Effect of viral macrophage inflammatory protein Ⅱ on the expression of APOBEC3G in 293T cells / 中华皮肤科杂志

Objective@#To assess the effect of viral macrophage inflammatory protein (vMIP) -Ⅱ on the expression of apolipoprotein B mRNA-editing enzyme-catalytic polypeptide-like 3G (APOBEC3G) , and to explore the mechanisms.@*Methods@#A recombinant plasmid pEGFP-N3-K4 (vMIP-Ⅱ plasmid group) and an empty plasmid pEGFP-N3 (empty plasmid group) were separately transfected into 293T cells, and quantitative PCR and Western blot analysis were performed to evaluate the effect of transfection with vMIP-Ⅱ gene on the APOBEC3G expression in 293T cells. Some 293T cells in the empty plasmid group and vMIP-Ⅱ plasmid group were treated with 1 000 IU/ml interferon (IFN) -α for 36 hours, and then Western blot analysis was conducted to determine the APOBEC3G expression in the empty plasmid group and vMIP-Ⅱ plasmid group with or without IFN-α treatment. Some 293T cells transfected with vMIP-Ⅱ plasmids were treated with 75 μmol/L AG490 (a JAK/STAT signaling pathway inhibitor) and 20 μmol/L U0126 (an ERK signaling pathway inhibitor) separately; after 24 hours, total protein was extracted from 293T cells, and Western blot analysis was conducted to determine the expression of APOBEC3G. A recombinant plasmid containing APOBEC3G promoter was constructed by using a luciferase reporter gene, and the promoter fragment included the full-length promoter sequence (POS) of APOBEC3G, sequences with the lengths of 1 560, 960, 720, 480, 420, 360, 330 and 240 bp, and the regulatory element-free region (NEG) of APOBEC3G, separately. Some 293T cells were co-transfected with the recombinant plasmid carrying luciferase reporter gene and vMIP-Ⅱ plasmid (experimental group), or the recombinant plasmid and empty plasmid (control group). Subsequently, the activity of the APOBEC3G promoter was evaluated, and the key promoter region through which the transcriptional activity of APOBEC3G was regulated by vMIP-Ⅱ was analyzed. Statistical analysis was carried out by using t test, one-way analysis of variance and least significant difference (LSD) -t test.@*Results@#The mRNA and protein expression of APOBEC3G was significantly higher in the vMIP-Ⅱ plasmid group (2.500 ± 0.013, 1.472 ± 0.013 respectively) than in the control group (1, 0.364 ± 0.030 respectively; t = 6.22, 6.54 respectively, both P < 0.05) . The APOBEC3G expression significantly differed among the empty plasmid group, vMIP-Ⅱ plasmid group, empty plasmid + IFN-α group and vMIP-Ⅱ plasmid + IFN-α group (1, 2.030 ± 0.108, 2.700 ± 0.081 and 2.600 ± 0.099 respectively; F = 67.026, P < 0.001) , but there was no significant difference between the vMIP-Ⅱ plasmid group and empty plasmid + IFN-α group (t = 3.46, P > 0.05) . The APOBEC3G expression also significantly differed among the vMIP-Ⅱ plasmid group, vMIP-Ⅱ plasmid + AG490 group and vMIP-Ⅱ plasmid + U0126 group (0.617 ± 0.025, 0.179 ± 0.061, 0.359 ± 0.012 respectively; F = 70.019, P < 0.001) , and was significantly lower in the vMIP-Ⅱ plasmid + AG490 group and vMIP-Ⅱ plasmid + U0126 group than in the vMIP-Ⅱ plasmid group (t = 9.66, 11.836 respectively, both P < 0.01) . Luciferase activity assay showed that the promoter activity significantly differed among the vMIP-Ⅱ plasmid groups transfected with POS, 1 560-, 960-, 720-, 480-, 420-, 360-, 330-, 240-bp or NEG sequences (F = 81.092, P < 0.001) , and the APOBEC3G promoter activity decreased greatly from the 720-bp group to 480-bp group.@*Conclusion@#vMIP-Ⅱ upregulates the expression of APOBEC3G, likely through the JAK/STAT signaling pathway or the key promoter region regulating the transcriptional activity of APOBEC3G.

