Abstract
BackgroundPolysaccharopeptide (PSP) from Coriolus versicolor (Yunzhi) is used as a supplementary cancer treatment in Asia. The present study aims to investigate whether PSP pre-treatment can increase the response of the human leukemia HL-60 cells to apoptosis induction by Camptothecin (CPT).MethodsWe used bivariate bromodeoxyuridine/propidium iodide (BrdUrd/PI) flow cytometry analysis to measure the relative movement (RM) of the BrdUrd positively labeled cells and DNA synthesis time (Ts) on the HL-60 cell line. We used annexin V/PI flow cytometry analysis to quantify the viable, necrotic and apoptotic cells. The expression of cyclin E and cyclin B1 was determined with annexin V/PI flow cytometry and western blotting. Human peripheral blood mononuclear cells were used to test the cytotoxicity of PSP and CPT.ResultsPSP reduced cellular proliferation; inhibited cells progression through both S and G2 phase, reduced 3H-thymidine uptake and prolonged DNA synthesis time (Ts) in HL-60 cells. PSP-pretreated cells enhanced the cytotoxicity of CPT. The sensitivity of cells to the cytotoxic effects of CPT was seen to be the highest in the S-phase and to a small extent of the G2 phase of the cell cycle. On the other hand, no cell death (measured by annexin V/PI) was evident with the normal human peripheral blood mononuclear cells with treatment of either PSP or CPT.ConclusionThe present study shows that PSP increases the sensitization of the HL-60 cells to undergo effective apoptotic cell death induced by CPT. The pattern of sensitivity of cancer cells is similar to that of HL-60 cells. PSP rapidly arrests and/or kills cells in S-phase and did not interfere with the anticancer action of CPT. PSP is a potential adjuvant to treat human leukemia as rapidly proliferating tumors is characterized by a high proportion of S-phase cells.
Highlights
Polysaccharopeptide (PSP) from Coriolus versicolor (Yunzhi) is used as a supplementary cancer treatment in Asia
Effect of CPT and PSP on the viability, necrosis and apoptosis human promyelocytic leukemia cell line (HL-60) cells and peripheral blood mononuclear cells (PBMCs) With a S-phase synchronization strategy, we showed that pre-treatment of low dose PSP (25 μg/ml) for 72 hours was able to enhance the cytotoxicity of CPT (1 μM) to the HL-60 cells
PSP is a useful anticancer agent against rapidly proliferating tumor cells characterized by high proportion of S-phase cells exemplified by the HL-60 cells
Summary
Polysaccharopeptide (PSP) from Coriolus versicolor (Yunzhi) is used as a supplementary cancer treatment in Asia. The polysaccharopeptide (PSP) extract of the Chinese medicinal mushroom Coriolus versicolor (Yunzhi) has been used in Asia to treat cancer as well as to alleviate weakness, improve immunological activities, appetite and comfort for patients [1]. The strong immunomodulatory effects of PSP such as elevation of IL-2, natural killer cell activity and T-cell proliferation may be beneficial to advanced cancer patients with depressed immunity [2,3]. CPT kills cancer cells by interfering with the function of DNA topoisomerase I (TopI) during DNA replication in the S-phase [7,8]. The cell sensitivity to cytotoxic effects of CPT was reported to reach the highest in the late S-phase and early G2 [9]. CPT demonstrated remarkable anticancer activity in preliminary clinical trials and produced side effects such as leucopenia [10]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
