Na + /K +  ATPase activity promotes invasion of endocrine resistant breast cancer cells

There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

Abstract

Background

The Na ⁺/K ⁺-ATPase (NKP) is an important ion transporter also involved in signal transduction. Its expression profile is altered in various tumours including that of the breast. We studied the effect of inhibiting NKP activity in non-tumorigenic breast cell line and in estrogen receptor positive and negative breast cancer cells.

Methods

Expression and localization of NKP and downstream signaling molecules were determined by RT-PCR, western blotting and immunofluorescence. Cell proliferation, apoptosis and cell cycle stage were determined using MTT, annexin V and flow cytometry. Cell motility and invasion were determined using wound healing and matrigel assays. Total matrix metalloproteinase (MMP) was determined by a fluorescence-based assay.

Results

NKP was mainly localized on the cell membrane. Its baseline expression and activity were enhanced in breast cancer compared to the non-tumorigenic breast cell line. Ouabain and 3,4,5,6-tetrahydroxyxanthone (TTX) treatment significantly inhibited NKP activity, which significantly reduced cell proliferation, motility, invasion and pH-induced membrane blebbing. EGF stimulation induced internalization of NKP from the cell membrane to the cytoplasm. Ouabain inhibited EGF-induced phosphorylation of Rac/cdc42, profillin, ERK1/2 and P70S6K.

Conclusions

The NKP may offer a novel therapeutic target in breast cancer patients who have developed metastasis, aiming to improve therapeutic outcomes and enhance survival rate.

Related collections

Most cited references 50

Record: found
Abstract: found
Article: not found

Loss of epithelial differentiation and gain of invasiveness correlates with tyrosine phosphorylation of the E-cadherin/beta-catenin complex in cells transformed with a temperature-sensitive v-SRC gene

L Vakaet, R Friis, W Birchmeier … (1993)

Loss of histotypic organization of epithelial cells is a common feature in normal development as well as in the invasion of carcinomas. Here we show that the v-src oncogene is a potent effector of epithelial differentiation and invasiveness. MDCK epithelial cells transformed with a temperature-sensitive mutant of v-src exhibit a strictly epithelial phenotype at the nonpermissive temperature for pp60v-src activity (40.5 degrees C) but rapidly loose cell-to-cell contacts and acquire a fibroblast-like morphology after culture at the permissive temperature (35 degrees C). Furthermore, the invasiveness of the cells into collagen gels or into chick heart fragments was increased at the permissive temperature. The profound effects of v-src on intercellular adhesion were not linked to changes in the levels of expression of the epithelial cell adhesion molecule E-cadherin. Rather, we observed an increase in tyrosine phosphorylation of E-cadherin and, in particular, of the associated protein beta-catenin. These results suggest a mechanism by which v-src counteracts junctional assembly and thereby promotes invasiveness and dedifferentiation of epithelial cells through phosphorylation of the E-cadherin/catenin complex.

0 comments Cited 107 times – based on 0 reviews      Review now

Bookmark

Record: found
Abstract: found
Article: not found

Binding of Src to Na+/K+-ATPase forms a functional signaling complex.

Jiang Tian, Lijun Liu, Michael Haas … (2005)

We have shown that ouabain activates Src, resulting in subsequent tyrosine phosphorylation of multiple effectors. Here, we tested if the Na+/K+-ATPase and Src can form a functional signaling complex. In LLC-PK1 cells the Na+/K+-ATPase and Src colocalized in the plasma membrane. Fluorescence resonance energy transfer analysis indicated that both proteins were in close proximity, suggesting a direct interaction. GST pulldown assay showed a direct, ouabain-regulated, and multifocal interaction between the 1 subunit of Na+/K+-ATPase and Src. Although the interaction between the Src kinase domain and the third cytosolic domain (CD3) of 1 is regulated by ouabain, the Src SH3SH2 domain binds to the second cytosolic domain constitutively. Functionally, binding of Src to either the Na+/K+-ATPase or GST-CD3 inhibited Src activity. Addition of ouabain, but not vanadate, to the purified Na+/K+-ATPase/Src complex freed the kinase domain and restored the Src activity. Consistently, exposure of intact cells to ouabain apparently increased the distance between the Na+/K+-ATPase and Src. Concomitantly, it also stimulated tyrosine phosphorylation of the proteins that are associated with the Na+/K+-ATPase. These new findings illustrate a novel molecular mechanism of signal transduction involving the interaction of a P-type ATPase and a nonreceptor tyrosine kinase.

