Researchers at Purdue University have developed a new imaging technique that may help in understanding the development of breast cancer and maybe one day serve as an early screening test that predicts the progression of the disease. Called vibrational spectral microscopy, the method utilizes a laser to detect the vibrational frequency of molecules in a sample.
The technique was tested on a specially created “3D culture” that has physical properties similar to living mammary glands. Because it provides almost immediate results and works with live cells, the new imaging modality may be a hit with both research scientists and clinicians.
“This extremely sensitive technique shows the harmful impact of a nutrient called arachidonic acid,” said [Sophie] Lelièvre, associate director of Discovery Groups at the Purdue Center for Cancer Research. “This fatty acid has been previously proposed to increase breast cancer risk, but until now there was no biological evidence of what it could do to alter breast epithelial cells.”
The imaging method detects changes in the “basoapical polarity” of epithelial tissues. Specific proteins and other biochemical compounds called lipids are normally located in one of two regions, called the basal and apical membranes. Because only certain proteins and lipids are found in basal membranes, while others are located only in apical membranes, the cells are said to be polarized.
“This polarity is critical for the proper structure and function of tissue,” Lelièvre said. “What we have shown previously is that when polarity is altered, tissue that otherwise looks normal can be pushed into a cell cycle necessary to form a tumor. It’s the earliest change in the epithelial tissue that puts the cells at risk to form a tumor. Now, thanks to the vibrational spectral microscopy technique developed by Dr. Cheng, we can measure apical polarity status in live tissues and real time.”
The findings could lead to a method for preventing tumor formation by restoring the proper polarity.
“We are mimicking formation of breast epithelium as it is normally polarized, and we can play with it and make it lose apical polarity on demand,” Lelièvre said. “Then we can mimic an early change thought to be conducive to tumor development.”
The researchers aim to use the imaging technology on live 3-D cultures of noncancerous breast tissue to screen for protective and risk factors for breast cancer the same way that tumors are used now in cultures to screen for drugs that can be used for treatment.
Abstract in Biophysical Journal: Label-Free Analysis of Breast Tissue Polarity by Raman Imaging of Lipid Phase