scholarly journals Ischemia Is Related to Tumour Genetics in Uveal Melanoma

Cancers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1004 ◽  
Author(s):  
Niels J. Brouwer ◽  
Annemijn P. A. Wierenga ◽  
Gülçin Gezgin ◽  
Marina Marinkovic ◽  
Gregorius P. M. Luyten ◽  
...  
Keyword(s):  
Uveal Melanoma ◽  
Messenger Rna ◽  
Tumour Size ◽  
Hypoxia Inducible Factor ◽  
The Cancer Genome Atlas ◽  
Basal Diameter ◽  
Von Hippel Lindau ◽  
The Status ◽  
Using Data ◽  
Tumour Genetics

Hypoxia-inducible factor 1-alpha (HIF1a) and its regulator von Hippel–Lindau protein (VHL) play an important role in tumour ischemia. Currently, drugs that target HIF1a are being developed to treat malignancies. Although HIF1a is known to be expressed in uveal melanoma (UM), it is as yet unknown which factors, such as tumour size or genetics, determine its expression. Therefore, we aimed to determine which tumour characteristics relate to HIF1a expression in UM. Data from 64 patients who were enucleated for UM were analysed. Messenger RNA (mRNA) expression was determined with the Illumina HT-12 v4 chip. In 54 cases, the status of chromosomes 3 and 8q, and BRCA1-associated protein 1 (BAP1) protein expression (immunohistochemistry) were determined. Findings were corroborated using data of 80 patients from the Cancer Genome Atlas (TCGA) study. A significantly increased expression of HIF1a, and a decreased expression of VHL were associated with monosomy 3/loss of BAP1 expression. The relationship between BAP1 loss and HIF1a expression was independent of chromosome 3. The largest basal diameter and tumour thickness showed no relationship with HIF1a. HIF1a expression related to an increased presence of infiltrating T cells and macrophages. From this study, we conclude that HIF1a is strongly related to tumour genetics in UM, especially to loss of BAP1 expression, and less to tumour size. Tumour ischemia is furthermore related to the presence of an inflammatory phenotype.

scholarly journals Increased Non-Homologous End Joining Makes DNA-PK a Promising Target for Therapeutic Intervention in Uveal Melanoma

Cancers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1278 ◽  
Author(s):  
Doherty ◽  
Bryant ◽  
Valluru ◽  
Rennie ◽  
Sisley
Keyword(s):  
Uveal Melanoma ◽  
Messenger Rna ◽  
Therapeutic Option ◽  
Survival Rates ◽  
The Cancer Genome Atlas ◽  
End Joining ◽  
Expression Of Genes ◽  
Effective Therapeutic Option ◽  
Non Homologous End Joining ◽  
Induced Apoptosis

Uveal melanoma (UM) is the most common primary intraocular tumour in adults, with a mean survival of six months following metastasis. The survival rates have not improved in over 30 years. This study has shown that sister chromatid exchange (SCE) is low in UM which is likely due to a reduced expression of FANCD2. As FANCD2 can function to suppress non-homologous end joining (NHEJ), this study therefore investigated NHEJ in UM. The activation of the catalytic subunit of the NHEJ pathway protein DNA-dependent protein kinase (DNA-PK) was measured by analysing the foci formation and the ligation efficiency by NHEJ determined using a plasmid-based end-joining assay. Using small-interfering RNA (siRNA) knock-down, and chemical inhibitors of DNA-PK, the survival of primary UM cultures and two cell lines were determined. To assess the homologous recombination capacity in response to the inhibition of DNA-PK, a SCE analysis was performed. In addition, to support the findings, the messenger RNA (mRNA) expression of genes associated with NHEJ was analysed using the Cancer Genome Atlas (TCGA)-UM RNAseq data (n = 79). The NHEJ activity and DNA-PKcs activation was upregulated in UM and the inhibition of DNA-PK selectively induced apoptosis and sensitized to ionising radiation and inter-strand cross-linking agents. The inhibition of the NHEJ protein DNA-PK is lethal to UM, indicating a potentially effective therapeutic option, either alone or as a sensitizer for other treatments.

scholarly journals Monosomy 3 Is Linked to Resistance to MEK Inhibitors in Uveal Melanoma

