Targeted siRNA Nanoparticles for Mammary Carcinoma Therapy

Osteopontin: A Key Multifaceted Regulator in Tumor Progression and Immunomodulation

The tumor microenvironment (TME) is composed of various cellular components such as tumor cells, stromal cells including fibroblasts, adipocytes, mast cells, lymphatic vascular cells and infiltrating immune cells, macrophages, dendritic cells and lymphocytes. The intricate interplay between these cells influences tumor growth, metastasis and therapy failure. Significant advancements in breast cancer therapy have resulted in a substantial decrease in mortality. However, existing cancer treatments frequently result in toxicity and nonspecific side effects. Therefore, improving targeted drug delivery and increasing the efficacy of drugs is crucial for enhancing treatment outcome and reducing the burden of toxicity. In this review, we have provided an overview of how tumor and stroma-derived osteopontin (OPN) plays a key role in regulating the oncogenic potential of various cancers including breast. Next, we dissected the signaling network by which OPN regulates tumor progression through interaction with selective integrins and CD44 receptors. This review addresses the latest advancements in the roles of splice variants of OPN in cancer progression and OPN-mediated tumor-stromal interaction, EMT, CSC enhancement, immunomodulation, metastasis, chemoresistance and metabolic reprogramming, and further suggests that OPN might be a potential therapeutic target and prognostic biomarker for the evolving landscape of cancer management.

Transitional Insight into the RNA-Based Oligonucleotides in Cancer Treatment

Conventional cancer therapies with chemodrugs suffer from various disadvantages, such as irreversible side effects on the skin, heart, liver, and nerves with even fatal consequences. RNA-based therapeutic is a novel technology which offers great potential as non-toxic, non-infectious, and well-tolerable platform. Herein, we introduce different RNA-based platforms with a special focus on siRNA, miRNA, and mRNA applications in cancer treatment in order to better understand the details of their therapeutic effects. Of note, the co-delivery of RNAs with other distinct RNA or drugs has provided safe, efficient, and novel treatment modalities for cancer treatment.

Drug repurposing for the treatment of COVID-19: Targeting nafamostat to the lungs by a liposomal delivery system

Despite tremendous global efforts since the beginning of the COVID-19 pandemic, still only a limited number of prophylactic and therapeutic options are available. Although vaccination is the most effective measure in preventing morbidity and mortality, there is a need for safe and effective post-infection treatment medication. In this study, we explored a pipeline of 21 potential candidates, examined in the Calu-3 cell line for their antiviral efficacy, for drug repurposing. Ralimetinib and nafamostat, clinically used drugs, have emerged as attractive candidates. Due to the inherent limitations of the selected drugs, we formulated targeted liposomes suitable for both systemic and intranasal administration. Non-targeted and targeted nafamostat liposomes (LipNaf) decorated with an Apolipoprotein B peptide (ApoB-P) as a specific lung-targeting ligand were successfully developed. The developed liposomal formulations of nafamostat were found to possess favorable physicochemical properties including nano size (119-147 nm), long-term stability of the normally rapidly degrading compound in aqueous solution, negligible leakage from the liposomes upon storage, and a neutral surface charge with low polydispersity index (PDI). Both nafamostat and ralimetinib liposomes showed good cellular uptake and lack of cytotoxicity, and non-targeted LipNaf demonstrated enhanced accumulation in the lungs following intranasal (IN) administration in non-infected mice. LipNaf retained its anti-SARS-CoV 2 activity in Calu 3 cells with only a modest decrease, exhibiting complete inhibition at concentrations >100 nM. IN, but not intraperitoneal (IP) treatment with targeted LipNaf resulted in a trend to reduced viral load in the lungs of K18-hACE2 mice compared to targeted empty Lip. Nevertheless, upon removal of outlier data, a statistically significant 1.9-fold reduction in viral load was achieved. This observation further highlights the importance of a targeted delivery into the respiratory tract. In summary, we were able to demonstrate a proof-of-concept of drug repurposing by liposomal formulations with anti-SARS-CoV-2 activity. The biodistribution and bioactivity studies with LipNaf suggest an IN or inhalation route of administration for optimal therapeutic efficacy.

