scholarly journals Pterygium—The Good, the Bad, and the Ugly

Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1567
Author(s):  
Sara I. Van Acker ◽  
Bert Van den Bogerd ◽  
Michel Haagdorens ◽  
Vasiliki Siozopoulou ◽  
Sorcha Ní Dhubhghaill ◽  
...  
Keyword(s):  
Dna Damage ◽  
Molecular Level ◽  
The Self ◽  
Grading System ◽  
Ocular Surface Squamous Neoplasia ◽  
True Nature ◽  
Intervention Point ◽  
Pathological Evaluation ◽  
Repair Mechanisms ◽  
Life Threatening

Pterygium is a multifaceted pathology that displays apparent conflicting characteristics: benign (e.g., self-limiting and superficial), bad (e.g., proliferative and potentially recurrent) and ugly (e.g., signs of preneoplastic transformation). The natural successive question is: why are we lacking reports showing that pterygium lesions become life-threatening through metastasis, especially since pterygium has considerable similarities with UV-related malignancies on the molecular level? In this review, we consider how our pathophysiological understanding of the benign pterygium pathology overlaps with ocular surface squamous neoplasia and skin cancer. The three UV-related disorders share the same initial insult (i.e., UV radiation) and responsive repair mechanisms to the ensuing (in)direct DNA damage. Their downstream apoptotic regulators and other cellular adaptations are remarkably alike. However, a complicating factor in understanding the fine line between the self-limiting nature of pterygium and the malignant transformation in other UV-related diseases is the prominent ambiguity in the pathological evaluation of pterygium biopsies. Features of preneoplastic transformation (i.e., dysplasia) are used to define normal cellular reactions (i.e., atypia and metaplasia) and vice versa. A uniform grading system could help in unraveling the true nature of this ancient disease and potentially help in identifying the earliest intervention point possible regarding the cellular switch that drives a cell’s fate towards cancer.

Bestimmung der DNA-Schädigung in vitro

2010 ◽  
Vol 49 (S 01) ◽  
pp. S64-S68
Author(s):  
E. Dikomey
Keyword(s):  
Dna Damage ◽  
Cell Lines ◽  
Chromosome Aberrations ◽  
Genetic Factors ◽  
Double Strand Breaks ◽  
Strand Breaks ◽  
Cell Inactivation ◽  
Repair Mechanisms ◽  
Break Repair

SummaryIonising irradiation acts primarily via induction of DNA damage, among which doublestrand breaks are the most important lesions. These lesions may lead to lethal chromosome aberrations, which are the main reason for cell inactivation. Double-strand breaks can be repaired by several different mechanisms. The regulation of these mechanisms appears be fairly different for normal and tumour cells. Among different cell lines capacity of doublestrand break repair varies by only few percents and is known to be determined mostly by genetic factors. Knowledge about doublestrand break repair mechanisms and their regulation is important for the optimal application of ionising irradiation in medicine.

Riboflavin and UV-Light Based Pathogen Reduction: Extent and Consequence of DNA Damage at the Molecular Level

2004 ◽  
Vol 80 (1) ◽  
pp. 15 ◽  
Author(s):  
Vijay Kumar ◽  
Owen Lockerbie ◽  
Shawn D. Keil ◽  
Patrick H. Ruane ◽  
Matthew S. Platz ◽  
...  
Keyword(s):  
Dna Damage ◽  
Molecular Level ◽  
Uv Light ◽  
Pathogen Reduction

scholarly journals Treatment and therapeutic strategies for pituitary apoplexy in pregnancy: a case series

2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Yuya Kato ◽  
Yoshikazu Ogawa ◽  
Teiji Tominaga
Keyword(s):  
Pituitary Apoplexy ◽  
Clinical Symptoms ◽  
Case Series ◽  
Optimal Timing ◽  
Presenting Symptoms ◽  
Pathological Evaluation ◽  
Mother And Child ◽  
Life Threatening ◽  
In Pregnancy

