Efficient delivery of small interfering RNA to bone-metastatic tumors by using atelocollagen in vivo

Zic family member 5 promotes RIO kinase 3 expression to enhance pancreatic cancer survival

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies with few effective therapies available. We previously determined the essential role of Zic family member 5 (ZIC5) in the survival of PDAC cells. In this study, we showed that targeting ZIC5 can effectively shrink PDAC tumors treated with gemcitabine in vivo and investigated the molecular mechanisms involved. When tumor-bearing mice were injected intravenously with ZIC5-targeting small interfering RNA, tumor volume was significantly reduced by gemcitabine treatment. RNA-sequencing analysis was used to identify the genes affected by ZIC5 knockdown. Among these, we selected the genes whose mRNA expression levels correlated with that of ZIC5 in pancreatic cancer and those associated with poor prognosis in patients with pancreatic cancer. Further analysis revealed that RIO kinase 3 (RIOK3) promotes PDAC cell survival, whereas ALDH3B1, PTGES, and TUFT1 contribute to gemcitabine resistance in MiaPaca-2 cells. We identified RIOK3 as a direct target gene of ZIC5 using ChIP and luciferase assays. Furthermore, stable expression of RIOK3 in PANC-1 cells reversed the reduction in cell number following ZIC5 knockdown. These findings highlight RIOK3 as a critical target of ZIC5, which is involved in survival signaling in PDAC cells.

Multifunctional DNA-Collagen Biomaterials: Developmental Advances and Biomedical Applications

The complexation of nucleic acids and collagen forms a platform biomaterial greater than the sum of its parts. This union of biomacromolecules merges the extracellular matrix functionality of collagen with the designable bioactivity of nucleic acids, enabling advances in regenerative medicine, tissue engineering, gene delivery, and targeted therapy. This review traces the historical foundations and critical applications of DNA-collagen complexes and highlights their capabilities, demonstrating them as biocompatible, bioactive, and tunable platform materials. These complexes form structures across length scales, including nanoparticles, microfibers, and hydrogels, a process controlled by the relative amount of each component and the type of nucleic acid and collagen. The broad distribution of different types of collagen within the body contributes to the extensive biological relevance of DNA-collagen complexes. Functional nucleic acids can form these complexes, such as siRNA, antisense oligonucleotides, DNA origami nanostructures, and, in particular, single-stranded DNA aptamers, often distinguished by their rapid self-assembly at room temperature and formation without external stimuli and modifications. The simple and seamless integration of nucleic acids within collagenous matrices enhances biomimicry and targeted bioactivity, and provides stability against enzymatic degradation, positioning DNA-collagen complexes as an advanced biomaterial system for many applications including angiogenesis, bone tissue regeneration, wound healing, and more.

Atelocollagen supports three-dimensional culture of human induced pluripotent stem cells

As autologous induced pluripotent stem cell (iPSC) therapy requires a custom-made small-lot cell production line, and the cell production method differs significantly from the existing processes for producing allogeneic iPSC stocks for clinical use. Specifically, mass culture to produce stock is no longer necessary; instead, a series of operations from iPSC production to induction of differentiation of therapeutic cells must be performed continuously. A three-dimensional (3D) culture method using small, closed-cell manufacturing devices is suitable for autologous iPSC therapy. The use of such devices avoids the need to handle many patient-derived specimens in a single clean room; handling of cell cultures in an open system in a cell processing facility increases the risk of infection. In this study, atelocollagen beads were evaluated as a 3D biomaterial to assist 3D culture in the establishment, expansion culture, and induction of differentiation of iPSCs. It was found that iPSCs can be handled in a closed-cell device with the same ease as use of a two-dimensional (2D) culture when laminin-511 is added to the medium. In conclusion, atelocollagen beads enable 3D culture of iPSCs, and the quality of the obtained cells is at the same level as those derived from 2D culture.

dsRNAi-mediated silencing of PIAS2beta specifically kills anaplastic carcinomas by mitotic catastrophe

The E3 SUMO ligase PIAS2 is expressed at high levels in differentiated papillary thyroid carcinomas but at low levels in anaplastic thyroid carcinomas (ATC), an undifferentiated cancer with high mortality. We show here that depletion of the PIAS2 beta isoform with a transcribed double-stranded RNA-directed RNA interference (PIAS2b-dsRNAi) specifically inhibits growth of ATC cell lines and patient primary cultures in vitro and of orthotopic patient-derived xenografts (oPDX) in vivo. Critically, PIAS2b-dsRNAi does not affect growth of normal or non-anaplastic thyroid tumor cultures (differentiated carcinoma, benign lesions) or cell lines. PIAS2b-dsRNAi also has an anti-cancer effect on other anaplastic human cancers (pancreas, lung, and gastric). Mechanistically, PIAS2b is required for proper mitotic spindle and centrosome assembly, and it is a dosage-sensitive protein in ATC. PIAS2b depletion promotes mitotic catastrophe at prophase. High-throughput proteomics reveals the proteasome (PSMC5) and spindle cytoskeleton (TUBB3) to be direct targets of PIAS2b SUMOylation at mitotic initiation. These results identify PIAS2b-dsRNAi as a promising therapy for ATC and other aggressive anaplastic carcinomas.

Implications of siRNA Therapy in Bone Health: Silencing Communicates

The global statistics of bone disorders, skeletal defects, and fractures are frightening. Several therapeutic strategies are being used to fix them; however, RNAi-based siRNA therapy is starting to prove to be a promising approach for the prevention of bone disorders because of its advanced capabilities to deliver siRNA or siRNA drug conjugate to the target tissue. Despite its 'bench-to-bedside' usefulness and approval by food and drug administration for five siRNA-based therapeutic medicines: Patisiran, Vutrisiran, Inclisiran, Lumasiran, and Givosiran, its use for the other diseases still remains to be resolved. By correcting the complications and complexities involved in siRNA delivery for its sustained release, better absorption, and toxicity-free activity, siRNA therapy can be harnessed as an experimental tool for the prevention of complex and undruggable diseases with a personalized medicine approach. The present review summarizes the findings of notable research to address the implications of siRNA in bone health for the restoration of bone mass, recovery of bone loss, and recuperation of bone fractures.

Knockdown of CPEB1 and CPEB4 Inhibits Scar Formation via Modulation of TAK1 and SMAD Signaling

BACKGROUND

Cytoplasmic polyadenylation element binding (CPEB) proteins are sequence-specific RNA-binding proteins that control translation via cytoplasmic polyadenylation. We previously reported that CPEB1 or CPEB4 knockdown suppresses TAK1 and SMAD signaling in an in vitro study.

OBJECTIVE

This study aimed to investigate whether suppression of CPEB1 or CPEB4 expression inhibits scar formation in a mice model of acute dermal wound healing.

METHODS

CPEB1 and CPEB4 expression levels were suppressed by siRNA treatment. Skin wounds were created by pressure-induced ulcers in mice. Images of the wound healing were obtained using a digital camera and contraction was measured by ImageJ. mRNA and protein expression was analyzed using quantitative real time polymerase chain reaction and western blotting, respectively.

