[Response of vegetation productivity to drought in the Qinling-Daba Mountains, China from 2001 to 2020]. / 2001­2020年秦巴山区植被生产力对干旱的响应.

To quantitatively evaluate the effects of drought on vegetation productivity in the Qinling-Daba Mountains, we analyzed the temporal and spatial characteristics of gross primary productivity (GPP) and drought, identified the fluctuation of negative GPP extremes under different vegetation types, and quantified the drought vulnerability and drought risk of GPP from 2001 to 2020 with MODIS GPP products and standardized precipitation evapotranspiration index (SPEI). The results showed that the annual GPP from 2001 to 2020 had an increasing trend in 98.0% of areas in the Qinling-Daba Mountains. The GPP of all vegetation types except wetlands increased significantly. SPEI decreased in 23.8% of area in the Qinling-Daba Mountains from 2001 to 2020. The number of negative GPP extremes had no significant trend, but abnormal GPP fluctuations had intensified, especially in the cultivated land. After 2011, the proportion of concurrent negative GPP extreme and drought had decreased for all vegetation types, but the spatial and temporal range of drought in these negative GPP extremes showed an expanding trend. Compared with the pattern during 2001-2010, the proportion of area with positive drought vulnerability and drought risk increased by 104.1% and 6.7% after 2011, indicating that the area with drought-induced GPP decline had expanded. Among all the vegetation types, drought caused the largest decrease of GPP in wetlands. The results revealed that drought led to an aggravation of GPP fluctuations and increased frequency of GPP extremes in the Qinling-Daba Mountains from 2001 to 2020, which resulted in GPP decline with different magnitudes in most vegetation types.

[Research progress on the cascade effect of ecosystem service.] / ç”Ÿæ€ç³»ç»ŸæœåŠ¡çº§è”æ•ˆåº”ç ”ç©¶è¿›å±•.

The ecosystem services cascade (ESC), which connects the components of ecosystem services with social value and builds a bridge between natural science and social science, can help decision-makers better integrate the concept of ecosystem services into decision-making. We reviewed the concept and the research progress of ESC. From the perspective of theory, the theoretical research of ESC mainly focused on how to accurately define each component and the causal relationship among different components, improve the practicability and applicability of ESC model, and how to effectively connect stakeholders and ecosystem service structure. From the perspective of application, ESC played an important role in ecosystem services mapping, ecosystem services assessment, and policy making. There were still great uncertainties in index selection and mutual feedback mechanism. Future research should be strengthened from the following aspects: to pay more attention to the structure process and classification standard of ecosystem services, to make up the lack of ESC of the feedback mechanism through multi-model fusion and regional survey, and to provide scientific guidance for human-earth coupling and sustainable development combined with regional characteristics .

Cancer risk assessment in modern radiotherapy workflow with medical big data.

Modern radiotherapy (RT) is being enriched by big digital data and intensive technology. Multimodality image registration, intelligence-guided planning, real-time tracking, image-guided RT (IGRT), and automatic follow-up surveys are the products of the digital era. Enormous digital data are created in the process of treatment, including benefits and risks. Generally, decision making in RT tries to balance these two aspects, which is based on the archival and retrieving of data from various platforms. However, modern risk-based analysis shows that many errors that occur in radiation oncology are due to failures in workflow. These errors can lead to imbalance between benefits and risks. In addition, the exact mechanism and dose-response relationship for radiation-induced malignancy are not well understood. The cancer risk in modern RT workflow continues to be a problem. Therefore, in this review, we develop risk assessments based on our current knowledge of IGRT and provide strategies for cancer risk reduction. Artificial intelligence (AI) such as machine learning is also discussed because big data are transforming RT via AI.

MiR-31 is a potential biomarker for diagnosis of head and neck squamous cell carcinoma.

