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Finding effective therapeutic targets to treat NRAS-mutated melanoma remains a challenge. Long non-coding RNAs (lncRNAs) recently emerged as essential regulators of tumorigenesis. Using a discovery approach combining experimental models and unbiased computational analysis complemented by validation in patient biospecimens, we identified a nuclear-enriched lncRNA (AC004540.4) that is upregulated in NRAS/MAPK-dependent melanoma, and that we named T-RECS. Considering potential innovative treatment strategies, we designed antisense oligonucleotides (ASOs) to target T-RECS. T-RECS ASOs reduced the growth of melanoma cells and induced apoptotic cell death, while having minimal impact on normal primary melanocytes. Mechanistically, treatment with T-RECS ASOs downregulated the activity of pro-survival kinases and reduced the protein stability of hnRNPA2/B1, a pro-oncogenic regulator of MAPK signaling. Using patient- and cell line- derived tumor xenograft mouse models, we demonstrated that systemic treatment with T-RECS ASOs significantly suppressed the growth of melanoma tumors, with no noticeable toxicity. ASO-mediated T-RECS inhibition represents a promising RNA-targeting approach to improve the outcome of MAPK pathway-activated melanoma.

The long non-coding RNA (lncRNA) MALAT1 is a regulator of oncogenesis and cancer progression. MAPK-pathway upregulation is the main event in the development and progression of human cancer, including melanoma and recent studies have shown that MALAT1 has a significant impact on the regulation of gene and protein expression in the MAPK pathway. However, the role of MALAT1 in regulation of gene and protein expression of the MAPK-pathway kinases RAS, RAF, MEK and ERK in melanoma is largely unknown. We demonstrate the impacts of antisense oligonucleotide (ASO)-based MALAT1-inhibition on MAPK-pathway gene regulation in melanoma. Our results showed that MALAT1-ASO treatment decreased BRAF RNA expression and protein levels, and MALAT1 had increased correlation with MAPK-pathway associated genes in melanoma patient samples compared to healthy skin. Additionally, drug-induced MAPK inhibition upregulated MALAT1-expression, a finding that resonates with a paradigm of MALAT1-expression presented in this work: MALAT1 is downregulated in melanoma and other cancer types in which MALAT1 seems to be associated with MAPK-signaling, while MALAT1-ASO treatment strongly reduced the growth of melanoma cell lines, even in cases of resistance to MEK inhibition. MALAT1-ASO treatment significantly inhibited colony formation in vitro and reduced tumor growth in an NRAS-mutant melanoma xenograft mouse model in vivo, while showing no aberrant toxic side effects. Our findings demonstrate new insights into MALAT1-mediated MAPK-pathway gene regulation and a paradigm of MALAT1 expression in MAPK-signaling-dependent cancer types. MALAT1 maintains essential oncogenic functions, despite being downregulated.

Despite major advances in targeted melanoma therapies, drug resistance limits their efficacy. Long noncoding RNAs (lncRNAs) are transcriptome elements that do not encode proteins but are important regulatory molecules. LncRNAs have been implicated in cancer development and response to different therapeutics and are thus potential treatment targets; however, the majority of their functions and molecular interactions remain unexplored. In this study, we identify a novel cytoplasmic intergenic lincRNA (MIRAT), which is upregulated following prolonged MAPK inhibition in NRAS mutant melanoma and modulates MAPK signaling by binding to the MEK scaffold protein IQGAP1. Collectively, our results present MIRAT's direct modulatory effect on the MAPK pathway and highlight the relevance of cytoplasmic lncRNAs as potential targets in drug resistant cancer.

