Recombinant methioninase combined with doxorubicin (DOX) regresses a DOX-resistant synovial sarcoma in a patient-derived orthotopic xenograft (PDOX) mouse model.

Abstract

Synovial sarcoma (SS) is a recalcitrant subgroup of soft tissue sarcoma (STS). A tumor from a patient with high grade SS from a lower extremity was grown orthotopically in the right biceps femoris muscle of nude mice to establish a patient-derived orthotopic xenograft (PDOX) mouse model. The PDOX mice were randomized into the following groups when tumor volume reached approximately 100 mm3: G1, control without treatment; G2, doxorubicin (DOX) (3 mg/kg, intraperitoneal [i.p.] injection, weekly, for 2 weeks; G3, rMETase (100 unit/mouse, i.p., daily, for 2 weeks); G4 DOX (3mg/kg), i.p. weekly, for 2 weeks) combined with rMETase (100 unit/mouse, i.p., daily, for 2 weeks). On day 14 after treatment initiation, all therapies significantly inhibited tumor growth compared to untreated control, except DOX: (DOX: p = 0.48; rMETase: p < 0.005; DOX combined with rMETase < 0.0001). DOX combined with rMETase was significantly more effective than both DOX alone (p < 0.001) and rMETase alone (p < 0.05). The relative body weight on day 14 compared with day 0 did not significantly differ between any treatment group or untreated control. The results indicate that r-METase can overcome DOX-resistance in this recalcitrant disease.

• Authors: Kentaro Igarashi, Kei Kawaguchi, Shukuan Li, Qinghong Han, Yuying Tan, Emily Gainor, Tasuku Kiyuna, Kentaro Miyake, Masuyo Miyake, Takashi Higuchi, Hiromichi Oshiro, Arun S Singh, Mark A Eckardt, Scott D Nelson, Tara A Russell, Sarah M Dry, Yunfeng Li, Norio Yamamoto, Katsuhiro Hayashi, Hiroaki Kimura, Shinji Miwa, Hiroyuki Tsuchiya, Fritz C Eilber, Robert M Hoffman
• Journal: Oncotarget (Oncotarget) Vol. 9 Issue 27 Pg. 19263-19272 (Apr 10 2018) ISSN: 1949-2553 [Electronic] United States
• PMID: 29721200 (Publication Type: Journal Article)