Figure 6.

Pathways involved in apoptosis and RILI in tumors and normal lung tissue. M867, a selective caspase-3 inhibitor, sensitizes H460-Luc2 NSCLC cells to radiation-induced apoptosis. The effects of M867 are independent of AIF, and may be due to the induction of autophagy. RILI is a significant dose limiting complication of thoracic radiation for lung, breast, and esophageal cancer. Surprisingly, in normal tissue, M867 abrogates RILI, as evidenced by decreased phosphor-Smad2/3 and apoptosis of normal tissue cells.