HPV Researcher Gets Nobel Prize
In October 2008, the Nobel Assembly at Karolinska Institutet announced its decision to award the Nobel Prize in Physiology, or Medicine, to three researchers; Harald zur Hausen, for his work in discovering that human papilloma viruses (HPV) cause cervical cancer, and Francoise Barre-Sinoussi and Luc Montagnier for discovering the human immunodeficiency virus (HIV). The Nobel assembly chose to award these researchers for their discoveries of two viruses that are responsible for causing severe disease in humans.
Harald zur Hausen MD was born in 1936 in Germany. He is on the medical staff of the University of Düsseldorf in Germany. Zur Hausen is also Professor emeritus and former Chairman and Scientific Director for the German Cancer Research Centre in Heidelberg, Germany.
Zur Hausen's hypothesis, which won him the Nobel Prize, ran counter to current theory in stating that the oncogenic human papilloma virus caused cervical cancer, the second most common cancer in women. The researcher understood that HPV DNA could be found in an inactive state in the tumors and might be seen in a specific search for viral DNA.
The German researcher found that HPV is a mixed group of viruses and that only some of them cause cancer. This discovery has led to the ability to piece together the history of HPV infection, an understanding of how HPV can cause cancer, and to the development of the Gardasil vaccine against HPV.
Against Prevailing Philosophy
In the 1970's, against prevailing medical philosophy, Harald zur Hausen first set forth his theory that the human papilloma virus was implicated in cervical cancer. His hypothesis stated that tumor cells, should they be possessed of an oncogenic (cancerous) virus, would have viral DNA as part of their genomes. He believed that the HPV genes responsible for cell proliferation could be detected in a search for this specific viral DNA.
Zur Hausen worked on proving his hypothesis for 10 years by searching for various types of HPV. His work was complicated by the fact that only segments of the viral DNA were integrated into the host genome. The earnest researcher discovered HPV DNA in the biopsies of cervical cancer victims and in 1983 found something new: tumorigenic HPV16. The following year, zur Hausen was able to clone HPV16 and 18 from cervical cancer patients. Thereafter, it was found that these two HPV types could be found in some 70% of all cervical cancer biopsies conducted worldwide.
Over 5% of all cancers, all over the world, can be attributed to the HPV virus. This is the most common of all sexually transmitted agents and afflicts from 50-80% of the world population. There are more than 100 known HPV types but only about 40 of them infect the genital tract. Of these 40, 15 virus types put women in the high risk category for cervical cancer. The HPV virus is also implicated in oral, vulval, penile, and other cancers. HPV can be found in 99.7% of those women who have a histological confirmation of cervical cancer, representing some 500,000 women every year.
Thanks to zur Hausen, we now understand how HPV serves to induce cancer. Zur Hausen made HPV16 and 18 available to those in the scientific community and, as a result, the Gardasil vaccine was created. The vaccine gives greater than 95% protection from these cancer-causing virus types and also reduces the need for surgery and cancer treatments.