ABSTRACT
Fucoidan is one of the main bioactive components of polysaccharides. The current study was focused on the anti-tumor effects of fucoidan on human heptoma cell line HepG2 and the possible mechanisms. Fucoidan treatment resulted in cell cycle arrest and apoptosis of HepG2 cells in a dose-dependent manner detected by MTT assay, flow cytometry and fluorescent microscopy. The results of flow cytometric analysis revealed that fucoidan induced G2/M arrest in the cell cycle progression. Hoechst 33258 and Annexin V/PI staining results showed that the apoptotic cell number was increased, which was associated with a dose-dependent up-regulation of Bax and down-regulation of Bcl-2 and p-Stat3. In parallel, the up-regulation of p53 and the increase in reactive oxygen species were also observed, which may play important roles in the inhibition of HepG2 growth by fucoidan. In the meantime, Cyclin B1 and CDK1 were down-regulated by fucoidan treatment. Down-regulation of p-Stat3 by fucoidan resulted in apoptosis and an increase in ROS in response to fucoidan exposure. We therefore concluded that fucoidan induces apoptosis through the down-regulation of p-Stat3. These results suggest that fucoidan may be used as a novel anti-cancer agent for hepatocarcinoma.
Subject(s)
Humans , Antineoplastic Agents , Pharmacology , Apoptosis , Blotting, Western , CDC2 Protein Kinase , Genetics , Metabolism , Cyclin B1 , Genetics , Metabolism , Dose-Response Relationship, Drug , Down-Regulation , Flow Cytometry , G2 Phase Cell Cycle Checkpoints , Genetics , Gene Expression Regulation, Neoplastic , Hep G2 Cells , Hepatoblastoma , Genetics , Metabolism , Pathology , Liver Neoplasms , Genetics , Metabolism , Pathology , Microscopy, Fluorescence , Polysaccharides , Pharmacology , Proto-Oncogene Proteins c-bcl-2 , Genetics , Metabolism , Reactive Oxygen Species , Metabolism , Reverse Transcriptase Polymerase Chain Reaction , STAT3 Transcription Factor , Genetics , Metabolism , Tumor Suppressor Protein p53 , Genetics , Metabolism , bcl-2-Associated X Protein , Genetics , MetabolismABSTRACT
Icaritin, a prenylflavonoid derivative from Epimedium Genus, has been shown to exhibit many pharmacological and biological activities. However, the function and the underlying mechanisms of icaritin in human non-small cell lung cancer have not been fully elucidated. The purpose of this study was to investigate the anticancer effects of icaritin on A549 cells and explore the underlying molecular mechanism. The cell viability after icaritin treatment was tested by MTT assay. The cell cycle distribution, apoptosis and reactive oxygen species (ROS) levels were analyzed by flow cytometry. The mRNA and protein expression levels of the genes involved in proliferation and apoptosis were respectively detected by RT-PCR and Western blotting. The results demonstrated that icaritin induced cell cycle arrest at S phase, and down-regulated the expression levels of S regulatory proteins such as Cyclin A and CDK2. Icaritin also induced cell apoptosis characterized by positive Hoechst 33258 staining, accumulation of the Annexin V-positive cells, increased ROS level and alteration in Bcl-2 family proteins expression. Moreover, icaritin induced sustained phosphorylation of ERK and p38 MAPK. These findings suggested that icaritin might be a new potent inhibitor by inducing S phase arrest and apoptosis in human lung carcinoma A549 cells.
Subject(s)
Humans , Antineoplastic Agents, Phytogenic , Pharmacology , Apoptosis , Cell Line, Tumor , Flavonoids , Pharmacology , Lung Neoplasms , Drug Therapy , Metabolism , Pathology , MAP Kinase Signaling System , Neoplasm Proteins , Reactive Oxygen Species , Metabolism , S Phase Cell Cycle CheckpointsABSTRACT
Icaritin, a prenylflavonoid derivative from Epimedium Genus, has been shown to exhibit many pharmacological and biological activities. However, the function and the underlying mechanisms of icaritin in human non-small cell lung cancer have not been fully elucidated. The purpose of this study was to investigate the anticancer effects of icaritin on A549 cells and explore the underlying molecular mechanism. The cell viability after icaritin treatment was tested by MTT assay. The cell cycle distribution, apoptosis and reactive oxygen species (ROS) levels were analyzed by flow cytometry. The mRNA and protein expression levels of the genes involved in proliferation and apoptosis were respectively detected by RT-PCR and Western blotting. The results demonstrated that icaritin induced cell cycle arrest at S phase, and down-regulated the expression levels of S regulatory proteins such as Cyclin A and CDK2. Icaritin also induced cell apoptosis characterized by positive Hoechst 33258 staining, accumulation of the Annexin V-positive cells, increased ROS level and alteration in Bcl-2 family proteins expression. Moreover, icaritin induced sustained phosphorylation of ERK and p38 MAPK. These findings suggested that icaritin might be a new potent inhibitor by inducing S phase arrest and apoptosis in human lung carcinoma A549 cells.
