儿童急性淋巴细胞白血病MOST-1基因表达研究

Expression of MOST-1 mRNA in Bone Marrow Mononuclear Cells from Patients with Acute Lymphoblastic Leukemia

目的 研究 MOST- 1基因在儿童急性淋巴细胞白血病骨髓单个核细胞中的表达 ,了解其与免疫分型和治疗反应的关系。方法 采用半定量 RT- PCR方法测定了 17例新发儿童急性淋巴细胞白血病 (其中 AL L- L33例 )患者骨髓单个核细胞 MOST- 1基因的表达水平 ;PCR产物经 DNA序列测定证实。结果 MOST- 1基因仅表达于儿童急性淋巴细胞白血病 L3型 ,而 L1 和 L2 均无表达 ;3例 AL L - L3患者治疗前外周血幼稚细胞比例分别为72 %、6 7%和 12 % ,骨髓白血病细胞比例分别为 98%、94 %和 6 7% ,前两例 L3患者 MOST- 1m RNA的表达水平分别为另一例 L3患者的 3倍和 2倍。 2例 L3患者经正规诱导完全缓解后无 MOST- 1基因表达。结论 MOST- 1基因表达于儿童急性淋巴细胞白血病 L3型 。

Objective To investigate the MOST-1 mRNA expression in bone marrow(BM) mononuclear cells in children with acute lymphoblastic leukemia, and to explore its association with immunophenotype and treatment response. Methods Semiquantitative RT-PCR was employed to study the MOST-1 mRNA expression in BM mononuclear cells separated by Ficoll density gradient method. The MOST-1 expression levels were represented by the ratio of MOST-1 band pixels against its corresponding housekeeping gene β-actin mRNA band pixels determined by GDS8000 densitometry and GelWork-1 analysis software. The PCR product was eluted and sequenced, and its sequence was confirmed by Pairwise BLAST search. Results A total of 17 children with acute lymphoblastic leukemia were studied. MOST-1 mRNA was exclusively expressed in the mononuclear cells from 3 patients with ALL-L 3 type. However, there was no MOST-1 mRNA expression in other 14 children with ALL-L 1 or ALL-L 2, irrespective of their initial peripheral WBC count and blast cell percentage in peripheral blood and bone marrow. The MOST-1 mRNA expression levels in two of the ALL-L 3 patients with higher blast cell percentages in peripheral blood and bone marrow were 3- and 2-fold respectively as compared with that in the third ALL-L 3 child with lower initial blast cell load. MOST-1 mRNA expression was no longer detected in the two ALL-L 3 children after complete remission with combination chemotherapy. Conclusion MOST-1 was expressed in the bone marrow mononuclear cells in patients with ALL-L 3, and its expression level was somewhat related to tumor cell burden. It might be implicated in the leukemogenesis of ALL-L 3 and might serve as an indicator of tumor burden and thus a useful guide for clinical management.