Miller F R, Heppner G H
E. Walter Albachten Department of Immunology, Michigan Cancer Foundation, Detroit.
Cancer Metastasis Rev. 1990 Jul;9(1):21-34. doi: 10.1007/BF00047586.
The metastatic cascade is a sequence of events that must be completed for metastases to be established. The realization that tumors are heterogeneous, consisting of many different subpopulations differing in many characteristics, and the belief that there are selective events in the metastatic process have led several laboratories to isolate and characterize variants with both high and low metastatic potential. Typically, the highly metastatic variants have been able to form distant metastases when implanted into the subcutis. Such lines have been popular for studies of metastatic mechanisms and anti-metastatic therapy, but they may be atypical examples, and thus not the best experimental models. Recent studies indicate that normal tissue influences metastasis such that many tumors metastasize only if placed in the orthotopic site. Furthermore, some cells that do not metastasize individually are able to do so in conjunction with other variant subpopulations. Thus, mixtures of tumor cells in the tissue of origin can express a more malignant character. We review possible mechanisms for such influential interactions, as well as the role of cellular interactions in generating heterogeneity and stabilizing tumor characteristics.
转移级联反应是一系列为建立转移灶而必须完成的事件。认识到肿瘤具有异质性，由许多在许多特征上不同的亚群组成，并且相信转移过程中存在选择性事件，导致几个实验室分离和鉴定具有高转移潜能和低转移潜能的变体。通常，高转移变体植入皮下时能够形成远处转移灶。这类细胞系在转移机制和抗转移治疗研究中很受欢迎，但它们可能是不典型的例子，因此不是最佳的实验模型。最近的研究表明，正常组织会影响转移，以至于许多肿瘤只有放置在原位才会发生转移。此外，一些单独不会转移的细胞与其他变体亚群一起时能够发生转移。因此，原发组织中的肿瘤细胞混合物可以表现出更恶性的特征。我们综述了这种影响性相互作用的可能机制，以及细胞间相互作用在产生异质性和稳定肿瘤特征方面的作用。
