JUL 17, 2017 3:41 PM PDT

Cancer Forces Cells to Become Virus-Like

WRITTEN BY: Xuan Pham

For a long time, scientists noticed that tumors secrete factors that suggest there were viruses present inside the tumors too. But even when they searched high and low, no viruses were found within the tumors. But a recent study has finally unveiled the mystery: cancer cells force nearby healthy cells to secrete viral-like proteins for its defense.

Image credit: Pixabay.com

"The conundrum was that in most cases, there was no viral infection in these tumors," said Andy J. Minn, an associate professor of Radiation Oncology at Penn, and the study’s senior author. "We've been studying this problem for many years, and it's a puzzle we were motivated to solve because cancers with this kind of anti-viral signaling can be particularly aggressive."

Minn and his team found that the cancer cells force surrounding fibroblasts to secrete vial-like genetic material inside small fluid-filled sacs known as exosomes. Specific to breast cancer cells, the fibroblasts were making exosomes rich in an RNA known as RN7SL1 , which resembles viral RNA at one end. With this viral-mimic exposed, the tissue responds as if there are viruses present, and this response can further enable the growth of the tumor.

"The ability of cancer cells to specifically instruct the fibroblasts to expose the viral-like end of RN7SL1 is a key discovery," said Minn. "If the end remains covered, breast cancer cells wouldn't treat these exosomes like a virus, making them less likely to progress and more likely to respond to treatment. On the other hand, if the end is always exposed, cells would react as if they are infected with a virus all the time."

The researchers think this manipulation of fibroblast cells could explain the inflammatory nature of some aggressive types of breast cancers. In particular, triple-negative and BRCA1 are two aggressive types of breast cancers that have high viral responses. Singling out the mechanism behind this response could lead to specific alternative treatments that improve the outcomes for these cancer types.

"Since we can test the blood of cancer patients to measure the presence of exposed RN7SL1 in exosomes, we can potentially identify patients whose cancers will be the most aggressive because of this virus mimic," Minn said. "Now that we understand how the exposed RNA is generated, we can look to potential therapeutic targets."

Additional source: Perelman School of Medicine at the University of Pennsylvania

About the Author
  • I am a human geneticist, passionate about telling stories to make science more engaging and approachable. Find more of my writing at the Hopkins BioMedical Odyssey blog and at TheGeneTwist.com.
You May Also Like
APR 11, 2021
Genetics & Genomics
Trial Shows Personalized Cancer Vaccines are Safe
APR 11, 2021
Trial Shows Personalized Cancer Vaccines are Safe
Vaccines are mostly known as tools to prevent illness. But cancer vaccines are a bit different, and aim to treat existin ...
APR 15, 2021
Cancer
What should breast cancer treatment in older women look like?
APR 15, 2021
What should breast cancer treatment in older women look like?
A new study published in JAMA Network Open by researchers at UPMC Hillman Cancer Center and the University of Pittsburgh ...
MAY 13, 2021
Cancer
Ovarian cancer screening doesn't save lives, reports new study
MAY 13, 2021
Ovarian cancer screening doesn't save lives, reports new study
New research published in the journal The Lancet highlights the eagerly awaited results of the UK Collaborative Trial of ...
JUN 14, 2021
Health & Medicine
Another Benefit of Aspirin: Decreased Colorectal Cancer Risk When Started Early
JUN 14, 2021
Another Benefit of Aspirin: Decreased Colorectal Cancer Risk When Started Early
Valued for stroke and heart attack prevention, aspirin is also recommended for colorectal cancer prevention. A Harv ...
JUN 22, 2021
Cancer
Evaluating adverse effects of induction therapy for neuroblastoma
JUN 22, 2021
Evaluating adverse effects of induction therapy for neuroblastoma
A study published in the Journal of Clinical Oncology reports an evaluation of the chemotherapy treatment given to child ...
JUL 08, 2021
Cancer
Activating p53 May Boost Efficacy of Cancer Immunotherapy
JUL 08, 2021
Activating p53 May Boost Efficacy of Cancer Immunotherapy
Pharmacological activation of the p53 protein in cancer cells leads to an anti-tumor immune response in lab tests. These ...
Loading Comments...