Pigment production is a unique character of melanocytes. Numerous factors are linked with melanin production, including genetics, ultraviolet radiation (UVR) and inflammation. Understanding the mechanism of melanogenesis is crucial to identify new preventive and therapeutic strategies in the treatment of melanoma. Here, we reviewed the current available literatures on the mechanisms of melanogenesis, including the signaling pathways of UVR-induced pigment production, MC1R’s central determinant roles and MITF as a master transcriptional regulator in melanogenesis. Moreover, we further highlighted the role of targeting BRAF, NRAS and MC1R in melanoma prevention and treatment. The combination therapeutics of immunotherapy and targeted kinase inhibitors are becoming the newest therapeutic option in advanced melanoma.

Cancer stem cells (CSCs) play crucial roles in tumor metastasis, therapy resistance, and immune evasion. Identifying and understanding the factors that regulate the stemness of tumor cells presents promising opportunities for developing effective therapeutic strategies. In this study on oral squamous cell carcinoma (OSCC), we confirmed the key role of KLF7 in maintaining the stemness of OSCC. Using chromatin immunoprecipitation sequencing and dual-luciferase assays, we identified ITGA2, a membrane receptor, as a key downstream gene regulated by KLF7 in the maintenance of stemness. Tumor sphere formation assays, flow cytometry analyses, and in vivo limiting dilution tumorigenicity evaluations demonstrated that knocking down ITGA2 significantly impaired stemness. Upon binding to its extracellular matrix (ECM) ligand, type I collagen, ITGA2 activates stemness-associated signaling pathways, including PI3K-AKT, MAPK, and Hippo. TC-I 15, a small-molecule inhibitor of the ITGA2-collagen interaction, significantly sensitizes oral squamous cell carcinoma (OSCC) to cisplatin in xenograft models. In summary, we reveal that the KLF7/ITGA2 axis is a crucial modulator of stemness in OSCC. Our findings suggest that ITGA2 is a promising therapeutic target, offering a novel anti-CSC strategy.

Purpose: To identify the specific intratumoral and microenvironmental heterogeneity of acral melanoma (AM) and mucosal melanoma (MM), we aimed to delineate their distinct cellular compositions, evolutionary trajectories, and subtype-specific therapeutic strategies. Experimental Design: Single-cell transcriptomic and genomic landscapes were analyzed across 42 melanoma (28 AM, 11 MM, and 3 nonacral cutaneous melanoma) samples, supplemented by in vitro and in vivo validation. Tumor and stromal cells were profiled using single-cell RNA sequencing, whole-exome sequencing, and functional assays, including transwell migration, co-culture systems, and xenograft models. Results: Tumor cells exhibited divergent evolutionary routes, with MM dominated by MGP+/PCOLCE+ subpopulations showing high epithelial-to-mesenchymal transition potential. MM displayed elevated neutrophil infiltration and CXCL3+ tumor-associated macrophages, whereas AM was enriched with PI16+ cancer-associated fibroblasts promoting tumor proliferation. Molecular classification revealed MM subtypes: an antigen-presenting subtype linked to favorable outcomes and a proliferative subtype associated with recurrence. TIGIT+ regulatory T cells were enriched in AM, suggesting targeted inhibition potential. Genomic analysis connected BRAF/NRAS mutations to ALDOA+ stem-like tumor cells and identified prostaglandin D2 synthetase as a therapeutic target in triple–wild-type/melanomas. Conclusions: Our study provides a comprehensive comparison of AM and MM, uncovering subtype-specific stromal–immune interactions and molecular programs. The findings highlight actionable targets (e.g., TIGIT in AM and CXCL3+ macrophages in MM) and propose a framework for precision therapies, biomarker-driven trials, and risk stratification to improve outcomes in these aggressive melanomas.

SAMHD1 is a human deoxyribonucleoside triphosphatase (dNTPase) known for its role as a restriction factor that targets a wide spectrum of viruses, its involvement in autoimmune disease Aicardi–Goutières syndrome (AGS), and its participation in innate immune regulation. The role of SAMHD1 in cancer, particularly its contribution to drug resistance, has gained increasing attention in recent years. One significant scientific challenge is how to inhibit SAMHD1 function in tumor cells while preserving its function in normal primary cells. Herein, we identified that increased SAMHD1 expression levels correlate with poor prognosis across multiple cancer types, and that SAMHD1 is upregulated in a variety of tumors. Through proteomic analysis and drug screening, we identified a promising strategy for selectively depleting tumor-associated SAMHD1 while minimizing its impact on SAMHD1 expression in key normal cell types. Our approach effectively enhanced tumor cytotoxicity when combined with multiple chemotherapeutic agents and suppressed tumor growth in vivo. Moreover, selective depletion of tumor-associated SAMHD1 activated innate immune responses, leading to enhanced tumor cell killing by immune cells. Collectively, these findings suggest that targeting tumor-specific SAMHD1 represents a novel and promising therapeutic strategy for cancers characterized by elevated SAMHD1 expression, offering potential for improved treatment outcomes in cancer patients with high SAMHD1 expression.

Table S2 from Single-Cell Transcriptomic Landscape Deciphers Intratumoral Heterogeneity and Subtypes of Acral and Mucosal Melanomas

Table S1 from Single-Cell Transcriptomic Landscape Deciphers Intratumoral Heterogeneity and Subtypes of Acral and Mucosal Melanomas