【Objective】 To investigate the treatment efficiency and mechanism of recombinant adenovirus encoding LRIG1 gene driven by survivin promoter in nude mice heterotransplanted models of human bladder cancer. 【Methods】 Heterotransplanted models of human bladder cancer cell line BIU87 cells in nude mice were established. The mice were randomly divided into 3 groups during the experiment: Ad-Surp-LRIGl group received viral supernatant solution of Ad-Surp-LRIGl by tail vein injection

Ad-LRIG group received viral supernatant solution of Ad-LRIG by tail vein injection

and PBS group received phosphate buffer solution (PBS). The growth of tumors was observed and the growth curve was mapped. The expression of LRIG1 and EGFR were examined by reverse transcription PCR (RT-PCR) and Western blot. 【Results】 The tumor growth rate in Ad-Surp-LRIGl group was slower than that in the other two groups. The tumor quality in Ad-Surp-LRIGl was lighter than that in the other two groups

the differences were statistically significant (F = 97.86

P = 0.00)

the quality difference in Ad-LRIGl group and PBS group was not statistically significant difference (t = 1.73

P = 0.06). Compared with Ad-LRIGl group and PBS group

the expression of mRNA and protein of LRIG1 was obviously up-regulated and that of EGFR was down-regulated in Ad-Surp-LRIGl group(P < 0.01). 【Conclusions】 The recombinant adenoviral vector of Ad-Surp-LRIGl could inhibit significantly the growth of bladder cancer in vivo

the mechanism may be partly LRIG1 can downgrade the expression of EGFR.