Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P42574 (caspase-3)
 45,978 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Reactive oxygen species (ROS) and resultant oxidative damage is a common pathway for gastric mucosal injury. This study was undertaken to determine whether apoptosis or necrosis was responsible for hydrogen peroxide (a representative ROS)-induced gastric mucosal death and whether caspase cascade blockade could prevent this process. AGS cells (human gastric adenocarcinoma cells) were exposed to hydrogen peroxide (H(2)O(2)), 0.5-2 mM, from 6 to 24 h. Lactic dehydrogenase (LDH) measured necrosis, whereas Caspase-3 and PARP activation and DNA-histone complex formation measured apoptosis. In addition, AGS cells received no pretreatment or preincubation for 1 h with 50-100 microM z-VAD, a pan-caspase inhibitor, and were then treated with 1-2 mM H(2)O(2). With high concentrations of H(2)O(2), cell death was predominantly necrotic, whereas lower concentrations evoked time and concentration dependent apoptosis. Furthermore, z-VAD pretreatment prevented oxidant induced apoptosis and necrosis. Since caspase cascade blockade prevents both processes, our results support the hypothesis that H(2)O(2) induced cell death is predominantly a caspase-mediated apoptosis.
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PMID:Oxygen radical induced gastric mucosal cell death: apoptosis or necrosis? 1825 65

Diphenyl difluoroketone (EF24), a molecule having structural similarity to curcumin, was reported to inhibit proliferation of a variety of cancer cells in vitro. However, the efficacy and in vivo mechanism of action of EF24 in gastrointestinal cancer cells have not been investigated. Here, we assessed the in vivo therapeutic effects of EF24 on colon cancer cells. Using hexosaminidase assay, we determined that EF24 inhibits proliferation of HCT-116 and HT-29 colon and AGS gastric adenocarcinoma cells but not of mouse embryo fibroblasts. Furthermore, the cancer cells showed increased levels of activated caspase-3 and increased Bax to Bcl-2 and Bax to Bcl-xL ratios, suggesting that the cells were undergoing apoptosis. At the same time, cell cycle analysis showed that there was an increased number of cells in the G(2)-M phase. To determine the effects of EF24 in vivo, HCT-116 colon cancer xenografts were established in nude mice and EF24 was given i.p. EF24 significantly suppressed the growth of colon cancer tumor xenografts. Immunostaining for CD31 showed that there was a lower number of microvessels in the EF24-treated animals coupled with decreased cyclooxygenase-2, interleukin-8, and vascular endothelial growth factor mRNA and protein expression. Western blot analyses also showed decreased AKT and extracellular signal-regulated kinase activation in the tumors. Taken together, these data suggest that the novel curcumin-related compound EF24 is a potent antitumor agent that induces caspase-mediated apoptosis during mitosis and has significant therapeutic potential for gastrointestinal cancers.
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PMID:Diphenyl difluoroketone: a curcumin derivative with potent in vivo anticancer activity. 1833 78

To investigate the anti-proliferative and chemosensitizing effects of luteolin on human gastric cancer, gastric cancer AGS cells were treated with luteolin and/or other chemotherapeutic agents. Cell growth was assessed by MTT assay, cell cycle and apoptosis were assessed by flow-cytometric analysis, and the expression of major proteins regulating cell cycle and apoptosis was also detected. The results showed that luteolin inhibited the growth of gastric cancer cells in a dose- and time-dependent manner. Flow cytometry revealed that the percentage of cells at G2/M phase increased dose-dependently. The protein levels of Cdc2, Cyclin B1 and Cdc25C were reduced and p21/cip1 was up-regulated after the treatment with luteolin. Furthermore, luteolin induced apoptosis in gastric cancer AGS cells. Western blotting showed that luteolin treatment significantly increased the levels of pro-apoptotic proteins, including Caspase-3, 6, 9, Bax, and p53, and decreased the levels of anti-apoptotic protein Bcl-2, thus shifting the Bax/Bcl ratio in favor of apoptosis. It was also demonstrated that a combinational treatment of cisplatin and luteolin induced more effectively cell growth inhibition, compared to cisplatin treatment alone. These findings indicate the anti-proliferative and chemosensitizing effects of luteolin on human gastric cancer AGS cells and luteolin may be a promising candidate agent used in the treatment of gastric cancer.
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PMID:Anti-proliferative and chemosensitizing effects of luteolin on human gastric cancer AGS cell line. 1839 71

The seed of Strychnos nux-vomica (Loganiaceae) has been used in traditional Oriental medicine as a folk remedy for the treatment of cancer. However, the mechanism responsible for the anticancer effects of Strychni Semen is not clearly understood. The study tested whether and how the water extract of Strychni Semen (ESS) treatment would affect the growth of AGS human gastric carcinoma cells. ESS was found to inhibit the growth of AGS cells in a concentration-dependent manner. Cell cycle analysis showed G2/M phase arrest and apoptosis in AGS cells following ESS treatment. ESS-mediated G2/M arrest was found to be associated with up-regulation of cyclin A, Cdc2, tumor suppressor p53 and cyclin dependent kinase (Cdk) inhibitor p21(WAF1/CIP1), whereas the expressions of other G2/M regulatory proteins, including cyclin B1 and Cdk2, were down-regulated compared with the control. The induction of apoptotic cell death by ESS was associated with down-regulation of anti-apoptotic Bcl-2 and up-regulation of pro-apoptotic Bax expression. Further results indicate that caspase-3, caspase-8 and caspase-9 are all activated by ESS, together with cleavage of downstream caspase-3 target proteins. Taken together, the results of this study suggest the involvement of multiple signaling pathways targeted by ESS in mediating G2/M cell cycle arrest and apoptosis in AGS cells, and warrant further investigation.
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PMID:Induction of G2/M arrest and apoptosis by water extract of Strychni Semen in human gastric carcinoma AGS cells. 1844 45

Gastric cancer is an aggressive cancer with poor prognosis. Identification of precise prognostic marker and effective therapeutic target is important in the treatment of gastric cancer. TIP30, a newly identified tumor suppressor, appears to be involved in multiple functions including tumorigenic suppression, apoptosis induction and diminishing angiogenic properties. Here, the level of TIP30 expression was determined in gastric cancer, and the impact of its alteration on cancer biology and clinical outcome was investigated. We found that TIP30 protein was absent or reduced in gastric cancer cell lines. There was also a loss or substantial decrease of TIP30 expression in 106 cases of gastric tumors as compared with that in normal gastric mucosa (p<0.05), which was significantly associated with inferior survival duration. In a Cox proportional hazards model, TIP30 expression independently predicted better survival (p<0.05). We also restored TIP30 protein expression in human gastric cancer-derived cells AGS and MKN28 lacking endogenous TIP30 protein to study the effects of TIP30 expression on cell proliferation, cell kinetics, tumorigenicity and metastasis in BALB/c nude mice and found that adenoviral-mediated restoration of TIP30 expression led to downregulation of cyclin D1, Bcl-2, Bcl-xl, but to upregulation of p27, Bax, p53, caspase 3 and 9 expression, cell cycle G0/G1 arrest and apoptosis in vitro, and dramatic attenuation of tumor growth and abrogation of metastasis in animal models. Taken together, the present work revealed a novel function of TIP30, which can possibly be used as an independent prognostic factor and a potential therapeutic target for gastric cancer.
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PMID:Reduction of TIP30 correlates with poor prognosis of gastric cancer patients and its restoration drastically inhibits tumor growth and metastasis. 1897 34

Interferon regulatory factor-1 (IRF-1) is a transcription factor that acts as a tumor suppressor and causes apoptosis in cancer cells. We evaluated IRF-1-induced apoptosis in gastric cancer cell lines. We established stable clones in AGS cells that have a tetracycline-inducible IRF-1 expression system. We used these clones and recombinant adenovirus expressing IRF-1 to explore the mechanism of IRF-1-induced apoptosis in gastric cancer. Expression of IRF-1 causes apoptosis in gastric cancer cell lines as shown by phosphatidylserine exposure and cleavage of caspase-8, caspase-3, and Bid with the mitochondrial release of cytochrome c. However, inhibition of caspase-8 and Bid did not inhibit apoptosis and did not decrease cleaved caspase-9 or mitochondrial release of cytochrome c. We then show that IRF-1 upregulates PUMA (p53 upregulated modulator of apoptosis), which is known to activate apoptosis by the intrinsic pathway; this can be p53-independent. IRF-1 binds to distinct sites in the promoter of PUMA and activates PUMA transcription. Moreover, molecular markers of mitochondrial apoptosis are eliminated in PUMA knockout and knockdown cells and phosphatidylserine exposure is decreased dramatically. Finally, we show that IFN-gamma induces IRF-1-mediated upregulation of PUMA in cancer cells. We conclude that IRF-1 can induce apoptosis by the intrinsic pathway independent of the extrinsic pathway by upregulation of PUMA.
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PMID:IRF-1 transcriptionally upregulates PUMA, which mediates the mitochondrial apoptotic pathway in IRF-1-induced apoptosis in cancer cells. 1985 30

