This study provides information regarding the in vitro effects of proteasome inhibitors on melanoma cell lines, and the molecular mechanisms involved. It also gives support to the future use of such inhibitors in the treatment of patients with melanoma, either administered alone or in combination with other drugs.

Melanoma is a malignant neoplasia that is highly resistant to chemotherapy and radiotherapy and is associated with poor prognosis in advanced stage. Targeting melanoma that harbors the common BRAF V600E mutation with kinase inhibitors, such as vemurafenib, reduces tumor burden, but these tumors frequently acquire resistance to these drugs. We previously proposed that T-type calcium channel (TTCC) expression may serve as a biomarker for melanoma progression and prognosis, and we showed that TTCC blockers reduce migration and invasion rates because of autophagy blockade only in BRAF V600E -mutant melanoma cells. Here, we demonstrated that high expression of the TTCC Cav3.1 isoform is related to autophagic status in vemurafenib-resistant BRAF V600E -mutant melanoma cells and human biopsies, and in silico analysis revealed an enrichment of Cav3.1 expression in post-treatment melanomas. We also demonstrated that the TTCC blocker mibefradil induces apoptosis and impairs migration and invasion via inhibition of autophagy in resistant melanoma cells and mouse xenograft models. Moreover, we identified an association between PTEN status and Cav3.1 expression in these cells as a marker of sensitivity to combination therapy in resistant cells. Together, our results suggest that TTCC blockers offer a potential targeted therapy in resistant BRAF V600E -mutant melanoma and a therapeutic strategy to reduce progression toward BRAF inhibitor resistance.

Tophi develop during the most advanced clinical stage of gout, and are usually located on or around the joints. However, unusual skin features caused by intradermal and/or subcutaneous deposition of tophaceous material at locations other than articular regions have been reported. We present the case of a patient with a condition that has been recently termed 'miliarial gout'. which is only the second such case, to our knowledge. A 51-year-old woman, who had a chronic joint disease that had been diagnosed and treated as psoriatic arthritis, presented with multiple asymptomatic, yellowish-white, firm papules (1-3 mm in size) on erythematous areas on the outside of her left leg. On histological examination of a skin biopsy, uric acid crystals were seen in the dermis and subcutis. The patient also had a raised level of serum urate, consistent with a diagnosis of gout. Treatment with allopurinol led to rapid improvement. Intake of corticosteroids and diuretics was a possible triggering factor for the development of cutaneous tophi in this patient.