Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Protein identified that regulates effectiveness of Taxol chemotherapy in breast cancer

Cancer researchers at Georgetown University Medical Center have taken a step towards understanding how and why a widely used chemotherapy drug works in patients with breast cancer.

In laboratory studies, the researchers isolated a protein, caveolin-1, showing that in breast cancer cells this protein can enhance cell death in response to the use of Taxol, one of two taxane chemotherapy drugs used to treat advanced breast and ovarian cancer. But in order to work, they found the protein needs to be "switched on," or phosphorylated. The results were reported in the current (February 23) issue of the Journal of Biological Chemistry.

Their finding suggests it may eventually be possible to test individual breast cancer patients for the status of such molecular markers as caveolin-1 in their tumors to determine the efficacy-to-toxicity ratio for Taxol, said the study’s first author, postdoctoral fellow Ayesha Shajahan, Ph.D., of Lombardi Comprehensive Cancer Center at Georgetown.

"Because breast tumors are not all the same, it is important to know the cancer’s molecular makeup in order to increase the efficiency, and lower the toxicity, of chemotherapy drugs, and this work takes us some steps forward in this goal," she said. "It also offers insights into why some breast cancer cells can become resistant to therapeutic drugs."

... more about:
»Cancer »Caveolin-1 »Taxol »cell death »chemotherapy

Additionally, the study identifies caveolin-1 as a new molecular target for increasing the efficacy of taxanes, according to the study’s lead investigator, Robert Clarke, Ph.D., D.Sc., a Professor of Oncology and Physiology & Biophysics. "This is important because the taxanes are active drugs in breast cancer, so now that we know caveolin-1 is a new mechanism to explain how these drugs kill breast cancer cells, we can potentially take advantage of that fact to improve these agents."

The taxanes are Taxol (also known as paclitaxel) and Taxotere (docetaxel). Taxol was originally derived from the Pacific yew tree, and Taxotere is a semi-synthetic version of Taxol with slight chemical changes. These drugs stabilize a cell’s "microtubules," the road-like protein structures that send chemical signals to all parts of the cell, and which must be flexible if a cell is to divide. Taxanes lock these structures into place, not allowing them to change when the cell begins to divide - which is necessary for tumor growth. Research has also indicated that the drugs induce programmed cell death (apoptosis) in cancer cells by inactivating an "apoptosis stopping protein" called BCL2, thus stopping it from inhibiting cell death.

Caveolin-1 is a protein that is found in most cells under normal conditions and it is involved in an array of cellular events that ranges from vesicle trafficking to cell migration. It is, therefore, as a key regulator of multiple events within the cell.

In cancer, the expression level of caveolin-1 can vary depending on cell type. However, the precise role of caveolin-1 in cancer has been controversial: whether it acts as a suppressor or facilitator of tumor formation depends on the cell type. In human breast cancer, caveolin-1 has been known to act as a tumor suppressor since caveolin-1 expression is down-regulated during the primary stages of breast cancer. More recent studies indicate that that caveolin-1 expression is increased in more aggressive types of breast cancer.

Under the mentorship of Clarke, Shajahan sought to determine factors that regulate expression and function of caveolin-1 in the breast. In this study, the researchers show that in their breast cancer cell model that phosphorylated caveolin-1 increased cell death by activating other key regulators vital to both breast cancer progression and cell death, including BCL2, the same protein that Taxol works on; p21, which controls cell cycle progression; and the tumor suppressor p53.

If caveolin-1 isn’t phosphorylated, breast cancer cells appear to be resistant to Taxol treatment, the researchers conclude. "Thus, this study opens an area of investigation in our lab that will concentrate on understanding how this multi-tasking protein can serve as a marker for chemotherapeutic drug efficacy," Shajahan said.

Laura Cavender | EurekAlert!
Further information:

Further reports about: Cancer Caveolin-1 Taxol cell death chemotherapy

More articles from Life Sciences:

nachricht Gene therapy shows promise for treating Niemann-Pick disease type C1
27.10.2016 | NIH/National Human Genome Research Institute

nachricht 'Neighbor maps' reveal the genome's 3-D shape
27.10.2016 | International School of Advanced Studies (SISSA)

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

How nanoscience will improve our health and lives in the coming years

27.10.2016 | Materials Sciences

OU-led team discovers rare, newborn tri-star system using ALMA

27.10.2016 | Physics and Astronomy

'Neighbor maps' reveal the genome's 3-D shape

27.10.2016 | Life Sciences

More VideoLinks >>>