Aberrant activation of CYR61 enhancers in colorectal cancer development

Journal of Experimental & Clinical Cancer Research

Ting Su¹  Zikai Chen¹  Xiaolan Chang¹  Tian Xu¹  Lingzhu Xie¹  Man Xu¹  Qidong Li¹  Tangfei Guo¹  Xuhong Song¹  Dongyang Huang²  Bin Liang²  Hao Lin³  Long-Kun Wang⁴ 

[1] 0000 0004 0605 3373, grid.411679.c, Department of Cell Biology and Genetics, Key Laboratory of Molecular Biology in High Cancer Incidence Coastal Chaoshan Area of Guangdong Higher Education Institutes, Shantou University Medical College, 515041, Shantou, China;0000 0004 0605 3373, grid.411679.c, Department of Cell Biology and Genetics, Key Laboratory of Molecular Biology in High Cancer Incidence Coastal Chaoshan Area of Guangdong Higher Education Institutes, Shantou University Medical College, 515041, Shantou, China;0000 0004 0605 3373, grid.411679.c, Department of Cell Biology and Genetics, Shantou University Medical College, Complex Building, Room 602, No. 22 Xinling Road, Shantou, Guangdong, China;grid.452734.3, Department of Gastroenterology, Shantou Central Hospital, 515041, Shantou, China;grid.460061.5, Department of Clinical Laboratory, Jiujiang First People’s Hospital, 332000, Jiujiang, China;

关键词: CYR61;    Enhancer;    FOXA1;    CBP;    H3K27ac;    Colorectal cancer;   

DOI  :  10.1186/s13046-019-1217-9

来源: publisher

【 摘 要 】

BackgroundHigh expression of secreted matricellular protein cysteine-rich 61 (CYR61) correlates with poor prognosis in colorectal cancer (CRC). Aberrant enhancer activation has been shown to correlate with expression of key genes involved in cancer progression. However, such mechanisms in CYR61 transcription regulation remain unexplored.MethodsExpression of CYR61 was determined by immunohistochemistry (IHC), quantitative real-time PCR (qRT-PCR) and western blotting (WB) in CRC patients paraffin specimens and colon cell lines. ChIP-seq data of enhancer-characteristic histone modifications, in CRC tissues from the Gene Expression Omnibus (GEO) database, were reanalyzed to search for putative enhancers of CYR61. Dual-luciferase reporter assay was used to detected enhancer activity. Physical interactions between putative enhancers and CYR61 promoter were detected by chromosome conformation capture (3C) assay. Histone modification and transcription factors (TFs) enrichment were detected by ChIP-qPCR. Additionally, biological function of enhancers was investigated by transwell migration assays.ResultsCRC tissues and cell lines expressed higher level of CYR61 than normal colon mucosa. Three putative enhancers located downstream of CYR61 were found in CRC tissues by ChIP-seq data reanalysis. Consistent with the ChIP-seq analysis results in the GEO database, the normal colon mucosal epithelial cell line NCM460 possessed no active CYR61 enhancers, whereas colon cancer cells exhibited different patterns of active CYR61 enhancers. HCT116 cells had an active Enhancer3, whereas RKO cells had both Enhancer1 and Enhancer3 active. Pioneer factor FOXA1 promoted CYR61 expression by recruiting CBP histone acetyltransferase binding and increasing promoter-enhancer looping frequencies and enhancer activity. CBP knockdown attenuated H3K27ac enrichment, promoter-enhancer looping frequencies, and enhancer activity. Small molecule compound 12-O-tetradecanoyl phorbol-13-acetate (TPA) treatment, which stimulated CYR61 expression, and verteporfin (VP) treatment, which inhibited CYR61 expression, confirmed that the enhancers regulated CYR61 expression. Knockdown and ectopic expression of CYR61 rescued cell migration changes induced by over-expressing and knockdown of FOXA1, respectively.ConclusionsCYR61 enhancer activation, mediated by FOXA1 and CBP, occurs during CRC progression to up-regulate CYR61 expression and promote cell migration in CRC, suggesting inhibition of recruitment of FOXA1 and/or CBP to CYR61 enhancers may have therapeutic implications.

【 授权许可】

CC BY