title: Development of a double-stranded siRNA labelling method by using99mTc and single photon emission computed tomography imaging.
abstract: In vivo biodistribution of small interfering RNAs (siRNAs) is important to develop them for medical use. Therefore, novel single photon emitter-labelled siRNA was prepared by using diethylenetriamine-N,N,N',N″,N″-pentaacetic acid (DTPA) and poly(A) polymerase, and subsequently, real-time analysis of siRNA trafficking was performed by using single photon emission computed tomography (SPECT). This study aimed at assessing the use of99mTc-radiolabelled siRNA targeting lacZ to detect lacZ expression in vivo. siRNA targeting lacZ was radiolabelled with99mTc by using the bifunctional chelator DTPA, and the labelling efficiency and specific activity were determined. The probe stability in RNaseA was assessed. SPECT imaging was performed in mice overexpressing the lacZ gene in the liver. Radiolabelled siRNA remained highly stable in RNaseA solution at 37 °C. In SPECT imaging, significant99mTc accumulation in the liver was observed in mice overexpressing the lacZ gene.99mTc-labelled lacZ siRNA shows β-galactosidase-specific accumulation and appears promising for the visualisation of lacZ expression in vivo. Our labelled siRNA should be deliverable to specific regions overexpressing the target gene.
authors: a Department of Pharmacy , National Cancer Centre Hospital East , Chiba , Japan.
authors: Daisuke
authors: D
authors: Kano
authors: b Department of Diagnostic Radiology , National Cancer Centre Hospital East , Chiba , Japan.|c Department of Radiology , Yokohama City University, School of Medicine, Yokohama , Japan.
authors: Yoshihiro
authors: Y
authors: Nakagami
authors: b Department of Diagnostic Radiology , National Cancer Centre Hospital East , Chiba , Japan.
authors: Hiroaki
authors: H
authors: Kurihara
authors: d Department of Radiation Oncology , National Cancer Centre Hospital East , Chiba , Japan.
authors: Shota
authors: S
authors: Hosokawa
authors: e Division of Functional Imaging, Research Centre for Innovative Oncology , National Cancer Centre Hospital East , Chiba , Japan.
authors: Sadamoto
authors: S
authors: Zenda
authors: b Department of Diagnostic Radiology , National Cancer Centre Hospital East , Chiba , Japan.
authors: Masahiko
authors: M
authors: Kusumoto
authors: e Division of Functional Imaging, Research Centre for Innovative Oncology , National Cancer Centre Hospital East , Chiba , Japan.
authors: Hirofumi
authors: H
authors: Fujii
authors: c Department of Radiology , Yokohama City University, School of Medicine, Yokohama , Japan.
authors: Tomohiro
authors: T
authors: Kaneta
authors: a Department of Pharmacy , National Cancer Centre Hospital East , Chiba , Japan.
authors: Shinichiro
authors: S
authors: Saito
authors: f Department of Clinical Pharmaceutics , Meiji Pharmaceutical University , Tokyo , Japan.
authors: Yoshihiro
authors: Y
authors: Uesawa
authors: f Department of Clinical Pharmaceutics , Meiji Pharmaceutical University , Tokyo , Japan.
authors: Hajime
authors: H
authors: Kagaya
mesh_terms: D000818:Animals; D015902:Gamma Cameras; D005786:Gene Expression Regulation; D018014:Gene Transfer Techniques; D057809:HEK293 Cells; D006801:Humans; D007763:Lac Operon; D051379:Mice; D057054:Molecular Imaging; D012330:RNA, Double-Stranded; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D034741:RNA, Small Interfering; D011877:Radionuclide Imaging; D013667:Technetium / Q000737:chemistry / Q000494:pharmacology*; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D012330:RNA, Double-Stranded; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D013667:Technetium
keywords: gene therapy; genomics; in vivo imaging; lacZ; nanotechnology; systemic delivery; vectors; β-galactosidase