Polymer Nanoparticles Overcome Drug Resistance by a Dual-Targeting Apoptotic Signaling Pathway in Breast Cancer.

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) activating therapy has received wide attention due to its capacity to precisely induce cancer cell apoptosis. However, drug resistance and the poor pharmacokinetic properties of TRAIL protein are obstacles in TRAIL-based therapy for cancer. Herein, a strategy is developed to remotely control and specifically initiate TRAIL-mediated apoptotic signaling to promote TRAIL-resistant cancer cell apoptosis using near-infrared (NIR) light-absorbing conjugated polymer nanoparticles (CPNs). Upon 808 nm laser excitation, the promoter 70 kilodalton heat shock protein (HSP70) initiates transcription of the TRAIL gene in response to heat shock, thereby expressing TRAIL protein in breast cancer cells, which activates the TRAIL-mediated apoptosis signaling pathway. Simultaneously, the CPNs locally release W-7, which targets calmodulin (CaM) and further promotes caspase-8 cleavage and enhances cancer cell apoptosis. Both in vitro and in vivo results demonstrate that CPNs/W-7/pTRAIL produces an excellent synergistic therapeutic effect on breast cancer upon near-infrared light with low toxicity. Therefore, this work provides a strategy for overcoming drug resistance through dual-targeting TRAIL-mediated apoptotic signaling in breast cancer.