antioxidant role. NRF2 accumulation induced by alkylating agents resulted in increased GSH synthesis via GCLC/GCLM enzyme, and interfering with this NRF2 response by either NRF2 knockdown or GCLC/GCLM inhibition with buthionine sulfoximine (BSO) caused accumulation of damaged proteins within the ER, leading to PERK-dependent apoptosis. Conversely, upregulation of NRF2, through KEAP1 depletion or NRF2-myc overexpression, or increasing GSH levels with N-acetylcysteine (NAC) or glutathione-ethyl-ester (GSH-E), decreased ER stress and abrogated alkylating agents-induced cell death. Based on these results, we identified a subset of lung and head-and-neck carcinomas with mutations in either KEAP1 or NRF2/NFE2L2 genes that correlate with NRF2 targets overexpression and poor survival. In KEAP1 mutant cancer cells, NRF2 knockdown and GSH depletion increased cell sensitivity via ER stress induction in a mechanism specific to alkylating drugs. Overall, we show that the NRF2-GSH influence on ER homeostasis implicates defects in NRF2-GSH or ER stress machineries as affecting alkylating therapy toxicity. PMID:27638861

Alkylating Agent-Induced NRF2 Blocks Endoplasmic Reticulum Stress-Mediated Apoptosis via Control of Glutathione Pools and Protein Thiol Homeostasis.

PubMed

Zanotto-Filho, Alfeu; Masamsetti, V Pragathi; Loranc, Eva; Tonapi, Sonal S; Gorthi, Aparna; Bernard, Xavier; Gonçalves, Rosângela Mayer; Moreira, José C F; Chen, Yidong; Bishop, Alexander J R

2016-12-01

Alkylating agents are a commonly used cytotoxic class of anticancer drugs. Understanding the mechanisms whereby cells respond to these drugs is key to identify means to improve therapy while reducing toxicity. By integrating genome-wide gene expression profiling, protein analysis, and functional cell validation, we herein demonstrated a direct relationship between NRF2 and Endoplasmic Reticulum (ER) stress pathways in response to alkylating agents, which is coordinated by the availability of glutathione (GSH) pools. GSH is essential for both drug detoxification and protein thiol homeostasis within the ER, thus inhibiting ER stress induction and promoting survival, an effect independent of its antioxidant role. NRF2 accumulation induced by alkylating agents resulted in increased GSH synthesis via GCLC/GCLM enzyme, and interfering with this NRF2 response by either NRF2 knockdown or GCLC/GCLM inhibition with buthionine sulfoximine caused accumulation of damaged proteins within the ER, leading to PERK-dependent apoptosis. Conversely, upregulation of NRF2, through KEAP1 depletion or NRF2-myc overexpression, or increasing GSH levels with N-acetylcysteine or glutathione-ethyl-ester, decreased ER stress and abrogated alkylating agents-induced cell death. Based on these results, we identified a subset of lung and head-and-neck carcinomas with mutations in either KEAP1 or NRF2/NFE2L2 genes that correlate with NRF2 target overexpression and poor survival. In KEAP1-mutant cancer cells, NRF2 knockdown and GSH depletion increased cell sensitivity via ER stress induction in a mechanism specific to alkylating drugs. Overall, we show that the NRF2-GSH influence on ER homeostasis implicates defects in NRF2-GSH or ER stress machineries as affecting alkylating therapy toxicity. Mol Cancer Ther; 15(12); 3000-14. ©2016 AACR. ©2016 American Association for Cancer Research.

Nicotine Induces Podocyte Apoptosis through Increasing Oxidative Stress

PubMed Central

Lan, Xiqian; Lederman, Rivka; Eng, Judith M.; Shoshtari, Seyedeh Shadafarin Marashi; Saleem, Moin A.; Malhotra, Ashwani; Singhal, Pravin C.

2016-01-01

Background Cigarette smoking plays an important role in the progression of chronic kidney disease (CKD). Nicotine, one of the major components of cigarette smoking, has been demonstrated to increase proliferation of renal mesangial cells. In this study, we examined the effect of nicotine on podocyte injury. Methods To determine the expression of nicotinic acetylcholine receptors (nAChR subunits) in podocytes, cDNAs and cell lysate of cultured human podocytes were used for the expression of nAChR mRNAs and proteins, respectively; and mouse renal cortical sections were subjected to immunofluorescant staining. We also studied the effect of nicotine on podocyte nephrin expression, reactive oxygen species (ROS) generation (via DCFDA loading followed by fluorometric analysis), proliferation, and apoptosis (morphologic assays). We evaluated the effect of nicotine on podocyte downstream signaling including phosphorylation of ERK1/2, JNK, and p38 and established causal relationships by using respective inhibitors. We used nAChR antagonists to confirm the role of nicotine on podocyte injury. Results Human podocytes displayed robust mRNA and protein expression of nAChR in vitro studies. In vivo studies, mice renal cortical sections revealed co-localization of nAChRs along with synaptopodin. In vitro studies, nephrin expression in podocyte was decreased by nicotine. Nicotine stimulated podocyte ROS generation; nonetheless, antioxidants such as N-acetyl cysteine (NAC) and TEMPOL (superoxide dismutase mimetic agent) inhibited this effect of nicotine. Nicotine did not modulate proliferation but promoted apoptosis in podocytes. Nicotine enhanced podocyte phosphorylation of ERK1/2, JNK, and p38, and their specific inhibitors attenuated nicotine-induced apoptosis. nAChR antagonists significantly suppressed the effects of nicotine on podocyte. Conclusions Nicotine induces podocyte apoptosis through ROS generation and associated downstream MAPKs signaling. The present study provides

6-Shogaol induces apoptosis in human leukemia cells through a process involving caspase-mediated cleavage of eIF2α

PubMed Central

2013-01-01

Background 6-Shogaol is a promising antitumor agent isolated from dietary ginger (Zingiber officinale). However, little is known about the efficacy of 6-shogaol on leukemia cells. Here we investigated the underlying mechanism of 6-shogaol induced apoptosis in human leukemia cells in vitro and in vivo. Methods Three leukemia cell lines and primary leukemia cells were used to investigate the apoptosis effect of 6-shogaol. A shotgun approach based on label-free proteome with LC-CHIP Q-TOF MS/MS was employed to identify the cellular targets of 6-shogaol and the differentially expressed proteins were analyzed by bioinformatics protocols. Results The present study indicated that 6-shogaol selectively induced apoptosis in transformed and primary leukemia cells but not in normal cells. Eukaryotic translation initiation factor 2 alpha (eIF2α), a key regulator in apoptosis signaling pathway, was significantly affected in both Jurkat and U937 proteome profiles. The docking results suggested that 6-shogaol might bind well to eIF2α at Ser51 of the N-terminal domain. Immunoblotting data indicated that 6-shogaol induced apoptosis through a process involving dephosphorylation of eIF2α and caspase activation–dependent cleavage of eIF2α. Furthermore, 6-shogaol markedly inhibited tumor growth and induced apoptosis in U937 xenograft mouse model. Conclusion The potent anti-leukemia activity of 6-shogaol found both in vitro and in vivo in our study make this compound a potential anti-tumor agent for hematologic malignancies. PMID:24215632

Acetaminophen and Metamizole Induce Apoptosis in HT 29 and SW 480 Colon Carcinoma Cell Lines In Vitro.

PubMed

Bundscherer, Anika C; Malsy, Manuela; Gruber, Michael A; Graf, Bernhard M; Sinner, Barbara

2018-02-01

The perioperative phase is supposed to be a period with high vulnerability for cancer dissemination. Acetaminophen and metamizole are common analgesics administered during this phase. We investigated the effect of acetaminophen, metamizole and 4-methylaminoantipyrine (MAA) on proliferation and apoptosis of colon carcinoma cell lines (SW 480 and HT 29). Proliferation was detected by cell proliferation ELISA BrdU, and apoptosis by Annexin V staining. Cytochrome c and caspase 3, 8 and 9 expression levels were detected by western blot. Acetaminophen, metamizole or MAA caused slight changes in proliferation. Acetaminophen, metamizole or the combination increased apoptosis in both cell lines. All agents decreased caspase 3 and 8 expression in SW480. Acetaminophen decreased caspase 9 expression in both cell lines. In clinically relevant doses, acetaminophen and/or metamizole induce apoptosis in both colon cancer cell lines. Both mitochondrial and death receptor pathways might be involved in acetaminophen-induced apoptosis. Copyright© 2018, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Laminarin-induced apoptosis in human colon cancer LoVo cells

PubMed Central

JI, CHEN-FENG; JI, YU-BIN

2014-01-01

A number of scientific studies have revealed that laminarin has antitumor effects. Therefore, the aim of the present study was to investigate the apoptosis of LoVo cells and the underlying mechanisms induced by laminarin. LoVo cells were treated with various concentrations of laminarin and fluorescence-inverted microscopy was used to observe the morphology of LoVo cells treated with laminarin. In addition, western blotting was performed to analyze the expression levels of death receptor (DR)4, DR5, TNF-related apoptosis-inducing ligand (TRAIL), Fas-associated protein with death domain (FADD), caspase-8, caspase-3, Bid and tBid. Flow cytometry was conducted to analyze the expressions of Bcl-2 and Bax, and spectrophotometry was performed to quantify the activity of caspases-8, -3, -6 and -7. Following the treatment of LoVo cells with laminarin for 24 h, the expression levels of DR4, DR5, TRAIL, FADD, Bid, tBid and Bax were observed to be upregulated, whereas the expression levels of pro-caspase-8, pro-caspase-3 and Bcl-2 were downregulated. In addition, the activities of casapse-8, -3, -6 and -7 were observed to increase, which was a significant difference when compared with those of the control group. Therefore, laminarin is considered to induce the apoptosis of LoVo cells, which may occur via a DR pathway, suggesting that laminarin may be a potent agent for cancer treatment. PMID:24765209

Laminarin-induced apoptosis in human colon cancer LoVo cells.

PubMed

Ji, Chen-Feng; Ji, Yu-Bin

2014-05-01

A number of scientific studies have revealed that laminarin has antitumor effects. Therefore, the aim of the present study was to investigate the apoptosis of LoVo cells and the underlying mechanisms induced by laminarin. LoVo cells were treated with various concentrations of laminarin and fluorescence-inverted microscopy was used to observe the morphology of LoVo cells treated with laminarin. In addition, western blotting was performed to analyze the expression levels of death receptor (DR)4, DR5, TNF-related apoptosis-inducing ligand (TRAIL), Fas-associated protein with death domain (FADD), caspase-8, caspase-3, Bid and tBid. Flow cytometry was conducted to analyze the expressions of Bcl-2 and Bax, and spectrophotometry was performed to quantify the activity of caspases-8, -3, -6 and -7. Following the treatment of LoVo cells with laminarin for 24 h, the expression levels of DR4, DR5, TRAIL, FADD, Bid, tBid and Bax were observed to be upregulated, whereas the expression levels of pro-caspase-8, pro-caspase-3 and Bcl-2 were downregulated. In addition, the activities of casapse-8, -3, -6 and -7 were observed to increase, which was a significant difference when compared with those of the control group. Therefore, laminarin is considered to induce the apoptosis of LoVo cells, which may occur via a DR pathway, suggesting that laminarin may be a potent agent for cancer treatment.

Cyanidin-3-glucoside isolated from mulberry fruits protects pancreatic β-cells against glucotoxicity-induced apoptosis.

PubMed

Lee, Jong Seok; Kim, Young Rae; Park, Jun Myoung; Kim, Young Eon; Baek, Nam In; Hong, Eock Kee

2015-04-01

The present study investigated the cytoprotective effects of cyanidin‑3‑glucoside (C3G), isolated from mulberry fruits, on the glucotoxicity‑induced apoptosis of pancreatic β‑cells to evaluate the antidiabetic effects of this compound. MIN6N pancreatic β‑cells were used to investigate the cytoprotective effects of C3G. In addition, the effects of C3G on the glucotoxicity‑induced apoptosis of pancreatic β‑cells was evaluated using MTT assay, immunofluorescent staining, flow cytometric and western blot analyses. The pancreatic β‑cells cultured under high glucose conditions exhibited distinct apoptotic features. C3G decreased the generation of intracellular reactive oxygen species, DNA fragmentation and the rate of apoptosis. C3G also prevented pancreatic β‑cell apoptosis induced by high glucose conditions by interfering with the intrinsic apoptotic pathways. In addition, C3G treatment resulted in increased insulin secretion compared with treatment with high glucose only. In conclusion, the results of the present study suggested that C3G obtained from mulberry fruits may be a potential phytotherapeutic agent for the prevention of diabetes.

Protection from radiation-induced apoptosis by the radioprotector amifostine (WR-2721) is radiation dose dependent.

PubMed

Ormsby, Rebecca J; Lawrence, Mark D; Blyth, Benjamin J; Bexis, Katrina; Bezak, Eva; Murley, Jeffrey S; Grdina, David J; Sykes, Pamela J

2014-02-01

The radioprotective agent amifostine is a free radical scavenger that can protect cells from the damaging effects of ionising radiation when administered prior to radiation exposure. However, amifostine has also been shown to protect cells from chromosomal mutations when administered after radiation exposure. As apoptosis is a common mechanism by which cells with mutations are removed from the cell population, we investigated whether amifostine stimulates apoptosis when administered after radiation exposure. We chose to study a relatively low dose which is the maximum radiation dose for radiation emergency workers (0.25 Gy) and a high dose relevant to radiotherapy exposures (6 Gy). Mice were administered 400 mg/kg amifostine 30 min before, or 3 h after, whole-body irradiation with 0.25 or 6 Gy X-rays and apoptosis was analysed 3 or 7 h later in spleen and bone marrow. We observed a significant increase in radiation-induced apoptosis in the spleen of mice when amifostine was administered before or after 0.25 Gy X-rays. In contrast, when a high dose of radiation was used (6 Gy), amifostine caused a reduction in radiation-induced apoptosis 3 h post-irradiation in spleen and bone marrow similar to previously published studies. This is the first study to investigate the effect of amifostine on radiation-induced apoptosis at a relatively low radiation dose and the first to demonstrate that while amifostine can reduce apoptosis from high doses of radiation, it does not mediate the same effect in response to low-dose exposures. These results suggest that there may be a dose threshold at which amifostine protects from radiation-induced apoptosis and highlight the importance of examining a range of radiation doses and timepoints.

Differences in the rate of oestrogen-induced apoptosis in breast cancer by oestradiol and the triphenylethylene bisphenol

PubMed Central

Obiorah, I E; Jordan, V C

2014-01-01

Background and Purpose Triphenylethylene (TPE)-like compounds were the first agents to be used in the treatment of metastatic breast cancer in postmenopausal women. Although structurally related to the anti-oestrogen, 4-hydroxytamoxifen, TPEs possess oestrogenic properties in fully oestrogenized breast cancer cells but do not induce apoptosis with short-term treatment in long-term oestrogen-deprived breast cancer cells. This study determined the differential effects of bisphenol, a TPE, on growth and apoptosis based on the modulation of the shape of the ligand–oestrogen receptor complex. Experimental Approach Apoptotic flow cytometric studies were used to evaluate apoptosis over time. Proliferation of the breast cancer cells was assessed using DNA quantification and cell cycle analysis. Real-time PCR was performed to quantify mRNA levels of apoptotic genes. Regulation of cell cycle and apoptotic genes was determined using PCR-based arrays. Key Results Bisphenol induced an up-regulation of cell cycle genes similar to those induced by 17β oestradiol (E2). Unlike the changes induced by E2 that occur after 24 h, the apoptosis evoked by bisphenol occurred after 4 days, with quantifiable apoptotic changes noted at 6 days. A prolonged up-regulation of endoplasmic reticulum stress and inflammatory stress response genes was observed with subsequent activation of apoptosis-related genes in the second week of treatment with bisphenol. Conclusions and Implications The bisphenol: ERα complex induces delayed biological effects on the growth and apoptosis of breast cancer cells. Both the shape of the complex and the duration of treatment control the initiation of apoptosis. PMID:24819221

Glabridin induces apoptosis and cell cycle arrest in oral cancer cells through the JNK1/2 signaling pathway.

PubMed

Chen, Chang-Tai; Chen, Yi-Tzu; Hsieh, Yi-Hsien; Weng, Chia-Jui; Yeh, Jung-Chun; Yang, Shun-Fa; Lin, Chiao-Wen; Yang, Jia-Sin

2018-06-01

Glabridin, a flavonoid extracted from licorice (Glycyrrhiza glabra), possesses various biological properties, including anticancer activities. However, the effect of glabridin on oral cancer cell apoptosis and the underlying molecular mechanisms has not been elucidated. In this study, we demonstrated that glabridin treatment significantly inhibits cell proliferation in human oral cancer SCC-9 and SAS cell lines. Flow cytometric assays demonstrated that glabridin induced several features of apoptosis, such as sub-G1 phase cell increase and phosphatidylserine externalization. Furthermore, glabridin induced apoptosis dose-dependently in SCC-9 cells through caspase-3, -8, and -9 activation and poly (ADP-ribose) polymerase cleavage. Moreover, glabridin increased the phosphorylation of the extracellular signal-regulated kinase, p38, and c-Jun N-terminal kinase (JNK) pathways in a dose-dependent manner. Moreover, the inhibition of the JNK1/2 inhibitor significantly reversed the glabridin-induced activation of the caspase pathway. In conclusion, our findings suggest that glabridin induces oral cancer cell apoptosis through the JNK1/2 pathway and is a potential therapeutic agent for oral cancer. © 2018 Wiley Periodicals, Inc.

6-mercaptopurine (6-MP) induces p53-mediated apoptosis of neural progenitor cells in the developing fetal rodent brain.

PubMed

Kanemitsu, H; Yamauchi, H; Komatsu, M; Yamamoto, S; Okazaki, S; Uchida, K; Nakayama, H

2009-01-01

6-mercaptopurine (6-MP), a DNA-damaging agent, induces apoptosis of neural progenitor cells, and causes malformation in the fetal brain. The aim of the present study is to clarify the molecular pathway of 6-MP-induced apoptosis of neural progenitor cells in the fetal telencephalon of rats and mice. p53 protein is activated by DNA damage and induces apoptosis through either the intrinsic pathway involving the mitochondria or the extrinsic pathway triggered by death receptors. In this study, the expression of puma and cleaved caspase-9 proteins, which are specific intrinsic pathway factors, increased in the rat telencephalon after 6-MP treatment. 6-MP-induced apoptosis of neural progenitor cells was completely absent in p53-deficient mice. On the other hand, the expression of Fas protein, an extrinsic pathway factor, did not change throughout the experimental period in the rat telencephalon treated with 6-MP. The number of apoptotic neural progenitor cells was similar among Fas-mutated lpr/lpr and wild-type mice, suggesting that the Fas pathway does not play a significant role in 6-MP-induced apoptosis of neural progenitor cells. These results may suggest that the p53-mediated intrinsic pathway is essential for 6-MP-induced apoptosis of neural progenitor cells in the developing telencephalon of rats and mice.

Quercetin-induced apoptosis prevents EBV infection

PubMed Central

Lee, Minjung; Son, Myoungki; Ryu, Eunhyun; Shin, Yu Su; Kim, Jong Gwang; Kang, Byung Woog; Sung, Gi-Ho; Cho, Hyosun; Kang, Hyojeung

2015-01-01

Epstein-Barr virus (EBV) is a human gamma-1 herpesvirus that establishes a lifelong latency in over 90% of the world's population. During latency, virus exists predominantly as a chromatin-associated, multicopy episome in the nuclei of a variety of tumor cells derived from B cells, T cells, natural killer (NK) cells, and epithelial cells. Licorice is the root of Glycyrrhiza uralensis or G. glabra that has traditionally cultivated in eastern part of Asia. Licorice was reported to have anti-viral, anti-inflammatory, anti-atopic, hepatoprotective, anti-neurodegenerative, anti-tumor, anti-diabetic effects and so forth. Quercetin and isoliquiritigenin are produced from licorice and highly similar in molecular structure. They have diverse bioactive effects such as antiviral activity, anti-asthmatic activity, anti-cancer activity, anti-inflammation activity, monoamine-oxidase inhibitor, and etc. To determine anti-EBV and anti-EBVaGC (Epstein-Barr virus associated gastric carcinoma) effects of licorice, we investigated antitumor and antiviral effects of quercetin and isoliquiritigenin against EBVaGC. Although both quercetin and isoliquiritigenin are cytotoxic to SNU719 cells, quercetin induced more apoptosis in SNU719 cells than isoliquiritigenin, more completely eliminated DNMT1 and DNMT3A expressions than isoliquiritigenin, and more strongly affects the cell cycle progression of SNU719 than isoliquiritigenin. Both quercetin and isoliquiritigenin induce signal transductions to stimulate apoptosis, and induce EBV gene transcription. Quercetin enhances frequency of F promoter use, whereas isoliquiritigenin enhances frequency of Q promoter use. Quercetin reduces EBV latency, whereas isoliquiritigenin increases the latency. Quercetin increases more the EBV progeny production, and inhibits more EBV infection than isoliquiritigenin. These results indicate that quercetin could be a promising candidate for antiviral and antitumor agents against EBV and human gastric carcinoma

cAMP prevents TNF-induced apoptosis through inhibiting DISC complex formation in rat hepatocytes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bhattacharjee, Rajesh; Xiang, Wenpei; Family Planning Research Institute, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, People's Republic of China

2012-06-22

Highlights: Black-Right-Pointing-Pointer cAMP blocks cell death induced by TNF and actinomycin D in cultured hepatocytes. Black-Right-Pointing-Pointer cAMP blocks NF-{kappa}B activation induced by TNF and actinomycin D. Black-Right-Pointing-Pointer cAMP blocks DISC formation following TNF and actinomycin D exposure. Black-Right-Pointing-Pointer cAMP blocks TNF signaling at a proximal step. -- Abstract: Tumor necrosis factor {alpha} (TNF) is a pleiotropic proinflammatory cytokine that plays a role in immunity and the control of cell proliferation, cell differentiation, and apoptosis. The pleiotropic nature of TNF is due to the formation of different signaling complexes upon the binding of TNF to its receptor, TNF receptor type 1more » (TNFR1). TNF induces apoptosis in various mammalian cells when the cells are co-treated with a transcription inhibitor like actinomycin D (ActD). When TNFR1 is activated, it recruits an adaptor protein, TNF receptor-associated protein with death domain (TRADD), through its cytoplasmic death effector domain (DED). TRADD, in turn, recruits other signaling proteins, including TNF receptor-associated protein 2 (TRAF2) and receptor-associated protein kinase (RIPK) 1, to form a complex. Subsequently, this complex combines with FADD and procaspase-8, converts into a death-inducing signaling complex (DISC) to induce apoptosis. Cyclic AMP (cAMP) is a second messenger that regulates various cellular processes such as cell proliferation, gene expression, and apoptosis. cAMP analogues are reported to act as anti-apoptotic agents in various cell types, including hepatocytes. We found that a cAMP analogue, dibutyryl cAMP (db-cAMP), inhibits TNF + ActD-induced apoptosis in rat hepatocytes. The protein kinase A (PKA) inhibitor KT-5720 reverses this inhibitory effect of cAMP on apoptosis. Cytoprotection by cAMP involves down-regulation of various apoptotic signal regulators like TRADD and FADD and inhibition of caspase-8 and caspase-3 cleavage. We

The role of ARK in stress-induced apoptosis in Drosophila cells

PubMed Central

Zimmermann, Katja C.; Ricci, Jean-Ehrland; Droin, Nathalie M.; Green, Douglas R.

2002-01-01

The molecular mechanisms of apoptosis are highly conserved throughout evolution. The homologs of genes essential for apoptosis in Caenorhabditis elegans and Drosophila melanogaster have been shown to be important for apoptosis in mammalian systems. Although a homologue for CED-4/apoptotic protease-activating factor (Apaf)-1 has been described in Drosophila, its exact function and the role of the mitochondrial pathway in its activation remain unclear. Here, we used the technique of RNA interference to dissect apoptotic signaling pathways in Drosophila cells. Inhibition of the Drosophila CED-4/Apaf-1–related killer (ARK) homologue resulted in pronounced inhibition of stress-induced apoptosis, whereas loss of ARK did not protect the cells from Reaper- or Grim-induced cell death. Reduction of DIAP1 induced rapid apoptosis in these cells, whereas the inhibition of DIAP2 expression did not but resulted in increased sensitivity to stress-induced apoptosis; apoptosis in both cases was prevented by inhibition of ARK expression. Cells in which cytochrome c expression was decreased underwent apoptosis induced by stress stimuli, Reaper or Grim. These results demonstrate the central role of ARK in stress-induced apoptosis, which appears to act independently of cytochrome c. Apoptosis induced by Reaper or Grim can proceed via a distinct pathway, independent of ARK. PMID:11901172

α-Hispanolol sensitizes hepatocellular carcinoma cells to TRAIL-induced apoptosis via death receptor up-regulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mota, Alba, E-mail: amota@iib.uam.es; Jiménez-Garcia, Lidia, E-mail: ljimenez@isciii.es; Herránz, Sandra, E-mail: sherranz@isciii.es

Hispanolone derivatives have been previously described as anti-inflammatory and antitumoral agents. However, their effects on overcoming Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) resistance remain to be elucidated. In this study, we analyzed the cytotoxic effects of the synthetic hispanolone derivative α-hispanolol (α-H) in several tumor cell lines, and we evaluated the induction of apoptosis, as well as the TRAIL-sensitizing potential of α-H in the hepatocellular carcinoma cell line HepG2. Our data show that α-H decreased cell viability in a dose-dependent manner in HeLa, MDA-MB231, U87 and HepG2 cell lines, with a more prominent effect in HepG2 cells. Interestingly, α-H hadmore » no effect on non-tumoral cells. α-H induced activation of caspase-8 and caspase-9 and also increased levels of the proapoptotic protein Bax, decreasing antiapoptotic proteins (Bcl-2, X-IAP and IAP-1) in HepG2 cells. Specific inhibition of caspase-8 abrogated the cascade of caspase activation, suggesting that the extrinsic pathway has a critical role in the apoptotic events induced by α-H. Furthermore, combined treatment of α-H with TRAIL enhanced apoptosis in HepG2 cells, activating caspase-8 and caspase-9. This correlated with up-regulation of both the TRAIL death receptor DR4 and DR5. DR4 or DR5 neutralizing antibodies abolished the effect of α-H on TRAIL-induced apoptosis, suggesting that sensitization was mediated through the death receptor pathway. Our results demonstrate that α-H induced apoptosis in the human hepatocellular carcinoma cell line HepG2 through activation of caspases and induction of the death receptor pathway. In addition, we describe a novel function of α-H as a sensitizer on TRAIL-induced apoptotic cell death in HepG2 cells. - Highlights: • α-Hispanolol induced apoptosis in the human hepatocellular carcinoma cell line HepG2. • α-Hispanolol induced activation of caspases and the death receptor pathway. • �

Caffeine and caffeine sodium benzoate have a sunscreen effect, enhance UVB-induced apoptosis, and inhibit UVB-induced skin carcinogenesis in SKH-1 mice.

PubMed

Lu, Yao-Ping; Lou, You-Rong; Xie, Jian-Guo; Peng, Qing-Yun; Zhou, Sherry; Lin, Yong; Shih, Weichung Joe; Conney, Allan H

2007-01-01

Topical application of caffeine sodium benzoate (caffeine-SB) immediately after UVB irradiation of SKH-1 mice enhanced UVB-induced apoptosis by a 2- to 3-fold greater extent than occurred after the topical application of an equimolar amount of caffeine. Although topical application of caffeine-SB or caffeine enhanced UVB-induced apoptosis, both substances were inactive on non-UVB-treated normal skin. Topical application of caffeine-SB or caffeine (each has UVB absorption properties) 0.5 h before irradiation with a high dose of UVB decreased UVB-induced thymine dimer formation and sunburn lesions (sunscreen effect). Caffeine-SB was more active than an equimolar amount of caffeine in exerting a sunscreen effect. In additional studies, caffeine-SB strongly inhibited the formation of tumors in UVB-pretreated 'high-risk mice' and in tumor-bearing mice, and the growth of UVB-induced tumors was also inhibited. Caffeine-SB and caffeine are the first examples of compounds that have both a sunscreen effect and enhance UVB-induced apoptosis. Our studies suggest that caffeine-SB and caffeine may be good agents for inhibiting the formation of sunlight-induced skin cancer.

Hard clam extracts induce atypical apoptosis in human gastric cancer cells

PubMed Central

Song, Eing-Ju; Chan, Michael W.Y.; Shin, Jyh-Wei; Chen, Che-Chun

2017-01-01

Hard clams (HCs) are a nutritionally high-quality and popular seafood, and are established to be a potent antitumor food. The aim of the present study was to determine whether HC extracts induce apoptosis in the human gastric cancer cell line, AGS. In contrast with previously reported methods of extraction, crude extracts of HC were obtained by freezing and thawing and by a method free of hot water or organic solvents. The composition, quality and properties of the HC extracts were demonstrated to be stable since the extracts that were evaluated by capillary electrophoresis and HPLC analysis at different timepoints were similar. HC extracts also have an inhibitory effect against the survival of AGS cells. Treatment with HC extracts induced a marked sub-G1 DNA peak and reduced the expression of the anti-apoptotic genes BIRC5 and KPNA2. However, hallmarks of classical apoptosis such as DNA fragmentation and apoptotic body formation were not observed, indicating atypical apoptosis. Furthermore, it was revealed that HC extracts interrupted cell cycle progression in AGS cells through altered expression of six cell cycle-associated genes: CDC20, KPNA2, BIRC5, ANAPC2, CDKN1A and RB1. The present findings suggest that HC may contribute to a novel future anticancer agent. PMID:28810604

Apoptosis of human gastric cancer SGC-7901 cells induced by podophyllotoxin.

PubMed

Ji, Chen-Feng; Ji, Yu-Bin

2014-05-01

Numerous studies have demonstrated that podophyllotoxin and its derivatives exhibit antitumor effects. The aim of the present study was to investigate SGC-7901 cell apoptosis and the underlying mechanism induced by podophyllotoxin. SGC-7901 cells were treated with varying concentrations of podophyllotoxin. MTT assays and flow cytometry were used to evaluate the effects of podophyllotoxin on the proliferation and apoptosis of SGC-7901 cells, while fluorescence inverted microscopy was used to observe the morphology of SGC-7901 cells that had been dyed with Hoechst 33258. In addition, laser scanning confocal microscopy was used to analyze the mitochondrial membrane potential (MMP) of SGC-7901 cells dyed with Rhodamine 123. Western blotting was performed to analyze the expression levels of cytochrome c (cyt- c ), caspase-9 and caspase-3 in the SGC-7901 cells. The results indicated that podophyllotoxin was capable of inhibiting growth and inducing the apoptosis of SGC-7901 cells in a dose-dependent manner, causing cell cycle arrest at the G 2 /M phase. After 48 h of treatment, the apoptotic morphology of SGC-7901 cells was clear, exhibiting cell protuberance, concentrated cytoplasms and apoptotic bodies. Following 24 h of treatment, the MMP of the SGC-7901 cells decreased. In addition, after 48 h, the expression of cyt- c was shown to be upregulated, while the expression levels of pro-caspase-9 and pro-caspase-3 in the SGC-7901 cells were shown to be downregulated. In conclusion, apoptosis can be induced in SGC-7901 cells by podophyllotoxin, potentially via a mitochondrial pathway, indicating that podophyllotoxin may be a potent agent for cancer treatment.

PUMA mediates ER stress-induced apoptosis in portal hypertensive gastropathy

PubMed Central

Tan, S; Wei, X; Song, M; Tao, J; Yang, Y; Khatoon, S; Liu, H; Jiang, J; Wu, B

2014-01-01

Mucosal apoptosis has been demonstrated to be an essential pathological feature in portal hypertensive gastropathy (PHG). p53-upregulated modulator of apoptosis (PUMA) was identified as a BH3-only Bcl-2 family protein that has an essential role in apoptosis induced by a variety of stimuli, including endoplasmic reticulum (ER) stress. However, whether PUMA is involved in mucosal apoptosis in PHG remains unclear, and whether PUMA induces PHG by mediating ER stress remains unknown. The aim of the study is to investigate whether PUMA is involved in PHG by mediating ER stress apoptotic signaling. To identify whether PUMA is involved in PHG by mediating ER stress, gastric mucosal injury and apoptosis were studied in both PHG patients and PHG animal models using PUMA knockout (PUMA-KO) and PUMA wild-type (PUMA-WT) mice. The induction of PUMA expression and ER stress signaling were investigated, and the mechanisms of PUMA-mediated apoptosis were analyzed. GES-1 and SGC7901 cell lines were used to further identify whether PUMA-mediated apoptosis was induced by ER stress in vitro. Epithelial apoptosis and PUMA were markedly induced in the gastric mucosa of PHG patients and mouse PHG models. ER stress had a potent role in the induction of PUMA and apoptosis in PHG models, and the apoptosis was obviously attenuated in PUMA-KO mice. Although the targeted deletion of PUMA did not affect ER stress, mitochondrial apoptotic signaling was downregulated in mice. Meanwhile, PUMA knockdown significantly ameliorated ER stress-induced mitochondria-dependent apoptosis in vitro. These results indicate that PUMA mediates ER stress-induced mucosal epithelial apoptosis through the mitochondrial apoptotic pathway in PHG, and that PUMA is a potentially therapeutic target for PHG. PMID:24625987

Minocycline attenuates colistin-induced neurotoxicity via suppression of apoptosis, mitochondrial dysfunction and oxidative stress

PubMed Central

Dai, Chongshan; Ciccotosto, Giuseppe D.; Cappai, Roberto; Wang, Yang; Tang, Shusheng; Xiao, Xilong; Velkov, Tony

2017-01-01

Background: Neurotoxicity is an adverse effect patients experience during colistin therapy. The development of effective neuroprotective agents that can be co-administered during polymyxin therapy remains a priority area in antimicrobial chemotherapy. The present study investigates the neuroprotective effect of the synergistic tetracycline antibiotic minocycline against colistin-induced neurotoxicity. Methods: The impact of minocycline pretreatment on colistin-induced apoptosis, caspase activation, oxidative stress and mitochondrial dysfunction were investigated using cultured mouse neuroblastoma-2a (N2a) and primary cortical neuronal cells. Results: Colistin-induced neurotoxicity in mouse N2a and primary cortical cells gives rise to the generation of reactive oxygen species (ROS) and subsequent cell death via apoptosis. Pretreatment of the neuronal cells with minocycline at 5, 10 and 20 μM for 2 h prior to colistin (200 μM) exposure (24 h), had an neuroprotective effect by significantly decreasing intracellular ROS production and by upregulating the activities of the anti-ROS enzymes superoxide dismutase and catalase. Minocycline pretreatment also protected the cells from colistin-induced mitochondrial dysfunction, caspase activation and subsequent apoptosis. Immunohistochemical imaging studies revealed colistin accumulates within the dendrite projections and cell body of primary cortical neuronal cells. Conclusions: To our knowledge, this is first study demonstrating the protective effect of minocycline on colistin-induced neurotoxicity by scavenging of ROS and suppression of apoptosis. Our study highlights that co-administration of minocycline kills two birds with one stone: in addition to its synergistic antimicrobial activity, minocycline could potentially ameliorate unwanted neurotoxicity in patients undergoing polymyxin therapy. PMID:28204513

Acute dyskerin depletion triggers cellular senescence and renders osteosarcoma cells resistant to genotoxic stress-induced apoptosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lin, Ping; Mobasher, Maral E.; Alawi, Faizan, E-mail: falawi@upenn.edu

Highlights: • Dyskerin depletion triggers cellular senescence in U2OS osteosarcoma cells. • Dyskerin-depleted cells are resistant to apoptosis induced by genotoxic stress. • Chromatin relaxation sensitizes dyskerin-depleted cells to apoptosis. - Abstract: Dyskerin is a conserved, nucleolar RNA-binding protein implicated in an increasing array of fundamental cellular processes. Germline mutation in the dyskerin gene (DKC1) is the cause of X-linked dyskeratosis congenita (DC). Conversely, wild-type dyskerin is overexpressed in sporadic cancers, and high-levels may be associated with poor prognosis. It was previously reported that acute loss of dyskerin function via siRNA-mediated depletion slowed the proliferation of transformed cell lines. However,more » the mechanisms remained unclear. Using human U2OS osteosarcoma cells, we show that siRNA-mediated dyskerin depletion induced cellular senescence as evidenced by proliferative arrest, senescence-associated heterochromatinization and a senescence-associated molecular profile. Senescence can render cells resistant to apoptosis. Conversely, chromatin relaxation can reverse the repressive effects of senescence-associated heterochromatinization on apoptosis. To this end, genotoxic stress-induced apoptosis was suppressed in dyskerin-depleted cells. In contrast, agents that induce chromatin relaxation, including histone deacetylase inhibitors and the DNA intercalator chloroquine, sensitized dyskerin-depleted cells to apoptosis. Dyskerin is a core component of the telomerase complex and plays an important role in telomere homeostasis. Defective telomere maintenance resulting in premature senescence is thought to primarily underlie the pathogenesis of X-linked DC. Since U2OS cells are telomerase-negative, this leads us to conclude that loss of dyskerin function can also induce cellular senescence via mechanisms independent of telomere shortening.« less

Rottlerin-induced autophagy leads to the apoptosis in breast cancer stem cells: molecular mechanisms.

PubMed

Kumar, Dhruv; Shankar, Sharmila; Srivastava, Rakesh K

2013-12-23

Autophagy is an indispensable lysosomal self-digestion process involved in the degradation of aggregated proteins and damaged organelles. Autophagy is associated with the several pathological processes, including cancer. Cancer stem cells (CSCs) play significant roles in cancer initiation, progression and drug resistance. Recent studies have demonstrated the antitumor activities of plant-derived chemopreventive agent rottlerin (Rott). However, the molecular mechanism by which Rott induces autophagy in breast CSCs has not been investigated. The objectives of this study were to examine the molecular mechanism by which Rott induces autophagy which leads to apoptosis in breast CSCs. Treatment of breast CSCs with Rott for 24 h resulted in a concentration dependent induction of autophagy, followed by apoptosis as measured by flow cytometry. Electron microscopy confirmed the presence of autophagosomes in Rott treated breast CSCs. Western blot analysis showed that Rott treatment increased the expression of LC3, Beclin-1 and Atg12 that are accumulated during autophagy. Prolonged exposure of breast CSCs to Rott caused apoptosis which was associated with the suppression of phosphorylated Akt and mTOR, upregulation of phosphorylated AMPK, and downregulation of anti-apoptosis Bcl-2, Bcl-X(L), XIAP and cIAP-1. Knock-down of Atg7 or Beclin-1 by shRNA inhibited Rott-induced autophagy at 24 h. Our study also demonstrates that pre-treatment of breast CSCs with autophagosome inhibitors 3-methyladenine and Bafilomycin, as well as protein synthesis inhibitor cycloheximide inhibited Rott-induced autophagy and apoptosis. Rott induces autophagy via extensive cytoplasmic vacuolization in breast CSCs. Molecular docking results between C2-domain of protein kinase C-delta and Rott indicated that both hydrogen bonding and hydrophobic interactions contributed significantly for ligand binding with minimum binding affinity of ≈ 7.5 Kcal/mol. Although, autophagy inhibitors suppress the formation

EGCG inhibits Cd(2+)-induced apoptosis through scavenging ROS rather than chelating Cd(2+) in HL-7702 cells.

PubMed

An, Zhen; Qi, Yongmei; Huang, Dejun; Gu, Xueyan; Tian, Yihong; Li, Ping; Li, Hui; Zhang, Yingmei

2014-05-01

Epigallocatechin-3-gallat (EGCG), the major catechin in green tea, shows a potential protective effect against heavy metal toxicity to humans. Apoptosis is one of the key events in cadmium (Cd(2+))-induced cytotoxicity. Nevertheless, the study of EGCG on Cd(2+)-induced apoptosis is rarely reported. The objective of this study was to clarify the effect and detailed mechanism of EGCG on Cd(2+)-induced apoptosis. Normal human liver cells (HL-7702) were treated with Cd(2+) for 21 h, and then co-treated with EGCG for 3 h. Cell viability, apoptosis, intracellular reactive oxygen species (ROS), malondialdehyde (MDA), mitochondrial membrane potential (MMP) and caspase-3 activity were detected. On the other hand, the chelation of Cd(2+) with EGCG was tested by UV-Vis spectroscopy analysis and Nuclear Magnetic Resonance ((1)H NMR) spectroscopy under neutral condition (pH 7.2). Cd(2+) significantly decreased the cell viability and induced apoptosis in HL-7702 cells. Conversely, EGCG co-treatment resulted in significant inhibition of Cd(2+)-induced reduction of cell viability and apoptosis, implying a rescue effect of EGCG against Cd(2+) poisoning. The protective effect most likely arises from scavenging ROS and maintaining redox homeostasis, as the generation of intracellular ROS and MDA is significantly reduced by EGCG, which further prevents MMP collapse and suppresses caspase-3 activity. However, no evidence is observed for the chelation of EGCG with Cd(2+) under neutral condition. Therefore, a clear conclusion from this work can be made that EGCG could inhibit Cd(2+)-induced apoptosis by acting as a ROS scavenger rather than a metal chelating agent.

Fasudil inhibits the proliferation and contractility and induces cell cycle arrest and apoptosis of human endometriotic stromal cells: a promising agent for the treatment of endometriosis.

PubMed

Tsuno, Akitoshi; Nasu, Kaei; Kawano, Yukie; Yuge, Akitoshi; Li, Haili; Abe, Wakana; Narahara, Hisashi

2011-12-01

During the development of endometriotic lesions, excess fibrosis may lead to scarring and to the alterations of tissue function that are the characteristic features of this disease. Enhanced extracellular matrix contractility of endometriotic stromal cells (ECSC) mediated by the mevalonate-Ras homology (Rho)/Rho-associated coiled-coil-forming protein kinase (ROCK) pathway has been shown to contribute to the pathogenesis of endometriosis. To assess the use of fasudil, a selective ROCK inhibitor, for the medical treatment of endometriosis-associated fibrosis, the effects of this agent on the cell proliferation, apoptosis, cell cycle, morphology, cell density, and contractility of ECSC were investigated. The effects of fasudil on the expression of contractility-related, apoptosis-related, and cell cycle-related molecules in ECSC were also evaluated. Fasudil significantly inhibited the proliferation and contractility of ECSC and induced the cell cycle arrest in the G2/M phase and apoptosis of these cells. Morphological observation revealed the suppression of ECSC attachment to collagen fibers and decrease of cell density by fasudil. The expression of α-smooth muscle actin, RhoA, ROCK-I, and ROCK-II proteins was inhibited by fasudil administration. The expression of the antiapoptotic factors, Bcl-2 and Bcl-X(L), in two-dimensional cultured ECSC were down-regulated by the addition of fasudil, whereas, the expression of p16(INK4a) and p21(Waf1/Cip1) was up-regulated by the addition of fasudil. The present findings suggest that fasudil is a promising agent for the treatment of endometriosis. The inhibition of cell proliferation, contractility, and myofibroblastic differentiation, the attenuation of attachment to collagen fibers, the decrease of cell density, and the induction of cell cycle arrest and apoptosis of ECSC are involved in the active mechanisms of fasudil.

Evodiamine Induces Cell Growth Arrest, Apoptosis and Suppresses Tumorigenesis in Human Urothelial Cell Carcinoma Cells.

PubMed

Shi, Chung-Sheng; Li, Jhy-Ming; Chin, Chih-Chien; Kuo, Yi-Hung; Lee, Ying-Ray; Huang, Yun-Ching

2017-03-01

Evodiamine, an indole alkaloid derived from Evodia rutaecarpa, exhibits pharmacological activities including vasodilatation, analgesia, anti-cardiovascular disease, anti-Alzheimer's disease, anti-inflammation, and anti-tumor activity. This study analyzes the anti-tumor effects of evodiamine on cellular growth, tumorigenesis, cell cycle and apoptosis induction of human urothelial cell carcinoma (UCC) cells. The present study showed that evodiamine significantly inhibited the proliferation of UCC cells in a dose- and time-dependent manner. Also, evodiamine suppressed the tumorigenesis of UCC cells in vitro. Moreover, evodiamine caused G 2 /M cell-cycle arrest and induced caspase-dependent apoptosis in UCC cells. Finally, we demonstrated that evodiamine exhibits better cytotoxic than 5-fluorouracil, a clinical chemotherapeutic drug, for UCC cells. Evodiamine induces growth inhibition, tumorigenesis suppression, cell-cycle arrest, and apoptosis induction in human UCC cells. Therefore, this agent displays a therapeutic potential for treating human UCC cells and is worthy for further investigation. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Salidroside mediates apoptosis and autophagy inhibition in concanavalin A-induced liver injury

PubMed Central

Feng, Jiao; Niu, Peiqin; Chen, Kan; Wu, Liwei; Liu, Tong; Xu, Shizan; Li, Jingjing; Li, Sainan; Wang, Wenwen; Lu, Xiya; Yu, Qiang; Liu, Ning; Xu, Ling; Wang, Fan; Dai, Weiqi; Xia, Yujing; Fan, Xiaoming; Guo, Chuanyong

2018-01-01

Salidroside (Sal) is a glycoside extract from Rhodiola rosea L. with anti-inflammatory, antioxidant, anticancer and cardioprotective properties. The present study explored the protective effects and the possible mechanisms of Sal on concanavalin A (ConA)-induced liver injury in mice. Balb/C mice were divided into five groups: Normal control (injected with normal saline), ConA (25 mg/kg), Sal (10 mg/kg) +ConA, Sal (20 mg/kg) + ConA (Sal injected 2 h prior to ConA injection) and Sal (20 mg/kg) only. The serum levels of liver enzymes, pro-inflammatory cytokines, and apoptosis- and autophagy-associated marker proteins were determined at 2, 8 and 24 h after ConA injection. LY294002 was further used to verify whether the phosphoinositide 3-kinase (PI3K)/Akt pathway was activated. Primary hepatocytes were isolated to verify the effect of Sal in vitro. The results indicated that Sal was a safe agent to reduce pathological damage and serum liver enzymes in ConA-induced liver injury. Sal suppressed inflammatory reactions in serum and liver tissues, and activated the PI3K/Akt signaling pathway to inhibit apoptosis and autophagy in vivo and in vitro, which could be reversed by LY294002. In conclusion, Sal attenuated ConA-induced liver injury by modulating PI3K/Akt pathway-mediated apoptosis and autophagy in mice.

Diazoxide triggers cardioprotection against apoptosis induced by oxidative stress.

PubMed

Ichinose, Masashi; Yonemochi, Hidetoshi; Sato, Toshiaki; Saikawa, Tetsunori

2003-06-01

Although mitochondrial ATP-sensitive potassium (mitoK(ATP)) channels have been reported to reduce the extent of apoptosis, the critical timing of mitoK(ATP) channel opening required to protect myocytes against apoptosis remains unclear. In the present study, we examined whether the mitoK(ATP) channel serves as a trigger of cardioprotection against apoptosis induced by oxidative stress. Apoptosis of cultured neonatal rat cardiomyocytes was determined by flow cytometry (light scatter and propidium iodide/annexin V-FITC fluorescence) and by nuclear staining with Hoechst 33342. Mitochondrial membrane potential (DeltaPsi) was measured by flow cytometry of cells stained with rhodamine-123 (Rh-123). Exposure to H(2)O(2) (500 microM) induced apoptosis, and the percentage of apoptotic cells increased progressively and peaked at 2 h. This H(2)O(2)-induced apoptosis was associated with the loss of DeltaPsi, and the time course of decrease in Rh-123 fluorescence paralleled that of apoptosis. Pretreatment of cardiomyocytes with diazoxide (100 microM), a putative mitoK(ATP) channel opener, for 30 min before exposure to H(2)O(2) elicited transient and mild depolarization of DeltaPsi and consequently suppressed both apoptosis and DeltaPsi loss after 2-h exposure to H(2)O(2). These protective effects of diazoxide were abrogated by the mitoK(ATP) channel blocker 5-hydroxydecanoate (500 microM) but not by the sarcolemmal K(ATP) channel blocker HMR-1098 (30 microM). Our results suggest for the first time that diazoxide-induced opening of mitoK(ATP) channels triggers cardioprotection against apoptosis induced by oxidative stress in rat cardiomyocytes.

The mitochondria-mediate apoptosis of Lepidopteran cells induced by azadirachtin.

PubMed

Huang, Jingfei; Lv, Chaojun; Hu, Meiying; Zhong, Guohua

2013-01-01

Mitochondria have been shown to play an important role in apoptosis using mammalian cell lines. However, this seems not to be the case in Drosophila, an insect model organism; thus more in-depth studies of insect cell apoptosis are necessary. In the present study, mitochondrial involvement during azadirachtin- and camptothecin-induced apoptosis in Spodoptera frugiperda Sf9 cells (isolated from Spodoptera frugiperda pupal ovarian tissue) was investigated. The results showed that both azadirachtin and camptothecin could induce apoptosis in Sf9 cells. Reactive oxygen species (ROS) generation, activation of mitochondrial permeability transition pores (MPTPs) and loss of mitochondrial membrane potential (MMP) were observed very early during apoptosis and were followed subsequently by the release of cytochrome-c from the mitochondria. Furthermore, the results also revealed that the opening of MPTPs and the loss of MMP induced by azadirachtin could be significantly inhibited by the permeability transition pore (PTP) inhibitor cyclosporin A (CsA), which was used to identify the key role of mitochondria in the apoptosis of Sf9 cells. However, in camptothecin-treated Sf9 cells, CsA could not suppress the opening of MPTPs and the loss of MMP when apoptosis was induced. The data from caspase-3 and caspase-9 activity assays and detection of apoptosis by morphological observation and flow cytometry also uncovered the different effect of CsA on the two botanical apoptosis inducers. Although different mechanisms of apoptosis induction exist, our study revealed that mitochondria play a crucial role in insect cell line apoptosis.

