Silencing β3 Integrin by Targeted ECO/siRNA Nanoparticles Inhibits EMT and Metastasis of Triple-Negative Breast Cancer

Targeted Multifunctional Lipid ECO Plasmid DNA Nanoparticles as Efficient Non-viral Gene Therapy for Leber's Congenital Amaurosis

Development of a gene delivery system with high efficiency and a good safety profile is essential for successful gene therapy. Here we developed a targeted non-viral delivery system using a multifunctional lipid ECO for treating Leber’s congenital amaurosis type 2 (LCA2) and tested this in a mouse model. ECO formed stable nanoparticles with plasmid DNA (pDNA) at a low amine to phosphate (N/P) ratio and mediated high gene transfection efficiency in ARPE-19 cells because of their intrinsic properties of pH-sensitive amphiphilic endosomal escape and reductive cytosolic release (PERC). All-trans-retinylamine, which binds to interphotoreceptor retinoid-binding protein (IRBP), was incorporated into the nanoparticles via a polyethylene glycol (PEG) spacer for targeted delivery of pDNA into the retinal pigmented epithelium. The targeted ECO/pDNA nanoparticles provided high GFP expression in the RPE of 1-month-old Rpe65^−/− mice after subretinal injection. Such mice also exhibited a significant increase in electroretinographic activity, and this therapeutic effect continued for at least 120 days. A safety study in wild-type BALB/c mice indicated no irreversible retinal damage following subretinal injection of these targeted nanoparticles. All-trans-retinylamine-modified ECO/pDNA nanoparticles provide a promising non-viral platform for safe and effective treatment of RPE-specific monogenic eye diseases such as LCA2.

TGFΒ-induced transcription in cancer

The Transforming Growth Factor-beta (TGFβ) pathway mediates a broad spectrum of cellular processes and is involved in several diseases, including cancer. TGFβ has a dual role in tumours, acting as a tumour suppressor in the early phase of tumorigenesis and as a tumour promoter in more advanced stages. In this review, we discuss the effects of TGFβ-driven transcription on all stages of tumour progression, with special focus on lung cancer. Since some TGFβ target genes are specifically involved in promoting metastasis, we speculate that these genes might be good targets to block tumour progression without compromising the tumour suppressor effects of the TGFβ pathway.

Suppression of the Growth and Invasion of Human Head and Neck Squamous Cell Carcinomas via Regulating STAT3 Signaling and the miR-21/β-catenin Axis with HJC0152

Signal transducer and activator of transcription 3 (STAT3) is involved in the tumor growth and metastasis of human head and neck squamous cell carcinoma (HNSCC) and is therefore a target with therapeutic potential. In this study, we show that HJC0152, a recently developed anticancer agent and a STAT3 signaling inhibitor, exhibits promising antitumor effects against HNSCC both in vitro and in vivo via inactivating STAT3 and downstream miR-21/β-catenin axis. HJC0152 treatment efficiently suppressed HNSCC cell proliferation, arrested the cell cycle at the G₀-G₁ phase, induced apoptosis, and reduced cell invasion in both SCC25 and CAL27 cell lines. Moreover, HJC0152 inhibited nuclear translocation of phosphorylated STAT3 at Tyr705 and decreased VHL/β-catenin signaling activity via regulation of miR-21. Loss of function of VHL remarkably compromised the antitumor effect of HJC0152 in both cell lines. In our SCC25-derived orthotopic mouse models, HJC0152 treatment significantly abrogated STAT3/β-catenin expression in vivo, leading to a global decrease of tumor growth and invasion. With its favorable aqueous solubility and oral bioavailability, HJC0152 holds the potential to be translated into the clinic as a promising therapeutic strategy for patients with HNSCC. Mol Cancer Ther; 16(4); 578-90. ©2017 AACR.

