Nanoscale characterization of drug-induced microtubule filament dysfunction using super-resolution microscopy

Ashley M Rozario; Sam Duwé; Cade Elliott; Riley B Hargreaves; Gregory W Moseley; Peter Dedecker; Donna R Whelan; Toby D M Bell

doi:10.1186/s12915-021-01164-4

Nanoscale characterization of drug-induced microtubule filament dysfunction using super-resolution microscopy

BMC Biol. 2021 Dec 11;19(1):260. doi: 10.1186/s12915-021-01164-4.

Authors

Ashley M Rozario¹, Sam Duwé², Cade Elliott¹, Riley B Hargreaves¹, Gregory W Moseley³, Peter Dedecker⁴, Donna R Whelan⁵, Toby D M Bell⁶

Affiliations

¹ School of Chemistry, Monash University, Clayton, 3800, Australia.
² Biomedical Research Institute, Hasselt University, 3590, Diepenbeek, Belgium.
³ Department of Microbiology, Monash Biomedicine Discovery Institute, Clayton, 3800, Australia.
⁴ Department of Chemistry, KU Leuven, 3001, Leuven, Belgium.
⁵ La Trobe Institute for Molecular Science, La Trobe University, Bendigo, 3552, Australia. d.whelan@latrobe.edu.au.
⁶ School of Chemistry, Monash University, Clayton, 3800, Australia. toby.bell@monash.edu.

Abstract

Background: The integrity of microtubule filament networks is essential for the roles in diverse cellular functions, and disruption of its structure or dynamics has been explored as a therapeutic approach to tackle diseases such as cancer. Microtubule-interacting drugs, sometimes referred to as antimitotics, are used in cancer therapy to target and disrupt microtubules. However, due to associated side effects on healthy cells, there is a need to develop safer drug regimens that still retain clinical efficacy. Currently, many questions remain open regarding the extent of effects on cellular physiology of microtubule-interacting drugs at clinically relevant and low doses. Here, we use super-resolution microscopies (single-molecule localization and optical fluctuation based) to reveal the initial microtubule dysfunctions caused by nanomolar concentrations of colcemid.

Results: We identify previously undetected microtubule (MT) damage caused by clinically relevant doses of colcemid. Short exposure to 30-80 nM colcemid results in aberrant microtubule curvature, with a trend of increased curvature associated to increased doses, and curvatures greater than 2 rad/μm, a value associated with MT breakage. Microtubule fragmentation was detected upon treatment with ≥ 100 nM colcemid. Remarkably, lower doses (< 20 nM after 5 h) led to subtle but significant microtubule architecture remodelling characterized by increased curvature and suppression of microtubule dynamics.

Conclusions: Our results support the emerging hypothesis that microtubule-interacting drugs induce non-mitotic effects in cells, and establish a multi-modal imaging assay for detecting and measuring nanoscale microtubule dysfunction. The sub-diffraction visualization of these less severe precursor perturbations compared to the established antimitotic effects of microtubule-interacting drugs offers potential for improved understanding and design of anticancer agents.

Keywords: Antimitotic; Colcemid; Filament curvature; Live cell imaging; Microtubules; SOFI; Super-resolution; dSTORM.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Cytoskeleton*
Demecolcine / pharmacology
Microscopy, Fluorescence
Microtubules*

Substances

Demecolcine