Hepatocellular carcinoma （HCC） is one of the most common human cancers, and its incidence is still increasing in many countries. The prognosis of HCC patients remains poor, and identification of useful molecular pro...Hepatocellular carcinoma （HCC） is one of the most common human cancers, and its incidence is still increasing in many countries. The prognosis of HCC patients remains poor, and identification of useful molecular prognostic markers is required. Many recent studies have shown that functional alterations of cellcycle regulators can be observed in HCC. Among the various types of cell-cycle regulators, p16 and p27 are frequently inactivated in HCC and are considered to be potent tumor suppressors, p16, a G1-specific cell-cycle inhibitor that prevents the association of cyclindependent kinase （CDK） 4 and CDK6 with cyclin DI, is frequently inactivated in HCC via CpG methylation of its promoter region, p16 may be involved in the early steps of hepatocarcinogenesis, since p16 gene methylation has been detected in subsets of pre-neoplastic liver cirrhosis patients, p27, a negative regulator of the G1-S phase transition through inhibition of the kinase activities of Cdk2/cyclin A and Cdk2/cyclin E complexes, is now considered to be an adverse prognostic factor in HCC. In some cases of HCC with increased cell proliferation, p27 is overexpressed but inactivated by sequestration into cyclin D1-CDK4-containing complexes. Since loss of p16 is closely related to functional inactivation of p27 in HCC, investigating both p16 and p27 may be useful for precise prognostic predictions in individuals with HCC.展开更多
AIM:To investigate cell cycle proteins in chronic hepatitis C virus infection in order to analyze their role in the process of hepatocyte transformation and to characterize their prognostic properties. METHODS:Subject...AIM:To investigate cell cycle proteins in chronic hepatitis C virus infection in order to analyze their role in the process of hepatocyte transformation and to characterize their prognostic properties. METHODS:Subjects of the current study included 50 cases of chronic hepatitis C(CHC) without cirrhosis,30 cases of CHC with liver cirrhosis(LC) ,and 30 cases of hepatitis C-related hepatocellular carcinoma(HCC) admitted to the Department of Hepato-Gastroenterology,Theodor Bilharz Research Institute(TBRI) ,Giza,Egypt.Fifteen wedge liver biopsies,taken during laparoscopic cholecystectomy,were also included as normal controls.Laboratory investigations including urine and stool analysis,liver function tests and prothrombin concentration;serologic markers for viral hepatitis and ultrasonography were done for all cases of the study together with immunohistochemical analysis using primary antibodies against Cyclin D1,Cyclin E,p21,p27 and Rb/p105 proteins. RESULTS:Normal wedge liver biopsies didn't express Cyclin E or Rb/p105 immunostaining but show positive staining for Cyclin D1,p21 and p27.Cyclin D1 expressed nuclear staining that was sequentially increased from CHC to LC(P<0.01) to HCC(P<0.001) cases;meanwhile,Cyclin E revealed nuclear positivity only in the case of HCCs patients that was directly correlated to Rb/p105 immuno-reactivity.The expression of p21 and p27 was significantly increased in CHC and LC cases compared to normal controls and HCCs with no significant difference between well-and poorlydifferentiated tumors.p21 showed only a nuclear pattern of staining,while,p27 presented with either cytoplasmic and/or nuclear reactivity in all studied cases.Correlation analysis revealed a direct relation between Cyclin D1 and p21 in CHC cases(P<0.001) ,between Cyclin D1 and Cyclin E in HCCs(P<0.01);however,an inverserelationship was detected between Cyclin D1 and p21 or p27(P<0.001) and between p21 and Rb/p105(P<0.05) in HCCs. CONCLUSION:Upregulation of Cyclin D1 in CHC plays a vital role in the development and differentiation of HCC;while,Cyclin E may be a useful marker for monitoring tumor behavior.p21 and p27 can be used as predictive markers for HCC.Furthermore,higher expression of Rb/p105 as well as inverse relation with p21 and histologic grades suggests its important role in hepatic carcinogenesis.展开更多
