High-Affinity NIR-Fluorescent Inhibitors for Tumor Imaging via Carbonic Anhydrase IX

• Published in: Bioconjugate chemistry 2024-06, Vol.35 (6), p.790-803
• Main Authors: Žvinys, Gediminas, Petrosiute, Agne, Zakšauskas, Audrius, Zubrienė, Asta, Ščerbavičienė, Alvilė, Kalnina, Zane, Čapkauskaitė, Edita, Juozapaitienė, Vaida, Mickevičiu̅tė, Aurelija, Shubin, Kirill, Grincevičienė, Švitrigailė, Raišys, Steponas, Tars, Kaspars, Matulienė, Jurgita, Matulis, Daumantas
• Format: Article
• Language: English
• Subjects: Acidification; Affinity; Animals; Antigens, Neoplasm - analysis; Antigens, Neoplasm - metabolism; Biomarkers; Cancer; Cancer surgery; Carbonic anhydrase; Carbonic Anhydrase Inhibitors - chemistry; Carbonic Anhydrase Inhibitors - pharmacology; Carbonic Anhydrase Inhibitors - therapeutic use; Carbonic Anhydrase IX - antagonists & inhibitors; Carbonic Anhydrase IX - metabolism; Carbonic anhydrases; Carbonic Anhydrases - metabolism; Cell surface; Chemical compounds; Energy requirements; Fluorescent Dyes - chemistry; Fluorescent indicators; HeLa Cells; Humans; Hypoxia; Infrared Rays; Isoenzymes; Medical imaging; Metastases; Mice; Mice, Nude; Near infrared radiation; Neoplasms - diagnostic imaging; Optical Imaging - methods; Pharmacology; Radiation therapy; Solid tumors; Sulfonamides; Sulfonamides - chemistry; Surgery; Tumors; Xenotransplantation
• ISSN: 1043-1802; 1520-4812; 1520-4812
• DOI: 10.1021/acs.bioconjchem.4c00144

Tumor imaging and delivery of therapeutic agents may be achieved by designing high-affinity and high-selectivity compounds recognizing a tumor cell-expressing biomarker, such as carbonic anhydrase IX (CA IX). The CAIX, overexpressed in many hypoxic solid tumors, helps adjust to the energy requirements of the hypoxic environment, reduces intracellular acidification, and participates in the metastatic invasion of adjacent tissues. Here, we designed a series of sulfonamide compounds bearing CAIX-recognizing, high-affinity, and high-selectivity groups conjugated via a PEG linker to near-infrared (NIR) fluorescent probes used in the clinic for optically guided cancer surgery. We determined compound affinities for CAIX and other 11 catalytically active CA isozymes by the thermal shift assay and showed that the affinity K d value of CAIX was in the subnanomolar range, hundred to thousand-fold higher than those of other CA isozymes. Similar affinities were also observed for CAIX expressed on the cancer cell surface in live HeLa cell cultures, as determined by the competition assay. The NIR-fluorescent compounds showed excellent properties in visualizing CAIX-positive tumors but not CAIX-negative knockout tumors in a nude mice xenograft model. These compounds would therefore be helpful in optically guided cancer surgery and could potentially be developed for anticancer treatment by radiotherapy.