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Cancer
Forum and Discount
Information: Click Here.
Here is an article on a link between bacterial
infections and certain cancers. In these cases, we believe
colloidal silver may very well be valuable as it is harmless
and may kill these bacteria. Keep in mind, however, we are
not doctors. This is just our opinion based on our experience
with colloidal silver.
Is Bacterial Infection
Carcinogenic?
by Kirstie Saltsman
Posted February 2, 2001 · Issue 95
from HMS BEAGLE
Abstract
Can bacteria cause cancer? The author discusses the discovery
of a link between bacterial infection and cancer, the
mechanisms by which bacteria cause cancer, and the potential
for treatment. Although his work was later called into
question, Johannes Fibiger, the winner of the 1926 Nobel Prize
in physiology, may not have been too far off the mark. He was
awarded the prize for his discovery that a
parasitic worm, Spiroptera carcinoma, causes gastric tumors in
rats. While dissecting rats infected with the tuberculosis
bacterium, he noticed that some had stomach growths, each of
which contained a parasitic worm. The growths later proved to
be unrelated to the parasite, and doubt was even cast upon his
assertion that the growths were malignant. Nevertheless, the
idea that an infectious organism could cause cancer turned out
to be accurate and groundbreaking.
Infectious organisms cause about 15% of cancers. By the early
1970s, nearly 30 mammalian oncoviruses had been discovered,
and it is now estimated that over 15 percent of cancers
worldwide are caused by infectious organisms. Although the
idea that viruses can cause cancer has been accepted for
decades, the idea that bacteria can cause cancer has begun to
attract attention only recently. The most established instance
of this is the link between Helicobacter pylori infection and
gastric cancer, but bacterial infections have also been
implicated in other types, such as colon and gall bladder
cancers.
The mechanisms by which bacteria cause cancer appear to be
quite different from those used by viruses. Viruses, by
inserting their genomes into host cell chromosomes, can alter
expression patterns of host cell genes and disrupt the
intricately regulated process of growth control. Human
papillomavirus (HPV), for example, which is associated with
cervical cancer, induces cellular transformation by inhibiting
the host cell tumor suppressors p53 and Rb. In addition, as in
the case of human immunodeficiency virus (HIV), viral
infection can cause depletion of the immune system, leaving
the host less able to destroy cancerous or precancerous
cells that arise by spontaneous mutation. Kaposi's sarcoma and
non-Hodgkin's lymphoma are now considered AIDS-defining
malignancies. Bacterial infections can cause tumors via
inflammation. In contrast, bacteria are thought to cause
cancer largely via an indirect mechanism. It seems that it is
the host's response to infection - inflammation - which
damages cells and predisposes them toward becoming cancerous.
Phagocytes drawn to the site of infection release reactive
oxygen and nitrogen species that can cause DNA mutations and
damage cellular proteins and lipids. In addition, loss of
cells at the site of infection stimulates cell proliferation
in order to regenerate the tissue, a process that leaves the
site vulnerable to tumor formation. Proliferating cells are
one step closer to uncontrolled cell growth, and are also
susceptible to acquiring mutations due to errors in DNA
replication. Although inflammation and its molecular
consequences are now known to be major risk factors in
developing gastric adenocarcinoma in those infected with H.
pylori, it was not until fairly recently that a connection was
made between the two. Although the association between H.
pylori and gastric cancer is among the better known examples
of a bacterial cause for cancer, Julie Parsonnet, associate
professor of medicine at the Stanford University School of
Medicine's proposed ERID (Emerging and Re-emerging Infectious
Diseases) program, points out that it is not the first such
association to be made. She says that "people have long
recognized that chronic skin and bone infections with bacteria
can lead to aggressive skin cancers." Although it had
been suspected for some time that a widespread environmental
determinant was an etiologic factor in the development of
gastric cancer, it was not until 1991 that H. pylori, a
gram-negative, rod-shaped bacterium, was found to be involved.
Over 50 percent of the world's population is infected with H.
pylori; however, in most cases, infection has no serious
clinical consequences. A complex interplay between host and
bacterial factors seems to determine the outcome of infection.
Among the bacterial factors is a group of genes - whose
functions are largely unknown - localized in a cassette called
the cag pathogenicity island. cag+ strains are more virulent
than their cag-counterparts, and there is a strong correlation
between infection with cag+ strains and the occurrence of both
gastric cancer and duodenal ulcer disease. However, those with
H. pylori-induced ulcers are less likely than the general
population to contract gastric cancer, a finding that
underscores the importance of host factors in disease outcome.
