Contributions of lung tissue extracts to invasion and migration of @entity1 XXXX cells with various metastatic potentials.

@entity1 @entity1476 @entity19 @entity1495 @entity3 @entity157
PURPOSE: The MHCC97 cell line contains two clones with high (MHCC97-H) and low (MHCC97-L) metastatic potentials, for which the pulmonary metastatic rate was 100% vs 40% between the two @entity1 @entity157 ( @entity157 ) clones. In an effort to elucidate the mechanism of organ-specific @entity3 , we studied the effect of lung extracts from C57BL/6 @entity19 on migration and invasion using the MHCC97 cell line. METHODS: Determination of migration and invasion induced by lung extracts to MHCC97 cell lines was examined by chemoinvasion assay. The organization of cytoskeleton was tested using filamentous actin (F-actin) polymerization assay and flow cytometry. The activity of matrix metalloproteinase (MMPs) was analyzed by zymogram. Fluorescence double staining was employed for MMPs and F-actin colocalization in MHCC97-H cells induced by lung extracts. RESULTS: The number of cells in response to extracts of lung, liver, kidney, and spleen in MHCC97-H cells was 64+/-10, 6+/-2, 22+/-4, and 3+/-1, respectively. Of the extracts, lung extracts showed significant differences to promote the migratory and invasive ability for MHCC97-H cells( p<0.001). The number of cells in response to lung extracts was threefold higher in MHCC97-H than that of cells in MHCC97-L ( p<0.001). Confocal laser scan microscope of MHCC97-H cells and MHCC97-L cells stimulated with lung extracts revealed pseudopodia formation around the cell front at the indicated time point. With the time increasing, the pseudopodia formation became increasingly more obvious and distinct. Compared with unstimulated cells, analysis of FACS showed a transient 1.9-fold and 1.7-fold increase in F-actin within 30 s in MHCC97-H cells and MHCC97-L cells, respectively. Confocal laser scan microscopy of MHCC97-H cells stimulated in suspension with lung extracts revealed intense F-actin staining in the periphery of the cells and redistribution of F-actin towards a leading edge. After the cells were incubated with lung extracts, not only expressions of active and latent form of @entity1495 were upregulated, but that of latent form of @entity1476 was increased in the MHCC97-H cells and MHCC97-L cells. The levels of latent and active form of @entity1495 (18.8+/-1.2, 100.1+/-1.1), and latent form of @entity1476 (22.4+/-1.3) were much higher in MHCC97-H cells than those of MHCC97-L cells, which were 7.8+/-0.3, 40.8+/-2.2, and 8.2+/-0.4, respectively. @entity1495 was mainly localized perinuclear pool when the MHCC97-H cells were incubated with serum-free medium. After the cells were stimulated with lung extracts, @entity1495 were expressed and colocalized with F-actin at the front of extending pseudopodia. CONCLUSIONS: Our results indicate that the expression of matrix metalloproteinase and the pseudopodia formation in MHCC97-H cells may correlate to the metastatic potential; thus, the host environment may contribute to the preferential @entity3 of @entity157 cells to the lung depending on the high level of @entity1495 and migratory ability.
