Tullio Barni

Identification of H ferritin-dependent and independent genes in K562 differentiating cells by targeted gene silencing and expression profiling

Ferritin is best known as the key molecule in intracellular iron storage, and is involved in several metabolic processes such as cell proliferation, differentiation and neoplastic transformation. We have recently demonstrated that the shRNA silencing of the ferritin heavy subunit (FHC) in a melanoma cell line is accompanied by a consistent modification of gene expression pattern leading to a reduced potential in terms of proliferation, invasiveness, and adhesion ability of the silenced cells. In this study we sought to define the repertoire of genes whose expression might be affected by FHC during the hemin-induced differentiation of the erythromyeloid cell line K562. To this aim, gene expression profiling was performed in four different sets of cells: i) wild type K562; ii) sh-RNA FHC-silenced K562; iii) hemin-treated wild-type K562; and iv) hemin-treated FHC-silenced K562. Statistical analysis of the gene expression data, performed by two-factor ANOVA, identified three distinct classes of transcripts: a) Class 1, including 657 mRNAs whose expression is modified exclusively during hemin-induced differentiation of K562 cells, independently from the FHC relative amounts; b) Class 2, containing a set of 70 mRNAs which are consistently modified by hemin and FHC-silencing; and c) Class 3, including 128 transcripts modified by FHC-silencing but not by hemin. Our data indicate that FHC may function as a modulator of gene expression during erythroid differentiation and add new findings to the knowledge of the complex gene network modulated during erythroid differentiation.

A reappraisal of macrophage polarization in glioblastoma: Histopathological and immunohistochemical findings and review of the literature

The survival rate in glioblastoma multiforme patients has scarcely improved in the last decades; however, many new therapeutic strategies have been theorized or developed for these neoplasias. Recently, the inverse correlation observed between patient prognosis and tumor-associated macrophages (TAMs) density in solid tumors has encouraged the development of anti-tumor strategies aiming to target TAMs. As expected, TAMs polarization is influenced by both macrophage localization and tumor microenvironment signals, resulting in a more complex scenario than the simple M1/M2 activation status. Macrophage polarization in glioblastoma has not yet been fully elucidated, and most results have been obtained in experimental non-human settings, with some apparent contradiction. The authors performed a histopathological and immunohistochemical study of 37 cases of glioblastoma in order to characterize the M1 and M2 macrophage populations within TAMs. A high prevalence of CD163+ M2-polarized macrophages was detected in this cohort, whereas iNOS+ macrophages were rarely found. The down-regulation of CD68 expression in microglia/macrophage infiltrating glioblastomas is also reported for the first time. Such a finding is associated with a specific location of TAMs within the lesion, as confirmed by the fact that CD68 staining was lower than CD163, mainly in perivascular areas. The authors discuss the recent literature about the global scenario of macrophage plasticity and polarization in glioblastoma, and suggest some pivotal points for therapeutic applications.

Elastofibroma Dorsi: A Histochemical and Immunohistochemical Study

Elastofibroma dorsi (ED) is considered a member of a heterogeneous group of benign fibrous (fibroblastic or myofibroblastic) softtissue tumors, frequently localized in the periscapular region in middle aged or older individuals. However, the pathogenesis of ED is still unclear and many authors believe that ED results from a reactive hyperproliferation of fibroblastic tissue, while others suggest that it may be a consequence of a mechanical friction. In our study, we examined 11 cases of ED using histochemical and immunohistochemical methods, in order to extend the knowledge about extracellular matrix composition and histopathogenesis of ED. From the results it appeared that stroma and interspersed spindle cells of ED were positive for both periostin and tenascin-C. Mast cells tryptase-positive were also abundant throughout the lesion. The perivascular distribution of periostin and tenascin-C, associated with the CD34 positivity, suggest that endothelial-mesenchymal transition events can account for neovascularization and production of fibroelastic tissue characteristic of elastofibroma. Our data obtained in endothelial cells cultures demonstrated that elastin production is higher when the status of confluence of the cells is low. So, we can assume that such a phenomenon is a characteristic of mesenchymal/endothelial cells CD34 positive, in which elastin production results to be inversely proportional to the vascular differentiation of cellular elements. In the light of these considerations, we think that a cancerous nature of ED is unlikely. Overall, our study report, for the first time, a detailed description of extracellular matrix composition in ED, suggesting that a mechanical strain-dependent reactivation of periostin and tenascin-C expression, as well as of elastin deposition, could be responsible for development of ED.

H ferritin gene silencing in a human metastatic melanoma cell line: a proteomic analysis.

