Limits...
MUC1* mediates the growth of human pluripotent stem cells.

Hikita ST, Kosik KS, Clegg DO, Bamdad C - PLoS ONE (2008)

Bottom Line: Unexpectedly, we found that newly differentiated cells no longer express the cleaved form, MUC1*, or its ligand, NM23.Antibody-induced dimerization of the MUC1* receptor on hESCs stimulated cell growth to a far greater degree than currently used methods that require the addition of exogenous basic fibroblast growth factor (bFGF) as well as factors secreted by fibroblast "feeder cells".These findings suggest that this primal growth mechanism could be utilized to propagate large numbers of pluripotent stem cells for therapeutic interventions.

View Article: PubMed Central - PubMed

Affiliation: Center for Stem Cell Biology and Engineering, University of California Santa Barbara, Santa Barbara, California, USA.

ABSTRACT
The MUC1 protein is aberrantly expressed on an estimated 75% of all human solid tumor cancers. We recently reported that a transmembrane cleavage product, MUC1*, is the predominant form of the protein on cancer cells [1]. Further, our evidence indicated that MUC1* functions as a growth factor receptor on tumor cells, while the full-length protein appeared to have no growth promoting activity. Here, we report that MUC1* acts as a growth factor receptor on undifferentiated human embryonic stem cells (hESCs). Cleavage of the full-length ectodomain to form MUC1*, a membrane receptor, appears to make binding to its ligand, NM23, possible. Unexpectedly, we found that newly differentiated cells no longer express the cleaved form, MUC1*, or its ligand, NM23. Newly differentiated stem cells exclusively present full-length MUC1. Antibody-induced dimerization of the MUC1* receptor on hESCs stimulated cell growth to a far greater degree than currently used methods that require the addition of exogenous basic fibroblast growth factor (bFGF) as well as factors secreted by fibroblast "feeder cells". Further, MUC1* mediated growth was shown to be independent of growth stimulated by bFGF or the milieu of factors secreted by feeder cells. Stimulating the MUC1* receptor with either the cognate antibody or its ligand NM23 enabled hESC growth in a feeder cell-free system and produced pluripotent colonies that resisted spontaneous differentiation. These findings suggest that this primal growth mechanism could be utilized to propagate large numbers of pluripotent stem cells for therapeutic interventions.

Show MeSH

Related in: MedlinePlus

MUC1* co-localizes with OCT4 and other markers of pluripotency on undifferentiated human embryonic stem cells (hESCs).Undifferentiated H9 hESCs were cultured according to standard methods on chamber slides then double stained with Anti-MUC1* and antibodies that recognize known markers of pluripotency: A. MUC1* is co-expressed with OCT4 on undifferentiated hESCs. B. MUC1* and SSEA4 co-localize to a great extent on undifferentiated hESC colonies. C. MUC1* and Tra 1–81 partially co-localize on undifferentiated hESC colonies. D. MUC1* and Tra 1–60 are co-expressed on hESCs. Dotted lines indicate the border of the undifferentiated colony. Scale bars = 100 µm.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2553196&req=5

pone-0003312-g002: MUC1* co-localizes with OCT4 and other markers of pluripotency on undifferentiated human embryonic stem cells (hESCs).Undifferentiated H9 hESCs were cultured according to standard methods on chamber slides then double stained with Anti-MUC1* and antibodies that recognize known markers of pluripotency: A. MUC1* is co-expressed with OCT4 on undifferentiated hESCs. B. MUC1* and SSEA4 co-localize to a great extent on undifferentiated hESC colonies. C. MUC1* and Tra 1–81 partially co-localize on undifferentiated hESC colonies. D. MUC1* and Tra 1–60 are co-expressed on hESCs. Dotted lines indicate the border of the undifferentiated colony. Scale bars = 100 µm.

Mentions: Immunocytochemistry experiments showed that MUC1* is highly expressed on undifferentiated hESCs; double staining experiments with an antibody against OCT4 confirmed that the cells that expressed MUC1* were in fact undifferentiated stem cells (Fig. 2A). DAPI staining revealed that both MUC1* and OCT4 were expressed by essentially all the undifferentiated cells (data not shown). Figure 2B shows that MUC1* expression also co-localized with SSEA4, another marker for undifferentiated hESCs [29], although expression between these two did not always precisely co-localize. MUC1* co-localized to a similar extent on undifferentiated hESCs with Tra 1–81 and Tra 1–60 [30] which are also indicators of the undifferentiated state (Figs. 2 C,D). MUC1* appears to be surface-expressed as evidenced by antibody staining in the absence of added detergent (Figs. 2 B–D). Control experiments for all immunocytochemistry imaging are shown in Figure S6.


