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1.
Tretiakova I Blaesius D Maxia L Wesselborg S Schulze-Osthoff K Cinatl J Michaelis M Werz O 《Apoptosis : an international journal on programmed cell death》2008,13(1):119-131
Myrtucommulone (MC) is a unique, nonprenylated acylphloroglucinol contained in the leaves of myrtle (Myrtus communis). Here, we addressed the potential of MC to induce apoptosis of cancer cells. MC potently induced cell death of different
cancer cell lines (EC50 3–8 μM) with characteristics of apoptosis, visualized by the activation of caspase-3, -8 and -9, cleavage of poly(ADP-ribose)polymerase
(PARP), release of nucleosomes into the cytosol, and DNA fragmentation. MC was much less cytotoxic for non-transformed human
peripheral blood mononuclear cells (PBMC) or foreskin fibroblasts (EC50 cell death = 20–50 μM), and MC up to 30 μM hardly caused processing of PARP, caspase-3, -8 and -9 in human PBMC. MC-induced
apoptosis was mediated by the intrinsic rather than the extrinsic death pathway. Thus, MC caused loss of the mitochondrial
membrane potential in MM6 cells and evoked release of cytochrome c from mitochondria. Interestingly, Jurkat cells deficient
in caspase-9 were resistant to MC-induced cell death and no processing of PARP or caspase-8 was evident. In cell lines deficient
in either CD95 (Fas, APO-1) signalling, FADD or caspase-8, MC was still able to potently induce cell death and PARP cleavage.
Conclusively, MC induces apoptosis in cancer cell lines, with marginal cytotoxicity for non-transformed cells, via the mitochondrial
cytochrome c/Apaf-1/caspase-9 pathway.
I. Tretiakova and D. Blaesius contributed equally to this work. 相似文献
2.
Bhushan S Kumar A Malik F Andotra SS Sethi VK Kaur IP Taneja SC Qazi GN Singh J 《Apoptosis : an international journal on programmed cell death》2007,12(10):1911-1926
A triterpenediol (TPD) comprising of isomeric mixture of 3α, 24-dihydroxyurs-12-ene and 3α, 24-dihydroxyolean-12-ene from
Boswellia serrata induces apoptosis in cancer cells. An attempt was made in this study to investigate the mechanism of cell death by TPD in
human leukemia HL-60 cells. It inhibited cell proliferation with IC50 ∼ 12 μg/ml and produced apoptosis as measured by various biological end points e.g. increased sub-G0 DNA fraction, DNA ladder
formation, enhanced AnnexinV-FITC binding of the cells. Further, initial events involved massive reactive oxygen species (ROS)
and nitric oxide (NO) formation, which were significantly inhibited by their respective inhibitors. Persistent high levels
of NO and ROS caused Bcl-2 cleavage and translocation of Bax to mitochondria, which lead to loss of mitochondrial membrane
potential (Δψm) and release of cytochrome c, AIF, Smac/DIABLO to the cytosol. These events were associated with decreased expression of
survivin and ICAD with attendant activation of caspases leading to PARP cleavage. Furthermore, TPD up regulated the expression
of cell death receptors DR4 and TNF-R1 level, leading to caspase-8 activation. These studies thus demonstrate that TPD produces
oxidative stress in cancer cells that triggers self-demise by ROS and NO regulated activation of both the intrinsic and extrinsic
signaling cascades. 相似文献
3.
Medicinal plants represent a rich source of cancer drug leads. Indioside D, a furostanol glycoside isolated from Solanum mammosum, was found to possess antiproliferative activity toward a panel of human cancer cell lines. Proteomic analysis of indioside D-treated HeLa cells revealed profound protein changes related to energy production and oxidative stress, suggesting that mitochondria dysfunction plays a role in indioside D-induced apoptosis. Indioside D caused a rapid dissipation of mitochondrial transmembrane potential (DeltaPsim) and the generation of reactive oxygen species (ROS), leading to the activation of caspase-dependent apoptotic cell death. The Fas death receptor pathway was also activated following indioside D treatment, and triggered the activation of caspase-8 and cleavage of Bid, which also acted through the mitochondrial apoptosis pathway. These results suggest that indioside D induced apoptosis in HeLa cells via both intrinsic and extrinsic cell death pathways. 相似文献
4.
