Expression and significance of new inhibitor of apoptosis protein survivin in hepatocellular carcinoma

AM: To investigate expression and significance of inhibitor of apoptosis protein survivin in hepatocellular carcinoma (HCC). METHODS: The expression of survivin and vascular endothelial growth factor (VEGF) was investigated in 38 cases of HCC tissues and 38 liver cirrhosis tissues by immunohistochemistry and Western blot. The relationship between the expression of survivin and clinicopathological factors of HCC was analyzed. RESULTS: Survivin protein was detected in 23 (60.5%) of 38 HCCs and 3 (7.9%) of 38 liver cirrhosis tissues. In 23 cases of HCC which expressed survivin, the expression of VEGF was positive in 18 cases and slight positive or negative in 5 cases. While in 15 cases of HCC which did not express survivin, 12 cases did not express or slightly expressed, and 3 cases expressed VEGF. In liver cirrhosis tissues, the expression of VEGF was as follows: 24 cases were negative, 10 cases were weak positive and 4 cases were strong positive. The expression of survivin was coincident with the expression of VEGF in HCC (P<0.01). The expression of survivin in HCC had no relationship with the patients' age, gender, tumor size and differentiation level of HCC, while it was related to the metastasis of HCC. The protein quantitative analysis by Western blot also showed that overexpression of survivin in HCC was closely correlated to the expression of VEGF (P<0.01). Furthermore, stronger expression of survivin and VEGF was also found in patients with metastasis rather than in those with no metastasis (P<0.01). CONCLUSION: Survivin plays a pivotal role in the metastasis of HCC, and it has some correlation with tumorigenesis. The expression of survivin in the primary lesion is very useful as an indicator for metastasis and prognosis of HCC. It could become a new target of gene therapy of HCC.     

生存素、p27和PTEN在肝细胞癌中的表达及临床病理意义

目的 探讨生存素蛋白、生存素mRNA、p27蛋白、p27 mRNA和第10号染色体同源丢失性磷酸酶张力蛋白基因(PTEN)蛋白在肝细胞癌(HCC)中的表达及其临床病理意义.方法 自制组织芯片,采用免疫组织化学和原位杂交法检测生存素蛋白、p27蛋白、PTEN蛋白和生存素mRNA、p27 mRNA在141份肝细胞癌、128份癌旁肝组织、97份远癌肝组织及17份正常肝组织中的表达,探讨各指标的关系并建立预测肝癌发生的模型.结果 肝癌组中生存素蛋白(Ridit值的95%CI为0.689±0.048,P《0.01)、生存素mRNA(Ridit值的95% CI为0.690±0.049,P《0.01)和p27蛋白(Ridit值的95% CI为0.556±0.053,P《0.05)表达明显增高,PTEN(Ridit值的95% CI为0.282±0.048)表达明显下降(P《0.01);肝癌中生存素的表达与p27、PTEN表达均显著相关;生存素mRNA、p27蛋白和PTEN蛋白对判断肝癌发生与否有重要意义.结论 生存素mRNA、p27蛋白的表达上调和PTEN蛋白的表达下调可作为判断肝癌发生的有价值指标.     

Survivin expression in early hepatocellular carcinoma and post-treatment with anti-cancer drug under hypoxic culture condition

AIM:To investigate the expression of survivin during the early stages of hepatocellular carcinoma(HCC). METHODS:Immunohistochemical expression of survivin in liver tumor and non-tumor tissue specimens taken from 17 patients was compared.In addition,to determine the survivin expression in response to anti- cancer drugs in early stage HCC,the survivin expression was determined after the treatment of the HCC cells with anti-cancer drugs under hypoxic culture conditions. RESULTS:Survivin proteins were expressed in 64.7% of cells in early HCC specimens.A correlation between the survivin expression rate in the peritumoral hepatocytes and the rate of expression in the HCC specimens(low-rate group vs high-rate group)was observed.The survivin protein concentration in HCC cells was increased by the combination of hypoxia and anti-cancer drugs. CONCLUSION:This study suggests that survivin could be used as a therapeutic target in early HCC.     

