Imaging Small Animals in Real Time

Using a new tool in the Molecular Imaging Laboratory (MIL), researchers can study in real time how cholesterol affects tumor progression in breast cancer.

You probably are aware that high blood cholesterol levels can cause problems in your arteries, leading to heart disease, a heart attack, or a stroke.

But are you aware of other effects of cholesterol, including impact on tumor progression in certain cancers?

Using a new tool in the Molecular Imaging Laboratory (MIL), Erik Nelson, assistant professor of molecular and integrative physiology, studies how cholesterol affects tumor progression in breast cancer.

“It’s a really good way of tracking, in my field for example, whether your cancer is growing, or whether it’s spreading to different organs.”--Erik Nelson, assistant professor of molecular and integrative physiology

“There’s pretty strong clinical data showing that breast cancer patients who have either elevated cholesterol in their diet or elevated circulating levels of cholesterol have a poor prognosis for the progression of the disease,” said Nelson. “Cholesterol can also be a risk factor for the onset of disease.”

New Imaging Tool

Erik Nelson

The MIL, part of the Biomedical Imaging Center at Beckman, recently acquired a PerkinElmer IVIS Spectrum CT live-animal imaging system. Collective cross-campus contributions from the Office of the Vice-Chancellor for Research, Beckman Institute, several colleges, departments and individual principal investigators made the purchase possible. The IVIS system is the only in vivo small animal dedicated imaging system on the market that supports both 3D optical and x-ray computed tomography (CT), which allows for both functional and anatomical imaging.

“This is an imaging machine that allows you to detect bioluminescence or fluorescence, and the real advantage of it is you can image small animals while they are still alive, in real-time, and you can image luminescence or fluorescence throughout their entire body,” explained Nelson. “It’s a really good way of tracking, in my field for example, whether your cancer is growing, or whether it’s spreading to different organs.”

Preventing Cancer Metastasis

Nelson is looking at how statins, drugs that limit the production of cholesterol such as Lipitor or Crestor, can be used as either a treatment or to prevent cancer metastasis. His study is funded by the National Cancer Institute.

“A machine like the IVIS is great because otherwise we’d have no way to track our cells or track  how fast the cells are growing until necropsy (after the animals are humanely euthanized),” said Nelson. “The only alternative to the IVIS is basically to do terminal assays, and that makes it impossible to track the same tumor growth through time.”

IVIS allows the researchers to examine the cells as they grow and spread. Using the CT scanner on top of the IVIS scan provides for a 3D image, which can give more detail as to the exact location of the cancer cells.

“For a lot of my work, we’re looking at metastasis to the bone, so we can see exactly if these cancer cells are on top or inside the bone,” said Nelson.

The IVIS system complements other non-invasive in vivo imaging tools within MIL such as positron emission tomography (PET) and single photon emission computed tomography (SPECT) scanners.

“The IVIS provides our users with an outstanding imaging tool using integrated optical and X-ray microCT technology,” said Iwona Dobrucka, senior research scientist. “We can not only detect fluorescence and bioluminescence with an excellent sensitivity but also use x-ray imaging in order to locate optical signals in relation to animal anatomy. Through interfacing the IVIS system with existing nuclear imaging scanners such as PET and SPECT, we became a unique highly specialized facility, which allows for multimodal non-invasive monitoring of living organisms. Such multipurpose systems are in use only in best cancer research facilities, so we’re glad that we can provide this service to our users.”

This article is part of the Fall 2016 Synergy Issue, a publication of the Communications Office of the Beckman Institute.