Search

Background: The delivery of therapeutic nucleic acids, such as small interfering RNA (siRNA) and antisense oligonucleotides (ASO) into cells, is widely used in gene therapy. Gold nanoparticles (AuNPs) have proved to be effective in delivering silencing moieties with high efficacy. Moreover, AuNPs offer the possibility of spatial–temporal triggering of cell uptake through light irradiation due to their unique optical properties. Our study focuses on the use of AuNPs as improved vectorisation agents through mild photothermy triggered by visible light irradiation. This method promotes the transfection of oligonucleotides for gene silencing in 2D cells and more complex 3D spheroids. Results: Improving gene silencing strategies in 3D cell cultures is crucial since it provides more effective in vitro models to study cellular responses that closely resemble the in vivo tumour microenvironment. We demonstrate the potential of mild photothermy by effectively silencing the GFP gene in 2D cell cultures: HCT116 and MCF-7. Then we showed that mild photothermy could be effectively used for silencing the c-MYC oncogene transcript, which is greatly overexpressed in cancer cells. A decrease of 25% and 30% in c-MYC expression was observed in HCT116 2D cells and 7-day 3D spheroids, respectively. Conclusions: In summary, our findings offer a novel transfection approach for gene therapy applications in 2D and 3D tumour models. This approach is based on the use of mild photothermy mediated by AuNPs combined with visible laser irradiation that might pave the way for the spatial–temporal control of gene modulation. [ABSTRACT FROM AUTHOR]

Lung cancer (LC) is a leading cause of global cancer-related deaths, highlighting the development of innovative methods for biomarker detection improving the early diagnostics. microRNAs (miRs) alterations are known to be involved in the initiation and progression of human cancers and can act as biomarkers for diagnostics and treatment. Herein, we develop the application of molecular beacon (MB) technology to monitor miR-155-3p expression in human lung adenocarcinoma A549 cells without complementary DNA synthesis, amplification, or expensive reagents. Furthermore, we produced gold nanoparticles (AuNPs) for delivering antisense oligonucleotides into A549 cells to reduce miR-155-3p expression, which was subsequently detectable using the MB. The MB was designed and structural characterized by Förster Resonance Energy Transfer (FRET)-melting, Circular Dichroism (CD), Nuclear magnetic resonance (NMR), and fluorometric experiments, and then the hybridization conditions were optimized for an in vitro approach involving the detection of miR-155-3p in total RNA extracted from A549 cell line. The expression profile of miR-155-3p was obtained by RT-qPCR. The results demonstrated that MB was properly designed and showed efficacy in targeting miR-155-3p. Furthermore, a limit of detection down to nanomolar concentration was achieved and the specificity of the biosensor was proved. Moreover, the self-assembly of ASOs with AuNPs exhibited exceptional target specificity, effectively silencing miR-155-3p. Notably, compared to lipid-based transfection agent, AuNPs displayed superior silencing efficiency. We highlighted the ability of MB to detect changes in the target gene expression after gene silencing. Overall, this innovative approach represents a promising tool for detecting various biomarkers at the same time, with potential applications in clinical settings. [Display omitted] • A novel MB probe has been designed for single-step miR-155-3p detection. • The assay showed promising sensitivity with a detection limit of 0.66 nM. • Effective application of antisense oligonucleotides vectorized by AuNPs for miR-155-3p silencing. • MB detects post-gene silencing alterations, enabling miR-155-3p expression monitoring. • Molecular beacon-based assay is fast, simple, and inexpensive. [ABSTRACT FROM AUTHOR]

Gene therapy arises as a great promise for cancer therapeutics due to its potential to silence genes involved in tumor development. In fact, there are some pivotal gene drivers that suffer critical alterations leading to cell transformation and ultimately to tumor growth. In this vein, gene silencing has been proposed as an active tool to selectively silence these molecular triggers of cancer, thus improving treatment. However, naked nucleic acid (DNA/RNA) sequences are reported to have a short lifetime in the body, promptly degraded by circulating enzymes, which in turn speed up elimination and decrease the therapeutic potential of these drugs. The use of nanoparticles for the effective delivery of these silencers to the specific target locations has allowed researchers to overcome this issue. Particularly, gold nanoparticles (AuNPs) have been used as attractive vehicles for the target-specific delivery of gene-silencing moieties, alone or in combination with other drugs. We shall discuss current trends in AuNP-based delivery of gene-silencing tools, considering the promising road ahead without overlooking existing concerns for their translation to clinics. [ABSTRACT FROM AUTHOR]

