Survivin siRNA Research Articles

Delivery of Survivin siRNA Using Cationic Diphenylalanine Vesicles

Small interfering RNA(siRNA) has been proved to be a powerful tool for silencing target gene in cells, raising the possibility that siRNA can be employed as a therapy for treating cancers and other genetic diseases. However, siRNA transfection has the limitation due to the difficulty in the delivery of siRNA to target cells and tissues. To explore an efficient biocompatible siRNA delivery system, cationic diphenylalanine vesicles(CDPVs) were constructed to transfer survivin siRNA to human ovarian cancer cells. The morphology of CDPVs was characterized by scanning electron microscopy(SEM) and the distribution of survivin siRNA was characterized by confocal laser scanning microscopy, which reveal that diphenylalanine and the survivin siRNA were successfully co-delivered. After co-incubation for 48 h, the CDPVs/siRNA exhibited enhanced tumor cell growth inhabitation and apoptosis inducted in human SK-OV-3 ovarian carcinoma cells. Overall, CDPVs is an efficient siRNA delivery system and has a promising prospect for cancer therapy.

Synergistic effects of 7-O-geranylquercetin and siRNAs on the treatment of human breast cancer

AimsTo investigate the antitumor effect of 7-O-geranylquercetin (GQ) combining with survivin siRNA (siSuvi) or IL-10 siRNA (siIL-10) to breast cancer. Main methodsXenograft tumor model was established by subcutaneously inoculating human breast cancer MCF-7 cells in BALB/c nude mice. Transfection efficiency of siRNA mediated by cationic liposome CDO14 in MCF-7 cells and tumor bearing mice was measured by flow cytometer and living imaging sysytem, respectively. Cell viability was detected using CCK-8 assay. Cell apoptosis was determined by Hoechst33342 staining and AV-PI staining. Tumors bearing mice were administered with GQ by gavage, and/or with liposome CDO14 mediated siRNAs via tail intravenous injection. Expression levels of proteins and cytokines were detected by western blot and ELISA, respectively. Key findingsLiposome CDO14 could deliver siRNA to tumor effectively. Combination of GQ and siSuvi promoted the antiproliferation and pro-apoptosis effects of GQ or siSuvi to MCF-7 cells, and reduced the level of survivin and raised the level of caspase-7 in cells. GQ combining with siSuvi inhibited the growth of tumor, down-regulated the expression of survivin and up-regulated the expression of caspase-7 in tumor tissue. Similarly, GQ combining with siIL-10 inhibited the growth of tumor, decreased the level of IL-10 and increased the level of TNF-α. These results revealed that GQ enhanced the pro-apoptosis effect of siSuvi on tumor cells and the modulating effect of siIL-10 on tumor microenvironment. SignificancesSynergistic anti-tumor effect of GQ and siRNAs against breast cancer proved that chemical drugs combining with siRNAs is a promising antitumor strategy.

Cancer-selective nanoparticles for combinatorial siRNA delivery to primary human GBM in vitro and in vivo

Novel treatments for glioblastoma (GBM) are urgently needed, particularly those which can simultaneously target GBM cells’ ability to grow and migrate. Herein, we describe a synthetic, bioreducible, biodegradable polymer that can package and deliver hundreds of siRNA molecules into a single nanoparticle, facilitating combination therapy against multiple GBM-promoting targets. We demonstrate that siRNA delivery with these polymeric nanoparticles is cancer-selective, thereby avoiding potential side effects in healthy cells. We show that we can deliver siRNAs targeting several anti-GBM genes (Robo1, YAP1, NKCC1, EGFR, and survivin) simultaneously and within the same nanoparticles. Robo1 (roundabout homolog 1) siRNA delivery by biodegradable particles was found to trigger GBM cell death, as did non-viral delivery of NKCC1, EGFR, and survivin siRNA. Most importantly, combining several anti-GBM siRNAs into a nanoparticle formulation leads to high GBM cell death, reduces GBM migration in vitro, and reduces tumor burden over time following intratumoral administration. We show that certain genes, like survivin and EGFR, are important for GBM survival, while NKCC1, is more crucial for cancer cell migration. This represents a powerful platform technology with the potential to serve as a multimodal therapeutic for cancer.

Targeted and Efficient Delivery of siRNA Using Tunable Polymeric Hybrid Micelles for Tumor Therapy.

