Nutlin3a-Loaded Nanoparticles Show Enhanced Apoptotic Activity on Prostate Cancer Cells

Microfluidic Fabricated Liposomes for Nutlin-3a Ocular Delivery as Potential Candidate for Proliferative Vitreoretinal Diseases Treatment

Purpose

Proliferative vitreoretinal diseases (PVDs) represent a heterogeneous group of pathologies characterized by the presence of retinal proliferative membranes, in whose development retinal pigment epithelium (RPE) is deeply involved. As the only effective treatment for PVDs at present is surgery, we aimed to investigate the potential therapeutic activity of Nutlin-3a, a small non-genotoxic inhibitor of the MDM2/p53 interaction, on ARPE-19 cell line and on human RPE primary cells, as in vitro models of RPE and, more importantly, to formulate and evaluate Nutlin-3a loaded liposomes designed for ophthalmic administration.

Methods

Liposomes were produced using an innovative approach by a microfluidic device under selection of different conditions. Liposome size distribution was evaluated by photon correlation spectroscopy and centrifugal field flow fractionation, while the liposome structure was studied by transmission electron microscopy and Fourier-transform infrared spectroscopy. The Nutlin-3a entrapment capacity was evaluated by ultrafiltration and HPLC. Nutlin-3a biological effectiveness as a solution or loaded in liposomes was evaluated by viability, proliferation, apoptosis and migration assays and by morphological analysis.

Results

The microfluidic formulative study enabled the selection of liposomes composed of phosphatidylcholine (PC) 5.4 or 8.2 mg/mL and 10% ethanol, characterized by roundish vesicular structures with 150-250 nm mean diameters. Particularly, liposomes based on the lower PC concentration were characterized by higher stability. Nutlin-3a was effectively encapsulated in liposomes and was able to induce a significant reduction of viability and migration in RPE cell models.

Conclusion

Our results lay the basis for a possible use of liposomes for the ocular delivery of Nutlin-3a.

Cationic solid lipid nanoparticles (SLN) complexed with plasmid DNA enhance prostate cancer cells (PC-3) migration

Nanotechnology applications in biomedicine have increased in recent decades, primarily as therapeutic agents, drugs, and gene delivery systems. Among the nanoparticles used in medicine, we highlight cationic solid lipid nanoparticles (SLN). Given their nontoxic properties, much research has focused on the beneficial effects of SLN for drug or gene delivery system. However, little attention has been paid to the adverse impacts of SLN on the cellular environment, particularly their influence on intracellular signaling pathways. In this work, we investigate the effects triggered by cationic SLN on human prostate non-tumor cells (PNT1A) and tumor cells (PC-3). Our results demonstrate that cationic SLN enhances the migration of PC-3 prostate cancer cells but not PNT1A non-tumor prostate cells, an unexpected and unprecedented development. Furthermore, we observed that the enhanced cell migration velocity is a concentration-dependent and nanoparticle-dependent effect, and not related to any individual nanoparticle component. Moreover, cationic SLN increased vimentin expression (p < 0.05) but SLN did not affect Smad2 nuclear translocation. Meanwhile, EMT-related (epithelial-to-mesenchymal transition) proteins, such as ZEB1, underwent nuclear translocation when treated with cationic SLN, thereby affecting PC-3 cell motility through ZEB1 and vimentin modulation. From a therapeutic perspective, cationic SLN could potentially worsen a patient's condition if these results were reproduced in vivo. Understanding the in vitro molecular mechanisms triggered by nanomaterials and their implications for cell function is crucial for defining their safe and effective use.

Nutlin-3 Loaded Ethosomes and Transethosomes to Prevent UV-Associated Skin Damage

The skin's protective mechanisms, in some cases, are not able to counteract the destructive effects induced by UV radiations, resulting in dermatological diseases, as well as skin aging. Nutlin-3, a potent drug with antiproliferative activity in keratinocytes, can block UV-induced apoptosis by activation of p53. In the present investigation, ethosomes and transethosomes were designed as delivery systems for nutlin-3, with the aim to protect the skin against UV damage. Vesicle size distribution was evaluated by photon correlation spectroscopy and morphology was investigated by cryogenic transmission electron microscopy, while nutlin-3 entrapment capacity was evaluated by ultrafiltration and HPLC. The in vitro diffusion kinetic of nutlin-3 from ethosomes and transethosomes was studied by Franz cell. Moreover, the efficiency of ethosomes and transethosomes in delivering nutlin-3 and its protective role were evaluated in ex vivo skin explants exposed to UV radiations. The results indicate that ethosomes and transethosomes efficaciously entrapped nutlin-3 (0.3% w/w). The ethosome vesicles were spherical and oligolamellar, with a 224 nm mean diameter, while in transethosome the presence of polysorbate 80 resulted in unilamellar vesicles with a 146 nm mean diameter. The fastest nutlin-3 kinetic was detected in the case of transethosomes, with permeability coefficients 7.4-fold higher, with respect to ethosomes and diffusion values 250-fold higher, with respect to the drug in solution. Ex vivo data suggest a better efficacy of transethosomes to promote nutlin-3 delivery within the skin, with respect to ethosomes. Indeed, nutlin-3 loaded transethosomes could prevent UV effect on cutaneous metalloproteinase activation and cell proliferative response.