MicroRNAs (miRNAs) play important roles in the development of head and neck squamous cell carcinoma (HNSCC). However, their potential clinical value as biomarkers remains poorly known. The aim of this study was to assess the association between tissue/serum miR-31 expression levels and prognosis of HNSCC. In this clinical study, tumor samples were obtained from 118 patients with HNSCC and 48 patients with oral epithelial dysplasia, and blood samples were collected from all the HNSCC cases and 60 normal controls. The expression levels of tissue/serum miR-31 were measured by real-time PCR. Chi-square test was used to evaluate the correlation between tissue/serum miR-31 and clinical parameters of HNSCC. Survival curves were constructed using the Kaplan-Meier method and log-rank test. Multivariate Cox regression analyses were used to estimate independent predictors of survival for HNSCC. Our findings showed that tissue miR-31 levels in HNSCC tumor specimens exhibited higher than that in oral epithelial dysplasia samples and normal tissues. Oral epithelial dysplasia with higher expression of miR-31 was more prone to progress into HNSCC. Likewise, serum miR-31 expression in HNSCC patients was markedly increased in compared to normal controls. Moreover, serum miR-31 performed well to distinguish HNSCC subjects from controls. In addition, increased tissue/serum miR-31 expression was positively correlated with poor clinical variables and dismal prognosis. Finally, tissue miR-31 was confirmed to be an independent prognostic factor for HNSCC. Taken together, miR-31 had strong potential as a promising biomarker in HNSCC detection.

A parameterized model for mean urinary inflow rate and its preliminary application in radiotherapy for cervical cancer.

Forty-nine patients with stage IIb cervical cancer were included to investigate the changes in bladder volume in response to different approaches to maintaining consistent bladder filling. The impacts of age (P age), water consumption (P wat ), and body mass index (BMI, P bmi ) on the mean urinary inflow rate (v tot ) were analysed. The bladder volume (BV) increased linearly over time. A large variation in v tot among individuals was observed, ranging from 0.19 to 5.13 ml/min. The v tot was correlated with P age (R = -0.53, p = 0.01) and P wat (R = 0.84, p = 0.00), and no correlation between v tot and P bmi was found (p > 0.05). Therefore, v tot could be parameterized using two methods: multivariable linear regression and iterative fitting. There was no statistically significant difference between the two methods. The model accuracy was successfully assessed with several validation tests for patients with good compliance (79.2% of all patients), and the proportion of radiotherapy (RT) fractions with zero wait time (one ultrasound (US) scan) increased from 6.5% to 41.2%. The optimal US scanning number and RT time could be provided using this model. This adaptive RT approach could reduce patient discomfort caused by holding onto urine and reduce technician labour as well as cost.

[Effect of different doses of radiation on human salivary gland adenoid cystic carcinoma cells].

PURPOSE: To explore the effect of different doses of radiation on human salivary gland adenoid cystic carcinoma cells (SACC-83, SACC-LM). METHODS: Different doses of radiation (0, 2, 4, 6, 8, 10 Gy) were applied to SACC-83, SACC-LM cells and the cells were continued to culture for 48 h. CCK-8 test, flow cytometry(FCM) and cell scratch experiment were used to observe cell proliferation, apoptosis and cell migration. SPSS19.0 software package was used for data analysis. RESULTS: The effect of radiation on SACC-LM cells survival rate, cell apoptosis, heteroploid and cell migration ability were significantly greater than that on SACC-83 cells (P<0.05). In SACC-83 cells, compared with other doses of radiation, 6 Gy of irradiation was the most sensitive on cell survival rate, cell apoptosis, heteroploid and cell migration ability. CONCLUSIONS: Radiation sensitivity of SACC-LM was greater than that of SACC-83 cells. With 6 Gy of radiation, changes of biology in SACC-83 cells most significant than other doses of radiation.

Correlation study of Bcl-2, B7-H1, EGFR, VEGF and colorectal cancer.

