Enhancing Radiotherapy Sensitivity in Prostate Cancer with Lentinan-Functionalized Selenium Nanoparticles: Mechanistic Insights and Therapeutic Potential.

Radiation therapy is a cornerstone of prostate cancer (PCa) treatment. However, its limited tumor sensitivity and severe side effects restrict its clinical utility. Lentinan-functionalized selenium nanoparticles (LET-SeNPs) have shown promise in enhancing radiotherapy sensitivity and exhibiting antitumor activity. In this study, we investigated the radiotherapy sensitization mechanism of LET-SeNPs in PCa. Our results demonstrate that the combination of LET-SeNPs and X-ray therapy (4 Gy) significantly inhibited the growth and colony formation of PCa cells by inducing apoptosis, surpassing the effects of individual treatments. This combined approach modulated DNA damage through the p53, MAPK (mitogen-activated protein kinase), and AKT pathways. Furthermore, LET-SeNPs increased PC3 cell sensitivity to X-ray-induced apoptosis by downregulating TrxR (Thioredoxin reductase) expression and inducing reactive oxygen species (ROS) overproduction, thereby activating mitochondria-mediated apoptosis signaling pathways. Additionally, LET-SeNPs regulated PARP (poly (ADP-ribose) polymerase) to prevent DNA damage repair. In vivo studies confirmed that the combination treatment inhibited PCa growth by synergistically activating the p53 pathway to induce cell apoptosis. These findings highlight LET-SeNPs' potential as a radiotherapy sensitizer and suggest that combining LET-SeNPs with X-ray therapy could be a promising strategy for clinical application, leveraging selenium-modified nanoparticles' antitumor effects.