The Expression Of Gankyrin In Chronic Hepatitis, Cirrhosis And Hepatocellular Carcinoma And It's Clinicopathological Significance

Object To investigate the mechanism of Gankyrin in chronic inflammation and malignant transformation on hepatocyte, and to evaluate the significance in clinicopathological diagnosis and therapy.Materials and methods A total of 404 hepatic tissue samples were selected as follows:In the first cohort,194 consecutive hepatocellular carcinoma (HCC) tissue samples and matched peri-carcinomatous tissues with complete follow-up data were selected from January 2000 to December 2005. In the second cohort, 118 HCC tissue samples were selected under randomized method from January 2006 to December 2008. In all these 312 HCC samples,49 samples with dysplastic nodules(DN)were detected, and another cohort of 58 DN samples were selected under randomized method from july 2004 to December 2009. In the last cohort,33 cavernous hemangioma of liver samples with normal hepatic tissue were selected under randomized method in 2009. Totally, all 312 samples of HCC with matched peri-carcinomatous tissues,107 samples of DN and 33 samples of normal hepatic tissues as normal control were obtained. All these patients were under surgical resection in the general hospital of PLA. All samples were examined by immunohistochemical staining to investigate the relationship between Gankyrin expression level and the clinicopathologic characters. Another cohort of 23 fresh surgical resected samples were under Westernblot and RT-PCR examination. Soft agar assay, immigration test, flat plate clone formation assay and growth curve were performed to determine the ability of Gankyrin in malignant transformation of hepatocyte. Finally, the activity of NF-kB was detected with or without TNF-a in condition of interfereing or overexpressing Gankyrin.Results 1. Gankyrin was overexpressed in the cytoplasm and nuclear of HCCs and DNs, moderately expressed in the cytoplasm of peri-carcinomatous tissues, but did not expressed in normal hepatic tissues. All groups (except HCCs and DNs) had significant difference with each other (p= 0.000).2. Gankyrin levels of different peri-carcinomatous tissue groups were significantly different accordiong to the inflammation status(p< 0.01) except for levels between chronic hepatitis and cirrhosis group(p= 0.094).3. In the all 312 HCC samples, Gankyrin expression level in nuclear was significantly correlated with introhepatic metastasis(p= 0.03745) and the inflammation status of peri-carcinomatous tissues(p= 0.0399). Total Gankyrin expression level was significantly correlated with the inflammation status of matched peri-carcinomatous tissues (p= 0.03489) and the expression level of Top-Ⅱα(p= 0.03091). The expression level of Gankyrin in cytoplasm was only significantly correlated with that of Top-Ⅱα(p= 0.03091).4. The expression level of Gankyrin had no significant correlation with the prognosis of HCC.5. Westernblot and RT-PCR showed high protein and mRNA level of Gankyrin in HCC and peri-carcinomatous tissues.6. In HepG2 cell line, interfere with Gankyrin resulted in down regulation of the clonality and reproductive activity, but had no effect on immigration.7. Gankyrin could inhibit the activity of NF-kB with or without TNF-a.Conclusion 1. Gankyrin has the malignant transformational ability on hepatocyte, and can promote the proliferation of HCC.2. The cancergenesis promotion of Gankyrin on hepatocyte occurs at early stage of HCC, but not the progressive stage.3. The subcellular expressive position of Gankyrin can be an important differential diagnostic protein between hyperplasy and atypical hyperplasy.4. Gankyrin might also participate in hepatic chronic inflammation process involving TNF-αand NF-k B pathway.