The Mitochondria-Mediate Apoptosis of Lepidopteran Cells Induced by Azadirachtin

PubMed Central

Huang, Jingfei; Lv, Chaojun; Hu, Meiying; Zhong, Guohua

2013-01-01

Mitochondria have been shown to play an important role in apoptosis using mammalian cell lines. However, this seems not to be the case in Drosophila, an insect model organism; thus more in-depth studies of insect cell apoptosis are necessary. In the present study, mitochondrial involvement during azadirachtin- and camptothecin-induced apoptosis in Spodoptera frugiperda Sf9 cells (isolated from Spodoptera frugiperda pupal ovarian tissue) was investigated. The results showed that both azadirachtin and camptothecin could induce apoptosis in Sf9 cells. Reactive oxygen species (ROS) generation, activation of mitochondrial permeability transition pores (MPTPs) and loss of mitochondrial membrane potential (MMP) were observed very early during apoptosis and were followed subsequently by the release of cytochrome-c from the mitochondria. Furthermore, the results also revealed that the opening of MPTPs and the loss of MMP induced by azadirachtin could be significantly inhibited by the permeability transition pore (PTP) inhibitor cyclosporin A (CsA), which was used to identify the key role of mitochondria in the apoptosis of Sf9 cells. However, in camptothecin-treated Sf9 cells, CsA could not suppress the opening of MPTPs and the loss of MMP when apoptosis was induced. The data from caspase-3 and caspase-9 activity assays and detection of apoptosis by morphological observation and flow cytometry also uncovered the different effect of CsA on the two botanical apoptosis inducers. Although different mechanisms of apoptosis induction exist, our study revealed that mitochondria play a crucial role in insect cell line apoptosis. PMID:23516491

Ketamine-induced apoptosis in the mouse cerebral cortex follows similar characteristic of physiological apoptosis and can be regulated by neuronal activity.

PubMed

Wang, Qi; Shen, Feng-Yan; Zou, Rong; Zheng, Jing-Jing; Yu, Xiang; Wang, Ying-Wei

2017-06-17

The effects of general anesthetics on inducing neuronal apoptosis during early brain development are well-documented. However, since physiological apoptosis also occurs during this developmental window, it is important to determine whether anesthesia-induced apoptosis targets the same cell population as physiological apoptosis or different cell types altogether. To provide an adequate plane of surgery, ketamine was co-administered with dexmedetomidine. The apoptotic neurons in the mouse primary somatosensory cortex (S1) were quantitated by immunohistochemistry. To explore the effect of neural activity on ketamine-induced apoptosis, the approaches of Designer Receptors Exclusively Activated by Designer Drugs (DREADDs) and an environmental enrichment (EE) were performed. Ketamine-induced apoptosis in S1 is most prominent at postnatal days 5 and 7 (P5 - P7), and becomes insignificant by P12. Physiological and ketamine-induced apoptosis follow similar developmental patterns, mostly comprised of layer V pyramidal neurons at P5 and shifting to mostly layer II to IV GABAergic neurons by P9. Changes in neuronal activity induced by the DREADD system bidirectionally regulated the pattern of ketamine-induced apoptosis, with reduced activity inducing increased apoptosis and shifting the lamination pattern to a more immature form. Importantly, rearing mice in an EE significantly reduced the magnitude of ketamine-induced apoptosis and shifted its developmental pattern to a more mature form. Together, these results demonstrate that lamination pattern and cell-type dependent vulnerability to ketamine-induced apoptosis follow the physiological apoptosis pattern and are age- and activity-dependent. Naturally elevating neuronal activity is a possible method for reducing the adverse effects of general anesthesia.

Tumor Necrosis Factor-related Apoptosis-inducing Ligand (TRAIL)-Troglitazone-induced Apoptosis in Prostate Cancer Cells Involve AMP-activated Protein Kinase*

PubMed Central

Santha, Sreevidya; Viswakarma, Navin; Das, Subhasis; Rana, Ajay; Rana, Basabi

2015-01-01

Prostate cancer (PCa) is one of the most frequently diagnosed cancers in men with limited treatment options for the hormone-resistant forms. Development of novel therapeutic options is critically needed to target advanced forms. Here we demonstrate that combinatorial treatment with the thiazolidinedione troglitazone (TZD) and TNF-related apoptosis-inducing ligand (TRAIL) can induce significant apoptosis in various PCa cells independent of androgen receptor status. Because TZD is known to activate AMP-activated protein kinase (AMPK), we determined whether AMPK is a molecular target mediating this apoptotic cascade by utilizing PCa cell lines stably overexpressing AMPKα1 dominant negative (C4-2-DN) or empty vector (C4-2-EV). Our results indicated a significantly higher degree of apoptosis with TRAIL-TZD combination in C4-2-EV cells compared with C4-2-DN cells. Similarly, results from a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay showed a larger reduction of viability of C4-2-EV cells compared with C4-2-DN cells when treated with TRAIL-TZD, thus suggesting that C4-2-DN cells were more apoptosis-resistant. Additionally, siRNA-mediated knockdown of endogenous AMPKα1 expression showed a reduction of TRAIL-TZD-induced apoptosis, further confirming the participation of AMPK in mediating this apoptosis. Apoptosis induction by this combinatorial treatment was also associated with a cleavage of β-catenin that was inhibited in both C4-2-DN cells and those cells in which AMPKα1 was knocked down. In addition, time course studies showed an increase in pACCS79 (AMPK target) levels coinciding with the time of apoptosis. These studies indicate the involvement of AMPK in TRAIL-TZD-mediated apoptosis and β-catenin cleavage and suggest the possibility of utilizing AMPK as a therapeutic target in apoptosis-resistant prostate cancer. PMID:26198640

White Tea Extract Induces Apoptosis in Nonsmall Cell Lung Cancer Cells– The Role of PPAR-γ and 15-Lipoxygenases

PubMed Central

Mao, Jenny T.; Nie, Wen-Xian; Tsu, I-Hsien; Jin, Yu-Sheng; Rao, Jian yu; Lu, Qing-Yi; Zhang, Zuo-Feng; Go, Vay Liang W.; Serio, Kenneth J.

2010-01-01

Purpose Emerging preclinical data suggests that tea possess anticarcinogenic and antimutagenic properties. We therefore hypothesize that white tea extract (WTE) is capable of favorably modulating apoptosis, a mechanism associated with lung tumorigenesis. Experimental Design We examined the effects of physiologically relevant doses of WTE on the induction of apoptosis in the nonsmall cell lung cancer (NSCLC) cell lines, A549 (adenocarcinoma) and H520 (squamous cell carcinoma) cells. We further characterized the molecular mechanisms responsible for the WTE-induced apoptosis, including the induction of PPAR-γ and the 15-lipoxygenase (15-LOX) signaling pathway. Results We found that WTE was effective in inducing apoptosis in both A549 and H520 cells, and inhibition of PPAR-γ with GW 9662 partially reversed the WTE-induced apoptosis. We further demonstrate that WTE increased PPAR-γ activation and mRNA expression, concomitantly increased 15-HETE release, and up-regulated 15-LOX-1 and 2 mRNA expression by A549 cells. Inhibition of 15-LOX with NGDA, as well as caffeic acid, abrogated the WTE-induced PPAR-γ activation and up-regulation of PPAR-γ mRNA expression in A549 cells. WTE also induced cyclin-dependent kinase inhibitor 1A (CDKN1A) mRNA expression and activated caspase 3. Inhibition of caspase 3 abrogated the WTE-induced apoptosis. Conclusions Our findings indicate that WTE is capable of inducing apoptosis in NSCLC cell lines. The induction of apoptosis appears to be mediated, in part, through the up-regulation of the PPAR-γ and 15-LOX signaling pathways, with enhanced activation of caspase 3. Our findings support the future investigation of WTE as an antineoplastic and chemopreventive agent for lung cancer. PMID:20668019

Apigenin induces apoptosis by targeting inhibitor of apoptosis proteins and Ku70–Bax interaction in prostate cancer

PubMed Central

Shukla, Sanjeev; Fu, Pingfu; Gupta, Sanjay

2014-01-01

Dysfunction of the apoptotic pathway in prostate cancer cells confers apoptosis resistance towards various therapies. A novel strategy to overcome resistance is to directly target the apoptotic pathway in cancer cells. Apigenin, an anticancer agent, selectively toxic to cancer cells induces cell cycle arrest and apoptosis through mechanisms which are not fully explored. In the present study we provide novel insight into the mechanisms of apoptosis induction by apigenin. Treatment of androgen-refractory human prostate cancer PC-3 and DU145 cells with apigenin resulted in dose-dependent suppression of XIAP, c-IAP1, c-IAP2 and survivin protein levels. Apigenin treatment resulted in significant decrease in cell viability and apoptosis induction with the increase of cytochrome C in time-dependent manner. These effects of apigenin were accompanied by decrease in Bcl-xL and Bcl-2 and increase in the active form of Bax protein. The apigenin-mediated increase in Bax was due to dissociation of Bax from Ku70 which is essential for apoptotic activity of Bax. Apigenin treatment resulted in the inhibition of class I histone deacetylases and HDAC1 protein expression, thereby increasing the acetylation of Ku70 and the dissociation of Bax resulting in apoptosis of cancer cells. Furthermore, apigenin significantly reduced HDAC1 occupancy at the XIAP promoter, suggesting that histone deacetylation might be critical for XIAP downregulation. These results suggest that apigenin targets inhibitor of apoptosis proteins and Ku70–Bax interaction in the induction of apoptosis in prostate cancer cells and in athymic nude mouse xenograft model endorsing its in vivo efficacy. PMID:24563225

Verocytotoxin-induced apoptosis of human microvascular endothelial cells.

PubMed

Pijpers, A H; van Setten, P A; van den Heuvel, L P; Assmann, K J; Dijkman, H B; Pennings, A H; Monnens, L A; van Hinsbergh, V W

2001-04-01

The pathogenesis of the epidemic form of hemolytic uremic syndrome is characterized by endothelial cell damage. In this study, the role of apoptosis in verocytotoxin (VT)-mediated endothelial cell death in human glomerular microvascular endothelial cells (GMVEC), human umbilical vein endothelial cells, and foreskin microvascular endothelial cells (FMVEC) was investigated. VT induced apoptosis in GMVEC and human umbilical vein endothelial cells when the cells were prestimulated with the inflammatory mediator tumor necrosis factor-alpha (TNF-alpha). FMVEC displayed strong binding of VT and high susceptibility to VT under basal conditions, which made them suitable for the study of VT-induced apoptosis without TNF-alpha interference. On the basis of functional (flow cytometry and immunofluorescence microscopy using FITC-conjugated annexin V and propidium iodide), morphologic (transmission electron microscopy), and molecular (agarose gel electrophoresis of cellular DNA fragments) criteria, it was documented that VT induced programmed cell death in microvascular endothelial cells in a dose- and time-dependent manner. Furthermore, whereas partial inhibition of protein synthesis by VT was associated with a considerable number of apoptotic cells, comparable inhibition of protein synthesis by cycloheximide was not. This suggests that additional pathways, independent of protein synthesis inhibition, may be involved in VT-mediated apoptosis in microvascular endothelial cells. Specific inhibition of caspases by Ac-Asp-Glu-Val-Asp-CHO, but not by Ac-Tyr-Val-Ala-Asp-CHO, was accompanied by inhibition of VT-induced apoptosis in FMVEC and TNF-alpha-treated GMVEC. These data indicate that VT can induce apoptosis in human microvascular endothelial cells.

Capsaicin Induces Autophagy and Apoptosis in Human Nasopharyngeal Carcinoma Cells by Downregulating the PI3K/AKT/mTOR Pathway.

PubMed

Lin, Yu-Tsai; Wang, Hung-Chen; Hsu, Yi-Chiang; Cho, Chung-Lung; Yang, Ming-Yu; Chien, Chih-Yen

2017-06-23

Capsaicin is a potential chemotherapeutic agent for different human cancers. In Southeast China, nasopharyngeal carcinoma (NPC) has the highest incidence of all cancers, but final treatment outcomes are unsatisfactory. However, there is a lack of information regarding the anticancer activity of capsaicin in NPC cells, and its effects on the signaling transduction pathways related to apoptosis and autophagy remain unclear. In the present study, the precise mechanisms by which capsaicin exerts anti-proliferative effects, cell cycle arrest, autophagy and apoptosis were investigated in NPC-TW01 cells. Exposure to capsaicin inhibited cancer cell growth and increased G1 phase cell cycle arrest. Western blotting and quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) were used to measure capsaicin-induced autophagy via involvement of the class III PI3K/Beclin-1/Bcl-2 signaling pathway. Capsaicin induced autophagy by increasing levels of the autophagy markers LC3-II and Atg5, enhancing p62 and Fap-1 degradation and increasing caspase-3 activity to induce apoptosis, suggesting a correlation of blocking the PI3K/Akt/mTOR pathway with the above-mentioned anticancer activities. Taken together, these data confirm that capsaicin inhibited the growth of human NPC cells and induced autophagy, supporting its potential as a therapeutic agent for cancer.

Ketamine-induced apoptosis in cultured rat cortical neurons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Takadera, Tsuneo; Ishida, Akira; Ohyashiki, Takao

2006-01-15

Recent data suggest that anesthetic drugs cause neurodegeneration during development. Ketamine is frequently used in infants and toddlers for elective surgeries. The purpose of this study is to determine whether glycogen synthase kinase-3 (GSK-3) is involved in ketamine-induced apoptosis. Ketamine increased apoptotic cell death with morphological changes which were characterized by cell shrinkage, nuclear condensation or fragmentation. In addition, insulin growth factor-1 completely blocked the ketamine-induced apoptotic cell death. Ketamine decreased Akt phosphorylation. GSK-3 is known as a downstream target of Akt. The selective inhibitors of GSK-3 prevented the ketamine-induced apoptosis. Moreover, caspase-3 activation was accompanied by the ketamine-induced cellmore » death and inhibited by the GSK-3 inhibitors. These results suggest that activation of GSK-3 is involved in ketamine-induced apoptosis in rat cortical neurons.« less

Inhibition of N-methyl-D-aspartate receptors increases paraoxon-induced apoptosis in cultured neurons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu Xuan; Tian Feng; Okagaki, Peter

2005-10-01

Organophosphorus (OP) compounds, used as insecticides and chemical warfare agents, are potent neurotoxins. We examined the neurotoxic effect of paraoxon (O,O-diethyl O-p-nitrophenyl phosphate), an organophosphate compound, and the role of NMDA receptors as a mechanism of action in cultured cerebellar granule cells. Paraoxon is neurotoxic to cultured rat cerebellar granule cells in a time- and concentration-dependent manner. Cerebellar granule cells are less sensitive to the neurotoxic effects of paraoxon on day in vitro (DIV) 4 than neurons treated on DIV 8. Surprisingly, the N-methyl-D-aspartate (NMDA) receptor antagonist, MK-801, enhances paraoxon-mediated neurotoxicity suggesting that NMDA receptors may play a protective role.more » Pretreatment with a subtoxic concentration of N-methyl-D-aspartate (NMDA) [100 {mu}M] protects about 40% of the vulnerable neurons that would otherwise die from paraoxon-induced neurotoxicity. Moreover, addition of a neuroprotective concentration of NMDA 3 h after treatment with paraoxon provides the same level of protection. Because paraoxon-mediated neuronal cell death is time-dependent, we hypothesized that apoptosis may be involved. Paraoxon increases apoptosis about 10-fold compared to basal levels. The broad-spectrum caspase inhibitor (Boc-D-FMK) and the caspase-9-specific inhibitor (Z-LEHD-FMK) protect against paraoxon-mediated apoptosis, paraoxon-stimulated caspase-3 activity and neuronal cell death. MK-801 increases, whereas NMDA blocks paraoxon-induced apoptosis and paraoxon-stimulated caspase-3 activity. These results suggest that activation of NMDA receptors protect neurons against paraoxon-induced neurotoxicity by blocking apoptosis initiated by paraoxon.« less

Inhibition of cyclooxygenase-2-dependent survivin mediates decursin-induced apoptosis in human KBM-5 myeloid leukemia cells

PubMed Central

Ahn, Quein; Jeong, Soo-Jin; Lee, Hyo-Jung; Kwon, Hee-Young; Han, Ihn; Kim, Hyun Seok; Lee, Hyo-Jeong; Lee, Eun-Ok; Ahn, Kwang Seok; Jung, Min-Hyung; Zhu, Shudong; Chen, Chang-Yan; Kim, Sung-Hoon

2013-01-01

We demonstrate that decursin induces apoptosis via regulation of cyclooxygenase-2 (COX-2) and survivin in leukemic KBM-5 cells. By activating an apoptotic machinery, decursin is cytotoxic to KBM-5 cells. In this apoptotic process, decursin can activate caspase family members and triggers PARP cleavage. At the same time, the expression of COX-2 and survivin in the cells is downregulated. Furthermore, decursin is in synergy with COX-2 inhibitor, celecoxib or NS398 for the induction of apoptosis. Overall, these results suggest that decursin, via inhibiting COX-2 and survivin, sensitizes human leukemia cells to apoptosis and is a potential chemotherapeutic agent to treat this disease. PMID:20673699

TSA-induced JMJD2B downregulation is associated with cyclin B1-dependent survivin degradation and apoptosis in LNCap cells.

PubMed

Zhu, Shan; Li, Yueyang; Zhao, Li; Hou, Pingfu; Shangguan, Chenyan; Yao, Ruosi; Zhang, Weina; Zhang, Yu; Tan, Jiang; Huang, Baiqu; Lu, Jun

2012-07-01

Histone deacetylase (HDAC) inhibitors are emerging as a novel class of anti-tumor agents and have manifested the ability to induce apoptosis of cancer cells, and a significant number of genes have been identified as potential effectors responsible for HDAC inhibitor-induced apoptosis. However, the mechanistic actions of these HDAC inhibitors in this process remain largely undefined. We here report that the treatment of LNCap prostate cancer cells with HDAC inhibitor trichostatin A (TSA) resulted in downregulation of the Jumonji domain-containing protein 2B (JMJD2B). We also found that the TSA-mediated decrease in survivin expression in LNCap cells was partly attributable to downregulation of JMJD2B expression. This effect was attributable to the promoted degradation of survivin protein through inhibition of Cyclin B1/Cdc2 complex-mediated survivin Thr34 phosphorylation. Consequently, knockdown of JMJD2B enhanced TSA-induced apoptosis by regulating the Cyclin B1-dependent survivin degradation to potentiate the apoptosis pathways. Copyright © 2012 Wiley Periodicals, Inc.

Troglitazone induced apoptosis via PPARγ activated POX-induced ROS formation in HT29 cells.

PubMed

Wang, Jing; Lv, XiaoWen; Shi, JiePing; Hu, XiaoSong; DU, YuGuo

2011-08-01

In order to investigate the potential mechanisms in troglitazone-induced apoptosis in HT29 cells, the effects of PPARγ and POX-induced ROS were explored. [3- (4, 5)-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide (MTT) assay, Annexin V and PI staining using FACS, plasmid transfection, ROS formation detected by DCFH staining, RNA interference, RT-PCR & RT-QPCR, and Western blotting analyses were employed to investigate the apoptotic effect of troglitazone and the potential role of PPARγ pathway and POX-induced ROS formation in HT29 cells. Troglitazone was found to inhibit the growth of HT29 cells by induction of apoptosis. During this process, mitochondria related pathways including ROS formation, POX expression and cytochrome c release increased, which were inhibited by pretreatment with GW9662, a specific antagonist of PPARγ. These results illustrated that POX upregulation and ROS formation in apoptosis induced by troglitazone was modulated in PPARγ-dependent pattern. Furthermore, the inhibition of ROS and apoptosis after POX siRNA used in troglitazone-treated HT29 cells indicated that POX be essential in the ROS formation and PPARγ-dependent apoptosis induced by troglitazone. The findings from this study showed that troglitazone-induced apoptosis was mediated by POX-induced ROS formation, at least partly, via PPARγ activation. Copyright © 2011 The Editorial Board of Biomedical and Environmental Sciences. Published by Elsevier B.V. All rights reserved.

A novel anticancer agent, decursin, induces G1 arrest and apoptosis in human prostate carcinoma cells.

PubMed

Yim, Dongsool; Singh, Rana P; Agarwal, Chapla; Lee, Sookyeon; Chi, Hyungjoon; Agarwal, Rajesh

2005-02-01

We isolated a coumarin compound decursin (C(19)H(20)O(5); molecular weight 328) from Korean angelica (Angelica gigas) root and characterized it by spectroscopy. Here, for the first time, we observed that decursin (25-100 micromol/L) treatment for 24 to 96 hours strongly inhibits growth and induces death in human prostate carcinoma DU145, PC-3, and LNCaP cells. Furthermore, we observed that decursinol [where (CH(3))(2)-C=CH-COO- side chain of decursin is substituted with -OH] has much lower effects compared with decursin, suggesting a possible structure-activity relationship. Decursin-induced growth inhibition was associated with a strong G(1) arrest (P < 0.001) in DU145 and LNCaP cells, and G(1), S as well as G(2)-M arrests depending upon doses and treatment times in PC-3 cells. Comparatively, decursin was nontoxic to human prostate epithelial PWR-1E cells and showed only moderate growth inhibition and G(1) arrest. Consistent with G(1) arrest in DU145 cells, decursin strongly increased protein levels of Cip1/p21 but showed a moderate increase in Kip1/p27 with a decrease in cyclin-dependent kinases (CDK); CDK2, CDK4, CDK6, and cyclin D1, and inhibited CDK2, CDK4, CDK6, cyclin D1, and cyclin E kinase activity, and increased binding of CDK inhibitor (CDKI) with CDK. Decursin-caused cell death was associated with an increase in apoptosis (P < 0.05-0.001) and cleaved caspase-9, caspase-3, and poly(ADP-ribose) polymerase; however, pretreatment with all-caspases inhibitor (z-VAD-fmk) only partially reversed decursin-induced apoptosis, suggesting the involvement of both caspase-dependent and caspase-independent pathways. These findings suggest the novel anticancer efficacy of decursin mediated via induction of cell cycle arrest and apoptosis selectively in human prostate carcinoma cells.

[Advances in Parvovirus Non-structural Protein NS1 Induced Apoptosis].

PubMed

Tu, Mengyu; Liu, Fei; Chen, Shun; Wang, Mingshu; Cheng, Anchun

2015-11-01

Until now, more than seventeen parvovirus have been reported which can infect mammals and poultries. The infected cells appeared different properties of apoptosis and death, present a typical cytopathic effect. NS1 is a major nonstructural protein of parvovirus, with a conservative structure and function, which plays an important role in the viral life cycle. In addition to the influence on viral replication, the NS1 also participates in apoptosis induced by viruses. Parvovirus induced apoptosis which is mainly mediated by mitochondrial pathway, this review summarized the latest research progresses of parvovirus induced apoptosis.

EF24, a novel synthetic curcumin analog, induces apoptosis in cancer cells via a redox-dependent mechanism.

PubMed

Adams, Brian K; Cai, Jiyang; Armstrong, Jeff; Herold, Marike; Lu, Yang J; Sun, Aiming; Snyder, James P; Liotta, Dennis C; Jones, Dean P; Shoji, Mamoru

2005-03-01

In this study, we show that the novel synthetic curcumin analog, EF24, induces cell cycle arrest and apoptosis by means of a redox-dependent mechanism in MDA-MB-231 human breast cancer cells and DU-145 human prostate cancer cells. Cell cycle analysis demonstrated that EF24 causes a G2/M arrest in both cell lines, and that this cell cycle arrest is followed by the induction of apoptosis as evidenced by caspase-3 activation, phosphatidylserine externalization and an increased number of cells with a sub-G1 DNA fraction. In addition, we demonstrate that EF24 induces a depolarization of the mitochondrial membrane potential, suggesting that the compound may also induce apoptosis by altering mitochondrial function. EF24, like curcumin, serves as a Michael acceptor reacting with glutathione (GSH) and thioredoxin 1. Reaction of EF24 with these agents in vivo significantly reduced intracellular GSH as well as oxidized GSH in both the wild-type and Bcl-xL overexpressing HT29 human colon cancer cells. We therefore propose that the anticancer effect of a novel curcumin analog, EF24, is mediated in part by redox-mediated induction of apoptosis.

Neuroprotective Effects of 17β-Estradiol against Thrombin-Induced Apoptosis in Primary Cultured Cortical Neurons.

PubMed

Bao, Lei; Zhou, Su; Zhao, Hui; Zu, Jie; He, Qianqian; Ye, Xinchun; Cui, Guiyun

2015-01-01

17β-estradiol (E2) is a powerful neuroprotective agent in the central nervous system; however, little is known about its effects on intracerebral hemorrhage. This study examined the effects of E2 on thrombin-induced apoptosis in vitro and investigated the potential mechanisms. Primary cultured cortical neurons were treated with E2 or vehicle and then the cells were exposed to thrombin. Neuronal apoptosis was assessed by flow cytometry. The phosphorylated c-Jun-N-terminal kinase (p-JNK), phosphorylated extracellular signal-regulated kinases 1/2 (p-ERK1/2), B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X protein (Bax) and caspase-3 were assayed by western blot. Consequently, we found that E2 has significantly reduced the apoptosis in thrombin-treated neurons. E2 also exhibited a downregulation in the ratio of Bax/Bcl-2, caspase-3 and p-JNK. However, E2 had little effect on p-ERK1/2 proteins activation. Taken together, E2 has shown neuroprotective effects on thrombin-induced neuronal apoptosis, and the molecular mechanisms may correlate with the inhibition of the JNK signaling pathway. © 2015 S. Karger AG, Basel.

GSK-3β mediates dexamethasone-induced pancreatic β cell apoptosis

PubMed Central

Guo, Bin; Zhang, Wenjian; Xu, Shiqing; Lou, Jinning; Wang, Shuxia; Men, Xiuli

2015-01-01

Aims Glucocorticoids, such as dexamethasone, are widely used anti-inflammatory drugs. Their use is frequently associated with the development of steroid- associated diabetes. Pancreatic β-cell dysfunction has been suggested to be one of the main causes of steroid-associated diabetes. However, the mechanism is not fully understood. Glycogen synthase kinase-3β (GSK-3β) is a multifunctional serine/threonine kinase and plays an important role in energy metabolism, cell growth and apoptosis. Therefore, the contribution of GSK-3β in dexamethasone-induced pancreatic β-cell apoptosis was determined in the present study. Main Methods The effect of dexamethasone treatment on rat pancreatic β-cell line (INS-1) apoptosis (determined by TUNEL and Flow Cytometry), generation of reactive oxidative stress (ROS), and the phosphorylation status of GSK-3β was determined. The inhibitory effect of GSK-3β inhibitor-lithium chloride (LiCl) on dexamethasone-induced β-cell apoptosis was also evaluated. Key Findings Dexamethasone (0.1 μM) treatment induced INS-1 apoptosis, which was associated with increased GSK-3β activation and increased NOX4-derived ROS generation. Pretreatment of INS-1 with LiCl inhibited dexamethasone induced ROS generation and INS-1 apoptosis. Significance This study provides a new mechanism of Dex induced pancreatic β cell apoptosis and may serve as a new therapeutic option for treating GCs induced diabetes. PMID:26606859

Prostaglandin E2 blocks menadione-induced apoptosis through the Ras/Raf/Erk signaling pathway in promonocytic leukemia cell lines.

PubMed

Yeo, Hyun-Seok; Shehzad, Adeeb; Lee, Young Sup

2012-04-01

Altered oxidative stress has long been observed in cancer cells, and this biochemical property of cancer cells represents a specific vulnerability that can be exploited for therapeutic benefit. The major role of an elevated oxidative stress for the efficacy of molecular targeted drugs is under investigation. Menadione is considered an attractive model for the study of oxidative stress, which can induce apoptosis in human leukemia HL-60 cell lines. Prostaglandin E(2) (PGE(2)) via its receptors not only promotes cell survival but also reverses apoptosis and promotes cancer progression. Here, we present evidence for the biological role of PGE(2) as a protective agent of oxidative stress-induced apoptosis in monocytic cells. Pretreatment of HL-60 cells with PGE(2) markedly ameliorated the menadione-induced apoptosis and inhibited the degradation of PARP and lamin B. The EP(2) receptor antagonist AH6809 abrogated the inhibitory effect of PGE(2), suggesting the role of the EP(2)/cAMP system. The PKA inhibitor H89 also reversed apoptosis and decreased the PKA activity that was elevated 10-fold by PGE(2). The treatment of HL-60 cells with NAC or zinc chloride showed a similar protective effect as with PGE(2) on menadione-treated cells. Furthermore, PGE(2) activated the Ras/Raf/MEK pathway, which in turn initiated ERK activation, and ultimately protected menadione-induced apoptosis. These results imply that PGE(2) via cell survival pathways may protect oxidative stress-induced apoptosis in monocytic cells. This study warrants further pre-clinical investigation as well as application towards leukemia clinics.

Prostaglandin E2 Blocks Menadione-Induced Apoptosis through the Ras/Raf/Erk Signaling Pathway in Promonocytic Leukemia Cell Lines

PubMed Central

Yeo, Hyun-Seok; Shehzad, Adeeb; Lee, Young Sup

2012-01-01

Altered oxidative stress has long been observed in cancer cells, and this biochemical property of cancer cells represents a specific vulnerability that can be exploited for therapeutic benefit. The major role of an elevated oxidative stress for the efficacy of molecular targeted drugs is under investigation. Menadione is considered an attractive model for the study of oxidative stress, which can induce apoptosis in human leukemia HL-60 cell lines. Prostaglandin E2 (PGE2) via its receptors not only promotes cell survival but also reverses apoptosis and promotes cancer progression. Here, we present evidence for the biological role of PGE2 as a protective agent of oxidative stress-induced apoptosis in monocytic cells. Pretreatment of HL-60 cells with PGE2 markedly ameliorated the menadione-induced apoptosis and inhibited the degradation of PARP and lamin B. The EP2 receptor antagonist AH6809 abrogated the inhibitory effect of PGE2, suggesting the role of the EP2/cAMP system. The PKA inhibitor H89 also reversed apoptosis and decreased the PKA activity that was elevated 10-fold by PGE2. The treatment of HL-60 cells with NAC or zinc chloride showed a similar protective effect as with PGE2 on menadione-treated cells. Furthermore, PGE2 activated the Ras/Raf/MEK pathway, which in turn initiated ERK activation, and ultimately protected menadione-induced apoptosis. These results imply that PGE2 via cell survival pathways may protect oxidative stress-induced apoptosis in monocytic cells. This study warrants further pre-clinical investigation as well as application towards leukemia clinics. PMID:22450688

Fluid shear stress sensitizes cancer cells to receptor-mediated apoptosis via trimeric death receptors

NASA Astrophysics Data System (ADS)

Mitchell, Michael J.; King, Michael R.

2013-01-01

Cancer metastasis, the process of cancer cell migration from a primary to distal location, typically leads to a poor patient prognosis. Hematogenous metastasis is initiated by intravasation of circulating tumor cells (CTCs) into the bloodstream, which are then believed to adhere to the luminal surface of the endothelium and extravasate into distal locations. Apoptotic agents such as tumor necrosis factor apoptosis-inducing ligand (TRAIL), whether in soluble ligand form or expressed on the surface of natural killer cells, have shown promise in treating CTCs to reduce the probability of metastasis. The role of hemodynamic shear forces in altering the cancer cell response to apoptotic agents has not been previously investigated. Here, we report that human colon cancer COLO 205 and prostate cancer PC-3 cells exposed to a uniform fluid shear stress in a cone-and-plate viscometer become sensitized to TRAIL-induced apoptosis. Shear-induced sensitization directly correlates with the application of fluid shear stress, and TRAIL-induced apoptosis increases in a fluid shear stress force- and time-dependent manner. In contrast, TRAIL-induced necrosis is not affected by the application fluid shear stress. Interestingly, fluid shear stress does not sensitize cancer cells to apoptosis when treated with doxorubicin, which also induces apoptosis in cancer cells. Caspase inhibition experiments reveal that shear stress-induced sensitization to TRAIL occurs via caspase-dependent apoptosis. These results suggest that physiological fluid shear forces can modulate receptor-mediated apoptosis of cancer cells in the presence of apoptotic agents.

Mentha piperita as a pivotal neuro-protective agent against gamma irradiation induced DNA fragmentation and apoptosis : Mentha extract as a neuroprotective against gamma irradiation.

PubMed

Hassan, Hanaa A; Hafez, Hani S; Goda, Mona S

2013-01-01

Ionizing radiation is classified as a potent carcinogen, and its injury to living cells, in particular to DNA, is due to oxidative stress enhancing apoptotic cell death. Our present study aimed to characterize and semi-quantify the radiation-induced apoptosis in CNS and the activity of Mentha extracts as neuron-protective agent. Our results through flow cytometry exhibited the significant disturbance and arrest in cell cycle in % of M1: SubG1 phase, M2: G0/1 phase of diploid cycle, M3: S phase and M4: G2/M phase of cell cycle in brain tissue (p < 0.05). Significant increase in % of apoptosis and P53 protein expression as apoptotic biomarkers were coincided with significant decrease in Bcl(2) as an anti-apoptotic marker. The biochemical analysis recorded a significant decrease in the levels of reduced glutathione, superoxide dismutase, deoxyribonucleic acid (DNA) and ribonucleic acid contents. Moreover, numerous histopathological alterations were detected in brain tissues of gamma irradiated mice such as signs of chromatolysis in pyramidal cells of cortex, nuclear vacuolation, numerous apoptotic cell, and neural degeneration. On the other hand, gamma irradiated mice pretreated with Mentha extract showed largely an improvement in all the above tested parameters through a homeostatic state for the content of brain apoptosis and stabilization of DNA cycle with a distinct improvement in cell cycle analysis and antioxidant defense system. Furthermore, the aforementioned effects of Mentha extracts through down-regulation of P53 expression and up-regulation of Bcl(2) domain protected brain structure from extensive damage. Therefore, Mentha extract seems to have a significant role to ameliorate the neuronal injury induced by gamma irradiation.

Overexpression of BAG3 Attenuates Hypoxia-Induced Cardiomyocyte Apoptosis by Inducing Autophagy.

PubMed

Zhang, Jiankai; He, Zhangyou; Xiao, Wenjian; Na, Qingqing; Wu, Tianxiu; Su, Kaixin; Cui, Xiaojun

2016-01-01

Hypoxia is a well-known factor in the promotion of apoptosis, which contributes to the development of numerous cardiac diseases, such as heart failure and myocardial infarction. Inhibiting apoptosis is an important therapeutic strategy for the treatment of related heart diseases caused by ischemia/hypoxic injury. Previous studies have demonstrated that BAG3 plays an important role in cardiomyocyte apoptosis and survival. However, the role of BAG3 in hypoxia-induced cardiomyocyte apoptosis remains to be clarified. Here, we demonstrate that BAG3 is induced by hypoxia stimuli in cultured cardiomyocytes. BAG3 expression level was measured in H9c2 cells treated with hypoxia for 48 h. Cell proliferation and apoptosis were tested using MTT assay and Annexin V FITC-PI staining assay, respectively. The mRNA or protein expression level of BAG3, LC3-I, LC3-II, Atg5, NF-x03BA;B p65 and phosphorylated NF-x03BA;B p65 were assessed by qRT-PCR and western blot assay, respectively. Resluts: Overexpression of BAG3 inhibited cell apoptosis and promoted proliferation in hypoxia-injured H9c2 cells. Furthermore, autophagy and NF-x03BA;B were activated by BAG3 overexpression, and the NF-x03BA;B inhibitor PDTC could inhibit the activation of autophagy induced by BAG3 overexpression. In addition, the autophagy inhibitor 3-MA partly impeded the inhibitory effect of BAG3 on hypoxia-induced cardiomyocyte apoptosis. these results suggested that overexpression of BAG3 promoted cell proliferation and inhibited apoptosis by activating autophagy though the NF-x03BA;B signaling pathway in hypoxia-injured cardiomyocytes. © 2016 The Author(s) Published by S. Karger AG, Basel.

Soluble Prokaryotic Expression and Purification of Bioactive Tumor Necrosis Factor-Related Apoptosis-Inducing Ligand.

PubMed

Do, Bich Hang; Nguyen, Minh Tan; Song, Jung-A; Park, Sangsu; Yoo, Jiwon; Jang, Jaepyeong; Lee, Sunju; So, Seoungjun; Yoon, Yejin; Kim, Inki; Lee, Kyungjin; Jang, Yeon Jin; Choe, Han

2017-12-28

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is considered as an antitumor agent owing to its ability to induce apoptosis of cancer cells without imparting toxicity toward most normal cells. TRAIL is produced in poor yield because of its insoluble expression in the cytoplasm of E. coli . In this study, we achieved soluble expression of TRAIL by fusing maltose-binding protein (MBP), b'a' domain of protein disulfide isomerase (PDIb'a'), or protein disulfide isomerase at the N-terminus of TRAIL. The TRAIL was purified using subsequent immobilized metal affinity chromatography and amylose-binding chromatography, with the tag removal using tobacco etch virus protease. Approximately 4.5 mg of pure TRAIL was produced from 125 ml flask culture with a purification yield of 71.6%. The endotoxin level of the final product was 0.4 EU/μg, as measured by the Limulus amebocyte lysate endotoxin assay. The purified TRAIL was validated and shown to cause apoptosis of HeLa cells with an EC₅₀ and Hill coefficient of 0.6 ± 0.03 nM and 2.41 ± 0.15, respectively. The high level of apoptosis in HeLa cells following administration of purified TRAIL indicates the significance and novelty of this method for producing high-grade and high-yield TRAIL.

Apoptosis and Self-Destruct: A Contribution to Autonomic Agents?

NASA Technical Reports Server (NTRS)

Sterritt, Roy; Hinchey, Mike

2004-01-01

Autonomic Computing (AC), a self-managing systems initiative based on the biological metaphor of the autonomic nervous system, is increasingly gaining momentum as the way forward in designing reliable systems. Agent technologies have been identified as a key enabler for engineering autonomicity in systems, both in terms of retrofitting autonomicity into legacy systems and designing new systems. The AC initiative provides an opportunity to consider other biological systems and principles in seeking new design strategies. This paper reports on one such investigation; utilizing the apoptosis metaphor of biological systems to provide a dynamic health indicator signal between autonomic agents.

Hypoxia-induced p53 modulates both apoptosis and radiosensitivity via AKT.

PubMed

Leszczynska, Katarzyna B; Foskolou, Iosifina P; Abraham, Aswin G; Anbalagan, Selvakumar; Tellier, Céline; Haider, Syed; Span, Paul N; O'Neill, Eric E; Buffa, Francesca M; Hammond, Ester M

2015-06-01

Restoration of hypoxia-induced apoptosis in tumors harboring p53 mutations has been proposed as a potential therapeutic strategy; however, the transcriptional targets that mediate hypoxia-induced p53-dependent apoptosis remain elusive. Here, we demonstrated that hypoxia-induced p53-dependent apoptosis is reliant on the DNA-binding and transactivation domains of p53 but not on the acetylation sites K120 and K164, which, in contrast, are essential for DNA damage-induced, p53-dependent apoptosis. Evaluation of hypoxia-induced transcripts in multiple cell lines identified a group of genes that are hypoxia-inducible proapoptotic targets of p53, including inositol polyphosphate-5-phosphatase (INPP5D), pleckstrin domain-containing A3 (PHLDA3), sulfatase 2 (SULF2), B cell translocation gene 2 (BTG2), cytoplasmic FMR1-interacting protein 2 (CYFIP2), and KN motif and ankyrin repeat domains 3 (KANK3). These targets were also regulated by p53 in human cancers, including breast, brain, colorectal, kidney, bladder, and melanoma cancers. Downregulation of these hypoxia-inducible targets associated with poor prognosis, suggesting that hypoxia-induced apoptosis contributes to p53-mediated tumor suppression and treatment response. Induction of p53 targets, PHLDA3, and a specific INPP5D transcript mediated apoptosis in response to hypoxia through AKT inhibition. Moreover, pharmacological inhibition of AKT led to apoptosis in the hypoxic regions of p53-deficient tumors and consequently increased radiosensitivity. Together, these results identify mediators of hypoxia-induced p53-dependent apoptosis and suggest AKT inhibition may improve radiotherapy response in p53-deficient tumors.

Hypoxia-induced p53 modulates both apoptosis and radiosensitivity via AKT

PubMed Central

Leszczynska, Katarzyna B.; Foskolou, Iosifina P.; Abraham, Aswin G.; Anbalagan, Selvakumar; Tellier, Céline; Haider, Syed; Span, Paul N.; O’Neill, Eric E.; Buffa, Francesca M.; Hammond, Ester M.

2015-01-01

Restoration of hypoxia-induced apoptosis in tumors harboring p53 mutations has been proposed as a potential therapeutic strategy; however, the transcriptional targets that mediate hypoxia-induced p53-dependent apoptosis remain elusive. Here, we demonstrated that hypoxia-induced p53-dependent apoptosis is reliant on the DNA-binding and transactivation domains of p53 but not on the acetylation sites K120 and K164, which, in contrast, are essential for DNA damage–induced, p53-dependent apoptosis. Evaluation of hypoxia-induced transcripts in multiple cell lines identified a group of genes that are hypoxia-inducible proapoptotic targets of p53, including inositol polyphosphate-5-phosphatase (INPP5D), pleckstrin domain–containing A3 (PHLDA3), sulfatase 2 (SULF2), B cell translocation gene 2 (BTG2), cytoplasmic FMR1-interacting protein 2 (CYFIP2), and KN motif and ankyrin repeat domains 3 (KANK3). These targets were also regulated by p53 in human cancers, including breast, brain, colorectal, kidney, bladder, and melanoma cancers. Downregulation of these hypoxia-inducible targets associated with poor prognosis, suggesting that hypoxia-induced apoptosis contributes to p53-mediated tumor suppression and treatment response. Induction of p53 targets, PHLDA3, and a specific INPP5D transcript mediated apoptosis in response to hypoxia through AKT inhibition. Moreover, pharmacological inhibition of AKT led to apoptosis in the hypoxic regions of p53-deficient tumors and consequently increased radiosensitivity. Together, these results identify mediators of hypoxia-induced p53-dependent apoptosis and suggest AKT inhibition may improve radiotherapy response in p53-deficient tumors. PMID:25961455

Stem bromelain-induced macrophage apoptosis and activation curtail Mycobacterium tuberculosis persistence.

PubMed

Mahajan, Sahil; Chandra, Vemika; Dave, Sandeep; Nanduri, Ravikanth; Gupta, Pawan

2012-08-01

Mycobacterium tuberculosis, the causative agent of tuberculosis, has a remarkable ability to usurp its host's innate immune response, killing millions of infected people annually. One approach to manage infection is prevention through the use of natural agents. In this regard, stem bromelain (SBM), a pharmacologically active member of the sulfhydryl proteolytic enzyme family, obtained from Ananas comosus and possessing a remarkable ability to induce the innate and acquired immune systems, is important. We evaluated SBM's ability to induce apoptosis and free-radical generation in macrophages. We also studied antimycobacterial properties of SBM and its effect on foamy macrophages. SBM treatment of peritoneal macrophages resulted in the upregulation of proapoptotic proteins and downregulation of antiapoptotic proteins. Additionally, SBM treatment activated macrophages, curtailed the levels of free glutathione, and augmented the production of hydrogen peroxide, superoxide anion, peroxynitrite, and nitric oxide. SBM cleaves CD36 and reduced the formation of foam cells, the hallmark of M. tuberculosis infection. These conditions created an environment for the increased clearance of M. tuberculosis. Together these data provide a mechanism for antimycobacterial activity of SBM and provide important insights for the use of cysteine proteases as immunomodulatory agents.

[Endoplasmic reticulum stress mediates lipopolysaccharide-induced apoptosis in rat hepatocyte].

PubMed

Ji, Ying-Lei; Yan, Jun; Wang, Yan-Sha; Liu, Yi-Chang; Gu, Zhen-Yong

2014-02-01

To investigate the role of endoplasmic reticulum stress (ERS) in lipopolysaccharide (LPS)-induced hepatocyte apoptosis. Cells of the rat hepatocyte line BRL were cultured. The hepatocytes were treated with LPS, ERS inducer thapsigargin (TG), and ERS inhibitor 4-phenylbutyric acid (4-PBA), respectively or in their different combination. The cell viability was measured by MTT assay. The cyto-nuclear morphological changes of apoptosis cells were detected by the fluorescent dye Hoechst 33258. The apoptosis rate was assessed by flow cytometry with Annexin V-FITC/PI double-staining. Expressions of GRP78 as ERS marker protein, CHOP, caspase-12 and cleaved-caspase-3 as ERS related protein were detected by Western blotting. LPS could cause a decrease in cell viability and an increase in apoptosis rate in a dose- and time-dependent manner. The expression of GRP78, CHOP, caspase-12 and cleaved-caspase-3 proteins were significantly increased with LPS treatment. TG led to a marked decrease in cell viability and an increase in apoptosis rate, which aggravated the hepatocyte injury induced by LPS; whereas 4-PBA alleviated LPS-induced apoptosis. ERS mediates LPS-induced hepatocyte injuries, indicating that ERS may play a vital role in the pathogenesis of LPS-induced hepatocyte injuries.

Bushen Zhuangjin decoction inhibits TM-induced chondrocyte apoptosis mediated by endoplasmic reticulum stress.

PubMed

Lin, Pingdong; Weng, Xiaping; Liu, Fayuan; Ma, Yuhuan; Chen, Houhuang; Shao, Xiang; Zheng, Wenwei; Liu, Xianxiang; Ye, Hongzhi; Li, Xihai

2015-12-01

-9, caspase-3 and Bax were significantly decreased, whereas the mRNA and protein expression levels of Xbp1 and Bcl-2 were significantly increased compared with the TM‑stimulated chondrocytes not treated with BZD. Additionally, all our findings demonstrated that there was no significant difference between the TM‑stimulated chondrocytes treated with BZD and those treated with 4‑PBA. Taken together, our results indicate that BZD inhibits TM‑induced chondrocyte apoptosis mediated by ER stress. Thus, BZD may be a potential therapeutic agent for use in the treatment of OA.

Oxidative Stress-Responsive Apoptosis Inducing Protein (ORAIP) Plays a Critical Role in High Glucose-Induced Apoptosis in Rat Cardiac Myocytes and Murine Pancreatic β-Cells.

PubMed

Yao, Takako; Fujimura, Tsutomu; Murayama, Kimie; Okumura, Ko; Seko, Yoshinori

2017-10-18

We previously identified a novel apoptosis-inducing humoral factor in the conditioned medium of hypoxic/reoxygenated-cardiac myocytes. We named this novel post-translationally-modified secreted-form of eukaryotic translation initiation factor 5A Oxidative stress-Responsive Apoptosis-Inducing Protein (ORAIP). We confirmed that myocardial ischemia/reperfusion markedly increased plasma ORAIP levels and rat myocardial ischemia/reperfusion injury was clearly suppressed by neutralizing anti-ORAIP monoclonal antibodies (mAbs) in vivo. In this study, to investigate the mechanism of cell injury of cardiac myocytes and pancreatic β-cells involved in diabetes mellitus (DM), we analyzed plasma ORAIP levels in DM model rats and the role of ORAIP in high glucose-induced apoptosis of cardiac myocytes in vitro. We also examined whether recombinant-ORAIP induces apoptosis in pancreatic β-cells. Plasma ORAIP levels in DM rats during diabetic phase were about 18 times elevated as compared with non-diabetic phase. High glucose induced massive apoptosis in cardiac myocytes (66.2 ± 2.2%), which was 78% suppressed by neutralizing anti-ORAIP mAb in vitro. Furthermore, recombinant-ORAIP clearly induced apoptosis in pancreatic β-cells in vitro. These findings strongly suggested that ORAIP plays a pivotal role in hyperglycemia-induced myocardial injury and pancreatic β-cell injury in DM. ORAIP will be a biomarker and a critical therapeutic target for cardiac injury and progression of DM itself.

[The mechanism of docetaxel-induced apoptosis in human lung cancer cells].

PubMed

Li, Y; Shi, T; Zhao, W

2000-05-01

To study the mechanism of docetaxel-induced apoptosis. Morphological study, DNA gel electrophoresis, flow cytometry and fluorescin labeled Annexin V to detect apoptosis, RT-PCR to detect the gene related with apoptosis. Human lung cancer A549 cells treated with docetaxel induced cell cycle arrest at G2M phase, leading to apoptosis. The morphology of A549 showed nuclear chromatine condensation and fragmentation. Typical ladder pattern of DNA fragmentation was observed. Sub-G1 peak was found by flow cytometry. Transcription of Fas gene was enhanced, while no change in c-myc and bcl-2 genes. Annexin labeling results revealed the co-existence of cell apoptosis and necrosis in docetaxel-treated A549 cells. Docetaxel induces apoptosis and necrosis of human lung cancer. The induction of apoptosis may be related to expression of Fas.

Cyproterone acetate enhances TRAIL-induced androgen-independent prostate cancer cell apoptosis via up-regulation of death receptor 5.

PubMed

Chen, Linjie; Wolff, Dennis W; Xie, Yan; Lin, Ming-Fong; Tu, Yaping

2017-03-07

Virtually all prostate cancer deaths occur due to obtaining the castration-resistant phenotype after prostate cancer cells escaped from apoptosis and/or growth suppression initially induced by androgen receptor blockade. TNF-related apoptosis-inducing ligand (TRAIL) was an attractive cancer therapeutic agent due to its minimal toxicity to normal cells and remarkable apoptotic activity in tumor cells. However, most localized cancers including prostate cancer are resistant to TRAIL-induced apoptosis, thereby creating a therapeutic challenge of inducing TRAIL sensitivity in cancer cells. Herein the effects of cyproterone acetate, an antiandrogen steroid, on the TRAIL-induced apoptosis of androgen receptor-negative prostate cancer cells are reported. Cell apoptosis was assessed by both annexin V/propidium iodide labeling and poly (ADP-ribose) polymerase cleavage assays. Gene and protein expression changes were determined by quantitative real-time PCR and western blot assays. The effect of cyproterone acetate on gene promoter activity was determined by luciferase reporter assay. Cyproterone acetate but not AR antagonist bicalutamide dramatically increased the susceptibility of androgen receptor-negative human prostate cancer PC-3 and DU145 cells to TRAIL-induced apoptosis but no effects on immortalized human prostate stromal PS30 cells and human embryonic kidney HEK293 cells. Further investigation of the TRAIL-induced apoptosis pathway revealed that cyproterone acetate exerted its effect by selectively increasing death receptor 5 (DR5) mRNA and protein expression. Cyproterone acetate treatment also increased DR5 gene promoter activity, which could be abolished by mutation of a consensus binding domain of transcription factor CCAAT-enhancer-binding protein homologous protein (CHOP) in the DR5 gene promoter. Cyproterone acetate increases CHOP expression in a concentration and time-dependent manner and endoplasmic reticulum stress reducer 4-phenylbutyrate could block

Inhibition of cyclooxygenase-2-dependent survivin mediates decursin-induced apoptosis in human KBM-5 myeloid leukemia cells.

