Cancer Res：血小板促肿瘤转移不依赖于NK细胞

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血小板的促转移的作用早已确认，血小板对和肿瘤转移的贡献包括屏蔽NK细胞对肿瘤细胞的杀伤作用，协助肿瘤细胞与内皮细胞之间的粘附，血小板P-选择素促进肿瘤细胞的出血管。

然而，血小板促转移功能的许多方面仍不清楚。在一项最新研究中，科研人员用转移性乳腺癌和黑色素瘤小鼠模型以探讨血小板的作用，研究主要侧重于肿瘤转移的器官特异性问题，重点考察肿瘤转移是否与NK细胞和血小板衍生与内皮细胞来源的P-选择素相关。

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在实验性和自发转移模型中，我们发现在NK细胞不存在的情况下，血小板会促进肿瘤的肺转移。此外，血小板的促肿瘤转移具有器官特异性，虽然明确提高肺转移，但并不影响B16F1的肝转移，事实上，肝转移发生在血小板缺失的情况下。此外，血小板的存在与否不影响NK细胞抗转移的活性，血小板的促转移的作用具有时间上的差异性。

最后，研究表明内皮细胞源性P-选择素与血小板衍生的P-选择素一样是重要的促进肺转移、肝转移的生物活性因子。该项研究结果有助于阐明血小板、NK细胞和P-选择素对肿瘤转移的作用，并提示P-选择素是一个有前景的防止肿瘤多器官转移的治疗靶标。
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<img src="http://www.bioon.com/biology/UploadFiles/201207/2012072816382096.gif" alt="" width="115" height="150" border="0" />

<a title="" href="http://dx.doi.org/10.1158/0008-5472.CAN-11-4010" target="_blank">doi:10.1158/0008-5472.CAN-11-4010</a>
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<br/><strong>Platelets and P-selectin control tumor cell metastasis in an organ-specific manner and independently of NK cells
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Lucy A. Coupland1, Beng H. Chong2, and Christopher R. Parish3,*

The pro-metastatic role of platelets has long been recognized with proposed mechanisms of action including shielding tumor cells from NK cell destruction and aiding endothelial attachment and extravasation of tumor cells with platelet P-selectin being implicated in these processes. However, many aspects of the pro-metastatic function of platelets remain unclear. In this study, we used mouse models of metastatic breast cancer and melanoma to investigate the platelet effect, focusing on organ specificity, the relationship with NK cells and the relative importance of platelet-derived versus endothelial-derived P-selectin. We found that platelets promote lung metastasis in the absence of NK cells in both acute and spontaneous metastasis models. Additionally, the pro-metastatic action of platelets was found to be organ specific, clearly enhancing lung metastasis but not affecting B16F1 liver metastasis, in fact, liver metastasis was enhanced in the absence of platelets. Furthermore, the profound anti-metastatic activity of NK cells was equally effective in the presence or absence of platelets and chronologically distinct from the pro-metastatic role of platelets. Lastly, it was shown that endothelial-derived P-selectin is just as important as platelet-derived P-selectin in promoting lung metastasis and also plays an important role in liver metastasis. Taken together, our findings help clarify the roles of platelets, NK cells and P-selectin in metastasis, and they identify P-selectin as an attractive therapeutic target for preventing metastasis in multiple organs.

<br/>来源：生物谷

<em>全球分子诊断网（</em><em>www.zhenduan.org</em><em>）</em><em></em>

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