Featured Research

from universities, journals, and other organizations

How Chemotherapy Drugs Block Blood Vessel Growth, Slow Cancer Spread

Date:
January 25, 2009
Source:
Johns Hopkins Medical Institutions
Summary:
Researchers have discovered how a whole class of commonly used chemotherapy drugs can block cancer growth. Their findings suggest that a subgroup of cancer patients might particularly benefit from these drugs.

Researchers at the Johns Hopkins University School of Medicine have discovered how a whole class of commonly used chemotherapy drugs can block cancer growth. Their findings, recently reported online at the Proceedings of the National Academy of Sciences Early Edition, suggest that a subgroup of cancer patients might particularly benefit from these drugs.

The anthracycline class of chemotherapeutics — doxorubicin (Adriamycin), daunorubicin, epirubicin, idarubicin — have been used for four decades to treat many types of cancer, including leukemia, lymphoma, sarcomas and carcinomas, The standard method of administration had been to use the highest tolerable dose every few weeks to kill all rapidly growing cells by preventing them from accurately copying their genetic material.

"But the late Judah Folkman discovered in 2000 that so-called metronomic treatment, giving patients lower doses of these drugs more frequently, can keep cancer growth at bay by blocking blood vessel formation, but the exact mechanism by which this occurred wasn't known," 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. "Now we've shown how it happens and what players are involved, which could help shape future clinical trials for patients with certain types of cancers."

Semenza and his team have long studied how the hypoxia-inducible factor, or HIF-1, protein helps cells survive under low-oxygen conditions. HIF-1 turns on genes that grow new blood vessels to help oxygen-starved cells, like those found in fast-growing solid tumors, survive.

To look for drugs that can prevent new blood vessel growth, the team tested more than 3,000 already FDA-approved drugs in the Johns Hopkins Drug Library for their ability to stop HIF-1 activity. Using modified liver cancer cells growing in low oxygen, the team treated cells with each of the drugs in the library and examined whether the drug could stop HIF-1 from turning on genes.

One drug—daunorubicin—reduced HIF-1's gene-activating ability by more than 99 percent. They tested other members of the anthracycline drug class and found that doxorubicin, epirubicin and idarubicin also blocked HIF-1 activity. But further examination showed that both drug-treated and untreated cells contained similar amounts of HIF-1 protein, leading the researchers to conclude that the drugs are not affecting whether or not HIF-1 is made.

To turn on genes, HIF-1 must bind to DNA. So the research team looked at drug-treated and untreated cells and compared regions of DNA known to be bound by HIF-1. The sites that are bound by HIF-1 in untreated cells were found unbound in anthracycline treated cells. "We know that this class of drug prefers to bind to DNA sequences that are similar to the DNA sequence bound by HIF-1, but this is the first direct evidence that anthracyclines prevent HIF-1 from binding to and turning on target genes," says Semenza.

To see if the interference with HIF-1 binding to DNA affects cancer growth, the team grew tumors in mice from human prostate cancer cells. They treated these mice with daunorubicin, doxorubicin or saline once a day for five days and measured tumor size. Tumors in saline-treated mice nearly doubled in size in that time, whereas tumors in the drug-treated mice stayed the same size or became smaller.

When the team examined the tumors from drug-treated mice, they found that the number of blood vessels was dramatically reduced compared to mice treated with saline. Additional tests revealed that the genes that HIF-1 turns on to drive blood vessel formation were turned off in tumors from the drug-treated mice.

"What this means, we hope, is that patients with a prostate cancer that has high HIF-1 levels — which puts them at greater risk of relapse following surgery or radiation therapy — might benefit from treatment with these drugs," says Semenza. "However, clinical trials are necessary to determine whether this approach will help keep cancer patients alive."

Authors of this paper are KangAe Lee, David Z. Qian, Sergio Rey, Hong Wei, Jun O. Liu and Gregg L. Semenza, all of Hopkins.

This work was funded by the Flight Attendant Medical Research Institute and the Johns Hopkins Institute for Cell Engineering.


Story Source:

The above story is based on materials provided by Johns Hopkins Medical Institutions. Note: Materials may be edited for content and length.


Cite This Page:

Johns Hopkins Medical Institutions. "How Chemotherapy Drugs Block Blood Vessel Growth, Slow Cancer Spread." ScienceDaily. ScienceDaily, 25 January 2009. <www.sciencedaily.com/releases/2009/01/090122164319.htm>.
Johns Hopkins Medical Institutions. (2009, January 25). How Chemotherapy Drugs Block Blood Vessel Growth, Slow Cancer Spread. ScienceDaily. Retrieved September 20, 2014 from www.sciencedaily.com/releases/2009/01/090122164319.htm
Johns Hopkins Medical Institutions. "How Chemotherapy Drugs Block Blood Vessel Growth, Slow Cancer Spread." ScienceDaily. www.sciencedaily.com/releases/2009/01/090122164319.htm (accessed September 20, 2014).

Share This



More Health & Medicine News

Saturday, September 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Could Grief Affect The Immune Systems Of Senior Citizens?

Could Grief Affect The Immune Systems Of Senior Citizens?

Newsy (Sep. 19, 2014) The study found elderly people are much more likely to become susceptible to infection than younger adults going though a similar situation. Video provided by Newsy
Powered by NewsLook.com
Jury Delivers Verdict in Salmonella Trial

Jury Delivers Verdict in Salmonella Trial

AP (Sep. 19, 2014) A federal jury has convicted three people in connection with an outbreak of salmonella poisoning five years ago that sickened hundreds of people and was linked to a number of deaths. (Sept. 19) Video provided by AP
Powered by NewsLook.com
How The 'Angelina Jolie Effect' Increased Cancer Screenings

How The 'Angelina Jolie Effect' Increased Cancer Screenings

Newsy (Sep. 19, 2014) Angelina's Jolie's decision to undergo a preventative mastectomy in 2013 inspired many women to seek early screenings for the disease. Video provided by Newsy
Powered by NewsLook.com
The Cost of Ebola

The Cost of Ebola

Reuters - Business Video Online (Sep. 18, 2014) As Sierra Leone prepares for a three-day "lockdown" in its latest bid to stem the spread of Ebola, Ciara Lee looks at the financial implications of fighting the largest ever outbreak of the disease. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins