Significance of heparanase in metastatic lymph nodes of cervical squamous cell cancer

Heparanase-A single protein with multiple enzymatic and nonenzymatic functions

Heparanase (Hpa1) is expressed by tumor cells and cells of the tumor microenvironment and functions extracellularly to remodel the extracellular matrix (ECM) and regulate the bioavailability of ECM-bound factors, augmenting, among other effects, gene transcription, autophagy, exosome formation, and heparan sulfate (HS) turnover. Much of the impact of heparanase on tumor progression is related to its function in mediating tumor-host crosstalk, priming the tumor microenvironment to better support tumor growth, metastasis, and chemoresistance. The enzyme appears to fulfill some normal functions associated, for example, with vesicular traffic, lysosomal-based secretion, autophagy, HS turnover, and gene transcription. It activates cells of the innate immune system, promotes the formation of exosomes and autophagosomes, and stimulates signal transduction pathways via enzymatic and nonenzymatic activities. These effects dynamically impact multiple regulatory pathways that together drive tumor growth, dissemination, and drug resistance as well as inflammatory responses. The emerging premise is that heparanase expressed by tumor cells, immune cells, endothelial cells, and other cells of the tumor microenvironment is a key regulator of the aggressive phenotype of cancer, an important contributor to the poor outcome of cancer patients and a valid target for therapy. So far, however, antiheparanase-based therapy has not been implemented in the clinic. Unlike heparanase, heparanase-2 (Hpa2), a close homolog of heparanase (Hpa1), does not undergo proteolytic processing and hence lacks intrinsic HS-degrading activity, the hallmark of heparanase. Hpa2 retains the capacity to bind heparin/HS and exhibits an even higher affinity towards HS than heparanase, thus competing for HS binding and inhibiting heparanase enzymatic activity. It appears that Hpa2 functions as a natural inhibitor of Hpa1 regulates the expression of selected genes that maintain tissue hemostasis and normal function, and plays a protective role against cancer and inflammation, together emphasizing the significance of maintaining a proper balance between Hpa1 and Hpa2.

Helicobacter pylori promotes invasion and metastasis of gastric cancer by enhancing heparanase expression

AIM

To detect the mechanisms of Helicobacter pylori (H. pylori) infection in the invasion and metastasis of gastric cancer (GC).

METHODS

Specimens from 99 patients with GC were collected. The correlation among H. pylori infection, heparanase (HPA) and mitogen-activated protein kinase (MAPK) expression, which was determined by immunohistochemistry, and the clinical features of GC was analysed using SPSS 22.0. Overall survival (OS) and relapse-free survival (RFS) of GC patients were estimated by the Kaplan-Meier method. Independent and multiple factors of HPA and MAPK with prognosis were determined with COX proportional hazards models. HPA and MAPK expression in MKN-45 cells infected with H. pylori was analysed using Western blot.

RESULTS

H. pylori infection was observed in 70 of 99 patients with GC (70.7%), which was significantly higher than that in healthy controls. H. pylori infection was related to lymph metastasis and expression of HPA and MAPK (P < 0.05); HPA expression was relevant to MAPK expression (P = 0.024). HPA and MAPK expression in MKN-45 cells was significantly upregulated following H. pylori infection and peaked at 24 h and 60 min, before decreasing (P < 0.05). SB203580, an inhibitor of MAPK, significantly decreased HPA expression. HPA was related to lymph metastasis and invasive depth. HPA positive GC cases and H. pylori positive GC cases showed poorer prognosis than HPA negative cases (P < 0.05). COX models showed that the prognosis of GC was connected with HPA expression, lymph metastasis, tissue differentiation, and invasive depth.

CONCLUSION

H. pylori may promote the invasion and metastasis of GC by increasing HPA expression that may associate with MAPK activation, thus causing a poorer prognosis of GC.