Redox Mechanisms Underlying the Cytostatic Effects of Boric Acid on Cancer Cells-An Issue Still Open.

Boric acid (BA) is the dominant form of boron in plasma, playing a role in different physiological mechanisms such as cell replication. Toxic effects have been reported, both for high doses of boron and its deficiency. Contrasting results were, however, reported about the cytotoxicity of pharmacological BA concentrations on cancer cells. The aim of this review is to briefly summarize the main findings in the field ranging from the proposed mechanisms of BA uptake and actions to its effects on cancer cells.

Antineoplastic Activity of Pazopanib in Anaplastic Thyroid Cancer in Primary Culture.

Anaplastic thyroid cancer (ATC) is a rare and rapidly fatal human cancer. Its usual treatment includes the combination of surgery, external hyperfractionated radiation therapy, and chemotherapy. These treatments permit achieving about 6-10 months of median survival. For this reason, it is challenging to predict the ATC patient clinical therapy responsiveness. Pazopanib is a multitarget tyrosine kinase inhibitor of VEGF receptors, PDGF, and c-Kit. Until now, the effect of pazopanib in primary human ATC cells (pATC) has not been reported in the literature. The aim of our study was to evaluate in vitro the antineoplastic effect of pazopanib in pATC. Surgical thyroidal tissues were collected from five patients with ATC, from thyroid biopsy at the moment of first surgical operation. An inhibition of proliferation, migration, and invasion, and an increase in apoptosis were demonstrated upon treating pATC cells with pazopanib (p < 0.05). Moreover, pazopanib was able to significantly decrease the VEGF expression in pATC cells (p < 0.05). To conclude, in this study, we demonstrate the antineoplastic activity of the antiangiogenic inhibitor, pazopanib, in human pATC in vitro.

Enhancement of ferroptosis by boric acid and its potential use as chemosensitizer in anticancer chemotherapy.

Ferroptosis is a form of regulated cell death (RCD) characterized by intracellular iron ion accumulation and reactive oxygen species (ROS)-induced lipid peroxidation. Ferroptosis in cancer and ferroptosis-related anticancer drugs have recently gained interest in the field of cancer treatment. Boron is an essential trace element playing an important role in several biological processes. Recent studies have described contrasting effects of boric acid (BA) in cancer cells, ranging from protective/mitogenic to damaging/antiproliferative. Interestingly, boron has been shown to interfere with critical factors involved in ferroptosis-intracellular glutathione and lipid peroxidation in the first place. Thus, the present study was aimed to verify the ability of boron to modulate the ferroptotic process in HepG2 cells, a model of hepatocellular carcinoma. Our results indicate that-when used at high, pharmacological concentrations-BA can increase intracellular ROS, glutathione, and TBARS levels, and enhance ferroptosis induced by RSL3 and erastin. Also, high BA concentrations can directly induce ferroptosis, and such BA-induced ferroptosis can add to the cytotoxic effects of anticancer drugs sorafenib, doxorubicin and cisplatin. These observations suggest that BA could be exploited as a chemo-sensitizer agent in order to overcome cancer drug resistance in selected conditions. However, the possibility of reaching suitably high concentrations of BA in the tumor microenvironment will need to be further investigated.

Anti-glutathione S-transferase omega 1-1 (GSTO1-1) antibodies are increased during acute and chronic inflammation in humans.

Glutathione S-transferase omega-1 (GSTO1-1) is a cytosolic enzyme involved in the modulation of critical inflammatory pathways as well as in cancer progression. Auto-antibodies against GSTO1-1 were detected in the serum of patients with esophageal squamous cell carcinoma and were proposed as potential biomarkers in the early detection of the disease. Our findings show that anti-GSTO1-1 antibodies can be found in a variety of inflammatory diseases, including autoimmune rheumatoid arthritis, infectious SARS-CoV-2, and trichinellosis. Our findings strongly suggest that anti-GSTO1-1 antibodies may be a marker of tissue damage/inflammation rather than a specific tumor-associated biomarker.

