Pattern of gene expression and immune responses to Semenogelin 1 in chronic hematologic malignancies.
Normal testicular-specific proteins are frequently aberrantly expressed by tumor cells. Based on this, we have investigated Semenogelin 1, a major protein of human semen coagulum thought to be highly specific to seminal vesicles, in leukemic cells. Using reverse transcription-polymerase chain reaction, Semenogelin 1 gene was frequently expressed in chronic myeloid leukemia (5 of 8, 62.5%) and chronic lymphocytic leukemia (5 of 12, 41.7%) but rarely in multiple myeloma (2 of 30, 6.7%). The gene was not expressed in bone marrow or peripheral blood from healthy donors. Semenogelin 1 expression is normally confined to the testis, suggesting that it is a novel Cancer-Testis (CT) antigen. Translation of the mRNA to Semenogelin 1 protein was confirmed by Western blot analysis of tumor cell lysates and by immunocytochemistry. The recombinant Semenogelin 1 protein was used with a control Escherichia coli-derived recombinant protein in ELISA and Western blot analysis to show that high titer IgG antibodies against Semenogelin 1 were detected in some patients, suggesting the in vivo immunogenicity of the protein. Immune responses predicted gene expression by the leukemia cells. Semenogelin 1 was also frequently coexpressed with other CT antigens, Sperm protein 17 and SPAN-Xb. These results therefore indicate that Semenogelin 1 is a novel CT antigen capable of inducing B-cell responses in vivo in chronic leukemias.
Division of Hematology and Oncology, Texas Tech University Health Sciences Center, Amarillo, Texas 79106, USA.
Yana
Y
Zhang
Zhiqing
Z
Wang
Haichao
H
Liu
Francis J
FJ
Giles
Seah H
SH
Lim
D014408:Biomarkers, Tumor / Q000032:analysis*; D015152:Blotting, Northern; D015153:Blotting, Western; D004797:Enzyme-Linked Immunosorbent Assay; D015972:Gene Expression Regulation, Neoplastic; D019337:Hematologic Neoplasms / Q000235:genetics* / Q000276:immunology*; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D029607:Seminal Vesicle Secretory Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000276:immunology
D014408:Biomarkers, Tumor; D012333:RNA, Messenger; D029607:Seminal Vesicle Secretory Proteins; C424482:seminal vesicle-specific antigen