Fig. 3.

In vitro characterization of cTK266 reporter. (A) The ¹⁸F-FHBG uptake assay of cTK266-22B-Fluc cells treated with different doses of Dox for 24 h (n = 4). (B) Western blot analysis using HSV1-TK and β-actin antibodies for cTK266-22B-Fluc cell lysates. The cells were treated with 1, 2, and 5 μg/mL of Dox for 24 h. (C) The activity of caspase-3 determined by a caspase colorimetric assay kit (n = 3). (D) Ratiometric analysis of the relative FHBG uptake. The FHBG uptake was normalized with the bioluminescence signal from control and treated cells. Results were representative data collected from independent triplicate experiments.