Grifolin Inhibits Tumor Invasion And Metastasis Through ERK1/2Pathways

In earlier research, we get grifolin, which is a new small molecular probe possesses anti-tumor activity, from higher fungi fruiting bodies extract. As one of Nikki phenolic compounds, grifolin has broad-spectrum antitumor activity, inducing cell cycle arrest and apoptosis of tumor cells. So this issue focus on grifolin, exploring its effects on tumor cell invasion and metastasis, and its molecular mechanism of signal transduction of biological functions.First, we use highly metastatic tumor cell line, through in vitro cell and animal experiments to determine its biological effects of grifolin on tumor metastasis. By MTS, scratched experiment and pseudopodia labeling experiments, we confirm the inhibition of grifolin on tumor cell proliferation, movement, migration and adhesion. Adhesion and transwell invasion assay verify that grifolin can inhibit the ability of adhesion and invasion of tumor cells. Visual animal models and pathological tool confirm that grifolin can inhibit the metastasis of tumor cells in nude mice.When it is clear that grifolin can inhibit invasion and metastasis of tumor cell, we started exploring its possible mechanism of action. With the help of screening platform used in signal transduction and molecular docking, affinity chromatography and fluorescence quenching experiments, in earlier research,we confirmed grifolin targeting MAPK signal transduction pathway, binding to ERK1/2Kinase protein and inhibit its activity.Transcription factor Elk-1is the substrate of ERK1/2kinase, and westernblot verified grifolin cut Elk-1phosphorylation. Elk-1can binding to Fra-1gene promoter region through serum response element SRE, Co-immunoprecipitation of chromatin, quantitative PCR and westernblot experiment verified grifolin influencing the binding of Elk-1and Fra-1promoter by inhibiting ERK1/2Kinase activity, and reducing the expression of Fra-1.Matrix Metalloproteinase MMPs and Adhesion molecules CD44is linked to tumor invasion and metastasis, and promoter region of MMPs apart from CD44contains AP-1Transcription factor binding sites. Quantitative RCR、Western blot And Immunohistochemistry experiments confirmed grifolin Can significantly reduce MMP-2and CD44mRNA, protein expression levels.Above all, base on the research, we make the conclusion that grifolin can inhibit tumor invasion and metastasis through ERK1/2-Elk-1-Fra-1, and the research provides a new basis for grifolin as an antitumor small molecules probe.