Artesunate Reduces Proliferation, Interferes DNA Replication and Cell Cycle and Enhances Apoptosis in Vascular Smooth Muscle Cells

This study examined the effect of artesunate (Art) on the proliferation, DNA replication, cell cycles and apoptosis of vascular smooth muscle cells (VSMCs). Primary cultures of VSMCs were established from aortas of mice and artesunate of different concentrations was added into the medium. The number of VSMCs was counted and the curve of cell growth was recorded. The activity of VSMCs was assessed by using MTT method and inhibitory rate was calculated. DNA replication was evaluated by [^3H]-TdR method and apoptosis by DNA laddering and HE staining. Flowmetry was used for simultaneous analysis of cell apoptosis and cell cycles. Compared with the control group. VSMCs proliferation in Art interfering groups were inhibited and [^3H]-TdR incorprating rate were decreased as well as cell apoptosis was induced. The progress of cell cycle was blocked in G0/G1 by Art in a dose-dependent manner. It is concluded that Art inhibits VSMCs proliferation by disturbing DNA replication, inducing cell apoptosis and blocking cell cycle in G0/G1 phase.     

Inhibition of cellular proliferation and induction of apoptosis in human esophageal carcinoma cell lines by extracts of Dioscorea bulbifera L and Chinese Angelica

Objective: To investigate the antiproliferative and apoptogenic activities of polysaccharides extracted from Dioscorea bulbifera L (DBP) and Chinese Angelica (CAP) and a 3:2 mixture of these compounds (DCCP) on two esophageal carcinoma cell lines, EC9706 and Eca109. Methods: A MTT assay was used to detect the effects of DBP (10 μg/ml and 100 μg/ml), DCCP(17 μg/ml and 170 μg/ml) and CAP (10 μg/ml and 100 μg/ml) on the proliferation of EC9706 and Eca109 cells. DNA content analysis by flow cytometry was used to determine the cell cycle distribution, and Annexin V-FITC/PI stained fluorescence-activated cell sorter (FACS) was used to detect the apotosis rate of treated cells. Western blots were used to examine protein levels. Results: DBP and DCCP strongly inhibited the proliferation and viability of both the EC9706 and Eca109 cells. CAP enhanced the effects of DBP. DCCP primarily arrested the EC9706 and Eca109 cells at the G1 phase of the cell cycle. DCCP induced apoptosis in both esophageal carcinoma cell lines, and reduced the expression of pIκBα and Bcl-2 proteins. Conclusion: DCCP triggered apoptosis in esophageal carcinoma cells by inhibiting the NF-κB signaling pathway.     

The role of NF-κB in hepatocellular carcinoma cell

Objective To evaluate the role of nuclear factor-kappaB (NF-κB) and IκBα in hepatocellular cacinoma (HCC) SMMC7721 cells, the consequence of NF-κB inhibition in SMMC7721 cells transfected with mutated IκBα (mIκBα) plasmid and the effect of stable inhibition of NF-κB activity in combination with Doxorubicin.Methods Western blot was used to determine the expression of NF-κB and IκBα in SMMC7721 cells and normal liver cells. Nuclear protein was used to evaluate the binding of the 32P-labeled tandem κB sequence using electrophoretic mobility shift assay and the expression of NF-κB using Western blot between SMMC7721 cells transfected with mIκBα plasmid (SMMC7721-MT) and control cells. Furthermore, cell viability was plotted between SMMC7721-MT and control cells. The binding of κB sequence and cell viability between SMMC7721-MT and control cells at different concentrations of Doxorubicin were also investigated.Results Western blot analysis for nuclear extract showed more P50 (NF-κB1) and P65 (RelA) expression in SMMC7721 cells compared with normal liver cells. The expression of cytosolic IκBα protein in SMMC7721 cells was less than that in normal cells. SMMC7721-MT cells inhibited NF-κB nuclear translocation at 0, 24, 48 and 96 hours. Furthermore, NF-κB cannot be detected in the nuclear protein of SMMC7721-MT cells by Western blot. By calculating cell viability, the proliferation of SMMC7721-MT cells was shown to be suppressed more significantly than that of control cells. NF-κB in untransfected cells was activated by Doxorubicin in a dose-dependent manner, but that in SMMC7721-MT cells was not induced at low concentrations of Doxorubicin. Compared with untransfected cells, the viability of SMMC7721-MT cells was significantly suppressed at the same concentration of Doxorubicin (P<0.01）.Conclusions The present study demonstrates that upregulation of NF-κB and downregulation of inhibitory kappaB (IκBα) in SMMC7721 cells are related with the growth of hepatocellular cacinoma cells. Stable expression of mIκBα in SMMC7721-MT cells can inhibit NF-κB nuclear translocation and suppress cell growth. Furthermore, stable inhibition of NF-κB activity in combination with Doxorubicin can significantly inhibit cell proliferation in SMMC7721-MT cells. Thus, modulation of NF-κB may represent an improvement in the efficacy of HCC therapies and be worthy of further research and investigation.     

