Mariapia Cinelli

Cell-Surface Receptors Transactivation Mediated by G Protein-Coupled Receptors

G protein-coupled receptors (GPCRs) are seven transmembrane-spanning proteins belonging to a large family of cell-surface receptors involved in many intracellular signaling cascades. Despite GPCRs lack intrinsic tyrosine kinase activity, tyrosine phosphorylation of a tyrosine kinase receptor (RTK) occurs in response to binding of specific agonists of several such receptors, triggering intracellular mitogenic cascades. This suggests that the notion that GPCRs are associated with the regulation of post-mitotic cell functions is no longer believable. Crosstalk between GPCR and RTK may occur by different molecular mechanism such as the activation of metalloproteases, which can induce the metalloprotease-dependent release of RTK ligands, or in a ligand-independent manner involving membrane associated non-receptor tyrosine kinases, such as c-Src. Reactive oxygen species (ROS) are also implicated as signaling intermediates in RTKs transactivation. Intracellular concentration of ROS increases transiently in cells stimulated with GPCR agonists and their deliberated and regulated generation is mainly catalyzed by enzymes that belong to nicotinamide adenine dinucleotide phosphate (NADPH) oxidase family. Oxidation and/or reduction of cysteine sulfhydryl groups of phosphatases tightly controls the activity of RTKs and ROS-mediated inhibition of cellular phosphatases results in an equilibrium shift from the non-phosphorylated to the phosphorylated state of RTKs. Many GPCR agonists activate phospholipase C, which catalyze the hydrolysis of phosphatidylinositol 4,5-bis-phosphate to produce inositol 1,4,5-triphosphate and diacylglicerol. The consequent mobilization of Ca2+ from endoplasmic reticulum leads to the activation of protein kinase C (PKC) isoforms. PKCα mediates feedback inhibition of RTK transactivation during GPCR stimulation. Recent data have expanded the coverage of transactivation to include Serine/Threonine kinase receptors and Toll-like receptors. Herein, we discuss the main mechanisms of GPCR-mediated cell-surface receptors transactivation and the pathways involved in intracellular responses induced by GPCR agonists. These studies may suggest the design of novel strategies for therapeutic interventions.

Genetic mutations in the treatment of anaplastic thyroid cancer: a systematic review

BackgroundAnaplastic thyroid cancer (ATC) is a rare, lethal disease associated with a median survival of 6 months despite the best multidisciplinary care. Surgical resection is not curative in ATC patients, being often a palliative procedure. Multidisciplinary care may include surgery, loco-regional radiotherapy, and systemic therapy. Besides conventional chemotherapy, multi kinase-targeted inhibitors are emerging as novel therapeutic tools. The numerous molecular alteration detected in ATC are targets for these inhibitors. The aim of this review is to determine the prevalence of the major genetic alterations occurring in ATC and place the results in the context of the emerging kinase-targeted therapies.MethodsThe study is based on published PubMed studies addressing the prevalence of BRAF, RAS, PTEN, PI3KCA and TP53 mutations and RET rearrangements in ATC.Results21 articles dealing with 652 genetic analyses of the selected genes were used. The overall prevalence determined were the following: RET/PTC, 4%; BRAF, 23%; RAS, 60%; PTEN, 16%; PI3KCA, 24%; TP53, 48%. Genetic alterations are sometimes overlapping.ConclusionsMutations of BRAF, PTEN and PI3KCA genes are common in ATC, with RAS and TP53 being the most frequent. Given ATC genetic complexity, effective therapies may benefit from individualized therapeutic regimens in a multidisciplinary approach.

Morphological, diagnostic and surgical features of ectopic thyroid gland: A review of literature

Ectopic thyroid tissue remains a rare developmental abnormality involving defective or aberrant embryogenesis of the thyroid gland during its passage from the floor of the primitive foregut to its usual final position in pre-tracheal region of the neck. Its specific prevalence accounts about 1 case per 100.000-300.000 persons and one in 4.000-8.000 patients with thyroid disease show this condition. The cause of this defect is not fully known. Despite genetic factors have been associated with thyroid gland morphogenesis and differentiation, just recently some mutation has been associated with human thyroid ectopy. Lingual region in the most common site of thyroid ectopy but ectopic thyroid tissue were found in other head and neck locations. Nevertheless, aberrant ectopic thyroid tissue has been found in other places distant from the neck region. Ectopic tissue is affected by different pathological changes that occur in the normal eutopic thyroid. Patients may present insidiously or as an emergency. Diagnostic management of thyroid ectopy is performed by radionuclide thyroid imaging, ultrasonography, CT scan, MRI, biopsy and thyroid function tests. Asymptomatic euthyroid patients with ectopic thyroid do not usually require therapy but are kept under observation. For those with symptoms, treatment depends on size of the gland, nature of symptoms, thyroid function status and histological findings. Surgical excision is often required as treatment for this condition.

How to utilize Ca2+ signals to rejuvenate the repairative phenotype of senescent endothelial progenitor cells in elderly patients affected by cardiovascular diseases: a useful therapeutic support of surgical approach?

