33 research outputs found
Expression of HDACs 1, 3 and 8 Is upregulated in the presence of Infiltrating lymphocytes in uveal melanoma
Simple Summary Uveal melanoma (UM) is an ocular malignancy which is derived from melanocytes in the uveal tract. Epigenetic regulators such as Histone Deacetylase (HDACs) inhibitors are being tested as treatment of UM metastases. Expression of different HDACs is variable, and some are increased in high-risk tumors with loss of one chromosome 3. As this genetic abnormality is also associated with an inflammatory phenotype, we analyzed whether HDAC expression was influenced by inflammation. In two cohorts of UM cases, expression of several HDACs showed a positive correlation with tumor-infiltrating T cells, while HDACs 2 and 11 showed a negative association with macrophages. Interferon-gamma stimulated expression of some HDACs on UM cell lines. These data suggest that cytokines produced by T cells may be responsible for the increased expression of some HDACs in UM with monosomy 3. In Uveal Melanoma (UM), an inflammatory phenotype is strongly associated with the development of metastases and with chromosome 3/BAP1 expression loss. As an increased expression of several Histone Deacetylases (HDACs) was associated with loss of chromosome 3, this suggested that HDAC expression might also be related to inflammation. We analyzed HDAC expression and the presence of leukocytes by mRNA expression in two sets of UM (Leiden and TCGA) and determined the T lymphocyte fraction through ddPCR. Four UM cell lines were treated with IFN gamma (50IU, 200IU). Quantitative PCR (qPCR) was used for mRNA measurement of HDACs in cultured cells. In both cohorts (Leiden and TCGA), a positive correlation occurred between expression of HDACs 1, 3 and 8 and the presence of a T-cell infiltrate, while expression of HDACs 2 and 11 was negatively correlated with the presence of tumor-infiltrating macrophages. Stimulation of UM cell lines with IFN gamma induced an increase in HDACs 1, 4, 5, 7 and 8 in two out of four UM cell lines. We conclude that the observed positive correlations between HDAC expression and chromosome 3/BAP1 loss may be related to the presence of infiltrating T cells.Cancer Signaling networks and Molecular Therapeutic
MiRNAs correlate with HLA expression in uveal melanoma: both up- and downregulation are related to monosomy 3
Simple Summary Uveal melanoma (UM) is a rare ocular malignancy that often gives rise to metastases. Tumours with an inflammatory phenotype have an especially bad prognosis. As an increased HLA expression and the presence of tumour-infiltrating lymphocytes and macrophages may be regulated by miRNAs, we set out to investigate whether any miRNAs are associated with inflammatory parameters in this malignancy. Some miRNAs were increased in UM with a high HLA expression and high T cell numbers, while others were decreased, showing two opposing patterns; however, both patterns were related to the tumour's chromosome 3/BAP1 status. We conclude that specific miRNAs are related to the inflammatory phenotype and that these are differentially expressed between disomy 3/BAP1-positive versus monosomy 3/BAP1-negative UM. MicroRNAs are known to play a role in the regulation of inflammation. As a high HLA Class I expression is associated with a bad prognosis in UM, we set out to determine whether any miRNAs were related to a high HLA Class I expression and inflammation. We also determined whether such miRNAs were related to the UM's genetic status. The expression of 125 miRNAs was determined in 64 primary UM from Leiden. Similarly, the mRNA expression of HLA-A, HLA-B, TAP1, BAP1, and immune cell markers was obtained. Expression levels of 24 of the 125 miRNAs correlated with expression of at least three out of four HLA Class I probes. Four miRNAs showed a positive correlation with HLA expression and infiltration with leukocytes, 20 a negative pattern. In the first group, high miRNA levels correlated with chromosome 3 loss/reduced BAP1 mRNA expression, in the second group low miRNA levels. The positive associations between miRNA-22 and miRNA-155 with HLA Class I were confirmed in the TCGA study and Rotterdam cohort, and with TAP1 in the Rotterdam data set; the negative associations between miRNA-125b2 and miRNA-211 and HLA-A, TAP1, and CD4 were confirmed in the Rotterdam set. We demonstrate two patterns: miRNAs can either be related to a high or a low HLA Class I/TAP1 expression and the presence of infiltrating lymphocytes and macrophages. However, both patterns were associated with chromosome 3/BAP1 status, which suggests a role for BAP1 loss in the regulation of HLA expression and inflammation in UM through miRNAs.Development and application of statistical models for medical scientific researc
Tumour Angiogenesis in Uveal Melanoma Is Related to Genetic Evolution
Increased angiogenesis is associated with a higher metastasis- and mortality rate in uveal
melanoma (UM). Recently, it was demonstrated that genetic events, such as 8q-gain and BAP1-loss,
influence the level of immune infiltrate. We aimed to determine whether genetic events, and specific
cytokines, relate to angiogenesis in UM. Data from UM patients who underwent enucleation between
1999 and 2008 were analysed. Microvascular density (MVD) and the presence of infiltrating immune
cells were determined with immunohistochemistry (IHC) and immunofluorescence in 43 cases.
