Skip to comments.Enzyme behind cancer identified
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.
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?
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.
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.
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.
Very interesting. If I remember correctly, this was one of the key enzymes in the Krebs cycle which is the foundation of metabolism.
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.
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.
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.
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.
That graphic just gave me a seizure
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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 thats coming up for the Komer (sp?) foundation. Im sure that Ill be shaken down for a donation. Im hoping I can put it in an envelope and give it to someone besides my sister in law. If so, Ill write it for $.99 which will cost much more to process than its worth. Any other suggestions?
I remember having hissy fits trying to learn the Krebs Cycle in Medical School
It was a tough act in rote memorization
Your graphic of Confucius at the bottom can be condensed to two words:
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.
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.
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.
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.
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.
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.
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).
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, ...)
Confront them about their PC BS!
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 -a conclusion further confirmed in a recent National Cancer Institute report .
While numerous case-control studies have suggested that abortion may moderately increase the risk of breast cancer , the nature of these studies makes the accuracy of their results questionable . 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)
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.
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.
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.
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.