Serological identification of Tektin5 as a cancer/testis antigen and its immunogenicity

Abstract

BackgroundIdentification of new cancer antigens is necessary for the efficient diagnosis and immunotherapy. A variety of tumor antigens have been identified by several methodologies. Among those antigens, cancer/testis (CT) antigens have became promising targets.MethodsThe serological identification of antigens by the recombinant expression cloning (SEREX) methodology has been successfully used for the identification of cancer/testis (CT) antigens. We performed the SEREX analysis of colon cancer.ResultsWe isolated a total of 60 positive cDNA clones comprising 38 different genes. They included 2 genes with testis-specific expression profiles in the UniGene database, such as TEKT5 and a CT-like gene, A kinase anchoring protein 3 (AKAP3). Quantitative real-time RT-PCR analysis showed that the expression of TEKT5 was restricted to the testis in normal adult tissues. In malignant tissues, TEKT5 was aberrantly expressed in a variety of cancers, including colon cancer. A serological survey of 101 cancer patients with different cancers by ELISA revealed antibodies to TEKT5 in 13 patients, including colon cancer. None of the 16 healthy donor serum samples were reactive in the same test.ConclusionWe identified candidate new CT antigen of colon cancer, TEKT5. The findings indicate that TEKT5 is immunogenic in humans, and suggest its potential use as diagnostic as well as an immunotherapeutic reagent for cancer patients.

Cancer/testis antigens: A prospective reagent as diagnostic and immunotherapeutic targets for squamous cell carcinoma of the head and neck

“…None of the healthy donor serum was reactive. Three serum samples from the same panel of sera were also reactive against TEKT5 [32]. Taken together, these findings suggest that the serologically-defined CT antigens, CCDC62-2, GKAP1, and TEKT5, may provide a molecular basis for diagnostic and immunotherapeutic targets in HNSCC patients.…”

“…Hanafusa et al performed SEREX analysis on colon cancer, and identified the novel CT antigen, Tektin 5 (TEKT5) [32]. TETKs are composed of a family of filament-forming proteins in the male germ cell-lineage in centrioles and basal bodies and within ciliary and flagellar doublet microtubules [64].…”

“…No reactivity was observed in sera from healthy donors. TETK5 appears to have high immunogenic potential in terms of antibody frequency [32].…”

“…SSX2, SYCP-1, and NY-ESO-1 were isolated using cDNA libraries from cancer or normal testis tissues [26][27][28]. Additional CT antigens, such as XAGE-1, CCDC62-2, GKAP1, and TEKT5, were identified in our SEREX analysis [29][30][31][32].…”

Serological Identification of URGCP as a Potential Biomarker for Glioma

“…To date, more than 600 tumor-associated antigens have been identified using by SE-REX [9,10]. Most of the SEREX-based studies aimed at the identification of novel tumor antigens that elicit an antibody response in tumor tissue or cell lines [11][12][13][14][15][16]. Until now, there was no antigen identified by SEREX based on tumor stem cell, which is notorious for GBM recurrence and malignance [5,17,18].…”