Folate-conjugated immunoglobulin targets melanoma tumor cells for NK cell effector functions

Melanoma-targeted photodynamic therapy based on hypericin-loaded multifunctional P123-spermine/folate micelles

Multifunctional P123 micelle linked covalently with spermine (SM) and folic acid (FA) was developed as a drug delivery system of hypericin (HYP). The chemical structures of the modified copolymers were confirmed by spectroscopy and spectrophotometric techniques (UV-vis, FTIR, and ¹H NMR). The copolymeric micelles loading HYP were prepared by solid dispersion and characterized by UV-vis, fluorescence, dynamic light scattering (DLS), ζ potential, and transmission electron microscopy (TEM). The results provided a good level of stability for HYP-loaded P123-SM, P123-FA, and P123-SM/P123-FA in the aqueous medium. The morphology analysis showed that all copolymeric micelles are spherical. Well-defined regions of different contrast allow us to infer that SM and FA were localized on the surface of micelles, and the HYP molecules are located in the core region of micelles. The uptake potential of multifunctional P123 micelle was accessed by exposing the micellar systems loading HYP to two cell lines, B16-F10 and HaCaT. HYP-loaded P123 micelles reveal a low selectivity for melanoma cells, showing significant photodamage for HaCat cells. However, the exposition of B16-F10 cells to Hyp-loaded SM- and FA-functionalized P123 micelles under light irradiation revealed the lowest CC₅₀ values. The interpretation of these results suggested that the combination of SM and FA on P123 micelles is the main factor in enhancing the HYP uptake by melanoma cells, consequently leading to its photoinactivation.

A review on liposome-based therapeutic approaches against malignant melanoma

Melanoma is a highly aggressive form of skin cancer with a very poor prognosis and excessive resistance to current conventional treatments. Recently, the application of the liposomal delivery system in the management of skin melanoma has been widely investigated. Liposomal nanocarriers are biocompatible and less toxic to host cells, enabling the efficient and safe delivery of different therapeutic agents into the tumor site and further promoting their antitumor activities. Therefore, the liposomal delivery system effectively increases the success of current melanoma therapies and overcomes resistance. In this review, we present an overview of liposome-based targeted drug delivery methods and highlight recent advances towards the development of liposome-based carriers for therapeutic genes. We also discuss the new insights regarding the efficacy and clinical significance of combinatorial treatment of liposomal formulations with immunotherapy and conventional therapies in melanoma patients for a better understanding and successfully managing cancer.

Folate-conjugated Helix lucorum hemocyanin - preparation, stability, and cytotoxicity

This is the first report on the modification of a hemocyanin from Helix lucorum (HlH), a large molluscan respiratory protein, with folic acid (FA). In a two-step synthetic reaction, we prepared samples of HlH conjugated with 20 and 50 FA residues denoted as FA-HlH-1 and FA-HlH-2, respectively. Comparison of the attenuated total reflectance-Fourier transform infrared spectra in the amide I band region showed a structural rearrangement in the HlH that is due to FA conjugation. The changes in the secondary structure were more noticeable for FA-HlH-2. The thermal stability of HlH was not significantly affected by the FA modification, which is consistent with the observed structural similarities with the native protein. Preliminary cytotoxicity assays showed that FA-HlH-1 and FA-HlH-2 stimulate fibroblast proliferation when applied in concentrations of 50 and 100 μg/well. A negligible reduction of fibroblast growth was observed only for FA-HlH-1 and FA-HlH-2, exposed to 200 μg/well for 48 h. We found that FA-HlH-2 exhibits a low to moderate cytotoxic effect on two breast cancer cell lines, which express folate receptors, a hormone-dependent (MCF-7) and a hormone-independent (MDA-MB-231). FA-HlH-2 protects nontransformed cells and affects only neoplastic cells, which could be an advantage, and the protein could have potential in combination with other chemotherapeutics.

Effect of targeted gold nanoparticles size on acoustic cavitation: An in vitro study on melanoma cells

When a liquid is irradiated with high intensities of ultrasound irradiation, acoustic cavitation occurs. Since cavitation can be fatal to cells, it is utilized to destroy cancer tumors. Considering cavitation onset and bubbles collapse, the required ultrasonic intensity threshold can be significantly decreased in the presence of nanoparticles in a liquid. The effects of gold nanoparticles size on acoustic cavitation were investigated in this in vitro study. For this purpose, ultrasonic waves were used at intensities of 0.5, 1 and 2 W/cm² and frequency of 1 MHz in the presence of F-Cys-GNPs with 15, 23 and 79 nm sizes and different concentrations (0.2, 1 and 5 µg/ml) in order to determine their effects on the viability of melanoma cells. This was performed at different incubation times 12, 24 and 36 h. The viability of melanoma cells decreased at higher concentrations and sizes of F-Cys-GNPs. The lowest viability of melanoma cells was seen in those containing 79, 23, and 15 nm F-Cys-GNPs. This finding could be explained from the concept that the nucleation sites on the surface of GNPs increase with an increase in size of GNPs, which results in an increase in the number of cavitation bubbles. Acoustic cavitation in the presence of gold nanoparticles can be used as a way for improving therapeutic effects on the tumors.

