Alberto Abbruzzese

Familial papillary thyroid microcarcinoma: a new clinical entity

BACKGROUND Familial, non-medullary thyroid carcinoma is clinically more aggressive than the sporadic form. We wanted to find out whether papillary thyroid microcarcinoma also occurs in a familial pattern, and, if so, to identify specific clinical and prognostic features. METHODS We reviewed the clinical records of 119 patients with papillary thyroid microcarcinoma. Familial occurrence, together with clinical presentation, surgical treatment, pathological characteristics, and follow-up were recorded. FINDINGS We identified a family history of thyroid carcinoma in seven patients. The tumour was multifocal in five patients, bilateral in three, and vascular invasion occurred in three of the seven patients. Lymph-node metastases were found in four patients. Three patients had a recurrence and one patient with pulmonary metastases died within 11 months. INTERPRETATION We identified familial occurrence in 5.9% of cases of papillary thyroid microcarcinoma. The unfavourable behaviour in the familial form of papillary thyroid microcarcinoma suggests that radical treatment and careful follow-up are warranted.

Molecular targets and oxidative stress biomarkers in hepatocellular carcinoma: an overview

Hepatocellular carcinoma (HCC) is a complex and heterogeneous tumor with multiple genetic aberrations. Several molecular pathways involved in the regulation of proliferation and cell death are implicated in the hepatocarcinogenesis. The major etiological factors for HCC are both hepatitis B virus (HBV) and hepatitis C virus infection (HCV).Continuous oxidative stress, which results from the generation of reactive oxygen species (ROS) by environmental factors or cellular mitochondrial dysfunction, has recently been associated with hepatocarcinogenesis. On the other hand, a distinctive pathological hallmark of HCC is a dramatic down-regulation of oxido-reductive enzymes that constitute the most important free radical scavenger systems represented by catalase, superoxide dismutase and glutathione peroxidase.The multikinase inhibitor sorafenib represents the most promising target agent that has undergone extensive investigation up to phase III clinical trials in patients with advanced HCC. The combination with other target-based agents could potentiate the clinical benefits obtained by sorafenib alone. In fact, a phase II multicenter study has demonstrated that the combination between sorafenib and octreotide LAR (So.LAR protocol) was active and well tolerated in advanced HCC patients.The detection of molecular factors predictive of response to anti-cancer agents such as sorafenib and the identification of mechanisms of resistance to anti-cancer agents may probably represent the direction to improve the treatment of HCC.

Critical role of both p27KIP1 and p21CIP1/WAF1 in the antiproliferative effect of ZD1839 ('Iressa'), an epidermal growth factor receptor tyrosine kinase inhibitor, in head and neck squamous carcinoma cells.

High expression of the epidermal growth factor receptor (EGFR) has been implicated in the development of squamous‐cell carcinomas of head and neck (SCCHN). ZD1839 (‘Iressa’) is an orally active, selective EGFR‐TKI (EGFR‐tyrosine kinase inhibitor) that blocks signal transduction pathways implicated in proliferation and survival of cancer cells, and other host‐dependent processes promoting cancer growth. We have demonstrated that ZD1839 induces growth arrest in SCCHN cell lines by inhibiting EGFR‐mediated signaling. Cell cycle kinetic analysis demonstrated that ZD1839 induces a delay in cell cycle progression and a G1 arrest together with a partial G2/M block; this was associated with increased expression of both p27KIP1 and p21CIP1/WAF1 cyclin‐dependent kinase (CDK) inhibitors. The activity of CDK2, the main target of CIP/KIP CDK inhibitors, was reduced in a dose‐dependent fashion after 24 h of ZD1839 treatment and this effect correlated to the increased amount of p27KIP1 and p21CIP1/WAF1 proteins associated with CDK2‐cyclin‐E and CDK2‐cyclin‐A complexes. In addition, ZD1839‐induced growth inhibition was significantly reduced in cell transfectants expressing p27KIP1 or p21CIP1/WAF1 antisense constructs. Overall, these results as well as the timing of the effect of ZD1839 on G1 arrest and p27KIP1 and p21CIP1/WAF1 upregulation, suggest a mechanistic connection between these events.

The translation elongation factor 1A in tumorigenesis, signal transduction and apoptosis: Review article

Summary.An increasing number of evidences suggest the involvement of the eukaryotic elongation factor 1A, a core component of the protein synthesis machinery, at the onset of cell transformation. In fact, eEF1A is shown to be up-regulated in cell death; moreover, it seems to be involved in the regulation of ubiquitin-mediated protein degradation. In addition, eEF1A undergoes several post-translational modifications, mainly phosphorylation and methylation, that generally influence the activity of the protein. This article summarizes the present knowledges on the several extra-translational roles of eEF1A also in order to understand as the protein synthesis regulatory mechanisms could offer tools for cancer intervention.

