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
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Author |
Takahashi, Sayo
Tokushima University
Okamoto, Koichi
Tokushima University
Tokushima University Educator and Researcher Directory
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Tanahashi, Toshihito
Tokushima University
Fujimoto, Shota
Tokushima University
Bando, Masahiro
Tokushima University
Ma, Beibei
Tokushima University
Miyamoto, Hiroshi
Tokushima University
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Muguruma, Naoki
Tokushima University
Tokushima University Educator and Researcher Directory
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Bando, Yoshimi
Tokushima University
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Sato, Toshiro
Keio University
Fujimori, Takahiro
Shinko Hospital
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Keywords | SSA/P
DNA hypomethylation
S100P
3-dimensional organoid
Genome-wide DNA methylation array
Sessile serrated adenoma/polyp
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Content Type |
Thesis or Dissertation
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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.
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Journal Title |
Digestion
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ISSN | 00122823
14219867
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NCID | AA00628636
AA12781324
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Publisher | Karger
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Volume | 102
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Issue | 5
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Start Page | 789
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End Page | 802
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Published Date | 2021-01-04
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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
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EDB ID | |
DOI (Published Version) | |
URL ( Publisher's Version ) | |
FullText File | |
language |
eng
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TextVersion |
ETD
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MEXT report number | 甲第3486号
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Diploma Number | 甲医第1490号
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Granted Date | 2021-03-17
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Degree Name |
Doctor of Medical Science
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Grantor |
Tokushima University
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departments |
University Hospital
Medical Sciences
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