Single-Cell Biophysics: Measurement, Modulation, and Modeling

Single-Cell Biophysics: Measurement, Modulation, and Modeling

Poster Abstracts

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 Liu 1 , Aaron M. Horning 2 , Evan P. Perillo 1 , Cong Liu 1 , Mirae Kim 1 , Rohan Vasisht 1 , Hannah Horng 3 , Andrew K. Dunn 1 , Chun-Liang Chen 2 , Hsin-Chih Yeh 1 . 1 University of Texas at Austin, Austin, TX, USA, 2 University of Texas Health Science Center at San Antonio, San Antonio, TX, USA, 3 University 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 µm 2 /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.

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