Localization of heparanase in esophageal cancer cells: respective roles in prognosis and differentiation

Abstract

In this study, we examined the distribution of heparanase protein in 75 esophageal squamous cell carcinomas by immunohistochemistry and analyzed the relationship between heparanase expression and clinicopathological characteristics. In situ hybridization showed that the mRNA expression pattern of heparanase was similar to that of the protein, suggesting that increased expression of the heparanase protein at the invasive front was caused by an increase of heparanase mRNA in tumor cells. Heparanase expression correlated significantly with depth of tumor invasion, lymph node metastasis, tumor node metastasis (TNM) stage and lymphatic invasion. Overexpression of heparanase in esophageal cancers was also associated with poor survival. In addition to its localization in the cytoplasm and cell membrane, heparanase was also identified in the nuclei of normal epithelial and tumor cells by immunohistochemistry. Furthermore, nuclear heparanase was detected in nuclear extract of cancer cell lines by Western blot and immunohistochemistry. Examination of the role of nuclear heparanase in cell proliferation and differentiation by double immunostaining for proliferating cell nuclear antigen (PCNA) and cytokeratin 10 (CK10) showed significant relationship between nuclear heparanase expression and differentiation (heparanase vs CK10), but not for proliferative state of esophageal cancer cells (heparanase vs PCNA). Our results suggest that cytoplasmic heparanase appears to be a useful prognostic marker in patients with esophageal cancer and that nuclear heparanase protein may play a role in differentiation. Inhibition of heparanase activity may be effective in the control of esophageal tumor invasion and metastasis.

The endoglycosidase heparanase enters the nucleus of T lymphocytes and modulates H3 methylation at actively transcribed genes via the interplay with key chromatin modifying enzymes

“…25,26 A number of studies have also reported the presence of heparanase in the nucleus of cells, [27][28][29][30] with nuclear heparanase being associated with a favorable prognosis and cytoplasmic heparanase with poor survival in patients with lung, neck and gastric cancers. 31 There is some evidence that nuclear heparanase expression is linked to cell differentiation 28,30,[32][33][34] but, despite such reports, the functional relevance of nuclear heparanase remains to be established.…”

Heparanase expression by Barrett's epithelium and during esophageal carcinoma progression

“…Previous studies showed that heparanase expression is induced in carcinoma of the esophagus. 18,20 Heparanase induction correlated with enhanced tumor cell invasion into the muscular and adventitia layers, increased tumor metastasis, and advanced tumor stage, altogether associated with poor survival. 18,20 High heparanase staining in esophageal adenocarcinoma biopsies noted in this study (Table 1) further supports this notion.…”

“…18,20 Heparanase induction correlated with enhanced tumor cell invasion into the muscular and adventitia layers, increased tumor metastasis, and advanced tumor stage, altogether associated with poor survival. 18,20 High heparanase staining in esophageal adenocarcinoma biopsies noted in this study (Table 1) further supports this notion. Interestingly, however, increased heparanase expression was already noted in Barrett's epithelium, representing the earliest stage of esophagus carcinogenesis (Table 1; Figure 1).…”

“…21,28,[34][35][36][37][38][39] Previous studies have shown that heparanase also assumes nuclear localization, 40,41 and that nuclear heparanase is associated with a favorable prognosis of head and neck, gastric, and esophageal cancer patients. 20,[41][42][43] It was unclear, however, at what stage of tumor initiation/progression nuclear translocation takes place. Likewise, nuclear localization of heparanase was observed in the present study (Figure 2b, c), supporting its prevalence in carcinoma of the esophagus.…”

“…[13][14][15][16][17] Heparanase induction has similarly been observed in carcinoma of the esophagus, and its expression correlated with tumor malignancy and poor survival. [18][19][20][21] Although heparanase upregulation and its pro-malignant features are well documented, the timing of its induction in the course of tumor development is less investigated and understood. Barrett's esophagus is defined as the replacement (metaplasia) of the normal esophageal squamous mucosa with columnar epithelium.…”