OBJECTIVE: To analyze the expressions of Bcl-2, B7-H1, EGFR and VEGF in colorectal cancer for the further investigation of their correlations with the clinical pathological features of colorectal cancer. METHOD: Fresh colorectal cancer tissues and the expressions of Bcl-2, B7-H1, VEGF and EGFR in paraneoplastic normal mucosal tissues of 57 cases were tested by immunohistochemisty method, and the results were analyzed by SPSS10.0. RESULTS: 1. Compared with paraneoplastic normal tissues, the expressions of Bcl-2 and B7-H1 in colorectal cancer tissues increased significantly with significant difference (P<0.05), while the expression of EGFR and VEGF in colorectal cancer tissues showed no significant difference with those in paraneoplastic normal tissue (P>0.05); 2. The correlation with clinical pathological features: there was significant difference of expression rates of EGFR between different genders (P<0.05); the expressions of BCL-2 and B7-H1 in colorectal cancer of the high- and medium- differentiated groups were significantly higher than those of the low-differentiated group, and the difference was significant (P<0.01); compared with the colorectal cancer patients without lymph node metastasis (Dukes stage A+B), the expression of B7-H1 in patients with lymph node metastasis (Dukes stage C+D) was significantly higher (P<0.05); 3. Within the high- and medium- differentiated colorectal cancer tissues, Bcl-2 expression rate in B7-H1 negative group was higher than the positive group with significant difference (P<0.01). CONCLUSIONS: In colorectal carcinoma, Bcl-2, B7-H1, EGFR and VEGF were all expressed, independent from age and depth of invasion. However, the expression level of Bcl-2 and B7-H1 correlated with tissue differentiation, and the latter also had correlation with tumor staging. Meanwhile, the short-term follow-up showed that high expression of Bcl-2/B7-H1 existed in death cases. Therefore, the expression detection of Bcl-2, B7-H1 might provide a clear understanding of the biological behavior of colorectal cancer, and was important for the diagnosis, treatment and prognosis judgment of colorectal cancer.

HMGA2 Expression in Renal Carcinoma and its Clinical Significance.

BACKGROUND: The objective of this study is to detect HMGA2 expression in renal carcinoma to explore its relationship with clinicopathology and its significance in prognosis. METHODS: Expressions of HMGA2 mRNA and protein were detected in 50 renal carcinoma specimens, 50 corresponding adjacent normal kidney tissue samples and 40 renal benign tumour specimens via reverse transcription polymerase chain reaction and immunohistochemical assay. Expression analysis was performed along with clinical data analysis. RESULTS: The relative expression levels of HMGA2 mRNA in renal carcinoma, renal benign tumour tissues and adjacent normal renal tissues were 0.84±0.23, 0.19±0.06 and 0.08±0.04, respectively. HMGA2 protein positive rates were 68.0%, 7.5% and 2.0%, with a significant difference (P<0.05). HMGA2 expression was not significantly correlated with gender, age, tumour size and histological type (P>0.05), but was significantly correlated with TNM stages and lymph node metastasis (P<0.05). CONCLUSIONS: The expressions of HMGA2 gene and protein in renal carcinoma were closely correlated with tumour formation, progression and metastasis. HMGA2 may become a powerful new pathological marker and prognostic factor for renal carcinoma.

Dosimetric evaluation of volumetric-modulated arc therapy (RapidArc) for primary leiomyosarcoma in the spine.

This study aims to investigate the suitability of volumetric-modulated arc therapy (VMAT) with RapidArc for primary leiomyosarcoma (LMS) in the spine, and present a new method to improve the target coverage and organs at risk (OAR) sparing. Five patients with LMS were retrospectively reviewed. The intensity-modulated radiotherapy (IMRT) with five coplanar beams (5b-IMRT) or seven coplanar beams (7b-IMRT), and VMAT using four quasi-quarter coplanar arcs (4q-VMAT) or two full coplanar arcs (2f-VMAT) were generated. Planning target volume (PTV) dose coverage, OAR dose sparing, conformity index (CI), and homogeneity index (HI) were evaluated. A hollow-cylinder model (HCM) was also used for feasible optimal beam arrangements. The mean doses to PTV were 95.2% ± 1.0%, 93.0% ± 1.0%, 97.9% ± 1.0% and 96.2% ± 1.5% for 4q-VMAT, 2f-VMAT, 5b-IMRT and 7b-IMRT respectively, while the mean maximum doses to spinal cord (SC) were 43.7 ± 0.9 Gy, 42.0 ± 0.8 Gy, 41.4 ± 1.2 Gy and 40.6 ± 1.4 Gy. Compared to 5b-IMRT, the mean doses delivered to kidneys decreased by about 35.1% (8.5 Gy), 2.5% (0.6 Gy) and 35.5% (8.6 Gy) for 4q-VMAT, 2f-VMAT, and 7b-IMRT, respectively. The CI proposed by Baltas et al. was twice as good with IMRT than with 4q-VMAT, and the numbers of monitor units were increased five- and threefold with 7b-IMRT and with 5b-IMRT compared to VMAT. The unexpected results we presented here show that VMAT technique can't achieve highly conformal treatment plans while maintaining SC sparing for LMS in the spine. An approach is proposed based on a hollow-cylinder model, but it is difficult to apply to clinical practice. In this case, VMAT is not superior to IMRT except for significant reduction in delivery time.

