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Triple-negative breast cancers (TNBC) have an aggressive phenotype with a relatively high rate of recurrence and poor overall survival. To date, there is no approved targeted therapy for TNBCs. Aurora kinases act as regulators of mammalian cell division. They are important for cell-cycle progression and are frequently overexpressed or mutated in human tumors, including breast cancer. In this study, we investigated the therapeutic potential of targeting Aurora kinases in preclinical models of human breast cancers using a pan-inhibitor of Aurora kinases, AS703569. In vitro, AS703569 was tested in 15 human breast cancer cell lines. TNBC cell lines were more sensitive to AS703569 than were other types of breast cancer cells. Inhibition of proliferation was associated with cell-cycle arrest, aneuploidy, and apoptosis. In vivo, AS703569 administered alone significantly inhibited tumor growth in seven of 11 patient-derived breast cancer xenografts. Treatment with AS703569 was associated with a decrease of phospho-histone H3 expression. Finally, AS703569 combined to doxorubicin–cyclophosphamide significantly inhibited in vivo tumor recurrence, suggesting that Aurora kinase inhibitors could be used both in monotherapy and in combination settings. In conclusion, these data indicate that targeting Aurora kinases could represent a new effective approach for TNBC treatment. Mol Cancer Ther; 11(12); 2693–703. ©2012 AACR.

Purpose: Patients with luminal breast cancer (LBC) often become endocrine resistant over time. We investigated the molecular changes associated with acquired hormonoresistances in patient-derived xenografts of LBC.Experimental Design: Two LBC xenografts (HBCx22 and HBCx34) were treated with different endocrine treatments (ET) to obtain xenografts with acquired resistances to tamoxifen (TamR) and ovariectomy (OvaR). PI3K pathway activation was analyzed by Western blot analysis and IHC and responses to ET combined to everolimus were investigated in vivo. Gene expression analyses were performed by RT-PCR and Affymetrix arrays.Results: HBCx22 TamR xenograft was cross-resistant to several hormonotherapies, whereas HBCx22 OvaR and HBCx34 TamR exhibited a treatment-specific resistance profile. PI3K pathway was similarly activated in parental and resistant xenografts but the addition of everolimus did not restore the response to tamoxifen in TamR xenografts. In contrast, the combination of fulvestrant and everolimus induced tumor regression in vivo in HBCx34 TamR, where we found a cross-talk between the estrogen receptor (ER) and PI3K pathways. Expression of several ER-controlled genes and ER coregulators was significantly changed in both TamR and OvaR tumors, indicating impaired ER transcriptional activity. Expression changes associated with hormonoresistance were both tumor and treatment specific and were enriched for genes involved in cell growth, cell death, and cell survival.Conclusions: PDX models of LBC with acquired resistance to endocrine therapies show a great diversity of resistance phenotype, associated with specific deregulations of ER-mediated gene transcription. These models offer a tool for developing anticancer therapies and to investigate the dynamics of resistance emerging during pharmacologic interventions. Clin Cancer Res; 20(16); 4314–25. ©2014 AACR.

Supplementary Table S7. Upstream regulators identified by the Upstream Regulator Analysis in HBCx22 TamR and HBCx34 TamR xenografts.

— Bovine nodular thelitis in dairy cows is a chronic and enzootic infection. Four stages were distinguished: early stage, evolutive stage, ulcerative stage and final stage. Lesions were located mainly in the lower part of the udder or on the teat and recognized as solid papules and nodules. The histopathological study revealed a tuberculoid granulomatous pattern characterized by a subacute focal dermatitis with lymphoid cells, macrophages, epitheloid cells and a variable number of multinucleate giant cells (Langhans type) but no necrosis. Acid-fast bacilli were demonstrated in two of 14 cases. Three strains of acid fast bacilli were isolated but the only one identified was Mycobacterium terrae. M. terrae is a non-pathogenic slowly growing, non-photochromogenic mycobacterium. Its role in tuberculosis-like skin lesion is the bovine udder is uncertain. Resume— La thelite nodulaire est une infection chronique et enzootique chez les vaches laitieres. On distingue 4 phases: une phase precoce, une phase evolutive, une phase ulcerative et une phase finale. Vingt echantillons histologiques, mammelles et trayons, ont ete examines. Les lesions etaient localisees essentiellement a la partie basse de la mammelle ou sur le trayon et se presentaient sous l'aspect de papules solides ou de nodules. Les echantillons etaient divises en deux parties: l'une destinee a l'isolement de mycobacteries, l'autre a l'examen histologique. Les lesions histologiques des trayons etaient des granulomes tuberculoides, caracterises par une dermatite subaigue focale avec presence de lymphocytes, macrophages, cellules epithelioides et une nombre variable de cellules multinucleees geantes (type Langhans). Les infiltrats inflammatoires etaient principalement perivasculaires. Parfois, ils infiltraient toute la paroi du trayon. Aucune necrose n'a ete observee. Des bacilles acidoalcooloresistants furent mis en evidence de maniere inconstante (2 cas sur 14). Trois types de bacilles acidoalcooloresistants ont ete isoles raais, un seul a ete identifie comme etant Mycobacterium terrae. M. terrae est une mycobacterie non pathogene, de croissance lente et non photochromogene. L'implication de cet organisme dans les lesions de type tuberculeux dans la mammelle de la vache est discutee. Zusammenfassung— Bei Milchkuhen stellt die bovine nodulare Thelitis eine chronische und enzootische Infektion dar. Vier Stadien lassen sich unterscheiden: Frustadium evolutorisches Stadium, ulzeratives Stadium und Endstadium. 20 pathologische Proben von Euter und Zitzen wurden untersucht. Die Veranderungen waren hauptsachlich am unteren Teil des Euters oder an den Zitzen lokalisiert und liesen sich als solide Papeln oder Knoten ansprechen. Das Untersuchungsgul wurde fur die Isolierung von Mykobakterien und fur eine histopathologische Untersuchung geteilt. Die histopathologischen Veranderungen der Zitzen zeigten ein tuberkuloides granulomatoses Bild, das durch subakute fokale Dermatitis mit lymphyoiden Zellen, Makrophagen, Epitheloidzellen und einer variablen Anzahl von vielkernigen Riesenzellen (Langhans-Typ) gekennzeichnet war. Die entzundlichen Infiltrate befanden sich hauptsachlich perivaskular. Manchmal liesen sie sich aber auch in der gesamten Zitzenwand nachweisen. Nekrosen bestaznden nicht. Saurefeste Bazillus-Keime waren inkonstant vorhanden (2 von 14 Fallen). Drei Arten von saurefesten Bazillus-Keimen wurden isoliert, aber nur eine wurde speziell identifiziert (Mycobacterium terrae). M. terrae ist ein nicht pathogenes, langsam wachsendes und nich photochromogenes Mykobakterium. Die Beteiligung dieses Organismus bei den tuberkulose-ahnlichen Hautveranderungen am bovinen Euter wird diskutiert. Resumen La Telitis Nodular Bovina es una infeccion enzootica cronica de las vacas lecheras. Se distinguen cuatro etapas: etapa inicial, etapa evolutiva, etapa ulcerativa y etapa final. En el presente trabajo se examinaron 20 muestras de mama y de pezon. Las lesiones se localizaban principalmente en la parte inferior de la glandula mamaria o en el pezon y consistian en papulas solidas y en nodulos. Las muestras se dividian en dos partes, una para el aislamiento de micobacterias y la otra para los estudios histopatologicos. Las lesiones histopatologicas consistian en una reaccion granulomatosa de tipo tuberculoide, caracterizada por una dermatitis focal subaguda con celulas linfoides, macrofagos, celulas epitelioides y un numero variable de celulas gigantes multinucleadas (tipo Langhans). Los infiltrados inflamatorios estaban localizados predominantemente en la zone perivascular. En ocasiones, aparecian a lo largo de toda la pared de la glandula mamaria. No se observo necrosis. Se han aislado tres cepas de bacilos acido-alcohol resistentes, pero solo una fue identificada especificamente como Mycobacterium terrae. M. Terrae es una micobacteria no fotocromogenica de crecimiento lento y no patogena. Se discute la posible participacion de este microorganismo en la genesis de las lesiones pseudotuberculosas observadas en estos animales.

