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281 Pages·2017·3.87 MB·English

ADHESIVE DYNAMICS SIMULATIONS OF TRANSPORT AND ADHESION OF
CIRCULATING TUMOR MICROEMBOLI

A Dissertation
Presented to the Faculty of the Graduate School
of Cornell University
In Partial Fulfillment of the Requirements for the Degree of
Doctor of Philosophy

by
Kevin Jamahl Anderson
January 2017
© 2017
Kevin Jamahl Anderson
ADHESIVE DYNAMICS SIMULATIONS OF TRANSPORT AND ADHESION OF
CIRCULATING TUMOR MICROEMBOLI

Kevin Jamahl Anderson, Ph. D.
Cornell University 2017

Cancer metastasis is a multistep process through which tumor cells detach from the
primary tumor and invade distant tissue sites. Studies have shown that tumor cells can
invade as multicellular aggregates or clusters known as circulating tumor microemboli
(CTM). CTM are potentially advantageous to individual cells in the survival,
proliferation, and establishment of micrometastatic lesions in distant organs, and the
presence of CTM in blood is seen as a marker of highly metastatic potential. In this
thesis, a novel adaptation of the Multiparticle Adhesive Dynamics (MAD) simulation
was developed to analyze the behavior of model CTM interacting with activated
endothelium. The model CTM, based on the morphology of Colo205 cell line samples,
consisted of doublet, triplet, and 4-mer aggregates in simple geometrical
conformations. These aggregates, coated with sialyl Lewisx, were applied to a series of
hydrodynamic and adhesive simulations in the presence of an E-selectin-coated plane
wall. Simulations consisting of the hydrodynamic component of the MAD simulation
analyzed the effects of model aggregate conformation and orientation on adhesive
binding potential. Larger CTM conformations with intermediate nonsphericities had
the highest adhesion potential. Adhesive interactions were also evaluated, and in vitro
rolling assays were used to establish the MAD simulation as a predictor of CTM
behavior in shear flow. Model CTM exhibited rolling and transient adhesion
interactions under physiological conditions. The distribution of adhesion interactions
observed was dependent on the aggregate size. Aggregates consisting of 3 cells
exhibited the most stable rolling, and rod-like 4-mer particles were unable to form
substantial tethers with the surface. The bond lengths and lifespans were measured,
and the distribution of lengths and lifespans correlated with the types of adhesion
interactions observed. The results of these simulations established this adaptation of
the MAD simulation as a method to evaluate metastatic efficiency.
BIOGRAPHICAL SKETCH
Kevin Jamahl Anderson was born to Tommy and Cheryl Anderson on March 24th,
1990, in Heidelberg, Germany. He attended the University of Alabama at
Birmingham, where he majored in Biomedical Engineering and was a member of the
Science and Technology Honors Program. While there he conducted research for Dr.
Yue Song, developing molecular dynamics simulations of poly-L-lysine interacting
with neutral and negatively charged lipid bilayers to study the membrane translocation
of cell penetrating peptides. In May 2011, Kevin earned a Bachelor of Science Degree
in Biomedical Engineering with honors in Science and Technology, and in the fall he
began his graduate studies in the Department of Biomedical Engineering at Cornell
University. Kevin worked in the laboratory of Dr. Michael R. King, where he
developed an adhesive dynamics simulation for the study of the transport and adhesion
of circulating tumor cell aggregates. During the course of his studies Kevin has
received the Sloan Foundation Fellowship, the Sage Diversity Fellowship, and the
National Science Foundation Graduate Research Fellowship. After leaving Cornell,
Kevin looks forward to continuing his career in biotechnology.

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To Mom, Dad, and Nana, who have supported me more times and in more ways than I
could ever write out on paper

