Histamine and spontaneously released mast cell granules affect the cell growth of human hepatocellular carcinoma cells
The 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 H(1) and …
Molecular mechanisms of sorafenib action in liver cancer cells.
Sorafenib, a multikinase inhibitor, recently received FDA approval for the treatment of advanced hepatocellular carcinoma (HCC). However, as the clinical application of sorafenib evolves, there is increasing interest in defining the mechanisms underlying its anti-tumor activity. Considering that this specific inhibitor could target unexpected molecules depending on the biologic context, a precise understanding of its mechanism of action could be critical to maximize its treatment efficacy, while minimizing adverse effects. Two human HCC cell lines (HepG2 and Huh7), carrying different biological and genetic characteristics, were used in this study to examine the intracellular events leading …
Toxic mineral elements in Mytilus galloprovincialis from Sicilian coasts (Southern Italy)
We assessed the relationship between V, Cr, Mn, Hg, As, Cd, Sn, Sb and Pb concentrations in Mytilus galloprovincialis samples from the coasts of Sicily and the expression of metallothioneins. Toxic mineral elements assessment was carried out by A.A. Spectrometry and ICP-MS. The metallothioneins expression was performed by q-PCR method. Low metals' levels were found in the mussel samples examined, in comparison with what was reported in literature. The highest mean values of toxic mineral elements were found in Gela (Cr 0.178 +/- 0.03 mg/Kg, Mn 4.325 +/- 0.012 mg/Kg, As 3.706 +/- 0.009 mg/Kg, Sn 0.148 +/- 0.014 mg/Kg, Sb 0.009 +/- 0.004 mg/Kg e Pb 0.364 +/- 0.01 mg/Kg). Significant levels of…
Expression of WISPs and of their novel alternative variants in human hepatocellular carcinoma cells
WISPs (Wnt-induced secreted proteins) are members of the CCN (CTGF/Cyr61/Nov) family involved in fibrotic disorders and tumorigenesis. They have a typical structure composed of four conserved cysteine-rich modular domains, but variants of CCN members lacking one or more modules, generated by alternative splicing or gene mutations, have been described in various pathological conditions. WISP genes were first described as downstream targets of the Wnt signaling pathway, which is frequently altered in human hepatocellular carcinoma (HCC). In the present study, WISP mRNA expression was analyzed by RT-PCR in four human HCC cell lines (HepG2, HuH-6, HuH-7, HA22T/VGH). Our results show for the fir…
Prostaglandin E2 receptors and COX enxymes in human hepatocellular carcinoma: role in the regulation of cell growth
The aim of this study was to investigate the expression of prostaglandin E 2 receptors (EP 1-4 ), cyclooxygenase-1 (COX-1), and COX-2 in nontumor and tumor human liver tissues, and also to evaluate the antitumor activity of selective EP 1 receptor antagonist used alone or in combination with COX-1 and COX-2 selective inhibitors. Semiquantitative PCR analyses revealed that EP 1-4 , COX-1, and COX-2 mRNA expression was detected in nearly all the tissue samples assayed, although with a high variability between nontumor and tumor tissues. In vitro EP 1 receptor antagonist inhibited anchorage-independent cell growth and reduced the viability of hepatocellular carcinoma (HCC) cells in a dose-depe…
Targeted therapy for hepatocellular carcinoma: novel agents on the horizon.
Hepatocellular carcinoma (HCC) is the most common liver cancer, accounting for 90% of primary liver cancers. In the last decade it has become one of the most frequently occurring tumors worldwide and is also considered to be the most lethal of the cancer systems, accounting for approximately one third of all malignancies. Although the clinical diagnosis and management of early-stage HCC has improved significantly, HCC prognosis is still extremely poor. Furthermore, advanced HCC is a highly aggressive tumor with a poor or no response to common therapies. Therefore, new effective and well-tolerated therapy strategies are urgently needed. Targeted therapies have entered the field of anti-neopl…
The novel NF-κB inhibitor DHMEQ synergizes with celecoxib to exert antitumor effects on human liver cancer cells by a ROS-dependent mechanism
In a previous work of ours dehydroxymethyl-epoxyquinomicin (DHMEQ), an inhibitor of NF-κB, was shown to induce apoptosis through Reactive Oxygen Species (ROS) production in hepatoma cells. The present study demonstrated that DHMEQ cooperates with Celecoxib (CLX) to decrease NF-κB DNA binding and to inhibit cell growth and proliferation more effectively than treatment with these single agents alone in the hepatoma cell lines HA22T/VGH and Huh-6. ROS production induced by the DHMEQ-CLX combination in turn generated the expression of genes involved in endoplasmic reticulum (ER) stress and silencing TRB3 mRNA significantly decreased DHMEQ-CLX-induced cell growth inhibition. Moreover, the DHMEQ-…
Corrigendum to "poly (ADP-ribose) polymerase inhibition synergizes with the NF-κB inhibitor DHMEQ to kill hepatocellular carcinoma cells" [Biochim. Biophys. Acta 1853(12)(2015) 3224-3234].
