UNLABELLED: Copper is an element required for cell proliferation and angiogenesis. Human prostate cancer xenografts with increased (64)Cu radioactivity were visualized previously by PET using (64)CuCl2 as a radiotracer ((64)CuCl2 PET). This study aimed to determine whether the increased tumor (64)Cu radioactivity was due to increased cellular uptake of (64)Cu mediated by human copper transporter 1 (hCtr1) or simply due to nonspecific binding of ionic (64)CuCl2 to tumor tissue. In addition, the functional role of hCtr1 in proliferation of prostate cancer cells and tumor growth was also assessed. METHODS: A lentiviral vector encoding short-hairpin RNA specific for hCtr1 (Lenti-hCtr1-shRNA) was constructed for RNA interference-mediated knockdown of hCtr1 expression in prostate cancer cells. The degree of hCtr1 knockdown was determined by Western blot, and the effect of hCtr1 knockdown on copper uptake and proliferation were examined in vitro by cellular (64)Cu uptake and cell proliferation assays. The effects of hCtr1 knockdown on tumor uptake of (64)Cu were determined by PET quantification and tissue radioactivity assay. The effects of hCtr1 knockdown on tumor growth were assessed by PET/CT and tumor size measurement with a caliper. RESULTS: RNA interference-mediated knockdown of hCtr1 was associated with the reduced cellular uptake of (64)Cu and the suppression of prostate cancer cell proliferation in vitro. At 24 h after intravenous injection of the tracer (64)CuCl2, the (64)Cu uptake by the tumors with knockdown of hCtr1 (4.02 ± 0.31 percentage injected dose per gram [%ID/g] in Lenti-hCtr1-shRNA-PC-3 and 2.30 ± 0.59 %ID/g in Lenti-hCtr1-shRNA-DU-145) was significantly lower than the (64)Cu uptake by the control tumors without knockdown of hCtr1 (7.21 ± 1.48 %ID/g in Lenti-SCR-shRNA-PC-3 and 5.57 ± 1.20 %ID/g in Lenti-SCR-shRNA-DU-145, P < 0.001) by PET quantification. Moreover, the volumes of prostate cancer xenograft tumors with knockdown of hCtr1 (179 ± 111 mm(3) for Lenti-hCtr1-shRNA-PC-3 or 39 ± 22 mm(3) for Lenti-hCtr1-shRNA-DU-145) were significantly smaller than those without knockdown of hCtr1 (536 ± 191 mm(3) for Lenti- SCR-shRNA-PC-3 or 208 ± 104 mm(3) for Lenti-SCR-shRNA-DU-145, P < 0.01). CONCLUSION: Overall, data indicated that hCtr1 is a promising theranostic target, which can be further developed for metabolic imaging of prostate cancer using (64)CuCl2 PET/CT and personalized cancer therapy targeting copper metabolism.
UNLABELLED: Copper is an element required for cell proliferation and angiogenesis. Humanprostate cancer xenografts with increased (64)Cu radioactivity were visualized previously by PET using (64)CuCl2 as a radiotracer ((64)CuCl2PET). This study aimed to determine whether the increased tumor (64)Cu radioactivity was due to increased cellular uptake of (64)Cu mediated by humancopper transporter 1 (hCtr1) or simply due to nonspecific binding of ionic (64)CuCl2 to tumor tissue. In addition, the functional role of hCtr1 in proliferation of prostate cancer cells and tumor growth was also assessed. METHODS: A lentiviral vector encoding short-hairpin RNA specific for hCtr1 (Lenti-hCtr1-shRNA) was constructed for RNA interference-mediated knockdown of hCtr1 expression in prostate cancer cells. The degree of hCtr1 knockdown was determined by Western blot, and the effect of hCtr1 knockdown on copper uptake and proliferation were examined in vitro by cellular (64)Cu uptake and cell proliferation assays. The effects of hCtr1 knockdown on tumor uptake of (64)Cu were determined by PET quantification and tissue radioactivity assay. The effects of hCtr1 knockdown on tumor growth were assessed by PET/CT and tumor size measurement with a caliper. RESULTS: RNA interference-mediated knockdown of hCtr1 was associated with the reduced cellular uptake of (64)Cu and the suppression of prostate cancer cell proliferation in vitro. At 24 h after intravenous injection of the tracer (64)CuCl2, the (64)Cu uptake by the tumors with knockdown of hCtr1 (4.02 ± 0.31 percentage injected dose per gram [%ID/g] in Lenti-hCtr1-shRNA-PC-3 and 2.30 ± 0.59 %ID/g in Lenti-hCtr1-shRNA-DU-145) was significantly lower than the (64)Cu uptake by the control tumors without knockdown of hCtr1 (7.21 ± 1.48 %ID/g in Lenti-SCR-shRNA-PC-3 and 5.57 ± 1.20 %ID/g in Lenti-SCR-shRNA-DU-145, P < 0.001) by PET quantification. Moreover, the volumes of prostate cancer xenograft tumors with knockdown of hCtr1 (179 ± 111 mm(3) for Lenti-hCtr1-shRNA-PC-3 or 39 ± 22 mm(3) for Lenti-hCtr1-shRNA-DU-145) were significantly smaller than those without knockdown of hCtr1 (536 ± 191 mm(3) for Lenti- SCR-shRNA-PC-3 or 208 ± 104 mm(3) for Lenti-SCR-shRNA-DU-145, P < 0.01). CONCLUSION: Overall, data indicated that hCtr1 is a promising theranostic target, which can be further developed for metabolic imaging of prostate cancer using (64)CuCl2PET/CT and personalized cancer therapy targeting copper metabolism.
