Drug-induced changes in nanomechanics of mammalian cells as measured by AFM
Résumé
Comparative studies on the nanomechanics of normal and malignant cells of the same type are of great importance as they can reveal new information about, and help understanding mechanisms of malignant transformation. In this work, we investigate the morphology and the elastic properties of live cultured, normal human mammalian epithelial cells (HMEC) and breast carcinoma epithelial cells (MCF7), using atomic force microscopy (AFM). We describe the different behaviour of the two similar cell lines under curcumin treatment. Up to a six-hour long treatment leaves the MCF7 cells morphology non-affected, but the microtubules of HMEC cells disassemble and form a ring-like organization circumscribing the nuclear area. The observed morphological changes were correlated to modifications in cell's mechanics via elasticity force-volume measurements. Curcumin treatment modified elasticity of the HMEC cells increasing dramatically the cell's average Young's modulus. Contrariwise, a slight decrease in the Young's modulus value was noticed for the MCF7 cells, as they become softer due to the action of curcumin. This different response of the malignant and non-malignant cells under the same treatment might be of high importance in developing follow-up therapy against breast cancer. Moreover, we also explore the effectiveness of paclitaxel on MCF7 cells. Although paclitaxel is used widely in the treatment of breast cancer, not all tumors respond to this drug, and the characteristics that distinguish resistant tumors from sensitive ones are not well defined.