14-3-3 sigma possibly plays a constitutive role in papillary carcinoma, but not in follicular tumor of the thyroid.
14-3-3 sigma is a negative regulator of the cell cycle and contributes to G2 arrest. Thus far, the lack of its expression due to hypermethylation of the CpG islands has been reported in some carcinomas. In this study, we investigated the expression of 14-3-3 sigma in thyroid neoplasms by means of immunohistochemistry as well as Western blot analysis. Normal follicules did not express 14-3-3 sigma. In 82 papillary carcinomas, all the cases expressed 14-3-3 sigma and its expression was not reduced but even enhanced in the advanced stage and in poorly differentiated types. Furthermore, 21 of the 23 anaplastic carcinomas expressed 14-3-3 sigma and its expression level tended to be higher than in papillary carcinoma. On the other hand, none of the 34 follicular carcinomas or 29 follicular adenomas expressed 14-3-3 sigma. These results suggest that 14-3-3 sigma plays a constitutive role in papillary carcinoma rather than acting as a cell cycle regulator, whereas it is not required for the occurrence and development of follicular tumor.
Department of Surgery, Kuma Hospital, 8-2-35, Shimoyamate-dori, Chuo-ku, Kobe 650-0011, Japan. ito01@kuma-h.or.jp
Yasuhiro
Y
Ito
Eiji
E
Miyoshi
Erika
E
Uda
Hiroshi
H
Yoshida
Takashi
T
Uruno
Yuuki
Y
Takamura
Akihiro
A
Miya
Kaoru
K
Kobayashi
Fumio
F
Matsuzuka
Nariaki
N
Matsuura
Kennichi
K
Kakudo
Kanji
K
Kuma
Akira
A
Miyauchi
D048948:14-3-3 Proteins; D018263:Adenocarcinoma, Follicular / Q000378:metabolism* / Q000473:pathology; D014408:Biomarkers, Tumor / Q000378:metabolism* / Q000502:physiology; D002291:Carcinoma, Papillary / Q000378:metabolism* / Q000473:pathology; D005092:Exonucleases / Q000378:metabolism* / Q000502:physiology; D005095:Exoribonucleases; D006801:Humans; D007150:Immunohistochemistry; D009363:Neoplasm Proteins / Q000378:metabolism* / Q000502:physiology; D013964:Thyroid Neoplasms / Q000378:metabolism* / Q000473:pathology
D048948:14-3-3 Proteins; D014408:Biomarkers, Tumor; D009363:Neoplasm Proteins; D005092:Exonucleases; D005095:Exoribonucleases; C413442:SFN protein, human