Next Generation Sequencing Facilitates Quantitative Analysis of Differentially Expressed Genes in Radiated and Non-Radiated femurs

Mechanisms underlying radiation induced bone loss seen following clinical radiotherapy are largely unkown. In order to identify mechanisms underlying focal radiation induced bone loss, differentially expressed genes were assessed in radiated bones as compared to the contralateral leg from the same animal. Overall design: Four-month-old C57BL/6 mice received focal radiation as a single dose of 24Gy on day 0. Using X-Rad-SmART (Precision X-Ray (PXi), North Branford, Connecticut) an image-guided focal dose of 24Gy at 6.6Gy/minute was delivered to a 5mm region of the distal metaphyseal region of the right femur (radiated, R), while the left femur served as the contralateral control (non-radiated, NR). Bones were harvested on day 21 for RNA sequencing. This time point was selected because bone loss was observed at day 28 and we wanted to assess the events preceding bone loss.