Silencing survivin gene expression promotes apoptosis of human breast cancer cells through a caspase-independent pathway

• Published in: Journal of cellular biochemistry Vol. 105; no. 2; pp. 381 - 390
• Main Authors: Croci, Diego O., Cogno, Ingrid S., Vittar, Natalia B. Rumie, Salvatierra, Edgardo, Trajtenberg, Felipe, Podhajcer, Osvaldo L., Osinaga, Eduardo, Rabinovich, Gabriel A., Rivarola, Viviana A.
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01.10.2008
• Subjects: apoptosis; Apoptosis - drug effects; apoptosis inducing factor (AIF); breast cancer; Breast Neoplasms - drug therapy; Breast Neoplasms - pathology; Caspases; Female; Gene Silencing - drug effects; Humans; Inhibitor of Apoptosis Proteins; Microtubule-Associated Proteins - genetics; Neoplasm Proteins - genetics; RNA, Small Interfering - administration & dosage; RNA, Small Interfering - pharmacology; small interfering RNA (siRNA); survivin; Transfection
• ISSN: 0730-2312; 1097-4644
• DOI: 10.1002/jcb.21836

Survivin is recognized as an attractive target in cancer therapy because of its selective overexpression in the majority of tumors. Upregulated expression of this protein correlates with increased tumor grade, recurrence risk and decreased cancer patients survival. In this study, we assessed the efficacy of two survivin‐specific small interfering RNA (siRNA) constructs to inhibit T47D human breast cancer cell growth. After siRNA transfection, T47D cells showed a significant reduction in proliferation and survival exhibiting clear signs of apoptosis. pSil_1 that targeted exon 1 exhibited a stronger inhibitory effect on cell growth, and increased cell apoptosis compared to pSil_30 that targeted exon 4. Cell apoptosis was found to be mediated by translocation of the mitochondrial apoptosis inducing factor (AIF), while no changes were observed in caspase‐3 activation and Bid cleavage. Thus, silencing survivin expression using siRNA strategies represents a suitable therapeutic approach to selectively modulate the survival and growth of human breast cancer cells. J. Cell. Biochem. 105: 381–390, 2008. © 2008 Wiley‐Liss, Inc.