Association between SNAP-25 gene polymorphisms and cognition in autism: functional consequences and potential therapeutic strategies

Synaptosomal-associated protein of 25 kDa (SNAP-25) is involved in different neuropsychiatric disorders, including schizophrenia and attention-deficit/hyperactivity disorder. Consistently, SNAP-25 polymorphisms in humans are associated with hyperactivity and/or with low cognitive scores. We analysed five SNAP-25 gene polymorphisms (rs363050, rs363039, rs363043, rs3746544 and rs1051312) in 46 autistic children trying to correlate them with Childhood Autism Rating Scale and electroencephalogram (EEG) abnormalities. The functional effects of rs363050 single-nucleotide polymorphism (SNP) on the gene transcriptional activity, by means of the luciferase reporter gene, were evaluated. To investigate the functional consequences that SNAP-25 reduction may have in children, the behaviour and EEG of SNAP-25(+/-) adolescent mice (SNAP-25(+/+)) were studied. Significant association of SNAP-25 polymorphism with decreasing cognitive scores was observed. Analysis of transcriptional activity revealed that SNP rs363050 encompasses a regulatory element, leading to protein expression decrease. Reduction of SNAP-25 levels in adolescent mice was associated with hyperactivity, cognitive and social impairment and an abnormal EEG, characterized by the occurrence of frequent spikes. Both EEG abnormalities and behavioural deficits were rescued by repeated exposure for 21 days to sodium salt valproate (VLP). A partial recovery of SNAP-25 expression content in SNAP-25(+/-) hippocampi was also observed by means of western blotting. A reduced expression of SNAP-25 is responsible for the cognitive deficits in children affected by autism spectrum disorders, as presumably occurring in the presence of rs363050(G) allele, and for behavioural and EEG alterations in adolescent mice. VLP treatment could result in novel therapeutic strategies.

A survey on feasibility of ICF-CY use to describe persisting difficulties in executing tasks and activities of children and adolescent with disability in Italy

BACKGROUND

The criterion for the provision of disability benefits to people under 18 in Italy is the presence of persistent difficulties in carrying out the duties and functions of their own age; however, no national guidelines are available to support the Disability Commissions in assessing such difficulties.

OBJECTIVE

This study identified the different kinds of persisting difficulties in performing tasks and activities of children and adolescents with disability in Italy.

METHODS

We used a protocol based on a selection of 55 categories taken from the Activity and Participation components of the International Classification of Functioning, Disability and Health - Children and Youth version. Problems were represented dividing children by age groups, and categories were selected as relevant if reported by 20% of the cases as very severe/complete problems. A count-based methodology was chosen and categories were counted at the level of domain, showing differences related to age groups. Count-based complexity and severity indexes were calculated, reflecting the global amount of problems and the portion of very severe/complete ones.

RESULTS

Out of 415 children with disability enrolled in the study, 290 had persisting difficulties, with those referring to domestic life, major life areas and learning being the most common, and with specific age-related trends. The highest number of problems was reported for children in the 4-6 year age group.

CONCLUSIONS

Our approach is meant to foster a way toward understanding disability and functioning as a continuum, based on the amount and severity of difficulties that children may have, as opposed to a categorical, diagnosis-based approach.

Design, synthesis and efficacy of novel G protein-coupled receptor kinase 2 inhibitors

G protein-coupled receptor kinase 2 (GRK2) is a relevant signaling node of the cellular transduction network, playing major roles in the physiology of various organs/tissues including the heart and blood vessels. Emerging evidence suggests that GRK2 is up regulated in pathological situations such as heart failure, hypertrophy and hypertension, and its inhibition offers a potential therapeutic solution to these diseases. We explored the GRK2 inhibitory activity of a library of cyclic peptides derived from the HJ loop of G protein-coupled receptor kinases 2 (GRK2). The design of these cyclic compounds was based on the conformation of the HJ loop within the X-ray structure of GRK2. One of these compounds, the cyclic peptide 7, inhibited potently and selectively the GRK2 activity, being more active than its linear precursor. In a cellular system, this peptide confirms the beneficial signaling properties of a potent GRK2 inhibitor. Preferred conformations of the most potent analog were investigated by NMR spectroscopy.

