Research Abstract |
In order to understand molecular mechanisms of hereditary blood disorders and develop the genetic diagnosis. I investigated beta-thalassemia as a disorder caused by dysfunction of the luxury gene, the globin gene, and hereditary methemoglobinemia as a disorder caused by impairment of the housekeeping gene, the NADH cytochrome b5 reducatase (b5R) gene. Seventy-one alleles of beta-thalassemia in Thailand, 45 alleles in Malaysia, 22 alleles in Taiwan and 17 alleles in Japan were analyzed. Nine, eleven, three and eight different mutations were identified in Thailand, Malaysia, Taiwan and Japan, respectively. I established the nonradioactive DNA diagnosis system using the PCR method. Generalized from of hereditary methemoglobinemia was analyzed and a T-C substitution at amino acid 127 was identified in the b5R gene. This mutation causes a significant conformation change in the nucleotide binding domain that affects electron transport, resulting in the disorder. For development of gene therapy of hemoglobinopathy, I characterized cultured cells isolated from patients of chronic myelogenous leukemia. I established the condition in which the fetal and adult globin genes were differentially expressed in KMOE cells. I found continuous erythroid differentiation in KU812 Cells without the addition of an inducer. I generated transgenic mice with the DNA fragment in which the human fetal and adult globin genes are juxtaposed and oriented in the same direction and found these genes were expressed in tissue-specific and developmental stage specific manner. These observations could be useful to set up gene therapy based on either activation of the fetal type gene or replacing with the exogenous gene.
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