Figure 2.

Effects of neutrophil depletion on cancer progression. (A) Murine ID8-KRAS cells (2×10⁶) were intraperitoneally injected into 31 mice (iso-type, n=15; and anti-Ly6G, n=16). The mice were intraperitoneally injected with 250 µg of anti-Ly6G mAb or matched isotype in 0.5 ml of PBS every 3 days from day 7 after inoculation of ID8-KRAS cells. For the mice survival analysis, the end point was determined as 'body weight (BW) = 23 g', and mice were sacrificed when their BW exceeded 23 g after inoculation. The log-rank test was used to detect differences (Kaplan-Meier survival curves). (B) ID8-KRAS-injected mice were treated with anti-Ly6G mAb (n=9) or isotype control mAb (n=8) from day 10 after the inoculation of ID8-KRAS cells, and the ascites were obtained on day 16 after washing with 3 ml of PBS. The ascites from no cancer mice were also obtained after washing with 3 ml of PBS (n=6). The interleukin (IL)-6 concentration in ascites of the 3 groups (no cancer, ID8-KRAS treated with isotype mAb, and ID8-KRAS treated with anti-Ly6G mAb) was analyzed using specific ELISA kits. Error bars represent the means ± SEM. Statistical analysis was performed using the Student's t-test. The P-value was adjusted using the Holm's method (^*P<0.05).