Lubomir Prochazka Lan-Feng Dong Karel Valis Ruth Freeman Stephen J. Ralph Jaroslav Turanek Jiri Neuzil 《Apoptosis : an international journal on programmed cell death》2010,15(7):782-794
Mitocans are drugs selectively killing cancer cells by destabilizing mitochondria and many induce apoptosis via generation
of reactive oxygen species (ROS). However, the molecular events by which ROS production leads to apoptosis has not been clearly
defined. In this study with the mitocan α-tocopheryl succinate (α-TOS) the role of the Bcl-2 family proteins in the mechanism
of malignant cell apoptosis has been determined. Exposure of several different cancer cell lines to α-TOS increased expression
of the Noxa protein, but none of the other proteins of the Bcl-2 family, an event that was independent of the cellular p53
status. α-TOS caused a profound conformational change in the pro-apoptotic protein, Bak, involving oligomerization in all
cell types, and this also applied to the Bax protein, but only in non-small cell lung cancer cells. Immunoprecipitation studies
indicated that α-TOS activates the two BH1-3 proteins, Bak or Bax, to form high molecular weight complexes in the mitochondria.
RNAi knockdown revealed that Noxa and Bak are required for α-TOS-induced apoptosis, and the role of Bak was confirmed using
Bak- and/or Bax-deficient cells. We conclude that the major events induced by α-TOS in cancer cells downstream of ROS production
leading to mitochondrial apoptosis involve the Noxa-Bak axis. It is proposed that this represents a common mechanism for mitochondrial
destabilization activated by a variety of mitocans that induce accumulation of ROS in the early phases of apoptosis. 相似文献
5.
Sulforaphane-induced cell death in human prostate cancer cells is initiated by reactive oxygen species 总被引:17,自引:0,他引:17
Singh SV Srivastava SK Choi S Lew KL Antosiewicz J Xiao D Zeng Y Watkins SC Johnson CS Trump DL Lee YJ Xiao H Herman-Antosiewicz A 《The Journal of biological chemistry》2005,280(20):19911-19924
We have shown previously that sulforaphane (SFN), a constituent of many edible cruciferous vegetables including broccoli, suppresses growth of prostate cancer cells in culture as well as in vivo by causing apoptosis, but the sequence of events leading to cell death is poorly defined. Using PC-3 and DU145 human prostate cancer cells as a model, we now demonstrate, for the first time, that the initial signal for SFN-induced apoptosis is derived from reactive oxygen species (ROS). Exposure of PC-3 cells to growth-suppressive concentrations of SFN resulted in ROS generation, which was accompanied by disruption of mitochondrial membrane potential, cytosolic release of cytochrome c, and apoptosis. All these effects were significantly blocked on pretreatment with N-acetylcysteine and overexpression of catalase. The SFN-induced ROS generation was significantly attenuated on pretreatment with mitochondrial respiratory chain complex I inhibitors, including diphenyleneiodonium chloride and rotenone. SFN treatment also caused a rapid and significant depletion of GSH levels. Collectively, these observations indicate that SFN-induced ROS generation is probably mediated by a nonmitochondrial mechanism involving GSH depletion as well as a mitochondrial component. Ectopic expression of Bcl-xL, but not Bcl-2, in PC-3 cells offered significant protection against the cell death caused by SFN. In addition, SFN treatment resulted in an increase in the level of Fas, activation of caspase-8, and cleavage of Bid. Furthermore, SV40-immortalized mouse embryonic fibroblasts (MEFs) derived from Bid knock-out mice displayed significant resistance toward SFN-induced apoptosis compared with wild-type MEFs. In conclusion, the results of the present study indicate that SFN-induced apoptosis in prostate cancer cells is initiated by ROS generation and that both intrinsic and extrinsic caspase cascades contribute to the cell death caused by this highly promising cancer chemopreventive agent. 相似文献
6.
