Apoptosis plays an important role in embryonic development, tissue remodeling, immune regulation and tumor regression. Two groups of molecules (Bcl-2 family and "Death factor" family) are involved in regulat...Apoptosis plays an important role in embryonic development, tissue remodeling, immune regulation and tumor regression. Two groups of molecules (Bcl-2 family and "Death factor" family) are involved in regulating apoptosis. In order to know about the effect of Bcl-2 on apoptosis induced by Fas, a typical member of "Death factor" family, the transfection experiments with expression vectors pcDNA3-fl and pcDNA3-bcl-2 were performed in BEL-7404 cells, a human hepatocellular carcinoma cell line which expresses endogenous Fas, but not FasL and Bcl-2. The data showed that the expression of FasL in pcDNA3-fl transfected hepatoma cells obviously induced the apoptosis of the cells. However, the overexpression of Bcl-2 in pcDNA3-bcl-2 transfected 7404/b-16 cells counteracted pcDNA3-fl transient transfection mediated apoptosis. Further study by cotransfection experiments indicated that Bid but not Bax (both were pro-apoptotic proteins of Bcl-2 family) blocked the inhibitory effect of Bcl-2 on Fas-mediated apoptosis. These results suggested that Fas-mediated apoptosis in human hepatoma cells is possibly regulated by Bcl-2 family proteins via mitochondria pathway.展开更多
Objective:To study the effects of 18β-glycyrrhetinic acid (GA) on proliferation inhibition, apop totic induction, and the relationship between GA-induced apoptosis and intracellular Ca2+ concentration in human breast...Objective:To study the effects of 18β-glycyrrhetinic acid (GA) on proliferation inhibition, apop totic induction, and the relationship between GA-induced apoptosis and intracellular Ca2+ concentration in human breast carcinoma (MCF-7) cells. Methods: After MCF-7 cells were treated with GA at the concentrations from 50 μmol/L to 250 μmol/L for 24 h, cell viability of proliferation was assessed by MTT assay. After the cells were treated with 100 μmol/L, 150 μmol/L, and 200 μmol/L GA for 24 h, the rates of cell apoptosis were examined by terminal deoxynucleotide transferase mediated dUTP nick-end-labeling method and flow cytometry with Annexin V/propidium iodide fluorescent stain. After the cells treated with 150 μmol/L GA for 24 h, intracellular Ca2+ concentration was measured by Fure-2 fluorescein load method. Results: After the cells were treated with GA at the concentrations from 100 μmol/L to 250 μmol/L, the rates of proliferative inhibition were increased significantly (P<0.05 and P<0.01) in a dose dependent fashion. IC50 of the proliferation inhibition was 234.33 μmol/L. Treated with 100 μmol/L, 150 μmol/L, and 200 μmol/L, the rates of cell apoptosis were increased significantly (P<0.01). Intracellular Ca2+ concentration after treatment with GA was higher evidently than that of control (P<0.05). Conclusion: 18β-glycyrrhetinic acid has the effects of the proliferation inhibition and the apoptotic induction on MCF-7 cells. The rise of intracellular Ca2+ level may be depended on apoptosis induced by GA in MCF-7 cells.展开更多
In order to study the mechanism of the effect of heparin on apoptosis in carcinoma cells, the nasopharyngeal carcinoma cell line CNE2 was used to identify the effect of heparin on apoptosis associated with the express...In order to study the mechanism of the effect of heparin on apoptosis in carcinoma cells, the nasopharyngeal carcinoma cell line CNE2 was used to identify the effect of heparin on apoptosis associated with the expression of c-myc, bax, bcl-2 proteins by use of Hoechst 33258 staining, terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL), agarose gel electrophoresis, and flow cytometry, as well as Western blot analysis. The results showed that heparin induced apoptosis of CNE2 cells including the morphologic changes such as reduction in the volume, and the nuclear chromatin condensation, as well as the 'ladder pattern' revealed by agarose gel electrophoresis of DNA in a concentration-dependent manner. The number of TUNEL-positive cells was dramatically increased to 33.6+/-1.2% from 2.8+/-0.3% by treatment with heparin in different concentrations (10 to approximately 40 kU/L). The apoptotic index was increased to 32.5% from 3.5% by detecting SubG1 peaks on flow cytometry. Western blot analysis showed that levels of bcl-2, bax and c-myc were significantly overexpressed by treatment with the increase of heparin concentrations. These results suggest that heparin induces apoptosis of CNE2 cells, which may be regulated by differential expression of apoptosis-related genes.展开更多
Objective: To elucidate the effects of amlodipine on the proliferation and apoptosis of human breast carcinoma MDA-MB-231 cells. Methods: Light microscopy was used to determine the effects of amlodipine on cell morp...Objective: To elucidate the effects of amlodipine on the proliferation and apoptosis of human breast carcinoma MDA-MB-231 cells. Methods: Light microscopy was used to determine the effects of amlodipine on cell morphology; Flow cytometry was used to quantitate cells undergoing apoptosis; the expression of a cell cycle-related protein, proliferating cell nuclear antigen (PCNA) and an antiapoptosis protein, Bcl-2 were assessed by immunocytochemistry. Results: Amlodipine concentration of 8.25umol/L (1/2 of ICs0) affected the morphology, decreased the expression of PCNA and Bcl-2 and induced apoptosis of human breast carcinoma MDA-MB-231 cells. Conclusion: The effect of amlodipine on the antiproliferation of human breast carcinoma MDA-MB-231 cells is related to inducement of apoptosis, and the decrease of the expression of Bcl-2 and PCNA may be the possible mechanism for proliferation inhibitory and inducement of apoptosis.展开更多
Objective: To explore the effects of matrine on HCCR1 and HCCR2 expression in cultural human hepatocellular carcinomas (HCC) cells at the level of gene and protein. Methods: Three methods, representational differe...Objective: To explore the effects of matrine on HCCR1 and HCCR2 expression in cultural human hepatocellular carcinomas (HCC) cells at the level of gene and protein. Methods: Three methods, representational difference analysis (RDA) of cDNA, microarrays and fluorescence in situ hybridization (FISH) were used to detect levels of mRNA and protein expression of HCCR1 and HCCR-2 before and after treatment of matrine. Results: Matrine had inhibitory effect on the mRNA and protein expression of HCCR1 and HCCR2 in cultural HCC cells. Conclusion: Matrine has inhibitory effect on gene transcription, protein expression of HCCR 1 and HCCR2 in cultural HCC cells.展开更多