Zoledronic acid induces antiproliferative and apoptotic effects in human pancreatic cancer cells in vitro

Bisphosphonates (BPs) are an emerging class of drugs mostly used in the palliative care of cancer patients. We investigated the in vitro activity of the most potent antiresorptive BP, zoledronic acid (ZOL), on the growth and survival of three human pancreatic cancer (PC) cell lines (BxPC-3, CFPAC-1 and PANC-1). Pancreatic cancer frequently has a dysregulated p21ras pathway and therefore appears to be a suitable target for BPs that interfere with the prenylation of small GTP-binding proteins such as p21ras. We found that ZOL induces growth inhibition (IC50:10–50 μM) and apoptotic death of PC cells. The proapoptotic effect was correlated to cleavage/activation of caspase-9 and poly(ADP)-ribose polymerase, but not of caspase-3. Moreover, we studied the p21ras signalling in cells exposed to ZOL and detected a reduction of p21ras and Raf-1 content and functional downregulation of the terminal enzyme ERK/MAPkinase and of the pKB/Akt survival pathway. Finally, we observed that ZOL induces significant cytoskeletal rearrangements. In conclusion, we demonstrated that ZOL induces growth inhibition and apoptosis on PC cells and interferes with growth and survival pathways downstream to p21ras. These findings might be relevant for expanding application of BPs in cancer treatment.

Alpha‐interferon and its effects on signal transduction pathways

Interferon‐α (IFNα) is a recombinant protein widely used in the therapy of several neoplasms such as myeloma, renal cell carcinoma, epidermoid cervical and head and neck tumors, and melanoma. IFNα, the first cytokine to be produced by recombinant DNA technology, has emerged as an important regulator of cancer cell growth and differentiation, affecting cellular communication and signal transduction pathways. However, the way by which tumor cell growth is directly suppressed by IFNα is not well known. Wide evidence exists on the possibility that cancer cells undergo apoptosis after the exposure to the cytokine. Here we will review the consolidate signal transducer and activator of transcription (STAT)‐dependent mechanism of action of IFNα. We will discuss data obtained by us and others on the triggering of the stress‐dependent kinase pathway induced by IFNα and its correlations with the apoptotic process. The regulation of the expression of proteins involved in apoptosis occurrence will be also described. In this regard, IFNα is emerging as a post‐translational controller of the intracellular levels of the apoptosis‐related protein tissue transglutaminase (tTG). This new way of regulation of tTG occurs through the modulation of their proteasome‐dependent degradation induced by the cytokine. Until today, inconsistent data have been obtained regarding the clinical effectiveness of IFNα in the therapy of solid tumors. In fact, the benefit of IFNα treatment is limited to some neoplasms while others are completely or partially resistant. The mechanisms of tumor resistance to IFNα have been studied in vitro. The alteration of JAK‐STAT components of the IFNα‐induced signaling, can be indeed a mechanism of resistance to IFN. However, we have recently described a reactive mechanism of protection of tumor cells from the apoptosis induced by IFNα dependent on the epidermal growth factor (EGF)‐mediated Ras/extracellular signal regulated kinase (Erk) signaling. The involvement of the Ras→Erk pathway in the protection of tumor cells from the apoptosis induced by IFNα is further demonstrated by both Ras inactivation by RASN17 transfection and mitogen extracellular signal regulated kinase 1 (Mek‐1) inhibition by exposure to PD098059. These data strongly suggest that the specific disruption of the latter could be a useful approach to potentiate the antitumour activity of IFNα against human tumors based on the new mechanistic insights achieved in the last years.

Electromagnetic Fields at Mobile Phone Frequency Induce Apoptosis and Inactivation of the Multi-chaperone Complex in Human Epidermoid Cancer Cells