Effective and targeted delivery of siRNA to tumor cells is a prerequisite to achieving their therapeutic effects. Survivin is up-regulated in tumor cells and is associated with resistance to therapy. Therefore, siRNA-mediated silencing of survivin is a potential therapeutic strategy for cancer. The aim of the study was to examine whether polymeric hybrid micelles can be used to effectively deliver siRNAs into cells. First, linoleic acid (LA) was conjugated to polyethylenimine (PEI) and methoxy-polyethyleneglycol (mPEG) and two amphiphilic polymers (PEI-LA and mPEG-LA) were obtained. Polymeric hybrid micelle (PHM) was then prepared and characterized by self-assembly of PEI-LA and mPEG-LA at different percentages of the two amphiphilic polymers. A PHM/siRNA complex with optimized composition and good biocompatibility was then prepared and its cellular uptake, biodistribution, and antitumor effects were investigated. Survivin siRNA was efficiently delivered to the cells. It reduced survivin protein expression and greatly suppressed tumor growth. Moreover, siRNA loaded in PHM gathered in a solid tumor in mice and achieved an improved anticancer effect compared to naked siRNA. PHM is a promising and safe vehicle for siRNA delivery and may find utility in cancer therapy.

Targeted Co-Delivery of siRNA and Methotrexate for Tumor Therapy via Mixed Micelles.

A combination of chemotherapeutic drugs and siRNA is emerging as a new modality for cancer therapy. A safe and effective carrier platform is needed for combination drug delivery. Here, a functionalized mixed micelle-based delivery system was developed for targeted co-delivery of methotrexate (MTX) and survivin siRNA. Linolenic acid (LA) was separately conjugated to branched polyethlenimine (b-PEI) and methoxy-polyethyleneglycol (mPEG). MTX was then conjugated to LA-modified b-PEI (MTX-bPEI-LA) to form a functionalized polymer-drug conjugate. Functionalized mixed micelles (M-MTX) were obtained by the self-assembly of MTX-bPEI-LA and LA-modified mPEG (mPEG-LA). M-MTX had a narrow particle size distribution and could successfully condense siRNA at an N/P ratio of 16/1. M-MTX/siRNA was selectively taken up by HeLa cells overexpressing the folate receptor (FR) and facilitated the release of the siRNA into the cytoplasm. In vitro, M-MTX/siRNA produced a synergy between MTX and survivin siRNA and markedly suppressed survivin protein expression. In tumor-bearing mice, M-MTX/Cy5-siRNA showed an elevated tumor uptake. In addition, M-MTX/siRNA inhibited tumor growth. Immunohistochemistry and a western blot analysis showed a significant target gene downregulation. In conclusion, M-MTX/siRNA was highly effective as a delivery system and may serve as a model for the targeted co-delivery of therapeutic agents.

Enhanced Lysosomal Escape of pH-Responsive Polyethylenimine-Betaine Functionalized Carbon Nanotube for the Codelivery of Survivin Small Interfering RNA and Doxorubicin.

The combination of gene therapy and chemotherapy has recently received considerable attention for cancer treatment. However, low transfection efficiency and poor endosomal escape of genes from nanocarriers strongly limit the success of the clinical use of small interfering RNA (siRNA). In this study, a novel pH-responsive, surface-modified single-walled carbon nanotube (SWCNT) was designed for the codelivery of doxorubicin (DOX) and survivin siRNA. Polyethylenimine (PEI) was covalently conjugated with betaine, and the resulting PEI-betaine (PB) was further synthesized with the oxidized SWCNT to form SWCNT-PB (SPB), which exhibits an excellent pH-responsive lysosomal escape of siRNA. SPB was modified with the targeting and penetrating peptide BR2 (SPBB), thereby achieving considerably higher uptake of siRNA than SWCNT-PEI (SP) or SPB. Furthermore, SPBB-siRNA presented substantially lower survivin expression and higher apoptotic index than Lipofectamine 2000. DOX and survivin siRNA were adsorbed onto SPB to form DOX-SPBB-siRNA, and siRNA/DOX was released into the cytoplasm and nuclei of adenocarcinomic human alveolar basal epithelial (A549) cells without lysosomal retention. Compared with SPBB-siRNA or DOX-SPBB treatment alone, DOX-SPBB-siRNA significantly reduced tumor volume in A549 cell-bearing nude mice, demonstrating the synergistic effects of DOX and survivin siRNA. Pathological analysis also indicated the potential therapeutic effects of DOX-SPBB-siRNA on tumors without distinct damages to normal tissues. In conclusion, the novel functionalized SWCNT loaded with DOX and survivin siRNA was successfully synthesized, and the nanocomplex exhibited effective antitumor effects both in vitro and in vivo, thereby providing an alternative strategy for the codelivery of antitumor drugs and genes.

