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In Europe, multiple waves of infections with SARS-CoV-2 (COVID-19) have been observed. Here, we have investigated whether common patterns of cytokines could be detected in individuals with mild and severe forms of COVID-19 in two pandemic waves, and whether machine learning approach could be useful to identify the best predictors. An increasing trend of multiple cytokines was observed in patients with mild or severe/critical symptoms of COVID-19, compared with healthy volunteers. Linear Discriminant Analysis (LDA) clearly recognized the three groups based on cytokine patterns. Classification and Regression Tree (CART) further indicated that IL-6 discriminated controls and COVID-19 patients, whilst IL-8 defined disease severity. During the second wave of pandemics, a less intense cytokine storm was observed, as compared with the first. IL-6 was the most robust predictor of infection and discriminated moderate COVID-19 patients from healthy controls, regardless of epidemic peak curve. Thus, serum cytokine patterns provide biomarkers useful for COVID-19 diagnosis and prognosis. Further definition of individual cytokines may allow to envision novel therapeutic options and pave the way to set up innovative diagnostic tools., (© 2021. The Author(s).)

In December 2019, a novel coronavirus, "SARS-CoV-2", was recognized as the cause of coronavirus disease 2019 (COVID-19). Several studies have explored the changes and the role of inflammatory cells and cytokines in the immunopathogenesis of the disease, but until today, the results have been controversial. Based on these premises, we conducted a retrospective assessment of monocyte intracellular TNF-α expression (iTNF-α) and on the frequencies of lymphocyte sub-populations in twenty-five patients with moderate/severe COVID-19. We found lymphopenia in all COVID-19 infected subjects compared to healthy subjects. On initial observation, in patients with favorable outcomes, we detected a high absolute eosinophil count and a high CD4+/CD8+ T lymphocytes ratio, while in the Exitus Group, we observed high neutrophil and CD8+ T lymphocyte counts. During infection, in patients with favorable outcomes, we observed a rise in the lymphocyte count, in the monocyte and in Treg lymphocyte counts, and in the CD4+ and in CD8+ T lymphocytes count but a reduction in the CD4+/CD8+ T lymphocyte ratio. Instead, in the Exitus Group, we observed a reduction in the Treg lymphocyte counts and a decrease in iTNF-α expression. Our preliminary findings point to a modulation of the different cellular mediators of the immune system, which probably play a key role in the outcomes of COVID-19.

Objectives: Non-transfusion-dependent thalassemia includes a variety of phenotypes and genotypes that rarely require regular transfusions. However, these patients can experience a wide range of complications. The objective of this retrospective study was to verify whether there is a significant difference in non-transfusion-dependent thalassemia-related complications and treatment among males and females., Methods: We performed a re-analysis of samples evaluated in a previously published cross-sectional study, regarding 96 non-transfusion-dependent thalassemia patients followed at the 'UOSD Malattie Rare del Globulo Rosso' Centre of the Cardarelli Hospital in Naples, Italy., Results: We found that females were more anemic than males, but there was no significant difference in prevalence of common complications among genders, except for hypogonadism. Furthermore, the transitory regular transfusions regimen in women who had been pregnant does not seem to have a significant impact on overall prognosis., Discussion: In non-transfusion-dependent thalassemia patients, the lower levels of hemoglobin found in females do not seem to indicate a higher prevalence of complications., Conclusion: This data should be considered in studies with experimental treatments aiming to correct anemia in patients with non-transfusion-dependent thalassemia. It should probably also be taken into account in order to set up different transfusion regimens among genders in transfusion-dependent patients.