Effect of viral macrophage inflammatory protein Ⅱ on the expression of APOBEC3G in 293T cells / 中华皮肤科杂志

Objective To assess the effect of viral macrophage inflammatory protein (vMIP)-Ⅱ on the expression of apolipoprotein B mRNA-editing enzyme-catalytic polypeptide-like 3G (APOBEC3G),and to explore the mechanisms.Methods A recombinant plasmid pEGFP-N3-K4 (vMIP-Ⅱ plasmid group) and an empty plasmid pEGFP-N3 (empty plasmid group) were separately transfected into 293T cells,and quantitative PCR and Western blot analysis were performed to evaluate the effect of transfection with vMIP-]Ⅱ gene on the APOBEC3G expression in 293T cells.Some 293T cells in the empty plasmid group and vMIP-Ⅱ plasmid group were treated with 1 000 IU/ml interferon (IFN)-α for 36 hours,and then Western blot analysis was conducted to determine the APOBEC3G expression in the empty plasmid group and vMIP-Ⅱ plasmid group with or without IFN-α treatment.Some 293T cells transfected with vMIP-Ⅱplasmids were treated with 75 μ mol/L AG490 (a JAK/STAT signaling pathway inhibitor) and 20 μ mol/L U0126 (an ERK signaling pathway inhibitor) separately;after 24 hours,total protein was extracted from 293T cells,and Western blot analysis was conducted to determine the expression of APOBEC3G.A recombinant plasmid containing APOBEC3G promoter was constructed by using a luciferase reporter gene,and the promoter fragment included the full-length promoter sequence (POS) of APOBEC3G,sequences with the lengths of 1 560,960,720,480,420,360,330 and 240 bp,and the regulatory element-free region (NEG) of APOBEC3G,separately.Some 293T cells were co-transfected with the recombinant plasmid carrying luciferase reporter gene and vMIP-Ⅱ plasmid (experimental group),or the recombinant plasmid and empty plasmid (control group).Subsequently,the activity of the APOBEC3G promoter was evaluated,and the key promoter region through which the transcriptional activity of APOBEC3G was regulated by vMIP -Ⅱ was analyzed.Statistical analysis was carried out by using t test,one-way analysis of variance and least significant difference (LSD)-t test.Results The mRNA and protein expression of APOBEC3G was significantly higher in the vMIP-Ⅱ plasmid group (2.500 ± 0.013,1.472 ± 0.013 respectively) than in the control group (1,0.364 ± 0.030 respectively;t =6.22,6.54 respectively,both P ＜ 0.05).The APOBEC3G expression significantly differed among the empty plasmid group,vMIP-Ⅱ plasmid group,empty plasmid + IFN-oα group and vMIP-Ⅱ plasmid + IFN-α group (1,2.030 ± 0.108,2.700 ± 0.081 and 2.600 ± 0.099 respectively;F =67.026,P ＜ 0.001),but there was no significant difference between the vMIP-Ⅱ plasmid group and empty plasmid + IFN-α group (t =3.46,P ＞ 0.05).The APOBEC3G expression also significantly differed among the vMIP-Ⅱ plasmid group,vMIP-Ⅱ plasmid + AG490 group and vMIP-Ⅱplasmid + U0126 group (0.617 ± 0.025,0.179 ± 0.061,0.359 ± 0.012 respectively;F =70.019,P ＜ 0.001),and was significantly lower in the vMIP-Ⅱ plasmid + AG490 group and vMIP-Ⅱ plasmid + U0126 group than in the vMIP-Ⅱ plasmid group (t =9.66,11.836 respectively,both P ＜ 0.01).Luciferase activity assay showed that the promoter activity significantly differed among the vMIP-Ⅱ plasmid groups transfected with POS,1 560-,960-,720-,480-,420-,360-,330-,240-bp or NEG sequences (F =81.092,P ＜ 0.001),and the APOBEC3G promoter activity decreased greatly from the 720-bp group to 480-bp group.Conclusion vMIP-Ⅱ upregulates the expression of APOBEC3G,likely through the JAK/STAT signaling pathway or the key promoter region regulating the transcriptional activity of APOBEC3G.

