AFM-Detected Apoptotic Changes in Morphology and Biophysical Property Caused by Paclitaxel in Ishikawa and HeLa Cells

Abstract

The apoptosis of cancer cells is associated with changes in the important cell properties including morphology, surface roughness and stiffness. Therefore, the changes in morphology and biophysical properties can be a good way of evaluating the anticancer activity of a drug. This study examined the effect of paclitaxel on the properties of Ishikawa and HeLa cells using atomic force microscopy (AFM), and the relationship between the changes in morphology and the biophysical properties and apoptosis was discussed. The viability and proliferation of the cells were analyzed using the methylthiazol tetrazolium (MTT) method and a TUNEL assay to confirm cellular apoptosis due to a paclitaxel treatment. AFM observations clearly showed the apoptotic morphological and biophysical changes in Ishikawa and HeLa cells. After the paclitaxel treatment, the cell membrane was torn and holed, the surface roughness was increased, and the stiffness was decreased. These changes were observed more apparently after a 24 h treatment and in Ishikawa cells compared to HeLa cells. The MTT and TUNEL assays results revealed the Ishikawa cells to be more sensitive to paclitaxel than HeLa cells and definite apoptosis occurred after a 24 h treatment. These results showed good agreement with the AFM results. Therefore, research on the morphological and biophysical changes by AFM in cancer cells will help to evaluate the anticancer activities of the drugs.

Nanoscale Quantifying the Effects of Targeted Drug on Chemotherapy in Lymphoma Treatment Using Atomic Force Microscopy

“…The roughness of cell membrane has become a potential biomarker for indicating the cell's health state [33], [34]. Based on the AFM images obtained on the Raji cells stimulated by single agents and combined agents, the dynamical changes of cellular surface roughness were quantitatively measured.…”

“…When performing AFM imaging on living cells, the soft and dynamic nature of cell membrane makes that the tip can easily deform the cell surface [35] which introduces artificial errors if we directly evaluate cell roughness based on the images on living cells. Hence, current studies about measuring the cellular surface roughness by AFM are commonly performed on fixed cells [33], [34], [36]. However, chemical fixation inevitably alters the structures of cells.…”

“…In recent years, both cellular surface roughness [33], [34], [53], [54] and cellular mechanical properties [39], [40], [44], [47] have been proved to be novel label-free biomarkers for indicating the cell states. Here, AFM imaging and indenting was applied to quantitatively characterize the dynamic changes of cellular surface roughness and cellular mechanical properties during the combinational actions of chemotherapy drugs and targeted drug on the treatment of lymphoma cells Figs.…”

Capturing the elasticity and morphology of live fibroblast cell cultures during degradation with atomic force microscopy

“…Particularly, AFM was used to document that the morphology of cells is the first cell property that is affected by apoptosis (Hessler et al, 2005), as cell shrinkage was noted to take place before other biochemical changes, such as the loss of the mitochondrial membrane potential. More recently, AFM has been used to examine changes in cancer cell morphology and reduction in stiffness as they undergo apoptosis (Kim et al, 2012), and a protocol was developed to measure the elastic modulus of live cancer cells cultures (Zhou et al, 2012).…”

Nano-biomechanical investigation of living endothelial cells

“…Beside this, elasticity alterations can be caused by the collective action of myosin motor proteins (Schillers et al 2010). Oppositely, blocking microtubule disassembly induces cell stiffening (Kim et al 2012). As all cytoskeletal networks are in continuous and dynamic reorganization, cell stiffness is highly determined by their orchestrated cooperation.…”