Crotoxin induces apoptosis and autophagy in human lung carcinoma cells in vitro via activation of the p38MAPK signaling pathway

Aim:

Crotoxin (CrTX) is the primary toxin in South American rattlesnake (Crotalus durissus terrificus) venom, and exhibits antitumor and other pharmacological actions in vivo and in vitro. Here, we investigated the molecular mechanisms of the antitumor action of CrTX in human lung carcinoma cells in vitro.

Methods:

Human lung squamous carcinoma SK-MES-1 cells were tested. The cytotoxicity of CrTX was evaluated in both MTT and colony formation assays. Cell cycle was investigated with flow cytometry. Cell apoptosis was studied with Hoechst 33258 and Annexin V-FITC staining. The levels of relevant proteins were analyzed using Western blot assays.

Results:

CrTX (25, 50, 100 μmol/L) inhibited the growth and colony formation of SK-MES-1 cells in dose- and time-dependent manners. CrTX increased the proportion of S phase cells and dose-dependently induced cell apoptosis, accompanied by down-regulating the expression of proliferating cell nuclear antigen (PCNA), and increasing the level of cleaved caspase-3. Furthermore, CrTX dose-dependently increased the expression of autophagy-related proteins LC3-II and beclin 1, and decreased the level of p62 in the cells. Moreover, CrTX (50 μmol/L) significantly increased p38MAPK phosphorylation in the cells. Pretreatment of the cells with SB203580, a specific inhibitor of p38MAPK, blocked the inhibition of CrTX on cell proliferation, as well as CrTX-induced apoptosis and cleaved caspase-3 expression.

Conclusion:

The p38MAPK signaling pathway mediates CrTX-induced apoptosis and autophagy of human lung carcinoma SK-MES-1 cells in vitro.     

p38MAPK在戊地昔布诱导Eca109细胞凋亡中的调控作用

目的探讨p38MAPK信号转导途径在戊地昔布诱导食管癌Eca109细胞凋亡中的调控作用。方法将正常培养的人食管癌Eca109细胞随机分为正常对照组、戊地昔布组和戊地昔布+SB203580组;采用流式细胞术和DNA Ladder检测凋亡情况;RT-PCR检测p38mRNA的表达变化;流式细胞术和免疫细胞化学检测p38蛋白的表达变化。结果①戊地昔布能够诱导Eca109细胞发生凋亡,并呈剂量依赖性,而SB203580能够部分降低戊地昔布诱导的Eca109细胞的凋亡率;②戊地昔布能够上调Eca109细胞中p38mRNA和蛋白的表达,而戊地昔布+SB203580组p38mRNA和蛋白的表达下降;③p38蛋白表达与凋亡率呈正相关。结论戊地昔布能够通过部分激活p38MAPK信号途径诱导Eca109细胞发生凋亡。     

Cantharidic acid induces apoptosis through the p38 MAPK signaling pathway in human hepatocellular carcinoma

Cantharidin analogs exhibit anticancer activities, including apoptosis. However, the molecular mechanisms underlying the effects of cantharidic acid (CA), a cantharidin analog, on apoptosis in hepatocellular carcinoma (HCC) cells are unclear. Thus, in this study, we evaluated the anticancer activities of CA by investigating its ability to trigger apoptosis in SK‐Hep‐1 cells. Our data demonstrated that CA effectively inhibited the proliferation of SK‐Hep‐1 cells in a dose‐dependent manner. Furthermore, CA effectively triggered cell cycle arrest and induced apoptosis, as determined by flow cytometric analysis. Western blotting revealed that CA significantly activated proapoptotic signaling including caspase‐3, −8, and −9 in SK‐Hep‐1 cells. Moreover, treatment of SK‐Hep‐1 cells with CA induced the activation of ERK, p38, and c‐Jun N‐terminal kinase. Moreover, the inhibition of p38 by specific inhibitors abolished CA‐induced cell apoptosis. In conclusion, our results indicated that CA induces apoptosis in SK‐Hep‐1 cells through a p38‐mediated apoptotic pathway and could be a new HCC therapeutic agent.     

