Promoter hypermethylation and silencing of CHFR mitotic stress checkpoint gene in human gastric cancers.
CHFR is a recently identified mitotic stress check-point gene. CHFR is ubiquitously expressed in normal human tissues, whereas loss of CHFR expression has been observed in human tumors. Silencing of CHFR has been associated with aberrant promoter methylation and histone deacetylation in several cancer types. In this study, we investigated epigenetic CHFR inactivation in human gastric cancers by examining CHFR expression and methylation status in gastric cancer cell lines with RT-PCR analysis, bisulfite PCR and sequencing. A series of primary gastric tumors were also analyzed for CHFR methylation. Eight of 12 (66.7%) gastric cancer cell lines and 19/43 (44.2%) primary gastric tumors showed CHFR methylation. In addition, CpG methylation status correlated well with CHFR expression in the human gastric cancer cell lines, in which treatment with 5-aza-dC resulted in de novo or enhanced expression of CHFR. Combination treatment of 5-aza-dC with trichostatin A showed a synergistic effect on CHFR expression in some cases. Our results indicate that aberrant promoter methylation of the CHFR gene was observed in a significant proportion of human gastric cancers and was responsible for the inactivation of the CHFR gene in gastric cancers.
Kang
Hio Chung
HC
Korean Hereditary Tumor Registry, Cancer Research Institute and Cancer Research Center, Seoul National University, Chongno-gu, Seoul 110-799, Korea.
Kim
Il-Jin
IJ
Park
Jae-Hyun
JH
Shin
Yong
Y
Park
Hye-Won
HW
Ku
Ja-Lok
JL
Yang
Han-Kwang
HK
Lee
Kuhn Uk
KU
Choe
Kuk Jin
KJ
Park
Jae-Gahb
JG
D001483:Base Sequence; D018797:Cell Cycle Proteins / Q000235:genetics*; D045744:Cell Line, Tumor; D003110:Colonic Neoplasms / Q000235:genetics; D019175:DNA Methylation; D017931:DNA Primers; D004273:DNA, Neoplasm / Q000235:genetics*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008938:Mitosis / Q000235:genetics; D009363:Neoplasm Proteins / Q000235:genetics*; D009367:Neoplasm Staging; D000075223:Poly-ADP-Ribose Binding Proteins; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic / Q000235:genetics*; D013274:Stomach Neoplasms / Q000145:classification / Q000235:genetics* / Q000473:pathology; D044767:Ubiquitin-Protein Ligases
D018797:Cell Cycle Proteins; D017931:DNA Primers; D004273:DNA, Neoplasm; D009363:Neoplasm Proteins; D000075223:Poly-ADP-Ribose Binding Proteins; C412002:CHFR protein, human; D044767:Ubiquitin-Protein Ligases