Mesothelioma Pathophysiology: How Asbestos Fibers Damage Cells
Mesothelioma develops when asbestos fibers enter the body and disrupt normal cell function. These fibers are sharp, durable, and resistant to breakdown. Once inhaled or ingested, they lodge in the lining of the lungs, abdomen, or heart.
Fiber Inhalation and Retention
- Asbestos fibers bypass natural defense mechanisms in the respiratory tract.
- They penetrate deep into the alveoli and pleura.
- Body cannot easily clear them, so they remain for decades.
Cellular Damage
- Fibers physically pierce cell membranes, causing injury.
- They generate reactive oxygen species (ROS) and reactive nitrogen species (RNS).
- These free radicals damage DNA, proteins, and lipids.
Chronic Inflammation
- Immune system tries to attack the fibers but fails to eliminate them.
- Persistent inflammation leads to cytokine release.
- This environment promotes abnormal cell growth and survival.
Genetic and Epigenetic Changes
- DNA damage accumulates over time.
- Tumor suppressor genes like p53 and BAP1 may be inactivated.
- Epigenetic changes alter gene expression, further driving malignancy.
Tumor Formation
- Damaged mesothelial cells begin uncontrolled division.
- Over years, this leads to malignant mesothelioma.
- The latency period can range from 20 to 50 years after exposure.
Key Takeaway
Asbestos fibers cause mechanical injury, oxidative stress, chronic inflammation, and genetic mutations. Together, these processes transform healthy mesothelial cells into cancerous ones.