Telomerase Activity of the Blood Cells in Patients with Myeloproliferative Disorders in Childhood

目前尚不清楚骨髓增生性疾病；儿童MD（青少年慢性髓性白血病，JCML，短暂性骨髓增生性疾病，TMD）是否为真正的恶性肿瘤。为了解决这个问题，我们检测了md患者血细胞的端粒酶表达。在10例急性淋巴细胞白血病患者的所有白血病细胞中发现端粒酶活性；所有人。末端限制片段；白血病细胞的TRF长度比正常血细胞短，但差异不显著。在2例JCML患者和1例TMD患者中，也发现端粒酶活性，但血细胞中的TRF长度与年龄匹配的正常供者的血细胞长度在8kb至15kb之间。由于正常淋巴细胞和造血祖细胞表达端粒酶活性，因此需要进一步的研究来阐明血液恶性肿瘤与端粒酶活性的关系。在接下来的实验中，我们检测了三名皮森综合征患者血细胞中线粒体DNA缺失的比例。Southern blot分析表明，外周血和骨髓中线粒体DNA缺失的比例与血液学表现的严重程度有相关性。我们将进一步研究线粒体异常与MD患者血细胞端粒酶活性的关系。

It is not known exactly whether myeloproliferative disorders ; MD in childhood (juvenile chronic myelogenous leukemia ; JCML,transient myeloproliferative disorder ; TMD) are ture malignacy or not. To address this question, we examined telomerase expression of the blood cells in patients with MD.Telomerase activity was found in all leukemic cells of 10 patients with acute lymphoblastic leukemia ; ALL.Terminal restriction fragment ; TRF lengths in the leukemic cells were shorter than that in normal blood cells, although it was not significant. In two patients with JCML and one with TMD,telomerase activity was also found, but TRF lengths in the blood cells were within 8kb to 15kb consist with those of blood cells from age-matched normal donors. Because normal lymphocytes and hematopoietic progenitor cell express telomerase activity, further investigation is needed to clarify the relationship between hematological malignacy and telomerase activiry.In the next experiment, we examined the proportion of delected mitochondrial DNA in blood cells from three patients with Peason syndrome. Southern blot analysis represented that the proportion of deleted mitochondorial DNA in peripheral blood and bone marrow has a tendency to correlate to the severity of hematological manifestation.We will study the relationship between mitochondorial abnormality and telomerase acticity in blood cells from patients with MD in future.