Silencing survivin gene expression promotes apoptosis of human breast cancer cells through a caspase-independent pathway.
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.
Laboratorio de Inmunopatología, Instituto de Biología y Medicina Experimental (IBYME), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina.
Diego O
DO
Croci
Ingrid S
IS
Cogno
Natalia B Rumie
NB
Vittar
Edgardo
E
Salvatierra
Felipe
F
Trajtenberg
Osvaldo L
OL
Podhajcer
Eduardo
E
Osinaga
Gabriel A
GA
Rabinovich
Viviana A
VA
Rivarola
D017209:Apoptosis / Q000187:drug effects; D001943:Breast Neoplasms / Q000188:drug therapy / Q000473:pathology*; D020169:Caspases; D005260:Female; D020868:Gene Silencing / Q000187:drug effects*; D006801:Humans; D051034:Inhibitor of Apoptosis Proteins; D008869:Microtubule-Associated Proteins / Q000235:genetics*; D009363:Neoplasm Proteins / Q000235:genetics*; D034741:RNA, Small Interfering / Q000008:administration & dosage / Q000494:pharmacology; D000077022:Survivin; D014162:Transfection
C107489:BIRC5 protein, human; D051034:Inhibitor of Apoptosis Proteins; D008869:Microtubule-Associated Proteins; D009363:Neoplasm Proteins; D034741:RNA, Small Interfering; D000077022:Survivin; D020169:Caspases