Metcalfe, S. | bioRxiv Science

bioRxiv2023

Image-Based Assessment of Natural Killer Cell Activity against Glioblastoma Stem Cells

Glioblastoma (GBM) poses a significant challenge in oncology and stands as the most aggressive form of brain cancer. A primary contributor to its relentless nature is the stem-like cancer cells, called glioblastoma stem cells (GSCs). GSCs have the capacity for self-renewal and tumorigenesis, leading to frequent GBM recurrences and complicating treatment modalities. While natural killer (NK) cells exhibit potential in targeting and eliminating stem-like cancer cells, their efficacy within the GBM microenvironment is limited due to constrained infiltration and function. To address this limitation, novel investigations focusing on boosting NK cell activity against GSCs are imperative. This study presents two streamlined image-based assays assessing NK cell migration and cytotoxicity towards GSCs. It details protocols and explores the strengths and limitations of these methods. These assays could aid in identifying novel targets to enhance NK cell activity towards GSCs, facilitating the development of NK cell-based immunotherapy for improved GBM treatment.

cancer biology↗

bioRxiv2022

Genome-wide SNPs reveal the social structure and invasion pathways of the invasive tropical fire ant (Solenopsis geminata)

Elucidating invasion pathways of invasive species is often challenging because invasive populations frequently have low genetic diversity caused by genetic bottlenecks during introduction events. Genome-wide sequencing such as Restriction Site-Associated DNA Sequencing (RADseq) can overcome these challenges by generating thousands of genome-wide single nucleotide polymorphic (SNP) markers. The tropical fire ant, Solenopsis geminata, is a global invader with low genetic diversity in its introduced range, making RADseq one of the best available methods to investigate its population genetics. We used double digest RADseq to generate 3,834 SNPs to compare the genetic diversity of S. geminata in its introduced range to its most likely source of introduction, determined the invasion pathways among populations at an unprecedented level of detail for this species, and determined the social structure of S. geminata workers collected in 13 locations worldwide. We found that introduced S. geminata went through a strong genetic bottleneck. We also identified multiple secondary introduction events among S. geminata populations, indicating that the bridgehead effect is an important driver in the global spread of this species. We found that all colonies in the introduced range were polygyne (i.e., with more than one queen) which may increase their invasion success and potential to cause adverse effects.

genetics↗