Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientists discover way to block growth of prostate cancer cells

09.11.2006
Scientists have discovered for the first time a specific biochemical pathway by which the sex hormone, androgen, increases levels of harmful chemicals called reactive oxygen species (ROS) in the prostate gland that play a role in the development of prostate cancer.

They found that a drug that blocks this pathway significantly prolonged survival and inhibited tumour development in mice that were genetically engineered to spontaneously develop prostate cancer and die of the disease. The hope is that this drug could be used eventually to treat men at high risk of developing prostate cancer and to prevent recurrences in men already treated for primary tumours.

Dr Hirak Basu told a news briefing at the EORTC-NCI-AACR [1] Symposium on Molecular Targets and Cancer Therapeutics in Prague today (Wednesday 8 November): “Previous work has demonstrated that androgen treatment increased reactive oxygen species levels in androgen-dependent prostate cancer cells, but, until now, the pathway involved was unknown.”

Dr Basu is an associate scientist and principal investigator in the Prostate Cancer Group at the Paul P. Carbone Comprehensive Cancer Center, Madison, WI, USA. He and his collaborators at the centre found that levels of a key enzyme, spermidine/spermine acetyl transferase (SSAT), which starts oxidation of polyamines, rose markedly when prostate cancer cells were treated with androgen. Polyamines are small molecules produced in large quantity by the prostate gland and are secreted in the seminal fluid. Oxidation of polyamines generates a large amount of the ROS, hydrogen peroxide. Peroxide causes oxidative stress, a condition in which cells produce an excess of oxygen-free radicals, which are known to play a key role in cell signalling and prostate cancer development.

“These results demonstrate that polyamine oxidation is one of the major causes of androgen-induced oxidative stress in prostate cancer cells,” said Dr Basu. “The discovery of this pathway is a major step forward in understanding the role of androgen in prostate cancer development.

“Many scientists in the polyamine field have worked towards increasing, rather than decreasing, oxidative stress in order to destroy established tumours. However, no one that I know has tried to reduce oxidative stress by blocking polyamine oxidation to prevent prostate tumours, and this is what we set out to do.”

Having discovered the role played by polyamine oxidation, the researchers with the help of their collaborators at Wayne State University, Detroit, MI, USA, synthesised a molecule called MDL 72,527 (MDL), which was previously known to be an inhibitor of acetyl polyamine oxidase (APAO). APAO catalyses the oxidation of acetyl polyamines produced by SSAT – the process that results in the generation of ROS. MDL can, therefore, block androgen-induced ROS production in prostate cancer cells.

They injected MDL into the genetically engineered mice and found that it inhibited polyamine oxidation and reduced oxidative stress in the prostate glands of the animals. The treatment significantly increased overall survival and delayed time to prostate tumour development. In repeat experiments, between 50-60% of mice treated with MDL survived ten to twelve weeks longer than the untreated control group.

“To the best of our knowledge, this is the first report of a specific enzyme inhibitor MDL that blocks androgen-induced oxidative stress in the prostate and prevents spontaneous prostate tumour development,” said Dr Basu.

More tests have to be carried out, but the researchers, working with the world-renowned prostate cancer clinician Dr George Wilding (a co-author of the paper), hope that phase I clinical trials of MDL might be able to start in 12-18 months.

Dr Basu said: “After surgery and radiotherapy for the primary tumour, breast cancer patients can be treated with several drugs such as tamoxifen and aromatase inhibitors that prevent or delay breast cancer recurrence. No such treatment exists for prostate cancer patients. After treatment of their primary tumours, prostate cancer in men is managed by watchful observation only. The immediate goal of our research is to develop agents such as MDL to fill this unmet medical need. If MDL, or any of the other agents that we are working with, can be expanded further to treat all high-risk men, we will be delighted.”

[1]EORTC [European Organisation for Research and Treatment of Cancer, NCI [National Cancer Institute], AACR [American Association for Cancer Research].

Emma Mason | alfa
Further information:
http://www.eortc.org

Further reports about: Androgen Basu MdL Oxidation Oxidative ROS oxidative stress polyamine prostate prostate cancer tumour

More articles from Life Sciences:

nachricht A Map of the Cell’s Power Station
18.08.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

nachricht On the way to developing a new active ingredient against chronic infections
18.08.2017 | Deutsches Zentrum für Infektionsforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

Engineering team images tiny quasicrystals as they form

18.08.2017 | Physics and Astronomy

Researchers printed graphene-like materials with inkjet

18.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>