Showing posts with label aneuploidy. Show all posts
Showing posts with label aneuploidy. Show all posts

Wednesday, August 22, 2007

Aneuploidy Hampers Yeast Cell Proliferation

We recently discussed on the bayblab whether gross chromosomal abnormalities such as aneuploidy, frequently observed in cancer cells, are cause or consequence of tumor formation. A new paper from Torres et al. shows that yeast with extra chromosomes actually grow slower, suggesting that the relationship between aneuploidy and cancer might be a bit more complex (if the phenomenon holds true on human cells). Then again, maybe yeast are just, well...yeast.


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Monday, July 30, 2007

Duesberg's new hypothesis

As late as 2003 Peter Duesberg, discoverer of the src oncogene, has disputed that the HIV virus is the causal agent of AIDS, the "Duesberg hypothesis" apparently it is caused by drug use and other non-contagious factors. Propagation of this hypothesis, assuming it is incorrect, arguably costs lives. A good blog that debates this hypothesis is http://aidsmyth.blogspot.com/. He was in some good company with this hypothesis, which includes Kary Mullis, the surfing inventor of the polymerase chain reaction.
From a forward by Kary Mullis: (I think there is a whole chapter on this in his book "Dancing naked in the mine field.)
"So I turned to the virologist at the next desk, a reliable and competent fellow, and asked him for the reference. He said I didn't need one. I disagreed. While it's true that certain scientific discov eries or techniques are so well established that their sources are no longer referenced in the contemporary literature, that didn't seem to be the case with the HIV/AIDS connection. It was totally remarkable to me that the individual who had discovered the cause of a deadly and as-yet-uncured disease would not be con tinually referenced in the scientific papers until that disease was cured and forgotten. But as I would soon learn, the name of that individual - who would surely be Nobel material - was on the tip of no one's tongue."
Kenny G (not the saxophonist but a knowledgeable lab rat), informed me that Duesberg is now debunking the idea that mutations initiate cancer. Instead he proposes aneuploidy is the cause.
"Conventional genetic theories have failed to explain why cancer (1) is not found in newborns and thus not heritable; (2) develops only years to decades after 'initiation' by carcinogens; (3) is caused by non-mutagenic carcinogens; (4) is chromosomally and phenotypically 'unstable'; (5) carries cancer-specific aneuploidies; (6) evolves polygenic phenotypes; (7) nonselective phenotypes such as multidrug resistance, metastasis or affinity for non-native sites and 'immortality' that is not necessary for tumorigenesis; (8) contains no carcinogenic mutations."
I actually don't know enough to properly analyze the credibility of this hypothesis, but the history of the scientist immediately makes me skeptical. Is he just good at cherry-picking the literature or is he on to something?
It's good to have people criticize the science, and at least this time he's not potentially costing lives. I wonder why or if he's stopped focusing on the HIV/AIDS issue?


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