Abstract B35: Isolation and characterization of circulating tumor cells (CTCs) from bladder cancer patients using a highly sensitive graphene oxide-based microfluidic device (GO chip)

Abstract

Abstract Introduction: A critical research topic in bladder cancer is determining the key regulators in the progression from noninvasive tumor to invasive and ultimately metastatic disease. Although patients with noninvasive bladder cancer can be treated through transurethral resection of bladder tumor and have a high survival rate (~95%), noninvasive bladder tumors recur in 50%-70% of cases. Of these, 10-15% of cases progress to invasive disease. Circulating tumor cells (CTCs) represent the transitional phase of progression between lymphovascular intravasation and distant metastases. Molecular profiling of these CTCs, beyond enumeration, can inform the molecules/pathways important in the invasion process, and potentially help unravel the mechanism of metastasis and provide new targets for therapy. Here we report the application of a highly sensitive graphene oxide-based microfluidic device to isolate and characterize CTCs from bladder cancer patients for the expression of markers implicated in an invasive phenotype. Methods: An anti-EpCAM and anti-EGFR biotinylated antibody cocktail was immobilized onto the graphene oxide chip (GO chip) to capture CTCs from whole blood. In patient samples, immunofluorescence staining for DAPI (nuclei), cytokeratin (cancer cell marker), EGFR and HER2 (markers of invasive phenotype), and CD45 (white blood cell marker) was used to enumerate CTCs. Cells with a DAPI+CK+CD45- phenotype were counted as CTCs. Blood samples from ten metastatic bladder cancer patients and two healthy controls were processed, stained, and analyzed. Results: CTCs were found in 10/10 (100%) patients, with an average of 17.70 cells/mL (s = 10.69 cells/mL). 9/10 patients exhibited CTCs that express EGFR, but only one patient had one CTC express HER2. Conclusion: The antibody-functionalized GO chips were able to successfully capture and enable characterization of CTCs from metastatic bladder cancer patients. EGFR potentially plays an important role in the vascular invasion process. Citation Format: Zeqi Niu, Molly A. Kozminsky, Kathleen C. Day, Phillip L. Palmbos, Mark L. Day, Sunitha Nagrath. Isolation and characterization of circulating tumor cells (CTCs) from bladder cancer patients using a highly sensitive graphene oxide-based microfluidic device (GO chip) [abstract]. In: Proceedings of the AACR Special Conference on Advances in Liquid Biopsies; Jan 13-16, 2020; Miami, FL. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(11_Suppl):Abstract nr B35.