Objective To investigate the methylation status of LRP15 gene in acute leukemia （AL） patients and its role in the tumorigenesis. Methods The methylation of LRP15 promoter and first exon of bone marrow mononuclear cells in 73 patients with AL, 10 with chronic leukemia （CL）, 9 with hematological benign diseases, and 20 healthy transplantation donors was analyzed by using methylation specific polymerase chain reaction. The methylation of LRP15 gene promoter and first exon in COS7, K562, and HL60 cell lines was also assayed. Resuits No LRP15 gene promoter methylation was detected in COS7 cell line. LRP15 gene promoter was methylated in K562 and HL60 cell lines. No deletion of LRP15 gene was detected in all samples. In nearly all French-American-British leukemia subtypes, we found that frequency of LRP15 methylation in adult patients with AL was 71.23% （ 52/73 ）. There was no detectable methylation in any of the 20 healthy donors and 8 chronic myeloid leukemia patients. The difference in frequency of LRP15 methylation between AL patients and healthy donors or CL patients （ 10.00%, 1/10） was significant （P 〈0.01 ）. Hypermethylation of LRP15 gene was found in 57.14% （16/28） of newly diagnosed AL patients, 83.33% of relapsed AL patients respectively, which was significantly different （ P 〈 0.05 ）. We also demonstrated LRP15 methylation in 55.56% （5/9） adults with benign hematological diseases. Conclusions LRP15 methylation changes are common abnormalities in leukemia. LRP15 is postulated to be a tumor suppressor gene.
Li-ping Dou Chang Wang Zhou-min Xu Hui-yuan Kang Hui Fan Fang-ding Lou Li Yu
Background：The diagnosis of myelodysplastic syndrome （MDS）,especially hypoplastic MDS,and MDS with low blast counts or normal karyotype may be problematic.This study characterized ID4 gene methylation in patients with MDS and aplastic anemia （AA）.Methods：The methylation status ofID4 was analyzed by bisulfite sequencing polymerase chain reaction （PCR） and quantitative real-time methylation-specific PCR （MethyLight PCR） in 100 patients with MDS and 31 patients with AA.Results：The MDS group had a higher ID4 gene methylation positivity rate （22.22%） and higher methylation levels （0.21 [0-3.79]） than the AA group （P 〈 0.05）.Furthermore,there were significant differences between the hypoplastic MDS and AA groups,the MDS with low blast count and the AA groups,and the MDS with normal karyotype and the AA groups.The combination of genetic and epigenetic markers was used in much more patients with MDS （62.5% [35/56]） than the use of genetic markers only （51.79% [29/56]）.Conclusions：These results showed that the detection ofID4 methylation positivity rates and levels could be a useful biomarker for MDS diagnosis.