Active Targeting Co-Delivery of Therapeutic <i>Sur</i> siRNA and Antineoplastic Drug Via Epidermal Growth Factor Receptor Mediated Magnetic Nanoparticles for Synergistic Programmed Cell Death in Glioblastoma Stem Cells

Active targeting co-delivery of therapeutic siRNAs and antineoplastic drugs is considered as a very promising approach in a targeted manner to improve therapeutic effects via simultaneously repressing expression of tumorigenic genes and reducing the systemic toxicity of the anticancer drugs. The development of such strategies that could efficiently target cancer stem cells (CSCs) has gained considerable attention in the therapeutic treatments of human cancers. The objective of this study was to prepare and characterize the therapeutic survivin siRNAs (Sur siRNA) and anti-cancer drug doxorubicin (DOX) loaded superparamagnetic iron oxide nanoparticles (SPIO NPs) that were surface conjugated with the specific ligand to epidermal growth factor receptor (EGFR), highly expressed on brain glioblastoma stem cells (GSCs), using carboxymethyl chitosan (CMCS), polyethylenimine (PEI) and heparin mediated cross linking agents. This prepared EGFR-targeted nanoparticles exhibited excellent targeting specificity and enhanced delivery efficiency, and could specifically co-deliver therapeutic siRNAs and DOX into GSCs, and thus greatly improved the therapeutic efficacy by effectively silencing of survivin gene expression and enhanced the treatment sensitivity of GSCs to anticancer drug DOX. Therefore, these fabricated EGFR-targeted nanoparticles provided an efficient targeted vehicle for co-delivery of therapeutic siRNAs and anticancer drugs, and could serve as a promising active targeting nanocarrier for selective therapeutic treatments of human brain cancer in future.

Proliferation inhibition and apoptosis promotion by dual silencing of VEGF and Survivin in human osteosarcoma.

Simultaneous silencing of multiple upregulated genes is an attractive and viable treatment strategy for many incurable diseases including cancer. Herein we used a dual gene-targeted siRNA conjugate composed of VEGF and Survivin siRNA sequences in the same backbone to inhibit proliferation and angiogenesis in two human osteosarcoma cell lines. We synthesized siRNA sequences targeting the VEGF and Survivin genes individually (VEGF siRNA and Survivin siRNA) or simultaneously (one-chain-double-target siRNA: dual siRNA). VEGF and Survivin mRNA and protein expression levels in human osteosarcoma MG-63 and Saos-2 cells were detected by qRT-PCR and western blot analysis. VEGF and Survivin protein location and expression were evaluated by immunohistochemistry and immunofluorescence staining. MG-63 and Saos-2 cell migration, proliferation, apoptosis, and angiogenesis were detected by scratch test, MTT assay, flow cytometry, and capillary tube assay respectively. The dual siRNA induced similar downregulation of VEGF and Survivin mRNA and protein levels, compared with VEGF siRNA or Survivin siRNA alone. The dual siRNA caused greater suppression of MG-63 and Saos-2 cell migration, proliferation and angiogenesis, and promoted more cell apoptosis than VEGF siRNA or Survivin siRNA alone, suggesting that the effects of the dual siRNA on inhibiting cell proliferation, migration, and angiogenesis and promoting apoptosis were superior to those of the single-target siRNAs. Simultaneous silencing of VEGF and Survivin using the dual siRNA may be an advantageous alternative for the development of therapeutic strategies against human osteosarcoma.

