Polysaccharides have been known to display their anti-cancer activity via immunomodulation. The immunomodulation of RAW 246.7 macrophages by astragalus polysaccharide (APS) is herein studied in human breast cancer cells. Apart from traditional 2D culture, a novel tissue-engineered tumor model is prepared based on decellularized porcine lung scaffold. Decellularized lung scaffolds exhibit preferable biocompatibility that promote the formation and enlargement of tumor spheroids. The conditioned medium (CM, the supernatant liquid of APS-treated RAW264.7 macrophages) shows anti-cancer activity by inhibiting cell proliferation, demonstrated by a 39.25 ± 5.04% decrease in tumoroid size and 20.96 ± 2.43% reduction in cell viability, and promoting cell apoptosis by the nuclear fragmentation and increasing apoptotic-stage proportion. The cytotoxicity of CM is associated with the upregulated production of nitric oxide and tumor necrosis factor-α from RAW 246.7 cells stimulated by APS. Overall, by using this 3D tumor model to study CM, there is convincing evidence that APS can modulate macrophage function to further mediate anti-cancer activity.
Keywords: 3D tumor models; astragalus polysaccharides; decellularized porcine lung scaffolds; immunoregulation; macrophage activation.
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