Objective To discuss on mechanism of the killing and apoptosis inducing effect induced by total alkaloid in the CSS(Capparis spinosa L.saponin,CSS)on human hepatocarcinoma cell Line HepG-2.Methods The killing effect o...Objective To discuss on mechanism of the killing and apoptosis inducing effect induced by total alkaloid in the CSS(Capparis spinosa L.saponin,CSS)on human hepatocarcinoma cell Line HepG-2.Methods The killing effect of the CSS on human hepatocarcinoma cell Line HepG-2 was observed by MTT method.Morphological observation of the HepG-2 cells was completed by fluorescence microscope.This test was signed to observe the changes of the cell cycle of HepG-2 cells affected by the CSS by PI single-staining,and to observe if there were typical apoptosis peaks.The apoptosis inducing effect and changing of mitochondria membrane potential of the CSS on the HepG-2 cells were studied by flow cytometry.The effect of intracellular Ca2+ level of CSS on the HepG-2 cells was measured by laser confocal microscope.Results CSS has growth inhibiting on the HepG-2 and seems to be enhanced with the increasing concentration of CSS,and its IC50 value was 46.16 μg·mL-1.The HepG-2 cells are characteristic apoptosis morphologic changed,and the apoptosis percentage is increased to 66.652% in the 50 μg·mL-1 dosage group.The cells cycle has been changed obviously that the progresses of cells cycle of G1 period and G2 period in high dosage group have been blocked,and the cellular proportion in G2 period is decreased by the function of CSS for 24 h.The mitochondria membrane potential of HepG-2 cells induced by CSS is decreased in various degrees.In addition,the intracellular Ca2+ level is increased by the function of CSS in the middle and high dose groups.Conclusions The CSS has obviously killing and apoptosis inducing effect on human hepatocarcinoma cell Line HepG-2 by the mechanism of decreasing the mitochondria membrane potential and increasing the intracellular Ca2+ level.展开更多
We report the cloning and functional characterization of human cyclin L2, a novel member of the cyclin family. Human cyclin L2 shares significant homology to cyclin L1, K, T1, T2, and C, which are involved in transcri...We report the cloning and functional characterization of human cyclin L2, a novel member of the cyclin family. Human cyclin L2 shares significant homology to cyclin L1, K, T1, T2, and C, which are involved in transcriptional regulation via phosphorylation of the C-terminal domain of RNA polymerase Ⅱ. The cyclin L2 protein contains an N-terminal "cyclin box" and C-terminal dipeptide repeats of alternating arginines and serines, a hallmark of the SR family of splicing factors. A new isoform and the mouse homologue of human cyclin L2 have also been cloned in this study. Human cyclin L2 is expressed ubiquitously in normal human tissues and tumor cells. We show here that cyclin L2 co-localizes with splicing factors SC-35 and 9G8 within nuclear speckles and that it associates with hyperphosphorylated, but not hypophosphorylated, RNA polymerase Ⅱ and CDK p110 PITSLRE kinase via its N-terminal cyclin domains. It can also associate with the SC-35 and 9G8 through its RS repeat region. Recombinant cyclin L2 protein can stimulate in vitro mRNA splicing. Overexpression of human cyclin L2 suppresses the growth of human hepatocellular carcinoma SMMC 7721 cells both in vitro and in vivo, inducing cellular apoptosis. This process involves up-regulation of p53 and Bax and decreased expression of Bcl-2. The data suggest that cyclin L2 represents a new member of the cyclin family, which might regulate the transcription and RNA processing of certain apoptosis-related factors, resulting in tumor cell growth inhibition and apoptosis.展开更多
Objective: To investigate the expression of K-ras in human laryngeal squamous cell carcinoma cell lines (Hep-2) and its significance for establishing a solid foundation for further study of the relationship between...Objective: To investigate the expression of K-ras in human laryngeal squamous cell carcinoma cell lines (Hep-2) and its significance for establishing a solid foundation for further study of the relationship between human laryngeal squamous cell carcinoma and K-ras gene point mutations. Methods: The expression of K-ras in human laryngeal squamous cell carcinoma cell lines (Hep-2) and human pancreatic carcinoma cell lines (MIAPaCa-2) was detected by using RT-PCR. Results: The expression of K-ras mRNA in Hep-2 and MIAPaCa-2 was strong and positive. Conclusion: The expression of K-ras mRNA in human laryngeal squamous cell carcinoma cell lines (Hep-2) is positive. Development of laryngeal carcinoma might be related to the activation of K-ras gene point mutation.展开更多
AIM: Cyclooxygenase-2 (COX-2) has been suggested to be associated with carcinogenesis. We sought to investigate the effect of the selective COX-2 inhibitor, Nimesulide on proliferation and apoptosis of SMMC-7721 human...AIM: Cyclooxygenase-2 (COX-2) has been suggested to be associated with carcinogenesis. We sought to investigate the effect of the selective COX-2 inhibitor, Nimesulide on proliferation and apoptosis of SMMC-7721 human hepatoma cells.METHODS: This study was carried out on the culture of hepatic carcinoma SMMC-7721 cell line. Various concentrations of Nimesulide (0, 200 micromol/L, 300 micromol/L, 400 micromol/L) were added and incubated. Cell proliferation was detected with MTT colorimetric assay, cell apoptosis by electron microscopy, flow cytometry and TUNEL.RESULTS: Nimesulide could significantly inhibit SMMC-7721 cells proliferation dose-dependent and in a dependent manner compared with that of the control group. The duration lowest inhibition rate produced by Nimesulide in SMMC-7721 cells was 19.06%, the highest inhibition rate was 58.49%. After incubation with Nimesulide for 72 h, the most highest apoptosis rate and apoptosis index of SMMC-7721 cells comparing with those of the control were 21.20%+/-1.62% vs 2.24%+/-0.26% and 21.23+/-1.78 vs 2.01+/-0.23 (P【0.05). CONCLUSION:The selective COX-2 inhibitor, Nimesulide can inhibit the proliferation of SMMC-7721 cells and increase apoptosis rate and apoptosis index of SMMC-7721 cells. The apoptosis rate and the apoptosis index are dose-dependent. Under electron microscope SMMC-7721 cells incubated with 300 micromol and 400 micromol Nimesulide show apoptotic characteristics. With the clarification of the mechanism of selective COX-2 inhibitors, These COX-2 selective inhibitors can become the choice of prevention and treatment of cancers.展开更多
