Epigenetics

1
2
3
4
5
6
7
8
9
The epigenome kicks in and the caterpillar beings the transformation.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
46
47
48
49
50
52
53
54
55
56
57
58
59
60
61
62
63
64
65

Epigenetics and Cancer – November 3, 2020
Buried within our DNA, there exists a vast amount of dormant genetic material – a remarkable percentage of which consists of ancient inserted elements that have found their way into our genome, only to be silenced for millions of years. 

While the origins of most of these obsolete retroelements are not fully known, their inactive status is epigenetically controlled. It has been suggested that “turning on” these parts of our genome could be useful, especially in fighting off certain diseases like cancer that notoriously outwit and overpower our immune system.

In a new study published in Nature, a team of scientists at the University of Toronto led by Dr. Daniel De Carvalho, Associate Professor, Medical Biophysics, has now identified the purpose of some of these genomic remnants, and what they have found could lead to a completely new field of cancer therapies.

Utilizing epigenetic drugs, the researchers activate these repressed retroelements to induce what is referred to as “viral mimicry”. This effect essentially prompts the cancer cells to behave like an infection, thereby signaling the immune system into an aggressive attack. Moreover, they have also discovered how to drive down any resistance to this assault by inhibiting an enzyme used by the cancer cells as a defense mechanism.

Dr. De Carvalho points out that over the course of evolution, the human genome has collected a series of silent repetitive elements. “It has been unclear why or what purpose they serve,” he says. “As’ genome archeologists,’ we set out to identify the function of these ‘DNA relics’ and have found that under the right conditions, they can be reactivated and stimulate our immune system.”

In a previous article, we have discussed how most of our DNA is made up of non-functioning parts that lay scattered along the genome and are suppressed via DNA methylation. We have also written several articles that show how viruses use epigenetics to evade the immune system and how epigenetic cancer therapies are becoming more mainstream.

Indeed, one of the most exciting and fastest-growing areas in clinical oncology involves investigating innovative epigenetic therapies that can potentially modify the immune system to combat tumor cell growth. Finding effective and safe treatment is especially important today since not all cancer patients respond well to current immunotherapy methods.

Unlike gene therapy, which works by altering the genetic code, epigenetic drugs modify only changes in gene expression. Epigenetic alterations occur naturally in cells as a result of factors such as aging, lifestyle experiences, and other environmental exposures. Because these occurrences are inherently reversible, therapies that can completely remove the modifications may allow cells to revert back to their original precancerous condition.