Proteomic analysis of EZH2 downstream target proteins in hepatocellular carcinoma.
Enhancer of zeste homolog 2 (EZH2) is suggested to be a potential therapeutic target and a diagnostic marker for cancer. Our previous study also showed the critical role of EZH2 in hepatocellular carcinoma (HCC) tumorigenesis. The present study is aimed at revealing the comprehensive downstream pathways of EZH2 by functional proteomic profiling. Lentivirus mediated RNA interference (RNAi) was employed to knockdown EZH2 in HCC cells. The 2-DE was employed to compare the expression profile difference between parental and EZH2-knockdown HCC cells. In total, 28 spots were differentially expressed during EZH2 inhibition. Among all, 18 proteins were identified by PMF with MALDI-TOF MS. Western blotting further validated upregulation of 60S acidic ribosomal protein P0 (L10E), and downregulation of two proteins with EZH2 inhibition: stathmin1 and probable protein disulfide isomerase (PDI) ER-60 precursor (ERp57). Moreover, L10E was downregulated with overexpression of EZH2 in hepatocytes, and L10E reversed the effect of EZH2 on cell proliferation, suggesting it a downstream target of EZH2. The comprehensive and comparative analyses of proteins associated with EZH2 could further our understanding on the downstream signal cascade of EZH2 leading to tumorigenesis.
Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Shatin, Hong Kong.
Yangchao
Y
Chen
Marie Chia-mi
MC
Lin
Hua
H
Wang
Chu-yan
CY
Chan
Lei
L
Jiang
Sai Ming
SM
Ngai
Jun
J
Yu
Ming-liang
ML
He
Pang-Chui
PC
Shaw
David T
DT
Yew
Joseph J
JJ
Sung
Hsiang-fu
HF
Kung
D006528:Carcinoma, Hepatocellular / Q000378:metabolism* / Q000473:pathology; D002460:Cell Line; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D004268:DNA-Binding Proteins / Q000032:analysis* / Q000378:metabolism*; D030562:Databases, Protein; D000071221:Enhancer of Zeste Homolog 2 Protein; D005562:Formazans / Q000378:metabolism; D020869:Gene Expression Profiling; D005822:Genetic Vectors; D006801:Humans; D016086:Lentivirus / Q000235:genetics; D008113:Liver Neoplasms / Q000378:metabolism* / Q000473:pathology; D063151:Polycomb Repressive Complex 2; D040901:Proteomics / Q000379:methods*; D034622:RNA Interference; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013778:Tetrazolium Salts / Q000378:metabolism; D014157:Transcription Factors / Q000032:analysis* / Q000378:metabolism*
D004268:DNA-Binding Proteins; D005562:Formazans; D013778:Tetrazolium Salts; D014157:Transcription Factors; C079782:MTT formazan; C498409:EZH2 protein, human; D000071221:Enhancer of Zeste Homolog 2 Protein; D063151:Polycomb Repressive Complex 2