EARA Newsletter

October 20th 2025

EARA News Digest 2025 - Week 43

Welcome to your Monday morning update, from EARA, on the latest news in biomedical science, policy and openness on animal research.

This week: Sour environment helps pancreatic cancer in mice thrive; Families discover research at the BPRC during the Dutch Weekend of Science; Keto diet prevents mood disorders in rats; Organoids mimic key kidney functions.

Sour environment helps pancreatic cancer in mice thrive

Researchers in Germany and Austria have discovered that the acidic environment inside tumours plays a key role in promoting cancer survival and growth.

The tumour environment is harsh and sour, often deprived of oxygen and nutrients and filled with waste products. These conditions make it difficult for other cells to survive, yet cancer cells manage to thrive.

Scientists from German Cancer Research Center (DKFZ) in Heidelberg and the Institute of Molecular Pathology (IMP) in Vienna investigated how pancreatic cancer cells adapt their metabolism to cope with acidic environments (acidosis).

Wilhelm Palm, researcher at the DKFZ and co-leader of the study published in Science, said: “It is not just the lack of oxygen or nutrients that changes metabolism in the tumour – it is primarily the acidification of the tumour environment.”

When the cancer cell environment turned acidic, mitochondria fused into long networks by blocking a metabolic pathway called ERK, boosting their energy efficiency. In normal conditions, ERK induces mitochondria to divide.

Through CRISPR-Cas9 gene editing, scientists identified essential genes for pancreatic cancer cell growth under stress — including acidic conditions — in lab-grown cells, later confirmed in mice. When the scientists used ERK to prevent the mitochondria fusion, tumour cells in mice with pancreatic cancer lost their capacity to adapt to the stressful acidic environment, growing more slowly.

The other co-lead author from IMP, Johannes Zuber, said: “Acidosis equips cancer cells with metabolic superpowers that help them survive not only harsh conditions but also treatment stress. With that knowledge, we can now search for therapies under these more realistic conditions and explore new ways to break this resilience.”

Families discover research at the BPRC during the Dutch Weekend of Science

The Biomedical Primate Research Centre (BPRC), an EARA Member in Rijswijk, the Netherlands, hosted around 100 visitors during the Dutch Weekend of Science.

The Weekend of Science (in Dutch: Weekend van de Wetenschap) took place on 4 and 5 October and is aimed at 8 to 18 year olds. On 5 October, BPRC opened its doors to give visitors a closer look at the work of researchers, how monkeys are cared for and the role they play in biomedical studies. Scientists, caretakers, veterinarians, the colony manager and students guided guests through interactive activities, including pipetting, observation experiments, measuring heart rates and performing a simple DNA test.

Lise visited BPRC with her family today: “I think it’s important for children to learn about science and the ethical dilemmas that sometimes come with it.”

Merel Langelaar, director of BPRC: “It’s wonderful to be able to open our doors like this. We’re happy to show what kind of research we do and how we do it. Because by being open about research involving animals, we show that there’s nothing secretive about it at all.”

Keto diet prevents mood disorders in rats

Researchers in Italy have discovered that feeding young rats a high-fat, low-carbohydrate (ketogenic) diet protected them from behavioural effects of prenatal stress, suggesting that changing nutrition could prevent mood disorders.

It’s known that stress experienced by mothers during pregnancy can have lasting psychological and developmental effects on their offspring.

Researchers from EARA member University of Milan exposed rats to stress during the last week of their pregnancy. As soon as the offspring were weaned, they fed them either a control or a ketogenic diet.

After six weeks, the researchers analysed their sociability and depression-like signs, such as spending less time grooming. Half of the control rats showed stress-related issues later in life, compared with only 22% of males and 12% of females fed a ketogenic diet.

“If these findings translate to humans, we may be able to treat the long-term burden of prenatal trauma simply by adjusting what at risk kids eat,” said Alessia Marchesin, researcher at University of Milan and leader of the unpublished work presented at the ECNP conference in Amsterdam.

Aniko Korosy, from the University of Amsterdam and not involved in the study, agreed that this was a good contribution to the field of nutritional psychiatry while highlighting that more studies are needed to understand which nutrients are involved in mental health effects.

Organoids mimic key kidney functions

Researchers in the US have developed lab-grown kidneys (organoids) that, for the first time, could produce urine when transplanted into mice.

Organoids are 3D cell cultures that mimic some features of human or animal organ tissues. Even though sometimes described as mini-organs, they are not complete or functional organs, lacking proper structure.

A study from the University of Southern California developed mouse kidney organoids that can mimic complex structures and produce urine – a key function of the kidney.

The team used mouse stem cells grown in a mixture of compounds that supported kidney organoid development and complex maturation. They also generated human kidney organoids, albeit not mature enough to produce urine.

However, when the researchers created organoids from human stem cells carrying kidney disease mutations and then transplanted them into mice organoids, these developed disease characteristics, demonstrating the potential to study human disease in animal organoids.