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. 2022 Jan 28;4(1):e210070. doi: 10.1148/rycan.210070

Figure 5:

In vitro and in vivo studies demonstrate the ability of the analog of 18F fluorthanatrace (18F-FTT), 125I-KX1, to provide a measurement of poly (adenosine diphosphate–ribose) polymerase-1 (PARP-1) expression levels in tumor cells or a solid tumor. In vitro cell uptake study was performed using MEF PARP-1 KO−/−, MEF PAR2 KO −/−, and MEF wild-type cell. The cells were incubated with 125I-KX1, and the uptake was abrogated by the knockout of PARP-1 activity, shown in the top left. 125I-KX1 uptake was not decreased in the wild-type and the PARP-2 knockout cell line, showing the specificity of the 18F-FTT uptake to PARP-1 expression. PARP-1 activity was measured in three different cell lines, HCC1937 (BRCA mutation), MD-MBA-231 (triple negative), and MCF (ER positive). In vivo studies using xenografts implanted with three different cell lines revealed that the uptake of 125I-KX1, as shown in tumor to muscle ratio (TMR), paralleled the expression levels of PARP-1 in these cells. AU = arbitrary unit, BRCA = breast cancer gene, ER = estrogen receptor, KO = knockout, MEF = mouse embryonic fibroblast.

In vitro and in vivo studies demonstrate the ability of the analog of 18F fluorthanatrace (18F-FTT), 125I-KX1, to provide a measurement of poly (adenosine diphosphate–ribose) polymerase-1 (PARP-1) expression levels in tumor cells or a solid tumor. In vitro cell uptake study was performed using MEF PARP-1 KO−/−, MEF PAR2 KO −/−, and MEF wild-type cell. The cells were incubated with 125I-KX1, and the uptake was abrogated by the knockout of PARP-1 activity, shown in the top left. 125I-KX1 uptake was not decreased in the wild-type and the PARP-2 knockout cell line, showing the specificity of the 18F-FTT uptake to PARP-1 expression. PARP-1 activity was measured in three different cell lines, HCC1937 (BRCA mutation), MD-MBA-231 (triple negative), and MCF (ER positive). In vivo studies using xenografts implanted with three different cell lines revealed that the uptake of 125I-KX1, as shown in tumor to muscle ratio (TMR), paralleled the expression levels of PARP-1 in these cells. AU = arbitrary unit, BRCA = breast cancer gene, ER = estrogen receptor, KO = knockout, MEF = mouse embryonic fibroblast.