Non-invasive detection of biomechanical and biochemical responses of human lung cells to short time chemotherapy exposure using AFM and confocal Raman spectroscopy

Cellular biomechanical properties including cell elasticity and cell adhesion are regarded as criteria to differentiate cancer cells and normal cells. In this study, the biomechanical properties including the Young's modulus and adhesion force of human lung adenocarcinoma epithelial cell line A549 and non-cancerous human primary small airway epithelial cells (SAECs) were measured by using atomic force microscopy (AFM). It was found that primary SAECs are stiffer and more adhesive than cancerous A549 cells. Upon treatment with anti-cancer drug doxorubicin (DOX) for a short time (4 hours), both biomechanical properties of A549 cells were found to be increased while those of SAECs were decreased, implying that DOX-induced response mechanisms are different between these two types of cells (cancerous vs. primary cells). Using confocal Raman spectroscopy, we measured the changes in (sub)cellular biochemical compositions of both cell types before and after DOX exposure. Our ultimate goal is to find out the potential relationship between the changes in biomechanics and biochemical compositions of lung epithelial cells in response to anti-cancer drugs.