Proliferation protein goes rogue in lung cancer
Rac1b could be treatment target
By Nathan Seppa
A defective protein might be a key go-between in the string of terrible molecular events that lead to lung cancer. The protein, called Rac1b, gets activated by other compounds and launches cells in smokers’ lungs toward malignant behavior, experiments in human cells and mice suggest.
The findings open the door for lung cancer researchers to investigate the molecular chain reaction, or pathway, in which Rac1b is involved. Since Rac1b seems to show up early in lung cancer, it might also make a target for diagnosis or early-stage treatment, researchers report in the July 11 Science Translational Medicine.
“This is really comprehensive work,” says Farrah Kheradmand, a pulmonologist at Baylor College of Medicine in Houston, who wasn’t part of the study team. “This gives us ammunition to go after Rac1b, an inconspicuous molecule, to try to inhibit it.”
Rac1b is a variant of Rac1, a protein involved in cell proliferation. But while the gene that encodes Rac1 routinely turns itself off after producing its protein, the variant gene making Rac1b doesn’t. “It’s not meant to be on all the time,” says study coauthor Derek Radisky, a cell biologist at the Mayo Clinic in Jacksonville, Fla. So the aberrant version of the protein gets made in excess.