Tissue distribution of 2-methoxyestradiol nanosuspension in rats and its antitumor activity in C57BL/6 mice bearing lewis lung carcinoma

Self-reporting photodynamic nanobody conjugate for precise and sustainable large-volume tumor treatment

Nanobodies (Nbs), the smallest antigen-binding fragments with high stability and affinity derived from the variable domain of naturally occurring heavy-chain-only antibodies in camelids, have been shown as an efficient way to improve the specificity to tumors for photodynamic therapy (PDT). Nonetheless, the rapid clearance of Nbs in vivo restricts the accumulation and retention of the photosensitizer at the tumor site causing insufficient therapeutic outcome, especially in large-volume tumors. Herein, we develop photodynamic conjugates, MNB-Pyra Nbs, through site-specific conjugation between 7D12 Nbs and type I photosensitizer MNB-Pyra (morpholine-modified nile blue structure connected to pyrazolinone) in a 1:2 ratio. The photosensitizers with long-term retention can be released at the tumor site by reactive oxygen species cleavage after illumination, accompanied with fluorescence recovery for self-reporting the occurrence of PDT. Ultimately, a single dose of MNB-Pyra Nbs demonstrate highly effective tumor suppression with high biosafety in the large-volume tumor models after three rounds of PDT. This nanobody conjugate provides a paradigm for the design of precise long-time retention photosensitizers and is expected to promote the development of PDT.

Self-Nanoemulsifying Drug Delivery System of 2-Methoxyestradiol Exhibits Enhanced Anti-Proliferative and Pro-Apoptotic Activities in MCF-7 Breast Cancer Cells

(1) Background: 2-Methoxyestradiol (2ME) is a metabolite of estrogens and possesses promising anti-proliferative and cytotoxic activities. However, it suffers unfavorable pharmacokinetic characteristics such as absorption after oral administration. The aim of this study was to prepare an optimized 2ME self-nanoemulsifying drug delivery system (2ME-SNEDDS) and evaluate its cytotoxicity and pro-apoptotic activities in MCF-7 breast cancer cells. (2) Methods: For optimization of the 2ME-SNEDDS, a three-component system was used in the D-optimal mixture experimental study. MCF-7 cells were incubated with the 2ME-SNEDDS and subjected to an assessment of growth inhibition, cell cycle progression, annexin V staining, caspase-3 concentration, Bax, Bcl-2, and cyclin D1 mRNA expression, and reactive oxygen species (ROS) generation. (3) Results: The optimized formula had a globule size of 94.97 ± 4.35 nm. Zeta potential was found to be −3.4 ± 1.2 mV with a polydispersity index (PDI) of 0.34. In addition, 96.3  ± 4.3% of 2ME was released from the 2ME-SNEDDS within 24 h using the activated analysis bag technique. Moreover, the prepared 2ME-SNEDDS exhibited a significant enhancement of the anti-proliferative activity against MCF-7 cells in comparison to raw 2ME. This was associated with cyclin D1 expression down-regulation and the accumulation of cells in the G0/G1 and G2/M phases. The pro-apoptotic activities of the 2ME-SNEDDS were confirmed by annexin V staining, which indicated enhanced early and late cell death. This accompanied modulation of the mRNA expression of Bax and Bcl-2 in favor of apoptosis. The 2ME-SNEDDS significantly enhanced cleaved caspase-3 concentration in comparison to raw 2ME. In addition, the 2ME-SNEDDS significantly increased the generation of ROS in MCF-7 cells. (4) Conclusions: The 2ME-SNEDDS exhibits enhanced cytotoxicity and pro-apoptotic activity in MCF-7 cells. This is mediated by, at least partially, ROS generation.

Induction of 2-hydroxycatecholestrogens O-methylation: A missing puzzle piece in diagnostics and treatment of lung cancer

Lung cancer is one of the most common cancers worldwide, causing nearly one million deaths each year. Herein, we present the effect of 2-methoxyestradiol (2-ME), the endogenous metabolite of 17β-estradiol (E2), on non-small cell lung cancer (NSCLC) cells. We observed that 2-ME reduced the viability of lung adenocarcinoma in two-dimensional (2D) and three-dimensional (3D) spheroidal A549 cell culture models. Molecular modeling was carried out aiming to visualize amino acid residues within binding pockets of the acyl-protein thioesterases, namely 1 (APT1) and 2 (APT2), and thus to identify which ones were more likely involved in the interaction with 2-ME. Our findings suggest that 2-ME acts as an APT1 inhibitor enhancing protein palmitoylation and oxidative stress phenomena in the lung cancer cell. In order to support our data, metabolomics of blood serum from NSCLC patients was also performed. Moreover, computational analysis suggests that 2-ME as compared to other estrogen metabolism intermediates is relatively safe in terms of its possible non-receptor bioactivity within healthy human cells due to a very low electrophilic potential and hence no substantial risk of spontaneous covalent modification of biologically protective nucleophiles. We propose that 2-ME can be used as a selective tumor biomarker in the course of certain types of lung cancers and possibly as a therapeutic adjuvant or neoadjuvant.

Polygonatum sibiricum polysaccharides play anti-cancer effect through TLR4-MAPK/NF-κB signaling pathways

OBJECTIVE

To investigate the anti-cancer effect of Polygonatum sibiricum polysaccharides (PSP) and the underlying mechanism.

