Activity and tumor specificity of human heparanase gene core promoter.

Heparanase (HPSE) plays a critical role in tumor metastasis and vascularization. In addition, the human HPSE promoter has been cloned and characterized. However, the activity and specificity of the HPSE promoter in tumor cells remains unclear. The core fragment of the HPSE promoter was amplified and cloned into the multiple cloning site of the pEGFP-1 vector. The recombinant plasmid pEGFP-Hp was transfected into human umbilical vein endothelial cells (ECV304) and human hepatoma carcinoma (HepG2), laryngocarcinoma (Hep2) and chronic myelogenous leukemia (K562) cell lines. The vectors pEGFP-1 and pEGFP‑N1 were used as negative and positive controls, respectively. The activity and expression of green fluorescent protein (GFP) were analyzed. Results showed that the sequence of the amplified HPSE promoter was in agreement with the GenBank data. The recombinant plasmid pEGFP-Hp was consistent with the expected result. No GFP expression was observed in the transfected cells in the pEGFP-1 group, but a high expression was observed in the pEGFP-N1 group. As regards the pEGFP-Hp group, less fluorescence was revealed in ECV cells with a relatively high fluorescence in tumor cells. The average transfection efficiencies of pEGFP-Hp in the ECV304, HepG2, Hep2 and K562 cell lines were 3.9, 21.3, 10.8 and 6.5%, respectively, while those of pEGFP-Nl were 17.1, 24.0, 14.0 and 11.0%, respectively. The HPSE gene promoter drives the expression of downstream genes in a eukaryotic vector, specifically in tumor cell lines, but its activity is relatively weak.