Surmounting tumor resistance to metallodrugs by co-loading a metal complex and siRNA in nanoparticles

Apoferritin-Cu(II) Nanoparticles Induce Oncosis in Multidrug-Resistant Colon Cancer Cells

Multidrug resistance (MDR) limits the application of clinical chemotherapeutic drugs. There is an urgent need to develop non-apoptosis-inducing agents that circumvent drug resistance. Herein, four therapeutic copper complexes encapsulated in natural nanocarrier apoferritin (AFt-Cu1-4) are reported. Although they are isomers, they exhibit significantly different organelle distributions and cell death mechanisms. AFt-Cu1 and AFt-Cu3 accumulate in the cytoplasm and induce autophagy, whereas AFt-Cu2 and AFt-Cu4 can quickly enter the nucleus and trigger oncosis. Excitedly, AFt-Cu2 and AFt-Cu4 show a strong tumor growth inhibition effect in mice models bearing multidrug-resistant colon xenograft via intravenous injection. To the best of the authors' knowledge, this is the first example of metal-based nucleus-targeted oncosis inducers overcoming multidrug resistance in vivo.

Autophagy and cancer drug resistance in dialogue: Pre-clinical and clinical evidence

The emergence of drug resistance is a major challenge for oncologists. Resistance can be categorized as acquired or intrinsic; the alteration of several biological mechanisms contributes to both intrinsic and acquired resistance. Macroautophagy/autophagy is the primary process in eukaryotes for the degradation of macromolecules and organelles. This process is critical in maintaining cellular homeostasis. Given its function as either a pro-survival or a pro-death phenomenon, autophagy has a complex physio-pathological role. In some circumstances, autophagy can confer chemoresistance and promote cell survival, whereas in others it can promote chemosensitivity and contribute to cell death. The role of autophagy in the modulation of cancer drug resistance reflects its impact on apoptosis and metastasis. The regulation of autophagy in cancer is mediated by various factors including AMP-activated protein kinase (AMPK), MAPK, phosphoinositide 3-kinase (PI3K)-AKT, BECN1 and ATG proteins. Non-coding RNAs are among the main regulators of autophagy, e.g., via the modulation of chemoresistance pathways. Due to the significant contribution of autophagy in cancer drug resistance, small molecule modulators and natural compounds targeting autophagy have been introduced to alter the response of cancer cells to chemotherapy. Furthermore, nanotherapeutic approaches based on autophagy regulation have been introduced in pre-clinical cancer therapy. In this review we consider the potential for using autophagy regulators for the clinical treatment of malignancies.

Copper in cancer: From pathogenesis to therapy

One of the basic trace elements for the structure and metabolism of human tissue is copper. However, as a heavy metal, excessive intake or abnormal accumulation of copper in the body can cause inevitable damage to the organism because copper can result in direct injury to various cell components or disruption of the redox balance, eventually leading to cell death. Interestingly, a growing body of research reports that diverse cancers have raised serum and tumor copper levels. Tumor cells depend on more copper for their metabolism than normal cells, and a decrease in copper or copper overload can have a detrimental effect on tumor cells. New modalities for identifying and characterizing copper-dependent signals offer translational opportunities for tumor therapy, but their mechanisms remain unclear. Therefore, this article summarizes what we currently know about the correlation between copper and cancer and describes the characteristics of copper metabolism in tumor cells and the prospective application of copper-derived therapeutics.

Target-mediated self-assembly of DNA networks for sensitive detection and intracellular imaging of APE1 in living cells

Herein, giant DNA networks were assembled from two kinds of functionalized tetrahedral DNA nanostructures (f-TDNs) for sensitive detection and intracellular imaging of apurinic/apyrimidinic endonuclease 1 (APE1) as well as gene therapy in tumor cells. Impressively, the reaction rate of the catalytic hairpin assembly (CHA) reaction on f-TDNs was much faster than that of the conventional free CHA reaction owing to the high local concentration of hairpins, spatial confinement effect and production of giant DNA networks, which significantly enhanced the fluorescence signal to achieve sensitive detection of APE1 with a limit of 3.34 × 10^-8 U μL^-1. More importantly, the aptamer Sgc8 assembled on f-TDNs could enhance the targeting activity of the DNA structure to tumor cells, allowing it to endocytose into cells without any transfection reagents, which could achieve selective imaging of intracellular APE1 in living cells. Meanwhile, the siRNA carried by f-TDN1 could be accurately released to promote tumor cell apoptosis in the presence of endogenous target APE1, realizing effective and precise tumor therapy. Benefiting from the high specificity and sensitivity, the developed DNA nanostructures provide an excellent nanoplatform for precise cancer diagnosis and therapy.

Nanocarriers for delivery of siRNA as gene silencing mediator

The term nanocarrier refers to sub-micrometric particles of less than 100 nm, designed to transport, distribute, and release nanotechnology-based drug delivery systems. siRNA therapy is a novel strategy that has great utility for a variety of treatments, however naked siRNA delivery has not been an effective strategy, resulting in the necessary use of nanocarriers for delivery. This review aims to highlight the versatility of carriers based on smart drug delivery systems. The nanocarriers based on nanoparticles as siRNA DDS have provided a set of very attractive advantages related to improved physicochemical properties, such as high surface-to-volume ratio, versatility to package siRNA, provide a dual function to both protect extracellular barriers that lead to elimination and overcome intracellular barriers limiting cytosolic delivery, and possible chemical modifications on the nanoparticle surface to improve stability and targeting. Lipid and polymeric nanocarriers have proven to be stable, biocompatible, and effective in vitro, further exploration of the development of new nanocarriers is needed to obtain safe and biocompatible tools for effective therapy.

