[A man with nasal bleedings and blurry vision]. / Een man met neusbloedingen en wazig zicht.

A 67-year-old man, experiencing nasal bleedings and shortness of breath for months, had a blurry vision for a few days. Bone marrow biopsy and laboratory findings led to the diagnosis of Waldenström's macroglobulinaemia. Fundoscopy showed cotton wool spots and retinal haemorrhages, associated with Waldenström's retinopathy. Plasmapheresis improved both vision and retinal abnormalities.

Monosomy of chromosome 3 and an inflammatory phenotype occur together in uveal melanoma.

PURPOSE: In uveal melanoma, different predictors of poor prognosis have been identified, including monosomy of chromosome 3, HLA expression, and the presence of infiltrating leukocytes and macrophages. Each of these parameters can be used to differentiate prognostically the favorable tumors from the unfavorable ones, and thus the hypothesis for the present study was that they are related, and that monosomy of chromosome 3 occurs in the same tumors as the unfavorable inflammatory phenotype. METHODS: Tumor tissue was obtained from 50 cases of uveal melanoma treated between 1999 and 2004. After enucleation, nuclei were isolated from paraffin-embedded tissue for fluorescence in situ hybridization, to determine the chromosome 3 copy number. Each tumor-containing globe was further processed for conventional histopathologic examination and for immunohistochemical analysis with HLA class I and II-specific antibodies and with macrophage marker CD68. RESULTS: Of 50 uveal melanomas, 62% (31/50) were categorized as having monosomy of chromosome 3. Monosomy 3 was associated with the presence of epithelioid cells, an increased density of tumor-infiltrating macrophages, and a higher HLA class I and II expression. Survival analyses showed a correlation between monosomy 3 and decreased survival and identified monosomy 3, ciliary body involvement, and largest basal tumor diameter as the best prognostic markers. CONCLUSIONS: Monosomy 3 in uveal melanoma is associated with the presence of an inflammatory phenotype, consisting of a high HLA class I and II expression as well as an increased number of tumor-infiltrating macrophages. In a multivariate Cox regression analysis, the presence of monosomy 3 was one of the best prognostic markers of metastatic disease and survival, although the follow-up time was short.

Epigenetic regulation identifies RASEF as a tumor-suppressor gene in uveal melanoma.

PURPOSE: Recently, a segregation study in families with uveal and cutaneous melanoma identified 9q21 as a potential locus harboring a tumor-suppressor gene (TSG). One of the genes in this area, RASEF, was then analyzed as a candidate TSG, but lack of point mutations and copy number changes could not confirm this. In this study, the RASEF gene was investigated for potential mutations and gene silencing by promoter methylation in uveal melanoma. METHODS: Eleven uveal melanoma cell lines and 35 primary uveal melanoma samples were screened for mutations in the RASEF gene by high-resolution melting-curve and digestion analysis. Expression of RASEF was determined by real-time RT-PCR in all cell lines and 16 primary uveal melanoma samples, and the methylation status of the promoter of the RASEF gene was analyzed and confirmed by direct sequencing. RESULTS: Mutation screening revealed a known polymorphism (R262C; C-->T) in exon 5 of the RASEF gene that displayed a normal frequency (54%). Of the primary uveal melanomas, 46% presented a heterozygous genotype, and 10 (91%) of 11 cell lines showed a homozygous genotype. Melting-curve analysis indicated loss of heterozygosity in at least two primary tumors. Low RASEF expression in the cell lines and primary tumors correlated with methylation of the RASEF promoter region. Homozygosity and methylation of the RASEF gene in primary tumors were associated with decreased survival (P = 0.019). CONCLUSIONS: Homozygosity, in combination with methylation, appears to be the mechanism targeting RASEF in uveal melanoma, and allelic imbalance at this locus supports a TSG role for RASEF.

Pyrophosphorolysis detects B-RAF mutations in primary uveal melanoma.

