Effect Of HBV On Expressions Of MMP-2 And NM23 In HCC

AIM: Hepatocellular carcinoma(HCC)is one of the most common malignant tumor in the world. About 80% HCC patients are correlated to hepatitis B virus(HBV)infection. Hepatits B virus X protein(HBx) is the only protein expressed in hepatic cell malignant transformation. It is closely correlated to the occurrence and development of HCC. MMP-2 has been identified as key enzymes that trigger localized proteolysis and generate a path in the ECM for HCC migration. The NM23 gene was first identified as a potential metastasis inhibitor. NM23 is regionalized as the most convincing metastasis suppressor gene at present. Negative correlation between the expression of NM23 and the metastasis potential has been documented in many human tumors. To investigate the expression of MMP-2 and NM23 between HBsAg positive and HBsAg negative hepatocellular carcinoma could give us a better understanding of the function of HBx and their progressive changes during HBx-mediated hepatocarcinogenesis,unveiling potential new targets in tumor therapy against this aggressive malignancy.METHODS: 1. Samples collecting and analyzing: 56 HCC surgical specimens have been collected by pathology diagnoses, including 48 male specimens and 8 female specimens. The HCC samples were classified according to the Edmondson classification standard and included 1 GradeⅠ, 18 GradeⅡ, 36 GradeⅢand 4 GradeⅣ. The 58 tissue samples have been divided in two sets: high - risk group containing 38 tissue samples, low-risk group containing 18 tissue samples, high risk was defined by the presence of any of the following: vessel violation, multiple metastases in liver, lymph node metastasis and distant metastasis.2.Using MaxVision TM quick immunohistochemistry by two step ways to dectect the expression of MMP-2, NM23 HBsAg in the pathological section. Then, chooseχ2 analysis and spearman rank correlation as statistic way. To probe the relation of MMP-2, NM23 expression in HCC and the HBV infected.3. The cell line HepG2 negtive HBV expression, and the cell line HepG2.215 from HepG2 which stable transfected HBV gene and constantly expression were cultured. The expression of protein of MMP-2, NM23 in both two cell line were dectected by Western Blot and immuno- cytochemistry.RESULTS: 1. The result of immunohistochemistry illustrated that the positive expression rate of MMP-2 and NM23 was 62.50% (35/56), 32.15%(18/56)respectively in 56 cases tissue of HCC. The positive expression of MMP-2 and NM23 had highly relation with the differentiation degree and metastasis potential; the positive rate of NM23 in HBsAg positive group was lower than HBsAg negative group. While the positive rate of MMP-2 in HBsAg positive group was higher than HBsAg negative group, and there are significantly difference between two groups ( P <0.05).There were 26 cases MMP-2 positive expression in 36 cases HBsAg positive tissue of HCC, and 11 cases MMP-2 negative expression in 20 cases HBsAg negative tissue of HCC. According to the statistical analysis, the result had correlation(r = 0.269, P < 0.05). There were 8 cases NM23 positive expression in 36 cases HBsAg positive tissue of HCC, while 10 cases NM23 negative expression in 20 cases HBsAg negative tissue of HCC. The statistical analysis suggested correlation(r = -0.285, P < 0.05).2. The results of detection of MMP-2, NM23 by Western Blot illustrate that both MMP-2 and NM23 are all expression in HepG2 cell line and HepG2.215 cell line ; the protein of MMP-2 expressed in HepG2.215 cell line were evidently lower than that in HepG2 cell line (P < 0.05). Howere, the protein of NM23 expressed in HepG2.215 cell line were evidently lower than that in HepG2 cell line (P < 0.05), while there were no evidently difference in the expression ofβ-actin.3. The result of immunocytochemistry illustrated that the expression level of MMP-2 were highly increased by compare HepG2.215 cell line with HepG2 cell line, but the level of NM23 expression were evidently decreased (P <0.01), as the same with the result of Western Blot. CONCLUSION: The expression of MMP-2 and NM23 in HCC could reflect the different Edmondson degree and metastasis potential of HCC. There was a significant difference in the MMP-2 and NM23 expression between infection of HBV and not infection of HBV hepatocellular carcinoma, which indicated a possibility that long time HBV infection could induce the expression profile of metastasis inhibitors, furthermore, cause the invasion and metastasis of hepatocellular carcinoma. Comparing with the HepG2 cells, the expression of MMP-2 in the HepG2.215 cells was obviously higher, and the expression of NM23 is opposite. That coincided with our previous experiments of immunocytochemistry. It was further confirmed the expression of MMP-2 and NM23 protein were correlated with HBV infection. These results could give us a better understanding of the metastasis function of HBV in HCC.