Document Detail

DNA methylation and histone modifications cause silencing of Wnt antagonist gene in human renal cell carcinoma cell lines.
MedLine Citation:
PMID:  18404682     Owner:  NLM     Status:  MEDLINE    
Secreted frizzled-related protein 2 (sFRP2) is a negative modulator of the Wingless-type (Wnt) signaling pathway, and shown to be inactivated in renal cell carcinoma (RCC). However, the molecular mechanism of silencing of sFRP2 is not fully understood. Our study was designed to elucidate the silencing mechanism of sFRP2 in RCC. Expression of sFRP2 was examined in 20 pairs of primary cancers by immunohistochemistry. Kidney cell lines (HK-2, Caki-1, Caki-2, A-498 and ACHN) were analyzed for sFRP2 expression using real-time RT-PCR and Western blotting. The methylation status at 46 CpG sites of the 2 CpG islands in the sFRP2 promoter was characterized by bisulfite DNA sequencing. Histone modifications were assessed by chromatin immunoprecipitation (ChIP) assay using antibodies against AcH3, AcH4, H3K4 and H3K9. sFRP2 was frequently repressed in primary cancers and in RCC cells. The majority of sFRP2 negative cells had a methylated promoter. Meanwhile, sFRP2 expression was repressed by a hypomethylated promoter in Caki-1 cells, and these cells had a repressive histone modification at the promoter. In Caki-1 cells, sFRP2 was reactivated by trichostatin A (TSA). Repressive histone modifications were also observed in RCC cells with hypermethylated promoters, but sFRP2 was reactivated only by 5-aza-2'-deoxycytidine (DAC) and not by TSA. However, the activation of the silenced sFRP2 gene could be achieved in all cells using a combination of DAC and TSA. This is the first report indicating that aberrant DNA methylation and histone modifications work together to silence the sFRP2 gene in RCC cells.
Ken Kawamoto; Hiroshi Hirata; Nobuyuki Kikuno; Yuichiro Tanaka; Masayuki Nakagawa; Rajvir Dahiya
Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural; Research Support, U.S. Gov't, Non-P.H.S.    
Journal Detail:
Title:  International journal of cancer. Journal international du cancer     Volume:  123     ISSN:  1097-0215     ISO Abbreviation:  Int. J. Cancer     Publication Date:  2008 Aug 
Date Detail:
Created Date:  2008-06-03     Completed Date:  2008-07-03     Revised Date:  2014-09-13    
Medline Journal Info:
Nlm Unique ID:  0042124     Medline TA:  Int J Cancer     Country:  United States    
Other Details:
Languages:  eng     Pagination:  535-42     Citation Subset:  IM    
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MeSH Terms
Antimetabolites, Antineoplastic / pharmacology
Apoptosis / genetics
Azacitidine / analogs & derivatives,  pharmacology
Blotting, Western
Carcinoma, Renal Cell / genetics,  metabolism*
Cell Line, Tumor
CpG Islands / genetics
DNA Methylation*
DNA Modification Methylases / antagonists & inhibitors
Enzyme Inhibitors / pharmacology
Gene Expression Regulation, Neoplastic / drug effects
Gene Silencing* / drug effects
Histone Deacetylase Inhibitors
Histones / metabolism*
Hydroxamic Acids / pharmacology
Immunohistochemistry / methods
Kidney Neoplasms / genetics,  metabolism*
Membrane Proteins / genetics*
Promoter Regions, Genetic
RNA, Messenger / metabolism
Reverse Transcriptase Polymerase Chain Reaction
Signal Transduction / drug effects
Wnt Proteins / metabolism*
Grant Support
Reg. No./Substance:
0/Antimetabolites, Antineoplastic; 0/Enzyme Inhibitors; 0/Histone Deacetylase Inhibitors; 0/Histones; 0/Hydroxamic Acids; 0/Membrane Proteins; 0/RNA, Messenger; 0/SFRP2 protein, human; 0/Wnt Proteins; 3X2S926L3Z/trichostatin A; 776B62CQ27/decitabine; EC 2.1.1.-/DNA Modification Methylases; M801H13NRU/Azacitidine

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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