scholarly journals Effects of male telomeres on probability of paternity in sand lizards

2018 ◽  
Vol 14 (8) ◽  
pp. 20180033 ◽  
Author(s):  
Angela Pauliny ◽  
Emily Miller ◽  
Nicky Rollings ◽  
Erik Wapstra ◽  
Donald Blomqvist ◽  
...  
Keyword(s):  
Experimental Data ◽  
Dna Damage ◽  
Sperm Competition ◽  
Telomere Length ◽  
Sperm Motility ◽  
Female Identity ◽  
Laboratory Population ◽  
Lacerta Agilis

Standardized swim-up trials are used in in vitro fertilization clinics to select particularly motile spermatozoa in order to increase the probability of a successful fertilization. Such trials demonstrate that sperm with longer telomeres have higher motility and lower levels of DNA damage. Regardless of whether sperm motility, and successful swim-up to fertilization sites, is a direct or correlational effect of telomere length or DNA damage, covariation between telomere length and sperm performance predicts a relationship between telomere length and probability of paternity in sperm competition, a prediction that for ethical reasons cannot be tested on humans. Here, we test this prediction in sand lizards ( Lacerta agilis ) using experimental data from twice-mated females in a laboratory population, and telomere length in blood from the participating lizards. Female identity influenced paternity (while the mechanism was not identified), while relatively longer male telomeres predicted higher probability of paternity. We discuss potential mechanisms underpinning this result.

Telomerase interference in combination with docetaxel therapy for maximal prostate cancer inhibition: In vitro data for a novel therapeutic approach

2009 ◽  
Vol 27 (15_suppl) ◽  
pp. e14596-e14596
Author(s):  
D. Sahu ◽  
T. Xu ◽  
R. Lau ◽  
L. Xue ◽  
A. Goldkorn
Keyword(s):  
Prostate Cancer ◽  
Dna Damage ◽  
Vector Control ◽  
Telomere Length ◽  
Statistical Significance ◽  
Telomerase Activity ◽  
Telomerase Rna ◽  
Castration Resistant Prostate Cancer ◽  
Novel Therapeutic

e14596 Background: Metastatic castration-resistant prostate cancer (mCRPC) carries a median survival of 18 months with standard docetaxel based therapies. Telomerase interference (TI) is a promising novel therapeutic strategy that exploits the high telomerase activity in cancer cells by introducing a mutated telomerase RNA (MT-Ter) that encodes toxic telomeres and rapidly induces apoptosis. We investigated whether TI can be combined with docetaxel therapy to achieve greater growth inhibition in mCRPC. Methods: PC3 and DU145 mCRPC cell lines were treated with docetaxel in the presence of TI or vector control. TI was accomplished by concurrent lentiviral expression of 2 constructs: telomerase RNA with an altered template region (MT-Ter) and siRNA targeting wild-type telomerase RNA (anti-Ter siRNA). Telomere length and telomerase activity were assessed using RT-PCR and TRAP, respectively. Proliferation, apoptosis, and DNA damage were quantified using MTS, TUNEL, and 53bp1 staining, respectively. Statistical significance was calculated using a 2-sided t-test. Results: Docetaxel (10nM) induced 22% inhibition (p=0.01) of PC3 proliferation in the presence of vector control and 41% inhibition (p=0.001) in the presence of TI (results were similar in DU145 cells). This near-doubling of efficacy was attributable to an independent inhibitory effect (17% inhibition, p=0.04) from TI treatment alone, which occurred without change in bulk telomere length or telomerase activity. TI alone generated increased numbers of DNA damage foci (7/cell vs. 2/cell with vector control) while docetaxel alone did not generate significant increases in DNA damage. Both TI and docetaxel induced a marked increase in the rate of apoptosis. Conclusions: Docetaxel and TI each exerted a pro-apoptotic effect which, when combined, produced an additive inhibition of mCRPC proliferation. TI-mediated apoptosis ensued from DNA damage, consistent with its known telomeric-uncapping effect, while docetaxel-induced apoptosis was not associated with direct DNA damage, also consistent with known docetaxel mechanisms of action. These findings underscore the therapeutic promise of combining standard agents with TI to improve efficacy and reduce toxicity. No significant financial relationships to disclose.

