Sunday, December 4, 2011

Dreaming - the Breast Cancer Vaccine

I have a dream. Well, I have many dreams, but this one is about an easy, almost painless means of ensuring that no woman ever has to face, fight or survive breast cancer again. A vaccine. Am I just dreaming? Maybe. Maybe not.

Mouse mammary tumor virus (MMTV) is a proven cause of breast cancer in field and experimental mice. MMTV was discovered way back in 1936. MMTV-like viral genetic material has been identified in human breast tumors, but it's not known whether it actually causes tumor development. Research has uncovered a human mammary tumor virus, HMTV, which is 95-98% similar to the mouse virus (MMTV), so they are believed to be the same virus.

HMTV has been found in approximately 40 percent of all human breast cancer (bc) specimens examined, in 60 percent of pregnancy-associated bc's, and in 71 percent of inflammatory bc's. Women whose tumors show evidence of the virus have antibodies to it 95 percent of the time, whereas normal, healthy women have antibodies to the virus less than 5 percent of the time.


A research team, led by Vincent Tuohy, PhD, at Cleveland Clinic's Lerner Research Institute, have developed a vaccine that prevents breast cancer tumors from forming in mice, while inhibiting the growth of existing tumors. The vaccine contains the antigen a-lactalbumin. In the latest study, genetically cancer-prone mice were vaccinated - half with a vaccine containing the antigen and half with a vaccine that didn't contain the antigen. None of the mice vaccinated with the antigen developed breast cancer, while all of the other mice did.

Unlike the FDA approved cervical cancer vaccine and liver cancer vaccines, both of which target viruses (human papillomavirus and Hepatitis B viruses), this mouse vaccine targets cancer formation itself. Tuohy explains that the key in developing a human breast cancer vaccine is therefore to find a target within the tumor that isn't typically found in a healthy person. In the case of breast cancer, they are targeting a-lactalbumin, a protein found in the majority of breast cancers but not in healthy women, except during lactation. The vaccine is expected to stimulate a woman's immune system to target a-lactalbumin, stopping tumor formation without damaging healthy breast tissue.

The hoped for strategy would be to vaccinate women over 40, when breast cancer risk begins to increase and pregnancy becomes less likely. The vaccine would also be an alternative option for younger women with a heightened risk of breast cancer, instead of prophylactic mastectomies.

While there is still controversy over just how many breast cancers contain a-lactalbumin, Tuohy is hopeful that his findings might lead to vaccines for other types of cancer, and so am I. His vaccine is ready to be tested for safety in humans, but guess what. Komen has turned him down for funding 3 times and Avon has refused to even consider it. Hmmmm.... Maybe Mr. Tuohy scared the queens of pinkwashing when he said, ""If it works in humans the way it works in mice, this will be monumental. We could eliminate breast cancer."

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