The success of treatment of advanced non-small-cell lung cancer (NSCLC) remains very poor. The aim of this study was, on a series of NSCLC xenografts, to compare the efficacy of standard cisplatin-based or docetaxel-based chemotherapy. Seven human xenografts were obtained from six patients (two xenografts were derived from primary or metastatic tumors of the same patient). Three xenografts were adenocarcinomas and four were squamous cell carcinomas. All xenografts reproduced the same histology as that of the patient's original tumor. Docetaxel, administered as single-agent chemotherapy, induced a significant response in five of the seven NSCLC xenografts (71%), without significant increase after combination with cisplatin, vinorelbine, or gemcitabine. Relative expression of genes putatively involved in drug response was also studied in all xenografts and did not explain the variability of drug sensitivity. In conclusion, this panel of human NSCLC xenografts reliably reproduces the data obtained in patient tumors and the relative sensitivity to docetaxel reported in NSCLC patients.

Histiocytic sarcoma is the most frequent hematopoietic tumor in rats. We report here a histiocytic sarcoma infiltrating the liver, the spleen and the pancreas from a Wistar rat. In the liver, the tumor was associated with oval cell and bile duct hyperplasia. The cells looked like neoplastic histocytic cells described in this species but with some particularities (e.g. lack of multinucleated giant cells). At immunohistochemistry, neoplastic cells in the liver were vimentine positive but lysozyme and CD68 negative. In the kidney, lysozyme-positive cytoplasmic droplets were observed. We describe here an atypical case of histiocytic sarcoma in the rat and we compare the nature of these neoplastic cells to other species.

International audience; Background: Oestrogen receptor-negative (ER-) breast cancer is intrinsically sensitive to chemotherapy. However, tumour response is often incomplete, and relapse occurs with high frequency. The aim of this work was to analyse the molecular characteristics of residual tumours and early response to chemotherapy in patient-derived xenografts (PDXs) of breast cancer. Methods: Gene and protein expression profiles were analysed in a panel of ER- breast cancer PDXs before and after chemotherapy treatment. Tumour and stromal interferon-gamma expression was measured in xenografts lysates by human and mouse cytokine arrays, respectively. Results: The analysis of residual tumour cells in chemo-responder PDX revealed a strong overexpression of IFN-inducible genes, induced early after AC treatment and associated with increased STAT1 phosphorylation, DNA-damage and apoptosis. No increase in IFN-inducible gene expression was observed in chemo-resistant PDXs upon chemotherapy. Overexpression of IFN-related genes was associated with human IFN-gamma secretion by tumour cells. Conclusions: Treatment-induced activation of the IFN/STAT1 pathway in tumour cells is associated with chemotherapy response in ER- breast cancer. Further validations in prospective clinical trials will aim to evaluate the usefulness of this signature to assist therapeutic strategies in the clinical setting.

A quantitative method for the informative evaluation of teaching activities was devised using a survey from 33 experts. It is based on an evaluation, by students and two peers, of the four steps of the instructional methodology: analysis of training needs, statement of learning objectives, delivery of teaching session, and testing of student performance. Faculty evaluation is optional, and results are strictly confidential. Results of a three-year trial of this protocol at the Alfort veterinary schoolare presented and discussed. Each year the method has been assessed and some changes have been implemented. It is now felt that evaluation questionnaires for lectures and tutorial sessions have been validated, while those for laboratories and clinical teac hing have to be tested through a larger number of settings. A the same time, a change from informative to summative evaluation is under consideration.

A case of peritoneal sclerosing mesothelioma in a 3-year-old German shepherd dog is reported. The dog presented a severe abdominal distension. Cytological examination of the peritoneal fluid revealed anaplastic epithelioid cells. Necropsy findings revealed an irregular-shaped mass attached to the pancreas and stomach with numerous nodules covering the intestinal and urinary bladder serosa. The diagnosis was made by histology and immunohistochemistry, with cytokeratin, vimentin and calretinin antibodies. Differential diagnosis with chronic peritonitis and spreading of abdominal primary carcinoma is discussed.

The freshwater cyanobacterium Cylindrospermopsis raciborskii is known to produce toxic effects in several countries. Acute and chronic exposures to C. raciborskii in Australia have been linked to liver damage (hepatotoxicity) with concomitant effects on the kidneys, adrenal glands, small intestine, lungs, thymus, and heart. The alkaloid cylindrospermopsin, which produces these toxic effects, is thought to be a potent inhibitor of protein synthesis. C. raciborskii strains producing cylindrospermopsin or analogue alkaloids have also been reported in Florida, USA, and Thailand. Brazilian isolates of C. raciborskii are also toxic but act by a different mechanism, causing acute death in mice with neurotoxic symptoms similar to those induced by the saxitoxins. In this article we compare the toxicity in the mouse of a C. raciborskii French strain with C. raciborskii strains from various other sources (Australia, Brazil, Mexico, and Hungary). We tested the toxicity of cell extracts by a mouse bioassay. Acute, fatal neurotoxicity was produced by the Brazilian strain, which was confirmed by liquid chromatography with fluorescence detection of the cell extracts, which revealed the presence of saxitoxin, neosaxitoxin, and decarbamoylsaxitoxin, along with two unidentified compounds. Acute hepatotoxicity with severe liver, kidney, and thymus damage was observed with the Australian cylindrospermopsin-producing strain. The Mexican and Hungarian strains were not found to be toxic to mice in our experimental conditions. No animals died after exposure to the extracts of the French C. raciborskii strain. Histological examination of the liver revealed moderate, multifocal necrosis characterized by small areas of hepatocellular necrosis, combined with disorganization of the parenchyma and congestion of the inner sinusoid. These symptoms and lesions resembled those induced by cylindrospermopsin, but the chemical analysis performed by liquid chromatography coupled with either a diode array detector or a mass spectrometer demonstrated that this toxin was not present in our culture extract.

