Featured Research

from universities, journals, and other organizations

Imiquimod, An Immune Response Modifier, Is Dependent On The OGF-OGFr Signaling Pathway

Date:
July 24, 2008
Source:
Society for Experimental Biology and Medicine
Summary:
Researchers have discovered that the efficacy of imiquimod, a clinically important immune response modifier with potent antiviral and anti-tumor activity, is dependent on the opioid growth factor receptor axis for its action. This discovery, reported in Experimental Biology and Medicine, provides new insights into a widely used drug that may lead to development of new agents that will enhance effectiveness and attenuate side-effects.

Researchers at The Pennsylvania State University College of Medicine, Hershey, Pennsylvania have discovered that the efficacy of imiquimod, a clinically important immune response modifier with potent antiviral and antitumor activity, is dependent on the Opioid Growth Factor (OGF)-OGF receptor (OGFr) axis for its action.

This discovery, reported in the August 08 issue of Experimental Biology and Medicine, provides new insights into a widely used drug that may lead to development of new agents that will enhance effectiveness and attenuate side-effects.

Imiquimod and resiquimod are imidazoquinoline compounds. Imiquimod (Aldara, R-837, S26308), the best characterized and most widely used, is highly efficacious in the treatment of external genital and anal warts, basal cell carcinoma, actinic keratoses, Kaposi's sarcoma, chronic hepatitis C infection, and intraepithelial carcinoma.

Therefore, the underlying mechanism of imiquimod action is of clinical importance. Imiquimod has been reported to be a toll-like receptor-7 agonist, and its anti-tumor effect exerted by modification of the immune response and stimulation of apoptosis. The mechanism of imiquimod on cell proliferation is unclear.

The research team, led by Dr. Ian S. Zagon, Distinguished University Professor, and Dr. Patricia J. McLaughlin, Professor, along with a pre-doctoral student Renee N. Donahue, in the Department of Neural & Behavioral Sciences and collaborator Moshe Rogosnitzky of MedInsight explored mechanisms responsible for the remarkable clinical action of this class of drugs.

Specifically, using tissue culture models, the investigators found that imidazoquinolines upregulate OGFr which in turn stimulates the interaction of the OGF-OGFr axis. This native, tonically active inhibitory pathway is known to regulate cell proliferation by modulating cyclin dependent kinase inhibitors, resulting in a retardation of cells at the G1-S interface of the cell cycle. Neutralization of OGF or knockdown of OGFr by siRNA technology eliminated the inhibitory effects of imidazoquinolines on cell replication. "Thus our data," Dr. Zagon said, "brings a paradigm shift to our thinking about a drug widely used in the clinics. Rather than imiquimod activity being mediated by induction of various cytokines, including interferon (IFN)-α, IFN-γ, tumor necrosis factor-α (TNFα) interleukin (IL)-1α, and IL-12 as currently thought, an entirely new pathway - native to body chemistry - has been discovered to regulate cell proliferation by imidazoquinolines."

Co-author, Moshe Rogosnitzky adds: "The elucidation of imiquimod's immune-independent mechanism of action in cancer also creates exciting new therapeutic possibilities for a number of non-cancer conditions, and these are now being further explored. Such studies could lead to new off-label applications for imiquimod as well as development of imiquimod analogues and unique combination therapies."

Dr. Steven R. Goodman, Editor-in-Chief of Experimental Biology and Medicine stated "Through decades of elegant and ground-breaking work, Zagon and colleagues have identified the role of met-enkephalin (the opioid growth factor –OGF) and the OGF receptor in regulating cell proliferation. The current study demonstrates that the mechanism of imidazoquinoline activity is via OGF and OGFr which will have a profound impact on its use as a therapeutic for cancer and many other non-cancerous disorders."


Story Source:

The above story is based on materials provided by Society for Experimental Biology and Medicine. Note: Materials may be edited for content and length.


Cite This Page:

Society for Experimental Biology and Medicine. "Imiquimod, An Immune Response Modifier, Is Dependent On The OGF-OGFr Signaling Pathway." ScienceDaily. ScienceDaily, 24 July 2008. <www.sciencedaily.com/releases/2008/07/080724150439.htm>.
Society for Experimental Biology and Medicine. (2008, July 24). Imiquimod, An Immune Response Modifier, Is Dependent On The OGF-OGFr Signaling Pathway. ScienceDaily. Retrieved July 23, 2014 from www.sciencedaily.com/releases/2008/07/080724150439.htm
Society for Experimental Biology and Medicine. "Imiquimod, An Immune Response Modifier, Is Dependent On The OGF-OGFr Signaling Pathway." ScienceDaily. www.sciencedaily.com/releases/2008/07/080724150439.htm (accessed July 23, 2014).

Share This




More Health & Medicine News

Wednesday, July 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Idaho Boy Helps Brother With Disabilities Complete Triathlon

Idaho Boy Helps Brother With Disabilities Complete Triathlon

Newsy (July 23, 2014) An 8-year-old boy helped his younger brother, who has a rare genetic condition that's confined him to a wheelchair, finish a triathlon. Video provided by Newsy
Powered by NewsLook.com
Stone Fruit Listeria Scare Causes Sweeping Recall

Stone Fruit Listeria Scare Causes Sweeping Recall

Newsy (July 22, 2014) The Wawona Packing Company has issued a voluntary recall on the stone fruit it distributes due to a possible Listeria outbreak. Video provided by Newsy
Powered by NewsLook.com
Huge Schizophrenia Study Finds Dozens Of New Genetic Causes

Huge Schizophrenia Study Finds Dozens Of New Genetic Causes

Newsy (July 22, 2014) The 83 new genetic markers could open dozens of new avenues for schizophrenia treatment research. Video provided by Newsy
Powered by NewsLook.com
CDC Head Concerned About a Post-Antibiotic Era

CDC Head Concerned About a Post-Antibiotic Era

AP (July 22, 2014) Sounding alarms about the growing threat of antibiotic resistance, CDC Director Tom Frieden warned Tuesday if the global community does not confront the problem soon, the world will be living in a devastating post-antibiotic era. (July 22) Video provided by AP
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