PubMed

Ahn, Quein; Jeong, Soo-Jin; Lee, Hyo-Jung; Kwon, Hee-Young; Han, Ihn; Kim, Hyun Seok; Lee, Hyo-Jeong; Lee, Eun-Ok; Ahn, Kwang Seok; Jung, Min-Hyung; Zhu, Shudong; Chen, Chang-Yan; Kim, Sung-Hoon

2010-12-08

We demonstrate that decursin induces apoptosis via regulation of cyclooxygenase-2 (COX-2) and survivin in leukemic KBM-5 cells. By activating an apoptotic machinery, decursin is cytotoxic to KBM-5 cells. In this apoptotic process, decursin can activate caspase family members and triggers PARP cleavage. At the same time, the expression of COX-2 and survivin in the cells is downregulated. Furthermore, decursin is in synergy with COX-2 inhibitor, celecoxib or NS398 for the induction of apoptosis. Overall, these results suggest that decursin, via inhibiting COX-2 and survivin, sensitizes human leukemia cells to apoptosis and is a potential chemotherapeutic agent to treat this disease. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Neuroprotective effects of ganoderma lucidum polysaccharides against oxidative stress-induced neuronal apoptosis.

PubMed

Sun, Xin-Zhi; Liao, Ying; Li, Wei; Guo, Li-Mei

2017-06-01

Ganoderma lucidum polysaccharides have protective effects against apoptosis in neurons exposed to ischemia/reperfusion injury, but the mechanisms are unclear. The goal of this study was to investigate the underlying mechanisms of the effects of ganoderma lucidum polysaccharides against oxidative stress-induced neuronal apoptosis. Hydrogen peroxide (H 2 O 2 ) was used to induce apoptosis in cultured cerebellar granule cells. In these cells, ganoderma lucidum polysaccharides remarkably suppressed H 2 O 2 -induced apoptosis, decreased expression of caspase-3, Bax and Bim and increased that of Bcl-2. These findings suggested that ganoderma lucidum polysaccharides regulate expression of apoptosis-associated proteins, inhibit oxidative stress-induced neuronal apoptosis and, therefore, have significant neuroprotective effects.

Raman spectrum reveals the cell cycle arrest of Triptolide-induced leukemic T-lymphocytes apoptosis

NASA Astrophysics Data System (ADS)

Zhang, Daosen; Feng, Yanyan; Zhang, Qinnan; Su, Xin; Lu, Xiaoxu; Liu, Shengde; Zhong, Liyun

2015-04-01

Triptolide (TPL), a traditional Chinese medicine extract, possesses anti-inflammatory and anti-tumor properties. Though some research results have implicated that Triptolide (TPL) can be utilized in the treatment of leukemia, it remains controversial about the mechanism of TPL-induced leukemic T-lymphocytes apoptosis. In this study, combining Raman spectroscopic data, principal component analysis (PCA) and atomic force microscopy (AFM) imaging, both the biochemical changes and morphological changes during TPL-induced cell apoptosis were presented. In contrast, the corresponding data during Daunorubicin (DNR)-induced cell apoptosis was also exhibited. The obtained results showed that Raman spectral changes during TPL-induced cell apoptosis were greatly different from DNR-induced cell apoptosis in the early stage of apoptosis but revealed the high similarity in the late stage of apoptosis. Moreover, above Raman spectral changes were respectively consistent with the morphological changes of different stages during TPL-induced apoptosis or DNR-induced apoptosis, including membrane shrinkage and blebbing, chromatin condensation and the formation of apoptotic bodies. Importantly, it was found that Raman spectral changes with TPL-induced apoptosis or DNR-induced apoptosis were respectively related with the cell cycle G1 phase arrest or G1 and S phase arrest.

Interplay between autophagy and apoptosis in lead(II)-induced cytotoxicity of primary rat proximal tubular cells.

PubMed

Chu, Bing-Xin; Fan, Rui-Feng; Lin, Shu-Qian; Yang, Du-Bao; Wang, Zhen-Yong; Wang, Lin

2018-05-01

Autophagy and apoptosis are two different biological processes that determine cell fates. We previously reported that autophagy inhibition and apoptosis induction are involved in lead(II)-induced cytotoxicity in primary rat proximal tubular (rPT) cells, but the interplay between them remains to be elucidated. Firstly, data showed that lead(II)-induced elevation of LC3-II protein levels can be significantly modulated by 3-methyladenine or rapamycin; moreover, protein levels of Autophagy-related protein 5 (Atg5) and Beclin-1 were markedly up-regulated by lead(II) treatment, demonstrating that lead(II) could promote the autophagosomes formation in rPT cells. Next, we applied three pharmacological agents and genetic method targeting the early stage of autophagy to validate that enhancement of autophagosomes formation can inhibit lead(II)-induced apoptotic cell death in rPT cells. Simultaneously, lead(II) inhibited the autophagic degradation of rPT cells, while the addition of autophagic degradation inhibitor bafilomycin A1 aggravated lead(II)-induced apoptotic death in rPT cells. Collectively, this study provided us a good model to know about the dynamic process of lead(II)-induced autophagy in rPT cells, and the interplay between autophagy and apoptosis highlights a new sight into the mechanism of lead(II)-induced nephrotoxicity. Copyright © 2018. Published by Elsevier Inc.

Zoledronate induces apoptosis in cells from fibro-cellular membrane of unicameral bone cyst (UBC).

PubMed

Yu, John; Chang, Seong-Sil; Suratwala, Sanjeev; Chung, Woo-Sik; Abdelmessieh, Peter; Lee, Hahn-Jun; Yang, Jay; Lee, Francis Young-In

2005-09-01

Unicameral bone cyst (UBC) is a benign cystic lesion in children which is prone to fracture. Various treatments are available, but recurrence after different types of percutaneous injection therapy can cause bone destruction and pathologic fracture. The potential therapeutic effects of anti-resorptive agents, such as bisphosphonates, have not been investigated for UBC. The objective of this study was to characterize the cells from the fibro-cellular membrane of unicameral bone cyst (UBC cells) and to determine whether zoledronate, a nitrogen-containing bisphosphonate, could induce apoptosis in UBC cells. Flow cytometry and immunoblotting were performed in order to determine whether zoledronate induced apoptosis. Cells derived from normal human trabecular bones were used as controls against UBC cells to compare the effect of zoledronate in inducing apoptosis. Immunohisto/cytochemistry (IHC/ICC) and mini-array analyses were performed on tissues and cultured cells. Isolated peripheral blood mononuclear cells were incubated with conditioned media from the UBC cells to determine whether they are capable of inducing osteoclastogenesis. UBC membrane is composed of cells staining positively with CD68, SDF-1, STRO-1 and RANKL, but in vitro cells showed no staining with antibodies to CD68 and STRO-1, suggesting that there was a clonal selection of stromal cells during cell culture. UBC cells also express RUNX2 (runt-related transcription factor-2, core binding factor-1), a key transcription factor for osteoblastic differentiation. In addition, media collected from UBC cells induced a generation of multi-nucleated osteoclast-like cells of peripheral blood mononuclear cells. Zoledronate induced apoptosis of UBC cells in a dose-dependent manner. Apoptosis was evidenced by induction of the active cleaved form of caspase-3. The baseline apoptotic fractions were similar in UBC cells and trabecular bone cells. However, in the overall apoptotic fractions in this study, trabecular

The neem limonoids azadirachtin and nimbolide inhibit cell proliferation and induce apoptosis in an animal model of oral oncogenesis.

PubMed

Harish Kumar, G; Vidya Priyadarsini, R; Vinothini, G; Vidjaya Letchoumy, P; Nagini, S

2010-08-01

Limonoids from the neem tree (Azadirachta indica) have attracted considerable research attention for their cytotoxicity against human cancer cell lines. However, the antiproliferative and apoptosis inducing effects of neem limonoids have not been tested in animal tumour models. The present study was therefore designed to evaluate the relative chemopreventive potential of the neem limonoids azadirachtin and nimbolide in the hamster buccal pouch (HBP) carcinogenesis model by analyzing the expression of proliferating cell nuclear antigen (PCNA), p21(waf1), cyclin D1, glutathione S-transferase pi (GST-P), NF-kappaB, inhibitor of kappaB (IkappaB), p53, Fas, Bcl-2, Bax, Bid, Apaf-1, cytochrome C, survivin, caspases-3, -6, -8 and -9, and poly(ADP-ribose) polymerase (PARP) by RT-PCR, immunohistochemical, and Western blot analyses. The results provide compelling evidence that azadirachtin and nimbolide mediate their antiproliferative effects by downregulating proteins involved in cell cycle progression and transduce apoptosis by both the intrinsic and extrinsic pathways. On a comparative basis, nimbolide was found to be a more potent antiproliferative and apoptosis inducing agent and offers promise as a candidate agent in multitargeted prevention and treatment of cancer.

Bupivacaine induces apoptosis via ROS in the Schwann cell line.

PubMed

Park, C J; Park, S A; Yoon, T G; Lee, S J; Yum, K W; Kim, H J

2005-09-01

Local anesthetics have been generally accepted as being safe. However, recent clinical trials and basic studies have provided strong evidence for the neurotoxicity of local anesthetics, especially through apoptosis. We hypothesized that local anesthetics cause neural complications through Schwann cell apoptosis. Among local anesthetics tested on the Schwann cell line, RT4-D6P2T, bupivacaine significantly induced cell death, measured by the methyl tetrazolium (MTT) assay, in a dose- (LD50 = 476 microM) and time-dependent manner. The bupivacaine-induced generation of reactive oxygen species (ROS), which was initiated within 5 hrs and preceded the activation of caspase-3 and poly ADP-ribose polymerase (PARP) degradation, was suggested to trigger apoptosis, exhibited by Hoechst 33258 nuclear staining and DNA fragmentation. Furthermore, concomitant block of ROS by anti-oxidants significantly inhibited bupivacaine-induced apoptosis. Among the local anesthetics for peripheral neural blocks, bupivacaine induced apoptosis in the Schwann cell line, which may be associated with ROS production.

Curcumin inhibits activation of Vgamma9Vdelta2 T cells by phosphoantigens and induces apoptosis involving apoptosis-inducing factor and large scale DNA fragmentation.

PubMed

Cipriani, B; Borsellino, G; Knowles, H; Tramonti, D; Cavaliere, F; Bernardi, G; Battistini, L; Brosnan, C F

2001-09-15

Curcumin, in addition to its role as a spice, has been used for centuries to treat inflammatory disorders. Although the mechanism of action remains unclear, it has been shown to inhibit the activation of NF-kappaB and AP-1, transcription factors required for induction of many proinflammatory mediators. Due to its low toxicity it is currently under consideration as a broad anti-inflammatory, anti-tumor cell agent. In this study we investigated whether curcumin inhibited the response of gammadelta T cells to protease-resistant phosphorylated derivatives found in the cell wall of many pathogens. The results showed that curcumin levels > or =30 microM profoundly inhibited isopentenyl pyrophosphate-induced release of the chemokines macrophage inflammatory protein-1alpha and -1beta and RANTES. Curcumin also blocked isopentenyl pyrophosphate-induced activation of NF-kappaB and AP-1. Commencing around 16 h, treatment with curcumin lead to the induction of cell death that could not be reversed by APC, IL-15, or IL-2. This cytotoxicity was associated with increased annexin V reactivity, nuclear expression of active caspase-3, cleavage of poly(ADP-ribose) polymerase, translocation of apoptosis-inducing factor to the nucleus, and morphological evidence of nuclear disintegration. However, curcumin led to only large scale DNA chromatolysis, as determined by a combination of TUNEL staining and pulse-field and agarose gel electrophoresis, suggesting a predominantly apoptosis-inducing factor-mediated cell death process. We conclude that gammadelta T cells activated by these ubiquitous Ags are highly sensitive to curcumin, and that this effect may contribute to the anti-inflammatory properties of this compound.

Zinc finger protein 598 inhibits cell survival by promoting UV-induced apoptosis.

PubMed

Yang, Qiaohong; Gupta, Romi

2018-01-19

UV is one of the major causes of DNA damage induced apoptosis. However, cancer cells adopt alternative mechanisms to evade UV-induced apoptosis. To identify factors that protect cancer cells from UV-induced apoptosis, we performed a genome wide short-hairpin RNA (shRNA) screen, which identified Zinc finger protein 598 (ZNF598) as a key regulator of UV-induced apoptosis. Here, we show that UV irradiation transcriptionally upregulates ZNF598 expression. Additionally, ZNF598 knockdown in cancer cells inhibited UV-induced apoptosis. In our study, we observe that ELK1 mRNA level as well as phosphorylated ELK1 levels was up regulated upon UV irradiation, which was necessary for UV irradiation induced upregulation of ZNF598. Cells expressing ELK1 shRNA were also resistant to UV-induced apoptosis, and phenocopy ZNF598 knockdown. Upon further investigation, we found that ZNF598 knockdown inhibits UV-induced apoptotic gene expression, which matches with decrease in percentage of annexin V positive cell. Similarly, ectopic expression of ZNF598 promoted apoptotic gene expression and also increased annexin V positive cells. Collectively, these results demonstrate that ZNF598 is a UV irradiation regulated gene and its loss results in resistance to UV-induced apoptosis.

Antiproliferative and Apoptotic Effect of Curcumin and TRAIL (TNF Related Apoptosis inducing Ligand) in Chronic Myeloid Leukaemic Cells

PubMed Central

Iqbal, Bushra; Sahabjada; Singh, Shraddha; Arshad, Mohd.; Mahdi, Abbas Ali; Tiwari, Sunita

2016-01-01

Introduction Curcumin, traditionally utilized as a flavouring zest as a part of Indian cooking, has been accounted to decrease the proliferation potential of most cancer cells. Apoptosis is a mechanism by which most anticancer therapies including chemotherapy, radiation and antihormonal therapy kill tumour/cancer cells. Novel agents that may sensitize drug-resistant tumour cells for induction of apoptosis by customary treatments could lead to the regression and improved prognosis of the refractory disease. Indeed, chemotherapeutic agents have been shown to sensitize cancer cells to killing by death ligands such as tumour necrosis factor-α. Aim To investigate cytotoxicity and apoptotic effect of curcumin in chronic myeloid leukaemic cell line KCL-22. Materials and Methods In present study, different doses of curcumin (10,25,50,75,100μM) and tumour necrosis factor–related apoptosis-inducing ligand (TRAIL) (25,50 μM) alone and combine regimen were exposed to myeloid leukaemic cell KCL-22. The cell viability was monitored by MTT assay, apoptotic activity by binding of Annexin V-FITC using fluorescence microscopy and cell cycle check points by flow cytometry. Results Cytotoxic assay revealed that curcumin and TRAIL induced both dose and time-dependent decrease in cell viability. Significant cell cytotoxicity was seen in combine regimen of both curcumin and TRAIL at 48 h of exposure. Cells treated with curcumin and TRAIL was arrested at the S phase, as revealed by flow cytometric analysis. Subtoxic concentrations of the curcumin-TRAIL combination induced strong apoptotic response in KCL-22 cells as demonstrated by the binding of Annexin V-FITC. Conclusion Our study conclude that curcumin inhibits the cancer cell growth by inducing apoptosis and enhance the therapeutic potential of TRAIL which recommends that both curcumin alone or in combination with TRAIL might be useful for leukaemic prevention and better therapeutic responses. PMID:27190933

Minocycline attenuates colistin-induced neurotoxicity via suppression of apoptosis, mitochondrial dysfunction and oxidative stress.

PubMed

Dai, Chongshan; Ciccotosto, Giuseppe D; Cappai, Roberto; Wang, Yang; Tang, Shusheng; Xiao, Xilong; Velkov, Tony

2017-06-01

Neurotoxicity is an adverse effect patients experience during colistin therapy. The development of effective neuroprotective agents that can be co-administered during polymyxin therapy remains a priority area in antimicrobial chemotherapy. The present study investigates the neuroprotective effect of the synergistic tetracycline antibiotic minocycline against colistin-induced neurotoxicity. The impact of minocycline pretreatment on colistin-induced apoptosis, caspase activation, oxidative stress and mitochondrial dysfunction were investigated using cultured mouse neuroblastoma-2a (N2a) and primary cortical neuronal cells. Colistin-induced neurotoxicity in mouse N2a and primary cortical cells gives rise to the generation of reactive oxygen species (ROS) and subsequent cell death via apoptosis. Pretreatment of the neuronal cells with minocycline at 5, 10 and 20 μM for 2 h prior to colistin (200 μM) exposure (24 h), had an neuroprotective effect by significantly decreasing intracellular ROS production and by upregulating the activities of the anti-ROS enzymes superoxide dismutase and catalase. Minocycline pretreatment also protected the cells from colistin-induced mitochondrial dysfunction, caspase activation and subsequent apoptosis. Immunohistochemical imaging studies revealed colistin accumulates within the dendrite projections and cell body of primary cortical neuronal cells. To our knowledge, this is first study demonstrating the protective effect of minocycline on colistin-induced neurotoxicity by scavenging of ROS and suppression of apoptosis. Our study highlights that co-administration of minocycline kills two birds with one stone: in addition to its synergistic antimicrobial activity, minocycline could potentially ameliorate unwanted neurotoxicity in patients undergoing polymyxin therapy. © The Author 2017. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions

Effects of tumor necrosis factor-related apoptosis-inducing ligand alone and in combination with chemotherapeutic agents on patients' colon tumors grown in SCID mice.

PubMed

Naka, Takuji; Sugamura, Kenji; Hylander, Bonnie L; Widmer, Michael B; Rustum, Youcef M; Repasky, Elizabeth A

2002-10-15

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has been reported to induce apoptosis in a variety of malignant cell lines, but it shows little or no toxicity in most normal cells. We examined the response of three human colon tumors to TRAIL alone and in combination with chemotherapy, using SCID mice engrafted with intact patient surgical specimens. These tumors, taken from fresh surgical specimens, contained the heterogeneous tumor cell population characteristic of patient tumors and showed differential sensitivity to TRAIL alone. We also investigated the effect of TRAIL in combination with chemotherapy, using one tumor that showed moderate sensitivity to TRAIL alone. Combining TRAIL with either 5-fluorouracil (5-FU) or CPT-11 (irinotecan hydrochloride) produced a greatly enhanced antitumor effect over that of either agent alone, with 50% of the animals achieving complete tumor regression with a combination of TRAIL and CPT-11. By histological analysis, tumors treated with TRAIL plus either 5-FU or CPT-11 were seen to consist mainly of connective tissue and fibrotic areas with only a few scattered tumor cells encapsulated in the connective tissue. Several markers were assessed to investigate the basis for the observed therapeutic effect, and significant induction of apoptosis was observed in tumors treated with curative combinations. Cytoplasmic and cell surface expression of the TRAIL receptors DR4 and DR5 was observed in this patient's tumor by immunohistochemistry. Tumors treated with CPT-11 showed increased membrane expression of DR5, suggesting that CPT-11 may increase sensitivity to TRAIL by up-regulation of DR5. These results obtained in a relevant preclinical model support the idea that the use of TRAIL in combination with either 5-FU or CPT-11 may be an effective strategy in controlling human colon cancer.

Deoxyelephantopin from Elephantopus scaber L. induces cell-cycle arrest and apoptosis in the human nasopharyngeal cancer CNE cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Su, Miaoxian; Chung, Hau Yin, E-mail: anthonychung@cuhk.edu.hk; Food and Nutritional Sciences Programme, School of Life Sciences, The Chinese University of Hong Kong, Hong Kong SAR

2011-07-29

Highlights: {yields} Deoxyelephantopin (ESD) inhibited cell proliferation in the human nasopharyngeal cancer CNE cells. {yields} ESD induced cell cycle arrest in S and G2/M phases via modulation of cell cycle regulatory proteins. {yields} ESD triggered apoptosis by dysfunction of mitochondria and induction of both intrinsic and extrinsic apoptotic signaling pathways. {yields} ESD also triggered Akt, ERK, and JNK signaling pathways. -- Abstract: Deoxyelephantopin (ESD), a naturally occurring sesquiterpene lactone present in the Chinese medicinal herb, Elephantopus scaber L. exerted anticancer effects on various cultured cancer cells. However, the cellular mechanisms by which it controls the development of the cancer cellsmore » are unavailable, particularly the human nasopharyngeal cancer CNE cells. In this study, we found that ESD inhibited the CNE cell proliferation. Cell cycle arrest in S and G2/M phases was also found. Western blotting analysis showed that modulation of cell cycle regulatory proteins was responsible for the ESD-induced cell cycle arrest. Besides, ESD also triggered apoptosis in CNE cells. Dysfunction in mitochondria was found to be associated with the ESD-induced apoptosis as evidenced by the loss of mitochondrial membrane potential ({Delta}{Psi}m), the translocation of cytochrome c, and the regulation of Bcl-2 family proteins. Despite the Western blotting analysis showed that both intrinsic and extrinsic apoptotic pathways (cleavage of caspases-3, -7, -8, -9, and -10) were triggered in the ESD-induced apoptosis, additional analysis also showed that the induction of apoptosis could be achieved by the caspase-independent manner. Besides, Akt, ERK and JNK pathways were found to involve in ESD-induced cell death. Overall, our findings provided the first evidence that ESD induced cell cycle arrest, and apoptosis in CNE cells. ESD could be a potential chemotherapeutic agent in the treatment of nasopharyngeal cancer (NPC).« less

Apoptosis-induced lymphopenia in sepsis and other severe injuries.

PubMed

Girardot, Thibaut; Rimmelé, Thomas; Venet, Fabienne; Monneret, Guillaume

2017-02-01

Sepsis and other acute injuries such as severe trauma, extensive burns, or major surgeries, are usually followed by a period of marked immunosuppression. In particular, while lymphocytes play a pivotal role in immune response, their functions and numbers are profoundly altered after severe injuries. Apoptosis plays a central role in this process by affecting immune response at various levels. Indeed, apoptosis-induced lymphopenia duration and depth have been associated with higher risk of infection and mortality in various clinical settings. Therapies modulating apoptosis represent an interesting approach to restore immune competence after acute injury, although their use in clinical practice still presents several limitations. After briefly describing the apoptosis process in physiology and during severe injuries, we will explore the immunological consequences of injury-induced lymphocyte apoptosis, and describe associations with clinically relevant outcomes in patients. Therapeutic perspectives targeting apoptosis will also be discussed.

Protective effects of total saponins from stem and leaf of Panax ginseng against cyclophosphamide-induced genotoxicity and apoptosis in mouse bone marrow cells and peripheral lymphocyte cells.

PubMed

Zhang, Qiu Hua; Wu, Chun Fu; Duan, Lian; Yang, Jing Yu

2008-01-01

Cyclophosphamide (CP), commonly used anti-cancer, induces oxidative stress and is cytotoxic to normal cells. It is very important to choice the protective agent combined CP to reduce the side effects in cancer treatment. Ginsenosides are biological active constituents of Panax ginseng C.A. Meyer that acts as the tonic agent for the cancer patients to reduce the side effects in the clinic application. Because CP is a pro-oxidant agent and induces oxidative stress by the generation of free radicals to decrease the activities of anti-oxidant enzymes, the protective effects of the total saponins from stem and leaf of P. ginseng C.A. Meyer (TSPG) act as an anti-oxidant agent against the decreased anti-oxidant enzymes, the genotoxicity and apoptosis induced by CP was carried out. The alkaline single cell gel electrophoresis was employed to detect DNA damage; flow cytometry assay and AO/EB staining assay were employed to measure cell apoptosis; the enzymatic anti-oxidants (T-SOD, CAT and GPx) and non-enzymatic anti-oxidant (GSH) were measured by the various colorimetric methods. CP induced the significant DNA damage in mouse peripheral lymphocytes in time- and dose-dependent manners, inhibited the activities of T-SOD, GPx and CAT, and decreased the contents of GSH in mouse blood, triggered bone marrow cell apoptosis at 6 and 12h. TSPG significantly reduced CP-induced DNA damages in bone marrow cells and peripheral lymphocyte cells, antagonized CP-induced reduction of T-SOD, GPx, CAT activities and the GSH contents, decreased the bone marrow cell apoptosis induced by CP. TSPG, significantly reduced the genotoxicity of CP in bone marrow cells and peripheral lymphocyte cells, and decreased the apoptotic cell number induced by CP in bone marrow cells. The effects of TSPG on T-SOD, GPx, CAT activities and GSH contents might partially contribute to its protective effects on CP-induced cell toxicities.

Novel targets for sensitizing breast cancer cells to TRAIL-induced apoptosis with siRNA delivery.

PubMed

Thapa, Bindu; Bahadur Kc, Remant; Uludağ, Hasan

2018-02-01

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) induces apoptosis in variety of cancer cells without affecting most normal cells, which makes it a promising agent for cancer therapy. However, TRAIL therapy is clinically not effective due to resistance induction. To identify novel regulators of TRAIL that can aid in therapy, protein targets whose silencing sensitized breast cancer cells against TRAIL were screened with an siRNA library against 446 human apoptosis-related proteins in MDA-231 cells. Using a cationic lipopolymer (PEI-αLA) for delivery of library members, 16 siRNAs were identified that sensitized the TRAIL-induced death in MDA-231 cells. The siRNAs targeting BCL2L12 and SOD1 were further evaluated based on the novelty and their ability to sensitize TRAIL induced cell death. Silencing both targets sensitized TRAIL-mediated cell death in MDA-231 cells as well as TRAIL resistant breast cancer cells, MCF-7. Combination of TRAIL and siRNA silencing BCL2L12 had no effect in normal human umbilical vein cells and human bone marrow stromal cell. The silencing of BCL2L12 and SOD1 enhanced TRAIL-mediated apoptosis in MDA-231 cells via synergistically activating capsase-3 activity. Hence, here we report siRNAs targeting BCL2L12 and SOD1 as a novel regulator of TRAIL-induced cell death in breast cancer cells, providing a new approach for enhancing TRAIL therapy for breast cancer. The combination of siRNA targeting BCL2L12 and TRAIL can be a highly effective synergistic pair in breast cancer cells with minimal effect on the non-transformed cells. © 2017 UICC.

Lipopolysaccharide Stimulates Butyric Acid-Induced Apoptosis in Human Peripheral Blood Mononuclear Cells

PubMed Central

Kurita-Ochiai, Tomoko; Fukushima, Kazuo; Ochiai, Kuniyasu

1999-01-01

We previously reported that butyric acid, an extracellular metabolite from periodontopathic bacteria, induced apoptosis in murine thymocytes, splenic T cells, and human Jurkat T cells. In this study, we examined the ability of butyric acid to induce apoptosis in peripheral blood mononuclear cells (PBMC) and the effect of bacterial lipopolysaccharide (LPS) on this apoptosis. Butyric acid significantly inhibited the anti-CD3 monoclonal antibody- and concanavalin A-induced proliferative responses in a dose-dependent fashion. This inhibition of PBMC growth by butyric acid depended on apoptosis in vitro. It was characterized by internucleosomal DNA digestion and revealed by gel electrophoresis followed by a colorimetric DNA fragmentation assay to occur in a concentration-dependent fashion. Butyric acid-induced PBMC apoptosis was accompanied by caspase-3 protease activity but not by caspase-1 protease activity. LPS potentiated butyric acid-induced PBMC apoptosis in a dose-dependent manner. Flow-cytometric analysis revealed that LPS increased the proportion of sub-G1 cells and the number of late-stage apoptotic cells induced by butyric acid. Annexin V binding experiments with fractionated subpopulations of PBMC in flow cytometory revealed that LPS accelerated the butyric acid-induced CD3+-T-cell apoptosis followed by similar levels of both CD4+- and CD8+-T-cell apoptosis. The addition of LPS to PBMC cultures did not cause DNA fragmentation, suggesting that LPS was unable to induce PBMC apoptosis directly. These data suggest that LPS, in combination with butyric acid, potentiates CD3+ PBMC T-cell apoptosis and plays a role in the apoptotic depletion of CD4+ and CD8+ cells. PMID:9864191

Involvement of Bim in Photofrin-mediated photodynamically induced apoptosis.

PubMed

Wang, Xianwang; He, Xiaobing; Hu, Shujuan; Sun, Anbang; Lu, Chengbiao

2015-01-01

Photodynamic therapy (PDT) is a promising noninvasive technique, which has been successfully applied to the treatment of human cancers. Studies have shown that the Bcl-2 family proteins play important roles in PDT-induced apoptosis. However, whether Bcl-2-interacting mediator of cell death (Bim) is involved in photodynamic treatment remains unknown. In this study, we attempt to determine the effect of Bim on Photofrin photodynamic treatment (PPT)-induced apoptosis in human lung adenocarcinoma ASTC-a-1 cells. The translocation of Bim/Bax of the cells were monitored by laser confocal scanning microscope. The levels of Bim protein and activated caspase-3 in cells were detected by western blot assay. Caspase-3 activities were measured by Caspase-3 Fluorogenic Substrate (Ac-DEVD-AFC) analysis. The induction of apoptosis was detected by Hoechst 33258 and PI staining as well as flow cytometry analysis. The effect of Bim on PPT-induced apoptosis was determined by RNAi. BimL translocated to mitochondria in response to PPT, similar to the downstream pro-apoptotic protein Bax activation. PPT increased the level of Bim and activated caspase-3 in cells and that knockdown of Bim by RNAi significantly protected against caspase-3 activity. PPT-induced apoptosis were suppressed in cells transfected with shRNA-Bim. We demonstrated the involvement of Bim in PPT-induced apoptosis in human ASTC-a-1 lung adenocarcinoma cells and suggested that enhancing Bim activity might be a potential strategy for treating human cancers. © 2015 S. Karger AG, Basel.

Lysophosphatidic acid rescues bone mesenchymal stem cells from hydrogen peroxide-induced apoptosis.

PubMed

Wang, Xian-Yun; Fan, Xue-Song; Cai, Lin; Liu, Si; Cong, Xiang-Feng; Chen, Xi

2015-03-01

The increase of reactive oxygen species in infracted heart significantly reduces the survival of donor mesenchymal stem cells, thereby attenuating the therapeutic efficacy for myocardial infarction. In our previous study, we demonstrated that lysophosphatidic acid (LPA) protects bone marrow-derived mesenchymal stem cells (BMSCs) against hypoxia and serum deprivation-induced apoptosis. However, whether LPA protects BMSCs from H2O2-induced apoptosis was not examined. In this study, we report that H2O2 induces rat BMSC apoptosis whereas LPA pre-treatment effectively protects BMSCs from H2O2-induced apoptosis. LPA protection of BMSC from the induced apoptosis is mediated mostly through LPA3 receptor. Furthermore, we found that membrane G protein Gi2 and Gi3 are involved in LPA-elicited anti-apoptotic effects through activation of ERK1/2- and PI3 K-pathways. Additionally, H2O2 increases levels of type II of light chain 3B (LC3B II), an autophagy marker, and H2O2-induced autophagy thus protected BMSCs from apoptosis. LPA further increases the expression of LC3B II in the presence of H2O2. In contrast, autophagy flux inhibitor bafilomycin A1 has no effect on LPA's protection of BMSC from H2O2-induced apoptosis. Taken together, our data suggest that LPA rescues H2O2-induced apoptosis mainly by interacting with Gi-coupled LPA3, resulting activation of the ERK1/2- and PI3 K/AKT-pathways and inhibition caspase-3 cleavage, and LPA protection of BMSCs against the apoptosis is independent of it induced autophagy.

Sinularin Induces Apoptosis through Mitochondria Dysfunction and Inactivation of the pI3K/Akt/mTOR Pathway in Gastric Carcinoma Cells.

PubMed

Wu, Yu-Jen; Wong, Bing-Sang; Yea, Shu-Hao; Lu, Chi-I; Weng, Shun-Hsiang

2016-07-27

Sinularin is an active compound isolated from the cultured soft coral Sinularia flexibilis. In this study, we investigated the effects of sinularin on two human gastric cancer cell lines, AGS and NCI-N87. Our results demonstrated that sinularin suppressed the proliferation of gastric cancer cells in a dose-dependent manner and induced apoptosis. In addition, the loss of mitochondrial membrane potential, the release of cytochrome C, the activation of Bax, Bad and caspase-3/9, and the suppression of p-Bad, Bcl-xL and Bcl-2 were observed in the cells treated with sinularin. This finding suggests that sinularin-induced apoptosis is associated with mitochondria-mediated apoptosis and occurs through caspase-dependent pathways. Furthermore, sinularin inhibited the phosphoinositol 3-kinase/Akt/mechanistic target of the rapamycin signaling pathway. Taken together, our results show that sinularin-induced apoptosis is mediated by activation of the caspase cascade and mitochondrial dysfunction. Our findings suggest that sinularin merits further evaluation as a chemotherapeutic agent for human gastric cancer.

Berberine-induced apoptosis in human prostate cancer cells is initiated by reactive oxygen species generation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meeran, Syed M.; Katiyar, Suchitra; Katiyar, Santosh K.

2008-05-15

Phytochemicals show promise as potential chemopreventive or chemotherapeutic agents against various cancers. Here we report the chemotherapeutic effects of berberine, a phytochemical, on human prostate cancer cells. The treatment of human prostate cancer cells (PC-3) with berberine induced dose-dependent apoptosis but this effect of berberine was not seen in non-neoplastic human prostate epithelial cells (PWR-1E). Berberine-induced apoptosis was associated with the disruption of the mitochondrial membrane potential, release of apoptogenic molecules (cytochrome c and Smac/DIABLO) from mitochondria and cleavage of caspase-9,-3 and PARP proteins. This effect of berberine on prostate cancer cells was initiated by the generation of reactive oxygenmore » species (ROS) irrespective of their androgen responsiveness, and the generation of ROS was through the increased induction of xanthine oxidase. Treatment of cells with allopurinol, an inhibitor of xanthine oxidase, inhibited berberine-induced oxidative stress in cancer cells. Berberine-induced apoptosis was blocked in the presence of antioxidant, N-acetylcysteine, through the prevention of disruption of mitochondrial membrane potential and subsequently release of cytochrome c and Smac/DIABLO. In conclusion, the present study reveals that the berberine-mediated cell death of human prostate cancer cells is regulated by reactive oxygen species, and therefore suggests that berberine may be considered for further studies as a promising therapeutic candidate for prostate cancer.« less

Nonylphenol diethoxylate inhibits apoptosis induced in PC12 cells.

PubMed

Liu, Chuang; Sun, Yongkun; Song, Yutong; Saito, Takeshi; Kurasaki, Masaaki

2016-11-01

Nonylphenol and short-chain nonylphenol ethoxylates such as NP 2 EO are present in aquatic environment as wastewater contaminants, and their toxic effects on aquatic species have been reported. Apoptosis has been shown to be induced by serum deprivation or copper treatment. To understand the toxicity of nonylphenol diethoxylate, we investigated the effects of NP 2 EO on apoptosis induced by serum deprivation and copper by using PC12 cell system. Nonylphenol diethoxylate itself showed no toxicity and recovered cell viability from apoptosis. In addition, nonylphenol diethoxylate decreased DNA fragmentation caused by apoptosis in PC12 cells. This phenomenon was confirmed after treating apoptotic PC12 cells with nonylphenol diethoxylate, whereas the cytochrome c release into the cytosol decreased as compared to that in apoptotic cells not treated with nonylphenol diethoxylates. Furthermore, Bax contents in apoptotic cells were reduced after exposure to nonylphenol diethoxylate. Thus, nonylphenol diethoxylate has the opposite effect on apoptosis in PC12 cells compared to nonylphenol, which enhances apoptosis induced by serum deprivation. The difference in structure of the two compounds is hypothesized to be responsible for this phenomenon. These results indicated that nonylphenol diethoxylate has capability to affect cell differentiation and development and has potentially harmful effect on organisms because of its unexpected impact on apoptosis. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1389-1398, 2016. © 2015 Wiley Periodicals, Inc.

Ameliorative effects of nano-elemental selenium against hexavalent chromium-induced apoptosis in broiler liver.

PubMed

Xueting, Liu; Rehman, Mujeeb Ur; Mehmood, Khalid; Huang, Shucheng; Tian, Xinxin; Wu, Xiaoxing; Zhou, Donghai

2018-06-01

The current study examined the ameliorative effects of nano-elemental selenium (Nano-Se) against chromium-VI (K 2 Cr 2 O 7 )-induced apoptosis in chickens. The expression of apoptosis-related genes was evaluated by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blot. A total of 60, one-day-old broiler chickens allotted to six equal groups, i.e., control group (standard diet), Cr(VI)-exposed group (K 2 Cr 2 O 7 via drinking water), Nano-Se group (Nano-Se at 0.5 mg/kg via diet), protection group (K 2 Cr 2 O 7  + Nano-Se), cure group (K 2 Cr 2 O 7 for initial 2 weeks and then Nano-Se), and prevention group (opposite to the cure group) and were detected by the activities of pro-apoptosis (Bax, Caspase-3) and anti-apoptosis (Bcl-2) genes expression at day 35 of the experiment. Intense apoptosis was observed in liver tissues of chickens exposed to K 2 Cr 2 O 7 . The Nano-Se supplementation caused a significant decrease (P < 0.01) in the mRNA expression levels of Bax and Caspase-3 genes, while significantly elevated (P < 0.05) mRNA expression level of Bcl-2 gene was observed in Nano-Se experimental groups as compare to control and Cr(VI)-exposed group. The results quantified by the RT-qPCR were further confirmed by the western blot analysis. Altogether, these results suggest anti-apoptotic effects of Nano-Se in the chicken liver, which is interesting for further study. The present findings suggested that Nano-Se has protective effects against K 2 Cr 2 O 7 -induced apoptosis in broilers liver and can serve a key role as a protective agent against apoptosis.

Fermentation product of soybean, black bean, and green bean mixture induces apoptosis in a wide variety of cancer cells.

PubMed

Chia, Jean-San; Du, Jia-Ling; Wu, Ming-Shiou; Hsu, Wei-Bin; Chiang, Chun-Pin; Sun, Andy; Lu, John Jenn-Yenn; Wang, Won-Bo

2013-05-01

Previous studies have shown that soybean fermentation products can act as cancer chemoprevention or therapeutic agents. In this study, the anticancer activities of a fermentation product of soybean, black bean, and green bean mixture (BN999) were investigated. We found that BN999 inhibited the growth of human breast cancer AU565 cells and prostate adenocarcinoma PC-3 cells but not that of normal human cells. BN999 induced apoptosis in various human cancer cells but not in normal human cells. BN999 treatment of AU565 cancer cells resulted in activation of calpain and caspase-8, -9, and -3, suggesting that BN999 induces apoptosis via receptor-, mitochondria-, and endoplasmic reticulum-mediated pathways. Finally, we showed that BN999 inhibited the growth of mouse CT-26 colon cancer xenografts in syngenic BALB/c mice without causing obvious side effects. Together, these data suggest that BN999 has potential to be used as a cancer chemoprevention or therapeutic agent.

The transcription factor Wilms tumor 1 confers resistance in myeloid leukemia cells against the proapoptotic therapeutic agent TRAIL (tumor necrosis factor α-related apoptosis-inducing ligand) by regulating the antiapoptotic protein Bcl-xL.

PubMed

Bansal, Hima; Seifert, Theresea; Bachier, Carlos; Rao, Manjeet; Tomlinson, Gail; Iyer, Swaminathan Padmanabhan; Bansal, Sanjay

2012-09-21

Tumor necrosis factor α-related apoptosis-inducing ligand (TRAIL) is considered a promising cancer therapeutic agent due to its ability to induce apoptosis in a variety of cancer cells, while sparing normal cells. However, many human tumors including acute myeloid leukemia (AML) are partially or completely resistant to monotherapy with TRAIL, limiting its therapeutic utility. Therefore, identification of factors that contribute to TRAIL resistance may facilitate future development of more effective TRAIL-based cancer therapies. Here, we report a previously unknown role for WT1 in mediating TRAIL resistance in leukemia. Knockdown of WT1 with shRNA rendered TRAIL-resistant myeloid leukemia cells sensitive to TRAIL-induced cell death, and re-expression of shRNA-resistant WT1 restored TRAIL resistance. Notably, TRAIL-mediated apoptosis in WT1-silenced cells was largely due to down-regulation of the antiapoptotic protein Bcl-xL. Moreover, WT1 expression strongly correlated with overexpression of Bcl-xL in AML cell lines and blasts from AML patients. Furthermore, we found that WT1 transactivates Bcl-xL by directly binding to its promoter. We previously showed that WT1 is a novel client protein of heat shock protein 90 (Hsp90). Consistent with this, pharmacological inhibition of Hsp90 resulted in reduced WT1 and Bcl-xL expression leading to increased sensitivity of leukemia cells to TRAIL-mediated apoptosis. Collectively, our results suggest that WT1-dependent Bcl-xL overexpression contributes to TRAIL resistance in myeloid leukemias.

Hydrostatic pressure enhances mitomycin C induced apoptosis in urothelial carcinoma cells.

PubMed

Chen, Shao-Kuan; Chung, Chih-Ang; Cheng, Yu-Che; Huang, Chi-Jung; Ruaan, Ruoh-Chyu; Chen, Wen-Yih; Li, Chuan; Tsao, Chia-Wen; Hu, Wei-Wen; Chien, Chih-Cheng

2014-01-01

Urothelial carcinoma (UC) of the bladder is the second most common cancer of the genitourinary system. Clinical UC treatment usually involves transurethral resection of the bladder tumor followed by adjuvant intravesical immunotherapy or chemotherapy to prevent recurrence. Intravesical chemotherapy induces fewer side effects than immunotherapy but is less effective at preventing tumor recurrence. Improvement to intravesical chemotherapy is, therefore, needed. Cellular effects of mitomycin C (MMC) and hydrostatic pressure on UC BFTC905 cells were assessed. The viability of the UC cells was determined using cellular proliferation assay. Changes in apoptotic function were evaluated by caspase 3/7 activities, expression of FasL, and loss of mitochondrial membrane potential. Reduced cell viability was associated with increasing hydrostatic pressure. Caspase 3/7 activities were increased following treatment of the UC cells with MMC or hydrostatic pressure. In combination with 10 kPa hydrostatic pressure, MMC treatment induced increasing FasL expression. The mitochondria of UC cells displayed increasingly impaired membrane potentials following a combined treatment with 10 μg/ml MMC and 10 kPa hydrostatic pressure. Both MMC and hydrostatic pressure can induce apoptosis in UC cells through an extrinsic pathway. Hydrostatic pressure specifically increases MMC-induced apoptosis and might minimize the side effects of the chemotherapy by reducing the concentration of the chemical agent. This study provides a new and alternative approach for treatment of patients with UC following transurethral resection of the bladder tumor. Copyright © 2014 Elsevier Inc. All rights reserved.

Cytoprotection by fructose and other ketohexoses during bile salt-induced apoptosis of hepatocytes.

PubMed

Zeid, I M; Bronk, S F; Fesmier, P J; Gores, G J

1997-01-01

Toxic bile salts cause hepatocyte necrosis at high concentrations and apoptosis at lower concentrations. Although fructose prevents bile salt-induced necrosis, the effect of fructose on bile salt-induced apoptosis is unclear. Our aim was to determine if fructose also protects against bile salt-induced apoptosis. Fructose inhibited glycochenodeoxycholate (GCDC)-induced apoptosis in a concentration-dependent manner with a maximum inhibition of 72% +/- 10% at 10 mmol/L. First, we determined if fructose inhibited apoptosis by decreasing adenosine triphosphate (ATP) and intracellular pH (pHi). Although fructose decreased ATP to <25% of basal values, oligomycin (an ATP synthase inhibitor) did not inhibit apoptosis despite decreasing ATP to similar values. Fructose (10 mmol/L) decreased intracellular pH (pHi) by 0.2 U. However, extracellular acidification (pH 6.8), which decreased hepatocyte pHi 0.35 U and is known to inhibit necrosis, actually potentiated apoptosis 1.6-fold. Fructose cytoprotection also could not be explained by induction of bcl-2 transcription or metal chelation. Because we could not attribute fructose cytoprotection to metabolic effects, alterations in the expression of bcl-2, or metal chelation, we next determined if the poorly metabolized ketohexoses, tagatose and sorbose, also inhibited apoptosis; unexpectedly, both ketohexoses inhibited apoptosis. Because bile salt-induced apoptosis and necrosis are inhibited by fructose, these data suggest that similar processes initiate bile salt-induced hepatocyte necrosis and apoptosis. In contrast, acidosis, which inhibits necrosis, potentiates apoptosis. Thus, ketohexose-sensitive pathways appear to initiate both bile salt-induced cell apoptosis and necrosis, whereas dissimilar, pH-sensitive, effector mechanisms execute these two different cell death processes.

TG-interacting factor transcriptionally induced by AKT/FOXO3A is a negative regulator that antagonizes arsenic trioxide-induced cancer cell apoptosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Zi-Miao; Tseng, Hong-Yu; Cheng, Ya-Ling

2015-05-15

Arsenic trioxide (ATO) is a multi-target drug approved by the Food and Drug Administration as the first-line chemotherapeutic agent for the treatment of acute promyelocytic leukemia. In addition, several clinical trials are being conducted with arsenic-based drugs for the treatment of other hematological malignancies and solid tumors. However, ATO's modest clinical efficacy on some cancers, and potential toxic effects on humans have been reported. Determining how best to reduce these adverse effects while increasing its therapeutic efficacy is obviously a critical issue. Previously, we demonstrated that the JNK-induced complex formation of phosphorylated c-Jun and TG-interacting factor (TGIF) antagonizes ERK-induced cyclin-dependentmore » kinase inhibitor CDKN1A (p21{sup WAF1/CIP1}) expression and resultant apoptosis in response to ATO in A431 cells. Surprisingly, at low-concentrations (0.1–0.2 μM), ATO increased cellular proliferation, migration and invasion, involving TGIF expression, however, at high-concentrations (5–20 μM), ATO induced cell apoptosis. Using a promoter analysis, TGIF was transcriptionally regulated by ATO at the FOXO3A binding site (− 1486 to − 1479 bp) via the c-Src/EGFR/AKT pathway. Stable overexpression of TGIF promoted advancing the cell cycle into the S phase, and attenuated 20 μM ATO-induced apoptosis. Furthermore, blockage of the AKT pathway enhanced ATO-induced CDKN1A expression and resultant apoptosis in cancer cells, but overexpression of AKT1 inhibited CDKN1A expression. Therefore, we suggest that TGIF is transcriptionally regulated by the c-Src/EGFR/AKT pathway, which plays a role as a negative regulator in antagonizing ATO-induced CDKN1A expression and resultant apoptosis. Suppression of these antagonistic effects might be a promising therapeutic strategy toward improving clinical efficacy of ATO. - Highlights: • ATO-induced biphasic survival responses of cancer cells depend on low- or high-concentrations. • TGIF

Calpain mediates AIF-regulated caspase-independent pathway in cisplatin-induced apoptosis

NASA Astrophysics Data System (ADS)

Liu, Lei; Xing, Da; Chen, Wei R.

2007-11-01

Mitochondrial apoptosis inducing factor (AIF) on activation can translocate to the nucleus and induce cell death via caspase-independent pathway in cisplatin-induced apoptosis. Yet the precise signal transduction pathway(s) which regulates AIF-induced apoptotic pathway still remains poorly understood. In this study, we investigated the molecular mechanism of AIF release and redistribution in cisplatin-induced apoptosis in living ASTC-a-1 cells, as assessed by real-time anlysis. Herein, We report that during cisplatin-induced apoptosis, calpain activation, as measured in intact cells by a fluorescent substrates, is an early event, taking place well before AIF release and caspase-3 activation. Confocal imaging of the cells transfected with AIF-GFP demonstrated that AIF release occurred about 9 h after cisplatin treatment. The event proceeded progressively over time, coinciding with a nuclear translocation and lasting for more than 2 hours. AIF release and redistribution were effectively inhibited in samples co-treated with calpeptin and PD150606, two selective calpain inhibitors. Therefore, our results clearly show the kinetics of AIF release and redistribution in cisplatin-induced apoptosis in living ASTC-a-1 cells, and calpain played a crucial role in these events.

Bcl-2 prevents loss of mitochondria in CCCP-induced apoptosis.

PubMed

de Graaf, Aniek O; van den Heuvel, Lambert P; Dijkman, Henry B P M; de Abreu, Ronney A; Birkenkamp, Kim U; de Witte, Theo; van der Reijden, Bert A; Smeitink, Jan A M; Jansen, Joop H

2004-10-01

Bcl-2 family proteins regulate apoptosis at the level of mitochondria. To examine the mechanism of Bcl-2 function, we investigated the effects of the protonophore carbonyl cyanide m-chlorophenyl hydrazone (CCCP) on two hematopoietic cell lines and Bcl-2 overexpressing transfectants. CCCP directly interferes with mitochondrial function and induces apoptosis. We show that Bcl-2 inhibits apoptosis and that the antiapoptotic effect of Bcl-2 takes place upstream of caspase activation and nuclear changes associated with apoptosis, since these were markedly inhibited in cells overexpressing Bcl-2. Bcl-2 does not prevent the decrease in mitochondrial membrane potential nor the alterations in cellular ATP content induced by CCCP in FL5.12 and Jurkat cells. A higher number of mitochondria was observed in untreated Bcl-2 transfected cells compared to parental cells, as shown by electron microscopy. Exposure to CCCP induced a dramatic decrease in the number of mitochondria and severely disrupted mitochondrial ultrastructure, with apparent swelling and loss of cristae in parental cells. Bcl-2 clearly diminished the disruption of mitochondrial structure and preserved a higher number of mitochondria. These data suggest that CCCP induces apoptosis by structural disruption of mitochondria and that Bcl-2 prevents apoptosis and mitochondrial degeneration by preserving mitochondrial integrity.

