Ojective: To investigate the effect of hammerhead ribozyme that specifically cleaves c-myc mRNA on the proliferation of vascular smooth muscle cells (VSMCs ). Methods: Based on the computer analysis of the secondary s...Ojective: To investigate the effect of hammerhead ribozyme that specifically cleaves c-myc mRNA on the proliferation of vascular smooth muscle cells (VSMCs ). Methods: Based on the computer analysis of the secondary structure of c-myc mRNA, nt 2029 in rat c-myc oncogene was selected as a cleaving site for hammerhead ribozyme and the ribozyme was designed. With automatic DNA synthesizer, the two complementary DNA strands of the ribozyme were synthesized. The ribozyme gene was cloned into pGEM3Zf ( + ) vector and subcloned into eukaryotic expression pcD-NA3 vector. The recombinant pcDNA-Rz was transfected into the cultured rat VSMCs by lipofectAMINE mediated DNA transfection protocol and individual cell clones were selected by G418. Results: The sequence of ribozyme gene inserted in pGEMSZf ( + ) vector was proved to be perfectly correct. In VSMCs transfected with recombinant pcDNA-Rz, flow cytometry analysis showed that the S phase and G2/M fractions were decreased significantly and cell proliferation stagnated in the G0/G1 phase. Conclusion: The results suggest that hammerhead ribozyme that specifically cleaves c-myc mRNA can significantly inhibit the proliferation of VSMCs.展开更多
Induced pluripotent stem （iPS） cells were originally generated from mouse fibroblasts by enforced expression of Yamanaka factors （Oct3/4, Sox2, Klf4, and c-Myc）. The technique was quickly re- produced with human f...Induced pluripotent stem （iPS） cells were originally generated from mouse fibroblasts by enforced expression of Yamanaka factors （Oct3/4, Sox2, Klf4, and c-Myc）. The technique was quickly re- produced with human fibroblasts or mesenchymal stem cells. Although having been showed therapeutic po- tential in animal models of sickle ceil anemia and Parkinson＇s disease, iPS cells generated by viral methods do not suit all the clinical applications. Various non-viral methods have appeared in recent years for application of iPS cells in cell transplantation therapy. These methods mainly include DNA vector-based approaches, transfection of mRNA, and transduction of reprogramming proteins. This review summarized these non-viral methods and compare the advantages, disadvantages, efficiency, and safety of these methods.展开更多
基金Supported by the National Natural Science Foundation of China(No.39600064)
文摘Ojective: To investigate the effect of hammerhead ribozyme that specifically cleaves c-myc mRNA on the proliferation of vascular smooth muscle cells (VSMCs ). Methods: Based on the computer analysis of the secondary structure of c-myc mRNA, nt 2029 in rat c-myc oncogene was selected as a cleaving site for hammerhead ribozyme and the ribozyme was designed. With automatic DNA synthesizer, the two complementary DNA strands of the ribozyme were synthesized. The ribozyme gene was cloned into pGEM3Zf ( + ) vector and subcloned into eukaryotic expression pcD-NA3 vector. The recombinant pcDNA-Rz was transfected into the cultured rat VSMCs by lipofectAMINE mediated DNA transfection protocol and individual cell clones were selected by G418. Results: The sequence of ribozyme gene inserted in pGEMSZf ( + ) vector was proved to be perfectly correct. In VSMCs transfected with recombinant pcDNA-Rz, flow cytometry analysis showed that the S phase and G2/M fractions were decreased significantly and cell proliferation stagnated in the G0/G1 phase. Conclusion: The results suggest that hammerhead ribozyme that specifically cleaves c-myc mRNA can significantly inhibit the proliferation of VSMCs.
文摘Induced pluripotent stem （iPS） cells were originally generated from mouse fibroblasts by enforced expression of Yamanaka factors （Oct3/4, Sox2, Klf4, and c-Myc）. The technique was quickly re- produced with human fibroblasts or mesenchymal stem cells. Although having been showed therapeutic po- tential in animal models of sickle ceil anemia and Parkinson＇s disease, iPS cells generated by viral methods do not suit all the clinical applications. Various non-viral methods have appeared in recent years for application of iPS cells in cell transplantation therapy. These methods mainly include DNA vector-based approaches, transfection of mRNA, and transduction of reprogramming proteins. This review summarized these non-viral methods and compare the advantages, disadvantages, efficiency, and safety of these methods.
