Distribución de ß-galactosidasa por transferencia adenoviral como modelo de terapia génica intralinfonodal en perros con linfosarcoma multicéntrico espontáneo / Distribution of ß-galactosidase by adenoviral transfer as a model for intralymphonodal gene therapy in dogs with spontaneous multicentric lymphosarcoma

La terapia génica en cáncer se administra principalmente por vía intravenosa e in situ mediante el empleo de vectores virales y no virales. La administración sistémica del vector transfiere el gen terapéutico al tejido neoplásico, pero también a otros órganos. El objetivo de este estudio fue evaluar la distribución de expresión del gen reportero Lac Z insertado en un vector adenoviral y administrado vía intralinfonodal (ILN) en perros con linfosarcoma multicéntrico espontáneo. La distribución de la expresión de la proteína ßgalactosidasa de un adenovirus no replicativo recombinante (Adßgal) fue evaluada 72 h después de su administración ILN en 6 perros con linfosarcoma multicéntrico espontáneo mediante la exposición al sustrato cromogénico X-gal. Se emplearon dosis de 0 (control), 1,35 X 10 a la 10, 2,53 X 10 a la 10, 6,10 X 10 a la 10, 18,38 X 10 a la 10, y 153,85 X 10 a la 10 partículas virales (PV)/kg. La expresión se presentó en un 100 por ciento del tejido linfocítico neoplásico que incluye, linfonodos y bazo, con menor intensidad se expresó en órganos infiltrados con linfocitos neoplásicos: hígado, médula ósea y pulmones. La expresión de ßgal fue exclusiva en tejido linfocítico neoplásico y en sitios de metástasis.Esto permite mejorar la eficiencia en la transferencia del gen terapéutico con menores dosis y reducir los riesgos detoxicidad y también potencialmente menos inmunogénico. La terapia génica adenoviral vía intralinfonodal tiene un elevado potencial para su aplicación en animales y humanos con linfosarcoma y también para metástasis linfonodales.

Gene therapy administration in cancer is mainly performed by intravenous, oral, and in situ routes, with viral or nonviral delivery vector systems. Systemic administration frequently transfers the therapeutic gene to neoplastic tissue and as well as to other organs. The objective of this study was to evaluate the distribution expression of Lac Z reporter gene by adenoviral transfer administered by intralymphonodal route (ILNR) in dogs with lymphosarcoma. The distribution of b-galactosidase protein expression by a non replicative recombinant adenovirus (Adb-gal) delivery was determined in six dogs with spontaneous multicentric lymphosarcoma, 72 h after ILNR administration using X-gal chromogenic substrate. The doses administered were 0 (control), 1.35 X 1010, 2.53 X 1010, 6.10 X 1010, 18.38 X 1010 and 153.85 X 1010 viral particles (VP) /kg. The expression was manifested in 100% of lymphocytic tissue, including lymph nodes and spleen. The infiltrated organs with neoplastic lymphocytes: liver, bone marrow and lungs were positive but with lower intensity. Conclusion. The expression of b-gal was restricted to neoplastic lymphocytic tissue and metastatic sites. The ILNR would enhance gene therapy efficacy to a specific cell type and permit the delivery of lower doses, which result in reduced toxicity and may also potentially be less immunogenic. This suggests that adenoviral gene therapy by ILNR is a potential model of administration in animals and human beings with lymphosarcoma and also for metastasis to lymph nodes.

Hepatosplenic large cell immunoblastic lymphoma in a bottlenose dolphin (Tursiops truncatus) with high levels of polychlorinated biphenyl congeners.

This report describes a large cell immunoblastic lymphoma in a bottlenose dolphin found stranded alive in Gran Canaria, Spain. Diffuse infiltration of round neoplastic cells was observed in the splenic cords and sinuses and in hepatic sinusoids, resulting in moderate organ enlargement. The tumour cells (immunophenotype IgG+ and CD3-) showed scant, lightly eosinophilic or basophilic cytoplasm, distinct cell boundaries and hyperchromatic nuclei, each with one or more nucleoli. Mitoses were common. On the basis of histopathological, immunohistochemical and ultrastructural features, the tumour was classified as an immunoblastic lymphoma. Eleven polychlorinated biphenyl (PCB) congeners, 23 organochlorine pesticides and 16 polycyclic aromatic hydrocarbons (PAHs) were detected in the blubber and liver. High concentrations of PCBs 153, 180, 138 and 187 found in the liver may have been associated with the hepatosplenic lymphoma.

B-cell immunoblastic lymphoma with multinucleated giant cells in a cat.

A 10-year-old male mixed breed cat died after six months history of intermittent vomiting and weight loss. At necropsy, large white-colored foci were found in both kidneys, and whitish thickening of the gastric wall was present at the pyloric part of the stomach. Histopathological examination revealed that both lesions consisted of proliferation of large-sized neoplastic lymphocytes intermingled with multinucleated giant cells. Immunohistochemically, the neoplastic cells were positive for both B-cell antigen receptor complex (CD 79 alpha cy) and MHC class II, although multinucleated giant cells were negative. The present case was diagnosed as B-cell immunoblastic lymphoma with multinucleated giant cells.

Severe pruritus associated with lymphoma in a dog.

A dog with chronic pruritus that was refractory to antibiotic, corticosteroid, and antihistamine treatment was found to have lymphoma involving the spleen and associated lymph nodes. Pruritus rapidly resolved on removal of the tumor and recurred on reappearance. The association of generalized pruritus with an occult malignant process may be difficult to assess, but after excluding the more common causes of pruritus, a visceral malignancy should be considered.

Transplantation of canine malignant lymphomas in the nude and SCID mouse.

Canine lymphoid tumours, which share a number of features with human non-Hodgkin's lymphomas, were grafted in nude or SCID mice. Two (DL.24,DL.31) out of eight lymphomas and two (DL.31,DL.35) out of three lymphomas produced a sub-cutaneous (s.c.) tumour in nude and SCID mice respectively. In all animals, the s.c. tumours that developed at the inoculation site were regularly associated with metastasis to the regional lymph nodes, and also to the spleen, liver and bone marrow in SCID mice. The four transplanted tumours, with a pseudo-diploid canine karyotype, were diffuse large cell lymphomas as the initial dog tumours, and could be immunophenotypically characterized by surface immunoglobulins, MHC-class 2 and Thy-1 antigens. Serially transplanted lymphomas in nude and SCID mice may hence be used for further studies of these tumours.