HMMC-1: a humanized monoclonal antibody with therapeutic potential against Müllerian duct-related carcinomas.
OBJECTIVE
The purpose of this research was to generate a human monoclonal antibody specific to gynecological cancers and to evaluate such an antibody as therapy for gynecological cancers.


METHODS
Transchromosomal KM mice were immunized with the human uterine endometrial cancer cell line SNG-S. Hybridomas were constructed between spleen cells from KM mice and mouse myeloma cells. Reactivity of the antibody was evaluated by immunohistochemistry of pathological specimens of gynecological cancers. Cytotoxicity of HMMC-1 against SNG-S cells was tested by in vitro cytotoxicity assays. The epitope of HMMC-1 was determined by transfection with a panel of glycosyltransferase cDNAs and by inhibition assays with chemically synthesized oligosaccharides.


RESULTS
HMMC-1 is a human IgM monoclonal antibody that reacts positively with mullerian duct-related carcinomas with positive rates of 54.6% against uterine endometrial adenocarcinoma, 76.9% against uterine cervical adenocarcinoma, and 75.0% against epithelial ovarian cancer. HMMC-1 does not react with normal endometrium at proliferative or secretory phases, normal uterine cervix, or normal and malignant tissue from other organs, whereas it reacts weakly with the epithelium of the gall bladder and the collecting duct of the kidney. HMMC-1 exhibits antigen-dependent and complement-mediated cytotoxicity. Upon cotransfection with cDNAs encoding two glycosyltransferases required for fucosylated extended core 1 O-glycan, mammalian cells express HMMC-1 antigen. Finally, binding of HMMC-1 to SNG-S cells is inhibited by synthetic Fucalpha1-->2Galbeta1-->4GlcNAcbeta1-->3Galbeta1-->3GalNAcalpha1-octyl.


CONCLUSIONS
These results indicate that HMMC-1 specifically recognizes a novel O-glycan structure. The unique specificity and cytotoxicity of HMMC-1 strongly suggest a therapeutic potential of this antibody.
Nozawa
Shiro
S
Department of Obstetrics and Gynecology and Division of Diagnostic Pathology, School of Medicine, Keio University, Tokyo, Japan. shiron@sc.itc.keio.ac.jp
Aoki
Daisuke
D
Tsukazaki
Katsumi
K
Susumu
Nobuyuki
N
Sakayori
Motoko
M
Suzuki
Nao
N
Suzuki
Atsushi
A
Wakita
Rie
R
Mukai
Makio
M
Egami
Yuko
Y
Kojima-Aikawa
Kyoko
K
Ishida
Isao
I
Belot
Frederic
F
Hindsgaul
Ole
O
Fukuda
Minoru
M
Fukuda
Michiko N
MN
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D061067:Antibodies, Monoclonal, Humanized; D002277:Carcinoma / Q000276:immunology* / Q000473:pathology; D018076:DNA, Complementary / Q000032:analysis; D005260:Female; D005833:Genital Neoplasms, Female / Q000276:immunology* / Q000473:pathology; D016695:Glycosyltransferases / Q000235:genetics; D006801:Humans; D006825:Hybridomas; D007075:Immunoglobulin M / Q000276:immunology*; D007150:Immunohistochemistry; D051379:Mice; D009095:Mullerian Ducts / Q000473:pathology*; D009101:Multiple Myeloma / Q000473:pathology; D013154:Spleen / Q000166:cytology; D014407:Tumor Cells, Cultured
D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D018076:DNA, Complementary; C498094:HMMC-1 monoclonal antibody; D007075:Immunoglobulin M; D016695:Glycosyltransferases