Therapeutic and Prophylactic Antitumor Activity of an Oral Inhibitor of Fucosylation in Spontaneous Mammary Cancers.

2-fluorofucose (2FF) inhibits protein and cellular fucosylation. Afucosylation of IgG antibodies enhances antibody-dependent cell-mediated cytotoxicity by modulating antibody affinity for FcγRIIIa, which can impact secondary T-cell activation. Immune responses toward most common solid tumors are dominated by a humoral immune response rather than the presence of tumor-infiltrating cytotoxic T cells. IgG antibodies directed against numerous tumor-associated proteins are found in the sera of both patients with breast cancer and transgenic mice bearing mammary cancer. We questioned whether 2FF would have antitumor activity in two genetically distinct transgenic models; TgMMTV-neu (luminal B) and C3(1)-Tag (basal) mammary cancer. 2FF treatment significantly improved overall survival. The TgMMTV-neu doubled survival time compared with controls [P < 0.0001; HR, 7.04; 95% confidence interval (CI), 3.31-15.0], and survival was significantly improved in C3(1)-Tag (P = 0.0013; HR, 3.36; 95% CI, 1.58-7.14). 2FF treated mice, not controls, developed delayed-type hypersensitivity and T-cell responses specific for syngeneic tumor lysates (P < 0.0001). Serum IgG from 2FF-treated mice enhanced tumor lysis more efficiently than control sera (P = 0.004). Administration of 2FF for prophylaxis, at two different doses, significantly delayed tumor onset in both TgMMTV-neu; 20 mmol/L (P = 0.0004; HR, 3.55; 95% CI, 1.60-7.88) and 50 mmol/L (P = 0.0002; HR: 3.89; 95% CI, 1.71-8.86) and C3(1)-Tag; 20 mmol/L (P = 0.0020; HR, 2.51; 95% CI, 1.22-5.18), and 50 mmol/L (P = 0.0012; HR, 3.36; 95% CI, 1.57-7.18). Mammary cancer was prevented in 33% of TgMMTV-neu and 26% of C3(1)-Tag. 2FF has potent antitumor effects in mammary cancer models. The agent shows preclinical efficacy for both cancer treatment and prevention.

Preservation of tumor-host immune interactions with luciferase-tagged imaging in a murine model of ovarian cancer.

BACKGROUND: Ovarian cancer is immunogenic and residual tumor volume after surgery is known to be prognostic. Ovarian cancer often follows a recurring-remitting course and microscopic disease states may present ideal opportunities for immune therapies. We sought to establish the immune profile of a murine model of ovarian cancer that allows in vivo tumor imaging and the quantitation of microscopic disease. RESULTS AND DISCUSSION: Baseline imaging and weight measurements were taken within 1 and 2 weeks after intraperitoneal tumor injection, respectively. Significantly higher photons per second from baseline imaging were first observed 5 weeks after tumor cell injection (p < 0.05) and continued to be significant through 8 weeks after injection (p < 0.01), whereas a significant increase in weight above baseline was not observed until day 56 (p < 0.0001). Expression of luc2 in ID8 cells did not alter the cellular immune microenvironment of the tumor. FOXP3+ T cells were more likely to be detected in the intraepithelial compartment and CD4+ T cells in the stroma as compared to CD3+ T cells, which were found equally in stroma and intraepithelial compartments. CONCLUSIONS: Use of an intraperitoneal tumor expressing a codon-optimized firefly luciferase in an immunocompetent mouse model allows tumor quantitation in vivo and detection of microscopic tumor burdens. Expression of this foreign protein does not significantly effect tumor engraftment or the immune microenvironment of the ID8 cells in vivo and may allow novel immunotherapies to be assessed in a murine model for their translational potential to ovarian cancers in remission or minimal disease after primary cytoreductive surgery or chemotherapy. METHODS: Mouse ovarian surface epithelial cells from C57BL6 mice transformed after serial passage in vitro were transduced with a lentiviral vector expressing a codon optimized firefly luciferase (luc2). Cell lines were selected and luc2 expression functionally confirmed in vitro. Cell lines were intraperitoneally (IP) implanted in albino C57BL/6/BrdCrHsd-Tyrc mice and albino B6(Cg)-Tyrc-2 J/J mice for serial imaging. D-luciferin substrate was injected IP and tumors were serially imaged in vivo using a Xenogen IVIS. Tumor take, weights, and luminescent intensities were measured. Immunohistochemistry was performed on tumors and assessed for immune infiltrates in stromal and intraepithelial compartments.