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author:("Fan, nishi")
1.  New Insights into FAK Phosphorylation Based on a FAT Domain-Defective Mutation 
PLoS ONE  2014;9(9):e107134.
Mounting evidence suggests that the FAK N-terminal (FERM) domain controls FAK phosphorylation and function; however, little is known regarding the role of the C terminal (FAT) domain in FAK regulation. We identified a patient-derived FAK mutant, in which a 27-amino acid segment was deleted from the C-terminal FAT domain (named FAK-Del33). When FAK-Del33 was overexpressed in specific tumor cell lines, Y397 phosphorylation increased compared with that observed in cells expressing FAK-WT. Here, we attempt to unveil the mechanism of this increased phosphorylation. Using cell biology experiments, we show that FAK-Del33 is incapable of co-localizing with paxillin, and has constitutively high Y397 phosphorylation. With a kinase-dead mutation, it showed phosphorylation of FAK-Del33 has enhanced through auto-phosphorylation. It was also demonstrated that phosphorylation of FAK-Del33 is not Src dependent or enhanced intermolecular interactions, and that the hyperphosphorylation can be lowered using increasing amounts of transfected FERM domain. This result suggests that Del33 mutation disrupting of FAT's structural integrity and paxillin binding capacity leads to incapable of targeting Focal adhesions, but has gained the capacity for auto-phosphorylation in cis.
PMCID: PMC4166415  PMID: 25226367
2.  TRIB2 acts downstream of Wnt/TCF in liver cancer cells to regulate YAP and C/EBPα function 
Molecular cell  2013;51(2):211-225.
Dysregulation of Wnt signaling is closely associated with human liver tumorigenesis. However, liver cancer-specific Wnt transcriptional programs and downstream effectors remain poorly understood. Here, we identify tribbles homolog 2 (TRIB2) as a direct target of Wnt/TCF in liver cancer, and demonstrate that transcription of Wnt target genes, including TRIB2, is coordinated by the TCF and FoxA transcription factors in liver cancer cells. We show that Wnt-TRIB2 activation is critical for cancer cell survival and transformation. Mechanistically, TRIB2 promotes protein stabilization of the YAP transcription coactivator through interaction with the βTrCP ubiquitin ligase. Furthermore, we find that TRIB2 relieves the liver tumor suppressor protein C/EBPα-mediated inhibition of YAP/TEAD transcriptional activation in liver cancer cells. Altogether, our study uncovers a novel regulatory mechanism underlying liver cancer-specific Wnt transcriptional output, and suggests that TRIB2 functions as a signaling nexus to integrate the Wnt/βCatenin, Hippo/YAP and C/EBPα pathways in cancer cells.
PMCID: PMC4007693  PMID: 23769673
3.  Correction: Serum Starvation Induces DRAM Expression in Liver Cancer Cells via Histone Modifications within Its Promoter Locus 
PLoS ONE  2013;8(6):10.1371/annotation/cd548ece-6f43-4837-9936-7f5d282c17b8.
PMCID: PMC3692950
4.  Serum Starvation Induces DRAM Expression in Liver Cancer Cells via Histone Modifications within Its Promoter Locus 
PLoS ONE  2012;7(12):e50502.
DRAM is a lysosomal membrane protein and is critical for p53-mediated autophagy and apoptosis. DRAM has a potential tumor-suppressive function and is downregulated in many human cancers. However, the regulation of DRAM expression is poorly described so far. Here, we demonstrated that serum deprivation strongly induces DRAM expression in liver cancer cells and a core DNA sequence in the DRAM promoter is essential for its responsiveness to serum deprivation. We further observed that euchromatin markers for active transcriptions represented by diacetyl-H3, tetra-acetyl-H4 and the trimethyl-H3K4 at the core promoter region of DRAM gene are apparently increased in a time-dependent manner upon serum deprivation, and concomitantly the dimethyl-H3K9, a herterochromatin marker associated with silenced genes, was time-dependently decreased. Moreover, the chromatin remodeling factor Brg-1 is enriched at the core promoter region of the DRAM gene and is required for serum deprivation induced DRAM expression. These observations lay the ground for further investigation of the DRAM gene expression.
PMCID: PMC3520922  PMID: 23251372
5.  NF-kappaB P50/P65 hetero-dimer mediates differential regulation of CD166/ALCAM expression via interaction with micoRNA-9 after serum deprivation, providing evidence for a novel negative auto-regulatory loop 
Nucleic Acids Research  2011;39(15):6440-6455.
CD166/ALCAM plays an important role in tumor aggression and progression as well as protecting cancer cells against apoptosis and autophagy. However, the mechanism by which pro-cell death signals control CD166 expression remains unclear. Here we show that following serum deprivation (SD), upregulation of CD166 protein is shorter than that of CD166 mRNA. Molecular analysis revealed both CD166 and miR-9-1 as two novel NF-κB target genes in hepatoma cells. In vivo activation and translocation of the NF-κB P50/P65 hetero-dimer into the nucleus following the phosphorylation and accompanied degradation of its inhibitor, IκBα, contributes to efficient transcription of both genes following SD. We show that following serum starvation, delayed up-regulation of miR-9 represses translation of CD166 protein through its target sites in the 3′-UTR of CD166 mRNA. We also propose that miR-9 promotes cell migration largely due to inhibition of CD166. Collectively, the study elucidates a novel negative auto-regulatory loop in which NF-κB mediates differential regulation of CD166 after SD.
