miR-200c-3p靶向FOSL1增加乳腺癌细胞化疗敏感性  

miR-200c-3p Enhances Sensitivity of Breast Cancer Cells to 5-Fluorouridine via Targeting FOSL1

作　　者：卢敏莹[1] 贾小婷[1] 罗利云[1] 邱惠思 郑国沛[1] 贺智敏[1] 

机构地区：[1]广州医科大学附属肿瘤医院肿瘤研究所,广州510095

出　　处：《中国生物化学与分子生物学报》2016年第12期1360-1365,共6页Chinese Journal of Biochemistry and Molecular Biology

基　　金：国家自然科学基金(No.81672616;No.81402196);广州市属高校科研项目(No.1201430498)资助~~

摘　　要：化疗耐受是乳腺癌复发转移率居高不下、综合治疗效果难以提高的主要瓶颈。前期研究证实,miR-200c-3p在乳腺癌敏感细胞MCF-7中的表达量显著高于耐药细胞MCF-7/5Fu,提示miR-200c-3p可能参与乳腺癌化疗增敏,但是具体机制不详。生物信息学预测联合双荧光素酶报告基因实验证实,miR-200c-3p靶向调控FOSL1,且在多种肿瘤中miR-200c-3p与FOSL1表达负相关。实时荧光定量PCR技术和Western印迹技术证实,FOSL1在耐药细胞MCF-7/5Fu中的表达量显著高于亲本细胞MCF-7。在MCF-7细胞中,过表达FOSL1能够显著提高该细胞对5-Fu的化疗耐受;在MCF-7/5Fu中,使用siRNA技术沉默FOSL1,将提高该细胞对5-Fu的化疗敏感性。此外,MTT实验还发现,miR-200c-3p抑制剂能够显著上调MCF-7细胞对5-Fu的耐受,但是在此细胞中干扰FOSL1的表达,又可以增加其对5-Fu的化疗敏感性;miR-200c-3p mimics显著增加MCF-7/5Fu细胞的化疗敏感性,上调FOSL1表达后又可逆转miR-200c-3p mimics的化疗增敏作用。总之,miR-200c-3p能够通过靶向FOSL1增加乳腺癌细胞对5-fluorouridine化疗敏感性。Breast cancer has the highest incidence and mortality in female cancers. Chemotherapy can enhance the survival rate of breast cancer patients. However,chemoresistance is the bottle neck of reducing high recurrence rate and improving comprehensive treatment for cancers. Previously, we demonstrated that miR-200c-3p was highly expressed in MCF-7 cells,compared with breast cancer multidrug resistance cells MCF-7/5Fu. This hinted that miR-200c-3p may be conferred to enhance chemosensitivity of breast cancer cells,but the mechanism was still unknown. Here,bioinformatics analysis showed that miR-200c-3p directly targeted FOSL1,and miR-200c-3p were negatively expressed with FOSL1 in several cancers. Similarly,we found that FOSL1 highly expressed in MCF-7/5Fu cells than MCF-7 cells via real-time RT-PCR and Western blot assay. It is showed that FOSL1 and miR-200c-3p was negatively expressed in breast cancer cells. Furthermore,dual-luciferase reporter gene assay demonstrated that miR-200c-3p could reduce luciferase activity of wildtype but not deletion FOSL1 3＇UTR in a dose-dependent manner. MTT assay showed that the chemoresistance of MCF-7 cells with ectopic overexpression FOSL1 to 5-Fu was significantly increased. However,knock-down of FOSL1 remarkablyenhanced the chemosensitivity of MCF-7/5Fu cells to 5-Fu. In addition,it is suggested that miR-200c-3p inhibitor increased the chemoresistance of MCF-7 cells to 5-Fu,but knock-down FOSL1 can reverse this effect. On the contrary,miR-200c-3p mimics increased the chemosensitivity of MCF-7/5Fu cells,but upregulated FOSL1 attenuated the effect of miR-200c-3p mimics on MCF-7/5Fu. In summary,miR-200c-3p directly targeted FOSL1 to enhance the chemosensitivity of breast cancer cells to 5-fluorouridine.

关 键 词：miR-200c-3p FOS样抗原1 化疗敏感性 乳腺癌 

分 类 号：R737.9[医药卫生—肿瘤]