Fabrication and Characterization of a Three-Dimensional Fibrin Gel Model to Evaluate Anti-Proliferative Effects of Astragalus hamosus Plant Extract on Breast Cancer Cells

BACKGROUND: Breast Cancer (BC) is a malignancy with high mortality among women. Recently, scaffold-based three-dimensional (3D) models have been developed for anti-cancer drug research. The present study aimed to investigate the anti-proliferative effects of Astragalus hamosus (A. hamosus) in 3D fibrin gel against MCF-7 cell line. We have also evaluated anti-proliferative effect of A. hamosus differences between 3D and 2D cultures. METHODS: The fibrin gel formulation was first optimized by testing the structural and mechanical properties. Then the cytotoxic effect of A. hamosus extract was assessed on MCF-7 cells by MTT assay. Cell apoptosis was evaluated using TUNEL method and flow cytometry. Cell cycle and proliferation were analyzed by flow cytometry. Apoptosis-related gene expression such as Bcl-2, caspase-3, -8 and -9 were quantified by real time-PCR. RESULTS: TUNEL staining showed a significant damage accompanied with cell apoptosis. Flow cytometry analysis revealed that apoptosis increased after treatment with A. hamosus extract in 3D culture model compared to 2D culture. The A. hamosus extract arrested cell cycle in the S and G2/M phases in 3D model while in the 2D culture G0/G1 phase was affected. Treatment with A. hamosus extract led to upregulation of the caspase-3, -8 and -9 genes and downregulation of the Ki-67 in the 3D-culture compared with the 2D culture. CONCLUSION: These results indicated that A. hamosus extract could be used as a therapeutic candidate for BC due to its anti-proliferative effects. Furthermore, 3D fibrin gel could be better than 2D-cultured cells in simulating important tumor characteristics in vivo, namely, anti-proliferative and anti-apoptotic features.