High glucose induced c-Met activation promotes aggressive phenotype and regulates expression of glucose metabolism genes in HCC cells

Hepatocellular carcinoma (HCC) is strongly associated with metabolic dysregulations/deregulations and hyperglycemia is a common metabolic disturbance in metabolic diseases. Hyperglycemia is defined to promote epithelial to mesenchymal transition (EMT) of cancer cells in various cancers but its molecular contribution to HCC progression and aggressiveness is relatively unclear. In this study, we analyzed the molecular mechanisms behind the hyperglycemia-induced EMT in HCC cell lines. Here, we report that high glucose promotes EMT through activating c-Met receptor tyrosine kinase via promoting its ligand-independent homodimerization. c-Met activation is critical for high glucose induced acquisition of mesenchymal phenotype, survival under high glucose stress and reprogramming of cellular metabolism by modulating glucose metabolism gene expression to promote aggressiveness in HCC cells. The crucial role of c-Met in high glucose induced EMT and aggressiveness may be the potential link between metabolic syndrome-related hepatocarcinogenesis and/or HCC progression. Considering c-Met inhibition in hyperglycemic patients would be an important complementary strategy for therapy that favors sensitization of HCC cells to therapeutics.

Pleiotropic Effects of Heparins: From Clinical Applications to Molecular Mechanisms in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a major health problem worldwide and most cases are incurable because of late presentation. It is the most common primary neoplasm of the liver and often arises in the context of a chronic liver disease that impairs coagulation. Portal vein thrombosis (PVT) is a common complication of HCC that is associated with a poor prognosis. Heparin derivatives are widely used in the management of venous thromboembolism (VTE). Among them low molecular weight heparin (LMWH) favorably influences the survival in patients with advanced cancer, including HCC. Due to their pleiotropic function, heparins affect tumorigenesis in many ways and may promote or hamper tumorigenic transformation depending on the cancer type and cancer stage along with their structural properties and concentration. Thus, their application as an antithrombotic along with the conventional therapy regime should be carefully planned to develop the best management strategies. In this review, we first will briefly review clinical applications of heparin derivatives in the management of cancer with a particular focus on HCC. We then summarize the state of knowledge whereby heparin can crosstalk with molecules playing a role in hepatocarcinogenesis. Lastly, we highlight new experimental and clinical research conducted with the aim of moving towards personalized therapy in cancer patients at risk of thromboembolism.

The regulatory role of heparin on c-Met signaling in hepatocellular carcinoma cells

The role of heparin as an anticoagulant is well defined; however, its role in tumorigenesis and tumor progression is not clear yet. Some studies have shown that anticoagulant treatment in cancer patients improve overall survival, however, recent clinical trials have not shown a survival benefit in cancer patients receiving heparin treatment. In our previous studies we have shown the inhibitory effects of heparin on Hepatocyte Growth Factor (HGF)-induced invasion and migration in hepatocellular carcinoma (HCC) cells. In this study, we showed the differential effects of heparin on the behaviors of HCC cells based on the presence or absence of HGF. In the absence of HGF, heparin activated HGF/c-Met signaling and promoted motility and invasion in HCC cells. Heparin treatment led to c-Met receptor dimerization and activated c-Met signaling in an HGF independent manner. Heparin-induced c-Met activation increased migration and invasion through ERK1/2, early growth response factor 1 (EGR1) and Matrix Metalloproteinases (MMP) axis. Interestingly, heparin modestly decreased the proliferation of HCC cells by inhibiting activatory phosphorylation of Akt. The inhibition of c-Met signaling reversed heparin-induced increase in motility and invasion and, proliferation inhibition. Our study provides a new perspective into the role of heparin on c-Met signaling in HCC.

Protective effect of curcumin on priapism and ischemia-reperfusion injury in rats

OBJECTIVE

We aimed to identify the oxidative stress effects of the ischemic priapism on cavernosal tissues and to assess the biochemical and histopathological effects of curcumin in rats.

MATERIALS AND METHODS

26 adult male Sprague Dawley rats were randomly divided into three groups. Group 1 (Control, n = 8): only penectomy was performed and 3 ml blood samples were obtained from the vena cava inferior (VCI). Group 2 (ischemia-reperfusion group; n= 8): penectomy was performed after 1 hour ischemic priapism + 30 min reperfusion and 3 ml blood samples were obtained from the VCI. Group III (IR + CURC group, n = 10): 200 mg/kg/day curcumin per orally before surgery for 7 days + penectomy after 1 hour ischemic priapism + 30 min reperfusion and 3 ml blood samples from the VCI. Total oxidant status (TAS), total antioxidant status (TAS) and paraoxonase (PON1) levels were measured. Tissue samples were investigated and scored histopathologically in terms of bleeding, edema and necrosis.

RESULTS

TOS levels were higher (p = 0.002), and TAS levels were lower (p = 0.001) in the IR group compared to the control group. As a result of curcumin treatment, TAS levels were increased (p = 0.003), and TOS levels were decreased (p = 0.004) in the IR + CURC group compared to the IR group. In the treatment group (IR + CURC) TAS and TOS levels were similar to levels in the control group. PON1 levels were increased with ischemia-reperfusion (p = 0.21) and decreased with curcumin treatment (p = 0.53), however these changes were not statistically significant. There was no significant difference in the effects of curcumin on histopathological changes.

CONCLUSIONS

This study showed that curcumin has preventive effects on oxidative stress parameters against ischemia-reperfusion injury.