title: TSPO 18 kDa (PBR) Targeted Photosensitizers for Cancer Imaging (PET) and PDT.
abstract: Translocator protein (TSPO) 18 kDa overexpression has been observed in a large variety of human cancers, especially breast cancers. PK 11195, an isoquinoline analogue, is one of the ligands of highest TSPO binding affinity. Due to the long biological half life of our photosensitizers, there is a need to label them with a long lived radioisotope, for example I-124. Our objectives are to find translocator protein targeted photosensitizers for both tumor imaging (PET) and photodynamic therapy (PDT). I-PK 11195 is conjugated with the tumor avid photosensitizer HPPH. We find that those two tumor avid components complement each other and make the conjugate molecule even more tumor avid; compared to the photosensitizer itself, the conjugate is found to show improved PDT efficacy. It is concluded that I-PK 11195 can be a good vehicle to deliver radionuclide and photosensitizer to TSPO overexpressed tumor regions. Such conjugates could be useful for both tumor imaging (PET) and PDT.
authors.affiliation: PDT Center, Roswell Park Cancer Institute, Buffalo, New York 14263, United States ; Department of Nuclear Medicine, State University of New York, Buffalo, New York 14214, United States.
authors.forename: Yihui
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Department of Nuclear Medicine, State University of New York, Buffalo, New York 14214, United States.
authors.forename: Munawwar
authors.initials: M
authors.lastname: Sajjad
authors.affiliation: PDT Center, Roswell Park Cancer Institute, Buffalo, New York 14263, United States.
authors.forename: Yanfang
authors.initials: Y
authors.lastname: Wang
authors.affiliation: PDT Center, Roswell Park Cancer Institute, Buffalo, New York 14263, United States.
authors.forename: Carrie
authors.initials: C
authors.lastname: Batt
authors.affiliation: Department of Nuclear Medicine, State University of New York, Buffalo, New York 14214, United States.
authors.forename: Hani A
authors.initials: HA
authors.lastname: Nabi
authors.affiliation: PDT Center, Roswell Park Cancer Institute, Buffalo, New York 14263, United States.
authors.forename: Ravindra K
authors.initials: RK
authors.lastname: Pandey
keywords: PK 11195; Photodynamic therapy (PDT); cancer target specific; peripheral benzodiazepine receptor (PBR); positron emission tomography (PET); translocator protein (TSPO)