[A study of the gene encoding Ki-67 antigen in human pancreatic cancer using non-radioactive in situ hybridization and immunohistochemistry].
OBJECTIVE
To investigate, at transcriptional and translational level in situ, the abnormal gene expression of the Ki-67 protein in pancreatic carcinoma specimens.


METHODS
40 pancreatic cancer specimens, 5 normal pancreatic and 4 chronic pancreatitis tissues were studied. A 435 bp cDNA fragment located in codon 2, exon 13 of the Ki-67 antigen gene was amplified by the polymerase chain reaction (PCR). The DIG-labeled cRNA probes were transcribed using a commercially available DIG RNA labeling kit. Localization of the Ki-67 protein and the specific mRNA were studied by combining immunohistochemistry (ICH) with (DIG)-labeled in situ hybridization (ISH).


RESULTS
The Ki-67 protein mRNA in formalin-fixed and paraffin-embedded pancreatic tissue sections was successfully localized. Analyzing the Ki-67 mRNA transcription in 17 pancreatic cancer specimens with Ki-67 ICH labeling index > 20%, we found that stronger mRNA signals were also observed in poorly differentiated specimens with Ki-67 index > 50% than in those well differentiated with ICH labeling index 20% - 50%. A high expression of both mRNA and protein was observed in poorly differentiated pancreatic adenocarcinomas.


CONCLUSIONS
Abnormal overexpression of the gene encoding Ki-67 protein was detected not only at the protein level, but also at the mRNA level in pancreatic tumors. The abnormal overexpression of the Ki-67 protein might be correlated with the central part, exon 13, of the gene.
Wu
Y
Y
Surgical Laboratory, Second Affiliated Hospital of Zhejiang Medical University, Hangzhou 310009.
Peng
S
S
Sheng
H
H
D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006367:HeLa Cells; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization / Q000379:methods; D019394:Ki-67 Antigen / Q000032:analysis / Q000235:genetics*; D008297:Male; D010190:Pancreatic Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism
D019394:Ki-67 Antigen; D012333:RNA, Messenger