2021 ◽  
Vol 22 (13) ◽  
pp. 6727
Author(s):  
Svenja Mergener ◽  
Jens T. Siveke ◽  
Samuel Peña-Llopis
Keyword(s):  
Cell Lines ◽  
Uveal Melanoma ◽  
Survival Data ◽  
Translation Initiation Factor ◽  
The Cancer Genome Atlas ◽  
Initiation Factor ◽  
Chromosome 3 ◽  
Mek Inhibitors ◽  
Mek Inhibition ◽  
Insight Into

The use of MEK inhibitors in the therapy of uveal melanoma (UM) has been investigated widely but has failed to show benefits in clinical trials due to fast acquisition of resistance. In this study, we investigated a variety of therapeutic compounds in primary-derived uveal melanoma cell lines and found monosomy of chromosome 3 (M3) and mutations in BAP1 to be associated with higher resistance to MEK inhibition. However, reconstitution of BAP1 in a BAP1-deficient UM cell line was unable to restore sensitivity to MEK inhibition. We then compared UM tumors from The Cancer Genome Atlas (TCGA) with mutations in BAP1 with tumors with wild-type BAP1. Principal component analysis (PCA) clearly differentiated both groups of tumors, which displayed disparate overall and progression-free survival data. Further analysis provided insight into differential expression of genes involved in signaling pathways, suggesting that the downregulation of the eukaryotic translation initiation factor 2A (EIF2A) observed in UM tumors with BAP1 mutations and M3 UM cell lines might lead to a decrease in ribosome biogenesis while inducing an adaptive response to stress. Taken together, our study links loss of chromosome 3 with decreased sensitivity to MEK inhibition and gives insight into possible related mechanisms, whose understanding is fundamental to overcome resistance in this aggressive tumor.

scholarly journals A small molecule HIF-1α stabilizer that accelerates diabetic wound healing

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Guodong Li ◽  
Chung-Nga Ko ◽  
Dan Li ◽  
Chao Yang ◽  
Wanhe Wang ◽  
...  
Keyword(s):  
Wound Healing ◽  
Small Molecule ◽  
Hypoxia Inducible Factor ◽  
Diabetic Patients ◽  
Diabetic Mice ◽  
Impaired Wound Healing ◽  
Von Hippel Lindau ◽  
Design And Synthesis

AbstractImpaired wound healing and ulcer complications are a leading cause of death in diabetic patients. In this study, we report the design and synthesis of a cyclometalated iridium(III) metal complex 1a as a stabilizer of hypoxia-inducible factor-1α (HIF-1α). In vitro biophysical and cellular analyses demonstrate that this compound binds to Von Hippel-Lindau (VHL) and inhibits the VHL–HIF-1α interaction. Furthermore, the compound accumulates HIF-1α levels in cellulo and activates HIF-1α mediated gene expression, including VEGF, GLUT1, and EPO. In in vivo mouse models, the compound significantly accelerates wound closure in both normal and diabetic mice, with a greater effect being observed in the diabetic group. We also demonstrate that HIF-1α driven genes related to wound healing (i.e. HSP-90, VEGFR-1, SDF-1, SCF, and Tie-2) are increased in the wound tissue of 1a-treated diabetic mice (including, db/db, HFD/STZ and STZ models). Our study demonstrates a small molecule stabilizer of HIF-1α as a promising therapeutic agent for wound healing, and, more importantly, validates the feasibility of treating diabetic wounds by blocking the VHL and HIF-1α interaction.

scholarly journals Functions and clinical significance of KLRG1 in the development of lung adenocarcinoma and immunotherapy

BMC Cancer ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Xiaodong Yang ◽  
Yuexin Zheng ◽  
Zhihai Han ◽  
Xiliang Zhang
Keyword(s):  
Gene Expression ◽  
Overall Survival ◽  
Lung Adenocarcinoma ◽  
Molecular Mechanisms ◽  
Killer Cell ◽  
Gene Expression Omnibus ◽  
The Cancer Genome Atlas ◽  
Normal Lung ◽  
Using Data ◽  
Low Expression

