Parasite in Cat Feces Shows Promise in Fighting Ovarian Cancer

• A promising new way to fight cancer found in cat feces.
• Toxoplasma gondii earlier found in infected meat was considered a risk for unborn children and the immunocompromised people.
• The protein from this parasite is found to induce an immune response against ovarian cancer in mice.

Toxoplasma gondii is a parasite that can affect the unborn fetus and also lead to flu-like illness or toxoplasmosis after consumption of infected meat. This leads to the parasite being treated solely as an infectious agent. A new study by Dr. David Bzik and colleagues from Geisel School of Medicine at Dartmouth College have found that a vaccine developed from the parasite activates the immune system against ovarian cancer cells.

Immune Response Against Cancer Cells

Cancer cells are the body’s own cells that start dividing rapidly, increasing in number. The body’s immune system is unable to fight these cells as it recognizes cancer cells as its own cells.

Ovarian cancer

Ovarian cancer is an abnormal growth of cells in the ovaries of a woman and it is the 5^th cause of cancer-related death in women. Though the cause of ovarian cancer is not yet fully understood, it is believed that

• It could be due to genetic abnormalities that arise due to the release of an egg every month.
• Heightened secretion of hormones during ovulation.
• A woman has a 1 in 75 chance of developing ovarian cancer during her lifetime.
• 1 in 100 women could die of ovarian cancer.
• Ovarian cancer occurs mostly in older women.

Parasite Protein To Kill Ovarian Cancer Cells

Parasites have an innate need to not kill the host cells for their own survival sake but at the same time promote their own growth. This key factor is used to boost the body’s own immune system against cancer cells.

"Our results demonstrate that specialized effector proteins secreted by T. gondii both before and after host cell invasion trigger and coordinately control the development of a potent antitumor response.” said Dr David Bzik.

The team of scientists deleted the genes that were responsible for secreting the effector proteins to study the effect of the protein. The results of the study found that the effector proteins that were secreted during invasion of the host cell improved immune response that acted on cancer growth.

Understanding Pathways That Lead To Killing Tumor Cells

The protein secreted by the parasite increases the immune response and aids in the body fighting against ovarian tumor growth. Apart from the novel use of parasites in treating ovarian cancer, the study has opened doorways to further analysis. Adds Dr. Bzik "Consequently, tracking and understanding the host cell pathways manipulated by these T. gondii secreted effector proteins can reveal fundamental mechanisms controlling immunity to infection and can also identify relevant mammalian cell mechanisms as new targets for devising more effective therapies against highly aggressive solid tumors."

Advertisement

The mechanism of action of these proteins will aid in utilizing other similar proteins which could aid in eliciting an effective response to the growth of solid tumors.

Another Parasite Under Study

Apart from Toxoplasma gondii, there is another organism that is being studied for possible increase in the immune response against cancer. Listeria monocytogenes is a bacterium that could potentially be used to improve immune response against pancreatic cancer.

Significance of the Study

• A parasite Toxoplasma gondii found to elicit an immune response against ovarian cancer.
• Listeria monocytogenes may be another possible organism used to break immune tolerance for pancreatic cancer.
• Mechanism and pathway of action of T.gondii protein in breaking immune tolerance towards solid tumors being studied.
• Vaccine from parasites to fight cancer could be a possibility.

References:

1. What is ovarian cancer? - (http://www.cancer.org/cancer/ovariancancer/detailedguide/ovarian-cancer-key-statistics)
2. Ovarian cancer Facts - (http://www.wcrf.org/int/cancer-facts-figures/data-specific-cancers/ovarian-cancer-statistics)
3. Ovarian Cancer Statistics - (http://www.ovariancancer.org/about/statistics/)
4. Could parasite found in CAT FECES fight ovarian cancer? Scientists identify specific protein which trains the body to kill tumors - (http://www.dailymail.co.uk/health/article-3707082/Could-parasite-CAT-FECES-fight-ovarian-cancer-Scientists-identify-specific-protein-trains-body-kill-tumors.html)

Source-Medindia