Effect of Quercetin on Proliferation and Apoptosis of Human Nasopharyngeal Carcinoma HEN1 Cells

The effect of quercetin （Que） on proliferation and apoptosis of human nasopharyngeal carcinoma HEN1 cells was investigated. Inhibition rate of quercetin on HEN1 was assayed by MTT method, apoptosis by flow cytometry （FCM）, and the caspase-3 expression of each group by colorimetry set respectively. Quercetin inhibited HEN1 cells in in a dose-（r=0.709, P〈0.01） and time-dependent manner （r=0.703, P〈0.01）. The ratio of apoptotic and necrosis cells was increased in the cells treated with quercetin. Cell cycle was specificly arrested in G2/M phase. Apoptosis cusp was revealed by FCM. The activity of caspase-3 was significantly up-regulated in 5 groups treated with quecetin as compared with control group （P〈0.05）. It was concluded that the growth inhibition of quercetin was highly related to cell cycle arrest at the G2/M phase and induction of caspase-dependent apoptosis in human nasopharyngeal carcinoma HEN 1 cells.     

Over-expression of LRIG3 suppresses growth and invasion of bladder cancer cells

The purpose of this study was to investigate the impact of leucine-rich repeats and immunoglobulin-like domains 3 (LRIG3) on the biological features of bladder cancer cell lines. The plasmids of over-expressed LRIG3 and the blank plasmid serving as control were transfected into the bladder cancer cell lines, T24, EJ and BIU-87, and the expression levels of LRIG3 mRNA and protein were detected by using real-time PCR and Western blotting. The changes in the cell cycle and apoptosis were examined by using flow cytometry. The invasive ability was measured by Transwell assay, and CCK-8 assays were used to measure the proliferation of cells. As compared with the control group, the LRIG3 mRNA and protein expression levels in LRIG3 cDNA-transfected group were raised significantly (P<0.05). The average number of cells with up-regulated LRIG3 passing through the inserted filter was decreased significantly as compared with the control group (P<0.05). Up-regulation of LRIG3 also could inhibit proliferation and induce apoptosis of T24, EJ and BIU-87 cells. Except BIU-87, the T24 and EJ cells transfected with LIRG3 cDNA were arrested in G 0 /G 1 phase compared to the control group (P<0.05). In conclusion, the over-expression of LRIG3 could influence the cell cycle and invasion, inhibit proliferation and induce apoptosis in the three bladder cancer cell lines.     

