Liotta L A, Stetler-Stevenson W G
Laboratory of Pathology, National Cancer Institute, NIH, Bethesda, Maryland 20892.
Cancer Res. 1991 Sep 15;51(18 Suppl):5054s-5059s.
A group of coordinated cellular processes, not just one gene product, is responsible for invasion and metastasis, the most life-threatening aspect of cancer. It is now recognized that negative factors may be just as important as positive elements. Genetic changes causing an imbalance of growth regulation lead to uncontrolled proliferation necessary for both primary tumor and metastasis expansion. However, unrestrained growth does not, by itself, cause invasion and metastasis. This phenotype may require additional genetic changes. Thus, tumorigenicity and metastatic potential have both overlapping and separate features. Invasion and metastasis can be facilitated by proteins which stimulate tumor cell attachment to host cellular or extracellular matrix determinants, tumor cell proteolysis of host barriers, such as the basement membrane, tumor cell locomotion, and tumor cell colony formation in the target organ for metastasis. Facilitory proteins may act at many levels both intracellularly or extracellularly but are counterbalanced by factors which can block their production, regulation, or action. A common theme has emerged. In addition to loss of growth control, an imbalanced regulation of motility and proteolysis appears to be required for invasion and metastasis.
一组协调的细胞过程，而非单一的基因产物，对侵袭和转移负责，这是癌症最危及生命的方面。现在人们认识到，负性因子可能与正性因子同样重要。导致生长调节失衡的基因变化会导致原发性肿瘤和转移灶扩展所必需的不受控制的增殖。然而，不受限制的生长本身并不会导致侵袭和转移。这种表型可能需要额外的基因变化。因此，致瘤性和转移潜能既有重叠特征也有各自独立的特征。侵袭和转移可由多种蛋白质促成，这些蛋白质刺激肿瘤细胞附着于宿主细胞或细胞外基质成分、肿瘤细胞对宿主屏障（如基底膜）的蛋白水解、肿瘤细胞运动以及肿瘤细胞在转移靶器官中形成集落。促进性蛋白质可在细胞内或细胞外的多个水平发挥作用，但会被能够阻断其产生、调节或作用的因子所抵消。一个共同的主题已经显现。除了生长控制丧失外，侵袭和转移似乎还需要运动性和蛋白水解的调节失衡。
