Lymphoma updates

Histopathological and immunohistochemical characterization of testicular T-cell lymphoma in a dog

Canine lymphoma is the most common neoplasm of the hematopoietic system with the most frequently diagnosed malignancy. Also, dogs affected by T-cell lymphoma displayed a lower rate of complete chemotherapy response and have a high risk of death in the early stage of the disease. A 5-year-old male mixed dog was presented to the Small Animal Hospital, School of Veterinary Medicine, Shiraz University, Shiraz, Iran with a history of left testicle swelling for four months. The testicle had approximately 13.00×10.00 cm size with a greyish-white cut surface. Histopathologically, the testicular tissue was infiltrated by neoplastic cells as only a few degenerated seminiferous tubules have remained. The neoplastic cells were round to oval with pleomorphic nuclei and single or multiple prominent nucleoli. Immunohistochemical analysis revealed positive and negative immunoreactivity for CD3 and CD20, respectively. According to histopathological and immunohistochemical features, the tumor was concluded as a testicular T-cell lymphoma. It seems that recognition of lymphoma type could be helpful for clinicians therapeutic protocols.

Morphological characterization of canine retrobulbar lymphoma

This report characterized seven cases of canine retrobulbar lymphoma that have been diagnosed during 2008 to 2014 by immunophenotyping of CD3 and Pax5. Classification of lymphoma were performed according to the revised WHO guidelines. Four retrobulbar lymphomas were of T-cell origin, while the others were of B-cell. Out of 7 cases, four subtypes were diagnosed in this study; T-cell-rich large B-cell lymphoma (3/7), T-cell lymphoblastic lymphoma (2/7), peripheral T-cell lymphoma (1/7), and cutaneous nonepitheliotropic lymphoma (1/7). T-cell-rich large B-cell lymphoma was found to be the most frequent subtype found.

Phase II study of the oral selective inhibitor of nuclear export (SINE) KPT-335 (verdinexor) in dogs with lymphoma

Background

Chemotherapeutic options for the treatment of canine lymphoma have not changed in several decades necessitating the identification of new therapeutics to improve patient outcome. KPT-335 (verdinexor) is a novel orally bioavailable selective inhibitor of nuclear export (SINE) that exhibited anti-tumor activity against non-Hodgkin lymphoma in a prior phase I study. The objective of this phase II study was to expand upon the initial findings and assess the activity and safety in a larger population of dogs with lymphoma.

Results

Fifty-eight dogs with naïve or progressive B-cell and T-cell lymphoma were enrolled in this clinical trial. KPT-335 was administered orally in one of three dosing groups, based on the previously established biologically active dose of 1.5 mg/kg three times weekly. Treatment with single-agent, orally administered KPT-335 resulted in an objective response rate (ORR) of 37%, of which dogs with T-cell lymphoma had an ORR of 71%. KPT-335 was well tolerated in all dose groups with grade 1–2 anorexia being the most common adverse event. Anorexia was responsive to symptomatic and supportive medications, including prednisone.

Conclusions

These data demonstrate that KPT-335 has biologic activity in canine lymphoma, and support continued evaluation of SINE compounds such as KPT-335 in combination with standard chemotherapeutics in canine lymphoma.

Electronic supplementary material

The online version of this article (10.1186/s12917-018-1587-9) contains supplementary material, which is available to authorized users.

Evaluation of Pax5 expression and comparison with BLA.36 and CD79αcy in feline non-Hodgkin lymphoma

Paired box gene 5 (Pax5) is a widely used B-cell marker for human and canine non-Hodgkin's lymphoma (nHL); however, in the literature there is only one case report using Pax5 in a cat B-cell lymphoma. The purposes of this study were to investigate the expression and detection of B-cell specific activator protein (BSAP) using a monoclonal anti-Pax5 antibody in feline nHL (FnHL) tissue samples to evaluate its diagnostic relevance as a B-cell marker. A total of 45 FnHL samples in 45 cats were evaluated. B-cell lymphoma was the most common immunophenotype (51.1%) for all the samples and T-cell the most common immunophenotype (64.3%) for the gastrointestinal (GI) form. Pax5 stained 82.6% of all B-cell lymphomas and no expression was found in any of the T-cell lymphomas. Anti-Pax5 antibody staining in FnHL is similar to that reported in human and canine counterparts and may offer an excellent B-cell marker in cats.

