Identification of differentially expressed genes in uveal melanoma using suppressive subtractive hybridization.

PURPOSE: Uveal melanoma (UM) is the most common primary cancer of the eye, resulting not only in vision loss, but also in metastatic death. This study attempts to identify changes in the patterns of gene expression that lead to malignant transformation and proliferation of normal uveal melanocytes (UVM) using the Suppressive Subtractive Hybridization (SSH) technique. METHODS: The SSH technique was used to isolate genes that are differentially expressed in the TP31 cell line derived from a primary UM compared to UVM. The expression level of selected genes was further validated by microarray, semi-quantitative RT-PCR and western blot analyses. RESULTS: Analysis of the subtracted libraries revealed that 37 and 36 genes were, respectively, up- and downregulated in TP31 cells compared to UVM. Differential expression of the majority of these genes was confirmed by comparing UM cells with UVM by microarray. The expression pattern of selected genes was analyzed by semi-quantitative RT-PCR and western blot, and was found to be consistent with the SSH findings. CONCLUSIONS: We demonstrated that the SSH technique is efficient to detect differentially expressed genes in UM. The genes identified in this study represent valuable candidates for further functional analysis in UM and should be informative in studying the biology of this tumor.

Uveal melanoma: update and future directions.

In this article the author discusses advances in the treatment of ocular melanoma over the past 25 years. However, owing to metastatic disease, patient survival has not improved. Research into molecular and cellular biology and genetic factors is needed to better understand metastasis in order to improve survival.

Primary transpupillary thermotherapy for choroidal indeterminate melanocytic lesions.

OBJECTIVE: This study aimed to assess the ocular and metastatic outcomes of patients with choroidal indeterminate melanocytic lesions treated by primary transpupillary thermotherapy (TTT). DESIGN: Retrospective case series. PARTICIPANTS: Eight patients presenting choroidal indeterminate melanocytic lesions treated by primary TTT. METHODS: A retrospective chart review was conducted for patients with a newly diagnosed choroidal indeterminate melanocytic lesion treated by at least 3 TTT sessions from 2002 to 2011. Best-corrected visual acuity and lesion dimensions were measured at baseline and during follow-up. Complications were recorded including lesion growth, metastasis, melanoma-related mortality, and treatment-related complications. RESULTS: Mean initial thickness was 2.0 ± 0.8 mm. Patients had an average of 3.0 ± 0.9 risk factors for lesion growing. Three patients (38%) had lesion growth. Two patients (25%) had severe visual loss (>1.0 logMAR) directly related to TTT treatment. There were no fatalities due to metastasis. CONCLUSIONS: Despite careful patient selection and systematic treatment with at least 3 TTT sessions, the use of primary TTT to treat patients with choroidal indeterminate melanocytic lesions with ≥ 1 risk factor for lesion growth yielded poor local lesion control and the possibility for severe ocular complications.

Increased HIF-1α expression correlates with cell proliferation and vascular markers CD31 and VEGF-A in uveal melanoma.

PURPOSE: Overexpression of hypoxia inducible factor-1 α (HIF-1α) has been found in several cancers and is thought to correlate with aggressive disease. The purpose of our study was to investigate the influence of HIF-1α on clinical outcome in uveal melanoma (UM) along with proliferative (MIB-1) and vascular (CD31, VEGF-A) markers. METHODS: A retrospective analysis was carried out on UM tumors from 88 patients. HIF-1α, MIB-1, CD31, and VEGF-A expression, as well as necrosis, were assessed by immunohistochemistry and hematoxylin/eosin on paraffin-embedded UM tumor sections by using a tissue microarray. The bivariate analysis involving HIF-1α expression and clinicopathologic covariates was performed by using the χ(2) test. The association of clinicopathologic covariates and HIF-1α expression with patient survival was evaluated by using the Kaplan-Meier approach and Cox proportional-hazards regression analysis. RESULTS: Among our study population, 56 patients (63.6%) had high levels of HIF-1α expression. High expression of HIF-1α was associated with high expression of MIB-1 (P = 0.04), CD31 (P = 0.03), and VEGF-A (P < 0.0001), as well as necrosis (P = 0.04). However, high HIF-1α expression was not correlated with cell type, largest macroscopic tumor dimension or thickness, anterior margin, pigmentation, or mitotic figures. Patients with high HIF-1α expression did not show a reduced survival when compared to patients with low HIF-1α expression (P = 0.92). Finally, HIF-1α expression was not increased after irradiation. CONCLUSIONS: An increase in HIF-1α expression was significantly associated with proliferative (MIB-1) and vascular (CD31 and VEGF-A) markers, as well as necrosis, in UM. However, there was no correlation between high HIF-1α expression and patient survival.