Expression of Escherichia coli Nissle1917 L-asparaginaseⅡ-encoding gene in E. coli BL21 and anti-tumor activity

Abstract:

[Objective] To study the anti-tumor activity of L-asparaginase II (ASP) of Escherichia coli Nissle1917. [Methods] L-AsparaginaseⅡ gene was amplified from the genome of E. coli Nissle1917 and inserted on the expression vector pET28a. The final expression vector pET28a-asp was transformed into E. coli BL21(DE3) for ASP expression. SDS-PAGE and LC-MS were used to determine the correct expression of ASP. After purification by nickel-affinity chromatography, the recombinant ASP was used to treat mouse 4T1 breast tumor cells, Hep-3B human hepatoma cells and Human Umbilical Vein Endothelial Cells (HUVEC). [Results] L-AsparaginaseⅡgene from E. coli Nissle1917 was successfully expressed in E. coli BL21(DE3) and identified by LC-MS. The purified L-asparaginaseⅡinhibited the growth of 4T1 and Hep-3B tumor cells while not HUVEC. [Conclusion] The L-asparaginaseⅡ of E. coli Nissle1917 was active on 4T1 and Hep-3B tumor cells while not on normal tissue cells. Our results will be helpful for the further study on the active mechanism of ASP and its application in solid tumors therapy.

Key words:L-AsparaginaseⅡ, Escherichia coli, Clone, Antineoplastic