Figure 2.

Effect of inhibition of Lyn expression on Ewing’s sarcoma tumor growth, tumor-induced bone lysis, and lung metastases in vivo. A, cell clones were obtained from TC71 cells after transfection with a control vector (TC/si-control) or Lyn siRNA-expressing plasmid (TC/Lynsi-8 and TC/Lynsi-10). Lyn inhibition was confirmed by Western blot and kinase assay. The relative fold was determined by densitometry. Each band was adjusted with the β-actin loading control. B, TC71, TC/si-control, or TC/Lynsi clones 8 and 10 cells (2 × 10⁵) were injected into the right tibia of nude mice. Radiographic images were taken 3 wk later. Representative bone tumor images from each group. C, TC71, TC/si-control, or TC/Lynsi clones 8 and 10 cells were inoculated into the tibias of nude mice. Four weeks later, digitized radiographic images were taken using a MX-20 Specimen Radiograph System. ^†, each osteolytic bone tumor lesion was graded from 0 to 4 as described in Materials and Methods (with 4 being the most lytic). The average severity of bone destruction in each group was the mean grading score of five different animals. The incidence of lung metastases was determined at 8 wk. ^‡, number of mice with lung tumors/total number of mice. The percentage of mice with metastases is in parentheses. ^§, P < 0.05; **, P = 0.058, compared with TC/si-control mouse group using χ² test. D, mice received a s.c. injection of TC71 cells. Three days later, mice were divided into three groups and given intratumoral injections of PEI:si-control, PEI:Lynsi, or no treatment. Tumor size was measured at various time points. *, P < 0.01, compared with the untreated or PEI:si-control group.