Ropporin-1A (ROPN1A) (ROPN1)

Ropporin-1A (ROPN1) is a specialized structural and signaling protein primarily localized to the fibrous sheath of the sperm flagellum, where it plays a critical role in sperm motility and capacitation through interactions with A-kinase anchoring proteins (AKAPs) and rhophilin. As a member of the cancer-testis antigen (CTA) family, its expression in healthy individuals is highly restricted to the testis, an immune-privileged site, making it an ideal target for precision oncology. ROPN1 is frequently overexpressed in aggressive malignancies, including triple-negative breast cancer, multiple myeloma, and melanoma, where it may contribute to tumor progression via the activation of RhoA signaling pathways. Current therapeutic development focuses on adoptive immunotherapy, specifically TCR-engineered T-cells designed to recognize intracellular ROPN1 peptides presented on MHC molecules. These experimental therapies have demonstrated potent preclinical activity and high specificity, offering a promising avenue for treating cancers that lack traditional surface receptors.

Other names

Ropporin-1Cancer/testis antigen 91CT91Rhophilin-associated protein 1AOuter dense fiber of sperm tails 6ODF6Sperm-specific protein

Adoptive T-cell therapy involving the engineering of T-cells to express T-cell receptors (TCRs) that specifically recognize ROPN1-derived peptides presented on human leukocyte antigen (HLA) molecules, such as HLA-A2.