Ubiquitin specific peptidase 22 regulates the transcription activity of mitogen-activated protein kinase kinase 6 gene / 中南大学学报(医学版)

To clone human mitogen-activated protein kinase kinase 6 (MKK6) gene promoter and explore its transcription activity by ubiquitin specific peptidase 22 (USP22).
 Methods: MKK6 gene promoter was amplified by PCR and two bases mutation within USP22 binding site was subsequently introduced. The wild type and mutant MKK6 promoter were inserted into the luciferase report vector pGL3-Basic, respectively. Recombinant plasmids were co-transfected with plasmid pRL-TK into HeLa cells, and the luciferase activities were measured by dual luciferase reporter system. Furthermore, the direct interaction between USP22 and MKK6 promoter was detected by chromatin immunoprecipitation (ChIP) assay. Finally, the MKK6 transcription activity was measured after knockdown of USP22.
 Results: The recombinant luciferase report vectors containing wild or mutant type of MKK6 promoter were successfully constructed. Mutation of USP22 binding site resulted in decrease of MKK6 promoter-driven luciferase activity in HeLa cells (P<0.05). USP22 could interact directly with MKK6 promoter. Down-regulation of USP22 led to the decreased MKK6 mRNA expression (P<0.05).
 Conclusion: USP22 could regulate the transcription activity of MKK6 gene in HeLa cells.

Cloning of IPO8 promoter and analysis of its transcription activity / 中南大学学报(医学版)

OBJECTIVE@#To clone 5' untranslated region of human IPO8 gene and determine its transcription activity.@*METHODS@#We used 5' rapid amplification of cDNA ends (RACE) analysis to identify the IPO8 transcription start site (TSS), and amplified series truncated 5' UTR fragment containing transcription start site. The PCR productions were inserted into luciferase report vector pGL3- Basic. After confirmation by restriction enzyme digestion, the recombinant plasmids were cotransfected into Saos-2 cells with plasmid pRL-TK. The luciferase activities were measured by dual luciferase reporter system.@*RESULTS@#The IPO8 gene transcription start site was established. The electrophoresis analysis of restriction enzyme digestion and DNA sequencing verified the fragments were successfully amplified and inserted into pGL3-Basic. After the recombinant plasmids transfected, the highexpressions of luciferase were detected in Saos-2 cells.@*CONCLUSION@#The recombinant vector containing IPO8 promoter is constructed successfully, which provides a foundation for determining expressional regulation of IPO8 in the further study.

Effects of rs35100176 polymorphism in IPO8 promoter on gene expression / 中国病理生理杂志

AIM:To investigate the effect of rs 35100176 CCT insertion/deletion polymorphism in the promoter region of importin 8 ( IPO8) gene on its mRNA expression .METHODS:A 342-bp fragment of IPO8 gene promoter con-taining the rs35100176 polymorphism was amplified from 49 DNA samples and sequenced .The IPO8 promoter fragments containing CCT 3-nucleotide insertion or deletion were amplified using the corresponding homozygote DNA samples .The PCR products were sequenced and inserted into the luciferase reporter vector pGL 3-Basic.Recombinant vectors were trans-fected into the cells by Fugene 6.0 and the expression of the reporter gene was detected by a dual-luciferase reporter assay system.The mRNA expression level of IPO8 was detected by real-time PCR in 3-nucleotide insertion or deletion homozygote cells.RESULTS:The sequencing results showed that there were 3 kinds of genotypes in the rs35100176 polymorphism, CCT/CCT, CCT/-and -/-, and the gene frequencies were 18.37%, 55.10% and 26.53%, respectively.The re-combinant expression vectors pGL 3-3N Insertion and pGL3-3N Deletion were successfully constructed .The luciferase assay showed that pGL3-3N Insertion produced significantly lower luciferase activity than that by pGL 3-3N Deletion.Real-time PCR showed that HEK293 cells with 3-nucleotide insertion homozygote expressed relative lower IPO 8 mRNA than Saos-2 cells with 3-nucleotide deletion homozygote .CONCLUSION: The CCT 3-nucleotide insertion variant decreases the pro-moter activity of IPO8, thus affecting the gene expression .

Cloning,transfer and anti-human breast cancer cell growth of the extracellular domain of cadherin 5 / 中国病理生理杂志

AIM:In order to study the effect of the extracellular domain of cadherin 5 on the growth of a human breast cancer cell line MDA-MB435.METHODS:Cadherin extracellular domain repeats 1 to 4(CED1-4)was cloned by using RT-PCR technique,and inserted into the plasmid vector pMSCV.pMSCV-CED1-4 was propagated in XL-blue strain of Escherichia coli,extracted and purified.CED1-4 was cut by restriction endonuclease,examined by using agar gel electrophoresis,and finally sequenced.CED1-4 gene was transferred into MDA-MB435 cell line.The expression of CED1-4 gene in MDA-MB435 cell was analyzed by methods of RT-PCR and Western blotting.The effect of CED1-4 on the growth of MDA-MB435 cell was observed by the methods of proliferation experiments in vitro and the experiments in nude mice in vivo.RESULTS:The recombinant vector pMSCV-CED1-4 was successfully constructed.CED1-4 band appeared between the 1 636 bp and 1 018 bp in agar gel electrophoresis.The sequence result showed that CED1-4 had 1 452 bp and codes 484 amino acids.PCR and Western blotting identified that CED1-4 mRNA and protein were expressed in the transfected MDA-MB435 cells.Cell proliferation experiments showed that the proliferation rate of MDA-MB435 cells was lower in the experimental group than that in the experimental control group and the blank control group.The mean volume and weight of tumors in nude mice were lower in the experimental group than those in the experimental control group and the blank control group.CONCLUSION:The growth of a human breast cancer cell line MDA-MB435 is inhibited in vitro and in vivo by cadherin 5 extracellular domain CED1-4.