401. Tissue factor expression in ovarian cancer: implications for immunotherapy with hI-con1, a factor VII-IgGF(c) chimeric protein targeting tissue factor.
- Author
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Cocco E, Varughese J, Buza N, Bellone S, Lin KY, Bellone M, Todeschini P, Silasi DA, Azodi M, Schwartz PE, Rutherford TJ, Carrara L, Tassi R, Pecorelli S, Lockwood CJ, and Santin AD
- Subjects
- Cell Line, Tumor, Factor VII immunology, Factor VII metabolism, Factor VII therapeutic use, Female, Humans, Immunoconjugates immunology, Immunoconjugates metabolism, Immunoglobulin Fc Fragments immunology, Immunoglobulin Fc Fragments metabolism, Immunoglobulin Fc Fragments therapeutic use, Ovarian Neoplasms immunology, Ovarian Neoplasms metabolism, Thromboplastin genetics, Thromboplastin immunology, Thromboplastin metabolism, Gene Expression Regulation, Neoplastic, Immunoconjugates therapeutic use, Immunotherapy methods, Ovarian Neoplasms drug therapy, Thromboplastin therapeutic use
- Abstract
We evaluated the expression of tissue factor (TF) in ovarian cancer (EOC) and the potential of hI-con1, an antibody-like molecule targeting TF, as a novel form of therapy against chemotherapy-resistant ovarian disease. We studied the expression of TF in 88 EOC by immunohistochemistry (IHC) and real-time-PCR (qRT-PCR) and the levels of membrane-bound-complement-regulatory-proteins CD46, CD55 and CD59 in primary EOC cell lines by flow-cytometry. Sensitivity to hI-con1-dependent-cell-mediated-cytotoxicity (IDCC), complement-dependent-cell-cytotoxicity and inhibition of IDCC by γ-immunoglobulin were evaluated in 5-h (51)chromium-release-assays. Cytoplasmic and/or membrane TF expression was observed in 24 out of 25 (96%) of the EOC samples tested by IHC, but not in normal ovarian-tissue. EOC with clear cell histology significantly overexpress TF when compared to serous, endometrioid, or undifferentiated tumors by qRT-PCR. With a single exception, all primary EOC that overexpressed TF demonstrated high levels of CD46, CD55 and CD59 and regardless of their histology or resistance to chemotherapy, were highly sensitive to IDCC. The effect of complement and physiologic doses of γ-immunoglobulin on IDCC in ovarian cancer cell lines overexpressing TF was tumor specific and related to the overexpression of CD59 on tumor cells. Small-interfering-RNA-mediated knockdown of CD59 expression in ovarian tumors significantly increased hI-con1-mediated cytotoxic activity in vitro. Finally, low doses of interleukin-2 further increased the cytotoxic effect induced by hI-con1 (P < 0.01). hI-con1 molecule induces strong cytotoxicity against primary chemotherapy-resistant ovarian cancer cell lines overexpressing TF and may represent a novel therapeutic agent for the treatment of ovarian tumors refractory to standard treatment modalities.
- Published
- 2011
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