| First Author | Brindle NR | Year | 2015 |
| Journal | PLoS One | Volume | 10 |
| Issue | 4 | Pages | e0120348 |
| PubMed ID | 25927437 | Mgi Jnum | J:229244 |
| Mgi Id | MGI:5751336 | Doi | 10.1371/journal.pone.0120348 |
| Citation | Brindle NR, et al. (2015) Deficiency for the cysteine protease cathepsin L impairs Myc-induced tumorigenesis in a mouse model of pancreatic neuroendocrine cancer. PLoS One 10(4):e0120348 |
| abstractText | Motivated by the recent implication of cysteine protease cathepsin L as a potential target for anti-cancer drug development, we used a conditional MycERTAM;Bcl-xL model of pancreatic neuroendocrine tumorigenesis (PNET) to assess the role of cathepsin L in Myc-induced tumor progression. By employing a cysteine cathepsin activity probe in vivo and in vitro, we first established that cathepsin activity increases during the initial stages of MycERTAM;Bcl-xL tumor development. Among the cathepsin family members investigated, only cathepsin L was predominately produced by beta-tumor cells in neoplastic pancreata and, consistent with this, cathepsin L mRNA expression was rapidly upregulated following Myc activation in the beta cell compartment. By contrast, cathepsins B, S and C were highly enriched in tumor-infiltrating leukocytes. Genetic deletion of cathepsin L had no discernible effect on the initiation of neoplastic growth or concordant angiogenesis. However, the tumors that developed in the cathepsin L-deficient background were markedly reduced in size relative to their typical wild-type counterparts, indicative of a role for cathepsin L in enabling expansive tumor growth. Thus, genetic blockade of cathepsin L activity is inferred to retard Myc-driven tumor growth, encouraging the potential utility of pharmacological inhibitors of cysteine cathepsins in treating late stage tumors. |