RESULTS

Wound contraction was significantly decreased by pre-treatment with CPEB1 or CPEB4 siRNA compared to the control. Suppression of CPEB1 or CPEB4 expression decreased TAK1 signaling by reducing the levels of TLR4 and TNF-α, phosphorylated TAK1, p38, ERK, JNK, and NF-κB-p65. Decreased levels of phosphorylated SMAD2 and SMAD3 indicated a reduction in SMAD signaling as well. Consequently, the expression of α-SMA, fibronectin, and type I collagen decreased.

CONCLUSION

CPEB1 siRNA or CPEB4 siRNA inhibit scar formation by modulating the TAK1 and SMAD signaling pathways. Our study highlights CPEB1 and CPEB4 as potential therapeutic targets for the treatment of scar formation.

Elevated Alpha 1(I) to Alpha 2(I) Collagen Ratio in Dermal Fibroblasts Possibly Contributes to Fibrosis in Systemic Sclerosis

Systemic sclerosis (SSc) is characterized by excessive collagen deposition in the skin and internal organs. Activated fibroblasts are the key effector cells for the overproduction of type I collagen, which comprises the α1(I) and α2(I) chains encoded by COL1A1 and COL1A2, respectively. In this study, we examined the expression patterns of α1(I) and α2(I) collagen in SSc fibroblasts, as well as their co-regulation with each other. The relative expression ratio of COL1A1 to COL1A2 in SSc fibroblasts was significantly higher than that in control fibroblasts. The same result was observed for type I collagen protein levels, indicating that α2(I) collagen is more elevated than α2(I) collagen. Inhibition or overexpression of α1(I) collagen in control fibroblasts affected the α2(I) collagen levels, suggesting that α1(I) collagen might act as an upstream regulator of α2(I) collagen. The local injection of COL1A1 small interfering RNA in a bleomycin-induced SSc mouse model was found to attenuate skin fibrosis. Overall, our data indicate that α2(I) collagen is a potent regulator of type I collagen in SSc; further investigations of the overall regulatory mechanisms of type I collagen may help understand the aberrant collagen metabolism in SSc.

Liposome-polymer complex for drug delivery system and vaccine stabilization

Liposomes have been used extensively as micro- and nanocarriers for hydrophobic or hydrophilic molecules. However, conventional liposomes are biodegradable and quickly eliminated, making it difficult to be used for delivery in specific routes, such as the oral and systemic routes. One way to overcome this problem is through complexation with polymers, which is referred to as a liposome complex. The use of polymers can increase the stability of liposome with regard to pH, chemicals, enzymes, and the immune system. In some cases, specific polymers can condition the properties of liposomes to be explicitly used in drug delivery, such as targeted delivery and controlled release. These properties are influenced by the type of polymer, crosslinker, interaction, and bond in the complexation process. Therefore, it is crucial to study and review these parameters for the development of more optimal forms and properties of the liposome complex. This article discusses the use of natural and synthetic polymers, ways of interaction between polymers and liposomes (on the surface, incorporation in lamellar chains, and within liposomes), types of bonds, evaluation standards, and their effects on the stability and pharmacokinetic profile of the liposome complex, drugs, and vaccines. This article concludes that both natural and synthetic polymers can be used in modifying the structure and physicochemical properties of liposomes to specify their use in targeted delivery, controlled release, and stabilizing drugs and vaccines.

miRNA-148b and its role in various cancers

miRNA-148b belongs to the family miR-148/-152, with significant differences in nonseed sequences, which can target diverse mRNA molecules. Reportedly, it may undergo deregulation in lung and ovarian cancers and downregulation in gastric, pancreatic and colon cancers. However, there is a need for further studies to better characterize its mechanism of action and in different types of cancer. In this review, we focus on the aberrant expression of miR-148b in different cancer types and highlight its main target genes and signaling pathways, as well as its pathophysiologic role and relevance to tumorigenesis in several types of cancer.

Improved In Vivo Delivery of Small RNA Based on the Calcium Phosphate Method

In the past few years, we have demonstrated the efficacy of a nanoparticle system, super carbonate apatite (sCA), for the in vivo delivery of siRNA/miRNA. Intravenous injection of sCA loaded with small RNAs results in safe, high tumor delivery in mouse models. To further improve the efficiency of tumor delivery and avoid liver toxicity, we successfully developed an inorganic nanoparticle device (iNaD) via high-frequency ultrasonic pulverization combined with PEG blending during the production of sCA. Compared to sCA loaded with 24 μg of miRNA, systemic administration of iNaD loaded with 0.75 μg of miRNA demonstrated similar delivery efficiency to mouse tumors with little accumulation in the liver. In the mouse therapeutic model, iNaD loaded with 3 μg of the tumor suppressor small RNA MIRTX resulted in an improved anti-tumor effect compared to sCA loaded with 24 μg. Our findings on the bio-distribution and therapeutic effect of iNaD provide new perspectives for future nanomedicine engineering.

Effects of Inflammation on the Immune Microenvironment in Gastric Cancer

BACKGROUND

Chronic inflammation and immune cell dysfunction in the tumor microenvironment are key factors in the development and progression of gastric tumors. However, inflammation-related genes associated with gastric cancer prognosis and their relationship with the expression of immune genes are not fully understood.

METHOD

In this study, we established an inflammatory response model score called "Riskscore", based on differentially expressed genes in gastric cancer. We used Survival and Survminer packages in R to analyze patient survival and prognosis in risk groups. The survival curve was plotted using the Kaplan-Meier method, and the log-rank test was used to assess statistical significance, and we performed the ROC analysis using the R language package to analyze the 1-, 3-, and 5-year survival of patients in the GEO and TCGA databases. Single-factor and multi-factor prognostic analyses were carried out for age, sex, T, N, M, and risk score. Pathway enrichment analysis indicated immune factor-related pathway enrichment in both patient groups. Next, we screened for important genes that are involved in immune cell regulation. Finally, we created a correlation curve to explore the correlation between Riskscore and the expression of these genes.

RESULTS

The prognosis was significantly different between high- and low-risk groups, and the survival rate and survival time of the high-risk group were lower than those of the low-risk group. we found that the pathways related to apoptosis, hypoxia, and immunity were most enriched in the risk groups. we found two common tumor-infiltrating immune cell types (i.e., follicular helper T cells and resting dendritic cells) between the two risk groups and identified 10 genes that regulate these cells. Additionally, we found that these 10 genes are positively associated with the two risk groups.

CONCLUSION

Finally, a risk model of the inflammatory response in gastric cancer was established, and the inflammation-related genes used to construct the model were found to be directly related to immune infiltration. This model can improve the gastric cancer prognosis prediction. Our findings contribute to the development of immunotherapy for the treatment of gastric cancer patients.