We retrospectively evaluated the relationship between serum transferrin receptor-1 (sTfR1) and some fundamental events in the life and the management (the age at diagnosis, the age at the first red blood cells transfusion, the age at splenectomy, and the overall need of chelation therapy) of 111 patients with non-transfusion-dependent thalassemia (NTDT) subdivided in four genetic entities: patients with homozygous or compound heterozygous state for β-thalassemia, patients with triplicated α genotype associated with β heterozygosity, patients with deletional HbH, and patients with the combination of a β defect plus a β chain variant. We found that the group with homozygous or compound heterozygous state for β-thalassemia had the highest sTfR1 levels and that the presence of increased sTfR1 levels (>5 times normal) was associated with a complex and severe history of disease requiring splenectomy, occasional red blood cells transfusions, and early start and continuous iron chelation therapy.The complexity in the management of NTDT patients is an emerging issue due to the wide heterogeneity of clinical behavior. Our data indicate that the measurement of sTfR1 levels, a common laboratory test, could contribute to correctly stratify disease history and the iron chelation strategy in NTDT patients.

Objective: To date in Italy, there is paucity on data about the prevalence, clinical and haematological features of patients carrying the haemoglobin (Hb) Lepore variant in homozygous or in association with other haemoglobinopathies., Methods: Here we report the results of a retrospective analysis on 33 patients from Campania, a region of Southern Italy, historically followed at 'UOSD Malattie Rare del Globulo Rosso' of Cardarelli hospital, Naples, Italy., Results: We described 33 patients carrying the Hb Lepore variant: 21 compound heterozygotes with a common thalassaemia allele, six patients with homozygous state for Hb Lepore, five patients with Hb Lepore/Hb S and one patient with Hb Lepore/Hb Neapolis were identified. All individuals carried haplotype I or V., Discussion: These thalassaemic patients showed different phenotypes ranging from severe disease with early blood transfusion dependency to moderate form of thalassaemia intermedia. In most cases, thalassaemia mutation type determined the severity of the disease., Conclusion: A great variability of clinical phenotype among the same genotypes was also observed suggesting the presence of unknown genetic modifiers acting in combination with Hb Lepore.

Patients with Non-Transfusion-Dependent Thalassemia may require regular transfusion therapy. However, these patients are at risk of developing irregular antibodies, making them untransfusable. Second line treatment usually includes hydroxyurea, which however is not effective in all patients. Other treatment options include thalidomide, which has been reported to be safe and effective in selected patients. We report the case of a patient who experienced improvement of hemoglobin levels and of a part of NTDT related complications, following 36months of continuous therapy with low doses of thalidomide., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Complementary medications and herbal medicine for weight loss have become very popular. We report a case of thyroid dysfunction following the ingestion of a kelp-containing marketed diet in a 45-year-old woman with no previous thyroid disease. Signs of hyperthyroidism occurred shortly after a kelp-containing diet. Hyperthyroidism lasted 2 months and was followed by an overt hypothyroidism. The thyroid scintiscan exhibited an extremely low uptake and colour-Doppler ultrasonography revealed multiple small areas of pulsatile flow. After 3 months of levothyroxine substitutive therapy, normal thyroid function was recovered after levothyroxine discontinuation. This clinical history is compatible with a case of iodine-induced thyrotoxicosis followed by prolonged block of the sodium-iodide symporter activity as a consequence of excessive iodine consumption from kelp. Consumers of marketed diets containing kelp or other iodine-rich ingredients should be advised of the risk to develop a thyroid dysfunction also in the absence of underlying thyroid disease., (2014 BMJ Publishing Group Ltd.)

Background: The mechanisms responsible for the sporadic occurrence of extramedullary haematopoiesis in polytransfused thalassaemic patients have not yet been clarified. In this study we tried to elucidate the influence of genotype and other factors on the presence of extramedullary haematopoiesis., Materials and Methods: We performed a retrospective database review of our polytransfused thalassaemic patients between January 2006 and December 2011. Demographic, transfusional, genetic, radiological and biochemical data were collected and statistically analysed., Results: Extramedullary haematopoiesis was found in 18 out of 67 patients (27%). All of them were splenectomised, had a higher nucleated red blood cell count and higher levels of the soluble form of transferrin receptor with respect to patients without extramedullary haematopoiesis; furthermore, patients with EMH had a lower transfusional iron intake and a higher pre-transfusion haemoglobin level as compared with those without extramedullary haematopoiesis. Ten out of the 18 patients with extramedullary haematopoiesis were compound heterozygotes for IVS 1-6/codon 39. A high frequency of thrombotic events was also recorded among all patients followed at our centre with this genetic profile., Discussion: Among our cohort of thalassaemic polytransfused patients, extramedullary haematopoiesis was not such a rare event. Furthermore, we identified a group of patients, most of whom were compound heterozygotes for IVS 1-6/codon 39, with increased soluble transferrin receptor levels and excessive expansion of erythroid marrow probably responsible for the tendency to develop extramedullary haematopoiesis.

