Ursolic Acid Promotes the Sensitization of rhTRAIL-resistant Triple-negative Breast Cancer.

Triple-negative breast cancer (TNBC) can be characterized as the deadliest breast cancer type considering the lack of efficacious therapeutics. Recombinant human tumor necrosis factor-related apoptosis-inducing ligand (rhTRAIL) is an encouraging anti-cancer therapeutic with the capacity to induce apoptosis in cancer cells but there are TNBCs less susceptible to rhTRAIL. The aim of this study was to assess the potential of the natural product ursolic acid (UA) to sensitize of rhTRAIL-resistant TNBCs.In order to evaluate apoptosis induction in rhTRAIL and UA-treated TNBC BT-20 and HCC1937 cells that are resistant to rhTRAIL, western blot analysis and Annexin V/PI assays were executed.

UA increased the expression of death receptors 4 and 5 and decreased the expression of c-FLIP_L transcriptionally sensitizing rhTRAIL-resistant TNBC cells to apoptosis induced by rhTRAIL.

UA is a possible potent sensitizer of rhTRAIL-resistant TNBCs to rhTRAIL-induced apoptosis.