Effects of Trichostatin A on HDAC8 Expression, Proliferation and Cell Cycle of Molt-4 Cells

The effects of Trichostatin A (TSA) on histone deacetylase 8 (HDAC8) expression, proliferation and cell cycle arrest in T-lymphoblastic leukemia cell line Molt-4 cells in vitro were investigated. The effect of TSA on the growth of Molt-4 cells was studied by MTT assay. Flow cytometry was used to examine the cell cycle. The expression of HDAC8 was detected by using immunocyto-chemistry and Western blot. The results showed that proliferation of Molt-4 cells was inhibited in TSA-treated group in a time- and dose-dependent manner. The IC50 of TSA exposures for 24 h and 36 h were 254.3236 and 199.257μg/L respectively. The cell cycle analysis revealed that Molt-4 was mostly in G0/G1 phase, and after treatment with TSA from 50 to 400μg/L for 24 h, the percents of G0/G1 cells were decreased and cells were arrested in G2/M phase. Treatment of TSA for 24 h could significantly inhibit the expression of HDAC8 protein in Molt-4 cells (P<0.01). It was concluded that TSA could decrease the expression of HD AC8 in Molt-4 cells, which contributed to the inhibition of proliferation and induction of cell cycle arrest in Molt-4 cells.     

The effect of endogenous transforming growth factor β_1 on the growth of bladder cancer cells in vitro

Objective To investigate the influence of endogenous transforming growth factor β1(TGFβ1) on the cell cycle regulation and proliferation of bladder cancer. Methods A constructed replication defective retroviral vector pRevTβ-AS, which carried antisense RNA of TGFβ1.was transfected to a bladder cancer cell line EJ. The proliferation and clone-formation of transferred cells were observed in vitro,and the alteration of cell cycle was also detected by flow cytometric analysis. Results TGFβ1 antisense RNA was transferred into EJ cell and expressed efficiently. After the inhibition of target gene expression in EJ cells, the reduced growth and clone-formation rates were demonstrated, and the proliferative indexes were decreased by 12 % . The ratios of GO and G1 stage cells to June 2003 Vol12 No2 the antisense RNA-transfected EJ cells were increased, simultaneously,the ratio of S stage cells to the antisense RNA-transfected EJ cells ratios were decreased, compared with the control group. Conclusion The pro     

Anticancer Activities of Trichostatin A on Maligant Lymphoid Cells

The anticancer activity of trichostain A (TSA) on human B cell non-Hodgkin's lymphoma and its mechanism were explored. The effect of TSA on the growth of Raji cells and normal peripheral blood mononuclear cells (NPBMNC) was studied by MTT assay. The effect of TSA on the apoptosis of Raji cells and NPBMNC was studied by flow cytometry and TDT-mediated dUTP nick end labeling (TUNEL). The effect of TSA on the cell cycle of Raji cells was studied by propidium iodide method. The results showed that TSA potently inhibited proliferation of Raji cells at microgram concentrations and induced apoptosis of Raji cells in a time- and concentration-dependent manner. Treatment with TSA induced accumulation of cells in G0/G1 or G2/M and a concomitant decrease of cell population in S phase. However, NPBMNC was less sensitive to the cytotoxic effect of TSA than Raji cells. It was concluded that TSA may inhibit the proliferation of Raji cells by regulating the cell cycle and inducing the cell apoptosis. Moreover, TSA demonstrates low toxicity in NPBMNC but selectively induces apoptosis of Raji cells.     

Trichostatin A Regulates hGCN5 Expression and Cell Cycle on Daudi Cells in vitro

The expression of human general control of amino acid synthesis protein 5 (hGCN5) in human Burkitt's lymphoma Daudi cells in vitro, effects of Trichostatin A (TSA) on cell proliferation and apoptosis and the molecular mechanism of TSA inhibiting proliferation of Daudi cells were investigated. The effects of TSA on the growth of Daudi cells were studied by 3-(4, 5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium (MTT) assay. The effect of TSA on the cell cycle of Daudi cells was assayed by a propidium iodide method. Immunochemistry and Western blot were used to detect the expression of hGCN5. The proliferation of Daudi cells was decreased in TSA-treated group with a 24 h IC50 value of 415.3979μg/L. TSA induced apoptosis of Daudi cells in a time- and dose-dependent manner. Treatment with TSA (200 and 400μg/L) for 24 h, the apoptosis rates of Daudi cells were (14.74±2.04) % and (17.63±1.25) %, respectively. The cell cycle was arrested in G0/G1 phase (50, 100μg/L) and in G2/M phase (200μg/L) by treatment with TSA for 24 h. The expression of hGCN5 protein in Daudi cells was increased in 24 h TSA-treated group by immu-nochemistry and Western blot (P<0.05). It was suggested that TSA as HDACIs could increase the expression of hGCN5 in Daudi cells, and might play an important role in regulating the proliferation and apoptosis of B-NHL cell line Daudi cells.     

