Figure 6. Overexpression of Sema3E increases cancer cell proliferation and tumor growth in vivo.

Sema3E-overexpressing Mia-S3E cells as well as the control cells were orthotopically implanted into the pancreas of 6 week old nude mice (n=9 per group). Mice were sacrificed at 8 weeks post-implantation, and tumors were explanted and analyzed. A. Images of the tumors show that overall, mice injected with Mia-S3E cells had greater incidence of tumor formation as well as larger tumors compared to mice injected with the control Mia-VCtrl cells. Mia-S3E tumors also appeared more vascularized than the control tumors. Red circles indicate no tumor incidence in mice. B. Tumors in mice inoculated with Mia-S3E cells had greater mass than tumors in mice inoculated with Mia-VCtrl cells (Student's t-test, **p<0.01). C. Expression of CD31 (brown staining), a marker of endothelial cells, in representative tumor tissues from Mia-VCtrl and Mia-S3E groups. Greater CD31 expression in Mia-S3E tumors compared to Mia-VCtrl is indicative of the presence of more microvessels in the Sema3E-overexpressing tumors. D. Expression of Ki67 (brown staining), a marker of cell proliferation, in representative tumor tissues from Mia-VCtrl and Mia-S3E groups. Ki67 expression was greater and stronger in tumors from Mia-S3E group compared to the control group. E. The extent of Ki67 expression in tumor tissues was quantified using the ImmunoRatio application plugged into ImageJ; there was a significantly higher Ki67 expression in tumors from the Mia-S3E group compared to tumors from the Mia-VCtrl group (Student's t-test, ****p<0.0001). Red squares are small sections that are further magnified for a clear demonstration of positive staining. All data are represented as mean ± S.E.M.