There is a continues need to develop technologies to detect and characterize circulating tumor cells that can become aggressive, metastatic, and hard to treat. Among these aggressive CTC are cells known as Hypoxic cell populations that learn to adapt and survive to low oxygen levels. Our project aims to test the applicability of a novel technique to detect Hypoxic Circulating Tumor Cells (H-CTC) that can move from tumors to circulating blood invading other tissues and becoming resistant to chemotherapy and radiation. The proposed assay incorporates a set of patented organic compounds as markers of hypoxic circulating tumor cells (H-CTC) with potential clinical applications. To date, our research has generated preliminary in-vitro studies with a novel NBQ-TOM demonstrating its capacity as markers of hypoxic human cancer cells in vitro. Comparison with the control Pimonidazole demonstrated the advantages of novel NBQ- TOM compounds as hypoxic marker. To determine the capacity of NBQ-TOM as hypoxic fluorescent marker, samples of 15 ml human whole blood were spiked with hypoxic or normoxic colon cancer cells (COLO 205). Spiked hypoxic or normoxic cells are then enriched, recovered, and treated with NBQ-TOM (25uM) for 24 hours. After treatment generated fluorescence is measured with an OPTIMA BMG Fluorimeter to demonstrate the significant formation of a fluorescent metabolite on hypoxic tumor cells in contrast to cells treated under normoxic environment. Also, fluorescence microscopy analysis confirmed the stronger fluorescence generation at hypoxic conditions. These preliminary results strongly support the applicability of these molecules for an in-vitro detection assay of hypoxic CTC in circulating blood that can become metastatic. Additional sensitivity and specificity analysis needs to be implemented.

Citation Format: Beatriz Zayas, Karoline Rios, Osvaldo Cox. Detecting Hypoxic Circulating Tumor Cells (H-CTC) with a novel technique [abstract]. In: Proceedings of the AACR Special Conference: Liquid Biopsy: From Discovery to Clinical Implementation; 2024 Nov 13-16; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(21_Suppl):Abstract nr A047.