ABSTRACT
Fucoidan is one of the main bioactive components of polysaccharides. The current study was focused on the anti-tumor effects of fucoidan on human heptoma cell line HepG2 and the possible mechanisms. Fucoidan treatment resulted in cell cycle arrest and apoptosis of HepG2 cells in a dose-dependent manner detected by MTT assay, flow cytometry and fluorescent microscopy. The results of flow cytometric analysis revealed that fucoidan induced G2/M arrest in the cell cycle progression. Hoechst 33258 and Annexin V/PI staining results showed that the apoptotic cell number was increased, which was associated with a dose-dependent up-regulation of Bax and down-regulation of Bcl-2 and p-Stat3. In parallel, the up-regulation of p53 and the increase in reactive oxygen species were also observed, which may play important roles in the inhibition of HepG2 growth by fucoidan. In the meantime, Cyclin B1 and CDK1 were down-regulated by fucoidan treatment. Down-regulation of p-Stat3 by fucoidan resulted in apoptosis and an increase in ROS in response to fucoidan exposure. We therefore concluded that fucoidan induces apoptosis through the down-regulation of p-Stat3. These results suggest that fucoidan may be used as a novel anti-cancer agent for hepatocarcinoma.
ABSTRACT
Previous studies have shown that STAT3 plays a vital role in the genesis and progression of cancer. In this study, we investigated the relationship between the JAK2/STAT3 signalling pathway and germacrone-induced apoptosis in HepG2 cells. HepG2 cells were incubated with germacrone for 24 h, the protein expression of p-STAT3, STAT3, p-JAK2 and JAK2 was detected by Western Blotting, and RT-PCR was used to determine the expression of STAT3, p53, Bcl-2 and Bax at transcriptional levels. Besides that, HepG2 cells were pre-treated with AG490 or IL-6 for 2 h, and then incubated with germacrone for 24 h. The expression of p-JAK2, JAK2, p-STAT3, STAT3, p53, Bax and Bcl-2 was detected by Western blotting. The activity of HepG2 cells was tested by MTT assay. The apoptosis of HepG2 cells and levels of reactive oxygen species (ROS) were flow cytometrically measured. The results showed that germacrone exposure decreased p-STAT3 and p-JAK2 and regulated expression of p53 and Bcl-2 family members at the same time. Moreover, IL-6 enhanced the activation of the JAK2/STAT3 signalling pathway and therefore attenuated the germacrone-induced apoptosis. Suppression of JAK2/STAT3 signalling pathway by AG490, an inhibitor of JAK2, resulted in apoptosis and an increase in ROS in response to germacrone exposure. We therefore conclude that germacrone induces apoptosis through the JAK2/STAT3 signalling pathway.
ABSTRACT
Fucoidan is an active component of seaweed, which inhibits proliferation and induces apoptosis of several tumor cells while the detailed mechanisms underlying this process are still not clear. In this study, the effect of Fucoidan on the proliferation and apoptosis of human breast cancer MCF-7 cells and the molecular mechanism of Fucoidan action were investigated. Viable cell number of MCF-7 cells was decreased by Fucoidan treatment in a dose-dependent manner as measured by MTT assay. Fucoidan treatment resulted in G1 phase arrest of MCF-7 cells as revealed by flow cytometry, which was associated with the decrease in the gene expression of cyclin D1 and CDK-4. Annexin V/PI staining results showed that the number of apoptotic cells was associated with regulation of cytochrome C, caspase-8, Bax and Bcl-2 at transcriptional and translational levels. Both morphologic observation and Hoechst 33258 assay results confirmed the pro-apoptotic effect of Fucoidan. Meanwhile, the ROS production was also increased by Fucoidan treatment, which suggested that Fucoidan induced oxidative damage in MCF-7 cells. The results of present study demonstrated that Fucoidan could induce G1 phase arrest and apoptosis in MCF-7 cells through regulating the cell cycle and apoptosis-related genes or proteins expression, and ROS generation is also involved in these processes.
