Analysis of gene expression profile of multidrug resistant MCF/DOX cell line after benflumetol derivative LY980503 treatment

AIM:To investigate the effect of LY980503(a benflumetol derivative)on multidrug resistance of tumor cell line using DNA microarray.METHODS:Total RNA was extracted from multidrug resistant MCF/DOX cell line. cDNA microarray containing 320 cDNAs was used to detect the gene expression profile.RESULTS:9 down-regulated genes and 1 up-regulated gene were identified after multidrug resistant MCF/DOX cells were treated with LY980503.CONCLUSION:LY980503 can effectively reverse the resistance of MCF/DOX to DOX in vitro by adjusting the expression of multi-genes.     

Cortical gene expression pattern in rat focal cerebral ischemia

AIM: To investigate the genes differential expression in cortex during rat focal cerebral ischemia.METHODS: cDNA microarray chips containing numerous cDNAs were used to investigate the gene expression pattern between samples of focal cerebral ischemia and sham-control operation rats. RESULTS: Two hundred and eleven genes differentially expressed were screened out, among these genes, up-and down-regulated genes were 199 and 12, respectively. CONCLUSIONS: The analysis of gene expression pattern of focal cerebral ischemia based on cDNA microarray can realize high-throughput screening of the genes associated with the focal cerebral ischemia. The differential expression of genes may be related to the pathogenesis of focal cerebral ischemic diseases.     

DNA chip and its applications in medicine

The development of DNA chip has been strongly driven by modern approaches of life science and microelectronics. The broad of DNA chip applications include the detection of pathogens, the detection of mutations in genes involved in human diseases or affected during cancer progression, sequence analysis, the pattern of gene expression monitoring and pharmacy studies. This review explains the technology, its scope, and impact on medicine, as well as its cost and possible limitations.     

Role of estrogen on expression of TNF-α and MMP-9 in intracranial arterial vascular wall of spontaneous hypertensive rats

AIM: To study the effects of estrogen on the inflammatory response and vascular remodeling of intracranial artery in rats.METHODS: Thirty-two female spontaneous hypertensive rats (SHR) were randomized into 4 groups: spontaneous hypertensive group(sham-operated), ovariectomized group, ovariectomized+17 beta-estradial group and ovariectomized+vehicle group (8 rats in each group).On day 14, estradiol was detected by radioimmunoassay.The pathological changes were observed under light microscope.The protein expression of tumor necrosis factor alpha (TNF-α) and matrix metalloproteinase-9 (MMP-9) in vascular wall of Willis circle was detected by Western blotting.RESULTS: The estrogen level was lower in ovariectomized group than that in sham-operated group (P<0.01).The estrogen level was higher in ovariectomized rats treated with 17 beta-estradial than that in ovariectomized rats treated with vehicle (P<0.01).Advanced aneurysm was not found in all groups.Early aneurysmal change was not found in sham-operated group.Early aneurysmal changes in some rats were observed in ovariectomized group (2 rats), ovariectomized+vehicle group (3 rats) and ovariectomized+17 beta-estradial group (1 rat).The protein levels of TNF-α and MMP-9 in the vascular wall of Willis circle in sham-operated group were lower than that in ovariectomized group (P<0.01).Additionally, the protein levels of TNF-α and MMP-9 in the vascular wall of Willis circle of ovariectomized rats treated with 17 beta-estradial were lower than those of ovariectomized rats treated with the vehicle (P<0.01).CONCLUSION: Estrogen can influence the vascular remodeling of intracranial artery by inhibiting the inflammatory response and degradating MMP-9 in the vascular wall.     