Few data are available on the prevalence and the risk factors for the presence of kidney stones and hyperuricemia in patients with thalassemia intermedia. We retrospectively reviewed the charts and radiological studies of 89 patients with thalassemia intermedia followed at our clinic with routine biochemical examination and radiological imaging of the urinary tract. Renal calculi were identified in 11 patients (12%) and 22 patients (25%) were under uricosuric treatment for hyperucemia. The prevalence of nephrolithiasis increased with age but not in a statistically significant manner. Major risk factors for renal stone formation were splenectomy (in 91% of the cases) and higher number of erythroblasts. Patients with renal stones had higher mean creatinine level and lower GFR value with respect to those observed in patients not affected. Our data suggest that splenectomy, by further increasing erythrocyte turnover and number, may be directly involved in the pathogenesis of hyperuricemia and nephrolithiasis observed in thalassemia intermedia patients., (Copyright © 2012 Elsevier Inc. All rights reserved.)

In thalassemia intermedia (TI), the increase in bone marrow hemopoietic activity frequently leads to extramedullary erythropoeisis (EMH), but its relationship with the soluble form of transferrin receptor (sTfR) which fully reflects the marrow erythropoietic activity, has not yet been explored. From January 2007 to December 2010, all TI patients attending at our center were prospectively enrolled to undergo sTfR assay and MRI or CT (if claustrophobic) scan evaluation for the presence of paraspinal EMH. A total of 59 patients with TI were studied; EMH involved 23 (39%) patients; overall, the concentration of sTfR varied from 2.6 to 20.6 (mean = 8.7) mg/L, but in splenectomized group and in unsplenectomized group, it varied from 4.2 to 17.8 (mean ± SD = 9.86 ± 3.33) mg/L and from 2.6 to 20.6 (mean ± SD = 7.25 ± 3.9) mg/L, respectively with a statistically significant intergroup difference (p < 0.01). The cutoff point at 8.6 mg/L using the ROC curve showed a sensitivity of 78.3% and a specificity of 72.2%, in predicting EMH but, in unsplenectomized subgroup, they raised to 100% and 90.9%, respectively. These data showed that in TI the level of sTfR could represent a predictive factor of EMH particularly in patients with spleen.

In this report, we present a case of a spontaneous pregnancy in a 42-year-old thalassemic woman referred to our Microcythemic Unit while she was on deferasirox (DFX) therapy. The patient had been on treatment with DFX since March 2008 and in March 2009 realized that she was pregnant at 12 weeks of gestation. The conception was spontaneous and the baby was born at full term without complications or malformations., (Copyright © 2011 S. Karger AG, Basel.)

Objective: Although IFN therapy is known to cause neutropenia, data on the risk of deferiprone (DFP)-induced haematological complications in patients receiving IFN are lacking., Research Design and Methods: This was a retrospective single-centre study to assess the association between exposure to IFN for hepatitis C virus treatment and haematological side effects of DFP therapy in patients with thalassemia major and intermedia using a large database spanning 2001 – 2008. During observation time, a total of 66 patients, including 63 affected by thalassemia major and 3 by thalassemia intermedia, were treated with chelation DFP-based regimens. A subset of 25 patients was treated at least for 3 months also with IFN (6 were cotreated and 19 were pretreated)., Results: Overall, the incidence of neutropenia and agranulocytosis was 9.83 and 1.14/100 patient/year, respectively. Receipt of IFN was significantly associated with increased risk of haematological complications of DFP therapy: among patients receiving IFN, 48 and 12% experienced at least one episode of neutropenia and agranulocytosis, respectively., Conclusions: These results suggest that IFN therapy may increase the risk of complications of DFP-based iron chelation therapy in patients with thalassemia. Further research is needed to assess whether the association observed in this retrospective single-centre observational study is due to IFN or other factors.

