title: BRD7 suppresses the growth of Nasopharyngeal Carcinoma cells (HNE1) through negatively regulating beta-catenin and ERK pathways.
abstract: BRD7 is a novel gene which involved NPC in our lab. Our previous studies showed that BRD7 was expressed at high level in normal nasopharyngeal epithelial tissues, but at low level in nasopharyngeal carcinoma biopsies and cell lines. In these papers, we found that ectopic expression of BRD7 can decrease cell proliferation and capability to form colonies in soft agar. FCM (Flow cytometry) assay indicated that the cell cycle progression from G1 to S phase was inhibited and the expression of cyclinD1 was significantly decreased after being transfected with BRD7 in HNE1 cells (NPC cells). To further investigate the molecular mechanism of BRD7 suppression of NPC cells growth, the cDNA microarray was performed to detect difference in gene expression profile induced by BRD7. The results indicated that 21 genes expression were changed after being transfected with BRD7 and the differentially expressed gene including alpha-catenin, cyclinD1, E2F3 was confirmed by western-blot. Next, we found that even though no obvious changes of the total expression of beta-catenin were observed, the accumulation of beta-catenin in nucleus was blocked. In addition, it was found that the expression of beta-catenin was up-regulated in the complex composed of beta-catenin and alpha-catenin in HNE1 cells induction of BRD7. So, we concluded that over-expression of BRD7 increased the expression of alpha-catenin which "hold" beta-catenin in the complex and inhibited its accumulating in nucleus. At last, we demonstrated the c-jun, p-MEK, and p-ERK1/2 expression were down-regulated, and the Ap-1 promoter activity was inactive after being transfected with BRD7. We also found that over-expression of BRD7 can inactivate the c-jun and p-ERK1/2 after being treated with EGF in HNE1 cells. These results indicated that BRD7 played a negative role in ERK1/2 pathway. Taken together, our present results provide new insights for BRD7 function to inhibit NPC cells growth through negative regulating beta-catenin and ERK1/2 pathways.
authors: Cancer Research Institute, Central South University, Changsha, Hunan, China.
authors: Cong
authors: C
authors: Peng
authors: Hua Ying
authors: HY
authors: Liu
authors: Ming
authors: M
authors: Zhou
authors: Li Ming
authors: LM
authors: Zhang
authors: Xiao Ling
authors: XL
authors: Li
authors: Shou Rong
authors: SR
authors: Shen
authors: Gui Yuan
authors: GY
authors: Li
mesh_terms: D002453:Cell Cycle; D002467:Cell Nucleus / Q000378:metabolism; D049109:Cell Proliferation; D002868:Chromosomal Proteins, Non-Histone / Q000502:physiology*; D019938:Cyclin D1 / Q000378:metabolism; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D047468:Immunoprecipitation; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism*; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism*; D008969:Molecular Sequence Data; D009303:Nasopharyngeal Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D009687:Nuclear Proteins / Q000502:physiology*; D020411:Oligonucleotide Array Sequence Analysis; D015398:Signal Transduction; D014158:Transcription, Genetic; D014407:Tumor Cells, Cultured; D051176:beta Catenin / Q000235:genetics / Q000378:metabolism*; D000092468:Bromodomain Containing Proteins
chemical_list: D002868:Chromosomal Proteins, Non-Histone; D019938:Cyclin D1; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D009687:Nuclear Proteins; D051176:beta Catenin; C485694:BRD7 protein, human; D000092468:Bromodomain Containing Proteins