Preclinical Study of Immunological Isoxazole Derivatives as a Potential Support for Melanoma Chemotherapy

(1) Background: Melanoma is an aggressive neoplasm derived from melanocyte precursors with a high metastatic potential. Responses to chemotherapy and immunotherapy for melanoma remain weak, underlining the urgent need to develop new therapeutic strategies for the treatment of melanoma. (2) Methods: The viability of NHDF and A375 cell cultures after the administration of the tested isoxazole derivatives was assessed after 24-h and 48-h incubation periods with the test compounds in the MTT test. ROS and NO scavenging analyses, a glycoprotein-P activity analysis, a migration assay, a test of apoptosis, and a multiple-criteria decision analysis were also performed. (3) Results: All compounds that were tested resulted in a slower migration of melanoma neoplastic cells. The mechanism of the antitumor activity of the tested compounds was confirmed—i.e., the pro-apoptotic activity of the compounds in A375 cell cultures. Compound O7K qualified for further research. (4) Conclusions: All the tested compounds inhibited the formation of melanoma metastases and demonstrated the ability to reduce the risk of developing drug resistance in the tumor. The MCDA results showed that O7K showed the strongest antitumor activity.

Effects of RNA methylation N6-methyladenosine regulators on malignant progression and prognosis of melanoma

Background Melanoma is an extremely aggressive type of skin cancer and experiencing a expeditiously rising mortality in a current year. Exploring new potential prognostic biomarkers and therapeutic targets of melanoma are urgently needed. The ambition of this research was to identify genetic markers and assess prognostic performance of N6-methyladenosine (m6A) regulators in melanoma. Methods Gene expression data and corresponding clinical informations of melanoma patients as well as sequence data of normal controls are collected from The Cancer Genome Atlas (TCGA) and the Genotype-Tissue Expression (GTEx) databases. Quantitative real-time PCR (qRT-PCR) analysis was carried out to detect the RNA expression of IGF2BP3 in A375 cell line, melanoma tissues, and normal tissues. Western blot, cell proliferation, and migration assays were performed to assess the ability of IGF2BP3 in A375 cell line. Results Differently expressed m6A regulators between tumor samples and normal samples were analyzed. A three-gene prognostic signature including IGF2BP3, RBM15B, and METTL16 was constructed, and the risk score of this signature was identified to be an independent prognostic indicator for melanoma. In addition, IGF2BP3 was verified to promote melanoma cell proliferation and migration in vitro and associate with lymph node metastasis in clinical samples. Moreover, risk score and the expression of IGF2BP3 were positively associated with the infiltrating immune cells and these hub genes made excellent potential drug targets in melanoma. Conclusion We identified the genetic changes in m6A regulatory genes and constructed a three-gene risk signature with distinct prognostic value in melanoma. This research provided new insights into the epigenetic understanding of m6A regulators and novel therapeutic strategies in melanoma.

Gene Instability-Related lncRNA Prognostic Model of Melanoma Patients via Machine Learning Strategy

Background. Melanoma is a common tumor characterized by a high mortality rate in its late stage. After metastasis, current treatment methods are relatively ineffective. Many studies have shown that long noncoding RNA (lncRNA) may participate in gene mutation and genomic instability in cancer. Methods. We downloaded transcriptome data, mutation data, and clinical follow-up data of melanoma patients from The Cancer Genome Atlas. We divided samples into groups according to the number of somatic cell mutations and then performed a differential analysis to screen out the differentially expressed genes. We then divided samples into genomic unstable and genomic stable groups. We compared lncRNA expression profiles in these groups and constructed a protein-coding genes network coexpressed with selected lncRNA to analyze the pathways enriched by these genes. Two machine learning methods, least absolute shrinkage and selector operation (LASSO) and support vector machine-recursive feature elimination (SVM-RFE), were applied to conduct the lncRNA-related prognostic model. Afterward, we performed survival analysis, risk correlation analysis, independent prognostic analysis, and clinical subgroup model validation. Finally, through wound healing assay and transwell assay, the function of AATBC was verified by A375 cell lines. Results. We screened 61 prognostic-related lncRNAs and constructed an lncRNA-mRNA coexpression network based on these lncRNAs. Seven lncRNAs were selected as common characteristic factors based on the two machine learning methods. The model formula was as follows: risk score = 0.085 ∗ AATBC + 0.190 ∗ AC026689.1−0.117 ∗ AC083799.1 + 0.036 ∗ AC091544.6−0.039 ∗ LINC01287−0.291 ∗ SPRY4.AS1 + 0.056 ∗ ZNF667.AS1. The seven lncRNAs in this formula are key candidates. Cell experiments have verified that knocking down AATBC in A375 cell lines can reduce the proliferation and invasion ability of melanoma cells. Conclusion. The lncRNA we identified provides a new way to study lncRNA’s role in the genomic instability of melanoma. Our findings may provide essential candidate biomarkers for the diagnosis and treatment of melanoma.

