A new gene has been identified by biologists at the Florida State University (FSU) in collaboration with colleagues at the University College London (UCL). The gene, named Mahjong after the popular Chinese tile game, was found to be the only one that can help the good guys in the life or death 'cell competition' between healthy and cancerous cells.
Mahjong-defective cells (labelled by green) are out-competed by the adjacent normal cells and undergo programmed cell death (labelled by red) both in fruit fly's larval epithelia (left panel) and mammalian cultured epithelial cells (right panel).: image courtesy of Yoichiro Tamori via RDMag.com
Lead scientists Yoichiro Tamori (FSU), Wu-Min Deng (FSU), and Yasuyuki Fujita (UCL) started out by researching the tumor suppressor gene "Lethal giant larvae" (Lgl), which was known to bond with uncertain proteins to protect the epithelia of healthy cells. In the death of healthy cells, it was seen that mutations in Lgl would cause these cells to lose the cell competition. But why did other healthy cells stay strong and survive?
Mahjong, it turns out, is the answer, and the scientists found that it is the only protein that binds to Lgl to successfully compete. The two genes, working together, bind in both fruit flies and mammals,but their relative contribution to keeping the cells alive differs.
Whereas Mahjong can compensate for a mutant Lgl gene in a cell, Lgl cannot compensate for a cell that contains mutant Mahjong. In fact, when mutant Mahjong is present in a cell, that cell dies, even when it is surrounded by healthy cells.
learned that overexpressing Mahjong in Lgl-deficient cells, which
typically self destruct, did in fact prevent apoptosis," Deng said.
"But, in contrast, we found that overexpressing Lgl in Mahjong-deficient
cells did not prevent cell suicide."
This fascinating study and the identification of a new gene is a invaluable contribution to future cancer therapies. The scientists have already found that Mahjong does not do well with tetracycline, by the way.
Plos Biology via R&D Mag