Neem oil limonoids induces p53-independent apoptosis and autophagy

PubMed Central

Chandra, Dhyan

2012-01-01

Azadirachta indica, commonly known as neem, has a wide range of medicinal properties. Neem extracts and its purified products have been examined for induction of apoptosis in multiple cancer cell types; however, its underlying mechanisms remain undefined. We show that neem oil (i.e., neem), which contains majority of neem limonoids including azadirachtin, induced apoptotic and autophagic cell death. Gene silencing demonstrated that caspase cascade was initiated by the activation of caspase-9, whereas caspase-8 was also activated late during neem-induced apoptosis. Pretreatment of cancer cells with pan caspase inhibitor, z-VAD inhibited activities of both initiator caspases (e.g., caspase-8 and -9) and executioner caspase-3. Neem induced the release of cytochrome c and apoptosis-inducing factor (AIF) from mitochondria, suggesting the involvement of both caspase-dependent and AIF-mediated apoptosis. p21 deficiency caused an increase in caspase activities at lower doses of neem, whereas p53 deficiency did not modulate neem-induced caspase activation. Additionally, neem treatment resulted in the accumulation of LC3-II in cancer cells, suggesting the involvement of autophagy in neem-induced cancer cell death. Low doses of autophagy inhibitors (i.e., 3-methyladenine and LY294002) did not prevent accumulation of neem-induced LC3-II in cancer cells. Silencing of ATG5 or Beclin-1 further enhanced neem-induced cell death. Phosphoinositide 3-kinase (PI3K) or autophagy inhibitors increased neem-induced caspase-3 activation and inhibition of caspases enhanced neem-induced autophagy. Together, for the first time, we demonstrate that neem induces caspase-dependent and AIF-mediated apoptosis, and autophagy in cancer cells. PMID:22915764

Neem oil limonoids induces p53-independent apoptosis and autophagy.

PubMed

Srivastava, Pragya; Yadav, Neelu; Lella, Ravi; Schneider, Andrea; Jones, Anthony; Marlowe, Timothy; Lovett, Gabrielle; O'Loughlin, Kieran; Minderman, Hans; Gogada, Raghu; Chandra, Dhyan

2012-11-01

Azadirachta indica, commonly known as neem, has a wide range of medicinal properties. Neem extracts and its purified products have been examined for induction of apoptosis in multiple cancer cell types; however, its underlying mechanisms remain undefined. We show that neem oil (i.e., neem), which contains majority of neem limonoids including azadirachtin, induced apoptotic and autophagic cell death. Gene silencing demonstrated that caspase cascade was initiated by the activation of caspase-9, whereas caspase-8 was also activated late during neem-induced apoptosis. Pretreatment of cancer cells with pan caspase inhibitor, z-VAD inhibited activities of both initiator caspases (e.g., caspase-8 and -9) and executioner caspase-3. Neem induced the release of cytochrome c and apoptosis-inducing factor (AIF) from mitochondria, suggesting the involvement of both caspase-dependent and AIF-mediated apoptosis. p21 deficiency caused an increase in caspase activities at lower doses of neem, whereas p53 deficiency did not modulate neem-induced caspase activation. Additionally, neem treatment resulted in the accumulation of LC3-II in cancer cells, suggesting the involvement of autophagy in neem-induced cancer cell death. Low doses of autophagy inhibitors (i.e., 3-methyladenine and LY294002) did not prevent accumulation of neem-induced LC3-II in cancer cells. Silencing of ATG5 or Beclin-1 further enhanced neem-induced cell death. Phosphoinositide 3-kinase (PI3K) or autophagy inhibitors increased neem-induced caspase-3 activation and inhibition of caspases enhanced neem-induced autophagy. Together, for the first time, we demonstrate that neem induces caspase-dependent and AIF-mediated apoptosis, and autophagy in cancer cells.

Role of the apoptosis pathway in cryopreservation-induced cell death in mesenchymal stem cells derived from umbilical cord blood.

PubMed

Bissoyi, Akalabya; Pramanik, Krishna

2014-08-01

Cryopreservation of mesenchymal stem cells (MSCs) is important because of their commercial applications in the clinical sector. MSCs are vulnerable to cryopreservation-induced apoptosis due to activation of apoptosis-related proteins during thawing. But the relationship between cryopreservation and apoptosis is not well understood. MSCs derived from umbilical cord blood were cryopreserved using Me2SO as the cryoprotective agent, with or without pre-treatment with the general caspase inhibitor z-VAD-FMK, or with the more selective caspase inhibitors z-IETD-FMK, z-LEHD-FMK and z-DEVD-FMK. To evaluate the effect of the calcium-mediated pathway, cryopreserved MSCs were tested with and without a calpain inhibitor. FACS was used to measure cell viability, mitochondrial membrane potential, and cell cycle analysis. Processing of the pro-caspases-3, -8, -9, calpain and Bid were determined by Western blotting. Cryopreservation of MSCs resulted in characteristic apoptosis within 24 h after thawing. Results show that intrinsic, extrinsic, and calpain pathways are activated after cryopreserved MSCs are thawed. Compared to selective caspase inhibitors, a general caspase inhibitor blocked DNA degradation more effectively and also inhibited caspases-3 and -8 processing as well as Bid cleavage, showing the beneficial effect of reducing cryopreservation-induced apoptosis. Similarly, calpain inhibition reduced cryopreservation-induced apoptosis. These data indicate that caspase-mediated extrinsic and intrinsic pathways and the proteolytic calpain cascade were activated after cryopreservation using a standard cryopreservation protocol. This activation might play an important role in the process of cryopreservation-induced cell death. Furthermore, the inhibition of calpain activity and caspase-mediated pathways might improve preservation efficacy.

Propofol ameliorates doxorubicin-induced oxidative stress and cellular apoptosis in rat cardiomyocytes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lai, H.C.; Department of Medicine and Cardiovascular Research Center, National Yang-Ming University School of Medicine, Taipei, Taiwan; Yeh, Y.C.

2011-12-15

Background: Propofol is an anesthetic with pluripotent cytoprotective properties against various extrinsic insults. This study was designed to examine whether this agent could also ameliorate the infamous toxicity of doxorubicin, a widely-used chemotherapeutic agent against a variety of cancer diseases, on myocardial cells. Methods: Cultured neonatal rat cardiomyocytes were administrated with vehicle, doxorubicin (1 {mu}M), propofol (1 {mu}M), or propofol plus doxorubicin (given 1 h post propofol). After 24 h, cells were harvested and specific analyses regarding oxidative/nitrative stress and cellular apoptosis were conducted. Results: Trypan blue exclusion and MTT assays disclosed that viability of cardiomyocytes was significantly reduced bymore » doxorubicin. Contents of reactive oxygen and nitrogen species were increased and antioxidant enzymes SOD1, SOD2, and GPx were decreased in these doxorubicin-treated cells. Mitochondrial dehydrogenase activity and membrane potential were also depressed, along with activation of key effectors downstream of mitochondrion-dependent apoptotic signaling. Besides, abundance of p53 was elevated and cleavage of PKC-{delta} was induced in these myocardial cells. In contrast, all of the above oxidative, nitrative and pro-apoptotic events could be suppressed by propofol pretreatment. Conclusions: Propofol could extensively counteract oxidative/nitrative and multiple apoptotic effects of doxorubicin in the heart; hence, this anesthetic may serve as an adjuvant agent to assuage the untoward cardiac effects of doxorubicin in clinical application. -- Highlights: Black-Right-Pointing-Pointer We evaluate how propofol prevents doxorubicin-induced toxicity in cardiomyocytes. Black-Right-Pointing-Pointer Propofol reduces doxorubicin-imposed nitrative and oxidative stress. Black-Right-Pointing-Pointer Propofol suppresses mitochondrion-, p53- and PKC-related apoptotic signaling. Black-Right-Pointing-Pointer Propofol ameliorates apoptosis and

Quercetin induces apoptosis of Trypanosoma brucei gambiense and decreases the proinflammatory response of human macrophages.

PubMed

Mamani-Matsuda, Maria; Rambert, Jérôme; Malvy, Denis; Lejoly-Boisseau, Hélène; Daulouède, Sylvie; Thiolat, Denis; Coves, Sara; Courtois, Pierrette; Vincendeau, Philippe; Mossalayi, M Djavad

2004-03-01

In addition to parasite spread, the severity of disease observed in cases of human African trypanosomiasis (HAT), or sleeping sickness, is associated with increased levels of inflammatory mediators, including tumor necrosis factor (TNF)-alpha and nitric oxide derivatives. In the present study, quercetin (3,3',4',5,7-pentahydroxyflavone), a potent immunomodulating flavonoid, was shown to directly induce the death of Trypanosoma brucei gambiense, the causative agent of HAT, without affecting normal human cell viability. Quercetin directly promoted T. b. gambiense death by apoptosis as shown by Annexin V binding. In addition to microbicidal activity, quercetin induced dose-dependent decreases in the levels of TNF-alpha and nitric oxide produced by activated human macrophages. These results highlight the potential use of quercetin as an antimicrobial and anti-inflammatory agent for the treatment of African trypanomiasis.

The role of cPLA2 in Methylglyoxal-induced cell apoptosis of HUVECs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yuan, Jie; Zhu, Chao; Hong, Yali

2017-05-15

Methylglyoxal (MGO), a highly reactive dicarbonyl compound, is mainly formed as a byproduct of glycolysis. Elevated MGO level is known to induce apoptosis of vascular endothelial cells, which is implicated with progression of atherosclerosis and diabetic complications. However, the underlying mechanisms have not been exhaustively investigated yet. Here, we further characterized the mechanisms how MGO induced apoptosis in human umbilical vein endothelial cells (HUVECs). Our data revealed that cytosolic phospholipase A2 (cPLA2) played an important role in MGO-induced cell apoptosis. It was found that MGO could increase both the activity and expression of cPLA2. Inhibition of cPLA2 by Pyrrophenone (PYR)more » or siRNA significantly attenuated the MGO-induced apoptosis. Additionally, MGO time-dependently decreased the phosphorylation of nuclear factor κB (NF-κB). Pretreatment of the cells with NF-κB inhibitor, BAY11-7082, further increased MGO-induced apoptosis of HUVECs, indicating that NF-κB played a survival role in this MGO-induced apoptosis. Furthermore, in the presence of si-cPLA2 or PYR, MGO no longer decreased NF-κB phosphorylation. Beyond that, the antioxidant N-acetyl cysteine (NAC) could reverse the changes of both cPLA2 and NF-κB caused by MGO. p38, the upstream of cPLA2, was also significantly phosphorylated by MGO. However, p38 inhibitor failed to reverse the apoptosis induced by MGO. This study gives an important insight into the downstream signaling mechanisms of MGO, cPLA2-NF-κB, in endothelial apoptosis. - Highlights: • cPLA2 participated in MGO-induced HUVECs apoptosis. • Inhibition of NF-κB was involved in MGO-cPLA2-mediated cell apoptosis. • Antioxidant NAC attenuated MGO-induced cPLA2 activation and cell apoptosis.« less

Interdependence of Bad and Puma during ionizing-radiation-induced apoptosis.

PubMed

Toruno, Cristhian; Carbonneau, Seth; Stewart, Rodney A; Jette, Cicely

2014-01-01

Ionizing radiation (IR)-induced DNA double-strand breaks trigger an extensive cellular signaling response that involves the coordination of hundreds of proteins to regulate DNA repair, cell cycle arrest and apoptotic pathways. The cellular outcome often depends on the level of DNA damage as well as the particular cell type. Proliferating zebrafish embryonic neurons are highly sensitive to IR-induced apoptosis, and both p53 and its transcriptional target puma are essential mediators of the response. The BH3-only protein Puma has previously been reported to activate mitochondrial apoptosis through direct interaction with the pro-apoptotic Bcl-2 family proteins Bax and Bak, thus constituting the role of an "activator" BH3-only protein. This distinguishes it from BH3-only proteins like Bad that are thought to indirectly promote apoptosis through binding to anti-apoptotic Bcl-2 family members, thereby preventing the sequestration of activator BH3-only proteins and allowing them to directly interact with and activate Bax and Bak. We have shown previously that overexpression of the BH3-only protein Bad in zebrafish embryos supports normal embryonic development but greatly sensitizes developing neurons to IR-induced apoptosis. While Bad has previously been shown to play only a minor role in promoting IR-induced apoptosis of T cells in mice, we demonstrate that Bad is essential for robust IR-induced apoptosis in zebrafish embryonic neural tissue. Moreover, we found that both p53 and Puma are required for Bad-mediated radiosensitization in vivo. Our findings show the existence of a hierarchical interdependence between Bad and Puma whereby Bad functions as an essential sensitizer and Puma as an essential activator of IR-induced mitochondrial apoptosis specifically in embryonic neural tissue.

Cytosolic NADP(+)-dependent isocitrate dehydrogenase regulates cadmium-induced apoptosis.

PubMed

Shin, Seoung Woo; Kil, In Sup; Park, Jeen-Woo

2010-04-01

Cadmium ions have a high affinity for thiol groups. Therefore, they may disturb many cellular functions. We recently reported that cytosolic NADP(+)-dependent isocitrate dehydrogenase (IDPc) functions as an antioxidant enzyme to supply NADPH, a major source of reducing equivalents to the cytosol. Cadmium decreased the activity of IDPc both as a purified enzyme and in cultured cells. In the present study, we demonstrate that the knockdown of IDPc expression in HEK293 cells greatly enhances apoptosis induced by cadmium. Transfection of HEK293 cells with an IDPc small interfering RNA significantly decreased the activity of IDPc and enhanced cellular susceptibility to cadmium-induced apoptosis as indicated by the morphological evidence of apoptosis, DNA fragmentation and condensation, cellular redox status, mitochondria redox status and function, and the modulation of apoptotic marker proteins. Taken together, our results suggest that suppressing the expression of IDPc enhances cadmium-induced apoptosis of HEK293 cells by increasing disruption of the cellular redox status. Copyright 2009 Elsevier Inc. All rights reserved.

[Progress on mechanism of cell apoptosis induced by rubella virus].

PubMed

Li, Zhen-mei; Chu, Fu-lu; Liu, Ying; Wang, Zhi-yu

2013-09-01

Rubella virus (RV), a member of the family Togaviridae, can induce apoptosis of host cells in vitro. Protein kinases of the Ras-Raf-MEK-ERK pathway and PI3K-Akt pathway play essential roles in virus multiplication, cell survival and apoptosis. Proteins p53 and TAp63 that bind to specific DNA sequences stimulate Bax in a manner to produce functional pores that facilitate release of mitochondrial cytochrome c and downstream caspase activation. In this review, the molecular mechanisms of RV-induced cell apoptosis, including RV-infected cell lines, pathological changes in cell components and apoptosis signaling pathways are summarized.

A novel benzofuran derivative, ACDB, induces apoptosis of human chondrosarcoma cells through mitochondrial dysfunction and endoplasmic reticulum stress

PubMed Central

Su, Chen-Ming; Chen, Chien-Yu; Lu, Tingting; Sun, Yi; Li, Weimin; Huang, Yuan-Li; Tsai, Chun-Hao; Chang, Chih-Shiang; Tang, Chih-Hsin

2016-01-01

Chondrosarcoma is one of the bone tumor with high mortality in respond to poor radiation and chemotherapy treatment. Here, we analyze the antitumor activity of a novel benzofuran derivative, 2-amino-3-(2-chlorophenyl)-6-(4-dimethylaminophenyl)benzofuran-4-yl acetate (ACDB), in human chondrosarcoma cells. ACDB increased the cell apoptosis of human chondrosarcomas without harm in chondrocytes. ACDB also enhanced endoplasmic reticulum (ER) stress, which was characterized by varieties in the cytosolic calcium levels and induced the expression of glucose-regulated protein (GRP) and calpain. Furthermore, the ACDB-induced chondrosarcoma apoptosis was associated with the upregulation of the B cell lymphoma-2 (Bcl-2) family members including pro- and anti-apoptotic proteins, downregulation of dysfunctional mitochondria that released cytochrome C, and subsequent activation of caspases-3. In addition, the ACDB-mediated cellular apoptosis was suppressed by transfecting cells with glucose-regulated protein (GRP) and calpain siRNA or treating cells with ER stress chelators and caspase inhibitors. Interestingly, animal experiments illustrated a reduction in the tumor volume following ACDB treatment. Together, these results suggest that ACDB may be a novel tumor suppressor of chondrosarcoma, and this study demonstrates that the novel antitumor agent, ACDB, induced apoptosis by mitochondrial dysfunction and ER stress in human chondrosarcoma cells in vitro and in vivo. PMID:27835579

A novel benzofuran derivative, ACDB, induces apoptosis of human chondrosarcoma cells through mitochondrial dysfunction and endoplasmic reticulum stress.

PubMed

Su, Chen-Ming; Chen, Chien-Yu; Lu, Tingting; Sun, Yi; Li, Weimin; Huang, Yuan-Li; Tsai, Chun-Hao; Chang, Chih-Shiang; Tang, Chih-Hsin

2016-12-13

Chondrosarcoma is one of the bone tumor with high mortality in respond to poor radiation and chemotherapy treatment. Here, we analyze the antitumor activity of a novel benzofuran derivative, 2-amino-3-(2-chlorophenyl)-6-(4-dimethylaminophenyl)benzofuran-4-yl acetate (ACDB), in human chondrosarcoma cells. ACDB increased the cell apoptosis of human chondrosarcomas without harm in chondrocytes. ACDB also enhanced endoplasmic reticulum (ER) stress, which was characterized by varieties in the cytosolic calcium levels and induced the expression of glucose-regulated protein (GRP) and calpain. Furthermore, the ACDB-induced chondrosarcoma apoptosis was associated with the upregulation of the B cell lymphoma-2 (Bcl-2) family members including pro- and anti-apoptotic proteins, downregulation of dysfunctional mitochondria that released cytochrome C, and subsequent activation of caspases-3. In addition, the ACDB-mediated cellular apoptosis was suppressed by transfecting cells with glucose-regulated protein (GRP) and calpain siRNA or treating cells with ER stress chelators and caspase inhibitors. Interestingly, animal experiments illustrated a reduction in the tumor volume following ACDB treatment. Together, these results suggest that ACDB may be a novel tumor suppressor of chondrosarcoma, and this study demonstrates that the novel antitumor agent, ACDB, induced apoptosis by mitochondrial dysfunction and ER stress in human chondrosarcoma cells in vitro and in vivo.

Bim directly antagonizes Bcl-xl in doxorubicin-induced prostate cancer cell apoptosis independently of p53.

PubMed

Yang, Min-Chi; Lin, Ru-Wei; Huang, Shih-Bo; Huang, Shin-Yuan; Chen, Wen-Jie; Wang, Shiaw; Hong, Yi-Ren; Wang, Chihuei

2016-01-01

Doxorubicin and other anthracycline compounds exert their anti-cancer effects by causing DNA damage and initiating cell cycle arrest in cancer cells, followed by apoptosis. DNA damage generally activates a p53-mediated pathway to initiate apoptosis by increasing the level of the BH3-only protein, Puma. However, p53-mediated apoptosis in response to DNA damage has not yet been validated in prostate cancers. In the current study, we used LNCaP and PC3 prostate cancer cells, representing wild type p53 and a p53-null model, to determine if DNA damage activates p53-mediated apoptosis in prostate cancers. Our results revealed that PC3 cells were 4 to 8-fold less sensitive than LNCaP cells to doxorubicin-inuced apoptosis. We proved that the differential response of LNCaP and PC3 to doxorubicin was p53-independent by introducing wild-type or dominant negative p53 into PC3 or LNCaP cells, respectively. By comparing several apoptosis-related proteins in both cell lines, we found that Bcl-xl proteins were much more abundant in PC3 cells than in LNCaP cells. We further demonstrated that Bcl-xl protects LNCaP and PC3 cells from doxorubicin-induced apoptosis by using ABT-263, an inhibitor of Bcl-xl, as a single agent or in combination with doxorubicin to treat LNCaP or PC3 cells. Bcl-xl rather than p53, likely contributes to the differential response of LNCaP and PC3 to doxorubicin in apoptosis. Finally, co-immunoprecipitation and siRNA analysis revealed that a BH3-only protein, Bim, is involved in doxorubicin-induced apoptosis by directly counteracting Bcl-xl.

Apoptosis of lactotrophs induced by D2 receptor activation is estrogen dependent.

PubMed

Radl, Daniela B; Zárate, Sandra; Jaita, Gabriela; Ferraris, Jimena; Zaldivar, Verónica; Eijo, Guadalupe; Seilicovich, Adriana; Pisera, Daniel

2008-01-01

Dopamine (DA) inhibits prolactin release and reduces lactotroph proliferation by activating D2 receptors. DA and its metabolite, 6-hydroxydopamine (6-OHDA), induce apoptosis in different cell types. DA receptors and DA transporter (DAT) were implicated in this action. Considering that estradiol sensitizes anterior pituitary cells to proapoptotic stimuli, we investigated the effect of estradiol on the apoptotic action of DA and 6-OHDA in anterior pituitary cells, and the involvement of the D2 receptor and DAT in the proapoptotic effect of DA. Viability of cultured anterior pituitary cells from ovariectomized rats was determined by MTS assay. Apoptosis was evaluated by Annexin-V/flow cytometry and TUNEL. Lactotrophs were identified by immunocytochemistry. DA induced apoptosis of lactotrophs in an estrogen-dependent manner. In contrast, estradiol was not required to trigger the apoptotic action of 6-OHDA. Cabergoline, a D2 receptor agonist, induced lactotroph apoptosis, while sulpiride, a D2 receptor antagonist, blocked DA-induced cell death. The blockade of DAT by GBR12909 did not affect the apoptotic action of DA, but inhibited 6-OHDA-induced apoptosis. These data show that DA, through D2 receptor activation, induces apoptosis of estrogen-sensitized anterior pituitary cells, and suggest that DA contributes to the control of lactotroph number not only by inhibiting proliferation but also by inducing apoptosis. 2008 S. Karger AG, Basel.

Mitochondria-derived reactive oxygen species drive GANT61-induced mesothelioma cell apoptosis.

PubMed

Lim, Chuan Bian; Prêle, Cecilia M; Baltic, Svetlana; Arthur, Peter G; Creaney, Jenette; Watkins, D Neil; Thompson, Philip J; Mutsaers, Steven E

2015-01-30

Gli transcription factors of the Hedgehog (Hh) pathway have been reported to be drivers of malignant mesothelioma (MMe) cell survival. The Gli inhibitor GANT61 induces apoptosis in various cancer cell models, and has been associated directly with Gli inhibition. However various chemotherapeutics can induce cell death through generation of reactive oxygen species (ROS) but whether ROS mediates GANT61-induced apoptosis is unknown. In this study human MMe cells were treated with GANT61 and the mechanisms regulating cell death investigated. Exposure of MMe cells to GANT61 led to G1 phase arrest and apoptosis, which involved ROS but not its purported targets, GLI1 or GLI2. GANT61 triggered ROS generation and quenching of ROS protected MMe cells from GANT61-induced apoptosis. Furthermore, we demonstrated that mitochondria are important in mediating GANT61 effects: (1) ROS production and apoptosis were blocked by mitochondrial inhibitor rotenone; (2) GANT61 promoted superoxide formation in mitochondria; and (3) mitochondrial DNA-deficient LO68 cells failed to induce superoxide, and were more resistant to apoptosis induced by GANT61 than wild-type cells. Our data demonstrate for the first time that GANT61 induces apoptosis by promoting mitochondrial superoxide generation independent of Gli inhibition, and highlights the therapeutic potential of mitochondrial ROS-mediated anticancer drugs in MMe.

Icariside II-induced mitochondrion and lysosome mediated apoptosis is counterbalanced by an autophagic salvage response in hepatoblastoma.

PubMed

Geng, Ya-di; Zhang, Chao; Shi, Ya-Min; Xia, Yuan-Zheng; Guo, Chao; Yang, Lei; Kong, Ling-Yi

2015-09-28

In this study, the anti-cancer effect of Icariside II (IS), a natural plant flavonoid, against hepatoblastoma cells and the underlying mechanisms were investigated. The in vitro and in vivo studies show that IS decreased the viability of human hepatoblastoma HepG2 cells in a concentration- and time-dependent manner and inhibited tumor growth in mice transplanted with H22 liver carcinomas. IS impaired mitochondria and lysosomes as evidenced by signs of induced mitochondrial and lysosomal membrane permeabilization, resulting in caspase activation and apoptosis. SQSTM1 up-regulation and autophagic flux measurements demonstrated that IS exposure also impaired autophagosome degradation which resulted in autophagosome accumulation, which plays a pro-survival role as the genetic knockdown of LC3B further sensitized the IS-treated cells. Electron microscopy images showed that autophagosome engulfs IS-impaired mitochondria and lysosomes, thus blocking cytotoxicity induced by further leakage of the hydrolases from lysosomes and pro-apoptosis members from mitochondria. In conclusion, these data suggest that IS plays multiple roles as a promising chemotherapeutic agent that induces cell apoptosis involving both mitochondrial and lysosomal damage. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

A novel natural compound, a cycloanthranilylproline derivative (Fuligocandin B), sensitizes leukemia cells to apoptosis induced by tumor necrosis factor related apoptosis-inducing ligand (TRAIL) through 15-deoxy-Delta 12, 14 prostaglandin J2 production.

PubMed

Hasegawa, Hiroo; Yamada, Yasuaki; Komiyama, Kanki; Hayashi, Masahiko; Ishibashi, Masami; Sunazuka, Toshiaki; Izuhara, Takeshi; Sugahara, Kazuyuki; Tsuruda, Kazuto; Masuda, Masato; Takasu, Nobuyuki; Tsukasaki, Kunihiro; Tomonaga, Masao; Kamihira, Shimeru

2007-09-01

Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) induces apoptosis in many transformed cells; however, not all human tumors respond to TRAIL, potentially limiting its therapeutic utility. Although there is substantial evidence that cytotoxic drugs can augment sensitivity to TRAIL, it has become important to know what kinds of nontoxic drugs can be used together with TRAIL. We thus screened several natural compounds that can overcome resistance to TRAIL and found that a cycloanthranilylproline derivative, Fuligocandin B (FCB), an extract of myxomycete Fuligo candida, exhibited significant synergism with TRAIL. Treatment of the TRAIL-resistant cell line KOB with FCB and TRAIL resulted in apparent apoptosis, which was not induced by either agent alone. FCB increased the production of 15-deoxy-Delta(12,14) prostaglandin J(2) (15d-PGJ(2)), an endogenous PPAR gamma ligand, through activation of cyclooxygenase-2 (COX-2). This unique mechanism highlighted the fact that 15d-PGJ(2) directly enhanced sensitivity to TRAIL by inhibiting multiple antiapoptotic factors. More importantly, similar effects were observed in other leukemia cell lines irrespective of their origin. The enhancement was observed regardless of PPAR gamma expression and was not blocked even by peroxisome proliferator-activated receptor-gamma (PPAR gamma) siRNA. These results indicate that 15d-PGJ(2) sensitizes TRAIL-resistant cells to TRAIL in a PPAR gamma-independent manner and that the use of 15d-PGJ(2) or its inducers, such as FCB, is a new strategy for cancer therapy.

Shikonin induces apoptosis and inhibits migration of ovarian carcinoma cells by inhibiting the phosphorylation of Src and FAK

PubMed Central

HAO, ZHENFENG; QIAN, JING; YANG, JISHI

2015-01-01

The present study identified that shikonin, a naphthoquinone extracted from the roots of Lithospermum erythrorhizon, inhibits the migration of ovarian cancer cells and induces their apoptosis by impairing the phosphorylation of two kinases, proto-oncogene tyrosine protein kinase Src (Src) and focal adhesion kinase (FAK). Ovarian carcinoma SKOV-3 cells were treated with various concentrations of shikonin and analyzed for the effects on cell migration, invasion and apoptosis via Transwell assays and flow cytometry. In addition, the effects of shikonin administration on the expression and phosphorylation of Src and FAK in the SKOV-3 cells were analyzed by western blotting. Shikonin appeared to induce apoptosis and decrease cell migration in the SKOV-3 ovarian cells. Furthermore, the present study provides evidence that shikonin may exert these effects on human ovarian carcinoma cells via the inhibition of the protein tyrosine kinases, Src and FAK. Thus, shikonin should be considered for additional investigation as a candidate agent for the prevention and treatment of human ovarian cancer. PMID:25621031

Glucocorticoid receptor activation inhibits p53-induced apoptosis of MCF10Amyc cells via induction of protein kinase Cε.

PubMed

Aziz, Moammir H; Shen, Hong; Maki, Carl G

2012-08-24

Glucocorticoid receptor (GR) is a ligand-dependent transcription factor that can promote apoptosis or survival in a cell-specific manner. Activated GR has been reported to inhibit apoptosis in mammary epithelial cells and breast cancer cells by increasing pro-survival gene expression. In this study, activated GR inhibited p53-dependent apoptosis in MCF10A cells and human mammary epithelial cells that overexpress the MYC oncogene. Specifically, GR agonists hydrocortisone or dexamethasone inhibited p53-dependent apoptosis induced by cisplatin, ionizing radiation, or the MDM2 antagonist Nutlin-3. In contrast, the GR antagonist RU486 sensitized the cells to apoptosis by these agents. Apoptosis inhibition was associated with maintenance of mitochondrial membrane potential, diminished caspase-3 and -7 activation, and increased expression at both the mRNA and protein level of the anti-apoptotic PKC family member PKCε. Knockdown of PKCε via siRNA targeting reversed the protective effect of dexamethasone and restored apoptosis sensitivity. These data provide evidence that activated GR can inhibit p53-dependent apoptosis through induction of the anti-apoptotic factor PKCε.

Autophagy regulates chlorpyrifos-induced apoptosis in SH-SY5Y cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Park, Jae Hyeon; Hanyang Biomedical Research Institute, Seoul; Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul

Recent studies have shown that up-regulation of autophagy may be a tractable therapeutic intervention for clearing disease-causing proteins, including α-synuclein, ubiquitin, and other misfolded or aggregated proteins in pesticide-induced neurodegeneration. In a previous study, we reported that chlorpyrifos (CPF)-induced mitochondria-dependent apoptosis is mediated through reactive oxygen species in SH-SY5Y cells. In this study, we explored a novel pharmacotherapeutic approach to prevent CPF neurotoxicity involving the regulation of autophagy. We investigated the modulation of CPF-induced apoptosis according to autophagy regulation. We found that CPF induced apoptosis in SH-SY5Y cells, as demonstrated by the activation of caspase-3 and nuclear condensation. In addition,more » we observed that cells treated with CPF underwent autophagic cell death by monitoring the expression of LC3-II and p62. Pretreatment with the autophagy inducer rapamycin significantly enhanced the cell viability of CPF-exposed cells, and the enhancement of cell viability was partially due to alleviation of CPF-induced apoptosis via a decrease in levels of cleaved caspase-3. Specifically, rapamycin pretreatment decreased Bax and increased Bcl-2 expression in mitochondria. In addition, rapamycin significantly decreased cytochrome c release in from mitochondria into the cytosol. However, pretreatment of cells with the autophagy inhibitor, 3-methyladenine (3MA), remarkably increased CPF toxicity in these cells; this with correlated with increased expression of Bax and decreased expression of Bcl-2 in mitochondria. Our results suggest that CPF-induced cytotoxicity is modified by autophagy regulation and that rapamycin protects against CPF-induced apoptosis by enhancing autophagy. Pharmacologic induction of autophagy by rapamycin may be a useful treatment strategy in neurodegenerative disorders. - Highlights: ► Chlorpyrifos (CPF) is cytotoxic to SH-SY5Y cells ► CPF-induced cytotoxicity is

Mitochondrial dysfunction in choline deficiency-induced apoptosis in cultured rat hepatocytes.

PubMed

Guo, Wei-Xing; Pye, Quentin N; Williamson, Kelly S; Stewart, Charles A; Hensley, Kenneth L; Kotake, Yashige; Floyd, Robert A; Broyles, Robert H

2005-09-01

Our recent studies have demonstrated that generation of ROS is associated with choline deficiency (CD)-induced apoptosis in CWSV-1 cells, an immortalized rat hepatocyte that becomes tumorigenic by stepwise culturing in decreasing levels of choline. In the present study, we investigated the effect of CD on loss of mitochondrial membrane potential (MMP), using the JC-1 probe by FASCAN assay. Our data demonstrate that MMP in CD-cultured cells was decreased in a time- and dose-dependent manner and that significant disruption occurred at 24 h, relative to high choline (HC, 70 microM) cultured cells. In order to investigate further the relationship among the CD-induced ROS, MMP collapse, and apoptosis, we examined the effects of different inhibitors on ROS production, MMP disruption, and apoptosis in CD or HC-cultured CWSV-1 cells. These data indicate that the disruption of MMP is an upstream event in CD-induced apoptosis, and mitochondrial dysfunction plays a key role in mediating CD-induced apoptosis in CWSV-1 cells.

Modulation of iridovirus-induced apoptosis by endocytosis, early expression, JNK, and apical caspase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chitnis, Nilesh S.; D'Costa, Susan M.; Paul, Eric R.

Chilo iridescent virus (CIV) is the type species for the family Iridoviridae, which are large, isometric, cytoplasmic dsDNA viruses. We examined the mechanism of apoptosis induction by CIV. High CIV doses (CIV{sub XS}; 400 {mu}g/ml), UV-irradiated virus (CIV{sub UV}; 10 {mu}g/ml) and CVPE (CIV protein extract; 10 {mu}g/ml) induced apoptosis in 60% of treated Choristoneura fumiferana (IPRI-CF-124T) cells. Normal doses of infectious CIV (10 {mu}g/ml) induced apoptosis in only 10% of C. fumiferana (CF) cells. Apoptosis was inhibited by Z-IETD-FMK, an apical caspase inhibitor, indicating that CIV-induced apoptosis requires caspase activity. The putative caspase in CF cells was designated Cf-caspase-i.more » CIV{sub UV} or CVPE enhanced Cf-caspase-i activity by 80% at 24 h relative to mock-treated cells. Since the MAP kinase pathway induces or inhibits apoptosis depending on the context, we used JNK inhibitor SP600125 and demonstrated drastic suppression of CVPE-induced apoptosis. Thus, the JNK signaling pathway is significant for apoptosis in this system. Virus interaction with the cell surface was not sufficient for apoptosis since CIV{sub UV} particles bound to polysterene beads failed to induce apoptosis. Endocytosis inhibitors (bafilomycin or ammonium chloride) negated apoptosis induction by CIV{sub UV}, CIV{sub XS} or CVPE indicating that entry through this mode is required. Given the weak apoptotic response to infectious CIV, we postulated that viral gene expression inhibited apoptosis. CIV infection of cells pretreated with cycloheximide induced apoptosis in 69% of the cells compared to 10% in normal infections. Furthermore, blocking viral DNA replication with aphidicolin or phosphonoacetic acid suppressed apoptosis and Cf-caspase-i activity, indicating that early viral expression is necessary for inhibition of apoptosis, and de novo synthesis of viral proteins is not required for induction. We show for the first time that, in a member of the family

3-Bromopyruvate and sodium citrate induce apoptosis in human gastric cancer cell line MGC-803 by inhibiting glycolysis and promoting mitochondria-regulated apoptosis pathway

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guo, Xingyu; Zhang, Xiaodong; Wang, Tingan, E-mail: moonsonlife@yahoo.com

Cancer cells are mainly dependent on glycolysis to generate adenosine triphosphate (ATP) and intermediates required for cell growth and proliferation. Thus, inhibition of glycolysis might be of therapeutic value in antitumor treatment. Our previously studies had found that both 3-bromopyruvate (BP) and sodium citrate (SCT) can inhibit tumor growth and proliferation in vitro and in vivo. However, the mechanism involved in the BP and SCT mediated antitumor activity is not entirely clear. In this work, it is demonstrated that BP inhibits the enzyme hexokinase (HK) activity and SCT suppresses the phosphofructokinase (PFK) activity respectively, both the two agents decrease viability, ATP generationmore » and lactate content in the human gastric cancer cell line MGC-803. These effects are directly correlated with blockage of glycolysis. Furthermore, BP and SCT can induce the characteristic manifestations of mitochondria-regulated apoptosis, such as down-regulation of anti-apoptosis proteins Bcl-2 and Survivin, up-regulation of pro-apoptosis protein Bax, activation of caspase-3, as well as leakage of cytochrome c (Cyt-c). In summary, our results provided evidences that BP and SCT inhibit the MGC-803 cells growth and proliferation might be correlated with inhibiting glycolysis and promoting mitochondria-regulated apoptosis. -- Highlights: •Blockage of glycolysis might be a novel way to anticancer. •Both 3-bromopyruvate and sodium citrate could inhibit glycolysis and regulate mitochondrial pathway in cancer cells. •Both 3-bromopyruvate and sodium citrate would be the novel agents on treatment of gastric cancer.« less

Phenformin inhibits cell proliferation and induces cell apoptosis and autophagy in cholangiocarcinoma.

PubMed

Hu, Shuyang; Ouyang, Qing; Cheng, Qingbao; Wang, Jinghan; Feng, Feiling; Qiao, Liang; Gan, Wei; Shi, Yang; Wu, Demin; Jiang, Xiaoqing

2018-04-01

Cholangiocarcinoma (CCA) is an aggressive malignant tumor and the prognosis of patients with advanced stage disease remains poor. Therefore, the identification of novel treatment agents for CCA is required. In the present study, the biological effects of the diabetes therapeutic agent, phenformin, in CCA cell lines was investigated. Cell Counting Kit‑8 cell viability, cellular clone formation and subcutaneous tumor formation assays were performed, which revealed that phenformin inhibited CCA cell proliferation and growth both in vitro and in vivo. In addition, phenformin induced CCA cell apoptosis and autophagy. Phenformin partly activated the liver kinase B1 (LKB1)/5' AMP‑activated protein kinase signaling pathway to exert its biological effects on CCA cell lines, as demonstrated by knockdown of LKB1, which reversed these effects. In conclusion, the present study demonstrated the biological effects of phenformin in CCA and suggested that phenformin may be a potential novel agent for CCA treatment.

Peroxisome proliferators induce apoptosis in hepatoma cells.

PubMed

Canuto, R A; Muzio, G; Bonelli, G; Maggiora, M; Autelli, R; Barbiero, G; Costelli, P; Brossa, O; Baccino, F M

1998-01-01

In the AH-130 hepatoma, a poorly differentiated tumor, maintained by weekly transplantations in rats, a low percentage of cells spontaneously underwent apoptosis, mainly during the transition from logarithmic- to stationary-growth phase. It was possible to induce massive apoptosis of cells by treating them with clofibrate, a peroxisome proliferator and hypolipidemic drug. Similar results were obtained with HepG2 cells. With 1 mM clofibrate, apoptosis began to manifest itself after 1 h of treatment in vitro, and was assessed by morphological analysis, by DNA fragmentation carried out with agarose gel electrophoresis, and with flow cytometric determination of terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling. The mechanisms whereby clofibrate induces apoptosis are still unclear. Since the peroxisome proliferator-activated receptor was expressed at a very low level and was not stimulated by clofibrate in the AH-130 hepatoma cells, its involvement seems unlikely. Moreover, lipid peroxidation was not increased after clofibrate treatment. Phospholipids and cholesterol were significantly decreased. The decreased cholesterol content might suggest an inhibition of the mevalonate pathway and, therefore, of isoprenylation of proteins involved in cell proliferation.

Radioiodide induces apoptosis in human thyroid tissue in culture.

PubMed

Russo, Eleonora; Guerra, Anna; Marotta, Vincenzo; Faggiano, Antongiulio; Colao, Annamaria; Del Vecchio, Silvana; Tonacchera, Massimo; Vitale, Mario

2013-12-01

Radioiodide ((131)I) is routinely used for the treatment of toxic adenoma, Graves' disease, and for ablation of thyroid remnant after thyroidectomy in patients with thyroid cancer. The toxic effects of ionizing radiations on living cells can be mediated by a necrotic and/or apoptotic process. The involvement of apoptosis in radiation-induced cell death in the thyrocytes has been questioned. The knowledge of the mechanisms that underlie the thyrocyte death in response to radiations can help to achieve a successful treatment with the lowest (131)I dose. We developed a method to study the effects of (131)I in human thyroid tissue in culture, by which we demonstrated that (131)I induces thyroid cell apoptosis. Human thyroid tissues of about 1 mm(3) were cultured in vitro and cell viability was determined up to 3 weeks by the MTT assay. Radioiodide added to the culture medium was actively taken up by the tissues. The occurrence of apoptosis in the thyrocytes was assessed by measuring the production of a caspase-cleavage fragment of cytokeratin 18 (M30) by an enzyme-linked immunoassay. Neither variation of cell number nor spontaneous apoptosis was revealed after 1 week of culture. (131)I added to the culture medium induced a dose-dependent and a time-dependent generation of M30 fragment. The apoptotic process was confirmed by the generation of caspase-3 and PARP cleavage products. These results demonstrate that (131)I induces apoptosis in human thyrocytes. Human thyroid tissue cultures may be useful to investigate the cell death pathways induced by (131)I.

Caspase-12 is involved in stretch-induced apoptosis mediated endoplasmic reticulum stress.

PubMed

Zhang, Qiang; Liu, Jianing; Chen, Shulan; Liu, Jing; Liu, Lijuan; Liu, Guirong; Wang, Fang; Jiang, Wenxin; Zhang, Caixia; Wang, Shuangyu; Yuan, Xiao

2016-04-01

It is well recognized that mandibular growth, which is caused by a variety of functional appliances, is considered to be the result of both neuromuscular and skeletal adaptations. Accumulating evidence has demonstrated that apoptosis plays an important role in the adaptation of skeletal muscle function. However, the underlying mechanism of apoptosis that is induced by stretch continues to be incompletely understood. Endoplasmic reticulum stress (ERS), a newly defined signaling pathway, initiates apoptosis. This study seeks to determine if caspase-12 is involved in stretch-induced apoptosis mediated endoplasmic reticulum stress in myoblast and its underlying mechanism. Apoptosis was assessed by Hochest staining, DAPI staining and annexin V binding and PI staining. ER chaperones, such as GRP78, CHOP and caspase-12, were determined by reverse transcription polymerase chain reaction (RT-PCR) and Western blot. Furthermore, caspase-12 inhibitor was used to value the mechanism of the caspase-12 pathway. Apoptosis of myoblast, which is subjected to cyclic stretch, was observed in a time-dependent manner. We found that GRP78 mRNA and protein were significantly increased and CHOP and caspase-12 were activated in myoblast that was exposed to cyclic stretch. Caspase-12 inhibition reduced stretch-induced apoptosis, and caspase-12 activated caspase-3 to induce apoptosis. We concluded that caspase-12 played an important role in stretch-induced apoptosis that is associated by endoplasmic reticulum stress by activating caspase-3.

Auranofin induces apoptosis and necrosis in HeLa cells via oxidative stress and glutathione depletion.

PubMed

You, Bo Ra; Shin, Hye Rim; Han, Bo Ram; Kim, Suhn Hee; Park, Woo Hyun

2015-02-01

Auranofin (Au), an inhibitor of thioredoxin reductase, is a known anti‑cancer drug. In the present study, the anti‑growth effect of Au on HeLa cervical cancer cells was examined in association with levels of reactive oxygen species (ROS) and glutathione (GSH). Au inhibited the growth of HeLa cells with an IC50 of ~2 µM at 24 h. This agent induced apoptosis and necrosis, accompanied by the cleavage of poly (ADP‑ribose) polymerase and loss of mitochondrial membrane potential. The pan‑caspase inhibitor, benzyloxycarbonyl‑Val‑Ala‑Asp‑fluoromethylketone, prevented apoptotic cell death and each of the assessed caspase inhibitors inhibited necrotic cell death induced by Au. With respect to the levels of ROS and GSH, Au increased intracellular O2•- in the HeLa cells and induced GSH depletion. The pan‑caspase inhibitor reduced the levels of O2•- and GSH depletion in Au‑treated HeLa cells. The antioxidant, N‑acetyl cysteine, not only attenuated apoptosis and necrosis in the Au‑treated HeLa cells, but also decreased the levels of O2•- and GSH depletion in the cells. By contrast, L‑buthionine sulfoximine, a GSH synthesis inhibitor, intensified cell death O2•- and GSH depletion in the Au‑treated HeLa cells. In conclusion, Au induced apoptosis and necrosis in HeLa cells via the induction of oxidative stress and the depletion of GSH.

APCCdc20 Suppresses Apoptosis through Targeting Bim for Ubiquitination and Destruction

PubMed Central

Wan, Lixin; Tan, Mingjia; Yang, Jie; Inuzuka, Hiroyuki; Dai, Xiangpeng; Wu, Tao; Liu, Jia; Shaik, Shavali; Chen, Guoan; Deng, Jing; Malumbres, Marcos; Letai, Anthony; Kirschner, Marc W.; Sun, Yi; Wei, Wenyi

2014-01-01

SUMMARY APCCdc20 plays pivotal roles in governing mitotic progression. By suppressing APCCdc20, anti-mitotic agents activate the spindle-assembly-checkpoint (SAC), and induce apoptosis after prolonged-treatment, while depletion of endogenous Cdc20 suppresses in vivo tumorigenesis in part by triggering mitotic arrest and subsequent apoptosis. However, the molecular mechanism(s) underlying apoptosis induced by Cdc20 abrogation remains poorly understood. Here we report that the BH3-only pro-apoptotic protein Bim is an APCCdc20 target, as such depletion of Cdc20 sensitizes cells to apoptotic stimuli. Strikingly, Cdc20 and multiple APC-core components were identified in an siRNA screen that upon knockdown sensitizes otherwise resistant cancer cells to chemo-radiation therapies in a Bim-dependent manner. Consistently, human Adult-T-cell-Leukemia (ATL) cells that acquire elevated APCCdc20 activity via expressing the Tax-viral-oncoprotein, exhibit reduced Bim levels and resistance to anti-cancer agents. These results reveal an important role for APCCdc20 in governing apoptosis, strengthening the rationale for developing specific Cdc20 inhibitors as effective anti-cancer agents. PMID:24871945

Dihydroartemisinin induces apoptosis preferentially via a Bim-mediated intrinsic pathway in hepatocarcinoma cells.

PubMed

Qin, Guiqi; Zhao, ChuBiao; Zhang, Lili; Liu, Hongyu; Quan, Yingyao; Chai, Liuying; Wu, Shengnan; Wang, Xiaoping; Chen, Tongsheng

2015-08-01

This report is designed to dissect the detail molecular mechanism by which dihydroartemisinin (DHA), a derivative of artemisinin, induces apoptosis in human hepatocellular carcinoma (HCC) cells. DHA induced a loss of the mitochondrial transmemberane potential (ΔΨm), release of cytochrome c, activation of caspases, and externalization of phosphatidylserine indicative of apoptosis induction. Compared with the modest inhibitory effects of silencing Bax, silencing Bak largely prevented DHA-induced ΔΨm collapse and apoptosis though DHA induced a commensurable activation of Bax and Bak, demonstrating a key role of the Bak-mediated intrinsic apoptosis pathway. DHA did not induce Bid cleavage and translocation from cytoplasm to mitochondria and had little effects on the expressions of Puma and Noxa, but did increase Bim and Bak expressions and decrease Mcl-1 expression. Furthermore, the cytotoxicity of DHA was remarkably reduced by silencing Bim, and modestly but significantly reduced by silencing Puma or Noxa. Silencing Bim or Noxa preferentially reduced DHA-induced Bak activation, while silencing Puma preferentially reduced DHA-induced Bax activation, demonstrating that Bim and to a lesser extent Noxa act as upstream mediators to trigger the Bak-mediated intrinsic apoptosis pathway. In addition, silencing Mcl-1 enhanced DHA-induced Bak activation and apoptosis. Taken together, our data demonstrate a crucial role of Bim in preferentially regulating the Bak/Mcl-1 rheostat to mediate DHA-induced apoptosis in HCC cells.

The Transcription Factor Wilms Tumor 1 Confers Resistance in Myeloid Leukemia Cells against the Proapoptotic Therapeutic Agent TRAIL (Tumor Necrosis Factor α-related Apoptosis-inducing Ligand) by Regulating the Antiapoptotic Protein Bcl-xL*

PubMed Central

Bansal, Hima; Seifert, Theresea; Bachier, Carlos; Rao, Manjeet; Tomlinson, Gail; Iyer, Swaminathan Padmanabhan; Bansal, Sanjay

2012-01-01

Tumor necrosis factor α-related apoptosis-inducing ligand (TRAIL) is considered a promising cancer therapeutic agent due to its ability to induce apoptosis in a variety of cancer cells, while sparing normal cells. However, many human tumors including acute myeloid leukemia (AML) are partially or completely resistant to monotherapy with TRAIL, limiting its therapeutic utility. Therefore, identification of factors that contribute to TRAIL resistance may facilitate future development of more effective TRAIL-based cancer therapies. Here, we report a previously unknown role for WT1 in mediating TRAIL resistance in leukemia. Knockdown of WT1 with shRNA rendered TRAIL-resistant myeloid leukemia cells sensitive to TRAIL-induced cell death, and re-expression of shRNA-resistant WT1 restored TRAIL resistance. Notably, TRAIL-mediated apoptosis in WT1-silenced cells was largely due to down-regulation of the antiapoptotic protein Bcl-xL. Moreover, WT1 expression strongly correlated with overexpression of Bcl-xL in AML cell lines and blasts from AML patients. Furthermore, we found that WT1 transactivates Bcl-xL by directly binding to its promoter. We previously showed that WT1 is a novel client protein of heat shock protein 90 (Hsp90). Consistent with this, pharmacological inhibition of Hsp90 resulted in reduced WT1 and Bcl-xL expression leading to increased sensitivity of leukemia cells to TRAIL-mediated apoptosis. Collectively, our results suggest that WT1-dependent Bcl-xL overexpression contributes to TRAIL resistance in myeloid leukemias. PMID:22898820

Parvovirus B19-Induced Apoptosis of Hepatocytes

PubMed Central

Poole, Brian D.; Karetnyi, Yuory V.; Naides, Stanley J.

