miR-497调控PlexinA4对鼻咽鳞状细胞癌侵袭和迁移能力的影响研究

Effects of miR-497 regulating PlexinA4 on the invasion and migration of nasopharyngeal squamous cell carcinoma

目的观察miR-497在鼻咽鳞状细胞癌侵袭和迁移过程中的作用及机制。方法收集2017年1月至2018年12月就诊且经病理学确诊的鼻咽鳞状细胞癌患者60例的癌组织及相应癌旁组织,免疫组织化学检测PlexinA4的表达,qRT-PCR检测miR-497及PlexinA4mRNA的表达,以HEP-2细胞系为研究对象,构建稳定过表达miR-497的细胞,Western blot检测PlexinA4的表达量,划线法检测细胞的迁移能力,Transwell法检验细胞的侵袭能力,荧光素酶试验验证PlexinA4与miR-497的靶向关系。结果免疫组织化学结果显示PlexinA4在鼻咽鳞状细胞癌组织中的阳性表达率为86.67%(52/60),明显高于癌旁组织中的阳性表达率33.33%(20/60),差异有统计学意义(χ2=35.556,P=0.000)。qRT-PCR结果显示鼻咽鳞状细胞癌组织中的PlexinA4 mRNA的表达量显著高于癌旁组织,miR-497的表达量显著低于癌旁组织,差异有统计学意义(P<0.01)。Western blot检测结果显示miR-497过表达组中PlexinA4的表达明显低于空白对照组与阴性对照组(P<0.001);双荧光素酶报告基因检测结果显示miR-497与PlexinA4具有靶向关系;miR-497过表达组HEP-2迁移率明显低于空白对照组和阴性对照组,差异有统计学意义(P<0.01);miR-497过表达组穿透细胞数明显低于空白对照组和阴性对照组,差异有统计学意义(P<0.01)。结论miR-497在鼻咽癌组织中低表达,过表达miR-497可以引起PlexinA4表达量下降,并引起癌细胞侵袭和迁移能力减弱。

Objective To observe the effects and action mechanism of mir-497 in the invasion and migration of nasopharyngeal squamous cell carcinoma.Methods A total of 60 patients with nasopharyngeal squamous cell carcinoma who were admitted and treated in our hospital from January 2017 to December 2018 and corresponding adjacent tissues were enrolled in the study.The expression levels of PlexinA4 were detected by immunohistochemistry,and the expression levels of mir-497 and PlexinA4 mRNA were detected by qRT-PCR.The HEP-2 cell line was used as the research object to construct the cells with stable overexpression of miR-497.Western blot was used to detect the expression of PlexinA4,the migration ability of cells was detected by line method.Moreover the invasion ability of cells was detected by Transwell method,and the targeting relationship between PlexinA4 and mir-497 was identified by luciferase assay.Results The immunohistochemical results showed that the positive expression rate of PlexinA4 in nasopharyngeal squamous cell carcinoma was 86.67%(52/60),which was significantly higher than that[33.33%(20/60)]in adjacent tissues(P<0.01).The qRT-PCR results showed that the expression levels of PlexinA4 mRNA in nasopharyngeal squamous cell carcinoma were significantly higher than those in adjacent tissues,however,the expression levels of miR-497 were significantly lower than those in adjacent tissues(P<0.01).Western blot results showed that the expression levels of PlexinA4 in miR-497 overexpression group were significantly lower than those in blank control group and those in negative control group(P<0.01).The detection results of dual luciferase reporter gene showed that miR-497 had a targeting relationship with PlexinA4.The migration rate of HEP-2 in miR-497 overexpression group was significantly lower than that in blank control group and that in negative control group(P<0.01).The penetration cell numbers in miR-497 overexpression group were significantly lower than those in blank control group and those in negative control group(P<0.01).Conclusion The miR-497 is lowly expressed in nasopharyngeal carcinoma tissues,and overexpression of miR-497 may cause a decrease of PlexinA4 expression,which may result in the decrease of invasion and migration ability of cancer cell.