A novel dynamic matrix detachment model reveals a shift from apoptosis to necrosis in melanoma cells.

Anchorage-independence is a hallmark of invasive cancer. The setback of the classical poly-HEMA static matrix detachment (SMD) anoikis model is the absence of dynamic fluid circulation, resulting in cell aggregates. We addressed this problem by developing a novel 3D cell culture dynamic matrix detachment (DMD) model with a turbulent-free laminar flow, yielding a very low shear stress. In this study, we focused on melanoma cells where apoptosis was evaluated both via annexin V flow cytometry and caspase cleavage. The DMD model was superior to SMD in the induction of melanoma cell death and in revealing a shift from apoptosis to necrotic cell death, as evident by failure to activate caspase 9 and a decrease in annexin V stain. Combination of DMD with cisplatin could further accentuate necrotic cell death in cisplatin-resistant melanoma cells. Thus, the DMD model may be a useful matrix deprivation model to identify necrotic vs. apoptotic cell death pathways.