2004-01-01

Parvovirus B19 (B19 virus) can persist in multiple tissues and has been implicated in a variety of diseases, including acute fulminant liver failure. The mechanism by which B19 virus induces liver failure remains unknown. Hepatocytes are nonpermissive for B19 virus replication. We previously reported that acute fulminant liver failure associated with B19 virus infection was characterized by hepatocellular dropout. We inoculated both primary hepatocytes and the hepatocellular carcinoma cell line Hep G2 with B19 virus and assayed for apoptosis by using annexin V staining. Reverse transcriptase PCR analysis and immunofluorescence demonstrated that B19 virus was able to infect the cells and produce its nonstructural protein but little or no structural capsid protein. Infection with B19 virus induced means of 28% of Hep G2 cells and 10% of primary hepatocytes to undergo apoptosis, which were four- and threefold increases, respectively, over background levels. Analysis of caspase involvement showed that B19 virus-inoculated cultures had a significant increase in the number of cells with active caspase 3. Inhibition studies demonstrated that caspases 3 and 9, but not caspase 8, are required for B19 virus-induced apoptosis. PMID:15220451

Nicotinamide induces mitochondrial-mediated apoptosis through oxidative stress in human cervical cancer HeLa cells.

PubMed

Feng, Yi; Wang, Yonghua; Jiang, Chengrui; Fang, Zishui; Zhang, Zhiqiang; Lin, Xiaoying; Sun, Liwei; Jiang, Weiying

2017-07-15

Nicotinamide participates in energy metabolism and influences cellular redox status and modulates multiple pathways related with both cellular survival and death. Recent studies have shown that it induced proliferation inhibition and apoptosis in many cancer cells. However, little is known about the effects of nicotinamide on human cervical cancer cells. We aimed to evaluate the effects of the indicated concentrations nicotinamide on cell proliferation, apoptosis and redox-related parameters in HeLa cells and investigated the apoptotic mechanism. After the treatment of the indicated concentrations nicotinamide, HeLa cell proliferation was evaluated by the CCK-8 assay and the production of ROS (reactive oxygen species) was measured using 2',7'-Dichlorofluorescin diacetate. The apoptotic effect was confirmed by observing the cellular and nuclear morphologies with fluorescence microscope and apoptotic rate of HeLa cell apoptosis was measured by flow cytometry using Annexin-V method. Moreover, we examined the mitochondrial membrane potential by JC-1 method and measured the expression of apoptosis related genes using qRT-PCR and immunoblotting. Nicotinamide restrained the HeLa cell proliferation and significantly increased the accumulation of ROS and depletion of GSH at relatively high concentrations. Furthermore, nicotinamide promoted HeLa cell apoptosis via the intrinsic mitochondrial apoptotic pathway. Our study revealed that nicotinamide induced the apoptosis through oxidative stress and intrinsic mitochondrial apoptotic pathways in HeLa cell. The results emerge that nicotinamide may be an inexpensive, safe and promising therapeutic agent or a neoadjuvant chemotherapy for cervical cancer patients, as well useful to find new drugs for cervical cancer therapy. Copyright © 2017 Elsevier Inc. All rights reserved.

Osteoblasts Protect AML Cells from SDF-1-Induced Apoptosis

PubMed Central

Kremer, Kimberly N.; Dudakovic, Amel; McGee-Lawrence, Meghan E.; Philips, Rachael L.; Hess, Allan D.; Smith, B. Douglas; van Wijnen, Andre J.; Karp, Judith E.; Kaufmann, Scott H.; Westendorf, Jennifer J.; Hedin, Karen E.

2014-01-01

The bone marrow provides a protective environment for acute myeloid leukemia (AML) cells that often allows leukemic stem cells to survive standard chemotherapeutic regimens. Targeting these leukemic stem cells within the bone marrow is critical for preventing relapse. We recently demonstrated that SDF-1, a chemokine abundant in the bone marrow, induces apoptosis in AML cell lines and in patient samples expressing high levels of its receptor, CXCR4. Here we show that a subset of osteoblast lineage cells within the bone marrow can protect AML cells from undergoing apoptosis in response to the SDF-1 naturally present in that location. In co-culture systems, osteoblasts at various stages of differentiation protected AML cell lines and patient isolates from SDF-1-induced apoptosis. The differentiation of the osteoblast cell lines, MC3T3 and W-20-17, mediated this protection via a cell contact-independent mechanism. In contrast, bone marrow-derived mesenchymal cells, the precursors of osteoblasts, induced apoptosis in AML cells via a CXCR4-dependent mechanism and failed to protect AML cells from exogenously added SDF-1. These results indicate that osteoblasts in the process of differentiation potently inhibit the SDF-1-driven apoptotic pathway of CXCR4-expressing AML cells residing in the bone marrow. Drugs targeting this protective mechanism could potentially provide a new approach to treating AML by enhancing the SDF-1-induced apoptosis of AML cells residing within the bone marrow microenvironment. PMID:24851270

Quercetin Induces Apoptosis of Trypanosoma brucei gambiense and Decreases the Proinflammatory Response of Human Macrophages

PubMed Central

Mamani-Matsuda, Maria; Rambert, Jérôme; Malvy, Denis; Lejoly-Boisseau, Hélène; Daulouède, Sylvie; Thiolat, Denis; Coves, Sara; Courtois, Pierrette; Vincendeau, Philippe; Djavad Mossalayi, M.

2004-01-01

In addition to parasite spread, the severity of disease observed in cases of human African trypanosomiasis (HAT), or sleeping sickness, is associated with increased levels of inflammatory mediators, including tumor necrosis factor (TNF)-α and nitric oxide derivatives. In the present study, quercetin (3,3′,4′,5,7-pentahydroxyflavone), a potent immunomodulating flavonoid, was shown to directly induce the death of Trypanosoma brucei gambiense, the causative agent of HAT, without affecting normal human cell viability. Quercetin directly promoted T. b. gambiense death by apoptosis as shown by Annexin V binding. In addition to microbicidal activity, quercetin induced dose-dependent decreases in the levels of TNF-α and nitric oxide produced by activated human macrophages. These results highlight the potential use of quercetin as an antimicrobial and anti-inflammatory agent for the treatment of African trypanomiasis. PMID:14982785

Cigarette Smoke–Induced CXCR3 Receptor Up-Regulation Mediates Endothelial Apoptosis

PubMed Central

Green, Linden A.; Petrusca, Daniela; Rajashekhar, Gangaraju; Gianaris, Tom; Schweitzer, Kelly S.; Wang, Liang; Justice, Matthew J.; Petrache, Irina

2012-01-01

Endothelial monocyte–activating polypeptide II (EMAP II) and interferon-inducible protein (IP)–10 are proinflammatory mediators, which in addition to their chemokine activities, selectively induce apoptosis in endothelial cells and are up-regulated in the lungs of cigarette smoke–exposed humans. Previously, we showed that EMAP II is an essential mediator of cigarette smoke–induced lung emphysema in mice linking endothelial cell apoptosis with inflammation. Here we addressed the role of the CXCR3 receptor in EMAP II–induced and IP-10–induced apoptosis in endothelial cells and its regulation by cigarette smoke. We found that both neutralizing antibodies and small inhibitory RNA to CXCR3 abrogated EMAP II–induced and IP-10–induced endothelial caspase-3 activation and DNA fragmentation. CXCR3 receptor surface expression in human lung microvascular endothelial cells and in lung tissue endothelium was up-regulated by exposure to cigarette smoke. In tissue culture conditions, EMAP II–induced and IP-10–induced apoptosis was enhanced by preincubation with cigarette smoke extract. Interestingly, serum starvation also induced CXCR3 up-regulation and enhanced EMAP II–induced endothelial apoptosis. Signal transduction via p38 mitogen-activated protein kinase activation was essential for CXCR3-induced cell death, but not for CXCR3 receptor up-regulation by cigarette smoke. In turn, protein nitration was required for CXCR3 receptor up-regulation by cigarette smoke and consequently for subsequent CXCR3-induced cell death. In conclusion, the concerted up-regulation of proinflammatory EMAP II, IP-10, and CXCR3 by cigarette smoke could sustain a cascade of cell death that may promote the alveolar tissue loss noted in human emphysema. PMID:22936405

Tryptophol induces death receptor (DR) 5-mediated apoptosis in U937 cells.

PubMed

Inagaki, Shyuichiro; Morimura, Shigeru; Tang, Yueqin; Akutagawa, Hiroshi; Kida, Kenji

2007-08-01

Tryptophol is a natural component isolated from vinegar produced from the boiled extract of black soybean. We have reported that tryptophol induces apoptosis in U937 cells via activation of caspase-8 followed by caspase-3. Tryptophol, however, did not affect human peripheral blood lymphocytes (PBL). In this study, we found that tryptophol enhances formation of a death-inducing signaling complex including death receptor (DR) 5. Cell viability and induction of apoptosis by tryptophol was reduced by transfection with decoy receptor (DcR) 1. These results indicate that tryptophol induces apoptosis through DR5 and that the resistance of PBL to tryptophol-induced apoptosis might be due to competition from DcR1.

GGPPS deficiency aggravates CCl4-induced liver injury by inducing hepatocyte apoptosis.

PubMed

Chen, Wei-Bo; Lai, Shan-Shan; Yu, De-Cai; Liu, Jia; Jiang, Shan; Zhao, Dan-Dan; Ding, Yi-Tao; Li, Chao-Jun; Xue, Bin

2015-04-28

GGPPS catalyses the expression of GGPP, a key protein in the mevalonate metabolic pathway. HMG-CoA reductase inhibitor statins can induce liver injury by inhibiting GGPP. However, the function of GGPPS in liver injury has not yet been revealed. In this study, we found that GGPPS increased in liver injury and that GGPPS deletion augmented liver injury and fibrosis. GGPPS inhibition induced hepatocyte apoptosis, inflammation and TGF-β1 secretion, which activated hepatic stellate cells. Our findings imply that GGPPS deletion induces hepatocyte apoptosis, which makes the liver vulnerable to hepatotoxicity. Copyright © 2015 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

JS-K promotes apoptosis by inducing ROS production in human prostate cancer cells.

PubMed

Qiu, Mingning; Chen, Lieqian; Tan, Guobin; Ke, Longzhi; Zhang, Sai; Chen, Hege; Liu, Jianjun

2017-03-01

Reactive oxygen species (ROS) are chemical species that alter redox status, and are responsible for inducing carcinogenesis. The purpose of the present study was to assess the effects of the glutathione S transferase-activated nitric oxide donor prodrug, JS-K, on ROS accumulation and on proliferation and apoptosis in human prostate cancer cells. Cell proliferation and apoptosis, ROS accumulation and the activation of the mitochondrial signaling pathway were measured. The results demonstrated that JS-K may inhibit prostate cancer cell growth in a dose- and time-dependent manner, and induce ROS accumulation and apoptosis in a dose-dependent manner. With increasing concentrations of JS-K, expression of pro-apoptotic proteins increased, but Bcl-2 expression decreased. Additionally, the antioxidant N-acetylcysteine reversed JS-K-induced cell apoptosis; conversely, the pro-oxidant glutathione disulfide exacerbated JS-K-induced apoptosis. In conclusion, the data suggest that JS-K induces prostate cancer cell apoptosis by increasing ROS levels.

JS-K promotes apoptosis by inducing ROS production in human prostate cancer cells

PubMed Central

Qiu, Mingning; Chen, Lieqian; Tan, Guobin; Ke, Longzhi; Zhang, Sai; Chen, Hege; Liu, Jianjun

2017-01-01

Reactive oxygen species (ROS) are chemical species that alter redox status, and are responsible for inducing carcinogenesis. The purpose of the present study was to assess the effects of the glutathione S transferase-activated nitric oxide donor prodrug, JS-K, on ROS accumulation and on proliferation and apoptosis in human prostate cancer cells. Cell proliferation and apoptosis, ROS accumulation and the activation of the mitochondrial signaling pathway were measured. The results demonstrated that JS-K may inhibit prostate cancer cell growth in a dose- and time-dependent manner, and induce ROS accumulation and apoptosis in a dose-dependent manner. With increasing concentrations of JS-K, expression of pro-apoptotic proteins increased, but Bcl-2 expression decreased. Additionally, the antioxidant N-acetylcysteine reversed JS-K-induced cell apoptosis; conversely, the pro-oxidant glutathione disulfide exacerbated JS-K-induced apoptosis. In conclusion, the data suggest that JS-K induces prostate cancer cell apoptosis by increasing ROS levels. PMID:28454225

Ceramide-Induced Apoptosis in Renal Tubular Cells: A Role of Mitochondria and Sphingosine-1-Phoshate

PubMed Central

Ueda, Norishi

2015-01-01

Ceramide is synthesized upon stimuli, and induces apoptosis in renal tubular cells (RTCs). Sphingosine-1 phosphate (S1P) functions as a survival factor. Thus, the balance of ceramide/S1P determines ceramide-induced apoptosis. Mitochondria play a key role for ceramide-induced apoptosis by altered mitochondrial outer membrane permeability (MOMP). Ceramide enhances oligomerization of pro-apoptotic Bcl-2 family proteins, ceramide channel, and reduces anti-apoptotic Bcl-2 proteins in the MOM. This process alters MOMP, resulting in generation of reactive oxygen species (ROS), cytochrome C release into the cytosol, caspase activation, and apoptosis. Ceramide regulates apoptosis through mitogen-activated protein kinases (MAPKs)-dependent and -independent pathways. Conversely, MAPKs alter ceramide generation by regulating the enzymes involving ceramide metabolism, affecting ceramide-induced apoptosis. Crosstalk between Bcl-2 family proteins, ROS, and many signaling pathways regulates ceramide-induced apoptosis. Growth factors rescue ceramide-induced apoptosis by regulating the enzymes involving ceramide metabolism, S1P, and signaling pathways including MAPKs. This article reviews evidence supporting a role of ceramide for apoptosis and discusses a role of mitochondria, including MOMP, Bcl-2 family proteins, ROS, and signaling pathways, and crosstalk between these factors in the regulation of ceramide-induced apoptosis of RTCs. A balancing role between ceramide and S1P and the strategy for preventing ceramide-induced apoptosis by growth factors are also discussed. PMID:25751724

γ-Tocotrienol Inhibits Proliferation and Induces Apoptosis Via the Mitochondrial Pathway in Human Cervical Cancer HeLa Cells.

PubMed

Xu, Weili; Mi, Yaqing; He, Pan; He, Shenghua; Niu, Lingling

2017-08-04

γ-Tocotrienol, a kind of isoprenoid phytochemical, has antitumor activity. However, there is limited evidence that it has an effect on cervical cancer. In this study, the capacity to inhibit proliferation and induce apoptosis in human cervical cancer HeLa cells and the mechanism underlying these effects were examined. The results indicated that a γ-tocotrienol concentration over 30 μM inhibited the growth of HeLa cells with a 50% inhibitory concentration (IC 50 ) of 46.90 ± 3.50 μM at 24 h, and significantly down-regulated the expression of proliferative cell nuclear antigen (PCNA) and Ki-67. DNA flow cytometric analysis indicated that γ-tocotrienol arrested the cell cycle at G0/G1 phase and reduced the S phase in HeLa cells. γ-tocotrienol induced apoptosis of HeLa cells in a time- and dose-dependent manner. γ-tocotrienol-induced apoptosis in HeLa cells was accompanied by down-regulation of Bcl-2, up-regulation of Bax, release of cytochrome from mitochondria, activation of caspase-9 and caspase-3, and subsequent poly (ADP-ribose) polymerase (PARP) cleavage. These results suggested that γ-tocotrienol could significantly inhibit cell proliferation through G0/G1 cell cycle arrest, and induce apoptosis via the mitochondrial apoptotic pathway in human cervical cancer HeLa cells. Thus, our findings revealed that γ-tocotrienol may be considered as a potential agent for cervical cancer therapy.

Goniothalamin prevents the development of chemically induced and spontaneous colitis in rodents and induces apoptosis in the HT-29 human colon tumor cell line

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vendramini-Costa, Débora Barbosa, E-mail: vendrami

Colon cancer is the third most incident type of cancer worldwide. One of the most important risk factors for colon cancer development are inflammatory bowel diseases (IBD), thus therapies focusing on IBD treatment have great potential to be used in cancer prevention. Nature has been a source of new therapeutic and preventive agents and the racemic form of the styryl-lactone goniothalamin (GTN) has been shown to be a promising antiproliferative agent, with gastroprotective, antinociceptive and anti-inflammatory effects. As inflammation is a well-known tumor promoter, the major goal of this study was to evaluate the therapeutic and preventive potentials of GTNmore » on chemically induced and spontaneous colitis, as well as the cytotoxic effects of GTN on a human colon tumor cell line (HT-29). GTN treatments inhibited TNBS-induced acute and chronic colitis development in Wistar rats, reducing myeloperoxidase levels and inflammatory cells infiltration in the mucosa. In spontaneous-colitis using IL-10 deficient mice (C57BL/6 background), GTN prevented colitis development through downregulation of TNF-α, upregulation of SIRT-1 and inhibition of proliferation (PCNA index), without signs of toxicity after three months of treatment. In HT-29 cells, treatment with 10 μM of GTN induced apoptosis by increasing BAX/BCL2, p-JNK1/JNK1, p-P38/P38 ratios as well as through ROS generation. Caspase 8, 9 and 3 activation also occurred, suggesting caspase-dependent apoptotic pathway, culminating in PARP-1 cleavage. Together with previous data, these results show the importance of GTN as a pro-apoptotic, preventive and therapeutic agent for IBD and highlight its potential as a chemopreventive agent for colon cancer. - Highlights: • Goniothalamin (GTN) inhibits the development of TNBS-induced colitis in rats. • Moreover, GTN prevents the development of spontaneous colitis in IL-10 deficient mice. • This activity relies on downregulation of TNF-α and upregulation of SIRT-1

Oxymatrine induces apoptosis in human cervical cancer cells through guanine nucleotide depletion.

PubMed

Li, Mu; Su, Bao-Shan; Chang, Li-Hua; Gao, Qing; Chen, Kun-Lun; An, Peng; Huang, Chen; Yang, Jun; Li, Zong-Fang

2014-02-01

Oxymatrine is an alkaloid obtained primarily from Sophora roots and has been shown to show anticancer effects in various cancers. However, the cellular and molecular effects of this agent on cervical cancer have been poorly characterized. Here, we investigated the antitumor effect of oxymatrine on a human cervical cancer cell line (HeLa). Our results showed that application of oxymatrine significantly inhibited the cell growth and tumorigenesis in a dose-dependent manner and induced apoptosis through caspase-dependent pathways as determined using flow cytometry and TUNEL staining analysis. To define the proteins potentially related to the mechanisms of action, proteomic analysis was utilized to detect proteins altered by oxymatrine. As the downregulated gene, inosine monophosphate dehydrogenase type II (IMPDH2) was responsible for oxymatrine-induced mitochondrial-related apoptosis. Moreover, oxymatrine depleted intracellular guanosine 5'-triphosphate (GTP) levels by effective IMPDH inhibition. Functional analyses further showed that oxymatrine and tiazofurin, an inhibitor of IMPDH2, sensitized resistant HeLa/DDP cells to cisplatin. In addition, the expression of IMPDH2 in cervical cancer was significantly higher than that in the normal cervical epithelium. Taken together, these findings suggest that targeting of IMPDH2 by potential pharmacological inhibitors, oxymatrine in combination with chemotherapy, might be a promising means of overcoming chemoresistance in cervical cancer with high IMPDH2 expression, and may thus provide new insights into the mechanism of oxyamtrine-induced anticancer effects.

Licochalcone A induces apoptosis in KB human oral cancer cells via a caspase-dependent FasL signaling pathway

PubMed Central

KIM, JAE-SUNG; PARK, MI-RA; LEE, SOOK-YOUNG; KIM, DO KYOUNG; MOON, SUNG-MIN; KIM, CHUN SUNG; CHO, SEUNG SIK; YOON, GOO; IM, HEE-JEONG; YOU, JAE-SEEK; OH, JI-SU; KIM, SU-GWAN

2014-01-01

Licochalcone A (Lico-A) is a natural phenol licorice compound with multiple bioactivities, including anti-inflammatory, anti-microbial, anti-fungal and osteogenesis-inducing properties. In the present study, we investigated the Lico-A-induced apoptotic effects and examined the associated apoptosis pathway in KB human oral cancer cells. Lico-A decreased the number of viable KB oral cancer cells. However, Lico-A did not have an effect on primary normal human oral keratinocytes. In addition, the IC50 value of Lico-A was determined to be ~50 μM following dose-dependent stimulation. KB oral cancer cells stimulated with Lico-A for 24 h showed chromatin condensation by DAPI staining, genomic DNA fragmentation by agarose gel electrophoresis and a gradually increased apoptotic cell population by FACS analysis. These data suggest that Lico-A induces apoptosis in KB oral cancer cells. Additionally, Lico-A-induced apoptosis in KB oral cancer cells was mediated by the expression of factor associated suicide ligand (FasL) and activated caspase-8 and −3 and poly(ADP-ribose) polymerase (PARP). Furthermore, in the KB oral cancer cells co-stimulation with a caspase inhibitor (Z-VAD-fmk) and Lico-A significantly abolished the apoptotic phenomena. Our findings demonstrated that Lico-A-induced apoptosis in KB oral cancer cells involves the extrinsic apoptotic signaling pathway, which involves a caspase-dependent FasL-mediated death receptor pathway. Our data suggest that Lico-A be developed as a chemotherapeutic agent for the management of oral cancer. PMID:24337492

Noxa/Mcl-1 Balance Regulates Susceptibility of Cells to Camptothecin-Induced Apoptosis1

PubMed Central

Mei, Yide; Xie, Chongwei; Xie, Wei; Tian, Xu; Li, Mei; Wu, Mian

2007-01-01

Although camptothecin (CPT) has been reported to induce apoptosis in various cancer cells, the molecular details of this regulation remain largely unknown. In this study, we demonstrate that BH3-only protein Noxa is upregulated during CPT-induced apoptosis, which is independent of p53. In addition, we show that phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway is responsible for Noxa's induction. Luciferase assay and cAMP response element binding protein (CREB) knockdown experiments further demonstrate that CREB is involved in the transcriptional upregulation of Noxa. Moreover, blocking Noxa expression using specific small interfering ribonucleic acid (siRNA) significantly reduces the apoptosis in response to CPT, indicating that Noxa is an essential mediator for CPT-induced apoptosis. Interestingly, antiapoptotic Mcl-1 was also upregulated through PI3K/Akt signaling pathway upon CPT treatment. Using immunoprecipitation assay, Noxa was found to interact with Mcl-1 in the presence or absence of CPT. Knockdown of Mcl-1 expression by short hairpin ribonucleic acid (shRNA) was shown to potentiate CPT-induced apoptosis. Consistently, ectopic overexpression of Mcl-1 rescued cells from apoptosis induced by CPT. Cells coexpressing Noxa and Mcl-1 at different ratio correlates well with the extent of apoptosis, suggesting that the balance between Noxa and Mcl-1 may determine the susceptibility of HeLa cells to CPT-induced apoptosis. PMID:17971907

O-GlcNAcylation regulates ischemia-induced neuronal apoptosis through AKT signaling.

PubMed

Shi, Jianhua; Gu, Jin-hua; Dai, Chun-ling; Gu, Jianlan; Jin, Xiaoxia; Sun, Jianming; Iqbal, Khalid; Liu, Fei; Gong, Cheng-Xin

2015-09-28

Apoptosis plays an important role in neural development and neurological disorders. In this study, we found that O-GlcNAcylation, a unique protein posttranslational modification with O-linked β-N-acetylglucosamine (GlcNAc), promoted apoptosis through attenuating phosphorylation/activation of AKT and Bad. By using co-immunoprecipitation and mutagenesis techniques, we identified O-GlcNAc modification at both Thr308 and Ser473 of AKT. O-GlcNAcylation-induced apoptosis was attenuated by over-expression of AKT. We also found a dynamic elevation of protein O-GlcNAcylation during the first four hours of cerebral ischemia, followed by continuous decline after middle cerebral artery occlusion (MCAO) in the mouse brain. The elevation of O-GlcNAcylation coincided with activation of cell apoptosis. Finally, we found a negative correlation between AKT phosphorylation and O-GlcNAcylation in ischemic brain tissue. These results indicate that cerebral ischemia induces a rapid increase of O-GlcNAcylation that promotes apoptosis through down-regulation of AKT activity. These findings provide a novel mechanism through which O-GlcNAcylation regulates ischemia-induced neuronal apoptosis through AKT signaling.

c-Myc-induced apoptosis in fibroblasts is inhibited by specific cytokines.

PubMed Central

Harrington, E A; Bennett, M R; Fanidi, A; Evan, G I

1994-01-01

We have investigated the mechanism by which deregulated expression of c-Myc induces death by apoptosis in serum-deprived fibroblasts. We demonstrate that Myc-induced apoptosis in low serum is inhibited by a restricted group of cytokines, principally the insulin-like growth factors and PDGF. Cytokine-mediated protection from apoptosis is not linked to the cytokines' abilities to promote growth. Protection from apoptosis is evident in the post-commitment (mitogen-independent) S/G2/M phases of the cell cycle and also in cells that are profoundly blocked in cell cycle progression by drugs. Moreover, IGF-I inhibition of apoptosis occurs in the absence of protein synthesis, and so does not require immediate early gene expression. We conclude that c-Myc-induced apoptosis does not result from a conflict of growth signals but appears to be a normal physiological aspect of c-Myc function whose execution is regulated by the availability of survival factors. We discuss the possible implications of these findings for models of mammalian cell growth in vivo. Images PMID:8045259

Influence of silencing soluble epoxide hydrolase with RNA interference on cardiomyocytes apoptosis induced by doxorubicin.

PubMed

Du, Guangsheng; Lv, Jiagao; He, Li; Ma, Yexin

2011-06-01

In order to investigate the influence of silencing soluble epoxide hydrolase (sEH) with double-stranded small interfering RNA (siRNA) on cardiomyocytes apoptosis induced by doxorubicin (DOX), two plasmids containing siRNA sequences specific to sEH were constructed and transfected into the primary cultured cardiomyocytes by using FuGENE HD transfection agents. The mRNA and protein expression levels of sEH were detected by semiquantitative RT-PCR and Western blotting respectively, and the plasmids that silenced sEH most significantly were selected, and renamed EH-R. The plasmids carrying a nonspecific siRNA coding sequence (PCN) served as the negative control. Cardiomyocytes were divided into four groups: control group, DOX group, PCN+DOX group, and EH-R+DOX group. Apoptosis of cardiomyocytes was induced by DOX at a concentration of 1 μmol/L. Apoptosis rate of cardiomyocytes was determined by flow cytometery. The protein expression levels of Bcl-2 and Bax were detected by Western blotting. The results showed that the expression of sEH was down-regulated by EH-R plasmid. The expression levels of sEH mRNA and protein in the EH-R+DOX group were significantly decreased as compared with other groups (P<0.01). As compared with the control group, the apoptosis rate of cardiomyocytes in three DOX-treated groups was obviously increased, the expression levels of Bax increased, and those of Bcl-2 decreased (P<0.01). However, the expression levels of Bax were decreased, those of Bcl-2 increased and the apoptosis rate of cardiomyocytes obviously decreased in EH-R+DOX group when compared with those in the DOX group and the PCN+DOX group (P<0.01 for each). It was concluded that the recombinant plasmids could be successfully constructed, and transfected into the primary cultured cardiomyocytes. They could ameliorate the DOX-induced cardiomyocytes apoptosis by selectively inhibiting the expression of sEH with RNAi and increasing the expression of Bcl-2.

Infrasound exposure induces apoptosis of rat cardiac myocytes by regulating the expression of apoptosis-related proteins.

PubMed

Pei, Zhao-Hui; Chen, Bao-Ying; Tie, Ru; Zhang, Hai-Feng; Zhao, Ge; Qu, Ping; Zhu, Xiao-Xing; Zhu, Miao-Zhang; Yu, Jun

2011-12-01

It has been reported that exposure to infrasound causes cardiac dysfunction. Allowing for the key role of apoptosis in the pathogenesis of cardiovascular diseases, the objective of this study was to investigate the apoptotic effects of infrasound. Cardiac myocytes cultured from neonatal rats were exposed to infrasound of 5 Hz at 130 dB. The apoptosis was determined by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling. Also, the expression levels of a series of apoptosis-related proteins were detected. As a result, infrasound induced apoptosis of cultured rat cardiac myocytes in a time-dependant manner. The expression of proapoptotic proteins such as Bax, caspase-3, caspase-8, caspase-9, and FAS was significantly up-regulated, with concomitant down-regulated expression of antiapoptotic proteins such as Bcl-x, and the inhibitory apoptosis proteins family proteins including XIAP, cIAP-1, and cIAP-2. The expression of poly (ADP-ribose) polymerase and β-catenin, which are the substrate proteins of caspase-3, was significantly decreased. In conclusion, infrasound is an apoptotic inducer of cardiac myocytes.

Knockdown of HIF-1α and IL-8 induced apoptosis of hepatocellular carcinoma triggers apoptosis of vascular endothelial cells.

PubMed

Choi, Sung Hoon; Park, Jun Yong; Kang, Wonseok; Kim, Seung Up; Kim, Do Young; Ahn, Sang Hoon; Ro, Simon Wonsang; Han, Kwang-Hyub

2016-01-01

A local hypoxic microenvironment is one of the most important characteristics of solid tumors. Hypoxia inducible factor-1α (HIF-1α) and Interleukin-8 (IL-8) activate tumor survival from hypoxic-induced apoptosis in each pathway. This study aimed to evaluate whether knockdown of HIF-1α and IL-8 induced apoptosis of the hepatocellular carcinoma (HCC) and endothelial cell lines. HCC cell lines were infected with adenovirus-expressing shRNA for HIF-1α and IL-8 and maintained under hypoxic conditions (1% O2, 24 h). The expression levels of HIF-1α and both apoptotic and growth factors were examined by real-time quantitative PCR and western blot. We also investigated apoptosis by TUNEL assay (FACS and Immunofluorescence) and measured the concentration of cytochrome C. Inhibition of HIF-1α and IL-8 up-regulated the expression of apoptotic factors while downregulating anti-apoptotic factors simultaneously. Knockdown of HIF-1α and IL-8 increased the concentration of cytochrome C and enhanced DNA fragmentation in HCC cell lines. Moreover, culture supernatant collected from the knockdown of HIF-1α and IL-8 in HCC cell lines induced apoptosis in human umbilical vein endothelial cells under hypoxia, and the expression of variable apoptotic ligand increased from HCC cell lines, time-dependently. These data suggest that adenovirus-mediated knockdown of HIF-1α and IL-8 induced apoptosis in HCC cells and triggered apoptosis of vascular endothelial cells.

Mechanisms of methicillin-resistant Staphylococcus aureus pneumonia-induced intestinal epithelial apoptosis

PubMed Central

Perrone, Erin E.; Jung, Enjae; Breed, Elise; Dominguez, Jessica A.; Liang, Zhe; Clark, Andrew T.; Dunne, W. Michael; Burd, Eileen M.; Coopersmith, Craig M.

2012-01-01

Methicillin-resistant Staphylococcus aureus (MRSA) pneumonia-induced sepsis is a common cause of morbidity in the intensive care unit. Although pneumonia is initiated in the lungs, extrapulmonary manifestations occur commonly. In light of the key role the intestine plays in the pathophysiology of sepsis, we sought to determine whether MRSA pneumonia induces intestinal injury. FVB/N mice were subjected to MRSA or sham pneumonia and sacrificed 24 hours later. Septic animals had a marked increase in intestinal epithelial apoptosis by both H&E and active caspase-3 staining. MRSA-induced intestinal apoptosis was associated with an increase in the expression of the pro-apoptotic proteins Bid and Bax and the anti-apoptotic protein Bcl-xL in the mitochondrial pathway. In the receptor-mediated pathway, MRSA pneumonia induced an increase in Fas-ligand but decreased protein levels of Fas, FADD, pFADD, TNF-R1 and TRADD. To assess the functional significance of these changes, MRSA pneumonia was induced in mice with genetic manipulations in proteins in either the mitochondrial or receptor-mediated pathways. Both Bid−/− mice and animals with intestine specific overexpression of Bcl-2 had decreased intestinal apoptosis compared to wild type animals. In contrast, Fas-ligand−/− mice had no alterations in apoptosis. To determine if these findings were organism-specific, similar experiments were performed in mice subjected to Pseudomonas aeruginosa pneumonia. P. aeruginosa induced gut apoptosis, but unlike MRSA, this was associated with increased Bcl-2 and TNF-R1 and decreased Fas. MRSA pneumonia thus induces organism-specific changes in intestinal apoptosis via changes in both the mitochondrial and receptor-mediated pathways although the former may be more functionally significant. PMID:22592747

Mechanisms of methicillin-resistant Staphylococcus aureus pneumonia-induced intestinal epithelial apoptosis.

PubMed

Perrone, Erin E; Jung, Enjae; Breed, Elise; Dominguez, Jessica A; Liang, Zhe; Clark, Andrew T; Dunne, W Michael; Burd, Eileen M; Coopersmith, Craig M

2012-07-01

Methicillin-resistant Staphylococcus aureus (MRSA) pneumonia-induced sepsis is a common cause of morbidity in the intensive care unit. Although pneumonia is initiated in the lungs, extrapulmonary manifestations occur commonly. In light of the key role the intestine plays in the pathophysiology of sepsis, we sought to determine whether MRSA pneumonia induces intestinal injury. FVB/N mice were subjected to MRSA or sham pneumonia and killed 24 h later. Septic animals had a marked increase in intestinal epithelial apoptosis by both hematoxylin-eosin and active caspase 3 staining. Methicillin-resistant S. aureus-induced intestinal apoptosis was associated with an increase in the expression of the proapoptotic proteins Bid and Bax and the antiapoptotic protein Bcl-xL in the mitochondrial pathway. In the receptor-mediated pathway, MRSA pneumonia induced an increase in Fas ligand but decreased protein levels of Fas, FADD, pFADD, TNF-R1, and TRADD. To assess the functional significance of these changes, MRSA pneumonia was induced in mice with genetic manipulations in proteins in either the mitochondrial or receptor-mediated pathways. Both Bid-/- mice and animals with intestine-specific overexpression of Bcl-2 had decreased intestinal apoptosis compared with wild-type animals. In contrast, Fas ligand-/- mice had no alterations in apoptosis. To determine if these findings were organism-specific, similar experiments were performed in mice subjected to Pseudomonas aeruginosa pneumonia. Pseudomonas aeruginosa induced gut apoptosis, but unlike MRSA, this was associated with increased Bcl-2 and TNF-R1 and decreased Fas. Methicillin-resistant S. aureus pneumonia thus induces organism-specific changes in intestinal apoptosis via changes in both the mitochondrial and receptor-mediated pathways, although the former may be more functionally significant.

Alendronate inhalation ameliorates elastase-induced pulmonary emphysema in mice by induction of apoptosis of alveolar macrophages.

PubMed

Ueno, Manabu; Maeno, Toshitaka; Nishimura, Satoshi; Ogata, Fusa; Masubuchi, Hiroaki; Hara, Kenichiro; Yamaguchi, Kouichi; Aoki, Fumiaki; Suga, Tatsuo; Nagai, Ryozo; Kurabayashi, Masahiko

2015-03-10

Alveolar macrophages play a crucial role in the pathogenesis of emphysema, for which there is currently no effective treatment. Bisphosphonates are widely used to treat osteoclast-mediated bone diseases. Here we show that delivery of the nitrogen-containing bisphosphonate alendronate via aerosol inhalation ameliorates elastase-induced emphysema in mice. Inhaled, but not orally ingested, alendronate inhibits airspace enlargement after elastase instillation, and induces apoptosis of macrophages in bronchoalveolar fluid via caspase-3- and mevalonate-dependent pathways. Cytometric analysis indicates that the F4/80(+)CD11b(high)CD11c(mild) population characterizing inflammatory macrophages, and the F4/80(+)CD11b(mild)CD11c(high) population defining resident alveolar macrophages take up substantial amounts of the bisphosphonate imaging agent OsteoSense680 after aerosol inhalation. We further show that alendronate inhibits macrophage migratory and phagocytotic activities and blunts the inflammatory response of alveolar macrophages by inhibiting nuclear factor-κB signalling. Given that the alendronate inhalation effectively induces apoptosis in both recruited and resident alveolar macrophages, we suggest this strategy may have therapeutic potential for the treatment of emphysema.

Myosin IIA-related Actomyosin Contractility Mediates Oxidative Stress-induced Neuronal Apoptosis

PubMed Central

Wang, Yan; Xu, Yingqiong; Liu, Qian; Zhang, Yuanyuan; Gao, Zhen; Yin, Mingzhu; Jiang, Nan; Cao, Guosheng; Yu, Boyang; Cao, Zhengyu; Kou, Junping

2017-01-01

Oxidative stress-induced neuronal apoptosis plays an important role in the progression of central nervous system (CNS) diseases. In our study, when neuronal cells were exposed to hydrogen peroxide (H2O2), an exogenous oxidant, cell apoptosis was observed with typical morphological changes including membrane blebbing, neurite retraction and cell contraction. The actomyosin system is considered to be responsible for the morphological changes, but how exactly it regulates oxidative stress-induced neuronal apoptosis and the distinctive functions of different myosin II isoforms remain unclear. We demonstrate that myosin IIA was required for neuronal contraction, while myosin IIB was required for neuronal outgrowth in normal conditions. During H2O2-induced neuronal apoptosis, myosin IIA, rather than IIB, interacted with actin filaments to generate contractile forces that lead to morphological changes. Moreover, myosin IIA knockout using clustered regularly interspaced short palindromic repeats/CRISPR-associated protein-9 nuclease (CRISPR/Cas9) reduced H2O2-induced neuronal apoptosis and the associated morphological changes. We further demonstrate that caspase-3/Rho-associated kinase 1 (ROCK1) dependent phosphorylation of myosin light chain (MLC) was required for the formation of the myosin IIA-actin complex. Meanwhile, either inhibition of myosin II ATPase with blebbistatin or knockdown of myosin IIA with siRNA reversely attenuated caspase-3 activation, suggesting a positive feedback loop during oxidative stress-induced apoptosis. Based on our observation, myosin IIA-actin complex contributes to actomyosin contractility and is associated with the positive feedback loop of caspase-3/ROCK1/MLC pathway. This study unravels the biochemical and mechanistic mechanisms during oxidative stress-induced neuronal apoptosis and may be applicable for the development of therapies for CNS diseases. PMID:28352215

Mitochondria-targeted platinum(II) complexes induce apoptosis-dependent autophagic cell death mediated by ER-stress in A549 cancer cells.

PubMed

Wang, Feng-Yang; Tang, Xiao-Ming; Wang, Xia; Huang, Ke-Bin; Feng, Hai-Wen; Chen, Zhen-Feng; Liu, You-Nian; Liang, Hong

2018-06-09

Agents with multiple modes of tumor cell death can be effective chemotherapeutic drugs. One example of a bimodal chemotherapeutic approach is an agent that can induce both apoptosis and autophagic death. Thus far, no clinical anticancer drug has been shown to simultaneously induce both these pathways. Mono-functional platinum complexes are potent anticancer drug candidates which act through mechanisms distinct from cisplatin. Here, we describe the synthesis and characterize of two mono-functional platinum complexes containing 8-substituted quinoline derivatives as ligands, [PtL 1 Cl]Cl [L 1  = (Z)-1-(pyridin-2-yl)-N-(quinolin-8-ylmethylene) methanamine] (Mon-Pt-1) and [PtL 2 Cl]Cl [L 2  = (Z)-2-(pyridin-2-yl)-N-(quinolin-8-ylmethylene) ethanamine] (Mon-Pt-2). In comparison to cisplatin, Mon-Pt-2 exhibited a greater in vitro cytotoxicity, was more effective in resistant cells and elicited a better anticancer effect. Mechanistic experiments indicate that Mon-Pt-2 mainly accumulates in mitochondria, and stimulates significant TrxR inhibition ROS release and an ER stress response, mediated by mitochondrial dysfunction, ultimately resulting in a simultaneous induction of apoptosis and autophagy. Importantly, compared to cisplatin, Mon-Pt-2 exhibits lower acute toxicity and better anticancer activity in a murine tumor model. To the best of our knowledge, Mon-Pt-2 is the first mono-functional platinum complex inducing pro-death autophagy and apoptosis of cancer cells. Copyright © 2018 The Authors. Published by Elsevier Masson SAS.. All rights reserved.

Wavelength-dependent backscattering measurements for quantitative monitoring of apoptosis, Part 1: early and late spectral changes are indicative of the presence of apoptosis in cell cultures

NASA Astrophysics Data System (ADS)

Mulvey, Christine S.; Zhang, Kexiong; Liu, Wei-Han Bobby; Waxman, David J.; Bigio, Irving J.

2011-11-01

Apoptosis, a form of programmed cell death with unique morphological and biochemical features, is dysregulated in cancer and is activated by many cancer chemotherapeutic drugs. Noninvasive assays for apoptosis in cell cultures can aid in screening of new anticancer agents. We have previously demonstrated that elastic scattering spectroscopy can monitor apoptosis in cell cultures. In this report we present data on monitoring the detailed time-course of scattering changes in a Chinese hamster ovary (CHO) and PC-3 prostate cancer cells treated with staurosporine to induce apoptosis. Changes in the backscattering spectrum are detectable within 10 min, and continue to progress up to 48 h after staurosporine treatment, with the magnitude and kinetics of scattering changes dependent on inducer concentration. Similar responses were observed in CHO cells treated with several other apoptosis-inducing protocols. Early and late scattering changes were observed under conditions shown to induce apoptosis via caspase activity assay and were absent under conditions where apoptosis was not induced. Finally, blocking caspase activity and downstream apoptotic morphology changes prevented late scattering changes. These observations demonstrate that early and late changes in wavelength-dependent backscattering correlate with the presence of apoptosis in cell cultures and that the late changes are specific to apoptosis.

Platinum Nanoparticles Induce Apoptosis on Raw 264.7 Macrophage Cells.

PubMed

Loan, Ta Thi; Do, Le Thanh; Yoo, Hoon

2018-02-01

The cellular effects of platinum nanoparticles (PNP05, average size of 5 nm, and PNP30, average size of 30 nm) were investigated on murine leukemia Raw 264.7 cells. Cells treated with various concentrations of PNPs showed size-dependent cytotoxicity in an MTT assay with PNP5 of smaller nanoparticles higher toxicity than PNP30. Investigations on cell morphology, Annexin V assay, DNA fragmentation and the activity of caspase-3/-7 showed that PNPs induced apoptosis on Raw 264.7 cells by changing cell morphology and density, increasing cell population in apoptosis and causing nucleus fragmentation. Further study on caspase activity by Western blotting revealed that the apoptosis was induced by the activation of caspase-3 and -7. In addition, PNPs inactivated DNA repair system, generating dose-dependent DNA ladder bands on agarose gel electrophoresis. Taken together, PNPs triggered cytotoxicity on Raw 264.7 cells by suppressing cell growth/survival and inducing apoptosis.

Histone deacetylase inhibitors VPA and TSA induce apoptosis and autophagy in pancreatic cancer cells.

PubMed

Gilardini Montani, Maria Saveria; Granato, Marisa; Santoni, Claudio; Del Porto, Paola; Merendino, Nicolò; D'Orazi, Gabriella; Faggioni, Alberto; Cirone, Mara

2017-04-01

Histone deacetylase inhibitors (HDACi) are anti-neoplastic agents that are known to affect the growth of different cancer types, but their underlying mechanisms are still incompletely understood. Here, we compared the effects of two HDACi, i.e., Trichostatin A (TSA) and Valproic Acid (VPA), on the induction of cell death and autophagy in pancreatic cancer-derived cells that exhibit a high metastatic capacity and carry KRAS/p53 double mutations. Cell viability and proliferation tests were carried out using Trypan blue dye exclusion, MTT and BrdU assays. FACS analyses were carried out to assess cell cycle progression, apoptosis, reactive oxygen species (ROS) production and mitochondrial depolarization, while Western blot and immunoprecipitation analyses were employed to detect proteins involved in apoptosis and autophagy. We found that both VPA and TSA can induce apoptosis in Panc1 and PaCa44 pancreatic cancer-derived cells by triggering mitochondrial membrane depolarization, Cytochrome c release and Caspase 3 activation, although VPA was more effective than TSA, especially in Panc1 cells. As underlying molecular events, we found that ERK1/2 was de-phosphorylated and that the c-Myc and mutant p53 protein levels were reduced after VPA and, to a lesser extent, after TSA treatment. Up-regulation of p21 and Puma was also observed, concomitantly with mutant p53 degradation. In addition, we found that in both cell lines VPA increased the pro-apoptotic Bim level, reduced the anti-apoptotic Mcl-1 level and increased ROS production and autophagy, while TSA was able to induce these effects only in PaCA44 cells. From our results we conclude that both VPA and TSA can induce pancreatic cancer cell apoptosis and autophagy. VPA appears have a stronger and broader cytotoxic effect than TSA and, thus, may represent a better choice for anti-pancreatic cancer therapy.

Evaluation of the neuronal apoptotic pathways involved in cytoskeletal disruption-induced apoptosis.

PubMed

Jordà, Elvira G; Verdaguer, Ester; Jimenez, Andrés; Arriba, S Garcia de; Allgaier, Clemens; Pallàs, Mercè; Camins, Antoni

2005-08-01

The cytoskeleton is critical to neuronal functioning and survival. Cytoskeletal alterations are involved in several neurodegenerative diseases such as Alzheimer's and Parkinson's diseases. We studied the possible pathways involved in colchicine-induced apoptosis in cerebellar granule neurons (CGNs). Although colchicine evoked an increase in caspase-3, caspase-6 and caspase-9 activation, selective caspase inhibitors did not attenuate apoptosis. Inhibitors of other cysteine proteases such as PD150606 (a calpain-specific inhibitor), Z-Phe-Ala fluoromethyl ketone (a cathepsins-inhibitors) and N(alpha)-p-tosyl-l-lysine chloromethyl ketone (serine-proteases inhibitor) also had no effect on cell death/apoptosis induced by colchicine. However, BAPTA-AM 10 microM (intracellular calcium chelator) prevented apoptosis mediated by cytoskeletal alteration. These data indicate that calcium modulates colchicine-induced apoptosis in CGNs. PARP-1 inhibitors did not prevent apoptosis mediated by colchicine. Finally, colchicine-induced apoptosis in CGNs was attenuated by kenpaullone, a cdk5 inhibitor. Kenpaullone and indirubin also prevented cdk5/p25 activation mediated by colchicine. These findings indicate that cytoskeletal alteration can compromise cdk5 activation, regulating p25 formation and suggest that cdk5 inhibitors attenuate apoptosis mediated by cytoskeletal alteration. The present data indicate the potential therapeutic value of drugs that prevent the formation of p25 for the treatment of neurodegenerative disorders.

[Study on thaspine in inducing apoptosis of A549 cell].

PubMed

Zhang, Yan-min; He, Lang-chong

2007-04-01

To investigate the effect of thaspine on the cellular proliferation, apoptosis and cell cycle in A549 cell line. A549 cell was cultured with different concentrations of thaspine. Cellular proliferation was detected with MTT, apoptosis and cell cycle were checked with Flow Cytometer, and change of microstructure was observed by transmission electron microscope. Thaspine could inhibit the proliferation and induce apoptosis of A549 cell in a time-dose dependent manner. Cell cycle was significantly stopped at the S phase by thaspine with FCM technology. Under electronic microscope, the morphology of A549 cell showed nuclear karyopycnosis, chromatin agglutination and typical apoptotic body when the cell was treated with thaspine. Thaspine has the effects of anti-tumor and inducing apoptosis.

Berberine potentizes apoptosis induced by X-rays irradiation probably through modulation of gap junctions.

PubMed

Liu, Bing; Wang, Qin; Yuan, Dong-dong; Hong, Xiao-ting; Tao, Liang

2011-04-01

Clinical combination of some traditional Chinese medical herbs, including berberine, with irradiation is demonstrated to improve efficacy of tumor radiotherapy, yet the mechanisms for such effect remain largely unknown. The present study investigated the effect of berberine on apoptosis induced by X-rays irradiation and the relation between this effect and gap junction intercellular communication (GJIC). The role of gap junctions in the modulation of X-rays irradiation-induced apoptosis was explored by manipulation of connexin (Cx) expression, and gap junction function, using oleamide, a GJIC inhibitor, and berberine. In transfected HeLa cells, Cx32 expression increased apoptosis induced by X-rays irradiation, while inhibition of gap junction by oleamide reduced the irradiation responses, indicating the dependence of X-rays irradiation-induced apoptosis on GJIC. Berberine, at the concentrations without cytotoxicity, enhanced apoptosis induced by irradiation only in the presence of functional gap junctions. These results suggest that berberine potentizes cell apoptosis induced by X-rays irradiation, probably through enhancement of gap junction activity.

Influenza virus induces apoptosis via BAD-mediated mitochondrial dysregulation.

