title: Therapeutic targeting of tetraspanin8 in epithelial ovarian cancer invasion and metastasis.
abstract: Epithelial ovarian cancer (EOC) invasion and metastasis are complex phenomena that result from the coordinated action of many metastatic regulators and must be overcome to improve clinical outcomes for patients with these cancers. The identification of novel therapeutic targets is critical because of the limited success of current treatment regimens, particularly in advanced-stage ovarian cancers. In this study, we found that tetraspanin 8 (TSPAN8) is overexpressed in about 52% (14/27) of EOC tissues and correlates with poor survival. Using small interfering RNA-mediated TSPAN8 knockdown and a competition assay with purified TSPAN8 large extracellular loop (TSPAN8-LEL) protein, we identified TSPAN8-LEL as a key regulator of EOC cell invasion. Furthermore, monotherapy with TSPAN8-blocking antibody we developed shows that antibody-based modulation of TSPAN8-LEL can significantly reduce the incidence of EOC metastasis without severe toxicity in vivo. Finally, we demonstrated that the TSPAN8-blocking antibody promotes the internalization and concomitant downregulation of cell surface TSPAN8. Collectively, our data suggest TSPAN8 as a potential novel therapeutic target in EOCs and antibody targeting of TSPAN8 as an effective strategy for inhibiting invasion and metastasis of TSPAN8-expressing EOCs.
authors.affiliation: Laboratory of Molecular Cancer Therapeutics, Scripps Korea Antibody Institute,, Chuncheon-si, Korea.
authors.forename: C S
authors.initials: CS
authors.lastname: Park
authors.affiliation: Laboratory of Molecular Cancer Therapeutics, Scripps Korea Antibody Institute,, Chuncheon-si, Korea.
authors.forename: T-K
authors.initials: TK
authors.lastname: Kim
authors.affiliation: New Experimental Therapeutics Branch, Research Institute, National Cancer Center, Goyang-si, Korea.
authors.forename: H G
authors.initials: HG
authors.lastname: Kim
authors.affiliation: Specific Organs Cancer Branch, Research Institute, National Cancer Center, Goyang-si, Korea.
authors.forename: Y-J
authors.initials: YJ
authors.lastname: Kim
authors.affiliation: Laboratory of Molecular Cancer Therapeutics, Scripps Korea Antibody Institute,, Chuncheon-si, Korea.
authors.forename: M H
authors.initials: MH
authors.lastname: Jeoung
authors.affiliation: Laboratory of Molecular Cancer Therapeutics, Scripps Korea Antibody Institute,, Chuncheon-si, Korea.
authors.forename: W R
authors.initials: WR
authors.lastname: Lee
authors.affiliation: Laboratory of Molecular Cancer Therapeutics, Scripps Korea Antibody Institute,, Chuncheon-si, Korea.
authors.forename: N K
authors.initials: NK
authors.lastname: Go
authors.affiliation: New Experimental Therapeutics Branch, Research Institute, National Cancer Center, Goyang-si, Korea.
authors.forename: K
authors.initials: K
authors.lastname: Heo
authors.affiliation: Laboratory of Molecular Cancer Therapeutics, Scripps Korea Antibody Institute,, Chuncheon-si, Korea.
authors.forename: S
authors.initials: S
authors.lastname: Lee
mesh_terms: D000906:Antibodies / Q000494:pharmacology / Q000627:therapeutic use; D000077216:Carcinoma, Ovarian Epithelial; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000494:pharmacology; D009361:Neoplasm Invasiveness; D009362:Neoplasm Metastasis; D009375:Neoplasms, Glandular and Epithelial / Q000188:drug therapy / Q000473:pathology*; D010051:Ovarian Neoplasms / Q000188:drug therapy / Q000473:pathology*; D059470:Tetraspanins / Q000032:analysis / Q000037:antagonists & inhibitors*
chemical_list: D000906:Antibodies; D007074:Immunoglobulin G; C065609:TSPAN8 protein, human; D059470:Tetraspanins