Voon Hsiao Phin Joanna, Wardan Hady, Vadolas Jim
Cell and Gene Therapy Research Group, The Murdoch Children's Research Institute, The University of Melbourne, Royal Children's Hospital, Flemington Road, Parkville 3052, Melbourne, Australia.
Haematologica. 2008 Aug;93(8):1238-42. doi: 10.3324/haematol.12555. Epub 2008 Jun 12.
beta-thalassemia is an inherited hemoglobinopathy caused by defective synthesis of the beta-globin chain of hemoglobin, leading to imbalanced globin chain synthesis. Excess alpha-globin precipitates in erythroid progenitor cells resulting in cell death, ineffective erythropoiesis and severe anemia. Decreased alpha-globin synthesis leads to milder symptoms, exemplified in individuals who co-inherit alpha- and beta-thalassemia. In this study, we investigated the feasibility of utilizing short-interfering RNA (siRNA) to mediate reductions in alpha-globin expression. A number of siRNA sequences targeting murine alpha-globin were tested in hemoglobinized murine erythroleukemic cells. One highly effective siRNA sequence (si-alpha 4) was identified and reduced alpha-globin by approximately 65% at both the RNA and the protein level. Electroporation of si-alpha 4 into murine thalassemic primary erythroid cultures restored alpha :beta-globin ratios to balanced wild-type levels and resulted in detectable phenotypic correction. These results indicate that siRNA-mediated reduction of alpha-globin has potential therapeutic applications in the treatment of beta-thalassemia.
β地中海贫血是一种遗传性血红蛋白病，由血红蛋白β珠蛋白链合成缺陷引起，导致珠蛋白链合成失衡。过量的α珠蛋白在红系祖细胞中沉淀，导致细胞死亡、无效造血和严重贫血。α珠蛋白合成减少会导致症状较轻，如同时遗传α和β地中海贫血的个体。在本研究中，我们研究了利用小干扰RNA（siRNA）介导降低α珠蛋白表达的可行性。在血红蛋白化的小鼠红白血病细胞中测试了许多靶向小鼠α珠蛋白的siRNA序列。鉴定出一个高效的siRNA序列（si-α4），其在RNA和蛋白质水平上均使α珠蛋白降低约65%。将si-α4电穿孔导入小鼠地中海贫血原代红系培养物中，可使α:β珠蛋白比率恢复到平衡的野生型水平，并导致可检测到的表型纠正。这些结果表明，siRNA介导的α珠蛋白降低在β地中海贫血治疗中具有潜在的治疗应用。
