1,721,145 research outputs found
Detection of vitellogenin in a subpopulation of sea urchin coelomocytes
Full text linkSea urchin vitellogenin is a high molecular weight glycoprotein, which is the precursor of the major yolk protein present in the unfertilized egg. Vitellogenin processing into the major yolk protein and its further enzymatic cleavage during sea urchin embryonic development, has been extensively described, and the adhesive properties of the processed molecule have been studied. The function of vitellogenin in the adult, where it has been found in the coelomic fluid of both male and female individuals, is still unknown, although its role on promoting the adhesion of embryonic cells has been shown. In this report we describe the detection of vitellogenin in lysates of whole circulating coelomocytes of both male and female sea urchins of the species Paracentrotus lividus. By metrizoic acid gradients we purified total coelomocytes into six subpopulations that were tested for the occurrence of the molecule using vitellogenin-specific polyclonal antibodies. We detected vitellogenin only in the coelomocyte subpopulation called colorless spherule cells, packed in kidney-shaped granules located around the nucleus. We also showed that coelomocytes respond to stress conditions by discharging vitellogenin into the medium. This result together with previous observations on the adhesive properties of the molecule suggest a role for vitellogenin in the clotting phenomenon occurring after host invasion
Spontaneous cytotoxic activity of eosinophilic granule cells separated from the normal peritoneal cavity of Dicentrarchus labrax
No full textIn this study the spontaneous in vitro cytotoxic activity to tumour cell lines, (K562), by unstimulated sea bass (Dicentrarchus labrax) leukocytes was examined by trypan blue exclusion test and lactate dehydrogenase release assay. A high anti-tumour cell line activity of resident peritoneal leukocytes was found at an effector to target ratio (E:T) of 25:1 after incubation for 2 h at 18° C. Rabbit and sheep erythrocytes were not lysed. A low activity was displayed by head kidney and spleen cell populations whereas blood leukocytes revealed no significant activity. The effect of E:T ratio on cytotoxicity as well as microscopy observations suggested that the cytotoxic reaction required effector-target cell contact. Eosinophilic granule cells, isolated on a Percoll density gradient from a peritoneal wash, appeared to be responsible for the in vitro cytotoxic activity
Histamine and spontaneously released mast cell granules affect the cell growth of human hepatocellular carcinoma cells
Full text linkThe role of mast cells in tumor growth is still controversial. In this study we analyzed the effects of both histamine and pre-formed mediators spontaneously released by mast cells on the growth of two human hepatocellular carcinoma cell lines, HA22T/VGH and HuH-6, with different characteristics of differentiation, biological behavior and genetic defects. We showed that total mast cell releasate, exocytosed granules (granule remnants) and histamine reduced cell viability and proliferation in HuH-6 cells. In contrast, in HA22T/VGH cells granule remnants and histamine induced a weak but significant increase in cell growth. We showed that both cell lines expressed histamine receptors H1 and H2 and that the selective H1 antagonist terfenadine reverted the histamine-induced inhibition of HuH-6 cell growth, whereas the selective H2 antagonist ranitidine inhibited the histamine-induced cell growth of HA22T/VGH cells. We demonstrated that histamine down-regulated the expression of β-catenin, COX-2 and survivin in HuH-6 cells and that this was associated with caspase-3 activation and PARP cleavage. On the contrary, in HA22T/VGH cells expression of survivin and β-catenin increased after treatment with granule remnants and histamine. Overall, our results suggest that mediators stored in mast cell granules and histamine may affect the growth of liver cancer cells. However, mast cells and histamine may play different roles depending on the tumor cell features. Finally, these data suggest that histamine and histamine receptor agonists/antagonists might be considered as "new therapeutic" drugs to inhibit liver tumor growth
Non invasive tools for the diagnosis of liver cirrhosis
Full text linkLiver cirrhosis (LC), the end stage of many forms of chronic hepatitis of different etiologies is a diffuse
process characterized by fibrosis and the conversion of normal liver architecture into structurally abnormal nodules surrounded by annular fibrosis. This chronic
progressive clinical condition, leads to liver cell failure and portal hypertension, which can favour the onset of hepatocellular carcinoma. Defining the phase of the natural history is crucial for therapeutic choice and prognosis. Liver biopsy is currently considered the
best available standard of reference but it has some limits, so alternative tools have been developed to substitute liver biopsy when assessing liver fibrosis.
