Levels of p21(WAF1/CIP1) do not affect radiation-induced cell death in human breast epithelial cells

  • Authors:
    • H Kim
    • G Li
    • S Han
    • K Rahman
    • H Liu
    • D Waid
    • Y Lee
  • View Affiliations

  • Published online on: December 1, 1997     https://doi.org/10.3892/ijo.11.6.1349
  • Pages: 1349-1353
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Abstract

Loss of the wild-type p53 activity and/or overexpression of the proto-oncogene bcl-2 are frequently detected in breast cancer and suggested to be related to chemotherapy and radiation therapy resistance. To identify the downstream signaling molecules for anti-proliferative and apoptotic activities of p53 and to investigate the interaction of bcl-2 with p53 in human breast epithelial cells, we have used the MCF10A cell line. We previously showed that overexpression of bcl-2 downregulates expression of p21(WAF1/CIP1) (a cyclin dependent kinase inhibitor which mediates p53 dependent G(1) arrest) and suppresses DNA damage-induced apoptosis in MCF10A cells. In the present study, we constitutively overexpressed p21(WAF1/CIP1) in bcl-2 overexpressing MCF10A cells to determine whether downregulation of p21(WAF1/CIP1) is necessary for the anti apoptotic activity of bcl-2, and to investigate the roles of p21(WAF1/CIP1) in p53-mediated cell death upon irradiation. Overexpression of p21(WAF1/CIP1) resulted in growth inhibition, but had no effect on bcl-2 inhibition of apoptosis following irradiation. Also, overexpression of p21(WAF1/CIP1) did not affect the dose-dependent radiation-induced cell lethality as determined by a clonogenic survival assay. These results suggest that bcl-2 downregulation of p21(WAF1/CIP1) is independent of the anti-apoptotic activity of bcl-2, and that p21(WAF/CIP1) is not involved in the p53-mediated cell death pathway.

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December 1997
Volume 11 Issue 6

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

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Spandidos Publications style
Kim H, Li G, Han S, Rahman K, Liu H, Waid D and Lee Y: Levels of p21(WAF1/CIP1) do not affect radiation-induced cell death in human breast epithelial cells. Int J Oncol 11: 1349-1353, 1997.
APA
Kim, H., Li, G., Han, S., Rahman, K., Liu, H., Waid, D., & Lee, Y. (1997). Levels of p21(WAF1/CIP1) do not affect radiation-induced cell death in human breast epithelial cells. International Journal of Oncology, 11, 1349-1353. https://doi.org/10.3892/ijo.11.6.1349
MLA
Kim, H., Li, G., Han, S., Rahman, K., Liu, H., Waid, D., Lee, Y."Levels of p21(WAF1/CIP1) do not affect radiation-induced cell death in human breast epithelial cells". International Journal of Oncology 11.6 (1997): 1349-1353.
Chicago
Kim, H., Li, G., Han, S., Rahman, K., Liu, H., Waid, D., Lee, Y."Levels of p21(WAF1/CIP1) do not affect radiation-induced cell death in human breast epithelial cells". International Journal of Oncology 11, no. 6 (1997): 1349-1353. https://doi.org/10.3892/ijo.11.6.1349