Antiproliferative activity of L-asparaginase ofTetrahymena pyriformison human breast cancer cell lines

✍ Scribed by D. A. Kyriakidis; S. A. E. Tsirka; I. K. Tsavdaridis; S. N. Iliadis; A. H. Kortsaris

• Publisher: Springer
• Year: 1990
• Tongue: English
• Weight: 416 KB
• Volume: 96
• Category: Article
• ISSN: 0300-8177
• DOI: 10.1007/bf00420905

✦ Synopsis

Purified L-asparaginase of Tetrahymena pyriformis is a multi-subunit enzyme exhibiting protein kinase activity as well. The enzyme's L-asparaginase activity is affected by its phosphorylation state. Both native and dephosphorylated L-asparaginase show antiproliferative activity on three breast cancer cell lines (T47D, BT20 and MCF-7) and on Walker 256 cells. These cells do not possess measurable L-asparaginase or L-asparagine synthetase activity. When T47D cells are treated for different times with L-asparaginase and then placed in fresh medium, the growth of cells treated for 1, 3, or 6 hours is initiated and parallels control curve, while the growth of cells treated for 24 or 48 hours with L-asparaginase stays at the same inhibitory level (24 h treatment) or continues to drop (48 h treatment). Addition of D-asparagine, a competitive inhibitor of T. pyriformis L-asparaginase, counteracts the antiproliferative activity of L-asparaginase, indicating that L-asparaginase and not the kinase activity is responsible for that effect.