HAMLET Binding to α-Actinin Facilitates Tumor Cell Detachment.
Trulsson, Maria LU ; Yu, Hao LU ; Gisselsson, Lennart ; Chao, Yinxia ; Urbano, Alexander ; Aits, Sonja LU
; Mossberg, Anki
LU
and Svanborg, Catharina
LU
(2011)
In PLoS ONE
6(3).
- Abstract
- Cell adhesion is tightly regulated by specific molecular interactions and detachment from the extracellular matrix modifies proliferation and survival. HAMLET (Human Alpha-lactalbumin Made LEthal to Tumor cells) is a protein-lipid complex with tumoricidal activity that also triggers tumor cell detachment in vitro and in vivo, suggesting that molecular interactions defining detachment are perturbed in cancer cells. To identify such interactions, cell membrane extracts were used in Far-western blots and HAMLET was shown to bind α-actinins; major F-actin cross-linking proteins and focal adhesion constituents. Synthetic peptide mapping revealed that HAMLET binds to the N-terminal actin-binding domain as well as the integrin-binding domain of... (More)
- Cell adhesion is tightly regulated by specific molecular interactions and detachment from the extracellular matrix modifies proliferation and survival. HAMLET (Human Alpha-lactalbumin Made LEthal to Tumor cells) is a protein-lipid complex with tumoricidal activity that also triggers tumor cell detachment in vitro and in vivo, suggesting that molecular interactions defining detachment are perturbed in cancer cells. To identify such interactions, cell membrane extracts were used in Far-western blots and HAMLET was shown to bind α-actinins; major F-actin cross-linking proteins and focal adhesion constituents. Synthetic peptide mapping revealed that HAMLET binds to the N-terminal actin-binding domain as well as the integrin-binding domain of α-actinin-4. By co-immunoprecipitation of extracts from HAMLET-treated cancer cells, an interaction with α-actinin-1 and -4 was observed. Inhibition of α-actinin-1 and α-actinin-4 expression by siRNA transfection increased detachment, while α-actinin-4-GFP over-expression significantly delayed rounding up and detachment of tumor cells in response to HAMLET. In response to HAMLET, adherent tumor cells rounded up and detached, suggesting a loss of the actin cytoskeletal organization. These changes were accompanied by a reduction in β1 integrin staining and a decrease in FAK and ERK1/2 phosphorylation, consistent with a disruption of integrin-dependent cell adhesion signaling. Detachment per se did not increase cell death during the 22 hour experimental period, regardless of α-actinin-4 and α-actinin-1 expression levels but adherent cells with low α-actinin levels showed increased death in response to HAMLET. The results suggest that the interaction between HAMLET and α-actinins promotes tumor cell detachment. As α-actinins also associate with signaling molecules, cytoplasmic domains of transmembrane receptors and ion channels, additional α-actinin-dependent mechanisms are discussed. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/1883909
- author
- Trulsson, Maria
LU
; Yu, Hao
LU
; Gisselsson, Lennart
; Chao, Yinxia
; Urbano, Alexander
; Aits, Sonja
LU
; Mossberg, Anki
LU
and Svanborg, Catharina
LU
- organization
- publishing date
- 2011
- type
- Contribution to journal
- publication status
- published
- subject
- in
- PLoS ONE
- volume
- 6
- issue
- 3
- article number
- e17179
- publisher
- Public Library of Science (PLoS)
- external identifiers
-
- wos:000288170000014
- pmid:21408150
- scopus:79952479246
- pmid:21408150
- ISSN
- 1932-6203
- DOI
- 10.1371/journal.pone.0017179
- language
- English
- LU publication?
- yes
- id
- c740c8b2-d0bd-4b18-9d65-70441e487fc8 (old id 1883909)
- alternative location
- http://www.ncbi.nlm.nih.gov/pubmed/21408150?dopt=Abstract
- date added to LUP
- 2016-04-01 14:35:44
- date last changed
- 2022-03-06 20:08:07
@article{c740c8b2-d0bd-4b18-9d65-70441e487fc8,
abstract = {{Cell adhesion is tightly regulated by specific molecular interactions and detachment from the extracellular matrix modifies proliferation and survival. HAMLET (Human Alpha-lactalbumin Made LEthal to Tumor cells) is a protein-lipid complex with tumoricidal activity that also triggers tumor cell detachment in vitro and in vivo, suggesting that molecular interactions defining detachment are perturbed in cancer cells. To identify such interactions, cell membrane extracts were used in Far-western blots and HAMLET was shown to bind α-actinins; major F-actin cross-linking proteins and focal adhesion constituents. Synthetic peptide mapping revealed that HAMLET binds to the N-terminal actin-binding domain as well as the integrin-binding domain of α-actinin-4. By co-immunoprecipitation of extracts from HAMLET-treated cancer cells, an interaction with α-actinin-1 and -4 was observed. Inhibition of α-actinin-1 and α-actinin-4 expression by siRNA transfection increased detachment, while α-actinin-4-GFP over-expression significantly delayed rounding up and detachment of tumor cells in response to HAMLET. In response to HAMLET, adherent tumor cells rounded up and detached, suggesting a loss of the actin cytoskeletal organization. These changes were accompanied by a reduction in β1 integrin staining and a decrease in FAK and ERK1/2 phosphorylation, consistent with a disruption of integrin-dependent cell adhesion signaling. Detachment per se did not increase cell death during the 22 hour experimental period, regardless of α-actinin-4 and α-actinin-1 expression levels but adherent cells with low α-actinin levels showed increased death in response to HAMLET. The results suggest that the interaction between HAMLET and α-actinins promotes tumor cell detachment. As α-actinins also associate with signaling molecules, cytoplasmic domains of transmembrane receptors and ion channels, additional α-actinin-dependent mechanisms are discussed.}},
author = {{Trulsson, Maria and Yu, Hao and Gisselsson, Lennart and Chao, Yinxia and Urbano, Alexander and Aits, Sonja and Mossberg, Anki and Svanborg, Catharina}},
issn = {{1932-6203}},
language = {{eng}},
number = {{3}},
publisher = {{Public Library of Science (PLoS)}},
series = {{PLoS ONE}},
title = {{HAMLET Binding to α-Actinin Facilitates Tumor Cell Detachment.}},
url = {{https://lup.lub.lu.se/search/files/4060295/1890285.pdf}},
doi = {{10.1371/journal.pone.0017179}},
volume = {{6}},
year = {{2011}},
}