Differential expressions of ameloblastoma related genes determined by microarray

AIM: This study aims to screen the differentially expressed genes related to the pathogenesis of ameloblastoma by cDNA microarray. METHODS: The total RNAs were isolated from ameloblastoma and tooth germ, respectively. The RNAs were purified by oligotex. Both the mRNAs from two kinds of tissues were reversely transcribed to cDNA with the incorporation of fluorescent-labelled dUTP to prepare the hybridization probes. The mixed probes were hybridized to cDNA microarray. Tumor- related genes were screened through the analysis of fluroescent intensity. RESULTS: 722 genes exhibited significant changes in expression levels in the ameloblastoma in comparison with tooth germs tissues. 240 genes were overexpressed more than doubled (92 genes were more than 3-fold), and 482 genes were underexpressed to below 0.5 of the control level. CONCLUSION: Microarray technique facilitates large scale and rapid identification of potential target genes of ameloblastoma.     

Regulation of estrogen on the expression of KLK6 mRNA and protein in human breast cancer cell line MCF-7

AIM:To investigate the effects of estrogen and tamoxifen on the expression of KLK6 mRNA and protein (hK6) in human breast cancer cell line MCF-7. METHODS:MCF-7 cells were incubated with 17-βE2 and tamoxifen at different concentrations for 72 hours, respectively. The expression levels of kallikrein 6 (KLK6) mRNA and protein were evaluated by fluorescence quantitative RT-PCR and flow cytometry, respectively. RESULTS:Compared with ethanol control, KLK6 mRNA expression levels were significantly decreased when 17-βE2 was added at concentrations of 10^-10 and 10^-8 mol/L (P<0.01). No statistical change was observed when 17-βE2 was at 10^-12 mol/L (P>0.05). Flow cytometry showed the same results. The average fluorescence intensity (AFI) that represents the level of hK6 was decreased after incubated with 17-βE2 (P<0.01). After incubation with tamoxifen, the levels of KLK6 mRNA and hK6 were increased (P<0.01). CONCLUSION:Estrogen down-regulates the expression levels of KLK6 mRNA and protein (hK6), while tamoxifen has an opposite effect.     

Effects of platelet-derived growth factor and angiotensinⅡ on the expression of cell cycle related genes in vascular smooth muscle cells

AIM: To investigate the different expressions of cell cycle related genes in hyperplastic and hypertrophic vascular smooth muscle cells caused by platelet-derived growth factor (PDGF-BB) and angiotensinⅡ(AngⅡ). METHODS: Rat aorta media smooth muscle cells were cultured. PDGF-BB and AngⅡ were added into serum-free medium at a concentration of 20 μg/L and 10^-6 mol/L , respectively. Vascular smooth muscle cells (VSMCs) were harvested after stimulated for 24 hours. The expression of cell cycle related genes was measured by DNA chips(Atlas cDNA Expression Arrays, Clontech Laboratories, Inc.). RESULTS: The expression of cyclin D3 mRNA ,cyclin G1 mRNA,p57 mRNA,p16 mRNA,E2F-3 mRNA and DP2 mRNA were higher in PDGF-BB than those in AngⅡstimulated VSMCs. p15 mRNA,p19 mRNA,E2F-1 mRNA, E2F-5mRNA,and N-myc mRNA were only detected in PDGF-BB stimulated group. But the expression of p53-associated protein mRNA were higher in AngⅡstimulation group. The expression of PCNA mRNA, c-myc binding protein mRNA,p53-dependent cell growth regulater mRNA,cyclinC mRNA, cyclinB1 mRNA, E2F-3mRNA were similar in the two groups. CONCLUSION: The procession of cell cycle relys on the coordination of many regulater molecules expressed in different phases. Our study preliminarily definite the genes that express during PDGF-stimulated VSMC's hyperplasia and Ang II-stimulated VSMC's hypertrophy.     