Serum markers offer a cost-effective alternative to liver biopsy being less invasive and theoretically without
complications. They can be classified into direct and indirect markers which may be used alone or in combination to produce composite scores. Diagnostic
imaging includes a number of instruments and techniques to estimate liver fibrosis and cirrhosis like
ultrasound (US), US Doppler, contrast enhanced US and Elastography. US could be used for the diagnosis of
advanced LC while is not able to evaluate progression of fibrosis, in this case Elastography is more reliable.
This review aims to revise the most recent data from the literature about non invasive methods useful in
defining liver fibrosis
Lipid nanocarrier for the treatment of hepatocellular carcinoma
No full textHepatocellular carcinoma (HCC) is the sixth most prevalent cancer and the third most frequent cause of cancer-related death. Unlike most solid tumors the incidence and mortality of HCC have increased in the United States and Europe in the past decade. Most patients are diagnosed at advanced stages, so there is an urgent need for new systemic therapies [1,2].
To improve the delivery of therapeutic agents to tumor cells in vivo it’s necessary to overcome several problems, such as drug resistance at the tumor level due to physiological barriers (non cellular based mechanism), drug resistance at the cellular level (cellular mechanism), drug distribution, biotransformation and clearance of anticancer drugs in the body. At the purpose to increase selectivity of drugs towards cancer cells while reducing their toxicity towards normal tissues, a promising strategy could be to entrap antitumor drugs into colloidal nanoparticles. Nanosystems may act as drug vehicles able to target tumor tissues or cells, protecting it from premature inactivation during its transport. At the tumor level the accumulation mechanism of intravenously injected nanoparticles relies on a passive diffusion or convection across the leaky hyperpermeable tumor vasculature [3-5].
For the treatment of HCC several drugs are under development, but the only one with proven survival benefit is sorafenib. This agent is a multikinase inhibitor that blocks Raf signaling and VEGF, PDGF and c-Kit. It has antiproliferative and antiangiogenic activity and delays tumor progression [1,2].
In order to produce a new colloidal system able to deliver this drug in the tumor tissue and decrease its side effects, nanostructured lipid carriers (NLCs) were developed using tripalmitin, Miglyol 812 and sorafenib. The obtained nanosystems were characterized in terms of size, polidispersity index, zeta potential and morphology using Scanning Electron Microscopy. Moreover, technological-pharmaceutical characterization of NLC was made. Stability studies showed that the systems were stable up to 60 days, while particle aggregation occurred after a period of storage of 90 days. Afterwards, for this reason, the same systems were prepared with the addition of two cryoprotectors (threalose and glycerol) before freezing and lyophilization. Finally, in vitro biological studies were carried out by MTS assays using human hepatocellular carcinoma HepG2, Hep3B, Huh7 and PLC/PRF/5 cells. Results obtained demonstrate an improved efficacy of sorafenib-loaded NLC compared to the free drug in Huh7 cells, whereas in HepG2 and PLC/PRF/5 cells sorafenib-loaded NLCs maintain an antitumor activity comparable to free drug.
Considering that solid tumours present much more favourable conditions for preferential accumulation of colloidal sized drug delivery systems, sorafenib-loaded NLC can be useful for application in liver cancer therapy.
[1] A. Forner, J.M. Llovet and J. Bruix, Lancet, 379, 1245 (2012).
[2] M. Cervello, J.A. McCubrey, A. Cusimano, N. Lampiasi, A. Azzolina and G. Montalto, Oncotarget, 3, 236 (2012).
[3] I. Brigger, C. Dubernet and P. Couvreur, Adv. Drug Del. Rev., 54, 631 (2002).
[4] M.L. Bondì, A. Azzolina, E.F. Craparo, G. Capuano, N. Lampiasi , G. Giammona and M. Cervello, Curr. Nanoscience, 5, 39 (2009).