Polymeric delivery systems for nucleic acid therapeutics: Approaching the clinic

Gene therapy using nucleic acids has many clinical applications for the treatment of diseases with a genetic origin as well as for the development of innovative vaccine formulations. Since nucleic acids in their free form are rapidly degraded by nucleases present in extracellular matrices, have poor pharmacokinetics and hardly pass cellular membranes, carrier systems are required. Suitable carriers that protect the nucleic acid payload against enzymatic attack, prolong circulation time after systemic administration and assist in cellular binding and internalization are needed to develop nucleic acid based drug products. Viral vectors have been investigated and are also clinically used as delivery vehicles. However, some major drawbacks are associated with their use. Therefore there has been substantial attention on the use of non-viral carrier systems based on cationic lipids and polymers. This review focuses on the properties of polymer-based nucleic acid formulations, also referred as polyplexes. Different polymeric systems are summarized, and the cellular barriers polyplexes encounter and ways to tackle these are discussed. Finally attention is given to the clinical status of non-viral nucleic acid formulations.

Targeting nanoparticles for diagnosis and therapy of bone tumors: Opportunities and challenges

A variety of targeted nanoparticles were developed for the diagnosis and therapy of orthotopic and metastatic bone tumors during the past decade. This critical review will focus on principles and methods in the design of these bone-targeted nanoparticles. Ligands including bisphosphonates, aspartic acid-rich peptides and synthetic polymers were grafted on nanoparticles such as PLGA nanoparticles, liposomes, dendrimers and inorganic nanoparticles for bone targeting. Besides, other ligands such as monoclonal antibodies, peptides and aptamers targeting biomarkers on tumor/bone cells were identified for targeted diagnosis and therapy. Examples of targeted nanoparticles for the early detection of bone metastatic tumors and the ablation of cancer via chemotherapy, photothermal therapy, gene therapy and combination therapy will be intensively reviewed. The development of multifunctional nanoparticles to break down the "vicious" cycle between tumor cell proliferation and bone resorption, and the challenges and perspectives in this area will be discussed.

Osteoblasts mineralization and collagen matrix are conserved upon specific Col1a2 silencing

Classical osteogenesis imperfecta (OI) is an inherited rare brittle bone disease caused by dominant mutations in the COL1A1 or COL1A2 genes, encoding for the α chains of collagen type I. The definitive cure for the disease will require a gene therapy approach, aimed to correct or suppress the mutant allele. Interestingly, individuals lacking α2(I) chain and synthetizing collagen α1(I)₃ homotrimers do not show bone phenotype, making appealing a bone specific COL1A2 silencing approach for OI therapy. To this aim, three different Col1a2-silencing RNAs (siRNAs), −3554, −3825 and −4125, selected at the 3′-end of the murine Col1a2 transcript were tested in vitro and in vivo. In murine embryonic fibroblasts Col1a2-siRNA-3554 was able to efficiently and specifically target the Col1a2 mRNA and to strongly reduce α2(I) chain expression. Its efficiency and specificity were also demonstrated in primary murine osteoblasts, whose mineralization was preserved. The efficiency of Col1a2-siRNA-3554 was proved also in vivo. Biphasic calcium phosphate implants loaded with murine mesenchymal stem cells were intramuscularly transplanted in nude mice and injected with Col1a2-siRNA-3554 three times a week for three weeks. Collagen α2 silencing was demonstrated both at mRNA and protein level and Masson's Trichrome staining confirmed the presence of newly formed collagen matrix. Our data pave the way for further investigation of Col1a2 silencing and siRNA delivery to the bone tissue as a possible strategy for OI therapy.

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Identification of a specific and efficient Col1a2 siRNA

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Silencing of Col1a2 allows osteoblasts mineralization.

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Col1a2 silencing is not impairing matrix deposition in vivo.

TSLP Exacerbates Septic Inflammation via Murine Double Minute 2 (MDM2) Signaling Pathway

Thymic stromal lymphopoietin (TSLP) is crucial for Th2-mediated inflammation. Sepsis is a serious systemic inflammatory reaction with organ dysfunction by infection. However, the function of TSLP during sepsis is poorly understood. Thus, we investigated a role and regulatory mechanism of TSLP during sepsis. Sepsis was induced by lipopolysaccharides (LPS) or Escherichia coli DH5α injection in mice. TSLP levels were measured in human subjects, mice, and macrophages. TSLP deficiency or murine double minute 2 (MDM2) deficiency was induced using siRNA or an MDM2 inhibitor, nutlin-3a. We found that TSLP levels were elevated in serum of patients and mice with sepsis. TSLP deficiency lowered liver damage and inflammatory cytokine levels in mice with sepsis. TSLP was produced by the MDM2/NF-κB signaling pathway in LPS-stimulated macrophages. TSLP downregulation by an MDM2 inhibitor, nutlin-3a, alleviated clinical symptoms and septic inflammatory responses. Pharmacological inhibition of TSLP level by cisplatin reduced the septic inflammatory responses. Altogether, the present results show that TSLP exacerbates septic inflammation via the MDM2 signaling pathway, suggesting that TSLP may be a potential target for the treatment of sepsis.

Increased EZH2 expression in prostate cancer is associated with metastatic recurrence following external beam radiotherapy

BACKGROUND

Enhancer of zeste 2 (EZH2) promotes prostate cancer progression. We hypothesized that increased EZH2 expression is associated with postradiotherapy metastatic disease recurrence, and may promote radioresistance.

METHODS

EZH2 expression was investigated using immunohistochemistry in diagnostic prostate biopsies of 113 prostate cancer patients treated with radiotherapy with curative intent. Associations between EZH2 expression in malignant and benign tissue in prostate biopsy cores and outcomes were investigated using univariate and multivariate Cox regression analyses. LNCaP and PC3 cell radiosensitivity was investigated using colony formation and γH2AX assays following UNC1999 chemical probe-mediated EZH2 inhibition.

RESULTS

While there was no significant association between EZH2 expression and biochemical recurrence following radiotherapy, univariate analysis revealed that prostate cancer cytoplasmic and total EZH2 expression were significantly associated with metastasis development postradiotherapy (P = 0.034 and P = 0.003, respectively). On multivariate analysis, the prostate cancer total EZH2 expression score remained statistically significant (P = 0.003), while cytoplasmic EZH2 expression did not reach statistical significance (P = 0.053). No association was observed between normal adjacent prostate EZH2 expression and biochemical recurrence or metastasis. LNCaP and PC3 cell treatment with UNC1999 reduced histone H3 lysine 27 tri-methylation levels. Irradiation of LNCaP or PC3 cells with a single 2 Gy fraction with UNC1999-mediated EZH2 inhibition resulted in a statistically significant, though modest, reduction in cell colony number for both cell lines. Increased γH2AX foci were observed 24 hours after ionizing irradiation in LNCaP cells, but not in PC3, following UNC1999-mediated EZH2 inhibition vs controls.

CONCLUSIONS

Taken together, these results reveal that high pretreatment EZH2 expression in prostate cancer in diagnostic biopsies is associated with an increased risk of postradiotherapy metastatic disease recurrence, but EZH2 function may only at most play a modest role in promoting prostate cancer cell radioresistance.