Background: Hidradenitis suppurativa (HS) is a debilitating inflammatory skin disease. Tetracyclines are one of the few therapeutic options recommended for mild‐to‐moderate disease. This study aimed to investigate the efficacy of systemic fusidic acid's (FA) effectiveness in treating HS. Methods: This retrospective study analyzed 55 FA therapy cycles (TC, average weekly dose: 6409 mg; range: 5250–9800 mg; 2–12 weeks) in 49 patients. The outcome was evaluated using the Physician's Global Assessment (PGA) scale. Therapy response was defined as any reduction of inflammatory activity without the occurrence of flares. We also characterized adverse events and investigated predictors for treatment success. Results were compared to a matched control group receiving doxycycline. Results: FA treatment (55 treatment cycles (TC); male: 45.5%; female: 54.5%) showed an overall response rate of 70.9% (39 TC). No worsening was observed. Significantly higher response rates were observed in females (83.3%, P = 0.026) and Hurley I (90.9%, P = 0.008). After multivariate adjustment, higher response rates were associated with the Hurley grade (P = 0.046) but not with gender (P = 0.0174). Adverse reactions (21.8% gastrointestinal symptoms) occurred in 27.3% (15 TC) and 46.7% within the first 4 weeks. Similar results were observed in the doxycycline control group (overall response rate: 76.4%). Conclusion: Oral FA is safe and improves symptoms in most patients. HS patients could benefit from oral FA treatment, especially in case of contraindications or resistance to tetracyclines. [ABSTRACT FROM AUTHOR]

In melanoma, mutant and thereby constantly active neuroblastoma rat sarcoma (NRAS) affects 15-20% of tumors, contributing to tumor initiation, growth, invasion, and metastasis. Recent therapeutic approaches aim to mimic RAS extinction by interfering with critical signaling pathways downstream of the mutant protein. This study investigates the phosphoproteome of primary human melanocytes bearing mutations in the two hot spots of NRAS, NRAS(G12) and NRAS(Q61). Stable isotope labeling by amino acids in cell culture followed by mass spectrometry identified 14,155 spectra of 3,371 unique phosphopeptides mapping to 1,159 proteins (false discovery rate < 2%). Data revealed pronounced PI3K/AKT signaling in NRAS(G12V) mutant cells and pronounced mitogen-activated protein kinase (MAPK) signaling in NRAS(Q61L) variants. Computer-based prediction models for kinases involved, revealed that CK2α is significantly overrepresented in primary human melanocytes bearing NRAS(Q61L) mutations. Similar differences were found in human NRAS(Q61) mutant melanoma cell lines that were also more sensitive to pharmacologic CK2α inhibition compared with NRAS(G12) mutant cells. Furthermore, CK2α levels were pronounced in patient samples of NRAS(Q61) mutant melanoma at the mRNA and protein level. The preclinical findings of this study reveal that codon 12 and 61 mutant NRAS cells have distinct signaling characteristics that could allow for the development of more effective, mutation-specific treatment modalities.

ImportanceImmunomodulatory anticancer drugs, such as the anti-programmed death-1 drug pembrolizumab, have shown promising results in trials, and more patients will receive such treatments. Little is known about cutaneous adverse events (AEs) caused by these drugs and their possible correlation with treatment response.ObjectiveTo describe the frequency and spectrum of cutaneous AEs linked with pembrolizumab and their possible correlation with treatment response.Design, setting, and participantsA single-institution, retrospective medical record review was conducted of patients with cancer who were treated with pembrolizumab from March 1, 2011, to May 28, 2014. The review comprised 83 consecutive patients who were enrolled in 2 clinical trials, received at least 1 dose of pembrolizumab, and had at least 1 follow-up visit. Patients were grouped according to the following therapeutic regimen for pembrolizumab: 43 received 10 mg/kg every 3 weeks, 24 received 10 mg/kg every 2 weeks, and 16 received 2 mg/kg every 3 weeks. Sixty-six patients were treated for melanoma, 15 patients for lung cancer, 1 patient for prostate cancer, and 1 patient for Merkel cell carcinoma. Median follow-up was 15 weeks (range, 2-105 weeks). The analysis was conducted from March 1 to September 30, 2014.Main outcomes and measuresOccurrence, severity, and type of cutaneous AEs, as well as disease progression and response to pembrolizumab treatment.ResultsThirty-five patients (42%) developed cutaneous AEs attributed to pembrolizumab. The most common cutaneous AEs were macular papular eruption (24 [29%]), pruritus (10 [12%]), and hypopigmentation (7 [8%]). All 7 patients who developed hypopigmentation were treated for melanoma. Survival analyses showed that patients who developed cutaneous AEs had significantly longer progression-free intervals in all 3 groups (pembrolizumab, 10 mg/kg, every 3 weeks, P = .001; pembrolizumab, 10 mg/kg, every 2 weeks, P = .003; pembrolizumab, 2 mg/kg, every 3 weeks, P = .009) compared with patients who did not develop cutaneous AEs.Conclusions and relevancePembrolizumab therapy was associated with cutaneous AEs in 42% of patients. The development of cutaneous AEs, especially of hypopigmentation in patients with melanoma, could point toward better treatment response.

