BH3 profiling and a toolkit of BH3-mimetic drugs predict anti-apoptotic dependence of cancer cells

Background: Anti-apoptotic BCL-2 family members antagonise apoptosis by sequestering their pro-apoptotic counterparts. The balance between the different BCL-2 family members forms the basis of BH3 profiling, a peptide-based technique used to predict chemosensitivity of cancer cells. Recent identification of cell-permeable, selective inhibitors of BCL-2, BCL-X-L and MCL-1, further facilitates the determination of the BCL-2 family dependency of cancer cells. Methods: We use BH3 profiling in combination with cell death analyses using a chemical inhibitor toolkit to assess chemosensitivity of cancer cells. Results: Both BH3 profiling and the inhibitor toolkit effectively predict chemosensitivity of cells addicted to a single anti-apoptotic protein but a combination of both techniques is more instructive when cell survival depends on more than one anti-apoptotic protein. Conclusions: The inhibitor toolkit provides a rapid, inexpensive and simple means to assess the chemosensitivity of tumour cells and in conjunction with BH3 profiling offers much potential in personalising cancer therapy.