Establishing a luciferase reporter system to evaluate osteogenic differentiation poten-tial of human adipose-derived stem cells / 北京大学学报(医学版)

Objective:Human adipose-derived stem cells (hASCs)are a highly attractive source in bone tissue engineering.To generate a luciferase reporter system that could be used to quantitatively and rapidly examine osteogenic differentiation potential of human adipose-derived stem cells (hASCs ) in vitro,and eventually make it possible to monitor the osteogenic differentiation of transplanted cells in vi-vo.Methods:The genomic DNA harboring promotor regions of osteocalcin and DNA sequences encoding luciferase genes were amplified by PCR and cloned into the pLVX-pTRE-puro vector to generate the OCpro-Luc-Puro construct.Then,the OCpro-Luc-Puro construct together with three assistant vectors:pM-DLg/pRRE,pRSV-REV,and pVSVG,were transiently transfected into HEK293T cells followed by viral supernatants collection,filtration and concentration.Next,the hASCs stably expressing luciferase repor-ter gene driven by osteocalcin promotor were created with the lentivirus carrying OCpro-Luc-Puro cassette under puromycin selection.The OCpro-Luc-hASCs were then cultured in the absence or presence of osteo-genic differentiation medium.On the 7th and 1 4th days,after osteogenic induction,cellular extracts were collected and analyzed by luciferase reporter assay.Meanwhile,alizarin red staining and quantification as well as quantitative reverse transcription PCR (qRT-PCR)analysis of osteogenic associated genes osteo-calcin (OC),runt-related transcription factor 2 (Runx2)and alkaline phosphatase (ALP)were used to assess the osteogenic differentiation ability of OCpro-Luc-hASCs.Results:OCpro-Luc-Puro plasmid and OCpro-Luc-hASCs were successfully generated.On the 7th and 1 4th days after osteogenic induction,the luciferase activity of the cellular extracts from OCpro-Luc-hASCs was dramatically increased.Consistently, the extracellular matrix mineralization,as shown by Alizarin red S (ARS)staining and quantification was also markedly intensified and a marked increase of the mRNA expression levels of OC,Runx2 and ALP, although to variable extent,was observed upon osteogenic differentiation.These results indicated that the observations from traditional experiments examining hASCs osteogenic differentiation were largely in agreement with that of our luciferase reporter assay in OCpro-Luc-hASCs.Conclusion:We established a luciferase reporter system that could be used to rapidly,quantitatively and specifically determine osteo-genic differentiation ability of hASCs.Comparing with the traditional time-consuming methods,the system we generated here was highly effective.This system not only can be used to examine ostogenic differentia-tion of hASCs in a high throughput manner,but also provides a way to monitor ostogenic differentiation of cells in vivo.

Are Podoplanin Gene Polymorphisms Associated with Atopic Dermatitis in Koreans?

BACKGROUND: The histologic characteristics of atopic dermatitis (AD) include perivascular edema and dilated tortuous vessels in the papillary dermis. A single nucleotide polymorphism (SNP) of the fms-related tyrosine kinase 4 (FLT4) gene is associated with AD. OBJECTIVE: To investigate the associations between podoplanin (PDPN) gene SNPs and AD. METHODS: We genotyped 9 SNPs from 5 genes of 1,119 subjects (646 AD patients and 473 controls). We determined the promoter activity of 1 SNP (rs355022) by luciferase assay; this SNP was further investigated using 1,133 independent samples (441 AD patients and 692 controls). RESULTS: The rs355022 and rs425187 SNPs and the C-A haplotype in the PDPN gene were significantly associated with intrinsic AD in the initial experiment. The rs355022 SNP significantly affected promoter activity in the luciferase assay. However, these results were not replicated in the replication study. CONCLUSION: Two SNPs and the C-A haplotype in the PDPN gene are significantly associated with intrinsic AD; although, the results were confirmed by luciferase assay, they could not be replicated with independent samples. Nevertheless, further replication experiments should be performed in future studies.

Construction and ldentification of Cell Division Cycle 2 Promoter Reporter Gene Vector / 天津医药

Objective To construct the luciferase reporter gene vector of cell division cycle 2 (Cdc2) gene promoter and determine its transcriptional activity. Methods Primers were designed based on human Cdc2 promoter sequence from UCSC software. Then Cdc2 promoter from human genome DNA was replicated. After pGL3-Basic vector and Cdc2 promoter were digested with restriction enzymes SacⅠand XhoⅠseparately, Cdc2 promoter was inserted into pGL3-Basic vector. The recombinant plasmid named pGL3-Cdc2-promoter was transiently co-transfected into U2OS cells with control vector pRL-SV40, and then the activity of dual luciferase was detected. Results pGL3-Cdc2-promoter was constructed successfully. The restriction analysis and sequencing proved the entirely correct sequencing results. The luciferase activity was higher in pGL3-Cdc2-promoter/pRL-SV40 group than that of pGL3-Basic/pRL-SV40 group (1.591 5±0.199 8 vs 0.049 9±0.010 4). Conclusion pGL3-Cdc2-promoter can be transcribed and activated in U2OS cells. This study provided an important basis for screening and evaluation of anticancer drugs.

