Now showing 1 - 4 of 4
  • Publication
    Evaluation of the disease relevance and therapeutic potential of cysteinyl leukotriene receptors in uveal melanoma
    (University College Dublin. School of Biomolecular and Biomedical Science, 2022) ;
    Uveal melanoma (UM) is a rare, ocular cancer that arises from melanocytes within the uveal tract. This cancer imposes the threat of visual impairment, ocular pain, enucleation, and in half of all cases, death from metastatic disease. Approximately 50% of UM patients will develop metastases, which occur most frequently in the liver. Despite advances in control of the primary tumour, there is currently no approved therapy that can prevent or halt the growth of UM metastases. The prognosis for metastatic UM patients is extremely poor; the median overall survival is approximately 13.4 months, with as few as 8% of patients surviving beyond 2 years. Recent reports suggest that Ireland has one of the highest incidence rates in the world, with an average of 45 new cases diagnosed annually. The development of therapies that can prolong the life of UM patients is an area of urgent unmet need. This research evaluates the clinical relevance and therapeutic potential of cysteinyl leukotriene receptors (CysLT1 and CysLT2) in UM. The cysteinyl leukotrienes (CysLTs) are a group of inflammatory, lipid mediators that signal through G-protein couple receptors, CysLT1 and CysLT2. The role of CysLT receptor expression, and signalling, in several cancers has recently emerged. This, coupled with the identification of an oncogenic mutation in CYSLTR2 in a subset of UM patients, led us to hypothesise that these receptors could be targeted therapeutically in the disease. We have shown that high expression of CYSLTR1 and CYSLTR2 are significantly associated with reduced disease-free survival and reduced overall survival in UM patients. The expression of both receptors was further investigated by IHC. In two, independent patient cohorts we validated that high expression of CysLT1 is significantly associated with reduced overall survival. These findings solidified the importance of CysLT receptor expression in UM and its link to patient outcomes. As CysLT receptors are druggable targets, we hypothesised that pharmacological antagonists may attenuate cancer phenotypes including viability, proliferation, angiogenesis, inflammation, and metabolism, of UM cells in culture. We found that CysLT1 antagonists, but not CysLT2 antagonist, HAMI 3379, produced significant anti-cancer effects in primary and metastatic UM cell lines through the inhibition of cell survival and cell proliferation. Novel CysLT1 antagonists, quininib and 1,4-dihydroxy quininib, produce cell line-dependent effects on the cancer secretome of UM cell lines. In terms of metabolism, CysLT1 antagonists significantly reduce oxidative phosphorylation in primary and metastatic UM cells. We sought to validate our findings in in vivo and ex vivo preclinical models of UM. In zebrafish cell line-derived xenograft models, CysLT1 antagonists significantly inhibit the growth of primary and metastatic cell lines in vivo and have a greater effect in zebrafish ocular orthoxenograft models. In a cell line-derived orthotopic rodent xenograft model of metastatic UM, treatment with CysLT1 antagonist, 1,4-dihydroxy quininib, did not significantly decrease tumour weight versus vehicle control but did decrease tumour weight and expression of Ki-67, a marker of proliferation, versus standard-of-care, dacarbazine. 1,4-dihydroxy quininib significantly decreases ATP5B, a marker of oxidative phosphorylation, versus vehicle, mimicking our in vitro data. Treatment of UM ex vivo explants derived from primary UM with 1,4-dihydroxy quininib significantly alters the secretion of inflammatory mediators in the tumour microenvironment. The secretion of IL-13, IL-2 and TNF-a was significantly increased following treatment of primary UM tumours for 72 hours. These preclinical data strengthen the importance of CysLT signalling in UM. Our findings suggest that high expression of CysLT1 in UM could act as a biomarker and that antagonism of CysLT1 may be of therapeutic interest in the treatment of UM.
