Immune Surveillance System on Metastasis Cell Trafficking

Influence of the Immune Surveillance System on Metastasis Cell Trafficking 

Host resistance factors may also be important in metastatic cell trafficking. For instance, immune surveillance may reduce the number of metastatic cells in the bloodstream, resulting in a reduced accumulation of cells in a target organ. Likewise, even after surgical removal of the primary tumor, a substantial number of viable tumor cells can be detected in the circulation. However, this 

The injection of 1 x 10 cells resulted in lung accumulation less than one-tenth of that obtained with 1 x 10 cell-injection. Metastasis was observed when 1 X 10 or 1 x 10 B16BL6 cells were injected (colony number on the surface of each mouse lungs was 174, 173, 170, 165, and 148 for 1 x 10 cells injected, and 300 in all five mice tested for 1 x 10 cells injected). Metastasis was not observed after injection of 1 x 10 cells (no colony was observed in five mice tested). 

Similar results were obtained with fiver metastatic RAW117-H10 cells (31) when 1 x 10 or 1 x 10 RAW117-H10 cells were injected into mice via a portal vein, both numbers of cells caused fiver metastasis and cells accumulated 

These data allow us to conclude that immune surveillance is a strong factor preventing metastasis during the first phase of the metastatic process, but not at later stages. Further, macrophages appear to play an important role in this immune surveillance, as revealed obvious when a small number of tumor cells 

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