Abstract Background Pregnancy is a known risk factor for pituitary apoplexy, which is life threatening for both mother and child. However, very few clinical interventions have been proposed for managing pituitary apoplexy in pregnancy. Case presentation We describe the management of three cases of pituitary apoplexy during pregnancy and review available literature. Presenting symptoms in our case series were headache and/or visual disturbances, and the etiology in all cases was hemorrhage. Conservative therapy was followed until 34 weeks of gestation, after which babies were delivered by cesarean section with prophylactic bolus hydrocortisone supplementation. Tumor removal was only electively performed after delivery using the transsphenoidal approach. All three patients and their babies had a good clinical course, and postoperative pathological evaluation revealed that all tumors were functional and that they secreted prolactin. Conclusions Although the mechanism of pituitary apoplexy occurrence remains unknown, the most important treatment strategy for pituitary apoplexy in pregnancy remains adequate hydrocortisone supplementation and frequent hormonal investigation. Radiological follow-up should be performed only if clinical symptoms deteriorate, and optimal timing for surgical resection should be discussed by a multidisciplinary team that includes obstetricians and neonatologists.

scholarly journals Platinum Complexes in Colorectal Cancer and Other Solid Tumors

Cancers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 2073
Author(s):  
Beate Köberle ◽  
Sarah Schoch
Keyword(s):  
Colorectal Cancer ◽  
Dna Damage ◽  
Dna Repair ◽  
Cancer Cells ◽  
Cisplatin Resistance ◽  
Platinum Complexes ◽  
Dna Lesions ◽  
Dna Damage Signaling ◽  
Repair Mechanisms ◽  
P53 Inactivation

Cisplatin is one of the most commonly used drugs for the treatment of various solid neoplasms, including testicular, lung, ovarian, head and neck, and bladder cancers. Unfortunately, the therapeutic efficacy of cisplatin against colorectal cancer is poor. Various mechanisms appear to contribute to cisplatin resistance in cancer cells, including reduced drug accumulation, enhanced drug detoxification, modulation of DNA repair mechanisms, and finally alterations in cisplatin DNA damage signaling preventing apoptosis in cancer cells. Regarding colorectal cancer, defects in mismatch repair and altered p53-mediated DNA damage signaling are the main factors controlling the resistance phenotype. In particular, p53 inactivation appears to be associated with chemoresistance and poor prognosis. To overcome resistance in cancers, several strategies can be envisaged. Improved cisplatin analogues, which retain activity in resistant cancer, might be applied. Targeting p53-mediated DNA damage signaling provides another therapeutic strategy to circumvent cisplatin resistance. This review provides an overview on the DNA repair pathways involved in the processing of cisplatin damage and will describe signal transduction from cisplatin DNA lesions, with special attention given to colorectal cancer cells. Furthermore, examples for improved platinum compounds and biochemical modulators of cisplatin DNA damage signaling will be presented in the context of colon cancer therapy.

scholarly journals DNA Damage Response in Multiple Myeloma: The Role of the Tumor Microenvironment

Cancers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 504
Author(s):  
Takayuki Saitoh ◽  
Tsukasa Oda
Keyword(s):  
Multiple Myeloma ◽  
Dna Damage ◽  
Dna Repair ◽  
Tumor Microenvironment ◽  
Dna Damage Response ◽  
Genetic Instability ◽  
Dna Repair Mechanisms ◽  
Damage Response ◽  
Repair Mechanisms

Multiple myeloma (MM) is an incurable plasma cell malignancy characterized by genomic instability. MM cells present various forms of genetic instability, including chromosomal instability, microsatellite instability, and base-pair alterations, as well as changes in chromosome number. The tumor microenvironment and an abnormal DNA repair function affect genetic instability in this disease. In addition, states of the tumor microenvironment itself, such as inflammation and hypoxia, influence the DNA damage response, which includes DNA repair mechanisms, cell cycle checkpoints, and apoptotic pathways. Unrepaired DNA damage in tumor cells has been shown to exacerbate genomic instability and aberrant features that enable MM progression and drug resistance. This review provides an overview of the DNA repair pathways, with a special focus on their function in MM, and discusses the role of the tumor microenvironment in governing DNA repair mechanisms.

scholarly journals Ancient Sturgeons Possess Effective DNA Repair Mechanisms: Influence of Model Genotoxicants on Embryo Development of Sterlet, Acipenser ruthenus

