Study reveals new mechanism that might promote cancer's growth and spread in the body

July 10, 2012 in Cancer

Researchers have discovered a previously unknown mechanism that promotes the growth and spread of cancer. The mechanism involves key immune cells and a new role for small regulatory molecules called microRNA. The findings suggest a new strategy for treating cancer and perhaps diseases of the immune system.

Tiny vesicles released by tumors cells are taken up by healthy immune cells, causing the immune cells to discharge chemicals that foster cancer-cell growth and spread, according to a study by researchers at The Ohio State University Comprehensive Cancer Center – Arthur G. James Cancer Hospital and Richard J. Solove Research Institute (OSUCCC – James) and at Children's Hospital in Los Angeles.

The study uses lung cancer cells to show that the vesicles contain potent regulatory molecules called microRNA, and that the uptake of these molecules by immune cells alters their behavior. The process in humans involves a fundamental receptor of the immune system called Toll-like receptor 8 (TLR8).

The findings, published in the early edition of the Proceedings of the National Academy of Sciences, suggest a new strategy for treating cancer and diseases of the immune system, the researchers say, and a new role for microRNA in the body.

"This study reveals a new function of microRNA, which we show binds to a protein receptor," says principal investigator Dr. Carlo Croce, director of Ohio State's Human Cancer Genetics program and a member of the OSUCCC – James Molecular Biology and Cancer Genetics program. "This tells us that some cancer-released microRNAs can bind and activate a receptor in a hormone-like fashion, and this has not been seen before."

MicroRNAs help control the type and amount of proteins that cells make, and they typically do this by binding with the messenger-RNA that encodes a protein.

"In this study we discovered a completely new mechanism used by cancer to grow and spread, therefore we can develop new drugs that fight tumors by entering this newly identified breach in 's fortress," says co-corresponding author and first author Dr. Muller Fabbri, assistant professor of Pediatrics and Molecular Biology and Immunology at the Keck School of Medicine of the University of Southern California.

"Equally exciting, we show that this mechanism involves a fundamental receptor of the , TLR8, suggesting that the implications of this discovery may extend to other diseases such as autoimmune and inflammatory diseases," Fabbri says.

Key findings of the study include the following:

  • Lung tumor cells secrete microRNA-21 and microRNA-29a in called exosomes, and these exosomes are taken up by called macrophages located where tumor tissue abuts normal tissue.
  • In human macrophages, microRNA-29a and microRNA-21 bind with TLR8, causing the macrophages to secrete -necrosis-factor alpha and interleukin-6, two cytokines that promote inflammation.
  • Increased levels of the two cytokines were associated with an increase in the number of tumors per lung in an animal model, while a drop in those levels led to a drop in the number per lung, suggesting that they also play a role in metastasis.

Journal reference: Proceedings of the National Academy of Sciences search and more info website

Provided by Ohio State University Medical Center search and more info website

4.5 /5 (2 votes)  

Rank 4.5 /5 (2 votes)
Relevant PhysicsForums posts

More news stories

New smartphone application improves colonoscopy preparation

The use of a smartphone application significantly improves patients' preparation for a colonoscopy, according to new research presented today at Digestive Disease Week (DDW). The preparation process, which begins days in ...

Cancer created 6 hours ago | popularity not rated yet | comments 0

Research examines new methods for managing digestive health

Research presented at Digestive Disease Week (DDW) explores new methods for managing digestive health through diet and lifestyle.

Cancer created 6 hours ago | popularity not rated yet | comments 0

New colonoscope provides ground-breaking view of colon

A ground-breaking advance in colonoscopy technology signals the future of colorectal care, according to research presented today at Digestive Disease Week(DDW). Additional research focuses on optimizing the minimal withdrawal ...

Cancer created 21 hours ago | popularity 5 / 5 (2) | comments 0

ASCO: combo antibody therapy effective for melanoma

(HealthDay)—Concurrent use of two immune checkpoint antibodies—ipilimumab and nivolumab—may be effective for the treatment of advanced melanoma, according to a proof-of-principal study presented in ...

Cancer created May 17, 2013 | popularity not rated yet | comments 0

Risk factors ID'd for poor cutaneous cell CA outcomes

(HealthDay)—The risks of metastasis and death associated with cutaneous squamous cell carcinoma (CSCC) are low, but significant, and risk factors for poor outcome include tumor diameter, invasion beyond ...

Cancer created May 17, 2013 | popularity not rated yet | comments 0 | with audio podcast


Consuming coffee linked to lower risk of detrimental liver disease, study finds

Regular consumption of coffee is associated with a reduced risk of primary sclerosing cholangitis (PSC), an autoimmune liver disease, Mayo Clinic research shows. The findings were being presented at the Digestive Disease ...

Ketamine shows significant therapeutic benefit in people with treatment-resistant depression

Patients with treatment-resistant major depression saw dramatic improvement in their illness after treatment with ketamine, an anesthetic, according to the largest ketamine clinical trial to-date led by researchers from the ...

New research identifies practice changes to improve value and quality of GI procedures

There are significant cost and risk factors associated with two procedures commonly used to diagnose or treat gastrointestinal problems, according to research presented at Digestive Disease Week (DDW).

New research identifies risks, interventions for children's GI health

An increasing number of U.S. children are experiencing gastrointestinal issues that require interventions to resolve, according to research presented at Digestive Disease Week (DDW).

US psychiatry gets makeover in new manual

The latest makeover to a massive psychiatric tome honored by some, reviled by others and even called the "Bible" of mental disorders is being released Saturday with a host of new changes.

New case of SARS-like virus in Saudi: ministry

A new case of the deadly coronavirus has been detected in Saudi Arabia where 15 people have already died after contracting it, the health ministry announced on Saturday on its Internet website.