Prognostic value of CD44 variant isoform expression in dogs with multicentric high-grade B-cell lymphoma.

OBJECTIVE To determine the prognostic value of CD44 variant isoform expression in dogs with multicentric high-grade B-cell lymphoma (BCL). ANIMALS 45 dogs with multicentric BCL and 10 healthy control Beagles. PROCEDURES The medical record database of a veterinary teaching hospital was searched to identify dogs with BCL that were treated between November 2005 and April 2015. Information regarding overall response to chemotherapy, progression-free survival (PFS) time, and overall survival time was extracted from each record. Archived lymph node aspirate specimens from dogs with BCL and lymph node aspirate specimens from the 10 control dogs underwent real-time PCR analysis to determine mRNA expression of CD44 variant isoforms of exons 3, 6, and 7 and the CD44 whole isoform. For each isoform, mRNA expression was compared between dogs with BCL and control dogs. The mean relative expression of each isoform was used to classify dogs with BCL into either a high- or low-expression group, and overall response rate, PFS time, and overall survival time (ie, indices of prognosis) were compared between the 2 groups. RESULTS For all isoforms evaluated, mean relative mRNA expression for dogs with BCL was numerically lower than that for control dogs. Dogs with BCL and high CD44 isoform expression had a lower overall response rate, median PFS time, and median overall survival time, compared with dogs with BCL and low CD44 isoform expression. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that, for dogs with BCL, high expression of exons 3, 6, and 7 was associated with a poor prognosis.

Intranuclear inclusions in a dog with B-cell leukemia.

A 7-year-old Shetland Sheepdog was presented with anorexia. A CBC indicated thrombocytopenia and neutropenia. Bone marrow cytology revealed that 67.7% of all nucleated cells (ANC) were anaplastic large mononuclear cells. These cells were confirmed to be of B-cell origin based on IgH rearrangement, immunohistochemical, and flow cytometric analysis. Microscopic examination revealed that the neoplastic cells had intranuclear inclusions resembling Dutcher bodies. Immunohistochemistry confirmed that the intranuclear inclusions were immunopositive for IgG antibodies. The periodic acid-Schiff reaction was negative for the presence of polysaccharides and related substances. Although the dog achieved complete remission with a multi-drug chemotherapy protocol, it ultimately died because of tumor progression and acute renal insufficiency on day 201. This is the first known case of canine acute B-cell leukemia with intranuclear inclusions resembling Dutcher bodies.

Minimal residual disease in canine lymphoma: An objective marker to assess tumour cell burden in remission.

Lymphoma is the most common haematopoietic malignancy in dogs. Since a high proportion of dogs with lymphoma achieve remission soon after initiation of chemotherapy, an objective marker assessing treatment efficacy is required. Following clinical remission, the residual population of tumour cells can be referred to as the minimal residual disease (MRD). MRD traditionally has been detected by cytology and flow cytometry; however, if the burden of malignant cells is low, these methods might not be sufficiently sensitive to detect MRD. As an extension of the development of PCR for antigen receptor gene rearrangements (PARR) in dogs, there has been recent progress in the application of real-time quantitative PCR (RT-qPCR) to canine lymphoma. With the RT-qPCR system, a very high sensitivity (1 cell per 10,000 cells) has been achieved by preparing allele-specific oligonucleotide primers and probes designed from neoplastic clones of each dog. A series of MRD diagnostics studies employing the RT-qPCR system has revealed its usefulness as a prognostic indicator, an objective marker of treatment efficacy and a predictor of relapse for dogs with lymphoma receiving chemotherapy. Introduction of the MRD monitoring system will provide an innovative scientific tool in the development of superior treatments and monitoring strategies for canine lymphoma.

Detection of circulating tumor cells using GeneScan analysis for antigen receptor gene rearrangements in canine lymphoma patients.

The presence of circulating tumor cells (CTCs) serves as a prognostic marker and indicator of disease relapse, as well as a means of evaluating treatment efficacy in human and canine lymphoma patients. As an extension of our previous study for the construction of clinically useful GeneScan system, we utilized the GeneScan system for detecting CTCs in canine lymphoma patients. Samples from the primary lesion and peripheral blood mononuclear cells (PBMCs) were obtained from 32 dogs with lymphoma at initial diagnosis. All samples were subjected to polymerase chain reaction (PCR) for antigen receptor gene rearrangements (PARR) followed by GeneScan analysis. Common clonal rearrangements with identical amplified fragments were detected in both the primary lesion and PBMCs in 19 of the 32 dogs (59.4%). However, the detection rate of CTCs varied among the anatomical classification of lymphoma studied. GeneScan analysis following PARR would facilitate studies on determining the clinical significance of CTCs in canine lymphoma patients.