Abstract Background As a marker of differentiation, Killer cell lectin like receptor G1 (KLRG1) plays an inhibitory role in human NK cells and T cells. However, its clinical role remains inexplicit. This work intended to investigate the predictive ability of KLRG1 on the efficacy of immune-checkpoint inhibitor in the treatment of lung adenocarcinoma (LUAD), as well as contribute to the possible molecular mechanisms of KLRG1 on LUAD development. Methods Using data from the Gene Expression Omnibus, the Cancer Genome Atlas and the Genotype-Tissue Expression, we compared the expression of KLRG1 and its related genes Bruton tyrosine kinase (BTK), C-C motif chemokine receptor 2 (CCR2), Scm polycomb group protein like 4 (SCML4) in LUAD and normal lung tissues. We also established stable LUAD cell lines with KLRG1 gene knockdown and investigated the effect of KLRG1 knockdown on tumor cell proliferation. We further studied the prognostic value of the four factors in terms of overall survival (OS) in LUAD. Using data from the Gene Expression Omnibus, we further investigated the expression of KLRG1 in the patients with different responses after immunotherapy. Results The expression of KLRG1, BTK, CCR2 and SCML4 was significantly downregulated in LUAD tissues compared to normal controls. Knockdown of KLRG1 promoted the proliferation of A549 and H1299 tumor cells. And low expression of these four factors was associated with unfavorable overall survival in patients with LUAD. Furthermore, low expression of KLRG1 also correlated with poor responses to immunotherapy in LUAD patients. Conclusion Based on these findings, we inferred that KLRG1 had significant correlation with immunotherapy response. Meanwhile, KLRG1, BTK, CCR2 and SCML4 might serve as valuable prognostic biomarkers in LUAD.

scholarly journals Quantification of BRAF V600E alleles predicts papillary thyroid cancer progression

2014 ◽  
Vol 21 (6) ◽  
pp. 891-902 ◽  
Author(s):  
Min-Hee Kim ◽  
Ja Seong Bae ◽  
Dong-Jun Lim ◽  
Hyoungnam Lee ◽  
So Ra Jeon ◽  
...  
Keyword(s):  
Thyroid Cancer ◽  
Cancer Progression ◽  
Tumour Size ◽  
External Validation ◽  
Allelic Frequency ◽  
The Cancer Genome Atlas ◽  
Braf V600e ◽  
Validation Dataset ◽  
Papillary Thyroid ◽  
Additional Information

The BRAF V600E mutation is the most common genetic alteration in thyroid cancer. However, its clinicopathological significance and clonal mutation frequency remain unclear. To clarify the inconsistent results, we investigated the association between the allelic frequency of BRAF V600E and the clinicopathological features of classic papillary thyroid carcinoma (PTC). Tumour tissues from two independent sets of patients with classic PTC were manually microdissected and analysed for the presence or absence of the BRAF mutation and the mutant allelic frequency using quantitative pyrosequencing. For external validation, the Cancer Genome Atlas (TCGA) data were analysed. The BRAF V600E mutation was found in 264 (82.2%) out of 321 classic PTCs in the training set. The presence of BRAF V600E was only associated with extrathyroidal extension and the absence of thyroiditis. In BRAF V600E-positive tumours, the mutant allelic frequency varied from 8 to 41% of the total BRAF alleles (median, 20%) and directly correlated with tumour size and the number of metastatic lymph nodes. Lymph node metastases were more frequent in PTCs with a high (≥20%) abundance of mutant alleles than in those with a low abundance of mutant alleles (P=0.010). These results were reinforced by validation dataset (n=348) analysis but were not reproduced in the TCGA dataset. In a population with prevalent BRAF mutations, quantitative analysis of the BRAF mutation could provide additional information regarding tumour behaviour, which is not reflected by qualitative analysis. Nonetheless, prospective studies are needed before the mutated allele percentage can be considered as a prognostic factor.

Pentecostalism as an Informal Political Institution: Experimental Evidence from Ghana

2014 ◽  
Vol 7 (4) ◽  
pp. 761-787 ◽  
Author(s):  
John F. McCauley
Keyword(s):  
Experimental Evidence ◽  
Dictator Game ◽  
Informal Institutions ◽  
Informal Institution ◽  
Resource Endowment ◽  
The Status ◽  
Micro Level ◽  
New Form ◽  
Using Data ◽  
Cultural Leaders

