Tobacco May Cure Cancer?

The solution to a common type of cancer may come from an unlikely hero—tobacco. Researchers at Stanford University recently found that plant-generated vaccines may be a safe, fast, and economic way to fight cancer in patients with follicular B-cell lymphoma.

A July 21 online edition of the Proceedings of the National Academy of Sciencesreported that a tobacco plant’s viral expression system “allowed rapid production and recovery of idiotypic single-chain antibodies (scFv) derived from each patient's tumor and immunization of patients with their own individual therapeutic antigen.”

Tests found that in 70% of patients, the vaccine generated a general immune response, and in 47% of patients, that response was antigen-specific. The findings suggest that plant-generated therapies may be the key to developing coveted, personalized vaccines. The vaccine showed not a preventative but direct response targeting malignant cells and stimulating the immune system to respond to specific cancer-antibodies. This success suggests the new technique may be a way to aggressively attack malignant lymphoma cells earlier in a patient’s diagnosis.

The vaccine demonstrated additional advantages to safety and cost. All participants experienced zero negative side effects from low dose, high dose, or combined intervention treatments. The authors also report that plant-generated vaccines eliminate risk of unintended infection from an animal virus or other bacteria. In addition, because the genetically engineered plants can rapidly produce the vaccines and only a few leaves are needed to produce a full vaccine for one patient, it is an inexpensive alternative.

Senior author of the study, Robert Levy, MD, noted these advantages and conveyed that there is reason to believe the plant-grown antibodies will elicit stronger immune responses than animal-grown antibodies because of differences in the sugars manufactured by plants and animals.

The phase-I study was the first human test of injectable vaccines grown in genetically engineered plants. Phase-II effectiveness studies will soon follow.

What will be the impact of these findings? Will tobacco, stigmatized for its association with lung and other cancers, influence patient or physician reception? Will plant-generated vaccines become standard treatment? When?