Airways glutathione S-transferase omega-1 and its A140D polymorphism are associated with severity of inflammation and respiratory dysfunction in cystic fibrosis.

BACKGROUND: Glutathione S-transferase omega-1 (GSTO1-1) is a cytosolic enzyme that modulates the S-thiolation status of intracellular factors involved in cancer cell survival or in the inflammatory response. Studies focusing on chronic obstructive pulmonary disease (COPD) have demonstrated that GSTO1-1 is detectable in alveolar macrophages, airway epithelium and in the extracellular compartment, where its functions have not been completely understood. Moreover GSTO1-1 polymorphisms have been associated with an increased risk to develop COPD. Against this background, the aim of this study was to evaluate GSTO1-1 levels and its polymorphisms in cystic fibrosis (CF) patients. METHODS: Clinical samples from a previous study published by our groups were analyzed for GSTO1-1 levels and polymorphisms. For comparison, a model of lung inflammation in CFTR-knock out mice was also used. RESULTS: Our data document that soluble GSTO1-1 can be found in the airways of CF patients and correlates with inflammatory parameters such as neutrophilic elastase and the chemokine IL-8. A negative correlation was found between GSTO1-1 levels and the spirometric parameter FEV1 and the FEV1/FVC ratio. Additionally, the A140D polymorphism of GSTO1-1 was associated with lower levels of the antiinflammatory mediators PGE2 and 15(S)-HETE, and with lower values of the FEV1/FVC ratio in CF subjects with the homozygous CFTR ΔF508 mutation. CONCLUSIONS: Our data suggest that extracellular GSTO1-1 and its polymorphysms could have a biological and clinical significance in CF. Pathophysiological functions of GSTOs are far from being completely understood, and more studies are required to understand the role(s) of extracellular GSTO1-1 in inflamed tissues.

Assessing the cytotoxic/genotoxic activity and estrogenic/antiestrogenic potential of essential oils from seven aromatic plants.

Alternative therapies with new drugs are needed because the clinical efficacy of conventional chemotherapy is often reduced due to collateral effects. Many natural products of plant origin, including essential oils (EOs) have proved to be effective in prevention and therapy of several diseases such as bacterial infections, chronic diseases and cancer. In the present study, we investigated some biological activities of EOs extracted from seven plants: Rosmarinus officinalis, Salvia somalensis, Thymus vulgaris, Achillea millefolium, Helichrysum italicum, Pistacia lentiscus, Myrtus communis. In particular, we evaluated the cytotoxic and genotoxic activity using the cytochalasin B-blocked micronucleus assay (CBMN) in human peripheral lymphocytes, cytotoxicity in a human ovarian carcinoma cell line (A2780), and the estrogenic/antiestrogenic activity using a yeast strain expressing the human estrogen receptor alpha (ERα). Our results show that most EOs can have a strong cytotoxic and a slight/moderate genotoxic effect on human peripheral lymphocytes, and also a pronounced cytotoxic effect in A2780 cells. In addition, some EOs seem to have a marked antiestrogenic activity that could potentially perturb the estrogen-dependent tissues.

Induction of Gamma-Glutamyltransferase Activity and Consequent Pro-oxidant Reactions in Human Macrophages Exposed to Crocidolite Asbestos.

