The discovery of genes that are overexpressed in ovarian cancers provides valuable insight into ovarian cancer biology and will lead to the development of more effective treatment strategies for ...combating this disease. To identify genes exhibiting ovarian- and ovarian cancer-specific expression, we generated four subtracted cDNA libraries from primary and metastatic ovarian adenocarcinoma tissues. 3,400 cDNA clones from these libraries were analyzed by microarray for tissue distribution and tumor specificity using 32 pairs of fluorophore-labeled cDNA samples from a variety of normal tissues and ovarian tumor tissues. cDNA clones showing elevated expression in ovarian tumors were identified by DNA sequencing with comparison to public databases, and the most promising candidates were further analyzed by quantitative real-time polymerase chain reaction and Northern blot. This systematic approach led to the identification of a number of genes including vascular smooth muscle growth-promoting factor (VSGP/F-spondin), a secreted protein previously identified and cloned from bovine and human ovary. VSGP/F-spondin protein was observed in ovarian carcinomas but not in normal ovarian epithelium by immunohistochemistry with a VSGP/F-spondin antibody. The expression profile of VSGP/F-spondin identifies this molecule as a potential diagnostic marker or target for developing therapeutic strategies to treat ovarian carcinoma.
Abstract 3722
Despite advances in treatments for B-cell leukemias and lymphomas, many patients ultimately relapse and succumb to disease following multiple courses of therapy. Bispecific antibody ...fragments that can simultaneously engage T cells and tumor cells have been shown, in the literature, to destroy tumor cells by effectively redirecting the cytotoxic function of T cells. T-cell engaging bispecific molecules linking anti-CD19 and anti-CD3 binding domains in the context of novel SCORPION™ (multi-specific protein therapeutic) proteins were evaluated both in vitro and in vivo for function and stability.
Redirected T-cell cytotoxicity (RTCC) was measured by combining CD19 positive or negative cell lines with SCORPION proteins in the presence of human T cells. In a similar assay context, CFSE-labeled T cells were monitored for activation and proliferation. Functional RTCC assays were also used to analyze serum stability of SCORPION molecules in vitro and to complete an in vivo pharmacokinetic analysis. In vivo efficacy was assessed by monitoring the rate of tumor outgrowth of Ramos xenografts co-implanted with human peripheral blood mononuclear cells (PBMC) in NOD/SCID mice after treatment with SCORPION molecules.
SCORPION molecules potently mediate target-specific T-cell cytotoxicity toward tumor cell lines presenting cell surface CD19, with EC50 values for cytotoxicity at low pM concentrations. These molecules also demonstrate induction of T-cell activation and proliferation in the presence of target-bearing tumor cells but not in the absence of target expression. SCORPION molecules retain stable function following incubation at 37°C in mouse serum for up to a week in vitro, and pharmacokinetic analysis of SCORPION protein function in BALB/c mouse serum following intravenous administration resulted in half-life estimates of 69–84 hours. In efficacy studies conducted in NOD/SCID mice, SCORPION proteins significantly inhibited the outgrowth of Ramos tumor xenografts in the presence of human effector cells.
SCORPION molecules targeting CD19 and CD3 effectively harness the cytotoxic activity of T cells to kill CD19 positive tumor cells both in vitro and in vivo and show potential for further investigation as possible therapeutic agents for B-cell malignancies.
Chenault:Emergent BioSolutions: Employment. Gottschalk:Emergent BioSolutions: Employment. Hernandez-Hoyos:Emergent BioSolutions: Employment. Wiens:Emergent BioSolutions: Employment. Gordon:Emergent BioSolutions: Employment. Klee:Emergent BioSolutions: Employment, Equity Ownership. Bienvenue:Emergent BioSolutions: Employment. Dasovich:Emergent BioSolutions: Employment. Kumer:Emergent BioSolutions: Employment. Aguilar:Emergent BioSolutions: Employment. Bannink:Emergent BioSolutions: Employment, Equity Ownership. McMahan:Emergent BioSolutions: Employment, Equity Ownership. Natarajan:Emergent BioSolutions: Employment, Equity Ownership. Algate:Emergent BioSolutions: Employment, Equity Ownership. Blankenship:Emergent BioSolutions: Employment, Equity Ownership, Patents & Royalties.
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