Scientists discover how rapamycin slows cell growth

May 23, 2013

University of Montreal researchers have discovered a novel molecular mechanism that can potentially slow the progression of some cancers and other diseases of abnormal growth. In the May 23 edition of the prestigious journal Cell, scientists from the University of Montreal explain how they found that the anti-cancer and anti-proliferative drug rapamycin slows down or prevents cells from dividing.

"Cells normally monitor the availability of nutrients and will slow down or accelerate their growth and division accordingly. A key monitor of nutrients is a protein called the Target of Rapamycin (TOR), but we do not know the details of how this protein feeds signals downstream to control growth says Dr. Stephen Michnick, senior author and a University of Montreal biochemistry professor. He adds that, "we were surprised to find that TOR hooks up to a circuit that controls the exit of cells from division which in turn modulates the message that codes for a key cell cycle regulator called B-cyclin".

In collaboration with Daniel Zenklusen, also a University of Montreal biochemistry professor and lead author and Vincent Messier, discovered that when cells are starved for nutrients TOR sends a signal to shut down production of a chemical message in the form of RNA to synthesize B cyclin ", Dr. Michnick explained. "We also found that TOR acts through a previously unforeseen intermediary, a protein that makes small chemical modifications to proteins normally stabilize B cyclin ", he added. "We have known that starvation and a drug that mimics starvation, rapamycin, affects B cyclin synthesis, but we didn't know how. Our studies now point to one mechanism", noted Dr. Messier.

Dr. Zenklusen emphasized that, "this is an important finding with implications for our understanding on how the normal organism interprets its environment to control growth and it was a surprise to find a mechanism that works through the RNA that codes for a . Dr. Michnick adds, " is a promising therapy for some cancers and other devastating maladies such as the rare lung disease called lymphangioleiomyomatosis (LAM). It remains to be seen whether the pathway we have discovered might be an alternative target for the development of therapeutics against these diseases."

Explore further: 'Office life' of bacteria may be their weak spot

More information: www.sciencedirect.com/science/… ii/S0092867413005114

add to favorites email to friend print save as pdf

Related Stories

Cancer protein discovery may aid radiation therapy

Jun 09, 2011

Scientists at Dana-Farber Cancer Institute have uncovered a new role for a key cancer protein, a finding that could pave the way for more-effective radiation treatment of a variety of tumors.

Scientists find protein critical for tissue regeneration

Mar 20, 2012

A flatworm known for its ability to regenerate cells is shedding more light on how cancer could be treated and how regenerative medicine could better target diseases, according to researchers at the University ...

Recommended for you

Healthy humans make nice homes for viruses

Sep 16, 2014

The same viruses that make us sick can take up residence in and on the human body without provoking a sneeze, cough or other troublesome symptom, according to new research at Washington University School ...

Unraveling cell division

Sep 16, 2014

CRG researchers shed new light on mitosis. The study published in the Journal of Cell Biology describes how Topo 2 disentangles DNA molecules and is essential for proper cell division

User comments : 0