Kobayashi Hiroko, Motoyoshi Naomi, Itagaki Tadashi, Tabata Keiichi, Suzuki Takashi, Inokuchi Norio
School of Pharmacy, Nihon University, Funabashi, Chiba 274-8555, Japan.
Biosci Biotechnol Biochem. 2013;77(7):1486-91. doi: 10.1271/bbb.130133. Epub 2013 Jul 7.
RNase Po1 is a guanylic acid-specific ribonuclease (a RNase T1 family RNase) from Pleurotus ostreatus. We determined the cDNA sequence encoding RNase Po1 and expressed RNase Po1 in Escherichia coli. A comparison of the enzymatic properties of RNase Po1 and RNase T1 indicated that the optimum temperature for RNase Po1 activity was 20 °C higher than that for RNase T1. An MTT assay indicated that RNase Po1 inhibits the proliferation of human neuroblastoma cells (IMR-32 and SK-N-SH) and human leukemia cells (Jurkat and HL-60). Furthermore, Hoechst 33342 staining showed morphological changes in HL-60 cells due to RNase Po1, and flow cytometry indicated the appearance of a sub-G1 cell population. The extent of these changes was dependent on the concentration of RNase Pol. We suggest that RNase Po1 induces apoptosis in tumor cells.