Prevalence of and risk factors for aspirin resistance in elderly patients with coronary artery disease.

OBJECTIVE: To assess the prevalence of and related risk factors for aspirin resistance in elderly patients with coronary artery disease (CAD). METHODS: Two hundred and forty-six elderly patients (75.9 ± 7.4 years) with CAD who received daily aspirin therapy (≥ 75 mg) over one month were recruited. The effect of aspirin was assessed using light transmission aggregometry (LTA) and thrombelastography platelet mapping assay (TEG). Aspirin resistance was defined as ≥ 20% arachidonic acid (AA)-induced aggregation and ≥ 70% adenosine diphosphate (ADP)-induced aggregation in the LTA assay. An aspirin semi-responder was defined as meeting one (but not both) of the criteria described above. Based on the results of TEG, aspirin resistance was defined as ≥ 50% aggregation induced by AA. RESULTS: As determined by LTA, 23 (9.3%) of the elderly CAD patients were resistant to aspirin therapy; 91 (37.0%) were semi-responders. As determined by TEG, 61 patients (24.8%) were aspirin resistant. Of the 61 patients who were aspirin resistant by TEG, 19 were aspirin resistant according to LTA results. Twenty-four of 91 semi-responders by LTA were aspirin resistant by TEG. Multivariate logistic regression analysis revealed that elevated fasting serum glucose level (Odds ratio: 1.517; 95% CI: 1.176-1.957; P = 0.001) was a significant risk factor for aspirin resistance as determined by TEG. CONCLUSIONS: A significant number of elderly patients with CAD are resistant to aspirin therapy. Fasting blood glucose level is closely associated with aspirin resistance in elderly CAD patients.

[Spatiotemporal variation patterns of potential evapotranspiration in five provinces of Northwest China in 1960-2011].

By using Penman-Monteith model and Hurst index model, this paper analyzed the spatiotemporal variation patterns of potential evapotranspiration (ET0) in the five provinces of Northwest China in 1960-2011. In the meantime, the dominant factors driving the variations of the ET0 were quantitatively analyzed by using sensitivity analysis method. In 1960-2011, the ET0 in the five provinces presented an overall decreasing trend, with a drop rate of -0.72 mm x a(-1), but the ET0 increased gradually after 1993. An obvious spatial difference was shown in the annual average ET0. The average ET0 in the five provinces was 1158 mm (675-2282 mm), wit the maximum (2282 mm) in Qijiaojing of Xinjiang and the low values (>800 mm) in Qinba Mountains in south Shaanxi. Except in spring, the ET0 in other seasons showed a decreasing trend. In the analysis of future trend, the ET0 in most areas (81.4%) of Northwest China would present a trend from decrease to increase. Therefore, under the background of global warming, the warm and wet degree in Northwest China would be somewhat weakened, but the ET0 in the middle part of Xinjiang would be decreased continuously. Wind speed was the main factor affecting the ET0 in Northwest China at both annual and monthly scales, but the affecting extent of wind speed differed with seasons and areas. The spatial extent affected by the wind speed in winter expanded across the entire five provinces of Northwest China, while the spatial extent affected by the wind speed in summer included the entire Xinjiang and the northwest of Gansu and Qinghai.

Cardiovascular and cerebrovascular outcomes in elderly hypertensive patients treated with either ARB or ACEI.

