CCCTC-binding factor-like (CTCFL) (CTCFL)

CCCTC-binding factor-like (CTCFL), also known as Brother of the regulator of imprinted sites (BORIS), is a DNA-binding transcription factor and a paralog of the highly conserved architectural protein CTCF (UniProt: Q8NI51). Under physiological conditions, BORIS expression is strictly limited to the testis, specifically within primary spermatocytes, where it facilitates epigenetic reprogramming and the establishment of genomic imprints (NCBI Gene: 140690). However, BORIS is frequently upregulated in a wide array of cancers, including breast, lung, and ovarian malignancies, earning it the classification of a cancer-testis antigen (CTA) (PubMed: 23536885). In the oncogenic context, BORIS competes with CTCF for binding sites, leading to altered gene expression patterns that favor tumor progression, cell survival, and metastasis (PubMed: 30104615). Because it is absent in normal somatic tissues but prevalent in tumors, BORIS serves as an ideal target for precision immunotherapy (PubMed: 29150510). Current therapeutic strategies include the development of DNA vaccines and adoptive T-cell therapies designed to recognize BORIS-derived peptides presented on the surface of cancer cells (PubMed: 25609153). Additionally, research is ongoing to determine if small molecules can disrupt its DNA-binding activity or its interaction with co-factors to inhibit its pro-tumorigenic functions. Its role as a master regulator of the cancer-germline gene expression program makes it a focal point for understanding cancer epigenetics. Monitoring BORIS expression levels also provides valuable prognostic information across various solid tumors. Overall, BORIS represents a unique intersection of developmental biology and oncology with significant therapeutic potential.

Other names

Brother of the regulator of imprinted sitesBORISCTCF-like proteinZinc finger protein CTCFL

Induction of antigen-specific cytotoxic T-lymphocyte (CTL) responses against tumor cells expressing BORIS (PubMed: 25609153); competitive displacement of CTCF from DNA binding sites to reverse oncogenic transcriptional programs (PubMed: 30104615).