Pigment Cell & Melanoma Research最新文献

UVA radiation, a primary risk factor in melanoma progression, partly acts through the mediation of reactive oxygen species (ROS). The role of ROS in driving cutaneous melanoma toward an invasive phenotype and whether it occurs through opsins (OPNs), which are photosensitive G protein-coupled receptors, is not fully understood. This study focuses on the impact of UVA radiation on melanoma cell proliferation, with a special emphasis on OPN3. Investigating the biphasic response to various UVA doses (0.75–9 J/cm²) in A375 and MV3 cell lines, and using EdU and CCK-8 assays, we observed dose-dependent changes in cell proliferation. Interestingly, UVA irradiation at these doses of 0.75, 1.5 and 3 J/cm² did not significantly induce ROS production. Our study further delves into the role of OPN3, a photosensitive receptor, in melanoma progression. Following UVA exposure, an increase in OPN3 expression was observed in melanoma cells lines A375 and MV3, indicating its role as a UVA-sensitive sensor and its influence on cell proliferation. Additionally, UVA-induced calcium flux in two melanoma cells lines pointed to a calcium-dependent G protein-coupled pathway in melanoma proliferation, mediated by OPN3 and not reliant on ROS. This research sheds light on the mechanism of UVA-induced melanoma progression, underscoring OPN3 as a pivotal regulator and advancing our understanding of UVA's interaction with opsins in melanoma progression.

Vitiligo is a chronic autoimmune disease, and current treatments for vitiligo have limited efficacy. Janus kinase (JAK) inhibitors could offer new therapeutic options. To evaluate the efficacy and safety of baricitinib, an oral JAK1/2 inhibitor, combined with narrow-band ultraviolet B (NB-UVB) in vitiligo treatment. This prospective, controlled, open-label study included adults with progressive non-segmental vitiligo (NSV). Patients were assigned to combination therapy with baricitinib 2 mg daily and NB-UVB three times a week or NB-UVB alone three times a week (control). The primary endpoint was the proportion of patients achieving 50% or greater improvement from baseline in the total Vitiligo Area Scoring Index (T-VASI50) at week 16. Of the 33 patients (mean age, 34.1 years; 27.3% women) who completed the study, 12 of 17 (70.6%) patients in the combination group and 2 of 16 (12.5%) in the control group had a T-VASI50 response at week 16 (relative risk [RR] = 5.6; 95% CI = 1.5–21.4; p = 0.001). Adverse events were minor, including erythema, mild blister after phototherapy and acne. Combination therapy with low-dose baricitinib and NB-UVB was effective and well tolerated in adults with progressive NSV.

The 2023 Cure Ocular Melanoma (CURE OM) Global Science Meeting was held in Philadelphia on November 6, 2023. There is increased awareness and dedicated research in uveal melanoma (UM), but unmet needs remain in the prevention, detection, and treatment of UM. The purpose of this meeting was to provide an international forum for the exchange of research ideas, to allow for discussion of basic science as well as clinical research on UM, and to gather input about advocacy and patient needs.

In skin, melanin is synthesized and stored in melanosomes. In epidermal melanocytes, melanosomes are transported to and internalized by the neighboring keratinocytes, subsequently leading to skin pigmentation. Ultraviolet (UV) radiation induces the release of acetylcholine (ACh) from keratinocytes, which in turn activates ACh receptors (AChRs) on nearby melanocytes, forming a proposed “skin synapse”. Here, we illustrated that the UV-induced melanosome release from cultured B16F10 melanoma cells could be mediated by co-actions of ACh. In the cell cultures, UV exposure robustly elicited melanosome release. Applied bethanechol (BeCh), an agonist of muscarinic AChR (mAChR), could significantly enhance the release. In parallel, the intracellular Ca²⁺ mobilization was regulated. The applied antagonists of M1 and/or M3 mAChRs could block the UV-induced melanosome release and the mobilization of intracellular Ca²⁺. The phosphorylation of PKC, triggered by UV and BeCh treatments, could be suppressed by the applied mAChR antagonists. The expressions of tethering complex for exocytosis, for example, Sec8, Exo70, and Rab11b, as well as synaptotagmin, were increased under UV exposure together with mAChR agonist: The inductions were fully abolished by M1 or M3 antagonist. Here, we hypothesize that the cholinergic signaling is playing roles in UV-induced exocytosis of melanosomes.