In vivo microscopy reveals macrophage polarization locally promotes coherent microtubule dynamics in migrating cancer cells
Authors: Gaurav Luthria, Ran Li, Stephanie Wang, Mark Prytyskach, Rainer H. Kohler, Douglas A. Lauffenburger, Timothy J. Mitchison, Ralph Weissleder & Miles A. Miller
Microtubules (MTs) mediate mitosis, directional signaling, and are therapeutic targets in cancer. Yet in vivo analysis of cancer cell MT behavior within the tumor microenvironment remains challenging. Here we developed an imaging pipeline using plus-end tip tracking and intravital microscopy to quantify MT dynamics in live xenograft tumor models. Among analyzed features, cancer cells in vivo displayed higher coherent orientation of MT dynamics along their cell major axes compared with 2D in vitro cultures, and distinct from 3D collagen gel cultures. This in vivo MT phenotype was reproduced in vitro when cells were co-cultured with IL4-polarized MΦ. MΦ depletion, MT disruption, targeted kinase inhibition, and altered MΦ polarization via IL10R blockade all reduced MT coherence and/or tumor cell elongation. We show that MT coherence is a defining feature for in vivo tumor cell dynamics and migration, modulated by local signaling from pro-tumor macrophages.
Reference: Luthria, G., Li, R., Wang, S. et al. In vivo microscopy reveals macrophage polarization locally promotes coherent microtubule dynamics in migrating cancer cells. Nat Commun 11, 3521 (2020). https://doi.org/10.1038/s41467-020-17147-y
The authors used Bio X Cell’s anti-mouse CSF1R (CD115) (clone AFS98), anti-mouse IL-10R (CD210) (clone 1B1.3A), InVivoMAb anti-human EGFR (clone 225), InVivoPlus rat IgG1 isotype control (clone HRPN), and InVivoMAb mouse IgG1 isotype control (clone MOPC-21) in this research study.