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. Our research project focuses on study of prostate cancer cell
behaviors and its related mechanism in bone metastasis |
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Prostate cancer is the
second leading cause of malignancy-related mortality in males. Prostate
cancer cells spread to liver, lungs, and especially bone via the blood stream
and form secondary tumors in these organs. Bone
metastases are incurable and a major complication of prostate cancer
patients. Cancer cell motility towards increasing concentrations of
chemicals plays an important role in metastases. Our research focuses on
using an enabling microfluidic device to investigate prostate cancer cell
migration and its mechanism toward bone metastasis. |
Prostate cancer cellsPhoto taken by Dr. Lin. © 2008 |
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We appreciated the support by National Cancer Institute and
National Institutes of Health. |
Invasive prostate cancer cells © 2008 |
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Chemokine Gradient Formation in Microfluidic Devices to
Investigate Prostate Cancer Cell Migration |
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Smitha M. N. Rao, Cory Huggins,
Maham Rahimi, Kytai Nguyen, J.-C. Chiao PIE Proceeding 7270A. Dec. 2008. Metastasis
of cancer requires adhesion and migration of cells. The effect of chemokine
gradient on prostate cancer cells (PCC) is not well understood. A
poly-dimethylsiloxane (PDMS) microfluidic device that enables time-lapse
study of cell migration is presented. Photolithography and soft lithography
processes were used to fabricate the PDMS devices from SU-8 molds. The device
has two inlets, a cell reservoir and an outlet channel with a depth of 100µm.
The microfluidic device is configured to provide fluid mixing leading to a
gradient across the outlet channel. The inlets allow for introduction of
different chemokines at different concentrations and flow rates. The cell
migration in the presence of chemokine gradient and flow rate can thus be
monitored in a time-lapse fashion. The gradient formations at different flow
rates over different lengths of time have been analyzed. Flow rates of 2, 3,
6, 8, 10, 20 µl/min at 5-minute intervals for over an hour were monitored to
determine optimum flow rates and times required to produce desired gradient
profiles. Results suggest that gradients formed at lower flow rates have less
variation over time. Moreover, lower flow rates do not affect cell movement
making observation of cell migration towards gradients possible. Higher flow
rates have better gradient definition but cells tend to flow away with the
fluid. |
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The
Analysis of Surface Treatment of PDMS on Prostate Cancer and Smooth Muscle
Cells |
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Cory Huggins, Smitha M. N. Rao,
Kytai Nguyen, and J.-C. Chiao SPIE Proceeding 7269. Dec. 2008. The
analysis of cellular activity when exposed to polydimethylsiloxane (PDMS) is
necessary as this material has been used in various applications such as
tissue engineering and microfluidic devices for cellular studies due to the
polymer’s unique mechanical properties. In this particular study, we
investigated the effects of corona surface treated PDMS with different
cross-linker ratios on cellular activities by analyzing prostate cancer cell
(PC-3) and vascular smooth muscle cell (VSMC) adhesion and proliferation.
Both cell lines were subjected to a thin PDMS layer immediately after and 24
hours after corona treatment. The results indicated steady cell adhesion and
proliferation rates for both smooth muscle and prostate cancer cells when
seeded onto PDMS 24 hours after corona surface treatment, but significantly
less cell adhesion when seeded immediately after activation and controls
(PDMS without any treatment). These results would allow future PC-3 and VSMC
experiments to be performed in a PDMS environment that is not detrimental for
adhesion and proliferation. |
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Microfluidic Devices to Assess
Prostate Cancer Cell Migration |
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Smitha M. N. Rao, Cory Huggins, Victor Lin, Jer-Tsong
Hsieh, Ganesh V. Raj, Kytai T. Nguyen, J. –C. Chiao Presented at 2008 BMES, Annual Fall Meeting,
St. Louis. Oct. 1-4, 2008. A
microfluidic poly-dimethylsiloxane (PDMS) device that enables time-lapse
study of cell migration is presented. Photolithography and soft lithography
processes were used to fabricate the PDMS devices from SU-8 molds. The
two-step photolithography process produces devices with channel heights of
100 µm and 10 µm for cell/serum reservoirs and passage channels,
respectively. The reservoirs allow the introduction of growth
stimulating/inhibiting reagents or chemotractants at different concentrations
and the transparency of PDMS channels allows continuous monitoring of their
effect on cells over time.
