XB130基因对肝细胞癌细胞增殖的影响及其机制

背景与目的:XB130蛋白在肿瘤细胞增殖和侵袭中有重要作用,但在肝细胞癌(hepatocellular carcinoma,HCC)中的研究却极少,其作用至今仍不清楚。该研究拟探讨XB130基因对HCC细胞增殖能力的影响及其可能的下游机制。方法:采用蛋白[质]印迹法(Western blot)检测HCC细胞系Huh7、HepG2、SNU449及正常肝脏细胞系HL7702内XB130蛋白的表达。将XB130-siRNA转染Huh7细胞后,采用细胞计数试剂盒-8(cell counting kit-8,CCK-8)检测Huh7细胞活性,流式细胞术检测Huh7细胞周期,Western blot检测p-AKT、p-GSK3β、cyclin D1及p-Rb的蛋白表达水平,反转录聚合酶链反应(reverse transcription-polymerase chain reaction,RT-PCR)检测E2F/DP-1的靶基因cyclin E1、c-Myc及PCNA的mRNA表达水平。结果:XB130蛋白在Huh7、Hep G2、SNU449和HL7702细胞中的相对表达量分别为0.66±0.10、0.78±0.11、0.83±0.08和0.32±0.06,各HCC细胞与HL7702细胞的差异均有统计学意义(P均<0.01)。XB130-siRNA转染可成功抑制Huh7细胞中XB130蛋白的表达。沉默XB130后,Huh7细胞活性在72 h后明显减弱(P<0.001),48 h后G0/G1期细胞比例升高,S和G2/M期细胞比例降低(P均<0.01),p-AKT、p-GSK3β、cyclin D1及p-Rb的蛋白表达下降(P均<0.01),cyclin E1、c-Myc及PCNA的mRNA表达下降(P?均<0.001)。结论:XB130通过对细胞周期蛋白及下游转录因子的调控,影响HCC细胞增殖。

Akt1/p27^(kip1) Pathway Mediates Inhibition of LXA_4 on TNF-α-induced Proliferation of Rat Mesangial Cells

Objective:To examine whether lipoxin A 4(LXA 4) has an inhibitory effect on tumor necrosis factor-α(TNF-α)-induced proliferation of glomerular mesangial cells of rat, and explore the molecular mechanisms of signal pathway in LXA 4 actions. Methods: Glomerular mesangial cells of rat were cultured and treated with TNF-α(10 ng/ml), with or without preincubation with LXA 4 at different concentrations. Cell proliferation was evaluated by monotetrazolium (MTT) colorimetric assay. The expression of cyclin E mRNA was measured by RT-PCR. Phosphorylated Akt1(Thr308) and p27 kip1 were analyzed by Western blotting. Results: TNF-α-stimulated proliferation of mesangial cells was inhibited by LXA 4 in a dose-dependent manner. The marked increments in cyclin E mRNA expression induced by TNF-α during proliferation of mesangial cells were down-regulated by LXA 4. Threonine phosphorylated Akt1 proteins at 308 site stimulated by TNF-α was reduced by LXA 4. TNF-α-induced decrements in expression of p27 kip1 proteins was ameliorated by LXA 4 in a dose-dependent manner. Conclusion: TNF-α-induced proliferation of rat mesangial cells can be inhibited by TXA 4 through the mechanism of Akt 1/p27 kip1 pathway-dependent signal transduction.

Influences of Melatonin on the Growth of HeLa Cells

Aim To investigate the influences of melatonin (MT) on the growth of HeLa cells in vitro. Methods Theantiprolfferation activities of MT were evaluated in HeLa cells by means of trypan blue dye exclusion and MTT vital staining.The morphological changes of HeLa cells induced by MT were observed under transmission electronic microscope. Cell divisioncycle influenced by MT was assessed by a flow cytometry. Results MT produced a certain inhibition of HeLa cells at the con-centration of 2 mmol@ L-1 and prolonged the TD. The fraction of cells inhibited was 61.0%. The IC. so of HeLa cells exposed toMT for 96 h was 2.039 mmol@ L- 1. The flow cytometric analyses showed that exposure to MT for 72 h reduced the number ofHeLa cells in phase S. Under electronic microscope, the HeLa cells exposed to MT for 72 h displayed morphological changesof necrosis, apoptosis, more hetero-chromosome and less somatic chromosome. Conclusion MT showed certain influences onthe growth of HeLa cells. Its mechanism may probably be attributable to reduction of the number of cells in phase S.

