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Tumor Suppression Gene Discovered
An anonymous reader writes ScieceDaily is reporting that researchers at Ohio State University may have identified a new and unusual tumor suppression gene that could effect cancers of the lung, head, and neck. From the article: "The gene, known as TCF21, is silenced in tumor cells through a chemical change known as DNA methylation, a process that is potentially reversible. The findings might therefore lead to new strategies for the treatment and early detection of lung cancer, a disease that killed an estimated 163,510 Americans in 2005. The study could also lead to a better understanding of the molecular changes that occur in tumor cells during lung-cancer progression."
Gee, why would anyone want to effect cancer? I would think there are enough carcinogens out there to effect cancer already.
Oh well, what the hell...
To be honest, I have to disagree that this is stellar news for smokers. Even if you do have an easy cure for lung cancer available, this doesn't mean go ahead and smoke to your heart's content.
Lung cancer isn't the only reason to stop smoking. It discolors your teeth, makes you stink and disturbs people around you.
..are areas that I have worked in, at the Sloan-Kettering Cancer Center in NYC. I am not really that enthusiastic about this find. There are an enourmous amount of "cancer supressing genes" but very few yield useful clinical results. This seems to be a case of over-hyping (which occurs all the time) of a scientific find.
Don't forget emphysema. I think that's a tad worse than discolored teeth, or the stench that surrounds you.
Someone save me from this sanity.
"Hack, hack, cough. Damn emphysema!"
Actually, a good percentage of lung cancers aren't caused by smoking. I don't recall the percentage, but it's significant. It's unfortunate that those suffering through lung cancer have the stigma that "they deserve it," as that's not true in all the cases, and nobody deserves to suffer though cancer. -- Paul
OpenSource.MathCancer.org: open source comp bio
A quick survey of my four grandparents, while a small sample, is enlightening.
Maternal Grandmother
Sendentary job, never smoked. developed diabetes at age 70, constant blood pressure problems - died age 84 after years of suffering strokes
Maternal Grandfather
Athlete and Gallipoli Veteran - Not a smoker to my knowledge. Suffered with high blood pressure and died age 84 due to complications from Parkinson's disease.
Paternal Grandmother
Overweight to the point of obesity. Gave up smoking when in her 40s
Died age 71 from complications resulting from Type 2 diabetes.
Paternal Grandfather
Stevedore and tennis coach. Smoked all his adult life until age 78. Always has two schooners (large glass) of beer every evening. Recently celebrated his 90th birthday. Suffers from Emphysema (not yet on oxygen) which will probably eventually kill him.
From this small sample, it appears that lack of fitness will kill you just as quick if not quicker than smoking.
So Slashdotters, instead of poking fingers at the smokers, get up, turn off your computer, get out from your Mother's basement and go for a walk. It might save your life.
(I don't smoke btw)
If my call is important, why am I talking to a recording?
To my knowledge DNA methylation cannot be reversed and DNA methylase has not been found to exist yet. The only way DNA de-methylation at a particular CpG site in DNA can occur is by DNA replication(cell division), where replication of DNA gives an unmethylated CpG site.
Huh?
Last time I looked the point of DNA methylation was this:
One of the four bases (I forget which) has a methylation site, and the DNA replication mechanism normally copies the methylation state as well as the base type. This effectively makes the genome a FIVE-letter alphabet.
In a fraction of complex life forms that includes humans, the methylation state of all or much of the genome is "reset" to a particular configuration during the production of the gamet cells - at least those of one of the sexes.
This allows methylation to be used, gene by gene, or set-of-genes by set-of-genes, as a switch during tissue differentiation. Methylating (or de-methylating) a particular site can turn a gene's expression on or off (or perhaps modulate its expression magnitude) and the state of the switch is retained through cell replication as the tissue grows into its proper size and form, and as cells are replaced later.
Of course this means that gene expression errors can occur (and accumulate with age or exposure to toxins) due to improper copying or changing of the methylation state, just as they can occur due to improper copying of, damage to, or editing of, the base sequence itself.
= = = =
So now scientists have identified a gene which is inactivated by methylation and whose normal function is one of the roadblocks that a broad class of cancer types must eliminate as they progress to full-blown pathologies.
And of course there's a speculation that, since it's a switch, there might be a treatment potential using drugs to flip it to the non-cancer-associated state, which would make the cancerous tissue eitehr revert to normal or at least to a less invasive earlier stage of the disease.
I agree there's a potential for such a treatment. But I suspect that just dosing with a generic state-setting drug may cause havoc by resetting the switches on other genes as well. I'd expect that practical treatments will have to wait for development of a drug that's specific to that PARTICULAR gene's methylation state, or at least to the methylation sites of a narrower set of genes, rather than scattergunning the whole genome.
Of course it's possible that scattergun demethylation might not be a total disaster. Perhaps important cell differentation steps might not be totally dependent on the methylation, but include something that tends to set the switch again. Perhaps the result would be reversion to a more stem-cell like state that could "figure out" what tissue to be once again. Or perhaps even the havoc of the reset is better than dying of an otherwise incurable cancer type.
But I'm betting that more focus will be needed for a practical treatment.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
BTW I second that call to break away from that computer and take a walk.
But there's no reason to pretend obesity is a killer just like tobacco. It's not even in the same league.