Abstract:

bstract:Objective
To investigate the inhibitory effect of constitutive  photomorphogenic homolog subunit 3 of COP9(COPS3) gene interferred by RNA on

the proliferation of lung cancer A549 cells, and to clarify its mechanism. Methods   The tumor experimental models of nude mice

were established in lung cancer  cell line A549.40 nude mice were divided into experiment group (n=20,implanted with A549 cells

infected by si-COPS3) and  control group(n=20,implanted with A549 cells infected by si-CTRL.The tumor size,weight, and tumor

formation rate of the nude mice  were detected.The expression levels of the cell cycle related proteins,such as

P21,CDK2,CDK4,cyclinB1, and cyclinD1 were detected by Western blotting method after down-regulation of expresion of COPS3 gene in

A549 cells. Results The tumor volume and weight（P<0.05）,and  the tumor formation rate  of nude mice in experiment group were

significantly lower  than those in  control group.Compared with control group,the expression level of P21 protein was up-regulated

（P<0.05）,and the expression levels  of CDK4 and cyclinB1 protein were  down-regulated（P<0.05）,while the expression levels of

CDK2 and cyclinD1 protein had no significant changes（P=0.384,P=0.605）.Conclusion The proliferation  of lung cancer cells can be

suppressed significantly by inhibiting the  expression of COPS3 gene.This effect may be mediated by up-regulating the expression of

P21 and down-regulating the expressions of cyclinB1 and CDK4.

Key words: constitutive , photomorphogenic homolog subunit 3 of COP9;RNA interference;lung neoplasms;lentivirus vector