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 ce...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.展开更多
Objective： To investigate the role of Spl as transcription factor required for transactivation of LRP16 gene by estrogen. Methods： Specific antibodies of ERα and Spl were used to precipitate the target DNA/protein...Objective： To investigate the role of Spl as transcription factor required for transactivation of LRP16 gene by estrogen. Methods： Specific antibodies of ERα and Spl were used to precipitate the target DNA/protein complexes of MCF-7 cells at different time points after estrogen treatment （Chromatin immunoprecipitation assay）, the promoter region of LRP16 gene was amplified by semi-nested polymerase chain reaction （snPCR）. Small interfering RNA （siRNA） against Spl was transiently cotransfected with LRP16-Luc （containing the region from -213bp to -126bp of LRP16 gene promoter）in MCF-7 cells. The luciferase activities were measured by dual-luciferase assay. Results： The results of chromatin immunoprecipitation assay showed that Spl protein directly bound to the -213bp to -126bp region of LRP16 gene, and ERα could enhance the affinity of Spl to DNA. Spl-siRNA specifically decreased the transactivation of LRP16-Luc by 1713-estradio1 to 70-80%. Conclusion： The estrogen-induced transactivation of the human LRP16 gene was mediated by Spl protein. Moreover, the interactions of ERα/Sp1 functional complex with LRP16 promoter DNA were required for enhanced LRP16 gene transactivation.展开更多
基金Supported by National Natural Science Foundation (39970318)Millitary Medical Research Foundation (01J007)National Basic Research Program (2005CB522400).
文摘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.
基金This work was supported by the NationaNatural Science Foundation of China (No.30572096) andBeijing Natural Science Foundation (No.5052024).
文摘Objective： To investigate the role of Spl as transcription factor required for transactivation of LRP16 gene by estrogen. Methods： Specific antibodies of ERα and Spl were used to precipitate the target DNA/protein complexes of MCF-7 cells at different time points after estrogen treatment （Chromatin immunoprecipitation assay）, the promoter region of LRP16 gene was amplified by semi-nested polymerase chain reaction （snPCR）. Small interfering RNA （siRNA） against Spl was transiently cotransfected with LRP16-Luc （containing the region from -213bp to -126bp of LRP16 gene promoter）in MCF-7 cells. The luciferase activities were measured by dual-luciferase assay. Results： The results of chromatin immunoprecipitation assay showed that Spl protein directly bound to the -213bp to -126bp region of LRP16 gene, and ERα could enhance the affinity of Spl to DNA. Spl-siRNA specifically decreased the transactivation of LRP16-Luc by 1713-estradio1 to 70-80%. Conclusion： The estrogen-induced transactivation of the human LRP16 gene was mediated by Spl protein. Moreover, the interactions of ERα/Sp1 functional complex with LRP16 promoter DNA were required for enhanced LRP16 gene transactivation.