PURPOSE: Mutations in the genes that control cell proliferation in cutaneous melanoma are generally uncommon in uveal melanoma. Despite the absence of known activating mutations, the RAF-MEK-ERK, or mitogen-activated protein kinase (MAPK), pathway is usually activated in uveal melanoma. An assay with increased potential to identify mutations is now available, and this study was therefore conducted to reanalyze uveal melanoma cell lines and primary tumors for this mutation. METHODS: Eleven uveal melanoma cell lines and 45 primary uveal melanomas were analyzed for mutations in exon 15 of the B-RAF gene by using pyrophosphorolysis-activated polymerization (PAP). Mutations were validated by sequencing of the PAP product. RESULTS: B-RAF mutations were detected in cell lines OCM-1 and -3 (V600E) and in six primary uveal melanomas. The V600K mutation was detected in one primary uveal melanoma, for which the V600E assay turned out to be sensitive as well. Direct sequencing of the exon 15 PCR product did not reveal the mutations found with the PAP-assay, indicating a low frequency of the mutant allele in primary samples. CONCLUSIONS: Because of the very sensitive PAP technology, B-RAF mutations were found in cell lines and primary uveal melanomas, which suggests that they may occasionally play a role in the activation of the MAPK pathway in uveal melanoma and indicates a higher prevalence of B-RAF mutations in uveal melanoma than was reported earlier. However, the relative scarcity of the B-RAF mutation excludes an elemental role for this mutation in uveal melanoma.

Triamcinolone acetonide and anecortave acetate do not stimulate uveal melanoma cell growth.

PURPOSE: Radiotherapy-induced radiation retinopathy can develop in over 40% of eyes treated for uveal melanoma. Triamcinolone acetonide (TA) and anecortave acetate (AA) can be used to treat radiation retinopathy. It is not known whether TA or AA has any effect on potentially still viable uveal melanoma cells in the choroid after radiotherapy. We therefore studied the effect of these drugs on the proliferation of uveal melanoma cell lines in vitro. Furthermore, as these drugs are supposed to counteract vascular leakage, we determined their effect on the expression and production of the proangiogenic vascular endothelial growth factor-A (VEGF-A), the antiangiogenic pigment epithelium-derived factor (PEDF), and thrombospondin-1 (TSP-1) in uveal melanoma cells. METHODS: Three uveal melanoma cell lines were treated in vitro with TA or AA. Cell proliferation was measured by counting cells and using the Water-Soluble Tetrazolium Salt-1 (WST-1) assay. VEGF-A and PEDF production was measured by ELISA, and intracellular expression of angiogenic-associated genes including VEGF-A, PEDF, and TSP-1 was determined by real-time quantitative RT-PCR. RESULTS: We found no effect of TA or AA on tumor cell growth or production of VEGF-A and PEDF in any of the three uveal melanoma cell lines tested. Regarding expression as measured by RT-PCR, TA had an inhibiting effect on TSP-1 in only one cell line, and no effect on VEGF-A or PEDF. AA showed a similar lack of effect. CONCLUSIONS: Since TA and AA do not stimulate uveal melanoma cell growth, it seems to be safe to use these drugs to treat radiation retinopathy after irradiation for uveal melanoma. Additional experiments using more cell lines or primary tumor cell cultures are needed to validate this conclusion. Furthermore, the results of our study suggest that TA does not exert its antileakage effect through downregulation of VEGF-A or upregulation of TSP-1 or PEDF in uveal melanoma cell lines. It is possible that TA and AA influence these pro- and antiangiogenic factors only under hypoxic circumstances. Further investigation is needed.

Epigenetic inactivation of RASSF1a in uveal melanoma.

PURPOSE: The RAS association domain family 1 (RASSF1) gene is a tumor-suppressor gene located on chromosome 3p21.3. The alternative transcript (RASSF1a) has been shown to be inactivated by hypermethylation in several human malignancies, including breast, prostate, and lung cancer, and in cutaneous melanoma. The purpose of this study was to evaluate the methylation status of RASSF1a in human uveal melanoma. METHODS: The methylation status of the RASSF1a promoter region was analyzed using PCR in combination with melting curve analysis, sequencing, and restriction enzyme analysis. Eleven human uveal melanoma cell lines, normal melanocytes, 39 archival frozen tumor specimens, and a metastatic lesion of untreated primary uveal melanoma were studied. In addition, whether RASSF1a methylation correlates with patient survival and development of metastatic disease was investigated. RESULTS: RASSF1a promoter methylation was detected in 10 of the 11 (91%) cell lines, in 19 of the 38 (50%) patients with primary uveal melanoma and in the metastatic lesion. A positive correlation was found between RASSF1a promoter methylation and development of metastatic disease (P = 0.041). A correlation with disease-free survival could not be established, but a positive trend was observed (P = 0.063). CONCLUSIONS: These data show that RASSF1a methylation is a common epigenetic event in uveal melanoma development, potentially of clinical relevance. The presence of a methylated RASSF1a promoter region might therefore serve as a tumor marker and as a possible target for therapeutic intervention.

Expression of Wnt5a and its downstream effector beta-catenin in uveal melanoma.

