Potentiation of the anticancer effect of valproic acid, an antiepileptic agent with histone deacetylase inhibitory activity, by the kinase inhibitor Staurosporine or its clinically relevant analogue UCN-01

Histone deacetylase inhibitors (HDACIs) are novel anticancer agents with potent cytotoxicity against a wide range of malignancies. We have previously demonstrated that either Calphostin C (CC) (a protein kinase C (PKC) inhibitor) or Parthenolide (an NF-κB inhibitor) abrogates HDACI-induced transcriptional activation of NF-κB and p21, which is associated with profound potentiation of HDACI-mediated induction of apoptosis. Valproic acid (VA), a commonly used antiepileptic agent, has recently been shown to be an HDACI. This study was aimed to evaluate the anticancer property of VA in thoracic cancer cells and the development of clinically relevant strategies to enhance VA-mediated induction of apoptosis using kinase inhibitors Staurosporine (STP) or its analogue UCN-01. Treating cultured thoracic cancer cells with VA (0.62–10.0 mM) resulted in significant cell line- and dose-dependent growth inhibition (IC50 values: 4.1–6.0 mM) and cell cycle arrest at G1/S checkpoint with profound accumulation of cells at G0/G1 phase but little induction of apoptosis. Valproic acid, being an HDACI, caused significant dose-dependent accumulation of hyperacetylated histones, following 24 h of treatment. Valproic acid-mediated 5–20-fold upregulation of transcriptional activity of NF-κB was substantially (50–90%) suppressed by cotreatment with CC, STP or UCN-01. Whereas minimal death (<20%) was observed in cells treated with either VA (1.0 or 5.0 mM) alone or kinase inhibitors alone, 60–90% of cells underwent apoptosis following exposure to combinations of VA+kinase inhibitors. Kinase inhibitor-mediated suppression of NF-κB transcriptional activity played an important role in sensitising cancer cells to VA as direct inhibition of NF-κB by Parthenolide drastically synergised with VA to induce apoptosis (VA+Parthenolide: 60–90% compared to <20% following single-drug treatments). In conclusion, VA, a well-known antiepileptic drug, has mild growth-inhibitory activity on cultured cancer cells. The weak VA-mediated induction of apoptosis of thoracic cancer cells can be profoundly enhanced either by Parthenolide, a pharmacologic inhibitor of NF-κB, or by UCN-01 a kinase inhibitor that has already undergone phase I clinical development. Combinations of VA with either a PKC inhibitor or an NF-κB inhibitor are promising novel molecularly targeted therapeutics for thoracic cancers

Heparanase Levels Are Elevated in the Urine and Plasma of Type 2 Diabetes Patients and Associate with Blood Glucose Levels

Heparanase is an endoglycosidase that specifically cleaves heparan sulfate side chains of heparan sulfate proteoglycans. Utilizing an ELISA method capable of detection and quantification of heparanase, we examined heparanase levels in the plasma and urine of a cohort of 29 patients diagnosed with type 2 diabetes mellitus (T2DM), 14 T2DM patients who underwent kidney transplantation, and 47 healthy volunteers. We provide evidence that heparanase levels in the urine of T2DM patients are markedly elevated compared to healthy controls (1162±181 vs. 156±29.6 pg/ml for T2DM and healthy controls, respectively), increase that is statistically highly significant (P<0.0001). Notably, heparanase levels were appreciably decreased in the urine of T2DM patients who underwent kidney transplantation, albeit remained still higher than healthy individuals (P<0.0001). Increased heparanase levels were also found in the plasma of T2DM patients. Importantly, urine heparanase was associated with elevated blood glucose levels, implying that glucose mediates heparanase upregulation and secretion into the urine and blood. Utilizing an in vitro system, we show that insulin stimulates heparanase secretion by kidney 293 cells, and even higher secretion is observed when insulin is added to cells maintained under high glucose conditions. These results provide evidence for a significant involvement of heparanase in diabetic complications

