[Expression of DNA-PK in hepato- and cholangio-neoplasms and its significance].
OBJECTIVE
To characterize DNA-PKcs and Ku70 expressions in hepato- and cholangio-neoplastic tissues and the association with the degree of malignancy and invasiveness of the tumors.


METHODS
The expression of DNA-PKcs and Ku70 was examined in 47 cases of hepato- or cholangio-neoplasm by immunohistochemistry.


RESULTS
Ku70 was expressed in all of the neoplastic tissues examined and with a little variation in levels. The highest expression was observed in adenocarcinomas and adenomas. There was no statistically significant association between Ku70 expression level and the degree of their malignancy extent or invasiveness. In contrast to Ku 70, a wide variation in expression levels of DNA-Pkcs was observed among different types of neoplastic tissues. The highest ratio of positive expressing cells was detected in hepatocellular carcinomas (92.1%), which was significantly higher than that in cholangioadeno carcinomas (65.3%) and biliary cystadenocarcinomas (51.9%). Low or no expression level was detected in papillary adenoma cases. DNA-PKcs expression of invasive adenomas and adeno-carcinomas (61.2%) was significantly higher than that of non-invasive adenomas and adeno-carcinomas (30.4%). There was no expression observed in the normal tissues adjacent to the tumors.


CONCLUSIONS
DNA-PKcs is expressed in hepato- and cholangio-neoplasms and its variable level of expression is associated with the types of the tumor and their degree of malignancy and invasiveness. DNA-PKcs could be recognized as a new biomarker for liver neoplasm.
Yu
Zi-jian
ZJ
Beijing Institute of Radiation Medicine, Beijing 100850, China.
Sui
Jian-guo
JG
Ding
Ying-qin
YQ
Cao
Zhen-shan
ZS
Zhou
Ping-kun
PK
Wu
De-chang
DC
D000230:Adenocarcinoma / Q000201:enzymology; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D034961:Antigens, Nuclear / Q000096:biosynthesis / Q000235:genetics; D001650:Bile Duct Neoplasms / Q000201:enzymology*; D001653:Bile Ducts, Intrahepatic / Q000201:enzymology; D014408:Biomarkers, Tumor / Q000096:biosynthesis* / Q000235:genetics; D006528:Carcinoma, Hepatocellular / Q000201:enzymology*; D051747:DNA-Activated Protein Kinase / Q000096:biosynthesis* / Q000235:genetics; D004268:DNA-Binding Proteins / Q000096:biosynthesis / Q000235:genetics; D005260:Female; D006801:Humans; D000072200:Ku Autoantigen; D008113:Liver Neoplasms / Q000201:enzymology*; D008297:Male; D008875:Middle Aged
D034961:Antigens, Nuclear; D014408:Biomarkers, Tumor; D004268:DNA-Binding Proteins; D051747:DNA-Activated Protein Kinase; C000606509:Xrcc6 protein, human; D000072200:Ku Autoantigen