Pre-existing inflammation may promote the spread of cancer

In an article titled, "Allergen Induced Pulmonary Inflammation Enhances Mammary Tumor Growth and Metastasis: Role of CH13L1," featured on the cover of the current issue of the Journal of Leukocyte Biology, this new research suggests inflammation raises the level of a known biomarker of cancer, called "chitinase-3-like-1" or "CHI3L1," in the inflamed tissue, which leads to increased metastasis and faster cancer growth in that tissue. Metastasis is responsible for 90 percent of breast cancer deaths despite significant improvements in diagnosis and treatments.

"Important findings from our research show how pre-existing inflammation may be one of the factors that accelerates metastasis to the inflamed site," said Vijaya L. Iragavarapu-Charyulu, Ph.D., the principal investigator of the study and associate professor of biomedical science in FAU's Charles E. Schmidt College of Medicine. "This study may serve as a starting point for future research on how other inflammatory diseases may predispose patients for increased metastasis."

To make their discovery, Iragavarapu's team used two groups of mice, one of which was genetically modified so it could not produce the CHI3L1 glycoprotein. They then induced the two groups of mice to become asthmatic, after which the mice were challenged with breast cancer cells. After four weeks, researchers observed that there was less inflammation in the mice lacking CHI3L1 expression and that the tumors in these mice did not grow as fast. These mice also had less metastasis to the lungs.

"In this study, we found that CH13L1 was an important inflammatory protein that promoted tumor growth and metastasis, providing the necessary 'soil' or the proper environment for the 'seeds,' that is the circulating breast tumor cells," said Iragavarapu-Charyulu. "We are encouraged by the results of our study and hopeful that it will help us to better develop targeted therapeutics to treat cancer."