Construction of a multicolor GeneScan analytical system to detect clonal rearrangements of immunoglobulin and T cell receptor genes in canine lymphoid tumors.

Polymerase chain reaction (PCR) amplification to detect immunoglobulin heavy chain (IgH) and T cell receptor γ-chain (TCRγ) gene rearrangements has recently become widely used as part of the diagnostic strategy for lymphoid tumors in dogs. In this study, we constructed a multicolor GeneScan analytical system to improve the sensitivity and resolution of the clonality analysis of antigen receptor gene rearrangements in dogs. We used 7 reactions per sample, with 2 PCR conditions, to amplify IgH/TCRγ and control genes. By using multicolor-labeled primers, these 7 PCR products could be combined into 3 tubes before capillary electrophoresis. Clonal rearrangement of the IgH/TCRγ genes was detected in 93.3% of dogs with multicentric lymphoma and 84.6% of dogs with gastrointestinal lymphoma. Detection sensitivity of the clonally expanded cells in the background of normal peripheral blood mononuclear cells was 1-10%. The multicolor GeneScan analytical system developed here may prove to be helpful for the diagnosis of lymphoid tumors in dogs.

Evaluation of the drug sensitivity and expression of 16 drug resistance-related genes in canine histiocytic sarcoma cell lines.

Canine histiocytic sarcoma (HS) is an aggressive tumor type originating from histiocytic cell lineages. This disease is characterized by poor response to chemotherapy and short survival time. Therefore, it is of critical importance to identify and develop effective antitumor drugs against HS. The objectives of this study were to examine the drug sensitivities of 10 antitumor drugs. Using a real-time RT-PCR system, the mRNA expression levels of 16 genes related to drug resistance in 4 canine HS cell lines established from dogs with disseminated HS were determined and compared to 2 canine lymphoma cell lines (B-cell and T-cell). These 4 canine HS cell lines showed sensitivities toward microtubule inhibitors (vincristine, vinblastine and paclitaxel), comparable to those in the canine B-cell lymphoma cell line. Moreover, it was shown that P-gp in the HS cell lines used in this study did not have enough function to efflux its substrate. Sensitivities to melphalan, nimustine, methotrexate, cytarabine, doxorubicin and etoposide were lower in the 4 HS cell lines than in the 2 canine lymphoma cell lines. The data obtained in this study using cultured cell lines could prove helpful in the developing of advanced and effective chemotherapies for treating dogs that are suffering from HS.

Hypermethylation of the death-associated protein kinase CpG island in canine B-cell lymphoid tumors.

Death-associated protein kinase (DAPK) is a 160-kD serine/threonine kinase known as a key molecule in interferon-γ (IFN-γ)-induced apoptosis and tumor suppression. Hypermethylation of the CpG island in DAPK inactivates the gene in a variety of human malignancies. This study aimed to detect the inactivation of DAPK in canine lymphoid tumor cells. The sequence of canine DAPK cDNA was obtained from normal dog peripheral blood mononuclear cells after reverse transcription polymerase chain reaction (RT-PCR). By rapid amplification of 5'-cDNA ends, the transcription initiation site of the DAPK gene was identified. The CpG island located upstream of the translation initiation site was identified by using a search algorithm. The methylation status of the CpG island was examined using bisulfite sequence analysis and methylation-specific PCR (MSP). The inactivation of DAPK gene was examined in 3 canine lymphoid tumor cell lines, GL-1 (B-cell leukemia), CLBL-1 (B-cell lymphoma), and CL-1 (T-cell lymphoma). DAPK mRNA expression was measured by real-time RT-PCR. IFN-γ-induced apoptosis was detected by terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) assay. The influence of demethylation was examined with 5-aza-2'-deoxycytidine (5-aza-dC). The methylation status in 14 dogs with various lymphoid tumors was screened by MSP. A 1926-bp CpG island containing 280 CpG repeats was identified upstream of the translation start site of canine DAPK. Bisulfate sequence analysis and MSP revealed hypermethylation of the CpG island in GL-1 cells, but not in CLBL-1 or CL-1 cells. The amount of DAPK mRNA was significantly smaller in GL-1 cells than CLBL-1 and CL-1 cells. IFN-γ-induced apoptosis was detected in CLBL-1 and CL-1 cells but not in GL-1 cells. Treatment with 5-aza-dC significantly increased the amount of DAPK mRNA and IFN-γ-induced apoptosis in GL-1 cells. These results revealed the inactivation of DAPK through methylation of its CpG island in GL-1 cells. MSP showed hypermethylation of the DAPK CpG island in 5 of 8 primary B-cell lymphoma samples, but not in any of the 6 primary T-cell lymphoid tumor samples obtained from canine patients. DAPK was inactivated through hypermethylation of its CpG island in canine B-cell lymphoid tumor cells. This study will lead to the use of canine B-cell lymphoid tumors as an animal model to evaluate the efficacy of demethylating agents.