Upregulation of the Wnt5a pathway has been reported in some cutaneous melanomas but its role in uveal melanoma has not been assessed. We thus sought to determine whether activation of the Wnt-signalling pathway occurred in uveal melanoma through upregulation of some of the key downstream effectors, and whether expression of these components was associated with tumour characteristics and clinical outcome. Expression of Wnt5a, MMP7, and beta-catenin was determined in 40 primary uveal melanomas by immunohistochemistry and correlated with patient prognosis. The proportion of cells immunoreactive for Wnt5a, MMP7, and beta-catenin was higher in tumours from patients with shorter survival and this difference was statistically significant for Wnt5a (P<0.01) and beta-catenin (P=0.02). These data show for the first time activation of the Wnt/beta-catenin-signalling pathway in uveal melanoma and suggest that components of this pathway might be useful prognostic markers as well as attractive therapeutic targets to treat this disease.

HLA Class I and II genotype in uveal melanoma: relation to occurrence and prognosis.

PURPOSE: To assess whether human leukocyte antigen class I and class II alleles confer susceptibility to uveal melanoma or are related to specific clinical or tumor characteristics and survival. METHODS: Between 1990 and 2004, 235 consecutive Dutch patients with diagnoses of primary uveal melanoma were typed for HLA class I and II, either by complement-dependent cytotoxicity test or by DNA-based technique. Allele frequencies were compared with those of a control group that consisted of 2440 healthy Dutch blood donors. In addition, allele frequencies of 138 patients with uveal melanoma, who underwent enucleation as primary treatment, were compared for tumor characteristics and survival. RESULTS: With regard to tumor characteristics, correlations between HLA-DR13 and tumor size, HLA-B35 and spindle cell type, and HLA-B60 and ciliary body involvement were observed before correction for the number of alleles tested. Correlation was found between the presence of HLA-B44 and decreased survival. We did not find any allele that correlated with susceptibility to uveal melanoma after correction for the number of comparisons between patients and controls. CONCLUSIONS: This study shows that HLA class I and II antigens do not contribute to an increased genetic susceptibility to uveal melanoma. This does not exclude an important role for HLA antigens in immune surveillance against uveal melanoma and their metastases.

A comparison of HLA genotype with inflammation in uveal melanoma.

PURPOSE: Human leukocyte antigen (HLA) polymorphisms have been associated with the development of autoimmune diseases. In uveal melanoma, a high expression of HLA classes I and II, and infiltration with lymphocytes and macrophages are associated with a bad prognosis. Inflammation has an important role in this malignancy. The goal of our study was to determine whether specific HLA alleles are associated with increased inflammation. METHODS: Records were analyzed of 45 patients who underwent enucleation for uveal melanoma. HLA typing, tumor HLA expression and tumor macrophage infiltration were determined in each case. RESULTS: Before correction for multiple testing, macrophage infiltration was less in HLA-A2 positive patients. Patients with HLA-DR6 had a higher tumor cell expression of HLA-DR. After correction for the number of analyses, no associations remained statistically significant. CONCLUSION: The results before correction suggest that the HLA genotype may influence inflammation as indicated by HLA expression and macrophage infiltration in uveal melanoma. However, after correction this association did not prove significant.

Effect of heterogeneous distribution of monosomy 3 on prognosis in uveal melanoma.

CONTEXT: Fluorescence in situ hybridization (FISH) analyses on tumor sections and on isolated nuclei showed that even low numbers of cells with monosomy of chromosome 3 adversely affected survival. OBJECTIVE: To determine what percentage of uveal melanoma cells with monosomy of chromosome 3 influences patient mortality. DESIGN: To determine the presence of monosomy 3, karyotyping and FISH on cultured cells and FISH on isolated nuclei were performed on 50 primary uveal melanomas. Clinical and pathologic prognostic factors were assessed and compared with 5-year survival data. Analyses were performed using Cox proportional hazards test, log-rank analysis, sensitivity, specificity, and positive and negative likelihood ratios. RESULTS: Combined karyotyping and FISH on cultured cells showed monosomy 3 in 19 of 50 cases (38%), whereas determination of the monosomy 3 status by FISH on isolated nuclei with a threshold of 5% assigned 31 of 50 cases (62%) to the monosomy-3 category. When monosomy 3 on isolated nuclei with a cutoff value of 5% was used, a significant difference in 5-year survival was present (hazard ratio, 15.5; P = .007), indicating that monosomy 3 in greater than 5% of tumor cells is related to death due to metastases. CONCLUSION: In uveal melanoma, the presence of greater than 5% of cells with monosomy 3, as determined by FISH on isolated nuclei, is associated with the development of metastases within 5 years after enucleation.

Regulation of VEGF-A in uveal melanoma.