Discovery of PTPRJ agonist peptides that effectively inhibit in vitro cancer cell proliferation and tube formation

PTPRJ is a receptor protein tyrosine phosphatase involved in both physiological and oncogenic pathways. We previously reported that its expression is strongly reduced in the majority of explored cancer cell lines and tumor samples; moreover, its restoration blocks in vitro cancer cell proliferation and in vivo tumor formation. By means of a phage display library screening, we recently identified two peptides able to bind and activate PTPRJ, resulting in cell growth inhibition and apoptosis of both cancer and endothelial cells. Here, on a previously discovered PTPRJ agonist peptide, PTPRJ-pep19, we synthesized and assayed a panel of nonapeptide analogues with the aim to identify specific amino acid residues responsible for peptide activity. These second-generation nonapeptides were tested on both cancer and primary endothelial cells (HeLa and HUVEC, respectively); interestingly, one of them (PTPRJ-19.4) was able to both dramatically reduce cell proliferation and effectively trigger apoptosis of both HeLa and HUVECs compared to its first-generation counterpart. Moreover, PTPRJ-pep19.4 significantly inhibited in vitro tube formation on Matrigel. Intriguingly, while ERK1/2 phosphorylation and cell proliferation were both inhibited by PTPRJ-pep19.4 in breast cancer cells (MCF-7 and SKBr3), no effects were observed on primary normal human mammary endothelial cells (HMEC). We further characterized these peptides by molecular modeling and NMR experiments reporting, for the most active peptide, the possibility of self-aggregation states and highlighting new hints of structure-activity relationship. Thus, our results indicate that this nonapeptide might represent a great potential lead for the development of novel targeted anticancer drugs.

Synthesis and cytotoxic activity evaluation of 2,3-thiazolidin-4-one derivatives on human breast cancer cell lines

It is well known that resveratrol (RSV) displayed cancer-preventing and anticancer properties but its clinical application is limited because of a low bioavailability and a rapid clearance from the circulation. Aim of this work was to synthesize pharmacologically active resveratrol analogs with an enhanced structural rigidity and bioavailability. In particular, we have synthesized a library of 2,3-thiazolidin-4-one derivatives in which a thiazolidinone nucleus connects two aromatic rings. Some of these compounds showed strong inhibitory effects on breast cancer cell growth. Our results indicate that some of thiazolidin-based resveratrol derivatives may become a new potent alternative tool for the treatment of human breast cancer.

Synthesis, in vitro, and in cell studies of a new series of [indoline-3,2'-thiazolidine]-based p53 modulators

Analogues of the previously described spiro[imidazo[1,5-c]thiazole-3,3'-indoline]-2',5,7(6H,7aH)-trione p53 modulators were prepared to explore new structural requirements at the thiazolidine domain for the antiproliferative activity and p53 modulation. In cell, antiproliferative activity was evaluated against two human tumor cell lines. Derivative 5-bromo-3'-(cyclohexane carbonyl)-1-methyl-2-oxospiro[indoline-3,2'-thiazolidine] (4n) emerged as the most potent compound of this series, inhibiting in vitro 30% of p53-MDM2 interaction at 5 μM and the cell growth of different human tumor cells at nanomolar concentrations. Docking studies confirmed the interactions of 4n with the well-known Trp23 and Phe19 clefts, explaining the reasons for its binding affinity for MDM2. 4n at 50 nM is capable of inducing the accumulation of p53 protein, inducing significant apoptotic cell death without affecting the cell cycle progression. Comparative studies using nutlin in the same cellular system confirm the potential of 4n as a tool for increasing understanding of the process involved in the nontranscriptional proapoptotic activities of p53.

Cumulative risk of cancer detection in breast cancer screening by protocol strategy

BACKGROUND

There is little information on the individual risk of screen-detected cancer in women over successive participations. This study aimed to estimate the 10-year cumulative breast cancer detection risk (ductal carcinoma in situ and invasive carcinoma) in a population-based breast cancer screening program according to distinct protocol strategies. A further aim was to determine which strategies maximized the cancer detection risk and how this risk was affected by the radiologic protocol variables.

METHODS

Data were drawn from a retrospective cohort of women from nine population-based screening programs in Spain from 1990 to 2006. We used logistic regression with discrete intervals to estimate the cumulative detection risk at 10 years of follow-up according to radiologic variables and protocol strategies.

RESULTS

In women starting screening at the age of 45-59 years, the cumulative risk of screen-detected cancer at 10 years ranged from 11.11 to 16.71 per 1,000 participants according to the protocol strategy. The cumulative detection risk for overall cancer and invasive cancer was the highest with strategies using digital mammography, double reading, and two projections (16.71 and 12.07 ‰, respectively). For ductal carcinoma in situ, cumulative detection risk was the highest with strategies using screen-film, double reading, and two projections (2.32 ‰). The risk was the lowest with strategies using screen-film mammography, single reading, and two projections.

CONCLUSIONS

This study found that at least eleven cancers are detected per 1,000 women screened in the first 10 years of follow-up. Enhanced knowledge of the variability in cumulative risk of screen-detected cancer could improve protocol strategies.

Design, Synthesis, and Evaluation of New Tripeptides as COX-2 Inhibitors

Cyclooxygenase (COX) is a key enzyme in the biosynthetic pathway leading to the formation of prostaglandins, which are mediators of inflammation. It exists mainly in two isoforms COX-1 and COX-2. The conventional nonsteroidal anti-inflammatory drugs (NSAIDs) have gastrointestinal side effects because they inhibit both isoforms. Recent data demonstrate that the overexpression of these enzymes, and in particular of cyclooxygenases-2, promotes multiple events involved in tumorigenesis; in addition, numerous studies show that the inhibition of cyclooxygenases-2 can delay or prevent certain forms of cancer. Agents that inhibit COX-2 while sparing COX-1 represent a new attractive therapeutic development and offer a new perspective for a further use of COX-2 inhibitors. The present study extends the evaluation of the COX activity to all 20(3) possible natural tripeptide sequences following a rational approach consisting in molecular modeling, synthesis, and biological tests. Based on data obtained from virtual screening, only those peptides with better profile of affinity have been selected and classified into two groups called S and E. Our results suggest that these novel compounds may have potential as structural templates for the design and subsequent development of the new selective COX-2 inhibitors drugs.

Mice heterozygous for the oxytocin receptor gene (Oxtr(+/-)) show impaired social behaviour but not increased aggression or cognitive inflexibility: evidence of a selective haploinsufficiency gene effect

We characterised the behavioural phenotype of mice heterozygous (Oxtr(+/-)) for the oxytocin receptor gene (Oxtr) and compared it with that of Oxtr null mice (Oxtr(-/-)), which display autistic-like behaviours, including impaired sociability and preference for social novelty, impaired cognitive flexibility, and increased aggression. Similar to Oxtr(-/-) mice, the Oxtr(+/-) showed impaired sociability and preference for social novelty but, unlike the null genotype, their cognitive flexibility and aggression were normal. By autoradiography, Oxtr(+/-) mice were found to have approximately 50% fewer oxytocin receptors (OXTRs) in all of the examined brain regions. Thus, because a partial reduction in Oxtr gene expression is sufficient to compromise social behaviour, the Oxtr acts as a haploinsufficient gene. Furthermore, the inactivation of the Oxtr gene affects specific behaviours in a dose-dependent manner: social behaviour is sensitive to even a partial reduction in Oxtr gene expression, whereas defects in aggression and cognitive flexibility require the complete inactivation of the Oxtr gene to emerge. We then investigated the rescue of the Oxtr(+/-) social deficits by oxytocin (OT) and Thr(4)Gly(7)OT (TGOT) administered i.c.v. at different doses. TGOT was more potent than OT in rescuing sociability and social novelty in both genotypes. Furthermore, the TGOT doses that reverted impaired sociability and preference for social novelty in Oxtr(+/-) were lower than those required in Oxtr(-/-), thus suggesting that the rescue effect is mediated by OXTR in Oxtr(+/-) and by other receptors (presumably vasopressin V1a receptors) in Oxtr(-/-). In line with this, a low dose of the selective oxytocin antagonist desGlyDTyrOVT blocks the rescue effect of TGOT only in the Oxtr(+/-) genotype, whereas the less selective antagonist SR49059 blocks rescue in both genotypes. In conclusion, the Oxtr(+/-) mouse is a unique animal model for investigating how partial loss of the Oxtr gene impair social interactions, and for designing pharmacological rescue strategies.

Characterization of a selective CaMKII peptide inhibitor

Analogs of potent CaMKinase II inhibitor, CaM-KNtide, were prepared to explore new structural requirements for the inhibitory activity. The full potency of CaMKII inhibition by CaM-KIINα is contained within a minimal region of 19 amino acids. Here, analysis of the homologous CaM-KIINβ showed that a 17 mer peptide (CN17β) was the shortest sequence that still retained useful inhibitory potency. Ala substitution of almost any residue of CN17β dramatically reduced potency, except for substitution of P3, R14, and V16. Fusion with the tat sequence generated the cell-penetrating inhibitor version tat-5. This tat-5 fusion peptide maintained selectivity for CaMKII over CaMKI and CaMKIV, and appeared to slightly further enhance potency (IC50 ∼30 nM). Within a breast cancer cell line and in primary human fibroblasts, tat-5 inhibited the Erk signaling pathway and proliferation without any measurable cytotoxicity. Structural analysis of CN17β by CD and NMR indicated an α-helix conformation in the Leu6-Arg11 segment well overlapping with the crystal structure of 21-residue segment of CaM-KNtide bound to the kinase domain of CaMKII.

Heat shock protein 90 inhibitors as therapeutic agents

The molecular chaperone heat shock protein 90 (HSP90) is essential for the folding stability, intracellular disposition and proteolytic turnover of many of the key regulators of cell growth, differentiation and survival. These essential functions are used by the cells during the oncogenesis process to allow the tumor transformation and facilitate the rapid somatic evolution. Inhibition of HSP90 would provide combinatorial blockade of a range of oncogenic pathways, antagonizing many of the hallmark traits of cancer. Several HSP90 inhibitors are currently under clinical trial investigation for the treatment of cancer. This review summarizes the current state and progress achieved in the development of HSP90 inhibitors targeting the N-terminal ATP pocket, C-terminal domain, different compartmentalized isoforms, and protein (cochaperones and/or client proteins)/HSP90 interactions. In the context of drug discovery, the most relevant patents which appeared recently in the literature are discussed as well.

Synthesis and biological evaluation of new N-alkylcarbazole derivatives as STAT3 inhibitors: preliminary study

The signalling pathway of Janus tyrosine Kinases-Signal Transducers and Activators of Transcription (JAK-STAT) is activated by a number of cytokines, hormones (GH, erythropoietin and prolactin), and growth factors. JAK-STAT signalling is involved in regulation of cell proliferation, differentiation and apoptosis. These activities are due to different members of JAK-STAT family consisting of: JAK1, JAK2, JAK3, Tyk2 and STAT1, STAT2, STAT3, STAT4, STAT5a, STAT5b, STAT6. Recent studies suggest a key role for STAT family proteins, in particular for STAT3, in selectively inducing and maintaining a pro-carcinogenic inflammatory microenvironment, that promote tumour cells transformation. Moreover, a striking correlation between cancer development/progression and STAT3 persistent activation exists, probably due to STAT3 promoting of the pro-oncogenic inflammatory pathways, like NF-kB, IL-6 and JAK family kinases. Recent study demonstrated that carbazoles can inhibit STAT3 mediated transcription. From these evidences, STAT3 represents a therapeutic target, so we have synthesized a new set of N-alkylcarbazole derivatives substituted in positions 2, 4 and 6, to evaluate their activity on STAT3. Some of these compounds showed an interesting activity as STAT3 selective inhibitors; in particular, compounds 9a 9b and 9c revealed to inhibit the STAT3 activation for the 50%, 90% and 95%, respectively.