N(6)-isopentenyladenosine (i6A) inhibits the tumor cell growth by inducing cell apoptosis in various cancer cell lines. However, little is known regarding the mechanisms by which the drug induces cell apoptosis. In this study, we further explored the molecular mechanisms of i6A as an anticancer agent on a human breast cancer cell line MDA MB 231. Treatment with i6A decreased the cell proliferation of MDA MB 231 cells in a dose-dependent manner by arresting the cells at G(0)/G(1) phase. This effect was strongly associated with concomitant decrease in the level of cyclin D1, cyclin E, cdk2, and increase of p21waf1 and p27kip. In addition i6A also induced apoptotic cell death by increasing the expression of Bax, and decreasing the levels of Bcl-2 and Bcl-xL, and subsequently triggered mitochondria apoptotic pathway (release of cytochrome c and activation of caspase-3). We observed that i6A suppressed the nuclear factor kappaB (NF-κB) pathway and inhibited the Akt activation. The results of this study indicate that i6A decreases cell proliferation and induces apoptotic cell death in human breast cancer cells, possibly by decreasing signal transduction through the Akt/NF-κB cell survival pathway., (© 2010 Wiley-Liss, Inc.)

Objectives: The benefits of combined chelation therapy with daily deferiprone (DFP) and subcutaneous desferrioxamine (DFO) have been widely reported in literature. We retrospectively evaluated the efficacy of different schedules of combined chelation therapy and the incidence of adverse events., Methods: We evaluated 36 patients affected by thalassemia major treated with combined chelation therapy. Patients were subdivided into four treatment arms according to severity of iron overload and previous onset of adverse events to DFP therapy: Group 1 (13 pts) DFP 75 mg/kg per d plus DFO (25-35 mg/kg per d for 5 d); Group 2 (6 pts) DFP 50 mg/kg per d plus DFO (25-35 mg/kg for 5 d), Group 3 (10 pts) DFP 75 mg/kg per d plus DFO (25-35 mg/kg for 3 d), and Group 4 (7 pts) DFP 50 mg/kg per d plus DFO (25-35 mg/kg for 3 d). Change in serum ferritin level was evaluated in all patients., Results: Overall, ferritin decreased from 2592 +/- 1701 to 899 +/- 833 ng/mL (P < 0.001). All treatments were able to reduce ferritin levels, but in patients of group 1 and group 2 the highest mean decrease in serum ferritin level and the greatest improvement in liver iron concentration (LIC) and in T2* values were observed., Conclusions: This study showed that the administration of DFO for 5 d a wk in combination with daily administration of DFP at 75 mg/Kg seemed to be the most efficacy and rapid method for reducing iron overload at liver and heart level. Furthermore, the use of different schedules of combined DFO and DFP administration was not associated with different incidence of adverse effects between the groups.

In this report we present a 37-year-old thalassemia patient with hyperferritinemia referred to our Microcytemia Centerat the beginning of deferasirox (DFX) therapy. Treatment with subcutaneous infusions of desferrioxamine (DFO) had started when he was 10 years old. During the 6-month DFX treatment, serum ferritin levels progressively increased from 600 to 2,700 ng/ml despite progressive DFX dose adjustments.This paradoxically abnormal ferritin levels required drug discontinuation but were not paralleled by a similar iron burden in T2 * magnetic resonance imaging. In this clinical case, ferritin levels were inappropriately increased following initiation of DFX treatment, but in the presence of an almost unmodified pattern of organ iron overload. Excluding the diagnostic dilemma of an improbable failure of DFX chelation, the pathogenesis of this phenomenon remains to be clarified, thus further complicating the problem of ferritin specificity and its role in monitoring chelation efficacy and in adapting DFX dosage in a limited period of treatment.

