The Nek2 centrosome-mitotic kinase contributes to the mesenchymal state, cell invasion, and migration of triple-negative breast cancer cells

Yainyrette Rivera-Rivera,Mihaela Marina,Jaleisha Vélez Velázquez,Jaya Padmanabhan,Shirley Jusino,Srikumar P Chellappan,Miyoung Lee,Camille Chardón-Colón,Harold I Saavedra,Geraldine Vargas

doi:10.1038/s41598-021-88512-0

Abstract

Nek2 (NIMA‐related kinase 2) is a serine/threonine-protein kinase that localizes to centrosomes and kinetochores, controlling centrosome separation, chromosome attachments to kinetochores, and the spindle assembly checkpoint. These processes prevent centrosome amplification (CA), mitotic dysfunction, and chromosome instability (CIN). Our group and others have suggested that Nek2 maintains high levels of CA/CIN, tumor growth, and drug resistance. We identified that Nek2 overexpression correlates with poor survival of breast cancer. However, the mechanisms driving these phenotypes are unknown. We now report that overexpression of Nek2 in MCF10A cells drives CA/CIN and aneuploidy. Besides, enhanced levels of Nek2 results in larger 3D acinar structures, but could not initiate tumors in a p53+/+ or a p53−/− xenograft model. Nek2 overexpression induced the epithelial-to-mesenchymal transition (EMT) while its downregulation reduced the expression of the mesenchymal marker vimentin. Furthermore, either siRNA-mediated downregulation or INH6’s chemical inhibition of Nek2 in MDA-MB-231 and Hs578t cells showed important EMT changes and decreased invasion and migration. We also showed that Slug and Zeb1 are involved in Nek2 mediated EMT, invasion, and migration. Besides its role in CA/CIN, Nek2 contributes to breast cancer progression through a novel EMT mediated mechanism.

Highlights

Nek[2] (NIMA‐related kinase 2) is a serine/threonine-protein kinase that localizes to centrosomes and kinetochores, controlling centrosome separation, chromosome attachments to kinetochores, and the spindle assembly checkpoint
We demonstrated that Nek[2] induces centrosome amplification (CA) and invasive protrusions in Her2+ organoids lacking E2F356, suggesting that unregulated Nek[2] can influence early intermediates to metastasis, perhaps by inducing the epithelial-to-mesenchymal transition (EMT)
We report that the overexpression of Nek[2] in the MCF10A non-transformed mammary epithelial cell line is sufficient to initiate CA, binucleation, and micronucleation and increase the percentage of cells with extra chromosomes, all of which are landmarks of chromosome instability (CIN)

Summary

Introduction

Nek[2] (NIMA‐related kinase 2) is a serine/threonine-protein kinase that localizes to centrosomes and kinetochores, controlling centrosome separation, chromosome attachments to kinetochores, and the spindle assembly checkpoint. Since chromosome instability (CIN, or the active generation of structural and numerical chromosome changes)[1,2] accelerates tumor evolution, cells have developed mechanisms to suppress CIN, including the tight regulation of centrosome duplication and m itosis[1,3,4,5,6,7,8,9,10,11,12,13] When these processes are de-regulated[14,15,16,17,18,19,20,21], centrosome amplification (CA, or the acquisition of ≥ 3 centrosomes per cell) arises and drives mitotic perturbations, aneuploidy, defective polarity, and CIN14,22–28. None of these studies included breast cancer; here we explore the role of Nek[2] in driving breast cancer EMT

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