Three different prototypes of the PDMS devices,
including 2-port, 2 x 2- port and 8–port ones, were tested. In each case,
there were reservoirs for both cells and serum connected by passage channels
in different configurations. To study cell migration, Prostate Cancer (PC-3)
cells were seeded for 24 hours in the cell reservoir before serum was
introduced in the serum reservoir. It was observed that the cells responded
to serum stimulation and migrated towards the stimuli through the passage
channels.
The PDMS microfluidic devices provide advantages
over the traditional Boyden chambers such as that they allow the introduction
of biochemical reagents of various concentrations simultaneously in a single
test and time-lapse assessment of cell migration. Thus the microfluidic
devices may provide a platform for cell biological analysis applications,
particularly in cancer research field. |
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Microfabricated
Gradient Generator: Investigation of Surface Treatment on Prostate Cancer
Cells |
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Cory Huggins, Smitha M. N. Rao, Maham Rahimi, Kytai Nguyen,
J.-C. Chiao Presented at 2008 BMES, Annual Fall Meeting, St. Louis.
Oct. 1-4, 2008. One of the major
complications with prostate cancer is the metastases of cancer cells. Certain
chemicals (chemokines) in the bloodstream create a gradient signaling cell to
move (taxis). It is essential to study the chemotaxis at the level of
cell-molecule interaction. Poly-dimethylsiloxane (PDMS) devices were
fabricated consisting of mixers and flow channels utilizing photolithography
and soft lithography. The gradient profiles across the channel were analyzed
using fluorescence dye via confocal microscopy. In addition, we investigated
the effect of treating PDMS with ionized oxygen plasma and BSA (bovine serum
albumin) on prostate cancer cell PC-3 attachment and cell viability. The
results for PDMS and oxygen plasma treated PDMS surfaces were summarized as
1) there was significantly more cell attachment for both types of surfaces
without BSA when compared with BSA. 2) In the analysis without BSA, the
oxygen plasma treated PDMS showed significantly less cell attachment in
comparison to PDMS. 3) When BSA was used, there was no significant difference
in cell attachment 4) There was no significant difference observed in cell
viability for each of the analyzed surfaces. The knowledge of the prostate
cancer cell attachment validates our device for further analysis of cell
migration. |
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Microfluidic Devices to Investigate Prostate Cancer Cell
Migration Toward Chemokine Gradients |
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S. M. N. Rao, M. Rahimi,
C. Huggins, H. Xu, G. Hajj Sleiman, K. Nguyen, J.C. Chiao Presented
at the BMES 2007, Biomedical Engineering Society Annual Fall Meeting, Sept.
26-29, 2007. Bone
metastases are major complications in prostate cancer patients. Adhesion and
migration of cells toward chemokine gradients is required for metastasis of
cancer cells. Various factors are believed to be involved with prostate
cancer cell (PCC) migration but little research has been conducted in the
effects of their gradients on PCC migration. In preliminary study, we used an
in vitro parallel flow system to investigate the adhesion of PCC on
micro-vascular endothelial cells (MECs). The PCC lines used are PC-3 and its
highly metastatic variant PC-3ML cells. PC-3ML cells adhered more on MECs compared
to PC-3 and cDNA micro-array analysis of MECs exposed to PC-3ML demonstrated
an induced expression of various genes including growth factors and
cytokines. The flow system is too wide to accommodate more than one channel
in the microscope field of view. Experiments with various gradients could
only be conducted one at a time. We utilized microfluidic platforms to
overcome these issues. The platform consisting of mixers and flow channels
were fabricated with poly(dimethylsiloxane) by photolithography/molding and
created gradient profiles across channels. We observed the flow of
fluorescent beads within channels as expected and will investigate the PCC
migration toward concentration gradients of various chemical factors. |
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Our team |
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Professor J.C. Chiao |
iMEMS, Electrical Engineering, UT-Arlington |
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Professor JT Hsieh |
UT-Southwestern Medical School, Urology Department,
Professor
Hsieh |
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Professor Victor Lin |
UT-Southwestern Medical School, Urology Department,
Professor Lin |
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Professor Kytai Nguyen |
Bioengineering, UT-Arlington, Professor Nguyen |
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Professor Genesh Raj |
UT-Southwestern Medical School, Urology Department,
Professor
Raj |
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Prostate cancer is a disease in
which cancer develops in the prostate, a gland in the male reproductive
system. It occurs when cells of the prostate mutate and begin to multiply out
of control…… About Prostate Cancer |
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Resources ·
National Institute
of Cancer ·
WebMD ·
CDC |
Prostate cancer cells.
Photo taken by Dr. Victor Lin. Copyright © 2008. |
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Created by J.C. Chiao |