The long noncoding RNA HORAS5 mediates castration-resistant prostate cancer survival by activating the androgen receptor transcriptional program

Prostate cancer (PCa) is driven by the androgen receptor (AR)‐signaling axis. Hormonal therapy often mitigates PCa progression, but a notable number of cases progress to castration‐resistant PCa (CRPC). CRPC retains AR activity and is incurable. Long noncoding RNA (lncRNA) represent an uncharted region of the transcriptome. Several lncRNA have been recently described to mediate oncogenic functions, suggesting that these molecules can be potential therapeutic targets. Here, we identified CRPC‐associated lncRNA by analyzing patient‐derived xenografts (PDXs) and clinical data. Subsequently, we characterized one of the CRPC‐promoting lncRNA,HORAS5, in vitro and in vivo. We demonstrated that HORAS5 is a stable, cytoplasmic lncRNA that promotes CRPC proliferation and survival by maintaining AR activity under androgen‐depleted conditions. Most strikingly, knockdown of HORAS5 causes a significant reduction in the expression of AR itself and oncogenic AR targets such as KIAA0101. Elevated expression of HORAS5 is also associated with worse clinical outcomes in patients. Our results from HORAS5 inhibition in in vivo models further confirm that HORAS5 is a viable therapeutic target for CRPC. Thus, we posit that HORAS5 is a novel, targetable mediator of CRPC through its essential role in the maintenance of oncogenic AR activity. Overall, this study adds to our mechanistic understanding of how lncRNA function in cancer progression.

Protein-based vehicles for biomimetic RNAi delivery

Broad translational success of RNA interference (RNAi) technology depends on the development of effective delivery approaches. To that end, researchers have developed a variety of strategies, including chemical modification of RNA, viral and non-viral transfection approaches, and incorporation with delivery vehicles such as polymer- and lipid-based nanoparticles, engineered and native proteins, extracellular vesicles (EVs), and others. Among these, EVs and protein-based vehicles stand out as biomimetically-inspired approaches, as both proteins (e.g. Apolipoprotein A-1, Argonaute 2, and Arc) and EVs mediate intercellular RNA transfer physiologically. Proteins specifically offer significant therapeutic potential due to their biophysical and biochemical properties as well as their ability to facilitate and tolerate manipulation; these characteristics have made proteins highly successful translational therapeutic molecules in the last two decades. This review covers engineered protein vehicles for RNAi delivery along with what is currently known about naturally-occurring extracellular RNA carriers towards uncovering design rules that will inform future engineering of protein-based vehicles.

Anisamide-targeted PEGylated gold nanoparticles designed to target prostate cancer mediate: Enhanced systemic exposure of siRNA, tumour growth suppression and a synergistic therapeutic response in combination with paclitaxel in mice

Small interfering RNA (siRNA) has recently illustrated therapeutic potential for malignant disorders. However, the clinical application of siRNA-based therapeutics is significantly retarded by the paucity of successful delivery systems. Recently, multifunctional gold nanoparticles (AuNPs) as non-viral delivery carriers have shown promise for transporting chemotherapeutics, proteins/peptides, and genes. In this study, AuNPs capped with polyethylenimine (PEI) and PEGylated anisamide (a ligand known to target the sigma receptor) have been developed to produce a range of positively charged anisamide-targeted PEGylated AuNPs (namely Au-PEI-PEG-AA). The anisamide-targeted AuNPs effectively complexed siRNA via electrostatic interaction, and the resultant complex (Au₁₁₀-PEI-PEG₅₀₀₀-AA.siRNA) illustrated favourable physicochemical characteristics, including particle size, surface charge, and stability. In vitro, anisamide-targeted AuNPs selectively bound to human prostate cancer PC-3 cells, inducing efficient endosomal escape of siRNA, and effective downregulation of the RelA gene. In vivo, prolonged systemic exposure of siRNA was achieved by anisamide-targeted AuNPs resulting in significant tumour growth suppression in a PC3 xenograft mouse model without an increase in toxicity. In addition, a combination of siRNA-mediated NF-κB knockdown using anisamide-targeted AuNPs with Paclitaxel produced a synergistic therapeutic response, thus providing a promising therapeutic strategy for the treatment of prostate cancer.

MicroRNA replacement therapy in cancer

Despite the recent progress in cancer management approaches, the mortality rate of cancer is still growing and there are lots of challenges in the clinics in terms of novel therapeutics. MicroRNAs (miRNA) are regulatory small noncoding RNAs and are already confirmed to have a great role in regulating gene expression level by targeting multiple molecules that affect cell physiology and disease development. Recently, miRNAs have been introduced as promising therapeutic targets for cancer treatment. Regulatory potential of tumor suppressor miRNAs, which enables regulation of entire signaling networks within the cells, makes them an interesting option for developing cancer therapeutics. In this regard, over recent decades, scientists have aimed at developing powerful and safe targeting approaches to restore these suppressive miRNAs in cancerous cells. The present review summarizes the function of miRNAs in tumor development and presents recent findings on how miRNAs have served as therapeutic agents against cancer, with a special focus on tumor suppressor miRNAs (mimics). Moreover, the latest investigations on the therapeutic strategies of miRNA delivery have been presented.

Targeting Cancer with Peptide RNAi Nanoplexes

With the recent explosion of genomic information on the root causes of disease, there is an increased interest in nucleic acid therapeutics, including siRNA and gene therapy, all of which require delivery of highly charged nucleic acids from siRNA with a molecular weight of about 1.4 × 10⁴ to plasmids with an approximate molecular weight of 2.0-3.0 × 10⁶. This chapter describes the delivery of shRNA via plasmid or siRNA with a peptide-based carrier. We focus on the histidine-lysine peptide which serves as an example for other peptides and polymeric carrier systems. When the HK peptide and nucleic acids are mixed together and interact with one another through ionic and nonionic interactions, nanoplexes are formed. These nanoplexes, carrying either shRNA or siRNA that target oncogenes, provide promising options for the treatment of cancer. We describe methods of preparation and characterization of these nanoplexes using dynamic light scattering, zeta potential, and gel retardation assays. We also provide protocols for transfection in vitro and in vivo for these nanoplexes.

Targeted Nanomedicine to Treat Bone Metastasis

Bone metastases are common complications of solid tumors, particularly those of the prostate, breast, and lungs. Bone metastases can lead to painful and devastating skeletal-related events (SREs), such as pathological fractures and nerve compressions. Despite advances in treatment for cancers in general, options for bone metastases remain inadequate and generally palliative. Anticancer drugs (chemotherapy and radiopharmaceuticals) do not achieve therapeutic concentrations in the bone and are associated with dose-limiting side effects to healthy tissues. Nanomedicines, with their tunable characteristics, have the potential to improve drug targeting to bone metastases while decreasing side effects for their effective treatment. In this review, we present the current state of the art for nanomedicines to treat bone metastases. We also discuss new treatment modalities enhanced by nanomedicine and their effects on SREs and disease progression.