Targeted silencing of the MCL-1 gene using multi-layered dendrimer-based nanoconstructs achieves efficient tumor regression in xenografted mice models

The setback in the practical clinical use of RNA interference (RNAi)-based cancer treatment stems from the lack of targeted small interfering RNA (siRNA) delivery. Here, we show that luteinizing hormone-releasing hormone(LHRH) analog-tethered multi-layered polyamidoamine (PAMAM) nanoconstructs silence the anti-apoptotic MCL-1 gene in LHRH receptor overexpressing human breast (MCF-7) and prostate cancer (LNCaP) cells with 70.91 % and 74.10 % efficiency, respectively. These results were confirmed by RT-PCR. The Acridine orange/Ethidium bromide (AO/EB) dual staining revealed that the silencing of MCL-1 induced apoptosis in both the cell lines. In vivo tumor regression studies performed using MCF-7 and LNCaP xenografted severe combined immunodeficiency(SCID) mice demonstrated highly improved tumor regression in groups treated with targeted nanoconstructs complexed with MCL-1 siRNA (T + siMCL-1) compared to the other treatment groups. The quantitative RT-PCR results of tumor tissues demonstrated significant MCL-1 gene silencing, i.e., 73.76 % and 92.63 % in breast and prostate tumors, respectively, after T + siMCL-1 treatment. Reduction in MCL-1 protein expression as assessed by immunohistochemistry further confirmed these results. Furthermore, the caspase 3/7 assay demonstrated apoptosis in the MCL-1 silenced tissues. The study strongly suggests that targeted delivery of siRNAs using multi-layered dendrimer nanostructures could be an effective therapy for LHRH overexpressing cancers.

Nanoparticles of VAV1 siRNA combined with LL37 peptide for the treatment of pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is among the leading causes of cancer-related death, and it is highly resistant to therapy owing to its unique extracellular matrix. VAV1 protein, overexpressed in several cancer diseases including pancreatic cancer (PC), increases tumor proliferation and enhances metastases formation, which are associated with decreased survival. We hypothesized that an additive anti-tumor effect could be obtained by co-encapsulating in PLGA nanoparticles (NPs), the negatively charged siRNA against VAV1 (siVAV1) with the positively charged anti-tumor LL37 peptide, as a counter-ion. Several types of NPs were formulated and were characterized for their physicochemical properties, cellular internalization, and bioactivity in vitro. NPs' biodistribution, toxicity, and bioactivity were examined in a mice PDAC model. An optimal siVAV1 formulation (siVAV1-LL37 NPs) was characterized with desirable physicochemical properties in terms of nano-size, low polydispersity index (PDI), neutral surface charge, high siVAV1 encapsulation efficiency, spherical shape, and long-term shelf-life stability. Cell assays demonstrated rapid engulfment by PC cells, a specific and significant dose-dependent proliferation inhibition, as well as knockdown of VAV1 mRNA levels and migration inhibition in VAV1⁺ cells. Treatment with siVAV1-LL37 NPs in the mice PDAC model revealed marked accumulation of NPs in the liver and in the tumor, resulting in an increased survival rate following suppression of tumor growth and metastases, mediated via the knockdown of both VAV1 mRNA and protein levels. This proof-of-concept study validates our hypothesis of an additive effect in the treatment of PC facilitated by co-encapsulating siVAV1 in NPs with LL37 serving a dual role as a counter ion as well as an anti-tumor agent.