Effect of ciliary neurotrophic factor on activation of astrocytes in vitro

Objective To observe the activating effect of ciliary neurotrophic factor （CNTF） on astrocyte in vitro. Methods Astrocytes cultured purely from newborn rats. Cerebral cortex was raised in normal and serum deprivation condition with different concentrations （in ng/ml： 0, 2, 20, or 200） of CNTF. After cultured for 24 h, the shape and the cell cycle of astrocytes were examined by immunocytochemistry and flow cytometer, respectively. Results The immunoactivity of glial fibrillary acidic protein （GFAP） and the nuclear size of astrocytes were increased when CNTF was applied, whether cells were cultured in medium with or without serum. CNTF promoted astrocytes to enter the cell cycle in medium with serum, but had no this effect in medium without serum. Conclusion In medium without serum, astrocytes could differentiate into activated state ceils with CNTF application, but could not proliferate; in medium with serum, astrocytes could proliferate with aid of CNTF.

Selective COX-2 inhibitor,NS-398,suppresses cellular proliferation in human hepatocellular carcinoma cell lines via cell cycle arrest

AIM: To investigate the growth inhibitory mechanism of NS-398, a selective cyclooxygenase-2 (COX-2) inhibitor, in two hepatocellular carcinoma (HCC) cell lines (HepG2 and Huh7). METHODS: HepG2 and Huh7 cells were treated with NS-398. Its effects on cell viability, cell proliferation, cell cycles, and gene expression were respectively evaluated by water-soluble tetrazolium salt (WST-1) assay, 4’-6-diamidino-2-phenylindole (DAPI) staining, flow cytometer analysis, and Western blotting, with dimethyl sulfoxide (DMSO) as positive control. RESULTS: NS-398 showed dose- and time-dependent growth-inhibitory effects on the two cell lines. Proliferating cell nuclear antigen (PCNA) expressions in HepG2 and Huh7 cells, particularly in Huh7 cells were inhibited in a time- and dose-independent manner. NS-398 caused cell cycle arrest in the G1 phase with cell accumulation in the sub-G1 phase in HepG2 and Huh7 cell lines. No evidence of apoptosis was observed in two cell lines. CONCLUSION: NS-398 reduces cell proliferation by inducing cell cycle arrest in HepG2 and Huh7 cell lines, and COX-2 inhibitors may have potent chemoprevention effects on human hepatocellular carcinoma.

Fascin promotes the motility and invasiveness of pancreatic cancer cells

AIM:To explore the role of actin-bundling protein, fascin during the progression of pancreatic cancer. METHODS:The plasmid expressing human fascin-1 was stably transfected into the pancreatic cancer cell line MIA PaCa-2. The proliferation, cell cycle, motility, scattering, invasiveness and organization of the actin filament system in fascin-transfected MIA PaCa-2 cells and control non-transfected cells were determined. RESULTS:Heterogeneous overexpression of fascin markedly enhanced the motility, scattering, and inva-siveness of MIA PaCa-2 cells. However, overexpression of fascin had minimal effect on MIA PaCa-2 cell pro-liferation and cell cycle. In addition, cell morphology and organization of the actin filament system were distinctly altered in fascin overexpressed cells. When transplanted into BALB/c-nu mice, fascin-transfected pancreatic cancer cells developed solid tumors at a slightly slower rate, but these tumors displayed more aggressive behavior in comparison with control tumors. CONCLUSION: Fascin promotes pancreatic cancer cell migration, invasion and scattering, thus contributes to the aggressive behavior of pancreatic cancer cells.

Lamprey buccal gland secretory protein-2 (BGSP-2) inhibits human T lymphocyte proliferation

Lamprey is a representative of the agnathans, the most ancient class of vertebrates. Parasitic lampreys secrete anticoagulant from their buccal glands and prevent blood coagulation of host fishes. We identified a buccal gland secretory protein-2 （BGSP-2） from a buccal gland cDNA library of Larnpetrajaponica. The full-length BGSP-2 gene was cloned and the recombinant BGSP-2 protein was generated. The role of BGSP-2 on lymphocyte proliferation was studied by examining its effects on human T lymphocytes. We found that lamprey BGSP-2 was able to effectively block the proliferation of T cells in vitro by inducing G1/S cell cycle arrest. Furthermore, it inhibited the proliferation of hmnan T lymphocytes stimulated by phytohemagglutinin （PHA） at a minimum concentration of 0.1μg/ml. Our data suggest that lamprey BGSP-2 is able to block the mitosis of human T lymphocytes at the G1/S point, and has the potential of anti-proliferative effect on PHA-activated T lymphocytes.

Effects of HMGB1 Expression Suppressed by siRNA on Cell Cycle and Proliferation of Human Cervical Cancer Cell Line HeLa

OBJECTIVE In this study, RNA interference was used to evaluate the effects of HMGB1 expression on cell cycle and proliferation of the human cervical cancer cell line HeLa.METHODS We had previously constructed and screened effective eukaryotic expression vectors carrying PGCsi3.0-1/ HMGB1 siRNA and PGCsi3.0-3/HMGB1 siRNA, then the vectors were transfected into HeLa cells. The expression of HMGB1 before and after transfection in HeLa cells were detected by RT-PCR and Western blot. The cell viability and proliferating activity was tested by Trypan blue dye test and MTT, and the cell cycle was determined bv flow cvtometry.RESULTS The introduction of PGCsi3.0-1/HMGB1 siRNA and PGCsi3.0-3/HMGB1 siRNA inhibited the expression of HMGB1 mRNA and protein efficiently and specifically, there was a significant difference between the siRNA groups and the control groups （P 〈 0.05）. The proliferation speed of PGCsi3.0-1 group and PGC si3.0-3 group were obviously slower than those of PGCsi3.0- Neg group and non-transfected group. Flow cytometry showed that the content of DNA in G2 phase in PGCsi3.0-1 group and PGCsi3.0-3 group were obviously more than those in PGCsi3.0- Neg group and non-transfected group, but the content in S phase was less （P 〈 0.01）. The progression of cell cycle was arrested from G2 to S phase.CONCLUSION PGCsi3.0-1/HMGB1 siRNA and PGCsi3.0-3 /HMGB1 siRNA could specially suppress the expression of HMGB1 gene, inhibit the proliferation speed of HeLa cells effectively, and arrest the progression of cell cycle from G2 to S phase. RNAi provides a new approach to the bio-therapy of cervical cancer.

Cell proliferation of esophageal squamous epithelium in erosive and non-erosive reflux disease

AIM： To elucidate cell proliferation in erosive reflux disease （ERD） and non-erosive reflux disease （NERD）, we evaluated markers in squamous epithelial cells.METHODS： Thirty-four consecutive patients with gas- troesophageal-reflux-disease-related symptoms （21 NERD and 13 ERD） were evaluated for the enrolment into the study. All patients underwent 24-h pH moni- toring, standard endoscopy, and biopsy for histological evaluation. The expression of cyclins D and A was eval- uated by real-time reverse transcription polymerase chain reaction （RT-PCR） from isolated epithelial cells. In all samples, analysis of the isolated cell population revealed the presence of epithelial cells only.RESULTS： Real-time RT-PCR showed that, in patientswith ERD, the relative expression of cyclin D1 mRNA in esophageal epithelium was strongly decreased in comparison with NERD patients. The mean value of relative expression of cyclin D1 mRNA in NERD patients was 3.44 ± 1.9, whereas in ERD patients, it was 1.32 ± 0.87 （P = 0.011）. Real-time RT-PCR showed that, in patients with ERD, relative expression of cyclin A mRNA in esophageal epithelium was decreased in comparison with that in NERD patients （2.31 ± 2.87 vs 0.66 ± 1.11）. The mean bromodeoxyuridine labeling index in the NERD patients was 5.42% ± 1.68%, whereas in ERD patients, it was 4.3% ± 1.59%.

Effects of STI571 and p27 gene clone on proliferation and apoptosis of K562 cells

AIM: To investigate the combined effect of STI571 and p27 gene clone on the regulation of proliferation, cell cycle and apoptosis of K562 cell line.METHODS: p27 gene was obtained by RT-PCR, and its sequence was approved to be correct. Then p27-pcDNA3.1 vector was constructed and transfected into K562 cell line.p27-pcDNA3.1-K562 cell clone was screened by G418 after transfection, p27 protein was identified by Western blot.MTT was used to detect the survival rate of the cell. Flow cytometry was used to detect cell cycle and apoptosis index.RESULTS: The expression of p27 protein could be detected by Western blot in p27-pcDNA3.1-K562 cells. A strong inhibition of cell proliferation was observed in p27-pcDNA3.1-K562 cells as compared with that of the control (pcDNA3.1-K562 cells). The cells at G0/G1 phase were significantly increased, and cells at S phase were greatly declined.The apoptosis index was increased greatly after p27-pcDNA3.1-K562 cells were treated with STI571, and survival rate of the cell was markedly declined (0.35-0.58,P<0.05-0.048 vs STI571-K562 cell, 0.35-0.72, P<0.01-0.001 vs p27-K562 cell).CONCLUSION: p27 and STI571 have a synergistic action on inhibition of proliferation and induction of apoptosis on K562 cells.