PURPOSE: Blood vessels are important constituents of intraocular uveal melanoma (UM), but whether angiogenesis is regulated by environmental factors such as ischemia or by genetic mechanisms is not known. This study was undertaken to examine the regulation of the proangiogenic factor vascular endothelial growth factor (VEGF-A). METHODS: Cell lines and primary tumors were tested for expression of VEGF-A, under normoxic and hypoxic conditions, using quantitative PCR, ELISA, WST-1 viability, and in-cell Western experiments. VEGF-A serum levels were determined by ELISA. RESULTS: Hypoxia induced expression of HIF-1alpha and VEGF-A in UM cell lines and primary tumor cultures, but it did not influence proliferation. VEGF-A expression in primary tumors was variable, demonstrating no correlation with specific histologic markers or prognosis. However, VEGF-A levels were significantly raised in UM patients with metastases compared with those without metastases (P < 0.001). CONCLUSIONS: VEGF-A expression by UM cells is mainly controlled by hypoxia and involves the HIF-1alpha pathway, thus indicating an important role for the tumor cell environment. Metastases led to increased serum VEGF-A levels, indicating that VEGF-A may be involved in the growth of metastases.

Evidence for natural killer cell-mediated protection from metastasis formation in uveal melanoma patients.

PURPOSE: In uveal melanoma, low human leukocyte antigen (HLA) class I expression on primary tumors is associated with a decreased risk of metastasis. Consequently, it has been suggested that natural killer (NK) cells, which detect decreased expression of HLA class I, are involved in the immune control of metastases. In this study, three novel lines of evidence were identified that support a role for NK cells. METHODS: Uveal melanoma cell lines were used to determine the expression of NK cell receptor ligands (MICA, MICB, ULBP1-3, CD112, CD155, and HLA class I) and to examine sensitivity to lysis by human NK cell lines. Because interactions between polymorphic killer immunoglobulin receptors (KIRs) and HLA regulate NK cell function, KIR and HLA genotyping was performed on 154 patients with uveal melanoma and 222 healthy control subjects. RESULTS: First, all 11 uveal melanoma cell lines tested expressed ligands for activating as well as inhibitory NK cell receptors. Second, such cell lines were lysed efficiently by human NK cells in vitro. Finally, the HLA-C genotype was related to the risk of metastasis-related death in patients with uveal melanoma: The patients carrying HLA-C alleles encoding ligands for KIR2DL1 and KIR2DL2/3 (HLA-C group 1/group 2 heterozygous patients), both inhibitory NK receptors, had a longer metastasis-free survival than did those carrying HLA-C ligands for either KIR2DL1 (HLA-C group 2 homozygotes) or KIR2DL2/3 (HLA-C group 1 homozygotes). CONCLUSIONS: Together, the data support a role for NK cells in the prevention of uveal melanoma metastases.

The heterogeneous distribution of monosomy 3 in uveal melanomas: implications for prognostication based on fine-needle aspiration biopsies.

CONTEXT: The detection of monosomy 3 in uveal melanomas has repeatedly been associated with adverse outcome. Fine-needle aspiration biopsy is being used to detect monosomy 3 in these tumors, based on the assumption that this chromosomal abnormality is distributed homogeneously throughout the tumor. OBJECTIVE: To study the distribution of monosomy 3 in primary uveal melanoma by fluorescence in situ hybridization (FISH). DESIGN: We studied 50 enucleated eyes with uveal melanoma. In all 50 tumors we performed cytogenetic analysis and FISH using a DNA-specific probe for the centromere region of chromosome 3 on cultured tumor cells. In addition, the percentage of tumor cells with monosomy 3 was assessed by FISH on nuclei, isolated from paraffin-embedded tissue and compared to results of FISH on regular histology sections of the paraffin-embedded tissue. RESULTS: Combining karyotyping and FISH on cultured cells identified monosomy 3 in 19 (38%) of 50 tumors, whereas FISH on nuclei isolated from paraffin-embedded tissue showed 31 (62%) of 50 as having monosomy for chromosome 3. FISH analysis on paraffin sections showed tumor heterogeneity for copy number of chromosome 3 in at least 7 cases. CONCLUSIONS: FISH analysis on paraffin sections shows that heterogeneity of monosomy of chromosome 3 is a frequent phenomenon in uveal melanoma. FISH on nuclei isolated from paraffin-embedded tissue identifies a higher frequency of monosomy 3 than the traditional combination of karyotyping and FISH on cultured uveal melanoma cells. The practice of assigning patients to risk categories based on fine-needle aspiration biopsy samples from primary uveal melanoma may be subject to error based on the heterogeneous distribution of monosomy 3 in these tumors.