Mechanism Of Lsm12 In Adhesion And Migration Of Oral Squamous Cell Carcinoma Cells

Oral cancer refers to the cancer occurs in oral and maxillofacial region,and oral squamous cell carcinoma(OSCC)is the most common pathological type,accounting for more than 90%,with the characteristics of early metastasis tendency.It’s preliminarily estimated that more than 30% of oral cancer patients have cervical lymph node metastasis and 15%-21% of patients have occult cervical lymphatic metastasis,which is great challenges in the clinical diagnosis and treatment of oral cancer.Metastasis has always been an urgent problem in tumor so that scholars have deeply researched on the cell migration,cell adhesion,EMT,extracellular matrix remodeling and other related processes.Studies have shown that cell adhesion is an essential basic process in the migration of most tumor cells,by which can affect the ability of tumor cells to migration and invasion.And a variety of drugs targeting cell adhesion molecules have been developed.However,few drugs have ideal therapeutic effect in the clinical treatment of tumor.Therefore,the mechanism of cell adhesion and the research and development of blocking drugs have been the research focus at home and abroad.Like-Smith(LSM)family is one of the RNA binding proteins by identifying specific sequences or secondary structures to form ribonucleoprotein complexes to regulate the processing of RNA,including splicing,modification and maturation.A large number of studies have shown that alternative splicing of RNA plays an important role in the occurrence and development of tumors.However,the role of Lsm12 in the adhesion and migration of tumor cells is unclear.The aim of this study is to explore the mechanism of Lsm12 involved in regulating the migration of OSCC cells through investigating the effect of Lsm12 on the cell adhesion,and to provide new clues for finding an ideal therapeutic target for therapy.Objective: To investigate the effect of over-expression and knock-down of Lsm12 on the cell adhesion,migration and invasion in OSCC,reveal its mechanism of promoting cell migration,so as to provide theoretical guidance for finding effective therapeutic targets for OSCC.Methods: OSCC cells(SCC25)were infected with lentivirus to establish a cell line with stably high and low expression of Lsm12,and then screened by puromycin.Then,scratch assay was applied to investigate the effect of overexpression and knockdown of Lsm12 on cell migration.Transwell assay was performed to further investigate the migration and invasion of cell lines.The effect of knocking down Lsm12 on regulating the ability of cell adhesion to extracellular matrix proteins was detected by the adhesion assay.Finally,the mRNA and protein levels of adhesion protein,Kindlin2,in cells overexpressing and knocking down Lsm12 were respectively detected by qPCR and Western Blot.Results: The results of qPCR and Western Blot showed that the mRNA and protein levels of Lsm12 were both increased in overexpression cells,and decreased in the knockdown cells significantly,suggesting the successful establishment of the cell lines with stably high and low expression of Lsm12 in SCC25.The scratch assay showed that the relative migration distance of Lsm12 overexpression cells was remarkedly longer than that of control cells(p < 0.0001),while shorter in Lsm12 knockdown cells than that of control cells(p < 0.0001).Transwell assay also showed the number of migrated cells of overexpressing Lsm12 was significantly more than that of control cells(p < 0.05).However,less migrated cells of Lsm12 knockdown cells were observed(p < 0.05),as compared to the control cells.The result of adhesion assay showed the downregulation of Lsm12 displayed a decreased ability of adhesion to fibronectin,collagen Ⅰ,collagen Ⅳ,laminin Ⅰ and fibrinogen(p < 0.05,p < 0.01,p < 0.05,p < 0.001)when compared to the control cells.The results of qPCR and Western Blot turned out that the mRNA and protein levels of Kindlin2 in Lsm12 overexpression cells were both increased remarkably,but decreased remarkably in Lsm12 knockdown cells.Conclusion: Lsm12 regulates the expression of adhesion protein Kindlin2,enhances the adhesion of OSCC cells to the extracellular matrix proteins,and significantly promotes the ability of migration and invasion of OSCC cells.Therefore,Lsm12 plays an important role in the occurrence and progression of OSCC and is expected to become an efficient therapeutic target.