Treating metastatic prostate cancer with microRNA-145

Prostate cancer (PCa) is an incurable disease at the metastatic stage. Although there are different options for treatment, the results are limited. MicroRNAs (miRNAs) are a group of small, noncoding, regulatory RNAs with important roles in regulating gene expression. miR-145 is reported to be a key tumor suppressor miRNA (tsmiR) that controls important oncogenes, such as MYC and RAS. In this study, in vitro studies were performed to show the control of MYC and RAS by miR-145. Flow cytometry was used to analyze cell proliferation and apoptosis. The efficacy of miR-145 in treating metastatic PCa was tested in nude mice using a model of bone metastasis promoted by intraventricular injection of PC-3MLuc-C6 cells. Tumor growth was evaluated by an in vivo bioluminescence system. After the full establishment of metastases on day 21, six animals were treated with three intravenous doses of miR-145 (on days 21, 24 and 27), and six were injected with scramble miRNA as controls. Compared to the controls, tumor growth was significantly reduced in animals receiving miR-145, most importantly on day 7 after the third and last dose of miRNA. After discontinuing the treatment, tumor growth resumed, becoming similar to the group of non-treated animals. A decrease in MYC and RAS expression was observed in all cell lines after treatment with miR-145, although statistical significance was achieved only in experiments with LNCaP and PC3 cell lines, with a decrease in 56% (p = 0.012) and 31% (p = 0.013) of RAS expression, respectively. Our results suggest that miR-145 is a potential molecule to be tested for treatment of metastatic, castration-resistant PCa.

Charge reversible calcium phosphate lipid hybrid nanoparticle for siRNA delivery

Bcl-2 gene is an important target to treat lung cancer. The small interference RNA (siRNA) of Bcl-2 gene (siBcl-2) can specifically silence Bcl-2 gene. However, naked siBcl-2 is difficult to accumulate in the tumor tissue to exert its activity. In this paper, a calcium phosphate lipid hybrid nanoparticle that possessed charge reversible property was prepared to enhance the activity of siBcl-2 in vivo. The average diameter and zeta potential of siBcl-2 loaded calcium phosphate lipid hybrid nanoparticles (LNPS@siBcl-2) were 80 nm and −13 mV at pH7.4 whereas the diameter and zeta potential changed to 1506 nm and +9 mV at pH5.0. LNPS@siBcl-2 could efficiently deliver siBcl-2 to the cytoplasm and significantly decreased the expression of Bcl-2 in A549 cells. Moreover, the in vivo experimental results showed that most of the Cy5-siBcl-2 accumulated in tumor tissue after LNPS@Cy5-siBcl-2 was administered to tumor-bearing mice by tail vein injection. Meanwhile, the expression of Bcl-2 was decreased but the expression of the BAX and Caspase-3 was increased in tumor tissue. LNPS@siBcl-2 significantly inhibited the growth of tumor in tumor-bearing mice without any obvious systemic toxicity. Thus, the charge reversible calcium phosphate lipid hybrid nanoparticle was an excellent siBcl-2 delivery carrier to improve the activity of siBcl-2 in vivo. LNPS@siBcl-2 has potential in the treatment of lung cancer.

Photomodulating Gene Expression by Using Caged siRNAs with Single-Aptamer Modification

Caged siRNAs incorporating terminal modification were rationally designed for photochemical regulation of gene silencing induced by RNA interference (RNAi). Through the conjugation of a single oligonucleotide aptamer at the 5' terminus of the antisense RNA strand, enhancement of the blocking effect for RNA-induced silencing complex (RISC) formation/processing was expected, due both/either to the aptamers themselves and/or to their interaction with large binding proteins. Two oligonucleotide aptamers (AS1411 and MUC-1) were chosen for aptamer-siRNA conjugation through a photolabile linker. This caging strategy was successfully used to photoregulate gene expression both of firefly luciferase and of green fluorescent protein (GFP) in cells. Further patterning experiments revealed that spatial regulation of GFP expression was successfully achieved by using the aptamer-modified caged siRNA and light activation. We expect that further optimized caged siRNAs featuring aptamer conjugation will be promising for practical applications to spatiotemporal photoregulation of gene expression in the future.

Delivery of Small Interfering RNA. A Review and an Example of Application to a Junction Oncogene

RNA interference strategies using small interfering RNA is one of the most important discoveries in biology in recent years. This technology alongside antisense oligonucleotides is very promising and our group has focused its work on the targeting of junction oncogenes with these molecules. We have taken, as first example, papillary thyroid carcinoma. But there is a great need in delivery methods for these molecules in the treatment of cancers. Indeed, many studies have shown that small interfering RNA and antisense oligonucleotides are made efficient by various innovative delivery methods and, under these conditions, offer a powerful new therapeutic tool in cancer treatment.

Development of magnetic anionic liposome/atelocollagen complexes for efficient magnetic drug targeting

Magnetic nanoparticle-incorporated liposomes (magnetic liposomes) are considered a promising site-specific drug delivery carrier vehicle. With regard to their surface charge, magnetic anionic liposomes (Mag-AL) demonstrate little toxicity in comparison with magnetic cationic liposomes (Mag-CL), whereas their cellular association and uptake efficiency are low. In the current study, we constructed complexes of Mag-AL and atelocollagen (ATCOL), which is a biocompatible and minimally immunogenic biomaterial, to improve the cellular uptake properties of Mag-AL in vitro and in vivo. The cellular association and/or uptake of Mag-AL in RAW264 cells, a murine macrophage-like cell line, under a magnetic field was significantly increased when Mag-AL was complexed with ATCOL, and the highest cellular association was observed with complexes constructed using 5 µg/mL of ATCOL. The complexes showed liposome concentration-dependent and time-dependent cellular association under a magnetic field, and their cellular uptake efficiency was comparable with that of Mag-CL. In addition, Mag-CL showed significant cytotoxicity in a liposome concentration-dependent manner, whereas Mag-AL/ATCOL complexes produced no cytotoxic effect against RAW264 cells. Furthermore, the efficient cellular association of Mag-AL/ATCOL complexes in RAW264 cells was observed even in the presence of serum, and their liver accumulation was significantly increased at a magnetic field-exposed region after intravenous injection in rats. These results indicate that Mag-AL/ATCOL complexes could be a safe and efficient magnetic responsive drug carrier.

ECM turnover-stimulated gene delivery through collagen-mimetic peptide-plasmid integration in collagen

Gene therapies have great potential in regenerative medicine; however, clinical translation has been inhibited by low stability and limited transfection efficiencies. Herein, we incorporate collagen-mimetic peptide (CMP)-linked polyplexes in collagen scaffolds to increase DNA stability by up to 400% and enable tailorable in vivo transgene expression at 100-fold higher levels and 10-fold longer time periods. These improvements were directly linked to a sustained interaction between collagen and polyplexes that persisted during cellular remodeling, polyplex uptake, and intracellular trafficking. Specifically, incorporation of CMPs into polyethylenimine (PEI) polyplexes preserved serum-exposed polyplex-collagen activity over a period of 14days, with 4 orders-of-magnitude more intact DNA present in CMP-modified polyplex-collagen relative to unmodified polyplex-collagen after a 10day incubation under cell culture conditions. CMP-modification also altered endocytic uptake, as indicated by gene silencing studies showing a nearly 50% decrease in transgene expression in response to caveolin-1 silencing in modified samples versus only 30% in unmodified samples. Furthermore, cellular internalization studies demonstrated that polyplex-collagen association persisted within cells in CMP polyplexes, but not in unmodified polyplexes, suggesting that CMP linkage to collagen regulates intracellular transport. Moreover, experiments in an in vivo repair model showed that CMP modification enabled tailoring of transgene expression from 4 to 25days over a range of concentrations. Overall, these findings demonstrate that CMP decoration provides substantial improvements in gene retention, altered release kinetics, improved serum-stability, and improved gene activity in vivo. This versatile technique has great potential for multiple applications in regenerative medicine.