Entities:
Keywords:
64Cu-chloride; PET/CT; copper metabolism; human copper transporter 1; prostate cancer
Authors: T R DeGrado; R E Coleman; S Wang; S W Baldwin; M D Orr; C N Robertson; T J Polascik; D T Price Journal: Cancer Res Date: 2001-01-01 Impact factor: 12.701
Authors: Catherine A Parr-Sturgess; Claire L Tinker; Claire A Hart; Michael D Brown; Noel W Clarke; Edward T Parkin Journal: Mol Cancer Res Date: 2012-08-30 Impact factor: 5.852
Authors: Jeffrey V Leyton; Tove Olafsen; Eric J Lepin; Scott Hahm; Karl B Bauer; Robert E Reiter; Anna M Wu Journal: Clin Cancer Res Date: 2008-11-15 Impact factor: 12.531
Authors: Michael F Berger; Michael S Lawrence; Francesca Demichelis; Yotam Drier; Kristian Cibulskis; Andrey Y Sivachenko; Andrea Sboner; Raquel Esgueva; Dorothee Pflueger; Carrie Sougnez; Robert Onofrio; Scott L Carter; Kyung Park; Lukas Habegger; Lauren Ambrogio; Timothy Fennell; Melissa Parkin; Gordon Saksena; Douglas Voet; Alex H Ramos; Trevor J Pugh; Jane Wilkinson; Sheila Fisher; Wendy Winckler; Scott Mahan; Kristin Ardlie; Jennifer Baldwin; Jonathan W Simons; Naoki Kitabayashi; Theresa Y MacDonald; Philip W Kantoff; Lynda Chin; Stacey B Gabriel; Mark B Gerstein; Todd R Golub; Matthew Meyerson; Ashutosh Tewari; Eric S Lander; Gad Getz; Mark A Rubin; Levi A Garraway Journal: Nature Date: 2011-02-10 Impact factor: 49.962
Authors: Subha Bakthavatsalam; Mark L Sleeper; Azim Dharani; Daniel J George; Tian Zhang; Katherine J Franz Journal: Angew Chem Int Ed Engl Date: 2018-08-29 Impact factor: 15.336
Authors: Eva J Ge; Ashley I Bush; Angela Casini; Paul A Cobine; Justin R Cross; Gina M DeNicola; Q Ping Dou; Katherine J Franz; Vishal M Gohil; Sanjeev Gupta; Stephen G Kaler; Svetlana Lutsenko; Vivek Mittal; Michael J Petris; Roman Polishchuk; Martina Ralle; Michael L Schilsky; Nicholas K Tonks; Linda T Vahdat; Linda Van Aelst; Dan Xi; Peng Yuan; Donita C Brady; Christopher J Chang Journal: Nat Rev Cancer Date: 2021-11-11 Impact factor: 69.800
Authors: Delphine Denoyer; Helen B Pearson; Sharnel A S Clatworthy; Zoe M Smith; Paul S Francis; Roxana M Llanos; Irene Volitakis; Wayne A Phillips; Peter M Meggyesy; Shashank Masaldan; Michael A Cater Journal: Oncotarget Date: 2016-06-14
Authors: M A Avila-Rodriguez; C Rios; J Carrasco-Hernandez; J C Manrique-Arias; R Martinez-Hernandez; F O García-Pérez; A R Jalilian; E Martinez-Rodriguez; M E Romero-Piña; A Diaz-Ruiz Journal: EJNMMI Res Date: 2017-12-12 Impact factor: 3.138