Construction of X IAP-3′UTR-luciferase reporter vector and its activity analysis / 国际检验医学杂志

Objective To construct the recombinant X-linked inhibitor of apoptosis protein(XIAP) gene 3′untranslational region (3′UTR)-luciferase reporter vector ,and analyze the microRNA(miRNA) which possibly regulate the expression of XIAP gene . Methods Polymerase chain reaction (PCR) was employed to amplify X IA P-3′UTR sequences from human cDNA ,in which luciferase reporter vector pGL3-Ctrl was inserted ,and the recombinant vector pGL3-Ctrl/XIAP was gained .Target Scan 6 .2 soft-ware was adopted to predict the miRNA which possibly combined with the X IA P-3′UTR .pGL3-Ctrl/XIAP recombinant plasmids and the miRNA were co-transfected into A549 cells ,and the X IA P-3′UTR-luciferase activity was measured .Results Confirmed by digestion and DNA sequencing ,the X IA P-3′UTR-luciferase reporter recombinant was successfully constructed .Prediction of miRNA target sites indicated that X IA P gene may be the target of miR-200b ,miR-200c and miR-429 .Compared with miRNA mim-ic ctrl group ,miR-200b ,miR-200c and miR-429 significantly reduced the luciferase activity of pGL 3-Ctrl/XIAP with statistically significant difference(P<0 .05) .Conclusion X IA P-3′UTR-luciferase reporter vector is successfully constructed .miR-200b ,miR-200c and miR-429 can obviously decrease the luciferase activity .

Study on ATP bioluminescence in assaying the cleaning quality of uterine suction / 中国基层医药

Objective To explore the application value of ATP bioluminescence in assaying the cleaning quality of uterine suction.Methods According to the principle of random,we selected 120 uterine suction tube after use.60 used tubes in A group were given water immersion + high-pressure water jets wash + dry method,60 used tubes in B group were given alkaline cleaning solution soak + ultrasonic + high-pressure water washing + manual scrub + drying method.The quality of suction tube was initially tested with the visual method after cleaning,Straw inside the top cavity,2.5cm at inside straw joint and the front of straw outer wall,10cm at suction cavity wall,before and after cleaning the residues of bacteria were assayed with the ATP bioluminescence and bacteria counting method for parallel comparison.Results After cleaning drying program,the RLU of two groups in suction head internal top,2.5cm at inside straw joint,the front of straw outer wall,10cm at suction cavity wall had significant differences (t =26.81,29.13,7.14,55.74,P ＜ 0.01).The cleaning effect of B group was better than A group..Bacteria counting method was used to detect pathogenic microorganism that was not detected.The qualified rate of cleaning at four parts was as following:group A:70.0％,85.0％,93.3％,93.3％.B group:95.0％,98.3％,100.0％,100.0％,and the qualified rate of group B was significantly higher than group A (x2 =12.99,6.98,4.14,4.14,all P ＜ 0.05).Conclusion ATP bioluminescence method can dynamically rapid detect the bacteria before and after intrauterine suction cleaning residues,can be viewed as an effective method to detect quality of uterine suction cleaning.

Construction of mouse DUSP1 3'-UTR dual luciferase reporter system and its function identification / 解放军医学杂志

Objective To construct mouse dual specificity phosphatase-1 (DUSP1) 3'-untranslated region (3'-UTR) dual luciferase reporter system, and to identify its function. Methods The total RNA of RAW264.7 murine macrophage cells was extracted and reverse-transcribed into cDNA. The full length of mouse DUSP1 3'-UTR fragment was amplified by PCR and sub-cloned to the immediate downstream of luciferase cDNA in pGL3-control luciferase expression plasmid to obtain the recombinant plasmid pGL3-Luc-DUSP1- 3'UTR (LuDP). LuDP was then verified by PCR, restriction endonuclease and DNA sequencing analysis. Plasmid LuDP was transiently co-transfected into NIH3T3 cells with internal control plasmid pRL-TK, and the effects of DUSP1 3'-UTR on the expression of attached luciferase gene was analyzed with dual luciferase reporter assay system 48 hours after transfection. Both the luciferase expression module from LuDP and renilla luciferase expression module from pRL-TK were co-subcloned into pLenti6-TR vector to construct dual luciferase reporter plasmid LuDP/RL. The recombinant plasmid LuDP/RL was co-transfected with pcDNA3.1-HuR-FLAG (the eukaryotic expression plasmid of binding protein HuR) and miRNA mimics mmu-miR-101a into NIH3T3 cells respectively. The effects of HuR and mmu-mi-R101a on the expression of DUSP1 3'-UTR attached luciferase gene were also analyzed with dual luciferase reporter assay system. Results The dual luciferase reporter plasmid LuDP/RL was successfully constructed. The mouse DUSP1 mRNA 3'-UTR significantly down-regulated the expression of attached luciferase gene in NIH3T3 cells (0.14 ±0.01 fold, P<0.01). The co-transfected HuR up-regulated the expression of luciferase in LuDP/RL plasmid (1.40 ± 0.20 fold, P<0.05), and co-transfected mmu-miR-101a down-regulated the expression of LuDP/RL (0.57 ± 0.18 fold, P<0.05). Conclusion The constructed dual luciferase reporter plasmid LuDP/RL can be used to analyze the regulatory mechanism of mouse DUSP1 gene expression controlled by post-transcriptional regulatory elements.