Byeong Mo Kim Yun Jung Choi Yong Heon Lee Young Ae Joe Sung Hee Hong 《Apoptosis : an international journal on programmed cell death》2010,15(8):982-993
Doxorubicin (Dox) is widely used to treat a variety of tumors. However, resistance to this drug is common, making successful
treatment more difficult. Previously, we introduced a novel phytosphingosine derivative, N,N-dimethyl phytosphingosine (DMPS), as a potent anticancer therapeutic agent in human leukemia cells. This study was performed
to investigate whether DMPS can sensitize HL-60/MX2, a multidrug-resistant variant of HL-60, to Dox-induced apoptosis. Low
concentrations of DMPS sensitized HL-60/MX2 cells to Dox-induced apoptosis. Combined Dox + DMPS treatment-induced apoptosis
was accompanied by the activation of caspase-8 and caspase-3 as well as PARP cleavage. Cytochrome c and AIF release were also observed in Dox + DMPS-treated HL60/MX2 cells. Pretreatment with z-VAD-fmk markedly prevented caspase-3
activation and moderately suppressed apoptosis, suggesting that Dox + DMPS-induced apoptosis is somewhat (not completely)
dependent on caspase. Cytochrome c and AIF release were not affected by pretreatment with z-VAD-fmk. The ROS scavenger NAC efficiently suppressed not only ROS
generation, but also caspase-3-mediated PARP cleavage, apoptosis, and release of cytochrome c and AIF, indicating a role of ROS in combined Dox + DMPS treatment-induced apoptotic death signaling. Taken together, these
observations suggest that DMPS may be used as a therapeutic agent for overcoming drug-resistance in cancer cells by enhancing
drug-induced apoptosis. 相似文献
7.
Nottrott S Schoentaube J Genth H Just I Gerhard R 《Apoptosis : an international journal on programmed cell death》2007,12(8):1443-1453
Clostridium difficile toxin A (TcdA) is one of two homologous glucosyltransferases that mono-glucosylate Rho GTPases. HT29 cells were challenged
with wild-type and mutant TcdA to investigate the mechanism by which apoptosis is induced. The TcdA-induced re-organization
of the actin cytoskeleton led to an increased number of cells within the G2/M phase. Depolymerization of the actin filaments
with subsequent G2/M arrest, however, was not causative for apoptosis, as shown in a comparative study using latrunculin B.
The activation of caspase-3, -8, and -9 strictly depended on the glucosylation of Rho GTPases. Apoptosis measured by flow
cytometry was completely abolished by a pan-caspase inhibitor (z-VAD-fmk). Interestingly, cleavage of procaspase-3 and Bid
was not inhibited by z-VAD-fmk, but was inhibited by the calpain/cathepsin inhibitor ALLM. Cleavage of procaspase-8 was susceptible
to inhibition by z-VAD-fmk and to the caspase-3 inhibitor Ac-DMQD-CHO, indicating a contribution to the activation of caspase-3
in an amplifying manner. Although TcdA induced mitochondrial damage and cytochrome c release, p53 was not activated or up-regulated. A p53-independent apoptotic effect was also checked by treatment of HCT 116
p53−/− cells. In summary, TcdA-induced apoptosis in HT29 cells depends on glucosylation of Rho GTPases leading to activation of
cathepsins and caspase-3. 相似文献
8.
This report is designed to explore the molecular mechanism by which dihydroartemisinin (DHA) and ionizing radiation (IR) induce apoptosis in human lung adenocarcinoma A549 cells. DHA treatment induced a concentration- and time-dependent reactive oxygen species (ROS)-mediated cell death with typical apoptotic characteristics such as breakdown of mitochondrial membrane potential (Δψm), caspases activation, DNA fragmentation and phosphatidylserine (PS) externalization. Inhibition of caspase-8 or -9 significantly blocked DHA-induced decrease of cell viability and activation of caspase-3, suggesting the dominant roles of caspase-8 and -9 in DHA-induced apoptosis. Silencing of proapoptotic protein Bax but not Bak significantly inhibited DHA-induced apoptosis in which Bax but not Bak was activated. In contrast to DHA treatment, low-dose (2 or 4 Gy) IR induced a long-playing generation of ROS. Interestingly, IR treatment for 24 h induced G2/M cell cycle arrest that disappeared at 36 h after treatment. More importantly, IR synergistically potentiated DHA-induced generation of ROS, activation of caspase-8 and -3, irreparable G2/M arrest and apoptosis, but did not enhance DHA-induced loss of Δψm and activation of caspase-9. Taken together, our results strongly demonstrate the remarkable synergistic efficacy of combination treatment with DHA and low-dose IR for A549 cells in which IR potentiates DHA-induced apoptosis largely by enhancing the caspase-8-mediated extrinsic pathway. 相似文献
9.