2020 ◽  
Vol 22 (1) ◽  
pp. 6
Author(s):  
Ievgeniia Gazo ◽  
Roman Franěk ◽  
Radek Šindelka ◽  
Ievgen Lebeda ◽  
Sahana Shivaramu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Damage ◽  
Dna Repair ◽  
Embryo Development ◽  
Hatching Rate ◽  
Embryo Survival ◽  
Dna Repair Mechanisms ◽  
Acipenser Ruthenus ◽  
Repair Mechanisms ◽  
Sterlet Acipenser Ruthenus

DNA damage caused by exogenous or endogenous factors is a common challenge for developing fish embryos. DNA damage repair (DDR) pathways help organisms minimize adverse effects of DNA alterations. In terms of DNA repair mechanisms, sturgeons represent a particularly interesting model due to their exceptional genome plasticity. Sterlet (Acipenser ruthenus) is a relatively small species of sturgeon. The goal of this study was to assess the sensitivity of sterlet embryos to model genotoxicants (camptothecin, etoposide, and benzo[a]pyrene), and to assess DDR responses. We assessed the effects of genotoxicants on embryo survival, hatching rate, DNA fragmentation, gene expression, and phosphorylation of H2AX and ATM kinase. Exposure of sterlet embryos to 1 µM benzo[a]pyrene induced low levels of DNA damage accompanied by ATM phosphorylation and xpc gene expression. Conversely, 20 µM etoposide exposure induced DNA damage without activation of known DDR pathways. Effects of 10 nM camptothecin on embryo development were stage-specific, with early stages, before gastrulation, being most sensitive. Overall, this study provides foundational information for future investigation of sterlet DDR pathways.

scholarly journals DNA Damage and DNA Damage Response in Chronic Myeloid Leukemia

2020 ◽  
Vol 21 (4) ◽  
pp. 1177 ◽  
Author(s):  
Popp ◽  
Kohl ◽  
Naumann ◽  
Flach ◽  
Brendel ◽  
...  
Keyword(s):  
Dna Damage ◽  
Chronic Myeloid Leukemia ◽  
Dna Damage Response ◽  
Myeloid Leukemia ◽  
Molecular Response ◽  
Blastic Transformation ◽  
Γh2ax Foci ◽  
Damage Response ◽  
Nhej Repair ◽  
Repair Mechanisms

DNA damage and alterations in the DNA damage response (DDR) are critical sources of genetic instability that might be involved in BCR-ABL1 kinase-mediated blastic transformation of chronic myeloid leukemia (CML). Here, increased DNA damage is detected by γH2AX foci analysis in peripheral blood mononuclear cells (PBMCs) of de novo untreated chronic phase (CP)-CML patients (n = 5; 2.5 γH2AX foci per PBMC ± 0.5) and blast phase (BP)-CML patients (n = 3; 4.4 γH2AX foci per PBMC ± 0.7) as well as CP-CML patients with loss of major molecular response (MMR) (n = 5; 1.8 γH2AX foci per PBMC ± 0.4) when compared to DNA damage in PBMC of healthy donors (n = 8; 1.0 γH2AX foci per PBMC ± 0.1) and CP-CML patients in deep molecular response or MMR (n = 26; 1.0 γH2AX foci per PBMC ± 0.1). Progressive activation of erroneous non-homologous end joining (NHEJ) repair mechanisms during blastic transformation in CML is indicated by abundant co-localization of γH2AX/53BP1 foci, while a decline of the DDR is suggested by defective expression of (p-)ATM and (p-)CHK2. In summary, our data provide evidence for the accumulation of DNA damage in the course of CML and suggest ongoing DNA damage, erroneous NHEJ repair mechanisms, and alterations in the DDR as critical mediators of blastic transformation in CML.

scholarly journals The emerging role of RNAs in DNA damage repair

2017 ◽  
Vol 24 (4) ◽  
pp. 580-587 ◽  
Author(s):  
Ben R Hawley ◽  
Wei-Ting Lu ◽  
Ania Wilczynska ◽  
Martin Bushell
Keyword(s):  
Dna Damage ◽  
Dna Repair ◽  
Critical Role ◽  
Repair Process ◽  
Rna Molecules ◽  
Processing Enzymes ◽  
Damage Repair ◽  
New Findings ◽  
Integral Role ◽  
Repair Mechanisms