In vitro studies suggested that sub-millisecond pulses of radiation elicit less genomic instability than continuous, protracted irradiation at the same total dose. To determine the potential of ultrahigh dose-rate irradiation in radiotherapy, we investigated lung fibrogenesis in C57BL/6J mice exposed either to short pulses (≤ 500 ms) of radiation delivered at ultrahigh dose rate (≥ 40 Gy/s, FLASH) or to conventional dose-rate irradiation (≤ 0.03 Gy/s, CONV) in single doses. The growth of human HBCx-12A and HEp-2 tumor xenografts in nude mice and syngeneic TC-1 Luc(+) orthotopic lung tumors in C57BL/6J mice was monitored under similar radiation conditions. CONV (15 Gy) triggered lung fibrosis associated with activation of the TGF-β (transforming growth factor-β) cascade, whereas no complications developed after doses of FLASH below 20 Gy for more than 36 weeks after irradiation. FLASH irradiation also spared normal smooth muscle and epithelial cells from acute radiation-induced apoptosis, which could be reinduced by administration of systemic TNF-α (tumor necrosis factor-α) before irradiation. In contrast, FLASH was as efficient as CONV in the repression of tumor growth. Together, these results suggest that FLASH radiotherapy might allow complete eradication of lung tumors and reduce the occurrence and severity of early and late complications affecting normal tissue.

Purpose: Patients with luminal breast cancer (LBC) often become endocrine resistant over time. We investigated the molecular changes associated with acquired hormonoresistances in patient-derived xenografts of LBC. Experimental Design: Two LBC xenografts (HBCx22 and HBCx34) were treated with different endocrine treatments (ET) to obtain xenografts with acquired resistances to tamoxifen (TamR) and ovariectomy (OvaR). PI3K pathway activation was analyzed by Western blot analysis and IHC and responses to ET combined to everolimus were investigated in vivo. Gene expression analyses were performed by RT-PCR and Affymetrix arrays. Results: HBCx22 TamR xenograft was cross-resistant to several hormonotherapies, whereas HBCx22 OvaR and HBCx34 TamR exhibited a treatment-specific resistance profile. PI3K pathway was similarly activated in parental and resistant xenografts but the addition of everolimus did not restore the response to tamoxifen in TamR xenografts. In contrast, the combination of fulvestrant and everolimus induced tumor regression in vivo in HBCx34 TamR, where we found a cross-talk between the estrogen receptor (ER) and PI3K pathways. Expression of several ER-controlled genes and ER coregulators was significantly changed in both TamR and OvaR tumors, indicating impaired ER transcriptional activity. Expression changes associated with hormonoresistance were both tumor and treatment specific and were enriched for genes involved in cell growth, cell death, and cell survival. Conclusions: PDX models of LBC with acquired resistance to endocrine therapies show a great diversity of resistance phenotype, associated with specific deregulations of ER-mediated gene transcription. These models offer a tool for developing anticancer therapies and to investigate the dynamics of resistance emerging during pharmacologic interventions. Clin Cancer Res; 20(16); 4314–25. ©2014 AACR.

The kinetics of infection and the pathogenic effects on the reproductive function of laboratory mice infected withBartonella birtlesiirecovered from anApodemusspecies are described.B. birtlesiiinfection, as determined by bacteremia, occurred in BALB/c mice inoculated intravenously. Inoculation with a low-dose inoculum (1.5 × 103CFU) induced bacteremia in only 75% of the mice compared to all of the mice inoculated with higher doses (≥1.5 × 104). Mice became bacteremic for at least 5 weeks (range, 5 to 8 weeks) with a peak ranging from 2 × 103to 105CFU/ml of blood. The bacteremia level was significantly higher in virgin females than in males but the duration of bacteremia was similar. In mice infected before pregnancy (n= 20), fetal loss was evaluated by enumerating resorption and fetal death on day 18 of gestation. The fetal death and resorption percentage of infected mice was 36.3% versus 14.5% for controls (P< 0.0001). Fetal suffering was evaluated by weighing viable fetuses. The weight of viable fetuses was significantly lower for infected mice than for uninfected mice (P< 0.0002). Transplacental transmission ofBartonellawas demonstrated since 76% of the fetal resorptions tested was culture positive forB. birtlesii. The histopathological analysis of the placentas of infected mice showed vascular lesions in the maternal placenta, which could explain the reproductive disorders observed. BALB/c mice appeared to be a useful model for studyingBartonellainfection. This study provides the first evidence of reproductive disorders in mice experimentally infected with aBartonellastrain originating from a wild rodent.

Villin is an actin-binding protein localized in intestinal and kidney brush borders. In vitro, villin has been demonstrated to bundle and sever F-actin in a Ca2+-dependent manner. We generated knockout mice to study the role of villin in vivo. In villin-null mice, no noticeable changes were observed in the ultrastructure of the microvilli or in the localization and expression of the actin-binding and membrane proteins of the intestine. Interestingly, the response to elevated intracellular Ca2+ differed significantly between mutant and normal mice. In wild-type animals, isolated brush borders were disrupted by the addition of Ca2+, whereas Ca2+ had no effect in villin-null isolates. Moreover, increase in intracellular Ca2+ by serosal carbachol or mucosal Ca2+ ionophore A23187 application abolished the F-actin labeling only in the brush border of wild-type animals. This F-actin disruption was also observed in physiological fasting/refeeding experiments. Oral administration of dextran sulfate sodium, an agent that causes colonic epithelial injury, induced large mucosal lesions resulting in a higher death probability in mice lacking villin, 36 ± 9.6%, compared with wild-type mice, 70 ± 8.8%, at day 13. These results suggest that in vivo, villin is not necessary for the bundling of F-actin microfilaments, whereas it is necessary for the reorganization elicited by various signals. We postulate that this property might be involved in cellular plasticity related to cell injury.

Eight heifers were orally infected with 4 x 10(9) colony forming units of a field cattle strain of Yersinia enterocolitica O:9 in a capsule, 5 days a week, for about 9 weeks (day 0-day 64 (D0-D64). The faecal shedding of Y. enterocolitica O:9 began on D5 for seven out of the eight challenged cattle with a high level of excretion during the first month, followed by a decrease till the day of slaughter (D76). Y. enterocolitica O:9 was not isolated from organs collected at slaughter. No clinical symptoms were observed. Hyperplasia of intestinal lymph formations was the sole microscopic lesions observed. Five animals showed a serological reaction against Brucella antigens in at least one of the following tests: Rose-Bengal test, complement fixation test, tube agglutination test or indirect ELISA (iELISA) tests. Only one animal showed a high level of serological response and a positive reaction in the dithiothreitol-microagglutination test. The observed variability in terms of individual sensitivity to the Y. enterocolitica O:9 infection is in agreement with the low individual prevalence rate and the transient serological reaction and faecal Y. entercolitica O:9 shedding observed in herds showing false positive serological reactions in brucellosis.