Cell-directed aptamer therapeutic targeting for cancers including those within the central nervous system

Osteopontin (OPN) is produced by tumor cells as well as by myeloid cells and is enriched in the tumor microenvironment (TME) of many cancers. Given the roles of OPN in tumor progression and immune suppression, we hypothesized that targeting OPN with aptamers that have high affinity and specificity could be a promising therapeutic strategy. Bi-specific aptamers targeting ligands for cellular internalization were conjugated to siRNAs to suppress OPN were created, and therapeutic leads were selected based on target engagement and in vivo activity. Aptamers as carriers for siRNA approaches were created including a cancer targeting nucleolin aptamer Ncl-OPN siRNA and a myeloid targeting CpG oligodeoxynucleotide (ODN)-OPN siRNA conjugate. These aptamers were selected as therapeutic leads based on 70–90% OPN inhibition in cancer (GL261, 344SQ, 4T1B2b) and myeloid (DC2.4) cells relative to scramble controls. In established immune competent 344SQ lung cancer and 4T1B2b breast cancer models, these aptamers, including in combination, demonstrate therapeutic activity by inhibiting tumor growth. The Ncl-OPN siRNA aptamer demonstrated efficacy in an immune competent orthotopic glioma model administered systemically secondary to the ability of the aptamer to access the glioma TME. Therapeutic activity was demonstrated using both aptamers in a breast cancer brain metastasis model. Targeted inhibition of OPN in tumor cells and myeloid cells using bifunctional aptamers that are internalized by specific cell types and suppress OPN expression once internalized may have clinical potential in cancer treatment.

Liposomal siRNA Formulations for the Treatment of Herpes Simplex Virus-1: In Vitro Characterization of Physicochemical Properties and Activity, and In Vivo Biodistribution and Toxicity Studies

Herpes simplex virus-1 (HSV-1) is highly contagious, and there is a need for a therapeutic means to eradicate it. We have identified an siRNA (siHSV) that knocks down gene expression of the infected cell protein 0 (ICP0), which is important in the regulation of HSV infection. The selected siHSV was encapsulated in liposomes to overcome its poor stability, increase cell permeability, and prolonging siRNA circulation time. Several siRNAs against ICP0 have been designed and identified. We examined the role of various parameters, including formulation technique, lipids composition, and ratio. An optimal liposomal siHSV formulation (LipDOPE-siHSV) was characterized with desirable physiochemical properties, in terms of nano-size, low polydispersity index (PDI), neutral surface charge, high siHSV loading, spherical shape, high stability in physiologic conditions in vitro, and long-term shelf-life stability (>1 year, 4 °C). The liposomes exhibited profound internalization by human keratinocytes, no cytotoxicity in cell cultures, no detrimental effect on mice liver enzymes, and a gradual endo-lysosomal escape. Mice biodistribution studies in intact mice revealed accumulation, mainly in visceral organs but also in the trigeminal ganglion. The therapeutic potential of siHSV liposomes was demonstrated by significant antiviral activity both in the plaque reduction assay and in the 3D epidermis model, and the mechanism of action was validated by the reduction of ICP0 expression levels.

A brief review of the essential role of nanovehicles for improving the therapeutic efficacy of pharmacological agents against tumours

Cancer is the leading cause of death globally. There are several differences between cancer cells and normal cells. From all the therapies, chemotherapy is the most prominent therapy to treat cancer. However, the conventional drug delivery that is used to deliver poorly aqueous soluble chemotherapeutic agents has several obstacles such as whole-body distribution, rapid excretion, degradation before reaching the infected site, side effects, etc. Nanoformulation of these aqueous insoluble agents is the emerging delivery system for targeted and increasing solubility. Among all the three methods (physical, chemical and biological) chemical and biological methods are mostly used for the synthesis of nanovehicles (NVs) of different sizes, shapes and dimensions. A passive targeting delivery system in which NVs supports the pharmacological agents (drugs/genes) is a good way for resolving the obstacles with a conventional delivery system. It enhances the therapeutic efficacy of pharmacological agents (drugs/genes). These NVs have several specific characters like small size, large surface area to volume ratio, surface functionalization, etc. However, this delivery is not able to deliver site-specific delivery of drugs. An active targeting delivery system in which pharmacological agents are loaded on NVs to attack directly on cancer cells and tissues is a superior way for delivering the pharmacological agents compared to a passive targeting delivery system. Various targeting ligands have been investigated and applied for targeting the delivery of drugs such as sugar, vitamin, antibodies, protein, peptides, etc. These targeted ligand supports to guide the NVs accumulated directly on the cancer cells with a higher level of cellular internalization compared to passive targeting and conventional delivery system.