Interaction of major genes predisposing to hepatocellular carcinoma with genes encoding signal transduction pathways influences tumor phenotype and prognosis

Studies on rodents and humans demonstrate an inherited predisposition to hepatocellular carcinoma （HCC）. Analysis of the molecular alterations involved in the acquisition of a phenotype resistant or susceptible to hepatocarcinogenesis showed a deregulation of G1 and S phases in HCC of genetically susceptible F344 rats and a G1-S block in lesions of resistant Brown norway （BN） rats. Unrestrained extracellular signal-regulated kinase （ERK） activity linked to proteasomal degradation of dual-specificity phosphatase 1 （DUSP1）, a specific ERK inhibitor, by the CKS1-SKP2 ubiquitin ligase complex occurs in more aggressive HCC of F344 rats and humans. This mechanism is less active in HCC of BN rats and human HCC with better prognosis. Upregulation of iNos cross-talk with IKK/NF-KB and RAS/ERK pathways occurs in rodent liver lesions at higher levels in the most aggressive models represented by HCC of F344 rats and c-Myc-TGF-α transgenic mice. iNOS, IKK/NF-κB, and RAS/ERK upregulation is highest in human HCC with a poorer prognosis and positively correlates with tumor proliferation, genomic instability and microvascularization, and negatively with apoptosis. Thus, cell cycle regulation and the activity of signal transduction pathways seem to be modulated by HCC modifier genes, and differences in their efficiency influence the susceptibility to hepatocarcinogenesis and probably the prognosis of human HCC.

The effect of Survivin antioligonucleotide on the apoptosis of Xuanwei lung adenocarcinoma cell

Objective:The aim of the study was to investigate the effects of Survivin antioligonucleotide on the proliferation,apoptosis and cell cycle of Xuanwei lung adenocarcinoma cell XWLC-05.Methods:Specific targeting Survivin ASODN was composed firstly.XWLC-05 would be divided into 4 groups:Group Sham(blank),Group Lip(simple liposome),Group Lip-SODN(transfected sense oligonucleotide) and Group Lip-ASODN(transfected ASODN).All groups had been transfected under the same condition for 48 hours.Then West blotting was used to check the expression of Survivin in cells from different groups and flow cytometer was used to find out the apoptosis rate of cells in different groups.Results:The expression of XWLC-05 Survivin in Group Lip-ASODN decreased obviously and apoptosis rate was significantly higher than that of other groups(P < 0.05).Conclusion:XWLC-05 transfected by Survivin ASODN could down regulate the expression of Survivin and lower expression of Survivin might lead to the apoptosis of XWLC-05 and restrain the proliferation of cancer cells.

Impact of Cinobufacini injection on proliferation and cell cycle of human hepatoma HepG-2 cells

Objective： The aim of our study was to investigate the effect of Cinobufacini injection on the proliferation and cell cycle of human hepatoma HepG-2 cells. Methods： Cell proliferation was assessed by MTT assay, cell cycle distribution was detected by the flow cytometry （FCM）. The expression of Cyclin A, CDK2 mRNA levels were examined by RT-PCR. Quantitative colorimetric assay was used to analyze Cyclin NCDK2 activity in HepG-2 cells. Results： Cinobufacini injection significantly inhibited HepG-2 cells proliferation in dose- and time-dependent ways; FCM analysis showed Cinobufacini injection induced cell cycle arrest at S phase; RT-PCR assay showed Cinobufacini injection down-regulated Cyclin A, CDK2 expression at mRNA levels; Quantitative colorimetric assay showed Cinobufacini injection deceased Cyclin NCDK2 activity in HepG-2 cells. Conclusion： Cinobufacini injection can inhibit human hepatoma HepG-2 cells growth, induce cell apoptosis and induce cell cycle arrest at S phase, the mechanism of which might be partly related to the down-regulation of Cyclin A, CDK2 mRNA expression and inhibition of Cyclin A/CDK2 activity.

