Orchestrating epigenetic roles targeting ocular tumors

An Artificial CTCF Peptide Triggers Efficient Therapeutic Efficacy in Ocular Melanoma

Although CCCTC binding factor (CTCF) has been demonstrated to play a variety of often contradictory roles in tumorigenesis, little is known about its function in the tumorigenesis of ocular melanoma. Here, we generated two artificial CTCF peptides (Decoy-CTCFs) combining the zinc finger domain of wild-type CTCF and artificial marker region. This Decoy-CTCF retained the DNA binding region but lost the functional regions of wild-type CTCF. Transferring artificial CTCF into ocular melanoma cells suppressed proliferation and migration in the tumor cells, while no effect was observed in normal cells. Intriguingly, we first showed that decoy-CTCF inhibited tumorigenesis by preventing the histone acetyltransferase EP300 from binding to the promoter of SELL. Thus SELL was a novel oncogene in the tumorigenesis of ocular melanoma. These studies provide efficient decoy CTCF-based therapeutic concept in malignant ocular melanoma and reveal the potential mechanism underlying decoy-based tumor therapy.

Uveal melanoma: epidemiology, etiology, and treatment of primary disease

Uveal melanoma (UM) is the most common intraocular malignancy and arises from melanocytes in the iris, ciliary body, or choroid. Early diagnosis and local treatment is crucial, as survival correlates with primary tumor size. However, approximately 50% of patients will develop metastatic disease with 6-12 months' survival from metastatic diagnosis. Genomic analyses have led to the development of gene-expression profiles that effectively predict metastatic progression; unfortunately, no adjuvant therapy has been shown to prolong survival to date. New insights into the molecular biology of UM have found frequent activating mutations in genes encoding for the G-protein α-subunit, GNAQ and GNA11, and improved understanding of the downstream signaling pathways MAPK, PI3K/Akt, and Hippo have afforded an array of new targets for treatment of this disease. Studies are under way with rationally developed regimens targeting these pathways, and novel agents are under development. We review the diagnosis, management, and surveillance of primary UM and the adjuvant therapy trials under way.

Ocular melanoma-when you have seen one, you have not seen them all: a clinical outcome study from the Surveillance, Epidemiology and End Results (SEER) database (1973-2012)

BACKGROUND

Ocular melanoma (OM) comprises <5% of all melanomas. Uveal melanoma (UM) is the most common subtype of OM, while conjunctival melanoma (CM) is rare and differs significantly from UM. The purpose of this study is to evaluate a large cohort of OM patients to differentiate demographic, pathologic, and clinical factors between these two neoplasms, which may affect treatment and outcomes.

METHODS

The Surveillance, Epidemiology, and End Results database (1973-2012) was used to extract demographic and clinical data on 8,165 OM patients (92.1% UM and 7.9% CM).

RESULTS

Both CM and UM were most prevalent among Caucasian males in the seventh decade of life. UM patients presented more often with localized disease (90.9% vs 81.2, P<0.01). Surgery (42.8%), radiation (43.0%), or combined surgery and radiation (7.0%) were used in the treatment of UM, while CM was treated almost exclusively with surgery (88.7%). Mean overall survival was longer (15.4 vs 14.6 years; P<0.01) and mortality rates were lower in patients (38.8% vs 46.1%; P<0.01) with CM.

CONCLUSION

Despite presenting with more advanced disease than UM, CM is associated with an increased overall survival. Surgery is the primary therapy for CM, whereas radiotherapy is the primary therapy for UM and is associated with prolonged survival.