[Expression of BRD7-interacting proteins,BRD2 and BRD3, in nasopharyngeal carcinoma tissues].
OBJECTIVE
BRD7 is a novel gene tightly associated with nasopharyngeal carcinoma(NPC) cloned by cDNA representational difference analysis (cDNA RDA). Two proteins,BRD2 and BRD3, including bromodomain and interacting with BRD7 protein had been screened from human fetal brain cDNA library by yeast two-hybrid system. This study was designed to further identify the interactions of BRD2 and BRD3 with BRD7 respectively and to investigate the expression and action pattern of BRD2 and BRD3 in NPC.


METHODS
BRD2 and BRD3 genes were respectively co-transformed to yeast Y187 with BRD7 gene, then the yeast cotransformers were blotted to nylon membrane. And then the expression of report gene Lac Z by beta-Gal was determined and the interactions of BRD2 and BRD3 proteins with BRD7 protein were identified. Besides,reverse transcription-polymerase chain reaction (RT- PCR) was used to examine the expression of BRD2 and BRD3 genes in normal nasopharyngeal epithelium and NPC biopsies, and to detect the effect of re-expression of BRD7 gene on the expression of BRD2 and BRD3 genes in HNE1 stably transfected BRD7 gene.


RESULTS
The yeast transformers showed all blue by yeast two-hybrid system, which further identified that BRD2 and BRD3 proteins could respectively interact with BRD7 protein. Down-expression or loss of BRD2 and BRD3 genes were detectable in NPC biopsies. The expression levels of BRD2 and BRD3 were increasing with the re-expression of BRD7 gene in HNE1 stably transfected with BRD7.


CONCLUSIONS
BRD7 protein could respectively interact with proteins, BRD2 and BRD3, and BRD7 could up-regulate the expression levels of BRD2 and BRD3 genes in mRNA level to some extent. Each of these three homolog proteins might be capable of forming heteromers with the others, which play important roles in the suppression of growth of NPC cells.
Zhou
Ming
M
Cancer Research Institute, Xiangya School of Medicine, Central South University, Changsha, Hunan, 410078, PR China.
Peng
Cong
C
Nie
Xin-Min
XM
Zhang
Bi-Cheng
BC
Zhu
Shi-Guo
SG
Yu
Ying
Y
Li
Xiao-Ling
XL
Li
Gui-Yuan
GY
D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism*; D018076:DNA, Complementary; D015536:Down-Regulation; D015870:Gene Expression; D006801:Humans; D009303:Nasopharyngeal Neoplasms / Q000378:metabolism*; D009363:Neoplasm Proteins / Q000096:biosynthesis / Q000378:metabolism; D009687:Nuclear Proteins; D016601:RNA-Binding Proteins / Q000096:biosynthesis* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014157:Transcription Factors; D020798:Two-Hybrid System Techniques; D000092468:Bromodomain Containing Proteins
D002868:Chromosomal Proteins, Non-Histone; D018076:DNA, Complementary; D009363:Neoplasm Proteins; D009687:Nuclear Proteins; D016601:RNA-Binding Proteins; D014157:Transcription Factors; C109106:BRD3 protein, human; D000092468:Bromodomain Containing Proteins; C485694:BRD7 protein, human