It is well known that the best place to pick up a disease is a place with greatest concentration
of diseases - a hospital. However, no one believes that visiting hospitals might increase one's
chances of getting cancer or some other disease that's not supposed to be infectious. But what
if it's true?
Consider this.
Bits of naked bacterial DNA, probably from broken-open bacterial cells may often get integrated
into nuclear DNA of cells of your body but it has been found that this (horizontal gene transfer
from bacteria to a human cell) happens
210 times
more often in tumor cells than in healthy cells.
Bacterial DNA has been found, for example, in acute myeloid leukemia and stomach
adenocarcinoma. But not just any bacterial DNA, it was the DNA of Acinetobacter bacteria and
those of Pseudomonas genus, including Pseudomonas aeruginosa. Both are often picked up in
hospitals. The latter is especially feared for its resistance to multiple antibiotics.
So what's the reason behind this correlation, and is there causation?
Well, the horizontal gene transfer can indeed disrupt the cell genome in a way that allows
runaway cell replication - triggering cancer.
Now, a healthy human cell generally won't exchange DNA with living bacteria, however, there is
a good possibility that naked DNA (from dead bacteria) may get integrated into cell DNA during
cell DNA repair. When does cell DNA damage occur, requiring repair? Generally, during exposure
to high frequency radiation, or toxins.
This is how smoking can cause cancer. A lot of toxins are inhaled with each smoke. This leads to
cell damage, which leads to repair, which may lead to integration of foreign DNA - which may
cause cancer.
Conventional explanation, however, is that toxins damage cell DNA and it is the damage of parts
of that DNA that usually protect us against cancer, which increases the chances of getting
cancer. The DNA repair mechanism is affected so the damage in the cell builds up.
While this can certainly affect the body negatively, especially with many cells affected, how
likely is that this alone will result in [malignant] runaway cell replication? The horizontal
gene transfer may be a more likely cause.
The more one smokes the greater are the chances for cell damage and thus for more
foreign DNA integration.
Now, if you have damaged cells and at the same time you're taking antibiotics, you also have a
lot of dead bacteria, and thus, a lot of naked DNA floating around. This then further increases
the chances that foreign DNA will be picked up during cell DNA repair.
And obviously, it does matter what DNA is picked up (Acinetobacter and Pseudomonas could be more
likely to contain DNA that triggers cancer). Some people can smoke as much as they want and they
may never get cancer. Is it because they don't take antibiotics and don't visit hospitals?
It may be so.
But the hypothesis can be even more strengthened. Consider this.
Usually, it is much more likely for a bacteria to acquire cell DNA than the other way around.
For bacteria, horizontal gene transfer is a replacement for sexual recombination so they
have strong affinity for it and they practice it relatively regularly.
Now let's say one has damaged cells (eg. due to smoking). That means one may have naked
cell DNA floating around that might get picked up by bacteria. And what if that DNA comes from
a tumor cell (let's say a cell damaged by radiation therapy or chemotherapy). Now the gene that
causes runaway cell replication may be carried by the bacteria that picked up the DNA.
And let's say that bacteria is the infectious Acinetobacter, or any other easily transmittable
bacteria. You go to a hospital and pick it up. Later, you smoke a cigarette, take some
antibiotics and,
voila, you get cancer.
Now, I cannot say how likely this is to happen (where are the studies?) but it is definitely
a possible scenario.
UPDATE 2023.08.13
Here's some very interesting synchronicity.
At the same day I published this, a study was published in Science where researchers
actually engineered Acinetobacter to detect tumor DNA. In the process, tumor DNA is integrated
into the genome of the bacteria! So now we have a bacteria specialized to capture
tumor DNA. What could go wrong? If what I hypothesize here had low chance of occurring
before, these chances have now been greatly increased. And they probably will further increase
by human action.
Note that, with this mechanism, cancer (and not just cancer!) becomes effectively an infectious
disease.
I am not a big smoker but I do smoke sometimes. I don't visit hospitals, I don't take
antibiotics. I'm hardly ever sick.
My father does not smoke, but he does inhale toxins occasionally one way or another. He visits
hospitals, he takes antibiotics, he's on all kinds of pills and he had cancer (operated).
I'm not a believer in strong causality though. I would say that a trip to a hospital may be
synchronized with getting cancer - not that the trip caused it. Correlation is there. But
possibility for relative causation exists.
The origin of cancer may involve a simple Darwinian mutation of particular genes - whether in
bacteria, archaea or an eukaryotic cell. However, vertical gene transfer (inheritance) is not
the only way to get them. It may be that, particularly in cases where the risk of cancer is not
a result of inheritance, the horizontal gene transfer by bacteria plays a significant role.
But even in cases where these genes could have been inherited, are we sure that they did and
have had a role in cancer? In example, it may be that a child has picked up a bacteria carrying
the gene from a mother which has been taking chemotherapy, and that is what made the child more
susceptible to cancer - not inheritance (although both may have a role).
A person who has inherited genes that make it more prone to cancer is more likely to
take chemo/radiation therapy and antibiotics, at some point. For this reason, and due to the
fact that orthodox reasoning does not favor horizontal gene transfer, the prime suspect for
increased susceptibility to cancer of descendants may have been inherited genes. While
inheritance certainly may play a role (particularly lifestyle affecting epigenetics) - rather
than causing cancer, it may simply make a person more susceptible to horizontal gene
transfer, which then may lead to cancer.