Genetic and environmental risk indicators in canine non-Hodgkin's lymphomas: breed associations and geographic distribution of 608 cases diagnosed throughout France over 1 year

BACKGROUND

The etiology of non-Hodgkin's lymphomas (NHL) is multifactorial. Environmental and genetic factors are frequently incriminated both in humans and dogs.

OBJECTIVES

Our purpose was to study the geographic distribution of canine NHL (CNHL) in France and to evaluate genetic and environmental influences.

ANIMALS

Six hundred and eight cases of CNHL, diagnosed throughout France over 1 year, were collected from 7 Veterinary Histopathologic Laboratories.

METHODS

Retrospective study. Breeds affected by lymphomas were compared with the national population and associations between breed and immunophenotype were studied. The distribution of CNHL and canine T-cell NHL per 100,000 dogs per department was compared with the distribution of waste incinerators, polluted sites, and radioactive waste.

RESULTS

The breeds significantly overrepresented among lymphoma cases were Boxer, Setter, and Cocker Spaniel (P < .001). There was a significant association between Boxer and T-cell NHL (P < .001), and between German Shepherd and Rottweiler and B-cell NHL (P < .01). The geographic distribution of CNHL and canine T-cell NHL indicated significant heterogeneity. Significant association between distributions of CNHL and waste incinerators (rho= 0.25, P < .05), polluted sites (rho= 0.36, P < .001), and radioactive waste (rho= 0.51, P < .001) was found.

CONCLUSIONS AND CLINICAL IMPORTANCE

Influence of genetics in the development of CNHL was supported by the existence of an association between breed and immunophenotype. Waste incinerators, polluted sites, and radioactive waste could just be considered as risk indicators of CNHL, but not as risk factors. Case-control studies around critical sites are necessary to confirm the implication of those environmental factors in the development of CNHL.

Synthesis, binding affinity and SAR of new benzolactam derivatives as dopamine D3 receptor ligands

A series of new benzolactam derivatives was synthesized and the derivatives were evaluated for their affinities at the dopamine D(1), D(2), and D(3) receptors. Some of these compounds showed high D(2) and/or D(3) affinity and selectivity over the D(1) receptor. The SAR study of these compounds revealed structural characteristics that decisively influenced their D(2) and D(3) affinities. Structural models of the complexes between some of the most representative compounds of this series and the D(2) and D(3) receptors were obtained with the aim of rationalizing the observed experimental results. Moreover, selected compounds showed moderate binding affinity on 5-HT(2A) which could contribute to reducing the occurrence of extrapyramidal side effects as potential antipsychotics.

Combination or sequential single agent for the treatment of metastatic breast cancer (MBC) patients (pts). Impact of further chemotherapy (CT) in overall survival (OS) in the Alamo registry

Abstract #2121

Introduction: Combinations can improve OS in MBC; however sequential single agent is sometimes preferred. In a recent report, pts receiving paclitaxel monotherapy in first line had a significantly worse OS if they were not receiving post study CT (PSC); no difference was seen in pts receiving paclitaxel+gemcitabine (Llombart, EBCC 2008). In this trial only 58% of pts received PSC.&#x2028; Purpose: To assess, outside the context of a clinical trial, the amount of MBC pts receiving CT beyond first line, as well as the impact of combination use and further CT lines in their OS.&#x2028; Methods: Alamo 1-2 is a breast cancer patient registry run by the GEICAM. 15482 pts diagnosed from 1990-1997 in 54 sites were included in the database. 4668 pts were stage IV; 778 (16.7%) metastatic at diagnosis and 3890 (83.3%) have had a recurrence.&#x2028; Results: 3045 (65%) pts received CT in first line, 83% were combinations (with anthracyclines 42%, CMF 16%, taxane+anthracyclines 9.4% or +other agents 8%) and 16% were monotherapy. Among other variables studied, only previous treatment (in early stage) was influencing the choice of a combination (pts without previous CT received more combinations than pts receiving CMF, than pts receiving anthracyclines). Median survival for pts receiving single agent was significantly shorter compared to pts receiving combination, 16.2 and 21.85 months (m) respectively, HR=1.37 (IC 95%: 1.21-1.55; p&lt;0.0001). Several covariates showed significant prognostic value in survival in the Cox multivariate model: monotherapy treatment in first line, anthracyclines pre-exposure, age &gt; 65, negative hormonal receptor status, hepatic disease, Grade 3 and ≥ 3 disease sites. Half of the pts never received further CT after first line treatment. Only age and number of disease sites were influencing this decision in the Cox multivariate model. Median survival was 24.9 m in pts receiving further CT and 14.5 m in the ones not receiving it. In pts not receiving further CT, median OS was significantly shorter if they were treated with single agent in first line in comparison to those receiving previous combination: HR= 1.59 (IC 95%: 1.33-1.89; p&lt; 0,00001). This difference was not significant in pts receiving further CT: HR= 1.15 (IC 95%: 0.97-1.37; p=0.101).&#x2028; Conclusion: Our data show that only half of the MBC pts receive further CT after first line; they have longer survival. We found significant evidence that further CT is impacting the OS in pts treated with single agent in first line, but not in those receiving previous combination. Those facts should be taken into consideration when selecting single agent or a combination in first line.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 2121.

