It sounds like a variation of the movie WORLD WAR Z, but scientists are successfully using viruses to kill cancer cells.
In 1904 a woman in Italy confronted two life-threatening events: first, diagnosis with cancer of the uterine cervix, then a dog bite. Doctors delivered the rabies vaccine for the bite, and subsequently her “enormously large” tumor disappeared (“il tumore non esisteva più”). The woman lived cancer-free until 1912. Soon thereafter several other Italian patients with cervical cancer also received the vaccine—a live rabies virus that had been weakened. As reported by Nicola De Pace in 1910, tumors in some patients shrank, presumably because the virus somehow killed the cancer. All eventually relapsed and died, however.
Even though the patients perished, the notion of treating cancer with viruses able to kill malignant cells—now termed oncolytic virotherapy—was born. And investigators had some success in laboratory animals. Yet for a long time only partial responses and rare cures in human trials ensured that the field stayed at the fringes of cancer research. Viral therapy for cancer faced several additional hurdles: uncertainty about its mechanisms and how to use viruses to achieve cures, a dearth of tools with which to engineer more effective viral strains and the habitual reluctance of physicians to infect patients with pathogens. Doctors elected to use poisons (chemotherapy) instead of microbes—mostly because they were more comfortable with those drugs and understood them better.
Even though the patients perished, the notion of treating cancer with viruses able to kill malignant cells—now termed oncolytic virotherapy—was born. And investigators had some success in laboratory animals. Yet for a long time only partial responses and rare cures in human trials ensured that the field stayed at the fringes of cancer research. Viral therapy for cancer faced several additional hurdles: uncertainty about its mechanisms and how to use viruses to achieve cures, a dearth of tools with which to engineer more effective viral strains and the habitual reluctance of physicians to infect patients with pathogens. Doctors elected to use poisons (chemotherapy) instead of microbes—mostly because they were more comfortable with those drugs and understood them better.
Mayo Clinic is targeting cancer on the molecular level - by changing the genetic makeup of diseased cells. Gene therapy changes the DNA of cancer cells so that they die, while virus therapy uses the destructive power of viruses to kill cancer cells. "Viruses are professional gene delivery vehicles," said Dr. Stephen Russell, leader of the Gene and Virus Therapy Program of the Mayo Clinic Cancer Center. "We're now able to harness that."
The program has used several unique research techniques to study gene and virus therapy in the treatment of cancer, and is conducting clinical trials to test the therapy's effectiveness in humans.
The findings are published today in the Journal of Clinical Oncology. Also look for the VICE Special Report: Killing Cancer
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