[5] M.L. Bondì, E.F. Craparo, G. Giammona, M. Cervello, A. Azzolina, P. Diana, A. Martorana and G. Cirrincione, Drug Deliv., 14, 61 (2007)
Properties of sea urchin coelomocyte agglutinins
No full textWe examined some biological activities of a 200-kDa glycoprotein, referred to as Paracentrotus lividus vitellogenin, contained both in the coelomic fluid and in a subpopulation of coelomocytes called «colourless spherula cells». Cell-free coelomic fluid, coelomocyte lysate and supernatant obtained after coelomocyte washings were assayed for hemagglutinating activity. All samples agglutinated rabbit erythrocytes in a calcium-dependent way. The comparison between the electrophoretic patterns of erythrocyte lysates, before and after incubation with the coelomic fluid, revealed that a 200-kDa band was obtained from membranes of agglutinated erythrocytes. In addition, polyclonal antibodies against 200-kDa glycoprotein from sea urchin embryos used in Western blot analysis recognized the 200-kDa glycoprotein only when erythrocyte lysates previously incubated with coelomic fluids were assayed. These results suggest that the 200-kDa glycoprotein could be an agglutinin, present in the coelomic fluid and released by coelomocytes during stress conditions
PIVKAII Utility in Diagnosis and Post-therapeutic Monitoring of Hepatocellular Carcinoma
No full textBackground: Protein induced by vitamin K absence (PIVKA-II), also known as des-gamma-carboxyprothrombin, has been described in relation to HCC being released in association with vitamin K deficiency in the presence of HCC. Serum alpha-fetoprotein (AFP) is the traditional biomarker for HCC detection and follow up but it doesn’t have high sensitivity and specificity. Therefore, there is great interest in identifying new more powerful biomarkers.
Materials and methods: One hundred and fourteen subjects were divided into four groups: Group 1 included 58 patients (38M, 20 F) with HCC, mean age 73.5; Group 2 included 38 patients (28M, 10F) with liver cirrhosis (LC), mean age 63.7; Group 3 included 28 control healthy subjects (25M, 3F), mean age 54.7 and Group 4 included 16 HCC patients (8M, 8F) who underwent to TACE as therapy for HCC. PIVKA II levels were dosed in an overnight fasting blood sample with commercially available chemiluminescent assay (Architect 1000i System, Abbott, USA). Statistical analysis: data were expressed as mean ± SD when distribution was normal, otherwise as median (min-max). Student’s t, Mann Whitney U, Chi-square tests and Pearson linear regression analysis were used when appropriate.
Results: PIVKA II levels were higher in HCC group (82.3 mAU/ml) with respect to LC (31.5 mAU/ml) and healthy control (19.7 mAU/ml ) groups and in particular HCC vs controls (p<0.0001), LC vs controls (p<0.0001), HCC vs LC (p<0.005). Moreover, if using a cut off value of 50.9 mAU/ml none in the control group had PIVKA II levels above the cut off, while about 30% of LC and more than 50% of HCC patients had PIVKA II values higher than the cut off. PIVKA II levels in HCC patients who underwent to TACE treatment were higher after the treatment than at baseline. In particular at baseline 31% of HCC patients had PIVKA II levels higher than cut off, while after TACE they became 75% and this behaviour was observed in particular in non responders patients.
Conclusions: Our results confirm data from the literature that hypothesize a role for PIVKA II as a better marker than the traditionally used however its role in monitoring the response to therapies needs further evaluations on larger sample
Antitumor activity of the novel small molecule Akt inhibitor SC66 in hepatocellular carcinoma cells.
No full textHepatocellular carcinoma (HCC) is the fifth most common cancer worldwide characterized by poor and often limited or no response to current drug therapies. The PI3K/Akt/mTOR pathway is a key regulator of cell proliferation and survival. Alterations in this pathway have been reported in many types of human cancer, including HCC. It has become evident that Akt inhibitors have great potential in cancer treatment. SC66 is a new allosteric Akt inhibitor that facilitates ubiquitination of Akt, favoring its degradation via the proteasome, thus inhibiting Akt signaling. In the present study, we investigated the anticancer activity of SC66 in HCC cell lines (HepG2, Huh7, Hep3B, PLC/PRF/5 and HA22T/VGH). Treatment with SC66 reduced cell viability in a dose- and time-dependent manner and inhibited colony formation. At the same time, SC66 induced anoikis, as demonstrated by alterations of cytoskeleton organization and reduction of E-cadherin, -catenin and Snail expression. SC66 induced apoptosis was revealed by flow cytometry analysis, cleavage of PARP, and decreased expression of the anti-apoptotic proteins survivin and Bcl2. In addition, after treatment with SC66 a dose-dependent ROS production was demonstrated by H2DCFDA-based fluorescence staining. Co-treatment with the ROS scavenger NAC prevented the SC66-induced cell growth inhibition and anoikis. In conclusion, our data indicated that the Akt inhibitor SC66 had antitumor effects on HCC cells. This was mediated by ROS production and induction of anoikis-mediated cell death. All together, our results provide a rational basis for the clinical use of SC66 in the treatment of liver cancer
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