Cancer testis antigen 83 (CT83) (CT83)

Cancer testis antigen 83 (CT83), also known as Kita-Kyushu lung cancer antigen 1 (KK-LC-1), is a member of the cancer-testis antigen (CTA) family [1, 3]. It is a single-pass type II membrane protein that is normally expressed exclusively in the testis, an immune-privileged site, but is aberrantly upregulated in various solid tumors [2, 12]. High expression levels of CT83 have been observed in non-small cell lung cancer, gastric cancer, triple-negative breast cancer, and hepatocellular carcinoma [6, 10]. Biologically, CT83 promotes malignant phenotypes such as cell proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) through the activation of pathways like Notch1 and PI3K/AKT/mTOR [8, 9, 13]. It also contributes to immune evasion by upregulating PD-L1 expression in the tumor microenvironment [13]. Because of its high tumor specificity and immunogenicity, CT83 is a promising target for precision immunotherapy [5, 16]. Therapeutic approaches currently being explored include TCR-engineered T-cell (TCR-T) therapies, bispecific antibodies, and cancer vaccines [6, 16, 17]. These treatments aim to exploit the restricted expression of CT83 to achieve potent anti-tumor activity with minimal off-target toxicity [16].

Other names

Kita-Kyushu lung cancer antigen 1KK-LC-1CXorf61KKLC1Chromosome X open reading frame 61FLJ20611FLJ22913

Adoptive T-cell receptor (TCR) therapy, T-cell redirection via bispecific antibodies, small molecule inhibition of signaling pathways, and cancer vaccination.