Naringin and 5-fluorouracil suppress inflammatory Cytokines in human skin cancer cell line

Naringin is a citrus flavonoid recently studied for anti-inflammatory activity in numerous cancer cells. In this study, the anti-inflammatory properties of naringin along with 5-fluorouracil in human skin cancer cell lines A375 was analyzed. A375 cells were treated with naringin, 5-fluorouracil alone, and combination. MTT assay and cell viability assays was demonstrated to detect the inhibitory effects of naringin or 5-fluorouracil on cell proliferation. mRNA expression of TNFα, IL-6, IL-1β, and NFκB were determined using quantitative RT-PCR. The effect of naringin and 5-fluorouracil combination significantly inhibited the growth and proliferation of the A375 cells in a concentration dependent manner with the IC50 values of naringin (24.75 μM) 5-fluorouracil (2.5 μM). The combination of naringin+5-fluorouracil on A375 cell lines at a concentration of half IC50 values (12µM+1 μM). Naringin and 5-fluorouracil combination also decreased the level of TNFα, IL-6, IL-1β, and NFκB mRNA in the A375 cell line. Naringin and 5-fluorouracil exerted anti-inflammatory effect through the suppression of NF-kB, IL-1β, TNFα, IL-6 in A375 cells. Taken together, our results suggested that treating A375 with naringin and 5-fluorouracil combination may have future applications in treating skin cancers through its anti-inflammatory effect.

Virtual Screening for Type II B Inhibitors of B-RafV600E Kinase

Background: B-RafV600E kinase was identified as an important target in current cancer treatment, and the type II B inhibitors show good qualities in preclinical studies. Therefore, it is very important to discover novel II B inhibitors of B-RafV600E kinase. Methods: In order to discover novel II B inhibitors of B-RafV600E kinase, virtual screening against ZINC database was performed by using a combination of pharmacophore modelling, molecular docking, 3DQSAR model and binding free energy (ΔGbind) calculation studies. The inhibitory activities against A375 cell lines of the hit compounds were tested by using MTT assay. Results: Five promising hit compounds were obtained after screening, and all the five hit compounds showed good inhibitory rates against A375 cell lines. Conclusion: The combined approach of the virtual screening in our work is effective, which can be used to discover novel inhibitors with a new skeleton. In addition, the five compounds obtained from the screening showed good inhibitory rates against A375 cell lines, which can be considered to develop new II B inhibitors of B-RafV600E kinase.

The Inhibition of Cell Growth Through the EGFR/ERK/MMP-2 Pathway Induced by Ampelopsin in the Human Malignant Melanoma A375 Cell Line

Malignant melanoma is one of the most aggressive skin cancers, having a very high mortality rate. However, its effective treatment is not clear. Ampelopsin, a plant flavonoid, has been reported to inhibit cell growth and/or induce apoptosis in various types of tumor. In this study, it was shown that ampelopsin significantly inhibits melanoma A375 cell line proliferation in a concentration-dependent/time-dependent manner. The flow cytometric data clearly demonstrated that ampelopsin causes cell cycle arrest in the G2/M phase. Moreover, it also confirmed that growth inhibition mediated by treatment with ampelopsin is related to the decreased expression of Cdc2, Cdc25c, cyclin B1, and activation of caspase-3 and Bax, purportedly by epidermal growth factor receptor (EGFR), extracellular regulated protein kinases, and matrix metalloproteinase-2 (MMP-2) downregulation. As a result of this work, these findings suggest that ampelopsin inhibits human malignant melanoma A375 cell line proliferation by suppressing the EGFR/ERK/MMP-2 pathway.

Triterpenoid Saponin and Lignan Glycosides from the Traditional Medicine Elaeagnus angustifolia Flowers and Their Cytotoxic Activities

A new triterpenoid saponin, named terpengustifol A (1), and two new lignan glucosides, phengustifols A and B (2 and 3), were isolated from the flowers of Elaeagnus angustifolia. Their structures were determined by the extensive analysis of the spectroscopic data (including NMR and HRMS) and ECD calculations. Compound 1 possesses an unusual monoterpene (Z)-6-hydroxy-2,6-dimethylocta-2,7-dienoyl unit at C-21. Compounds 2 and 3 are a pair of diastereoisomers, while their aglycones are a pair of enantiomers. Compounds 1 and 2 exhibited moderate cytotoxic activities against A375 cell lines with IC50 values at 12.1 and 15.6 μM, respectively. This is firstly reported the triterpenoid saponin and lignans isolated from the Elaeagnus angustifolia flowers.