ABSTRACT
Previous studies have shown that STAT3 plays a vital role in the genesis and progression of cancer. In this study, we investigated the relationship between the JAK2/STAT3 signalling pathway and germacrone-induced apoptosis in HepG2 cells. HepG2 cells were incubated with germacrone for 24 h, the protein expression of p-STAT3, STAT3, p-JAK2 and JAK2 was detected by Western Blotting, and RT-PCR was used to determine the expression of STAT3, p53, Bcl-2 and Bax at transcriptional levels. Besides that, HepG2 cells were pre-treated with AG490 or IL-6 for 2 h, and then incubated with germacrone for 24 h. The expression of p-JAK2, JAK2, p-STAT3, STAT3, p53, Bax and Bcl-2 was detected by Western blotting. The activity of HepG2 cells was tested by MTT assay. The apoptosis of HepG2 cells and levels of reactive oxygen species (ROS) were flow cytometrically measured. The results showed that germacrone exposure decreased p-STAT3 and p-JAK2 and regulated expression of p53 and Bcl-2 family members at the same time. Moreover, IL-6 enhanced the activation of the JAK2/STAT3 signalling pathway and therefore attenuated the germacrone-induced apoptosis. Suppression of JAK2/STAT3 signalling pathway by AG490, an inhibitor of JAK2, resulted in apoptosis and an increase in ROS in response to germacrone exposure. We therefore conclude that germacrone induces apoptosis through the JAK2/STAT3 signalling pathway.
Subject(s)
Humans , Apoptosis , Dose-Response Relationship, Drug , Drugs, Chinese Herbal , Hep G2 Cells , Janus Kinase 2 , Metabolism , STAT3 Transcription Factor , Metabolism , Sesquiterpenes, Germacrane , Signal TransductionABSTRACT
Fucoidan is an active component of seaweed, which inhibits proliferation and induces apoptosis of several tumor cells while the detailed mechanisms underlying this process are still not clear. In this study, the effect of Fucoidan on the proliferation and apoptosis of human breast cancer MCF-7 cells and the molecular mechanism of Fucoidan action were investigated. Viable cell number of MCF-7 cells was decreased by Fucoidan treatment in a dose-dependent manner as measured by MTT assay. Fucoidan treatment resulted in G1 phase arrest of MCF-7 cells as revealed by flow cytometry, which was associated with the decrease in the gene expression of cyclin D1 and CDK-4. Annexin V/PI staining results showed that the number of apoptotic cells was associated with regulation of cytochrome C, caspase-8, Bax and Bcl-2 at transcriptional and translational levels. Both morphologic observation and Hoechst 33258 assay results confirmed the pro-apoptotic effect of Fucoidan. Meanwhile, the ROS production was also increased by Fucoidan treatment, which suggested that Fucoidan induced oxidative damage in MCF-7 cells. The results of present study demonstrated that Fucoidan could induce G1 phase arrest and apoptosis in MCF-7 cells through regulating the cell cycle and apoptosis-related genes or proteins expression, and ROS generation is also involved in these processes.
