Molecular mechanism about lymphogenous metastasis of hepatocarcinoma cells in mice

AIM: To investigate the correlation between lymphogenous metastasis and matrix metalloproteinases (MMPs) activity and the expression of Fas ligand of tumor cells in lymph nodes. METHODS: Fifty-six inbred 615-mice were equally divided into 2 groups and inoculated with Hca-F and Hca-P cells. Their lymph node metastatic rates were examined. Growth fraction of lymphocytes in host lymph nodes was detected by flow cytometry. The Hca-F and Hca-P cells were cultured with extract of lymph node, liver or spleen. The quantity of MMPs in these supernatants was examined by zymographic analysis. The expression of Fas ligand, PCNA, Bcl-2 protein of Hca-F and Hca-P cells in the mice were examined by immunohistochemistry. The apoptosis signals of macro-phages in lymph nodes were observed with in situ DNA fragmentation. RESULTS: On the 28th day post-inoculation, the lymph node metastatic rate of HcaF was 80%(16/20), whereas that of Hca-P was 25%(5/20). The growth fraction of lymphocytes was as follows: in the Hca-F cells, the proliferating peak of lymphocytes appeared on the 14th day post inoculation and then decreased rapidly, while in HcaP cells, the peak appeared on the 7th day post inoculation and then kept at a high level. With the extract of lymph node, the quantity of the MMP-9 activity increased (P【0.01) and active MMP-9 and MMP-2 were produced by both Hca-F and Hca-P tumor cells, which did not produce MMPs without the extract of lymph node or with the extracts of the liver and spleen. The expression of Fas Ligand of Hca-F cells was stronger than that of Hca-P cells (P 【0.01). The expressions of PCNA and Bcl-2 protein of Hca-F cells in the tumors of inoculated area were the same as that of Hca-P cells. In situ DNA fragmentation showed that the positive signals of macrophages were around Hca-F cells. CONCLUSION: Secretion of MMPs which was associated with metastatic ability of Hca-F and Hca-P tumor cells depends on the environment of lymph nodes. The increased expression of Fas ligand protein of Hca-F tumor cells with high lymphogenous metastatic potential in lymph nodes may help tumor cells escape from being killed by host lymphocytes.

Alterations in metastatic properties of hepatocellular carcinoma cell following H-ras oncogene transfection

AIM: To demonstrate the relationship between H-ras oncogene and hepatocellular carcinoma (HCC) metastasis. METHODS: Activated H-ras oncogene was transfected into SMMC 7721, a cell line derived from human HCC, by calcium phosphate transfection method. Some metastasis-related parameters were detected in vitro, including adhesion assay, migration assay, expression of collagenase IV(c IV ase) and epidermal growth factor receptor (EGFR). RESULTS: The abilities of H-ras-transfected cell clones in adhesion to laminin (LN) or fibronectin (FN), migration, c IV ase secretion increased markedly, and the expression of EGFR elevated moderately. More importantly, these alterations were consistent positively with the expression of p21, the protein product of H-ras oncogene. CONCLUSION: H-ras oncogene could induce the metastatic phenotype of HCC cell in vitro to raise its metastatic potential.

MMP-2和MMP-9在声带息肉发病机制中的作用

有研究表明,声带息肉基底膜（basilar membrane,BM）存在质的改变,并认为这种改变可能是声带息肉形成的重要原因。MMP-2和MMP-9是胶原降解的关键酶,其特异性底物是Ⅳ型胶原纤维，而Ⅳ型胶原纤维是基底膜主要骨架，所以胶原酶在启动基底膜降解中起主导作用。本文拟通过分析基质金属蛋白酶2（matrix metalloproteinase-2，MMP-2）和MMP-9在声带息肉中的表达，同时观察影响其表达及活性调控的转化生长因子β1（transforming growth factor beta 1，TGF-β1），探讨其在声带息肉形成中的作用。

Dynamic changes in the collagen metabolism of liver fibrosis at the transcription level in rabbits with Schistosomiasis japonica

OBJECTIVE: To study the role of the synthesis and degradation of collagen at the transcription level during liver fibrogenesis due to schistosomiasis japonica in rabbits. METHODS: New Zealand rabbits challenged by cercariae of Schistosoma japonicum (S. japonicum) were served as animal models for liver fibrosis. Liver specimens were collected through operations at 4, 6, 8, 10, 12, 16, 20, 24 and 28 wks after challenge. Type I collagen, type III collagen, type IV collagen, MMP-1 and MMP-9 mRNA levels of liver tissue were detected by RT-PCR + Dot blot. The size of egg granulomas and the degree of liver fibrosis were measured by histopathological examinations. RESULTS: Type I collagen, type III collagen, type IV collagen, MMP-1 and MMP-9 mRNA levels increased simultaneously in the early stage after challenge. Most of them reached their peak at 10 weeks, and compared with normal controls, type I collagen, type III collagen, type IV collagen, MMP-1 and MMP-9 mRNA levels increased by 12.0-, 11.0-, 6.6-, 10.0- and 11.0-fold, respectively, coinciding with the change of egg granulomas, i.e., the change in the inflammatory process. Then both collagen and collagenase mRNA levels decreased. Type I, III and IV collagen mRNA levels declined to 2-fold to 3-fold as compared with normal controls (P 0.05) at 28 wks. This study shows that the synthesis and degradation of collagen keep a dynamic balance at the early stage of schistosomiasis japonica challenge, while at the later stages the quantity of collagen synthesis was higher than that of collagen degradation. CONCLUSIONS: It was confirmed at transcription level that when the quantity of collagen synthesis was higher than that of collagen degradation liver fibrogenesis may be resulted in.

基质金属蛋白酶-9与上下气道炎症反应一致性

基质金属蛋白酶-9（matrix matmetalloproteinase-9，MMP-9）能有效降解明胶和基底膜的主要成分，在上下气道炎症性疾病发病机制中发挥着重要作用。目前研究表明其作用机制与促进炎性细胞浸润、气道重塑以及气道高反应性等病变过程有关。本文综述了MMP-9与上下气道炎症反应一致性的研究进展。