Evaluation of DNA methylation profiles of the CpG island of the ABCB1 gene in dogs with lymphoma.

OBJECTIVE: To examine the DNA methylation status of the ABCB1 gene in tumor cells of dogs with lymphoma. ANIMALS: 27 dogs with multicentric B-cell high-grade lymphoma (19 chemotherapy-sensitive dogs and 8 chemotherapy-resistant dogs). PROCEDURES: The DNA methylation profile of the CpG island of the ABCB1 gene was analyzed by use of bisulphite sequencing and real-time methylation-specific PCR assay in lymphoma cells. Quantitative reverse transcriptase PCR assay of the ABCB1 gene was conducted to measure the amount of mRNA. Correlation between the amount of ABCB1 mRNA and the methylation rate was examined. RESULTS: The CpG island of the ABCB1 gene was hypomethylated in most dogs in both the chemotherapy-sensitive and -resistant groups. No significant difference was detected in the methylation rate between the 2 groups, and no significant correlation was detected between the methylation rate and the mRNA expression level. CONCLUSIONS AND CLINICAL RELEVANCE: Expression of the ABCB1 gene was not suppressed by hypermethylation of its CpG island in most dogs with lymphoma regardless of their chemotherapy sensitivity status.

Antitumour effect and modulation of expression of the ABCB1 gene by perifosine in canine lymphoid tumour cell lines.

Acquisition of multidrug resistance (MDR) is a common cause of treatment failure during chemotherapy for dogs with lymphoma (lymphosarcoma). Overexpression of P-glycoprotein (P-gp), encoded by the ABCB1 gene, is associated with MDR. Perifosine, an Akt inhibitor, downregulates the expression of P-gp. In this study, the antitumour effect of perifosine and its ability to modulate ABCB1 expression were examined in four canine lymphoid tumour cell lines (GL-1, CLBL-1, UL-1 and Ema). GL-1 and CLBL-1 were inherently negative for P-gp, while UL-1 and Ema were inherently positive for P-gp. GL-1 and UL-1 were sensitive to perifosine, whereas CLBL-1 and Ema were resistant. The amount of ABCB1 mRNA significantly decreased after treatment with perifosine in UL-1, associated with activation of the c-Jun NH2-terminal kinase (JNK) pathway, but such an effect was not observed in Ema. In UL-1, perifosine decreased the efflux of rhodamine 123 dye and reduced the 50% inhibitory concentration of vincristine, but such effects were not observed in Ema. Perifosine had an antitumour effect in 2/4 canine lymphoid tumour cell lines. In 1/4 cell lines, perifosine downregulated ABCB1 gene expression through activation of the JNK pathway and increased sensitivity to vincristine.

Intestinal protease-activated receptor-2 and fecal serine protease activity are increased in canine inflammatory bowel disease and may contribute to intestinal cytokine expression.

Serine proteases elicit cellular responses via protease-activated receptor-2 (PAR-2) which is known to regulate inflammation and the immune response. Although the gastrointestinal tract is exposed to large amounts of proteolytic enzymes, the role of PAR-2 in canine inflammatory bowel disease (IBD) remains unclear. The objective of this study was to investigate the effects of PAR-2 activation on inflammatory cytokine/chemokine gene expression in canine intestine and the expression of intestinal PAR-2 and fecal serine protease activity in dogs with IBD. Duodenal biopsies from healthy dogs were cultured and treated ex vivo with trypsin or PAR-2 agonist peptide, and inflammatory cytokine/chemokine gene expression in the tissues was then quantified by real-time PCR. PAR-2 mRNA and protein expression levels in the duodenal mucosa were examined by real-time PCR and immunohistochemistry, respectively. Fecal serine protease activity was determined by azocasein assay. In ex vivo-cultured duodenum, trypsin and PAR-2 agonist peptide induced significant up-regulation of mRNA expression levels of interleukin-1 ß (IL-1ß), IL-8, mucosae-associated epithelial chemokine (MEC) and fractalkine, and this up-regulation was inhibited by a serine protease inhibitor. Duodenal PAR-2 mRNA and protein expression levels were higher in dogs with IBD than in healthy control dogs. Fecal serine protease activity was significantly elevated in dogs with IBD, and the level of activity correlated positively with the clinical severity score. These results suggest that PAR-2 may contribute to the pathogenesis of canine IBD by inducing expression of inflammatory mediators in response to luminal serine proteases.