Kim BM Rode AB Han EJ Hong IS Hong SH 《Apoptosis : an international journal on programmed cell death》2012,17(2):200-216
In the present study, we investigated the signaling pathways implicated in the induction of apoptosis by two modified nucleosides,
5-phenylselenyl-methyl-2′-deoxyuridine (PhSe-T) and 5-methylselenyl-methyl-2′-deoxyuridine (MeSe-T), using human cancer cell
lines. The induction of apoptosis was associated with proteolytic activation of caspase-3 and -9, PARP cleavage, and decreased
levels of IAP family members, including c-IAP-1 and c-IAP-2, but had no effect on XIAP and survivin. PhSe-T and MeSe-T also
enhanced the activities of caspase-2 and -8, Bid cleavage, and the conformational activation of Bax. Additionally, nucleoside
derivative-induced apoptosis was inhibited by the selective inhibitors of caspase-2, -3, -8, and -9 and also by si-RNAs against
caspase-2, -3, -8, and -9; however, inhibition of caspase-2 and -3 was more effective at preventing apoptosis than inhibition
of caspase-8 and -9. Moreover, the inhibition of caspase-2 activation by the pharmacological inhibitor z-VDVAD-fmk or by the
knockdown of protein expression using siRNA suppressed nucleoside derivative-induced caspase-3 activation, but not vice versa.
PhSe-T and MeSe-T also induced a Δψm loss via a CsA-insensitive mechanism, ROS production, and DNA damage, including strand breaks. Moreover, ROS scavengers such
as NAC, tiron, and quercetin inhibited nucleoside derivative-induced ROS generation and apoptosis by blocking the sequential
activation of caspase-2 and -3, indicating the role of ROS in caspase-2-mediated apoptosis. Taken together, these results
indicate that caspase-2 acts upstream of caspase-3 and that caspase-2 functions in response to DNA damage in both PhSe-T-
and MeSe-T-induced apoptosis. Our results also suggest that ROS are critical regulators of the sequential activation of caspase-2
and -3 in nucleoside derivative-treated cancer cells. 相似文献
10.
Rajdeep Chowdhury Suchandra Chowdhury Paromita Roychoudhury Chitra Mandal Keya Chaudhuri 《Apoptosis : an international journal on programmed cell death》2009,14(1):108-123
Introduction Resistance to apoptosis is a prominent feature of melanoma. Pharmacological concentration of arsenic in combination with a
widely known oxidant, menadione was explored in this study to synergistically sensitize malignant melanoma cells to apoptosis.
The molecular mechanism of apoptosis and the signaling-pathways involved were thoroughly investigated.
Materials methods and results Menadione synergized NaAsO2 to significantly increase ROS generation and facilitate the major apoptotic signaling events: alteration of mitochondrial
membrane potential, cytochrome c release and anti-apoptotic protein Bcl-2 down-regulation and subsequent activation of caspase-9 and caspase-3 followed by
poly-ADP-ribose polymerase-1 cleavage. Antioxidant N-acetyl-l-cysteine antagonized these events. Investigation of the signaling-pathway revealed significant suppression of AP-1 activity
but not NF-κB upon NaAsO2 and menadione application. An increase in p38 phosphorylation and p53 protein expression did also dictate the apoptotic response.
Suppression of p38 activation with SB203580 and inhibition of p53 expression by siRNA attenuated apoptosis. Transfection of
p53, in p53 null HCT cells augmented the apoptotic events. Moreover, the treatment also led to tumor size reduction in BALB/c mice developed by intra-dermal B16 mouse melanoma cell injection; however, it had no detectable pro-proliferative or pro-apoptotic
effect on non-tumor keratinocytes, normal fibroblasts or PBMC.
Conclusion This study thus provides an insight into innovative mechanisms of melanoma sensitization, a proper cure against which is still
elusive. Taken together, our data also provides the first evidence of arsenic activity accentuation by menadione through modulation
of specific signaling-pathways. 相似文献
11.