Arrowtail RNA for Ligand Display on Ginger Exosome-like Nanovesicles to Systemic Deliver siRNA for Cancer Suppression

Exosomes have shown increasing potential as delivery vesicles for therapy, but challenges like cost/yield, drug payload, and targeting specificity still exist. Plant derived exosome-like nanoparticles have been reported as a promising substitution and exhibit biocompatibility through oral, intranasal administration; however, systemic delivery of siRNA by exosome-like nanoparticles directly isolated from plants has not been reported. Recently, we reported the control of RNA orientation to decorate human derived exosome with cell targeting ligands for specific delivery of siRNA to tumors. Here, we expand to the application of arrowtail RNA nanoparticles for displaying ligands on ginger derived exosome-like nanovesicles (GDENs) for siRNA delivery and tumor inhibition through IV administration. Cushion ultracentrifugation coupled with equilibrium density gradient ultracentrifugation were used for purifying GDENs that displayed size, density, and morphology similar to human derived exosomes. Folic acid (FA), as a ligand, was displayed on the surface of GDENs for targeted delivery of survivin siRNA to KB cancer models. In vitro gene knockdown efficacy by FA-3WJ/GDENs/siRNA complex was comparable to transfection. We observed inhibition of tumor growth on a xenograft model by intravenous administration, which reveals the potential of GDENs as an economic delivery system for siRNA.

Liposomal codelivery of an SN38 prodrug and a survivin siRNA for tumor therapy.

PurposeA liposome-based siRNA–drug combination was evaluated as a potential therapeutic strategy to improve the curative effect.MethodsA topoisomerase inhibitor SN38 prodrug was combined with a survivin siRNA through codelivery using transferrin (Tf)-L-SN38/P/siRNA. In this combination, SN38 was conjugated to the cell penetrating peptide TAT through a polyethylene glycol (PEG) linker to synthesize TAT-PEG-SN38. The amphiphilic TAT-PEG-SN38 was used as an ingredient of liposomes to improve the cellular uptake. Protamine was added to form an electrostatic complex with siRNA in the core of the liposomes. Tf was introduced to enable tumor cell targeting of liposomes (Tf-L-SN38/P/siRNA).ResultsTf-L-SN38/P/siRNA exhibited a particle size of 148 nm and a ζ-potential of +7.8 mV. The cellular uptake and antitumor activity were dependent on Tf receptor targeting, TAT-PEG-SN38, and siRNA codelivery. Tf-L-SN38/P/siRNA was shown to be considerably more effective than liposomes carrying individual components. This combination induced potent tumor inhibition (76.8%) in HeLa cell xenograft tumor-bearing nude mice.ConclusionThese data indicated that Tf-L-SN38/P/siRNA was an effective system for codelivery of SN38 and a survivin siRNA and that its therapeutic potential deserved further evaluation.

Additive Polyplexes to Undertake siRNA Therapy against CDC20 and Survivin in Breast Cancer Cells.

Small interfering RNA (siRNA) delivered to silence overexpressed genes associated with malignancies is a promising targeted therapy to decrease the uncontrolled growth of malignant cells. To create potent delivery agents for siRNA, here we formulated additive polyplexes of siRNA using linoleic acid-substituted polyethylenimine and additive polymers (hyaluronic acid, poly(acrylic acid), dextran sulfate, and methyl cellulose) and characterized their physicochemical properties and effectiveness. Incorporating polyanionic polymer along with anionic siRNA in polyplexes was found to decrease the ζ-potential of polyplexes but enhance the cellular delivery of siRNA. The CDC20 and survivin siRNAs delivered by additive polyplexes showed promising efficacy in breast cancer MDA-MB-231, SUM149PT, MDA-MB-436, and MCF7 cells. However, the side effects of the siRNA delivery were observed in nonmalignant cells, and a careful formulation of siRNA/polymer polyplexes was needed to minimize side effects on normal cells. Because the efficacy of siRNA delivery by additive polyplexes was independent of breast cancer phenotypes used in this study, these polyplexes could be further developed to treat a wide range of breast cancers.

Effect of small interfering RNA targeting survivin gene on the expression of survivin and biological function of a human cutaneous squamous cell carcinoma cell line A431

