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MicroRNA93 regulates proliferation and differentiation of normal and malignant breast stem cells.

Liu S, Patel SH, Ginestier C, Ibarra I, Martin-Trevino R, Bai S, McDermott SP, Shang L, Ke J, Ou SJ, Heath A, Zhang KJ, Korkaya H, Clouthier SG, Charafe-Jauffret E, Birnbaum D, Hannon GJ, Wicha MS - PLoS Genet. (2012)

Bottom Line: In "claudin(low)" SUM159 cells, expression of mir-93 induces Mesenchymal-Epithelial Transition (MET) associated with downregulation of TGFβ signaling and downregulates multiple stem cell regulatory genes, including JAK1, STAT3, AKT3, SOX4, EZH1, and HMGA2, resulting in cancer stem cell (CSC) depletion.The effect of mir-93 on the CSC population is dependent on the cellular differentiation state, with mir-93 expression increasing the CSC population in MCF7 cells that display a more differentiated "luminal" phenotype. mir-93 also regulates the proliferation and differentiation of normal breast stem cells isolated from reduction mammoplasties.These studies demonstrate that miRNAs can regulate the states and fates of normal and malignant mammary stem cells, findings which have important biological and clinical implications.

View Article: PubMed Central - PubMed

Affiliation: Comprehensive Cancer Center, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA. sulingl@med.umich.edu

ABSTRACT
MicroRNAs (miRNAs) play important roles in normal cellular differentiation and oncogenesis. microRNA93 (mir-93), a member of the mir106b-25 cluster, located in intron 13 of the MCM7 gene, although frequently overexpressed in human malignancies may also function as a tumor suppressor gene. Using a series of breast cancer cell lines representing different stages of differentiation and mouse xenograft models, we demonstrate that mir-93 modulates the fate of breast cancer stem cells (BCSCs) by regulating their proliferation and differentiation states. In "claudin(low)" SUM159 cells, expression of mir-93 induces Mesenchymal-Epithelial Transition (MET) associated with downregulation of TGFβ signaling and downregulates multiple stem cell regulatory genes, including JAK1, STAT3, AKT3, SOX4, EZH1, and HMGA2, resulting in cancer stem cell (CSC) depletion. Enforced expression of mir-93 completely blocks tumor development in mammary fat pads and development of metastases following intracardiac injection in mouse xenografts. The effect of mir-93 on the CSC population is dependent on the cellular differentiation state, with mir-93 expression increasing the CSC population in MCF7 cells that display a more differentiated "luminal" phenotype. mir-93 also regulates the proliferation and differentiation of normal breast stem cells isolated from reduction mammoplasties. These studies demonstrate that miRNAs can regulate the states and fates of normal and malignant mammary stem cells, findings which have important biological and clinical implications.

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mir-93 regulates the cell cycle in SUM159 cells.A. SUM159 cells were stained with Aldefluor and Hoechst33342 and dead cells excluded by 7-AAD staining. Cells from G0/G1 and S/G2/M were sorted from ALDH+ or ALDH− populations and mir-93 expression was measured with qRT-PCR. B. Cell cycle analysis of pTRIPZ-SUM159-mir-93 cells in the presence or absence of DOX for 7 days. Propidium iodide staining followed by flow cytometry was used to analyze cell cycle distribution. mir-93 induction with DOX resulted in a decreased proportion of cells in G0/G1 and an increased proportion of cells in S/G2/M. *p<0.05; Error bars represent mean ± STDEV.
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pgen-1002751-g005: mir-93 regulates the cell cycle in SUM159 cells.A. SUM159 cells were stained with Aldefluor and Hoechst33342 and dead cells excluded by 7-AAD staining. Cells from G0/G1 and S/G2/M were sorted from ALDH+ or ALDH− populations and mir-93 expression was measured with qRT-PCR. B. Cell cycle analysis of pTRIPZ-SUM159-mir-93 cells in the presence or absence of DOX for 7 days. Propidium iodide staining followed by flow cytometry was used to analyze cell cycle distribution. mir-93 induction with DOX resulted in a decreased proportion of cells in G0/G1 and an increased proportion of cells in S/G2/M. *p<0.05; Error bars represent mean ± STDEV.

Mentions: To determine the relationship between mir-93 expression and cell cycle kinetics, we assessed mir-93 expression in quiescent and cycling ALDH+ and ALDH− populations. Cycling (S/G2/M) cells expressed significantly higher levels of mir-93 compared to quiescent (G0/G1) cells in both the ALDH− and ALDH+ compartments (Figure 5A). To determine whether mir-93 induces or is a consequence of cellular proliferation, we utilized the DOX inducible mir-93 construct to determine the effect of mir-93 induction on cell cycle distribution. Induction of mir-93 reduced the quiescent cell population from 64% to 42% suggesting that this miRNA has the capacity to directly regulate the cell cycle (Figure 5B). Furthermore, induction of mir-93 increased the proliferation of SUM159 by 29% (Figure S22). Although mir-93 induction had similar effects on the basal HCC1954 cell lines it had no significant effect on the cell cycle of the luminal MCF7 cells (Figure S22, Figure S23).