Basma H El-Refaey H Sgagias MK Cowan KH Luo X Cheng PW 《Journal of biomedical science》2005,12(6):999-1011
Summary Chemotherapy has been used for treatment of breast cancer but with limited success. We characterized the effects of bcl-2
antisense and cisplatin combination therapy in two human isogenic breast carcinoma cells p53(+)MCF-7 and p53(−)MCF-7/E6. The
transferrin-facilitated lipofection strategy we have developed yielded same transfection efficiency in both cells. Bcl-2 antisense
delivered with this strategy significantly induced more cell death, apoptosis, and cytochrome c release in MCF-7/E6 than in MCF-7, but did not affect Fas level in both cells and activated caspase-8 equally. Cisplatin
exerted same effects on cell viability and apoptosis in both cells, but released smaller amounts of cytochrome c while activated more caspase-8 in MCF-7/E6. The combination treatment yielded greater effects on cell viability, apoptosis,
cytochrome c release, and caspase-8 activation than individual treatments in both cells although p53(−) cells were more sensitive. The
potentiated activation of caspase-8 in the combination treatment suggested that caspase-8-mediated (but cytochrome c-independent) apoptotic pathway is the major contributor of the enhanced cell killing. Thus, bcl-2 antisense delivered with
transferrin-facilitated lipofection can achieve the efficacy of killing breast cancer cells and sensitizing them to chemotherapy.
Bcl-2 antisense and cisplatin combination treatment is a potentially useful therapeutic strategy for breast cancer irrespective
of p53 status.
Hesham Basma and Hesham El-Refaey contributed equally 相似文献
12.
Chubiao Zhao Weijie Gao Tongsheng Chen 《Apoptosis : an international journal on programmed cell death》2014,19(4):668-681
This report is designed to study the ability of the combined treatment with gemcitabine (Gem) and dihydroartemisinin (DHA) to induce apoptosis in a non-small-cell lung cancer cell line (A549 cells). This combination treatment synergistically inhibited cell growth by inducing apoptosis, and this synergistic action was not associated with reactive oxygen species (ROS). Although either Gem or DHA induced a significant increase in ROS generation, the combination treatment did not further enhance ROS level. Compared with single drugs, the combination treatment significantly potentiated Bak activation, loss of mitochondrial membrane potential, caspase-9 and -3 activation, indicating the important role of the Bak-mediated intrinsic apoptosis pathway in the synergistic action, which was further verified by the significant prevention of the cytotoxicity of the combination treatment by inhibiting one of caspase-9, -3 and Bcl-xL or silencing Bak. In addition, the combination treatment also synergistically activated caspase-8, and inhibition of Fas and caspase-8 presented significant prevention on the cytotoxicity of the combination treatment, indicating that the Fas-caspase-8-mediated extrinsic apoptosis pathway partially participated in the synergistic action. Collectively, the present study demonstrates a strong synergistic action of the combined treatment with Gem and DHA in inducing apoptosis of A549 cells via both the Bak-mediated intrinsic pathway and the Fas-caspase-8-mediated extrinsic pathway. 相似文献
13.
Partial attenuation of cytotoxicity and apoptosis by SOD1 in ischemic renal epithelial cells 总被引:1,自引:0,他引:1
Huan Ling Liang Jody Arsenault Jordan Mortensen Frank Park Christopher P. Johnson Vani Nilakantan 《Apoptosis : an international journal on programmed cell death》2009,14(10):1176-1189
Reactive oxygen species (ROS) contribute significantly to apoptosis in renal ischemia-reperfusion (IR) injury, however the
exact mechanisms are not well understood. We used novel lentiviral vectors to over-express superoxide dismutase 1 (SOD1) in
proximal tubular epithelial (LLC-PK1) cells and determined effects of SOD1 following ATP depletion-recovery, used as a model to simulate renal IR. SOD1 over-expression
partially protected against cytotoxicity (P < 0.001) and decreased superoxide (O2
•−) in ATP depleted cells. The ATP depletion-mediated increase in nuclear fragmentation, an index of apoptosis and activation
of caspase-3 was also partially blocked by SOD1 (P < 0.05). However, SOD1 over-expression was insufficient to completely attenuate caspase-3, indicating that ROS other than
cytoplasmic O2
•− are involved in ATP depletion mediated injury. To test the contribution of hydrogen peroxide, a subset of enhanced green
fluorescent protein (EGFP) and SOD1 (serum free and injured) cells were treated with polyethylene glycol-catalase (PEG-catalase).
