).q RSNA, 2014 Purpose:To evaluate the diagnostic accuracy of unenhanced and quantitative contrast-enhanced ultrasonography (US) in the differential diagnosis of small nonpalpable testicular lesions. Materials andMethods:The local review board approved the protocol, and all patients provided written informed consent. One hundred fifteen patients (median age, 34 years; age range, 14-61 years) with nonpalpable testicular lesions were consecutively enrolled between 2006 and 2012 and underwent unenhanced scrotal US, contrast-enhanced US, surgical enucleation, and at least 18 months of follow-up. Clinical and histologic features were recorded, and qualitative and quantitative analysis of contrast-enhanced US time-intensity curves were performed. Logistic regression analysis was performed to explore features of malignancy. Receiver operating characteristic (ROC) curves were developed for cumulative unenhanced and contrast-enhanced US scores. Results:All lesions were 1.5 cm or smaller. Forty-four of the 115 patients (38%) had malignant tumors, 42 had benign tumors (37%), and 29 (25%) had nonneoplastic lesions. Conclusion:Benign testicular tumors are frequent incidental findings. Quantitative scrotal contrast-enhanced US is a noninvasive diagnostic tool that could improve the differential diagnosis and individualized management of small testicular lesions.q RSNA, 2014

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive neoplastic disease. Gemcitabine, the currently used chemotherapeutic drug for PDAC, elicits only minor benefits, because of the development of escape pathways leading to chemoresistance. Herein, we aimed at investigating the involvement of the mitogen activating protein kinase interacting kinase (MNK)/eIF4E pathway in the acquired drug resistance of PDAC cells. Screening of a cohort of PDAC patients by immunohistochemistry showed that eIF4E phosphorylation correlated with disease grade, early onset of disease and worse prognosis. In PDAC cell lines, chemotherapeutic drugs induced MNK-dependent phosphorylation of eIF4E. Importantly, pharmacological inhibition of MNK activity synergistically enhanced the cytostatic effect of gemcitabine, by promoting apoptosis. RNA interference (RNAi) experiments indicated that MNK2 is mainly responsible for eIF4E phosphorylation and gemcitabine resistance in PDAC cells. Furthermore, we found that gemcitabine induced the expression of the oncogenic splicing factor SRSF1 and splicing of MNK2b, a splice variant that overrides upstream regulatory pathways and confers increased resistance to the drug. Silencing of SRSF1 by RNAi abolished this splicing event and recapitulated the effects of MNK pharmacological or genetic inhibition on eIF4E phosphorylation and apoptosis in gemcitabinetreated cells. Our results highlight a novel pro-survival pathway triggered by gemcitabine in PDAC cells, which leads to MNK2-dependent phosphorylation of eIF4E, suggesting that the MNK/eIF4E pathway represents an escape route utilized by PDAC cells to withstand chemotherapeutic treatments.

Background Type-2 diabetes and obesity independently increases the risk of heart failure via incompletely understood mechanisms. We propose that hyperinsulinemia might promote adverse consequences in hearts of subjects with type-2 diabetes and obesity. Methods High fat diet feeding was used to induce obesity and diabetes in wild type mice or mice lacking β2-adrenergic receptor (β2AR) or β-arrestin2. Wild type mice fed with high fat diet were treated with β-blocker carvedilol or G-protein receptor kinase 2 (GRK2) inhibitor. We examined the signaling and cardiac contractile function. Results High fat diet feeding selectively increases the expression of phosphodiesterase 4D (PDE4D) in mouse hearts, in concert with reduced PKA phosphorylation of phospholamban, which contributes to systolic and diastolic dysfunction. The expression of PDE4D is also elevated in human hearts with diabetes. The induction of PDE4D expression is mediated by an insulin receptor, insulin receptor substrate, and (GRK2) and β-arrestin2-dependent transactivation of a β2AR-ERK signaling cascade. Thus pharmacological inhibition of β2AR or GRK2, or genetic deletion of β2AR or β-arrestin2, all significantly attenuate insulin-induced phosphorylation of ERK and PDE4D induction, to prevent diabetes-related contractile dysfunction. Conclusions These studies elucidate a novel mechanism by which hyperinsulinemia contributes to heart failure by increasing PDE4D expression and identify β2AR or GRK2 as plausible therapeutic targets for preventing or treating heart failure in subjects with type-2 diabetes.

