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Enzyme behind cancer identified
The Times of India ^ | 16 Mar 2008, 1026 hrs IST | The Press Trust of India (PTI)

Posted on 03/16/2008 5:54:39 AM PDT by CarrotAndStick

LONDON: Scientists have discovered a key part of the mechanism that makes cancer cells so dangerous, a breakthrough which they claim could enable them to stop tumour growth in its tracks.

The scientists, led by researchers from the Harvard Medical School, have identified an enzyme which enables cancer cells to consume the huge quantities of glucose they need to fuel uncontrolled growth.

Though the key enzyme, known as pyruvate kinase, comes in two forms, the researchers found that only one -- the PKM2 form -- enables cancer cells to consume glucose at an accelerated rate.

"Because PKM2 is found in all of the cancer cells that we have examined, because it is not found in most normal adult tissues, and because it is critical for tumour formation, this form of pyruvate kinase is a possible target for cancer therapy," according to lead researcher Prof Lewis Cantley.

In their experiment on rodents, when they forced cancer cells to switch to other form of pyruvate kinase in the laboratory by knocking out production of PKM2, their growth was curbed.

Subsequently, when the cells were injected into the laboratory mice, they were much less able to produce tumours, the researchers reported in the Nature journal.


TOPICS: Extended News; News/Current Events; Technical
KEYWORDS: cancer; dna; enzyme; tumor

1 posted on 03/16/2008 5:54:40 AM PDT by CarrotAndStick
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To: CarrotAndStick

question for cancer survivors. I survived or maybe I should say am in recovery from melanoma. My dear sister in law and one of my best friends are both big supporters of Walk for the Cure. Oddly enough, they are both pretty conservative but abortion is not their primary issue as it is mine. So this sister in law has invited me to go to the luncheon that’s coming up for the Komer (sp?) foundation. I’m sure that I’ll be shaken down for a donation. I’m hoping I can put it in an envelope and give it to someone besides my sister in law. If so, I’ll write it for $.99 which will cost much more to process than it’s worth. Any other suggestions?


2 posted on 03/16/2008 6:02:08 AM PDT by Mercat (The LORD is my Banner)
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To: CarrotAndStick

boobkmark


3 posted on 03/16/2008 6:05:21 AM PDT by SE Mom (Proud mom of an Iraq war combat vet)
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To: SE Mom

:^)


4 posted on 03/16/2008 6:05:52 AM PDT by CarrotAndStick (The articles posted by me needn't necessarily reflect my opinion.)
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To: neverdem

ping


5 posted on 03/16/2008 6:06:36 AM PDT by sweetiepiezer
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To: CarrotAndStick
PKM2 is a primary pyruvate kinase enzyme type in muscle tissue, where rapid processing of glucose is obviously a useful feature. This protein has been shown to interact with thyroid hormone, and thus may mediate cellular metabolic effects induced by thyroid hormones.

Nearly 80 years ago, scientist Otto Warburg observed that cancer cells perform energy metabolism in a way that is different from normal adult cells. Many decades later, this observation was exploited by clinicians to better visualize tumors using PET (positron emission technology) imaging. But it has not been known exactly how tumor cells perform this alternate metabolic feat, nor was it known if this process was essential for tumor growth.

Pyruvate kinase has been extensively studied since the mid 1960s, as the enzyme's deficiency in human erythrocytes is the most common cause of hemolytic anemia. Lately, the enzyme was linked to other diseases related to both glucose and oxygen utilization, such as diabetes, blood and brain phenylketonuria, and angiogenesis.

http://bidmc.harvard.edu/tools/newsnow/pr_out.asp?pr_id=1793

It has been noted in 2007 to be up-regulated in a majority of colorectal Ca, and can be measured in plasma of patients with advanced breast cancer. In mice models, it is widely expressed in cancer cell types.

6 posted on 03/16/2008 6:20:50 AM PDT by HangnJudge
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To: Mercat

The Susan G Komen Foundation is for breast cancer research. I believe they donate some of their money to Planned Parenthood. I used to do the Revlon Walk for the Cure. I now occasionally sponsor friends but don’t do the walk myself. Cancer research is really important but foundations like this shouldn’t be funding Planned Parenthood.


7 posted on 03/16/2008 6:20:53 AM PDT by originalbuckeye
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To: CarrotAndStick

Very interesting. If I remember correctly, this was one of the key enzymes in the Krebs cycle which is the foundation of metabolism.


