Suppression of multiple myeloma tumor growth in vivo by transfection of platelet factor 4 or 17-70 cDNA / 中国实验血液学杂志

This study was purposed to investigate the effects of viral vector-mediated gene transfer of platelet factor 4 (PF4) or 17-70 cDNA on cell growth of multiple myeloma (MM) in vivo. Full length and p17-70 cDNA of PF4 were cloned into virapower system to transfect packing cell line 293 and produce lentiviral vectors. 3 multiple myeloma cell lines were transferred platelet factor 4 or 17-70 cDNA by lentiviral vectors. SCID-rab mice models of multiple myeloma were established by injecting U266 multiple myeloma cells selected. The human light chain proteins and VEGF in serums of mice were detected every 2 weeks. The volumes and vascular density of tumors as well as survival time of mice were observed. The results showed that the MM cells expressing foreign genes were identified and screened. There were significant difference of VEGF levels in the supernatants of MM cells between each groups (p<0.01). The SCID-rab models of U266 cells were established successfully. There were significant differences in light chain protein and VEGF in serums among three groups (p<0.01). The light chain protein and VEGF in mice serums of 17-70 cDNA groups were less than that of PF4 group (p<0.01). The light chain protein and VEGF in mice serums of PF4 group were less than that of control group (p<0.01). There were significant differences in the tumor volumes and the vascular density of tumor among 3 groups (p<0.05). The results also showed that there were significant differences of overall survival in 3 different groups of SCID-rab MM models. The overall survival in control group was shortest as compared with other groups (p<0.05). It is concluded that the cell growth of multiple myeloma is suppressed in vivo by transfection of platelet factor 4 or 17-70 cDNA and the overall survival of transfected mice will be prolonged.

The ultrastructure study of membrane surface of the bone marrow CD34+ cells with the atomic force microscope / 中国实验血液学杂志

Human CD34(+) hematopoietic cells, a distinctive cell population containing hematopoietic stem/progenitor cells (HSPC), have the capability to highly self-renewal, differentiation into all lineages of committed progenitor cells and reconstitution of both long-term hematopoiesis and immunefunctions after transplantation. CD34(+) hematopoietic cells from bone marrow (BM) recently have been employed for treating neoplastic and genetic disorders. This study was aimed to investigate membrane surface ultrastructures of bone marrow CD34(+) cell from mormal persons and leukemia patients and to compare their morphologic differences by using atomic force microscope (AFM). BM was collected from 5 normal donors and 6 leukaemia patients. All samples were layered on Ficoll-Paque gradients (specific gravity 1.077 g/ml) to separate the mononuclear cells. After that CD34(+) cells were purified by immuno-magnetic bead separation and evaluated with a FACS Calibur, these cells were detected by AFM of tapping mode inair. At lest 20 cells per samples were observed. The results showed that most of CD34(+) hematopoietic cells were like circle plate, the diameter was 10 - 14 microm. The surface of CD34(+) hematopoietic cell membrane was comparatively complex. The surface of CD34(+) hematopoietic cell membrane appeared as granular, with packed particles. With the region analysis function of IP2.1 software, the region of 2 microm x 2 microm was selected and four parameters of the surface (maximum peak-to-valley distance, average roughness, root-mean-squared roughness and mean height) were measured. Values of the 4 parameters showed that the characteristic parameters of CD34(+) HSPC from leukaemia were higher than that from normal person. It is concluded that AFM has specific advantages in analyzing cell membrane in the nanometer level and can gain more information. With the help of analysis software, AFM can be a helpful tool for fast leukaemic diagnosis and CD34(+) hematopoietic cells selection.