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ACKNOWLEDGMENTS
First and foremost I would like to thank my advisor, Professor Michael R.
King. I know for some people, it was a daunting task to try to figure out which lab to
commit to for 5-6 years, but the choice could not have been easier for me. When I first
met him, I was inspired by the obvious passion he had for his work, and I felt right at
home with the people in the lab. Dr. King has continued to be a great source of
support, offering guidance and reassurance during the more challenging periods of my
studies. I’d also like to thank my thesis committee members, Dr. Jeffrey Varner and
Dr. Tracy Stokol, for their guidance and support. I really appreciate the advice and
additional perspective that they have given towards my work. I’d also like to thank the
department staff, particularly Belinda Floyd, who always worked out any problems or
handled any questions whenever I had to figure something out.
I’d also like to thank my mother, father, grandmother, and brother, who put up
with me skipping out on a lot of holidays. Unfortunately I was not close enough for
easy visits, but when we did get together it was always a fantastic reminder of the love
and support that helped me get to where I am today. I could not have done this without
you.
A special shoutout goes to Dr. Andrew Hughes, Dr. Yue Geng, and Adelaide
de Guillebon, and Dr. Weiwei Wang for their collaboration and extra help, in addition
to being great people to work with. And to the rest of the lab mates and managers over
the years, Dr. Jocelyn Marshall, Dr. Mike Mitchell, Thong Cao, Dr. Anne Rocheleau,
Jeffrey Mattison, Dr. Siddharth Chandasekaran, Korie Grayson, Nerymar Ortiz-Otero,
and Zeinab Mohamed, thanks for keeping the lab so simultaneously entertaining and
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intellectually stimulating. Outside of lab, I have met some fantastic people in Ithaca,
picked up a lot of fun new hobbies, and played on some great sports teams. Between
the random adventures out on the commons, and the nights just hanging out getting to
know each other, it has been a blast. And I’m glad that I was able to meet so many
people that I could really connect with.
And last, but definitely not least, I’d like to thank my girlfriend Shirley. She
has easily been the best thing to ever happen to me at Cornell. She has been a massive
support, particularly during my last two years, and I can’t thank her enough for all of
the love, laughs, and motivation she has given me.
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TABLE OF CONTENTS

ABSTRACT .................................................................................................................. iii
BIOGRAPHICAL SKETCH .......................................................................................... v
ACKNOWLEDGMENTS ............................................................................................ vii
LIST OF ABBREVIATIONS ..................................................................................... xiii
LIST OF FIGURES ...................................................................................................... xv
LIST OF TABLES ..................................................................................................... xvii
CHAPTER 1 – BACKGROUND & INTRODUCTION ............................................... 1
1.1 THE METASTATIC CASCADE .................................................................... 2
1.2 SELECTIN-MEDIATED ADHESION TO THE ENDOTHELIUM .............. 4
1.3 METASTASIS OF CIRCULATING TUMOR MICROEMBOLI .................. 9
1.4 MODELING CELL ADHESION .................................................................. 11
1.5 THE MULTIPARTICLE ADHESIVE DYNAMICS SIMULATION .......... 18
1.6 SUMMARY ................................................................................................... 28
CHAPTER 2 – ADAPTATION OF MULTIPARTICLE ADHESIVE DYNAMICS
SIMULATION TO MODEL CIRCULATING TUMOR MICROEMBOLI ............... 29
2.1 INTRODUCTION .............................................................................................. 30
2.2 METHODS ......................................................................................................... 33
2.2.1 CELL CULTURE ........................................................................................ 33
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2.2.2 CELL RECEPTOR DENSITY CONJUGATION VIA FLUORESCENTLY
CONJUGATED BEADS ...................................................................................... 33
2.2.3 ELECTRON MICROSCOPY OF CELL SURFACE ................................. 34
2.2.4 QUANTIFICATION OF COLO205 MORPHOLOGY .............................. 35
2.2.5 QUANTIFICATION OF E-SELECTIN LIGAND DENSITY ................... 36
2.2.6 GENERATION OF MULTIPARTICLE ADHESIVE DYNAMICS
SIMULATION MODEL PARTICLES ................................................................ 38
2.2.6 NUMERICAL IMPLEMENTATION ......................................................... 39
2.3 RESULTS ........................................................................................................... 46
2.3.1 ESTABLISHMENT OF MODEL CTM GEOMETRIES ........................... 46
2.3.2 QUANTIFICATION OF SIALYL LEWIS X DENSITY ON COLO205
CELLS .................................................................................................................. 49
2.3.3 MAD SIMULATION PARAMETERS ...................................................... 49
2.3.4 VALIDATION OF SIMULATION BEHAVIOR ....................................... 50
2.4 DISCUSSION ..................................................................................................... 55
2.5 CONCLUSIONS ................................................................................................ 56
CHAPTER 3 – HYDRODYNAMIC BEHAVIOR OF CIRCULATING TUMOR
MICROEMBOLI .......................................................................................................... 58
3.1 INTRODUCTION .............................................................................................. 59
3.2 METHODS ......................................................................................................... 62
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