Monsky W L, Chen W T
Department of Anatomy and Cell Biology, Georgetown University School of Medicine, Washington DC 20007.
Semin Cancer Biol. 1993 Aug;4(4):251-8.
Neoplastic cells elaborate a vast array of proteases that enable them to proteolytically digest underlying adhesion molecules. In doing this, the tumor cell disrupts the adhesive interactions holding it in place so it is free to degrade and migrate through the basement membrane and interstitial stroma resulting in invasion and ultimately metastasis. Invasive cells elaborate specialized membrane protrusions, invadopodia, that actively degrade the underlying substratum. Evidence indicates that integral membrane proteases and receptors for secreted proteases are present on these surface protrusions. All the major classes of secreted proteases are reported to associate with the plasma membrane. Interactions between proteases occurring at the plasma membrane may result in proenzyme activation. It is possible that various proteases in close proximity to each other on the plasma membrane could interact in a proteolytic cascade resulting in in vivo activation, and the subsequent degradation of adhesion proteins.
肿瘤细胞分泌大量蛋白酶，使其能够通过蛋白水解作用消化潜在的黏附分子。在此过程中，肿瘤细胞破坏了将其固定在原位的黏附相互作用，从而能够自由降解并穿过基底膜和间质基质，导致侵袭并最终发生转移。侵袭性细胞会形成特殊的膜突出结构——侵袭伪足，其可主动降解下方的基质。有证据表明，这些表面突出结构上存在整合膜蛋白酶和分泌型蛋白酶的受体。据报道，所有主要类型的分泌型蛋白酶都与质膜相关。质膜上发生的蛋白酶之间的相互作用可能导致酶原激活。质膜上彼此靠近的各种蛋白酶有可能以蛋白水解级联的方式相互作用，从而在体内激活，并随后降解黏附蛋白。