STATEMENT OF SIGNIFICANCE

In this work, we demonstrate a novel approach for stably integrating DNA into collagen scaffolds to exploit the natural process of collagen remodelling for high efficiency non-viral gene delivery. The incorporation of CMPs into DNA polyplexes, coupled with the innate affinity between CMPs and collagen, not only permitted improved control over polyplex retention and release, but also provided a series of substantial and highly unique benefits via the stable and persistent linkage between CMP-polyplexes and collagen fragments. Specifically, CMP-modification of polyplexes was demonstrated to (i) control release for nearly a month, (ii) improve vector stability under physiological-like conditions, and (iii) provide ligands able to efficiently transfer genes via endocytic collagen pathways. These unique properties overcome key barriers inhibiting non-viral gene therapy.

Genome-wide ChIP-seq analysis of EZH2-mediated H3K27me3 target gene profile highlights differences between low- and high-grade astrocytic tumors

Enhancer of zeste homolog-2(EZH2) is a key epigenetic regulator that functions as oncogene and also known for inducing altered trimethylation of histone at lysine-27 (H3K27me3) mark in various tumors. However, H3K27me3 targets and their precise relationship with gene expression are largely unknown in astrocytic tumors. In this study, we checked EZH2 messenger RNA and protein expression in 90 astrocytic tumors of different grades using quantitative PCR and immunohistochemistry, respectively. Further, genome-wide ChIP-seq analysis for H3K27me3 modification was also performed on 11 glioblastomas (GBMs) and 2 diffuse astrocytoma (DA) samples. Our results showed EZH2 to be highly overexpressed in astrocytic tumors with a significant positive correlation with grade. Interestingly, ChIP-seq mapping revealed distinct differences in genes and pathways targeted by these H3K27me3 modifications between GBM versus DA. Neuroactive ligand receptor pathway was found most enriched in GBM (P = 9.4 × 10-25), whereas DA were found to be enriched in metabolic pathways. Also, GBM showed a higher enrichment of H3K27me3 targets reported in embryonic stem cells and glioma stem cells as compared with DAs. Our results show majority of these H3K27me3 target genes were downregulated, not only due to H3K27me3 modification but also due to concomitant DNA methylation. Further, H3K27me3 modification-associated gene silencing was not restricted to promoter but also present in gene body and transcription start site regions. To the best of our knowledge, this is the first high-resolution genome-wide mapping of H3K27me3 modification in adult astrocytic primary tissue samples of human, highlighting the differences between grades. Interestingly, we identified SLC25A23 as important target of H3K27me3 modification, which was downregulated in GBM and its low expression was associated with poor prognosis in GBMs.

Atelocollagen-mediated in vivo siRNA transfection in ovarian carcinoma is influenced by tumor site, siRNA target and administration route

Ovarian cancer is the leading cause of death from gynecological malignancies worldwide, and innate or acquired chemoresistance of ovarian cancer cells is the major cause of therapeutic failure. It has been demonstrated that the concomitant inhibition of Bcl-xL and Mcl-1 anti-apoptotic activities is able to trigger apoptosis in chemoresistant ovarian cancer cells. In this context, siRNA-mediated Bcl‑xL and Mcl-1 inhibition constitutes an appealing strategy by which to eliminate chemoresistant cancer cells. However, the safest and most efficient way to vectorize siRNAs in vivo is still under debate. In the present study, using in vivo bioluminescence imaging, we evaluated the interest of atelocollagen to vectorize siRNAs by intraperitoneal (i.p.) or intravenous (i.v.) administration in 2 xenografted ovarian cancer models (peritoneal carcinomatosis and subcutaneous tumors in nude mice). Whereas i.p. administration of atelocollagen-vectorized siRNA in the peritoneal carcinomatosis model did not induce any gene downregulation, a 70% transient downregulation of luciferase expression was achieved after i.v. injection of atelocollagen-vectorized siRNA in the subcutaneous (s.c.) model. However, the use of siRNA targeting Bcl-xL or Mcl-1 did not induce target-specific downregulation in vivo in nude mice. Our results therefore show that atelocollagen complex formulation, the administration route, tumor site and the identity of the siRNA target influence the efficiency of atelocollagen‑mediated siRNA delivery.

Specific Depletion of Leukemic Stem Cells: Can MicroRNAs Make the Difference?

For over 40 years the standard treatment for acute myeloid leukemia (AML) patients has been a combination of chemotherapy consisting of cytarabine and an anthracycline such as daunorubicin. This standard treatment results in complete remission (CR) in the majority of AML patients. However, despite these high CR rates, only 30–40% (<60 years) and 10–20% (>60 years) of patients survive five years after diagnosis. The main cause of this treatment failure is insufficient eradication of a subpopulation of chemotherapy resistant leukemic cells with stem cell-like properties, often referred to as “leukemic stem cells” (LSCs). LSCs co-exist in the bone marrow of the AML patient with residual healthy hematopoietic stem cells (HSCs), which are needed to reconstitute the blood after therapy. To prevent relapse, development of additional therapies targeting LSCs, while sparing HSCs, is essential. As LSCs are rare, heterogeneous and dynamic, these cells are extremely difficult to target by single gene therapies. Modulation of miRNAs and consequently the regulation of hundreds of their targets may be the key to successful elimination of resistant LSCs, either by inducing apoptosis or by sensitizing them for chemotherapy. To address the need for specific targeting of LSCs, miRNA expression patterns in highly enriched HSCs, LSCs, and leukemic progenitors, all derived from the same patients’ bone marrow, were determined and differentially expressed miRNAs between LSCs and HSCs and between LSCs and leukemic progenitors were identified. Several of these miRNAs are specifically expressed in LSCs and/or HSCs and associated with AML prognosis and treatment outcome. In this review, we will focus on the expression and function of miRNAs expressed in normal and leukemic stem cells that are residing within the AML bone marrow. Moreover, we will review their possible prospective as specific targets for anti-LSC therapy.

The Effect of Sodium Valproate on the Glioblastoma U87 Cell Line Tumor Development on the Chicken Embryo Chorioallantoic Membrane and on EZH2 and p53 Expression

Literature data support evidences that glioblastoma (GBM) patients experience prolonged survival due to sodium valproate (NaVP) treatment. The study assessed the human GBM cell U87 xenograft studied in the chicken embryo chorioallantoic membrane (CAM) model evaluating NaVP effect on tumor. Three groups of tumors (each n = 10) were studied: nontreated, treated with 4 mM, and treated with 8 mM of NaVP. The majority of tumors without NaVP treatment during tumor growth destroyed the chorionic epithelium, invaded the mesenchyme, and induced angiogenesis. Incidence of tumor formation on CAM without invasion into the mesenchyme was higher when U87 cells were treated with NaVP; the effect significantly increased with NaVP concentration. Treatment with 8 mM of NaVP did not show clear dynamics of tumor growth during 5 days; at the same time, the angiogenesis failed. With a strong staining of EZH2, p53 in tumors without NaVP treatment was found, and NaVP significantly decreased the expression of EZH2- and p53-positive cells; the effect was significantly higher at its 8 mM concentration. NaVP has a function in blocking the growth, invasion, and angiogenesis of tumor in the CAM model; tumor growth interferes with EZH2 and p53 molecular pathways, supporting the NaVP potential in GBM therapy.

