Quantitative assessment of hTERT mRNA expression in dysplastic nodules of HBV-related hepatocarcinogenesis.
BACKGROUND
Telomerase reverse transcriptase (hTERT) is the rate-limiting determinant of telomerase, which is critical for carcinogenesis. Dysplastic nodules (DNs) appear to be preneoplastic lesions of hepatocellular carcinomas (HCCs). In this study, in order to characterize DNs, hTERT mRNA, hTERT gene dosage, and mRNA for c-myc, a transcriptional activator of hTERT were studied in human multi-step hepatocarcinogenesis.


METHODS
Fifty four hepatic nodules including 5 large regenerative nodules, 14 low-grade DNs, 7 high-grade DNs, 11 DNs with HCC foci and 17 HCCs, 23 livers with chronic hepatitis/cirrhosis, and 6 normal livers were examined. Transcript levels were measured by real-time quantitative RT-PCR and gene dosages by real-time PCR and Southern blotting.


RESULTS
The hTERT mRNA levels increased with the progression of hepatocarcinogenesis, and a significant induction in the transition between low- and high-grade DNs was seen. Most high-grade DNs strongly expressed hTERT mRNA at levels similar to those of HCCs. Twenty-one percent of low-grade DNs had high levels of hTERT mRNA, up to those of high-grade DNs and there was no difference in the pathological features between low-grade DNs with and without increased hTERT mRNA levels. No correlation was found between hTERT mRNA levels, hTERT gene dosage, and c-myc mRNA levels.


CONCLUSIONS
These results suggest that the induction of hTERT mRNA is an important early event and that its measurement by real-time quantitative RT-PCR is a useful tool to detect premalignant/malignant tendencies in hepatic nodules. However, hTERT gene dosage and c-myc expression are not the main mechanisms regulating hTERT expression in hepatocarcinogenesis.
Department of Pathology, Center for Chronic Metabolic Disease Research and Yonsei Biomedical Science and Technology Initiative, Yonsei University College of Medicine, Seoul, Korea.
Bong-Kyeong
BK
Oh
Young-Joo
YJ
Kim
Young Nyun
YN
Park
Jinsub
J
Choi
Kyung Sik
KS
Kim
Chanil
C
Park
D000328:Adult; D000368:Aged; D006528:Carcinoma, Hepatocellular / Q000378:metabolism* / Q000473:pathology / Q000821:virology; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D005260:Female; D018628:Gene Dosage; D006509:Hepatitis B / Q000150:complications*; D006801:Humans; D008099:Liver / Q000378:metabolism / Q000473:pathology; D008107:Liver Diseases / Q000378:metabolism* / Q000473:pathology; D008113:Liver Neoplasms / Q000378:metabolism* / Q000473:pathology / Q000821:virology; D008297:Male; D008875:Middle Aged; D011230:Precancerous Conditions / Q000175:diagnosis / Q000378:metabolism* / Q000473:pathology; D016271:Proto-Oncogene Proteins c-myc / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019098:Telomerase / Q000235:genetics / Q000378:metabolism*
D004268:DNA-Binding Proteins; D016271:Proto-Oncogene Proteins c-myc; D012333:RNA, Messenger; D019098:Telomerase