As expected there was 50% reduction in cytotoxicity and caspase-3 in SOD1 cells compared to EGFP cells; catalase treatment
decreased both indices by an additional 28% following ATP depletion. To test the role of mitochondrial derived superoxide,
we also treated a subset of LLC-PK1 cells with the mitochondrial antioxidant, MitoTEMPO. Treatment with MitoTEMPO also decreased ATP depletion induced cytotoxicity
in LLC-PK1 cells in a dose dependant manner. These studies indicate that both SOD1 dependent and independent pathways are integral in
protection against ATP depletion-recovery mediated cytotoxicity and apoptosis, however more studies are needed to delineate
the signaling mechanisms involved. 相似文献
14.
Guang-quan Li Xing-gui Chen Xing-ping Wu Jing-dun Xie Yong-ju Liang Xiao-qin Zhao Wei-qiang Chen Li-wu Fu 《PloS one》2012,7(11)
Dicycloplatin, a new supramolecular platinum-based antitumor drug, has been approved by the State Food and Administration (SFDA) of China. In this study, we investigated the anticancer activity of dicycloplatin in cancer cells and signaling pathways involved in dicycloplatin-induced apoptosis. Dicycloplatin inhibited the proliferation of cancer cells and increased the percentage of apoptosis in a concentration-dependent manner. Besides, some apoptosis related events were observed after treatment with dicycloplatin, including increase of reactive oxygen species (ROS), collapse of mitochondrial membrane potential (Δψm), release of cytochrome c from the mitochondria to the cytosol, upregulation of p53, which were accompanied by activation of caspase-9, caspase-3, caspase-8, and poly (ADP-ribose) polymerase cleavage in a concentration-dependent manner. The role of apoptosis in dicycloplatin-mediated cell death was further confirmed by the concomitant treatment with caspase-8 or caspase-9 inhibitors, which inhibited apoptosis and PARP cleavage. Intracellular glutathione (GSH) was also found to inhibit the cytotoxic effect of dicycloplatin. In conclusion, these findings suggest that dicycloplatin induces apoptosis through ROS stress-mediated death receptor pathway and mitochondrial pathway which is similar to carboplatin. 相似文献
15.
Xiao-hong Cao Si-si Zhao Dong-yue Liu Zhuo Wang Li-li Niu Li-hua Hou Chun-ling Wang 《Chemico-biological interactions》2011,(1):16
The surfactin can inhibit proliferation and induce apoptosis in cancer cells. Moreover, surfactin can induce cell death in human breast cancer MCF-7 cells through mitochondrial pathway. However, the molecular mechanism involved in this pathway remains to be elucidated. Here, the reactive oxygen species (ROS) and Ca2+ on mitochondria permeability transition pore (MPTP) activity, and MCF-7 cell apoptosis which induced by surfactin were investigated. It is found that surfactin evoked mitochondrial ROS generation, and the surfactin-induced cell death was prevented by N-acetylcysteine (NAC, an inhibitor of ROS). An increasing cytoplasmic Ca2+ concentration was detected in surfactin-induced MCF-7 apoptosis, which was inhibited by 1,2-bis (2-aminophenoxy) ethane-N,N,N′,N′-tetraacetic acid (BAPTA-AM, a chelator of calcium). In addition, the relationship between ROS generation and the increase of cytoplasm Ca2+ was determined. The results showed that surfactin initially induced the ROS formation, leading to the MPTP opening accompanied with the collapse of mitochondrial membrane potential (ΔΨm). Then the cytoplasmic Ca2+ concentration increased in virtue of the changes of mitochondrial permeability, which was prevented by BAPTA-AM. Besides, cytochrome c (cyt c) was released from mitochondria to cytoplasm through the MPTP and activated caspase-9, eventually induced apoptosis. In summary, surfactin has notable anti-tumor effect on MCF-7 cells, however, there was no obvious cytotoxicity on normal cells. 相似文献
16.
