scholarly journals Horse Clinical Cytogenetics: Recurrent Themes and Novel Findings

Animals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 831
Author(s):  
Monika Bugno-Poniewierska ◽  
Terje Raudsepp

Clinical cytogenetic studies in horses have been ongoing for over half a century and clearly demonstrate that chromosomal disorders are among the most common non-infectious causes of decreased fertility, infertility, and congenital defects. Large-scale cytogenetic surveys show that almost 30% of horses with reproductive or developmental problems have chromosome aberrations, whereas abnormal karyotypes are found in only 2–5% of the general population. Among the many chromosome abnormalities reported in the horse, most are unique or rare. However, all surveys agree that there are two recurrent conditions: X-monosomy and SRY-negative XY male-to-female sex reversal, making up approximately 35% and 11% of all chromosome abnormalities, respectively. The two are signature conditions for the horse and rare or absent in other domestic species. The progress in equine genomics and the development of molecular tools, have qualitatively improved clinical cytogenetics today, allowing for refined characterization of aberrations and understanding the underlying molecular mechanisms. While cutting-edge genomics tools promise further improvements in chromosome analysis, they will not entirely replace traditional cytogenetics, which still is the most straightforward, cost-effective, and fastest approach for the initial evaluation of potential breeding animals and horses with reproductive or developmental disorders.

2021 ◽  
Vol 53 (3) ◽  
pp. 310-317
Author(s):  
Tae-Young Choi ◽  
Tae-Ik Choi ◽  
Yu-Ri Lee ◽  
Seong-Kyu Choe ◽  
Cheol-Hee Kim

AbstractZebrafish have several advantages compared to other vertebrate models used in modeling human diseases, particularly for large-scale genetic mutant and therapeutic compound screenings, and other biomedical research applications. With the impactful developments of CRISPR and next-generation sequencing technology, disease modeling in zebrafish is accelerating the understanding of the molecular mechanisms of human genetic diseases. These efforts are fundamental for the future of precision medicine because they provide new diagnostic and therapeutic solutions. This review focuses on zebrafish disease models for biomedical research, mainly in developmental disorders, mental disorders, and metabolic diseases.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jing Zhao ◽  
Alan Blayney ◽  
Xiaorong Liu ◽  
Lauren Gandy ◽  
Weihua Jin ◽  
...  

AbstractEpigallocatechin gallate (EGCG) from green tea can induce apoptosis in cancerous cells, but the underlying molecular mechanisms remain poorly understood. Using SPR and NMR, here we report a direct, μM interaction between EGCG and the tumor suppressor p53 (KD = 1.6 ± 1.4 μM), with the disordered N-terminal domain (NTD) identified as the major binding site (KD = 4 ± 2 μM). Large scale atomistic simulations (>100 μs), SAXS and AUC demonstrate that EGCG-NTD interaction is dynamic and EGCG causes the emergence of a subpopulation of compact bound conformations. The EGCG-p53 interaction disrupts p53 interaction with its regulatory E3 ligase MDM2 and inhibits ubiquitination of p53 by MDM2 in an in vitro ubiquitination assay, likely stabilizing p53 for anti-tumor activity. Our work provides insights into the mechanisms for EGCG’s anticancer activity and identifies p53 NTD as a target for cancer drug discovery through dynamic interactions with small molecules.


Cancers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 3247
Author(s):  
Petar Brlek ◽  
Anja Kafka ◽  
Anja Bukovac ◽  
Nives Pećina-Šlaus

Diffuse gliomas are a heterogeneous group of tumors with aggressive biological behavior and a lack of effective treatment methods. Despite new molecular findings, the differences between pathohistological types still require better understanding. In this in silico analysis, we investigated AKT1, AKT2, AKT3, CHUK, GSK3β, EGFR, PTEN, and PIK3AP1 as participants of EGFR-PI3K-AKT-mTOR signaling using data from the publicly available cBioPortal platform. Integrative large-scale analyses investigated changes in copy number aberrations (CNA), methylation, mRNA transcription and protein expression within 751 samples of diffuse astrocytomas, anaplastic astrocytomas and glioblastomas. The study showed a significant percentage of CNA in PTEN (76%), PIK3AP1 and CHUK (75% each), EGFR (74%), AKT2 (39%), AKT1 (32%), AKT3 (19%) and GSK3β (18%) in the total sample. Comprehensive statistical analyses show how genomics and epigenomics affect the expression of examined genes differently across various pathohistological types and grades, suggesting that genes AKT3, CHUK and PTEN behave like tumor suppressors, while AKT1, AKT2, EGFR, and PIK3AP1 show oncogenic behavior and are involved in enhanced activity of the EGFR-PI3K-AKT-mTOR signaling pathway. Our findings contribute to the knowledge of the molecular differences between pathohistological types and ultimately offer the possibility of new treatment targets and personalized therapies in patients with diffuse gliomas.