Metabolic adaptations and changes in the expression of nutrient transporters are known to accompany tumorigenic processes. Nevertheless, in the context of solid tumors, studies of metabolism are hindered by a paucity of tools allowing the identification of cell surface transporters on individual cells. Here, we developed a method for the dissociation of human breast cancer tumor xenografts combined with quantification of cell surface markers, including metabolite transporters. The expression profiles of four relevant nutrient transporters for cancer cells' metabolism, Glut1, ASCT2, PiT1 and PiT2 (participating to glucose, glutamine and inorganic phosphate, respectively), as detected by new retroviral envelope glycoprotein-derived ligands, were distinctive of each tumor, unveiling underlying differences in metabolic pathways. Our tumor dissociation procedure and nutrient transporter profiling technology provides opportunities for future basic research, clinical diagnosis, prognosis and evaluation of therapeutic responses, as well as for drug discovery and development.Laboratory Investigation advance online publication, 4 March 2013; doi:10.1038/labinvest.2013.44.

International audience; ABSTRACT: INTRODUCTION: Identification of new therapeutic agents for breast cancer (BC) requires preclinical models that reproduce the molecular characteristics of their respective clinical tumors. In this work, we analyzed the genomic and gene expression profiles of human BC xenografts and the corresponding patient tumors. METHODS: Eighteen BC xenografts were obtained by grafting tumor fragments from patients into Swiss nude mice. Molecular characterization of patient tumors and xenografts was performed by DNA copy number analysis and gene expression analysis using Affymetrix Microarrays. RESULTS: Comparison analysis showed that 14/18 pairs of tumors shared more than 56% of copy number alterations (CNA). Unsupervised hierarchical clustering analysis showed that 16/18 pairs segregated together, confirming the similarity between tumor pairs. Analysis of recurrent CNA changes between patient tumors and xenografts showed losses in 176 chromosomal regions and gains in 202 chromosomal regions. Gene expression profile analysis showed that less than 5% of genes had recurrent variations between patient tumors and their respective xenografts; these genes largely corresponded to human stromal compartment genes. Finally, analysis of different passages of the same tumor showed that sequential mouse-to-mouse tumor grafts did not affect genomic rearrangements or gene expression profiles, suggesting genetic stability of these models over time. CONCLUSIONS: This panel of human BC xenografts maintains the overall genomic and gene expression profile of the corresponding patient tumors and remains stable throughout sequential in vivo generations. The observed genomic profile and gene expression differences appear to be due to the loss of human stromal genes. These xenografts therefore represent a validated model for preclinical investigation of new therapeutic agents.

Triple-negative breast cancers (TNBC) have an aggressive phenotype with a relatively high rate of recurrence and poor overall survival. To date, there is no approved targeted therapy for TNBCs. Aurora kinases act as regulators of mammalian cell division. They are important for cell-cycle progression and are frequently overexpressed or mutated in human tumors, including breast cancer. In this study, we investigated the therapeutic potential of targeting Aurora kinases in preclinical models of human breast cancers using a pan-inhibitor of Aurora kinases, AS703569. In vitro, AS703569 was tested in 15 human breast cancer cell lines. TNBC cell lines were more sensitive to AS703569 than were other types of breast cancer cells. Inhibition of proliferation was associated with cell-cycle arrest, aneuploidy, and apoptosis. In vivo, AS703569 administered alone significantly inhibited tumor growth in seven of 11 patient-derived breast cancer xenografts. Treatment with AS703569 was associated with a decrease of phospho-histone H3 expression. Finally, AS703569 combined to doxorubicin–cyclophosphamide significantly inhibited in vivo tumor recurrence, suggesting that Aurora kinase inhibitors could be used both in monotherapy and in combination settings. In conclusion, these data indicate that targeting Aurora kinases could represent a new effective approach for TNBC treatment. Mol Cancer Ther; 11(12); 2693–703. ©2012 AACR.

Androgen-dependent and castration-resistant prostate cancer (PC) is usually sensitive to docetaxel chemotherapy. Nevertheless, docetaxel resistance frequently appears after several cycles of treatment, raising the problem of salvage treatment for docetaxel-resistant PC patients. Although the combination of docetaxel and estramustine prolongs metastasis-free and overall survival of patients with androgen-independent PC, the use of this modality remains limited in elderly patients or patients with several comorbidities, especially vascular disease or gastrointestinal toxicity, because of unacceptable toxicity including venous thrombosis. The aims of this study were therefore (i) to evaluate the in-vivo efficacy of estramustine combined with docetaxel since initial tumor growth and following the appearance of docetaxel resistance in the androgen-dependent human PC xenograft PAC120, and (ii) to evaluate the efficacy of estramustine in six human androgen-independent PC models derived from PAC120. In docetaxel-resistant tumor-bearing mice, estramustine alone induced a TGD2 of 18 days, whereas the combination of docetaxel and estramustine induced a TGD2 of 50 days (P

We report herein a feline salivary gland adenocarcinoma with widespread metastases to draining lymph nodes, liver and lung, as well as an unusual metastasis to the spleen. Histologically, the primary salivary gland tumor consisted of low columnar to polygonal epithelial cells forming tubules and trabeculae. The spleen was infiltrated with sheets of poorly differentiated large round cells. Interestingly, morphologic change in epithelial cells was accompanied with the acquisition of vimentin intermediate filaments, a feature particularly evident in the splenic metastasis. This study highlights the role of epithelial cell plasticity during carcinogenesis and metastasis.

Chantier qualité GA; Gastro-intestinal Stromal Tumors (GIST) are digestive mesenchymal tumors. These rare tumors in Humans remain seldom diagnosed in veterinary medicine. Traditionally regarded as deriving from smooth muscle cells or Schwann cells, GIST are now recognized as a specific tumoral entity. They derive from interstitial cells of Cajal, pacemakers of the digestive tract. Their diagnosis is based on histological and immunohistochemical characteristics. They are immunohistochemically KIT-positive (a transmembrane tyrosine kinase receptor) and are often associated with mutations of the Kit gene. KIT is responsible for the development of new therapeutic molecules: tyrosine kinase inhibitors. In humans, these molecules have revolutionized the treatment of GIST, particularly resistant to radiotherapy and chemotherapy. In animals, tyrosine kinase inhibitors represent an important breakthrough that will allow interesting new therapeutic treatments.; Les gastro-intestinal stromal tumors (GIST) sont des tumeurs mésenchymateuses digestives. Ces tumeurs rares en pathologie humaine restent peu diagnostiquées en médecine vétérinaire. Longtemps considérées comme des tumeurs dérivées des fibres musculaires lisses ou des cellules de Schwann, les GIST sont aujourd’hui reconnues comme une entité tumorale à part entière. Elles dériveraient des cellules interstitielles de Cajal, pacemakers du tube digestif. Leur diagnostic repose sur des critères histologiques et immunohistochimiques. Elles sont caractérisées par un immunomarquage positif pour la protéine KIT (récepteur à activité tyrosine kinase) et souvent associées à des mutations du gène Kit. L’implication de KIT a contribué au développement d’approches thérapeutiques basées sur l’utilisation d’inhibiteurs de tyrosine kinase. Chez l’Homme, ils ont révolutionné le traitement des GIST, connues pour être résistantes à la radiothérapie et la chimiothérapie. Leurs propriétés ouvrent de nouvelles perspectives thérapeutiques chez l’animal.

