RESUMO
BACKGROUND: small B-cell neoplasms can show plasmacytic differentiation and may potentially progress to aggressive lymphoma (DLBCL). Epstein-Barr virus (EBV) infection may cause the transformation of malignant cells in vitro. DESIGN AND METHOD: we established VR09 cell line with plasmacytic differentiation, obtained from a case of atypical, non-CLL B-cell chronic lymphoproliferative disease with plasmacytic features. We used flow cytometry, immunohistochemistry, polymerase chain reaction, cytogenetic analysis and florescence in situ hybridization in the attempt at thoroughly characterizing the cell line. We showed VR09 tumorigenic potential in vivo, leading to the development of activated DLBCL with plasmacytic features. RESULTS: VR09 cells displayed plasmacytic appearance and grew as spherical tumors when inoculated subcutaneously into immunodeficient Rag2(-/-) γ-chain(-/-) mice. VR09 cell line and tumors displayed the phenotype of activated stage of B cell maturation, with secretory differentiation (CD19+ CD20+ CD79a+ CD79b+/- CD138+ cyclin D1- Ki67 80% IgM+ IgD+ MUM1+ MNDA+ CD10- CD22+ CD23+ CD43+ K+, λ- Bcl2+ Bcl6-) and they presented episomal EBV genome, chromosome 12 trisomy, lack of c-MYC rearrangement and Myd88 gene mutation, presence of somatic hypermutation in the VH region, and wild-type p53. CONCLUSION: This new EBV-positive cell line may be useful to further characterize in vivo activated DLBCL with plasmacytic features.
Assuntos
Linfoma Difuso de Grandes Células B/genética , Linfoma Difuso de Grandes Células B/metabolismo , Idoso , Animais , Proteínas Adaptadoras de Sinalização CARD/genética , Antígenos CD79/genética , Ciclo Celular , Linhagem Celular Tumoral , Modelos Animais de Doenças , Guanilato Ciclase/genética , Herpesvirus Humano 4/genética , Humanos , Cadeias Pesadas de Imunoglobulinas/genética , Região Variável de Imunoglobulina/genética , Imunofenotipagem , Hibridização in Situ Fluorescente , Cariótipo , Linfoma Difuso de Grandes Células B/patologia , Linfoma Difuso de Grandes Células B/virologia , Masculino , Camundongos , Camundongos Knockout , Mutação , Fator 88 de Diferenciação Mieloide/genética , Transplante Heterólogo , Proteína Supressora de Tumor p53/genéticaRESUMO
Pancreatic adenocarcinoma is a common malignancy that remains refractory to all available therapies, including the gold standard drug gemcitabine (GEM). We investigated the effect of the combination of GEM and each of the ionophore compounds pyrrolidine dithiocarbamate (PDTC) and disulfiram [DSF; 1-(diethylthiocarbamoyldisulfanyl)-N,N-diethylmethanethioamide] on p53(-/-) pancreatic adenocarcinoma cell growth. PDTC or DSF synergistically inhibited cell proliferation when used in combination with GEM by inducing apoptotic cell death. This effect was associated with an increased mitochondrial O(2)(â¢-) production and was further enhanced by zinc ions. Basal levels of mitochondrial O(2)(â¢-) or manganese superoxide dismutase (MnSOD) strictly correlated with the IC(50) for GEM or the percentage of synergism. Thus, the most relevant values of the antiproliferative synergism were obtained in GEM-resistant pancreatic adenocarcinoma cell lines. Interestingly, the GEM-sensitive T3M4 cells transfected with MnSOD expression vector showed mitochondrial O(2)(â¢-) and IC(50) for GEM similar to those of resistant cell lines. In vivo experiments performed on nude mice xenotransplanted with the GEM-resistant PaCa44 cell line showed that only the combined treatment with GEM and DSF/Zn completely inhibited the growth of the tumoral masses. These results and the consideration that DSF is already used in clinics strongly support the GEM and DSF/Zn combination as a new approach to overcoming pancreatic cancer resistance to standard chemotherapy.
