Abstract:

AIM: To inveatigate the effect of polysaccharides on the transformation of bone marrow mesenchymal stem cells (MSC) into tumor associated fibroblasts induced by conditioned medium of hepatoma cells.  METHODS: The medium of human hepatoma cell HepG2（CM）was isolated, and the bone marrow mesenchymal stem cells were divided into normal group, control group and experimental group. The normal group was treated with conventional DMEM medium +10%FBS, the control group was cultured with CM+10%FBS, and the experimental group was cultured with CM+10%FBS +10 mg/L polysaccharides. The cell viability of MSC was detected by CCK-8 kit, the cell proliferation detected by BrdU labeling and flow cytometry, the apoptosis rate was detected by flow cytometry, and the cell cycle was detected by PI staining. Western blot method was used to detect the expression of α smooth muscle agonist (α-SMA), myocin (Desmin), fibroblast activation protein (FAP), thrombin sensitive protein 1 (Tsp-1), and fibroblast specific protein (FSP). The expression of α-SMA, FAP and FSP were detected by immunofluorescence staining. RESULTS:The cell viability of MSC in the control group was significantly higher than that in the normal group and the experimental group (P<0.05). There was no significant difference of the apoptosis rate among the three groups (P>0.05). In the control group, the proportion of G0/G1 phase decreased, and the proportion of S phase increased in MSC, which was significantly different from that in the normal group and the experimental group (P<0.05). The expression level of α-SMA, Desmin, FAP, Tsp-1, FSP and the expression level of TGF-β1, Smad1 and Smad2 in the control group was significantly higher than those in the normal group and the experimental group (P<0.05). The immunofluorescence results also showed that the level of α-SMA, FAP, FSP and TGF-β1, Smad1 and Smad2 in the control group was significantly higher than those in the normal group and the experimental group (P<0.05). CONCLUSION: Hepatoma cells can promote the transformation of MSC into tumor related fibroblasts, and polysaccharides can inhibit the transformation, which is one of the mechanisms of anti tumor effect of polysaccharides.

Key words: polysaccharides, liver cancer, tumor associated fibroblasts, transformation