| Objective: HCC is the fifth most common cancer in the world and comprises more than 90% of human liver cancers. Hepatic resection and liver transplantation are the two main treatment modalities for HCC, and the 5 year survival rate correlates with tumor staging at the time of diagnosis. The majority of HCC patients present with an advanced stage of cancer for which chemotherapy and radiotherapy have limited efficacy. Hence, understanding the mechanism underlying hepatocarcinogenes is essential for the management of liver malignancy. The stochastic model indicates that a few cells which acquired proliferative potential via stochastic events are responsible for tumor formation. This minor population of cells, termed cancer stem cells (CSC) or tumor initiating cells (TIC), possesses stem cell-like properties and contributes to a hierarchical structure containing varied progenies in a similar fashion to normal stem cells. Dysregulated self-renewal capability, following oncogenic mutations, is one of the key events in the early stages of carcinogenesis. It is believed that CSC usually arise from normal stem/progenitor cells with enhanced or acquired self-renewal capability. However, it remains unclear whether this hypothesis can be applied to hepatocarcinogenesis. Many attempts have been made to detect a small subset of cancer cells with the characteristics of CSC in HCC.CSC shave been characterized in HCC using a variety of stem cell markers, including CD133 and CD90. The aim of this study is to evaluate the expression of CD133 and CD90 in liver cancer tissue, para-tumor tissue and normal liver tissue, and to analyze the relationship between the expressions and the clinicopathological characteristics.Methods: 54 tumor tissues, 37 tumor-surround- ing tissues were obtained from patiens with liver cancer undergoing surgery, and 14 nomal liver tissue samples were obtained from patiens undergoing surgery. Immunohistochemistry is used to detect expression of CD133 and CD90. X2 and Log-rank were used to determine the relationship between the expression and clinicopathological parameters of liver cancer.Results:1 Expression of CD133 and CD90 protein in HCC, para-tumor and normal liver tissue: CD133-positive stain rate was 72.22%(39/54)in HCC tissue, 48.65%(18/37)in para-tumor tissue and 0%(0/14)in normal liver tissue; CD90-positive stain rate was 74.07% (40/54) in HCC tissue, 51.35% (19/37) in para-tumor tissue and 0%(0/14)in normal liver tissue. X2 analysis indicuted that CD133-positive stain rate and CD90-positive stain rate in HCC tissue were significant higher than that in para-tumor tissue (P<0.05) and normal liver tissue respectively (P<0.05) .2 In the HCC tissues, I, II stage group CD133 protein expression rate was 57.14% (12/21), III, IV stage group CD133 protein expression rate was 81.82% (27/33), the expression of CD133 in III, IV stage group was significantly higher than in I, II stage group (P <0.05). In the HCC tissues, well-differentiated carcinoma group (I, II Class) CD133 protein expression rate was 60.00% (18/30), poorly differentiated carcinoma group (III, IV Class) CD133 protein expression rate was 87.5% (21 / 24), the expression of CD133 in poorly differentiated carcinoma group (III, IV Class) was significantly higher than in well-differentiated carcinoma group (I, II Class) (P <0.05). In the HCC tissue, bile duct or portal vein tumor thrombus group of CD133 protein expression rate was 100.0% (13/13), no bile duct or portal vein tumor thrombus group of CD133 positive expression rate was 63.41% (26/41), the expression of CD133 in a bile duct or portal vein tumor thrombus group was significantly higher than no bile duct or portal vein tumor thrombus group (P <0.05). In the HCC tissue, capsule group CD133 protein expression rate was 46.67% (7 / 15), no capsule group of CD133 protein expression rate was 82.05% (32/39), the expression of CD133 in the absence of capsule group of significantly higher than that capsule group (P <0.05). CD133 protein expression is not related with patient age, sex, tumor sizes and AFP (P> 0.05). 3 In the HCC tissues, I, II stage group CD90 protein expression rate was 57.14% (12/21), III, IV stage group CD90 protein expression rate was 84.85% (28/33), the expression of CD90 in III, IV stage group was significantly higher than in I, II stage group (P <0.05). In the HCC tissues, well-differentiated carcinoma group (I, II Class) CD90 protein expression rate was 63.33% (19/30), poorly differentiated carcinoma group (III, IV Class) CD90 protein expression rate was 87.5% (21 / 24), the expression of CD90 in poorly differentiated carcinoma group (III, IV Class) was significantly higher than in well-differentiated carcinoma group (I, II Class) (P <0.05). In the HCC tissue, bile duct or portal vein tumor thrombus group of CD90 protein expression rate was 100.0% (13/13), no bile duct or portal vein tumor thrombus group of CD90 positive expression rate was 65.85% (27/41), the expression of CD90 in a bile duct or portal vein tumor thrombus group was significantly higher than no bile duct or portal vein tumor thrombus group (P <0.05). In the HCC tissue, capsule group CD90 protein expression rate was 40.00% (6/15), no capsule group of CD90 protein expression rate was 87.18% (34/39), the expression of CD90 in the absence of capsule group of significantly higher than that capsule group (P <0.05). CD90 protein expression is not related with patient age, sex, tumor size and AFP (P> 0.05).4 One-year and 2-year survival rate of 54 patients were 68.52% and 50.00% respectively; One year and 2-year survival rate in patients with CD133-positive were 64.10% and 46.15% respectively, The median survival time was 18 months and in patients with CD133-negative stain were 80.00% and 60.00% respectively, The median survival time was 23 months;the median survival of CD133-negative expression group was significantly higher than CD133-positive expression group (P<0.05); One-year and 2-year survival rate in patients with CD90-positive stain were 65.00% and 47.50% respectively, The median survival time was 17 months; And in patients with CD90-negative stain were 78.57% and 57.14% respectively, The median survival time was 24 months; the median survival of CD90-negative expression group was significantly higher than CD90-positive expression group (P<0.05).Conclusion: 1 Expression of CD133 and CD90 in HCC tissue were significantly higher than in para-tumor tissue and normal liver tissue, expression in cancer tissue was the highest. It was suggested that CD133 and CD90 assocated with liver cancer occurrence and development.2 Expression of CD133 in HCC tissue was significantly associated with clinical stage, tumor differentiation, with and without bile duct or portal vein tumor embolus, with or without capsual (P<0.05); But they were not associated with age, gender, tumor sizes and AFP level(P>0.05). It was suggested that CD133 and the biological characteristics of hepatocellular carcinoma (recurrence and metastasis) are closely related.3 Expression of CD90 in HCC tissue was significantly associated with clinical stage, tumor differentiation, with and without bile duct or portal vein tumor embolus, with or without capsual (P<0.05); But they were not associated with age, gender, tumor sizes and AFP level(P>0.05). It was suggested that CD90 and the biological characteristics of hepatocellular carcinoma (recurrence and metastasis) are closely related.4 The accumulate survival rate of patients with CD133-positive stain and CD90-positive stain was significantly lower than that with CD133-negative stain and CD90- negative stain. It was suggested that CD133 expression or CD90 expression related to prognosis of the HCC patients.5 Expression of CD133 and CD90 positive cells have the characteristics of cancer stem cells, indirect proof of CD133 and CD90 may be a marker of liver cancer stem cells. |
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