Objective: To investigate the mechanism of Paris forrestii (Takht.) H. Li (PCT3)-suppressing the proliferation of HL-60, K562, KG-1 and HT-93 cells.
Methods: cute myeloid leukemia cell lines such as HL-60, K562, KG-1 and HT-93 were treated with Paris forrestii (Takht.) H. Li (PCT3) for 24, 48, and 72 h, and MTT assay was employed to determine the cells proliferation. Meanwhile, the apoptosis of K562, HL-60, KG-1 and HT-93 cells were detected by flow cytometry after PCT3 (Control, 4 μg/ml, 8 μg/ml) treated for 24 h and the Western blot was performed to detect the expression of PARP,Caspase-3, MCL-1, BAX, BCL-2, P53, and P27. GAPDH was used as an internal loading control.
Results: MTT assay showed that Paris forrestii (Takht.) H. Li (PCT3) significantly inhibited the proliferation of HL-60, K562, KG-1 and HT-93 cells in concentration and time-dependent manners. Compared with the control group, the leukemia cell viabilities were significantly suppressed (r =0.9436; r =0.8623; r =0.9922; r =0.8918). Paris forrestii (Takht.) H. Li (PCT3) induced apoptosis of leukemia cells in a concentration dependent manner, compared with the control group (P＜0.05 or P＜0.01). Western blot revealed that PARP, a major enzyme in DNA damage repair, and Caspase-3 another one of the major executive apoptotic enzymes were cleaved in cell lines examined, and this cleavage was concentration dependent. Anti-apoptotic proteins such as MCL-1 and BCL-2 were down regulated by Paris forrestii (Takht.) H. Li (PCT3), and Pro-apoptotic protein BAX was upregulated. And the protein of tumor suppressor gene P53 and its downstream signaling protein P27 increased.
Conclusion: Paris forrestii (Takht.) H. Li (PCT3) can inhibit the proliferation of leukemia cells by activating endogenous apoptosis pathway, and provide a potential new drug selection for clinical treatment of AML leukemia.