RESUMEN
Pancreatic cancer (PAC) is one of the most lethal malignant neoplasms with poor prognosis and high mortality. Emerging evidence has revealed that abnormal tumor lipid metabolism and tumor-associated macrophages (TAMs) significantly contribute to PAC development and progression. Therefore, concurrently reprogramming tumor lipid metabolism and regulating TAMs function could be a promising strategy for effective PAC therapy. Herein, we identified an important enzyme catabolizing lipids (monoacylglycerol lipase, MGLL) and a key receptor regulating macrophage phenotype (endocannabinoid receptor-2, CB-2) that are over-expressed in PAC cells and on TAMs, respectively. Based on this finding, we developed a reduction-responsive poly (disulfide amide) (PDSA)-based nanoplatform for systemic co-delivery of MGLL siRNA (siMGLL) and CB-2 siRNA (siCB-2). This nanoplatform could utilize its reduction-responsive characteristic to rapidly release siRNA for efficient silencing of MGLL and CB-2, inducing concurrent suppression of free fatty acids (FFAs) generation in PAC cells and repolarization of TAMs into tumor-inhibiting M1-like phenotype. With this suppressed FFAs generation to inhibit nutrient supply for tumor cells and repolarized TAMs to secrete tumoricidal cytokines such as TNF-α and IL-12, a combinational anticancer effect could be achieved in both xenograft and orthotopic PAC tumor models.
Asunto(s)
Metabolismo de los Lípidos , Neoplasias Pancreáticas , Humanos , Inmunoterapia , Macrófagos/metabolismo , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/terapia , Interferencia de ARN , Microambiente TumoralRESUMEN
Combination therapy has been developed as an innovative modality for effective cancer therapy. However, the administration of combinatorial therapeutics is limited by the varying pharmacokinetics of different drugs. Although numerous nanoparticles (NPs) can synchronize the delivery of combinatorial therapeutics to tumor cells, their clinical translation is still challenged, which is partly due to the complexity to precisely control the loading of combinatorial therapeutics to maximize therapeutic efficacy and suboptimal NP properties. Herein, a new redox-responsive polyprodrug nanoplatform was developed for targeted siRNA delivery and synergistic cancer therapy. This NP platform is made with redox-responsive 10-hydroxycamptothecin (HCPT)-based polyprodrug (polyHCPT) as the inner core, amphiphilic lipid-poly (ethylene glycol) (lipid-PEG) as the outer shell, and lactobionic acid (LA) decoration on the surface. After siRNA loading and subsequent systemic administration, the resulting NP platform could accumulate in tumor tissues and target hepatoma cells via specific recognition between LA and asialoglycoprotein (ASGP) receptors. With the high concentration of glutathione (GSH) in the cytoplasm to break the disulfide bonds in the polyHCPT, intact HCPT molecules and encapsulated B-cell lymphoma 2 (Bcl-2) siRNA (siBcl-2) could be rapidly released, leading to the synergistic inhibition of tumor growth via the induction of apoptosis by HCPT and the concurrent silencing of the anti-apoptotic gene by siBcl-2.