The increase in cytosolic levels of protein kinase C precedes the growth factor requirements during the transition stem cells to differentiated progeny in the MCF-7 breast tumor cells.

Authors

  • Maria L. Gomez,

    1. Instituto de Ingeniera Genetica y Biologia Molecular (INGEBI, CONICET)
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    • Department of Cellular and Structural Biology, The University of Texas Health Science Center at San Antonio

  • Mariana Resnicoff,

    1. Instituto de Investigaciones Bioquimicas Luis F. Leloir, Facultad de Ciencias Exactas y Naturales (UBA), Buenos Aires. Argentina
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    • Thomas Jefferson University, Bluemle Life Sciences Building Philadelphia, PA 19107

  • Estela E. Medrano,

    1. Instituto de Investigaciones Bioquimicas Luis F. Leloir, Facultad de Ciencias Exactas y Naturales (UBA), Buenos Aires. Argentina
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    • Department of Dermatology, University of Cincinnati College of Medicine, 231 Bethesda Avenue, Cincinnati Ohio, 45267-0592 USA.

  • Maria T. Tellez-Inon

    1. Instituto de Ingeniera Genetica y Biologia Molecular (INGEBI, CONICET)
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    • Department of Cellular and Structural Biology, The University of Texas Health Science Center at San Antonio


Abstract

The expression of regulatory genes within the context of a differentiation program can have profound long-term consequences in tissues with permanent renewing populations. The breast tumor cell line MCF-7 retains in culture some of the characteristics of a unidirectional differentiation pathway. We show that the cytosolic activity of the regulatory enzyme protein kinase C (PKC) precedes and continues the sequence of maturation in pre-differentiated subpopulations derived from a stem cell fraction. However, the activity declines in the most differentiated, post-mitotic fraction. These results indicate that PKC may be considered among the regulatory genes in MCF-7 cells that specify maturation of the stem cell progeny.

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