Prognostic significance of microRNA-20a-5p levels which promotes proliferation and invasion by targeting cyclin G2 in small cell lung cancer

MicroRNA-20a-5p (miR-20a-5p) has been shown to function as a tumor promoter factor in several cancers. However, its role in small cell lung cancer (SCLC) remains unclear. In this study, we have made an attempt to measure the tumor tissue levels of miR-20a-5p in patients with SCLC using quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR). The biological function of miR-20a-5p in SCLC cells was investigated in vitro and in vivo studies, including cell proliferation, migration assays and tumorigenicity in nude mice. Meanwhile?we conducted the luciferase reporter assay to verify the biological relationship between miR-20a-5p and CCNG2. The expression of miR-20a-5p was significantly upregulated in human SCLC compared to that in normal tissues. Kaplan-Meier analysis indicated that patients with high expression of miR-20a-5p are closely related with the shorter survival of SCLC. Further, multivariate analysis showed that miR-20a-5p was an independent prognostic factor. Increasing miR-20a-5p expression promotes the proliferation, migration and invasion of the NCI-H446 cells in vitro and in vivo. Dual-luciferase reporter gene assay demonstrated that miR-20a-5p directly targets CCNG2. These findings suggest that miR-20a-5p levels might be a novel diagnostic and prognostic marker of SCLC. Inhibiting miR-20a-5p could be a promising therapeutic strategy for SCLC.

The "target + activity" method for rapid discovery of active compounds targeting Hsp90 in pancreatic cancer cells from Physalis angulata L / 药学学报

The purpose of this study was to select the active compounds targeting Hsp90 protein in pancreatic cancer cells through a new dual "target + activity" rapid discovery technique. We combined an in vitro anti-cancer activity screening method with a dual-luciferase reporter gene and multi-chromatography separation technology, for rapid discovery of potential Hsp90 inhibitors from the Chinese herbal medicine Physalis angulata L. The anti-proliferation activity of those compounds was assessed in pancreatic cancer cell line BxPC-3 by MTT assays. The molecular mechanisms of Hsp90 inhibition were explored by Western blot and shRNA knockdown assays. As a result, two withanolides, withanolide E (WE) and 4β-hydroxywithanolide E (HWE), were identified from Physalis angulata L. The half maximal inhibitory concentration (IC50) of WE and HWE were 0.71±0.03 and 1.23±0.10 μmol·L-1 for the growth of BxPC-3 cells in 48 h. Luciferase reporter assay demonstrated that WE and HWE significantly induced heat shock element (HSE) activity in a dose- and time-dependent manner. The molecular mechanism study showed that after exposing to 5 μmol·L-1 WE or HWE for 48 h, the aggregation of Hsp90 dimer was upregulated to 6.5±1.3 and 11.8±2.0 fold, while the expression of Hsp90 client protein Akt was downregulated to 21.7%±2.8% and 9.8%±1.4% of the control group. Moreover, the Hsp90 inhibitory activity of WE or HWE was canceled by shRNA mediated Hsp90 knockdown. Overall, based on the dual "target + active" rapid discovery technique, two new Hsp90 inhibitors WE and HWE were found from Physalis angulata L. The Hsp90 inhibitory mechanism of WE and HWE may be mediated by induction of Hsp90 aggregate dimer and inhibition of Hsp90 client protein Akt expression.

MicroRNA-29a-3p regulates osteoblast differentiation and peri-implant osseointegration in a rat model of hyperlipidemia by modulating Frizzled 4 expression / 华西口腔医学杂志