PubMed

Tran, Anh T; Cortens, John P; Du, Qiujiang; Wilkins, John A; Coombs, Kevin M

2013-01-01

Influenza virus infection results in host cell death and major tissue damage. Specific components of the apoptotic pathway, a signaling cascade that ultimately leads to cell death, are implicated in promoting influenza virus replication. BAD is a cell death regulator that constitutes a critical control point in the intrinsic apoptosis pathway, which occurs through the dysregulation of mitochondrial outer membrane permeabilization and the subsequent activation of downstream apoptogenic factors. Here we report a novel proviral role for the proapoptotic protein BAD in influenza virus replication. We show that influenza virus-induced cytopathology and cell death are considerably inhibited in BAD knockdown cells and that both virus replication and viral protein production are dramatically reduced, which suggests that virus-induced apoptosis is BAD dependent. Our data showed that influenza viruses induced phosphorylation of BAD at residues S112 and S136 in a temporal manner. Viral infection also induced BAD cleavage, late in the viral life cycle, to a truncated form that is reportedly a more potent inducer of apoptosis. We further demonstrate that knockdown of BAD resulted in reduced cytochrome c release and suppression of the intrinsic apoptotic pathway during influenza virus replication, as seen by an inhibition of caspases-3, caspase-7, and procyclic acidic repetitive protein (PARP) cleavage. Our data indicate that influenza viruses carefully modulate the activation of the apoptotic pathway that is dependent on the regulatory function of BAD and that failure of apoptosis activation resulted in unproductive viral replication.

Influenza Virus Induces Apoptosis via BAD-Mediated Mitochondrial Dysregulation

PubMed Central

Tran, Anh T.; Cortens, John P.; Du, Qiujiang; Wilkins, John A.

2013-01-01

Influenza virus infection results in host cell death and major tissue damage. Specific components of the apoptotic pathway, a signaling cascade that ultimately leads to cell death, are implicated in promoting influenza virus replication. BAD is a cell death regulator that constitutes a critical control point in the intrinsic apoptosis pathway, which occurs through the dysregulation of mitochondrial outer membrane permeabilization and the subsequent activation of downstream apoptogenic factors. Here we report a novel proviral role for the proapoptotic protein BAD in influenza virus replication. We show that influenza virus-induced cytopathology and cell death are considerably inhibited in BAD knockdown cells and that both virus replication and viral protein production are dramatically reduced, which suggests that virus-induced apoptosis is BAD dependent. Our data showed that influenza viruses induced phosphorylation of BAD at residues S112 and S136 in a temporal manner. Viral infection also induced BAD cleavage, late in the viral life cycle, to a truncated form that is reportedly a more potent inducer of apoptosis. We further demonstrate that knockdown of BAD resulted in reduced cytochrome c release and suppression of the intrinsic apoptotic pathway during influenza virus replication, as seen by an inhibition of caspases-3, caspase-7, and procyclic acidic repetitive protein (PARP) cleavage. Our data indicate that influenza viruses carefully modulate the activation of the apoptotic pathway that is dependent on the regulatory function of BAD and that failure of apoptosis activation resulted in unproductive viral replication. PMID:23135712

Withaferin-A Induces Apoptosis in Osteosarcoma U2OS Cell Line via Generation of ROS and Disruption of Mitochondrial Membrane Potential.

PubMed

Zhang, Hui-Liang; Zhang, Hong

2017-01-01

Withaferin-A (WF-A) is a well-known dietary compound isolated from Withania sominifera . It has tremendous pharmacological potential and has been shown to exhibit antiproliferative activity against several types of cancerous cells. Currently, the main focus of anti-cancer therapeutic development is to identify apoptosis inducing drug-like molecules. Osteosarcoma is a rare type of osteocancer, affecting human. The present study therefore focused on the evaluation of antitumor potential of WF-A against several osteosarcoma cell lines. MTT assay was used to evaluate WF-A against osteosarcoma cell lines and to calculate the IC 50 . DAPI staining was used to confirm the apoptosis inducing potential of WF-A. Mitochondrial membrane potential, reactive oxygen species (ROS) assay, and Western blotting were used to confirm the basis of apoptosis. The results revealed that that WF-A exhibited strong antiproliferative activity against all the cells lines, with IC 50 ranging from 0.32 to 7.6 μM. The lowest IC 50 (0.32 μM) was observed against U2OS cell line and therefore it was selected for further analysis. DAPI staining indicated that WF-A exhibited antiproliferative activity via induction of apoptosis. Moreover, WF-A induced ROS-mediated reduction in mitochondrial membrane potential ΔΨm) in a dose-dependent manner and activation of caspase-3 in osteosarcoma cells. We propose that WF-A may prove a potent therapeutic agent for inducing apoptosis in osteosarcoma cell lines via generation of ROS and disruption of mitochondrial membrane potential. WF-A exhibits strong anticancer activity against osteosarcoma cell linesAntiproliferative activity of WF-A is via induction of apoptosisWF-A induced ROS-mediated reduction in mitochondrial membrane potentialWF-A induced expression of caspase-3 in osteosarcoma cells. Abbreviations used: WA: Withaferin A; ROS: Reactive oxygen species; OS: Osteosarcoma; MMP: Mitochondrial membrane potential.

Steroid Receptor Coactivator-interacting Protein (SIP) Inhibits Caspase-independent Apoptosis by Preventing Apoptosis-inducing Factor (AIF) from Being Released from Mitochondria*

PubMed Central

Wang, Dandan; Liang, Jing; Zhang, Yu; Gui, Bin; Wang, Feng; Yi, Xia; Sun, Luyang; Yao, Zhi; Shang, Yongfeng

2012-01-01

Apoptosis-inducing factor (AIF) is a caspase-independent death effector. Normally residing in the mitochondrial intermembrane space, AIF is released and translocated to the nucleus in response to proapoptotic stimuli. Nuclear AIF binds to DNA and induces chromatin condensation and DNA fragmentation, characteristics of apoptosis. Until now, it remained to be clarified how the mitochondrial-nuclear translocation of AIF is regulated. Here we report that steroid receptor coactivator-interacting protein (SIP) interacts directly with AIF in mitochondria and specifically inhibits caspase-independent and AIF-dependent apoptosis. Challenging cells with apoptotic stimuli leads to rapid degradation of SIP, and subsequently AIF is liberated from mitochondria and translocated to the nucleus to induce apoptosis. Together, our data demonstrate that SIP is a novel regulator in caspase-independent and AIF-mediated apoptosis. PMID:22371500

Correlation between radio-induced lymphocyte apoptosis measurements obtained from two French centres.

PubMed

Mirjolet, C; Merlin, J L; Dalban, C; Maingon, P; Azria, D

2016-07-01

In the era of modern treatment delivery, increasing the dose delivered to the target to improve local control might be modulated by the patient's intrinsic radio-sensitivity. A predictive assay based on radio-induced lymphocyte apoptosis quantification highlighted the significant correlation between CD4 and CD8 T-lymphocyte apoptosis and grade 2 or 3 radiation-induced late toxicities. By conducting this assay at several technical platforms, the aim of this study was to demonstrate that radio-induced lymphocyte apoptosis values obtained from two different platforms were comparable. For 25 patients included in the PARATOXOR trial running in Dijon the radio-induced lymphocyte apoptosis results obtained from the laboratory of Montpellier (IRCM, Inserm U1194, France), considered as the reference (referred to as Lab 1), were compared with those from the laboratory located at the Institut de cancérologie de Lorraine (ICL, France), referred to as Lab 2. Different statistical methods were used to measure the agreement between the radio-induced lymphocyte apoptosis data from the two laboratories (quantitative data). The Bland-Altman plot was used to identify potential bias. All statistical tests demonstrated good agreement between radio-induced lymphocyte apoptosis values obtained from both sites and no major bias was identified. Since radio-induced lymphocyte apoptosis values, which predict tolerance to radiotherapy, could be assessed by two laboratories and showed a high level of robustness and consistency, we can suggest that this assay be extended to any laboratories that use the same technique. Copyright © 2016 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.

Myostatin induces mitochondrial metabolic alteration and typical apoptosis in cancer cells

PubMed Central

Liu, Y; Cheng, H; Zhou, Y; Zhu, Y; Bian, R; Chen, Y; Li, C; Ma, Q; Zheng, Q; Zhang, Y; Jin, H; Wang, X; Chen, Q; Zhu, D

2013-01-01

Myostatin, a member of the transforming growth factor-β superfamily, regulates the glucose metabolism of muscle cells, while dysregulated myostatin activity is associated with a number of metabolic disorders, including muscle cachexia, obesity and type II diabetes. We observed that myostatin induced significant mitochondrial metabolic alterations and prolonged exposure of myostatin induced mitochondria-dependent apoptosis in cancer cells addicted to glycolysis. To address the underlying mechanism, we found that the protein levels of Hexokinase II (HKII) and voltage-dependent anion channel 1 (VDAC1), two key regulators of glucose metabolisms as well as metabolic stress-induced apoptosis, were negatively correlated. In particular, VDAC1 was dramatically upregulated in cells that are sensitive to myostatin treatment whereas HKII was downregulated and dissociated from mitochondria. Myostatin promoted the translocation of Bax from cytosol to mitochondria, and knockdown of VDAC1 inhibited myostatin-induced Bax translocation and apoptosis. These apoptotic changes can be partially rescued by repletion of ATP, or by ectopic expression of HKII, suggesting that perturbation of mitochondrial metabolism is causally linked with subsequent apoptosis. Our findings reveal novel function of myostatin in regulating mitochondrial metabolism and apoptosis in cancer cells. PMID:23412387

BH3-Only Protein BIM Mediates Heat Shock-Induced Apoptosis

PubMed Central

Mahajan, Indra M.; Chen, Miao-Der; Muro, Israel; Robertson, John D.; Wright, Casey W.; Bratton, Shawn B.

2014-01-01

Acute heat shock can induce apoptosis through a canonical pathway involving the upstream activation of caspase-2, followed by BID cleavage and stimulation of the intrinsic pathway. Herein, we report that the BH3-only protein BIM, rather than BID, is essential to heat shock-induced cell death. We observed that BIM-deficient cells were highly resistant to heat shock, exhibiting short and long-term survival equivalent to Bax−/−Bak−/− cells and better than either Bid−/− or dominant-negative caspase-9-expressing cells. Only Bim−/− and Bax−/−Bak−/− cells exhibited resistance to mitochondrial outer membrane permeabilization and loss of mitochondrial inner membrane potential. Moreover, while dimerized caspase-2 failed to induce apoptosis in Bid−/− cells, it readily did so in Bim−/− cells, implying that caspase-2 kills exclusively through BID, not BIM. Finally, BIM reportedly associates with MCL-1 following heat shock, and Mcl-1−/− cells were indeed sensitized to heat shock-induced apoptosis. However, pharmacological inhibition of BCL-2 and BCL-XL with ABT-737 also sensitized cells to heat shock, most likely through liberation of BIM. Thus, BIM mediates heat shock-induced apoptosis through a BAX/BAK-dependent pathway that is antagonized by antiapoptotic BCL-2 family members. PMID:24427286

Molecular mechanisms of hyperthermia-induced apoptosis enhanced by withaferin A.

PubMed

Cui, Zheng-Guo; Piao, Jin-Lan; Rehman, Mati U R; Ogawa, Ryohei; Li, Peng; Zhao, Qing-Li; Kondo, Takashi; Inadera, Hidekuni

2014-01-15

Hyperthermia is a good therapeutic tool for non-invasive cancer therapy; however, its cytotoxic effects are not sufficient. In the present study, withaferin A (WA), a steroidal lactone derived from the plant Withania somnifera Dunal, has been investigated for its possible enhancing effects on hyperthermia-induced apoptosis. In HeLa cells, treatment with 0.5 or 1.0μM WA at 44°C for 30min induced significant apoptosis accompanied by decreased intracellular GSH/GSSG ratio and caspase-3 activation, while heat or WA alone did not induce such changes. The upregulation in apoptosis was significantly inhibited by glutathione monoethyl ester, a cell permeable glutathione precursor. Mitochondrial transmembrane potentials were dramatically decreased by the combined treatment, with increases in pro-apoptotic Bcl-2-family proteins tBid and Noxa, and downregulation of antiapoptotic Bcl-2 and Mcl-1. Combined treatment with hyperthermia and WA induced significant increases in JNK phosphorylation (p-JNK), and decreases in the phosphorylation of ERK (p-ERK) compared with either treatment alone. These results suggest that WA enhances hyperthermia-induced apoptosis via a mitochondria-caspase-dependent pathway; its underlying mechanism involves elevated intracellular oxidative stress, mitochondria dysfunction, and JNK activation. © 2013 Elsevier B.V. All rights reserved.

Down-regulated RPS3a/nbl expression during retinoid-induced differentiation of HL-60 cells: a close association with diminished susceptibility to actinomycin D-stimulated apoptosis.

PubMed

Russell, L; Naora, H; Naora, H

2000-04-01

The efficacy of anticancer agents significantly depends on the differential susceptibility of undifferentiated cancer cells and differentiated normal cells to undergo apoptosis. We previously found that enhanced expression of RPS3a/nbl, which apparently encodes a ribosomal protein, seems to prime cells for apoptosis, while suppressing such enhanced expression triggers cell death. The present study found that HL-60 cells induced to differentiate by all-trans retinoic acid did not undergo apoptosis following treatment with actinomycin D whereas undifferentiated HL-60 cells were highly apoptosis-susceptible, confirming earlier suggestions that differentiated cells have diminished apoptosis-susceptibility. Undifferentiated HL-60 cells highly expressed RPS3a/nbl whereas all-trans retinoic acid -induced differentiated cells exhibited markedly reduced levels, suggesting that apoptosis-resistance of differentiated cells could be due to low RPS3a/nbl expression. Down-regulation of enhanced RPS3a/nbl expression was also observed in cells induced to differentiate with the retinoid 4-[(E)-2-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-napthalenyl)-1- propenyl]benzoic acid without any significant induction of cell death. While down-regulation of RPS3a/nbl expression during differentiation did not apparently induce apoptosis, RPS3a/nbl antisense oligomers triggered death of undifferentiated HL-60 cells, but not of retinoid-induced differentiated cells. It therefore seems that while down-regulation of enhanced RPS3a/nbl expression can induce apoptosis in undifferentiated cells, down-regulation of enhanced RPS3a/nbl expression during differentiation occurs independently of apoptosis, and could be regarded as reverting the primed condition to the unprimed (low RPS3a/nbl) state.

Sulfur mustard-induced apoptosis in hairless guinea pig skin.

PubMed

Kan, Robert K; Pleva, Christina M; Hamilton, Tracey A; Anderson, Dana R; Petrali, John P

2003-01-01

The present study was aimed to examine whether apoptosis is involved in the pathogenesis of sulfur mustard (SM)-induced basal cell death. Skin sites of the hairless guinea pig exposed to SM vapor for 8 minutes were harvested at 3, 6, 12, 24, and 48 hours postexposure. Immunohistochemical detection of basal cell apoptosis was performed using the ApopTag in situ apoptosis labeling kit. Only occasional apoptotic basal cells (BC)were observed in nonexposed and perilesional control sites. At lesional sites, apoptosis of BC was not detected at 3 hours postexposure. However, at 6 hours and 12 hours postexposure, 18% and 59% of BC were apoptotic, respectively. At 24 and 48 hours postexposure, individual apoptotic basal cells were not clearly recognizable due to necrosis. At the ultrastructural level, degenerating BC exhibited typical apoptotic morphology including nuclear condensation and chromatin margination. The results suggest that apoptotic cell death is a cytotoxic mechanism with the number of BC undergoing apoptosis significantly increasing from 6 to 12 hours postexposure. In addition, because necrosis is preferential at 24 hours postexposure, we believe that SM-induced cell death involves early apoptosis and late necrosis, which temporally overlap to produce a single cell death pathway along an apoptotic-necrotic continuum.

Modulation of ceramide metabolism in T-leukemia cell lines potentiates apoptosis induced by the cationic antimicrobial peptide bovine lactoferricin.

PubMed

Furlong, Suzanne J; Ridgway, Neale D; Hoskin, David W

2008-03-01

Bovine lactoferricin (LfcinB) is a cationic antimicrobial peptide that selectively induces apoptosis in several different types of human cancer cells. However, the potential use of LfcinB as an anticancer agent is presently limited by the need for relatively high concentrations of the peptide to trigger apoptosis. Ceramide is a membrane sphingolipid that is believed to function as a second messenger during apoptosis. In this study, we investigated the role of ceramide in LfcinB-induced apoptosis in CCRF-CEM and Jurkat T-leukemia cell lines. Exposure to LfcinB caused nuclear condensation and fragmentation, poly(ADP-ribose) polymerase (PARP) cleavage, and DNA fragmentation in CCRF-CEM and Jurkat T-cell acute lymphoblastic leukemia cell lines. Treatment with C6 ceramide, a cell-permeable, short-chain ceramide analog, also induced apoptotic nuclear morphology, PARP cleavage, and DNA fragmentation in T-leukemia cells. Although LfcinB treatment did not cause ceramide to accumulate in CCRF-CEM or Jurkat cells, the addition of C6 ceramide to LfcinB-treated T-leukemia cells resulted in increased DNA fragmentation. Furthermore, modulation of cellular ceramide metabolism either by inhibiting ceramidases with D-erythro-2-(N-myristoylamino)-1-phenyl-1-propanol or N-oleoylethanolamine, or by blocking glucosylceramide synthase activity with 1-phenyl-2-palmitoylamino-3-morpholino-1-propanol, enhanced the ability of LfcinB to trigger apoptosis in both Jurkat and CCRF-CEM cells. In addition, LfcinB-induced apoptosis of T-leukemia cells was enhanced in the presence of the antiestrogen tamoxifen, which has multiple effects on cancer cells, including inhibition of glucosylceramide synthase activity. We conclude that manipulation of cellular ceramide levels in combination with LfcinB therapy warrants further investigation as a novel strategy for the treatment of T cell-derived leukemias.

Apoptosis-inducing and apoptosis-preventing functions of poliovirus.

PubMed Central

Tolskaya, E A; Romanova, L I; Kolesnikova, M S; Ivannikova, T A; Smirnova, E A; Raikhlin, N T; Agol, V I

1995-01-01

Data showing that an apoptotic reaction (the exit into the cytoplasm and nucleolytic internucleosomal degradation of chromosomal DNA, compaction and fragmentation of chromatin, cellular shrinkage, and cytoplasmic blebbing) developed in a subline of HeLa-S3 cells upon nonpermissive poliovirus infection with either a guanidine-sensitive poliovirus in the presence of guanidine, a guanidine-dependent mutant in the absence of guanidine, or certain temperature-sensitive mutants at a restrictive temperature are presented. Essentially, no apoptotic reaction occurred upon permissive infection of these cells. Both permissive and nonpermissive infections resulted in the inhibition of host protein synthesis. Actinomycin D or cycloheximide also elicited a rapid apoptotic reaction in uninfected cells. However, preinfection or coinfection with poliovirus prevented the apoptotic response to the addition of actinomycin D, and preinfection blocked cycloheximide-induced apoptosis as well. These data fit a model in which the cells used are prepared to develop apoptosis, with their viability due to the presence of certain short-lived mRNA and protein species. Poliovirus infection turns on two oppositely directed sets of reactions. On the one hand, the balance is driven toward apoptosis, probably via the shutoff of host macromolecular synthesis. On the other hand, viral protein exhibits antiapoptotic activity, thereby preventing premature cell death. To our knowledge, this is the first description of an antiapoptotic function for an RNA virus. PMID:7529330

Methotrexate Induces Apoptosis in Organ-Cultured Nasal Polyps Via the Fas Pathway.

PubMed

Heo, Kyung Wook; Park, Seong Kook; Lee, Yeo Myeong; Choe, Si Hong; Gu, Pyung Mo; Hong, Tae Ui; Hur, Dae Young

2017-05-01

Methotrexate (MTX) is very effective when used to treat chronic inflammatory diseases, and also induces apoptosis in nasal polyps (NPs). Increasing evidence suggests that Fas-Fas ligand (FasL) interactions activate multiple pathways involved in the regulation of immune and inflammatory cell functions. The aim of the present study was to identify pathways activated by Fas signaling when NPs were treated with MTX. Nasal polyps tissues were cultured using an air-liquid interface organ culture method. Cultures were maintained in the absence or presence of MTX (10 or 100 μM) for 24 hours. The authors used the reverse transcription-polymerase chain reaction method and Western blotting to identify pathways activated by Fas when NPs were treated with MTX. The Fas mRNA expression ratio was unchanged upon MTX treatment, but the FasL mRNA expression ratio was significantly higher in MTX-treated than nontreated polyps. In addition, the expression levels of the Fas and FasL proteins were significantly higher in polyps treated with both 10 and 100 μM MTX compared with nontreated polyps. Methotrexate induces apoptosis in NPs via the Fas pathway. Future studies should explore the topical use of MTX for NP control. Methotrexate may be a useful alternative steroid-sparing agent for the treatment of NPs.

Effects of losartan on experimental varicocele-induced testicular germ cell apoptosis.

PubMed

Bolat, D; Oltulu, F; Uysal, A; Kose, T; Gunlusoy, B; Yigitturk, G; Turk, N S; Turan, T

2016-09-01

To investigate the potential protective effects of losartan on varicocele-induced germ cell apoptosis, 24 adult male Sprague Dawley rats were divided into three groups: a sham operation was performed in SHAM group, and experimental left varicocele was created in VAR and VAR + LOS groups. Additionally, in VAR + LOS group, losartan was administered for 30 days starting on the day of surgery. At the end of 30 days, all animals were sacrificed and left orchiectomy was performed. Testicular injury and spermatogenesis were evaluated according to Johnsen scoring system. To assess the nitrosative stress, immunohistochemical staining for endothelial nitric oxide synthase was used and evaluated by H-score and apoptotic index (AI) of germ cells was analysed by TUNEL method. A significant decrease in the mean Johnsen score (JS) was observed in VAR group compared with SHAM (p < .001). The mean H-score and AI were significantly higher in VAR group compared with SHAM (p < .001). After losartan administration, mean JS was significantly increased (p < .001) and mean H-score and AI were significantly decreased compared with VAR group (p < .001 and .01, respectively). Findings of this suggest that losartan acts as a potent protective agent against varicocele-induced germ cell apoptosis. © 2016 Blackwell Verlag GmbH.

Molecular mechanisms of euplotin C-induced apoptosis: involvement of mitochondrial dysfunction, oxidative stress and proteases.

PubMed

Cervia, Davide; Garcia-Gil, Mercedes; Simonetti, Elisa; Di Giuseppe, Graziano; Guella, Graziano; Bagnoli, Paola; Dini, Fernando

2007-08-01

The metabolite euplotin C (EC), isolated from the marine ciliate Euplotes crassus, is a powerful cytotoxic and pro-apoptotic agent in tumour cell lines. For instance, EC induces the rapid depletion of ryanodine Ca(2+) stores, the release of cytochrome c from the mitochondria, and the activation of caspase-3, leading to apoptosis. The purpose of this study was to gain further insight into the mechanisms of EC-induced apoptosis in rat pheochromocytoma PC12 cells. We found that EC increases Bax/Bcl-2 ratio and that Bax is responsible of the EC-induced dissipation of the mitochondrial membrane potential (Deltapsi(m)). In addition, EC induces the generation of reactive oxygene species (ROS) without involvement of p53. The inhibition of ROS generation prevents, at least in part, the pro-apoptotic effects of EC as well as the effects of EC on Bax, Deltapsi(m) and intracellular free Ca(2+), indicating a cross-talk between different pathways. However, definition of the effector cascade turns out to be more complex than expected and caspase-independent mechanisms, acting in parallel with caspases, should also be considered. Among them, EC increases the expression/activity of calpains downstream of ROS generation, although calpains seem to exert protective effects.

Mitochondria-dependent and -independent mechanisms in tumour necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis are both regulated by interferon-gamma in human breast tumour cells.

PubMed Central

Ruiz-Ruiz, Carmen; López-Rivas, Abelardo

2002-01-01

Tumour necrosis factor-related apoptosis-inducing ligand (TRAIL/APO-2L) induces apoptosis in a variety of tumour cells upon binding to death receptors TRAIL-R1 and TRAIL-R2. Here we describe the sensitization by interferon (IFN)-gamma to TRAIL-induced apoptosis in the breast tumour cell lines MCF-7 and MDA-MB231. IFN-gamma promoted TRAIL-mediated activation of caspase-8, Bcl-2 interacting domain death agonist (Bid) degradation, Bcl-2-associated X protein (Bax) translocation to mitochondria, cytochrome c release to the cytosol and activation of caspase-9 in these cell lines. No changes in the expression of TRAIL receptors were observed upon IFN-gamma treatment. Overexpression of Bcl-2 in MCF-7 cells completely inhibited IFN-gamma-induced sensitization to TRAIL-mediated cell death. Interestingly, TRAIL-induced apoptosis was also clearly enhanced by IFN-gamma in caspase-3-overexpressing MCF-7 cells, in the absence of Bax translocation to mitochondria and cytochrome c release to the cytosol. In summary, our results suggest that IFN-gamma facilitates TRAIL-induced activation of mitochondria-regulated as well as mitochondria-independent apoptotic pathways in breast tumour cells. PMID:11936954

Silver nanoparticles protect human keratinocytes against UVB radiation-induced DNA damage and apoptosis: potential for prevention of skin carcinogenesis

PubMed Central

Arora, Sumit; Tyagi, Nikhil; Bhardwaj, Arun; Rusu, Lilia; Palanki, Rohan; Vig, Komal; Singh, Shree R.; Singh, Ajay P.; Palanki, Srinivas; Miller, Michael E.; Carter, James E.; Singh, Seema

2015-01-01

Ultraviolet (UV)-B radiation from the sun is an established etiological cause of skin cancer, which afflicts more than a million lives each year in the United States alone. Here, we tested the chemopreventive efficacy of silver-nanoparticles (AgNPs) against UVB-irradiation-induced DNA damage and apoptosis in human immortalized keratinocytes (HaCaT). AgNPs were synthesized by reduction-chemistry and characterized for their physicochemical properties. AgNPs were well tolerated by HaCaT cells and their pretreatment protected them from UVB-irradiation-induced apoptosis along with significant reduction in cyclobutane-pyrimidine-dimer formation. Moreover, AgNPs pre-treatment led to G1-phase cell-cycle arrest in UVB-irradiated HaCaT cells. AgNPs were efficiently internalized in UVB-irradiated cells and localized into cytoplasmic and nuclear compartments. Furthermore, we observed an altered expression of various genes involved in cell-cycle, apoptosis and nucleotide-excision repair in HaCaT cells treated with AgNPs prior to UVB-irradiation. Together, these findings provide support for potential utility of AgNPs as novel chemopreventive agents against UVB-irradiation-induced skin carcinogenesis. PMID:25804413

3-Bromopyruvate and sodium citrate induce apoptosis in human gastric cancer cell line MGC-803 by inhibiting glycolysis and promoting mitochondria-regulated apoptosis pathway.

PubMed

Guo, Xingyu; Zhang, Xiaodong; Wang, Tingan; Xian, Shulin; Lu, Yunfei

2016-06-17

Cancer cells are mainly dependent on glycolysis to generate adenosine triphosphate (ATP) and intermediates required for cell growth and proliferation. Thus, inhibition of glycolysis might be of therapeutic value in antitumor treatment. Our previously studies had found that both 3-bromopyruvate (BP) and sodium citrate (SCT) can inhibit tumor growth and proliferation in vitro and in vivo. However, the mechanism involved in the BP and SCT mediated antitumor activity is not entirely clear. In this work, it is demonstrated that BP inhibits the enzyme hexokinase (HK) activity and SCT suppresses the phosphofructokinase (PFK) activity respectively, both the two agents decrease viability, ATP generation and lactate content in the human gastric cancer cell line MGC-803. These effects are directly correlated with blockage of glycolysis. Furthermore, BP and SCT can induce the characteristic manifestations of mitochondria-regulated apoptosis, such as down-regulation of anti-apoptosis proteins Bcl-2 and Survivin, up-regulation of pro-apoptosis protein Bax, activation of caspase-3, as well as leakage of cytochrome c (Cyt-c). In summary, our results provided evidences that BP and SCT inhibit the MGC-803 cells growth and proliferation might be correlated with inhibiting glycolysis and promoting mitochondria-regulated apoptosis. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Fasting-induced apoptosis in rat liver is blocked by cycloheximide.

PubMed

Tessitore, L; Tomasi, C; Greco, M

1999-08-01

The effect of cycloheximide (CH) on the fasting-induced changes of rat liver cell and protein turnover has been investigated. Late starvation phase (3-4-day-fasting period) was characterised by a decrease in liver weight and protein and DNA content. The loss of DNA was not related to liver cell necrosis but due not only to depression of cell proliferation as shown by the drop in the labelling index but also induction of apoptosis. This type of apoptosis was documented by the increase in the apoptotic index (cells labelled by TUNEL) and transglutaminase activity as well as by DNA fragmentation. The liver cells of fasted rats appeared smaller as shown by the higher cell density and DNA/protein ratio than in controls. Females were more resistant to fasting-induced apoptosis than males. A single dose of CH, a drug primary known as inhibitor of protein synthesis, induced or enhanced apoptosis in fed and 2-days fasted male rats, respectively, without any sign of cell necrosis. On the contrary, the administration of repeated doses of CH blocked apoptosis induced by fasting. CH "froze" protein and DNA content as well as apoptotic process at the level of 2 days-fasted rats. While fasting-induced liver protein loss resulted from a marked reduction in protein synthesis with a slight decrease in degradation, repeated treatment with CH virtually blocked protein loss by abolishing protein catabolism. These data suggest a direct relationship between the catabolic side of protein turnover and the apoptotic process.

Induction of ER Stress-Mediated Apoptosis by α-Lipoic Acid in A549 Cell Lines

PubMed Central

Kim, Jong In; Lee, Chang Min; Park, Eok-Sung; Kim, Ki Nyun; Kim, Hyung Chul; Lee, Hae Young

2012-01-01

Background α-Lipoic acid (α-LA) has been studied as an anticancer agent as well as a therapeutic agent for diabetes and obesity. We performed this study to evaluate the anticancer effects and mechanisms of α-LA in a lung cancer cell line, A549. Materials and Methods α-LA-induced apoptosis of A549 cells was detected by fluorescence-activated cell sorting analysis and a DNA fragmentation assay. Expression of apoptosis-related genes was analyzed by western blot and reverse transcription-polymerase chain reaction analyses. Results α-LA induced apoptosis and DNA fragmentation in A549 cells in a dose- and time-dependent manner. α-LA increased caspase activity and the degradation of poly (ADP-ribose) polymerase. It induced expression of endoplasmic reticulum (ER) stress-related genes, such as glucose-regulated protein 78, C/EBP-homologous protein, and the short form of X-box binding protein-1, and decreased expression of the anti-apoptotic protein, X-linked inhibitor of apoptosis protein. Reactive oxygen species (ROS) production was induced by α-LA, and the antioxidant N-acetyl-L-cysteine decreased the α-LA-induced increase in expression of apoptosis and ER stress-related proteins. Conclusion α-LA induced ER stress-mediated apoptosis in A549 cells via ROS. α-LA may therefore be clinically useful for treating lung cancer. PMID:22363901

Nitric oxide is cytoprotective to breast cancer spheroids vulnerable to estrogen-induced apoptosis

PubMed Central

Shafran, Yana; Zurgil, Naomi; Ravid-Hermesh, Orit; Sobolev, Maria; Afrimzon, Elena; Hakuk, Yaron; Shainberg, Asher; Deutsch, Mordechai

2017-01-01

Estrogen-induced apoptosis has become a successful treatment for postmenopausal metastatic, estrogen receptor-positive breast cancer. Nitric oxide involvement in the response to this endocrine treatment and its influence upon estrogen receptor-positive breast cancer progression is still unclear. Nitric oxide impact on the MCF7 breast cancer line, before and after estrogen-induced apoptosis, was investigated in 3D culture systems using unique live-cell imaging methodologies. Spheroids were established from MCF7 cells vulnerable to estrogen-induced apoptosis, before and after exposure to estrogen. Spheroids derived from estrogen-treated cells exhibited extensive apoptosis levels with downregulation of estrogen receptor expression, low proliferation rate and reduced metabolic activity, unlike spheroids derived from non-treated cells. In addition to basic phenotypic differences, these two cell cluster types are diverse in their reactions to exogenous nitric oxide. A dual effect of nitric oxide was observed in the breast cancer phenotype sensitive to estrogen-induced apoptosis. Nitric oxide, at the nanomolar level, induced cell proliferation, high metabolic activity, downregulation of estrogen receptor and enhanced collective invasion, contributing to a more aggressive phenotype. Following hormone supplementation, breast cancer 3D clusters were rescued from estrogen-induced apoptosis by these low nitric oxide-donor concentrations, since nitric oxide attenuates cell death levels, upregulates survivin expression and increases metabolic activity. Higher nitric oxide concentrations (100nM) inhibited cell growth, metabolism and promoted apoptosis. These results suggest that nitric oxide, in nanomolar concentrations, may inhibit estrogen-induced apoptosis, playing a major role in hormonal therapy. Inhibiting nitric oxide activity may benefit breast cancer patients and ultimately reduce tumor recurrence. PMID:29312577

Myricitrin Alleviates Oxidative Stress-induced Inflammation and Apoptosis and Protects Mice against Diabetic Cardiomyopathy

PubMed Central

Zhang, Bin; Shen, Qiang; Chen, Yaping; Pan, Ruile; Kuang, Shihuan; Liu, Guiyan; Sun, Guibo; Sun, Xiaobo

2017-01-01

Diabetic cardiomyopathy (DCM) has been increasingly considered as a main cause of heart failure and death in diabetic patients. At present, no effective treatment exists to prevent its development. In the present study, we describe the potential protective effects and mechanisms of myricitrin (Myr) on the cardiac function of streptozotosin-induced diabetic mice and on advanced glycation end products (AGEs)-induced H9c2 cardiomyocytes. In vitro experiments revealed that pretreatment with Myr significantly decreased AGEs-induced inflammatory cytokine expression, limited an increase in ROS levels, and reduced cell apoptosis, fibrosis, and hypertrophy in H9c2 cells. These effects are correlated with Nrf2 activation and NF-κB inhibition. In vivo investigation demonstrated that oral administration of Myr at 300 mg/kg/day for 8 weeks remarkably decreased the expression of enzymes associated with cardiomyopathy, as well as the expression of inflammatory cytokines and apoptotic proteins. Finally, Myr improved diastolic dysfunction and attenuated histological abnormalities. Mechanistically, Myr attenuated diabetes-induced Nrf2 inhibition via the regulation of Akt and ERK phosphorylation in the diabetic heart. Collectively, these results strongly indicate that Myr exerts cardioprotective effects against DCM through the blockage of inflammation, oxidative stress, and apoptosis. This suggests that Myr might be a potential therapeutic agent for the treatment of DCM. PMID:28287141

[Phloretin induces apoptosis of BEL-7402 cells in vitro].

PubMed

Luo, Hui; Wang, Ya-jun; Chen, Jie; Liu, Jiang-qin; Zhang, Hai-tao

2008-07-01

To examine the effect of phloretin on apoptosis of BEL-7402 cells. The viability changes of BEL- 7402 cells as a result of phloretin-induced toxicity were analyzed using MTT assay, and the cell morphology changes were observed with fluorescence microscope. Flow cytometry was used to analyze the cell cycle and mitochondrial membrane potential changes, and chromogenic substrate assay performed to detect caspase activity. Phloretin induced obvious cytotoxicity against BEL-7402 cells with IC50 of 89.23 microg/mL. The growth curve demonstrated decreased growth of the cells as phloretin concentration increased. Cell apoptosis occurred 24 h after treatment with 40-160 microg/mL phloretin. Morphological, the cells exposed to phloretin exhibited nuclear chromatin condensation and increased fluorescence intensity. The activity of caspase-9 reached the peak level 12 h after phloretin exposure, and leak levels of caspase-6 and caspase-3 activities occurred 18 and 24 h after the exposure, respectively. Phloretin can induce BEL-7402 cell apoptosis though the mitochondrial pathway.

Thymoquinone Augments Cisplatin-Induced Apoptosis on Esophageal Carcinoma Through Mitigating the Activation of JAK2/STAT3 Pathway.

PubMed

Hu, Xue; Ma, Jingjing; Vikash, Vikash; Li, Jiao; Wu, Dandan; Liu, Ya; Zhang, Jixiang; Dong, Weiguo

2018-01-01

Thymoquinone (TQ) is the major constituent of Nigella sativa seed and has shown biological activity in various human carcinomas. However, few studies have reported its effect on esophageal carcinoma (EC). To explore the chemosensitive effect and mechanism of TQ in augmentation of cisplatin (DDP)-induced apoptosis of EC, both in vitro and in vivo. The viability and apoptosis of esophageal carcinoma cells were detected by the Cell Counting Kit-8 assay, flow cytometry, and Hoechst 33258 staining. The expression levels of JAK2, p-JAK2, STAT3, p-STAT3, Bax, Bcl-2, Cyclin D1, Survivin, and caspase-3, 7, 9 were evaluated by western blot analysis. The histological changes were examined by TUNEL technique and immunohistochemical analysis. TQ enhanced the proapoptotic effect of DDP in human esophageal carcinoma cell line Eca-109, while blocking the activation of JAK2/STAT3 signaling pathway. The apoptosis of esophageal carcinoma cells was induced via blocking the activation of JAK2/STAT3 by using a molecular inhibitor (WP1066). Consistent with the in vivo and in vitro results, TQ increased cellular apoptosis and enriched the chemosensitivity of DDP. TQ along with DDP may regulate the progression of EC and has potential to be a chemotherapeutic agent in EC.

Caspase-8-mediated intracellular acidification precedes mitochondrial dysfunction in somatostatin-induced apoptosis.

PubMed

Liu, D; Martino, G; Thangaraju, M; Sharma, M; Halwani, F; Shen, S H; Patel, Y C; Srikant, C B

2000-03-31

Activation of initiator and effector caspases, mitochondrial changes involving a reduction in its membrane potential and release of cytochrome c (cyt c) into the cytosol, are characteristic features of apoptosis. These changes are associated with cell acidification in some models of apoptosis. The hierarchical relationship between these events has, however, not been deciphered. We have shown that somatostatin (SST), acting via the Src homology 2 bearing tyrosine phosphatase SHP-1, exerts cytotoxic action in MCF-7 cells, and triggers cell acidification and apoptosis. We investigated the temporal sequence of apoptotic events linking caspase activation, acidification, and mitochondrial dysfunction in this system and report here that (i) SHP-1-mediated caspase-8 activation is required for SST-induced decrease in pH(i). (ii) Effector caspases are induced only when there is concomitant acidification. (iii) Decrease in pH(i) is necessary to induce reduction in mitochondrial membrane potential, cyt c release and caspase-9 activation and (iv) depletion of ATP ablates SST-induced cyt c release and caspase-9 activation, but not its ability to induce effector caspases and apoptosis. These data reveal that SHP-1-/caspase-8-mediated acidification occurs at a site other than the mitochondrion and that SST-induced apoptosis is not dependent on disruption of mitochondrial function and caspase-9 activation.

Physcion induces mitochondria-driven apoptosis in colorectal cancer cells via downregulating EMMPRIN.

PubMed

Chen, Xuehong; Gao, Hui; Han, Yantao; Ye, Junli; Xie, Jing; Wang, Chunbo

2015-10-05

Physcion, an anthraquinone derivative widely isolated and characterized from both terrestrial and marine sources, has anti-tumor effects on a variety of carcinoma cells, mainly through inhibition of cell proliferation, apoptosis induction and cell cycle arrest. However, little is known about the mechanisms underlying its role in tumor progression. In the present study, we investigated the molecular mechanisms involved in physcion-induced apoptosis in human colorectal cancer (CRC) lines HCT116. Our results showed that physcion inhibited tumor cell viability in a dose- and time-dependent manner, and induced cell apoptosis via intrinsic mitochondrial pathway. Our results also revealed that physcion treatment significantly inhibited extracelluar matrix metalloproteinase inducer (EMMPRIN) expression in HCT116 cells in a dose-dependent manner and overexpression of EMMPRIN protein markedly reduced physcion-induced cell apoptosis. Furthermore, our results strongly indicated the modulating effect of physcion on EMMPRIN is correlated with AMP-activated protein kinase (AMPK)/Hypoxia-inducible factor 1α (HIF-1α) signaling pathway. Our data provide the first experimental evidence that physcion induces mitochondrial apoptosis in CRC cells by downregulating of EMMPRIN via AMPK/HIF-1α signaling pathway and suggest a new mechanism to explain its anti-tumor effects. Copyright © 2015 Elsevier B.V. All rights reserved.

(+)-Grandifloracin, an antiausterity agent, induces autophagic PANC-1 pancreatic cancer cell death.

PubMed

Ueda, Jun-ya; Athikomkulchai, Sirivan; Miyatake, Ryuta; Saiki, Ikuo; Esumi, Hiroyasu; Awale, Suresh

2014-01-01

Human pancreatic tumors are known to be highly resistant to nutrient starvation, and this prolongs their survival in the hypovascular (austere) tumor microenvironment. Agents that retard this tolerance to nutrient starvation represent a novel antiausterity strategy in anticancer drug discovery. (+)-Grandifloracin (GF), isolated from Uvaria dac, has shown preferential toxicity to PANC-1 human pancreatic cancer cells under nutrient starvation, with a PC50 value of 14.5 μM. However, the underlying mechanism is not clear. In this study, GF was found to preferentially induce PANC-1 cell death in a nutrient-deprived medium via hyperactivation of autophagy, as evidenced by a dramatic upregulation of microtubule-associated protein 1 light chain 3. No change was observed in expression of the caspase-3 and Bcl-2 apoptosis marker proteins. GF was also found to strongly inhibit the activation of Akt, a key regulator of cancer cell survival and proliferation. Because pancreatic tumors are highly resistant to current therapies that induce apoptosis, the alternative cell death mechanism exhibited by GF provides a novel therapeutic insight into antiausterity drug candidates.

Caspase-responsive smart gadolinium-based contrast agent for magnetic resonance imaging of drug-induced apoptosis.

PubMed

Ye, Deju; Shuhendler, Adam J; Pandit, Prachi; Brewer, Kimberly D; Tee, Sui Seng; Cui, Lina; Tikhomirov, Grigory; Rutt, Brian; Rao, Jianghong

2014-10-01

Non-invasive detection of caspase-3/7 activity in vivo has provided invaluable predictive information regarding tumor therapeutic efficacy and anti-tumor drug selection. Although a number of caspase-3/7 targeted fluorescence and positron emission tomography (PET) imaging probes have been developed, there is still a lack of gadolinium (Gd)-based magnetic resonance imaging (MRI) probes that enable high spatial resolution detection of caspase-3/7 activity in vivo . Here we employ a self-assembly approach and develop a caspase-3/7 activatable Gd-based MRI probe for monitoring tumor apoptosis in mice. Upon reduction and caspase-3/7 activation, the caspase-sensitive nano-aggregation MR probe (C-SNAM: 1 ) undergoes biocompatible intramolecular cyclization and subsequent self-assembly into Gd-nanoparticles (GdNPs). This results in enhanced r 1 relaxivity-19.0 (post-activation) vs. 10.2 mM -1 s -1 (pre-activation) at 1 T in solution-and prolonged accumulation in chemotherapy-induced apoptotic cells and tumors that express active caspase-3/7. We demonstrate that C-SNAM reports caspase-3/7 activity by generating a significantly brighter T 1 -weighted MR signal compared to non-treated tumors following intravenous administration of C-SNAM, providing great potential for high-resolution imaging of tumor apoptosis in vivo .

Caspase-3 mediated release of SAC domain containing fragment from Par-4 is necessary for the sphingosine-induced apoptosis in Jurkat cells

PubMed Central

2013-01-01

Background Prostate apoptosis response-4 (Par-4) is a tumor-suppressor protein that selectively activates and induces apoptosis in cancer cells, but not in normal cells. The cancer specific pro-apoptotic function of Par-4 is encoded in its centrally located SAC (Selective for Apoptosis induction in Cancer cells) domain (amino acids 137–195). The SAC domain itself is capable of nuclear entry, caspase activation, inhibition of NF-κB activity, and induction of apoptosis in cancer cells. However, the precise mechanism(s) of how the SAC domain is released from Par-4, in response to apoptotic stimulation, is not well explored. Results In this study, we demonstrate for the first time that sphingosine (SPH), a member of the sphingolipid family, induces caspase-dependant cleavage of Par-4, leading to the release of SAC domain containing fragment from it. Par-4 is cleaved at the EEPD131G site on incubation with caspase-3 in vitro, and by treating cells with several anti-cancer agents. The caspase-3 mediated cleavage of Par-4 is blocked by addition of the pan-caspase inhibitor z-VAD-fmk, caspase-3 specific inhibitor Ac-DEVD-CHO, and by introduction of alanine substitution for D131 residue. Moreover, suppression of SPH-induced Akt dephosphorylation also abrogated the caspase dependant cleavage of Par-4. Conclusion Evidence provided here shows that Par-4 is cleaved by caspase-3 during SPH-induced apoptosis. Cleavage of Par-4 leads to the generation of SAC domain containing fragment which may possibly be essential and sufficient to induce or augment apoptosis in cancer cells. PMID:23442976

Ap4A induces apoptosis in human cultured cells.

PubMed

Vartanian, A; Alexandrov, I; Prudowski, I; McLennan, A; Kisselev, L

1999-07-30

Diadenosine oligophosphates (Ap(n)A) have been proposed as intracellular and extracellular signaling molecules in animal cells. The ratio of diadenosine 5',5'''-P1,P3-triphosphate to diadenosine 5',5'''-P1,P4-tetraphosphate (Ap3A/Ap4A) is sensitive to the cellular status and alters when cultured cells undergo differentiation or are treated with interferons. In cells undergoing apoptosis induced by DNA topoisomerase II inhibitor VP16, the concentration of Ap3A decreases significantly while that of Ap4A increases. Here, we have examined the effects of exogenously added Ap3A and Ap4A on apoptosis and morphological differentiation. Penetration of Ap(n)A into cells was achieved by cold shock. Ap4A at 10 microM induced programmed cell death in human HL60, U937 and Jurkat cells and mouse VMRO cells and this effect appeared to require Ap4A breakdown as hydrolysis-resistant analogues of Ap4A were inactive. On its own, Ap3A induced neither apoptosis nor cell differentiation but did display strong synergism with the protein kinase C activators 12-deoxyphorbol-13-O-phenylacetate and 12-deoxyphorbol-13-O-phenylacetate-20-acetate in inducing differentiation of HL60 cells. We propose that Ap4A and Ap3A are physiological antagonists in determination of the cellular status: Ap4A induces apoptosis whereas Ap3A is a co-inductor of differentiation. In both cases, the mechanism of signal transduction remains unknown.

Arsenic-induced alteration in intracellular calcium homeostasis induces head kidney macrophage apoptosis involving the activation of calpain-2 and ERK in Clarias batrachus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Banerjee, Chaitali; Goswami, Ramansu; Centre for Environmental Studies, Visva-Bharati University, Santiniketan 731 235

2011-10-01

We had earlier shown that exposure to arsenic (0.50 {mu}M) caused caspase-3 mediated head kidney macrophage (HKM) apoptosis involving the p38-JNK pathway in Clarias batrachus. Here we examined the roles of calcium (Ca{sup 2+}) and extra-cellular signal-regulated protein kinase (ERK), the other member of MAPK-pathway on arsenic-induced HKM apoptosis. Arsenic-induced HKM apoptosis involved increased expression of ERK and calpain-2. Nifedipine, verapamil and EGTA pre-treatment inhibited the activation of calpain-2, ERK and reduced arsenic-induced HKM apoptosis as evidenced from reduced caspase-3 activity, Annexin V-FITC-propidium iodide and Hoechst 33342 staining. Pre-incubation with ERK inhibitor U 0126 inhibited the activation of calpain-2 andmore » interfered with arsenic-induced HKM apoptosis. Additionally, pre-incubation with calpain-2 inhibitor also interfered with the activation of ERK and inhibited arsenic-induced HKM apoptosis. The NADPH oxidase inhibitor apocynin and diphenyleneiodonium chloride also inhibited ERK activation indicating activation of ERK in arsenic-exposed HKM also depends on signals from NADPH oxidase pathway. Our study demonstrates the critical role of Ca{sup 2+} homeostasis on arsenic-induced HKM apoptosis. We suggest that arsenic-induced alteration in intracellular Ca{sup 2+} levels initiates pro-apoptotic ERK and calpain-2; the two pathways influence each other positively and induce caspase-3 mediated HKM apoptosis. Besides, our study also indicates the role of ROS in the activation of ERK pathway in arsenic-induced HKM apoptosis in C. batrachus. - Highlights: > Altered Ca{sup 2+} homeostasis leads to arsenic-induced HKM apoptosis. > Calpain-2 plays a critical role in the process. > ERK is pro-apoptotic in arsenic-induced HKM apoptosis. > Arsenic-induced HKM apoptosis involves cross talk between calpain-2 and ERK.« less

DNA Tetrahedron Delivery Enhances Doxorubicin-Induced Apoptosis of HT-29 Colon Cancer Cells

NASA Astrophysics Data System (ADS)

Zhang, Guiyu; Zhang, Zhiyong; Yang, Junen

2017-08-01

As a nano-sized drug carrier with the advantage of modifiability and proper biocompatibility, DNA tetrahedron (DNA tetra) delivery is hopeful to enhance the inhibitory efficiency of nontargeted anticancer drugs. In this investigation, doxorubicin (Dox) was assembled to a folic acid-modified DNA tetra via click chemistry to prepare a targeted antitumor agent. Cellular uptake efficiency was measured via fluorescent imaging. Cytotoxicity, inhibition efficiency, and corresponding mechanism on colon cancer cell line HT-29 were evaluated by MTT assay, cell proliferation curve, western blot, and flow cytometry. No cytotoxicity was induced by DNA tetra, but the cellular uptake ratio increased obviously resulting from the DNA tetra-facilitated penetration through cellular membrane. Accordingly, folic acid-DNA tetra-Dox markedly increased the antitumor efficiency with increased apoptosis levels. In details, 100 μM was the effective concentration and a 6-h incubation period was needed for apoptosis induction. In conclusion, nano-sized DNA tetrahedron was a safe and effective delivery system for Dox and correspondingly enhanced the anticancer efficiency.

