Abstract: AIM: To construct the recombinant adenovirus containing human plasminogen Kringle 5 (K5)gene, then observe the secreted expression and effect of K5 protein on TC-1 tumors. METHODS: We cloned K5 gene into the genome of replication-defective adenovirus by virus recombination technology;the K5 RNA expression was evaluated by RT-PCR;the K5 protein secreted expression was determined by Immunoprecipitation andWestern blotting;the effect of K5 was observed in xenograft lung cancr mice model;and the tumor microvascular density (MVD)was counted. RESULTS: The recombined adenovirus Ad-EF1α-K5 was constructed successfully and was expressing in the levels of both mRNA and protein.In the mice lung cancer xenograft model, the recombinant adenovirus can delay the growth of established TC-1 tumors and decrease the MVD. CONCLUSION: Recombinant adenovirus vectors Ad-EF1α-K5 can efficiently express protein K5 and inhibit tumor growth in the mice lung cancer xenograft model.The effect may related to inhibitory effect on angiogenesis.

Key words: adenovirus, Kringle 5, angiogenesis, TC-1