Menu

How Exercise Might Fight Cancer

Epinephrine’s activation of the signaling pathway Hippo is responsible for the in vitro tumor-fighting effects of serum from women who worked out.

Sep 8, 2017
Jef Akst

FLICKR, ALEXANDRA E RUSTResearchers have long recognized an epidemiological link between exercise and a lower risk of certain cancers, including breast cancer. But experimental evidence nailing down a molecular mechanism for this effect has been lacking. Now, Pernille Hojman of Copenhagen University Hospital in Denmark and colleagues have found a possible clue: epinephrine activation of the Hippo signaling pathway.

Last year, Hojman and colleagues analyzed factors in the blood serum of women who’d survived breast cancer before and after two hours of moderate to intense exercise, identifying increases in lactate, epinephrine, norepinephrine, and certain cytokines. As had previously been noted, the blood drawn after exercise reduced the viability of breast cancer cells in culture. To determine which of these molecules might be responsible, the team examined the blood of seven healthy women and 20 women being treated for early-stage breast cancer, before and after two hours of exercise.

Confirming prior results, the researchers found that blood drawn after exercise thwarted the growth of breast cancer cells in culture, compared with blood drawn before exercise. In addition, mice injected with breast cancer cells that had been exposed to post-exercise serum were less likely to develop tumors. But both of these effects were reduced if the researchers blocked epinephrine from binding to its receptor and activating a tumor-suppressor signaling pathway known as Hippo on the breast cancer cells.

“The results of this study show that moderate to high intensity exercise leads to an acute increase in levels of epinephrine, which can reduce breast cancer cell viability and tumor growth via activation of the Hippo signaling pathway,” Hojman says in a press release. The findings were published today (September 8) in Cancer Research.

See “Running from Cancer?

The results only applied to one breast cancer cell line, called MCF-7, of two lines tested. In the second, called MDA-MB-231, epinephrine did not activate the Hippo signaling pathway, and blocking epinephrine binding did not reduce the effects of post-exercise serum exposure on the cells’ growth. “MCF-7 cells are hormone receptor–positive and MDA-MB-231 cells are triple-negative,” Hojman explains in the release. “There are epidemiological data that suggest that exercise might be better at reducing the risk of recurrence of hormone receptor–positive breast cancer compared with triple-negative breast cancer, which might explain why the effects of serum obtained after exercise were more pronounced on MCF-7 cells. In addition, these cell lines differ in which mutations they carry, and the difference in the exercise effect might be a result of this.”

Many questions remain about the role of exercise in determining cancer risk. For example, studies have yielded mixed results about the importance of exercise itself, versus fitness overall. In Hojman’s 2016 study, the group found no effects of six months of training on serum’s ability to reduce breast cancer cell viability in culture. But in a study published this summer in Carcinogenesis, researchers showed that rats that had been bred to be innately more fit were about four times less likely to develop breast cancer than rats with low baseline fitness, demonstrating “the pervasive effects” of fitness on health, study coauthor Henry Thompson, director of the Cancer Prevention Lab at Colorado State University, tells The New York Times this week (September 6).

February 2019

Big Storms Brewing

Can forests weather more major hurricanes?

Marketplace

Sponsored Product Updates

Bio-Rad Showcases New Automation Features of its ZE5 Cell Analyzer at SLAS 2019
Bio-Rad Showcases New Automation Features of its ZE5 Cell Analyzer at SLAS 2019
Bio-Rad Laboratories, Inc. (NYSE: BIO and BIOb) today showcases new automation features of its ZE5 Cell Analyzer during the Society for Laboratory Automation and Screening 2019 International Conference and Exhibition (SLAS) in Washington, D.C., February 2–6. These capabilities enable the ZE5 to be used for high-throughput flow cytometry in biomarker discovery and phenotypic screening.
Andrew Alliance and Sartorius Collaborate to Provide Software-Connected Pipettes for Life Science Research
Andrew Alliance and Sartorius Collaborate to Provide Software-Connected Pipettes for Life Science Research
Researchers to benefit from an innovative software-connected pipetting system, bringing improved reproducibility and traceability of experiments to life-science laboratories.
Corning Life Sciences to Feature 3D Cell Culture Technologies at SLAS 2019
Corning Life Sciences to Feature 3D Cell Culture Technologies at SLAS 2019
Corning Incorporated (NYSE: GLW) will showcase advanced 3D cell culture technologies and workflow solutions for spheroids, organoids, tissue models, and applications including ADME/toxicology at the Society for Laboratory Automation and Screening (SLAS) conference, Feb. 2-6 in Washington, D.C.
Corning Introduces New 1536-well Spheroid Microplate
Corning Introduces New 1536-well Spheroid Microplate
High-throughput spheroid microplate benefits cancer research, drug screening