Astragaloside Ⅳ inhibits pathological functions of gastric cancer-associated fibroblasts

AIM To investigate the inhibitory effect of astragaloside IV on the pathological functions of cancer-associated fibroblasts,and to explore the underlying mechanism.METHODS Paired gastric normal fibroblast(GNF) and gastric cancer-associated fibroblast(GCAF) cultures were established from resected tissues. GCAFs were treated with vehicle control or different concentrations of astragaloside Ⅳ. Conditioned media were prepared from GNFs,GCAFs,control-treated GCAFs,and astragaloside Ⅳ-treated GCAFs,and used to culture BGC-823 human gastric cancer cells. Proliferation,migration and invasion capacities of BGC-823 cells were determined by MTT,wound healing,and Transwell invasion assays,respectively. The action mechanism of astragaloside Ⅳ was investigated by detecting the expression of micro RNAs and the expression and secretion of the oncogenic factor,macrophage colonystimulating factor(M-CSF),and the tumor suppressive factor,tissue inhibitor of metalloproteinase 2(TIMP2),in different groups of GCAFs. The expression of the oncogenic pluripotency factors SOX2 and NANOG in BGC-823 cells cultured with different conditioned media was also examined.RESULTS GCAFs displayed higher capacities to induce BGC-823 cell proliferation,migration,and invasion than GNFs(P < 0.01). Astragaloside Ⅳ treatment strongly inhibited the proliferation-,migration-and invasion-promoting capacities of GCAFs(P < 0.05 for 10 μmol/L,P < 0.01 for 20 μmol/L and 40 μmol/L). Compared with GNFs,GCAFs expressed a lower level of micro RNA-214(P < 0.01) and a higher level of micro RNA-301 a(P < 0.01). Astragaloside Ⅳ treatment significantly upregulated micro RNA-214 expression(P < 0.01) and down-regulated micro RNA-301 a expression(P < 0.01) in GCAFs. Reestablishing the micro RNA expression balance subsequently suppressed M-CSF production(P < 0.01) and secretion(P < 0.05),and elevated TIMP2 production(P < 0.01) and secretion(P < 0.05). Consequently,the ability of GCAFs to increase SOX2 and NANOG expression in BGC-823 cells was abolished by astragaloside Ⅳ.CONCLUSION Astragaloside Ⅳ can inhibit the pathological functions of GCAFs by correcting their dysregulation of micro RNA expression,and it is promisingly a potent therapeutic agent regulating tumor microenvironment.