The Telomerase Inhibitor RHPS4 Induces Telomere Shortening, DNA-Damage and Cell Death in AML Cells and Chemosensitises Cells to Daunorubicin.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 2760-2760
Author(s):  
Monica Pallis ◽  
Dotun Ojo ◽  
Jaineeta Richardson ◽  
John Ronan ◽  
Malcolm Stevens ◽  
...  
Keyword(s):  
Dna Damage ◽  
Cell Death ◽  
Telomere Length ◽  
Progenitor Cells ◽  
Cell Lines ◽  
Dna Damage Response ◽  
Cell Types ◽  
Telomere Shortening ◽  
Damage Response

Abstract Abstract 2760 Poster Board II-736 The quadruplex ligand RHPS4 is the lead compound in a drug discovery program at the University of Nottingham. It has been shown to bind to telomeres and inhibit telomerase, and subsequently induces growth arrest in progenitor cells from cancer cell lines whilst sparing normal haematopoietic progenitor cells. We explored its in vitro effects in AML cells, which are reported generally to have considerably shorter telomeres than normal CD34+ cells. AML cell lines were grown for 21 days in suspension culture. Primary samples were cultured for 14 days in semi-solid medium. Telomere length was measured by Southern blotting. γH2A.X was used to identify a DNA damage response, and cell viability was measured flow cytometrically with 7-amino actinomycin D. As reported in other tumour cell types, sensitivity to RHPS4 was found to be greatest in those AML cells with the shortest telomeres. In the OCI-AML3 cell line 0.3 μM RHPS4 inhibited cell growth by 50% in a 21 day clonogenic assay, accompanied by shortening of telomeres from 2.6 Kb to <1 Kb. Molm 13 cells (initial telomere length 3.2kB) also underwent telomere shortening in the presence of 0.3 μM RHPS4 (2.8Kb), whereas TF1a and U937 (both with initial telomere lengths approximately 6.5 kB) were insensitive at that concentration. After 6 days at 0.3 μM, RHPS4 was cytostatic, but at higher concentrations (1 μM) the drug was found to induce a substantial DNA damage response and loss of viability to OCI-AML3 cells. Moreover 0.3 μM RHPS4 enhanced the γH2A.X expression and cell death induced by the chemotherapy drug daunorubicin in these cells. Using 14 day clonogenic assays in primary AML samples (n=6), we found that the IC50 for RHPS4 alone was 0.7 μM. However, in the presence of 0.3 μM RHPS4, the median IC50 to daunorubicin was reduced from 19 nM to 5.5 nM. In conclusion we have determined that RHPS4 has telomere-shortening, cytostatic, cytotoxic and chemosensitising properties in AML cells. Disclosures: Stevens: Pharminox Ltd: director and shareholder of Pharminox Ltd which has a financial interest in RHPS4.

RHPS4, An Anti-Telomere Agent, Specifically Targets the Subgroup of AML Cells with Loss or Gain of Parts of Chromosomes.

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 1195-1195
Author(s):  
Monica Pallis ◽  
Simone Clarke ◽  
Martin Grundy ◽  
Jaineeta Richardson ◽  
Dotun Ojo ◽  
...  
Keyword(s):  
Dna Damage ◽  
Telomere Length ◽  
Conflicts Of Interest ◽  
Poor Response ◽  
Damage Mechanism ◽  
Additional Material ◽  
Telomere Shortening ◽  
Growth And Survival ◽  
Exact Test

