Complete remission of gastric Burkitt's lymphoma after eradication of Helicobacter pylori

Burkitt＇s lymphoma is a highly aggressive non-Hodgkin lymphoma, often presenting in extra-nodal sites. It generally has a poor spontaneous outcome and needs aggressive treatment with systemic and intrathecal chemotherapy. Occurrence at the gastric site is rare. We report the case of a 39-year old woman who presented with a prominent ulcerated lesion of the antrum corresponding histologically to a Burkitt＇s lymphoma associated with He/icobacter py/ori （H pylori） infection. Interphase fluorescence in situ hybridization （FISH） demonstrated c-MYC gene rearrangement in tumour cells without BCL2 or BCL6 gene translocations. Ulcer healing and tumour regression with a complete histological response were obtained 8 wk after Hpylori eradication. In spite of this complete remission, taking into account the high risk of recurrence, the patient received systemic and intrathecal chemotherapy. Two years later, the patient remained in complete remission. This is the first report of a gastric Burkitt＇s lymphoma responding to Hpylori eradication. These findings raise the question of the potential role of H pylori in the pathogenesis of some gastric Burkitt＇s lymphomas, and show the importance of searching for and eradicating the bacteria in combination with conventional chemotherapy regimens.

Reversible Posterior Leukoencephalopathy Syndrome Sometimes Could be Irreversible： A Case Following Tumor Lysis Syndrome in Childhood Burkitt＇s Lymphoma

Reversible posterior leukoencepbalopathy syndrome （RPLS） was first described by Hinchey eta/. in 1996 as a clinical radiologic syndrome consisting of reversible cortical neuroIogic dysIhnction and brain imaging findings involving the posterior circulation, especially the occipital lobes.

Regulatory Effects of Deguelin on Proliferation and Cell Cycle of Raji Cells

Summary： The underlying mechanism of deguelin regulating the cell cycle in human Burkitt＇s lym phoma cell line Raji cells in vitro, and the cytotoxicity of deguelin to Raji cells and human peripheral blood monocular cells （PBMCs） were investigated. The effects of deguelin on the growth of Raji cells were studied by 3-（4, 5-dimethyl-2-thiazolyl）-2,5-diphenyl-2H-tetrazolium （MTT） assay. Apoptosis was detected through Hoechst 33258 staining. The effect of deguelin on the cell cycle of Raji cells was studied by a propidium iodide method. The expression levels of cyclin D1, P21 and pRb were examined by using Western blotting. The results showed that the proliferation of Raji cells was inhibited in the de guelin-treated group, with a 24-h IC5o value of 21.61 nmol/L and a 36-h IC50 value of 17.07 nmol/L. Proliferation in Raji cells was inhibited significantly by deguelin, while little change was observed in PBMCs. Deguelin induced G2/M arrest in Raji cells. The expression of cyclin D1, P21 and pRb was dramatically down-regulated by deguelin in a dose-dependent manner. It was concluded that deguelin could inhibit the proliferation of Raji cells by arresting the cells at GE/M phase and inducing the cell apoptosis. Moreover, deguelin selectively induced apoptosis of Raji cells with low toxicity to PBMCs. The antitumor effects of deguelin were related to the down-regulated expression of cyclin D1, P21 and pRb proteins.

Trichostatin A Regulates hGCN5 Expression and Cell Cycle on Daudi Cells in vitro

The expression of human general control of amino acid synthesis protein 5 （hGCN5） in human Burkitt＇s lymphoma Daudi cells in vitro, effects of Trichostatin A （TSA） on cell proliferation and apoptosis and the molecular mechanism of TSA inhibiting proliferation of Daudi cells were investigated. The effects of TSA on the growth of Daudi cells were studied by 3-（4, 5-dimethyl-2-thiazolyl）-2,5-diphenyl-2H-tetrazolium （MTT） assay. The effect of TSA on the cell cycle of Daudi cells was assayed by a propidium iodide method. Immunochemistry and Western blot were used to detect the expression of hGCN5. The proliferation of Daudi cells was decreased in TSA-treated group with a 24 h IC50 value of 415.3979 μg/L. TSA induced apoptosis of Daudi cells in a timeand dose-dependent manner. Treatment with TSA （200 and 400 μg/L） for 24 h, the apoptosis rates of Daudi cells were （14.74±2.04） % and （17.63±1.25） %, respectively. The cell cycle was arrested in G0/G1 phase （50, 100 μg/L） and in G2/M phase （200 μg/L） by treatment with TSA for 24 h. The expression of hGCN5 protein in Daudi cells was increased in 24 h TSA-treated group by immunochemistry and Western blot （P〈0.05）. It was suggested that TSA as HDACIs could increase the expression of hGCN5 in Daudi cells, and might play an important role in regulating the proliferation and apoptosis of B-NHL cell line Daudi cells.