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Rozzano, Italy

Grosjean F.,University of Lausanne | Nasi S.,University of Lausanne | Schneider P.,University of Lausanne | Chobaz V.,University of Lausanne | And 9 more authors.
PLoS ONE | Year: 2015

Langerhans cell histiocytosis (LCH) is a rare disease caused by the clonal accumulation of dendritic Langerhans cells, which is often accompanied by osteolytic lesions. It has been reported that osteoclast-like cells play a major role in the pathogenic bone destruction seen in patients with LCH and these cells are postulated to originate from the fusion of DCs. However, due to the lack of reliable animal models the pathogenesis of LCH is still poorly understood. In this study, we have established a mouse model of histiocytosis-recapitulating human disease for osteolytic lesions seen in LCH patients. At 12 weeks after birth, severe bone lesions were observed in our multisystem histiocytosis (Mushi) model, when CD8á conventional dendritic cells (DCs) are transformed (MuTuDC) and accumulate. Most importantly, our study demonstrates that bone loss in LCH can be accounted for the transdifferentiation of MuTuDCs into functional osteoclasts both in vivo and in vitro. Moreover, we have shown that injected MuTuDCs reverse the osteopetrotic phenotype of oc/oc mice in vivo. In conclusion, our results support a crucial role of DCs in bone lesions in histiocytosis patients. Furthermore, our new model of LCH based on adoptive transfer of MuTuDC lines, leading to bone lesions within 1-2 weeks, will be an important tool for investigating the pathophysiology of this disease and ultimately for evaluating the potential of anti-resorptive drugs for the treatment of bone lesions. Copyright: © 2015 Grosjean et al.

Garcia-Manteiga J.M.,San Raffaele Scientific Institute | Bonfiglio S.,San Raffaele Scientific Institute | Malosio M.L.,CNR Institute of Neuroscience | Malosio M.L.,Humanitas Research Center | And 5 more authors.
BioMed Research International | Year: 2015

Cell epigenomics depends on the marks released by transcription factors operating via the assembly of complexes that induce focal changes of DNA and histone structure. Among these factors is REST, a repressor that, via its strong decrease, governs both neuronal and neural cell differentiation and specificity. REST operation on thousands of possible genes can occur directly or via indirect mechanisms including repression of other factors. In previous studies of gene down- and upregulation, processes had been only partially investigated in neural cells. PC12 are well-known neural cells sharing properties with neurons. In the widely used PC12 populations, low-REST cells coexist with few, spontaneous high-REST PC12 cells. High- and low-REST PC12 clones were employed to investigate the role and the mechanisms of the repressor action. Among 15,500 expressed genes we identified 1,770 target and nontarget, REST-dependent genes. Functionally, these genes were found to operate in many pathways, from synaptic function to extracellular matrix. Mechanistically, downregulated genes were predominantly repressed directly by REST; upregulated genes were mostly governed indirectly. Among other factors, Polycomb complexes cooperated with REST for downregulation, and Smad3 and Myod1 participated in upregulation. In conclusion, we have highlighted that PC12 clones are a useful model to investigate REST, opening opportunities to development of epigenomic investigation. © 2015 Jose M. Garcia-Manteiga et al.

Peverelli E.,University of Milan | Giardino E.,University of Milan | Vitali E.,Humanitas Research Center | Treppiedi D.,University of Milan | And 2 more authors.
Hormone and Metabolic Research | Year: 2014