Expression of TGF-β1 and apoptosis in myocardium of diabetic rats

AIM: To study the pathophysiological mechanism of cardiomyopathy, the expression of TGF-β₁ and apoptosis in myocardium of diabetic rats were investigated. METHODS:The diabetes models were established by single intravenous injection of streptozotocin (50 mg/kg) in rats. By the method of immunochemistry, the expression of TGF-β₁ in the cardiomyocytes was detected as the index to evaluate the degree of fibrosis. The method of TUNEL was used to measure the cardiomyocyte apoptosis as the index to explore its importance in process of diabetic cardiomyopathy. RESULTS:① The weight of diabetic rats was apparently lower than that in the rats before the diabetic model was built (P<0.01), and the increase in weight in diabetic rats within three month was less than that in normal group. ② Compared with control group, the concentration of blood glucose was continually elevated during the experiment. ③ The expression of TGF-β₁ in the diabetic cardiac muscle was much more than that in normal group (P<0.01). ④ The apoptosis of myocardium measured by the method of TUNEL was apparent in the diabetic groups than that in normal one (P<0.01). However, no significance was detected in the different courses of diabetic groups. CONCLUSIONS:The apoptosis might play an important role in leading the diabetic cardiomyopathy to heart failure. The expression of TGF-β₁ in the myocardium of diabetic rats was more than that in normal and had an increasing trend in the procession of diabetic cardiomyopathy. TGF-β₁ might be a significant factor in diabetic myocardium fibrosis. Apoptosis might play an important role in the initial stage of diabetes, which promotes the diabetic cardiomyopathy to heart failure.     

Effect of NP9 on gene expression profile of NPC cell line CNE1

AIM: To identify the gene expression profiles of CNE1 cells stably transfected with NP9 expressing plasmid, and to explore the potential molecular function of NP9 gene.METHODS: CNE1 cells stably expressing NP9 protein and CNE1 cells transfected with empty vector were used as test and control. Differentially expressed genes were screened with high- throughout human genome array. Differential expression of 6 genes was analyzed with quantitative RT-PCR. RESULTS: Of all the 14 500 human genes in array, 266 genes were revealed differential expression between test and control , of which 82 genes (RA>1)were up-regulated in test and 184 genes (RA<1) were down-regulated. 34 genes and 75 genes were found distinctively up-regulation (RA>1.5) and down-regulation (RA<1.5),respectively.CONCLUSION: NP9 expression in CNE1 cells leads to changes of some genes involved in regulation of cell cycle, cell proliferation and differentiation, cell signal transduction, cell adhesion. Some new clues may be provided for further studying the potential function and molecular mechanism of NP9 gene.     

Effect of Sini decoction on GST expression in the ischemic myocardium

AIM:To detect the effect of Sini decoction on glutathione S-transferase (GST) mRNA expression in the ischemic myocardium. METHODS:Kunming mice were randomly divided into control group, ischemic group and Sini decoction group. Total RNA was extracted from the myocardium of mice in each group. The effect of Sini decoction on the expression of GST gene was detected by RT-PCR. RESULTS:The expression of GST mRNA in Sini decoction group was significantly up-regulated compared with the ischemic group and control group.CONCLUSION:Sini decoction can promote the expression of GST gene,which may be related to its protective effect on ischemic myocardium.     

全基因组基因表达分析技术及其在果树上的应用

基因表达分析对于揭示基因功能、了解基因间相互关系、阐明植物生长发育过程中的生理生化调控机制起着至关重要的作用。综述了mRNA差异显示、cDNA-AFLP、基因芯片、EST数据分析、基因表达系列分析(SAGE)等全基因组基因表达分析技术的原理特点及在果树上的应用情况,并介绍了利用全基因组基因表达分析技术开展果树研究的思路。     

Cytological characteristics and gene micro-array analysis of a mouse brain microvascular endothelial cell strain: bEnd.3

AIM: To study the cytological characteristics and gene expression of normal cultured bEnd.3, a mouse brain microvascular endothelial cell strain. METHODS: The morphology of bEnd.3 was studied by light and electronic microscopy, its molecular markers were observed by immunocytochemistry. Cell proliferation kinetics and apoptosis were analyzed by flow cytometry and MTT assay, PGE₂ level was measured by ELISA, and expression of the genes that closely related with vascular endothelial functions was studied by gene micro-array. RESULTS: bEnd.3 had morphological characteristics of microvascular endothelial cells (MVEC) growing in a cobblestone pattern, forming tube-like structure or capillary network and having microvilli. Furthermore, bEnd.3 showed positive staining for vW factor and CD34 and secreted high level of PGE₂ (644.55±30.24 ng/L). Gene micro-array analysis showed CD31, CD36, CD105 expression, and other genes closely related to microvascular endothelial functions also expressed at relatively high level. In addition, bEnd.3 responsed sensitively to mitogen such as basic fibroblast growth factor. CONCLUSION: bEnd.3 is a kind of MVEC, and it can be utilized to study the mechanisms of some diseases such as cancers and cardio- cerebral vascular diseases.     