Genetic variants in the folate metabolic pathway genes predict cutaneous melanoma-specific survival

BACKGROUND

Folate metabolism plays an important role in DNA methylation and nucleic acid synthesis and thus may function as a regulatory factor in cancer development. Genome-wide association studies (GWASs) have identified some single-nucleotide polymorphisms (SNPs) associated with cutaneous melanoma-specific survival (CMSS), but no SNPs were found in genes involved in the folate metabolic pathway.

OBJECTIVES

To examine associations between SNPs in folate metabolic pathway genes and CMSS.

METHODS

We comprehensively evaluated 2645 (422 genotyped and 2223 imputed) common SNPs in folate metabolic pathway genes from a published GWAS of 858 patients from The University of Texas MD Anderson Cancer Center and performed the validation in another GWAS of 409 patients from the Nurses' Health Study and Health Professionals Follow-up Study, in which 95/858 (11·1%) and 48/409 (11·7%) patients died of cutaneous melanoma, respectively.

RESULTS

We identified two independent SNPs (MTHFD1 rs1950902 G>A and ALPL rs10917006 C>T) to be associated with CMSS in both datasets, and their meta-analysis yielded an allelic hazards ratio of 1·75 (95% confidence interval 1·32-2·32, P = 9·96 × 10^-5 ) and 2·05 (1·39-3·01, P = 2·84 × 10^-4 ), respectively. The genotype-phenotype correlation analyses provided additional support for the biological plausibility of these two variants' roles in tumour progression, suggesting that variation in SNP-related mRNA expression levels is likely to be the mechanism underlying the observed associations with CMSS.

CONCLUSIONS

Two possibly functional genetic variants, MTHFD1 rs1950902 and ALPL rs10917006, were likely to be independently or jointly associated with CMSS, which may add to personalized treatment in the future, once further validated. What is already known about this topic? Existing data show that survival rates vary among patients with melanoma with similar clinical characteristics; therefore, it is necessary to identify additional complementary biomarkers for melanoma-specific prognosis. A hypothesis-driven approach, by pooling the effects of single-nucleotide polymorphisms (SNPs) in a specific biological pathway as genetic risk scores, may provide a prognostic utility, and genetic variants of genes in folate metabolism have been reported to be associated with cancer risk. What does this study add? Two genetic variants in the folate metabolic pathway genes, MTHFD1 rs1950902 and ALPL rs10917006, are significantly associated with cutaneous melanoma-specific survival (CMSS). What is the translational message? The identification of genetic variants will make a risk-prediction model possible for CMSS. The SNPs in the folate metabolic pathway genes, once validated in larger studies, may be useful in the personalized management and treatment of patients with cutaneous melanoma.

Investigating the Cytotoxicity of Folate-Conjugated Bismuth Oxide Nanoparticles on KB and A549 Cell Lines

Purpose: Lately, bismuth-based nanomaterials have been widely utilized in medical researches such as imaging, drug delivery and radio-sensitization. Despite their advantages, bismuth-based compounds have shown toxic effects in humans. There are few studies on cytotoxicity effects of bismuth oxide (Bi2O3) nanoparticles (NPs) in-vitro. In this study, we aimed to investigate cytotoxicity of bare and also folate and 5-aminolevulinic acid (5-ALA)-conjugated Bi2O3 NPs on nasopharyngeal carcinoma (KB) and lung cancer (A549) cell lines.

Methods: B_i2O₃ NPs were synthesized and conjugated with folate and 5-ALA. KB and A549 cells were cultured and incubated with 10, 20, 50 and 100 μg/ml concentrations of bare and folate-5-ALA-conjugated NPs. The survival rates were obtained after 2 and 24 hours incubation of the cells with NPs using MTT assay. Also, apoptosis and ROS generation induced by the NPs in the treated cells were obtained using Caspases-3 activity assay and flow cytometry analysis, respectively.

Results: B_i2O₃ NPs were successfully synthesized with average size of 19.2 ± 6.5 nm, then conjugated with 5-ALA and folate. Either naked or folate-conjugated NPs were easily taken up by the cells in a concentration-dependent manner and showed cytotoxic effects. The significant cell death was noted at the concentrations more than 50 μg/ml for both compounds.

Conclusion: Results indicated low cytotoxicity of the prepared NPs at lower incubation periods, which is very important for their further applications. However, 24 hours incubation of the cells with both forms of NPs caused more cell killing and the cytotoxicity increased with increasing concentrations of the NPs.

Nanomedicine as a potent strategy in melanoma tumor microenvironment

Melanoma originated from melanocytes is the most aggressive type of skin cancer. Despite considerable progresses in clinical treatment with the discovery of BRAF or MEK inhibitors and monoclonal antibodies, the durability of response to treatment is often limited to the development of acquired resistance and systemic toxicity. The limited success of conventional treatment highlights the importance of understanding the role of melanoma tumor microenvironment in tumor developement and drug resistance. Nanoparticles represent a promising strategy for the development of new cancer treatments able to improve the bioavailability of drugs and increase their penetration by targeting specifically tumors cells and/or tumor environment. In this review, we will discuss the main influence of tumor microenvironment in melanoma growth and treatment outcome. Furthermore, third generation loaded nanotechnologies represent an exciting tool for detection, treatment, and escape from possible mechanism of resistance mediated by tumor microenvironment, and will be highlighted in this review.