PDF file - 3693K,Supplemental Figure S1. TAp63 isoforms induce BMP signaling;Supplemental Figure S2. ΔNp63α induces Id2 mRNA via induction of BMP signaling;Supplemental Figure S3. Schematic representation of BMP signaling status in 60 human breast cancer samples;Supplemental Figure S4. Stained negative controls for IHC/IF assays;Supplementary Figure S5. LDN193189 has anti-stem-like effects;Supplementary Figure S6. Hematoxylin and Eosin staining reveals similar tumor morphology in vehicle and LDN193189 treated groups;Supplementary Figure S7. LDN193189 treatment decreases tumor initiating capacity and increases tumor latency in limiting dilution assays.
ARTICLE ABSTRACT
Cranial irradiation can lead to long-lasting cognitive impairments in patients receiving radiotherapy for the treatment of malignant brain tumors. Recent studies have suggested inflammation as a major contributor to these deficits; we determined if the chemokine (C–C motif) receptor 2 (CCR2) was a mediator of cognitive impairments induced by irradiation. Two-month-old male Ccr2 knockout (−/−) and wild-type mice received 10 Gy cranial irradiation or sham-treatment. One month after irradiation, bromodeoxyuridine was injected intraperitoneally for seven consecutive days to label newly generated cells. At two months postirradiation, cognitive function was assessed by novel object recognition and Morris water maze. Our results show that CCR2 deficiency prevented hippocampus-dependent spatial learning and memory impairments induced by cranial irradiation. Hippocampal gene expression analysis showed that irradiation induced CCR2 ligands such as CCL8 and CCR2 deficiency reduced this induction. Irradiation reduced the number of adult-born neurons in both wild-type and Ccr2−/− mice, but the distribution pattern of the adult-born neurons through the granule cell layer was only altered in wild-type mice. Importantly, CCR2 deficiency normalized the fraction of pyramidal neurons expressing the plasticity-related immediate early gene Arc. These data offer new insight into the mechanism(s) of radiation-injury and suggest that CCR2 is a critical mediator of hippocampal neuronal dysfunction and hippocampal cognitive impairments after irradiation. Targeting CCR2 signaling could conceivably provide an effective approach to reduce or prevent the incidence and severity of this serious side effect of ionizing irradiation. Cancer Res; 73(3); 1201–10. ©2012 AACR.
