Project Title: Microfluidic cell sorter for breast cancer circulating tumor cells

Project Duration: May 22 – July 28, 2017 (10 weeks), 40 hours per week.

Project Mentors –

Primary Faculty Mentor (Name, Affiliation, website and Email/Phone):

Leidong Mao, PhD, UGA College of Engineering, mao@uga.edu, 706-542-1871, http://magnet.engr.uga.edu

Secondary Faculty Mentor (Name, Affiliation, website and Email/Phone):

Melissa Davis, PhD, UGA Department of Genetics, mbdavis@uga.edu, 706-542-5014, http://research.franklin.uga.edu/davislab

Graduate Student/PostDoc mentors (Name, Affiliation and Email/Phone):

Wujun Zhao, UGA College of Engineering, zhaowj@uga.edu, 706-542-1482

Project Description: Circulating Tumor Cells (CTCs) are detached from primary solid tumors and carried through the vasculature to potentially seed distant site metastases in vital organs – the main cause of death by cancer that originates in the breast. For aggressive subtypes of breast cancer, such as Triple Negative Breast Cancer (TNBC), with no effective targeted treatment, early detection and characterization of CTCs could be an important step in precise diagnosis. Formative/iterative assessments of CTCs throughout the treatment process could also inform more effective disease management of TNBC. CTCs represent the composition of the primary tumor, even the heterogeneity of tumors, such as the six sub-classes of TNBC. While CTCs initially express the same markers as the primary tumor epithelial cells, once in circulation the CTCs undergo morphological and gene expression changes, including the well-described Epithelial to Mesenchymal Transitions (EMT). The subsequent CTC changes determine what distant site will become the new niche for a metastatic tumor. And so, characterizing all CTC populations in a patient can allow prognosis of undetected metastasis and/or recurrence risk. One major limitation of CTCs in breast cancer research has been the limited availability of isolated CTCs for investigations due in part to the small patient blood volumes that are allowable for research, which typically yield low numbers of CTCs (1-100 cells in 1 mL of blood). Additionally, inherent bias of label/marker-based methodology in current standard methods of CTC capture limits the dynamic range of applications to known/expected CTC types. These markers may or may not be present on some CTCs, depending on the subtype and aggressiveness of the tumors, which varies among individuals. These issues render clinical development of CTC technology extremely difficult, with low reproducibility or reliability among patient groups.

REU Student Role and Responsibility: Our goal is to further develop label-free technologies that exploit the size difference between blood component cells and CTCs in blood and permit heterogeneity studies to characterize the entire repertoire of CTCs. The student will work with a graduate student to further optimize a magnetic microfluidic system that can be used to process breast cancer specimens at a CTC recovery ratio of over 90% with a cell-processing throughput of over 10^9 cells/hour. Specifically, the student will 1) survey the size profile of multiple breast cancer cell lines; 2) simulate using COMSOL/Matlab and demonstrate the feasibility of enriching CTCs from WBCs based on their size differences; 3) fabricate the microfluidic system and process the spiked samples, as well as patient samples; 4) learn cell culture, CTC characterization techniques including Pap staining, immunofluorescent staining, immunohistochemistry (IHC); 5) characterize the metrics of the microfluidic sorter.

Expected Outcome for REU student: The student is expected to contribute and co-author journal and conference papers. He/she will present preliminary results at 2017 BMES annual meeting in Phoenix, Arizona (Oct 11-14).