MECHANICAL PROPERTIES OF BIO-FERROGRAPHY ISOLATED CANCEROUS CELLS STUDIED BY ATOMIC FORCE MICROSCOPY

Over the past few decades, circulating tumor cells (CTCs) have been studied as part of cancer research. This research focused mainly on CTCs enumeration and morphological analysis as a guiding prognosis in metastatic cancer patients. Here, we present a quantitative evaluation of cultured A431 epidermoid carcinoma cell line mechanical properties. The A431 cells were used as a model for epidermal growth factor receptor (EGFR) overexpressing target cells, simulating EGFR-overexpressing epithelial CTCs. These cells were isolated using the Bio-Ferrography (BF) method and analyzed using Atomic Force Microscopy (AFM). The different stages of the BF isolation protocol were analyzed, concerning their effect on the mechanical properties of the examined target cells.

The results show that the BF isolation method offers the ability to perform AFM mechanical analysis on the isolated cancerous cells. Furthermore, the BF isolation process showed no apparent effect on the analyzed elasticity of the captured cells, while several stages of the BF isolation protocol showed direct effects on the mechanical properties of the analyzed A431 cells. These changes in the mechanical properties include alternations in the analyzed Young`s modulus and the adhesion force between the AFM tip and the measured A431 cells. All of which can serve as a quantitative mechanical indicator which can be used for distinguishing between the target and background cells, without the use of traditional cell staining assay and subjective detection of an expert pathologist.

The output of this study may give essential information on cell mechanical property-disease state relationships, providing a new perspective for effective characterization, diagnosis, monitoring, and treatment.