Bizarre CRISPR enzyme shreds DNA inside cancer cells

Hello Nature readers,
This week, we hear that a peculiar type of CRISPR enzyme is being used to treat tumours in mice, discover that some catfish have a contagious cancer and learn that AI-generated physicians are spreading misinformation online.

Catfish catch cancer from one another

The mystery disease that’s been plaguing the brown bullhead catfish (Ameiurus nebulosus) in a lake straddling the Canada–US border has been identified as a type of transmissible cancer — a phenomenon rarely seen in the animal kingdom. Surveys have suggested that the disease, a type of melanoma that manifests as inky black skin lesions, affects around one-third of the lake’s catfish population. But it appears in both young and old individuals, suggesting that it might not cause a rapid death.

Bizarre CRISPR enzyme shreds cancer DNA

A peculiar type of CRISPR enzyme that slashes DNA into pieces has been used to control cancer in mice. The enzyme, called Cas12a2, can be engineered to recognize a particular RNA sequence. When it finds its target, the enzyme goes wild, indiscriminately cutting up DNA. Two separate research teams have used the CRISPR enzyme to target RNA made by cancer cells with mutated TP53 or KRAS genes. The treatment killed a proportion of lab-grown cancer cells and shrank tumours in mice. “There’s obviously still room to improve it,” says cancer geneticist Rene Bernards. “There is a lot of promise.”

AI-generated doctors mislead on TikTok

Artificial-intelligence-generated videos of fake doctors sharing misinformation about cancer have been viewed millions of times on the social media platform TikTok. Some videos state that sleeping next to a phone, microwaving food in plastic and using deodorants could cause cancer — claims that aren’t backed by evidence. Other videos promoted non-existent or ineffective remedies. “Platforms like TikTok must do more to stop the rise of dangerous fake medical advice … otherwise, it is the public who could be paying the price with their health and perhaps even their lives,” says physician Emma Runswick, the council deputy chair at the British Medical Association.

Vaccine might intercept pancreatic cancer

A vaccine that targets six KRAS mutations might stop pancreatic cancer before it fully develops. In a first-in-human study, 20 people with a genetic predisposition to pancreatic cancer and an abnormality in their pancreas were given the vaccine. None of the trial participants developed pancreatic cancer over a median of 17 months and the vaccine triggered a significant KRAS-specific immune response in 18 of them. Around 10% of people who develop pancreatic cancer have a genetic predisposition to the disease and might benefit from interception.

Creatine charges up the immune system

Supplementation with creatine — an amino acid derivative used by muscles to generate energy — can enhance the activation of immune cells called dendritic cells and suppress melanoma growth in mice. “What this study shows is that creatine doesn't just help the T cells fighting cancer – it also energizes the entire infrastructure that supports and guides them,” says immunologist and study co-author Lili Yang. “That makes creatine a promising supplement to holistically support the immune response that modern immunotherapies depend on.” It is too soon, however, to base dietary or medical advice on the conclusions, the authors say.

How genetics set the stage for cancer

Whether mice respond to environmental exposures by developing mutations and cancers strongly depends on their genetic makeup at birth. Researchers bred four strains of mice with different levels of genetic susceptibility to liver cancer and then exposed them to the same carcinogen. The rate and progression of liver cancer was strongly influenced by the animals’ genetic background. The research might help explain why some people develop cancer when exposed to carcinogens such as cigarette smoke while others don’t.

The cancer-Alzheimer’s paradox

The curious inverse correlation between cancer and Alzheimer’s disease provides a world of opportunity to find novel targets for both diseases, argues aging researcher Rebekah Feng, who lost her husband to glioblastoma at 46. Despite many shared risk factors, the likelihood of cancer in those with Alzheimer’s disease is halved and the risk of Alzheimer’s in those with cancer drops by 25-35%. Feng argues that this paradoxical relationship could be used to foster “transformative innovation”, which “ is not merely an aspiration but an urgent necessity”.

TriNetX data is being misused

Inexperienced researchers seem to be using an easy-to-access health dataset called TriNetX and large language models to churn out low-quality research papers, say scientists. The studies often fail to account for major sources of bias, which can make treatments such as cancer therapies look more effective than they really are. “My biggest concern is that doctors in 10 years’ time want to look into a particular concept and they go into the literature and everything is just associated with everything,” says neuroscientist Joshua Wang.