Comparison of ~(99m)Tc-Tetrofosmin and ~(99m)Tc-Sestamibi Uptake in Glioma Cell Lines: The Role of P-Glycoprotein Expression

摘要

~(99m)Tc-Tetrofosmin (~(99m)Tc-TF) and ~(99m)Tc-Sestamibi (~(99m)Tc-MIBI) are SPECT tracers that have been used for brain tumor imaging. Tumors multidrug resistance phenotype, namely, P-glycoprotein (p-gp), and the multidrug resistance related proteins (MRPs) expression have been suggested to influence both tracers' uptake. In the present study we set out to compare ~(99m)Tc-TF and ~(99m)Tc-MIBI uptake in high-grade glioma cell lines and to investigate the influence of gliomas p-gp expression on both tracers' uptake. We used four glioma cell lines (U251MG, A172, U87MG, and T98G). The expression of p-gp protein was evaluated by flow cytometry. Twenty muCi (7.4-105 Bq) of ~(99m)Tc-TF and ~(99m)Tc-MIBI were used. The radioactivity in the cellular lysate was measured with a dose calibrator. P-gp was significantly expressed only in the U251MG cell line (P < 0.001). In all gliomas cell lines (U251MG, U87MG, A172, and T98G) the ~(99m)Tc-TF uptake was significantly higher than ~(99m)Tc-sestamibi. The U251MG cell line, in which significant p-gp expression was documented, exhibited the strongest uptake difference. ~(99m)Tc-TF uptake was higher than ~(99m)Tc-MIBI in all studied high-grade glioma cell lines. Thus, ~(99m)Tc-TF may be superior to ~(99m)Tc-MIBI for glioma imaging in vivo.