Induction of apoptosis and inhibition of proliferation in Hep-2 by antisense survivin RNA in vitro

Objective.. To study induction of apoptosis and inhibition of proliferation in Hep-2 by antisense survivin RNA. Methods： Antisense survivin RNA expression vector was constructed and then was transfected to human laryngeal carcinoma cell line Hep-2 by lipofectamine. HpEGFP/survivin cells （transfected with the combinant of antisense survivin RNA） were obstained by using G418. The levels of survivin protein before and after transfection were determined by Western-blot. Proliferation activity was measured by MTT assay. The experiment of colony formation in soft agar was carried out for assessing ability of proliferation of Hep-2 cell. Apoptosis was assessed by flow cytometry and acrdine orange（AO）. Results： After antisense survivin RNA plasmids were transfected, the level of survivin protein was inhibited in Hep-2. Compared with control, proliferation of HpEGFP/survivin cells were suppressed significantly. The experiment of colony formation in soft agar showed the ability of colony formation decreased in HpEGFP/survivin cells compared to control （P〈0.05）. Apoptosis rate increased about 1.81-folds compared with control. Conclusion.. The antisense survivin RNA can partly inhibit the level of surviivin protein expression in Hep-2 and can induce apoptosis and inhibit the proliferation of Hep-2 by down-regulating the expression of endogenous survivin in vitro.     

Resveratrol Inhibits the Secretion of Vascular Endothelial Growth Factor and Subsequent Proliferation in Human Leukemia U937 Cells

This study examined the effect of resveratrol on the secretion of vascular endothelial growth factor(VEGF) and subsequent proliferation of human leukemia U937 cells,and explored the mechanisms involved.Human leukemia U937 cells were treated with resveratrol of different concentrations(12.5-200 μmol/L) for different time lengths(12-48 h).The proliferation of the U937 leukemic cells was determined by MTT assay.Apoptosis was observed by Annexin-Ⅴ-FIFC/PI double staining and flow cytometry(FCM).Cells cycle was analyzed by PI staining and FCM.The content of VEGF was determined by ELISA.Human umbibical vein endothelial cells were examined for vasoformation in vitro after exposures to resveratrol of various concetrations.The results showed that resveratrol inhibited the proliferation of U937 leukemia cells in a dose-and time-dependent manner.Resveratrol induced apoptosis and S-phase cell cycle arrest in human leukemic U937 cells.Resveratrol inhibited the secretion of VEGF in U937 cells.Resveratrol inhibited the vasoformation of human vein endothelial cells in a dose-dependent manner.It was concluded that resveratrol could down-regulate the secretion of VEGF,induce apoptosis and suppress the proliferation of U937 cells.     

Discovery of chrysoeriol,a PI3K-AKT-mTOR pathway inhibitor with potent antitumor activity against human multiple myeloma cells <Emphasis Type="Italic">in vitro</Emphasis>