Effect of sulodexide on endothelial glycocalyx and vascular permeability in patients with type 2 diabetes mellitus

Endothelial glycocalyx perturbation contributes to increased vascular permeability. In the present study we set out to evaluate whether: (1) glycocalyx is perturbed in individuals with type 2 diabetes mellitus, and (2) oral glycocalyx precursor treatment improves glycocalyx properties. Male participants with type 2 diabetes (n = 10) and controls (n = 10) were evaluated before and after 2 months of sulodexide administration (200 mg/day). The glycocalyx dimension was estimated in two different vascular beds using sidestream dark field imaging and combined fluorescein/indocyanine green angiography for sublingual and retinal vessels, respectively. Transcapillary escape rate of albumin (TER(alb)) and hyaluronan catabolism were assessed as measures of vascular permeability. Both sublingual dimensions (0.64 [0.57-0.75] μm vs 0.78 [0.71-0.85] μm, p <0.05, medians [interquartile range]) and retinal glycocalyx dimensions (5.38 [4.88-6.59] μm vs 8.89 [4.74-11.84] μm, p <0.05) were reduced in the type 2 diabetes group compared with the controls whereas TER(alb) was increased (5.6 ± 2.3% vs 3.7 ± 1.7% in the controls, p <0.05). In line with these findings, markers of hyaluronan catabolism were increased with diabetes (hyaluronan 137 ± 29 vs 81 ± 8 ng/ml and hyaluronidase 78 ± 4 vs 67 ± 2 U/ml, both p <0.05). Sulodexide increased both the sublingual and retinal glycocalyx dimensions in participants with diabetes (to 0.93 [0.83-0.99] μm and to 5.88 [5.33-6.26] μm, respectively, p <0.05). In line, a trend towards TER(alb) normalisation (to 4.0 ± 2.3%) and decreases in plasma hyaluronidase (to 72 ± 2 U/ml, p <0.05) were observed in the diabetes group. Type 2 diabetes is associated with glycocalyx perturbation and increased vascular permeability, which are partially restored following sulodexide administration. Further studies are warranted to determine whether long-term treatment with sulodexide has a beneficial effect on cardiovascular risk. www.trialregister.nl NTR780/ http://isrctn.org ISRCTN82695186 An unrestricted Novartis Foundation for Cardiovascular Excellence grant (2006) to M. Nieuwdorp/E. S. G. Stroes, Dutch Heart Foundation (grant number 2005T037

Microenvironmental Influences that Drive Progression from Benign Breast Disease to Invasive Breast Cancer

Invasive breast cancer represents the endpoint of a developmental process that originates in the terminal duct lobular units and is believed to progress through stages of increasing proliferation, atypical hyperplasia, and carcinoma in situ before the cancer acquires invasive and metastatic capabilities. By comparison with invasive breast cancer, which has been studied extensively, the preceding stages of benign breast disease are more poorly understood. Much less is known about the molecular changes underlying benign breast disease development and progression, as well as the transition from in situ into invasive disease. Even less focus has been given to the specific role of stroma in this progression. The reasons for lack of knowledge about these lesions often come from their small size and limited sample availability. More challenges are posed by limitations of the models used to investigate the lesions preceding invasive breast cancer. However, recent studies have identified alterations in stromal cell function that may be critical for disease progression from benign disease to invasive cancer: key functions of myoepithelial cells that maintain tissue structure are lost, while tissue fibroblasts become activated to produce proteases that degrade the extracellular matrix and trigger the invasive cellular phenotype. Gene expression profiling of stromal alterations associated with disease progression has also identified key transcriptional changes that occur early in disease development. In this review, we will summarize recent studies showing how stromal factors can facilitate progression of ductal carcinoma in situ to invasive disease. We also suggest approaches to identify processes that control earlier stages of disease progression

Anti-Heparanase Aptamers as Potential Diagnostic and Therapeutic Agents for Oral Cancer

Peer reviewe

Reactive oxygen species mediate high glucose-induced heparanase-1 production and heparan sulphate proteoglycan degradation in human and rat endothelial cells: a potential role in the pathogenesis of atherosclerosis.