N(6)-isopentenyladenosine (i6A) is a modified nucleoside with a pentaatomic isopentenyl derived from mevalonate that induces inhibition of tumor cell proliferation and apoptosis in several tumor cell lines. In this study, we reported that N(6)-isopentenyladenosine inhibited the proliferation and promotes apoptosis in DLD1 human colon cancer cells. It suppressed the proliferation of cells through inhibition of DNA synthesis, causing a cell cycle arrest that correlated with a decrease in the levels of cyclin E, cyclin A and cyclin D1 and with a concomitant increase in the levels of cyclin-dependent kinase inhibitor p21waf and p27kip1. Moreover, it induced apoptosis through an increase in the number of annexin V-positive cells, a downregulation of antiapoptotic products and caspase-3 activation. The apoptotic effects of N(6)-isopentenyladenosine were accompanied by sustained phosphorylation and activation of c-jun N-terminal kinase (JNK) that induced phosphorylation of c-jun. Overall, our data show that JNK, could play an important role in i6A-mediated apoptosis in DLD1 human colon cancer cells.

Objectives: Hypocholesterolemia has been previously described in patients affected by thalassemia. In this study we retrospectively evaluated the cholesterol level in two groups of patients affected by either thalassemia major (TM) or thalassemia intermedia (TI), with the aim of establishing factors correlated to hypocholesterolemia within both populations., Methods: All patients referring to our Unit of Thalassemia were considered. Observation time, defined as the interval between the first and last set of laboratory test, was 2 yr (January 2005-December 2006)., Results: We found that patients with TI had significantly lower cholesterol and hemoglobin level as compared with TM patients. In addition there was no correlation between groups with identical genotype and cholesterol levels in both populations. However, within the TI group, lower values of cholesterol were found in patients with more severe genotype and lower body mass index., Conclusions: Our data support the hypothesis that, independently from single genotype involved, the reduced level of cholesterol in patients with TI are sustained by active erythropoiesis which increases cholesterol requirement.

In this report we firstly describe a case of reactivation of hepatitis B virus (HBV) replication occurred in a patient affected by Thalassemia major which underwent a combined chelation therapy with desferioxamine (DFO) and deferiprone (DFP). Clinical symptom and increase in alanine aminotransferase (ALT) level were detected when the prescription of DFO (30 mg/kg) was increased from 3 to 5 days/week; a raise in HBV-DNA levels of greater than or equal to tenfold compared with baseline was thereafter detected. Diagnosis was troublesome because increasing ALT levels, first suggested toxicity to DFP administration. However, HBV reactivation in our patient cannot be definitively attributed to combined regimen administration: the patient was on regular transfusion therapy and either coincidental further infection or spontaneous reactivation of HBV could not be completely ruled out. Furthermore, a background of immunologic abnormalities had been previously reported in thalassemia and postulated to be secondary to iron overload or DFO therapy itself.

Aspirin displays, at millimolar concentrations, several mechanisms independent from its ability to inhibit cyclooxygenases. Occasionally, the mechanisms displayed in vitro have been clearly related to an effect of clinical relevance in vivo. An expanding literature has been focusing on the cytoprotective effect of aspirin in neurodegenerative disorders and the activation of AKT pathway in neuroprotection and induction of resistance to anticancer drugs. In this work, we tested the ability of aspirin to activate the AKT survival pathway in methylcholanthrene-induced fibrosarcoma cells (Meth A) transplanted into BALB/c nude mice and the clinical effect of aspirin cotreatment during etoposide (VP-16)-based anticancer therapy. We found that cotreatment with aspirin reduced VP-16-induced apoptosis and activated AKT in vitro and in vivo. In Meth A-bearing mice, aspirin administration also activated glycogen synthase kinase-3 and reduced the activity and the efficacy of anticancer therapy in VP-16 cotreated animals. Our data suggest that the antiapoptotic effect of aspirin operates in vivo through the activation of AKT-glycogen synthase kinase pathway causing a decrease in the outcome of VP-16-based therapy. These findings could have clinical relevance in treatment of human malignancies.

