OBJECTIVETo establish a single cell-derived organ site-specific metastatic model of human hepatocellular carcinoma (HCC) in the nude mouse.

METHODSUsing the limited dilution method, HCCLM3-R-LM1 and HCCLM3-R-LnM1 cell lines were used to generate eight (LM1-S2, -S3, -S4, -S5, -S11, -S15, -S21, and -S23) and five (LnM1-S7, -S11, -S13, -S17, and -S20) single cell-derived monoclonal cell lines, respectively. The monoclonal cell lines were seeded into 4-week-old nude mice, and three weeks later the resultant subcutaneous tumor tissues were orthotopically transplanted into the livers of nude mice. At six weeks after implantation, lung and lymph node were extracted for analysis of the metastatic foci fluorescence area and pathology to assess the number of metastatic foci.

RESULTSAmong the 13 mice implanted with the established monoclonal cell lines, six grew subcutaneous tumors. When orthotopically transplanted, the six tumors showed remarkably different metastatic potential and organ site-specific tropism. The fluorescence areas of lung metastatic foci were: LM1-S3, 80 923+/-10 162; LM1-S4, 1506 000+/-297 064; LM1-S5, 36 140+/-8 210; and LM1-S11, 508 448+/-134 272 (P less than 0.01); no lymph node metastases were found for these lines. For LnM1-S11, the fluorescence areas of lung and lymph node metastatic foci were 435 062+/-206 620 and 1 254 000+/-225 171, respectively.

CONCLUSIONWe successfully established several monoclonal cell lines and nude mouse models of HCC with different metastatic potential and organ tropism. Among them, LM1-S3, LM1-S4, LM1-S5, and LM1-S11 have metastasis organotropism to lung. The LnM1-S11 line exhibits dual metastasis organotropism to lung and lymph node. These monoclonal cell lines and nude mouse models may represent useful tools for study of HCC metastasis organotropism.