The exposure to non‐thermal microwave electromagnetic field (MW‐EMF) at 1.95 MHz, a frequency used in mobile communication, affects the refolding kinetics of eukaryotic proteins (Mancinelli et al., 2004 ). On these basis we have evaluated the in vivo effect of MW‐EMF in human epidermoid cancer KB cells. We have found that MW‐EMF induces time‐dependent apoptosis (45% after 3 h) that is paralleled by an about 2.5‐fold decrease of the expression of ras and Raf‐1 and of the activity of ras and Erk‐1/2. Although also the expression of Akt was reduced its activity was unchanged likely as a consequence of the increased expression of its upstream activator PI3K. In the same experimental conditions an about 2.5‐fold increase of the ubiquitination of ras and Raf‐1 was also found and the addition for 12 h of proteasome inhibitor lactacystin at 10 μM caused an accumulation of the ubiquitinated isoforms of ras and Raf‐1 and counteracted the effects of MW‐EMF on ras and Raf‐1 expression suggesting an increased proteasome‐dependent degradation induced by MW‐EMF. The exposure of KB cells to MW‐EMF induced a differential activation of stress‐dependent pathway with an increase of JNK‐1 activity and HSP70 and 27 expression and with a reduction of p38 kinase activity and HSP90 expression. The overexpression of HSP90 induced by transfection of KB cells with a plasmid encoding for the factor completely antagonized the apoptosis and the inactivation of the ras → Erk‐dependent survival signal induced by MW‐EMF. Conversely, the inhibition of Erk activity induced by 12 h exposure to 10 mM Mek‐1 inhibitor U0126 antagonized the effects induced by HSP90 transfection on apoptosis caused by MW‐EMF. In conclusion, these results demonstrate for the first time that MW‐EMF induces apoptosis through the inactivation of the ras → Erk survival signaling due to enhanced degradation of ras and Raf‐1 determined by decreased expression of HSP90 and the consequent increase of proteasome dependent degradation.

Desferioxamine increases iron depletion and apoptosis induced by ara‐C of human myeloid leukaemic cells

We investigated whether changes in iron metabolism and the transferrin receptor (TRF‐R) expression were involved in the antileukaemic effects of arabinoside cytosine (ara‐C). Treatment with 100 n M ara‐C for 48 h reduced thymidine uptake and increased the surface expression of the TRF‐R on leukaemic blasts derived from 13/16 (81%) patients and on the HL‐60 and U‐937 cell lines. Whereas intracellular non‐haem iron was strongly depleted 24 h after ara‐C addition, TRF‐R up‐regulation and recovery of intracellular non‐haem iron concentration occurred together after a longer exposure of the cultured cells to the drug. Since iron is an essential regulator of cell proliferation we have evaluated the effects of the combination between ara‐C and the iron chelator desferioxamine (DSF) on the growth of HL‐60 and U‐937 cells. We found that desferioxamine strongly potentiated the effects of ara‐C on leukaemic cell growth inhibition and apoptosis. This is the first report of a positive interaction between ara‐C and an iron chelator in terms of antileukaemic effects.

Pamidronate improves the quality of life and induces clinical remission of bone metastases in patients with thyroid cancer

Skeletal metastases from thyroid cancer are poorly responsive to medical or radioiodine treatment. Bone destruction in skeletal metastases results from osteoclast-induced bone resorption. Therefore, a new approach in the therapy of bone metastases consists in using aminobisphosphonates, such as pamidronate, which are potent inhibitors of osteoclastic activity. In the present study, 10 thyroid cancer patients with painful osteolytic bone metastases were administered pamidronate (90 mg, as a 2 hour intravenous infusion) monthly for 12 consecutive cycles. Bone pain, quality of life, performance status, analgesic consumption and disease staging were evaluated before and during the trial. The patients who had been administered pamidronate showed a significant decrease in bone pain (P = 0.0052). Performance status improved nearly significantly (P = 0.051), while the quality of life showed a remarkable amelioration. However, no significant decrease in analgesic consumption was recorded. Partial radiographic response of bone lesions was observed in 2/10 patients. The side effects of pamidronate were mild and transient. In conclusion, monthly infusion of pamidronate is a well-tolerated treatment that induces significant relief from bone pain and improves the quality of life of thyroid cancer patients with symptomatic and osteolytic bone metastases.

Percutaneous Ethanol Injection Efficacy in the Treatment of Large Symptomatic Thyroid Cystic Nodules: Ten-Year Follow-Up of a Large Series

We present a prospective study on the long-term efficacy of percutaneous ethanol injection (PEI) treatment of a large series of symptomatic thyroid cystic nodules (STCN). Ninety-eight patients (72 females and 26 males) were treated. The mean basal volume of the STCN was 35.3 mL. In 92 of 98 patients PEI treatment induced a greater than 50% nodule shrinkage, only 6 of 92 responder patients relapsed at a follow-up of 9 years. Moreover, all the patients had a significant clinical benefit because a significant reduction of the cyst-associated symptoms was recorded. Furthermore, a limited number of sessions was required for the treatment of cysts larger than 40 mL (mean +/- standard deviation [SD]: 2.7 +/- 0.75) demonstrating the feasibility of the procedure also in the treatment of large cysts. In conclusion, PEI is an effective and inexpensive procedure with a high patient compliance and long-lasting effects in the treatment of cysts larger than 40 mL.