Work

Optimizing Glioma Detection Using an EGFR‐Targeted Fluorescent Affibody

Year: 2018

Type: article

Abstract: Since many types of cancers overexpressEGFR, this surface receptor has been used as a target for therapy or diagnosis of malignant disease. Uptake kinetics ofEGFR‐targeted fluorescent Affibody (ABY‐029) were studied with a view toward optimizing efficacy of tumor detection in a glioma as a function of both delivered dose and concurrent administration of unlabeled cetuximab (anEGFRantagonist). U251 glioma cells were inoculated in brain of nude rats, and the fluorescence from each brain was analyzed after the administration ofABY‐029. Although cetuximab was able to systematically blockABY‐029 binding toEGFRin a dose‐dependent manner in cell culture, no influence on the tumor‐to‐normal brain contrast was seen when unlabeled cetuximab was administered prior toABY‐029.Ex vivoimaging ofABY‐029 fluorescence showed increasing values of the tumor‐to‐normal brain ratio with an increasing injected dose. A saturation value was obtained at a dose of 245 μg kg−1which represents a 10‐fold increase over a “microdose” value. According toFDA, the microdose of protein products is considered ≤30 nanomoles due to its difference in molecular weight as compared to synthetic drugs. This observation indicates that glioma detection will be optimal if theABY‐029 dose exceeds the “microdose” value.

Source: Photochemistry and Photobiology

DOI: 10.1111/php.13003