Inflammation is a multifaceted defense response of immune system against infection. Chronic inflammation has been implicated as an imminent threat for major human malignancies and is directly linked to various steps involved in tumorigenesis. Inflammatory cytokines, interleukins, interferons, transforming growth factors, chemokines, and adhesion molecules have been associated with chronic inflammation. Numerous cytokines are reported to be aberrantly regulated by different epigenetic mechanisms like DNA methylation and histone modifications in tumor tissues, contributing to pathogenesis of tumor in multiple ways. Some of these cytokines also work as epigenetic regulators of other crucial genes in tumor biology, either directly or indirectly. Such regulations are reported in lung, breast, cervical, gastric, colorectal, pancreatic, prostate, and head and neck cancers. Epigenetics of inflammatory mediators in cancer is currently subject of extensive research. These investigations may help in understanding cancer biology and to develop effective therapeutic strategies. The purpose of this paper is to have a brief view of the aberrant regulation of inflammatory cytokines in human malignancies.
2 April 2018 in Applied Biochemistry and Biotechnology
Since the domestication of crop species, humans have derived specific varieties for particular uses and shaped the genetic diversity of these varieties. Here, using an interdisciplinary approach combining ethnobotany and population genetics, we document the within‐variety genetic structure of a population‐variety of bread wheat (Triticum aestivum L.) in relation to farmers’ practices to decipher their contribution to crop species evolution. Using 19 microsatellites markers, we conducted two complementary graph theory‐based methods to analyze population structure and gene flow among 19 sub‐populations of a single population‐variety [Rouge de Bordeaux (RDB)]. The ethnobotany approach allowed us to determine the RDB history including diffusion and reproduction events. We found that the complex genetic structure among the RDB sub‐populations is highly consistent with the structure of the seed diffusion and reproduction network drawn based on the ethnobotanical study. This structure highlighted the key role of the farmer‐led seed diffusion through founder effects, selection and genetic drift because of human practices. An important result is that the genetic diversity conserved on farm is complementary to that found in the genebank indicating that both systems are required for a more efficient crop diversity conservation.
Background: Certain temperate species require prolonged exposure to low temperature to initiate transition from vegetative growth to flowering, a process known as vernalization. In wheat, winter cultivars require vernalization to initiate flowering, making vernalization requirement a trait of key importance in wheat agronomy. The genetic bases of vernalization response have been largely studied in wheat, leading to the characterization of a regulation pathway that involves the key gene VERNALIZATION1 (VRN1). While previous studies in wheat and barley have revealed the functional role of histone modification in setting VRN1 expression, other mechanisms might also be involved. Here, we were interested in determining whether the cold-induced expression of the wheat VRN-A1 gene is associated with a change in DNA methylation. Results: We provide the first DNA methylation analysis of the VRN-A1 gene, and describe the existence of methylation at CG but also at non CG sites. While CG sites show a bell-shape profile typical of gene-body methylation, non CG methylation is restricted to the large (8.5 kb) intron 1, in a region harboring fragments of transposable elements (TEs). Interestingly, cold induces a site-specific hypermethylation at these non CG sites. This increase in DNA methylation is transmitted through mitosis, and is reset to its original level after sexual reproduction. Conclusions: These results demonstrate that VRN-A1 has a particular DNA methylation pattern, exhibiting rapid shift within the life cycle of a winter wheat plant following exposure to particular environmental conditions. The finding that this shift occurs at non CG sites in a TE-rich region opens interesting questions onto the possible consequences of this type of methylation in gene expression.
Malathion, a well-known organophosphate pesticide, has been used in agriculture over the last two decades for controlling pests of economically important crops. In the present study, a single bacterium, ML-1, was isolated by soil-enrichment technique and identified as Bacillus licheniformis on the basis of the 16S rRNA technique. The bacterium was grown in carbon-free minimal salt medium (MSM) and was found to be very efficient in utilizing malathion as the sole source of carbon. Biodegradation experiments were performed in MSM without carbon source to determine the malathion degradation by the selected strain, and the residues of malathion were determined quantitatively using HPLC techniques. Bacillus licheniformis showed very promising results and efficiently consumed malathion as the sole carbon source via malathion carboxylesterase (MCE), and about 78% malathion was degraded within 5 days. The carboxylesterase activity was determined by using crude extract while using malathion as substrate, and the residues were determined by HPLC. It has been found that the MCE hydrolyzed 87% malathion within 96 h of incubation. Characterization of crude MCE revealed that the enzyme is robust in nature in terms of organic solvents, as it was found to be stable in various concentrations of ethanol and acetonitrile. Similarly, and it can work in a wide pH and temperature range. The results of this study highlighted the potential of Bacillus licheniformis strain ML-1 as a biodegrader that can be used for the bioremediation of malathion-contaminated soil.
The persistent nature of lead (Pb) and cadmium (Cd) in the environment severely affects plant growth and yield. Conversely, plants acquire zinc (Zn) from the soil for their vital physiological and biochemical functions. However, the interplay and coordination between essential and toxic metals for their uptake and translocation and the putative underlying epigenetic mechanisms have not yet been investigated in maize. Here, we report that the presence of Zn facilitates the accumulation and transport of Pb and Cd in the aerial parts of the maize plants. Moreover, the Zn, Pb, and Cd interplay specifically interferes with the uptake and translocation of other divalent metals, such as calcium and magnesium. Zn, Pb, and Cd, individually and in combinations, differentially regulate the expression of DNA methyltransferases, thus alter the DNA methylation levels at the promoter of Zinc-regulated transporters, Iron-regulated transporter-like Protein (ZIP) genes to regulate their expression. Furthermore, the expression of histone deacetylases (HDACs) varies greatly in response to individual and combined metals, and HDACs expression showed a negative correlation with ZIP transporters. Our study highlights the implication of DNA methylation and histone acetylation in regulating the metal stress tolerance dynamics through Zn transporters and warns against the excessive use of Zn fertilizers in metal contaminated soils.