Identification of components of the host type IA phosphoinositide 3-kinase pathway that promote internalization of Listeria monocytogenes

The bacterial pathogen Listeria monocytogenes causes food-borne illnesses resulting in gastroenteritis, meningitis, or abortion. Listeria promotes its internalization into some human cells through binding of the bacterial surface protein InlB to the host receptor tyrosine kinase Met. The interaction of InlB with the Met receptor stimulates host signaling pathways that promote cell surface changes driving bacterial uptake. One human signaling protein that plays a critical role in Listeria entry is type IA phosphoinositide 3-kinase (PI 3-kinase). The molecular mechanism by which PI 3-kinase promotes bacterial internalization is not understood. Here we perform an RNA interference (RNAi)-based screen to identify components of the type IA PI 3-kinase pathway that control the entry of Listeria into the human cell line HeLa. The 64 genes targeted encode known upstream regulators or downstream effectors of type IA PI 3-kinase. The results of this screen indicate that at least 9 members of the PI 3-kinase pathway play important roles in Listeria uptake. These 9 human proteins include a Rab5 GTPase, several regulators of Arf or Rac1 GTPases, and the serine/threonine kinases phosphoinositide-dependent kinase 1 (PDK1), mammalian target of rapamycin (mTor), and protein kinase C-ζ. These findings represent a key first step toward understanding the mechanism by which type IA PI 3-kinase controls bacterial internalization.     

PI3KCA mutations and/or PTEN loss in Her2-positive breast carcinomas treated with trastuzumab are not related to resistance to anti-Her2 therapy

The purpose of this study is to evaluate whether activating mutations of the p110α catalytic subunit of class A phosphoinositide 3-kinases (PI3KCA) or complete loss of phosphatase and tensin homolog (PTEN) is associated with response to anti-human epidermal growth factor receptor 2 (Her2) treatment in breast cancer (BC). We analysed PI3KCA hot-spot mutations and PTEN immunohistochemical expression in 129 Her2-positive infiltrating BC treated with trastuzumab, including 26 cases treated with neoadjuvant therapy, 48 metastatic infiltrating breast cancer (IBC; MBC) and 55 early-stage IBC, with complete clinical information (mean follow-up 37, 66 and 32?months, respectively). PI3KCA hot-spot mutations were observed in 25 cases (19?%): 12 (9?%) in exon 9 and 13 (10?%) in exon 20. No correlations were observed between mutations and pathological and biological parameters. In patients treated with neoadjuvant therapy and in MBC, we did not observe any relationship with response to trastuzumab-based therapy. PTEN loss was observed in 24 out of 86 informative cases (28?%), 3 (13?%) of which were also mutated for PI3KCA. PI3K pathway activation, defined as PI3KCA mutation and/or PTEN loss, was not associated with response to treatment or clinical outcome in MBC. PI3KCA mutation and/or PTEN loss should not exclude patients from potentially beneficial anti-Her2 therapy.     

Evaluation of the new test VERSANT CT/GC DNA 1.0 assay for the detection of Chlamydia trachomatis and Neisseria gonorrhoeae in urine specimens

Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (GC) are the two most common sexually transmitted bacterial infections in developed countries. The purpose of the present study was evaluating a new system for CT/GC detection in urine specimens. A total of 700 urine specimens were obtained from patients attending the STD Outpatients Clinic of St. Orsola University Hospital, Bologna, Italy. Samples were tested by VERSANT? CT/GC DNA 1.0 Assay (Siemens Healthcare Diagnostics Inc., Tarrytown, NY), a multiplex Real-Time PCR assay, for simultaneous CT/GC detection. Results obtained by VERSANT assay were compared with those obtained by culturing genital secretions of the same patients. Moreover, urine specimens testing positive in VERSANT assay were retested by in-house PCR assays, used as confirmatory tests. VERSANT? CT/GC DNA 1.0 Assay performed with 99.4% and 99.2% of specificity for GC and CT detection, respectively, whereas sensitivity was 100% both for CT and GC. Culture methods were 100% specific, but far less sensitive than VERSANT assay. VERSANT? CT/GC DNA 1.0 Assay demonstrated to be a highly sensitive and specific technique for CT/GC detection.     