MUC1* mediates the growth of human pluripotent stem cells.

Hikita ST, Kosik KS, Clegg DO, Bamdad C - PLoS ONE (2008)

MUC1* co-localizes with OCT4 and other markers of pluripotency on undifferentiated human embryonic stem cells (hESCs).Undifferentiated H9 hESCs were cultured according to standard methods on chamber slides then double stained with Anti-MUC1* and antibodies that recognize known markers of pluripotency: A. MUC1* is co-expressed with OCT4 on undifferentiated hESCs. B. MUC1* and SSEA4 co-localize to a great extent on undifferentiated hESC colonies. C. MUC1* and Tra 1–81 partially co-localize on undifferentiated hESC colonies. D. MUC1* and Tra 1–60 are co-expressed on hESCs. Dotted lines indicate the border of the undifferentiated colony. Scale bars = 100 µm.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2553196&req=5

pone-0003312-g002: MUC1* co-localizes with OCT4 and other markers of pluripotency on undifferentiated human embryonic stem cells (hESCs).Undifferentiated H9 hESCs were cultured according to standard methods on chamber slides then double stained with Anti-MUC1* and antibodies that recognize known markers of pluripotency: A. MUC1* is co-expressed with OCT4 on undifferentiated hESCs. B. MUC1* and SSEA4 co-localize to a great extent on undifferentiated hESC colonies. C. MUC1* and Tra 1–81 partially co-localize on undifferentiated hESC colonies. D. MUC1* and Tra 1–60 are co-expressed on hESCs. Dotted lines indicate the border of the undifferentiated colony. Scale bars = 100 µm.
Mentions: Immunocytochemistry experiments showed that MUC1* is highly expressed on undifferentiated hESCs; double staining experiments with an antibody against OCT4 confirmed that the cells that expressed MUC1* were in fact undifferentiated stem cells (Fig. 2A). DAPI staining revealed that both MUC1* and OCT4 were expressed by essentially all the undifferentiated cells (data not shown). Figure 2B shows that MUC1* expression also co-localized with SSEA4, another marker for undifferentiated hESCs [29], although expression between these two did not always precisely co-localize. MUC1* co-localized to a similar extent on undifferentiated hESCs with Tra 1–81 and Tra 1–60 [30] which are also indicators of the undifferentiated state (Figs. 2 C,D). MUC1* appears to be surface-expressed as evidenced by antibody staining in the absence of added detergent (Figs. 2 B–D). Control experiments for all immunocytochemistry imaging are shown in Figure S6.

Bottom Line: Unexpectedly, we found that newly differentiated cells no longer express the cleaved form, MUC1*, or its ligand, NM23.Antibody-induced dimerization of the MUC1* receptor on hESCs stimulated cell growth to a far greater degree than currently used methods that require the addition of exogenous basic fibroblast growth factor (bFGF) as well as factors secreted by fibroblast "feeder cells".These findings suggest that this primal growth mechanism could be utilized to propagate large numbers of pluripotent stem cells for therapeutic interventions.

View Article: PubMed Central - PubMed

Affiliation: Center for Stem Cell Biology and Engineering, University of California Santa Barbara, Santa Barbara, California, USA.

ABSTRACT
The MUC1 protein is aberrantly expressed on an estimated 75% of all human solid tumor cancers. We recently reported that a transmembrane cleavage product, MUC1*, is the predominant form of the protein on cancer cells [1]. Further, our evidence indicated that MUC1* functions as a growth factor receptor on tumor cells, while the full-length protein appeared to have no growth promoting activity. Here, we report that MUC1* acts as a growth factor receptor on undifferentiated human embryonic stem cells (hESCs). Cleavage of the full-length ectodomain to form MUC1*, a membrane receptor, appears to make binding to its ligand, NM23, possible. Unexpectedly, we found that newly differentiated cells no longer express the cleaved form, MUC1*, or its ligand, NM23. Newly differentiated stem cells exclusively present full-length MUC1. Antibody-induced dimerization of the MUC1* receptor on hESCs stimulated cell growth to a far greater degree than currently used methods that require the addition of exogenous basic fibroblast growth factor (bFGF) as well as factors secreted by fibroblast "feeder cells". Further, MUC1* mediated growth was shown to be independent of growth stimulated by bFGF or the milieu of factors secreted by feeder cells. Stimulating the MUC1* receptor with either the cognate antibody or its ligand NM23 enabled hESC growth in a feeder cell-free system and produced pluripotent colonies that resisted spontaneous differentiation. These findings suggest that this primal growth mechanism could be utilized to propagate large numbers of pluripotent stem cells for therapeutic interventions.

Show MeSH
Related in: MedlinePlus