Characterizing the micromechanical properties of myeloblasts from cancer patients with optical tweezers

Cell mechanics, in particular mechanical properties, has been suggested as a new biomarker indicative of cell state and phenotype. Acute myeloid leukemia (AML) is characterized by the abnormal increase of myeloblasts in blood and bone marrow. While AML has been extensively studied from the perspectives of biochemical and genetic aspects, little is known about its cellular biophysical properties. In this study, optical tweezer technology was used to examine the micromechanical properties of myeloblasts from bone marrow of AML patients at single cell level. The myeloblasts were separately analyzed according to their expression of CD34⁺, a marker of primitive hematopoietic cells. To extract the intrinsic properties from the relationship between the stretching force and the induced deformation, a theoretical approach was developed to model the mechanical responses of cells and further characterize their mechanical properties. The preliminary results show that the area compressibility modulus of CD34⁺ myeloblasts was significantly less than that of CD34^- cells, which indicate that micromechanical properties are unique features of myeloblasts and provide us with an insight into the cell mechanics of primitive AML cells.