Anti-IL–20 mAb treatment suppressed tumor growth and protected against cancer-induced osteolysis <i>in vivo</i>.

<p>(A-D) PC–3 cells were injected (s.c.) into the mammary fat pads of SCID mice. One day later, the mice were injected (s.c.) with PBS, 7E (10 mg/kg), or mIgG (10 mg/kg; n = 4 per group) three times per week. (A) Tumor size was measured using a caliper. (B) Mice were killed 40 days after they had been injected with PC–3 cells, and their tumors were collected and weighed. (C-D) Tumor tissue samples from each group (n = 4) were isolated at the end of the experiment. The expression of IL–20 and cathepsin G in tumor tissue was analyzed using RT-qPCR with specific primers. *p < 0.05, **p < 0.01 versus mIgG controls. Data are means ± SD. Data are representative of 3 independent experiments with similar results. (E-F) 7E treatment protected against bone loss and lessened bone density decrement in intratibial PC-3-injected osteolytic mice. PC–3 cells (2×10⁵/100 μl) were slowly injected into the bone marrow cavity of the tibia. Mice were injected i.p. with PBS, 7E (10 mg/kg), or mIgG (10 mg/kg) (n = 5 in each group) three times per week. Healthy controls were not injected with cancer cells. (E) The tibial metaphysis was taken from healthy control mice and mice with PC-3-induced osteolysis. Representative micro-CT scans are shown for each group. (F) Tibial BMD was measured and the results expressed in percentages relative to healthy control values. *p < 0.05 versus mIgG controls. Data are shown as means ± SD. Data are representative of 3 independent experiments with similar results. BMD, bone mineral density; micro-CT, micro-computed tomography.