A human uveal melanoma cell line (92-1) was established from a primary uveal melanoma, and has now been maintained in culture for over 2 1/2 years. Light microscopy of the cultured cells demonstrated extremely pleiomorphic cells with large prominent nucleoli. Cell proliferation was determined with a non-radioactive propidium-iodide assay and indicated an in vitro doubling time of approximately 58 hr. Furthermore, the cell line was characterized by cytogenetic analysis, electron microscopy, immunocytochemistry and Northern blotting for HLA and c-myc-mRNA analysis. Cytogenetic analysis revealed numerical abnormalities of chromosome 8 and structural abnormalities of chromosome 6. By electron microscopy, different stages of melanosome development were observed. Immunocytochemical analysis demonstrated expression of the melanoma-associated antigen gp 100. Expression analysis of HLA antigens revealed a very low level of, in particular, the HLA-B locus products, which could be induced by interferon-alpha or -gamma treatment. Likewise, Northern-blot experiments revealed decreased levels of HLA-B mRNA as compared with HLA-A. In addition, high levels of c-myc expression were observed. The phenotypic characteristics of the cultured cells indicate that we have established an uveal melanoma cell line. This now well-characterized uveal melanoma cell line can be used in future studies.

Background-The level of HLA expression on a tumour may influence the immunological response against this tumour, and vice versa. HLA expression was determined in a primary uveal melanoma, its metastases, and on a cell line derived from this melanoma, and the presence and type of infiltrate in tissue sections were also studied. (Br J Ophthalmol 1997;81:989-993) Changes in HLA expression often occur during carcinogenesis. Methods-Immunohistochemistry1 Since the function of cytotoxic T lymphocytes (CTLs), as well as of natural killer (NK) cells, is directly influenced by expression of HLA class I antigens, 2 3 changes in HLA class I expression might influence an antitumour immune response, and, therefore, prognosis. An association between HLA class I expression and prognosis was observed, for instance, in larynx and breast carcinomas: a lack of HLA class I expression correlated with a more aggressive tumour behaviour and a worse prognosis. 4 In skin melanoma, the transformation of normal skin melanocytes to melanoma cells is frequently accompanied by a decreased expression of HLA class I antigens, 5 and complete or selective loss of expression of HLA class I has been observed more frequently in metastatic compared with primary skin melanomas.6 Van Duinen et al showed an association between lack of HLA class I expression in locoregional metastases and poor prognosis in patients with stage II cutaneous melanoma. 7Although several authors have studied the expression of monomorphic, [8][9][10] and polymorphic HLA class I and/or II expression in primary uveal melanomas, 11 data on HLA expression on metastases of uveal melanoma are still scarce. To our knowledge, only one such study has been performed, in which HLA class I expression was studied on a culture derived from a primary uveal melanoma and on two separate cell cultures derived from liver metastases of the same patient. 12 In Tran et al's report, it was concluded that both primary and metastatic tumour cells expressed HLA class I.In the present study, we determined the level of expression of HLA class I and II molecules on a primary intraocular melanoma, on four of its metastases, and on a cell line obtained from the primary tumour. The presence of tumour infiltrating cells in these lesions was also assessed, and compared with the expression of the HLA antigens. Materials and methods CLINICAL AND HISTOPATHOLOGICAL FINDINGSThe patient was a 76-year-old woman referred to the department of ophthalmology of Leiden University Hospital with a large tumour in the right orbit extending from the eye (largest tumour diameter 20 mm). On examination, the visual acuity of the right eye was 0 and the best corrected visual acuity of the left eye was 0.3. The right eyeball had been displaced superotemporally by a large tumour, and vessel growth was observed throughout the eyeball. With the exception of a cortical cataract, the left eye showed no abnormalities. Computed tomography of the right orbit revealed a small and deformed eyeball with tumour outgrowth into orb...

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Background-Uveal melanoma is a tumour with a high incidence of metastasis and a high mortality rate. Additional therapies to obtain a better local control or an effective treatment ofmetastases are necessary. Interferons may be applied. Methods (Br_J Ophthalmol 1995; 79: 847-855) In recent years the anti-tumour activities of interferons (IFNs) have been studied extensively. Promising therapeutic results have been reported, especially in the treatment of haematological malignancies. 1-3 IFNs may also be of importance in the therapy of high risk cutaneous melanoma4 5 although the results are variable. However, the exact mechanisms of the anti-tumour activities of IFNs (immunomodulatory or antiproliferative) are still unknown and it is impossible to predict which patients may benefit most from IFN treatment. With regard to the potential immunomodulatory effect, IFNs are able to modulate the expression of cell surface molecules such as HLA class I and class II antigens.6 These molecules are essential in the generation and regulation of an effective antitumour immune response by T cells, since tumour specific antigens can only be recognised by T lymphocytes when the antigens are presented in the groove of HLA molecules. Since allele specific binding of tumour specific antigens has been reported -for example, for human cutaneous melanoma,7-9 differences in the level of different HLA molecules might be important in the development of effective antitumour immune responses.In a previous study, we determined the expression of HLA class I and II antigens on frozen tissue sections of uveal melanoma. Differences in the level of expression of different HLA molecules were observed: HLA-B antigens showed a lower level of expression than HLA-A.10 This low level of allele specific HLA class I expression might effect a putative anti-tumour immune response in vivo. Based on these results we hypothesised that HLA molecules on uveal melanoma cells in vitro might be sensitive to IFN mediated upregulation of expression.

This is the first Delphi consensus study identifying exact conditions that junior doctors must be able to prescribe for. The essential diseases can be used for training in prescribing and assessment of junior doctors' prescribing competence.