Abstract Abstract 1195 Cytogenetic abnormalities vary greatly in AML and those with gains and losses of chromosome parts, terminal deletions and whole chromosome losses could theoretically derive from telomere dysfunction. Cells with these abnormalities are characterised by telomere shortening and abnormal function characterised by activation of both the negative telomere regulator TRF1 and also of hTERT. The G quadruplex ligand RHPS4 (Pharminox Ltd, Biocity, Nottingham, UK) binds telomeres and induces DNA damage at higher doses in the short term and critical telomere shortening in longer term growth assays. We have previously reported cytostatic and cytotoxic effects for this agent in AML cell lines, whilst others have found that normal haematopoietic progenitor cells are not targeted. We have now examined effects of RHPS4 on the in vitro growth and survival of primary AML cells, comprising 9 samples with normal and 8 with abnormal karyotypes (5 complex, one -7, one 5q- and one with additional material on chromosomes 2 and 9). Cells were incubated with RHPS4 in standard 14 day colony assays and for 7 and 21 days in a novel suspension culture medium supplemented with supernatant from cultured normal human osteoblasts. In the 7 day cultures, no effects were observed on cell survival. In the longer term growth assays, a submicromolar IC50 for RHPS4 was observed in 7/8 samples with aberrant cytogenetics in contrast with only 1/9 with normal cytogenetics (P=0.003, Fisher's exact test). Furthermore, RHPS4 significantly sensitised samples with abnormal cytogenetics to daunorubicin reducing the median IC50 from 27nM to 10nM (n=8, p<0.05). A qPCR method was used to measure telomere length of untreated DNA from 15 of the samples; the qPCR assay had previously been performed in a separate patient cohort alongside a Southern technique and comparable values were attained for the two different methods. There were no significant differences in telomere lengths between the normal and abnormal cytogenetic groups suggestive that telomere length is not a determinant of RHPS4 sensitivity in these assays. Samples with adverse cytogenetics have previously been associated with an up-regulation of basal DNA damage markers and may therefore be sensitive to compounds that can exacerbate levels of damage. We therefore studied the levels of p-ATM by immunocytochemistry in RHPS4-treated cells and found a significant increase compared to untreated cells - hence RHPS4 may be acting via a DNA damage mechanism. We conclude that telomere targeting has exciting potential as therapy for a subset of AML patients including those with adverse cytogenetics who have a poor response to conventional chemotherapeutics. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Respiratory Mitochondrial Efficiency and DNA Oxidation in Human Sperm after In Vitro Myo-Inositol Treatment

2020 ◽  
Vol 9 (6) ◽  
pp. 1638 ◽  
Author(s):  
Laura Governini ◽  
Rosetta Ponchia ◽  
Paolo Giovanni Artini ◽  
Elena Casarosa ◽  
Ilaria Marzi ◽  
...  
Keyword(s):  
Dna Damage ◽  
Oxidative Phosphorylation ◽  
Oxidative Damage ◽  
Sperm Motility ◽  
Semen Quality ◽  
Sperm Quality ◽  
Antioxidant Properties ◽  
Atp Production ◽  
In Vitro Treatment

Semen samples are known to contain abnormal amounts of reactive oxygen species (ROS) and oxygen free radicals; therefore, the identification of antioxidant molecules able to counteract the oxidative damage caused by ROS is foresight. Indeed, improving semen quality in terms of motility and reduction in DNA damage, can significantly improve the fertilization potential of sperm in vitro. To this regard, myo-inositol, based on its antioxidant properties, has been reported to be effective in improving sperm quality and motility in oligoasthenozoospermic patients undergoing assisted reproduction techniques when used as a dietary supplementation. Moreover, in vitro treatment demonstrated a direct relationship between myo-inositol, mitochondrial membrane potential and sperm motility. This experimental study aimed to evaluate the effects of myo-inositol (Andrositol-lab) in vitro treatment on sperm motility, capacitation, mitochondrial oxidative phosphorylation and DNA damage. Our results demonstrate that myo-inositol induces a significant increase in sperm motility and in oxygen consumption, the main index of oxidative phosphorylation efficiency and ATP production, both in basal and in in vitro capacitated samples. Moreover, we provide evidence for a significant protective role of myo-inositol against oxidative damage to DNA, thus supporting the in vitro use of myo-inositol in assisted reproductive techniques. Even if further studies are needed to clarify the mechanisms underlying the antioxidant properties of myo-inositol, the present findings significantly extend our knowledge on human male fertility and pave the way to the definition of evidence-based guidelines, aiming to improve the in vitro procedure currently used in ART laboratory for sperm selection.

scholarly journals Primary high-grade serous ovarian cancer cells are sensitive to senescence induced by carboplatin and paclitaxel in vitro

2021 ◽  
Vol 26 (1) ◽  
Author(s):  
Paweł Uruski ◽  
Agnieszka Sepetowska ◽  
Corinna Konieczna ◽  
Martyna Pakuła ◽  
Michał Wyrwa ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Ovarian Cancer ◽  
Dna Damage ◽  
Cancer Cells ◽  
Telomere Length ◽  
Telomerase Activity ◽  
Ovarian Cancer Cells ◽  
High Grade ◽  
Serous Ovarian Cancer