AIM;To investigate the apoptosis in gastric cancer cells induced by paclitaxel,and the relation between this apoptosis and expression of Bcl-2 and Bax. METHODS:In in vitro experiments,MTT assay was used to determine t...AIM;To investigate the apoptosis in gastric cancer cells induced by paclitaxel,and the relation between this apoptosis and expression of Bcl-2 and Bax. METHODS:In in vitro experiments,MTT assay was used to determine the cell growth inhibitory rate.Transmission electron microscope and TUNEL staining method were used to quantitatively and qualitively detect the apoptosis status of gastric cancer cell line SGC-7901 before and after the paclitaxel treatment.Immunohistochemical staining was used to detect the expression of apoptosis-regulated gene Bcl-2 and Bax. RESULTS:Paclitaxel inhibited the growth of gastric cancer cell line SGC-7901 in a dose-and time-dependent manner. Paclitaxel induced SGC-7901 cells to undergo apoptosis with typically apoptotic characteristics,including morphological changes of chromatin condensation,chromatin crescent formation,nucleus fragmentation and apoptotic body formation.Paclitaxel could reduce the expression of apoptosis-regulated gene Bcl-2,and improve the expression of apoptosis-regulated gene Bax. CONCLUSION:Paclitaxel is able to induce the apoptosis in gastric cancer.This apoptosis may be mediated by down- expression of apoptosis-regulated gene Bcl-2 and up- expression of apoptosis-regulated gene Bax.展开更多
BACKGROUND:The glucose transporter-1(Glut-1),a key ratelimiting factor in the transport and metabolism of glucose in cancer cells,is over-expressed in many human cancer cells and this overexpression is correlated with...BACKGROUND:The glucose transporter-1(Glut-1),a key ratelimiting factor in the transport and metabolism of glucose in cancer cells,is over-expressed in many human cancer cells and this overexpression is correlated with poor biological behavior. The increased levels of Glut-1 expression in hepatocellular carcinoma(HCC)cells functionally affect tumorigenicity.This study was undertaken to investigate effects of suppressing Glut-1 by an antisense oligodeoxynucleotide(AS-ODN)on the growth of human hepatocellular carcinoma(HepG-2)cells. METHODS:We used AS-ODN targeting against the Glut-1 gene in a HepG-2 cell line.There were four experimental groups: empty pcDNA3.1 vector(mock transfection),pcDNA3.1-anti-Glut(+),pcDNA3.1-Glut(+),and non-transfected HepG-2 cells. The Glut-1 mRNA expression was detected by RT-PCR and the Glut-1 protein expression by Western blotting after cell culture, and the glucose uptake was detected after glucose stimulation in each group. RESULTS:Compared with non-transfected HepG-2 or Glut-1 pcDNA3.1,a down-regulation of Glut-1 mRNA in HepG-2 cells transfected with anti-Glut-1 pcDNA3.1 was noted(P<0.05).Glut-1 protein in HepG-2 cells transfected with Glut-1 AS-ODN was decreased compared with non-transfected HepG-2,Glut-1 pcDNA3.1,or empty vectors. Glucose uptake by the HepG-2 cells transfected with AS-ODN was decreased at 1 hour after glucose stimulation.CONCLUSIONS:The application of Glut-1 AS-ODN can down-regulate the expression of Glut-1 at mRNA and protein,and inhibit glucose uptake partially in HepG-2 cells.The Glut-1 gene maybe a potential therapeutic target for HCC.展开更多
AIM:To observe the effects of sargentgloryvine stem extracts (SSE) on the hepatoma cell line HepG-2 in vitro andin vivo and determine its mechanisms of action.METHODS:Cultured HepG-2 cells treated with SSE were analys...AIM:To observe the effects of sargentgloryvine stem extracts (SSE) on the hepatoma cell line HepG-2 in vitro andin vivo and determine its mechanisms of action.METHODS:Cultured HepG-2 cells treated with SSE were analysed by 3-(4,5-Dimethyl-thiazol-2-yl)-2,5Diphenyltetrazolium bromide and clone formation assay.The cell cycle and apoptosis analysis were conducted by flow cytometric,TdT-Mediated dUTP Nick End Labeling and acridine orange/ethidium bromide staining methods,and protein expression was examined by both reverse transcriptase-polymerase chain reaction and Western blotting.The pathological changes of the tumor cells were observed by haematoxylin and eosin staining.Tumor growth inhibition and side effects were determined in a xenograft mouse model.RESULTS:SSE treatment could not only inhibit HepG-2 cell proliferation in a doseand time-dependent manner but also induce apoptosis and cell cycle arrest at the S phase.The number of colonies formed by SSEtreated tumor cells was fewer than that of the controls (P<0.05).SSE induced caspase-dependent apoptosis accompanied by a significant decrease in Bcl-xl and Mcl-1 and elevation of Bak expression (P<0.05).Tumor necrosis factor α in the xenograft tumor tissue and the liver functions of SSE-treated mice showed no significant changes at week 8 compared with the control group (P>0.05).Systemic administration of SSE could inhibit the HepG-2 xenograft tumor growth with no obvious toxic side effects on normal tissues.CONCLUSION:SSE can induce apoptosis of HepG-2 cells in vitro and in vivo through decreasing expression of Bcl-xl and Mcl-1 and increasing expression of Bax.展开更多
Objective: To observe the effect of the artesunate (ART) on cellular proliferation in vitro, to search for the possible anti-tumor mechanism of ART on endometrial carcinoma at the molecular level and to provide the...Objective: To observe the effect of the artesunate (ART) on cellular proliferation in vitro, to search for the possible anti-tumor mechanism of ART on endometrial carcinoma at the molecular level and to provide the experimental and theoretical foundations for the clinical applications of ART. Methods: The cell proliferation was observed by microscope; MTT was used to examine the effects of ART on proliferation of HEC-1B cells, and flow cytometric analysis was used to detect cell cycle and apoptosis. The human endometrial carcinoma HEC-1B cells were conventionally cultured; ART was administered with a concentration of 40 μg/ml before the total RNA were extracted, mRNA expression of Survivin, Caspase-3, N-Cadherin, E-Cadherin, Fibronectinl and Cox-2 were detected using RT-PCR. Results: ART reduced proliferation in human endometrial carcinoma cell line HEC-1B in a dose- and time-dependent effect. The cells of G0/G1 stage were significantly increased (P〈0.05), but the cells of G2/M stages were significantly decreased (P〈0.05), so it has shown that the cell cycle was probably blocked in G0/G1 stage. After intervention with ART at 20 and 80 μg/ml for 48 h, cellular apoptosis rate respectively was (36.42±0.77)% and (11.77±0.58)%, and the difference was statistically significant compared with the control ([6.64±0.191%, P〈0.01). The expression of Cox-2 mRNA in the ART group was lower than those of control group, yet the expression of Caspase-3 and E-Cadherin mRNA in the ART group was higher than those of control group. Conclusion: ART can inhibit HEC-1B cell growth and proliferation in a dose- and time-dependent manner. Furthermore, ART can induce apoptosis in a dose-dependent manner. ART is able to downregulate Cox-2 mRNA expression and to upregulate E-Cadherin and Caspase-3 mRNA expression. So we can conclude that ART could induce the endometrial carcinoma HEC-1B cell apoptosis and inhibit tumor cell proliferation.展开更多
