A person can be exposed to
asbestos by inhaling or ingesting microscopic asbestos fibers. The fibers can
become lodged in the mesothelial lining of primary organs, such as the lungs.
Over time, damage caused by the fibers can result in the development of
cancerous tumors.
The exact method by which
asbestos causes mesothelioma is still being researched, but medical professionals
have formulated several theories for further exploration:
Inflamed cells
Asbestos causes mesothelial cells
to become irritated and inflamed, which leads to irreversible scarring,
cellular damage and cancer.
Genetic changes
Asbestos fibers enter mesothelial
cells and disrupt the natural functions of cellular division, resulting in
genetic changes that lead to cancer.
Cancerous mutations
Asbestos causes the production of
free radicals, which are molecules that damage DNA and cause healthy cells to
undergo cancerous mutations.
Uncontrolled growth
Asbestos can trigger cellular
production of oncoproteins, which cause mesothelial cells to ignore normal cell
division restraints and become cancerous.
The factor uniting these theories
is that asbestos leads to cellular damage that disrupts the natural cell cycle.
Once normal function of the cell cycle is lost, cells begin to divide and grow
uncontrollably. These cells then accumulate into tumors that trigger
mesothelioma symptoms.
In a 2010 study conducted by the
National Cancer Institute and the Mesothelioma Applied Research Foundation,
researchers may have confirmed a primary way that asbestos causes mesothelioma.
The study reported that asbestos damages cells through a process researchers
dubbed "programmed cell necrosis." This process involves the release
of a molecule known as "high-mobility group box 1 protein" (HMGB1),
which triggers a chronic inflammatory reaction that causes tumor growth.