Inhibitory effect and its molecular mechanisms of MicroRNA-34a on human na-sopharyngeal carcinoma CNE-2 cell line subcutaneous xenograft tumor in nude mice / 中国免疫学杂志

ABSTRACT

Objective:To investigate the inhibitory effect and its possible molecular mechanisms of MicroRNA-34a(miR-34a) on the human nasopharyngeal carcinoma CNE-2 cell line subcutaneous xenograft tumor in nude mice.Methods: The human nasopharyngeal carcinoma CNE-2 cell line was cultured in vitro.miR-34a and Scrambled miRNA recombinant plasmids were successfully established and stably transfected into CNE-2 cells.Fifteen six-week-old male nude mice were divided randomly into three groupsmiR-34a group(5 mice) ,Scrambled miRNA group(5 mice) ,Blank control group(5 mice).Different CNE-2 cells were subcuta-neously injected on the back near right lower limb.Tumor volumes were examined every 7 days.Mice were executed on the 35 days,and the eventual average tumor volumes and weights were examined.Total RNA and protein were isolated from tumors,and the expression of miR-34a,CDK6,and Bcl-2 mRNA and protein were determined by qRT-PCR and western blot,respectively.Results: The relative expressions of miR-34a was significantly up-regulated in miR-34a transfected group compared to Scrambled miRNA transfected group (P (849.62±101.32) mm3 ,respectively,and the eventual average tumor weights in miR-34a group,Scrambled miRNA group and blank control group were(0.81±0.13)g,(1.47±0.21)g and(1.58±0.37)g,respectively.Both the eventual average tumor volumes and weights in miR-34a group were lower compared to the other two groups(P<0.05).qRT-PCR results revealed that the expression of miR-34a in miR-34a transfected group was significantly higher than in the other two groups,while the mRNA and protein expression of CDK6 and Bcl-2 were lower than the other two groups ( P<0.05 ) .Conclusion: miR-34a may inhibit the growth of human nasopharyngeal carcinoma CNE-2 cell line subcutaneous xenograft tumor in nude mice by down-regulating CDK6 and Bcl-2.