Edaravone protects against hyperosmolarity-induced oxidative stress and apoptosis in primary human corneal epithelial cells.

PubMed

Li, Yanwei; Liu, Haifeng; Zeng, Wei; Wei, Jing

2017-01-01

An increase in the osmolarity of tears induced by excessive evaporation of the aqueous tear phase is a major pathological mechanism behind dry eye. Exposure of epithelial cells on the surface of the human eye to hyperosmolarity leads to oxidative stress, mitochondrial dysfunction, and apoptosis. Edaravone, a hydroxyl radical scavenging agent, is clinically used to reduce neuronal damage following ischemic stroke. In this study, we found that treatment with hyperosmotic media at 400 and 450 mOsM increased the levels of ROS and mitochondrial oxidative damage, which were ameliorated by edaravone treatment in a dose-dependent manner. We also found that edaravone could improve mitochondrial function in HCEpiCs by increasing the levels of ATP and mitochondrial membrane potential. MTT and LDH assays indicated that edaravone could attenuate hyperosmolarity-induced cell death. It was found that edaravone prevented apoptosis by decreasing the level of cleaved caspase-3, and attenuating the release of cytochrome C. Mechanistically, we found that edaravone augmented the expression of Nrf2 and its target genes, such as HO-1, GPx-1, and GCLC.

Edaravone protects against hyperosmolarity-induced oxidative stress and apoptosis in primary human corneal epithelial cells

PubMed Central

Li, Yanwei; Liu, Haifeng; Zeng, Wei; Wei, Jing

2017-01-01

An increase in the osmolarity of tears induced by excessive evaporation of the aqueous tear phase is a major pathological mechanism behind dry eye. Exposure of epithelial cells on the surface of the human eye to hyperosmolarity leads to oxidative stress, mitochondrial dysfunction, and apoptosis. Edaravone, a hydroxyl radical scavenging agent, is clinically used to reduce neuronal damage following ischemic stroke. In this study, we found that treatment with hyperosmotic media at 400 and 450 mOsM increased the levels of ROS and mitochondrial oxidative damage, which were ameliorated by edaravone treatment in a dose-dependent manner. We also found that edaravone could improve mitochondrial function in HCEpiCs by increasing the levels of ATP and mitochondrial membrane potential. MTT and LDH assays indicated that edaravone could attenuate hyperosmolarity-induced cell death. It was found that edaravone prevented apoptosis by decreasing the level of cleaved caspase-3, and attenuating the release of cytochrome C. Mechanistically, we found that edaravone augmented the expression of Nrf2 and its target genes, such as HO-1, GPx-1, and GCLC. PMID:28346481

Pharbilignan C induces apoptosis through a mitochondria-mediated intrinsic pathway in human breast cancer cells.

PubMed

Park, Yong Joo; Choi, Chang-Ik; Chung, Kyu Hyuck; Kim, Ki Hyun

2016-10-01

Pharbitidis Semen, the seed of Morning glory (Pharbitis nil), is a medicinal agent that has traditionally been used as a purgative in Korea. Pharbilignan C (PLC) is a dihydro[b]-benzofuran-type neolignan from Pharbitidis Semen, which reportedly exhibited the most potent cytotoxicity against human tumor cells. To further study the antiproliferative activity of PLC, its molecular mechanisms of action in two breast adenocarcinoma cells, MCF-7 and MDA-MB 231 cells were investigated. PLC inhibited the proliferation of MDA-MB 231 and MCF-7 cells, in order of sensitivity (IC50 of MDA-MB 231 cells: 7.0±2.0μM). PLC induced apoptosis in MDA-MB 231 cells with down regulation of Bcl-2 and up-regulation of Bax expression. It also decreased mitochondrial membrane potential accompanied with increasing initiator caspase, caspase-9 activation and executioner caspase, caspase-3 activation. This study demonstrates that PLC inhibited proliferation of MDA-MB 231 cells by inducing apoptosis via the mitochondria-mediated intrinsic pathway. Copyright © 2016 Elsevier Ltd. All rights reserved.

CHEMOSENSITIZATION BY A NON-APOPTOGENIC HEAT SHOCK PROTEIN 70-BINDING APOPTOSIS INDUCING FACTOR MUTANT

EPA Science Inventory

Chemosensitization by a non-apoptogenic heat shock protein 70-binding apoptosis inducing factor mutant

Abstract
HSP70 inhibits apoptosis by neutralizing the caspase activator Apaf-1 and by interacting with apoptosis inducing factor (AIF), a mitochondrial flavoprotein wh...

Curcumin derivative WZ35 efficiently suppresses colon cancer progression through inducing ROS production and ER stress-dependent apoptosis.

PubMed

Zhang, Junru; Feng, Zhiguo; Wang, Chunhua; Zhou, Huiping; Liu, Weidong; Kanchana, Karvannan; Dai, Xuanxuan; Zou, Peng; Gu, Junlian; Cai, Lu; Liang, Guang

2017-01-01

Colon cancer is characterized by its fast progression and poor prognosis, and novel agents of treating colon cancer are urgently needed. WZ35, a synthetic curcumin derivative, has been reported to exhibit promising antitumor activity. Here, we investigated the in vitro and in vivo activities of WZ35 and explored the underlying mechanisms in colon cancer cell lines. WZ35 treatment significantly decreased the cell viability associated with G2/M cell cycle arrest and apoptosis induction in colon cancer cell lines. We also show that WZ35 is highly effective in inhibiting tumor growth in a CT26 xenograft mouse model. Mechanistically, WZ35 treatment significantly induced reactive oxygen species (ROS) generation and endoplasmic reticulum (ER) stress in CT26 cells. Abrogation of ROS production by N-acetylcysteine (NAC) co-treatment almost totally reversed the WZ35-induced cell apoptosis and ER stress activation. Inhibition of p-PERK by GSK2606414 can significantly reverse WZ35-induced cell apoptosis in CT26 cells. Taken together, the curcumin derivative WZ35 exhibited anti-tumor effects in colon cancer cells both in vitro and in vivo, via a ROS-ER stress-mediated mechanism. These findings indicate that activating ROS generation could be an important strategy for the treatment of colon cancers.

Nocardia cyriacigeogica from Bovine Mastitis Induced In vitro Apoptosis of Bovine Mammary Epithelial Cells via Activation of Mitochondrial-Caspase Pathway.

PubMed

Chen, Wei; Liu, Yongxia; Zhang, Limei; Gu, Xiaolong; Liu, Gang; Shahid, Muhammad; Gao, Jian; Ali, Tariq; Han, Bo

2017-01-01

Nocardia is one of the causing agents of bovine mastitis and increasing prevalence of nocardial mastitis in shape of serious outbreaks has been reported from many countries. However, the mechanisms by which this pathogen damages the bovine mammary epithelial cells (bMECs) is not yet studied. Therefore, this study was designed with the aim to evaluate the apoptotic effects elicited by Nocardia and to investigate the pathway by which the Nocardia induce apoptosis in bMECs. Clinical Nocardia cyriacigeorgica strain from bovine mastitis was used to infect the bMECs for different time intervals, viz . 1, 3, 6, 12, and 18 h, and then the induced effects on bMECs were studied using adhesion and invasion assays, release of lactate dehydrogenase (LDH), apoptosis analysis by annexin V and propidium iodide (PI) double staining, morphological, and ultrastructural observations under scanning electron microscope (SEM) and transmission electron microscope (TEM), mitochondrial transmembrane potential (ΔΨm) assay using flow cytometry, and the protein quantification of mitochondrial cytochrome c and caspase-9 and caspase-3 by western blotting. The results of this study showed that N. cyriacigeorgica possessed the abilities of adhesion and invasion to bMECs. N. cyriacigeorgica was found to collapse mitochondrial transmembrane potential, significantly ( p < 0.05) release mitochondrial cytochrome c and ultimately induce cell apoptosis. Additionally, it promoted casepase-9 ( p < 0.01) and casepase-3 ( p < 0.05) levels, significantly ( p < 0.01) increased the release of LDH and promoted DNA fragmentation which further confirmed the apoptosis. Furthermore, N. cyriacigeorgica induced apoptosis/necrosis manifested specific ultrastructure features under TEM, such as swollen endoplasmic reticulum, cristae degeneration, and swelling of mitochondria, vesicle formation on the cell surface, rupturing of cell membrane and nuclear membrane, clumping, fragmentation, and margination of chromatin

Disruption of Redox Homeostasis in Tumor Necrosis Factor-Induced Apoptosis in a Murine Hepatocyte Cell Line

PubMed Central

Pierce, Robert H.; Campbell, Jean S.; Stephenson, Alyssa B.; Franklin, Christopher C.; Chaisson, Michelle; Poot, Martin; Kavanagh, Terrance J.; Rabinovitch, Peter S.; Fausto, Nelson

2000-01-01

Tumor necrosis factor (TNF) is a mediator of the acute phase response in the liver and can initiate proliferation and cause cell death in hepatocytes. We investigated the mechanisms by which TNF causes apoptosis in hepatocytes focusing on the role of oxidative stress, antioxidant defenses, and mitochondrial damage. The studies were conducted in cultured AML12 cells, a line of differentiated murine hepatocytes. As is the case for hepatocytes in vivo, AML12 cells were not sensitive to cell death by TNF alone, but died by apoptosis when exposed to TNF and a small dose of actinomycin D (Act D). Morphological signs of apoptosis were not detected until 6 hours after the treatment and by 18 hours ∼50% of the cells had died. Exposure of the cells to TNF+Act D did not block NFκB nuclear translocation, DNA binding, or its overall transactivation capacity. Induction of apoptosis was characterized by oxidative stress indicated by the loss of NAD(P)H and glutathione followed by mitochondrial damage that included loss of mitochondrial membrane potential, inner membrane structural damage, and mitochondrial condensation. These changes coincided with cytochrome C release and the activation of caspases-8, -9, and -3. TNF-induced apoptosis was dependent on glutathione levels. In cells with decreased levels of glutathione, TNF by itself in the absence of transcriptional blocking acted as an apoptotic agent. Conversely, the antioxidant α-lipoic acid, that protected against the loss of glutathione in cells exposed to TNF+Act D completely prevented mitochondrial damage, caspase activation, cytochrome C release, and apoptosis. The results demonstrate that apoptosis induced by TNF+Act D in AML12 cells involves oxidative injury and mitochondrial damage. As injury was regulated to a larger extent by the glutathione content of the cells, we suggest that the combination of TNF+Act D causes apoptosis because Act D blocks the transcription of genes required for antioxidant defenses. PMID

Low-power laser irradiation inhibits amyloid beta-induced cell apoptosis

NASA Astrophysics Data System (ADS)

Zhang, Heng; Wu, Shengnan

2011-03-01

The deposition and accumulation of amyloid-β-peptide (Aβ) in the brain are considered a pathological hallmark of Alzheimer's disease(AD). Apoptosis is a contributing pathophysiological mechanism of AD. Low-power laser irradiation (LPLI), a non-damage physical therapy, which has been used clinically for decades of years, is shown to promote cell proliferation and prevent apoptosis. Recently, low-power laser irradiation (LPLI) has been applied to moderate AD. In this study, Rat pheochromocytoma (PC12) cells were treated with amyloid beta 25-35 (Aβ25-35) for induction of apoptosis before LPLI treatment. We measured cell viability with CCK-8 according to the manufacture's protocol, the cell viability assays show that low fluence of LPLI (2 J/cm2 ) could inhibit the cells apoptosis. Then using statistical analysis of proportion of apoptotic cells by flow cytometry based on Annexin V-FITC/PI, the assays also reveal that low fluence of LPLI (2 J/cm2 ) could inhibit the Aβ-induced cell apoptosis. Taken together, we demonstrated that low fluence of LPLI (2 J/cm2 ) could inhibit the Aβ-induced cell apoptosis, these results directly point to a therapeutic strategy for the treatment of AD through LPLI.

Design, synthesis, and biological evaluation of (2E)-(2-oxo-1, 2-dihydro-3H-indol-3-ylidene)acetate derivatives as anti-proliferative agents through ROS-induced cell apoptosis.

PubMed

Song, Zhuang; Chen, Cai-Ping; Liu, Jun; Wen, Xiaoan; Sun, Hongbin; Yuan, Haoliang

2016-11-29

A novel class of (2E)-(2-oxo-1, 2-dihydro-3H-indol-3-ylidene)acetate derivatives were designed and synthesized as potent anti-proliferative agents. Most of these compounds showed potent anti-proliferative activity against some tumor cell lines, including SK-BR-3, MDA-MB-231, HCT-116, SW480, Ovcar-3, HL-60, Saos-2 and HepG2. Compounds 8c and 11h were identified as the most potent ones, while HL-60, HCT116 and MDA-MB-231 were the most sensitive cell lines. Mechanistic study revealed that compound 8c enhanced reactive oxygen species level by inhibiting TrxR and then induced apoptosis by activating apoptosis proteins, bax and cleaved-caspase 3 in HCT116 cells. Preliminary SAR analysis indicated that modifications of the double bond and ester group made great effects on the anti-proliferative activity. Our findings suggested that it was worth further studies on the antitumor potency of (2E)-(2-oxo-1, 2-dihydro-3H-indol-3-ylidene)acetates. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Cathepsin B is involved in the heat shock induced cardiomyocytes apoptosis as well as the anti-apoptosis effect of HSP-70.

PubMed

Hsu, Shu-Fen; Hsu, Chuan-Chih; Cheng, Bor-Chih; Lin, Cheng-Hsien

2014-11-01

Cathepsin B is one of the major lysosomal cysteine proteases that plays an important role in apoptosis. Herein, we investigated whether Cathepsin B is involved in cardiomyocyte apoptosis caused by hyperthermic injury (HI) and heat shock protein (HSP)-70 protects these cells from HI-induced apoptosis mediated by Cathepsin. HI was produced in H9C2 cells by putting them in a circulating 43 °C water bath for 120 min, whereas preinduction of HSP-70 was produced in H9C2 cells by mild heat preconditioning (or putting them in 42 °C water bath for 30 min) 8 h before the start of HI. It was found that HI caused both cardiomyocyte apoptosis and increased Cathepsin B activity in H9C2 cells. E-64-c, in addition to reducing Cathepsin B activity, significantly attenuated HI-induced cardiomyocyte apoptosis (evidenced by increased apoptotic cell numbers, increased tuncated Bid (t-Bid), increased cytochrome C, increased caspase-9/-3, and decreased Bcl-2/Bax) in H9C2 cells. In addition, preinduction of HSP-70 by mild heat preconditioning or inhibition of HSP-70 by Tripolide significantly attenuated or exacerbated respectively both the cardiomyocyte apoptosis and increased Cathepsin B activity in H9C2 cells. Furthermore, the beneficial effects of pre-induction of HSP-70 by mild heat production in reducing both cardiomyocyte apoptosis and increased Cathepsin B activity caused by HI can be significantly reduced by Triptolide preconditioning. These results indicate that Cathepsin B is involved in HI-induced cardiomyocyte apoptosis in H9C2 cells and HSP-70 protects these cells from HI-induced cardiomyocyte apoptosis through Cathepsin B pathways.

A hybrid of coumarin and phenylsulfonylfuroxan induces caspase-dependent apoptosis and cytoprotective autophagy in lung adenocarcinoma cells.

PubMed

Wang, Qian; Guo, Yalan; Jiang, Shanshan; Dong, Mengxue; Kuerban, Kudelaidi; Li, Jiyang; Feng, Meiqing; Chen, Ying; Ye, Li

2018-01-15

Lung adenocarcinoma is the most primary histologic subtype of non-small cell lung cancer (NSCLC). Compound 8b, a novel coumarin derivative with phenylsulfonylfuroxan group, shows significant antiproliferation activity against lung adenocarcinoma cell with low toxicity. This study aims to uncover the potential of compound 8b in relation to apoptosis as well as autophagy induction in lung adenocarcinoma cells. The cytotoxicity and apoptosis of A549 and H1299 cells induced by compound 8b were detected by MTT, microscope and western blot analysis. Autophagy was determined by TEM, confocal microscopy and western blot analysis. Akt/mTOR and Erk signaling pathway were also examined by western blot analysis. First, significant growth inhibition and caspase-dependent apoptosis were observed in compound 8b-treated A549 and H1299 cells. Then, we confirmed compound 8b-induced autophagy by autophagosomes formation, upregulated expression of autophagy-related protein LC3-II and autophagic flux. Importantly, abolishing autophagy using inhibitors and ATG5 siRNA enhanced the cytotoxicity of compound 8b, indicating the cytoprotective role of autophagy in lung adenocarcinoma. Further mechanistic investigations suggested that Akt/mTOR and Erk signaling pathways contributed to autophagy induction by compound 8b. This results demonstrate that compound 8b induces caspase-dependent apoptosis as well as cytoprotective autophagy in lung adenocarcinoma cells, which may provide scientific evidence for developing this furoxan-based NO-releasing coumarin derivative as a potential anti-lung adenocarcinoma therapeutic agents. Copyright © 2017 Elsevier GmbH. All rights reserved.

Berberine induces apoptosis via ROS generation in PANC-1 and MIA-PaCa2 pancreatic cell lines.

PubMed

Park, S H; Sung, J H; Kim, E J; Chung, N

2015-02-01

Pancreatic cancer is the fourth leading cause of cancer death. Gemcitabine is widely used as a chemotherapeutic agent for the treatment of pancreatic cancer, but the prognosis is still poor. Berberine, an isoquinoline alkaloid extracted from a variety of natural herbs, possesses a variety of pharmacological properties including anticancer effects. In this study, we investigated the anticancer effects of berberine and compared its use with that of gemcitabine in the pancreatic cancer cell lines PANC-1 and MIA-PaCa2. Berberine inhibited cell growth in a dose-dependent manner by inducing cell cycle arrest and apoptosis. After berberine treatment, the G1 phase of PANC-1 cells increased by 10% compared to control cells, and the G1 phase of MIA-PaCa2 cells was increased by 2%. Whereas gemcitabine exerts antiproliferation effects through S-phase arrest, our results showed that berberine inhibited proliferation by inducing G1-phase arrest. Berberine-induced apoptosis of PANC-1 and MIA-PaCa2 cells increased by 7 and 2% compared to control cells, respectively. Notably, berberine had a greater apoptotic effect in PANC-1 cells than gemcitabine. Upon treatment of PANC-1 and MIA-PaCa2 with berberine at a half-maximal inhibitory concentration (IC50), apoptosis was induced by a mechanism that involved the production of reactive oxygen species (ROS) rather than caspase 3/7 activation. Our findings showed that berberine had anti-cancer effects and may be an effective drug for pancreatic cancer chemotherapy.

Dietary flavonoid fisetin regulates aluminium chloride-induced neuronal apoptosis in cortex and hippocampus of mice brain.

PubMed

Prakash, Dharmalingam; Sudhandiran, Ganapasam

2015-12-01

Dietary flavonoids have been suggested to promote brain health by protecting brain parenchymal cells. Recently, understanding the possible mechanism underlying neuroprotective efficacy of flavonoids is of great interest. Given that fisetin exerts neuroprotection, we have examined the mechanisms underlying fisetin in regulating Aβ aggregation and neuronal apoptosis induced by aluminium chloride (AlCl3) administration in vivo. Male Swiss albino mice were induced orally with AlCl3 (200 mg/kg. b.wt./day/8 weeks). Fisetin (15 mg/Kg. b.wt. orally) was administered for 4 weeks before AlCl3-induction and administered simultaneously for 8 weeks during AlCl3-induction. We found aggregation of Amyloid beta (Aβ 40-42), elevated expressions of Apoptosis stimulating kinase (ASK-1), p-JNK (c-Jun N-terminal Kinase), p53, cytochrome c, caspases-9 and 3, with altered Bax/Bcl-2 ratio in favour of apoptosis in cortex and hippocampus of AlCl3-administered mice. Furthermore, TUNEL and fluoro-jade C staining demonstrate neurodegeneration in cortex and hippocampus. Notably, treatment with fisetin significantly (P<0.05) reduced Aβ aggregation, ASK-1, p-JNK, p53, cytochrome c, caspase-9 and 3 protein expressions and modulated Bax/Bcl-2 ratio. TUNEL-positive and fluoro-jade C stained cells were also significantly reduced upon fisetin treatment. We have identified the involvement of fisetin in regulating ASK-1 and p-JNK as possible mediator of Aβ aggregation and subsequent neuronal apoptosis during AlCl3-induced neurodegeneration. These findings define the possibility that fisetin may slow or prevent neurodegneration and can be utilised as neuroprotective agent against Alzheimer's and Parkinson's disease. Copyright © 2015 Elsevier Inc. All rights reserved.

Activation of human herpesvirus replication by apoptosis.

PubMed

Prasad, Alka; Remick, Jill; Zeichner, Steven L

2013-10-01

A central feature of herpesvirus biology is the ability of herpesviruses to remain latent within host cells. Classically, exposure to inducing agents, like activating cytokines or phorbol esters that stimulate host cell signal transduction events, and epigenetic agents (e.g., butyrate) was thought to end latency. We recently showed that Kaposi's sarcoma-associated herpesvirus (KSHV, or human herpesvirus-8 [HHV-8]) has another, alternative emergency escape replication pathway that is triggered when KSHV's host cell undergoes apoptosis, characterized by the lack of a requirement for the replication and transcription activator (RTA) protein, accelerated late gene kinetics, and production of virus with decreased infectivity. Caspase-3 is necessary and sufficient to initiate the alternative replication program. HSV-1 was also recently shown to initiate replication in response to host cell apoptosis. These observations suggested that an alternative apoptosis-triggered replication program might be a general feature of herpesvirus biology and that apoptosis-initiated herpesvirus replication may have clinical implications, particularly for herpesviruses that almost universally infect humans. To explore whether an alternative apoptosis-initiated replication program is a common feature of herpesvirus biology, we studied cell lines latently infected with Epstein-Barr virus/HHV-4, HHV-6A, HHV-6B, HHV-7, and KSHV. We found that apoptosis triggers replication for each HHV studied, with caspase-3 being necessary and sufficient for HHV replication. An alternative apoptosis-initiated replication program appears to be a common feature of HHV biology. We also found that commonly used cytotoxic chemotherapeutic agents activate HHV replication, which suggests that treatments that promote apoptosis may lead to activation of latent herpesviruses, with potential clinical significance.

Activation of Human Herpesvirus Replication by Apoptosis

PubMed Central

Prasad, Alka; Remick, Jill

2013-01-01

A central feature of herpesvirus biology is the ability of herpesviruses to remain latent within host cells. Classically, exposure to inducing agents, like activating cytokines or phorbol esters that stimulate host cell signal transduction events, and epigenetic agents (e.g., butyrate) was thought to end latency. We recently showed that Kaposi's sarcoma-associated herpesvirus (KSHV, or human herpesvirus-8 [HHV-8]) has another, alternative emergency escape replication pathway that is triggered when KSHV's host cell undergoes apoptosis, characterized by the lack of a requirement for the replication and transcription activator (RTA) protein, accelerated late gene kinetics, and production of virus with decreased infectivity. Caspase-3 is necessary and sufficient to initiate the alternative replication program. HSV-1 was also recently shown to initiate replication in response to host cell apoptosis. These observations suggested that an alternative apoptosis-triggered replication program might be a general feature of herpesvirus biology and that apoptosis-initiated herpesvirus replication may have clinical implications, particularly for herpesviruses that almost universally infect humans. To explore whether an alternative apoptosis-initiated replication program is a common feature of herpesvirus biology, we studied cell lines latently infected with Epstein-Barr virus/HHV-4, HHV-6A, HHV-6B, HHV-7, and KSHV. We found that apoptosis triggers replication for each HHV studied, with caspase-3 being necessary and sufficient for HHV replication. An alternative apoptosis-initiated replication program appears to be a common feature of HHV biology. We also found that commonly used cytotoxic chemotherapeutic agents activate HHV replication, which suggests that treatments that promote apoptosis may lead to activation of latent herpesviruses, with potential clinical significance. PMID:23885073

Huaier aqueous extract induces apoptosis of human fibrosarcoma HT1080 cells through the mitochondrial pathway

PubMed Central

CUI, YANG; MENG, HONGMEI; LIU, WEIDONG; WANG, HUAN; LIU, QINGPENG

2015-01-01

In recent years, aqueous extract of Trametes robiniophila Murr. (Huaier), a traditional Chinese medicine, has been frequently used in China for complementary cancer therapy. However, the mechanisms underlying its anticancer effects have yet to be elucidated. The present study aimed to evaluate the ability of Huaier extract to inhibit proliferation, promote apoptosis and suppress mobility in the fibrosarcoma HT1080 cell line in vitro. The cells were treated with gradient doses of Huaier extract at concentrations of 0, 4, 8 or 16 mg/ml for 24, 48 or 72 h. The cell viability and motility were measured in vitro using MTT, invasive, migration and scratch assays. The distribution of the cell cycle and the extent of cellular apoptosis were analyzed by flow cytometry. The apoptotic pathways were detected using a mitochondrial membrane potential transition assay and western blotting. The results revealed that the cellular viability decreased significantly with increasing concentrations of Huaier extract. In addition, cell invasiveness and migration were also suppressed significantly. It was demonstrated that Huaier extract induced G2 cell-cycle arrest and cellular apoptosis in a time- and dose-dependent manner. The decreased mitochondrial membrane potential, the downregulation of B-cell lymphoma 2 and pro-caspase-3, and upregulation of Bcl-2-associated X protein, cleaved caspase-9 and caspase-3 suggested that Huaier extract induced the apoptosis of HT1080 cells through the mitochondrial pathway. The results of the present study indicate that Huaier extract is a potential complementary agent for the treatment of fibrosarcoma. PMID:25789006

Antiproliferative and apoptosis inducing effects of citral via p53 and ROS-induced mitochondrial-mediated apoptosis in human colorectal HCT116 and HT29 cell lines.

PubMed

Sheikh, Bassem Y; Sarker, Md Moklesur Rahman; Kamarudin, Muhamad Noor Alfarizal; Mohan, Gokula

2017-12-01

Despite various anticancer reports, antiproliferative and apoptosis inducing activity of citral in HCT116 and HT29 cells have never been reported. This study aimed to evaluate the cytotoxic and apoptosis inducing effects of citral in colorectal cancer cell lines. The citral-treated cells were subjected to MTT assay followed by flow cytometric Annexin V-FITC/PI, mitochondrial membrane potential and intracellular reactive oxygen species (ROS) determination. The apoptotic proteins expression was investigated by Western blot analysis. Citral inhibited the growth of HCT116 and HT29 cells by dose- and time-dependent manner without inducing cytotoxicity in CCD841-CoN normal colon cells. Flow cytometric analysis showed that citral (50-200μM; 24-48h) induced the externalization of phoshpotidylserine and reduced the mitochondrial membrane potential in HCT116 and HT29 cells. Citral elevated intracellular ROS level while attenuating GSH levels in HCT116 and HT29 cells which were reversed with N-acetycysteine (2mM) pre-treatment indicating that citral induced mitochondrial-mediated apoptosis via augmentation of intracellular ROS. Citral induced the phosphorylation of p53 protein and the expression of Bax while decreasing Bc-2 and Bcl-xL expression which promoted the cleavage of caspase-3. Collectively, our data suggest that citral induced p53 and ROS-mediated mitochondrial-mediated apoptosis in human colorectal cancer HCT116 and HT29 cells. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Albumin-induced apoptosis of tubular cells is modulated by BASP1

PubMed Central

Sanchez-Niño, M D; Fernandez-Fernandez, B; Perez-Gomez, M V; Poveda, J; Sanz, A B; Cannata-Ortiz, P; Ruiz-Ortega, M; Egido, J; Selgas, R; Ortiz, A

2015-01-01

Albuminuria promotes tubular injury and cell death, and is associated with faster progression of chronic kidney disease (CKD) to end-stage renal disease. However, the molecular mechanisms regulating tubular cell death in response to albuminuria are not fully understood. Brain abundant signal protein 1 (BASP1) was recently shown to mediate glucose-induced apoptosis in tubular cells. We have studied the role of BASP1 in albumin-induced tubular cell death. BASP1 expression was studied in experimental puromycin aminonucleoside-induced nephrotic syndrome in rats and in human nephrotic syndrome. The role of BASP1 in albumin-induced apoptosis was studied in cultured human HK2 proximal tubular epithelial cells. Puromycin aminonucleoside induced proteinuria and increased total kidney BASP1 mRNA and protein expression. Immunohistochemistry localized the increased BASP1 to tubular cells. BASP1 expression colocalized with deoxynucleotidyl-transferase-mediated dUTP nick-end labeling staining for apoptotic cells. Increased tubular BASP1 expression was observed in human proteinuric nephropathy by immunohistochemistry, providing evidence for potential clinical relevance. In cultured tubular cells, albumin induced apoptosis and increased BASP1 mRNA and protein expression at 6–48 h. Confocal microscopy localized the increased BASP1 expression in albumin-treated cells mainly to the perinuclear area. A peripheral location near the cell membrane was more conspicuous in albumin-treated apoptotic cells, where it colocalized with actin. Inhibition of BASP1 expression by a BASP1 siRNA protected from albumin-induced apoptosis. In conclusion, albumin-induced apoptosis in tubular cells is BASP1-dependent. This information may be used to design novel therapeutic approaches to slow CKD progression based on protection of tubular cells from the adverse consequences of albuminuria. PMID:25675304

Autophagy regulates chlorpyrifos-induced apoptosis in SH-SY5Y cells.

PubMed

Park, Jae Hyeon; Lee, Jeong Eun; Shin, In Chul; Koh, Hyun Chul

2013-04-01

Recent studies have shown that up-regulation of autophagy may be a tractable therapeutic intervention for clearing disease-causing proteins, including α-synuclein, ubiquitin, and other misfolded or aggregated proteins in pesticide-induced neurodegeneration. In a previous study, we reported that chlorpyrifos (CPF)-induced mitochondria-dependent apoptosis is mediated through reactive oxygen species in SH-SY5Y cells. In this study, we explored a novel pharmacotherapeutic approach to prevent CPF neurotoxicity involving the regulation of autophagy. We investigated the modulation of CPF-induced apoptosis according to autophagy regulation. We found that CPF induced apoptosis in SH-SY5Y cells, as demonstrated by the activation of caspase-3 and nuclear condensation. In addition, we observed that cells treated with CPF underwent autophagic cell death by monitoring the expression of LC3-II and p62. Pretreatment with the autophagy inducer rapamycin significantly enhanced the cell viability of CPF-exposed cells, and the enhancement of cell viability was partially due to alleviation of CPF-induced apoptosis via a decrease in levels of cleaved caspase-3. Specifically, rapamycin pretreatment decreased Bax and increased Bcl-2 expression in mitochondria. In addition, rapamycin significantly decreased cytochrome c release in from mitochondria into the cytosol. However, pretreatment of cells with the autophagy inhibitor, 3-methyladenine (3MA), remarkably increased CPF toxicity in these cells; this with correlated with increased expression of Bax and decreased expression of Bcl-2 in mitochondria. Our results suggest that CPF-induced cytotoxicity is modified by autophagy regulation and that rapamycin protects against CPF-induced apoptosis by enhancing autophagy. Pharmacologic induction of autophagy by rapamycin may be a useful treatment strategy in neurodegenerative disorders. Crown Copyright © 2013. Published by Elsevier Inc. All rights reserved.

Curcumin Induces Apoptosis of Upper Aerodigestive Tract Cancer Cells by Targeting Multiple Pathways

PubMed Central

Amin, A. R. M. Ruhul; Haque, Abedul; Rahman, Mohammad Aminur; Chen, Zhuo Georgia; Khuri, Fadlo Raja; Shin, Dong Moon

2015-01-01

Curcumin, a natural compound isolated from the Indian spice "Haldi" or "curry powder", has been used for centuries as a traditional remedy for many ailments. Recently, the potential use of curcumin in cancer prevention and therapy urges studies to uncover the molecular mechanisms associated with its anti-tumor effects. In the current manuscript, we investigated the mechanism of curcumin-induced apoptosis in upper aerodigestive tract cancer cell lines and showed that curcumin-induced apoptosis is mediated by the modulation of multiple pathways such as induction of p73, and inhibition of p-AKT and Bcl-2. Treatment of cells with curcumin induced both p53 and the related protein p73 in head and neck and lung cancer cell lines. Inactivation of p73 by dominant negative p73 significantly protected cells from curcumin-induced apoptosis, whereas ablation of p53 by shRNA had no effect. Curcumin treatment also strongly inhibited p-AKT and Bcl-2 and overexpression of constitutively active AKT or Bcl-2 significantly inhibited curcumin-induced apoptosis. Taken together, our findings suggest that curcumin-induced apoptosis is mediated via activating tumor suppressor p73 and inhibiting p-AKT and Bcl-2. PMID:25910231

Inhibition of p38 MAP kinase pathway induces apoptosis and prevents Epstein Barr virus reactivation in Raji cells exposed to lytic cycle inducing compounds

PubMed Central

Matusali, Giulia; Arena, Giuseppe; De Leo, Alessandra; Di Renzo, Livia; Mattia, Elena

2009-01-01

Background EBV lytic cycle activators, such as phorbol esters, anti-immunoglobulin, transforming growth factor β (TGFβ), sodium butyrate, induce apoptosis in EBV-negative but not in EBV-positive Burkitt's lymphoma (BL) cells. To investigate the molecular mechanisms allowing EBV-infected cells to be protected, we examined the expression of viral and cellular antiapoptotic proteins as well as the activation of signal transduction pathways in BL-derived Raji cells exposed to lytic cycle inducing agents. Results Our data show that, following EBV activation, the latent membrane protein 1 (LMP1) and the cellular anti-apoptotic proteins MCL-1 and BCL-2 were quickly up-regulated and that Raji cells remained viable even when exposed simultaneously to P(BU)2, sodium butyrate and TGFβ. We report here that inhibition of p38 pathway, during EBV activation, led to a three fold increment of apoptosis and largely prevented lytic gene expression. Conclusion These findings indicate that, during the switch from the latent to the lytic phase of EBV infection, p38 MAPK phosphorylation plays a key role both for protecting the host cells from apoptosis as well as for inducing viral reactivation. Because Raji cells are defective for late antigens expression, we hypothesize that the increment of LMP1 gene expression in the early phases of EBV lytic cycle might contribute to the survival of the EBV-positive cells. PMID:19272151

High glucose induces apoptosis via upregulation of Bim expression in proximal tubule epithelial cells.

PubMed

Zhang, Xiao-Qian; Dong, Jian-Jun; Cai, Tian; Shen, Xue; Zhou, Xiao-Jun; Liao, Lin

2017-04-11

Diabetic nephropathy is the primary cause of end-stage renal disease. Apoptosis of tubule epithelial cells is a major feature of diabetic nephropathy. The mechanisms of high glucose (HG) induced apoptosis are not fully understood. Here we demonstrated that, HG induced apoptosis via upregulating the expression of proapoptotic Bcl-2 homology domain 3 (BH3)-only protein Bim protein, but not bring a significant change in the baseline level of autophagy in HK2 cells. The increase of Bim expression was caused by the ugregulation of transcription factors, FOXO1 and FOXO3a. Bim expression initiates BAX/BAK-mediated mitochondria-dependent apoptosis. Silence of Bim by siRNA in HK2 cells prevented HG-induced apoptosis and also sensitized HK2 cells to autophagy during HG treatment. The autophagy inhibitor 3-MA increased the injury in Bim knockdown HK2 cells by retriggering apoptosis. The above results suggest a Bim-independent apoptosis pathway in HK2 cells, which normally could be inhibited by autophagy. Overall, our results indicate that HG induces apoptosis via up-regulation of Bim expression in proximal tubule epithelial cells.

Inhibition of autophagy enhances DNA damage-induced apoptosis by disrupting CHK1-dependent S phase arrest

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liou, Jong-Shian; Wu, Yi-Chen; Yen, Wen-Yen

2014-08-01

DNA damage has been shown to induce autophagy, but the role of autophagy in the DNA damage response and cell fate is not fully understood. BO-1012, a bifunctional alkylating derivative of 3a-aza-cyclopenta[a]indene, is a potent DNA interstrand cross-linking agent with anticancer activity. In this study, BO-1012 was found to reduce DNA synthesis, inhibit S phase progression, and induce phosphorylation of histone H2AX on serine 139 (γH2AX) exclusively in S phase cells. Both CHK1 and CHK2 were phosphorylated in response to BO-1012 treatment, but only depletion of CHK1, but not CHK2, impaired BO-1012-induced S phase arrest and facilitated the entry ofmore » γH2AX-positive cells into G2 phase. CHK1 depletion also significantly enhanced BO-1012-induced cell death and apoptosis. These results indicate that BO-1012-induced S phase arrest is a CHK1-dependent pro-survival response. BO-1012 also resulted in marked induction of acidic vesicular organelle (AVO) formation and microtubule-associated protein 1 light chain 3 (LC3) processing and redistribution, features characteristic of autophagy. Depletion of ATG7 or co-treatment of cells with BO-1012 and either 3-methyladenine or bafilomycin A1, two inhibitors of autophagy, not only reduced CHK1 phosphorylation and disrupted S phase arrest, but also increased cleavage of caspase-9 and PARP, and cell death. These results suggest that cells initiate S phase arrest and autophagy as pro-survival responses to BO-1012-induced DNA damage, and that suppression of autophagy enhances BO-1012-induced apoptosis via disruption of CHK1-dependent S phase arrest. - Highlights: • Autophagy inhibitors enhanced the cytotoxicity of a DNA alkylating agent, BO-1012. • BO-1012-induced S phase arrest was a CHK1-dependent pro-survival response. • Autophagy inhibition enhanced BO-1012 cytotoxicity via disrupting the S phase arrest.« less

Oleiferoside W from the roots of Camellia oleifera C. Abel, inducing cell cycle arrest and apoptosis in A549 cells.

PubMed

Wu, Jiang-Ping; Kang, Nai-Xin; Zhang, Mi-Ya; Gao, Hong-Wei; Li, Xiao-Ran; Liu, Yan-Li; Xu, Qiong-Ming; Yang, Shi-Lin

2017-07-06

Camellia oleifera C. Abel has been widely cultivated in China, and a group of bioactive constituents such as triterpeniod saponin have been isolated from C. oleifera C. Abel. In the current study, a new triterpeniod saponin was isolated from the EtOH extract of the roots of C. oleifera C. Abel, named as oleiferoside W, and the cytotoxic properties of oleiferoside W were evaluated in non-small cell lung cancer A549 cells. At the same time the inducing apoptosis, the depolarization of mitochondrial membrane potential (Δψ), the up-regulation of related pro-apoptotic proteins, such as cleaved-PARP, cleaved-caspase-3, and the down-regulation of anti-apoptotic marker Bcl-2/Bax were measured on oleiferoside W. Furthermore, the function, inducing the generation of reactive oxygen species (ROS) and apoptosis, of oleiferoside W could be reversed by N-acetylcysteine (NAC). In conclusion, our findings showed that oleiferoside W induced apoptosis involving mitochondrial pathway and increasing intracellular ROS production in the A549 cells, suggesting that oleiferoside W may have the possibility to be a useful anticancer agent for therapy in lung cancer.

Anti-tumor activity and mechanism of apoptosis of A549 induced by ruthenium complex.

PubMed

Sun, Dongdong; Mou, Zhipeng; Li, Nuan; Zhang, Weiwei; Wang, Yazhe; Yang, Endong; Wang, Weiyun

2016-12-01

Two new ruthenium (II) polypyridyl complexes [Ru(MeIm) 4 (pip)] 2+ (1) and [Ru(MeIm) 4 (4-npip)] 2+ (2) were synthesized under the guidance of computational studies (DFT). Their binding property to human telomeric G-quadruplex studied by UV-Vis absorption spectroscopy, the fluorescent resonance energy transfer (FRET) melting assay and circular dichroism (CD) spectroscopy for validating the theoretical prediction. Both of them were evaluated for their potential anti-proliferative activity against four human tumor cell lines. Complex 2 shows growth inhibition against all the cell lines tested, especially the human lung tumor cell (A549). The RTCA analysis not only validated the inhibition activity but also showed the ability of reducing A549 cells' migration. DNA-flow cytometric analysis, mitochondrial membrane potential (ΔΨm) and the scavenger measurements of reactive oxygen species (ROS) analysis carried out to investigate the mechanism of cell growth inhibition and apoptosis-inducing effect of complex 2. The results demonstrated that complex 2 induces tumor cells apoptosis by acting on both mitochondrial homeostasis destruction and death receptor signaling pathways. And those suggested that complex 2 could be a candidate for further evaluation as a chemotherapeutic agent against human tumor.

Withaferin-A induces apoptosis in osteosarcoma U2OS cell line via generation of ROS and disruption of mitochondrial membrane potential.

PubMed

Li, A-X; Sun, M; Li, X

2017-03-01

Withaferin-A (WF-A) is a well-known dietary compound isolated from Withania somnifera. It has marked pharmacological potential and has been shown to exhibit antiproliferative activity against several types of cancerous cells. Currently, the main focus of anti-cancer therapeutic development is to identify apoptosis-inducing drug-like molecules. Osteosarcoma is a rare type of bone cancer affecting humans. The objective of the present study was therefore to evaluate the antitumor potential of WF-A against several osteosarcoma cell lines. MTT assay was used to evaluate WF-A against osteosarcoma cell lines and to calculate the IC50. DAPI staining was used to confirm the apoptosis-inducing potential of WF-A. Mitochondrial membrane potential, reactive oxygen species (ROS) assay, and Western blotting were used to confirm the basis of apoptosis. The results of the present study revealed that WF-A exhibited strong antiproliferative activity against all the cells lines, with IC50 ranging from 0.32 to 7.6 µM. The lowest IC50 (0.32 µM) was observed against U2OS cell line and, therefore, it was selected for further analysis. DAPI staining indicated that WF-A exhibited antiproliferative activity via induction of apoptosis. Moreover, WF-A induced a ROS-mediated reduction in mitochondrial membrane potential in a dose-dependent manner and activation of caspase-3 in osteosarcoma cells. We suggest that WF-A may prove a potent therapeutic agent for inducing apoptosis in osteosarcoma cell lines via generation of ROS and disruption of mitochondrial membrane potential.

A polysaccharide from Sanguisorbae radix induces caspase-dependent apoptosis in human leukemia HL-60 cells.

PubMed

Wu, Zhigang; Sun, Honghui; Li, Jingzhong; Ma, Chijiao; Zhao, Siqiao; Guo, Zheng; Lin, Yao; Lin, Yaping; Liu, Li

2014-09-01

One polysaccharide (SRP) was purified from Sanguisorbae radix by DEAE-cellulose-52 anion-exchange and Sephacryl S-400 gel filtration chromatography. The aim of this study was to evaluate the anticancer efficacy of SRP on human leukemia HL-60 cells in vitro and unveil the underlying mechanisms. Our results showed that SRP was able to suppress the proliferation of HL-60 cells in a dose-dependent manner by the mechanism involved in the induction of apoptosis. The increase in SRP-induced apoptosis was correlated with a rapid and sustained loss of mitochondrial transmembrane potential (ΔΨm) and a release of cytochrome c from the mitochondria into the cytosol. Furthermore, Western blot and RT-PCR analysis revealed that the protein and mRNA levels of antiapoptotic Bcl-2 were downregulated, whereas those of pro-apoptotic Bax were upregulated. Besides, caspase-9 and caspase-3 were activated, while caspase-8 was intact. Additionally, the apoptotic cells by SRP were significantly inhibited by a caspase-3 inhibitor (z-DEVD-fmk) or a caspase-9 inhibitor (Z-LETD-FMK), demonstrating the important role of caspase-9 and -3 in the process. Taken together, these findings provided evidence that SRP induced the apoptosis of HL-60 cells through an intrinsic mitochondria-mediated signaling pathway and SRP may be a promising chemotherapeutic agent for treatment of leukemia. Copyright © 2014 Elsevier B.V. All rights reserved.

Phosphorylation status modulates Bcl-2 function during glucocorticoid-induced apoptosis in T lymphocytes.

PubMed

Huang, Se-Te J; Cidlowski, John A

2002-06-01

Glucocorticoids are known to induce apoptosis in lymphoid cells, and Bcl-2 overexpression can block the apoptosis-inducing action of glucocorticoids. Since phosphorylation of Bcl-2 is implicated in regulating Bcl-2 function, we considered the role of Bcl-2 phosphorylation in protecting lymphoid cells from glucocorticoid-induced cell death. Five stably transfected cell lines of WEHI 7.1 cells expressing either wild-type Bcl-2 or alanine mutants of Bcl-2 at amino acids threonine 56, serine 70, threonine 74, or serine 87 were created. Expression of the mutant Bcl-2 proteins was documented by flow cytometry and Western blot analysis. Mutation of Bcl-2 on T56 and S87 eliminated the ability of Bcl-2 to inhibit glucocorticoid-induced cell shrinkage, mitochondrial depolarization, DNA fragmentation, and cell death. Mutation of T74 only partially impaired the ability of Bcl-2 to block glucocorticoid-induced apoptosis whereas mutation of S70 in Bcl-2 did not alter its ability to block glucocorticoid-induced apoptosis.

Human Embryonic and Induced Pluripotent Stem Cells Express TRAIL Receptors and Can Be Sensitized to TRAIL-Induced Apoptosis

PubMed Central

Vinarsky, Vladimir; Krivanek, Jan; Rankel, Liina; Nahacka, Zuzana; Barta, Tomas; Jaros, Josef; Andera, Ladislav

2013-01-01

Death ligands and their tumor necrosis factor receptor (TNFR) family receptors are the best-characterized and most efficient inducers of apoptotic signaling in somatic cells. In this study, we analyzed whether these prototypic activators of apoptosis are also expressed and able to be activated in human pluripotent stem cells. We examined human embryonic stem cells (hESC) and human-induced pluripotent stem cells (hiPSC) and found that both cell types express primarily TNF-related apoptosis-inducing ligand (TRAIL) receptors and TNFR1, but very low levels of Fas/CD95. We also found that although hESC and hiPSC contain all the proteins required for efficient induction and progression of extrinsic apoptotic signaling, they are resistant to TRAIL-induced apoptosis. However, both hESC and hiPSC can be sensitized to TRAIL-induced apoptosis by co-treatment with protein synthesis inhibitors such as the anti-leukemia drug homoharringtonine (HHT). HHT treatment led to suppression of cellular FLICE inhibitory protein (cFLIP) and Mcl-1 expression and, in combination with TRAIL, enhanced processing of caspase-8 and full activation of caspase-3. cFLIP likely represents an important regulatory node, as its shRNA-mediated down-regulation significantly sensitized hESC to TRAIL-induced apoptosis. Thus, we provide the first evidence that, irrespective of their origin, human pluripotent stem cells express canonical components of the extrinsic apoptotic system and on stress can activate death receptor-mediated apoptosis. PMID:23806100

Feruloylserotonin inhibits hydrogen peroxide-induced melanogenesis and apoptosis in B16F10 and SK-Mel-2 melanoma cells.

PubMed

Cho, Hyejoung; Kim, Okjoon; Lee, Younghee; Kang, Li-Jung; Nguyen, Cam Ngoc; Ishihara, Atsushi; Kim, Hye-Eun

2017-09-30

Feruloylserotonin (FS) is a major bioactive component of safflower seeds, with documented strong antibacterial, anti-inflammatory, and free radical scavenging activities. Reactive oxygen species (ROS) can strongly induce melanogenesis and cell apoptosis. The present study aimed to investigate the ability of FS in preventing hydrogen peroxide (H 2 O 2 )-induced melanogenesis and cell apoptosis. Melanogenesis and apoptotic cell death were induced by transient exposure to H 2 O 2 in B16F10 and SK-Mel-2 melanoma cells. FS significantly inhibited melanogenesis and cell death in both cell lines. FS inhibited H 2 O 2 -induced melanin production by down-regulating CREB/MITF/TYR signaling via inhibited intracellular cAMP accumulation. Additionally, FS induced extracellular regulated kinase activation, which led to the degradation of MITF and consequently decreased TYR expression and melanin production in H 2 O 2 -stimulated cells. Furthermore, FS inhibited H 2 O 2 -induced apoptotic cell death by maintaining mitochondrial membrane potential. Therefore, FS might have potential use for cosmetic whitening and as a therapeutic agent for hyperpigmentation disorder. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Synthesis of sphingosine is essential for oxidative stress-induced apoptosis of photoreceptors.

PubMed

Abrahan, Carolina E; Miranda, Gisela E; Agnolazza, Daniela L; Politi, Luis E; Rotstein, Nora P

2010-02-01

Oxidative stress is involved in inducing apoptosis of photoreceptors in many retinal neurodegenerative diseases. It has been shown that oxidative stress increases in photoreceptors the synthesis of ceramide, a sphingolipid precursor that then activates apoptosis. In several cell types, ceramide is converted by ceramidases to sphingosine (Sph), another apoptosis mediator; hence, this study was undertaken to determine whether Sph participates in triggering photoreceptor apoptosis. Rat retina neurons were incubated with [(3)H]palmitic acid and treated with the oxidant paraquat (PQ) to evaluate Sph synthesis. Sph was added to cultures with or without docosahexaenoic acid (DHA), the major retina polyunsaturated fatty acid and a photoreceptor survival factor, to evaluate apoptosis. Synthesis of Sph and sphingosine-1-phosphate (S1P), a prosurvival signal, were inhibited with alkaline ceramidase or sphingosine kinase inhibitors, respectively, before adding PQ, C(2)-ceramide, or Sph. Apoptosis, mitochondrial membrane polarization, cytochrome c localization, and reactive oxygen species (ROS) production were determined. PQ increased [(3)H]Sph synthesis in photoreceptors and blocking this synthesis by inhibiting alkaline ceramidase decreased PQ-induced apoptosis. Addition of Sph induced photoreceptor apoptosis, increased ROS production, and promoted cytochrome c release from mitochondria. Although DHA prevented this apoptosis, inhibiting Sph conversion to S1P blocked DHA protection. These results suggest that oxidative stress enhances formation of ceramide and its subsequent breakdown to Sph; ceramide and/or Sph would then trigger photoreceptor apoptosis. Preventing Sph synthesis or promoting its phosphorylation to S1P rescued photoreceptors, suggesting that Sph is a mediator of their apoptosis and modulation of Sph metabolism may be crucial for promoting photoreceptor survival.

