Immunohistochemical expression of heparanase isoforms and syndecan-1 proteins in colorectal adenomas

Heparanase modulation by Wingless/INT (Wnt)

Heparanase is an endo-beta-glucuronidase, the only enzyme in mammals capable of cleaving heparan sulfate/heparin chains from proteoglycans. The oligosaccharides generated by heparanase present extensive biological functions since such oligosaccharides interact with adhesion molecules, growth factors, angiogenic factors and cytokines, modulating cell proliferation, migration, inflammation, and carcinogenesis. However, the regulation of heparanase activity is not fully understood. It is known that heparanase is synthesized as an inactive 65 kDa isoform and that post-translation processing forms an active 50 kDa enzyme. In the present study, we are interested in investigating whether heparanase is regulated by its own substrate as observed with many other enzymes. Wild-type Chinese hamster (Cricetulus griséus) ovary cells (CHO-K1) were treated with different doses of heparin. Heparanase expression was analyzed by Real-time PCR and flow cytometry. Also, heparanase activity was measured. The heparanase activity assay was performed using a coated plate with biotinylated heparan sulfate. In the present assay, a competitive heparin inhibition scenario was set aside. Exogenous heparin trigged a cell signaling pathway that increased heparanase mRNA and protein levels. The Wnt/beta-catenin pathway, judged by TCF-driven luciferase activity, seems to be involved to enhance heparanase profile during treatment with exogenous heparin. Lithium chloride treatment, an activator of the Wnt/beta-catenin pathway, confirmed such mechanism of transduction in vivo using zebrafish embryos and in vitro using CHO-K1 cells. Taken together the results suggest that heparin modulates heparanase expression by Wnt/beta-catenin.

Novel approach for quantification of multiple immunofluorescent signals using histograms and 2D plot profiling of whole-section panoramic images

We describe a novel approach for quantification and colocalization of immunofluorescence (IF) signals of multiple markers on high-resolution panoramic images of serial histological sections utilizing standard staining techniques and readily available software for image processing and analysis. Human gingiva samples stained with primary antibodies against the common leukocyte antigen CD45 and factors related to heparan sulfate glycosaminoglycans (HS GAG) were used. Expression domains and spatial gradients of IF signals were quantified by histograms and 2D plot profiles, respectively. The importance of histomorphometric profiling of tissue samples and IF signal thresholding is elaborated. This approach to quantification of IF staining utilizes pixel (px) counts and comparison of px grey value (GV) or luminance. No cell counting is applied either to determine the cellular content of a given histological section nor the number of cells positive to the primary antibody of interest. There is no selection of multiple Regions-Of-Interest (ROIs) since the entire histological section is quantified. Although the standard IF staining protocol is applied, the data output enables colocalization of multiple markers (up to 30) from a given histological sample. This can serve as an alternative for colocalization of IF staining of multiple primary antibodies based on repeating cycles of staining of the same histological section since those techniques require non standard staining protocols and sophisticated equipment that can be out of reach for small laboratories in academic settings. Combined with the data from ontological bases, this approach to quantification of IF enables creation of in silico virtual disease models.

The Good and Bad Sides of Heparanase-1 and Heparanase-2

In this chapter, we will emphasize the importance of heparan sulfate proteoglycans (HSPG) in controlling various physiological and pathological molecular mechanisms and discuss how the heparanase enzyme can modulate the effects triggered by HSPG. Additionally, we will also navigate about the existing knowledge of the possible role of heparanase-2 in biological events. Heparan sulfate is widely distributed and evolutionarily conserved, evidencing its vital importance in cell development and functions such as cell proliferation, migration, adhesion, differentiation, and angiogenesis. During remodeling of the extracellular matrix, the breakdown of heparan sulfate by heparanase results in the release of molecules containing anchored glycosaminoglycan chains of great interest in heparanase-mediated cell signaling pathways in various physiological states, tumor development, inflammation, and other diseases. Taken together, it appears that heparanase plays a key role in the maintenance of the pathology of cancer and inflammatory diseases and is a potential target for anti-cancer therapies. Therefore, heparanase inhibitors are currently being examined in clinical trials as novel cancer therapeutics. Heparanase-2 has no enzymatic activity, displays higher affinity for heparan sulfate and the coding region alignment shows 40% identity with the heparanase gene. Heparanase-2 plays an important role in embryogenic development however its mode of action and biological function remain to be elucidated. Heparanase-2 functions as an inhibitor of the heparanase-1 enzyme and also inhibits neovascularization mediated by VEGF. The HPSE2 gene is repressed by the Polycomb complex, together suggesting a role as a tumor suppressor.

Salvianolic acid B attenuates renal interstitial fibrosis by regulating the HPSE/SDC1 axis

Salvianolic acid B (Sal B) is one of the main water-soluble components of Salvia miltiorrhiza Bge. Numerous reports have demonstrated that it could exert significant renal-protective effects, but the underlying mechanism remains unclear. The present study demonstrated that Sal B could alleviate renal injury by regulating the heparanase/syndecan-1 (HPSE/SDC1) axis. In vivo, the serum creatinine, blood urea nitrogen, transforming growth factor-β1 (TGF-β1) and fibroblast growth factor-2 (FGF-2) levels, and the histopathological changes of mice kidneys were examined. Sal B could notably reduce the renal injury caused by left ureteral ligation. In vitro, Sal B downregulated the expression levels of HPSE/FGF-2/TGF-β1/α-smooth muscle actin and upregulated the expression levels of SDC1/E-cadherin in angiotensin II-stimulated HK-2 cells in a dose-dependent manner. In summary, to the best of the authors' knowledge, the present study provided evidence for the first time that Sal B could exert renal-protective effects via the inhibition of the HPSE/SDC1 axis, and these results suggest that the administration of Sal B may be a novel therapeutic strategy in treating renal interstitial fibrosis.

