Prospective evaluation of flow cytometric characteristics, histopathologic diagnosis and clinical outcome in dogs with naïve B-cell lymphoma treated with a 19-week CHOP protocol.

Canine B-cell lymphoma is a clinically heterogenous disease; however, it is generally treated as a single disease entity. The purpose of this clinical trial was to prospectively evaluate naïve canine B-cell lymphoma patients using histopathology, flow cytometry (FC) and a standardized chemotherapy protocol to better define subsets of this disease that may respond differently to treatment. Sixty-four dogs with naïve multicentric B-cell lymphoma were treated with a standardized 19-week CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) chemotherapy protocol. Most of the dogs (84.3%) were diagnosed with diffuse large B-cell lymphoma (DLBCL), followed by nodal marginal zone (7.8%), small B-cell (4.7%), Burkitt-like (1.6%) and follicular lymphoma (1.6%). FC confirmed the diagnosis of B-cell lymphoma in all cases. There were no clear phenotyping differences between the subtypes of B-cell lymphoma detectable by our FC panel. The histologic subtypes in this study exhibited a range of forward scatter values on flow cytometry, but all of the DLBCL cases were higher than a value of 469, while the only cases with a lower forward scatter value were follicular lymphoma and diffuse small B-cell lymphoma. Dogs with DLBCL had a significantly better objective response rate to the CHOP protocol (96.3%) than the non-DLBCL subtypes (70%, P = .024). The median progression-free survival time for patients with DLBCL (233 days) was significantly longer than that of all other histopathologic subgroups combined (163 days, P = .0005).

Glycolysis inhibition by 2-deoxy-D-glucose reverts the metastatic phenotype in vitro and in vivo.

Metastasis is the primary cause of death from many tumors, and novel anti-metastatic therapies are necessary. Recently, we showed that metastatic tumors down-regulate key oxidative phosphorylation (OXPHOS) genes in favor of glycolysis, a further enhancement of the Warburg effect. Therefore, we sought to determine if restriction of glycolysis using 2-deoxy-D-glucose (2DG) would lead to increased utilization of OXPHOS and inhibition of the metastatic phenotype. Noncytotoxic concentrations of 2DG dose-dependently inhibited in vitro migration and invasion in the highly metastatic DLM8-luc-M1 osteosarcoma (OS) cell line, as well as other metastatic human, canine, and murine cancer cells of different histotypes. This was associated with cytoskeletal rearrangement and inhibition of cathepsin L expression. A dose-dependent shift toward OXPHOS was confirmed by demonstrating increased oxygen utilization and decreased lactate production in 2DG treated cells. Finally, 2DG treatment significantly delayed metastasis and prolonged survival in an orthotopic postsurgical OS model. In conclusion, this work suggests that forcing cells away from glycolysis may inhibit key components of the metastatic phenotype, providing a novel avenue for metastasis prevention.