Objective This study aimed to examine how gambogic acid (GA) modulates pancreatic cancer cell sensitivity to gemcitabine (GEM) chemotherapy, and to elucidate the underlying molecular mechanisms involved. Methods GEM-resistant pancreatic cancer cell lines were established using a concentration-escalation method, and GA suppressive activity against drug-resistant cell proliferation was assessed. The influence of GA on leucine-rich repeat-containing protein 8A (LRRC8A) expression was examined with quantitative reverse transcription PCR(RTqPCR)and Western Blot analyses. A LRRC8A-knockdown patient-derived organoids (PDOs) model was constructed,and the half-maximal inhibitory concentration of GEM post-knockdown was measured using the Cell Titer-Glo luminescence assay to explore the synergistic effect of GA and GEM on cell viability. Potential targets through which GA mitigates chemoresistance were forecasted using network-based pharmacological approaches and molecular docking simulations, with subsequent Western Blot analyses providing experimental verification. Murine xenograft models bearing human pancreatic carcinoma were established to monitor the therapeutic impact of GA on neoplastic growth.Comparative immunohistochemical analysis of LRRC8A expression levels was conducted pre- and post-intervention. Results GA significantly inhibited the growth of GEM-resistant pancreatic cancer cells and patient-derived organoids and effectively enhanced cellular sensitivity to GEM by regulating LRRC8A/ STAT3 signaling. In vivo experiments further confirmed that GA intervention significantly reduced LRRC8A expression and suppressed pancreatic cancer progression. Conclusions GA-mediated downregulation of LRRC8A conferred GEM sensitivity in pancreatic cancer cells.