Fig. 5. Interruption of GITR/GITRL signaling in patient-derived sarcomatoid xenograft inhibits tumor growth.

a Tumours were collected from clinical mesothelioma patients with epithelioid MPM subtype and sarcomatoid MPM subtype and subcutaneously implanted into NOD/SCID mice on right flank region to generate xenografted mice. Mice with xenografted tumours that were the size of 30–70 mm³ received intraperitoneal PBS on day 0 and 7, 5 mg/kg cisplatin on day 0 and 7, or 400 µg anti-GITR mAb on day 0 and 200 µg on day 7. b Representative images of H&E stain for morphologic analysis and immunohistochemistry staining for GITRL and GITR expression. c Tumor size was decreased in sarcomatoid xenograft mice treated with cisplatin (n = 4) or anti-GITR mAb (n = 4) and decreased in epithelioid xenograft mice treated with cisplatin (n = 5), whereas anti-GITR mAb group (n = 4) had no effect on tumor size compared with PBS group (n = 4 of sarcomatoid xenograft, n = 6 of epithelioid xenograft). *P < 0.05; **P < 0.01 vs PBS injected group, determined by Mann–Whitney test.