Inhibition of p16 tumor suppressor gene expression via promoter hypermethylation in canine lymphoid tumor cells.

To investigate the epigenetic regulation of the p16 gene in canine lymphoid tumor cells, its methylation status was examined in four canine lymphoid tumor cell lines. In three canine lymphoid tumor cell lines (CLBL-1, GL-1, and UL-1) with low-level p16 mRNA expression, 20 CpG sites in the promoter region of p16 gene were consistently methylated although all of the CpG sites were not methylated in another cell line (CL-1) and normal lymph node cells. The expression level of p16 mRNA in these three cell lines was restored after cultivation in the presence of a methylation inhibitor, 5-Aza-2'-deoxycitidine, indicating inactivation of p16 gene via hypermethylation. This study revealed the inactivation of p16 gene through hypermethylation of its CpG island in a fraction of canine lymphoid tumor cells.

Methylation of TNFRSF13B and TNFRSF13C in duodenal mucosa in canine inflammatory bowel disease and its association with decreased mucosal IgA expression.

Although decreased intestinal IgA expression has been reported in dogs with inflammatory bowel disease (IBD), the mechanism underlying this decrease is unknown. Transmembrane activator and calcium-modulating cyclophilin-ligand interactor (TACI) and B cell-activating factor of the TNF family (BAFF) receptor (BAFF-R) are key receptors for T cell-independent IgA class switching by the binding of IgA-inducing cytokine a proliferation-inducing ligand (APRIL) and BAFF. Here we show decreased TACI and BAFF-R mRNA expression and hypermethylation of their corresponding genes TNFRSF13B and TNFRSF13C, respectively in the duodenal mucosa of dogs with IBD. To examine whether DNA methylation of the TNFRSF13B and TNFRSF13C influences the mRNA expression of TACI and BAFF-R, respectively, we first analyzed methylation and mRNA expression levels in vitro using 2 canine B lymphoid cell lines, GL-1 and CLBL-1. Methylation profiles in the cells were examined by bisulfite sequencing and methylation-specific PCR (MSP) with primer pairs specific to methylated or unmethylated sequences. These methylation analyses revealed hypermethylation of the CpG islands of both TNFRSF13B and TNFRSF13C in GL-1, but not in CLBL-1 cells. The mRNA expression levels of TACI and BAFF-R were significantly lower in GL-1 than in CLBL-1 cells. Treatment with 5-aza-2'-deoxycytidine significantly increased TACI and BAFF-R mRNA expression in GL-1 cells through demethylation of TNFRSF13B and TNFRSF13C, respectively. These results suggest that the mRNA expression of TACI and BAFF-R is regulated through methylation of their genes in canine B cells. Quantitative real-time MSP showed significant hypermethylation of the CpG islands of TNFRSF13B and TNFRSF13C in the duodenal mucosa of dogs with IBD. Furthermore, duodenal mRNA expression levels of TACI and BAFF-R were significantly lower in dogs with IBD than in healthy controls. The mRNA expression levels of TACI positively correlated with intestinal IgA expression, whereas the methylation level of its gene (TNFRSF13B) negatively correlated with IgA expression. The present results suggest the role of TACI in the regulation of mucosal IgA expression through epigenetic modifications.

Differential expression of CD45 isoforms in canine leukocytes.

CD45 is one of the most abundant molecules expressed on the white blood cell surface in various mammals. In this study, we investigated the differential expression of CD45 isoforms in normal canine white blood cells. It has been shown that all canine nucleated blood cells express CD45. We characterized two major isoforms of canine CD45 derived from alternative splicing: a higher molecular weight isoform, CD45RA, and a lower molecular weight isoform, CD45RO. The nucleotide sequences of the two isoforms were identical, except for the region corresponding to a part in the extracellular domain. Flow cytometry analysis using an antibody that recognizes CD45RA, but not CD45RO, revealed that granulocytes did not express CD45RA, and monocytes express low levels of CD45RA. We further analyzed the expression levels of CD45RA in each lymphocyte subpopulation and found that the expression of CD45RA on CD21+ B cells was uniform. On the other hand, expression of CD45RA on CD3+ T cells was variable. Upon stimulation of lymphocytes with Con A, the CD45RA+ fraction increased, indicating that not only the phenotypes but also the activation status influences the isoform expression pattern of CD45. Our finding provides a basic knowledge of the expression of canine CD45, which could be a tool to study lymphocytes with various phenotypes, developmental stages, and activation status.

