ABSTRACT
AIM: To study the effect and mechanism of glx351322, an inhibitor of NADPH oxidase (NOX4), on the formation of tumor associated fibroblasts (CAFs). METHODS: NIH3T3 cells were co-cultured with H22 cells. 5 μm (IC50) GLX351322 cells were pretreated with NIH3T3. After PI staining, flow cytometry was used to detect the change of cell cycle, immunofluorescence staining was used to detect the expression of CAFs markers α-SMA and FAP, Western blot was used to detect the expression of CAFs markers α-SMA, Desmin, FAP, TSP-1, FSP, CyclinD, TGF-β1 and Smad1.After H22 was used to construct tumor bearing mice model, GLX351322 was used for treatment,Immunohistochemical staining was used to detect the expression of α-SMA and CAFs in tumor tissue. RESULTS:GLX351322 pretreatment could inhibit the proliferation of NIH3T3, decrease cell viability and change cell cycle. At the same time, it could down-regulate the expression of α-SMA, desmin, FAP, TSP-1, FSP, CyclinD, and TGF-β signal was inhibited. GLX351322 also significantly inhibited the expression of α-SMA and CAFs markers in tumor mice. CONCLUSION: GLX351322, a NOX4 inhibitor, can inhibit the formation of tumor-related fibroblasts, which is related to the inhibition of TGF-β signal.
ABSTRACT
Objective To explore the mechanism and biological significance of differentiation of myeloid-derived suppressor cells (MDSCs) mediated by cancer-associated fibroblasts (CAFs) in the pancreatic ductal adenocarcinoma (PDAC), so as to provide theoretical and experimental basis for revealing the roles of CAFs and MDSCs in promoting the progression of pancreatic cancer by remodeling the pancreatic cancer microenvironment. Methods We isolated and purified primary CAFs from PDAC tumor tissues, and screened the up-regulated cytokines in CAFs by quantitative real-time PCR and enzyme-like immunosorbent assay. The human foreskin fibroblasts (HFFs) were used as controls. Human peripheral blood mononuclear cells (PBMCs) were cultured with supernatant of CAFs and HFFs, respectively. The differentiation of PBMCs was observed and the mechanisms of the above cytokines in regulating the differentiation and recruitment of MDSCs were studied. Results The biomarkers (α-smooth muscle actin [α-SMA] and fibroblast activation protein a [FAPa]) were detected in the isolated primary CAFs, but not found in the HFFs. The expression levels of interleukin 6 (IL-6), stromal cell-derived factor 1 (SDF-1) and monocyte chemotactic protein 1 (MCP-1) in the culture supernatant were significantly gradually increased in the CAFs than those in the HFFs (all P0.01). Compared with culture supernatant of HFFs, the culture supernatant of CAFs promoted more PBMCs to differentiate into CD13-high expression neutrophil-like MDSCs (CD13hi-nMDSCs; P0.01). IL-6 human recombinant protein alone in the co-culture system could induce the differentiation of PBMCs into CD13hi-nMDSCs (P0.01). SDF-1 or MCP-1 human recombinant protein alone could not induce the increase of CD13hi-nMDSCs subpopulation. IL-6 neutralizing antibody or signal transducer and activator of transcription 3 (STAT3) blocker FLLL32 could significantly inhibit the differentiation induced by the culture supernatant of CAFs (P0.05). Conclusion CAFs can promote the differentiation of PBMCs into CD13hi-nMDSCs via the IL-6/STAT3 pathway.
ABSTRACT
Tumor-associated fibroblasts(TAFs),the most important stromal cells of the tumor microenvironment (TME),have been found to support tumorigenesis and tumor metastasis in a variety of ways,including paracrine, direct contact with cells,immune regulation and extracellular matrix remolding.Therefore,TAFs in the TME have been an optimal target for cancer therapy.In this review,the TAFs targeted therapies are summarized to provide the new strategy for tumor treatments based on the analysis of the location and specific biological phenotypes of TAFs in tumors.