Expression of the metastasis suppressor BRMS1 in uveal melanoma.

AIMS: To determine the expression of breast metastasis suppressor 1 (BRMS1) in human uveal melanoma (UM) tissues and cell lines. In addition, we intend to establish a possible association between BRMS1 expression and the presence of metastatic disease. METHODS: Thirty-one formalin-fixed paraffin-embedded tissues from enucleated eyes of patients with UM were immunostained. Clinical-pathological data were obtained, including age, tumour location, largest dimension, cell type, and occurrence of metastasis. The expression of BRMS1 mRNA in four human UM cell lines was determined by real-time reverse transcriptase polymerase chain reaction, and protein expression was assessed by immunocytochemistry and western blot. The association between BRMS1 immunostaining and location, largest tumour dimension, and tumour cell type was determined using the correlation coefficient test. The association between BRMS1 immunostaining and the incidence of metastasis was assessed using Kaplan-Meier analysis. RESULTS: Of the 31 cases of UM, 24 (77.42%) stained positive and seven (22.58%) negative for BRMS1. From the positively stained tumours, 21 (87.50%) showed cytoplasmatic staining. Macrophages were usually positive when present in the tumour and staining intensity was generally higher than in UM cells. BRMS1 mRNA was present in all four human UM cell lines, as well as cytoplasmatic immunoexpression of BRMS1. Immunoblotting showed variable BRMS1 protein levels between the different cell lines. No statistically significant correlation was found between BRMS1 protein expression and survival (P = 0.69), tumour cell type (P = 0.68), largest tumour dimension (P = 0.75), and tumour location (P = 0.11). CONCLUSIONS: BRMS1 is expressed in UM both at the mRNA and protein level; however, neither was associated with any of the prognosticor outcome parameters that we tested.

Case report: an atypical peripapillary uveal melanoma.

BACKGROUND: The treatment of uveal melanoma has seen a shift towards eye conserving treatments. Efforts have been made towards the identification of patients at high risk of metastatic disease with the use of prognostic fine needle biopsy, Monosomy 3 a risk factor for metastatic death thought to occur early in the development of uveal melanoma. CASE PRESENTATION: We report a case in which an atypical optic nerve lesion was found to be a peripapillary primary uveal melanoma with distinct non-pigmented and pigmented halves on gross dissection and corresponding disomy 3 and monosomy 3 halves. The tumour demonstrated rapid growth with apparent transformation from disomy 3 to monosomy 3. CONCLUSIONS: These are clinical features that challenge the current concepts of the cytogenetic pathogenesis of uveal melanoma and demonstrate the potential problems and limitations of prognostic fine needle biopsy and molecular classifications.

Ocular adverse events of molecularly targeted agents approved in solid tumours: a systematic review.

When using molecularly targeted agents (MTAs), oncologists and patients face new and sometimes unexpected toxicities. Though ocular adverse events (OAEs) are not uncommon with chemotherapy, they are rarely severe or dose limiting. Ocular toxicity profile may differ with MTAs, indeed severe and dose limiting toxicities have been described with targeted therapies currently under investigation. Our study aimed to review OAEs experienced with MTAs approved in solid tumours. This review revealed that many OAEs, frequent and potentially severe, exist and concern most MTAs. The suggestion is prompt referral of patients with severe pain and/or visual impairment to the ophthalmologist since these symptoms can be associated with potentially severe OAE and need ophthalmic assessment. Oncologists must be aware of such events and their potential severity for better treatment and better diagnosis in daily practice as well as in clinical trials.

Uveal melanoma: Ocular and systemic disease.

Although rare, uveal melanoma is the most common intraocular tumor in adults. Most cases arise from the choroidal layer of the uvea, displaying a discoid, collar-button, or mushroom shaped growth. Histopathologically, neoplasms are classified by the dominant cell type: spindle, epithelioid or mixed spindle cell type. The most important prognostic factors are cell type, nucleolar size, largest tumor dimension, and mitotic figures. Patient prognosis is poor when metastases occur in the liver, one of the main reasons that despite advances in the diagnosis and treatment of uveal melanoma, the mortality rate has not change significantly since 1973.

Immune expression and inhibition of heat shock protein 90 in uveal melanoma.

