ABSTRACT
Cell migration has been a subject of study in a broad variety of biological systems, from morphogenetic events during development to cancer progression. In this work, we describe single-cell movement in a modular framework from which we simulate the collective behavior of glioblastoma cells, the most prevalent and malignant primary brain tumor. We used the U87 cell line, which can be grown as a monolayer or spatially closely packed and organized in 3D structures called spheroids. Our integrative model considers the most relevant mechanisms involved in cell migration: chemotaxis of attractant factor, mechanical interactions and random movement. The effect of each mechanism is integrated into the overall probability of the cells to move in a particular direction, in an automaton-like approach. Our simulations fit and reproduced the emergent behavior of the spheroids in a set of migration assays where single-cell trajectories were tracked. We also predicted the effect of migration inhibition on the colonies from simple experimental characterization of single treated cell tracks. The development of tools that allow complementing molecular knowledge in migratory cell behavior is relevant for understanding essential cellular processes, both physiological (such as organ formation, tissue regeneration among others) and pathological perspectives. Overall, this is a versatile tool that has been proven to predict individual and collective behavior in U87 cells, but that can be applied to a broad variety of scenarios.
ABSTRACT
KANSL2 is an integral subunit of the nonspecific lethal (NSL) chromatin-modifying complex that contributes to epigenetic programs in embryonic stem cells. In this study, we report a role for KANSL2 in regulation of stemness in glioblastoma (GBM), which is characterized by heterogeneous tumor stem-like cells associated with therapy resistance and disease relapse. KANSL2 expression is upregulated in cancer cells, mainly at perivascular regions of tumors. RNAi-mediated silencing of KANSL2 in GBM cells impairs their tumorigenic capacity in mouse xenograft models. In clinical specimens, we found that expression levels of KANSL2 correlate with stemness markers in GBM stem-like cell populations. Mechanistic investigations showed that KANSL2 regulates cell self-renewal, which correlates with effects on expression of the stemness transcription factor POU5F1. RNAi-mediated silencing of POU5F1 reduced KANSL2 levels, linking these two genes to stemness control in GBM cells. Together, our findings indicate that KANSL2 acts to regulate the stem cell population in GBM, defining it as a candidate GBM biomarker for clinical use. Cancer Res; 76(18); 5383-94. ©2016 AACR.
