Effects Of Knock-down Sp1 On Expression Of STGC3 And The Malignant Phenotype Of CNE2 Cells

objective: To explore the regulatory function of Sp1 to STGC3 gene and the effects of knock-down Sp1 on growth, proliferation,invasion and migration of nasopharygeal carcinoma CNE2 cells.Method: 1 siRNA targeting Sp1 was built in GTP-HIS lentiviral vector and transfected into nasopharyngeal carcinoma CNE2 cell line. In order to make sure that the GTP-HIS-Sp1-CNE2 was constructed successfully.We detected the expression level of Sp1 by Quantitative Real-time RT-PCR(qRT-PCR) and Western Blotting.2The experiment was divided into three groups,GTP-HIS-Sp1-CNE2,GTP-HIS-CNE2 and CNE2. The effects of knock-down Sp1 on expression of STGC3 gene in CNE2 cells were detected by Quantitative Real-time RT-PCR(qRT-PCR) and Western Blotting after silencing Sp1.The effects of Sp1 knock-down on cell growth,proliferation,invasion and metastasis of CNE2 cells were evaluated by MTS, Transwell, flow cytometry and cell colone formation experiment, respectively.Result:1.The lentiviral vector targeting Sp1 gene was successfully constructed and efficiently infected into CNE2 cells.The results of qRT-PCR and Western Blotting revealed that siRNA against Sp1 significantly decreased the mRNA and protein expressions of Sp1.The CNE2 cell line of knock-down Sp1 was successfully established.The results of qRT-PCR and Western Blotting showed that inhibition of Sp1 expression by distinct siRNA against Sp1 could increase the expression of STGC3 gene in CNE2 cells. Knock-down Sp1 can promote the expression of STGC3 and transcription factor Sp1 negatively regulates STGC3 gene expression in nasopharyngeal carcinoma CNE2 cells.The results of MTS and the colony-forming assay and Transwell indicated that Sp1 silencing may suppress cell growth, proliferation,invasion and metastasis capability. Flow cytometry experiment showed that cell proportion of G1 phase were 78.31 % in experimental group,which was much higher than that in the bland load transfection group and control group(68.26%and 67.33%),The apoptosis rates of CNE2 cells in experimental group was 14.56%, while that in the bland load transfection group and control group was only 9.9% and 10.42%,this result indicated that reducing expression of Sp1 inhibits CNE2 cell cycle arrested in G1 phase.Conclusion:1.Knock-down Sp1 can promote the expression of STGC3 and transcription factor Sp1 negatively regulates STGC3 gene expression in nasopharyngeal carcinoma CNE2 cells.2. Knock-down Sp1 can reverse some malignant phenotypes of CNE2.