Multiple cycles of repeated treatments with a Phaseolus vulgaris dry extract reduce food intake and body weight in obese rats

Previous lines of experimental evidence have suggested that Phaseolus vulgaris extracts reduce food intake, body weight, lipid accumulation, hedonic properties of food, carbohydrate absorption and metabolism, and glycaemia in rats. The present study was designed to assess the effect of multiple cycles of repeated treatments with a standardised P. vulgaris dry extract on daily food intake and body weight in genetically obese Zucker fa/fa rats (Expt 1). Additionally, the study tested the effect of acute treatment with P. vulgaris dry extract on postprandial glycaemia in Zucker fa/fa rats (Expt 2). In Expt 1, P. vulgaris dry extract was administered daily, at doses of 50 and 500 mg/kg, in three 5 d treatment periods followed by three 20 d off-treatment periods. Administration of P. vulgaris dry extract resulted in dose-dependent decreases in daily food intake and body weight in each treatment phase. Reductions in food intake were of comparable magnitude in each treatment phase. In Expt 2, food-deprived rats were acutely treated with 50 and 500 mg P. vulgaris dry extract per kg immediately before access to a fixed amount of a starch-enriched chow. Treatment with P. vulgaris dry extract resulted in a dose-dependent suppression of glycaemia. These results extend previous data on the anorectic and hypoglycaemic effects of the P. vulgaris dry extract to a validated animal model of obesity. Together with data published previously in the literature, these results strengthen the hypothesis that potentially effective, novel pharmacotherapies for obesity and related disorders may originate from extracts and derivatives of P. vulgaris.     

Synthesis of 1-naphtylpiperazine derivatives as serotoninergic ligands and their evaluation as antiproliferative agents

Serotonin (5-hydroxytryptamine, 5-HT) is one of the most important neuromediator involved in numerous physiological and pathophysiological processes. In addition it is well established that 5-HT acts as a growth factor on several types of non-tumoral and tumoral cells, and recently it was also related to oncogenes. 5-HT1A receptor expression was identified in prostatic tumor cell lines (PC3 cells) and in human hormone refractory prostate cancer tissue. Based on these observations, development of 5-HT1A antagonists could be useful in inhibiting the growth of cancer cells. In order to investigate on potential use of 5-HT1A ligands as antiproliferative agents, we have analyzed a new set of 1-naphtylpiperazine derivatives. In binding studies, several molecules showed affinity in nanomolar and subnanomolar range at 5-HT1A and moderate to no affinity for other relevant receptors (5-HT2A, 5-HT2C, D1, D2, α1 and α2). All compounds were then evaluated in order to assess their antiproliferative activity using PC3 cells and the most active compounds (1 and 2) were fully characterized to define the mechanism responsible for the observed antiproliferative effect.     

Identification of 5-arylidene-4-thiazolidinone derivatives endowed with dual activity as aldose reductase inhibitors and antioxidant agents for the treatment of diabetic complications

In continuing the search for more effective 5-arylidene-4-thiazolidinones as aldose reductase inhibitors, a new set of suitably substituted compounds (4, 5 and 8) was explored. Acetic acids 5, particularly 5a and 5h, proved to be interesting inhibitors of the enzyme as well as excellent antioxidant agents that are potentially able to counteract the oxidative stress associated with both diabetic complications as well as other pathologies. Molecular docking experiments supported SAR studies.     

Neural language networks at birth

The ability to learn language is a human trait. In adults and children, brain imaging studies have shown that auditory language activates a bilateral frontotemporal network with a left hemispheric dominance. It is an open question whether these activations represent the complete neural basis for language present at birth. Here we demonstrate that in 2-d-old infants, the language-related neural substrate is fully active in both hemispheres with a preponderance in the right auditory cortex. Functional and structural connectivities within this neural network, however, are immature, with strong connectivities only between the two hemispheres, contrasting with the adult pattern of prevalent intrahemispheric connectivities. Thus, although the brain responds to spoken language already at birth, thereby providing a strong biological basis to acquire language, progressive maturation of intrahemispheric functional connectivity is yet to be established with language exposure as the brain develops.