ZO-1 gene methylation status and its clinical significance in children with non-Hodgkin lymphoma / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To investigate the methylation status of zonula occludens-1 (ZO-1) gene promoter and its clinical significance in children with stage IV non-Hodgkin lymphoma (NHL) and to provide a basis for further etiological study and early diagnosis of this disease.</p><p><b>METHODS</b>Fifty-five children with a confirmed diagnosis of stage IV NHL (40 cases of T-NHL and 15 cases of B-NHL) were selected as the case group, and 20 children with diseases other than hematologic malignancies were selected as the control group. Bone marrow samples were collected from these subjects. Methylation-specific PCR (MS-PCR) was applied to evaluate the methylation status of ZO-1 gene promoter, and the integrated optical density (IOD) was determined. RT-PCR was used to measure the mRNA expression of ZO-1.</p><p><b>RESULTS</b>MS-PCR showed that the methylated bands of ZO-1 gene promoter were found in 39 (70.9%) of 55 patients in the case group before treatment, while no ZO-1 gene promoter methylation was detected in the control group. With close tracking of 47 cases in the study group, consisting of 32 cases of T-NHL and 15 cases of B-NHL, the rates of ZO-1 gene promoter methylation prior to treatment were 72% and 67%, respectively, (P>0.572). The cases of T-NHL and B-NHL showed no significant changes in methylation rate in the early and middle phases of chemotherapy (P>0.05), but they showed significant changes in methylation rate in the late phase of chemotherapy (P<0.05). RT-PCR showed that the NHL cases carrying methylated ZO-1 gene had no mRNA expression of ZO-1, while all children in the control group had mRNA expression of ZO-1. There was no linear relationship between the total number of peripheral blood leukocytes and ZO-1 gene IOD (r=0.093, P=0.575); a positive correlation was found between the number of malignant cells in bone marrow and ZO-1 gene IOD (r=0.669, P<0.001).</p><p><b>CONCLUSIONS</b>ZO-1 gene shows a hypermethylation status in children with NHL, and the methylation level is positively correlated with the number of malignant cells in bone marrow. ZO-1 may be used as a novel molecular marker in early diagnosis, outcome assessment, prognostic evaluation, and detection of minimal residual disease.</p>

Detection of malignant lymphoma in children by using Id4 gene methylation indicator / 中华实用儿科临床杂志

Objective To study and discuss what part does methylated Id4 gene participate in malignant lymphoma stage Ⅳ by detecting the extent of how much Id4 gene has been methylated in afflicted children who suffer from malignant lymphoma.Methods Forty-two patients who had diagnosed with malignant lymphoma [Hodgkin's disease (HD),Non-Hodgkin's lymphoma(NHL)] were selected as study group.Their chemotherapy stages of pre-treatment,early-treatment,mid-treatment,post-treatment and clinical remissions or relapse throughout the entire treatment had been traced.At each stage the expression of methylated Id4 gene mRNA was detected by methylation-specific polymerase chain reaction (MS-PCR) and compared with the control group.The control group consisted of 20 non-neoplastic hematologic disorder affected children as sample donors.Results MS-PCR detection:in pre-treatment stage,there were 27 patients who were found methylated or partially methylated Id4 genes.Methylated ratio was thus at 64.3％ (27 patients out of a total of 42 patients).Those 27 patients were actively traced down along with different stages of treatment (21 NHL patients,6 HD patients).Before NHL there was 55.6％ methylated Id4 gene (15 cases out of 27 NHL patients).During chemotherapy treatment,there was 51.9％ of methylated Id4 gene positive (14 cases out of 27 patients).In post chemotherapy treatment,there was 48.1％ of methylated Id4 gene positive (13 cases out of 27 patients).Totally there were 9 patients showed clinical recovery after chemotherapy.There was 44.4％ of traceable methylated Id4 gene after recovered chemotherapy patients (4 recovered patients still carrying positive reading of methylated Id4 gene out of totally 9 recovered patients).There were 2 patients relapsed,with traceable methylated Id4 gene re-appeared in them afterwards.Throughout different treatment stages,there was no significant correlation in the treatment result and the appearance of methylated Id4 gene in early treatment stages (all P ＞ 0.05).But in latter treatment of chemotherapy,the correlation started to emerge (P ＜ 0.05) ; The overall statistics on NHL and HD share the same statistical pattern on different stages (all P ＞ 0.05).The control group had 20 patients,none of them had methylated Id4 gene.The study group showed noticeable difference in methylated Id4 gene before and after the experiment (P ＜ 0.001).RT-PCR result showed that before chemotherapy treatment,all of those who carried methylated Id4 gene had no expression of mRNA,by comparison to the control1 group which all had expression of mRNA.Conclusions Methylated Id4 gene is closely related in affected children who suffer from malignant lymphoma and its complications.The expression of Id4 gene is depressed when it has been methylated.The state of methylated Id4 gene is changed as patient's condition changed,so the methylated Id4 gene is thus a possible indicator of early diagnostic tool for children lymphoma.