TY - JOUR
T1 - Nuclear reprogramming of luminal-like breast cancer cells generates Sox2-overexpressing cancer stem-like cellular states harboring transcriptional activation of the mTOR pathway
AU - Corominas-Faja, Bruna
AU - Cufí, Sílvia
AU - Oliveras-Ferraros, Cristina
AU - Cuyàs, Elisabet
AU - López-Bonet, Eugeni
AU - Lupu, Ruth
AU - Alarcón, Tomás
AU - Vellon, Luciano
AU - Iglesias, Juan Manuel
AU - Leis, Olatz
AU - Martín, Ángel G.
AU - Vazquez-Martin, Alejandro
AU - Menendez, Javier A.
N1 - Funding Information:
This work was financially supported by the Ministerio de Ciencia e Innovación (SAF2012-38914, Plan Nacional de I+D+ I, MICINN, Spain). Alejandro Vazquez-Martin received a Sara Borrell post-doctoral contract (CD08/00283, Ministerio de Sanidad y Consumo, Fondo de Investigación Sanitaria -FIS-, Spain). Sílvia Cufí received a research fellowship (Formación de Personal Investigador, FPI) from the Ministerio de Ciencia e Innovación (MICINN, Spain).
PY - 2013/9/15
Y1 - 2013/9/15
N2 - Energy metabolism plasticity enables stemness programs during the reprogramming of somatic cells to an induced pluripotent stem cell (iPSC) state. This relationship may introduce a new era in the understanding of Warburg's theory on the metabolic origin of cancer at the level of cancer stem cells (CSCs). Here, we used Yamanaka's stem cell technology in an attempt to create stable CSC research lines in which to dissect the transcriptional control of mTO R - the master switch of cellular catabolism and anabolism - in CSC-like states. The rare colonies with iPSC-like morphology, obtained following the viral transduction of the Oct4, Sox2, Klf4, and c-Myc (OSKM) stemness factors into MCF-7 luminal-like breast cancer cells (MCF-7/Rep), demonstrated an intermediate state between cancer cells and bona fide iPSCs. MCF-7/Rep cells notably overexpressed SOX2 and stage-specific embryonic antigen (SSEA)-4 proteins; however, other stemness-related markers (OCT4, NANOG, SSEA-1, TRA-1-60, and TRA-1-81) were found at low to moderate levels. The transcriptional analyses of OSKM factors confirmed the strong but unique reactivation of the endogenous Sox2 stemness gene accompanied by the silencing of the exogenous Sox2 transgene in MCF-7/Rep cells. Some but not all MCF-7/Rep cells acquired strong alkaline phosphatase (AP) activity compared with MCF-7 parental cells. SOX2-overexpressing MCF-7/Rep cells contained drastically higher percentages of CD44+ and ALDEFLUOR-stained ALDHbright cells than MCF-7 parental cells. The overlap between differentially expressed mTO R signaling-related genes in 3 different SOX2-overexpressing CSC-like cell lines revealed a notable downregulation of 3 genes, PRKAA1 (which codes for the catalytic α 1 subunit of AMPK), DDIT4/REDD1 (a stress response gene that operates as a negative regulator of mTO R), and DEPTOR (a naturally occurring endogenous inhibitor of mTO R activity). The insulin-receptor gene (INSR) was differentially upregulated in MCF-7/Rep cells. Consistent with the downregulation of AMPK expression, immunoblotting procedures confirmed upregulation of p70S6K and increased phosphorylation of mTO R in Sox2-overexpressing CSC-like cell populations. Using an in vitro model of the de novo generation of CSC-like states through the nuclear reprogramming of an established breast cancer cell line, we reveal that the transcriptional suppression of mTO R repressors is an intrinsic process occurring during the acquisition of CSC-like properties by differentiated populations of luminal-like breast cancer cells. This approach may provide a new path for obtaining information about preventing the appearance of CSCs through the modulation of the AMPK/mTO R pathway.
AB - Energy metabolism plasticity enables stemness programs during the reprogramming of somatic cells to an induced pluripotent stem cell (iPSC) state. This relationship may introduce a new era in the understanding of Warburg's theory on the metabolic origin of cancer at the level of cancer stem cells (CSCs). Here, we used Yamanaka's stem cell technology in an attempt to create stable CSC research lines in which to dissect the transcriptional control of mTO R - the master switch of cellular catabolism and anabolism - in CSC-like states. The rare colonies with iPSC-like morphology, obtained following the viral transduction of the Oct4, Sox2, Klf4, and c-Myc (OSKM) stemness factors into MCF-7 luminal-like breast cancer cells (MCF-7/Rep), demonstrated an intermediate state between cancer cells and bona fide iPSCs. MCF-7/Rep cells notably overexpressed SOX2 and stage-specific embryonic antigen (SSEA)-4 proteins; however, other stemness-related markers (OCT4, NANOG, SSEA-1, TRA-1-60, and TRA-1-81) were found at low to moderate levels. The transcriptional analyses of OSKM factors confirmed the strong but unique reactivation of the endogenous Sox2 stemness gene accompanied by the silencing of the exogenous Sox2 transgene in MCF-7/Rep cells. Some but not all MCF-7/Rep cells acquired strong alkaline phosphatase (AP) activity compared with MCF-7 parental cells. SOX2-overexpressing MCF-7/Rep cells contained drastically higher percentages of CD44+ and ALDEFLUOR-stained ALDHbright cells than MCF-7 parental cells. The overlap between differentially expressed mTO R signaling-related genes in 3 different SOX2-overexpressing CSC-like cell lines revealed a notable downregulation of 3 genes, PRKAA1 (which codes for the catalytic α 1 subunit of AMPK), DDIT4/REDD1 (a stress response gene that operates as a negative regulator of mTO R), and DEPTOR (a naturally occurring endogenous inhibitor of mTO R activity). The insulin-receptor gene (INSR) was differentially upregulated in MCF-7/Rep cells. Consistent with the downregulation of AMPK expression, immunoblotting procedures confirmed upregulation of p70S6K and increased phosphorylation of mTO R in Sox2-overexpressing CSC-like cell populations. Using an in vitro model of the de novo generation of CSC-like states through the nuclear reprogramming of an established breast cancer cell line, we reveal that the transcriptional suppression of mTO R repressors is an intrinsic process occurring during the acquisition of CSC-like properties by differentiated populations of luminal-like breast cancer cells. This approach may provide a new path for obtaining information about preventing the appearance of CSCs through the modulation of the AMPK/mTO R pathway.
KW - AMPK
KW - Breast cancer
KW - Cancer stem cells
KW - MTOR
KW - Reprogramming
KW - SOX2
UR - http://www.scopus.com/inward/record.url?scp=84884849331&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84884849331&partnerID=8YFLogxK
U2 - 10.4161/cc.26173
DO - 10.4161/cc.26173
M3 - Article
C2 - 23974095
AN - SCOPUS:84884849331
SN - 1538-4101
VL - 12
SP - 3109
EP - 3124
JO - Cell Cycle
JF - Cell Cycle
IS - 18
ER -