Evasion of Apoptosis

The sixth hallmark of cancer is the ability to evade programmed cell death (apoptosis) which can lead to uncontrolled cell division in normal cell development. This inherent cell suicide program can serve as a safety net because cells with excessive DNA damage are eliminated through apoptosis. Cancer cells, on the other hand, are resistant to apoptosis and continue to grow and divide even after accumulation of mutations.

Caspase-3 Assay on Odyssey^® Infrared Imaging System

There are two major apoptosis signaling pathways: the death receptor (extrinsic) pathway and the mitochondrial (intrinsic) pathway. Under most circumstances, activation of either pathway leads to proteolytic cleavage and activation of caspases, a family of cysteine proteases that act as common death effector molecules. In-Cell Western™ Assay is a very helpful research tool for scientists who are quantifying cell signaling.

Below is an example of how Bond et al. (2008) used LI-COR Biosciences' Odyssey^® system for this purpose. S2 cells were treated with actinomycin D to induce apoptosis. Figure A (green) shows active caspase-3 in the wells. Figure B (red), shows f-actin staining of the same wells as a control for cell number normalization. The results are expressed quantitatively in real-time. The graph shows a time course of caspase-3 activation after treatment with actinomycin D.

Reprinted with permission from D. Bond, D.A. Primrose, and E. Foley. Biol. Proced. Online 10(1);20-28 (2008)