Poly(beta-amino ester) nanoparticles enable tumor-specific TRAIL secretion and a bystander effect to treat liver cancer.

Despite initial promise, tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-based approaches to cancer treatment have yet to yield a clinically approved therapy, due to delivery challenges, a lack of potency, and drug resistance. To address these challenges, we have developed poly(beta-amino ester) (PBAE) nanoparticles (NPs), as well as an engineered cDNA sequence encoding a secretable TRAIL (sTRAIL) protein, to enable reprogramming of liver cancer cells to locally secrete TRAIL protein. We show that sTRAIL initiates apoptosis in transfected cells and has a bystander effect to non-transfected cells. To address TRAIL resistance, NP treatment is combined with histone deacetylase inhibitors, resulting in >80% TRAIL-mediated cell death in target cancer cells and significantly slowed xenograft tumor growth. This anti-cancer effect is specific to liver cancer cells, with up to 40-fold higher cell death in HepG2 cancer cells over human hepatocytes. By combining cancer-specific TRAIL NPs with small-molecule-sensitizing drugs, this strategy addresses multiple challenges associated with TRAIL therapy and offers a new potential approach for cancer treatment.