Integrin activation generates different signalings in a cell type-dependent manner and stimulates cell proliferation through the Ras/Raf-1/Mek/Erk pathway. In this study, we demonstrate that integrin stimulation by fibronectin (FN), besides activating the Ras/Erk pathway, generates an auxiliary calcium signal that activates calmodulin and the Ca2+/calmodulin-dependent protein kinase II (CaMKII). This signal regulates Raf-1 activation by Ras and modulates the FN-stimulated extracellular signal-regulated kinase (Erk-1/2). The binding of soluble FN to integrins induced increase of intracellular calcium concentration associated with phosphorylation and activation of CaMKII. In two different cell lines, inhibition of CaMKII activity by specific inhibitors inhibited Erk-1/2 phosphorylation. Whereas CaMK inhibition affected neither integrin-stimulated Akt phosphorylation nor p21Ras or Mek-1 activity, it was necessary for Raf-1 activity. FN-induced Raf-1 activity was abrogated by the CaMKII specific inhibitory peptide ant-CaNtide. Integrin activation by FN induced the formation of a Raf-1/CaMKII complex, abrogated by inhibition of CaMKII. Active CaMKII phosphorylated Raf-1 in vitro. This is the first demonstration that CaMKII interplays with Raf-1 and regulates Erk activation induced by Ras-stimulated Raf-1. These findings also provide evidence supporting the possible existence of cross-talk between other intracellular pathways involving CaMKII and Raf-1.

Cell adhesion to extracellular matrix regulates proliferation and survival of several cell types including epithelial thyroid cells. Activation of integrin receptors by binding to extracellular matrix generates a complex cell type-dependent signaling. Adhesion to extracellular matrix induces proliferation and survival in primary cultures of thyroid cells and induces survival in immortalized human thyrocytes. In this study we demonstrate that in immortalized human thyrocyte cells, adhesion to immobilized fibronectin (FN) stimulates DNA synthesis and proliferation through the p21Ras/MAPK pathway, whereas cell survival is mediated by phosphatidylinositol 3-kinase (PI3K) signal pathway. Integrin activation by immobilized FN induced phosphorylation of pp125 focal adhesion kinase and paxillin and induced the formation of focal adhesion kinase/Grb-2/Sos complex. Western blot and in vitro kinase assay demonstrated the activation of Ras and the p44/p42 MAPK/ERK1/2. Inhibition of p21Ras activity and inhibition of MAPK enzymatic activity completely arrested cell growth but did not induce cell death. Integrin activation by cell adhesion to FN also induced activation of PI3K. Inhibition of PI3K enzymatic activity induced apoptosis demonstrated by annexin V-binding assay and loss of cellular DNA content. These results demonstrate that in thyroid cells adhesion to FN regulates proliferation through the p21Ras/MAPK signal pathway, whereas integrin-mediated cell survival is mediated by PI3K.

Amiodarone (AMD) is one of the most effective antiarrhythmic drugs available. However, its use is often limited by side-effects, mainly hypo- or hyperthyroidism. As AMD displays direct toxic effect on different cell types, we investigated the cytotoxic effect of AMD and its main metabolite, desethylamiodarone (DEA), in thyroid (TAD-2) and nonthyroid (HeLa) cell lines. Both AMD and DEA displayed a dose-dependent toxicity in TAD-2 and HeLa cells, although DEA was more effective. Both TAD-2 and HeLa cells underwent apoptosis, as evidenced by plasma membrane phosphatidylserine exposure and DNA fragmentation. Inhibition of protein synthesis with cycloheximide and inhibition of endogenous peroxidase activity with propylthiouracil did not affect this AMD- and DEA-induced apoptosis in TAD-2 cells. Western blot analysis did not display variations in the expression of p53, Bcl-2, Bcl-XL, and Bax proteins during the treatment with AMD and DEA. Generation of reactive oxygen species, investigated by flow cytometry with dichlorofluorescein diacetate, did not show the production of free radicals during drug treatment. Furthermore, Western blot analysis of cytosolic and mitochondrial fractions prepared from AMD-treated cells demonstrated that AMD induces the release of cytochrome c into the cytosol from the mitochondria. These data indicate that AMD induces cytochrome c release from mitochondria, triggering apoptosis through an iodine-independent mechanism, and that this process is not mediated by modulation of p53, Bcl-2, Bcl-XL, or Bax protein expression and does not involve the generation of free radicals.