The central nervous system (CNS) represents an important target organ of the phocine distemper virus (PDV). The aim of the present study was to characterize pathological changes in the CNS of harbor seals suffering from natural PDV-infection. The distribution of virus protein and mRNA was investigated by immunohistochemistry (IHC) and in situ hybridization, respectively. In addition, inflammatory and glial cells were characterized by IHC. Polioencephalitis with glial activation, neuronal death and perivascular mononuclear infiltrations in the cerebral cortex was the main histopathological finding. Inflammatory responses, dominated by CD3(+) T-cells and activated microglia/macrophages were associated with a prominent MHC-II upregulation within the CNS. Viral protein was found predominantly in neurofilament-expressing neurons within inflamed areas as demonstrated by immunohistochemical double-labeling. Morbillivirus nucleo-, phospho-, matrix-, fusion- and hemagglutinin-proteins were found in CNS-lesions. The expressions of viral matrix- and fusion-proteins were reduced in severely inflamed plaques. Comparison of viral protein and mRNA expression revealed a diminished amount of viral phosphoprotein preferentially associated with perivascular inflammation. In summary, CNS-lesions in PDV-infected seals are similar to canine distemper virus-induced acute polioencephalitis in dogs and measles virus inclusion body polioencephalitis in men, respectively.

This case describes a subcutaneous soft tissue tumour in a German Shepherd dog. Histologically, the lesion was characterized by proliferating ovoid cells, loosely arranged in a collagenous to myxoid stroma, and by numerous pseudoglandular structures lined by neoplastic cells. Immunohistochemically, neoplastic cells were labelled with vimentin, glial fibrillary acidic protein and S100 antibodies, but not with cytokeratin, desmin and smooth muscle actin antibodies. Ultrastructurally, neoplastic cells were characterized by numerous mitochondria surrounded by endoplasmic reticulum and contained few secondary lysosomes. This tumour was diagnosed as a subcutaneous peripheral nerve sheath tumour (PNST) with pseudoglandular architecture. This case illustrates the morphological diversity of PNST and provides new insight into the differential diagnosis of cutaneous tumours of similar morphology in the dog.

Chronic and subchronic toxicity resulting from exposure to microcystins (MCs) receives increasing attention due to the risk of bioaccumulation of these toxins by aquatic animals, including fish. The mechanisms of action of MCs that target the liver, involve modifications of protein phosphorylation resulting from phosphatases 1 and 2A inhibition. Therefore, studying phosphoprotein modifications by using a specific phosphoprotein stain Pro-Q Diamond in fish liver contaminated with MC-leucine-arginine (MC-LR), the most toxic MC, should help dissecting disturbed signaling and metabolic networks. We have recently used this technology to identify several proteins that are modulated either in expression or phosphorylation in the liver of medaka following short-term exposure to MC-LR by balneation. In the present study, we have decided to use an alternative way of introducing the toxin into fish; that is by gavage (force-feeding). This was first achieved using tritiated MC-LR and allowed us to quantify the quantity of toxin incorporated into fish and to demonstrate that the toxin is mainly accumulated in liver. Afterwards a proteomics study limited to liver cytosolic proteins of contaminated animals showed that several proteins were up or down regulated either in quantity or in phosphorylation or both. Some of them had been previously detected as modified in balneation experiments but new molecules were identified as involved in signal transduction pathways activated by the toxin. In addition, in the conditions used (5 microg toxin/g body weight) anatomopathological studies supported a process of apoptonecrosis established after 24h, which was suggested to proceed by the evolution of some of the proteins after 2h contamination.

A hepatic mass was identified in a 5-year-old, female mixed-breed cat that died spontaneously after a clinical history of progressive emaciation, ptyalism, and persistent coryza. At necropsy, a 7-cm-diameter, yellow-brown, firm, multilobulated tumor was identified in the liver. Microscopically, the mass consisted of neoplastic cells arranged in small, closely packed nests within a thin fibrovascular stroma. These cells were of medium sized and polygonal, with fine argyrophilic cytoplasmic granules. Nuclei were predominantly round with finely stippled chromatin and indistinct nucleoli. Mitotic figures were numerous. Immunohistochemically, most of the neoplastic cells were immunoreactive for chromogranin A, neuron-specific enolase (NSE), and cytokeratin AE1/AE3 and weakly labeled for synaptophysin. The tumor was negative for glial fibrillary acidic protein (GFAP), vimentin, and cytokeratins 5, 6, 8, and 17. Vascular emboli and intrahepatic micrometastasis were also identified with chromogranin A. All these features were consistent with a hepatic neuroendocrine carcinoma and emphasized the importance of using a panel of antibodies to diagnose such rare tumors.

Mammary gland adenomyoepitheliomas are benign complex mammary gland tumors composed of neoplastic cells of epithelial and myoepithelial origins, described in many species (humans, dogs, cats, rats) and rarely in mice. We report here an adenomyoepithelioma in a C57BL/6 female mouse. Histologically, tubes and cords formed by neoplastic epithelial cells were separated by bundles of neoplastic myoepithelial cells in a clear and partially mucinous matrix. The tumor displayed characteristics of a benign neoplastic proliferation with a compressive growth pattern, and moderate cellular pleomorphism and mitotic index. At immunohistochemistry, the epithelial cells were strongly cytokeratin positive; the myoepithelial cells were weakly cytokeratin positive and strongly smooth muscle actin positive. This is to our knowledge, the first report of a mammary gland adenomyoepithelioma in a C57BL/6 mouse.

International audience; Experimental aspergillosis was obtained in 15 one-day-old turkeys by intra-air sac inoculation of a spore suspension of 3-day-old A. fumigatus culture (CBS 144.89) containing 107 spores. Ten additional turkey poults were used as controls. Infected and non-infected animals were closely observed at least twice a day for the appearance of clinical signs and were sequentially sacrificed at days 1, 2, 3, 5 and 7 post-inoculation. In the infected group, most lung tissues and air sac swabs were culture positive from day 1 to day 5. One day post-inoculation, air sac membranes were multifocally and moderately to severely thickened by an edema and covered by an exudate. A small number of germinating conidia was present in the superficial exudate, giving already rise to small radiating hyphae. Lung lesions were mild, dominated by a diffuse congestion and a mild hererophilic infiltration. From two to 3 days post-inoculation, air sac membranes were more severely affected and several granulomas were observed. Both granulomas and exudates were rich in germinated conidia and hyphae. Pulmonary lesions consisted in a diffuse pneumonia. Five days post-inoculation, lesions of the air sac membranes progressed to a severe, multifocal, heterophilic and granulomatous inflammation. Seven days post-inoculation, a reduction of the severity of the diffuse pneumonia was detected. Concomitantly, the fungal elements were mainly observed as fragmented tubules in the cytoplasm of multinucleate giant cells. The present study demonstrated that healthy turkey poults might be able to withstand exposure to 107 A. fumigatus spores.

