Chromosomal instability, telomere shortening, and inactivation of p21(WAF1/CIP1) in dysplastic nodules of hepatitis B virus-associated multistep hepatocarcinogenesis.
Systemic analysis for chromosomal instability and inactivation of cell cycle checkpoints are scarce during hepatocarcinogenesis. We studied 24 patients with chronic B viral cirrhosis including 30 cirrhotic regenerative nodules, 35 low-grade dysplastic nodules, 15 high-grade dysplastic nodules, 7 dysplastic nodules with hepatocellular carcinoma foci, and 18 hepatocellular carcinomas. Eight normal livers were studied as the control group. Telomere length and micronuclei were detected by Southern blot and Feulgen-fast green dyeing technique, respectively, and p21(WAF1/CIP1) expression was studied by immunohistochemistry. Micronuclei >1 per 3000 hepatocytes were found in 17% of low-grade dysplastic nodules, 87% of high-grade dysplastic nodules, and 100% of high-grade dysplastic nodules with hepatocellular carcinoma foci and hepatocellular carcinomas in contrast to those of all normal livers, and 90% of cirrhosis showed no micronuclei. The micronuclei index showed a gradual increase during hepatocarcinogenesis and there was a significant increase between cirrhosis and low-grade dysplastic nodules, low-grade dysplastic nodules and high-grade dysplastic nodules, and high-grade dysplastic nodules and hepatocellular carcinomas. Telomere length showed a gradual shortening during hepatocarcinogenesis and a significant reduction was found in high-grade dysplastic nodules (P=0.024) and hepatocellular carcinomas (P=0.031) compared with normal and cirrhotic livers. The micronuclei index was correlated with telomere shortening (P=0.016). The p21(WAF1/CIP1) labeling index was significantly higher in cirrhosis than in normal livers (P=0.024) and markedly decreased in low-grade dysplastic nodules, high-grade dysplastic nodules, and hepatocellular carcinomas compared with cirrhosis (P<0.05). The p21(WAF1/CIP1) labeling index was associated with telomere length (P<0.001) but not micronuclei index. This study shows that telomere shortening, chromosomal instability, and inactivation of p21(WAF1/CIP1) checkpoint function occur in low-grade dysplastic nodules as well as in high-grade dysplastic nodules, and their cooperation is considered to be critical for malignant transformation during hepatitis B virus associated-multistep hepatocarcinogenesis.
Lee
Yoon Hee
YH
Department of Pathology, Institute of Gastroenterology, Brain Korea 21 Project for Medical Science, Center for Chronic Metabolic Disease, Yonsei University College of Medicine, Seoul, Korea.
Oh
Bong-Kyeong
BK
Yoo
Jeong Eun
JE
Yoon
So-Mi
SM
Choi
Jinsub
J
Kim
Kyung Sik
KS
Park
Young Nyun
YN
D000328:Adult; D015139:Blotting, Southern; D006528:Carcinoma, Hepatocellular / Q000235:genetics* / Q000473:pathology / Q000821:virology; D002471:Cell Transformation, Neoplastic / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D043171:Chromosomal Instability; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000235:genetics / Q000378:metabolism*; D005260:Female; D015870:Gene Expression; D020869:Gene Expression Profiling; D020868:Gene Silencing; D019694:Hepatitis B, Chronic / Q000150:complications / Q000235:genetics* / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D008113:Liver Neoplasms / Q000235:genetics* / Q000473:pathology / Q000821:virology; D008297:Male; D048629:Micronuclei, Chromosome-Defective; D008875:Middle Aged; D011230:Precancerous Conditions / Q000235:genetics* / Q000473:pathology / Q000821:virology; D016615:Telomere / Q000473:pathology*
C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21