Objective To evaluate the effect of small interfering RNA (siRNA) targeting survivin gene on the expression of survivin and proliferation, apoptosis, migration and invasion of a human cutaneous squamous cell carcinoma cell line A431 in vitro. Methods A survivin-specific siRNA was designed and synthesized. Cultured A431 cells were divided into 3 groups to be transfected with 50.0 nmol/L liposome complexes containing survivin-specific siRNA (survivin siRNA group) , 50.0 nmol/L liposome complexes containing unrelated siRNA (negative control group) and 50.0 nmol/L prepared vesicles (blank control group) . Real-time quantitative reverse transcription-PCR (RT-PCR) and Western blot analysis were performed to determine the mRNA and protein expression of survivin in A431 cells, respectively. Methyl thiazolyl tetrazolium (MTT) assay was conducted to evaluate cellular proliferative activity, flow cytometry using annexin-V/propidium iodide (PI) staining to detect cell apoptosis, Transwell assay to estimate migratory and invasive activities of A431 cells, and flow cytometry to detect cell cycle changes. Results At 48 hours after transfection, the mRNA and protein expression of survivin both significantly differed among the survivin siRNA group, negative control group and blank control group (mRNA: 0.56 ± 0.15, 0.88 ± 0.37, 0.90 ± 0.43, F= 276.67, P 0.05) . Repeated measures analysis of variance showed that the transfection with survivin siRNA could significantly inhibit the proliferation of A431 cells (F= 13.19, P= 0.004) , the proliferation inhibition rate was significantly higher in the survivin siRNA group than in the negative control group and blank control group (both P 0.05) . At 24 hours after transfection, the apoptosis rate significantly differed among the 3 groups (F= 83.97, P= 0.002) . The survivin siRNA group showed a significantly higher apoptosis rate compared with the negative control group and blank control group (both P 0.05) . At 48 hours after transfection, the survivin siRNA group showed a significantly higher proportion of cells at G2/M phase, but lower number of migratory cells and invasive cells compared with the negative control group and blank control group (all P < 0.05) . Conclusion Survivin-specific siRNA can inhibit the expression of survivin gene and the proliferation of A431 cells, promote cell apoptosis, and suppress cell migration and invasion, indicating that survivin may serve as a genetic target for the treatment of cutaneous squamous cell carcinoma. Key words: Neoplasms, squamous cell; RNA, small interfering; Cell proliferation; Apoptosis; Cell cycle; Cell movement; Survivin; A431 cells

Smart polymeric nanoparticles with pH-responsive and PEG-detachable properties for co-delivering paclitaxel and survivin siRNA to enhance antitumor outcomes.

BackgroundThe co-delivery of chemotherapeutic agents and small interfering RNA (siRNA) within one cargo can enhance the anticancer outcomes through its synergistic therapeutic effects.Materials and methodsWe prepared smart polymeric nanoparticles (NPs) with pH-responsive and poly(ethylene glycol) (PEG)-detachable properties to systemically co-deliver paclitaxel (PTX) and siRNA against survivin gene for lung cancer therapy. The cationic polyethyleneimine-block-polylactic acid (PEI-PLA) was first synthesized and characterized, with good biocompatibility. PTX was encapsulated into the hydrophobic core of the PEI-PLA polymers by dialysis, and then the survivin siRNA was loaded onto the PTX-loaded NPs (PEI-PLA/PTX) through electrostatic interaction between siRNA and PEI block. Finally, the negatively charged poly(ethylene glycol)-block-poly(L-aspartic acid sodium salt) (PEG-PAsp) was coated onto the surface of NPs by electrostatic interaction to form final smart polymeric NPs with mean particle size of 82.4 nm and zeta potential of 4.1 mV. After uptake of NPs by tumor cells, the PEG-PAsp segments became electrically neutral owing to the lower endosome pH and consequently detached from the smart NPs. This process allowed endosomal escape of the NPs through the proton-sponge effect of the exposed PEI moiety.ResultsThe resulting NPs achieved drug loading of 6.04 wt% and exhibited good dispersibility within 24 h in 10% fetal bovine serum (FBS). At pH 5.5, the NPs presented better drug release and cellular uptake than at pH 7.4. The NPs with survivin siRNA effectively knocked down the expression of survivin mRNA and protein owing to enhanced cell uptake of NPs. Cell counting kit-8 (CCK-8) assay showed that the NPs presented low systemic toxicity and improved antiproliferation effect of PTX on A549 cells. Moreover, in vivo studies demonstrated that accumulated NPs in the tumor site were capable of inhibiting the tumor growth and extending the survival rate of the mice by silencing the survivin gene and delivering PTX into tumor cells simultaneously.ConclusionThese results indicate that the prepared nano-vectors could be a promising co-delivery system for novel chemo/gene combination therapy.