In some cell types, including a fetal thyroid cell line, denial of adhesion to extracellular matrix induces a type of apoptosis called anoikis. Serum withdrawal in dog and transformed rat thyroid cells also induces programmed cell death. Because serum can stimulate cells to produce some components of the extracellular matrix, it was of interest to determine the role of the matrix in the apoptosis induced by serum withdrawal in normal human thyroid cells in primary culture. The present report demonstrates that thyroid cells selectively produce and deposit insoluble fibronectin (FN) only when stimulated by serum. Adhesion in the presence of serum is dependent upon integrin-FN interaction. Serum withdrawal determines a degradation of the insoluble FN deposited and a detachment of the cells from the plates. In these conditions, cells undergo anoikis, demonstrated by DNA fragmentation and annexin V staining. Apoptosis was prevented by exogenous FN immobilized onto the plates. These results indicate that serum withdrawal induces apoptosis in human thyroid cells, determining FN degradation and loss of cell-matrix adhesion.

Thyroid toxicity of iodide excess has been demonstrated in animals fed with an iodide-rich diet; in vitro iodide is cytotoxic, inhibits cell growth, and induces morphological changes in thyroid cells of some species. In this study, we investigated the effect of iodide excess in an immortalized thyroid cell line (TAD-2) in primary cultures of human thyroid cells and in cells of nonthyroid origin. Iodide displayed a dose-dependent cytotoxicity in both TAD-2 and primary thyroid cells, although at different concentrations, whereas it had no effect on cells of nonthyroid origin. Thyroid cells treated with iodide excess underwent apoptosis, as evidenced by morphological changes, plasma membrane phosphatidylserine exposure, and DNA fragmentation. Apoptosis was unaffected by protein synthesis inhibition, whereas inhibition of peroxidase enzymatic activity by propylthiouracil completely blocked iodide cytotoxicity. During KI treatment, reactive oxygen species were produced, and lipid peroxide levels increased markedly. Inhibition of endogenous p53 activity did not affect the sensitivity of TAD-2 cells to iodide, and Western blot analysis demonstrated that p53, Bcl-2, Bcl-XL, and Bax protein expression did not change when cells were treated with iodide. These data indicate that excess molecular iodide, generated by oxidation of ionic iodine by endogenous peroxidases, induces apoptosis in thyroid cells through a mechanism involving generation of free radicals. This type of apoptosis is p53 independent, does not require protein synthesis, and is not induced by modulation of Bcl-2, Bcl-XL, or Bax protein expression.

In normal epithelial cells, impaired cell-matrix contact leads to induction of programmed cell death, a process that has been termed 'anoikis'. We investigated the role of p53 and other apoptotic proteins in anoikis in thyroid epithelial cells. Western blot analysis demonstrated that neither p53 nor Bcl-2, Bcl-XL and Bax protein expression changed during anoikis. However, loss of endogenous p53 activity in cells transfected with a dominant-negative mutated p53 inhibited anoikis demonstrating the involvement of p53-dependent processes. The phosphatase inhibitor sodium orthovanadate opposed anoikis when added to the cells within 6 h, suggesting a role for phosphorylated proteins.

