Anton Berns: ‘Eliminating animal testing entirely is a pipe dream’

Over the long course of his career, Professor Anton Berns has made a name for himself in cancer research. Many of his successful studies were conducted using Petri dishes. Still, he feels that his most important work would have been impossible without lab animals and, views research that completely avoids the use of animals as infeasible. Why? ‘The human organism is too complex.’

‘The minute we want to involve lab animals, we encounter quite a bit of regulatory pressure and extremely high costs. So if we decide to pursue it anyway, we definitely have good reasons for doing so’, Berns explains in his office in Amsterdam, at the Netherlands Cancer Institute Antoni van Leeuwenhoek. ‘Scientists don't choose animal testing because it's easier or cheaper than the alternatives.’

Portretfoto Anton Berns, kankeronderzoeker
Anton Berns


‘For cancer research, you can grow tumour cells in a Petri dish. Yet the actual disease is infinitely more complex than that. The most successful – though still imperfect – treatment method we've come up with so far, immunotherapy, was made possible by research involving animal testing. That research taught us the general principles of how the immune system works. It is a pipe dream to think we can ever dispense with animal testing when we're still eager to understand this in greater detail. Something like the function of the immune system can only be replicated in a Petri dish in an extremely limited fashion.’

‘There are a great many things we scientists simply don't understand’

It is clear that Berns is passionate about the subject. ‘We mustn't underestimate the complexity of the human organism. That's something I want to explicitly warn against in the discussion on eliminating animal testing. Our ability to sequence the human genome is a phenomenal accomplishment. But how do genes work, exactly? We can only answer around 20% of that question, at most. There are a great many things we scientists simply don't understand. A cell culture lets you define the scope of your question in order to find out what you need to know. You consciously exclude many aspects from consideration, which you'll then need to study and understand in context later on. That means research involving a living organism, first lab animals and ultimately people.’


‘Anything that doesn't have to be done in vivo, we're already doing in vitro. But in many cases, whatever we find in vitro will still have to be tested in vivo. In cancer research, 99% of that testing is carried out on mice. Berns also sets much store by the three Rs: refine, reduce and replace. ‘For our part, we're very aware of the pressure to handle animal testing with care. Because not only are animal trials exorbitantly expensive, the culturing and testing on animals is a very slow process as well. Not to mention that the ethical considerations of the committees – who enforce strict standards with regard to the well-being of a carefully determined number of lab animals – are also shared by scientists.’


‘No other country in the world is as protective of lab animals as the Netherlands. Researchers conducting animal testing here have considerably less leeway than your average recreational angler.’ Fortunately, Dutch policy is not aimed at mandating the total elimination of animal testing. According to Berns, that would effectively drive scientists across the border. On top of which, the rules governing the use of lab animals are more lenient in most other countries.

‘We're getting better at extracting information from animal studies all the time’

Berns asserts that there's progress to be made if policymakers will focus their attention on adjusting the guidelines for testing some biotechnological products on animals, in connection with safety and potential side effects, before those products are approved for use in humans. This was among the recommendations made by the Royal Netherlands Academy of Arts and Sciences (KNAW) several years ago. A portion of these tests was revealed to have little added value.

Increasingly valuable

Berns sees animal testing as something we're unlikely to be able to do without. ‘To which I'd especially like to add that animal testing is becoming increasingly valuable, as we're getting better at extracting information from these studies all the time. The use of CRISPR/Cas9 technology has also made it considerably more efficient to genetically modify animals. As a result, we're able to obtain more effective lab animals, faster; generally speaking, it takes fewer generations to produce a cohort of animal subjects with the desired genetic modifications. Our analysis techniques are becoming more advanced as well. Consider, for instance, intra-vital imaging, in which we look through a window in a mouse's skin to follow – live – what happens in a tumour, such as how the mouse's immune cells move within the tumour and interact with tumour cells. Not only that, but our ability to process and interpret the data we obtain continues to expand. As a result, I don't expect animal trials to become any less relevant, or less common for that matter.’