Purpose:To compare a gene expression^based classifier versus the standard genetic prognostic marker, monosomy 3, for predicting metastasis in uveal melanoma. Experimental Design: Gene expression profiling, fluorescence in situ hybridization (FISH), and array comparative genomic hybridization (aCGH) were done on 67 primary uveal melanomas. Clinical and pathologic prognostic factors were also assessed. Variables were analyzed by Cox proportional hazards, Kaplan-Meier analysis, sensitivity, specificity, positive and negative predictive value, and positive and negative likelihood ratios. Results: The gene expression^based molecular classifier assigned 27 tumors to class 1 (low risk) and 25 tumors to class 2 (high risk). By Cox univariate proportional hazards, class 2 signature (P = 0.0001), advanced patient age (P = 0.01), and scleral invasion (P = 0.007) were the only variables significantly associated with metastasis. Only the class 2 signature was needed to optimize predictive accuracy in a Cox multivariate model. A less significant association with metastasis was observed for monosomy 3 detected by aCGH (P = 0.076) and FISH (P = 0.127). The sensitivity and specificity for the molecular classifier (84.6% and 92.9%, respectively) were superior to monosomy 3 detected by aCGH (58.3% and 85.7%, respectively) and FISH (50.0% and 72.7%, respectively). Positive and negative predictive values (91.7% and 86.7%, respectively) and positive and negative likelihood ratios (11.9 and 0.2, respectively) for the molecular classifier were also superior to those for monosomy 3. Conclusions: Molecular classification based on gene expression profiling of the primary tumor was superior to monosomy 3 and clinicopathologic prognostic factors for predicting metastasis in uveal melanoma.In recent years, there has been increasing interest in individualized management of cancer patients based on predictive molecular testing (1, 2). Uveal (ocular) melanoma represents an ideal cancer for applying this strategy. Uveal melanoma is the most common primary cancer of the eye and has a strong predilection for hematogenous metastasis, particularly to the liver (3). Investigators have searched for clinical and pathologic prognostic factors for over a century and have identified several that are statistically associated with metastasis, including advanced patient age, anterior tumor location, increased tumor size, epithelioid cell type, and local tumor invasion through the sclera. However, predictive accuracy of these factors has not been adequate for making individualized clinical decisions, such as whether a given patient is at sufficiently high risk for metastasis to necessitate more intense and frequent metastatic surveillance or whether prophylactic systemic therapy may be appropriate. More recently, investigators have identified genetic alterations, such as monosomy 3, which are significantly associated with metastasis (4 -6). With the development of more precise techniques for detecting chromosomal alterations, such as spectral karyoty...
Purpose: Loss of chromosome 3 is strongly associated with metastasis in uveal melanoma and has been proposed as the basis for clinical prognostic testing. It is not known whether techniques that identify loss of heterozygosity for chromosome 3 predict metastasis more accurately than those that detect only numerical loss of chromosome 3 (monosomy 3). Experimental Design: Fifty-three uveal melanomas were analyzed by 28 single nucleotide polymorphisms (SNP) across chromosome 3. SNP was compared with fluorescence in situ hybridization (FISH) and array-based comparative genomic hybridization (aCGH) for metastasis prediction by sensitivity, specificity, and Kaplan-Meier survival analysis, using our validated gene expression-based classifier as a reference standard. Results: By Kaplan-Meier analysis, only the gene expression-based classifier (P = 0.001) and SNP-based detection of loss of heterozygosity for chromosome 3 (P = 0.04) were significantly associated with metastasis. Sensitivity and specificity were 95.2% and 80.8%, respectively, for SNP, 77.8% and 64.7%, respectively, for FISH, and 85.0% and 72.0%, respectively, for aCGH. Isodisomy 3 was identified by SNP but undetected by aCGH and FISH in three tumors. Conclusions: Prognostic tests based on SNP platforms, which detect both chromosomal homologues and their subregions, may be superior to techniques that only detect changes in chromosome number. These observations could have important implications for efforts to detect genetic alterations in cancer genomes with CGH-based approaches.Uveal melanoma is the most common primary cancer of the eye and has a strong predilection for hematogenous metastasis, particularly to the liver (1). Up to half of uveal melanoma patients develop metastasis with a median time of 2.4 years from ocular diagnosis, usually leading to death within a few months (2). This has lead some investigators to propose that high-risk patients should be treated with prophylactic systemic therapy (3). However, an accurate prognostic classifier for identifying high-risk patients who may benefit from prophylactic therapy has not been validated.Many clinical and pathologic features have been associated with metastatic disease, but none of these has been shown to have adequate sensitivity and specificity for making personalized clinical decisions. Monosomy 3, detected by cytogenetic analysis, spectral karyotyping, fluorescence in situ hybridization (FISH), comparative genomic hybridization (CGH), and other techniques, may be more accurate than clinical and pathologic features and has been adopted as a molecular prognostic marker in many centers (4 -12). More recently, two distinct molecular subgroups were identified by gene expression profiling that correlate strongly with metastatic risk (13,14). Tumors with the class 1 expression signature had a low risk, and those with the class 2 signature had a high risk of metastasis. Although there was a strong association between the class 2 signature and monosomy 3, the gene expression-based classifier w...