OBJECTIVE@#This work aimed to study and identify the influence and target gene of microRNA-29a-3p (miR-29a-3p) in the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) in a high-fat environment in vitro and in vivo.@*METHODS@#1) In vitro: BMSCs were randomly allocated into two groups and were then induced to undergo osteogenic differentiation in a normal or high-fat environment. Next, a miR-29a-3p mimic/inhibitor was transfected into the two groups of cells. The mRNA expression levels of alkaline phosphatase (ALP), Runt related gene 2 (Runx2), and miR-29a-3p and the protein expression levels of ALP and Runx2 were detected before and after transfection through reverse transcription-quantitative real-time polymerase chain reaction (RT-qPCR) and Western blot analyses. Moreover, Frizzled (Fzd) 4 was predicted as the target gene of miR-29a-3p by using an online database (Target Scan, MiRNA.org). The interactive relationship between miR-29a-3p and Fzd4 was confirmed through dual-luciferase assays. 2) In vivo: Rats were randomly divided into two groups and fed with a standard or high-fat diet. Titanium implants were grown in rats. Then, the expression levels of miR-29a-3p, ALP, and Runx2 were detected in bone tissues surrounding implants. Moreover, hard tissue sections were subjected to methylene blue-acid magenta staining and observed under microscopy to study bone formation around implants. In addition, miR-29a-3p-overexpressing lentiviral vectors were transfected into rats, and the expression levels of ALP, Runx2, and miR-29a-3p in bone tissues surrounding implants were detected at 3 and 10 days after transfection.@*RESULTS@#The expression levels of ALP, Runx2, and miR-29a-3p and the osteogenic differentiation of BMSCs were suppressed in high-fat groups in vitro and in vivo.@*CONCLUSIONS@#MiR-29a-3p plays a positive role in the regulation of BMSCs in a high-fat environment. It can increase ALP and Runx2 expression levels in bone tissues surrounding implants in hyperlipidemia models. This result implies that miR-29a-3p can promote implant osseointergration in a rat model of hyperlipidemia.

Construction of luciferase reporter gene cell model and its application in screening rhein derivatives targeting RAC1 / 中国药理学通报

Aim To establish luciferase reporter gene expression cell models of CNEi-RACI-Luc2 based on the target of RAC1 promoter, and explore the application of screening anti-tumor active of rhein derivatives targeted regulating RAC1 at transcriptional level. Methods The lentiviral carrying luciferase reporter vector was designed and synthesized using RAC1 promoter se-quence, and CNE1 cells were infected with recombinant plasmid lentiviral to obtain cell lines that stably expressed firefly luciferase. Luciferase reporter assay was used to detect the luciferase luminescence value after stimulating with RAC1 activator PMA and inhibitor NSC23766 that targeted regulating the RAC1 promoter activities in cells, and RAC 1 expression was verified by Western blot. The effect of series of rhein derivatives on the lu-cifcrase activity of RAC1 promoter was observed, and RAC1 expression was determined by Western blot. Results The identification result of double enzyme digestion showed that a lentiviral expression vector carrying luciferase reporter vector rc-combined with RAC1 promoter was successfully constructed. Lcntivirus-infcctcd CNE1 cells were screened by puromycin, the CNE1-RAC1-Luc2 cells stably expressing firefly luciferase were obtained, and the Iransfection efficiency was over 90%. The RAC1 luciferase reporter assay system was sensitive to FMA and NSC23766 and consistent with the result of RAC1 protein expression by Western blot. The regulation of series of rhein derivatives to RAC1 luciferase activity of CNE1-RAC1-Luc2 cells was consistent with the results of Western blot. Conclusions The cell model of luciferase reporting system containing RAC1 promoter can be successfully constructed, which provides a practical platform for high throughput screening of RAC1-targeted drugs.

Regulatory effect of grainyhead-like 2 gene on proliferation of epithelial ovarian cancer cells by nuclear factor erythroid-2-related factor 2 transcription / 解剖学报

Objective: To study the effect of nuclear factor erythroid-2-related factor 2(Nrf2) and the downstream gene grainyhead-like 2(GRHL2) on epithelial ovarian cancer cell lines and the interaction of Nrf2 and GRHL2. Methods: We conducted ChlP-PCR assay to test the binding of Nrf2 with six candidate genes including GRHL2. Furthermore, we proved whether Nrf2 could bind with the GRHL2 promoter and transcriptionally activate the GRHL2 gene or not. Moreover, if the overexpression and knockdown of Nrf2 could increase and decrease the GRHL2 protein respectively. Results: We discovered that fallopian tube epithelial cells taken from epithelial ovarian cancer patients and ovarian cancer cell lines highly expressed the Nrf2 and GRHL2 at mRNA level. The overexpression and knockdown of Nrf2 could increase and decrease the cells activity, respectively. However, the knockdown of GRHL2 could inhibit the influence of Nrf2 overexpression. Conclusion: Nrf2 promotes the activity of epithelial ovarian cancer cells via modulating the GRHL2 gene transcriptionally.