Gastrin and cyclooxygenase-2(COX-2) playimportant roles in the carcinogenesis and progression ofgastric cancer.However,it remains unknown whether the combination of cholecystokinin-2(CCK-2) receptor antagonist plus CO...Gastrin and cyclooxygenase-2(COX-2) playimportant roles in the carcinogenesis and progression ofgastric cancer.However,it remains unknown whether the combination of cholecystokinin-2(CCK-2) receptor antagonist plus COX-2 inhibitor exerts synergistic anti-tumor effects on human gastric cancer.Here,we demonstrated that the combination of AG-041R(a CCK-2 receptor antagonist) plus NS-398(a selective COX-2 inhibitor) treatment had synergistic effects on proliferation inhibition,apoptosis induction,down-regulation of Bcl-2 and up-regulation of Bax expression in MKN-45 cells.These results indicate that simultaneous targeting of CCK-2 receptor and COX-2 may inhibit gastric cancer development more effectively than targeting either molecule alone.(C)2008 Elsevier Ireland Ltd.All rights reserved.展开更多
Objective:The aim of this study was to investigate the inhibitory effect of apogossypolone (ApoG2) on subcutaneous implants of human LNCaP prostatic carcinoma cells, and explore its mechanism. Methods:To establish hum...Objective:The aim of this study was to investigate the inhibitory effect of apogossypolone (ApoG2) on subcutaneous implants of human LNCaP prostatic carcinoma cells, and explore its mechanism. Methods:To establish human LNCaP prostatic carcinoma cell line subcutaneous xenograft models and observe the inhibitory effect of ApoG2 on the tumor model. Immunohistochemistry was employed to observe the expression of Bcl-2, PCNA, CD31, caspase-3 and-8 in tumor tissues. The microvessel density was calculated. Results:ApoG2 could obviously inhibit the growth of subcutaneous prostatic carcinoma implant. ApoG2 decreased the expression of PCNA and CD31, and increased the expression of caspases-3,-8 in tumor tissues. Conclusion:ApoG2 has an inhibitory effect on prostatic carcinoma implants.展开更多
Objective: This work aimed to study the inhibitory effect and the related mechanism of metformin (MET) on the proliferation of human hepatoma HepG2 cells. Methods: Human hepatoma HepG2 cells were treated with MET ...Objective: This work aimed to study the inhibitory effect and the related mechanism of metformin (MET) on the proliferation of human hepatoma HepG2 cells. Methods: Human hepatoma HepG2 cells were treated with MET (0, 2, 10, and 50 mM). The inhibitory effect of MET on the proliferation of HepG2 cells was determined by MTT method. The apoptosis of HepG2 cells was detected by flow cytornetry. The expression of cyclin D1 in HepG2 cells was examined by Western blot. ROS-DHE fluorescence probe was used to stain the reactive oxygen species (ROS) generated by HepG2 cells after treat- ment. Results: MET could inhibit the proliferation of HepG2 cells in a dose and time dependent manner. MET promoted the apoptosis of HepG2 cells. In addition, MET suppressed the expression of cell cycle protein cyclin D1 and induced the produc- tion of ROS in HepG2 cells. Conclusion: MET can inhibit the proliferation of human hepatoma HepG2 cells and induce cell apoptosis. Meanwhile, MET has the ability to decrease the expression of cyclin D1 and induce ROS generation, which may be involved in the mechanism of inhibiting hepatoma cells proliferation.展开更多
AIM: To evaluate the receptor protein which can specifically bind to β2GPⅠon the membrane of hepatocellular carcinoma (HCC) cell line SMMC-7721, and to study the biological function of the receptor.METHODS: Through ...AIM: To evaluate the receptor protein which can specifically bind to β2GPⅠon the membrane of hepatocellular carcinoma (HCC) cell line SMMC-7721, and to study the biological function of the receptor.METHODS: Through β2GPⅠ-affinity chromatography column, the peptid-polysome-mRNA complex, which can specially bind to β2GPⅠ, stayed with the column and was separated from the whole polysome of liver cells, and then eluted and collected. Using cDNA synthesis kit and cDNA PCR kit, the corresponding cDNA was obtained and sequenced. RT-PCR was used to amplify annexinⅡ, and flow cytometry was used to study the competitive binding of annexinⅡ with β2GPⅠto SMMC-7721.RESULTS: A total of 1.1 kb of the cDNA fragment of the specific binding protein of β2GPⅠon liver cell membrane was obtained. The sequence of cDNA shared high homology with human annexinⅡ (98%). AnnexinⅡ was expressed on the membrane of SMMC-7721, and could compete with β2GPⅠfor combining with SMMC-7721.CONCLUSION: The receptor for β2GPⅠon membrane of SMMC-7721 cells is annexinⅡ, which might bridge HBV to infect hepatocytes.展开更多
The use of a microwave-assisted extraction (MAE) method for the extraction ofphlorotannins from Saccharinajaponica Aresch (S.japonica) has been evaluated with particular emphasis on the influential parameters, inc...The use of a microwave-assisted extraction (MAE) method for the extraction ofphlorotannins from Saccharinajaponica Aresch (S.japonica) has been evaluated with particular emphasis on the influential parameters, including the ethanol concentration, solid/liquid ratio, extraction time, extraction temperature, and microwave power. The MAE procedure was optimized using single-factor design and orthogonal array design (OAD). The content of total phlorotannins in S. japonica was determined using a Folin-Ciocalteu (FC) assay. A maximum total phlorotannin content of 0.644 mg of phloroglucinol equivalent per gram of dry weight plant (mg PGE/g DW) was obtained using the optimized model, which included an ethanol concentration of 55%, solid/liquid ratio of 1:8, extraction time of 25 min, irradiation power of 400 W, and temperature of 60~C. Under similar conditions, the application of a conventional extraction method led to a lower phlorotarmin yield of 0.585 mg PGE/g WD. These results demonstrated that the MAE approach provided better results for the extraction ofphlorotarmins from S.japonica and was a promising technique for the extraction of phenolic compounds from S. japonica and other materials. In addition, screening tests for the inhibitory activity showed that the phlorotannin-containing extracts significantly inhibited the growth of human hepatocellular carcinoma cells (HepG2) by inducing their apoptosis. The morphological changes that occurred during cell apoptosis were characterized using Hoechst33258 staining.展开更多
基金Major State Basic Reaearch (973) Program of China.
