For Ac-225 labeling, the prepared DOTA-Pep-1L (CPC-scientific, San Jose, CA) was incubated with Ac-225 at 70°C for 50 minutes. The TLC plates were scanned on a BioScan Imaging Scanner. Cu-64 was purchased from Washington University in St. Louis. The custom peptide specific to IL13RA2 and a scrambled peptide were conjugated with NOTA by CPC scientific Inc (San Jose, CA). Both the peptides, Pep-1L and scrambled peptide-NOTA were radiolabeled with Cu-64 according to the previously reported methods [15].
Abstract
Glioblastoma (GBM) is the most aggressive primary malignant brain cancer that invariably results in a dismal prognosis. Chemotherapy and radiotherapy have not been completely effective as standard treatment options for patients due to recurrent disease. We and others have therefore developed molecular strategies to specifically target interleukin 13 receptor alpha 2 (IL13RA2), a GBM restricted receptor expressed abundantly on over 75% of GBM patients. In this work, we evaluated the potential of Pep-1L, a novel IL13RA2 targeted peptide, as a platform to deliver targeted lethal therapies to GBM. To demonstrate GBM-specificity, we radiolabeled Pep-1L with Copper-64 and performed in vitro cell binding studies, which demonstrated specific binding that was blocked by unlabeled Pep-1L. Furthermore, we demonstrated real-time GBM localization of [64Cu]Pep-1L to orthotopic GBMs using small animal PET imaging. Based on these targeting data, we performed an initial in vivo safety and therapeutic study using Pep-1L conjugated to Actinium-225, an alpha particle emitter that has been shown to potently and irreversibly kill targeted cells. We infused [225Ac]Pep-1L into orthotopic GBMs using convection-enhanced delivery and found no significant adverse events at injected doses. Furthermore, our initial data also demonstrated significantly greater overall, median and mean survival in treated mice when compared to those in control groups (p < 0.05). GBM tissue extracted from mice treated with [225Ac]Pep-1L showed double stranded DNA breaks, lower Ki67 expression and greater propidium iodide internalization, indicating anti-GBM therapeutic effects of [225Ac]Pep-1L. Based on our results, Pep-1L warrants further investigation as a potential targeted platform to deliver anti-cancer agents.
Sattiraju, A.; Solingapuram Sai, K. K.; Xuan, A.; Pandya, D. N.; Almaguel, F. G.; Wadas, T. J.; Herpai, D. M.; Debinski, W.; Mintz, A., Oncotarget 2017, 8 (26), 42997-43007.
SOCIAL MEDIA
Connect with us and stay updated by following our social media channels.
Latest Briefings from our Knowledge Center
Press Releases, Industry News, Articles, and Technical Content
Development of a selective, sensitive and robust oxyntomodulin dual monoclonal antibody immunoassay.
Umberger, T.S., Ming, W., Cox, J.M., Konrad, R.J. and Siegel, R.W. Bioanalysis 14, no. 18 (2022): 1229-1239.
- Lilly Research Laboratories, Eli Lilly & Company, Indianapolis, IN46285, USA
Human K2 EDTA and P800 plasma (500 μl) was spiked with proglucagon 33–61, 35–61 and 36–61 stable-isotope-labeled internal standard peptides (CPC Scientific, custom order) and diluted with I buffer (25 mmol/l Tris-HCl, 25 mmol/l HEPES, 300 mmol/l NaCl, 0.1% (v/v) octyl β-D-glucopyranoside, pH 7.5).
Line, J.E.; Seal, B.S.; Garrish, J.K. Appl. Microbiol. 2022, 2, 688–700.
Peptides were synthesized using standard solid-phase(Fmoc) chemistry with a peptide synthesizer (CPC Scientific Inc., Sunnyvale, CA 94089,USA, C12K-2β12 [..]
Kirk, N.S., Chen, Q., Wu, Y.G., Asante, A.L., Hu, H., Espinosa, J.F., Martínez-Olid, F., Margetts, M.B., Mohammed, F.A., Kiselyov, V.V. and Barrett, D.G. Nature Communications 13, no. 1 (2022): 5695.
- Eli Lilly and Company, Lilly Corporate Center, Indianapolis, IN 46285, USA.
