Featured Research

from universities, journals, and other organizations

MicroRNA's role in breast cancer metastasis identified

Date:
April 14, 2014
Source:
City of Hope
Summary:
A microRNA called miR-105 helps cancer metastasize by breaking down the building blocks of blood vessels' barriers, allowing the cancer cells to enter the bloodstream, researchers have found. "MicroRNAs were discovered over two decades ago, but it's only recently that the scientific community started looking into their role in cancer," said the senior author of the study. "When we found out that cancer cells can make and secrete microRNAs, we wanted to investigate their role in interactions between cancer cells and normal tissue."

City of Hope researchers found that a microRNA called miR-105 helps cancer metastasize by breaking down the building blocks of blood vessels' barriers, allowing the cancer cells to enter the bloodstream.
Credit: Bob Fong

Metastasis -- the spreading of cancer cells from a primary tumor site to other parts of the body -- generally leads to poorer outcomes for patients, so oncologists and researchers are constantly seeking new ways to detect and thwart this malicious process. Now City of Hope researchers may have identified a substance that contributes to it: microRNAs, particularly one called miR-105 that is secreted by breast cancer cells.

Related Articles


The findings were published in the April 14 issue of Cancer Cell.

"MicroRNAs were discovered over two decades ago, but it's only recently that the scientific community started looking into their role in cancer," said S. Emily Wang, Ph.D., associate professor in the Department of Cancer Biology and senior author of the study. "When we found out that cancer cells can make and secrete microRNAs, we wanted to investigate their role in interactions between cancer cells and normal tissue."

MicroRNAs are small snippets of genetic code that regulate gene expression. This, in turn, alters the quantity and quality of proteins that are manufactured by those genes. In this particular study, Wang and her team found that miR-105 helps breast cancer metastasize by interacting with the gene TJP1. This gene is responsible for producing a protein, ZO-1, used in the boundaries between blood vessel cells.

These boundaries, called tight junctions, are normally impermeable to most substances, including cancer cells. miR-105's interference leads to the degradation of ZO-1, which makes the junction leaky and allows cancer cells to break free from the primary tumor and enter the bloodstream.

miR-105's ability to break down tight junctions also helps breast cancer cells invade other organs, including the brain. There, miR-105 leads to the degradation of the blood-brain barrier, which also uses ZO-1.

These findings are supported by further research with animal models. In this part of the study, tumors with overexpressed miR-105 led to more extensive metastases in mice. Meanwhile, mice that were given an experimental anti-miR-105 drug had smaller tumors that were less likely to spread. The drug also restored the tight junction integrity of their blood vessels.

From these findings, Wang suggested that miR-105 -- which is detectable in the bloodstream -- could be used as a biomarker to determine the metastatic potential of a primary breast cancer. It could also be used to catch the beginning of metastasis, giving oncologists enough time to try other treatments before secondary tumors form.

Wang and her team are currently conducting additional preclinical studies on miR-105 and other cancer-secreted microRNAs, with the goal developing a reliable test to screen for these molecules and develop drugs that can target them.


Story Source:

The above story is based on materials provided by City of Hope. Note: Materials may be edited for content and length.


Journal Reference:

  1. Weiying Zhou, Miranda Y. Fong, Yongfen Min, George Somlo, Liang Liu, Melanie R. Palomares, Yang Yu, Amy Chow, Sean Timothy Francis O’Connor, Andrew R. Chin, Yun Yen, Yafan Wang, Eric G. Marcusson, Peiguo Chu, Jun Wu, Xiwei Wu, Arthur Xuejun Li, Zhuo Li, Hanlin Gao, Xiubao Ren, Mark P. Boldin, Pengnian Charles Lin, Shizhen Emily Wang. Cancer-Secreted miR-105 Destroys Vascular Endothelial Barriers to Promote Metastasis. Cancer Cell, 2014; 25 (4): 501 DOI: 10.1016/j.ccr.2014.03.007

Cite This Page:

City of Hope. "MicroRNA's role in breast cancer metastasis identified." ScienceDaily. ScienceDaily, 14 April 2014. <www.sciencedaily.com/releases/2014/04/140414154410.htm>.
City of Hope. (2014, April 14). MicroRNA's role in breast cancer metastasis identified. ScienceDaily. Retrieved November 27, 2014 from www.sciencedaily.com/releases/2014/04/140414154410.htm
City of Hope. "MicroRNA's role in breast cancer metastasis identified." ScienceDaily. www.sciencedaily.com/releases/2014/04/140414154410.htm (accessed November 27, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Thursday, November 27, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Ebola Leaves Orphans Alone in Sierra Leone

Ebola Leaves Orphans Alone in Sierra Leone

AFP (Nov. 27, 2014) — The Ebola epidemic sweeping Sierra Leone is having a profound effect on the country's children, many of whom have been left without any family members to support them. Duration: 01:02 Video provided by AFP
Powered by NewsLook.com
Experimental Ebola Vaccine Shows Promise In Human Trial

Experimental Ebola Vaccine Shows Promise In Human Trial

Newsy (Nov. 27, 2014) — A recent test of a prototype Ebola vaccine generated an immune response to the disease in subjects. Video provided by Newsy
Powered by NewsLook.com
Pet Dogs to Be Used in Anti-Ageing Trial

Pet Dogs to Be Used in Anti-Ageing Trial

Reuters - Innovations Video Online (Nov. 26, 2014) — Researchers in the United States are preparing to discover whether a drug commonly used in human organ transplants can extend the lifespan and health quality of pet dogs. Video provided by Reuters
Powered by NewsLook.com
Today's Prostheses Are More Capable Than Ever

Today's Prostheses Are More Capable Than Ever

Newsy (Nov. 26, 2014) — Advances in prosthetics are making replacement body parts stronger and more lifelike than they’ve ever been. Video provided by Newsy
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