Expression and cellular localization of p8 protein in thyroid neoplasms.
OBJECTIVE
p8 protein has mitogenic activity and is linked to the development of pancreatic carcinoma. However, little is known about the expression and physiological significance of this protein in other human carcinomas.


METHODS
In this study, we immunohistochemically investigated p8 expression in thyroid neoplasms as well as in the normal thyroid gland.


RESULTS
p8 was expressed in normal follicular cells, but no normal thyroid was regarded as overexpressing p8. On the other hand, 44.3% of papillary carcinoma overexpressed p8 and the incidence was directly linked to the tumor size (p=0.0340) and lymph node metastasis (p=0.0145). In follicular tumors, the incidence of p8 overexpression did not depend on histological type. In anaplastic (undifferentiated) carcinoma, p8 was overexpressed only in 5.0%, which was significantly lower than in papillary (p=0.0006) and follicular carcinomas (p=0.0049). In normal follicules and follicular tumors, p8 was localized mainly in the nucleus except for two adenomas. On the other hand, p8 localization was more cytoplasmic in papillary carcinoma larger than 1.0 cm (p=0.0186) and with a poorly differentiated lesion (p=0.0313).


CONCLUSIONS
These results suggest that the overexpression and cytoplasmic localization of p8 protein may reflect disease progression of papillary carcinoma, whereas this protein plays little part in thyroid carcinoma after anaplastic transformation.
Ito
Yasuhiro
Y
Department of Surgery, Kuma Hospital, 8-2-35, Shimoyamate-Dori, Chuo ku, Kobe City 650-0011, Japan. ito01@kuma-h.or.jp
Yoshida
Hiroshi
H
Motoo
Yoshiharu
Y
Miyoshi
Eiji
E
Iovanna
Juan Lucio
JL
Tomoda
Chisato
C
Uruno
Takashi
T
Takamura
Yuuki
Y
Miya
Akihiro
A
Kobayashi
Kaoru
K
Matsuzuka
Fumio
F
Matsuura
Nariaki
N
Kuma
Kanji
K
Miyauchi
Akira
A
D018263:Adenocarcinoma, Follicular / Q000378:metabolism / Q000473:pathology; D000236:Adenoma / Q000378:metabolism / Q000473:pathology; D051792:Basic Helix-Loop-Helix Proteins; D014408:Biomarkers, Tumor / Q000378:metabolism; D002277:Carcinoma / Q000378:metabolism / Q000473:pathology; D002291:Carcinoma, Papillary / Q000378:metabolism / Q000473:pathology; D002467:Cell Nucleus / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D006609:High Mobility Group Proteins / Q000378:metabolism; D006801:Humans; D007124:Immunoenzyme Techniques; D008207:Lymphatic Metastasis / Q000473:pathology; D009361:Neoplasm Invasiveness; D009363:Neoplasm Proteins; D021381:Protein Transport; D013961:Thyroid Gland / Q000378:metabolism / Q000473:pathology; D013964:Thyroid Neoplasms / Q000378:metabolism* / Q000473:pathology
D051792:Basic Helix-Loop-Helix Proteins; D014408:Biomarkers, Tumor; D004268:DNA-Binding Proteins; D006609:High Mobility Group Proteins; D009363:Neoplasm Proteins; C491643:NUPR1 protein, human