Involvement of the p38 MAPK signaling pathway in S‐phase cell‐cycle arrest induced by Furazolidone in human hepatoma G2 cells

Given the previously described essential role for the p38 mitogen‐activation protein kinase (p38 MAPK) signaling pathway in human hepatoma G2 cells (HepG2), we undertook the present study to investigate the role of the p38 MAPK signaling pathway in cell‐cycle arrest induced by Furazolidone (FZD). The aim of this study was to determine the effects of FZD on HepG2 cells by activating and inhibiting the p38 MAPK signaling pathway. The cell cycle and proliferation of HepG2 cells treated with FZD were detected by flow cytometry and MTT assay in the presence or absence of p38 MAPK inhibitors (SB203580), respectively. Cyclin D1, cyclin D3 and CDK6 were detected by quantitative real‐time PCR and western blot analysis. Our data showed that p38 MAPK became phosphorylated after stimulation with FZD. Activation of p38 MAPK could arise S‐phase cell‐cycle arrest and suppress cell proliferation. Simultaneously, inhibition of the p38 MAPK signaling pathway significantly prevented S‐phase cell‐cycle arrest, increased the percentage of cell viability and decreased the expression of cyclin D1, cyclin D3 and CDK6. These results demonstrated that FZD arose S‐phase cell‐cycle arrest via activating the p38 MAPK signaling pathway in HepG2 cells. Cyclin D1, cyclin D3 and CDK6 are target genes functioning at the downstream of p38 MAPK in HepG2 cells induced by FZD. Copyright © 2012 John Wiley & Sons, Ltd.     

ERK and p38 MAPK signaling pathways are involved in ochratoxin A-induced G2 phase arrest in human gastric epithelium cells

Ochratoxin A (OTA) is a ubiquitous mycotoxin with potential nephrotoxic, hepatotoxic, and immunotoxic effects. Recent work from our laboratory found that OTA evoked G2 phase arrest in GES-1 cells in vitro by modulating the key factors Cdc25C, Cdc2 and cyclinB1, which were critical to the G2/M phase transmission, suggested that OTA-induced G2 arrest mediate at least in part OTA toxicity effect. However, the molecular mechanism of this effect is currently unclear. In the present study, we showed that treatment of GES-1 cells with OTA could induce the activation of MAPK family members ERK and p38. ERK inhibitor PD98059 and p38 inhibitor SB203580 significantly reversed the depression of Cdc25C/p-Cdc25C, Cdc2/p-Cdc2, cyclinB1 as well as the cyclinB1-Cdc2 complex, thereby, abolished the delay in G2 phase. In addition, silencing ERK and p38 expression with siRNA significantly inhibited OTA-induced G2 arrest in GES-1 cells as well. Collectively, these data suggest that the ERK and p38 MAPK signaling pathways play important roles in the regulation of OTA-induced G2 arrest in GES-1 cells.     

Tetrahydrocurcumin induces G2/M cell cycle arrest and apoptosis involving p38 MAPK activation in human breast cancer cells

Curcumin (CUR) is a major naturally-occurring polyphenol of Curcuma species, which is commonly used as a yellow coloring and flavoring agent in foods. In recent years, it has been reported that CUR exhibits significant anti-tumor activity in vivo. However, the pharmacokinetic features of CUR have indicated poor oral bioavailability, which may be related to its extensive metabolism. The CUR metabolites might be responsible for the antitumor pharmacological effects in vivo. Tetrahydrocurcumin (THC) is one of the major metabolites of CUR. In the present study, we examined the efficacy and associated mechanism of action of THC in human breast cancer MCF-7 cells for the first time. Here, THC exhibited significant cell growth inhibition by inducing MCF-7 cells to undergo mitochondrial apoptosis and G2/M arrest. Moreover, co-treatment of MCF-7 cells with THC and p38 MAPK inhibitor, SB203580, effectively reversed the dissipation in mitochondrial membrane potential (Δψm), and blocked THC-mediated Bax up-regulation, Bcl-2 down-regulation, caspase-3 activation as well as p21 up-regulation, suggesting p38 MAPK might mediate THC-induced apoptosis and G2/M arrest. Taken together, these results indicate THC might be an active antitumor form of CUR in vivo, and it might be selected as a potentially effective agent for treatment of human breast cancer.     