The Role of Ca2+ on the DADS-induced Apoptosis in Mouse–Rat Hybrid Retina Ganglion Cells (N18) 总被引:2,自引:0,他引:2
Diallyl disulfide (DADS), a component of garlic, has been shown to induce growth inhibition and apoptosis in human cancer cell types. The present studies were designed to investigate the effects of DADS on mouse–rat hybrid retina ganglion cells (N18) to better understand its effect on apoptosis and apoptosis-related genes in vitro. Cell viability, cell cycle analysis, reactive oxygen species (ROS), Ca2+ production, mitochondria membrane potential, apoptosis induction, associated gene expression and caspases-3 activity were examined by flow cytometric assay and/or Western blot. After 24-h treatment with DADS, a dose- and time-dependent decrease in the viability of N18 cells was observed and the approximate IC50 was 27.6 μM. The decreased percentage of viable cells are associated with the production of ROS then followed by the production of Ca2+ which is induced by DADS. DADS induced apoptosis in N18 cells via the activation of caspase-3. DADS increased the protein levels of p53, cytochrome c and phosphated JNK within 24 h of treatment and it decreased the levels of Bcl-2 and those factors may have led to the mitochondria depolarization of N18 cells. DADS induced apoptosis were accompanied by increased levels of Ca2+ and decreased mitochondrial membrane potential which then led to release the cytochrome c, cleavage of pro-caspase-3. Deleted levels of Ca2+ by BAPTA-AM 10 μM (intracellular calcium chelator) then led to decrease DADS-induced apoptosis. Inhibition of caspase-3 activation by inhibitor (z-VAD-fmk) completely blocked DADS-induced apoptosis on N18 cells. The results indicated that oxidative stress modulates cell proliferation and Ca2+ modulates the cell death induced by DADS. 相似文献
17.
Kanwal Ahmed Hideo Nemoto Toshiro Sugiyama Tadamichi Shimizu 《Chemico-biological interactions》2009,177(3):218-7685
The apoptosis-inducing ability of hybrid compounds composed of macrosphelide and thiazole-containing side chain of epothilones was investigated. Among the tested series of hybrid compounds the one containing thiazole side chain at C15 (MSt-2) showed the maximum potency to induce apoptosis, while another containing thiazole side chain at C3 (MSt-6) was less potent. MSt-2 was found to induce apoptosis in human lymphoma (U937) cells in a dose- and time-dependent manner as confirmed by DNA fragmentation analysis. MSt-2 treated cells showed rapid reactive oxygen species (ROS) formation and c-Jun N-terminal kinase (JNK) activation. Furthermore, significant activation of extrinsic pathway as evident by Fas expression and caspase-8 activation was also observed. MSt-2-mediated decreased expression of Bid is an important event for cross talk between intrinsic and extrinsic signaling. N-acetyl-l-cysteine pre-treatment rescued cells from MSt-2-induced ROS formation, mitochondrial membrane potential (Δψm) loss, Fas expression, caspase-8 and -3 activation and DNA fragmentation. Moreover, antioxidant enzymes catalase and/or superoxide dismutase conjugated with polyethylene glycol also inhibit MSt-2-induced ROS formation, apoptosis and Δψm loss suggesting thereby pro-oxidant effects of MSt-2. Furthermore, JNK and pan-caspase inhibitors also protect cells from MSt-2-induced apoptosis. In addition to this, MSt-2 was found to be more potent in human colon carcinoma (HCT116) and human gastric cancer (AGS) cells while it has no effect on human normal dermal fibroblast. The important structure-activity relationship observed in the current study which makes MSt-2 more potent than MSt-6 is the position of thiazole side chain and stereochemistry of position 3 in chemical structure. In short the results of our study demonstrate that MSt-2-induced rapid ROS generation and mitochondrial dysfunction in cells trigger events responsible for mitochondria-dependent apoptosis pathway. 相似文献
18.
Guo M Song LP Jiang Y Liu W Yu Y Chen GQ 《Apoptosis : an international journal on programmed cell death》2006,11(1):67-77
Hypoxia presents pro-apoptotic and anti-apoptotic biphasic effects that appear to be dependent upon cell types and conditions
around cells. The substantial reports demonstrated that commonly used hypoxia-mimetic agents cobalt chloride (CoCl2) and desferrioxamine (DFO) could also induce apoptosis in many different kinds of cells, but the mechanism was poorly understood.
In this work, we compare the apoptosis-inducing effects of these two hypoxia-mimetic agents with acute myeloid leukemic cell
lines NB4 and U937 as in vitro models. The results show that both of them induce these leukemic cells to undergo apoptosis with a loss of mitochondrial
transmembrane potentials (ΔΨ m), the activation of caspase-3/8 and the cleavage of anti-apoptotic protein Mcl-1, together
with the accumulation of hypoxia-inducible factor-1 alpha (HIF-1α) protein, a critical regulator for the cellular response
to hypoxia. Metavanadate and sodium nitroprusside significantly abrogate DFO rather than CoCl2-induced mitochondrial Δ Ψ m collapse, caspase-3/8 activation, Mcl-1 cleavage and apoptosis, but they fail to influence DFO
and CoCl2-induced HIF-1α protein accumulation. Moreover, inducible expression of HIF-1α gene dose not alter DFO and CoCl2-induced apoptosis in U937 cells. In conclusion, these results propose that although both DFO and CoCl2-induced leukemic cell apoptosis by mitochondrial pathway-dependent and HIF-1α-independent mechanisms, DFO and CoCl2-induced apoptosis involves different initiating signal pathways that remain to be investigated. 相似文献
19.