文摘Apoptosis plays an important role in embryonic development, tissue remodeling, immune regulation and tumor regression. Two groups of molecules (Bcl-2 family and "Death factor" family) are involved in regulating apoptosis. In order to know about the effect of Bcl-2 on apoptosis induced by Fas, a typical member of "Death factor" family, the transfection experiments with expression vectors pcDNA3-fl and pcDNA3-bcl-2 were performed in BEL-7404 cells, a human hepatocellular carcinoma cell line which expresses endogenous Fas, but not FasL and Bcl-2. The data showed that the expression of FasL in pcDNA3-fl transfected hepatoma cells obviously induced the apoptosis of the cells. However, the overexpression of Bcl-2 in pcDNA3-bcl-2 transfected 7404/b-16 cells counteracted pcDNA3-fl transient transfection mediated apoptosis. Further study by cotransfection experiments indicated that Bid but not Bax (both were pro-apoptotic proteins of Bcl-2 family) blocked the inhibitory effect of Bcl-2 on Fas-mediated apoptosis. These results suggested that Fas-mediated apoptosis in human hepatoma cells is possibly regulated by Bcl-2 family proteins via mitochondria pathway.
文摘Objective:To study the effects of 18β-glycyrrhetinic acid (GA) on proliferation inhibition, apop totic induction, and the relationship between GA-induced apoptosis and intracellular Ca2+ concentration in human breast carcinoma (MCF-7) cells. Methods: After MCF-7 cells were treated with GA at the concentrations from 50 μmol/L to 250 μmol/L for 24 h, cell viability of proliferation was assessed by MTT assay. After the cells were treated with 100 μmol/L, 150 μmol/L, and 200 μmol/L GA for 24 h, the rates of cell apoptosis were examined by terminal deoxynucleotide transferase mediated dUTP nick-end-labeling method and flow cytometry with Annexin V/propidium iodide fluorescent stain. After the cells treated with 150 μmol/L GA for 24 h, intracellular Ca2+ concentration was measured by Fure-2 fluorescein load method. Results: After the cells were treated with GA at the concentrations from 100 μmol/L to 250 μmol/L, the rates of proliferative inhibition were increased significantly (P<0.05 and P<0.01) in a dose dependent fashion. IC50 of the proliferation inhibition was 234.33 μmol/L. Treated with 100 μmol/L, 150 μmol/L, and 200 μmol/L, the rates of cell apoptosis were increased significantly (P<0.01). Intracellular Ca2+ concentration after treatment with GA was higher evidently than that of control (P<0.05). Conclusion: 18β-glycyrrhetinic acid has the effects of the proliferation inhibition and the apoptotic induction on MCF-7 cells. The rise of intracellular Ca2+ level may be depended on apoptosis induced by GA in MCF-7 cells.
文摘In order to study the mechanism of the effect of heparin on apoptosis in carcinoma cells, the nasopharyngeal carcinoma cell line CNE2 was used to identify the effect of heparin on apoptosis associated with the expression of c-myc, bax, bcl-2 proteins by use of Hoechst 33258 staining, terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL), agarose gel electrophoresis, and flow cytometry, as well as Western blot analysis. The results showed that heparin induced apoptosis of CNE2 cells including the morphologic changes such as reduction in the volume, and the nuclear chromatin condensation, as well as the 'ladder pattern' revealed by agarose gel electrophoresis of DNA in a concentration-dependent manner. The number of TUNEL-positive cells was dramatically increased to 33.6+/-1.2% from 2.8+/-0.3% by treatment with heparin in different concentrations (10 to approximately 40 kU/L). The apoptotic index was increased to 32.5% from 3.5% by detecting SubG1 peaks on flow cytometry. Western blot analysis showed that levels of bcl-2, bax and c-myc were significantly overexpressed by treatment with the increase of heparin concentrations. These results suggest that heparin induces apoptosis of CNE2 cells, which may be regulated by differential expression of apoptosis-related genes.
文摘Objective: To elucidate the effects of amlodipine on the proliferation and apoptosis of human breast carcinoma MDA-MB-231 cells. Methods: Light microscopy was used to determine the effects of amlodipine on cell morphology; Flow cytometry was used to quantitate cells undergoing apoptosis; the expression of a cell cycle-related protein, proliferating cell nuclear antigen (PCNA) and an antiapoptosis protein, Bcl-2 were assessed by immunocytochemistry. Results: Amlodipine concentration of 8.25umol/L (1/2 of ICs0) affected the morphology, decreased the expression of PCNA and Bcl-2 and induced apoptosis of human breast carcinoma MDA-MB-231 cells. Conclusion: The effect of amlodipine on the antiproliferation of human breast carcinoma MDA-MB-231 cells is related to inducement of apoptosis, and the decrease of the expression of Bcl-2 and PCNA may be the possible mechanism for proliferation inhibitory and inducement of apoptosis.
