关键词：乳腺癌；转移；共价键；半胱氨酸
摘 要：It has been suggested that PHSCN inhibits metastatic invasion by forming a covalent, disulfide bond with a cysteine residue on the beta1 ( 1) subunit of alpha5 beta1 ( 5 1) integrin1. However, these studies were performed with purified 51 integrin, which also produces evidence of covalent bond formation with the 5 subunit (tandem mass spectroscopy data not shown). Hence, the specificity of the reported interaction between PHSCN and the 1 subunit1 is suspect. Moreover, the cysteine rich 1 subunit can heterodimerize with 12 distinct alpha integrin subunits2, forming integrins that function in many pathways. In contrast, the 5 subunit interacts uniquely with the 1 subunit2 to induce invasion and support adhesion3-5; hence it is a much more desirable target.