Peptides were synthesized under contract by CPC Scientific, except for the N-terminally acetylated version of IM172N22 and the Glu3Arg, Glu3Ala, Glu4Arg, Glu4Ala, Glu5Ala, Glu5Arg, Trp6Ala, Gln8Ala, Ile9Ala, Glu10Ala, Glu10Arg and Tyr14Ala mutants of IM172N22
Coskun, T., Urva, S., Roell, W.C., Qu, H., Loghin, C., Moyers, J.S., O’Farrell, L.S., Briere, D.A., Sloop, K.W., Thomas, M.K. and Pirro, V. Cell Metabolism 34, no. 9 (2022): 1234-1247.
- Eli Lilly and Company, Lilly Corporate Center, Indianapolis, IN 46285, USA
Homologous and heterologous competition experiments were performed with non-radioactive peptide analogues[127I]-Tyr1-GIP(1-42) and [127]-Tyr10-GIP(1-42) to ensure quantification of the high-affinity binding site of the GIPR. Peptide analogues were generated using synthetic [127I]-Tyr amino acid building blocks (CPC Scientific).
Cecil, D.L., Curtis, B., Gad, E., Gormley, M., Timms, A.E., Corulli, L., Bos, R., Damle, R.N., Sepulveda, M.A. and Disis, M.L. Scientific Reports 12, no. 1 (2022): 13618.
- Cancer Vaccine Institute, University of Washington, 850 Republican Street, Brotman Bld., 2nd Floor, Box 358050, Seattle, WA 98195-8050, USA.
- Janssen Research and Development LLC, Spring House, PA, USA.
- Janssen Vaccines and Prevention, Leiden, The Netherlands.
The peptides were constructed and purified by high-performance liquid chromatography (> 90% pure; CPC Scientific).
Zonari, A., Brace, L.E., Alencar-Silva, T., Porto, W.F., Foyt, D., Guiang, M., Cruz, E.A.O., Franco, O.L., Oliveira, C.R., Boroni, M. and Carvalho, J.L. Toxicology Reports 9 (2022): 1632-1638.
Peptide 14 (ETAKHWLKGI) (Sup. Fig. 1) was purchased from CPC Scientific Inc. (USA), which synthesized the peptide by solid phase (Fmoc) on a Rink amide resin, with > 95% purity, in the form of acetate salt.
CPC Scientific Inc., a leading global peptide CRDMO (Contract Research, Development, and Manufacturing Organization) has invested in a new peptide API (Active Pharmaceutical Ingredient) manufacturing site, bringing many new jobs to Rocklin, California. The 41,000 sq ft facility located at 3880 Atherton Rd, Rocklin, CA 95765 will be utilized to manufacture clinical to commercial grade peptide products for increased manufacturing capacity and will diversify CPC Scientific’s supply chain.
CPC Scientific is entering an exciting period of growth and innovation for peptide and oligonucleotide therapeutic development and manufacturing, and we will continue to provide therapeutic APIs to pharmaceutical and biotech companies around the world. We are very pleased to partner with the City of Rocklin, California to bring manufacturing and Life-Science jobs to local American workers,” said Shawn Lee, PhD, CEO.
Ikeda, Z., Kakegawa, K., Kikuchi, F., Itono, S., Oki, H., Yashiro, H., Hiyoshi, H., Tsuchimori, K., Hamagami, K., Watanabe, M. and Sasaki, M. Journal of Medicinal Chemistry 65, no. 12 (2022): 8456-8477.
- Research, Takeda Pharmaceutical Company Limited, 26-1, Muraokahigashi 2-chome, Fujisawa, Kanagawa 251-8555, Japan
Subsequently, 5FAM–Abu–Gly–Asp–Asp–Asp–Lys–Ile–Val–Gly–Gly–Lys(CPQ2)–Lys–Lys–NH2 (purity: 97.2%, CPC Scientific, Inc.) was diluted with an assay buffer to prepare a 2.1 μM substrate solution.
The transferred energy from a fluorescent donor is converted into molecular vibrations if the acceptor is a non-fluorescent dye (quencher). When the FRET is terminated (by separating donor and acceptor), an increase of donor fluorescence can be detected. The design and synthesis work at CPC for FRET and TR-FRET peptide substrates include modification of sequences, selection of donor/quencher pairs, improvement of FRET substrate solubility and quenching efficiency.