Signal may send cancer's cellular factories into overdrive

July 9, 2014

A network of signals active in almost all types of cancer sends the protein factories in our cells into overdrive, and may help fuel a tumour's uncontrolled growth, new research suggests.

Scientists at The Institute of Cancer Research, London, identified a molecular trigger responsible for ratcheting up activity of the (ER) – the cellular factory that makes the building blocks need to keep growing.

A protein in the TOR signalling pathway, called SREBP, controls the flow of messages to the endoplasmic reticulum telling it to expand – and could allow cancer cells to produce enough proteins and lipids to fuel their non-stop growth.

The findings may help to explain how cancer cells maintain their high levels of metabolism – and could uncover future targets for cancer treatment.

The study was published in the journal PLOS ONE, and funded by the Biotechnology and Biological Sciences Research Council (BBSRC), with additional support from the Wellcome Trust.

Unlike healthy cells, cancer cells are constantly growing, and so need to keep making proteins and lipids - the building blocks of all cells.

In constant growth can overwhelm cellular factories like the ER, leading to cell stress and death, but cancer cells manage to keep their factories running at high capacity to fuel non-stop growth.

Scientists at The Institute of Cancer Research (ICR) used the cells of fruit flies, modified with a fluorescent marker that is activated when the cells are put under stress, to identify the signals responsible for driving up activity of the ER.

They systematically silenced genes thought to be important to the smooth working of the ER and measured the stress signals produced in response.

They found that silencing the TOR signalling pathway - activated in many different types of cancer - increased ER stress in the cells. When they blocked TOR signals, cells took longer to recover from ER stress and the ER factory shrank.

Their findings suggest the TOR signalling pathway promotes cell growth while simultaneously ensuring productivity of the ER matches this growth. And the protein SREBP, which is part of the TOR signalling pathway, appeared to be essential for promoting expansion of the ER, and ensuring it carried out its factory activities effectively.

Lead author Dr Chris Bakal, leader of the Dynamical Cell Systems Team at The Institute of Cancer Research, London, said: "The endoplasmic reticulum is the factory of our cells, creating the proteins and lipids needed for our cells to grow and proliferate. In cancer cells, this factory is active all the time, churning out the that cancer cells need for their rapid growth.

"We have discovered the key role played by the TOR signalling pathway in driving the expansion of the endoplasmic reticulum, and sending a cell's factories into overdrive. The TOR pathway is active in many types of cancer, and our study provides new insights into how cancer metabolism works, and suggests that these metabolic signals could be excellent targets for future treatments."

Explore further: Chinese herbal extract may help kill off pancreatic cancer cells

Related Stories

Chinese herbal extract may help kill off pancreatic cancer cells

July 1, 2014
A diagnosis of pancreatic cancer—the fourth most common cause of cancer death in the U.S.—can be devastating. Due in part to aggressive cell replication and tumor growth, pancreatic cancer progresses quickly and has a ...

Seemingly invincible cancers stem cells reveal a weakness

June 5, 2014
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 ...

Tuberculosis protein helps spot breast cancer's signals

July 1, 2014
(Medical Xpress)—Scientists have used a protein from Mycobacterium tuberculosis – the bacterium that causes most cases of tuberculosis – to unravel the signals produced by cancer from those of healthy cells.

Disruptions in a protein-processing pathway appear to promote aggressive proliferation and invasion in tumor cells

January 29, 2014
Many proteins at the cell surface are 'decorated' with carbohydrate molecules called glycans. Changes in a cell's glycan profile can greatly alter how it behaves and interacts with its environment, and abnormalities in this ...

Molecular 'scaffold' could hold key to new dementia treatments

June 3, 2014
Researchers at King's College London have discovered how a molecular 'scaffold' which allows key parts of cells to interact, comes apart in dementia and motor neuron disease, revealing a potential new target for drug discovery.

Signalling protein plays different roles in breast cancer and normal cells

June 20, 2014
A key step in developing effective cancer therapies is identifying differences between normal, healthy cells and cancer cells – these differences can then be exploited to specifically kill tumour cells.

Recommended for you

Researchers release first draft of a genome-wide cancer 'dependency map'

July 27, 2017
In one of the largest efforts to build a comprehensive catalog of genetic vulnerabilities in cancer, researchers from the Broad Institute of MIT and Harvard and Dana-Farber Cancer Institute have identified more than 760 genes ...

Cancer-death button gets jammed by gut bacterium

July 27, 2017
Researchers at Michigan Medicine and in China showed that a type of bacterium is associated with the recurrence of colorectal cancer and poor outcomes. They found that Fusobacterium nucleatum in the gut can stop chemotherapy ...

Long-sought mechanism of metastasis is discovered in pancreatic cancer

July 27, 2017
Cells, just like people, have memories. They retain molecular markers that at the beginning of their existence helped guide their development. Cells that become cancerous may be making use of these early memories to power ...

Manmade peptides reduce breast cancer's spread

July 27, 2017
Manmade peptides that directly disrupt the inner workings of a gene known to support cancer's spread significantly reduce metastasis in a mouse model of breast cancer, scientists say.

Blocking the back-door that cancer cells use to escape death by radiotherapy

July 27, 2017
A natural healing mechanism of the body may be reducing the efficiency of radiotherapy in breast cancer patients, according to a new study.

Glowing tumor technology helps surgeons remove hidden cancer cells

July 27, 2017
Surgeons were able to identify and remove a greater number of cancerous nodules from lung cancer patients when combining intraoperative molecular imaging (IMI) - through the use of a contrast agent that makes tumor cells ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.