Antitumor activity and structure-activity relationship of heparanase inhibitors: Recent advances

Heparanase (HPSE)-directed tumor progression plays a crucial role in mediating tumor-host crosstalk and priming the tumor microenvironment, leading to tumor growth, metastasis and chemo-resistance. HPSE-mediated breakdown of structural heparan sulfate (HS) networks in the extracellular matrix (ECM) and basement membranes (BM) directly facilitates tumor growth and metastasis. Lysosome HPSE also induces multi-drug resistance via enhanced autophagy. Therefore, HPSE inhibitors development has become an attractive topic to block tumor growth and metastasis or eliminate drug resistance. In this review, we summarize HPSE inhibitors applied experimentally and clinically according to interaction with the binding sites of HPSE and participation of growth factors. The antitumor activity and structure-activity relationship (SAR) are also emphasized.

Histochemistry as a versatile research toolkit in biological research, not only an applied discipline in pathology

The impressive progress of histochemistry over the last 50 years has led to setting up specific and sensitive techniques to describe dynamic events, through the detection of specific molecules in the very place where they exist in live cells. The scientific field where histochemistry has most largely been applied is histopathology, with the aim to identify disease-specific molecular markers or to elucidate the etiopathological mechanisms. Numerous authors did however apply histochemistry to a variety of other research fields; their interests range from the microanatomy of animal and plant organisms to the cellular mechanisms of life. This is especially apparent browsing the contents of the histochemical journals where the articles on subjects other than pathology are the majority; these journals still keep a pivotal role in the field of cell and tissue biology, while being a forum for a diverse range of biologists whose scientific interests expand the research horizon of histochemistry to ever novel subjects. Thus, histochemistry can always receive inspiring stimuli toward a continuous methodological refinement.

Elevated heparanase expression is associated with poor prognosis in breast cancer: a study based on systematic review and TCGA data

Heparanase promotes tumorigenesis, angiogenesis, and metastasis. Here, we conducted a study based on systematic review and the Cancer Genome Atlas (TCGA) data that examined heparanase expression in clinical samples to determine its prognostic value. According to the meta-analysis and TCGA data, we found that heparanase expression was up-regulated in most breast cancer specimens, and elevated heparanase expression was associated with increased lymph node metastasis, larger tumor size, higher histological grade, and poor survival. These results suggest that targeting heparanase might improve treatments for breast cancer patients.

Heparanase overexpression down-regulates syndecan-1 expression in a gallbladder carcinoma cell line

Objective

To discuss the relevance of heparanase and syndecan-1 and regulation of the heparanase-syndecan1 axis in the invasiveness of gallbladder carcinoma cells.

Methods

1. Generation of a gallbladder cancer cell line overexpressing a heparanase (GBD-SD) transgene. 2. Western blot analysis of syndecan-1 levels of GBD-SD and control gallbladder carcinoma (GBC-SD) cells. 3. RT-PCR analysis of syndecan-1 mRNA levels of GBD-SD and GBC-SD. 4. Evaluation of invasion and migration of GBD-SD and GBC-SD cells.

Results

1. Heparanase expression in GBD-SD cells was significantly increased. 2. The syndecan-1 mRNA level of GBD-SD cells was significantly lower compared with that of GBC-SD cells. 3. The syndecan-1 DNA copy number in GBD-SD cells was significantly lower compared with that of GBC-SD. 4. The invasiveness and migration of GBD-SD cells were significantly higher compared with GBC-SD cells.

Conclusions

1. The expression of heparanase negatively correlated with that of syndecan-1 in a gallbladder carcinoma cell line. 2. The expression of heparanase and syndecan-1 in gallbladder carcinomas negatively correlated, similar to other tumours. 3. The heparanase/syndecan1 axis in gallbladder carcinoma plays an important role in the invasion and metastasis, thus providing a new therapeutic target. 4. Further research is required to identify the detailed mechanisms.

Is there still room for novelty, in histochemical papers?

Histochemistry continues to be widely applied in biomedical research, being nowadays mostly addressed to detect and locate single molecules or molecular complexes inside cells and tissues, and to relate structural organization and function at the high resolution of the more advanced microscopical techniques. In the attempt to see whether histochemical novelties may be found in the recent literature, the articles published in the European Journal of Histochemistry in the period 2014-2016 have been reviewed. In the majority of the published papers, standardized methods have been preferred by scientists to make their results reliably comparable with the data in the literature, but several papers (approximately one fourth of the published articles) described novel histochemical methods and procedures. It is worth noting that there is a growing interest for minimally-invasive in vivo techniques (magnetic resonance imaging, autofluorescence spectroscopy), which may parallel conventional histochemical analyses to acquire evidence not only on the morphological features of living organs and tissues, but also on their functional, biophysical and molecular characteristics. Thanks to this unceasing methodological refinement, histochemistry will continue to provide innovative applications in the biomedical field.