Effects of heparanase inhibition by RNA interference on proliferation, invasiveness and apoptosis of lung cancer cells

Abstract

To investigate the effects of heparanase expression inhibition on the proliferation, invasiveness and apoptosis of human lung adenocarcinoma cell line A549 cells. Recombinant eukaryotic expression plasmid pshRNA-Hpa targeting human heparanase gene was constructed. A549 cells were cultured in DMEM and transfected with pshRNA-Hpa. The expression of heparanase mRNA and protein were examined by RT-PCR and Western blot. The proliferation, invasiveness and apoptotic rates of A549 cells were determined by MTT method, matrigel invasion assays and flow cytometry respectively. The expression levels of heparanase mRNA and protein were down-regulated in A549 transfected with pshRNA-Hpa. The number of cells penetrating matrigel and the proliferation ability of A549 cells transfected with pshRNA-Hpa were reduced significantly compared to the control cells. The apoptotic rate of A549 cells transfected with pshRNA-Hpa was 12.53% +/- 0.34%, being significantly higher than that of the control cells (both P < 0.01). Western-blot showed that inhibition of heparanase expression led to reduced Akt phosphorylation. The recombinant plasmid pshRNA-Hpa effectively inhibited the expression of heparanase, thus suppressing the proliferation and invasion and inducing apoptosis of A549 cells. The effects may be due to the down-regulation of Akt phosphorylation level.