Page 8 - Clinical Connections - Spring 2022

RVC RESEARCH STUDY VETERINARY SERVICES RVC.AC.UK
Cancer Research

USING FLOW CYTOMETRY FOR COMPANION
ANIMAL CANCER RESEARCH

Dirk Werling, Professor of Molecular Immunology

ver the last two years, RVC’s labelled cells derived from bone marrow, thousands of cells per second), means
research facilities have been lymph nodes, or blood) is suspended in a clinical oncology patients and RVC clinicians
O revamped to stay at the cutting fluid and injected into the flow cytometer have their test results within hours. This
edge of changes in veterinary medicine. instrument. A system of tubing, pipes, and is a definite game-changer, particularly in
One of these changes is the greater impact valves forces the cells to pass through the cases where prompt treatment is needed to
of basic research and research equipment instrument in a single stream. ensure better outcomes, and it can be easily
to closer link research and clinical When cells reach the interrogation point used to run aside classical methods, such
diagnostics, whether this is on a large scale (or laser intercept), they pass through a as cytological assessment. Today, cancer
for farmed animals, or on a small scale focused laser beam or a similar light source, researchers commonly use a combination
for a ‘personalised medicine’ approach in causing fluorescence emission and light of fluorescent monoclonal antibodies with
companion animals. scattering. Fluorescence intensity indicates flow cytometry.
As part of the current investment of the the quantity of cellular constituents, while
Hawkshead Campus, with support from light scatter determines the size (forward Flow Cytometry and Cancer Research
Hertfordshire Local Enterprise Partnership angle scatter) and structure (right angle In human medicine, flow cytometry has
and the Animal Care Trust, we were able to scatter) of individual cells. The data is then become an essential component of the
purchase two flow cytometers, one of which collected and processed accordingly while assessment, diagnosis, and staging
is a fluorescence-activated cell sorter, and the cell sample is disposed of in the waste of cancer. Here, it is used primarily for
a new microscope, to enable researchers container. In a cell sorter, however, the cell immunophenotyping, which is the use of a
to perform live-cell imaging, as well as the sample is passed on to a collection tube for panel of antibodies to identify cell lineage,
multicolour ELISpot reader that allows post-experimental use. for example B or T cell lymphoma. The
precise enumeration of active immune cells. Flow cytometry allows researchers to range of immunophenotyping panels used
The Flow Cytology Core Facility is available simultaneously measure various parameters to assess neoplasia in relevant veterinary
to internal and external users. within these samples, which can include the species, such as cats and dogs, although
For over 30 years, flow cytometry has quantification of various cell populations and increasingly used in veterinary diagnostics
been used to advance the understanding the specific expression of tagged markers is still constrained because of associated
and diagnosis of cancer. As this technique present on the cell’s surface. However, expense and a limited availability of species-
evolves, researchers have been able it is not only the specificity that makes specific antibodies.
to utilise flow cytometry to study the flow cytometry such a powerful tool for In veterinary oncology, flow cytometry
development and progression of cancer to cancer diagnostics, but also its sensitivity. is most often applied to hemolymphoid
improve patient care and ultimately develop Researchers can detect the presence of a neoplasia, osteosarcoma and transitional
treatment options. small number of cancer cells even if other cell carcinoma. Immunophenotyping can
testing methods provide no evidence of the also play a pivotal role in the assessment
How does flow cytometry work? disease, for example it is possible to detect of canine leukaemia by defining the cell
Flow cytometry is a laser technology that as low as 1 in 10,000 (or even 70,000) cells. lineage, stage of maturation and prognostic
enables the user to quantitatively measure Thus, flow cytometry can be particularly information. This information is extremely
the physical and chemical properties within powerful in monitoring remission and relevant when it comes to fast decision
samples such as bone marrow, lymphoid predicting disease recurrence. making, resulting hopefully in a faster way
tissue or blood. This sensitivity, in connection with the to treatment and potentially the increase in
In this method, the sample (fluorescent- speed of analysis (flow cytometry analyses quality of life.

Images to right: Live-dead cell staining
by flow cytometry in a healthy individual
(bottom row) and a cancer patient (top row).
The most important image is the one on the
far top right, showing more dead cells in a
sample from a cancer patient compared to
that of a healthy patient

For small animal referrals, please call:
01707 666399
Email:
qmhreception@rvc.ac.uk
8 Spring 2022