AbstractInformal institutions continue to govern political exchange in Africa, but the traditional, ethnic-based form of “big man rule” is now threatened by an alternative informal institution — charismatic Pentecostalism. This study evaluates the status of Pentecostalism empirically, in a micro-level experiment in Ghana. Using data from a variant of the dictator game, in which participants divide a resource endowment with randomly assigned partners as well as cultural leaders, the study provides evidence of Pentecostal exclusivity, excessive allegiance to leaders, and a shift away from ethnic-based patronage to Pentecostal patronage. As Pentecostalism continues to expand, these findings suggest a modification in the exchange of resources for loyalty in Africa, and grounds for viewing the movement as a new form of big man rule in the region.

scholarly journals Inactivation of the Arylhydrocarbon Receptor Nuclear Translocator (Arnt) Suppresses von Hippel-Lindau Disease-Associated Vascular Tumors in Mice

2005 ◽  
Vol 25 (8) ◽  
pp. 3163-3172 ◽  
Author(s):  
Erinn B. Rankin ◽  
Debra F. Higgins ◽  
Jacqueline A. Walisser ◽  
Randall S. Johnson ◽  
Christopher A. Bradfield ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Germ Line ◽  
Hypoxia Inducible Factor ◽  
Suppressor Gene ◽  
Vascular Tumors ◽  
Von Hippel Lindau ◽  
Von Hippel Lindau Disease ◽  
Arylhydrocarbon Receptor ◽  
Vhl Disease ◽  
Endothelial Growth Factor

ABSTRACT Patients with germ line mutations in the VHL tumor suppressor gene are predisposed to the development of highly vascularized tumors within multiple tissues. Loss of pVHL results in constitutive activation of the transcription factors HIF-1 and HIF-2, whose relative contributions to the pathogenesis of the VHL phenotype have yet to be defined. In order to examine the role of HIF in von Hippel-Lindau (VHL)-associated vascular tumorigenesis, we utilized Cre-loxP-mediated recombination to inactivate hypoxia-inducible factor-1α (Hif-1α) and arylhydrocarbon receptor nuclear translocator (Arnt) genes in a VHL mouse model of cavernous liver hemangiomas and polycythemia. Deletion of Hif-1α did not affect the development of vascular tumors and polycythemia, nor did it suppress the increased expression of vascular endothelial growth factor (Vegf) and erythropoietin (Epo). In contrast, phosphoglycerokinase (Pgk) expression was substantially decreased, providing evidence for target gene-dependent functional redundancy between different Hif transcription factors. Inactivation of Arnt completely suppressed the development of hemangiomas, polycythemia, and Hif-induced gene expression. Here, we demonstrate genetically that the development of VHL-associated vascular tumors in the liver depends on functional ARNT. Furthermore, we provide evidence that individual HIF transcription factors may play distinct roles in the development of specific VHL disease manifestations.

scholarly journals Hydrogen Sulfide Increases Hypoxia-inducible Factor-1 Activity Independently of von Hippel–Lindau Tumor Suppressor-1 inC. elegans

2010 ◽  
Vol 21 (1) ◽  
pp. 212-217 ◽  
Author(s):  
Mark W. Budde ◽  
Mark B. Roth
Keyword(s):  
Hydrogen Sulfide ◽  
Tumor Suppressor ◽  
Environmental Changes ◽  
Hypoxia Inducible Factor ◽  
Low Oxygen ◽  
Animal Cells ◽  
Von Hippel Lindau ◽  
C Elegans ◽  
Reporter Activity ◽  
And Behavior

Rapid alteration of gene expression in response to environmental changes is essential for normal development and behavior. The transcription factor hypoxia-inducible factor (HIF)-1 is well known to respond to alterations in oxygen availability. In nature, low oxygen environments are often found to contain high levels of hydrogen sulfide (H2S). Here, we show that Caenorhabditis elegans can have mutually exclusive responses to H2S and hypoxia, both involving HIF-1. Specifically, H2S results in HIF-1 activity throughout the hypodermis, whereas hypoxia causes HIF-1 activity in the gut as judged by a reporter for HIF-1 activity. C. elegans require hif-1 to survive in room air containing trace amounts of H2S. Exposure to H2S results in HIF-1 nuclear localization and transcription of HIF-1 targets. The effects of H2S on HIF-1 reporter activity are independent of von Hippel–Lindau tumor suppressor (VHL)-1, whereas VHL-1 is required for hypoxic regulation of HIF-1 reporter activity. Because H2S is naturally produced by animal cells, our results suggest that endogenous H2S may influence HIF-1 activity.

Sign in / Sign up

Export Citation Format

Share Document