NEW YORK, Jan 27 (Reuters Health) -- Scientists have developed a way to speed up the production of a cancer-fighting enzyme called epothilone in bacteria. By making it easier to make the enzyme, the achievement should pave the way for new cancer treatments, researchers report, assuming it proves to be safe and effective in clinical trials.
Various forms of epothilones have been considered as possible alternatives to the anticancer drug Taxol, since they fight tumors in much the same way, according to Dr. Li Tang and colleagues at KOSAN Biosciences in Hayward, California. Taxol is approved to treat several types of cancer, including lung cancer and advanced ovarian cancer, as well as breast cancer in combination with another drug. But unlike Taxol, which does not dissolve easily in water and has to given with an additive that can cause serious side effects, epothilone is highly water soluble. Also, the enzyme has been shown to fight tumors that have become resistant to Taxol.
Producing epothilone has not made economic sense, however, since it grows very slowly and in small numbers in the bacterium where it is naturally found, the researchers note in the January 28th issue of the journal Science.
But Tang's team has found a quicker way to grow the enzyme. After cloning the epothilone gene, the researchers placed it in another bacterium, which produced the enzyme 10 times faster. In addition, this bacterium is better understood, meaning that scientists should be able to manipulate it to grow the types of epothilones that have the most cancer-fighting power.
In an interview with Reuters Health, Dr. Daniel V. Santi, the chief executive
officer of KOSAN, said the company hopes to produce enough of the enzyme to
begin clinical trials within the next year or two. He noted that animal tests
conducted by other teams have produced promising results.
SOURCE: Science 2000;287:640-642.