S. K. Arepalli V. Sridhar J. Venkateswara Rao P. Kavin Kennady Y. Venkateswarlu 《Apoptosis : an international journal on programmed cell death》2009,14(5):729-740
Bioassay directed fractionation and purification led to the successful isolation of a furano sesquiterpene, Methyl 5-[(1E,5E)-2,6-Dimethyl
octa-1,5,7-trienyl] furan-3-carboxylate (MDTFC), a bioactive component from a soft coral, Sinularia kavarittiensis. Its structure was determined by analyzing 1H, 13C NMR and FAB-MS. The results show that MDTFC could efficiently and selectively inhibit the proliferation of several human
cancer cell lines. Among all the cell lines, THP-1 was found to be most sensitive (IC50 29.59 μM), whereas the peripheral blood mononuclear cells were least effected (IC50 464.16 μM). The molecular mechanism of MDTFC mediated apoptosis was investigated for the first time. Induction of apoptosis
in THP-1 cells was characterized by cell membrane blebbing, chromatin condensation, DNA fragmentation, and decrease in level
of pro-caspases 3, 9 and increase in Bax/Bcl-2 ratio. Our results were further strengthened through cleavage of poly (ADP-ribose)
polymerase, reduction of mitochondrial membrane potential (Ψm) and cytosolic release of cytochrome c, which are key events during apoptosis. Moreover, phosphatidyl serine exposure and appearance of sub-G1 peak also demonstrated
cell death, when analyzed by flow cytometry. DNA fragmentation was prevented moderately when pretreated with caspase-9 inhibitor
(Z-LEHD-FMK) and largely with caspase-3 inhibitor (Z-DEVD-FMK). In summary, MDTFC mediated apoptosis involves mitochondria-dependent
pathway and the present compound of marine origin might have a therapeutic value against human cancer cell lines and especially
on leukemia cells. 相似文献
20.
Di Wu Yana Zhao Shengnan Fu Jianbo Zhang Wenhang Wang Zhexian Yan 《Cell cycle (Georgetown, Tex.)》2018,17(13):1579-1590
Seleno-short-chain chitosan (SSCC) was a synthesized chitosan derivative with the molecular weight of 4826.986 Da. The study is aimed to investigate cytotoxicity of SSCC on human breast cancer MCF-7 and BT-20 cells and explore apoptosis-related mechanism in vitro. The MTT (3- [4,5-Dimethylthiazol-2-yl]-2, 5-diphenylterazolium bromide) assay showed that SSCC exhibited significantly cytotoxic effects on MCF-7 and BT-20 cells in a dose- and time-dependent manner, and the effective inhibitory concentration was 100 μg/ml and 200 μg/ml, respectively. Apoptosis assay of these two kinds of cells was determined by Hoechst 33,342/PI and Annexin V-FITC/PI double staining. The cell cycle assay showed that SSCC triggered S and G2/M phase cell cycle arrest in MCF-7 cells and S phase cell cycle arrest in BT-20 cells in a time-dependent manner. Further studies demonstrated that SSCC led to the generation of reactive oxygen species (ROS) and the disruption of mitochondrial membrane potential (MMP) in these two kinds of cells. N- acetyl-L cysteine (NAC), as a radical scavenger, significantly inhibited the generation of ROS and decreased the apoptosis of MCF-7 and BT-20 cells. Moreover, the expression of mitochondrial apoptosis-related proteins was detected by western blot assay. SSCC up-regulated the expression of Bax, down-regulated the expression of Bcl-2, subsequently increased the release of cytochrome c from mitochondria to cytoplasm, and activated the cleavage of caspase-9 and ?3, which finally induced apoptosis in MCF-7 and BT-20 cells in vitro. Consequently, these data indicated that SSCC could induce apoptosis of MCF-7and BT-20 cells in vitro by mitochondrial pathway. 相似文献