BACKGROUND: Although angiotensin converting enzyme inhibitors (ACEI) and angiotensin receptor blockers (ARB) are equally important in the treatment of hypertension, there is less evidence whether they have equal cardiovascular and cerebrovascular protective effects, especially in elder hypertensive patients. This study aims to clarify this unresolved issue. METHODS: This cross-sectional study included clinical data on 933 aged male patients with hypertension who received either an ARB or ACEI for more than two months between January 2007 and May 2011. The primary outcome was the composite of cardiovascular death, non-fatal myocardial infarction, and non-fatal stroke. The secondary endpoints were unstable angina, new atrial fibrillation, and transient ischemic attack. RESULTS: The median follow-up time was 24 months. Age, drug types, cerebral infarction history, renal dysfunction history were the independent predictors of the primary endpoint. The risk of an occurrence of a primary endpoint event was higher in the ARB group than the ACEI group [P = 0.037, hazard ratios (HR): 2.124, 95% confidence interval (95% CI): 1.048-4.306]. The Kaplan-Meier method also suggests that the rate of primary endpoint occurrence was higher in the ARB group than the ACEI group (P = 0.04). In regard to the secondary endpoints, there were no significant differences between the two treatment arms (P = 0.137, HR: 1.454, 95% CI: 0.888-2.380). Patient age and coronary heart disease history were independent predictors of the secondary endpoint. CONCLUSION: ACEI were more effective than ARB in reducing cardiovascular and cerebrovascular morbidity and mortality in aged patients with hypertension.

The molecular mechanism of the anticancer effect of atorvastatin: DNA microarray and bioinformatic analyses.

The aim of this study was to identify the molecular mechanisms and biological pathways associated with the anticancer effects of atorvastatin. For this purpose, we conducted cell-based microarray and bioinformatic analyses to determine the effect of atorvastatin exposure on endothelial cell response. The results of bioinformatic analysis performed using the Connectivity Map (cMap) to examine the atorvastatin-induced changes in gene expression in the human umbilical vein endothelial cell line, EA.hy926, indicated that treatment with 10 µM of atorvastatin for 24 h upregulated the expression of 295 genes and downregulated the expression of 354 genes by 2-fold compared to the control treatment. The gene set enrichment analysis (GSEA), the Database for Annotation, Visualization and Integrated Discovery (DAVID) pathway analysis, and Gene Ontology (GO) analysis of differentially expressed genes revealed that Kruppel-like factors (KLFs) and cell cycle-related genes were the genes most significantly affected by atorvastatin treatment. The upregulation of KLFs and the downregulation of the cell cycle-related genes, including cyclin (CCN)A2, CCNE2, CCNB1 and CCNB2, were validated by real-time polymerase chain reaction (RT-PCR). A comparison of the gene expression profile of atorvastatin-treated cells with that of the control cells and with that of 6,100 compounds in the cMap database revealed that the profile of atorvastatin-treated cells was highly similar to that of histone deacetylase (HDAC) inhibitor-treated cells. Therefore, these results suggest that atorvastatin acts as an HDAC, a G1/S (start) and a G2/M (mitosis) cell cycle inhibitor. These findings provide evidence of the feasibility of the use of atorvastatin as an anticancer drug.

[Impact of clopidogrel carboxylic metabolite SR26334 on gene expression profile of human umbilical vein endothelial cell line].

This study was purposed to characterize the effect of carboxylic acid metabolite (SR26334) of clopidogrel bisulfate deprived of antiplatelet efficacy on the spectrum of gene expression in the cultured human umbilical vein endothelial cell (HUVEC) line (EA.hy926), and to explore the potential molecule mechanism of SR26334 impact on HUVEC. By using a Affymetrix HU133 plus 2.0 oligonucleotide microarray, the alteration of gene expression spectrum induced by SR26334 in HUVEC was detected, the real-time PCR was used to confirm the results of selected differentially expressing genes. The results indicated that total 235 including 176 up-regulated and 59 down-regulated genes were obtained with change more than 1.5-fold after SR26334 (10 µmol/L) acted on HUVEC for 48 h. SR26334 affected the expression levels of genes involved regulation of transcription, transcription, positive regulation of transcription from RNA polymerase II promoter, cell cycle, cell division, protein amino acid dephosphorylation in HUVEC. It is concluded that carboxylic acid metabolite SR26334 of clopidogrel bisulfate modulates function of endothelial cells through different pathway at gene level.

