Monitoring drug induced apoptosis and treatment sensitivity in non-small cell lung carcinoma using dielectrophoresis

Abstract

Non-invasive real time methods for characterizing biomolecular events that contribute towards apoptotic kinetics would be of significant importance in the field of cancer biology. Effective drug-induced apoptosis is an important factor for establishing the relationship between cancer genetics and treatment sensitivity. The objective of this study was to develop a non-invasive technique to characterize cancer cells that are undergoing drug-induced apoptosis. We used dielectrophoresis to determine apoptotic cells as early as 2 h post drug treatment as compared to 24 h with standard flow cytometry method using non-small cell lung cancer (NSCLC) adenocarcinoma cell line (HCC1833) as a study model. Our studies have shown significant differences in apoptotic cells by chromatin condensation, formation of apoptotic bodies and exposure of phosphatidylserine (PS) on the extracellular surface when the cells where treated with a potent Bcl-2 family inhibitor drug (ABT-263). Time lapse dielectrophoretic studies were performed over 24 h period after exposure to ABT-263 at clinically relevant concentrations. The dielectrophoretic studies were compared to Annexin-V FITC flow assay for the detection of PS in mid-stage apoptosis using flow cytometry. As a result of physical and biochemical changes, inherent dielectric properties of cells undergoing varying stages of apoptosis showed amplified changes in their cytoplasmic and membrane capacitance. In addition, zeta potential of these fixed isolated cells was measured to obtain direct correlation to biomolecular events.

Elucidating mechanisms of sunitinib resistance in renal cancer: an integrated pathological-molecular analysis

“…Based on previous literature data regarding TKI resistance we investigated COX2 and PAX8 immunostaining on resistance xenograft tumors [ 9 , 25 , 26 ]. We found slight COX2 expression increase is in resistant tumors (Figure 3A ), which is in line with previous reports showing that COX2 inhibition was able to potentiate sunitinib effect in RCC xenografts [ 9 ].…”

“…There was also a significant reduction of E-cadherin expression in resistant compared to sunitinib-sensitive tumors, indicating the development of an EMT phenotype (Figure 3B ). PAX8 is a cell lineage restricted transcription factors essential for embryonic kidney development [ 26 ]. It is used in as a marker of renal differentiation.…”

An Electrophysiological Approach to Measure Changes in the Membrane Surface Potential in Real Time

“…This can plausibly be the case during mitosis, apoptosis, T-cell activation, etc. (33)(34)(35). Likewise, changes in the surface charge density may also occur in parallel with changes that affect the polarizability of a membrane protein.…”

Breast cancer cell obatoclax response characterization using passivated‐electrode insulator‐based dielectrophoresis

“…Similarly, DEP has shown to detect drug response in cells (after 2 h of treatment) faster than other assessment methods such as flow cytometry which typical requires 24 h [20]. Along with this advantage, the OπDEP platform eliminates certain common drawbacks associated with other DEP platforms.…”

“…The 3DEP™ system was also used to complement flow cytometry assessments of drug-induced apoptosis progression in Jurkat T-cells [19]. Similar studies have been carried out using DEP-based techniques to study the drug-induced apoptosis in lung cancer cells [20]. These studies illustrate the value of DEP in drug response analysis using electrodes in direct contact with cell samples.…”