Site-specific transfer of an intact β-globin gene cluster through a new targeting vector

The ideal gene-therapy vector for treating genetic disorders should deliver intact therapeutic genes and their essential regulatory elements into the specific "safe genomic site" and realize long-term, self-regulatory expression. For beta-thalassemia gene therapy, viral vectors have been broadly used, but the accompanying insertional mutation and immunogenicity remain problematic. Hence, we aimed to develop new non-viral vectors that are efficient and safe in treating diseases. As previous studies have demonstrated that physiological expression of P-globin genes requires both a 5' locus control region and 3' specific elements, we constructed a new human chromosome-derived targeting vector to transfer the intact P-globin gene cluster into K562 cells. The whole P-globin gene cluster was precisely integrated into the target site and expressed in a self-regulatory pattern. The results proved that the human chromosome-derived vector was specifically targeted to the human genome and this could provide a novel platform for further gene therapy research. (c) 2007 Elsevier Inc. All rights reserved.