The integration of
viral DNA into the host genome is mediated by viral
integrase, resulting in the accumulation of double-strand breaks.
Integrase-derived
peptides (INS and INR) increase the number of integration events, leading to escalated
genomic instability that induces apoptosis. CD24 is a
surface protein expressed mostly in
cancer cells and is very rarely found in normal cells. Here, we propose a novel targeted
cancer therapeutic platform based on the lentiviral
integrase, stimulated by
integrase-derived
peptides, that are specifically delivered to cancerous cells via
CD24 antigen-antibody targeting. INS and INR were synthesized and humanized and anti-CD24
antibodies were fused to the lentivirus envelope. The activity, permeability, stability, solubility, and toxicity of these components were analyzed. Cell death was measured by fluorescent microscopy and enzymatic assays and potency were tested in vitro and in vivo. Lentivirus particles, containing non-functional
DNA led to massive cell death (40-70%).
Raltegravir, an antiretroviral drug, inhibited the induction of apoptosis. In vivo, single and repeated administrations of INS/INR were well tolerated without any adverse effects.
Tumor development in nude mice was significantly inhibited (by 50%) as compared to the vehicle arm. In summary, a novel and generic therapeutic platform for selective
cancer cell eradication with excellent efficacy and safety are presented.