Establishment of a suitable control reporter plasmid of a dual luciferase reporter gene system for hormone research in silkworm cell lines / 生物工程学报

The dual luciferase reporter gene system provides sensitive readout, while it relies on a constitutively-expressed control gene for readout normalization. However, most standard control reporter genes are not constitutively expressed under all conditions. Here, we report an effective method to construct a control reporter plasmid for the dual luciferase reporter gene system that would be suitable for hormone research in silkworm cell lines. First, we modified BmVgP78M, a stably-expressed constitutive promoter in silkworm cells by mutating its hormone-related element. Then, we constructed the pRL-VgP78M control reporter plasmid by replacing the SV40 promoter and chimeric intron sequences in pRL-SV40 with the BmVgP78M sequence. Finally, we confirmed that the pRL-VgP78M control reporter plasmid could be stably expressed in silkworm cell lines via cell transfection experiments, and it was unresponsive to the induction of ecdysone, juvenile hormone, or their transcription factors. We thus obtained a control reporter plasmid pRL-VgP78M that could be expressed stably and moderately in silkworm cells. It can be readily used as the control reporter plasmid of the dual luciferase reporter gene system for hormone research in silkworm cell lines. It will also provide a reference for construction of control reporter plasmids of dual luciferase reporter gene systems that are adaptable to cell lines isolated from other species.

Establishment and Application of High-throughput Screening Model for Active Ingredients of Traditional Chinese Medicine Based on CXCR4 Promoter / 中国中医药信息杂志

Objective To establish a cell model targeting the CXCR4 gene promoter to screen of drugs potentially promoting the stem cell homing, and to screen the monomers of traditional Chinese medicine. Methods The human CXCR4 gene promoter sequence (279 bp) was inserted into the luciferase reporter vector pGL4.17-Basic to construct the recombinant plasmid pGL4.17-CXCR4, which was co-transfected with the internal reference plasmid pRL-TK into 293 cells. After verifying transcriptional activity of CXCR4 promoter, single cell clones were cultured to obtain a stable transfectant cell line and used for screening of candidate Chinese herbal monomer (1 to 10). Finally, Western blot was used to verify the effect of the selected Chinese herbal monomer on the expression of CXCR4 in MSCs. Results The drug screening cell model was successfully established and the candidate monomer 6 was screened out because of the strongest effect on enhancing CXCR4 promoter activity. Western blot results verified that the candidate monomer 6 could promoted the expression of CXCR4 of MSCs. Conclusion The drug screening cell model established in this study was able to achieve high-throughput screening for potentially promoting the stem cell homing Chinese herbal monomer.

Effects of Saikosaponin-d on Transcriptional Activation of Estrogen Receptor in Rat Hepatic Stellate Cells / 广州中医药大学学报

Objective To observe the effect of saikosaponin-d on transcriptional activation of estrogen receptor in rat hepatic stellate cells(HSC-T6), and to explore its pharmacological mechanism. Methods The rat HSC-T6 were cultured in vitro for the study. After transient transfection of HSC-T6 with the ER-specific reporter gene ERE-tk-Luc by liposome, the effect of saikosaponin-d and estradiol on luciferase activity was observed by Dual-Luciferase Reporter Assay System under the conditions of various drug concentrations, various treatment time and addition of estrogen receptor inhibitor ICI182. 780. Results When the concentrations of saikosaponin-d and estradiol were in the range of 0.01-5 μmol/L, 0.01-1 μmol/L respectively, luciferase activity was increased in a dose-dependent manner . Luciferase activity arrived the highest when saikosaponin-d concentration was 5 μmol/L and estradiol concentration was 1 μmol/L, but the effect was weakening when estradiol concentration reached 5μmol/L. In respect of the effect of treatment time, when HSC-T6 were separately treated with 5μmol/L of saikosaponin-d and 1 μmol/L of estradiol for 24 h, the luciferase activity was the highest. And ICI182.780 could significantly inhibit the induction of saikosaponin-d and estradiol for luciferase activity. Conclusion Saikosaponin-d has an effect on promoting the transcriptional activation of estrogen receptor in HSC-T6.