Stearidonic acid, a plant-based dietary fatty acid, enhances the chemosensitivity of canine lymphoid tumor cells

Lymphoma is the most common hematopoietic tumor in dogs and humans, with similar pathogenesis and therapeutic responses. Anticancer drugs like vincristine (VCR) and doxorubicin (DOX) are often used in treating lymphoma. However, the cure rate is generally poor due to chemoresistance. Here, we sought to determine whether stearidonic acid (SDA), a plant-based dietary fatty acid, sensitizes chemoresistant canine lymphoid-tumor cells. GL-1 B-cell lymphoid-tumor cells were found to be highly sensitive to the antitumor-activity of VCR and DOX, while OSW T-cell and 17-71 B-cell lymphoid-tumor cells were moderately and fully resistant, respectively. SDA, at its non-toxic concentrations, significantly promoted the antitumor action of VCR and DOX in both OSW and 17-71 cells. SDA-mediated chemosensitization was associated with SDA inhibition of P-glycoprotein (P-gp) function. This was confirmed in HEK293 cells stably expressing P-gp as well as by increased binding-affinity of SDA to P-gp in P-gp docking analysis. SDA at its chemosensitizing concentrations did not affect the viability of healthy dog peripheral blood mononuclear cells, suggesting that SDA is non-toxic to normal dog peripheral blood leucocytes at its chemosensitizing concentrations. Our study identifies a novel dietary fatty acid that may be used as a dietary supplement in combination with chemotherapy to promote the antitumor efficacy of the chemotherapy drugs in dogs and possibly in humans with chemoresistant lymphoma.

Malignant lymphoma in african lions (panthera leo)

Malignant lymphoma has become an increasingly recognized problem in African lions (Panthera leo). Eleven African lions (9 male and 2 female) with clinical signs and gross and microscopic lesions of malignant lymphoma were evaluated in this study. All animals were older adults, ranging in age from 14 to 19 years. Immunohistochemically, 10 of the 11 lions had T-cell lymphomas (CD3(+), CD79a(-)), and 1 lion was diagnosed with a B-cell lymphoma (CD3(-), CD79a(+)). The spleen appeared to be the primary site of neoplastic growth in all T-cell lymphomas, with involvement of the liver (6/11) and regional lymph nodes (5/11) also commonly observed. The B-cell lymphoma affected the peripheral lymph nodes, liver, and spleen. According to the current veterinary and human World Health Organization classification of hematopoietic neoplasms, T-cell lymphoma subtypes included peripheral T-cell lymphoma (4/11), precursor (acute) T-cell lymphoblastic lymphoma/leukemia (2/11), chronic T-cell lymphocytic lymphoma/leukemia (3/11), and T-zone lymphoma (1/11). The single B-cell lymphoma subtype was consistent with diffuse large B-cell lymphoma. Feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) testing by immunohistochemistry on sections of malignant lymphoma was negative for all 11 lions. One lion was seropositive for FeLV. In contrast to domestic and exotic cats, in which B-cell lymphomas are more common than T-cell lymphomas, African lions in this study had malignant lymphomas that were primarily of T-cell origin. Neither FeLV nor FIV, important causes of malignant lymphoma in domestic cats, seems to be significant in the pathogenesis of malignant lymphoma in African lions.

Fast molecular diagnostics of canine T-cell lymphoma by PCR and capillary gel electrophoresis with laser-induced fluorescence detector

Lymphoma is the most common hematopoietic tumor in dogs and manifests as a proliferation of malignant lymphoid cells primarily affecting the lymph nodes or solid visceral organs. We describe the use of capillary gel electrophoresis (CGE) with a laser-induced fluorescence (LIF) detector based on polymerase chain reaction (PCR) to rapidly detect a disorder of the canine T-cell receptor gamma (TCRgamma) gene. After the PCR amplification of the specific TCR( gene in dogs, the 90-bp DNA fragment amplified was separated in a fused-silica capillary by CGE-LIF. Under an electric field of 375 V/cm and with a sieving matrix of 1.5% poly (ethyleneoxide) (M(r) 600,000), the amplified PCR products were analyzed within 4 min by CGE separation. When the CGE-LIF method was applied to real clinical samples of the specific DNA fragment of the TCR( gene, the migration time and the corrected peak area showed relative standard deviations (n=5) of 0.29% and 0.58%, respectively. Both methods of CGE-LIF and slab gel electrophoresis showed same results for nine clinical samples. This PCR/CGE-LIF technique may prove to be a new fast and simple tool for the rapid diagnosis of the PCR-amplified DNA of canine T-cell lymphoma.

The canine genome

The dog has emerged as a premier species for the study of morphology, behavior, and disease. The recent availability of a high-quality draft sequence lifts the dog system to a new threshold. We provide a primer to use the dog genome by first focusing on its evolutionary history. We overview the relationship of dogs to wild canids and discuss their origin and domestication. Dogs clearly originated from a substantial number of gray wolves and dog breeds define distinct genetic units that can be divided into at least four hierarchical groupings. We review evidence showing that dogs have high levels of linkage disequilibrium. Consequently, given that dog breeds express specific phenotypic traits and vary in behavior and the incidence of genetic disease, genomic-wide scans for linkage disequilibrium may allow the discovery of genes influencing breed-specific characteristics. Finally, we review studies that have utilized the dog to understand the genetic underpinning of several traits, and we summarize genomic resources that can be used to advance such studies. We suggest that given these resources and the unique characteristics of breeds, that the dog is a uniquely valuable resource for studying the genetic basis of complex traits.