Comparative oncology is a developing research discipline that is being used to assist our understanding of human neoplastic diseases. Companion canines are a preferred animal oncology model due to spontaneous tumor development and similarity to human disease at the pathophysiological level. We use a paired RNA sequencing (RNA-Seq)/microarray analysis of a set of four normal canine lymph nodes and ten canine lymphoma fine needle aspirates to identify technical biases and variation between the technologies and convergence on biological disease pathways. Surrogate Variable Analysis (SVA) provides a formal multivariate analysis of the combined RNA-Seq/microarray data set. Applying SVA to the data allows us to decompose variation into contributions associated with transcript abundance, differences between the technology, and latent variation within each technology. A substantial and highly statistically significant component of the variation reflects transcript abundance, and RNA-Seq appeared more sensitive for detection of transcripts expressed at low levels. Latent random variation among RNA-Seq samples is also distinct in character from that impacting microarray samples. In particular, we observed variation between RNA-Seq samples that reflects transcript GC content. Platform-independent variable decomposition without a priori knowledge of the sources of variation using SVA represents a generalizable method for accomplishing cross-platform data analysis. We identified genes differentially expressed between normal lymph nodes of disease free dogs and a subset of the diseased dogs diagnosed with B-cell lymphoma using each technology. There is statistically significant overlap between the RNA-Seq and microarray sets of differentially expressed genes. Analysis of overlapping genes in the context of biological systems suggests elevated expression and activity of PI3K signaling in B-cell lymphoma biopsies compared with normal biopsies, consistent with literature describing successful use of drugs targeting this pathway in lymphomas.

The env and gag genes from feline leukaemia virus were expressed in a thymidine kinase-negative feline herpesvirus and a baculovirus. Cats were vaccinated with various combinations of these recombinant viruses and 100% protection against feline leukaemia virus challenge was achieved using an immunization schedule which utilized both env and gag products delivered at both a mucosal and systemic site.

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PF-04691503 is a dual inhibitor of both PI3K and mTOR, inhibits PI3K signaling in cancer cell lines, and exhibits in vitro and in vivo anti-proliferative activity in PI3K-pathway driven cell lines. It is a nanomolar inhibitor of all 4 isoforms of the catalytic subunit of PI3K and of both TORC1 and TORC2. Anti-cancer activity of the inhibitor is hypothesized to be through inhibition of survival, proliferative, and anti-apoptotic processes. Phosphorylation of the protein kinase, Akt, is associated with activation of the phosphatidyl 3-kinase (PI-3K)/mammalian target of rapamycin (mTOR) signaling pathway, which plays a role in cell proliferation (Witzig and Kaufmann 2006). Recent studies by Gulmann et al (2005) showed increased pAKT in human lymphoma samples, and those of Rassidakis et al (2005) suggested that inhibition of Akt phosphorylation (pAKT) may be of value in the treatment of lymphoma. Using flow cytometry we report that cells obtained from 10 of 11 lymph node biopsies of dogs with lymphoma exhibit detectable pAKT using a phospho-Akt (Ser473) antibody, compared to an IgG isotype control or a competative phospho-Akt (Ser473) blocking peptide. Cells from normal canine lymph nodes do not exhibit detectable pAKT. The majority of the pAKT signal was generated from lymphoblasts present in the malignant, but not in the normal, lymph nodes. In separate studies, lymph node cells obtained from healthy dogs and dogs with lymphoma were stimulated in vitro with the mitogen, Con A. The novel PI3K/mTOR dual inhibitor, PF-04691503, produced dose dependent inhibition of proliferation as exemplified in a dog with T-cell lymphoma (EC50 = 18 nM)) and in a normal dog (EC50 = 53 nM)). No pAKT signal could be detected in peripheral blood mononuclear cells, from normal or lymphoma patients stimulated with hu-IGF-1 (the endogenous ligand for PI3), Con-A or LPS. These data suggest that PI-3 kinase and pAKT (1) are activated in canine lymphoma, (2) play a role in the lymphoproliferation associated with this disease, (3) represent legitimate targets for therapeutic intervention in lymphoma, and (4) can be studied ‘translationally’ in dogs as a model for humans. Gulmann C, Espina V, Petricoin E, et al. Proteomic analysis of apoptotic pathways reveals prognostic factors in follicular lymphoma. Clin Cancer Res 11:5847-5855, 2005. Rassidakis GZ, Feretzaki M, Atwell C, et al. Inhibition of Akt increases p27 Kip1 levels and induces cell cycle arrest in anaplastic large cell lymphoma. Blood 105:827-829, 2005. Witzig TE and Kaufmann SH. Inhibition of phosphatidyl 3-kinase (PI-3K)/mammalian target of rapamycin (mTOR) pathway in hematologic malignancies. Current Treatment Options in Oncology 7:285-294, 2006. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5043.