90 research outputs found
Association of facial ageing with DNA methylation and epigenetic age predictions
Data from the Lothian Birth Cohort 1921 (LBC1921). (DOCX 13 kb
Microvessel density as new prognostic marker after radiotherapy in rectal cancer
<p>Abstract</p> <p>Background</p> <p>The extent of angiogenesis is an important prognostic factor for colorectal carcinoma, however, there are few studies concerning changes in angiogenesis with radiotherapy (RTX). Our aim was to investigate changes in tumor angiogenesis influenced by radiotherapy to assess the prognostic value of angiogenesis the microvessel density (MVD) in overall survival after radiotherapy.</p> <p>Methods</p> <p>Tumor specimens were taken from 101 patients resected for rectal cancer. The patients were divided into three groups according to the treatment they received before surgery (not treated, a short course, or long course of RTX). Tumor specimens were paraffin-embedded and immunohistochemistry was performed with primary antibody against CD-34 to count MVD.</p> <p>Results</p> <p>MVD was significantly lower in the group of patients treated with a long course of RTX (p <0.025). The mean MVD for the long RTX group was 134.8; for the short RTX group – 192.5; and for those not treated with RTX – 193.0. There were no significant statistical correlations between MVD and age, sex, grade of tumor differentiation (G) and tumor size (T) in those untreated with RTX. In long RTX group we found a significant prognostic rate for MVD when the density cut off was near 130 with 92.3% sensitivity and 64.7% specificity. When the MVD was lower than a cut off of 130, the survival period significantly increased (p = 0.001), the mortality rate is significantly higher if the MVD is higher than 130 (microvessel/mm<sup>2</sup>) (1953.047; p = 0.002), if the histological grade is moderate/poor (127.407; p = 0.013), if the tumor is T3/T4 (111.618; p = 0.014), and if the patient is male (17.92; p = 0.034) adjusted by other variable in model.</p> <p>Conclusion</p> <p>Our results show that a long course of radiotherapy significantly decreased angiogenesis in rectal cancer tissue. MVD was found to be a favourable marker for tumor behaviour during RTX and a predictor of overall survival after long course of RTX. Further investigations are now needed to determine the changes in angiogenesis during a shorter course of RTX.</p
Longitudinal study of DNA methylation during the first 5 years of life.
Background: Early life epigenetic programming influences adult health outcomes. Moreover, DNA methylation levels have been found to change more rapidly during the first years of life. Our aim was the identification and characterization of the CpG sites that are modified with time during the first years of life. We hypothesize that these DNA methylation changes would lead to the detection of genes that might be epigenetically modulated by environmental factors during early childhood and which, if disturbed, might contribute to susceptibility to diseases later in life. Methods: The study of the DNA methylation pattern of 485577 CpG sites was performed on 30 blood samples from 15 subjects, collected both at birth and at 5 years old, using Illumina® Infinium 450 k array. To identify differentially methylated CpG (dmCpG) sites, the methylation status of each probe was examined using linear models and the Empirical Bayes Moderated t test implemented in the limma package of R/Bioconductor. Surogate variable analysis was used to account for batch effects. Results: DNA methylation levels significantly changed from birth to 5 years of age in 6641 CpG sites. Of these, 36.79 % were hypermethylated and were associated with genes related mainly to developmental ontology terms, while 63.21 % were hypomethylated probes and associated with genes related to immune function. Conclusions: Our results suggest that DNA methylation alterations with age during the first years of life might play a significant role in development and the regulation of leukocyte-specific functions. This supports the idea that blood leukocytes experience genome remodeling related to their interaction with environmental factors, underlining the importance of environmental exposures during the first years of life and suggesting that new strategies should be take into consideration for disease prevention
Inhibitory effect of ginsenoside Rg3 combined with gemcitabine on angiogenesis and growth of lung cancer in mice
<p>Abstract</p> <p>Background</p> <p>Ginsenoside Rg3, a saponin extracted from ginseng, inhibits angiogenesis. The combination of low-dose chemotherapy and anti-angiogenic inhibitors suppresses growth of experimental tumors more effectively than conventional therapy or anti-angiogenic agent alone. The present study was designed to evaluate the efficacy of low-dose gemcitabine combined with ginsenoside Rg3 on angiogenesis and growth of established Lewis lung carcinoma in mice.</p> <p>Methods</p> <p>C57L/6 mice implanted with Lewis lung carcinoma were randomized into the control, ginsenoside Rg3, gemcitabine and combination group. The quality of life and survival of mice were recorded. Tumor volume, inhibitive rate and necrosis rate were estimated. Necrosis of tumor and signals of blood flow as well as dynamic parameters of arterial blood flow in tumors such as peak systolic velocity (PSV) and resistive index (RI) were detected by color Doppler ultrasound. In addition, expression of vascular endothelial cell growth factor (VEGF) and CD31 were observed by immunohistochemstry, and microvessel density (MVD) of the tumor tissues was assessed by CD31 immunohistochemical analysis.</p> <p>Results</p> <p>Quality of life of mice in the ginsenoside Rg3 and combination group were better than in the control and gemcitabine group. Combined therapy with ginsenoside Rg3 and gemcitabine not only enhanced efficacy on suppression of tumor growth and prolongation of the survival, but also increased necrosis rate of tumor significantly. In addition, the combination treatment could obviously decrease VEGF expression and MVD as well as signals of blood flow and PSV in tumors.</p> <p>Conclusion</p> <p>Ginsenoside Rg3 combined with gemcitabine may significantly inhibit angiogenesis and growth of lung cancer and improve survival and quality of life of tumor-bearing mice. The combination of chemotherapy and anti-angiogenic drugs may be an innovative and promising therapeutic strategy in the experimental treatment of human lung cancer.</p
Genome-wide DNA methylation analysis in blood cells from patients with Werner syndrome
Werner syndrome is a progeroid disorder characterized by premature age-related phenotypes. Although it is well established that autosomal recessive mutations in the WRN gene is responsible for Werner syndrome, the molecular alterations that lead to disease phenotype remain still unidentified
Aberrant crossed corticospinal facilitation in muscles distant from a spinal cord injury.