Uveal melanoma (UM) is the most common primary intraocular malignancy in adults. While effective therapy exists for the primary tumor, there is a lack of effective treatment for metastatic disease currently. Natural withanolide withaferin A (WA) has shown efficacy in cancers demonstrating upregulation of pro-survival pathways. The purpose of the present study is to investigate the effect of WA as a potential therapeutic agent for UM in vitro as well as in vivo. UM cells were treated with WA and several cell-based assays, such as MTS, trypan blue exclusion assay, clonogenic, wound healing, cell cycle shift, annexin V/propidium iodide, and Western blot, were performed. In vivo experiments utilized the 92.1 cells in a xenograft murine model. WA inhibits cell proliferation of uveal melanoma cells with an IC50 of 0.90, 1.66, and 2.42 μM for OMM2.3, 92.1, and MEL290 cells, respectively. Flow cytometry analysis demonstrates G2/M cell cycle arrest and apoptosis at 1 μM WA in treated cells. WA induced apoptosis partly through the suppression of c-Met, Akt, and Raf-1 signaling activation. In vivo studies using WA reduced tumor growth in 100% of animals (p = 0.015). Our observation indicates that WA is a potent drug that inhibits cell proliferation, shifts cell cycle arrest, and induces apoptosis in multiple UM cell lines in vitro. WA-mediated apoptosis in UM cells is partly mediated though the suppression of c-Met and Akt activation. WA significantly decreases UM tumor growth in vivo and justifies further evaluation of this drug for the treatment of metastatic uveal melanoma.
The inhibitor of DNA binding 2 (Id2) basic helix-loop-helix protein interacts genetically and physically with the pocket proteins (Rb, p107 and p130) and has been implicated as an oncogene. In other studies, however, Id2 has been shown to function as a tumor suppressor. Here, we studied the role of Id2 in a well characterized model of ocular cancer in which the three pocket proteins are inactivated by generating mice lacking one or both Id2 alleles. Id2 deficiency had no impact on tumorigenesis in the eye. Unexpectedly, however, Id2 loss significantly increased the rate of metastasis. Liver metastases in Id2 heterozygotes demonstrated significant decrease of Id2 expression and loss of the remaining Id2 allele, strongly suggesting that Id2 inactivation specifically was required for metastasis in this model. These findings provide new insights into the role of Id2 in metastasis.
<div>Abstract<p><b>Purpose:</b> Loss of chromosome 3 is strongly associated with metastasis in uveal melanoma and has been proposed as the basis for clinical prognostic testing. It is not known whether techniques that identify loss of heterozygosity for chromosome 3 predict metastasis more accurately than those that detect only numerical loss of chromosome 3 (monosomy 3).</p><p><b>Experimental Design:</b> Fifty-three uveal melanomas were analyzed by 28 single nucleotide polymorphisms (SNP) across chromosome 3. SNP was compared with fluorescence <i>in situ</i> hybridization (FISH) and array-based comparative genomic hybridization (aCGH) for metastasis prediction by sensitivity, specificity, and Kaplan-Meier survival analysis, using our validated gene expression-based classifier as a reference standard.</p><p><b>Results:</b> By Kaplan-Meier analysis, only the gene expression-based classifier (<i>P</i> = 0.001) and SNP-based detection of loss of heterozygosity for chromosome 3 (<i>P</i> = 0.04) were significantly associated with metastasis. Sensitivity and specificity were 95.2% and 80.8%, respectively, for SNP, 77.8% and 64.7%, respectively, for FISH, and 85.0% and 72.0%, respectively, for aCGH. Isodisomy 3 was identified by SNP but undetected by aCGH and FISH in three tumors.</p><p><b>Conclusions:</b> Prognostic tests based on SNP platforms, which detect both chromosomal homologues and their subregions, may be superior to techniques that only detect changes in chromosome number. These observations could have important implications for efforts to detect genetic alterations in cancer genomes with CGH-based approaches.</p></div>
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