Radioactive iodine-labeled, cyclic RGD-PEGylated gold nanoparticle (AuNP) probes are designed and synthesized for targeting cancer cells and imaging tumor sites. These iodine-125-labeled cRGD-PEG-AuNP probes are stable in various conditions including a range of pHs and high salt and temperature conditions. These probes can target selectively and be taken up by tumor cells via integrin αvβ3-receptor-mediated endocytosis with no cytotoxicity. The probes show a significant increase in the avidity of αvβ3 integrin compared to the corresponding free cRGD peptides. In-vivo SPECT/CT imaging results show that the iodine-125-labeled cRGD-PEG-AuNP probes can target the tumor site as soon as 10 min after injection, and also that cyclic RGD peptides are needed for efficient and long-term in-vivo monitoring. The results suggest that the probes circulate through the whole body, including renal filtration, and are excretable. These promising results show that radioactive-iodine-labeled gold nanoprobes have potential for highly specific and sensitive tumor imaging or for use as angiogenesis-targeted SPECT/CT imaging probes.
This tacrolimus population PK model will be a valuable tool in developing rational guidelines and provides a basis for individualized therapy after kidney transplantation in clinical settings of Korea.
A major drawback with current cancer therapy is the prevalence of unrequired dose-limiting toxicity to non-cancerous tissues and organs, which is further compounded by a limited ability to rapidly and easily monitor drug delivery, pharmacodynamics and therapeutic response. In this report, we describe the design and characterization of novel multifunctional “theranostic” nanoparticles (TNPs) for enzyme-specific drug activation at tumor sites and simultaneous in vivo magnetic resonance imaging (MRI) of drug delivery.
TNPs were synthesized by conjugation of FDA-approved iron oxide nanoparticles ferumoxytol to an MMP-activatable peptide conjugate of azademethylcolchicine (ICT), creating CLIO-ICTs (TNPs). Significant cell death was observed in TNP-treated MMP-14 positive MMTV-PyMT breast cancer cells in vitro, but not MMP-14 negative fibroblasts or cells treated with ferumoxytol alone. Intravenous administration of TNPs to MMTV-PyMT tumor-bearing mice and subsequent MRI demonstrated significant tumor selective accumulation of the TNP, an observation confirmed by histopathology. Treatment with CLIO-ICTs induced a significant antitumor effect and tumor necrosis, a response not observed with ferumoxytol. Furthermore, no toxicity or cell death was observed in normal tissues following treatment with CLIO-ICTs, ICT, or ferumoxytol.
Our findings demonstrate proof of concept for a new nanotemplate that integrates tumor specificity, drug delivery and in vivo imaging into a single TNP entity through attachment of enzyme-activated prodrugs onto magnetic nanoparticles. This novel approach holds the potential to significantly improve targeted cancer therapies, and ultimately enable personalized therapy regimens.
O-GlcNAc modification plays important roles in metabolic regulation of cellular status. Two homologs of O-GlcNAc transferase, SECRET AGENT (SEC) and SPINDLY (SPY), which have O-GlcNAc and O-fucosyl transferase activities, respectively, are essential in Arabidopsis but have largely unknown cellular targets. Here we show that AtACINUS is O-GlcNAcylated and O-fucosylated and mediates regulation of transcription, alternative splicing (AS), and developmental transitions. Knocking-out both AtACINUS and its distant paralog AtPININ causes severe growth defects including dwarfism, delayed seed germination and flowering, and abscisic acid (ABA) hypersensitivity. Transcriptomic and protein-DNA/RNA interaction analyses demonstrate that AtACINUS represses transcription of the flowering repressor FLC and mediates AS of ABH1 and HAB1, two negative regulators of ABA signaling. Proteomic analyses show AtACINUS’s O-GlcNAcylation, O-fucosylation, and association with splicing factors, chromatin remodelers, and transcriptional regulators. Some AtACINUS/AtPININ-dependent AS events are altered in the sec and spy mutants, demonstrating a function of O-glycosylation in regulating alternative RNA splicing.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.