A strategy using mesoporous polymer nanospheres as nanocarriers of Bcl-2 siRNA towards breast cancer therapy

Current Advancements in Self-assembling Nanocarriers-Based siRNA Delivery for Cancer Therapy

Different therapeutic practices for treating cancers have significantly evolved to compensate and/or overcome the failures in conventional methodologies. The demonstrated potentiality in completely inhibiting the tumors and in preventing cancer relapse has made nucleic acids therapy (NAT)/gene therapy as an attractive practice. This has been made possible because NAT-based cancer treatments are highly focused on the fundamental mechanisms - i.e., silencing the expression of oncogenic genes responsible for producing abnormal proteins (via messenger RNAs (mRNAs)). However, the future clinical translation of NAT is majorly dependent upon the effective delivery of the exogenous nucleic acids (especially RNAs - e.g., short interfering RNAs (siRNAs) - herein called biological drugs). Moreover, nano-based vehicles (i.e., nanocarriers) are involved in delivering them to prevent degradation and undesired bioaccumulation while enhancing the stability of siRNAs. Herein, we have initially discussed about three major types of self-assembling nanocarriers (liposomes, polymeric nanoparticles and exosomes). Later, we have majorly reviewed recent developments in non-targeted/targeted nanocarriers for delivery of biological drugs (individual/dual) to silence the most important genes/mRNAs accountable for inducing protein abnormality. These proteins include polo-like kinase 1 (PLK1), survivin, vascular endothelial growth factor (VEGF), B-cell lymphoma/leukaemia-2 (Bcl-2) and multi-drug resistance (MDR). Besides, the consequent therapeutic effects on cancer growth, invasion and/or metastasis have also been discussed. Finally, we have comprehensively reviewed the improvements achieved in the cutting-edge cancer therapeutics while delivering siRNAs in combination with clinically approved chemotherapeutic drugs.

Therapeutic Silencing of BCL-2 Using NK Cell-Derived Exosomes as a Novel Therapeutic Approach in Breast Cancer

Simple Summary

Overexpression of the antiapoptotic protein BCL-2 is correlated with estrogen receptor (ER) expression in breast cancer and plays an important role for disease pathophysiology. Here, we conceptualized a novel treatment strategy by targeting ER⁺ breast cancer with NK cell-derived exosomes used as a carrier for BCL-2 targeted siRNAs. With this new approach, we successfully enhanced killing ability of NK cell derived exosomes by silencing of BCL-2 overexpression.

Abstract

Overexpression of the anti-apoptotic protein BCL-2 is frequently observed in multiple malignancies, including about 85% of patients with estrogen receptor positive (ER⁺) breast cancer. Besides being studied as a prognostic marker, BCL-2 is investigated as a therapeutic target in ER⁺ breast cancer. Here, we introduce a new exosome-based strategy to target BCL-2 using genetically modified natural killer (NK) cells. The NK cell line NK92MI was lentivirally transduced to express and load BCL-2 siRNAs (siBCL-2) into exosomes (NKExos) and then evaluated for its potential to treat ER⁺ breast cancer. Transfected NK92MI cells produced substantial levels of BCL-2 siRNAs, without substantially affecting NK cell viability or effector function and led to loading of siBCL-2 in NKExos. Remarkably, targeting BCL-2 via siBCL-2 NKExos led to enhanced intrinsic apoptosis in breast cancer cells, without affecting non-malignant cells. Together, our prototypical results for BCL-2 in breast cancer provide proof of concept for a novel strategy to utilize NKExos as a natural delivery vector for siRNA targeting of oncogenes.

Enhanced siRNA Delivery and Selective Apoptosis Induction in H1299 Cancer Cells by Layer-by-Layer-Assembled Se Nanocomplexes: Toward More Efficient Cancer Therapy