0 comments Cited 104 times – based on 0 reviews      Review now

Bookmark

Record: found
Abstract: found
Article: not found

Na(+)/K(+)-ATPase as a signal transducer.

Amir Askari, Zijian Xie (2002)

Na(+)/K(+)-ATPase as an energy transducing ion pump has been studied extensively since its discovery in 1957. Although early findings suggested a role for Na(+)/K(+)-ATPase in regulation of cell growth and expression of various genes, only in recent years the mechanisms through which this plasma membrane enzyme communicates with the nucleus have been studied. This research, carried out mostly on cardiac myocytes, shows that in addition to pumping ions, Na(+)/K+-ATPase interacts with neighboring membrane proteins and organized cytosolic cascades of signaling proteins to send messages to the intracellular organelles. The signaling pathways that are rapidly elicited by the interaction of ouabain with Na(+)/K(+)-ATPase, and are independent of changes in intracellular Na(+) and K(+) concentrations, include activation of Src kinase, transactivation of the epidermal growth factor receptor by Src, activation of Ras and p42/44 mitogen-activated protein kinases, and increased generation of reactive oxygen species by mitochondria. In cardiac myocytes, the resulting downstream events include the induction of some early response proto-oncogenes, activation of the transcription factors, activator protein-1 and nuclear factor kappa-B, regulation of a number of cardiac growth-related genes, and stimulation of protein synthesis and myocyte hypertrophy. For these downstream events, the induced reactive oxygen species and rise in intracellular Ca(2+) are essential second messengers. In cells other than cardiac myocytes, the proximal pathways linked to Na(+)/K(+)-ATPase through protein-protein interactions are similar to those reported in myocytes, but the downstream events and consequences may be significantly different. The likely extracellular physiological stimuli for the signal transducing function of Na+/K+-ATPase are the endogenous ouabain-like hormones, and changes in extracellular K+ concentration.

0 comments Cited 86 times – based on 0 reviews      Review now

Bookmark

All references

Author and article information

Contributors

Maitham A. Khajah:

ORCID: http://orcid.org/0000-0002-6415-7985

Role: ConceptualizationRole: Data curationRole: Formal analysisRole: Funding acquisitionRole: InvestigationRole: MethodologyRole: Project administrationRole: ResourcesRole: SupervisionRole: ValidationRole: Writing – original draftRole: Writing – review & editing

Princy M. Mathew: Role: Data curationRole: MethodologyRole: Project administration

Yunus A. Luqmani: Role: ConceptualizationRole: Project administrationRole: ResourcesRole: SupervisionRole: Writing – original draftRole: Writing – review & editing

Arun Rishi: Role: Editor

Journal

Journal ID (nlm-ta): PLoS One

Journal ID (iso-abbrev): PLoS ONE

Journal ID (publisher-id): plos

Journal ID (pmc): plosone

Title: PLoS ONE

Publisher: Public Library of Science (San Francisco, CA USA )

ISSN (Electronic): 1932-6203

Publication date (Electronic): 28 March 2018

Publication date Collection: 2018

Volume: 13

Issue: 3

Electronic Location Identifier: e0193779

Affiliations

[001]Faculty of Pharmacy, Kuwait University, Safat, Kuwait

Wayne State University, UNITED STATES

Author notes

Competing Interests: The authors have declared that no competing interests exist.

* E-mail: maitham@ 123456hsc.edu.kw

Author information

Maitham A. Khajah http://orcid.org/0000-0002-6415-7985

Article

Publisher ID: PONE-D-17-42635

DOI: 10.1371/journal.pone.0193779

PMC ID: 5874017

PubMed ID: 29590154

SO-VID: 099c3773-a54a-41a8-9024-657902485ffe

License:

This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

History

Date received : 11 December 2017

Date accepted : 17 February 2018

Page count

Figures: 14, Tables: 0, Pages: 27

Funding

Funded by: funder-id http://dx.doi.org/10.13039/501100004482, Kuwait University;

Award ID: PT01/14

Award Recipient :

ORCID: http://orcid.org/0000-0002-6415-7985

Maitham A. Khajah

This work was supported by Kuwait University Research Sector grant PT01/14 (MAK). Parts of this work were supported by grant SRUL02/13 to the Research Unit for Genomics, Proteomics and Cellomics Studies (OMICS), Kuwait University.

Custom metadata

Data Availability All relevant data are within the paper.

ScienceOpen disciplines: Uncategorized

Data availability:

ScienceOpen disciplines: Uncategorized

Comments

Comment on this article

scite_

Cited by 20

See all cited by

Most referenced authors 1,118

See all reference authors