p38MAPK抑制剂SB-202190对大鼠胶质瘤C6细胞的双重作用

目的　探讨 p38MAPK抑制剂SB 2 0 2 190对C6细胞生物活性的影响。方法　采用透射电镜的方法和DNA琼脂糖凝胶电泳的方法观察SB 2 0 2 190诱导胶质瘤细胞的凋亡 ;应用流式细胞仪检测细胞周期变化和是否有凋亡发生。结果　浓度分别为 10、2 0、4 0 μmol·L-1的SB 2 0 2 190能促进C6细胞的细胞周期从G1期过度到S期 ;但 6 0 μmol·L-1的SB 2 0 2 190却诱导C6细胞凋亡 ,凋亡率与时间呈正相关 ,透射电镜观察结果显示 ,凋亡细胞的体积缩小、细胞核浓聚缩小 ,染色质固缩聚集于核膜下 ,胞质浓缩 ,有的细胞染色质浓缩至核膜下成新月状 ;琼脂糖凝胶电泳呈现出特征性的DNA“梯状”带。结论　SB 2 0 2 190在低浓度时促进C6细胞增殖 ,高浓度时诱导细胞凋亡。     

Involvement of the activation of Nrf2/HO-1, p38 MAPK signaling pathways and endoplasmic reticulum stress in furazolidone induced cytotoxicity and S phase arrest in human hepatocyte L02 cells: modulation of curcumin

Furazolidone (FZD) is extensively used as the antiprotozoal and antibacterial drug in clinic. The previous study has shown that curcumin pretreatment could improve FZD induced cytotoxicity by inhibiting oxidative stress and mitochondrial apoptotic pathway. The current study aimed to investigate the potential roles of endoplasmic reticulum (ER) stress, p38 mitogen-activated protein kinases (p38 MAPK) signaling pathway in curcumin against FZD cytotoxicity by using human hepatocyte L02 cells. The results showed that curcumin could markedly attenuate FZD induced cytotoxicity. Compared with FZD alone group, curcumin pretreatment significantly reduced the expression of phospho (p)-p38, cyclin D1, p-checkpoint kinase 1 (ChK1) and breast cancer associated gene 1 (BRCA1) protein, followed to attenuate S phase arrest. Meanwhile, curcumin pretreatment prevented FZD induced ER stress, evidenced by the inhibition of glucose-regulated protein 78 and DNA damage inducible gene 153/C/EBP-homologous protein (GADD153/CHOP) protein expression. Moreover, compared with the control, FZD exposure activated the protein and mRNA expression levels of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase 1 (HO-1), which were further activated by curcumin treatment. These results reveal that curcumin could prevent FZD induced cytotoxicity and S phase arrest, which may involve the activation of Nrf2/HO-1 pathway and the inhibition of p38 MAPK pathway and ER stress.     

Novel ferrocenyl derivatives exert anti-cancer effect in human lung cancer cells in vitro via inducing G1-phase arrest and senescence

Aim:

To investigate the effects of 7 novel 1-ferrocenyl-2-(5-phenyl-1H-1,2,4-triazol-3-ylthio) ethanone derivatives on human lung cancer cells in vitro and to determine the mechanisms of action.

Methods:

A549 human lung cancer cells were examined. Cell viability was analyzed with MTT assay. Cell apoptosis and senescence were examined using Hoechst 33258 and senescence-associated-β-galactosidase (SA-β-gal) staining, respectively. LDH release was measured using a detection kit. Cell cycle was analyzed using a flow cytometer. Intracellular ROS level was measured with the 2′,7′-dichlorodihydrofluorescein probe. Phosphorylation of p38 was determined using Western blot.

