CT7 (MAGE-C1) antigen expression in normal and neoplastic tissues.
CT7 (MAGE-C1) is a member of the cancer testis (CT) antigen family. The present study describes the generation of CT7-33, a monoclonal antibody (MAb) to CT7, and the preliminary protein expression analysis of CT7 in normal tissues and in a limited number of neoplastic lesions. CT7-33 was effective in frozen as well as formalin-fixed, paraffin-embedded tissues, and immunohistochemistry/reverse transcriptase polymerase chain reaction (RT-PCR) co-typing demonstrated antibody specificity. CT7-33 immunoreactivity in normal adult tissues is restricted to testicular germ cells. In neoplastic lesions, CT7-33 immunostaining is confined to tumor cells, and the frequency of CT7 protein expression mostly parallels previous mRNA analyses. Whereas colorectal and renal cell carcinomas, as well as sarcomas, exhibit poor or no CT7-33 staining, carcinomas of the mammary gland and ovary, nonsmall cell lung carcinoma and metastatic melanomas exhibit a high incidence of CT7 protein expression. However, as seen in previous analyses of other CT antigens, the expression pattern is mostly heterogeneous, and tumors with more than 50% of tumor staining are only infrequently encountered. In summary, our study presents a new serologic reagent for the analysis of CT7 on a protein level and confirms what is known with regard to the expression pattern of other CT antigens in tumors: frequent heterogeneity of antigen expression.
Ludwig Institute for Cancer Research, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA. jungblua@mskcc.org
Achim A
AA
Jungbluth
Yao-Tseng
YT
Chen
Klaus J
KJ
Busam
Keren
K
Coplan
Denise
D
Kolb
Kristin
K
Iversen
Barbara
B
Williamson
Frank K H
FK
Van Landeghem
Elisabeth
E
Stockert
Lloyd J
LJ
Old
D000818:Animals; D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm / Q000276:immunology / Q000378:metabolism*; D017931:DNA Primers / Q000737:chemistry; D015870:Gene Expression; D006801:Humans; D007114:Immunization; D007124:Immunoenzyme Techniques; D051379:Mice; D008807:Mice, Inbred BALB C; D009363:Neoplasm Proteins / Q000276:immunology / Q000378:metabolism*; D009369:Neoplasms / Q000378:metabolism* / Q000473:pathology; D016612:Paraffin Embedding; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D011994:Recombinant Proteins / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction
D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm; D017931:DNA Primers; C110905:MAGEC1 protein, human; D009363:Neoplasm Proteins; D012333:RNA, Messenger; D011994:Recombinant Proteins