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RNA polymerase III is an essential enzyme in eukaryotes for synthesis of tRNA, 5S rRNA, and other small nuclear and cytoplasmic RNAs. Thus, RNA polymerase III promoters are often used in small hairpin RNA (shRNA) expression. In this study, the porcine H1, U6, and 7SK RNA polymerase III type promoters were cloned into a pcDNA3.1(+) expression vector containing a shRNA sequence targeting enhanced green fluorescent protein (EGFP). PK and DF-1 cells were cotransfected with the construction of recombinant interference expression vector and the EGFP expression vector, pEGFP-N1. The average fluorescence intensity of EGFP in transfected cells was measured by fluorescence microscopy and flow cytometry. Real-time PCR was used to detect expressed shRNAs and the relative expression of EGFP, to confirm the activity of the promoters. The results showed that the activity of porcine 7SK promoter is stronger than the U6 promoter, which is in turn stronger than porcine H1. While the high levels of expression of the U6 and 7SK promoters saturate the shRNAs level in the host cell, which can cause cytotoxicity and tissue damage. Therefore, porcine H1 promoter is effective for expression of shRNA, and may be an excellent tool to knockdown gene expression in pigs for functional genomics studies. The results also lay a foundation for the development of porcine RNAi technology and genetically modified porcine research. [ABSTRACT FROM AUTHOR]

We aimed to elucidate whether serum VEGFR2 concentration before and after transarterial chemoembolization (TACE) can predict survival in patients with unresectable hepatocellular carcinoma (HCC). Serum VEGFR2 concentrations were serially measured in 169 patients with advanced HCC before and after TACE. We defined a decrease in the serum VEGFR2 level >10 % from the pretreatment level as response. Serum VEGFR2 concentrations decreased in 44 (26.0 %) patients at week 4. Patients who had a VEGFR2 response at week 4 had a longer median survival than those who did not have a VEGFR2 decrease (19.0 vs. 9.8 months, p < 0.001). Clinical variables associated with OS in addition to VEGFR2 response also included extrahepatic metastases ( p = 0.005) and vascular invasion ( p = 0.035). VEGFR2 decrease after TACE ( p = 0.012) and presence of extrahepatic metastases ( p = 0.02) were independently associated with OS by multivariate analysis. A serum VEGFR2 concentration decrease at 4 weeks after TACE may predict favorable overall survival in patients with advanced HCC. [ABSTRACT FROM AUTHOR]

No effective vaccine has been developed against the subgroup J avian leukosis virus (ALV-J). The genetic diversity of ALV-J might be related to the env gene, therefore, we selected conserved sequences of the env gene and designed interference sequence. In this study, microRNAs (miRNAs) were designed and synthesized, corresponding to conserved regions of the env gene. These miRNAs were cloned into the linearized eukaryotic expression vector. The recombinant plasmids were transfected into DF-1 cells. After transfection, the cells were inoculated with ALV-J. In reporter assays, the transfection efficiency is 80 % by indirect immunofluorescence (IFA). Expression of the virus envelope glycoprotein was measured by IFA and western blotting assays. The relative expression of env gene was determined using quantitative PCR. Our results show that the mi- env 231 and mi- env 1384 could effectively suppress the replication of ALV-J with an efficiency of 68.7-75.2 %. These data suggest that the miRNAs targeting the env can inhibit replication of ALV-J efficiently. This finding provides evidence that miRNAs could be used as a potential tool against ALV infection. [ABSTRACT FROM AUTHOR]