Results:

Compounds 5b, 5d, and 5e (40 and 80 μmol/L) caused significant decrease of A549 cell viability, while other 4 compounds had no effect on the cells. Compounds 5b, 5d, and 5e (80 μmol/L) induced G₁-phase arrest (increased the G₁ population by 22.6%, 24.23%, and 26.53%, respectively), and markedly increased SA-β-gal-positive cells. However, the compounds did not cause nuclear DNA fragmentation and chromatin condensation in A549 cells. Nor did they affect the release of LDH from the cells. The compounds significantly elevated the intracellular ROS level, decreased the mitochondrial membrane potential, and increased p38 phosphorylation in the cells. In the presence of the antioxidant and free radical scavenger N-acetyl-L-cysteine (10 mmol/L), above effects of compounds 5b, 5d, and 5e were abolished.

Conclusion:

The compounds 5b, 5d, and 5e cause neither apoptosis nor necrosis of A549 cells, but exert anti-cancer effect via inducing G₁-phase arrest and senescence through ROS/p38 MAP-kinase pathway.     

Berberine induces apoptosis in SW620 human colonic carcinoma cells through generation of reactive oxygen species and activation of JNK/p38 MAPK and FasL

Berberine is the major constituent of Coptidis Rhizoma with multiple pharmacological activities, including anti-inflammation, promotion of apoptosis and anticancer potential effect. Mitogen-activated protein kinase (MAPK) and reactive oxygen species (ROS) may contribute to the causal relationship between tumorigenesis and pro-apoptotic function. Berberine is studied for the mechanism of its action in apoptotic pathway in human colonic carcinoma cell. Treatment of SW620 cells with 50 μM berberine resulted in activation of the caspase 3 and caspase 8, cleavage of poly ADP-ribose polymerase (PARP) and the release of cytochrome c; whereas, the expression of BID and anti-apoptosis factor c-IAP1, Bcl-2, and Bcl-_XL were decreased markedly. Berberine-induced, dose-dependent induction of apoptosis was accompanied by sustained phosphorylation of JNK and p38 MAPK, as well as generation of the ROS. Furthermore, the induction of apoptosis was alleviated by inhibitors specific for JNK and p38. In addition, there was an increase in the cellular levels of phospho-c-Jun, FasL and t-BID in the berberine-induced apoptosis via the activation of JNK and p38 signaling modules. NAC administration, a scavenger of ROS, reversed berberine-induced apoptosis effects via inhibition of JNK, p38 and c-jun activation, and FasL and t-BID expression. These results leads us to speculate that berberine may play an apoptotic cascade in SW620 cells by activation of the JNK/p38 pathway and induction of ROS production, providing a new mechanism for berberine-induced cell death in human colon cancer cells.     

TLR4-p38MAPK信号通路在金黄色葡萄球菌感染人巨噬细胞系U937过程中的表达及意义

目的观察金黄色葡萄球菌感染人巨噬细胞系U937细胞后信号通路Toll样受体4(TLR4)-p38蛋白激酶(p38MAPK)的表达及意义。方法体外培养人巨噬细胞系U937细胞,感染0、30、60和90 min时收集细胞,应用Western blot法检测各组TLR4和p38MAPK蛋白表达的变化;在另一实验中,分为对照组、金黄色葡萄球菌感染60 min组及p38MAPK抑制剂SB203580 5 mg/m L干预组、SB203580 10 mg/m L干预组,应用Western blot法检测各组TLR4和p38MAPK蛋白表达的变化。结果随着感染时间的延长,TLR4和p38MAPK蛋白的表达逐渐增加;给予SB203580抑制剂后,TLR4和p38MAPK蛋白的表达明显减弱。结论金黄色葡萄球菌感染U937细胞可引起TLR4-p38MAPK信号通路的活化,而SB203580对其有明显的抑制作用,证明TLR4-p38MAPK信号通路与金黄色葡萄球菌感染U937细胞密切相关。     

