Anti-Angiogenesis Therapy Based on the Bone Marrow- Derived Stromal Cells Genetically Engineered to Express Sflt-1 in Mouse Tumor Model - Genetic Engineering: Recent Developments in Applications - page 215

Figure 3. Anti-tumor effect in mouse LLC lung carcinoma model. Female C57BL/6 mice received i.v. injection
of 2×10 5 LLC cells in 100 µ l of PBS. Treatment with 1×10 6 Adv-GFP-sFlt-1 infected BmSCs (black rhombus),
1×10 6 Adv-GFP infected BmSCs (  , black quadrilateral), 1×106 uninfected BmSCs (black triangle) and 100 µ l
of 0.9% NaCl solution alone (black circularity) were administered i.v. from tail vein. A significant increase of
survival and decrease of metastases in sFlt-1-expressing BMSCs treated mice, compared with the controls (P <
0.05. By log-rank test), was found in this model.
inhibition of Angiogenesis and induction of Apoptosis
Systemically delivered BMSCs which express sFlt-1 were shown to induce ap-
parent inhibition of angiogenesis in vivo compared with control mice by immu-
nohistochemistry. Angiogenesis within tumor tissue was estimated by counting
the number of microvessels on the section staining with an anti-CD31 antibody.
Very few newborn microvessels were found around the tumor cells in the BMSCs-
sFlt-1 group, whereas abundant microvessels existed in three controls (Figure 4A,
B, P < 0.05). The inhibition of angiogenesis in mice treated with BMSCs express-
ing sFlt-1 was further confirmed in alginate encapsulation assay. The surface vessel
densities and the FITC-dextran uptake were apparently reduced in beads which
contain relatively high ratio of sFlt-1-bearing BMSCs to LLC cells (Figure 4C, D,
P < 0.05). Furthermore, an another alginate assay showed that the anti-angiogen-
esis effect of local production of sFlt-1 (came from the alginate beads being filled
with sFlt-1-bearing BMSCs and tumor cells, or the BMSCs intravenous injected)
was stronger than systemic production of sFlt-1 (came from the alginate beads
being filled with sFlt-1-bearing BMSCs and implanted in the distant site) (Figure
4-E and 4F). Being starved of the nourishment by the inhibition of angiogenesis
in neoplasm, augmentation of apoptosis of cancerous cells was detected by the
TUNEL assay (Figure 5, P < 0.05). The inhibition of angiogenesis and the conse-
quent induction of apoptosis underlie the mechanism of the metastases decrease
and the life-span prolongation in tumor-bearing mice.