Ferritin, the major intracellular iron-storage protein, is made of 24 subunits of two types, H and L. Besides regulating intracellular iron homeostasis, it has been found that ferritin, in particular the H subunit (FHC), is involved in different biological events such as cell differentiation and pathologic states (i.e., neurodegeneration and cancer). This study is aimed at investigating the whole-cell proteome of FHC-expressing and sh-RNA-silenced human metastatic melanoma cells (MM07(m)) in the attempt to identify and classify the highest number of proteins directly or indirectly controlled by the FHC. We identified about 200 differentially expressed proteins and classified them in clusters on the basis of their functions, as proteins involved in metabolic processes, cell adhesion, migration, and proliferation processes. Some of them have captured our attention because of their involvement in metabolic pathways related to tumor progression and metastasis. In vitro assays confirmed that the FHC-silenced MM07(m) cells are characterized by a decreased growth activity, a reduced invasiveness, and a reduced cell adhesion capability. Moreover, nude mice (CD1 nu/nu), subcutaneously injected with FHC-silenced MM07(m) cells, showed a remarkable 4-fold reduction of their tumor growth capacity compared to those who received the FHC-unsilenced MM07(m) counterpart. In conclusion, these data indicate that gene silencing technology, coupled to proteomic analysis, is a powerful tool for a better understanding of H ferritin signaling pathways and lend support to the hypothesis that specific targeting of this gene might be an attractive and potentially effective strategy for the management of metastatic melanoma.

Negative transcriptional regulation of the human periostin gene by YingYang-1 transcription factor.

Periostin (POSTN), an osteoblast-specific secreted protein known to be associated with cell adhesion activity for bone formation and development by the epithelial cell-derived tumors, leads to a significant enhancement in angiogenesis and tumorigenesis. At present, little is known about the mechanisms underlying its transcriptional control either in physiological or neoplastic conditions. In this study we demonstrate that the ability of the human POSTN promoter to drive transcription mostly depends on the activity of YingYang-1 (YY1) zinc finger transcription factor. YY1, whose regulatory role in biology includes, besides transcriptional control, also chromatin remodeling, DNA damage repair and tumorigenesis, acts as a strong negative modulator of the POSTN expression. We retain that the identification of the functional role of YY1 in the transcriptional control of the human POSTN gene adds new insights in the studies focused on gene expression in normal and transformed cells.

Innate immunity in cutaneous melanoma

The skin immune system is composed of a vast network of immune cells, including lymphocytes, macrophages, neutrophils, dendritic cells and Langerhans cells, which not only are involved in inflammatory responses but also contribute to homeostatic function and may participate in the various steps of carcinogenesis. Many studies support the notion that innate immunity has a key role in the development, growth and prognosis of cutaneous malignant melanoma (MM), through the release of pro‐ and/or anti‐inflammatory cytokines and tumour growth factors. The tumour environment in a major subset of cutaneous MM shows evidence of a T cell‐infiltrated phenotype, but there is less known about the presence and the phenotype of other immune system cells. Response to immunotherapy is largely correlated with the presence of T cells in the tumour microenvironment, while the regulation exerted by stromal components such as macrophages and mast cells has been less investigated. In the current report, we review the recent literature, focusing our attention on the role of macrophages, dendritic cells, mast cells and natural killer cells in orchestrating MM progression, to better understand tumour immunobiology. The identification of new therapeutic targets and the application of approaches aimed at modulating crosstalk between immune and tumour cells, could have a crucial impact on immunotherapy and result in better clinical outcome. We hope this review will be helpful in cutaneous MM research.

Reduced learning and memory performances in high-fat treated hamsters related to brain neurotensin receptor1 expression variations

HighlightsHigh fat diet modifies NOR (recognition) and CPP (reward) performances.Feeding behaviors and body weight alterations in hyperlipidemic hamsters.Elevated lipid and glucose blood levels were caused by high fat diet.Neurotensin receptor expression variations in limbic areas due to high fat diet. ABSTRACT Recent indications are suggesting that high fat and sugar‐enriched foods do not only evoke harmful physiological conditions, but they also endure evident structural alterations in cerebral regions controlling cognitive and feeding behaviors. Food consumption plus neuronal energy regulatory mechanisms seem to constitute a complex system assuring that food calories do not exceed body requirements. At the same time obesogenic‐related properties of limbic feeding stations like the hypothalamus (HTH), hippocampus (HIP) and amygdala (AMY) tend to control eating habits through the interaction of distinct neuropeptides. For this purpose, it was our intention to correlate expression differences of a key anti‐obesogenic neuropeptide receptor i.e. neurotensin1 (NTR1) on mnemonic performances in the hibernating hamster (Mesocricetus auratus) exposed to a high fat diet (HFD). Interestingly, these hamsters exhibited a notable enhanced (p < 0.01) body weight from the fifth on to the twelfth week of treatment, which was accompanied by elevated blood lipid cholesterolo and triglycerides and glucose levels. At the same time these hamsters provided diminished locomotor activities such as exploratory bouts, rearing and grooming behaviors. Of greater relevance was their very extreme (p < 0.001) inability of identifying new objects during novel object recognition (NOR) tests along with not having correctly chosen the chamber of the conditioned place preference (CPP) apparatus, which contained the gratifying reward. Surprisingly the altered behavioral plus mnemonic tasks of HFD hamsters were tightly related to elevated NTR1 expression changes in the above limbic sites thus proposing this neuronal system as a highly probable alternative for treating obesity‐dependent mnemonic dysfunctions.

