679 Novel 4-thiazolidinone derivative Les-4367 synergizes with trastuzumab and pertuzumab to suppress immune evasion markers in HER2-positive gastric cancer
Year: 2026
Type: conference-abstract
Abstract: Background HER2 overexpression drives oncogenic signaling in a subset of gastric cancers, and trastuzumab combined with chemotherapy remains the standard first-line treatment for HER2-positive disease. However, clinical outcomes remain poor, underscoring the need for novel therapeutic strategies. 4-Thiazolidinone-based hybrid molecules represent a promising class of multi-targeting anticancer agents. Here, we investigated the molecular mechanism of action of a novel pyrazoline-thiazolidinone derivative, Les-4367, alone and in combination with anti-HER2 monoclonal antibodies trastuzumab and pertuzumab, with focus on apoptosis, autophagy suppression, and immunomodulatory effects in HER2-positive gastric cancer cells.Methods Human AGS gastric cancer cells (HER2 +) were treated with Les-4367 (1–5 μM) alone or combined with trastuzumab or pertuzumab (10 μg/mL) for 24 h. Cell viability and DNA biosynthesis were assessed by fixable viability staining and [3H]thymidine incorporation assay. Apoptosis was quantified by Annexin V-FITC/propidium iodide flow cytometry. Caspase-8 and caspase-9 activity were measured by FAM-FLICA assay, and autophagy by ICT Autophagy Assay Red. Autophagy markers Beclin-1, LC3A, LC3B, and ATG5 were evaluated by ELISA and Western blot. Concentrations of MMP-2, ICAM-1, IL-6, IL-8, and IL-10 were determined by ELISA.Results Les-4367 displayed potent cytotoxicity in AGS cells (IC 50 1.5 μM). Both antibodies markedly enhanced its efficacy: at 1 μM Les-4367, dead cell fractions reached 67.9% with trastuzumab and 83.0% with pertuzumab, compared with 44.8% for monotherapy. Combination regimens amplified apoptosis (69.8% with pertuzumab vs. 56.2% alone) and activated both extrinsic and intrinsic apoptotic pathways, with caspase-8 activity rising to 83.7–84.6% and caspase-9 to 87.3–87.6% of the cell population. Autophagy was suppressed in all combination groups, confirmed by reduced Beclin-1, LC3A, LC3B, and ATG5 levels. Key immune evasion markers were downregulated: MMP-2 decreased from 700 to 225.6 ng/mL (Les-4367 + pertuzumab) and ICAM-1 from 481 to 358.5 pg/mL (Les-4367 + trastuzumab). Pro-inflammatory cytokines IL-6 (17.99 → 12.2 pg/mL) and IL-8 (246.3 → 193.0 pg/mL) were reduced, while anti-inflammatory IL-10 increased to 49.1 pg/mL with trastuzumab versus 34.0 pg/mL in controls.Conclusions The combination of Les-4367 with trastuzumab or pertuzumab exerts synergistic anticancer activity in HER2-positive gastric cancer through dual apoptotic pathway activation, autophagy suppression, and downregulation of immune evasion markers MMP-2 and ICAM-1, alongside a favourable anti-inflammatory cytokine shift. These findings support Les-4367 as a promising candidate for combination immunotherapy strategies targeting the HER2 pathway in gastric cancer.
Language: English
Topic: HER2/EGFR in Cancer Research
Subfield: Oncology
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $2,490
OpenAlex ID: W7225335218