Construction of nuclear factor of activated T-cells 5 mRNA 3'-untranslated region reporter vector and targeting verification between NFAT5 and miR-155 / 重庆医学

Objective To construct a Luciferace reporter vector containing the 3'untranslated region (3'UTR) of NFAT5 and measure the correlation between NFAT5 and miR-155.Methods The miR-155 targeting NFAT5 3'UTR was predicted by Target Scan,Mir Base and Pic Tar.NFAT5 and mutant NFAT5 sequence(NFAT5-mu) were then designed and synthesized,and they were cloned into pMIR-REPORTTM Luciferace reporter vector.Human embryonic kidney-293AD (HEK-293AD) cells of the 4th passage were divided into 4 groups according to the random number table.cells in plasimd +miR-155 mimics groups were transfected with pMIR-NFAT5 recombinant plasimid,pRL-Tk plasmid and miR-155 mimics;cells in plasimd + miR-155 mutated groups were transfected with pMIR-NFAT5-mu recombinant plasimid,pRL-Tk plasmid and miR-155 mimics;cells in plasimd + miR-155 control groups were transfected with pMIR-NFAT5 recombinant plasimid,pRL-Tk plasmid and miR-155 Negative control;cells in plasimd +miR-155 inhibitor were transfected with pMIR-NFAT5 recombinant plasimid,pRL-Tk plasmid and miR-155 inhibitor;and were respectively transfected into together by liposome.After culture for 24 h,the luciferase activity was detected by dual luciferase reporter assay system.Results TargetScan,Miranda and PicTar shared the results that NFAT5 has the complementary binding sites with 3'UTR of miR-155.And luciferase reporter vectorwas constructed.Therefore the result of sequencing and double digesting of recombined plasmid were completely correct.Dual-luciferase reporter assay showed that miR-155 possesses a target effect on 3'UTR of NFAT5.Compared to the pMIR-NFAT5 + miR-control group,the luciferase activity of the pMIR-NFAT5 + miR-1 5 5 mimics group was decreased,with statistically significant difference(P＜0.01),while there was no significant difference at other time points(P＞0.05).Conclusion The pMIR-NFAT5 recombinant plasmid and pMIR-NFAT5 recombinant mutated plasmid were confirmed with successful construction.and it was found that miR-155 can target NFAT5 mRNA 3'-UTR.The results provide the experiment data for further disclosing the mechanism of inhalation injury on the level of gene expression.

Construction and function identification of luciferase reporter gene vectors containing SNPs in NFKBIA gene 3'UTR / 药学学报

This study aims to investigate the function of two SNPs (rs8904C > T and rs696G > A) in 3' untranslated region (3'UTR) of NFKBIA gene by constructing luciferase reporter gene. A patient's genomic DNA with rs8904 CC and rs696 GA genotype was used as the PCR template. Full-length 3'UTR of NFKBIA gene was amplified by different primers. After sequencing validation, these fragments were inserted to the luciferase reporter vector, pGL3-promoter to construct recombinant plasmids containing four kinds of haplotypes, pGL3-rs8904C/rs696G, pGL3-rs8904C/rs696A, pGL3-rs8904T/rs696G and pGL3-rs8904T/rs696A. Then these plasmids were transfected into LS174T cells and the luciferase activity was detected. Compared with pGL3- vector transfected cells (negative control), the luciferase activity of the four kinds of recombinant plasmids was significantly decreased (P A, the luciferase activity of the recombinant plasmids containing A allele (pGL3-rs8904C/rs696A and pGL3-rs8904T/rs696A) was about 45.1% (P P T, there were no significant differences in the luciferase activity between the recombinant plasmids containing T allele and those with C allele. Together, the luciferase reporter gene vectors containing SNPs in NFKBIA gene 3'UTR were constructed successfully and rs696G > A could decrease the luciferase activity while rs8904C > T didn't have much effect on the luciferase activity.