BackgroundBRAF inhibitor (BRAFi) and MEK inhibitor (MEKi) frequently cause cutaneous adverse events.ObjectiveWe sought to investigate the cutaneous safety profile of BRAFi versus BRAFi and MEKi combination regimens.MethodsWe performed a retrospective cohort study, collecting data from 44 patients with melanoma treated either with BRAFi (vemurafenib or dabrafenib) or BRAFi and MEKi combination regimens (vemurafenib + cobimetinib or dabrafenib + trametinib). Patient characteristics, and the occurrence and severity of cutaneous adverse events, are described.ResultsThe development of cutaneous adverse events was significantly less frequent (P = .012) and occurred after longer treatment time (P = .025) in patients treated with BRAFi and MEKi combination regimen compared with patients treated with BRAFi monotherapy. Among patients who received both BRAFi and the combination of BRAFi and MEKi at different time points during their treatment course, the development of squamous cell carcinoma or keratoacanthoma was significantly less frequent when they received the combination regimen (P = .008). Patients receiving vemurafenib developed more cutaneous adverse events (P = .001) and in particular more photosensitivity (P = .010) than patients who did not.LimitationsThere were a limited number of patients.ConclusionCombination regimen with BRAFi and MEKi shows fewer cutaneous adverse events and longer cutaneous adverse event-free interval compared with BRAFi monotherapy.

Background: Programmed death‐1 (PD‐1) antibodies and BRAF + MEK inhibitors are widely used for adjuvant therapy of fully resected high‐risk melanoma. Little is known about treatment efficacy outside of phase III trials. This real‐world study reports on clinical outcomes of modern adjuvant melanoma treatment in specialized skin cancer centers in Germany, Austria and Switzerland. Methods: Multicenter, retrospective study investigating stage III–IV melanoma patients receiving adjuvant nivolumab (NIV), pembrolizumab (PEM) or dabrafenib + trametinib (D + T) between 1/2017 and 10/2021. The primary endpoint was 12‐month recurrence‐free survival (RFS). Further analyses included descriptive and correlative statistics, and a multivariate linear‐regression machine learning model to assess the risk of early melanoma recurrence. Results: In total, 1198 patients from 39 skin cancer centers from Germany, Austria and Switzerland were analysed. The vast majority received anti PD‐1 therapies (n = 1003). Twelve‐month RFS for anti PD‐1 and BRAF + MEK inhibitor‐treated patients were 78.1% and 86.5%, respectively (hazard ratio [HR] 1.998 [95% CI 1.335–2.991]; p = 0.001). There was no statistically significant difference in overall survival (OS) in anti PD‐1 (95.8%) and BRAF + MEK inhibitor (96.9%) treated patients (p > 0.05) during the median follow‐up of 17 months. Data indicates that anti PD‐1 treated patients who develop immune‐related adverse events (irAEs) have lower recurrence rates compared to patients with no irAEs (HR 0.578 [95% CI 0.443–0.754], p = 0.001). BRAF mutation status did not affect overall efficacy of anti PD‐1 treatment (p > 0.05). In both, anti PD‐1 and BRAF + MEK inhibitor treated cohorts, data did not show any difference in 12‐month RFS and 12‐month OS comparing patients receiving total lymph node dissection (TLND) versus sentinel lymph node biopsy only (p > 0.05). The recurrence prediction model reached high specificity but only low sensitivity with an AUC = 0.65. No new safety signals were detected. Overall, recorded numbers and severity of adverse events were lower than reported in pivotal phase III trials. Conclusions: Despite recent advances in adjuvant melanoma treatment, early recurrence remains a significant clinical challenge. This study shows that TLND does not reduce the risk of early melanoma recurrence and should only be considered in selected patients. Data further highlight that variables collected during clinical routine are unlikely to allow for a clinically relevant prediction of individual recurrence risk. [ABSTRACT FROM AUTHOR]