Polo-like kinase 1 expression in medullary carcinoma of the thyroid: its relationship with clinicopathological features.
OBJECTIVE
Polo-like kinase 1 (PLK1) is one of the serine-threonine kinases that contributes to cell mitosis and is regarded as a marker of cellular proliferation. However, its protein expression in human carcinoma has not been studied in depth. In this study, we investigated PLK1 expression in medullary thyroid carcinoma by means of immunohistochemistry.


METHODS
We immunohistochemically investigated PLK1 expression in 67 cases of medullary thyroid carcinoma.


RESULTS
The PLK1 expression level was elevated in 43 of the 67 cases (64.1%). Furthermore, the expression level was directly linked to lymph node metastasis, advanced stage and male sex. All patients who were negative for PLK1 expression are currently alive without tumor recurrence, while 6 of the 43 PLK1-positive patients showed recurrence and 3 have already died of this disease.


CONCLUSIONS
These findings suggest that PLK1 expression significantly reflects aggressive characteristics of medullary thyroid carcinoma.
Ito
Yasuhiro
Y
Kuma Hospital, Kobe, and Department of Pathology, Wakayama Medical University, Japan. ito01@kuma-h.or.jp
Nakamura
Yasushi
Y
Yoshida
Hiroshi
H
Tomoda
Chisato
C
Uruno
Takashi
T
Takamura
Yuuki
Y
Miya
Akihiro
A
Kobayashi
Kaoru
K
Matsuzuka
Fumio
F
Kuma
Kanji
K
Kakudo
Kennichi
K
Miyauchi
Akira
A
D000293:Adolescent; D000328:Adult; D000368:Aged; D018276:Carcinoma, Medullary / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D007564:Japan; D008198:Lymph Nodes / Q000473:pathology; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D012008:Recurrence; D012189:Retrospective Studies; D012737:Sex Factors; D013964:Thyroid Neoplasms / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D000097869:Polo-Like Kinase 1
D018797:Cell Cycle Proteins; D011494:Protein Kinases; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D000097869:Polo-Like Kinase 1