REG I enhances chemo‐ and radiosensitivity in squamous cell esophageal cancer cells

• Published in: Cancer science 2008-12, Vol.99 (12), p.2491-2495
• Main Authors: Hayashi, Kaori, Motoyama, Satoru, Koyota, Souichi, Koizumi, Yukio, Wang, Jingshu, Takasawa, Shin, Itaya‐Hironaka, Asako, Sakuramoto‐Tsuchida, Sumiyo, Maruyama, Kiyotomi, Saito, Hajime, Minamiya, Yoshihiro, Ogawa, Jun‐ichi, Sugiyama, Toshihiro
• Format: Article
• Language: English
• Subjects: Antimetabolites, Antineoplastic - metabolism; Antimetabolites, Antineoplastic - therapeutic use; Biological and medical sciences; Carcinoma, Squamous Cell - drug therapy; Carcinoma, Squamous Cell - genetics; Carcinoma, Squamous Cell - metabolism; Carcinoma, Squamous Cell - pathology; Carcinoma, Squamous Cell - radiotherapy; Cell Line, Tumor; Cell Proliferation - drug effects; Cell Proliferation - radiation effects; Dose-Response Relationship, Radiation; Esophageal Neoplasms - drug therapy; Esophageal Neoplasms - genetics; Esophageal Neoplasms - metabolism; Esophageal Neoplasms - pathology; Esophageal Neoplasms - radiotherapy; Fluorouracil - metabolism; Fluorouracil - therapeutic use; Formazans - metabolism; Humans; Lithostathine - genetics; Lithostathine - metabolism; Medical sciences; Original; Proteins - metabolism; Radiation Tolerance - genetics; RNA, Messenger - metabolism; Tetrazolium Salts - metabolism; Transfection; Tumors
• ISSN: 1347-9032; 1349-7006; 1349-7006
• DOI: 10.1111/j.1349-7006.2008.00980.x

Identification of reliable markers of chemo‐ and radiosensitivity and the key molecules that enhance the susceptibility of squamous esophageal cancer cells to anticancer treatments would be highly desirable. To test whether regenerating gene (REG) I expression enhances chemo‐ and radiosensitivity in esophageal squamous cell carcinoma cells, we used MTT (3‐[4,5‐dimethylthiazol‐2‐yl]‐2,5‐diphenyltetrazolium bromide) assays to compare the chemo‐ and radiosensitivities of untransfected TE‐5 and TE‐9 cells with those of cells stably transfected with REG Iα and Iβ. We then used flow cytometry to determine whether REG I expression alters cell cycle progression. No REG I mRNA or protein were detected in untransfected TE‐5 and TE‐9 cells. Transfection with REG Iα and Iβ led to strong expression of both REG I mRNA and protein in TE‐5 and TE‐9 cells, which in turn led to significant increases in both chemo‐ and radiosensitivity. Cell cycle progression was unaffected by REG I expression. REG I thus appears to enhance the chemo‐ and radiosensitivity of squamous esophageal cancer cells, which suggests that it may be a useful target for improved and more individualized treatments for patients with esophageal squamous cell carcinoma. (Cancer Sci 2008; 99: 2491–2495)