[Construction of shRNA expression vector silencing Kir6.2 gene and to study its influence on the proliferation and invasion of HepG2 cells].

Objectives: To construct the expression vector pGenesil-3-shRNA that can express the short hairpin RNAs (shRNA) silencing Kir6.2 gene and to study its influence on the proliferation and invasion of HepG2 cells.

Methods: Two shRNA silencing Kir6.

[Analysis of presence and difference of sequence of porcine endogenous retrovirus in DNA genomes from peripheral blood white cells of pig and mRNA in tissues from mini-pigs].

The aim is to investigate biological features of porcine endogenous retrovirus (PERV) of pigs in China and to provide basic parameters for evaluation of biological safety of xenotransplantation from pig to human. In this study, basic biologic features of PERV of DNA of peripheral blood white cells of 12 species of domestic pigs in China were examined by polymerase chain reaction; Analysis of difference of PERV gene sequence was investigated by sliver-stained single stranded conformational polymorphism and restriction fragment length polymorphism; Difference of PERV mRNA from a variety of tissue of two species of mini-pig was analysized by reverse transcriptase-PCR and semi-quantitative analysis. These results showed that Sequences of PERV-A, -B genes are ubiquitous in DNA genome of peripheral blood white cells in the examined pigs; There was no single stranded conformational polymorphism in PERV-A, -B gene sequences.

[Studies on the infectivity by porcine endogenous retrovirus with porcine skin fibroblast in vitro and in vivo].

To understand the infectivity by porcine endogenous retrovirus with porcine skin fibroblast cell in vitro and in vivo, porcine skin fibroblast cell established by our laboratory were co-cultured with neo/HEK293 cell for the infection of PERV in vitro, and were subcutaneously transplantated to SCID (severe combined immuno-deficiency) mice for the infection of PERV in vivo, laying the foundation for valuation of biologic safety of xenotransplantation. The event of neo/HEK293 cells infected by PERV occurred during co-culture of porcine skin fibroblast cells with neo/HEK293 cells, expanding the rang of the infection of porcine endogenous retrovirus. After pig cells transplantated subcutaneously in SCID mice, the microchimerism (78.