Overexpression of Polo-like kinase 1 is a common and early event in pancreatic cancer.
BACKGROUND
There is abundant evidence from in vivo and in vitro studies that Polo-like kinase 1 (PLK1) plays a crucial role in the regulation of proliferative activity of normal and malignant cells. Therefore, PLK1 has been proposed as a new target for antineoplastic treatment strategies.


METHODS
We conducted an immunohistochemical expression study for PLK1 on 86 cases of pancreatic adenocarcinoma as well as on 5 cases of chronic pancreatitis. Additionally, we investigated the correlation of PLK1 expression levels with clinicopathological data and patient survival.


RESULTS
PLK1 was found overexpressed in pancreatic neoplasia as early as in pancreatic intraepithelial neoplasia III lesions, whereas benign acinar pancreatic parenchyma and ductal epithelia showed only focal PLK1 positivity. Invasive pancreatic adenocarcinomas were PLK1 positive in 47.7% of cases. No correlation of PLK1 positivity and the extent of tumour spread was evident, nor did PLK1 expression correlate with tumour grade or patient prognosis. Prognostic factors in our study cohort were nodal status and tumour grade.


CONCLUSIONS
The fact that half of the invasive pancreatic carcinomas strongly overexpressed PLK1 indicates that inhibition of this mitotic key regulator might represent a rewarding approach in the treatment of early and late pancreatic carcinoma.
Weichert
Wilko
W
Institute of Pathology, Charité University Hospital, Berlin, Germany. wilko.weichert@charite.de
Schmidt
Mathias
M
Jacob
Juliane
J
Gekeler
Volker
V
Langrehr
Jan
J
Neuhaus
Peter
P
Bahra
Marcus
M
Denkert
Carsten
C
Dietel
Manfred
M
Kristiansen
Glen
G
D000230:Adenocarcinoma / Q000378:metabolism / Q000401:mortality / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002278:Carcinoma in Situ / Q000378:metabolism* / Q000401:mortality / Q000473:pathology; D018797:Cell Cycle Proteins / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000378:metabolism* / Q000401:mortality / Q000473:pathology; D011379:Prognosis; D011494:Protein Kinases / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D016019:Survival Analysis; 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