BioQuakes

AP Biology class blog for discussing current research in Biology

Tag: epigenetic

The journey to find a cure for cancer

What exactly does ‘epigenetic’ mean? Well epigenetic literally means “in addition to changes in genetic sequence.” The term now means any procedure to change genetic activity without changing the sequence of the actual DNA. So why is this important? Epigenetics can affect a lot of scientific research. For example DNA methylation is a hugely important epigenetic modification.

DNA methylation is where a methyl group would be added to a cytosine in a DNA sequence changing its function. This can be used in embryonic development, X-chromosome inactivation, genomic imprinting, gene suppression, carcinogenesis and chromosome stability. This means DNA methylation is very vital to growth and development- as it is a natural process- however can affect bad cells.

Examples of this are with cancer cells. DNA Methylation patterns- adding a group- are interrupted and changed when cancer is present. DNA methylation done on the promoters in tumor cells can turn off the expression of genes. In humans this can cause disruption of vital developmental pathways. This was then tested in an experiment (for now we will only observe human results because it was tested on mice as well) They tested human normal brain tissue vs. cancerous.

After testing the DNA methylation patterns on tumors, they found that 121 loci (loci is the central “hot spot” of genes) had strong methylation compared to the normal brain tissue which had 60% less. So what does all this mean??

Basically DNA methylation is a good thing in a normal environment. When cancer is present DNA methylation can change and be harmful in a negative environment such as a tumor because it causes hypermethylation.

While the take away is essentially the obvious- cancer is bad- scientists can use this data to find a correct cure for cancer and to create better medicine as some can harm even more by increasing DNA methylation in tumors. For more information on this click here.

 

 

 

Blame your Parents for your Stress?

Epigenetics is the study of inheritable changes in gene expression not directly coded in our DNA. Scientists at Tel Aviv University have shown that stress, induced by traumatic events, can be passed on to offspring. The study refers to this stress as passing on “memories.” The study finds the exact way that the inheritance of environmental influences is turned “on” and “off.” RNA sequences that regulate gene expression are partially responsible for deciding when the inheritance is on or off.

Scientists found that C.elegans worms only passed on inheritable epigenetic responses for a few generations (using small RNAs that target green fluorescent protein). This led them to believe that epigenetic responses die out eventually. However, this did not account for the possibility that inheritance could be regulated.  Scientists discovered that in order to create new small RNAs that allow a response to be passed on to multiple generations, they needed RdRP enzymes. These amplify heritable RNAs for generations. Certain genes that they called “MOTEK” (Modified Transgenerational Epigenetic Kinetics) were involved in turning on and off epigenetic transmissions. They switched on and off the small RNAs that the worms use to regulate genes using a feedback interaction between gene-regulating small RNAs and MOTEK. This determines whether an epigenetic memory will be passed on, and for how many generations.

Even though this study was done on worms, these scientists have said that these basics can possibly lead to discovery of inheritance for all organisms. This small bit of research can lead to endless amounts of knowledge for similar mechanisms in humans.

Overview of Epigenetics:

https://commons.wikimedia.org/wiki/File:Epigenetic_mechanisms.jpg

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Disruption in Epigenetics Can Lead to Cancer

Epigenetics is the study of potentially inheritable gene expression that does not involve any changes to the underlying DNA sequence. Epigenetic change is natural and common, but can be brought on by changes in environment, age, lifestyle, etc. Epigenetic modifications are seen as cells terminally differentiate and end up as skin cells, brain cells, or even liver cells. Epigenetics is a constant battle between active and inactive genes. If one were to overtake the other, it would alter the equilibrium in a persons body, potentially causing cancer.

Scientists are now claiming that once they have a better understanding of epigenetics and the factors which cause the cancer, they will be able to design drugs to counter this loss of equilibrium. Recent data identified an epigenetic “writer” called methyltransferase EZH2. It’s been linked to several types of cancer including melanomas and lymphomas. They’ve also identified and epigenetic “eraser”, KDM3A, which takes on an oncogenetic role and activates tumor promoting genes in the body. Epigenomic changes also contribute to cancer’s ability to go undetected in the human immune system.

