Objective According to heparanase’s gene sequence of GenBank, to construct heparanase gene-targeted small interfering RNA (siRNA) and its expression vector and to observe its interference effect on the expression of heparanase gene in human malignant breast cancer MDA-MB-231 cell. Methods Heparanase gene-targeted hairpin siRNA was designed, two complementary oligonucleotide strands were synthesized and inserted into pGPU6/GFP/Neo vector, which was identified by sequence identify. Human malignant breast cancer MDA-MB-231 cell was transfected with the constructed vector with lipofectamine method. Fluorescence photograph was taken. Real-time PCR (RT-PCR) was performed to evaluate the level of heparanase mRNA expression. Results Four kinds of heparanase gene-targeted hairpin siRNA were designed, then were inserted into pGPU6/GFP/Neo vector after annealing. Sequencing indicated the construction was successful. Fluorescence photographs showed MDA-MB-231 cells were transfected successfully. RT-PCR showed that heparanase mRNA expression levels were inhibited significantly （Plt;0.05）. Conclusion The heparanase gene-targeted siRNA and its vector are successfully constructed and MDA-MB-231 cells are transfected successfully. Heparanase mRNA expression levels are significantly inhibited by siRNA vector, which provide a new method for the treatment of cancer.
Objective Heparanase can specifically cleave carbohydrate chains of heparan sulphate proteoglycans, which is an important component of the extracellular matrix. This study was designed to investigate the expression of heparanase in patients with colorectal cancer, and to analyze its relationships with progression of the cancer and clinical prognosis. Methods Samples were collected from 36 patients with colorectal cancers from 2003 to 2004 in Peking Union Medical College Hospital, and were embeded by Paraffin and fresh-frozened. The expression of heparanase mRNA and its protein were measured by RT-PCR and immunohistochemistry. The relationships between these expressions and the clinicopathologic information (tumor invasion, tumor differentiation, lymph node involvement, accompanying with colorectal adenoma and 2-year survival) were also evaluated. Results The expressions of heparanase mRNA in colorectal cancer (19/31， 61.3%) were significantly higher than those in normal colorectal tissues (6.5%). The overexpressions in normal tissues were positively correlated to the incidence of adenoma in patients with colorectal cancer （r=0.352， P=0.024）. The result of immunohistochemistry also showed that heparanase mainly expressed in the vascular endothelium within cancer tissues and the peripheral invased region outside cancer tissues. The 2-year disease-free-survival in patients with negative heparanase expression (88.9%) was higher than that with positive heparanase expression (50.0%), but there was no significant difference （P=0.078）. Conclusion Heparanase overexpressed in colorectal cancer tissues, and thus it may take a role as an indicator for the formation and prognosis of colorectal cancer.