Secreted frizzled-related protein 4 inhibits glioma stem-like cells by reversing epithelial to mesenchymal transition, inducing apoptosis and decreasing cancer stem cell properties

G Bhuvanalakshmi; Frank Arfuso; Michael Millward; Arun Dharmarajan; Sudha Warrier

doi:10.1371/journal.pone.0127517

Secreted frizzled-related protein 4 inhibits glioma stem-like cells by reversing epithelial to mesenchymal transition, inducing apoptosis and decreasing cancer stem cell properties

PLoS One. 2015 Jun 1;10(6):e0127517. doi: 10.1371/journal.pone.0127517. eCollection 2015.

Authors

G Bhuvanalakshmi¹, Frank Arfuso², Michael Millward³, Arun Dharmarajan⁴, Sudha Warrier⁵

Affiliations

¹ Division of Cancer Stem Cells and Cardiovascular Regeneration, Manipal Institute of Regenerative Medicine, Manipal University, Bangalore, 560 065, India.
² Stem Cell and Cancer Biology Laboratory, School of Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University, Perth, 6845, Western Australia; School of Anatomy, Physiology and Human Biology, Faculty of Science, The University of Western Australia, 35 Stirling Highway, Crawley, 6009, Western Australia.
³ School of Medicine and Pharmacology, The University of Western Australia, Crawley, 6009, Western Australia.
⁴ Stem Cell and Cancer Biology Laboratory, School of Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University, Perth, 6845, Western Australia.
⁵ Division of Cancer Stem Cells and Cardiovascular Regeneration, Manipal Institute of Regenerative Medicine, Manipal University, Bangalore, 560 065, India; Stem Cell and Cancer Biology Laboratory, School of Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University, Perth, 6845, Western Australia.

Abstract

The Wnt pathway is integrally involved in regulating self-renewal, proliferation, and maintenance of cancer stem cells (CSCs). We explored the effect of the Wnt antagonist, secreted frizzled-related protein 4 (sFRP4), in modulating epithelial to mesenchymal transition (EMT) in CSCs from human glioblastoma cells lines, U87 and U373. sFRP4 chemo-sensitized CSC-enriched cells to the most commonly used anti-glioblastoma drug, temozolomide (TMZ), by the reversal of EMT. Cell movement, colony formation, and invasion in vitro were suppressed by sFRP4+TMZ treatment, which correlated with the switch of expression of markers from mesenchymal (Twist, Snail, N-cadherin) to epithelial (E-cadherin). sFRP4 treatment elicited activation of the Wnt-Ca2(+) pathway, which antagonizes the Wnt/ß-catenin pathway. Significantly, the chemo-sensitization effect of sFRP4 was correlated with the reduction in the expression of drug resistance markers ABCG2, ABCC2, and ABCC4. The efficacy of sFRP4+TMZ treatment was demonstrated in vivo using nude mice, which showed minimum tumor engraftment using CSCs pretreated with sFRP4+TMZ. These studies indicate that sFRP4 treatment would help to improve response to commonly used chemotherapeutics in gliomas by modulating EMT via the Wnt/ß-catenin pathway. These findings could be exploited for designing better targeted strategies to improve chemo-response and eventually eliminate glioblastoma CSCs.

Publication types

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

MeSH terms

ATP Binding Cassette Transporter, Subfamily G, Member 2
ATP-Binding Cassette Transporters / metabolism
Animals
Apoptosis / drug effects
Cadherins / metabolism
Cell Line, Tumor
Dacarbazine / analogs & derivatives
Dacarbazine / pharmacology
Epithelial-Mesenchymal Transition / drug effects
Epithelial-Mesenchymal Transition / genetics
Glioma / genetics
Glioma / metabolism*
Humans
Male
Mice
Mice, Nude
Multidrug Resistance-Associated Protein 2
Multidrug Resistance-Associated Proteins / metabolism
Neoplasm Proteins / metabolism
Neoplastic Stem Cells / cytology
Neoplastic Stem Cells / drug effects
Neoplastic Stem Cells / metabolism
Proto-Oncogene Proteins / genetics
Proto-Oncogene Proteins / metabolism*
Snails / metabolism
Temozolomide
Twist-Related Protein 1 / metabolism

Substances

ABCC2 protein, human
ABCC4 protein, human
ABCG2 protein, human
ATP Binding Cassette Transporter, Subfamily G, Member 2
ATP-Binding Cassette Transporters
Cadherins
Multidrug Resistance-Associated Protein 2
Multidrug Resistance-Associated Proteins
Neoplasm Proteins
Proto-Oncogene Proteins
SFRP4 protein, human
Twist-Related Protein 1
Dacarbazine
Temozolomide

Grants and funding

This work was supported by Curtin University Commercialization Advisory Board and School of Biomedical Sciences Strategic Research Funds, India Research Initiative funds (Prof Arun Dharmarajan), funding from the Department of Biotechnology, India (BT/PR8493/MED/31/226/2013) and funds provided by Prof Michael Millward, University of Western Australia, Perth, Western Australia.