Identification of targeting relationship between mouse lncRNA-H19 and miR-199 a-5 p by dual-luciferase reporter assay / 中国病理生理杂志

AIM:To validate the association between long noncoding (lncRNA)-H19 and microRNA-199a-5p (miR-199a-5p) through the dual-luciferase reporter gene system by construction of a luciferase reporter vector containing the gene of lncRNA-H19.METHODS:The potential complementary binding sites of lncRNA-H19 and miR-199a-5p were predicted by RegRNA 2.0.The H19 gene or its mutant ( Mut) fragment was cloned into luciferase reporter vector psi-CHECK-2.Restriction enzyme analysis and sequence analysis were used to identify whether the recombinant plasmids of the H19 and H19-Mut were successfully constructed .miR-199a-5p mimics, miR-199a-5p inhibitor, miR-199a-5p mimics neg-ative control or miR-199a-5p inhibitor negative control was co-transfected into the 293T cells with the luciferase reporters containing H19 or H19-Mut.Dual-luciferase reporter assay was performed to detect the luciferase activity in different groups in order to verify the relationship between lncRNA-H19 and miR-199a-5p.RESULTS:The results of double enzyme diges-tion and DNA sequencing showed that the sequence of luciferase reporter vector was correct .The results of dual-luciferase reporter assay indicated that the H 19 reporter gene luciferase activity significantly decreased in miR-199a-5p mimics group by 49%(P<0.01), and the H19 reporter gene luciferase activity was obviously upregulated in miR-199a-5p inhibitor group compared with miR-199a-5p mimics group ( P<0.01).However, miR-199a-5p mimics, miR-199a-5p inhibitor, miR-199a-5p mimics negative control and miR-199a-5p inhibitor negative control showed no effect at H 19-Mut reporter gene.CONCLUSION:lncRNA-H19 binds to miR-199a-5p to exert an inhibitory effect at transcriptional level .

Construction of Nfic gene 3′UTR dual luciferase reporter vector and targeting verification between Nfic and miR-20a / 天津医药

Objective To construct a luciferase reporter vector containing the 3′untranslated region (3′UTR) of nuclear factor I-C (nuclear factor I-C, Nfic), and apply dual luciferase reporter gene system to determine the association between microRNA-20a (miR-20a) and its potential target gene Nfic. Methods The potential complementary binding sites of miR-20a and Nfic were predicted by Targetscan. The 3′UTR of Nfic fragment amplified by PCR was cloned into luciferase reporter vector MIR- Report Luciferase. The luciferase reporters containing 3′ UTR of Nfic and miR- 20 mimics (experimental group) or NC mimics (control group) were co-transfected into 293-AD cells. Cells were collected, and then dual-luciferase reporter assay was performed to detect the luciferase activity of the two groups of cells, consequently the relationship between miR-20a and Nfic was identified. The miR-20a mimics and NC mimics were transfected into marrow stromal cell line ST2 respectively. The total cell lysates were collected, and the expression level of NFIC was detected by Western blotting assay. Results Results of double enzyme digestion and DNA sequencing showed that sequence of luciferase reporter vector was correct. miR-20a specificity bounded to Nfic 3′UTR and inhibited the luciferase activity of the reporter construct (P<0.05). Western blotting assay showed that the NFIC protein level was obviously down-regulated in ST2 cells after the transfection of miR-20a mimics compared with that of control. Conclusion The luciferase reporter vector containing the 3′UTR of Nfic is constructed successfully, which confirms that miR-20a can direct effect on Nfic3′UTR and repress its luciferase activity.

Effects of puerarin on proliferation of osteoblasts and Runx2-targeting miRNAs / 中国药理学通报

