New method for mapping cancer paves the way for treatment of incurable brain cancer in children

Children diagnosed with brain cancer often die within a year of their initial diagnosis because there are no effective treatments for this rare form of cancer. But by visualizing the cancer cells, researchers have now gained a better understanding of what the tumors look like. The hope is that it will lead to new treatment methods. This is shown by a study with researchers at, among others, Stockholm University and SciLifeLab, recently published in Nature Genetics.

Through visualization, maps of tissue sections from a dozen or so tumors are created to see how the cells identified in the study are organized in the tumor tissue. Here a cell map of a 2x1.5 mm tumor section. Photo: Mats Nilsson

- The problem with these types of tumors is that the cancer cells in them are very malleable. They have an ability to change shape into cells that resemble completely normal cells, says Mats Nilsson, professor at the Department of Biochemistry and Biophysics at Stockholm University and SciLifeLab and co-author of the study.

Creates maps

The article is a comprehensive survey of the cellular and spatial variation of a brain cancer that mainly affects children and young people. The shape of the cells is controlled, among other things, by the local cellular environment.

- By mapping the cells' environments, we gain a better understanding of the circumstances under which the cells divide and thus also how we can try to disrupt this. Our part of the work at Stockholm University and SciLifeLab concerned the spatial part. We have created maps of tissue sections from a dozen tumors to see how the cells identified in the study are organized in the tumor tissue, says Mats Nilsson.

Why so difficult to treat

The study, which is the first to use so-called spatially resolved omics to analyze the tissues of cancer patients, maps how the cancer cells look molecularly and how they are organized spatially in the tumors in relation to each other and to more normal cells. The aim was to look for age- and site-dependent differences in the tumors, which came from different parts of the brain and the study was done by measuring all genetic activity in tissue samples from 50 people aged 2-68 years old. The researchers then discovered that the spatial organization of cells, i.e. how the cells are placed in relation to each other, can help explain why this particular form of cancer is so difficult to treat.

- With a better understanding of what it is that controls the cancer cells to resemble normal cells, you can try to develop treatment strategies that prevent them from being transformed in that way, says Mats Nilsson.

The study

Here is the study in Nature Genetics ”The landscape of tumor cell states and spatial organization in H3-K27M mutant diffuse midline glioma across age and location”

Facts SciLifeLab

SciLifeLab, which is a collaboration between Karolinska Institutet, KTH, Stockholm University and Uppsala University, is a national center for large-scale life science research with an advanced technological infrastructure. At SciLifeLab, multidisciplinary research is carried out based on DNA sequencing, gene expression analysis, proteomics, bioinformatics, biostatistics and systems biology. The aim is to make it possible for Swedish researchers to analyze genes, transcripts and proteins in different organisms with the intention of clarifying molecular mechanisms related to health and the environment.

Facts the method 3-dimensional resolved omics

The collaboration at SciLifeLab between three large universities makes it possible to use advanced technology in many different research areas. Spatial, or 3-dimensional resolved omics (spatial omics) is a rapidly growing field that provides new insights into the spatial organization of tissues and organs at the molecular level. The Targeted Spatial Omics (TSO) units within the SciLifeLab Spatial and Single Cell Biology platform are tasked with providing in situ sequencing (ISS), single-molecule fluorescence in situ hybridization (smFISH) and multiplexed immunofluorescence (CODEX) to researchers across the country. Techniques that make it possible, through 3-dimensional mapping of, for example, the cells in a tumor and which molecules they contain, to get a better picture of how they are organized and what environment they are in.