Prognostic analyses on anatomical and morphological classification of feline lymphoma.

The present study was carried out to analyze the prognosis of 163 cats with lymphoma classified anatomically and cytomorphologically. Anatomically, alimentary lymphoma was the most common form and showed significantly shorter survival than mediastinal and nasal lymphomas in cats. Cytomorphologically, there was no predominant subtype in feline lymphomas. Immunoblastic type (18%), centroblastic type (16%), globule leukocyte type (15%), lymphocytic type (12%), lymphoblastic type (12%), pleomorphic medium and large cell type (10%) and anaplastic large cell type (7%) were relatively common subtypes. Most of the cats with globule leukocyte lymphoma had the alimentary form. Comparing median survival time among classifications, cats with globule leukocyte lymphoma showed significantly shorter survival than those with high-grade and other low-grade lymphomas. Furthermore, cats with high-grade lymphomas showed significantly shorter survival than cats with other low-grade lymphomas. The present study indicated the clinical significance of anatomical and cytomorphological evaluation in feline lymphomas.

Phase I dose-escalation study of nimustine in tumor-bearing dogs.

Nimustine (ACNU) is an alkylating agent of the nitrosourea and can be an antineoplastic agent in dogs. But, there has been no report on its dose-limiting toxicity (DLT) in dogs. This study was a phase I dose-escalation clinical trial to determine the maximum tolerated dose (MTD) and DLT of ACNU in tumor-bearing dogs. The starting dosage was 25 mg/m(2), and subsequent dosages were administered in increments of 5 mg/m(2) in cohort of 3 dogs. Eight dogs were included, the MTD was determined to be 25 mg/m(2), DLT was neutropenia, and the optimal interval was considered to be 21 days. The data herein provide a basis for the subsequent phase II trial of ACNU in dogs.

Clinical characteristics and prognostic factors in dogs with histiocytic sarcomas in Japan.

Canine histiocytic sarcoma (HS) is a rare neoplasm that originates from dendritic cells or macrophages, and there have been a number of cases experienced in Japan. To identify the characteristics and prognostic variables that determine outcome in dogs with HS in Japan, medical records of 73 dogs with HS were retrospectively analyzed. Signalment, clinical signs, complete blood count (CBC), blood chemistry profiles, treatment, response to treatment and overall survival (OS) were analyzed. Diagnosis of HS was determined histologically in 44 cases and cytologically in 29 cases. The most frequently diagnosed breeds were Flat-Coated Retrievers (n=16, odds ratio [OR] 62.0), Pembroke Welsh corgis (n=15, OR 9.7) and Bernese Mountain dogs (n=14, OR 45.0). Median survival time for all dogs in this study was 43 days. In the dogs that received no treatment or only symptomatic treatment, the median OS was 12 days (range 2-254 days) compared with that of dogs that received surgical treatment and/or chemotherapy (85 days, range 4-360 days). Univariate analysis identified anemia, thrombocytopenia, hypoalbuminemia, hypoproteinemia and not receiving antitumor treatment (chemotherapy and/or surgery) as factors significantly associated with shorter OS. Multivariate analysis confirmed that platelet counts, localized/disseminated lesional pattern and whether the dog received antitumor treatment were significantly predictive of survival.

Chronic myelogenous leukaemia with persistent neutrophilia, eosinophilia and basophilia in a cat.

Chronic myelogenous leukaemia was diagnosed in a 7-year-old male neutered domestic shorthair cat. Leukocytosis (74,900/µl)--mature neutrophilia, eosinophilia and basophilia--was observed. Bone marrow aspiration revealed hypercellularity with proliferation of cells of myeloid lineage. An underlying condition leading to leukocytosis was not identified. The severe leukocytosis did not respond to antibiotic therapy. Based on these findings, chronic myelogenous leukaemia was diagnosed. Because of the absence of clinical signs, the cat was monitored without treatment until 7 months after diagnosis, when it developed pruritic skin lesions. Pruritus was controlled with oral prednisolone. Forty-two months after diagnosis, the cat developed nasal lymphoma, which was treated with radiation therapy, resulting in complete remission. The cat was still in good physical condition 63 months after diagnosis, despite the persistence of marked neutrophilia, eosinophilia and basophilia.