PMCID: PMC3159468  PMID: 21572107
6.  CREB up-regulates long non-coding RNA, HULC expression through interaction with microRNA-372 in liver cancer 
Nucleic Acids Research  2010;38(16):5366-5383.
Long non-coding RNA (lncRNA), highly up-regulated in liver cancer (HULC) plays an important role in tumorigenesis. Depletion of HULC resulted in a significant deregulation of several genes involved in liver cancer. Although up-regulation of HULC expression in hepatocellular carcinoma has been reported, the molecular mechanisms remain unknown. In this study, we used in vivo and in vitro approaches to characterize cancer-dependent alterations in the chromatin organization and find a CREB binding site (encompassing from −67 to −53 nt) in the core promoter. Besides, we also provided evidence that PKA pathway may involved in up-regulation of HULC. Furthermore, we demonstrated HULC may act as an endogenous ‘sponge’, which down-regulates a series of microRNAs (miRNAs) activities, including miR-372. Inhibition of miR-372 leads to reducing translational repression of its target gene, PRKACB, which in turn induces phosphorylation of CREB. Over-expression of miR-372 decreases the association of CREB with the proximal promoter, followed by the dissociation of P300, resulting in a change of the histone ‘code’, such as in deacetylation and methylation. The study elucidates that fine tuning of HULC expression is part of an auto-regulatory loop in which it’s inhibitory to expression and activity of miR-372 allows lncRNA up-regulated expression in liver cancer.
PMCID: PMC2938198  PMID: 20423907
7.  Hepatitis C Virus Targets Over-Expression of Arginase I in Hepatocarcinogenesis 
Hepatitis C virus (HCV) infection is often associated with chronic liver disease, which is a major risk factor for the development of hepatocellular carcinoma (HCC). To study the HCV-host cell relationship on the molecular level, HepG2 and Huh7 cells were stably transfected with an infectious cDNA clone of HCV or with empty vector. Evidence for HCV replication was obtained in both culture systems. HCV also stimulated growth in vitro. To identify genes whose altered expression by HCV are important to the pathogenesis of infection, RNAs were isolated from HepG2-HCV and HepG2-vector cells, and subjected to microarray analysis. The results showed that arginase 1 mRNA and protein were elevated about 3-fold in HCV positive compared to negative cells (P < 0.01). Arginase 1 expression was elevated in more than 75% of HCV infected liver samples compared to paired HCC from the same patients (> 33% positive) and to uninfected liver tissues (0% positive). Arginase 1 specific siRNA inhibited the ability of HCV to stimulate hepatocellular growth in culture by > 70%, suggesting that the metabolism of arginine to ornithine may contribute to HCV mediated stimulation of hepatocellular growth. Introduction of arginase specific siRNA also resulted in increased nitric oxide synthase (iNOS) (>1.2 fold), nitric oxide (NO) production (> 3 fold) and increased cell death (>2.5-fold) in HCV positive compared to negative cells, suggesting that these molecules potentially contribute to hepatocellular damage. Hence, an important part of the mechanism whereby HCV regulates hepatocellular growth and survival may be through altering arginine metabolism.
PMCID: PMC2701904  PMID: 19253371
arginine; arginase 1; hepatocellular carcinoma; hepatitis C virus; nitric oxide
8.  Community-based study on CKD subjects and the associated risk factors 
Nephrology Dialysis Transplantation  2009;24(7):2117-2123.
Background. The study was performed to investigate the prevalence, awareness and the risk factors of chronic kidney disease (CKD) in the community population in Shanghai, China.
Methods. A total of 2596 residents were randomly recruited from the community population in Shanghai, China. All were screened for albuminuria, haematuria, morning spot urine albumin-to-creatinine ratio and renal function. Serum creatinine, uric acid, cholesterol, triglyceride and haemoglobin were assessed. A simplified MDRD equation was used to estimate the glomerular filtration rate (eGFR). All studied subjects were screened by kidney ultrasound. Haematuria, if present in the morning spot urine dipstick test, was confirmed by microscopy. The associations among the demographic characteristics, health characteristics and indicators of kidney damage were examined.
Results. Two thousand five hundred and fifty-four residents (n = 2554), after giving informed consent and with complete data, were entered into this study. Albuminuria and haematuria were detected in 6.3% and 1.2% of all the studied subjects, respectively, whereas decreased kidney function was found in 5.8% of all studied subjects. Approximately 11.8% of subjects had at least one indicator of kidney damage. The rate of awareness of CKD was 8.2%. The logistic regression model showed that age, central obesity, hypertension, diabetes, anaemia, hyperuricaemia and nephrolithiasis each contributed to the development of CKD.
Conclusion. This is the first Shanghai community-based epidemiological study data on Chinese CKD patients. The prevalence of CKD in the community population in Shanghai is 11.8%, and the rate of awareness of CKD is 8.2%. All the factors including age, central obesity, hypertension, diabetes, anaemia, hyperuricaemia and nephrolithiasis are positively correlated with the development of CKD in our studied subjects.
PMCID: PMC2698090  PMID: 19193736
awareness; chronic kidney disease; epidemiology; prevalence; risk factors

Results 1-8 (8)