Abstract

Yan Yin1, Qing-Xiao Wang1, Xu Chen1, Jing Xing1, Yan-Rong Fan2, Zhi-Wei Wu3, Jian-Jun Wang1* and Gen-Xing Xu3,4

As a domestic anaerobic bacterium in the human body, Bifidobacterium longumcan selectively germinate and proliferate in the hypoxic regions of solid tumors. Selenium (Se) has been found to inhibit carcinogenesis and tumor growth. In our previous study, we demonstrate that B. longumcarrying pBV22210-Endostatin (B. longum-En) inhibit tumor growth. In this study, we enriched Se to B.longum-En (Se-B. longum-En) to evaluate the antitumor efficacy when delivered orally or intravenouslyon H22 tumor-bearing mice and examined the distribution of Se in vivo. The results showed that Se-B.longum-En could significantly inhibit tumor growth as well as extend the median survival time of tumor-bearing mice. The concentration-time curve suggested that Se could be absorbed and disseminated rapidly in vivo. The results also showed that there wasa dose-effect relationship between Se and tumor inhibition rate and the antitumor effect was more pronounced when Se-B. longum-Enwas delivered via vein than by oral route. Based on the results, B. longumcarrying endostatin gene and enriched with Se may be a potential agent in cancer gene therapy