Navigation Links
Experimental drug shows promise against brain, prostate cancers
Date:1/3/2010

DALLAS Jan. 4, 2010 An experimental drug currently being tested against breast and lung cancer shows promise in fighting the brain cancer glioblastoma and prostate cancer, researchers at UT Southwestern Medical Center have found in two preclinical studies.

The drug's actions, observed in isolated human cells in one trial and in rodents in the other, are especially encouraging because they attacked not only the bulk of the tumor cells but also the rare cancer stem cells that are believed to be responsible for most of a cancer's growth, said Dr. Jerry Shay, professor of cell biology and a senior co-author of both papers. The glioblastoma study appears in the January issue of Clinical Cancer Research. The prostate cancer study is available online in the International Journal of Cancer.

In the glioblastoma study, performed in mice, the drug also crossed from the bloodstream into the brain, which is especially important because many drugs are not able to cross the blood-brain barrier.

"Because it attacks a mechanism that's active in most cancers, it might prove to be widely useful, especially when combined with other therapies," said Dr. Shay.

Dr. Shay and his colleagues study telomeres, bits of DNA that help control how many times a cell divides. Telomeres are protective "caps" of DNA on the ends of chromosomes, the structures that contain the body's genes. As long as telomeres are longer than a certain minimum length, a cell can keep dividing. But telomeres shorten with each cell division, so a cell stops dividing once the telomeres are whittled down to that minimum.

In cancer cells, however, an enzyme called telomerase keeps rebuilding the telomeres, so the cell never receives the cue to stop dividing. In essence, they become immortal, dividing endlessly.

The drug used in these studies (imetelstat or GRN163L) blocks telomerase. It is already in clinical trials as a potential treatment for breast and lung cancer, as well as for chronic lymphocytic leukemia.

Glioblastomas are the most common malignant brain tumors in adults, according to the American Cancer Society. They are difficult to treat with drugs because blood vessels in the brain have tightly constructed walls that allow only a few substances to pass through.

The researcher focused on cells called tumor-initiating cells. Some researchers believe that tumors contain a small subset of initiating cells or cancer stem cells that are able to initiate and drive tumors and that are often resistant to radiation therapy and chemotherapy.

In the glioblastoma study, Dr. Shay and his colleagues found that imetelstat blocked the action of telomerase in isolated tumor-initiating cells as well as the bulk of the tumor cells, eventually killing the cells. Combining imetelstat with radiation and a standard chemotherapy drug made imetelstat even more effective. When the researchers implanted human tumor-initiating cells into rodents, they found that imetelstat was able to enter brain tissue and inhibit telomerase activity.

In the prostate cancer study, the researchers isolated tumor-initiating cells from human prostate cancer cells. The cells showed significant telomerase activity. Imetelstat blocked the enzyme's activity, and telomeres shortened greatly.


'/>"/>

Contact: Aline McKenzie
aline.mckenzie@utsouthwestern.edu
214-648-3404
UT Southwestern Medical Center
Source:Eurekalert

Related biology news :

1. Experimental Biology 2008 meets in San Diego April 5-9
2. Translational research patented first experimental treatment against idiopathic pulmonary fibrosis
3. Experimental Biology and Medicine announces expansion into Asia, opens new office
4. Experimental chemotherapy regimen shows promise in treating advanced lung cancer
5. French scientist wins the Journal of Experimental Biology Outstanding Paper Prize
6. Survival in a Changing World: The Journal of Experimental Biology 2009 symposium
7. 40 minority scientists receive travel fellowships to Experimental Biology 2009 in New Orleans
8. Experimental treatment halts hypoxic-ischemic brain injury in newborns
9. Experimental treatments restore partial vision to blind people
10. French scientist wins the Journal of Experimental Biology Outstanding Paper Prize 2009
11. Research shows skeleton to be endocrine organ
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/15/2016)... DUBLIN , April 15, 2016 ... of the,  "Global Gait Biometrics Market 2016-2020,"  report ... http://photos.prnewswire.com/prnh/20160330/349511LOGO ) , ,The global gait ... CAGR of 13.98% during the period 2016-2020. ... movement angles, which can be used to compute ...
(Date:4/13/2016)... -- IMPOWER physicians supporting Medicaid patients in Central ... in telehealth thanks to a new partnership with higi. ... patients can routinely track key health measurements, such as ... when they opt in, share them with IMPOWER clinicians ... retail location at no cost. By leveraging this data, ...
(Date:3/31/2016)... PROVIDENCE, R.I. , March 31, 2016  Genomics ... leadership of founding CEO, Barrett Bready , M.D., ... addition, members of the original technical leadership team, including ... Vice President of Product Development, Steve Nurnberg and Vice ... have returned to the company. Dr. Bready ...
Breaking Biology News(10 mins):
(Date:5/19/2016)... , May 19, 2016 ... una sessione orale durante il 52 ° ... n. 8006)    - Le conclusioni dello ... riguarda i pazienti trattati, di cui il 90% presenta una ... sei mesi o più. Il settantadue per cento dei pazienti ...
(Date:5/18/2016)... ... May 18, 2016 , ... ... Camp at The University of Toledo. This two-day camp will take place annually ... explore the field of pharmaceutical sciences in preparation for a university academic program. ...
(Date:5/18/2016)... ... 2016 , ... STACS DNA Inc., the sample tracking software company, today announced ... kit processing to help them save time and reduce errors. , Sexual Assault kits ... processed and victims informed of results. Due to a previous lack of tools, many ...
(Date:5/18/2016)... (PRWEB) , ... May 18, 2016 , ... The Academy ... is now celebrating its dream of reaching a total of $1 million in awarded ... awarded to 10 high school graduates from across the nation has helped bring the ...
Breaking Biology Technology: