Nav: Home

Researchers discover a weakness in a rare cancer that could be exploited with drugs

February 14, 2019

Cancer cells are, in some respects, impressive: They can grow relentlessly, sidestep the aging process by becoming immortal, and evade the immune system's persistent attacks. But in the process of acquiring such superpowers, the cells must occasionally relinquish other, more mundane skills--including the ability to produce certain nutrients.

Researchers at The Rockefeller University now announce the discovery of a rare tumor type that is unable to synthesize cholesterol, a molecule without which cells can't survive.

"These cells become dependent on taking up cholesterol from their environment, and we can use this dependency to design therapies that block cholesterol uptake," says Kivanç Birsoy, the Chapman Perelman Assistant Professor, who reports the findings in Nature.

Cutting back on cholesterol

Birsoy has long been fascinated by the fact that, in rare cases, cancers lose the ability to make key nutrients. Some types of leukemia, for example, are unable to synthesize the amino acid asparagine. As a first line of defense against these cancers, doctors give patients a drug known as asparaginase, which breaks down the amino acid, removing it from the blood. Without access to external stores of the nutrient, the cancer cells die.

Birsoy and his colleagues - including Javier Garcia-Bermudez, a postdoctoral fellow in Birsoy's lab - set out to look for other cancer types that might be vulnerable to cut-offs in nutrient supply. The researchers looked first to cholesterol, an essential ingredient for all dividing cells. Typically, cancer cells either make cholesterol themselves, or acquire it from the cellular environment, where it is present in the form of low-density lipoprotein (LDL).

The researchers placed 28 different cancer cell types in an environment that lacked cholesterol, and noted which ones survived. Cells associated with a rare type of lymphoma, known as ALK-positive ALCL, did not endure these conditions, suggesting that these cells could not synthesize cholesterol on their own.

When the researchers reviewed gene expression data from the cholesterol-dependent cell lines, they discovered that these cancers lacked an enzyme involved in the synthesis of cholesterol. Without this enzyme, the cells accumulated squalene, a poorly studied metabolite that acts as a precursor for cholesterol.

Though the inability to make cholesterol should be a bad thing, a buildup of squalene, Birsoy notes, may actually be beneficial to cancer cells. "These cells need to deal with oxidative stress in their environment. And we believe squalene is one way to increase antioxidant capacity," he says.

Exploiting vulnerability

In another experiment, the researchers knocked out the cancer cells' LDL receptors, a primary means of absorbing external cholesterol. As a result, the cells had no access to the nutrient and died. This outcome points to a novel way to kill ALCL cells, which can become resistant to chemotherapy. "We think therapies that block uptake of cholesterol might be particularly effective against drug-resistant forms of ALCL," says Birsoy.

Moving forward, the researchers plan to screen other cancers for similar vulnerabilities. Says Birsoy: "This is part of a larger strategy of looking for nutrient dependencies or deficiencies in various cancer types."
-end-


Rockefeller University

Related Cancer Cells Articles:

Drug that keeps surface receptors on cancer cells makes them more visible to immune cells
A drug that is already clinically available for the treatment of nausea and psychosis, called prochlorperazine (PCZ), inhibits the internalization of receptors on the surface of tumor cells, thereby increasing the ability of anticancer antibodies to bind to the receptors and mount more effective immune responses.
Engineered bone marrow cells slow growth of prostate and pancreatic cancer cells
In experiments with mice, researchers at the Johns Hopkins Kimmel Cancer Center say they have slowed the growth of transplanted human prostate and pancreatic cancer cells by introducing bone marrow cells with a specific gene deletion to induce a novel immune response.
First phase i clinical trial of CRISPR-edited cells for cancer shows cells safe and durable
Following the first US test of CRISPR gene editing in patients with advanced cancer, researchers report these patients experienced no negative side effects and that the engineered T cells persisted in their bodies -- for months.
Zika virus' key into brain cells ID'd, leveraged to block infection and kill cancer cells
Two different UC San Diego research teams identified the same molecule -- αvβ5 integrin -- as Zika virus' key to brain cell entry.
Plant-derived SVC112 hits cancer stem cells, leaves healthy cells alone
Study shows Colorado drug SVC112 stops production of proteins that cancer stem cells need to survive and grow.
Changes in the metabolism of normal cells promotes the metastasis of ovarian cancer cells
A systematic examination of the tumor and the tissue surrounding it -- particularly normal cells in that tissue, called fibroblasts -- has revealed a new treatment target that could potentially prevent the rapid dissemination and poor prognosis associated with high-grade serous carcinoma (HGSC), a tumor type that primarily originates in the fallopian tubes or ovaries and spreads throughout the abdominal cavity.
The development of brain stem cells into new nerve cells and why this can lead to cancer
Stem cells are true Jacks-of-all-trades of our bodies, as they can turn into the many different cell types of all organs.
White blood cells related to allergies may also be harnessed to destroy cancer cells
A new Tel Aviv University study finds that white blood cells which are responsible for chronic asthma and modern allergies may be used to eliminate malignant colon cancer cells.
Conversion of breast cancer cells into fat cells impedes the formation of metastases
An innovative combination therapy can force malignant breast cancer cells to turn into fat cells.
Breast cancer cells in mice tricked into turning into fat cells
As cancer cells respond to cues in their microenvironment, they can enter a highly plastic state in which they are susceptible to transdifferentiation into a different type of cell.
More Cancer Cells News and Cancer Cells Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: Reinvention
Change is hard, but it's also an opportunity to discover and reimagine what you thought you knew. From our economy, to music, to even ourselves–this hour TED speakers explore the power of reinvention. Guests include OK Go lead singer Damian Kulash Jr., former college gymnastics coach Valorie Kondos Field, Stockton Mayor Michael Tubbs, and entrepreneur Nick Hanauer.
Now Playing: Science for the People

#562 Superbug to Bedside
By now we're all good and scared about antibiotic resistance, one of the many things coming to get us all. But there's good news, sort of. News antibiotics are coming out! How do they get tested? What does that kind of a trial look like and how does it happen? Host Bethany Brookeshire talks with Matt McCarthy, author of "Superbugs: The Race to Stop an Epidemic", about the ins and outs of testing a new antibiotic in the hospital.
Now Playing: Radiolab

Dispatch 6: Strange Times
Covid has disrupted the most basic routines of our days and nights. But in the middle of a conversation about how to fight the virus, we find a place impervious to the stalled plans and frenetic demands of the outside world. It's a very different kind of front line, where urgent work means moving slow, and time is marked out in tiny pre-planned steps. Then, on a walk through the woods, we consider how the tempo of our lives affects our minds and discover how the beats of biology shape our bodies. This episode was produced with help from Molly Webster and Tracie Hunte. Support Radiolab today at Radiolab.org/donate.