Recently it was noted that Toll-like receptor 5 (TLR5), the only protein recognition receptor of TLRs, high expressed in breast cancers and closely related to tumor development. In this study, we aimed to evaluate whether TLR5 could serve as a molecular target for breast cancer monitoring.
BALB/c mice were implanted with breast cancer line MCF-7 to establish a tumor-bearing mice model. Dynamic whole-body phosphor-autoradiography in vivo and ex vivo biodistribution studies were performed after 131I-recombinant Flagellin (rFliC, a specific ligand of TLR5) injection through the tail vein.
131I- rFliC was successfully prepared with Iodogen method. The uptake of MCF-7 to 131I-rFliC was quickly, and reached the highest point at 6h. Dynamic phosphor-autoradiography imaging showed clear tumor localization of tracer from 1 h onward. At 6 h after injection, tumor uptake was the highest. Pre-treatment with anti-TLR5 mAb obviously blocked tumor uptake of tracer. Biodistribution study reflected the same tendency, and obviously 131I- rFliC uptake of tumor was obtained at 3h after tracer injection, and reached a maximum of T/NT ratio(tumor to muscle,7.09 ± 1.86 %ID/g (percent injected dose per gram) at 24 h compared with naïve mice. Immunohistochemistry staining showed higher expression of TLR5 in tumor tissue, supported the results of phosphor-autoradiographagy and ex vivo biodistrbution studies.
These data suggested that radiolabeled rFliC could quickly localise in tumor tissue, which may be as a new tracer for non-invasive in vivo imaging of TLR5 in breast cancer.
Citation Format: Guihua Hou. In vivo mouse breast cancers-xenograft imaging with radiolabeled recombinant Flagellin. [abstract]. In: Proceedings of the CRI-CIMT-EATI-AACR Inaugural International Cancer Immunotherapy Conference: Translating Science into Survival; September 16-19, 2015; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(1 Suppl):Abstract nr B107.
- ©2016 American Association for Cancer Research.