Prospects of siRNA applications in regenerative medicine

Small interfering RNA (siRNA) has established its reputation in the field of tissue engineering owing to its ability to silence the proteins that inhibit tissue regeneration. siRNA is capable of regulating cellular behavior during tissue regeneration processes. The concept of using siRNA technology in regenerative medicine derived from its ability to inhibit the expression of target genes involved in defective tissues and the possibility to induce the expression of tissue-inductive factors that improve the tissue regeneration process. To date, siRNA has been used as a suppressive biomolecule in different tissues, such as nervous tissue, bone, cartilage, heart, kidney, and liver. Moreover, various delivery systems have been applied in order to deliver siRNA to the target tissues. This review will provide an in-depth discussion on the development of siRNA and their delivery systems and mechanisms of action in different tissues.

An Atelocollagen Coating for Efficient Local Gene Silencing by Using Small Interfering RNA

In the last decades, many efforts have been made to counteract adverse effects after stenting atherosclerotic coronary arteries. A breakthrough in better vascular wall regeneration was noted in the new era of drug-eluting stents. A novel personalized approach is the development of gene-eluting stents promising an alteration in gene expression involved in regeneration. We investigated a coating system consisting of the polymer atelocollagen (ATCOL) and a specific small interfering RNA (siRNA) for intercellular adhesion molecule-1 (ICAM-1) found on the surface of defective endothelial cells (ECs). We demonstrated very high cell viability, in which EA.hy926 grew on 0.008% or 0.032% ATCOL layers. Additionally, hemocompatibility assays proved the biocompatibility of this coating. The highest transfection efficiency with EA.hy926 was achieved with 5 μg siRNA immobilized in ATCOL after 2 days. The release of fluorescent-labeled siRNA was about 9 days. Long-term knockdown of ICAM-1 was analyzed by flow cytometry, revealing that the coating with 0.008% ATCOL and 5 μg siICAM-1 provoked gene silencing up to 8 days. 5′-RNA ligase-mediated rapid amplification of cDNA ends PCR (RLM-RACE-PCR) demonstrated the specificity of our established ATCOL gene-silencing coating, meaning that our coating is well suited for further investigations in in vivo studies. Herein, we would like to demonstrate that our ATCOL is well-suited for better artery wall regeneration after stent implantation.

History of Polymeric Gene Delivery Systems

As an option for genetic disease treatment and an alternative for traditional cancer chemotherapy, gene therapy achieves significant attention. Nucleic acid delivery, however, remains a main challenge in human gene therapy. Polymer-based delivery systems offer a safer and promising route for therapeutic gene delivery. Over the past five decades, various cationic polymers have been optimized for increasingly effective nucleic acid transfer. This resulted in a chemical evolution of cationic polymers from the first-generation polycations towards bioinspired multifunctional sequence-defined polymers and nanocomposites. With the increasing of knowledge in molecular biological processes and rapid progress of macromolecular chemistry, further improvement of polymeric nucleic acid delivery systems will provide effective tool for gene-based therapy in the near future.

Identification of differentially expressed genes in salivary adenoid cystic carcinoma cells associated with metastasis

INTRODUCTION

Salivary adenoid cystic carcinoma (SACC) is a frequent type of salivary gland cancer which is characterized by slow growth but high incidence of distant metastasis. We aimed to identify therapeutic targets which are associated with metastasis of SACC.

MATERIAL AND METHODS

Total RNA was isolated from a low metastatic SACC cell line (ACC-2) and a highly metastatic SACC cell line (ACC-M), which was screened from ACC-2 by combination of in vivo selection and cloning in vitro. Then the total RNA was subjected to microarray analysis. Differentially expressed genes (DEGs) were screened from ACC-M compared with ACC-2, followed by Gene Ontology function and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. Function annotation for DEGs also was performed. A protein-protein interaction network (PPI) was constructed for DEGs.

RESULTS

A total of 1128 DEGs were identified from ACC-M cells compared with ACC-2 cells. Both up- and down-regulated DEGs were enriched in different functions in biological process (BP), cellular component (CC) and molecular function (MF). Additionally, down-regulated DEGs were mainly enriched in "Apoptosis" and "Cytokine-cytokine receptor interaction" pathways which involved IFN-α1, NTRK1 and TGF-β1. In the PPI network, PIK3CA, PTPN11 and PIK3R1 had a number of nodes greater than 10.

CONCLUSIONS

Transforming growth factor β1 might play a pivotal role during lung metastasis of SACC and be selected as a candidate target for treatment of metastatic SACC. IFNA1, NTRK1 and PIK3CA were also associated with tumor metastasis.

Glycolysis inhibition as a cancer treatment and its role in an anti-tumour immune response

Increased glycolysis is the main source of energy supply in cancer cells that use this metabolic pathway for ATP generation. Altered energy metabolism is a biochemical fingerprint of cancer cells that represents one of the "hallmarks of cancer". The immune system can prevent tumour growth by eliminating cancer cells but this editing process ultimately results in poorly immunogenic cells remaining allowing for unchallenged tumour growth. In this review we look at the glycolysis pathway as a target for cancer treatments. We also examine the interplay between the glycolysis modulation and the immune response as an anti-cancer therapy.

Delivery of siRNA to ovarian cancer cells using laser-activated carbon nanoparticles

AIM

The RNAi-mediated knockdown of gene expression is an attractive tool for research and therapeutic purposes but its implementation is challenging. Here we report on a new method based on photoacoustic delivery of siRNA developed to address some of these challenges.

MATERIALS & METHODS

Physical properties and photoacoustic emission of carbon black (CB) particles upon near-infrared laser irradiation were characterized. Next, ovarian cancer cells Hey A8-F8 were exposed to near-infrared nanosecond laser pulses in the presence of siRNA targeting EGFR gene and CB particles. The intracellular delivery of siRNA and silencing of the target gene were determined by specific qPCR assays.

RESULTS & CONCLUSION

Laser-activated CB nanoparticles generated photoacoustic emission and enabled intracellular delivery of siRNA and significant knockdown of its target EGFR mRNA. This physical method represents a new promising approach to targeted therapeutic delivery of siRNA.

