In September 2015, Monica was diagnosed with mid-stage breast cancer. Monica was an identical twin and her 38-year-old sister Erika also had regular mammograms and ultrasounds without ever finding cancer. A tumor the size of a tennis ball had grown in Monica’s left breast, and the cancer cells had spread to her lymph nodes.
These twins have the same genes, so why did one get cancer and the other not?
We have always thought that it is the genes, our DNA, that determine everything about us. In fact, there is another crucial factor: the “switch” of the genes. To put it this way, a gene determines that two twins wear the same necklace, but the gene’s “switch” determines whether they wear it or not, when they wear it, and how long they wear it.
The key to determining whether this gene is switched “on” or “off” is the epigenetic factor.
Each person’s DNA is fixed. The DNA is determined at the moment when the father’s sperm fuses with the mother’s egg. There are about 200 types of cells in the body, but they share the same DNA.
However, the same DNA creates different types of cells through the guidance of epigenetic factors, and the differences between these cells are enormous.
Epigenetic factors can also promote the development or non-development of cancer cells.
There are about 50 trillion cells in the human body, and each cell contains about 6 feet of DNA. The reason genes fit so long in a cell’s nucleus is because of the way the DNA is packaged.
The coils that DNA is wrapped around are called histones. A piece of DNA must be wound around 30 million of these coils. In the diagram, each of the circular coils represents a histone, and the threads wrapped around it are DNA.
Epigenetic factors can bind to the “tails” of histones or to DNA. They are attached to histones or DNA like tags.
Epigenetic factors (methyl groups) that bind to DNA can directly “turn off” genes.
Epigenetic factors also control the state of DNA entanglement on histones. It can cause genes to wrap tightly around histones in a compressed state. At this point, gene expression is suppressed and the body cannot read those genes. The genes are in the “off” state.
They can also loosen the DNA strands wrapped around the histones. The dissolved DNA is no longer suppressed so that the body can then read this DNA information. This means that the genes are in an “on” state.
Changes in epigenetic factors can ultimately determine whether or not a person suffers from a particular disease. For example, if an epigenetic factor is switched off, the gene for a protein that inhibits cancer cannot be expressed, so that protein is no longer produced, and a tumor forms. However, if the gene is left switched on, it can prevent the tumor from occurring.
Turn on good genes and turn off bad ones to avoid cancer and genetic diseases
We cannot change our genes. So how do we turn on the good genes and turn off the bad ones to prevent cancer from developing?
Diet, alcohol, tobacco and drug use, psychological stress and living environment all have an impact on epigenetic factors. They affect genes in two ways: DNA methylation and histone modification.
A growing number of studies have found that diet is a key to controlling gene expression.
A methyl group is an epigenetic factor that can get into cells through food, and when it’s tagged on DNA it’s called DNA methylation.
Methyl groups can turn off genes. In normal cells, oncogenes are switched off by the methyl groups and remain silent; Cancer suppressor genes aren’t methylated, so they’re turned on. The opposite is true for cancer cells.
Another approach, histone modification, has a similar rationale.
In short, when foods beneficial in fighting cancer are consumed, their ultimate goal is the same regardless of how they affect genes: turn off oncogenes and turn on cancer suppressor genes.
Nutrients and foods that alter gene expression to fight cancer
Polyphenols are found in fruits and vegetables and protect the body from disease. Dietary polyphenols alter the epigenetic factors of cancer cells, including by activating silent genes, and thus fight cancer.
Catechins are tea polyphenols, which are the most abundant bioactive compounds in green tea, accounting for more than 50 percent of its active compounds, and their anticancer effects have been widely studied.
Catechins can prevent methylation of cancer suppressor genes. Once these genes are highly methylated, they become inactive and can no longer act as anticancer agents. Catechin intake protects the activity of beneficial genes and prompts cells to produce anticancer proteins to help fight and treat cancer.
A study by researchers at the University of New Jersey was published in Cancer Research. Green tea catechins have been shown to inhibit DNA methylation and can reactivate cancer suppressor genes that have been silenced by high methylation in colon, skin, esophageal, and prostate cancer cells.
Another study published in the journal Carcinogenesis showed that catechins had the same modulating effect on DNA methylation in skin cancer cells.
In addition, a large number of studies have shown that taking catechin has a significant inhibitory effect on cancer cells in the oral cavity, breast, stomach, ovaries and pancreas.
Resveratrol is a plant polyphenol naturally found in grape skins. Fruits such as mulberries, cranberries, blueberries and peanuts also contain resveratrol.
Resveratrol has antioxidant, anti-inflammatory and anti-cancer properties and affects signaling pathways that control cell division, growth and apoptosis, and metastasis of cancer cells. Resveratrol’s antiproliferative properties have been demonstrated in liver, skin, breast, prostate, lung and colon cancer cells.
University of Arizona researchers found that resveratrol prevented epigenetic silencing of cancer suppressor proteins in breast cancer cells.
Scientists at the National Institutes of Health have shown that resveratrol can inhibit the expression of anti-apoptotic proteins in breast cancer cells, thereby inducing apoptosis, or cancer cell death. Hence, these researchers concluded that resveratrol is an excellent choice for targeted therapy for breast cancer.
Many people are familiar with soy isoflavones found in soybeans and soy products, which are one type of isoflavones. Isoflavones are also found in foods like broad beans and the root of the kudzu vine.
Soy isoflavones are a type of phytoestrogen. Its anti-cancer and anti-cancer properties are reflected in its effects on histone modification and DNA methylation, which regulates the ability for gene transcription.
Studies have shown that soy isoflavones can reactivate the expression of cancer suppressor genes in prostate cancer cells. It has also been found that soy isoflavones and other isoflavones can regulate the expression of non-coding RNAs in several types of cancer cells.
University of Missouri researchers conducted a human anti-cancer study of soy isoflavones. Thirty-four healthy premenopausal women were given 40 mg or 140 mg of isoflavones daily during one menstrual cycle, and the researchers then assessed the genetic changes in these individuals. The results showed that isoflavones ingestion caused hypermethylation of two breast cancer-related genes, silencing those breast cancer genes.
Isothiocyanate is a dietary compound found in cruciferous vegetables (including broccoli, collards, kale, and collards). It inhibits the growth of cancer cells and shows the ability to promote apoptosis of cancer cells.
In a human study conducted at Oregon State University, consumption of 68g of broccoli sprouts was shown to inhibit histone deacetylase activity in peripheral blood mononuclear cells, thereby achieving cancer prevention. In addition, researchers at another university in the United States have shown through cell culture experiments that isothiocyanates can inhibit methyltransferases in breast cancer cells and suppress the hTERT gene, which is overexpressed in about 90 percent of cancers.
In addition, there are several nutrients that can control and treat cancer. A review in the journal Epigenomics concluded that the following nutrients and foods can alter epigenetic factors in two ways.
Foods that fight cancer by regulating DNA methylation: Selenium (Brazil nuts), isothiocyanates (broccoli), catechins (green tea), resveratrol (grapes) and isoflavones (soybeans).
Foods that fight cancer by modulating histone modification: Isoflavones (soybeans), curcumin (curry), catechins (green tea), resveratrol (grapes), isothiocyanates (broccoli), selenium (Brazil nuts), and allyl mercaptan (garlic).