Expression of G2-M modulators in thyroid neoplasms: correlation of cyclin A, B1 and cdc2 with differentiation.
Previous studies have demonstrated that cell proliferating activity accurately reflects the biological aggressiveness of thyroid neoplasms. In this study, we focused on the G2-M boundary regulators of the cell cycle and investigated the expression of three proteins, cyclin A, cyclin B1 and cdc2. The incidence of cyclin A overexpression was significantly linked to carcinoma differentiation (p < 0.0001) and, in particular, all 21 cases of undifferentiated carcinoma overexpressed this protein. On the other hand, cyclin B1 was overexpressed in four undifferentiated carcinomas (19.0%), but not in carcinomas of other types. Cdc2 overexpression was also related to carcinoma differentiation (p < 0.0001), and was directly linked to cyclin A overexpression (p < 0.0001), but not to cyclin B1 overexpression. No significant relationship could be established between the overexpression of these proteins and the histological type of follicular tumor. These results suggest that cyclin A, rather than cyclin B1, contributes significantly to the aggressive character of thyroid carcinoma, together with cdc2.
Ito
Yasuhiro
Y
Department of Surgery, Kuma Hospital, Kobe, Japan. ito01@kuma-h.or.jp
Yoshida
Hiroshi
H
Nakano
Keiichi
K
Takamura
Yuuki
Y
Kobayashi
Kaoru
K
Yokozawa
Tamotsu
T
Matsuzuka
Fumio
F
Matsuura
Nariaki
N
Kuma
Kanji
K
Miyauchi
Akira
A
D000236:Adenoma / Q000378:metabolism* / Q000473:pathology; D016203:CDC2 Protein Kinase / Q000096:biosynthesis*; D002277:Carcinoma / Q000378:metabolism* / Q000473:pathology; D002455:Cell Division; D019925:Cyclin A / Q000096:biosynthesis*; D019926:Cyclin B / Q000096:biosynthesis*; D056744:Cyclin B1; D006801:Humans; D007124:Immunoenzyme Techniques; D019394:Ki-67 Antigen / Q000378:metabolism; D013964:Thyroid Neoplasms / Q000378:metabolism* / Q000473:pathology
C534699:CCNB1 protein, human; D019925:Cyclin A; D019926:Cyclin B; D056744:Cyclin B1; D019394:Ki-67 Antigen; D016203:CDC2 Protein Kinase