In vitro 3-D Ovarian Cancer Model for Understanding Interactions with Supporting Mesenchymal Stem Cells and High Throughput Drug Screening

Ovarian cancers, the leading cause of gynecological cancer mortality worldwide, have a high mortality rate of ~55%. Ovarian cancer is often undetected (due to lack of specific symptoms) until it has disseminated within the pelvis and abdomen. At such late stages, ovarian cancer is difficult to treat and is often fatal. One of the main reasons for the fatality of the ovarian cancer is the lack of physiological 3-D models that can unravel the relationships between the ovarian cancer cells and their supporting cells that could guide the screening of drug candidates against ovarian cancers. The malignant epithelial ovarian cancer cells are found in 3-D spheroids within peritoneal fluid in vivo. It is apparent that 3-D in vitro spheroid models of the ovarian cancer need to be created, to better understand the spheroid biology and contribute to the identification of new treatment opportunities for metastatic ovarian cancers. In this project, we are working towards creating a 3-D in vitro model of ovarian cancer to probe the relationship between supporting mesenchymal stem cells and ovarian cancer cells, and how the synergy between interactions of these cells might increase the metastatic potential of ovarian cancers. We will use a variety of molecular biology approaches to discern the relationship between ovarian cancer cells and their supporting cells in a 3-D model of ovarian cancer. We will also screen drug candidates for their ability to treat metastatic ovarian cancers in this physiological model. The results from this project will have impact on the treatment strategies of ovarian cancers. Adult stem cells and animals are used in this laboratory.




Multiscale Biochemical and Mechanical Regulation of Cellular Phenotypes in Engineered Functional Microenvironments


By studying how the microenvironment influences cellular phenotypes we can elucidate fundamental biological mechanisms and conduct translational research to ultimately improve clinical results. Experiments in our lab analyze different variables such as cell-cell and cell-matrix interactions, matrix stiffness, and mechanical stimuli such as shear stress, compression and tension to help understand how these factors influence cancer cell behavior. We aim to understand how these variables impact things like tumor cell proliferation, apoptosis, migration, chemoresistance, differentiation, de-differentiation and tumor recurrence.

 



3D Models to Study Emergence of Chemoresistance and Tumor Relapse


Spheroids generated from patient derived cancer stem cells allow us to study the development of patient specific chemoresistance and tumor recurrence. Chemoresistance is measured by serially passaging the cancer stem cells in 3D hanging drop spheroids and analyzing the amount of cell death when treated with different drugs conditions. Part of this research is dedicated to identifying cancer cell markers that may indicate what chemotherapies may be effective and which ones may not.

 
 



Patient Derived Cancer Stem Cell Spheroids for Precision Ocology


By using cancer cells from patient biopsies, patient derived cancer stem cell spheroids are isolated and cultured in our lab. 3D hanging drop spheroids are tested in serial passage assays for personalized drug combinations that prove to be the most effective in causing cancer stem cell apoptosis. Validation of the in vitro assay takes place in vivo with mouse xenograft models to provide a physiologically accurate predictive model for identifying the most promising personalized treatment.

 



Mechanical Stimulation and Extracellular Matrix Manipulation in Ovarian Cancer

Cancer cells experience shear stress within the tumor microenvironment both within the primary tumor as well as post extraversion within the circulatory system, as in circulating tumor cells (CTC). This shear stress occurs from interstitial fluid flow and blood/lymph flow that is ever present within the microenvironments. This shear stress is increased as the disease progresses and this physiologic stimulus is often ignored when a variety of factors are investigated for influence on cancer progression. This work investigates the impact of shear stress stimulus on cancer cells cultured within a 3D microenvironment. Cells are encapsulated within a hydrogel which is then subjected to the desired shear stress through the gel construct. How the cells respond to shear stress stimulus either independently or while exposed to treatment is investigated for insight into cancer metastasis, invasion, mechanotransduction, chemoresistance, morphological changes, and proliferation.

Within the tumor microenvironment cells experience a variety of stimuli that are known to impact their fate and the progression of the disease. As the tumor expands proliferating cells must displace the surrounding tissue and stroma to continue the progression of the disease. This internal growth of the tumor causes the cells to experience a range of compression forces that subsequently influence the cell’s phenotype. The compression bioreactor was designed and constructed in house to investigate the effects of this compressive force in cells cultured within a 3D matrix. A membrane is deflected into the 3D culture hydrogel through the use of air pressure and the deflection is monitored via the change in resistivity of the membrane. This set up allows for the continuous monitoring of compressive strain and tunable compression wave forms desired for investigation by the user. How these compressive stimuli influence mechanotransduction, proliferation, cell morphology, gene expression, and drug resistance are currently under investigation within ovarian cancer cells.

 
 



3D Modeling of Tumor Heterogeneity


Using a 3D hanging drop model, our lab studies heterogeneous cell spheroids in order to better understand the roles that different cell types play in a cancer microenvironment. These patient specific tumoroids consist of macrophages, endothelial cells, vascular cells, and patient derived cancer stem cells in various combinations. This model allows for better understanding of how each cell type impacts cancer stem cell populations, chemoresistance and overall tumor progression which can lead to insight on potential translational therapeutic targets.

 



Biological Applications of Surfaces with Extreme Wettabilities


Surfaces with extreme wettabilities can be used to control the behavior of cells, bacteria and liquids. Paper substrates patterned with superomniphilic and superomniphobic areas are able to control where OVCAR3 cells settle and attach to the substrate. Anti-biofouling polyurethanes made with essential oils can prevent bacteria adhesion to maintain cleaner surfaces. Paper microfluidic devices to detect low concentrations of E. coli use a background of superomniphobic paper and a superomniphilic channel to lyse and determine the presence of E coli.

 
 




 








Wettability Engendered Templated Self-Assembly (WETS) of Nanoparticles for Drug Delivery


Nanoparticle drug delivery is a promising cancer therapy method, and we have developed a new nanoparticle synthesis method, WETS, that is able to produce spherical and non-spherical particles with a very high degree of control over size, shape, composition and morphology. The WETS method uses substrates with patterned wettability to build the polymer particles phase by phase using dip-coating. Due to the substrates having a omniphobic background all excess liquids recede from the substrate, leaving behind highly monodisperse particles in the exact shape of the omniphilic domain. Nanoparticle parameters are controlled independently with WETS, so the particles produced are used in a systematic study of the effects of size, shape, composition, drug loading and morphology on the biodistribution and effectiveness in halting tumor growth both in vitro and in vivo.