Contribution of cell-surface interaction and cytoskeletal
component, F-actin, to the mechanical phenotypes of epithelial cells.
(a) Schematic of experimental
conditions used to measure the effects of cell-surface interaction on the
wCDI. While poly-D-lysine (PDL) increases the positive charges on the
channel wall for increased cell-surface interaction, bovine serum albumin
(BSA) minimizes cellular adhesion to the channel wall. The control for all
experiments was bare PDMS. (b) The
difference in wCDI measured when MCF-7 cells transit a bare PDMS
contraction channel (control) and a PDL-coated channel or a BSA-coated
channel (n=99 for all cases) under
various fluidic conditions. The difference in wCDI becomes smaller with
greater Pinlet.
Within each box, the central red line corresponds to the median, and the
edges of the box to 25% and 75% of the population. (c) Fluorescence images of MCF-7 and MCF-10A cells after
treatment with Latrunculin A (LatA, 5 μg mL−1,
1 h) or Latrunculin B (LatB, 5 μg mL−1, 1 h).
Cell nuclei and F-actin are stained with 4ʹ,6-diamidino-2-phenylindole
(DAPI, blue) and rhodamine Phalloidin (red), respectively. Scale bar
corresponds to 20 μm. (d) Transverse
deformation (δdeform) of untreated, LatA-, and
LatB-treated MCF7 and MCF10A cells (n=99). Statistical differences were determined by a paired
t-test. (e) wCDI distribution of MCF-7 (n=99, Ctrl vs LatA: P=0.0074, Ctrl vs LatB: P=0.0253) and MCF-10A cells (n=99, Ctrl vs LatA: P=4.8940e-7, Ctrl vs LatB: P=0.9758), in which cells were either untreated or treated
with LatA or LatB. Statistical differences were determined by a paired
t-test. Within each box, the central
red line corresponds to the median, and the edges of the box to 25% and
75% of the population. (f) The proportion
of untreated and treated MCF-7 and MCF-10A cells screened that recovered
instantaneously (ΔTr~0), required 40 ms or less
(0<ΔTr⩽40 ms), or did not recover within
window time measured (ΔTr>40 ms). The
statistical differences between the proportions of recovery types of
untreated and treated cells were evaluated by a Chi-square test. For all
graphs, *, **, ***, and **** indicate P⩽0.05, P⩽0.01, P⩽0.001, and P⩽0.0001, respectively.