Construction of recombinant plasmids Egr1-XPO4 and its synergic inhibition with 5-FU against hepatocarcinoma SK-Hep1 cells / 中国肿瘤生物治疗杂志

@#[Abstract] Objective: To construct recombinant plasmid Egr1-XPO4 and evaluate its synergic inhibition with 5-FU against hepatocarcinoma SK-Hep1 cells. Methods: The XPO4 gene was inserted into vector carrying promoter Egr1 to construct a new recombinant vector, Egr1-XPO4, which was then transfected into human hepatocarcinoma cell line SK-Hep1 and sensitized with chemotherapeutic drug 5-FU. Western blotting was adopted to examine the protein expression of XPO4; CCK assay was used to detect SK-Hep1 cell proliferation after transfection, and Flow Cytometry with Annexin V-FITC/PI staining was used to detect the apoptosis of SK-Hep1 cells. SKHep1 cell xenograft model was constructed on nude mice, and the effect of Egr1-XPO4 in combination with 5-FU on the growth of xenograft was observed. Results: The recombinant plasmid Egr1-XPO4 was successfully constructed.With the sensitization of 5-FU, the expression of XPO4 protein in SK-Hep1 cells was significantly elevated after Egr1-XPO4 transfection, and the evlevation was in a 5FU dose-depend manner.The combined treatment of Egr1-XPO4 and 5-FU produced a significantly stronger inhibition against SKHep1 cell proliferation and greatly promoted apoptosis of SK-Hep1cells compared with 5-FU or pEgr-XPO4 mono-treatment group (all P<0.05). And in vivo antitumor experiment showed that the tumor volume in Egr1-XPO4+5-FU treatment group was significantly smaller than that of Egr1-XPO4 or 5-FU mono-treatment group (P<0.05). Conclusion: The recombinant plasmid Egr1-XPO4 in combination with 5-FU could exertsynergic inhibitionagainst hepatocarcinomaSK-Hep1 cells.

Inhibitory effect of pshuttle-Egr-1-hSmac plasmid combined with X-ray irradiation on proliferation of breast cancer MDA-MB-435 cells / 吉林大学学报(医学版)

Objective To construct the pshuttle-Egr-1-hSmac plasmid and transfect human breast cancer MDA-MB-435 cells,and to observe its radiotherapy enhancing effect on tumor cells.Methods The empty vector pshuttle and pshuttle-Egr-1-hSmac plasmid were transfected into MDA-MB-435 cells by liposomal.At different time(4,8,12,24 and 48 h)after irradiation with 2.0 Gy X-ray and 24 h after irradiation with 0.5 -5.0 Gy,the total RNA and protein were collected and extracted from these cells to analyze the Smac mRNA and protein expression levels with RT-PCR and Western blotting methods. The cells were divided into control, pshuttle, pshuttle-Egr-1-hSmac,2.0 Gy irradiation group, pshuttle + 2.0 Gy irradiation and pshuttle-Egr-1-hSmac+2.0 Gy irradiation groups.MTT method was used to evaluate cell proliferation,and the cell survival ability was measured with clone formation assay;Annexin Ⅴ/PI double staining and PI single staining were used to examine the apoptosis and cell cycle of MDA-MB-435 cells. Results There was no Smac mRNA expression in MDA-MB-435 cells in control and pshuttle groups,but the Smac mRNA expression levels in MDA-MB-435 cells in pshuttle-Egr-1-hSmac plasmid group were gradually increased with the time prolongation, and reached the maximum at 24 and 48 h;the Smac mRNA expression levels in MDA-MB-435 cells were increased gradually 24 h after irradiation of 0.5 - 5.0 Gy X-ray with the increasing of irradiation doses, and reached the maximum after 2.0 and 5.0 Gy irradiation. The Smac protein expression levels in pshuttle-Egr-1-hSmac plasmid group were increased gradually with the time prolongation,and reached the maximum at 24 h.The Smac protein expression lervels were increased 24 h afer irradiation of 0,0.5,1.0,2.0 and 5.0 Gy X-ray,especially in 5.0 Gy group. The MTT results showed that the A490 values in 2.0 Gy,pshuttle+2.0 Gy and pshuttle-Egr-1-hSmac groups 24, 48,and 72 h after irradiation were lower than those in control group(P<0.01);the A490 values of MDA-MB-435 cells in pshuttle-Egr-1-hSmac group after 1.0-5.0 Gy X-ray irradiation were lower than those in 0 Gy group (P<0.05 or P<0.01);the survival fraction(SF)in pshuttle-Egr-1-hSmac group was lower than those in control group (P<0.01).The percentages of the cells at G0/G1 and S phase in pshuttle-Egr-1-hSmac group were lower than those in 2.0 Gy group(P<0.01),the percentage of the cells at G2/M phase was higher than that in 2.0 Gy group (P<0.01);the apoptotic rate of the cells in pshuttle-Egr-1-hSmac group was higher than that in 2.0 Gy group (P<0.01).Conclusion X-ray irradiation can significantly increase the Smac mRNA and protein expression levels in MDA-MB-435 cells transfected with pshuttle-Egr-1-hSmac plasmid,inhibit the cell survival rate,and induce G2/M arrest and apoptotic increasing;Smac gene combined with radiotherapy could significantly increase the radiosensitivity of breast cancer cells.

