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ID 115966
Title Alternative
Sessile serrated adenoma/polyp-cancer sequenceにおいてS100Pは遺伝子脱メチル化により発現し、細胞増殖を促進する
Author
Takahashi, Sayo Tokushima University
Tanahashi, Toshihito Tokushima University
Fujimoto, Shota Tokushima University
Bando, Masahiro Tokushima University
Ma, Beibei Tokushima University
Kawaguchi, Tomoyuki Tokushima University
Sato, Toshiro Keio University
Fujimori, Takahiro Shinko Hospital
Keywords
SSA/P
DNA hypomethylation
S100P
3-dimensional organoid
Genome-wide DNA methylation array
Sessile serrated adenoma/polyp
Content Type
Thesis or Dissertation
Description
Background/Aims: Sessile serrated adenomas/polyps (SSA/Ps) are a putative precursor lesion of colon cancer. Although the relevance of DNA hypermethylation in the SSA/P-cancer sequence is well documented, the role of DNA hypomethylation is unknown. We investigated the biological relevance of DNA hypomethylation in the SSA/P-cancer sequence by using 3-dimensional organoids of SSA/P. Methods: We first analyzed hypomethylated genes using datasets from our previous DNA methylation array analysis on 7 SSA/P and 2 cancer in SSA/P specimens. Expression levels of hypomethylated genes in SSA/P specimens were determined by RT-PCR and immunohistochemistry. We established 3-dimensional SSA/P organoids and performed knockdown experiments using a lentiviral shRNA vector. DNA hypomethylation at CpG sites of the gene was quantitated by MassARRAY analysis. Results: The mean number of hypomethylated genes in SSA/P and cancer in SSA/P was 41.6 ± 27.5 and 214 ± 19.8, respectively, showing a stepwise increment in hypomethylation during the SSA/P-cancer sequence. S100P, S100α2, PKP3, and MUC2 were most commonly hypomethylated in SSA/P specimens. The mRNA and protein expression levels of S100P, S100α2, and MUC2 were significantly elevated in SSA/P compared with normal colon tissues, as revealed by RT-PCR and immunohistochemistry, respectively. Among these, mRNA and protein levels were highest for S100P. Knockdown of the S100P gene using a lentiviral shRNA vector in 3-dimensional SSA/P organoids inhibited cell growth by >50% (p < 0.01). The mean diameter of SSA/P organoids with S100P gene knockdown was significantly smaller compared with control organoids. MassARRAY analysis of DNA hypomethylation in the S100P gene revealed significant hypomethylation at specific CpG sites in intron 1, exon 1, and the 5′-flanking promoter region. Conclusion: These results suggest that DNA hypomethylation, including S100P hypomethylation, is supposedly associated with the SSA/P-cancer sequence. S100P overexpression via DNA hypomethylation plays an important role in promoting cell growth in the SSA/P-cancer sequence.
Journal Title
Digestion
ISSN
00122823
14219867
NCID
AA00628636
AA12781324
Publisher
Karger
Volume
102
Issue
5
Start Page
789
End Page
802
Published Date
2021-01-04
Remark
内容要旨・審査要旨・論文本文の公開
本論文は,著者Sayo Takahashiの学位論文として提出され,学位審査・授与の対象となっている。
Rights
© 2020 S. Karger AG, Basel
EDB ID
DOI (Published Version)
URL ( Publisher's Version )
FullText File
language
eng
TextVersion
ETD
MEXT report number
甲第3486号
Diploma Number
甲医第1490号
Granted Date
2021-03-17
Degree Name
Doctor of Medical Science
Grantor
Tokushima University
departments
University Hospital
Medical Sciences