Gold nanorod embedded large-pore mesoporous organosilica nanospheres for gene and photothermal cooperative therapy of triple negative breast cancer

To date, clinicians still lack an effective strategy to treat triple negative breast cancer (TNBC). In this work, we design for the first time a gold nanorod embedded large-pore mesoporous organosilica (GNR@LPMO) nanoplatform for gene and photothermal cooperative therapy of TNBC. The synthesized GNR@LPMOs possess a uniform size (175 nm), high surface area (631 m2 g-1), large pore size, excellent photothermal efficiency, and good biocompatibility. Thanks to the large-pore mesoporous organosilica layer, the GNR@LPMO nanoplatforms display much higher loading capacity of siRNA compared with traditional liposome and bare gold nanorods. Thus, functional siRNA can be efficiently delivered into TNBC cells by GNR@LPMOs, causing much higher cell apoptosis through knocking down the PLK1 proteins. By combining the effective gene delivery and photothermal abilities, the GNR@LPMO nanoplatforms are further used for gene and photothermal cooperative therapy of TNBC, which induce a 15 fold higher mice tumor inhibition rate than sole therapy modality, indicating the potential clinical use of this novel nanoplatform in treating TNBC.

HMGA2-FOXL2 Axis Regulates Metastases and Epithelial-to-Mesenchymal Transition of Chemoresistant Gastric Cancer

Purpose: Chemoresistance is the main cause of treatment failure in cancer and is associated with distant metastases and epithelial-to-mesenchymal transition (EMT). This study was aimed to explore the mechanism of metastases and EMT in chemoresistant gastric cancer.Experimental Design: A key molecular pathway was identified via gene profiling and a bioinformatic analysis in a chemoresistant gastric cancer model. The roles of FOXL2, HMGA2, and ITGA2 were validated via loss-of-function and gain-of-function experiments in vitro and in an orthotopic gastric cancer animal model. The regulation of FOXL2 by HMGA2 was explored via immunoprecipitation and luciferase reporter assays. The expression of these proteins in gastric cancer tissues was examined by IHC.Results: HMGA2 and FOXL2 directly regulated the metastasis and EMT of chemoresistant gastric cancer. The interaction between HMGA2 and pRb facilitated the transactivation of FOXL2 by E2F1, and ITGA2 was the downstream effector of the HMGA2-FOXL2 pathway. HMGA2, FOXL2, and ITGA2 were associated with the TNM classification and staging of gastric cancer and were increased in metastatic lymph nodes and distant metastases. Increased HMGA2, FOXL2, and ITGA2 levels were associated with reduced overall survival periods of patients with gastric cancer.Conclusions: This study demonstrated that the transactivation of FOXL2 driven by interactions between HMGA2 and pRb might exert critical effects on the metastases and EMT of chemoresistant gastric cancer. Blocking the HMGA2-FOXL2-ITGA2 pathway could serve as a new strategy for gastric cancer treatment. Clin Cancer Res; 23(13); 3461-73. ©2017 AACR.

Current Challenges toward In Vitro Cellular Validation of Inorganic Nanoparticles

An impressive development has been achieved toward the production of well-defined "smart" inorganic nanoparticles, in which the physicochemical properties can be controlled and predicted to a high degree of accuracy. Nanoparticle design is indeed highly advanced, multimodal and multitargeting being the norm, yet we do not fully understand the obstacles that nanoparticles face when used in vivo. Increased cooperation between chemists and biochemists, immunologists and physicists, has allowed us to think outside the box, and we are slowly starting to understand the interactions that nanoparticles undergo under more realistic situations. Importantly, such an understanding involves awareness about the limitations when assessing the influence of such inorganic nanoparticles on biological entities and vice versa, as well as the development of new validation strategies.

Long noncoding RNA linc-ITGB1 promotes cell migration and invasion in human breast cancer

Breast cancer is the most commonly diagnosed cancer and the leading cause of cancer-related death in women globally. Its high morbidity and mortality, as well as its elevated tendency to metastasize to other organs, warrant the urgency to find new biomarkers for breast cancer diagnosis and treatment. The specific roles of long noncoding RNA linc-ITGB1 on cell proliferation and metastasis in breast cancer were explored in this study. The expression of linc-ITGB1 was significantly upregulated in both clinical breast cancer tissues and cultured breast cancer cell lines. The linc-ITGB1 knockdown with specific short hairpin RNA (shRNA) decreased cell proliferation and colony formation in vitro. Tumor growth in vivo was also inhibited by linc-ITGB1 depletion. In addition, linc-ITGB1 depletion caused cell accumulation in the G0/G1 phase. Breast cancer cell lines with linc-ITGB1 depletion exhibited decreased migration and invasion abilities compared with the control cells. Furthermore, the linc-ITGB1 knockdown decreased the expression of mesenchymal markers N-cadherin and vimentin while increasing the expression of the epithelial marker E-cadherin. Key cell cycle regulators Cdc25C and Cyclin B1 were also decreased by the linc-ITGB1 knockdown. These data suggest that linc-ITGB1 promotes breast cancer progression by inducing cell cycle arrest and interrupting the epithelial-to-mesenchymal transition process.