Asbestos is the main causative agent of malignant pleural mesothelioma. The variety known as crocidolite (blue asbestos) owns the highest pathogenic potential, due to the dimensions of its fibers as well as to its content of iron. The latter can in fact react with macrophage-derived hydrogen peroxide in the so called Fenton reaction, giving rise to highly reactive and mutagenic hydroxyl radical. On the other hand, hydroxyl radical can as well originate after thiol-dependent reduction of iron, a process capable of starting its redox cycling. Previous studies showed that glutathione (GSH) is one such thiol, and that cellular gamma-glutamyltransferase (GGT) can efficiently potentiate GSH-dependent iron redox cycling and consequent oxidative stress. As GGT is expressed in macrophages and is released upon their activation, the present study was aimed at verifying the hypothesis that GSH/GGT-dependent redox reactions may participate in the oxidative stress following the activation of macrophages induced by crocidolite asbestos. Experiments in acellular systems confirmed that GGT-mediated metabolism of GSH can potentiate crocidolite-dependent production of superoxide anion, through the production of highly reactive dipeptide thiol cysteinyl-glycine. Cultured THP-1 macrophagic cells, as well as isolated monocytes obtained from healthy donors and differentiated to macrophages in vitro, were investigated as to their expression of GGT and the effects of exposure to crocidolite. The results show that crocidolite asbestos at subtoxic concentrations (50-250 ng/1000 cells) can upregulate GGT expression, which raises the possibility that macrophage-initiated, GSH/GGT-dependent pro-oxidant reactions may participate in the pathogenesis of tissue damage and inflammation consequent to crocidolite intoxication.

γ-Glutamyltransferase enzyme activity of cancer cells modulates L-γ-glutamyl-p-nitroanilide (GPNA) cytotoxicity.

L-γ-Glutamyl-p-nitroanilide (GPNA) is widely used to inhibit the glutamine (Gln) transporter ASCT2, but recent studies have demonstrated that it is also able to inhibit other sodium-dependent and independent amino acid transporters. Moreover, GPNA is a well known substrate of the enzyme γ-glutamyltransferase (GGT). Our aim was to evaluate the effect of GGT-mediated GPNA catabolism on cell viability and Gln transport. The GGT-catalyzed hydrolysis of GPNA produced cytotoxic effects in lung cancer A549 cells, resulting from the release of metabolite p-nitroaniline (PNA) rather than from the inhibition of Gln uptake. Interestingly, compounds like valproic acid, verapamil and reversan were able to increase the cytotoxicity of GPNA and PNA, suggesting a key role of intracellular detoxification mechanisms. Our data indicate that the mechanism of action of GPNA is more complex than believed, and further confirm the poor specificity of GPNA as an inhibitor of Gln transport. Different factors may modulate the final effects of GPNA, ranging from GGT and ASCT2 expression to intracellular defenses against xenobiotics. Thus, other strategies - such as a genetic suppression of ASCT2 or the identification of new specific inhibitors - should be preferred when inhibition of ASCT2 function is required.

Lenvatinib exhibits antineoplastic activity in anaplastic thyroid cancer in vitro and in vivo.

Lenvatinib is an oral, multitargeted tyrosine kinase inhibitor (TKI) of VEGFR1-VEGFR3, FGFR1-FGFR4, PDGFRα, RET and v-kit Hardy-Zuckerman 4 feline sarcoma viral oncogene homolog (KIT) signaling networks involved in tumor angiogenesis. We have evaluated the antitumor activity of lenvatinib in primary anaplastic thyroid cancer (ATC) cells, in the human cell line 8305C (undifferentiated thyroid cancer) and in an ATC-cell line (AF). The AF cell line was obtained from the primary ATC cultures and was the one that grew over 50 passages. The effect of lenvatinib (1 and 100 nM; and 1, 10, 25 and 50 µM) was investigated in primary ATC, 8305C and AF cells as well as in AF cells in CD nu/nu mice. Lenvatinib significantly reduced ATC cell proliferation (P<0.01, ANOVA) and increased the percentage of apoptotic ATC cells (P<0.001, ANOVA). Furthermore, lenvatinib inhibited migration (P<0.01) and invasion (P<0.001) in ATC. In addition, lenvatinib inhibited EGFR, AKT and ERK1/2 phosphorylation and downregulated cyclin D1 in the ATC cells. Lenvatinib also significantly inhibited 8305C and AF cell proliferation, increasing apoptosis. AF cells were subcutaneously injected into CD nu/nu mice and tumor masses were observed 20 days later. Tumor growth was significantly inhibited by lenvatinib (25 mg/kg/day), as well as the expression of VEGF-A and microvessel density in the AF tumor tissues. In conclusion, the antitumor and antiangiogenic activities of lenvatinib may be promising for the treatment of anaplastic thyroid cancer, and may consist a basis for future clinical therapeutic applications.

