The development of cutaneous melanoma is influenced by genetic factors, including BRAF mutations and environmental factors, such as ultraviolet exposure.,Its progression has been also associated with the involvement of several tumour microenvironmental molecules.,Among these, nuclear factor-κB (NF-κB) has been indicated as a key player of osteopontin (OPN) and matrix metalloproteinase-9 (MMP-9) activation.,However, whether NF-κB plays a role in the development and progression of melanoma in association with the OPN/MMP-9 axis according to the BRAFV600E mutation status has not been investigated in detail to date.,Thus, in the present study, in order to shed light on this matter, 148 patients with melanoma and 53 healthy donors were recruited for the analysis of OPN, MMP-9 and NF-κB.,Significantly higher circulating levels of OPN and MMP-9 were observed in the patients with melanoma when compared to the healthy donors.,Similar data were obtained for NF-κB p65 activity.,The OPN levels did not differ significantly between melanomas with or without BRAFV600E mutation.,However, as regards NF-κB and MMP-9, significant differences were observed between the melanomas with or without BRAFV600E mutation.,To determine whether NF-κB inhibition is associated with a decrease in the levels of OPN and MMP-9, peripheral blood mononuclear cells from 29 patients with melanoma were treated with the NF-κB inhibitor, dehydroxymethylepoxyquinomycin (DHMEQ), with or without OPN.,As expected, the inhibition of NF-κB induced a marked decrease in both the OPN and MMP-9 levels.,Furthermore, the decrease in MMP-9 levels was higher among melanomas harbouring the BRAFV600E mutation.,Overall, our data suggest that the activation of MMP-9 is associated with the BRAFV600E mutation status.,Furthermore, such an activation is mediated by NF-κB, suggesting its role as therapeutic target in patients with melanoma.
Anti-PD-1 therapy yields objective clinical responses in 30-40% of advanced melanoma patients.,Since most patients do not respond, predictive biomarkers to guide treatment selection are needed.,We hypothesize that MHC-I/II expression is required for tumour antigen presentation and may predict anti-PD-1 therapy response.,In this study, across 60 melanoma cell lines, we find bimodal expression patterns of MHC-II, while MHC-I expression was ubiquitous.,A unique subset of melanomas are capable of expressing MHC-II under basal or IFNγ-stimulated conditions.,Using pathway analysis, we show that MHC-II(+) cell lines demonstrate signatures of ‘PD-1 signalling', ‘allograft rejection' and ‘T-cell receptor signalling', among others.,In two independent cohorts of anti-PD-1-treated melanoma patients, MHC-II positivity on tumour cells is associated with therapeutic response, progression-free and overall survival, as well as CD4+ and CD8+ tumour infiltrate.,MHC-II+ tumours can be identified by melanoma-specific immunohistochemistry using commercially available antibodies for HLA-DR to improve anti-PD-1 patient selection.,Immunotherapy is used to treat melanoma, however patient responses vary widely highlighting the need for factors that can predict therapeutic success.,Here, the authors show that MHC-II molecules expressed by tumour cells are positively correlated with a good response to therapy and overall patient survival.