RT Journal Article SR Electronic T1 Expression of Multidrug Resistance Protein and Messenger RNA Correlate with 99mTc-MIBI Imaging in Patients with Lung Cancer JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 1476 OP 1483 VO 42 IS 10 A1 Zhou, Jinshan A1 Higashi, Kotaro A1 Ueda, Yoshimichi A1 Kodama, Yuko A1 Guo, Dachuan A1 Jisaki, Fumiko A1 Sakurai, Aya A1 Takegami, Tsutomu A1 Katsuda, Shogo A1 Yamamoto, Itaru YR 2001 UL http://jnm.snmjournals.org/content/42/10/1476.abstract AB In vitro studies have shown that 99mTc-sestamibi (MIBI) is a transport substrate for the P-glycoprotein (Pgp) pump and the multidrug resistance–associated protein (MRP) pump. However, whether MRP and lung resistance protein (LRP) affect tumor accumulation and efflux of 99mTc-MIBI in lung cancer is not known. In this study, we explored whether Pgp and the other pumps, MRP and LRP, affect tumor accumulation and efflux of 99mTc-MIBI in lung cancer. Methods: Thirty-four lung cancer patients who underwent surgery were examined. Before surgery, 99mTc-MIBI SPECT was performed 15 min and 180 min after injection, and early uptake, delayed uptake (L/Nd), and washout rate (L/Nwr) of 99mTc-MIBI were obtained. Pgp, MRP, and LRP expression were investigated by immunohistochemistry. The messenger RNA (mRNA) level of Pgp, MRP, and LRP was determined by real-time reverse-transcription polymerase chain reaction. The lung cancer 99mTc-MIBI images were correlated with protein and mRNA expression. Results: The mean L/Nd of the Pgp (−) group was significantly higher than that of the Pgp (++) group (P = 0.0324). The Pgp (++) group had a higher L/Nwr than did the Pgp (−) group (P = 0.0269). The mean L/Nd of the Pgp mRNA low-expression group was significantly higher than that of the Pgp mRNA high-expression group (P = 0.0127). The Pgp mRNA high-expression group had a higher L/Nwr than did the Pgp mRNA low-expression group (P = 0.0825). No appreciable correlation was found between the lung cancer 99mTc-MIBI images and the expression of MRP or LRP on the level of protein or mRNA. Conclusion: These data suggest that an increased level of Pgp expression correlates with a low accumulation on delayed scans and a high L/Nwr of 99mTc-MIBI in lung cancer. Neither MRP nor LRP expression on the level of either protein or mRNA correlated significantly with tumor accumulation or efflux of 99mTc-MIBI in lung cancer.