Emulsion, hydrogel and emulgel systems and novel applications in cannabinoid delivery: a review

Emulsions, hydrogels and emulgels have attracted a high interest as tools for the delivery of poorly soluble hydrophobic nutraceuticals by enhancing their stability and bioavailability. This review provides an overview of these delivery systems, their unique qualities and their interactions with the human gastrointestinal system. The modulation of the various delivery systems to enhance the bioavailability and modify the release profile of bioactive encapsulates is highlighted. The application of the delivery systems in the delivery of cannabinoids is also discussed. With the recent increase of cannabis legalization across North America, there is much interest in developing cannabis edibles which can provide a consistent dose of cannabinoids per portion with a rapid time of onset. Indeed, the long time of onset of psychoactive effects and varied metabolic responses to these products result in a high risk of severe intoxication due to overconsumption. Sophisticated emulsion or hydrogel-based delivery systems are one potential tool to achieve this goal. To date, there is a lack of evidence linking specific classes of delivery systems with their pharmacokinetic profiles in humans. More research is needed to directly compare different classes of delivery systems for the gastrointestinal delivery of cannabinoids.

Silencing Osteopontin Expression Inhibits Proliferation, Invasion and Induce Altered Protein Expression in Melanoma Cells

Osteopontin (OPN) is a multifunctional phosphoprotein that is expressed in different types of cancers, including melanoma. OPN overexpression is associated with tumor progression and metastasis formation; however, the role of OPN in cell invasion and metastasis formation is not completely understood. In this study we aimed to define OPN expression in melanoma tissues and cell lines and investigate the effect of OPN expression on cell proliferation and invasion after inhibiting OPN expression with small interfering RNA (siRNA). OPN gene expression was determined by qRT-PCR, while protein expression was examined using a Proteome Profiler Oncology Array. siRNA-mediated OPN knockdown led to decreased OPN expression in melanoma cell lines, which was associated with decreased cell proliferation and invasion. Proteome profile analysis revealed significantly different protein expression between the original and transfected cell lines. The altered expression of the differently expressed proteins was validated at the mRNA level. Furthermore, OPN-specific siRNA was able to reduce OPN expression and inhibit the invasiveness of melanoma cells. Our results revealed for the first time that silencing the OPN gene influences proliferation and invasion of melanoma cells by effecting EGFR, tenascin C, survivin, galectin-3 and enolase 2 expression. To predict protein-protein interactions along with putative pathways we used STRING analysis for the differentially expressed proteins. These proteins formed multiple clusters, including extracellular matrix organization, regulation of angiogenesis, cell death and cell migration, PI3K-Akt, MAPK and focal adhesion signaling pathways. Taken together these data suggest that OPN might be an ideal target for drug development and therapies.

Cancer Nanomedicine

This Special Issue on Cancer Nanomedicine within Cancers brings together 46 cutting-edge papers covering research within the field along with insightful reviews and opinions reflecting our community [...].

Horizons of nanotechnology applications in female specific cancers

Female-specific cancers are the most common cancers in women worldwide. Early detection methods remain unavailable for most of these cancers, signifying that most of them are diagnosed at later stages. Furthermore, current treatment options for most female-specific cancers are surgery, radiation and chemotherapy. Although important milestones in molecularly targeted approaches have been achieved lately, current therapeutic strategies for female-specific cancers remain limited, ineffective and plagued by the emergence of chemoresistance, which aggravates prognosis. Recently, the application of nanotechnology to the medical field has allowed the development of novel nano-based approaches for the management and treatment of cancers, including female-specific cancers. These approaches promise to improve patient survival rates by reducing side effects, enabling selective delivery of drugs to tumor tissues and enhancing the uptake of therapeutic compounds, thus increasing anti-tumor activity. In this review, we focus on the application of nano-based technologies to the design of novel and innovative diagnostic and therapeutic strategies in the context of female-specific cancers, highlighting their potential uses and limitations.