Subscribe to the BioNews newsletter for free

Login
Advanced Search

Search for
BioNews

Like the Progress Educational Trust on Facebook


The Fertility Show


 

Event Review: Masterpieces of Epigenetics - The Missing Link between Nature and Nurture

14 January 2013

By James Lush

Policy Officer, Biochemical Society

Appeared in BioNews 688

Masterpieces of Epigenetics: The Missing Link between Nature and Nurture

Presented by Dr Nessa Carey

Organised by the Biochemical Society and the University of Leeds

Conference Auditorium, University of Leeds, Leeds LS2 9JT, UK

Tuesday 11 December 2012

'Masterpieces of Epigenetics: The Missing Link between Nature and Nurture', organised by the Biochemical Society and the University of Leeds, Tuesday 11 December 2012


'Beautiful science' was how Dr Nessa Carey described epigenetics at the Biochemical Society Annual Symposium Public Lecture, held at the University of Leeds on 11 December. Dr Carey, who works at Pfizer, explained that while the DNA double helix remains one of the most iconic images of biology, we are only now beginning to gain a clearer picture of how specialised cells 'wriggle in the troughs of specialisation'; retaining their functions but also responding to the environment.

In 2000, US President Bill Clinton proclaimed that 'Today we are learning the language in which God created life', following an announcement about progress on the Human Genome Project. Dr Carey explained that it can take just one problem with any of the three billion nucleotide pairs that make up our DNA for us to have a debilitating disease. Would knowing the human genome sequence allow us to combat such diseases? Unfortunately for this theory, genotype does not always equate to phenotype. DNA, Dr Carey used the analogy, is a script, not a template.

Dr Carey gave several examples of so-called 'intangible variation'. Identical mice kept under standardised conditions will not be identical. A maggot and a fly must use the same genetic script. In some crocodiles, you cannot tell from the DNA whether individuals are male or female. Where genetic identity does not equal phenotypic identity, epigenetics is at play, and we are 'masterpieces of epigenetics', she explained. Up until now we have only been able to describe these phenomena. Now we are starting to understand how they actually happen.

The modification of histones (proteins around which DNA winds to be compacted into cells) and the methylation (the binding of methyl chemical groups) of DNA are two important epigenetic mechanisms, we heard. For example, the brain does not produce haemoglobin because the high levels of methylation around the genes that code for this become completely inaccessible to the protein-producing machinery of the cell. Dr Carey explained that there are around 70 known types of histone modification, which all have subtle effects on the accessibility of genes. Through all this, the genome itself remains unchanged.

Epigenetics is starting to become a fertile area for designing new drugs. 'Why else would Pfizer be interested in this area', noted Dr Carey. Using the analogy of a bicycle being chained up without you holding the key, she explained that in many chronic conditions there is nothing wrong with the genes, but they are locked into inappropriate patterns of expression.

Cancer is a particularly fruitful field for this kind of research, we heard. Zolinza affects proteins which contribute to the modification of histones, for the treatment of cutaneous T Cell lymphoma. Vidaza interferes with the DNA methylation process and ribosome function for the treatment of myelodysplastic syndrome.

It is a well-known phenomenon that having a stressful childhood can have a significant impact on adulthood, even when the child is moved to a nurturing environment following an initial period of maltreatment. The traditional explanation for this is 'psychological damage'. This is a return to us describing, rather than explaining the issue. Dr Carey encouraged us to question what the true physical basis for this is. This phenomenon has been investigated in rats. Experiments have shown that rats who are nurtured through childhood shrug off minor stresses in adulthood. 'Unloved' rats, on the other hand, 'jump out of their skin'. Investigation demonstrates that this is because the 'fight or flight' response becomes over-activated.

What other diseases could this type of mechanism be applied to? Epigenetics can be implicated in chronic or persistent diseases which place a great burden on our society. For example, rheumatoid arthritis, post-traumatic stress disorder, diabetes and heart disease could all be treated before serious manifestation, Dr Carey convincingly suggested, if we had drugs to pre-emptively counter the epigenetic effects.

