恶性血液病细胞中tankyrase表达与端粒酶活性关系研究

为研究以白血病为主的恶性血液病细胞中端粒酶活性正向调控基因tankyrase的表达与端粒酶活性的关系并初步探讨tankyrase对端粒酶活性调控的机理和意义 ,以实时定量RT PCR技术对髓细胞系白血病细胞株K5 6 2 ,HL 6 0 ,U937,NB4 ,THP 1,HEL ,Dami,T淋巴细胞性白血病细胞株 6T CEM ,Jurkat和B细胞淋巴瘤细胞株Raji中tankyrase的表达进行检测 ,同时检测端粒酶逆转录酶hTERT的表达确定端粒酶活性 ,并以经磁珠分离的正常人CD3 ,CD19 和CD33 细胞和 10份正常人骨髓单个核细胞做对照。结果发现 :tankyrase在恶性血液病细胞株中的表达明显高于正常对照 (U =19,P <0 .0 1) ,其中髓系白血病细胞株中的表达高于正常人CD33 细胞 ,T淋巴细胞性白血病细胞株和B细胞淋巴瘤细胞株中的表达分别高于正常人CD3 和CD19 细胞。髓系恶性血液病细胞株tankyrase的表达 (0 .0 0 32± 0 .0 0 10 )明显低于淋系恶性血液病细胞株的表达 (0 .0 12± 0 .0 0 16 ) (F =2 3,P <0 .0 1)。Tankyrase与hTERT的表达呈正相关 (相关系数为 0 .395 ,P <0 .0 5 )。结论 :tankyrase在恶性血液病细胞株中呈高表达 ,与端粒酶活性呈正相关 ,提示tankyrase可能是恶性血液病中端粒酶活性增高的原因之一。

Study on the Expression of Tankyrase in Malignant Hematopoietic Cells and Its Relation with Telomerase Activity

To study the expression of tankyrase (a positive regulator of telomerase activity) in malignant hematopoietic cells and its relation with telomerase activity, the method of realtime quantitative PCR with fluorescence probe hybridization were used to measure expression of tankyrase and hTERT in myeloid leukemia cell lines K562, HL-60, U937, NB4, THP-1, HEL, Dami and T lymphocytic leukemia cell lines 6T-CEM, Jurkat and B-cell lymphoma cell line Raji. CD3(+), CD19(+) and CD33(+) cells separated from normal human mobilized peripheral blood by immunomagnetic bead system and 10 mononuclear cell samples separated from bone marrow of normal individuals were served as normal controls. The results indicated that the expression of tankyrase in malignant hematopoietic cell lines was significantly higher than that in normal controls (U = 19, P < 0.01). Its expression in myeloid leukemia cell lines is higher than in normal CD33(+) cells, the expression in T lymphocytic leukemia and B-cell lymphoma cell lines is higher than in CD3(+) and CD19(+) cells respectively. Its expression in myeloid malignant hematopoietic cell lines is significantly lower than in lymphocytic ones (0.0032 +/- 0.0010 vs. 0.012 +/- 0.0016, F = 23, P < 0.01). The expression of tankyrase correlated positively with hTERT (Spearman correlation coefficient is 0.395, P < 0.05). It is concluded that tankyrase is overexpressed in malignant hematopoietic cell lines, that may be one of the causes of high-produced telomerase activity in malignant hematopoietic diseases.