Featured Research

from universities, journals, and other organizations

Small molecule unlocks key prostate cancer survival tactic

Date:
April 9, 2013
Source:
UC Davis Comprehensive Cancer Center
Summary:
The most recent in a series of studies has shown that a single molecule is at the heart of one of the most basic survival tactics of prostate cancer cells.

The most recent in a series of studies from a team at the UC Davis Comprehensive Cancer Center has shown that a single molecule is at the heart of one of the most basic survival tactics of prostate cancer cells.

Related Articles


A paper published today online in the journal PLOSONE identifies a microRNA called miR-125b as a potential target for treatments designed to stop the proliferation of prostate cancer cells, particularly in patients who have developed a late-stage form of the disease resistant to androgen deprivation therapy.

MicroRNAs are small, single strands of RNA that regulate gene expression processes between larger strands of RNA -- that is, they play vital roles in turning genes on and off. RNA, or ribonucleic acid, is a family of large molecules involved in the coding, decoding, regulation and expression of genes.

The team, led by UC Davis urology professor Ralph de Vere White, director of the comprehensive cancer center and senior author on the study, had found in previous studies over the last several years that miR-125b is highly expressed in human prostate cancer, turning off some tumor genes that if left unaltered would have made therapy more effective. This was particularly true at the point in late-stage treatment when patients' levels of testosterone, or androgen, have purposely been lowered as a form of treatment for metastatic prostate cancer. Testosterone is a driver of tumor growth.

"Our latest research demonstrates that elevated MiR-125B in prostate cancer cells is a mechanism that thwarts our efforts to eradicate the disease," said de Vere White.

The UC Davis study details exactly how miR-125b represses a protein called p14ARF in two prostate cancer cell lines and in a mouse model. The study is important because it is the first to identify miR-125b as a direct regulator of p14ARF in metastatic prostate cancer cells.

P14ARF is an important link in the pathway between two genes that suppress prostate cancer cells, p53 and PUMA. When miR-125b downregulates p14ARF, p53 is restrained from its job of killing cancer cells. Treatment of prostate cancer cells with an inhibitor of miR-125 results in increased expression of p14ARF and full functioning of p53, leading to the death of prostate cancer cells, known as apoptosis, and a concomitant slowing tumor growth.

This is known as a p53-dependent pathway; there's also a p53-independent pathway, and miR-125b downregulates that as well. Thus this paper shows that, through its manipulation of p14ARF, miR-125b is a major modulator of cell death, whether p53-dependent or independent. Since all prostate cancer cells are one or the other, this phenomenon impacts all of them, which makes miR-125b an important molecule in the progression of prostate cancer.

"These latest findings reinforce our belief that miR-125b has potential as a therapeutic target for the management of patients with metastatic prostate cancer," said deVere White. "We're pleased that these data build so successfully on our earlier studies of miR-125b and bring us closer to patient treatment."

Other authors were Sumaira Amir, Ai-Hong Ma, Xu-Bao Shi, Lingru Xue, Hsing-Jien Kung, all of the UC Davis School of Medicine. The study was supported by grants from the National Cancer Institute (CA136597) and Department of Defense (PC080488).


Story Source:

The above story is based on materials provided by UC Davis Comprehensive Cancer Center. Note: Materials may be edited for content and length.


Journal Reference:

  1. Sumaira Amir, Ai-Hong Ma, Xu-Bao Shi, Lingru Xue, Hsing-Jien Kung, Ralph W. deVere White. Oncomir miR-125b Suppresses p14ARF to Modulate p53-Dependent and p53-Independent Apoptosis in Prostate Cancer. PLoS ONE, 2013; 8 (4): e61064 DOI: 10.1371/journal.pone.0061064

Cite This Page:

UC Davis Comprehensive Cancer Center. "Small molecule unlocks key prostate cancer survival tactic." ScienceDaily. ScienceDaily, 9 April 2013. <www.sciencedaily.com/releases/2013/04/130409173238.htm>.
UC Davis Comprehensive Cancer Center. (2013, April 9). Small molecule unlocks key prostate cancer survival tactic. ScienceDaily. Retrieved November 1, 2014 from www.sciencedaily.com/releases/2013/04/130409173238.htm
UC Davis Comprehensive Cancer Center. "Small molecule unlocks key prostate cancer survival tactic." ScienceDaily. www.sciencedaily.com/releases/2013/04/130409173238.htm (accessed November 1, 2014).

Share This



More Health & Medicine News

Saturday, November 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Melafind: Spotting Melanoma Without a Biopsy

Melafind: Spotting Melanoma Without a Biopsy

Ivanhoe (Oct. 31, 2014) The MelaFind device is a pain-free way to check suspicious moles for melanoma, without the need for a biopsy. Video provided by Ivanhoe
Powered by NewsLook.com
Battling Multiple Myeloma

Battling Multiple Myeloma

Ivanhoe (Oct. 31, 2014) The answer isn’t always found in new drugs – repurposing an ‘old’ drug that could mean better multiple myeloma treatment, and hope. Video provided by Ivanhoe
Powered by NewsLook.com
Chronic Inflammation and Prostate Cancer

Chronic Inflammation and Prostate Cancer

Ivanhoe (Oct. 31, 2014) New information that is linking chronic inflammation in the prostate and prostate cancer, which may help doctors and patients prevent cancer in the future. Video provided by Ivanhoe
Powered by NewsLook.com
Sickle Cell: Stopping Kids’ Silent Strokes

Sickle Cell: Stopping Kids’ Silent Strokes

Ivanhoe (Oct. 31, 2014) Blood transfusions are proving crucial to young sickle cell patients by helping prevent strokes, even when there is no outward sign of brain injury. 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