Biologists at UC San Diego have succeeded in genetically engineering algae to produce a complex and expensive human therapeutic drug used to treat cancer.
The advance is the culmination of seven years of work to demonstrate that Chlamydomonas reinhardtii, a green alga used widely in biology laboratories as a genetic model organism can produce a wide range of human therapeutic proteins in greater quantity and more cheaply than bacteria or mammalian cells. Bacteria cannot make these drugs since they are incapable of folding the proteins into the complex, three-dimensional shapes needed. Additionally, the drug cannot be made in mammalian cells as the toxin would kill them.
The engineered algae produces a complex, three-dimensional protein with two “domains” — one of which contains the antibody to target cancer cells and another containing a toxin that kills the bound cancer cells. Such “fusion proteins” are presently created by pharmaceutical companies in a complex, two-step process by first developing the antibody domain in a Chinese hamster cell. The antibody is purified, then chemically attached to a toxin outside of the cell after which the final protein is re-purified.
While producing this particular fusion protein in algae was fairly straightforward because it involved fusing two domains, this same method can likely be used in the future to engineer algae to produce more complex proteins with multiple domains. Read more here: