Dexamethasone Inhibits TGF-ß1-Induced Cell Migration by Regulating the ERK and AKT Pathways in Human Colon Cancer Cells Via CYR61.

PURPOSE: One of the features in cancer development is the migration of cancer cells to form metastatic lesions. CYR61 protein promotes migration and the epithelial-mesenchymal transition in several cancer cell types. Evidence suggests that CYR61 and dexamethasone are relevant to colorectal cancer. However, relationships between them and colorectal cancer are still unclear. Understanding the molecular mechanism of colorectal cancer progression related with CYR61 and dexamethasone, which is widely used for combination chemotherapy, is necessary for improved therapy. MATERIALS AND METHODS: We used colorectal cancer cells, HCT116, co-treated with transforming growth factor ß1 (TGF-ß1) and dexamethasone to examine the inhibitory migration effect of dexamethasone by migratory assay. Alternatively, both migratory pathways, expression of AKT and ERK, and the target factor CYR61 was also tested by co-treatment with TGF-ß1 and dexamethasone. RESULTS: We report that dexamethasone significantly inhibited TGF-ß1-induced cell migration, without affecting cell proliferation. Importantly, we observed that TGF-ß1 promoted the epithelial-mesenchymal transition process and that dexamethasone co-treatment abolished this effect. ERK and AKT signaling pathways were found to mediate TGF-ß1-induced migration, which was inhibited by dexamethasone. In addition, TGF-ß1 treatment induced CYR61 expression whereas dexamethasone reduced it. These observations were compatible with the modulation of migration observed following treatment of HCT116 cells with human recombinant CYR61 and anti-CYR61 antibody. Our results also indicated that TGF-ß1 enhanced collagen I and reduced matrix metalloproteinase 1 expression, which was reversed by dexamethasone treatment. CONCLUSION: These findings suggested that dexamethasone inhibits AKT and ERK phosphorylation, leading to decreased CYR61 expression, which in turn blocks TGF-ß1-induced migration.

Novel naphthochalcone derivative accelerate dermal wound healing through induction of epithelial-mesenchymal transition of keratinocyte.

BACKGROUND: Wound healing is an intricate process whereby the skin repairs itself after injury. The epithelial-mesenchymal transition (EMT) is associated with wound healing and tissue regeneration. Naphthochalcone derivatives have various pharmaceutical properties. We investigated the effect of a novel naphthochalcone derivative, 2-(5-(2,4,6-trimethoxyphenyl)-4,5-dihydro-1H-pyrazol-3-yl)naphthalen-1-ol (TDPN), on dermal wound healing in vivo and the migration of keratinocytes in vitro. RESULT: We investigated the effect of TDPN on signaling pathway and epithelial-mesenchymal transition through protein and transcriptional expression. The TDPN treatment accelerated dermal closure about 3 days and remodeling of dermis. We found that treatment with TDPN induced the migration of keratinocytes but not cytotoxicity. TDPN induced the phosphorylation of ERK and AKT. TDPN-treated cells showed loss of adherence protein and showed induction of the transcriptional factor Slug, mesenchymal marker, and fibronectin. Moreover, TDPN treatment induced the expression of matrix metalloproteinase-1 (MMP-1), which degrades specific components of the extracellular matrix, thereby providing new substrates that facilitate migration and invasion. MMP expression is considered to be one of the major attributes acquired by cells after EMT. CONCLUSION: We propose that a novel naphthochalcone derivative TDPN is capable of promoting keratinocyte migration via the induction of EMT resulting acceleration of wound closure and matrix remodeling.

Flavonoids promoting HaCaT migration: II. Molecular mechanism of 4',6,7-trimethoxyisoflavone via NOX2 activation.

Flavonoids are major active ingredients in plants and are considered components of food that provide medical or health benefits. They have diversified structures and have effects on human health, including wound healing induction. More than a hundred flavonoids were screened for HaCaT keratinocytes cellular migration measurements and the relationships between their structural properties and the effects promoting cellular migration were examined. Here, among flavonoids used in the previous structure-activity relationship calculations, 4',6,7-trimethoxyisoflavone (TMF) was one of the compounds showing the best activity, so that its molecular mechanism of the wound healing effect on HaCaT keratinocytes was investigated in more detail. Our data revealed that TMF increased the wound healing rate, but not the proliferation rate, in a dose-dependent manner. Treatment of keratinocytes with TMF influenced signaling pathways, affecting the phosphorylation of AKT and ERK in a time-dependent manner. TMF also induced the cell-cell adhesion protein E-cadherin, which is essential for promoting collective cell migration. Furthermore, the TMF treatment group also showed higher ROS and NOX2 transcriptional and protein levels. Correlating with matrix metalloproteinase induction by TMF, levels of extracellular matrix proteins such as collagens I and III were significantly lower in the treatment group. To confirm that the effects of TMF occur through the NOX2 pathway, we co-treated cells with TMF plus an NADPH inhibitor (DPI) or a ROS scavenger (NAC). Western blotting revealed that DPI and NAC attenuated the effect of TMF, suggesting that TMF induces ROS through the NOX2 pathway and regulates keratinocyte migration. In summary, TMF promotes wound healing through NOX2 induction, which leads to collective migration and MMP activation.