Microfluidic anoikis-chip for screening of cytostatic drugs for cander treatment

Background: Anoikis (“homeless”) refers to the process of detachment of cells from their matrix which causes cell death. For detailed drug-screening, microfluidics is ideal for studying the balance between cell survival and cell death, as cells can be studied in real-time at a single cell level in the presence of
different (dosages of) drugs.

Methods: MCF-7 breast cancer cells were incubated with a mixture of TNF-α and cycloheximide (CHX) or staurosporine (SSP) to induce apoptosis. The process of anoikis was measured conventional with a DELFIA assay and analyzed in real-time on chip at a single cell level using Annexin V and propidium iodide (PI).

Results: TNF-α/CHX and SSP both activated the apoptotic cascade, confirmed with light microscopy, and demonstrated an increase in time in the Annexin V-Europium fluorescent intensity in the adherent cell fraction and the fraction with floating cells and apoptotic bodies. For detailed cellular-based experiments, MCF-7 cells were successfully cultured in a microfluidic device. Continuous administration of 50μM SSP showed 100% positive for Annexin V and PI, though cells did not detach. Incubation over longer periods with TNF-α/CHX
demonstrated all the characteristics of the apoptotic process (shrinkage, fragmentation, membrane blebbing) though cells hardly detach. Differences in material (pyrex glass vs. polystyrene) and the way of administration (single vs.
continuous administration) might account for the effects seen and therefore further analysis is necessary.

Conclusions: Microfluidics has the potential for effective drugscreening and when using patient’s own cells obtained via biopsy optimal selection of cytotoxic treatment can be made.