Necrotizing encephalitis of the Yorkshire terrier is a chronic non-suppurative encephalitis that was reported in approximately 15 cases worldwide. We report the case of a 10-year-old female Yorkshire terrier with gross evidence of severe cortical degeneration and necrosis. Microscopically, affected areas were mainly located in the cortical white matter and in the mesencephalon without implication of the cerebellum. Cavitation necrosis, demyelination, gemistocytic astrocytosis, marked perivascular lymphocytic cuffing with a diffuse lymphocytic/histiocytic/gitter cell infiltration characterized the lesions. Immunohistochemical analysis identified the major infiltration of T lymphocytes and macrophages with implication of some cytotoxic lymphocytes and IgG-producing plasma cells; depositions of IgG in the affected white matter were also observed. Specific stains did not reveal fungal, protozoal or bacterial organisms and reverse transcriptase-polymerase chain reaction analysis for distemper virus was also negative. The lympho-histiocytic inflammation suggests a T-cell-mediated and a delayed-type immune reaction as a possible pathogenic mechanism for this brain disorder.

International audience; Conjugated linoleic acids (CLAs) consist of a series of positional and geometrical isomers of linoleic acid. CLA have been reported to beneficially affect cardiovascular risk factors in animal models. In order to assess the role of individual CLA isomers on lipoprotein cholesterol concentration, 30 hamsters were fed for 12 weeks an hyperlipidic diet containing pure cis-9,trans-11 CLA (c9,t11) or pure trans-10, cis-12 CLA (t10,c12) isomers given alone or as a mixture. Plasma total cholesterol, LDL and HDL cholesterol concentrations were significantly lower in the c9,t11 CLA isomer fed hamsters relative to the Control group, with the most substantially effect on LDL cholesterol (-56%; P < 0.05). Plasma triacylglycerol concentrations did not differ significantly regarding those two groups. Plasma cholesterol parameters showed a tendency to decrease in the t10,c12 CLA isomer and CLA mixture fed hamsters compared with the Control group, but differences were not significant. For the first time, the atherogenic fraction of small dense LDL was investigated. Plasma small dense LDL cholesterol concentration was lower in the c9,t11 CLA relative to Control, while the t10,c12 and CLA mixture groups showed only a non significant tendency to decrease. Taken together, these data indicate that feeding rumenic acid (c9,t11 CLA) may beneficially affect lipoprotein profile in hamster fed a cholesterol- and lipid-enriched semi-purified diet, when t10,c12 CLA isomer or CLA mixture would be less active.

SIR, – One of the concerns about BSE is the potential presence of the agent in small ruminants, sheep and goats, as well as cattle. With the objective of documenting this, seven French laboratories have analysed 438 brain samples from confirmed cases of TSE in sheep and goats. These comprised

The cyanobacterial hepatotoxin microcystin-LR (MC-LR) is a specific potent PP1 and PP2A protein phosphatase inhibitor. In view to obtain an integrated whole-body, understanding of the key target organs of MC-LR subsequent to embryonic exposure on the anatomy of medaka fish hatchlings, embryos at stage 19 were microinjected with a sublethal dose of MC-LR corresponding to 0.2 pg/vitellus. MC-LR-induced histo-pathological modifications of the alimentary system (i.e. digestive tract, pancreas, liver) were analysed in newly hatched embryos. Our data are indicative of an MC-LR-induced inhibition of both yolk sac resorption and gas concentrating swimbladder expansion. In contrast to control hatchlings, (i) no mucus-secreting cells in the oesophagus, (ii) a decreased folding of the stomach and intestine, (iii) a clear reduction in size of the exocrine pancreas associated with a destructuration of acinar units, and (iv) a strong decrease in the mass and size of the liver were observed in MC-LR treated embryos. Furthermore, as an indication of MC-LR-induced hepatic glycogen store depletion, unstained cytoplasmic areas present in control hatchling hepatocytes, were fully absent in all liver examined in treated embryos. Finally, as a general observation in MC-LR-treated embryos, our data clearly indicated terminal differentiation disorders in all organs associated with the digestive tract.

Summary Osteoid malignant melanoma is a rare type of melanoma described in humans and dogs with some areas of bone differentiation. In this tumour, the origin of the bone matrix remains unclear. We report one case of this variant with, for the first time, a cutaneous origin in a dog. Malignant melanomas are aggressive tumours. Amelanotic tumours are sometimes difficult to recognize as they require immunohistochemical evaluation for an adequate diagnosis and we have used anti-vimentin, S100, and melan A antibodies for identification. Melan A is less sensitive but more specific than S100 in identifying amelanotic melanomas. This tumour was positive for vimentin, S100 and melan A, including the areas of osteoid. These results suggest osteoid differentiation of tumour cells rather than induced stromal metaplasia.

We have investigated the mechanisms by which the epithelial apicolateral junctional complex (AJC) is generated during trophectoderm differentiation in the mouse blastocyst using molecular, structural and functional analyses. The mature AJC comprises an apical tight junction (TJ), responsible for intercellular sealing and blastocoel formation, and subjacent zonula adherens E-cadherin/catenin adhesion complex which also extends along lateral membrane contact sites. Dual labelling confocal microscopy revealed that the AJC derived from a single 'intermediate' complex formed following embryo compaction at the 8-cell stage in which the TJ-associated peripheral membrane protein, ZO-1alpha- isoform, was co-localized with both alpha- and beta-catenin. However, following assembly of the TJ transmembrane protein, occludin, from the early 32-cell stage when blastocoel formation begins, ZO-1alpha- and other TJ proteins (ZO-1alpha+ isoform, occludin, cingulin) co-localized in an apical TJ which was separate from a subjacent E-cadherin/catenin zonula adherens complex. Thin-section electron microscopy confirmed that a single zonula adherens-like junctional complex present at the AJC site following compaction matured into a dual TJ and zonula adherens complex at the blastocyst stage. Embryo incubation in the tracer FITC-dextran 4 kDa showed that a functional TJ seal was established coincident with blastocoel formation. We also found that rab13, a small GTPase previously localized to the TJ, is expressed at all stages of preimplantation development and relocates from the cytoplasm to the site of AJC biogenesis from compaction onwards with rab13 and ZO-1alpha- co-localizing precisely. Our data indicate that the segregation of the two elements of the AJC occurs late in trophectoderm differentiation and likely has functional importance in blastocyst formation. Moreover, we propose a role for rab13 in the specification of the AJC site and the formation and segregation of the TJ.

