Delta Np73 expression in thyroid neoplasms originating from follicular cells.
OBJECTIVE
p73, a homologue of p53, is known as a negative regulator of tumour progression. However, delta Np73, an isoform of p73 lacking the NH2-terminal transactivation domain plays an oncogenic role by interfering with the activity of p53 and TA (full-length transactivating isoforms) p73. In this study, we investigated the expression of delta Np73 in human thyroid neoplasms originating from follicular cells.


METHODS
We immunohistochemically investigated delta Np73 expression in 223 thyroid neoplasms. Delta Np73 expression level was evaluated as the sum of positivity score and intensity score.


RESULTS
Normal follicular cells did not express delta Np73, but 27.3% of follicular adenoma, 85.4% of follicular carcinoma, 99.2% of papillary carcinoma, and 95.7% of anaplastic carcinoma were positive for the transcript. Delta Np73 expression level did not differ between widely invasive and minimally invasive follicular carcinomas. In papillary carcinoma, the level was inversely linked to tumour size, extrathyroid extension, and clinically apparent metastasis. Furthermore, in anaplastic carcinoma, delta Np73 expression level was significantly lower than that in papillary carcinoma.


CONCLUSIONS
Our findings indicate that delta Np73 plays a role predominantly in the early phase of papillary carcinoma progression.
Ito
Yasuhiro
Y
Department of Surgery, Kuma Hospital, Kobe, Japan. ito01@kuma-h.or.jp
Uramoto
Hidetaka
H
Funa
Keiko
K
Yoshida
Hiroshi
H
Jikuzono
Tomoo
T
Asahi
Shuji
S
Higashiyama
Takuya
T
Tomoda
Chisato
C
Takamura
Yuuki
Y
Miya
Akihiro
A
Kobayashi
Kaoru
K
Matsuzuka
Fumio
F
Kuma
Kanji
K
Miyauchi
Akira
A
D018263:Adenocarcinoma, Follicular / Q000378:metabolism* / Q000556:secondary; D000236:Adenoma / Q000378:metabolism* / Q000473:pathology; D000368:Aged; D014408:Biomarkers, Tumor / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D018450:Disease Progression; D006801:Humans; D007124:Immunoenzyme Techniques; D009687:Nuclear Proteins / Q000378:metabolism*; D013961:Thyroid Gland / Q000378:metabolism* / Q000473:pathology; D013964:Thyroid Neoplasms / Q000378:metabolism* / Q000473:pathology; D025521:Tumor Suppressor Proteins / Q000378:metabolism*
D014408:Biomarkers, Tumor; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D025521:Tumor Suppressor Proteins