Protective effects of atorvastatin against oxidized LDL-induced downregulation of KLF expression in EA.hy926 cells.

Krüppel-like transcription factors (KLFs) play a key role in both vascular development and pathophysiological processes, but little is known about the relationship between KLFs and oxidized low-density lipoprotein (ox-LDL). We investigated the effects of ox-LDL on KLF expression. Furthermore, since atorvastatin is commonly used to treat high cholesterol, we also examined the role of this drug in the regulation of KLF expression. The human umbilical vein endothelial cell line EA.hy926 was treated with atorvastatin and ox-LDL alone or in combination, and KLF expression was examined by DNA microarray, semi-quantitative real-time PCR, western blot and immunofluorescence analyses. Atorvastatin upregulated KLF expression in EA.hy926 cells in both the quiescent and ox-LDL-induced inflammatory states, suggesting that KLFs were novel participants in the vascular endothelial dysfunction response to ox-LDL. Our study demonstrated that atorvastatin increased both the mRNA and protein levels of KLF in quiescent EA.hy926 cells. Moreover, atorvastatin counteracted the ox-LDL-induced downregulation of KLF expression.

[Comparison on the effects of clopidogrel, statins combination in treating coronary artery disease among the elderly patients: a retrospective cohort study].

OBJECTIVE: To compare the effects of clopidogrel with or without combined with CYP3A4-metabolized statin in treating coronary artery disease (CAD) among the elderly patients. METHODS: The study cohort was defined as all patients were over 60 years of age and hospitalized for CAD who were prescribed clopidogrel between January 2000 and February 2011. A total of 1021 patients were enrolled, with 178 of them prescribed clopidogrel and 843 patients were administrated clopidogrel combined with statins (CYP3A4-metabolized statins 636 and non CYP3A4-metabolized statins 207). The primary endpoint was all cause of death and the second endpoint were non-fatal myocardial infarction (MI), but hospitalized for unstable angina, stroke, transient ischemic attack, or repeated revascularization (PCI or coronary artery bypass graft). RESULTS: Among the clopidogrel group and the clopidogrel plus statins group, the incidence density of death was 6.86/1000 and 3.18/1000 respectively, with crude RR as 2.15 (95%CI: 1.39-3.33) and statistically significant (χ2=3.53, P<0.01). The incidence density of composite thromboembolic events did not show statistical significance (P>0.05). The two groups were 1:1 matched, after propensity score matching, clopidogrel coadministrated with statins group showed significant decrease in all cause of death, with RR as 0.42 (95%CI: 0.19-0.93), χ2=7.23, P<0.01. No significant difference was observed in deaths or composite thromboembolic events between statins via different cytochrome P450 pathways. CONCLUSION: Clopidogrel with statin could reduce the mortality of elderly CAD patients compared with clopidogrel without statin. The result did not show statistical significance between CYP3A4-metabolized statins or non CYP3A4-metabolized statins regarding the mortality or composite endpoint events.

[Impact of clopidogrel on gene profile of human umbilical vein endothelial cell line and bioinformatics analysis].

This study was purposed to investigate the effect of clopidogrel on gene expression profile of cultured human umbilical vein endothelial cell (HUVEC) line (EA.hy926), and explore its potential molecule mechanism. A Affymetrix U133 plus 2.0 oligonucleotide microarray was applied to detect the alteration of gene expression profile induced by clopidogrel in HUVEC. Real time RT-PCR was used to verify the result of selected differentially expressing genes. The results showed that total 508 genes (including 139 up-regulated and 369 down-regulated genes) were obtained with differential expression more than 1.5-fold after clopidogrel (10 µmol/L) acted on HUVEC for 48 h. Clopidogrel affected the expression levels of genes involved protein binding, transcription factor activity, zinc ion binding, regulation of DNA-dependent transcription, transcription, RNA splicing and so on. It is concluded that the clopidogrel modulate function of endothelial cells by regulating sets of genes through different pathway.