Vandetanib has antineoplastic activity in anaplastic thyroid cancer, in vitro and in vivo.

The antitumor activity of vandetanib [a multiple signal transduction inhibitor including the RET tyrosine kinase, epidermal growth factor receptor (EGFR), vascular endothelial growth factor (VEGF) receptor (VEGFR), ERK and with antiangiogenic activity], in primary anaplastic thyroid cancer (ATC) cells, in the human cell line 8305C [undifferentiated thyroid cancer (TC)] and in an ATC­cell line (AF), was investigated in the present study. Vandetanib (1 and 100 nM; 1, 10, 25 and 50 µM) was tested by WST­1, apoptosis, migration and invasion assays: in primary ATC cells, in the 8305C continuous cell line, and in AF cells; and in 8305C cells in CD nu/nu mice. Vandetanib significantly reduced ATC cell proliferation (P<0.01, ANOVA), induced apoptosis dose­dependently (P<0.001, ANOVA), and inhibited migration (P<0.01) and invasion (P<0.001). Furthermore, vandetanib inhibited EGFR, AKT and ERK1/2 phosphorylation and downregulated cyclin D1 in ATC cells. In 8305C and AF cells, vandetanib significantly inhibited the proliferation, inducing also apoptosis. 8305C cells were injected subcutaneously in CD nu/nu mice and tumor masses became detectable after 30 days. Vandetanib (25 mg/kg/day) significantly inhibited tumor growth and VEGF­A expression and microvessel density in 8305C tumor tissues. In conclusion, the antitumor and antiangiogenic activity of vandetanib is very auspicious in ATC, opening the way to a future clinical evaluation.

The paramount role of cytokines and chemokines in papillary thyroid cancer: a review and experimental results.

Our study demonstrates that (C-X-C motif) ligand 9 and 11 (CXCL9, CXCL11) chemokines were absent basally in non-neoplastic thyroid (TFC) and papillary thyroid carcinoma (PTC) cells. Interferon (IFN)γ induced the chemokine secretion in TFC and PTC, while tumor necrosis factor (TNF)α induced it only in PTC. IFNγ+TNFα induced a synergistic chemokines release in PTC, and at a lower level in TFC. Peroxisome proliferator-activated receptor (PPAR)γ agonists suppressed dose-dependently IFNγ+TNFα-induced chemokine release in TFC, while stimulated it in PTC. PPARγ knocking down, by RNA interference technique in PTC cells, abolished the effect of PPARγ agonists on chemokines release. In PTC cells, PPARγ agonists reduced proliferation, and CXCL9 or CXCL11 (100 and 500 pg/mL) reduced proliferation and migration (P < 0.01, for all). In conclusion, in PTC cells: (a) IFNγ+TNFα induced a marked release of CXCL9 and CXCL11; (b) PPARγ agonists stimulated CXCL9 and CXCL11 secretion, while inhibited proliferation; (c) CXCL9 and CXCL11 inhibited proliferation and migration. The use of CXCL9 or CXCL11 as antineoplastic agents in PTC remains to be explored. HIGHLIGHTS: • IFNγ and IFNγ+TNFα induce dose-dependently CXCL9 (and less CXCL11) in PTC cells. • Rosi and Pio dose-dependently inhibit the PTC cells proliferation. • Rosi and Pio (at variance of normal TFC) stimulate CXCL9 or CXCL11 secretion. • CXCL9 or CXCL11 induce a significant antiproliferative effect in PTC cells. • Chemokines induced by IFNγ (CXCL9 or CXCL11) inhibit migration in PTC cells.

Antineoplastic Effect of Lenvatinib and Vandetanib in Primary Anaplastic Thyroid Cancer Cells Obtained From Biopsy or Fine Needle Aspiration.