Item does not contain fulltextAIMS/HYPOTHESIS: The content of heparan sulphate is reduced in the endothelium under hyperglycaemic conditions and may contribute to the pathogenesis of atherosclerosis. Heparanase-1 (HPR1) specifically degrades heparan sulphate proteoglycans. We therefore sought to determine whether: (1) heparan sulphate reduction in endothelial cells is due to increased HPR1 production through increased reactive oxygen species (ROS) production; and (2) HPR1 production is increased in vivo in endothelial cells under hyperglycaemic and/or atherosclerotic conditions. METHODS: HPR1 mRNA and protein levels in endothelial cells were analysed by RT-PCR and Western blot or HPR1 enzymatic activity assay, respectively. Cell surface heparan sulphate levels were analysed by FACS. HPR1 in the artery from control rats and a rat model of diabetes, and from patients under hyperglycaemic and/or atherosclerotic conditions was immunohistochemically examined. RESULTS: High-glucose-induced HPR1 production and heparan sulphate degradation in three human endothelial cell lines, both of which were blocked by ROS scavengers, glutathione and N-acetylcysteine. Exogenous H(2)O(2) induced HPR1 production, subsequently leading to decreased cell surface heparan sulphate levels. HPR1 content was significantly increased in endothelial cells in the arterial walls of a rat model of diabetes. Clinical studies revealed that HPR1 production was increased in endothelial cells under hyperglycaemic conditions, and in endothelial cells and macrophages in atherosclerotic lesions. CONCLUSIONS/INTERPRETATION: Hyperglycaemia induces HPR1 production and heparan sulphate degradation in endothelial cells through ROS. HPR1 production is increased in endothelial cells from a rat model of diabetes, and in macrophages in the atherosclerotic lesions of diabetic and non-diabetic patients. Increased HPR1 production may contribute to the pathogenesis and progression of atherosclerosis.1 juni 201

Heparanase induces a differential loss of heparan sulphate domains in overt diabetic nephropathy.

Contains fulltext : 70080.pdf (publisher's version ) (Closed access)AIMS/HYPOTHESIS: Recent studies suggest that loss of heparan sulphate in the glomerular basement membrane (GBM) of the kidney with diabetic nephropathy is due to the increased production of heparanase, a heparan sulphate-degrading endoglycosidase. Our present study addresses whether heparan sulphate with different modifications is differentially reduced in the GBM and whether heparanase selectively cleaves heparan sulphate with different domain specificities. METHODS: The heparan sulphate content of renal biopsies (14 diabetic nephropathy, five normal) were analysed by immunofluorescence staining with four anti-heparan sulphate antibodies: JM403, a monoclonal antibody (mAb) recognising N-unsubstituted glucosamine residues; two phage display-derived single chain antibodies HS4C3 and EW3D10, defining sulphated heparan sulphate domains; and anti-K5 antibody, an mAb recognising unmodified heparan sulphate domains. RESULTS: We found that modified heparan sulphate domains (JM403, HS4C3 and EW3D10), but not unmodified domains (anti-K5) and agrin core protein were reduced in the GBM of kidneys from patients with diabetic nephropathy, compared with controls. Glomerular heparanase levels were increased in diabetic nephropathy kidneys and inversely correlated with the amounts of modified heparan sulphate domains. Increased heparanase production and loss of JM403 staining in the GBM correlated with the severity of proteinuria. Loss of modified heparan sulphate in the GBM as a result of degradation by heparanase was confirmed by heparan sulphate staining of heparanase-treated normal kidney biopsy specimens. CONCLUSIONS/INTERPRETATION: Our data suggest that loss of modified heparan sulphate in the GBM is mediated by an increased heparanase presence and may play a role in the pathogenesis of diabetes-induced proteinuria