AIM We have previously reported that inducible over-expresaion of Bak may prolong cell cycle in G1 phase and lead to apoptosis in HCC-9204 cells. This study is to investigate whether p27KIP1 plays an important role in...AIM We have previously reported that inducible over-expresaion of Bak may prolong cell cycle in G1 phase and lead to apoptosis in HCC-9204 cells. This study is to investigate whether p27KIP1 plays an important role in this process. MEHODS In order to elucidate the exact function of p27KIP1 in this process, a zinc inducible p27KIP1 stable transfectant and transient p27KIP1- GFP fusion transfectant were constructed. The effects of inducible p27KIP1 on cell growth, cell cycle arrest and apoptosis were examined in the mock, control pMD vector, and pMD-KIP1 transfected HCC-9204 cells. RESULTS This p27KIP1-GFP transfectant may transiently express the fusion gene. The cell growth was reduced by 35% at 48 h of p27KIP1 induction with zinc treatment as determined by trypan blue exclusion assay. These differences remained the same after 72 h of p27KIP1 expression, p27KIP1 caused cell cycle arrest after 24 h of induction, with 40% increase in G1 population. Prolonged p27KIP1 expression in this cell line induced apoptotic cell death reflected by TUNEL assay. Fourty-eight h and 72 h of p27KIP1 expression showed a characteristic DNA ladder on agarose gel electrophoresis.展开更多
AIM： To study the expressions of p27^kip1 protein and p27mRNA, the hypermethylation of p27^kip1 and the relation between them in various stages of hepatocarcinogenesis. METHODS： p27 protein and p27mRNA were detected...AIM： To study the expressions of p27^kip1 protein and p27mRNA, the hypermethylation of p27^kip1 and the relation between them in various stages of hepatocarcinogenesis. METHODS： p27 protein and p27mRNA were detected by immunohistochemical staining and in situ hybridization respectively in 68 cases of normal liver, liver cirrhosis, pericancerous cirrhosis and hepatocellular carcinoma （HCC）. The hypermethylation of p27^kip1 was detected by methylation-specific PCR （MSP） in 44 cases of normal liver, liver cirrhosis, and HCC. RESULTS： The positive rate of p27 protein was 66.7% （4/6） in normal liver, 60.0% （6/10） in liver cirrhosis, 50.0% （12/24） in pericancerous cirrhosis and 21.4% （6/28） in HCC. There were no statistical differences in normal liver, liver cirrhosis and pericancerous cirrhosis, but the positive rate of p27 protein significantly decreased in HCC compared to that in the other groups （P = 0.006, %2 = 7.664）. The positive rate of p27^kip1 mRNA was 83.3% （5/6） in normal liver, 70.0% （7/10） in liver cirrhosis, 75.0% （18/24） in pericancerous cirrhosis and 25.0% （7/28） in HCC. There were no statistical differences in normal liver, liver cirrhosis and pericancerous cirrhosis, but the positive rate of p27^kip1 mRNA also significantly decreased in HCC compared to that in the other groups （P = 0.000, %2 = 16.600）. In addition, there was a significant correlation between the expression of p27 protein and p27mRNA in the integrated group of normal liver and liver cirrhosis. However, no significant correlation was found between pericancerous cirrhosis and HCC. Using MSP, we found that 1 HCC in 44 cases （including 6 cases of normal liver, 10 cases of liver cirrhosis and 28 cases of HCC） was methylated, whose p27 protein and p27mRNA were negative. CONCLUSION： The reduction or loss of p27 protein and p27mRNA are potentially involved in hepatocarcinogenesis. The hypermethylation of p27 might lead to the loss of p27mRNA transcription.展开更多
文摘Hepatocellular carcinoma （HCC） is one of the most common human cancers, and its incidence is still increasing in many countries. The prognosis of HCC patients remains poor, and identification of useful molecular prognostic markers is required. Many recent studies have shown that functional alterations of cellcycle regulators can be observed in HCC. Among the various types of cell-cycle regulators, p16 and p27 are frequently inactivated in HCC and are considered to be potent tumor suppressors, p16, a G1-specific cell-cycle inhibitor that prevents the association of cyclindependent kinase （CDK） 4 and CDK6 with cyclin DI, is frequently inactivated in HCC via CpG methylation of its promoter region, p16 may be involved in the early steps of hepatocarcinogenesis, since p16 gene methylation has been detected in subsets of pre-neoplastic liver cirrhosis patients, p27, a negative regulator of the G1-S phase transition through inhibition of the kinase activities of Cdk2/cyclin A and Cdk2/cyclin E complexes, is now considered to be an adverse prognostic factor in HCC. In some cases of HCC with increased cell proliferation, p27 is overexpressed but inactivated by sequestration into cyclin D1-CDK4-containing complexes. Since loss of p16 is closely related to functional inactivation of p27 in HCC, investigating both p16 and p27 may be useful for precise prognostic predictions in individuals with HCC.