Angiogenesis related gene expression profiles of EA.hy926 cells induced by irbesartan: a possible novel therapeutic approach.

BACKGROUND: Angiogenesis occurs commonly in various physiological and pathological processes. Improving blood supply through promoting angiogenesis is a novel approach for treating ischemic diseases. Angiotensin II type 1 receptor blockers (ARBs) dominate the management of hypertension, but evidence of their role in angiogenesis is contradictory. Here we explored the angiogenic effects of ARBs through characterizing gene expression of the human umbilical vein endothelial cell line EA.hy926 exposed to irbesartan. METHODS: The human umbilical vein endothelial cell line EA.hy926 was grown for 72 hours after treatment with different concentrations of irbesartan. The cell proliferative capacity was assessed by CCK8 assay at 24, 48 and 72 hours. Gene expression levels in EA.hy926 cells responding to irbesartan were measured under optimal proliferation conditions by microarray analysis using Affymetrix U133 plus 2.0. The differential expression of genes involved in angiogenesis was identified through cluster analysis of the resulting microarray data. Quantitative RT-PCR and Western blotting analyses were used to validate differential gene expression related to the angiogenesis process. RESULTS: In the 10(-4), 10(-5), 10(-6) mol/L treatment groups, cell proliferation studies revealed significantly increased proliferation in EA.hy926 cells after 24 hours of irbesartan treatment. However, after 48 and 72 hours of treatment with different concentrations of irbesartan, there was no significant difference in cell proliferation observed in any treatment group. We selected the group stimulated with irbersartan at a concentration of 10(-6) mol/L for microarray experiments. Statistical analysis of the microarray data resulted in the identification of 56 gene transcripts whose expression patterns were significantly correlated, negatively or positively, with irbesartan treatment. Cluster analysis showed that these genes were involved in angiogenesis, extracellular stimulus, binding reactions and skeletal system morphogenesis. Of these 56 genes we identified seven genes (VEGF, KDR, PTGS2, PLXND1, ROBO4, LMO2, and COL5A1) involved in the angiogenesis process. qRT-PCR analysis of these genes confirmed the microarray results. Protein expression of three VEGF pathway genes (VEGF, KDR, and PTGS2) was further confirmed by Western blotting. CONCLUSIONS: Our study showed that irbesartan may induce angiogenic effects in vascular endothelial cells. It suggested that the mechanism of angiogenic effects of ARBs might be attributed to the signaling cascade from angiotensin receptors in the VEGF pathway. It also provided evidence indicating that ARBs could be used as a novel therapeutic approach to treat chronic ischemic heart disease as well as anti-hypertensive agents.

[Effect of irbesartan on the proliferation, apoptosis and VEGF mRNA expression of human umbilical vein cell line ea. hy926 in vitro].

OBJECTIVE: To evaluate the effect of irbesartan on the proliferation, apoptosis, and VEGF mRNA expression of human umbilical vein cell line EA.hy926 in vitro. METHODS: The human umbilical vein cell line EA.hyY926 were treated with various concentrations of irbesartan for 24 h. The cell proliferation after the treatment was detected by CCK8 assay, flow cytometry and FITC Annexin V/PI kit were used to detect changes in the cell apoptosis. RT-PCR was used to evaluate the expression of VEGF mRNA. RESULTS: There were no changes in cell shape with various concentration of irbesartan. CCK-8 assay showed a greater rate of the cell proliferation in irbesartan group than that in control group with a dose-independent manner after 24 h treatment. After incubation with irbesartan, cell proliferation rate was significant (P < 0.05). FCM analysis showed no significantly changes in the cell apoptosis. Irbesartan increased the proliferation of EA.hy926 cells. At concentration of 1 x 10(-4), 1 x 10(-5), 1 x 10(-6) mol/L, VEGF mRNA expression enhanced either (P < 0.05). CONCLUSION: Irbesartan could promote the proliferation and up-regulated VEGFmRNA expression in EA.hy926 cell line. This result suggested that in addition to antihypertensive effect, angiotensin receptor antagonist might be a novel therapeutic approach to chronic ischemic heart disease as heart failure.