Disruption of the c-Myc/miR-200b-3p/PRDX2 regulatory loop enhances tumor metastasis and chemotherapeutic resistance in colorectal cancer

Journal of Translational Medicine

Research

Wenxian You¹  Hua Yang²  Jingkun Shang³  Yongfu Xiong³  Jinlai Wei³  Rong Wang³  Zhongxue Fu³  Zhenbing Lv⁴  Xuanhua Yang⁵ 

[1] Department of Gastroenterology, The First Affiliated Hospital, Chongqing Medical University, 400016, Chongqing, China;Department of Gastrointestinal Surgery, Nanchong Central Hospital, 637000, Nanchong, Sichuan, China;Department of Gastrointestinal Surgery, The First Affiliated Hospital, Chongqing Medical University, 400016, Chongqing, China;Department of Gastrointestinal Surgery, The First Affiliated Hospital, Chongqing Medical University, 400016, Chongqing, China;Department of Gastrointestinal Surgery, Nanchong Central Hospital, 637000, Nanchong, Sichuan, China;The Second Clinical School of North Sichuan Medical College, 637000, Nanchong, Sichuan, China;The Second Clinical School of North Sichuan Medical College, 637000, Nanchong, Sichuan, China;

关键词: Colorectal cancer;    c-Myc;    miR-200b-3p;    PRDX2;    Chemotherapeutic resistance;    Metastasis;   

DOI  :  10.1186/s12967-017-1357-7

 received in 2017-08-23, accepted in 2017-12-04,  发布年份 2017

来源: Springer

【 摘 要 】

BackgroundMetastasis is a major threat to colorectal cancer (CRC) patients. We have reported that peroxiredoxin-2 (PRDX2) is associated with CRC invasion and metastasis. However, the mechanisms regulating PRDX2 expression remain unclear. We investigate whether microRNAs (miRNAs) regulate PRDX2 expression in CRC progression.MethodsQuantitative real-time polymerase chain reaction (qPCR) was used to measure microRNA-200b-3p (miR-200b-3p) expression. Immunohistochemistry (IHC) was performed to detect c-Myc and PRDX2 protein levels in CRC tissue samples (n = 97). Western blot was used to quantify PRDX2, c-Myc, AKT2/GSK3β pathway-associated proteins and epithelial-mesenchymal transition (EMT)-related proteins in CRC cells. Luciferase reporter assays were used to analyze the interaction between miR-200b-3p and 3′untranslated region (3′UTR) of PRDX2 mRNA and AKT2 mRNA as well as c-Myc and the miR-200b-3p promoter. Chromatin immunoprecipitation (ChIP) assay was used to evaluate binding of c-Myc to the miR-200b-3p promoter. Invasive assay and metastatic model were used to assess invasive and metastatic capacities of CRC cells in vitro and in vivo. Moreover, drug-induced apoptosis was measured by flow cytometry.ResultsWe found that miR-200b-3p was significantly downregulated, whereas c-Myc and PRDX2 were upregulated in metastatic CRC cells and CRC tissues compared to their counterparts. An inverse correlation existed between c-Myc and miR-200b-3p, and between miR-200b-3p and PRDX2. We also found that PRDX2 was a target of miR-200b-3p. Importantly, overexpression of nontargetable PRDX2 eliminated the suppressive effects of miR-200b-3p on proliferation, invasion, EMT, chemotherapeutic resistance and metastasis of CRC cells. Moreover, c-Myc bound to the promoter of miR-200b-3p and repressed its transcription. In turn, miR-200b-3p disrupted the stability of c-Myc protein by inducing c-Myc protein threonine 58 (T58) phosphorylation and serine 62 (S62) dephosphorylation via AKT2/GSK3β pathway.ConclusionsOur findings reveal that the c-Myc/miR-200b/PRDX2 loop regulates CRC progression and its disruption enhances tumor metastasis and chemotherapeutic resistance in CRC.

【 授权许可】

CC BY   
© The Author(s) 2017