Experimental Study Of Ligustrazine On HL-60 Cells Proliferation And Invasive Ability

[Background]Ligustrazine, also named as tetramethylpyrazine, is one of the active ingredients of the Chinese herb Ligusticum Wallichii Franchat and can be artificially synthetized now. It is well documented that Ligustrazine can get through blood brain barrier. Ligustrazine has been widely applied in clinic in China. It has been reported that Ligustrazine has anti-tumor effect and can counteract the multi-drug resistance property of tumor cells. However, there are seldome reports about the effect of Ligustrazine on tumor metastasis; and at present, there were no reports about the therapeutic effects of Ligustrazine on infiltration and metastasis of leukemic cells.[Objective]To investigate the effect of Ligustrazine on the inhibition of proliferative and invasive ability of human acute myeloid leukemia cell strain, HL-60, in vitro. In this study, we are going to discuss the mechanism of extramedullary leukemic invasion and the potential application of this observation in treating leukemia.[Method] 1 MTT assay was used to observe the proliferative inhibition effect of Ligustrazine on HL-60 cells.2 The adhesion ability of HL-60 cells to ECM was measured by MTT assay and the effect of different concentration (50μg/ml, 100μg/ml, 150μg/ml) of Ligustrazine on the inhibition of adhesive capability of HL-60 cells was observed. In vitro invasive ability was measured by Minicell chamber which was reconstituted using matrigel basement membrane matrix and the effect of different concentration (50μg/ml, 100μg/ml, 150μg/ml) of Ligustrazine on the inhibition of invasive ability of HL-60 cells was observed at the same time.3 The mRNA levels of MMP-2 and MMP-9 were determined by RT-PCR technique and the protein levels of MMP-2 and MMP-9 were determined by immunocytochemistry technique.[Results]1 Ligustrazine could inhibit the proliferation of HL-60 cell at the concentration between 400μg/ml and 2000μg/ml in a dose dependent manner.2 Different concentration (50μg/ml, 100μg/ml, 150μg/ml) of Ligustrazine could inhibit the adhesive capability of HL-60 cells to Matrigel and Fibronectin in a dose dependent manner. dependent manner.4 The MMP-2 mRNA level was downregulated by different concentration (50μg/ml, 100μg/ml, 150μg/ml) of Ligustrazine after 48 hours. However, MMP-9 mRNA level was not affected. The expression level of MMP-2 protein was also downregulated by different concentration (50μg/ml, 150μg/ml) of Ligustrazine after 48 hours, but not the expression level of MMP-9 protein.[Conclusion]1 Ligustrazine can inhibit the proliferative and invasive ability of HL-60 cells.2 Ligustrazine decreases the invasive ability of HL-60 cells by down-regulation of MMP-2 expression.