Abstract Many surveillance and repair mechanisms exist to maintain the integrity of our genome. All of the pathways described to date are controlled exclusively by proteins, which through their enzymatic activities identify breaks, propagate the damage signal, recruit further protein factors and ultimately resolve the break with little to no loss of genetic information. RNA is known to have an integral role in many cellular pathways, but, until very recently, was not considered to take part in the DNA repair process. Several reports demonstrated a conserved critical role for RNA-processing enzymes and RNA molecules in DNA repair, but the biogenesis of these damage-related RNAs and their mechanisms of action remain unknown. We will explore how these new findings challenge the idea of proteins being the sole participants in the response to DNA damage and reveal a new and exciting aspect of both DNA repair and RNA biology.

scholarly journals DNA Repair: Exploiting the Fanconi Anemia Pathway As a Potential Therapeutic Target

2011 ◽  
pp. 453-465 ◽  
Author(s):  
T. HUCL ◽  
E. GALLMEIER
Keyword(s):  
Dna Damage ◽  
Dna Repair ◽  
Fanconi Anemia ◽  
Cancer Susceptibility ◽  
Synthetic Lethality ◽  
Bone Marrow Failure ◽  
Long Term Effects ◽  
Alternative Pathways ◽  
Repair Mechanisms ◽  
Relationship Of

DNA repair is an active cellular process to respond to constant DNA damage caused by metabolic processes and environmental factors. Since the outcome of DNA damage is generally adverse and long term effects may contribute to oncogenesis, cells have developed a variety of DNA repair mechanisms, which operate depending on the type of DNA damage inflicted. At least 15 Fanconi anemia (FA) proteins interact in a common pathway involved in homologous recombination. Inherited homozygous mutations in any of these FA genes cause a rare disease, Fanconi anemia, characterized by congenital abnormalities, progressive bone-marrow failure and cancer susceptibility. Heterozygous germline FA mutations predispose to various types of cancer. In addition, somatic FA mutations have been identified in diverse cancer types. Evidence exists that cells deficient in the FA pathway become dependent on alternative pathways for survival. Additional inhibition of such alternative pathways is thus expected to result in cell death, creating a relationship of synthetic lethality. Identifying these relationships can reveal yet unknown mechanisms of DNA repair and new targets for therapy.

scholarly journals An Overview on the Therapeutic Function of Foods Enriched with Plant Sterols in Diabetes Management

Antioxidants ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1903
Author(s):  
Selvaraj Jayaraman ◽  
Anitha Roy ◽  
Srinivasan Vengadassalapathy ◽  
Ramya Sekar ◽  
Vishnu Priya Veeraraghavan ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Side Effects ◽  
Diabetes Management ◽  
Plant Sterols ◽  
Insulin Metabolism ◽  
Food Ingredients ◽  
Conventional Drug ◽  
Repair Mechanisms ◽  
Life Threatening ◽  
Stress Damage

Diabetes is one of the most significant health issues across the world. People identified with diabetes are more vulnerable to various infections and are at a greater risk of developing cardiovascular diseases. The plant-based food we consume often contains many sterol-based bioactive compounds. It is well documented that these compounds could effectively manage the processes of insulin metabolism and cholesterol regulation. Insulin resistance followed by hyperglycemia often results in oxidative stress level enhancement and increased reactive oxygen species production. At the molecular level, these changes induce apoptosis in pancreatic cells and hence lead to insulin insufficiency. Studies have proved that plant sterols can lower inflammatory and oxidative stress damage connected with DNA repair mechanisms. The effective forms of phyto compounds are polyphenols, terpenoids, and thiols abundant in vegetables, fruits, nuts, and seeds. The available conventional drug-based therapies for the prevention and management of diabetes are time-consuming, costly, and with life-threatening side effects. Thereby, the therapeutic management of diabetes with plant sterols available in our daily diet is highly welcome as there are no side effects. This review intends to offer an overview of the present scenario of the anti-diabetic compounds from food ingredients towards the therapeutic beneficial against diabetes.

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