To construct basic fibroblast growth factor (bFGF) eukaryotic expression vector and to evaluate the possibility of bFGF gene therapy in orthopedic disease, the pCD-rbFGF recombinant plasmid was constructed by cloning rat basic fibroblast growth factor (bFGF) cDNA into an eukaryotic expression vector, pcDNA3. Rat osteoblasts were transfected with pCD-rbFGF plasmid by lopofectin mediated gene transfer, the transient expression was detected by streptavidin-biotin-enzyme complex (SABC) method. It was observed that the expression of rat bFGF gene was detected 72 h after transfected distinctly. Basic fibroblast growth factor gene therapy is a method of potential for a wide array of orthopedic diseases.
To assess the value of CD34+ cells transferred exogenous Fas ligand (FasL) in inducing apoptosis of human leukemic cells, the CD34+ cells transfected with FasL or without, pretreated with mitomycin C, was mixed with leukemic cell line U937 cells in presence or absence of daunorubicin (DNR) or cytosine arabinoside (Ara-C). After 18 h, apoptosis of cells was detected by FCM and TUNEL. Induced for 18 h by CD34+ cells transfected with FasL or without, the ratio of apoptosis of U937 cells was (5.0±1.3)%, (10.8±0.6)% (P<0.01), respectively. Induced by FasL+CD34++DNR, FasL+CD34++Ara-C, the ratio was (13.4±1.0) % (P<0.05), (17.9±1.3)% (P<0.01), respectively. The result demonstrated that CD34+ cells transfected with exogenous FasL could induce apoptosis of human leukemic cells and showed a cytotoxic synergistic effect when used in combination with chemotherapeutic drugs, suggesting that it was possible to develop a new method in treatment of leukemia.