Nanotechnology has made an important contribution to oncology in recent years, especially for drug delivery. While many different nano-delivery systems have been suggested for cancer therapy, selenium nanoparticles (SeNPs) are particularly promising anticancer drug carriers as their core material offers interesting synergistic effects to cancer cells. Se compounds can exert cytotoxic effects by acting as pro-oxidants that alter cellular redox homeostasis, eventually leading to apoptosis induction in many kinds of cancer cells. Herein, we report on the design and synthesis of novel layer-by-layer Se-based nanocomplexes (LBL-Se-NCs) as carriers of small interfering RNA (siRNA) for combined gene silencing and apoptosis induction in cancer cells. The LBL-Se-NCs were prepared using a straightforward electrostatic assembly of siRNA and chitosan (CS) on the solid core of the SeNP. In this study, we started by investigating the colloidal stability and protection of the complexed siRNA. The results show that CS not only functioned as an anchoring layer for siRNA, but also provided colloidal stability for at least 20 days in different media when CS was applied as a third layer. The release study revealed that siRNA remained better associated with LBL-Se-NCs, with only a release of 35% after 7 days, as compared to CS-NCs with a siRNA release of 100% after 48 h, making the LBL nanocarrier an excellent candidate as an off-the-shelf formulation. When applied to H1299 cells, it was found that they can selectively induce around 32% apoptosis, while significantly less apoptosis (5.6%) was induced in NIH/3T3 normal cells. At the same time, they were capable of efficiently inducing siRNA downregulation (35%) without loss of activity 7 days post-synthesis. We conclude that LBL-Se-NCs are promising siRNA carriers with enhanced stability and with a dual mode of action against cancer cells.

Folate Receptor-Mediated siRNA Delivery: Recent Developments and Future Directions for RNAi Therapeutics

RNA interference (RNAi), a gene regulatory process mediated by small interfering RNAs (siRNAs), has made remarkable progress as a potential therapeutic agent against various diseases. However, RNAi is associated with fundamental challenges such as poor systemic delivery and susceptibility to the nucleases. Targeting ligand-bound delivery vehicles has improved the accumulation of drug at the target site, which has resulted in high transfection efficiency and enhanced gene silencing. Recently, folate receptor (FR)-mediated targeted delivery of siRNAs has garnered attention due to their enhanced cellular uptake and high transfection efficiency toward tumor cells. Folic acid (FA), due to its small size, low immunogenicity, high in vivo stability, and high binding affinity toward FRs, has attracted much attention for targeted siRNA delivery. FRs are overexpressed in a large number of tumors, including ovarian, breast, kidney, and lung cancer cells. In this review, we discuss recent advances in FA-mediated siRNA delivery to treat cancers and inflammatory diseases. This review summarizes various FA-conjugated nanoparticle systems reported so far in the literature, including liposome, silica, metal, graphene, dendrimers, chitosan, organic copolymers, and RNA nanoparticles. This review will help in the design and development of potential delivery vehicles for siRNA drug targeting to tumor cells using an FR-mediated approach.

Effects of near-far acupuncture on neuronal function and expression of apoptosis-related protein Bax/Bcl-2/Cleaved caspase-3 in rats with ischemic stroke

Objectives To explore the effects of electroacupuncture on nerve function in rats with ischemic stroke and its mechanism of anti-apoptosis. Methods A total of 80 SPF male SD rats were randomly divided into sham operation group, model group, sham electroacupuncture group, acupuncture group, electroacupuncture group and 16 rats in each group. The rat model of left ischemic stroke was prepared by suture embolization. In the sham group, the left common carotid artery was isolated only and no other treatment was given. In the electroacupuncture group, "Baihui" and "Mingmen" were selected for acupuncture, followed by dilatation wave, frequency 2Hz/100Hz, intensity 1mA, and electroacupuncture for 30min. The sham electroacupuncture group was the same as the electroacupuncture group in acupoint electroacupuncture group was the same as the electroacupuncture group in acupoint selection. The electroacupuncture group was only inserted subcutaneously and then connected with the electroacupuncture group without power supply, and fixed for 30 minutes. The electroacupuncture group and the acupuncture group received electroacupuncture treatment once, for a total of 14 days, 1d after modeling. The Improved Neurological Impairment scale (mNSS) was used to evaluate the degree of neurological impairment in each group after anesthesia and wakefulness. The percentage of cerebral infarction area was determined by TTC staining. HE staining and Nissl staining were used to observe the pathological changes of ischemic brain tissue. The level of apoptosis in ischemic brain tissue was detected by TUNEL assay. Western blot was used to detect protein expression of Bax, Bcl-2 and Cleaved caspase-3 in ischemic brain tissue. Results Compared with the sham operation group, neurological function score, percentage of cerebral infarction area and apoptosis level in the model group were significantly increased (all P < 0.01). Compared with the model group, neurological function score, percentage of cerebral infarction area and apoptosis index of acupuncture group and electroacupuncture group were decreased (all P <0.05). Compared with the model group, the expression levels of Bcl-2 protein in ischemic brain tissue of rats with ischemic stroke were up-regulated in the acupuncture group and electroacupuncture group to different degrees, while the expression levels of Bax and Cleaved caspase-3 protein were down-regulated in the electroacupuncture group. Conclusion Electroacupuncture may inhibit Bax, Cleaved caspase-3 and up-regulate the expression of Bcl-2 against neuronal apoptosis, thereby improving the neurological function injury of ischemic stroke rats.

Nanomedicines for Subcellular Targeting: The Mitochondrial Perspective

BACKGROUND

Over the past decade, there has been a surge in the number of mitochondrialactive therapeutics for conditions ranging from cancer to aging. Subcellular targeting interventions can modulate adverse intracellular processes unique to the compartments within the cell. However, there is a dearth of reviews focusing on mitochondrial nano-delivery, and this review seeks to fill this gap with regards to nanotherapeutics of the mitochondria.

METHODS

Besides its potential for a higher therapeutic index than targeting at the tissue and cell levels, subcellular targeting takes into account the limitations of systemic drug administration and significantly improves pharmacokinetics. Hence, an extensive literature review was undertaken and salient information was compiled in this review.

RESULTS

From literature, it was evident that nanoparticles with their tunable physicochemical properties have shown potential for efficient therapeutic delivery, with several nanomedicines already approved by the FDA and others in clinical trials. However, strategies for the development of nanomedicines for subcellular targeting are still emerging, with an increased understanding of dysfunctional molecular processes advancing the development of treatment modules. For optimal delivery, the design of an ideal carrier for subcellular delivery must consider the features of the diseased microenvironment. The functional and structural features of the mitochondria in the diseased state are highlighted and potential nano-delivery interventions for treatment and diagnosis are discussed.

CONCLUSION

This review provides an insight into recent advances in subcellular targeting, with a focus on en route barriers to subcellular targeting. The impact of mitochondrial dysfunction in the aetiology of certain diseases is highlighted, and potential therapeutic sites are identified.

Nanomedicine in treatment of breast cancer - A challenge to conventional therapy

Amongst the various types of cancer, breast cancer is a highly heterogeneous disease and known as the leading cause of death among women globally. The extensive interdisciplinary investigation in nanotechnology and cancer biomedical research has been evolved over the years for its effective treatment. However, the advent of chemotherapeutic resistance in breast cancer is one of the major confront researchers are facing in achieving successful chemotherapy. Research in the area of cancer nanotechnology over the years have now been revolutionized through the development of smart polymers, lipids, inorganic materials and eventually their surface-engineering with targeting ligands. Moreover, nanotechnology further extended and brings in the notice the new theranostic approach which combining the therapy and imaging simultaneously. Currently, research is being envisaged in the area of novel nano-pharmaceutical design viz. liposome, nanotubes, polymer lipid hybrid system, which focuses to make the chemotherapy curative and long-lasting. In this review, we aimed to discuss the recent advancement of different surface-engineered/targeted nanomedicines that improved the drug efficacy in breast cancer.

Nanoparticle-delivered siRNA targeting Bruton's tyrosine kinase for rheumatoid arthritis therapy

Rheumatoid arthritis (RA) is a systemic autoimmune disease that can cause irreversible joint deformity. There is still no cure for RA, and current therapeutics, including methotrexate and adalimumab, cause serious off-target effects and systemic immunosuppression, which in turn increases the risk of infection. Bruton's tyrosine kinase (BTK) in macrophages and B cells has been demonstrated to be a promising therapeutic target for RA. However, high doses of BTK inhibitors are required for efficient BTK suppression, which limits their clinical use. Small interfering RNA (siRNA) is promising for the silencing of specific genes and has been used for the treatment of multiple diseases. To deliver siRNA into macrophages and B cells for BTK gene silencing, we employed cationic lipid-assisted PEG-b-PLGA nanoparticles (CLANs) to encapsulate siRNA. We demonstrated that macrophages and B cells were able to efficiently ingest the CLANs both in vitro and in vivo. Thereafter, we encapsulated siRNA targeting BTK (siBTK) into the CLANs, denoted as CLAN_siBTK, and demonstrated that CLAN_siBTK significantly inhibited BTK expression in macrophages and B cells. In a collagen-induced mouse arthritis model, CLAN_siBTK treatment dramatically reduced joint inflammation and other RA symptoms but showed no toxicity, proving that using CLAN_siBTK is a promising approach for RA therapy.