FIGURE 6.

Inhibition of colon cancer growth favored by MSCs in vivo by HIF1α siRNA and VEGF siRNA. Transfections of VEGF siRNA and HIF1α siRNA into MSCs were performed using Lipofectamine. The MSCs siRNA-VEGF (1 × 10⁵) and MSCs siRNA-HIF1α (1 × 10⁵) were stimulated by both IFN-γ and TNF-α for 12 h and then mixed with C26 colon cancer cells (1 × 10⁶) for subcutaneous administration to BALB/c mice via the armpit area. Eighteen days after implantation, the animals were euthanized and their tumors were dissected. A, photographic illustration of tumors. B and C, the weight and volume of C26 tumors. D, CD34 immunostaining showing the numbers of newly formed vessels in colon cancer tissues: (I) control siRNA, (II) VEGF siRNA, (III) HIF1α siRNA. Bottom right, quantification of the vessels was estimated by counting five randomly chosen high power fields. *, p < 0.05.