胃と腸47巻13号

2012年12月発行

今月の主題 右側大腸腫瘍の臨床病理学的特徴

主題研究

遺伝子背景からみた大腸癌の左右差

著者： 岡本泰幸¹² 安炳九³ 近藤豊⁴

所属機関： ¹名古屋市立大学大学院医学研究科消化器・代謝内科学 ^{2 3}赤穂市民病院外科 ⁴愛知県がんセンター研究所分子腫瘍学部

ページ範囲：P.1983 - P.1988

文献概要

要旨　近年の大腸癌の発癌機構に関する研究から，大腸癌の発生経路には，マイクロサテライト不安定性（microsatellite instability ; MSI）や染色体不安定性（chromosomal instability ; CIN）に加えて，エピゲノム異常が関与していることが明らかになってきた．MSI陽性大腸癌は，右側大腸に好発し予後良好である．一方，CIN陽性の大腸癌は，様々な遺伝子の変異が介在していることから，多様な臨床像を呈する．エピゲノム異常に起因する大腸癌のうちCIMP（CpG island methylator phenotype）は，右側結腸に好発し，BRAFの変異を伴う予後のよいCIMP1/CIMP-HとK-rasの変異を伴い予後の悪いCIMP2/CIMP-lowが存在する．さらに左側結腸のDNAメチル化異常は，主に加齢によりDNAメチル化の影響を受けやすい遺伝子がDNAメチル化していることが明らかとなった．これらのゲノム・エピゲノム異常が，左右大腸癌での異なる病理像や形態学，臨床経過に影響を及ぼしていると考える．

参考文献

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