Host genes influence susceptibility to bacterial tumorigenesis.
Because host factors are thought to influence susceptibility
to disease, a number of research teams are currently trying to
pinpoint disease-predisposing genetic determinants within the
host. Among those that are already known to influence the risk
of gastric cancer is the gene for interleukin-1-beta
(IL-1-beta). Elevated levels of this
cytokine promote inflammation and suppress gastric acid
secretion, which allows for more extensive bacterial
colonization of the stomach. In an attempt to identify other
host genes that influence the risk of gastric cancer, Karen
Guillemin, a postdoctoral research fellow in Stanley Falkow's
lab at Stanford University, has devised a strategy based on
the use of human DNA microarrays and a tissue culture model of
infection. By comparing the host genes induced by the more
virulent cagA+ strain with those induced by a cagA- strain,
she has distinguished a subset that may be involved in
disease. Some of these genes appear to be involved in cell
signaling or in remodeling the cell ultrastructure, both of
which may set a cell on a course toward malignancy. However,
others are likely to promote cancer indirectly by promoting
the growth of virulent strains. "Because infection with
H. pylori is a long-term, often lifetime condition, and
because H. pylori populations are known to undergo a lot of
genetic changes and diversification, similar to viruses, a
complexity that I think will emerge is that certain host genes
will be found to promote particular gastric environmental
conditions that select for more or less virulent
bacteria," says Guillemin. Because only 1 percent of
infected individuals have the misfortune of contracting the
disease, genetic determinants within both host and bacteria
are likely to affect the
outcome of infection. Vaccination against H. pylori may fight
cancer well. The finding that bacterial infections can cause
cancer is exciting because unlike a genetic predisposition or
an environmental factor, infections often can be treated or
prevented. A recent study published in the Journal of the
National Cancer Institute has shown regression of precancerous
lesions upon treatment with antibiotics among a high-risk
population in southwestern Columbia. Other studies are
currently underway. However,
the use of antibiotics is unlikely to take hold as a
widespread preventive measure. The cost would preclude such a
strategy, as would the risk of inducing the emergence of
antibiotic-resistant strains. A more practical approach would
be to induce protection by vaccination, and trials in mouse
models of infection have already yielded promising results.
Oral and intranasal vaccination has provided mucosal immunity,
and systemic vaccination has also been shown to provide
protection in the mouse model. It remains to be seen if these
promising results will be reflected in the human trials
currently being undertaken. In 1966, Peyton Rous was awarded
the Nobel Prize in medicine for his discovery that a virus
(the Rous sarcoma virus) could cause cancer. Now, a mere 35
years later, a significant proportion of liver cancer is
preventable thanks to a vaccine against hepatitis B. In
addition, vaccines against human papillomavirus are now being
tested in an effort to combat cervical cancer, and
Epstein-Barr-virus-related tumors in HIV patients are becoming
less common thanks to immunotherapy. Just as the discovery of
the viral origin of certain cancers led to useful therapies,
it is probably not overly optimistic to expect that the
discovery of a link between bacterial infection and cancer
will soon lead to effective treatments and eventually curtail
the number of lives lost to this deadly disease. Kirstie
Saltsman is a freelance biomedical writer based in Baltimore.
She received her Ph.D. from Harvard in 1996 and did
postdoctoral work at Stanford.
Here is another factor to
consider regarding specifically Breast Cancer.
Almost 90% of Americans use deodorant. Most of it has
an antiperspirant. Most of that is Aluminum Chlorhydrate.
This compound stops all pores from allowing perspiration to
exit the body at the arm pits. A large amount of toxins are
excreted here under normal circumstances. The restriction
of the sweat glands in this area is thought to contribute
to Breast Cancer and Lymphatic Cancer. It only makes sense.
Though studies continue, the evidence is mounting that this
is true.
Our Advanced Colloidal Silver makes a perfect underarm deodorant
for those looking for ways to avoid Breast Cancer and Lymphatic
Cancer.
In our opinion, anyone who is sick with anything should undergo
a course of a month or so of colloidal silver to cleanse the
body of pathogens. It not only kills the pathogens, but takes
the pressure off of the immune system so it can do its job
with less "drag" from the stuff that colloidal silver
so easily kills.
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