Anaplastic thyroid carcinoma (ATC) is a malignant tumor of the thyroid gland, infrequent but with a very poor prognosis, as it rapidly causes death (mean survival of about 6 months). ATC treatment includes a multimodal protocol consisting of surgery, chemotherapy (doxorubicin and cisplatin), and hyperfractionated accelerated external beam radiotherapy (median patient survival of 10 months). For this reason, the identification of an effective systemic treatment for ATC would be a major advance in the management of this deadly thyroid cancer. The opportunity to test the sensitivity to different drugs of primary cells from ATC (pATC) cultures, obtained from each patients, could improve the effectiveness of the treatment. Then, the administration of inactive therapeutics could be avoided. Our aim is to investigate the antineoplastic effect of two tyrosine kinase inhibitors (TKIs; lenvatinib, vandetanib) in pATC obtained both from biopsy (biop-pATC), and from fine needle aspiration (FNA-pATC). The antiproliferative activity of lenvatinib and vandetanib was evaluated in 6 ATC patients, on biop-pATC, such as on FNA-pATC. A significant reduction of proliferation (obtained by WST-1 assay) vs. control was shown with lenvatinib and vandetanib in FNA-pATC, as well as in biop-pATC. The percentage of apoptosis in FNA-pATC, or biop-pATC, increased with both compounds dose-dependently. pATC cells from FNA, or biopsy, had a similar sensitivity to lenvatinib and vandetanib. In conclusion, primary cells (biop-pATC or FNA-pATC) have a similar sensitivity to TKIs, and lenvatinib and vandetanib are effective in reducing cell growth, increasing apoptosis in ATC. The possibility to test the sensitivity to different TKIs in each patient could open the way to personalized treatments, avoiding the administration of ineffective, and potentially dangerous, drugs.

CCL2 is Modulated by Cytokines and PPAR-γ in Anaplastic Thyroid Cancer.

BACKGROUND AND OBJECTIVE: Chemokine (C-C motif) ligand (CCL)2, the prototype Th2 chemokine, is secreted by tumor cells, and has growth promoting effects. Whether CCL2 protumorigenic activities will be validated, then CCL2 and its receptor CCR2 may be therapeutic targets in cancer. METHODS: We tested in "primary human anaplastic thyroid carcinoma (ATC) cells" (ANA) versus "normal thyroid follicular cells" (TFC): a) CCL2 secretion basally, after IFN-γ and/or TNF-α stimulation; b) PPARγ activation by thiazolidinediones (TZDs), rosiglitazone or pioglitazone, on CCL2 secretion, and on proliferation and apoptosis in ANA. RESULTS: ANA produced basally CCL2, at a higher level versus TFC. IFN-γ or TNF-α dose-dependently induced the CCL2 release in 3/6 or 5/6 ANA, respectively, but in all TFC. IFN-γ+TNF-α induced a synergistic release of CCL2 in all TFC, but only in 1/6 ATC. TZDs exerted an inhibition of CCL2 release in 3/6 ANA, while had no effect in TFC. Pioglitazone inhibition of ANA proliferation was not associated with the effect on CCL2; NF-κB and ERK1/2 were basally activated in ANA, increased by IFN-γ+TNF-α, and pioglitazone inhibited IFN- γ+TNF-α activation. CCL2 serum levels were higher in 6 ATC patients than in 5 controls (813±345 versus 345±212, pg/mL; respectively; P<0.01, ANOVA). CONCLUSION: ANA produce CCL2 basally and after cytokines stimulation, with an extremely variable pattern of modulation, suggesting different types of deregulation in the chemokine modulation. Serum CCL2 is increased in ATC patients. Further studies will be necessary to evaluate if CCL2 might be used as a marker in the followup of ATC patients.

Increased level of DNA damage in some organs of obese Zucker rats by γ-H2AX analysis.

