Abstract 1551: Irradiation enhances tumor-homing ability of monocytes as cellular carrier.

Proceedings: AACR 104th Annual Meeting 2013; Apr 6-10, 2013; Washington, DC Tumor-homing ability of monocytes renders them as potential cellular delivery system for alternative cancer therapy, but the migration ability is reduced after reagents are up-taken. Approaches that can enhance monocyte tumor homing and migration abilities will facilitate the clinical value of using monocytes as cellular carrier. Previous studies have shown that irradiation (IR) could promote macrophage aggregation into the hypoxic regions. To investigate whether IR could enhance the infiltration of bone marrow-derived monocytes (BMDMs) into tumors, the infiltration of BMDMs prepared from GFP-transgenic mice were examined by fluorescence microscopy in murine prostate adenocarinoma TRAMP-C1 model. The results showed that IR did not increase the initial infiltration number of BMDMs, but enhanced the retention of monocytes within IR-treated tumors up to 2 weeks. This study also showed that BMDMs were able to uptake various imaging or therapeutic agents, but their mobility was decreased as the load was increased. However, when BMDMs were differentiated in IR-treated tumor condition medium (IR-CM), the nanoparticles-loaded migration loss was recovered in both in vitro and in vivo models. The prolong retention of monocytes within irradiated tumor tissues and the ability of IR-CM to enhance the migration ability of cargo-loaded BMDMs suggest that pre-conditioned monocytes could be a potential cellular carrier for target therapy following conventional RT. (This study is supported by NHRI-EX101-10132BI and NSC101-2627-M-007-001 grants) Citation Format: Ching-Fang Yu, Christopher W. Woo, Shao-Hua Lo, Chia-Yi Yen, Ji-Hong Hong, Chi-Shiun Chiang. Irradiation enhances tumor-homing ability of monocytes as cellular carrier. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1551. doi:10.1158/1538-7445.AM2013-1551