CAPE (caffeic acid phenethyl ester)-based propolis extract (Bio 30) suppresses the growth of human neurofibromatosis (NF) tumor xenografts in mice.

Dysfunction of the NF1 gene coding a RAS GAP is the major cause of neurofibromatosis type 1 (NF1), whereas neurofibromatosis type 2 (NF2) is caused primarily by dysfunction of the NF2 gene product called merlin that inhibits directly PAK1, an oncogenic Rac/CDC42-dependent Ser/Thr kinase. It was demonstrated previously that PAK1 is essential for the growth of both NF1 and NF2 tumors. Thus, several anti-PAK1 drugs, including FK228 and CEP-1347, are being developed for the treatment of NF tumors. However, so far no effective NF therapeutic is available on the market. Since propolis, a very safe healthcare product from bee hives, contains anticancer ingredients called CAPE (caffeic acid phenethyl ester) or ARC (artepillin C), depending on the source, both of which block the oncogenic PAK1 signaling pathways, its potential therapeutic effect on NF tumors was explored in vivo. Here it is demonstrated that Bio 30, a CAPE-rich water-miscible extract of New Zealand (NZ) propolis suppressed completely the growth of a human NF1 cancer called MPNST (malignant peripheral nerve sheath tumor) and caused an almost complete regression of human NF2 tumor (Schwannoma), both grafted in nude mice. Although CAPE alone has never been used clinically, due to its poor bioavailability/water-solubility, Bio 30 contains plenty of lipids which solubilize CAPE, and also includes several other anticancer ingredients that seem to act synergistically with CAPE. Thus, it would be worth testing clinically to see if Bio 30 and other CAPE-rich propolis are useful for the treatment of NF patients.

Effect of Aplidin in acute lymphoblastic leukaemia cells.

The cytotoxic effect of Aplidin was investigated on fresh leukaemia cells derived from children with B-cell-precursor (BCP) acute lymphoblastic leukaemia (ALL) by using stromal-layer culture system and on four cell lines, ALL-PO, Reh, ALL/MIK and TOM-1, derived from patients with ALL with different molecular genetic abnormalities. In ALL cell lines Aplidin was cytotoxic at nanomolar concentrations. In the ALL cell lines the drug-induced cell death was clearly related to the induction of apoptosis and appeared to be p53-independent. Only in ALL-PO 20 nM Aplidin treatment caused a block of vascular endothelial growth factor (VEGF) secretion and downregulation of VEGF-mRNA, but Aplidin cytotoxicity does not seem to be related to VEGF inhibition since the sensitivity of ALL-PO cells to Aplidin is comparable to that observed for the other cells used. Aplidin induced a G(1) and a G(2) M block in ALL cell lines. In patient-derived leukaemia cells, Aplidin induced a strong cytotoxicity evidenced in a stroma-supported immunocytometric assay. Cells from children with genetic abnormalities such as t(9;22) and t(4;11) translocations, associated with an inferior treatment outcome, were sensitive to Aplidin to the same extent as that observed in other BCP-ALL cases. Aplidin exerted a strong cell killing effect (>88%) against primary culture cells from five relapsed ALL cases, at concentrations much lower than those reported to be achieved in plasma of patients receiving Aplidin at recommended doses. Taken together these data suggest that Aplidin could be a new anticancer drug to be investigated in ALL patients resistant to available therapy.

Review article: percutaneous treatment of hepatocellular carcinoma.

In early stage hepatocellular carcinoma (HCC), liver transplantation, surgical resection and percutaneous techniques are classified as radical treatments, and may be offered to about 25% of all patients with HCC evaluated in referral centres. The restricted inclusion criteria for surgical resection and the shortage of liver donors for transplantation have stimulated an increasing demand for minimally invasive treatments able to achieve effective and reproducible percutaneous tumour ablation, with less associated morbidity and lower cost than other interventions. Among percutaneous techniques, ethanol injection has proven to be highly effective in single HCC up to 3 cm, with a rate of complete response of 80%, being well tolerated and with a limited risk of minor complication. In larger and/or multinodular HCC the efficacy is reduced to 50% of complete response in nodules between 3 and 5 cm, and to lower rate in larger tumours. Alternative options to ethanol injection have been recently proposed, including radiofrequency, microwave and laser thermal ablation, aimed to extend the necrotic area thus improving the rate of complete response. To date, radiofrequency is the most used technique, with a reported rate of complete response of 90-98% in nodules smaller than 3 cm, and with the advantage of fewer sessions, otherwise counteracted by a higher rate of side-effects. Microwave and laser are promising technologies, but only few clinical data are available. Randomized controlled trials are needed in order to assess treatment response, long-term survival, rate of complication and cost-efficacy of newer technologies in comparison to ethanol injection.