In a recent study, we showed that lymphocytes of obese Italian children/adolescents displayed levels of double strand breaks (DSB), assayed as serine 139-phosphorylated histone H2AX (γ-H2AX), about eightfold higher than normal weight controls, and that 30% of this damage-generated micronuclei. These findings suggested that obese children could be at increased risk of obesity-mediated cancer later in life. We therefore aimed to assess the level of γ-H2AX in a genetic animal model of obesity (Zucker rat) to identify a genotoxic/carcinogenic risk in some organs. The DSB marker was studied in 3- to 4-week-old rats and in 9- to 13-week-old rats. Paraffin-embedded sections of heart, thyroid, liver, pancreas, lung, kidney, esophagus, and gut from the fa-/fa- (obese) and the fa+/fa- (lean) control animals were processed for immunohistochemistry detection of γ-H2AX. Pancreas (0.0624 ± 0.0195), lung (0.1197 ± 0.0217), esophagus (0.1230 ± 0.0351), kidney (0.1546 ± 0.0149), and gut (0.1724 ± 0.0352) of 9- to 13-week-old obese rats showed a higher proportion of γ-H2AX-positive nuclei, than their lean counterparts (0.0092 ± 0.0033, 0.0416 ± 0.0185, 0.0368 ± 0.0088, 0.0686 ± 0.0318, and 0.0703 ± 0.0239, respectively). No difference was seen in the 3- to 4-week-old age group with regard to obesity, indicating that the DNA damage increased with older age of the rats. We hypothesize that the organs of the obese animals showing high levels of DSB could represent target tissues for the development of obesity-related cancers. Environ. Mol. Mutagen. 58:477-484, 2017. © 2017 Wiley Periodicals, Inc.

Antineoplastic activity of the multitarget tyrosine kinase inhibitors CLM3 and CLM94 in medullary thyroid cancer in vitro.

BACKGROUND: We report the antineoplastic and anti-angiogenic activity of the pyrazolo[3,4-d]pyrimidine derivative CLM3 and the cyclic amide CLM94, both multiple tyrosine kinase inhibitors (TKIs), in human primary medullary thyroid cancer (P-MTC) cells, and in vitro in the medullary thyroid cancer (MTC) cell lines TT (harboring a RET C634W activating mutation) and MZ-CRC-1 (carrying the MEN2B RET mutation Met891Thr). METHODS: The antiproliferative and proapoptotic effects of CLM3 and CLM94 (1, 5, 10, 30, and 50 µmol/L) were tested in P-MTC cells obtained at operation, and in TT cells. In addition, the antiproliferative effects of CLM3 and CLM94 (0.005, 0.05, 0.5, and 5 µmol/L) were tested in TT and MZ-CRC-1 cells after 7 days of treatment to compare the results with those previously reported in the literature. RESULTS: CLM3 and CLM94 (30 or 50 µmol/L) inhibited (P < .01) the proliferation of the P-MTC cells, TT cells, and MZ-CRC-1 cells and increased the level of apoptosis in a dose-dependent manner at 10, 30, and 50 µmol/L (P < .001), while having no effect on migration or invasion. The inhibition of proliferation by CLM3 and CLM94 was similar among P-MTC cells with/without RET mutations, and similar effects were observed regarding the increased level of apoptosis. Furthermore, CLM3 and CLM94 significantly decreased vascular endothelial growth factor-A expression in TT cells. CONCLUSION: The antitumor activities of the multiple TKIs CLM3 and CLM94 were demonstrated in both primary MTC cultures as well as 2 established MTC cell lines in vitro, opening an avenue for future clinical evaluations.

CLM29, a multi-target pyrazolopyrimidine derivative, has anti-neoplastic activity in medullary thyroid cancer in vitro and in vivo.

CLM29 (a pyrazolo[3,4-d]pyrimidine, that inhibits RET, epidermal growth factor receptor, vascular endothelial growth factor receptor, and has an anti-angiogenic activity) has anti-neoplastic activity in papillary dedifferentiated thyroid cancer. Here we tested CLM29 in medullary thyroid cancer (MTC), in primary MTC cells (P-MTC) obtained at surgery, and in TT cells harboring (C634W) RET mutation. CLM29 (10, 30, 50 µM) inhibited significantly (P<0.001) the proliferation, and increased the percentage of apoptotic P-MTC, TT and human dermal microvascular endothelial cells. The inhibition of proliferation by CLM29 was similar in P-MTC cells with/without RET mutation. TT cells were injected sc in CD nu/nu mice, and tumor masses became detectable between 20 and 30 days after xenotransplantation; CLM29 (50mg/kg/die) reduced significantly tumor growth and weight, and microvessel density. The anti-tumor activity of CLM29 has been shown in MTC in vitro, and in vivo, opening the way to a future clinical evaluation.