Nanoparticles for imaging and treatment of metastatic breast cancer

INTRODUCTION

Metastatic breast cancer is one of the most devastating cancers that have no cure. Many therapeutic and diagnostic strategies have been extensively studied in the past decade. Among these strategies, cancer nanotechnology has emerged as a promising strategy in preclinical studies by enabling early identification of primary tumors and metastases, and by effective killing of cancer cells. Areas covered: This review covers the recent progress made in targeting and imaging of metastatic breast cancer with nanoparticles, and treatment using nanoparticle-enabled chemo-, gene, photothermal- and radio-therapies. This review also discusses recent developments of nanoparticle-enabled stem cell therapy and immunotherapy. Expert opinion: Nanotechnology is expected to play important roles in modern therapy for cancers, including metastatic breast cancer. Nanoparticles are able to target and visualize metastasis in various organs, and deliver therapeutic agents. Through targeting cancer stem cells, nanoparticles are able to treat resistant tumors with minimal toxicity to healthy tissues/organs. Nanoparticles are also able to activate immune cells to eliminate tumors. Owing to their multifunctional, controllable and trackable features, nanotechnology-based imaging and therapy could be a highly potent approach for future cancer research and treatment.

Biodegradable nanoparticles as siRNA carriers for in vivo gene silencing and pancreatic cancer therapy

Biodegradable charged polyester-based vectors (BCPVs) were utilized for efficiently delivering mutatedK-Ras-targeting siRNA and successfully inhibiting tumor growth in a pancreatic xenograft modelin vivo.

Targeted Dual pH-Sensitive Lipid ECO/siRNA Self-Assembly Nanoparticles Facilitate In Vivo Cytosolic sieIF4E Delivery and Overcome Paclitaxel Resistance in Breast Cancer Therapy

RNAi-mediated knockdown of oncogenes associated with drug resistance can potentially enhance the efficacy of chemotherapy. Here, we have designed and developed targeted dual pH-sensitive lipid-siRNA self-assembly nanoparticles, RGD-PEG(HZ)-ECO/siRNA, which can efficiently silence the oncogene, eukaryotic translation initiation factor 4E (eIF4E), and consequently resensitize triple-negative breast tumors to paclitaxel. The dual pH-sensitive function of these nanoparticles facilitates effective cytosolic siRNA delivery in cancer cells, both in vitro and in vivo. Intravenous injection of RGD-PEG(HZ)-ECO/siRNA nanoparticles (1.0 mg-siRNA/kg) results in effective gene silencing for at least one week in MDA-MB-231 tumors. In addition, treatment of athymic nude mice with RGD-PEG(HZ)-ECO/sieIF4E every 6 days for 6 weeks down-regulates the overexpression of eIF4E and resensitizes paclitaxel-resistant MDA-MB-231 tumors to paclitaxel, resulting in significant tumor regression at a low dose, with negligible side effects. Moreover, repeated injections of the RGD-PEG(HZ)-ECO/siRNA nanoparticles in immunocompetent mice result in minimal immunogenicity, demonstrating their safety and low toxicity. These multifunctional lipid/siRNA nanoparticles constitute a versatile platform of delivery of therapeutic siRNA for treating cancer and other human diseases.

Biomaterials for Abrogating Metastasis: Bridging the Gap between Basic and Translational Research

Herein lies the issue of how to best approach cancer metastasis therapeutics in a focused, directed and efficacious manner. The lack of standardized means to efficiently deliver therapeutic cargo to metastatic sites calls for a paradigm shift in the way we view and treat metastasis. It is crucial to leverage the potential of nanomedicine to differentially combat cancer spread at each stage of the disease (primary tumor growth and formation of metastases) while considering the optimal administration route. We propose to implement three possible strategies to treat cancer as a function of disease type and state, while leveraging the advancement in materials design and in particular nanotechnology: (1) local primary tumor abrogation; (2) primary tumor re-programming to prevent metastasis; and (3) combination (local and systemic) therapy when metastasis has already transpired. Herein, we highlight potential means to bridge the gap between basic and translational research as related to metastasis therapy.