Influence of the spleen on portal haemodynamics: a non-invasive study with Doppler ultrasound in chronic liver disease and haematological disorders.

BACKGROUND: Splanchnic haemodynamic parameters for the differential diagnosis of splenomegalies of different origins are still suboptimal and the role of spleen enlargement in cirrhosis remains controversial. In an attempt to elucidate these questions, we assessed splanchnic haemodynamics in chronic liver diseases and various other disorders with splenomegaly. METHODS: Study groups comprised: (i) patients with chronic liver disease (89 with cirrhosis, 35 with chronic hepatitis), (ii) patients with splenomegaly without relevant portal hypertension (14 with haematological splenomegaly and 25 liver transplant recipients without complications), (iii) 15 patients with arterial hypertension, (iv) 22 healthy controls. In all subjects, spleen size, portal flow parameters and splenic artery resistance index were measured using duplex-Doppler ultrasound. RESULTS: Splenic artery resistance index was significantly and selectively increased in patients with cirrhosis (0.63, whereas all other group means ranged between 0.53 and 0.56; P < 0.01). Portal flow velocity was significantly decreased in cirrhosis (P < 0.01). The combination of these two parameters provided an accuracy of 87.5% in distinguishing portal hypertensive from haematological splenomegaly. In patients with cirrhosis, the degree of spleen enlargement was positively correlated with increasing portal flow volume, portal vein diameter and variceal size, whereas splenic resistance index and portal velocity did not differ in connection with spleen size. CONCLUSIONS: Splenoportal Doppler sonography provides specific findings in cirrhosis and may therefore be a useful tool in differentiating between splenomegaly of portal hypertensive or haematological origin. In patients with cirrhosis, the presence of splenomegaly is associated with the presence of larger oesophageal varices.

Influence of liver fibrosis on hepatic artery Doppler resistance index in chronic hepatitis of viral origin.

BACKGROUND: Hepatic arterial Doppler sonography is increasingly being used in liver diagnostics. The determinants of the elevation of hepatic artery impedance indexes in chronic liver disease, however, have still not been fully clarified. The aim of the present study was to investigate the relationship between histological alterations and liver circulation in chronic hepatitis. METHODS: Hepatic artery resistance index and portal flow velocity were measured using Doppler sonography in 47 patients with chronic hepatitis of viral origin diagnosed at histopathology. The patients were divided into two groups, those with mild and those with severe alterations, in accordance with the various histological parameters of the Knodell scoring system. RESULTS: Hepatic artery resistance index and age were higher in patients with more severe liver fibrosis (respectively 0.638 +/- 0.084 and 39.0 +/- 10.9 (years) in mild fibrosis versus 0.687 +/- 0.060 and 49.4 +/- 14.4 (years) in severe fibrosis; P < 0.05 for both), whereas no difference between the two groups was found for the other histological features (degeneration, inflammation and necrosis), nor for portal flow velocity. CONCLUSIONS: The increase in hepatic artery resistance index appears to be influenced by the extent of fibrous tissue deposition in the liver, determined by chronic inflammation and repair and, secondly, by ageing.

Neutrophil proteases can inactivate human PAR3 and abolish the co-receptor function of PAR3 on murine platelets.