The inhibitors of protein prenylation have been proposed for chemotherapy of tumors. Lovastatin, a 3-hydroxy-3-methylglutaryl-Coenzyme A (HMG-CoA) reductase inhibitor, displays proapoptotic activity in tumor cells blocking the synthesis of isoprenoids compounds. To test whether HMG-CoA reductase inhibition can induce apoptosis in proliferating thyroid cells, we studied the effects of lovastatin in normal and neoplastic thyroid cells and in primary cultures from normal human thyroids. In an immortalized human thyroid cell line (TAD-2) and in neoplastic cells, lovastatin induced cell rounding within 24 h of treatment. After 48 h the cells were detached from the plate and underwent apoptosis, as evidenced by DNA fragmentation. Morphological changes and apoptosis did not occur in serum-starved quiescent TAD-2 cells or in primary cultures of normal thyrocytes. Mevalonate, the product of the HMG-CoA reductase enzymatic activity, and the protein synthesis inhibitor cycloheximide completely blocked the effects of lovastatin in a dose-dependent fashion. The geranylgeranyl transferase GGTI-298 inhibitor mimicked the effects of lovastatin on cell morphology and induced cell death, whereas the farnesyl transferase inhibitor FTI-277 was less effective to induce both cell rounding and apoptosis. Resistance to lovastatin-induced apoptosis by expression of the viral serpine CrmA and by the peptide inhibitor of caspases, Z-DEVD-fmk, demonstrated the involvement of CrmA-sensitive, caspase-3-like proteases. Inhibition of endogenous p53 activity did not affect the sensitivity of thyroid cells to lovastatin, demonstrating that this type of apoptosis is p53 independent. We conclude that lovastatin is a potent inducer of apoptosis in proliferating thyroid cells through inhibition of protein prenylation. This type of apoptosis requires protein synthesis, is CrmA sensitive and caspase-3-like protease dependent, and is independent from p53.

Apoptosis or programmed cell death occurs in a wide variety of cell types when adhesion to extracellular matrix (ECM) is denied. Invasion and metastasis by tumor cells involve the loss of normal cell-ECM contacts and require independence from such control mechanisms. We studied whether the immortalized thyroid cell line TAD-2 is a model suitable to investigate thyroid cell-ECM interaction, and we analyzed the role of integrin-fibronectin (FN) interaction in apoptosis. Adhesion, spreading, and cytoskeleton organization in TAD-2 cultured cells were dependent upon integrin-FN interaction. Cell spreading and cytoskeletal organization were coupled to deposition of insoluble FN induced by serum. Expression of integrin-FN receptors was demonstrated by flow cytofluorometry with specific antibodies, and strong integrin-dependent adhesion was demonstrated by attachment assays to immobilized FN. Apoptosis, occurring in different culture conditions, was determined by cell morphology and DNA electrophoretic analysis and quantitated by flow cytometry in propidium iodide-stained cells. Thyroid cells underwent apoptosis in the presence of serum when adhesion was prevented by specific peptides that inhibit integrin binding to FN (RGD-containing peptides) or by coating the culture plates with agar. In serum-free cultures, apoptosis was prevented by insoluble FN immobilized on the plates, but not by soluble FN. These results suggest that the TAD-2 cell line is a good model to study thyroid cell-ECM interaction, that FN, assembled into insoluble matrix, is required for cytoskeletal organization and to prevent thyroid cell apoptosis, and that integrin-mediated adhesion is involved in this process.

The expression of integrins of the beta1 family and their possible biological effects were investigated in normal human thyroid cells in monolayer culture. The expression of beta1 and alpha(1-6) integrin subunits was determined by flow cytofluorometry with specific antibodies. Follicular cells of subconfluent monolayer cultures expressed alpha2beta1 and alpha3beta1 at high levels, while alpha1beta1 was only slightly expressed, and alpha4beta1, alpha5beta1, and alpha6beta1 were never detected. Cell attachment assays were performed in fibronectin-, type I collagen-, and laminin-coated microtiter plates. Thyroid cells, while adherent to collagen and fibronectin, showed poor attachment to laminin despite the abundance of their putative receptors alpha2beta1 and alpha3beta1. In serum-free medium, collagen and fibronectin induced cytoskeletal organization, change of cell shape from round to flat, and cell spreading. [3H]Thymidine incorporation and proliferation assays were used to evaluate the effects of collagen and fibronectin on DNA synthesis and cell growth in the absence of a change in spreading or cell shape. Both substrates, in low serum-containing medium, induced a concentration-dependent increase in [3H]thymidine incorporation partially inhibited by RGD-containing peptides that blocked the cell attachment. Thyrocytes cultured in low serum-containing medium on immobilized fibronectin or collagen showed a dose-dependent stimulation of proliferation. These data indicate that fibronectin and collagen can regulate the cytoskeletal organization and cell shape and stimulate the proliferation of normal human thyroid cells in culture and that integrins mediate these effects of extracellular matrix proteins.