Mechanistic Insights into the Action of Histamine-Functionalized PLA Nanoparticles Loaded with 5-Fluorouracil Against Gastric Cancer Cells In Vitro

Gastric cancer is among the leading causes of cancer-related deaths worldwide. Modern treatment approaches include nanoparticles (NPs) designed to target cancer cells, which release a therapeutic cargo facilitating the inhibition of their expansion, thereby improving anti-tumor therapies. The success of NPs, created to deliver anticancer agents and biologically active compounds, may depend on selecting the way to target cancer cells. This study focused on examining the effects of NPs made of polylactic acid (PLA) with histamine (His) end groups and loaded with 5-fluorouracil (5-FU), a known anticancer drug (PLA-His-5-FU), on human gastric cancer AGS cells in vitro. The incubation of AGS cells with PLA-His-FU NPs resulted in diminished mitochondrial membrane potential and the induction of cell apoptosis, along with cell cycle arrest and the reduction of cell proliferation. Furthermore, the NPs tested provoked the secretion of pro-inflammatory cytokines tumor necrosis factor alpha (TNF-α) and interleukin (IL)-1β by AGS cells and induced the activation of the nuclear factor kappa B (NF-κB) signaling pathway in THP-1 blue monocytes, which indicates the ability to promote the development of a milieu for the infiltration and activation of immunocompetent cells. NPs did not increase intracellular adhesion molecule (ICAM-1) deposition on AGS cells, thus potentially preventing the distribution of cancer cells. In conclusion, PLA-His-5-FU NPs show promising anticancer activity for gastric cancer AGS cells in vitro, better than PLA-OH-5-FU, and can be used in further in vivo studies to confirm this activity.