Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


New cellular flaw found in some virulent breast cancers


Overactive growth controller could become drug target

Researchers at Dana-Farber Cancer Institute have identified a molecular interaction that triggers a particularly aggressive form of breast cancer, and suggest that attacking this target with selective drugs might improve treatment.

In the January issue of Cancer Cell, a team led by Qunyan Yu, MD, and Peter Sicinski, MD, PhD, of Dana-Farber report that the interaction of a certain mutated oncogene and the newly described growth control flaw is seen in about 10 percent of breast cancers – and the deadliest ones.

The cancer results from a cascade of molecular events. The overproduction of a common protein, cyclin D1, hyperstimulates a growth switch, CDK4 kinase, causing it to unleash a virulent proliferation of cancer cells and creating a tumor with a very poor prognosis.

"The development of cancer drugs like Gleevec and Iressa have shown that it is possible to block the action of kinases," said Sicinski, "so we hope that these findings will stimulate interest in developing drugs to block CDK4 as a targeted approach to treating this very aggressive cancer."

Breast cancers composed of cells that contain both the overactive cyclin D1- CDK4 switch and a mutated cancer-causing gene ErbB-2 (also known as HER2) are extremely difficult to treat. In one recent study, the seven-year survival rate for women with this subgroup of breast cancers was only about 13 percent.

Clinicians have had some recent success in treating breast cancers with a mutated ErbB-2 gene, which are also referred to as being HER2-positive. The targeted therapy Herceptin blocks the mutation, improving the outlook for such patients, though it doesn’t work in all cases. Sicinski said that a CDK4 inhibitor might be used in combination with Herceptin to provide further benefit in these patients.

If a drug to block CDK4 proved feasible, Sicinski said, it may be possible to test women’s breast tumors for the presence of the overactive kinase, and then treat those patients with the inhibitor. "We are going to see in the next five years a movement away from treating all tumors with the same drugs, and instead match specific drugs to tumors based on their molecular characteristics," said Sicinski, who is also an associate professor of pathology at Harvard Medical School.

Cyclin D1 is one of a family of proteins that help regulate a cell’s passage through its cycle of rest and growth. Overabundance of cyclin D1 has been observed in many cancers. For a number of years, Sicinski’s laboratory has carried out a series of experiments to determine whether the protein has an important normal function, or whether it could be blocked by designer drugs to treat breast cancer without harming the patient.

Previously, mice engineered to lack cyclin D1 were found to be highly resistant to certain breast cancers, and other experiments showed that mice in which the cyclin D1 gene had been inactivated developed into more or less normal adults.

However, said Sicinski, it is difficult to design a drug to neutralize the action of a protein like cyclin D1. In the most recent experiments, the research team’s objective was to determine precisely which of cyclin D1’s several different functions was responsible for causing breast cancer.

By creating laboratory mice with different combinations of genes present or missing, the researchers were able to isolate the various cyclin D1 activities. They demonstrated that cyclin D1’s ability to activate CDK4 kinase activity is what causes the aggressive cancers, and that this same activity is required for the cancer to continue to grow.

Additional experiments reported in another Cancer Cell paper found that bioengineered mice in which cyclin D1 could not activate CDK4 kinase were developmentally normal and highly resistant to ErbB-2-caused breast cancers, demonstrating that blocking CDK4 was not harmful to the mice. That research was carried out by scientists at Tufts-New England Medical Center, Harvard Medical School, and Massachusetts Eye and Ear Infirmary, together with Sicinski.

The identification of the cyclin D1-CDK4 kinase pathway is important and could pave the way to new therapies, says Sicinski, adding that while it would be difficult to design a drug to inhibit the action of a protein like cyclin D1, blocking a kinase is significantly easier.

Bill Schaller | 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 >>>