8 posted on 03/16/2008 6:23:07 AM PDT by Pharmboy (Democrats lie because they must.)
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To: Mercat
FWIW, it looks like a pretty good charity....

Susan G. Komen for the Cure

9 posted on 03/16/2008 6:25:53 AM PDT by mewzilla (In politics the middle way is none at all. John Adams)
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To: originalbuckeye

Yes. I know all that and I don’t walk either but like I said, one of my best friends does so I pay some money to sponser her (she does the 60 mile walk at least once a year). My sister in law is also a breast cancer survivor. She doesn’t do the long walk but the short one and is the one who has invited me. I think I’ll do the minimum gift and enjoy myself. If, however, they do start talking about abortion, I’ll politely excuse myself and leave.


10 posted on 03/16/2008 6:28:07 AM PDT by Mercat (The LORD is my Banner)
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To: Mercat
And one other link...

Komen Controversy

11 posted on 03/16/2008 6:29:24 AM PDT by mewzilla (In politics the middle way is none at all. John Adams)
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To: SE Mom

JMO, but the Komen Foundation is a Brast Cancer Foundation. Everyone has their primary concerns, and even if abortion isn’t theirs, curing cancer seems to be, at least what I gleaned from your article.

So I imagine that since they support Walk for the Cure, and the Komen Foundation, cancer is their primary concern.

Is the money going to cancer research in part or in total to fund abortions, or is it all going to cancer research?

IF it is going to support abortion (even in part) then by all means give only 99 cents, or even nothing with a note explaining why you won’t support the slaughter of the innocents.

On the other hand, IMHO, giving $.99 is a slap in the face to other cancer survivors simply because you don’t agree with their politics concerning abortion.


12 posted on 03/16/2008 6:30:05 AM PDT by DaiHuy (I think owning a gun doesn't make you a killer, it makes you a smart American. (George Carlin)
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To: Pharmboy


http://en.wikipedia.org/wiki/Citric_acid_cycle
13 posted on 03/16/2008 6:30:58 AM PDT by HangnJudge
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To: CarrotAndStick

Interesting finding.

But as a person who does fairly extensive readings in biology and aging, I somewhat object to the title “Enzyme behind cancer identified”

There is no single “enzyme behind cancer”. Cancer cells are very different from normal cells, and have a very different set of gene expressions. Different cancers have different properties.

In truth, we will probably never “cure” cancer. There are too many different types. There are too many different causes. And even if we are able to diagnose and cure a particular type, it is highly likely that new types can in fact develop because of changes to the genome over time.


14 posted on 03/16/2008 6:31:01 AM PDT by djf (She's filing her nails while they're draggin the lake....)
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To: SE Mom

JMO, but the Komen Foundation is a Breast Cancer Foundation. Everyone has their primary concerns, and even if abortion isn’t theirs, curing cancer seems to be, at least what I gleaned from your article.

So I imagine that since they support Walk for the Cure, and the Komen Foundation, cancer is their primary concern.

Is the money going in part or in total to fund abortions, or is it all going to cancer research?

IF even a penny is going to support abortion then by all means give only 99 cents, or even nothing with a note explaining why you won’t support the slaughter of the innocents.

On the other hand, IMHO, giving $.99 because you don’t agree with your sisters stance on abortion is a slap in the face to others who are fighting the disease.


15 posted on 03/16/2008 6:36:17 AM PDT by DaiHuy (I think owning a gun doesn't make you a killer, it makes you a smart American. (George Carlin)
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To: HangnJudge

That graphic just gave me a seizure


16 posted on 03/16/2008 6:39:43 AM PDT by Archie Bunker on steroids (Hillary Supporters ....... Fags and Hags)
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To: Mercat; informavoracious; larose; RJR_fan; Prospero; Conservative Vermont Vet; ...
+

Freep-mail me to get on or off my pro-life and Catholic List:

Add me / Remove me

Please ping me to note-worthy Pro-Life or Catholic threads, or other threads of interest.

My dear sister in law and one of my best friends are both big supporters of Walk for the Cure. Oddly enough, they are both pretty conservative but abortion is not their primary issue as it is mine. So this sister in law has invited me to go to the luncheon that’s coming up for the Komer (sp?) foundation. I’m sure that I’ll be shaken down for a donation. I’m hoping I can put it in an envelope and give it to someone besides my sister in law. If so, I’ll write it for $.99 which will cost much more to process than it’s worth. Any other suggestions?

