Lentivirus-Based Virus-Like Particles Mediate Delivery of Caspase 8 into Breast Cancer Cells and Inhibit Tumor Growth.

OBJECTIVE: Apoptosis plays an important role in both carcinogenesis and cancer treatment. Drugs or treatment strategies that can restore the apoptotic signaling pathways have the potential to eliminate cancer. Caspase 8 (CASP8) plays a vital role in the propagation of an enzymatic cascade that results in cell apoptosis.

METHODS AND RESULTS: In this study, the authors investigated the inhibitory effects of a HIV Gag virus-like particles (VLPs) that are incorporated with an active CASP8 (Gag-CASP8-VLPs) on the growth of breast cancer. Their data have shown that Gag-CASP8-VLPs, pseudotyped by the stomatitis virus G protein (VSV-G), can efficiently enter and deliver active CASP8 into breast cancer cells, leading to massive cell apoptosis and death. Interestingly, an injection of Gag-CASP8-VLPs in the tumor tissues of a 4T1 mouse breast cancer model can effectively inhibit tumor growth, and the earlier the Gag-CASP8-VLPs is administered, the more profoundly the tumor growth is inhibited.

CONCLUSIONS: Overall, Gag-CASP8-VLPs can deliver CASP8 into breast cancer cells, induce cell apoptosis, and inhibit tumor growth.