Expression of HPA in human astrocytoma and its effects on invasiveness of tumor cells

LIU Honglei; YI Li; ZHAI Xiaoli

doi:10.3969/j.issn.1002-7386.2016.14.013

Abstract：Objective To investigate the expression of heparanase ( HPA) in human astrocytoma and its effects on invasiveness of tumor cells .Methods The expression levels of HPA were detected by immunohistochemical assay and Real time-PCR in 75 cases of human astrocytoma tissues and 40 cases of normal brain tissues .The small interfering RNA (siRNA) knockdown technique was used to silence the expressions of PHA protein and mRNA in astrocytoma U 87 cells.The expression levels of HPA,vascular endothelium growth factor (VEGF), matrix metalloproteinases-9 (MMP) as well as the changes of invasiveness of tumor cells were detected by Real time-PCR, Western Blot and Transwell assay .Results The expressions of PHA were not observed in normal brain tissues .The positive expression rate of HPA protein was 78.67%(59/75) in astrocytoma tissues, which was significantly higher than that [0(0/40)] in normal brain tissues ( P <0.05), moreover, the positive expression rate of HPA mRNA was significantly higher than that in normal brain tissues ( P <0.05). The positive expression rate of HPA at gradeⅡ~Ⅳof astrocytoma was gradually increased ,and the positive rate was 60.00%(15/25), 79.31% (23/29), 90.48% (19/21),respectively,and there was a significant difference among them ( P <0.05).Furthermore the positive expression rate of HPA in tumor metastasis group was significantly higher than that in non-metastasis group ( P <0.05).The siRNA could effectively inhibit the expressions of HPA in U 87 cells and could down-regulate the expressions of VEGF , MMP-9, at the same time, which could obviously decrease the cell counts of permeating cell membrane ( P <0.05).Conclusion The high-expressions of HPA exist in astrocytoma tissues ,moreover, which are gradually increased with the malignant degree of tumor .The invasiveness of tumor cells is obviously decreased afterHPA is silenced by siRNA ,thus,PHA may become a potential target point in treatment of astrocytoma .