Adherence to osteopontin via alphavbeta3 suppresses phorbol ester-mediated apoptosis in MCF-7 breast cancer cells that overexpress protein kinase C-alpha.

  • Authors:
    • J D Noti
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  • Published online on: December 1, 2000     https://doi.org/10.3892/ijo.17.6.1237
  • Pages: 1237-1280
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Abstract

Overexpression of protein kinase C-alpha in MCF-7 breast cancer cells (MCF-7-PKC-alpha cells) results in anchorage-independent growth and increased tumorigenicity of these cells in nude mice. MCF-7-PKC-alpha cells, unlike their parental MCF-7 cells, are sensitized to apoptosis by phorbol esters. When adhered to osteopontin, a bone matrix protein, MCF-7-PKC-alpha cells were resistant to phorbol ester mediated apoptosis. Fluorescence-activated cell sorting revealed that osteopontin receptors, alphavbeta3 and alphavbeta5, are expressed on MCF-7-PKC-alpha cells and that both are used to adhere to osteopontin. Addition of an RGD-containing peptide inhibited survival of MCF-7-PKC-alpha cells exposed to phorbol ester and adhered to osteopontin. This indicated that an integrin was involved in the cell death suppression signal. Whereas, anti-alphavbeta5 antibody did not reduce survival of MCF-7-PKC-alpha cells adhered to osteopontin, anti-alphavbeta3 antibody could efficiently block suppression of apoptosis. Phorbol ester also induced increased expression of alphavbeta3 on MCF-7-PKC-alpha cells by upregulating expression of a second species of beta3 mRNA. This study suggests that breast cancer cells that have metastasized to bone may have a survival advantage resulting from interaction of alphavbeta3 on these cells with the bone protein osteopontin.

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December 2000
Volume 17 Issue 6

Print ISSN: 1019-6439
Online ISSN:1791-2423

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APA
Noti, J. (2000). Adherence to osteopontin via alphavbeta3 suppresses phorbol ester-mediated apoptosis in MCF-7 breast cancer cells that overexpress protein kinase C-alpha.. International Journal of Oncology, 17, 1237-1280. https://doi.org/10.3892/ijo.17.6.1237
MLA
Noti, J."Adherence to osteopontin via alphavbeta3 suppresses phorbol ester-mediated apoptosis in MCF-7 breast cancer cells that overexpress protein kinase C-alpha.". International Journal of Oncology 17.6 (2000): 1237-1280.
Chicago
Noti, J."Adherence to osteopontin via alphavbeta3 suppresses phorbol ester-mediated apoptosis in MCF-7 breast cancer cells that overexpress protein kinase C-alpha.". International Journal of Oncology 17, no. 6 (2000): 1237-1280. https://doi.org/10.3892/ijo.17.6.1237