ABSTRACT
Objective To construct a human renal epithelial cell line HEK293T by CRISPR-Cas9-based site-directed knock-in of vascular endothelial growth factor 165 (VEGF165) gene, and avoid the off-target effect caused by lentivirus infection. Methods The VEGF165 expression vector with homologous arm (pUCm-T-VEGF165 plasmid) and the sgRNA expression vector [pSpCas9(BB)-2A-Puro-sgRNA plasmid] were designed and constructed based on the DNA sequence of the EZH2 gene, and then co-transfected into HEK293T cells. The expression of VEGF165 mRNA was detected by qPCR and the expressions of VEGF165 proteins were detected by Western Blot. Results The qPCR and Western Blot results showed that, comparing with the control, the pUCm-T-VEGF165 plasmid and pSpCas9(BB)-2A-Puro-sgRNA plasmid, the expression of the co-transfection plasmid were significantly increased, i.e. 3.42±0.30 vs. 1.02±0.21, 1.13±0.16 and 0.98±0.18 for the VEGF165 mRNA level (all P<0.01), and 1.13±0.16 vs. 1.02±0.06, 0.88±0.03 and 0.80±0.05 for the VEGF165 protein level (all P<0.01), respectively. Besides, the expression of EZH2 was significantly down-regulated, i.e. 0.14±0.06 vs. 1.08±0.11, 1.02±0.12 and 1.13±0.16 for the EZH2 mRNA level (all P<0.01), and 0.23±0.03 vs. 1.05±0.13, 0.91±0.04 and 0.81±0.06 for the EZH2 protein level (all P<0.01), respectively. This result showed that the VEGF165 was successfully inserted into the EZH2 genome, interfering the EZH2 expression. Conclusions VEGF165 gene can be successfully knocked into HEK293T cells by CRISPR/Cas9 system.
ABSTRACT
Objective To construct rat lysine-specific histone demethylase 1 (LSD1) overexpression plasmids and LSD 1 demethylation fragment disfunction plasmids,and to evaluate their expression levels in HEK293T cells.Methods LSD1 fragments were amplified by PCR,and LSD1 demethylation disfunction fragments were amplified by overlap PCR.Rat-specific LSD1 overexpression plasmids and LSD1 demethylation disfunction plasmids were constructed and verified by agarose gel electrophoresis and sequencing.HEK293T cells were infected using the validated recombinant plasmids and blank vectors,and the stably expressed cells were selected by puromycin.The expression of LSD1 in the stably expressed HEK293T was detected by Western Blot and real-time quantitative PCR.Results The results of agarose gel electrophoresis and sequencing showed that LSD1 overexpression plasmids and LSD1 demethylation disfunction plasmids were successfully constructed.The Western Blot and real-time quantitative PCR results showed that compared with the blank group,the relative expression of LSD1 and mRNA in the LSD1 overexpression group and the LSD1 demethylation disfunction group were up-regulated,and the differences were statistically significant(all P＜0.01).Conclusions The constructed LSD1 overexpression plasmids and LSD1 demethylationi disfunction plasmids can achieve overexpression of LSD1 gene in HEK293T cells.This paper lays a foundation for further study of the relationship between LSD 1 gene and related diseases and demethylation of LSD 1.