New study: Aggressive breast cancer grows faster in obese environment

March 31, 2017 by Laura Oleniacz

It's not just what's inside breast cancer cells that matters. It's also the environment surrounding cancer cells that drives the disease, according to researchers at the University of North Carolina Lineberger Comprehensive Cancer Center.

In an abstract that will be presented April 3 at the American Association for Cancer Research Annual Meeting 2017, researchers will report their preliminary findings that grew faster when they were transplanted into fatty, obese tissue. They believe the study can help explain the obesity link, providing evidence that elements of the surrounding cancer cells may help the cancer to grow.

"We're interested in something called the 'microenvironment,' which is basically cells around the tumor and the chemicals those cells produce," said Liza Makowski, PhD, UNC Lineberger member and associate professor in the UNC Gillings School of Global Public Health. "In breast cancer, we know that the cancer is embedded in very fatty tissue, because the breast is made up largely of adipose tissue. As a person becomes obese, that can change the , or change this microenvironment where the cancer can start or progress."

For the study, researchers in the Makowski lab studied a type of breast cancer known as . Researchers transplanted and grew triple negative from lean laboratory models into models of obese, lean and formerly obese microenvironments to observe how tumors grew in these different contexts.

Tumors were significantly larger in the obese models than in the lean models, and larger than tumors in models that lost the weight. Their findings for the weight loss models suggest that weight loss corrected changes to the microenvironment that were helping drive the cancer.

When they analyzed the gene expression patterns occurring within the tumors themselves, they found that the alterations that occurred were "extremely subtle," Makowski said, and could not explain the dramatic tumor growth they saw in the obese mice.

"Where we saw the most changes were in the mammary glands around the tumors," said the study's first author Alyssa J. Cozzo, a graduate student in the UNC Gillings School of Global Public Health. "This implies that the microenvironment surrounding the tumor can be a driver of tumor growth, even when the and the other cells that make up the tumor itself are relatively similar."

Their findings have important implications for understanding the link between obesity and cancer.

"Our take-home message for this study was that, indeed, the obese microenvironment (the mammary gland surrounding the tumor) can drive even when the tumor cells come from a lean mouse, and, critically, the obese environment can be partially or completely reversed by ," Makowski said. "It's as if the cells do not 'remember' the obese exposure."

In a major symposium held from 1 to 2:45 p.m. Sunday at the AACR Annual Meeting called "Obesity, Inflammation, and the Adipose Microenvironment in Cancer," Makowski will be serving as chair. She will speak on the obesity-cancer link, and the role that immune cells surrounding tumors may play in also helping to drive the disease.

Explore further: Obesity found to be major risk factor in developing basal-like breast cancer

Related Stories

Obesity found to be major risk factor in developing basal-like breast cancer

November 18, 2013
Women who are obese face an increased risk of developing an aggressive sub-type of breast cancer known as 'basal-like', according to research conducted at the University of North Carolina.

Cancer stem cells in 'robbers cave' may explain poor prognosis for obese patients

July 20, 2016
Across many cancer types, obese patients fare worse than leaner patients. Now a University of Colorado Cancer Center study published in the journal Cell Stem Cell offers a compelling hypothesis why: researchers found that ...

Study supports link between obesity and higher incidence of cancer, poorer prognosis

October 15, 2012
Researchers may have discovered a new explanation as to why obese patients with cancer often have a poorer prognosis compared with those who are lean. The potential explanation is based on data reported in Cancer Research, ...

Silencing cancer cell communication may reduce the growth of tumors

January 30, 2017
In several types of cancer, elevated expression of the chemokine receptor CCR4 in tumors is associated with poor patient outcomes. Communication through CCR4 may be one mechanism that cancer cells use to create a pro-tumor ...

Fat cells may play key role in battle against breast cancer

July 13, 2016
New research led by York University Professor Michael Connor highlights how fat cells could help determine the most effective way to fight breast cancer; including using exercise to combat the disease.

Looking beyond cancer cells to understand what makes breast cancer spread

February 16, 2017
To understand what makes breast cancer spread, researchers are looking at where it lives - not just its original home in the breast but its new home where it settles in other organs. What's happening in that metastatic niche ...

Recommended for you

Breast cancer researchers find bacteria imbalance link

October 19, 2017
Researchers in the United States have uncovered differences in the bacterial composition of breast tissue of healthy women versus those with breast cancer.

New study reveals breast cancer cells recycle their own ammonia waste as fuel

October 19, 2017
Breast cancer cells recycle ammonia, a waste byproduct of cell metabolism, and use it as a source of nitrogen to fuel tumor growth, report scientists from Harvard Medical School in the journal Science.

US regulators approve 2nd gene therapy for blood cancer

October 19, 2017
U.S. regulators on Wednesday approved a second gene therapy for a blood cancer, a one-time, custom-made treatment for aggressive lymphoma in adults.

New findings explain how UV rays trigger skin cancer

October 18, 2017
Melanoma, a cancer of skin pigment cells called melanocytes, will strike an estimated 87,110 people in the U.S. in 2017, according to the Centers for Disease Control and Prevention. A fraction of those melanomas come from ...

Drug yields high response rates for lung cancer patients with harsh mutation

October 18, 2017
A targeted therapy resurrected by the Moon Shots Program at The University of Texas MD Anderson Cancer Center has produced unprecedented response rates among patients with metastatic non-small cell lung cancer that carries ...

Possible new immune therapy target in lung cancer

October 18, 2017
A study from Bern University Hospital in collaboration with the University of Bern shows that so-called perivascular-like cells from lung tumors behave abnormally. They not only inadequately support vascular structures, but ...

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.