High Expression of Human Clotting Factor-Ix Cdna in the Bone-Marrow Stroma Cells of Hemophilia-B Patient

Hemophilia B, a serious bleeding disorder, is an inherited X chromosome-linked disease caused by the deficiency or inactiveness of human clotting factor IX (FIX). The conventional clinical treatment of plasma infusion is expensive and associated with a high risk of infection with HIV and herpes virus. In 1987, Anson eb al, first transduced human FIX cDNA into rat and human skin fibroblasts and advanced the idea of gene therapy for hemophilia B. Recently, FlX cDNA has been expressed in skin fibroblasts, myoblasts, hepatocytes, endothelial cells and keratocytes at different expression levels (see table 1), in which the clinical trial of gene therapy for hemophilia B using autologous skin fibroblasts method by Xue et al. has achieved an efficient, safe and feasible result([1]). In order to increase the expression level of FIX and search for an alternative new target cell, we first selected bone marrow stroma cells (EMS) of hemophilia B patient as target cells and transduced a new-constructed retroviral vector LNCIX into them. Gene-modified EMS cells can secrete active FIX proteins at the level of (5.6+/-10.8) mu g/10(6) cells/24 h. This study provides a simple and promising way of gene therapy for hemophilia B.