Inhibitory effect of metformin on the proliferation of human hepatoma HepG2 cells and its potential mechanism

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.

Effect of three suture lines on the proliferation and cell cycle of lung adenocarcinoma cell A549 in vitro

Objective： The interaction of cell and medical biomaterial is one of the significant factors to affect clinical application of medical biomaterial. This research is to investigate three of suture lines how to affect the proliferation and cell cycle of lung adenocarcinoma cell A549 in vitro. Methods： Three of suture lines were respectively cultivated with lung adenocarcinoma cell A549, after of 72 hours, we detected absorptions of each group by MTT method in order to reflect the proliferation of lung adenocarcinoma cell A549, and also examined percentage of G1 period cells and S period cells of each group by flow cytometry. Results： Different of suture lines had different effects on the proliferation and cell cycle of lung adenocarcinoma cell A549 （P 〈 0.05）. The effect of absorbent suture line was the strongest on the proliferation and cell cycle of lung arlenecarcinoma cell A549, the effect of chorda serica chirurgicalis was medium, and the effect of slide wire was poor. Different length of each suture line had different effects on the proliferation and cell cycle of lung adenocarcinoma cell A549 （P 〈 0.05）, Conclusion： Three of suture line materials have different effects on the proliferation and cell cycle of lung adenocarcinoma cell A549, with dose-effect relationship.

Curcumin down-regulates PCNA,cyclin D1 and Bcl-X_L expression in human keratinocyte cell lines

Objective：To evaluate the effects of curcumin on regulating the proliferation,cell cycle distribution,apoptosis and relevant mechanisms in keratinocyte cell lines.Methods：The human immortalized human keratinocyte lines（HaCaT cells） were treated with different doses of curcumin.The effects of curcumin on cell viability were measured by MTT assay,and the cell cycle distribution and apoptosis determined by flow cytometry.The mRNA expression changes of proliferating cell nuclear antigen（PCNA）,cyclin D1 and Bcl-xL were from real-time PCR analysis and the protein levels were detected by Western blotting.Results：Data obtained in the study showed that curcumin could cause significantly inhibitory effect on proliferation in HaCaT cells in a time- and dose-dependent manner.Cell arrest at G1/S phase and significant apoptosis were observed after being treated with curcumin for 24 h.In association with these,the expression of PCNA,cyclin D1 and Bcl-xL were decreased both at mRNA and protein levels for the same treatment.Conclusion：Curcumin can inhibit proliferation,induce cell arrest at G1/S phase and cause apoptosis in HaCaT cells.The decreased expression of PCNA,cyclin D1 and Bcl-xL induced by curcumin contributes to the above effects in vitro.

MESANGIAL CELL PROLIFERATION INDUCED BY TNF-α IS DETERMINED BY LEVELS OF CYCLIN-KINASE INHIBITOR P27

Objective To investigate the role of cyclin-kinase inhibitor p27 on proliferation of mesangial cell(MC) induced by tumor necrosis factor α( TNF-α ). Methods The p27 protein of MC lysate was detected with western blotting analysis. The degree of MC proliferation was estimated through [^3H] thymidine incorporation. The effect of reducing p27 expression on MC proliferation was analysed with p27 antisense oligodeoxynucleotide (ODN). Results TNF-α(200000U/L) decreased p27 level to (0.6±0.1 ) from (1. 1±0.1 ) of MC lysate cultured in serum free DMEM for 24h ( P<0.01 ) and increased [^3H] thymidine incorporation to ( 2060±112 ) from (685±53) cpm/well( P<0.01 ). p27 antisense ODN transfection decreased p27 level of MC stimulated by TNF-α for 24h [(0.3±0.1 ) vs (0.6±0.1), P <0.01 ] and increased [^3H] thymidine incorporation [(2420±130) vs (2060±112) cpm/well, P <0.05]. Conclusion The decline of p27 protein maybe play an important role in MC proliferation induced by TNF-α.