Construction of human surfactant protein B promoter luciferase reporter gene vectors and detection of their activities / 中国医师杂志

Objective To construct human surfactant protein B (SP-B) gene promoter luciferase reporter plasmids and detect their transcriptional activities in H441 cells.Methods (1)The fragment of SP-B promoter (-218/+ 435 bp) was acquired from human genome DNA by polymerase chain reaction (PCR) amplification and then was inserted into pGM-T vector by the T4 DNA ligase.The vector was transfected into TOP10 E.coli.The positive clone was identified by DNA sequencing.The identified target SP-B promoter sequence was cloned into pGL3-basic vector to construct the recombinant vector pGL3-basic-SP-B-promoter and was identified by enzyme digestion and sequencing; (2)The pGL3-basic-SP-B-promoter vector was converted into pGL4.17-SP-B-promoter vector through enzyme digestion.The identified recombinant vectors and control plasmid pRL-TK were transfected into H441 cells by lipofectamine 2000,and luciferase assays was performed using the dual-luciferase reporter assay system.Results The sequences of SP-B promoter in the recombinant luciferase reporter plasmids were consistent with the one published on Genebank.The firefly/renilla luciferase activity ratio of pGL3-basic/pGL4.17-SP-B-promoter vector (2.8 ± 1.1,66.5±3.8) was significantly higher than pGL3-Basic,pGL4.17 control vector (0.2 ±0.1,4.3 ±0.4) with statistical significance (t =4.182,27.419,P =0.000),respectively.The SP-B promoter activity of pGL4.17-SP-B-promoter vector was significantly higher than pGL3-basic-SP-B-promoter vector (t =27.712,P =0.000).Conclusions The pGL3-basic/pGL4.17-SP-B-promoter vectors are successfully constructed with SP-B promoter activity in H441 cells and pGL4.17-SP-B-promoter vector is the better choice for further study with higher luciferase activity.

Establishment of cell strains stably-transfected with luciferase gene mediated by retrovirus and their detection with bioluminescence imaging system / 解放军医学杂志

Objective To establish cell strains stably transfected with Luciferase gene (Luc2), which was mediated by retrovirus, and explore the relationship between the number of Luc2-positive cells and light flux from bioluminescence imaging system by experiments in vitro and in vivo. Methods We co-transfected pMX-Luc2 plasmid and pMD.G plasmid into 293T gag-pol cells to get retrovirus expressing Luc2 gene. Stable Luc2 positive cell lines were generated and screened by transduction of Retro-Luc2 in mouse colon cancer cell line CT26, human non-small cell lung cancer cell line NCI-H446, human colon cancer cell line HT-29, human ovarian carcinoma cell line SKOV3 and human hepatocellular carcinoma cell line SMMC-7721, all of them were identified by bioluminescence imaging system. Different numbers of SKOV3-Luc2 cells ranging from 10 to 10000 were plated onto culture dishes. Two xenograft models of ovarian cancer were reproduced by subcutaneous injection of 200μl SKOV3-Luc2 cell suspension with different concentrations (1×107, 5×106, 2.5×106, 1×106, 5×105, 2.5×105, 1×105 and 5×104/ml) into 16 sites on the back of 4 nude mice, or intravenous injection of 1×106 or 3 ×106 SKOV3-Luc2 cells into the tail vein. Light flux value of SKOV3-Luc2 cells in dishes and in mice was measured by bioluminescence imaging system. Results Retro-Luc2 was constructed successfully and expressed Luc2 stably in transduced CT26, NCI-H446, HT-29, SKOV3 and SMMC-7721 cell lines. Light flux was correlated in a linear manner with the number of Luc2-positive cells in dishes and in mice (R2=0.944, β=0.972; R2=0.991, β=0.996; R2=0.351, β=0.628; P < 0.01). Conclusion Luc2-positive cell lines could be established rapidly and accurately by infecting tumor cells with retrovirus expressing Luc2. The number of Luc2 positive cells is significantly related in a linear manner to light flux from bioluminescence imaging system in vitro and in vivo.

