TY - JOUR
T1 - Loss of MAL expression in precancerous lesions of the esophagus
AU - Mimori, Koshi
AU - Nishida, Kohjiro
AU - Nakamura, Yoshito
AU - Ieta, Keisuke
AU - Yoshikawa, Yasuji
AU - Sasaki, Atsushi
AU - Ishii, Hideshi
AU - Alonso, Miguel A.
AU - Mori, Masaki
N1 - Funding Information:
We thank Ms. M. Oda and Ms. T. Shimooka for their technical support and Dr. K. Obara for his advice for the regarding pathological information. We also appreciate the cooperation of Drs. Kosaka and Motoyama. Financial support: This work was supported by the following grant sponsors: CREST; Japan Science and Technology Agency (JST); Japan Society for the Promotion of Science (JSPS) Grants-in-Aid for Scientific Research (Grant nos. 17109013, 17591411, 17591413, and 17015032).
PY - 2007/5
Y1 - 2007/5
N2 - Background: We have identified a novel function of MAL (T-cell differentiation-related gene) as a candidate suppressor gene in esophageal cancer. As the role of MAL expression in esophageal carcinogenesis is as yet undetermined, MAL expression in a rat multi-step carcinogenic model and in precancerous lesions of the human esophagus was investigated. Microarray analysis between MAL-transfectant and control cells was also carried out to clarify how MAL confers its anti-tumor effects. Materials and Methods: (1) In the rat model, MAL expression levels in laser microdissected normal esophageal epithelium, dysplastic tissues and carcinoma tissues were examined by reverse transcription (RT)-PCR. (2) Immunostaining with MAL antibody was performed in 10 dysplastic lesions adjacent to cancer in six cases of esophageal cancer. (3) We established a MAL transfectant using a Tet-off vector in esophageal cancer cells and performed microarray analysis under MAL-positive and MAL-negative conditions. Results: (1) In the rat model, MAL mRNA expression was observed only in the normal samples. (2) MAL expression was observed distinctively in differentiated or keratinized normal tissues and was not observed in either dysplastic lesions or carcinoma tissue. (3) Up-regulated genes in MAL-positive cells included keratin 18 (transfectant/control = 2.94) and keratin 10 (t/c = 2.82). Conclusion: MAL expression was lost in dysplastic lesions of the rat carcinoma model as well as the human esophagus. The up-regulated keratins revealed by microarray analysis and the strong staining of the differentiated normal tissues in immunohistochemical study support the role of MAL as a regulator of differentiation in esophageal epithelium.
AB - Background: We have identified a novel function of MAL (T-cell differentiation-related gene) as a candidate suppressor gene in esophageal cancer. As the role of MAL expression in esophageal carcinogenesis is as yet undetermined, MAL expression in a rat multi-step carcinogenic model and in precancerous lesions of the human esophagus was investigated. Microarray analysis between MAL-transfectant and control cells was also carried out to clarify how MAL confers its anti-tumor effects. Materials and Methods: (1) In the rat model, MAL expression levels in laser microdissected normal esophageal epithelium, dysplastic tissues and carcinoma tissues were examined by reverse transcription (RT)-PCR. (2) Immunostaining with MAL antibody was performed in 10 dysplastic lesions adjacent to cancer in six cases of esophageal cancer. (3) We established a MAL transfectant using a Tet-off vector in esophageal cancer cells and performed microarray analysis under MAL-positive and MAL-negative conditions. Results: (1) In the rat model, MAL mRNA expression was observed only in the normal samples. (2) MAL expression was observed distinctively in differentiated or keratinized normal tissues and was not observed in either dysplastic lesions or carcinoma tissue. (3) Up-regulated genes in MAL-positive cells included keratin 18 (transfectant/control = 2.94) and keratin 10 (t/c = 2.82). Conclusion: MAL expression was lost in dysplastic lesions of the rat carcinoma model as well as the human esophagus. The up-regulated keratins revealed by microarray analysis and the strong staining of the differentiated normal tissues in immunohistochemical study support the role of MAL as a regulator of differentiation in esophageal epithelium.
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U2 - 10.1245/s10434-006-9064-2
DO - 10.1245/s10434-006-9064-2
M3 - Article
C2 - 17151798
AN - SCOPUS:34249029023
SN - 1068-9265
VL - 14
SP - 1670
EP - 1677
JO - Annals of Surgical Oncology
JF - Annals of Surgical Oncology
IS - 5
ER -
