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Background: Solid-pseudopapillary neoplasms of the pancreas (SPNs) are uncommon tumours usually frequent in young women. Although the pathogenesis of SPNs is uncertain a potential influence of the sex hormone milieu on the biology of these tumours has been suggested. The controversial expression of oestrogen receptors (ERs) in SPNs, provide a rationale for studying the effects of oestrogenic molecules on SPN development. Methods: The expression of a large series of hormonal ligands and receptors was evaluated in tissue specimens and in a primary cell culture (SPNC), obtained from a SPN in young female patient. The effects of 17β-oestradiol (17βE2), ICI 182,780 and tamoxifen (Tam) on cell replication and growth were examined. Results: We have established SPNC primary line. Immunocytochemical analysis was positive for vimentin, cyclin D1 and β-catenin and negative for cytokeratin, CD10 and neuroendocrine markers, in line with the immunostaining features of the tumoral tissue. Expression of ERα, ERβ and progesterone mRNAs was demonstrated in SPNC and tumor tissue. A proliferative and antiproliferative action of 17βE2 and Tam respectively were proved in SPNC. Conclusion: In conclusion, we provide the first direct evidence that oestrogenic molecules can influence proliferation of SPNC, offering future strategies in the control of this neoplasia via selective ER modulators. [ABSTRACT FROM AUTHOR]

Abstract: Long-term stability of arthroplasty prosthesis depends on the integration between the bone tissue and the implanted biomaterials, which requires the contribution of osteoblastic precursors and their continuous differentiation into the osteoblastic phenotype. Classically, these interactions are tested in vitro using mesenchymal stem cells (MSCs) isolated and ex vivo expanded from bone marrow aspirates. Human adipose tissue-derived stromal cells (AMSCs) may be a more convenient source of MSCs, according to their abundance and accessibility, but no data are available on their in vitro interactions with hard biomaterials. The aim of this work is to compare the osteogenic potential of human AMSCs and bone marrow-derived MSCs (BMMSCs) and to evaluate their response to Ti6Al4V alloy in terms of adhesion, proliferation and differentiation features, using the human osteosarcoma cell line SaOS-2 for comparison. The overall results showed that AMSCs have the same ability to produce bone matrix as BMMSCs and that Ti6Al4V surfaces exhibit an osteoinductive action on AMSCs, promoting their differentiation into functional osteoblasts and increasing bone formation. In conclusion, adipose tissue is a promising autologous source of osteoblastic cells with important clinical implications for bone tissue engineering. [Copyright &y& Elsevier]

MicroRNAs (miRNAs) are post-transcriptional regulators of gene expression, interplaying with transcription factors in complex regulatory networks. Menin is the product of the MEN1 oncosuppressor gene, responsible for multiple endocrine neoplasia type 1 syndrome. Recent data suggest that menin functions as a general regulator of transcription. Menin expression modulates mesenchymal cell commitment to the myogenic or osteogenic lineages. The microRNA 26a (miR-26a) modulates the expression of SMAD1 protein during the osteoblastic differentiation of human adipose tissue-derived stem cells (hADSCs). We used siRNA silencing against MEN1 mRNA and pre-miR-26 mimics to study the interplay between them and to investigate the interplay between menin and miR-26a as regulators of osteogenic differentiation in the hADSCs. We found that in hADSCs the siRNA-induced silencing of MEN1 mRNA resulted in a down regulation of miR-26a, with a consequent upregulation of SMAD1 protein. Chromatin immunoprecipitation (ChIP) showed that menin occupies the miR-26-a gene promoter, thus inducing its expression and confirming that menin is a positive regulator of miR-26a. In conclusion, results from this study evidenced, for the first time, a direct interaction between menin transcription factor and miRNA, interaction that seems to play a pivotal role during the hADSCs osteogenesis, thus suggesting a novel target for bone disease RNA-based therapy. [ABSTRACT FROM AUTHOR]

Bone tissue engineering and nanotechnology enable the design of suitable substitutes to restore and maintain the function of human bone tissues in complex fractures and other large skeletal defects. Long-term stability and functionality of prostheses depend on integration between bone cells and biocompatible implants. Human adipose tissue-derived mesenchymal stem cells (hAMSCs) have been shown to possess the same ability to differentiate into osteoblasts and to produce bone matrix of classical bone marrow derived stem cells (BMMSCs). Ti6A14V and Ti13Nb13Zr are two different biocompatible titanium alloys suitable for medical bone transplantation. Preliminary results from our Research Group demonstrated that smooth Ti6Al4V surfaces exhibit an osteoconductive action on hAMSCs, granting their differentiation into functional osteoblasts and sustaining bone matrix synthesis and calcification. The purpose of this study is to assay the ability of nanostructured Ti6Al4V and Ti13Nb13Zr alloys to preserve the growth and adhesion of hAMSCs and, mostly, to sustain and maintain their osteogenic differentiation and osteoblast activity. The overall results showed that both nanostructured titanium alloys are capable of sustaining cell adhesion and proliferation, to promote their differentiation into osteoblast lineage, and to support the activity of mature osteoblasts in terms of calcium deposition and bone extracellular matrix protein production. [ABSTRACT FROM AUTHOR]

Multiple Endocrine Neoplasia Type 2 (MEN2) is a rare hereditary complex disorder characterized by the presence of medullary thyroid carcinoma (MTC), unilateral or bilateral pheochromocytoma (PHEO) and other hyperplasia and/or neoplasia of different endocrine tissues within a single patient. MEN2 has been reported in approximately 500 to 1000 families worldwide and the prevalence has been estimated at approximately 1:30,000. Two different forms, sporadic and familial, have been described for MEN2. Sporadic form is represented by a case with two of the principal MEN2-related endocrine tumors. The familial form, which is more frequent and with an autosomal pattern of inheritance, consists of a MEN2 case with at least one first degree relative showing one of the characteristic endocrine tumors. Familial medullary thyroid carcinoma (FMTC) is a subtype of MEN2 in which the affected individuals develop only medullary thyroid carcinoma, without other clinical manifestations of MEN2. Predisposition to MEN2 is caused by germline activating mutations of the c-RET proto-oncogene on chromosome 10q11.2. The RET gene encodes a single-pass transmembrane tyrosine kinase that is the receptor for glial-derived neurotrophic growth factors. The combination of clinical and genetic investigations, together with the improved understanding of the molecular and clinical genetics of the syndrome, helps the diagnosis and treatment of patients. Currently, DNA testing makes possible the early detection of asymptomatic gene carriers, allowing to identify and treat the neoplastic lesions at an earlier stage. In particular, the identification of a strong genotype-phenotype correlation in MEN2 syndrome may enable a more individualized treatment for the patients, improving their quality of life. At present, surgical treatment offers the only chance of cure and therefore, early clinical and genetic detection and prophylactic surgery in subjects at risk are the main therapeutic goal. [ABSTRACT FROM AUTHOR]