Effects of atorvastatin on myocardium expression of peroxisome proliferator-activated receptors in spontaneously hypertensive rats

AIM: To investigate the effects of atorvastatin on myocardium peroxisome proliferator-activated receptors (PPARs) expression, regression of left ventricular hypertrophy, and the possible mechanisms in spontaneously hypertensive rats (SHR). METHODS: 16 nine-week-old male spontaneously hypertensive rats were randomly divided into two groups: SHR received atorvastatin at dose of 30 mg·kg-1·d-1 by oral gavage once daily for 8 weeks (SHR-A, n=8), and SHR received vehicle (0.9% saline) as controls (SHR, n=8). Age-matched Wistar-kyoto rats received vehicle for 8 weeks were served as normaltensive controls (WKY, n=8). Systolic blood pressure was measured at the beginning, 2, 4 and 8 weeks of the experiment. At the end of the experiment, plasma lipid levels were measured. Left ventricular hypertrophy was accessed by pathological analysis. The expressions of PPARα and PPARγ were investigated by the method of Western blotting. RESULTS: There was not much difference of systolic blood pressure and plasma lipid levels between SHR-A and SHR group (P>0.05). Compared with SHR group, left ventricular weight mass index decreased significantly in SHR-A group (P<0.01). The myocardium PPARα and PPARγ expression increased significantly (P<0.01). CONCLUSION: Atorvastatin regresses left ventricular hypertrophy and increases myocardium PPARα and PPARγ expression in spontaneously hypertensive rats, which is independent of its lipid-lowering activity.     

Effects of pyrrolidine dithiocaramate and Vit C on ICAM-1 and SOD gene expression in rats with acute pancreatitis

AIM:To investigate the effects of pyrrolidine dithiocaramate (PDTC) and vitamin C (Vit C) on the intercellular adhesion molecule 1 (ICAM-1) gene expression and the superoxide dismutase (Mn-SOD, Cu, Zn-SOD) gene expression in a rat model of acute pancreatitis (AP). METHODS:Rat AP model was induced by retrograde injection of 3% sodium taurocholate in the bilio-pancreatic duct. The AP rats were divided into three groups: the normal saline (NS) group, the PDTC group and the Vit C group. The three groups were separately administered NS, PDTC and Vit C at 10 min and 5 h after operation. Rat sham operation (SO) group was subjected to laparotomy only with no further treatment. The levels of ICAM expression, Mn-SOD and Cu, Zn-SOD expression in pancreas and liver were determined by RT-PCR at 1, 5 and 10 h after the induction of AP. RESULTS:Comparing with SO group, the NS group showed a higher expression of ICAM-1 and a lower expression of Mn-SOD both in pancreas and in liver, and a lower expression of Cu, Zn-SOD in pancreas. PDTC treatment reduced the ICAM-1 expression and increased the Mn-SOD and Cu, Zn-SOD expression to a certain degree comparing with NS group, especially at 5 h. Vit C treatment also increased the Mn-SOD and Cu, Zn-SOD expression. But no obvious suppressive effect on ICAM-1 expression was observed in Vit C group.CONCLUSIONS:PDTC and Vit C have the effects of enhancing Mn-SOD and Cu, Zn-SOD expression.PDT C has an effect of inhibiting ICAM-1 expression in the pancreas and liver of rats with AP, whereas Vit C dose not.The results suggest that one of the mechanisms of PDTC and Vit C treat ing AP not only anti-oxidate directly by themselves, but also enhance Mn-SOD and Cu, Zn-SOD expression, and that the anti-inflammatory ef ect of PDTC is involved in the suppression of ICAM-1 expression.