Figure 5.

Proposed mechanism by which mTOR may contribute to radiosensitivity and DNA damage repair and thereby potential means in which inhibition of mTORC1 or mTORC2 may alter cell cycle arrest, DNA repair and cell survival following radiation. Pathologic pro-fibrotic lung fibroblasts may depend on both mTORC1 and mTORC2 for efficient cell cycle arrest and repair of DNA damage following radiation damage. In non-radiation induced lung damage, DNA damage may result from various chemical or other microinjuries that create a similar population of fibroblasts that depend on mTOR complexes for survival and proliferation. The bidirectional arrow indicates that AKT activates mTORC2 while mTORC2 can also positively impact PI3K/AKT signaling. T indicates the inhibition of the target molecule. The purple “bolt” indicates ionizing radiation.