Abstract 2009: Gemcitabine-loaded EGFR aptamer for targeted therapy of lung cancer

Abstract

Abstract Lung cancer is the leading cause of cancer-related death in the world and non-small cell lung cancer (NSCLC) is the most common types of the lung cancer. Epidermal growth factor receptor (EGFR) is an attractive therapeutic target due to its high expression in NSCLC. Gemcitabine (Gem) has shown antitumor activity against many kinds of solid tumors, including NSCLC. Aptamers emerged as promising drug delivery vehicles because of their high binding affinity for the target molecules. The objective of this study was to develop the aptamer-drug conjugates using the EGFR-specific aptamer. EGFR aptamers selected by the SELEX process and gemcitabine was internally incorporated into the EGFR aptamer. In vitro binding affinity of EGFR and Gem-loaded EGFR aptamer was evaluated on EGFR-positive A549, H460, H1299 cell lines, as well as EGFR-negative H522 cells using confocal microscopy. To determine whether the Gem-loaded EGFR aptamer was effectively internalized, Z-stack images were acquired after 1 hr incubation of Cy5-conjugated EGFR aptamer at 37°C. The ex vivo biodistribution of Cy7-conjugated EGFR aptamer was investigated in NSCLC xenograft nude mice. To confirm the antiproliferative effects of Gem-loaded EGFR aptamer, the MTT cell proliferation assay was carried out in NSCLC cells. In the confocal image of EGFR-positive cells, Gem-loaded EGFR aptamers were selectively bound to the cell surface, while no aptamer binding was observed in H522 cells. Z-stack imaging showed that internalized Gem-loaded EGFR aptamer accumulated in EGFR-positive cells. The ex vivo biodistribution data showed that the Gem-loaded EGFR aptamer exhibited higher binding in EGFR-positive A549 tumors than scramble EGFR aptamer. A549 cells showed significant reduction in proliferation following treatment with Gem-loaded EGFR aptamer. Our results indicated that Gem-loaded EGFR aptamer has a potential therapeutic agent in EGFR-positive NSCLC therapy. Citation Format: Jun Young Park, Ye Lim Cho, Ju Ri Chae, Won Jun Kang. Gemcitabine-loaded EGFR aptamer for targeted therapy of lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2009.