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New Links Found Between Bacteria and Cancer
Shipud writes "A recent study by a group at the University of Maryland School of Medicine shows that bacterial DNA gets transferred to human cells, in a process known as lateral gene transfer, or LGT. LGT is known to occur quite commonly between bacteria, including bacteria of different species. In fact, that is how antibiotic resistance is transferred so quickly. The team has shown that certain types of tumor cells acquire bacterial DNA that may play a role in tumor progression. Another group at the University of North Carolina, Chapel Hill has shown that gut inflammation leads to a radical change in the microbial population there, which encourages growth of E. coli that can disrupt the inflamed cells' DNA, leading to cancer. Both studies enable us to ask new questions such as: how does inflammation change the landscape for bacterial colonization? Can bacteria indeed harness inflammation — and then cancer — to flourish and remove competitors from their newly found ecosystem? And can we use this information to fight cancer?"
Also termed lateral gene transfer
It's still evolution. It's change in response to the environment. LGT (Lateral Gene Transfer) is a Big Deal in the bacterial world - it evolved. You can amplify the effect by causing a selection pressure (ie, put an antibiotic in the flask). But, you can also have de novo point mutations that cause antibiotic resistance - that's done thousands, if not millions of times a day all over the planet. The clever little protists have figured out an even more efficient way to do things.
That's certainly evolution in action.
Faster! Faster! Faster would be better!
The male isn't really transferring genes laterally though. They're being combined with the females egg and falling squarely in the realm of fertilization/reproduction. With that said. There is some evidence that there is a lateral transfer of genes between the mother and baby. Male DNA has been found in the brains of mothers' of sons. My understanding is it's harder to find evidence that the sons receive genes from the mother laterally since he will already have an X chromosome from her.
It's been a while since "Human Infectious Diseases"; but my understanding is that the inflammatory response is a component of the 'Innate immune system', a very, very, old, comparatively rudimentary; but fast-responding complement to the more recent immune system with pathogen-specific antibodies and killer T cells and things.
The inflammation itself is partially a cause of the changes that tissues undergo to do damage control and partially serves to increase supply of particular chemicals and cell types at the site of the issue(leading to the redness and swelling that are most obvious.
As for it being associated with a laundry list of unpleasant diseases, I'm told that it's a combination of:
1. Inflammation is (when it's working correctly) a stress response/damage control mechanism, that kicks in in response to certain environmental stresses and pathogens, so people who are inflamed a lot are also unpleasantly likely to be people who are being exposed to something that isn't doing them any good.
2. Like scarring, inflammation is one of those 'unpleasant; but it beat dying for most of evolutionary history' arrangements that wreaks a lot of havoc in the process of saving you from infection or tissue damage; which was a much better trade-off before we had access to modern medicine to deal with our acute illnesses and injuries; but also wanted to live to be 90.
3. The immune system, innate and acquired, is sort of your own personal military-industrial complex, and has a nasty tendency to sometimes go off the rails and start killing civilians in an increasingly paranoid response to minimal or nonexistent security threats, giving us autoimmune disorders.
A bio-diverse flora reduces the chance of cancer and many other issues. So no, antibiotics are bad for you in the long run, but can help you survive the short-run. You can always have a fecal transplant from someone with a good flora. It's as nasty as it sounds and it is an official medical procedure.
Fun science fact: it takes twice as much MSG to kill a rat than it does salt if you count by number of molecules, and 5.5x as much if you count by mass.
Bio questions? Ask me to start a Q&A journal. Computer analogies available for most topics!
The immune system, innate and acquired, is sort of your own personal military-industrial complex, and has a nasty tendency to sometimes go off the rails and start killing civilians in an increasingly paranoid response to minimal or nonexistent security threats, giving us autoimmune disorders.
Consider the evolutionary theory of pathogen Molecular Mimicry -- infectious agents that adopt motifs that resemble normal host antigens should have a selective advantage. In an absolute form, the theory is not completely accepted -- immunological cross-reactivity between host and pathogen could be due to evolution, or it could be due to chance -- and examples exist that support either case. But I think it is likely that the mechanism operates at least some situations.
The consequence is that a somewhat over-active immune system may actually be the optimum state, with the particular degree of paranoia being the amount that best balances the trade-off between autoimmune disease risk against infection outcomes.