Endothelial dysfunction or loss is the early event that leads to a host of severe cardiovascular diseases, such as atherosclerosis, hypertension, brain stroke, myocardial infarction, and peripheral artery disease. Ageing is regarded among the most detrimental risk factor for vascular endothelium and predisposes the subject to atheroscleorosis and inflammatory states even in absence of traditional comorbid conditions. Standard treatment to restore blood perfusion through stenotic arteries are surgical or endovascular revascularization. Unfortunately, ageing patients are not the most amenable candidates for such interventions, due to high operative risk or unfavourable vascular involvement. It has recently been suggested that the transplantation of autologous bone marrow-derived endothelial progenitor cells (EPCs) might constitute an alternative and viable therapeutic option for these individuals. Albeit pre-clinical studies demonstrated the feasibility of EPC-based therapy to recapitulate the diseased vasculature of young and healthy animals, clinical studies provided less impressive results in old ischemic human patients. One hurdle associated to this kind of approach is the senescence of autologous EPCs, which are less abundant in peripheral blood and display a reduced pro-angiogenic activity. Conversely, umbilical cord blood (UCB)-derived EPCs are more suitable for cellular therapeutics due to their higher frequency and sensitivity to growth factors, such as vascular endothelial growth factor (VEGF). An increase in intracellular Ca2+ concentration is central to EPC activation by VEGF. We have recently demonstrated that the Ca2+ signalling machinery driving the oscillatory Ca2+ response to this important growth factor is different in UCB-derived EPCs as compared to their peripheral counterparts. In particular, we focussed on the so-called endothelial colony forming cells (ECFCs), which are the only EPC population belonging to the endothelial lineage and able to form capillary-like structures in vitro and stably integrate with host vasculature in vivo. The present review provides a brief description of how exploiting the Ca2+ toolkit of juvenile EPCs to restore the repairative phenotype of senescent EPCs to enhance their regenerative outcome in therapeutic settings.

Endothelial progenitor cells support tumour growth and metastatisation: implications for the resistance to anti-angiogenic therapy

Endothelial progenitor cells (EPCs) have recently been shown to promote the angiogenic switch in solid neoplasms, thereby promoting tumour growth and metastatisation. The genetic suppression of EPC mobilization from bone marrow prevents tumour development and colonization of remote organs. Therefore, it has been assumed that anti-angiogenic treatments, which target vascular endothelial growth factor (VEGF) signalling in both normal endothelial cells and EPCs, could interfere with EPC activation in cancer patients. Our recent data, however, show that VEGF fails to stimulate tumour endothelial colony-forming cells (ECFCs), i.e. the only EPC subtype truly belonging to the endothelial lineage. The present article will survey current evidence about EPC involvement in the angiogenic switch: we will focus on the controversy about EPC definition and on the debate around their actual incorporation into tumour neovessels. We will then discuss how ECFC insensitivity to VEGF stimulation in cancer patients could underpin their well-known resistance to anti-VEGF therapies.

Morphology changes in human lung epithelial cells after exposure to diesel exhaust micron sub particles (PM1.0) and pollen allergens

In the recent literature there has been an increased interest in the effects of particulate matter on the respiratory tract. The objective of this study was to use an in vitro model of type II lung epithelium (A549) to evaluate the cell ability to take up sub-micron PM(1.0) particles (PM(1.0)), Parietaria officinalis (ALL), and PM(1.0) + ALL together. Morphological analysis performed by Transmission Electron Microscope (TEM) showed that PM and ALL interacted with the cell surface, then penetrating into the cytoplasm. Each single treatment was able to point out a specific change in the morphology. The cells treated appear healthy and not apoptotic. The main effect was the increase of: multilamellar bodies, lysosomal enzymes, microvilli, and presence of vesicle/vacuoles containing particles. These observations demonstrate morphological and functional alterations related to the PM(1.0) and P. officinalis and confirm the induction of the inflammatory response in lung cells exposed to the inhalable particles.

Cytological diagnosis of thyroid nodules in Hashimoto thyroiditis in elderly patients

BackgroundLong standing Hashimoto Thyroiditis (HT) causes shrinking and atrophy of the thyroid, but may also lead to diffuse enlargement of the gland and/or formation of nodules. These nodules should be differentiated from papillary thyroid carcinoma (PTC) and primary thyroidal non-Hodgkin lymphoma (PTL), which are possible complications of HT, and require pre-surgical diagnoses and different treatments.This study focuses on the role of fine-needle cytology (FNC) in the clinical surveillance and pre-surgical diagnosis of HT with diffuse and nodular enlargement of the gland in elderly patients.MethodsThirty-four elderly patients (≥ 65 yrs) with HT and diffuse or nodular enlargement of the thyroid underwent ultrasound (US)-guided FNC. Smears were routinely stained and evaluated; additional passes were used for flow cytometry (FC) assessment of lymphoid infiltrate in 6 cases.ResultsThe cytological diagnosis was HT in 12 cases with prevalence of Hurtle cells in 2 cases, PTC in 1 case and PTL in 2 cases. FC assessed the reactive, non-lymphomatous nature of the lymphoid infiltrate in 5 cases and demonstrated light chain restriction, hence the lymphomatous nature of the lymphoid infiltrate in 2 cases of PTL.ConclusionsFNC plays a key role in the clinical surveillance and pre-surgical diagnosis of diffuse enlargement and nodular presentation of HT in elderly patients. FNC can correctly diagnose HT, PTC and PTL indicating the need for surgery and its extension in suspicious or neoplastic cases, leaving other cases to the medical treatment and clinical surveillance.

