Fig. 7

Therapeutic potential of KAI1 and peptide to inhibit angiogenesis in tumors and prevent OIR-induced neovascularization. a B16 cells were subcutaneously injected in C57BL/6 mice with or without KAI1 supplement [combination of [1] Kai1-O/E 10T1/2 supernatant to provide anti-angiogenic LIF and [2] rhKAI1 to directly bind and inhibit VEGF and PDGF]. Left, tumor growth images are presented. Scale bar, 5 mm. Right, quantification of the obtained results (Means ± SEM, 3 biological replicates). b PC3 (human prostate cancer cell line) cells were subcutaneously injected into NSG mice in combination with or without KAI1 supplement. Left, tumor growth images are presented. Scale bar, 5 mm. Right, quantification of the obtained results (Means ± SEM, 5 biological replicates). c CD31 (red) immunostaining, and DAPI (blue) staining of human prostate (PC3) tumors treated with or without KAI1 supplement. Scale bar, 100 μm. d Schematic figure of dual anti-angiogenic effect of KAI1 in tumors. e Neonatal C57BL/6 mice with OIR at postnatal day 15 (P 15) were treated or not treated with a single intravitreal injection (1 μL) of vehicle only [PBS] (n = 4 retinas), rhKAI1 (600 ng), wild-type peptide KAI WT (200 ng) (n = 4 retinas), or mutant peptide KAI M (200 ng) (n = 4 retinas). Whole-mount retinas were stained with isolectin-B4 conjugated to Alexa Fluor 594 red-fluorescent dye. Top, Representative confocal microscopy images of retinas of OIR neonatal C57BL/6 mice at P17. Bottom, quantification of neovascularization in the retinas of OIR neonatal C57BL/6 mice treated or not treated with rhKAI1, KAI WT or KAI M peptides. Scale bar, 500 μm. f Mice were injected with matrigel and MDA-MB 231 cells in the presence of PBS alone (vehicle) or 200 ng KAI WT or M peptide (n = 5). After 23 days, the plugs were removed and the angiogenic responses were evaluated. Top, tumor volume was presented and bottom, representative IF images of tumors are shown. g Quantitative results of tumor volume (left) and CD31 intensity (right). Endothelial cells were visualized with CD31 (red) immunostaining, and DAPI (blue) staining of human breast cancer (MDA-MB231) treated with KAI WT or KAI M peptides. Scale bar, 20 μm. ns not significant, *p < 0.01, **p < 0.05, ***p < 0.001