To investigate the sensitizing effect of cyclosporine A (CsA) in combination with radiation therapy on pancreatic cancer cells (BxPC‐3 and MIA PaCa‐2) and explore the underlying mechanisms.

Network pharmacology was used to identify the common targets between CsA, ferroptosis, and radiosensitization for pancreatic cancer, followed by enrichment analysis and molecular docking predictions. In vitro experiments were performed using BxPC‐3 and MIA PaCa‐2 pancreatic cancer cell lines. Cells were divided into five groups: control, CsA alone, irradiation alone, CsA plus irradiation, and CsA plus irradiation plus Ferrostatin‐1 (Fer‐1). The CCK‐8 assay was used to assess the effect of CsA on cell viability and determine the optimal concentration for subsequent experiments. Cell survival and proliferative capacity were evaluated via trypan blue staining and clonogenic assays. Apoptosis was measured by flow cytometry, and lipid peroxidation levels were determined using the BODIPY 581/591 C11 probe. Real‐time quantitative PCR (RT‐qPCR) and Western blotting were used to analyze the expressions of ACSL4, SLC7A11, and GPX4 at both the mRNA and protein levels.

Network pharmacology analysis suggested that CsA might regulate the ferroptosis pathway through the key target SLC7A11. In vitro experiments showed that CsA significantly reduced pancreatic cancer cell viability in a concentration‐dependent manner compared to the control group, with a synergistic effect when combined with irradiation. Compared with the irradiation‐alone group, the combination of CsA and irradiation significantly reduced cell viability, inhibited cell proliferation, decreased colony formation, and promoted apoptosis. These effects were partially reversed by the ferroptosis inhibitor Fer‐1. Mechanistically, the combination of CsA with irradiation significantly induced lipid peroxidation, downregulated the expressions of SLC7A11 and GPX4, and upregulated the expression of ACSL4, all of which were reversed by Fer‐1.

CsA enhances the radiosensitivity of pancreatic cancer cells by modulating the SLC7A11/GPX4/ACSL4 signaling axis to induce ferroptosis. This study provides evidence for clinical applications of CsA as a ferroptosis‐inducing radiosensitizer in pancreatic cancer.

To establish a human intestinal organ-on-a-chip model using a multi-array chip array to simulate the microphysiological structure of the human intestine and to investigate the impact of ionizing radiation on radiation-induced damage to human intestinal cells.

Caco-2 and human umbilical vein endothelial cells (HUVECs) were co-cultured in an organ chip. The cells were subjected to fluid shear stress via a precision shaker. After 7 days of dynamic culture,the morphological structure of intestinal epithelial cells and venous endothelial cells within the intestinal organ chip was examined using phase contrast microscopy,immunofluorescence staining,and confocal microscopy for three-dimensional (3D) imaging. γ-H2AX and TUNEL immunofluorescence staining were employed to assess DNA damage and apoptosis in intestinal epithelial cells two days post-irradiation. Villin immunofluorescence staining was used to evaluate villus height three days post-irradiation. EdU incorporation assay and Ki67 immunofluorescence staining were conducted to observe the effects of ionizing radiation on the proliferation of intestinal epithelial cells.

After 7 days of dynamic culture,phase contrast microscopy and immunofluorescence staining combined with confocal 3D imaging revealed that the upper intestinal epithelial cells in the middle compartment of the chip formed a 3D intestinal villus structure,while the vascular endothelial cells in the lower compartment developed a vascular network structure. The chip was subsequently irradiated by 10 Gy X-ray. Immunofluorescence staining results indicated that the mean fluorescence intensity of γ-H2AX and TUNEL in the irradiated group was significantly higher than in the non-irradiated group 2 days after irradiation (P<0.01),and that the proportion of EDU⁺ and Ki67⁺ cells in the irradiated group was significantly lower than in the non-irradiated group three days after irradiation (P<0.05).

Caco-2 cells and HUVECs co-culture on an organ chip can generate the biomimetic structure of human intestinal villus. Ionizing radiation has been found to shorten intestinal villus,increase DNA damage and apoptosis in intestinal epithelial cells,and inhibit the proliferation of these cells.