This study was designed to determine the impact of chrysoeriol on proliferation and cell cycle progression in the human multiple myeloma cell lines RPMI 8226 and KM3,and its related molecular mechanisms.Chryseoriol was identified by using the phosphorylated AKT-specific cytoblot high throughput assay.CCK-8 assay was employed to examine the growth inhibition rate and IC 50 (48 h) in peripheral blood mononuclear cells (PBMNCs),RPMI 8226 and KM3 cells treated with chrysoeriol at various concentrations.Cells were labeled with 5-6-carboxyfluorescein diacetate succinimidyl ester (CFSE),and the proliferation dynamics was detected by flow cytometry and analyzed with ModFit software.The cell cycles of RPMI 8226 and KM3 cells were measured by flow cytometry when the IC 50 concentration of chrysoeriol was adopted.The alterations in cell-cycle related proteins (Cyclin B1,Cyclin D1,p21) and proteins in PI3K-AKT-mTOR pathway were determined by Western blot analysis.The results showed the proliferation of multiple myeloma cells was significantly inhibited by chrysoeriol,resulting in cell cycle arrest in G 2 /M phase.Chrysoeriol could significantly reduce the expression of p-AKT (s473) and p-4eBP1 (t37/46) protein,meanwhile enhanced Cyclin B1 and p21 protein expression.Similar effects were not observed in PBMNCs from normal donors.It was concluded that chrysoeriol was a selective PI3K-AKT-mTOR pathway inhibitor.It restrained the proliferation of human multiple myeloma cells,but didn’t affect proliferation of PBMNCs from normal donors.It might exhibit the cell cycle regulatory effect via the inhibition of PI3K-AKT-mTOR signal pathway.     

Expression and Fuactional Role of HERG1, K~+ Channels in Leukemic Cells and Leukemic Stem Cells

In order to investigate the expression and functional role of HERG1 K channels in leukemic cells and leukemic stem cells (LSCs), RT-PCR was used to detect the HERG1 K channels expression in leukemic cells and LSCs. The functional role of HERG1 K channels in leukemic cell proliferation was measured by MTT assay, and cell cycle and apoptosis were analyzed by flow cy- tometry. The results showed that herg mRNA was expressed in CD34 /CD38-, CD123 LSCs but not in circulating CD34 cells. Herg mRNA was also up-regulated in leukemia cell lines K562 and HL60 as well as almost all the primary leukemic cells while not in normal peripheral blood mononuclear cells (PBMNCs) and the expression of herg mRNA was not associated with the clinical and cytoge- netic features of leukemia. In addition, leukemic cell proliferation was dramatically inhibited by HERG K channel special inhibitor E-4031. Moreover, E-4031 suppressed the cell growth by induc- ing a specific block at the G1/S transition phase of the cell cycle but had no effect on apoptosis in leukemic cells. The results suggested that HERG1 K channels could regulate leukemic cells prolif- eration and were necessary for leukemic cells to proceed with the cell cycle. HERG1 K channels may also have oncogenic potential and may be a biomarker for diagnosis of leukemia and a novel potential pharmacological target for leukemia therapy.     

Induction of apoptosis in human Hep3B hepatoma cells by norcantharidin through a p53 independent pathway via TRAIL/DR5 signal transduction

<正>Objective:To investigate the inhibitory activities of norcantharidin(NCTD),a demethylated analogue of cantharidin,on Hep3B cells(a human hepatoma cell line) with deficiency of p53.Methods:The survival rate of the Hep3B cells after treating with NCTD was measured by MTT assay.Cell cycle of treated cells was analyzed by flow cytometry,and DNA fragmentation was observed by electrophoresis.The influence of inhibitors for various caspases and anti-death receptors antibodies on the NCTD-induced apoptosis in the cells was determined. Results:NCTD treatment resulted in growth inhibition of Hep3B cells in a dose- and time-dependent manner.Cell cycle analysis of the cells after treatment with NCTD for 48 h shows that NCTD induced G_2M phase arrest occurs at low concentration(≤25μmol/L) but G_0G_1 phase arrest at high concentration(50μmol/L).The addition of both caspase-3 and caspase-10 inhibitors completely inhibited DNA fragmentation.Addition of anti-TRAIL/DR5 antibody significantly inhibited DNA fragmentation.Conclusion:NCTD may inhibit the proliferation of Hep3B cells by arresting cell cycle at G_2M or G_0G_1 phase,and induce cells apoptosis via TRAIL/DR5 signal transduction through activation of caspase-3 and caspase-10 by a p53-independent pathway.