Local anesthetics inhibit kinesin motility and microtentacle protrusions in human epithelial and breast tumor cells.
Detached breast tumor cells produce dynamic microtubule protrusions that promote reattachment of cells and are termed tubulin microtentacles (McTNs) due to their mechanistic distinctions from actin-based filopodia/invadopodia and tubulin-based cilia. McTNs are enriched with vimentin and detyrosinated α-tubulin, (Glu-tubulin). Evidence suggests that vimentin and Glu-tubulin are cross-linked by kinesin motor proteins. Using known kinesin inhibitors, Lidocaine and Tetracaine, the roles of kinesins in McTN formation and function were tested. Live-cell McTN counts, adhesion assays, immunofluorescence, and video microscopy were performed to visualize inhibitor effects on McTNs. Viability and apoptosis assays were used to confirm the non-toxicity of the inhibitors. Treatments of human non-tumorigenic mammary epithelial and breast tumor cells with Lidocaine or Tetracaine caused rapid collapse of vimentin filaments. Live-cell video microscopy demonstrated that Tetracaine reduces motility of intracellular GFP-kinesin and causes centripetal collapse of McTNs. Treatment with Tetracaine inhibited the extension of McTNs and their ability to promote tumor cell aggregation and reattachment. Lidocaine showed similar effects but to a lesser degree. Our current data support a model in which the inhibition of kinesin motor proteins by Tetracaine leads to the reductions in McTNs, and provides a novel mechanism for the ability of this anesthetic to decrease metastatic progression.
Marlene and Stewart Greenebaum Cancer Center, Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
Jennifer R
JR
Yoon
Rebecca A
RA
Whipple
Eric M
EM
Balzer
Edward H
EH
Cho
Michael A
MA
Matrone
Michelle
M
Peckham
Stuart S
SS
Martin
D000779:Anesthetics, Local / Q000494:pharmacology*; D001943:Breast Neoplasms / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology*; D002448:Cell Adhesion / Q000187:drug effects; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism; D005260:Female; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D016547:Kinesins / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism*; D008012:Lidocaine / Q000494:pharmacology; D042361:Mammary Glands, Human / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D013748:Tetracaine / Q000494:pharmacology; D014404:Tubulin / Q000378:metabolism; D014746:Vimentin / Q000378:metabolism
D000779:Anesthetics, Local; D014404:Tubulin; D014746:Vimentin; D013748:Tetracaine; D049452:Green Fluorescent Proteins; D008012:Lidocaine; D016547:Kinesins