2019 ◽  
Vol 105 (4) ◽  
pp. 384-389 ◽  
Author(s):  
Adam Jackson ◽  
Heather Ward ◽  
Rebecca Louise Bromley ◽  
Charulata Deshpande ◽  
Pradeep Vasudevan ◽  
...  

IntroductionFetal anticonvulsant syndrome (FACS) describes the pattern of physical and developmental problems seen in those children exposed to certain antiepileptic drugs (AEDs) in utero. The diagnosis of FACS is a clinical one and so excluding alternative diagnoses such as genetic disorders is essential.MethodsWe reviewed the pathogenicity of reported variants identified on exome sequencing in the Deciphering Developmental Disorders (DDD) Study in 42 children exposed to AEDs in utero, but where a diagnosis other than FACS was suspected. In addition, we analysed chromosome microarray data from 10 patients with FACS seen in a Regional Genetics Service.ResultsSeven children (17%) from the DDD Study had a copy number variant or pathogenic variant in a developmental disorder gene which was considered to explain or partially explain their phenotype. Across the AED exposure types, variants were found in 2/15 (13%) valproate exposed cases and 3/14 (21%) carbamazepine exposed cases. No pathogenic copy number variants were identified in our local sample (n=10).ConclusionsThis study is the first of its kind to analyse the exomes of children with developmental disorders who were exposed to AEDs in utero. Though we acknowledge that the results are subject to bias, a significant number of children were identified with alternate diagnoses which had an impact on counselling and management. We suggest that consideration is given to performing whole exome sequencing as part of the diagnostic work-up for children exposed to AEDs in utero.


2014 ◽  
Vol 11 (6) ◽  
pp. 371-389 ◽  
Author(s):  
Stefan Z Lutz ◽  
Harald Staiger ◽  
Andreas Fritsche ◽  
Hans-Ulrich Häring

Aims: This review is aimed at highlighting the potential mitogenic/tumour growth–promoting or antimitogenic/tumour growth–inhibiting effects of the main antihyperglycaemic drug classes. Methods: We review and discuss the most current studies evaluating the association between antidiabetic medications used in clinical practice and malignancies as described so far. Results: Metformin seems to be the only antidiabetic drug to exert protective effects both on monotherapy and also when combined with other oral antidiabetic drugs or insulins in several site-specific cancers. In contrast, several other drug classes may increase cancer risk. Some reason for concern remains regarding sulphonylureas and also the incretin-based therapies regarding pancreas and thyroid cancers and the sodium glucose cotransporter-2 inhibitors as well as pioglitazone regarding bladder cancer. The majority of meta-analyses suggest that there is no evidence for a causal relationship between insulin glargine and elevated cancer risk, although the studies have been controversially discussed. For α-glucosidase inhibitors and glinides, neutral or only few data upon cancer risk exist. Conclusion: Although the molecular mechanisms are not fully understood, a potential risk of mitogenicity and tumour growth promotion cannot be excluded in case of several antidiabetic drug classes. However, more large-scale, randomized, well-designed clinical studies with especially long follow-up time periods are needed to get reliable answers to these safety issues.


2021 ◽  
Vol 135 (24) ◽  
pp. 2691-2708
Author(s):  
Simon T. Bond ◽  
Anna C. Calkin ◽  
Brian G. Drew

Abstract The escalating prevalence of individuals becoming overweight and obese is a rapidly rising global health problem, placing an enormous burden on health and economic systems worldwide. Whilst obesity has well described lifestyle drivers, there is also a significant and poorly understood component that is regulated by genetics. Furthermore, there is clear evidence for sexual dimorphism in obesity, where overall risk, degree, subtype and potential complications arising from obesity all differ between males and females. The molecular mechanisms that dictate these sex differences remain mostly uncharacterised. Many studies have demonstrated that this dimorphism is unable to be solely explained by changes in hormones and their nuclear receptors alone, and instead manifests from coordinated and highly regulated gene networks, both during development and throughout life. As we acquire more knowledge in this area from approaches such as large-scale genomic association studies, the more we appreciate the true complexity and heterogeneity of obesity. Nevertheless, over the past two decades, researchers have made enormous progress in this field, and some consistent and robust mechanisms continue to be established. In this review, we will discuss some of the proposed mechanisms underlying sexual dimorphism in obesity, and discuss some of the key regulators that influence this phenomenon.


