[Anti-tumor effects of recombinant adenovirus encoding survivin encapsulated in cationic liposome]

To explore the anti-tumor effects and mechanisms of recombinant adenovirus encoding survivin encapsulated in cationic liposome.

CT26 tumor model was established in BALB/c mice. Fifty mice were randomly divided into five groups, including the group treated with recombinant adenovirus encoding survivin encapsulated in cationic liposome (Lip+ Ad-sur), the group of recombinant adenovirus encoding survivin (Ad-sur), the group of recombinant adenovirus encoding null encapsulated in cationic liposome (Lip+Ad-null), the group of liposome (Lip), and the group of PBS alone (PBS). Survival rate of mice, tumor volume, and side effects of treatments were observed. Lymphocytes were activated by adenovirus vaccine to kill tumor cells in vitro and in vivo. CTL assay and histological examination were carried out.

Immunotherapy with recombinant adenovirus encoding survivin encapsulated in cationic liposome was effective for inducing protective and therapeutic anti-tumor immunity in CT26 tumor model. In the combination therapy group, the tumor growth was inhibited and the tumor volume was significantly smaller when compared with the controls. The survival rate of mice in the combination therapy group at 7 weeks after inoculation of tumor cells was significantly higher than that of the control group. Histologically, the tumor tissue was markedly necrotic and was infiltrated by lymphocytes. 51Cr assay in vitro indicated that the combination therapy group showed higher specific killing activity against CT26 tumor cells than did the control groups, and the T cells were independent of NK cells.

Immunotherapy with recombinant adenovirus encoding survivin encapsulated in cationic liposome was noted to have a significant anti-tumor effect on CT26 tumor model.