Oligonucleotide-based theranostic nanoparticles in cancer therapy

Theranostic approaches, combining the functionality of both therapy and imaging, have shown potential in cancer nanomedicine. Oligonucleotides such as small interfering RNA and microRNA, which are powerful therapeutic agents, have been effectively employed in theranostic systems against various cancers. Nanoparticles are used to deliver oligonucleotides into tumors by passive or active targeting while protecting the oligonucleotides from nucleases in the extracellular environment. The use of quantum dots, iron oxide nanoparticles and gold nanoparticles and tagging with contrast agents, like fluorescent dyes, optical or magnetic agents and various radioisotopes, has facilitated early detection of tumors and evaluation of therapeutic efficacy. In this article, we review the advantages of theranostic applications in cancer therapy and imaging, with special attention to oligonucleotide-based therapeutics.

Drug Delivery Using Nanoparticles for Cancer Stem-Like Cell Targeting

The theory of cancer stem-like cell (or cancer stem cell, CSC) has been established to explain how tumor heterogeneity arises and contributes to tumor progression in diverse cancer types. CSCs are believed to drive tumor growth and elicit resistance to conventional therapeutics. Therefore, CSCs are becoming novel target in both medical researches and clinical studies. Emerging evidences showed that nanoparticles effectively inhibit many types of CSCs by targeting various specific markers (aldehyde dehydrogenases, CD44, CD90, and CD133) and signaling pathways (Notch, Hedgehog, and TGF-β), which are critically involved in CSC function and maintenance. In this review, we briefly summarize the current status of CSC research and review a number of state-of-the-art nanomedicine approaches targeting CSC. In addition, we discuss emerging therapeutic strategies using epigenetic drugs to eliminate CSCs and inhibit cancer cell reprogramming.

RNA nanomedicines: the next generation drugs?

RNA therapeutics could represent the next generation personalized medicine. The variety of RNA molecules that can inhibit the expression of any mRNA using, for example, RNA interference (RNAi) strategies, or increase the expression of a given protein using modified mRNA together with new gene editing strategies open new avenues for manipulating the fate of diseased cells while leaving healthy cells untouched. In addition, these therapeutic RNA molecules can maximize the treatment of diseases and minimize its adverse effects. Yet, the promise of RNA therapeutics is hindered by the lack of efficient delivery strategies to selectively target these molecules into specific cells. Herein, we will focus on the challenges and opportunities of the delivery of therapeutic RNAi molecules into cancer cells with special emphasis on solid tumors. Solid tumors represent more than 80 percent of cancers and some are very challenging to treat, not merely due to physiological barriers but also since the tumor microenvironment (TME) is a complex milieu of accessory cells besides the cancerous cells. In this review, we will highlight various limiting factors to successful delivery, current clinical achievements and future outlook focusing on RNAi therapeutics to the TME.

Downregulation of β3 integrin by miR-30a-5p modulates cell adhesion and invasion by interrupting Erk/Ets‑1 network in triple-negative breast cancer

Integrins are adhesion receptors involved in bidirectional signaling and are crucial for various cellular responses during normal homeostasis and pathological conditions, such as cancer progression and metastasis. In the present study, we demonstrated that blockage of β3 integrin-mediated cell- extracellular matrix interactions restrained triple-negative breast cancer (TNBC) growth, and elevated β3 integrin can trigger the rewiring of Erk/Ets-1 signaling pathways, thereby enhancing cell growth and invasion. Ectopic expression of miRNA has been implicated in the deregulation of integrin expression and activity, blocking of cancer tumor development and progression, and acquisition of metastatic phenotype. miR-30a-5p expression has been implicated in the progression of breast cancer. Overexpression of miR-30a-5p suppressed the proliferation, migration and invasion of breast cancer cells. On the contrary, inhibition of miR-30a-5p promoted the proliferation, migration, and invasion of TNBC cells by suppressing the expression of ERK/Ets-1 signal. An inverse correlation was found between the mRNA expressions of miR-30a-5p and β3 integrin in TNBC samples. Furthermore, bioinformatics analysis revealed the putative miR-30 binding sites in the 3'-UTR of β3 integrin. Results of luciferase assay revealed a strong repression of luciferase activity after transfection with miR‑30a-5p and wild-type 3'-UTR of β3 integrin. In TNBC cells, miR-30a-5p promoted an epithelial phenotype and suppressed invasion by specifically targeting β3 integrin subunit to subsequently interdict the β3 integrin/Erk/Ets-1 network.

