[Matrix metalloproteinases map of lymphogenous metastasis of hepatocarcinoma cell in mice].

Background & Objective: Metastasis is the leading cause of tumor-related death, in which lymphogenous metastasis is the most common pattern and also a bridgehead of further metastasis. However, the molecular mechanism of metastasis is uncertain. This study was designed to investigate the correlation between the metastasis of hepatocarcinoma cell(HCC) to lymphnode and matrix metalloproteinases (MMPs) activity and the expression of Fas ligand of tumor cells in lymphnodes.

Methods: The maps of MMPs in supernatants of mouse HCCs with different metastatic potential Hca-F(high potential) and Hca-P cells(low potential) cultured with extract of lymph node, liver or spleen were examined by zymographic analysis. Growth fraction of lymphocytes in lymph nodes of tumor burden mice was detected by flow cytometry. The apoptosis signals of macrophages in lymph nodes were observed with TUNEL staining. The expressions of Fas ligand of Hca-F and Hca-P cells in the mice were examined by immunohistochemistry.

Results: With the presence of the extraction of lymph note, the quantity of MMP-9 significantly increased (P < 0.01): in RPMI1640 medium, the quantity of MMP-9 produced by Hca-F and Hca-P were 1256 +/- 157 and 2642 +/- 385, respectively. After the addition of extraction of lymph node, the quantity of MMP-9 increased to 12,403 +/- 894 and 9086 +/- 686, respectively, together with the secretion of a large amount of MMP-2 (Hca-F: 7364 +/- 2001, Hca-P: 2997 +/- 1990) and active MMP-9 (Hca-F: 7297 +/- 1657, Hca-P: 3914 +/- 1253), and the amount of which was also more in Hca-F than in Hca-P cells(P < 0.05). There was no MMPs detected when the extraction of liver and spleen is present. The growth fraction of lymphocytes was as follow: in the Hca-F cells, the proliferating peak of lymphocytes appeared on the 14th day post-inoculation and then decreased rapidly, while in the Hca-P cells, the peak appeared on the 7th day post-inoculation and then kept at a high level. TUNEL staining showed that the positive signals of macrophages were detected around Hca-F cells. The expression of Fas ligand of Hca-F cells was stronger than that of Hca-P cells (P < 0.01).

Conclusion: The MMPs secretion of Hca-F and Hca-P cell depend on the environment of lymph nodes. The increased expression of Fas ligand protein in Hca-F tumor cells with high lymphogenous metastatic potential in lymph nodes may help tumor cells escape from being killed by host lymphocytes.