PURPOSE: To examine the immunohistochemical profile of heat shock protein 90 (Hsp90) in uveal melanoma and the cytotoxicity of an Hsp90 inhibitor, 17-allylamino-17-demethoxygeldanamycin (17-AAG), in uveal melanoma cell lines. EXPERIMENTAL DESIGN: Hsp90 expression was determined by immunohistochemistry in 44 paraffin-embedded sections of primary human uveal melanoma and in five uveal melanoma cell lines (92.1, OCM-1, MKT-BR, SP6.5, and UW-1). Sulforhodamine B-based proliferation assay was used to compare uveal melanoma cell growth with a range of concentrations of 17-AAG. Changes in cell migration, invasion, cell cycle fractions, and apoptotic activity were also evaluated. Expression of intracellular proteins was determined by Western blot analysis after 17-AAG exposure. RESULTS: Immunohistochemical expression of Hsp90 was identified in 68% of the paraffin-embedded sections and significantly associated with largest tumor dimension (P = 0.03). 17-AAG significantly reduced the proliferation rates of uveal melanoma cell lines, with concentrations of 100 to 0.1 micromol/L. 17-AAG also significantly reduced the migratory and invasive capabilities of uveal melanoma cell lines. Cell cycle analysis showed that 17-AAG induced accumulations of cells in G(1). Caspase-3 protease activity analysis, a marker for apoptosis, showed a significant increase after drug exposure. The cytotoxic effect of 17-AAG was associated with decreased levels of phosphorylated Akt and cyclin-dependent kinase 4. CONCLUSIONS: The immunohistochemical expression of Hsp90 in uveal melanoma indicates worse prognosis. To the best of our knowledge, this is the first report showing the inhibitory effect on uveal melanoma cells using 17-AAG to target Hsp90. Therefore, Hsp90 may be used as a potential target for treatment of patients with uveal melanoma.

Molecular pathways mediating liver metastasis in patients with uveal melanoma.

Uveal melanoma arises from melanocytes located in the uveal tract of the eye and is the most common primary intraocular tumor in adults. Metastatic liver disease is the overwhelming cause of death in uveal melanoma patients, with almost 50% of patients developing liver metastases up to 15 years after diagnosis. Most of these patients do not present with any evidence of overt metastasis at the time of initial diagnosis although it is assumed that they have undetectable micrometastases. Currently, there are no therapeutic modalities to prevent or efficiently treat the metastatic disease in uveal melanoma patients. Recent discoveries have shed light on the molecular pathways that may contribute to the progression of liver metastasis. The aim of this review is to describe new insights into the genetic and molecular pathways that may play a role in the development of liver metastases in uveal melanoma patients.

Cyclooxygenase-2 expression in human irradiated uveal melanomas.

AIM: Previous studies have shown that radiotherapy is a stimulus for cyclooxygenase-2 (COX-2) expression and that use of COX-2 inhibitors enhances the radio sensitivity of tumor cells. The objective of this study was to evaluate COX-2 expression, and its correlation with tumor regrowth after irradiation, in enucleated eyes with uveal melanomas. METHODS: Fifteen tissue samples from patients who underwent enucleation after radiotherapy between 1988 and 2001 were used. Nine cases (60%) were enucleated because of tumor regrowth and six (40%) because of severe complications of radiotherapy. Specimens were immunostained for COX-2, and tumor cells were evaluated for specific cytoplasmic and granular immunostaining. COX-2 expression for these cases was compared with that in the previous study including 40 non-irradiated uveal melanoma cases. COX-2 expression was also correlated with tumor regrowth after radiotherapy. RESULTS: Two cases (13.3%) were positive and thirteen (86.7%) were negative for COX-2 expression. One of the positive cases had been enucleated because of tumor regrowth and one because of radiotherapy complications. There was no relationship between tumor regrowth and COX-2 expression. COX-2 expression was significantly lower in irradiated cases than in non-irradiated cases in the previous study (p<0.001). CONCLUSIONS: In contrast with studies showing an increase of COX-2 expression in other irradiated malignancies, irradiation was not a factor inducing COX-2 in uveal melanomas. Radiotherapy may, moreover, be a factor that reduces COX-2 expression in uveal melanomas.

Expression of nm23-H1 in uveal melanoma.

Uveal melanoma (UM) is the most common malignant intraocular tumor in adults. Despite the high accuracy of clinical diagnosis and advances in local treatment, more than 50% of UM patients develop metastasis within 10 years of initial diagnosis. NM23 is one of the human metastasis suppressor genes. Reduced nm23-H1 expression is correlated with high metastatic potential in many different cancers. The purpose of this study is to investigate the expression of nm23-H1 in UM and its potential value as a prognostic marker. Immunostaining of nm23-H1 was verified in five human UM cell lines with different metastatic potentials. The expression level of nm23-H1 mRNA was evaluated with one-step quantitative real-time PCR. The invasion ability of the cell lines was assessed before and after silencing nm23-H1 with small interference RNA. Thirty-two cases of paraffin-embedded specimens of human UM were immunostained with nm23-H1 monoclonal antibody. The immunostaining was evaluated in a semiquantitative fashion based on extent and intensity. The real-time PCR results of five human UM cell lines showed that expression of nm23-H1 was higher in cell lines with low metastatic potential compared with those with high metastatic potential (P<0.05). The invasive ability of the UM cell lines increased after silencing nm23-H1 expression with small interference RNA (P<0.05). The immunostaining of nm23-H1 was cytoplasmic in all cell lines and UM patients samples. The increased immunostaining intensity of nm23-H1 in patients' samples was associated with better survival rate (Kaplan-Meier test P=0.0097). The expression of nm23-H1 was not correlated with other prognostic factors. It can be concluded that nm23-H1 may be a prognostic marker to predict the survival rate of UM patients and it has the potential to identify high-risk patients.