| Hepatocellular carcinoma (HCC) is one of the most familiar malignant tumors which is seriously harmful to health. The studies on hepatocarcinogenesis are mainly prossessed in two sides. Firstly, it has been showed by modern molecular biology research that there are close correlations between the tumorigenesis and the gene mutation. A lot of work has been done on the genetic mechanisms of tumorigenesis, but it is still not clear on the molecular mechanisms of HCC. In order to furtherly find the genes associated with HCC, our institute has constructed a compliment DNA (cDNA) library by suppression subtractive hybridization (SSH) and got 93 clones, then we investigated intensively on P02, which was among the 93 clones, and confirmed that P02 were overexpressed in HCC. We also discovered that P02 was homologous to translationally controlled tumor protein by homological analysis with the data in Genbank database.Secondly, people try to find out the cell origin of hepatocellular carcinoma. Recently, a new hepatocarcinogenesis was put forward that HCC was originated from stem cell or oval cell, which was undifferentiated in liver. Stem cells are a cluster of cells which exit for a long time and do not differentiate but maintain multiple differentiation potentials. Oval cells are confirmed to be the filial generation cell of stem cell. They express not only hepatocyte-type cytokeratin CK8 and CK18, but bile duct-type cytokeratin CK7 and CK19. Oval cells are considered by many scholars tobe the origin of hepatocellular carcinoma.In this expriment, an immunohistochemical Streptavidin-peroxidase (SP) method was used to examine the expression of CK18, CK19 in normal liver, cirrhosis, and HCC. The proliferation of oval cells was also examined to detect its role in hepatocarcinogenesis. A cryo-section in situ hybridization method was used to examine the expression of P02 gene in 15 pairs of HCC and cirrhosis tissues to investigate P02 morphologically and observe whether P02 was expressed in oval cells. The two sides of hepatocarcinogenesis studies were combined organically.Materials and methods: (1) 43 surgically resected HCC samples, 27 cirrhosis samples and 8 normal liver samples which were adjacent to hepatic cyst, liver hemangioma or cirrhosis . All the tissues were fixed in 10% neutral formalin and embedden in paraffin and used for SP. (2) 15 pairs of fresh HCC and cirrhosis samples were used for cryo-section in situ hybridization. (3) The data were analyzed by software SPSS 10.0, x 2-test was used for enumeration data and t-test was used for measurement data. A difference was considered significant if the P value was below 0.05.Results:(1) In normal liver tissue, positive staining for CK18 was seen mostly in bile duct epithelial cells, and inferior positive staining was seen in liver cells near portal area. Positive staining can be seen in other places occasionally. Positive staining located mainly on cell membrane, inferior positive staining was seen in liver cell plasm. The positive staining gradually decreaced from portal area to the central zero of hepatic lobufe, and the total positive rate was 25% in normal liver tissue. In cirrhosis of liver, cells in pseudolobule were mostly staining negative, but positive staining was seen in pseudo-bile duct. Strongly positive staining cells with oval nucleus can be seen in the brink of pseudolobule. The size of these cells was 1/2-1/4 of that of normal liver cells. The total positive rate was 29.63% in cirrhosis tissue .In HCC, strongly positive staining was seen in carcinoma cell and pseudo-bile. Scattered or clustered oval cells with strongly positive staining can be seen around the carcinomer. The total positive rate was 65.12% in HCC tissue. When cirrhosis groupcompared with normal liver group, there were no significant differences (P>0.05). But there were significant differences (P<0.01) between HCC group and cirrhosis group.In normal liver tissue, positive staining for CK19 was seen in bile duct epithelial cells. It was expressed nega...
|
PDF Full Text Request