文摘Objective: To explore the effects of matrine on HCCR1 and HCCR2 expression in cultural human hepatocellular carcinomas (HCC) cells at the level of gene and protein. Methods: Three methods, representational difference analysis (RDA) of cDNA, microarrays and fluorescence in situ hybridization (FISH) were used to detect levels of mRNA and protein expression of HCCR1 and HCCR-2 before and after treatment of matrine. Results: Matrine had inhibitory effect on the mRNA and protein expression of HCCR1 and HCCR2 in cultural HCC cells. Conclusion: Matrine has inhibitory effect on gene transcription, protein expression of HCCR 1 and HCCR2 in cultural HCC cells.
文摘Objective To discuss on mechanism of the killing and apoptosis inducing effect induced by total alkaloid in the CSS(Capparis spinosa L.saponin,CSS)on human hepatocarcinoma cell Line HepG-2.Methods The killing effect of the CSS on human hepatocarcinoma cell Line HepG-2 was observed by MTT method.Morphological observation of the HepG-2 cells was completed by fluorescence microscope.This test was signed to observe the changes of the cell cycle of HepG-2 cells affected by the CSS by PI single-staining,and to observe if there were typical apoptosis peaks.The apoptosis inducing effect and changing of mitochondria membrane potential of the CSS on the HepG-2 cells were studied by flow cytometry.The effect of intracellular Ca2+ level of CSS on the HepG-2 cells was measured by laser confocal microscope.Results CSS has growth inhibiting on the HepG-2 and seems to be enhanced with the increasing concentration of CSS,and its IC50 value was 46.16 μg·mL-1.The HepG-2 cells are characteristic apoptosis morphologic changed,and the apoptosis percentage is increased to 66.652% in the 50 μg·mL-1 dosage group.The cells cycle has been changed obviously that the progresses of cells cycle of G1 period and G2 period in high dosage group have been blocked,and the cellular proportion in G2 period is decreased by the function of CSS for 24 h.The mitochondria membrane potential of HepG-2 cells induced by CSS is decreased in various degrees.In addition,the intracellular Ca2+ level is increased by the function of CSS in the middle and high dose groups.Conclusions The CSS has obviously killing and apoptosis inducing effect on human hepatocarcinoma cell Line HepG-2 by the mechanism of decreasing the mitochondria membrane potential and increasing the intracellular Ca2+ level.
文摘We report the cloning and functional characterization of human cyclin L2, a novel member of the cyclin family. Human cyclin L2 shares significant homology to cyclin L1, K, T1, T2, and C, which are involved in transcriptional regulation via phosphorylation of the C-terminal domain of RNA polymerase Ⅱ. The cyclin L2 protein contains an N-terminal "cyclin box" and C-terminal dipeptide repeats of alternating arginines and serines, a hallmark of the SR family of splicing factors. A new isoform and the mouse homologue of human cyclin L2 have also been cloned in this study. Human cyclin L2 is expressed ubiquitously in normal human tissues and tumor cells. We show here that cyclin L2 co-localizes with splicing factors SC-35 and 9G8 within nuclear speckles and that it associates with hyperphosphorylated, but not hypophosphorylated, RNA polymerase Ⅱ and CDK p110 PITSLRE kinase via its N-terminal cyclin domains. It can also associate with the SC-35 and 9G8 through its RS repeat region. Recombinant cyclin L2 protein can stimulate in vitro mRNA splicing. Overexpression of human cyclin L2 suppresses the growth of human hepatocellular carcinoma SMMC 7721 cells both in vitro and in vivo, inducing cellular apoptosis. This process involves up-regulation of p53 and Bax and decreased expression of Bcl-2. The data suggest that cyclin L2 represents a new member of the cyclin family, which might regulate the transcription and RNA processing of certain apoptosis-related factors, resulting in tumor cell growth inhibition and apoptosis.
基金This work was supported by a grant from the National Natural Science Foundation of China(No. 30070809).
文摘Objective: To investigate the expression of K-ras in human laryngeal squamous cell carcinoma cell lines (Hep-2) and its significance for establishing a solid foundation for further study of the relationship between human laryngeal squamous cell carcinoma and K-ras gene point mutations. Methods: The expression of K-ras in human laryngeal squamous cell carcinoma cell lines (Hep-2) and human pancreatic carcinoma cell lines (MIAPaCa-2) was detected by using RT-PCR. Results: The expression of K-ras mRNA in Hep-2 and MIAPaCa-2 was strong and positive. Conclusion: The expression of K-ras mRNA in human laryngeal squamous cell carcinoma cell lines (Hep-2) is positive. Development of laryngeal carcinoma might be related to the activation of K-ras gene point mutation.
文摘AIM: Cyclooxygenase-2 (COX-2) has been suggested to be associated with carcinogenesis. We sought to investigate the effect of the selective COX-2 inhibitor, Nimesulide on proliferation and apoptosis of SMMC-7721 human hepatoma cells.METHODS: This study was carried out on the culture of hepatic carcinoma SMMC-7721 cell line. Various concentrations of Nimesulide (0, 200 micromol/L, 300 micromol/L, 400 micromol/L) were added and incubated. Cell proliferation was detected with MTT colorimetric assay, cell apoptosis by electron microscopy, flow cytometry and TUNEL.RESULTS: Nimesulide could significantly inhibit SMMC-7721 cells proliferation dose-dependent and in a dependent manner compared with that of the control group. The duration lowest inhibition rate produced by Nimesulide in SMMC-7721 cells was 19.06%, the highest inhibition rate was 58.49%. After incubation with Nimesulide for 72 h, the most highest apoptosis rate and apoptosis index of SMMC-7721 cells comparing with those of the control were 21.20%+/-1.62% vs 2.24%+/-0.26% and 21.23+/-1.78 vs 2.01+/-0.23 (P【0.05). CONCLUSION:The selective COX-2 inhibitor, Nimesulide can inhibit the proliferation of SMMC-7721 cells and increase apoptosis rate and apoptosis index of SMMC-7721 cells. The apoptosis rate and the apoptosis index are dose-dependent. Under electron microscope SMMC-7721 cells incubated with 300 micromol and 400 micromol Nimesulide show apoptotic characteristics. With the clarification of the mechanism of selective COX-2 inhibitors, These COX-2 selective inhibitors can become the choice of prevention and treatment of cancers.
