Featured Research

from universities, journals, and other organizations

Seemingly invincible cancer stem cells reveal a weakness

Date:
June 5, 2014
Source:
Whitehead Institute for Biomedical Research
Summary:
Metastatic cancer cells, which can migrate from primary tumors to seed new malignancies, have thus far been resistant to the current arsenal of anticancer drugs. Now, however, researchers have identified a critical weakness that actually exploits one of these cells’ apparent strengths—their ability to move and invade tissues. Their research could inform novel approaches to screening tumors for personalized therapy or to drugs that specifically target these cells.

Metastatic cancer cells, which can migrate from primary tumors to seed new malignancies, have thus far been resistant to the current arsenal of anticancer drugs. Now, however, researchers at Whitehead Institute have identified a critical weakness that actually exploits one of these cells' apparent strengths -- their ability to move and invade tissues.

"This is the first vulnerability of invasive cancer cells that we really understand," says Whitehead Member Piyush Gupta, whose lab's latest work is described in the June issue of the journal Cancer Discovery. "For a while we didn't know if they had any vulnerabilities that could be exploited for therapy. Then, a few years ago we discovered they were exquisitely sensitive to some chemical molecules, and therefore had to have a weakness. But we still didn't know at the time what that weakness was. Now we know."

Cancer cells acquire invasive and stem cell-like traits by undergoing a process called an epithelial-to-mesenchymal transition (EMT), which transforms cube-like, immobile cells into elongated, mobile ones. Once mobile, cancer cells can form metastases by using the blood stream as an expressway to distant sites in the body, where they can establish new tumors. In addition to being invasive and metastatic, cancer cells that undergo an EMT are also resistant to radiation and most chemotherapies.

Although they are resistant to most therapies, Gupta and his colleagues had previously identified two compounds with very similar structures that were selectively toxic against the invasive cancer cells that had undergone an EMT, but not their non-invasive counterparts. These unique compounds were discovered in a large screen of over 300,000 chemical compounds.

Intrigued by these compounds that were selectively toxic to metastatic cancer cells, Yuxiong Feng, a postdoctoral researcher in Gupta's lab, further investigated their activity and discovered that the compounds kill by stressing the endoplasmic reticulum (ER) of EMT cells; non-EMT cells were unscathed because their ER was unaffected by these compounds. Feng also found that other chemicals that cause ER stress also similarly dispatched only the metastatic EMT cells. The obvious question was why these otherwise indestructible cells had such sensitive ERs.

A hint lies at the heart of EMT's physiology and function. Invasive cancer cells, like other mesenchymal cells, move by secreting large scaffolding proteins and other proteins that interact with the extracellular matrix, the structural support that holds neighboring cells together. Pumping out these proteins strains the cancer cells' ER to their limit. When Feng treated EMT cells with chemicals that further stressed their ER, the cells died. But when those cells' production of extracellular matrix proteins was artificially blocked, the cells were much less sensitive to the ER-stressing chemicals.

Feng's work points to one specific part of the process, called the PERK pathway, as being particularly important. This pathway helps cells survive the stress of secreting copious amounts of proteins, and in EMT cells, it is always active at a low level. In studying roughly 800 patient tumors (both primary and metastatic) across a range of cancer types, including breast, colon, gastric, and lung, Feng found that the expression of EMT genes was tightly correlated with PERK pathway activity.

"We've found that whenever you have EMT, the PERK pathway is more active," says Feng, who is the first author of the Cancer Discovery paper. "That means we might be able to use PERK pathway activity as a marker to help guide treatment, since tumors with higher PERK activity would likely be more sensitive to further ER stress."

As promising as these developments sound, Feng cautions that further work is needed before PERK screening could become mainstay of cancer diagnostics.

"Our research provides new insights into the biology and weaknesses of invasive cancer cells. Our findings also raise interesting and important questions for further study: how does the PERK pathway support the malignant function of EMT cells? What is the molecular circuitry activated upon EMT that causes cells to secrete copious amounts of extracellular matrix proteins? It's all very exciting."


Story Source:

The above story is based on materials provided by Whitehead Institute for Biomedical Research. The original article was written by Nicole Giese Rura. Note: Materials may be edited for content and length.


Journal Reference:

  1. Y.-x. Feng, E. S. Sokol, C. A. Del Vecchio, S. Sanduja, J. H. L. Claessen, T. A. Proia, D. X. Jin, F. Reinhardt, H. L. Ploegh, Q. Wang, P. B. Gupta. Epithelial-to-Mesenchymal Transition Activates PERK-eIF2 and Sensitizes Cells to Endoplasmic Reticulum Stress. Cancer Discovery, 2014; 4 (6): 702 DOI: 10.1158/2159-8290.CD-13-0945

Cite This Page:

Whitehead Institute for Biomedical Research. "Seemingly invincible cancer stem cells reveal a weakness." ScienceDaily. ScienceDaily, 5 June 2014. <www.sciencedaily.com/releases/2014/06/140605190706.htm>.
Whitehead Institute for Biomedical Research. (2014, June 5). Seemingly invincible cancer stem cells reveal a weakness. ScienceDaily. Retrieved August 1, 2014 from www.sciencedaily.com/releases/2014/06/140605190706.htm
Whitehead Institute for Biomedical Research. "Seemingly invincible cancer stem cells reveal a weakness." ScienceDaily. www.sciencedaily.com/releases/2014/06/140605190706.htm (accessed August 1, 2014).

Share This




More Health & Medicine News

Friday, August 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

House Republicans Vote to Sue Obama Over Healthcare Law

House Republicans Vote to Sue Obama Over Healthcare Law

Reuters - US Online Video (July 31, 2014) The Republican-led House of Representatives votes to sue President Obama, accusing him of overstepping his executive authority in making changes to the Affordable Care Act. Mana Rabiee reports. Video provided by Reuters
Powered by NewsLook.com
Despite Health Questions, E-Cigs Are Beneficial: Study

Despite Health Questions, E-Cigs Are Beneficial: Study

Newsy (July 31, 2014) Citing 81 previous studies, new research out of London suggests the benefits of smoking e-cigarettes instead of regular ones outweighs the risks. Video provided by Newsy
Powered by NewsLook.com
Dangerous Bacteria Kills One in Florida

Dangerous Bacteria Kills One in Florida

AP (July 31, 2014) Sarasota County, Florida health officials have issued a warning against eating raw oysters and exposing open wounds to coastal and inland waters after a dangerous bacteria killed one person and made another sick. (July 31) Video provided by AP
Powered by NewsLook.com
Health Insurers' Profits Slide

Health Insurers' Profits Slide

Reuters - Business Video Online (July 30, 2014) Obamacare-related costs were said to be behind the profit plunge at Wellpoint and Humana, but Wellpoint sees the new exchanges boosting its earnings for the full year. Fred Katayama reports. 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