251 research outputs found

    A Variant in a MicroRNA complementary site in the 3' UTR of the KIT oncogene increases risk of acral melanoma.

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    MicroRNAs (miRNAs) are small ∼22nt single stranded RNAs that negatively regulate protein expression by binding to partially complementary sequences in the 3' untranslated region (3' UTRs) of target gene messenger RNAs (mRNA). Recently, mutations have been identified in both miRNAs and target genes that disrupt regulatory relationships, contribute to oncogenesis and serve as biomarkers for cancer risk. KIT, an established oncogene with a multifaceted role in melanogenesis and melanoma pathogenesis, has recently been shown to be upregulated in some melanomas, and is also a target of the miRNA miR-221. Here, we describe a genetic variant in the 3' UTR of the KIT oncogene that correlates with a greater than fourfold increased risk of acral melanoma. This KIT variant results in a mismatch in the seed region of a miR-221 complementary site and reporter data suggests that this mismatch can result in increased expression of the KIT oncogene. Consistent with the hypothesis that this is a functional variant, KIT mRNA and protein levels are both increased in the majority of samples harboring the KIT variant. This work identifies a novel genetic marker for increased heritable risk of melanoma

    Biology of advanced uveal melanoma and next steps for clinical therapeutics

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    Uveal melanoma is the most common intraocular malignancy although it is a rare subset of all melanomas. Uveal melanoma has distinct biology relative to cutaneous melanoma, with widely divergent patient outcomes. Patients diagnosed with a primary uveal melanoma can be stratified for risk of metastasis by cytogenetics or gene expression profiling, with approximately half of patients developing metastatic disease, predominately hepatic in location, over a 15-yr period. Historically, no systemic therapy has been associated with a clear clinical benefit for patients with advanced disease, and median survival remains poor. Here, as a joint effort between the Melanoma Research Foundation's ocular melanoma initiative, CURE OM and the National Cancer Institute, the current understanding of the molecular and immunobiology of uveal melanoma is reviewed, and on-going laboratory research into the disease is highlighted. Finally, recent investigations relevant to clinical management via targeted and immunotherpies are reviewed, and next steps in the development of clinical therapeutics are discussed

    Incidence of the V600K mutation among melanoma patients with BRAF mutations, and potential therapeutic response to the specific BRAF inhibitor PLX4032

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    Activating mutations in BRAF kinase are common in melanomas. Clinical trials with PLX4032, the mutant-BRAF inhibitor, show promising preliminary results in patients selected for the presence of V600E mutation. However, activating V600K mutation is the other most common mutation, yet patients with this variant are currently excluded from the PLX4032 trials. Here we present evidence that a patient bearing the BRAF V600K mutation responded remarkably to PLX4032, suggesting that clinical trials should include all patients with activating BRAF V600E/K mutations

    Tumoricidal efficacy coincides with CD11c up-regulation in antigen-specific CD8+ T cells during vaccine immunotherapy

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    Background: Dendritic cells (DCs) mount tumor-associated antigens (TAAs), and the double-stranded RNA adjuvant Poly(I:C) stimulates Toll-like receptor 3 (TLR3) signal in DC, which in turn induces type I interferon (IFN) and interleukin-12 (IL-12), then cross-primes cytotoxic T lymphocytes (CTLs). Proliferation of CTLs correlates with tumor regression. How these potent cells expand with high quality is crucial to the outcome of CTL therapy. However, good markers reflecting the efficacy of DC-target immunotherapy have not been addressed. Methods: Using an EG7 (ovalbumin, OVA-positive) tumor-implant mouse model, we examined what is a good marker for active CTL induction in treatment with Poly(I:C)/OVA. Results: Simultaneous administration of Poly(I:C) and antigen (Ag) OVA significantly increased a minor population of CD8+ T cells, that express CD11c in lymphoid and tumor sites. The numbers of the CD11c+ CD8+ T cells correlated with those of induced Ag-specific CD8+ T cells and tumor regression. The CD11c+ CD8+ T cell moiety was characterized by its high killing activity and IFN-γ-producing ability, which represent an active phenotype of the effector CTLs. Not only a TLR3-specific (TICAM-1-dependent) signal but also TLR2 (MyD88) signal in DC triggered the expansion of CD11c+ CD8+ T cells in tumor-bearing mice. Notably, human CD11c+ CD8+ T cells also proliferated in peripheral blood mononuclear cells (PBMC) stimulated with cytomegalovirus (CMV) Ag. Conclusions: CD11c expression in CD8+ T cells reflects anti-tumor CTL activity and would be a marker for immunotherapeutic efficacy in mouse models and probably cancer patients as well

    Safety Profile of Nivolumab Monotherapy: A Pooled Analysis of Patients With Advanced Melanoma.

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    Purpose We conducted a retrospective analysis to assess the safety profile of nivolumab monotherapy in patients with advanced melanoma and describe the management of adverse events (AEs) using established safety guidelines. Patients and Methods Safety data were pooled from four studies, including two phase III trials, with patients who received nivolumab 3 mg/kg once every 2 weeks. We evaluated rate of treatment-related AEs, time to onset and resolution of select AEs (those with potential immunologic etiology), and impact of select AEs and suppressive immune-modulating agents (IMs) on antitumor efficacy. Results Among 576 patients, 71% (95% CI, 67% to 75%) experienced any-grade treatment-related AEs (most commonly fatigue [25%], pruritus [17%], diarrhea [13%], and rash [13%]), and 10% (95% CI, 8% to 13%) experienced grade 3 to 4 treatment-related AEs. No drug-related deaths were reported. Select AEs (occurring in 49% of patients) were most frequently skin related, GI, endocrine, and hepatic; grade 3 to 4 select AEs occurred in 4% of patients. Median time to onset of select AEs ranged from 5 weeks for skin to 15 weeks for renal AEs. Approximately 24% of patients received systemic IMs to manage select AEs, which in most cases resolved. Adjusting for number of doses, objective response rate (ORR) was significantly higher in patients who experienced treatment-related select AEs of any grade compared with those who did not. ORRs were similar in patients who did and patients who did not receive systemic IMs. Conclusion Treatment-related AEs with nivolumab monotherapy were primarily low grade, and most resolved with established safety guidelines. Use of IMs did not affect ORR, although treatment-related select AEs of any grade were associated with higher ORR, but no progression-free survival benefit

    Workshop on challenges, insights, and future directions for mouse and humanized models in cancer immunology and immunotherapy: a report from the associated programs of the 2016 annual meeting for the Society for Immunotherapy of cancer

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    Understanding how murine models can elucidate the mechanisms underlying antitumor immune responses and advance immune-based drug development is essential to advancing the field of cancer immunotherapy. The Society for Immunotherapy of Cancer (SITC) convened a workshop titled, “Challenges, Insights, and Future Directions for Mouse and Humanized Models in Cancer Immunology and Immunotherapy” as part of the SITC 31st Annual Meeting and Associated Programs on November 10, 2016 in National Harbor, MD. The workshop focused on key issues in optimizing models for cancer immunotherapy research, with discussions on the strengths and weaknesses of current models, approaches to improve the predictive value of mouse models, and advances in cancer modeling that are anticipated in the near future. This full-day program provided an introduction to the most common immunocompetent and humanized models used in cancer immunology and immunotherapy research, and addressed the use of models to evaluate immune-targeting therapies. Here, we summarize the workshop presentations and subsequent panel discussion
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