文摘AIM;To investigate the apoptosis in gastric cancer cells induced by paclitaxel,and the relation between this apoptosis and expression of Bcl-2 and Bax. METHODS:In in vitro experiments,MTT assay was used to determine the cell growth inhibitory rate.Transmission electron microscope and TUNEL staining method were used to quantitatively and qualitively detect the apoptosis status of gastric cancer cell line SGC-7901 before and after the paclitaxel treatment.Immunohistochemical staining was used to detect the expression of apoptosis-regulated gene Bcl-2 and Bax. RESULTS:Paclitaxel inhibited the growth of gastric cancer cell line SGC-7901 in a dose-and time-dependent manner. Paclitaxel induced SGC-7901 cells to undergo apoptosis with typically apoptotic characteristics,including morphological changes of chromatin condensation,chromatin crescent formation,nucleus fragmentation and apoptotic body formation.Paclitaxel could reduce the expression of apoptosis-regulated gene Bcl-2,and improve the expression of apoptosis-regulated gene Bax. CONCLUSION:Paclitaxel is able to induce the apoptosis in gastric cancer.This apoptosis may be mediated by down- expression of apoptosis-regulated gene Bcl-2 and up- expression of apoptosis-regulated gene Bax.
文摘BACKGROUND:The glucose transporter-1(Glut-1),a key ratelimiting factor in the transport and metabolism of glucose in cancer cells,is over-expressed in many human cancer cells and this overexpression is correlated with poor biological behavior. The increased levels of Glut-1 expression in hepatocellular carcinoma(HCC)cells functionally affect tumorigenicity.This study was undertaken to investigate effects of suppressing Glut-1 by an antisense oligodeoxynucleotide(AS-ODN)on the growth of human hepatocellular carcinoma(HepG-2)cells. METHODS:We used AS-ODN targeting against the Glut-1 gene in a HepG-2 cell line.There were four experimental groups: empty pcDNA3.1 vector(mock transfection),pcDNA3.1-anti-Glut(+),pcDNA3.1-Glut(+),and non-transfected HepG-2 cells. The Glut-1 mRNA expression was detected by RT-PCR and the Glut-1 protein expression by Western blotting after cell culture, and the glucose uptake was detected after glucose stimulation in each group. RESULTS:Compared with non-transfected HepG-2 or Glut-1 pcDNA3.1,a down-regulation of Glut-1 mRNA in HepG-2 cells transfected with anti-Glut-1 pcDNA3.1 was noted(P<0.05).Glut-1 protein in HepG-2 cells transfected with Glut-1 AS-ODN was decreased compared with non-transfected HepG-2,Glut-1 pcDNA3.1,or empty vectors. Glucose uptake by the HepG-2 cells transfected with AS-ODN was decreased at 1 hour after glucose stimulation.CONCLUSIONS:The application of Glut-1 AS-ODN can down-regulate the expression of Glut-1 at mRNA and protein,and inhibit glucose uptake partially in HepG-2 cells.The Glut-1 gene maybe a potential therapeutic target for HCC.
基金Supported by National Science and Technology Key Project for the Development of New Drugs in China,No. 2009ZX09103-422
文摘AIM:To observe the effects of sargentgloryvine stem extracts (SSE) on the hepatoma cell line HepG-2 in vitro andin vivo and determine its mechanisms of action.METHODS:Cultured HepG-2 cells treated with SSE were analysed by 3-(4,5-Dimethyl-thiazol-2-yl)-2,5Diphenyltetrazolium bromide and clone formation assay.The cell cycle and apoptosis analysis were conducted by flow cytometric,TdT-Mediated dUTP Nick End Labeling and acridine orange/ethidium bromide staining methods,and protein expression was examined by both reverse transcriptase-polymerase chain reaction and Western blotting.The pathological changes of the tumor cells were observed by haematoxylin and eosin staining.Tumor growth inhibition and side effects were determined in a xenograft mouse model.RESULTS:SSE treatment could not only inhibit HepG-2 cell proliferation in a doseand time-dependent manner but also induce apoptosis and cell cycle arrest at the S phase.The number of colonies formed by SSEtreated tumor cells was fewer than that of the controls (P<0.05).SSE induced caspase-dependent apoptosis accompanied by a significant decrease in Bcl-xl and Mcl-1 and elevation of Bak expression (P<0.05).Tumor necrosis factor α in the xenograft tumor tissue and the liver functions of SSE-treated mice showed no significant changes at week 8 compared with the control group (P>0.05).Systemic administration of SSE could inhibit the HepG-2 xenograft tumor growth with no obvious toxic side effects on normal tissues.CONCLUSION:SSE can induce apoptosis of HepG-2 cells in vitro and in vivo through decreasing expression of Bcl-xl and Mcl-1 and increasing expression of Bax.
文摘Objective: To observe the effect of the artesunate (ART) on cellular proliferation in vitro, to search for the possible anti-tumor mechanism of ART on endometrial carcinoma at the molecular level and to provide the experimental and theoretical foundations for the clinical applications of ART. Methods: The cell proliferation was observed by microscope; MTT was used to examine the effects of ART on proliferation of HEC-1B cells, and flow cytometric analysis was used to detect cell cycle and apoptosis. The human endometrial carcinoma HEC-1B cells were conventionally cultured; ART was administered with a concentration of 40 μg/ml before the total RNA were extracted, mRNA expression of Survivin, Caspase-3, N-Cadherin, E-Cadherin, Fibronectinl and Cox-2 were detected using RT-PCR. Results: ART reduced proliferation in human endometrial carcinoma cell line HEC-1B in a dose- and time-dependent effect. The cells of G0/G1 stage were significantly increased (P〈0.05), but the cells of G2/M stages were significantly decreased (P〈0.05), so it has shown that the cell cycle was probably blocked in G0/G1 stage. After intervention with ART at 20 and 80 μg/ml for 48 h, cellular apoptosis rate respectively was (36.42±0.77)% and (11.77±0.58)%, and the difference was statistically significant compared with the control ([6.64±0.191%, P〈0.01). The expression of Cox-2 mRNA in the ART group was lower than those of control group, yet the expression of Caspase-3 and E-Cadherin mRNA in the ART group was higher than those of control group. Conclusion: ART can inhibit HEC-1B cell growth and proliferation in a dose- and time-dependent manner. Furthermore, ART can induce apoptosis in a dose-dependent manner. ART is able to downregulate Cox-2 mRNA expression and to upregulate E-Cadherin and Caspase-3 mRNA expression. So we can conclude that ART could induce the endometrial carcinoma HEC-1B cell apoptosis and inhibit tumor cell proliferation.
