Over the past four decades, efforts to improve the prognosis of pancreatic cancer have yielded limited progress, largely due to the complex genetic mutations, a desmoplastic tumor microenvironment, and the rapid metabolic rewiring that enables pancreatic cancer cells to adapt to cellular stress. Recent studies have demonstrated the critical reliance of pancreatic cancer cells on autophagy for survival, fitness, and the development of resistance to various clinical therapies. These findings position autophagy as a potential therapeutic vulnerability for the development of novel neoadjuvant treatments. However, conventional autophagy inhibition often leads to the accumulation of p62, which activates p62-dependent pathways that promote tumor growth and metastasis, thereby limiting the efficacy of autophagy-targeting therapies. In this study, we demonstrate that the atypical protein kinase C isoform zeta (PKCζ) plays a pivotal role in maintaining intracellular homeostasis in pancreatic ductal adenocarcinoma (PDAC) cells. Inhibition of PKCζ downregulates BCL-2-associated athanogene 3 (BAG3), reduces the expression of key autophagy-related proteins, autophagy related 5 (ATG5) and Beclin-1, and attenuates autophagic flux. Notably, PKCζ-mediated autophagy suppression does not result in p62 accumulation, circumventing the pro-tumorigenic effects associated with conventional autophagy inhibition. Furthermore, PKCζ inhibition enhances the anti-tumor efficacy of other chemotherapeutic agents, such as mitogen-activated protein kinase kinase (MEK) inhibitors, in PDAC. These findings identify PKCζ as a promising therapeutic target and provide a foundation for the development of innovative treatment strategies for pancreatic cancer.
Due to the anti-apoptotic effect employed by cells to protect themselves, recent research shows that photothermal therapy (PTT) can lead to heat shock response, thus reducing the effect of treatment on cancer cells. Small interfering RNA (siRNA), as an effective carrier of RNA interference, can silence the expression of heat shock protein, HSPs or BAG3 genes by inhibiting the expression of specific genes, and thereby inhibiting heat shock response and making cancer cells more sensitive to PTT. In this study, flower-like gold nanoparticles were used as a core for a layer-by-layer strategy to produce a safe and biodegradable nanoparticle platform for gene silencing and photothermal therapy. The results showed that when the mass ratio of the GNFs and siRNA was 20 : 1, the loading efficiency was above 90%, which can effectively silence the expression of BAG3 siRNA. We demonstrated that the GNFs–siRNA still had a good photothermal effect after siRNA modification. In vitro, the GNFs–siRNA showed good biocompatibility and effectively tumor killing properties after laser irradiation. Furthermore, the GNFs–siRNA with laser treatment significantly decreased the expression of BAG3 and remarkably inhibited tumor growth in vivo. This nanosystem establishes an optimized platform for future gene delivery and photothermal therapy.