Three members of the protease-activated receptor family, PAR1, PAR3 and PAR4, are activated when thrombin cleaves the receptor N-terminus, exposing a tethered ligand. Proteases other than thrombin can also cleave PAR family members and, depending upon whether this exposes or removes the tethered ligand, either activate or disable the receptor. For example, on human platelets PAR1 is disabled by cathepsin G, although aggregation still occurs because cathepsin G can activate PAR4. The present studies examine the interaction of cathepsin G and a second neutrophil protease, elastase, with PAR3 using two model systems: COS-7 cells transfected with human PAR3 and mouse platelets, which express PAR3 and PAR4, but not PAR1. In contrast to human platelets, cathepsin G did not aggregate murine platelets, and prevented their activation only at low thrombin concentrations. Elastase had no effect on thrombin responses in mouse platelets, but when added to COS cells expressing human PAR3, both cathepsin G and elastase prevented activation of phospholipase C by thrombin. Notably, this inhibition occurred without loss of the binding sites for two monoclonal antibodies that flank the tethered ligand on human PAR3. We therefore conclude that 1) exposure to cathepsin G disables signaling through human PAR3, and prevents murine PAR3 from serving its normal role, which is to facilitate PAR4 cleavage at low thrombin concentrations, 2) elastase disables human, but not murine, PAR3, 3) in contrast to human PAR4, mouse PAR4 will not support platelet aggregation in response to cathepsin G, and 4) the inactivation of human PAR3 by cathepsin G and elastase involves a mechanism other than amputation of the tethered ligand domain. These results extend the range of possible interactions between PAR family members and proteases, and provide further support for species-specific differences in the interaction of these receptors with proteases other than thrombin.

Effect of diet on serum albumin and hemoglobin adducts of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) in humans.

2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is the most abundant heterocyclic amine formed in meat and fish during cooking and can be used as a model compound for this class of chemicals possibly involved in human carcinogenesis. Knowing the exposure to heterocyclic amines is important for establishing their role in human diseases. Serum albumin (SA) and globin (Gb) adducts were first tested as biomarkers of exposure to PhIP in male Fischer 344 rats given oral doses of 0.1, 0.5, 1 and 10 mg/kg. Blood samples were collected 24 hr after treatment and PhIP released from SA and Gb after acidic hydrolysis was analyzed by gas chromatography-mass spectrometry or liquid chromatography-tandem mass spectrometry. PhIP-SA and Gb adducts increased linearly with the dose. Studies on 35 volunteers with different dietary habits exhibited that diet was a major determinant in the formation of both adducts. PhIP-SA adducts were significantly higher in meat consumers than in vegetarians (6.7 +/- 1.6 and 0.7 +/- 0.3 fmol/mg SA; respectively, mean +/- SE; p = 0.04, Mann-Whitney U test). The Gb adduct pattern was quantitatively lower but paralleled SA (3 +/- 0.8 in meat consumers and 0.3 +/- 0.1 in vegetarians). PhIP-SA adducts were no different in smokers and in non-smokers. The results show for the first time that PhIP-blood protein adducts are present in humans not given the synthetic compound. Both biomarkers appear to be suitable for assessing dietary exposure and internal PhIP dose and may be promising tools for studying the role of heterocyclic amines in the etiology of colon cancer and other diseases.

Analysis of aplidine (dehydrodidemnin B), a new marine-derived depsipeptide, in rat biological fluids by liquid chromatography-tandem mass spectrometry.

Aplidine (dehydrodidemnin B) is a new marine-derived depsipeptide with a powerful cytotoxic activity, which is under early clinical investigation in Europe and in the US. In order to investigate the pharmacokinetic properties of this novel drug, an HPLC-tandem mass spectrometry method was developed for the determination of aplidine in biological samples. Didemnin B, a hydroxy analogue, was used as internal standard. After protein precipitation with acetonitrile and extraction with chloroform, aplidine was chromatographed with a RP octadecylsilica column using a water-acetonitrile linear gradient in the presence of formic acid at the flow-rate of 500 microliters/min. The method was linear over a 5-100 ng/ml range (LOD = 0.5 ng/ml) in plasma and over a 1.25-125 ng/ml range (LOD = 0.2 ng/ml) in urine with precision and accuracy below 14.0%. The intra- and inter-day precision and accuracy were below 12.5%. The extraction procedure recoveries for aplidine and didemnin B were 69% and 68%, respectively in plasma and 91% and 87%, respectively in urine. Differences in linearity, LOQ, LOD and recoveries between plasma and urine samples seem to be matrix-dependent. The applicability of the method was tested by measuring aplidine in rat plasma and urine after intravenous treatment.