The Regulational Mechanisms Of Biomechanical Property Of Human Melanoma Cancer Cells During Epithelial-Mesenchymal Transition

Tumor metastasis is a process in which malignant tumor cells continue to grow from the primary site through lymphatic,vascular or body cavity pathways to other sites.Tumor metastasis is the main reason for the failure of cancer treatment.In the process of tumor metastasis,tumor cells will undergo metastasis,invasion,adhesion and other processes,which are based on the movement and deformation of tumor cells.The ability of movement and deformation of cancer cells is related to the mechanical properties of cancer cells.The mechanical properties of cancer cells mainly include the stiffness and stickiness of cancer cells.Studies have shown that EMT(Epithelial-Mesenchymal Transition)is closely related to tumor metastasis.After EMT,the ability of tumor cells to migrate,invade and form metastases has been greatly enhanced.This paper mainly explores the changes of mechanical properties of tumor cells in the process of EMT.This study is expected to provide new ideas for cancer treatment.In this study,tumor cells were treated with 10 ng/ml of TGF-?1 for 48 hours,which was induced by simulating the process of EMT.Based on this,we explored the changes of the mechanical properties of cancer cells and their regulatory mechanisms in the process of EMT.In the experiment,tumor cells were treated with 10 ng/ml TGF-?1.The changes of cell morphology,EMT marker protein,migration and invasive ability of tumor cells were investigated after different time(0 h,12 h,24 h,48 h)of drug treatment.Firstly,by inverted microscope observation,it was found that the morphology of tumor cells gradually became longer and longer during 48 h of drug treatment.The results of EF(Elliptical Factor)also showed that the tumor cells became longer and longer during 48 h of drug treatment.By confocal microscopy,Western Blot explored the changes of EMT marker proteins after drug treatment of cancer cells.It was found that Vimentin increased gradually and E-cadherin decreased gradually during drug induction.Then the ability of migration and invasion of cancer cells was explored by scratch test and Transwell chamber test respectively.It was found that the ability of migration and invasion of cancer cells increased significantly.Next,the stiffness changes of tumor cells during EMT induction were investigated by atomic force microscopy.The results showed that the stiffness of tumor cells decreased significantly during EMT induction.The stiffness of tumor cells is mainly determined by actin skeleton.Therefore,the changes of actin skeleton in tumor cells during EMT induction are worth further exploring.The decrease of F/G-actin and the depolymerization of actin filaments in tumor cells were found with the help of confocal microscopy and flow cytometry.In view of this situation,this study explores the molecular mechanism of stiffness reduction of cancer cells in the process of EMT induction.A large number of clinical data show that the survival rate of melanoma patients with high expression of YAP and Arhgap28 is very low.The results of qPCR showed that YAP and Arhgap28 increased significantly in the process of EMT induction,and RhoA-Limk-Cofilin signaling pathway was also significantly affected.When YAP was silenced by sh-RNA,the stiffness and F/G-actin of tumor cells were significantly increased.RhoA activation and cofilin phosphorylation were also promoted.This suggests that YAP can regulate the cytoskeleton of cancer cells through RhoA-Limk-Cofilin signaling pathway and then affect the stiffness of cancer cells.When Arhgap28 was silenced by sh-RNA,F/G-actin increased significantly,RhoA activation and cofilin phosphorylation were also promoted.This suggests that Arhgap28 can regulate the cytoskeleton of cancer cells through the RhoA-Limk-Cofilin signaling pathway,thereby affecting the stiffness of cancer cells.When YAP was silenced,Arhgap28 was found to be significantly lower in the level of RNA and protein by qPCR and Western Blot.However,when Arhgap28 was silenced,the expression of YAP did not change significantly.These results suggest that YAP can affect RhoA-Limk-Cofilin signaling pathway by regulating Arhgap28 to reduce the stiffness of cancer cells in the process of EMT induction.The conclusion of this study is that YAP can promote the expression of Arhgap28 in EMT,and then regulate the stiffness of cancer cells through RhoA-Limk-Cofilin signaling pathway.