No drugs are free of side effects, and we are not able to pre-empt most disease cases to a significant degree of accuracy. So how could clinical trials be run for these scenarios? On an ethical level, would any eventual 'treatment' for childhood neglect distract from the search for sociological solutions? These are vitally important questions. When applied to treatment, who would we treat and when?

There are still many unanswered questions. The only part of the genome that gets more complicated in higher organisms is what was formerly known as 'junk DNA'. We now know that this actually provides the 'molecular velcro' to make things stick to histones, but we are nowhere near unlocking its power. In the mean time, we risk epigenetics becoming a catch-all phrase for everything we don't understand! This is a burgeoning field, which could lead to exciting but complex medical implications. But we need to play the long game and debate it appropriately.

SOURCES & REFERENCES

RELATED ARTICLES FROM THE BIONEWS ARCHIVE

27 February 2017 - by Annabel Slater 
'Introducing Epigenetics: A graphic guide' is a mini-textbook pitched as a non-fiction comic book. Despite the colourful cover and perky graphics inside, this book does not make for light reading...
21 December 2015 - by Isobel Steer 
If you'd like to learn more about epigenetics, or just watch a masterly science presenter at work, look to 2015 Francis Crick Prize winner Professor Rob Klose...
28 October 2013 - by Dr John Gillott 
Dominic Cummings and Robert Plomin are claiming a great deal about the effect of genetics on intelligence, some of which is sound, some of which is not and some of which is very speculative...
16 September 2013 - by Dr Linda Wijlaars 
It might seem a bit simplistic to start a review of a debate with the dictionary definition, but after watching Professor Tim Spector's and Dr Helena Cronin's debate on the new science of gender, I just had to go back and check....

10 September 2012 - by  
In her new book, 'The Epigenetics Revolution', Nessa Carey argues that we are in the midst of the next great upheaval in biological thinking...
08 May 2012 - by Sarah Norcross and Sandy Starr 
The conference 'Genomics in Society: Facts, Fictions and Cultures' marked the 10th anniversary of the Economic and Social Research Council's Genomics Network, and also the passing of nearly ten years since the completion of the Human Genome Project...
23 April 2012 - by Ruth Pidsley 
Epigenetics has become something of a hot topic in recent years throughout the scientific community. 'Epigenetics: Linking Genotype and Phenotype in Development and Evolution', edited by Professors Benedikt Hallgrímsson and Brian Hall, reminds a new generation of molecular and systems biologists about the historical roots and scope of epigenetics...
16 April 2012 - by Dr Rachael Panizzo 
Epigenetics is a complex subject, so explaining it in just two minutes is a big ask. But that's what the short video clip, 'Health explained: epigenetics', on the BBC website attempts to do. Aimed at a general audience, the video succeeds in giving us a very basic introduction, but doesn't manage to capture what is new and exciting about this field of research...
05 September 2011 - by Rosemary Paxman 
The immediate impact of environmental factors like diet, smoking and stress on health are well understood. But less is known about how your lifestyle can directly effect the health of your unborn children and grandchildren...

HAVE YOUR SAY
Be the first to have your say.

You need to or  to add comments.

By posting a comment you agree to abide by the BioNews terms and conditions


- click here to enquire about using this story.

Published by the Progress Educational Trust

CROSSING FRONTIERS

Moving the Boundaries of Human Reproduction

Public Conference
London
8 December 2017

Speakers include

Professor Azim Surani

Professor Magdalena Zernicka-Goetz

Professor Robin Lovell-Badge

Sally Cheshire

Professor Guido Pennings

Katherine Littler

Professor Allan Pacey

Dr Sue Avery

Professor Richard Anderson

Dr Elizabeth Garner

Dr Jacques Cohen

Dr Anna Smajdor

Dr Andy Greenfield

Vivienne Parry

Dr Helen O'Neill

Dr César Palacios-González

Philippa Taylor

Fiona Fox

Sarah Norcross


BOOK HERE

Good Fundraising Code

Become a Friend of PET HERE and give the Progress Educational Trust a regular donation