The regulation of the expression of ABCG2 gene through mitogen-activated protein kinase pathways in canine lymphoid tumor cell lines.

Treatments for canine lymphoma often fail, because tumor cells acquire multidrug resistance (MDR). MDR can develop through several mechanisms, among which the overexpression of drug transporters in tumor cells is a well-studied mechanism. ATP-binding cassette sub-family G member 2 (ABCG2) belongs to the ABC-transporters, that are representative drug efflux pumps associated with MDR in human tumor cells. However, the regulation of ABCG2 gene expression in canine tumors is not well understood. The purpose of the present study was to reveal the regulatory mechanism of ABCG2 gene expression in 4 canine lymphoid tumor cell lines, GL-1, CLBL-1, UL-1 and Ema. Treatment with phorbol 12-myristate 13-acetate (PMA), the protein kinase C (PKC) activator, stimulated MAPK/ERK pathway in GL-1, UL-1 and Ema cells and JNK pathway in UL-1 and Ema cells. When GL-1 and UL-1 cells were treated with PMA and the MAPK/ERK kinase inhibitor U0126, ABCG2 gene expression levels were elevated above those in untreated cells. Similarly, ABCG2 gene expression increased above control levels in UL-1 and Ema cells treated with PMA and the JNK inhibitor SP600125. However, ABCG2 gene expression was unaffected by U0126 exposure in CLBL-1 cells, in which activation of MAPK/ERK pathway was observed in non-treated cells. These results suggested that MAPK/ERK and JNK pathways downregulate ABCG2 gene expression, which is upregulated by unidentified but possibly PKC-dependent pathways, in several types of canine lymphoid tumor cells.

Epigenetic regulation of the ABCB1 gene in drug-sensitive and drug-resistant lymphoid tumour cell lines obtained from canine patients.

Multidrug resistance (MDR) is a major obstacle in the treatment of cancer. Overexpression of P-glycoprotein (P-gp), encoded by the ABCB1 (MDR1) gene, is an important factor in determining the MDR phenotype of a tumour. Although recent studies have revealed the epigenetic transcriptional regulation of the human ABCB1 gene, such regulation of this gene has not been examined in dogs. The aim of the current study was to evaluate differences in epigenetic regulation of the ABCB1 gene, between drug-sensitive and drug-resistant canine lymphoid tumour cell lines. In two drug-sensitive cell lines, GL-1 and CLBL-1, ABCB1 mRNA expression was significantly lower than in two drug-resistant cell lines, UL-1 and Ema, using real-time quantitative polymerase chain reaction (QPCR). Bisulphite sequencing and real-time methylation-specific PCR revealed that the CpG island present in the upstream region of exon 2 was hypermethylated in GL-1 and CLBL-1, but hypomethylated in UL-1 and Ema. Chromatin immunoprecipitation and QPCR revealed that histone H3 acetylation in the same CpG island was significantly increased in UL-1 and Ema compared to GL-1 and CLBL-1. Treatment with 5-aza 2'-deoxycytidine or trichostatin A increased ABCB1 mRNA expression in GL-1 and CLBL-1. DNA methylation and histone H3 acetylation were shown to be involved in ABCB1 gene expression and associated with an MDR phenotype in these canine lymphoid tumour cell lines.

Plasma transferrin concentration as a nutritional marker in malnourished dogs with nutritional treatment.

Rapid turnover proteins, such as transferrin (Tf), are used as dynamic nutritional assessment proteins in human medicine. However, nutritional status in veterinary medicine is mostly assessed on the basis of classical static factors, such as body weight, body condition score and plasma albumin level. This study evaluated the clinical usefulness of Tf as a nutritional assessment marker by measuring plasma Tf concentrations in malnourished dogs before and after nutritional treatment. Posttreatment plasma Tf concentrations were significantly higher than the pretreatment concentrations, although the albumin concentration did not change significantly. The numbers of dogs that exhibited increases in plasma Tf concentrations were significantly related to weight gain. Furthermore, the survival rates at day 60 after treatment initiation were significantly higher in dogs with plasma Tf concentrations above the reference value (180 mg/dl) after the nutritional treatment than in those with a plasma Tf concentration<180 mg/dl. In conclusion, the plasma Tf concentration is related to nutritional condition and would be a candidate for a novel nutritional assessment marker in dogs.