Identification of small-molecule enhancers of arginine methylation catalyzed by coactivator-associated arginine methyltransferase 1

Arginine methylation is a common post-translational modification that is crucial in modulating gene expression at multiple critical levels. The arginine methyltransferases (PRMTs) are envisaged as promising druggable targets, but their role in physiological and pathological pathways is far from being clear due to the limited number of modulators reported to date. In this effort, enzyme activators can be invaluable tools useful as gain-of-function reagents to interrogate the biological roles in cells and in vivo of PRMTs. Yet the identification of such molecules is rarely pursued. Herein we describe a series of aryl ureido acetamido indole carboxylates (dubbed "uracandolates"), able to increase the methylation of histone (H3) or nonhistone (polyadenylate-binding protein 1, PABP1) substrates induced by coactivator-associated arginine methyltransferase 1 (CARM1), both in in vitro and cellular settings. To the best of our knowledge, this is the first report of compounds acting as CARM1 activators.

Breast cancer detection risk in screening mammography after a false-positive result

BACKGROUND

False-positives are a major concern in breast cancer screening. However, false-positives have been little evaluated as a prognostic factor for cancer detection. Our aim was to evaluate the association of false-positive results with the cancer detection risk in subsequent screening participations over a 17-year period.

METHODS

This is a retrospective cohort study of 762,506 women aged 45-69 years, with at least two screening participations, who underwent 2,594,146 screening mammograms from 1990 to 2006. Multilevel discrete-time hazard models were used to estimate the adjusted odds ratios (OR) of breast cancer detection in subsequent screening participations in women with false-positive results.

RESULTS

False-positives involving a fine-needle aspiration cytology or a biopsy had a higher cancer detection risk than those involving additional imaging procedures alone (OR = 2.69; 95%CI: 2.28-3.16 and OR = 1.81; 95%CI: 1.70-1.94, respectively). The risk of cancer detection increased substantially if women with cytology or biopsy had a familial history of breast cancer (OR = 4.64; 95%CI: 3.23-6.66). Other factors associated with an increased cancer detection risk were age 65-69 years (OR = 1.84; 95%CI: 1.67-2.03), non-attendance at the previous screening invitation (OR = 1.26; 95%CI: 1.11-1.43), and having undergone a previous benign biopsy outside the screening program (OR = 1.24; 95%CI: 1.13-1.35).

CONCLUSION

Women with a false-positive test have an increased risk of cancer detection in subsequent screening participations, especially those with a false-positive result involving cytology or biopsy. Understanding the factors behind this association could provide valuable information to increase the effectiveness of breast cancer screening.

Isolation and functional characterization of peptide agonists of PTPRJ, a tyrosine phosphatase receptor endowed with tumor suppressor activity

PTPRJ is a receptor-type protein tyrosine phosphatase whose expression is strongly reduced in the majority of investigated cancer cell lines and tumor specimens. PTPRJ negatively interferes with mitogenic signals originating from several oncogenic receptor tyrosine kinases, including HGFR, PDGFR, RET, and VEGFR-2. Here we report the isolation and characterization of peptides from a random peptide phage display library that bind and activate PTPRJ. These agonist peptides, which are able to both circularize and form dimers in acqueous solution, were assayed for their biochemical and biological activity on both human cancer cells and primary endothelial cells (HeLa and HUVEC, respectively). Our results demonstrate that binding of PTPRJ-interacting peptides to cell cultures dramatically reduces the extent of both MAPK phosphorylation and total phosphotyrosine levels; conversely, they induce a significant increase of the cell cycle inhibitor p27(Kip1). Moreover, PTPRJ agonist peptides both reduce proliferation and trigger apoptosis of treated cells. Our data indicate that peptide agonists of PTPRJ positively modulate the PTPRJ activity and may lead to novel targeted anticancer therapies.

Evaluation of the soluble fragments of cytokeratin 19 (CK19) in non-small cell lung cancer (NSCLC)