Enhanced Effects of TRAIL-endostatin-based Double-gene-radiotherapy on Suppressing Growth, Promoting Apoptosis and Inducing Cell Cycle Arrest in Vascular Endothelial Cells / 华中科技大学学报（医学）（英德文版）

This study examined the effects of TRAIL-endostatin-based gene-radiotherapy on cellular growth,apoptosis and cell cycle progression in human vascular endothelial cells ECV304 in vitro.The expression of TRAIL and endostatin protein in ECV304 cells was detected by ELISA after the transfection of recombinant plasmid pshuttle-Egrl-shTRAIL-shES and X-ray irradiation.Then MTT assay was used for determining the cellular proliferation,and flow cytometry (FCM) plus Annexin V and propidium iodide (PI) double-staining or PI single-staining were employed for the detection of apoptosis and cell cycle progression.The results showed that expression of TRAIL and endostatin protein exhibited a time- and dose-dependent change in ECV304 cells after pshuttle-Egrl-shTRAIL-shES transfection in conjunction with irradiation.In the TRAIL-endostatin-based single- or double-gene-radiotherapy,the cell viability declined in a time- and dose-dependent manner,the percentage of cells at G2/M phase and apoptotic rate was increased,and the percentage of cells at G0/G1 phase was lowered as compared with those receiving radiotherapy alone.Moreover,TRAIL-endostatin-based double-gene-radiotherapy demonstrated better effects on growth inhibition,promotion of apoptosis and induction of cell cycle arrest in ECV304 cells than single-gene-radiotherapy.

Construction of human Egr-1 promoter and its response to ionizing radiation in tumor cells / 细胞与分子免疫学杂志

AIM: To construct human Egr-1 promoter luciferase reporter system and study its activity induced by i-onizing radiation. METHODS: Egr-1 promoter was obtained by human genomic PCR and cloned into pGL3-basic vector. After transfection of recombinant plasmid into human tumor cells, the Egr-1 promoter activity induced by ionizing radiation was detected by luciferase reporter assay. RESULTS: The luciferasy reporter system of Egr-1 promoter was successfully constructed. The activity of Egr-1 promoter was substantially increased after different doses of IR and reached to the peak at the time point of 48h after IR. CONCLUSION: The Egr-1 promoter was constructed in this study showed IR inducible activity in tumor cells, laying foundation for the research of radiation, mediated gene therapy.

