maspin遺伝子の異常発現は，プロモーター領域のdemethylationによって生じる．さらに，これらの異常は化生性の変化や異型度の高い腫瘍部分で生じていることが明らかとなった． DNAメチル化は細胞の形態学的変化と密接な関連があり，その機構が破綻することは悪性腫瘍の形成に大きく関与していることが明らかとなった． 業績 Ogasawara S, Maesawa C, Yamamoto M, Akiyama Y, Wada K, Fujisawa K, Higuchi T, Tomisawa Y, Sato N, Endo S, Saito K, Masuda T. Disruption of cell-type-specific methylation at the Maspin gene promoter is frequently involved in undifferentiated thyroid cancers. Oncogene 23: 1117-1124, 2004. Wada K, Maesawa C, Akasaka T, Masuda T. Aberrant expression of the maspin gene associated with epigenetic modification in melanoma cells. J Invest Dermatol 122: 805-811, 2004. Fujisawa K, Maesawa C, Sato R, Wada K, Ogasawara S, Akiyama Y,　Takeda M, Fujita T, Otsuka K, Higuchi T, Suzuki K, Saito K, Masuda T. Epigenetic status and aberrant expression of the maspin gene in human hepato-biliary tract carcinomas. Lab Invest 85: 214-224, 2005. Terashima M, Maesawa C, Oyama K, Ohtani S, Akiyama Y, Ogasawara S, Takagane A, Saito K, Masuda T, Kanzaki N, Matsuyama S, Hoshino Y, Kogure M, Gotoh M, Shirane M, Mori K. Gene expression profiles in human gastric cancer: expression of maspin correlates with lymph node metastasis. Br J Cancer 92: 1130-1136, 2005. Maesawa C, Ogasawara S, Yashima-Abo A, Kimura T, Kotani K, Masuda S, Nagata Y, Iwaya T, Suzuki K, Oyake T, Akiyama Y, Kawamura H, Masuda T. Aberrant maspin expression in gallbladder epithelium is associated with intestinal metaplasia in patients with cholelithiasis. J Clin Pathol 59: 328-330, 2006.