Navigation Links
Discovery that PARP protein exists in all breast tumors will help target chemo and predict response
Date:3/26/2010

This press release is available in Spanish.

Barcelona, Spain: The presence of the protein poly (ADP-ribose) polymerase (PARP) in tumours can help predict their response to chemotherapy, a German scientist will tell the seventh European Breast Cancer Conference (EBCC7) in Barcelona tomorrow (Saturday 27 March). Professor Gunter von Minckwitz, from the German Breast Group Forschungs GmBH, Neu-Isenburg, says that, contrary to current belief that PARP is associated with a limited number of tumours, he and his team found for the first time that PARP expression exists across all breast cancer subtypes, and that such tumours were highly sensitive to chemotherapy.

Professor von Minckwitz and his team set out to investigate the expression of PARP in various hormone receptor subtypes of early breast cancer and to evaluate whether or not it could predict a total response to chemotherapy given before surgery. "We knew that a new class of drug called PARP inhibitors were effective against aggressive types of breast cancer such as those involving BRCA mutations and triple-negative breast cancer, where the tumour does not express genes for the oestrogen or progesterone receptors, or for HER2," he says. "However, we didn't understand whether the presence of PARP would predict the efficacy of these drugs. Before exploring this, we needed to understand whether PARP played any role in breast cancers, whether it was restricted to particular types of tumours, how it correlated to existing prognostic and predictive markers, and whether it could predict the efficacy of chemotherapy."

PARP is a protein involved in a number of cellular processes. One of its important functions is assisting in the repair of single-strand DNA breaks. If one single-strand broken DNA is reduplicated, a double-strand broken DNA results. If PARP is inhibited, cell death occurs; this means that chemotherapy can be targeted precisely at cancer cells, while leaving normal, healthy cells relatively untouched. A recent conference presentation* showed that the simultaneous use of a PARP inhibitor with DNA-damaging chemotherapy in breast cancer could improve overall survival. The potential role of PARP inhibitors as a new anticancer agent is currently under research in a number of other studies.

Professor von Minckwitz's team used tissue from 646 patients in a neoadjuvant Phase III trial (GeparTrio) to look for the presence of PARP and to correlate its existence with other prognostic factors and total response to chemotherapy. Neoadjuvant chemotherapy is given to patients before other treatments such as surgery or radiotherapy. They found that, although PARP was present in all tumour subtypes, it occurred most frequently in HER2 positive and triple negative tumours, and that it correlated with most known prognostic factors, except HER2.

"The relationship to total response was remarkable," says Professor von Minckwitz. "Tumours with a high level of PARP expression had a total response in 26% of cases, whereas those tumours which did not express PARP had a total response in only 9%. Additionally, we found that the presence of PARP can provide more accurate prognostic information than the grade of differentiation or degree of abnormality of tumours. We believe that this is the first study to describe a broad expression of PARP in untreated breast tumours together with a correlation of sensitivity to chemotherapy."

PARP positive tumours could become a new entity in breast cancer, the investigators say. They intend to follow up their initial findings by a trial randomising patients to either chemotherapy alone or chemotherapy plus a PARP inhibitor. "Particularly in triple-negative tumours there is a great need to improve treatment options," says Professor von Minckwitz. "Apart from chemotherapy, there is no other treatment such as endocrine or anti-HER2 therapy available for this aggressive form of breast cancer."

However, it remains to be seen whether immunohistochemical detection (the process of localising antigens in tissue cells) of PARP is the best method of predicting PARP inhibitor efficacy, the scientists say. "We need more prospective trials to be sure that there is no better way of making sure that the right people are getting the right therapy," says Professor von Minckwitz. "However, it would be fair to say that we believe that we may be on the verge of a major change in the way breast cancer is treated."


'/>"/>

Contact: Mary Rice
mary@mrcommunication.org
ECCO-the European CanCer Organisation
Source:Eurekalert

Related biology news :

1. Chance discovery leads to plant breeding breakthrough
2. A-maize-ing discovery could lead to higher corn yields for food, feed and fuel
3. African bird discovery proves there is something new under the sun
4. Discovery in legumes could reduce fertilizer use, aid environment: Stanford researchers
5. Startup joins UCLA tech incubator to develop technologies for drug discovery, screening
6. An electrifying discovery: New material to harvest electricity from body movements
7. New gene discovery could help to prevent blindness
8. First discovery of the female sex hormone progesterone in a plant
9. Enlisting a drug discovery technique in the battle against global warming
10. TGen becomes center of excellence for Horizon Discoverys GENESIS and X-MAN technology
11. Gene function discovery: Guilt by association
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/2/2016)... 2016 The Department of Transport Management ... 44 million US Dollar project, for the , ... Personalization, Enrolment, and IT Infrastructure , to ... and implementation of Identity Management Solutions. Numerous renowned international vendors ... Decatur was selected for the most compliant and ...
(Date:5/20/2016)...  VoiceIt is excited to announce its new ... By working together, VoiceIt and VoicePass will offer ... take slightly different approaches to voice biometrics, collaboration ... usability. Both ... "This marketing and technology partnership allows ...
(Date:4/28/2016)... BANGALORE, India , April 28, 2016 /PRNewswire/ ... product subsidiary of Infosys (NYSE: INFY ), and ... global partnership that will provide end customers with ... banking and payment services.      (Logo: http://photos.prnewswire.com/prnh/20130122/589162 ... area for financial services, but it also plays a fundamental ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... , June 23, 2016 On Wednesday, ... at 4,833.32, down 0.22%; the Dow Jones Industrial Average edged ... closed at 2,085.45, down 0.17%. Stock-Callers.com has initiated coverage on ... ), Nektar Therapeutics (NASDAQ: NKTR ), Aralez Pharmaceuticals ... (NASDAQ: BIND ). Learn more about these stocks ...
(Date:6/23/2016)... ... June 23, 2016 , ... Regulatory Compliance Associates® ... provides a free webinar on Performing Quality Investigations: Getting to Root ... CT at no charge. , Incomplete investigations are still a major concern to ...
(Date:6/23/2016)... -- Amgen (NASDAQ: AMGN ) today announced a ... sciences incubator to accelerate the development of new therapies ... QB3@953 was created to help high-potential life science and ... stage organizations - access to laboratory infrastructure. ... "Amgen Golden Ticket" awards, providing each winner with one ...
(Date:6/22/2016)... SAN DIEGO , June 22, 2016 /PRNewswire/ ... partnership that will allow them to produce up ... (HiPSC) from one lot within one week. These ... their time laboriously preparing cells and spend more ... made possible through a proprietary, high-volume manufacturing process ...
Breaking Biology Technology: