BACKGROUND:
Vascular endothelial growth factor receptor 2 (VEGFR2) is primarily involved in
vascular endothelial growth factor (
VEGF)-mediated
signal transduction and
plays a critical
role in the
pathological angiogenesis that occurs in a number of
diseases, including
leukemia. Besides,
VEGF secreted by
leukemia cells also induces its own expression which leads to an enhanced
production of VEGFR2 which contributes to the
survival and proliferation of
leukemia cells.OBJECTrVE To evaluate the inhibitive effect of Lenti6/shVEGFR2 on the VEGFR2 expression and
leukemia growth in
mouse.
DESIGN:
A randomized, parallelized, controlled and open trial.
SETTING:
Department of
Pediatrics, the Second Affiliated
Hospital of
Sun Yat-sen
University;
Biotechnology Research Center,
Sun Yat-sen
University.MATERIALS The experiment had been done in the
laboratories for
Medical Research Center of the Second Affiliated
Hospital,
Sun Yat-sen
University and
Biotechnology Research Center,
Sun Yat-sen
University from May 2004 to January Lentiviral
RNAi Expression System was purchased from Invitrogen, Co.,Ltd.;
human VEGFR2 Mcb (PE) was purchased from R&D; CD31
immunohistochemistry kit was purchased from Boster, Co.,Ltd.; CD33-PE
fluorescence labeled antibody was purchased from BD, Co.,Ltd.transiently and expression
clone (Lenti6/shVEGFR2) was constructed, then cotransfected with ViraPowerTM
Packaging Mix pU6/shVEGFR2 entry
clone and transducting with Lenti6/shVEGFR2 expression
clone, the effect on the development of intravenous
xenograft leukemia mouse model, the distribution of
microvessels in
mouse bone marrow was observed after
leukemia model
mouse injected with recombinant
lentivirus (group B);
leukemia model
mouse injected with recombinant
lentivirus and
endothelial cell (group C);
leukemia model
mouse injected with
endothelial cell (group D). Through detecting changes of CD33 positive
cells and
microvessel density (MVD) in
bone marrow, observing peripheral
blood cell (PBC)smear and slice of
liver,
spleen, the effect of Lenti6/shVEGFR2 recombinant
lentivirus on
mouse leukemia was evaluated.mediated with
lentivirus on VEGFNEGFR2 paracrine and autocrine loops in
leukemia mouse.effective in inhibiting
HL60 cell. pU6/shVEGFR2 entry
clone constructed according to it had
cell inhibitory rate as high as after
transfection of pU6/shVEGFR2 entry
clone and transduction of Lenti6/shVEGFR2 expression
clone 48 hours after
transfection of pU6/shVEGFR2 entry
clone and transduction of Lenti6/shVEGFR2 expression
clone, the
cell growth inhibitive rates were
similar. However, the
cell growth inhibitive rate of entry
clone descended rapidly after 48 hours (P<0.01); which of expression
clone changed slowly, reaching the peak at 96 hours, dropped slightly, having no significance
mouse The amount of
HL60 cells in
bone marrow of groups A, B and C detected with
flow cytometry were (25.8%±4.9)%, (14.3%±5.1)%, (8.4±2.6)%, respectively (P<0.05); MVD in group C was obviously less than that in group D (P<0.05); The amount of
HL60 cells in
leukemia model
mouse injected with recombinant
lentivirus and
endothelial cell was the lowest as compared with the other groups.