文摘Gastrin and cyclooxygenase-2(COX-2) playimportant roles in the carcinogenesis and progression ofgastric cancer.However,it remains unknown whether the combination of cholecystokinin-2(CCK-2) receptor antagonist plus COX-2 inhibitor exerts synergistic anti-tumor effects on human gastric cancer.Here,we demonstrated that the combination of AG-041R(a CCK-2 receptor antagonist) plus NS-398(a selective COX-2 inhibitor) treatment had synergistic effects on proliferation inhibition,apoptosis induction,down-regulation of Bcl-2 and up-regulation of Bax expression in MKN-45 cells.These results indicate that simultaneous targeting of CCK-2 receptor and COX-2 may inhibit gastric cancer development more effectively than targeting either molecule alone.(C)2008 Elsevier Ireland Ltd.All rights reserved.
文摘Objective:The aim of this study was to investigate the inhibitory effect of apogossypolone (ApoG2) on subcutaneous implants of human LNCaP prostatic carcinoma cells, and explore its mechanism. Methods:To establish human LNCaP prostatic carcinoma cell line subcutaneous xenograft models and observe the inhibitory effect of ApoG2 on the tumor model. Immunohistochemistry was employed to observe the expression of Bcl-2, PCNA, CD31, caspase-3 and-8 in tumor tissues. The microvessel density was calculated. Results:ApoG2 could obviously inhibit the growth of subcutaneous prostatic carcinoma implant. ApoG2 decreased the expression of PCNA and CD31, and increased the expression of caspases-3,-8 in tumor tissues. Conclusion:ApoG2 has an inhibitory effect on prostatic carcinoma implants.
文摘Objective: This work aimed to study the inhibitory effect and the related mechanism of metformin (MET) on the proliferation of human hepatoma HepG2 cells. Methods: Human hepatoma HepG2 cells were treated with MET (0, 2, 10, and 50 mM). The inhibitory effect of MET on the proliferation of HepG2 cells was determined by MTT method. The apoptosis of HepG2 cells was detected by flow cytornetry. The expression of cyclin D1 in HepG2 cells was examined by Western blot. ROS-DHE fluorescence probe was used to stain the reactive oxygen species (ROS) generated by HepG2 cells after treat- ment. Results: MET could inhibit the proliferation of HepG2 cells in a dose and time dependent manner. MET promoted the apoptosis of HepG2 cells. In addition, MET suppressed the expression of cell cycle protein cyclin D1 and induced the produc- tion of ROS in HepG2 cells. Conclusion: MET can inhibit the proliferation of human hepatoma HepG2 cells and induce cell apoptosis. Meanwhile, MET has the ability to decrease the expression of cyclin D1 and induce ROS generation, which may be involved in the mechanism of inhibiting hepatoma cells proliferation.
基金Supported by The National Nature Science Foundation of China,No. 30070338
文摘AIM: To evaluate the receptor protein which can specifically bind to β2GPⅠon the membrane of hepatocellular carcinoma (HCC) cell line SMMC-7721, and to study the biological function of the receptor.METHODS: Through β2GPⅠ-affinity chromatography column, the peptid-polysome-mRNA complex, which can specially bind to β2GPⅠ, stayed with the column and was separated from the whole polysome of liver cells, and then eluted and collected. Using cDNA synthesis kit and cDNA PCR kit, the corresponding cDNA was obtained and sequenced. RT-PCR was used to amplify annexinⅡ, and flow cytometry was used to study the competitive binding of annexinⅡ with β2GPⅠto SMMC-7721.RESULTS: A total of 1.1 kb of the cDNA fragment of the specific binding protein of β2GPⅠon liver cell membrane was obtained. The sequence of cDNA shared high homology with human annexinⅡ (98%). AnnexinⅡ was expressed on the membrane of SMMC-7721, and could compete with β2GPⅠfor combining with SMMC-7721.CONCLUSION: The receptor for β2GPⅠon membrane of SMMC-7721 cells is annexinⅡ, which might bridge HBV to infect hepatocytes.
基金Supported by the National Natural Science Foundation of China(No.51203028)Rural Science and Technology Correspondent and Technology Service System Construction Projects,Guangdong Province(No.2010A020507001-91)Science and Technology Project of Panyu District,Guangzhou City(No.2010-12-08)
文摘The use of a microwave-assisted extraction (MAE) method for the extraction ofphlorotannins from Saccharinajaponica Aresch (S.japonica) has been evaluated with particular emphasis on the influential parameters, including the ethanol concentration, solid/liquid ratio, extraction time, extraction temperature, and microwave power. The MAE procedure was optimized using single-factor design and orthogonal array design (OAD). The content of total phlorotannins in S. japonica was determined using a Folin-Ciocalteu (FC) assay. A maximum total phlorotannin content of 0.644 mg of phloroglucinol equivalent per gram of dry weight plant (mg PGE/g DW) was obtained using the optimized model, which included an ethanol concentration of 55%, solid/liquid ratio of 1:8, extraction time of 25 min, irradiation power of 400 W, and temperature of 60~C. Under similar conditions, the application of a conventional extraction method led to a lower phlorotarmin yield of 0.585 mg PGE/g WD. These results demonstrated that the MAE approach provided better results for the extraction ofphlorotarmins from S.japonica and was a promising technique for the extraction of phenolic compounds from S. japonica and other materials. In addition, screening tests for the inhibitory activity showed that the phlorotannin-containing extracts significantly inhibited the growth of human hepatocellular carcinoma cells (HepG2) by inducing their apoptosis. The morphological changes that occurred during cell apoptosis were characterized using Hoechst33258 staining.