ABSTRACT
OBJECTIVE: To investigate the inhibitory effects of paeoniflorin on migration- and invasion-promoting capacities of gastric cancer associated fibroblasts (GCAFs) and to explore the molecular mechanism underlying the effects. METHODS: Paired gastric normal fifbroblast (GNF) and GCAF cultures were established from resected tissues. GCAFs were treated with control medium, or 2.5, 5 or 10 µg/mL paeoniflorin. Conditioned media were prepared from GNFs, GCAFs, control-treated GCAFs and paeoniflorin-treated GCAFs, and used to culture AGS human gastric cancer cells. The migration and invasion capacities of AGS cells were determined with wound healing test and transwell invasion assay, respectively. The interleukin 6 (IL-6) mRNA and microRNA-149 expression in GCAFs were detected by reverse transcription-quantitative polymerase chain reaction. The IL-6 protein expression and secretion by GCAFs were measured with Western blot and enzyme-linked immunosorbent assay analysis, respectively. The protein levels of phosphorylated signal transducer and activator of transcription 3 (STAT3), matrix metalloproteinase (MMP) and MMP9 in AGS cells were examined by Western blot. RESULTS: GCAFs displayed enhanced capacities to induce AGS cell migration and invasion as compared with GNFs. Paeoniflorin treatment significantly inhibited the migration- and invasion-promoting capacities of GCAFs (P<0.05). GCAFs produced and secreted more IL-6 into the conditioned medium than GNFs, leading to over-activation of STAT3-MMP signaling in AGS cells. Paeoniflorin suppressed IL-6 production and secretion by up-regulating microRNA149 expression in GCAFs, and subsequently prevented GCAFs from activating IL-6-STAT3-MMP signaling of AGS cells. CONCLUSIONS: Paeoniflorin inhibits the migration- and invasion-promoting capacities of GCAFs by targeting microRNA-149 and IL-6. Paeoniflorin is potentially a novel therapeutic agent against cancer microenvironment.
Subject(s)
Adenocarcinoma/pathology , Cancer-Associated Fibroblasts/drug effects , Cell Movement/drug effects , Glucosides/pharmacology , Monoterpenes/pharmacology , Stomach Neoplasms/pathology , Adenocarcinoma/genetics , Adult , Cancer-Associated Fibroblasts/physiology , Cells, Cultured , Culture Media, Conditioned/pharmacology , Down-Regulation/drug effects , Fibroblasts/drug effects , Fibroblasts/physiology , Gene Expression Regulation, Neoplastic/drug effects , Humans , Interleukin-6/genetics , Interleukin-6/metabolism , Male , Margins of Excision , MicroRNAs/genetics , MicroRNAs/metabolism , Neoplasm Invasiveness/prevention & control , Primary Cell Culture , Stomach Neoplasms/genetics , Tumor Microenvironment/drug effectsABSTRACT
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 microRNAs and the expression and secretion of the oncogenic factor, macrophage colony-stimulating 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 microRNA-214 (P < 0.01) and a higher level of microRNA-301a (P < 0.01). Astragaloside IV treatment significantly up-regulated microRNA-214 expression (P < 0.01) and down-regulated microRNA-301a expression (P < 0.01) in GCAFs. Reestablishing the microRNA 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 microRNA expression, and it is promisingly a potent therapeutic agent regulating tumor microenvironment.
