A cysteine proteinase, which cleaves human C3, the third component of complement, is involved in tumorigenicity and metastasis of human melanoma
Jean, D.; Bar-Eli, M.; Huang, S.; Xie, K.; Rodrigues-Lima, F.; Hermann, J.; Frade, R.
Cancer Research 56(2): 254-258
1996
ISSN/ISBN: 0008-5472 PMID: 8542576 Document Number: 469415
The DM-4 human melanoma cell line, which is highly metastatic in nude mice, expresses a C3-cleaving activity that proteolyzes labeled as well as unlabeled human C3. This C3-cleaving activity is a cysteine proteinase characterized by a M-r 41,000. The p41 proteinase shares antigenic determinants with murine p39 procathepsin-L and human procathepsin-L. Preincubation of DM-4 cells with anti-p39 F(ab')-2 induced up to 45% decrease in their complement resistance. Pretreatment of DM-4 cells with anti-p39 Ab strongly inhibited their tumorigenicity and significantly decreased their metastatic potential in nude mice. Thus, the p41 C3-cleaving proteinase contributes to tumorigenicity and metastasis of human melamoma DM-4 cells.