Plasmodium falciparum, but not P. vivax, can induce erythrocytic apoptosis.

PubMed

Totino, Paulo Renato Rivas; Magalhães, Aline das Dores; Alves, Eliana Brasil; Costa, Monica Regina Farias; de Lacerda, Marcus Vinícius Guimarães; Daniel-Ribeiro, Cláudio Tadeu; Ferreira-da-Cruz, Maria de Fátima

2014-10-18

Apoptosis can occur in red blood cells (RBC) and seems to be involved in hematologic disorders related to many diseases. In malaria it is known that parasitized RBC (pRBC) is involved in the development of anemia and thrombosis; however, non-parasitized RBC (nRBC) apoptosis could amplify these malaria-associated hematologic events. In fact, in experimental malaria, increased levels of apoptosis were observed in nRBC during lethal Plasmodium yoelii 17XL infection, but in human malaria erythrocytic apoptosis has never been studied. The present study was performed to investigate if nRBC apoptosis also occurs in P. vivax and P. falciparum infections. Apoptosis of nRBC was evaluated in blood samples of P. vivax malaria patients and clinically healthly individuals living in Manaus, Brazil, both ex vivo and after incubation of RBC for 24 h. Additionally, the capacity of plasma from P. vivax or P. falciparum patients was tested for induction of in vitro apoptosis of normal RBC from a clinically healthy individual living in a non-endemic malaria region. Apoptosis was detected by flow cytometry using annexin V staining. In contrast to experimental malaria that significantly increased the levels of apoptotic nRBC both ex-vivo and after 24 h of incubation, no significant alteration on apoptotic nRBC rates was detected in P. vivax infected patients when compared with non-infected control individuals. Similar results were observed when plasma of these P. vivax patients was incubated with normal RBC. Conversely, plasma from P. falciparum-infected subjects induced significant apoptosis of these cells. Apoptosis of normal RBC can be induced by plasma from individuals with P. falciparum (but not with P. vivax) malaria. This finding could reflect the existence of erythrocytic apoptosis during infection that could contribute to the pathogenesis of hematological and vascular complications associated with falciparum malaria.

Edaravone is a candidate agent for spinal muscular atrophy: In vitro analysis using a human induced pluripotent stem cells-derived disease model.

PubMed

Ando, Shiori; Funato, Michinori; Ohuchi, Kazuki; Kameyama, Tsubasa; Inagaki, Satoshi; Seki, Junko; Kawase, Chizuru; Tsuruma, Kazuhiro; Shimazawa, Masamitsu; Kaneko, Hideo; Hara, Hideaki

2017-11-05

Spinal muscular atrophy (SMA) is an intractable disease characterized by a progressive loss of spinal motor neurons, which leads to skeletal muscle weakness and atrophy. Currently, there are no curative agents for SMA, although it is understood to be caused by reduced levels of survival motor neuron (SMN) protein. Additionally, why reduced SMN protein level results in selective apoptosis in spinal motor neurons is still not understood. Our purpose in this study was to evaluate the therapeutic potential of edaravone, a free radical scavenger, by using induced pluripotent stem cells from an SMA patient (SMA-iPSCs) and to address oxidative stress-induced apoptosis in spinal motor neurons. We first found that edaravone could improve impaired neural development of SMA-iPSCs-derived spinal motor neurons with limited effect on nuclear SMN protein expression. Furthermore, edaravone inhibited the generation of reactive oxygen species and mitochondrial reactive oxygen species upregulated in SMA-iPSCs-derived spinal motor neurons, and reversed oxidative-stress induced apoptosis. In this study, we suggest that oxidative stress might be partly the reason for selective apoptosis in spinal motor neurons in SMA pathology, and that oxidative stress-induced apoptosis might be the therapeutic target of SMA. Copyright © 2017 Elsevier B.V. All rights reserved.

Mycobacterium avium MAV2052 protein induces apoptosis in murine macrophage cells through Toll-like receptor 4.

PubMed

Lee, Kang-In; Choi, Han-Gyu; Son, Yeo-Jin; Whang, Jake; Kim, Kwangwook; Jeon, Heat Sal; Park, Hye-Soo; Back, Yong Woo; Choi, Seunga; Kim, Seong-Woo; Choi, Chul Hee; Kim, Hwa-Jung

2016-04-01

Mycobacterium avium and its sonic extracts induce apoptosis in macrophages. However, little is known about the M. avium components regulating macrophage apoptosis. In this study, using multidimensional fractionation, we identified MAV2052 protein, which induced macrophage apoptosis in M. avium culture filtrates. The recombinant MAV2052 induced macrophage apoptosis in a caspase-dependent manner. The loss of mitochondrial transmembrane potential (ΔΨm), mitochondrial translocation of Bax, and release of cytochrome c from mitochondria were observed in macrophages treated with MAV2052. Further, reactive oxygen species (ROS) production was required for the apoptosis induced by MAV2052. In addition, ROS and mitogen-activated protein kinases were involved in MAV2052-mediated TNF-α and IL-6 production. ROS-mediated activation of apoptosis signal-regulating kinase 1 (ASK1)-JNK pathway was a major signaling pathway for MAV2052-induced apoptosis. Moreover, MAV2052 bound to Toll-like receptor (TLR) 4 molecule and MAV2052-induced ROS production, ΔΨm loss, and apoptosis were all significantly reduced in TLR4(-/-) macrophages. Altogether, our results suggest that MAV2052 induces apoptotic cell death through TLR4 dependent ROS production and JNK pathway in murine macrophages.

Lipocalin-2 Induces Cardiomyocyte Apoptosis by Increasing Intracellular Iron Accumulation*

PubMed Central

Xu, Guoxiong; Ahn, JinHee; Chang, SoYoung; Eguchi, Megumi; Ogier, Arnaud; Han, SungJun; Park, YoungSam; Shim, ChiYoung; Jang, YangSoo; Yang, Bo; Xu, Aimin; Wang, Yu; Sweeney, Gary

2012-01-01

Our objective was to determine whether lipocalin-2 (Lcn2) regulates cardiomyocyte apoptosis, the mechanisms involved, and the functional significance. Emerging evidence suggests that Lcn2 is a proinflammatory adipokine associated with insulin resistance and obesity-related complications, such as heart failure. Here, we used both primary neonatal rat cardiomyocytes and H9c2 cells and demonstrated for the first time that Lcn2 directly induced cardiomyocyte apoptosis, an important component of cardiac remodeling leading to heart failure. This was shown by detection of DNA fragmentation using TUNEL assay, phosphatidylserine exposure using flow cytometry to detect annexin V-positive cells, caspase-3 activity using enzymatic assay and immunofluorescence, and Western blotting for the detection of cleaved caspase-3. We also observed that Lcn2 caused translocation of the proapoptotic protein Bax to mitochondria and disruption of mitochondrial membrane potential. Using transient transfection of GFP-Bax, we confirmed that Lcn2 induced co-localization of Bax with MitoTracker® dye. Importantly, we used the fluorescent probe Phen Green SK to demonstrate an increase in intracellular iron in response to Lcn2, and depleting intracellular iron using an iron chelator prevented Lcn2-induced cardiomyocyte apoptosis. Administration of recombinant Lcn2 to mice for 14 days increased cardiomyocyte apoptosis as well as an acute inflammatory response with compensatory changes in cardiac functional parameters. In conclusion, Lcn2-induced cardiomyocyte apoptosis is of physiological significance and occurs via a mechanism involving elevated intracellular iron levels and Bax translocation. PMID:22117066

Amphotericin B induces apoptosis-like programmed cell death in Naegleria fowleri and Naegleria gruberi.

PubMed

Cárdenas-Zúñiga, Roberto; Silva-Olivares, Angélica; Villalba-Magdaleno, José D' Artagnan; Sánchez-Monroy, Virginia; Serrano-Luna, Jesús; Shibayama, Mineko

2017-07-01

Naegleria fowleri and Naegleria gruberi belong to the free-living amoebae group. It is widely known that the non-pathogenic species N. gruberi is usually employed as a model to describe molecular pathways in this genus, mainly because its genome has been recently described. However, N. fowleri is an aetiological agent of primary amoebic meningoencephalitis, an acute and fatal disease. Currently, the most widely used drug for its treatment is amphotericin B (AmB). It was previously reported that AmB has an amoebicidal effect in both N. fowleri and N. gruberi trophozoites by inducing morphological changes that resemble programmed cell death (PCD). PCD is a mechanism that activates morphological, biochemical and genetic changes. However, PCD has not yet been characterized in the genus Naegleria. The aim of the present work was to evaluate the typical markers to describe PCD in both amoebae. These results showed that treated trophozoites displayed several parameters of apoptosis-like PCD in both species. We observed ultrastructural changes, an increase in reactive oxygen species, phosphatidylserine externalization and a decrease in intracellular potassium, while DNA degradation was evaluated using the TUNEL assay and agarose gels, and all of these parameters are related to PCD. Finally, we analysed the expression of apoptosis-related genes, such as sir2 and atg8, in N. gruberi. Taken together, our results showed that AmB induces the morphological, biochemical and genetic changes of apoptosis-like PCD in the genus Naegleria.

Endogenous c-Myc is essential for p53-induced apoptosis in response to DNA damage in vivo.

PubMed

Phesse, T J; Myant, K B; Cole, A M; Ridgway, R A; Pearson, H; Muncan, V; van den Brink, G R; Vousden, K H; Sears, R; Vassilev, L T; Clarke, A R; Sansom, O J

2014-06-01

Recent studies have suggested that C-MYC may be an excellent therapeutic cancer target and a number of new agents targeting C-MYC are in preclinical development. Given most therapeutic regimes would combine C-MYC inhibition with genotoxic damage, it is important to assess the importance of C-MYC function for DNA damage signalling in vivo. In this study, we have conditionally deleted the c-Myc gene in the adult murine intestine and investigated the apoptotic response of intestinal enterocytes to DNA damage. Remarkably, c-Myc deletion completely abrogated the immediate wave of apoptosis following both ionizing irradiation and cisplatin treatment, recapitulating the phenotype of p53 deficiency in the intestine. Consistent with this, c-Myc-deficient intestinal enterocytes did not upregulate p53. Mechanistically, this was linked to an upregulation of the E3 Ubiquitin ligase Mdm2, which targets p53 for degradation in c-Myc-deficient intestinal enterocytes. Further, low level overexpression of c-Myc, which does not impact on basal levels of apoptosis, elicited sustained apoptosis in response to DNA damage, suggesting c-Myc activity acts as a crucial cell survival rheostat following DNA damage. We also identify the importance of MYC during DNA damage-induced apoptosis in several other tissues, including the thymus and spleen, using systemic deletion of c-Myc throughout the adult mouse. Together, we have elucidated for the first time in vivo an essential role for endogenous c-Myc in signalling DNA damage-induced apoptosis through the control of the p53 tumour suppressor protein.

Osthole induces human nasopharyngeal cancer cells apoptosis through Fas-Fas ligand and mitochondrial pathway.

PubMed

Liu, Pei-Ying; Chang, Dun-Cheng; Lo, Yu-Sheng; Hsi, Yi-Ting; Lin, Chia-Chieh; Chuang, Yi-Ching; Lin, Shu-Hui; Hsieh, Ming-Ju; Chen, Mu-Kuan

2018-04-01

Nasopharyngeal carcinoma (NPC) is endemic in Southern China and Southeast Asia. The present study investigated the activity of osthole in suppressing NPC along with the underlying mechanism. Cell growth inhibition was measured using the MTT assay. Apoptosis was detected through 4',6-diamidino-2-phenylindole staining and flow cytometry. Western blotting was used to identify the signaling pathway. Osthole markedly inhibited cell proliferation and induced apoptosis in the NPC cell line. Western blotting results revealed the increased activation of caspases 3, 8, and 9 and poly (ADP-ribose) polymerase. Osthole treatment significantly reduced the expression of the antiapoptotic protein Bcl-2 and increased the expression of the proapoptotic proteins Bax, Bak, BimL, BimS, and t-Bid. Osthole treatment also increased the expression of Fas, FADD, TNF-R1, TNF-R2, DcR2, RIP, and DR5. In addition, osthole treatment significantly increased the expression levels of phosphorylated ERK1/2 and JNK1/2. These results suggested that osthole exerts cytotoxic effects on NPC cell lines mainly through apoptosis mediated by the Fas-Fas ligand and mitochondrial pathway. Osthole could be a potential anticancer agent for NPC. © 2018 Wiley Periodicals, Inc.

All-Trans Retinoic Acid Ameliorates Arsenic-Induced Oxidative Stress and Apoptosis in the Rat Uterus by Modulating MAPK Signaling Proteins.

PubMed

Chatterjee, Aniruddha; Chatterji, Urmi

2017-11-01

Exposure to arsenic leads to inhibition of the anti-oxidant defense mechanism of the body. Reactive oxygen species generated in response to arsenic causes reproductive failures in exposed females and also acts as an inducer of apoptosis. As a prospective remedial agent, all-trans retinoic acid (ATRA) was assessed for reversing arsenic-induced oxidative stress and apoptosis. Rats exposed to arsenic for 28 days were allowed to recover naturally or were treated simultaneously with ATRA for 28 days or up to 56 days. Production of H 2 O 2 was detected using 2',7'-dichlorfluorescein diacetate (DCFCA) by flow cytometry. Catalase, superoxide dismutase, glutathione, ALT, and AST were estimated by biochemical assays and Western blot analyses. Detection of apoptosis was performed using annexin V-FITC/propidium iodide. Expressions of p53, p21, cleaved caspase 3, JNK/pJNK, and ERK/pERK levels were estimated using Western blot analysis. Elemental arsenic deposition in the rat uterus and liver was estimated by atomic absorption spectrophotometry. Our results confirmed that ATRA ameliorated sodium arsenite-induced ROS generation, restored redox balance, and prevented apoptosis. Concomitant recovery was observed to be more prominent for ATRA-treated rats as compared to the rats that were allowed to recover naturally for 56 days. Tissue arsenic deposition was significantly reduced in the uterus upon continuous ATRA treatment. The results revealed that ATRA reversed arsenic-induced free radical generation, activated the anti-oxidant defence system, and subsequently repressed p53-dependent apoptosis through inhibition of the MAPK signaling components. J. Cell. Biochem. 118: 3796-3809, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Gonadal steroids modulate Fas-induced apoptosis of lactotropes and somatotropes.

PubMed

Jaita, Gabriela; Zárate, Sandra; Ferrari, Luciana; Radl, Daniela; Ferraris, Jimena; Eijo, Guadalupe; Zaldivar, Verónica; Pisera, Daniel; Seilicovich, Adriana

2011-02-01

We have previously reported that Fas activation induces apoptosis of anterior pituitary cells from rats at proestrus but not at diestrus and in an estrogen-dependent manner. In this study, we evaluated the effect of Fas activation on apoptosis of lactotropes and somatotropes during the estrous cycle and explored the action of gonadal steroids on Fas-induced apoptosis. Also, we studied whether changes in Fas expression are involved in the apoptotic response of anterior pituitary cells. Fas activation increased the percentage of TUNEL-positive lactotropes and somatotropes at proestrus but not at diestrus. FasL triggered apoptosis of somatotropes only when cells from ovariectomized rats were cultured in the presence of 17 β-estradiol (E2). Progesterone (P4) blocked the apoptotic action of the Fas/FasL system in lactotropes and somatotropes incubated with E2. Both E2 and P4 increased the percentage of cells expressing Fas at the cell membrane. Our results show that Fas activation induces apoptosis of lactotropes and somatotropes at proestrus but not at diestrus. Gonadal steroids may be involved in the apoptotic response of lactotropes and somatotropes, suggesting that Fas activation is implicated in the renewal of these pituitary subpopulations during the estrous cycle. The effect of gonadal steroids on Fas expression may be only partially involved in regulation of the Fas/FasL apoptotic pathway in the anterior pituitary gland.

Clinostat rotation induces apoptosis in luteal cells of the pregnant rat

NASA Technical Reports Server (NTRS)

Yang, Hyunwon; Bhat, Ganapathy K.; Sridaran, Rajagopala

2002-01-01

Recent studies have shown that microgravity induces changes at the cellular level, including apoptosis. However, it is unknown whether microgravity affects luteal cell function. This study was performed to assess whether microgravity conditions generated by clinostat rotation induce apoptosis and affect steroidogenesis by luteal cells. Luteal cells isolated from the corpora lutea of Day 8 pregnant rats were placed in equal numbers in slide flasks (chamber slides). One slide flask was placed in the clinostat and the other served as a stationary control. At 48 h in the clinostat, whereas the levels of progesterone and total cellular protein decreased, the number of shrunken cells increased. To determine whether apoptosis occurred in shrunken cells, Comet and TUNEL assays were performed. At 48 h, the percentage of apoptotic cells in the clinostat increased compared with that in the control. To investigate how the microgravity conditions induce apoptosis, the active mitochondria in luteal cells were detected with JC-1 dye. Cells in the control consisted of many active mitochondria, which were evenly distributed throughout the cell. In contrast, cells in the clinostat displayed fewer active mitochondria, which were distributed either to the outer edge of the cell or around the nucleus. These results suggest that mitochondrial dysfunction induced by clinostat rotation could lead to apoptosis in luteal cells and suppression of progesterone production.

Radiation-Induced Salivary Gland Dysfunction Results From p53-Dependent Apoptosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Avila, Jennifer L.; Grundmann, Oliver; Burd, Randy

2009-02-01

Purpose: Radiotherapy for head-and-neck cancer causes adverse secondary side effects in the salivary glands and results in diminished quality of life for the patient. A previous in vivo study in parotid salivary glands demonstrated that targeted head-and-neck irradiation resulted in marked increases in phosphorylated p53 (serine{sup 18}) and apoptosis, which was suppressed in transgenic mice expressing a constitutively active mutant of Akt1 (myr-Akt1). Methods and Materials: Transgenic and knockout mouse models were exposed to irradiation, and p53-mediated transcription, apoptosis, and salivary gland dysfunction were analyzed. Results: The proapoptotic p53 target genes PUMA and Bax were induced in parotid salivary glandsmore » of mice at early time points after therapeutic radiation. This dose-dependent induction requires expression of p53 because no radiation-induced expression of PUMA and Bax was observed in p53-/- mice. Radiation also induced apoptosis in the parotid gland in a dose-dependent manner, which was p53 dependent. Furthermore, expression of p53 was required for the acute and chronic loss of salivary function after irradiation. In contrast, apoptosis was not induced in p53-/- mice, and their salivary function was preserved after radiation exposure. Conclusions: Apoptosis in the salivary glands after therapeutic head-and-neck irradiation is mediated by p53 and corresponds to salivary gland dysfunction in vivo.« less

Anethole prevents hydrogen peroxide-induced apoptosis and collagen metabolism alterations in human skin fibroblasts.

PubMed

Galicka, Anna; Krętowski, Rafał; Nazaruk, Jolanta; Cechowska-Pasko, Marzanna

2014-09-01

The collagen metabolism alterations triggered by reactive oxygen species are involved in the development of various connective tissue diseases and skin aging. This study was designed to examine whether (E)-anethole possesses a protective effect on H2O2-induced alterations in collagen metabolism as well as whether it can prevent apoptosis in human skin fibroblasts. In cells treated with 300 µM H₂O₂, a decrease in collagen biosynthesis of 54% was observed. Pretreatment of cells with 0.5 µM anethole for 1 h completely prevented this alteration. Changes at the protein level positively correlated with alterations of type I collagen mRNA expression. We have shown that H2O2 caused increase in the activity of MMP-2 and MMP-9 as well as that an increase in MMP-2 activity can contribute to the 8% decrease in the amount of collagen secreted into the medium. The most efficient suppression of these changes was observed in the presence of 0.5 µM of anethole. At 10 µM, in addition to suppression, an inhibitory effect of anethole on MMP-9 activity was documented. Additionally, the 60% H₂O₂-induced decrease in cell viability was suppressed by 1 µM of anethole and a 4-fold increase in cell apoptosis was suppressed by 0.5 µM of anethole. Our results suggest that anethole, which is a small lipophilic and non-toxic molecule with the ability to prevent H₂O₂-induced collagen metabolism alterations and apoptosis in human skin fibroblasts, would prove useful in the development of effective agents in pharmacotherapy of oxidative stress-related skin diseases.

In vitro and in vivo sensitization of SW620 metastatic colon cancer cells to CDDP-induced apoptosis by the nitric oxide donor DETANONOate: Involvement of AIF.

PubMed

Huerta, Sergio; Baay-Guzman, Guillermina; Gonzalez-Bonilla, Cesar R; Livingston, Edward H; Huerta-Yepez, Sara; Bonavida, Benjamin

2009-05-01

Tumor cells develop mechanisms that dysregulate apoptotic pathways resulting in resistance to cytotoxic stimuli. Primary SW480 and metastatic SW620 colon cancer cells are resistant to CDDP-induced apoptosis. Apoptosis-inducing factor (AIF) was significantly downregulated in SW620 compared to SW480 cells; while apoptotic mediators such as Bax, Bcl-2, and Bcl(XL) were not altered in these cell lines. Examination of tumor tissues from patients with colon cancer demonstrated a significant downregulation of AIF in patients with advanced disease. The role of AIF expression in resistance was examined. Several lines of evidence suggest the involvement of AIF expression level in the sensitivity of SW620 to CDDP-induced apoptosis: (1) sensitization of SW620 by the NO donor DETANONOate to CDDP-induced apoptosis correlated with the induction of AIF as assessed by RT-PCR and Western blot analysis, (2) treatment of SW620 cells with siRNA AIF, but not with control siRNAs, inhibited DETANONOate-induced sensitization to CDDP apoptosis, (3) sensitization by DETANONOate observed in vitro was corroborated in vivo in nude mice bearing SW620 tumor xenografts and treated with the combination of DETANONOate and CDDP, and (4) tumor tissues derived from the SW620 xenografts revealed significant upregulation of AIF and increased apoptosis by DETANONOate and CDDP combination treatment. Altogether, these findings underscore the potential therapeutic application of NO donors and subtoxic chemotherapeutic drugs in the treatment of advanced colon cancer resistant to conventional chemotherapeutic agents.

Resistance to etoposide-induced apoptosis in a Burkitt's lymphoma cell line.

PubMed

Zhao, E G; Song, Q; Cross, S; Misko, I; Lees-Miller, S P; Lavin, M F

1998-08-31

Burkitt's lymphoma cells that vary in their phenotypic characteristics show significantly different degrees of susceptibility to radiation-induced apoptosis. Propensity to undergo apoptosis is reflected in the degradation of substrates such as DNA-dependent protein kinase but the status of bcl-2, c-myc and p53 has been uninformative. In this study, we have focused on 2 Epstein-Barr virus (EBV)-associated Burkitt's cell lines, one (WW2) susceptible and the other (BL29) resistant to etoposide-induced apoptosis. Differences in expression of BHRF1, an EBV gene that is homologous to the Bcl-2 proto-oncogene and known to inhibit apoptosis, or changes in apoptosis inhibitory proteins (IAPs), did not appear to account for the difference in susceptibility in the 2 cell lines. Cytoplasmic extracts from etoposide-treated WW2 cells caused apoptotic changes in nuclei isolated from either BL29 or WW2 cells, whereas extracts from BL29 cells failed to do so. In addition, extracts from etoposide-treated WW2 cells degraded the catalytic subunit of DNA-dependent protein kinase (DNA-PKcs), an important indicator of apoptosis, but this protein was resistant to degradation by BL29 extracts. It appears likely that caspase 3 (CPP32) is involved in this degradation since it was activated only in the apoptosis susceptible cells and the pattern of cleavage of DNA-PKcs was similar to that reported previously with recombinant caspase 3. As observed previously, addition of caspase 3 to nuclei failed to induce morphological changes indicative of apoptosis, but addition of caspase 3 to nuclei in the presence of extract from the resistant cells led to apoptotic changes. We conclude that resistance to apoptosis in BL29 cells is due to a failure of etoposide to activate upstream effectors of caspase activity.

Role of β-Interferon Inducer (DEAE-Dextran) in Tumorigenesis by VEGF and NOTCH1 Inhibition along with Apoptosis Induction.

PubMed

Bakrania, Anita K; Variya, Bhavesh C; Patel, Snehal S

2017-01-01

As a novel target for breast cancer, interferon inducers have found its role as anti-angiogenic agents with diethylaminoethyl dextran (DEAE-Dextran) being a molecule used for centuries as a transfection agent. Our results herein offer an explanation for the emergence of DEAE-Dextran as an anti-tumor agent for TNBC with in-depth mechanistic approach as an anti-angiogenic molecule. DEAE-Dextran has found to possess cytotoxic activity demonstrated during the various in vitro cytotoxicity assays; moreover, as an anti-oxidant, DEAE-Dextran has shown to possess excellent reactive oxygen species scavenging activity. The interferon inducing capacity of DEAE-Dextran was determined qualitatively as well as quantitatively specifically demonstrating overexpression of β-interferon. As a measure of anti-proliferative activity, DEAE-Dextran exhibited reduced ki67, p53, and PCNA levels. Also, overexpression of CK5/6 and p63 in DEAE-Dextran treated animals indicated improvement in breast cell morphology along with an improvement in cell-cell adhesion by virtue of upregulation of β-catenin and E-cadherin. Anti-angiogenic property of DEAE-Dextran was concluded by the downregulation of CD31, VEGF, and NOTCH1 both in vivo and in vitro . Further, apoptosis due to DEAE-Dextran, initially determined by downregulation of Bcl2, was confirmed with flow cytometry. Overall, results are defensive of DEAE-Dextran as an emerging anti-tumor agent with mechanisms pertaining to β-interferon induction with probable VEGF and NOTCH1 inhibition as well as apoptosis which still needs to be studied in further depth.

Role of β-Interferon Inducer (DEAE-Dextran) in Tumorigenesis by VEGF and NOTCH1 Inhibition along with Apoptosis Induction

PubMed Central

Bakrania, Anita K.; Variya, Bhavesh C.; Patel, Snehal S.

2017-01-01

As a novel target for breast cancer, interferon inducers have found its role as anti-angiogenic agents with diethylaminoethyl dextran (DEAE-Dextran) being a molecule used for centuries as a transfection agent. Our results herein offer an explanation for the emergence of DEAE-Dextran as an anti-tumor agent for TNBC with in-depth mechanistic approach as an anti-angiogenic molecule. DEAE-Dextran has found to possess cytotoxic activity demonstrated during the various in vitro cytotoxicity assays; moreover, as an anti-oxidant, DEAE-Dextran has shown to possess excellent reactive oxygen species scavenging activity. The interferon inducing capacity of DEAE-Dextran was determined qualitatively as well as quantitatively specifically demonstrating overexpression of β-interferon. As a measure of anti-proliferative activity, DEAE-Dextran exhibited reduced ki67, p53, and PCNA levels. Also, overexpression of CK5/6 and p63 in DEAE-Dextran treated animals indicated improvement in breast cell morphology along with an improvement in cell–cell adhesion by virtue of upregulation of β-catenin and E-cadherin. Anti-angiogenic property of DEAE-Dextran was concluded by the downregulation of CD31, VEGF, and NOTCH1 both in vivo and in vitro. Further, apoptosis due to DEAE-Dextran, initially determined by downregulation of Bcl2, was confirmed with flow cytometry. Overall, results are defensive of DEAE-Dextran as an emerging anti-tumor agent with mechanisms pertaining to β-interferon induction with probable VEGF and NOTCH1 inhibition as well as apoptosis which still needs to be studied in further depth. PMID:29311933

Kinetics of apoptotic markers in exogeneously induced apoptosis of EL4 cells.

PubMed

Jessel, Robert; Haertel, Steffen; Socaciu, Carmen; Tykhonova, Svetlana; Diehl, Horst A

2002-01-01

We investigated the time-dependence of apoptotic events in EL4 cells by monitoring plasma membrane changes in correlation to DNA fragmentation and cell shrinkage. We applied three apoptosis inducers (staurosporine, tubericidine and X-rays) and we looked at various markers to follow the early-to-late apoptotic events: phospholipid translocation (identified through annexin V-fluorescein assay and propidium iodide), lipid package (via merocyanine assay), membrane fluidity and anisotropy (via fluorescent measurements), DNA fragmentation by the fluorescence-labeling test and cell size measurements. The different apoptotic inducers caused different reactions of the cells: staurosporine induced apoptosis most rapidly in a high number of cells, tubercidine triggered apoptosis only in the S phase cells, while X-rays caused a G2/M arrest and subsequently apoptosis. Loss of lipid asymmetry is promptly detectable after one hour of incubation time. The phosphatidylserine translocation, decrease of lipid package and anisotropy, and the increase of membrane fluidity appeared to be based on the same process of lipid asymmetry loss. Therefore, the DNA fragmentation and the cell shrinkage appear to be parallel and independent processes running on different time scales but which are kinetically inter-related. The results indicate different signal steps to apoptosis dependent on inducer characteristics but the kinetics of "early-to-late" apoptosis appears to be a fixed program.

EF24 induces ROS-mediated apoptosis via targeting thioredoxin reductase 1 in gastric cancer cells

PubMed Central

Chen, Weiqian; Chen, Xi; Ying, Shilong; Feng, Zhiguo; Chen, Tongke; Ye, Qingqing; Wang, Zhe; Qiu, Chenyu; Yang, Shulin; Liang, Guang

2016-01-01

Gastric cancer (GC) is one of the leading causes of cancer mortality in the world, and finding novel agents for the treatment of advanced gastric cancer is of urgent need. Diphenyl difluoroketone (EF24), a molecule having structural similarity to curcumin, exhibits potent anti-tumor activities by arresting cell cycle and inducing apoptosis. Although EF24 demonstrates potent anticancer efficacy in numerous types of human cancer cells, the cellular targets of EF24 have not been fully defined. We report here that EF24 may interact with the thioredoxin reductase 1 (TrxR1), an important selenocysteine (Sec)-containing antioxidant enzyme, to induce reactive oxygen species (ROS)-mediated apoptosis in human gastric cancer cells. By inhibiting TrxR1 activity and increasing intracellular ROS levels, EF24 induces a lethal endoplasmic reticulum stress in human gastric cancer cells. Importantly, knockdown of TrxR1 sensitizes cells to EF24 treatment. In vivo, EF24 treatment markedly reduces the TrxR1 activity and tumor cell burden, and displays synergistic lethality with 5-FU against gastric cancer cells. Targeting TrxR1 with EF24 thus discloses a previously unrecognized mechanism underlying the biological activity of EF24, and reveals that TrxR1 is a good target for gastric cancer therapy. PMID:26919110

Tea polyphenols induce S phase arrest and apoptosis in gallbladder cancer cells

PubMed Central

Wang, Jiaqi; Pan, Yixuan; Hu, Jiacheng; Ma, Qiang; Xu, Yi; Zhang, Yijian; Zhang, Fei; Liu, Yingbin

2018-01-01

Gallbladder cancer (GBC) is the most common malignancy in the biliary tract. Without effective treatment, its prognosis is notoriously poor. Tea polyphenols (TPs) have many pharmacological and health benefits, including antioxidant, anti-inflammatory, anti-tumor, anti-thrombotic, antibacterial, and vasodilatory properties. However, the anti-cancer effect of TPs in human gallbladder cancer has not yet been determined. Cell viability and colony formation assay were used to investigate the cell growth. Cell cycle and apoptosis were evaluated by flow cytometry analysis. Western blot assay was used to detect the expression of proteins related to cell cycle and apoptosis. Human tumor xenografts were used to examine the effect of TPs on gallbladder cancer cells in vivo. TPs significantly inhibited cell growth of gallbladder cancer cell lines in a dose- and time-dependent manner. Cell cycle progression in GBC cells was blocked at the S phase by TPs. TPs also induced mitochondrial-related apoptosis in GBC cells by upregulating Bax, cleaved caspase-3, and cleaved PARP expressions and downregulating Bcl-2, cyclin A, and Cdk2 expressions. The effects of TPs on GBC were further proven in vivo in a mouse xenograft model. Our study is the first to report that TPs inhibit GBC cell growth and these compounds may have potential as novel therapeutic agents for treating gallbladder cancer. PMID:29513793

DNA fragmentation and cell cycle arrest: a hallmark of apoptosis induced by crocin from kashmiri saffron in a human pancreatic cancer cell line.

PubMed

Bakshi, Hamid; Sam, Smitha; Rozati, Roya; Sultan, Phalisteen; Islam, Tajamul; Rathore, Babita; Lone, Zahoor; Sharma, Manik; Triphati, Jagrati; Saxena, Ramesh Chand

2010-01-01

Apoptosis, a widely important mechanism that contributes to cell growth reduction, is reported to be induced by Crocus sativus in different cancer types. The present study was designed to elucidate apoptosis induction by crocin, a main component of Crocus sativus in a human pancreatic cancer cell line (BxPC-3). Cell viability was measured by MTT assay, Hoechest33258 staining was used to detect the chromatin condensation characteristic of apoptosis, and DNA fragmentation was assessed by gel electrophoresis and cell cycle analysis by flow cytometry. Crocin induced apoptosis and G1-phase cell cycle arrest of BxPC-3 cells, while decreasing cell viability in a dose dependent and time dependent manner. Cells treated with 10μg/L crocin exhibited apoptotic morphology (brightly blue-fluorescent condensed nuclei on Hoechst 33258 staining) and reduction of volume. DNA analysis revealed typical ladders as early as 12 hours after treatment indicative of apoptosis. Our preclinical study demonstrated a pancreatic cancer cell line to be highly sensitive to crocin-mediated growth inhibition and apoptotic cell death. Although the molecular mechanisms of crocin action are not yet clearly understood, it appears to have potential as a therapeutic agent.

The pyrrolo-1,5-benzoxazepine, PBOX-15, enhances TRAIL-induced apoptosis by upregulation of DR5 and downregulation of core cell survival proteins in acute lymphoblastic leukaemia cells

PubMed Central

NATHWANI, SEEMA-MARIA; GREENE, LISA M.; BUTINI, STEFANIA; CAMPIANI, GIUSEPPE; WILLIAMS, D. CLIVE; SAMALI, AFSHIN; SZEGEZDI, EVA; ZISTERER, DANIELA M.

2016-01-01

Apoptotic defects are frequently associated with poor outcome in pediatric acute lymphoblastic leukaemia (ALL) hence there is an ongoing demand for novel strategies that counteract apoptotic resistance. The death ligand TRAIL (tumour necrosis factor-related apoptosis-inducing ligand) and its selective tumour receptor system has attracted exceptional clinical interest. However, many malignancies including ALL are resistant to TRAIL monotherapy. Tumour resistance can be overcome by drug combination therapy. TRAIL and its agonist antibodies are currently undergoing phase II clinical trials with established chemotherapeutics. Herein, we present promising therapeutic benefits in combining TRAIL with the selective anti-leukaemic agents, the pyrrolo-1,5-benzoxazepines (PBOXs) for the treatment of ALL. PBOX-15 synergistically enhanced apoptosis induced by TRAIL and a DR5-selective TRAIL variant in ALL-derived cells. PBOX-15 enhanced TRAIL-induced apoptosis by dual activation of extrinsic and intrinsic apoptotic pathways. The specific caspase-8 inhibitor, Z-IETD-FMK, identified the extrinsic pathway as the principal mode of apoptosis. We demonstrate that PBOX-15 can enhance TRAIL-induced apoptosis by upregulation of DR5, reduction of cellular mitochondrial potential, activation of the caspase cascade and downregulation of PI3K/Akt, c-FLIP, Mcl-1 and IAP survival pathways. Of note, the PI3K pathway inhibitor LY-294002 significantly enhanced the apoptotic potential of TRAIL and PBOX-15 validating the importance of Akt downregulation in the TRAIL/PBOX-15 synergistic combination. Considering the lack of cytotoxicity to normal cells and ability to downregulate several survival pathways, PBOX-15 may represent an effective agent for use in combination with TRAIL for the treatment of ALL. PMID:27176505

Caspase-1 Inflammasome Activation Mediates Homocysteine-Induced Pyrop-Apoptosis in Endothelial Cells

PubMed Central

Xi, Hang; Zhang, Yuling; Xu, Yanjie; Yang, William Y; Jiang, Xiaohua; Sha, Xiaojin; Cheng, Xiaoshu; Wang, Jingfeng; Qin, Xuebin; Yu, Jun; Ji, Yong; Yang, Xiaofeng; Wang, Hong

2016-01-01

Rationale Endothelial injury is an initial mechanism mediating cardiovascular disease. Objective Here, we investigated the effect of hyperhomocysteinemia (HHcy) on programed cell death in endothelial cells (EC). Methods and Results We established a novel flow-cytometric gating method to define pyrotosis (Annexin V−/Propidium iodide+). In cultured human EC, we found that: 1). Hcy and Lipopolysaccharide (LPS) individually and synergistically induced inflammatory pyroptotic and non-inflammatory apoptotic cell death. 2). Hcy/LPS induced caspase-1 activation prior to caspase-8, -9, -3 activations. 3). Caspase-1/3 inhibitors rescued Hcy/LPS-induced pyroptosis/apoptosis, but caspase-8/9 inhibitors had differential rescue effect. 4). Hcy/LPS induced NLRP3 protein, caused NLRP3-containing inflammasome assembly, caspase-1 activation and IL-1β cleavage/activation. 5). Hcy/LPS elevated intracellular reactive oxidative species (ROS). 6). Intracellular oxidative gradient determined cell death destiny as intermediate intracellular ROS levels are associated with pyroptosis, whereas, high ROS corresponded to apoptosis. 7). Hcy/LPS induced mitochondrial membrane potential collapse and cytochrome-c release, and increased Bax/Bcl-2 ratio which were attenuated by antioxidants and caspase-1 inhibitor. 8). Antioxidants extracellular superoxide dismutase and catalase prevented Hcy/LPS-induced caspase-1 activation, mitochondrial dysfunction and pyroptosis/apoptosis. In cystathionine β-synthase deficient (Cbs−/−) mice, severe HHcy induced caspase-1 activation in isolated lung EC and caspase-1 expression in aortic endothelium, and elevated aortic caspase-1,9 protein/activity and Bax/Bcl-2 ratio in Cbs−/− aorta and HUVEC. Finally, Hcy-induced DNA fragmentation was reversed in caspase-1−/− EC. HHcy-induced aortic endothelial dysfunction was rescued in caspase-1−/− and NLRP3−/− mice. Conclusion HHcy preferentially induces EC pyroptosis via caspase-1-dependent

ERdj5 sensitizes neuroblastoma cells to endoplasmic reticulum stress-induced apoptosis.

PubMed

Thomas, Christophoros G; Spyrou, Giannis

2009-03-06

Down-regulation of the unfolded protein response (UPR) can be therapeutically valuable in cancer treatment, and endoplasmic reticulum (ER)-resident chaperone proteins may thus be targets for developing novel chemotherapeutic strategies. ERdj5 is a novel ER chaperone that regulates the ER-associated degradation of misfolded proteins through its associations with EDEM and the ER stress sensor BiP. To investigate whether ERdj5 can regulate ER stress signaling pathways, we exposed neuroblastoma cells overexpressing ERdj5 to ER stress inducers. ERdj5 promoted apoptosis in tunicamycin, thapsigargin, and bortezomib-treated cells. To provide further evidence that ERdj5 induces ER stress-regulated apoptosis, we targeted Bcl-2 to ER of ERdj5-overexpressing cells. Targeting the Bcl-2 to ER prevented the apoptosis induced by ER stress inducers but not by non-ER stress apoptotic stimuli, suggesting induction of ER stress-regulated apoptosis by ERdj5. ERdj5 enhanced apoptosis by abolishing the ER stress-induced phosphorylation of eukaryotic translation initiation factor 2alpha (eIF2alpha) and the subsequent translational repression. ERdj5 was found to inhibit the eIF2alpha phosphorylation under ER stress through inactivating the pancreatic endoplasmic reticulum kinase. The compromised integrated stress response observed in ERdj5-overexpressing ER-stressed cells due to repressed eIF2alpha phosphorylation correlated with impaired neuroblastoma cell resistance under ER stress. These results demonstrate that ERdj5 decreases neuroblastoma cell survival by down-regulating the UPR, raising the possibility that this protein could be a target for anti-tumor approaches.

Amphiregulin suppresses epithelial cell apoptosis in lipopolysaccharide-induced lung injury in mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ogata-Suetsugu, Saiko; Yanagihara, Toyoshi; Hamada, Naoki

Background and objective: As a member of the epidermal growth factor family, amphiregulin contributes to the regulation of cell proliferation. Amphiregulin was reported to be upregulated in damaged lung tissues in patients with chronic obstructive pulmonary disease and asthma and in lung epithelial cells in a ventilator-associated lung injury model. In this study, we investigated the effect of amphiregulin on lipopolysaccharide (LPS)-induced acute lung injury in mice. Methods: Acute lung injury was induced by intranasal instillation of LPS in female C57BL/6 mice, and the mice were given intraperitoneal injections of recombinant amphiregulin or phosphate-buffered saline 6 and 0.5 h before andmore » 3 h after LPS instillation. The effect of amphiregulin on apoptosis and apoptotic pathways in a murine lung alveolar type II epithelial cell line (LA-4 cells) were examined using flow cytometry and western blotting, respectively. Results: Recombinant amphiregulin suppressed epithelial cell apoptosis in LPS-induced lung injury in mice. Western blotting revealed that amphiregulin suppressed epithelial cell apoptosis by inhibiting caspase-8 activity. Conclusion: Amphiregulin signaling may be a therapeutic target for LPS-induced lung injury treatment through its prevention of epithelial cell apoptosis. - Highlights: • Amphiregulin suppresses epithelial cell apoptosis in LPS-induced lung injury in mice. • The mechanism relies on inhibiting caspase-8 activity. • Amphiregulin signaling may be a therapeutic target for LPS-induced lung injury.« less

Osthole induces apoptosis and suppresses proliferation via the PI3K/Akt pathway in intrahepatic cholangiocarcinoma.

PubMed

Zhu, Xingyang; Song, Xiaoling; Xie, Kun; Zhang, Xue; He, Wei; Liu, Fubao

2017-10-01

Osthole is a natural coumarin isolated from Umbelliferae plant monomers. Previous research has indicated that osthole exerts a wide variety of biological effects, acting as anti-seizure, anti-osteoporosis and anti-inflammation. However, the regulatory effect and related molecular mechanism of osthole in intrahepatic cholangiocarcinoma (ICC) remain unknown. In the present study, the authors found that osthole inhibited ICC cell lines in a dose- and time-dependent manner. Osthole also significantly induced mitochondrial-dependent apoptosis by upregulating Bax, cleaved caspase-3, cleaved caspase-9, and cleaved poly ADP-ribose polymerase expression, and by downregulating Bcl-2 expression. Moreover, the levels of p-Akt and PI3K were significantly decreased, while total Akt protein levels were unchanged. Following transfection with wild-type-Akt and constitutively active (CA)-Akt plasmids, the effects of osthole were decreased. Osthole was also able to suppress tumor growth in vivo. Together, these data demonstrated that osthole induces mitochondrial-dependent apoptosis via the PI3K/Akt pathway, suggesting that osthole may represent a novel and effective agent for the treatment of ICC.

TRAIL Enhances Shikonin Induced Apoptosis through ROS/JNK Signaling in Cholangiocarcinoma Cells.

PubMed

Zhou, Guangyao; Yang, Zuqin; Wang, Xiaodong; Tao, Ran; Zhou, Yuanping

2017-01-01

Cholangiocarcinoma (CCA), arising from varying locations within the biliary tree, is the second most common primary liver malignancy worldwide. Shikonin, an active compound extracted from the Chinese herb Zicao, holds anti-bacterial, anti-inflammatory, and anti-tumor activities. However, the effect of shikonin on human cholangiocarcinoma and detailed mechanisms of TRAIL enhancement remains to be elucidated. The purpose of the study was to investigate the protective functions of TRAIL enhancement for shikonin induced apoptosis in cholangiocarcinoma cells. We use MTT assay, apoptosis assay, caspase activity assay, flow cytometry assay, real time PCR and Western blot to observe the effects of TRAIL on shikonin induced cholangiocarcinoma cells apoptosis and its mechanism. Shikonin inhibited cell viability and induced apoptosis of CCA cells, effects enhanced by TRAIL treatment via activation of caspase-3, -8, -9. Furhermore, TRAIL enhanced anti-proliferation of shikonin and shikonin induced apoptosis through induction of ROS mediated JNK activation, while AKT activation had an effect on shikonin anti-proliferation activity, but not in the TRAIL enhanced counterparts. Finally, shikonin upregulated DR5 expression, an effect essential for TRAIL-enhanced activities of shikonin in RBE cells. Our results revealed that shikonin could inhibit cells viability and induce apoptosis of CCA cells, effects enhanced by TRAIL treatment via ROS mediated JNK signalling pathways, involving up-regulation of DR5 expression. Our results provide further insight into the mechanism underlying the anti-tumor effects of shikonin by TRAIL enhanced in CCA and a new therapeutic strategy to CCA treatment. © 2017 The Author(s). Published by S. Karger AG, Basel.

A novel role for the apoptosis inhibitor ARC in suppressing TNFα-induced regulated necrosis

PubMed Central

Kung, G; Dai, P; Deng, L; Kitsis, R N

2014-01-01

TNFα signaling can promote apoptosis or a regulated form of necrosis. ARC (apoptosis repressor with CARD (caspase recruitment domain)) is an endogenous inhibitor of apoptosis that antagonizes both the extrinsic (death receptor) and intrinsic (mitochondrial/ER) apoptosis pathways. We discovered that ARC blocks not only apoptosis but also necrosis. TNFα-induced necrosis was abrogated by overexpression of wild-type ARC but not by a CARD mutant that is also defective for inhibition of apoptosis. Conversely, knockdown of ARC exacerbated TNFα-induced necrosis, an effect that was rescued by reconstitution with wild-type, but not CARD-defective, ARC. Similarly, depletion of ARC in vivo exacerbated necrosis caused by infection with vaccinia virus, which elicits severe tissue damage through this pathway, and sensitized mice to TNFα-induced systemic inflammatory response syndrome. The mechanism underlying these effects is an interaction of ARC with TNF receptor 1 that interferes with recruitment of RIP1, a critical mediator of TNFα-induced regulated necrosis. These findings extend the role of ARC from an apoptosis inhibitor to a regulator of the TNFα pathway and an inhibitor of TNFα-mediated regulated necrosis. PMID:24440909

Bacopa monnieri-Induced Protective Autophagy Inhibits Benzo[a]pyrene-Mediated Apoptosis.

PubMed

Das, Durgesh Nandini; Naik, Prajna Paramita; Nayak, Aditi; Panda, Prashanta Kumar; Mukhopadhyay, Subhadip; Sinha, Niharika; Bhutia, Sujit K

2016-11-01

Benzo[a]pyrene (B[a]P) is capable of inducing oxidative stress and cellular injuries leading to cell death and associates with a significant risk of cancer development. Prevention of B[a]P-induced cellular toxicity with herbal compound through regulation of mitochondrial oxidative stress might protect cell death and have therapeutic benefit to human health. In this study, we demonstrated the cytoprotective role of Bacopa monnieri (BM) against B[a]P-induced apoptosis through autophagy induction. Pretreatment with BM rescued the reduction in cell viability in B[a]P-treated human keratinocytes (HaCaT) cells indicating the cytoprotective potential of BM against B[a]P. Moreover, BM was found to inhibit B[a]P-mediated reactive oxygen species (ROS)-induced apoptosis activation in HaCaT cells. Furthermore, BM was found to preserve mitochondrial membrane potential and inhibited release of cytochrome c in B[a]P-treated HaCaT cells. Bacopa monnieri induced protective autophagy; we knocked down Beclin-1, and data showed that BM was unable to protect from B[a]P-induced mitochondrial ROS-mediated apoptosis in Beclin-1-deficient HaCaT cells. Moreover, we established that B[a]P-induced damaged mitochondria were found to colocalize and degraded within autolysosomes in order to protect HaCaT cells from mitochondrial injury. In conclusion, B[a]P-induced apoptosis was rescued by BM treatment and provided cytoprotection through Beclin-1-dependent autophagy activation. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Autophagy mediated CoCrMo particle-induced peri-implant osteolysis by promoting osteoblast apoptosis

PubMed Central

Wang, Zhenheng; Liu, Naicheng; Liu, Kang; Zhou, Gang; Gan, Jingjing; Wang, Zhenzhen; Shi, Tongguo; He, Wei; Wang, Lintao; Guo, Ting; Bao, Nirong; Wang, Rui; Huang, Zhen; Chen, Jiangning; Dong, Lei; Zhao, Jianning; Zhang, Junfeng

2015-01-01

Wear particle-induced osteolysis is the leading cause of aseptic loosening, which is the most common reason for THA (total hip arthroplasty) failure and revision surgery. Although existing studies suggest that osteoblast apoptosis induced by wear debris is involved in aseptic loosening, the underlying mechanism linking wear particles to osteoblast apoptosis remains almost totally unknown. In the present study, we investigated the effect of autophagy on osteoblast apoptosis induced by CoCrMo metal particles (CoPs) in vitro and in a calvarial resorption animal model. Our study demonstrated that CoPs stimulated autophagy in osteoblasts and PIO (particle-induced osteolysis) animal models. Both autophagy inhibitor 3-MA (3-methyladenine) and siRNA of Atg5 could dramatically reduce CoPs-induced apoptosis in osteoblasts. Further, inhibition of autophagy with 3-MA ameliorated the severity of osteolysis in PIO animal models. Moreover, 3-MA also prevented osteoblast apoptosis in an antiautophagic way when tested in PIO model. Collectively, these results suggest that autophagy plays a key role in CoPs-induced osteolysis and that targeting autophagy-related pathways may represent a potential therapeutic approach for treating particle-induced peri-implant osteolysis. PMID:26566231

Emodin attenuates TNF-α-induced apoptosis and autophagy in mouse C2C12 myoblasts though the phosphorylation of Akt.