17 posted on 03/16/2008 6:41:07 AM PDT by narses (...the spirit of Trent is abroad once more.)
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To: Archie Bunker on steroids
That graphic just gave me a seizure

I remember having hissy fits trying to learn the Krebs Cycle in Medical School
It was a tough act in rote memorization

18 posted on 03/16/2008 6:44:01 AM PDT by HangnJudge
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To: HangnJudge
Just clicked on your homepage.

Your graphic of Confucius at the bottom can be condensed to two words:

"Character matters."

Cheers!

19 posted on 03/16/2008 6:49:33 AM PDT by grey_whiskers (The opinions are solely those of the author and are subject to change without notice.)
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To: Mercat; wagglebee

Okay, but before you go, please tell them about the link between abortions and increased incidence of breast cancer. Wagglebee, do you have some handy links or other convenient pack of info that she can use to get this info out to her family and friends?

IMHO, every dime The Komen Foundation takes in, is a dime diverted away from the fight against cancer.


20 posted on 03/16/2008 6:57:40 AM PDT by LilAngel (FReeping on a cell phone is like making Christmas dinner in an Easy Bake Oven)
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To: grey_whiskers
"Character matters."
Cheers!


Ziggy would approve


21 posted on 03/16/2008 7:00:06 AM PDT by HangnJudge
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To: Mercat

Why would you want to go to a luncheon sponsored by an organization like Susan G. Komen, which gives money to Planned Parenthood? If you abhor the organization, don’t go through this little charade with the check and don’t accept their food. Stand by your principles and decline the invitation.


22 posted on 03/16/2008 7:11:03 AM PDT by ottbmare
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To: CarrotAndStick
Original references

http://www.nature.com/nature/journal/v452/n7184/abs/nature06667.html
http://www.nature.com/nature/journal/v452/n7184/abs/nature06734.html

Growth factors stimulate cells to take up excess nutrients and to use them for anabolic processes. The biochemical mechanism by which this is accomplished is not fully understood but it is initiated by phosphorylation of signalling proteins on tyrosine residues. Using a novel proteomic screen for phosphotyrosine-binding proteins, we have made the observation that an enzyme involved in glycolysis, the human M2 (fetal) isoform of pyruvate kinase (PKM2), binds directly and selectively to tyrosine-phosphorylated peptides. We show that binding of phosphotyrosine peptides to PKM2 results in release of the allosteric activator fructose-1,6-bisphosphate, leading to inhibition of PKM2 enzymatic activity. We also provide evidence that this regulation of PKM2 by phosphotyrosine signalling diverts glucose metabolites from energy production to anabolic processes when cells are stimulated by certain growth factors. Collectively, our results indicate that expression of this phosphotyrosine-binding form of pyruvate kinase is critical for rapid growth in cancer cells.

23 posted on 03/16/2008 7:19:35 AM PDT by HangnJudge
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To: ottbmare

I value my sister in law and enjoy every opportunity to be with her. I’m not going to not go. I certainly wouldn’t go to a Planned Parenthood luncheon or even a March of Dimes luncheon. I wouldn’t go to this one but for these two women. I respect them more than distrust the organization. I’ve read all the websites and that isn’t going to change.


24 posted on 03/16/2008 7:45:51 AM PDT by Mercat (The LORD is my Banner)
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To: Mercat

Donate to the American Cancer Society. It is a wonderful group. I am currently undergoing cancer treatment, and ACS has been just wonderful for arranging transportation, support, etc.


25 posted on 03/16/2008 7:54:20 AM PDT by ought-six
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To: ought-six

I’m glad to know that. My husband and I are self employed. We strongly believe in charitable living and use our skills and our contacts, he with tenants, I will clients, to give time and treasure in our community. We don’t do a lot of the type of giving that shows up on our tax returns. We probably should. I need to get back in to tything but am not too happy with my Church right now.


26 posted on 03/16/2008 7:57:40 AM PDT by Mercat (The LORD is my Banner)
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To: Pharmboy
If I remember correctly, this was one of the key enzymes in the Krebs cycle which is the foundation of metabolism.

Close. It's actually near the end of glycolysis. Glycolysis is the metabolic pathway that converts glucose into acetyl CoA, which then enters into the Krebs cycle (now usually called the citric acid or tricarboxylic acid (TCA cycle).

27 posted on 03/16/2008 7:58:35 AM PDT by poindexter
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To: CarrotAndStick

I’m scanning FR today for articles to read and comment on AFTER St.Pat’s... Got to prepare for this eve & tommorow you know...