Fig. 1. The effects of the DHMEQ–Olaparib combination on HCC cells. (A) Cells were treated for 72 hwith the indicated concentrations of DHMEQ–Olaparib and cell viability was assessed by MTS assays. The DHMEQ–Olaparib combination showed synergistic inhibition of cell viability in Hep3B cells and additive inhibition in Huh7 cells. Combination index (CI) values are indicated above the bar. Data are expressed as percent cell growth and are the mean ± SD of three separate experiments (each of which was performed in triplicate). *p b 0.05 and **p b 0.01 versus each agent alone. (B) Cells were treated for 24 h with DHMEQ (μg/ml) or Olaparib (μM) alone or in combination, allowed to grow for 14 days…
Antigens of <i>Euparipha pisana</i> (Snail)
The data obtained in this study suggest that eating <i>Euparipha pisana</i> (snail), a common food in Mediterranean countries, could give serious allergic reaction such as asthma. We describe here the identification and partial characterization of allergenic molecules form this new source. An aqueous extract of snail was obtained by homogenization in distilled water, centrifugation, dialysis and defatting with ethyl ether. Skin prick test (SPT) performed with the snail extract on 70 subjects allergic to the more common allergens of the Mediterranean area gave a SPT positivity in 61% of the subjects tested, with a mean value of histamine-equivalent prick (HEP) equal to 0.81 ± 0.2…
The selective cyclooxygenase-1 inhibitor SC-560 suppresses cell proliferation and induces apoptosis in human hepatocellular carcinoma cells
Two isoforms of cyclooxygenase (COX) are known, and to date most studies have implicated COX-2 in the development and progression of various human cancers. Increasing evidence suggests that COX-1 may also play a similar role. Indeed, we have recently observed that the dual COX-1/COX-2 inhibitor indomethacin induces apoptosis in human hepatocellular carcinoma (HCC) cell lines more effectively than the selective COX-2 inhibitors, possibly implicating COX-1 in HCC. In this study we investigated the expression of COX-1 in non-tumor and malignant human liver tissues, as well as the effects of the highly selective COX-1 inhibitor SC-560 on cell growth and apoptosis in human HCC cell lines. Expres…
Solid Lipid Nanoparticles Containing Nimesulide: Preparation, Characterization and Cytotoxicity Studies
The prospect of improved cancer therapy using Solid Lipid Nanoparticles (SLNs) as drug delivery system is promising. Sev- eral obstacles frequently encountered with anticancer compounds, such as poor drug solubility, are overcome by delivering them using SLN. Moreover, the intravenous administration of drugs into SLNs can potentially enhance drug blood circulation time and improve drug per- formance by inducing accumulation into tumours by enhanced permeability and retention (EPR) effect. This paper deals with the devel- opment of SLN containing nimesulide, a non-steroidal anti-inflammatory drug with antitumour effect and low solubility in water. Here, SLNs carrying nimesulide were prepared…
Poly (ADP-ribose) polymerase inhibition synergizes with the NF-κB inhibitor DHMEQ to kill hepatocellular carcinoma cells
Poly (ADP-ribose) polymerase (PARP) enzymes play a key role in the cellular machinery responsible for DNA repair. Dehydroxymethylepoxyquinomicin (DHMEQ), a new inhibitor of NF-κB, induces oxidative stress and DNA damage. The effects of DHMEQ in combination with Olaparib (PARP inhibitor) were studied on hepatocellular carcinoma (HCC) cells. The DHMEQ-Olaparib combination synergistically inhibited cell viability, cell proliferation and colony formation of Hep3B, but had additive effects on Huh7 cells. The synergistic effects of the combination correlated with increased apoptosis, caspase 3/7 activity and PARP cleavage. There was an induction of an endoplasmic reticulum (ER) stress response wi…
Novel Combination of Sorafenib and Celecoxib Provides Synergistic Anti-Proliferative and Pro-Apoptotic Effects in Human Liver Cancer Cells
Molecular targeted therapy has shown promise as a treatment for advanced hepatocellular carcinoma (HCC). Sorafenib, a multikinase inhibitor, recently received FDA approval for the treatment of advanced HCC. However, although sorafenib is well tolerated, concern for its safety has been expressed. Celecoxib (Celebrex®) is a selective cyclooxygenase-2 (COX-2) inhibitor which exhibits antitumor effects in human HCC cells. The present study examined the interaction between celecoxib and sorafenib in two human liver tumor cell lines HepG2 and Huh7. Our data showed that each inhibitor alone reduced cell growth and the combination of celecoxib with sorafenib synergistically inhibited cell growth an…
COX-2-dependent and COX-2-independent mode of action of celecoxib in human liver cancer cells.