Background. Activation of the PI3K pathway is associated with resistance to endocrine treatments (ET) in luminal breast cancer (LBC). Everolimus, an mTOR inhibitor, has been approved in combination with exemestane in endocrine resistant breast tumors. However, no definite signature of ET resistance or predictive factors of sensitivity to everolimus (EVE) treatment have been evidenced so far. In order to further decipher these molecular patterns, we used patient derived LBC xenografts (LBC-PDX) treated with various ET and EVE based combinations. Methods. 3 LBC-PDX (named HBCx-3, HBCx-21 and HBCx-34) were treated with ET during several months to establish hormono-resistant (HR) xenografts. Both parental and HR models were treated by tamoxifen, estrogen deprivation, fulvestrant, EVE alone, and EVE combined with all three ET modalities. Tissue Micro Arrays from control and treated tumor samples were generated for IHC analyses. RT-PCR analyses were conducted on genes related to proliferation, ER, PI3K, IGF-1R and angiogenesis pathways. Results. In primary PDX, ET showed a poor level of sensitivity for HBCx-3 and a high and sustained efficacy of ER targeting and/or ER deprivation for HBCx-21 and HBCx-34 tumors. In vivo resistance to ET was confirmed in all HR variants with tumor growth rates faster than parental xenografts. ER expression was conserved in HR tumors, but expression of the ER-responsive genes PS2, PR and MYB was strongly decreased, indicating impaired ER transcriptional activity. Acquired resistance to tamoxifen and ovariectomy was also associated to a strong decrease of IGF-1R signaling in HBCx-21, and was related to higher P-AKT expression, although P-pS6 was highly expressed in both sensitive and resistant tumors. Furthermore, in vivo experiments showed that EVE alone was highly efficient in all models independently of P-AKT expression/PTEN loss. EVE combined with fulvestrant yielded the most complete and durable tumor growth inhibition. In HBCx-3, proliferation and pS6 levels were markedly decreased only by the EVE-fulvestrant combination. In HBCx-21 and HBCx-34 HR models, EVE-based treatments decreased proliferation, expression of angiogenesis markers, as well as P-pS6 expression with no variation in (P-)AKT nor (P-)mTOR levels. A high IGF-1R protein expression was found only in the HBCx-34 TAM-R tumor, which was strongly decreased in the fulvestrant-treated tumors. Conclusions. LBC-PDX with confirmed HR status have been established and may serve as models to study alternate therapies. Of note, in the HBCx-21 and -34 models, activation of the PI3K pathway is poorly correlated with baseline sensitivity to ET, suggesting other pathways of resistance. EVE alone is highly efficient in all settings, and combination with fulvestrant is promising at the in vivo and molecular levels. Proteomic, genomic and gene expression studies are ongoing. Citation Format: Paul H. Cottu, Thomas Bagarre, Jean-Jacques Fontaine, Franck Assayag, Sophie Richon, Sophie Chateau-Joubert, Aurélie Thuleau, Patricia de Cremoux, Khemaies Slimane, Didier Decaudin, Anne Vincent-Salomon, Ivan Bièche, Elisabetta Marangoni. Endocrine resistant luminal breast cancer xenografts are powerful models for the analysis of sensitivity to endocrine and everolimus treatments . [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 85. doi:10.1158/1538-7445.AM2013-85

Histological responses to the early phase of infection were compared in parotid lymph nodes of lambs infected by the subcutaneous route into the right eyelid with either a virulent or an attenuated strain of Salmonella abortusovis. The right parotid lymph nodes showed a massive PMN infiltration for the first days of infection for both strains. From day 6, the infected lymph nodes developed a lymphoid hyperplasia with prominent germinal centers independent of strain type. The virulent strain of S. abortusovis induced focal lesions in 2 out of 6 lambs necropsied on days 6 and 10, and provoked a systemic infection evidenced by the regular colonization of spleen on day 6. In contrast, no focal lesion and a restricted bacterial dissemination were observed in lambs infected with the vaccinal strain.

Background: Tumor cell metabolism is of growing interest in both basic and clinical cancer research. A better understanding of underlying molecular mechanisms involving metabolite transport in normal and tumor cells should help drug discovery and development. Specific exofacial ligands to metabolite transporters derived from the receptor binding domain (RBD) of retrovirus envelope proteins were developed and used to quantify cell surface metabolite transporters. While cell surface labelling can be readily performed on cultured cell lines, analysis of single cells from solid tumors is more challenging. In this study, we developed a robust method for the disaggregation of tumor cells from human breast cancers grown as xenografts in mice. This procedure was then used to analyse the expression profiles of 4 cell membrane metabolite transporters involved in cell proliferation and tumorigenesis: Glut1, ASCT2, PiT1, and PiT2. Materials and methods: Eight primary human breast cancer xenografts were used for ex vivo experiments (Marangoni et al 2007). We developed an optimized disaggregation protocol to obtain maximum viable cell recovery from the xenografts. The protocol was validated for presence of CD44+ tumor cells and for cell viability using caspase 3 and DAPI exclusion and subsequently, applied to the xenografts for flow cytometry analyses, immunohistochemistry and ex vivo cell culture. Expression profiles of 4 metabolite transporters were assessed in 5 different human breast cancer xenografts. Results: The optimal dissociation protocol developed for these tumors combined mild non-enzymatic (non-enzymatic dissociation buffer) and enzymatic (collagenase III/DNase I) steps, followed by cell purification on a dual density Ficoll gradient. Less than 10% of resulting DAPI negative tumor cells were caspase 3 positive. Dissociated cells showed sustained viability in in vitro cultures for at least 12 days. The numbers of CD44+ cells determined by flow cytometry corresponded to those observed by IHC. The expression profiles of Glut1, ASCT2, PiT1, and PiT2 were distinct for each of the five human breast cancers, and metabolite transporter profiles were highly conserved for xenografts derived from the same tumor. Conclusions: Mouse xenograft implants of human breast cancer tumors were used to optimize and validate a dissociation method for the production of viable single cells. Cell suspensions were then assessed for cell surface metabolite transporters expression by flow cytometry. The expression patterns of four metabolite transporters, Glut1, ASCT2, PiT1, and PiT2 showed distinctive signature profiles for each group of xenografts, indicative of specific metabolic adaptations that can be tracked with our ligands for each tumor. Reference: 1. Marangoni E et al, CCR 2007;13:3989–3998. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr B142.