Abstract Background Various types of normal and cancer cells undergo senescence in response to carboplatin and paclitaxel, which are considered the gold standard treatments in ovarian cancer management. Surprisingly, the effect of these drugs on ovarian cancer cell senescence remained unknown. Methods The experiments were conducted on primary high-grade serous ovarian cancer cells. Molecular markers of senescence were evaluated using cytochemistry and immunofluorescence. Cell cycle distribution was analyzed using flow cytometry. Expression of cyclins and signaling pathways was tested using western blot. Telomere length and telomerase activity were measured using qPCR, and the colocalization of telomeres with DNA damage foci using immuno-FISH. Oxidative stress-related parameters were quantified using appropriate fluorescence probes. Production of cancerogenic agents was analyzed using qPCR and ELISA. Results Carboplatin applied with paclitaxel induces senescence of ovarian cancer cells in vitro. This activity was reflected by permanent G2/M growth arrest, a high fraction of cells expressing senescence biomarkers (SA-β-Gal and γ-H2A.X), upregulated expression of p16, p21, and p53 cell cycle inhibitors, and decreased expression of cyclin B1. Neither telomere length nor telomerase activity changed in the senescent cells, and the majority of DNA damage was localized outside telomeres. Moreover, drug-treated cancer cells exhibited increased production of STAT3 protein, overproduced superoxide and peroxides, and increased mitochondrial mass. They were also characterized by upregulated ANG1, CCL11, IL-6, PDGF-D, TIMP-3, TSP-1, and TGF-β1 at the mRNA and/or protein level. Conclusions Our findings imply that conventional chemotherapy may elicit senescence in ovarian cancer cells, which may translate to the development of a cancer-promoting phenotype, despite the inability of these cells to divide.

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.

Non-canonical Functions of Telomerase Reverse Transcriptase: Emerging Roles and Biological Relevance

2020 ◽  
Vol 20 (6) ◽  
pp. 498-507 ◽  
Author(s):  
Connor A.H. Thompson ◽  
Judy M.Y. Wong
Keyword(s):  
Oxidative Stress ◽  
Dna Damage ◽  
Reverse Transcriptase ◽  
Cancer Cells ◽  
Telomere Length ◽  
Telomere Maintenance ◽  
Telomerase Reverse Transcriptase ◽  
Alternative Mechanism ◽  
Dependent Manner ◽  
Mitochondrial Integrity

Increasing evidence from research on telomerase suggests that in addition to its catalytic telomere repeat synthesis activity, telomerase may have other biologically important functions. The canonical roles of telomerase are at the telomere ends where they elongate telomeres and maintain genomic stability and cellular lifespan. The catalytic protein component Telomerase Reverse Transcriptase (TERT) is preferentially expressed at high levels in cancer cells despite the existence of an alternative mechanism for telomere maintenance (alternative lengthening of telomeres or ALT). TERT is also expressed at higher levels than necessary for maintaining functional telomere length, suggesting other possible adaptive functions. Emerging non-canonical roles of TERT include regulation of non-telomeric DNA damage responses, promotion of cell growth and proliferation, acceleration of cell cycle kinetics, and control of mitochondrial integrity following oxidative stress. Non-canonical activities of TERT primarily show cellular protective effects, and nuclear TERT has been shown to protect against cell death following double-stranded DNA damage, independent of its role in telomere length maintenance. TERT has been suggested to act as a chromatin modulator and participate in the transcriptional regulation of gene expression. TERT has also been reported to regulate transcript levels through an RNA-dependent RNA Polymerase (RdRP) activity and produce siRNAs in a Dicer-dependent manner. At the mitochondria, TERT is suggested to protect against oxidative stress-induced mtDNA damage and promote mitochondrial integrity. These extra-telomeric functions of TERT may be advantageous in the context of increased proliferation and metabolic stress often found in rapidly-dividing cancer cells. Understanding the spectrum of non-canonical functions of telomerase may have important implications for the rational design of anti-cancer chemotherapeutic drugs.

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