A team of Guelph researchers are working to create faster and more accurate blood tests for both dogs and humans battling bone cancer.
“We’re looking for a better way to predict how well dogs and people respond to treatment for osteosarcoma and how quickly they may have recurrence in the form of metastasis,” said pathobiology professor Geoffrey Wood.
Wood co-founded the Dog Osteosarcoma Group – Biomarkers of Neoplasia (DOGBONe) alongside biomedical sciences professor Alicia Viloria-Petit back in 2017, after they and a number of cross-disciplinary researches started collaborating on comparative osteosarcoma research.
Osteosarcoma is a type of bone cancer common in dogs and rare in humans, typically found in long bones like legs.
While human patients are typically adolescent, in dogs it’s usually found in older large and giant breeds.
It’s about 10 times more common in dogs than humans, and is also more aggressive, giving dogs a shorter survival time, just like in most other canine cancers.
“Dogs are kind of a natural model for the worst of the human disease,” he said, which is what makes early detection so important.
Knowing how likely the dog is to survive early on can help pet owners decide what treatment to pursue to ensure the best quality of life.
While it’s a well-known cancer – the same cancer Terry Fox was famously diagnosed with – there haven’t been any major advances in decades.
The group of 11 researchers includes veterinary oncologists, human oncologists and basic science researchers, along with a number of students in each lab.
It started with research comparing human and dog osteosarcoma gene deletions and amplifications and using mouse models, but they eventually started making their own cell lines (a population of cells grown in a lab from one cell) from dogs with osteosarcoma.
This is beneficial for a number of reasons, one being that osteosarcoma doesn’t occur naturally in mice, so mouse models are genetically engineered.
“So it’s not a realistic tumour, compared to people,” he said.
The research focused on dogs, instead, includes samples from real pet patients coming into the OVC to be treated for the cancer.
“Mice are experimental. The dogs are patients. They come here with the disease as humans come with the disease to a hospital,” she said.
Dogs are also closer to humans than mice in terms of evolution, which makes the likelihood higher for a similar response.
Because of this, many studies have been done where something works in mice but doesn’t translate to humans.
“But if something works in dogs, there is more probability it will work in humans and vice-versa,” she said. “Therefore, when you find something for one species, you may be advancing both sides of veterinary and human medicine.”
While it’s not overly common, similar comparative oncology research is being done throughout the university and in a number of universities within the U.S.
Most have a specific focus, however. For DOGBONe, that focus is on biomarkers.
Most biomarkers require a tissue biopsy, which is hard to do and follow up.
Biomarkers could be proteins and genes that can show things like disease presence, progression, and response to treatment.
Biomarkers can be found in blood, and are minimally invasive.
A lot of biomarkers need a tissue biopsy, which is hard to do and follow up.
For example, it can show whether a patient’s cancer is metastasizing.
“So we are trying to find those biomarkers that can detect early use by a blood sample that the dog is prone to metastases, so we can treat them earlier, and they don’t get to a super advanced stage,” she said. “Hopefully that will increase both the quality of life and the length of life.”
In dogs, they’ve found some molecules in blood (microRNA) correlate with longer or shorter survival times after treatment.
“So that’s what we’re looking at now, are these same microRNA in human blood samples at the time of diagnosis? Does that predict how long until they get metastases?” he said.
They’re now working with biomedical engineer Huiyan Li to create a lab-on-a-chip detection system to measure key molecules in human blood.
The system allows them to analyze a number of molecules using only a small amount of blood, and can be read with equipment they already have on-hand.
They plan to create one for microRNAs and another for proteins found in extracellular vesicles, which are essentially bubbles released by the cells that hold biomolecules of the cells they were released from.
Since they’re found in blood, DOGBONe is working on capturing them from the blood and identifying proteins they carry that have information about the tumour.
“We’re doing this over time to see if the proteins that we get from these bubbles can tell us that there is going to be metastatic disease before the X-ray in the lungs,” she said.
The result would be a faster and less invasive way to determine how probable a relapse is, and act faster with treatment options.
It’s also less risky for dogs, “because you don’t want to be doing X-rays or CT Scans to the dog over and over – it’s a lot of radiation for them.”
Plus, it would mean not having to repeatedly subject the dog to radiation-based testing, or testing that uses anesthesia, making the process safer and potentially cheaper.
The microRNA they’re looking into can also be found in the bubbles.
Trials on dogs have been approved, and the team is in the process of collecting samples to begin.
But it’s going to be a long process ahead.
“It takes time because you need to get a robust number of dogs to get some statistical significance of the data you’re obtaining,” she said.
The goal is to eventually repeat the process in humans.
As they continue the process, they hope to find new, more effective therapies to target the cancer in both humans and dogs.
