AGS cells were pretreated with boldine for one hour and then exposed to temperatures ranging from 37 to 43 degrees Celsius for 30 minutes. Neither intervention alone was dramatic. Hyperthermia by itself pushed the apoptotic fraction to only 3.55 percent, below the 8.08 percent seen in untreated controls, while boldine alone raised it to 28.79 percent.

Combined, the treatments drove apoptosis to 46.33 percent of the cell population. The cotreatment also outperformed either single treatment in reducing cell viability, wound closure in scratch assays, and colony formation, the standard measures of proliferative survival in this system. Behind those numbers, the researchers mapped a coherent set of cellular changes.

The combined treatment shifted the cell-cycle distribution of the population, altering the fractions of cells in S phase and G2/M, and increased accumulation of reactive oxygen species. It also enhanced phosphorylation of MAPK signaling proteins. When the team pretreated cells with N-acetylcysteine, an antioxidant that reduces ROS, both the ROS levels and the apoptotic cell fraction fell, and HSP27 expression was partially restored.

That rescue experiment links the cytotoxic effect to oxidative stress and places HSP27, the heat-shock protein most strongly suppressed by boldine, at the center of the interaction. The stress-response attenuation is the study's key technical claim. Under hyperthermia, boldine suppressed heat shock protein expression, most notably HSP27, and reduced phosphorylation of heat shock factor 1, the transcription factor that normally switches on HSP genes when cells heat up.

By dampening this pathway, boldine appears to strip gastric cancer cells of a defense against heat, allowing a temperature shift that cells would otherwise tolerate to become lethal. In NCI-N87 cells, a second gastric cancer line used for confirmation, cotreatment again produced higher apoptosis, although in that line hyperthermia alone did not further reduce viability or alter HSP levels, indicating that the observed responses may vary between cell contexts. The authors conclude that boldine enhances hyperthermia-induced apoptosis in AGS cells in association with attenuation of the HSF1–HSP stress response and ROS accumulation, supporting boldine as a potential thermosensitizing adjunct in gastric cancer therapy.

The evidence, however, is confined to two cell lines in culture. The findings are associations measured in vitro, not demonstrations that boldine sensitizes tumors in patients, and the doses, timing, and temperature range used in dishes may not translate directly to clinical hyperthermia.

Subject of Research: Boldine as a thermosensitizing adjunct that attenuates the HSF1–HSP stress response in gastric cancer cells

Article Title: Boldine enhances hyperthermia-induced apoptosis in AGS gastric cancer cells in association with attenuation of the HSF1–HSP stress response

Article References: Ahn, C. R., & Baek, S. H. (2026). Boldine enhances hyperthermia-induced apoptosis in AGS gastric cancer cells in association with attenuation of the HSF1–HSP stress response. Molecular Biology Reports, 53(1), Article 1799. https://doi.org/10.1007/s11033-026-12971-9

Image Credits: AI Generated

DOI: 10.1007/s11033-026-12971-9

Keywords: boldine, gastric cancer, hyperthermia, apoptosis, HSF1, heat shock proteins, ROS, MAPK, N-acetylcysteine, AGS cells, NCI-N87, thermosensitizer