莱菔硫烷诱导人肝癌 HepG-2 细胞凋亡的 p38MAPK 途径研究

目的：探讨莱菔硫烷（sulforaphane, SFN）诱导人肝癌 HepG-2 细胞凋亡过程中,p38MAPK 途径的作用。方法：流式细胞仪检测 SFN 对 HepG-2 细胞凋亡率的影响,Western Blotting 方法检测细胞内 p38 及 p-p38 蛋白表达。结果：SFN可明显诱导 HepG-2 细胞凋亡,10、20、40 μmol/L SFN 作用 48 h 后,对 HepG-2 细胞的抑制率分别达到 27.42 %、46.53 %、58.92 %;10、20、40 μmol/L 的 SFN 可上调 HepG-2 细胞内 p-p38 蛋白的表达,而对 p38 的表达无明显影响。结论：SFN 可诱导 HepG-2细胞的凋亡,而且这一过程与阻断 p38MAPK 途径有关。     

p38 MAPK激酶抑制剂增强二烯丙基二硫化物诱导CNE2细胞凋亡

目的　研究二烯丙基二硫化物 (DADS)诱导CNE2细胞凋亡及 p38MAPK信号转导通路对此过程的作用。 方法　DADS处理CNE2细胞 2 4h后 ,荧光显微镜下观察形态学变化及凋亡细胞计数 ,MTT法测定细胞活性 ,流式细胞仪检测凋亡细胞 ,蛋白质印迹法检测磷酸化p38MAPK表达。结果　在培养的CNE2细胞中 ,DADS(50～ 1 50 μmol·L- 1 )作用 2 4h后 ,DADS诱导CNE2细胞产生典型的凋亡细胞形态学变化 (核浓染 ,核碎裂 ) ,流式细胞仪结果显示 ,随着DADS给药剂量增加 ,细胞周期中各期细胞所占百分率的变化无规律 ,细胞凋亡呈剂量依赖性 ,DADS(50～ 1 50 μmol·L- 1 )浓度依赖性刺激磷酸化p38MAPK的表达 ,p38MAPK抑制剂SB2 0 3580明显增强DADS致凋亡作用。结论　DADS诱导CNE2细胞凋亡时激活磷酸化 p38MAPK表达 ,磷酸化p38MAPK抑制剂增强DADS诱导CNE2细胞凋亡效应     

硼酸钠活化p53诱导人肝癌细胞HepG2凋亡

目的观察硼酸钠(Borax)对人肝癌细胞株Hep G2的生长抑制和诱导凋亡的作用,并初步探讨其作用机制。方法采用MTT法检测不同浓度硼酸钠对Hep G2活力的影响,DAPI染色荧光显微镜及Annexin V-FITC/PI双染色流式细胞术检测硼酸钠诱导细胞凋亡的情况。实时荧光定量PCR(qRT-PCR)检测硼酸钠对肿瘤抑制因子p53及其下游基因Bcl-2、Bax、Noxa、Puma mRNA表达的影响。结果与对照组比较,硼酸钠各剂量组均能抑制Hep G2的活力(P<0.01);硼酸钠诱导Hep G2细胞凋亡,不同浓度硼酸钠(0、1.0、2.0、4.0 mmol/L)处理24 h后,晚期凋亡细胞百分比从2.57%分别增加至8.13%、10.4%、15.24%,差异有统计学意义(P<0.01);硼酸钠(4.0 mmol/L)分别作用6、12、24 h后,均可不同程度上调肿瘤抑制因子p53及促凋亡基因Bax、Noxa、Puma mRNA表达,抑制抗凋亡基因Bcl-2 mRNA的表达,差异有统计学意义(P<0.01)。结论硼酸钠抑制人肝癌细胞Hep G2的生长活性并诱导凋亡,其机制与p53的活化及其下游Bax、Noxa、Puma基因表达上调,以及Bcl-2表达下调有关。     

Osthole induces G2/M cell cycle arrest and apoptosis in human hepatocellular carcinoma HepG2 cells

Context: Osthole [7-methoxy-8-(3-methyl-2-butenyl) coumarin] isolated from the fruit of Cnidium monnieri (L.) Cuss, one of the commonly used Chinese medicines listed in the Shennong’s Classic of Materia Medica in the Han Dynasty, had remarkable antiproliferative activity against human hepatocellular carcinoma HepG2 cells in culture.

