SHP-1 gene's methylation status of Daudi lymphoma cell and the demethylation effect of 5-aza-2'-deoxycytidine / 中华血液学杂志

<p><b>OBJECTIVE</b>To explore the transcription regulation of 5-aza-2'-deoxycytidine(5-Aza-CdR) on SHP-1 gene and its effects on Daudi cell line growth.</p><p><b>METHODS</b>MTT method and flow cytometry were used to detect the growth and apoptosis of Daudi cells after treated with different dosage of 5-Aza-CdIR. Bisulfite sequencing PCR ( BSP) , T-A cloning and sequence analysis were evaluated for methylation status. The SHP-I mRNA and protein were determined by reverse transcription polymerase chain reaction (RT-PCR) ,immunohistochemistry.</p><p><b>RESULTS</b>(1)After 7 d treatment with 2. 00 micromol/L of 5-Aza-CdR, all cytosines (C) in Daudi cells genome DNA were converted to thymidine, and SHP-1 mRNA and protein expressed again in the cells while those Cs in CpG dinucleotides in untreated Daudi cells remained Cs; (2)5-Aza-CdR inhibited the cell growth,The effects within certain extent were dose and time dependent:after 72 h treatment with 5-Aza-CdR at 200. 00, 20. 00, 2. 00 and 0. 20 micromol/L, the inhibitive rates were 72. 0% , 65. 1%, 51. 5%, 28.8% ,23.4% respectively; (3) 5-Aza-CdR increased apoptosis rate of tumor cells with a dose and times dependent manner within certain extent, too:at the 1,3,5 d treatment with 5-Aza-CdR 2. 00 micromol/L,the apoptosis rates were 2. 3% ,10. 8 % and 17. 1% ; respectively. (4) 5-Aza-CdR also changed cell cycle of tumor cells: at 24 h treatment with 5-Aza-CdR 2.00 micromol/L,92. 7% tumor cells stopped at S phase and G, phase cells were increased gradually with time.</p><p><b>CONCLUSION</b>DNA promoter hypermethylation is associated with SHP-1 gene silence in Daudi lymphoma cell line. 5-Aza-CdR could effectively cause demethylation and inhibit the growth of tumor cell by reactivating the gene transcription.</p>

Clinical and pathological reassessment of 493 cases of non-Hodgkin's lymphomas according to current WHO classification of lymphoid neoplasms / 中华病理学杂志

<p><b>OBJECTIVE</b>To investigate the clinical and pathological features of non-Hodgkin's lymphoma (NHL) and to evaluate the applicability of the new WHO classification of lymphoid neoplasms.</p><p><b>METHODS</b>According to the new WHO classification, a total of 500 cases of non-Hodgkin's lymphoma diagnosed during the period 1992 - 2003 were reviewed and reappraised with their morphological, immunological and clinical characteristics. Clinical survival analysis was performed in 156 cases that accompanied with follow-up data.</p><p><b>RESULTS</b>Among 500 cases previously diagnosed as lymphomas, 493 cases (98.6%) were confirmed to be NHL, of which B-cell neoplasms was 69.0% and T/NK-cell neoplasms 29.8%. Overall, 6 subtypes including diffuse large B-cell lymphoma (DLBCL), follicular lymphoma (FL), unspecified peripheral T-cell lymphoma (PT-un), precursor T-lymphoblastic lymphoma (T-LBL), extranodal marginal zone B-cell lymphoma of MALT type (MALT) and B-small lymphocytic lymphoma (B-SLL) were among the most common subtypes. In pediatric and young patient populations, the most common subtypes were LBL, DLBCL and Burkitt's lymphoma. The frequency of LBL in all patients, especially in the juniors, was much higher than those reported outside Mainland China, and the frequency of FL was much higher than the reported in Mainland China. The frequency of FL was much higher than the reported in Mainland China. Clinical survivals among different histological subtypes of NHL varied considerably with statistic significance (P < 0.001). Marginal zone B-cell lymphoma and SLL demonstrated the best prognosis, LBL and PT-un both the worst, whereas DLBCL and FL had an intermediate prognosis, however, subgrouping of FL according to WHO classification did not reveal a significant survival difference (P > 0.05).</p><p><b>CONCLUSIONS</b>Basing upon the results of a comprehensive survey on the morphologic features, immunophenotyping and clinical data of the above cases, the new WHO classification of lymphoid neoplasms is practical and easily applicable for routine pathological evaluation of lymphoproliferaive disorders and in guiding the clinical management. It appears that the diagnostic and grading criteria for FL in Mainland China need to be re-evaluated.</p>