Biomarker enzyme detection in tumor-bearing animals. TsonevaDesislava StritzkerJochen BedenkKristina ZhangQian FrentzenAlexa CappelloJoseph FischerUtz A. SzalayAladar 2015 <p>A549 tumor-bearing animals were injected with GLV-1h68, GLV-1h351 or GLV-1h408. Every week, serum was isolated and tested for biomarker enzyme activity. <b>A)</b> GLV-1h351 injected mice were analyzed for the presence of GLuc and GusA activity. <b>B)</b> Significantly less GusPlus activity in serum of GLV-1h408 injected mice was observed at all time points compared to GusA in GLV-1h68 and GLV-1h351 injected mice (upper chart). At the same time points, no differences were observed in <i>Renilla</i> luciferase activity in GLV-1h68 and GLV-1h408 injected mice (lower chart). Grey crosses indicate that GLV-1h351 injected mice were not imaged for <i>Renilla</i> luciferase activity. <b>C)</b> Analysis of biomarker enzymes and viral titers in tumors at the end of the experiment. The activities of GLuc and GusPlus are clearly underrepresented relative to viral titers compared to GusA. <b>D)</b> Individual mouse data from samples that were obtained at the end of the experiment (28 dpi).</p>