MircoRNA-137 Affects The Epithelial-mesenchymal Transition And Invasion,Migration In Cervical Cancer By Regulating The Expression Of GREM1 Gene

Objective: This academic paper aims to observe how the GREM1 gene affects the epithelial-mesenchymal transition(EMT)in cervical cancer and delineate the functional relevance of micro RNA-137(miR-137)in influencing EMT and biological activities of cervical cancer cells by binding to GREM1.The effect of GREM1 on chemotherapy sensitivity of cervical cancer(CC)cells was preliminarily observed.Methods : With the help of GEO data base,the expression microarray related to cervical cancer could be achieved.Microarray analysis was initially adopted to predict the diferentially expressed genes and the miRNAs related to CC,followed by the measurement of the expression patterns of GREM1,EMT-related factors in the CC tissues and the adjacent tissues.Dual luciferase reporter gene assay was conducted to determine the relationship between miR-137 and GREM1.Expression levels of related factors were tested by q RT-PCR and Western Blot approaches.The regulatory effect of miR-137 on GREM1 was detected by increasing or decreasing the expression of miR-137 and GREM1.A variety of functional tests were used including MTT assay,plate cloning assay,flow cytometry,Transwell assay,scratch test,and nude mouse tumor formation assay,which were used to detect cell proliferation,invasion,migration,apoptosis,as well as tumor formation in vivo.The functional tests described above would validate that miR-137 mediates TGF-?/Smad signal pathway.The effect of GREM1 on chemotherapy sensitivity of Si Ha cells was preliminarily detected by MTT assay.Results: Through the variation test of correspondent expression microarray of cervical cancer,we found that GREM1 gene highly expressed in cervical cancer tissues.The bioinformatics prediction indicated that there was a targeted regulatory relationship between miR-137 and GREM1 gene.The results of Dual luciferase reporter gene assay showed that miR-137 could targetedly inhibit the expression of GREM 1 gene.Comparedto the para-carcinoma tissue,the expression levels of miR-137?Smad4 and E-cadherin in cervical cancer tissues decreased significantly while GREM1?TGF-?1?Smad2?Smad3?N-cadherin and Vimentin increased significantly.Mi RNA expression levels of miR-137 and GREM1 are closely related to FIGO stage,lymphatic metastasis,Vascular invasion,differentiation degree and size of tumor.By increasing the expression of miR-137,the expression levels of GREM1,TGF-?1,Smad2,Smad3,N-cadherin and Vimentin in cervical cancer cells were significantly reduced,and the expression levels of Smad4 and E-cadherin were significantly increased,while the cell proliferation,cloning and formation rate,invasion,migration ability,as well as the S-phase cells significantly reduced,and the apoptosis rate significantly increased.Furthermore,tumor growth in the nude mice slowed down.Low expression of miR-137 can increase proliferation rate as well as accelerate the tumor growth,and enhance the invasion and migration ability,simultaneously,decrease the apoptosis rate of cervical cancer cells.However,Silencing TGF-?1 can reverse all that happened.After cisplatin,paclitaxel and 5-fluorouracil were added into Si Ha cells,with the increase of drug dose,the relative survival rate of cells in each group showed a decreasing trend in MTT.Compared with the control group,the relative survival rate of cancer cells significantly reduced in si RNA GREM1 group,while the result was opposite in GREM1 overexpression group.Conclusions: miR-137 regulates the expression of GREM1 gene.Epithelial mesenchymal transformation(EMT)is activated in cervical cancer tissues,and GREM1 gene promots EMT progression in cervical cancer.By inhibiting the expression of GREM1 gene,miR-137 restrains EMT as well as the proliferation,invasion and migration of cervical cancer cells,inhibits tumor-forming growth in vivo,promotes cell apoptosis too.Down-regulation of TGF-? expression can reverse the fact that cervical cancer cells have increased proliferation,invasion,migration,accelerated cell growth,and decreased cell apoptosis which are caused by low expression of miR-137.By targeting GREM1 gene,miR-137 prevents the abnormal activation of TGF-?/Smad signal pathway,and inhibits the epithelial-mesenchymal transformation of cervical cancer as well as the invasion and metastasis of cervical cancer cells.High expression of GREM1 reduces the chemosensitivity of cervical cancer cells.