2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Paola Brescia ◽  
Cristina Richichi ◽  
Giuliana Pelicci

Cancer stem cells (CSCs) were isolated in multiple tumor types, including human glioblastomas, and although the presence of surface markers selectively expressed on CSCs can be used to isolate them, no marker/pattern of markers are sufficiently robust to definitively identify stem cells in tumors. Several markers were evaluated for their prognostic value with promising early results, however none of them was proven to be clinically useful in large-scale studies, leading to outstanding efforts to identify new markers. Given the heterogeneity of human glioblastomas further investigations are necessary to identify both cancer stem cell-specific markers and the molecular mechanisms sustaining the tumorigenic potential of these cells to develop tailored treatments. Markers for glioblastoma stem cells such as CD133, CD15, integrin-α6, L1CAM might be informative to identify these cells but cannot be conclusively linked to a stem cell phenotype. Overlap of expression, functional state and morphology of different subpopulations lead to carefully consider the techniques employed so far to isolate these cells. Due to a dearth of methods and markers reliably identifying the candidate cancer stem cells, the isolation/enrichment of cancer stem cells to be therapeutically targeted remains a major challenge.


2018 ◽  
Author(s):  
Jieqiong Qu ◽  
Sabine Tanis ◽  
Jos P.H. Smits ◽  
Evelyn N. Kouwenhoven ◽  
Martin Oti ◽  
...  

AbstractTranscription factor p63 is a key regulator of epidermal keratinocyte proliferation and differentiation. In humans mutations in p63 cause several developmental disorders with defects of ectoderm-derived structures including the epidermis. The underlying molecular mechanisms of these mutations however remain unclear. Here we characterized the transcriptome and epigenome from EEC syndrome patients carrying mutations in the p63 DNA-binding domain. The transcriptome of p63 mutant keratinocytes deviated from the normal epidermal cell identity. Epigenomic analyses showed that the deregulated gene expression in p63 mutant keratinocytes resulted from an altered enhancer landscape contributed by loss of p63-bound active enhancers and by unexpected gain of enhancers. The gained enhancers in mutant keratinocytes were frequently bound by deregulated transcription factors such as RUNX1. Reversing RUNX1 overexpression partially rescued deregulated gene expression as well as the enhancer distribution. Our findings support the pivotal role of p63 in controlling the enhancer landscape of epidermal keratinocytes and identify a novel mechanism whereby p63 DNA-binding mutations associated with EEC syndrome rewire the enhancer landscape and affect epidermal cell identity.


2020 ◽  
Author(s):  
Spencer G. Gordon ◽  
Lisa E. Kursel ◽  
Kewei Xu ◽  
Ofer Rog

AbstractDuring sexual reproduction the parental homologous chromosomes find each other (pair) and align along their lengths by integrating local sequence homology with large-scale contiguity, thereby allowing for precise exchange of genetic information. The Synaptonemal Complex (SC) is a conserved zipper-like structure that assembles between the homologous chromosomes. This phase-separated interface brings chromosomes together and regulates exchanges between them. However, the molecular mechanisms by which the SC carries out these functions remain poorly understood. Here we isolated and characterized two mutations in the dimerization interface in the middle of the SC zipper in C. elegans. The mutations perturb both chromosome alignment and the regulation of genetic exchanges. Underlying the chromosome-scale phenotypes are distinct alterations to the way SC subunits interact with one another. We propose that the SC brings homologous chromosomes together through two biophysical activities: obligate dimerization that prevents assembly on unpaired chromosomes; and a tendency to phase-separate that extends pairing interactions along the entire length of the chromosomes.


2019 ◽  
Author(s):  
Alessandro Greco ◽  
Jon Sanchez Valle ◽  
Vera Pancaldi ◽  
Anaïs Baudot ◽  
Emmanuel Barillot ◽  
...  

AbstractMatrix Factorization (MF) is an established paradigm for large-scale biological data analysis with tremendous potential in computational biology.We here challenge MF in depicting the molecular bases of epidemiologically described Disease-Disease (DD) relationships. As use case, we focus on the inverse comorbidity association between Alzheimer’s disease (AD) and lung cancer (LC), described as a lower than expected probability of developing LC in AD patients. To the day, the molecular mechanisms underlying DD relationships remain poorly explained and their better characterization might offer unprecedented clinical opportunities.To this goal, we extend our previously designed MF-based framework for the molecular characterization of DD relationships. Considering AD-LC inverse comorbidity as a case study, we highlight multiple molecular mechanisms, among which the previously identified immune system and mitochondrial metabolism. We then discriminate mechanisms specific to LC from those shared with other cancers through a pancancer analysis. Additionally, new candidate molecular players, such as Estrogen Receptor (ER), CDH1 and HDAC, are pinpointed as factors that might underlie the inverse relationship, opening the way to new investigations. Finally, some lung cancer subtype-specific factors are also detected, suggesting the existence of heterogeneity across patients also in the context of inverse comorbidity.


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