Application of optical molecular imaging for the development of anticancer drugs / 国际肿瘤学杂志

Optical molecular imaging call non-invasively, quantitatively, real-time and dynamically monitor the biological processes in vivo, and enhance the understanding of disease and drug activity in the drug development process, which has been effectively used for target identification, compounds screening. pharmacodynamic action, pharmacokinetics research and evaluation of drug effect.

Development of a cell culture system with consistently expression of whole hepatitis C virus gene and Renilla luciferase and its application / 中华传染病杂志

ObjectiveTo develop a cell culture system with consistent expression of whole hepatitis C virus (HCV) gene and Renilla luciferase gene and to facilitate the study on HCV pathogenesis and the screening of new antiviral drugs.MethodsRenilla luciferase (RLuc) reporter gene and a mutation that could yield higher virus gene expression were introduced into the C-terminus of non-structural protein 5A (NS5A) of the JFH1 viral genome by using recombinant PCR.The viral RNA was transfected into Huh7.5 cells.Naǐve Huh7.5 cells were infected by the supernatant from the viral RNA transfected cells.HCV replication and infection were determined by virus titration,Renilla luciferase assay,immunofluorescence assay and western blotting.IFN-α was used to evaluate the feasibility of this system for anti-HCV new drug screening.ResultsThe viral RNA replicated efficiently in transfected cells.These cells could produce high titer of HCV-Rluc reporter virus and the virus titer reached to 1.5 × 104 FFU/ml at day 15 of posttransfection.The activity of Renilla luciferase was inhibited by IFN-α in a dose dependent manner in Huh7.5 cells infected by HCV-Rluc reporter virus.ConclusionThe recombinant HCV-JFH1-Rluc reporter gene system is sensitive and efficient.It can be a useful tool for high throughput screening of anti-HCV drugs.

The establishment of an athymic mouse model bearing breast cancer monitored by an in vivo optical imaging system / 中华普通外科杂志

Objective To establish the athrmic inouse model of breast cancer in normal position and imitated metastatic breast cancer. Methods Breast cancer cells MDA-MB-231-luc carrying luciferase gene was injected into the athymie mice.The optieal imaging in vivo system was used to observe the establislament of the model. Reseults The breast tumor emerged after we planted the MDA-MB-231-lue cells in the mammary gland fatpads,the volume and photon of the tumor increased during the second weekto the fifth week.After injection by the tail vein,the tumors mainly located in the lungs While after infusion in the left alrtrium.the tumolrs metastate to all over the body. Conclusions We succeeded in the establishment of the athymic mice model of breast cancer.in situ and imitated metastatic breast cancer by iniection into the vena caudalis and the left alttrium.The optical imaging in vivo system could distinctly show the formation of the tumors.

Site-directed analysis of key transcriptional regulatory regions of ezrin gene in HeLa cells / 肿瘤

Objective: To identify key transcriptional regulatory regions of ezrin gene in HeLa cells, thus this work maked a preliminary study for revealing its transcriptional regulatory mechanism. Methods: The recombinant pGLB plasmids containing different lengths of DNA fragments upstream of translation initiation site of ezrin gene as reporter promoters were constructed using nested-deletion method, and the promoter activities were detected using dual-luciferase reporter assay system. The potential transcription factor binding sites at key transcriptional regulatory region of ezrin gene were predicted using on-line analyzing programme. Results: The recombinant pGLB plasmids containing different lengths of 5′-flanking region of ezrin gene were obtained. When the lengths of ezrin 5′-flanking region were reduced from - 1 324 to - 890, the transcriptional activity decreased by about 80%. If the length of 5′-flanking region were deleted from - 146 to - 32, the transcriptional activities were nearly abolished. Sp 1 transcriptional factor binding sites were ubiquitous at the - 1 324/ - 890 and - 146/ - 32 regions. Conclusion: The - 1 324/ - 890 and - 146/ - 32 regions were two key transcriptional regulatory regions of ezrin gene in HeLa cells. Sp 1 may be an important factor for regulating the transcription of ezrin gene.