CLM3, a multitarget tyrosine kinase inhibitor with antiangiogenic properties, is active against primary anaplastic thyroid cancer in vitro and in vivo.

CONTEXT AND OBJECTIVE: We have studied the antitumor activity of a pyrazolo[3,4-d]pyrimidine compound (CLM3) proposed for a multiple signal transduction inhibition [including the RET tyrosine kinase, epidermal growth factor receptor, and vascular endothelial growth factor (VEGF) receptor and with antiangiogenic activity] in primary anaplastic thyroid cancer (ATC) cells, in the human cell line 8305C (undifferentiated thyroid cancer), and in an ATC-cell line (AF). DESIGN AND MAIN OUTCOME MEASURES: CLM3 was tested in primary ATC cells at the concentrations of 5, 10, 30, and 50 µM; in 8305C cells, in AF cells, at 1, 5, 10, 30, 50, or 100 µM; and in AF cells in CD nu/nu mice. RESULTS: CLM3 significantly inhibited the proliferation of 8305C and AF cells, also inducing apoptosis. A significant reduction of proliferation with CLM3 in ATC cells (P < .01, ANOVA) was shown. CLM3 increased the percentage of apoptotic ATC cells dose dependently (P < .001, ANOVA) and inhibited migration (P < .01) and invasion (P < .001). The AF cell line was injected sc in CD nu/nu mice, and tumor masses became detectable 15 days later. CLM3 (50 mg/kg per die) significantly inhibited tumor growth (starting 16 d after the beginning of treatment). CLM3 significantly decreased the VEGF-A expression and microvessel density in AF tumor tissues. Furthermore, CLM3 inhibited epidermal growth factor receptor, AKT, and ERK1/2 phosphorylation and down-regulated cyclin D1 in 8305C and AF cells. CONCLUSIONS: The antitumor and antiangiogenic activity of a pyrazolo[3,4-d]pyrimidine compound (CLM3) is very promising in anaplastic thyroid cancer, opening the way to a future clinical evaluation.

High levels of γ-H2AX foci and cell membrane oxidation in adolescents with type 1 diabetes.

Oxidative stress caused by an excess of free radicals is implicated in the pathogenesis and development of type 1 diabetes mellitus (T1DM) and, in turn, it can lead to genome damage, especially in the form of DNA double-strand break (DSB). The DNA DSB is a potentially carcinogenic lesion for human cells. Thus, we aimed to evaluate whether the level of oxidative stress was increased in peripheral blood lymphocytes of a group of affected adolescents. In 35 T1DM adolescents and 19 healthy controls we assessed: (1) spontaneous and H2O2-induced oxidation of cell membrane using a fluorescence lipid probe; (2) spontaneous and LPS-induced expression of iNOS protein and indirect NO determination via cytofluorimetric analysis of O2(-); (3) immunofluorescent detection of the basal level of histone H2AX phosphorylation (γ-H2AX foci), a well-validated marker of DNA DSB. In T1DM, the frequencies of oxidized cells, both spontaneous and H2O2-induced (47.13±0.02) were significantly higher than in controls (35.90±0.03). Patients showed, in general, both a reduced iNOS expression and production of NO. Furthermore, the level of spontaneous nuclear damage, quantified as γ-H2AX foci, was markedly increased in T1DM adolescents (6.15±1.08% of γ-H2AX(+) cells; 8.72±2.14 γ-H2AXF/n; 9.26±2.37 γ-H2AXF/np), especially in females. In the present study, we confirmed the role that oxidative stress plays in the disease damaging lipids of cell membrane and, most importantly, causing genomic damage in circulating white blood cells of affected adolescents. This also indicates that oxidative stress can affect several tissues in the body. However, although the observed DNA damage is a clear indication that the proper DNA repair mechanisms are activated, the risk for young T1DM subjects of developing not only cardiovascular complications but also some type of cancer cannot be ruled out. In this view, females, probably due to hormonal imbalance typical of adolescence, might represent a more susceptible population.

