Expression of Heparanase in Renal Cell Carcinomas: Implications for Tumor Invasion and Prognosis

Abstract

Purpose: Heparanase activity has been detected in many malignant tumors, showing a correlation with the metastatic potential.The present study was undertaken to investigate the expression of heparanase and its prognostic significance in renal cell carcinomas (RCC). Experimental Design: Nineteen RCCs and 6 nonneoplastic renal tissues were analyzed for heparanase mRNA expression by real-time PCR. Heparanase protein expression was semiquantitatively investigated by immunohistochemistry in 70 RCCs. Involvement of heparanase in the invasiveness of RCC cell lines, 786-O and Caki-2 cells, was examined by down-regulating the gene expression with small interfering RNA (siRNA) using the Matrigel invasion assay. Results: The expression level of heparanase mRNA was significantly higher in clear cell RCCs than in papillary RCCs, chromophobe RCCs, and nonneoplastic renal tissues. Heparanase was predominantly immunolocalized to cell surface and cytoplasm of clear cell RCCs and mean expression levels of heparanase were significantly higher in clear cell RCCs than in papillary and chromophobe RCCs. The protein expression levels were positively correlated with primary tumor stage, distant metastasis, and histologic grade. Targeting of heparanase mRNA expression in 786-O and Caki-2 cells with siRNA down-regulated the mRNA expression and inhibited the Matrigel invasion by these cells, whereas nonsilencing siRNA showed no effect. Multivariate Cox analysis revealed that elevated heparanase expression was a significant and an independent predictor of disease-specific survival (odds ratio, 8.814; P = 0.019). Conclusions: These data suggest that heparanase plays an important role in invasion and metastasis and silencing of the gene might be a potential therapeutic target in clear cell RCCs.Renal cell carcinoma (RCC) is the most common malignancy of the kidney (1), and 20% to 30% of the patients who undergo curative surgery will develop metastatic disease during followup (2). Tumor metastasis depends on the ability of cancer cells to invade tissue barriers composed of basement membrane and extracellular matrix (3). Matrix metalloproteinases (MMP) may play important roles in tumorigenesis and cancer cell progression because they digest the main components of basement membrane and extracellular matrix such as collagens, proteoglycans, laminin, fibronectin, and vitronectin (4). However, studies on MMP expression in RCCs have been limited and have reported variable findings. Kugler et al. (5) reported a strong correlation between increased MMP2, MMP9 expression, and tumor stage in RCCs. In contrast, Lein et al. (6) reported that only MMP9 was increased in RCCs, but it was not correlated with tumor type, grade, or stage.Heparan sulfate proteoglycans, in which heparan sulfate chains are covalently attached, are the components of basement membrane (7). Heparanase is the enzyme that degrades heparan sulfate chains of heparan sulfate proteoglycans and its expression was observed in a variety of malignant tumors where the expression lev...

PG545, a dual heparanase and angiogenesis inhibitor, induces potent anti-tumour and anti-metastatic efficacy in preclinical models

“…Clinical studies have typically noted a poorer prognosis in patients with high expression of heparanase, presumably due to its association with an aggressive, metastatic phenotype (Chen et al , 2008; Mikami et al , 2008; Rivera et al , 2008; Zheng et al , 2009). The pivotal role of VEGF and its receptors in promoting angiogenesis is also well established, and both antibody and small-molecule inhibitors of VEGF signaling have shown clinical utility.…”

“…It also induces VEGF expression (Zetser et al , 2006). The upregulation of HPSE in many tumours has been linked to poor prognosis (Chen et al , 2008; Mikami et al , 2008; Rivera et al , 2008; Zheng et al , 2009). The use of heparin, heparin derivatives, sulfated oligosaccharides and suramin and its analogues to inhibit HPSE activity have shown promise as anti-tumour or anti-metastatic agents (Vlodavsky et al , 1994; Marchetti et al , 2003; Basche et al , 2006; Norrby, 2006).…”

Expression of Snail and Slug in renal cell carcinoma: E-cadherin repressor Snail is associated with cancer invasion and prognosis

“…14 The primers and TaqMan probes sets (TaqMan Gene Expression Assays, Inventoried) for Snail (Hs00195591_m1), Slug (Hs00950344_m1), E-cadherin (Hs001170423_m1), vimentin (Hs00185584_m1), MMP2 (Hs00234422_m1), MMP9 (Hs00234579_m1), MMP14 (Hs00237119_m1) and human b-actin endogenous control (4310881E) were purchased from Applied Biosystems (sequences not disclosed). Ratios of Snail, Slug, E-cadherin, vimentin and MMPs to b-actin mRNA were calculated for each sample to evaluate the relative mRNA expression.…”

Heparan sulfate mimetic PG545-mediated antilymphoma effects require TLR9-dependent NK cell activation

“…Preferential expression of heparanase has been found in various types of cancer, and patients with cancer with high expression levels are considered to have a poor prognosis (5)(6)(7)(8)(9). Heparanase degradation of the ECM not only facilitates intercellular tumor invasion and metastasis via disassembly of extracellular barriers, but also releases HS-bound angiogenic growth factors, such as VEGF, FGF-1, and FGF-2, from the ECM (reviewed in ref.…”