Subject(s)
Humans , Antineoplastic Agents , Chemistry , Pharmacology , Apoptosis , Genetics , Blotting, Western , Breast Neoplasms , Genetics , Metabolism , Pathology , Caspase 8 , Genetics , Metabolism , Caspases , Genetics , Metabolism , Cell Proliferation , Cell Size , Cyclin D1 , Genetics , Metabolism , Cyclin-Dependent Kinase 4 , Genetics , Metabolism , Cytochromes c , Genetics , Metabolism , Dose-Response Relationship, Drug , Fucus , Chemistry , G1 Phase Cell Cycle Checkpoints , Genetics , Gene Expression Regulation, Neoplastic , MCF-7 Cells , Microscopy, Fluorescence , Molecular Structure , Polysaccharides , Chemistry , Pharmacology , Proto-Oncogene Proteins c-bcl-2 , Genetics , Metabolism , Reactive Oxygen Species , Metabolism , Reverse Transcriptase Polymerase Chain Reaction , Signal Transduction , bcl-2-Associated X Protein , Genetics , MetabolismABSTRACT
<p><b>OBJECTIVE</b>To observe the effects of electroacupuncture (EA) on the apoptosis of brain tissue cells and the expression of Caspase-3 in the rats with cerebral-cardiac syndrome (CCS).</p><p><b>METHODS</b>A total of 70 healthy SD rats were selected. Ten was randomly recruited as the sham-operation group, and the rest were used for CCS model preparation. Thirty successfully modeled rats were divided into the model group, the EA group, and the non-EA group, 10 in each group. The model was prepared using injecting collagenase + heparin into the caudate nucleus. Equal volume of 0.9% sodium chloride injection was injected to rats' caudate nucleus in the sham-operation group. EA was started on the 1st day of modeling. Shuigou (GV26), Fengfu (GV16), Neiguan (PC6), and Xinshu (BL15) were needled in the EA group. Four points in the hips were needled in the non-EA group. The EA needling lasted for 20 min each time, once daily, for 3 successive times. No EA was administered to the sham-operation group or the model group. The apoptosis of brain tissue around the hematoma and the expression of Caspase-3 were detected using TUNEL and immunochemical assay.</p><p><b>RESULTS</b>TUNEL cells could be occasionally seen with fewer Caspase-3 expression in the sham-operation group. More TUNEL positive cells appeared in the tissue around the hematoma of the model group with a large amount of Caspase-3 expression. The TUNEL positive cells and Caspase-3 expression were obviously less in the EA group than in the model group and the non-EA group (P < 0.01).</p><p><b>CONCLUSIONS</b>EA could inhibit the apoptosis of brain tissue cells in CCS rats. Its mechanisms might be associated with down-regulating the Caspase-3 expression of the brain tissue around the hematoma.</p>
Subject(s)
Animals , Rats , Apoptosis , Brain , Metabolism , Caspase 3 , Metabolism , Cerebral Hemorrhage , Metabolism , Pathology , Electroacupuncture , Heart Diseases , Metabolism , Pathology , Rats, Sprague-DawleyABSTRACT
To achieve higher level expression of Interferon α2b (IFN-α2b) in methylotrophic yeast (Pichia pastoris), a cDNA fragment coding for the mature IFN-α2b was designed and synthesized based on the synonymous codon bias of P. pastoris and optimized G+C content. The synthetic IFN-α2b was inserted into the secreted expression vector pPICZαA, and then integrated into P. pastoris GS115 genome by electroporation. Multi-copy integrants in the Mut+ recombinant P. pastoris strain were screened by high concentrations of Zeocin. 120 hours culturing allowed expression of the IFN-α2b transformant up to 810 mg/L as detected by SDS-PAGE and quantitative methods. In addition, Western blot analysis showed that the recombinant proteins had immunogenicity. The significant antiviral activity of the recombinant IFN-α2b protein was verified by WISH/ VSV system, which was 3.3×105 IU/mL.
ABSTRACT
The high molecular weight glutenin subunits (HMW-GS) are the main components of storage proteins of wheat,and play a critical role in determining the visco-elastic properties of gluten. There are both quantitative and qualitative effects of HMW-GS on the processing properties of wheat. Current knowledge of the molecular structures,compositions and properties of the gluten proteins of wheat is summarized in details,and the role of the HMW-GS in determining the quality of the grain for breadmaking and how their amount and composition can be manipulated leading to changes in dough mixing properties is also discussed systematically.
ABSTRACT
The method of multiplex PCR was set up to identify two or three transgenes in one reaction such as uidA and bar; uidA and IDx5 or uidA, bar and 1Dx5 genes. Three sets of primer pairs which was specific to each of these three genes respectively were designed and synthesized. Recombinant plasmids pAHC25 and p1Dx5 harboring uidA + bar and 1Dx5 gene separately were used as template DNA in the process of optimizing an multiplex PCR reaction. The optimal annealing temperature for uidA and bar MPCR is range from 57. 1℃-62. 3℃ , for uidA and 1Dx5 is range from 60℃ to 60. 6℃ , and for uidA、bar and 1Dx5 range from 57. 0℃-58. 4℃. The amount of template for MPCR is twice as much as that for simplex PCR, while the concentration of primers is the same with simplex one. Less than 50bp MPCR products can be separated clearly by 10% non-denaturalized polyacrylamid gel electrophoresis. Fourteen transgenic wheat lines were tested by multiplex and simplex PCR respectively, which shows the same results and hence presents that MPCR is the reliable, rapid and high-effective approach to detect foreign genes from transgenic plant.