Brain-targeted, drug-loaded solid lipid nanoparticles against glioblastoma cells in culture

The aim of this study was the preparation of solid lipid nanoparticles (SLN) formed from cetyl palmitate with having targeting molecules for monocarboxylate transporter-1 (MCT-1): β-hydroxybutyric acid and anticancer agents: carmustine (BCNU) and temozolomide (TMZ) for enhanced anti-proliferation against glioblastoma multiforme (GBM). Properties including size, morphology, chemical structure, zeta potential, drug encapsulation efficacy, drug release, biocompatibility, stability were determined, and in vitro studies were done. BCNU and TMZ loaded SLNs had a hydrodynamic size of 227 nm ± 46 a zeta potential of -25 mV ± 4 with biocompatible features. The data showed rapid drug release at first and then continuous release. Nanoparticles could be stored for nine months. BCNU and TMZ loaded SLNs exhibited a remarkable increment in the antitumor activity compared to the free-drugs and induced apoptosis on U87MG cells. In addition, targeted nanoparticles were more uptaken by MCT-1 expressing brain cells. This study indicated that BCNU and TMZ loaded SLNs could act as a useful anticancer system for targeted GBM therapy.

Androgen Receptor-Dependent Mechanisms Mediating Drug Resistance in Prostate Cancer

Androgen receptor (AR) is a main driver of prostate cancer (PCa) growth and progression as well as the key drug target. Appropriate PCa treatments differ depending on the stage of cancer at diagnosis. Although androgen deprivation therapy (ADT) of PCa is initially effective, eventually tumors develop resistance to the drug within 2-3 years of treatment onset leading to castration resistant PCa (CRPC). Castration resistance is usually mediated by reactivation of AR signaling. Eventually, PCa develops additional resistance towards treatment with AR antagonists that occur regularly, also mostly due to bypass mechanisms that activate AR signaling. This tumor evolution with selection upon therapy is presumably based on a high degree of tumor heterogenicity and plasticity that allows PCa cells to proliferate and develop adaptive signaling to the treatment and evolve pathways in therapy resistance, including resistance to chemotherapy. The therapy-resistant PCa phenotype is associated with more aggressiveness and increased metastatic ability. By far, drug resistance remains a major cause of PCa treatment failure and lethality. In this review, various acquired and intrinsic mechanisms that are AR‑dependent and contribute to PCa drug resistance will be discussed.

Honokiol inhibits the growth of SKBR3 cells

BACKGROUND

Breast cancer is one of the most malignant tumors in the reproductive system and has a poor prognosis. Finding drugs with high efficiency, low side-effects, and low cost has become a research hotspot.

METHODS

In the present study, we treated SK-BR-3 cells with different doses of honokiol. Crystal violet staining method was used to detect changes in the total number of living cells; 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was used to detect the effect of honokiol on SK-BR-3 cell proliferation. Cell migration ability change was determined by wound healing assay. Cell invasion ability change was determined by Transwell migration assay. Flow cytometry was used to detect the apoptotic rate of SK-BR-3 cells, and Western blot was used to detect the expression levels of proliferation-associated protein (PCNA); migration- and invasion-related protein matrix metalloproteinase-2 (MMP-2); vimentin; apoptosis-related proteins Bcl-xl, caspase 3, and cleaved caspase 3 (CC3); and β-catenin and its downstream target molecule c-Myc.

RESULTS

Compared with the control group, different doses of honokiol have different degrees of inhibitory effects on cells, including proliferation and invasion and migration (P<0.01). After treatment with 50 or 60 µmol·L-1 honokiol, the apoptotic rate of SK-BR-3 cells increased (both P<0.01); PCNA expression was significantly downregulated (P<0.01). Intracellular accumulation of apoptosis-related proteins Bcl-xl and caspase-3 decreased but C-C3 increased. We also found downregulation of MMP-2 expression, a protein related to invasion and migration (P<0.01), and a decrease in the expression levels of the Wnt/β-catenin signaling pathway-related proteins β-catenin and c-Myc (P<0.01).

CONCLUSIONS

Honokiol can promote the apoptosis of SK-BR-3 cells and can inhibit the proliferation, migration, and invasion of human breast cancer SK-BR-3 cells. The underlying mechanism may be through inhibiting the activation of the Wnt signaling pathway.

Surface-functionalised hybrid nanoparticles for targeted treatment of cancer

Cancer is a leading cause of death worldwide. Despite the great advancement in understanding the pharmacology and biology of cancer, it still signifies one of the most serious human-health related problems. The current treatments for cancer may include surgery, radiotherapy, and chemotherapy, but these procedures have several limitations. Current studies have shown that nanoparticles (NPs) can be used as a novel strategy for cancer treatment. Developing nanosystems that allow lower doses of therapeutic agents, as well as their selective release in tumour cells, may resolve the challenges of targeted cancer therapy. In this review, the authors discuss the role of the size, shape, and surface modifications of NPs in cancer treatment. They also address the challenges associated with cancer therapies based on NPs. The overall purpose of this review is to summarise the recent developments in designing different hybrid NPs with promising therapeutic properties for different types of cancer.