Navigation Links
New hope for cancer comes straight from the heart
Date:1/5/2009

Digitalis-based drugs like digoxin have been used for centuries to treat patients with irregular heart rhythms and heart failure and are still in use today. In the Dec. 16 issue of the Proceedings of the National Academy of Sciences, researchers at the Johns Hopkins University School of Medicine now report that this same class of drugs may hold new promise as a treatment for cancer. This finding emerged through a search for existing drugs that might slow or stop cancer progression.

"This is really exciting, to find that a drug already deemed safe by the FDA also can inhibit a protein crucial for cancer cell survival," says Gregg L. Semenza, M.D., Ph.D., director of the vascular program at the Johns Hopkins Institute for Cell Engineering and a member of the McKusick-Nathans Institute of Genetic Medicine.

Semenza and his team have long studied the hypoxia-inducible factor, or HIF-1, protein, which controls genes that help cells survive under low-oxygen conditions. HIF-1 turns on genes that grow new blood vessels to help oxygen-starved cells survive. Regions of low oxygen are common within the environment of fast-growing solid tumors.

"Oxygen-deprived cancer cells increase their HIF-1 levels to survive in these unfavorable conditions," says Semenza. "So turning down or blocking HIF-1 may be key to slowing or stopping these cells from growing."

The researchers took advantage of the Johns Hopkins Drug Library, a collection of more than 3,000 drugs already FDA approved or currently being tested in phase II clinical trials, assembled by Hopkins pharmacology professor Jun O. Liu. In this study, the research team tested every drug in the library for its ability to turn down HIF-1in cancer cells. The top 20 candidates identified were able to reduce HIF-1 by more than 88 percent, and more than half of these 20 belong to a class of drugs already commonly used for treating heart failure, and included digoxin.

The researchers focused on digoxin because of its already well-established clinical use. They treated prostate cancer cells grown at normal and low-oxygen levels with digoxin for three days and counted the number of cells each day. They found that cells treated with digoxin significantly slowed their growth, with fewer total cells after three days and increased numbers of cells that had stopped growing when compared to untreated cells.

"Many drugs may appear promising when used to treat cancer cells in a dish in the lab, but may have little or no effect on tumors in living animals," says Huafeng Zhang, Ph.D., a research associate in the Department of Oncology and the Institute for Cell Engineering at Hopkins.

To see if digoxin had the same effect on cancer cells in the physiological context of a whole animal, the team administered daily injections of digoxin to mice with tumors. In untreated mice, tumors were large enough to be felt within nine days, but in treated mice, tumors could first be felt only after as long as 15 to 28 days. The team then examined tumors from the mice and found that HIF-1 levels were lower than tumors from untreated mice. The team then went on to show that it is digoxin specifically reducing HIF-1 that leads to the anti-tumor results they saw.

While Zhang thinks it is possible that drugs like digoxin could someday be used for treating cancer, she cautions that a great deal of work remains to be done to understand in detail how these drugs inhibit HIF-1 and slow or stop tumor growth. Also, since this class of drugs acts by both strengthening and slowing down the rhythm of the heart, she notes that patients can safely tolerate them in only a limited dosage rangea range that is lower than the concentrations of digoxin used in this study. "We're trying to kill a tumor," she says, "We don't want to stop a heart."


'/>"/>

Contact: Audrey Huang
audrey@jhmi.edu
410-614-5105
Johns Hopkins Medical Institutions
Source:Eurekalert

Related medicine news :

1. Cell biologists identify new tumor suppressor for lung cancer
2. New insight into aggressive childhood cancer
3. Gene plays dual role in breast cancers with poor prognosis
4. Relocation plan of metastatic cancer cells uncovered by Stanford researchers
5. Obesity Linked to Ovarian Cancer
6. Study links obesity to elevated risk of ovarian cancer
7. Treadmill Desks More Effective in Cancer Prevention for Women than Vitamin C, E and Beta Carotene Supplementation
8. Dormant cancer cells rely on cellular self-cannibalization to survive
9. Molecular imaging enables earlier, individualized treatment of thyroid cancer
10. Family history of prostate cancer does not affect some treatment outcomes
11. Lung cancer cells activate inflammation to induce metastasis
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:12/2/2016)... ... , ... Sourced from the Isbre Springs beneath the 5,000 year old Hardanger ... of just 6 ppm TDS (Total Dissolved Solids) in addition to its excellent taste ... several ShopRite and FoodTown stores in NJ and received rave comments from consumers. , ...
(Date:12/2/2016)... ... December 02, 2016 , ... Clarify Health ... has raised $6.0 million in an initial round of funding. The round was ... and their caregivers can receive far better care through the application of the ...
(Date:12/2/2016)... ... ... ‘Tis the season for giving! Today, 20 creative teams across the nation ... the Drug Enforcement Administration as part of the National Red Ribbon Week Photo Contest. ... decorated their campuses with this year’s Red Ribbon Week theme: “YOLO. Be Drug Free,” ...
(Date:11/30/2016)... ... November 30, 2016 , ... Standard ... 75, an annual ranking and recognition of the largest closely held companies headquartered ... ranked from 2008-2016. In addition, Standard Process was awarded the Talent Award for ...
(Date:11/30/2016)... ... 2016 , ... The Cronovo Smartwatch, the first on the ... at an affordable price, is now available on the crowdfunding website Kickstarter ... changer” when it comes to the smartwatch. , "With Cronovo, we’ve combined the ...
Breaking Medicine News(10 mins):
(Date:12/2/2016)... -- Boston Scientific Corporation (NYSE: BSX ) ... assets and capabilities of the Neovasc, Inc., (NASDAQ: ... as well as a 15% equity stake in Neovasc, ... Neovasc advanced biological tissue business makes elements used in ... System. * Upon completion of the transaction, the ...
(Date:12/2/2016)... , Dec. 2, 2016 Lianluo ... Smart" or "the Company") which develops, markets and ... in China and international ... Disease Diagnosis and Treatment New Progress Forum, co-hosted ... Guangdong Province , Guangdong Provincial People,s ...
(Date:12/2/2016)... 2016 On Thursday, the NASDAQ Composite ... while the Dow Jones Industrial Average managed to stay in ... markets, which prompted Stock-callers this morning to look at the ... NUVA ), Smith & Nephew PLC (NYSE: ... and Cesca Therapeutics Inc. (NASDAQ: KOOL ). You ...
Breaking Medicine Technology: