Sugino Takashi, Yamaguchi Tomiko, Ogura Go, Saito Atsuko, Hashimoto Takeaki, Hoshi Nobuo, Yoshida Sayaka, Goodison Steve, Suzuki Toshimitsu
Department of Pathology, Fukushima Medical University School of Medicine, Fukushima, 960-1295, Japan.
BMC Med. 2004 Apr 5;2:9. doi: 10.1186/1741-7015-2-9.
We have previously described an alternative invasion-independent pathway of cancer metastasis in a murine mammary tumor model. This pathway is initiated by intravasation of tumor nests enveloped by endothelial cells of sinusoidal vasculature within the tumor. In this study, we examined whether evidence for the invasion-independent pathway of metastasis is present in human cancers.
Archival specimens of 10 common types of human cancers were examined for the presence of sinusoidal vasculature enveloping tumor nests and subsequently generated endothelial-covered tumor emboli in efferent veins.
A percentage of tumor emboli in all cancers was found to be enveloped by endothelial cells, but these structures were particularly prevalent in renal cell carcinomas, hepatocellular carcinomas and follicular thyroid carcinomas. A common feature of the vasculature in these tumors was the presence of dilated sinusoid-like structures surrounding tumor nests. A high mean vascular area within tumors, an indication of sinusoidal vascular development, was significantly related to the presence of endothelial-covered tumor emboli.
These results suggest that an invasion-independent metastatic pathway is possible in a wide variety of human cancers. Further investigation of this phenomenon may present new therapeutic strategies for the amelioration of cancer metastasis.
我们之前在一个小鼠乳腺肿瘤模型中描述了一种癌症转移的替代途径，该途径不依赖于侵袭。此途径由肿瘤内被窦状脉管系统的内皮细胞包裹的肿瘤巢进入血管引发。在本研究中，我们检测了人类癌症中是否存在不依赖侵袭的转移途径的证据。
检查了10种常见类型人类癌症的存档标本，以确定是否存在包裹肿瘤巢的窦状脉管系统，以及随后在输出静脉中生成内皮细胞覆盖的肿瘤栓子。
发现所有癌症中的一定比例的肿瘤栓子被内皮细胞包裹，但这些结构在肾细胞癌、肝细胞癌和滤泡性甲状腺癌中尤为普遍。这些肿瘤脉管系统的一个共同特征是肿瘤巢周围存在扩张的窦状样结构。肿瘤内较高的平均血管面积，这是窦状血管发育的一个指标，与内皮细胞覆盖的肿瘤栓子的存在显著相关。
这些结果表明，在多种人类癌症中，不依赖侵袭的转移途径是可能的。对这一现象的进一步研究可能会为改善癌症转移提供新的治疗策略。
