Anticancer research, cilt.46, sa.3, ss.1461-1474, 2026 (SCI-Expanded, Scopus)
BACKGROUND/AIM: Colon and gastric cancers are among the most prevalent gastrointestinal malignancies, often exhibiting poor prognosis due to resistance and recurrence. Polo-like kinase 1 (PLK1), a key regulator of mitosis, is frequently overexpressed in these cancers. BI-2536, a selective PLK1 inhibitor, has shown promising anticancer activity. β-Glucan, a natural immunomodulator, has also demonstrated anticancer potential. This study aimed to evaluate the antiproliferative, apoptotic, and cell cycle effects of BI-2536 alone and in combination with β-glucan on HT-29 colon and AGS gastric cancer cell lines. MATERIALS AND METHODS: Cell viability was assessed using the XTT assay. Apoptosis and cell cycle profiles were evaluated using flow cytometry. The combination index (CI) was calculated using the Chou-Talalay method via CompuSyn software. RESULTS: BI-2536 significantly inhibited proliferation and induced G2/M arrest and apoptosis in both cell lines. β-Glucan showed moderate cytotoxicity and enhanced BI-2536's effects. Synergistic antiproliferative activity was observed at lower drug concentrations, such as 2-16 nM BI-2536 combined with 31.25-250 μg/ml β-glucan (CI<1). The combination induced greater apoptosis and more pronounced G2/M arrest compared with either agent alone, demonstrating a clear synergistic effect. CONCLUSION: BI-2536 in combination with β-glucan exhibits synergistic anticancer effects in vitro, suggesting a promising strategy for treating colon and gastric cancers.