Abstract 1457: An integrated microfluidic device for circulating tumor cell detection in pancreatic cancer patients.
Authors: Grafton Meggie MG , Jack Rhonda M. , Cieslak Robert , Rodriguez Danika , Sharma Somya , Simeone Diane M. , Nagrath Sunitha 
Published: August 2014

Pancreatic cancer has one of the highest mortality rates of all cancers. The mortality is associated with both resistance to therapeutics and late stage detection. Often by the time symptoms are presented the disease has advanced to an incurable state. Due to the aggressive nature of pancreatic cancer and the difficulty in obtaining biopsies, it has been challenging to examine the behavior and characteristics of pancreatic tumors over time. Recently, circulating tumor cells (CTCs) have been isolated from peripheral blood of cancer patients and correlated with survival and therapeutic response. CTCs can also be analyzed to provide insight into tumor genetics and metastatic capabilities. Since CTCs are present in early cancers, they have the potential to be used as an early screening marker of metastatic disease. Especially for pancreatic cancer, isolating CTCs would perhaps allow for detection prior to advanced disease states and aid in determining appropriate therapeutic treatments. We demonstrate an integrated microfluidic device to detect CTCs in pancreatic cancer patients. The three-part device which integrates an inertial pre-sorter, a passive mixer and a magnetic sorter can process 1ml of blood in less than 20min to achieve nearly 100% pure cancer cells at the outlet. High-throughput pre-sorting of CTCs from the diluted blood is achieved using the inertial sorter and further specificity and isolation of the CTCs is achieved through magnetic labeling and re-sorting. First diluted whole blood is run through the inertial spiral sorter at nearly 2ml/min.

The curvature of the spiral focuses and aligns cancer cells to the inner channel wall, thus making it possible to enrich the cancer cells. The outlet of the spiral is designed to collect the enriched CTC stream, which are then passed through a passive mixer with EpCAM-labeled superparamagnetic beads. Only the cancer cells will be labeled with the magnetic beads as leukocytes and erythrocytes do not express the epithelial markers that are targeted during the mixing process. The mixed and labeled sample is sorted by a continuous flow magnetic sorter, where the application of an external magnetic field deflects the magnetically labeled cancer cells to a single collection outlet. Once isolated, the highly pure CTC population can be counted, genetically profiled, immunostained, or cultured for further analysis. Cells were stained using

CK7/8, N-cadherin, CD45, and DAPI to assess epithelial and mesenchymal characteristics. Isolating pancreatic CTCs with both high sensitivity and high specificity can enable earlier cancer detection and downstream molecular analysis can identify key targets for pancreatic cancer treatment. Thereupon, the development of effective CTC isolation tools will improve patient prognosis and therapeutic treatment plans.

Citation Format: Meggie MG Grafton, Rhonda M. Jack, Robert Cieslak, Danika Rodriguez, Somya Sharma, Diane M. Simeone, Sunitha Nagrath. An integrated microfluidic device for circulating tumor cell detection in pancreatic cancer patients. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1457. doi:10.1158/1538-7445.AM2013-1457