Brad Pitt and fruit flies have very little in common – after all, it’s unlikely you’ll go to see a Hollywood film that starred the latter. However, as a new study in the journal Scientific Reports reveals, there is one characteristic that they definitely do share, and bizarrely, it’s all to do with his hairstyle.
In several films, the venerable movie star sports a cowlick hairstyle, where individual hairs grow in the opposite direction from the rest and droop down over the forehead. As it turns out, this hairstyle is only possible with the help of so-called “polarity genes.”
These genes help direct nutrient flow across cells and help cells join up and support each other. They also cause certain biological structures to form opposing or “polarized” patterns, including in human hair which can, in some instances, lead to the cowlick.
Polarity genes also happen to specify where the front and rear ends of cells are, without which the cells will not be able to migrate from one place to another. This polarity is abandoned when cancer cells move around the body during metastasis, at which point the affliction becomes incredibly difficult to treat.
By carefully examining the processes controlling polarity genes in the common fruit fly group Drosophila, a team of researchers at Michigan State University (MSU) has uncovered what organizes and governs these polarity genes. Curiously, it’s a protein that normally suppresses tumors called retinoblastomas, a cancer that typically spreads in the eyes of young children.
A control fruit fly’s bristles (left) compared to an experimental fruit fly (right) without the polarity gene-controlling protein. Payankaulam et al./Scientific Reports
This suppressor protein is part of a large family of cellular guardians that control cell reproduction, DNA repair, and cellular self-destruction, all of which are important cancer-fighting tools. The researchers removed this retinoblastoma suppressor protein from their fruit flies and watched as they took on an “unkempt” appearance, developing poorly-oriented wing hair, indicating that it also controls the expression of polarity genes as well as having anti-cancer functionality.
The high degree of genetic similarity between fruit flies and humans means that this protein probably plays a similar role in humans. If this is confirmed, it could lead to a range of new chemotherapy treatments that aim to restore this protein’s anti-cancer role that it otherwise may have lost.
“Until now, people neglected the regulation of polarity genes, thinking them to be regulated in a rather humdrum manner similar to ‘housekeeping’ genes that are devoted to basic cellular functions,” David Arnosti, a professor of biochemistry at MSU and contributing author of the study, said in a statement. “Our work challenges this view and raises an important question relevant to development of new cancer diagnosis and therapies.”