Objectives: This study evaluated the effects of osthole on cell growth, nuclear morphology, cell cycle distribution, and expression of apoptosis-related proteins in HepG2 cells.

Materials and methods: Cytotoxic activity of osthole was determined by the MTT assay at various concentrations ranging from 0.004 to 1.0?µmol/ml in HepG2 cells. Cell morphology was assessed by Hoechst staining and fluorescence microscopy. Apoptosis and cell-cycle distribution was determined by annexin V staining and flow cytometry. Apoptotic protein levels were assessed by Western blot.

Results: Osthole exhibited significant inhibition of the survival of HepG2 cells and the half inhibitory concentration (IC₅₀) values were 0.186, 0.158 and 0.123?µmol/ml at 24, 48 and 72?h, respectively. Cells treated with osthole at concentrations of 0, 0.004, 0.02, 0.1 and 0.5?μmol/ml showed a statistically significant increase in the G2/M fraction accompanied by a decrease in the G0/G1 fraction. The increase of apoptosis induced by osthole was correlated with down-regulation expression of anti-apoptotic Bcl-2 protein and up-regulation expression of pro-apoptotic Bax and p53 proteins.

Conclusion: Osthole had significant growth inhibitory activity and the pro-apoptotic effect of osthole is mediated through the activation of caspases and mitochondria in HepG2 cells. Results suggest that osthole has promising therapeutic potential against hepatocellular carcinoma.     

Taiwanin E inhibits cell migration in human LoVo colon cancer cells by suppressing MMP‐2/9 expression via p38 MAPK pathway

Taiwanin E is a natural compound which is structurally analogous to estrogen II and is abundantly found in Taiwania cryptomerioides. It has been previously reported for its anticancer effects; however, the pharmaceutical effect of Taiwanin E on Human LoVo colon cancer cells is not clear. In this study, we investigated the effects of Taiwanin E on metastasis and the associated mechanism of action on Human LoVo colon cancer cells with respect to the modulations in their cell migration and signaling pathways associated with migration. The results showed that Taiwanin E inhibited cell migration ability correlated with reduced expression and activity of MMP‐2 and MMP‐9. In addition, Taiwanin E induced activation of p38 through phosphorylation. Inhibition of p38α/β significantly abolished the effect of Taiwanin E on cell migration and MMP‐2/‐9 activity. Our results conclude that Taiwanin E inhibited cell migration chiefly via p38α MAPK pathway and in a lesser extend via p38β MAPK. The results elucidate the potential of the phytoestrogen natural compound Taiwanin E as a cancer therapeutic agent in inhibiting the cell migration. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 2021–2031, 2017.     

PTPL1 suppresses lung cancer cell migration via inhibiting TGF-β1-induced activation of p38 MAPK and Smad 2/3 pathways and EMT

Epithelial-mesenchymal transition (EMT) enables dissemination of neoplastic cells and onset of distal metastasis of primary tumors. However, the regulatory mechanisms of EMT by microenvironmental factors such as transforming growth factor-β (TGF-β) remain largely unresolved. Protein tyrosine phosphatase L1 (PTPL1) is a non-receptor protein tyrosine phosphatase that plays a suppressive role in tumorigenesis of diverse tissues. In this study we investigated the role of PTPL1/PTPN13 in metastasis of lung cancer and the signaling pathways regulated by PTPL1 in terms of EMT of non-small cell lung cancer (NSCLC) cells. We showed that the expression of PTPL1 was significantly downregulated in cancerous tissues of 23 patients with NSCLC compared with adjacent normal tissues. PTPL1 expression was positively correlated with overall survival of NSCLC patients. Then we treated A549 cells in vitro with TGF-β1 (10 ng/mL) and assessed EMT. We found that knockdown of PTPL1 enhanced the migration and invasion capabilities of A549 cells, through enhancing TGF-β1-induced EMT. In nude mice bearing A549 cell xenografts, knockdown of PTPL1 significantly promoted homing of cells and formation of tumor loci in the lungs. We further revealed that PTPL1 suppressed TGF-β-induced EMT by counteracting the activation of canonical Smad2/3 and non-canonical p38 MAPK signaling pathways. Using immunoprecipitation assay we demonstrated that PTPL1 could bind to p38 MAPK, suggesting that p38 MAPK might be a direct substrate of PTPL1. In conclusion, these results unravel novel mechanisms underlying the regulation of TGF-β signaling pathway, and have implications for prognostic assessment and targeted therapy of metastatic lung cancer.     