Sanguinarine is a benzophenanthridine alkaloid, derived from the root of Sanguinaria canadensis and other poppy Fumaria species, which is known to have antimicrobial, antiinflammatory and antioxidant properties. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is known to induce apoptosis in cancer cells but spare most normal cells. However, its effects are limited in some types of cancer cells, including AGS human gastric adenocarcinoma cells. In the present study, we showed that treatment with TRAIL in combination with subtoxic concentrations of sanguinarine sensitized TRAIL-mediated apoptosis in AGS cells. Combined treatment with sanguinarine and TRAIL effectively induced Bid cleavage and loss of mitochondrial membrane potential, leading to the activation of caspases, and cleavage of poly(ADP-ribose) polymerase and beta-catenin. The cytotoxic effects of the combined treatment were significantly inhibited by z-DEVD-fmk, a caspase-3 inhibitor, which demonstrates the important role of caspase-3 in the observed cytotoxic effect. In addition, the levels of Akt protein were markedly reduced in cells co-treated with sanguinarine and TRAIL. Apoptosis induced by the combined treatment was markedly increased by the phosphatidylinositol-3'-kinase inhibitor, LY294002 (Akt-upstream inhibitor), through the mitochondrial amplification step and caspase activation, suggesting that interactions of the synergistic effect were at least partially mediated through the Akt-dependent pathway.
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PMID:Sanguinarine sensitizes human gastric adenocarcinoma AGS cells to TRAIL-mediated apoptosis via down-regulation of AKT and activation of caspase-3. 2003 92

Nicotine is shown to be one of the carcinogenic agents for gastric cancer. Perturbation of epithelial-mesenchymal transition (EMT) results in loss of intracellular adhesions leading to tumor progression. In this study, we examined the underlying mechanism of the long-term effects of nicotine on tumor progression in human gastric cancer cells. Nicotine activated 5-lipoxygenase (5-LOX) in three gastric cancer cell lines (MKN-45, MKN-28 and AGS). Cells treated with nicotine dose- and time-dependently induced cell proliferation, invasion and suppressed apoptosis. In addition, cell cycle progression analysis revealed that activation of 5-LOX modulated the G1/S phase transition regulatory proteins and caused cell proliferation. MK886 (5-LOX activating protein inhibitor) mediated the induction of apoptosis by elevation of caspase-3 and Bax/Bcl2 ratio. Abrogation of 5-LOX repressed featured molecular markers of EMT (inactivation of E-cadherin and activation of transcriptional repressor Snail). Blockade of 5-LOX signaling resulted in downregulation of cyclin D1, matrix metalloproteinase (MMP-7, -9), urokinase plasminogen activator (uPA) and its receptor (uPAR), and pro-apoptotic proteins. Furthermore, suppression of Snail and induction of E-cadherin is extracellular signal-regulated kinase (Erk)-dependent. Thus, we conclude that the promotion effect of nicotine on cancer cell progression and EMT is mediated by Erk/5-LOX signaling pathway.
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PMID:Activation of 5-lipoxygenase is required for nicotine mediated epithelial-mesenchymal transition and tumor cell growth. 2006 Oct 81

The scaffold of 3,5-diaryl-1H-pyrazole was selected as a molecular template to synthesize novel growth-inhibitory agents in the present study. Our findings suggested that analogs bearing electron-withdrawing groups on one ring while electron-donating groups on another reveal significant activities. In particular, 26 bearing a 1,1'-biphenyl moiety displayed the most potent activity against OVCA, SW620, H460 and AGS cells with GI(50) values of 0.67, 0.89, 0.73 and 0.79 microM, respectively. The mechanistic study revealed that 26-mediated apoptosis-inducing effect on OVCA cells was, in part, attributed to the inhibition of protein kinase B/Akt activity, accompanied by the mitochondrial apoptotic pathway through the activation of caspase-9, caspase-3, as well as the cleavage of protein poly(ADP-ribose) polymerase (PARP) and DNA fragmentation. Further structure-activity relationship study employed by Comparative Molecular Field Analysis (CoMFA) was carried out with q(2) and R(2) values of 0.671 and 0.846, respectively.
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PMID:3,5-Diaryl-1H-pyrazole as a molecular scaffold for the synthesis of apoptosis-inducing agents. 2038 60

In our previous study, we showed that Helicobacter pylori gamma-glutamyltranspeptidase (GGT) is associated with H. pylori-induced apoptosis through a mitochondrial pathway. To better understand the role of GGT in apoptosis, we examined the effect of GGT on cell cycle regulation in AGS cells. To determine the effect of recombinant GGT (rGGT) on cell cycle distribution and apoptosis, rGGT-treated and untreated AGS cells were analyzed in parallel by flow cytometry using propidium iodide (PI). We found that rGGT inhibited the growth of AGS cells in a time-dependent manner, and that the pre-exposure of cells to a caspase-3 inhibitor (z-DEVD-fmk) effectively blocked GGT-induced apoptosis. Cell cycle analysis showed G1 phase arrest and apoptosis in AGS cells following rGGT treatment. The rGGT-mediated G1 phase arrest was found to be associated with down-regulation of cyclin E, cyclin A, Cdk 4, and Cdk 6, and the up-regulation of the cyclin-dependent kinase (Cdk) inhibitors p27 and p21. Our results suggest that H. pylori GGT induces cell cycle arrest at the G1-S phase transition.
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PMID:Helicobacter pylori gamma-glutamyltranspeptidase induces cell cycle arrest at the G1-S phase transition. 2057 56


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