Knockdown of survivin gene by vector-based short hairpin RNA technique induces apoptosis and growth inhibition in Burkitt's lymphoma Raji cell line

Abstract

Survivin is the smallest member of mammalian IAP (inhibitor of apoptosis) family. It is ubiquitous during embryonic development but is not expressed in normal post-natal tissues, except the thymus, colonic epithelial cells and CD34+ hematopoietic stem cells. However, its expression is upregulated during neoplastic transformation in both solid organ and hematological malignancies, including leukemia and lymphoma. In this study, we used RNA interference with short hairpin RNA (shRNA) technique to inhibit survivin expression in a Burkitt's lymphoma cell line Raji and validated its effects on apoptosis and cell proliferation. A survivin-shRNA expression vector were constructed and introduced into Raji cells. Expression of survivin mRNA and protein was assessed by RT-PCR and western blot analysis. Apoptosis index of transfected cells was quantified by flow cytometry and cell proliferation was enumerated by trypan blue exclusion. In Raji cells treated with survivin-shRNA expression vector, survivin mRNA levels were significantly reduced by 67.14% (transient transfection) and 64.28% (stable transfection) respectively, compared with control-shRNA treated group and PBS treated group (p<0.05). The levels of survivin protein were significantly reduced by 62.50% (transient transfection) and 60.93% (stable transfection), compared with the two control groups (p<0.05). Apoptosis index was significantly increased during transient transfection and stable transfection, respectively 31.20+/-2.45% and 29.40+/-1.72% (p<0.05). Survivin-shRNA inhibited the proliferation of Raji cells of stable transfection. In conclusion, the vector-based survivin-shRNA can effectively reduce the expression of survivin gene and induce apoptosis and growth inhibition of transfected Raji cells. We suggest that survivin can be regarded as an ideal target for new anticancer intervention of NHL.