Stat3-siRNA induces Fas-mediated apoptosis in vitro and in vivo in breast cancer

  • Authors:
    • Sateesh Kunigal
    • Sajani S. Lakka
    • Prasanna Kumar Sodadasu
    • Norman Estes
    • Jasti S. Rao
  • View Affiliations

  • Published online on: May 1, 2009     https://doi.org/10.3892/ijo_00000249
  • Pages: 1209-1220
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Abstract

Stat3, a member of the signal transducer and activator of transcription family, has the potential to mediate cell survival, growth and differentiation. Stat3 is constitutively activated in numerous cancers, including >50% of breast cancers. Previous studies demonstrated that constitutively activated Stat3 plays an important role in breast cancer development and progression by promoting cell proliferation and inhibiting apoptosis. The present study was designed to investigate the potential use of RNA interference (RNAi) to block Stat3 expression and activation, as well as the subsequent effect on human breast cancer cell growth. Our studies show that knockdown of STAT3 expression by siRNA reduced expression of Bcl-xL and survivin in MDA-MB-231 cells, and also led to Fas mediated intrinsic apoptotic pathway by activating caspases -8, -9, -3 and PARP1 cleavage. In nude mice, pRNAi-Stat3 significantly suppressed tumor growth compared with controls. It also suppressed Stat3 expression, and downregulated BcL-xL and upregulated Fas, Fas-L and cleaved caspase-3 expression within the tumor, which significantly induced apoptosis and led to tumor suppression. Thus, targeting Stat3 signaling using siRNA may serve as a novel therapeutic strategy for the treatment of breast cancers expressing constitutively activated Stat3.

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May 2009
Volume 34 Issue 5

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

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Spandidos Publications style
Kunigal S, Lakka SS, Sodadasu PK, Estes N and Rao JS: Stat3-siRNA induces Fas-mediated apoptosis in vitro and in vivo in breast cancer. Int J Oncol 34: 1209-1220, 2009
APA
Kunigal, S., Lakka, S.S., Sodadasu, P.K., Estes, N., & Rao, J.S. (2009). Stat3-siRNA induces Fas-mediated apoptosis in vitro and in vivo in breast cancer. International Journal of Oncology, 34, 1209-1220. https://doi.org/10.3892/ijo_00000249
MLA
Kunigal, S., Lakka, S. S., Sodadasu, P. K., Estes, N., Rao, J. S."Stat3-siRNA induces Fas-mediated apoptosis in vitro and in vivo in breast cancer". International Journal of Oncology 34.5 (2009): 1209-1220.
Chicago
Kunigal, S., Lakka, S. S., Sodadasu, P. K., Estes, N., Rao, J. S."Stat3-siRNA induces Fas-mediated apoptosis in vitro and in vivo in breast cancer". International Journal of Oncology 34, no. 5 (2009): 1209-1220. https://doi.org/10.3892/ijo_00000249