phenanthrenes and Lymphoma--B-Cell

Epstein-Barr virus (EBV) infects various types of cells and mainly establishes latent infection in B lymphocytes. The viral latent membrane protein 1 (LMP1) plays important roles in transformation and proliferation of B lymphocytes infected with EBV. Triptolide is a compound of Tripterygium extracts, showing anti-inflammatory, immunosuppressive, and anti-cancer activities. In this study, it is determined whether triptolide inhibits proliferation of Epstein-Barr virus-positive B lymphocytes. The CCK-8 assays were performed to examine cell viabilities of EBV-positive B95-8 and P3HR-1 cells treated by triptolide. The mRNA and protein levels of LMP1 were examined by real time-PCR and Western blotting, respectively. The activities of two LMP1 promoters (ED-L1 and TR-L1) were determined by Dual luciferase reportor assay. The results showed that triptolide inhibited the cell viability of EBV-positive B lymphocytes, and the over-expression of LMP1 attenuated this inhibitory effect. Triptolide decreased the LMP1 expression and transcriptional levels in EBV-positive B cells. The activity of LMP1 promoter ED-L1 in type III latent infection was strongly suppressed by triptolide treatment. In addition, triptolide strongly reduced growth of B95-8 induced B lymphoma in BALB/c nude mice. These results suggest that triptolide decreases proliferation of EBV-induced B lymphocytes possibly by a mechanism related to down-regulation of the LMP1 expression.

Topics: Animals; Antineoplastic Agents; B-Lymphocytes; Cell Line, Tumor; Cell Proliferation; Diterpenes; Down-Regulation; Epoxy Compounds; Herpesvirus 4, Human; Humans; Lymphoma, B-Cell; Mice; Mice, Inbred BALB C; Phenanthrenes; Promoter Regions, Genetic; Viral Matrix Proteins

To investigate the antiproliferative effect of triptolide on B-NHL cell line Raji cells, to study its effect 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.. The effects of triptolide on the growth of Raji cells were studied by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium (MTT) assay. 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 the lymph nodes 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-1 alpha (rhSDF-1 alpha) or cultured lymph node stromal cells in vitro.. Triptolide inhibited the proliferation of B-NHL cell line Raji cells in a dose- and time-dependent manner with a 24-h IC50 value of 43.06 nmol/L and a 36-h IC50 value of 25.08 nmol/L. The expression of SDF-1alpha mRNA in lymph node stromal cells obtained from patients with NHL was decreased after treatment 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.. Triptolide can inhibit the proliferation of B-NHL cell line Raji cells. Moreover, triptolide is able to inhibit the migration of lymphoma cells via lymph nodes in vitro. The potential antitumor mechanisms of triptolide are related to the antiproliferative effect and the blockage of SDF-1/CXCR4 axis.

Topics: Antineoplastic Agents, Alkylating; Cell Line, Tumor; Cell Proliferation; Chemokine CXCL12; Chemotaxis; Diterpenes; Dose-Response Relationship, Drug; Epoxy Compounds; Humans; Lymph Nodes; Lymphatic Metastasis; Lymphoma, B-Cell; Lymphoma, Non-Hodgkin; Phenanthrenes; Plants, Medicinal; Receptors, CXCR4; RNA, Messenger; Stromal Cells; Tripterygium

In order to study the relation of antitumour mechanisms of triptolide with neovascularization, the effect of triptolide and tumour necrosis factor (TNF)-alpha on the expression of vascular endothelial growth factor (VEGF) in Raji cell lines and their effect on angiogenesis in human umbilical vein endothelial cells (HUVECs)-derived cell line ECV304 were investigated. The inhibitory rate of cells treated by triptolide detected by MTT; the ELISA was employed to study the VEGF content secreted by Raji cell lines; angiogenesis was tested by network formation of endothelial cells on Matrigel, and the mRNA level of VEGF was measured by RT-PCR. The results showed that treatment of Raji cells with triptolide resulted in significantly enhanced antiproliferative effects in dose- and time-dependent manner. The content of VEGF secreted by Raji cells was increased by TNF-alpha and was suppressed by triptolide (P < 0.01). The mRNA expressions of VEGF(165) and VEGF(121) (containing 165 and 121 amino acid residues, respectively) could be detected in all fractions. TNF-alpha augmented the expression of VEGF(165) and VEGF(121) mRNA when triptolide reduced the expression (P < 0.01). No network and cord were formed in control and triptolide group. There was tube formation on matrigel in the supernatants of Raji culture group and the supernatants groups treated by VEGF and TNF-alpha in Raji cell. It is concluded that the expressions of VEGF in Raji cells are increased by TNF-alpha and suppressed by triptolide. VEGF and TNF-alpha induce angiogenesis and triptolide inhibits angiogenesis in ECV304 cells.

Topics: Angiogenesis Inhibitors; Antineoplastic Agents, Alkylating; Cell Line; Diterpenes; Endothelial Cells; Epoxy Compounds; Humans; Lymphoma, B-Cell; Neovascularization, Physiologic; Phenanthrenes; RNA, Messenger; Tumor Cells, Cultured; Tumor Necrosis Factor-alpha; Umbilical Veins; Vascular Endothelial Growth Factors