Phase II study of combination cetuximab and weekly paclitaxel in patients with metastatic/recurrent squamous cell carcinoma of head and neck (SCCHN): Spanish Head and Neck Cancer Group (TTCC)

6012

Background: Cetuximab and paclitaxel have shown to be active in SCCHN pts and preclinical data has demonstrated a possible synergy for the combination. In a variety of tumor types, weekly paclitaxel has demonstrated an improved safety profile and activity as compared to every 3 weeks paclitaxel, providing the rationale to study the combination of cetuximab and weekly paclitaxel in metastatic/recurrent SCCHN. Methods: Pts were required to have a y performance status (KPS) = 70%, measurable disease using RECIST criteria, and may have received one regimen of induction and/or concomitant chemotherapy, but not within the recurrent/metastatic setting. Treatment included weekly paclitaxel 80 mg/m2 and cetuximab (initial dose of 400 mg/m2, followed by a weekly infusion of 250 mg/m2). Biopsies of tumors and samples of blood are being analyzed for correlative markers including EGFR gene copy number -FISH-, polymorphisms of intron 1 of the EGFR, and downstream EGFR pathway markers and mutations. Results: 46 planned pts were enrolled from Ap-2006 to Sep-2006. Median age is 60 years (range 42–78). Median KPS is 80% (range 70–100%). 35 pts are evaluable for response. Complete responses have been observed in 7 pts, partial responses in 18 pts, and stable disease in 6 pts for an overall response rate of 71% and disease control rate of 88%. 44 pts are evaluable for safety. Main grade 3/4 toxicities(NCI): 8 pts had acne- like rash; 7 neutropenia but only 1 febrile neutropenia; 6 asthenia; 3 mucositis; 2 infusion related reactions to paclitaxel and 1 to cetuximab; 2 peripheral neuropathies; 1 diarrhea; 1 vomiting; and 1 conjunctivitis. Conclusions: This trial shows that the combination of cetuximab and weekly paclitaxel is well tolerated and provides very encouraging activity in advanced/recurrent SCCHN. The full data, including biomarker results, will be presented at the annual meeting.

No significant financial relationships to disclose.

Multistructure 3D-QSAR studies on a series of conformationally constrained butyrophenones docked into a new homology model of the 5-HT2A receptor

The present study is part of a long-term research project aiming to gain insight into the mechanism of action of atypical antipsychotics. Here we describe a 3D-QSAR study carried out on a series of butyrophenones with affinity for the serotonin-2A receptor, aligned by docking into the binding site of a receptor model. The series studied has two peculiarities: (i) all the compounds have a chiral center and can be represented by two enantiomeric structures, and (ii) many of the structures can bind the receptor in two alternative orientations, posing the problem of how to select a single representative structure for every compound. We have used an original solution consisting of the simultaneous use of multiple structures, representing different configurations, binding conformations, and positions. The final model showed good statistical quality (n = 426, r2 = 0.84, q2LOO = 0.81) and its interpretation provided useful information, not obtainable from the simple inspection of the ligand-receptor complexes.

The «El Álamo» project (1990–1997): two consecutive hospital-based studies of breast cancer outcomes in Spain

BACKGROUND

The "Alamo" project is a retrospective analysis of 14,854 patients diagnosed of breast cancer between 1990 and 1997 in 50 Spanish hospitals.

METHODS

Alamo I (AI) consisted of 4,532 patients diagnosed with breast cancer between 1990 and 1993. Data were collected in 2000. Alamo II (AII) consisted of 10,322 patients diagnosed between 1994 and 1997. Data were collected in 2003.

