1-Benzyl indazole derivative-based 18F-labeled PET radiotracer: Radiosynthesis and cell uptake study in cancer cells

Hypoxia-inducible factor-1 (HIF-1α) is a transcription factor activated in response to low oxygen level, and ishighly expressed in many solid tumors. Moreover, HIF-1α is a representative biomarker of hypoxia and alsohelps to maintain cell homeostasis under hypoxic condition. Most solid tumors show hypoxia, which inducespoor prognosis and resistance to conventional cancer therapies. Thus, early diagnosis of hypoxia with positronemission tomography (PET) radiotracer would be highly beneficial for management of malignant solid tumorswith effective cancer therapy. YC-1 is a most promising candidate among several HIF-1α inhibitors. As an effortto develop a hypoxia imaging tool as a PET radiotracer, we designed and synthesized [18F]DFYC based onpotent derivative of YC-1 and performed preliminary in vitro cell uptake study. [18F]DFYC showed a significantaccumulation in SKBR-3 cells among other cancer cells, proving as a good lead to develop a hypoxic solidtumor such as breast cancer.