Melanoma is the most aggressive form of skin cancer, and despite significant therapeutic advances over the past decade, a substantial number of patients still progress to a fatal outcome. The initiation and progression of melanoma are strongly influenced by interactions between melanoma cells and other components of the tumor microenvironment (TME). In this review, we focus on the interplay between fibroblasts resident in the tumor microenvironment and tumor cells. In particular, we examine the molecular mechanisms through which melanoma cells induce the transformation of resident fibroblasts into their active form, known as cancer-associated fibroblasts (CAFs). We also explore the role of CAFs in shaping the melanoma microenvironment (MME) and in organizing the pre-metastatic niche, a specialized microenvironment that forms in distant organs or tissues to support the survival and expansion of metastatic melanoma cells. Finally, we discuss emerging therapeutic strategies aimed at disrupting the interactions between CAFs, melanoma cells, and other components of the tumor microenvironment to improve treatment outcomes.

Nonylphenol (NP) is a chemical compound belonging to the class of alkylphenols (APs), known for its widespread environmental distribution and endocrine-disrupting properties. It is commonly used in the production of detergents, pesticides, and plastic materials and, owing to these properties, it can accumulate in both aquatic and terrestrial ecosystems. As a xenoestrogenic compound, NP can bind steroid receptors, including estrogen receptors (ERs), thereby activating ER-dependent pathways. In this work, we investigated the effects of NP alone and in combination with the endogenous hormones 17β-oestradiol (E2) and/or testosterone (T) on a human non-tumoral prostate cell line (PNT1A). Cell viability and migration assays, together with analysis of ER expression and localization, were carried out to assess the xenoestrogenic activity of NP, particularly in the presence of E2 and T. Our results showed that NP retained its endocrine-disrupting features in the mixtures, positively affecting cell viability, except for the NP+E2 mixture, in which cell viability did not significantly differ from control, suggesting an antagonistic interaction between NP and E2. The mixtures also interfered with steroid receptor dynamics, affecting receptor expression and delaying receptor localization and activation kinetics. Moreover, all mixtures negatively affected cell migration compared with treatment with endogenous hormones alone. In conclusion, our results demonstrate that NP retains its xenoestrogenic behavior in mixture, inducing a significant alteration in prostate cell homeostasis.