Aim To study proliferation capacity of cell and the target relationship between microRNA and Runx2 after effect of puerarin on osteoblasts MC3 T3-E1 . Methods The proliferation capacity of cell was detected by MTT after effect of puerarin on osteoblasts MC3 T3-E1 . The vitality of osteoblasts was detected by activity of alkaline phosphatase. The expression level of mRNA and protein of Runx2 were detected by real-time quantitative PCR and Western blot. The result of miRNA expression spectrum was compared with the predicted result to determine the Runx2-targeting miR-NAs. The expression levels of miRNAs possiby targeted to Runx2 were detected by real-time quantitative PCR. The RhoE 3′UTR vector and RhoE mut 3′UTR vector were constructed. miRNA-204 mimics and miRNA-204 NC were synthetised. The target genes were verified by dual luciferase report gene assay. Results After osteo-blasts treated with puerarin, proliferation capacity and activity of cells were enhanced , expression levels of mRNA and protein of Runx2 were both increased , the expression levels of miRNA-204 and miRNA-344 f-5 p were declined, the expression levels of miRNA-2861 was increased,the expression levels of miRNA-23a-5p, miRNA-770-5 p and miRNA-871-5 p showed no obvious change. According to the results of dual luciferase re-porter gene method after cell transfection of 48 h, only set of 3′UTR Runx2+mimics the miRNA-204 of fluo-rescein protein expression level decreased significantly, showing only the miRNA-204 inhibits Runx2 3′UTR report gene expression. Conclusion Puerarin pro-motes the proliferation of osteoblasts and regulates the miRNAs which possibly target to Runx2 .

Establishment and verification of assay method for the receptor binding affinity of a PEGylated Exendin-4 analogue / 中国药科大学学报

@#The assay method of GLP-1 receptor binding affinity for a long-acting hypoglycemic peptide—PEgylated Exendin-4 analogue(PE)was optimized and established based on the luciferase reporter gene approach. CHO-GLP-1R-CRE-Luc+ cells were previously constructed in our lab followed by the verification of methodology. This assay method showed good specificity and robustness as well as high accuracy and precision when PE was incubated with the cell for 4 h, the luminescent substrate reacted with cell lysates for 15 min and the concentration for PE ranged 5. 7×10-3-1. 5×103 nmol/L, on which condition this developed method is in accordance with General Principles of Analytical Method Validation Techniques for Biological Products Quality Control. This study also lays the foundations for rapid evaluation and screening of GLP-1 receptor agonist drugs.

The identification of human microRNA335′s predicated target gene CCL1 1,CCL26 and SOX4 / 重庆医学

Objective To identify the targeted-regulating relationship between human MicroRNA335 (hsa-miR-335 )and CCL1 1,CCL26 and SOX4.Methods The potential fragments of hsa-miR-335 target genes CCL1 1,CCL26 and SOX4 were predicted by the bioinformatics analyzing tools online.The 3′untranslated regions(3′UTR)of the CCL1 1,CCL26 and SOX4 were connected to the eukaryotic expression vectors pMIR REPORT.The constructs of pMIR-REPORT-CCL1 13′UTR,pMIR-REPORT-CCL26 3′UTR,pMIR-REPORT-SOX4 3′UTR and positive control were co-transfected with Pre-miRTM miRNA335 Precursor or negative control into 293 T7/1 7 cell line by lipofectamine 2000,respectively.Both Firefly and Renilla luciferase activity were detected by dual luciferase reporter assay system.Results Compared with the negative control group,luciferase assay revealed that has-miR-335 could significantly diminish luciferase activity from SOX4 reporter vector (P 0.05).Conclusion The results suggested that hsa-miR-335 targeted regu-lated SOX4,but not targeted CCL1 1 and CCL26.

Construction and activity characterization of E-cadherin and N-cadherin promoters / 军事医学

Objective To clone E-cadherin and N-cadherin promoters and insert them into a luciferase reporter gene vector, and to characterize the promoter activity of E-cadherin and N-cadherin.Methods E-cadherin and N-cadherin pro-moter were cloned into pGL 4-basic.The resulting plasmids were determined by DNA sequencing .The promoter activity was analyzed in breast cancer cell line ZR 75-1 and hepatocarcinoma cell line HepG 2.Results DNA sequencing showed that the sequences of the cloned promoter regions were correct .Analysis of the reporter gene activity indicated that the E-cad-herin and N-cadherin promoters had the highest transcriptional activity in ZR 75-1 and HepG2 cells.Conclusion The E-cadherin and N-cadherin promoter genes are cloned successfully , contributing much to screening transcription factors that regulate E-cadherin and N-cadherin expression .

