While the relative five-year survival rate for men with localized prostate cancer is nearly 100%, it plummets to 28% in the case of distant metastases. This underscores the importance of investigating those cells able to spread and form these metastases: circulating tumor cells (CTCs). Though rare and surrounded by other blood cells, CTCs can be isolated using the sensitive nanomaterial-based microfluidic technology the graphene oxide (GO) Chip. Whole blood samples from 54 prostate cancer patients were obtained with consent and processed on parallel chips for immunofluorescence and RNA analysis. All of the samples were analyzed for CTC enumeration, where captured cells were stained for cytokeratin 7/8 (CK), CD45, and DAPI. CTCs were identified as DAPI+/CK+/CD45- cells. CTCs were detected in all of the samples. Interestingly, 25 samples showed CTC clusters ranging from 2-10 CTCs per cluster. To explore the potential role of EGFR in metastatic progression and CTC survival, a subset of samples was also assayed for EGFR expression with 9/10 samples showing EGFR+ CTCs. RNA extracted from a parallel device was reverse transcribed to cDNA. The cDNA was analyzed via qPCR for expression levels of 96 genes of interest, including housekeeping genes; epithelial and mesenchymal genes; oncogenes and tumor suppressor genes; prostate specific genes; extracellular matrix and inflammatory genes; and others. The results show our ability to examine RNA from CTCs to examine the role of relevant pathways in the cells in transit. With analysis capabilities at both the RNA and protein levels, the GO Chip is an example of a clinically relevant microfluidic technology.

Citation Format: Molly Kozminsky, Kathleen C. Day, Guadalupe Lorenzatti Hiles, Shamileh Fouladdel, Ebrahim Azizi, Mark L. Day, Todd Morgan, Sunitha Nagrath. Analysis of prostate cancer circulating tumor cells at the mRNA and protein level using a microfluidic graphene oxide chip [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1731. doi:10.1158/1538-7445.AM2017-1731