Bag-1 expression in thyroid neoplasm: its correlation with Bcl-2 expression and carcinoma dedifferentiation.
BACKGROUND
Apoptosis, programmed cell death, is one of the promnent factors in the evaluation of carcinoma characteristics. It is well-known that bcl-2 and its related proteins significantly modulate apoptosis. Bag-1 is a recently identified bcl-2-related protein and is known to be linked to the biological aggressiveness of some carcinomas.


METHODS
We immunohistochemically investigated bag-1 and bcl-2 expression in various thyroid neoplasms using monoclonal antibodies.


RESULTS
High bag-1 expression was observed in 66.7% of follicular adenoma and 75.0% of follicular carcinoma, and no statistical difference was established between them. In papillary carcinoma, 60.7% were classified with high bag-1 expression, whereas only 4.5% of anaplastic (undifferentiated) carcinoma highly expressed bag-1, and the incidence was significantly lower (p < 0.0001) than in papillary and follicular carcinomas. Furthermore, in thyroid neoplasm, bag-1 expression was directly linked (p < 0.0001) to bcl-2 expression.


CONCLUSIONS
These findings suggest that bag-1 may interact with bcl-2 to play an important role in thyroid neoplasm before anaplastic transformation, and the disruption of events mediated by bag-1 and bcl-2 may be a typical characteristic of undifferentiated carcinoma.
Ito
Yasuhiro
Y
Department of Surgery, Kuma Hospital, 8-2-35, Shimoyamate-dori, Chuo-ku, Kobe 650-0011, Japan. ito01@kuma-h.or.jp
Yoshida
Hiroshi
H
Nakano
Keiichi
K
Takamura
Yuuki
Y
Miya
Akihiro
A
Kobayashi
Kaoru
K
Yokozawa
Tamotsu
T
Matsuzuka
Fumio
F
Matsuura
Nariaki
N
Kakudo
Kennichi
K
Kuma
Kanji
K
Miyauchi
Akira
A
D018263:Adenocarcinoma, Follicular / Q000378:metabolism / Q000473:pathology; D002291:Carcinoma, Papillary / Q000378:metabolism / Q000473:pathology; D002352:Carrier Proteins / Q000096:biosynthesis*; D002454:Cell Differentiation / Q000502:physiology; D004268:DNA-Binding Proteins; D006801:Humans; D007150:Immunohistochemistry; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000096:biosynthesis*; D013964:Thyroid Neoplasms / Q000378:metabolism* / Q000473:pathology*; D014157:Transcription Factors
C091732:BCL2-associated athanogene 1 protein; D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D014157:Transcription Factors