RESULTS

At presentation, there were (AI vs. AII) 17.6% vs. 24.3% at stage I; 55.5% vs. 53.1% at stage II; 18.7% vs. 15% at stage III; 7.2% vs. 5.9 at stage IV. Median age was 57 (AI) vs. 58 years (AII) and 65.9% vs. 67.2% (AI vs. AII) were post-menopausal. Firstline treatment for disease stages I, II and III was surgery in 91% of patients in both studies. Breast conserving surgery rate increased from 20.2% (AI) to 32.7% (AII). Adjuvant systemic treatments were administered to 87.6% (AI) and 92.8% (AII) of patients. Recurrence rate diminished from 36.6% (AI) to 22.5% (AII) and the 9-year survival rate increased from 63.2% (95% CI: 61.5-64.9) to 70.1% (95% CI: 68.5-71.8).

CONCLUSION

Breast cancer outcomes in Spain have improved from 1990-1993 to 1994-1997, likely because of breast cancer screening program implementation and new therapies.

QF2004B, a potential antipsychotic butyrophenone derivative with similar pharmacological properties to clozapine

The aim of the present work was to characterize a lead compound displaying relevant multi-target interactions, and with an in vivo behavioral profile predictive of atypical antipsychotic activity. Synthesis, molecular modeling and in vitro and in vivo pharmacological studies were carried out for 2-[4-(6-fluorobenzisoxazol-3-yl)piperidinyl]methyl-1,2,3,4-tetrahydro-carbazol-4-one (QF2004B), a conformationally constrained butyrophenone analogue. This compound showed a multi-receptor profile with affinities similar to those of clozapine for serotonin (5-HT2A, 5-HT1A, and 5-HT2C), dopamine (D1, D2, D3 and D4), alpha-adrenergic (alpha1, alpha2), muscarinic (M1, M2) and histamine H1 receptors. In addition, QF2004B mirrored the antipsychotic activity and atypical profile of clozapine in a broad battery of in vivo tests including locomotor activity (ED50 = 1.19 mg/kg), apomorphine-induced stereotypies (ED50 = 0.75 mg/kg), catalepsy (ED50 = 2.13 mg/kg), apomorphine- and DOI (2,5-dimethoxy-4-iodoamphetamine)-induced prepulse inhibition (PPI) tests. These results point to QF2004B as a new lead compound with a relevant multi-receptor interaction profile for the discovery and development of new antipsychotics.

Anchor−GRIND: Filling the Gap between Standard 3D QSAR and the GRid-INdependent Descriptors

The aim of this work is to present the anchor-GRIND methodology. Anchor-GRIND efficiently combines a priori chemical and biological knowledge about the studied compounds with alignment-independent molecular descriptors derived from molecular interaction fields. Such descriptors are particularly useful for series of ligands sharing a common scaffold but with very diverse substituents. The method uses a specific position of the molecular structure (the "anchor point") to compare the spatial distribution of the molecular interaction fields of the substituents. The descriptors produced are more detailed and specific than the original GRIND while still avoiding the bias introduced by the alignment. Three data sets have been studied to demonstrate the usefulness of the anchor-GRIND methodology for 3D-QSAR modeling. The two first data sets respectively include congeneric series of the hepatitis C virus NS3 protease and of the acetylcholinesterase inhibitors. The third data set discriminates between factor Xa inhibitors of high and low affinity. In all the series presented, the models obtained with the anchor-GRIND are statistically sound and easy to interpret.

Comparative Analysis of Putative Agonist-Binding Modes in the Human A1 Adenosine Receptor

A recent study reported a model of the human A(1) adenosine receptor and its agonist binding site, proposing two putative binding modes in the same binding site for the natural agonist, adenosine. The present work investigates the flexibility of this binding site by exhaustive exploration with the natural agonist and with three other adenosine derivatives: N6-cyclopentyladenosine (CPA), 2-chloro-N6-cyclopentyladenosine (CCPA), and 5'-N-ethylcarboxamidoadenosine (NECA). Our aim was to find a common binding mode for agonists that would explain the role in the binding process of the different substitutions allowed at the 2, N6, and 5' positions of adenosine. This problem was addressed through docking simulations, molecular dynamics studies, and estimations of the ligand-binding free energy with both the AUTODOCK scoring function and the linear interaction energy (LIE) approach. The results point to a single receptor-binding position that explains the effects of the different chemical modifications on the adenosine derivatives considered here.

