Single-Cell Biophysics: Measurement, Modulation, and Modeling

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Single-Cell Biophysics: Measurement, Modulation, and Modeling Poster Abstracts
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57-POS Board 29
Effect of Epithelial-Mesenchymal Transition on the Dynamics of Egfrs of Prostate Cancer
Cells Revealed by TSUNAMI 3D Tracking Microscope
Yen-Liang Liu1, Aaron M. Horning2, Evan P. Perillo1, Cong Liu1, Mirae Kim1 , Rohan Vasisht1,
Hannah Horng3 , Andrew K. Dunn1, Chun-Liang Chen2, Hsin-Chih Yeh1.
1University of Texas at Austin, Austin, TX, USA, 2University of Texas Health Science Center at
San Antonio, San Antonio, TX, USA, 3University of Maryland, College Park, MD, USA.
Dysregulated trafficking of receptor tyrosine kinases has been linked to oncogenesis. Here we
study the dynamics and mechanisms of epidermal growth factor receptor (EGFR) trafficking of
three epithelial prostate cancer cell with different degrees of metastatic potential: BPH1 (benign),
LNCaP (non-invasive malignant), and PC-3 (highly invasive malignant) using a 3D single-
particle tracking technique termed TSUNAMI (Tracking of Single particles Using Nonlinear
And Multiplexed Illumination). TSUNAMI is capable of tracking fluorescent nanoparticle-
tagged EGFR from 2 to 10 minutes and vertical tracking depth up to tens of microns. To analyze
the long 3D trajectories generated by the TSUNAMI microscope, a trajectory analysis algorithm
is developed to classify trajectories and extract the biophysical parameters, such as diffusivity,
inward movement, and the linear dimension of compartments that restrict receptors. These
parameters are used to quantify the metastatic potentials of prostate cancer cell lines. The
diffusion coefficients of EGFRs on PC-3 cells (0.010±0.014 µm 2/s) are around one-quarter of
those estimated from benign BPH1 cells (0.036±0.058 µm2/s) due to the denser cortical actin
networks on the apical side of PC-3 cells (revealed by 3D structured illumination microscope).
The invasive cells also exhibit longer (2.83±0.23 µm vs. 1.45±0.16 µm) and faster (0.021±0.016
µm/s vs. 0.005±0.002 µm/s) inward movement than non-invasive prostate cancer cells, which
implies that high endocytotic activity of metastatic cells. In addition, the biophysical properties
of EGFR trajectories are correlated to the mRNA expression levels of epithelial-mesenchymal
transition related genes. The results of single-cell gene analysis show that high expressions of
EGFR and Arp2/3 are correlated to the decrease of EGFR diffusivity, and the increase of
dynamins coheres with more active inward movement. This work demonstrates how EGFR
trajectory-derived biophysical parameters are potentially linked to metastasis.