Differential expression of genes during aflatoxin B(1)-induced hepatocarcinogenesis in tree shrews

AIM:Through exploring the regulation of gene expression during hepatocarcinogenesis induced by aflatoxin B1 (AFB1),to find out the responsible genes for hepatocellular carcinoma (HCC) and to further understand the underlying molecular mechanism.METHODS:Tree shrews ( Tupaia belangeri chinensis)were treated with or without AFB1 for about 90 weeks. Liver biopsies were performed regularly during the animal experiment. Eight shares of total RNA were respectively isolated from 2 HCC tissues, 2 HCC-surrounding noncancerous liver tissues, 2 biopsied tissues at the early stage(30^th week) of the experiment from the same animals as above, 1 mixed sample of three liver tissues biopsied at the beginning (0^th week) of the experiment, and another i mixed sample of two liver tissues from the untreated control animals biopsied at the 90^th week of the experiment. The samples were then tested with the method of Atlas^TM cDNA microarray assay. The levels of gene expression in these tissues taken at different time points during hepatocarcinogenesis were compared.RESULTS:The profiles of differently expressed genes were quite different in different ways of comparison.At the same period of hepatocarcinogenesis, the genes in the same function group usually had the same tendency for up-or down-regulation. Among the checked 588 genes that were known to be related to human cancer, 89 genes (15.1%) were recognized as “important genes” because they showed frequent changes in different ways of comparison. The differentially expressed genes during hepatocarcinogenesis could be classified into four categories: genes up-regulated in HCC tissue, genes with similar expressing levels in both HCC and HCC-surrounding liver tissues which were higher than that in the tissues prior to the development of HCC,genes down-regulated in HCC tissue, and genes up-regulated prior to the development of HCC but down-regulated after the development of HCC.CONCLUSION: A considerable number of genes could change their expressing levels both in HCC and in HCC-surrounding non-cancerous liver tissues. A few modular genes were up-regulated only in HCC but not in surrounding liver tissues, while some apoptosis-related genes were down-regulated in HCC and up-regulated in surrounding liver tissues. To compare gene-expressing levels among the liver tissues taken at different time points during hepatocarcinogenesis may be helpful to locate the responsible gene (s) and understand the mechanism for AFB1 induced liver cancer.     

Involvement of RhoA in progression of human hepatocellular carcinoma

BACKGROUND AND AIM: The activation of Rho proteins has been shown to lead to loss of polarity in cancer cells, as well as reorganization of the cytoskeleton and facilitation of cell motility, possibly resulting in their malignant potential. The clinicopathological significance of RhoA, however, is not yet well known in the case of hepatocellular carcinoma (HCC). This study evaluated the clinicopathological correlation of RhoA levels with HCC. METHODS: The intratumor expression level of Rho was determined and compared with that in adjacent non-cancerous hepatic tissue using quantitative real time RT-PCR and Western blotting in 64 patients with HCC. Relationships between the level of RhoA and clinicopathological factors were examined. RhoA protein expression was confirmed by immunohistochemistry. RESULTS: RhoA immunostaining was strong in malignant tissue whereas it was minimal in benign tissue. Tumor tissue of HCC patients demonstrated a copy number of RhoA mRNA that was well correlated with its protein level in each case and was significantly higher than that found in the corresponding non-cancerous liver tissue (P < 0.01). With regard to venous invasion, satellite lesions and advanced pTNM stage, the RhoA level tended to be higher in HCC than that seen in negative tissue (P < 0.05). CONCLUSIONS: This is the first demonstration that the expression level of RhoA is correlated with tumor progression and metastasis in HCC. RhoA in tumor tissue might be expected to be not only a good candidate marker for invasive and proliferative tumor cells, but also a molecular target of these cells.     

Survivin expression in early hepatocellular carcinoma and post-treatment with anti-cancer drug under hypoxic culture condition

AIM: To investigate the expression of survivin during the early stages of hepatocellular carcinoma (HCC). METHODS: Immunohistochemical expression of survivin in liver tumor and non-tumor tissue specimens taken from 17 patients was compared. In addition, to determine the survivin expression in response to anticancer drugs in early stage HCC, the survivin expression was determined after the treatment of the HCC cells with anti-cancer drugs under hypoxic culture conditions. RESULTS: Survivin proteins were expressed in 64.7％ of cells in early HCC specimens. A correlation between the survivin expression rate in the peritumoral hepatocytes and the rate of expression in the HCC specimens (low-rate group vs high-rate group) was observed. The survivin protein concentration in HCC cells was increased by the combination of hypoxia and anti-cancer drugs. CONCLUSION: This study suggests that survivin could be used as a therapeutic target in early HCC.     

