Preclinical Evaluation of Novel SGLT2-Targeted Near-Infrared Optical Imaging Agent for Early-Stage Pulmonary...

Lung cancer is increasingly diagnosed at early stages, but intraoperative localization of early lesions remains challenging. Intraoperative molecular imaging (IMI) aids in localization of tumors during surgery; however, no optical agents are targeted specifically for early-stage lesions. The sodium-glucose cotransporter 2 (SGLT2) has been implicated in early lung carcinogenesis. This study aimed to describe SGLT2 expression in early-stage lung adenocarcinoma (LUAD) and develop and validate a novel SGLT2-targeted near-infrared (NIR) contrast agent, GlucoGlo, for imaging LUAD.

SGLT2 expression was confirmed by immunohistochemistry (IHC) in human samples. GlucoGlo optical properties were characterized and compared to common NIR dyes. Sensitivity and specificity for SGLT2 were assessed using preclinical in vitro and in vivo mouse models.

On IHC, stage I LUAD displayed higher SGLT2 expression than stage II-III LUAD and normal lung tissue. GlucoGlo exhibited similar depth of penetration and resolution to FDA-approved contrast agents. SGLT2-expressing cell lines treated with GlucoGlo displayed higher fluorescence than the control cell line, confirming SGLT2-dependent uptake. Fluorescence increased with both incubation time and GlucoGlo concentration. Glucose and unconjugated GlucoGlo ligand competitively inhibited GlucoGlo in a dose-dependent manner, indicating high affinity and specificity. GlucoGlo selectively accumulated in SGLT2-expressing flank xenografts, with mean SBR of 2.23 and was inhibited by pretreatment with unconjugated GlucoGlo ligand.

These findings support the potential of GlucoGlo as a targeted IMI contrast agent for early-stage LUAD, and they provide a foundation for future in vivo studies and translational development.