METHODS

Tumor-bearing mice were randomly divided into normal saline (NS) group, adriamycin (ADM) group, PSP group and lipopolysaccharide (LPS) group. RAW264.7 cells were pre-treated with or without TLR4 inhibitor or MyD88 inhibitor. Quantitative RT-PCR and Western blot were performed to detect the mRNA and protein expressions, respectively. ELISA and Griess reaction was used to measure cytokines and NO levels. Flow cytometry was employed to examine T-lymphocyte subset and CCK-8 assay was used for cell viability.

RESULTS

The in vivo experiment found that PSP inhibited tumor growth and improved the spleen index, thymus index, the cytokines secretion and CD4⁺/CD8⁺ lymphocytes ratio. Compared with the NS group, the mRNA and protein expressions of the critical nodes inTLR4-MAPK/NF-κB signaling pathways (except TRAM) significantly increased in PSP group, as well as the NO and cytokines levels. Nevertheless, PSP had no obvious effects on TRAM. Further analysis showed that PSP effects on the critical nodes in TLR4-MAPK/NF-κB signaling pathways were suppressed by inhibitor in vitro.

CONCLUSION

The immunoenhancement effect of PSP against lung cancer is mediated by TLR4-MAPK/NF-κB signaling pathways.

Microtubule targeted therapeutics loaded polymeric assembled nanospheres for potentiation of antineoplastic activity

Polymeric nanoassemblies represent an attractive strategy for efficient cellular internalization of microtubule targeted anticancer drugs. Using dynamic light scattering, zeta potential, transmission electron microscopy and scanning electron microscopy, the physical properties and surface morphology of microtubule-binding PEGylated PLGA assembled nanospheres (100–200 nm) were analyzed. The present approach leads to strong internalization as observed by confocal laser scanning microscopy and transmission electron microscopy in hepatocarcinoma cells. The effect of these nanoassemblies on microtubules and mitosis were explored using immunofluorescence microscopy. The effects of these nanoassemblies on cancer cell proliferation and cell death revealed their antitumor enhancing effects. Perturbation of the microtubule assembly, mitosis and nuclear modulations potentiated the antineoplastic effects delivered via nanospheres in hepatocarcinoma cells. The extensive biomolecular and physical characterizations of the synthesized nanoassemblies will help to design potent therapeutic materials and the present approach can be applied to deliver microtubule-targeted drugs for liver cancer therapy.

Neuronal Nitric Oxide Synthase-Mediated Genotoxicity of 2-Methoxyestradiol in Hippocampal HT22 Cell Line

2-methoxyestradiol, metabolite of 17β-estradiol, is considered a potential anticancer agent, currently investigated in several clinical trials. This natural compound was found to be effective towards great number of cancers, including colon, breast, lung, and osteosarcoma and has been reported to be relatively non-toxic towards non-malignant cells. The aim of the study was to determine the potential neurotoxicity and genotoxicity of 2-methoxyestradiol at physiological and pharmacological relevant concentrations in hippocampal HT22 cell line. Herein, we determined influence of 2-methoxyestradiol on proliferation, inhibition of cell cycle, induction of apoptosis, and DNA damage in the HT22 cells. The study was performed using imaging cytometry and comet assay techniques. Herein, we demonstrated that 2-methoxyestradiol, at pharmacologically and also physiologically relevant concentrations, increases nuclear localization of neuronal nitric oxide synthase. It potentially results in DNA strand breaks and increases in genomic instability in hippocampal HT22 cell line. Thus, we are postulating that naturally occurring 2-methoxyestradiol may be considered a physiological modulator of neuron survival.

DNA strand breaks induced by nuclear hijacking of neuronal NOS as an anti-cancer effect of 2-methoxyestradiol

2-Methoxyestradiol (2-ME) is a physiological metabolite of 17β-estradiol. At pharmacological concentrations, 2-ME inhibits colon, breast and lung cancer in tumor models. Here we investigated the effect of physiologically relevant concentrations of 2-ME in osteosarcoma cell model. We demonstrated that 2-ME increased nuclear localization of neuronal nitric oxide synthase, resulting in nitro-oxidative DNA damage. This in turn caused cell cycle arrest and apoptosis in osteosarcoma cells. We suggest that 2-ME is a naturally occurring hormone with potential anti-cancer properties.

Stability of nanosuspensions in drug delivery

Nanosuspensions are nanosized colloidal dispersion systems that are stabilized by surfactants and/or polymers. Because nanosizing results in the creation of new interfaces and in a positive Gibbs free energy change, nanosuspensions are thermodynamically unstable systems with a tendency toward agglomeration or crystal growth. Despite extensive research on nanosuspension technology, stability remains a limitation for pharmaceutical or industrial applications of nanosuspensions. Furthermore, the empirical relationship between stabilizer efficacy and nanosuspension stability has not been well characterized. This review focuses on the issue of nanosuspension stability in drug delivery to present the state of the art of nanosuspensions. Therefore, this review will discuss unstable suspensions, methods and guidelines for selecting and optimizing stabilizers, approaches for enhancing stability, and other factors that influence nanosuspension stability. This review could serve as a reference for the educated selection of a stabilizer for a specific drug candidate and the optimization of the operational parameters for nanosuspension formulation, rather than the currently practiced trial-and-error approach.