A self-sustained nanoplatform reverses TRAIL-resistance of pancreatic cancer through coactivating of exogenous and endogenous apoptotic pathway.

Since the 5-year survival rate of pancreatic cancer is only 10.0%, new therapies are urgently needed. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) induces apoptosis specifically on tumor cells, nevertheless its clinical application was seriously restricted by resistance and short in vivo half-life. Herein, a novel multifunctional R6ST protein equipped with cell penetrating peptides R6, intrinsic apoptosis inducing tetrapeptide AVPI and soluble TRAIL was designed and constructed. Then, it was recruited to prepare self-sustained nanoplatform (SSN) to reverse TRAIL-resistance of pancreatic cancer through simultaneously promoting extrinsic and intrinsic apoptotic pathway, as well to elongate circulation time. Once administrated, high tumor accumulation and cellular uptake of SSN were achieved through prolonged circulation time, targeting ability of soluble TRAIL to death receptors and positive-charged R6, and further enhanced through reversed upregulation of death receptors on TRAIL-resistant tumor cells by the cumulated artesunate released in cytoplasm as a positive feedback loop. Furthermore, this loop simultaneously promoted extrinsic apoptosis of TRAIL fragment via the upregulated death receptors on TRAIL-resistant pancreatic cancer cells and intrinsic apoptosis of AVPI tetrapeptide via the efficient accumulation and uptake of R6ST on SSN. Hence, SSN exhibited synergistic antitumor effect and provided a new strategy for TRAIL-resistant pancreatic cancer therapy.