Tiziana Di Matola

Iodide excess induces apoptosis in thyroid cells through a p53-independent mechanism involving oxidative stress.

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 mark...

Prenyltransferase Inhibitors Induce Apoptosis in Proliferating Thyroid Cells through a p53-Independent, CrmA-Sensitive, and Caspase-3-Like Protease- Dependent Mechanism*

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...

N6-isopentenyladenosine inhibits cell proliferation and induces apoptosis in a human colon cancer cell line DLD1.

N6‐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 N6‐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 N6‐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

Apoptosis induced by denied adhesion to extracellular matrix (anoikis) in thyroid epithelial cells is p53 dependent but fails to correlate with modulation of p53 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.

Involvement of Akt/NF-κB pathway in N6-isopentenyladenosine-induced apoptosis in human breast cancer cells.

N6‐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 G0/G1 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.

Splenectomy is a risk factor for developing hyperuricemia and nephrolithiasis in patients with thalassemia intermedia: a retrospective study.

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.

Thyroid dysfunction following a kelp-containing marketed diet

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.

The long-term and extensive efficacy of low dose thalidomide in a case of an untransfusable patient with Non-Transfusion-Dependent Thalassemia

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.

Nephrolithiasis in patients exposed to deferasirox and desferioxamine: probably an age-linked event with different effects on some renal parameters

Dear Editor, We refer this letter to the manuscript by Efthimia et al. [1] in which they recently reported that in thalassemia major (TM) patients, the start of deferasirox (DFX) has been associated with increased risk of developing nephrolithiasis. However, in that series, several patients were also cotreated with calcium and vitamin D supplements, and the authors correctly hypothesized that it could have facilitated the renal calculi formation. Nevertheless, that clinical observation was not easy to evaluate by the fact that it was not a population-based case– control study and the definition of the population and the duration of patient exposure to DFX treatment were not reported; furthermore, the assessment of new cases was made only through the detection of renal colic. We reviewed the charts and radiological studies of our patients with TM to retrospectively evaluate the incidence of nephrolithiasis in those treated with DFX and in a matched control population treated with desferioxamine (DFO). The presence or the absence of nephrolithiasis had to be assessed by abdominal ultrasonography. To further analyze data, total therapy exposure and the incidence of nephrolithiasis adjusted to 100 years of patient exposure were calculated for each treatment. To make series comparable, data from patients under DFO treatment were collected since January 2010. The study was approved by the Ethics Committee of the Cardarelli Hospital, Napoli. Table 1 shows demographics and clinical characteristics of patients divided in those exposed to DFX and to DFO at baseline and at the end of drug exposure (October 2012). At baseline, both populations were comparable for previous chelation history, for the percentage of patients splenectomized and using calcium and vitaminD, for the mean creatinine level and GFR value, and for the prevalence of renal calculi [2], but patients treated with DFX tended to be younger and to have lower level of uric acid. Patients already affected by renal calculi were in average 40 years old and frequently splenectomized, but they did not use vitamin D and calcium supplementation more frequently than those without stones and were not always symptomatic; however, in those under DFO treatment, a decrease in GFR was observed following drug exposure. Comparing basal and final values in a population without stones, an increase in creatinine level and a decrease in GFR were observed in the DFX group. We observed eight (5.26/100 patients/year ) and five (4.76/100 patients/year) new cases of renal stones in patients treated with DFX and DFO, respectively, and the O.R. for developing nephrolithiasis under DFX was 1.17 , p=0.79 (data not shown). Interestingly, among stone formers following DFX treatment, a significant decrease in uric acid level without a decrease in renal function parameters was observed. Estimates of the incidence of renal stones in TM patients are lacking [3]. In spite of this, a sustained rate of renal stone formation under DFX treatment was confirmed; these data highlight the presence of an asymptomatic disease that may have contributed to its underestimation in the DFO group in Efthimia’s series [1]. In our series, renal stone formation appears to involve mainly patients older than 30 while the P. Ricchi :M. Ammirabile : S. Costantini :A. Spasiano : P. Cinque :M. Casale :A. Filosa : L. Prossomariti UOSD Centro delle Microcitemie “A. Mastrobuoni”, AORN A. Cardarelli, Naples, Italy

Hepatitis C virus distribution and clearance following interferon-monotherapy among thalassaemia major and intermedia patients.

Additional Supporting Information may be found in the online version of this article: Table SI. Complete Steady state plasma amino acid concentrations in SCA patients who subsequently died compared to age and sex matched SCA patients who were alive as of 1st July 2009. Table SII. Available laboratory markers of hemolysis and liver and kidney function in patients at enrollment into the cohort (steady-state) and at the time of amino acid steady-state sample collection. Please note: Wiley-Blackwell are not responsible for the content or functionality of any supporting materials supplied by the authors. Any queries (other than missing material) should be directed to the corresponding author for the article.