Celecoxib (Celebrex((R)), Pfizer) is a selective cyclooxygenase-2 (COX-2) inhibitor with chemopreventive and antitumor effects. However, it is now well known that celecoxib has several COX-2-independent activities. To better understand COX-2-independent molecular mechanisms underlying the antitumor activity of celecoxib, we investigated the expression profile of the celecoxib-treated COX-2-positive (Huh7) and COX-2-negative (HepG2) liver cancer cell lines, using microarray analysis. Celecoxib treatment resulted in significantly altered expression levels of 240 and 403 transcripts in Huh7 and HepG2 cells, respectively. Confirmation of the microarray results was performed for selected genes b…
Novel cationic solid-lipid nanoparticles as non-viral vectors for gene delivery.
In this paper, the suitability of novel cationic solid-lipid nanoparticles (SLN) as a nonviral transfection agent for gene delivery was investigated. SLN were produced by using the microemulsion method and Compritol ATO 888 as matrix lipid, dimethyldioctadecylammonium bromide as charge carrier and Pluronic F68 as surfactant. Obtained nanoparticles were approximately 120 nm in size and positively charged, with a zeta potential value equal to +45 mV in twice-distilled water. Cationic SLN were able to form stable complexes with DNA and to protect DNA against DNase I digestion. The SLN-DNA complexes were characterized by mean diameter and zeta potential measurements. In vitro studies on human l…
Potentiation of the antitumor effects of both selective cyclooxygenase-1 and cyclooxygenase-2 inhibitors in human hepatic cancer cells by inhibition of the MEK/ERK pathway.
The molecular mechanisms behind the anti-neoplastic effects of non-steroidal anti-inflammatory drugs (NSAIDs) are not completely understood and cannot be explained by the inhibition of the cyclooxygenase (COX) enzymes COX-1 and COX-2 alone. We previously reported that both the selective COX-1 inhibitor SC-560 and the selective COX-2 inhibitor CAY10404 exhibit anti-tumor effects in human hepatoma cells. NSAID inhibitors have many COX-independent actions and, among others, the mitogen-activated protein kinase (MAPK) pathways are targets for NSAIDs. Here, we examined the role of MEK/ERK1/2 signaling in the anti-neoplastic effects of both selective COX-1 and COX-2 inhibitors in two human hepato…
Antitumor effects of dehydroxymethylepoxyquinomicin, a novel nuclear factor-kappaB inhibitor, in human liver cancer cells are mediated through a reactive oxygen species-dependent mechanism.
Activation of the nuclear transcription factor-kappa B (NF-kappa B) has been implicated in liver tumorigenesis. We evaluated the effects of a novel NF-kappa B inhibitor, dehydroxymethylepoxyquinomicin (DHMEQ), in two human liver cancer cell lines HA22T/VGH and HuH-6. DHMEQ treatment dose dependently decreased the DNA-binding capacity of the NF-kappa B p65 subunit, inhibited cell growth and proliferation, and increased apoptosis as shown by caspase activation, release of cytochrome c, poly(ADP-ribose) polymerase cleavage, and down-regulation of survivin. DHMEQ also induced a dose-dependent activation of mitogen-activated protein kinase kinase/extracellular signal-regulated kinase signaling, …