Featured Research

from universities, journals, and other organizations

New Evidence Of Prolactin's Possible Role In Breast Cancer Uncovered

Date:
October 3, 2007
Source:
Thomas Jefferson University
Summary:
Scientists have discovered new molecular evidence of the role of the hormone prolactin in breast cancer. They have found that prolactin, a pituitary hormone that normally stimulates breast development and milk production, initiates a new "signaling pathway" that may regulate the growth and survival of breast cancer cells.

Scientists at the Kimmel Cancer Center at Jefferson in Philadelphia have discovered new molecular evidence of the role of the hormone prolactin in breast cancer. They have found that prolactin, a pituitary hormone that normally stimulates breast development and milk production, initiates a new "signaling pathway" that may regulate the growth and survival of breast cancer cells.

The work, which appears this month in the journal Molecular Endocrinology, identifies the protein Jak1 as playing a key part in prolactin signaling in breast cancer. Jak1, which belongs to the cell growth-promoting tyrosine kinase class of enzymes, could represent a new drug target for treating breast cancer.

"In breast cancer cells, we found that Jak1 not only stimulates conventional prolactin signaling via proteins such as Stat5, but also that Jak1 recruited new signals, especially Stat3 and ERK," says Hallgeir Rui, M.D., Ph.D., professor of Cancer Biology at Jefferson Medical College of Thomas Jefferson University and principal investigator of the study. "Because Stat3 and ERK typically are considered tumor-promoting, inhibitors of Jak1 may become useful in breast cancer treatment."

Receptors for prolactin, have previously been shown to promote breast cancer cell growth, survival, and differentiation, Dr. Rui explains, through signaling pathways that involve activation of such proteins as Stat5, ERK, and Akt. Prolactin is also known toactivate Stat3, which has been implicated as an oncogene involved in cancer cell growth and survival. In the current study, when Jak1 protein expression was experimentally disrupted in breast cancer cells, prolactin signaling through Stat3 and ERK was completely blocked. Signaling through Stat5 and Akt was reduced but still present.

"Until now, prolactin was believed to signal only through Jak2 to mediate its effects," says Lynn Neilson, Ph.D., a postdoctoral fellow in the Department of Cancer Biology at Jefferson Medical College and first author of the study. "The unexpected finding that prolactin also activates Jak1 in breast cancer points to a mechanism in cancer cells that further promotes tumor cell growth."

Dr. Rui's laboratory currently is seeking to determine the role of Jak1 in breast cancer cell growth, survival, and invasion, which will be important for establishing the potential usefulness of Jak1 as a new drug target in patients. Prolactin is secreted by the pituitary gland, and important for milk production during lactation. Receptors for this hormone are present on a majority of breast cancers. Prolactin levels in blood are relatively unaffected by menopause, and breast cancer patients are exposed to the hormone across all age groups.

The study was funded by the National Institutes of Health and the Department of Defense.


Story Source:

The above story is based on materials provided by Thomas Jefferson University. Note: Materials may be edited for content and length.


Cite This Page:

Thomas Jefferson University. "New Evidence Of Prolactin's Possible Role In Breast Cancer Uncovered." ScienceDaily. ScienceDaily, 3 October 2007. <www.sciencedaily.com/releases/2007/09/070928141238.htm>.
Thomas Jefferson University. (2007, October 3). New Evidence Of Prolactin's Possible Role In Breast Cancer Uncovered. ScienceDaily. Retrieved October 2, 2014 from www.sciencedaily.com/releases/2007/09/070928141238.htm
Thomas Jefferson University. "New Evidence Of Prolactin's Possible Role In Breast Cancer Uncovered." ScienceDaily. www.sciencedaily.com/releases/2007/09/070928141238.htm (accessed October 2, 2014).

Share This



More Health & Medicine News

Thursday, October 2, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Pregnancy Spacing Could Have Big Impact On Autism Risks

Pregnancy Spacing Could Have Big Impact On Autism Risks

Newsy (Oct. 1, 2014) A new study says children born less than one year and more than five years after a sibling can have an increased risk for autism. Video provided by Newsy
Powered by NewsLook.com
Robotic Hair Restoration

Robotic Hair Restoration

Ivanhoe (Oct. 1, 2014) A new robotic procedure is changing the way we transplant hair. The ARTAS robot leaves no linear scarring and provides more natural results. Video provided by Ivanhoe
Powered by NewsLook.com
Insertable Cardiac Monitor

Insertable Cardiac Monitor

Ivanhoe (Oct. 1, 2014) A heart monitor the size of a paperclip that can save your life. The “Reveal Linq” allows a doctor to monitor patients with A-Fib on a continuous basis for up to 3 years! Video provided by Ivanhoe
Powered by NewsLook.com
Attacking Superbugs

Attacking Superbugs

Ivanhoe (Oct. 1, 2014) Two weapons hospitals can use to attack superbugs. Scientists in Ireland created a new gel resistant to superbugs, and a robot that can disinfect a room in minutes. Video provided by Ivanhoe
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:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

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