Ambient synthesis of an iminium-linked covalent organic framework for synergetic RNA interference and metabolic therapy of fibrosarcoma

Small interfering RNA (siRNA)-mediated gene silencing is a promising therapeutic approach. Herein, we report the ambient synthesis of a positively charged iminium-linked covalent organic framework by a three-component one-pot reaction. Through anion exchange and siRNA adsorption, the resulting multifunctional siRNA@ABMBP-COF, which possesses both the HK2 inhibitor 3-bromopyruvate and SLC7A11 siRNA, exhibits powerful synergistic antitumor activity against fibrosarcoma via the ferroptosis and apoptosis pathways.

Metallodrugs in cancer nanomedicine

Metal complexes are extensively used for cancer therapy. The multiple variables available for tuning (metal, ligand, and metal-ligand interaction) offer unique opportunities for drug design, and have led to a vast portfolio of metallodrugs that can display a higher diversity of functions and mechanisms of action with respect to pure organic structures. Clinically approved metallodrugs, such as cisplatin, carboplatin and oxaliplatin, are used to treat many types of cancer and play prominent roles in combination regimens, including with immunotherapy. However, metallodrugs generally suffer from poor pharmacokinetics, low levels of target site accumulation, metal-mediated off-target reactivity and development of drug resistance, which can all limit their efficacy and clinical translation. Nanomedicine has arisen as a powerful tool to help overcome these shortcomings. Several nanoformulations have already significantly improved the efficacy and reduced the toxicity of (chemo-)therapeutic drugs, including some promising metallodrug-containing nanomedicines currently in clinical trials. In this critical review, we analyse the opportunities and clinical challenges of metallodrugs, and we assess the advantages and limitations of metallodrug delivery, both from a nanocarrier and from a metal-nano interaction perspective. We describe the latest and most relevant nanomedicine formulations developed for metal complexes, and we discuss how the rational combination of coordination chemistry with nanomedicine technology can assist in promoting the clinical translation of metallodrugs.

Loss of JNK-Associated Leucine Zipper Protein Promotes Peritoneal Dialysis-Related Peritoneal Fibrosis

BACKGROUND

Peritoneal dialysis-related peritoneal fibrosis is the leading cause of peritoneal ultrafiltration failure. Multitude factors and pathological processes have been implicated in peritoneal fibrosis development and progression, whereas the intrinsic anti-fibrotic mechanism has rarely been explored. JNK-associated leucine zipper protein (JLP) has been recently found possessing powerful anti-fibrotic merits of overall antagonizing TGF-β-induced profibrotic effects.

OBJECTIVES

We wondered whether JLP is expressed in the peritoneum, and if so, whether it exerts the anti-fibrotic effects similar to those in the kidney.

METHOD

Here, we examined and confirmed JLP expression in peritoneum tissue of mice. Then, we established a peritoneal fibrosis model in Jlp wild-type and Jlp global deficient mice and observed the different effects of Jlp on peritoneal fibrosis progression. In vitro studies were performed on peritoneal mesothelial HMrSV5 cells with or without Jlp knockdown to investigate the underlying mechanism by which Jlp exerts anti-fibrotic effects.

RESULTS

We found that the expression of JLP decreased in a high-glucose peritoneal dialysis solution (HGPDS)-induced peritoneal fibrosis mouse model and in HGPDS-treated peritoneal mesothelial cell HMrSV5. JLP deletion exacerbated HGPDS-induced peritoneal fibrosis in peritoneal fibrosis mice, and knockdown of JLP resulted in an increased profibrotic response to HGPDS stimulation in HMrSV5 cells, which was associated with epithelial-to-mesenchymal transition, elevated autophagy, and apoptosis, as well as enhanced TGF-β1/Smad signaling activation.

CONCLUSIONS

Our findings revealed a new anti-fibrotic factor of Jlp involved in peritoneal fibrosis induction and shed light on novel therapeutic targets in peritoneal ultrafiltration failure.

Self-assembly of DNA Nanogels with Endogenous MicroRNA Toehold Self-regulating Switches for Targeted Gene Regulation Therapy

Herein, a smart nanohydrogel with endogenous microRNA-21 toehold is developed to encapsulate gemcitabine-loaded mesoporous silica nanoparticles for targeted pancreatic cancer therapy. This toehold mediated strand displacement method can simultaneously achieve...

Nanotechnology lights up the antitumor potency by combining chemotherapy with siRNA

Nanotechnology-based combination anticancer therapy offers novel approaches to overcome the limitations of single-agent administration. The emerging siRNA technology combined with chemotherapy has shown considerable promise in anticancer therapy. There are three main challenges in the fabrication of siRNA/chemotherapeutic drug co-loaded nanovectors: adequate cargo protection, precise targeted delivery, and site-specific cargo release. This review presents a summary of the nanosystems that have recently been developed for co-delivering siRNA and chemotherapeutic drugs. Their combined therapeutic effects are also discussed.