The Role of RASSF1A in Uveal Melanoma

1, 5, 6 PURPOSE. RASSF1A inactivation in uveal melanoma (UM) is common and methylation-induced. We investigated the effect of RASSF1A re-expression on the UM phenotype in vivo and in vitro. METHODS. The phenotypic effect of methylation-induced inactivation of RASSF1A in UM was explored using a stable RASSF1A-expressing UM-15 clone. RASSF1A expression was assessed using QRT-PCR. Proliferation was evaluated in vitro using MTT assays. Additionally, athymic NOD/SCID mice were injected subcutaneously or intraocularly with RASSF1A-expressing and -non-expressing UM-15 clones, and euthanized when tumors reached a volume of 1500 mm 3 , or at 56 or 46 days, respectively. Tumor tissues, eyes, and livers were analyzed histologically. RESULTS. In vitro analysis confirmed the lack of RASSF1A expression and full methylation of the RASSF1A promoter region in the UM-15 cell line, which was reversible following treatment with 5-Aza-2-deoxycytidine. Cells expressing exogenous RASSF1A showed slower proliferation than controls and regained sensitivity to cisplatin. Compared to mice injected with control cells, mice treated with UM-15 cells expressing exogenous RASSF1A did not acquire intraocular tumors, and their subcutaneous tumors were relatively delayed and small. Neither group had liver metastases. CONCLUSIONS. UM cells reduced tumorigenicity in the presence of activated RASSF1A. RASSF1A apparently has an important role in the development of UM, and its reactivation might be applied in the development of new treatments. (Invest Ophthalmol Vis Sci. 2012;53:2611-2619) DOI:10.1167/ iovs.11-7730 U veal melanoma (UM) is the most common form of primary eye cancer in adults, with an annual incidence of 6-7 cases per million per year. 1 It accounts for 80% of all noncutaneous melanomas and 13% of all deaths caused by melanoma. The tumor carries up to 50% 5-year mortality from metastasis. 3,4 However, their biological and clinical behaviors differ. 2 Additionally, although alterations of chromosomes 1 and 6 are common to both tumors, aberrations, such as monosomy of chromosome 3 and gain of 8q, in addition to other aberrations, typically are found only in UM. 9 Studies revealed that a mutation in the alpha subunit of the heterotrimeric G gene (GNAQ) was present in almost half of all UMs examined, 9-15 and that UM metastatic spread was related to mutations in the BRCA associated protein 1 (BAP1) gene on chromosome 3. 9 Aberrant promoter hypermethylation of CpG islands is thought to have an important role in the inactivation of tumor suppressor genes (TSGs) in cancer. 21 From th

Elevated levels of FMR1 mRNA in granulosa cells are associated with low ovarian reserve in FMR1 premutation carriers.

AimTo assess the role of mRNA accumulation in granulosa cells as the cause of low ovarian response among FMR1 premutation carriers undergoing pre-implantation genetic diagnosis (PGD).DesignCase control study in an academic IVF unit. Twenty-one consecutive FMR1 premutation carriers and 15 control women were included. After oocyte retrieval the granulosa cells mRNA levels of FMR1 was measured using RT-PCR.ResultsIn FMR1 premutation carriers, there was a significant non-linear association between the number of CGG repeats and the number of retrieved oocytes (pConclusionWe suggest that there is a no-linear association between the number of CGG repeats and ovarian function, resulting from an increased granulosa cells FMR1 mRNA accumulation in FMR1 carriers in the mid-range (80-120 repeats)

FMRpolyG accumulates in FMR1 premutation granulosa cells

Abstract Background Fragile X premutation (Amplification of CGG number 55–200) is associated with increased risk for fragile X-Associated Premature Ovarian Insufficiency (FXPOI) in females and fragile X-associated tremor/ataxia syndrome (FXTAS) predominantly in males. Recently, it has been shown that CGG repeats trigger repeat associated non-AUG initiated translation (RAN) of a cryptic polyglycine-containing protein, FMRpolyG. This protein accumulates in ubiquitin-positive inclusions in neuronal brain cells of FXTAS patients and may lead to protein-mediated neurodegeneration. FMRpolyG inclusions were also found in ovary stromal cells of a FXPOI patient. The role of FMRpolyG expression has not been thoroughly examined in folliculogenesis related cells. The main goal of this study is to evaluate whether FMRpolyG accumulates in mural granulosa cells of FMR1 premutation carriers. Following FMRpolyG detection, we aim to examine premutation transfected COV434 as a suitable model used to identify RAN translation functions in FXPOI pathogenesis. Results FMRpolyG and ubiquitin immunostained mural granulosa cells from six FMR1 premutation carriers demonstrated FMRpolyG aggregates. However, co-localization of FMRpolyG and ubiquitin appeared to vary within the FMR1 premutation carriers’ group as three exhibited partial ubiquitin and FMRpolyG double staining and three premutation carriers demonstrated FMRpolyG single staining. None of the granulosa cells from the five control women expressed FMRpolyG. Additionally, human ovarian granulosa tumor, COV434, were transfected with two plasmids; both expressing 99CGG repeats but only one enables FMRpolyG expression. Like in granulosa cells from FMR1 premutation carriers, FMRpolyG aggregates were found only in COV434 transfected with expended CGG repeats and the ability to express FMRpolyG. Conclusions Corresponding with previous studies in FXTAS, we demonstrated accumulation of FMRpolyG in mural granulosa cells of FMR1 premutation carriers. We also suggest that following further investigation, the premutation transfected COV434 might be an appropriate model for RAN translation studies. Detecting FMRpolyG accumulation in folliculogenesis related cells supports previous observations and imply a possible common protein-mediated toxic mechanism for both FXPOI and FXTAS

A trend for a non-linear association between FMR1 mRNA levels in granulosa cells of FMR1 premutation carriers (55–200 repeats) and the number of CGG repeats.

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