Inhibitive effects of glucose and free fatty acids on proliferation of humanvascular endothelial cells in vitro

OBJECTIVES: To investigate the effects of glucose and free fatty acids (FFAs) on the proliferation and cell cycle of human vascular endothelial cells in vitro, and to examine whether the combined presence of elevated FFAs and glucose may cross-amplify their individual injurious effects. METHODS: Cultured human vascular endothelial cells (ECV304) were incubated with various concentrations of glucose and/or FFAs (palmitate and/or oleate) for 24 - 96 h. Morphologic alterations were observed using a phase contrast microscope and an electron microscope. Inhibition of proliferation was measured by a colorimetric 3-[4, 5-dimethyl thiazol-2-yl]-2, 5-diphenyltetrazolium bromide (MTT) assay. Cell viability was determined using trypan blue exclusion. Distribution of cells along phases of the cell cycle was analyzed by flow cytometry. RESULTS: Glucose 15 or 30 mmol/L, palmitate (PA) 0.25 or 0.5 mmol/L, and oleate (OA) 0.5 mmol/L inhibited proliferation and accelerated death of endothelial cells in a dose-and-time-dependent manner. After treatment with elevated glucose and/or FFAs, the G(0)/G(1) phase cells increased, whereas S phase cells decreased, suggesting that high glucose and/or FFAs mainly arrested endothelial cells at G(0)/G(1) phase. The inhibitive rates of proliferation and population of dead cells in endothelial cells incubated with glucose plus FFAs (glucose 30 mmol/L + PA 0.25 mmol/L, glucose 30 mmol/L + OA 0.5 mmol/L, glucose 30 mmol/L + PA 0.25 mmol/L + OA 0.5 mmol/L) increased more markedly than those treated with high glucose or FFAs (PA and/or OA) alone. CONCLUSION: Both high ambient glucose and FFAs can inhibit proliferation and accelerate death of endothelial cells in vitro. These changes were cross-amplified in the combined presence of high levels of glucose and FFAs.

Cell cycle analysis by cyclin E+A/DNA multiparameter flow cytometry in exponential growth MOLT-4 cells

Objective To establish a new method for analyzing the cell cycle in tumor which is a kind of cell cycle disease.Methods Mixtures of cyclin E and cyclin A antibodies were incubated with fixed MOLT-4 cells, and measured by flow cytometry.Results We developed a cyclin E+A/DNA flow cytometry analysis method, which may distinguish G0, early G1, late G1, S, G2 and M phase cells, rather than three phases in the DNA content histogram.Conclusion Cyclin E+A/DNA multiparameter flow cytometry can simultaneously differentiate in the same sample six cell groups: G0, early G1, late G1, S, G2 and M phase cells. It performed better than any other cell cycle analysis methods that we have used and has a definite cell biology foundation.

Inhibitive effects of glucose and free fatty acids on proliferation of human vascular endothelial cells in vitro

s To investigate the effects of glucose and free fatty acids (FFAs) on the proliferation and cell cycle of human vascular endothelial cells in vitro , and to examine whether the combined presence of elevated FFAs and glucose may cross amplify their individual injurious effects Methods Cultured human vascular endothelial cells (ECV304) were incubated with various concentrations of glucose and/or FFAs (palmitate and/or oleate) for 24-96 h Morphologic alterations were observed using a phase contrast microscope and an electron microscope Inhibition of proliferation was measured by a colorimetric 3 [4, 5 dimethyl thiazol 2 yl] 2, 5 diphenyltetrazolium bromide (MTT) assay Cell viability was determined using trypan blue exclusion Distribution of cells along phases of the cell cycle was analyzed by flow cytometry Results Glucose 15 or 30 mmol/L, palmitate (PA) 0 25 or 0 5 mmol/L, and oleate (OA) 0 5 mmol/L inhibited proliferation and accelerated death of endothelial cells in a dose and time dependent manner After treatment with elevated glucose and/or FFAs, the G 0/G 1 phase cells increased, whereas S phase cells decreased, suggesting that high glucose and/or FFAs mainly arrested endothelial cells at G 0/G 1 phase The inhibitive rates of proliferation and population of dead cells in endothelial cells incubated with glucose plus FFAs (glucose 30 mmol/L+PA 0 25 mmol/L, glucose 30 mmol/L+OA 0 5 mmol/L, glucose 30 mmol/L+PA 0 25 mmol/L+OA 0 5 mmol/L) increased more markedly than those treated with high glucose or FFAs (PA and/or OA) alone Conclusion Both high ambient glucose and FFAs can inhibit proliferation and accelerate death of endothelial cells in vitro These changes were cross amplified in the combined presence of high levels of glucose and FFAs