I’ll have to look more into this research later. For now, my first thoughts are that this may be a very fruitful avenue to attack rapidly growing tumors (lung, brain, etc.) but may not be so useful against slow ones (prostate, ...)


28 posted on 03/16/2008 8:32:23 AM PDT by AFPhys ((.Praying for President Bush, our troops, their families, and all my American neighbors..))
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To: Mercat; CarrotAndStick; sweetiepiezer; Coleus; hocndoc
Any other suggestions?

Confront them about their PC BS!

Factors That Do Not Increase Risk of Breast Cancer

Abortion
Although there has been some controversy in the past about the relationship between abortion and breast cancer risk, the current body of evidence now strongly supports no link between the two [253]-a conclusion further confirmed in a recent National Cancer Institute report [254].

While numerous case-control studies have suggested that abortion may moderately increase the risk of breast cancer [255], the nature of these studies makes the accuracy of their results questionable [253]. Case-control studies rely on the reporting of past behavior, and when it comes to a sensitive topic like abortion, this can have a significant impact on the precision of the information gathered. The cases in these studies-the women with breast cancer-may be much more likely to provide complete information about their abortion history than the controls-the women without breast cancer. Such differences in the completeness of reporting can compromise the accuracy of the study results.

Studies called cohort studies, on the other hand, are much more likely to provide accurate results on the topic of abortion because they tend to gather sensitive information before women are diagnosed with breast cancer. And the results from cohort studies looking at this topic clearly show that abortion does not increase the risk of breast cancer [253,256-265].

CORAM, MT. SINAI, PORT JEFFERSON STATION (CMP) FOLLOW-UP INVESTIGATION pdf link from NY State Dept. of Health

(CANCER RISK FACTORS with references starts on page 25.) BREAST “The importance of reproductive factors in affecting breast cancer risk has been known for a long time. Women who have never given birth (or had a full-term pregnancy) are at a higher risk for breast cancer compared to women who have carried a pregnancy to term.”(Page 26)

29 posted on 03/16/2008 11:20:43 AM PDT by neverdem
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To: Mercat
Any other suggestions?

Two suggestions...

1. Don't go.

2. Go and don't donate.

There are many worthwhile charities that make good use of your money. Do not waste your time...or theirs...on one you do not support. Tell you friends the truth about why you won't donate to their cause...but you need to respect their choice to support their cause. The organization they are supporting does a lot of good. Reasonable people can differ on their choice of charities...
30 posted on 03/16/2008 11:29:15 AM PDT by goldfinch
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To: Mercat

If you don’t approve of abortion, don’t support the Komen Foundation. They have been involved in abortion in various ways for many years. Not long ago it became widely known (it was known before but the media did not pick it up) that they donate directly to Planned Parenthood. It’s also been questioned whether the type of “research” they support involves fetal tissue from aborted babies.

If you feel awkward because friends are asking you to donate, you could just say that you have other organizations you’re contributing to at this time. Or you could be honest and say you have concerns donating funds that might ultimately be used for abortion.

Difficult situation, I wish you the best.


31 posted on 03/16/2008 1:17:50 PM PDT by baa39 (Defend our troops! see my profile page)
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To: HangnJudge; poindexter

Thanks for your graphic and the correction. The last biochem course I took was in 1968, so it is a bit hazy, but your posts brought it back.


32 posted on 03/16/2008 2:30:17 PM PDT by Pharmboy (Democrats lie because they must.)
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To: Pharmboy
Ongoing discussion on SlashDot
http://science.slashdot.org/science/08/03/16/1717253.shtml
33 posted on 03/16/2008 3:32:17 PM PDT by HangnJudge
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To: Pharmboy
And a known compound that inhibits Pyruvate Kinase
Dichloroacetic acid, often abbreviated DCA

A study published in January 2007 by researchers at the University of Alberta, testing DCA on in vitro cancer cell lines and a rat model, found that DCA restored mitochondrial function, thus restoring apoptosis, killing cancer cells in vitro, and shrinking the tumors in the rats.

http://en.wikipedia.org/wiki/Dichloroacetic_acid

34 posted on 03/16/2008 3:39:15 PM PDT by HangnJudge
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To: HangnJudge

Interesting—I saw the DCA stuff in the discussion you pointed me to. I hope this turns out to be an important foundation issue for neoplastic cells. And thanks for the follow-up.


35 posted on 03/16/2008 3:55:46 PM PDT by Pharmboy (Democrats lie because they must.)
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