This study compared the diagnostic efficacy of serum CK19 determination (Cyfra 21-1) with other tumour markers, such as CEA, SCC, NSE, TPA, in patients with resected non-small lung cancer. Tumour marker levels were tested in 90 patients with benign lung disease and at diagnosis in 72 patients with proven NSCLC, 39 squamous cell carcinoma and 33 adenocarcinoma. At presentation baseline levels of all tumor markers were significantly higher (p<0.05) in lung cancer patients than in control subjects, except for NSE. A significant increase (p<0.05) in serum concentrations was observed from stage I to stage IIIb only for Cyfra 21-1 (stage I/II, median=2.7 ng/ml; stage IIIb, median=6.3 ng/ml) and TPA (stage I/II, median=89.8 IU/ml; stage IIIb, median=170.7 IU/ml). Receiver operating characteristic (ROC) analysis was performed to evaluate the best threshold values and the global accuracy of each marker. The highest global sensitivity for NSCLC was reached by TPA (70.8%), whereas that of Cyfra 21-1 was 50%. According to tumour histology, significant difference (p<0.05) in serum levels were found only for CEA (adenocarcinomas, median=5.6 ng/ml; squamous cell carcinoma, median=3.2 ng/ml) and SCC (adenocarcinomas, median=1.0 ng/ml; squamous cell carcinoma, median=1.5 ng/ml). As regards squamous cell carcinoma histotype, the highest sensitivity was obtained by TPA (74.4% at a specificity of 62.2%) and for adenocarcinomas by CEA (78.8% at a specificity of 85.6%). Tumour marker levels were also determined during the follow-up of 10 patients. The best sensitivity in detecting relapses was shown by CEA (90%), followed by TPA (70%), SCC (50%), Cyfra 21-1 (40%) and NSE (10%), even though the CEA test displayed a high percentage of false positive results (98.1%) in patients with no evidence of disease (NED).

Inter- and intraradiologist variability in the BI-RADS assessment and breast density categories for screening mammograms

OBJECTIVE

The aim of this study was to evaluate reader variability in screening mammograms according to the American College of Radiology Breast Imaging Reporting and Data System (BI-RADS) assessment and breast density categories.

METHODS

A stratified random sample of 100 mammograms was selected from a population-based breast cancer screening programme in Barcelona, Spain: 13 histopathologically confirmed breast cancers and 51 with true-negative and 36 with false-positive results. 21 expert radiologists from radiological units of breast cancer screening programmes in Catalonia, Spain, reviewed the mammography images twice within a 6-month interval. The readers described each mammography using BI-RADS assessment and breast density categories. Inter- and intraradiologist agreement was assessed using percentage of concordance and the kappa (κ) statistic.

RESULTS

Fair interobserver agreement was observed for the BI-RADS assessment [κ=0.37, 95% confidence interval (CI) 0.36-0.38]. When the categories were collapsed in terms of whether additional evaluation was required (Categories III, 0, IV, V) or not (I and II), moderate agreement was found (κ=0.53, 95% CI 0.52-0.54). Intra-observer agreement for BI-RADS assessment was moderate using all categories (κ=0.53, 95% CI 0.50-0.55) and substantial on recall (κ=0.66, 95% CI 0.63-0.70). Regarding breast density, inter- and intraradiologist agreement was substantial (κ=0.73, 95% CI 0.72-0.74 and κ=0.69, 95% CI 0.68-0.70, respectively).

CONCLUSION

We observed a substantial intra-observer agreement in the BI-RADS assessment but only moderate interobserver agreement. Both inter- and intra-observer agreement in mammographic interpretation of breast density was substantial. Advances in knowledge Educational efforts should be made to decrease radiologists' variability in BI-RADS assessment interpretation in population-based breast screening programmes.

A population survey in Italy based on the ICF classification: recognizing persons with severe disability

Aim of this paper is to describe functioning of subjects with "severe disability" collected with a protocol based on the International Classification of Functioning, Disability, and Health. It included sections on body functions and structures (BF and BS), activities and participation (A&P), and environmental factors (EF). In A&P, performance without personal support (WPS) was added to standard capacity and performance. Persons with severe disability were those reporting a number of very severe/complete problems in BF or in A&P-capacity superior to mean + 1SD. Correlations between BF and A&P and differences between capacity, performance-WPS, and performance were assessed with Spearman's coefficient. Out of 1051, 200 subjects were considered as severely disabled. Mild to moderate correlations between BF and A&P were reported (between 0.148 and 0.394 when the full range of impairments/limitations was taken into account; between 0.198 and 0.285 when only the severe impairments/limitations were taken into account); performance-WPS was less similar to performance than to capacity. Our approach enabled identifying subjects with "severe disability" and separating the effect of personal support from that of devices, policies, and service provision.