Using this information, researchers may have found the right pathway for drug targeting. Metabolites and epigenetics are tightly connected and rely on each other to stay in equilibrium. In addition, there is a strong cooperation of epigenetic factors with the transcriptional complex. Now, researchers are looking into finding a way to us this connection to suppress tumor causing epigentics, and amplify those that fight cancer.

Fabian V. Filipp, the author of the paper, states, “There is an intriguing crosstalk between metabolism and epigenetics… With both fields maturing, further synergy between epigenetic and metabolomics may deliver new therapeutic agents.”

This research is incredibly interesting because of its newness. Each day, new informatoin and research is being found in the field of epigenetics. What I would’ve liked to learn in this article is how they plan to use the metabolites to battle the cancerous cells, and in what way they would be administered. Each day we get closer to the answers. The new technology and knowledge of today may finally lead us to a cure or at least a way towards remission with certain types of cancer.

Image result for cancer epigenetics

Source article: https://www.sciencedaily.com/releases/2017/03/170324083018.htm

The Mystery of Epigenetics

Epigenetics, the process of altering what genes are activated in a certain DNA sequence, is in many ways, still a mystery to the scientific community. How it is done chemically, as well as what environmental factors cause it. New discoveries have been made, linking surprising regulation enzymes and cultural factors. Ultimately, no matter what causes this phenomenon, it is a key factor in the evolutionary development of many species, and the world as we know it.

Tryptase:

A new study has shown the role of the enzyme tryptase in epigenetic development. Tryptase works to cleave the tails of histones, which will stop some epigenetic changes, while cells that lack tryptase, begin to proliferate uncontrollably. Most importantly, this proliferation causes cells to lose their identity. With this discovery, we see that by introducing tryptase, we can influence epigenetic development in cells.

Culture:

Another recent study has shown that cultural and environmental factors can influence a genome rather than only genetic ancestry. By studying the genetic sequences of both Mexican and Puerto Rican children, researchers discovered that there were differences that couldn’t be accounted for by ancestry.   The rest may be an impact on genetic makeup by differences in experiences, practices, and culture distinct to the two ethnic subgroups.

Ultimately, epigenetics is a fascinating concept that is often influenced by factors we might not suspect.   As the scientific community continues to make discoveries, the epigenetic phenomenon continues to excite and inspire researchers.

Photo: https://www.sciencedaily.com/releases/2017/01/170110120638.htm

#EpigeneticInheritance

Professor Marcus Pembrey of the University College of London transcribes the complexity of epigenetics into an understandable definition, simply put as “a change in our genetic activity without changing our genetic code.” The study of “epigenetic/transgenerational inheritance” has been a field of increasing popularity within the last decade, as studies and further research are beginning to show evidence of lifestyle stresses carrying over in the genome of each generation. Now, this is not to say that our grandparents way of living changed our DNA coding but rather potentially altered the way certain genetic information is or is not expressed.

 

To further explore the possibility of epigenetic inheritance, a laboratory in Boston conducted an experiment on three generations of mice.  A pregnant mouse was ill-fed in the late stages of pregnancy and as expected the offspring were born relatively small and later in life developed diabetes. However, the F2 generation experienced a high risk of acquiring diabetes, despite being well nourished. Another study on mice showed similar results; after a father was artificially taught to fear a particular smell, the offspring of that mouse also demonstrated a fear to the same smell.

 

Although the excitement over the groundbreaking research of epigenetics seems promising, researchers are still working to compile a stronger foundation of evidence to prove that this phenomena actually occurs in mammals. Professor Azim Surani of the University of Cambridge fully supports the idea of epigenetic inheritance in plants and worms, but has yet to commit to the same notion in mammals, as their biological processes differ greatly.

 

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