Thiourea compound AW00178 sensitizes human H1299 lung carcinoma cells to TRAIL-mediated apoptosis.

The tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) triggers apoptosis in a wide variety of cancer cells. Recently, cancer cell resistance to TRAIL-mediated apoptosis has become a challenging issue in the development of TRAIL-based anti-cancer therapies. In this study, we found that 1-(5-chloro-2-methyl-phenyl)-3-[4-(5-trifluoromethyl-pyrazol-1-yl)-phenyl]-thiourea (AW00178) was able to sensitize TRAIL-resistant human lung cancer H1299 cells to TRAIL-mediated apoptosis. Treatment with AW00178, either alone or in combination with TRAIL, induced the expression of CHOP, a protein related to TRAIL sensitivity, and reduced the expression of survivin, an anti-apoptotic protein involved in TRAIL resistance. Additionally, AW00178, alone or in combination with TRAIL, induced the activation of c-Jun and inactivation of Akt. A pharmacologic inhibition study revealed that c-Jun activation and Akt inactivation were strongly related to CHOP induction and survivin down-regulation, respectively. In summary, these results suggested that AW00178 mediated sensitization to TRAIL-mediated apoptosis in H1299 cells by increasing sensitivity and decreasing resistance to TRAIL via the induction of c-Jun-dependent CHOP expression and the reduction of Akt-dependent survivin expression, respectively.