The latest authoritative paper in Nature: Drinking or inducing cancer is more dangerous for Chinese
Every January, the British people will make a new plan for the New Year. Drinking less often appears on the list. In fact, in China, a country with a profound wine culture, it is often possible to hear the sound of drinking less.
This is because the social culture of millions of people from the UK to China and the world has been deeply rooted in the hearts of the people, but it is not good for our health.
Alcohol can damage the liver, cause pancreatitis, and increase the risk of causing seven different types of cancer.
But it is not clear how alcohol causes cancer.
We have already learned some theories. For example, on December 6, 2017, a study published by Zdenek Skrott et al. pointed out that the alcohol-supply drug disulfiram can fight cancer, but the anti-cancer effect needs further verification. And now, on January 3, 2018, a new paper published in Nature, shows that acetaldehyde, a metabolite of alcohol, causes a large number of hematopoietic stem cell mutations. In mice exposed to ALDH2 gene deficiency, the number of DNA mutations was four times that of the control group.
We have taken another step in the secret of alcohol and cancer.
Focus on stem cells
When we talk about alcohol increasing the risk of cancer, there is one more important than this. This is because, as the latest research emphasizes, alcohol is broken down into one of these chemicals, which seems to be one of the culprit.
Alcohol is broken down into energy through a rigorous process decomposition. This is acetaldehyde, located in the center of the chain, which is the weakest link. If acetaldehyde does not decompose further, it will accumulate in the cells, which can cause cancer.
Alcohol can cause oral cancer, upper laryngeal cancer, laryngeal cancer, esophageal cancer, breast cancer, liver cancer, and intestinal cancer
Professor Ketan Patel and his team of scientists (funded by the British Cancer Institute) conducted a study at the MRC Laboratory of Molecular Biology at the University of Cambridge, England, and they have now discovered the damage of DNA by acetaldehyde - this is intracellular Life blueprint. In doing so, they have shown how cells can prevent this damage and how it can be repaired if it occurs.
Their work is focused on stem cells, which provide many different special cells for our bodies. It is important to understand how the DNA code of stem cells is destroyed, as this damage can lead to different types of cancer.
Specifically, the team studied blood stem cells in mice because, as Patel explained: "This is a good way to monitor DNA changes and damage, and is more valuable than looking at cells in a culture dish."
The team studied these stem cells to see if external factors such as alcohol can damage DNA and increase cancer risk.
Another reason is that their attention to stem cells is also important. In recent years, it has been speculated that this is the division of stem cells and the production of new cells, increasing the risk of different cancers in different parts of the body.
We have no control over this process. But research on this idea has sparked headlines around the world, saying that cancer is just "bad luck" (it's much more complicated than this), and there is no way to reduce the risk of different types of cancer (and indeed).
Patel said he and his team wanted to "see if this is true."
"The results are significant"
Scientists already know that cells can protect their DNA from acetaldehyde by using a group of enzymes called aldehyde dehydrogenase (ALDH).
Patel said: "When they work properly, ALDH enzymes prevent the formation of acetaldehyde by converting acetaldehyde to acetic acid, which can be used as an energy source."
To see how acetaldehyde may cause damage to stem cell DNA, Patel and his team had to study cells that did not have these enzymes.
To this end, they use laboratory-based genetic engineering techniques to make mice with blood stem cells that do not produce ALDH2 enzymes, which means they cannot break down acetaldehyde.
Then, they gave these mice diluted ethanol, which is the purest form of alcohol, and uses technology to observe the DNA inside the cell and read its code.
According to Patel, the results are striking and significant.
They found that in bone marrow samples carrying blood cells lacking ALDH2 enzyme, only one dose of ethanol caused an increase in acetaldehyde concentration, which severely damaged DNA.
"We found a lot of DNA damage in these cells. The DNA fragments were deleted, the fragments were destroyed, and we even saw some of the chromosomes being moved and rearranged," he said.
In fact, the researchers found that mice lacking the ALDH2 enzyme had four times more DNA damage in their blood cells than mice with fully normal ALDH2 enzymes.
To see if this damage occurred in rare stem cells that are rare in the bone marrow, Patel's team read the complete DNA code from carefully extracted stem cells. It carries a clear indication that DNA is broken down into two by acetaldehyde. This pattern of DNA damage has the potential to cause cancer cells.
Patel said: "Our research clearly shows that external factors such as drinking alcohol can damage DNA in blood stem cells, which means it can also destroy DNA in other types of stem cells."
"Although we did not see whether these mice have cancer, previous studies have shown that the type of DNA damage we see in these mice greatly increases the risk of cancer.
a two-layer system
Patel's team then turned their attention to understanding how cells try to repair the damage caused by acetaldehyde.
Through a series of experiments, including more laboratory-based genetic engineering, they found that cells take a coordinated approach to repairing their DNA.
“There are many ways in which cells can repair DNA damage,†Patel said. “We have shown that when alcohol breaks down to cause damage, the best way to fix it is to have a hierarchy.â€
The team found that the main route of acetaldehyde-related damage is through the Fanconi anemia repair pathway.
But some people have defects in the molecules that make these repairs, which means their cells need to use other cells.
Patel's team found that there are two other ways to repair blood stem cells that can repair alcohol-induced DNA damage (non-homologous end-repair pathways and homologous recombination pathways).
Patel described this as a "two-tier system."
"The first line of defense is the ALDH enzyme. However, if there is a defect or a deficiency, the stem cells will coordinate the use of different repair pathways to repair any damage caused by acetaldehyde and prevent it from being delivered to the cells they produce."
Chinese people are more dangerous?
By demonstrating that alcohol can destroy DNA in stem cells, this study reveals how it causes cancer.
This confirms that stem cells may be damaged by external factors - it's not just bad luck.
What it can't do is change the key message of alcohol and cancer: the less alcohol you drink, the lower the risk of cancer.
Li Hui's research group of Fudan University found that there are 7 variants of alcohol dehydrogenase, of which type 7 increases the rate of degradation of alcohol to acetaldehyde by 13 times.
This gene was originally unique to the Chinese, and later spread to East Asia such as Japan and South Korea. In China, 70% of Han people have this gene.
At the same time, studies have shown that nearly half of people in China lack aldehyde dehydrogenase (ALDH2). Chen Zhehong, a senior researcher at Stanford University School of Medicine in the United States, said that in the case of the Taiwanese population survey, the ALDH2 gene deletion rate is about 47%, ranking first in the world.
This means that the acetaldehyde produced by the degradation of type 7 alcohol dehydrogenase is likely to accumulate in the human body for a short period of time, and it will not be degraded in time, causing harm to the human body.
Laboratory Glassware,Lab Glassware,Chemistry Glassware,Microscope Slides And Cover Slips
Yancheng Rongtai Labware Co.,Ltd , https://www.rongtailab.com