Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Mayo Clinic identifies key cellular process in prostate and other cancers


Mayo Clinic researchers are the first to identify an interaction between two cellular proteins -- Skp2 and FOXO1 -- that is important for the growth and survival of cancer cells. Researchers also show that this interaction can be chemically reversed to stop cancer tumor growth -- a strategy that may lead to new and better cancer treatments.

Their report appears as an electronic advance article of PNAS, the Proceedings of the National Academy of Sciences ( The research was performed on human cells in the laboratory and was found effective against human cancer cells. Researchers say it will be at least a year before the discovery can be applied in a human clinical trial.

The Findings

For the first time, the Mayo Clinic research group provides laboratory evidence to describe a new mechanism by which cells lose the protection of tumor suppressors -- and therefore become vulnerable to cancerous cell growth. In particular, they show that Skp2 is the cellular player that interacts with FOXO1 by tagging it for destruction. This degradation of FOXO1 by high levels of Skp2, in turn, abolishes the ability of FOXO1 to suppress tumors. The result of their experiment indicates that human prostate cancer grows without the protection of the tumor suppressor protein FOXO1. Importantly, they also show that this loss of function can be reversed -- even in the presence of high levels of Skp2, by using chemicals that inhibit protein destruction, and thus block Skp2’s action against FOXO1.

Significance of the Finding

"The major finding of our studies is that the tumor suppression function of FOXO1 is abolished due to Skp2-mediated protein degradation," says Haojie Huang, Ph.D., the urology researcher who performed the study. Co-investigator Donald J. Tindall, Ph.D., adds, "We’ve discovered a viable therapeutic target in human cancers, especially those with high levels of Skp2."

The Mayo Clinic researchers’ findings suggest a promising new treatment target at which drug designers can aim new therapies for prostate cancer, as well as a number of other human cancers in which elevated levels of Skp2 have already been documented. These include cancers of the breast, lymphatic leukemia, small cell lung cancer and certain cancers of the mouth and colorectal cancer.

About Prostate Cancer

Prostate cancer is the second most common cause of cancer in men (skin cancer is first) and the second leading cause of cancer death in American men, exceeded only by lung cancer. In 2005, the American Cancer Society estimates 232,000 new cases will be diagnosed. While one in six men will be diagnosed with prostate cancer in his lifetime, only one in 33 will die of it. Because of the widespread disability and death that prostate cancer causes, finding new strategies to develop better treatments is an important public health goal.

Background Biology

The Mayo Clinic researchers wanted to understand the relationship between a group of proteins known as tumor suppressors that belong to the FOXO1 family, and the Skp2 protein. When tumor suppressors fail, the result is abnormal cell growth that can eventually transform healthy cells into cancerous cells. In particular, the Mayo Clinic team wanted to find out what disables FOXO1 tumor suppressor, and how it works -- in hopes of reversing the process to find a new cancer therapy strategy.

The Experiment

The Mayo Clinic research team knew from previous research:

  • FOXO1 possesses tumor suppressor functions. Its tumor suppression works two ways: by curbing cell reproduction and by inducing cells to kill themselves -- especially cancer cells.
  • Some tumor suppressors lose their effectiveness through a means known as the "ubiquitin pathway." This pathway is a cellular strategy for attaching an identifying marker to the tumor suppressor that targets it for destruction.
  • Skp2 is known to target several tumor suppressors for destruction.
  • FOXO1 is suited to being targeted for destruction via the ubiquitin pathway.

The researchers noted that high levels of Skp2 were associated with low levels of FOXO1 in many human cancer cells, including prostate cancer -- and then combined the lines of evidence outlined above to design experiments to answer the specific question: Do elevated levels of Skp2 drive down and disable FOXO1, thus resulting in loss of its tumor suppression ability? The answer is yes.

Robert Nellis | EurekAlert!
Further information:

More articles from Life Sciences:

nachricht First time-lapse footage of cell activity during limb regeneration
25.10.2016 | eLife

nachricht Phenotype at the push of a button
25.10.2016 | Institut für Pflanzenbiochemie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Ice shelf vibrations cause unusual waves in Antarctic atmosphere

25.10.2016 | Earth Sciences

Fluorescent holography: Upending the world of biological imaging

25.10.2016 | Power and Electrical Engineering

Etching Microstructures with Lasers

25.10.2016 | Process Engineering

More VideoLinks >>>