Fig 6. Therapeutic benefit of pre-resectional RFA in distant tumors depends on CD8⁺ T cell immunity.

(A) Time schedule outlining different treatments used in the experiements. BALB/c mice (5 mice/group) were injected s.c. with 10⁶ CT26 cells into the left flank on day 0 to establish primary tumor, followed by injection of 10⁵ CT26 cells i.v. on day 7 to establish secondary tumors in the lungs. Primary tumors or skin (at region outside of primary tumor; upper back) were treated as indicated with sham surgery, resection (Rxn), or RFA on days 10 or 17. (B) Representative photographs of lungs harvested from mice that underwent the indicated treatments to their primary s.c. tumor. (C) Bars represent the average number of lung metastases. (B-C), Data are representative of two independent experiments (n = 5 mice per group); n.s., not significant. *P <0.01 compared with all other groups. (D) Depleting α-CD8 antibody (Ab) or isotype antibody (400 ug/mouse) was injected i.p. every 7 days immediately post-RFA therapy. Lungs were harvested on day 30 and the number of metastases relative to the isotype control group was quantified. n = 3 mice per group. *P <0.05, sham versus RFA.