PeroxiredoxinⅡ基因在肝癌组织中的表达及意义

目的观察peroxiredoxinⅡ（PrxⅡ）mRNA和蛋白在黄曲霉毒素B1（AFB1）诱发树鼩HCC形成过程中的表达变化,并在人肝癌癌旁组织和正常肝组织中进行验证,以探讨PrxⅡ在肝癌形成过程中的作用。方法应用RT-PCR和Western blot方法,检测6例AFB1诱发的树鼩肝癌、癌旁组织和这些动物肝癌发生前的活检肝组织,以及6例对照组动物相应时期的肝活检组织PrxⅡ在mRNA水平和蛋白水平的表达情况,并在18例人肝癌及其相应癌旁组织以及17名正常人肝组织进行验证。结果PrxⅡ在树鼩肝癌组织中的mRNA和蛋白质表达水平均明显高于相应的癌旁和癌前组织,也高于对照组同期活检肝组织（P〈0．05）;人肝癌组织中PrxⅡ的mRNA和蛋白表达改变和树鼩相符,即肝癌中的表达高于癌旁组织和正常肝组织（P〈0．05）。结论PrxⅡ基因可能与肝癌的发生发展有关,并有可能成为防治肝癌的分子靶标。     

Expression of microsomal prostaglandin E synthase-1 in human hepatocelluar carcinoma.

BACKGROUND/AIMS: The objective of this study was to evaluate the expression of microsomal prostaglandin E synthase-1 (mPGES-1) in hepatocellular carcinoma (HCC) tissues. METHODS: Forty surgically resected HCC tissues with adjacent non-tumorous liver tissues and 14 surgically resected, histologically normal liver tissues were used. The immunohistochemical expressions of the mPGES-1 protein in these HCC tissues and normal control livers were analysed. mPGES-1 mRNA expression was also analysed by the real-time polymerase chain reaction method using the same tissues. RESULTS: Microsomal prostaglandin E synthase-1 was not expressed in hepatocytes but instead in vascular endothelial cells and bile duct epithelial cells in normal liver tissues. The mPGES-1 expression in HCC tissues was significantly greater than its expression in the non-tumorous tissues. All types of HCC expressed more mPGES-1 than normal or hepatitis livers, and the levels of mPGES-1 expression in poorly differentiated HCC were similar to the levels in well-differentiated HCC. The mPGES-1 mRNA expression paralleled its protein expression in these tumorous and non-tumorous tissues. CONCLUSIONS: The present study is the first to demonstrate a high expression of mPGES-1 in well-differentiated HCC as well as in poorly differentiated HCC. These findings suggest that mPGES-1 may play a role in the advanced as well as early stage of hepatocarcinogenesis.     

Abnormal expression of HSP gp96 associated with HBV replication in human hepatocellular carcinoma

BACKGROUND: Heat shock protein (HSP) gp96 is a member of the HSP90 family and presumably overexpresses as a result of stimulation by mutated or abnormal proteins. Its abnormal expression correlates with carcinogenesis, progression and prognosis of hepatocellular carcinoma (HCC). In this study, we investigated the pathological characteristics of liver gp96 expression and its relationship with hepatitis B virus (HBV) replication in HCC patients. METHODS: Tumor specimens were prospectively collected from 30 HCC patients undergoing liver resection. Total RNAs were extracted from HCC or their noncancerous tissues. The distribution of gp96 expression in hepatocytes was investigated by streptavidin peroxidase (S-P) immunohistochemistry and tissue HBV-DNA was detected by the in situ molecular hybridization technique. The association of gp96 expression with HBV replication, and the histopathological characteristics of HCC were analyzed. RESULTS: The gp96 was strongly expressed in HCC (73.3%, 22 of 30) and weakly (46.7%, 14 of 30) in non-cancerous tissues. The gp96 expression in HCC tissues was correlated with degree of tumor differentiation and tumor size, but not with tumor number (P>0.05). Immunohistochemical analysis showed that 17 of 19 HCC patients with HBVDNA -positive were strongly expressed for gp96, whereas only 5 of 11 patients with HBV-DNA-negative were positive for gp96. A significant difference was found between the two groups (89.5% vs. 45.5%, P<0.05). CONCLUSIONS: The abnormal expressions of HSP gp96 in HCC tissues are associated with HBV replication. This finding indicates that HBV infection plays an important role in the development of HCC.