Role of Brain Neuroinflammatory Factors on Hypertension in the Spontaneously Hypertensive Rat

It is already widely known that the different brain areas involved in blood pressure control, are highly vulnerable to the deleterious effects of this condition. Of particular concern are hypertensive and neuroinflammatory-dependent injuries that by modifying blood flow account for artery structural and functional alterations. It was thus our intention to establish if expression changes of some key brain neuroinflammatory factors like caspase-1,3, NF-kB, IL-1β and NLRP3, which are known to control blood pressure, are actively involved with inflammation regulatory events in a highly valuable spontaneously hypertensive rat (SHR) model. Indeed, notably increased (p < 0.001) caspase-1, NLRP3 and IL-1β mRNA levels were detected in amygdalar plus hypothalamic areas of SHR. Contextually, similar up-regulated levels of these factors were also reported in brainstem nuclei with respect to the few hippocampal areas. This trend was supported by moderate increases (p < 0.05) of NLRP3 in amygdalar and brainstem sites, while notably greater expression differences of NF-kB protein were observed in hippocampal and hypothalamic areas of SHR. At the same time, moderately increased levels of iNOS were typical of all of the above brain areas with the exception of the consistently (p < 0.01) increased levels featured in the brainstem. Moreover, even immunohistochemical evaluations supplied notably and moderately increased cleaved caspase-3 cell levels in hippocampus and hypothalamus areas, respectively. Overall, evident hypertensive bouts correlated to neuroinflammatory events, especially in brain areas controlling blood pressure, tend to underlie the value of novel therapeutic approaches designed to improve brain blood flow and subsequently reduce hypertensive-dependent cerebral complications.

Innate immunity in cardiac myxomas and its pathological and clinical correlations

Cardiac myxomas are the most common benign cardiac tumor. We investigated the immunohistochemical properties of 11 surgically excised cardiac myxomas, in order to analyze the correlation between macrophages and mast cell populations and clinical parameters. CD68+/CD163−/iNOS− (M0) cells represent the most abundant macrophage phenotype; however, CD68+/CD163+ cells (M2) were also frequent. CD68+/iNOS+ (M1) elements were rare. Mast cells, defined as a population of c-kit (CD117)+ and/or tryptase+ cells were also detected. Statistical analysis showed significant correlations between c-kit (CD117)+ and tryptase, CD68 and erythrocyte sedimentation rate (ESR), ESR and red blood cell count (RBC), and prothrombin time and platelet count. The inverse correlation between RBCs in peripheral blood and ESR suggested that anemia associated with chronic inflammatory disease is a noncasual event in patients suffering from cardiac myxoma. Mechanical hemolysis may be only a minor component of anemia, according to the lack of correlation between echographic surface and RBCs. Moreover, tumor size did not correlate with ESR, showing that inflammatory state may depend from both tumor cells population and inflammatory infiltrate. In the future, modulation of macrophage polarization in cardiac myxomas might represent important therapeutic target.

Extravascular type of intravascular papillary endothelial hyperplasia mimicking parotid gland neoplasia and the possible role of ferritin in the pathogenesis: A case report

Intravascular papillary endothelial hyperplasia (IPEH) is defined as a vascular lesion characterized by extensive proliferation of vascular endothelial cells. This lesion was first described by Pierre Masson in 1923 as intravascular hemangioendothelioma. The most frequent sites of involvement are the skin and subcutis. IPEH comprises ~2% of the vascular tumors of the skin and subcutaneous tissue and it has a predilection for the head, neck, trunk and the extremities. The diagnosis is based on histopathology. We herein present the second case of Massons tumor of the parotid gland described in literature. The patient was a 70-year-old female. Magnetic resonance imaging revealed an irregular lesion with smooth margins, initially considered to be compatible with pleomorphic adenoma. Immunohistochemical analysis revealed positivity of the tumor cells for ferritin heavy and light chains, vimentin and CD31. The aim of the present study was to emphasize the immunohistochemical characteristics and briefly discuss the potential role of ferritin in the pathogenesis of IPEH.