Abrus agglutinin suppresses human hepatocellular carcinoma in vitro and in vivo by inducing caspase- mediated cell death

Aim： Abrus agglutinin （AGG） from the seeds of Indian medicinal plant Abrus precatorius belongs to the class II ribosome inactivating protein family. In this study we investigated the anticancer effects of AGG against human hepatocellular carcinoma in vitro and in vivo.
Methods： Cell proliferation, DNA fragmentation, Annexin V binding, immunocytofluorescence, Western blotting, caspase activity assays and luciferase assays were performed to evaluate AGG in human liver cancer cells HepG2. Immunohistochemical staining and TUNEL expression were studied in tumor samples of HepG2-xenografted nude mice.
Results： AGG induced apoptosis in HepG2 cells in a dose- and time-dependent manner. AGG-treated HepG2 cells demonstrated an increase in caspase 3/7, 8 and 9 activities and a sharp decrease in the Bcl-2/Bax ratio, indicating activation of a caspase cascade. Co-treatment of HepG2 cells with AGG and a caspase inhibitor or treatment of AGG in Bax knockout HepG2 cells decreased the caspase 3/7 activity in comparison to HepG2 cells exposed only to AGG. Moreover, AGG decreased the expression of Hsp90 and suppressed Akt phosphorylation and NF-κB expression in HepG2 cells. Finally, AGG treatment significantly reduced tumor growth in nude mice bearing HepG2 xenografts, increased TUNEL expression and decreased CD-31 and Ki-67 expression compared to levels observed in the untreated control mice bearing HepG2 cells.
Conclusion： AGG inhibits the growth and progression of HepG2 cells by inducing caspase-mediated cell death. The agglutinin could be an alternative natural remedy for the treatment of human hepatocellular carcinomas.     

Sulfur mustard primes human neutrophils for increased degranulation and stimulates cytokine release via TRPM2/p38 MAPK signaling

Sulfur mustard (2,2′-bis-chloroethyl-sulfide; SM) has been a military threat since the World War I. The emerging threat of bioterrorism makes SM a major threat not only to military but also to civilian world. SM injury elicits an inflammatory response characterized by infiltration of neutrophils. Although SM was reported to prime neutrophils, the mechanism has not been identified yet. In the present study, we investigated the mechanism of SM-induced priming in human neutrophils. SM increased [Ca^2 +]_i in human neutrophils in a concentration-dependent fashion. Transient receptor potential melastatin (TRPM) 2 inhibitors (clotrimazole, econazole and flufenamic acid) and silencing of TRPM2 by shRNA attenuated SM-induced [Ca^2 +]_i increase. SM primed degranulation of azurophil and specific granules in response to activation by fMLP as previously reported. SB203580, an inhibitor of p38 MAPK, inhibited SM-induced priming. Neither PD98057, an ERK inhibitor, nor SP600215, a JNK inhibitor, inhibited SM-induced priming. In addition, SM enhanced phosphorylation of NF-kB p65 and release of TNF-α, interleukin (IL)-6 and IL-8. SB203580 inhibited SM-induced NF-kB phosphorylation and cytokine release. These results suggest the involvement of TRPM2/p38 MAPK pathway in SM-induced priming and cytokines release in neutrophils.