Multifunctional pH-Sensitive Amino Lipids for siRNA Delivery

RNA interference (RNAi) represents a powerful modality for human disease therapy that can regulate gene expression signature using small interfering RNA (siRNA). Successful delivery of siRNA into the cytoplasm of target cells is imperative for efficient RNAi and also constitutes the primary stumbling block in the clinical applicability of RNAi. Significant progress has been made in the development of lipid-based siRNA delivery systems, which have practical advantages like simple chemistry and easy formulation of nanoparticles with siRNA. This review discusses the recent development of pH-sensitive amino lipids, with particular focus on multifunctional pH-sensitive amino lipids for siRNA delivery. The key components of these multifunctional lipids include a protonatable amino head group, distal lipid tails, and two cross-linkable thiol groups, which together facilitate the facile formation of stable siRNA-nanoparticles, easy surface modification for target-specific delivery, endosomal escape in response to the pH decrease during subcellular trafficking, and reductive dissociation of the siRNA-nanoparticles for cytoplasmic release of free siRNA. By virtue of these properties, multifunctional pH-sensitive lipids can mediate efficient cytosolic siRNA delivery and gene silencing. Targeted siRNA nanoparticles can be readily formulated with these lipids, without the need for other helper lipids, to promote systemic delivery of therapeutic siRNAs. Such targeted siRNA nanoparticles have been shown to effectively regulate the expression of cancer-related genes, resulting in significant efficacy in the treatment of aggressive tumors, including metastatic triple negative breast cancer. These multifunctional pH-sensitive lipids constitute a promising platform for the systemic and targeted delivery of therapeutic siRNA for the treatment of human diseases. This review summarizes the structure-property relationship of the multifunctional pH-sensitive lipids and their efficacy in in vitro and in vivo siRNA delivery and gene silencing.

Self-Assembly of a Multifunctional Lipid With Core-Shell Dendrimer DNA Nanoparticles Enhanced Efficient Gene Delivery at Low Charge Ratios into RPE Cells

Development of safe and effective gene delivery systems is essential in treating ocular genetic disorders. A hybrid nonviral system composed of a multifunctional lipid ECO and a G4 nanoglobule was designed for efficient gene delivery into RPE cells at low charge ratios. This system formed stable DNA nanoparticles at low N/P ratios, exhibited low cytotoxicity, and induced higher GFP expression in ARPE-19 cells at N/P = 6. The hybrid nanoparticles mediated significant reporter gene GFP expression ex-vivo in the retina from wild type C57 mice and in vivo in BALB/c mice. These hybrid nanoparticles are promising for in vitro and in vivo gene delivery at low charge ratios.

MRI detection of breast cancer micrometastases with a fibronectin-targeting contrast agent

Metastasis is the primary cause of death in breast cancer patients. Early detection of high-risk breast cancer, including micrometastasis, is critical in tailoring appropriate and effective interventional therapies. Increased fibronectin expression, a hallmark of epithelial-to-mesenchymal transition, is associated with high-risk breast cancer and metastasis. We have previously developed a penta-peptide CREKA (Cys-Arg-Glu-Lys-Ala)-targeted gadolinium-based magnetic resonance imaging (MRI) contrast agent, CREKA-Tris(Gd-DOTA)3 (Gd-DOTA (4,7,10-tris(carboxymethyl)-1,4,7,10-tetraazacyclododecyl gadolinium), which binds to fibrin-fibronectin complexes that are abundant in the tumour microenvironment of fast-growing breast cancer. Here we assess the capability of CREKA-Tris(Gd-DOTA)3 to detect micrometastasis with MRI in co-registration with high-resolution fluorescence cryo-imaging in female mice bearing metastatic 4T1 breast tumours. We find that CREKA-Tris(Gd-DOTA)3 provides robust contrast enhancement in the metastatic tumours and enables the detection of micrometastases of size <0.5 mm, extending the detection limit of the current clinical imaging modalities. These results demonstrate that molecular MRI with CREKA-Tris(Gd-DOTA)3 may facilitate early detection of high-risk breast cancer and micrometastasis in the clinic.

Targeting delivery and deep penetration using multistage nanoparticles for triple-negative breast cancer

Targeting delivery and size-induced deep penetration have been applied in triple-negative breast cancer (TNBC) theranostics.