The influence of HOXA5-specific siRNA on the expression of Livin and Smac proteins.

OBJECTIVE

To Knockdown Homeobox A5 (HOXA5) expression by HOXA5-specific siRNA and evaluate the effects on Livin and Smac proteins expression in acute T cell leukemia Jurkat cells.

MATERIALS AND METHODS

We designed and constructed HOXA5-specific siRNA, and using liposomes we transfected Jurkat cells with this siRNA. The experiment was designed for three groups: (i) experimental group with Jurkat cells transfected with HOXA5-specific siRNA (siRNA transfection group), (ii) negative control group (irrelevant siRNA transfection) with Jurkat cells transfected with pRNAT-U6.1-siD and (iii) normal control group (untransfected Jurkat cells, only with equivalent amounts of cells and medium). We used FQ-PCR and Western blot to detect the relative expression levels of HOXA5 mRNA and protein in each group separately. The Western blot was also used to detect Livin and Smac protein levels in Jurkat cells.

RESULTS

Expression levels of HOXA5 mRNA and protein were significantly reduced in the group with Jurkat cells transfected with HOXA5 siRNA (p<0.05). The expression of Livin protein was significantly down-regulated (p<0.05) while the expression of Smac protein was significantly up-regulated (p <0.05).

CONCLUSIONS

HOXA5-specific siRNA effectively silenced the HOXA5 gene expression and down-regulation of HOXA5 induced the down-regulation of Livin protein expression and up-regulation of Smac protein. We suggest the HOXA5 gene to be considered as the new target for acute leukemia gene therapy.