Endoplasmic Reticulum Ca2+ Handling and Apoptotic Resistance in Tumor‐Derived Endothelial Colony Forming Cells

Truly endothelial progenitor cells (EPCs) can be mobilized from bone marrow to support the vascular network of growing tumors, thereby sustaining the metastatic switch. Endothelial colony forming cells (ECFCs) are the only EPC subtype belonging to the endothelial phenotype and capable of incorporating within neovessels. The intracellular Ca2+ machinery plays a key role in ECFC activation and is remodeled in renal cellular carcinoma‐derived ECFCs (RCC‐ECFCs). Particularly, RCC‐ECFCs seems to undergo a drop in endoplasmic reticulum (ER) Ca2+ concentration ([Ca2+]ER). This feature is remarkable when considering that inositol‐1,4,5‐trisphosphate (InsP3)‐dependent ER‐to‐mitochondria Ca2+ transfer regulates the intrinsic apoptosis pathway. Herein, we sought to assess whether: (1) the [Ca2+]ER and the InsP3‐induced ER‐mitochondria Ca2+ shuttle are reduced in RCC‐ECFCs; and (2) the dysregulation of ER Ca2+ handling leads to apoptosis resistance in tumor‐derived cells. RCC‐ECFCs displayed a reduction both in [Ca2+]ER and in the InsP3‐dependent mitochondrial Ca2+ uptake, while they expressed normal levels of Bcl‐2 and Bak. The decrease in [Ca2+]ER was associated to a remarkable ER expansion in RCC‐ECFCs, which is a hallmark of ER stress, and did not depend on the remodeling of the Ca2+‐transporting and the ER Ca2+‐storing systems. As expected, RCC‐ECFCs were less sensitive to rapamycin‐ and thapsigargin‐induced apoptosis; however, buffering intracellular Ca2+ levels with BAPTA dampened apoptosis in both cell types. Finally, store‐operated Ca2+ entry was seemingly uncoupled from the apoptotic machinery in RCC‐ECFCs. Thus, the chronic underfilling of the ER Ca2+ pool could confer a survival advantage to RCC‐ECFCs and underpin RCC resistance to pharmacological treatment. J. Cell. Biochem. 117: 2260–2271, 2016.

Diagnostic utility of BRAFV600E mutation testing in thyroid nodules in elderly patients

BackgroundThyroid cancer is a rare disease characterized by the subtle appearance of a nodule. Fine-needle cytology (FNC) is the first diagnostic procedure used to distinguish a benign from a malignant nodule. However, FNC yields inconclusive results in about 20% of cases. BRAFV600E mutation is the most frequent genetic alteration in papillary thyroid carcinoma (PTC); its high prevalence makes this oncogene a useful marker to refine inconclusive FNC results. However, the prevalence of the BRAFV600E mutation depends on detection methods, geographical factors, and age. The aim of this study is to determine the prevalence of BRAFV600E mutation and its utility as a diagnostic tool in elderly subjects.MethodsFNC from 92 PTC patients were subjected to the analysis of BRAF mutation by pyrosequencing and direct sequencing; age-dependent prevalence was also determined.ResultsBRAF mutation analysis was successful in all FNC specimens. BRAFV600E was documented in 62 (67.4%) and in 58 (63.0%) PTCs by pyrosequencing and direct sequencing, respectively. BRAFV600E prevalence did not correlate with patients age at diagnosis. Twenty out of 32 PTCs (62.5%) were correctly diagnosed by BRAF mutation analysis in inconclusive FNC results.ConclusionsDetection of BRAFV600E in cytology specimens by pyrosequencing is a useful diagnostic adjunctive tool in the evaluation of thyroid nodules also in elderly subjects.

Primary giant hepatic neuroendocrine carcinoma: A case report

Carcinoid tumours arise from neuroendocrine cells and may develop in almost any organ. These type of tumours actually are correctly termed neuroendocrine tumours. Hepatic neuroendocrine carcinomas rarely arise as primary tumour; in fact on 100 cases reported in literature just a few of these are of primary nature. We report the case of a giant hepatic neuroendocrine carcinoma in a 55-year-old man. The symptoms were only recurrent hypoglycemia and an abdominal mass. Diagnosis was performed by blood analysis, ultrasonography, TC scan and In111-DTPA-octreotide scan. Surgical treatment occurred by an en bloc removal of the mass and a wide resection with free margins. Histological examination confirmed diagnosis. Clinical and instrumental diagnostic follow-up show the patient still alive, in very good conditions and disease free two years after surgery.