Augmented Anticancer Efficacy by si-RNA Complexed Drug-Loaded Mesoporous Silica Nanoparticles in Lung Cancer Therapy

Lung cancer remains the major cause of death throughout the world. However, with the cutting-edge therapeutic approaches the patient’s survivability remains poor. Nanoparticle-mediated targeted gene therapy has surfaced globally for the therapeutic improvement in cancer patients. Recently, mesoporous silica nanoparticles (MSNs) have attracted much attention for the intracellular delivery of siRNA. Further codelivery strategy has been proposed to minimize the amount of each drug and to achieve the synergistic effect for cancer therapies. In the present investigation we explored the efficacy of codelivery of anticancer drugs along with survivin siRNA in the MSNs for a comparative therapeutic efficacy in lung cancer. Our results revealed such combinational approach has provoked enhanced therapeutic efficacy by synergistic drug activity while restraining the action of survivin protein. Thus, we anticipate this emerging approach may be quite beneficial for lung cancer therapy in future.

SiRNA Delivery Using a Cationic-Lipid-Based Highly Selective Human DNA Ligase I Inhibitor.

The present article illustrates the serendipitous discovery of a cationic-lipid-based human DNA ligase (hLig) I inhibitor and the development of siRNA delivering, a hLigI-targeted cationic-lipid-based nonviral vector. We have tested a small in-house library of structurally similar cationic lipo-anisamides for antiligase activity, and amongst tested, N-dodecyl-N-(2-(4-methoxybenzamido)ethyl)-N-methyldodecan-1-ammonium iodide (C12M) selectively and efficiently inhibited the enzyme activity of hLigI, compared to other human ligases (hLigIIIβ and hLigIV/XRCC4) and bacterial T4 DNA ligase. Furthermore, upon hydration with equimolar cholesterol, C12M produced antiligase cationic liposomes, which transfected survivin siRNA and showed significant inhibition of tumor growth.

Dual-modified cationic liposomes loaded with paclitaxel and survivin siRNA for targeted imaging and therapy of cancer stem cells in brain glioma

Development of safe, efficient nanocomplex for targeted imaging and therapy of cancer stem cells in brain glioma has become a great challenge. Herein, a low-density lipoprotein receptor-related protein and a RNA aptamer bound CD133 were used as dual-targeting ligands to prepare dual-modified cationic liposomes (DP-CLPs) loaded with survivin siRNA and paclitaxel (DP-CLPs–PTX–siRNA) for actively targeting imaging and treating CD133+ glioma stem cells after passing through the blood–brain barrier. After being administrated with DP-CLPs–PTX–siRNA nanocomplex, DP-CLPs showed a persistent target ability to bind glioma cells and brain microvascular endothelial cells (BCECs) and to deliver drugs (PTX/siRNA) to CD133+ glioma stem cells. Prepared DP-CLPs–PTX–siRNA nanocomplex showed very low cytotoxicity to BCECs, but induced selectively apoptosis of CD133+ glioma stem cells, and improved CD133+ glioma stem cells' differentiation into non-stem-cell lineages, also markedly inhibited tumorigenesis, induced CD133+ glioma cell apoptosis in intracranial glioma tumor-bearing nude mice and improved survival rates. In conclusion, prepared DP-CLPs–PTX–siRNA nanocomplex selectively induced CD133+ glioma stem cell apoptosis in vitro and in vivo exhibits great potential for targeted imaging and therapy of brain glioma stem cells.

Nanoparticle orientation to control RNAloading and ligand display on extracellular vesicles for cancer regression.

Nanotechnology holds many advantages. Here we report another advantage of applying RNA nanotechnology for directional control. The orientation of arrow-shaped RNA was altered to control ligand-display on extracellular vesicle (EV) membranes for specific cell targeting, or to regulate intracellular trafficking of siRNA/miRNA. Placing membrane-anchoring cholesterol at the arrow-tail results in display of RNA aptamer or folate on EV outer surface. In contrast, placing the cholesterol at the arrow-head results in partial loading of RNA nanoparticles into the EVs. Taking advantage of the RNA ligand for specific targeting and EVs for efficient membrane fusion, the resulting ligand-displaying EVs were competent for specific delivery of siRNA to cells, and efficiently block tumor growth in three cancer models. PSMA aptamer-displaying EVs loaded with survivin siRNA inhibited prostate cancer xenograft. The same EV but displaying EGFR aptamer inhibited orthotopic breast cancer models. Likewise, survivin-loaded and folate-displaying EVs inhibited patient derived colorectal cancer xenograft.

