Use of QSAR Global Models and Molecular Docking for Developing New Inhibitors of c-src Tyrosine Kinase.

A prototype of a family of at least nine members, cellular Src tyrosine kinase is a therapeutically interesting target because its inhibition might be of interest not only in a number of malignancies, but also in a diverse array of conditions, from neurodegenerative pathologies to certain viral infections. Computational methods in drug discovery are considerably cheaper than conventional methods and offer opportunities of screening very large numbers of compounds in conditions that would be simply impossible within the wet lab experimental settings. We explored the use of global quantitative structure-activity relationship (QSAR) models and molecular ligand docking in the discovery of new c-src tyrosine kinase inhibitors. Using a dataset of 1038 compounds from ChEMBL database, we developed over 350 QSAR classification models. A total of 49 models with reasonably good performance were selected and the models were assembled by stacking with a simple majority vote and used for the virtual screening of over 100,000 compounds. A total of 744 compounds were predicted by at least 50% of the QSAR models as active, 147 compounds were within the applicability domain and predicted by at least 75% of the models to be active. The latter 147 compounds were submitted to molecular ligand docking using AutoDock Vina and LeDock, and 89 were predicted to be active based on the energy of binding.

Tests in mice of a dengue vaccine candidate made of chimeric Junin virus-like particles and conserved dengue virus envelope sequences.

Two new vaccine candidates against dengue virus (DENV) infection were generated by fusing the coding sequences of the self-budding Z protein from Junin virus (Z-JUNV) to those of two cryptic peptides (Z/DENV-P1 and Z/DENV-P2) conserved on the envelope protein of all serotypes of DENV. The capacity of these chimeras to generate virus-like particles (VLPs) and to induce virus-neutralizing antibodies in mice was determined. First, recombinant proteins that displayed reactivity with a Z-JUNV-specific serum by immunofluorescence were detected in HEK-293 cells transfected with each of the two plasmids and VLP formation was also observed by transmission electron microscopy. Next, we determined the presence of antibodies against the envelope peptides of DENV in the sera of immunized C57BL/6 mice. Results showed that those animals that received Z/DENV-P2 DNA coding sequences followed by a boost with DENV-P2 synthetic peptides elicited significant specific antibody titers (≥6.400). Finally, DENV plaque-reduction neutralization tests (PRNT) were performed. Although no significant protective effect was observed when using sera of Z/DENV-P1-immunized animals, antibodies raised against vaccine candidate Z/DENV-P2 (diluted 1:320) were able to reduce in over 50 % the number of viral plaques generated by infectious DENV particles. This reduction was comparable to that of the 4G2 DENV-specific monoclonal cross-reactive (all serotypes) neutralizing antibody. We conclude that Z-JUNV-VLP is a valid carrier to induce antibody-mediated immune responses in mice and that Z/DENV-P2 is not only immunogenic but also protective in vitro against infection of cells with DENV, deserving further studies. On the other side, DENV's fusion peptide-derived chimera Z/DENV-P1 did not display similar protective properties.

Correlation between adenoma and serrated lesion detection rates in an unselected outpatient population.

BACKGROUND: Serrated lesions have been recently implicated in colorectal carcinogenesis. Adenoma detection rate has been related with the risk of interval cancer. The correlation between adenoma detection rate and the serrated lesion detection rate is unclear. AIM: To assess the correlation between adenoma- and serrated lesion-detection rate in an unselected setting of outpatient colonoscopies. METHODS: Consecutive outpatients were retrospectively evaluated in one centre. Detection rates were expressed as number of patients with at least one serrated lesion or adenoma. For each endoscopist, correlation between adenoma detection rate and serrated lesions detection rate was calculated. RESULTS: Six endoscopists performed 2974 colonoscopies. 3240 lesions (59.5% adenomas, 37.8% serrated lesions, 0.5% cancer, and 2.3% other histology) were detected in 1228 procedures. Median adenoma detection rate and serrated lesions detection rate per endoscopist were 29.3% and 22.4%, respectively. A positive correlation between adenoma and serrated lesion detection rate (r(2)=0.78, p<0.001) was detected. CONCLUSIONS: Our study showed a statistically significant correlation between adenoma detection rate and serrated detection rate.

Pseudomembranous collagenous colitis with superimposed drug damage.

Pseudomembranous collagenous colitis is a rare pathological condition, not related to infectious agents, and characterized by thickening of the subepithelial collagen and formation of pseudomembranes. We report one such case, which responded to budesonide treatment after failures of previous approaches given, being unaware of the correct diagnosis.

Primary vulvar Ewing's sarcoma/primitive neuroectodermal tumor in a post-menopausal woman: a case report.

Ewing's sarcomas/peripheral primitive neuroectodermal tumors (ES/pPNETs) are high-grade malignant neoplasms rarely found outside the skeletal system. Only 12 cases of vulvar ES/pPNET have so far been reported, all involving children or women of child-bearing age. We describe the case of a 52-year-old woman who was admitted to our hospital for the local excision of a 4cm vulvar mass, originally thought to be a Bartholin's gland cyst. It was subsequently found to consist of small round cells positive for anti-CD99 antibody, thus suggesting a diagnosis of ES/pPNET. The demonstration of EWSR1 gene translocations by means of fluorescent in situ hybridization excluded small-cell carcinoma, squamous cell carcinoma of the small type, Merkel cell carcinoma, and lymphoblastic lymphoma. After surgery, the patient received six cycles of polychemotherapy and radiotherapy; she is still alive and well after 1 year of follow-up. Our findings underline the crucial role of molecular biology techniques in the differential diagnosis of small round cell tumors in these unusual locations.

Lymph node isolated tumor cells and micrometastases in pathological stage I non-small cell lung cancer: prognostic significance.

OBJECTIVE: To determine the prevalence and prognostic significance of lymph node micrometastases and isolated tumor cells (ITC) in patients submitted for radical resection for pathological stage I non-small cell lung cancer (NSCLC). METHODS: From January 1998 through December 2005, 87 consecutive pT1-2, pN0 NSCLC patients were enrolled. Surgical specimens were submitted to pathological routine examinations to define histotype, grade, stage, vascular invasion, necrosis and tumor proliferative index. A total of 694 regional lymph nodes were examined by means of serial sections stained with hematoxylin and eosin and labelled by immunohistochemistry (antibody AE1/AE3, DAKO). Relationships between these parameters and patients' prognosis were investigated. RESULTS: By histological examination, there were 36 squamous-cell carcinoma, 38 adenocarcinoma and 13 large-cell carcinoma. Micrometastases and ITC were detected in 19 lymph nodes (2.7%) of 14 patients (16%). Significant correlation was observed between micrometastases or ITC and adenocarcinoma (p=0.03) and the absence of necrosis (p=0.05). No relationship was demonstrated between micrometastases or ITC and T-status, vascular invasion or proliferative index (p>0.05). Median follow-up was 3.2 (range 0.25-8.6) years. Two- and 5-year disease-free survival was similar for patients with and without micrometastases or ITC (79% and 64% vs 81% and 64%, respectively). Recurrence occurred in three patients with (two local, 66%) and in 21 patients without micrometastases or ITC (three local, 14%) (p=0.186). By multivariate analysis only T-status was demonstrated to be a significant prognostic factor. DISCUSSION: Micrometastases or ITC to regional lymph nodes are demonstrated to be not a rare aspect of pathological stage I resected lung cancer. In our series, the presence of lymph nodes micrometastases does not affect long-term disease-free survival.