Development of 3D spheroids of AGS gastric cancer cells in vitro for exploration of H. pylori influence on tumor environment and anti-cancer activity of PLA-His-DOX nanoparticles.

INTRODUCTION: Gastric cancer (GC) is a complex disease, which may have infectious origin. Helicobacter pylori (H. pylori) Gram-negative bacteria are linked with GC development. There is growing interest in nanotechnology to develop therapeutic solutions for the treatment of GC in situ. The predictive assessment of nanomedicine efficacy in GC remains limited due to the lack of physiologically relevant models that capture tumor architecture and infection-driven reprogramming of gastric environment. METHODS: The aim of this study was to develop 3D culture of GC cell spheroids to assess the impact of selected H. pylori components toward this microenvironment. A further goal was to develop polylactic (PLA) nanoparticles (NPs) loaded with anti-cancer drug doxorubicin (DOX) and modified with histamine (His) to improve cellular penetration of the studied NPs and test effectiveness of developed formulation in 3D spheroidal model. RESULTS AND DISSCUSION: It has been shown that H. pylori components, cytotoxin associated gene A (CagA) protein and lipopolysaccharide (LPS) influenced spheroid architecture particularly by enlarging rim zone. PLA-His-DOX NPs induced cytotoxicity of spheroidal GC cells through oxidative stress amplification, DNA damage, and apoptosis. Treatment of GC spheroids with PLA-His-DOX reduced production of pro-inflammatory interleukin (IL) IL-1β and IL-8 driven by H. pylori soluble components, indicating a combined cytotoxic and anti-inflammatory mechanism of PLA-His-DOX. In vivo study using Cavia porcellus confirmed short-term tolerability of the studied unloaded carrier (PLA-His-NPs) under tested conditions with no detectable organ toxicity. In summary, 3D spheroids of AGS GC cells developed in this study in vitro consist of predictive models that link tumor biology with infectious components and facilitate the assessment of anti-GC cell effects of PLA-His-DOX NPs. Soluble H. pylori CagA and LPS, which in vivo can be released from damaged bacterial cells facilitated creating controlled environment in AGS cell cultures in vitro. However, this model did not mimic complexity of live bacterial infection. This study prompts further research for deepening the mechanisms of anti-cancer activity and efficacy of the developed PLA-His-NPs.