γ-Glutamyltransferase catabolism of S-nitrosoglutathione modulates IL-8 expression in cystic fibrosis bronchial epithelial cells.

S-nitrosoglutathione (GSNO) is an endogenous nitrosothiol involved in several pathophysiological processes. A role for GSNO has been envisaged in the expression of inflammatory cytokines such as IL-8; however, conflicting results have been reported. γ-Glutamyltransferase (GGT) enzyme activity can hydrolyze the γ-glutamyl bond present in the GSNO molecule thus greatly accelerating the release of bioactive nitric oxide. Expression of GGT is induced by oxidative stress, and activated neutrophils contribute to GGT increase in cystic fibrosis (CF) lung exudates by releasing GGT-containing microvesicles. This study was aimed at evaluating the effect of GSNO catabolism mediated by GGT on production of IL-8 in CF transmembrane regulation protein-mutated IB3-1 bronchial cells. The rapid, GGT-catalyzed catabolism of GSNO caused a decrease in both basal and lipopolysaccharide-stimulated IL-8 production in IB3-1 cells, by modulating both NF-κB and ERK1/2 pathways, along with a decrease in cell proliferation. In contrast, a slow decomposition of GSNO produced a significant increase in both cell proliferation and expression of IL-8, the latter possibly through p38-mediated stabilization of IL-8 mRNA. Our data suggest that the differential GSNO catabolism mediated by GGT enzyme activity can downregulate the production of IL-8 in CF cells. Hence, the role of GGT activity should be considered when evaluating GSNO for both in vitro and in vivo studies, the more so in the case of GSNO-based therapies for cystic fibrosis.

Effects of spindle poisons in peripheral human lymphocytes by the in vitro cytokinesis-block micronucleus assay.

The search for micronuclei (MN) in binucleated cells is not always the best choice to recognize microtubule-perturbing agents, as they give rise to (micronucleated) mononucleated cells, mainly via mitotic slippage. We therefore treated peripheral lymphocytes with vincristine (VCR), nocodazole (NOC) and colcemid (COL): (i) to quantify the formation of MN in mononucleated cells and the occurrence of abnormal mitoses (c-anaphases, endoreduplicated or tetraploid metaphases); (ii) to investigate the role of cytokinesis inhibition in determining or modulating the cytogenetic effects induced by the spindle poisons (we used either cytochalasin B (cyt B) or latrunculin A, a cytokinesis inhibitor that acts differently as compared with cyt B); (iii) to assess the ploidy of cells bearing MN by fluorescence in situ hybridisation (FISH) analysis; and (iv) to evaluate the levels of the mitotic arrest deficient (MAD2) protein, that blocks the cell at the metaphase-anaphase transition, by immunoblotting. We observed the induction of numerous abnormal mitoses and tetraploid interphase nuclei, as well as of MN in mononucleated cells, a high percentage of which had a diploid complement. We also found that the effects were generally not dose but chemical dependent, where NOC was proven to be more effective than COL and VCR in inducing overall MN formation and, specifically, diploid micronucleated lymphocytes. Aneugens damaged cells to a greater extent in the presence of cytokinesis inhibitors rather than in their absence. MAD2 protein was expressed in controls to an extent reflecting the amount of lymphocytes which were initially in the G2/M transition phase. The same trend was seen in aneugen-treated cells where MAD2 levels decreased with increasing spindle poison concentration. Here, we demonstrate that micronucleated mononucleated cells and aberrant mitoses can be considered useful markers of exposure to aneugens-like spindle poisons causing preferentially, but not exclusively, mitotic slippage. Assessment of MAD2 levels can be used to confirm the cell-damaging activity of the compounds.