Construction of recombinant adenovirus with Egr-1 promoter and Smad7 / 中国癌症杂志

Purpose:To construct replication-defective adenovirus which was recombinated with Egr-1 promoter and to Smad7, and to study whether it can express exogenous Smad7 protein in cytoplasm.Methods:Based on Adeno-X~(TM) expression system, the CMV promoter of the pShuttle vector was replaced by Egr-1 promoter, and the Smad7 cDNA was subcloned into the MCS(multiple cloning site) of pShuttle. The recombinant pShuttle was then subcloned into the Adeno-X~(TM) genome, which was transformed into E.coli to get recombinant Adeno-X~(TM) plasmid DNA. The recombinant adenovirus was made and amplified in the transfected HEK 293 cells before it was purified and tested for viral titer. Then the Smad7’s location in cells was determined by immunocytochemistry.Results:Identified by restriction endonuclease analysis and PCR, recombinant adenovirus with Egr-1 promoter and Smad7 cDNA was constructed successfully, with a viral titer of 1.0?10~(11) TCID50/ml. Both endogenous and exogenous Smad7 protein was found to be located in cytoplasm of fibroblast cells.Conclusions:With Adeno-X~(TM) expression system, utilizing the techniques of molecular cloning, recombinant adenoviral vector could be quickly and efficiently constructed which could be packaged into replication-defective Adenovirus and amplified in HEK293 cells. The recombinant adenovirus could express exogenous Smad7 protein in fibroblast cells.[

In vivo study on adenovirus mediating Smad 7 gene expression regulated by radiation via Egr-1 promoter / 中华放射肿瘤学杂志

Objective To investigate the time-effect relationship and dose-effect relationship of the expression of adenovirus mediating Smad 7 gene regulated by irradiation via Egr-1 promoter in the lung of C57BL mice. Methods Recombinant adenovirus (AD.Egr-Smad 7) was made up through replication-defective adenovirus enclosed radio-inducible elements from the Egr-1 gene promoter and cDNA encoding Smad 7. Mice infected by intratracheal instillation with AD.Egr-Smad 7 were irradiated to their whole lungs after 24 hours. 324 mice were randomly divided into 6 groups, and the lungs were harvested at different time points following irradiation with single dose of 8?Gy to observe the time-effect relationship of Smad7 gene expression with different time intervals. 108 mice randomly divided into 3 groups were irradiated respectively by different single irradiation dose and the lungs were harvested 5 hours after radiation to evaluated the dose-effect relationship of Smad 7 gene expression with different radiation doses. The expression of exogenous Smad 7 was detected by Western blot analysis. Results The expression of adenovirus mediating Smad 7 gene regulated by Egr-1 promoter could be induced by radiation markedly as compared with the control groups(P

Radiation-inducible expression of human perforin N-terminal in lung cancer cells / 中国免疫学杂志

Objective:To construct an eukaryotic radiation-inducible expressing vector of the human perforin N-terminal(hPFN-N),and to investigate the distribution and the killing effect of human perforin N-terminal truncated 118 amino acid polypeptide (rhPFN-N,22-139aa) on tumor cells.Methods:The gene hPFN-N was amplified by PCR from the plasmid pcDNA3.1(+)/hPFN and an enkaryotic radiation-inducible expression vector pcDNA3.1(+)/ Egr-hPFN-N was constructed after DNA recombination.After transfecting SPC-A1 cells with this recombination vector via liposome mediation,the expression of the hPFN-N protein was detected by RT-PCR and Immunocytochemical method and the killing effect of hPFN-N protein was assessed by standard MTT chromatometry.Results:DNA sequencing and restriction endonuclease digestion analysis indicated that the eukaryotic radiation-inducible expressing vector pcDNA3.1(+)/ Egr-hPFN-N had been constructed successfully.After the recombinant plasmid being transfected into SPC-A1 cells and being irradiated by X ray,RT-PCR verified the expression of hPFN-N mRNA.The result of Immunocytochemical assay was positive and in MTT assay the killing activity of rhPFN-N on target cells was 29.2%.Conclusion:After being irradiated the hPFN-N gene is expressed on the cell membrane and the killing activity of rhPFN-N on target cells is 29.2%.