Uveal melanoma (UM) is a rare ocular tumor. Up to 50% of the patients develop distant metastases predominantly targeting the liver. The median survival after diagnosis of patients with hepatic... Show moreUveal melanoma (UM) is a rare ocular tumor. Up to 50% of the patients develop distant metastases predominantly targeting the liver. The median survival after diagnosis of patients with hepatic metastases is approximately 4-6 months and hardly increased in the past decades due to lack of novel effective therapeutic options. Within the scope of this thesis we investigated the signaling landscape of metastatic UM and searched for novel avenues of therapy. In Chapter 2 we demonstrate that combinations of the multitarget drug Trabectedin with either the CK2/Clk double-inhibitor Silmitasertib or with the c-MET/TAM receptor inhibitors show synergistic growth inhibitory effects and induce apoptosis of UM cells in vitro. Chapter 3 describes the application of a CRISPR-Cas9 synthetic lethality screen for identification of molecular targets whose inhibition synergistically enhances the effect of the mTOR inhibitor everolimus in UM cells. In Chapter 4 we show that the combination of genetic depletion YAP1/TAZ together with Mcl-1 inhibition resulted in a synergistic inhibitory effect on the viability of UM cell lines. In Chapter 5 we analyzed the phospho-proteome of two UM metastatic cell lines and a primary tumor cell line from the same individual, and studied the role of MARK3 in YAP1/TAZ signaling. Show less
PurposeHeavy pigmentation is known to be a prognostic risk factor in uveal melanoma (UM). We analyzed whether genetic tumor parameters were associated with tumor pigmentation and whether... Show morePurposeHeavy pigmentation is known to be a prognostic risk factor in uveal melanoma (UM). We analyzed whether genetic tumor parameters were associated with tumor pigmentation and whether pigmentation should be included in prognostic tests.DesignRetrospective comparison of clinical, histopathological, and genetic features and survival in UM with different pigmentation.ParticipantsA total of 1058 patients with UM from a White European population with diverse eye colors enucleated between 1972 and 2021.MethodsCox regression and log-rank tests were used for survival analysis; the chi-square test and Mann–Whitney U test were used for correlation analysis.Main Outcome MeasuresUveal melanoma–related survival based on tumor pigmentation and chromosome status, correlation of tumor pigmentation with prognostic factors.ResultsThe 5-year UM-related mortality was 8% in patients with nonpigmented tumors (n = 54), 25% with lightly pigmented tumors (n = 489), 41% with moderately pigmented tumors (n = 333), and 33% with dark tumors (n = 178) (P < 0.001). The percentage of tumors with monosomy 3 (M3) or 8q gain increased with increasing pigmentation (31%, 46%, 62%, and 70% having M3 [P < 0.001], and 19%, 43%, 61%, and 63% having 8q gain [P < 0.001] in the 4 increasing pigment groups, respectively). BRCA-associated protein 1(BAP1) loss (known for 204 cases) was associated with increased tumor pigmentation (P = 0.001). Cox regression analysis on survival showed that when chromosome status and pigmentation were both included, pigmentation was not an independent prognostic indicator. Preferentially expressed antigen in melanoma (PRAME) expression was a significant prognostic marker in light tumors (P = 0.02) but not in dark tumors (P = 0.85).ConclusionsPatients with moderately and heavily pigmented tumors showed a significantly higher UM-related mortality than patients with unpigmented and light tumors (P < 0.001), supporting prior reports on the relation between increased tumor pigmentation and a worse prognosis. Although we previously showed that a dark eye color was associated with tumor pigmentation, we now show that the tumor’s genetic status (chromosome 3 and 8q/BAP1 status) is also related to tumor pigmentation. When pigmentation and chromosome 3 status are both included in a Cox regression analysis, pigmentation is not an independent prognostic factor. However, evidence from this and previous studies shows that chromosome changes and PRAME expression have a stronger association with survival when they occur in light tumors than in dark ones. Show less
Ocular manifestations are observed in approximately one third of all inherited metabolic disorders (IMDs). Although ocular involvement is not life-threatening, it can result in severe vision loss,... Show moreOcular manifestations are observed in approximately one third of all inherited metabolic disorders (IMDs). Although ocular involvement is not life-threatening, it can result in severe vision loss, thereby leading to an additional burden for the patient. Retinal degeneration with or without optic atrophy is the most frequent phenotype, followed by oculomotor problems, involvement of the cornea and lens, and refractive errors. These phenotypes can provide valuable clues that contribute to its diagnosis. In this issue we found 577 relevant IMDs leading to ophthalmologic manifestations. This article is the seventh of a series attempting to create and maintain a comprehensive list of clinical and metabolic differential diagnoses according to system involvement. (C) 2022 The Authors. Published by Elsevier Inc. Show less
Groot, V. de; Verhelst, E.; Hogendoorn, P.C.W.; Keizer, R.J.W. de 2019
This thesis describes several topics on angiogenesis and screening in uveal melanoma, the most frequent eye tumour in adults. The expression of vascular endothelial growth factor and other... Show moreThis thesis describes several topics on angiogenesis and screening in uveal melanoma, the most frequent eye tumour in adults. The expression of vascular endothelial growth factor and other angiostimulating factors in this tumour are described. In a second part, the use of different screening tests in screening for metastases of uveal melanoma is investigated. Show less