Chronic myeloid leukemia (CML) is a rare malignant proliferative hematopoietic disease due to overexpression of a tyrosine kinase (TK) derived from the breakpoint cluster region (BCR)‐abelson tyrosine‐protein kinase 1 (ABL1) gene fusion. Imatinib (IM), blocks this tyrosine kinase, and is the first line TK inhibitor (TKI) used in CML treatment. In a high percentage of CML patients, a poor response with relapse and disease progression is associated to acquisition of resistance through different mechanisms, including dysregulation of c‐MYC proto‐oncogene. Gold nanoparticles (AuNPs) are shown to allow improved efficacy in gene silencing approaches toward cancer therapy. Herein, the silencing potential of AuNPs functionalized with antisense oligonucleotides selectively targeting the e14a2 BCR‐ABL1 or the c‐MYC, alone and combination is evaluated. It is demonstrated efficient silencing of gene expression that translated to a downregulation of protein levels in IM resistant CML cells (K562‐IM). This combination allowed for increased death of the malignant cells. These Au‐nanoconjugates may be useful to tackle IM‐resistance mechanisms, providing an additional tool for future combinatory schemes to fight CML with imatinib resistance. [ABSTRACT FROM AUTHOR]

The use of gold nanoparticles for effective gene silencing has demonstrated its potential as a tool for gene expression experiments and for the treatment of several diseases. Here, we used a gold nanobeacon designed to specifically silence the enhanced green fluorescence protein (EGFP) mRNA in embryos of a fli-EGFP transgenic zebrafish line, while simultaneously allowing the tracking and localization of the silencing events via the beacon's emission. Fluorescence imaging measurements demonstrated a decrease of the EGFP emission with a concomitant increase in the fluorescence of the Au-nanobeacon. Furthermore, microinjection of the Au-nanobeacon led to a negligible difference in mortality and malformations in comparison to the free oligonucleotide, indicating that this system is a biocompatible platform for the administration of gene silencing moieties. Together, these data illustrate the potential of Au-nanobeacons as tools for in vivo zebrafish gene modulation with low toxicity which may be used towards any gene of interest. [ABSTRACT FROM AUTHOR]

Antisense therapy is a powerful tool for post-transcriptional gene silencing suitable for down-regulating target genes associated to disease. Gold nanoparticles have been described as effective intracellular delivery vehicles for antisense oligonucleotides providing increased protection against nucleases and targeting capability via simple surface modification. We constructed an antisense gold-nanobeacon consisting of a stem-looped oligonucleotide double-labelled with 3′-Cy3 and 5′-Thiol-C6 and tested for the effective blocking of gene expression in colorectal cancer cells. Due to the beacon conformation, gene silencing was directly detected as fluorescence increases with hybridisation to target, which can be used to assess the level of silencing. Moreover, this system was extensively evaluated for the genotoxic, cytotoxic and proteomic effects of gold-nanobeacon exposure to cancer cells. The exposure was evaluated by two-dimensional protein electrophoresis followed by mass spectrometry to perform a proteomic profile and 3-(4,5-Dimethylthiazol-2-Yl)-2,5-Diphenyltetrazolium Bromide (MTT) assay, glutathione-S-transferase assay, micronucleus test and comet assay to assess the genotoxicity. This integrated toxicology evaluation showed that the proposed nanotheranostics strategy does not exhibit significant toxicity, which is extremely relevant when translating into in vivo systems. [ABSTRACT FROM AUTHOR]

Cancer remains a complex medical challenge and one of the leading causes of death worldwide. Nanomedicines have been proposed as innovative platforms to tackle these complex diseases, where the combination of several treatment strategies might enhance therapy success. Among these nanomedicines, nanoparticle mediated delivery of nucleic acids has been put forward as key instrument to modulate gene expression, be it targeted gene silencing, interference RNA mechanisms and/or gene edition. These novel delivery systems have strongly relied on nanoparticles and, in particular, gold nanoparticles (AuNPs) have paved the way for efficient delivery systems due to the possibility to fine-tune their size, shape and surface properties, coupled to the ease of functionalization with different biomolecules. Herein, we shall address the different molecular tools for modulation of expression of oncogenes and tumor suppressor genes and discuss the state-of-the-art of AuNP functionalization for nucleic acid delivery both in vitro and in vivo models. Furthermore, we shall highlight the clinical applications of these spherical AuNP based conjugates for gene delivery, current challenges, and future perspectives in nanomedicine. [ABSTRACT FROM AUTHOR]

The proposal of gene therapy to tackle cancer development has been instrumental for the development of novel approaches and strategies to fight this disease, but the efficacy of the proposed strategies has still fallen short of delivering the full potential of gene therapy in the clinic. Despite the plethora of gene modulation approaches, e.g., gene silencing, antisense therapy, RNA interference, gene and genome editing, finding a way to efficiently deliver these effectors to the desired cell and tissue has been a challenge. Nanomedicine has put forward several innovative platforms to overcome this obstacle. Most of these platforms rely on the application of nanoscale structures, with particular focus on nanoparticles. Herein, we review the current trends on the use of nanoparticles designed for cancer gene therapy, including inorganic, organic, or biological (e.g., exosomes) variants, in clinical development and their progress towards clinical applications. [ABSTRACT FROM AUTHOR]