Speciifc targeted-intervention effect of CXCR 7-shRNA mediated by low viral carrier plus Rhizoma Paridis total saponin on tumor cells:an experimental study / 中国生化药物杂志

ABSTRACT

Objective To investigate the CXCR 7 protein expression when CXCR 7-shRNA transfected into human gastric cancer cell which mediated with lentivirus vector combined with Rhizoma Paridis Total Saponin. Methods Three shRNA sequences of CXCR 7 and one negative control sequence were designed and synthesized, and recombinant lentiviral vectors with pSilencerTM 4.1 system were established. Transfection of HEK 293 T cells and packaging viral were finished and the titers were detected. Transfection of all recombinant lentiviral vectors and negative control vector were finished and expression of CXCR 7 mRNA were detected by RT-PCR method. Silence efficiency in groups were determined and the expression vector with highest silence efficiency was selected for next experiments. To detect the effect of SGC 7901 cell proliferation by CXCR 7-shRNA transfection and combined with Rhizoma Paridis Total Saponin intervention with MTT. To detect the effect of SGC 7901 cell expression of protein by CXCR 7-shRNA transfection and combined with Rhizoma Paridis Total Saponin intervention with Western blot. Results The packaging of three lentiviral vector and negative control sequence are successful which is confirmed by gene sequencing and the titer are 4.9×108 pfu/mL, 3.6×108 pfu/mL, 5.2×108 pfu/mL, 2.0×108 pfu/mL respective. The expression quantity of CXCR 7 mRNA in positive groups are lower than negative control group(P<0.05)and inhibition ratio to CXCR 7 in CXCR 7-shRNA-1 and combined with Rhizoma Paridis Total Saponin intervention group is higher than the other two groups(P<0.05). The proliferation level of tumour cell is significant reduction after CXCR 7-shRNA-1 transfection and have a significant difference comparing to the group without transfection(P<0.05). The expression of CXCR 7 protein is significant reduction after CXCR 7-shRNA-1 transfection comparing to the group without virus vector and negative control group and have a significant difference(P<0.05). Conclusion The construction of three CXCR 7-shRNA lentiviral expression vector are successful and expression level of protein and CXCR 7 mRNA are down-regulated effectively after transfection and combined with Rhizoma Paridis Total Saponin intervention. It maybe means that CXCR 7 gene takes an important role in the process of gastric cancer proliferation and invasion.This is foundation for further study of gastric cancer gene therapy using CXCR 7/CXCL 12 biological axis as a target.