MicroRNA93 regulates proliferation and differentiation of normal and malignant breast stem cells.

Liu S, Patel SH, Ginestier C, Ibarra I, Martin-Trevino R, Bai S, McDermott SP, Shang L, Ke J, Ou SJ, Heath A, Zhang KJ, Korkaya H, Clouthier SG, Charafe-Jauffret E, Birnbaum D, Hannon GJ, Wicha MS - PLoS Genet. (2012)

mir-93 regulates the cell cycle in SUM159 cells.A. SUM159 cells were stained with Aldefluor and Hoechst33342 and dead cells excluded by 7-AAD staining. Cells from G0/G1 and S/G2/M were sorted from ALDH+ or ALDH− populations and mir-93 expression was measured with qRT-PCR. B. Cell cycle analysis of pTRIPZ-SUM159-mir-93 cells in the presence or absence of DOX for 7 days. Propidium iodide staining followed by flow cytometry was used to analyze cell cycle distribution. mir-93 induction with DOX resulted in a decreased proportion of cells in G0/G1 and an increased proportion of cells in S/G2/M. *p<0.05; Error bars represent mean ± STDEV.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3369932&req=5

pgen-1002751-g005: mir-93 regulates the cell cycle in SUM159 cells.A. SUM159 cells were stained with Aldefluor and Hoechst33342 and dead cells excluded by 7-AAD staining. Cells from G0/G1 and S/G2/M were sorted from ALDH+ or ALDH− populations and mir-93 expression was measured with qRT-PCR. B. Cell cycle analysis of pTRIPZ-SUM159-mir-93 cells in the presence or absence of DOX for 7 days. Propidium iodide staining followed by flow cytometry was used to analyze cell cycle distribution. mir-93 induction with DOX resulted in a decreased proportion of cells in G0/G1 and an increased proportion of cells in S/G2/M. *p<0.05; Error bars represent mean ± STDEV.
Mentions: To determine the relationship between mir-93 expression and cell cycle kinetics, we assessed mir-93 expression in quiescent and cycling ALDH+ and ALDH− populations. Cycling (S/G2/M) cells expressed significantly higher levels of mir-93 compared to quiescent (G0/G1) cells in both the ALDH− and ALDH+ compartments (Figure 5A). To determine whether mir-93 induces or is a consequence of cellular proliferation, we utilized the DOX inducible mir-93 construct to determine the effect of mir-93 induction on cell cycle distribution. Induction of mir-93 reduced the quiescent cell population from 64% to 42% suggesting that this miRNA has the capacity to directly regulate the cell cycle (Figure 5B). Furthermore, induction of mir-93 increased the proliferation of SUM159 by 29% (Figure S22). Although mir-93 induction had similar effects on the basal HCC1954 cell lines it had no significant effect on the cell cycle of the luminal MCF7 cells (Figure S22, Figure S23).

Bottom Line: In "claudin(low)" SUM159 cells, expression of mir-93 induces Mesenchymal-Epithelial Transition (MET) associated with downregulation of TGFβ signaling and downregulates multiple stem cell regulatory genes, including JAK1, STAT3, AKT3, SOX4, EZH1, and HMGA2, resulting in cancer stem cell (CSC) depletion.The effect of mir-93 on the CSC population is dependent on the cellular differentiation state, with mir-93 expression increasing the CSC population in MCF7 cells that display a more differentiated "luminal" phenotype. mir-93 also regulates the proliferation and differentiation of normal breast stem cells isolated from reduction mammoplasties.These studies demonstrate that miRNAs can regulate the states and fates of normal and malignant mammary stem cells, findings which have important biological and clinical implications.

View Article: PubMed Central - PubMed

Affiliation: Comprehensive Cancer Center, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA. sulingl@med.umich.edu

ABSTRACT
MicroRNAs (miRNAs) play important roles in normal cellular differentiation and oncogenesis. microRNA93 (mir-93), a member of the mir106b-25 cluster, located in intron 13 of the MCM7 gene, although frequently overexpressed in human malignancies may also function as a tumor suppressor gene. Using a series of breast cancer cell lines representing different stages of differentiation and mouse xenograft models, we demonstrate that mir-93 modulates the fate of breast cancer stem cells (BCSCs) by regulating their proliferation and differentiation states. In "claudin(low)" SUM159 cells, expression of mir-93 induces Mesenchymal-Epithelial Transition (MET) associated with downregulation of TGFβ signaling and downregulates multiple stem cell regulatory genes, including JAK1, STAT3, AKT3, SOX4, EZH1, and HMGA2, resulting in cancer stem cell (CSC) depletion. Enforced expression of mir-93 completely blocks tumor development in mammary fat pads and development of metastases following intracardiac injection in mouse xenografts. The effect of mir-93 on the CSC population is dependent on the cellular differentiation state, with mir-93 expression increasing the CSC population in MCF7 cells that display a more differentiated "luminal" phenotype. mir-93 also regulates the proliferation and differentiation of normal breast stem cells isolated from reduction mammoplasties. These studies demonstrate that miRNAs can regulate the states and fates of normal and malignant mammary stem cells, findings which have important biological and clinical implications.

Show MeSH
Related in: MedlinePlus