Crossed facilitatory interactions in the corticospinal pathway are impaired in humans with chronic incomplete spinal cord injury (SCI). The extent to which crossed facilitation is affected in muscles above and below the injury remains unknown. To address this question we tested 51 patients with neurological injuries between C2-T12 and 17 age-matched healthy controls. Using transcranial magnetic stimulation we elicited motor evoked potentials (MEPs) in the resting first dorsal interosseous, biceps brachii, and tibialis anterior muscles when the contralateral side remained at rest or performed 70% of maximal voluntary contraction (MVC) into index finger abduction, elbow flexion, and ankle dorsiflexion, respectively. By testing MEPs in muscles with motoneurons located at different spinal cord segments we were able to relate the neurological level of injury to be above, at, or below the location of the motoneurons of the muscle tested. We demonstrate that in patients the size of MEPs was increased to a similar extent as in controls in muscles above the injury during 70% of MVC compared to rest. MEPs remained unchanged in muscles at and within 5 segments below the injury during 70% of MVC compared to rest. However, in muscles beyond 5 segments below the injury the size of MEPs increased similar to controls and was aberrantly high, 2-fold above controls, in muscles distant (>15 segments) from the injury. These aberrantly large MEPs were accompanied by larger F-wave amplitudes compared to controls. Thus, our findings support the view that corticospinal degeneration does not spread rostral to the lesion, and highlights the potential of caudal regions distant from an injury to facilitate residual corticospinal output after SCI
DNA methylation levels in candidate genes associated with chronological age in mammals are not conserved in a long-lived seabird
© 2017 De Paoli-Iseppi et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Most seabirds do not have any outward identifiers of their chronological age, so estimation of seabird population age structure generally requires expensive, long-term banding studies. We investigated the potential to use a molecular age biomarker to estimate age in short-tailed shearwaters (Ardenna tenuirostris). We quantified DNA methylation in several A. tenuirostris genes that have shown age-related methylation changes in mammals. In birds ranging from chicks to 21 years of age, bisulphite treated blood and feather DNA was sequenced and methylation levels analysed in 67 CpG sites in 13 target gene regions. From blood samples, five of the top relationships with age were identified in KCNC3 loci (CpG66: R2 = 0.325, p = 0.019). In feather samples ELOVL2 (CpG42: R2 = 0.285, p = 0.00048) and EDARADD (CpG46: R2 = 0.168, p = 0.0067) were also weakly correlated with age. However, the majority of markers had no clear association with age (of 131 comparisons only 12 had a p-value < 0.05) and statistical analysis using a penalised lasso approach did not produce an accurate ageing model. Our data indicate that some age-related signatures identified in orthologous mammalian genes are not conserved in the long-lived short tailed shearwater. Alternative molecular approaches will be required to identify a reliable biomarker of chronological age in these seabirds
Age-associated DNA methylation changes in immune genes, histone modifiers and chromatin remodeling factors within 5 years after birth in human blood leukocytes
Soy isoflavones, estrogen therapy, and breast cancer risk: analysis and commentary
There has been considerable investigation of the potential for soyfoods to reduce risk of cancer, and in particular cancer of the breast. Most interest in this relationship is because soyfoods are essentially a unique dietary source of isoflavones, compounds which bind to estrogen receptors and exhibit weak estrogen-like effects under certain experimental conditions. In recent years the relationship between soyfoods and breast cancer has become controversial because of concerns – based mostly on in vitro and rodent data – that isoflavones may stimulate the growth of existing estrogen-sensitive breast tumors. This controversy carries considerable public health significance because of the increasing popularity of soyfoods and the commercial availability of isoflavone supplements. In this analysis and commentary we attempt to outline current concerns regarding the estrogen-like effects of isoflavones in the breast focusing primarily on the clinical trial data and place these concerns in the context of recent evidence regarding estrogen therapy use in postmenopausal women. Overall, there is little clinical evidence to suggest that isoflavones will increase breast cancer risk in healthy women or worsen the prognosis of breast cancer patients. Although relatively limited research has been conducted, and the clinical trials often involved small numbers of subjects, there is no evidence that isoflavone intake increases breast tissue density in pre- or postmenopausal women or increases breast cell proliferation in postmenopausal women with or without a history of breast cancer. The epidemiologic data are generally consistent with the clinical data, showing no indication of increased risk. Furthermore, these clinical and epidemiologic data are consistent with what appears to be a low overall breast cancer risk associated with pharmacologic unopposed estrogen exposure in postmenopausal women. While more research is required to definitively allay concerns, the existing data should provide some degree of assurance that isoflavone exposure at levels consistent with historical Asian soyfood intake does not result in adverse stimulatory effects on breast tissue
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