Stra8 (stimulated by retinoic acid 8) encodes a protein crucial for mammalian germ cells entering into premeiotic stages. Here, to elucidate the still unknown STRA8 molecular functions, we studied the cellular localization of the protein in several cell types, including premeiotic mouse germ cells and stem cell lines. We reported distinct STRA8 localization in germ and stem cell types and a heterogeneous protein distribution in the cytoplasm and nucleus of such cells suggesting that the protein can shuttle between these two compartments. Moreover, we identified specific protein motifs determining its nuclear import/export. Furthermore, we demonstrated that in transfected cell lines the nuclear import of STRA8 is an active process depending on an N-terminal basic nuclear localization signal. Moreover, its nuclear export is mainly mediated by the Exportin1 (XPO1) recognition of a nuclear export signal. Significantly, we also demonstrated that STRA8 associates with DNA and possesses transcriptional activity. These observations strongly suggest that STRA8 can exert important functions in the nucleus rather than in the cytoplasm as believed previously, likely depending on the cell type and regulated by its nuclear-cytoplasmic shuttling.

Introduction: The role of nutraceuticals in the treatment of male infertility, especially in the “idiopathic form”, remains the subject of significant debate. Many antioxidants improve sperm motility but the exact mechanism by which they act is still unclear. Although several studies have shown a correlation between sperm motility and mitochondrial function, the effects of antioxidant therapy on mitochondrial membrane potential (MMP) are poorly studied. The first aim of this review was to evaluate the efficacy of antioxidants on mitochondrial function and, consequently, on sperm motility in male infertile patients. Material and Methods: we performed a systematic search of all randomized controlled and uncontrolled studies available in the literature that reported sperm motility and MMP at baseline and after antioxidant administration in-vivo and in-vitro in patients with idiopathic asthenozoospermia. Pubmed, MEDLINE, Cochrane, Academic One Files, Google Scholar and Scopus databases were used. Results: Unexpectedly, among 353 articles retrieved, only one study met our inclusion criteria and showed a significant effect of myoinositol on both MMP and sperm motility. We then summarized the main knowledge on anatomy and metabolism of sperm mitochondria, techniques allowing to assess sperm mitochondria function and its relationships with low sperm motility. Finally, we paid special attention to the effect of antioxidant/prokinetic molecules for the treatment of asthenozoospermia. Conclusions: This is the first systematic review that has attempted to evaluate the effects of antioxidants on MMP and sperm motility. Although results are not conclusive due to the dearth of studies, the close relationship between mitochondria and sperm motility is clear. The investigation of this correlation could provide valuable information to be exploited in clinical practice for the treatment of male infertility.

NEK2 is a serine/threonine kinase that promotes centrosome splitting and ensures correct chromosome segregation during the G2/M phase of the cell cycle, through phosphorylation of specific substrates. Aberrant expression and activity of NEK2 in cancer cells lead to dysregulation of the centrosome cycle and aneuploidy. Thus, a tight regulation of NEK2 function is needed during cell cycle progression. In this study, we found that NEK2 localizes in the nucleus of cancer cells derived from several tissues. In particular, NEK2 co-localizes in splicing speckles with SRSF1 and SRSF2. Moreover, NEK2 interacts with several splicing factors and phosphorylates some of them, including the oncogenic SRSF1 protein. Overexpression of NEK2 induces phosphorylation of endogenous SR proteins and affects the splicing activity of SRSF1 toward reporter minigenes and endogenous targets, independently of SRPK1. Conversely, knockdown of NEK2, like that of SRSF1, induces expression of pro-apoptotic variants from SRSF1-target genes and sensitizes cells to apoptosis. Our results identify NEK2 as a novel splicing factor kinase and suggest that part of its oncogenic activity may be ascribed to its ability to modulate alternative splicing, a key step in gene expression regulation that is frequently altered in cancer cells.

PATZ1 is a recently discovered zinc finger protein that, due to the presence of the POZ domain, acts as a transcriptional repressor affecting the basal activity of different promoters. To gain insights into its biological role, we generated mice lacking the PATZ1 gene. Male PATZ1(-/-) mice were unfertile, suggesting a crucial role of this gene in spermatogenesis. Consistently, most of adult testes from these mice showed only few spermatocytes, associated with increased apoptosis, and complete absence of spermatids and spermatozoa, with the subsequent loss of tubular structure. The analysis of PATZ1 expression, by northern blot, western blot and immunohistochemistry, revealed its presence in Sertoli cells and, among the germ cells, exclusively in the spermatogonia. Since PATZ1 has been indicated as a potential tumour suppressor gene, we also looked at its expression in tumours deriving from testicular germ cells (TGCTs). Although expression of PATZ1 protein was increased in these tumours, it was delocalized in the cytoplasm, suggesting an impaired function. These results indicate that PATZ1 plays a crucial role in normal male gametogenesis and that its up-regulation and mis-localization could be associated to the development of TGCTs.

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