New study reveals a protein that keeps people—and their skeletons—organized

November 14, 2013 by Cristy Lytal
This is a mouse femur with an enchondroma-like structure. Credit: Lick Lai

Most people think that their planners or their iPhones keep them organized, when proteins such as liver kinase b1 (Lkb1) actually have a lot more to do with it. New research from postdoctoral fellow Lick Lai in the lab of USC scientist Andy McMahon published in Proceedings of the National Academy of Sciences (PNAS) sheds light on how this important protein keeps people organized on a basic level by promoting orderly skeletal growth and preventing skeletal tumors.

In a developing embryo, many bones form based on cartilage templates. The study found that to form these templates, Lkb1 protein controls the progression of immature, dividing into larger, mature and fully differentiated cartilage cells. Without Lkb1, the population of immature cartilage cells disproportionately increases, leading to skeletal tumors.

The way that Lkb1 controls the differentiation of cartilage cells is by suppressing what's known as the "mammalian target of rapamycin (mTOR) pathway"—a very important complex of molecules that coordinates growth in response to available nutrients and other factors. Problems with the mTOR pathway have been implicated in a host of human diseases, including diabetes, obesity, depression and many cancers.

The influence of abnormal Lkb1 isn't restricted to the skeleton, however. Mutant forms of Lkb1 are frequently present in patients with lung, cervical, breast, intestinal, testicular, pancreatic and skin cancers, and in patients with the Peutz–Jeghers syndrome, characterized by benign polyps in the gastrointestinal tract.

"By understanding Lkb1 and the mechanisms that control normal skeletal development, we also learn how we might prevent this development from going awry in cancers and other disorders," said McMahon, who directs the USC Stem Cell initiative and the Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research at USC.

Explore further: Oncogene inhibits tumor suppressor to promote cancer: Study links B-RAF and LKB1

More information: www.pnas.org/content/early/2013/11/07/1309001110.abstract

Related Stories

Hungry cells

June 16, 2009

People who suffer from Peutz-Jeghers syndrome, a rare inherited cancer syndrome, develop gastrointestinal polyps and are predisposed to colon cancer and other tumor types. Carefully tracing the cellular chain-of-command that ...

Gene inactivation drives spread of melanoma: study

June 11, 2012

Why do some cancers spread rapidly to other organs and others don't metastasize? A team of UNC researchers led by Norman Sharpless, MD, have identified a key genetic switch that determines whether melanoma, a lethal skin ...

Study finds new drug target for metastatic breast cancer

April 11, 2013

Research led by Dr. Suresh Alahari, Professor of Biochemistry and Molecular Biology at LSU Health Sciences Center New Orleans, is the first to report that two specific tumor suppressor genes work in concert to inhibit the ...

Recommended for you

Basic research fuels advanced discovery

August 26, 2016

Clinical trials and translational medicine have certainly given people hope and rapid pathways to cures for some of mankind's most troublesome diseases, but now is not the time to overlook the power of basic research, says ...

New method creates endless supply of kidney precursor cells

August 25, 2016

Salk Institute scientists have discovered the holy grail of endless youthfulness—at least when it comes to one type of human kidney precursor cell. Previous attempts to maintain cultures of the so-called nephron progenitor ...

New avenue for understanding cause of common diseases

August 25, 2016

A ground-breaking Auckland study could lead to discoveries about many common diseases such as diabetes, cancer and dementia. The new finding could also illuminate the broader role of the enigmatic mitochondria in human development.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.