Inhibitory Effects Of Triptolide On Cell Proliferation And Metastasis In Non-Hodgkin's Lymphoma

Part I Antiproliferative effects of triptolide on Burldtt'slymphoma cell line Raji cells in vitro[Objiective] To investigate the antiproliferative effect of triptolide on Burkitt'slymphoma cell line Raji cells in vitro.[Method] Raji cells were grown in RPMI-1640 culture medium supplementedwith 10% fetal calf serum(FCS) and 100 u/ml penicillin and 100 u/ml streptomycinat 37°C in a 5% CO₂ incubator. Raji cells were treated with different concentrationsof triptolide ((0, 6.25 nmol/L, 12.5 nmol/L, 25 nmol/L, 50 nmol/L, 100nmol/L)for 0, 24 h, 36 h, 48 h, 60 h, and 72 h. The effects of triptolide on the growth of Rajicells were studied by 3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium(MTT) assay.[Results] Triptolide inhibited the proliferation of Raji cells in a dose- andtime-dependent way with a 24-h , 36-h , 48-h, 60-h, and 72-h IC₅₀ value of 43.06 ,25.08 nmol/L, 7.32 nmol/L, 2.66 nmol/L and 0.58 nmol/L.[Conclusion] Triptolide could inhibit the proliferation of Burkitt's lymphoma cellline Raji cells in vitro. Part II Inhibitary effect of triptolide on lymph node metastasis in patients with non-Hodgkin lymphoma by regulating SDF-1/CXCR4axis in vitro[Objective] To investigate the effect of triptolide on lymph node metastasis in patients with non-Hodgkin's lymphoma (NHL) in vitro, and to explore the underlying mechanism regulating SDF-1/CXCR4 axis.[Methods] The effects of triptolide on SDF-1 mRNA expression in lymph node stromal cells from patients with NHL were determined by reverse transcriptase-polymerase chain reaction (RT-PCR). The effects of triptolide on CXCR4 expression on lymphoma cells freshly isolated from lymph node of these patients were studied by flow cytometric analysis. Chemotaxis assays were performed to observe the effects of triptolide on migration of primary lymphoma cells towards recombinant human SDF-1α (rhSDF-1α) or cultured lymph node stromal cells in vitro.[Results] The expression of SDF-1α mRNA in lymph node stromal cells obtained from patients with NHL was decreased treated by triptolide at concentrations of 25 and 50 nmol/L for 24 h. Flow cytometry analysis showed that the CXCR4 expression on primary lymphoma cells were downregulated gradually in a dose-dependent manner following triptolide treatment. Chemotaxis assays revealed that the migration of freshly isolated lymphoma cells towards either rhSDF-1 or cultured lymph node stromal cells was markedly inhibited by the addition of triptolide in vitro, and the inhibition was dose-dependent.[Conclusions] Triptolide was able to inhibit the migration of lymphoma cells via lymph node in vitro. The potential antitumor mechanisms of triptolide are related to the blockage of SDF-1/CXCR4 biological axis. Part III Effects of triptolide on the expression and activity of focal adhesion kinase in Burkitt's lymphoma cell line Raji cells[Objective] To observe the effects of triptolide on the expression and activity offocal adhesion kinase in Burkitt's lymphoma cell line Raji cells.[Methods] Raji cells were grown in RPMI-1640 culture mediumsupplemented with 10% fetal calf serum and 100 u/ml penicillin and100 u/ml streptomycin at a concentration of 25 nmol/L for 4 h and 24 h.Western blot and immunoprecipitation-tyrosine kinase assay were usedto study the expression and activity of focal adhesion kinase inBurkitt's lymphoma cell line Raji cells.[Results] The expression of focal adhesion kinase on Burkitt'slymphoma cell line Raji cells was decreased treated by 25 nmol/Ltriptolide for 24h (P<0.05) as compared with the control; moreover, there wasa decrease in the activity of the focal adhesion kinase on cultured Rajicells after treated with 25 nmol/L triptolide for 4 h and 24 h (4hP<0.05,24hP<0.01) .[Conclusion] The expression and activity of focal adhesion kinaseon cultured Raji cells were regulated by triptolide, and the regulationmight be important in the tumor-pathogenesis.