基金Supported by Theodor Bilharz Research Institute(Grant# 74D) in collaboration with the American University of Cairo
文摘AIM:To investigate cell cycle proteins in chronic hepatitis C virus infection in order to analyze their role in the process of hepatocyte transformation and to characterize their prognostic properties. METHODS:Subjects of the current study included 50 cases of chronic hepatitis C(CHC) without cirrhosis,30 cases of CHC with liver cirrhosis(LC) ,and 30 cases of hepatitis C-related hepatocellular carcinoma(HCC) admitted to the Department of Hepato-Gastroenterology,Theodor Bilharz Research Institute(TBRI) ,Giza,Egypt.Fifteen wedge liver biopsies,taken during laparoscopic cholecystectomy,were also included as normal controls.Laboratory investigations including urine and stool analysis,liver function tests and prothrombin concentration;serologic markers for viral hepatitis and ultrasonography were done for all cases of the study together with immunohistochemical analysis using primary antibodies against Cyclin D1,Cyclin E,p21,p27 and Rb/p105 proteins. RESULTS:Normal wedge liver biopsies didn't express Cyclin E or Rb/p105 immunostaining but show positive staining for Cyclin D1,p21 and p27.Cyclin D1 expressed nuclear staining that was sequentially increased from CHC to LC(P<0.01) to HCC(P<0.001) cases;meanwhile,Cyclin E revealed nuclear positivity only in the case of HCCs patients that was directly correlated to Rb/p105 immuno-reactivity.The expression of p21 and p27 was significantly increased in CHC and LC cases compared to normal controls and HCCs with no significant difference between well-and poorlydifferentiated tumors.p21 showed only a nuclear pattern of staining,while,p27 presented with either cytoplasmic and/or nuclear reactivity in all studied cases.Correlation analysis revealed a direct relation between Cyclin D1 and p21 in CHC cases(P<0.001) ,between Cyclin D1 and Cyclin E in HCCs(P<0.01);however,an inverserelationship was detected between Cyclin D1 and p21 or p27(P<0.001) and between p21 and Rb/p105(P<0.05) in HCCs. CONCLUSION:Upregulation of Cyclin D1 in CHC plays a vital role in the development and differentiation of HCC;while,Cyclin E may be a useful marker for monitoring tumor behavior.p21 and p27 can be used as predictive markers for HCC.Furthermore,higher expression of Rb/p105 as well as inverse relation with p21 and histologic grades suggests its important role in hepatic carcinogenesis.
文摘AIM We have previously reported that inducible over-expresaion of Bak may prolong cell cycle in G1 phase and lead to apoptosis in HCC-9204 cells. This study is to investigate whether p27KIP1 plays an important role in this process. MEHODS In order to elucidate the exact function of p27KIP1 in this process, a zinc inducible p27KIP1 stable transfectant and transient p27KIP1- GFP fusion transfectant were constructed. The effects of inducible p27KIP1 on cell growth, cell cycle arrest and apoptosis were examined in the mock, control pMD vector, and pMD-KIP1 transfected HCC-9204 cells. RESULTS This p27KIP1-GFP transfectant may transiently express the fusion gene. The cell growth was reduced by 35% at 48 h of p27KIP1 induction with zinc treatment as determined by trypan blue exclusion assay. These differences remained the same after 72 h of p27KIP1 expression, p27KIP1 caused cell cycle arrest after 24 h of induction, with 40% increase in G1 population. Prolonged p27KIP1 expression in this cell line induced apoptotic cell death reflected by TUNEL assay. Fourty-eight h and 72 h of p27KIP1 expression showed a characteristic DNA ladder on agarose gel electrophoresis.
基金Supported by the Natural Science Foundation of Yunnan Province, China, No. 2000C0058M, and Scientific Research Foundation of the Education Department of Yunnan Province, No. 0011010
文摘AIM： To study the expressions of p27^kip1 protein and p27mRNA, the hypermethylation of p27^kip1 and the relation between them in various stages of hepatocarcinogenesis. METHODS： p27 protein and p27mRNA were detected by immunohistochemical staining and in situ hybridization respectively in 68 cases of normal liver, liver cirrhosis, pericancerous cirrhosis and hepatocellular carcinoma （HCC）. The hypermethylation of p27^kip1 was detected by methylation-specific PCR （MSP） in 44 cases of normal liver, liver cirrhosis, and HCC. RESULTS： The positive rate of p27 protein was 66.7% （4/6） in normal liver, 60.0% （6/10） in liver cirrhosis, 50.0% （12/24） in pericancerous cirrhosis and 21.4% （6/28） in HCC. There were no statistical differences in normal liver, liver cirrhosis and pericancerous cirrhosis, but the positive rate of p27 protein significantly decreased in HCC compared to that in the other groups （P = 0.006, %2 = 7.664）. The positive rate of p27^kip1 mRNA was 83.3% （5/6） in normal liver, 70.0% （7/10） in liver cirrhosis, 75.0% （18/24） in pericancerous cirrhosis and 25.0% （7/28） in HCC. There were no statistical differences in normal liver, liver cirrhosis and pericancerous cirrhosis, but the positive rate of p27^kip1 mRNA also significantly decreased in HCC compared to that in the other groups （P = 0.000, %2 = 16.600）. In addition, there was a significant correlation between the expression of p27 protein and p27mRNA in the integrated group of normal liver and liver cirrhosis. However, no significant correlation was found between pericancerous cirrhosis and HCC. Using MSP, we found that 1 HCC in 44 cases （including 6 cases of normal liver, 10 cases of liver cirrhosis and 28 cases of HCC） was methylated, whose p27 protein and p27mRNA were negative. CONCLUSION： The reduction or loss of p27 protein and p27mRNA are potentially involved in hepatocarcinogenesis. The hypermethylation of p27 might lead to the loss of p27mRNA transcription.