Enhancement of chemosensitivity by simultaneously silencing of Mcl-1 and Survivin genes using small interfering RNA in human myelomonocytic leukaemia

Acute myeloid leukaemia (AML) is a genetically heterogeneous, severe and rapidly progressing disease triggered by blocking granulocyte or monocyte differentiation and maturation. Overexpression of myeloid cell leukaemia-1 (Mcl-1) and Survivin is associated with drug resistance, tumour progression and inhibition of apoptotic mechanisms in leukaemia and several cancers. In the present study, we examined the combined effect of etoposide and dual siRNA-mediated silencing of Mcl-1 and Survivin on U-937 AML cells. The AML cells were co-transfected with Mcl-1 and Survivin-specific siRNAs and genes silencing were confirmed by quantitative real-time PCR and Western blotting. Subsequently, MTT assay was used for the evaluation of cytotoxic effects by dual siRNA and etoposide on their own and in combination. For the studying of apoptosis, DNA-histone ELISA and annexin-V/FITC assays were performed. Co-transfection of Mcl-1 and Survivin siRNA significantly blocked their expression at the mRNA and protein levels, leading to the induction of apoptosis and strong inhibition of growth (p < .05). Besides, combined treatment of etoposide with Mcl-1 and Survivin siRNAs co-transfection leads to synergistically enhance etoposide-induced cytotoxic and apoptotic effects (p < .05). The results showed that Mcl-1 and Survivin play a major role in the U937 cells survival and their resistance relative to etoposide. Thus, Mcl-1 and Survivin can be considered as promising molecular targets for the treatment of AML. The combination treatment with etoposide, and siRNA-mediated silencing of corresponding genes may be a novel strategy in chemoresistance AML treatment.

GABAB receptor ligand-directed trimethyl chitosan/tripolyphosphate nanoparticles and their pMDI formulation for survivin siRNA pulmonary delivery

The effect of gene silencing by survivin siRNA (siSurvivin) on the proliferation and apoptosis of lung tumor has been attracted more interest. GABAB receptor ligand-directed nanoparticles consisting of baclofen functionalized trimethyl chitosan (Bac-TMC) as polymeric carriers, tripolyphosphate (TPP) as ionic crosslinker, and siSurvivin as therapeutic genes, were designed to enhance the survivin gene silencing. GABAB receptor agonist baclofen (Bac) was initially introduced into TMC as a novel ligand. This Bac-TMC/TPP nanoparticles increased the uptake of survivin siRNA through the interaction with GABAB receptor, further resulted in efficient cell apoptosis and gene silencing. For siRNA-loaded nanoparticles pulmonary delivery, mannitol was utilized for it delivery into pressurized metered dose inhalers (pMDI). The fine particle fractions of this formulation was (45.39±2.99)% indicating the appropriate deep lung deposition. These results revealed that this pMDI formulation containing Bac-TMC/TPP nanoparticles would be a promising siRNA delivery system for lung cancer treatment.

Multifunctional Superparamagnetic Nanoparticles: From Synthesis to siRNA Delivery.

Targeted delivery of small interfering RNA (siRNA) to the specific tumor tissues and cells is the key challenge in the development of RNA interference as a therapeutic application. To target breast cancer, we developed a cationic nanoparticle as a therapeutic delivery system. The successful synthesis of the magnetic nanoparticles modified by polyaspartate (PAA) and polyethyleneimine (PEI) was confirmed using fourier transform infrared (FT-IR) measurements. The designed nanoparticle has been characterized evaluating its size and charge before and after nanoplex formation with siRNA. The designed nanoparticle could effectively form nanoplex with siRNA in 2:1 w/w ratio. Survivin siRNA was used to suppress the antiapoptotic gene, survivin, in MCF-7 cells. According to the importance of combinational therapy, Mitoxantrone (MTX) was used as a chemotherapeutic agent as well. The multifunctional nanoparticles have been successfully entered into about 63% of the MCF-7 cells shown via microscopic and flowcytometric methods. This effective cellular uptake led to the cell apoptosis. Down regulation of survivin was determined in mRNA and protein levels using Real Time PCR and western blotting, respectively. Gathering all obtained data, it was concluded that Fe3O4-PAA-PEI nanoparticles can deliver siRNA effectively into the cytoplasm of the MCF-7 breast cancer cells and induce apoptosis.