Molecular pathology of cutaneous melanoma

A cross-sectional study of clinical, dermoscopic, histopathological, and molecular patterns of scalp melanoma in patients with or without androgenetic alopecia

Scalp melanoma (SM) has a worse prognosis than melanoma in other locations likely because of late diagnosis due to hair coverage, difficulties in interpreting dermoscopy findings, and its unique molecular profile. We aimed to describe the clinical, histopathological, molecular, and dermoscopic patterns of SM and its relation to androgenetic alopecia/elastosis at the tumor site. Through a retrospective cross-sectional study, we identified all SM diagnosed at the A.C.Camargo Cancer Center between 2008 and 2018. In all, 48 SM were analyzed: 45.8% of which exhibited moderate/severe androgenetic alopecia and 54.1% exhibited elastosis. Androgenetic alopecia/elastosis at the site of the SM was associated with older age (p < 0.001), chronic sun damage (p < 0.001), lentigo maligna subtype (p = 0.029), and photodamaged dermoscopic pattern (p < 0.001). Additionally, 41 cases were evaluated with a 14-gene panel: 53.7% displayed mutations and 46.3% were wild-type. BRAF mutations were most common (77%), with BRAF V600K being more frequent (50%) than BRAF V600E (31.2%). The NF1 gene was evaluated in 40 samples, of which 20% exhibited mutations. SM presents differently in areas covered by hair compared to in areas with androgenetic alopecia. Patients without alopecia may have higher Breslow thickness due to late diagnosis because of hair concealment. The high frequency of detrimental mutations can also explain the poor prognosis of SM.

Prognostic score model-based signature genes for predicting the prognosis of metastatic skin cutaneous melanoma

PURPOSE

Cutaneous melanoma (SKCM) is the most invasive malignancy of skin cancer. Metastasis to distant lymph nodes or other system is an indicator of poor prognosis in melanoma patients. The aim of this study was to identify reliable prognostic biomarkers for SKCMs.

METHODS

Four RNA-sequencing datasets associated with SKCMs were downloaded from the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) database as well as corresponding clinical information. Differentially expressed genes (DEGs) were screened between primary and metastatic samples by using MetaDE tool. Weighted gene co-expression network analysis (WGCNA) was conducted to screen functional modules. A prognostic score (PS)-based predictive model and nomogram model were constructed to identify signature genes and independent clinicopathologic factors.

RESULTS

Based on MetaDE analysis and WGCNA, a total of 456 overlapped genes were identified as hub genes related to SKCMs progression. Functional enrichment analysis revealed these genes were mainly involved in the hippo signaling pathway, signaling pathways regulating pluripotency of stem cells, pathways in cancer. In addition, eight optimal DEGs (RFPL1S, CTSV, EGLN3, etc.) were identified as signature genes by using PS model. Cox regression analysis revealed that pathologic stage T, N and recurrence were independent prognostic factors. Three clinical factors and PS status were incorporated to construct a nomogram predictive model for estimating the three years and five-year survival probability of individuals.

CONCLUSIONS

The prognosis prediction model of this study may provide a promising method for decision making in clinic and prognosis predicting of SKCM patients.

Carfilzomib in Combination with Bortezomib Enhances Apoptotic Cell Death in B16-F1 Melanoma Cells

Simple Summary

The incidence rate of metastatic melanoma has been rapidly increasing worldwide and its 5-year survival rate is very low. Due to partial responses, various side effects, and resistance to any known cancer therapeutics, more potent and safer therapeutics are needed to increase the survival rate of patients with melanoma. Since proteasome inhibitors, such as bortezomib and carfilzomib, have been suggested as treatments for various cancers, we investigated their potential for the treatment of melanoma by studying their molecular mechanisms of action in B16-F1 melanoma cells. In this study, we found that both bortezomib and carfilzomib lead to apoptosis via ER stress as well as ROS accumulation and MMP loss in melanoma cells. Bortezomib and carfilzomib synergistically reduced B16-F1 tumor growth in vitro and in a C57BL/6 xenograft mouse model. Therefore, a combination therapy with carfilzomib and bortezomib at submaximal concentrations may reduce their side effects and be beneficial for melanoma treatment.

Abstract

Proteasome inhibitors, such as bortezomib (BZ) and carfilzomib (CFZ), have been suggested as treatments for various cancers. To utilize BZ and/or CFZ as effective therapeutics for treating melanoma, we studied their molecular mechanisms using B16-F1 melanoma cells. Flow cytometry of Annexin V-fluorescein isothiocyanate-labeled cells indicated apoptosis induction by treatment with BZ and CFZ. Apoptosis was evidenced by the activation of various caspases, including caspase 3, 8, 9, and 12. Treatment with BZ and CFZ induced endoplasmic reticulum (ER) stress, as indicated by an increase in eIF2α phosphorylation and the expression of ER stress-associated proteins, including GRP78, ATF6α, ATF4, XBP1, and CCAAT/enhancer-binding protein homologous protein. The effects of CFZ on ER stress and apoptosis were lower than that of BZ. Nevertheless, CFZ and BZ synergistically induced ER stress and apoptosis in B16-F1 cells. Furthermore, the combinational pharmacological interactions of BZ and CFZ against the growth of B16-F1 melanoma cells were assessed by calculating the combination index and dose-reduction index with the CompuSyn software. We found that the combination of CFZ and BZ at submaximal concentrations could obtain dose reduction by exerting synergistic inhibitory effects on cell growth. Moreover, this drug combination reduced tumor growth in C57BL/6 syngeneic mice. Taken together, these results suggest that CFZ in combination with BZ may be a beneficial and potential strategy for melanoma treatment.

Characterization of phenolic profile by LC-ESI-MS/MS and enzyme inhibitory activities of two wild edible garlic: Allium nigrum L. and Allium subhirsutum L

In our study, Allium nigrum L. and Allium subhirsutum L. were investigated in terms of phenolic profile, acetylcholinesterase (AChE), butyrylcholinesterase (BuChE), and tyrosinase inhibitory potentials. The colorimetric analysis revealed that the highest levels of total phenol (45.6, 15.8 mg GAE/g extract, respectively) and total flavonoid contents (8.2, 5.7 mg QE/g extract, respectively) were found in the bulbs of both plants. About 30 compounds were determined by LC-ESI-MS/MS with validated method and 3-hydroxybenzoic acid (2,188.4 μg/g extract) and p-coumaric acid (1,700.8 μg/g extract) were major phenolic acids. (-)-Epigallocatechin gallate (998.3 µg/g extract) and genistein (159.3 μg/g extract) which are neuroprotective compounds were the predominant flavonoids for A. nigrum and A. subhirsutum, respectively. Enzyme inhibitory activities of samples were performed by spectrophotometrically with 96-well microplate reader. All samples showed anti-AChE, anti-BuChE, and anti-tyrosinase activities and the aerial part of A. nigrum was the most potent (IC₅₀ 6.1, 3.27, 22.31 µg/ml, respectively). PRACTICAL APPLICATIONS: Many Allium species, especially those cultivated, are consumed in different countries as food in different ways. In the literature, studies on these species have generally focused on organosulfur compounds of the species. In our present study, phenolic compounds having a wide range of biological activities were determined in different parts of the two Allium species consumed as food. We also investigated in vitro cholinesterases and tyrosinase inhibition activities of these species. A correlation was observed between phenolic compounds and enzyme inhibition activities. These results were further explored and confirmed by principal component analysis (PCA). PCA revealed that samples were discriminated from each other according to phenolic compounds and enzyme inhibitory potencies. Conclusively, this study determines that the chemical profiles and biological activities of A. nigrum and A. subhirsutum.