RRC ID 58647
Author Takahashi Y, Yasui T, Tamari K, Minami K, Otani K, Isohashi F, Seo Y, Kambe R, Koizumi M, Ogawa K.
Title Radiation enhanced the local and distant anti-tumor efficacy in dual immune checkpoint blockade therapy in osteosarcoma.
Journal PLoS One
Abstract Radiation therapy has been long utilized as localized cancer treatment. Recent studies have also demonstrated that it has a distant effect by the enhanced immunity, but it rarely occurs. The purpose of this study was to investigate whether X-ray irradiation combined with anti-PD-L1 and anti-CTLA-4 antibodies (P1C4) provides a higher probability of this distant effect as well as enhanced local antitumor efficacy for osteosarcoma. LM8 mouse osteosarcoma cells were inoculated into both legs of C3H mice assigned to one of four groups, namely no treatment (No Tx), P1C4, X-ray irradiation (RAD) to the leg of one side, and combination (COMB) groups. Survival and treatment-related immune molecular changes were analyzed. Administration of P1C4 produced a tumor growth delay on day 30 in 18% of the mice. In contrast, combination therapy produced the strongest tumor growth inhibition not only at the irradiated tumor but also at unirradiated tumor in 67% of the mice. Accordingly, lung metastasis in the COMB group was strongly reduced by 98%, with a significant survival benefit. Unirradiated tumor in mice in the COMB group significantly recruited CD8 + tumor-infiltrating lymphocytes with a moderate reduction of Treg, producing a significant increase in the CD8/Treg ratio. These results suggest that radiation enhances the efficacy of P1C4 treatment against distant metastasis as well as local control in osteosarcoma. Our data suggest that radiation therapy combined with dual checkpoint blockade may be a promising therapeutic option for osteosarcoma.
Volume 12(12)
Pages e0189697
Published 2017-1-1
DOI 10.1371/journal.pone.0189697
PII PONE-D-17-15163
PMID 29253865
PMC PMC5734786
MeSH Animals Antibodies, Monoclonal / immunology Antineoplastic Agents / pharmacology Antineoplastic Agents / therapeutic use* Bone Neoplasms / radiotherapy* CD8-Positive T-Lymphocytes / cytology Cell Cycle Checkpoints / drug effects Cell Line, Tumor Lung Neoplasms / secondary Lymphocytes / cytology Lymphocytes, Tumor-Infiltrating / drug effects Mice Mice, Inbred C3H Neoplasm Metastasis Osteosarcoma / radiotherapy* Spleen / metabolism T-Lymphocytes, Regulatory / immunology
IF 4.011
Times Cited 6
Resource
Human and Animal Cells LM8(RCB1450)