Incorporating Molecular Shape into the Alignment-free GRid-INdependent Descriptors

The recently introduced GRid-INdependent Descriptors (GRIND) were designed to provide a suitable description of a series of ligands for 3D-QSAR studies not requiring the spatial superimposition of their structures. Despite the proven usefulness of the method, it was recognized that the original GRIND failed to describe appropriately the shape of the ligand molecules, which in some cases plays a major role in ligand-receptor binding. For this reason, the original descriptors have been enhanced with the addition of a molecular shape description based on the local curvature of the molecular surface. The integration of this description into the GRIND allows the generation of 3D-QSAR models able to identify both favorable and unfavorable shape complementarity in a simple and alignment-independent way. The usefulness of the new GRIND-shape description in 3D-QSAR is illustrated using two structure-activity studies: one performed on a set of xanthine-like antagonists of the A(1) adenosine receptor; another performed on a series of Plasmodium falciparum plasmepsin II inhibitors.

Novel approaches for modeling of the A1adenosine receptor and its agonist binding site

The present work describes the building of a human A(1) adenosine receptor (hA(1)AR) model, based on the X-ray crystal structure of bovine rhodopsin, and its use as a basis for the investigation of some important structural characteristics of the receptor. One of the issues investigated was the protonation position of two histidine residues known to influence ligand binding, with protonation of His251 (6.52) in epsilon position and His278 (7.43) in delta position showing the best agreement with experimental evidence. The model was also used to study the position and structural role of water molecules present in the helical bundle. Finally, the binding site location and the ligand docking were investigated using an objective strategy. A suitable site for the binding of the ribose moiety of adenosine was first postulated and further confirmed by means of a novel chemometric strategy based on GRIND descriptors. Using this position as an anchor point, the binding of adenosine was studied by docking and molecular dynamics simulations obtaining two putative binding positions in good agreement with experimental data.

Conformationally constrained butyrophenones as new pharmacological tools to study 5-HT 2A and 5-HT 2C receptor behaviours

This study presents new pharmacological and molecular modelling studies on a recently described series of conformationally constrained butyrophenones. Alignment-free three-dimensional quantitative structure-activity relationship models developed on the basis of GRid Independent descriptors and partial least squares regression analysis, allow feasible predictions of activity of new compounds and reveal structural requirements for optimal affinity, particularly in the case of the 5-HT(2A) receptor. The requirements for the 5-HT(2A) affinity consist in a precise distance between hydrogen bond donor (protonated amino group) and hydrogen bond acceptor groups, as well as an optimal distance between the protonated amino group and the farthest extreme of the compounds. Another significant result has been the characterisation of two structurally similar compounds as interesting pharmacological tools (1-[(4-Oxo-4,5,6,7-tetrahydrobenzo[b]furan-5-yl)ethyl]-4-(6-fluorobenzisoxazol-3-yl)piperidine and 1-[(4-Oxo-4,5,6,7-tetrahydrobenzo[b]furan-6-yl)methyl]-4-(6-fluorobenzisoxazol-3-yl)piperidine). In spite of their structural similarity, the first compound shows clearly higher affinity for the 5-HT(2C) receptor (about 100 fold) and higher Meltzer ratio (1.17 vs. 0.99) than the second. Moreover, the first compound inhibits arachidonic acid release in a biphasic concentration-dependent way in functional experiments at the 5-HT(2A) receptor and it acts as inverse agonist at the 5-HT(2C) receptor, behaviours that are not shown by the second compound.

Surface descriptors for protein-ligand affinity prediction

Molecular descriptors calculated by the VolSurf program have been extensively used to model pharmacokinetic properties, e.g., passive permeability through the gastrointestinal tract or through the blood-brain barrier. These descriptors quantify steric, hydrophobic, and hydrogen bond interactions between model compounds and different environments. Since these interactions are the same as those involved in the ligand-receptor binding, VolSurf descriptors could potentially be relevant in modeling this process as well. We obtained a significant model (r(2) = 0.85, q(2) = 0.75) using VolSurf descriptors derived from the ligand, the protein, and the ligand-protein complex for a diverse set of 38 structures previously used in the VALIDATE (ref 23) training set. Furthermore, a statistically significant model (r(2) = 0.94, q(2) = 0.89) was obtained using the same type of descriptors for a homogeneous set of glycogen phosphorylase inhibitors (ref 25). Using the VolSurf computational framework, both ligand-receptor binding and the ligand's pharmacokinetic behavior can be modeled simultaneously during the preclinical aspects of drug discovery.