Figure 3.

IL-6R blockade inhibits growth of tumors and metastases and prevents metastatic progression. (A) 1833-IL-6 cells (1 x 10⁵) were injected into the tail vein (n = 10/group) and were randomized to receive weekly intraperitoneal injections of control IgG (C) or IL-6RAb (IL-6R) given at the time of injection. Tumor growth was determined weekly by normalized BLI. Representative lung images are shown. (B) qRT-PCR for GFP relative to β-actin (tumor cells: GFP⁺) was performed to quantify tumor lung colonization described in A (n = 5). (C) 1833-IL-6 cells (1 x 10⁶) were injected into the MFP of athymic nude mice and randomized to receive weekly intraperitoneal injections of control IgG (C) or IL-6RAb (IL-6R). Growth was determined weekly by normalized BLI. (D) qRT-PCR for GFP was performed on the lungs of mice (n = 5) in C. Quantification of CD11b⁺ and Gr1⁺ cells/hpf in the lungs (E) and MFP tumors (F) of mice described in A and C, respectively (n = 10 sections/group; **P < .01, *P < .05).