IRE: Studying Cancer Before it Emerges

Pancreatic cancer does not appear suddenly, but develops through a multistep process involving well-defined precursor and precancerous lesions – stages that, in humans, remain largely undetectable through standard imaging. This progression can span years, in some cases over a decade, offering a critical yet elusive window for early detection.

“Pancreatic cancer development in mice closely mirrors the progression of the disease in humans”, Cristinziano points out. “In murine models, precancerous lesions appear in a time range that spans between the 12th and the 15th week”, she continues.

To capture this otherwise hidden phase, IRE researchers – Dr. Giulia Piaggio, Dr. Isabella Manni, and Dr. Giulia Cristinziano – perform imaging sessions. “Our mice are bioluminescent”, Cristinziano explains. “In this transgenic model, the transcription of the luciferase gene is specifically induced during the cell cycle by the transcription factor NF-Y. The mice carry the luciferase gene under the control of an NF-Y–responsive promoter, which is active in proliferating tissues such as bone marrow, spleen, teeth, and testes. In addition, they harbor a KRAS mutation that is specifically activated in the pancreas”.

As a result, while baseline luminescent signals are present in naturally proliferating tissues, a distinct increase in bioluminescence occurs when pancreatic cancer begins to develop, allowing researchers to monitor tumor progression in real time.

“We collect blood samples from mice at specific time points while simultaneously performing imaging sessions to monitor disease progression”, Cristinziano says. “This combined approach allows us to assess potential variations over time, particularly since the abdominal bioluminescent signal is expected to appear only in mice that develop tumors, and not in control models”.

Dr. Giulia Cristinziano (left) and Dr. Isabella Manni (right)

“We are, and will always be, deeply grateful to these mice, which enable us to study complex and aggressive diseases that would otherwise be far more difficult to investigate”, Cristinziano says.

“There is a great deal of legislation behind this” she explains, going on to describe that IRE follows what is known as the Three Rs principle.

“Replace, reduce, refine”, Cristinziano says. “Replace means that we try to avoid using animal models whenever possible, opting for alternative methods when they are available. Reduce – she continues – means that we always aim to limit and minimize, with the support of biostatisticians, the number of animals we use. Refine, on the other hand, refers to continuously improving experimental conditions to minimize animal suffering: veterinarians are always involved, and protocols are carefully adjusted so that, at the earliest signs of distress, the animal is humanely sacrificed”.

In complex and serious diseases such as cancer, there are often no viable alternatives. “We cannot eliminate the use of murine models, as they are the closest to humans and remain the only systems that allow us to fully understand how a disease evolves and how a drug behaves”, Cristinziano explains. “We simply cannot do without them”.