[Discussion on Regulatory Risk of in Vitro Diagnostic Reagents in Use].

According to the information of the supervision and inspection of in vitro diagnostic reagents for clinical use, this article analyzed the compliance issues and discussed the methods to solve the problems, to urge medical institutions to reduce the regulatory risk of in vitro diagnostic reagents in use.

[Arresting effect of p16 and dll4 transfection on cell cycle of K562 cells].

This study was purposed to investigate the expression and role of eukaryotic expression vector containing p16, dll4 genes in leukemia K562 cells. A vector pBudCE4.1-16-dll4 containing wild type p16cDNA and dll4cDNA was designed and constructed, then this vector was transfected into leukemia K562 cells by using lipofectamine 2000. The expression of p16 and dll4 genes was detected by Western blot, the cell growth curve and cell cycle were determined by CCK-8 kit and flow cytometry respectively. The results showed that the recombinant plasmid pBudCE4.1-16-dll4 was constructed and transfected into K562 cells in vitro successfully. The expression of exogenous P16 and Dll4 proteins could be detected in K562 cells. After transfection for 48 hours, the K562 cells were arrested in G(1) phase, the cell count increased in G(0)/G(1) phase and reduced in S phase, the cell proliferation decreased as compared with control. It is concluded that the p16 and dll4 genes can simultaneously express in K562 cells transfected with recombinant plasmid pBudCE4.1-16-dll4 in vitro which results in G(0)/G(1) arrest and reduces cell proliferation.

[Inhibitory effect of p16, p53 transfection on leukemic cell lines K562 and HL-60].

This study was purposed to construct a vector containing human suppressor gene p53 and p16, and to investigate their expression and effect on K562 and HL-60 cells. pBudCE4.1-53-16 is a vector designed for simultaneous expression of human suppressor gene p53 and p16 in mammalian cell line. After transfection into K562 cells with lipofectamine(TM) 2000, the expression of p53 and p16 genes was detected by Western blot and immunocytochemical method. The growth curve, apoptosis, cell cycle were assayed by CCK-8 and flow cytometry. The results showed that the recombinant plasmid pBudCE4.1-53-16 was constructed successfully and were verified by PCR and restriction analysis. The expression of P53 and P16 protein could be detected after transfection into leukemia cells (K562 and HL-60) for 48 hours. As compared with control group, the cell proliferation in experimental group was inhibited, the cells were arrested in G0 phase and apoptotic cells increased (p<0.001). It is concluded that the recombinant plasmid pBudCE4.1-53-16 has been established. p16 and p53 in the recombinant plasmid pBudCE4.1-53-16 synchronously express in leukemic cells after transfection in vitro for 2 days and results in reduced proliferation, G0 arrest and apoptosis increase.