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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 cells

Photo taken by Dr. Lin. © 2008

 

We appreciated the support by National Cancer Institute and National Institutes of Health.

 

Invasive prostate cancer cells © 2008

Chemokine Gradient Formation in Microfluidic Devices to Investigate Prostate Cancer Cell Migration

 

 

 

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.

 

The Analysis of Surface Treatment of PDMS on Prostate Cancer and Smooth Muscle Cells

 

 

 

 

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.

 

 Microfluidic Devices to Assess Prostate Cancer Cell Migration

 

 

 

 

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.

 

Microfabricated Gradient Generator: Investigation of Surface Treatment on Prostate Cancer Cells

 

 

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.

 

 Microfluidic Devices to Investigate Prostate Cancer Cell Migration Toward Chemokine Gradients

 

 

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.

 

 

Our team

Professor J.C. Chiao

iMEMS, Electrical Engineering, UT-Arlington

Professor JT Hsieh

UT-Southwestern Medical School, Urology Department, Professor Hsieh

Professor Victor Lin

UT-Southwestern Medical School, Urology Department, Professor Lin

Professor Kytai Nguyen

Bioengineering, UT-Arlington, Professor Nguyen

Professor Genesh Raj

UT-Southwestern Medical School, Urology Department, Professor Raj

 

What is Prostate Cancer?

 

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

 

Resources

 

·          National Institute of Cancer

·          Prostate Cancer Foundation

·          Mayo Clinic information

·          Medline Plus

·          WebMD

·          CDC

·          E-Medicine Health

·          Family Doctor

 

 

 

Prostate cancer cells. Photo taken by Dr. Victor Lin. Copyright © 2008.

 

 

Created by J.C. Chiao