A Subset of Nuclear Receptors are Uniquely Expressed in Uveal Melanoma Cells

[The effect of sex hormones and pregnancy on development and progression of uveal melanoma]

The analysis of literature revealed that men experience uveal melanoma (UM) more frequently and with worse prognosis. There are also descriptions of an aggressive course of UM in pregnant women. These facts prompted researchers to analyze the effect of sex hormones and pregnancy on the development and progression of UM. Many years of international experience have refuted the presence of a reliable difference between 5-year survival and 5-year survival without metastases between non-pregnant women with UM and pregnant women with UM. That data is regarded as level 3 evidence. The experts have concluded that UM is not a contraindication to current or future pregnancy, and exogenous hormones (oral contraceptives or hormone replacement therapy) do not affect the incidence and prognosis of UM. Publications provide evidence of expression of the receptors of certain sex hormones (ER, ERRα, LH and LHRH) in primary UM, as well as overexpression of the ESR1 and ESR2 genes in UM with poor predictive characteristics. Overall AR mRNA expression in UM was low, but it was higher in epithelial UMs. The fact of expression of estrogen receptors in UM gives grounds to experiment with them as a target for therapy.

Estrogen Receptor Is Expressed in Uveal Melanoma: A Potential Target for Therapy

Background

Metastatic uveal melanoma (UM) has no effective treatment. To date, no publications have reported immunohistochemical evidence of estrogen receptors (ERs) in UM; however, changes in pathologic reporting for ER in breast carcinoma prompted a re-examination of ER in UM, as it could represent a potential therapeutic target.

Objective

To determine if UM tumors express ER by immunohistochemistry (IHC) using current methodology for breast cancer and to evaluate ER gene expression using a publicly available UM database.

Methods

A retrospective IHC analysis with clinical correlation was performed on 2 cohorts: 57 cases from the Cleveland Clinic (CC) and 50 from the Ohio State University Wexner Medical Center (OSUWMC). Analysis of The Cancer Genome Atlas Project (TCGA) UM Dataset of 80 patients was also performed.

Results

Presence of ER was detected by IHC in 20 of 34 (59%) analyzable cases in the CC cohort. Of the 50 patients in the OSU cohort, 52 specimens from 47 patients were sufficient for analysis. Of these 47 cases, 29 (62%) had tumor that was ER positive in ≥1% nuclei. In the second cohort, positivity was classified as positive (≥10% nuclei, 34% cases) or low positive (1-9% nuclei, 28% cases). In 5 patients, there were paired samples, that is, primary tumor and subsequent recurrence or metastasis, with concordance for ER in 4 of 5 cases. In the TCGA database, elevated ESR1 and ESR2 gene expression was identified in a subset of UM tumors with poor genetic prognostic features.

Conclusions and Relevance

Potentially actionable ER expression is present in greater than half of UM cases by IHC. Gene expression of ESR1 and ESR2 was elevated in a subset of UM tumors with poor prognostic features. These data provide a rationale to evaluate ER as a potential target for therapy in UM.

Is Uveal Melanoma a Hormonally Sensitive Cancer? A Review of the Impact of Sex Hormones and Pregnancy on Uveal Melanoma

BACKGROUND

Despite a higher incidence and worse prognosis of uveal melanoma (UM) in men, there have been many case reports of pregnant patients with aggressive UM. This has led researchers to explore the influence of sex hormones and pregnancy on the development and progression of UM and hormones as potential therapeutic targets.

SUMMARY

A systematic literature review was conducted. More work is needed to elucidate the basis of sex differences in UM incidence and survival. The evaluation of germline BAP1 mutation would be beneficial in patients with UM presenting at a young age. Importantly, multiple studies reported no significant difference between the 5-year survival and 5-year metastasis-free survival rates between nonpregnant women with UM and pregnant women with UM. Multiple case-control studies disagree on how parity affects risk of UM. However, most studies agree that oral contraceptives and hormone replacement therapy have no effect on the incidence of UM. Current treatment strategies for pregnant patients with UM are discussed. Looking forward, this review reports recent research on targeted receptor-based chemotherapy, which is based on evidence of estrogen receptor (ER), estrogen-related receptor alpha (ERRα), and luteinizing hormone-releasing hormone (LHRH) receptor expression in UM.

KEY MESSAGES

Based on review of the literature, UM is not a contraindication to oral contraceptives, hormone replacement therapy, or pregnancy. Globe-sparing radiation can be used as a treatment option for pregnant patients. Due to the presence of ER on a subset of unselected UM, its potential for adjunctive targeted therapy with agents like tamoxifen should be explored. Lessons from cutaneous melanoma regarding tissue ratios of estrogen receptors (ERα:ERβ) should be applied to assess their therapeutic predictive value. In addition, ERRα-targeted therapeutics and LHRH analogs are worthy of further exploration in UM.

Genetic and epigenetic insights into uveal melanoma

Uveal melanoma (UM) is the most frequent primary intraocular tumor in Caucasian adults and is potentially fatal if metastases develop. While several prognostic genetic changes have been identified in UM, epigenetic influences are now getting closer attention. Recent technological advances have allowed to exam the human genome to a greater extent and have improved our understanding of several diseases including malignant tumors. In this context, there has been tremendous progress in the field of UM pathogenesis. Herein, we review the literature with emphasis on genetic alterations, epigenetic modifications and signaling pathways as well as possible biomarkers in UM. In addition, different research models for UM are discussed. New insights and major challenges are outlined in order to evaluate the current status for this potentially devastating disease.

Dendrogenin A drives LXR to trigger lethal autophagy in cancers

Dendrogenin A (DDA) is a newly discovered cholesterol metabolite with tumor suppressor properties. Here, we explored its efficacy and mechanism of cell death in melanoma and acute myeloid leukemia (AML). We found that DDA induced lethal autophagy in vitro and in vivo, including primary AML patient samples, independently of melanoma Braf status or AML molecular and cytogenetic classifications. DDA is a partial agonist on liver-X-receptor (LXR) increasing Nur77, Nor1, and LC3 expression leading to autolysosome formation. Moreover, DDA inhibited the cholesterol biosynthesizing enzyme 3β-hydroxysterol-Δ^8,7-isomerase (D8D7I) leading to sterol accumulation and cooperating in autophagy induction. This mechanism of death was not observed with other LXR ligands or D8D7I inhibitors establishing DDA selectivity. The potent anti-tumor activity of DDA, its original mechanism of action and its low toxicity support its clinical evaluation. More generally, this study reveals that DDA can direct control a nuclear receptor to trigger lethal autophagy in cancers.