Abstract 1685: Identification and characterization of EMT/MET signatures in circulating tumor cells isolated from patients with metastatic breast cancer using graphene oxide nano-chip

Proceedings: AACR 107th Annual Meeting 2016; April 16-20, 2016; New Orleans, LA Disseminated cancer cells identified in the circulatory system of cancer patients has implied to be the key drivers of tumor metastasis. These cells known as circulating tumor cells (CTCs) are emerging as an alternative to tissue biopsies to predict prognostic values, and to monitor evolving tumor heterogeneity through serial drug treatments. Recent technological advances have enabled the detection of CTCs in patient blood samples. However, the enumeration alone seems to be insufficient to obtain information that could benefit any clinical decisions. The limited sensitivity as well as the specificity of current approaches struggle from realizing the full promise of CTCs. We developed a sensitive microfluidic chip using functionalized graphene oxide (GO) nano-sheets to isolate CTCs with improved sensitivity and purity. Blood samples collected from metastatic breast cancer patients were processed through the chip within 6 hours of sampling and the CTCs were identified by the presence of cytokeratin with the absence of CD45 expression. EMT/MET signatures were characterized in the isolated CTCs to investigate its role by assessing gene expression profiles. Protein markers known to be up regulated during the EMT such as Vimentin and N-cadherin was examined along with HER2. mRNA expression of EMT markers were studied simultaneously using a multiplex TaqMan-based qRT-PCR method and compared to healthy controls. CTCs were successfully detected in >95% of patients examined in this study. Cell-to-cell intrapatient heteroheneity was observed in the isolated CTCs. Markers of EMT/MET phenotypes including Vimentin, EpCAM, HER2, CDH1, CDH2 and cytokeratin in the CTC samples were differentially expressed. These studies demonstrate the feasibility of utilizing the GO nano-chip in CTC isolation and characterization from metastatic breast cancer patients. Given the high sensitivity and the reproducibility to measure protein/gene expression levels of CTC biomarkers, we envision that our GO nano-chip may provide potential tool for real-time monitoring of cancer patients on clinical trials. Citation Format: Tae Hyun Kim, Hyeun Joong Yoon, Sunitha Nagrath. Identification and characterization of EMT/MET signatures in circulating tumor cells isolated from patients with metastatic breast cancer using graphene oxide nano-chip. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1685.