Chromosome status, BAP1 IHC and mRNA expression of angiogenesis-related genes were known
in 54 cases. Tumours with monosomy 3/BAP1-loss showed a higher MVD compared to tumours
with disomy 3/normal BAP1 expression (p = 0.008 and p = 0.004, respectively). Within BAP1-positive
lesions (n = 20), 8q-gain did not relate to MVD (p = 0.51). A high MVD was associated with an
increased expression of angiopoietin 2 (ANGPT2) (p = 0.041), Von Willebrand Factor (VWF) (p = 0.010),
a decreased expression of vascular endothelial growth factor B (VEGF-B) (p = 0.024), and increased
numbers of tumour-infiltrating macrophages (CD68+, p = 0.017; CD68+CD163+, p = 0.031) and
lymphocytes (CD4+, p = 0.027). Concluding, vascular density of UM relates to its genetic profile:
Monosomy 3 and BAP1-loss are associated with an increased MVD, while an early event (gain of 8q)
is not independently related to MVD, but may initiate a preparation phase towards development of
vessels. Interestingly, VEGF-B expression is decreased in UM with a high MVD
Ab initio atomistic thermodynamics and statistical mechanics of surface properties and functions
Previous and present "academic" research aiming at atomic scale understanding
is mainly concerned with the study of individual molecular processes possibly
underlying materials science applications. Appealing properties of an
individual process are then frequently discussed in terms of their direct
importance for the envisioned material function, or reciprocally, the function
of materials is somehow believed to be understandable by essentially one
prominent elementary process only. What is often overlooked in this approach is
that in macroscopic systems of technological relevance typically a large number
of distinct atomic scale processes take place. Which of them are decisive for
observable system properties and functions is then not only determined by the
detailed individual properties of each process alone, but in many, if not most
cases also the interplay of all processes, i.e. how they act together, plays a
crucial role. For a "predictive materials science modeling with microscopic
understanding", a description that treats the statistical interplay of a large
number of microscopically well-described elementary processes must therefore be
applied. Modern electronic structure theory methods such as DFT have become a
standard tool for the accurate description of individual molecular processes.
Here, we discuss the present status of emerging methodologies which attempt to
achieve a (hopefully seamless) match of DFT with concepts from statistical
mechanics or thermodynamics, in order to also address the interplay of the
various molecular processes. The new quality of, and the novel insights that
can be gained by, such techniques is illustrated by how they allow the
description of crystal surfaces in contact with realistic gas-phase
environments.Comment: 24 pages including 17 figures, related publications can be found at
http://www.fhi-berlin.mpg.de/th/paper.htm
HDAC inhibition increases HLA class I expression in uveal melanoma
The treatment of uveal melanoma (UM) metastases or adjuvant treatment may imply immunological approaches or chemotherapy. It is to date unknown how epigenetic modifiers affect the expression of immunologically relevant targets, such as the HLA Class I antigens, in UM. We investigated the expression of HDACs and the histone methyl transferase EZH2 in a set of 64 UMs, using an Illumina HT12V4 array, and determined whether a histone deacetylase (HDAC) inhibitor and EZH2 inhibitor modified the expression of HLA Class I on three UM cell lines. Several HDACs (HDAC1, HDAC3, HDAC4, and HDAC8) showed an increased expression in high-risk UM, and were correlated with an increased HLA expression. HDAC11 had the opposite expression pattern. While in vitro tests showed that Tazemetostat did not influence cell growth, Quisinostat decreased cell sur
Aqueous Humor Biomarkers Identify Three Prognostic Groups in Uveal Melanoma
Purpose: To investigate whether we can identify different patterns of inflammation in the aqueous humor of a uveal melanoma (UM)-containing eye, and whether these are related to prognosis. Meth
Extended Tersoff potential for boron nitride: Energetics and elastic properties of pristine and defective h-BN
Contains fulltext :
180544.pdf (Publisher’s version ) (Open Access
ExTeP potential for B-N developed by Los et al. (2017) v000
This is an extended Tersoff potential for boron nitride (BN-ExTeP) for application in large scale atomistic simulations. It accurately describes the main low energy B, N, and BN structures and yields quantitatively correct trends in the bonding as a function of coordination. The proposed extension of the bond order, added to improve the dependence of bonding on the chemical environment, leads to an accurate description of point defects in hexagonal BN (h-BN) and cubic BN (c-BN)
Ischemia Is Related to Tumour Genetics in Uveal Melanoma
Hereditary cancer genetic
Lag3 and its ligands show increased expression in high-risk uveal melanoma
Uveal melanoma (UM) is a rare ocular malignancy which originates in the uveal tract, and often gives rise to metastases. Potential targets for immune checkpoint inhibition a