The role of Zinc Finger Protein 146 in Liver Cancer M.M.Y. Waye 1,2 , T.L. Yeung 1,2 , J.L. Zhu 1,2 1 The Chinese University of Hong Kong, 2 Croucher Laboratory for Human Genomics Background/aims: The aim of this research project is the characterization of a Krüppel zinc finger protein, zinc Finger Protein 146 (ZNF146) using hepatocellular carcinoma as a disease model. Zinc finger protein 146 (ZNF146), also named as Only Zinc Fingers protein (OZF), is a 33kDa nuclear zinc finger protein consisting solely of ten C2H2 zinc finger motifs of the Krüppel type. Like most of Krüppel proteins, it is assumed to be the transcription factor and involved in the regulation of gene expression. The ZNF146 gene is amplified in 15-25% of pancreatic carcinomas and overexpressed in more than half of the tumors including liver cancer. It is thus proposed that overexpression of the ZNF146 may contribute to the development or progression of hepatocellular carcinoma. Methods: We used flow cytometry, microarray, green fluorescent recombinant protein, RT-PCR site-directed mutagenesis, and transfection to study the effect of expression of ZNF146. Results: Our results shown that ZNF146 was over-expressed in two human HCC cell lines HepG2 and Hep3B. Expression profiles of ZNF146 over-expressing shown that genes related to the p53 tumor suppressor activity or DNA damage, repair response and control were deregulated upon overexpression of ZNF146. Conclusions: ZNF146 is possibly involved in liver carcinogenesis by affecting DNA repair and cell cycle control upon induced DNA damage. Background: In the present study, we reported the establishment of a real-time monitor system for directly observing the catalytic, kinetic characteristics of DNAzyme 10-23 in vitro cleavage on the target RNA molecules as well as for rapid, accurate, high-throughout evaluation of varied DNAzymes on their counterpart RNA molecules. Methods: DNAzyme named Dz-HCV-9 specific to hepatitis C virus (HCV) ORF AUG were designed and synthesized. Dz-HCV-Mis-9 with mismatched substrate-recognition domains, Dz-HCV-Mut-9 with mutant catalytic domains, antisense oligonucleotide ASON and nonsense oligonucleotide NSON were synthesized respectively as controls. A chimeric oligonucleotide of 29nt containing both RNA and DNA bases was designed and synthesized as the substrate: 5' FAM-GT AGACCGUGCACCAUGAGCACGAAUCCT-BHQ 3', corresponding to the330-354 nt (underline) of HCV genome(gi: 329873) The reporter FAM/BHQ was incorporated at the 5' and 3' end, respectively. Under simulated physiological conditions (37 ), kinetic characterization of RNA-cleaving DNAzyme was analyzed in a real-time way. Factors that influencing DNAzyme cleavage were analyzed. Results: Dz-HCV-9 specific to HCV ORF AUG could cleave target RNA at A•U site, a continuous change of fluorescence intensity was monitored. While the control oligonucleotides couldn't cleave RNA, there were no change of fluorescence intensity. Factors that influencing DNAzyme cleavage concluded different substrate-recognition domain, Mg 2+ concentration and pH. Conclusion: A real-time monitoring system for kinetic characterization of RNA-cleaving DNAzyme was successfully established in the first time.