CALML3-AS1通过靶向let-7i-5p抑制鼻咽癌细胞的增殖和侵袭OA

Objective:To investigate the effect of long noncoding RNA(lncRNA)CALML3-AS1 on the proliferation and invasion of nasopharyngeal carcinoma cells and its underlying molecular mechanism.Methods:The lnCAR database was used to analyze the expression level of CALML3-AS1 in nasopharyngeal carcinoma tissues and its correlation with the clinical stage of nasopharyngeal carcinoma patients.The expression level of CALML3-AS1 in nasopharyngeal carcinoma cell lines(5-8F,C666-1,SUNE-1,CNE-2Z,and 6-10B)was detected by RT-q PCR.CALML3-AS1 overexpression plasmid or corresponding control plasmid was transfected into C666-1 cells through liposome transfection technology and designated as the CALML3-AS1 group and NC group,respectively.Cell proliferation and invasion of C666-1 cells were detected by CCK-8 assay and Transwell assay.The targeting relationship between CALML3-AS1 and let-7i-5p was verified by dual-luciferase reporter gene experiment.The correlation between CALML3-AS1 and let-7i-5p expression in nasopharyngeal carcinoma tissues was analyzed by lnCAR database.RT-qPCR was used to detect the effect of CALML3-AS1 on the expression of let-7i-5p in C666-1 cells.Western blotting was adopted to detect the effect of CALML3-AS1 on the expression of proliferation and invasion-related proteins in C666-1 cells.Results:The expression of CALML3-AS1 was significantly lower in nasopharyngeal carcinoma tissues than that in adjacent tissues.The expression level of CALML3-AS1 was negatively correlated with the clinical stage of nasopharyngeal carcinoma patients.Compared with immortalized nasopharyngeal carcinoma NP69 cells,CALML3-AS1 was expressed at low levels in various nasopharyngeal carcinoma cells.Compared with the NC group,overexpression of CALML3-AS1 could inhibit the proliferation of C666-1 cells.The number of invading cells was(141.00±7.26)in the NC group and(25.30±6.07)in the CALML3-AS1 group,indicating that overexpression of CALML3-AS1 could significantly inhibit the invasion of C666-1 cells.CALML3-AS1 could directly target and bind to let-7i-5p.The expression of CALML3-AS1 was negatively correlated with let-7i-5p in nasopharyngeal carcinoma tissues.Overexpression of CALML3-AS1 could downregulate the expression of let-7i-5p.Compared with the NC group,the expression of proliferation-related proteins(cyclin E and cyclin-dependent kinase 2)in C666-1 cells in the CALML3-AS1 group and invasion-related proteins(transforming growth factor-β and fibronectin)decreased.Conclusion:Overexpression of CALML3-AS1 can inhibit the proliferation and invasion of nasopharyngeal carcinoma C666-1 cells,and its mechanism may be related to the targeted downregulation of let-7i-5p expression.