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."

Comments

Grammar Nazi Alert

[Da Stylin' Rastan]

that could effect cancers of the lung, head, and neck.

it'd be even better if it could affect them too.

Effect

[HermanAB]

Gee, why would anyone want to effect cancer? I would think there are enough carcinogens out there to effect cancer already.

Fix Lung Cancer?

[killeena]

No reason to stop smoking now. Everyone light up!

Re:Fix Lung Cancer?

[Voltageaav]

According to the article, the gene only slows things down. In tests, tumor cells with the gene preasant are smaller, but they're still there. While it's very exciting and will undoubtably lead to new treatments, it's not a cure yet.

Re:Fix Lung Cancer?

[macklin01]

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

Re:Fix Lung Cancer?

[sco08y]

No reason to stop smoking now. Everyone light up!

It's a celebration, bitches!

Re:Fix Lung Cancer?

[ponos]

Actually, a good percentage of lung cancers aren't caused by smoking. I don't recall the percentage, but it's significant.

I have to disagree. Most studies estimate that ~90% of lung cancer patients are smokers. Furthermore, the incidence of cancer in smokers is also increased for other tumor types like oral cancer, laryngeal cancer (this one is practically an exclusive disease of smokers!) and bladder cancer. As a rough estimate, in our research database we have 71 lung cancer patients, 68 of which were smokers.

I could also argue about the prognosis of smokers vs non-smokers, since not all cancers are the same. Stage IIIB, high grade is not the same as stage IIA, low grade, for example. However, this is a more delicate issue and it doesn't really matter that much. As a rule of thumb I'd say (this my estimate, of course) that if someone manages to reach 50-60 pack years (e.g. 30 years * 2 packs per day) and NOT get cancer he is extremely lucky (although he might have died from myocardial infarct or something else before getting cancer).

P.

Re:Fix Lung Cancer?

[radtea]

Several others have already pointed out that roughly 90% of lung cancers are known to be caused by smoking. It is true that 10% are not, just as 50% car accidents are not caused by drunk driving. But that doesn't make drunk driving ok, sensible or sane.

Back in the day when I worked in radiotherapy physics I came to a simple conclusion: if you took all the money being spent on the kind of research I was doing and put it into an modestly effective anti-smoking campaign, you would extend more lives much longer. This was based on the rates of lung and other cancers that were known at the time to be caused by smoking.

For greater context: a single treatment that eliminated 90% of cases of a major cancer with negligable side-effects would be considered a medical break-through of staggering proportions. Most headline-making genetic causes affect a few percent of a specific type of cancer. Even the major tumour-suppressor genes found so far only get into the 10-50% range.

Nothing in the current pipeline of medical miracles comes close to the effect of stopping smoking on lung cancer. And that's ignoring all the other health effects of smoking, from pulmonary emphasema to oral and other cancers.

Smokers do not "deserve" to get cancer. But they are addicted to a substance that is known to cause cancer, and which will almost certainly damage their health and shorten their lives. If it were possible to elimiate that substance it would be equivalent to a huge medical breakthrough. It is not possible to eliminate tabbacco, but it is certainly possible to call it what it is: a deadly, addictive drug being sold to often-willing victims by evil people.

good news for me (and you)

[onetwentyone]

I smoke quite a bit on a daily basis. Yes, I am well aware of my vice. This comes as pretty stellar news for me. Should, at some point in the future, this develop into a worthwhile treatment for cancers, I welcome it.

Here's to our new gene discovering overlords; may you use your powers for good and not to create a new race of super intelligent and immortal beings.

Re:good news for me (and you)

[mendaliv]

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.

Re:good news for me (and you)

[Voltageaav]

Don't forget emphysema. I think that's a tad worse than discolored teeth, or the stench that surrounds you.

Re:good news for me (and you)

[Anonymous Coward]

Yeah, it'll be pretty awesome. The lung cancer won't kill you, so you'll be free to fully enjoy the emphysema and heart disease.

Re:good news for me (and you)

[NoMoreNicksLeft]

They may not get rich, but tobacco is about the only crop worth anything at all, most of the time. My grandfather used to raise 3 or 4 acres back in the early 80s, and I remember him saying it was worth 20 or 30 times as much as corn or soy. Even with all the extra work (tobacco gets stripped by hand).

Re:good news for me (and you)

[ross.w]

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)

Re:good news for me (and you)

[brre]

The CDC numbers say that obesity kills 25,000 Americans a year; tobacco kills 430,000.

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.

DNA methylation reversible?

[aschoff_nodule]

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.

Re:DNA methylation reversible?

[Ungrounded Lightning]

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.

One more breakthrough reported on /.?

[geneing]

Well, as a regular /. reader I'm confused. In the past couple of year I've read dozens of reports here about breakthrough discoveries in cancer treatment and fusion research. However, neither cancer has been cured nor fusion reactors have been built.

What am I missing? :)

Re:One more breakthrough reported on /.?

[Bongo Bill]

In general, any breakthrough discovery requires years of follow-up testing to make sure it's actually valid, and even then whatever comes as a result of it will be of limited use and prohibitively expensive - even assuming that the follow-up testing didn't reveal any new hurdles, which it usually does.

Re:One more breakthrough reported on /.?

[ScrewMaster]

That's not exactly fair ... there are many types of cancer that are routinely cured (cancer is not, after, a single disease) and there have been plenty of fusion reactors built ... they just don't actually generate usable power yet.

might as well get it out of the way....

[Anonymous Coward]

I for one welcome our new 6-packs-a-day cancerless overlords!

Re:might as well get it out of the way....

[mjh49746]

"Hack, hack, cough. Damn emphysema!"

Oncology epidemiology and methylation...

[CupBeEmpty]

..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.

Re:Oncology epidemiology and methylation...

[janneH]

Yeah - add this to the jillion other tumor supressors. These give insights into the pathways that control cancerous cells, but have not been the great targets for therapy one might have thought when the first ones where found. There is nothing obviously special about this particular gene compared to the others. But my read would not be hyping - just someone who doesn't know where the base line is to begin with.

obligatory...

[iced_tea]

arnold quote:

"It's not a tumah!!!!"

--Kindergarten Cop (1990)

premature celebration?

[rahultyagi]

Any student who has taken an undergraduate course about cancer and/or signal transduction will tell you how large these networks are (which means a LOT of intricate pathways to remember for the exams... but I am digressing..). Which means that any genes whose function is as a tumor suppressor is discovered is only one out of many such genes known. Moreover, its not as if a mutation in one gene is ever a chief cause of a given type of cancer. Every mutated gene tends to increase the chances of cancer. I suspect this is another of such genes.

So, good that we have another member of the network pinned down, but this does not mean we are going to get a cure for lung cancer within 4-5 years because of this discovery.

Brain dead moderator alert

[starling]

>i>A perfect example of a careless grammatical mistake that completely reverses the meaning of a sentence.

A comment pointing out an error in the article summary which changes its meaning so drastically is NOT offtopic.

Nothing new to see, move along...

[InternationalCow]

Another example of researchers drumming up their findings. Altered methylation patterns of tumor suppressor gene promotor sequences is nothing new. Neither is the finding of a gene whose product can act to suppress tumor growth. There are many of those.Posting this on slashdot is somewhat overdone. DNA methylation is an exciting target for chemotherapy, that will doutblessly benefit cancer patients in the near future. But it is too early to cry victory.

Hey...

[mikepaktinat]

I do IT support for that guy.

He's a good guy.
I think its crazy how you can work every day with a person and not really know the depth of what they do for a living.