Background: The treatment of both uveal melanoma and retinoblastoma could require enucleation in unfavorable prognostic disease. In order to allow pharmacological assessment of innovative intraocular treatments in more relevant and predictive models, we have developed preclinical orthotopic xenografts of both primary human uveal melanoma (UM) and retinoblastoma (Rb) into immunodeficient mice. Materials and methods: Orthotopic models of human UM and Rb have been developed from two panels of subcutaneous xenografts previously established and characterized in the laboratory (Némati et al 2010; Aerts et al 2010), i.e. 6 UM models (MP34, MP41, MP42, MP55, MP65, and MM26) and 3 Rb models (RB102, RB111, and RB200). Mice bearing xenografts were sacrificed and tumors were dissected to obtain a suspension of fresh tumor cells at a concentration of 8000 cells/l in DMEM serum-free medium. Under intraperitoneal anesthesia, 2 l of cell suspension was injected into the subretinal space of the right eye for 3 groups of mice using a 32G needle via a Hamilton syringe. Each group was constituted by 3 to 6 SCID mice. After sub-retinal injection, ophthalmic examination of the mice was performed weekly. When tumor cells invaded vitreal cavity and anterior chamber, the mice were sacrificed for ophthalmological pathological analyzes. Finally, using the RB200 model, we have then evaluated the efficacy of 2 μl intraocular administration of bevacizumab (25 mg/kg/week for 4 weeks), melphalan (500 μg/kg/week for 4 weeks), and carboplatin (100 μg/kg/week for 4 weeks). Results: The 6 UM cells developed in all injected eyes, 6 to 10 weeks after orthotopic transplantation. Pathological analyzes confirmed UM diagnosis and conservation of histological sub-type, i.e. epithelioid and/or spindle cell, than in corresponding patient's tumors and subcutaneous xenografts. Liver tissues examination is on-going. Rb tumor cells developed in all injected eyes 4 to 6 weeks after orthotopic transplantation for RB102 and RB200. In contrast, no tumor growth was observed in injected eyes of the RB111 model. Pathological examination of the injected eyes confirmed the presence of a massive infiltration of the retina, vitreous and anterior chamber by retinoblastoma cells. Finally, we have observed a high efficacy of intraocular administration of carboplatin (17% of intraocular tumors), but not bevacizumab (100%) nor melphalan (67%), in the RB200 model than in the control group. Conclusions: We have developed relevant and available preclinical models of human UM and Rb that allow pharmacological assessment of intraocular standard therapies. We will now evaluate innovative therapeutic approaches in such a tumor situation. Némati et al. Clin Cancer Res 2010;16:2352–2362. Aerts et al. Photodiagnosis Photodyn Ther 2010;7:275–283. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr A20.

Introduction: Androgen-dependent prostate cancers (PC) are usually sensitive to docetaxel chemotherapy. Nevertheless, docetaxel-resistance frequently appears after several cycles of treatment, raising the treatment rescue of docetaxel-resistant PC patients. If the combination of estramustine to docetaxel prolongs the metastatic-free and overall survivals of patients with androgen-dependent PC, its use remains limited in patients because of unacceptable toxicity including venous thromboses. The aims of this study were (1) to evaluate the in vivo efficacy of estramustine combined to docetaxel since initial tumor growth and since appearance of docetaxel resistance in one androgen-dependent human PC xenograft, and (2) to evaluate the efficacy of estramustine in six human androgen-independent human PC variants. Experimental procedures: The preclinical models included the androgen-dependent PAC120 tumor obtained from a Gleason-9 primary PC of a 51-years old patient (De Pinieux et al, Am J Pathol, 2001), and six hormone-independent variants derived from PAC120. Docetaxel was administrated at a dosage of 20 mg/kg every three weeks by intraperitoneal injection for at most six cycles, and estramustine was given intraperitoneally at a dosage of 12 mg/kg days 1 to 5 every 3 weeks until mice sacrifice. Tumor volume was measured twice a week and Relative Tumor Volume (RTV) from start of treatment were then calculated. In the PAC120 model, escape to docetaxel was defined at the beginning of each next cycle (n + 1) as a ratio of RTVn+1/RTVn ≥ 2. Resistant mice were then randomized into two groups, one receiving estramustine alone, and the other treated by a combination of docetaxel + estramustine, with an evaluation of the tumor growth delay for a 2-fold tumor size increase from randomisation (TGD2). In the 6 androgen-independent PC xenografts (HID), estramustine administered alone was compared to a control group. Results: Estramustine alone did not induce significant tumor growth inhibition in both PAC120 and HID xenografts. In PAC120 model, tumor growth inhibition (TGI) after docetaxel alone and docetaxel + estramustine was 81% and 95%, with a mean response duration of 29 days [21–63] and 68 days [64–74], respectively (p < 0.05). In docetaxel-resistant tumor bearing mice, estramustine alone induced a TGD2 of 18 days, whereas estramustine + docetaxel induced a TGD2 of 49 days (p < 0.05). Metastatic lesions and venous thromboses into lung of tumor-bearing mice have also been evaluated by histopathological analyses and may be presented during the meeting. Conclusions: Estramustine alone was not efficient in both human androgen-dependent and -independent PC xenografts. Inversely, the combination of estramustine + docetaxel in first treatment line and estramustine added to docetaxel in docetaxel-resistant xenografts was highly effective. These data therefore suggest that estramustine should be combined to docetaxel in PC patients, but its use could be delayed, particularly in elderly patients, to docetaxel refractory cases. Citation Information: Mol Cancer Ther 2009;8(12 Suppl):A27.

Histological responses during experimental Corynebacterium pseudotuberculosis infection in lambs were investigated in parotid lymph nodes for ten days following inoculation. Lambs were infected by the subcutaneous route into the right eyelid with a virulent strain of C. pseudotuberculosis. Multiple microscopic acute abscesses, predominantly infiltrated with polymorphonuclear (PMN) leucocytes, were seen in the right parotid lymph node on the 1st day post-inoculation (PI). This massive PMN infiltration coincided with a peripheral blood granulocytosis. On day 3 PI, an influx of histiocytes was observed, while the microabscesses became confluent. From day 3 to day 10 PI, these lesions became enlarged and transformed into typical pyogranulomas with a central necrosis and a peripheral mantle of mononuclear cells composed of macrophages, epithelioid cells and lymphocytes; these histological changes were associated with a bacterial dissemination limited to the superficial lymph nodes. A lymphoid hyperplasia with prominent germinal centers was observed in the draining lymph nodes from day 3 PI. These results illustrate the dual role of granulomatous lesions in chronic bacterial infections: although they limit bacterial dissemination, the granulomas do not impair the persistence of infectious organisms in the host, leading to focal tissue damage.

The effect of antigenic stimulation on a bovine lymph node was studied using conventional histological and cytological techniques. The lesions observed in the bovine lymph node following immunological stimulation are similar to those described in other mammalian species. Histometrical studies showed an increase in the size of the nucleus of lymphoid cells in the stimulated lymph nodes. This probably reflects an activation of the lymphoid cell population. The number of the various cell types in the germinal centers appeared to be positively correlated with the stimulation intensity. The complete identification of the different sub-lines of lymphoid cells requires complementary immunocytochemical and electron-microscopic studies.