  • Publication
    Uveal Melanoma Cell Line Proliferation Is Inhibited by Ricolinostat, a Histone Deacetylase Inhibitor
    Metastatic uveal melanoma (MUM) is characterized by poor patient survival. Unfortunately, current treatment options demonstrate limited benefits. In this study, we evaluate the efficacy of ACY-1215, a histone deacetylase inhibitor (HDACi), to attenuate growth of primary ocular UM cell lines and, in particular, a liver MUM cell line in vitro and in vivo, and elucidate the underlying molecular mechanisms. A significant (p = 0.0001) dose-dependent reduction in surviving clones of the primary ocular UM cells, Mel270, was observed upon treatment with increasing doses of ACY-1215. Treatment of OMM2.5 MUM cells with ACY-1215 resulted in a significant (p = 0.0001), dose-dependent reduction in cell survival and proliferation in vitro, and in vivo attenuation of primary OMM2.5 xenografts in zebrafish larvae. Furthermore, flow cytometry revealed that ACY-1215 significantly arrested the OMM2.5 cell cycle in S phase (p = 0.0001) following 24 h of treatment, and significant apoptosis was triggered in a time-and dose-dependent manner (p < 0.0001). Additionally, ACY-1215 treatment resulted in a significant reduction in OMM2.5 p-ERK expression levels. Through proteome profiling, the attenuation of the microphthalmia-associated transcription factor (MITF) signaling pathway was linked to the observed anti-cancer effects of ACY-1215. In agreement, pharmacological inhibition of MITF signaling with ML329 significantly reduced OMM2.5 cell survival and viability in vitro (p = 0.0001) and reduced OMM2.5 cells in vivo (p = 0.0006). Our findings provide evidence that ACY-1215 and ML329 are efficacious against growth and survival of OMM2.5 MUM cells.
      123Scopus© Citations 13
  • Publication
    Discovery and Development of the Quininib Series of Ocular Drugs
    The quininib series is a novel collection of small-molecule drugs with antiangiogenic, antivascular permeability, anti-inflammatory, and antiproliferative activity. Quininib was initially identified as a drug hit during a random chemical library screen for determinants of developmental ocular angiogenesis in zebrafish. To enhance drug efficacy, novel quininib analogs were designed by applying medicinal chemistry approaches. The resulting quininib drug series has efficacy in in vitro and ex vivo models of angiogenesis utilizing human cell lines and tissues. In vivo, quininib drugs reduce pathological angiogenesis and retinal vascular permeability in rodent models. Quininib acts as a cysteinyl leukotriene (CysLT) receptor antagonist, revealing new roles of these G-protein-coupled receptors in developmental angiogenesis of the eye and unexpectedly in uveal melanoma (UM). The quininib series highlighted the potential of CysLT receptors as therapeutic targets for retinal vasculopathies (e.g., neovascular age-related macular degeneration, diabetic retinopathy, and diabetic macular edema) and ocular cancers (e.g., UM).
  • Publication
    Evaluation of oncogenic cysteinyl leukotriene receptor 2 as a therapeutic target for uveal melanoma
    Uveal melanoma is a rare, but deadly, form of eye cancer that arises from melanocytes within the uveal tract. Although advances have emerged in treatment of the primary tumour, patients are still faced with vision loss, eye enucleation and lethal metastatic spread of the disease. Approximately 50% of uveal melanoma patients develop metastases, which occur most frequently in the liver. Metastatic patients encounter an extremely poor prognosis; as few as 8% survive beyond 2 years. Understanding of the genetic underpinnings of this fatal disease evolved in recent years with the identification of new oncogenic mutations that drive uveal melanoma pathogenesis. Despite this progress, the lack of successful therapies or a proven standard-of-care for uveal melanoma highlights the need for new targeted therapies. This review focuses on the recently identified CYSLTR2 oncogenic mutation in uveal melanoma. Here, we evaluate the current status of uveal melanoma and investigate how to better understand the role of this CYSLTR2 mutation in the disease and implications for patients harbouring this mutation.
    Scopus© Citations 21  829