〔Abstract〕 Objective To study the effect and regulatory mechanism of secreted proteins from PSC on pancreatic ductal adenocarcinoma cells(PANC-1). Methods Conditioned medium(CM) from pancreatic stellate cells(PSC) was collected through an indirect co-culture method, and PANC-1 cells were cultured separately with CM for 0, 2, and 24 h. The proliferation phenotype of PANC-1 cells under different stimulation periods was detected using the CCK-8 assay. Proteomic analysis was performed to analyze the changes in protein levels of PANC-1 cells, and the most significant protein changes were validated using Western blot. Results Compared with the control group, the proliferation rate of PANC-1 cells increased after being stimulated by PSC derived CM; The results of proteomic analysis showed that the protein expression of metabolic pathways in PANC-1 cells increased continuously after being cultured in PSC CM for 0, 2, and 24 h. Western blot analysis confirmed an increasing trend of PIK3C2A in PANC-1 cells, indicating that the CM from PSC might promote the proliferation of PANC-1 cells by upregulating the expression of PIK3C2A. Conclusion The CM of PSC may promote the proliferation of PANC-1 cells by upregulating the expression of PIK3C2A, which improves the understanding of the mechanism of interaction between PSCs and pancreatic cancer cells in the tumor microenvironment.