Abstract:Objective To evaluate whether hypermethylation of calcitonin (CT) gene could serve as a transforming signal of myelodysplastic syndrome (MDS) to leukemia.Methods Bone marrow aspirates from 35 MDS patients, ...Abstract:Objective To evaluate whether hypermethylation of calcitonin (CT) gene could serve as a transforming signal of myelodysplastic syndrome (MDS) to leukemia.Methods Bone marrow aspirates from 35 MDS patients, including 25 refractory anemia (RA), 10 refractory anemia with excess of blasts (RAEB) or refractory anemia with excess of blasts in transformation (RAEBt) and 7 cases of acute myeloid leukemia (AML) transformed from MDS, were studied on methylation rate in 5'end of CT gene by polymerase chain reaction (PCR) technique using methylationsensitive endonuclease HpaⅡ with external references of undigested DNA and MspⅠ digested DNA and internal reference of 112 bp fragment containing codon 61 of Nras oncogene. The results were expressed as calcitonin gene methylation rate (CTMR) calculated from the densitometeranalyzed integral calculus of PCR products of 566 bp CT(a1), 112 bp Nras(b1) by using HpaⅡdigested DNA and PCR products of 566 bp CT(a0), 112 bp Nras(b0) by using undigested DNA according to the formula, CTMR = (a1/b1)/(a0/b0)×100%.Results The CTMRs in total 35 MDS, 25 RA, 10 RAEBt and 7 cases of AML transformed from MDS were 36.87%±25.10%, 28.12%±24.01%, 58.74%±16.49%, and 54.03%±7.06% respectively, significantly higher than that in control group (P<0.001, P<0.05, P<0.001 and P<0.001, respectively). Conclusion The results suggest that hypermethylation of CT gene occurs in early stage of leukemic transformation and CTMR might be a useful marker in predicting the transformation of MDS to AML.展开更多
Objective To analyze the clonal relationship between lymphocytes in peripheral blood(PB) and myeloma cell in bone marrow(BM) for proving the existence of circulating tumor cells in multiple myeloma(MM) patients. Met...Objective To analyze the clonal relationship between lymphocytes in peripheral blood(PB) and myeloma cell in bone marrow(BM) for proving the existence of circulating tumor cells in multiple myeloma(MM) patients. Methods Eighteen patients with MM who have no cytomorphologic plasma cells and CyIg+ cells in PB demonstrated by anti κ and anti λ MoAbs using ABC method were involved in the present study, including 3 cases in phases Ⅰ Ⅱ and 15 cases in phase Ⅲ. The complementary determining region 3 (CDR3) of immunoglobulin heavy chain (IgH) gene was amplified by polymerase chain reaction (PCR). We further analysed the single strand conformation of the PCR products by single strand conformation polymorphism (SSCP) analysis to detect the mononuclear cells in PB and BM of the patients simultaneously. Results The same PCR products of IgH CDR3 gene with BM samples were found in PB of 11 MM patients. The same PCR products and single strand conformation in both PB and BM were found in 9 cases. Conclusions This study has proved the presence of identical clonal malignant cells in PB and BM of MM patients. B cells are involved in the pathogenesis of MM.展开更多
文摘Abstract:Objective To evaluate whether hypermethylation of calcitonin (CT) gene could serve as a transforming signal of myelodysplastic syndrome (MDS) to leukemia.Methods Bone marrow aspirates from 35 MDS patients, including 25 refractory anemia (RA), 10 refractory anemia with excess of blasts (RAEB) or refractory anemia with excess of blasts in transformation (RAEBt) and 7 cases of acute myeloid leukemia (AML) transformed from MDS, were studied on methylation rate in 5'end of CT gene by polymerase chain reaction (PCR) technique using methylationsensitive endonuclease HpaⅡ with external references of undigested DNA and MspⅠ digested DNA and internal reference of 112 bp fragment containing codon 61 of Nras oncogene. The results were expressed as calcitonin gene methylation rate (CTMR) calculated from the densitometeranalyzed integral calculus of PCR products of 566 bp CT(a1), 112 bp Nras(b1) by using HpaⅡdigested DNA and PCR products of 566 bp CT(a0), 112 bp Nras(b0) by using undigested DNA according to the formula, CTMR = (a1/b1)/(a0/b0)×100%.Results The CTMRs in total 35 MDS, 25 RA, 10 RAEBt and 7 cases of AML transformed from MDS were 36.87%±25.10%, 28.12%±24.01%, 58.74%±16.49%, and 54.03%±7.06% respectively, significantly higher than that in control group (P<0.001, P<0.05, P<0.001 and P<0.001, respectively). Conclusion The results suggest that hypermethylation of CT gene occurs in early stage of leukemic transformation and CTMR might be a useful marker in predicting the transformation of MDS to AML.
文摘Objective To analyze the clonal relationship between lymphocytes in peripheral blood(PB) and myeloma cell in bone marrow(BM) for proving the existence of circulating tumor cells in multiple myeloma(MM) patients. Methods Eighteen patients with MM who have no cytomorphologic plasma cells and CyIg+ cells in PB demonstrated by anti κ and anti λ MoAbs using ABC method were involved in the present study, including 3 cases in phases Ⅰ Ⅱ and 15 cases in phase Ⅲ. The complementary determining region 3 (CDR3) of immunoglobulin heavy chain (IgH) gene was amplified by polymerase chain reaction (PCR). We further analysed the single strand conformation of the PCR products by single strand conformation polymorphism (SSCP) analysis to detect the mononuclear cells in PB and BM of the patients simultaneously. Results The same PCR products of IgH CDR3 gene with BM samples were found in PB of 11 MM patients. The same PCR products and single strand conformation in both PB and BM were found in 9 cases. Conclusions This study has proved the presence of identical clonal malignant cells in PB and BM of MM patients. B cells are involved in the pathogenesis of MM.