A therapeutic trial of human melanomas with combined small interfering RNAs targeting adaptor molecules p130Cas and paxillin activated under expression of ganglioside GD3

We previously demonstrated that focal adhesion kinase (FAK), p130Cas and paxillin are crucially involved in the enhanced malignant properties under expression of ganglioside GD3 in melanoma cells. Therefore, molecules existing in the GD3-mediated signaling pathway could be considered as suitable targets for therapeutic intervention in malignant melanoma. The aim of this study was to determine whether blockade of p130Cas and/or paxillin by RNAi suppresses melanoma growth. We found a suitable dose (40 μM siRNA, 25 μl/tumor) of the siRNA to suppress p130Cas in the xenografts generated in nu/nu mice. Based on these results, we performed intratumoral (i.t.) treatment with anti-p130Cas and/or anti-paxillin siRNAs mixed with atelocollagen as a drug delivery system in a xenograft tumor of a human melanoma cell line, SK-MEL-28. Mixture of atelocollagen (1.75%) and an siRNA (500 or 1000 pmol/tumor) was injected into the tumors every 3 days after the first injection. An siRNA against human p130Cas markedly suppressed tumor growth of the xenograft in a dose-dependent manner, whereas siRNA against human paxillin slightly inhibited the tumor growth. A control siRNA against firefly luciferase showed no effect. To our surprise, siRNA against human p130Cas (500 or 1000 pmol/tumor) combined with siRNA against human paxillin dramatically suppressed tumor growth. In agreement with the tumor suppression effects of the anti-p130Cas siRNA, reduction in Ki-67 positive cell number as well as in p130Cas expression was demonstrated by immunohistostaining. These results suggested that blockade of GD3-mediated growth signaling pathways by siRNAs might be a novel and promising therapeutic strategy against malignant melanomas, provided signaling molecules such as p130Cas and paxillin are significantly expressed in individual cases. This article is part of a Special Issue entitled "Glycans in personalised medicine" Guest Editor: Professor Gordan Lauc.

Short interfering RNA therapeutics: nanocarriers, prospects and limitations

Since the first experiment depicting gene inhibition using RNA interference mechanism, extensive research has been carried out to design targeted delivery systems that use short interfering RNAs (siRNAs) for gene expression regulation. Although several siRNAs loaded nanoparticle systems have reached clinical trial stage, cellular uptake, reticuloendothelial entrapment and endosomal escape still limit the efficacy of these drugs considerably. This review discusses about the RNA interference mechanism, nanostructures being used as non-viral vectors for targeted delivery, limitations of the common delivery systems and the current siRNA-loaded nanoparticle formulations undergoing clinical testing.

Silver nanoparticles-quercetin conjugation to siRNA against drug-resistant Bacillus subtilis for effective gene silencing: in vitro and in vivo

Quercetin (Qe) exhibited extremely low water solubility, and thus, it was modified using silver nanoparticles (AgNPs). We fabricated AgNPs combined with Qe (AgNPs-Qe). The modification suggested that the synergistic properties of Qe enhanced the antibacterial activity of AgNPs. However, AgNPs-Qe exerted no effect on many kinds of drug-resistant bacteria, including Pseudomonas aeruginosa and Bacillus subtilis. RNA interference has considerable therapeutic potential because of its high specificity and potential capability to evade drug resistance. Therefore, we stabilized AgNPs-Qe with a layer of molecules (siRNA). The newly fabricated nanoparticles exerted improved effect on many kinds of bacteria, including the most prominent drug-resistant species B. subtilis. Agarose gel electrophoresis showed that the highest critical nitrogen-to-phosphorus (N/P) ratio occurred at a vector/siRNA with a w/w ratio of 7:1. Characterization experiment indicated that the diameter of siRNA/AgNPs-Qe was approximately 40 nm (40 ± 10 nm). Moreover, AgNPs-Qe were stabilized with a layer of siRNA that was approximately 10nm thick. Results of the in vitro study suggested that siRNA/AgNPs-Qe could destroy the cell wall and inhibit bacterial propagation. Meanwhile, the in vivo experiment on the animal bacteremia model, as well as the optical imaging of nude mice and their isolated organs, demonstrated that bacteria accumulated in the blood, heart, liver, spleen, lungs, and kidneys after the intravenous injection of B. subtilis. The bacteria in the blood and organs, as well as the inflamed cells in the tissues, gradually decreased after the mice received intravenous tail injection of siRNA/AgNPs-Qe for treatment. Both the in vitro and the in vivo studies exhibit that siRNA/AgNPs-Qe can be a potential nanoscale drug delivery system for B. subtilis targeting bacterimia.

Carotenoid Nanovector for Efficient Therapeutic Gene Knockdown of Transcription Factor FOXC1 in Liver Cancer

Transcription factor FOXC1 has been implicated to play a critical role in hepatocellular carcinoma (HCC) progression, but targeting FOXC1 for therapeutic benefit remains a challenge owing to its location inside the cell nucleus. Herein we report successful therapeutic gene knockdown of transcription factor FOXC1 in liver cancer cells through efficient delivery of siFOXC1 using novel carotenoid functionalized dendritic nanoparticles (CDN). This delivery system also displayed a markedly reduced toxicity profile compared to a standard siRNA transfection agent. We were able to achieve ∼90% FOXC1 knockdown using the CDN-siFOXC1 complex. Additionally, it was found to have ∼18% greater delivery efficiency compared to treatments with particles which have no carotenoid tagging, thereby emphasizing the role of carotenoid mediated cell internalization in the efficient delivery of CDN-siFOXC1 complex in liver cancer cells.

RNA interference targeting carbohydrate sulfotransferase 3 diminishes macrophage accumulation, inhibits MMP-9 expression and promotes lung recovery in murine pulmonary emphysema

BACKGROUND

Chondroitin sulfate proteoglycans are an important mediators in inflammation and leukocyte trafficking. However, their roles in pulmonary emphysema have not been explored. In a murine model of elastase-induced pulmonary emphysema, we found increased carbohydrate sulfotransferase 3 (CHST3), a specific enzyme that synthesizes chondroitin 6-sulfate proteoglycan (C6SPG). To elucidate the role of C6SPG, we investigated the effect of small interfering RNA (siRNA) targeting CHST3 that inhibits C6SPG-synthesis on the pathogenesis of pulmonary emphysema.

METHODS

Mice were intraperitoneally injected with CHST3 siRNA or negative control siRNA on day0 and 7 after intratracheal instillation of elastase. Histology, respiratory function, glycosaminoglycans (GAGs) content, bronchoalveolar lavage (BAL), elastin staining and gene expressions of tumor necrosis factor (TNF)-α and matrix metalloproteinase (MMP)-9 mRNA were evaluated on day7 and/or day21.

RESULTS

CHST3 mRNA increased at day 7 and decreased thereafter in lung. CHST3 siRNA successfully inhibited the expression of CHST3 mRNA throughout the study and this was associated with significant reduction of GAGs and C6SPG. Airway destruction and respiratory function were improved by the treatment with CHST3 siRNA. CHST3 siRNA reduced the number of macrophages both in BAL and lung parenchyma and also suppressed the increased expressions of TNF-α and MMP-9 mRNA. Futhermore, CHST3 siRNA improved the reduction of the elastin in the alveolar walls.

CONCLUSIONS

CHST3 siRNA diminishes accumulation of excessive macrophages and the mediators, leading to accelerate the functional recovery from airway damage by repair of the elastin network associated with pulmonary emphysema.