Establishment of a drug screening model based on anti-oxidative response element / 中草药

Objective: To establish a cell model for anti-oxidative drug screening by using anti-oxidative response element (ARE) to regulate the expression level of luciferase (Luc) reporter gene. Methods: The recombinant plasmid vector pARE-Luc-Neo, expressed by ARE-regulated Luc reporter gene, was constructed. The recombinant plasmid vector was transfected into human embryonic kidney epithelial cells (Hek293 cells) using FuGENE® HD transfection reagent. The positive cells were screened by G418, and the positive monoclonal cells were selected using the dilution method. The monoclonal cell lines with high activity of Luc reporter gene in response to anti-oxidative protein inducer TBHQ were obtained using the Luc activity detection. The screening effect of the positive clones was evaluated by resveratrol and curcumin. The effects of andrographolide, cryptotanshinone, silymarin, matrine, and polydatin at different concentration (0, 3.125, 6.25, 12.5, 25, 50, and 100 μmol/L) on Luc expression level were observed. Results: The Hek293-ARE cells were obtained by detecting the Luc reporter gene activity, the Luc reporter gene expression was regulated by ARE, meanwhile there exists a dose-response relationship between the expression level and the concentration of the inducer within a certain range. The andrographolide, cryptotanshinone, and silymarin have significant induction effects. Conclusion: The cell model for anti-oxidative drug screening is established successfully and could be effectively and high-throughput for the preliminary screening of anti-oxidative drugs.

Telomere position effect in gastric cancer cell SGC7901 / 第三军医大学学报

Objective To determine the possibility of telomere seeding in human gastric cancer cell SGC7901 and the influence of telomere on the expression of luciferase reporter gene nearby and to explore the position effect of telomere in gastric cancer cell. Methods The TET-OFF regulatory system was prepared and then transfected to gastric cancer cell SGC7901 by Lipofectamine TM 2000. With doxycycline added, the activity of the fluorescence caused by the expression of the target gene (the luciferase gene) with TET-OFF regulatory system was analyzed. The luciferase reporter plasmid in which telomere fragment pBX was inserted and the control plasmid pBX-ntf (no teloemere fragment) were co-transfected to cell 7901 with pTET-OFF regulate plasmid respectively and the luciferase activity was determined with doxycycline's induction. Results With the inducing of Dox, the activity of the fluorescence caused by the expression of the luciferase gene was inhibited. Treated with deoxycyline, there was a 4-fold decrease in the activity of the fluorescence in the cells infected with pBX and pTET-OFF as compared with that in the cells infected with pBX-ntf and pTET-OFF. Conclusion With the help of Lipofect2000, the gastric cancer cell SGC7901 can be transfected by TET-OFF regulatory system successfully. Dox could repress luciferase gene expression. Telomere seeding in gastric cancer cell SGC7901 could decrease the expression of luciferase reporter gene.

Association of Polymorphic Regulatory Region of TIGR Gene with Glaucoma

PURPOSE: To identify the polymorphism in the regulatory region of trabecular meshwork inducible glucocorticoid response(TIGR) gene and evaluate the association of it with glaucoma. METHODS: 5'regulatory region of TIGR gene of 101 normal persons and 91 unrelated glaucoma patients were analyzed by DNA sequencing and restriction enzyme digestion. To know the possible effects of the polymorphism on the transcription rate of TIGR gene, electrophoretic mobility shift assay and luciferase reporter gene assay were performed with cultured cells, and their extracts of trabecular meshwork and ciliary body in which the gene was expressed. RESULTS: Of the 480 bp examined, G to A transition(G-241A) located at 241 bp upstream from transcription start site was identified and its frequency of occurrence was proved to be higher in steroid induced glaucoma patients(18.9%) compared with that in normal population(8.9%), POAG(8.3%) and normal tension glaucoma patients(6.7%, P<0.05). In mobility shift assay, the G-241A probe was proved to have affinity to some DNA-binding proteins and its affinity was revealed to be two times stronger than that of normal sequence. The luciferase activities, however, were observed to be similar in cells transfected with vectors having normal promoter sequence or G-241A containing one. CONCLUSION: The result suggest that G-241A itself is not a cause of steroid-induced glaucoma but is in linkage disequilibrium with the actual causes of the disease.