Inhibitory effect of STAT3 antisense oligodeoxynucleotide against human adenocarcinoma of lung derived from A549 cell in nude mice

Abstract

Objective To investigate the inhibitory effects of antisense oligodeoxynucleotide( ASODN) of signal transducer andactivator of transcription 3 ( STAT3) on development and growth of transplanted lung A549 cell adenocarcinoma in nude mice. MethodsThe inhibitory effects of STAT3 ASODN on A549 cell growth was evaluated by CCK-8 assay. STAT3 ASODN-treated A549 cells wereimplanted subcutaneously into nude mice; the tumor growth was observed and the tumor-forming rate was calculated. After subcutaneousimplantation of the untreated A549 cells,the tumor-bearing mice were randomized into 3 groups: control group,STAT3 ASODN group,and nonsense oligodeoxynucleotide ( NSODN) group,with normal saline,STAT3 ASODN,and STAT3 NSODN injected intatumorally ( 15mg/kg daily for 3 weeks) . The tumor volumes were measured every other day and the tumor weights were determined. The proteinexpressions of STAT3 and p-STAT3 in xenografts were examined by Western blotting analysis. Results STAT3 ASODN significantlyinhibited the growth of A549 cells compared with STAT3 NSODN group ( P 0. 05) . The tumor formation ability of A549 cells treated withSTAT3 ASODN was significantly decreased ( with the tumor inhibitory rate being 75. 8% ) . Moreover,the growth of transplanted tumorwas also significantly inhibited in STAT3 ASODN group as compared with those in NSODN group and control group ( P 0. 05) . Thetumor weights were significantly reduced in STAT3 ASODN group than in STAT3 NSODN group and control group ( with the tumorinhibitory rate being 51. 1% ) . The expression of STAT3 protein and p-STAT3 was also down-regulated in STAT3 ASODN group.Conclusion STAT3 ASODN can suppress the tumorigenic ability of A549 cells and inhibit the growth of transplanted tumor in nudemice.