Hello Nature readers,
This week, we learn that artificial intelligence can classify brain tumours during surgery, discover that engineered bacteria can boost immune activity inside solid tumours and hear that a copycat nutrient can starve pancreatic cancer.

AI classifies brain tumours mid-surgery

A deep-learning algorithm can classify brain tumours in less time than it takes to perform brain surgery. This could help physicians to decide how aggressive tumours are and how much tissue to remove, reducing the need for follow-up surgery. In tests, the algorithm, called Sturgeon, correctly categorized 45 out of 50 frozen tumour samples. In 25 real operations, it had a turnaround time of less than 90 minutes and got the diagnosis right in 72% of cases.

Fake nutrient starves pancreatic cancer

Researchers have slowed the growth and spread of pancreatic cancer in mice by introducing a chemical — 6-diazo-5-oxo-L-norleucine — that mimics the properties of the essential nutrient glutamine but can't be used as a source of fuel for the tumour. When pancreatic tumours can no longer metabolize glutamine, they turn to another nutrient: asparagine. So the researchers added the chemotherapy agent L-asparaginase to break down asparagine, further starving the tumour.

Bacteria paint a target on solid tumours

Scientists have used bacteria's natural talent for infiltration to send them inside solid tumours to tag the masses for destruction by chimeric antigen receptor (CAR) T cells. The bacteria used in the study, Escherichia coli, naturally wiggle inside solid tumours, whereas many immune cells, such as T cells, do not. Researchers engineered E. coli to release a protein inside the tumour that would recruit cancer-killing CAR-T cells to the site. The treatment decreased the volume of tumours in mice with models of breast cancer and colorectal cancer. However, tumours in humans are around 30 times the size of those in mice, so more testing is needed to find out whether the bacteria can penetrate far enough inside them to make treatment effective.

Apply gel, prevent skin cancer?

A common type of skin cancer called squamous cell carcinoma could be prevented with a topical gel that inhibits the action of the MEK protein. In a mouse study, the NFX-179 gel reduced the development of new skin cancers by 60% compared with controls, with no side effects.