Expression and secretion of immunoglobulin alpha heavy chain with diverse VDJ recombinations by human epithelial cancer cells.
Generally, only B lymphocytes express immunoglobulin. Recently, we found the expression of Ig alpha heavy chain in human epithelial cancer cells unexpectedly. We first detected Ig VDJ-Calpha and Ialpha-Calpha transcripts in multiple cancer cell lines. Further, the configuration of the Ig heavy chain genomic locus was analyzed in human cancer cells. We found that cancer cells have the recombination VDJ region, but bear Ig Salpha region in germline configuration, which is different from Ig expression pattern in B cells. And human epithelial cancers possess the essential effectors including RAG-1 and RAG-2, but not activation induced cytidine deaminase (AID) protein. These provide further proofs for Ig alpha expression. In addition, we found that human cancer cells not only express the protein of Ig alpha chain, but also secrete the protein in secretory IgA (SIgA) pattern. Importantly, diverse CDR3 recombinations were found in human cancer cells of different epithelial origin. Since IgA is the key immunoglobulin which contributes to local immunity of mucous membrane, the aberrant expression of Ig alpha heavy chain might increase our further comprehension to development and immunity of cancers.
Zheng
Hui
H
Cancer Research Institute, Xiangya Medicine School, Central South University, Xiangya Road 110, Changsha, Hunan 410078, China. Gr_huizheng6@yahoo.com
Li
Ming
M
Ren
Wei
W
Zeng
Liang
L
Liu
Hai-dan
HD
Hu
Duosha
D
Deng
Xiyun
X
Tang
Min
M
Shi
Ying
Y
Gong
Jianping
J
Cao
Ya
Y
D001483:Base Sequence; D045744:Cell Line, Tumor; D002999:Clone Cells; D022801:Complementarity Determining Regions / Q000235:genetics; D019295:Computational Biology; D003564:Cytidine Deaminase / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D004847:Epithelial Cells / Q000276:immunology* / Q000473:pathology*; D020224:Expressed Sequence Tags; D015972:Gene Expression Regulation, Neoplastic; D015894:Genome, Human / Q000235:genetics; D006367:HeLa Cells; D018398:Homeodomain Proteins / Q000378:metabolism; D006801:Humans; D007071:Immunoglobulin A, Secretory / Q000235:genetics*; D007137:Immunoglobulin alpha-Chains / Q000235:genetics*; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism; D009369:Neoplasms / Q000276:immunology*; D009687:Nuclear Proteins / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011995:Recombination, Genetic; D050441:VDJ Exons / Q000235:genetics*; D000098830:AICDA (Activation-Induced Cytidine Deaminase)
D022801:Complementarity Determining Regions; D004268:DNA-Binding Proteins; D018398:Homeodomain Proteins; D007071:Immunoglobulin A, Secretory; D007137:Immunoglobulin alpha-Chains; D009363:Neoplasm Proteins; D009687:Nuclear Proteins; C499311:RAG2 protein, human; D012333:RNA, Messenger; C064658:RAG-1 protein; D000098830:AICDA (Activation-Induced Cytidine Deaminase); D003564:Cytidine Deaminase