Bivariate flow cytometric analysis of hl-60 cell cycle progression affected by polysaccharopeptide (psp) from coriolus versicolor mycelia

Abstract

Introduction: Anticancer agents generally target on cancer cells either by alter-ation of their cell cycle or induction of apoptosis or necrosis. The polysaccha-ropeptide (PSP)(I’m-Yunity™) isolated from the fermented mycelia of fungusCoriolus versicolor Cov-1™ strain exerts potent activity on inhibition of cell pro-liferation in a wide range of malignancies. However, whether the anticancermechanism(s) of PSP involves alteration of cell cycle is still not clear. The spe-cific aim of this study was to apply 5-bromodeoxyuridine (BrdUrd) to pulse labelactive synthesizing DNA to investigate the effect of PSP on cell cycle kinetics onhuman promyelocytic leukemic HL-60 cells. Methods: HL-60 cells were pulse-labeled with BrdUrd, treated with and without PSP (25, 400 _g/ml), and sampledat certain time intervals. The cell cycle kinetics was studied by usingBrdUrd/Propidium iodide (PI) bivariate flow cytometric analysis. Results: Theresults revealed that high dose of PSP reduced cells in G0/G1 phase, accumulat-ed cells in both S and G2/M phase. The DNA synthesis time and cancer potentialdoubling time was significantly extended in the HL-60 cells after PSP treatment.Conclusion: PSP retards cancer growth via elongation on the S phase, slows thecells returning to G1 from G2/M. Our data indicate that the interference on cellcycle progression is part of the anticancer mechanism(s) of PSP.