Fig. 2: Tumor burden depends upon expression of 4Ig-B7-H3.

a–d HeLa WT B7-H3, KO or rescue xenografts were implanted on the right flank of nu/nu mice. Tumor growth was monitored and plotted as aggregates (a) or independently by mouse (b) and endpoint survival was documented in a Kaplan-Meier plot c. Statistically significant difference in survival between HeLa CD276^+/+ (n = 5) and HeLa CD276^-/- (n = 9) was determined (p < 0.0018, Mantel-Cox Log-rank test). HeLa KO cells were used to re-express 4Ig-B7-H3 using a lentiviral vector versus negative control. Rescue expression of 4Ig-B7-H3 in tumor xenografts was measured. Lentiviral re-expression of 4Ig-B7-H3 (HeLa KO C6 LV 4Ig-B7-H3; n = 10) reduced the median survival (p = 0.0057) compared to KO xenografts (HeLa KO C6 LV Neg; n = 9) (p < 0.0057, Mantel-Cox Log-rank test). d Endpoint histology was performed and representative H&E staining and human 4Ig-B7-H3 immunostaining is shown. Images captured with 4X objective, scale bars, 50 µm. e–h. SKOv3-ip-FLuc orthotopic tumors were injected intraperitoneally into nu/nu mice. Tumor growth was monitored by firefly luciferase bioluminescence e and plotted as aggregates (Mean ± SEM) f. Endpoint tumors (week 5) were collected and nodule numbers g and tumor weight h were measured. KO of B7-H3 tumor expression resulted in decreased tumor burden as determined by bioluminescence (p = 0.0385), number of nodules (p < 0.001) and tumor weight (p < 0.001).