Holm, F. | Search bioRxiv

bioRxiv2023

The CNS Microenvironment Promotes Leukemia Cell Survival by Disrupting Tumor Suppression and Cell Cycle Regulation in Pediatric T-cell Acute Lymphoblastic Leukemia

A major obstacle in improving survival in pediatric T-cell acute lymphoblastic leukemia is understanding how to predict and treat leukemia relapse in the CNS. Leukemia cells are capable of infiltrating and residing within the CNS, where they interact with the microenvironment and remain sheltered from systemic treatment. These cells can survive in the CNS niche, by hijacking the microenvironment and disrupting normal functions, thus promoting malignant transformation. While the protective effects of the bone marrow niche have been widely studied, the mechanisms behind leukemia infiltration into the CNS and the role of the CNS niche in leukemia cell survival remain unknown. We have identified a dysregulated gene expression profile in CNS infiltrated T-ALL and CNS relapse, promoting cell survival, chemoresistance and disease progression. Furthermore, we discovered that interactions between leukemia cells and CNS microenvironment induce epigenetic alterations, such as changes in gene regulation and histone modifications, including H3K36me3 levels. These findings can be utilized to predict CNS infiltration and CNS relapse, therefore avoiding overtreatment and adverse effects caused by CNS directed therapy. Additionally, the identified genetic drivers of disease progression can serve as a first step towards identifying therapeutic targets, to sensitize the CNS niche to current therapeutic strategies.

cancer biology↗

bioRxiv2021

Monitoring fish spawning sites in freshwater ecosystems using low-cost UAV data: A case study of salmonids in lakes in Iceland

Low-cost unmanned aerial vehicles (UAV), widely known as drones, have become ubiquitous and improved considerably in their technical capabilities and data quality. This opens new opportunities for their utilisation in scientific research that can help to reduce equipment and data collection costs. Remote sensing methods in ecological fieldwork can be a suitable approach to complementing, augmenting or even replacing certain aspects of fieldwork. In this study we tested the suitability of UAV for the detection of salmonid spawning grounds in two lakes in Iceland, Thingvallavatn and Ellidavatn. Salmonids are very susceptible to environmental changes, especially during embryonic development when highly oxygenated water flow and low temperatures are required. Monitoring the changes of the redd density over time will help understand the population dynamics of salmonid species and create strategies for species conservation. As part of this pilot study, we conducted aerial surveys during the spawning seasons in both locations in 2018 recording standard photographs in the visible spectrum (red, green, blue) to fully cover the respective areas of interest. Different flight altitudes were recorded to test the effects of image resolution on the final analyses. The images were then processed by applying standard remote sensing analyses in the software ENVI. The maximum likelihood classification combined with post-classification improvement methods resulted in satisfactory accuracies that are valuable for further monitoring efforts. From these findings we established a workflow that allows the implementation of UAV in ecological fieldwork for regular long-term observations. We discuss our experiences with regards to their utility, their limitations and identify future directions of research for implementing the potential that low-cost approaches have in supporting ecological studies of freshwater ecosystems.

ecology↗