Recognition, Staging, and Management of Melanoma

Bulk and single-cell RNA-sequencing analyses along with abundant machine learning methods identify a novel monocyte signature in SKCM

Background

Global patterns of immune cell communications in the immune microenvironment of skin cutaneous melanoma (SKCM) haven't been well understood. Here we recognized signaling roles of immune cell populations and main contributive signals. We explored how multiple immune cells and signal paths coordinate with each other and established a prognosis signature based on the key specific biomarkers with cellular communication.

Methods

The single-cell RNA sequencing (scRNA-seq) dataset was downloaded from the Gene Expression Omnibus (GEO) database, in which various immune cells were extracted and re-annotated according to cell markers defined in the original study to identify their specific signs. We computed immune-cell communication networks by calculating the linking number or summarizing the communication probability to visualize the cross-talk tendency in different immune cells. Combining abundant analyses of communication networks and identifications of communication modes, all networks were quantitatively characterized and compared. Based on the bulk RNA sequencing data, we trained specific markers of hub communication cells through integration programs of machine learning to develop new immune-related prognostic combinations.

Results

An eight-gene monocyte-related signature (MRS) has been built, confirmed as an independent risk factor for disease-specific survival (DSS). MRS has great predictive values in progression free survival (PFS) and possesses better accuracy than traditional clinical variables and molecular features. The low-risk group has better immune functions, infiltrated with more lymphocytes and M1 macrophages, with higher expressions of HLA, immune checkpoints, chemokines and costimulatory molecules. The pathway analysis based on seven databases confirms the biological uniqueness of the two risk groups. Additionally, the regulon activity profiles of 18 transcription factors highlight possible differential regulatory patterns between the two risk groups, suggesting epigenetic event-driven transcriptional networks may be an important distinction. MRS has been identified as a powerful tool to benefit SKCM patients. Moreover, the IFITM3 gene has been identified as the key gene, validated to express highly at the protein level via the immunohistochemical assay in SKCM.

Conclusion

MRS is accurate and specific in evaluating SKCM patients' clinical outcomes. IFITM3 is a potential biomarker. Moreover, they are promising to improve the prognosis of SKCM patients.

Modern views on skin biopsy in the diagnostic algorithm of dermatooncological diseases

Background. Malignant neoplasms of the skin are fairly common tumors in the world population and among the population of Ukraine. The main method of diagnosing skintumors is a biopsy, which allows establishing a diagnosis at an early stage and ensures the cure of most patients. Purpose. To evaluate modern recommendations for skin biopsy in the diagnosis of dermato-onсological diseases. Materials and methods. The search for sources of information was conducted using the MEDLINE/PubMed, EMBASE/ExcerptaMedica, CochraneLibrary, PubMed та Google Scholar databases using the following keywords: skin biopsy, skin tumors, diagnosis, melanoma. Among the identified sources, works without statistical analysis, descriptions of individual cases, articles without conclusions, and sources with duplicate results were excluded. The search depth was 10 years. Results. As a result of the conducted search, 57 publications were found that corresponded to the declared purpose. The most common methods are: puncture, shaving, excisional and incisional biopsy. Most guidelines recommend full-thickness excisional biopsy as the preferred procedure for the diagnosis of suspected melanoma. It is indicated that a statistically significant mortality rate was found in the puncture biopsy group. Most observations showed no significant differences in melanoma recurrence between excisional biopsy and puncture groups. Given the clinical diversity of melanoma, there is no uniformity in the types of biopsies performed to diagnose melanoma. The most inaccurate method turned out to be the punch biopsy method, which is associated with an increased risk of underdiagnosis of melanoma. Conclusions. A skin biopsy is a mandatory first step to establish a definitive diagnosis of a skin tumor. Excisional complete biopsy is the most justified in most cases of diagnosis. Rational biopsy technique remains an issue that needs further study.

Discovery of novel ibrutinib analogues to treat malignant melanoma

A series of novel ibrutinib analogues was synthesized, and their proliferation inhibitory activities against various B lymphoma cell lines (DaudiB and Raji) and solid tumor cells (B16, CT26, HepG2 and 4T1) were evaluated. The most potent compound, YL7, exhibited strong antiproliferative activity in all cell lines, and its IC50 value in B16 cells was almost 9-fold better than that of ibrutinib. Mechanism of action studies showed that YL7 inhibited proliferation and migration and induced G1 cell cycle arrest, apoptosis and autophagy in B16 cells. Further assessment of in vivo antitumor efficacies demonstrated that YL7 significantly inhibited the growth of B16 melanoma. These preliminary studies suggest that it is reasonable to modify the structure of ibrutinib for antimelanoma treatment.