Molecular mechanisms underlying resistance of pituitary tumors to somatostatin (SS) and dopamine (DA) analogues treatment are not completely understood. Resistance has been associated with defective expression of functional somatostatin and dopamine receptors SSTR2, SSTR5, and DRD2, respectively. Recently, a role of cytoskeleton protein filamin A (FLNA) in DRD2 and SSTR receptors expression and signaling in PRL- and GH-secreting tumors, respectively, has been demonstrated, first revealing a link between FLNA expression and responsiveness of pituitary tumors to pharmacological therapy. No molecular events underlying the reduction of FLNA levels in resistant tumors have been so far identified. FLNA can be phosphorylated by PKA on Ser2152, with increased FLNA resistance to cleavage by calpain and conformational changes affecting FLNA regions involved in SSTR2 and DRD2 binding and signal transduction. In this respect, the effect of cAMP/PKA pathway in the regulation of FLNA stability and/or function by modulating its phosphorylation status could assume particular importance in pituitary, where cAMP cascade plays a crucial role in pituitary cell functions and tumorigenesis. This review will discuss the role of FLNA in the regulation of the main GPCRs target of pharmacological treatment of pituitary tumors, that is, SSTR2 and DRD2, focusing on the effects of cAMP/PKA-mediated FLNA phosphorylation on FLNA biological functions. © Georg Thieme Verlag K.G. Stuttgart.

Colombo P.,University of Milan | Smith S.C.,VCU Health System | Massa S.,University of Milan | Renne S.L.,University of Milan | And 5 more authors.
Urology Case Reports | Year: 2015

Medullary carcinoma is a rare malignant tumor of the kidney. It affects individuals of African descent and all cases reported show evidence of sickle cell trait. We reviewed an unusual carcinoma arising in a white man, the ninth in the literature. The tumor demonstrated features associated with renal medullary carcinoma, or unclassified renal cell carcinoma, medullary phenotype as recently described; the presence of sickle cell trait confirmed the diagnosis of medullary carcinoma. This case is helpful in the differential diagnosis with non-sickle cell associated "renal cell carcinoma, unclassified with medullary phenotype," and study of this spectrum of tumors is ongoing. © 2015 The Authors.

Infante M.,Humanitas Research Hospital | Infante M.,University of Milan | Allavena P.,Humanitas Research Center | Garlanda C.,Humanitas Research Center | And 18 more authors.
International Journal of Cancer | Year: 2016

There is a well-established link between inflammation and cancer of various organs, but little data are available on inflammation-associated markers of diagnostic and prognostic clinical utility in pulmonary malignancy. Blood samples were prospectively collected from 75 resectable lung cancer patients before surgery and in a cohort of 1,358 high-risk subjects. Serum levels of long pentraxin 3 (PTX3) were determined by high-sensitivity ELISA. PTX3 immunostaining was evaluated by immunohistochemistry in cancer tissue. Serum PTX3 levels in the high-risk population were not predictive of developing subsequent lung cancer or any other malignancy; however, serum PTX3 values in patients with lung cancer were significantly higher compared with cancer-free heavy smokers. With a cutoff of 4.5 ng/ml, specificity was 0.80, sensitivity 0.69, positive predictive value 0.15 and negative predictive value 0.98. The receiver operating curve (ROC) for serum PTX3 had an area under the curve (AUC) of 83.52%. Preoperative serum PTX3 levels in lung cancer patients did not correlate with patient outcome, but high interstitial expression of PTX3 in resected tumor specimens was a significant independent prognostic factor associated with shorter survival (p < 0.001). These results support the potential of serum PTX3 as a lung cancer biomarker in high-risk subjects. Furthermore, PTX3 immunohistochemistry findings support the role of local inflammatory mechanisms in determining clinical outcome and suggest that local expression of PTX3 may be of prognostic utility in lung cancer patients. What's new? To examine the relationship between cancer and inflammation, the authors measured serum levels of pentraxin 3, a "cousin" of C-reactive protein, in patients with non-small cell lung cancer. Levels were significantly higher in patients as compared to high-risk cancer-free controls, supporting a role for pentraxin 3 as biomarker in lung cancer. Although serum levels did not correlate with clinical outcome, immunostaining of the inflammatory mediator in lung tissue was associated with shorter patient survival, underscoring the pathogenetic relevance of local inflammation in such disease. © 2015 UICC.

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