Possible role of immune surveillance at the initial phase of metastasis produced by B16BL6 melanoma cells

FEBS Letters

Imafuku, Hidetoshi²  Kikkawa, Hironori²  Oku, Naoto²  Tsukada, Hideo¹ 

[1] Central Research Laboratory, Hamamatsu Photonics, Hirakuchi, Hamakita, Shizuoka 434-0041, Japan;Department of Radiobiochemistry, School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Shizuoka 422-8526, Japan

关键词: Metastasis;    Immune surveillance;    Macrophage;    B16BL6;    Positron emission tomography;    Tumor cell trafficking;    PET;    positron emission tomography;    [2-18F]FDG;    [2-18F]2-fluoro-2-deoxy-D-glucose;    ROI;    region of interest;    2-ClAd;    2-chloroadenosine;   

DOI  :  10.1016/S0014-5793(00)01144-3

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The relationship among the real-time trafficking of lung metastatic B16BL6 cells, metastatic potential, and the injected number of the cells was examined, since the smaller the number of tumor cells injected, the more clearly the immune defense may be observed. When 1×10⁶ or 1×10⁵ B16BL6 cells were injected into mice via the tail vein, both numbers of cells accumulated in the lung at a similar rate: there was an approximately 10-fold difference in the number of accumulated cells between the two doses. Elimination from the lung was not dependent on the cell number but on the proportion of accumulated cells. However, the injection of 1×10⁴ cells resulted in lung accumulation less than one-tenth of that obtained with 1×10⁵ cell injection. Metastasis was observed when 1×10⁵ or 1×10⁶ B16BL6 cells were injected, but not after injection of 1×10⁴ cells. To clarify the roles of the immune defense system at the initial phase of metastasis, we challenged macrophage-depleted mice with 1×10⁴ tumor cells. Treatment of mice with 2-chloroadenosine prior to the tumor cell challenge cancelled the suppression of not only metastasis but also the lung accumulation. Furthermore, the administration of 2-chloroadenosine following the tumor cell challenge had little effect on the metastatic potential. These results suggest that the immune surveillance whose action was obvious at the low dose of challenged tumor cells functions strongly at the initial phase but not at the advanced stages of the metastatic process, and that macrophages play an important role in the suppression of metastasis.

【 授权许可】

Unknown