Tag Archives: ENVIRONMENT

‘Epigenetic’ Gene Tweaks Could Trigger Cancer

You could be forgiven for thinking of cancer as a genetic disease. Sure, we know it can be triggered by things you do – smoking being the classic example – but most of us probably assume that we get cancer because of a genetic mutation – a glitch in our DNA. It turns out that this is not quite the end of the story.

We now have the first direct evidence that switching off certain genes – something that can be caused by our lifestyle or the environment we live in – can trigger tumours, without mutating the DNA itself. The good news is that these changes are, in theory, reversible.

All cells contain the same DNA, but individual genes in any cell can be switched on or off by the addition or subtraction of a methyl group – a process known as epigenetic methylation.

For years, researchers have known that mutations to our DNA – either those passed on at birth or those acquired as a result of exposure to radiation, for example – can cause cancer. But epigenetic changes have also been implicated in cancer because abnormal patterns of gene methylation are seen in virtually all types of human tumours.

For example, a gene called MLH1 produces a protein that repairs DNA damage. It is often mutated in colon cancer tumours, but in some tumour samples the gene is healthy, but appears to have been silenced by methylationThe problem is that it has been difficult to test whether abnormal methylation occurs as a result of a tumour or is a cause of its growth.

In genetics you can easily delete a gene and see what the consequence is, but it’s much harder to direct methylation to specific regions of the genome,” says Lanlan Shen of Baylor College of Medicine in Houston, Texas.

To get round this problem, Shen and her colleagues used a naturally occurring sequence of DNA, which draws in methyl groups to methylate nearby genes. They call it their “methylation magnet”.

The team inserted this sequence next to the tumour suppressor gene, p16, in mouse embryonic stem cells. These embryos then developed into mice that carry the “methylation magnet” in all of their cells. The team focused on methylating p16 because it is abnormally methylated in numerous cancers.

They monitored the rodents for 18 months – until they reached the mouse equivalent of middle age. Over this time, 30 per cent of the mice developed tumours around their body, including in their liver, colon, lungs and spleen. None of a control group of genetically identical mice developed tumours.

Some tissues showed faster methylation than others, for example in the liver, colon and spleen, and that’s exactly where we saw the tumours grow,” says Shen. “It seems like methylation predisposed the tissue to tumour development.” She reckons that methylation silences p16, which lifts the break that it normally places on any abnormal cell division.

Source: https://www.newscientist.com/

How To ConVert Waste Heat Into Electricity

Thermoelectric materials, capable of transforming heat into electricity, are very promising when converting residual heat into electrical energy, since they allow us to utilize hardly usable or almost lost thermal energy in an efficient way. Researchers at the Institute of Materials Science of Barcelona (ICMAB-CSIC) have created a new thermoelectric material: a paper capable of converting waste heat into electricity. These devices could be used to generate electricity from residual heat to feed sensors in the field of the Internet of Things, Agriculture 4.0 or Industry 4.0.


This device is composed of cellulose, produced in situ in the laboratory by bacteria, with small amounts of a conductor nanomaterial, carbon nanotubes, using a sustainable and environmentally friendly strategy” explains Mariano Campoy-Quiles, researcher at the ICMAB.

“In the near future, they could be used as wearable devices, in medical or sports applications, for example. And if the efficiency of the device was even more optimized, this material could lead to intelligent thermal insulators or to hybrid photovoltaic-thermoelectric power generation systems” predicts Campoy-Quiles. In addition “due to the high flexibility of the cellulose and to the scalability of the process, these devices could be used in applications where the residual heat source has unusual forms or extensive areas, as they could be completely covered with this material” indicates Anna Roig, researcher at the ICMAB.

Since bacterial cellulose can be home made, perhaps we are facing the first step towards a new energy paradigm, where users will be able to make their own electric generators. We are still far away, but this study is a beginning. We have to start somewhere. “Instead of making a material for energy, we cultivate it” explains Mariano Campoy-Quiles, a researcher of this study. “Bacteria, dispersed in an aqueous culture medium containing sugars and carbon nanotubes, produce the nanocellulose fibers that will end up forming the device, in which the carbon nanotubes are embedded” continues Campoy-Quiles.”We obtain a mechanically resistant, flexible and deformable material, thanks to the cellulose fibers, and with a high electrical conductivity, thanks to the carbon nanotubes,” adds Anna Laromaine, researcher at the ICMAB. “The intention is to approach the concept of circular economy, using sustainable materials that are not toxic for the environment, which are used in small amounts, and which can be recycled and reused,“says Roig.

The study has been published in the Energy & Environmental Science journal.

Source: http://icmab.es/

 

Graphene’s Consequences On Human Health

As the drive to commercialise graphene continues, it is important that all safety aspects are thoroughly researched and understood. The Graphene Flagship project has a dedicated Work Package studying the impact of graphene and related materials on our health, as well as their environmental impact. This enables safety by design to become a core part of innovation.

Researches and companies are currently using a range of materials such as few layered graphene, graphene oxide and heterostructures. The first step to assess the toxicology is to fully characterise these materials. This work overviews the production and characterisation methods, and considers different materials, which biological effects depend on their inherent properties.


One of the key messages is that this family of materials has varying properties, thus displaying varying biological effects. It is important to emphasize the need not only for a systematic analysis of well-characterized graphene-based materials, but also the importance of using standardised in vitro or in vivo assays for the safety assessment,” says Bengt Fadeel, lead author of this paper working at Graphene Flagship partner Karolinska Institutet, Sweden.

This review correlates the physicochemical characteristics of graphene and related materials to the biological effects. A classification based on lateral dimensions, number of layers and carbon-to-oxygen ratio allows us to describe the parameters that can alter graphene’s toxicology. This can orient future development and use of these materials,” explains Alberto Bianco, from Graphene Flagship partner CNRS, France and deputy leader of the Graphene Flagship Work Package on Health and Environment.

Source: https://graphene-flagship.eu/