More explanation:
“But overall,” he said, “smoking is associated with loss of Y, and loss of Y is associated with cancer.”
Men have an X and a Y chromosome, while women have two X chromosomes.
And experts used to think that the Y — short and stumpy compared with the X — did little more than determine male sex and ensure normal’
“
The bottom two-thirds of the Y chromosome was seen as just repetitive DNA that doesn’t code for anything,” explained Dr. Martin Bialer, a medical geneticist at North Shore-LIJ Health System in Great Neck, N.Y.
“
But now we’re starting to think it may have more roles than just determining sex — though that’s a pretty important one,” said Bialer, who was not involved in the study.
Recent research has shown that the
Y chromosome actually contains a large number of genes. Their
jobs are not fully understood yet, but a
couple of those genes may help suppress tumors, according to Forsberg’s team.
It’s possible, Forsberg said, that the
immune system’s cancer “surveillance” is disrupted in cells that lack the Y chromosome.
But Bialer said that while that’s plausible, it’s also “a pretty big leap.” For one, he noted,
loss of the Y chromosome may just be a “marker” for other chromosome damage caused by smoking.
For the study, the researchers analyzed blood samples from more than 6,000 older men taking part in three separate studies. Overall, about
15 percent of men aged 70 and older had a significant loss of the Y chromosome (affecting at least
10 percent of their blood cells), according to the study.
But
current smokers were two to four times more likely to show loss of Y than non-smokers were, the investigators found.
The researchers also looked at some other potential risk factors for Y chromosome loss — such as high blood pressure, excess weight, diabetes and lack of exercise. But
only smoking and older age showed an effect.
And, the effect appeared to be
more pronounced the more someone smoked, according to the study.
On the bright side, Forsberg pointed out,
former smokers were similar to men who had never smoked. That might give male smokers some extra motivation to quit, he said.
And what about women? They lose X chromosomes in their cells as they age, Bialer said. But the possible health consequences are not known.
Smoking Can Erase Y Chromosome From Cells | Organic Health
@haman10
Dumanski and his colleagues are also planning follow-up studies to better understand how cellular Y chromosome deficiency might cause poor health. The researchers
hypothesize that the Y chromosome loss may be skewed toward a specific population of blood cells that become immune cells known to fight cancer. Unable to function normally, the crippled cells may allow disease and cancer to take hold.
__________________________________________________________________________
In a study in the journal Science, researchers at Sweden's Uppsala University found that Y chromosomes, which are important for sex determination and sperm production, more often disappear from blood cells of smokers than those of men who have never smoked or of men who have kicked the habit.
Since only men have Y chromosomes, the finding offers a possible answer to why smoking is a greater risk factor for cancer among men than women.
'This ... may in part explain why men in general have a shorter life span than women and why smoking is more dangerous for men.
Epidemiological data show male smokers have a higher risk of developing non-lung forms of cancer than women who smoke.
Read more:
Smoking can erase the Y Chromosome in men, researchers warn | Daily Mail Online
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